HomeMy WebLinkAbout182402-Glace-Bay-Wastewater-Pre-Design-Summary-Report-Final
182402.00 / 187116.00 ● Draft Report ● March 2020
Environmental Risk Assessments
& Preliminary Design of Seven Future
Wastewater Treatment
Systems in CBRM
Glace Bay Wastewater Interception & Treatment System
Prepared by:
Prepared for:
Final
Glace Bay WW Interception &
Treatment System Pre‐Design
Summary Report‐Draft
March 27, 2020 Darrin McLean James Sheppard Darrin McLean
Issue or Revision Date Issued By: Reviewed By: Prepared By:
This document was prepared for the party indicated
herein. The material and information in the
document reflects HE’s opinion and best judgment
based on the information available at the time of
preparation. Any use of this document or reliance
on its content by third parties is the responsibility of
the third party. HE accepts no responsibility for any
damages suffered as a result of third party use of
this document.
182402.00 GLACE BAY SUMMARY REPORT.DOCX/mk
ED: 10/07/2020 10:21:00/PD: 10/07/2020 10:22:00
164 Charlotte St.
PO Box 567
Sydney, NS
B1P 6H4
March 27, 2020
Matt Viva, P.Eng.
Manager Wastewater Operations
Cape Breton Regional Municipality (CBRM)
320 Esplanade,
Sydney, NS B1P 7B9
Dear Mr. Viva:
RE: Glace Bay Wastewater Interception & Treatment System – Pre‐Design Summary
Report
Enclosed, please find, for your review, a copy of the draft Pre‐Design Summary Report for the
Glace Bay Wastewater Interception & Treatment System.
This report presents a description of proposed wastewater interception and treatment
infrastructure upgrades for the Glace Bay wastewater system, as well as an estimate of the
capital, operating costs, and replacement costs for the proposed infrastructure. In addition,
estimated costs of upgrades and assessments related to the existing wastewater collection
system are provided. A summary of geotechnical work completed for the wastewater
treatment facility site is also provided, along with an archaeological resources impact
assessment review for all sites of proposed wastewater infrastructure, and a Phase I
Environmental Site Assessment. Finally, an Implementation Timeline is provided, which
outlines a tentative schedule for implementation of the various proposed wastewater system
upgrades.
If you have any questions or require clarification on the content presented in the attached
report, please do not hesitate to contact us.
Yours very truly,
Harbour Engineering Joint Venture
Prepared by: Reviewed by:
Darrin McLean, MBA, FEC, P.Eng. James Sheppard, P.Eng.
Senior Municipal Engineer Civil Infrastructure Engineer
Direct: 902‐539‐1330 (Ext. 3138) Direct: 902‐562‐9880
E‐Mail: dmclean@cbcl.ca E‐Mail: jsheppard@dillon.ca
Project No: 182402.00 (CBCL)
187116.00 (Dillon)
final
HEJV Glace Bay Wastewater System Pre‐Design Summary Report i
Contents
CHAPTER 1 Introduction & Background ......................................................................................... 1
1.1 Introduction ........................................................................................................................ 1
1.2 Background ......................................................................................................................... 1
1.3 Description of Existing Wastewater Collection System ...................................................... 1
1.4 Service Area Population ...................................................................................................... 2
CHAPTER 2 Wastewater Interceptor System .................................................................................. 3
2.1 Description of Proposed Wastewater Interceptor Infrastructure ...................................... 3
2.2 Interception Infrastructure Land/Easement Acquisition Requirements ............................ 4
2.2.1 Lift Station Sites ...................................................................................................... 4
2.2.2 Linear Infrastructure ............................................................................................... 4
CHAPTER 3 Existing Wastewater Collection System Upgrades / Assessments ................................ 6
3.1 Sewage Pump Station Upgrades ......................................................................................... 6
3.2 Asset Condition Assessment Program ................................................................................ 6
3.3 Sewer Separation Measures ............................................................................................... 6
3.4 CSO Station Outfall Upgrades ............................................................................................. 6
CHAPTER 4 Wastewater Treatment System ................................................................................... 7
4.1 Recommended Wastewater Treatment Facility ................................................................. 7
4.2 Wastewater Treatment Facility Land Acquisition Requirements ....................................... 8
4.3 Wastewater Treatment Facility Site Geotechnical Investigations ...................................... 8
4.4 Wastewater Treatment Facility Site Environmental Site Assessment ................................ 9
CHAPTER 5 Wastewater System Archaeological Resources Impact Assessment ........................... 12
5.1 Archaeological Resources Impact Assessment ................................................................. 12
CHAPTER 6 Wastewater Infrastructure Costs ............................................................................... 14
6.1 Wastewater Interception & Treatment Capital Costs ...................................................... 14
6.2 Wastewater Interception & Treatment Annual Operating Costs ..................................... 15
6.3 Annual Capital Replacement Fund Contribution Costs .................................................... 15
6.4 Existing Wastewater Collection System Upgrades / Assessment Costs ........................... 17
CHAPTER 7 Project Implementation Timeline .............................................................................. 18
7.1 Implementation Schedule ................................................................................................. 18
Appendices
A Glace Bay Collection System Pre‐Design Brief
B Glace Bay Wastewater Treatment System Pre‐Design Brief
C Glace Bay Environmental Risk Assessment Report
HEJV Glace Bay Wastewater System Pre‐Design Summary Report ii
D Glace Bay Wastewater Treatment Facility Site Desktop Geotechnical Review
E Glace Bay Wastewater System Archaeological Resources Impact Assessment
F Glace Bay Wastewater System Phase I Environmental Site Assessment
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 1
CHAPTER 1 INTRODUCTION & BACKGROUND
1.1 Introduction
Harbour Engineering Joint Venture (HEJV) was retained by the Cape Breton Regional Municipality
(CBRM) to provide engineering services associated with the preliminary design of wastewater
interception and treatment infrastructure for the community of Glace Bay, Nova Scotia as part of the
greater Environmental Risk Assessment and Preliminary Design of 7 Future Wastewater Treatment
Systems in CBRM project. This report presents a description of the proposed infrastructure upgrades
for the Glace Bay Wastewater system, as well as an estimate of the capital, operating and replacement
costs for the proposed infrastructure. In addition, estimated costs of upgrades and assessments
related to the existing wastewater collection system are provided. A summary of geotechnical work
completed for the wastewater treatment facility site is also provided, along with an archaeological
resources impact assessment review for all sites of proposed wastewater infrastructure, and a Phase
I Environmental Site Assessment. Finally, an Implementation Timeline is provided, which outlines a
tentative schedule for implementation of the various proposed wastewater system upgrades.
1.2 Background
The wastewater collection system in the community of Glace Bay, as in many communities throughout
CBRM, currently discharges untreated wastewater to the Atlantic Ocean. The evolution of the existing
wastewater collection and disposal systems in CBRM included the creation of regions of a community
which were serviced by a common wastewater collection system tied to a local marine outfall. Such
design approaches have traditionally been the most cost‐effective manner of providing centralized
wastewater collection, and the marine environment has long been the preferred receiving water given
the available dilution. Due to a changing regulatory environment, CBRM is working toward intercepting
and treating the wastewater in these communities prior to discharge.
The Glace Bay system has been classified as high risk under the federal Wastewater System Effluent
Regulations (WSER) under the Fisheries Act, requiring implementation of treatment systems by the year
2021.
1.3 Description of Existing Wastewater Collection System
The Glace Bay wastewater collection system includes a significant portion of the footprint of the
former Town of Glace Bay and the community of Reserve Mines. The remainder of the Glace Bay
area flows to the Dominion system. The system consists of approximately 118km of gravity sewer
and 3.1km of force main. It also includes six pump stations and nine known overflows.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 2
The majority of the wastewater is already directed to the main outfall at Glace Bay Harbour, with
the remainder being discharged through eight additional outfalls along the coast to the north of the
main outfall. The outfalls are located at or near the following locations:
GB#1 – Khalsa Drive
GB#2 – Shea’s Lane
GB#3 – Centre Avenue;
GB#4 – East Avenue (2 outfalls);
GB#5 – Second Street;
GB#6 and GB#7 – Upper North Street;
GB#8 – Glace Bay Harbour (main outfall);
An additional outfall is located at the northern end of Second Street. This outfall receives discharge
from one home. This home would be best served in the future by a low pressure sewer system that
would convey discharge towards the new interceptor sewer.
Approximately 85% of the flow in Glace Bay is already diverted to GB#8, making this general area an
ideal location for the future WWTP site.
1.4 Service Area Population
For Glace Bay, the service area population was estimated to be 14,536 people in 7,258 residential
units. The population of the CBRM has been declining and this trend is expected to continue. Recent
population projection studies predict a 17.8% decrease in population in Cape Breton County between
2016 and 2036. For this reason, no allocation has been made for any future population growth.
For the purpose of preliminary design, wastewater infrastructure has been sized based on the current
population and measured flow data. While this may seem overly conservative, due to significant
amounts of inflow and infiltration (I&I) observed in sewer systems in the CBRM, a given population
decrease will not necessarily result in a proportional decrease in wastewater flow. Therefore, basing
the design on current population is considered the most reasonable approach.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 3
CHAPTER 2 WASTEWATER INTERCEPTOR SYSTEM
2.1 Description of Proposed Wastewater Interceptor Infrastructure
The proposed wastewater interceptor system for the Glace Bay Wastewater System includes the
following major elements:
LS‐GB 1 located near the GB#1 outfall, on PID 15441355. This pump station conveys flow
eastward through a common forcemain that extends to Centre Avenue. The forcemain from
LS‐GB1 to LS‐GB2 is 150mm in diameter. From LS‐GB2 eastward, the forcemain diameter
increases to 200mm in diameter.
LS‐GB2 is located behind Shea’s Lane and Eleventh Street on PID 15440969. This pump
station intercepts flow from outfalls GB#2 and GB#3. The pump station conveys discharge
via a 200 mm diameter forcemain to the common forcemain discussed above.
A gravity sewer that begins as a 200mm and terminates as a 450mm diameter gravity main
conveys sewage along Centre Avenue and Eighth Street.
Flow from the GB#4A outfall is intercepted by a 200mm diameter gravity main and is
directed to a proposed CSO chamber located near the Eighth Street and East Avenue
intersection.
Flow from the GB#4B outfall is intercepted by a 450mm diameter gravity main and is
directed to the same CSO chamber located near the Eighth Street/East Avenue intersection.
A 450mm diameter gravity sewer conveys the intercepted flow cross country from the CSO
toward First Street.
A 200mm diameter sewer will be required near the 2nd Street/Hub Avenue intersection to
intercept flow from GB#5 to the interceptor system located near First Street.
From the connection with the 2nd Street sewer, a gravity sewer extends from First Street
across PID 15437718. The sewer runs along West Avenue, Tennyson Street and Vivian Street
to Upper North Street, eventually to the LS‐GB3 site.
A small section of 450mm diameter gravity sewer connects GB#6 to GB#7. The flow from
the gravity sewer is directed to a CSO chamber (CSO‐5).
Flow from CSO‐5 is merged with the gravity interceptor sewer on Upper North Street and is
directed to LS‐GB3.
LS‐GB3 handles all of the flow from each of the seven outfalls north of the Glace Bay WWTP
site.
LS‐GB3 conveys sewage to the proposed WWTP via a 250mm diameter forcemain.
LS‐GB4 (located within the GB WWTP footprint) intercepts sewer from the GB#8 outfall. The
WWTP site will be complete with a CSO overflow structure that will convey overflow to the
proposed outfall.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 4
Outside of the interceptor sewer, one home at the end of 4th Street will require a low‐
pressure sewer system as it currently discharges directly to the Atlantic Ocean.
A detailed description of the proposed wastewater interceptor system, including preliminary layout
drawings is provided in Appendix A.
2.2 Interception Infrastructure Land/Easement Acquisition Requirements
2.2.1 Lift Station Sites
Construction of sewage pumping stations will require property acquisitions as shown in the table
below.
Table 1 ‐ Lift Station Sites Land Acquisition Requirements
PID# Property
Owner Assessed Value Description Size Required
Purchase
Entire Lot
(Y/N)
154413551 PWGSC $10,100 LS‐GB1/CSO
Site 15mX70m N
15440969 PWGSC $17,500 LS‐GB2/CSO
Site 60mX80m(irreg.) N
15739113
Road Parcel
Owner
Undetermined
No information LS‐GB3/CSO
Site 15mx30m Y
1Additional easement required for linear infrastructure, see Table 2 for further details on size requirements.
2.2.2 Linear Infrastructure
Installation of linear infrastructure such as pressure and gravity sewer piping and manholes will
require property acquisitions or easements as shown in the table below.
Table 2 ‐ Linear Infrastructure Land Acquisition Requirements
PID# Property
Owner Assessed Value Description Length Required Purchase Entire
Lot (Y/N)
154413551 PWGSC $10,100 Forcemain 84m N
15441090 PWGSC $25,300 Forcemain 67m N
15440936 Youth for
Christ Canada $289,000
Forcemain/
Gravity
Sewer
25m N
15526668 PWGSC $16,300 Gravity
Sewer 7m N
15437791 PWGSC $44,500 Gravity
Sewer 24m N
15437742 PWGSC $8,300 Gravity
Sewer 29m N
15531064 PWGSC $400 Gravity
Sewer 147m N
15531023 PWGSC $66,300 Gravity
Sewer 18m N
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 5
15821127 Owner
Unknown No Information Forcemain 22m Y
15821119 Charles H
Rigby No Information Forcemain 65m Y
1 Additional easement required for pump station infrastructure, see Table 1 for further details on size requirements.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 6
CHAPTER 3 EXISTING WASTEWATER COLLECTION SYSTEM
UPGRADES / ASSESSMENTS
3.1 Sewage Pump Station Upgrades
HEJV has reviewed the existing Glace Bay Collection System for potential upgrades to the existing
sewage pumping stations. There are currently six pump stations in the community of Glace Bay. The
age of the existing stations vary. All of the stations have been upgraded previously. Since 2015,
upgrades have been performed to 4 of the 6 existing stations. The remaining two stations were
upgraded in 2011. The Glace Bay WWTP has been classified as a high priority system and has an
implementation deadline of 2021. Plans should be made to upgrade stations that have not been
recently renewed, including the Reserve Street and Railroad Street pump stations (upgraded in
2011). Due to their age, the condition of each station should be verified at the time of detailed
design to determine if an upgrade of the existing station is required.
3.2 Asset Condition Assessment Program
To get a better sense of the condition of the existing Glace Bay sewage collection system, HEJV
recommends completing a sewage collection system asset condition assessment program in the
community. The program would carry out an investigation involving two components:
1. Visual inspection and assessment of all manholes in the collection system
2. Video inspection of 20% of all sewers in the system
The program should be completed with the issuance of a Collection System Asset Condition
Assessment Report that would summarize the condition of the various assets inspected and include
opinions of probable costs for required upgrades.
3.3 Sewer Separation Measures
CBRM should consider completing further sewer separation investigation efforts in Glace Bay. The
program would review catch basins that are currently connected or possibly connected to existing
sanitary sewers. The program should also include the costing of the installation of new storm
sewers to disconnect catch basins from the existing sanitary sewer.
3.4 CSO Station Outfall Upgrades
Upgrades should be provided at existing outfalls that will be utilized as overflows from the proposed
CSO Stations. A connection should be made with the existing outfall that would allow the pipe to be
extended into the marine environment versus conveying overflow through the existing shoreline
embankments (above shoreline elevation).
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 7
CHAPTER 4 WASTEWATER TREATMENT SYSTEM
4.1 Recommended Wastewater Treatment Facility
The recommended wastewater treatment facility for Glace Bay is the Sequencing Batch Reactor (SBR)
process, which is an aerobic suspended‐growth biological treatment process. The SBR process is a
batch process whereby secondary treatment, including nitrification, is achieved in one reactor. It
involves a “fill and draw” type reactor where aeration and clarification occur in the same reactor.
Settling is initiated after the aeration cycle and supernatant is withdrawn through a decanter
mechanism. The WWTP would provide the following general features:
1. Preliminary treatment involving raw wastewater screening and grit removal;
2. Secondary treatment involving three continuous‐flow SBR tanks;
3. Disinfection of the treated wastewater with the use of ultraviolet (UV) disinfection unit;
4. Sludge management by means of aerated sludge holding tanks, sludge dewatering centrifuge
and associated bin room;
5. Odour control equipment;
6. Staff work spaces, including office space, laboratory space, control room, locker room, lunch
room, and washrooms;
7. Site access and parking, along with site fencing; and,
8. New outfall.
The proposed site of the Glace Bay WWTP is located near Lower North Street. The design loads for
the proposed WWTP are as shown in the table below.
Table 3 ‐ WWTP Design Loading Summary
Parameter Average Day Peak Day
Design Population 14,536
Flow (m3/day) 13,815 41,445
CBOD Load (kg/day) 1381.5 2763
TSS Load (kg/day) 1519.7 3039
TKN Load (kg/day) 269 538
A detailed description of the proposed wastewater treatment system, including preliminary layout
drawings is provided in Appendix B.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 8
The associated Environmental Risk Assessment Report, which outlines effluent criteria for the
proposed wastewater treatment facility for Glace Bay is provided in Appendix C.
4.2 Wastewater Treatment Facility Land Acquisition Requirements
Construction of the proposed wastewater treatment facility will require property acquisitions as
shown in the table below.
Table 4 ‐ WWTP Land Acquisition Requirements
PID# Property
Owner
Assessed
Value Size Required
Purchase
Entire Lot
(Y/N)
15408867 Hopkins H Ltd. $130,300 4698 m2 N
15524473 PWGSC $5,900 1294 m2 N
15859796 David and Ann
MacKenzie $11,700 1006 m2 Y
15833007 Marilyn Gillard No info 1022 m2 Y
15395221 Marilyn Gillard $9,700 2690 m2 Y
4.3 Wastewater Treatment Facility Site Geotechnical Investigations
A desktop geotechnical assessment was initially completed which included a review of the subsurface
soil conditions at the proposed site for the Glace Bay Wastewater Treatment Facility. In general, the
review involved a field visit to the site to observe the general conditions and a desktop review of
available documents with the intent of commenting on the following issues:
site topography;
geology (surficial ground cover, probable overburden soil and bedrock type);
geotechnical problems and parameters;
previous land use (review of aerial photographs);
underground/surface mining activities; and
proposed supplemental ground investigation methods (test pits and/or boreholes)
The following geotechnical issues were noted at the site:
1. There is evidence of the erodibility of subsurface soils and bedrock exposure along the Atlantic
coastline.
2. The area under the proposed construction site was undermined due to historical coal mining
activities and there is a potential for undocumented bootleg pits/mines in the area.
3. There is the potential for a layer of limestone to be present underlying the surficial ground
and alternating layers of bedrock below the site. Limestone is water soluble and has the
potential to develop karsts voids (sinkholes).
4. The presence of uncontrolled fills on the site due to historical activity.
The review recommended an intrusive borehole program on the site to further define the subsurface
conditions.
Next, an intrusive geotechnical program was completed which included advancement of six boreholes
covering to potential sites. Voids were encountered on the site situated north of Lower North Street
which was classified as being moderate to high risk for subsidence. No voids were encountered on the
site situated south of Lower North Street which was classified as being low to moderate risk. The
report included the following recommendations:
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 9
1. The presence of mine workings below the subject property gives rise to the potential for
future subsidence, which could impact structures resulting in significant settlements over
time.
2. The presence of uncontrolled fill within the footprint of the new facilities should be
excavated and replaced with compacted engineered fill. Since the history of development is
unknown, fill may be present to greater depths than was encountered at the borehole
locations. Careful inspection of the base of the excavations and proof rolling with
appropriately sized equipment will be important to confirm the suitability of the bearing
material. The native glacial till materials beneath the fill should provide a suitable bearing
stratum.
3. Groundwater and surficial water control (north side of Lower North Street) should be
planned for during construction to avoid softening of the fill and native glacial till soils.
Similarly, protection of exposed sub‐grade and compacted fill surfaces against freezing and
thawing should be planned for.
Following the intrusive program, a rock mechanics evaluation, including additional intrusive
investigation, was conducted to determine whether the rock layers between the proposed WWTP
and existing voids could effectively bridge the weight of the WWTP structures, such that the level of
risk to develop the site would be reduced. This work included advancement of four boreholes. The
rock mechanics analysis resulted in a lower characterisation of the level of subsidence risk for each
of the prospective sites as compared to previous assessments. For Site #1 the report considered the
site to carry a very low risk, while Site #2 was denoted as low risk.
A copy of the Glace Bay WWTP site geotechnical summary report is provided in Appendix D.
4.4 Wastewater Treatment Facility Site Environmental Site Assessment
Harbour Engineering Joint Venture conducted a Phase I Environmental Site Assessment (ESA) on
eight properties denoted by Parcel Identification Designation Numbers (PID Nos.): 15393606,
15524481, 15654882, 15821119, 15395221, 15833007, 15864085 and 15408867 located in Glace
Bay, Nova Scotia. This Phase I Environmental Site Assessment (ESA) was conducted in accordance
with the guidelines and principles established by the Canadian Standard Association (CSA) Standard
Z768‐01 for Phase I ESAs CSA, 2001 (updated April 2003 and reaffirmed in 2016) and included a
records review, site visit, interviews with knowledgeable persons and reporting of the findings.
The following is a summary of the findings and potential sources of environmental contamination
identified during the Phase I ESA conducted at the site and the associated recommendations:
Buildings associated with fish plant operations (Hopkins H. Ltd.) are located on the south
portion of the site (i.e., PID No. 15408867). Available fire insurance plans show a petroleum
storage tank historically located on this portion of the site. The fish plant building interiors
and the immediately surrounding grounds of these buildings were not accessible at the time
of the site visit. Current petroleum storage on this portion of the site is unknown. Further,
the exact use of these fish plant buildings is also unknown. As these on‐site buildings are
located down gradient of the proposed WWTP and lift station locations, and as the
anticipated groundwater flow direction is expected to be easterly toward Glace Bay
Harbour, these buildings are unlikely to represent an environmental concern relative to the
proposed locations of the WWTP and lift station.
Findings of a Nova Scotia Environment (NSE) environmental registry search identified a
contaminated sites complaint file for 57, 59, 61 and 63 Oceancrest Drive (located
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 10
immediately west of the site). These records, which were subject to the Freedom of
Information and Protection of Privacy (FOIPOP) Act, were subsequently requested. Findings
of the FOIPOP Act request indicate that the records were not available and that the file was
destroyed as per the NSE retention schedule. Therefore, the contents and nature of the
contaminated sites complaint are unknown. Although located immediately adjacent to the
site (i.e., immediately west of PID No. 15393606), these properties are approximately 200
meters (m) and 325 m northwest of the proposed WWTP and lift station locations,
respectively. Further, as the groundwater flow direction is anticipated to be easterly, the
potential for impacts to the actual proposed WWTP and lift station locations within the site
from 57, 59, 61 and 63 Oceancrest Drive are considered to be low.
Based on the age of the fish plant buildings located on the southeast portion of the site (i.e.,
PID No. 15408867), asbestos containing materials (ACM) may be present on‐site. Testing
would be required to confirm/refute the presence of ACM. It is noted that an asbestos
survey was not conducted as part of this ESA. Further, building interiors were not accessible
at the time of the site visit. Demolition practices associated with former on‐site buildings,
which may have contained ACM, are unknown.
A pad‐mounted transformer was observed on the west portion of the site (i.e., PID No.
15654882) adjacent to the Bay Plex Building. It is unknown if this transformer contains
polychlorinated biphenyls (PCBs). The transformer was observed to be in good condition
and situated on a concrete pad. No evidence of leakage or staining was observed.
An aboveground storage tank (AST) was observed on the west portion of the site (i.e., on
PID No. 15654882) in association with the Bay Plex Building. The AST was observed to be in
fair condition with some surface rusting apparent. The tank was located within a fenced
enclosure. The tank tag was not visible. Although not observed, petroleum storage tanks are
suspected on the southeast portion of the site (i.e., on PID No. 15408867) in association
with the on‐site fish plant buildings. Historical heating sources and practices associated with
former on‐site buildings are unknown. Further assessment would be required to assess if
former or current petroleum storage on‐site has resulted in an environmental concern for
the site.
Based on the age of the fish plant buildings located on the southeast portion of the site (i.e.,
PID No. 15408867), lead‐containing paint and/or solder may be present. Testing would be
required to confirm/refute the presence of lead. Precautionary measures should be taken
for individuals considered sensitive to lead if paint is peeling or in poor condition. Paint with
elevated lead concentrations, which is in poor condition should be removed using a
qualified lead abatement contractor. Precaution should be exercised during renovations
that disturb lead‐containing surfaces to minimize exposures. Demolition practices
associated with former on‐site buildings, which may have had lead‐containing paint and/or
solder, are unknown.
Mercury containing equipment may be present within the on‐site buildings, the interiors of
which were not accessible at the time of the site visit. Further, based on the age of the fish
plant buildings, located on the southeast portion of the site (i.e., PID No. 15408867),
mercury containing paints may be present. Disposal of mercury containing paints or
equipment, if found on‐site, should be in accordance with Provincial regulations. Demolition
practices associated with former on‐site buildings, which may have had mercury‐containing
paint and/or equipment, are unknown.
The on‐site building interiors were inaccessible at the time of the site visit; however, based
on the nature of on‐site building use (i.e., fish plant and rink), ozone depleting substances
(ODS) equipment is expected to be present on‐site. Maintenance to units containing ODS
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 11
should be conducted using licensed contractors. Refrigerant gases are required to be
drained and recovered by a licensed contractor prior to disposal.
The on‐site building interiors were inaccessible at the time of the site visit. Due to the age of
the on‐site fish plant buildings, located on the southeast portion of the site (i.e., PID No.
15408867), there is potential that urea formaldehyde foam insulation (UFFI) may be
present. If found on‐site, UFFI should be removed as per provincial regulations.
Potential sources of magnetic fields observed during the site visit include a communication
tower located west and south of the site.
Miscellaneous debris, including household appliances, metal, plastic, wood, and rubber,
were observed across the site. Debris should be removed to a licenced disposal facility.
Portions of the site (i.e., PID Nos. 15393606, 15833007, 15395221 and 15821119) were
observed to be in‐filled. Concrete, asphalt, rubber, wood, plastic and metal debris was
observed within the in‐filled areas of the site. Seven fill piles were observed on the east
portion of the site (i.e., on PID No. 15408867). A gravel fill pile was observed on the
southwest portion of the site (i.e., on PID No. 15654882) in the gravel parking area of the
Bay Plex. This fill pile may be associated with snow removal activities. Sampling would be
require to confirm if impacts are present on‐site from the observed fill materials.
As noted above, the interior of the on‐site Bay Plex building was not accessible at the time
of the site visit. Based on available public information, the Bay Plex building reportedly
requires mould abatement and remediation prior to planned renovation and upgrades to
the facility.
Findings of the Environment and Climate Change Canada search request were pending at
the time the report was issued.
A copy of the Glace Bay WWTP site environmental site assessment is provided in Appendix F.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 12
CHAPTER 5 WASTEWATER SYSTEM ARCHAEOLOGICAL
RESOURCES IMPACT ASSESSMENT
5.1 Archaeological Resources Impact Assessment
In October 2018, Davis MacIntyre & Associates Limited conducted a phase I archaeological resource
impact assessment at sites of proposed new wastewater infrastructure for the Glace Bay Wastewater
System. The assessment included a historic background study and reconnaissance in order to
determine the potential for archaeological resources in the impact area and to provide
recommendations for further mitigation, if necessary.
The historic background study indicates that the coastal region of Glace Bay was occupied and
frequented in the mid‐18th century by the English and French, who took advantage of the lucrative
mines in the area. It is known that Mi’kmaw peoples were settled at nearby Mira and likely at Lingan
as well, when European settlers first arrived. These coves were suitable for hunting and fishing and
were well sheltered from the north Atlantic winds. The headlands between these areas, however, are
open, barren and exposed and boggy in many areas, making it an unsuitable place to live out of
wigwams. It is known, however, that they traded and interacted frequently with European settlers
along this coast so their presence does not go unnoticed, though it is unlikely that their presence
would have left an archaeological signature in the study area itself.
Much of the study area has been previously impacted by infrastructure development and housing.
The most significant potential archaeological resource near the study area is that of Fort William,
though it is believed to lie outside the study area at the end of Eleventh Street and, therefore, is not
likely to be impacted if remains of the fort do, indeed, still exist.
Therefore, no further active archaeological mitigation is recommended for the study area. However,
in the unlikely event that any archaeological resources are encountered at any time during ground
disturbance, it is required that all activity cease and the Coordinator of Special Places (902‐424‐6475)
be contacted immediately regarding a suitable method of mitigation. Furthermore, in the event that
development plans change so that areas not evaluated as part of this assessment will be impacted, it
is recommended that those areas be assessed by a qualified archaeologist.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 13
Finally, it is recommended that, if available, a qualified palaeontologist or geologist be contracted to
examine any bedrock exposed during the project excavation, and to determine the need for any
further paleontological monitoring.
A copy of the detailed Glace Bay Wastewater System Archaeological Resources Impact Assessment
Report is provided in Appendix E. It should be noted that this report was registered with the Nova
Scotia Department of Communities, Culture and Heritage in April 2019.
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 14
CHAPTER 6 WASTEWATER INFRASTRUCTURE COSTS
6.1 Wastewater Interception & Treatment Capital Costs
An opinion of probable capital cost for the recommended wastewater interception and treatment
system for Glace Bay is presented in the table below.
Table 5 – Glace Bay Wastewater Interception & Treatment System Capital Costs
Project Component Capital Cost (Excluding
Taxes)
Wastewater Interception System $6,964,275
Wastewater Interception System Land Acquisition $207,600
Subtotal 1: $7,171,875
Construction Contingency (25%): $1,741,000
Engineering (10%): $696,000
Total Wastewater Interception: $9,608,875
Wastewater Treatment Facility $28,581,000
Wastewater Treatment Facility Land Acquisition $200,000
Subtotal 2: $28,781,000
Construction Contingency (25%): $7,145,250
Engineering (12%): $3,430,000
Total Wastewater Treatment: $39,356,250
Total Interception & Treatment System: $48,965,125
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 15
6.2 Wastewater Interception & Treatment Annual Operating Costs
An opinion of probable annual operating costs for the recommended wastewater interception and
treatment system for Glace Bay is presented in the table below.
Table 6 – Glace Bay Wastewater Interception & Treatment System Operating Costs
Project Component Annual Operating Cost
(Excluding Taxes)
Wastewater Interception System
General Linear Maintenance Cost $1,000
General Lift Station Maintenance Cost $15,500
Employee O&M Cost $14,500
Electrical Operational Cost $52,000
Backup Generator O&M Cost $9,500
Total Wastewater Interception Annual Operating Costs: $92,500
Wastewater Treatment Facility
Equipment Maintenance Cost $47,000
Chemicals $33,000
Staffing $500,000
Power $270,000
Sludge Disposal $220,000
Total Wastewater Treatment Annual Operating Costs: $1,070,000
Total Interception & Treatment System Annual Operating Costs: $1,162,500
6.3 Annual Capital Replacement Fund Contribution Costs
The CBRM wishes to create a Capital Replacement Fund to which annual contributions would be made
to prepare for replacement of the wastewater assets at the end of their useful life. The calculation of
annual contributions to this fund involves consideration of such factors as the type of asset, the asset
value, the expected useful life of the asset, and the corresponding annual depreciation rate for the
asset. In consideration of these factors, the table below provides an estimate of the annual
contributions to a capital replacement fund for the proposed new wastewater interception and
treatment system infrastructure. This calculation also adds the same contingency factors used in the
calculation of the Opinion of Probable Capital Cost, to provide an allowance for changes during the
design and construction period. The actual Annual Capital Replacement Fund Contributions will be
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 16
calculated based on the final constructed asset value, the type of asset, the expected useful life of the
asset, and the corresponding annual depreciation rate for the asset type. Please note that costs
shown below do not account for annual inflation and do not include applicable taxes.
Table 7 – Glace Bay Wastewater Interception & Treatment System Capital Replacement Fund
Costs
Description of Asset Asset Value
Asset Useful
Life
Expectancy
(Years)
Annual
Depreciation
Rate (%)
Annual Capital
Replacement
Fund Contribution
Wastewater Interception System
Linear Assets (Piping,
Manholes and Other) $4,858,475 75 1.3% $63,160
Pump Station Structures
(Concrete Chambers, etc.) $1,158,190 50 2.0% $23,164
Pump Station Equipment
(Mechanical / Electrical) $947,610 20 5.0% $47,381
Subtotal $6,964,275 ‐ ‐ $133,704
Construction Contingency (Subtotal x 25%): $33,426
Engineering (Subtotal x 10%): $13,370
Wastewater Interception System Annual Capital Replacement Fund
Contribution Costs: $180,500
Wastewater Treatment System
Treatment Linear Assets
(Yard Piping, Manholes and
Other)
$3,080,366 75 1.3% $41,000
Treatment Structures
(Concrete Chambers, etc.) $11,461,000 50 2.0% $229,000
Treatment Equipment
(Mechanical / Electrical,
etc.)
$14,039,634 20 5.0% $702,000
Subtotal $28,581,000 ‐ ‐ $972,000
Construction Contingency (Subtotal x 25%): $243,000
Engineering (Subtotal x 12%): $117,000
Wastewater Treatment System Annual Capital Replacement Fund Contribution
Costs: $1,332,000
Total Wastewater Interception & Treatment Annual Capital Replacement
Fund Contribution Costs: $1,512,500
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 17
6.4 Existing Wastewater Collection System Upgrades / Assessment Costs
The estimated costs of upgrades and assessments related to the existing wastewater collection
system as described in Chapter 3 are shown in the table below.
Table 8 ‐ Existing Wastewater Collection System Upgrades / Assessment Costs
Item Cost
Sewage Pump Station Upgrades (for 2 stations)
Pump Station Infrastructure (controls, pumps, etc.) $652,000
Backup Power Generation (only required for 4 stations) $233,000
Engineering (12%) $106,000
Contingency (25%) $222,000
Total $1,213,000
Collection System Asset Condition Assessment Program
Condition Assessment of Manholes based on 1482 MHs $275,000
Condition Assessment of Sewer Mains based on 25.2 kms of
infrastructure $260,000
Total $535,000
Sewer Separation Measures
Separation based on 126 kms of sewer @ $45,000/km $5,670,000
Engineering (10%) $567,000
Contingency (25%) $1,418,000
Total $7,655,000
CSO Station Outfall Upgrades (for 5 existing outfalls)
Extension incl. drop manhole ($248,000 per connection) $1,240,000
Engineering (12%) $149,000
Contingency (25%) $310,000
Total $1,699,000
Total Estimated Existing Collection System Upgrade and
Assessment Costs $11,102,000
HEJV Glace Bay Wastewater System Pre‐Design Summary Report 18
CHAPTER 7 PROJECT IMPLEMENTATION TIMELINE
7.1 Implementation Schedule
Figure 1 provides a tentative schedule for implementation of wastewater system upgrades for Glace
Bay, including proposed wastewater interception and treatment infrastructure as well as upgrades to
and assessment of the existing collection system.
For the High‐risk systems such as Glace Bay, it is expected that implementation of proposed upgrades
will commence in 2020. However, the project implementation schedule has been tentatively outlined
on a generalized basis (Year 1, Year 2, etc.) rather than with specified deadlines.
The schedule has been structured such that asset condition assessments and investigations to locate
sources of extraneous water entering the system would be carried out in Year 1. Design/construction
of recommended upgrades will also start in Year 1. Detailed design of proposed interception and
treatment infrastructure, including additional flow metering, will be conducted in Years 2 and 3, with
construction occurring in Years 3 through 5. Project closeout would occur in Years 5 and 6. This
results in a tentative implementation schedule that covers a six (6) year timeline.
It should be noted that, although the process of pursuing the acquisition of properties and easements
required to construct the proposed wastewater upgrades as outlined in previous sections is not shown
on the Project Implementation Schedule, it is recommended that the CBRM pursue these acquisitions
prior to the commencement of detailed design.
No. Project Component Period: Jan - Mar Apr - Jun Jul - Sept Oct - Dec Jan - Mar Apr - Jun Jul - Sept Oct - Dec Jan - Mar Apr - Jun Jul - Sept Oct - Dec Jan - Mar Apr - Jun Jul - Sept Oct - Dec
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:$40,000
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
$9,330,475
$1,372,000
$37,984,250
$260,000
$164,400
$5,119,100
$75,000
$278,400
Figure 1 - Project Implementation Schedule Glace Bay Wastewater System
Year:1 2 3 4
1 Carry out asset condition assessment of all manholes in the existing collection system
2 Carry out video inspection and assessment of selected sanitary sewers in the existing collection system
$275,000
$5,119,100
3 Carry out Sewer Separation Investigation Study to locate sources of extraneous water entering the
collection system $75,000
4 Carry out asset condition assessment of all sewage pumping stations in the existing collection system
5 Carry out detailed design for recommended upgrades to the existing collection system based on previous
assessments $164,400
6 Carry out tendering, construction and commissioning for recommended upgrades to the existing
collection system
7 Carry out flow metering and wastewater testing in the existing collection system to confirm wastewater
flows and organic loading
8 Carry out detailed design for proposed wastewater interception infrastructure
9 Carry out tendering, construction, commissioning and initial systems operations for proposed wastewater
interception infrastructure
10 Carry out detailed design for proposed wastewater treatment infrastructure
11 Carry out tendering, construction, commissioning and initial systems operations for proposed wastewater
treatment infrastructure
HEJV Glace Bay Wastewater System Pre‐Design Summary Report Appendices
APPENDIX A
Glace Bay Collection System Pre‐Design Brief
1.1.1.1
187116 ●Draft Brief ●April 2020
Environmental Risk Assessments & Preliminary
Design of Seven Future Wastewater Treatment
Systems in CBRM
Glace Bay Collection System Pre-Design Brief
Prepared by:Prepared for:
Final March 2020
Re-Issued Glace Bay
Collection System Draft Pre-
Design Brief
June 30, 2020 James Sheppard,
P.Eng.
Darrin McLean, MBA,
FEC., P.Eng.
Darrin McLean, MBA,
FEC., P.Eng.
Re-Issued Glace Bay
Collection System Draft Pre-
Design Brief
May 9, 2019 James Sheppard,
P.Eng.
Darrin McLean, MBA,
FEC., P.Eng.
Darrin McLean, MBA,
FEC., P.Eng.
Glace Bay Collection System
Draft Pre-Design Brief
March 21, 2019 James Sheppard,
P.Eng.
Darrin McLean, MBA,
FEC., P.Eng.
Darrin McLean, MBA,
FEC., P.Eng.
Glace Bay Collection System
Draft Pre- Design Brief
September 7, 2018 James Sheppard,
P.Eng.
Bob King, P.Eng.Darrin McLean, MBA,
FEC., P.Eng.
Issue or Revision Date Prepared By:Reviewed By:Issued By:
This document was prepared for the
party indicated herein. The material
and information in the document
reflects the opinion and best judgment
of Harbour Engineering Joint Venture
(HEJV) based on the information
available at the time of preparation.
Any use of this document or reliance
on its content by third parties is the
responsibility of the third party. HEJV
accepts no responsibility for any
damages suffered as a result of third
party use of this document.
March 27, 2020
275 Charlotte Street
Sydney, Nova Scotia
Canada
B1P 1C6
Tel: 902-562-9880
Fax: 902-562-9890
_________________
GLACE BAY COLLECTION SYSTEM PRE DESIGN BRIEF REV2.DOCX/sj
ED: 29/06/2020 16:16:00/PD: 29/06/2020 16:18:00
June 30, 2020
Matthew D. Viva, P.Eng.
Manager of Wastewater Operations
Cape Breton Regional Municipality
320 Esplanade, Sydney, NS B1P 7B9
Dear Mr. Viva:
RE: Environmental Risk Assessments & Preliminary Design of Seven Future
Wastewater Treatment Systems in CBRM – Glace Bay Collection System
Pre-Design Brief
Harbour Engineering Joint Venture (HEJV) is pleased to submit the following
Collection System Pre-Design Brief for your review and comment. This Brief
summarizes the interceptors, local sewers and pumping stations that will form
the proposed wastewater collection for the Town of Glace Bay. The interceptor
system will convey sewer to the future Wastewater Treatment Plant that will be
located near the breakwater at the mouth of Glace Bay Harbour. The Brief also
outlines the design requirements and standards for the required infrastructure
components.
We look forward to your comments on this document.
Yours very truly,
Harbour Engineering Joint Venture
Prepared by: Reviewed by:
James Sheppard, P.Eng. Darrin McLean, MBA, FEC, P.Eng.
Civil Infrastructure Engineer Senior Civil Engineer
Direct: 902-562-9880 Direct: 902-539-1330
E-Mail:jsheppard@dillon.ca E-Mail:dmclean@cbcl.ca
Project No: 187116 (Dillon) and 182402.00 (CBCL)
March 27, 2020
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief i
Contents
CHAPTER 1 Introduction & Background ........................................................................................... 1
1.1 Introduction ................................................................................................................... 1
1.2 System Background ........................................................................................................ 1
1.2.1 General ............................................................................................................... 1
1.2.2 GB#1 ................................................................................................................... 2
1.2.3 GB#2 ................................................................................................................... 2
1.2.4 GB#3 ................................................................................................................... 2
1.2.5 GB#4 ................................................................................................................... 3
1.2.6 GB#5 ................................................................................................................... 3
1.2.7 GB#6 ................................................................................................................... 3
1.2.8 GB#7 ................................................................................................................... 3
1.2.9 GB#8 ................................................................................................................... 3
CHAPTER 2 Design Parameters & Standards .................................................................................... 5
2.1 General Overview ........................................................................................................... 5
2.2 Design Standards ............................................................................................................ 5
CHAPTER 3 Wastewater Interceptor Pre- Design ............................................................................. 7
3.1 General Overview ........................................................................................................... 7
3.2 Design Flows .................................................................................................................. 7
3.2.1 Theoretical Flow ................................................................................................. 7
3.2.2 Initial Observed Flows ......................................................................................... 8
3.2.3 Additional Observed Flows ............................................................................... 10
3.2.4 Flow Conclusions & Recommendations ............................................................. 10
3.3 Interceptor System ....................................................................................................... 12
3.3.1 Option Analysis ................................................................................................. 13
3.3.2 Interceptor System Breakdown ......................................................................... 14
3.4 Combined Sewer Overflows.......................................................................................... 14
3.4.1 CSO-1................................................................................................................ 15
3.4.2 CSO-2................................................................................................................ 15
3.4.3 CSO-3................................................................................................................ 15
3.4.4 CSO-4................................................................................................................ 15
3.4.5 CSO-5................................................................................................................ 15
3.4.6 CSO-6................................................................................................................ 16
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief ii
3.5 Pumping Stations ......................................................................................................... 16
3.5.1 Pumping Design Capacity .................................................................................. 16
3.5.2 Safety Features ................................................................................................. 17
3.5.3 Wetwell ............................................................................................................ 17
3.5.4 Station Piping.................................................................................................... 18
3.5.5 Equipment Access ............................................................................................. 18
3.5.6 Emergency Power ............................................................................................. 18
3.5.7 Controls ............................................................................................................ 19
3.5.8 Security ............................................................................................................ 19
CHAPTER 4 Existing Collection System Upgrades ........................................................................... 20
4.1 Sewage Pump Station Upgrades ................................................................................... 20
4.2 Asset Condition Assessment Program ........................................................................... 20
4.3 Sewer Separation Measures ......................................................................................... 20
4.4 CSO Station Outfall Upgrades ....................................................................................... 20
CHAPTER 5 Forcemain Selection and Design .................................................................................. 21
5.1 Pipe Material ................................................................................................................ 21
CHAPTER 6 Land and Easement Requirements .............................................................................. 22
6.1 Pump Station Sites ....................................................................................................... 22
6.2 WWTP Site ................................................................................................................... 23
6.3 Linear Infrastructure ..................................................................................................... 23
CHAPTER 7 Site Specific Constraints ............................................................................................... 24
7.1 Construction Constraints .............................................................................................. 24
7.2 Environmental Constraints ........................................................................................... 24
7.3 Access Requirements.................................................................................................... 25
7.4 Power Supply Requirements ......................................................................................... 25
CHAPTER 8 Opinion of Probable Costs ........................................................................................... 26
8.1 Opinion of Probable Costs – New Wastewater Collection Infrastructure ....................... 26
8.2 Opinion of Operational Costs ........................................................................................ 26
8.3 Opinion of Existing Collection System Upgrades and Assessment Costs ........................ 27
8.4 Opinion of Annual Capital Replacement Fund Contributions ......................................... 28
CHAPTER 9 References ................................................................................................................... 30
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief iii
Tables
Table 2-1 Sewer Design Criteria ............................................................................................... 5
Table 2-2 Pumping Station Design Criteria ............................................................................... 6
Table 3-1 Theoretical Flow Summary ....................................................................................... 8
Table 3-2 Flow Monitoring Location Summary ......................................................................... 9
Table 3-3 Average Dry Weather and Design Flows Results ....................................................... 9
Table 3-4 Flow Monitoring Location Summary ....................................................................... 10
Table 3-5 Additional Average Dry Weather and Design Flows Results..................................... 10
Table 3-6 Average Dry Weather Summary for Proposed Pump Stations ................................ 11
Table 3-7 Recommended Interception Design Flow Rates at Pump Stations ........................... 11
Table 3-8 Observed Flows during Rainfall Events.................................................................... 11
Table 3-9 Inferred Flows during Rainfall Events ...................................................................... 12
Table 3-10 Pump Station Summary .......................................................................................... 17
Table 3-11 Wetwell Sizing Summary ........................................................................................ 18
Table 5-1 Comparison of Pipe Materials ................................................................................. 21
Table 6-1 Pump Station Land Acquisition Details .................................................................... 22
Table 6-2 WWTP Land Acquisition Details .............................................................................. 23
Table 6-3 Linear Infrastructure Land Acquisition Details ......................................................... 23
Table 7-1 Power Supply Details .............................................................................................. 25
Table 8-1 Annual Operations and Maintenance Costs ............................................................ 26
Table 8-2 Estimated Existing Collection System Upgrade and Assessment Costs..................... 28
Table 8-3 Estimated Annual Capital Replacement Fund Contributions.................................... 29
Appendices
Appendix A –Drawings
Appendix B – Flow Master Reports
Appendix C – Opinion of Probable Design & Construction Costs
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 1
CHAPTER 1 INTRODUCTION &BACKGROUND
1.1 Introduction
Harbour Engineering Joint Venture (HEJV) has been engaged by the Cape Breton Regional
Municipality (CBRM) to carry out Environmental Risk Assessments (ERAs) and Preliminary Design of
seven future wastewater treatment Systems in the CBRM. The future wastewater collection and
treatment systems will serve the communities of Glace Bay, Port Morien, North Sydney & Sydney
Mines, New Waterford, New Victoria, Louisbourg and Donkin, which currently have no wastewater
treatment facilities.
The preliminary design of the wastewater interceptor systems are being completed as an addition to
the existing wastewater systems in each community. In general, the proposed interceptor sewers
will convey wastewater from the existing outfalls to the proposed Wastewater Treatment Plant
(WWTP) in each location. The complexity of each system is directly related to the number of
outfalls, geographic size and topography of each community. In general, the scope of work on the
interceptor system generally includes the following:
®Determination of design wastewater flows;
®Making recommendations on the best sites for proposed wastewater treatment facilities;
®Development of the most appropriate and cost-effective configurations for wastewater
interception;
®Estimation of capital and operations costs for recommended wastewater components;
This document relates to the interceptors, local sewers, combined sewer overflows and pumping
stations that will form the wastewater collection system for the proposed WWTP in the community
of Glace Bay. This brief outlines the design requirements and standards for the required
infrastructure components. Information regarding the preliminary design of the proposed
wastewater treatment facility for Glace Bay will be provided in a separate Design Brief.
1.2 System Background
1.2.1 General
There are 10 wastewater sewersheds in the community of Glace Bay. Two of these sewersheds have
been previously re-directed to the Dominion/Bridgeport WWTP. The remaining sewersheds still
actively discharge raw sewage to the Atlantic Ocean at 8 outfall locations. These outfalls are located
at or near:
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 2
®GB#1 - Khalsa Drive;
®GB#2 - Shea’s Lane;
®GB#3 - Centre Avenue;
®GB#4 - East Avenue (2 outfalls);
®GB#5 - Second Street;
®GB#6 – Upper Water Street;
®GB#7 – Upper Water Street; and,
®GB#8 - Glace Bay Harbour.
An additional outfall is located at the northern end of Second Street. This outfall receives discharge
from one home. This home would be best served in the future by a low pressure sewer system that
would convey discharge towards the new interceptor sewer.
Approximately 85% of the flow in Glace Bay is already diverted to GB#8, making this general area an
ideal location for the future WWTP site.
The Glace Bay wastewater system features six pump stations and nine known overflows.
1.2.2 GB#1
The GB#1 sewershed is made up of a gravity network that services a section of Wallace Road, One B
Road, a section of Connaught Avenue and Denver Street. The outfall for the sewershed is located
between One B Road and Wallace Road, within a natural ravine. The outfall is 375mm in diameter,
but reduces to a 300mm diameter prior to the end of the outfall. The outfall is located in a steep
bank, above the shoreline. The outfall is complete with a bend at the end to direct flow down the
bank. The combination of the smaller diameter pipe and bend do cause surcharging issues upstream
of the outfall. There are no known overflows in the GB#1 sewershed.
1.2.3 GB#2
The GB#2 sewershed is serviced by a 300mm diameter outfall located 120m beyond the end of
Shea’s Lane. The outfall is located within a steep bank, above the shoreline. The sewershed area
includes a portion of Connaught Avenue, Churchill Street, 9th Street, 10th Street, 11th Street and
Reservoir Avenue. While the majority of the sewershed is serviced by a gravity sewer, there is one
pump station located on Railway Street. The station conveys sewage from the eastern end of
Railway Street, 280m to the west, to a high point on the street. The station has an emergency
overflow that is directed toward the pond to the south east of Railway Street.
1.2.4 GB#3
A small area including the northern end of 10th and 11th Street make up the sewershed for GB#3.
The sewershed is serviced by a gravity network that outfalls at the western end of Centre Avenue.
The outfall is 250mm in diameter and is located within the existing bank, above the shoreline. There
are no known overflows in the GB#3 sewershed.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 3
1.2.5 GB#4
GB#4 is located at the northern end of East Avenue. The sewershed is made up of a portion of the
Hub and New Aberdeen, specifically bounded by 1st and 7th Street (north to south) and the
abandoned railway to the west. The area is serviced by a gravity sewer that directs flow to the
intersection of Eighth Street and East Avenue. Two pipes actively discharge sewer at the GB#4
location (denoted in this report as 4a and 4b). GB#4a is a 200mm diameter outfall while GB#4b is a
450mm diameter outfall. There are no known overflows in the GB#4 sewershed.
1.2.6 GB#5
A small area bounded by CBRM PID 15437718 to the west, 4th Street to the north and 1st Street to
the south makes up the sewershed for GB#5. The sewershed is serviced by a gravity network that
outfalls approximately 180m north east of the end of 1st Street. The outfall is 300mm in diameter
and is located within the existing bank, above the shoreline.
1.2.7 GB#6
The GB#6 sewershed accounts for the majority of the Table Head, Sterling and Beacon Street areas.
The area is serviced by a gravity network that conveys to a 375mm diameter outfall, located at the
end of Roost Street. The outfall does have one issue. The location is heavily impacted by wave
action and erosion causing several sections of the pipe to be lost.
1.2.8 GB#7
GB#7 is located next to GB#6. The outfall services a gravity network that picks up flow from North
Street, Ocean Avenue and adjacent side streets. The outfall is 400mm in diameter and is located
within the existing bank near the end of Roost Street.
1.2.9 GB#8
The final active outfall in the existing Glace Bay sewer system is GB#8. The outfall receives
approximately 85% of the sanitary sewer flow generated in the Town of Glace Bay. The outfall is a
1400mm diameter, concrete encased polyethylene pipe that extends 85m beyond the top of the
existing embankment on PID 15864085, near the mouth of Glace Bay Harbour. The sewer system
employs a combination of gravity and pumped systems. There are 5 pump stations within the GB#8
sewershed. Locations and details for each station follow:
®Reserve Street – located 200m east of the Haulage Road intersection across the street from
the Cadegan Brook Wetland
o Recently upgraded;
o Does not have backup power;
o Has 4 emergency overflows located as follows:
§From the lift station to adjacent mine workings,
§At Reserve Street at the brook,
§At Haulage Road, and
§Adjacent to Wilson Road (in the woods), at MH 21 on Drawing 6 of the
Reserve Mines Sewage Disposal System Drawings by C.A. Campbell and
Associates dated 1974;
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 4
o Included in CBRM’s SCADA network;
o Large suction lift pump station; and,
o Conveys flow to a high point on Reserve Street (near Turner Street).
®McLeods Road – located 130m north of the Dominion Street intersection
o Above ground suction lift pump station;
o To be upgraded in the 2018 construction season;
o The upgrade will include backup power;
o Has an emergency overflow;
o Included in CBRM’s SCADA network; and
o The station conveys flow to Dominion Street, 700m east of its location.
®Brookside Street- located across the street from the Sunset Drive intersection
o Submersible pump station;
o To be moved and upgraded as part of an intersection project in the near future;
o Does not have backup power;
o No known overflows;
o Not included in the CBRM SCADA network; and
o The station conveys to a manhole on Brookside Street, 50m to the east.
®Lake Road – located at the eastern end of Lake Road
o Above ground suction pump station
o To be upgraded during the 2018 construction season;
o The upgrade will include backup power;
o Has an overflow that is directed to a septic tank;
o Included in the CBRM SCADA network;
o A new forcemain will also be installed as part of the upgrade; and
o The station conveys to a high point 900m westward on Lake Road.
®South Street – located at the eastern end of South Street.
o Recently upgraded;
o Submersible station;
o Does not have backup power;
o May have a flow meter installed within the next construction season and will be
included in the CBRM SCADA network; and
o The station conveys 550m upstream on South Street.
Besides the aforementioned emergency overflows located at the lift station sites, there are 5
additional known overflows in the GB#8 sewershed. The additional overflow locations are as
follows:
®Located on the cross-country sewer between Lorway Street and Dominion Street;
®2 overflows located at Renwick Brook; and
®An overflow that utilizes the former outfall at Water Street.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 5
CHAPTER 2 DESIGN PARAMETERS &STANDARDS
2.1 General Overview
The development of an appropriate wastewater interceptor system for each of the communities is
highly dependent upon the selection of appropriate design parameters. HEJV has reviewed
applicable design standards and legislation and has developed the preliminary design of the
collector sewers to meet and exceed these industry standards.
2.2 Design Standards
The design of the interceptor system therefore has been based on the following reference
documents and standards:
®Atlantic Canada Wastewater Guidelines Manual for Collection, Treatment, and Disposal
(ACWGM) (Environment Canada, 2006); and
®Water Environment Federation: Manual of Practice FD-4, Design of Wastewater and
Stormwater Pumping Stations.
The key design criteria that have been established for this project are presented in Table 2-1 and
Table 2-2.
Table 2-1 Sewer Design Criteria
Description Unit Design Criteria Source Comments
Hydraulic Capacity l/s Location dependent HEJV Flow has been set utilizing
3xADWF.
Material for forcemains PVC, HDPE or ductile iron
pipe with the specified
corrosion protection
CBRM See discussion in Chapter 5
Minimum forcemain velocity m/s 0.6 ACWGM For self-cleansing purposes
Forcemain minimum depth of
cover
m 1.8 ACWGM Subject to Interferences
Material of gravity pipe PVC or Reinforced
concrete
CBRM See discussion in Chapter 5
Hydraulic design gravity Manning’s Formula ACWGM n = 0.013
Hydraulic design forcemain Hazen Williams Formula ACWGM C = 120
Maximum spacing between
manholes
m 120 for pipes up to and
including 600 mm and 150
for pipes over 600 mm
ACWGM
Gravity pipe minimum design
flow velocity
m/s 0.6 ACWGM
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 6
Description Unit Design Criteria Source Comments
Gravity pipe maximum flow
velocity
m/s 4.5 ACWGM
Pipe crossings separation mm 450 minimum Minimum separation must
also meet Nova Scotia
Environment (NSE)
requirements.
Horizontal pipe separation
forcemain to watermain
m 3.0 NSE
Horizontal pipe separation
gravity pipe to water main
m 3.0 ACWGM Can be laid closer if the
installation meets the
criteria in Section 2.8.3.1
Gravity pipe minimum depth
of cover
m 1.5 HEJV Subject to Interferences
Gravity pipe maximum depth
of cover
m 4.5 HEJV Subject to Interferences.
Increased depth may be
considered where
warranted
Table 2-2 provides a summary of the key design criteria for the Pumping Stations.
Table 2-2 Pumping Station Design Criteria
Description Unit Design Criteria Source Comments
Pump cycle time 1 hour 5 < cycle <10 WEF/
ACWGM
Number of pumps Minimum of two. Must be
able to pump design flow
with the largest pump out
of service.
ACWGM Three minimum for stations
with flows greater than 52
l/s.
Inlet sewer One maximum ACWGM Only a single sewer entry is
permitted to the wetwell.
Header pipe diameter mm 100 minimum ACWGM
Solids handling mm 75 (minimum)ACWGM Smaller diameter
permissible for macerator
type pumps.
Emergency power
generation
To be provided for firm
capacity of the facility.
ACWGM Can employ overflow
options per 3.3.1. Option to
run one pump if conditions
of 3.3.5.1 are met.
Pump station wetwell
ventilation
Air
changes/
hour
30 (Wetwell)
12 (Valve Chamber)
ACWGM Based on intermittent
activation when operating
in the wet well.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 7
CHAPTER 3 WASTEWATER INTERCEPTOR PRE-DESIGN
3.1 General Overview
Drawings of the existing Glace Bay collection system were appended to the Base Information
Summary Brief that was previously submitted by HEJV. The drawings were created using background
data collected from various sources to depict the layout of the existing gravity and pressure pipe
routing, pump stations and outfalls.
The proposed wastewater interceptor system for Glace Bay will include 2,800 metres of gravity
sewer interceptors to consolidate eight existing outfalls and redirect flow to the proposed
Wastewater Treatment Plant (WWTP) site. A total of four sewage pump stations will be required to
deliver wastewater to the new treatment facility, with the final, LS-GB4 being integrated into the
proposed WWTP. Approximately 2,000 metres of new sanitary forcemain will be required.
For this Pre-Design Brief, HEJV has compiled preliminary plan and profile drawings of the proposed
linear infrastructure. Pump station, Combined Sewage Overflow (CSO), outfall and WWTP locations
have also been illustrated on the drawings and are included in Appendix A.
3.2 Design Flows
HEJV completed a review of the theoretical and observed sanitary flows for the future combined
Glace Bay sewershed. The purpose of the assessment was to estimate average and design flows for
the environmental risk assessment (ERA) and the preliminary design of the future WWTP and
interception system.
3.2.1 Theoretical Flow
Theoretical flow was calculated based on design factors contained in the ACWGM. To estimate
population, the number of private dwellings were estimated then multiplied by an average
household size. An average value of 2.2 persons per household was used based on the average
household size found in the 2016 Statistics Canada information for Cape Breton. The number of
apartments, nursing homes, townhouses, and other residential buildings were estimated and
considered in the population estimate. Population estimates are shown in Table 3-1. Peak design
flow was calculated using the following equation (1):
ܳ(݀)=ܲݍܯ
86.4 +ܫܣ (1)
Where:
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 8
Q(d) = Peak domesƟc sewage flow (l/s)
P = PopulaƟon (in thousands)
q = Average daily per capita domesƟc flow (l/day per capita)
M = Peaking factor (Harman Method)
I = unit of extraneous flow (l/s)
A = Subcatchment area (hectares)
ACWGM recommends an average daily domestic sanitary flow of 340 l/day per person for private
residential dwellings. The unit of extraneous flow was assumed to be approximately 0.21 l/s/ha
based on typical ranges outlined in ACWGM. The peaking factor used in Equation 1 was determined
using the Harman Formula (2) shown below:
Harmon Formula
ܯ =1+14
4+ܲ.ହ (2)
The estimated average dry weather flow (ADWF) and peak design flows based on the ACWGM
methods discussed above are presented in Table 3-1.
Table 3-1 Theoretical Flow Summary
Station Estimated Area
(ha)
Estimated
Population1 ADWF2 (l/s)3x ADWF
(l/s)
Peak Design Flow3
(l/s)
GB2 37 774 3.05 9.15 19.94
GB6 46 1188 4.68 14.04 27.67
GB7 13 303 1.19 3.57 7.83
May/ York 157 4433 17.45 52.35 92.02
Park 146 2900 11.41 34.23 71.30
Main 111 2206 8.68 26.04 55.04
1 2016 Cape Breton Census from StaƟsƟcs Canada
2Based on average daily sewer flows of 340 L/day/person (ACWGM 2006)
3EsƟmated using ACWGM equaƟon for peak domesƟc sewage flows (including extraneous flows and peaking factor)
3.2.2 Initial Observed Flows
Data from six flow monitoring stations was utilized as part of an initial flow monitoring program,
three of which (GB2, 6, and 7) were installed within sewersheds that correspond to the location of
proposed pump stations LS-GB1, LS-GB2 and LS-GB3. The remaining three stations were deployed
within the sewershed for LS-GB4, to be located within the proposed WWTP footprint. The dates of
the deployments range as several of the stations were deployed during a previous CBCL sewer
separation project. A summary of the flow meter deployment locations and monitoring duration is
provided in Table 3-2.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 9
Table 3-2 Flow Monitoring Location Summary
Station Street Name Northing Easting Monitoring Start-End Dates Days
of Data
GB2 GB-2 Shea's Lane 5120819.237 4618204.218 November 23 –
December 21, 2017 29
GB6 GB-6 Upper North
Street 5119796.697 4619453.604 November 29, 2017 –
January 4, 2018 37
GB7 GB-7 Upper North
Street 5119732.904 4619425.228 November 30, 2017 –
January 4, 2018 36
May/ York May/York St 5117903.868 4618739.961 February 15 –
April 12, 2018 57
Park Park St 5117522.681 4618750.109 March 6 –
April 13, 2018 39
Main 525 Main St 5118664.029 4619497.118 February 16 –
April 12, 2018 57
Analysis for observed dry weather flows were completed using the United States Environmental
Protection Agency’s (EPA) Sanitary Sewer Overflow Analysis and Planning (SSOAP) toolbox. The
SSOAP toolbox is a suite of computer software tools used for capacity analysis and condition
assessments of sanitary sewer systems. This analysis was completed for all six monitoring stations.
Flow and precipitation data were input into the SSOAP program, along with sewershed data for each
of the metered areas. To determine average dry weather flow (ADWF), days that were influenced by
rainfall were deleted. This was done in the SSOAP model by removing data from days that had any
rain within the last 24 hours, more than 5 mm in the previous 48 hours, and more than 5 mm per
day additional in the subsequent days (e.g. 10 mm in the last 3 days).
The calculated ADWF estimates based on monitored flow data evaluated using the SSOAP program
are presented in Table 3-3, along with average, 3xADWF and peak flow amounts from raw
monitored data. Please note that the value of 3xADWF was recommended by UMA Engineering
Limited as the minimum sewage flow rate that should be treated for Glace Bay in the report
“Industrial Cape Breton Wastewater Characterization Program – Phase II” prepared in 1994.
Table 3-3 Average Dry Weather and Design Flows Results
Monitoring Station ADWF From SSOAP
Model (l/s)
3x ADWF
(l/s)
Average Daily
Observed Flow (l/s)
Peak Daily
Average Flow
(l/s)
GB2 7.5 22.5 9.45 40.75
GB6 5.5 16.5 10.00 59.76
GB7 1.7 5.1 2.87 13.58
May/ York 59.1 177.3 78.36 184.45
Park 43.1 129.3 47.65 61.62
Main 19.1 57.3 27.44 69.74
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 10
3.2.3 Additional Observed Flows
After a review of the data in Table 3-3, HEJV concluded that for the May/York and Park Stations, that
there may be a large volume of inflow getting into that portion of the existing Glace Bay collection
system due to the witnessed elevated dry weather flows. HEJV proposed that a second flow
monitoring event should be undertaken to re-monitor the two aforementioned stations during the
summer months to provide a confirmation for ADWF calculations. As expected the ADWF values
returned during the summer months were significantly lower than the ADWF figures determined
from the spring event. Location summary and design flow data for the summer flow monitoring
session is presented below in Tables 3-4 and 3-5 below.
Table 3-4 Flow Monitoring Location Summary
Station Street Name Northing Easting Monitoring Start-End Dates Days
of Data
May/ York May/York St 5117903.868 4618739.961 July 27 –
August 31, 2018 35
Park Park St 5117522.681 4618750.109 August 6 –
September 7, 2018 32
Table 3-5 Additional Average Dry Weather and Design Flows Results
Monitoring Station ADWF From SSOAP
Model (l/s)
3x ADWF
(l/s)
Average Daily
Observed Flow (l/s)
Peak Daily
Average Flow
(l/s)
May/ York 35.73 107.19 36.02 75.76
Park 20.07 60.21 21.85 48.34
3.2.4 Flow Conclusions & Recommendations
Based on the analysis presented in the above sections the ADWF for the proposed pump stations
were inferred based on linear interpolation of flow versus population and flow versus sewershed
area. Inferred flows were only prepared for areas that are not included in the metering locations.
Pump stations which incorporate flow from monitored locations used the ADWF values presented in
Table 3-3. The total ADWF at each proposed pump station location is presented in Table 3-6.
It is important to note that the sewershed area and the population contributing to the May/ York,
Park and Main monitoring stations are substantially larger than areas and populations contributing
to proposed pump stations LS-GB1 to LS-GB3. The May/York, Park and Main stations are located in
sewersheds further south, which do not contribute to the three aforementioned interceptor pump
stations. For these reasons these flow monitoring stations were omitted from the linear
interpolation for the design flows calculated for LS-GB1 to LS-GB3. For the final pump station (LS-
GB4 – located within the proposed WWTP), the Main Street Station and summer flow data for the
May/York and Park Street monitoring stations were utilized as these stations were placed in the
sewer shed area that contributes directly to LS-GB4 (WWTP). As the two monitoring sessions
proved, there is a large influx of inflow into the existing Glace Bay collection system, and therefore
the pump station would be greatly oversized if the spring data was used. It is HEJV’s understanding
that CBRM would prefer to minimize inflow and infiltration, versus oversizing infrastructure.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 11
Table 3-6 Average Dry Weather Summary for Proposed Pump Stations
Station Total
Population1
Total Area1
(ha)
ADWF based on
Population2(l/s)
ADWF based on
Area2 (l/s)
LS-GB1 630 37.34 4.36 5.65
LS-GB2 881 41.96 9.50 8.53
LS-GB3 3857 177.29 26.42 27.27
LS-GB4 -
WWTP
11791 855.71 140.51 128.40
1 Only considers populaƟon and area not included in monitoring locaƟons
2Values calculated based on linear interpolaƟon plus any addiƟonal flows
The recommended design flows presented below in Table 3-7 are based on 3xADWF values using
the more conservative interpolated values (i.e. between population and area interpolation). Based
on this analysis, HEJV’s recommended interceptor design flows for the interception and treatment
systems are presented in Table 3-7. Please note that the value presented below for LS-GB4 was
increased by 5%. After the second monitoring event was completed, it was found that a manhole
upstream of the Main Street flow meter had two outlet pipes. HEJV made a worst case assumption
that the flow split evenly out of this manhole. This would account for an additional 3.5% increase to
the ADWF for the system. To be further conservative, we have allowed for a 5% increase to the LS-
GB4 recommended design flow.
Table 3-7 Recommended Interception Design Flow Rates at Pump Stations
Station Recommended Design
Flow (l/s)1
LS-GB1 16.95
LS-GB2 28.50
LS-GB3 92.75
LS-GB4 -WWTP 442.602
1 Based on 3 x ADWF, includes both metered and interpolated flows
2 Value increased by 5% as noted above.
To evaluate performance of the proposed pump station during wet weather conditions, metered
flows during rainfall events have also been considered for contributing stations. The results of the
wet weather flow assessment at metered locations are presented in Table 3-8.
Table 3-8 Observed Flows during Rainfall Events
Monitoring Station
Minor Rainfall Events
(Daily Rainfall of 10-25 mm)
Moderate Rainfall Events
(Daily Rainfall of >25 mm)
# of Events Daily Average
Flow (l/s)# of Events Daily Average
Flow (l/s)
GB2 3 16 2 41
GB6 5 20-23 1 60
GB7 6 3-6 1 14
May York 8 80-185 1 76
Park 7 53-62 1 48
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 12
Monitoring Station Minor Rainfall Events
(Daily Rainfall of 10-25 mm)
Moderate Rainfall Events
(Daily Rainfall of >25 mm)
Main 5 46-70 0 N/A
Average daily wet weather flow at each pump station was inferred based on linear interpolation of
sewershed size and metered wet weather flows. Inferred wet weather flows are presented in Table
3-9. The calculated flows were compared to the recommended design flows to indicate if sewer
overflow conditions would be expected.
Table 3-9 Inferred Flows during Rainfall Events
Pump Station
Minor Rainfall Events
(Daily Rainfall of 10-25 mm)
Moderate Rainfall Events
(Daily Rainfall of >25 mm)
Inferred Daily
Average Flow (l/s)
Expected Overflow1
(Y/N)
Inferred Daily
Average Flow
(l/s)
Expected Overflow1 (Y/N)
LS-GB1 17 N 45 Y
LS-GB2 18 N 43 Y
LS-GB3 79 N 210 Y
LS-GB4 -WWTP 355 N 587 Y
1 Overflow expected when observed flow exceeds design flow presented in Table 3-9
To consider the effects of moderate rainfall, daily rainfall for the Sydney CS climate station
(Environment Canada Station #8207502) was reviewed for the past 10 years of complete data (2008
- 2017). Review of these data suggests that moderate rainfall events (i.e. daily rainfall greater than
25 mm) is expected to occur frequently within a given year. Based on this review, it is expected that
these moderate rainfalls events would occur on average between 10 and 15 times each year and
therefore overflow may be expected during these events.
Rapid snow melt may lead to additional overflow events, the occurrence of which would largely be
confined to the spring freshet season. According to the U.S. Environmental Protection Agency, peak
rainfall events establish peak sewer flows rather than snow melt (EPA 2007). This is reasonable
since snow is temporarily stored within the watershed as snow pack and gradually melts over time
(i.e. rather than sudden peak flows generated by intense rain).
Mean daily temperatures were reviewed during wet periods to consider the impacts of snow
accumulation and melt during the winter observation period. Mean temperatures were found to
be above 0oC for the precipitation events considered in this study. A few of the events occurred
with temperatures close to 0oC and are likely to have fallen as a rain-snow mix. Given these
relatively mild temperatures, it is expected that the SSOAP analysis generally accounted for snow-
melt wet weather inputs in estimating dry weather flows.
3.3 Interceptor System
The proposed interceptor system for the Glace Bay WWTP is presented on the plan and profile
drawings attached in Appendix A. The proposed interceptor system is made up of segments of
pressure and gravity sewers, pump stations and combined sewer overflows.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 13
The first step in laying out the interceptor sewer route was to determine the location of the future
WWTP that will serve the Town of Glace Bay. The location for the proposed WWTP was initially
selected near the breakwater at the mouth of Glace Bay Harbour, adjacent to North Street. This
location was selected as 85% of Glace Bay’s wastewater discharge is currently directed toward the
site and has been the location reviewed by several previous studies. The downfall for the location is
the proximity to residential and commercial development. The location does not meet the ACWGM
guidelines for setback distances from residential and commercial properties. As part of our pre-
design efforts, HEJV met with NSE to discuss locations for future treatment plants that do not meet
the ACWGM guidelines for setback distances but ultimately make the most sense for a community
from an economic stand point. NSE’s feedback to HEJV was that if the location of the WWTP did not
meet the ACWGM guidelines but ultimately made the most sense for a community, the detailed
design of the plant would need to include odour controls, to minimize the impact to neighbouring
properties. During the development of the Glace Bay WWTP Pre-Design, it was determined that the
site near the breakwater should be reconsidered. The required footprint of the Glace Bay WWTP
was too large for the original site. A second site was reviewed and recommended to CBRM. The site
was located across Lower North Street from the original location, adjacent to the BayPlex facility.
