HomeMy WebLinkAbout182402-New-Victoria-Wastewater-Pre-Design-Summary-Report-Final
182402.00 / 187116.00 ● Final Report ● March 2020
Environmental Risk Assessments
& Preliminary Design of Seven Future
Wastewater Treatment
Systems in CBRM
New Victoria Wastewater Interception & Treatment System
Pre-Design Summary Report
Prepared by:
Prepared for:
New Victoria WW Interception &
Treatment System Pre-Design
Summary Report-Draft
March 27, 2020 Darrin McLean James Sheppard Darrin McLean
New Victoria WW Interception &
Treatment System Pre-Design
Summary Report-Draft
March 2, 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.
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: New Victoria Wastewater Interception & Treatment System – Pre-Design Summary
Report
Enclosed, please find, for your files, a copy of the final draft of the Pre-Design Summary Report
for the New Victoria Wastewater Interception & Treatment System.
This report presents a description of proposed wastewater interception and treatment
infrastructure upgrades for the New Victoria 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. Also, a desktop geotechnical review of the wastewater
treatment facility site is provided, along with an archaeological resources impact assessment
review for all sites of proposed wastewater infrastructure. 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)
HEJV New Victoria 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 ............................ 3
2.2.1 Lift Station Sites .................................................................................................................. 3
2.2.2 Linear Infrastructure ........................................................................................................... 4
CHAPTER 3 Existing Wastewater Collection System Upgrades / Assessments ................................ 5
3.1 Sewage Pump Station Upgrades ......................................................................................... 5
3.2 Asset Condition Assessment Program ................................................................................ 5
3.3 Sewer Separation Measures ............................................................................................... 5
CHAPTER 4 Wastewater Treatment System .................................................................................. 6
4.1 Recommended Wastewater Treatment Facility ................................................................. 6
4.2 Wastewater Treatment Facility Land Acquisition Requirements ....................................... 7
4.3 Wastewater Treatment Facility Site Desktop Geotechnical Review .................................. 7
CHAPTER 5 Wastewater System Archaeological Resources Impact Assessment ............................. 9
5.1 Archaeological Resources Impact Assessment ................................................................... 9
CHAPTER 6 Wastewater Infrastructure Costs .............................................................................. 11
6.1 Wastewater Interception & Treatment Capital Costs ...................................................... 11
6.2 Wastewater Interception & Treatment Annual Operating Costs ..................................... 12
6.3 Annual Capital Replacement Fund Contribution Costs..................................................... 12
6.4 Existing Wastewater Collection System Upgrades / Assessment Costs ........................... 14
CHAPTER 7 Project Implementation Timeline ............................................................................. 15
7.1 Implementation Schedule ................................................................................................. 15
Appendices
A New Victoria Collection System Pre-Design Brief
B New Victoria Wastewater Treatment System Pre-Design Brief
C New Victoria Environmental Risk Assessment Report
D New Victoria Wastewater Treatment Facility Site Desktop Geotechnical Review
E New Victoria Wastewater System Archaeological Resources Impact Assessment
HEJV New Victoria 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 New Victoria, 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 that proposed infrastructure upgrades
for the New Victoria 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. Also, a desktop
geotechnical review of the wastewater treatment facility site is provided, along with an archaeological
resources impact assessment review for all sites of proposed wastewater infrastructure. 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 New Victoria, 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 New Victoria system has been classified as low risk under the federal Wastewater System Effluent
Regulations (WSER) under the Fisheries Act, requiring implementation of treatment systems by the year
2040.
1.3 Description of Existing Wastewater Collection System
Sewage for the community of New Victoria is conveyed to a single pipe outfall at the western end of
Daley Road. A 200mm diameter outfall extends 120m beyond the existing bank with a top of pipe
elevation set for 1 m below the low water level. A combination of gravity and pumped systems are
HEJV New Victoria Wastewater System Pre-Design Summary Report 2
used in the existing New Victoria sewer collection system. The pumped systems in New Victoria
include three pump stations and a series of E-One Pumping systems located as follows:
Highway 28 pump station – located on Highway 28, 40m west of Lameys Lane;
Browns Road – located near the intersection of Browns Road and Browns Road Extension;
New Waterford WTP – located at the New Waterford Water Treatment Plant; and
E-One pumping systems have been employed in the sewer shed at several locations including:
o New Waterford Lake Road;
o Daley Road;
o Browns Road Extension; and,
o Burkes Road Extension
1.4 Service Area Population
For New Victoria, the service area population was estimated to be 604 people in 283 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 conditions is considered the most reasonable approach.
HEJV New Victoria 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 New Victoria Wastewater System includes the
following major elements:
A 300mm diameter interceptor sewer collects flow from Daley Road and conveys it 315m
northward to the proposed WWTP site to the north of Daley Road.
The remaining 22 homes that are located below the gravity interceptor connection will still
utilize the existing 200mm diameter sewer on Daley Road.
A small pump station LS-NV1 will be installed near the end of Daley Road to pump the
remaining sewage from Daley Road to the gravity interceptor sewer.
A 200mm diameter gravity main is to be constructed at the outlet to the WWTP to connect
back to the existing New Victoria Outfall.
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 a new sewage pumping station in the system will require property acquisitions as
shown in the table below.
Table 1 - Lift Station Site Land Acquisition Requirements
PID# Property
Owner Assessed Value Description Size Required Purchase Entire
Lot (Y/N)
15516586 Melvin J
Cormier unknown PS Site N/A Y
15516594 Melvin J
Cormier
unknown PS Site N/A Y
15516602 Melvin J
Cormier
unknown PS Site N/A Y
15516651 Melvin J
Cormier
unknown PS Site N/A Y
HEJV New Victoria 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 ............................ 3
2.2.1 Lift Station Sites .................................................................................................................. 3
2.2.2 Linear Infrastructure ........................................................................................................... 4
CHAPTER 3 Existing Wastewater Collection System Upgrades / Assessments ................................ 5
3.1 Sewage Pump Station Upgrades ......................................................................................... 5
3.2 Asset Condition Assessment Program ................................................................................ 5
3.3 Sewer Separation Measures ............................................................................................... 5
CHAPTER 4 Wastewater Treatment System ................................................................................... 6
4.1 Recommended Wastewater Treatment Facility ................................................................. 6
4.2 Wastewater Treatment Facility Land Acquisition Requirements ....................................... 7
4.3 Wastewater Treatment Facility Site Desktop Geotechnical Review .................................. 7
CHAPTER 5 Wastewater System Archaeological Resources Impact Assessment ............................. 9
5.1 Archaeological Resources Impact Assessment ................................................................... 9
CHAPTER 6 Wastewater Infrastructure Costs ............................................................................... 11
6.1 Wastewater Interception & Treatment Capital Costs ...................................................... 11
6.2 Wastewater Interception & Treatment Annual Operating Costs ..................................... 12
6.3 Annual Capital Replacement Fund Contribution Costs .................................................... 12
6.4 Existing Wastewater Collection System Upgrades / Assessment Costs ........................... 14
CHAPTER 7 Project Implementation Timeline .............................................................................. 15
7.1 Implementation Schedule ................................................................................................. 15
Appendices
A New Victoria Collection System Pre‐Design Brief
B New Victoria Wastewater Treatment System Pre‐Design Brief
C New Victoria Environmental Risk Assessment Report
D New Victoria Wastewater Treatment Facility Site Desktop Geotechnical Review
E New Victoria Wastewater System Archaeological Resources Impact Assessment
HEJV New Victoria 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 New Victoria, 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 that proposed infrastructure upgrades
for the New Victoria 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. Also, a desktop
geotechnical review of the wastewater treatment facility site is provided, along with an archaeological
resources impact assessment review for all sites of proposed wastewater infrastructure. 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 New Victoria, 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 New Victoria system has been classified as low risk under the federal Wastewater System Effluent
Regulations (WSER) under the Fisheries Act, requiring implementation of treatment systems by the year
2040.
1.3 Description of Existing Wastewater Collection System
Sewage for the community of New Victoria is conveyed to a single pipe outfall at the western end of
Daley Road. A 200mm diameter outfall extends 120m beyond the existing bank with a top of pipe
elevation set for 1 m below the low water level. A combination of gravity and pumped systems are
HEJV New Victoria Wastewater System Pre‐Design Summary Report 2
used in the existing New Victoria sewer collection system. The pumped systems in New Victoria
include three pump stations and a series of E‐One Pumping systems located as follows:
Highway 28 pump station – located on Highway 28, 40m west of Lameys Lane;
Browns Road – located near the intersection of Browns Road and Browns Road Extension;
New Waterford WTP – located at the New Waterford Water Treatment Plant; and
E‐One pumping systems have been employed in the sewer shed at several locations including:
o New Waterford Lake Road;
o Daley Road;
o Browns Road Extension; and,
o Burkes Road Extension
1.4 Service Area Population
For New Victoria, the service area population was estimated to be 604 people in 283 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 conditions is considered the most reasonable approach.
HEJV New Victoria 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 New Victoria Wastewater System includes the
following major elements:
A 300mm diameter interceptor sewer collects flow from Daley Road and conveys it 315m
northward to the proposed WWTP site to the north of Daley Road.
The remaining 22 homes that are located below the gravity interceptor connection will still
utilize the existing 200mm diameter sewer on Daley Road.
A small pump station LS‐NV1 will be installed near the end of Daley Road to pump the
remaining sewage from Daley Road to the gravity interceptor sewer.
A 200mm diameter gravity main is to be constructed at the outlet to the WWTP to connect
back to the existing New Victoria Outfall.
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 a new sewage pumping station in the system will require property acquisitions as
shown in the table below.
Table 1 ‐ Lift Station Site Land Acquisition Requirements
PID# Property
Owner Assessed Value Description Size Required Purchase Entire
Lot (Y/N)
15516586 Melvin J
Cormier unknown PS Site N/A Y
15516594 Melvin J
Cormier
unknown PS Site N/A Y
15516602 Melvin J
Cormier
unknown PS Site N/A Y
15516651 Melvin J
Cormier
unknown PS Site N/A Y
HEJV New Victoria Wastewater System Pre‐Design Summary Report 4
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 Size Required Purchase Entire
Lot (Y/N)
15518798 Pauline
McDonald $5,100
Gravity
Interceptor
and Outlet
10m (Construction)
6m (Final)
X 135m length
N
15518418 Pauline
McDonald $2,000 WWTP Site
10m (Construction)
6m (Final)
X 62m length
N
15267107
Keith Jackson,
Heather Grant,
Earl Keith
Jackson
$97,700 WWTP Site
10m (Construction)
6m (Final)
X 64m length
N
15267099 Francis James
JR Fahey $143,700 WWTP Site
10m (Construction)
6m (Final)
X 67m length
N
15319155 Carol Sheppard Unknown
Gravity
Interceptor N/A Y
15517907 Melvin J
Cormier
Unknown
Outlet
10m (Construction)
6m (Final)
X 35m length
N
15516693 Melvin J
Cormier
Unknown Outlet N/A Y
15516701 Melvin J
Cormier
Unknown Outlet N/A Y
15516719 Melvin J
Cormier
Unknown Outlet N/A Y
HEJV New Victoria Wastewater System Pre‐Design Summary Report 5
CHAPTER 3 EXISTING WASTEWATER COLLECTION
SYSTEM UPGRADES / ASSESSMENTS
3.1 Sewage Pump Station Upgrades
HEJV has reviewed the existing New Victoria Collection System for potential upgrades to the existing
sewage pumping stations. There are currently three pump stations in the community of New Victoria.
The age of the existing stations is on average 24‐years old. The New Victoria WWTP has been classified
as a low priority system and has an implementation deadline of 2040. Considering that 2040 is 21‐
years in the future, plans should be made to upgrade each of these stations as part of the interception
work to be completed in the community. Due to their age, the necessity to upgrade these stations
may occur prior to the implementation of the interceptor sewer project. Therefore, 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 New Victoria 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; and
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 New Victoria. 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.
HEJV New Victoria Wastewater System Pre-Design Summary Report 6
CHAPTER 4 WASTEWATER TREATMENT SYSTEM
4.1 Recommended Wastewater Treatment Facility
The recommended wastewater treatment facility for New Victoria is an aerated lagoon. In aerated
lagoons, oxygen is supplied by mechanical aeration, which in newer systems is typically accomplished
by subsurface diffused aeration. They have average retention times ranging from 5 to 30 days, with
30 days being common in Atlantic Canada. The WWTP would provide the following general features:
1. Preliminary treatment involving a manually-cleaned bar screen;
2. Secondary treatment involving three aerated lagoon basins divided into four aerated cells and
one quiescent settling zone by means of berms or floating baffles;
3. An aeration system consisting of blowers and low pressure air distribution piping;
4. Disinfection of the treated wastewater with the use of ultraviolet (UV) disinfection unit;
5. A small process building to provide space for blowers, UV disinfection equipment, basic office
space, laboratory space, instrumentation equipment, and a washroom; and
6. Site access and parking, along with site fencing.
The proposed site of the New Victoria WWTP is located just to the north of Daley Road in New Victoria.
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 604
Flow (m3/day) 840 1,050
CBOD Load (kg/day) 48 58
TSS Load (kg/day) 169 203
TKN Load (kg/day) 8 10
A detailed description of the proposed wastewater treatment system, including preliminary layout
drawings is provided in Appendix B.
HEJV New Victoria Wastewater System Pre‐Design Summary Report 7
The associated Environmental Risk Assessment Report, which outlines effluent criteria for the
proposed wastewater treatment facility for New Victoria 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 Description Size Required (m2) Purchase Entire
Lot (Y/N)
15267057 Rodney Andrew
Young $50,800 WWTP Site 95,700 N
4.3 Wastewater Treatment Facility Site Desktop Geotechnical Review
A review of the subsurface soil conditions at the proposed site for the New Victoria Wastewater
Treatment Facility was carried out. 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 and a Coastal Protection Plan will be required for the site;
2. The area west and southwest of 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. It is anticipated that the overburden soil will be in a very moist to wet condition near the
surface, in particular near marshy/boggy areas on the site. This will create some problems
during site preparation and construction. A Surficial and Groundwater Control Plan should be
developed for the site; and
5. The presence of uncontrolled fills, foundation and construction debris is suspected on the site
due to historical activities (residences and development) on the site.
HEJV New Victoria Wastewater System Pre‐Design Summary Report 8
The review recommends an intrusive borehole and test pit program on the site to further define the
subsurface conditions.
A copy of the New Waterford WWTP site geotechnical review report is provided in Appendix D.
HEJV New Victoria Wastewater System Pre‐Design Summary Report 9
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 New Victoria
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.
Mi’kmaw peoples and their ancestors are known to have settled intensively throughout Unama’kik
prior to European contact and likely took advantage of the island’s abundant natural resources. Their
presence is documented by sixteenth century explorers to the region and following the permanent
settlement of Europeans in the 17th and 18th centuries, they carried on trade particularly with the
French who had occupied and fortified nearby Louisbourg. It is believed that the Mi’kmaq had
permanent settlements at nearby Solagatig (Mira) and Miletgj (Lingan) as well as at Sydney Harbour
but there is no direct evidence that they settled in the immediate vicinity of the study area.
The historic background study indicates that the study area was settled at least as early as so the mid‐
to late‐19th century and the reconnaissance revealed two features related to occupation during that
time. 1931 aerial photography suggests the building with the stone foundation had been abandoned
for some time prior to 1931 as it appears as a small ground anomaly on images of that period. Nothing
on the surface of the feature could indicate an age for the construction and occupation of the
structure.
While most of the study area was clearly visible during the reconnaissance, the southeast corner as
well as the far north side of the proposed WWTP could not be adequately surveyed due to dense
thickets of blackberry bushes which obscured the view of the ground and could not be traversed.
Therefore, it is recommended that these areas be surveyed when the blackberry bushes can be
cleared so that the underlying ground is visible, to ensure that no associated features are located
within the proposed footprint which may be impacted by construction.