The site would still be located near the GB#8 outfall, but would require a pump station to convey
flows from GB#8 to the WWTP site.
Considering Glace Bay is a former mining town, the next step to finalize the plant location was a
geotechnical review of the two proposed sites. Several geotechnical programs were completed on
the two sites including a rock mechanics evaluation, as the presence of voids were verified at the
proposed site adjacent to the BayPlex. The Geotechnical Reporting concluded that the site nearest
the breakwater provided for a low risk location for the WWTP. No voids were found on the site
adjacent the breakwater during the intrusive investigations. Therefore from a risk perspective, HEJV
decided against the aforementioned revised location, and decided that the GB WWTP would be best
suited to the original location near the breakwater. HEJV recommends further geotechnical
exploration be completed at this site to fully review the risk level of developing the WWTP at the
proposed location. It should be noted that there are records that indicate mining may have occurred
at the site adjacent to the breakwater also and should be fully reviewed prior to the commencement
of detailed design.
3.3.1 Option Analysis
For the majority of the analysis on routing, HEJV concentrated on locating routes that minimized the
length of the completed interception system. Routes were analyzed and the shortest, most
effective route was selected as the best option and carried forward in the preliminary design. A
detailed analysis was completed on one route involving a decision between a pump station (located
on CBRM PID 15437718) with a corresponding forcemain and a deeper gravity route (along West
Avenue to Tennyson Street). Costs for each of the route were compared. The pump station for the
site would have been a sizeable development with an approximate construction value of $1.0
million. It was the cost of the pump station in combination with the required forcemain and air
release valve chamber that outweighed the cost to construct the deeper gravity network shown.
Therefore the deeper gravity sewer was selected and carried forward in the preliminary design.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 14
3.3.2 Interceptor System Breakdown
The interceptor network will divert sewer from eight existing outfalls to the proposed WWTP site.
The major elements of the system include:
®LS-GB 1 located near the GB#1 outfall, on PID 15441355. This pump station conveys flow
eastward through a common forcemain that extends to Centre Avenue. The forcemain from
LS-GB1 to LS-GB2 is 150mm in diameter. From LS-GB2 eastward, the forcemain diameter
increases to 200mm in diameter.
®LS-GB2 is located behind Shea’s Lane and Eleventh Street on PID 15440969. This pump
station intercepts flow from outfalls GB#2 and GB#3. The pump station conveys discharge
via a 200 mm diameter forcemain to the common forcemain discussed above.
®A gravity sewer that begins as a 200mm and terminates as a 450mm diameter gravity main
conveys sewage along Centre Avenue and Eighth Street.
®Flow from the GB#4A outfall is intercepted by a 200mm diameter gravity main and is
directed to a proposed CSO chamber located near the Eighth Street and East Avenue
intersection.
®Flow from the GB#4B outfall is intercepted by a 450mm diameter gravity main and is
directed to the same CSO chamber located near the Eighth Street/East Avenue intersection.
®A 450mm diameter gravity sewer conveys the intercepted flow cross country from the CSO
toward First Street.
®A 200mm diameter sewer will be required near the 2nd Street/Hub Avenue intersection to
intercept flow from GB#5 to the interceptor system located near First Street.
®From the connection with the 2nd Street sewer, a gravity sewer extends from First Street
across PID 15437718. The sewer runs along West Avenue, Tennyson Street and Vivian Street
to Upper North Street, eventually to the LS-GB3 site.
®A small section of 450mm diameter gravity sewer connects GB#6 to GB#7. The flow from
the gravity sewer is directed to a CSO chamber (CSO-5).
®Flow from CSO-5 is merged with the gravity interceptor sewer on Upper North Street and is
directed to LS-GB3.
®LS-GB3 handles all of the flow from each of the seven outfalls north of the Glace Bay WWTP
site.
®LS-GB3 conveys sewage to the proposed WWTP via a 250mm diameter forcemain.
®LS-GB4 (located within the GB WWTP footprint) intercepts sewer from the GB#8 outfall. The
WWTP site will be complete with a CSO overflow structure that will convey overflow to the
proposed outfall.
®Outside of the interceptor sewer, one home at the end of 4th Street will require a low
pressure sewer system as it currently discharges directly to the Atlantic Ocean.
3.4 Combined Sewer Overflows
A Combined Sewer Overflow (CSO) should be utilized in the proposed interceptor system where
flows directed to a pump station exceed the interception design rate defined in Section 3.2.3 (Table
3-5). The proposed locations for the chambers have been illustrated on the plan and profile
drawings included in Appendix A.
In general, the interceptor system has been designed for a capacity of 3xADWF. The CSO chambers
depicted on the plan and profile drawings permit the connection to each of the existing outfalls,
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 15
while only permitting the recommended interception design flows (3xADWF) into the proposed
system.
Each of the outfalls in Glace Bay discharge raw sewage to the Atlantic Ocean on a continuous basis.
By installing the interceptor sewer, the amount of raw sewage being directed to the Atlantic Ocean
will be limited. Given the limited number of overflows anticipated, the CSOs for Glace Bay have
been proposed to be an unscreened chamber. The chambers will essentially act as a flow diversion
chamber. The CSO chamber should be complete with a weir plate that will separate the chamber
into two sections, one for normal everyday flows (below 3xADWF) and one for overflow events.
Normal flows would be directed to the interceptor system. As the flow increases above the
interception design flow rate, the level in the CSO chamber will rise, until it crests the weir plate.
Flow that crests the weir plate would be directed back to the original outfall.
The Glace Bay interceptor system will include 6 CSO chambers that will direct flow to various
components of the system. In addition, an overflow should be provided at LS-GB4.
3.4.1 CSO-1
CSO-1 will be located near the GB#1 outfall. This chamber will direct flow to LS-GB1 within the
Interception Rate presented in Section 3.2.3. Flow above the interception rate will overflow back
into the original outfall.
3.4.2 CSO-2
CSO-2 should be located near the GB#2 outfall. The chamber will redirect flow to LS-GB2. Flows
within the interception rate will be directed to the pump station, while overflow events will be sent
back to the original outfall.
3.4.3 CSO-3
CSO-3 should be used to limit the flow from the GB#4 (4a and 4b). Flows within the 3xADWF
criterion should be directed to the gravity sewer. Flows above the 3xADWF rate would overflow, via
a new overflow pipe, back to the Atlantic Ocean. A new overflow pipe has been recommended due
to the topography between the existing 4b outfall and the limited capacity of the 4a outfall.
3.4.4 CSO-4
CSO-4 should be located at the northern end of Second Street. This CSO should be used to divert
flow within the intercepted rate from the GB#5 outfall to the gravity sewer that runs perpendicular
to First Street. Again, flows above the interception rate should be overflowed back to the original
outfall.
3.4.5 CSO-5
The last CSO in the Glace Bay Interceptor System should be located near LS-GB3. This CSO will
redirect flow from GB#6 and GB#7 within the interception rate to the pump station. Flows greater
than the interception value will be diverted back to the existing GB#7 outfall.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 16
3.4.6 CSO-6
An overflow should be incorporated into the WWTP site. At this time, HEJV recommends an off line
overflow structure that would allow for CSO construction, prior to connecting the structure to the
existing outfall pipe. Overflow events would cause the chamber to surcharge until flow crests the
weir plate. Flow cresting the weir plate would be directed to the new outfall that will serve the
WWTP. The detailed design of the structure will need to take into account current harbour
elevations, future harbour elevations and critical inverts/manhole elevations upstream of the
connection.
3.5 Pumping Stations
As discussed above, four new pumping stations will be required in the proposed Glace Bay
interceptor system to convey wastewater to the proposed WWTP. The pump stations should be
equipped with non-clog submersible pumps with an underground wetwell and a building that will
accommodate the mechanical piping, valves, electrical system, control systems, instrumentation
and in some cases the backup generation system. A hydraulic analysis should be completed on the
forcemain to determine if surge valves are warranted. If required, the valves should be installed
prior to the forcemain exiting the pump station building to protect the pipe against unwanted surge
forces. Standard pump station schematics have been presented in Appendix A for illustrative
purposes.
3.5.1 Pumping Design Capacity
Each Station will be designed to pump the intercepted flows defined in Section 3.2.3 with the largest
pump out of service as per ACWGM. All pumps will be supplied and operated with variable
frequency drives (VFD). A VFD will provide the following benefits to the pumping system:
®Energy savings by operating the pump at its best efficiency point;
®Prevent motor overload;
®Energy savings by eliminating the surge at pump start up; and
®Water hammer mitigation.
3.5.1.1 WALLACE ROAD LS-GB1
The Wallace Road pump station will convey flow from the GB#1 sewershed, to the gravity sewer
system on Centre Ave, via a 100mm diameter forcemain. This forcemain will create a common
header with LS-GB2 (200mm diameter). The pump station will be a duplex station, with one duty
and one standby pump. The pumps will have a capacity of 29 l/s, with a TDH of 19m.
3.5.1.2 ELEVENTH STREET LS-GB2
The Eleventh Street pump station will convey flow from the GB#2 sewershed, via the common
header forcemain described above (200mm diameter). Flow from the forcemain will be discharged
to the gravity sewer on Centre Ave. The pump station will be a duplex station, with one duty and
one standby pump. These pumps will have a capacity of 38 l/s, with a TDH of 16 m.
3.5.1.3 UPPER NORTH STREET LS-GB3
The Upper North Street pump station will receive the intercepted flows from CSO-5 and the gravity
sewer from Vivian Street. Discharge from the station will be conveyed to the gravity sewer on Lower
North Street via a 250mm diameter forcemain. The pump station will be a triplex station, with two
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 17
duty and one standby pumps. These pumps will have a combined capacity of 93 l/s, with a TDH of 27
m.
3.5.1.4 WWTP -LS-GB4
LS GB4 will receive the intercepted flows from the existing GB#8 outfall and be located within the
footprint of the proposed WWTP. The pump station will be a quadraplex station, with three duty
and one standby pumps. The duty pumps will have a combined capacity of 444 l/s, with a TDH of 12
m.
3.5.1.5 PUMP STATION SUMMARY
Table 3-10 Pump Station Summary
Pumping Station
Wallace
Road
LS-GB1
Eleventh
Street
LS-GB2
Upper
North
Street
LS-GB3
WWTP
LS-GB4
Duty Pumps 1 1 2 3
Standby Pumps 1 1 1 1
ADWF (l/s)5.65 9.5 27.27 140.51
Maximum Design Flow (l/s)16.95 28.5 92.75 442.6
Pump Capacity (l/s, each pump)17 29 93 444
Forcemain Diameter (mm)100 150 250 600
TDH (m) at Maximum Design Flow 43 19 27 12
Velocity (1 pump running) m/s 2.06 1.82 1.53 1.52
Approximate power requirement (each pump) kW 22 11.2 22 26
3.5.2 Safety Features
Each station should report alarm conditions to the CBRM SCADA network. The stations should also
incorporate external visual alarms to notify those outside of building of an alarm condition. External
audible alarms should not be used as the station is in a populated area and disturbance to the local
community should be kept to a minimum.
All access hatches should include safety grating similar to Safe-Hatch by Flygt.
3.5.3 Wetwell
Each of the wetwells should be constructed with a benched floor to promote self-cleansing and to
minimize any potential dead spots.
The size of each wetwell should be based on factors such as the volume required for pump cycling,
dimensional requirements to avoid turbulence problems, the vertical separation between pump
control points, the inlet sewer elevation, capacity required between alarm levels, overflow
elevations, the number of pumps and the required horizontal spacing between pumps.
The operating wetwell volumes for the pumping stations should be based on alternating pump
starts between available pumps while reducing retention times to avoid resultant odours from
septic conditions.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 18
At this time HEJV recommends a precast unit for each station. Based on the conditions discussed
above, the sizing for each of the wetwells is presented below.
Table 3-11 Wetwell Sizing Summary
Pumping Station Size and Shape
(m)
Depth
(m)
Wallace Road LS-GB1 2.1 Circular 4.6
Eleventh Street LS-GB2 2.1 Circular 8.9
Upper North Street LS-GB3 2.4 x 3.6 Rectangular 4.1
WWTP LS-GB4 5.9 x 2.9 Rectangular 12.0
3.5.4 Station Piping
Pump station internal piping should be ductile iron class 350 with coal tar epoxy lining or stainless
steel with diameters as indicated in Table 3-10. Threaded flanges or Victaulic couplings should be
used for ductile iron pipe joints, fittings and connections within the station. Pressed or rolled
vanstone neck flanges should be used for stainless steel pipe joints, fittings and connections. Piping
layout should be designed to provide minimum friction loss and to provide easy access to all valving,
instrumentation and equipment for the operators.
A common flow meter on the discharge header should be provided for each station to monitor
flows.
3.5.5 Equipment Access
At the duplex stations, pump installation and removal for the stations should be achieved using a
lifting davit and electric hoist that would access the pumps through hatches located above the
pumps. Due to maintenance issues associated with exterior davit sockets and portable davits,
stationary lifting davits should be installed inside these pump stations and accessed through a roll
up door. At the triplex and quadraplex stations, pump installation and removal should be achieved
using a monorail structure with an electric hoist located inside a weathertight structure.
A heated building should be provided for the pump station to eliminate maintenance issues with
valve chambers. All valves and instrumentation should be above ground in the heated building to
allow for easy access and maintenance.
3.5.6 Emergency Power
All stations with the exception of GB-LS4 should be equipped with a backup generator sized to
provide power to all equipment, lights, and other accessories during power interruptions. An
automatic power transfer switch should transfer the station’s power supply to the generator during
a power disruption and should return to normal operation when power has been restored. The
generator should be supplied with noise suppression equipment to limit disruption to existing
neighbours. Due to its location, emergency power for LS-GB4 should be provided by the backup
power supply from the WWTP.
If a diesel generator is selected, the fuel tank should be integral with the generator and designed to
meet the requirements of the National Fire Code of Canada,Section 4 and should meet the
requirements of the Contained Tank assembly document ULC-S653.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 19
As previously discussed, each pump station site will include a heated building. HEJV has reviewed
the LS-GB1 to LS-GB3 sites with respect to housing the backup generator inside the building versus
an outside unit designed for exterior service with a weather resistant enclosure. Ultimately the final
location for each of the generators was based on economics. If the building to be included could be
modified to house the generator for less than the cost of the exterior weather resistant enclosure,
then the unit was proposed to be located inside. HJEV proposed that the back-up generation
equipment for the three noted stations should be located inside their respective pump station
buildings.
3.5.7 Controls
Equipment should be controlled through a local control panel mounted in each of the pump station
buildings. The local control panel would be a custom panel designed to be integrated into the CBRM
SCADA network. The panel should provide a Hand/Off/Auto control selector to allow for manual
control of the station. The control system should report remotely to CBRM’s SCADA system
including alarm conditions.
Control instrumentation and equipment should include the following:
®Level sensors/transmitters in the wetwell
®Flow meter/transmitter on the discharge forcemain(s)
®Pressure transmitter
®Surge valve position indication (if required)
®Level alarms
®Unauthorized building access
®Low fuel level
®Pump or generator fault
®Generator operation
®CSO level controls (either side of weir plate)
The level in the wetwell utilizing ultrasonic level instruments should control the operation of the
pumps. Auxiliary floats will provide high and low level alarms as well as back-up control in the event
of a failure in the ultrasonic equipment.
3.5.8 Security
Security fencing will be installed at the pumping station on the boundary of the land parcel. The
structures will be monitored with an alarm system (via SCADA) to identify unauthorized access.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 20
CHAPTER 4 EXISTING COLLECTION SYSTEM UPGRADES
4.1 Sewage Pump Station Upgrades
HEJV has reviewed the existing Glace Bay Collection System for potential upgrades to the existing
sewage pumping stations. There are currently six pump stations in the community of Glace Bay. The
age of the existing stations vary. All of the stations have been upgraded previously. Since 2015,
upgrades have been performed to 4 of the 6 existing stations. The remaining two stations were
upgraded in 2011. The Glace Bay WWTP has been classified as a high priority system and has an
implementation deadline of 2021. Plans should be made to upgrade stations that have not been
recently renewed, including the Reserve Street and Railroad Street pump stations (upgraded in
2011). Due to their age, the condition of each station should be verified at the time of detailed
design to determine if an upgrade of the existing station is required.
4.2 Asset Condition Assessment Program
To get a better sense of the condition of the existing Glace Bay sewage collection system, HEJV
recommends completing a sewage collection system asset condition assessment program in the
community. The program would carry out an investigation involving two components:
®Visual inspection and assessment of all manholes in the collection system
®Video inspection of 20% of all sewers in the system
The program should be completed with the issuance of a Collection System Asset Condition
Assessment Report that would summarize the condition of the various assets inspected and include
opinions of probable costs for required upgrades.
4.3 Sewer Separation Measures
CBRM should consider completing further sewer separation investigation efforts in Glace Bay. The
program would review catch basins that are currently connected or possibly connected to existing
sanitary sewers. The program should also include the costing of the installation of new storm
sewers to disconnect catch basins from the existing sanitary sewer.
4.4 CSO Station Outfall Upgrades
Upgrades should be provided at existing outfalls that will be utilized as overflows from the proposed
CSO Stations. A connection should be made with the existing outfall that would allow the pipe to be
extended into the marine environment versus conveying overflow through the existing shoreline
embankments (above shoreline elevation).
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 21
CHAPTER 5 FORCEMAIN SELECTION AND DESIGN
5.1 Pipe Material
Four pipe materials (Ductile Iron, HDPE, PVC, and Reinforced Concrete) were considered for this
project and were evaluated against various factors. Ductile Iron, HDPE and PVC were reviewed for a
suitable forcemain material for the project. PVC and Reinforced Concrete were reviewed against
each other for a suitable gravity pipe material. A summary of the advantages and disadvantages of
the different materials is presented in Table 5-1.
Table 5-1 Comparison of Pipe Materials
Pipe
Material Advantages Disadvantages
Ductile Iron
·Is forgiving with regard to problems
caused by improper bedding
·Thinnest wall, greatest strength
·Standard testing method
·CBRM staff and contractors are familiar
with installation of DI forcemains
·Pipe, and fittings are susceptible to corrosion
·High weight
·Installation cost is high
HDPE
·Excellent corrosion resistance of pipe
·Long laying lengths (where practical)
·Relatively easy to handle
·Requires good bedding
·Requires butt fusing
·Careful handling is required due to abrasion
·Long distances of open trench
·Not designed for vacuum conditions
·Installation cost is high if long lay lengths are
not possible
PVC
·CBRM standard
·Excellent corrosion resistance of pipe
·Standard testing method
·Light weight
·High impact strength
·CBRM staff and contractors are familiar
with installation of PVC forcemains
·Cost competitive
·Requires good bedding
·Must be handled carefully in freezing
conditions
Reinforced
Concrete
·High strength
·Standard testing method
·CBRM staff and contractors are familiar
with installation
·Heavy – harder to handle
·Susceptible to attached by H2S and acids
when not coated
·Requires careful installation to avoid
cracking
·Short laying lengths
Based on the above comparison, HEJV recommends that the gravity sewer and forcemain piping for
the Glace Bay interceptor sewer be PVC.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 22
CHAPTER 6 LAND AND EASEMENT REQUIREMENTS
HEJV has reviewed the requirements for land acquisition and easements. The majority of the
proposed system, gravity sewers and forcemains and one of the pump station sites will be
constructed within public right-of-ways or on CBRM owned properties. However, some of the
proposed linear infrastructure, pump stations, CSOs and the treatment plant are shown on private
and federal lands.
6.1 Pump Station Sites
HEJV proposes that the land parcels for each of the pump station sites be purchased due to the
development being a permanent above ground structure requiring regular access from CBRM staff.
HEJV considers easements to be an acceptable option to both CBRM and current land owners for
the construction and maintenance of the interceptor linear infrastructure.
Find below a summary of the required land acquisitions that should be undertaken to permit the
installation of the required pump station infrastructure. The table below lists the PID, property
owner, assessed value, size of parcel required and whether or not HEJV recommends purchasing the
entire lot. In some circumstances, due to the size of the lot, it might make more sense to purchase
the entire lot from the existing land owner, versus negotiating a piece that would considerably limit
the development on the remaining site. For two of the stations, HEJV has indicated that CBRM
should try to negotiate an easement on two of the PWGSC lots for lift station infrastructure. As
these lots would experience a fair amount of erosion, CBRM may not want to take on the costs of
future erosion control, and an easement may be in CBRM’s best interest.
Table 6-1 Pump Station Land Acquisition Details
PID Property Owner Assessed
Value Description Size Required
Purchase
Entire Lot
(Y/N)
154413551 PWGSC $10,100 LS-GB1/CSO Site 15mX70m N
15440969 PWGSC $17,500 LS-GB2/CSO Site 60mX80m(irreg.)N
15739113 Road Parcel Owner
Undetermined
LS-GB3/CSO Site 15mx30m Y
1 Additional easement required for linear infrastructure, see Table 6-2 for further details on size requirements.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 23
6.2 WWTP Site
The proposed WWTP will be located near the existing GB 8 outfall, as discussed in Chapter 3. The
development will require the partial purchase of two parcels of land. Presented below in Table 7-2
are some of the pertinent details of the parcel of land required to build the WWTP.
Table 6-2 WWTP Land Acquisition Details
PID Property
Owner
Assessed
Value Description Size Required
Purchase
Entire Lot
(Y/N)
15524473 PWGSC $5,900 WWTP Site To be confirmed in the WWTP Pre-
Design
N
15408867 Hopkins H Ltd $130,300 WWTP Site To be confirmed in the WWTP Pre-
Design
N
6.3 Linear Infrastructure
The installation of linear infrastructure will require nine easements through private and federally
owned lands. The remaining linear infrastructure will be installed within public right-of-ways and
CBRM parcels of land. Easements for linear infrastructure should be developed so that a width of
10m can be used during construction and a final easement width of 6m is maintained for future
considerations. Details on the required easement area is as follows:
Table 6-3 Linear Infrastructure Land Acquisition Details
PID Property Owner Assessed Value Description Length
Required
Purchase
Entire Lot
(Y/N)
154413551 PWGSC $10,100 Forcemain 84m N
15441090 PWGSC $25,300 Forcemain 67m N
15440936 Youth for Christ Canada $289,000 Forcemain/
Gravity Sewer
25m N
15526668 PWGSC $16,300 Gravity Sewer 7m N
15437791 PWGSC $44,500 Gravity Sewer 24m N
15437742 PWGSC $8,300 Gravity Sewer 29m N
15531064 PWGSC $400 Gravity Sewer 147m N
15531023 PWGSC $66,300 Gravity Sewer 18m N
15821127 Owner Unknown No Information Forcemain 22m Y
15821119 Charles H Rigby No Information Forcemain 65m Y
1 Additional easement required for pump station infrastructure, see Table 6-1 for further details on size requirements.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 24
CHAPTER 7 SITE SPECIFIC CONSTRAINTS
During the preliminary design of the interceptor system, HEJV has reviewed the pump station sites,
CSO sites and pipe routing for potential constraints. HEJV reviewed construction constraints, access
requirements and power supply requirements for the proposed infrastructure. The next sections of
the Design Brief briefly touch on items that were found during HEJV’s review.
7.1 Construction Constraints
HEJV has reviewed the preliminary design of the interceptor system from a construction constraints
perspective. Construction sequencing will be the primary focus of this discussion. The pump stations
will need to be constructed, tested and commissioned prior to any of the raw discharge being
diverted to the new interceptor system.
A construction constraint exists at the proposed location for the pump station at Upper North Street
(LS-GB3). An open ditch currently traverses the proposed site. A combination of re-routing the ditch
along with a buried culvert may be required to permit the installation of the pump station
infrastructure.
The construction of LS-GB4 and CSO6 will be challenging. With the depth of the proposed pump
station chambers, issues with groundwater and bedrock will likely be encountered.
There will be many crossings with existing sanitary and storm sewer that will need to be carefully
evaluated and planned during the detailed design of the Glace Bay interceptor system. Sections of
the proposed infrastructure will also parallel existing sewer infrastructure. HEJV’s routing has
attempted to minimize the interference between existing and proposed infrastructure.
7.2 Environmental Constraints
The proposed pipe routing will cross two streams between GB#1 and GB#2. Existing stream
crossings at Station 0+010 and Station 0+430 will involve a crossing with an active stream.
Construction of the works will require a temporary stream diversion. A sandbag berm will need to
be installed 5m upstream from the proposed works. When the berm is installed a pump should be
used to pump water around the proposed works. A sandbag berm should then be installed
downstream of the proposed works. The water between the berms should then be pumped out.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 25
7.3 Access Requirements
Access to the majority of the pump station, CSO and WWTP sites should be fairly straight forward.
Some thought will need to be applied to the access road for GB-LS1. The ROW for Wallace Road
does extend near the site so an access road could be extended from the intersection of Wallace
Road and Khalsa Drive. The access road would be approximately 100m in length.
7.4 Power Supply Requirements
Three phase power will be required for each of the pump station sites. Three phase power will need
to be extended to each of the pump station sites. Find below a table indicating the length of
extension required and the originating location for the closest three phase power source for each
station.
Table 7-1 Power Supply Details
Station Required Extension
Length (m)Originating Location
LS-GB1 550 Intersection of Cooling Street & West Avenue
LS-GB2 180 Intersection of Cooling Street & West Avenue
LS-GB3 300 Sterling Road
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 26
CHAPTER 8 OPINION OF PROBABLE COSTS
8.1 Opinion of Probable Costs – New Wastewater Collection Infrastructure
An opinion of Probable Design and Construction Costs for the proposed wastewater collection
system infrastructure has been completed for the project. A detailed breakdown of the estimate has
been provided in Appendix C. The estimate is made up of the linear infrastructure design and
construction costs and associated land acquisition costs, CSO Chambers and pump stations required
to collect and convey the sanitary sewer in Glace Bay to the proposed WWTP. For land acquisition
costs, HEJV has used a ratio of the amount of land that is affected by the required
easement/property acquisition multiplied by the assessed value of the entire lot. The Opinion of
Probable Design and Construction Costs for the interceptor sewer for Glace Bay is $9,610,875. This
estimate is considered to be Class ‘C’, accurate to within plus or minus 30%.
8.2 Opinion of Operational Costs
HEJV completed an Opinion of Operational Costs for the interceptor system using data provided by
CBRM for typical annual operating costs of their existing submersible pump stations, typical
employee salaries, Nova Scotia Power rates, and experience from similar stations for general
maintenance. The opinion of operational costing includes the initial capital costs as detailed in
Section 8.1 in combination with general pump station maintenance costs, general linear
maintenance costs, employee operation and maintenance costs, electrical operational costs and
backup generator operation and maintenance costs. A breakdown of costs has provided in Table 8-
1.
Table 8-1 Annual Operations and Maintenance Costs
The general station maintenance cost presented above includes pump repairs (impellers, bearings,
seals), minor building maintenance (painting, siding repairs, roof repairs), electrical repairs and
instrumentation repairs and servicing.
Item Cost
General Pump Station Maintenance Cost $15,500/yr
General Linear Maintenance Cost $1,000/yr
Employee O&M Cost $14,500/yr
Electrical Operational Cost $52,000/yr
Backup Generator O&M Cost $9,500/yr
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 27
The general linear maintenance cost for the interceptor system has been estimated to be $1000 per
year in 2018 dollars. This includes flushing, inspection, and refurbishment of structures along the
linear portion of the collection system.
Employee O&M costs were averaged from data provided by CBRM. It was determined that staffing
to maintain their existing pump stations requires an average of 100 hours of effort per submersible
pump station per year.
For the electrical operation cost, HEJV assumed the building would require heat for 5 months of the
year. Basic electrical loads for instrumentation were assumed. Electrical demand from the pumping
system was determined based on the yearly average flow of the station.
Backup generator operation and maintenance costs assumed that a diesel backup generator would
be utilized. The costs include an annual diesel fuel cost assuming that the generator is run for one
hour each month, as well as annual maintenance for the generator (change of filters and oil,
inspection of the generator, and load bank testing).
8.3 Opinion of Existing Collection System Upgrades and Assessment Costs
Opinions of probable cost have been provided to complete the work that was discussed in Chapter
4. For sewerage pumping stations, the opinion of probable cost includes a full retrofit of each of the
existing stations noted in Chapter 4 including new pumps, controls and backup power generation.
The need to upgrade these stations should be verified at detailed design, as discussed in Chapter 4.
In addition, HEJV has also allowed for two additional backup generators for the Brookside Street and
South Street stations. These stations were upgraded in 2015, without the inclusion of backup power
generation. Lift station upgrade costs are presented in Table 8-2. HEJV has provided an allowance
of 12% on the cost of construction for engineering and 25% for contingency allowance.
An opinion of probable costs has been provided for the collection system asset condition
assessment program described in Chapter 4. These costs include the video inspection and flushing of
20% of the existing sanitary sewer network, visual inspection of manholes, traffic control and the
preparation of a collection system asset condition assessment report.
For sewer separation measures, budgetary pricing has been calculated by reviewing recent costs of
sewer separation measures in CBRM involving installation of new storm sewers to remove
extraneous flow from existing sanitary sewers. These costs have been translated into a cost per
lineal meter of sewer main. This unit rate was then applied to the overall collection system. The cost
also includes an allowance of 10% on the cost of construction for engineering and 25% for
contingency allowance.
The opinion of probable cost in Table 8-2 for CSO Station outfall upgrades provides an allowance to
connect to an existing outfall with a manhole structure and provide an extension of the outfall pipe
into the marine environment. HEJV has provided an allowance of 12% on the cost of construction for
engineering and 25% for contingency allowance.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 28
Estimates of costs for upgrades to and assessment of the existing collection system as outlined in
Table 8-2 are considered to be Class ‘D’, accurate to within plus or minus 45%.
Table 8-2 Estimated Existing Collection System Upgrade and Assessment Costs
8.4 Opinion of Annual Capital Replacement Fund Contributions
The CBRM wishes to create a Capital Replacement Fund to which annual contributions would be
made to prepare for replacement of the assets at the end of their useful life. The calculation of
annual contributions to this fund involves consideration of such factors as the type of asset, the
asset value, the expected useful life of the asset, and the corresponding annual depreciation rate for
the asset. In consideration of these factors,Table 8-3 provides an estimation of the annual
contributions to a capital replacement fund for the proposed new wastewater collection and
interception infrastructure.
Item Cost
Sewage Pump Station Upgrades (for 2 stations)
Pump Station Infrastructure (controls, pumps, etc.)$652,000
Backup Power Generation (required for 4 stations)$233,000
Engineering (12%)$106,000
Contingency (25%)$222,000
Total $1,213,000
Collection System Asset Condition Assessment Program
Condition Assessment of Manholes based on 1482 MH’s $275,000
Condition Assessment of Sewer Mains based on 25.2km’s of infrastructure $260,000
Total $535,000
Sewer Separation Measures
Separation based on 126km’s of sewer @ $45,000/km $5,670,000
Engineering (10%)$567,000
Contingency (25%)$1,418,000
Total $7,655,000
CSO Station Outfall Upgrades (for 5 existing outfalls)
Extension incl. drop manhole ($248,000 per connection)
Engineering (12%)
Contingency (25%)
$1,240,000
$149,000
$310,000
Total $1,699,000
Total Estimated Existing Collection System Upgrade and Assessment Costs $11,102,000
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 29
Table 8-3 Estimated Annual Capital Replacement Fund Contributions
Description of Asset Asset Value
Asset Useful
Life
Expectancy
(Years)
Annual
Depreciation
Rate (%)
Annual Capital
Replacement
Fund Contribution
Linear Assets (Piping, Manholes and Other) $4,858,475 75 1.3%$63,160
Pump Station Structures (Concrete
Chambers, etc.)$1,158,190 50 2.0%$23,164
Pump Station Equipment (Mechanical /
Electrical)$947,610 20 5.0%$47,381
Subtotal $6,964,275 --$133,704
Contingency Allowance (Subtotal x 25%):$33,426
Engineering (Subtotal x 10%):$13,370
Opinion of Probable Annual Capital Replacement Fund Contribution:$180,500
Note:
Annual contribuƟons do not account for annual inflaƟon.
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 30
CHAPTER 9 REFERENCES
Environment Canada (2006) –Atlantic Canada Wastewater Gidelines Manual for Collection,
Treatment and Disposal.
Harbour Engineering Inc. (2011).Cape Breton Regional Municipality Wastewater Strategy 2009.
Nova Scotia Environment (2018).Environment Act.
Nova Scotia Utility and Review Board (2013).Water Utility Accounting and Reporting Handbook.
UMA Engineering Ltd. (1994). Industrial Cape Breton Wastewater Characterization Programme –
Phase II.
Water Environment Federation (2009),Design of Wastewater and Stormwater Pumping Stations
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 31
APPENDIX A
Drawings
LS-GB1
15441355
(HER MAJESTY THE QUEEN & PWGSC)
15441090
(HER MAJESTY THE QUEEN & PWGSC)
15437791
(HER MAJESTY THE
15437742
(HER MAJESTY THE QUEEN & PWGSC)
15437718
(CBRM)
CSO-1
QUEEN & PWGSC)
15440969
(NEW ABERDEEN GARDEN TOWNHOUSES INC.)
15440936
(YOUTH FOR CHRIST CANADA)
15526668
(HER MAJESTY THE QUEEN & PWGSC)
450mmØ
200mmØ
150mmØ
EXISTING OUTFALL (GB1)
GB2
GB3
GB4
GB5
450mmØ
250mmØ
100m
m
Ø
20
0
m
m
Ø
COO
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1
ENVIRONMENTAL RISK ASSESSMENTS
& PRELIMINARY DESIGN
TGB
TGB TAB
JRS 18-7116
1:2500
MARCH 2019
HA
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ISSUED FOR DRAFT BRIEF
ISSUED FOR FINAL BRIEF
02/27/18
03/22/19
JRS
JRS
WALLACE Rd. CONNECTION to FIRST St. LIFT STATION
DATE
DESIGN
DRAWN
PROJECT NO.
SHEET NO.
No.DATE BYISSUED FOR
written permission from Dillon Consulting Limited.
than those intended at the time of its preparation without prior
Do not scale dimensions from drawing.
Report any discrepancies to Dillon Consulting Limited.
Verify elevations and/or dimensions on drawing prior to use.
Conditions of Use
REVIEWED BY
CHECKED BY
Do not modify drawing, re-use it, or use it for purposes other
SCALEj o i n t v e n t u r e
PLAN
1:2500
PROFILE
1:2500 (HOR.) 1:500 (VERT.)
15431122
(ANNIE LORRAINE MC DONALD)
15739113
(ROAD PARCEL OWNER UNDETERMINED)
FI
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15437718
(CBRM)
TIM
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15531023
(HER MAJESTY THE QUEEN and
PUBLIC WORKS GOVERN SERVICES CANADA)
15531064
(HER MAJESTY THE QUEEN and
PUBLIC WORKS GOVERN SERVICES CANADA)
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ENVIRONMENTAL RISK ASSESSMENTS
& PRELIMINARY DESIGN
TGB
TGB TAB
JRS 18-7116
1:2500
MARCH 2019
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ISSUED FOR DRAFT BRIEF
ISSUED FOR FINAL BRIEF
02/27/18
03/20/19
JRS
JRS
FIRST St. LIFT STATION
to
UPPER NORTH St. LIFT STATION
DATE
DESIGN
DRAWN
PROJECT NO.
SHEET NO.
No.DATE BYISSUED FOR
written permission from Dillon Consulting Limited.
than those intended at the time of its preparation without prior
Do not scale dimensions from drawing.
Report any discrepancies to Dillon Consulting Limited.
Verify elevations and/or dimensions on drawing prior to use.
Conditions of Use
REVIEWED BY
CHECKED BY
Do not modify drawing, re-use it, or use it for purposes other
SCALEj o i n t v e n t u r e
PLAN
1:2500
PROFILE
1:2500 (HOR.) 1:500 (VERT.)
UPPER NORTH ST
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15393721
(CBRM)
15821127
(OWNER UNKNOWN)
15524481
(CBRM)
15654882
(GLACE BAY MINERS FORUM CO LTD
CBRM)
15864085
(CBRM)
15408867
(HOPKINS H LTD)
300mmØ
15850555
(CAMERON'S BUILDING SUPPLIES LTD)
15524473
(PUBLIC WORKS AND
15821119
(CHARLES H RIGBY)
LS-GB3
WWTP SITE
proposed
outfall
GOVERNMENT SERVICES CANADA)
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ENVIRONMENTAL RISK ASSESSMENTS
& PRELIMINARY DESIGN
TGB
TGB JRS
JRS 18-7116
1:2500
MARCH 2019
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ISSUED FOR DRAFT BRIEF
ISSUED FOR FINAL BRIEF
RE-ISSUED FOR FINAL BRIEF
02/27/18
03/20/19
06/30/20
JRS
JRS
JRS UPPER NORTH St. LIFT STATION to WWTP and Bell St.
DATE
DESIGN
DRAWN
PROJECT NO.
SHEET NO.
No.DATE BYISSUED FOR
written permission from Dillon Consulting Limited.
than those intended at the time of its preparation without prior
Do not scale dimensions from drawing.
Report any discrepancies to Dillon Consulting Limited.
Verify elevations and/or dimensions on drawing prior to use.
Conditions of Use
REVIEWED BY
CHECKED BY
Do not modify drawing, re-use it, or use it for purposes other
SCALEj o i n t v e n t u r e
PLAN
1:2500
PROFILE
1:2500 (HOR.) 1:500 (VERT.)
1
6
___
1
6
___
FLUSH MOUNT ALUMINUM
HATCH C/W SAFETY GATE.
CLEAR OPENING 900x1500
100Ø VENT AND 150Ø CAP
FLOW METER ON
VERTICAL (TYP.)
AIR RELEASE VALVE (TYP.)
WATER SERVICE
CHECK VALVE ANDPLUG VALVE ON VERTICAL (TYP.2)
CONCRETE SLAB
DAVITSOCKET
ELECTRICAL ROOMPROCESS ROOM
GENERATOR ROOM
DIESEL GENERATOR SET
EXHAUST LOUVER
INTAKE LOUVER
7661
281421692679
4267
800800
550
450
j o i n t v e n t u r e
DATE
DESIGN
DRAWN
PROJECT NO.
SHEET NO.
No.DATE BYISSUED FOR
written permission from Dillon Consulting Limited.
than those intended at the time of its preparation without prior
Do not scale dimensions from drawing.
Report any discrepancies to Dillon Consulting Limited.Verify elevations and/or dimensions on drawing prior to use.
Conditions of Use
REVIEWED BY
CHECKED BY
Do not modify drawing, re-use it, or use it for purposes other
SCALE
FILENAME:
C:\PROJECTWISE\WORKING
DIRECTORY\PROJECTS
2018\54MSR\DMS30805\PORT
MORIEN
PUMP
STATION
DRAWING
BLOCK.DWG
PLOTTED
BY:
RODGERS,
MATTHEW
PLOT
DATE:
2018-06-25
@
2:41:31
PM
PLOT
SCALE:
1:2.585
PLOT
STYLE:
CANRAIL
-
MARY
RIVER.CTB
NTSAISSUED FOR DRAFT DESIGN BRIEF 03/11/19 JRS
18-7116OF 7 FUTURE WASTEWATER TREATMENT SYSTEMS IN CBRM
ENVIRONMENTAL RISK ASSESSMENTS & PRELIMINARY DESIGN
MARCH 2019
MSR ASW
4
ASW MAB
PLAN
GLACE BAY DUPLEX LIFT STATIONS
SCALE:SCALE: NTS
WET WELL - ABOVE GRADE
SCALE:SCALE:
MODEL VIEW I
TOP OF CONCRETE
FLOW METER
SWING CHECK VALVE (TYP.2)
PLUG VALVE (TYP.3)
FORCEMAIN
AIR RELEASE VALVE (TYP.)
SS PIPE FROM PUMPS
300
1505
730
ELEV. =
FIN FLOOR
6.500 m
ELEV. =
TOP OF WALL
9.200 m
FLUSH MOUNT ALUMINUM
HATCH C/W SAFETY GATE.
CLEAR OPENING 900x1500
PVC INLET PIPE
INLET BAFFLE
FORCEMAIN
100Ø VENT AND 150Ø VENT CAP
j o i n t v e n t u r e
DATE
DESIGN
DRAWN
PROJECT NO.
SHEET NO.
No.DATE BYISSUED FOR
written permission from Dillon Consulting Limited.
than those intended at the time of its preparation without prior
Do not scale dimensions from drawing.
Report any discrepancies to Dillon Consulting Limited.Verify elevations and/or dimensions on drawing prior to use.
Conditions of Use
REVIEWED BY
CHECKED BY
Do not modify drawing, re-use it, or use it for purposes other
SCALE
FILENAME:
C:\PROJECTWISE\WORKING
DIRECTORY\PROJECTS
2018\54MSR\DMS30805\PORT
MORIEN
PUMP
STATION
DRAWING
BLOCK.DWG
PLOTTED
BY:
RODGERS,
MATTHEW
PLOT
DATE:
2018-06-25
@
2:41:31
PM
PLOT
SCALE:
1:2.585
PLOT
STYLE:
CANRAIL
-
MARY
RIVER.CTB
NTSAISSUED FOR DRAFT DESIGN BRIEF 03/11/19 JRS
18-7116OF 7 FUTURE WASTEWATER TREATMENT SYSTEMS IN CBRM
ENVIRONMENTAL RISK ASSESSMENTS & PRELIMINARY DESIGN
MARCH 2019
MSR ASW
5
ASW MAB
SECTIONS
GLACE BAY DUPLEX LIFT STATIONS
SCALE:SCALE: NTS
SECTION 1
SCALE:SCALE: NTS
WET WELL - BELOW GRADE
250Ø PLUG
VALVE (TYP.)
250Ø FLOW METER (TYP.)
250Ø CHECK VALVE (TYP)
1
7
___
1
7
___
2
7
___2
7
___
ELECTRICAL ROOM
250Ø PLUG VALVE (TYP)
AIR RELEASE VALVE TO BE
VENTED TO WET WELL (TYP)
FORCEMAIN
1250
250Ø PROCESS PIPING
250Ø 90 DEGREE BEND
250Ø PROCESS PIPING250Øx250Øx250Ø TEE (TYP.)
500
GENERATOR ROOM
7733
2121
2705
2907
7980
54472536
2900
1
7
___
1
7
___
WET WELL FOOTING
150Ø VENT AND 200Ø CAP
INLET BAFFLE
SEWER INLET
2400
3600
FLUSH MOUNT ALUMINUM
HATCH C/W WITH SAFETY GRATE
SCALE:SCALE: 1 : 25
PLAN
SCALE:SCALE:
3D MODEL
j o i n t v e n t u r e
DATE
DESIGN
DRAWN
PROJECT NO.
SHEET NO.
No.DATE BYISSUED FOR
written permission from Dillon Consulting Limited.
than those intended at the time of its preparation without prior
Do not scale dimensions from drawing.
Report any discrepancies to Dillon Consulting Limited.Verify elevations and/or dimensions on drawing prior to use.
Conditions of Use
REVIEWED BY
CHECKED BY
Do not modify drawing, re-use it, or use it for purposes other
SCALE
FILENAME:
C:\PROJECTWISE\WORKING
DIRECTORY\PROJECTS
2018\54MSR\DMS30805\PORT
MORIEN
PUMP
STATION
DRAWING
BLOCK.DWG
PLOTTED
BY:
RODGERS,
MATTHEW
PLOT
DATE:
2018-06-25
@
2:41:31
PM
PLOT
SCALE:
1:2.585
PLOT
STYLE:
CANRAIL
-
MARY
RIVER.CTB
A ISSUED FOR DRAFT DESIGN BRIEF 03/15/19 JRS 1 : 25
18-7116OF 7 FUTURE WASTEWATER TREATMENT SYSTEMS IN CBRM
ENVIRONMENTAL RISK ASSESSMENTS & PRELIMINARY DESIGN
MARCH 2019
MSR ASW
6
ASW MAB
PLAN
GLACE BAY LS #3
SCALE:SCALE: 1 : 25
WET WELL PLAN
250Ø PIPE
PUMP GUIDE BARS (TYP.)
DISCHARGE PIPE SUPPORTS (TYP.)
FORCEMAIN
250Ø PLUG VALVE
(TYP.)
250Ø FLOW
METER (TYP.)
250Ø PLUG
VALVE (TYP.3)
AIR RELEASE
VALVE (TYP.3)
PUMP LIFTING CHAIN TO EXTEND
AND ATTACH TO CHAMBER LID (TYP.3)
WET WELL BENCHING
CONCRETE
MUD SLABCLEAR STONE
BEDDING
(TYP.)
PRESSURE
TRANSDUCER (TYP.)
MULTITRODE LIQUID
LEVEL SENSOR (TYP.)TIE DOWN ANCHOR SYSTEM TO RESIST
BUOYANT UPLIFT PRESSURE.
PRECAST CONCRETE BASE, RISERS
AND COVER (TYP.)
LIQUID LEVEL SENSOR
SUPPORT BRACKET
(TYP.)
HORIZONTAL LEVEL
REGULATOR HANGER
BASE SLAB TO EXTEND
DI PVC
TRANSITION COUPLING
AT 1m OUTSIDE
FOUNDATION (TYP.)
250Ø CHECK
VALVE (TYP3.)
250Ø
AIR RELEASE
VALVE
FIXED FLANGED "SPOOL" PIECE (TYP.)
INLET BAFFLE.
SEE PLAN
INLET
250Ø CHECK VALVE AND
250Ø PLUG VALVE ON
HORIZONTAL. (TYP.3)
SEE PLAN.
250Ø PIPE (TYP.)
PRECAST CONCRETE BASE,
RISERS AND COVER (TYP.)
PUMP (TYP.)
WET WELL BENCHING
NOTE: BAFFLE WALL
NOT SHOWN FOR
CLARITY. SEE PLAN.
AIR RELEASE
VALVE (TYP.)
j o i n t v e n t u r e
DATE
DESIGN
DRAWN
PROJECT NO.
SHEET NO.
No.DATE BYISSUED FOR
written permission from Dillon Consulting Limited.
than those intended at the time of its preparation without prior
Do not scale dimensions from drawing.
Report any discrepancies to Dillon Consulting Limited.Verify elevations and/or dimensions on drawing prior to use.
Conditions of Use
REVIEWED BY
CHECKED BY
Do not modify drawing, re-use it, or use it for purposes other
SCALE
FILENAME:
C:\PROJECTWISE\WORKING
DIRECTORY\PROJECTS
2018\54MSR\DMS30805\PORT
MORIEN
PUMP
STATION
DRAWING
BLOCK.DWG
PLOTTED
BY:
RODGERS,
MATTHEW
PLOT
DATE:
2018-06-25
@
2:41:31
PM
PLOT
SCALE:
1:2.585
PLOT
STYLE:
CANRAIL
-
MARY
RIVER.CTB
A ISSUED FOR DRAFT DESIGN BRIEF 03/15/19 JRS 1 : 25
18-7116OF 7 FUTURE WASTEWATER TREATMENT SYSTEMS IN CBRM
ENVIRONMENTAL RISK ASSESSMENTS & PRELIMINARY DESIGN
MARCH 2019
MSR ASW
7
ASW MAB
SECTIONS
GLACE BAY LS #3
SCALE:SCALE: 1 : 25
SECTION 1
SCALE:SCALE: 1 : 25
SECTION 2
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 32
APPENDIX B
Flow Master Reports
Harbour Engineering Joint Venture Glace Bay Collection System Pre-Design Brief 33
APPENDIX C
Opinion of Probable Design & Construction
Costs
OPINION OF PROBABLE
COST, CLASS 'C'
Preliminary Collection Project Manager:D. McLean
and Interception Infrastructure Costs Only Est. by: J. Sheppard Checked by: D.McLean
Glace Bay, NS PROJECT No.:187116 (Dillon)
182402.00 (CBCL)
UPDATED:June 30, 2020
NUMBER UNIT
Linear Infrastructure $3,958,475.00
200 mm Diameter PVC gravity sewer 650 m $320.00 $208,000.00
250 mm Diameter PVC gravity sewer 200 m $330.00 $66,000.00
300 mm Diameter PVC gravity sewer 30 m $340.00 $10,200.00
375 mm Diameter PVC gravity sewer 70 m $360.00 $25,200.00
450 mm Diameter PVC gravity sewer 1,340 m $410.00 $549,400.00
450 mm Diameter PVC gravity sewer (Deep Installation)510 m $600.00 $306,000.00
1200 mm Diameter PVC gravity sewer (Deep Installation)150 m $1,000.00 $150,000.00
100 mm Diameter PVC forcemain 465 m $250.00 $116,250.00
150 mm Diameter PVC forcemain 265 m $285.00 $75,525.00
250 mm Diameter PVC forcemain 1,250 m $320.00 $400,000.00
Outfall 325 m $3,600.00 $1,170,000.00
Air Release Chamber 2 each $13,500.00 $27,000.00
Blow Off Connection 1 each $7,500.00 $7,500.00
Precast Manhole (1200mm dia.)36 each $5,500.00 $198,000.00
Precast Manhole (3000mm dia)3 each $45,000.00 $135,000.00
Connection to Existing Main (typ)13 each $8,000.00 $104,000.00
Connection to Existing Main (with 3000mm MH)1 each $100,000.00 $100,000.00
Closed Circuit Televsion Inspection 2,800 m $8.00 $22,400.00
Trench Excavation - Rock 3,200 m3 $60.00 $192,000.00
Trench Excavation - Unsuitable Material 3,200 m3 $10.00 $32,000.00
Replacement of Unsuitable with Site Material 1,600 m3 $10.00 $16,000.00
Replacement of Unsuitable with Pit Run Gravel 1,600 m3 $30.00 $48,000.00
Wallace Road Lift Station $586,800.00
Pump Station 1 L.S.$500,000.00 $500,000.00
Site Work 1 L.S.$85,000.00 $85,000.00
Mass Excavation - Rock 20 m3 $60.00 $1,200.00
MassExcavation - Unsuitable Material 20 m3 $10.00 $200.00
Replacement of Unsuitable with Site Material 10 m3 $10.00 $100.00
Replacement of Unsuitable with Pit Run Gravel 10 m3 $30.00 $300.00
West Ave. Lift Station $564,500.00
Pump Station 1 L.S.$500,000.00 $500,000.00
Site Work 1 L.S.$60,000.00 $60,000.00
Mass Excavation - Rock 50 m3 $60.00 $3,000.00
MassExcavation - Unsuitable Material 50 m3 $10.00 $500.00
Replacement of Unsuitable with Site Material 25 m3 $10.00 $250.00
Replacement of Unsuitable with Pit Run Gravel 25 m3 $30.00 $750.00
Upper North Street Lift Station $954,500.00
Pump Station 1 L.S.$900,000.00 $900,000.00
Site Work 1 L.S.$50,000.00 $50,000.00
Mass Excavation - Rock 50 m3 $60.00 $3,000.00
MassExcavation - Unsuitable Material 50 m3 $10.00 $500.00
Replacement of Unsuitable with Site Material 25 m3 $10.00 $250.00
Replacement of Unsuitable with Pit Run Gravel 25 m3 $30.00 $750.00
Combined Sewer Overflow $900,000.00
Combined Sewer Overflow (CS0-1 to CSO-5)5 L.S.$100,000.00 $500,000.00
Combined Sewer Overflow (CSO-6)1 L.S.$400,000.00 $400,000.00
SUBTOTAL (Construction Cost)$6,964,275.00
Contingency Allowance (Subtotal x 25 %)$1,742,000.00
Engineering (Subtotal x 10 %)$697,000.00
Land Acquisition $207,600.00
OPINION OF PROBABLE COST (Including Contingency)$9,610,875.00
THIS OPINION OF PROBABLE COSTS IS PRESENTED ON THE BASIS OF EXPERIENCE, QUALIFICATIONS, AND BEST JUDGEMENT. IT HAS BEEN PREPARED IN
ACCORDANCE WITH ACCEPTABLE PRINCIPLES AND PRACTICIES, MARKET TRENDS, NON-COMPETITIVE BIDDING SITUATIONS, UNFORSEEN LABOUR AND
MATERIAL ADJUSTMENTS AND THE LIKE ARE BEYOND THE CONTROL OF HEJV. AS SUCH WE CANNOT WARRANT OR GUARANTEE THAT ACTUAL COSTS
WILL NOT VARY FROM THE OPINION PROVIDED.
EXTENDED TOTALS QUANTITY TOTALUNIT COSTITEM DESCRIPTION
PREPARED FOR:
Cape Breton
Regional Municipality
March 27, 2020
HEJV Glace Bay Wastewater System Pre‐Design Summary Report Appendices
APPENDIX B
Glace Bay Treatment System
Pre‐Design Brief
182402.00 ● Final Brief ● June 2020
Environmental Risk Assessments & Preliminary
Design of Seven Future Wastewater Treatment
Systems in CBRM
Glace Bay Wastewater Treatment Plant
Preliminary Design Brief
Prepared by:
Prepared for:
March 2020
Glace Bay WW Treatment System
Preliminary Design Brief – Final
June 30, 2020 Darrin McLean Mike Abbott
Dave McKenna
Holly Sampson
Glace Bay WW Treatment System
Preliminary Design Brief – Revision 1
April 16, 2020 Darrin McLean Mike Abbott
Dave McKenna
Holly Sampson
Glace Bay WW Treatment System
Preliminary Design Brief
January 29, 2019 Darrin McLean Mike Abbott
Dave McKenna
Holly Sampson
Issue or Revision Date Issued By: Reviewed By: Prepared By:
This document was prepared for the party indicated
herein. The material and information in the
document reflects HE’s opinion and best judgment
based on the information available at the time of
preparation. Any use of this document or reliance
on its content by third parties is the responsibility of
the third party. HE accepts no responsibility for any
damages suffered as a result of third party use of
this document.
182402.00
March 27, 2020
182402.00 PRELIMINARY DESIGN GLACE BAY_JUNE30/mk
ED: 30/06/2020 14:24:00/PD: 30/06/2020 14:26:00
275 Charlotte Street
Sydney, Nova Scotia
Canada B1P 1C6
Tel: 902‐562‐9880
Fax: 902‐562‐9890
June 30, 2020
Matt Viva, P.Eng.
Manager Wastewater Operations
Cape Breton Regional Municipality (CBRM)
320 Esplanade,
Sydney, NS B1P 7B9
Dear Mr. Viva:
RE: Glace Bay Wastewater Treatment Plant Preliminary Design – Final
Enclosed, please find a copy of the Draft Preliminary Design Brief – Final for the
Glace Bay Wastewater Treatment Plant (WWTP).
The report presents an evaluation of four treatment process alternatives for the
Glace Bay WWTP. It also presents a preliminary design based on the
recommended SBR treatment process.
If you have any questions or require clarification on the content presented in
the attached report, please do not hesitate to contact us.
Yours very truly,
Harbour Engineering Joint Venture
Prepared by: Reviewed by:
Holly Sampson, M.A.Sc., P.Eng. Mike Abbott, P.Eng., M.Eng.
Intermediate Chemical Engineer Manager Process Department
Direct: 902‐539‐1330
E‐Mail: hsampson@cbcl.ca
Reviewed by:
Dave McKenna, P.Eng., M.Eng.
Associate/Technical Service Lead
Project No: 182402.00 (CBCL)
187116.00 (Dillon)
March 27, 2020
HEJV Glace Bay WWTP Preliminary Design Brief i
Contents
CHAPTER 1 Introduction .......................................................................................................... 1
1.1 Introduction .................................................................................................................. 1
1.2 Background ................................................................................................................... 1
1.3 Objectives ..................................................................................................................... 1
Chapter 2 Existing Conditions ................................................................................................ 2
2.1 Description of Existing Infrastructure ........................................................................... 2
2.2 Wastewater Flow Characteristics ................................................................................. 2
2.2.1 Dry Weather Flows ........................................................................................... 3
2.2.3 Average Flows ................................................................................................... 4
2.2.2 Peak Day Flows ................................................................................................. 6
2.2.3 Extraneous Flow Reduction .............................................................................. 6
2.3 Wastewater Quality Characteristics ............................................................................. 6
2.4 Wastewater Loading Analysis ....................................................................................... 7
Chapter 3 Basis of Design ...................................................................................................... 9
3.1 Service Area Population ................................................................................................ 9
3.2 Design Flows and Loads ................................................................................................ 9
3.3 Effluent Requirements ................................................................................................ 13
3.4 Summary ..................................................................................................................... 13
Chapter 4 Treatment Process Alternatives ........................................................................... 15
4.1 Preliminary Treatment ................................................................................................ 15
4.1.1 Screening ........................................................................................................ 15
4.1.2 Grit Removal ................................................................................................... 16
4.2 Secondary Treatment ................................................................................................. 16
4.2.1 Site‐specific Suitability .................................................................................... 17
4.2.2 Description of Candidate Processes for Secondary Treatment ...................... 19
4.3 Disinfection ................................................................................................................. 25
4.3.1 CAS, MBBR or MBR Effluent Disinfection ....................................................... 25
4.3.2 SBR Effluent Disinfection ................................................................................ 26
4.4 Sludge Management ................................................................................................... 26
4.5 Secondary Treatment Option Evaluation ................................................................... 26
4.5.1 Capital Cost Estimate ...................................................................................... 26
HEJV Glace Bay WWTP Preliminary Design Brief ii
4.5.2 Operating and Lifecycle Cost Estimate ........................................................... 27
4.5.3 Qualitative Evaluation Factors ........................................................................ 28
4.5.4 Recommended Secondary Treatment Process ............................................... 29
Chapter 5 Preliminary Design .............................................................................................. 30
5.1 Process Description ..................................................................................................... 30
5.2 Unit Process Descriptions ........................................................................................... 30
5.2.1 Preliminary Treatment .................................................................................... 30
5.2.2 Secondary Treatment ..................................................................................... 31
5.2.3 Disinfection ..................................................................................................... 32
5.2.4 Sludge Management ....................................................................................... 33
5.3 Facilities Description ................................................................................................... 33
5.3.1 Civil and Site Work .......................................................................................... 34
5.3.2 Architectural ................................................................................................... 34
5.3.3 Mechanical ...................................................................................................... 35
5.3.4 Electrical .......................................................................................................... 35
5.3.5 Lighting ........................................................................................................... 35
5.3.6 Instrumentation .............................................................................................. 35
Chapter 6 Project Costs ....................................................................................................... 38
6.1 Opinion of Probable Capital Costs .............................................................................. 38
6.2 Opinion of Annual Operating Costs ............................................................................ 38
6.3 Opinion of Annual Capital Replacement Fund Contributions ..................................... 38
Appendices
A Flow Meter Data
B Environmental Risk Assessment
C Preliminary Design Drawings
HEJV Glace Bay WWTP Preliminary Design Brief 1
CHAPTER 1 INTRODUCTION
1.1 Introduction
Harbour Engineering Joint Venture (HEJV) was retained by the Cape Breton Regional Municipality
(CBRM) to provide engineering services associated with the preliminary design of a wastewater
treatment plant (WWTP) for the community of Glace Bay, Nova Scotia as part of the greater
Environmental Risk Assessment and Preliminary Design of 7 Future Wastewater Treatment Systems
in CBRM project. This report will present preliminary design options for the proposed WWTP, as
well as a detailed discussion of the processes involved and their associated costs.
1.2 Background
The wastewater collection system in the community of Glace Bay (GB), as in many communities
throughout CBRM, currently discharges untreated wastewater to the Atlantic Ocean. The evolution
of the existing wastewater collection and disposal systems in CBRM included the creation of clusters
/ neighbourhoods / regions of a community which were serviced by a common wastewater
collection system tied to a local marine outfall. Such design approaches have traditionally been the
most cost‐effective manner of providing centralized wastewater collection, and the marine
environment has long been the preferred receiving water given the available dilution. Due to a
changing regulatory environment, CBRM is working toward intercepting and treating the
wastewater in these communities prior to discharge.
1.3 Objectives
The objectives of this report will be to:
Establish design parameters for a new WWTP;
Evaluate treatment process alternatives; and
Present a preliminary engineering design, with capital and operating cost estimates, for a
new WWTP to meet the design requirements.
HEJV Glace Bay WWTP Preliminary Design Brief 2
CHAPTER 2 EXISTING CONDITIONS
2.1 Description of Existing Infrastructure
The Glace Bay wastewater collection system includes a significant portion of the footprint of the former
Town of Glace Bay and the community of Reserve Mines. The remainder of the Glace Bay area flows to
the Dominion system. The system consists of approximately 118km of gravity sewer and 3.1km of force
main. It also includes six lift stations at the following locations:
Brookside Street;
Lake Road;
South Street;
Reserve Street;
McLeods Road; and
Railway Street.
The majority of the wastewater is already directed to the main outfall at Glace Bay Harbour, with the
remainder being discharged through eight additional outfalls along the coast to the north of the main
outfall. The outfalls are located at or near the following locations:
Glace Bay Harbour (main outfall);
Wallace Road;
Shea’s Lane;
Centre Avenue;
East Avenue (2);
Second Street; and
Upper North Street (2).
2.2 Wastewater Flow Characteristics
Flow meters were installed in various portions of the sewer system in fall of 2017, winter/spring of 2018
and/or summer of 2018 with results summarized in this section. Data was collected from four
flowmeters installed in fall of 2017 as part of a different project. Three flowmeters were installed in
spring 2018 to collect flow data from additional areas of the collection system. Flow meters were
subsequently re‐installed at two of these locations in summer of 2018 to determine whether the high
flows observed during the spring metering program were seasonally influenced. Flow meter data is
plotted on a series of Figures in Appendix A. The dates of flow data collection at each location are
summarized in Table 2.1.
HEJV Glace Bay WWTP Preliminary Design Brief 3
Table 2.1 Flow Meter Installation Summary
Meter Dates
Park Street March 6 ‐ April 30, 2018
August 7 ‐ September 5, 2018
May Street February 15 ‐ May 8, 2018
July 27 ‐ August 7, 2018
Main Street February 15 ‐ May 8, 2018
GB2 November 23 ‐ December 21, 2017
GB6 November 29, 2017 ‐ January 4, 2018
GB7 November 30, 2017 ‐ January 4, 2018
Luke Street October 19 ‐ November 21, 2017
2.2.1 Dry Weather Flows
The average dry weather flow (ADWF) results for each of the meter locations and meter periods is
summarized in Table 2.2. The average dry weather flow was defined as the average flow for the days
that met the following criteria:
No rain within the last 24 hours (greater than 1mm); and
No more than 5 mm in the previous 48 hours.
Table 2.2 Flow Meter Data Summary – Average Dry Weather Flows
Meter Area (ha) Population ADWF (m3/day) ADWF (L/p/d)
Fall Spring Summer Fall Spring Summer
Park Street 127 1893 ‐ 4412 1734 ‐ 2331 916
May Street 245 2790 ‐ 5683 3087 ‐ 2037 1106
Main Street 113 1868 ‐ 1924 ‐ ‐ 1030 ‐
GB2 39 504 542 ‐ ‐ 1075 ‐ ‐
GB6 46 713 508 ‐ ‐ 712 ‐ ‐
GB7 14 140 164 ‐ ‐ 1171 ‐ ‐
Luke 81 1268 762 ‐ ‐ 601 ‐ ‐
Metered Total 665 9,176
Serviced Total 1033 14,536
Flow data collected during the spring of the year was considerably higher than data collected during the
remainder of the year. Even during periods of no rain, it is clear that extraneous flow due to high
groundwater conditions results in flow conditions that are not representative of dry weather flow. It
was also found that surface water was entering the sewer system upstream of the Park Street meter in a
location where the sewer crossed Renwick Brook.
If the spring data for Park Street and May Street was omitted as not being representative of dry weather
conditions, the average dry weather flow for the metered catchment areas is 8,721 m3/day for 9,176
people and 665 ha (Table 2.3). This results in a per capita ADWF of 950 L/p/d based on population or
13.1 m3/ha/d based on catchment area. The spring meter data for Main Street was included, as there
was no summer data collected for this location. Also, as the spring metering period for Main Street
extended from February 15 through May 8, 2019, most of the dry weather flow data from this location
was actually collected during winter months.
HEJV Glace Bay WWTP Preliminary Design Brief 4
Table 2.3 Metered ADWF
Meter Area (ha) Population ADWF (m3/day) ADWF (L/p/d) ADWF (m3/ha/d)
Park Street(1) 127 1,893 1,734 916 13.7
May Street(1) 245 2,790 3,087 1,106 12.6
Main Street(2) 113 1,868 1,924 1,030 17.0
GB2(3) 39 504 542 1,075 13.9
GB6(3) 46 713 508 712 11.0
GB7(3) 14 140 164 1,171 11.7
Luke(3) 81 1,268 762 601 9.4
Metered Total 665 9,176 8,721 950 13.1
Notes
(1) Metered during Summer 2018
(2) Metered during Winter/Spring 2018
(3) Metered during Fall 2017
In order to determine a projected total ADWF, the flow for the unmetered areas were calculated using
per capita flow rates from Table 2.3 of 950 L/p/d and 13.1 m3/ha/d (Table 2.4). The total projected
ADWF was calculated to be 13,815 m3/d when calculating the unmetered flow based on population.
Calculating the unmetered flow based on area gave a similar result (13,547 m3/d). The metered data
represents approximately 63% of the total population and 64% of the total catchment area.
Table 2.4 Projected ADWF
Parameter Area (ha) Population ADWF (m3/day)
Metered Flow 665 9,176 8,721
Projected Unmetered Flow (by population) ‐ 5,360 5,094
Projected Unmetered Flow (by area) 368 ‐ 4,826
Projected Total Flow (by population) 13,815
Projected Total Flow (by area) 13,547
2.2.3 Average Flows
The average daily flow (ADF) for each of the meter locations and meter periods is summarized in Table
2.5. This incorporates all metered data, including rain events.
HEJV Glace Bay WWTP Preliminary Design Brief 5
Table 2.5 Flow Meter Data Summary – Average Daily Flows
Meter Area (ha) Population ADF (m3/day) ADF (L/p/d)
Fall Spring Summer Fall Spring Summer
Park Street 127 1,893 ‐ 4,864 1,888 ‐ 2,569 997
May Street 245 2,790 ‐ 7,623 3,112 ‐ 2,732 1,115
Main Street 113 1,868 ‐ 2,760 ‐ ‐ 1,478 ‐
GB2 39 504 819 ‐ ‐ 1,625 ‐ ‐
GB6 46 713 873 ‐ ‐ 1,224 ‐ ‐
GB7 14 140 251 ‐ ‐ 1,793 ‐ ‐
Luke 81 1,268 828 ‐ ‐ 653 ‐ ‐
Metered Total 665 9,176
Serviced Total 1,033 14,536
If the spring data was again omitted for Park Street and May Street, the average daily flow for the
metered catchment areas is 10,531 m3/day for 9,176 people and 665 ha (Table 2.6). This results in a per
capita ADF of 1,148 L/p/d based on population or 15.8 m3/ha/d based on catchment area. Spring data
was omitted from the dataset as it appears to be highly influenced by both high levels of infiltration
during dry weather conditions, thought to be due to a higher groundwater table, as well as inflows.
CBRM intends to undertake a program of inflow and infiltration (I&I) reduction in the Glace Bay sewer
system in order to reduce the flows in the sewer system.
Table 2.6 Metered ADF (spring flows omitted for Park Street and May Street)
Meter Area (ha) Population ADF (m3/day) ADF (L/p/d) ADF (m3/ha/d)
Park Street(1) 127 1,893 1,888 997 14.9
May Street(1) 245 2,790 3,112 1,115 12.7
Main Street(2) 113 1,868 2,760 1,478 24.4
GB2(3) 39 504 819 1,625 21.0
GB6(3) 46 713 873 1,224 19.0
GB7(3) 14 140 251 1,793 17.9
Luke(3) 81 1,268 828 653 10.2
Metered Total 665 9,176 10,531 1,148 15.8
Notes
(1) Metered during Summer 2018
(2) Metered during Spring/Winter 2018
(3) Metered during Fall 2017
In order to determine a projected total ADF, the flow for the unmetered areas were calculated using per
capita flow rates from Table 2.9 for both population and area (Table 2.7). The total projected ADF was
calculated to be 16,682 m3/d when calculating the unmetered flow based on population. When
calculating the unmetered flow based on area, the result was similar (16,359 m3/day). Note that spring
data was omitted from this analysis. Prior to CBRM reducing the level of I&I in the sewer system, the
actual average flows reaching the WWTP are expected to be higher than indicated by this calculation.
HEJV Glace Bay WWTP Preliminary Design Brief 6
The metered data represents approximately 63% of the total population and 64% of the total catchment
area.
Table 2.7 Projected ADF (spring flows omitted)
Parameter Area (ha) Population ADF (m3/day)
Metered Flow 665 9,176 10,531
Projected Unmetered Flow (by population) ‐ 5,360 6,151
Projected Unmetered Flow (by area) 368 ‐ 5,828
Projected Total Flow (by population) 16,682
Projected Total Flow (by area) 16,359
2.2.2 Peak Day Flows
The peak day flow (PDF) for each of the meter locations and meter periods is summarized in Table 2.8.
Table 2.8 Flow Meter Data Summary – Peak Day Flow
Meter (Season) 48hr Rainfall
(mm) Area (ha) Population PDF
m3/day L/p/d m3/ha/d
Park Street (Spring) 51 127 1893 8,140 4,300 64
Park Street (Summer) 49 127 1893 4177 2,207 33
May Street (Spring) 51 245 2790 19,835 7,109 81
Main Street (Spring) 51 113 1868 6,546 3,504 58
GB2 (Fall) 36.8 39 504 3,521 6,986 90
GB6 (Fall) 36.8 46 713 5,163 7,241 112
GB7 (Fall) 36.8 14 140 1,173 8,379 84
Luke (Fall) 9.8 81 1268 1,251 987 15
2.2.3 Extraneous Flow Reduction
It is strongly recommended that additional metering should be carried out in Glace Bay to locate and
reduce sources of inflow and infiltration prior to detailed design.
Efforts to identify and prevent excessive extraneous flow are necessary to allow successful and cost‐
effective treatment of the wastewater, and are assumed to take place in order to realize the design
parameters. If these flows are not able to be removed to the degree assumed, then the WWTP may
experience significant occurrences and/or periods of flow bypass because the design capacity of the
plant is less than the actual flows that the collection system conveys.
2.3 Wastewater Quality Characteristics
HEJV collected one untreated wastewater sample upstream of each of the outfalls in 2018, and the
results are summarized in Table 2.9. For simplicity, only the parameters of relevance to the preliminary
design are included. Refer to the ERA report (attached as Appendix B) for the complete analytical
results. CBRM collected a number of untreated wastewater samples from 2015 through 2017, Dillon
Consulting collected one sample at each of the outfalls in 2014, and UMA Engineering collected a
number of samples in 1992 at the Park Street sewer (upstream of GB8). The results of these historical
samples, combined with the samples collected by HEJV in 2018, are summarised in Table 2.10.
HEJV Glace Bay WWTP Preliminary Design Brief 7
Table 2.9 2018 Wastewater Characterization Results – General Chemistry
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
CBOD5 (mg/L) 32 50 130 84 54 30 64
COD (mg/L) 53 100 200 120 130 41 120
Total NH3‐N (mg/L) 1.4 2.0 3.4 3.8 2.1 0.51 3.7
TSS (mg/L) 25 53 49 41 40 15 50
TP (mg/L) 0.69 0.99 2.2 1.6 1.0 0.3 1.8
TKN (mg/L) 6.0 6.8 16 12 9.2 2.2 13
pH 7.11 7.00 6.79 6.52 7.17 7.18 7.31
Un‐ionized NH3 (mg/L) 0.0049 0.0055 0.0058 0.0035 0.0085 0.0021 0.0207
E. coli (MPN/100mL) 77000 >240000 >240000 130000 >240000 170000 >240000
Nitrate (mg/L) 0.67 0.079 <0.050 0.08 0.79 1.0 <0.050
Nitrite (mg/L) 0.03 0.34 <0.010 0.83 0.06 0.025 <0.010
Nitrate + Nitrite (mg/L) 0.69 0.42 <0.050 0.91 0.85 1.0 <0.050
Table 2.10 Historical Wastewater Characterization Results
Outfall Pop.
TSS (mg/L) CBOD (mg/L) Total Ammonia
(mg/L) TKN (mg/L) pH
#
Samples Avg #
Samples Avg #
Samples Avg #
Samples Avg #
Samples Avg
GB1 558 2 28 2 40 2 2.35 1 6.0 2 7.26
GB2 504 2 54 2 52 2 3.10 1 6.8 2 7.18
GB3 44 1 59 1 290 1 41.0 0 ‐ 1 7.47
GB4 667 28 381 28 43 14 2.17 1 16.0 14 7.33
GB5 118 2 81 2 70 2 3.90 1 12.0 2 6.76
GB6 713 2 61 2 147 2 2.35 1 9.2 2 7.13
GB7 140 2 28 2 43 2 0.56 1 2.2 2 7.18
GB8 11,791 43 105 43 88 2 3.15 5 21.7 26 7.12
Weighted
Average
(by population)
‐ 110 ‐ 86 ‐ 3.13 ‐ 19.5 ‐ 7.13
2.4 Wastewater Loading Analysis
The theoretical per capita loading rates listed in the Atlantic Canada Wastewater Guidelines Manual
(ACWGM) are 0.08 kg BOD/person/day and 0.09 kg TSS/person/day. With a total service population of
14,536, this would result in a loading of 1163 kg BOD/day and 1308 kg TSS/day. Based on an average
dry weather flow of 13,815 m3/day, this would result in average concentrations of 84 mg/L BOD and 95
mg/L TSS during dry weather conditions.
The CBOD concentrations in the wastewater samples collected by HEJV from each of the outfalls ranged
from 30 mg/L to 130 mg/L. The TSS concentrations in the wastewater samples collected by HEJV from
each of the outfalls ranged from 15 to 53 mg/L. The TKN concentrations in the wastewater samples
collected by HEJV ranged from 2.2 mg/L to 16 mg/L. These samples were individual grab samples. The
HEJV Glace Bay WWTP Preliminary Design Brief 8
average of all samples collected upstream of the main outfall (GB8) was 88 mg/L CBOD, 105 mg/L TSS,
and 21.7 mg/L TKN. If the average sample results for each outfall location were weighted by service
population, the weighted average would be a CBOD concentration of 86 mg/L, a TSS concentration of
110 mg/L and a TKN concentration of 19.5 mg/L.
Therefore, we have utilized the data in Table 2.11 as the current loading conditions.
Table 2.11 Current Loading Conditions
Parameter Value
Population 14,536
CBOD (mg/L) 86
CBOD (kg/d) 1188
CBOD (kg/cap/d) 0.082
TSS (mg/L) 110
TSS (kg/d) 1520
TSS (kg/cap/d) 0.105
TKN (mg/L) 19.5
TKN (kg/d) 269
TKN (kg/cap/d) 0.019
HEJV Glace Bay WWTP Preliminary Design Brief 9
CHAPTER 3 BASIS OF DESIGN
3.1 Service Area Population
The primary method used to estimate future wastewater flows and loads is to project current per capita
flows and loads based on estimates of future population. The population for the Glace Bay service area
was obtained from the 2016 Census data contained in CBRM’s GIS database using the following
procedure: Each residential unit within the service area boundary from CBRM’s structure database was
multiplied by the average household size for the census dissemination area that it falls within. For Glace
Bay, the service area population was estimated to be 14,536 people in 7,258 residential units.
The population of the CBRM has been declining and this trend is expected to continue. The latest
population projection study, completed in 2018 by Turner Drake & Partners Ltd., predicted a 17.8%
decrease in population in Cape Breton County between 2016 and 2036. For this reason, no allocation
has been made for any future population growth. For the purpose of this preliminary design study,
WWTP sizing will be based on the current population and measured flow data. While this may seem
overly conservative, due to significant amounts of inflow and infiltration (I&I) observed in sewer systems
in the CBRM, a given population decrease will not necessarily result in a proportional decrease in
wastewater flow. Therefore, basing the design on current conditions is considered the most reasonable
approach.
3.2 Design Flows and Loads
The projected design flows, based on the flow meter data which was summarized in Section 2.2, are:
Projected ADWF (spring data excluded) of 13,815 m3/day (950 L/p/d)
Projected ADF (spring data excluded) of 16,682 m3/day (1148 L/p/d)
For design purposes, it is assumed that average wastewater flows will approach the ADWF of 13,815
m3/day through a significant I&I reduction program. I&I reduction will be an important component of
the project in order to provide flows and loads that can reasonably be designed for. Size limitations of
the available land on which to construct the WWTP also make I&I reduction key.
Due to the size, the WWTP will be a mechanical treatment plant which cannot be efficiently designed for
too wide of a flow range. Typical design values for peaking factors range from 2 to 3.5 for mechanical
treatment plants. As a starting point, a peaking factor of 3 was assumed based on recommendations in
the Industrial Cape Breton Wastewater Characterization Program report by UMA, 1994. A peaking
factor of 3 would result in a peak flow of 41,445 m3/day (2,851 L/p/d), which will be evaluated further
against current flow data to determine the impact that this peaking factor would have on overflow
events.
HEJV Glace Bay WWTP Preliminary Design Brief 10
Of the 83 days in spring 2018 for which there is meter data, 16 had an average daily flow per capita
greater than 2,851 L/p/d. Note that this involves averaging flows over a one‐day period – there may be
periods of time on other days where the flowrate exceeds these values. A plot was prepared of the per
capita flows for the combined Main Street, Park Street, and May Street meters during Spring 2018
(Figure 3.1). The average dry weather and peak design flows are also plotted on this figure on a per
capita basis. Spring flows represent the worst‐case condition for overflows due to increased base flow
associated with higher groundwater tables, and snow melt. The per capita flow rates were multiplied by
the total service population to give a projected total flow in m3/day (Figure 3.2). However, the data was
based on spring flow data from the Main Street, Park Street, and May Street meters only and may not
accurately represent the flow from the other areas of the system.
Figure 3.1 Combined Per Capita Spring Flows for Main Street, Park Street, and May Street Meters
0
10
20
30
40
50
600
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
10,000
Feb‐14 Feb‐24 Mar‐06 Mar‐16 Mar‐26 Apr‐05 Apr‐15 Apr‐25 May‐05
Ra
i
n
(m
m
)
Pe
r
Ca
p
i
t
a
Fl
o
w
(L
/
p
/
d
)
Per Capita Metered Flow (L/p/d)ADWF PF Rain (mm)
HEJV Glace Bay WWTP Preliminary Design Brief 11
Figure 3.2 Projected Spring Flows based on Main Street, Park Street, and May Street Meter Data
For comparison purposes, a plot was prepared (Figure 3.3) of the per capita flows for the Park Street
meter during summer 2018. The average dry weather and peak design flows are also plotted on this
figure on a per capita basis. Although the Park Street meter was the only meter with data for this time
period, there was only one event where the metered flow exceeded the peak design flow for the plant
on a per capita basis, and it was associated with a 47.8mm rain event. As above, the per capita flow
rates were multiplied by the total service population to give a projected total flow in m3/day (Figure
3.4). However, the data was based on flow data from the Park Street meter location only and may not
accurately represent the flow from the other areas of the system.
0
10
20
30
40
50
600
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Feb‐14 Feb‐24 Mar‐06 Mar‐16 Mar‐26 Apr‐05 Apr‐15 Apr‐25 May‐05
Ra
i
n
(m
m
)
Pr
o
j
e
c
t
e
d
Fl
o
w
(m
3/d
)
Projected Flow ADWF PF Rain (mm)
HEJV Glace Bay WWTP Preliminary Design Brief 12
Figure 3.3 Per Capita Summer Flows for Park Street Meter
Figure 3.4 Projected Summer Flows based on Park Street Meter Data
0
10
20
30
40
50
600
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
10,000
Aug‐06 Aug‐10 Aug‐14 Aug‐18 Aug‐22 Aug‐26 Aug‐30 Sep‐03 Sep‐07
Ra
i
n
(m
m
)
Pe
r
Ca
p
i
t
a
Fl
o
w
(L
/
p
/
d
)
Per Capita Metered Flow (L/p/d)PF ADWF Rain (mm)
0
10
20
30
40
50
600
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Aug‐06 Aug‐10 Aug‐14 Aug‐18 Aug‐22 Aug‐26 Aug‐30 Sep‐03 Sep‐07
Ra
i
n
(m
m
)
Pr
o
j
e
c
t
e
d
Fl
o
w
(m
3/d
)
Projected Flow PF ADWF Rain (mm)
HEJV Glace Bay WWTP Preliminary Design Brief 13
Therefore, the average and peak day design flows chosen for the Glace Bay WWTP preliminary design
are 13,815 and 41,445 m3/d, respectively. The average design flow is based on ADWF conditions. It is
assumed that average flows will approach this value in the future through sewer separation and I&I
reduction efforts. Although design flows are not representative of current flow conditions, an I&I
reduction program and subsequent flow metering program are planned as part of the detailed design
phase of the project. It is important that flow reduction be achieved as the proposed site has limited
space and cannot accommodate a larger WWTP.
3.3 Effluent Requirements
The effluent requirements will include the federal Wastewater Systems Effluent Regulations (WSER)
limits, along with provincial effluent requirements determined by Nova Scotia Environment (NSE) and
presented in the NSE Approval to Operate for the WWTP. An ERA was completed by HEJV in 2018 which
determined effluent discharge objectives for parameters not included in the WSER (See Appendix B).
The receiving water for the Glace Bay WWTP will be the Atlantic Ocean, adjacent to Glace Bay Harbour.
The ERA generally followed Technical Supplement 3 of the Canada‐wide Strategy for the Management of
Municipal Wastewater Effluent – Standard Method and Contracting Provisions for the Environmental
Risk Assessment. Dilution modelling was conducted to determine the maximum 1‐day average effluent
concentration with a mixing zone boundary of 100m for all parameters of concern with the exception of
E. coli for primary contact recreation. The E. coli concentration was analyzed at the edge of the 100m
mixing zone for secondary contact recreation, and at Big Glace Bay and Table Head beaches for primary
contact recreation.
Refer to Table 5.1 in the ERA attached in Appendix B for Effluent Discharge Objectives (EDOs) developed
during the ERA and for further information on the development of these values.
The effluent requirements resulting from the ERA are summarized in Table 3.1 along with the source of
the criteria. As EDOs are calculated values, they are not round whole numbers that are typical of
effluent requirements; therefore, we have included both the EDOs and values that are more suited as
effluent requirements in the table. The ERA values were obtained based on the assumption of an
extension to the existing outfall to attain additional dilution. This assumption will be revisited and EDOs
confirmed after the final configuration of the outfall is determined. Refer to the ERA in Appendix B for
details on the modelled conditions.
Table 3.1 Design Effluent Requirements
Parameter EDO Required By Effluent Limit
CBOD5 (mg/L) 25 WSER 25
TSS (mg/L) 25 WSER 25
Un‐ionized Ammonia (as NH3‐N) (mg/L) 1.25 WSER 1.25
Total Residual Chlorine (TRC) (mg/L) 0.02 WSER 0.02
E. coli (E. coli/ 100mL) 22,208 ERA 10,000
Total Ammonia (as N) (mg/L) 66.5 ERA 65
TKN (mg/L) 19.9 ERA 20
Phosphorus (mg/L) 1.6 ERA 1.5
3.4 Summary
The wastewater concentrations vary significantly as was shown in Sections 2.3 and 2.4. For design
purposes, we are going to assume an average CBOD concentration of 100 mg/L and an average TSS
concentration of 110 mg/L. During wet weather, the concentrations can decrease drastically therefore
HEJV Glace Bay WWTP Preliminary Design Brief 14
calculating peak loads by combining peak flows and average concentrations is not recommended as it
will result in an oversized facility. However, there will be some variation in loading both throughout the
day (diurnal effect) and day to day due to activity in the community. Allowing the peak load to be 2x the
average load results in a peak load of 2763 kg/d CBOD and 3039 kg/d which will result in concentrations
of 67 mg/L CBOD and 73 mg/L TSS during the peak period.
Table 3.2 Design Criteria Summary
Parameter Average Day Peak Day
Design Population 14,536
Flow (m3/day) 13,815 41,445
Strength
CBOD (mg/L) 100 67
TSS (mg/L) 110 73
TKN (mg/L) 19.5 13.0
Loading
CBOD (kg/day) 1381.5 2763
TSS (kg/day) 1519.7 3039
TKN (kg/day) 269 538
HEJV Glace Bay WWTP Preliminary Design Brief 15
CHAPTER 4 TREATMENT PROCESS ALTERNATIVES
The effluent criteria requires the selection of a secondary treatment process. Secondary treatment
processes are predominantly aerobic biological processes designed to convert the finely dispersed and
dissolved organic matter in the raw wastewater into flocculent settleable biological cell tissue (biomass)
which can be removed by sedimentation. These biological processes are the most efficient in removing
organic substances that are either dissolved or in the colloidal size range (too small to settle out),
whereas primary treatment processes are the most efficient in removing larger particles of suspended
solids which can be removed by sedimentation, fine screening, or filtration.
4.1 Preliminary Treatment
A variety of secondary treatment process options will be evaluated. However, each option will require
preliminary treatment of the wastewater. The purpose of preliminary treatment processes is to remove
objectionable materials and inorganic particles from the wastewater prior to treatment. These
processes may include screening or coarse solids reduction, and grit removal.
4.1.1 Screening
Screens used in preliminary treatment applications are classified based on the size of openings as either
coarse (6 to 150 mm openings) or fine (less than 6 mm openings).
Coarse screens are used to remove large objects that could damage or clog downstream equipment, so
they are typically the first unit operation in a wastewater treatment plant. Coarse screens may be either
manually or mechanically cleaned. There are a number of mechanical cleaning system options available,
including continuous chain driven rakes, reciprocating rake, and continuous belt.
Fine screens provide increased solids capture compared to coarse screens. In addition to their use in
preliminary treatment, they may also substitute for clarifiers as primary treatment, or for treatment of
combined sewer overflows. There are several options available for fine screening. Band screens consist
of a continuous screen made of panels with punched holes that allow water to pass through and debris
to be captured. The debris collected on the screen is removed as the screen is raised out of the water as
part of its normal rotation. Any debris remaining on the screen will enter the water downstream of the
screen as the screen passes through the water.
Rotating perforated plate screens consist of a continuous screen made of panels with punched holes
that allow water to pass through and debris to be captured. The debris collected on the screen is
removed as the screen is raised out of the water as part of its normal rotation. Any debris remaining on
the screen will enter the water downstream of the screen as the screen passes through the water.
HEJV Glace Bay WWTP Preliminary Design Brief 16
The step screen operation is considerably different from the band screen. It is a single piece screen that
does not rotate. The screen is configured in steps and the solids collected on the steps of the screen are
lifted to the next step by tines. The screen has continuous opening to allow for the tines to lift the
screenings from one step to the next and relies on the formation of a filtering mat to assist in the
screening process. This operation results in the screenings being re‐handling on the screen several
times before it is removed which can cause the screenings to breakdown and pass through the screen
and re‐enter the water downstream of the screen.
In general, for a given aperture size, band screens have higher solids capture ratios than step screens.
Screenings should then be directed to a washer compactor to reduce the volume of screenings and
return organics to the process so they can be treated.
4.1.2 Grit Removal
Grit chambers are used to remove non‐biodegradable materials such as sand, gravel, cinders, or other
heavy solid material with specific gravities greater than those of organic solids in the wastewater. The
purpose of grit removal is to protect mechanical equipment from abrasion and wear, and to reduce the
formation of heavy deposits in pipelines, channels, and conduits.
Typical grit chamber configurations include horizontal flow‐through, aerated, and vortex. New
applications generally use aerated or vortex‐style grit chambers.
In aerated grit chambers, coarse bubble diffusers are installed along one side of each rectangular tank to
create a spiral flow pattern that is perpendicular to the flow through the chamber. This spiral pattern
causes the grit to settle in the tank and helps keep organic particles in suspension, so they can pass
through the tank and be treated in downstream processes. The performance of an aerated grit chamber
can be controlled by adjusting the quantity of air that is supplied. If the spiral velocities are too low then
organics may settle in the chamber, causing excessive quantities of organics in the dried grit. If the
spiral velocities are too high, then grit may not settle in the chamber. The grit that settles in an aerated
grit chamber settles in a trough that spans the length of the chamber.
There are a number of options available for removing grit from the trough, including:
• Grab buckets mounted to monorails;
• Chain and bucket systems; and
• Spiral conveyors and grit pumps.
Vortex‐style grit chambers are common in new applications. These systems function by inducing a
helical flow pattern in the tank, and the resulting centrifugal forces cause grit to settle in a hopper. Grit
is then removed from the hopper using a grit pump.
Once grit is removed from the main treatment process, the slurry is then pumped or conveyed to a
classifier for separation and washing. Classifiers may be equipped with a hydrocyclone at the inlet to
reduce slurry volumes through centrifugal separation prior to discharging to the classifier tank. Grit that
settles in the classifier is removed by an auger or rake and discharged to a disposal bin until there are
sufficient quantities for disposal in a landfill.
4.2 Secondary Treatment
There are many types of secondary treatment processes available, most of which can be classified as
either suspended growth or attached growth systems. Suspended growth systems use aeration and
mixing to keep microorganisms in suspension and achieve a relatively high concentration of these
microorganisms (biomass) through the recycle of biological solids. Attached growth systems provide
surfaces (media) on which the microbial layer can grow, and expose this surface to wastewater for
HEJV Glace Bay WWTP Preliminary Design Brief 17
adsorption of organic material and to the atmosphere and/or diffused aeration for oxygen. A listing of
specific secondary treatment processes and the category to which they belong is presented in Table 4.1.
Table 4.1: Secondary Treatment Processes
Process Category Specific Process
Suspended Growth Activated Sludge
Extended Aeration
Pure Oxygen Activated Sludge
Sequencing Batch Reactor (SBR)
Oxidation Ditch
Membrane Bio‐Reactor (MBR)
Attached Growth Rotating Biological Contactor (RBC)
Trickling Filter
Biological Activated Filter (BAF)
Moving Bed Bio‐Reactor (MBBR)
Land‐Based Constructed Wetlands
Aerated Lagoon
Facultative Lagoon
HEJV has worked on projects using the majority of the technologies in Table 4.1 so we are able to use
our considerable practical experience to narrow down the list of available technologies to those best
satisfying the project constraints.
4.2.1 Site‐specific Suitability
The main constraints at this site that will influence which of the available options are best suited for the
Glace Bay WWTP are: effluent requirements, site conditions, cost effectiveness, and ease of operation.
Each of these is discussed below.
4.2.2.1 4.2.1.1 EFFLUENT REQUIREMENTS
The effluent requirements summarized in Section 3.3 can be met by all of the listed technologies in
Table 4.1 with the exception of the facultative lagoon, which has been eliminated from further
consideration.
4.2.1.2 SITE CONDITIONS
Figure 4.1 provides an overview of the general area that has been identified as the location of the Glace
Bay WWTP since the Report on Pollution Control Study for the Town of Glace Bay that was prepared by
C.A. Campbell in 1985.
There is a parcel owned by CBRM (PID 15864085) that is bounded by Lower North Street to the west,
the Atlantic Ocean to the north, a property owned by Public Works and Government Services Canada
(PID 15524473) to the east, and a property owned by Hopkins H Ltd. (PID 15408867) to the south. The
property ranges from sea level along the Atlantic Ocean to 8m elevation near the southwest corner of
the property. The CBRM property is not large enough for any of the secondary treatment processes
presented in Table 4.1 with the possible exception of a membrane bioreactor (MBR). It appears that
construction of a WWTP will likely require either the acquisition of additional land and/or infilling of the
shoreline.
A portion of the Hopkins property to the south houses buildings associated with a fish plant. The
existing sanitary sewer leading to the outfall currently crosses through this property. At a minimum, this
property will likely house a pump station to feed the new WWTP with an overflow structure.
j o i n t v e n t u r e FIG 4.1
HEJV Glace Bay WWTP Preliminary Design Brief 18
West of Lower North Street, there are three privately owned properties, one owned by Charles H. Rigby
(PID 15821119 (18,725 ft2)) and two owned by Marilyn Gillard (PIDs 15833007 (11,000 ft2)) and
15395221 (28,957 ft2)) and a portion of the Bayplex Property (numerous owners) (PID 15654882). The
topography ranges from 9m along Lower North Street to 11m to the northwest. It appears that fill has
been disposed of on these properties. Behind these properties is a large parcel owned by Cape Breton
Regional Housing Authority (PID 15393606 (13.42 acres)). The topography ranges from 11m to the
southeast to 16m to the northwest.
There are a number of houses along Lower North Street that are in fairly close proximity to the general
site, along with a fish plant, Cameron’s Building Supplies, and the Bayplex.
HEJV have eliminated wetlands, aerated lagoon, oxidation ditch, extended aeration, trickling filter, and
RBC technologies from further consideration as they require additional area that is not available at this
site. Another important consideration of the site will be elevations and the hydraulic grade line (HGL)
through the treatment process. The tidal elevations at the site include a higher high‐water elevation at
large tide of 1.1m (CGVD28). The estimated extreme values for 100 year and 50‐year return periods are
2.1m (CGVD28) and 2.0m (CGVD28), respectively. In addition, a sea level rise of at least 1.0 m is likely to
occur within the coming century, even if the timeline remains uncertain (CBCL, 2018). This will set the
minimum point for the HGL as treated effluent will have to discharge from the WWTP by gravity through
the outfall.
Available siting options include PIDs 15864085 and 15408867 which are situated to the southeast of
North Street. This site is also the location of Fisherman’s Memorial Park and sees vehicle traffic
associated with the views of the ocean. At a minimum this site would likely house the main plant lift
station due to the existing outfall crossing the site.
The area to the northwest of North Street has sufficient available land to house a WWTP. However, the
WWTP infrastructure would be situated within 150m of residential properties as well as adjacent to the
Bayplex. The Atlantic Canada Wastewater Guidelines Manual (ACWGM) recommends that mechanical
plants be located a minimum of 150m from residences, 30m from commercial/industrial developments,
and 30m from property lines. However, a lesser separation distance may be adopted provided odour
control is provided at the plant.
Due to the presence of underground mine workings in the area, intrusive geotechnical investigations
were conducted at each of the general site locations mentioned above (See Appendix C). The
geotechnical investigation encountered voids, likely associated with the former Stirling Mine, to the
north of Lower North Street. No voids were encountered to the south of Lower North Street. However,
as only two boreholes were advanced to the depth of the coal seam, additional geotechnical work is
recommended as part of detailed design.
4.2.1.3 COST EFFECTIVENESS
There are a number of processes in Table 4.1 that can be eliminated based on their cost effectiveness
compared to other processes in the table. For example, pure‐oxygen activated sludge is more costly
than conventional activated sludge due to its requirement for specific equipment to reduce the
footprint of the activated sludge process. Utilizing similar logic, extended air, and oxidation ditches are
inherently less cost effective than SBR. As well, other recent evaluations have identified MBBR as bring
more cost effective than other fixed film options. Membrane bioreactors (MBR) are also not considered
a cost‐effective treatment process when the effluent discharge criteria do not necessitate their use.
However, due to the land constraints, an MBR is one option that could conceivably be constructed on
the property owned by CBRM and therefore will be evaluated as an option.
HEJV Glace Bay WWTP Preliminary Design Brief 19
4.2.1.4 EASE OF OPERATION
The remaining technologies typically require similar levels of operational expertise, which we would
classify as moderate. However, there is an operational benefit to utilizing an SBR process as the CBRM
WWTP operations staff have experience with this type of process already.
4.2.2 Description of Candidate Processes for Secondary Treatment
Based on the preceding analysis, the following processes should be given further consideration:
Conventional Activated Sludge (CAS);
Sequencing Batch Reactor (SBR);
Moving Bed Bio‐Reactor (MBBR); and
Membrane Bio‐Reactor (MBR).
Each of these processes is described below. Each of the secondary treatment processes will have similar
solids stream trains, so the sludge handling processes will not be evaluated at this stage. Similarly, the
costs associated with site access, outfall, electrical service, etc. will not be evaluated as part of the
secondary treatment process comparison.
4.2.2.1 CONVENTIONAL ACTIVATED SLUDGE
The activated sludge (AS) process is a continuous‐flow, aerobic suspended‐growth biological treatment
process that has become the most common method of treatment for BOD and TSS removal. In the
activated sludge process, organic waste material is decomposed by microorganisms such as bacteria,
fungi, protozoa and rotifers, which use the waste, or “food”, as energy in the synthesis of new cells.
Aeration is required for the cellular respiration. Many variations of the process currently exist.
The conventional activated sludge process follows the primary treatment step. The effluent from the
primary clarifier serves as the influent for the AS process. The biological treatment is carried out in the
AS reactor, in which aeration is provided to keep the biomass and waste material in suspension, as well
as ensure completely mixed conditions in the reactor. This is required to promote contact between the
microorganisms, waste material, and oxygen. The mixture is commonly referred to as the “mixed
liquor”. The hydraulic retention time – defined as the average amount of time a water molecule spends
in a tank – in conventional AS reactors is typically 6 to 10 hours under average flow conditions.
Somewhat larger reactors and additional aeration capacity are required if nitrification is to be achieved
in addition to carbonaceous BOD reduction.
The flocculent biomass from the AS reactor discharges to a secondary clarifier (typically circular) where
biological floc material is settled out in a similar manner to that of a primary clarifier. In order to
maintain a sufficient concentration of activated sludge in the aeration tank, a portion of the sludge that
is collected in the secondary clarifier is recycled to the aeration tank. This recycled portion is referred to
as return activated‐sludge (RAS). Excess sludge, the waste activated‐sludge (WAS), is removed from the
system on a regular basis in order to control the solids retention time (SRT), which is defined as the
average amount of time the sludge has remained in the system. WAS is typically discharged to a
thickening process. Typical SRTs for activated sludge processes range from 4 to 15 days.
A typical conventional activated process schematic is provided in Figure 4.2. Primary clarification is not
shown in the figure; however, the influent to the process is effluent from a primary clarifier.
HEJV Glace Bay WWTP Preliminary Design Brief 20
Figure 4.2: Typical Activated Sludge Process Schematic
A conceptual level cost estimate has been developed for this option based on the projected design flow and
loads, as well as on the design parameters listed in Table 4.2.
Table 4.2: Conventional Activated Sludge Process Design Criteria
Parameter Proposed Typical Design
Standard
No. of Primary Clarifiers 2 ‐
Length (m) x Width (m) 30.3 x 7.6 ‐
Depth 4.3 3 – 4.9
Primary Clarifier Average/ Peak
SOR (m3/m2/d) 30 / 90 40 / 100
Detention Time (hr) 3.4 1.5 – 2.5
Total Reactor Volume (m3) 4,605 ‐
Average HRT (hr) 8 6 ‐ 10
Peak Day HRT (hr) 2.7 3 ‐ 4
MLSS (mg/L) 1500 1500 – 4000
Average F/M Ratio 0.27 0.2 – 0.6
No. of Secondary Clarifiers 2 ‐
Diameter (m) 21 ‐
Depth (m) 4.5 3.5 ‐ 6
Secondary Clarifier Average SLR
(kg/m2hr) 1.2 4‐6
Secondary Clarifier Peak SLR
(kg/m2hr) 3.6 8
Secondary Clarifier Average SOR
(m3/m2/d) 20 16‐28
Secondary Clarifier Peak SOR
(m3/m2/d) 60 40‐64
Aeration
Tank
Secondary
Clarifier
RA
S
Secondary
Effluent
Blowers
WA
S
to
Di
g
e
s
t
e
r
HEJV Glace Bay WWTP Preliminary Design Brief 21
4.2.2.2 SEQUENCING BATCH REACTOR
The Sequencing Batch Reactor (SBR) process is also an aerobic suspended‐growth biological treatment
process and is essentially a modified version of the completely mixed activated sludge process, with the
main difference being the mode of operation. The SBR process is a batch process whereby secondary
treatment, including nitrification, is achieved in one reactor. The SBR process is a “fill and draw” type
reactor where aeration and clarification occur in the same reactor. Settling is initiated after the aeration
cycle, and supernatant is withdrawn through a decanter mechanism.
An example of the cycles used in the SBR process is summarized below. However, there are variations
between different manufacturers.
1. Fill – Preliminary treatment effluent enters the anoxic pre‐react zone in the SBR tank. The anoxic
conditions favor the procreation of microorganisms with good settling characteristics. The
wastewater then flows into the react zone of the SBR.
2. React – The microorganisms contact the substrate and a large amount of oxygen is provided to
facilitate the substrate consumption. During this period aeration continues until complete
biodegradation of BOD and nitrogen is achieved. During this stage some microorganisms will die
because of the lack of food and will help reduce the volume of the settling sludge. The length of the
aeration period determines the degree of BOD consumption.
3. Settle – Aeration is discontinued at this stage and solids separation takes place leaving clear, treated
effluent above the sludge blanket. During this clarifying period no liquids typically leave the tank to
avoid turbulence in the supernatant.
4. Decant – This period is characterized by the withdrawal of treated effluent from approximately two
feet below the surface of the mixed liquor by the floating solids excluding decanter. This removal
must be done without disturbing the settled sludge.
5. Idle – An idle period can be provided between cycles. Sludge wasting can also occur during this
time.
The process is generally implemented using a minimum of two (2) reactors in parallel. It can be
conducted as a batch process where one reactor is filling while the other is settling. Continuous‐feed
SBRs are also available which receive influent during all phases of the treatment cycle and decant
intermittently. No RAS is required as the mixed liquor remains in the reactor at all times, with WAS
being withdrawn as necessary. The entire process is controlled using a programmable logic controller
(PLC). A general process schematic for the SBR system is provided in Figure 4.3.
HEJV Glace Bay WWTP Preliminary Design Brief 22
Figure 4.3: Typical Sequencing Batch Reactor Process Schematic
SBRs are operated at long solids and hydraulic retention times, resulting in large reactor volumes;
however, the total number of tanks required is reduced, which can result in more compact site layouts.
Furthermore, since flow equalization is inherently provided in SBR systems, the process is much more
resistant to shock loadings, making it an attractive alternative for small to medium sized facilities. Due
to the degree of control required and the large volume of tankage required in each reactor, the capital
costs are often higher than more conventional activated sludge processes for larger plants. The
discharge for smaller systems is typically intermittent in nature, which can result in larger, more
expensive UV disinfection systems.
A conceptual level cost estimate has been developed for this option based on the projected design flow,
loads, and design parameters listed in Table 4.3.
WAS to Digester
Preliminary
Effluent
Blower
Aeration Tank
2. React
Secondary
Effluent
Blower
Aeration Tank
1. Fill
Secondary
Effluent
Blower
Aeration Tank3. Settle
Secondary
Effluent
Blower
Aeration Tank4. Draw
Secondary
Effluent
WAS
Preliminary
Effluent
Preliminary
Effluent
Preliminary
Effluent
HEJV Glace Bay WWTP Preliminary Design Brief 23
Table 4.3: Sequencing Batch Reactor Process Design Criteria
Parameter Proposed Typical Design
Standard
No. of Reactors 3 3‐4
Basin Length (m) 45.8 ‐
Basin Width (m) 18.3 ‐
Side Water Depth (m) 5.5 ‐
Total Reactor Volume (m³) 13,829 ‐
Design HRT (hr) 24 15 ‐ 40
Cycles per Reactor per Day
(average/ peak) 6 / 8 4 – 6
React Time (min) (average/ peak) 120 / 90 60 – 120
Settling Time (min) (average/
peak) 60 / 30 30 – 60
Volumetric BOD5 Loading (kg
BOD /m³d) 0.1 0.1 – 0.3
MLSS (mg/L) 3000 2000 – 5000
F/M Ratio 0.07 0.04 – 0.1
4.2.2.3 MOVING BED BIO‐REACTOR
The patented Moving Bed Bio‐Reactor (MBBR) process was developed by the Norwegian company
Kaldnes Miløteknologi (KMT). MBBRs are a system based on a biofilm reactor with no need for
backwashing or return sludge flow. The MBBR contains what is termed as a “carrier” which is a
manufactured (typically plastic) media with a high specific surface area for biofilm to grow. The specific
gravity of the carrier is slightly less than that of water so that aeration will keep the contents in
suspension and completely mixed. The movement is normally caused by coarse‐bubble aeration.
Abrasion of the media carriers sloughs off and maintains optimal biofilm thickness.
Effluent from preliminary treatment serves as the influent to the MBBR unit. MBBR effluent containing
suspended solids then overflows to a secondary clarifier or DAF clarifier for solids removal; however, the
carrier material remains in the reactor. A typical MBBR process schematic is provided in Figure 4.4.
HEJV Glace Bay WWTP Preliminary Design Brief 24
Figure 4.4: Typical Moving Bed Bio‐Reactor Process Schematic
A conceptual level cost estimated has been developed for this option based on the projected design flow,
loads, and design parameters listed in Table 4.4.
Table 4.4: Moving Bed Bio‐Reactor Process Design Criteria
Parameter Proposed
No. of Trains 1
No. of Stages 1
Total Reactor Volume (m³) 1500
Average / Peak HRT (hr) 2.6 / 0.87
Side Water Depth (m) 5.5
Average /Peak BOD5 Loading (g/m2d)(1) 2.1 / 4.2
Specific Surface Area (m²/m³) 800
Secondary DAF Clarifier Average / Peak
SOR (m/d) 408 / 600
(1) Assumes 55% fill rate
4.2.2.4 MEMBRANE BIO‐REACTOR
The membrane bio‐reactor (MBR) process involves an aerobic suspended‐growth biological treatment
process followed by a membrane filtration system. Benefits of an MBR system include a reduced
footprint and tertiary quality effluent without the requirements for a secondary clarifier. However, they
are typically not cost effective if effluent discharge requirements do not require their use. Use of the
MBR process would require additional screening (2mm perforated screen) beyond the fine screening
and grit removal required by the other options.
Aeration
Tank Secondary
Clarifier
Secondary
Effluent
Blowers
Carrier
WAS
HEJV Glace Bay WWTP Preliminary Design Brief 25
A conceptual level cost estimate has been developed for this option based on the projected design flow and
loads, as well as on the design parameters listed in Table 4.5.
Table 4.5: MBR Process Design Criteria
Parameter Proposed
No. of Trains 4
No. of Cassettes per Train 7
No. of Modules 1448
Total Reactor Volume (m³) 1704
Average / Peak HRT (hr) 3 / 1
4.3 Disinfection
Disinfection at WWTPs is typically provided using either chlorination or UV disinfection. Due to the TRC
limit in the WSER, use of chlorine disinfection requires a dechlorination system. In addition, a UV
disinfection system is preferable from a safety perspective, and minimizes chemical handling.
UV systems are typically sized for 200 total coliform/ 100mL. UV Disinfection is a physical disinfection
process that targets microorganisms such as viruses, bacteria, and protozoa by destroying their ability to
reproduce. Pathogen inactivation is directly linked to UV dose, which is the product of the average UV
intensity and the duration of exposure, or retention time. Any factor affecting light intensity or
retention time will also affect disinfection effectiveness. Some of the key parameters that affect UV
intensity include water quality issues such as:
UV transmission;
Suspended solids;
Presence of dissolved organics, dyes, etc.;
Hardness; and
Particle size distribution.
Other factors affecting UV performance include sleeve cleanliness, age of lamps, upstream treatment
processes, flow rate and reactor design.
4.3.1 CAS, MBBR or MBR Effluent Disinfection
Flows from the CAS, MBBR or MBR system will continuously flow by gravity to the ultraviolet (UV)
disinfection unit. Disinfection will take place in a single concrete channel located in the new WWTP
building. The UV system will consist of two banks of UV lamps. The lamps are oriented in a staggered
inclined array and contain fourteen lamps per bank for a total of twenty‐eight (28) lamps. The design
parameters for the UV disinfection system are summarized in the table below.
Table 4.6: UV Disinfection Design Parameters
Parameter Design Value
Number of Design Channels 1
Number of Banks 2
Number of Lamps per Bank 14
Total Number of Lamps 28
Peak Flow Capacity (m3/d) 45,000
Effluent TSS (mg/L) <25
Minimum Transmission (%T) 60
Effluent Fecal Coliforms (MPN/100 mL) 200
The disinfected effluent would flow by gravity to the outfall.
HEJV Glace Bay WWTP Preliminary Design Brief 26
4.3.2 SBR Effluent Disinfection
Flows from the SBR system will flow intermittently by gravity to the ultraviolet (UV) disinfection unit
during the decant cycle. This results in a larger UV system being required than for the CAS, MBBR or
MBR process as it is sized for the peak decant rate from the SBR. Disinfection will take place in a single
concrete channel located in the new WWTP building. The UV system will consist of two banks of UV
lamps. The lamps are oriented in a staggered inclined array and contain sixteen lamps per bank for a
total of thirty‐two (32) lamps. The design parameters for the UV disinfection system are summarized in
the table below.
Table 4.7: UV Disinfection Design Parameters
Parameter Design Value
Number of Design Channels 1
Number of Banks 2
Number of Lamps per Bank 16
Total Number of Lamps 32
Peak Flow Capacity (m3/d) 51,784
Effluent TSS (mg/L) <25
Minimum Transmission (%T) 60
Effluent Fecal Coliforms (MPN/100 mL) 200
The disinfected effluent would flow by gravity to the outfall.
4.4 Sludge Management
Each of the secondary treatment options evaluated will produce sludge which must be removed from
the treatment process on a regular basis and disposed of at an approved facility. Regardless of which
secondary treatment option is selected, sludge management at this facility will likely involve an aerated
sludge holding tank followed by dewatering. After the recommended secondary treatment process has
been selected, a preliminary design of the solids management train will be provided in Chapter 5.
4.5 Secondary Treatment Option Evaluation
Capital and operating costs have been developed for each of the secondary treatment options
presented in this section for the purposes of evaluating the technology options. At this stage, only the
liquid treatment stream has been evaluated. As each option will involve a similar solids treatment train,
it has not been included as part of the comparison. Similarly, items such as site access, outfall, electrical
service etc. that are common to each option have not been included at this stage in the evaluation. A
discussion has also been provided on qualitative factors associated with each of the secondary
treatment options.
4.5.1 Capital Cost Estimate
Capital cost estimates are provided in Table 4.8. These are comparative cost estimates for secondary
process alternatives only and exclude sludge management, outfall upgrades, main lift station, and site
works that would be common to all options. Of the four (4) options, the CAS process has the lowest
capital cost, with SBR a close second (approximately 10% higher). This difference is within the accuracy
of a Class D cost estimate, however.
HEJV Glace Bay WWTP Preliminary Design Brief 27
Table 4.8 Secondary Process Capital Cost Comparison
Cost CAS SBR MBR MBBR
Estimated Capital Cost $18,274,000 $20,236,000 $25,192,000 $25,296,000
4.5.2 Operating and Lifecycle Cost Estimate
The operating cost comparison is provided in Table 4.9 with a life‐cycle comparison presented in Table
4.10. Of the four (4) options, the SBR process has the lowest operating cost while the CAS process has a
slightly lower life cycle cost. If the life cycle cost was adjusted to account for CBRM paying 27% of the
capital cost based on the Investing in Canada Plan (Table 4.11), the SBR process would have the lowest
life cycle cost.
Table 4.9 Secondary Process Annual Operating Cost Comparison
Operation Annual Operating Cost (Secondary Process Only)
CAS SBR MBR MBBR
Power(1) $170,000 $110,000 $300,000 $100,000
Chemicals(2) $0 $0 $5,000 $27,000
Membrane Replacement(3) $0 $0 $160,000 $0
Maintenance Allowance(4) $30,000 $27,000 $40,000 $68,000
Total $200,000 $137,000 $505,000 $195,000
Notes:
(1) Power estimated based on secondary treatment equipment only.
(2) Allowance for polymer dosing for the MBBR DAFs and membrane cleaning chemicals for
the MBR.
(3) Cost of membrane replacement divided by 10‐year membrane life span.
(4) Maintenance allowance of 1% of equipment cost
Table 4.10 Secondary Process Life Cycle Cost Comparison
Cost CAS SBR MBR MBBR
Estimated Capital Cost $ 18,274,000 $20,236,000 $ 25,192,000 $ 25,296,000
Estimated Annual Operating Cost, $/yr $ 200,000 $ 137,000 $ 505,000 $ 195,000
NPV Equipment Replacement (20
years, 2% interest, 8% discount rate) $ 848,069 $ 768,662 $ 1,959,771 $ 1,642,142
NPV Operating Cost (30 years, 8%
discount rate) $ 2,251,557 $ 1,542,316 $ 5,685,181 $ 2,195,268
Life Cycle Cost $ 21,373,626 $22,546,979 $ 32,836,952 $ 29,133,410
HEJV Glace Bay WWTP Preliminary Design Brief 28
Table 4.11 Secondary Process Life Cycle Cost Comparison – 73% Capital Funding
Cost CAS SBR MBR MBBR
Estimated Capital Cost $ 4,933,980 $ 5,463,720 $ 6,801,840 $ 6,829,920
Estimated Annual Operating Cost, $/yr $ 200,000 $ 137,000 $ 505,000 $ 195,000
NPV Equipment Replacement (20 years,
2% interest, 8% discount rate) $ 848,069 $ 768,662 $ 1,959,771 $ 1,642,142
NPV Operating Cost (30 years, 8%
discount rate) $ 2,251,557 $ 1,542,316 $ 5,685,181 $ 2,195,268
Life Cycle Cost $ 7,185,537 $ 7,006,036 $ 12,487,021 $ 9,025,188
4.5.3 Qualitative Evaluation Factors
In addition to life‐cycle cost, there are a number of other factors to consider when evaluating the
technology options that are less easily quantified. These factors are summarized in Table 4.12, and
additional discussion is provided below the table. Qualitative factors have been rated 1 through 4 for
each technology with 1 being the best and 4 being the worst.
Table 4.12 Secondary Process Qualitative Evaluation Factors
Factor CAS SBR MBBR MBR
Local Experience with Process 2 1 3 3
Operational Simplicity 2 1 3 4
Sludge Production 2 1 4 3
Footprint 4 3 2 1
In terms of local experience with the treatment process, CBRM operations staff have experience with
the SBR process at the Dominion WWTP. Although the Glace Bay WWTP will be larger than the
Dominion SBR plant, the process is generally the same. CBRM operations staff also have experience
with the primary clarification step in the CAS process at Battery Point. The MBBR and MBR process
would be new to CBRM operations staff, and there are also limited other installations in Atlantic Canada.
When considering operational simplicity, both the SBR and CAS processes are fairly straightforward
although each has their own benefits. The SBR process is more automated while the CAS process allows
for greater operator control.
Each of the secondary treatment processes evaluated will produce sludge that will have to be removed
from the process. The longer HRT provided in the SBR will result in a slightly lower sludge production
than the CAS process. As the MBBR is designed to remove soluble BOD only, with insoluble BOD being
removed as particles in the DAF clarifiers, it will have the highest sludge production.
When considering site footprint and aesthetics, the MBR process has the smallest footprint, followed by
the MBBR process. Both the SBR and CAS processes require a fairly large amount of land. The SBR
process is conducted in one tank (although in multiple cells) whereas the CAS process uses different
tanks that are connected via yard piping. The headworks associated with each process has the potential
for odours, but the headworks will be enclosed in a building for all technology options. The primary
clarifiers associated with the CAS process would be located outdoors and may have more potential for
odour generation than the SBR tanks.
HEJV Glace Bay WWTP Preliminary Design Brief 29
4.5.4 Recommended Secondary Treatment Process
Both the life‐cycle cost evaluation, and consideration of other qualitative evaluation factors result in the
SBR process being the recommended secondary treatment process for this facility. This process will
require the acquisition of additional land. The preliminary design has been advanced on the basis of an
SBR process.
HEJV Glace Bay WWTP Preliminary Design Brief 30
CHAPTER 5 PRELIMINARY DESIGN
5.1 Process Description
Preliminary layouts for the proposed treatment system and locations of individual unit processes are
shown in the “Preliminary Design” drawings, found in Appendix C. The processes depicted in these
drawings are consistent with those recommended in the previous chapter of this report. The drawings
contained in the appendix are presented in Table 5.1, below.
Table 5.1 Preliminary Design Drawings
Drawing Number Description
C01 General Arrangement
P01 General Arrangement
P07 Hydraulic Profile and Process Schematic
5.2 Unit Process Descriptions
Drawing C01 in Appendix C includes a site plan showing the location of the proposed new structures.
Further description of the proposed treatment units follows.
5.2.1 Preliminary Treatment
The majority of the influent wastewater will be supplied from a gravity feed to the site where it will
enter a wet well. There will be an overflow from the wet well to the proposed outfall. The influent from
the wet well will be pumped to the WWTP headworks. A separate force main will convey wastewater
from the northeastern portion of the community directly to the WWTP headworks.
Screening
In the WWTP headworks, influent will flow through an escalator fine screen with 6mm perforations. It is
expected that screenings will be washed and dewatered with a Screw Washer Compactor. Dewatered
screenings will be discharged into a bin. Wash water will flow by gravity to the influent channel. The
fine screening system will be installed directly into a channel with a width of approximately 1.6m and a
depth of approximately 2m and will consist of a solids capture screen and a washer/compactor. The
design parameters for fine screening are summarized in the Table 5.2.
HEJV Glace Bay WWTP Preliminary Design Brief 31
Table 5.2 Fine Screening Design Summary
Parameter Design Value
No. of Units 1
Peak Flow (m3/d) 41,445
Channel Width (mm) 1,600
Channel Depth (mm) 2,000
Screen media 6mm perforated
Dewatered Screenings (m3/d) 0.92
Solids Content of Screenings (%) 60
Grit Removal
After screening, influent will pass through a vortex grit chamber (either concrete or stainless steel). Grit
will be pumped from the grit chamber for grit dewatering. Excess water from dewatering will flow back
to the grit chamber inlet channel by gravity. Dewatered grit will be discharged into a bin. After grit
removal, influent will flow to the SBR tanks by gravity.
The grit chamber will be a circular horizontal flow through chamber with a diameter of approximately
4.2m and a depth of approximately 3.55m. The grit well has a depth of 1.83m giving a total depth of
approximately 5.38m. The purpose of the grit chamber is to capture solids such as sand particles with
diameters larger than 0.2 mm. The design parameters for fine screening are summarized in the
Table 5.3.
Table 5.3 Grit Removal Design Summary
Parameter Design Value
No. of Units 1
Peak Flow (m3/d) 41,445
Diameter (m) 4.2
Depth (m) 5.4
Classified Grit Production (m3/d) 0.7
Classified Grit Solids (%) 80
5.2.2 Secondary Treatment
The secondary treatment process will consist of three continuous flow SBR tanks. Pre‐treated
wastewater will flow from the vortex grit chamber to the SBR tanks. Influent weirs distribute the flow
evenly between the three tanks. Influent enters an anoxic pre‐react zone before flowing into the react
zone where aeration takes place. Air is supplied to the SBR tanks by blowers via fine bubble diffusers on
the bottom of the tanks. After the blowers are turned off, settling occurs. After the settling period is
complete, decant begins. Decanted effluent flows by gravity to a UV disinfection unit. An air flow meter
and a dissolved oxygen (DO) probe will be provided for each SBR tank. A pressure transducer and a level
float will also be provided for each tank. The design parameters for secondary treatment are
summarized in the Table 5.4.
HEJV Glace Bay WWTP Preliminary Design Brief 32
Table 5.4 Secondary Treatment Design Summary
Parameter Design Value
Average Flow (m3/d) 13,815
Peak Flow (m3/d) 41,445
No. of Tanks 3
Tank Dimensions (m) 17.5 W x 48 L x 5.5 (plus 1m freeboard)
Total Surface Area (m2) 2,520
Total Volume (m3) 13,860
Ave / Peak HRT (hr) 24 / 8
Cycles per Reactor per Day (average/ peak) 6 / 8
React Time (min) (average/ peak) 120 / 90
Settling Time (min) (average/ peak) 60 / 30
SOR (kg/d) 9,682
Design Air Flow (m3/min) 56
Air Flow per Blower (m3/hr) 3386
Volumetric BOD5 Loading (kg BOD /m³d) 0.1
MLSS (mg/L) 3000
F/M Ratio 0.07
5.2.3 Disinfection
Flows from the SBR system will flow intermittently by gravity to the ultraviolet (UV) disinfection unit
during the decant cycle. Disinfection will be conducted by a UV disinfection unit installed in a single
concrete channel located in the new process building. The channel will be approximately 6.1m long,
1.22m wide, and 2.4m deep. The UV system will consist of two banks of UV lamps. The lamps are
oriented in a staggered inclined array and contain sixteen lamps per bank for a total of thirty‐two (32)
lamps. In order for the decant flow from the SBRs to flow by gravity through the UV system, the UV unit
will likely be installed in the basement of the WWTP. The specified power draw for the system is 33.7
kW. The UV weir height will set the hydraulic grade line for the rest of the treatment process. The
higher high‐water elevation at large tide for Glace Bay was 1.1m geodetic (CGVD28). The estimated
extreme values for 100 year and 50‐year return periods were 2.1m CD geodetic (CGVD28) and 2.0m
geodetic (CGVD28), respectively. In addition, a sea level rise of at least 1.0 m is likely to occur within the
coming century, even if the timeline remains uncertain (CBCL, 2018). Therefore, the UV weir height
must be set at a minimum elevation of 3.1m plus an allowance for head loss. The actual weir height can
be higher than this to accommodate the site grade. The design parameters for the UV disinfection
system are summarized in the Table 5.5.
Table 5.5 UV Disinfection Design Summary
Parameter Design Value
Average Flow (m3/d) 19,958
Peak Flow Capacity (m3/d) 51,784
Number of Reactors (channels) 1
Number of Banks per Reactor 2
Number of Lamp per Bank 16
Total Number of Lamps 32
Effluent TSS (mg/L) <25
Minimum UV Transmission (%UVT) 60
Effluent Fecal Coliforms (MPN / 100 mL) 200
HEJV Glace Bay WWTP Preliminary Design Brief 33
5.2.4 Sludge Management
Sludge must be removed from the treatment system and disposed of at an approved facility. WAS from
the SBR process will have a low solids concentration (less than 1% solids). WAS from the SBR will be
pumped to an aerated sludge holding tank. The aeration will provide mixing of the sludge as well as
further VSS reduction. The sludge holding tank will be sized such that it will provide approximately 9
days of solids retention time (SRT) based on 0.85% solids. The sludge holding tank volume will be
provided in one cell. Supernatant from the aerated sludge tank will be decanted back to the SBRs.
However, minimal thickening of sludge is expected to occur in the sludge tanks. Dewatering of sludge
will be provided with a centrifuge. Design parameters for a centrifuge are provided in Table 5.6.
Table 5.6 Aerated Sludge Holding Tank Design Summary
Parameter Design Value
No. of WAS pumps 3
Daily Sludge Production (kg/d) 1,203
Solids Content (%) 0.85
Daily Sludge Production (m3/d) 141.5
Total Storage Volume (m3) 1238
No. of Cells 1
Tank Dimensions (per cell) (m) 15 x 15 x 5.5
Dewatering
Sludge from the aerated sludge holding tank will be dewatered using a centrifuge. Design parameters
for the centrifuge are provided in Table 5.7.
Table 5.7: Sludge Dewatering Design Summary
Parameter Design Value
Sludge Flow (m3/hr) 33.2
Solids Loading Rate (kg/hr) 281
Polymer Consumption (kg/dry tonne) 12 ‐ 15
Solids Capture (%) > 95
Cake Solids (%) 20
5.3 Facilities Description
The WWTP project will include the following tankage and facilities:
Site access and parking;
Site fencing;
Lift station;
CSO to proposed outfall;
SBR tanks (3);
Aerated sludge holding tank;
Process building;
Admin building;
Sludge building;
Biofilter; and
Yard piping.
The process building will include the following:
Preliminary treatment area with:
o Escalator fine screen with 6mm perforations and screw washer/compactor; and
o Vortex grit chamber with grit dewatering screw.
HEJV Glace Bay WWTP Preliminary Design Brief 34
UV disinfection area;
Blower Room;
Mechanical and Electrical rooms;
Generator; and
Bin room.
The sludge building will include the following:
Centrifuge room;
Electrical room;
Bin room;
Sludge pumps; and
Polymer room.
The Admin building will include the following:
Office space;
Lab;
Control room;
Mechanical room;
Locker room;
Lunch room; and
Washrooms.
5.3.1 Civil and Site Work
Civil and site work will include grading, drainage and site improvements. An access road will be
constructed to provide vehicle access. Security fencing will surround the WWTP.
The Environmental Risk Assessment that was carried out for this system was completed on the basis of a
discharge through an outfall in the receiving environment at a point past the existing breakwater near
the existing GB#8 outfall. The proposed outfall has not been included in this preliminary design as it is
included in the collection system preliminary design. We propose to work with NSE during the next
stage of the project to determine the requirements of the outfall before refining the outfall location /
configuration.
5.3.2 Architectural
The exterior wall system of buildings will be erected of masonry cavity wall construction with
polystyrene cavity insulation. The inner walls will be reinforced concrete bearing block. The exterior
veneer will be face brick similar to the brick of CBRM’s other WWTPs. Interior doors and frames will be
stainless, exterior doors, windows and louvers shall be aluminium, colour anodized to match existing
features. All new buildings will have a hollow core or double tee concrete roofing system.
All required site railings for tanks, walkways, and stairs will be two rail all welded aluminium with a clear
anodized finish.
Interior concrete walls and concrete block walls of the buildings will be painted with an industrial epoxy
coating. Interior metal surfaces will be painted with epoxy coatings and exterior metal will be coated
with an ultraviolet resistant urethane finish. Process area ceilings will be painted. Process area floors
will be concrete, coated with a durable industrial floor coating.
HEJV Glace Bay WWTP Preliminary Design Brief 35
5.3.3 Mechanical
Mechanical systems will be designed in accordance with NFPA 820, 2016 edition, which describes the
hazard classification of specific areas and processes and prescribes ventilation criteria for those areas.
Table 5.8 summarizes the proposed classification for new facilities.
Table 5.8: Classification of Building Areas
Location Classification
Preliminary Treatment Room Class 1 Zone 1
Mechanical and Electrical Room Unclassified
UV Room Unclassified
Blower Room Unclassified
Solids Handling Room Class 1 Zone 2
Admin Building Unclassified
Heating will be provided by electric unit heaters and electric duct heaters in central air handling units.
5.3.4 Electrical
Three‐phase electrical service is available on Bell Street and will be extended to the site. An emergency
generator will be located in the Process Building.
5.3.5 Lighting
Exterior lighting will consist of building mounted luminaires illuminating areas immediately adjacent the
buildings, as well as pole mounted area lighting for access roadways and parking areas. Exterior lights
will be LED where available or to suit application. Exterior lighting fixtures shall be vandal resistant and
outdoor rated.
New pole mounted flood lights will be installed at the process tanks for maintenance purposes.
The interior lighting system will be designed for lighting performance and illuminance levels in
accordance with the Illuminating Engineering Society (IESNA) Lighting Handbook, 10th Edition. Interior
lights will be fluorescent, LED or metal halide to suit the application.
Emergency and exit lights will be installed along egress routing and around exit doors to meet the
requirements of the National and Provincial Building Codes.
5.3.6 Instrumentation
This section summarizes the functional requirements for the process control and instrumentation
system. It includes a narrative description of the instrumentation and control requirements.
Most unit processes in the treatment plant will be automated. There will be a main plant PLC that will
be used to control many of the unit processes. In addition to the main PLC, a local hand‐off‐auto
(H‐O‐A) switch will be required for most of the equipment. Some of the more complex unit processes
will be provided with their own individual PLCs including:
UV disinfection system;
SBRs;
Blowers;
Generator; and
Centrifuge.
Each piece of equipment that is to be provided with a dedicated controller will be capable of operating
in either a manual or automatic mode (SCADA controlled) via an H‐O‐A switch.
HEJV Glace Bay WWTP Preliminary Design Brief 36
Overview
Unit operations at the treatment plant will be monitored and controlled using a system of instruments,
equipment motors, PLCs, human machine interfaces (HMI), communications cable, and hardware that is
integrated into a SCADA software program. The selection of Supervisory and Control Software as well as
the level one type of plant instrumentation will be made following the selection of a system integrator
and a review of options by plant operating personnel and the engineers.
The system will also be configured to allow an authorized operator to dial in and log on from a remote
location via laptop from their home. This will permit the Supervisor or duty operator to check plant
status, respond to after‐hours alarms, and to change equipment operation where appropriate.
In addition to the aforementioned monitoring and control terminals, there will be local control panels at
key locations using “soft panel” type HMIs (human/machine interface), which will permit the operator to
view process information and to take local control action. In some locations, where the only
requirement is to be able to stop a motor and to lock it out for maintenance, that capability will be
provided by hard‐wired controls at the motor starter.
The alarms integrated into the system will have audible and/or flashing light annunciation in the plant
during regular hours, and call‐out by telephone and/or email after hours with a user‐configurable
sequential call priority list.
Headworks
The Headworks consist of fine screening and a vortex grit chamber. All the equipment will be controlled
by the main PLC. Each piece of equipment will be monitored for status and faults in addition to the
alarms for high and low levels in the influent channels which will be registered on the central control
computers and monitors.
SBR System
Effluent from preliminary treatment will be split between the SBR tanks via weirs.
The SBR and sludge blowers will be installed in the Process Building. The SBR blowers will discharge to a
common air header which will have a dedicated take off for each SBR. Blower operation will be
controlled by the SBR control system. The digester blower will discharge to a common air header which
will have a dedicated take off for each sludge holding tank cell.
The air headers will feed the fine bubble diffusers arranged along the bottom of the SBRs. A separate
header will feed the fine bubble diffusers arranged along the bottom of the aerated sludge holding
tanks. Dissolved oxygen will be monitored in the SBR tanks.
An air flow meter in the supply header will indicate, totalize, and record the air flow to the plant. The
dissolved oxygen levels for each reactor will be indicated and recorded on the central SCADA system.
Blower operating status, header pressure and inlet valve positions as well as supply line pressure will be
indicated on the central computer system. The blowers will also be equipped with sensors and alarms
for surge, vibration, temperature, and general faults, which will register at the central control.
Effluent will be removed from the SBR tanks via a solids excluding decanter. Flow through the decanter
will be automatically controlled via a valve by the SBR control system.
Waste Activated Sludge
HEJV Glace Bay WWTP Preliminary Design Brief 37
The WAS will be pumped from the SBRs to the aerated sludge holding tanks automatically using WAS
pumps which will be controlled by the SBR control system. WAS flow will be measured by magnetic flow
meters installed on the suction side of the pumps.
Effluent Disinfection
Ultraviolet Disinfection will be used to achieve disinfection limits for fecal coliform prior to discharge.
The UV manufacturer will provide a PLC to control the UV system. The UV PLC will be compatible with
the central station. UV dose will be controlled by plant flow and percent UVT. Monitoring and
recording of UV intensity, general alarms, and low level, high levels alarms will be provided. Automatic
wiping will be controlled on timer or by monitoring UV intensity.
Centrifuge
The sludge feed rate to the centrifuge equipment will be set to maintain the sludge inventory in the
holding tanks within a set band. The centrifuge PLC communicates with the sludge feed pumps and
polymer make‐down system and adjusts sludge feed and polymer dosing pump rates to suit the
centrifuge throughput.
HEJV Glace Bay WWTP Preliminary Design Brief 38
CHAPTER 6 PROJECT COSTS
6.1 Opinion of Probable Capital Costs
An opinion of probable capital cost for the recommended treatment process option is presented in
Table 6.1, on the following page. Please note that the costs of interception and pumping are extra and
are detailed in a separate pre‐design brief.
6.2 Opinion of Annual Operating Costs
An annual operating cost estimate for the recommended treatment process option is presented in Table
6.2.
Table 6.2: Annual Operating Cost Estimate
Category Annual Operation Cost
Staffing $500,000
Power $270,000
Chemicals $33,000
Sludge Disposal $220,000
Maintenance Allowance $47,000
Total $1,070,000
6.3 Opinion of Annual Capital Replacement Fund Contributions
The CBRM wishes to create a Capital Replacement Fund to which annual contributions would be made
to prepare for replacement of the wastewater assets at the end of their useful life. The calculation of
annual contributions to this fund involves consideration of such factors as the type of asset, the asset
value, the expected useful life of the asset, and the corresponding annual depreciation rate for the
asset, as per the accounting practices for asset depreciation and Depreciation Funds recommended in
the Water Utility Accounting and Reporting Handbook (Nova Scotia Utility and Review Board, 2013). In
consideration of these factors, Table 6.3 provides an estimation of the annual contributions to a capital
replacement fund for the proposed new wastewater treatment system infrastructure. This calculation
also adds the same contingency factors used in the calculation of the Opinion of Probable Capital Cost,
to provide an allowance for changes during the design and construction period of the WWTP. The actual
Annual Capital Replacement Fund Contributions will be calculated based on the final constructed asset
value, the type of asset, the expected useful life of the asset, and the corresponding annual depreciation
rate for the asset type.
Project Manager: D. McLean
Est. by: P. Gerry Checked by: A Thibault
PROJECT No.: 187116 (Dillon)
182402.00 (CBCL)
UPDATED: July 2, 2020
1.04
1.0 3,145,000$
allow 1 600,601$ 601,000$
allow 10%2,544,000$
2.0 3,585,289$
m2 11,000 5$ 55,000$
m3 excavated 29,300 20$ 586,000$
m3 excavated 6,500 50$ 325,000$
m3 2,200 42$ 91,520$
tonne 465 200$ 93,000$
tonne 600 25$ 15,000$
tonne 1,100 22$ 24,200$
Armour Stone m3 1,050 100$ 105,000$ m 120 100$ 12,000$ 1200 mm dia sanitary sewer m 180 2,300$ 414,000$ 600 mm dia sanitary pipe m 120 725$ 87,000$
m 100 350$ 35,000$
m 115 725$ 83,369$
m 200 100$ 20,000$
ea.3 10,000$ 30,000$
ea.5 45,000$ 225,000$
ea.1 25,000$ 25,000$
m 410 100$ 41,000$
allow 1 14,440$ 14,440$
SSP Cofferdam m2 876 900$ 788,760$
allow 1 500,000$ 500,000$ allow 1 15,000$ 15,000$
3.0 7,641,317$
m3 of baseslab 408 728$ 297,024$
m3 of baseslab 2,670 1,000$ 2,670,000$
m3 of concrete 1,334 1,000$ 1,334,000$
m3 of concrete 1,853 1,600$ 2,964,800$
m2 of concrete 70 174$ 12,202$
allow 5%363,291.20$
4.0 471,204$
m2 wall area 459 226$ 103,743$
m2 wall area 794 463$ 367,460$
5.0 705,604$
m2 building area 1,517 104$ 157,761$
m2 building area 837 450$ 376,862$
m2 building area 837 174$ 145,981$
allow 25,000$
6.0 508,113$
m2 building area 837 118$ 99,123$
m2 building area 837 107$ 89,609$
m2 building area 837 25$ 20,937$
m2 building area 837 107$ 89,609$
m2 building area 837 30$ 25,124$
each 26 2,650$ 68,900$
each 20 1,100$ 22,000$
each 2 8,000$ 16,000$
each 4 3,500$ 14,000$
m2 building area 837 75$ 62,810$
7.0 4,651,400$
each 1 767,000$ 767,000$
each 1 302,640$ 302,640$
each 1 404,560$ 404,560$ each 1 1,768,000$ 1,768,000$ each 1 452,400$ 452,400$
allow 1 436,800$ 436,800$
allow 1 520,000$ 520,000$
8.0 3,865,659$
m2 building area 837 728$ 609,679$
allow 30% of equipment 1,395,420$
allow 40% of equipment 1,860,560$
9.0 4,007,146$
allow 15% of project cost 3,214,288$ allow 3% of project cost 642,858$ allow 150,000$
28,581,000$
A 25%7,200,000$ B 12%3,500,000$
C Inflation (Based on 2020 Dollars) - Note 3 Not included
D Location Factor - Note 4 Included in Units
E 200,000$
39,481,000$
15%5,922,000$
45,403,000$
THIS OPINION OF PROBABLE COSTS IS PRESENTED ON THE BASIS OF EXPERIENCE, QUALIFICATIONS, AND BEST JUDGEMENT. IT HAS BEEN PREPARED IN ACCORDANCE
WITH ACCEPTABLE PRINCIPLES AND PRACTICES. MARKET TRENDS, NON-COMPETITIVE BIDDING SITUATIONS, UNFORSEEN LABOUR AND MATERIAL ADJUSTMENTS AND
THE LIKE ARE BEYOND THE CONTROL OF HEJV. AS SUCH WE CANNOT WARRANT OR GUARANTEE THAT ACTUAL COSTS WILL NOT VARY FROM THE OPINION PROVIDED.
TOTAL CONSTRUCTION & DESIGN COST without HST
Taxes (HST)
TOTAL CONSTRUCTION & DESIGN COST with HST
Construction ContingencyEngineering
Land Purchase
TOTAL DIRECT & INDIRECT CONSTRUCTION COST (Exluding Contingencies and Allowances)
CONTINGENCIES and ALLOWANCES
Process Installation
Electrical
Power Supply & Distribution
Instrumentation & Control
Generator
Sludge Dewatering
Odour Control
MechanicalHVAC and Plumbing Process Mechanical
Process Equipment Supply
Fine Screening
Grit Removal
SBR Equipment
UV Disinfection System
Floor Finishes (Lab, Office, Admin Area)
Windows (exterior - single)
Doors (single swing steel)
Overhead rolling door (3m wide)Double swing FRP doorsOther Interior Finishes, Misc
Pump Station Equipment
Finishes/Doors/Windows
Carpentry, Assessories and Fixtures
Louvers
Painting
Epoxy Coating
Metal Railings, Stairs, Grating, Hatches
Beams and ColumnsRoof (12" hollowcore concrete panels)Miscellaneous Metals Items
Masonry
Interior Masonry c/w Grout & Rebar
Exterior Masonry
Metals & Roofing
Baseslabs (tanks)
Foundation and Exterior Building Walls
Foundations and Tank Walls
2nd flr hollowcore slab
Miscellaneous Concrete Items
Baseslabs (building)
Excavation - rock
General Conditions
ITEM / No. DESCRIPTION UNIT EST. QUANTITY UNIT COST Total
Sediment Control
Dewatering
Reinstatement
Concrete
2400 dia Valve Chamber x 3m Deep
Chainlink Fence and Gates
Excavation
Gravel (beneath slabs)
Table 6.1
PREPARED FOR:OPINION OF PROBABLE COST, CLASS 'C'
Preliminary
Cape Breton Regional Municipality
Wastewater Treatment System Costs Only
Glace Bay, NS
Manholes - 3000 mm dia sanitary
Mobilization, Bonds, Insurance, P.C. Mngmt
Contractor Overhead & Fees
Site Works
Site Preparation
150 mm dia D.I. Piping
600 mm dia Concrete Cl 65 Storm sewer
DitchingManholes
Asphalt
Type 1 (150mm)
Type 2 (300mm)
Curb
March 27, 2020
HEJV Glace Bay WWTP Preliminary Design Brief 39
Table 6.3: Annual Capital Replacement Fund Contributions
Description of Asset Asset Value
Asset Useful
Life Expectancy
(Years)
Annual
Depreciation
Rate (%)
Annual Capital
Replacement Fund
Contribution
Treatment Linear Assets (Yard
Piping, Manholes and Other) $3,080,366 75 1.3% $41,000
Treatment Structures (Concrete
Chambers, etc.) $11,461,000 50 2.0% $229,000
Treatment Equipment (Mechanical /
Electrical, etc.) $14,039,634 20 5.0% $702,000
Subtotal $28,581,000 ‐ ‐ $972,000
Construction Contingency (Subtotal x 25%): $243,000
Engineering (Subtotal x 12%): $117,000
Opinion of Probable Annual Capital Replacement Fund Contribution: $1,332,000
Table Notes
1 ‐ Costs do not account for annual inflation
2 ‐ Costs do not include applicable taxes.
HEJV Appendices
APPENDIX A
Flow Meter Data
HEJV Appendices
APPENDIX B
Environmental Risk Assessment
182402.00 ● Report ● June 2020
Glace Bay Wastewater Treatment Plant
Environmental Risk Assessment
Final Report
Prepared by:
Prepared for:
March 2020
Final June 9, 2020 Darrin McLean Karen March Holly Sampson
Revised Draft – Revision 1 January 7, 2019 Darrin McLean Karen March Holly Sampson
Draft for Review August 29, 2018 Darrin McLean Karen March Holly Sampson
Issue or Revision Date Issued By: Reviewed By: Prepared By:
This document was prepared for the party indicated
herein. The material and information in the
document reflects HE’s opinion and best judgment
based on the information available at the time of
preparation. Any use of this document or reliance
on its content by third parties is the responsibility of
the third party. HE accepts no responsibility for any
damages suffered as a result of third party use of
this document.
182402.00
March 27, 2020
182402 RE 001 DRAFT WWTP ERA GLACE BAY_FINAL.DOCX/mk
ED: 09/06/2020 12:54:00/PD: 09/06/2020 12:55:00
June 9, 2020
Matt Viva, P.Eng.
Manager Wastewater Operations
Cape Breton Regional Municipality (CBRM)
320 Esplanade,
Sydney, NS B1P 7B9
Dear Mr. Viva:
RE: Glace Bay Wastewater Treatment Plant ERA
Enclosed, please find a copy of the Environmental Risk Assessment (ERA) Report
for the Glace Bay Wastewater Treatment Plant (WWTP).
The report outlines Environmental Quality Objectives (EQOs) for all parameters
of potential concern listed in the Standard Method for a “medium” facility that
were detected in the effluent. Environmental Discharge Objectives (EDOs) were
also calculated for all parameters of potential concern that were detected in the
effluent and for which an Environmental Quality Objective (EQO) was identified.
If you have any questions or require clarification on the content presented in
the attached report, please do not hesitate to contact us.
Yours very truly,
Harbour Engineering
Prepared by: Reviewed by:
Holly Sampson, M.A.Sc., P.Eng. Karen March, M.Sc.
Intermediate Chemical Engineer Environmental Scientist
Direct: 902‐539‐1330 Phone: 902‐450‐4000
E‐Mail: hsampson@cbcl.ca E‐Mail: kmarch@dillon.ca
Project No: 182402.00 (CBCL)
187116.00 (Dillon)
March 27, 2020
Harbour Engineering Joint Venture Glace Bay WWTP ERA i
Contents
CHAPTER 1 Background and Objectives ................................................................................... 1
1.1 Introduction .................................................................................................................. 1
1.2 Background ................................................................................................................... 1
1.3 Facility Description ........................................................................................................ 2
CHAPTER 2 Initial Effluent Characterization ............................................................................. 5
2.1 Substances of Potential Concern .................................................................................. 5
2.1.1 Whole Effluent Toxicity ..................................................................................... 7
2.2 Wastewater Characterization Results .......................................................................... 7
CHAPTER 3 Environmental Quality Objectives ....................................................................... 12
3.1 Water Uses .................................................................................................................. 12
3.2 Ambient Water Quality ............................................................................................... 13
3.3 Physical/ Chemical/ Pathogenic Approach ................................................................. 19
3.3.1 General Chemistry/ Nutrients ........................................................................ 19
3.3.2 Metals ............................................................................................................. 24
3.3.3 E. coli ............................................................................................................... 26
3.3.4 Summary ......................................................................................................... 28
CHAPTER 4 Mixing Zone Analysis ........................................................................................... 30
4.1 Methodology ............................................................................................................... 30
4.1.1 Definition of Mixing Zone ............................................................................... 30
4.1.2 Site Summary .................................................................................................. 32
4.1.3 Far‐Field Modeling Approach and Inputs ....................................................... 32
4.1.4 Modeled Effluent Dilution .............................................................................. 35
CHAPTER 5 Effluent Discharge Objectives .............................................................................. 41
5.1 The Need for EDOs ...................................................................................................... 41
5.2 Physical/ Chemical/ Pathogenic EDOs ........................................................................ 41
5.3 Effluent Discharge Objectives ..................................................................................... 42
CHAPTER 6 Compliance Monitoring ....................................................................................... 45
CHAPTER 7 References .......................................................................................................... 46
Appendices
A Laboratory Certificates
Harbour Engineering Joint Venture Glace Bay WWTP ERA 1
CHAPTER 1 BACKGROUND AND OBJECTIVES
1.1 Introduction
Harbour Engineering (HE) was engaged by the Cape Breton Regional Municipality (CBRM) to complete
an Environmental Risk Assessment (ERA) for the proposed Glace Bay Wastewater Treatment Plant
(WWTP). As this is a proposed WWTP that has not yet been designed, this ERA was completed with the
objective that it serve as a tool to establish effluent criteria for the design of a new WWTP. For this
reason, the ERA was completed without the frequency of testing required by the Standard Method
outlined in Technical Supplement 3 of the Canada‐wide Strategy for the Management of Municipal
Wastewater Effluent (Standard Method) for initial effluent characterization. With the exception of the
initial effluent characterization sampling frequency, the ERA was otherwise completed in accordance
with the Standard Method.