HEJV New Victoria Wastewater System Pre‐Design Summary Report 10
Due to the unknown age and function of the building with the stone foundation, it is also
recommended that formal subsurface testing be conducted in the area of the foundation. This should
include excavation of 1 meter by 1 meter units on an alternating grid transecting the feature north‐
south and east‐west. This would entail the excavation of approximately 15 one‐meter‐by‐one‐meter.
Units until the excavation reaches natural till. Given that the concrete foundation represents a house
that was still occupied well into the 20th century, it is considered to be of low archaeological
significance and, therefore, no further active mitigation is recommended for this feature. Maritime
Archaeological Resource Inventory records have been submitted to the Department of Communities,
Culture and Heritage for both features.
The remaining area was clearly visible during the reconnaissance and no evidence of archaeological
deposits were noted. Much of the area is relatively barren and wet along the headland where the lift
station and gravity sewer will be constructed and the proposed route of the gravity sewer from the
south end of the WWTP out to Daley Road is very wet and void of archaeological resources, as is the
proposed location of the lift station. Existing gravity sewer runs under Daley Road and at least two
manholes were noted along the road, indicating that the subsurface of the road has been previously
impacted. Therefore, no further active mitigation is recommended for these areas.
However, in the event that archaeological resources are encountered in the study area, 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.
New Victoria falls within a zone that is known for prevalent Carboniferous fossil flora, and there is a
possibility that fossil fauna may be present as well in rare instances. Although fossils as well as
archaeological material fall under the Special Places Protection Act, as archaeologists rather than
paleontologists it is difficult to accurately state the possible significance of these fossil flora and rare
fauna. Therefore, 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 New Victoria 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 New Victoria Wastewater System Pre‐Design Summary Report 11
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 New Victoria is presented in the table below.
Table 5 ‐ New Victoria Wastewater Interception & Treatment System Capital Costs
Project Component Capital Cost (Excluding
Taxes)
Wastewater Interception System $718,720
Wastewater Interception System Land Acquisition $183,200
Subtotal 1: $901,920
Construction Contingency (25%): $180,000
Engineering (10%): $72,000
Total Wastewater Interception: $1,153,920
Wastewater Treatment Facility $4,535,000
Wastewater Treatment Facility Land Acquisition $200,000
Subtotal 2: $4,735,000
Construction Contingency (25%): $1,133,750
Engineering (12%): $544,000
Total Wastewater Treatment: $6,412,750
Total Interception & Treatment System: $7,566,670
HEJV New Victoria Wastewater System Pre‐Design Summary Report 12
6.2 Wastewater Interception & Treatment Annual Operating Costs
An opinion of probable annual operating costs for the recommended wastewater interception and
treatment system for New Victoria is presented in the table below.
Table 6 ‐ New Victoria Wastewater Interception & Treatment System Operating Costs
Project Component
Annual Operating
Cost (Excluding
Taxes)
Wastewater Interception System
General Linear Maintenance Cost $500
General Lift Station Maintenance Cost $3,500
Employee O&M Cost $3,500
Electrical Operational Cost $1,000
Backup Generator O&M Cost $1,100
Total Wastewater Interception Annual Operating Costs: $9,600
Wastewater Treatment Facility
Staffing $50,000
Power $17,800
Sludge Disposal $6,000
Maintenance Allowance $3,000
Total Wastewater Treatment Annual Operating Costs: $76,800
Total Interception & Treatment System Annual Operating Costs: $86,400
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
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.
HEJV New Victoria Wastewater System Pre‐Design Summary Report 13
Table 7 ‐ New Victoria Wastewater Interception & Treatment System Capital Replacement Fund
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) $432,620 75 1.3% $5,624
Pump Station Structures (Concrete
Chambers, etc.) $157,355 50 2.0% $3,147
Pump Station Equipment (Mechanical /
Electrical) $128,745 20 5.0% $6,437
Subtotal $718,720 ‐ ‐ $15,208
Construction Contingency (Subtotal x 25%): $3,802
Engineering (Subtotal x 10%): $1,521
Wastewater Interception System Annual Capital Replacement Fund Contribution
Costs: $20,531
Wastewater Treatment System
Treatment Linear Assets (Outfall and
Yard Piping, Manholes and Other) $3,085,000 75 1.3% $41,000
Treatment Structures (Concrete
Chambers, etc.) $205,000 50 2.0% $4,000
Treatment Equipment (Mechanical /
Electrical, etc.) $1,245,000 20 5.0% $62,000
Subtotal $4,535,000 ‐ ‐ $107,000
Construction Contingency (Subtotal x 25%): $27,000
Engineering (Subtotal x 12%): $13,000
Wastewater Treatment System Annual Capital Replacement Fund Contribution Costs: $147,000
Total Wastewater Interception & Treatment Annual Capital Replacement
Fund Contribution Costs: $167,531
HEJV New Victoria Wastewater System Pre‐Design Summary Report 14
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 3 stations)
Pump Station Infrastructure (controls, pumps, etc.) $513,000
Backup Power Generation (only required for 2 stations) $96,000
Engineering (12%) $73,000
Contingency (25%) $152,000
Total $834,000
Collection System Asset Condition Assessment Program
Condition Assessment of Manholes based on 87 MHs $33,000
Condition Assessment of Sewer Mains based on 1.5 kms of
infrastructure $29,000
Total $62,000
Sewer Separation Measures
Separation based on 7.4 kms of sewer @ $45,000/km $333,000
Engineering (10%) $33,000
Contingency (25%) $83,000
Total $449,000
Total Estimated Existing Collection System Upgrade and
Assessment Costs $1,345,000
HEJV New Victoria Wastewater System Pre‐Design Summary Report 15
CHAPTER 7 PROJECT IMPLEMENTATION TIMELINE
7.1 Implementation Schedule
Figure 1 provides a tentative schedule for implementation of wastewater system upgrades for New
Victoria, including proposed wastewater interception and treatment infrastructure as well as
upgrades to and assessment of the existing collection system.
For the Low Risk systems such as New Victoria, it is expected that implementation of proposed
upgrades will proceed on a staggered basis over the next 20 years as dictated by funding availability.
As each of these systems have the same target deadline, the prioritization will likely depend on not
only the availability of funding but also external factors. As the prioritization of the low risk systems
is not currently known, 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, in Year 1, asset condition assessments and investigations
to locate sources of extraneous water entering the system would be carried out. The two subsequent
years are allotted for design/construction of recommended upgrades, however, it is conceivable that
this could be completed in one year, depending on the scope of work required. It is proposed that,
during the following year, a follow‐up wastewater flow metering program would be carried out to
confirm design flows for new infrastructure and gauge the effect of upgrades to the existing collection
system. The subsequent four years after the follow‐up flow metering program have been allotted to
carry out design/construction of the new interception and treatment system. However, it is
conceivable that this work could be completed within three (3) years. This results in a tentative
implementation schedule that covers an eight (8) year timeline, which as noted above could be
compressed to six (6) years to align with typical funding programs for major infrastructure.
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:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
Schedule:
Cash Flow:
9 Carry out tendering, construction, commissioning and initial systems operations for proposed
wastewater treatment infrastructure $6,195,150
7 Carry out tendering, construction, commissioning and initial systems operations for proposed
wastewater interception infrastructure $1,125,120
8 Carry out detailed design for proposed wastewater treatment infrastructure
$217,600
5 Carry out tendering, construction and commissioning for recommended upgrades to the existing
collection system $1,240,600
6 Carry out detailed design for proposed wastewater interception infrastructure
$28,800
3 Carry out Sewer Separation Investigation Study to locate sources of extraneous water entering the
collection system $15,000
4 Carry out detailed design for recommended upgrades to the existing collection system based on
previous assessments $42,400
1 Carry out asset condition assessment of all manholes in the existing collection system
$33,000
2 Carry out video inspection and assessment of selected sanitary sewers in the existing collection system
$29,000
Figure 1 ‐ Project Implementation Schedule New Victoria Wastewater System
Year:1234
HEJV New Victoria Wastewater System Pre‐Design Summary Report Appendices
APPENDIX A
New Victoria Collection System
Pre‐Design Brief
187116 ● Final Brief ● April 2020
Environmental Risk Assessments & Preliminary
Design of Seven Future Wastewater Treatment
Systems in CBRM
New Victoria Collection System Pre-Design Brief
Prepared by: HEJVPrepared for: CBRM
March 2020
March 27, 2020
275 Charlotte Street
Sydney, Nova Scotia
Canada
B1P 1C6
Tel: 902-562-9880
Fax: 902-562-9890
_________________
NEW VICTORIA COLLECTION SYSTEM PRE DESIGN BRIEF FINAL SUBMISSION REV2/ek
ED: 20/04/2020 10:54:00/PD: 20/04/2020 15:35:00
April 20, 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 – New Victoria 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 station that will form
the proposed wastewater collection for the Community of New Victoria. The
proposed system will convey sewer to/from a future Wastewater Treatment
Facility that will be located north of Daley Road. The Brief also outlines the
design requirements and standards for the required collection system
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 New Victoria Collection System Pre-Design Brief i
Contents
CHAPTER 1 Introduction & Background ........................................................................................... 1
1.1 Introduction ................................................................................................................... 1
1.2 System Background ........................................................................................................ 1
CHAPTER 2 Design Parameters & Standards .................................................................................... 3
2.1 General Overview ........................................................................................................... 3
2.2 Design Standards ............................................................................................................ 3
CHAPTER 3 Wastewater Interceptor Pre- Design ............................................................................. 5
3.1 General Overview ........................................................................................................... 5
3.2 Design Flows .................................................................................................................. 5
3.2.1 Theoretical Flow ................................................................................................. 6
3.2.2 Observed Flow .................................................................................................... 7
3.2.3 Flow Conclusions & Recommendations ............................................................... 8
3.2.4 Wet Weather Conditions Assessment ................................................................. 8
3.3 Interceptor System ......................................................................................................... 8
3.4 Pumping Stations ........................................................................................................... 9
3.4.1 Pumping Design Capacity .................................................................................. 10
3.4.2 Safety Features ................................................................................................. 10
3.4.3 Wetwell ............................................................................................................ 10
3.4.4 Station Piping.................................................................................................... 11
3.4.5 Equipment Access ............................................................................................. 11
3.4.6 Emergency Power ............................................................................................. 11
3.4.7 Controls ............................................................................................................ 11
3.4.8 Security ............................................................................................................ 12
CHAPTER 4 Existing Collection System Upgrades ........................................................................... 13
4.1 Sewage Pump Station Upgrades ................................................................................... 13
4.2 Asset Condition Assessment Program ........................................................................... 13
4.3 Sewer Separation Measures ......................................................................................... 13
CHAPTER 5 Pipe Material Selection and Design ............................................................................. 14
5.1 Pipe Material ................................................................................................................ 14
CHAPTER 6 Land and Easement Requirements .............................................................................. 15
6.1 Pump Station Site ......................................................................................................... 15
6.2 WWTP Site ................................................................................................................... 16
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief ii
6.3 Linear Infrastructure ..................................................................................................... 16
CHAPTER 7 Site Specific Constraints ............................................................................................... 17
7.1 Construction Constraints .............................................................................................. 17
7.2 Environmental Constraints ........................................................................................... 17
7.3 Access Requirements.................................................................................................... 17
7.4 Power Supply Requirements ......................................................................................... 17
CHAPTER 8 Opinion of Probable Costs ........................................................................................... 18
8.1 Opinion of Probable Construction Costs – New Wastewater Collection Infrastructure .. 18
8.2 Opinion of Operational Costs ........................................................................................ 18
8.3 Opinion of Existing Collection System Upgrades and Assessment Costs ........................ 19
8.4 Opinion of Annual Capital Replacement Fund Contributions ......................................... 20
CHAPTER 9 References ................................................................................................................... 21
Tables
Table 2-1 Sewer Design Criteria ............................................................................................... 3
Table 2-2 Pumping Station Design Criteria ............................................................................... 4
Table 3-1 Theoretical Flow Summary ....................................................................................... 7
Table 3-2 Design Flow for Pump Station ................................................................................... 7
Table 3-3 Flow Monitoring Location Summary ......................................................................... 7
Table 3-4 Average Dry Weather and Design Flows Results ....................................................... 8
Table 3-5 Observed Flows during Rainfall Events...................................................................... 8
Table 3-6 Pump Station Summary .......................................................................................... 10
Table 5-1 Comparison of Pipe Materials ................................................................................. 14
Table 6-1 Pump Station Land Acquisition Details .................................................................... 15
Table 6-2 WWTP Land Acquisition Details .............................................................................. 16
Table 6-3 Linear Infrastructure Land Acquisition Details ......................................................... 16
Table 8-1 Cost Breakdown Operations and Maintenance Costs .............................................. 18
Table 8-2 Estimated Existing Collection System Upgrade and Assessment Costs..................... 20
Table 8-3 Estimated Annual Capital Replacement Fund Contributions.................................... 20
Appendices
Appendix A –Drawings
Appendix B – Flow Master Reports
Appendix C – Opinion of Probable Design & Construction Costs
Harbour Engineering Joint Venture New Victoria 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; and,
®Estimation of capital and operations costs for recommended wastewater components.
This document relates to the interceptors, local sewers, combined sewer overflow and pumping
station that will form the wastewater interceptor system for the proposed WWTP in the community
of New Victoria. 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 New Victoria will be provided in a separate Design Brief.
1.2 System Background
Sewage for the community of New Victoria is conveyed to a single pipe outfall at the western end of
Daley Road. A 200mm diameter outfall extends 120m beyond the existing bank with a top of pipe
elevation set for 1 m below the low water level. A combination of gravity and pumped systems are
used in the existing New Victoria sewer collection system. The pumped systems in New Victoria
include three pump stations and a series of E-One Pumping systems. Location and details of each
pumping system follow:
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 2
®Highway 28 pump station – located on Highway 28, 40m west of Lameys Lane
o Installed in 1995;
o Conveys flow to a high point on Highway 28;
o Submersible station with 2 – 20hp pumps;
o No emergency power;
o Has an emergency overflow; and,
o Forcemain is 100mm in diameter.
®Browns Road – located near the intersection of Browns Road and Browns Road Extension
o Installed in 1996;
o Conveys flow up gradient to Highway 28;
o Submersible station with 2 – 20hp pumps;
o No emergency power;
o Has an emergency overflow; and,
o Forcemain is 100mm in diameter.
®New Waterford WTP – located at the New Waterford Water Treatment Plant
o Installed in 2007;
o Conveys flow to a high point on Daley Road (west of New Waterford Lake Road) ;
o Submersible station with 2 – 20hp pumps;
o Has emergency power;
o Forcemain is 100mm in diameter.
®E-One pumping systems have been employed in the sewer shed at several locations
including:
o New Waterford Lake Road;
o Daley Road;
o Browns Road Extension; and,
o Burkes Road Extension.
A drawing of the existing New Victoria sewer system is located in Appendix A for reference.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 3
CHAPTER 2 DESIGN PARAMETERS &STANDARDS
2.1 General Overview
The development of a 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 has developed the preliminary design of the interceptor sewer to meet and
exceed these industry standards.
2.2 Design Standards
The design of the interceptor system 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 to the Peak
Rate for the sewershed. See
discussion Section 3.2.
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
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 4
Description Unit Design Criteria Source Comments
Gravitypipe minimum
design flow velocity m/s 0.6 ACWGM
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 New Victoria Collection System Pre-Design Brief 5
CHAPTER 3 WASTEWATER INTERCEPTOR PRE-DESIGN
3.1 General Overview
A drawing of the existing New Victoria collection system has been included in Appendix A. The
drawing was created using background data collected from various sources to depict the layout of
the existing gravity network.
The proposed wastewater interceptor system for New Victoria will include a new gravity interceptor
on Daley Road that will redirect flow, 315m to the north to the proposed WWTP location. A small
sewage pump station will be required near the existing outfall to collect the remaining 22 homes
that lie below the connection point of the gravity interceptor. The pump station will convey flow
from the lower end of Daley Road to the interceptor sewer.