1.2 Background
The Canada‐wide Strategy (CWS) for the Management of Municipal Wastewater Effluent was adopted
by the Canadian Council of Ministers of the Environment (CCME) in 2009. The Strategy is focused on
two (2) main outcomes: Improved human health and environmental protection; and improved clarity
about the way municipal wastewater effluent is managed and regulated. The Strategy requires that all
wastewater facilities discharging effluent to surface water meet the following National Performance
Standards (NPS) as a minimum:
Carbonaceous Biochemical Oxygen Demand for five days (CBOD5) – 25 mg/L;
Total Suspended Solids (TSS) – 25 mg/L; and
Total Residual Chlorine (TRC) – 0.02 mg/L.
The Wastewater Systems Effluent Regulations (WSER) came into effect in 2012 under the Fisheries Act.
The WSER include the above NPS as well as the following criteria:
Unionized ammonia ‐ 1.25 mg/L, expressed as nitrogen (N), at 15°C ± 1°C.
The CWS requires that facilities develop site‐specific Environmental Discharge Objectives (EDOs) to
address substances not included in the NPS that are present in the effluent. EDOs are the substance
concentrations that can be discharged in the effluent and still provide adequate protection of human
health and the environment. They are established by conducting a site‐specific ERA. The ERA includes
characterization of the effluent to determine potential substances of concern, and characterization of
the receiving water to determine beneficial water uses, ambient water quality, assimilative capacity, and
Harbour Engineering Joint Venture Glace Bay WWTP ERA 2
available dilution. A compliance monitoring program is then developed and implemented to ensure
adherence to the established EDOs for the facility.
1.3 Facility Description
The proposed Glace Bay Wastewater Treatment Plant (WWTP) will be constructed at Lower Main
Street near Glace Bay Harbour. Treated effluent will be discharged to the Atlantic Ocean at the
location of the existing outfall near the breakwater (Figure 1.2).
Figure 1.1 Site Location
Harbour Engineering Joint Venture Glace Bay WWTP ERA 3
Figure 1.2 WWTP Location
The service population of Glace Bay is 14,536 people in 7,258 residential units. The theoretical
domestic wastewater flow (exclusive of inflow and infiltration (I&I)) is an average of 4,942 m3/day
with a peak of 13,838 m3/day based on a per capita flow of 340 L/person/day and a peaking factor
of 2.8 calculated using the Harmon formula.
There are currently 8 existing outfalls (see Figure 3.1). These outfalls will be consolidated into one
discharge at the location of existing GB‐8 outfall. The estimated service population associated with
each outfall, based on 2016 census data, is provided in Table 1.1:
Table 1.1 Service Population by Outfall
Outfall Name Residential Units Population
GB1 253 558
GB2 231 504
GB3 21 44
GB4A 306 590
GB4B 36 77
GB5 57 118
GB6 347 713
GB7 72 140
GB8 5935 11791
Total 7258 14536
Harbour Engineering Joint Venture Glace Bay WWTP ERA 4
For the purpose of the ERA, the average daily flow was assumed to be 14,200 m3/day (215 IG/p/day
or 1m3/p/day) for modelling purposes, based on a reasonable per capita allowance for average
annual flow. The preliminary design of the proposed WWTP was subsequently completed based on
an average design flow of 13,815 m3/day. The effluent modelling will not be updated at this time.
See the WWTP preliminary design report for information on the development of design flows. The
design flows do not account for growth. CBRM has a declining population so increased flows due to
population growth are not expected. CBRM’s wastewater collection systems have significant inflow
and infiltration (I&I), and CBRM plans to implement an I&I reduction program.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 5
CHAPTER 2 INITIAL EFFLUENT CHARACTERIZATION
2.1 Substances of Potential Concern
An initial characterization program covering a one‐year period is typically required by the Standard
Method to describe the treated effluent and identify substances of concern. As there is no existing
WWTP for this system, and the ERA is being conducted for the purpose of determining effluent
objectives for the design of a new WWTP, one sample event was completed for each of the existing
8 outfalls. Sample results for some of the parameters of potential concern were also available from
three‐years of sampling conducted by CBRM from 2015 through 2017 at the GB4 outfall, one sample
collected by Dillon Consulting in 2014 at each of the outfalls, and samples collected by UMA
Engineering in 1992 at the Park Street sewer. Substances of potential concern are listed in the
Standard Method based on the size category of the facility. The proposed design capacity of the new
WWTP will be finalized during the pre‐design study, but for the purposes of the draft ERA, an
average annual flow of 14,200 m3/day will be assumed based on a per capita flow of 215 IG/p/day
(1m3/p/day). Therefore, the WWTP is classified as a “medium” facility based on an average daily
flow rate that is between 2,500 and 17,500 m3/day.
The substances of potential concern for a “medium” facility, as per the Standard Method, are
detailed in Table 2.1. There were no additional substances of concern identified to be monitored as
industrial input does not exceed 5% of total dry weather flow in the sewer shed, on an annual
average basis. There is one hospital and a fish processing plant, but the flows are expected to be
much less than 5% of the wastewater flow for the system.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 6
Table 2.1 – Substances of Potential Concern for a Medium Facility
Test Group Substances
General Chemistry
/ Nutrients
Fluoride
Nitrate
Nitrate + Nitrite
Total Ammonia Nitrogen
Total Kjeldahl Nitrogen (TKN)
Total Phosphorus (TP)
Total Suspended Solids (TSS)
Carbonaceous Biochemical Oxygen Demand (CBOD5)
Total Residual Chlorine (TRC)
Chemical Oxygen Demand (COD)
Cyanide (total)
pH
Temperature
Metals
Aluminum, barium, beryllium, boron, cadmium, chromium, cobalt, copper, iron,
lead, manganese, molybdenum, nickel, silver, strontium, thallium, tin, titanium,
uranium, vanadium, zinc as well as arsenic, antimony, selenium and mercury
Pathogens E. coli (or other pathogen, as directed by the jurisdiction)
Organochlorine
Pesticides
Alpha‐BHC, endosulfin (I and II), endrin, heptachlor epoxide, lindane (gamma‐
BHC), mirex, DDT, methoxychlor, aldrin, dieldrin, heptachlor, a‐chlordane and g‐
chlordane, toxaphene
Polychlorinated
Biphenyls (PCBs) Total PCBs
Polycyclic Aromatic
Hydrocarbons
(PAHs)
Acenaphthene, acenapthylene, anthracene, benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene, benzo(g,h,i)perylene,
benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, fluorene,
indeno(1,2,3‐cd)pyrene, methylnaphthalene, naphthalene, phenanthrene, pyrene
Volatile Organic
Compounds (VOCs)
Benzene, bromodichloromethane, bromoform, carbon tetrachloride,
chlorobenzene, chlorodibromomethane, chloroform, 1,2‐dichlorobenzene, 1,4‐
dichlorobenzene, 1,2‐dichloroethane, 1,1‐dichloroethene, dichloromethane,
ethylbenzene, 1,1,1,2‐tetrachloroethane, 1,1,2,2‐tetrachloroethane,
tetrachloroethene, toluene, trichloroethene, vinyl chloride, m/p‐xylene, o‐xylene
Phenolic
Compounds
2,3,4,6‐tetrachlorophenol, 2,4,6‐trichlorophenol, 2,4‐dichlorophenol,
pentachlorophenol
Surfactants Non‐ionic surfactants and anionic surfactants (others may be added by the
jurisdiction)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 7
2.1.1 Whole Effluent Toxicity
Wastewater effluent potentially contains a variety of unknown or unidentified substances for which
guidelines do not exist. In order to adequately protect against these unknown substances, Whole
Effluent Toxicity (WET) tests are typically conducted to evaluate acute (short‐term) and chronic (long‐
term) effects.
The Standard Method requires the following toxicity tests be conducted quarterly:
Acute toxicity – Rainbow Trout and Daphnia magna; and
Chronic Toxicity – Ceriodaphnia dubia and Fathead Minnow.
A draft for discussion Mixing Zone Assessment and Report Template, dated July 6, 2016 that was
prepared by a committee of representatives of the environment departments in Atlantic Canada noted
that only Ceriodaphnia dubia testing is required for chronic toxicity. If the test does not pass, a fathead
minnow test is required.
As the wastewater in this system is currently untreated, and the purpose of the ERA is to determine
effluent discharge objectives for the design of a new WWTP, no WET tests were conducted at this time.
2.2 Wastewater Characterization Results
The results of the initial wastewater characterization program completed by HE are summarized in
Tables 2.2 through 2.6. One sample was collected for each outfall in the system as part of the initial
wastewater characterization study. Outfall locations are shown in Section 3.
Table 2.2 – Initial Wastewater Characterization Results – General Chemistry
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
CBOD5 (mg/L) 32 50 130 84 54 30 64
COD (mg/L) 53 100 200 120 130 41 120
Total NH3‐N (mg/L) 1.4 2.0 3.4 3.8 2.1 0.51 3.7
TSS (mg/L) 25 53 49 41 40 15 50
TP (mg/L) 0.69 0.99 2.2 1.6 1.0 0.3 1.8
TKN (mg/L) 6.0 6.8 16 12 9.2 2.2 13
pH 7.11 7.00 6.79 6.52 7.17 7.18 7.31
Un‐ionized NH3 (mg/L)(1) 0.0049 0.0055 0.0058 0.0035 0.0085 0.0021 0.0207
E. coli (MPN/100mL) 77000 >240000 >240000 130000 >240000 170000 >240000
Fluoride (mg/L) <0.10 <0.10 0.12 0.1 0.12 <0.10 0.11
Nitrate (mg/L) 0.67 0.079 <0.050 0.08 0.79 1.0 <0.050
Nitrite (mg/L) 0.03 0.34 <0.010 0.83 0.06 0.025 <0.010
Nitrate + Nitrite (mg/L) 0.69 0.42 <0.050 0.91 0.85 1.0 <0.050
Total Nitrogen (TN) (mg/L) 6.7 7.2 16.0 12.9 10.1 3.2 13.0
Total Cyanide (mg/L) 0.0019 0.0022 0.0028 0.0034 0.0029 0.0015 0.013
Note:
(1) The values of unionized ammonia were determined in accordance with the formula in the WSER, the
concentration of total ammonia in the sample, and the pH of the sample.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 8
Table 2.3 – Initial Wastewater Characterization Results – Metals (mg/L)
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
Aluminum 0.077 0.31 0.28 0.66 0.14 0.06 0.11
Antimony <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Arsenic <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Barium 0.045 0.03 0.033 0.031 0.044 0.038 0.037
Beryllium <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Boron <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050
Cadmium 0.000038 0.00017 0.00031 0.00036 0.00013 0.00004 0.000095
Chromium <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Cobalt <0.00040 0.0012 0.0011 0.0025 0.00065 <0.00040 <0.00040
Copper 0.0047 0.0068 0.01 0.015 0.009 0.0044 0.0099
Iron 0.17 1 0.42 0.58 0.19 0.3 0.49
Lead <0.00050 0.00062 0.001 0.0029 0.00051 0.00056 0.00057
Manganese 0.12 0.75 0.4 0.56 0.32 0.29 0.25
Molybdenum <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 0.0065 <0.0020
Nickel <0.0020 0.004 0.0066 0.011 0.0031 <0.0020 <0.0020
Selenium <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Silver <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010
Strontium 0.16 0.12 0.12 0.16 0.13 0.28 0.11
Thallium <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010
Tin <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
Titanium 0.003 0.0052 0.0082 <0.020 <0.020 0.0032 0.0029
Uranium 0.00017 0.00011 <0.00010 <0.00010 0.00011 0.00015 <0.00010
Vanadium <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
Zinc 0.015 0.051 0.11 0.11 0.043 0.013 0.040
Mercury <0.000013 <0.000013 <0.000013 <0.000013 0.000013 <0.000013 <0.000013
Harbour Engineering Joint Venture Glace Bay WWTP ERA 9
Table 2.4 – Initial Wastewater Characterization Results – VOCs (µg/L)
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
1,2‐Dichlorobenzene <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
1,4‐Dichlorobenzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Chlorobenzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
1,1,2,2‐Tetrachloroethane <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
1,1‐Dichloroethylene <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
1,2‐Dichloroethane <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Benzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Bromodichloromethane <1.0 1.0 1.0 1.2 1.0 <1.0 <1.0
Bromoform <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Carbon Tetrachloride <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
Chloroform 2.4 3.8 4.1 5 3.8 <1.0 3.1
Dibromochloromethane <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Ethylbenzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Methylene Chloride
(Dichloromethane) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0
o‐xylene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
m/p‐xylene <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0
Tetrachloroethene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Toluene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.3
Trichloroethene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Vinyl Chloride <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
Harbour Engineering Joint Venture Glace Bay WWTP ERA 10
Table 2.5 – Initial Wastewater Characterization Results – PCBs, Phenols, PAHs
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
Total PCBs (µg/L) <0.05 <0.05 <0.3 <0.05 <0.05 <0.05 <0.05
Phenols (mg/L) 0.0051 0.0049 0.013 0.0081 0.017 0.0015 0.0011
1‐Methylnaphthalene (µg/L) <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050
2‐Methylnaphthalene (µg/L) <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050
Acenaphthene (µg/L) <0.010 <0.010 <0.050 0.015 <0.010 <0.010 <0.010
Acenaphthylene (µg/L) <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010
Anthracene (µg/L) <0.010 <0.010 <0.010 0.037 <0.010 <0.010 <0.010
Benzo(a)anthracene (µg/L) <0.010 <0.010 <0.010 0.09 <0.010 <0.010 <0.010
Benzo(a)pyrene (µg/L) <0.010 <0.010 <0.010 0.064 <0.010 <0.010 <0.010
Benzo(b)fluoranthene (µg/L) <0.010 <0.010 <0.010 0.054 <0.010 <0.010 <0.010
Benzo(g,h,i)perylene (µg/L) <0.010 <0.010 <0.010 0.04 <0.010 <0.010 <0.010
Benzo(k)fluoranthene (µg/L) <0.010 <0.010 <0.010 0.026 <0.010 <0.010 <0.010
Chrysene (µg/L) <0.010 <0.010 <0.010 0.073 <0.010 <0.010 <0.010
Dibenz(a,h)anthracene (µg/L) <0.010 <0.010 <0.010 0.021 <0.010 <0.010 <0.010
Fluoranthene (µg/L) 0.013 0.017 0.016 0.21 <0.010 <0.010 <0.010
Fluorene (µg/L) <0.010 <0.010 <0.010 0.02 <0.010 <0.010 <0.010
Indeno(1,2,3‐cd)pyrene (µg/L) <0.010 <0.010 <0.010 0.041 <0.010 <0.010 <0.010
Naphthalene (µg/L) <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20
Phenanthrene (µg/L) 0.016 0.031 0.031 0.12 0.016 <0.010 0.011
Pyrene (µg/L) 0.011 0.016 0.016 0.16 <0.010 <0.010 <0.010
Table 2.6 – Initial Wastewater Characterization Results – Organochlorine Pesticides (µg/L)
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
Aldrin <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Dieldrin <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
a‐Chlordane <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
g‐Chlordane <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
o,p‐DDT <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
p,p‐DDT <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Lindane <0.003 <0.003 <0.02 <0.003 <0.003 <0.003 <0.003
Endosulfan I (alpha) <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Endosulfan II (beta) <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Endrin <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Heptachlor <0.006 <0.005 <0.03 <0.02 <0.02 <0.005 <0.005
Heptachlor epoxide <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Methoxychlor <0.01 <0.01 <0.07 <0.01 <0.01 <0.01 <0.01
alpha‐BHC <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Mirex <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Toxaphene <0.2 <0.2 <1 <0.2 <0.2 <0.2 <0.2
DDT+ Metabolites <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Harbour Engineering Joint Venture Glace Bay WWTP ERA 11
Table 2.7 – Historical Wastewater Characterization Samples
Location Parameter Average Number of Samples
GB1
TSS (mg/L) 31 1
CBOD5 (mg/L) 48 1
Unionized Ammonia (mg/L) 0.023 1
GB2
TSS (mg/L) 55 1
CBOD5 (mg/L) 53 1
Unionized Ammonia (mg/L) 0.027 1
GB3
TSS (mg/L) 59 1
CBOD5 (mg/L) 290 1
Unionized Ammonia (mg/L) 0.330 1
GB4
TSS (mg/L) 394 27
CBOD5 (mg/L) 40 27
Total Ammonia (mg/L) 0.3 12
pH 7.4 12
Unionized Ammonia (mg/L) 0.004 13
GB5
TSS (mg/L) 110 1
CBOD5 (mg/L) 56 1
Unionized Ammonia (mg/L) 0.011 1
GB6
TSS (mg/L) 81 1
CBOD5 (mg/L) 240 1
Unionized Ammonia (mg/L) 0.009 1
GB7
TSS (mg/L) 40 1
CBOD5 (mg/L) 55 1
Unionized Ammonia (mg/L) 0.003 1
GB8
TSS (mg/L) 129 18
CBOD5 (mg/L) 105 18
Unionized Ammonia (mg/L) 0.006 1
GB8A
TSS (mg/L) 90 24
CBOD5 (mg/L) 76 24
pH 7.1 24
Alkalinity (mg/L) 100 4
TKN (mg/L) 23.9 4
Total Phosphorus (mg/L) 2.40 4
Note: Location GB8A is a sample location upstream of the GB8 outfall at Park St.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 12
CHAPTER 3 ENVIRONMENTAL QUALITY OBJECTIVES
Generic Environmental Quality Objectives (EQOs) are generated from established guidelines, typically
the Wastewater Systems Effluent Regulations (WSER), the Canadian Environmental Quality Guidelines
(CEQGs) and other guidelines specified by jurisdiction. Site‐specific EQOs are established by adjusting
the generic EQOs based on site‐specific factors, particularly ambient water quality. For example, if the
background concentration of a substance is greater than the guideline value (generic EQO), the
background concentration is used as the site‐specific EQO. However, substances where the EQO is based
on the WSER are not adjusted based on ambient water quality. Furthermore, there are some guidelines
that are dependent on characteristics of the receiving water like pH or temperature.
EQOs can be determined by three different approaches:
Physical/ chemical/ pathogenic – describes the substance levels that will protect water quality;
Whole Effluent Toxicity (WET) – describes the proportion of effluent that can enter the receiving
water without causing toxicological effects (both acute and chronic); and
Biological criteria (bio‐assessment) – describes the level of ecological integrity that must be
maintained.
This assessment follows the physical/ chemical/ pathogenic approach from the Standard Method
outlined in the CCME guidelines. The bio‐assessment is not included in the Standard Method as it is still
being developed (CCME, 2008).
3.1 Water Uses
EQOs are numerical values and narrative statements established to protect the receiving water – in this
case the Atlantic Ocean near the breakwater in Glace Bay Harbour. The first step in determining EQOs is
to define the potential beneficial uses of the receiving water.
The following beneficial water uses have been identified for the Atlantic Ocean in the vicinity of Glace
Bay:
Direct contact recreational activities like swimming and wading at Table Head Beach to the
north and Big Glace Bay Beach to the south (shown on Figure 3.1, below);
Secondary contact recreational activities like boating and fishing; and
Ecosystem health for marine aquatic life.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 13
There is no molluscan shellfish harvesting zone in the vicinity of the outfall. The outfall is situated in a
closure zone boundary extending from Point Aconi to Schooner Pond, situated 2500 m offshore in the
vicinity of the outfall (shown on Figure 3.1).
Figure 3.1 Location of Existing Outfalls
3.2 Ambient Water Quality
Generic EQOs are first developed based on existing guidelines and then adjusted based on site‐
specific factors, particularly background water quality. Water quality data was obtained for two
locations in the Atlantic Ocean along the coast of Cape Breton. The locations were chosen in an
attempt to be representative of ambient water quality outside the influence of the existing
untreated wastewater discharges in CBRM. Samples were collected by HE on May 11, 2018, and the
sample locations are summarized as follows and presented in Figure 3.2. A second set of samples
was collected by HE on November 18, 2018 and analyzed for metals using a different laboratory
method due to elevated detection limits in the first set of samples.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 14
BG‐1: Near Mira Gut Beach
BG‐2: Wadden’s Cove
Figure 3.2 Ambient Water Quality Sample Locations
A third sample was collected north of Port Morien but the results were not considered
representative of background conditions as sample results indicated that the sample was impacted
by wastewater. A summary of the ambient water quality data is shown in Tables 3.1 through 3.5.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 15
Table 3.1 – Ambient Water Quality Data – General Chemistry
Parameter Units BG1 BG2 AVG
Carbonaceous BOD (CBOD) mg/L <5.0 <5.0 <5.0
COD mg/L 1100 1000 1050
Hardness mg/L 4900 5200 5050
Nitrogen (Ammonia Nitrogen) mg/L <0.050 <0.050 <0.05
TSS mg/L 58 5.0 32
Total Phosphorus (TP) mg/L 0.037 0.032 0.035
Total Kjeldahl Nitrogen (TKN) mg/L 0.19 0.20 0.20
pH pH 7.73 7.68 7.71
unionized ammonia mg/L <0.0007 <0.0007 <0.0007
E. coli MPN/100mL 52 86 69
TRC mg/L NM NM NM
Fluoride mg/L 0.67 0.67 0.67
Nitrate (N) mg/L 0.051 <0.050 0.038
Nitrite (N) mg/L <0.010 <0.010 <0.010
Nitrate + Nitrite mg/L 0.051 <0.050 0.038
Total Nitrogen (TN) mg/L 0.241 0.225 0.233
Total Cyanide mg/L <0.0010 <0.0010 <0.0010
Note:
NM = Parameter not measured.
Parameters reported as < detection limit have been included in average calculation as half the
detection limit.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 16
Table 3.2 – Ambient Water Quality Data – Metals
Parameter Units BG1 BG2 AVG
May‐11 Nov‐18 May‐11 Nov‐18
Aluminum mg/L 0.17 0.089 0.083 0.754 0.274
Antimony mg/L <0.010(2) <0.0005 <0.010(2) <0.0005 <0.0005
Arsenic mg/L <0.010 0.00163 <0.010 0.00177 0.0017
Barium mg/L <0.010 0.0074 <0.010 0.0083 0.00785
Beryllium mg/L <0.010(2) <0.001 <0.010(2) <0.001 <0.001
Boron mg/L 3.5 3.42 3.7 3.43 3.51
Cadmium mg/L <0.00010(2) <0.00005 <0.00010(2) <0.00005 <0.00005
Chromium mg/L <0.010(2) <0.0005(1) <0.010(2) 0.00056 0.00041
Cobalt mg/L <0.0040(2) <0.0001(1) <0.0040(2) 0.00031 0.00018
Copper mg/L <0.020(2) <0.0005(1) <0.020(2) 0.00068 0.00047
Iron mg/L <0.50(2) 0.159 <0.50(2) 0.626 0.393
Lead mg/L <0.0050(2) 0.00015 <0.0050(2) 0.0003 0.000225
Manganese mg/L 0.021 0.00747 <0.020(2) 0.0165 0.01499
Molybdenum mg/L <0.020(2) 0.0095 <0.020(2) 0.0086 0.0091
Nickel mg/L <0.020(2) <0.00020 <0.020(2) <0.00020 <0.00020
Selenium mg/L <0.010(2) <0.0005 <0.010(2) <0.0005 <0.0005
Silver mg/L <0.0010(2) <0.00005 <0.0010(2) <0.00005 <0.00005
Strontium mg/L 5.9 7.27 6.3 7.32 6.70
Thallium mg/L <0.0010(2) <0.00010 <0.0010(2) <0.00010 <0.00010
Tin mg/L <0.020(2) <0.001 <0.020(2) <0.001 <0.001
Titanium mg/L <0.020(2) <0.010 <0.020(2) 0.046 0.026
Uranium mg/L 0.0026 0.00248 0.0026 0.00242 0.00253
Vanadium mg/L <0.020(2) <0.01 <0.020(2) <0.01 <0.01
Zinc mg/L <0.050(2) <0.001 <0.050(2) 0.0014 0.00095
Mercury mg/L 0.000013 ‐ 0.000013 ‐ 0.000013
Note:
(1) Value included in average calculation as half the detection limit.
(2) Value omitted from average calculation due to elevated detection limit.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 17
Table 3.3 – Ambient Water Quality Data – VOCs
Parameter Units BG1 BG2 AVG
1,2‐dichlorobenzene µg/L <0.50 <0.50 <0.50
1,4‐dichlorobenzene µg/L <1.0 <1.0 <1.0
Chlorobenzene µg/L <1.0 <1.0 <1.0
1,1,2,2‐tetrachloroethane µg/L <0.50 <0.50 <0.50
1,1‐Dichloroethylene µg/L <0.50 <0.50 <0.50
1,2‐dichloroethane µg/L <1.0 <1.0 <1.0
Benzene µg/L <1.0 <1.0 <1.0
Bromodichloromethane µg/L <1.0 <1.0 <1.0
Bromoform µg/L <1.0 <1.0 <1.0
Carbon Tetrachloride µg/L <0.50 <0.50 <0.50
Chloroform µg/L <1.0 <1.0 <1.0
Dibromochloromethane µg/L <1.0 <1.0 <1.0
Ethylbenzene µg/L <1.0 <1.0 <1.0
Methylene Chloride
(Dichloromethane) µg/L <3.0 <3.0 <3.0
o‐xylene µg/L <1.0 <1.0 <1.0
m/p‐xylene µg/L <2.0 <2.0 <2.0
Tetrachloroethene
(Tetrachloroethylene) µg/L <1.0 <1.0 <1.0
Toluene µg/L <1.0 <1.0 <1.0
Trichloroethene (Trichloroethylene) µg/L <1.0 <1.0 <1.0
Vinyl Chloride µg/L <0.50 <0.50 <0.50
Harbour Engineering Joint Venture Glace Bay WWTP ERA 18
Table 3.4 – Ambient Water Quality Data – PCBs, Phenols, PAHs
Parameter Units BG1 BG2 AVG
Total PCBs µg/L <0.05 <0.05 <0.05
Phenols mg/L 0.011 <0.010 0.0305
1‐Methylnaphthalene µg/L <0.050 <0.050 <0.050
2‐Methylnaphthalene µg/L <0.050 <0.050 <0.050
Acenaphthene µg/L <0.010 <0.010 <0.010
Acenaphthylene µg/L <0.010 <0.010 <0.010
Anthracene µg/L <0.010 <0.010 <0.010
Benzo(a)anthracene µg/L <0.010 <0.010 <0.010
Benzo(a)pyrene µg/L <0.010 <0.010 <0.010
Benzo(b)fluoranthene µg/L <0.010 <0.010 <0.010
Benzo(g,h,i)perylene µg/L <0.010 <0.010 <0.010
Benzo(k)fluoranthene µg/L <0.010 <0.010 <0.010
Chrysene µg/L <0.010 <0.010 <0.010
Dibenz(a,h)anthracene µg/L <0.010 <0.010 <0.010
Fluoranthene µg/L <0.010 <0.010 <0.010
Fluorene µg/L <0.010 <0.010 <0.010
Indeno(1,2,3‐cd)pyrene µg/L <0.010 <0.010 <0.010
Naphthalene µg/L <0.20 <0.20 <0.20
Phenanthrene µg/L <0.010 <0.010 <0.010
Pyrene µg/L <0.010 <0.010 <0.010
Table 3.5 – Ambient Water Quality Data – Organochlorine Pesticides
Parameter Units BG1 BG2 AVG
Aldrin µg/L <0.005 <0.005 <0.005
Dieldrin µg/L <0.005 <0.005 <0.005
a‐Chlordane µg/L <0.005 <0.005 <0.005
g‐Chlordane µg/L <0.005 <0.005 <0.005
o,p‐DDT µg/L <0.005 <0.005 <0.005
p,p‐DDT µg/L <0.005 <0.005 <0.005
Lindane µg/L <0.003 <0.003 <0.003
Endosulfan I (alpha) µg/L <0.005 <0.005 <0.005
Endosulfan II (beta) µg/L <0.005 <0.005 <0.005
Endrin µg/L <0.005 <0.005 <0.005
Heptachlor µg/L <0.005 <0.005 <0.005
Heptachlor epoxide µg/L <0.005 <0.005 <0.005
Methoxychlor µg/L <0.01 <0.01 <0.01
alpha‐BHC µg/L <0.005 <0.005 <0.005
Mirex µg/L <0.005 <0.005 <0.005
Toxaphene µg/L <0.2 <0.2 <0.2
DDT+ Metabolites µg/L <0.005 <0.005 <0.005
Harbour Engineering Joint Venture Glace Bay WWTP ERA 19
3.3 Physical/ Chemical/ Pathogenic Approach
The physical/ chemical/ pathogenic approach is intended to protect the receiving water by ensuring that
water quality guidelines for particular substances are being met. EQOs are established by specifying the
level of a particular substance that will protect water quality. Substance levels that will protect water
quality are taken from the CEQGs associated with the identified beneficial water uses. If more than one
guideline applies, the most stringent is used. Typically, the Canadian Water Quality Guidelines (CWQGs)
for the Protection of Aquatic Life are the most stringent and have been used for this assessment. The
Health Canada Guidelines for Canadian Recreational Water have also been used to provide limits for
pathogens (E. coli).
The guidelines for the Protection of Aquatic Life provide recommendations for both freshwater and
marine (including estuarine) environments. Since the receiving water for the proposed Glace Bay
WWTP is a marine environment, the marine guidelines were used where available. The US EPA
National Recommended Water Quality Criteria (saltwater) were used when there were no CCME
marine criteria provided. For substances where a marine criterion was not specified by either CCME
or US EPA, the CCME freshwater guidelines were used. However, in marine environments, utilizing
freshwater water quality objectives may result in EQOs and EDOs that are overly conservative. There
were some parameters that were detected in the wastewater but for which a criterion did not exist
from either CCME or the US EPA. In those instances, an effort was made to identify an applicable
criterion from another jurisdiction, such as British Columbia Ministry of Environment (BCMOE).
Technical Supplement 3 of the Canada‐wide Strategy for the Management of Municipal Wastewater
Effluent indicates that for any one substance, if the natural concentration in the upstream location is
higher than the generic EQO equivalent, that concentration will apply as a site‐specific EQO, and the
generic EQO must be set aside. Otherwise, site‐specific EQOs are not needed. Background water
quality samples were collected from the Atlantic Ocean by HE on May 11, 2018 and the results were
previously summarized in Section 3.2.
Site‐specific EQOs were developed for each substance that was detected in the wastewater, for
which there was a generic EQO, and for which the background concentration exceeded the generic
EQO. Site‐specific EQOs are discussed in the following sections and included in Table 3.8. EQOs are
derived in the following sections for each substance of potential concern for a medium facility that
was detected in the wastewater.
3.3.1 General Chemistry/ Nutrients
The following general chemistry and nutrients parameters were identified as substances of potential
concern for a medium facility: CBOD, chemical oxygen demand (COD), un‐ionized ammonia, total
ammonia, total kjeldahl nitrogen (TKN), total suspended solids (TSS), total phosphorus, pH, total
residual chlorine (TRC), fluoride, nitrate, nitrite and total cyanide. EQOs for these substances are
established in the following sections.
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Oxygen Demand
Biochemical Oxygen Demand (BOD5) is a measure of the oxygen required to oxidize organic material
and certain inorganic materials over a given period of time (five days). It has two components:
carbonaceous oxygen demand and nitrogenous oxygen demand.
Chemical Oxygen Demand (COD) is another measure of oxygen depleting substances present in the
effluent. It is a measure of the oxygen required to chemically oxidize reduced minerals and organic
matter.
Carbonaceous Biochemical Oxygen Demand (CBOD5) measures the amount of biodegradable
carbonaceous material in the effluent that will require oxygen to break down over a given period of
time (five days). The CBOD5 discharged in wastewater effluent reduces the amount of dissolved
oxygen in the receiving water. Dissolved oxygen is an essential parameter for the protection of
aquatic life; and the higher the CBOD5 concentration, the less oxygen that is available for aquatic
life.
Traditionally performance standards have been set for BOD5; however, the WSER dictate a limit for
CBOD5. This is due to the variable effects of nitrogenous oxygen demand on the BOD5 test.
There are no CWQGs for the protection of aquatic life for CBOD5 in freshwater or in marine waters.
However, because CBOD5 affects the concentration of dissolved oxygen, the CWQG for dissolved
oxygen should be considered. The CWQG for freshwater aquatic life dictates that the dissolved
oxygen concentrations be greater than 9.5 mg/L for early life stages in cold water ecosystems. The
CWQG for marine aquatic life is a minimum of 8 mg/L.
The background dissolved oxygen concentrations were not measured in the receiving water.
However, the concentration of CBOD5 discharged in accordance with the WSER criteria should not
cause the dissolved oxygen (DO) concentration to vary outside of the normal range. Based on an
average annual temperature of 6.9 °C (from Bedford Institute of Oceanography Area 4VN), the
solubility of oxygen in seawater is approximately 9.5 mg/L. Assuming the background concentration
of DO is saturated, there can be a drop of 1.5 mg/L for the DO to be a minimum concentration of 8
mg/L. The average annual temperature was used in this calculation as if the maximum annual
temperature was used, this results in the solubility of oxygen being less than the CWQG for marine
aquatic life. For an ocean discharge, the maximum DO deficit should occur at the point source.
Assuming a deoxygenation rate of 0.23/day based on a depth of approximately 4.3 m at the
proposed discharge location (with a 100 m outfall extension), and assuming a reaeration coefficient
of 0.21/day based on a depth of approximately 4.3 m and an average tidal velocity of 0.062 m/s, the
maximum concentration of CBOD that would result in a drop in DO of 1.5 mg/L can be calculated.
The tidal dispersion coefficient has been assumed to be 150 m2/s. The concentration of CBOD
potentially affecting DO was calculated to be 11.75 mg/L. Therefore, the WSER criteria of 25 mg/L
CBOD at discharge should not cause the dissolved oxygen (DO) concentration to vary outside of the
normal range provided initial dilution is at least 2.2:1. The background level of CBOD was less than
the detection limit of 5 mg/L.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 21
Total Ammonia and Un‐ionized Ammonia
The CWQG for the protection of aquatic life for total ammonia in freshwater is presented as a table
based on pH and temperature. There is no CWQG for ammonia in marine water. Total ammonia is
comprised of un‐ionized ammonia (NH3) and ionized ammonia (NH4+, ammonium). Un‐ionized
ammonia is more toxic than ionized ammonia and the toxicity of total ammonia is related to the
concentration of un‐ionized ammonia present. The amount of un‐ionized ammonia is variable
depending on pH and temperature. The US EPA saltwater guideline for total ammonia is 2.7 mg/L
based on a temperature of 17.7 °C, a pH of 7.7 and a salinity of 30 g/kg. The US EPA guideline of 2.7
mg/L will be used as the EQO for total ammonia. As ammonia is a component of total nitrogen (TN),
the actual effluent concentration may be limited by the TN EDO rather than the total ammonia EDO.
However, as the TN EQO is based on concern of eutrophication and not a continuous acceptable
concentration for the protection of aquatic life, both EDOs will be presented separately in the ERA.
The WSER requires that un‐ionized ammonia concentrations be less than 1.25 mg/L at the discharge
point. For the purposes of this study, the EQO for un‐ionized ammonia was chosen based on the
WSER (1.25 mg/L at discharge).
Total Suspended Solids (TSS)
The WSER specifies a limit of 25 mg/L for TSS at the end of the pipe. The CWQG for the protection of
aquatic life in marine water for total suspended solids (TSS) is as follows:
During periods of clear flow, a maximum increase of 25 mg/L from background levels for any
short‐term exposure (e.g., 24‐h period). Maximum average increase of 5 mg/L from
background levels for longer term exposures (e.g., inputs lasting between 24 h and 30 d);
and
During periods of high flow, a maximum increase of 25 mg/L from background levels at any
time when background levels are between 25 and 250 mg/L. Should not increase more than
10% of background levels when background is ≥ 250 mg/L.
The background concentration of TSS was an average of 32 mg/L. A maximum average increase of 5
mg/L from background levels would result in an EQO of 37 mg/L. As this is greater than the WSER
criteria, the WSER criteria of 25 mg/L at discharge will apply as the EDO. The background TSS
measurement is higher than would typically be expected in a marine environment, which may be
due to the near shore location of the samples. However, in a worst‐case scenario where the
background TSS concentration was 0 mg/L, application of the WSER criteria at the end of pipe would
always be the more stringent criteria provided there is greater than five times dilution.
Total Phosphorus and TKN/TN
There are no CWQGs for the protection of aquatic life for phosphorus, Total Kjeldahl Nitrogen (TKN)
or total nitrogen (TN). However, in both freshwater and marine environments, adverse secondary
effects like eutrophication and oxygen depletion can occur. Guidance frameworks have been
established for freshwater systems and for marine systems to provide an approach for developing
site‐specific water quality guidelines. These approaches are based on determining a baseline
condition and evaluating various effects according to indicator variables. The approach is generally
Harbour Engineering Joint Venture Glace Bay WWTP ERA 22
very time and resource intensive, but can be completed on a more limited scale to establish interim
guidelines.
The Canadian Guidance Framework for the Management of Nutrients in Nearshore Marine Systems
Scientific Supporting Document (CCME, 2007) provides a framework as well as case studies for
establishing nutrient criteria for nearshore marine systems. This document provides a Trophic Index
for Marine Systems (TRIX), below in Table 3.6.
Table 3.6 ‐ Criteria for evaluating trophic status of marine systems (CCME, 2007)
Trophic Status TN
(mg/m3)
TP
(mg/m3) Chlorophyll a (μg/L) Secchi Depth
(m)
Oligotrophic <260 <10 <1 >6
Mesotrophic ≥260‐350 ≥10‐30 ≥1‐3 3‐≤6
Eutrophic ≥350‐400 ≥30‐40 ≥3‐5 1.5‐≤3
Hypereutrophic >400 >40 >5 <1.5
The background concentrations of total nitrogen (TN) and total phosphorus (TP) were measured as
0.233 mg/L and 0.035 mg/L, respectively, which corresponds to a eutrophic status based on the
phosphorus concentration. The uppermost limit for this trophic status is a TN concentration of 0.4
mg/L and a TP concentration of 0.04 mg/L.
This document provides another index (NOAA) to determine the degree of eutrophication of the
marine system, below in Table 3.7.
Table 3.7 ‐ Trophic status classification based on nutrient and chlorophyll (CCME, 2007)
Degree of
Eutrophication
Total Dissolved N
(mg/L)
Total Dissolved P
(mg/L)
Chl a
(μg/L)
Low 0 ‐ ≤0.1 0 ‐ ≤0.01 0 ‐ ≤5
Medium >0.1 ‐ ≤1 >0.01 ‐ ≤0.1 >5 ‐ ≤20
High >1 >0.1 >20 ‐ ≤60
Hypereutrophic ‐ ‐ >60
However, the concentrations in Table 3.7 are based on dissolved nitrogen and phosphorus and the
background concentrations are for total nitrogen and total phosphorus (0.233 mg/L and 0.035 mg/L,
respectively). For nitrogen, with a background concentration of 0.233 mg/L for TN, an assumption
that the dissolved nitrogen background concentration is anywhere between 43 and 100% of the TN
background concentration would result in classification as “medium” based on Table 3.7. For
phosphorus, with a background concentration of 0.035 mg/L, an assumption that the dissolved
background concentration is anywhere between 29 and 100% of the total background concentration
would result in classification as “medium” based on Table 3.7.
To maintain the same degree of eutrophication, the total dissolved nitrogen and total dissolved
phosphorus in the receiving water should not exceed the upper limit of the “medium” classification
which is 1 mg/L for Total Dissolved Nitrogen and 0.1 mg/L for Total Dissolved Phosphorus. In order
to determine the upper limit of the “medium” eutrophication range based on total phosphorus and
Harbour Engineering Joint Venture Glace Bay WWTP ERA 23
TN concentrations, an assumption must be made as to the percentage of the nitrogen and
phosphorus that exists in the dissolved phase, both in the receiving water and in the effluent. As a
measure of conservatism, an assumption was made that 100% of the total nitrogen and phosphorus
exist in a dissolved phase. This allows for the upper limits of the “medium” classification to be used
directly as the EQO which results in an EQO of 1 mg/L for TN and 0.1 mg/L for total phosphorus.
The Canadian Guidance Framework for the Management of Nutrients in Nearshore Marine Systems
Scientific Supporting Document (CCME, 2007) presents both of the above criteria for assessing
trophic status and does not provide a recommendation for use of one rather than the other.
However, the framework presents a case study to establish nutrient criteria for the Atlantic
Shoreline of Nova Scotia, and the NOAA index is used. Therefore, that index will be used for the
purpose of this study.
pH
The CWQG for the protection for aquatic life for marine waters is 7.0 to 8.7. This pH range will be
applied as the EQO.
Fluoride
The CCME CWQG for the protection of aquatic life for fluoride is 0.12 mg/L for freshwater. There is
no recommended marine guideline from either CCME or US EPA. The background concentration for
fluoride is 0.67 mg/L. There is a maximum acceptable concentration of 1.5 mg/L specified by the
British Columbia Ministry of Environment (BCMOE). However, as this is a maximum acceptable
concentration and not a long term or continuous concentration, it will not be used. Therefore, the
background concentration of 0.67 mg/L will be applied as the site‐specific EQO.
Nitrate
The CCME CWQG for the protection of aquatic life for nitrate is 200 mg/L for marine waters, 45
mg/L as N. Nitrate is substantially less toxic than nitrite and ammonia, but can still yield toxic effects.
Background pH and temperature can influence the conversion of nitrate to nitrite and other forms
of nitrogen. Typically, the CCME marine water quality guideline of 45 mg/L would be used as the
EQO, however, the total nitrogen EQO determined to limit eutrophication will govern (at 1.0 mg/L).
As the TN EQO is based on a concern of eutrophication, both limits will be presented separately in
the ERA.
Nitrite
The CCME CWQG for the protection of aquatic life for nitrite is 0.06 mg/L as nitrogen for freshwater,
and there is no recommended marine guideline. Nitrite has been found to be more toxic to some
groups of fish, particularly salmonids. The freshwater guideline of 0.06 mg/L will be applied as the
EQO for this assessment. However, this generic objective may be overly conservative when applied
to the marine receiving environment.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 24
Cyanide
The CCME CWQG for the protection of aquatic life for cyanide is 0.005 mg/L (free CN) for
freshwater. There is no CWQG for marine waters. The US EPA water quality criterion for saltwater is
0.001 mg/L (free CN). Both the CCME and US EPA criteria are for free cyanide, whereas the Standard
Method specifies to sample for total cyanide. Cyanide was not detected in the background samples.
The US EPA criteria of 0.001 mg/L will be applied as the EQO for cyanide. However, comparing
sample results from the wastewater characterization samples to this value will be overly
conservative as the analytical results are for total cyanide rather than free cyanide.
Total Residual Chlorine
The WSER requires that TRC concentrations be less than 0.02 mg/L. For the purposes of this study,
an EQO/EDO of 0.02 mg/L for TRC was chosen based on this regulation.
3.3.2 Metals
Of the 25 metals measured during the wastewater characterization study, 15 were detected in the
wastewater of at least one sample. The EQOs for the detected metals are described below.
Aluminum
The CCME CWQG for the protection of aquatic life for aluminum in freshwater is dependent on pH;
the guideline is 5 µg/L if the pH is less than 6.5 and 100 µg/L if the pH is 6.5 or greater. There are no
CWQG or USEPA guidelines for marine waters. The average background concentration of aluminum
was 274 µg/L. The background concentration of 274 µg/L will be used as the site‐specific EQO.
Barium
There are no CCME CWQGs for the protection of aquatic life for barium in freshwater or marine
waters. There is also no water quality guideline from the US EPA or British Columbia Ministry of
Environment (BCMOE) for salt water. As no relevant published water quality guidelines were found
for barium, an EQO will not be developed.
Cadmium
The CCME CWQG for the protection of aquatic life for cadmium in marine waters is 0.12 µg/L.
Cadmium was not detected in the background sample (at a detection limit of 0.05 µg/L). Therefore
the EQO will remain the same as the CCME marine CWQG of 0.12 µg/L.
Cobalt
There are no CCME CWQGs for the protection of aquatic life for cobalt in freshwater or marine
waters. There is also no US EPA water quality guideline. There are no water quality guidelines from
the BCMOE for marine waters. As no relevant published water quality guidelines were found for
cobalt, an EQO will not be developed.
Copper
The CCME CWQG for the protection of aquatic life for copper in freshwater is given as an equation
based on water hardness and there is no guideline specified for marine waters. The freshwater
guideline was calculated to be 4 µg/L based on the average background water hardness of 5050
Harbour Engineering Joint Venture Glace Bay WWTP ERA 25
mg/L. The US EPA salt water quality criterion is 3.7 µg/L. The average background concentration of
copper was 0.47 µg/L. Therefore the USEPA salt water quality criterion of 3.7 µg/L will be used as
the EQO.
Iron
The CCME CWQG for the protection of aquatic life for iron in freshwater is 300 µg/L. There is no
guideline specified for marine waters. There is no US EPA or BC MOE salt water quality criterion for
iron. The average background concentration for iron was 393 µg/L. The EQO will be based on the
background concentration of 393 µg/L. However, this may be overly conservative for a marine
environment as the generic EQO is based on a freshwater guideline.
Lead
The CCME CWQG for the protection of aquatic life for lead in freshwater is given as an equation
based on water hardness and there is no guideline specified for marine waters. The freshwater
guideline was calculated to be 6 µg/L based on the average background water hardness of 5050
mg/L. The US EPA salt water quality criterion is 8.5 µg/L. The average background concentration of
lead was 0.225 µg/L. Therefore the USEPA salt water quality criterion of 8.5 µg/L will be used as the
EQO.
Manganese
There are no CCME CWQGs for the protection of aquatic life for manganese in freshwater or marine
waters. There is also no criterion provided by US EPA. However, there is a working water quality
guideline for marine aquatic life for manganese provided by the BCMOE of 100 µg/L. The
background concentration of manganese was 15 µg/L. The guideline of 100 µg/L will be used as the
EQO for manganese.
Molybdenum
The CCME CWQG for the protection of aquatic life for molybdenum is 73 µg/L for freshwater and
there is no guideline for marine waters. There is no US EPA water quality guideline for salt water.
There is no BCMOE criteria for marine water. The average concentration of molybdenum in the
background samples was 9.1 µg/L. The CCME CWQG for freshwater of 73 µg/L will be applied as the
EQO. However, this may be overly conservative for a marine environment as the generic EQO is
based on a freshwater guideline.
Nickel
The CCME CWQG for the protection of aquatic life for nickel is 150 µg/L for freshwater based on an
average background hardness of 5050 mg/L. There is no CWQG for marine waters. The US EPA salt
water quality criterion is 8.3 µg/L. Nickel was not detected in the background samples (at a
detection limit of 0.2 µg/L). Therefore the US EPA salt water quality criterion of 8.3 µg/L will be used
as the EQO.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 26
Strontium
There is no CCME CWQG for strontium for the protection of aquatic life. There is no water quality
guideline provided by US EPA or BCMOE. As no relevant published water quality guidelines were
found for strontium, an EQO will not be developed.
Titanium
There is no CCME CWQG for titanium for the protection of aquatic life. There is no water quality
guideline provided by US EPA or BCMOE. As no relevant published water quality guidelines were
found for titanium, an EQO will not be developed.
Uranium
The CCME CWQG for the protection of aquatic life for uranium is 15 µg/L for freshwater and there is
no guideline for marine waters. There is no US EPA water quality guideline for salt water. There is no
BCMOE criteria for marine water. The background concentration for uranium was 2.53 µg/L. The
CCME WQG for freshwater of 15 µg/L will be applied as the EQO. However, this may be overly
conservative for a marine environment as the generic EQO is based on a freshwater guideline.
Zinc
The CCME CWQG for the protection of aquatic life for zinc is 30 µg/L for freshwater and there is no
guideline for marine waters. The US EPA water quality guideline for salt water is 86 µg/L. The
average background concentration of zinc was 0.95 µg/L. The US EPA criterion of 86 µg/L will be
applied as the EQO for zinc.
Mercury
The CCME WQG for the protection of aquatic life for mercury is 0.026 µg/L for freshwater and 0.016
µg/L for marine waters. The US EPA water quality guideline for salt water is 1.1 µg/L. The EQO will
be the CCME marine guideline of 0.016 µg/L.
3.3.3 E. coli
Pathogens are not included in the CCME CWQGs for the protection of aquatic life. The Health
Canada Guidelines for Canadian Recreational Water Quality specify a maximum E. coli concentration
of 200 E. coli/100 mL for freshwater for primary contact recreation and 1000 E. coli/100 mL for
secondary contact recreation. The Health Canada guideline for Canadian Recreational Water Quality
for primary and secondary contact recreation in marine water is based on enterococci rather than E.
coli. However, historically Nova Scotia Environment has set discharge limits for E. coli rather than
enterococci for marine discharges. The background concentration of E. coli was 69 E. coli/100 mL.
An EQO of 200 E. coli/ 100 mL will apply for primary contact recreation at Table Head and Big Glace
Bay beaches. An EQO of 1000 E. coli/ 100mL based on the Canadian Recreational Water Quality
guideline for secondary contact for freshwater will apply elsewhere in the receiving water.
There is currently a molluscan shellfish closure zone in the immediate vicinity of the outfall (SSN‐
2006‐007 on Figure 3.1). However, consideration will have to be given to E. coli concentrations
outside of the closure zone. It is also possible that the closure zone will be changed once the
proposed WWTPs in CBRM are operational. The Canadian Shellfish Sanitation Program (CSSP)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 27
requires that the median of the samples collected in an area in one survey not exceed 14 E. coli/100
mL, and no more than 10% of the samples can exceed 43 E. coli/100 mL. However, the average
measured background concentration for E. coli was 69 E. coli/100 mL. These background samples
were collected from shore and may not be representative of the actual ambient concentration of E.
coli in the area.
3.3.3.1 ORGANOCHLORINE PESTICIDES
Of the list of organochlorine pesticides included in the Standard Method for substances of potential
concern for a medium facility, there were no detections. There were detections for one
organochlorine pesticide (endrin aldehyde). As this parameter is not included in the standard
method, an EDO was not developed. This parameter could be considered in the future development
of the compliance monitoring program.
3.3.3.2 POLYCHLORINATED BIPHENYLS (PCBS)
Total polychlorinated biphenyls (PCBs) were not detected in the wastewater and therefore an EQO
was not established.
3.3.3.3 POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)
Polycyclic aromatic hydrocarbons (PAHs) were measured as part of initial wastewater
characterization. Of the list of PAHs included in the Standard Method for substances of potential
concern for a medium facility, 14 substances were detected during the initial wastewater
characterization study: acenaphthene, anthracene, benzo(a)anthracene, benzo(a)pyrene,
Benzo(b)fluoranthene, benzo(g,h,i)perylene, benzo(k)fluoranthene, chrysene,
dibenz(a,h)anthracene, fluoranthene, fluorene, indeno(1,2,3‐cd)pyrene, pyrene, and phenanthrene.
There are CCME CWQGs for the protection of aquatic life for freshwater for 8 of the 14 substances
that were detected. There were no CCME marine water quality guidelines. There are BC MOE
approved marine water quality guidelines for 3 of the 14 substances. The guidelines are as follows:
Acenaphthene – 5.8 µg/L (freshwater), 6 µg/L (BCMOE marine);
Anthracene – 0.012 µg/L (freshwater);
Benzo(a)anthracene – 0.018 µg/L (freshwater);
Benzo(a)pyrene – 0.015 µg/L (freshwater);
Chrysene – 0.1 µg/L (BCMOE marine);
Fluoranthene – 0.04 µg/L (freshwater);
Fluorene – 3 µg/L (freshwater), 12 µg/L (BCMOE marine);
Phenanthrene – 0.4 µg/L (freshwater); and
Pyrene – 0.025 µg/L (freshwater).
None of the nine (9) substances listed above were detected in the background sample. Therefore,
the above guidelines will be applied as the EQOs. However, the freshwater generic objectives may
be overly conservative when applied to the marine receiving environment.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 28
3.3.3.4 VOLATILE ORGANIC COMPOUNDS (VOCS)
Of the list of Volatile organic compounds (VOCs) included in the Standard Method for substances of
potential concern for a medium facility, 3 were detected in the wastewater. There are CCME CWQGs
for the protection of aquatic life for freshwater for 2 of the 3 substances that were detected. There
is a marine guideline for one of the substances that was detected. There are no applicable guidelines
for bromodichloromethane. The guidelines are as follows:
Chloroform – 1.8 µg/L (freshwater); and
Toluene – 2 µg/L (freshwater), 215 µg/L (marine).
The above bolded guidelines will be applied as the EQOs. However, the freshwater generic
objectives may be overly conservative when applied to the marine receiving environment.
3.3.3.5 PHENOLIC COMPOUNDS
The CCME CWQG for the protection of aquatic life for phenols in freshwater is 4 µg/L. There is no
guideline specified for marine waters. There is no US EPA or BCMOE salt water quality criterion for
phenols. The background concentration was 0.0305 mg/L. The EQO will be based on the background
concentration of 0.0305 mg/L.
3.3.3.6 SURFACTANTS
Surfactants were not analyzed in the wastewater samples. This analysis was not available locally,
and there are no CWQG available from either CCME or US EPA for non‐ionic or anionic surfactants to
compare the results to if the analysis was completed.
3.3.4 Summary
Table 3.8 below gives a summary of the generic and site‐specific EQOs determined for parameters of
concern. The source of the EQO has been included in the table as follows:
WSER – wastewater systems effluent regulations
Background – Site‐specific EQO based on background concentration in receiving water
CWQG Marine – CCME Canadian Water Quality Guidelines for the Protection of Aquatic Life
Marine
USEPA Saltwater – United States Environmental Protection Agency National Recommended
Water Quality Criteria – Aquatic Life Criteria – Saltwater Criterion Continuous Concentration
CGF, Marine – Canadian Guidance Framework for the Management of Nutrients in Nearshore
Marine Systems Scientific Supporting Document
BCMOE AWQG – BCMOE Approved Water Quality Guideline
BCMOE WWQG – BCMOE Working Water Quality Guideline
CWQG Freshwater – CCME Canadian Water Quality Guidelines for the Protection of Aquatic Life
Freshwater
HC Primary Contact – Health Canada Guidelines for Canadian Recreational Water Quality –
Primary Contact Recreation
HC Secondary Contact – Health Canada Guidelines for Canadian Recreational Water Quality –
Secondary Contact Recreation
CSSP – Canadian Shellfish Sanitation Program
Harbour Engineering Joint Venture Glace Bay WWTP ERA 29
Table 3.8 – EQO Summary
Parameter Generic EQO Background Selected
EQO Source
CBOD5 (mg/L) 25 <5.0 25 WSER
Total NH3‐N (mg/L)(1) 2.7 <0.05 2.7 USEPA Saltwater
TSS (mg/L) 25 32 25 WSER
TP (mg/L) 0.1 0.035 0.1 CGF, Marine
TN (mg/L)(1) 1 0.233 1 CGF, Marine
pH 7 ‐ 8.7 7.71 7 ‐ 8.7 CWQG Marine
Un‐ionized NH3 (mg/L) 1.25 <0.0007 1.25 WSER
E. coli ‐ Primary Contact
(MPN/100mL) 200 69 200 HC Primary Contact
E. coli ‐ Secondary Contact
(MPN/100mL) 1000 69 1000 HC Secondary
Contact
E. coli ‐ Molluscan Shellfish
(MPN/100mL) 14 69 14 CSSP
Fluoride (mg/L) 0.67 0.67 0.67 Background
Nitrate (mg/L)(1) 45 0.038 45 CWQG Marine
Nitrite (mg/L) 0.06 <0.001 0.06 CWQG Freshwater
Free Cyanide (mg/L) 0.001 <0.0010 0.001 USEPA Saltwater
Aluminum (mg/L) 0.1 0.274 0.274 Background
Cadmium (mg/L) 0.00012 <0.00005 0.00012 CWQG Marine
Copper (mg/L) 0.0037 0.00047 0.0037 USEPA Saltwater
Iron (mg/L) 0.3 0.393 0.393 Background
Lead (mg/L) 0.0085 0.000225 0.0085 USEPA Saltwater
Manganese (mg/L) 0.1 0.015 0.1 BCMOE WWQG
Molybdenum (mg/L) 0.073 0.0091 0.073 CWQG Freshwater
Nickel (mg/L) 0.0083 <0.0002 0.0083 USEPA Saltwater
Uranium (mg/L) 0.015 0.00253 0.015 CWQG Freshwater
Zinc (mg/L) 0.086 0.00095 0.086 USEPA Saltwater
Mercury (mg/L) 0.000016 0.000013 0.000016 CWQG Marine
Acenaphthene (µg/L) 6 <0.010 6 BCMOE AWQG
Anthracene (µg/L) 0.012 <0.010 0.012 CWQG Freshwater
Benzo(a)anthracene (µg/L) 0.018 <0.010 0.018 CWQG Freshwater
Benzo(a)pyrene (µg/L) 0.015 <0.010 0.015 CWQG Freshwater
Chrysene (µg/L) 0.1 <0.010 0.1 BCMOE AWQG
Fluoranthene (µg/L) 0.04 <0.010 0.04 CWQG Freshwater
Fluorene (µg/L) 12 <0.010 12 BCMOE AWQG
Phenanthrene (µg/L) 0.4 <0.010 0.4 CWQG Freshwater
Pyrene (µg/L) 0.025 <0.010 0.025 CWQG Freshwater
Chloroform (µg/L) 1.8 <1.0 1.8 CWQG Freshwater
Toluene (µg/L) 215 <1.0 215 CWQG Marine
Phenols (mg/L) 0.004 0.0305 0.0305 Background
Notes: Bold indicates EQO is a WSER requirement.
(1) Although the EQOs for ammonia and nitrate have been calculated to be 2.7 mg/L and 45 mg/L, respectively, the EQO of 1 mg/L for total nitrogen
would govern. However, as the EQO for TN is based on eutrophication, EDOs will be developed for all parameters separately.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 30
CHAPTER 4 MIXING ZONE ANALYSIS
4.1 Methodology
4.1.1 Definition of Mixing Zone
A mixing zone is the portion of the receiving water where effluent dilution occurs. In general, the
receiving water as a whole will not be exposed to the immediate effluent concentration at the end‐
of‐pipe but to the effluent mixed and diluted with the receiving water. Effluent does not
instantaneously mix with the receiving water at the point of discharge. Depending on conditions
like ambient currents, wind speeds, tidal stage and wave action, mixing can take place over a large
area – up to the point where there is no measureable difference between the receiving water and
the effluent mixed with receiving water.
The mixing process can be characterized into two distinct phases: near‐field and far‐field. Near‐
field mixing occurs at the outfall and is influenced by the configuration of the outfall (e.g. pipe size,
diffusers, etc.). Far‐field mixing is influenced by receiving water characteristics like turbulence, wave
action, and stratification of the water column.
Within the mixing zone, EQOs may be exceeded but acutely toxic conditions are not permitted
unless it is determined that un‐ionized ammonia is the cause of toxicity. If the un‐ionized ammonia
concentration is the cause of toxicity, there may be an exception (under the WSER) if the
concentration of un‐ionized ammonia is less than or equal to 0.016 mg/L, expressed as N, at any
point that is 100 m from the discharge point. Outside of the mixing zone, EQOs must be achieved.
The effluent is also required to be non‐chronically toxic outside of the mixing zone. The allocation of
a mixing zone varies from one substance to another – degradable substances are allowed to mix in a
portion of the receiving water whereas toxic, persistent, and bio‐accumulative substances (such as
chlorinated dioxins and furans, PCBs, mercury and toxaphene) are not allowed a mixing zone.
A number of general criteria for allocating a mixing zone are recommended in the Strategy, including the
following:
The dimensions of a mixing zone should be restricted to avoid adverse effects on the designated
uses of the receiving water system (i.e., the mixing zone should be as small as possible);
Conditions outside of the mixing zone should be sufficient to support all of the designated uses
of the receiving water system;
A zone of passage for mobile aquatic organisms must be maintained;
Placement of mixing zones must not block migration into tributaries;
Harbour Engineering Joint Venture Glace Bay WWTP ERA 31
Changes to the nutrient status of the water body as a result of an effluent discharge should be
avoided; eutrophication or toxic blooms of algae are unacceptable impacts;
Mixing zones for adjacent wastewater discharges should not overlap; and
Adverse effects on the aesthetic qualities of the receiving water system (e.g. odour, colour,
scum, oil, floating debris) should be avoided (CCME, 2008).
The limits of the mixing zone may be defined for the following three categories of aquatic
environments based on their physical characteristics:
streams and rivers;
lakes, reservoirs and enclosed bays; and
estuarine and marine waters.
Where several limits are in place, the first one to be reached sets the maximum extent of the mixing
zone allowed for the dilution assessment. Nutrients and fecal coliforms are not allocated any
maximum dilution. For fecal coliforms, the location of the water use must be considered and
protected by the limits of the mixing zone.
Based on these general guidelines, mixing zone extents must be defined on a case‐by‐case basis that
account for local conditions. It may also be based on arbitrary mixing zone limits for open water
discharges, e.g. a 100 m (Environment Canada, 2006) or 250 m (NB DOE, 2012) radius from the
outfall and/or a dilution limit. A Draft for Discussion document “Mixing Zone Assessment and
Report Templates” dated July 7, 2016, prepared by a committee of representatives of the
environment departments in Atlantic Canada, provides guidance regarding mixing zones for ERAs in
the Atlantic Provinces. This document recommends that for ocean and estuary receiving waters a
maximum dilution limit of 1:1000 be applied for far‐field mixing.
Finally, the assessment shall be based on ‘critical conditions’. For example, in the case of a river
discharge (not applicable here), ‘critical conditions’ can be defined as the seven‐day average low
river flow for a given return period. For ocean discharges, we propose to use a maximum one‐day
average effluent concentration at the edge of the mixing zone. The Standard Method provides the
following guidance on EDO development:
“…reasonable and realistic but yet protective scenarios should be used. The objective is to simulate
the critical conditions of the receiving water, where critical conditions are where the risk that the
effluent will have an effect on the receiving environment is the highest – it does not mean using the
highest effluent flow, the lowest river flow and the highest background concentration
simultaneously.”
As a plausible worst‐case condition is used for the receiving water, the WWTP effluent will be
modelled based on an annual average flow, rather than a maximum daily or hourly flow, as applying
a critical high flow condition for the effluent simultaneously with a worst case condition in the
receiving water would result in overly conservative EDOs as this scenario doesn’t provide a
reasonable or realistic representation of actual conditions.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 32
4.1.2 Site Summary
The WWTP was first assumed to discharge through an outfall pipe perpendicular to the shoreline in
shallow water, extended to a depth estimated at ‐1.0 m below low tide (base condition). The
modelled dilution for the base condition was significantly limited by the presence of the breakwater.
Subsequent model runs were completed with a variety of outfall extensions to obtain sufficient
dilution so that the calculated EDOs would be reasonably attainable. The selected scenario assumed
that the effluent discharged through an outfall pipe perpendicular to the shoreline in shallow water,
extended to a depth estimated at ‐3.8 m below low tide based on a 100 m outfall extension. The low
tide and depth contours were estimated based on navigation charts. The total average effluent
discharge is modeled as a continuous point source of 14,200 m3/day.
The major coastal hydrodynamic features of the area are as follows:
Along‐shore currents along the open coastline are in phase with the tide, i.e. the current
speed peaks at high and low tide; and
At the outfall site, breaking waves and associated longshore currents will contribute to
effluent dispersion during storms. For this assessment, we have assumed calm summer
conditions (i.e. no waves), when effluent dilution would be at a minimum.
4.1.3 Far‐Field Modeling Approach and Inputs
The local mixing zone is limited by the water depth at the extended outfall of approximately ‐3.8 m
Chart Datum and by the presence of the shoreline. Since the outfall is in shallow water, the buoyant
plume will always reach the surface upon release from the outfall (Fisher et al., 1979). Far‐field
mixing will then be determined by ambient currents, which is best simulated with a hydrodynamic
and effluent dispersion model.
We implemented a full hydrodynamic model of the receiving coastal waters using the Danish
Hydraulic Institute’s MIKE21 model. MIKE21 is ideally suited to the study of outfall discharges in
shallow coastal areas where complex tidal and wind‐driven currents drive the dispersion process.
The model was developed using navigation charts, tidal elevations and wind observations for the
area. A similar model had been used by CBCL for CBRM in the past:
In 2005 for the assessment of the past wastewater contamination problem at Dominion
Beach, which led to the design of the WWTP at Dominion (CBCL, 2005); and
In 2014 for ERAs at the Dominion and Battery Point WWTPs.
The hydrodynamic model was calibrated to the following bottom current meter data:
1992 current meters (4 locations) located in 10 m‐depth for the study by ASA (ASA, 1994)
on local oceanography and effluent dispersion; and
2006 current meters (2 locations) off the Donkin peninsula for the CBCL study of mine
effluent dispersion.
Calibration consisted of adjusting the following parameters:
Bottom friction; and
Model spatial resolution in the area of the current meters.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 33
Numerical model domain with locations of current meter observations and modeled outfall location
are shown in Figure 4.1. Inputs and calibrated outputs are shown in Figure 4.2. The modelled
current magnitudes at New Waterford, Glace Bay and Donkin are in relatively good agreement with
observations, which is satisfactory to assess the overall dilution patterns of effluent from the outfall.
The effect of waves was not included in the model, and therefore the modeled effluent
concentration near the outfall is expected to be conservatively high.
Figure 4.1 Numerical Model Domain with Locations of Current Meter Observations (squares)
and Modeled Outfall Location (black circle)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 34
Figure 4.2 Time‐series of Hydrodynamic Model Inputs and Calibration Outputs
Harbour Engineering Joint Venture Glace Bay WWTP ERA 35
4.1.4 Modeled Effluent Dilution
Snapshots of typical modeled effluent dispersion patterns are shown on Figures 4.3 and 4.4 for the
base condition and 100 m outfall extension. Statistics on effluent concentrations were performed
over the 1‐month model run, and over a running 7‐day and 1‐day averaging period. Composite
images of maximum and average effluent concentrations are shown on Figures 4.5 and 4.6.
Effluent concentration peaks at any given location are short‐lived because the plume is changing
direction every few hours depending on tides and winds. Therefore, a representative dilution
criteria at the mixing zone limit is best calculated using an average value. We propose to use the
one‐day average effluent concentration criteria over the one‐month modeling simulation that
includes a representative combination of site‐specific tides and winds.
The dilution of the effluent plume is dependent on the outfall extension length due to its proximity
to the breakwaters located at Glace Bay. Generally the diluted effluent plume was found to reach
the shoreline north‐west of the outfall as well as the shoreline to the east of the harbour. Large
eddies tend to form due to the circulation patterns within the region. It was noted that the effluent
would travel into the harbour. The 100 m distance from the outfall to the shoreline is within the
brackets of mixing zone radiuses defined by various guidelines. We propose that this distance be
used as mixing zone limit.
For the first model scenario where the outfall was extended until the top of the outfall was 1 m
below low water level, the maximum 1‐day average effluent concentration 100 m away from the
outfall over the simulation period is 21.94%, corresponding to a dilution factor of 4.56:1.
Table 4.1 Modelled Dilution Values 100 and 200 m away from the Outfall (Existing Location)
Distance
away from
the outfall
Hourly maximum
effluent
concentration
Maximum 1‐day
average effluent
concentration
Maximum 7‐day
average effluent
concentration
1‐Month average
effluent
concentration
100 m 33.35 % (3.0:1
Dilution)
21.94 % (4.56:1
Dilution)
15.51 % (6.45:1
Dilution)
7.36 % (13.59:1
Dilution)
200 m 30.09 % (3.32:1
Dilution)
13.22 % (7.56:1
Dilution)
9.09% (11.00:1
Dilution)
9.08 % (11.01:1
Dilution)
Extensions to the current outfall were examined to ensure that the effluent concentration was
suitably diluted at the edge of a 100 m mixing zone, and the results are presented in Table 4.2.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 36
Table 4.2 Modelled Dilution Values 100 m away from the Outfall for Outfall Extensions of 50
to 500 m
Outfall
Extension
Distance
Hourly maximum
effluent
concentration
Maximum 1‐day
average effluent
concentration
Maximum 7‐day
average effluent
concentration
1‐Month average
effluent
concentration
50 m 18.72 % (5.34:1
Dilution)
10.33 % (9.68:1
Dilution)
6.34 % (15.77:1
Dilution)
4.88 % (20.49:1
Dilution)
100 m 15.97 % (6.26:1
Dilution)
4.06 % (24.63:1
Dilution)
3.57 % (28.01:1
Dilution)
2.55 % (39.22:1
Dilution)
150 m 22.24 % (4.50:1
Dilution)
7.4 % (13.51:1
Dilution)
3.77 % (26.53:1
Dilution)
2.77 % (36.10:1
Dilution)
200 m 26.46 % (3.78:1
Dilution)
3.83 % (26.11:1
Dilution)
2.72 % (36.76:1
Dilution)
2.60 % (38.46:1
Dilution)
300 m 31.39 % (3.19:1
Dilution)
5.07 % (19.72:1
Dilution)
2.48 % (40.32:1
Dilution)
2.00 % (50:1 Dilution)
400 m 24.40 % (4.10:1
Dilution)
2.16 % (46.30:1
Dilution)
1.08 % (92.59:1
Dilution)
0.96 % (104.17:1
Dilution)
500 m 12.51 % (7.99:1
Dilution)
1.5 % (66.67:1
Dilution)
0.83 % (120.48:1
Dilution)
0.61 % (163.93:1
Dilution)
Based on preliminary analysis, an outfall extension of 100 m has been assumed in order to obtain a
level of dilution that results in EDOs that are considered to be reasonably attainable. However, as
phosphorus is the parameter that appears to be driving the need for an outfall extension, additional
evaluation should be conducted during detailed design in conjunction with discussions with NSE to
determine what is required.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 37
Figure 4.3 Snapshots of Typical Modeled Effluent Dispersion Patterns (base condition)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 38
Figure 4.4 Snapshots of Typical Modeled Effluent Dispersion Patterns for 100 m Outfall
Extension
Harbour Engineering Joint Venture Glace Bay WWTP ERA 39
Figure 4.5 Composite Images of Modeled Maximum 1‐day Average (top) and Maximum 7‐
Day Average Effluent Concentrations (middle) with Concentration Time‐Series (bottom) for 100 m
outfall extension Note: 100‐m radius (black) and 200‐m radius (grey) circle shown around outfall
Harbour Engineering Joint Venture Glace Bay WWTP ERA 40
Figure 4.6 Composite Images of Modeled Maximum 1‐Day Average Effluent Concentrations
at Tablehead Beach (top) and Big Glace Bay Beach (bottom), primary contact recreation areas
Note: 100‐m radius (black) and 200‐m radius (grey) circle shown around outfall. Red circle denotes primary
contact recreation areas
Harbour Engineering Joint Venture Glace Bay WWTP ERA 41
CHAPTER 5 EFFLUENT DISCHARGE OBJECTIVES
5.1 The Need for EDOs
Effluent Discharge Objectives (EDOs) represent the effluent substance concentrations that will protect
the receiving environment and its designated water uses. They describe the effluent quality necessary
to allow the EQOs to be met at the edge of the mixing zone. The EQOs are established in Chapter 3; see
Table 3.8 for summary of results.
EDOs should be calculated where reasonable potential of exceeding the EQOs at the edge of the mixing
zone has been determined. Typically, substances with reasonable potential of exceeding the EQOs have
been selected according to the simplified approach: If a sample result measured in the effluent exceeds
the EQO, an EDO is determined. As only one sample event was collected from each outfall, rather than a
full year of effluent characterization, EDOs will be developed for all substances of potential concern that
were detected in at least one sample, and for which an EQO was identified.