The outlet of the WWTP has been designed to utilize the existing outfall at the bottom end of Daley
Road. There are substantial savings to CBRM by utilizing the existing outfall which greatly outweighs
the inclusion of the gravity network between the proposed WWTP and the existing sanitary sewer
on Daley Road.
For this Pre-Design Brief, HEJV has compiled a preliminary plan and profile drawing of the proposed
linear infrastructure. The locations of the pump station, outfall and WWTP 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 New Victoria
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.
It is anticipated that the future WWTP for the community will be a stabilization pond with an
engineered wetland. Since the flow is being conveyed to a stabilization pond by gravity, it makes
sense to intercept all of the peak flow and divert it to the WWTP. The stabilization pond should be
sized for the average daily flow in the community regardless of the intercepted flow rate.
Intercepting the peak flow will end raw sewage being directly discharged at the existing New
Victoria Outfall. The stabilization pond with an engineered wet land, will offer some level of
treatment to all flows directed to the WWTP versus constructing an overflow chamber before the
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 6
WWTP based on an ADWF multiplier. Periods of higher flows, will cause the retention time in the
pond to decrease, however, discharged flows would have been already retained in the pond for
some time (partially treated) before release.
The pump station that is proposed for the lower end of Daley Road, should also be designed to
accommodate peak flows. Therefore the proposed interceptor sewer system for New Victoria will
not use combined sewer overflow (CSO) chambers to limit the flow to the proposed WWTP, and all
flows will be directed to the WWTP for treatment, prior to discharge into the Atlantic Ocean.
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. The peak
design flow was calculated using the following equation (1):
ܳ(݀)=ܲݍܯ
86.4 +ܫܣ (1)
Where:
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 contributing sewershed was estimated to be 52
ha. The peaking factor used in Equation 1 was determined using the Harman Formula (2) shown
below:
Harman 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.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 7
Table 3-1 Theoretical Flow Summary
Station Estimated Area
(ha)
Estimated
Population1 ADWF2 (l/s)Peak Design Flow3
(l/s)
New Victoria 74 673 2.65 26.24
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)
The peak flow for the proposed pump station was determined in a similar manner. Results of the
calculations for the pump station flows are presented below in Table 3-2.
Table 3-2 Design Flow for Pump Station
Estimate Drainage Area (ha)Estimated Population Harman Flow Factor Recommended Peak
Design Flow (l/s)
3.63 48 4.32 1.61
1 2016 Cape Breton Census from Statistics Canada
2 Estimated using ACWGM equation for peak domestic sewage flows (including extraneous flows and peaking
factor)
3.2.2 Observed Flow
One flow monitoring station was installed in New Victoria. The monitor was placed in a manhole at
the lower end of Daley Road. This location receives all of the flow from the New Victoria sewer shed.
A summary of the flow meter location and monitoring duration is provided in Table 3- 3.
Table 3-3 Flow Monitoring Location Summary
Station Northing Easting Monitoring Start-End Dates Days of Data
Daley Road 5124567.665 4604757.761 February 23-April 12, 2018 49
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.
Flow and rainfall 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 3-4, along with average and peak flow from raw monitored data.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 8
Table 3-4 Average Dry Weather and Design Flows Results
ADWF From SSOAP Model (l/s)Average Daily Observed Flow (l/s)Peak Daily Average Flow
(l/s)
6.9 8.13 13.24
3.2.3 Flow Conclusions & Recommendations
The recommended design flow for the Future WWTP is 28 l/s based on the calculated Peak Daily
Flow combining the intercepted flow on Daley Road and the pump station flows presented in Tables
3-1 and 3-2.
3.2.4 Wet Weather Conditions Assessment
To evaluate performance of the proposed interception system during wet weather conditions,
metered flows during rainfall events have also been considered. The results of the wet weather
flow assessment at the metered location is presented in Table 3-5. The calculated flows were
compared to the recommended design flow to indicate if sewer overflow/surcharge conditions
would be anticipated.
Table 3-5 Observed Flows during Rainfall Events
Monitoring Station
Minor Rainfall Event
(10-25 mm Daily Rainfall)
# of Events Daily Average
Flow (l/s)
Expected Overflow1
(Y/N)
Daley Road 5 11.5 N
1 Overflow expected when observed flow exceeds design flow
The results in Table 3-5 suggest that the interception system will be able to accommodate the wet
weather flows that were monitored during the flow gauging exercise.
3.3 Interceptor System
The proposed interceptor system for the New Victoria WWTP is presented on the plan and profile
drawing attached in Appendix A. The proposed interceptor system is made up of a gravity
interceptor sewer that will convey flow to the WWTP. A small pump station at the end of Daley Road
will convey the remainder of the flow from the sewershed back to the interceptor sewer.
The first step in laying out the interceptor sewer route was to determine the location of the future
WWTP that will serve the Community of New Victoria. To accomplish this, the type of treatment
process needed to be considered and the location of the plant needed to be confirmed. Initially
HEJV reviewed an option to convey sewage from New Victoria to the future New Waterford WWTP.
This interceptor system was compared to the initial costs of developing a stabilization pond with an
engineered wetland in the community of New Victoria. HEJV’s high level review concluded that the
costs of pumping the New Victoria sewage to New Waterford outweighed that of treating the
sewage directly in New Victoria. HEJV reviewed locations for the stabilization pond/engineered wet
land near the Daley Road outfall. The proposed location illustrated on the drawings located in
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 9
Appendix A was selected due to its proximity to the existing outfall, ease to which sewer could be
conveyed to the location and that the location met the 150m separation distance for isolated
human habitation as required by ACWGM.
With the WWTP location selected, HEJV laid out the interceptor sewer. The major elements of the
interceptor system include:
®A 300mm diameter interceptor sewer collects flow from Daley Road and conveys it 315m
northward to the proposed WWTP site.
®The remaining 22 homes that are located below the gravity interceptor connection will still
utilize the existing 200mm diameter sewer on Daley Road.
®A small pump station LS-NV1 will be installed near the end of Daley Road to pump the
remaining sewage from Daley Road to the gravity interceptor sewer.
®A 200mm diameter gravity main has been shown as the outlet to the WWTP, connecting
back to the existing New Victoria Outfall.
Flow Master reports for the proposed linear infrastructure, have been included in Appendix B.
An alternative that could be considered during the detailed design of the project would be the
inclusion of low pressure pumping systems. Homes that would be directed to the proposed lift
station could be serviced by a low pressure pumping system. This alternative has the potential to
provide a capital and operating cost savings. The downside to this alterative and why HEJV didn’t
present it at this time as the preferred option is that the homes are currently serviced by gravity
sewer. Each home would need an individual system which would cause a disturbance to each
private parcel of land. It is HEJV’s opinion that these systems work great in new sanitary sewer
developments, but would be a tougher sell to home owners that are currently serviced by gravity
sewer.
3.4 Pumping Stations
As discussed above, one new pumping station will be required in the proposed New Victoria
interceptor system to convey wastewater to the proposed WWTP. The pump station should be
equipped with non-clog submersible sewage pumps with an underground wetwell and valve
chamber. Due to the size of the station, HEJV recommends that a buried valve chamber be used for
this installation instead of an above ground installation that would be housed in a pump station
building. The cost to provide a pump station building at this location greatly outweighs the pros for
its inclusion. The electrical, control, and instrumentation systems will be contained in a common
control panel, located in the near vicinity of the wetwell. 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 to protect the pipe against unwanted surge
forces. A standard pump station schematic has been presented in Appendix A for illustrative
purposes.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 10
3.4.1 Pumping Design Capacity
The pump station is designed to pump the intercepted flows defined in Section 3.2.3 (1.61 l/s) with
one pump out of service. All pumps should 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.
3.4.1.1 PUMP STATION
The New Victoria pump station will convey flow to the proposed gravity interceptor sewer on Daley
Road, at which point the flows will be conveyed by gravity to the proposed stabilization
pond/engineered wet land. The pump station will be a duplex station, with one duty and one
standby pump. These pumps should have a capacity of 2 l/s, with a TDH of 30.8 m.
3.4.1.2 PUMP STATION SUMMARY
Table 3-6 Pump Station Summary
Pumping Station LS #1
Duty Pumps 1
Standby Pumps 1
ADWF (L/s)0.2
Interception Design Flow (L/s)
(peak flow rate)1.61
Pump Capacity
(L/s, each pump)2.0
Forcemain Diameter (mm)50
TDH (m) at Maximum Design Flow 30.8
Velocity (1 pump running) m/s 1.00
Approximate power requirement (each pump) kW 1.5
3.4.2 Safety Features
The station should report alarm conditions to the CBRM SCADA network. The station 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.
3.4.3 Wetwell
The wetwell should be constructed with a benched floor to promote self-cleansing and to minimize
any potential dead spots.
The size of the 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.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 11
The operating wetwell volumes for the pumping station should be based on alternating pump starts
between available pumps while reducing retention times to avoid resultant odours from septic
conditions.
Based on the conditions discussed above for sizing the wetwell, at this time HEJV recommends a
circular precast unit, with a diameter of 1.5 m and an overall depth of 3.3 m. This recommendation
assumes that the incoming gravity sewer would be 2.0 m below finished grade.
3.4.4 Station Piping
Pump station internal piping should be ductile iron class 350 with coal tar epoxy lining or stainless
steel with a diameter of 50mm. 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 should be included on the discharge header to monitor flows.
3.4.5 Equipment Access
Pump installation and removal 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, a weather-tight enclosure should be provided to
protect the davit when it is not in use.
All valves and flow monitoring equipment should be located in a common below grade valve
chamber. This valve chamber should be weather-tight, and would be complete with a drain to
remove any intruding water.
3.4.6 Emergency Power
The pump station 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. The generator
should also be provided with an exterior weathertight enclosure.
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.
3.4.7 Controls
All equipment should be controlled through a local NEMA 4X rated control panel. The local control
panel would be a custom panel designed to be integrated into the CBRM SCADA network. The panel
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 12
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
®Low fuel level
®Pump or generator fault
®Generator operation
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.
3.4.8 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 New Victoria Collection System Pre-Design Brief 13
CHAPTER 4 EXISTING COLLECTION SYSTEM UPGRADES
4.1 Sewage Pump Station Upgrades
HEJV has reviewed the existing New Victoria Collection System for potential upgrades to the existing
sewage pumping stations. There are currently three pump stations in the community of New
Victoria. The age of the existing stations range between 12 to 24 years old. The New Victoria WWTP
has been classified as a low priority system and has an implementation deadline of 2040.
Considering that 2040 is 21 years in the future, plans should be made to upgrade each of these
stations as part of the interception work to be completed in the community. Due to their age, the
necessity to upgrade these stations may occur prior to the implementation of the interceptor sewer
project. Therefore, 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 New Victoria 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 a sewer separation investigation program for New Victoria. 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.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 14
CHAPTER 5 PIPE MATERIAL 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
·Fittings are susceptible to corrosion
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 material selection for the gravity sewer
and forcemain piping for the New Victoria interceptor sewer be PVC.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 15
CHAPTER 6 LAND AND EASEMENT REQUIREMENTS
HEJV has reviewed the requirements for land acquisition and easements. The location for the future
WWTP for the community of New Victoria has been proposed to be located on privately owned
land, north of Daley Road. In addition to the land requirement for the WWTP site, the interceptor
sewer and outlet to the WWTP will cross several private parcels of land. The pump station will also
require the purchase of several pieces of private property to the north of Daley Road. There are
many small vacant parcels of land on the north side of Daley Road owned by one individual. The
lands that are being proposed for purchase fall outside of the area that the owner has developed for
their own dwelling and out buildings. Lands that the current owner utilizes (horse track), have been
shown as lands that will require an easement to construct the proposed works. HEJV considers
easements to be an acceptable option to both CBRM and the residential land owner for the
construction and maintenance of the interceptor linear infrastructure.
6.1 Pump Station Site
HEJV proposes that the land parcel for the pump station site be purchased due to the development
being a permanent structure requiring regular access from CBRM staff.
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, and whether or not HEJV recommends purchasing the entire lot. The
development of the pump station has been shown as a 15mx30m development. Due to the size of
the lots, it makes more sense to purchase the entire lots from the existing land owner, versus
negotiating pieces that would considerably limit the development on the remaining site. Please
note, as illustrated on the Sheet 2 in Appendix A, the pump station site has been shown on four
parcels of land. Again, these four parcels of land have the same owner, who owns a considerable
portion of land on the north side of Daley Road.
Table 6-1 Pump Station Land Acquisition Details
PID Property Owner Assessed Value Description Purchase Entire Lot
(Y/N)
15516586 Melvin J Cormier unknown PS Site Y
15516594 Melvin J Cormier unknown PS Site Y
15516602 Melvin J Cormier unknown PS Site Y
15516651 Melvin J Cormier unknown PS Site Y
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 16
6.2 WWTP Site
As discussed in Section 3.3, the WWTP will be located on a privately owned land parcel north of
Daley Road. Due to the size of the parcel that is being proposed for development, HEJV recommends
only purchasing a portion of the existing parcel, such that construction of the WWTP can be
facilitated, while leaving a large track of land for the existing owners. The proposed layout provides
the 150m separation distance for isolated human habitation as required by ACWGM. Presented
below in Table 6-2 are some of the pertinent details of the parcels of land required to build the
WWTP.
Table 6-2 WWTP Land Acquisition Details
PID Property Owner Assessed
Value Description Size Required
(m2)
Purchase Entire
Lot (Y/N)
15267057 Rodney Andrew
Young $50,800 WWTP Site 95,700 N
6.3 Linear Infrastructure
The installation of linear infrastructure will require several easements. The interceptor sewer
crosses several privately owned parcels of land (outside of those being purchased for the WWTP
site). The outlet from the WWTP site will also cross several pieces of privately owned parcels of land.
The majority of the land has been shown as requiring an easement to permit the construction of the
work. There are several smaller parcels that have been shown to be purchased. Due to the size of
the existing lots, it makes sense to negotiate the purchase of the entire lot. The remaining linear
infrastructure will be installed within public right-of-way’s, CBRM land and undeveloped adjacent
street parcels. Details on the required land acquisitions are as follows:
Table 6-3 Linear Infrastructure Land Acquisition Details
PID Property Owner Assessed
Value Description Easement Size
Required
Purchase Entire
Lot (Y/N)
15518798 Pauline McDonald $5,100
Gravity
Interceptor
and Outlet
10m (Construction)
6m (Final)
X 135m length
N
15518418 Pauline McDonald $2,000 WWTP Site
10m (Construction)
6m (Final)
X 62m length
N
15267107
Keith Jackson,
Heather Grant,
Earl Keith Jackson
$97,700 WWTP Site
10m (Construction)
6m (Final)
X 64m length
N
15267099 Francis James JR
Fahey $143,700 WWTP Site
10m (Construction)
6m (Final)
X 67m length
N
15319155 Carol Sheppard Unknown Gravity
Interceptor N/A Y
15517907 Melvin J Cormier Unknown Outlet
10m (Construction)
6m (Final)
X 35m length
N
15516693 Melvin J Cormier Unknown Outlet N/A Y
15516701 Melvin J Cormier Unknown Outlet N/A Y
15516719 Melvin J Cormier Unknown Outlet N/A Y
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 17
CHAPTER 7 SITE SPECIFIC CONSTRAINTS
During the preliminary design of the interceptor system, HEJV has reviewed the site for the pump
station and pipe routing for potential constraints. HEJV reviewed construction constraints,
environmental 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 WWTP will
need to be constructed, prior to any of the raw discharge being diverted to the new interceptor
system.
7.2 Environmental Constraints
The proposed outlet routing has been shown to keep an approximate distance of 50m to the
existing edge of bank. This distance was selected to provide a buffer for erosion concerns. HEJV is
knowledgeable of erosion concerns in the New Victoria Area. At the nearby lighthouse,
approximately 5m of embankment has been lost due to erosion in the last 10 years.
7.3 Access Requirements
Access to the pump station site should be fairly straight forward, as it is adjacent to Daley Road. A
driveway off of the street will need to be extended as well as an entrance gate in the fenced
perimeter.