5.2 Physical/ Chemical/ Pathogenic EDOs
For this assessment, EDOs were calculated using the dilution values obtained at the proposed
average design flow of 14,200 m3/day with a proposed 100 m outfall extension. This resulted in a
dilution of 24.63:1 at the edge of a 100 m mixing zone. The model shows a dilution of 2500:1 at Big
Glace Bay Beach and 169:1 at Table Head Beach (primary contact recreation areas) based on the
maximum 1‐day average concentration.
Parameters for which there is a WSER criteria were not allowed any dilution and therefore the EDO
equals the WSER Criteria. The Standard Method does not allocate any maximum dilution for
nutrients and fecal coliforms. For nutrients, it recommends a case‐by‐case analysis. For fecal
coliforms, the location of the water use must be protected by the limits of the mixing zone.
The dilution values were used to obtain an EDO by back‐calculating from the EQOs. When the
background concentration of a substance was less than the detection limit, the background
concentration was not included in the calculation of the EDO.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 42
5.3 Effluent Discharge Objectives
Substances of concern for which an EDO was developed are listed in Tables 5.1 below with the
associated EQO, maximum measured wastewater concentration, and the associated EDO. The
effluent is also required to be non‐acutely toxic at the end of pipe, and non‐chronically toxic at the
edge of the mixing zone.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 43
Table 5.1 – Effluent Discharge Objectives at Proposed Design Conditions
Parameter Maximum
Conc. (4) Background Selected
EQO Source Dilution
Factor EDO(1)
CBOD5 (mg/L)(1) 130 <5.0 25 WSER ‐ 25
Total NH3‐N (mg/L) 3.8 <0.05 2.7 USEPA Saltwater 24.63 66.5
TSS (mg/L)(1) 53 32 25 WSER ‐ 25
TP (mg/L) 2.2 0.035 0.1 CGF, Marine 24.63 1.6
TN (mg/L) 16 0.233 1 CGF, Marine 24.63 19.1
Un‐ionized NH3 (mg/L)(1) 0.0207 <0.0007 1.25 WSER ‐ 1.25
E. coli ‐ Primary Contact
(MPN/100mL)(2) 170000 69 200 HC Primary
Contact 169 22,208
E. coli ‐ Secondary Contact
(MPN/100mL) 170000 69 1000 HC Secondary
Contact 24.63 23,000
E. coli ‐ Molluscan Shellfish
(MPN/100mL) 170000 69 14 CSSP Note (3) See
Discussion
Fluoride (mg/L) 0.12 0.67 0.67 Background 24.63 0.67
Nitrate (mg/L) 1 0.038 45 CWQG Marine 24.63 1107.5
Nitrite (mg/L) 0.83 <0.001 0.06 CWQG Freshwater 24.63 1.48
Free Cyanide (mg/L) 0.013(5) <0.0010 0.001 USEPA Saltwater 24.63 0.025
Aluminum (mg/L) 0.66 0.274 0.274 Background 24.63 0.274
Cadmium (mg/L) 0.00036 <0.00005 0.00012 CWQG Marine 24.63 0.003
Copper (mg/L) 0.015 0.00047 0.0037 USEPA Saltwater 24.63 0.080
Iron (mg/L) 1 0.393 0.393 Background 24.63 0.393
Lead (mg/L) 0.0029 0.000225 0.0085 USEPA Saltwater 24.63 0.204
Manganese (mg/L) 0.75 0.015 0.1 BCMOE WWQG 24.63 2.11
Molybdenum (mg/L) 0.0065 0.0091 0.073 CWQG Freshwater 24.63 1.58
Nickel (mg/L) 0.011 <0.0002 0.0083 USEPA Saltwater 24.63 0.204
Uranium (mg/L) 0.00017 0.00253 0.015 CWQG Freshwater 24.63 0.310
Zinc (mg/L) 0.11 0.00095 0.086 USEPA Saltwater 24.63 2.10
Mercury (mg/L) 0.000013 0.000013 0.000016 CWQG Marine ‐ 0.000016
Acenaphthene (µg/L) 0.015 <0.010 6 BCMOE AWQG 24.63 147.8
Anthracene (µg/L) 0.037 <0.010 0.012 CWQG Freshwater 24.63 0.296
Benzo(a)anthracene (µg/L) 0.09 <0.010 0.018 CWQG Freshwater 24.63 0.44
Benzo(a)pyrene (µg/L) 0.064 <0.010 0.015 CWQG Freshwater 24.63 0.369
Chrysene (µg/L) 0.073 <0.010 0.1 BCMOE AWQG 24.63 2.463
Fluoranthene (µg/L) 0.21 <0.010 0.04 CWQG Freshwater 24.63 0.99
Fluorene (µg/L) 0.02 <0.010 12 BCMOE AWQG 24.63 295.56
Phenanthrene (µg/L) 0.12 <0.010 0.4 CWQG Freshwater 24.63 9.85
Pyrene (µg/L) 0.16 <0.010 0.025 CWQG Freshwater 24.63 0.62
Chloroform (µg/L) 5 <1.0 1.8 CWQG Freshwater 24.63 44
Toluene (µg/L) 1.3 <1.0 215 CWQG Marine 24.63 5295
Phenols (mg/L) 0.017 0.0305 0.0305 Background 24.63 0.03
Notes:
(1) For parameters where the EQO is based on the WSER, no dilution is permitted.
(2) Dilution at Table Head and Big Glace Bay Beaches of 169:1 and 2500:1, respectively.
(3) Existing closure zone boundary is outside the limits of the plume.
(4) Maximum concentration of existing wastewater samples.
(5) Maximum wastewater concentration based on total cyanide.
Yellow highlight indicates the maximum measured concentration exceeds the EQO; orange highlight indicates the
maximum measured concentration exceeds the EDO
Harbour Engineering Joint Venture Glace Bay WWTP ERA 44
Based on the EDOs calculated based in the current Average Daily Flow, sample results for the
following parameters exceeded the EDO in at least one wastewater characterization sample:
CBOD;
TSS;
Total Phosphorus;
E. coli;
Aluminum, and
Iron.
Some of these parameters will be reduced through treatment. In addition, the above list is based on
a single sample exceedance at any one of the outfall locations, which may not reflect the results
obtained when all of the individual outfalls are intercepted and combined. Further, some of the
EQOs were based on published water quality guidelines that may be overly stringent for a marine
receiving environment, due to a lack of a more appropriate guideline. Comments on each
parameter in the list above is provided below:
CBOD, TSS, and E. coli
These parameters will meet the EDOs at the discharge of the new WWTP through treatment.
Total Phosphorus
The total phosphorous EDO of 1.6 mg/L will likely not be consistently obtained with secondary
treatment. Options to ensure that the EDO is met would include additional treatment, or an outfall
extended into deeper water to obtain more dilution. Both of these options would come with a cost
that is not insignificant. The total phosphorous EQOs is based on the prevention of eutrophication,
which is typically not a major concern in a marine receiving environment. Consideration should be
given to the cost versus benefit of achieving these EDOs.
Aluminum
The EDO for aluminum was equal to the background concentration of 0.274 mg/L as the background
concentration was greater than the generic EQO of 0.1 mg/L. However, this EQO is likely overly
conservative as it is based on the CCME CWQG for the protection of aquatic life for freshwater.
There is no CCME CWQG for marine waters. There is no US EPA or BC MOE salt water quality
criterion for aluminum. Therefore, the CCME freshwater guideline was utilized in the absence of a
more appropriate guideline. However, use of the background value for the EDO results in no dilution
being available. In addition, some aluminum removal will likely occur during treatment.
Iron
The EDO for iron was equal to the background concentration of 0.393 mg/L as the background value
was greater than the generic EQO of 0.3 mg/L. However, this EQO is likely overly conservative as it
is based on the CCME CWQG for the protection of aquatic life for freshwater. There is no CCME
CWQG for marine waters. There is no US EPA or BC MOE salt water quality criterion for iron.
Therefore, the CCME freshwater guideline was utilized in the absence of a more appropriate
guideline. However, use of the background value for the EDO results in no dilution being available.
In addition, some iron removal will likely occur during treatment.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 45
CHAPTER 6 COMPLIANCE MONITORING
The Standard Method utilizes the results of the ERA to recommend parameters for compliance
monitoring according to the following protocol:
The WSER requirements for TSS, CBOD and unionized ammonia must be monitored to
ensure they are continuously being achieved. Minimum monitoring frequencies are
specified in the guidelines based on the size of the facility. Monitoring of these
substances cannot be reduced or eliminated;
Nutrients, such as phosphorus and ammonia, and pathogens for which an EDO was
developed should be included in the monitoring program with the same sampling
frequency as TSS and CBOD5;
For additional substances, the guidelines require that all substances with average effluent
values over 80% of the EDO be monitored;
If monitoring results for the additional substances are consistently below 80% of the EDO,
the monitoring frequency can be reduced;
If average monitoring results subsequently exceed 80% of the EDO, monitoring frequency
must return to the initial monitoring frequency; and
If monitoring results are below 80% of the EDO for at least 20 consecutive samples spread
over a period of at least one‐year, monitoring for that substance can be eliminated.
Although the Standard Method results in recommending parameters for compliance monitoring, the
provincial regulator ultimately stipulates the compliance monitoring requirements as part of the
Approvals to Operate. In New Brunswick, the New Brunswick Department of Environment and Local
Government has been using the results of the ERA to update the compliance monitoring program
listed in the Approval to operate when the existing Approvals expire. At this time, it is premature to
use the results of this ERA to provide recommendations on parameters to monitor for compliance,
as the purpose of this ERA was to provide design criteria for design of a new WWTP.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 46
CHAPTER 7 REFERENCES
ASA Consulting Limited (1994). “Industrial Cape Breton Receiving Water Study, Phase II”. Prepared
for The Town of Glace Bay.
BC Ministry of Environment (2006). A Compendium of Working Water Quality Guidelines for
British Columbia. Retrieved from: http://www.env.gov.bc.ca/wat/wq/BCguidelines/working.html
CBCL Limited (2005). Dominion Beach Sewer Study. Prepared for CBRM.
CCME (2008). Technical Supplement 3. Canada‐wide Strategy for the Management of Municipal
Wastewater Effluent. Standard Method and Contracting Provisions for the Environmental Risk
Assessment.
CCME (2007). Canadian Guidance Framework for the Management of Nutrients in Nearshore
Marine Systems Scientific Supporting Document.
CCME Canadian Environmental Quality Guidelines Summary Table. Water Quality Guidelines for the
Protection of Aquatic Life.
Environment Canada (2006). Atlantic Canada Wastewater Guidelines Manual for Collection,
Treatment, and Disposal
Environment Canada (Environment Canada) (1999). Canadian Environmental Protection Act Priority
Substances List II – Supporting document for Ammonia in the Aquatic Environment. DRAFT –August
31, 1999.
Fisher et al. (1979). Mixing in Inland and Coastal Waters. Academic Press, London.
Fisheries Act. Wastewater Systems Effluent Regulations. SOR/2012‐139.
Health Canada (2012). Guidelines for Canadian Recreational Water Quality. Retrieved from:
http://www.hc‐sc.gc.ca/ewh‐semt/pubs/water‐eau/guide_water‐2012‐guide_eau/index‐eng.php
Mixing Zone Assessment and Report Template Draft only – For discussion (July 7, 2016)
NB Department of Environment & Local Government, (2012). Memo.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 47
Thomann, Robert V. and Mueller, John A (1987). Principles of Surface Water Quality Modeling and
Control.
UMA (1994). Industrial Cape Breton Wastewater Characterization Program, Phase II.
USEPA. National Recommended Water Quality Criteria for Saltwater. Retrieved from:
http://water.epa.gov/scitech/swguidance/standards/criteria/current/index.cfm
Prepared by: Reviewed by:
Holly Sampson, M.A.Sc., P.Eng. Karen March, M.Sc.
Intermediate Chemical Engineer Environmental Scientist
Harbour Engineering Joint Venture Appendices
APPENDIX A
Laboratory Certificates
HEJV Appendices
APPENDIX C
Preliminary Design Drawings
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APR 2019182402.00
1 113
PROCESS
GENERAL
ARRANGEMENT
CAPE BRETON REGIONAL
MUNICIPALITY
GLACE BAY WASTEWATER
TREATMENT PLANT
PRELIMINARY
1 : 200
PLAN
No Description Date By
A ISSUED FOR 33% REVIEW
P07
j o i n t v e n t u r e
HEJV Glace Bay Wastewater System Pre‐Design Summary Report Appendices
APPENDIX C
Glace Bay Environmental Risk Assessment
182402.00 ● Report ● June 2020
Glace Bay Wastewater Treatment Plant
Environmental Risk Assessment
Final Report
Prepared by:
Prepared for:
March 2020
Final June 9, 2020 Darrin McLean Karen March Holly Sampson
Revised Draft – Revision 1 January 7, 2019 Darrin McLean Karen March Holly Sampson
Draft for Review August 29, 2018 Darrin McLean Karen March Holly Sampson
Issue or Revision Date Issued By: Reviewed By: Prepared By:
This document was prepared for the party indicated
herein. The material and information in the
document reflects HE’s opinion and best judgment
based on the information available at the time of
preparation. Any use of this document or reliance
on its content by third parties is the responsibility of
the third party. HE accepts no responsibility for any
damages suffered as a result of third party use of
this document.
182402.00
March 27, 2020
182402 RE 001 DRAFT WWTP ERA GLACE BAY_FINAL.DOCX/mk
ED: 09/06/2020 12:54:00/PD: 09/06/2020 12:55:00
June 9, 2020
Matt Viva, P.Eng.
Manager Wastewater Operations
Cape Breton Regional Municipality (CBRM)
320 Esplanade,
Sydney, NS B1P 7B9
Dear Mr. Viva:
RE: Glace Bay Wastewater Treatment Plant ERA
Enclosed, please find a copy of the Environmental Risk Assessment (ERA) Report
for the Glace Bay Wastewater Treatment Plant (WWTP).
The report outlines Environmental Quality Objectives (EQOs) for all parameters
of potential concern listed in the Standard Method for a “medium” facility that
were detected in the effluent. Environmental Discharge Objectives (EDOs) were
also calculated for all parameters of potential concern that were detected in the
effluent and for which an Environmental Quality Objective (EQO) was identified.
If you have any questions or require clarification on the content presented in
the attached report, please do not hesitate to contact us.
Yours very truly,
Harbour Engineering
Prepared by: Reviewed by:
Holly Sampson, M.A.Sc., P.Eng. Karen March, M.Sc.
Intermediate Chemical Engineer Environmental Scientist
Direct: 902‐539‐1330 Phone: 902‐450‐4000
E‐Mail: hsampson@cbcl.ca E‐Mail: kmarch@dillon.ca
Project No: 182402.00 (CBCL)
187116.00 (Dillon)
March 27, 2020
Harbour Engineering Joint Venture Glace Bay WWTP ERA i
Contents
CHAPTER 1 Background and Objectives ................................................................................... 1
1.1 Introduction .................................................................................................................. 1
1.2 Background ................................................................................................................... 1
1.3 Facility Description ........................................................................................................ 2
CHAPTER 2 Initial Effluent Characterization ............................................................................. 5
2.1 Substances of Potential Concern .................................................................................. 5
2.1.1 Whole Effluent Toxicity ..................................................................................... 7
2.2 Wastewater Characterization Results .......................................................................... 7
CHAPTER 3 Environmental Quality Objectives ....................................................................... 12
3.1 Water Uses .................................................................................................................. 12
3.2 Ambient Water Quality ............................................................................................... 13
3.3 Physical/ Chemical/ Pathogenic Approach ................................................................. 19
3.3.1 General Chemistry/ Nutrients ........................................................................ 19
3.3.2 Metals ............................................................................................................. 24
3.3.3 E. coli ............................................................................................................... 26
3.3.4 Summary ......................................................................................................... 28
CHAPTER 4 Mixing Zone Analysis ........................................................................................... 30
4.1 Methodology ............................................................................................................... 30
4.1.1 Definition of Mixing Zone ............................................................................... 30
4.1.2 Site Summary .................................................................................................. 32
4.1.3 Far‐Field Modeling Approach and Inputs ....................................................... 32
4.1.4 Modeled Effluent Dilution .............................................................................. 35
CHAPTER 5 Effluent Discharge Objectives .............................................................................. 41
5.1 The Need for EDOs ...................................................................................................... 41
5.2 Physical/ Chemical/ Pathogenic EDOs ........................................................................ 41
5.3 Effluent Discharge Objectives ..................................................................................... 42
CHAPTER 6 Compliance Monitoring ....................................................................................... 45
CHAPTER 7 References .......................................................................................................... 46
Appendices
A Laboratory Certificates
Harbour Engineering Joint Venture Glace Bay WWTP ERA 1
CHAPTER 1 BACKGROUND AND OBJECTIVES
1.1 Introduction
Harbour Engineering (HE) was engaged by the Cape Breton Regional Municipality (CBRM) to complete
an Environmental Risk Assessment (ERA) for the proposed Glace Bay Wastewater Treatment Plant
(WWTP). As this is a proposed WWTP that has not yet been designed, this ERA was completed with the
objective that it serve as a tool to establish effluent criteria for the design of a new WWTP. For this
reason, the ERA was completed without the frequency of testing required by the Standard Method
outlined in Technical Supplement 3 of the Canada‐wide Strategy for the Management of Municipal
Wastewater Effluent (Standard Method) for initial effluent characterization. With the exception of the
initial effluent characterization sampling frequency, the ERA was otherwise completed in accordance
with the Standard Method.
1.2 Background
The Canada‐wide Strategy (CWS) for the Management of Municipal Wastewater Effluent was adopted
by the Canadian Council of Ministers of the Environment (CCME) in 2009. The Strategy is focused on
two (2) main outcomes: Improved human health and environmental protection; and improved clarity
about the way municipal wastewater effluent is managed and regulated. The Strategy requires that all
wastewater facilities discharging effluent to surface water meet the following National Performance
Standards (NPS) as a minimum:
Carbonaceous Biochemical Oxygen Demand for five days (CBOD5) – 25 mg/L;
Total Suspended Solids (TSS) – 25 mg/L; and
Total Residual Chlorine (TRC) – 0.02 mg/L.
The Wastewater Systems Effluent Regulations (WSER) came into effect in 2012 under the Fisheries Act.
The WSER include the above NPS as well as the following criteria:
Unionized ammonia ‐ 1.25 mg/L, expressed as nitrogen (N), at 15°C ± 1°C.
The CWS requires that facilities develop site‐specific Environmental Discharge Objectives (EDOs) to
address substances not included in the NPS that are present in the effluent. EDOs are the substance
concentrations that can be discharged in the effluent and still provide adequate protection of human
health and the environment. They are established by conducting a site‐specific ERA. The ERA includes
characterization of the effluent to determine potential substances of concern, and characterization of
the receiving water to determine beneficial water uses, ambient water quality, assimilative capacity, and
Harbour Engineering Joint Venture Glace Bay WWTP ERA 2
available dilution. A compliance monitoring program is then developed and implemented to ensure
adherence to the established EDOs for the facility.
1.3 Facility Description
The proposed Glace Bay Wastewater Treatment Plant (WWTP) will be constructed at Lower Main
Street near Glace Bay Harbour. Treated effluent will be discharged to the Atlantic Ocean at the
location of the existing outfall near the breakwater (Figure 1.2).
Figure 1.1 Site Location
Harbour Engineering Joint Venture Glace Bay WWTP ERA 3
Figure 1.2 WWTP Location
The service population of Glace Bay is 14,536 people in 7,258 residential units. The theoretical
domestic wastewater flow (exclusive of inflow and infiltration (I&I)) is an average of 4,942 m3/day
with a peak of 13,838 m3/day based on a per capita flow of 340 L/person/day and a peaking factor
of 2.8 calculated using the Harmon formula.
There are currently 8 existing outfalls (see Figure 3.1). These outfalls will be consolidated into one
discharge at the location of existing GB‐8 outfall. The estimated service population associated with
each outfall, based on 2016 census data, is provided in Table 1.1:
Table 1.1 Service Population by Outfall
Outfall Name Residential Units Population
GB1 253 558
GB2 231 504
GB3 21 44
GB4A 306 590
GB4B 36 77
GB5 57 118
GB6 347 713
GB7 72 140
GB8 5935 11791
Total 7258 14536
Harbour Engineering Joint Venture Glace Bay WWTP ERA 4
For the purpose of the ERA, the average daily flow was assumed to be 14,200 m3/day (215 IG/p/day
or 1m3/p/day) for modelling purposes, based on a reasonable per capita allowance for average
annual flow. The preliminary design of the proposed WWTP was subsequently completed based on
an average design flow of 13,815 m3/day. The effluent modelling will not be updated at this time.
See the WWTP preliminary design report for information on the development of design flows. The
design flows do not account for growth. CBRM has a declining population so increased flows due to
population growth are not expected. CBRM’s wastewater collection systems have significant inflow
and infiltration (I&I), and CBRM plans to implement an I&I reduction program.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 5
CHAPTER 2 INITIAL EFFLUENT CHARACTERIZATION
2.1 Substances of Potential Concern
An initial characterization program covering a one‐year period is typically required by the Standard
Method to describe the treated effluent and identify substances of concern. As there is no existing
WWTP for this system, and the ERA is being conducted for the purpose of determining effluent
objectives for the design of a new WWTP, one sample event was completed for each of the existing
8 outfalls. Sample results for some of the parameters of potential concern were also available from
three‐years of sampling conducted by CBRM from 2015 through 2017 at the GB4 outfall, one sample
collected by Dillon Consulting in 2014 at each of the outfalls, and samples collected by UMA
Engineering in 1992 at the Park Street sewer. Substances of potential concern are listed in the
Standard Method based on the size category of the facility. The proposed design capacity of the new
WWTP will be finalized during the pre‐design study, but for the purposes of the draft ERA, an
average annual flow of 14,200 m3/day will be assumed based on a per capita flow of 215 IG/p/day
(1m3/p/day). Therefore, the WWTP is classified as a “medium” facility based on an average daily
flow rate that is between 2,500 and 17,500 m3/day.
The substances of potential concern for a “medium” facility, as per the Standard Method, are
detailed in Table 2.1. There were no additional substances of concern identified to be monitored as
industrial input does not exceed 5% of total dry weather flow in the sewer shed, on an annual
average basis. There is one hospital and a fish processing plant, but the flows are expected to be
much less than 5% of the wastewater flow for the system.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 6
Table 2.1 – Substances of Potential Concern for a Medium Facility
Test Group Substances
General Chemistry
/ Nutrients
Fluoride
Nitrate
Nitrate + Nitrite
Total Ammonia Nitrogen
Total Kjeldahl Nitrogen (TKN)
Total Phosphorus (TP)
Total Suspended Solids (TSS)
Carbonaceous Biochemical Oxygen Demand (CBOD5)
Total Residual Chlorine (TRC)
Chemical Oxygen Demand (COD)
Cyanide (total)
pH
Temperature
Metals
Aluminum, barium, beryllium, boron, cadmium, chromium, cobalt, copper, iron,
lead, manganese, molybdenum, nickel, silver, strontium, thallium, tin, titanium,
uranium, vanadium, zinc as well as arsenic, antimony, selenium and mercury
Pathogens E. coli (or other pathogen, as directed by the jurisdiction)
Organochlorine
Pesticides
Alpha‐BHC, endosulfin (I and II), endrin, heptachlor epoxide, lindane (gamma‐
BHC), mirex, DDT, methoxychlor, aldrin, dieldrin, heptachlor, a‐chlordane and g‐
chlordane, toxaphene
Polychlorinated
Biphenyls (PCBs) Total PCBs
Polycyclic Aromatic
Hydrocarbons
(PAHs)
Acenaphthene, acenapthylene, anthracene, benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene, benzo(g,h,i)perylene,
benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, fluorene,
indeno(1,2,3‐cd)pyrene, methylnaphthalene, naphthalene, phenanthrene, pyrene
Volatile Organic
Compounds (VOCs)
Benzene, bromodichloromethane, bromoform, carbon tetrachloride,
chlorobenzene, chlorodibromomethane, chloroform, 1,2‐dichlorobenzene, 1,4‐
dichlorobenzene, 1,2‐dichloroethane, 1,1‐dichloroethene, dichloromethane,
ethylbenzene, 1,1,1,2‐tetrachloroethane, 1,1,2,2‐tetrachloroethane,
tetrachloroethene, toluene, trichloroethene, vinyl chloride, m/p‐xylene, o‐xylene
Phenolic
Compounds
2,3,4,6‐tetrachlorophenol, 2,4,6‐trichlorophenol, 2,4‐dichlorophenol,
pentachlorophenol
Surfactants Non‐ionic surfactants and anionic surfactants (others may be added by the
jurisdiction)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 7
2.1.1 Whole Effluent Toxicity
Wastewater effluent potentially contains a variety of unknown or unidentified substances for which
guidelines do not exist. In order to adequately protect against these unknown substances, Whole
Effluent Toxicity (WET) tests are typically conducted to evaluate acute (short‐term) and chronic (long‐
term) effects.
The Standard Method requires the following toxicity tests be conducted quarterly:
Acute toxicity – Rainbow Trout and Daphnia magna; and
Chronic Toxicity – Ceriodaphnia dubia and Fathead Minnow.
A draft for discussion Mixing Zone Assessment and Report Template, dated July 6, 2016 that was
prepared by a committee of representatives of the environment departments in Atlantic Canada noted
that only Ceriodaphnia dubia testing is required for chronic toxicity. If the test does not pass, a fathead
minnow test is required.
As the wastewater in this system is currently untreated, and the purpose of the ERA is to determine
effluent discharge objectives for the design of a new WWTP, no WET tests were conducted at this time.
2.2 Wastewater Characterization Results
The results of the initial wastewater characterization program completed by HE are summarized in
Tables 2.2 through 2.6. One sample was collected for each outfall in the system as part of the initial
wastewater characterization study. Outfall locations are shown in Section 3.
Table 2.2 – Initial Wastewater Characterization Results – General Chemistry
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
CBOD5 (mg/L) 32 50 130 84 54 30 64
COD (mg/L) 53 100 200 120 130 41 120
Total NH3‐N (mg/L) 1.4 2.0 3.4 3.8 2.1 0.51 3.7
TSS (mg/L) 25 53 49 41 40 15 50
TP (mg/L) 0.69 0.99 2.2 1.6 1.0 0.3 1.8
TKN (mg/L) 6.0 6.8 16 12 9.2 2.2 13
pH 7.11 7.00 6.79 6.52 7.17 7.18 7.31
Un‐ionized NH3 (mg/L)(1) 0.0049 0.0055 0.0058 0.0035 0.0085 0.0021 0.0207
E. coli (MPN/100mL) 77000 >240000 >240000 130000 >240000 170000 >240000
Fluoride (mg/L) <0.10 <0.10 0.12 0.1 0.12 <0.10 0.11
Nitrate (mg/L) 0.67 0.079 <0.050 0.08 0.79 1.0 <0.050
Nitrite (mg/L) 0.03 0.34 <0.010 0.83 0.06 0.025 <0.010
Nitrate + Nitrite (mg/L) 0.69 0.42 <0.050 0.91 0.85 1.0 <0.050
Total Nitrogen (TN) (mg/L) 6.7 7.2 16.0 12.9 10.1 3.2 13.0
Total Cyanide (mg/L) 0.0019 0.0022 0.0028 0.0034 0.0029 0.0015 0.013
Note:
(1) The values of unionized ammonia were determined in accordance with the formula in the WSER, the
concentration of total ammonia in the sample, and the pH of the sample.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 8
Table 2.3 – Initial Wastewater Characterization Results – Metals (mg/L)
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
Aluminum 0.077 0.31 0.28 0.66 0.14 0.06 0.11
Antimony <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Arsenic <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Barium 0.045 0.03 0.033 0.031 0.044 0.038 0.037
Beryllium <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Boron <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050
Cadmium 0.000038 0.00017 0.00031 0.00036 0.00013 0.00004 0.000095
Chromium <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Cobalt <0.00040 0.0012 0.0011 0.0025 0.00065 <0.00040 <0.00040
Copper 0.0047 0.0068 0.01 0.015 0.009 0.0044 0.0099
Iron 0.17 1 0.42 0.58 0.19 0.3 0.49
Lead <0.00050 0.00062 0.001 0.0029 0.00051 0.00056 0.00057
Manganese 0.12 0.75 0.4 0.56 0.32 0.29 0.25
Molybdenum <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 0.0065 <0.0020
Nickel <0.0020 0.004 0.0066 0.011 0.0031 <0.0020 <0.0020
Selenium <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010
Silver <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010
Strontium 0.16 0.12 0.12 0.16 0.13 0.28 0.11
Thallium <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010 <0.00010
Tin <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
Titanium 0.003 0.0052 0.0082 <0.020 <0.020 0.0032 0.0029
Uranium 0.00017 0.00011 <0.00010 <0.00010 0.00011 0.00015 <0.00010
Vanadium <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020 <0.0020
Zinc 0.015 0.051 0.11 0.11 0.043 0.013 0.040
Mercury <0.000013 <0.000013 <0.000013 <0.000013 0.000013 <0.000013 <0.000013
Harbour Engineering Joint Venture Glace Bay WWTP ERA 9
Table 2.4 – Initial Wastewater Characterization Results – VOCs (µg/L)
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
1,2‐Dichlorobenzene <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
1,4‐Dichlorobenzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Chlorobenzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
1,1,2,2‐Tetrachloroethane <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
1,1‐Dichloroethylene <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
1,2‐Dichloroethane <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Benzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Bromodichloromethane <1.0 1.0 1.0 1.2 1.0 <1.0 <1.0
Bromoform <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Carbon Tetrachloride <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
Chloroform 2.4 3.8 4.1 5 3.8 <1.0 3.1
Dibromochloromethane <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Ethylbenzene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Methylene Chloride
(Dichloromethane) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0
o‐xylene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
m/p‐xylene <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0
Tetrachloroethene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Toluene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.3
Trichloroethene <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Vinyl Chloride <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50
Harbour Engineering Joint Venture Glace Bay WWTP ERA 10
Table 2.5 – Initial Wastewater Characterization Results – PCBs, Phenols, PAHs
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
Total PCBs (µg/L) <0.05 <0.05 <0.3 <0.05 <0.05 <0.05 <0.05
Phenols (mg/L) 0.0051 0.0049 0.013 0.0081 0.017 0.0015 0.0011
1‐Methylnaphthalene (µg/L) <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050
2‐Methylnaphthalene (µg/L) <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050
Acenaphthene (µg/L) <0.010 <0.010 <0.050 0.015 <0.010 <0.010 <0.010
Acenaphthylene (µg/L) <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010
Anthracene (µg/L) <0.010 <0.010 <0.010 0.037 <0.010 <0.010 <0.010
Benzo(a)anthracene (µg/L) <0.010 <0.010 <0.010 0.09 <0.010 <0.010 <0.010
Benzo(a)pyrene (µg/L) <0.010 <0.010 <0.010 0.064 <0.010 <0.010 <0.010
Benzo(b)fluoranthene (µg/L) <0.010 <0.010 <0.010 0.054 <0.010 <0.010 <0.010
Benzo(g,h,i)perylene (µg/L) <0.010 <0.010 <0.010 0.04 <0.010 <0.010 <0.010
Benzo(k)fluoranthene (µg/L) <0.010 <0.010 <0.010 0.026 <0.010 <0.010 <0.010
Chrysene (µg/L) <0.010 <0.010 <0.010 0.073 <0.010 <0.010 <0.010
Dibenz(a,h)anthracene (µg/L) <0.010 <0.010 <0.010 0.021 <0.010 <0.010 <0.010
Fluoranthene (µg/L) 0.013 0.017 0.016 0.21 <0.010 <0.010 <0.010
Fluorene (µg/L) <0.010 <0.010 <0.010 0.02 <0.010 <0.010 <0.010
Indeno(1,2,3‐cd)pyrene (µg/L) <0.010 <0.010 <0.010 0.041 <0.010 <0.010 <0.010
Naphthalene (µg/L) <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20
Phenanthrene (µg/L) 0.016 0.031 0.031 0.12 0.016 <0.010 0.011
Pyrene (µg/L) 0.011 0.016 0.016 0.16 <0.010 <0.010 <0.010
Table 2.6 – Initial Wastewater Characterization Results – Organochlorine Pesticides (µg/L)
Parameter Outfall
GB1 GB2 GB4 GB5 GB6 GB7 GB8
Aldrin <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Dieldrin <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
a‐Chlordane <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
g‐Chlordane <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
o,p‐DDT <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
p,p‐DDT <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Lindane <0.003 <0.003 <0.02 <0.003 <0.003 <0.003 <0.003
Endosulfan I (alpha) <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Endosulfan II (beta) <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Endrin <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Heptachlor <0.006 <0.005 <0.03 <0.02 <0.02 <0.005 <0.005
Heptachlor epoxide <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Methoxychlor <0.01 <0.01 <0.07 <0.01 <0.01 <0.01 <0.01
alpha‐BHC <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Mirex <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Toxaphene <0.2 <0.2 <1 <0.2 <0.2 <0.2 <0.2
DDT+ Metabolites <0.005 <0.005 <0.03 <0.005 <0.005 <0.005 <0.005
Harbour Engineering Joint Venture Glace Bay WWTP ERA 11
Table 2.7 – Historical Wastewater Characterization Samples
Location Parameter Average Number of Samples
GB1
TSS (mg/L) 31 1
CBOD5 (mg/L) 48 1
Unionized Ammonia (mg/L) 0.023 1
GB2
TSS (mg/L) 55 1
CBOD5 (mg/L) 53 1
Unionized Ammonia (mg/L) 0.027 1
GB3
TSS (mg/L) 59 1
CBOD5 (mg/L) 290 1
Unionized Ammonia (mg/L) 0.330 1
GB4
TSS (mg/L) 394 27
CBOD5 (mg/L) 40 27
Total Ammonia (mg/L) 0.3 12
pH 7.4 12
Unionized Ammonia (mg/L) 0.004 13
GB5
TSS (mg/L) 110 1
CBOD5 (mg/L) 56 1
Unionized Ammonia (mg/L) 0.011 1
GB6
TSS (mg/L) 81 1
CBOD5 (mg/L) 240 1
Unionized Ammonia (mg/L) 0.009 1
GB7
TSS (mg/L) 40 1
CBOD5 (mg/L) 55 1
Unionized Ammonia (mg/L) 0.003 1
GB8
TSS (mg/L) 129 18
CBOD5 (mg/L) 105 18
Unionized Ammonia (mg/L) 0.006 1
GB8A
TSS (mg/L) 90 24
CBOD5 (mg/L) 76 24
pH 7.1 24
Alkalinity (mg/L) 100 4
TKN (mg/L) 23.9 4
Total Phosphorus (mg/L) 2.40 4
Note: Location GB8A is a sample location upstream of the GB8 outfall at Park St.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 12
CHAPTER 3 ENVIRONMENTAL QUALITY OBJECTIVES
Generic Environmental Quality Objectives (EQOs) are generated from established guidelines, typically
the Wastewater Systems Effluent Regulations (WSER), the Canadian Environmental Quality Guidelines
(CEQGs) and other guidelines specified by jurisdiction. Site‐specific EQOs are established by adjusting
the generic EQOs based on site‐specific factors, particularly ambient water quality. For example, if the
background concentration of a substance is greater than the guideline value (generic EQO), the
background concentration is used as the site‐specific EQO. However, substances where the EQO is based
on the WSER are not adjusted based on ambient water quality. Furthermore, there are some guidelines
that are dependent on characteristics of the receiving water like pH or temperature.
EQOs can be determined by three different approaches:
Physical/ chemical/ pathogenic – describes the substance levels that will protect water quality;
Whole Effluent Toxicity (WET) – describes the proportion of effluent that can enter the receiving
water without causing toxicological effects (both acute and chronic); and
Biological criteria (bio‐assessment) – describes the level of ecological integrity that must be
maintained.
This assessment follows the physical/ chemical/ pathogenic approach from the Standard Method
outlined in the CCME guidelines. The bio‐assessment is not included in the Standard Method as it is still
being developed (CCME, 2008).
3.1 Water Uses
EQOs are numerical values and narrative statements established to protect the receiving water – in this
case the Atlantic Ocean near the breakwater in Glace Bay Harbour. The first step in determining EQOs is
to define the potential beneficial uses of the receiving water.
The following beneficial water uses have been identified for the Atlantic Ocean in the vicinity of Glace
Bay:
Direct contact recreational activities like swimming and wading at Table Head Beach to the
north and Big Glace Bay Beach to the south (shown on Figure 3.1, below);
Secondary contact recreational activities like boating and fishing; and
Ecosystem health for marine aquatic life.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 13
There is no molluscan shellfish harvesting zone in the vicinity of the outfall. The outfall is situated in a
closure zone boundary extending from Point Aconi to Schooner Pond, situated 2500 m offshore in the
vicinity of the outfall (shown on Figure 3.1).
Figure 3.1 Location of Existing Outfalls
3.2 Ambient Water Quality
Generic EQOs are first developed based on existing guidelines and then adjusted based on site‐
specific factors, particularly background water quality. Water quality data was obtained for two
locations in the Atlantic Ocean along the coast of Cape Breton. The locations were chosen in an
attempt to be representative of ambient water quality outside the influence of the existing
untreated wastewater discharges in CBRM. Samples were collected by HE on May 11, 2018, and the
sample locations are summarized as follows and presented in Figure 3.2. A second set of samples
was collected by HE on November 18, 2018 and analyzed for metals using a different laboratory
method due to elevated detection limits in the first set of samples.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 14
BG‐1: Near Mira Gut Beach
BG‐2: Wadden’s Cove
Figure 3.2 Ambient Water Quality Sample Locations
A third sample was collected north of Port Morien but the results were not considered
representative of background conditions as sample results indicated that the sample was impacted
by wastewater. A summary of the ambient water quality data is shown in Tables 3.1 through 3.5.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 15
Table 3.1 – Ambient Water Quality Data – General Chemistry
Parameter Units BG1 BG2 AVG
Carbonaceous BOD (CBOD) mg/L <5.0 <5.0 <5.0
COD mg/L 1100 1000 1050
Hardness mg/L 4900 5200 5050
Nitrogen (Ammonia Nitrogen) mg/L <0.050 <0.050 <0.05
TSS mg/L 58 5.0 32
Total Phosphorus (TP) mg/L 0.037 0.032 0.035
Total Kjeldahl Nitrogen (TKN) mg/L 0.19 0.20 0.20
pH pH 7.73 7.68 7.71
unionized ammonia mg/L <0.0007 <0.0007 <0.0007
E. coli MPN/100mL 52 86 69
TRC mg/L NM NM NM
Fluoride mg/L 0.67 0.67 0.67
Nitrate (N) mg/L 0.051 <0.050 0.038
Nitrite (N) mg/L <0.010 <0.010 <0.010
Nitrate + Nitrite mg/L 0.051 <0.050 0.038
Total Nitrogen (TN) mg/L 0.241 0.225 0.233
Total Cyanide mg/L <0.0010 <0.0010 <0.0010
Note:
NM = Parameter not measured.
Parameters reported as < detection limit have been included in average calculation as half the
detection limit.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 16
Table 3.2 – Ambient Water Quality Data – Metals
Parameter Units BG1 BG2 AVG
May‐11 Nov‐18 May‐11 Nov‐18
Aluminum mg/L 0.17 0.089 0.083 0.754 0.274
Antimony mg/L <0.010(2) <0.0005 <0.010(2) <0.0005 <0.0005
Arsenic mg/L <0.010 0.00163 <0.010 0.00177 0.0017
Barium mg/L <0.010 0.0074 <0.010 0.0083 0.00785
Beryllium mg/L <0.010(2) <0.001 <0.010(2) <0.001 <0.001
Boron mg/L 3.5 3.42 3.7 3.43 3.51
Cadmium mg/L <0.00010(2) <0.00005 <0.00010(2) <0.00005 <0.00005
Chromium mg/L <0.010(2) <0.0005(1) <0.010(2) 0.00056 0.00041
Cobalt mg/L <0.0040(2) <0.0001(1) <0.0040(2) 0.00031 0.00018
Copper mg/L <0.020(2) <0.0005(1) <0.020(2) 0.00068 0.00047
Iron mg/L <0.50(2) 0.159 <0.50(2) 0.626 0.393
Lead mg/L <0.0050(2) 0.00015 <0.0050(2) 0.0003 0.000225
Manganese mg/L 0.021 0.00747 <0.020(2) 0.0165 0.01499
Molybdenum mg/L <0.020(2) 0.0095 <0.020(2) 0.0086 0.0091
Nickel mg/L <0.020(2) <0.00020 <0.020(2) <0.00020 <0.00020
Selenium mg/L <0.010(2) <0.0005 <0.010(2) <0.0005 <0.0005
Silver mg/L <0.0010(2) <0.00005 <0.0010(2) <0.00005 <0.00005
Strontium mg/L 5.9 7.27 6.3 7.32 6.70
Thallium mg/L <0.0010(2) <0.00010 <0.0010(2) <0.00010 <0.00010
Tin mg/L <0.020(2) <0.001 <0.020(2) <0.001 <0.001
Titanium mg/L <0.020(2) <0.010 <0.020(2) 0.046 0.026
Uranium mg/L 0.0026 0.00248 0.0026 0.00242 0.00253
Vanadium mg/L <0.020(2) <0.01 <0.020(2) <0.01 <0.01
Zinc mg/L <0.050(2) <0.001 <0.050(2) 0.0014 0.00095
Mercury mg/L 0.000013 ‐ 0.000013 ‐ 0.000013
Note:
(1) Value included in average calculation as half the detection limit.
(2) Value omitted from average calculation due to elevated detection limit.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 17
Table 3.3 – Ambient Water Quality Data – VOCs
Parameter Units BG1 BG2 AVG
1,2‐dichlorobenzene µg/L <0.50 <0.50 <0.50
1,4‐dichlorobenzene µg/L <1.0 <1.0 <1.0
Chlorobenzene µg/L <1.0 <1.0 <1.0
1,1,2,2‐tetrachloroethane µg/L <0.50 <0.50 <0.50
1,1‐Dichloroethylene µg/L <0.50 <0.50 <0.50
1,2‐dichloroethane µg/L <1.0 <1.0 <1.0
Benzene µg/L <1.0 <1.0 <1.0
Bromodichloromethane µg/L <1.0 <1.0 <1.0
Bromoform µg/L <1.0 <1.0 <1.0
Carbon Tetrachloride µg/L <0.50 <0.50 <0.50
Chloroform µg/L <1.0 <1.0 <1.0
Dibromochloromethane µg/L <1.0 <1.0 <1.0
Ethylbenzene µg/L <1.0 <1.0 <1.0
Methylene Chloride
(Dichloromethane) µg/L <3.0 <3.0 <3.0
o‐xylene µg/L <1.0 <1.0 <1.0
m/p‐xylene µg/L <2.0 <2.0 <2.0
Tetrachloroethene
(Tetrachloroethylene) µg/L <1.0 <1.0 <1.0
Toluene µg/L <1.0 <1.0 <1.0
Trichloroethene (Trichloroethylene) µg/L <1.0 <1.0 <1.0
Vinyl Chloride µg/L <0.50 <0.50 <0.50
Harbour Engineering Joint Venture Glace Bay WWTP ERA 18
Table 3.4 – Ambient Water Quality Data – PCBs, Phenols, PAHs
Parameter Units BG1 BG2 AVG
Total PCBs µg/L <0.05 <0.05 <0.05
Phenols mg/L 0.011 <0.010 0.0305
1‐Methylnaphthalene µg/L <0.050 <0.050 <0.050
2‐Methylnaphthalene µg/L <0.050 <0.050 <0.050
Acenaphthene µg/L <0.010 <0.010 <0.010
Acenaphthylene µg/L <0.010 <0.010 <0.010
Anthracene µg/L <0.010 <0.010 <0.010
Benzo(a)anthracene µg/L <0.010 <0.010 <0.010
Benzo(a)pyrene µg/L <0.010 <0.010 <0.010
Benzo(b)fluoranthene µg/L <0.010 <0.010 <0.010
Benzo(g,h,i)perylene µg/L <0.010 <0.010 <0.010
Benzo(k)fluoranthene µg/L <0.010 <0.010 <0.010
Chrysene µg/L <0.010 <0.010 <0.010
Dibenz(a,h)anthracene µg/L <0.010 <0.010 <0.010
Fluoranthene µg/L <0.010 <0.010 <0.010
Fluorene µg/L <0.010 <0.010 <0.010
Indeno(1,2,3‐cd)pyrene µg/L <0.010 <0.010 <0.010
Naphthalene µg/L <0.20 <0.20 <0.20
Phenanthrene µg/L <0.010 <0.010 <0.010
Pyrene µg/L <0.010 <0.010 <0.010
Table 3.5 – Ambient Water Quality Data – Organochlorine Pesticides
Parameter Units BG1 BG2 AVG
Aldrin µg/L <0.005 <0.005 <0.005
Dieldrin µg/L <0.005 <0.005 <0.005
a‐Chlordane µg/L <0.005 <0.005 <0.005
g‐Chlordane µg/L <0.005 <0.005 <0.005
o,p‐DDT µg/L <0.005 <0.005 <0.005
p,p‐DDT µg/L <0.005 <0.005 <0.005
Lindane µg/L <0.003 <0.003 <0.003
Endosulfan I (alpha) µg/L <0.005 <0.005 <0.005
Endosulfan II (beta) µg/L <0.005 <0.005 <0.005
Endrin µg/L <0.005 <0.005 <0.005
Heptachlor µg/L <0.005 <0.005 <0.005
Heptachlor epoxide µg/L <0.005 <0.005 <0.005
Methoxychlor µg/L <0.01 <0.01 <0.01
alpha‐BHC µg/L <0.005 <0.005 <0.005
Mirex µg/L <0.005 <0.005 <0.005
Toxaphene µg/L <0.2 <0.2 <0.2
DDT+ Metabolites µg/L <0.005 <0.005 <0.005
Harbour Engineering Joint Venture Glace Bay WWTP ERA 19
3.3 Physical/ Chemical/ Pathogenic Approach
The physical/ chemical/ pathogenic approach is intended to protect the receiving water by ensuring that
water quality guidelines for particular substances are being met. EQOs are established by specifying the
level of a particular substance that will protect water quality. Substance levels that will protect water
quality are taken from the CEQGs associated with the identified beneficial water uses. If more than one
guideline applies, the most stringent is used. Typically, the Canadian Water Quality Guidelines (CWQGs)
for the Protection of Aquatic Life are the most stringent and have been used for this assessment. The
Health Canada Guidelines for Canadian Recreational Water have also been used to provide limits for
pathogens (E. coli).
The guidelines for the Protection of Aquatic Life provide recommendations for both freshwater and
marine (including estuarine) environments. Since the receiving water for the proposed Glace Bay
WWTP is a marine environment, the marine guidelines were used where available. The US EPA
National Recommended Water Quality Criteria (saltwater) were used when there were no CCME
marine criteria provided. For substances where a marine criterion was not specified by either CCME
or US EPA, the CCME freshwater guidelines were used. However, in marine environments, utilizing
freshwater water quality objectives may result in EQOs and EDOs that are overly conservative. There
were some parameters that were detected in the wastewater but for which a criterion did not exist
from either CCME or the US EPA. In those instances, an effort was made to identify an applicable
criterion from another jurisdiction, such as British Columbia Ministry of Environment (BCMOE).
Technical Supplement 3 of the Canada‐wide Strategy for the Management of Municipal Wastewater
Effluent indicates that for any one substance, if the natural concentration in the upstream location is
higher than the generic EQO equivalent, that concentration will apply as a site‐specific EQO, and the
generic EQO must be set aside. Otherwise, site‐specific EQOs are not needed. Background water
quality samples were collected from the Atlantic Ocean by HE on May 11, 2018 and the results were
previously summarized in Section 3.2.
Site‐specific EQOs were developed for each substance that was detected in the wastewater, for
which there was a generic EQO, and for which the background concentration exceeded the generic
EQO. Site‐specific EQOs are discussed in the following sections and included in Table 3.8. EQOs are
derived in the following sections for each substance of potential concern for a medium facility that
was detected in the wastewater.
3.3.1 General Chemistry/ Nutrients
The following general chemistry and nutrients parameters were identified as substances of potential
concern for a medium facility: CBOD, chemical oxygen demand (COD), un‐ionized ammonia, total
ammonia, total kjeldahl nitrogen (TKN), total suspended solids (TSS), total phosphorus, pH, total
residual chlorine (TRC), fluoride, nitrate, nitrite and total cyanide. EQOs for these substances are
established in the following sections.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 20
Oxygen Demand
Biochemical Oxygen Demand (BOD5) is a measure of the oxygen required to oxidize organic material
and certain inorganic materials over a given period of time (five days). It has two components:
carbonaceous oxygen demand and nitrogenous oxygen demand.
Chemical Oxygen Demand (COD) is another measure of oxygen depleting substances present in the
effluent. It is a measure of the oxygen required to chemically oxidize reduced minerals and organic
matter.
Carbonaceous Biochemical Oxygen Demand (CBOD5) measures the amount of biodegradable
carbonaceous material in the effluent that will require oxygen to break down over a given period of
time (five days). The CBOD5 discharged in wastewater effluent reduces the amount of dissolved
oxygen in the receiving water. Dissolved oxygen is an essential parameter for the protection of
aquatic life; and the higher the CBOD5 concentration, the less oxygen that is available for aquatic
life.
Traditionally performance standards have been set for BOD5; however, the WSER dictate a limit for
CBOD5. This is due to the variable effects of nitrogenous oxygen demand on the BOD5 test.
There are no CWQGs for the protection of aquatic life for CBOD5 in freshwater or in marine waters.
However, because CBOD5 affects the concentration of dissolved oxygen, the CWQG for dissolved
oxygen should be considered. The CWQG for freshwater aquatic life dictates that the dissolved
oxygen concentrations be greater than 9.5 mg/L for early life stages in cold water ecosystems. The
CWQG for marine aquatic life is a minimum of 8 mg/L.
The background dissolved oxygen concentrations were not measured in the receiving water.
However, the concentration of CBOD5 discharged in accordance with the WSER criteria should not
cause the dissolved oxygen (DO) concentration to vary outside of the normal range. Based on an
average annual temperature of 6.9 °C (from Bedford Institute of Oceanography Area 4VN), the
solubility of oxygen in seawater is approximately 9.5 mg/L. Assuming the background concentration
of DO is saturated, there can be a drop of 1.5 mg/L for the DO to be a minimum concentration of 8
mg/L. The average annual temperature was used in this calculation as if the maximum annual
temperature was used, this results in the solubility of oxygen being less than the CWQG for marine
aquatic life. For an ocean discharge, the maximum DO deficit should occur at the point source.
Assuming a deoxygenation rate of 0.23/day based on a depth of approximately 4.3 m at the
proposed discharge location (with a 100 m outfall extension), and assuming a reaeration coefficient
of 0.21/day based on a depth of approximately 4.3 m and an average tidal velocity of 0.062 m/s, the
maximum concentration of CBOD that would result in a drop in DO of 1.5 mg/L can be calculated.
The tidal dispersion coefficient has been assumed to be 150 m2/s. The concentration of CBOD
potentially affecting DO was calculated to be 11.75 mg/L. Therefore, the WSER criteria of 25 mg/L
CBOD at discharge should not cause the dissolved oxygen (DO) concentration to vary outside of the
normal range provided initial dilution is at least 2.2:1. The background level of CBOD was less than
the detection limit of 5 mg/L.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 21
Total Ammonia and Un‐ionized Ammonia
The CWQG for the protection of aquatic life for total ammonia in freshwater is presented as a table
based on pH and temperature. There is no CWQG for ammonia in marine water. Total ammonia is
comprised of un‐ionized ammonia (NH3) and ionized ammonia (NH4+, ammonium). Un‐ionized
ammonia is more toxic than ionized ammonia and the toxicity of total ammonia is related to the
concentration of un‐ionized ammonia present. The amount of un‐ionized ammonia is variable
depending on pH and temperature. The US EPA saltwater guideline for total ammonia is 2.7 mg/L
based on a temperature of 17.7 °C, a pH of 7.7 and a salinity of 30 g/kg. The US EPA guideline of 2.7
mg/L will be used as the EQO for total ammonia. As ammonia is a component of total nitrogen (TN),
the actual effluent concentration may be limited by the TN EDO rather than the total ammonia EDO.
However, as the TN EQO is based on concern of eutrophication and not a continuous acceptable
concentration for the protection of aquatic life, both EDOs will be presented separately in the ERA.
The WSER requires that un‐ionized ammonia concentrations be less than 1.25 mg/L at the discharge
point. For the purposes of this study, the EQO for un‐ionized ammonia was chosen based on the
WSER (1.25 mg/L at discharge).
Total Suspended Solids (TSS)
The WSER specifies a limit of 25 mg/L for TSS at the end of the pipe. The CWQG for the protection of
aquatic life in marine water for total suspended solids (TSS) is as follows:
During periods of clear flow, a maximum increase of 25 mg/L from background levels for any
short‐term exposure (e.g., 24‐h period). Maximum average increase of 5 mg/L from
background levels for longer term exposures (e.g., inputs lasting between 24 h and 30 d);
and
During periods of high flow, a maximum increase of 25 mg/L from background levels at any
time when background levels are between 25 and 250 mg/L. Should not increase more than
10% of background levels when background is ≥ 250 mg/L.
The background concentration of TSS was an average of 32 mg/L. A maximum average increase of 5
mg/L from background levels would result in an EQO of 37 mg/L. As this is greater than the WSER
criteria, the WSER criteria of 25 mg/L at discharge will apply as the EDO. The background TSS
measurement is higher than would typically be expected in a marine environment, which may be
due to the near shore location of the samples. However, in a worst‐case scenario where the
background TSS concentration was 0 mg/L, application of the WSER criteria at the end of pipe would
always be the more stringent criteria provided there is greater than five times dilution.
Total Phosphorus and TKN/TN
There are no CWQGs for the protection of aquatic life for phosphorus, Total Kjeldahl Nitrogen (TKN)
or total nitrogen (TN). However, in both freshwater and marine environments, adverse secondary
effects like eutrophication and oxygen depletion can occur. Guidance frameworks have been
established for freshwater systems and for marine systems to provide an approach for developing
site‐specific water quality guidelines. These approaches are based on determining a baseline
condition and evaluating various effects according to indicator variables. The approach is generally
Harbour Engineering Joint Venture Glace Bay WWTP ERA 22
very time and resource intensive, but can be completed on a more limited scale to establish interim
guidelines.
The Canadian Guidance Framework for the Management of Nutrients in Nearshore Marine Systems
Scientific Supporting Document (CCME, 2007) provides a framework as well as case studies for
establishing nutrient criteria for nearshore marine systems. This document provides a Trophic Index
for Marine Systems (TRIX), below in Table 3.6.
Table 3.6 ‐ Criteria for evaluating trophic status of marine systems (CCME, 2007)
Trophic Status TN
(mg/m3)
TP
(mg/m3) Chlorophyll a (μg/L) Secchi Depth
(m)
Oligotrophic <260 <10 <1 >6
Mesotrophic ≥260‐350 ≥10‐30 ≥1‐3 3‐≤6
Eutrophic ≥350‐400 ≥30‐40 ≥3‐5 1.5‐≤3
Hypereutrophic >400 >40 >5 <1.5
The background concentrations of total nitrogen (TN) and total phosphorus (TP) were measured as
0.233 mg/L and 0.035 mg/L, respectively, which corresponds to a eutrophic status based on the
phosphorus concentration. The uppermost limit for this trophic status is a TN concentration of 0.4
mg/L and a TP concentration of 0.04 mg/L.
This document provides another index (NOAA) to determine the degree of eutrophication of the
marine system, below in Table 3.7.
Table 3.7 ‐ Trophic status classification based on nutrient and chlorophyll (CCME, 2007)
Degree of
Eutrophication
Total Dissolved N
(mg/L)
Total Dissolved P
(mg/L)
Chl a
(μg/L)
Low 0 ‐ ≤0.1 0 ‐ ≤0.01 0 ‐ ≤5
Medium >0.1 ‐ ≤1 >0.01 ‐ ≤0.1 >5 ‐ ≤20
High >1 >0.1 >20 ‐ ≤60
Hypereutrophic ‐ ‐ >60
However, the concentrations in Table 3.7 are based on dissolved nitrogen and phosphorus and the
background concentrations are for total nitrogen and total phosphorus (0.233 mg/L and 0.035 mg/L,
respectively). For nitrogen, with a background concentration of 0.233 mg/L for TN, an assumption
that the dissolved nitrogen background concentration is anywhere between 43 and 100% of the TN
background concentration would result in classification as “medium” based on Table 3.7. For
phosphorus, with a background concentration of 0.035 mg/L, an assumption that the dissolved
background concentration is anywhere between 29 and 100% of the total background concentration
would result in classification as “medium” based on Table 3.7.
To maintain the same degree of eutrophication, the total dissolved nitrogen and total dissolved
phosphorus in the receiving water should not exceed the upper limit of the “medium” classification
which is 1 mg/L for Total Dissolved Nitrogen and 0.1 mg/L for Total Dissolved Phosphorus. In order
to determine the upper limit of the “medium” eutrophication range based on total phosphorus and
Harbour Engineering Joint Venture Glace Bay WWTP ERA 23
TN concentrations, an assumption must be made as to the percentage of the nitrogen and
phosphorus that exists in the dissolved phase, both in the receiving water and in the effluent. As a
measure of conservatism, an assumption was made that 100% of the total nitrogen and phosphorus
exist in a dissolved phase. This allows for the upper limits of the “medium” classification to be used
directly as the EQO which results in an EQO of 1 mg/L for TN and 0.1 mg/L for total phosphorus.
The Canadian Guidance Framework for the Management of Nutrients in Nearshore Marine Systems
Scientific Supporting Document (CCME, 2007) presents both of the above criteria for assessing
trophic status and does not provide a recommendation for use of one rather than the other.
However, the framework presents a case study to establish nutrient criteria for the Atlantic
Shoreline of Nova Scotia, and the NOAA index is used. Therefore, that index will be used for the
purpose of this study.
pH
The CWQG for the protection for aquatic life for marine waters is 7.0 to 8.7. This pH range will be
applied as the EQO.
Fluoride
The CCME CWQG for the protection of aquatic life for fluoride is 0.12 mg/L for freshwater. There is
no recommended marine guideline from either CCME or US EPA. The background concentration for
fluoride is 0.67 mg/L. There is a maximum acceptable concentration of 1.5 mg/L specified by the
British Columbia Ministry of Environment (BCMOE). However, as this is a maximum acceptable
concentration and not a long term or continuous concentration, it will not be used. Therefore, the
background concentration of 0.67 mg/L will be applied as the site‐specific EQO.
Nitrate
The CCME CWQG for the protection of aquatic life for nitrate is 200 mg/L for marine waters, 45
mg/L as N. Nitrate is substantially less toxic than nitrite and ammonia, but can still yield toxic effects.
Background pH and temperature can influence the conversion of nitrate to nitrite and other forms
of nitrogen. Typically, the CCME marine water quality guideline of 45 mg/L would be used as the
EQO, however, the total nitrogen EQO determined to limit eutrophication will govern (at 1.0 mg/L).
As the TN EQO is based on a concern of eutrophication, both limits will be presented separately in
the ERA.
Nitrite
The CCME CWQG for the protection of aquatic life for nitrite is 0.06 mg/L as nitrogen for freshwater,
and there is no recommended marine guideline. Nitrite has been found to be more toxic to some
groups of fish, particularly salmonids. The freshwater guideline of 0.06 mg/L will be applied as the
EQO for this assessment. However, this generic objective may be overly conservative when applied
to the marine receiving environment.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 24
Cyanide
The CCME CWQG for the protection of aquatic life for cyanide is 0.005 mg/L (free CN) for
freshwater. There is no CWQG for marine waters. The US EPA water quality criterion for saltwater is
0.001 mg/L (free CN). Both the CCME and US EPA criteria are for free cyanide, whereas the Standard
Method specifies to sample for total cyanide. Cyanide was not detected in the background samples.
The US EPA criteria of 0.001 mg/L will be applied as the EQO for cyanide. However, comparing
sample results from the wastewater characterization samples to this value will be overly
conservative as the analytical results are for total cyanide rather than free cyanide.
Total Residual Chlorine
The WSER requires that TRC concentrations be less than 0.02 mg/L. For the purposes of this study,
an EQO/EDO of 0.02 mg/L for TRC was chosen based on this regulation.
3.3.2 Metals
Of the 25 metals measured during the wastewater characterization study, 15 were detected in the
wastewater of at least one sample. The EQOs for the detected metals are described below.
Aluminum
The CCME CWQG for the protection of aquatic life for aluminum in freshwater is dependent on pH;
the guideline is 5 µg/L if the pH is less than 6.5 and 100 µg/L if the pH is 6.5 or greater. There are no
CWQG or USEPA guidelines for marine waters. The average background concentration of aluminum
was 274 µg/L. The background concentration of 274 µg/L will be used as the site‐specific EQO.
Barium
There are no CCME CWQGs for the protection of aquatic life for barium in freshwater or marine
waters. There is also no water quality guideline from the US EPA or British Columbia Ministry of
Environment (BCMOE) for salt water. As no relevant published water quality guidelines were found
for barium, an EQO will not be developed.
Cadmium
The CCME CWQG for the protection of aquatic life for cadmium in marine waters is 0.12 µg/L.
Cadmium was not detected in the background sample (at a detection limit of 0.05 µg/L). Therefore
the EQO will remain the same as the CCME marine CWQG of 0.12 µg/L.
Cobalt
There are no CCME CWQGs for the protection of aquatic life for cobalt in freshwater or marine
waters. There is also no US EPA water quality guideline. There are no water quality guidelines from
the BCMOE for marine waters. As no relevant published water quality guidelines were found for
cobalt, an EQO will not be developed.
Copper
The CCME CWQG for the protection of aquatic life for copper in freshwater is given as an equation
based on water hardness and there is no guideline specified for marine waters. The freshwater
guideline was calculated to be 4 µg/L based on the average background water hardness of 5050
Harbour Engineering Joint Venture Glace Bay WWTP ERA 25
mg/L. The US EPA salt water quality criterion is 3.7 µg/L. The average background concentration of
copper was 0.47 µg/L. Therefore the USEPA salt water quality criterion of 3.7 µg/L will be used as
the EQO.
Iron
The CCME CWQG for the protection of aquatic life for iron in freshwater is 300 µg/L. There is no
guideline specified for marine waters. There is no US EPA or BC MOE salt water quality criterion for
iron. The average background concentration for iron was 393 µg/L. The EQO will be based on the
background concentration of 393 µg/L. However, this may be overly conservative for a marine
environment as the generic EQO is based on a freshwater guideline.
Lead
The CCME CWQG for the protection of aquatic life for lead in freshwater is given as an equation
based on water hardness and there is no guideline specified for marine waters. The freshwater
guideline was calculated to be 6 µg/L based on the average background water hardness of 5050
mg/L. The US EPA salt water quality criterion is 8.5 µg/L. The average background concentration of
lead was 0.225 µg/L. Therefore the USEPA salt water quality criterion of 8.5 µg/L will be used as the
EQO.
Manganese
There are no CCME CWQGs for the protection of aquatic life for manganese in freshwater or marine
waters. There is also no criterion provided by US EPA. However, there is a working water quality
guideline for marine aquatic life for manganese provided by the BCMOE of 100 µg/L. The
background concentration of manganese was 15 µg/L. The guideline of 100 µg/L will be used as the
EQO for manganese.
Molybdenum
The CCME CWQG for the protection of aquatic life for molybdenum is 73 µg/L for freshwater and
there is no guideline for marine waters. There is no US EPA water quality guideline for salt water.
There is no BCMOE criteria for marine water. The average concentration of molybdenum in the
background samples was 9.1 µg/L. The CCME CWQG for freshwater of 73 µg/L will be applied as the
EQO. However, this may be overly conservative for a marine environment as the generic EQO is
based on a freshwater guideline.
Nickel
The CCME CWQG for the protection of aquatic life for nickel is 150 µg/L for freshwater based on an
average background hardness of 5050 mg/L. There is no CWQG for marine waters. The US EPA salt
water quality criterion is 8.3 µg/L. Nickel was not detected in the background samples (at a
detection limit of 0.2 µg/L). Therefore the US EPA salt water quality criterion of 8.3 µg/L will be used
as the EQO.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 26
Strontium
There is no CCME CWQG for strontium for the protection of aquatic life. There is no water quality
guideline provided by US EPA or BCMOE. As no relevant published water quality guidelines were
found for strontium, an EQO will not be developed.
Titanium
There is no CCME CWQG for titanium for the protection of aquatic life. There is no water quality
guideline provided by US EPA or BCMOE. As no relevant published water quality guidelines were
found for titanium, an EQO will not be developed.
Uranium
The CCME CWQG for the protection of aquatic life for uranium is 15 µg/L for freshwater and there is
no guideline for marine waters. There is no US EPA water quality guideline for salt water. There is no
BCMOE criteria for marine water. The background concentration for uranium was 2.53 µg/L. The
CCME WQG for freshwater of 15 µg/L will be applied as the EQO. However, this may be overly
conservative for a marine environment as the generic EQO is based on a freshwater guideline.
Zinc
The CCME CWQG for the protection of aquatic life for zinc is 30 µg/L for freshwater and there is no
guideline for marine waters. The US EPA water quality guideline for salt water is 86 µg/L. The
average background concentration of zinc was 0.95 µg/L. The US EPA criterion of 86 µg/L will be
applied as the EQO for zinc.
Mercury
The CCME WQG for the protection of aquatic life for mercury is 0.026 µg/L for freshwater and 0.016
µg/L for marine waters. The US EPA water quality guideline for salt water is 1.1 µg/L. The EQO will
be the CCME marine guideline of 0.016 µg/L.
3.3.3 E. coli
Pathogens are not included in the CCME CWQGs for the protection of aquatic life. The Health
Canada Guidelines for Canadian Recreational Water Quality specify a maximum E. coli concentration
of 200 E. coli/100 mL for freshwater for primary contact recreation and 1000 E. coli/100 mL for
secondary contact recreation. The Health Canada guideline for Canadian Recreational Water Quality
for primary and secondary contact recreation in marine water is based on enterococci rather than E.
coli. However, historically Nova Scotia Environment has set discharge limits for E. coli rather than
enterococci for marine discharges. The background concentration of E. coli was 69 E. coli/100 mL.
An EQO of 200 E. coli/ 100 mL will apply for primary contact recreation at Table Head and Big Glace
Bay beaches. An EQO of 1000 E. coli/ 100mL based on the Canadian Recreational Water Quality
guideline for secondary contact for freshwater will apply elsewhere in the receiving water.
There is currently a molluscan shellfish closure zone in the immediate vicinity of the outfall (SSN‐
2006‐007 on Figure 3.1). However, consideration will have to be given to E. coli concentrations
outside of the closure zone. It is also possible that the closure zone will be changed once the
proposed WWTPs in CBRM are operational. The Canadian Shellfish Sanitation Program (CSSP)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 27
requires that the median of the samples collected in an area in one survey not exceed 14 E. coli/100
mL, and no more than 10% of the samples can exceed 43 E. coli/100 mL. However, the average
measured background concentration for E. coli was 69 E. coli/100 mL. These background samples
were collected from shore and may not be representative of the actual ambient concentration of E.
coli in the area.
3.3.3.1 ORGANOCHLORINE PESTICIDES
Of the list of organochlorine pesticides included in the Standard Method for substances of potential
concern for a medium facility, there were no detections. There were detections for one
organochlorine pesticide (endrin aldehyde). As this parameter is not included in the standard
method, an EDO was not developed. This parameter could be considered in the future development
of the compliance monitoring program.
3.3.3.2 POLYCHLORINATED BIPHENYLS (PCBS)
Total polychlorinated biphenyls (PCBs) were not detected in the wastewater and therefore an EQO
was not established.
3.3.3.3 POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)
Polycyclic aromatic hydrocarbons (PAHs) were measured as part of initial wastewater
characterization. Of the list of PAHs included in the Standard Method for substances of potential
concern for a medium facility, 14 substances were detected during the initial wastewater
characterization study: acenaphthene, anthracene, benzo(a)anthracene, benzo(a)pyrene,
Benzo(b)fluoranthene, benzo(g,h,i)perylene, benzo(k)fluoranthene, chrysene,
dibenz(a,h)anthracene, fluoranthene, fluorene, indeno(1,2,3‐cd)pyrene, pyrene, and phenanthrene.
There are CCME CWQGs for the protection of aquatic life for freshwater for 8 of the 14 substances
that were detected. There were no CCME marine water quality guidelines. There are BC MOE
approved marine water quality guidelines for 3 of the 14 substances. The guidelines are as follows:
Acenaphthene – 5.8 µg/L (freshwater), 6 µg/L (BCMOE marine);
Anthracene – 0.012 µg/L (freshwater);
Benzo(a)anthracene – 0.018 µg/L (freshwater);
Benzo(a)pyrene – 0.015 µg/L (freshwater);
Chrysene – 0.1 µg/L (BCMOE marine);
Fluoranthene – 0.04 µg/L (freshwater);
Fluorene – 3 µg/L (freshwater), 12 µg/L (BCMOE marine);
Phenanthrene – 0.4 µg/L (freshwater); and
Pyrene – 0.025 µg/L (freshwater).
None of the nine (9) substances listed above were detected in the background sample. Therefore,
the above guidelines will be applied as the EQOs. However, the freshwater generic objectives may
be overly conservative when applied to the marine receiving environment.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 28
3.3.3.4 VOLATILE ORGANIC COMPOUNDS (VOCS)
Of the list of Volatile organic compounds (VOCs) included in the Standard Method for substances of
potential concern for a medium facility, 3 were detected in the wastewater. There are CCME CWQGs
for the protection of aquatic life for freshwater for 2 of the 3 substances that were detected. There
is a marine guideline for one of the substances that was detected. There are no applicable guidelines
for bromodichloromethane. The guidelines are as follows:
Chloroform – 1.8 µg/L (freshwater); and
Toluene – 2 µg/L (freshwater), 215 µg/L (marine).
The above bolded guidelines will be applied as the EQOs. However, the freshwater generic
objectives may be overly conservative when applied to the marine receiving environment.
3.3.3.5 PHENOLIC COMPOUNDS
The CCME CWQG for the protection of aquatic life for phenols in freshwater is 4 µg/L. There is no
guideline specified for marine waters. There is no US EPA or BCMOE salt water quality criterion for
phenols. The background concentration was 0.0305 mg/L. The EQO will be based on the background
concentration of 0.0305 mg/L.
3.3.3.6 SURFACTANTS
Surfactants were not analyzed in the wastewater samples. This analysis was not available locally,
and there are no CWQG available from either CCME or US EPA for non‐ionic or anionic surfactants to
compare the results to if the analysis was completed.