The WWTP location is somewhat remote and will require an access road to be constructed along the
proposed interceptor sewer pipe route. Access requirements for the WWTP site will be further
detailed in the New Victoria WWTP Pre-Design Brief.
7.4 Power Supply Requirements
The pump station equipment being proposed by HEJV only requires single phase power, which is
already readily available at the pump station site.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 18
CHAPTER 8 OPINION OF PROBABLE COSTS
8.1 Opinion of Probable Construction Costs – New Wastewater Collection
Infrastructure
An Opinion of Probable Design & Construction Costs for new 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 and pump station required to collect and
convey the sanitary sewer in New Victoria 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. For the PID’s listed in Tables 6-1 and 6-
3 with an unknown assessment value, HEJV compared neighbouring undeveloped lots and
attributed a per square meter for the land based on this comparison. The Opinion of Probable
Design & Construction Costs for the interceptor sewer infrastructure for New Victoria is $1,153,920.
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 as detailed in Table 8-1 includes general pump
station maintenance costs, general linear maintenance costs, employee operation and maintenance
costs, electrical operational costs and backup generator operation and maintenance costs.
Table 8-1 Cost Breakdown Operations and Maintenance Costs
Item Cost
General Pump Station Maintenance Cost $3,500/yr
General Linear Maintenance Cost $500/yr
Employee O&M Cost $3,500/yr
Electrical Operational Cost $1,000/yr
Backup Generator O&M Cost $1,100/yr
Total Annual O&M Costs $9,600.00/yr
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 19
The general station maintenance cost presented above includes pump repairs (impellers, bearings,
seals), electrical repairs and instrumentation repairs and servicing.
The general linear maintenance cost for the interceptor system has been estimated to be $500 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 station requires an average of 100 hours of effort per submersible
pump station per year.
For the electrical operation cost, 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 sewage pumping stations, the opinion of probable cost includes a full retrofit of each of the
existing stations 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. For the purposes of
this report, HEJV has assumed that each station will require an upgrade. The pump station upgrade
at the New Waterford Treatment Plant site would not require backup power generation as the
existing station is connected to the backup power at the New Waterford Water Treatment Plant.
Pump 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.
Estimates of costs for upgrades to and assessment of the existing collection system as outlines in
Table 8-2 are considered to be Class ‘D’, accurate to within plus or minus 45%.
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 20
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.
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)$432,260 75 1.3%$5,619
Pump Station Structures
(Concrete Chambers, etc.)$157,355 50 2.0%$3,147
Pump Station Equipment
(Mechanical / Electrical)$128,745 20 5.0%$6,437
Subtotal $718,360 --$15,203
Contingency Allowance (Subtotal x 25%):$3,801
Engineering (Subtotal x 10%):$1,520
Opinion of Probable Annual Capital Replacement Fund Contribution:$20,524
Note:
Annual contribuƟons do not account for annual inflaƟon.
Item Cost
Sewage Pump Station Upgrades (for 3 stations)
Pump Station Infrastructure (controls, pumps, etc.)$513,000
Backup Power Generation (only required for 2 stations)$96,000
Engineering (12%)$73,000
Contingency (25%)$152,000
Total $834,000
Collection System Asset Condition Assessment Program
Condition Assessment of Manholes based on 87MH’s $33,000
Condition Assessment of Sewer Mains based on 1.5km’s of infrastructure $29,000
Total $62,000
Sewer Separation Measures
Separation based on 7.4km’s of sewer @ $45,000/km $333,000
Engineering (10%)$33,000
Contingency (25%)$83,000
Total $449,000
Total Estimated Existing Collection System Upgrade and Assessment Costs $1,345,000
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 21
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 New Victoria Collection System Pre-Design Brief 22
APPENDIX A
Drawings
DALEY R
D
.
NE
W
W
A
T
E
R
F
O
R
D
H
I
G
H
W
A
Y
DALEY R
D
.
BR
O
W
N
S
R
O
A
D
E
X
T
E
N
S
I
O
N
BROWN
S
R
O
A
D
B
U
R
K
E
S
R
O
A
D
NE
W
W
A
T
E
R
F
O
R
D
L
A
K
E
R
D
.
EXISTING OUTFALL
(NV#1)
1
ENVIRONMENTAL RISK ASSESSMENTS
& PRELIMINARY DESIGN
JRS
JRS TAB
TAB 18-7116
1:5000
NOVEMBER 2019
HA
R
B
O
U
R
E
N
G
I
N
E
E
R
I
N
G
J
O
I
N
T
V
E
N
T
U
R
E
,
2
7
5
C
H
A
R
L
O
T
T
E
S
T
R
E
E
T
,
S
Y
D
N
E
Y
,
N
S
,
B
1
P
1
C
6
A
B
C
ISSUED FOR REVIEW
ISSUED FOR DRAFT DESIGN BRIEF
RE-ISSUED FOR FINAL DESIGN BRIEF
02/27/18
10/15/18
11/12/19
JRS
JRS
JRS NEW VICTORIA
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
502/5
0
3
504/5
0
5
15267057
(RODNEY ANDREW YOUNG)
15267099
(FRANCIS JAMES JR FAHEY)
15267107
(KEITH JACKSON, HEATHER
GRANT, EARL KEITH JACKSON)
15518418
(PAULINE MCDONALD)
15518798
(PAULINE MCDONALD)
15697774
(CBRM)
EXISTING OUTFALL (NV#1)
LS-NV1
200m
m
Ø
PROPOSED 200mmØ GRAVITY SEWER
OUTLINE OF PROPERTY
REQUIRING ACQUISITION
OUTLINE OF PROPERTY
REQUIRING AN EASEMENT
DALEY
R
D
.
DALEY
R
D
.
NE
W
W
A
T
E
R
F
O
R
D
H
I
G
H
W
A
Y
PROPOSED 50mmØ FORCEMAIN
PROPOSED 300mmØ GRAVITY SEWER
50mmØ
3
0
0
m
m
Ø
15516487, 15516495,15516503
(MELVIN J CORMIER)
15516511, 15516529, 15516537
15516586, 15516594,
(MELVIN J CORMIER)
15516602, 15516651
(MELVIN J CORMIER)
15516693, 15516701, 15516719
15517907
(MELVIN J CORMIER)
15319155
(CAROL SHEPPARD)
PROPOSED
WWTP LOCATION
2
ENVIRONMENTAL RISK ASSESSMENTS
& PRELIMINARY DESIGN
JRS
JRS TAB
TAB 18-7116
AS NOTED
NOVEMBER 2019
HA
R
B
O
U
R
E
N
G
I
N
E
E
R
I
N
G
J
O
I
N
T
V
E
N
T
U
R
E
,
2
7
5
C
H
A
R
L
O
T
T
E
S
T
R
E
E
T
,
S
Y
D
N
E
Y
,
N
S
,
B
1
P
1
C
6
A
B
C
ISSUED FOR DRAFT REPORT
ISSUED FOR FINAL DESIGN BRIEF
RE-ISSUED FOR FINAL DESIGN BRIEF
10/15/18
03/04/19
11/12/19
JRS
JRS
JRS
NEW VICTORIA INTERCEPTOR
PLAN/PROFILE
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
INTERCEPTOR PROFILE
1:2500 (HOR.) 1:500 (VERT.)
OUTLET PROFILE
1:2500 (HOR.) 1:500 (VERT.)
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 23
APPENDIX B
Flow Master Reports
Harbour Engineering Joint Venture New Victoria Collection System Pre-Design Brief 24
APPENDIX C
Opinion of Probable Design & Construction
Costs
OPINION OF PROBABLE
COST, CLASS 'C'
Preliminary
Collection Project Manager:D. MacLean
and Interception Infrastructure Costs Only Est. by: J. Sheppard Checked by: D. McLean
New Victoria, NS PROJECT No.:187116 (Dillon)
182402.00 (CBCL)
UPDATED:April 20, 2020
NUMBER UNIT
Linear Infrastructure $432,620.00
200 mm Diameter PVC sewer 500 m $320.00 $160,000.00
300 mm Diameter PVC sewer 315 m $340.00 $107,100.00
50 mm Diameter PVC forcemain 460 m $125.00 $57,500.00
Precast Manhole 10 each $5,500.00 $55,000.00
Connection to Existing Main 3 each $8,000.00 $24,000.00
Closed Circuit Televsion Inspection 815 m $8.00 $6,520.00
Trench Excavation - Rock 250 m3 $60.00 $15,000.00
Trench Excavation - Unsuitable Material 250 m3 $10.00 $2,500.00
Replacement of Unsuitable with Site Material 125 m3 $10.00 $1,250.00
Replacement of Unsuitable with Pit Run Gravel 125 m3 $30.00 $3,750.00
Lift Station $286,100.00
Pump Station 1 L.S.$250,000.00 $250,000.00
Site Work 1 L.S.$35,000.00 $35,000.00
Mass Excavation - Rock 10 m3 $60.00 $600.00
MassExcavation - Unsuitable Material 10 m3 $10.00 $100.00
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
SUBTOTAL (Construction Cost)$718,720.00
Contingency Allowance (Subtotal x 25 %)$180,000.00
Engineering (Subtotal x 10 %)$72,000.00
Land Acquisition $183,200.00
OPINION OF PROBABLE COST (Including Contingency)$1,153,920.00
PREPARED FOR:
Cape Breton
Regional Municipality
THIS OPINION OF PROBABLE COSTS IS PRESENTED ON THE BASIS OF EXPERIENCE, QUALIFICATIONS, AND BEST JUDGEMENT. IT HAS BEEN PREPARED INACCORDANCE 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
March 27, 2020
HEJV New Victoria Wastewater System Pre‐Design Summary Report Appendices
APPENDIX B
New Victoria Treatment System
Pre‐Design Brief
182402.00 ● Final Brief ● April 2020
Environmental Risk Assessments & Preliminary
Design of Seven Future Wastewater Treatment
Systems in CBRM
New Victoria Wastewater Treatment Plant
Preliminary Design Brief
Prepared by:Prepared for:
March 2020
Final April 20, 2020 Darrin McLean Mike Abbott
Dave McKenna
Sarah Ensslin
Draft for Review August 6, 2019 Darrin McLean Mike Abbott
Dave McKenna
Sarah Ensslin
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 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.
182402.00
March 27, 2020
182402 RE 001 FINAL WWTP PREDESIGN NEW VICTORIA HS 202000420.DOCX/mk
ED: 20/04/2020 14:49:00/PD: 20/04/2020 14:49:00
April 20, 2020
Matt Viva, P.Eng.
Manager Wastewater Operations
Cape Breton Regional Municipality (CBRM)
320 Esplanade,
Sydney, NS, B1P 7B9
Dear Mr. Viva:
RE: New Victoria Wastewater Treatment Plant Preliminary Design
Enclosed, please find a copy of the Preliminary Design Brief for the New Victoria
Wastewater Treatment Plant (WWTP), for your review.
The report presents an evaluation of treatment process alternatives for the New
Victoria WWTP. It also presents a preliminary design based on the
recommended Aerated Lagoon 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:
Sarah Ensslin, P.Eng. Mike Abbott, P.Eng., M.Eng.
Process Engineer Manager Process Department
Direct: 902-421-7241 (Ext. 2238)
E-Mail: sensslin@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
CBCL Limited New Victoria WWTP Preliminary Design i
Contents
CHAPTER 1 Introduction .......................................................................................................... 3
1.1 Introduction .................................................................................................................. 3
1.2 Background ................................................................................................................... 3
1.3 Objectives ..................................................................................................................... 3
CHAPTER 2 Existing Conditions ................................................................................................ 4
2.1 Description of Existing Infrastructure ........................................................................... 4
2.2 Flow Characterization ................................................................................................... 4
2.3 Wastewater Quality Characteristics ............................................................................. 6
2.4 Wastewater Loading Analysis ....................................................................................... 6
CHAPTER 3 Basis of Design ...................................................................................................... 8
3.1 Service Area Population ................................................................................................ 8
3.2 Design Flows and Loads ................................................................................................ 8
3.2.1 Wastewater Temperature ................................................................................ 9
3.3 Effluent Requirements .................................................................................................. 9
3.4 Design Loads ............................................................................................................... 10
CHAPTER 4 Treatment Process Alternatives ........................................................................... 11
4.1 Preliminary Treatment ................................................................................................ 11
4.2 Secondary Treatment ................................................................................................. 11
4.2.1 Site-Specific Suitability .................................................................................... 12
4.2.2 Description of Candidate Processes for Secondary Treatment ...................... 13
4.3 Disinfection ................................................................................................................. 16
4.4 Sludge Management ................................................................................................... 17
4.5 Secondary Treatment Option Evaluation ................................................................... 17
4.5.1 Qualitative Evaluation Factors ........................................................................ 17
4.5.2 Recommended Secondary Treatment Process ............................................... 18
CHAPTER 5 Preliminary Design .............................................................................................. 19
5.1 Preliminary Design Drawings ...................................................................................... 19
5.2 Unit Process Descriptions ........................................................................................... 19
5.2.1 Preliminary Treatment .................................................................................... 19
5.2.2 Secondary Treatment ..................................................................................... 19
5.2.3 Disinfection ..................................................................................................... 21
5.2.4 Sludge Management ....................................................................................... 22
CBCL Limited New Victoria WWTP Preliminary Design ii
5.3 Facilities Description .................................................................................................. 22
5.3.1 Civil and Site Work .......................................................................................... 23
5.3.2 Architectural ................................................................................................... 23
5.3.3 Mechanical ...................................................................................................... 24
5.3.4 Electrical Service and Emergency Power ........................................................ 24
5.3.5 Lighting ........................................................................................................... 24
5.3.6 Instrumentation .............................................................................................. 25
5.4 Staffing Requirements ................................................................................................ 25
CHAPTER 6 Project Costs ....................................................................................................... 26
6.1 Opinion of Probable Capital Cost ................................................................................ 26
6.2 Opinion of Probable Operating and Life Cycle Cost .................................................... 26
6.3 Opinion of Annual Capital Replacement Fund Contributions ..................................... 28
CHAPTER 7 References .......................................................................................................... 29
Appendices
A Flow Data
B Environmental Risk Assessment
C Conceptual Plant Layout
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 3
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 New Victoria, 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 new 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 New Victoria, 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.
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.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 4
CHAPTER 2 EXISTING CONDITIONS
2.1 Description of Existing Infrastructure
The wastewater collection system in New Victoria consists of approximately 6.5 km of gravity sewer,
three lift stations, 3.7 km of force main, and numerous E-One systems. E-One systems are individual
home sewage pumping systems that discharge to a common pressure sewer. In some instances, the
flow is first discharged to a septic tank and the effluent from the septic tank is pumped. In other
instances, flow is pumped directly from the home.
One of the lift stations pumps residuals from the New Waterford Water Treatment Plant into the
sewer system. The residuals stream is high in aluminum, as well as other metals that are removed
during the treatment process (including iron and manganese). Three filters are backwashed per week
at a flow of 340 m³ (90,000 US gallons) per backwash.
All wastewater is ultimately discharged untreated to the Atlantic Ocean via a 200mm (8”) HDPE
outfall at the end of Daley Road. The outfall extends 120m from the last manhole with the top of
pipe situated 0.8m below low water level, according to the New Victoria Sewerage Record Drawings
completed by Vaughan Engineering in 1996.
2.2 Flow Characterization
A flow meter was installed in the sewer system from February 23 to May 1, 2018. Please note that
flow data for this report was gathered over a longer period of time than for the associated New
Victoria Collection System Pre-Design Brief. The meter location was just upstream of the discharge
point and encompasses the entire wastewater system. The flow meter data are shown in
Appendix A.
The data was analyzed and the results are provided in Table 2.1. Per capita flows are calculated
assuming a current population of 604 people, and areal flows are calculated using a total area of
74.5 ha.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 5
Table 2.1: Metered ADWF
Flow Category Metered Flow
(m³/day)
Per capita flow
(L/cap/day)
Areal Flow
(m³/ha/d)
Average Dry Weather Flow 596 987 8.0
Average Day Flow 840 1391 11.3
Maximum Month Flow 1053 1743 14.1
The Average Dry Weather Flow (ADWF) was defined as the average flow for the days that met the
following criteria:
• No rain recorded in the previous 24 hours;
• No more than 5 mm in the previous 48 hrs; and
• No more than 5mm per day, additional, in all previous days (e.g., no more than 10mm
altogether in the last 3 days).
The per capita measured ADWF is of 987 L/person/day. This is high for dry weather flow (compared
to a reference value of 340 L/person/day), and indicates moderate to significant influence of
extraneous flows from inflow and infiltration (I&I) during dry weather. Since all flow monitoring
took place in spring, it is likely that the true annual average value is somewhat lower than this;
however, since this collection system and treatment plant will be able to receive and treat all flows,
as discussed in the New Victoria Collection System Pre-Design Brief (Harbour Engineering Joint
Venture, 2019), the exact ADWF value is less important than for situations where this is not possible.
The Average Day Flow (ADF) was calculated using all available metered flow data, including rain
events. The Maximum Month Flow (MMF) was calculated as the maximum flow measured during a full
30 days (April 2–May 1, 2018).
The peak day flow (PDF) for the metering period is provided in Table 2.2, measured as the maximum
flow in a 24-hour period. The PDF of 2,783 m3/d occurred during a large rain event (50.8 mm
according to Sydney A rain gauge, or 79.1 mm according to Sydney CS rain gauge); however, it was
less than a 1 in 2 year rain event.
Table 2.2: Metered PDF
48hr Rainfall (mm) PDF (m3/d) PDF (L/p/d) PDF (m3/ha/d)
51 2,783 4,608 37.4
The peak hour flow was 179 m3/hr (49.7 L/s), as compared to an ADF of 840 m³/d. These flows were
metered after a 48-hour rainfall of 51 mm. In this sewershed, infiltration appears more significant
than inflow, although both are likely present, and flows per person are relatively high. Efforts
should be made to locate and minimize the source(s) of infiltration and inflow prior to detailed
design, in order to reduce the capital cost and size of the treatment plant.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 6
2.3 Wastewater Quality Characteristics
HEJV collected one untreated wastewater sample upstream of the outfall in 2018 and the results are
summarized in Table 2.3. For simplicity, only the parameters of relevance to the preliminary design
are included. Refer to the Environmental Risk Assessment (ERA) report located in Appendix B for the
complete analytical results.
Table 2.3: 2018 Wastewater Characterization Results
Parameter Units 23-Apr-18
Carbonaceous Biochemical Oxygen Demand (CBOD) mg/L 61
Total Kjeldahl Nitrogen (TKN) mg/L 6
Ammonia Nitrogen (as N) mg/L 2.3
Un-ionized ammonia mg/L 0.0089
pH – 7.15
Total Phosphorus (TP) mg/L 0.83
Total Suspended Solids (TSS) mg/L 40
E. coli MPN/ 100mL >240,000
Total Coliforms MPN/ 100mL >240,000
CBRM collected a number of untreated wastewater samples from 2014 through 2018 and the
results are summarized in Table 2.4. The TSS concentrations, in particular, are high, but this is likely
to be reflecting the solids from the New Waterford WTP.
Table 2.4: CBRM Wastewater Characterization Samples
Parameter Average Maximum Number of Samples
CBOD5 (mg/L) 51 190 54
TSS (mg/L) 204 1100 54
Total Ammonia (mg/L) 2.8 7.2 19
Unionized Ammonia (mg/L) 0.006 0.017 19
pH (unitless) 6.9 7.1 19
2.4 Wastewater Loading Analysis
The theoretical per person loading rates listed in Atlantic Canada Wastewater Guidelines Manual
(ACWGM) (ABL Environmental Consultants Limited, 2006) are 0.08 kg CBOD/person/day and 0.09 kg
TSS/person/day. The reference theoretical TKN loading rate of 0.0133 kg TKN/person/day is stated
in Wastewater Engineering: Treatment and Reuse (Metcalf & Eddy, Inc, 2003).
Loads were calculated from three samples with concurrent flow data available. The average value
for 2018 was also calculated based on the calculated average flow rate of the NV1 sewershed
(including all measured extraneous flows) and the average 2018 NV1 concentration data. These
values are shown in Table 2.5, below.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 7
Table 2.5: Calculated and Theoretical Loading Rates
Calculated Load CBOD (kg/cap/d) TSS (kg/cap/d) TKN (kg/cap/d)
March 23, 2018 (NV1) 0.03 0.05 –
April 5, 2018 (NV1) 0.04 0.04 –
April 23, 2018 (NV1) 0.10 0.06 0.009
Average 2018 (NV1) 0.07 0.28 –
Theoretical Loading 0.08 0.09 0.013
For CBOD and TKN, the theoretical loading rates appear to be reasonable for the current data. For
TSS, however, some of the calculated loading rates are higher than theoretical. This is also
supported in the historical data, where the ratio of TSS concentrations to CBOD concentrations
averages about 4, which is rather atypical. If theoretical loading rates applied for both constituents,
we would expect to see TSS concentrations that were, on average, only slightly higher than CBOD
concentrations. There is a known significant source of additional TSS from the residuals from the
New Waterford WTP.
For design loading conditions, the theoretical values were used for CBOD and TKN, and the average
2018 NV1 value was used for TSS. The high TSS loads may require more frequent than usual sludge
removal. The design loading rates are shown in Table 2.6, below.
Table 2.6: Design Loading Rates
Parameter Value
Population 604
CBOD (kg/cap/d) 0.08
TSS (kg/cap/d) 0.28
TKN (kg/cap/d) 0.013
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 8
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 service area population for New
Victoria was obtained based on the 2016 Census data from 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 New Victoria, the service area population was estimated to be 604 people in 283 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 pre-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.
As the target date for this WWTP is 2040, consideration should be given to re-evaluating the
population and wastewater flows if a significant amount of time has passed between completion of
the pre-design study and the project moving to the detailed design stage.
3.2 Design Flows and Loads
As discussed in the New Victoria Collection System Pre-Design Brief (Harbour Engineering Joint
Venture, 2019), all flows will be treated at the proposed WWTP. The resulting design flows, based
on the flow meter data which was summarized in Section 2.2, are shown in Table 3.1, below. They
are rounded for ease of use.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 9
Table 3.1: WWTP Design Flows
Parameter Value
Average Dry Weather Flow (m³/day) 600
Average Daily Flow (m³/day) 840
Maximum Monthly Flow (m³/day) 1,050
Peak Day Flow (m³/day) 2,800
Peak Hour Flow (m³/hr) 180
As the treatment system will likely be a land-based system (lagoon), the hydraulic retention time will
be sized for the maximum monthly flow and average loads at winter temperatures. The aeration
component (if applicable) will be sized for summer temperatures. Individual facility components
such as piping and the UV disinfection system may be sized for different peak flows as appropriate.
3.2.1 Wastewater Temperature
Design temperatures for winter and summer are assumed to be 0.5°C and 20°C, respectively.
Winter conditions will govern the process requirements for lagoon size owing to the observed high
flows and loads in combination with the coldest temperatures. Warm water temperatures during
summer will determine aeration system requirements such as blower size, headers, number of grids
and diffusers for the lagoons.
3.3 Effluent Requirements
The effluent requirements will include the federal Wastewater System Effluent Regulations (WSER)
limits, along with provincial effluent requirements determined by Nova Scotia Environment (NSE)
and presented in the future NSE Approval to Operate for the WWTP. An ERA which determined
effluent discharge objectives for parameters not included in the WSER is found in Appendix B).
The receiving water for the New Victoria WWTP is the Atlantic Ocean. 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.
Refer to Table 5.1 in the ERA attached in Appendix B for Effluent Discharge Objectives (EDOs)
determined by the ERA and for further information on the development of these values.
The effluent requirements are summarized in Table 3.2 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.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 10
Table 3.2: 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/ 100 mL) 540,980 NSE 200
3.4 Design Loads
The wastewater concentrations vary significantly as was shown in Sections 2.3 and 2.4. For design
purposes, we are going to use the calculated per person loads shown in Table 2.6. The maximum
month loads are assumed to be 1.2 times the average loads for all constituents. The resulting loads
are shown in Table 3.3, below.
Table 3.3: Design Loading Summary
Parameter Average Day Max. Month
Design Population 604
Flow (m3/day) 840 1,050
CBOD Load (kg/day) 48 58
TSS Load (kg/day) 169 203
TKN Load (kg/day) 8 10
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 11
CHAPTER 4 TREATMENT PROCESS ALTERNATIVES
Achieving the effluent criteria described in the preceding chapter requires the selection of an overall
wastewater treatment process that includes a secondary treatment process. Secondary treatment
processes are predominantly aerobic biological processes designed to convert the finely dispersed
and dissolved organic matter in 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. Preliminary treatment processes
are typically used in advance of secondary treatment processes 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.
Preliminary treatment requirements are dependent upon the secondary treatment technology that
is selected. For land-based treatment technologies, pre-treatment requirements can range from no
preliminary treatment, to a screen or grinder, to grit removal. The influent wastewater will be flow
in a proposed 200 mm gravity pipe from Daley Rd. Considerations for this site include that the New
Victoria WWTP will be a CBRM satellite facility so minimizing maintenance visits is desirable;
however, including a coarse bar screen would remove litter and other large, non-biodegradable
solids from the incoming flow. For this reason we have included a manually-raked coarse bar rack,
but it may be possible to operate without preliminary treatment, if preferred.
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
adsorption of organic material and to the atmosphere and/or artificial aeration for oxygen. A listing
of specific secondary treatment processes and the category to which they belong is presented in
Table 4.1.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 12
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 Bioreactor (MBR)
Attached Growth Rotating Biological Contactor (RBC)
Trickling Filter
Biological Activated Filter (BAF)
Moving Bed Bio-Reactor (MBBR)
Land-Based Stabilization Basin
Aerated Lagoon
Constructed Wetlands
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 will influence which of the available options are best suited for the
New Victoria WWTP are: effluent requirements, site conditions, cost effectiveness, and ease of
operation. Each of these items are discussed below.
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 land-based processes which may require a settling pond or
constructed wetland for additional polishing of the effluent.
4.2.1.2 SITE CONDITIONS
All of the land-based options require a significant amount of available land, with the stabilization
basin requiring a large amount of land and the aerated lagoon requiring a moderate amount of land.
Constructed wetlands usually require even more land than stabilization basins, and work best as a
polishing process. Based on a preliminary review, a stabilization basin may be restricted by the
setbacks and separation distances from neighbouring residents.
A location to the north of Daley Road and west of New Waterford Highway has been identified as
the preferred location of the New Victoria WWTP, since the existing outfall currently discharges in
this area. The site selection is described in the New Victoria Collection System Predesign Report.
HEJV recommends CBRM purchase the privately owned PID 15267057, and also a piece of the
following privately owned PIDs as required: 15267099, 15267107, and 15518418. This location has
areas that are remote from residential development, which as defined as being at least 150 m from
isolated human habitation as required by the ACWGM (ABL Environmental Consultants Limited,
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 13
2006). The location also provides adequate distance from neighboring property boundaries as
defined by ACWGM. ACWGM also requires a 75 m separation distance from the centreline of the
berm of a land-based process to the watercourse located on this site. The existing New Victoria
Sewer System and New Victoria Interceptor Plan/Profile Drawings in the New Victoria Collection
System Pre-Design Brief (Harbour Engineering Joint Venture, 2019) detail the proposed location of
the New Victoria WWTP.
4.2.1.3 COST EFFECTIVENESS
Of the processes listed in Table 4.1, many can be eliminated based on their cost effectiveness
compared to the other processes. The land-based treatment process options are generally the most
cost-effective to construct and operate provided the technology is appropriate for the size of the
plant and there is sufficient available land suitable for construction.
4.2.1.4 EASE OF OPERATION
The operational requirements of both aerated lagoons and stabilization basins are much less
involved than a mechanical treatment plant. Of the two land based processes, stabilization basins
require less maintenance and operations due to the absence of an aeration system and blowers.
4.2.2 Description of Candidate Processes for Secondary Treatment
Based on the preceding analysis, the following processes should be given further consideration:
• Stabilization Basin, and
• Aerated Lagoon.
Each of these processes is described below.
4.2.2.1 STABILIZATION BASIN
In stabilization basins, oxygen is supplied to the wastewater by algal respiration and directly from
the atmosphere, without mechanical aerators. Most of the oxygen from algal respiration is
produced near the surface, because the algae require sunlight. Diffusion of oxygen and mixing from
the wind are also highest near the surface. If a stabilization basin is shallow enough, it can be
aerobic throughout, but the most common type in this region is facultative. In a facultative
stabilization basin, the surface is aerobic, the middle has declining oxygen levels, and the bottom
layer is anaerobic, allowing for sludge digestion. Facultative stabilization basins are typically 1.5–
1.8 m deep, and have retention times in the range of 25 to 180 days, with 180 days being common
in Atlantic Canada. Only the facultative stabilization basin will be assessed (subsequently referred to
in this report as “Stabilization Basin”). Organic loading rates for areas with an average winter air
temperature of less than 0°C are typically in the range of 11–22 kg BOD5/ha/d. They have at least
two cells, while larger lagoons may have more cells to minimize short circuiting. Effluent suspended
solids can be seasonally high due to algae, but stabilization basins may be followed by a constructed
wetland for effluent polishing.
The stabilization basin is sized using the formula from ACWGM (ABL Environmental Consultants
Limited, 2006) shown below in Equation 4.1 and Equation 4.2, where Le is the effluent CBOD
concentration (mg/L), Li is the influent CBOD concentration (mg/L), KT is the reaction rate constant
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 14
at temperature T (°C), T is the reaction temperature (°C), t is the total retention time (days), n is the
number of cells in series, and θ is a temperature activity coefficient assumed to be 1.036. The
resulting volume is targeting an effluent concentration around 20 mg/L in winter, and includes
allowances for sludge storage and ice formation.
Equation 4.1
𝐿 =𝐿
ቀ1+𝐾்𝑡𝑛ቁ
Equation 4.2
𝐾் =𝐾ଶ𝜃ሺ்ିଶ ሻ
A stabilization basin conceptual option has been developed based on the projected design flow and
loads, as well as on the design parameters listed in Table 4.2.
Table 4.2: Stabilization Basin Design Parameters
Parameter Value
Average Day Flow (m3/d) 840
Number of Cells 2
Reaction Rate Constant K₂₀ (/d) 0.055
Total Volume (m³) 40,000
Retention Time at Average Flow (days) 48
Water Depth + Freeboard (m) 1.5+1
Side Slope 3:1
Area (at waterline, m²) 28,500 (2.85 ha)
Cell dimensions, per cell (at waterline, L x W, m) 72 x 198
Organic Loading Rate 16.8 kg BOD5/ha/d
Sludge allowance (m) 0.15
Ice allowance (m) 0.15
Wetlands can be used to provide additional removal of TSS. Constructed wetlands are inundated
land areas with water depths typically less than 0.6 m that support the growth of emergent plants
such as cattail, bulrush, reeds, and sedges. The wastewater flows gradually through the vegetation
and solids settle out in the wetland. In cold climates, the operating depth is normally increased in
the winter to allow for ice formation on the surface and to provide the increased detention time
required at colder temperatures.