3.3.4 Summary
Table 3.8 below gives a summary of the generic and site‐specific EQOs determined for parameters of
concern. The source of the EQO has been included in the table as follows:
WSER – wastewater systems effluent regulations
Background – Site‐specific EQO based on background concentration in receiving water
CWQG Marine – CCME Canadian Water Quality Guidelines for the Protection of Aquatic Life
Marine
USEPA Saltwater – United States Environmental Protection Agency National Recommended
Water Quality Criteria – Aquatic Life Criteria – Saltwater Criterion Continuous Concentration
CGF, Marine – Canadian Guidance Framework for the Management of Nutrients in Nearshore
Marine Systems Scientific Supporting Document
BCMOE AWQG – BCMOE Approved Water Quality Guideline
BCMOE WWQG – BCMOE Working Water Quality Guideline
CWQG Freshwater – CCME Canadian Water Quality Guidelines for the Protection of Aquatic Life
Freshwater
HC Primary Contact – Health Canada Guidelines for Canadian Recreational Water Quality –
Primary Contact Recreation
HC Secondary Contact – Health Canada Guidelines for Canadian Recreational Water Quality –
Secondary Contact Recreation
CSSP – Canadian Shellfish Sanitation Program
Harbour Engineering Joint Venture Glace Bay WWTP ERA 29
Table 3.8 – EQO Summary
Parameter Generic EQO Background Selected
EQO Source
CBOD5 (mg/L) 25 <5.0 25 WSER
Total NH3‐N (mg/L)(1) 2.7 <0.05 2.7 USEPA Saltwater
TSS (mg/L) 25 32 25 WSER
TP (mg/L) 0.1 0.035 0.1 CGF, Marine
TN (mg/L)(1) 1 0.233 1 CGF, Marine
pH 7 ‐ 8.7 7.71 7 ‐ 8.7 CWQG Marine
Un‐ionized NH3 (mg/L) 1.25 <0.0007 1.25 WSER
E. coli ‐ Primary Contact
(MPN/100mL) 200 69 200 HC Primary Contact
E. coli ‐ Secondary Contact
(MPN/100mL) 1000 69 1000 HC Secondary
Contact
E. coli ‐ Molluscan Shellfish
(MPN/100mL) 14 69 14 CSSP
Fluoride (mg/L) 0.67 0.67 0.67 Background
Nitrate (mg/L)(1) 45 0.038 45 CWQG Marine
Nitrite (mg/L) 0.06 <0.001 0.06 CWQG Freshwater
Free Cyanide (mg/L) 0.001 <0.0010 0.001 USEPA Saltwater
Aluminum (mg/L) 0.1 0.274 0.274 Background
Cadmium (mg/L) 0.00012 <0.00005 0.00012 CWQG Marine
Copper (mg/L) 0.0037 0.00047 0.0037 USEPA Saltwater
Iron (mg/L) 0.3 0.393 0.393 Background
Lead (mg/L) 0.0085 0.000225 0.0085 USEPA Saltwater
Manganese (mg/L) 0.1 0.015 0.1 BCMOE WWQG
Molybdenum (mg/L) 0.073 0.0091 0.073 CWQG Freshwater
Nickel (mg/L) 0.0083 <0.0002 0.0083 USEPA Saltwater
Uranium (mg/L) 0.015 0.00253 0.015 CWQG Freshwater
Zinc (mg/L) 0.086 0.00095 0.086 USEPA Saltwater
Mercury (mg/L) 0.000016 0.000013 0.000016 CWQG Marine
Acenaphthene (µg/L) 6 <0.010 6 BCMOE AWQG
Anthracene (µg/L) 0.012 <0.010 0.012 CWQG Freshwater
Benzo(a)anthracene (µg/L) 0.018 <0.010 0.018 CWQG Freshwater
Benzo(a)pyrene (µg/L) 0.015 <0.010 0.015 CWQG Freshwater
Chrysene (µg/L) 0.1 <0.010 0.1 BCMOE AWQG
Fluoranthene (µg/L) 0.04 <0.010 0.04 CWQG Freshwater
Fluorene (µg/L) 12 <0.010 12 BCMOE AWQG
Phenanthrene (µg/L) 0.4 <0.010 0.4 CWQG Freshwater
Pyrene (µg/L) 0.025 <0.010 0.025 CWQG Freshwater
Chloroform (µg/L) 1.8 <1.0 1.8 CWQG Freshwater
Toluene (µg/L) 215 <1.0 215 CWQG Marine
Phenols (mg/L) 0.004 0.0305 0.0305 Background
Notes: Bold indicates EQO is a WSER requirement.
(1) Although the EQOs for ammonia and nitrate have been calculated to be 2.7 mg/L and 45 mg/L, respectively, the EQO of 1 mg/L for total nitrogen
would govern. However, as the EQO for TN is based on eutrophication, EDOs will be developed for all parameters separately.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 30
CHAPTER 4 MIXING ZONE ANALYSIS
4.1 Methodology
4.1.1 Definition of Mixing Zone
A mixing zone is the portion of the receiving water where effluent dilution occurs. In general, the
receiving water as a whole will not be exposed to the immediate effluent concentration at the end‐
of‐pipe but to the effluent mixed and diluted with the receiving water. Effluent does not
instantaneously mix with the receiving water at the point of discharge. Depending on conditions
like ambient currents, wind speeds, tidal stage and wave action, mixing can take place over a large
area – up to the point where there is no measureable difference between the receiving water and
the effluent mixed with receiving water.
The mixing process can be characterized into two distinct phases: near‐field and far‐field. Near‐
field mixing occurs at the outfall and is influenced by the configuration of the outfall (e.g. pipe size,
diffusers, etc.). Far‐field mixing is influenced by receiving water characteristics like turbulence, wave
action, and stratification of the water column.
Within the mixing zone, EQOs may be exceeded but acutely toxic conditions are not permitted
unless it is determined that un‐ionized ammonia is the cause of toxicity. If the un‐ionized ammonia
concentration is the cause of toxicity, there may be an exception (under the WSER) if the
concentration of un‐ionized ammonia is less than or equal to 0.016 mg/L, expressed as N, at any
point that is 100 m from the discharge point. Outside of the mixing zone, EQOs must be achieved.
The effluent is also required to be non‐chronically toxic outside of the mixing zone. The allocation of
a mixing zone varies from one substance to another – degradable substances are allowed to mix in a
portion of the receiving water whereas toxic, persistent, and bio‐accumulative substances (such as
chlorinated dioxins and furans, PCBs, mercury and toxaphene) are not allowed a mixing zone.
A number of general criteria for allocating a mixing zone are recommended in the Strategy, including the
following:
The dimensions of a mixing zone should be restricted to avoid adverse effects on the designated
uses of the receiving water system (i.e., the mixing zone should be as small as possible);
Conditions outside of the mixing zone should be sufficient to support all of the designated uses
of the receiving water system;
A zone of passage for mobile aquatic organisms must be maintained;
Placement of mixing zones must not block migration into tributaries;
Harbour Engineering Joint Venture Glace Bay WWTP ERA 31
Changes to the nutrient status of the water body as a result of an effluent discharge should be
avoided; eutrophication or toxic blooms of algae are unacceptable impacts;
Mixing zones for adjacent wastewater discharges should not overlap; and
Adverse effects on the aesthetic qualities of the receiving water system (e.g. odour, colour,
scum, oil, floating debris) should be avoided (CCME, 2008).
The limits of the mixing zone may be defined for the following three categories of aquatic
environments based on their physical characteristics:
streams and rivers;
lakes, reservoirs and enclosed bays; and
estuarine and marine waters.
Where several limits are in place, the first one to be reached sets the maximum extent of the mixing
zone allowed for the dilution assessment. Nutrients and fecal coliforms are not allocated any
maximum dilution. For fecal coliforms, the location of the water use must be considered and
protected by the limits of the mixing zone.
Based on these general guidelines, mixing zone extents must be defined on a case‐by‐case basis that
account for local conditions. It may also be based on arbitrary mixing zone limits for open water
discharges, e.g. a 100 m (Environment Canada, 2006) or 250 m (NB DOE, 2012) radius from the
outfall and/or a dilution limit. A Draft for Discussion document “Mixing Zone Assessment and
Report Templates” dated July 7, 2016, prepared by a committee of representatives of the
environment departments in Atlantic Canada, provides guidance regarding mixing zones for ERAs in
the Atlantic Provinces. This document recommends that for ocean and estuary receiving waters a
maximum dilution limit of 1:1000 be applied for far‐field mixing.
Finally, the assessment shall be based on ‘critical conditions’. For example, in the case of a river
discharge (not applicable here), ‘critical conditions’ can be defined as the seven‐day average low
river flow for a given return period. For ocean discharges, we propose to use a maximum one‐day
average effluent concentration at the edge of the mixing zone. The Standard Method provides the
following guidance on EDO development:
“…reasonable and realistic but yet protective scenarios should be used. The objective is to simulate
the critical conditions of the receiving water, where critical conditions are where the risk that the
effluent will have an effect on the receiving environment is the highest – it does not mean using the
highest effluent flow, the lowest river flow and the highest background concentration
simultaneously.”
As a plausible worst‐case condition is used for the receiving water, the WWTP effluent will be
modelled based on an annual average flow, rather than a maximum daily or hourly flow, as applying
a critical high flow condition for the effluent simultaneously with a worst case condition in the
receiving water would result in overly conservative EDOs as this scenario doesn’t provide a
reasonable or realistic representation of actual conditions.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 32
4.1.2 Site Summary
The WWTP was first assumed to discharge through an outfall pipe perpendicular to the shoreline in
shallow water, extended to a depth estimated at ‐1.0 m below low tide (base condition). The
modelled dilution for the base condition was significantly limited by the presence of the breakwater.
Subsequent model runs were completed with a variety of outfall extensions to obtain sufficient
dilution so that the calculated EDOs would be reasonably attainable. The selected scenario assumed
that the effluent discharged through an outfall pipe perpendicular to the shoreline in shallow water,
extended to a depth estimated at ‐3.8 m below low tide based on a 100 m outfall extension. The low
tide and depth contours were estimated based on navigation charts. The total average effluent
discharge is modeled as a continuous point source of 14,200 m3/day.
The major coastal hydrodynamic features of the area are as follows:
Along‐shore currents along the open coastline are in phase with the tide, i.e. the current
speed peaks at high and low tide; and
At the outfall site, breaking waves and associated longshore currents will contribute to
effluent dispersion during storms. For this assessment, we have assumed calm summer
conditions (i.e. no waves), when effluent dilution would be at a minimum.
4.1.3 Far‐Field Modeling Approach and Inputs
The local mixing zone is limited by the water depth at the extended outfall of approximately ‐3.8 m
Chart Datum and by the presence of the shoreline. Since the outfall is in shallow water, the buoyant
plume will always reach the surface upon release from the outfall (Fisher et al., 1979). Far‐field
mixing will then be determined by ambient currents, which is best simulated with a hydrodynamic
and effluent dispersion model.
We implemented a full hydrodynamic model of the receiving coastal waters using the Danish
Hydraulic Institute’s MIKE21 model. MIKE21 is ideally suited to the study of outfall discharges in
shallow coastal areas where complex tidal and wind‐driven currents drive the dispersion process.
The model was developed using navigation charts, tidal elevations and wind observations for the
area. A similar model had been used by CBCL for CBRM in the past:
In 2005 for the assessment of the past wastewater contamination problem at Dominion
Beach, which led to the design of the WWTP at Dominion (CBCL, 2005); and
In 2014 for ERAs at the Dominion and Battery Point WWTPs.
The hydrodynamic model was calibrated to the following bottom current meter data:
1992 current meters (4 locations) located in 10 m‐depth for the study by ASA (ASA, 1994)
on local oceanography and effluent dispersion; and
2006 current meters (2 locations) off the Donkin peninsula for the CBCL study of mine
effluent dispersion.
Calibration consisted of adjusting the following parameters:
Bottom friction; and
Model spatial resolution in the area of the current meters.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 33
Numerical model domain with locations of current meter observations and modeled outfall location
are shown in Figure 4.1. Inputs and calibrated outputs are shown in Figure 4.2. The modelled
current magnitudes at New Waterford, Glace Bay and Donkin are in relatively good agreement with
observations, which is satisfactory to assess the overall dilution patterns of effluent from the outfall.
The effect of waves was not included in the model, and therefore the modeled effluent
concentration near the outfall is expected to be conservatively high.
Figure 4.1 Numerical Model Domain with Locations of Current Meter Observations (squares)
and Modeled Outfall Location (black circle)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 34
Figure 4.2 Time‐series of Hydrodynamic Model Inputs and Calibration Outputs
Harbour Engineering Joint Venture Glace Bay WWTP ERA 35
4.1.4 Modeled Effluent Dilution
Snapshots of typical modeled effluent dispersion patterns are shown on Figures 4.3 and 4.4 for the
base condition and 100 m outfall extension. Statistics on effluent concentrations were performed
over the 1‐month model run, and over a running 7‐day and 1‐day averaging period. Composite
images of maximum and average effluent concentrations are shown on Figures 4.5 and 4.6.
Effluent concentration peaks at any given location are short‐lived because the plume is changing
direction every few hours depending on tides and winds. Therefore, a representative dilution
criteria at the mixing zone limit is best calculated using an average value. We propose to use the
one‐day average effluent concentration criteria over the one‐month modeling simulation that
includes a representative combination of site‐specific tides and winds.
The dilution of the effluent plume is dependent on the outfall extension length due to its proximity
to the breakwaters located at Glace Bay. Generally the diluted effluent plume was found to reach
the shoreline north‐west of the outfall as well as the shoreline to the east of the harbour. Large
eddies tend to form due to the circulation patterns within the region. It was noted that the effluent
would travel into the harbour. The 100 m distance from the outfall to the shoreline is within the
brackets of mixing zone radiuses defined by various guidelines. We propose that this distance be
used as mixing zone limit.
For the first model scenario where the outfall was extended until the top of the outfall was 1 m
below low water level, the maximum 1‐day average effluent concentration 100 m away from the
outfall over the simulation period is 21.94%, corresponding to a dilution factor of 4.56:1.
Table 4.1 Modelled Dilution Values 100 and 200 m away from the Outfall (Existing Location)
Distance
away from
the outfall
Hourly maximum
effluent
concentration
Maximum 1‐day
average effluent
concentration
Maximum 7‐day
average effluent
concentration
1‐Month average
effluent
concentration
100 m 33.35 % (3.0:1
Dilution)
21.94 % (4.56:1
Dilution)
15.51 % (6.45:1
Dilution)
7.36 % (13.59:1
Dilution)
200 m 30.09 % (3.32:1
Dilution)
13.22 % (7.56:1
Dilution)
9.09% (11.00:1
Dilution)
9.08 % (11.01:1
Dilution)
Extensions to the current outfall were examined to ensure that the effluent concentration was
suitably diluted at the edge of a 100 m mixing zone, and the results are presented in Table 4.2.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 36
Table 4.2 Modelled Dilution Values 100 m away from the Outfall for Outfall Extensions of 50
to 500 m
Outfall
Extension
Distance
Hourly maximum
effluent
concentration
Maximum 1‐day
average effluent
concentration
Maximum 7‐day
average effluent
concentration
1‐Month average
effluent
concentration
50 m 18.72 % (5.34:1
Dilution)
10.33 % (9.68:1
Dilution)
6.34 % (15.77:1
Dilution)
4.88 % (20.49:1
Dilution)
100 m 15.97 % (6.26:1
Dilution)
4.06 % (24.63:1
Dilution)
3.57 % (28.01:1
Dilution)
2.55 % (39.22:1
Dilution)
150 m 22.24 % (4.50:1
Dilution)
7.4 % (13.51:1
Dilution)
3.77 % (26.53:1
Dilution)
2.77 % (36.10:1
Dilution)
200 m 26.46 % (3.78:1
Dilution)
3.83 % (26.11:1
Dilution)
2.72 % (36.76:1
Dilution)
2.60 % (38.46:1
Dilution)
300 m 31.39 % (3.19:1
Dilution)
5.07 % (19.72:1
Dilution)
2.48 % (40.32:1
Dilution)
2.00 % (50:1 Dilution)
400 m 24.40 % (4.10:1
Dilution)
2.16 % (46.30:1
Dilution)
1.08 % (92.59:1
Dilution)
0.96 % (104.17:1
Dilution)
500 m 12.51 % (7.99:1
Dilution)
1.5 % (66.67:1
Dilution)
0.83 % (120.48:1
Dilution)
0.61 % (163.93:1
Dilution)
Based on preliminary analysis, an outfall extension of 100 m has been assumed in order to obtain a
level of dilution that results in EDOs that are considered to be reasonably attainable. However, as
phosphorus is the parameter that appears to be driving the need for an outfall extension, additional
evaluation should be conducted during detailed design in conjunction with discussions with NSE to
determine what is required.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 37
Figure 4.3 Snapshots of Typical Modeled Effluent Dispersion Patterns (base condition)
Harbour Engineering Joint Venture Glace Bay WWTP ERA 38
Figure 4.4 Snapshots of Typical Modeled Effluent Dispersion Patterns for 100 m Outfall
Extension
Harbour Engineering Joint Venture Glace Bay WWTP ERA 39
Figure 4.5 Composite Images of Modeled Maximum 1‐day Average (top) and Maximum 7‐
Day Average Effluent Concentrations (middle) with Concentration Time‐Series (bottom) for 100 m
outfall extension Note: 100‐m radius (black) and 200‐m radius (grey) circle shown around outfall
Harbour Engineering Joint Venture Glace Bay WWTP ERA 40
Figure 4.6 Composite Images of Modeled Maximum 1‐Day Average Effluent Concentrations
at Tablehead Beach (top) and Big Glace Bay Beach (bottom), primary contact recreation areas
Note: 100‐m radius (black) and 200‐m radius (grey) circle shown around outfall. Red circle denotes primary
contact recreation areas
Harbour Engineering Joint Venture Glace Bay WWTP ERA 41
CHAPTER 5 EFFLUENT DISCHARGE OBJECTIVES
5.1 The Need for EDOs
Effluent Discharge Objectives (EDOs) represent the effluent substance concentrations that will protect
the receiving environment and its designated water uses. They describe the effluent quality necessary
to allow the EQOs to be met at the edge of the mixing zone. The EQOs are established in Chapter 3; see
Table 3.8 for summary of results.
EDOs should be calculated where reasonable potential of exceeding the EQOs at the edge of the mixing
zone has been determined. Typically, substances with reasonable potential of exceeding the EQOs have
been selected according to the simplified approach: If a sample result measured in the effluent exceeds
the EQO, an EDO is determined. As only one sample event was collected from each outfall, rather than a
full year of effluent characterization, EDOs will be developed for all substances of potential concern that
were detected in at least one sample, and for which an EQO was identified.
5.2 Physical/ Chemical/ Pathogenic EDOs
For this assessment, EDOs were calculated using the dilution values obtained at the proposed
average design flow of 14,200 m3/day with a proposed 100 m outfall extension. This resulted in a
dilution of 24.63:1 at the edge of a 100 m mixing zone. The model shows a dilution of 2500:1 at Big
Glace Bay Beach and 169:1 at Table Head Beach (primary contact recreation areas) based on the
maximum 1‐day average concentration.
Parameters for which there is a WSER criteria were not allowed any dilution and therefore the EDO
equals the WSER Criteria. The Standard Method does not allocate any maximum dilution for
nutrients and fecal coliforms. For nutrients, it recommends a case‐by‐case analysis. For fecal
coliforms, the location of the water use must be protected by the limits of the mixing zone.
The dilution values were used to obtain an EDO by back‐calculating from the EQOs. When the
background concentration of a substance was less than the detection limit, the background
concentration was not included in the calculation of the EDO.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 42
5.3 Effluent Discharge Objectives
Substances of concern for which an EDO was developed are listed in Tables 5.1 below with the
associated EQO, maximum measured wastewater concentration, and the associated EDO. The
effluent is also required to be non‐acutely toxic at the end of pipe, and non‐chronically toxic at the
edge of the mixing zone.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 43
Table 5.1 – Effluent Discharge Objectives at Proposed Design Conditions
Parameter Maximum
Conc. (4) Background Selected
EQO Source Dilution
Factor EDO(1)
CBOD5 (mg/L)(1) 130 <5.0 25 WSER ‐ 25
Total NH3‐N (mg/L) 3.8 <0.05 2.7 USEPA Saltwater 24.63 66.5
TSS (mg/L)(1) 53 32 25 WSER ‐ 25
TP (mg/L) 2.2 0.035 0.1 CGF, Marine 24.63 1.6
TN (mg/L) 16 0.233 1 CGF, Marine 24.63 19.1
Un‐ionized NH3 (mg/L)(1) 0.0207 <0.0007 1.25 WSER ‐ 1.25
E. coli ‐ Primary Contact
(MPN/100mL)(2) 170000 69 200 HC Primary
Contact 169 22,208
E. coli ‐ Secondary Contact
(MPN/100mL) 170000 69 1000 HC Secondary
Contact 24.63 23,000
E. coli ‐ Molluscan Shellfish
(MPN/100mL) 170000 69 14 CSSP Note (3) See
Discussion
Fluoride (mg/L) 0.12 0.67 0.67 Background 24.63 0.67
Nitrate (mg/L) 1 0.038 45 CWQG Marine 24.63 1107.5
Nitrite (mg/L) 0.83 <0.001 0.06 CWQG Freshwater 24.63 1.48
Free Cyanide (mg/L) 0.013(5) <0.0010 0.001 USEPA Saltwater 24.63 0.025
Aluminum (mg/L) 0.66 0.274 0.274 Background 24.63 0.274
Cadmium (mg/L) 0.00036 <0.00005 0.00012 CWQG Marine 24.63 0.003
Copper (mg/L) 0.015 0.00047 0.0037 USEPA Saltwater 24.63 0.080
Iron (mg/L) 1 0.393 0.393 Background 24.63 0.393
Lead (mg/L) 0.0029 0.000225 0.0085 USEPA Saltwater 24.63 0.204
Manganese (mg/L) 0.75 0.015 0.1 BCMOE WWQG 24.63 2.11
Molybdenum (mg/L) 0.0065 0.0091 0.073 CWQG Freshwater 24.63 1.58
Nickel (mg/L) 0.011 <0.0002 0.0083 USEPA Saltwater 24.63 0.204
Uranium (mg/L) 0.00017 0.00253 0.015 CWQG Freshwater 24.63 0.310
Zinc (mg/L) 0.11 0.00095 0.086 USEPA Saltwater 24.63 2.10
Mercury (mg/L) 0.000013 0.000013 0.000016 CWQG Marine ‐ 0.000016
Acenaphthene (µg/L) 0.015 <0.010 6 BCMOE AWQG 24.63 147.8
Anthracene (µg/L) 0.037 <0.010 0.012 CWQG Freshwater 24.63 0.296
Benzo(a)anthracene (µg/L) 0.09 <0.010 0.018 CWQG Freshwater 24.63 0.44
Benzo(a)pyrene (µg/L) 0.064 <0.010 0.015 CWQG Freshwater 24.63 0.369
Chrysene (µg/L) 0.073 <0.010 0.1 BCMOE AWQG 24.63 2.463
Fluoranthene (µg/L) 0.21 <0.010 0.04 CWQG Freshwater 24.63 0.99
Fluorene (µg/L) 0.02 <0.010 12 BCMOE AWQG 24.63 295.56
Phenanthrene (µg/L) 0.12 <0.010 0.4 CWQG Freshwater 24.63 9.85
Pyrene (µg/L) 0.16 <0.010 0.025 CWQG Freshwater 24.63 0.62
Chloroform (µg/L) 5 <1.0 1.8 CWQG Freshwater 24.63 44
Toluene (µg/L) 1.3 <1.0 215 CWQG Marine 24.63 5295
Phenols (mg/L) 0.017 0.0305 0.0305 Background 24.63 0.03
Notes:
(1) For parameters where the EQO is based on the WSER, no dilution is permitted.
(2) Dilution at Table Head and Big Glace Bay Beaches of 169:1 and 2500:1, respectively.
(3) Existing closure zone boundary is outside the limits of the plume.
(4) Maximum concentration of existing wastewater samples.
(5) Maximum wastewater concentration based on total cyanide.
Yellow highlight indicates the maximum measured concentration exceeds the EQO; orange highlight indicates the
maximum measured concentration exceeds the EDO
Harbour Engineering Joint Venture Glace Bay WWTP ERA 44
Based on the EDOs calculated based in the current Average Daily Flow, sample results for the
following parameters exceeded the EDO in at least one wastewater characterization sample:
CBOD;
TSS;
Total Phosphorus;
E. coli;
Aluminum, and
Iron.
Some of these parameters will be reduced through treatment. In addition, the above list is based on
a single sample exceedance at any one of the outfall locations, which may not reflect the results
obtained when all of the individual outfalls are intercepted and combined. Further, some of the
EQOs were based on published water quality guidelines that may be overly stringent for a marine
receiving environment, due to a lack of a more appropriate guideline. Comments on each
parameter in the list above is provided below:
CBOD, TSS, and E. coli
These parameters will meet the EDOs at the discharge of the new WWTP through treatment.
Total Phosphorus
The total phosphorous EDO of 1.6 mg/L will likely not be consistently obtained with secondary
treatment. Options to ensure that the EDO is met would include additional treatment, or an outfall
extended into deeper water to obtain more dilution. Both of these options would come with a cost
that is not insignificant. The total phosphorous EQOs is based on the prevention of eutrophication,
which is typically not a major concern in a marine receiving environment. Consideration should be
given to the cost versus benefit of achieving these EDOs.
Aluminum
The EDO for aluminum was equal to the background concentration of 0.274 mg/L as the background
concentration was greater than the generic EQO of 0.1 mg/L. However, this EQO is likely overly
conservative as it is based on the CCME CWQG for the protection of aquatic life for freshwater.
There is no CCME CWQG for marine waters. There is no US EPA or BC MOE salt water quality
criterion for aluminum. Therefore, the CCME freshwater guideline was utilized in the absence of a
more appropriate guideline. However, use of the background value for the EDO results in no dilution
being available. In addition, some aluminum removal will likely occur during treatment.
Iron
The EDO for iron was equal to the background concentration of 0.393 mg/L as the background value
was greater than the generic EQO of 0.3 mg/L. However, this EQO is likely overly conservative as it
is based on the CCME CWQG for the protection of aquatic life for freshwater. There is no CCME
CWQG for marine waters. There is no US EPA or BC MOE salt water quality criterion for iron.
Therefore, the CCME freshwater guideline was utilized in the absence of a more appropriate
guideline. However, use of the background value for the EDO results in no dilution being available.
In addition, some iron removal will likely occur during treatment.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 45
CHAPTER 6 COMPLIANCE MONITORING
The Standard Method utilizes the results of the ERA to recommend parameters for compliance
monitoring according to the following protocol:
The WSER requirements for TSS, CBOD and unionized ammonia must be monitored to
ensure they are continuously being achieved. Minimum monitoring frequencies are
specified in the guidelines based on the size of the facility. Monitoring of these
substances cannot be reduced or eliminated;
Nutrients, such as phosphorus and ammonia, and pathogens for which an EDO was
developed should be included in the monitoring program with the same sampling
frequency as TSS and CBOD5;
For additional substances, the guidelines require that all substances with average effluent
values over 80% of the EDO be monitored;
If monitoring results for the additional substances are consistently below 80% of the EDO,
the monitoring frequency can be reduced;
If average monitoring results subsequently exceed 80% of the EDO, monitoring frequency
must return to the initial monitoring frequency; and
If monitoring results are below 80% of the EDO for at least 20 consecutive samples spread
over a period of at least one‐year, monitoring for that substance can be eliminated.
Although the Standard Method results in recommending parameters for compliance monitoring, the
provincial regulator ultimately stipulates the compliance monitoring requirements as part of the
Approvals to Operate. In New Brunswick, the New Brunswick Department of Environment and Local
Government has been using the results of the ERA to update the compliance monitoring program
listed in the Approval to operate when the existing Approvals expire. At this time, it is premature to
use the results of this ERA to provide recommendations on parameters to monitor for compliance,
as the purpose of this ERA was to provide design criteria for design of a new WWTP.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 46
CHAPTER 7 REFERENCES
ASA Consulting Limited (1994). “Industrial Cape Breton Receiving Water Study, Phase II”. Prepared
for The Town of Glace Bay.
BC Ministry of Environment (2006). A Compendium of Working Water Quality Guidelines for
British Columbia. Retrieved from: http://www.env.gov.bc.ca/wat/wq/BCguidelines/working.html
CBCL Limited (2005). Dominion Beach Sewer Study. Prepared for CBRM.
CCME (2008). Technical Supplement 3. Canada‐wide Strategy for the Management of Municipal
Wastewater Effluent. Standard Method and Contracting Provisions for the Environmental Risk
Assessment.
CCME (2007). Canadian Guidance Framework for the Management of Nutrients in Nearshore
Marine Systems Scientific Supporting Document.
CCME Canadian Environmental Quality Guidelines Summary Table. Water Quality Guidelines for the
Protection of Aquatic Life.
Environment Canada (2006). Atlantic Canada Wastewater Guidelines Manual for Collection,
Treatment, and Disposal
Environment Canada (Environment Canada) (1999). Canadian Environmental Protection Act Priority
Substances List II – Supporting document for Ammonia in the Aquatic Environment. DRAFT –August
31, 1999.
Fisher et al. (1979). Mixing in Inland and Coastal Waters. Academic Press, London.
Fisheries Act. Wastewater Systems Effluent Regulations. SOR/2012‐139.
Health Canada (2012). Guidelines for Canadian Recreational Water Quality. Retrieved from:
http://www.hc‐sc.gc.ca/ewh‐semt/pubs/water‐eau/guide_water‐2012‐guide_eau/index‐eng.php
Mixing Zone Assessment and Report Template Draft only – For discussion (July 7, 2016)
NB Department of Environment & Local Government, (2012). Memo.
Harbour Engineering Joint Venture Glace Bay WWTP ERA 47
Thomann, Robert V. and Mueller, John A (1987). Principles of Surface Water Quality Modeling and
Control.
UMA (1994). Industrial Cape Breton Wastewater Characterization Program, Phase II.
USEPA. National Recommended Water Quality Criteria for Saltwater. Retrieved from:
http://water.epa.gov/scitech/swguidance/standards/criteria/current/index.cfm
Prepared by: Reviewed by:
Holly Sampson, M.A.Sc., P.Eng. Karen March, M.Sc.
Intermediate Chemical Engineer Environmental Scientist
Harbour Engineering Joint Venture Appendices
APPENDIX A
Laboratory Certificates
HEJV Glace Bay Wastewater System Pre‐Design Summary Report Appendices
APPENDIX D
Glace Bay Wastewater Treatment Facility
Site Geotechnical Reports
GLACE BAY WWTP GEOTECHNICAL SUMMARY LETTER - 02 MAR 2020.DOCX/WD ED: 3/2/2020 3:59:00 PM/PD: 3/2/2020 3:59:00 PM
March 2, 2020
Matthew D. Viva, P.Eng.
Manager of Wastewater Operations
Cape Breton Regional Municipality (CBRM)
320 Esplanade, Sydney, NS B1P 7B9
Dear Mr. Viva:
RE: Environmental Risk Assessments & Preliminary Design of Seven Future Wastewater
Treatment Systems in CBRM - Glace Bay WWTP Site Location Geotechnical Summary
Harbour Engineering Joint Venture (HEJV) is pleased to provide the following summary of
geotechnical investigation work at the proposed site of the Glace Bay Wastewater Treatment
Plant (WWTP) as part of the Environmental Risk Assessments & Preliminary Design of Seven
Future Wastewater Treatment Systems in CBRM Project.
Background
HEJV’s proposal for the geotechnical component of this assignment was originally based on the
requirements contained in the related Request for Proposal (RFP) document P17-2017 and
associated Addendums issued by the CBRM, which had specified the inclusion of a desktop
geotechnical review. In addition, HEJV’s proposal contained some unique and innovative
approaches that were believed to be helpful to CBRM in meeting its overall schedule for
implementing wastewater collection and treatment system upgrades. One of these innovative
and optional items was the inclusion of an intrusive geotechnical investigation of treatment plant
sites for the Glace Bay and Port Morien systems.
HEJV is aware that the Town of Glace Bay has been extensively undermined through former coal
mining operations. Two coal seams in particular underlie the Glace Bay WWTP site - the Harbour
Seam and the Phalen Seam. The Harbour Seam was actively mined between 1872 and 1896, while
Phalen Seam was actively mined from 1900 to 1949. Both seams have the potential to impact the
development of the Glace Bay WWTP as voids could be present in either seam below the proposed
development.
Desktop Geotechnical Review
The initial geotechnical work carried out by HEJV at the Glace Bay site was a desktop geotechnical
investigation. The related report laid out the groundwork for the intrusive geotechnical program
that would follow. The report entitled “Wastewater Treatment Plant Geotechnical Desktop Study
Glace Bay Site’, dated October 15, 2018 is attached to this document in Appendix A. The report
provides background on the WWTP site, including general topography, published geological
mapping, existing ground conditions, geotechnical problems and parameters and provides a
proposed supplemental ground investigation method.
Matthew D. Viva, P.Eng.
March 2, 2020
Page 2 of 4
GLACE BAY WWTP GEOTECHNICAL SUMMARY LETTER - 02 MAR 2020.DOCX/WD ED: 3/2/2020 3:59:00 PM/PD: 3/2/2020 3:59:00 PM
Intrusive Geotechnical Investigation Program #1
Next, an intrusive geotechnical program was undertaken following the above noted desktop
geotechnical study. The report entitled “Geotechnical Investigation – WWTP Glace Bay Sites” was
completed by exp Services Inc. on February 4, 2019 and is attached in Appendix B to this
document. The intrusive geotechnical program reviewed surface and sub-surface conditions and
provided discussion and recommendations on site development, excavations and geotechnical
parameters. The program included drilling six boreholes on two potential Glace Bay WWTP sites.
Three boreholes (BHs 1-3) were drilled on the site north of Beach Street (Site #1). The second set
of three boreholes (BHs 4-6) were drilled on Site #2, northeast of the existing Bayplex (Site #2).
The boreholes for the initial intrusive investigation were advanced to a depth of 15.5 to 31.5m to
confirm sub-surface conditions. As these boreholes were not advanced far enough to reach the
coal seam, HEJV commissioned exp Services Inc. to re-drill two boreholes to confirm sub-surface
conditions to the depth of the underlying Harbour seam. BHs 4A and 6A were completed to a
depth of 55-60m from surface.
The results from the initial drilling program indicated a void was present in BH 6A at a depth of
50.5m from surface, while BH 4A did not encounter a void. Exp Services Inc. updated their original
intrusive investigation report noted above with a supplemental report contained in Appendix C
entitled “Wastewater Treatment Plant Geotechnical Evaluation Glace Bay Site”, dated April 15,
2018. This supplemental report added further evaluation of the underlying soil mechanics and
ramifications of underground voids beneath the site. The report provided risk of subsidence levels
for each site. For Site #1 the report considered the area to have a low to moderate risk of
subsidence while Site #2 was classified as high risk. To mitigate the risks at Site #2, the following
methods were suggested for construction of the WWTP:
→ Design the proposed structure to be able to withstand signification ground movements (a
thick concrete slab below the structure sitting on a layer of compacted sand).
→ Support the facility on drilled steel pipe piles filled with concrete or piles socketed into
the floor of the Harbour Seam.
→ Form concrete pillars in historical mine workings (Harbour Seam) on a grid system below
the facility.
→ Re-orientating the WWTP buildings on the site to lessen the potential of being positioned
over the Harbour Mine workings. Re-orientation was recommended to be followed by
further intrusive investigation.
Some of the above noted mitigation measures are deemed to carry significant capital costs,
particularly the options involving drilling steel pipe piles or forming concrete pillars into the floor
of the underlying coal seam.
Intrusive Geotechnical Investigation Program #2 (Rock Mechanics Analysis)
HEJV then recommended another intrusive geotechnical investigation program intended to
determine whether the rock layers between the proposed WWTP and existing voids could
effectively bridge the weight of the WWTP structures, such that the level of risk to develop the
site would be reduced. CBRM provided authorization to proceed with this program and
Matthew D. Viva, P.Eng.
March 2, 2020
Page 3 of 4
GLACE BAY WWTP GEOTECHNICAL SUMMARY LETTER - 02 MAR 2020.DOCX/WD ED: 3/2/2020 3:59:00 PM/PD: 3/2/2020 3:59:00 PM
subsequently, another drilling program was undertaken involving four new boreholes advanced
to coal seam depths (2 boreholes were drilled on each of the two proposed sites). The report
related to this investigation entitled “Rock Mechanics Investigation Proposed Waste Water
Treatment Plants Glace Bay, Nova Scotia”, dated January 29, 2019 is provided in Appendix D. The
analysis involved a rock-mass assessment and failure mechanisms for the project site. The analysis
also provided a subsidence analysis and recommendations on foundation design for the proposed
structures. During the associated borehole program, a borehole advanced on Site #2 indicated
another sub-surface void. Borehole RMS2 encountered a void approximately 53.5m from surface.
The remaining three boreholes were advanced through the coal seam and indicated the seam was
still intact (no voids were encountered).
The rock mechanics analysis resulted in a lower characterisation of the level of subsidence risk for
each of the prospective sites as compared to previous assessments. For Site #1 the report
considered the site to carry a very low risk, while Site #2 was denoted as low risk. The level of risk
at Site #1 was lowered due to the fact that voids had not been encountered on the site by any of
the intrusive field programs. Site #2 was considered to be riskier than Site #1 due to the fact that
voids have been found during two different intrusive field programs. The risk classification process
used takes into account the bridging ability of the underlying rock below the future WWTP. The
report also discusses that the risk level for Site #2 could be lessened by a re-orientation of the
WWTP, but this would need to be confirmed with additional intrusive investigation.
The rock mechanics analysis provided recommendations for foundation design for each site,
which varied in consideration of the level of risk at each of the sites. For Site #1, it was suggested
that foundations be designed to withstand a potential differential settlement of 25mm while for
Site #2, a design value for differential settlement of 75mm was recommended. HEJV reviewed
foundation design recommendations and decided that foundations could not be reasonably
designed to withstand a differential settlement of 75mm without pile foundations.
HEJV posed a number of questions about the rock mechanics analysis to exp Services Inc. to
further define some of the statements in the report. The corresponding answers from exp Services
Inc. are provided in Appendix E.
Recommendations
At this time HEJV is recommending that the Glace Bay WWTP structures be placed on Site #1
based on the above “very low” risk subsidence classification. Generally, it is recommended that
structures be placed east of a zone 25 metres from Borehole 6A as suggested by exp Services Inc.
in the documents in Appendix E.
HEJV cautions that there is still uncertainty with regard to the presence or absence of
underground mine workings and corresponding voids beneath Site #1. In particular, a document
containing notes from Louis Frost describing coal mining in the area states the following:
“This was a shaft mine opened in 1872 by the Glace Bay Mining Company in the location now
known as the Sterling Yard, to work the extension of the Harbour Seam originally worked by the
old Harbour Mine located in the vicinity of Glace Bay Brook.
Matthew D. Viva, P.Eng.
March 2, 2020
Page 4 of 4
GLACE BAY WWTP GEOTECHNICAL SUMMARY LETTER - 02 MAR 2020.DOCX/WD ED: 3/2/2020 3:59:00 PM/PD: 3/2/2020 3:59:00 PM
The Sterling Mine was operating at the time it was acquired by the Company, but was permanently
closed in 1896 after working all the recoverable coal within the Town area, a large proportion of
which underlay the present business section of the town. The coal was mined by a room and pillar
system. The smallness of the pillars left to support the surface has been a large factor in the heavy
surface subsidence within the town area.”
HEJV cautions that the above description from Frost indicates that all recoverable coal within the
Town area had been worked or recovered, suggesting that voids under Site #1 are a possibility,
despite the absence of voids encountered in any of the boreholes advanced on the site. Therefore,
HEJV recommends completing an additional borehole program during the detailed design of the
Glace Bay WWTP to further explore the site further to assess if subsurface voids are present
beneath the footprint of proposed structures.
If you have any questions or require clarification on the content presented in the attached report,
please do not hesitate to contact us.
Yours very truly,
Harbour Engineering Joint Venture
Prepared by: Prepared by:
James Sheppard, P.Eng. Darrin McLean, MBA, FEC, P.Eng.
Civil Infrastructure Engineer Senior Municipal Engineer
Direct: 902-562-9880 Direct: Direct: 902-539-1330 (Ext. 3138)
E-Mail: jsheppard@dillon.ca E-Mail: dmclean@cbcl.ca
Dillon Project No: 187116.00
CBCL Project No: 182402.00
This document was prepared for the party indicated herein. The material and information in the document reflects HEJV’s opinion and best judgment
based on the information available at the time of preparation. Any use of this document or reliance on its content by third parties is the responsibility of the
third party. HEJV accepts no responsibility for any damages suffered as a result of third party use of this document.
Appendix A – Wastewater Treatment Plant Geotechnical Desktop Study
Glace Bay Site
October 15, 2018 SYD-00245234-A0/60.2
Mr. Terry Boutilier
Dillon Consulting Limited
275 Charlotte Street
Sydney, NS B1P 1C6
Re: Wastewater Treatment Plant Geotechnical Desktop Study
Glace Bay Site
Dear Mr. Boutilier:
It is the pleasure of EXP Services Inc. (EXP) to provide Dillon Consulting Limited (Dillon) with this letter
summarizing the preliminary review completed by EXP on the potential site for the construction of a
wastewater treatment facility in Glace Bay, Nova Scotia.
Background
A geotechnical desktop study is an essential tool used by engineers to identify and gather as much
information as possible pertaining to the probable ground conditions at a proposed construction site
without commissioning an intrusive ground investigation. The information obtained from the desktop
study will identify potential problems, hazards and/or constraints associated with the probable ground
conditions in the proposed area of construction, as well as provide geotechnical recommendations for
new construction activities. When a walkover survey is completed in conjunction with the desktop
study it will allow engineers to refine and enhance their understanding of each of the sites in relation
to the topography, earth exposures, drainage conditions, etc. When completed together (the desktop
study and the walkover survey), the findings will provide invaluable information in the early stages of
the design at a negligible cost. It is the intent of the desktop study and walkover survey not only to look
at the site, but also at its surroundings. Noted below are the key findings to be reported in any desktop
study and walkover assessment:
• site topography;
• geology (surficial ground cover, probable overburden soil and bedrock type);
• geotechnical problems and parameters;
• previous land use (aerial photographs);
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• underground/surface mining activities; and
• proposed supplemental ground investigation methods (test pits and/or boreholes).
Subject Site Description and Topography
The proposed site for the new wastewater treatment plant (WWTP) is located at Fishermans’ Memorial
Park off of Lower North Street in Glace Bay, Nova Scotia and is identified by PID Number 15864085. The
subject property is relatively level, but drops off at the eastern (steeply along coastline), southern
(steeply adjacent to the fish plant) and western (gently adjacent to Beech Street) edges of the property.
The property is bound by the Atlantic coastline along the eastern portion of the site; commercial
buildings, Bell Street and Glace Bay Harbour along the southern portion of the site; Beech Street along
the western portion of the site; and Lower North Street along the northern portion of the site. Figure 1
depicted below outlines the proposed location of the site.
Figure 1: Proposed location of the new WWTP at Fishermans’ Memorial Park.
Published Geological Mapping (Surficial and Bedrock)
Review of the surficial geological mapping of the study area indicated that the subsurface geology
consists of a Stony Till Plain. This type of till is generally comprised of a stony, sandy matrix material
with varying amounts of cobbles and boulders and can vary in thickness from 2 to 20 metres thick.
Typically, these materials were released from the base of ice sheets during the melting process of the
ice sheet.
A review of the existing bedrock mapping for the area indicates that the site is underlain by materials
from the late carboniferous period, which are identified in this area as material from the Sydney Mines
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Formations of the Morien Group. These formations are comprised of fluvial and lacustrine mudstone,
shale, siltstone, limestone and coal.
A review of historical mapping and online reference documents indicated that mining activities have
been carried out extensively in the area proposed for construction. These workings were the standard
room and pillar coal extraction process. It should be noted that pillars may have been mined at some
point during mining activities. Mapping indicates that the site is just north and east of the Harbour
Seam and southeast of the Hub Seam outcroppings.
Existing Ground Conditions
At the time of the investigation, the site was primarily covered in either a mechanically crushed
aggregate (used as roadway around the perimeter of the site, as well as for access) and manicured
grassed areas (which would suggest that the surface of the site would have been reworked at some
point). The overburden soil (fill/glacial till) exposure was observed along the cliffside. The thickness of
the overburden appears to be in the range of 0.3 to 1.8 metres thick. The glacial till was visually
described as being a silty SAND with gravel and varying amounts of cobbles. The till mixture is in a
compact state of relative density. The till should provide satisfactory bearing stratum for the support
of shallow foundations with bearing capacities between 150 and 200 kPa. The underlying bedrock
would provide a higher capacity for allowable bearing.
The bedrock underlying the till was also observed along the cliffside. The exposed bedrock consisted of
alternating layers of shale, mudstone, sandstone and/or siltstone. The formations are consistent with
the material identified in the regional mapping. The exposed bedrock along the Atlantic coastline is
showing evidence of erosion.
Geotechnical Problems and Parameters
Summarized below are the key geotechnical problems of the site.
• Erodibility of subsurface soils and exposed bedrock along the Atlantic coastline.
• The area under the site was undermined due to historical coal mining activities and there is a
potential for undocumented bootleg pits/mines.
• There is the potential for a layer of limestone to be present underlying the surficial ground and
alternating layers of bedrock below the site. Limestone is water soluble and has the potential
to develop karsts voids (sinkholes).
• The presence of uncontrolled fills on the site due to historical activities on the site.
Previous Land Use
Aerial photographs from 1947 to 2018 have been reviewed and summarized below.
• An aerial photograph taken in 1930 depicts the site void of any structures. Several small
buildings are visible along Beech Street, as well as along the southeastern perimeter of the site.
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• An aerial photograph taken in 1947 depicts the site void of any building structures. An access
roadway crosses the site from the intersection of Lower North Street and Beech Street and
heads toward the Glace Bay Harbour wharf. The majority of the site is covered in low-lying
vegetation.
• An aerial photograph taken in 1963 depicts the site still void of any building structures. The
access roadway identified in 1947 has expanded in width and now connects to the intersection
of Beech and Main Streets. A new building has been constructed along the eastern perimeter
of the site.
• An aerial photograph taken in 1973 depicts little to no change since 1963. The surrounding
properties show evidence of increased development.
• An aerial photograph taken in 1977 depicts continual development of the properties
surrounding the site.
• An aerial photograph taken in 1993 depicts the site very similar to the site at the time of the
investigation. New breakwater was constructed on the northern side of the harbour.
• An aerial photograph taken in 2003 shows no change to the site.
Proposed Supplemental Ground Investigation Methods
It is also recommended that a preliminary geotechnical investigation (land-based drilling program) be
completed at the site to verify the presence or absence of authorized and/or bootleg mining activities
undertaken in these areas, as well as the potential of future subsidence that could impact structures
constructed on the site.
Ultimately, the goal of the supplemental geotechnical ground investigation is to collect pertinent
information pertaining to the subsurface conditions within the footprint of the proposed new facility.
This information will then be used to develop geotechnical recommendations for use in the design and
construction of the new facility.
Borehole locations should be selected based upon the location of buried infrastructure (sewer, water,
electrical and fiber optic lines); the required distance needed from overhead power lines to
accommodate drilling operations; and to provide adequate coverage of the site. It is proposed that
representative soil samples be collected continually throughout the overburden material of each of the
three boreholes advanced at each site. Additionally, it is recommended that during the investigation
samples of the bedrock should be collected continuously to a depth of at least 30.5 metres or more,
depending upon the elevation to underground mine working within the subject area, in two of the
three boreholes. The intent of the bedrock coring is to:
• verify the presence or absence of underground mine workings (both authorized commercial
activities and/or bootleg pits).
• increase the odds of advancing the borehole through the roof of any mine working (to
determine the potential void space) and not into a supporting pillar.
• accurately characterize the bedrock for design of either driven or drilled piles, if needed.
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It is recommended that the third borehole be terminated either at 12 metres depth below ground
surface or once refusal on assumed bedrock is encountered (whichever comes first). It should be noted
that if pillar extraction took place, fractures will likely extend 20 metres above mine workings. If this is
the case, drill return water may be lost and rock wedges may be encountered. This will inhibit coring
and an alternative method of drilling through fractured rock may have to be examined.
A Geotechnical Engineer should oversee the advancement of each of the boreholes. A CME 55 track
mounted geotechnical drill rig (or equivalent) equipped with bedrock coring equipment and a two-man
crew (driller and helper) should be used to advance each of the boreholes. Representative soil samples
should be attained from a 50 mm diameter standard split spoon sampler during Standard Penetrating
Tests (SPT) conducted ahead of the casing and/or auger equipment. A preliminary assessment of each
recovered sample should be completed for particle size, density, moisture content and color. The SPT
should continue until refusal or contact with assumed bedrock. Bedrock should be confirmed through
coring of the material using coring equipment and drill casing. Each core sample should be removed
from the core barrel and placed into core boxes for identification.
Upon completion of the intrusive portion of the program, all boreholes are to be plugged (at various
depths within the borehole) using a bentonite plug and backfilled to grade using silica sand. It should
be noted that continuous grouting (with neat cement and/or bentonite) may be required to backfill the
boreholes to grade. The continuous grouting will protect water supplies from contamination sources;
it can prevent the movement of water between aquifers; and prevent and stabilize the water-soluble
bedrock that may be present on the site. Following the installation and backfilling activities, the location
and elevations are to be determined using Real Time Kinematic (RTK) survey equipment in the AST 77
coordinate system.
This letter report is prepared for the Glace Bay site. Should you have any questions or concerns, please
contact John Buffett or Gary Landry at 902.562.2394.
Sincerely, Sincerely,
John Buffett, P.Eng., B.Sc., RSO Gary Landry, P.Eng., B.Sc.
Project Engineer Project Manager
EXP Services Inc.
Appendix B – Geotechnical Investigation – WWTP Glace Bay Sites
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
Type of Document:
Final
Project Name:
Seven Wastewater Treatment Plant Geotechnical Desktop Study and
Investigations
Project Number:
SYD-00245234-A0
Prepared By:
John Buffett, B.Sc., P.Eng., RSO
Jamie Harper, P.Eng, ARSO
Reviewed By:
Gary Landry, B.Sc., P.Eng.
EXP Services Inc.
301 Alexandra Street
Sydney, NS B1S 2E8
Canada
T: +1.902.562.2394
F: +1.902.564.5660
www.exp.com
Date Submitted:
February 2019
Geotechnical Investigation – WWTP Glace Bay Sites
Dillon Consulting Limited
Type of Document:
Final
Project Name:
Seven Wastewater Treatment Plant Geotechnical Desktop Study and Investigation
Project Number:
SYD-00245234-A0
Prepared By:
John Buffett, P.Eng., B.Sc., RSO
Reviewed By:
Jamie Harper, P.Eng., ARSO
EXP Services Inc.
301 Alexandra Street, Suite A
Sydney, Nova Scotia B1S 2E8
Canada
T: +1.902.562.2394
F: +1.902.564.5660
www.exp.com
Date Submitted:
2019-02-01
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
i
Legal Notification
This report was prepared by EXP Services Inc. for the account of Dillon Consulting Limited.
Any use which a third party makes of this report, or any reliance on or decisions to be made based
on it, are the responsibility of such third parties. EXP Services Inc. accepts no responsibility for
damages, if any, suffered by any third party as a result of decisions made or actions based on
this report.
EXP Quality System Checks
Project No.: SYD-00245234-A0
Date: February 4, 2019
Type of Document: Final
Revision No.: 0
Prepared By: John Buffett, B.Sc., P.Eng., RSO
Jamie Harper, P.Eng., ARSO
Reviewed By: Gary Landry, B.Sc., P.Eng.
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
TOC-i
Table of Contents
1 Introduction ............................................................................................................................... 1
2 Site Description .......................................................................................................................... 1
3 Field Work .................................................................................................................................. 2
4 Surface and Sub-Surface Conditions ........................................................................................... 4
4.1 Summary of Conditions ..................................................................................................................... 4
4.2 Fill ...................................................................................................................................................... 5
4.3 Glacial Till .......................................................................................................................................... 5
4.4 Residual Soil ...................................................................................................................................... 6
4.5 Bedrock ............................................................................................................................................. 6
4.6 Groundwater ..................................................................................................................................... 6
4.7 Geological Mapping .......................................................................................................................... 6
5 Discussion and Recommendations ............................................................................................. 7
5.1 Site Development .............................................................................................................................. 7
5.2 Excavations ........................................................................................................................................ 8
5.3 Geotechnical Parameters .................................................................................................................. 8
5.1 Structural Fill ..................................................................................................................................... 9
6 Limitations ............................................................................................................................... 10
Appendix 1 Materials Testing Results
Appendix 2 Borehole Logs
List of Tables Page No.
Table 1 Summary of Borehole Locations and Ground Surface Elevations 3
Table 2 Summary of Laboratory Testing Results 4
Table 3 Summary of Sub-Surface Stratigraphy 5
Table 4 Recommended Geotechnical Parameters for Retaining Structures 9
List of Figures Page No.
Figure 1 Proposed Locations of the New WWTP in Glace Bay, Nova Scotia 1
Figure 2 Borehole Locations and Ground Surface Elevations 3
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1 Introduction
EXP Services Inc. (EXP) was retained by Dillon Consulting Limited (Dillon) to carry out a geotechnical
investigation for the construction of a new wastewater treatment plant (WWTP) at one of two
proposed sites in Glace Bay, Nova Scotia.
Ultimately, the goal of this project was to provide information pertaining to the sub-surface conditions
in the vicinity of the proposed facility. This information was used to develop geotechnical
recommendations for use in the design and construction of the new facility. A geotechnical desktop
study of one of the sites was completed by EXP in October 2018. Based on the information obtained
from the study, a preliminary geotechnical drilling program was recommended in order to verify the
presence or absence of authorized and/or bootleg mining activities undertaken in the proposed
subject area, as well as the potential of future subsidence that could impact structures proposed to
be constructed on the site. The scope of the project included the following components.
• Assess the subsurface soil conditions in six boreholes (three at each site).
• Characterize uncontrolled fill, native soils, and bedrock within the proposed development
footprint.
• Determine the ground elevations and locations at each borehole location.
• Collect representative soil and bedrock samples for laboratory testing.
• Prepare a geotechnical report, including borehole logs and geotechnical recommendations
for design.
2 Site Description
The proposed sites are located off of Lower North Street in Glace Bay, Nova Scotia on two separate
lots across the street from one another. Figure 1 outlines the proposed locations of the site.
Figure 1: Proposed Locations of the New WWTP in Glace Bay, Nova Scotia
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The first site, originally reviewed in the desktop study, on the eastern side of Lower North Street is
located within the footprint of Fisherman’s Park and is identified by Property Identification Number
(PID) Number 15864085. The subject property is relatively level but drops off at the eastern (steeply
along coastline), southern (steeply adjacent to the fish plant) and western (gently adjacent to Beech
Street) edges of the property. The property is bound by the Atlantic coastline along the eastern
portion of the site; commercial buildings, Bell Street and Glace Bay Harbour along the southern
portion of the site; Beech Street along the western portion of the site; and Lower North Street along
the northern portion of the site.
The second site is located on a vacant lot on the western side of Lower North Street and is identified
by PID Numbers 15821119, 15395221, 15833007, 15654882 and 15393606. The subject property
slightly slopes from the north to the south. The property is bound by the residential properties along
the northeastern portion of the site; commercial buildings along the south/southwestern portion of
the site; and Lower North Street along the southern portion of the site.
3 Field Work
The fieldwork took place between 03 and 12 January 2019. The geotechnical investigation consisted
of three boreholes at each proposed site. The investigation was carried out using a CME 75 track-
mounted drill rig, supplied and operated by 692691 NB Inc. O/A Lantech Drilling (2016) out of their
operation in Moncton, New Brunswick.
Borehole locations were selected based upon the location of buried infrastructure (sewer, water,
electrical and fiber optic lines); the required distance needed from overhead power lines to
accommodate drilling operations, and to provide adequate coverage of the site. The borehole
locations were adjusted slightly in the field to avoid underground utilities. EXP understands that minor
adjustments to WWTP locations may occur as plans are finalized.
The boreholes were advanced using casing and coring equipment. Representative soil samples were
attained from the 50 mm diameter split spoon sampler during Standard Penetration Tests (SPTs)
conducted ahead of the casing equipment. A preliminary assessment of particle size, density, moisture
and colour was recorded for each soil sample. Rock coring was conducted using HQ sized (63.5 mm
diameter) coring equipment and drill casing. Bedrock was collected continuously in each of the
boreholes to a depth of between 15.4 and 31.4 m below existing grade.
All boreholes were backfilled to the existing surface grade to prevent possible tripping hazards. Sand
and bentonite were used for backfilling to mitigate the potential for surface waters to flow into the
groundwater system at the borehole locations.
The general site locations and the locations of the boreholes at each site are shown on the attached
figure, labelled Figure 2.
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Figure 2: Borehole Locations and Ground Surface Elevations
The borehole location information and ground surface elevations are summarized in Table 1.
Coordinates are referenced to the NAD83 (CSRS 2010) System.
Table 1: Summary of Borehole Locations and Ground Surface Elevations
Borehole Location Northing (m) Easting (m) Elevation (m)
BH#1 5118741 24619582 7.22
BH#2 5118794 24619597 6.94
BH#3 5118782 24619548 7.62
BH#4 5118887 24619504 10.47
BH#5 5118838 24619480 10.10
BH#6 5118903 24619462 11.92
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Recovered samples from the field investigation were reviewed in the laboratory by an EXP Engineer
to confirm soil boundaries and descriptions. Representative samples from different soil strata were
selected for laboratory analysis. The following tests were carried out:
• Moisture Content testing was conducted on two soil samples;
• Gradational Analysis testing was conducted on two soil samples to classify soil strata; and
• Compressive Strength testing was conducted on eight core samples.
The results of all geotechnical laboratory tests are summarized in Table 2. Copies of all laboratory
testing plots and detailed test sheets have been included in Appendix 1.
Table 2: Summary of Laboratory Testing Results
Borehole
Location
Split Spoon
ID
Percent
Gravel
Percent
Sand Percent Fines
Moisture
Content
(%)
BH#4 SS#3 39.7 25.8 34.4 9.2
BH#6 SS#2 12.0 57.3 30.6 16.9
Borehole
Location Rock Core ID Depth Below Grade
(m)
Load
(kN)
Compressive
Strength
(MPa)
BH#1 RC#7 9.75 74.0 23.4
BH#1 RC#17 25.91 72.8 23.0
BH#2 RC#11 14.64 61.9 19.6
BH#2 RC#15 22.25 113.0 35.7
BH#3 RC#9 13.41 119.0 37.6
BH#4 RC#15 22.99 122.8 38.8
BH#5 RC#7 9.75 99.8 31.5
BH#5 RC#10 14.02 85.7 27.1
4 Surface and Sub-Surface Conditions
4.1 Summary of Conditions
The general stratigraphy encountered on the sites included the following:
• Fill
• Glacial Till
• Residual Soil
• Sedimentary Bedrock
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A summary of the thicknesses of the various strata encountered during the investigation is provided
in Table 3. Detailed borehole logs are provided in Appendix 2 and summary descriptions of the soil
are given below in subsequent sections.
Table 3: Summary of Sub-Surface Stratigraphy
Borehole ID Thickness of Fill
(m)
Thickness of Till
(m)
Thickness of
Residual Soil
(m)
Elevation to
Bedrock
(m)
BH#1 4.9 0.6 n/a 1.7
BH#2 3.4 0.5 n/a 3.0
BH#3 3.9 0.3 n/a 3.4
BH#4 3.2 1.5 3.1 2.7
BH#5 3.4 0.6 0.3 6.1
BH#6 3.4 0.6 0.9 4.6
Notes: n/a refer to not applicable
m – metres
4.2 Fill
Various types of uncontrolled fill material were encountered in all of the boreholes drilled at both
sites. Visually the fill material was described as:
• ‘Silty SAND and GRAVEL’ Reworked Till in borehole BH#1;
• ‘Silty SAND’ Reworked Till in boreholes BH#2 and BH#3;
• ‘Silty GRAVEL’ in borehole BH#4; and
• “Sandy SILT and GRAVEL’ in boreholes BH#5 and BH#6.
The fill was found to be in very loose to compact state of relative density, moist to wet in terms of
moisture content and black to brown/olive brown in colour. It should be noted that varying amounts
of cobbles and debris (waste rock, coal, concrete brick) were encountered within the fill materials.
4.3 Glacial Till
A layer of Glacial Till was found in all of the boreholes drilled at both sites. Visually the till material
was described as being a ‘Silt SAND and GRAVEL with trace cobbles’. Under the Unified Soil
Classification System (USCS) the glacial till was classified as ‘Silty SAND’ (SM) in borehole BH#6 SS#2.
The glacial till was found to be in compact to dense state of relative density, moist to wet in terms of
moisture content, and brown/olive brown to grey in colour. It should be noted that varying amounts
of cobbles were encountered within the till materials.
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4.4 Residual Soil
A layer of residual soil was found in three (BH#4, BH#5, and BH#6) of the six boreholes drilled at both
sites. Under the USCS classification the residual soil was classified as ‘Silty GRAVEL and SAND’ (GM) in
borehole BH#4 SS#3.
The residual soil was found to be in a dense state of relative density, moist in terms of moisture
content, and dark grey in colour.
4.5 Bedrock
Alternating layers of sedimentary bedrock (siltstone/sandstone/mudstone) was observed in each of
the boreholes installed across both sites. Review of the bedrock core samples indicated that the
material was weathered and highly fractured in areas. Based on Rock Quality Designation (RQD), the
quality of the bedrock alternated between very poor to good quality. Compressive strength testing
on select samples indicated that the bedrock ranged from weak to medium strong.
4.6 Groundwater
Groundwater was only encountered in borehole BH#1 at an elevation of 2.4 m. It should be noted that
groundwater conditions vary seasonally and in response to recent precipitation events. The boreholes
advanced during this investigation represent a limited sampling of the sites. Although limited
quantities of groundwater were encountered during the current study, it is possible that more
substantial amounts of groundwater may be encountered in mass excavation for construction.
4.7 Geological Mapping
Review of the surficial geological mapping of the study area indicated that the subsurface geology
consists of a Stony Till Plain. This type of till is generally comprised of a stony, sandy matrix material
with varying amounts of cobbles and boulders and can vary in thickness from 2 to 20 m thick. Typically,
these materials were released from the base of ice sheets during the melting process of the ice sheet.
The native till materials encountered at both sites is consistent with the geological mapping.
A review of the existing bedrock mapping for the area indicates that the site is underlain by materials
from the late carboniferous period, which are identified in this area as material from the Sydney Mines
Formations of the Morien Group. These formations are comprised of fluvial and lacustrine mudstone,
shale, siltstone, limestone and coal. The bedrock materials encountered at both sites is consistent
with the geological mapping.
A review of historical mapping and online reference documents indicated that mining activities have
been carried out extensively in the area proposed for construction. These workings were the standard
room and pillar coal extraction process. It should be noted that pillars may have been mined at some
point during mining activities. Mapping indicates that the site is just north and east of the Harbour
Seam and southeast of the Hub Seam outcroppings.
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
7
5 Discussion and Recommendations
The following geotechnical recommendations are based on the information obtained through the
advancement of six boreholes across the subject properties. Given the information available at the
time of this report, the key geotechnical considerations for the development of the site include the
following.
• The presence of mine workings below the subject property gives rise to the potential for
future subsidence, which could impact structures resulting in significant settlements over
time.
• The presence of uncontrolled fill within the footprint of the new facilities should be
excavated and replaced with compacted engineered fill. Since the history of development is
unknown, fill may be present to greater depths than was encountered at the borehole
locations. Careful inspection of the base of the excavations and proof rolling with
appropriately sized equipment will be important to confirm the suitability of the bearing
material. The native glacial till materials beneath the fill should provide a suitable bearing
stratum.
• Groundwater and surficial water control (north side of Lower North Street) should be
planned for during construction to avoid softening of the fill and native glacial till soils.
Similarly, protection of exposed sub-grade and compacted fill surfaces against freezing and
thawing should be planned for.
5.1 Site Development
Any surficial rootmat, topsoil, fills and construction debris should be stripped from the new building’s
footprint, roadways and parking lot areas in order to expose the underlying native till layer. The
surface of the till should be proof rolled with a larger vibratory roller compactor (and/or equivalent)
to identify any potential soft areas. Any areas that exhibit excessive displacement should be over
excavated and backfilled with an engineered fill in compacted lifts. It is recommended that during the
placement of backfills a Geotechnical Engineer or their designate should be on-site to oversee the
placement methods used by the Contractor.
Select portions of the excavated till/fill may be suitable for use as an engineered fill in building the
sub-grade beneath paved roads or in parking lot areas, subject to approval by the Engineer. However,
these materials can be very difficult to work with in wet or cold conditions and are not compactable
above their optimum moisture content with standard equipment.
It may not be possible to use vibration during construction of the sub-grade or fills until the surface
being compacted is well above the level of groundwater. The vibratory action has the potential to
draw water towards the surface and lower the workability of the sub-grade/fill material. The level at
which vibration may be used to assist in compaction will need to be determined in the field during
compaction activities on the basis of the results of proof rolling and compaction testing. The
Geotechnical Engineer or their designate should be on-site to observe the placement and compaction
methods of fills for new construction.
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
8
Construction activities should be carried out in accordance with Nova Scotia Environment’s “Erosion
and Sedimentation Control: Handbook for Construction Site”. Due to the fine-grained nature of the
glacial till/reworked till/fills encountered during the investigation, the control of site construction
water will be important. Exposed soil surfaces will be susceptible to erosion. Hydro-seeding, the
installation of sod, armor stone (along coast line) or other erosion control measures should be
constructed on permanent excavated slopes and stripped non-traffic areas to combat soil erosion.
The grade of the completed ground surface on-site should be sloped such that any and all surface
waters will be diverted away from the completed structure.
5.2 Excavations
If temporary excavations exceeding 1.2 m depth are required for construction, maximum temporary
side slopes of 1:1 (Horizontal:Vertical) should be maintained, the excavation should be benched, or
engineered shoring installed. Flatter slopes may be required for stability if groundwater is
encountered.
The ground around excavations should be graded to prevent infiltration of surface water into the
excavations. Groundwater was encountered at shallow depth and a groundwater management plan
should be developed and implemented to keep the base of excavation dry for construction. At a
minimum, standard dewatering techniques, such as the sloping of the base of the excavation to allow
for gravity drainage to sumps for pumping operations should be planned for construction. The ground
surface around the excavation should be graded to direct the flow of any surface water away from
the excavation.
It should be noted that the native till layer is fine-grained and susceptible to softening on exposure to
wet or freeze-thaw conditions. Wherever possible, construction activities should be planned to
prevent softening of till/till-fill layer.
5.3 Geotechnical Parameters
5.3.1 Bearing Capacity
Footings founded directly on engineered fill and/or native till may be designed using a net
geotechnical bearing reaction at Serviceability Limit States (SLS) of 150 kPa. Total and differential
settlements of the structure are expected to be less than 25 mm and 15 mm, respectively, at this level
of applied bearing pressure. A factored net geotechnical bearing resistance and Ultimate Limit States
(ULS) of 200 kPa may be used. This includes a geotechnical resistance factor of 0.5. For footings on
native glacial till deposit, a minimum of a 300 mm thick layer of structural fill (150 mm or 100 mm
minus well graded, quarried material) should be considered below the footings. The structural fill will
provide a stable working area for footing construction. This should be reviewed during construction.
A 100 mm thick mud slab could be used as an alternative to the 300 mm thick granular layer.
Footings should be founded at least 1.2 m below finished exterior grades for frost protection.
Alternatively, foundation depths may be reduced if an insulation detail is incorporated in the design.
EXP would be pleased to establish an insulation detail upon request.
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
9
5.3.2 Geotechnical Parameters for Retaining Structures
The recommended geotechnical parameters for design of elements acting as retaining structures are
summarized in Table 4. These parameters are given assuming that the finished surface behind
retaining structures will be horizontal, and that compacted granular fill will be used as backfill within
the zone of active pressure behind retaining structures. If different types of backfill or inclined slopes
behind structures are planned, the Geotechnical Engineer should be consulted for the appropriate
earth pressure coefficients for design.
Table 4: Recommended Geotechnical Parameters for Retaining Structures
Parameter Compacted Structural (Granular) Fill
Total Unit Weight, kN/m3 21.5
Buoyant Unit Weight, kN/m3 11.5
Effective Friction Angle, degrees 36
Coefficient of Active Earth Pressure, Ka 0.26
Coefficient of Passive Earth Pressure, Kp 3.90
Coefficient of Earth Pressure at Rest, Ko 0.4
Ultimate Friction Coefficient – concrete on granular fill 0.55
Ultimate Friction Coefficient – concrete on sound rock 0.7
Care should be taken not to damage walls when performing backfilling and compaction operations.
Compaction within 1.5 m of retaining structures should be carried out with a walk-behind vibratory
plate roller or plate tamper rather than a large vibratory drum roller.
5.3.3 Site Class for Seismic Response
We recommend that designers use a site class of C for seismic considerations, in accordance with
Table 4.1.8.4.A (Site Classification for Seismic Site Response) in the 2005 National Building Code of
Canada. Note that the site class is based on the average conditions of the ground profile in the upper
30 m of the site.
5.1 Structural Fill
Structural fills should consist of a well-graded, compactable granular material with less than 10% fines
and should be free of organics, soft or elongated particles and other deleterious materials. Typical
suitable structural fills for construction are consistent with Nova Scotia Transportation and
Infrastructure Renewal, Division 3 – Granular Materials for a Type 1, Type 2, and Fill Against Structure.
Other types of fill may be suitable for use, pending approval by the Geotechnical Engineer prior to
use.
All engineered fills should be compacted to a minimum of 98% of the Maximum Dry Density as
determined in a Standard Proctor Test (ASTM D698). The compacted lift thickness should not exceed
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
10
200 mm for fills compacted with a large vibratory drum roller or walk-behind vibratory roller. If a
plate tamper is used for compaction the lift thickness should be reduced to 100 mm.
6 Limitations
This report has been prepared for the sole use of the Dillon Consulting Limited and their agents. The
material within reflects EXP’s best judgement in light of the information available at the time of
preparation. Any use which a third party makes of this report, or any reliance on or decision to be
made based on it, are the responsibility of such third parties. EXP accepts no responsibility for
damages, if any, suffered by any third party as a result of decisions made or actions based on this
report.
If conditions differ from those detailed on the test pit logs are noted during construction, the engineer
should be notified to allow reassessment of any design assumptions, if necessary.
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
Appendix 1 –
Materials Testing Results
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10 100
#200 #100 #60 #40 #10
SAMPLE D10D30D60 %Gravel %Sand %Fines
DEPTH( m)
DEPTH( m)
BH#4
BH#6
Residual Soil
Glacial Till
SAND
fine coarse coarse
GRAVEL COBBLES
U.S. SIEVE NUMBERS
LL Cu
SILT OR CLAY medium fine
HYDROMETER U.S. SIEVE OPENING IN INCHES
P
ERC
ENT
F
INE
R
B
Y
W
EIGHT
GRAIN SIZE IN MILLIMETERS
GRAIN SIZE DISTRIBUTION
#20 #4 3/8" 3/4" 1.5" 6"3"
PISAMPLEClassification (USCS) PLWC% Cc
BH
BH
BH#4
BH#6
9.2
16.9
SS - 3
SS - 2
5.0
3.7
5.0
3.7
SS - 3
SS - 2
Soil Deposit
SILTY GRAVEL with SAND GM
SILTY SAND SM
25.5
56.5
34.4
30.6
4.82
1.02
40.1
12.9
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LOCATION Lower North Street, Glace Bay
PROJECT No.SYD-00245234-A0
CLIENT Dillon Consulting Ltd.
ADI LimitedThe new identity of
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS B3L 2C2
CANADA
http://www.exp.com
Dillon Consulting Limited
Geotechnical Investigation – WWTP Glace Bay Sites
SYD-00245234-A0
February 4, 2019
Appendix 2 –
Borehole Logs
Descriptive Terms - Borehole and Test Pit Logs
Grain Size Clay&Silt
Sand Gravel Cobble Boulder
Compactness N, Range 0 - 4 4 - 10 10 - 30 30 - 50 >50
Soils (gravel, sand, tills)Density V. Loose Loose Compact Dense V. Dense
Consistency S, KPa < 12.5 12.5 - 25 25 - 50 50 - 100 100 - 200
(silt, clay)Consistency V. Soft Soft Firm Stiff V. Stiff
RQD Overall Quality Fracture Spacing
0 - 25 Very Poor < 50 mm Very Close
25 - 50 Poor 50 - 300 mm Close
50 - 75 Fair 0.3 - 1 m Moderate
Rock 75 - 90 Good 1 - 3 m Wide
90 - 100 Excellent > 3 m Very Wide
F M C
0.075 0.425 2.0 4.76 76.4 200
0.01 0.1 1.0 10 100 1000 (mm)
(mm)
y
Comp. Str., MPa 0.25 - 1 1 - 5 5 - 25 25 - 50 50 - 100 100 - 250 > 250
Sample Types (location to scale on log)
SS Split Spoon B Shovel (bulk)
T Shelby Tube H Carved Block
P Piston V In Situ Vane
F Auger NR No Recovery
W Wash
Rock Cores: BQ (36.5mm), NQ (47.6mm), HQ (63.5mm)
Notation and Symbols
N - N-value from standard penetration test; blows by 475 J drop hammer to advance
std. 50mm O.D. split spoon sampler 0.3m
RQD - percent of core consisting of hard, sound pieces in excess of 100mm long (excluding
machine breaks)
Recovery - sample recovery expressed as percent or length
S - shear strength, kPa PL - plastic limit, percent
Sr - shear strength, remoulded LL - liquid limit, percent
Dd - dry density, t/m3 - groundwater level
W - natural moisture content, percent - seepage
Very
Strong
Extremely
StrongDescriptionWeakExtremely
Weak
Very
Weak
Medium
Strong Strong
F M C
0.075 0.425 2.0 4.76 76.4 200
0.01 0.1 1.0 10 100 1000 (mm)
(mm)
SYMBOLS AND TERMS USED ON THE BOREHOLE AND TEST PIT RECORDS
Soil Description
Behavioral properties (i.e., plasticity, permeability) take precedence over particle gradation in
describing soils.