A conceptual wetland option has been developed based on the projected design flow and loads, as
well as on the design parameters listed in Table 4.3.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 15
Table 4.3: Polishing Wetland Design Parameters
Parameter Value
Average flow (m3/day) 840
Retention Time (days) 1
Wetland Type Free water surface
Water Depth (m) 0.6
Total Area of Wetland Cells (m2) 1,400
4.2.2.2 AERATED LAGOON
In aerated lagoons, oxygen is supplied by mechanical aeration, which in newer systems is typically
subsurface diffused aeration. They have average retention times ranging from 5 to 30 days, with 30
days being common in Atlantic Canada. They accept higher loading rates than stabilization basins,
are typically at least 3 m deep, require less land, and are typically less susceptible to odours. They
also have higher operational costs. They can be either completely or partially mixed. Completely-
mixed aerated lagoons are rarely cost effective because they use significantly more energy than
partially-mixed aerated lagoons and require additional solids separation infrastructure; therefore,
only the partially-mixed aerated lagoon will be assessed (subsequently referred to in this report as
“Aerated Lagoon”). These aerated lagoons can include a quiescent zone as part of the main
treatment cells or may be followed by a polishing pond or wetland to reduce suspended solids prior
to discharge.
The required retention times are calculated using Equations 4.1 and 4.2, above. The resulting
volume is targeting an effluent concentration around 20 mg/L in winter, and includes an allowance
for sludge storage.
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 4.4: Aerated Lagoon Design Parameters
Parameter Value
Maximum monthly flow (m3/d) 1,050
Number of Cells 4 aerated cells, 1 settling zone
Reaction Rate Constant K₂₀ (/d) 0.276
Retention Time in Treatment Volume at Average
Flow/Max Month (days) 12 / 9.5
Treatment Volume (m³) 10,000
Total Volume inc. settling and sludge allowance (m³) 13,700
Water Depth + Freeboard (m) 3.0+1.0
Side Slope 3:1
Total Area (at top of berm, m²) 8,700
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 16
4.3 Disinfection
Disinfection at WWTPs is typically provided using either chlorination or ultraviolet (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.
The UV system has been sized to achieve effluent limits of 200 E. coli/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.
At this site, there is a risk that a UV disinfection system will not be effective due to the amount of
iron entering the WWTP in the form of residual sludge from the New Waterford WTP. Sampling
should be done prior to detailed design to confirm that UV disinfection is feasible. Nonetheless, we
have carried a UV disinfection system at this time due to its many advantages listed above.
Flows from either the aerated lagoon or stabilization basin system will flow continuously by gravity
to the UV disinfection unit. Disinfection will take place in a single channel located in a building and
due to the low design UV transmission (%UVT) from these options, two banks of lamps are required.
The lamps are oriented horizontally and parallel to the direction of flow. The disinfected effluent
would flow by gravity to the outfall. The design parameters for the UV disinfection system are
summarized in the Table 4.5 below.
Table 4.5: UV Disinfection Design Parameters
Parameter Design Value
Number of Design Channels 1
Number of Banks 2
Number of Lamps per Bank 24
Total Number of Lamps 48
Peak Flow Capacity (m3/d) 2,800
Effluent TSS (mg/L) <25
Minimum Transmission (%UVT) 40
Effluent E. coli (MPN/100 mL) 200
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 17
4.4 Sludge Management
Sludge Management is an important variable to consider when investigating treatment options, as
sludge handling and disposal costs can constitute a large portion of a WWTP’s annual operating
budget. With either an aerated lagoon or stabilization basin, sludge is removed from the treatment
process on an infrequent basis compared to mechanical treatment plants.
Sludge must be removed periodically from the treatment system and disposed of at an approved
facility. Sludge management costs are greatly dependent on the quantity and quality of sludge
produced. Due to their long retention times and in-situ digestion, the two land-based technologies
under consideration are expected to produce less sludge than a mechanical treatment system.
Waste sludge volume from an aerated lagoon or stabilization basin in this sewershed, with a higher
than typical inorganic solids loading, is expected to be approximately 2,000 m3 sludge in 5 years. This
plant will need more frequent sludge removal than a typical lagoon, and is designed to allow Cell 1
and Cell 2 to be independently isolated for desludging approximately every 2-3 years.
Sludge management options include composting, geotextile bag stabilization, and digestion, at
either local or regional facilities. The recommended sludge management approach for all of CBRM’s
facilities is being evaluated as a separate component of this project. Due to the relative size of the
New Victoria WWTP, no sludge thickening has been included for this plant.
4.5 Secondary Treatment Option Evaluation
Both options were laid out on the site. The required setback of 75 m from the watercourse running
through the area can only be met with an aerated lagoon. The costs were not calculated in detail
for both options, since the stabilization basin was found not to be feasible for regulatory reasons;
however, the amount of fill required to develop a stabilization basin on the site would have made
the aerated lagoon the more cost-effective option even if the watercourse setback could have been
met.
4.5.1 Qualitative Evaluation Factors
In addition to 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 4.10, and additional
discussion is provided below the table. Qualitative factors have been rated 1 or 2 for each
technology with 1 being the best and 2 being the worst.
Table 4.6: Secondary Process Qualitative Evaluation Factors
Factor Aerated Lagoon Stabilization Basin
Local Experience with Process 2 1
Operational Simplicity 2 1
Sludge Production 2 1
Site Aesthetics 1 2
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 18
In terms of local experience with the treatment process, CBRM have experience with stabilization
basins at Meadowbrook, Tower Road, Reserve Mines (Centreville), and Birch Grove and also with an
aerated lagoon at Southwest Brook.
When considering operational simplicity, although both processes are fairly straightforward, the
stabilization basin option has the benefit of not having an aeration component.
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 stabilization basin will result in a slightly
lower sludge production than the aerated lagoon.
When considering site aesthetics, the aerated lagoon is more compact than the stabilization basin
and is less susceptible to odours. The preferred site is not large enough nor sufficiently remote to
be able to accommodate a stabilization basin while maintaining the recommended separation
distance of 300 m for more than 30 houses. The nearest residences would be about 150 m away.
The separation distance required for a stabilization basin in the ACWGM is 150 m from isolated
residences and 300 m from built-up areas. Stabilization basins are susceptible to odour problems,
and the plant might lead to recurring odour complaints if one were developed here. This is due both
to proximity to neighbouring houses, and to the prevailing winds around the time of spring turnover
(from the southwest) blowing odours into the most built-up areas of New Victoria.
The required setback of 75 m from the watercourse running through the area can only be met with
an aerated lagoon.
Land procurement would be somewhat simpler with the aerated lagoon because it can be built on
fewer properties, without having to buy land from so many owner to put together a parcel large
enough to accommodate the larger footprint of the stabilization basin; however, land for the access
road may need to be purchased as well if an easement is not possible.
The site topography means that developing a stabilization basin on this site would likely be more
costly than an aerated lagoon. Stabilization basins have a number of advantages, including
extensive CBRM experience, lower sludge production, and operational simplicity, but these would
not offset the significant aesthetic and regulatory disadvantages in this case. Therefore, the aerated
lagoon option will be carried forward for pre-design.
4.5.2 Recommended Secondary Treatment Process
HEJV recommends an aerated lagoon for the New Victoria WWTP. The selection of this process was
ultimately determined by ACWGM separation distances (to the watercourse), topography, land
procurement considerations, and aesthetics, including prevailing winds in spring (odour risks), and
proximity to neighbouring properties.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 19
CHAPTER 5 PRELIMINARY DESIGN
5.1 Preliminary Design Drawings
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
C02 Proposed WWTP
C03 Sewer Profiles and Lagoon Sections
5.2 Unit Process Descriptions
Drawing C01 and C02 in Appendix C include a site plan showing the location of the proposed new
WWTP. Further description of the proposed treatment units follows.
5.2.1 Preliminary Treatment
Flow from the New Victoria collection system will discharge into an influent chamber positioned at
the inlet of the plant. The influent chamber will be concrete and drop the flow to the elevation to be
gravity fed to the lagoon under the water’s surface. As the New Victoria WWTP site is a satellite
plant, CBRM has requested that the level of maintenance and operations be reduced as much as
reasonably and practically possible; however, including a coarse bar screen in the influent chamber
would remove litter and other large solids from the incoming flow, and prevent them from having to
be removed from the surface of the lagoon later on. For this reason we have included a manually-
raked coarse bar rack, but it may be possible to operate without preliminary treatment, if preferred.
5.2.2 Secondary Treatment
The secondary treatment process will consist of three aerated lagoon basins divided into four
aerated cells and one quiescent settling zone by means berms or floating baffles. All cells will be
partially mixed, with the exception of the settling zone. The first two cells will operate in parallel,
followed by the last two cells in series. This will allow any on the basins to be independently isolated
for sludge removal or for maintenance. Enough air will be provided to the aerated cells to meet
CBOD requirements and opportunistic nitrogen removal during the summertime. Control over
process flows within the treatment plant will be provided through effluent weirs in the control
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 20
manholes and the effluent chamber that will control the discharge flow and the water levels in the
aerated lagoon basins.
Each aerated cell will provide an average of 2.4 days of retention time at the maximum monthly
design flows. All of the readily biodegradable CBOD and most of the slowly biodegradable CBOD will
be consumed in the first four cells and a significant portion of solids will become solubilized and
treated in the first four cells.
The fourth cell will also contain an effluent polishing zone and will be separated from the third cell
by means of a floating curtain or baffle, anchored at the top and weighted at the bottom. The
floating baffles serve to minimize hydraulic short circuiting. The settling zone is non-aerated, and
sized for one day of retention, which is suitable for further settling of TSS and some further
degradation of pollutants. The settling zone hydraulic retention time is about one day, and this is
short enough to minimize algae growth during the warmest months.
The aerated lagoon will be configured to allow bypassing for emergency maintenance. Table 5.2
outlines the aerated lagoon design parameters.
Table 5.2: Secondary Treatment – Aerated Lagoon Design Summary
Parameter Design Value
Maximum Monthly Flow (m3/d) 1,050
No. of Cells 4 aerated cells, 1 settling zone
Total Volume inc. settling and sludge allowance (m³) 13,700
Treatment Volume (m³, per aerated cell) 2,500
Retention Time in Treatment Volume at Average
Flow/Max Month (days) 12 / 9.5
Depth (m) 3.00
Freeboard (m) 1.00
Side Slope 3:1
Total Area (at top of berm, m²) 8,700
Peak Oxygen Required (kg O2/day) 165
Peak Air required (SCFM) 300
A subsurface investigation is required to investigate soil conditions, assess bearing capacity and
determine the depth to groundwater and bedrock. For the purposes of this report, we have
assumed that bedrock is located about 2.5 m below the surface, and that the maximum
groundwater is not higher than the top of the bedrock layer. Following discussion with NSE, we
believe that it is permissible to use a reduced separation distance to bedrock under a small
proportion of the aerated lagoon. Maintaining the typical minimum separation distance of 1.5 m
on a sloping site with suspected shallow bedrock would require pumping more of the flow to the
site, and would also require large amounts of fill. If bedrock or groundwater are found significantly
closer to the surface, then the aerated lagoon grade line and collection system layout may need to
be adjusted to accommodate the site conditions. If necessary, a portion of the lagoon treatment
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 21
capacity could be replaced with equivalent capacity in a wetland, which is shallower. For the
purpose of this pre-design it is assumed a 60 mil HDPE membrane liner is required, and that some
localized drainage may be required to lower the groundwater level under a small proportion of the
lagoon.
5.2.2.1 AERATION SYSTEM
The aeration system will include fine bubble diffusers suspended from floating laterals. Fine bubble
aeration is more efficient compared to coarse bubble aeration due to the increased surface area of
the bubbles and the longer time it takes for the bubbles to rise to the surface, and coarse bubble
aerations is more efficient than surface aeration. There are a number of advantages with this type of
system including:
• Improved performance and energy efficiency over coarse bubble or mechanical aeration
systems;
• Resistance to fouling;
• System is retrievable;
• Equipment can be installed or diffusers replaced while the lagoons are in operation;
• System is less sensitive to undulations in the lagoon bottom;
• Improved air distribution, mixing and control capability; and
• Individual diffuser chains can be isolated for greater operational flexibility.
Low pressure air will be delivered by blowers through a system of headers, manifolds, distribution
pipe and floating laterals. The floating laterals will extend across the lagoon cells and deliver process
air to membrane diffusers that are suspended from the laterals. Diffuser location and distribution of
air will be tapered to provide increased aeration at the beginning of the process and less air farther
into the treatment process. Cell #1 and Cell #2 (parallel) will contain the highest density of diffusers
and will be governed by process air requirements. Cell #3 and Cell #4 will have significantly lower
diffuser density (number of diffusers per square meter) that will be gradually tapered as governed
by process air requirements.
The plant has been designed to operate with one duty blower, and a second standby blower in the
event of failure of the duty blower. It is recommended that the blowers operate with variable
frequency drives (VFDs). VFDs improve process control by controlling the speed of the blower, and
can thereby provide energy savings, and reduce wear and tear on motors.
5.2.3 Disinfection
Effluent leaving the settling cell will flow continuously by gravity to the ultraviolet (UV) disinfection
unit. The UV disinfection unit will be installed in a single stainless steel channel located in the
proposed process building. The UV system will consist of two banks of UV lamps. The lamps are
oriented horizontally and parallel to the direction of flow and contain 24 lamps per bank for a total
of 48 lamps. The UV weir height is a factor in setting the hydraulic grade line for the rest of the
treatment process.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 22
Tidal height values are taken from the measurement station at nearby Glace Bay, since there is none
in New Victoria. The higher high water elevation at large tide for Glace Bay was 1.5m Chart Datum
(CD) which is equivalent to 1.0 m CGVD28 (geodetic datum) for 2018. The estimated extreme water
level values for 100 year and 50 year return periods were 2.5m CD (2.0 m CGVD28) and 2.4 m CD
(1.9 m 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 Limited, 2018). Therefore, the UV
weir height must be set at a minimum elevation above the extreme tide/surge level (100-year return
selected) with an allowance for head losses over the weir, in the outlet sewer, and in the outfall of
approximately 6 m, for a minimum UV weir height of 9 m. The actual weir height will be higher than
this to accommodate the site grade. The design parameters for the UV disinfection system are
summarized in the Table 5.3.
Table 5.3: UV Disinfection Design Summary
Parameter Design Value
Average Flow (m3/d) 840
Peak Flow Capacity (m3/d) 2,800
Number of Channels 1
Number of Banks 2
Number of Lamp per Bank 24
Total Number of Lamps 48
Effluent TSS (mg/L) <25
Minimum UV Transmission (%UVT) 40
Effluent Fecal Coliforms (MPN / 100 mL) 200
5.2.4 Sludge Management
Sludge must be removed periodically from the treatment system and disposed of at an approved
facility. Sludge management costs are greatly dependent on the quantity and quality of sludge
produced. Approximately 215,000 kg of solids are expected to accumulate in 5 years of operation.
It is assumed that the solids will be dredged approximately every 2–3 years in Cell #1 and Cell #2,
and about every 5 years in Cell #3 and Cell #4. This is more frequently than usual, due to the higher
than typical rate of solids accumulation resulting from the New Waterford WTP backwash.
Sludge management options include composting, geotextile bag stabilization, and digestion, at
either local or regional facilities. The recommended sludge management approach for all of CBRM’s
facilities is being evaluated as a separate component of this project. Due to the relative size of the
New Victoria WWTP and the infrequent requirement for sludge removal, it is expected that no local
sludge management facility will be located at this plant.
5.3 Facilities Description
The WWTP project will include the following facilities, which are further described below:
• Site access and parking;
• Site fencing;
• Two aerated lagoon cells and a settling cell;
• Yard piping; and
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 23
• Process building, containing the following items:
o Blowers;
o UV disinfection area;
o Instrumentation and Controls;
o Sample location;
o Administration and storage area; and
o Washroom and sump with submersible pump.
5.3.1 Civil and Site Work
Civil and site work will include grading, drainage and site improvements. An access road will be
constructed around the perimeter of the WWTP to provide vehicle access. A laydown area for
desludging equipment will be included.
A significant amount of imported fill will likely be required to give the required vertical separation to
assumed bedrock and groundwater at this site. The top of berm will be at an elevation of 23.5 m,
and the bottom of the aerated lagoon will be at 19.5 m.
Yard piping will be HDPE for the air piping, and 200 mm diameter SDR 28 PVC for buried influent and
effluent pipework. All valves will be accessible to the operator.
An impermeable 60 mil HDPE membrane liner has been carried in the cost estimate, as well as local
drainage in the south-eastern corner of the lagoon.
Security fencing will surround the lagoon cells and process building, installed at the top outside edge
of the berm. The existing footpaths and ATV trails that cross the site will not be obstructed from
being re-established around the outside of the plant.
5.3.2 Architectural
The exterior wall system will be masonry block with polystyrene insulation to meet the
requirements of the current building code. The exterior face of the building envelope will be a brick
veneer similar to other WWTPs within CBRM. The roof will be a 5:12 pitched roof with pre-
engineered wooden trusses, complete with steel roofing. Interior doors and frames will be
galvanized steel with a factory applied paint finish. Windows and louvers will be anodized aluminum
to match existing features.
Interior walls will be concrete block with an industrial enamel finish. Interior metal surfaces will be
painted with epoxy paint and exterior metal will be finished with ultraviolet-resistant urethane
paint. The Process Area ceilings will be finished with an industrial enamel paint. Process Area floors
will be concrete and will be finished with either a concrete floor hardener or an industrial high build
epoxy finish depending on requirements.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 24
5.3.3 Mechanical
Potable water will be required at the site, and will be provided from an approximately 350 m water
service connection to the New Victoria distribution system on Daley Rd. Wastewater will be
pumped from a sump using a submersible pump to the influent chamber at the head of the plant.
Heating and ventilation will be provided by electric unit heaters and an exhaust fan.
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 5.4 summarizes the proposed classification for new facilities.
Table 5.4: Classification of Building Areas
Location Classification
UV Room Unclassified
Blower Room Unclassified
5.3.4 Electrical Service and Emergency Power
There is 3-phase electrical service available on both Daley Road and New Waterford Highway and it
will need to be extended to the site.
Permanent emergency power has not been included in the design of the New Victoria WWTP,
because the large retention time of the lagoon minimizes the effects of short power outages. We
recommend that provision be made to allow a portable generator to be connected in the event of a
prolonged power outage. A generator docking station and MTS would allow a generator to be easily
tied-in for critical process equipment, including blowers, UV disinfection, and flow measurement
instrumentation, and building services including freeze-protection heating.
5.3.5 Lighting
Exterior lighting will consist of building mounted luminaires illuminating areas immediately adjacent
the building, as well as pole mounted area lighting for access roadways and parking area. Exterior
lights will be LED where available or to suit application. Exterior lighting fixtures shall be vandal
resistant and outdoor rated.
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.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 25
5.3.6 Instrumentation
All equipment should be controlled via local control panels mounted inside the Process Building in
close proximity to the related equipment. The control panels for the UV Disinfection unit
equipment, flow meter, and blowers should be vendor supplied and designed to be integrated with
CBRM Electrical, Controls and SCADA Standards.
5.4 Staffing Requirements
Staffing at wastewater treatment plants will vary depending on a number of factors including the
following:
• Plant classification (I, II, III or IV)
• Plant size and treatment capacity
• Laboratory requirements
• Complexity of the unit processes
• Level of automation
• Maintenance of peripheral facilities such pumping stations, collection systems, septage
receiving, etc.
• Sensitivity of the receiving waters.
• Variation in flows and loads to the plant i.e. Industrial, municipal, storm water component.
Based on the Points Classification System in the ACWGM (Appendix A), the proposed WWTP is likely
to be ranked as a Class I level treatment plant by the regulators, and require at least a Class I
operator to oversee the WWTP. Class I plants of this size typically require about 1200 hours of
maintenance per year, or approximately half of a full-time position.
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 26
CHAPTER 6 PROJECT COSTS
6.1 Opinion of Probable Capital Cost
An opinion of probable capital cost for the recommended treatment process option is presented in
Table 6.1, detailed on the next page. Please note that the costs of interception and pumping are extra
and are detailed in New Victoria Collection System Pre-Design Brief (Harbour Engineering Joint Venture,
2019). Please note that the capital costs given are in 2019 dollars, and would typically be inflated at a
rate of approximately 3% per year going forward to the intended construction year (or indexed using the
actual construction cost index ratio if calculating the probable construction cost at a specific point after
2019).
6.2 Opinion of Probable Operating and Life Cycle Cost
An annual operating cost estimate for the recommended treatment process option is presented in
Table 6.2.
Table 6.2: Operating Cost Estimate
Category Annual Operation Cost
Staffing $50,000
Power $17,800
Sludge Disposal $6,000
Maintenance Allowance $3,000
Total $76,800
Project Manager: D. McLean
Est. by: A. Thibault/S.Ensslin
PROJECT No.: 187116 (Dillon)
182402.00 (CBCL)
UPDATED: August 6, 2019
1.0 517,000$
allow 1 115,000$ 115,000$
allow 10% 401,800$
2.0 2,568,000$
m2 19,000 5$ 95,000$
m3 excavated 2,000 20$ 40,000$
Fill - Borrow m3 filled 1,500 10$ 15,000$
Fill - Imported m³ filled 47,000 30$ 1,410,000$
Rock m³ removed 2,000 60$ 120,000$
Liner and baffles m2 9,000 12$ 108,000$
m3 54 40$ 2,160$
m 400 400$ 160,000$
Inlet/Outlet Chamber allow 2 20,000$ 40,000$
m 315 340$ 107,242$
m 235 600$ 141,000$
m 100 100$ 10,000$
m 400 150$ 60,000$
allow 1 90,000$ 90,000$
m 200 60$ 12,000$
ea.6 6,000$ 36,000$
m 600 100$ 60,000$
allow 1 22,000$ 22,000$
allow 1 20,000$ 20,000$
allow 1 20,000$ 20,000$
3.0 44,000$
m3 of baseslab 20 650$ 13,000$
m3 of concrete 30 900$ 27,000$
allow 10%4,000$
4.0 70,000$
m2 wall area 151 170$ 25,704$
m2 wall area 138 323$ 44,514$
5.0 47,000$
m2 building area 90 409$ 36,799$
allow 10,000$
6.0 44,000$
m2 building area 90 40$ 3,600$
m2 building area 90 65$ 5,850$
m2 building area 90 43$ 3,874$
m2 building area 90 108$ 9,684$
m2 building area 90 15$ 1,350$
each 3 2,000$ 6,001$
each 2 1,100$ 2,200$
each 2 2,200$ 4,400$
m2 building area 90 75$ 6,750$
7.0 347,000$
each 1 236,250$ 236,250$
each 1 91,222$ 91,222$
each 1 20,000$ 20,000$
8.0 285,000$
m2 building area 90 470$ 42,300$
allow 30% of equipment 30% 104,100$
allow 40% of equipment 40% 138,800$
9.0 613,000$
allow 15% of project cost 15% 510,750$
allow 3% of project cost 3% 102,150$
4,535,000$
A 25% 1,134,000$
B 12% 544,000$
C 200,000$
6,413,000$
15%962,000$
7,375,000$
Note 1 A Design Development Contingency is to allow for necessary increases of qty's; construction costs; as the work is better defined
Note 2 A Construction Contingency is to allow for cost of additional work over and above the contract Awarded price.
Note 3 The Escalation/Inflation allowance is for increases in construction costs from time the budget to Tender Call
Note 4 The Location Factor is for variances between constr. costs at the location of the project & historical costs data
Form CBCL 034.Rev 0
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.
Taxes (HST)
TOTAL DIRECT & INDIRECT CONSTRUCTION COST (Exluding Contingencies and Allowances)
TOTAL CONSTRUCTION & DESIGN COST without HST
TOTAL CONSTRUCTION & DESIGN COST with HST
Land Purchase
Engineering
Construction Contingency
General Conditions
CONTINGENCIES and ALLOWANCES
Instrumentation & Control
Process Installation
UV Disinfection System
Door (double swing steel)
Other Interior Finishes, Misc
Process Equipment Supply
Aeration Equipment
Mechanical
HVAC and Plumbing
Electrical
Power Supply & Distribution
Process Mechanical
Interior Masonry
Concrete
Roof (Pre-Eng Wood Trusses and steel roofing)
Foundation and Exterior Building Walls
Chainlink Fence and Gates
Manholes
Field tile
Aeration Header (200 mm HDPE)
Masonry
Windows (exterior - single)
Doors (single swing steel)
Slab on Grade (building)
Miscellaneous Concrete Items
Exterior Masonry
Metals & Roofing
Carpentry, Assessories and Fixtures
Louvers
Painting
Epoxy Coating
Floor Finishes (Lab, Office, Admin Area)
Finishes/Doors/Windows
Miscellaneous Metals Items
UNIT COST
Reinstatement
Gravel (beneath slabs)
Ditching
Water Service
Gravel Road
Pressure sewer from sump in process building
Yard pipework (200 mm PVC)
Dewatering
Sediment Control
Mobilization, Bonds, Insurance, P.C. Mngmt
Contractor Overhead & Fees
Clear Grub; Site Preparation
Excavation
Flow measurement
Table 6.1
PREPARED FOR:OPINION OF PROBABLE CONSTRUCTION COST
Class C Preliminary Budget
Cape Breton Regional MunicipalityNew Victoria, NS
Total
Site Works
EST. QUANTITY
Wastewater Treatment System Costs Only
ITEM / No.DESCRIPTION UNIT
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 28
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.
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 (Outfall
and Yard Piping, Manholes and
Other)
$3,085,000 75 1.3% $41,000
Treatment Structures (Concrete
Chambers, etc.)
$205,000 50 2.0% $4,000
Treatment Equipment
(Mechanical / Electrical, etc.)
$1,245,000 20 5.0% $62,000
Subtotal $4,535,000 - - $107,000
Construction Contingency (Subtotal x 25%): $27,000
Engineering (Subtotal x 12%): $13,000
Opinion of Probable Annual Capital Replacement Fund Contribution: $147,000
Table Notes
1. Annual contributions do not account for annual inflation.
2. Costs do not include applicable taxes
Harbour Engineering Joint Venture New Victoria WWTP Preliminary Design 29
CHAPTER 7 REFERENCES
ABL Environmental Consultants Limited. (2006). Atlantic Canada Wastewater Guidelines Manual for
Collection, Treatment and Disposal. Environment Canada.
CBCL Limited. (2018). Glace Bay Harbour Coastal Study – Final Report. Halifax: CBCL Limited.
Harbour Engineering Joint Venture. (2019). New Victoria Collection System Pre-Design Study.
Metcalf & Eddy, Inc. (2003). Wastewater Engineering: Treatment and Reuse. New Delhi: Tata
McGraw-Hill.
Nova Scotia Utility and Review Board. (2013). Water Utility Accounting and Reporting Handbook.
UMA Engineering Limited. (1994). Industrial Cape Breton Wastewater Characterization Programme
– Phase II.
Harbour Engineering Joint Venture Appendices
APPENDIX A
Flow Data
0
10
20
30
40
50
60
70
800
1,000
2,000
3,000
4,000
5,000
6,000
Feb-21 Feb-28 Mar-07 Mar-14 Mar-21 Mar-28 Apr-04 Apr-11 Apr-18 Apr-25 May-02
Pr
e
c
i
p
i
t
a
t
i
o
n
Fl
o
w
(
m
³
/
d
)
Snow on Ground (cm)Rainfall (mm)Metered Flow
Harbour Engineering Joint Venture Appendices
APPENDIX B
Environmental Risk Assessment
Harbour Engineering Joint Venture Appendices
APPENDIX C
Conceptual Plant Layouts
j o i n t v e n t u r e
C01
CONCEPT
DRAWING
j o i n t v e n t u r e
C02
CONCEPT
DRAWING
j o i n t v e n t u r e
C03
CONCEPT
DRAWING
HEJV New Victoria Wastewater System Pre‐Design Summary Report Appendices
APPENDIX C
New Victoria Environmental Risk
Assessment
182402.00 ● Report ● April 2020
New Victoria Wastewater Treatment Plant
Environmental Risk Assessment
Final Report
Prepared by:Prepared for:
March 2020
Final April 16, 2020 Darrin McLean Karen March Holly Sampson
Draft for Review June 27, 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
275 Charlotte Street
Sydney, Nova Scotia
Canada
B1P 1C6
Tel: 902-562-9880
Fax: 902-562-9890
_________________
182402 RE 001 FINAL WWTP ERA NEW VICTORIA/mk
ED: 15/04/2020 15:26:00/PD: 15/04/2020 15:27:00
April 16, 2020
Matt Viva, P.Eng.
Manager Wastewater Operations
Cape Breton Regional Municipality (CBRM)
320 Esplanade,
Sydney, NS B1P 7B9
Dear Mr. Viva:
RE: New Victoria Wastewater Treatment Plant ERA – Final Report
Enclosed, please find a copy of the Environmental Risk Assessment (ERA) Report
for the New Victoria Wastewater Treatment Plant (WWTP).
The report outlines Environmental Quality Objectives (EQOs) for all parameters
of potential concern listed in the Standard Method for a “small” facility.
Environmental Discharge Objectives (EDOs) were also calculated for all
parameters of potential concern.
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
March 27, 2020
Harbour Engineering Joint Venture New Victoria 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 Wastewater Characterization ...................................................................... 4
2.1 Substances of Potential Concern .................................................................................. 4
2.1.1 Whole Effluent Toxicity ..................................................................................... 5
2.2 Wastewater Characterization Results .......................................................................... 5
CHAPTER 3 Environmental Quality Objectives ......................................................................... 7
3.1 Water Uses .................................................................................................................... 7
3.2 Ambient Water Quality ................................................................................................. 8
3.3 Physical/ Chemical/ Pathogenic Approach ................................................................. 10
3.3.1 General Chemistry/ Nutrients ........................................................................ 10
3.3.2 E. coli ............................................................................................................... 14
3.3.3 Summary ......................................................................................................... 14
CHAPTER 4 Mixing Zone Analysis ........................................................................................... 16
4.1 Methodology ............................................................................................................... 16
4.1.1 Definition of Mixing Zone ............................................................................... 16
4.1.2 Site Summary .................................................................................................. 18
4.1.3 Far-Field Modeling Approach and Inputs ....................................................... 18
4.2 Modeled Effluent Dilution .......................................................................................... 21
CHAPTER 5 Effluent Discharge Objectives .............................................................................. 24
5.1 The Need for EDOs ...................................................................................................... 24
5.2 Physical/ Chemical/ Pathogenic EDOs ........................................................................ 24
5.3 Effluent Discharge Objectives ..................................................................................... 25
CHAPTER 6 Compliance Monitoring ....................................................................................... 26
CHAPTER 7 References .......................................................................................................... 27
Appendices
A Laboratory Certificates
Harbour Engineering Joint Venture New Victoria 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 New Victoria 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 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 Effluent 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 substances of concern, and characterization of the
Harbour Engineering Joint Venture New Victoria WWTP ERA 2
receiving water to determine beneficial water uses, ambient water quality, assimilative capacity, and
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 New Victoria Wastewater Treatment Plant (WWTP) will be constructed to the east of
Daley Road, north of the New Waterford Highway. Treated effluent will be discharged to the
Atlantic Ocean at the location of the existing outfall at the end of Daley Road (Figure 1.2). The
service population of New Victoria is 604 people in 283 residential units.
Figure 1.1 Site Location
Harbour Engineering Joint Venture New Victoria WWTP ERA 3
Figure 1.2 WWTP Location
The theoretical domestic wastewater flow is an average of 205 m3/day with a peak of 800 m3/day
based on a per capita flow of 340 L/person/day and a peaking factor of 3.9 calculated using the
Harmon formula. The sewer system was flow metered from February 23 to May 1, 2018. The meter
location is just upstream of the discharge and encompasses the entire wastewater system. The
average dry weather flow was 523 m3/day (866 L/p/d or 193 IG/p/d). The average daily flow during
the metering period was 840 m3/day (1391 L/p/d or 306 IG/p/d). The maximum daily flow during
the metering period was 2511 m3/day. This occurred during a large rain event (50.8mm according
to Sydney A rain gauge, or 79.1mm according to Sydney CS rain gauge).