Terminology Describing Soil Structure
Desiccated Having visible signs of weathering by oxidation of clay minerals,
Fissured Having cracks and, hence, a blocky structure
Varved Composed of regular alternating layers of silt and clay
Stratified Composed of alternating layers of different soil type, e.g., silt and sand
Well Graded Having wide range in grain size and substantial amounts of all
Uniformly Graded Predominantly of one grain size
Terminology used for describing soil strata based upon the proportion of individual particle sizes
present:
Trace, or occasional Less than 10%
Some 10–20%
Adjective (e.g., silty or sandy)20–35%
And (e.g., silt and sand)35–50%
The standard terminology to describe cohesionless soils includes the relative density, as
determined by laboratory test or by the Standard Penetration Test “N”-value: the number of blows
of 140 pound (64 kg) hammer falling 30 inches (760 mm), required to drive a 2-inch (50.8 mm) O.D.
splitspoon sampler one foot (305 mm) into the soil.
Relative Density “N” Value Relative Density %
Very Loose <4 <15
Loose 4–10 15–35
Compact 10–30 35–65
Dense 30–50 65–85
Very Dense 50 >85
The standard terminology to describe cohesive soils includes the consistency, which is based on
undrained shear strength as measured by in-situ vane tests, penetrometer tests, unconfined
compression tests, or occasionally by standard penetration tests.
Undrained Shear Strength
Consistency kips/sq. ft. kPa “N” Value
Very Soft <0.25 <12.5 <2
Soft 0.25–.50 12.5–25 2–4
Firm 0.5–1.0 25–50 4–8
Stiff 1.0–2.0 50–100 8–15
Very Stiff 2.0–4.0 100–200 15–30
Hard >4.0 >200 >30
Descriptive Terms - Borehole and Test Pit Logs
Grain Size Clay&Silt
Sand Gravel Cobble Boulder
Compactness N, Range 0 - 4 4 - 10 10 - 30 30 - 50 >50
Soils (gravel, sand, tills)Density V. Loose Loose Compact Dense V. Dense
Consistency S, KPa < 12.5 12.5 - 25 25 - 50 50 - 100 100 - 200
(silt, clay)Consistency V. Soft Soft Firm Stiff V. Stiff
RQD Overall Quality Fracture Spacing
0 - 25 Very Poor < 50 mm Very Close
25 - 50 Poor 50 - 300 mm Close
50 - 75 Fair 0.3 - 1 m Moderate
Rock 75 - 90 Good 1 - 3 m Wide
90 - 100 Excellent > 3 m Very Wide
F M C
0.075 0.425 2.0 4.76 76.4 200
0.01 0.1 1.0 10 100 1000 (mm)
(mm)
y
Comp. Str., MPa 0.25 - 1 1 - 5 5 - 25 25 - 50 50 - 100 100 - 250 > 250
Sample Types (location to scale on log)
SS Split Spoon B Shovel (bulk)
T Shelby Tube H Carved Block
P Piston V In Situ Vane
F Auger NR No Recovery
W Wash
Rock Cores: BQ (36.5mm), NQ (47.6mm), HQ (63.5mm)
Notation and Symbols
N - N-value from standard penetration test; blows by 475 J drop hammer to advance
std. 50mm O.D. split spoon sampler 0.3m
RQD - percent of core consisting of hard, sound pieces in excess of 100mm long (excluding
machine breaks)
Recovery - sample recovery expressed as percent or length
S - shear strength, kPa PL - plastic limit, percent
Sr - shear strength, remoulded LL - liquid limit, percent
Dd - dry density, t/m3 - groundwater level
W - natural moisture content, percent - seepage
Very
Strong
Extremely
StrongDescriptionWeakExtremely
Weak
Very
Weak
Medium
Strong Strong
F M C
0.075 0.425 2.0 4.76 76.4 200
0.01 0.1 1.0 10 100 1000 (mm)
(mm)
SYMBOLS AND TERMS USED ON THE BOREHOLE AND TEST PIT RECORDS
Soil Description
Behavioral properties (i.e., plasticity, permeability) take precedence over particle gradation in
describing soils.
Terminology Describing Soil Structure
Desiccated Having visible signs of weathering by oxidation of clay minerals,
Fissured Having cracks and, hence, a blocky structure
Varved Composed of regular alternating layers of silt and clay
Stratified Composed of alternating layers of different soil type, e.g., silt and sand
Well Graded Having wide range in grain size and substantial amounts of all
Uniformly Graded Predominantly of one grain size
Terminology used for describing soil strata based upon the proportion of individual particle sizes
present:
Trace, or occasional Less than 10%
Some 10–20%
Adjective (e.g., silty or sandy)20–35%
And (e.g., silt and sand)35–50%
The standard terminology to describe cohesionless soils includes the relative density, as
determined by laboratory test or by the Standard Penetration Test “N”-value: the number of blows
of 140 pound (64 kg) hammer falling 30 inches (760 mm), required to drive a 2-inch (50.8 mm) O.D.
splitspoon sampler one foot (305 mm) into the soil.
Relative Density “N” Value Relative Density %
Very Loose <4 <15
Loose 4–10 15–35
Compact 10–30 35–65
Dense 30–50 65–85
Very Dense 50 >85
The standard terminology to describe cohesive soils includes the consistency, which is based on
undrained shear strength as measured by in-situ vane tests, penetrometer tests, unconfined
compression tests, or occasionally by standard penetration tests.
Undrained Shear Strength
Consistency kips/sq. ft. kPa “N” Value
Very Soft <0.25 <12.5 <2
Soft 0.25–.50 12.5–25 2–4
Firm 0.5–1.0 25–50 4–8
Stiff 1.0–2.0 50–100 8–15
Very Stiff 2.0–4.0 100–200 15–30
Hard >4.0 >200 >30
FILL (Reworked Till):
Silty SAND and GRAVEL, some
coal, mudstone, trace cobbles,
moist, loose to compact (black
and orange)
GLACIAL TILL:
Silty SAND and GRAVEL, trace
cobbles, moist to wet, compact
(olive brown)
BEDROCK:
Sedimentary bedrock, Siltstone,
very poor to poor quality, highly
fractured, rough joints, slightly
weathered, staining on joints (light
grey to dark grey)
BEDROCK:
Sedimentary bedrock, Mudstone,
weathered (dark grey)
BEDROCK:
Sedimentary bedrock, Siltstone,
poor to fair quality, highly
fractured in areas, rough joints,
slightly weathered, staining on
joints (light grey)
BEDROCK:
Sedimentary bedrock, Sandstone,
poor to fair quality, highly
fractured in areas, rough joints,
slightly weathered, staining on
joints (light grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor to good quality, highly
fractured in areas, rough joints
(alternating between light and
dark grey)
2.4
1.7
-2.1-2.2
-4.4
-5.3
381
0
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100%
100%
100%
100%
100%
90%
90%
100%
100%
5
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52
26
26
42
57
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RC
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RC
RC
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DESCRIPTION
SAMPLES
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20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
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t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
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RemouldedField Vane Test
N-
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Standard Penetration Test, blows/0.3mRE
C
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BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor to good quality, highly
fractured in areas, rough joints
(alternating between light and
dark grey) (continued)
-23.6
100%
100%
100%
100%
100%
100%
100%
100%
97
47
42
33
70
65
67
57
RC
RC
RC
RC
RC
RC
RC
RC
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DESCRIPTION
SAMPLES
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20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-10.8
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t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
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FILL (Reworked Till):
Sandy SILT, some gravel and
construction debris (concrete),
trace cobbles, moist, loose to
compact (dark brown to olive
brown)
GLACIAL TILL:
Silty SAND and GRAVEL, moist,
dense (reddish brown)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
very poor quality, highly
fractured, rough joints, slightly
weathered, staining on joint (light
grey to dark grey)
BEDROCK:
Sedimentary bedrock, Mudstone,
weathered (dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
very poor to poor quality, highly
fractured in areas, rough joints,
slightly weathered (light grey to
dark grey)
BEDROCK:
Sedimentary bedrock, Siltstone,
poor to fair quality, highly
fractured in areas, mudstone
infilling on fracture facing (light
grey)
BEDROCK:
Sedimentary bedrock, Sandstone,
fair quality, rough joints (light
grey)
BEDROCK:
3.6
3.0
-1.0-1.3
-3.1
-7.4
-10.4-10.7
406
508
100%
100%
100%
100%
100%
100%
100%
100%
100%
22
8, 8, 41
and 50
for 75
mm
0
0
0
22
35
63
57
58
65
SS
SS
RC
RC
RC
RC
RC
RC
RC
RC
RC
1
2
3
4
5
6
7
8
9
10
11
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
6.9
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#2
DATUMWATER LEVELDATES of BORING Jan 8, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
v
:
6
/
2
7
/
1
1
G
L
A
C
E
B
A
Y
S
I
T
E
.
G
P
J
D
A
TA
E
N
T
R
Y
.
G
D
T
2
/
1
/
1
9
P
r
i
n
t
e
d
b
y
:
B
u
f
f
e
t
t
J
RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
R
Y
mm
ST
R
A
T
A
P
L
O
T
TY
P
E
NU
M
B
E
R
WA
T
E
R
L
E
V
E
L
Sedimentary bedrock, Mudstone,
weathered (dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor to good quality, highly
fractured in areas, rough joints
(alternating between light and
dark grey) (continued)
BEDROCK:
Sedimentary bedrock, Sandstone,
good to poor quality, rough joints
(light grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor to good quality, highly
fractured in areas, rough joints,
slightly weathered (light grey to
dark grey)
-13.8
-19.0
-24.5
100%
100%
100%
100%
100%
100%
100%
100%
100%
62
58
83
87
85
47
33
68
82
RC
RC
RC
RC
RC
RC
RC
RC
RC
12
13
14
15
16
17
18
19
20
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-11.1
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#2
DATUMWATER LEVELDATES of BORING Jan 8, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
v
:
6
/
2
7
/
1
1
G
L
A
C
E
B
A
Y
S
I
T
E
.
G
P
J
D
A
TA
E
N
T
R
Y
.
G
D
T
2
/
1
/
1
9
P
r
i
n
t
e
d
b
y
:
B
u
f
f
e
t
t
J
RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
R
Y
mm
ST
R
A
T
A
P
L
O
T
TY
P
E
NU
M
B
E
R
WA
T
E
R
L
E
V
E
L
FILL (Reworked Till):
Silty SAND, trace to some gravel
and cobbles, trace organics, moist
to wet, loose to compact (black to
olive brown)
GLACIAL TILL:
Silty SAND and GRAVEL, moist,
(olive brown)
BEDROCK:
Sedimentary bedrock, Siltstone,
very poor quality, highly
fractured, rough joints, slightly
weathered, staining on joints (dark
grey)
BEDROCK:
Sedimentary bedeck, alternating
layers of siltstone and mudstone,
very poor to poor quality, highly
fractured and weathered in areas
(dark grey)
BEDROCK:
Sedimentary bedrock, Siltstone,
poor quality, highly fractured,
rough joints, slightly weathered,
staining on joints (dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor to good quality, highly
fractured in areas, rough joints,
slightly weathered (light grey to
dark grey)
3.73.4
1.2
-1.8
-5.8
-7.9
305
483
100%
100%
100%
100%
100%
100%
100%
100%
6
18
0
10
15
0
28
27
80
SS
SS
RC
RC
RC
RC
RC
RC
RC
RC
1
2
3
4
5
6
7
8
9
10
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
7.6
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#3
DATUMWATER LEVELDATES of BORING Jan 9, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
v
:
6
/
2
7
/
1
1
G
L
A
C
E
B
A
Y
S
I
T
E
.
G
P
J
D
A
TA
E
N
T
R
Y
.
G
D
T
2
/
1
/
1
9
P
r
i
n
t
e
d
b
y
:
B
u
f
f
e
t
t
J
RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
R
Y
mm
ST
R
A
T
A
P
L
O
T
TY
P
E
NU
M
B
E
R
WA
T
E
R
L
E
V
E
L
FILL:
Silty GRAVEL, trace sand and
cobbles, wet, compact (brown)
GLACIAL TILL:
Silty SAND and GRAVEL, trace
cobbles, moist, compact (grey)
RESIDUAL SOIL:
Silty GRAVEL and SAND (GM),
moist, dense (dark grey)
BEDROCK:
Sedimentary bedeck, alternating
layers of siltstone and sandstone,
very poor to good quality, highly
fractured and weathered in areas
(dark grey to light grey)
BEDROCK:
Sedimentary bedeck, Mudstone,
very poor to fair quality (dark
grey)
BEDROCK:
Sedimentary bedeck, alternating
layers of siltstone and sandstone,
very poor to good quality, highly
fractured and weathered in areas
(dark grey to light grey)
7.2
5.8
2.7
-2.9
-3.4
406
203
356
100%
85%
100%
100%
100%
100%
80%
100%
95%
11
27
48
0
9
15
0
47
13
52
75
35
SS
SS
SS
RC
RC
RC
RC
RC
RC
RC
RC
RC
1
2
3
4
5
6
7
8
9
10
11
12
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
10.5
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#4
DATUMWATER LEVELDATES of BORING Jan 10, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
v
:
6
/
2
7
/
1
1
G
L
A
C
E
B
A
Y
S
I
T
E
.
G
P
J
D
A
TA
E
N
T
R
Y
.
G
D
T
2
/
1
/
1
9
P
r
i
n
t
e
d
b
y
:
B
u
f
f
e
t
t
J
RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
R
Y
mm
ST
R
A
T
A
P
L
O
T
TY
P
E
NU
M
B
E
R
WA
T
E
R
L
E
V
E
L
BEDROCK:
Sedimentary bedeck, alternating
layers of siltstone and sandstone,
very poor to good quality, highly
fractured and weathered in areas
(dark grey to light grey)
(continued)
-20.2
100%
100%
100%
97%
100%
85%
100%
100%
90
72
53
62
82
100
40
60
RC
RC
RC
RC
RC
RC
RC
RC
13
14
15
16
17
18
19
20
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-7.5
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#4
DATUMWATER LEVELDATES of BORING Jan 10, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
v
:
6
/
2
7
/
1
1
G
L
A
C
E
B
A
Y
S
I
T
E
.
G
P
J
D
A
TA
E
N
T
R
Y
.
G
D
T
2
/
1
/
1
9
P
r
i
n
t
e
d
b
y
:
B
u
f
f
e
t
t
J
RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
R
Y
mm
ST
R
A
T
A
P
L
O
T
TY
P
E
NU
M
B
E
R
WA
T
E
R
L
E
V
E
L
FILL:
Sandy SILT and GRAVEL
(rounded), some construction
debris (asphalt and brick), trace
cobbles, moist, loose (black to
olive brown)
GLACIAL TILL:
Silty SAND and GRAVEL, trace
cobbles, moist, compact (dark
brown)
RESIDUAL SOIL:
Silty GRAVEL and SAND, moist,
dense (dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
very poor quality, highly
fractured in areas, rough joints,
staining on fracture faces
(alternating between light and
dark grey)
BEDROCK:
Sedimentary bedrock, Siltstone,
very poor quality, highly
fractured, rough joints, slightly
weathered, (dark grey)
BEDROCK:
Sedimentary bedrock, Mudstone,
completely weathered (dark grey)
BEDROCK:
Sedimentary bedrock, Siltstone,
poor to fair quality, rough joints,
staining on surface of fractures
(dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor quality, highly fractured in
areas, rough joints (alternating
between light and dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and
Mudstone, poor quality, highly
fractured in areas, rough joints
6.8
6.15.8
3.7
2.52.2
0.5
-0.9
-1.5
-5.4
150
406
95%
100%
100%
100%
100%
100%
100%
100%
6
52
0
20
13
58
32
38
55
40
SS
SS
RC
RC
RC
RC
RC
RC
RC
RC
1
2
3
4
5
6
7
8
9
10
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
10.1
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#5
DATUMWATER LEVELDATES of BORING Jan 11, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
v
:
6
/
2
7
/
1
1
G
L
A
C
E
B
A
Y
S
I
T
E
.
G
P
J
D
A
TA
E
N
T
R
Y
.
G
D
T
2
/
1
/
1
9
P
r
i
n
t
e
d
b
y
:
B
u
f
f
e
t
t
J
RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
R
Y
mm
ST
R
A
T
A
P
L
O
T
TY
P
E
NU
M
B
E
R
WA
T
E
R
L
E
V
E
L
(dark grey to black)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor to fair quality, highly
fractured in areas, rough joints
(alternating between light and
dark grey)
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-7.9
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#5
DATUMWATER LEVELDATES of BORING Jan 11, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
v
:
6
/
2
7
/
1
1
G
L
A
C
E
B
A
Y
S
I
T
E
.
G
P
J
D
A
TA
E
N
T
R
Y
.
G
D
T
2
/
1
/
1
9
P
r
i
n
t
e
d
b
y
:
B
u
f
f
e
t
t
J
RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
R
Y
mm
ST
R
A
T
A
P
L
O
T
TY
P
E
NU
M
B
E
R
WA
T
E
R
L
E
V
E
L
FILL:
Silty SAND and GRAVEL,
saturated, very loose (brown)
GLACIAL TILL:
Silty SAND (SM), trace gravel
and cobbles, moist to wet,
compact (olive brown)
RESIDUAL SOIL:
Silty GRAVEL and SAND, moist,
dense (dark grey)
BEDROCK:
Sedimentary bedrock, Sandstone,
very poor quality, highly
fractured in areas, rough joints,
staining on fracture faces
(alternating between light and
dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Mudstone and Siltstone,
poor quality, highly fractured in
areas, rough joints, weathered
(alternating between light and
dark grey)
BEDROCK:
Coal (black)
BEDROCK:
Sedimentary bedrock, Mudstone,
poor quality (dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor quality, highly fractured in
areas, rough joints (alternating
between light and dark grey)
BEDROCK:
Sedimentary bedrock, Siltstone,
very poor to fair quality, highly
fractured in areas, rough joints,
(alternating between light and
dark grey)
8.6
8.0
7.0
4.64.5
4.03.9
2.5
-3.6
152
406
100%
100%
100%
100%
100%
100%
100%
100%
3
24
0
23
8
40
22
23
70
28
SS
SS
RC
RC
RC
RC
RC
RC
RC
RC
1
2
3
4
5
6
7
8
9
10
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
11.9
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#6
DATUMWATER LEVELDATES of BORING Jan 12, 2019The new identity of ADI Limited
GE
O
T
E
C
H
N
I
C
A
L
L
O
G
R
e
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RemouldedField Vane Test
N-
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Standard Penetration Test, blows/0.3mRE
C
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mm
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Appendix C – Wastewater Treatment Plant Geotechnical Evaluation
Glace Bay Site
301 Alexandra Street, Sydney, NS B1S 2E8
t: 902.562.2394 f: 902.564.5660 www.exp.com
April 15, 2018 SYD-00245234-A0/60.2
Mr. Terry Boutilier
Dillon Consulting Limited
275 Charlotte Street
Sydney, NS B1P 1C6
Re: Wastewater Treatment Plant Geotechnical Evaluation
Glace Bay Site
Dear Mr. Boutilier:
1.0 Introduction
It is the pleasure of EXP Services Inc. (EXP) to provide Dillon Consulting Limited (Dillon) with this letter
regarding the risk of ground surface subsidence associated with historical mining activities within the
proposed construction area of the new wastewater treatment facility in Glace Bay, Nova Scotia. The
potential for future subsidence due to collapse in the mine working was assessed using historical mine
working plans obtained from the Nova Scotia Department of Natural Resources and from field data
obtained through the advancement of two boreholes down through the coal seam and/or abandoned
mine workings.
A review of historical mining records shows extensive mining activities have been carried out under the
proposed construction sites.
2.0 Subsidence Mechanisms
Coal mine subsidence is the downward movement of the earth’s surface caused by the collapsing/
failing of either the mine working’s roof and/or support pillars. The effect of the mine subsidence can
manifest itself on the ground surfaces in the form of holes, cracks, tilting and/or troughs. Many factors
contribute to the risk of subsidence in the ground surface due to historical mining activities. Some of
the more common factors include the depth of the mine workings, the geometry of the mine, how
much coal was extracted, the overlying geology and groundwater fluctuations. The two main
mechanisms of surface subsidence for this project are the caving of mining roofs and/or
crushing/collapse of pillars.
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Evaluation
Glace Bay Site
SYD-00245234-A0
April 15, 2019
2
\\trow.com\PROJECTS\SYD\SYD-00245234-A0\60 Project Execution\60.2 Reports\Subsidence Letter\Glace_Bay_Site - Subsidence Rev 1.docx
Caving of the mine working’s roof from room-and-pillar mining can show itself as trough subsidence
or ‘sinkholes’ in the ground surface. This type of surface subsidence is more of a concern for shallow
mine workings as opposed to deep mine workings due to the bulking characteristic of the mine roof
materials. When the roof collapses and the material accumulates in the mine void, the volume of space
occupied by the collapsed rubble is always greater than the volume occupied by that same rock prior
to collapse (10 to 30% bulking factor). Typically, caving height will be limited in advancement to
approximately 12 times the mining void height.
Crushing or collapsing of a singular pillar causes an increase in the overburden stress acting on adjacent
supporting pillars. The increase in stress to the adjacent pillars may exceed the strength of the pillars
and cause a chain reaction of pillar failures over a large area and encompassing all or parts of multiple
mine rooms. As such, the effects associated with ground surface subsidence can cover a footprint that
is hundreds of feet in width.
Roof collapse from short/long wall mining can possibly create trough subsidence on the ground surface
depending on the depth of the mine and the strata above the coal seam.
3.0 Site Location and Underground Mine Working
As previously reported, the proposed construction sites are located off of Lower North Street in Glace
Bay, Nova Scotia on two separate lots across the street from one another. The first site (Option 1) is
located on the eastern side of Lower North Street, within the footprint of Fisherman’s Park, and is
identified by Property Identification Number (PID) 15864085. A review of historical mining records
shows that mining activities (room-and-pillar) in the Phalen Seam have been completed under a small
portion of the site directly under the proposed location of the proposed wastewater treatment facility
(see Figure 1). The historical drawing also suggested that some of the support pillars, along the western
perimeter of the proposed water treatment building, may have been extracted.
The second site (Option 2) is located on a vacant lot on the western side of Lower North Street and is
identified by PIDs 15821119, 15395221, 15833007, 15654882 and 15393606. A review of historical
mining records for this subject area indicated that both the Phalen and Harbour Seams were mined
(room-and-pillar method) at some point and to varying degrees under this site. For the Phalen Seam,
the historical drawings suggest that the entire footprint of the subject site has been mined and that the
vast majority of support pillars have been extracted (see Figures 2 and 3). The historical drawing for the
Harbour Seam suggests that only a portion of the proposed site was mined at some point during the
operational life of the mine, but no pillar extraction was conducted in the subject area.
3.1 Phalen Mine Seam
Historical records indicated that the Phalen Seam ranges from 2.0 metres (6 feet 7 inches) to 2.18
metres (7 feet 2 inches) in thickness and is located approximately 175 metres (574 feet) below ground
surface at each site. These workings were initially of the standard room-and-pillar type mining. The
historical records also indicate that extensive pillar extraction was completed within the proposed
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Evaluation
Glace Bay Site
SYD-00245234-A0
April 15, 2019
3
\\trow.com\PROJECTS\SYD\SYD-00245234-A0\60 Project Execution\60.2 Reports\Subsidence Letter\Glace_Bay_Site - Subsidence Rev 1.docx
construction zone of Option 2. The calculated extraction ratio in the Phalen Seam below the site was
calculated to be 0.52; however, due to the removal of support pillars in the area the value should be
closer to 1.00. Neglecting the effect of the support pillar removal and assuming that the Phalen Seam
has been flooded to approximately sea level within the footprint of the proposed construction site, the
factor of safety for the Phalen Seam approximately ranges between 0.4 (Holland-Gaddy Formula) and
1.9 (Salamon-Munro Formula) well below the 2.0 recommended criteria. When the removal of the
support columns is taken into consideration, the factor of safety value drops significantly. As such, we
consider the risk of subsidence above this portion of the Phalen Seam to be:
• Low to Moderate for Option 1; and
• Moderate to High for Option 2.
It is our opinion that the Phalen Seam is relatively deep, and settlement of the surface would be small
and gradual.
3.2 Harbour Seam
Historical records indicate that the Harbour Seam has a thickness of 2.06 metres (6 feet 9 inches) and
was estimated to 30 to 50 metres (98 to 164 feet) below ground surface. The mine workings in this area
were of the standard room-and-pillar excavation method. As such, the extraction ratio in the Harbour
Seam below the site was calculated to be 0.60. Confirmatory boreholes (two) were installed by EXP in
March 2019 on Option 2 to verify the presence and/or absence of mine workings within the footprint
of the treatment facility. The first borehole (BH#6A) was an advancement of BH#6 to confirm the
presence of historical mine workings (voids and rubble) within the footprint of the facility at
approximately 50 metres (164 feet) below grade while the second borehole (BH#4A) was an
advancement of BH#4 to confirm the presence of a 3.1 metre (10.2 feet) thick coal seam at an elevation
similar to BH#6A. Assuming that water within the mine seam is approximately at sea level, and
incorporating the empirical data collected from the borehole program, the factor of safety for the
Harbour Seam approximately ranges between 1.3 (Holland-Gaddy Formula) and 4.1 (Salamon-Munro
Formula). As such, we consider the risk of subsidence associated with Harbour Mine seam to be:
• Low to moderate for Option 1 (as no historical records show any evidence that the Harbour
Seam has been previously mined); and
• Moderate to high for Option 2.
Although this information is positive, we caution that the stability calculations are based on parameters
that have a relatively high degree of uncertainty. Also, the location of mine activities documented are
subject to some horizontal and rotational variations.
4.0 Discussion and Recommendations
Based on the information obtained from the available mine working information and exploratory
boreholes completed, the factor of unacceptable subsidence associated with mine workings in the
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Evaluation
Glace Bay Site
SYD-00245234-A0
April 15, 2019
4
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Phalen and Harbour Seams are considered to be low to moderate for Option 1 and moderate to high
for Option 2.
To improve the confidence in Option 2 the following mitigations methods could be considered.
• Design the proposed structure to be able to withstand significant ground movements (a thick
concrete slab below the structure sitting on a layer of compacted sand).
• Support the facility on drilled steel pipe piles filled with concrete or piles socked into the mine
floor of the Harbour Seam.
• Form concrete pillars in historical mine workings (Harbour Seam) on a grid system below the
facility.
• Fill the mine cavity (Harbour Seam) below the site with granular materials.
Based on the knowledge that Option 2 appears to have a footprint that has some amount of mine
activity from the Harbour Seam under the west portion of the proposed facility, the placement of
granular material to fill the mine cavity could possibly introduce differential settlement if the pillars
failed. It is for this reason that we recommend any of the other three mitigation methods be considered
for this project to address the issue of the possible failure of the pillars in the Harbour Seam.
If Option 2 could be re-orientated on the Option 2 site it may also lessen the potential to be positioned
over the Harbour Seam mine workings. Any re-orientation should follow with additional drilling to
investigate for mine workings.
5.0 Conclusion
Although the preliminary recommendations for mitigations in this letter will not eliminate the
possibility of settlement of the ground surface below the new structure, it is intended that these steps
would result in movements within tolerable limits.
This letter report is prepared for the Glace Bay site. Should you have any questions or concerns, please
contact John Buffett or Gary Landry at 902.562.2394.
Sincerely, Sincerely,
John Buffett, P.Eng., B.Sc., RSO Gary Landry, P.Eng., B.Sc.
Project Engineer Project Manager
EXP Services Inc.
Attachments
POLE
EXIST.
BUILDING
(BAYPLEX)
GLACE BAY
HARBOUR
MAIN ST.
CAMERON'S
BLDG.
SUPPLIES
ATLANTIC
OCEANOPTION 2
OPTION 1
LO
W
E
R
N
O
R
T
H
S
T
.
B
E
A
C
H
S
T
.
FISH
PLANT
FISH
PLANT
BH1
7.224
N5118741.483
E24619582.358
BH2
6.937
N5118794.313
E24619596.540
BH3
7.624
N5118781.507
E24619548.494
BH4/BH4A
10.469
N5118887.202
E24619504.232
BH6/BH6A
11.921
N5118903.004
E24619461.970
BH5
10.101
N5118837.635
E24619480.459
Project Title Dwg. Title:
c 2018
Project No.
Dwg. No.Rev. No.
Drawn By:
Dwg Standards
Ckd By:
www.exp.com
BUILDINGS · EARTH & ENVIRONMENT · ENERGY · INDUSTRIAL · INFRASTRUCTURE · SUSTAINABILITY
EXP
EXP. Services Inc.
Design Checked
By:
Designed By:
11
Services Inc.
7 WATER TREATMENT PLANTS
STUDY GEOTECHNICAL
DESKTOP STUDY
WWTP BUILDING
(OPTIONS 1 & 2)
4/
1
5
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FOR INFORMATION ONLY
NB
JB
GL
SYD-00245234-A0
Fig1 0
t: +1.902.562.2394 | f: +1.902.564.5660
301 Alexandra St.,
Sydney, NS B1S 2E8
CANADA NB
SCALE: 1:2500
POLE
SB
R
WTP
B
L
D
G
.
S
B
R
SB
R
SB
R
S
B
R
S
B
R
SMFDSMFDSMFD
■■
■
X
X
EXIST.
BUILDING
(BAYPLEX)
EXIST. FENCED
AREA (MINE
VENT)
EXIST. FENCED
AREA (MINE
VENT)
BH1
7.224
N5118741.483
E24619582.358
BH2
6.937
N5118794.313
E24619596.540
BH3
7.624
N5118781.507
E24619548.494
BH4/BH4A
10.469
N5118887.202
E24619504.232
BH6/BH6A
11.921
N5118903.004
E24619461.970
BH5
10.101
N5118837.635
E24619480.459
GLACE BAY
HARBOUR
MAIN ST.
CAMERON'S
BLDG.
SUPPLIES
ATLANTIC
OCEAN
OPTION 2
OPTION 1
LO
W
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FISH
PLANT
FISH
PLANT
Project Title Dwg. Title:
c 2018
Project No.
Dwg. No.Rev. No.
Drawn By:
Dwg Standards
Ckd By:
www.exp.com
BUILDINGS · EARTH & ENVIRONMENT · ENERGY · INDUSTRIAL · INFRASTRUCTURE · SUSTAINABILITY
EXP
EXP. Services Inc.
Design Checked
By:
Designed By:
11
Services Inc.
7 WATER TREATMENT PLANTS
STUDY GEOTECHNICAL
DESKTOP STUDY
GLACE BAY
BOREHOLE LOCATIONS &
DOMINION No.2 PHALEN MINE
HISTORIC WORKINGS
4/
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FOR INFORMATION ONLY
NB
JB
GL
SYD-00245234-A0
Fig2 0
t: +1.902.562.2394 | f: +1.902.564.5660
301 Alexandra St.,
Sydney, NS B1S 2E8
CANADA NB
SCALE: 1:2000
NOTE:
COORDINATES SHOWN ARE IN REFERENCE
TO THE NAD83 (CSRS 2010) SYSTEM
POLE
SB
R
WTP
B
L
D
G
.
S
B
R
SB
R
SB
R
S
B
R
S
B
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■■
■
X
X
EXIST.
BUILDING
(BAYPLEX)
EXIST. FENCED
AREA (MINE
VENT)
EXIST. FENCED
AREA (MINE
VENT)
GLACE BAY
HARBOUR
MAIN ST.
CAMERON'S
BLDG.
SUPPLIES
ATLANTIC
OCEAN
OPTION 2
OPTION 1
LO
W
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N
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H
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.
B
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H
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WTP B
L
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.
FISH
PLANT
FISH
PLANT
BH1
7.224
N5118741.483
E24619582.358
BH2
6.937
N5118794.313
E24619596.540
BH3
7.624
N5118781.507
E24619548.494
BH4/BH4A
10.469
N5118887.202
E24619504.232
BH6/BH6A
11.921
N5118903.004
E24619461.970
BH5
10.101
N5118837.635
E24619480.459
Project Title Dwg. Title:
c 2018
Project No.
Dwg. No.Rev. No.
Drawn By:
Dwg Standards
Ckd By:
www.exp.com
BUILDINGS · EARTH & ENVIRONMENT · ENERGY · INDUSTRIAL · INFRASTRUCTURE · SUSTAINABILITY
EXP
EXP. Services Inc.
Design Checked
By:
Designed By:
11
Services Inc.
7 WATER TREATMENT PLANTS
STUDY GEOTECHNICAL
DESKTOP STUDY
GLACE BAY
BOREHOLE LOCATIONS &
DOMINION No.4 PHALEN MINE
HISTORIC WORKINGS
4/
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FOR INFORMATION ONLY
NB
JB
GL
SYD-00245234-A0
Fig3 0
t: +1.902.562.2394 | f: +1.902.564.5660
301 Alexandra St.,
Sydney, NS B1S 2E8
CANADA NB
SCALE: 1:2000
NOTE:
COORDINATES SHOWN ARE IN REFERENCE
TO THE NAD83 (CSRS 2010) SYSTEM
FILL:
Silty GRAVEL, trace sand and
cobbles, wet, compact (brown)
GLACIAL TILL:
Silty SAND and GRAVEL, trace
cobbles, moist, compact (grey)
RESIDUAL SOIL:
Silty GRAVEL and SAND (GM),
moist, dense (dark grey)
BEDROCK:
Sedimentary bedeck, alternating
layers of siltstone and sandstone,
very poor to good quality, highly
fractured and weathered in areas
(dark grey to light grey)
BEDROCK:
Sedimentary bedeck, Mudstone,
very poor to fair quality (dark
grey)
BEDROCK:
Sedimentary bedeck, alternating
layers of siltstone and sandstone,
very poor to good quality, highly
fractured and weathered in areas
(dark grey to light grey)
7.2
5.8
2.7
-2.9
-3.4
DESCRIPTION
SAMPLES
OT
H
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TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
10.5
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
0
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PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#4A
DATUMWATER LEVELDATES of BORING Mar 22, 2019The new identity of ADI Limited
GE
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RemouldedField Vane Test
N-
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Standard Penetration Test, blows/0.3mRE
C
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BEDROCK:
Sedimentary bedeck, alternating
layers of siltstone and sandstone,
very poor to good quality, highly
fractured and weathered in areas
(dark grey to light grey)
(continued)
BEDROCK:
Sedimentary, sandstone (medium
to fine grain), horizontal fractures
(5 to 15 degrees), fair to good,
grey
-thin mudstone seam (>1mm)
infilling fracture facing at 32.3 m.
BEDROCK:
Sedimentary, conglomerate
(medium grain sand), excellent
quality, grey to dark grey
BEDROCK:
Sedimentary, sandstone (medium
to fine grain), horizontal fractures
(5 to 15 degrees), excellent , grey
BEDROCK:
Sedimentary, conglomerate
(medium grain sand), excellent
quality, grey to dark grey
BEDROCK:
Sedimentary, alternating layer of
sandstone (fine grain) to siltstone,
-20.2
-23.2
-23.6-23.7
-24.6
-25.0
-25.8
-28.8
71%
95%
95%
92%
99%
98%
61
91
97
84
50
83
RC
RC
RC
RC
RC
RC
1
2
3
4
5
6
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-9.5
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#4A
DATUMWATER LEVELDATES of BORING Mar 22, 2019The new identity of ADI Limited
GE
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RemouldedField Vane Test
N-
V
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OR
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Standard Penetration Test, blows/0.3mRE
C
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mm
ST
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horizontal fractures (5 to 10
degrees), excellent to good, grey
BEDROCK:
Sedimentary, mudstone and
siltstone, weathered, grey
BEDROCK:
Sedimentary, alternating layers of
sandstone (medium to fine grain)
and siltstone, poor to good quality,
horizontal fractures (5 to 15
degrees), light to dark grey
BEDROCK:
Sedimentary, sandstone (fine to
medium grain), horizontal
fractures (5 to 10 degrees), good
quality, grey (continued)
BEDROCK:
Sedimentary, alternating layers of
sandstone (fine to medium grain),
shale and siltstone, horizontal
fractures, good to excellent
quality, light to dark grey
-one 45 degree fracture at 44.1
meters below grade
BEDROCK:
Sedimentary, sandstone (fine to
medium grain), horizontal
fractures (0 to 10 degrees), good
to excellent, grey to dark grey
BEDROCK:
Sedimentary, alternating siltstone
and shale, excellent quality, dark
grey
BEDROCK:
Sedimentary, sandstone (fine to
medium grain), horizontal
fracture, grey
BEDROCK:
(Harbour Seam) Coal, black
BEDROCK:
Sedimentary, sandstone (fine to
medium grain), dark grey
BEDROCK:
(Harbour Seam) Coal, black
BEDROCK:
Sedimentary, mudstone, dark grey
BEDROCK:
-31.9
-34.9
-37.6
-38.0
-39.5
-41.3-41.5
-42.6-42.7-42.8
100%
99%
96%
97%
100%
95%
100%
100%
95%
88
80
90
98
83
94
87
0
40
RC
RC
RC
RC
RC
RC
RC
RC
RC
7
8
9
10
11
12
13
14
15
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-29.5
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
EL
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.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#4A
DATUMWATER LEVELDATES of BORING Mar 22, 2019The new identity of ADI Limited
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RemouldedField Vane Test
N-
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Standard Penetration Test, blows/0.3mRE
C
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mm
ST
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Sedimentary, sandstone, grey
DESCRIPTION
SAMPLES
OT
H
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TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-49.5
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
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m
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PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#4A
DATUMWATER LEVELDATES of BORING Mar 22, 2019The new identity of ADI Limited
GE
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RemouldedField Vane Test
N-
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Standard Penetration Test, blows/0.3mRE
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mm
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FILL:
Silty SAND and GRAVEL,
saturated, very loose (brown)
GLACIAL TILL:
Silty SAND (SM), trace gravel
and cobbles, moist to wet,
compact (olive brown)
RESIDUAL SOIL:
Silty GRAVEL and SAND, moist,
dense (dark grey)
BEDROCK:
Sedimentary bedrock, Sandstone,
very poor quality, highly
fractured in areas, rough joints,
staining on fracture faces
(alternating between light and
dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Mudstone and Siltstone,
poor quality, highly fractured in
areas, rough joints, weathered
(alternating between light and
dark grey)
BEDROCK:
Coal (black)
BEDROCK:
Sedimentary bedrock, Mudstone,
poor quality (dark grey)
BEDROCK:
Sedimentary bedrock, alternating
layers of Sandstone and Siltstone,
poor quality, highly fractured in
areas, rough joints (alternating
between light and dark grey)
BEDROCK:
Sedimentary bedrock, Siltstone,
very poor to fair quality, highly
fractured in areas, rough joints,
(alternating between light and
dark grey)
8.6
8.0
7.0
4.64.54.03.9
2.5
-3.6
100%
88%
95%
90
54
95
RC
RC
RC
1
2
3
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
11.9
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
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m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#6A
DATUMWATER LEVELDATES of BORING Mar 22, 2019The new identity of ADI Limited
GE
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RemouldedField Vane Test
N-
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Standard Penetration Test, blows/0.3mRE
C
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mm
ST
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BEDROCK:
Sedimentary, alternating layers of
sandstone (fine grain) to siltstone,
excellent to good quality,
horizontal fractures (5 to 15
degrees), grey
Loss of water at 20.1 meters -
Verticle fracture at 20.1 meters
(continued)
BEDROCK:
Sedimentary, mixture of mudstone
and siltstone, highly fractured,
poor quality, grey
BEDROCK:
Sedimentary, alternating layers of
siltstone and sandstone (fine
grain), horizontal fractures, poor
to good quality, grey - thin seam
of mudstone on fracture facing
BEDROCK:
Sedimentary, alternating layer of
siltstone and mudstone, highly
fractured, grey
BEDROCK:
Sedimentary, sandstone, highly
fractured, fair to poor quality, grey
-one 45 degree fracture at 27.4
meters
BEDROCK:
Sedimentary, mudstone, highly
weathered, grey
BEDROCK:
Sedimentary, alternating layers of
sandstone (fine to medium grain)
and siltstone, horizontal fractures
(5 to 15 degrees), poor to good
quality, grey - 45 degree fracture
at 30.8 meters
BEDROCK: Sedimentary,
sandstone (fine to medium grain),
horizontal fractures, good to fair
quality, grey
BEDROCK: Sedimentary,
alternating layers of sandstone
(fine grain) and shale, horizontal
fractures (5 to 20 degrees), fair to
good quality, grey to dark grey -
-10.2
-12.4
-14.1-14.4
-15.7-15.8
-20.1
-22.7
-23.2
-25.9
100%
70%
76%
91%
92%
95%
83%
78%
93%
89%
91%
100%
78%
100%
100%
86
81
27
31
78
73
33
89
68
77
80
73
80
93
74
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-8.1
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#6A
DATUMWATER LEVELDATES of BORING Mar 22, 2019The new identity of ADI Limited
GE
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RemouldedField Vane Test
N-
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A
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Standard Penetration Test, blows/0.3mRE
C
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mm
ST
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vertical fracture 35.9 meters
BEDROCK: Sedimentary,
alternating layers of siltstone and
sandstone (fine grain), horizontal
fractures (5 to 15 degrees), grey
-thin seams of mud of some
fracture faces
BEDROCK: Sedimentary,
mudstone, dark grey (continued)
BEDROCK: Sedimentary,
alternating layers of sandstone
(fine to medium grain) to siltstone,
fair to good quality, horizontal
fractures, grey -45 degree
fractures at 43.3, 44.1 and 45.4
meters
BEDROCK: Sedimentary,
alternating sandstone (fine grain)
to shale, horizontal fractures (5 to
15 degrees), fair quality, grey
BEDROCK: Sedimentary,
sandstone (fine grain), fair quality,
horizontal fractures, grey
VOID
CAVE-IN / rubble (mudstone and
shale)
VOID
CAVE-IN / rubble (shale and
coal)
VOID
CAVE-IN / rubble (mudstone and
shale)
BEDROCK:
Sedimentary, mudstone to
sandstone (fine to medium grain),
horizontal fractures, grey
-30.4
-34.8
-36.3
-38.5
-39.3
-39.9-40.2
-40.6-40.9
-42.3
-44.5
98%
100%
92%
92%
71%
100%
100%
45%
52%
5%
89%
67%
47
69
63
93
87
59
54
0
0
0
0
55
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
19
20
21
22
23
24
25
26
27
28
29
30
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
-28.1
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002
Halifax, NS, B3L 2C2
Canada
http://www.exp.com
LOCATION Lower North Street, Glace Bay
CLIENT Dillon Consulting Ltd.
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
EL
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.
(
m
)
PROJECT No.SYD-00245234-A0
BOREHOLE No.BH#6A
DATUMWATER LEVELDATES of BORING Mar 22, 2019The new identity of ADI Limited
GE
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RemouldedField Vane Test
N-
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Standard Penetration Test, blows/0.3mRE
C
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mm
ST
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Appendix D – Rock Mechanics Investigation Proposed Wastewater
Treatment Plants, Glace Bay, Nova Scotia
885 Regent Street | Sudbury, Ontario, P3E 5M4 | Canada
t: +1.705.674.9681 | f: +1.705.674.5583 | exp.com
Rock Mechanics Investigation
Proposed Waste Water Treatment Plants Glace
Bay, Nova Scotia
Dillon Consulting Limited
Type of Document:
Final, Revision 1
Project Name:
Rock Mechanics investigation, WWTP Facility
Glace Bay, Nova Scotia
Project Number:
SYD-00245234-A0
Prepared By:
Gregory Hunt, M. Eng., P.Eng.
Senior Rock Engineer, Earth and Environmental, Northeastern Ontario
EXP Services Inc.
885 Regent Street
Sudbury, Ontario, P3E 5M4
Tel. 1.705.674.9681
Fax. 1.705.674.5583
Date Submitted:
2019-10-02 (Revised 2020-01-29)
Dillon Consulting Limited
Rock Mechanics Investigation
SYD-00245234-A0
i
Revised: 2020-01-29
Table of Contents
1. Background ................................................................................................................................... 1
2. Project Understanding ................................................................................................................... 1
3. Field Work ..................................................................................................................................... 2
4. Rock-Mass Assessment .................................................................................................................. 2
5. Failure Mechanisms ....................................................................................................................... 3
6. Subsidence Analysis ....................................................................................................................... 3
7. Foundation Discussions .................................................................................................................. 4
Appendix A: Site Plan, Borehole Records, Photographs and UCS
Dillon Consulting Limited
Rock Mechanics Investigation
SYD-00245234-A0
1
885 Regent Street | Sudbury, Ontario, P3E 5M4 | Canada
t: +1.705.674.9681 | f: +1.705.674.5583 | exp.com
1. Background
A new waste water treatment plant (WWTP) is being considered in Glace Bay, Nova Scotia together with a new
sewage lift station as indicated on the attached site plan, SK-1C REV. 2. Both locations are close to the ocean
shoreline along Lower North Street in an area where underground coal mining was historically undertaken. EXP
Services Inc. (EXP) has previously carried out a geotechnical investigation at both sites (initially labelled sites Option
1 and 2, respectively) to determine the existing subsoil conditions (EXP’s Geotechnical Investigation – WWTP Glace
Bay Sites, May 2019). As part of this initial investigation a supplementary preliminary assessment of the
underground mine workings was undertaken to address the potential of settlement under the proposed WWTP
(site – Option2), including the potential for ground subsidence resulting from the collapse of the bedrock above the
mined-out portions of the coal seam.
The findings of the supplementary assessment, titled: Wastewater Treatment Plant Geotechnical Evaluation Glace
Bay Site, was that there was a low to moderate risk of subsidence at the site labelled Option 1 and a moderate to
high risk of subsidence at the site called Option 2, which is due to the proximity of known worked coal seam areas
in the Harbour Seam (that was mined closer to surface). The basis of this latter conclusion was upon the
assessment of pillar strength in the mined-out areas that suggested a range of possible pillar Factor of Safety that
increased uncertainty.
The factor of safety for pillar design is defined as the strength of the pillar divided by the pillar load.
𝐹𝑎𝑐𝑡𝑜𝑟 𝑜𝑒 𝑆𝑎𝑒𝑒𝑡𝑦=𝑆𝑝
σ𝑝
Where Sp is the pillar strength and σp is the pillar load. Pillar strength is a function of both its size and shape. Pillar
strength increases when the pillar width increases and/or pillar height decreases. The pillar load (σp) is attributed to
the stress associated with supporting the tributary area of the overburden.
It was, however, recommended that additional testing of the bedrock be undertaken using four new diamond
drilled boreholes to assist with the determination of the strength of the rock mass between the coal seam and
surface. The resulting Rock Mechanics Investigation has now been completed at both sites and this report presents
the findings and recommendations of our Rock Mechanics Investigation.
2. Project Understanding
It is understood the new WWTP will involve sequencing batch reactors, SBR technology, that requires continuous,
reinforced concrete slab foundations. The designer, Harbour Engineering, joint-venture, has indicated that the
slabs and associated facility footings will be constructed at about elevation 4.5m (on engineered fill described in
the geotechnical report), which favours the site Option 2 as the preferred location. The point about the type of
structure, its foundation and length, is important considering the amount of induced strain that can result from the
gradual convergence of mined coal seams. There are, furthermore, other mechanisms of failure to consider, and
the conditions influencing these failure mechanisms are dependent on the geometry, strength and depth of the
coal seam, as well as the strength characteristics of the overlying rock. This report addresses the various factors
involved, and the rock mass rating, Rock Mass Rating (RMR), and geological strength index (GSI), of the bedrock
between the coal seam and the proposed foundation locations.
Dillon Consulting Limited
Rock Mechanics Investigation
SYD-00245234-A0
2
Revised: 2020-01-29
The mining records and available mine plans were searched out and reviewed by our Sydney geotechnical group
and discussed in the Wastewater Treatment Plant Geotechnical Evaluation letter report, dated May 10, 2019,
specifically identifying that the Dominion No. 2 Colliery workings on the Phalen Seam underly both locations at a
depth of approximately 175 m, and the Harbour Seam underlies Options 1 and 2 locations at depths ranging from
30 to 50m. On the Harbour Seam mine workings associated with the Sterling Mine and Harbour Pit worked this
area, but the exact extent is unknown.
As part of our current Rock Mechanics Investigation, we reviewed various sources of mining record documentation,
including Provincial and Federal sources, such as the Nova Scotia Abandoned Mine Openings Database; Guidelines
on Abandoned Coal Mines for Municipalities in Nova Scotia; NSDNR, Geological Map of Nova Scotia, Map 2000-1;
journal reports on recent subsidence events, including in Glace Bay, and various other records as pertain to the
long history of coal mining in Nova Scotia. Specific mine closure plans for most historical coal operations have not
been found and there are no accurate mine plans for the Phalen or Harbour Mine s upon which reliable ground
stability designs can be offered. The coal seams are typically flat, dipping about 2-4 degrees easterly, mined with
room and pillar/post pillar techniques. Rockfalls from the roof of the seams were common occurrences as opposed
to gradual convergence leading to seam closure. The mines have not been worked for many years and the coal
seams are presumed to be flooding with sea water.
Geological data confirms the bedrock description is of the Morien Group, Sydney Mines formation, weathered
sequences of weak fluvial and lacustrine mudstone and shale, and medium strength siltstone, sandstone/
limestone, coal. The coal seams are typically 2m to 3.5m thick, good quality, high volatile, B&A grade bituminous
and metallurgical types. The presence of calcites, halides and other erodible rock is apparently negligible but the
influence of groundwater on processes of gasification and erosion of the coal is not well documented.
3. Field Work
EXP completed the field work for the Rock Mechanics Investigation August 15, 2019 and the rock core samples
were brought to our laboratory in Sydney, Nova Scotia for examination and compre ssive strength testing. The field
work was comprised of advancing four vertical NQ diamond drill borehole to a depth of 60m. The location of the
boreholes, denoted RMS1-4, are shown on the attached site Drawing Number SK-1C, revision 2. Borehole core logs
have been prepared by our Sydney geotechnical group and are attached in Appendix A below as Borehole Records,
RMS 1 through RMS 4. Photographs of the core advanced for the Rock Mechanics Investigation are included with
the borehole records.
Laboratory testing on select core specimens, consisting of Uniaxial Compressive Strength tests, Appendix A, were
undertaken for assessment of the RMR and GSI determinations used to describe the bedrock and determine rock-
mass classification and overall stability.
4. Rock-Mass Assessment
The rock-mass encountered in our rock mechanic boreholes, RMS 1-4, is overlain at surface by approximately 4m to
6m of sand gravel, sorted moist brown fill and silt, sand gravel till. The bedrock is described as alternating grey
siltstone, sandstone. Overall the bedrock is comprised essentially of bedded siltstone with shale. Uniaxial
compressive strength tests for rock units of these alternating sequences range from 35MPa to 126MPa for NQ size
core. The average rock mass strength is about 55MPa to 60MPa. Previously, two boreholes were advance d using
HQ size core that suggests weaker rock, typically 35MPa to 40MPa. The coal has a unconfined compressive strength
Dillon Consulting Limited
Rock Mechanics Investigation
SYD-00245234-A0
3
Revised: 2020-01-29
(UCS) value of 11MPa and the seam is firm to hard, bedded with stress induced fractures. The bulking factor for
coal is estimated to be about 20%.
The jointing characteristics of the siltstone is dominated by horizontal bedding; a flat, fluvial bedding pattern with
shale interbedding with random alterations. This suggest assigning two bedding joint sets as part of the joint
number assessment. Two other primary cross joints are observed (40-60 degrees), and lesser vertical fracturing.
The joint set number is estimated to be 4. Jointing is tightly spaced, with alterations including smooth to rough,
mud filled joints. The rock quality designation (RQD) is predominately in the range of 30% to 80% and is considered
fair to good quality. The classic NGI tunnelling value Q = 10, fair to good rating, is a reasonable estimate for the
rock mass based on the four boreholes recently advanced.
Developments in rock mechanics by various experts have led to a better understanding of rock mass
characterization and behaviour. This work involves the determination of the rock mass ratin g RMR for bedrock and
we have calculated a value of 40 for this parameter. And correspondingly, we estimate the value of the GSI to be
30, which is lower than the corresponding RMR. The lower compressive strength values reported for BH6A,
however, reduces the GSI to about 11. Based on boreholes RMS 1-4, the GSI value 30 will be selected for the
stability assessment of the rock mass lying above both Option 1 and Option 2 sites, this is in the poor to fair range.
For the purpose of understanding the behaviour of the bedrock that lies above the shallow Harbour coal seam, we
have determined the failure criteria parameters “m” and “s” as defined in the generalized Hoek and Brown
relationship. The corresponding values of m = 0.38 and s = 0.009, UCS = 60MPa.
Based on similar rock type date, we inferred the siltstone has a deformation modulus E = 3.0GPa and unit weight
2.60t/m3. The principal stress acting on the Harbour mine coal seam is likely horizontal and about 4.0MPa. Vertical
stress is less and about 1.5MPa.
5. Failure Mechanisms
The failure mechanisms for surface subsidence resulting from mining are complex. The traditional consideration is
that three geometries of failure patterns commonly develop from near surface coal mining. A relatively large
regional rectangular failure pattern, that can also apply to more isolated column type failures. A wedge failure that
involves adverse jointing, or structural failure. And conical failures involving break and cave angles respectively that
are relatively steep.
Coal seams usually fail gradually by convergence and depending on the thickness of the coal, open spans and
nature and thickness of cover rock, it can take considerable time before subsidence at surface occurs, if any. Most
situations are described by determining the extent of the cave zone, fracture zone and bending zone in the
overlying bedrock. Long-term settlement predictions of building structures above a coal seam have been
reasonably predicted using empirical methods and these methods will be discussed below. Recent methods
involving advanced numerical models and programing such as Phase 2 requires proper modelling of the mine plans,
which do not exist for this project.
6. Subsidence Analysis
In regards, to the coal seams lying approximately 175m below surface, the Phalen Mine, influencing both sites
Option 1 and 2, and indeed the entire area, the impact on surface structures is negligible based on the reported
Dillon Consulting Limited
Rock Mechanics Investigation
SYD-00245234-A0
4
Revised: 2020-01-29
average coal seam thickness of 3.0m and empirical relationships developed National Coal Board of Great Britain
NCB, 1975 which suggests rock mass strain to a maximum height above the mined out seam should be less than
2mm at about 90m above the seams. This also implies that the problem of multiple seam situations such as where
the Harbour Mine is above the Phalen Mine is not significant and we can focus on the issue of the Harbour Mine
separately.
The potential for subsidence at the proposed Lift station site Option 1 (south side of street) is therefore very low
and our boreholes RMS 3 and RMS 4 did not encounter mine voids and confirmed intact coal is present.
Our assessment for the Harbour Mine conditions underlying the current WWTP site is based on the British NCB
Method, and this method suggests that for a room size approximating 6m by 50m with the voids or seam thickness
encountered at both RMS 2 and BH6A, that up to 50mm to 75mm of settlement could occur at this site over time.
Factors affecting the rheology of the rock, that is the time related aspects, are not known but settlement of this
nature occurs typically within 50 years of mining. It is our understanding that this amount of settlement has not
been observed at this location and therefore the NCB method of analysis may be too conservative for the Glace Bay
coal mining region. Of interest is the fact that more than 50 to 75 mm of settlement has occurred as recently as 7
years ago on Main Street (Harbour Seam workings), which is approximately 116 years after the mine in this area
closed.
We have also considered the crown pillar aspect of a room and pillar configuration using the Scaled Span Method,
Carter T. G., 2000. This method uses the above RMR/GSI values and is widely accepted and includes a large range of
crown pillar data. It does not specifically have coal mine applications but in recent work Carter has used it for
shallow dipping orebodies including coal. With the Harbour Mine case, a critical span value of Cs = 1.9 has been
determined and when using the RMR value of 40, the probability of rock-mass failure is less than 0.5%. Therefore,
our Rock Mechanics Investigation suggests the subsidence potential is low at this location.
7. Foundation Discussions
It is understood the proposed foundation type is engineered slab and strip footings on structural fill at both locations.
It is our recommendation that the structural slabs at the new WWTP be designed with a potential differential
settlement of 75mm in consideration of the low potential of settlement rating due to subsidence. The slab and
footing foundations for the proposed lift station can be designed with of 25mm differential settlement given the very
low potential of settlement rating at this location.
It is recognized that existing structures near the proposed WWTP facility locations, such as the nearby Bayplex
Building and other structures in the area, have not experienced settlement due to subsidence but there have been
situations in Glace Bay generally where unexpected sink holes have formed due possibly to mine access shafts and
raises that were not properly sealed. The precautionary design to a larger predicted settlement value at the WWTP
is a conservative approach; however, our analysis, has not considered the issue of seismic design nor the issue of
unknown mine workings that may for example result in problematic settlement which has historically been occurring
in the Glace Bay area over the years and most recently as in August, 2019.
8. Closure
We thank you for the opportunity to submit this report and should you have any questions concerning the above,
please do not hesitate to contact the undersigned directly.
Dillon Consulting Limited
Rock Mechanics Investigation
SYD-00245234-A0
6
Revised: 2020-01-29
Yours truly,
EXP Services Inc.
Gregory Hunt, P. Eng.
Senior Rock Mechanics Engineer,
Sudbury, Ontario
Gary Landry, P. Eng.
Project Manager,
Sydney, Nova Scotia
Yves Beauparlant, P.Eng.
Manager of Earth and Environmental Services,
Sudbury, Ontario
Dillon Consulting Limited
Rock Mechanics Investigation
SYD-00245234-A0
6
Revised: 2020-01-29
Appendix A: Site Plan, Borehole Records, Photographs and UCS
Site Plan
POLE
BH1
7.224
N5118741.483
E24619582.358
BH2
6.937
N5118794.313
E24619596.540
BH3
7.624
N5118781.507
E24619548.494
BH4/4A
10.469
N5118887.202
E24619504.232
BH6/6A
11.921
N5118903.004
E24619461.970
BH5
10.101
N5118837.635
E24619480.459
RMS#1
RMS3
6.792
N5118795.411
E24619595.809
RMS1
10.987
N5118868.613
E24619449.001
RMS2
11.288
N5118925.422
E24619430.479
RMS4
7.616
N5118752.592
E24619573.068
Project Title Dwg. Title:
c 2018
Project No.
Dwg. No.Rev. No.
Drawn By:
Dwg Standards
Ckd By:
www.exp.com
BUILDINGS · EARTH & ENVIRONMENT · ENERGY · INDUSTRIAL · INFRASTRUCTURE · SUSTAINABILITY
EXP
EXP. Services Inc.
Design Checked
By:
Designed By:
11
Services Inc.
7 WATER TREATMENT PLANTS
STUDY GEOTECHNICAL
DESKTOP STUDY
GLACE BAY
PROPOSED LOCATIONS
FOR BOREHOLES
ASSOCIATED WITH ROCK
MECHANICS STUDY
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FOR INFORMATION ONLY
NB
JB
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SYD-00245234-A0
SK-1C 2
t: +1.902.562.2394 | f: +1.902.564.5660
301 Alexandra St.,
Sydney, NS B1S 2E8
CANADA NB
SCALE: 1:1500
NOTE:
1.COORDINATES SHOWN ARE IN
REFERENCE TO THE NAD83
(CSRS 2010) SYSTEM
Borehole Records
FILL:SAND and GRAVEL, someconstruction debris (asphalt andbrick), trace cobbles, moist,compact (black to olive brown)
RESIDUAL SOIL:Silty GRAVEL and SAND, moist,
dense (dark grey)
SEDIMENTARY BEDROCK:Alternaitng layers of siltstone,
sandstone (fine/medium grain),mudstone
COAL
SEDIMENTARY BEDROCK:Siltstone, horizontal fractures, greyto black
COAL
SEDIMENTARY BEDROCK:
Alternating layer of siltstone andsandstone, horizontal fractures,
175
75%
100%
97%
100%
100%
100%
97%
100%
100%
98%
100%
100%
100%
100%
97%
90%
98%
101%
100%
100%
100%
100%
100%
100%
100%
102%
100%
100%
97%
97%
95%
88%
100%
16
27
44
14
68
49
91
46
66
53
86
97
59
68
44
38
72
40
95
54
49
24
82
85
89
84
42
66
84
77
7
29
71
SS
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
1
2
3
4
5
6
7
8
9
10
11
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13
14
15
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19
20
21
22
23
24
25
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28
29
30
31
32
33
34
DESCRIPTION
SAMPLES
OT
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S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002Halifax, NS, B3L 2C2
Canadahttp://www.exp.com
LOCATION Glace Bay, NS
CLIENT Dillon Consulting Limited
0123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960
EL
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(
m
)
PROJECT No.SYD-00245234-A0
TEST PIT No.RMS#1
DATUMWATER LEVELDATES DUG Aug 12, 2019
GE
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RemouldedField Vane Test
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Standard Penetration Test, blows/0.3mRE
C
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mm
ST
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grey
DESCRIPTION
SAMPLES
OT
H
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S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002Halifax, NS, B3L 2C2
Canadahttp://www.exp.com
LOCATION Glace Bay, NS
CLIENT Dillon Consulting Limited
60616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120
EL
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PROJECT No.SYD-00245234-A0
TEST PIT No.RMS#1
DATUMWATER LEVELDATES DUG Aug 12, 2019
GE
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C
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TOPSOIL:Silty SAND, trace gravel andorganics (grass/roots), moist, loose(olive brown to brown)
RESIDUAL SOIL:Silty GRAVEL and SAND, moist,dense (light grey)
SEDIMENTARY BEDROCK:Alternaitng layers of siltstone,sandstone (fine/medium grain),mudstone
VOID:Mine workings
Rubble - Coal / mudstone
SEDIMENTARY BEDROCK:
330
250
95%
108%
98%
96%
103%
100%
100%
100%
100%
100%
95%
101%
99%
100%
100%
93%
105%
101%
97%
103%
85%
120%
93%100%
97%
100%
100%
100%
100%
97%
100%
100%
100%
100%
114%
100%
7
15, 50for 100mm02879
28
28
29
7
8
39
59
57
32
53
80
25
63
49
57
63
59
65
8552
79
73
31
92
93
89
61
69
79
49
44
33
SS
SS
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
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RC
RC
RC
RC
RC
RCRC
RC
RC
RC
RC
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RC
RC
RC
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1
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DESCRIPTION
SAMPLES
OT
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20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002Halifax, NS, B3L 2C2
Canadahttp://www.exp.com
LOCATION Glace Bay, NS
CLIENT Dillon Consulting Limited
0123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960
EL
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(
m
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PROJECT No.SYD-00245234-A0
TEST PIT No.RMS#2
DATUMWATER LEVELDATES DUG Aug 15, 2019
GE
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Standard Penetration Test, blows/0.3mRE
C
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Siltstone / mudstone, horizontalfractures, grey to black
COAL/SILTSTONE Mixture
SEDIMENTARY BEDROCK:Sandstone, horizontal fractures,
grey
DESCRIPTION
SAMPLES
OT
H
E
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TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002Halifax, NS, B3L 2C2
Canadahttp://www.exp.com
LOCATION Glace Bay, NS
CLIENT Dillon Consulting Limited
60616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120
EL
E
V
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(
m
)
PROJECT No.SYD-00245234-A0
TEST PIT No.RMS#2
DATUMWATER LEVELDATES DUG Aug 15, 2019
GE
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N-
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Standard Penetration Test, blows/0.3mRE
C
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ST
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FILL:Sandy SILT, some gravel andconstruction debris (concrete), tracecobbles, moist, loose to compact(dark brown to olive brown)
TILL:Silty SAND and GRAVEL, moist,
dense (reddish brown)
SEDIMENTARY BEDROCK:Alternaitng layers of siltstone,
sandstone (fine/medium grain),mudstone
COAL
SEDIMENTARY BEDROCK:Siltstone / sandstone (fine grain),
horizontal fractures, grey
COAL
SEDIMENTARY BEDROCK:Sandstone (fine to medium grain),horizontal fractures, grey
610
508%100%
93%
58%15%
100%
100%
100%
101%
100%
100%100%100%100%90%100%
97%
100%
100%
100%
101%
98%
101%
100%
100%
100%
100%
100%
88%
97%
90%
72
25020
16
00
36
12
27
64
86
5656055090
81
73
78
49
70
40
75
64
88
47
84
40
18
70
SS
SSRCRC
RC
RCRC
RC
RC
RC
RC
RC
RCRCRCRCRCRC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
1
234
5
67
8
9
10
11
12
131415161718
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002Halifax, NS, B3L 2C2
Canadahttp://www.exp.com
LOCATION Glace Bay, NS
CLIENT Dillon Consulting Limited
0123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960
EL
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PROJECT No.SYD-00245234-A0
TEST PIT No.RMS#3
DATUMWATER LEVELDATES DUG Aug 9, 2019
GE
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Standard Penetration Test, blows/0.3mRE
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WA
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FILL (Reworked Till):Sandy SILT, some gravel andconstruction debris (concrete), tracecobbles, moist, loose to compact(dark brown to olive brown)
GLACIAL TILL:Silty SAND and GRAVEL, moist,
dense (reddish brown)
SEDIMENTARY BEDROCK:Alternaitng layers of siltstone,
sandstone (fine/medium grain),mudstone
COAL
SEDIMENTARY BEDROCK:Sandstone, horizontal fractures,grey
COAL
SEDIMENTARY BEDROCK:Sandstone, horizontal fractures,grey
482
533
610
61015%93%
103%
102%
100%100%
100%
98%
103%
103%
103%
100%100%103%
98%
100%100%100%100%100%100%100%100%100%100%105%
100%
100%
100%100%100%50%80%93%100%
34
4
24
2107
25
14
2263
67
72
43
40
64
08682
73
071534662811910053082
64
92
5456710243181
SS
SS
SS
SSRCRC
RC
RC
RCRC
RC
RC
RC
RC
RC
RCRCRC
RC
RCRCRCRCRCRCRCRCRCRCRC
RC
RC
RCRCRCRCRCRCRC
1
2
3
456
7
8
910
11
12
13
14
15
161718
19
2021222324252627282930
31
32
33343536373839
DESCRIPTION
SAMPLES
OT
H
E
R
TE
S
T
S
20 40 60 80
BOREHOLE RECORD
Unconfined Compression Test
Water Content & Atterberg Limits
Undrained Shear Strength, kPa
10 20 30 40 50 60 70 80 90
Wp W Wl
DE
P
T
H
(
m
)
t: +1.902.453.5555 | f: +1.902.453.6325
7071 Bayers Road, Suite 2002Halifax, NS, B3L 2C2
Canadahttp://www.exp.com
LOCATION Glace Bay, NS
CLIENT Dillon Consulting Limited
0123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960
EL
E
V
.
(
m
)
PROJECT No.SYD-00245234-A0
TEST PIT No.RMS#4
DATUMWATER LEVELDATES DUG Aug 7, 2019
GE
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RemouldedField Vane Test
N-
V
A
L
U
E
OR
R
Q
D
Standard Penetration Test, blows/0.3mRE
C
O
V
E
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Y
mm
ST
R
A
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Photographs
PHOTOGRAPHIC RECORD OF ROCK MECHANIC BOREHOLES
GLACE BAY, NOVA SCOTIA
Recovered NQ core from RMS#1, bottom of borehole in forefront.
Recovered NQ core from RMS#2, Glace Bay, top of core in forefront
Recovered NQ core, RMS#3, bottom of core in forefront
Recovered NQ core, RMS#4, top of borehole in forefront.
UCS
Concrete Cylinder Compressive Strength
Client: File No.:
Project: Date Cast and Time:
Task Date and Time Collected:
Type of Mould:Date Received and Time:
19 44.5 36.8
21 44.5 71.3
40 44.5 28.8
50 44.5 34.4
60 44.5 45.6
70 44.5 61.8
81 44.5 42.1
92 44.5 72.1
104 44.5 79.9
118 44.5 75.8
128 44.5 102.5
138 Broken 44.5
148 44.5 126.0
157 44.5 43.7
Supplier:
Contractor:
Cast by:MPa
Truck No.:
Time cast:
Minimum Maximum
Measured slump, mm:to
Minimum Maximum
Measured air, %:to
Minimum Maximum
Nominal MSA, mm:to
Ambient temp., °C:
Location:
Initial Curing Location:
Comments:
CERTIFIED
Testing Laboratories
Concrete Testing
A283 RELEASED BY:
301 Alexandra Street, Suite A, Sydney NS, B1S 2E8
T: +1.902.562.2394 ● www.exp.com
65.5
SA#1
SA#2
SA#5
SA#6
112.1
124.2
118.0
SA#8
SA#3
SA#4
71.0
44.8
53.5
SA#7
Date Tested
Compressive
Strength
(MPa)
Specimen Number
96.2
Dillon Consulting Limited
57.3
Average Width
(mm)
(per Core)
110.9
Break
TypeLoad (kN)Depth ft Weight (g)
SYD-00245234-A0
WWTP - Geotechnical Investigation
Ticket No.:
Initial curing temp., °C:
Concrete temp., °C:
Specified Air, %:
John Buffett, P.Eng., B.Sc., RSO
Time batched:
Specified slump, mm:
RMS#1
SA#9
SA#11
SA#14
SA#10
SA#13
SA#12
159.5
NA
196.0
68.0
Spec Str. @ 28 days :
Concrete Cylinder Compressive Strength
Client: File No.:
Project: Date Cast and Time:
Task Date and Time Collected:
Type of Mould:Date Received and Time:
20 44.5 32.9
25 44.5 69.6
30 44.5 31.1
38 Broken 44.5
53 Broken 44.5
63 44.5 29.9
75 44.5 40.9
89 Broken 44.5
108 44.5 50.5
140 44.5 85.5
160 44.5 54.3
168 44.5 34.1
Supplier:
Contractor:
Cast by:MPa
Truck No.:
Time cast:
Minimum Maximum
Measured slump, mm:to
Minimum Maximum
Measured air, %:to
Minimum Maximum
Nominal MSA, mm:to
Ambient temp., °C:
Location:
Initial Curing Location:
Comments:
CERTIFIED
Testing Laboratories
Concrete Testing
A283 RELEASED BY:
301 Alexandra Street, Suite A, Sydney NS, B1S 2E8
T: +1.902.562.2394 ● www.exp.com
SA#1
SA#2
SA#5
SA#6
NA
78.5
133.0
SA#8
SA#3
SA#4
NA
48.4
NA
SA#7 63.7
Date Tested
Compressive
Strength
(MPa)
Specimen Number
46.5
Dillon Consulting Limited
51.2
Average Width
(mm)
(per Core)
108.2
Break
TypeLoad (kN)Depth ft Weight (g)
SYD-00245234-A0
WWTP - Geotechnical Investigation
Ticket No.:
Initial curing temp., °C:
Concrete temp., °C:
Specified Air, %:
John Buffett, P.Eng., B.Sc., RSO
84.5
Time batched:
Specified slump, mm:
Spec Str. @ 28 days :
SA#12 53.1
RMS#2
SA#9
SA#11
SA#10
Concrete Cylinder Compressive Strength
Client: File No.:
Project: Date Cast and Time:
Task Date and Time Collected:
Type of Mould:Date Received and Time:
33 44.5 62.9
46 44.5 68.8
56 44.5 46.3
61 44.5 61.4
72 44.5 44.6
77 44.5 53.7
91 44.5 60.7
101 44.5 126.5
114 44.5 74.1
125 44.5 39.2
130 44.5 56.0
Supplier:
Contractor:
Cast by:MPa
Truck No.:
Time cast:
Minimum Maximum
Measured slump, mm:to
Minimum Maximum
Measured air, %:to
Minimum Maximum
Nominal MSA, mm:to
Ambient temp., °C:
Location:
Initial Curing Location:
Comments:
CERTIFIED
Testing Laboratories
Concrete Testing
A283 RELEASED BY:
301 Alexandra Street, Suite A, Sydney NS, B1S 2E8
T: +1.902.562.2394 ● www.exp.com
SA#1
SA#2
SA#5
SA#6
196.8
60.9
SA#8
SA#3
SA#4
69.3
71.9
95.5
SA#7 94.5
Date Tested
Compressive
Strength
(MPa)
Specimen Number
83.6
Dillon Consulting Limited
97.9
Average Width
(mm)
(per Core)
106.9
Break
TypeLoad (kN)Depth ft Weight (g)
SYD-00245234-A0
WWTP - Geotechnical Investigation
Ticket No.:
Initial curing temp., °C:
Concrete temp., °C:
Specified Air, %:
John Buffett, P.Eng., B.Sc., RSO
Time batched:
Specified slump, mm:
Spec Str. @ 28 days :
RMS#3
SA#9
SA#11
SA#10
87.1
115.2
Concrete Cylinder Compressive Strength
Client: File No.:
Project: Date Cast and Time:
Task Date and Time Collected:
Type of Mould:Date Received and Time:
36 Broken 44.5
38 44.5 112.0
48 44.5 45.4
58 44.5 58.3
69 44.5 50.5
81 44.5 55.1
91 44.5 106.9
99.5 Broken 44.5
106 44.5 144.1
116.5 44.5 49.8
135 44.5 51.8
Supplier:
Contractor:
Cast by:MPa
Truck No.:
Time cast:
Minimum Maximum
Measured slump, mm:to
Minimum Maximum
Measured air, %:to
Minimum Maximum
Nominal MSA, mm:to
Ambient temp., °C:
Location:
Initial Curing Location:
Comments:
CERTIFIED
Testing Laboratories
Concrete Testing
A283 RELEASED BY:
301 Alexandra Street, Suite A, Sydney NS, B1S 2E8
T: +1.902.562.2394 ● www.exp.com
Spec Str. @ 28 days :
RMS#4
SA#9
SA#11
SA#10
80.5
Time batched:
Specified slump, mm:
John Buffett, P.Eng., B.Sc., RSO
Initial curing temp., °C:
Concrete temp., °C:
Specified Air, %:
Ticket No.:
Break
TypeLoad (kN)Depth ft Weight (g)
SYD-00245234-A0
WWTP - Geotechnical Investigation
Date Tested
Compressive
Strength
(MPa)
Specimen Number
85.7
Dillon Consulting Limited
NA
Average Width
(mm)
(per Core)
174.2
224.2
77.4
SA#8
SA#3
SA#4
78.5
70.7
90.7
SA#7 166.3
SA#1
SA#2
SA#5
SA#6
NA
Appendix E – Site Discussions and Client Questions – November 21,
2019
HEJV Glace Bay Wastewater System Pre‐Design Summary Report Appendices
APPENDIX E
Glace Bay Wastewater System
Archaeological Resources Impact
Assessment
HEJV Glace Bay Wastewater System Pre‐Design Summary Report Appendices
APPENDIX F
Glace Bay Wastewater System Phase I
Environmental Site Assessment
187116 ●April 8, 2019
Environmental Risk Assessments & Preliminary
Design of Seven Future Wastewater Treatment
Systems in CBRM
Phase I Environmental Site Assessment (Draft Report)
Parcel Identification Designation Numbers (PID Nos.)
15393606, 15524481, 15654882, 15821119, 15395221,
15833007, 15864085 and 15408867 in Glace Bay, Nova
Scotia
Prepared by: NJWPrepared for: CBRM
Phase I Environmental Site
Assessment (Draft Report)
Parcel Identification
Designation Numbers (PID
Nos.) 15393606, 15524481,
15654882, 15821119,
15395221, 15833007,
15864085 and 15408867 in
Glace Bay, Nova Scotia
April 8, 2019 Nadine Wambolt,
B.Tech., CET
Andrew Blackmer,
M.Sc., P.Geo.
Darrin McLean, MBA,
FEC., P.Eng
Darrin McLean, MBA,
FEC., P.Eng.
Project Manager
Issue or Revision Date Prepared By:Reviewed By:Issued By:
This document was prepared
for the party indicated herein.
The material and information in
the document reflects the
opinion and best judgment of
Harbour Engineering Joint
Venture (HEJV) based on the
information available at the
time of preparation. Any use of
this document or reliance on its
content by third parties is the
responsibility of the third party.
HEJV accepts no responsibility
for any damages suffered as a
result of third party use of this
document.
182402.00
275 Charlotte Street
Sydney, Nova Scotia
Canada
B1P 1C6
Tel: 902-562-9880
Fax: 902-562-9890
_________________
PHASE I ESA GLACE BAY_DRAFT REPORT_8APRIL2019/wu
ED: 09/04/2019 10:25:00/PD: 09/04/2019 10:25:00
April 8, 2019
Cape Breton Regional Municipality
320 Esplanade
Sydney, Nova Scotia
B1P 7B9
ATTENTION: Matthew D. Viva, P.Eng.
Manager of Wastewater Operations
Phase I Environmental Site Assessment (Draft Report)
Parcel Identification Designation Numbers (PID Nos.) 15393606, 15524481,
15654882, 15821119, 15395221, 15833007, 15864085 and 15408867
Glace Bay, Nova Scotia
Harbour Engineering Joint Venture (HEJV) is pleased to provide you with this
Phase I Environmental Site Assessment (ESA) for eight properties (i.e., PID Nos.
15393606, 15524481, 15654882, 15821119, 15395221, 15833007, 15864085 and
15408867) located in Glace Bay, Nova Scotia. Should you have any questions or
comments, please contact the undersigned at (902) 562-9880 extension 5206.
Sincerely,
Harbour Engineering Joint Venture
DRAFT DRAFT
Nadine J. Wambolt, CET, B.Tech. Darrin McLean, MBA, FEC., P.Eng.
Lead Assessor Project Manager
DRAFT
Andrew J. Blackmer, M.Sc., P.Geo.
Senior Reviewer
NJW:kme
Project No: 187116 (Dillon) and 182402.00 (CBCL)
Harbour Engineering Joint Venture Phase I ESA Glace Bay, NS i
Contents
Executive Summary ........................................................................................................................... i
CHAPTER 1 Introduction ............................................................................................................. 1
1.1 Purpose .................................................................................................................... 1
1.2 Background .............................................................................................................. 1
1.3 Standards and Limiting Conditions ............................................................................ 1
CHAPTER 2 Methodology ........................................................................................................... 2
2.1 Records Review ........................................................................................................ 2
2.2 Site Reconnaissance ................................................................................................. 2
2.3 Interviews ................................................................................................................ 2
CHAPTER 3 Phase I ESA Findings ................................................................................................ 3
3.1 Site Location and General Description ...................................................................... 3
3.2 Regional Geology/Hydrogeology............................................................................... 4
3.3 Chain-of-Title-Search ................................................................................................ 5
3.4 City Directories ......................................................................................................... 6
3.5 Aerial Photographs ................................................................................................... 6
3.6 Fire Insurance Plans and Inspection Reports ............................................................. 8
3.7 A.F. Church Mapping ................................................................................................ 8
3.8 Previous Environmental Reports/Client File Review .................................................. 8
3.9 Regulatory Agency and Database Files ...................................................................... 9
3.9.1 Department of Environment ......................................................................... 9
3.9.2 Environment and Climate Change Canada ................................................... 10
3.10 Site Visit ................................................................................................................. 10
3.10.1 Site Description ......................................................................................... 10
3.10.2 Site Services and Utilities .......................................................................... 12
3.10.3 Storage Tanks ........................................................................................... 12
3.10.4 Mechanical Equipment ............................................................................. 12
3.10.5 Drains and Sumps ..................................................................................... 12
3.10.6 Special Attention Items ............................................................................. 12
3.10.6.1 Asbestos Containing Materials .................................................... 13
3.10.6.2 Polychlorinated Biphenyls (PCBs) ................................................ 13
3.10.6.3 Lead ............................................................................................ 14
3.10.6.4 Mercury ...................................................................................... 14
3.10.6.5 Ozone-depleting Substances (ODS) ............................................. 14
3.10.6.6 Urea Formaldehyde Foam Insulation (UFFI) ................................ 15
Harbour Engineering Joint Venture Phase I ESA Glace Bay, NS ii
3.10.6.7 Noise .......................................................................................... 15
3.10.6.8 Magnetic Fields ........................................................................... 15
3.10.6.9 Radon ......................................................................................... 15
3.10.7 Chemical and Hazardous Materials Management ...................................... 15
3.10.8 Pesticides .................................................................................................. 15
3.10.9 Unidentified Substances ........................................................................... 15
3.10.10 Solid Waste Management ....................................................................... 15
3.10.11 Fill Materials ........................................................................................... 15
3.10.12 Spills, Stained Areas and Stressed Vegetation.......................................... 16
3.10.13 Pits and Lagoons ..................................................................................... 16
3.10.14 Watercourses, Ditches or Standing Water ............................................... 16
3.10.15 Air Emissions and Odours ........................................................................ 16
3.10.16 Observation of Adjoining Properties........................................................ 16
CHAPTER 4 Summary and Recommendations .......................................................................... 17
CHAPTER 5 Limitations ............................................................................................................. 19
CHAPTER 6 Closing ................................................................................................................... 20
CHAPTER 7 References ............................................................................................................. 21
Appendices
Appendix A – Figures
Appendix B – Site Photographs
Appendix C – Regulatory Correspondence
Harbour Engineering Joint Venture Phase I ESA Glace Bay i
EXECUTIVE SUMMARY
Harbour Engineering Joint Venture (HEJV) has been engaged by the Cape Breton Regional Municipality
(CBRM) to conduct a Phase I Environmental Site Assessment (ESA) on eight properties denoted by
Parcel Identification Designation Numbers (PID Nos.): 15393606, 15524481, 15654882, 15821119,
15395221, 15833007, 15864085 and 15408867 located in Glace Bay, Nova Scotia (herein referred to
as “the site” or “subject property”). The site has an approximate combined area of 31.08 acres with
designations of “commercial”, “residential” and “resource” zoning based on the Service Nova Scotia
and Municipal Relations Property Online database (accessed March 2019). The Phase I ESA is being
undertaken prior to potential purchase of the properties and future development of a Waste Water
Treatment Plant (WWTP) and lift station on the site.
This Phase I Environmental Site Assessment (ESA) was conducted in accordance with the guidelines
and principles established by the Canadian Standard Association (CSA) Standard Z768-01 for Phase I
ESAs CSA, 2001 (updated April 2003 and reaffirmed in 2016) and included a records review, site visit,
interviews with knowledgeable persons and reporting of the findings.
The following is a summary of the findings and potential sources of environmental contamination
identified during the Phase I ESA conducted at the site and the associated recommendations:
®Buildings associated with fish plant operations (Hopkins H. Ltd.) are located on the south
portion of the site (i.e., PID No. 15408867). Available fire insurance plans show a petroleum
storage tank historically located on this portion of the site. The fish plant building interiors
and the immediately surrounding grounds of these buildings were not accessible at the time
of the site visit. Current petroleum storage on this portion of the site is unknown. Further, the
exact use of these fish plant buildings is also unknown. As these on-site buildings are located
down gradient of the proposed WWTP and lift station locations, and as the anticipated
groundwater flow direction is expected to be easterly toward Glace Bay Harbour, these
buildings are unlikely to represent an environmental concern relative to the proposed
locations of the WWTP and lift station.
®Findings of a Nova Scotia Environment (NSE) environmental registry search identified a
contaminated sites complaint file for 57, 59, 61 and 63 Oceancrest Drive (located immediately
west of the site). These records, which were subject to the Freedom of Information and
Protection of Privacy (FOIPOP)Act, were subsequently requested. Findings of the FOIPOP Act
request indicate that the records were not available and that the file was destroyed as per
the NSE retention schedule. Therefore, the contents and nature of the contaminated sites
complaint are unknown. Although located immediately adjacent to the site (i.e., immediately
Harbour Engineering Joint Venture Phase I ESA Glace Bay ii
west of PID No. 15393606), these properties are approximately 200 meters (m) and 325 m
northwest of the proposed WWTP and lift station locations, respectively. Further, as the
groundwater flow direction is anticipated to be easterly, the potential for impacts to the
actual proposed WWTP and lift station locations within the site from 57, 59, 61 and 63
Oceancrest Drive are considered to be low.
®Based on the age of the fish plant buildings located on the southeast portion of the site (i.e.,
PID No. 15408867), asbestos containing materials (ACM) may be present on-site. Testing
would be required to confirm/refute the presence of ACM. It is noted that an asbestos survey
was not conducted as part of this ESA. Further, building interiors were not accessible at the
time of the site visit. Demolition practices associated with former on-site buildings, which may
have contained ACM, are unknown.
®A pad-mounted transformer was observed on the west portion of the site (i.e., PID No.
15654882) adjacent to the Bay Plex Building. It is unknown if this transformer contains
polychlorinated biphenyls (PCBs). The transformer was observed to be in good condition and
situated on a concrete pad. No evidence of leakage or staining was observed.
®An aboveground storage tank (AST) was observed on the west portion of the site (i.e., on PID
No. 15654882) in association with the Bay Plex Building. The AST was observed to be in fair
condition with some surface rusting apparent. The tank was located within a fenced
enclosure. The tank tag was not visible. Although not observed, petroleum storage tanks are
suspected on the southeast portion of the site (i.e., on PID No. 15408867) in association with
the on-site fish plant buildings. Historical heating sources and practices associated with
former on-site buildings are unknown. Further assessment would be required to assess if
former or current petroleum storage on-site has resulted in an environmental concern for the
site.
®Based on the age of the fish plant buildings located on the southeast portion of the site (i.e.,
PID No. 15408867), lead-containing paint and/or solder may be present. Testing would be
required to confirm/refute the presence of lead. Precautionary measures should be taken for
individuals considered sensitive to lead if paint is peeling or in poor condition. Paint with
elevated lead concentrations, which is in poor condition should be removed using a qualified
lead abatement contractor. Precaution should be exercised during renovations that disturb
lead-containing surfaces to minimize exposures. Demolition practices associated with former
on-site buildings, which may have had lead-containing paint and/or solder, are unknown.
®Mercury containing equipment may be present within the on-site buildings, the interiors of
which were not accessible at the time of the site visit. Further, based on the age of the fish
plant buildings, located on the southeast portion of the site (i.e., PID No. 15408867), mercury
containing paints may be present. Disposal of mercury containing paints or equipment, if
found on-site, should be in accordance with Provincial regulations. Demolition practices
associated with former on-site buildings, which may have had mercury-containing paint
and/or equipment, are unknown.
®The on-site building interiors were inaccessible at the time of the site visit; however, based
on the nature of on-site building use (i.e., fish plant and rink), ozone depleting substances
(ODS) equipment is expected to be present on-site. Maintenance to units containing ODS
should be conducted using licensed contractors. Refrigerant gases are required to be drained
and recovered by a licensed contractor prior to disposal.
Harbour Engineering Joint Venture Phase I ESA Glace Bay iii
®The on-site building interiors were inaccessible at the time of the site visit. Due to the age of
the on-site fish plant buildings, located on the southeast portion of the site (i.e., PID No.
15408867), there is potential that urea formaldehyde foam insulation (UFFI) may be present.
If found on-site, UFFI should be removed as per provincial regulations.
®Potential sources of magnetic fields observed during the site visit include a communication
tower located west and south of the site.
®Miscellaneous debris, including household appliances, metal, plastic, wood, and rubber, were
observed across the site. Debris should be removed to a licenced disposal facility.
®Portions of the site (i.e., PID Nos. 15393606, 15833007, 15395221 and 15821119) were
observed to be in-filled. Concrete, asphalt, rubber, wood, plastic and metal debris was
observed within the in-filled areas of the site. Seven fill piles were observed on the east
portion of the site (i.e., on PID No. 15408867). A gravel fill pile was observed on the southwest
portion of the site (i.e., on PID No. 15654882) in the gravel parking area of the Bay Plex. This
fill pile may be associated with snow removal activities. Sampling would be require to confirm
if impacts are present on-site from the observed fill materials.
®As noted above, the interior of the on-site Bay Plex building was not accessible at the time of
the site visit. Based on available public information, the Bay Plex building reportedly requires
mould abatement and remediation prior to planned renovation and upgrades to the facility.
®Findings of the Environment and Climate Change Canada search request are currently pending
and will be incorporated into the Final report if available at that time.
This report was prepared by Harbour Engineering Joint Venture (HEJV) for the sole benefit of our
client, the Cape Breton Regional Municipality (CBRM). The conclusions reflect HEJV’s judgment in light
of the information available to it at the time of preparation. Any use which a third party makes of this
report or any reliance on or decisions made based on it are the responsibilities of such third parties.
HEJV accepts no responsibilities for damages, if any, suffered by any third party as a result of decisions
made or actions based on this report.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 1
CHAPTER 1 INTRODUCTION
1.1 Purpose
Harbour Engineering Joint Venture (HEJV) has been engaged by the Cape Breton Regional Municipality
(CBRM) to conduct a Phase I Environmental Site Assessment (ESA) on eight properties denoted by
Parcel Identification Designation Numbers (PID Nos.): 15393606, 15524481, 15654882, 15821119,
15395221, 15833007, 15864085 and 15408867 located in Glace Bay, Nova Scotia (herein referred to
as “the site” or “subject property”). The Phase I ESA is being undertaken prior to potential purchase
of the property and future development of a Waste Water Treatment Plant (WWTP) and lift station
on the site.
1.2 Background
The objective of the Phase I ESA was to assess whether sources or potential sources of contamination
are present. Contamination is defined as “the presence of a substance of concern, or a condition, in
concentrations above appropriate pre-established criteria in soil, sediment, surface water,
groundwater, air, or structures” (CSA, 2016).
To fulfill the objective of the Phase I ESA, the following scope of work was agreed to:
®Review of records that were reasonably attainable for the site and surrounding area;
®A site visit to observe the site, building exteriors (building interiors were not accessible at the
time of the site visit) and surrounding property (as could be viewed from the site and
surrounding public lands);
®Interviews of available persons knowledgeable with respect to past and current uses of the
site; and,
®Evaluation of the findings and reporting.
1.3 Standards and Limiting Conditions
This Phase I ESA was performed in accordance with the Phase I ESA guideline document produced by
the Canadian Standards Association (CSA Z768-01 - reaffirmed in 2016). As such, this report is based
on limited visual observations made during the site visit, interviews with available persons, a review
of available historical records, and requests for information filed with government or other regulatory
agencies. This ESA did not include sample collection, analysis or measurements, and is not intended
to be a definitive investigation of contamination or other environmental concerns at the site. It is
noted that the site had patches of snow cover present on the site grounds at the time of the site visit.
On-site building interiors were not accessible. The grounds immediately surrounding the on-site fish
plant buildings (PID No. 15408867) were also not accessible at the time of the site visit.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 2
CHAPTER 2 METHODOLOGY
This section describes the methods used to conduct the historical records review, site visits and
interview activities.
2.1 Records Review
The records review consisted of requesting and reviewing information available from the client,
government, public and other agencies or parties. Information was reviewed from the following
sources:
Agencies, Information, Source Documents and Publications:
®Nova Scotia Environment (NSE) Information Access and Privacy Environmental Registry;
®Environment and Climate Change Canada;
®National Air Photo Library (NAPL) (via Environmental Risk Information Services (ERIS));
®Access Nova Scotia;
®CBRM Public Works Department;
®The Beaton Institute (local archives);
®Surficial and bedrock geology mapping;
®Topographic mapping;
®Service Nova Scotia and Municipal Relations Registry and Information Management Services;
and,
®Canadian Standard Association (CSA) Standard Z768-01 for Phase I ESAs CSA, 2001 (reaffirmed
in 2016).
2.2 Site Reconnaissance
HEJV conducted a site visit on January 30, 2019. Activities conducted during the site visit included:
®Observation of the on-site building exteriors (building interiors were not accessible at the time
of the site visit) and surrounding land at the site; and,
®Observation of the properties adjacent and nearby the site (to the extent possible) to assess
use, as could be viewed from the site and adjoining public lands.
2.3 Interviews
The interview portion of the Phase I ESA consisted of interviewing Mr. Glenn MacLeod, a former Cape
Breton Development Corporation (CBDC) employee, via email. Information obtained through the
interview has been incorporated into Section 3.10.1.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 3
CHAPTER 3 PHASE I ESA FINDINGS
This section presents and discusses the findings of the Phase I ESA. A summary of the significant
environmental issues that were identified is presented in Section 4.0. Report figures are presented in
Appendix A. Photographs taken during the site visit are presented in Appendix B.
3.1 Site Location and General Description
The site consists of the following eight properties as follows:
Site Summary
PID No./
Address
Current Owner Zoning
Designation1
Site Use2
15393606/
Dolphin
Crescent
Cape Breton Regional
Housing Authority
Residential/
Commercial
Property consists of mainly vacant land
with a baseball field located on the
north portion.
15524481/
Lower North
Street
CBRM Vacant land with a drainage ditch
located at the east boundary.
15654882/
151 Lower
North Street
Glace Bay Miners
Forum CO. LTD.,
CBRM, Nova Scotia
Housing and
Municipal Affairs,
Richard Beaver, Jessie
MacRae, Her Majesty
the Queen in Right of
the Province of Nova
Scotia
Commercial Bay Plex Recreation Centre building
and associated parking area.
15821119/
Lower North
Street
Charles H. Rigby No Information Vacant in-filled land with a drainage
ditch located at the east boundary.
15395221/
Lower North
Street
Marilyn Gillard Residential Vacant in-filled land.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 4
PID No./
Address
Current Owner Zoning
Designation1
Site Use2
15833007/
Lower North
Street
Marilyn Gillard No Information Vacant in-filled land.
15864085/
Lower North
Street
CBRM Resource
Exempt
Parking area (west portion), shoreline
(central portion) of Glace Bay Harbour
and partial water lot (east portion).
15408867/
502 Main
Street
Hopkins H. Ltd.Commercial Parking area (west portion) and fish
plant buildings (east portion).
1.Based on the Service Nova ScoƟa and Municipal RelaƟons Property Online database (accessed March 2019).
2.As observed during the January 30, 2019 site visit.
The site has an approximate combined area of 31.08 acres based on the Service Nova Scotia and
Municipal Relations Property Online database (accessed March 2019). The site location is illustrated
on Figure 1,Appendix A.
3.2 Regional Geology/Hydrogeology
To describe the regional physiography and expected hydrogeological conditions in association with
the property, the following documents were reviewed:
®Grant, D.R., 1988: Surficial Geology, Cape Breton Island, Nova Scotia; Geological Survey of
Canada, Map 1631A, scale 1:125,000; and,
®Bujak, J.P. and Donohoe, H.V., Jr., 1980. Geological Highway Map of Nova Scotia, Atlantic
Geoscience Society, Special Publications Number 1.
The surficial geology of the site is mapped as consisting of till, sandy; continuous veneer less than 2
to 4 meters (m) thick, with scattered thicker accumulations as crag-and-tail and drumlinoid hills.
Bedrock geology mapping for the area indicates the site is underlain by the Morien Group, which
consists of sandstone, siltstone, shale, conglomerate and coal. The site is relatively flat, with slight
sloping to the south and southeast. The topographic gradient suggests that the regional shallow
groundwater flow direction could be easterly toward the Atlantic Ocean.
The local shallow groundwater flow direction below the site may vary from the regional context and
be influenced by underground structures and utilities, which may be present in the vicinity of the site.
Such features are typically back-filled with coarse grain materials, which may provide a more
permeable conduit for groundwater flow when compared to the lower permeability of the native
soils.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 5
3.3 Chain-of-Title-Search
A chain-of-title search for the site was not requested as part of this assessment. Historical information
was derived from aerial photography and additional sources as noted. Review of available information
on Service Nova Scotia and Municipal Relations Registry and Information Management Services
(accessed March 2019) included the following:
Service Nova Scotia and Municipal Relations Registry
and Information Management Services Summary
PID No.Current Owner Available Documents
15393606 Cape Breton Regional
Housing Authority
·An indenture, dated August 24, 1967, between Lynk
Enterprises Limited (Grantor) and Nova Scotia Housing
Commission (Grantee).
15524481 CBRM ·No documents available.
15654882 Glace Bay Miners Forum
CO. LTD., CBRM, NS
Housing and Municipal
Affairs, Richard Beaver,
Jessie MacRae and Her
Majesty the Queen in
Right of the Province of
Nova Scotia
·A survey plan, dated January 20, 1995, depicting the
current Bay Plex Recreation Centre building (noted as
proposed on the plan) on the northeast portion of the
property and the Glace Bay Miners Forum building on
the southwest portion (this building no longer exists).
·A notice of approval of a plan of subdivision, dated
January 17, 1995. The site owners are listed as the Glace
Bay Miners Forum Company Limited, The Town of Glace
Bay and Nova Scotia Housing Commission.
15821119 Charles H. Rigby ·Survey plans and a request to register deeds, dated
November 22, 2016 and March 2, 2017.
·A registry of deeds, dated January 1, 1892 (additional
details illegible).
15395221 Marilyn Gillard ·A warranty deed, dated May 29, 2007, between Isabelle
Margaret O’Reilly and Joseph Blaise O’Reilly (Grantors)
and Marilyn Gillard (Grantee).
15833007 Marilyn Gillard ·A registrar of deeds, dated November 8, 2007,
submitted by Stephen Gillard.
15864085 CBRM ·A request to registrar deeds, dated March 10, 2005, and
submitted by CBRM.
15408867 Hopkins H. Ltd.·No documents available.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 6
3.4 City Directories
Available city directories were reviewed for the site and surrounding properties. Findings are
summarized in the following table.
City Directory Summary
Year Listings1
1928 North Street: Residential property listings and commercial property listing Cameron
Hugh & Sons Lumber (civic address 11 North Street).
Minto Street: Residential property listings.
1948 North Street: Residential properties2 and a commercial property of Cameron Hugh &
Sons Lumber (dealers) (civic address 11 North Street).
Minto Street: Mainly residential listings, one commercial listing of Phalen’s Bakery
(civic address 41) and some vacant property listings.
1961 North Street: On-site: Glace Bay Miners Forum Co Ltd (skating rink) (no civic address
provided). Remaining listings consist of residential properties2, vacant properties,
and commercial properties Cameron’s Hugh Sons Ltd. yard (no civic address
provided) and Cameron Hugh Sons Ltd. lumber.
Beach Street: Residential properties.
Minto Street: Mainly residential listings; three commercial listings of Army Navy and
Air Force Veterans welfare assistance (civic number 8), Rockets Club social club (civic
number 18) and Phalen’s Bakery (civic address 39); and some vacant property
listings.
1998 and 1999 Lower North Street: On-site: Bay Plex Recreation Centre (civic address 151 North
Street. Remaining listings consist of residential properties, properties denoted as
unverified, apartments, and commercial property Cameron’s Buildings Supplies Ltd.
(building supplies and lumber yard) (152 North Street),
Beach Street: Noted; however, there are no associated listings provided.
Minto Street: Residential listings, including apartments; commercial listings of Jones
Manor Home for Special Care (civic number 1), Sharon’s Trickle Trunk (pawn shop)
and Army Navy & Air Force Club (civic number 7), Family Services of Glace Bay (civic
number 9), Cape Breton Recycling Bottle Exchange (civic number 39); vacant listings
and unverified listings.
Dolphin Crescent: Residential, vacant and unverified listings.
Oceancrest Drive: Residential, vacant and unverified listings.3
1.Relevant streets searched were not available/included in some directories years.
2.Including civic numbers 19 and 21 North Street, which coincide with the civic addresses of the former on-site residenƟal homes (i.e., PID
Nos. 15833007, 15395221 and 15821119) based on available fire insurance mapping.
3.Including 57, 59, 61 and 63 Oceancrest Drive, discussed below in SecƟon 3.9.1.
4.Earlier directories include North Street; later directories include Lower North Street.
3.5 Aerial Photographs
Aerial photographs obtained from NAPL (via ERIS) included photographs for the years 1931, 1947,
1953, 1965, 1971, 1987, 1990 and 1999. Google Earth images for 2003, 2010, 2012, 2013, 2014, 2017
and 2018 were also reviewed. A summary of the review of the available aerial photographs and images
is presented in the following table. It is noted that the scale and resolution of the photographs varied
Harbour Engineering Joint Venture Phase I ESA Glace Bay 7
and did not always allow for a detailed evaluation of the surface conditions at the site or adjacent
properties.
Aerial Photograph Review Summary
Year Observations
1931,1947,
1953 and 1965
PID Nos. 15408867 and 15864085:The portion of the site located east of North
Street/Lower North Street is visible as vacant land and a water lot portion (i.e.,
portion of PID No.15864085). In the 1953 aerial photograph, a commercial building
is visible on the south portion of on-site PID No. 15408867. In the 1965 aerial
photograph two additional buildings and what appear to be two storage trailers or
seacans are also visible on the south portion of PID No. 15408867. A wharf and
several buildings/structures are visible immediately northeast and east of this
portion of the site. Beech Street is visible northeast of the site. Several buildings,
which appear to be a residential and commercial mix, are visible on the southwest
side of Beech Street.
PID No. 15654882: What appears to be a road is visible on the north portion of the
site, running southeast to northwest from Lower North Street/North Street. The
Glace Bay Miners Forum building is visible on-site in the 1947 aerial photograph.
Adjoining properties appear to be mainly residential with some commercial use.
PID Nos. 15833007, 15395221 and 15821119: What appears to be two residential
homes are visible on-site (denoted as 19 and 21 North Street on available fire
insurance mapping). A third residential home is visible immediately northeast of
what appears to be the northeast site boundary (i.e., northeast of PID No. 15821119).
PID Nos. 15524481 and 15393606: a building (denoted as a tennis club in the 1928
revised to 1938 Fire Insurance Mapping) and what appears to be a clearing are visible
on the southwest portion of PID No. 15393606 in the 1931 and 1947 aerial
photographs; however, it is no longer present in the 1953 aerial photograph. A
driveway, from an off-site residential home, is visible on-site intersecting both PID
Nos. 15524481 and 15393606 and connecting to Lower North Street. What appears
to be two residential homes are also visible on the northwest portion of PID No.
15393606. The remainder of these site PIDs is visible as vacant land with paths/trails
intersecting. Surrounding properties appear mainly residential in nature with some
commercial development.
1971 The storage trailers/seacans are no longer visible on-site at PID No. 15408867.
Dolphin Crescent, Bluewater Drive and Oceancrest Drive have been developed west
of the site. Several multi-unit duplex buildings are now visible along these roadways.
The residential home previously visible immediately adjacent to the northeast site
boundary of PID No. 15821119 has been removed.
1987 and 1990 In total, five commercial buildings (which appear to be associated with a fish plant)
are visible on the south portion of the site on PID No. 15408867 (southeast of Lower
North Street/North Street). A breakwater is now visible extending into Glace Bay
Harbour northeast of the site (i.e., northeast of on-site PID No. 15864085). A baseball
field is visible on the north portion of the site on PID No. 15393606. The residential
homes previously visible on-site on PID Nos. 15833007, 15395221 and 15821119
have been removed. The driveway (from an off-site residential home, which remains
present) previously visible intersecting both PID Nos. 15524481 and 15393606, and
connecting to Lower North Street, is now vegetation covered (i.e., this off-site
Harbour Engineering Joint Venture Phase I ESA Glace Bay 8
Year Observations
1987 and 1990
(cont.)
property is now accessible from Oceancrest Drive). Further residential development
is visible on the surrounding properties.
1999, 2003,
2010, 2012,
2013, 2017 and
2018
The on-site Glace Bay Miners Forum building, previously visible on-site on PID No.
15654882 has been removed. The Bay Plex Recreation Centre is now visible on-site
on PID No. 15654882. In the 2017 image, infilling is visible on-site on PID Nos.
15833007, 15395221 and 15821119, with further infilling in this area apparent in the
2018 image.
3.6 Fire Insurance Plans and Inspection Reports
Fire Insurance Plans, dated February 1928 revised to October 1938, show a foundation/skating rink
on the southwest portion of the site (PID No. 15654882). Two residential dwellings (civic number 19
and 21 North Street) and three sheds are mapped on the central portion of the site (i.e., PID Nos.
15833007, 15395221 and 15821119). A club house and tennis court are also mapped centrally on-site
on PID No. 15393606. The east and southeast portions of the site (east of lower North Street) is
mapped as vacant land. Surrounding properties are mapped as mainly residential, with a lumberyard
mapped immediately south of the site (south of PID No. 15654882), a garage with a petroleum storage
tank mapped immediately south of the site (south of PID No. 1564882) and an auto junk yard/auto
parts yard is mapped further south, across Main Street. Hugh Cameron & Sons lumber yard is mapped
southeast of the site, across North Street (i.e., southeast of PID No. 15654885). Sheds, a boat house
and warehouse are mapped southeast of the site (i.e., southeast of PID No. 15408867). Due to the
anticipated groundwater flow direction, the former garage and auto junk yard/auto parts yard are not
expected to represent a potential environmental concern for the site.
Fire insurance plans, dated March 1959, show the Glace Bay Miners Forum (skating rink) on the
southwest portion of the site (PID No. 15654882). The east portion of the site (east side of lower North
Street) (PID No. 15864085) is mapped as vacant. A packing and cold storage building (fish plant), with
two fuel oil tanks is mapped on the southeast portion of the site (east of Lower North Street) (i.e., PID
No. and 15408867). Two residential dwellings and two sheds are mapped on the central portion of
the site (i.e., PID Nos. 15833007, 15395221 and 15821119). Surrounding properties are mainly
residential, with Hugh Cameron & Sons Lumber Piling Building Materials and grounds mapped south
and southwest of the site.
No inspection reports were available for the site.
3.7 A.F. Church Mapping
A.F. Church mapping, dated March 1864, was reviewed for the site. The site is mapped; however,
labelling is mostly illegible. Legible labelling on, or near, the site includes residential listings.
3.8 Previous Environmental Reports/Client File Review
No previous environmental reports were located through the historical search request or were
provided by the client for review.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 9
3.9 Regulatory Agency and Database Files
3.9.1 Department of Environment
NSE Information Access and Privacy was contacted on January 23, 2019 to request an Environmental
Registry Search for historical information regarding environmental infractions, including reported
spills, approvals and/or orders issued at the site or on the immediately surrounding properties, and if
the lands have been used for waste disposal.
Between February 1 and 4, 2019, NSE responded that no information was located through the
Environmental Registry with regard to the site or the surrounding properties searched. However, two
records, which were subject to the Freedom of Information and Protection of Privacy (FOIPOP)Act,
were identified as follows.
®A contaminated sites complaint file pertaining to 57, 59, 61 and 63 Oceancrest Drive; and,
®A water resource management complaint file pertaining to 30 Bell Street.
Requests for these records were subsequently submitted through the FOIPOP Act.
On February 19, 2019, Dillon received a response from NSE indicating that the requested FOIPOP Act
records pertaining to a contaminated sites complaint file for 57, 59, 61 and 63 Oceancrest Drive (which
is located immediately west of the site) were not available and that the file was destroyed as per the
appropriate NSE retention schedule.
On March 11, 2019, Dillon received a response from NSE providing a portion of the FOIPOP Act records
requested pertaining to the water resource management complaint file for 30 Bell Street. The
provided records for 30 Bell Street include:
®A sequence of events record, with dates spanning between February 26 and March 5, 2012,
pertaining to dredge spoils from Glace Bay Harbour;
®A file activity report, dated February 26, 2019, indicating that John Phalen (CBRM Public
Works East Division) had received complaints from citizens regarding the disposal of dredged
materials being deposited on the lands of Joe Parsons off of Dominion Street in Glace Bay;
®A file activity report, dated February 27, 2012, regarding notification of the NSE inspector
regarding a Glace Bay Harbour dredging complaint. Correspondence indicated that NSE
received a call regarding dredge spoils from Glace Bay Harbour being deposited on lands on
Dominion Street in Glace Bay. Public Works Government Services Canada was reportedly
managing the dredge removals and a contractor was locating suitable disposal sites. The
complaint was reportedly made by CBRM East Division Public Works;
®A file activities report, dated March 2, 2012, regarding complaints related to dredge spoils
from Glace Bay Harbour; and,
®A file activity report, dated March 5, 2012, in regard to an inspection to be conducted where
the dredge spoils were stored.
Due to the distance of the disposal property on Dominion Street from the site, this record is not
expected to represent an environmental concern for the site.
These records and NSE correspondence is presented in Appendix D.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 10
3.9.2 Environment and Climate Change Canada
Environment and Climate Change Canada was contacted on February 5, 2019 to request a search
under the Access to Information Act. On March 7, 2019, Environment and Climate Change Canada
responded that an extension was required beyond the statutory 30 day limit allowed for processing
of the request. Environment and Climate Change Canada correspondence received to date is
presented in Appendix D.
3.10 Site Visit
The site visit was conducted on January 30, 2019 to identify visual or other physical evidence of actual
or potential sources of environmental impact from current or historical site use, as well as surrounding
land uses. At the time of the site visit, the site grounds had sparse patches of snow cover.
3.10.1 Site Description
The site consists of six adjoining properties on the west side of North Street/Lower North Street and
two adjoining properties on the east side of North Street/Lower North Street including:
Site Summary
PID No.Current Owner Site Use
15393606 Cape Breton Regional
Housing Authority
This portion of the site consists of mainly vacant land with
a baseball field located on the north portion.
Miscellaneous debris (i.e., household appliances, rubber,
plastic, wood and metal) was observed scattered across
the property. Several trails, which appeared to be in use by
all-terrain vehicles (ATVs) were also observed across this
portion of the site. The southeast portion of the site was
observed to be in-filled. Concrete, asphalt, rubber, wood,
plastic and metal debris was observed within the in-filled
areas of the site. Areas of frozen standing water were
observed across the site.
15524481 CBRM This portion of the site consists of vacant land, with a
drainage ditch located at the east boundary.
Miscellaneous debris (i.e., a steel barrel, plastic and wood)
was observed on the ditch banks at the time of the site
visit. Water in the ditch was frozen at the time of the site
visit.
15654882 Glace Bay Miners Forum
CO. LTD., CBRM, NS
Housing and Municipal
Affairs, Richard Beaver,
Jessie MacRae, Her
Majesty the Queen in
Right of the Province of
Nova Scotia
This portion of the site consists of the Bay Plex Recreation
Centre building and associated asphalt and gravel parking
areas. The interior of the Bay Plex building was not
accessible at the time of the site visit. Small gravel piles
were observed in the parking lot area, which may be
associated with snow removal activities. Two propane
tanks were observed on the northwest side of the Bay Plex
building. A high voltage equipment enclosure was
Harbour Engineering Joint Venture Phase I ESA Glace Bay 11
PID No.Current Owner Site Use
15654882
Continued
observed on the northwest portion of the site. A pad-
mounted transformer, a third propane tank, a fuel oil
aboveground storage tank (AST), metal and plastic debris
was observed on the northeast side of the Bay Plex
Building. Fire hydrants were also observed on-site. Based
on available public information, the Bay Plex building
reportedly requires mould abatement and remediation
prior to planned renovation and upgrades to the facility.
15821119 Charles H. Rigby This portion of the site consists of vacant in-filled land.
Concrete, asphalt, rubber, wood, plastic and metal debris
was observed within the in-filled areas of the site. A
drainage ditch is located on the east site boundary.
Miscellaneous debris (i.e., plastic and wood) was observed
on the ditch banks at the time of the site visit. Water in the
ditch was frozen at the time of the site visit.
15395221
and
15833007
Marilyn Gillard This portion of the site consists of vacant in-filled land.
Concrete barriers were observed on site. Concrete,
asphalt, rubber, wood, plastic and metal debris was
observed within the in-filled areas of the site. A drainage
ditch was observe along the southwest portion of the site.
Water within the ditch was frozen at the time of the site
visit.
15864085 CBRM This portion of the site consists of a parking area
(southwest portion), shoreline (central portion) of Glace
Bay Harbour and partial water lot (northeast portion). A
black pipe was observed on the central portion of the site
heading east to the breakwater and Glace Bay Harbour
(use unknown).
15408867 Hopkins H. Ltd.This portion of the site consists of a parking area (east
portion) and fish plant buildings (west portion). The
interior and grounds immediately surrounding the fish
plant buildings were not accessible at the time of the site
visit. Seven fill piles were observed on the northwest
portion of the site. A ditch was observed on the southeast
portion of the site, immediately northwest of the on-site
fish plant buildings. Debris (i.e., plastic and cardboard) was
observed along the length of, and in, the ditch. A ditch was
also observed at the southwest site boundary adjacent to
Beech Street. Ponded water in both ditches was frozen at
the time of the site visit.
The subject and surrounding properties are illustrated on Figure 2 and the site plan is illustrated on
Figures 3A and 3B,Appendix A.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 12
Discussions with Mr. Glenn MacLeod, a former CBDC employee, indicate that the portion of the site
designated for the proposed WWTP and lift station locations (i.e., portions of PID Nos. 15864085,
15408867, 15821119, 15395221, 15833007 and 15393606) are underlain by coal seams as follows:
®There is approximately 30 m to 50 m of cover over the Harbour Seam at the proposed lift
station location. There are no documented mine workings on the Harbour Seam under the
proposed lift station location; however, it is highly suspected that the Old Harbour Pit worked
this area. Sterling Mine workings (also on the Harbour Seam and west of the site) approach
to within approximately 100 m. Further, there is approximately 46 to 57 m of cover over the
Harbour Seam at the proposed WWTP location. The Sterling Mine (Harbour Seam) underlies
the northwest corner of the proposed WWTP location. There are no documented workings
on the Harbour Seam beneath the remainder of the site; however, it is likely the Old Harbour
Pit worked in this area.
®Phalen and Emery Seam workings also underlie the proposed on-site lift station location, and
their depths are approximately 175 m and 225 m, respectively. Phalen Seam workings also
underlie the site at a depth of approximately 182 m in the area of the proposed on-site WWTP
location. The Emery Seam also underlies the site at the proposed WWTP location at the depth
of approximately 227 m; however, there are no documented workings at the site on the seam.
3.10.2 Site Services and Utilities
The site and surrounding area are serviced by municipal water and sewer. Fire hydrants were
observed on the southwest portion of the site. Overhead power lines were observed on roadways
adjacent to the site.
3.10.3 Storage Tanks
Three propane tanks and one fuel oil storage tank were observed on the west portion of the site (i.e.,
on PID No. 15654882) in association with the Bay Plex Building. The AST was observed to be in fair
condition with some surface rusting apparent. The tank was located within a fenced enclosure. The
tank tag was not visible. Although not observed, petroleum storage tanks are suspected on the
southeast portion of the site (i.e., on PID No. 15408867) in association with the on-site fish plant
buildings. Heating sources and practices associated with former on-site buildings are unknown.
3.10.4 Mechanical Equipment
Mechanical equipment was observed on the west and southeast portion of the site in association with
the Bay Plex building and the fish plant buildings.
3.10.5 Drains and Sumps
It is unknown if drains or sumps are present within the on-site buildings, the interiors of which were
inaccessible at the time of the site visit.
3.10.6 Special Attention Items
Materials such as asbestos, polychlorinated biphenyls (PCBs), lead, ozone depleting substances (ODS),
mercury, urea formaldehyde foam insulation (UFFI), radon, excess noise and electric/magnetic fields
may be of special significance, if present, because of the heightened public concern regarding their
use. The following paragraphs address remaining special attention items relative to the site.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 13
3.10.6.1 ASBESTOS CONTAINING MATERIALS
Due to its good insulation and fire retardant properties, asbestos and asbestos containing materials
(ACM) were frequently used in building materials from the 1920s to the late 1970s. Uses included, but
were not limited to, insulation, flooring, fire rated doors, gaskets, siding and roofing materials,
drainage piping and wallboard. The use of friable ACM generally ceased in the late 1970s, with the
exception of vermiculite. Vermiculite is a naturally occurring clay mineral, which has been used in
residential and commercial buildings as insulation and as an additive in a variety of building products.
Health Canada issued a health advisory bulletin in April 2004 regarding the potential risks to health
associated with vermiculite insulation that may contain asbestos. The health risk associated with
asbestos occurs when asbestos fibres are released from various materials into the ambient air.
Asbestos may also be present in manufactured materials (e.g., cement, plaster, industrial furnaces
and heating systems, building insulation, floor and ceiling tiles and siding) manufactured after the
1970s.
Friable ACMs are materials that when dry can be crumbled, pulverized or powdered with hand
pressure and are a potential health concern should asbestos fibres become exposed and airborne.
Friable ACM can remain in a building provided that it is appropriately managed (e.g., encapsulation)
through implementation of an ACM management plan. If friable asbestos is found to be present in or
around an air supply or return system it should be removed.
Non-friable asbestos may be considered friable if disturbed. A non-friable asbestos product is one in
which the asbestos fibers are bound or locked into the product matrix, so that the fibers are not
readily released. Those materials that when dry, cannot easily be crumbled, pulverized or reduced to
a powder by hand or moderate pressure. Such a product would present a risk for fiber release only
when it is subject to significant abrasion through activities such as sanding or cutting with electric
power tools. Examples of nonfriable asbestos products include vinyl asbestos floor tiles, acoustic
ceiling tiles, and asbestos cement products. Those materials that when dry, cannot easily be crumbled,
pulverized or reduced to a powder by hand or moderate pressure.
Based on the age of the fish plant buildings located on the southeast portion of the site (i.e., PID No.
15408867), ACM may be present on-site. Testing would be required to confirm/refute the presence
of ACM. It is noted that an asbestos survey was not conducted as part of this ESA. Further, building
interiors were not accessible at the time of the site visit. Demolition practices associated with former
on-site buildings, which may have contained ACM, are unknown.
3.10.6.2 POLYCHLORINATEDBIPHENYLS (PCBS)
PCBs are commonly associated with dielectric fluids within electrical equipment manufactured in
Canada prior to approximately 1979. A pad-mounted transformer was observed on the west portion
of the site (i.e., PID No. 15654882) adjacent to the Bay Plex Building. It is unknown if this transformer
is PCB containing. The transformer was observed to be in good condition and situated on a concrete
pad. No evidence of leakage or staining was observed.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 14
Pole-mounted transformers, which may be PCB containing, were observed both on, and adjacent to,
the site. The pole-mounted transformers are the property of Nova Scotia Power Incorporated (NSPI).
These transformers are not expected to result in an environmental concern for the site.
3.10.6.3 LEAD
Paint manufacturers historically added heavy metals, including lead, to paint, because of their
desirable property such as rust prevention or as a bactericide. In 1976, Canadian regulators
established the Hazardous Materials Product Act - Liquid Coating that limited the amount of lead in
interior paint to 0.5%. In 1990, an industry agreement ceased the use of lead in exterior paint in
Canada. Subsequent to this, the Surface Coating Materials Regulations were promulgated (in 2005),
reducing the allowable lead content of paints to 0.06% (600 ppm). Other historical uses of lead in
buildings include, but are not limited to, water pipes, pipe fitting solder, roof flashings, equipment
and column base pads and concrete anchors.
Based on the age of the fish plant buildings located on the southeast portion of the site (i.e., PID No.
15408867), lead-containing paint and/or solder may be present. Testing would be required to
confirm/refute the presence of lead. Precautionary measures should be taken for individuals
considered sensitive to lead if paint is peeling or in poor condition. Paint with elevated lead
concentrations, which is in poor condition should be removed using a qualified lead abatement
contractor. Precaution should be exercised during renovations that disturb lead-containing surfaces
to minimize exposures. Demolition practices associated with former on-site buildings, which may have
had lead-containing paint and/or solder, are unknown.
3.10.6.4 MERCURY
Mercury is a metal with a tendency to bioaccumulate in the environment and is listed in Schedule I of
the Canadian Environmental Protection Act (1999), the list of toxic substances. Some species of
mercury, prevalent in the vapour phase, pose a concern to human health. Prior to 1991, mercury
compounds were used in interior latex paints. The use of mercury based compounds ceased in 1991.
Mercury containing equipment may be present within the on-site buildings, the interiors of which
were not accessible at the time of the site visit. Further, based on the age of the fish plant buildings,
located on the southeast portion of the site (i.e., PID No. 15408867), mercury containing paints may
be present. Disposal of mercury containing paints or equipment, if found on-site, should be in
accordance with provincial regulations.
3.10.6.5 OZONE-DEPLETING SUBSTANCES (ODS)
ODS, such as chlorofluorocarbons (CFCs), are manufactured compounds used in a variety of
applications such as air-conditioning coolants, industrial solvents, foam products, fire suppressants
etc. Each province in Canada has passed legislation requiring mandatory recovery and reclamation of
refrigerants during the maintenance of air-conditioning equipment.
The on-site building interiors were inaccessible at the time of the site visit. However, based on the
nature of on-site building use (i.e., fish plant and rink), ODS equipment is expected to be present on-
Harbour Engineering Joint Venture Phase I ESA Glace Bay 15
site. Maintenance to units containing ODS should be conducted using licensed contractors.
Refrigerant gases are required to be drained and recovered by a licensed contractor prior to disposal.
3.10.6.6 UREA FORMALDEHYDE FOAM INSULATION (UFFI)
UFFI was used as an insulaƟon product during the mid-1970s and was banned in Canada in 1980. The
on-site building interiors were inaccessible at the Ɵme of the site visit.Due to the age of the on-site
fish plant buildings,located on the southeast porƟon of the site (i.e., PID No. 15408867), UFFI may be
present. If found on-site, UFFI should be removed as per provincial regulaƟons.
3.10.6.7 NOISE
No issues related to noise were identified.
3.10.6.8 MAGNETIC FIELDS
The environmental effects of magnetic fields have been the subject of extensive study and are the
subject of heightened public concern, particularly in residential areas. There are no generally accepted
guidelines at present to provide specific guidance on this issue.
Potential sources of magnetic fields observed during the site visit include a communication tower
located west and south of the site.
3.10.6.9 RADON
Radon is produced due to the natural decay of radium from some soil and rock types. Radon gas may
be a concern in buildings if there is an unventilated space for gas to accumulate, such as a basement
or crawlspace. Due to the local geology, radon is not suspected. Testing of radon was not completed
as part of this Phase I ESA. Testing would be required to confirm the presence/absence of radon.
3.10.7 Chemical and Hazardous Materials Management
No chemicals or hazardous materials were observed on-site. It is noted that the on-site building
interiors were not accessible at the time of the site visit.
3.10.8 Pesticides
No known pesticide application has occurred on-site.
3.10.9 Unidentified Substances
No unidentified substances were observed on-site.
3.10.10 Solid Waste Management
Solid waste management practices associated with the on-site fish plant buildings and Bay Plex
building are unknown. Miscellaneous debris, including household appliances, metal, plastic, wood,
and rubber, were observed across the site.
3.10.11 Fill Materials
Portions of the site (i.e., PID Nos. 15393606, 15833007, 15395221 and 15821119) were observed to
be in-filled. Concrete, asphalt, rubber, wood, plastic and metal debris was observed within the in-filled
Harbour Engineering Joint Venture Phase I ESA Glace Bay 16
areas of the site. Seven fill piles were observed on the east portion of the site (i.e., on PID No.
15408867). A gravel fill pile was observed on the southwest portion of the site (i.e., on PID No.
15654882) in the gravel parking area of the Bay Plex. This fill pile may be associated with snow removal
activities.
3.10.12 Spills, Stained Areas and Stressed Vegetation
No spills, stained areas or stressed vegetation were observed. It is noted that at the time of the site
visit, the site grounds had patches of snow cover.
3.10.13 Pits and Lagoons
No pits or lagoons were observed.
3.10.14 Watercourses, Ditches or Standing Water
The northeast portion of the site consists of a water lot (Glace Bay Harbour). A watercourse intersects
the east portion of the site. Ditches are located on southeast, east and central portions of the site.
Standing water in the ditches was observed to be frozen at the time of the site visit. Areas of ponded
frozen standing water were observed across the site.
3.10.15 Air Emissions and Odours
No air emissions or odours were noted on-site at the time of the site visit.
3.10.16 Observation of Adjoining Properties
This site is surrounded to the north, northeast and northwest by residential housing. A fish plant and
Glace Bay Harbour border the site to the east and southeast. Residential homes, a lumber business
and lumber yard border the site to the south. Southeast of the site are residential homes along Edgar
Street. North Street/Lower North Street intersects the site.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 17
CHAPTER 4 SUMMARY AND RECOMMENDATIONS
®Buildings associated with fish plant operations (Hopkins H. Ltd.) are located on the south
portion of the site (i.e., PID No. 15408867). Available fire insurance plans show a petroleum
storage tank historically located on this portion of the site. The fish plant building interiors
and the immediately surrounding grounds of these buildings were not accessible at the time
of the site visit. Current petroleum storage on this portion of the site is unknown. Further, the
exact use of these fish plant buildings is also unknown. As these on-site buildings are located
down gradient of the proposed WWTP and lift station locations, and as the anticipated
groundwater flow direction is expected to be easterly toward Glace Bay Harbour, these
buildings are unlikely to represent an environmental concern relative to the proposed
locations of the WWTP and lift station.
®Findings of a NSE environmental registry search identified a contaminated sites complaint file
for 57, 59, 61 and 63 Oceancrest Drive (located immediately west of the site). These records,
which were subject to the FOIPOP Act, were subsequently requested. Findings of the FOIPOP
Act request indicate that the records were not available and that the file was destroyed as
per the NSE retention schedule. Therefore, the contents and nature of the contaminated sites
complaint are unknown. Although located immediately adjacent to the site (i.e., immediately
west of PID No. 15393606), these properties are approximately 200 m and 325 m northwest
of the proposed WWTP and lift station locations, respectively. Further, as the groundwater
flow direction is anticipated to be easterly, the potential for impacts to the actual proposed
WWTP and lift station locations within the site from 57, 59, 61 and 63 Oceancrest Drive are
considered to be low.
®Based on the age of the fish plant buildings located on the southeast portion of the site (i.e.,
PID No. 15408867), ACM may be present on-site. Testing would be required to confirm/refute
the presence of ACM. It is noted that an asbestos survey was not conducted as part of this
ESA. Further, building interiors were not accessible at the time of the site visit. Demolition
practices associated with former on-site buildings, which may have contained ACM, are
unknown.
®A pad-mounted transformer was observed on the west portion of the site (i.e., PID No.
15654882) adjacent to the Bay Plex Building. It is unknown if this transformer contains PCBs.
The transformer was observed to be in good condition and situated on a concrete pad. No
evidence of leakage or staining was observed.
®An AST was observed on the west portion of the site (i.e., on PID No. 15654882) in association
with the Bay Plex Building. The AST was observed to be in fair condition with some surface
rusting apparent. The tank was located within a fenced enclosure. The tank tag was not
visible. Although not observed, petroleum storage tanks are suspected on the southeast
Harbour Engineering Joint Venture Phase I ESA Glace Bay 18
portion of the site (i.e., on PID No. 15408867) in association with the on-site fish plant
buildings. Historical heating sources and practices associated with former on-site buildings
are unknown. Further assessment would be required to assess if former or current petroleum
storage on-site has resulted in an environmental concern for the site.
®Based on the age of the fish plant buildings located on the southeast portion of the site (i.e.,
PID No. 15408867), lead-containing paint and/or solder may be present. Testing would be
required to confirm/refute the presence of lead. Precautionary measures should be taken for
individuals considered sensitive to lead if paint is peeling or in poor condition. Paint with
elevated lead concentrations, which is in poor condition should be removed using a qualified
lead abatement contractor. Precaution should be exercised during renovations that disturb
lead-containing surfaces to minimize exposures. Demolition practices associated with former
on-site buildings, which may have had lead-containing paint and/or solder, are unknown.
®Mercury containing equipment may be present within the on-site buildings, the interiors of
which were not accessible at the time of the site visit. Further, based on the age of the fish
plant buildings, located on the southeast portion of the site (i.e., PID No. 15408867), mercury
containing paints may be present. Disposal of mercury containing paints or equipment, if
found on-site, should be in accordance with Provincial regulations. Demolition practices
associated with former on-site buildings, which may have had mercury-containing paint
and/or equipment, are unknown.
®The on-site building interiors were inaccessible at the time of the site visit; however, based
on the nature of on-site building use (i.e., fish plant and rink), ODS equipment is expected to
be present on-site. Maintenance to units containing ODS should be conducted using licensed
contractors. Refrigerant gases are required to be drained and recovered by a licensed
contractor prior to disposal.
®The on-site building interiors were inaccessible at the time of the site visit. Due to the age of
the on-site fish plant buildings, located on the southeast portion of the site (i.e., PID No.
15408867), there is potential that UFFI may be present. If found on-site, UFFI should be
removed as per provincial regulations.
®Potential sources of magnetic fields observed during the site visit include a communication
tower located west and south of the site.
®Miscellaneous debris, including household appliances, metal, plastic, wood, and rubber, were
observed across the site. Debris should be removed to a licenced disposal facility.
®Portions of the site (i.e., PID Nos. 15393606, 15833007, 15395221 and 15821119) were
observed to be in-filled. Concrete, asphalt, rubber, wood, plastic and metal debris was
observed within the in-filled areas of the site. Seven fill piles were observed on the east
portion of the site (i.e., on PID No. 15408867). A gravel fill pile was observed on the southwest
portion of the site (i.e., on PID No. 15654882) in the gravel parking area of the Bay Plex. This
fill pile may be associated with snow removal activities. Sampling would be require to confirm
if impacts are present on-site from the observed fill materials.
®As noted previously, the interior of the on-site Bay Plex building was not accessible at the time
of the site visit. Based on available public information, the Bay Plex building reportedly
requires mould abatement and remediation prior to planned renovation and upgrades to the
facility.
®Findings of the Environment and Climate Change Canada search request are currently pending
and will be incorporated into the Final report if available at that time.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 19
CHAPTER 5 LIMITATIONS
This report was prepared exclusively for the purposes, project and site location outlined in the report.
The report is based on information provided to, or obtained by HEJV as indicated in the report, and
applies solely to site conditions existing at the time of the site investigation. Although a reasonable
investigation was conducted by HEJV, HEJV’s investigation was by no means exhaustive and cannot
be construed as a certification of the absence of any contaminants from the site. Rather, HEJV 's report
represents a reasonable review of available information within an agreed work scope, schedule and
budget. It is therefore possible that currently unrecognized contamination or potentially hazardous
materials may exist at the site, and that the levels of contamination or hazardous materials may vary
across the site. Further review and updating of the report may be required as local and site conditions,
and the regulatory and planning frameworks, change over time.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 20
CHAPTER 6 CLOSING
This report was prepared by HEJV for the sole benefit of our client, CBRM. The material in the report
reflects HEJV's judgment in light of the information available to HEJV at the time of preparation. Any
use which a third party (i.e. a party other than our Client) makes of this report, or any reliance on or
decisions made based on it, are the responsibilities of such third parties. HEJV accepts no
responsibility for damages, if any, suffered by any third party as a result of decisions made or actions
based on this report.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 21
CHAPTER 7 REFERENCES
®Nova Scotia Environment (NSE) Information Access and Privacy Environmental Registry.
®National Air Photo Library (NAPL) (via Environmental Risk Information Services (ERIS).
®The Beaton Institute (archive records).
®Grant, D.R., 1988: Surficial Geology, Cape Breton Island, Nova Scotia; Geological Survey of
Canada, Map 1631A, scale 1:125,000; and,
®Bujak, J.P. and Donohoe, H.V., Jr., 1980. Geological Highway Map of Nova Scotia. Atlantic
Geoscience Society, Special Publications Number 1.
®Service Nova Scotia and Municipal Relations Registry and Information Management Services.
®Canadian Standard Association (CSA) Standard Z768-01 for Phase I ESAs CSA, 2001 (updated
April 2003 and reaffirmed in 2016).
Harbour Engineering Joint Venture Phase I ESA Glace Bay 23
APPENDIX A
Figures
MAP/DRAWING INFORMATIONNational Topographic System Mapsheets 11J/04.SITE LOCATION MAPFIGURE 1 CREATED BY: TLRCHECKED BY: NJWDESIGNED BY: NJW
PROJECT: 18-7116 DATE: APRIL 2019
1000m500
SCALE 1:50,000
0
N
S
EW250
SITE LOCATION
CAPE BRETON REGIONAL
MUNICIPALITY
PHASE I ESA
PROPOSED WWTP SITE
GLACE BAY, NS
N O V A S C O T I A
NOVA SCOTIA KEY MAP
Harbour Engineering Joint Venture Phase I ESA Glace Bay 24
APPENDIX B
Site Photographs
1. Overview of the east portion of the site (i.e., PID No. 15408867)
looking southwest.
3. View of debris observed on the on-site drainage ditch northwest
of the fish plant buildings (PID No. 15408867).
2. Overview of the fish plan buildings on the east portion of the site
(i.e., PID No. 15408867).
4. View of the east portion of the site, with fill piles and Glace Bay
Harbour visible in the background (i.e., PID Nos. 15864085 and
154088867), looking north.
5. View of the in-filled area of the site (i.e., PID Nos. 15833007,
15395221 and 15821119) looking north.
7. Overview of the central portion of the site (i.e., PID No.
15393606) looking southwest, with the on-site Bay Plex building
visible in the background (i.e., PID No. 15654882).
6. Overview of the central portion of the site (i.e., PID No.
15393606) looking south, with the on-site Bay Plex building
visible in the background (i.e., PID No. 15654882).
8. Overview of the north portion of the site (i.e., PID No. 15396306)
looking north to the on-site ball field.
9. Overview of the north portion of the site (i.e., PID No. 15396306)
looking southwest to the on-site ball field.
11. View of the on-site transformer adjacent to the Bay Plex building
(i.e., PID No. 15654882) looking northeast.
10. View of miscellaneous debris observed on the west portion of
the site (i.e., PID No. 15393606) looking east.
12. View of the on-site AST at the Bay Plex building (i.e., PID No.
15654882) looking west.
Harbour Engineering Joint Venture Phase I ESA Glace Bay 25
APPENDIX C
Regulatory Correspondence
PO Box 442
Halifax, Nova Scotia
B3J 2P8
Information Access ph: (902) 424-2549
and Privacy fax: (902) 424-6925 February 1, 2019 Our file # ENV-2019-0186/0197
Email: nwambolt@dillon.ca
Nadine Wambolt Dillon Consulting Ltd. 275 Charlotte Street Sydney NS B1P 1C6
Dear Ms. Wambolt: RE: 151 Lower North St. Lot 1 (PID 15654882); 540 Main St. Lot 1 (PID 15575814); 23 Main St. (PID 15395080); 27 Main St. (PID 15395072); 554 Main St. (PID
15395064); 556 Main St. (PID 15395056); 12 Minto St. (PID 15394968); 9 Minto ST. (PID 15395551); 15 Minto St. (PID 15395643); Minto St. (PID 15525132); 22 Minto St. (PID 15394943); and 1-7 Dolphin Cres. (PID 15856784), Glace Bay
I refer to your enquiry of the Environmental Registry received January 23, 2019. We acknowledge receipt of payment for 12 properties.
No information was located through the Environmental Registry with regards to the above
referenced properties.
Nova Scotia Environment makes no representations or warranties on the accuracy or completeness of the information provided.
Sincerely,
Tina Skeir Information Access Office
PO Box 442
Halifax, Nova Scotia
B3J 2P8
Information Access ph: (902) 424-2549
and Privacy fax: (902) 424-6925 February 1, 2019 Our file # ENV-2019-0232/0241
Email: nwambolt@dillon.ca
Nadine Wambolt Dillon Consulting Ltd. 275 Charlotte Street Sydney NS B1P 1C6
Dear Ms. Wambolt: RE: 9,11,13&15 Dolphin Cres. (PID 15856784); 17,19,21&23 Dolphin Cres. (PID 15856784); 25,27,29&31 Dolphin Cres. (PID 15856784); 33&35 Dolphin Cres. (PID
15856784); 45&47 Oceancrest Dr. (PID 15856750); 49&51 Oceancrest Dr. (PID 15856750); 26&28 Oceancrest Dr. (PID 15854292); 30&32 Oceancrest Dr. Lot 3 (PID 15854292); 34&36 Oceancrest Dr. Lot 3 (PID 15854292); and 38&40 Oceancrest Dr. Lot 3 (PDI 15854292), Glace Bay
I refer to your enquiry of the Environmental Registry received January 23, 2019. We acknowledge receipt of payment for 10 properties.
No information was located through the Environmental Registry with regards to the above referenced properties.
Nova Scotia Environment makes no representations or warranties on the accuracy or completeness of the information provided.
Sincerely,
Tina Skeir Information Access Office
PO Box 442
Halifax, Nova Scotia
B3J 2P8
Information Access ph: (902) 424-2549
and Privacy fax: (902) 424-6925 February 1, 2019 Our file # ENV-2019-0203/0222
Email: nwambolt@dillon.ca
Nadine Wambolt Dillon Consulting Ltd. 275 Charlotte Street Sydney NS B1P 1C6
Dear Ms. Wambolt: RE: 15&29 Dolphin Cres. (PID 15393606); 2,4,6,&8 Dolphin Cres. (PID 15856776); 69&71 Oceancrest Dr. (PID 15393820); 57,59,61&63 Oceancrest Dr. Lot 5 (PID
15856768); 41&43 Oceancrest Dr. Lot 4 (PID 15856750); 22&24 Oceancrest Dr. Lot 3 (PID 15854292); 35 Oceancrest Dr. (PID 15394703); 29 Oceancrest Dr. (PID 15394695); 722 Minto St. (PID 15394612); 72 Minto St. (PID 15394604); 76 Minto St. (PID 15394596); 80 Minto St. (PID 15394588); 84 Minto St. (PID 15394570); 86 Minto St. (PID 15394562); 90 Minto St. (PID 15394554); 4 Devison Lane (PID
15394521); 14 Devison Lane (PID 15394505); 18 Devison Lane (PID 15394497): 22 Devison Lane (PID 15394489); and 26 Devison Lane (PID 15394471), Glace Bay
I refer to your enquiry of the Environmental Registry received January 23, 2019. We acknowledge receipt of payment for 20 properties.
No information was located through the Environmental Registry with regards to the above referenced properties.
A contaminated sites complaint file (file# 33000-40-SYD-2010-1960588) pertaining to 57,59,61&63 Oceancrest Dr., Glace Bay was located. These records, while not in the Environmental Registry, may be relevant to your request. Should you feel you require these records, they are subject to the Freedom of Information and Protection of Privacy (FOIPOP) Act.
FOIPOP applications can be submitted by filling out the attached application form. Please quote
the Environmental Registry number in your FOIPOP application.
Nova Scotia Environment makes no representations or warranties on the accuracy or completeness of the information provided. Sincerely,
Tina Skeir Information Access Office
PO Box 442
Halifax, Nova Scotia
B3J 2P8
Information Access ph: (902) 424-2549
and Privacy fax: (902) 424-6925
February 4, 2019 Our file # ENV-2019-0270/0280
Email: nwambolt@dillon.ca
Nadine Wambolt Dillon Consulting Ltd. 275 Charlotte Street Sydney NS B1P 1C6
Dear Ms. Wambolt:
RE: 161&163 Lower North St. (PID 15395114); 169 Lower North St. (PID 15395122); 165 Lower North St. (PID 15395130); 502 Main St. (PID 15408867); 30 Bell St. (PID 15408883); 500 Main St. (PID 15408883); 25 Harbour St. (PID 15408883); 48 Harbour St. (PID 15408883); Lot 98-1 Lower North St. (PID 15864085); Lower North St. (PDI 15525165); and Lower North St. (PID 15524473), Glace Bay
I refer to your enquiry of the Environmental Registry received January 24, 2019. We acknowledge receipt of payment for 10 properties.
No information was located through the Environmental Registry with regards to the above
referenced properties.
A water resource management complaint file (file# 95100-40-SYD-2012-1721855) pertaining to 30 Bell St., Glace Bay was located. These records, while not in the Environmental Registry, may be relevant to your request. Should you feel you require these records, they are subject to the Freedom of Information and Protection of Privacy (FOIPOP) Act. FOIPOP applications can be
submitted by filling out the attached application form. Please quote the Environmental Registry number in your FOIPOP application.
Nova Scotia Environment makes no representations or warranties on the accuracy or completeness of the information provided.
Sincerely,
Tina Skeir
Information Access Office
PO Box 442
Halifax, Nova Scotia
B3J 2P8
Information Access ph: (902) 424-3600
and Privacy fax: (902) 424-6925
March 11, 2019
Nadine Wambolt
275 Charlotte St
Sydney NS B1P 1C6
Dear Nadine Wambolt:
Re: You are entitled to part of the information you requested – 2019-08468-ENV
Environment received your application for access to information under the Freedom of Information
and Protection of Privacy Act on February 10, 2019.
In your application, you requested a copy of the following records:
A water resource management complaint file #95100-40-SYD-2012-1721855
pertaining to 30 Bell Street, Glace Bay, Nova Scotia as identified in Environmental
Registry Search ENV-2019-0270/0280.
You are entitled to part of the records requested. However, we have removed some of the
information from this record according to subsection 5(2) of the Act. The severed information is
exempt from disclosure under the Act for the following reason:
• Section 20: unreasonable invasion of personal privacy.
The remainder of the records are enclosed.
You have the right to ask for a review of this decision by the Information Access and Privacy
Commissioner (formerly the Review Officer). You have 60 days from the date of this letter to
exercise this right. If you wish to ask for a review, you may do so on Form 7, a copy of which is
attached. Send the completed form to the Information Access and Privacy Commissioner, P.O. Box
181, Halifax, Nova Scotia B3J 2M4.
Please contact Haley Kenny at 902-424-6920 or by e-mail at Haley.Kenny@novascotia.ca, if you
need further assistance in regards to this application.
Yours truly,
Haley Kenny
IAP Administrator
Attch.
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I*I Environment and
Climate Change Canada
Environnement et
Changement climatique Canada
Fonlqine Building
200 Sacri Coeur Bh,d. l3th Floor
Gatineau, Qutbec KIA 0H3
YourFrle Volrerelere.ce
lD: 1 168991
Our Frle Nolre rele.ence
E-2018-O2146 IMK
February 5, 2019
Dear lvls. Wambolt,
This is to acknowledge receipt on February 5, 2019 of your request under the Access lo
lnformation Act Ior:
"Owners: Her Majesty the Queen in Right of Canada & Public Works and Government
Services Canada
Properties/addresses (PWGSC):
PID Number: 15408883 with associated civic addresses:
30 Bell Street, Glace Bay, Cape Breton County, NS;
500 Main Street, Glace Bay, Cape Breton County, NS;
25 & 48 Harbour Street, Glace Bay, Cape Breton County, NS;
PID Numbers: 15599798 and 1552M73
Lower North Street, Glace Bay, Cape Breton County, NS; and
PID Number: 15525165 (Her Majesty the Queen & PWGSC)
Lower North Street, Glace Bay, Cape Breton County, NS
I would like to request any available records you have associated with the
Properties/addresses. Also, see the maps for location of sites.
Authorization: {Signed consent will be provide prior to receipt of the located
information)"
l2
Canadei
Irils. Nadine Wambolt
Dillon Consulting Limited
275 Charlotte Street
Sydney, Nova Scotia 81 P 1C6
Please note thal this also serves as a receipt for the $5.00 application fee
We have started processing your request and will contact you as soon as possible. Please find
enclosed our principles for assisting your request.
lf you have any questions regarding this request, do not hesitate to contact me at 819-938-3761
or by email at lvlarla.Komadina@Canada.ca. Please quote the above file number on all future
correspondence concerning this request.
Yours sincerely,
/,"rdMarla Komadina
Access to lnformation and Privacy Division
Enclosure
/.*
Our principles for assisting your request
ln processing your request under the Access to lnformation Act or Privacy Act, we will:
1. Process your request without regard to your identity.
2. Offer reasonable assistance throughout the request process.
3. Provide information on the Access to lnformation Act or Privacy Act, including
information on the processing of your request and your right to complain to the
lnformation Commissioner of Canada or Privacy Commissioner of Canada.
4. lnform you as appropriate and without undue delay when your request needs to be
clarified.
5. Make every reasonable effort to locate and retrieve the requested records/personal
information under the control of Environment and Climate Change Canada.
6. Apply limited and specific exemptions to the requested records/personal information
7. Provide accurate and complete responses.
B. Provide timely access to the requested information/personal information.
9. Provide records/personal information in the format and official language requested,
as appropriate.
10. Provide an appropriate location to examine the requested information/personal
information.