For the purposes of this ERA, the average daily flow for the metering period of 840 m3/day will be
used. However, this flow is likely higher than the average annual flow as the flow was only metered
for seven weeks which occurred during a wet period (March and April 2018). The preliminary design
of the WWTP was completed based on a design average daily flow of 840 m3/d and a maximum
month flow of 1050 m3/day. As the population in this area is declining, accounting for a projected
population increase during the life of the plant was not necessary.
Harbour Engineering Joint Venture New Victoria WWTP ERA 4
CHAPTER 2 INITIAL WASTEWATER 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 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, only one sample event was completed of the untreated wastewater.
Sample results of the untreated wastewater were also available for some of the parameters of
potential concern from 3.5 years of monthly sampling conducted by CBRM from mid-2014 through
2017. 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 ERA, the average daily flow during the metering period of
840 m3/day will be used. As discussed previously, the actual average annual daily flow is expected
to be lower than this. Therefore, the WWTP is classified as a “small” facility based on an average
daily flow rate between 500 and 2,500 m3/day.
The substances of potential concern for a “small” facility, as per the Standard Method, are detailed in
Table 2.1. There were no additional substances of potential concern identified to be monitored as there
is no industrial input to the wastewater system.
Table 2.1 Substances of Potential Concern for a Small Facility
Substance Group Substances
General Chemistry/ Nutrients
Total Suspended Solids (TSS)
Carbonaceous Biochemical Oxygen Demand (CBOD5)
Total Residual Chlorine (TRC) if chlorination is used
Total Ammonia Nitrogen
Total Kjeldahl Nitrogen (TKN)
Total Phosphorus (TP)
pH
Temperature
Pathogens E. coli
Harbour Engineering Joint Venture New Victoria WWTP ERA 5
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 untreated wastewater characterization sample collected by Harbour
Engineering (HE) is provided in Table 2.2. A summary of the results of untreated wastewater
characterization samples collected by CBRM from 2014 through 2017 are summarized in Table 2.3.
Table 2.2 Initial Wastewater Characterization Results
Parameter Units 23-Apr-18
CBOD5 mg/L 61
Total Kjeldahl Nitrogen (TKN) mg/L 6
Nitrogen (Ammonia Nitrogen) as N mg/L 2.3
Unionized ammonia(1) mg/L 0.0089
pH pH 7.15
Total Phosphorus mg/L 0.83
Total Suspended Solids mg/L 40
E. coli MPN/ 100mL >240000
Total Coliforms MPN/ 100mL >240000
Note: (1) The value of unionized ammonia was 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 New Victoria WWTP ERA 6
Table 2.3 CBRM Wastewater Characterization Samples
Parameter Units Average Maximum Number of Samples
CBOD5 mg/L 52 190 43
Nitrogen (Ammonia Nitrogen) as N mg/L 2.8 7.2 19
Unionized Ammonia mg/L 0.006 0.017 19
pH units 6.9 7.1 19
Total Suspended Solids mg/L 200 830 43
As mentioned previously, although the frequency of testing specified by the Standard Method was
not met, the ERA will be completed with the available data.
Harbour Engineering Joint Venture New Victoria WWTP ERA 7
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. Effluent
is required to be non-acutely toxic at the end of pipe and non-chronically toxic at the edge of the mixing
zone.
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 New Victoria. 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 New
Victoria:
• Secondary contact recreational activities like boating and fishing; and
Harbour Engineering Joint Venture New Victoria WWTP ERA 8
• Ecosystem health for fisheries and marine aquatic life.
There are no molluscan shellfish harvesting areas or public beaches in the vicinity of New Victoria. The
outfall is situated in a molluscan shellfish closure zone boundary extending from Point Aconi to
Schooner Pond (approximately 3.48km from the discharge). The closure zone boundary is shown on
Figure 3.1.
Figure 3.1 Location of Outfall
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:
• BG-1: Near Mira Gut Beach
• BG-2: Wadden’s Cove
Harbour Engineering Joint Venture New Victoria WWTP ERA 9
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 the sample was impacted by
wastewater. Samples were collected as grab samples from near shore using a sampling rod. A
summary of the ambient water quality data is shown in Table 3.1.
Table 3.1 Ambient Water Quality Data
Parameter Units BG1 BG2 AVG
Carbonaceous BOD (CBOD) mg/L <5.0 <5.0 <5.0
Total Kjeldahl Nitrogen (TKN) mg/L 0.19 0.20 0.20
Nitrogen (Ammonia Nitrogen) mg/L <0.050 <0.050 <0.05
unionized ammonia mg/L <0.0007 <0.0007 <0.0007
pH pH 7.73 7.68 7.71
Total Phosphorus (TP) mg/L 0.037 0.032 0.035
TRC(1) mg/L NM NM NM
TSS mg/L 58 5.0 32
E. coli MPN/100mL 52 86 69
Total Coliforms MPN/100mL 16000 6900 11450
Note:
(1) NM = Parameter not measured.
Harbour Engineering Joint Venture New Victoria WWTP ERA 10
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
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 New Victoria
WWTP is a marine environment, the marine guidelines were used, where available.
Site-specific EQOs are derived in the following sections for each substance of potential concern.
3.3.1 General Chemistry/ Nutrients
The following general chemistry and nutrients parameters were identified as substances of potential
concern for a small facility: CBOD, un-ionized ammonia, total ammonia, total nitrogen, total kjeldahl
nitrogen (TKN), total suspended solids (TSS), total phosphorus, pH, and total residual chlorine (TRC).
EQOs for these substances are established in the following sections.
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.
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.
Harbour Engineering Joint Venture New Victoria WWTP ERA 11
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. For an ocean discharge, the maximum DO deficit should occur at the point source.
Assuming a deoxygenation rate of 0.33/day based on a depth of approximately 2m at the discharge
location, and assuming a reaeration coefficient of 0.61/day based on a depth of approximately 2m
and an average tidal velocity of 0.175 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 47.2 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.
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, which is why the total ammonia guideline is given by pH and
temperature. Table 3.2 shows the CWQGs for total ammonia, as reproduced from the guidelines.
Table 3.2 CWQG for Total Ammonia (mg/L NH3) for the Protection
of Aquatic Life (Freshwater)
Temp (˚C) pH
6.0 6.5 7.0 7.5 8.0 8.5 9.0 10
0 231 73.0 23.1 7.32 2.33 0.749 0.250 0.042
5 153 48.3 15.3 4.84 1.54 0.502 0.172 0.034
10 102 32.4 10.3 3.26 1.04 0.343 0.121 0.029
15 69.7 22.0 6.98 2.22 0.715 0.239 0.089 0.026
20 48.0 15.2 4.82 1.54 0.499 0.171 0.067 0.024
25 33.5 10.6 3.37 1.08 0.354 0.125 0.053 0.022
30 23.7 7.5 2.39 0.767 0.256 0.094 0.043 0.021
Notes:
• It is recommended in the guidelines that the most conservative value be used for the pH and temperature
closest to the measured conditions (e.g., the guideline for total ammonia at a temperature of 6.9˚C and pH of 7.9
would be 1.04 mg/L);
• According to the guideline, values falling outside of shaded area should be used with caution; and
• Values in the table are for Total Ammonia (NH3); they can be converted to Total Ammonia Nitrogen (N) by
multiplying by 0.8224.
Harbour Engineering Joint Venture New Victoria WWTP ERA 12
The CWQG for total ammonia in freshwater is 0.499 mg/L or 0.41 mg/L NH3 as nitrogen, which is
based on an average background pH of 7.7 and a maximum monthly average temperature of 17.7
°C. The USEPA 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 USEPA 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
5mg/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, regardless of the background TSS
concentration, application of the WSER criteria at the end of pipe will always be the most stringent
criteria provided there is greater than 5 times dilution.
Total Phosphorus and TKN/TN
There are no CWQGs for the protection of aquatic life for phosphorus or Total Kjeldahl Nitrogen.
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 very time and
resource intensive, but can be completed on a more limited scale to establish interim guidelines.
Harbour Engineering Joint Venture New Victoria WWTP ERA 13
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.
Table 3.3 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 TKN and TP were measured as 0.2 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.
Table 3.4 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 3.4 are based on dissolved nitrogen and phosphorus and the
background concentrations are for TKN and total phosphorus. For nitrogen, with a background
concentration of 0.2 mg/L for TKN, an assumption that the dissolved nitrogen background
concentration is anywhere between 50 and 100% of the TKN background concentration would result
in classification as “medium” based on Table 3.4. 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 3.4.
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 TN concentrations, an assumption must be made as to the percentage of the TN
and phosphorus that exists in the dissolved phase, both in the receiving water and in the effluent.
Harbour Engineering Joint Venture New Victoria WWTP ERA 14
As a measure of conservatism, an assumption was made that 100% of the TN 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.
Total Residual Chlorine
The WSER requires that TRC concentrations be less than 0.02 mg/L. For the purposes of this study,
the EQO of 0.02 mg/L for TRC was chosen based on this regulation.
3.3.2 E. coli
Pathogens are not included in the CCME WQGs 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 1000 E. coli/ 100mL based on the Canadian Recreational Water Quality guideline for
secondary contact for freshwater will apply outside the mixing zone. There are no public beaches in
the vicinity of the discharge.
3.3.3 Summary
Table 3.5 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;
• 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;
• HC Secondary Contact – Health Canada Guidelines for Canadian Recreational Water Quality –
Secondary Contact Recreation.
Harbour Engineering Joint Venture New Victoria WWTP ERA 15
Table 3.5 EQO Summary
Parameter Generic
EQO Background Selected
EQO Source
CBOD5 (mg/L) 25 <5.0 25(1) WSER
TN (mg/L) 1 0.2 1 CGF, Marine
Nitrogen (Ammonia Nitrogen) (mg/L) 2.7 <0.05 2.7(2) USEPA Saltwater
Unionized Ammonia (as N at 15°C) (mg/L) 1.25 <0.0007 1.25(1) WSER
pH 7.0 – 8.7 7.71 7.0 – 8.7 CWQG Marine
Total Phosphorus (mg/L) 0.1 0.035 0.1 CGF, Marine
TRC (mg/L) 0.02 NM 0.02(1) WSER
TSS (mg/L) 25 32 25(1) WSER
E. coli (Secondary Contact) (MPN/ 100mL) 1000 69 1000 HC Secondary
Contact
Notes:
Bold indicates EQO is a WSER requirement.
(1) EQO applies at the end of pipe.
(2) Although the EQO for ammonia has been calculated to be 2.7 mg/L, an 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 New Victoria WWTP ERA 16
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);
Harbour Engineering Joint Venture New Victoria WWTP ERA 17
• 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;
• 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, 1996).
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(1) or 250 m(2) radius from the outfall and/or a dilution limit. A Draft for
Discussion document “Mixing Zone Assessment and Report Templates” dated July 7, 2016 that was
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. 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.”
1 Environment Canada, 2006 - Atlantic Canada Wastewater Guidelines Manual for Collection, Treatment, and Disposal
2 NB Department of Environment & Local Government, 2012 Memo.
Harbour Engineering Joint Venture New Victoria WWTP ERA 18
As the critical low flow 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 critical low flow 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.
4.1.2 Site Summary
The WWTP is 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. The low tide and -1.0 m depth
contours were estimated based on navigation charts. The total average effluent discharge is
modeled as a continuous point source of 840 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 outfall of approximately -1.0 m Chart
Datum and by the presence of the shoreline. Since the outfall is in very shallow water, the buoyant
plume will always reach the surface upon release from the outfall3. 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 Dominion4; 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 ASA5 on local
oceanography and effluent dispersion; and
• 2006 current meters (2 locations) off the Donkin peninsula for the CBCL study of mine
effluent dispersion.
3 Fisher et al., 1979. Mixing in Inland and Coastal Waters. Academic Press, London.
4 CBCL Limited, 2005. Dominion Beach Sewer Study. Prepared for CBRM.
5 ASA Consulting Limited, 1994. “Industrial Cape Breton Receiving Water Study, Phase II”. Prepared for The Town of Glace
Bay.
Harbour Engineering Joint Venture New Victoria WWTP ERA 19
Calibration consisted of adjusting the following parameters:
• Bottom friction;
• Model spatial resolution in the area of the current meters.
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
and Modeled Outfall Location
Harbour Engineering Joint Venture New Victoria WWTP ERA 20
Figure 4.2 Time-series of Hydrodynamic Model Inputs and Calibration Outputs
Harbour Engineering Joint Venture New Victoria WWTP ERA 21
4.2 Modeled Effluent Dilution
Snapshots of typical modeled effluent dispersion patterns are shown on Figure 4.3. Statistics on
effluent concentrations were performed over the 1-month model run, and over a running seven-day
averaging period. Composite images of maximum and average effluent concentrations are shown
on Figure 4.4.
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 1-
day average effluent concentration criteria over the 1-month modeling simulation that includes a
representative combination of site-specific tides and winds.
The diluted effluent plume often reaches the shoreline 100 m to the East and South of the outfall as
well as the shoreline farther away to the northwest. The location of the maximum concentration
does not appear to be directly tied to the tidal cycle but rather to the local currents as a result of
both the wind and the tide. 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.
The maximum daily average effluent concentration 100 m away from the outfall over the simulation
period is 0.172 % (Table 4.1). Therefore we propose that a 581:1 dilution factor be used for
calculating EDOs based on the maximum 1-day average effluent concentration at 100 m from the
discharge.
Table 4.1 Modelled Dilution Values 100 and 200 m away from the Outfall
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 1.228 % (81:1
Dilution)
0.172 % (581:1
Dilution)
0.081 % (1235:1
Dilution)
0.079 % (1266:1
Dilution)
200 m 0.691 % (145:1
Dilution)
0.132 % (758:1
Dilution)
0.051 % (1961:1
Dilution)
0.044 % (2273:1
Dilution)
Harbour Engineering Joint Venture New Victoria WWTP ERA 22
Figure 4.3 Snapshots of Typical Modeled Effluent Dispersion Patterns
Harbour Engineering Joint Venture New Victoria WWTP ERA 23
Figure 4.4 Composite Images of Modeled Hourly Maximum (top) and Maximum 7-Day Average
Effluent Concentrations (middle) with Concentration Time-Series (bottom)
Note: 100-m radius (black) and 200-m radius (grey) circle shown around outfall
Harbour Engineering Joint Venture New Victoria WWTP ERA 24
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 3.3 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 there are a limited number of parameters considered as substances
of potential concern for very small and small facilities, EDOs will be developed for all substances of
potential concern.
5.2 Physical/ Chemical/ Pathogenic EDOs
For this assessment, EDOs were calculated using the dilution values obtained at the average daily
flow of 840 m3/day that was measured during the metering period. This resulted in a dilution of
581:1 at the edge of a 100 m mixing zone.
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 New Victoria WWTP ERA 25
5.3 Effluent Discharge Objectives
Substances of concern for which an EDO was developed are listed in Table 5.1 below with the
associated EQO, maximum measured wastewater concentration, and the associated EDO.
Table 5.1 Effluent Discharge Objectives at Average Annual Flow
Parameter
Maximum
Wastewater
Concentration
Background Selected
EQO Source Dilution
Factor EDO
CBOD (mg/L) 190 <5.0 25 WSER - 25
TN (mg/L) 6 0.2 1 CGF, Marine 581 468
Total NH3-N
(mg/L) 7.2 <0.05 2.7 USEPA Saltwater 581 1569
Unionized NH3
(mg/L) 0.017 0 1.25 WSER - 1.25
TP (mg/L) 0.83 0.03 0.1 CGF, Marine 581 38
TRC (mg/L) NM NM 0.02 WSER - 0.02
TSS (mg/L) 830 31.5 25 WSER - 25
E. coli (MPN/
100mL) >240,000 69 1000 HC Secondary
Contact 581 540,980
Based on the EDOs calculated above, sample results for the following parameters exceeded the EDO
in at least one wastewater sample:
• CBOD5;
• TSS; and
• E. coli.
These parameters will meet the EDOs at the discharge of the new WWTP through treatment.
Harbour Engineering Joint Venture New Victoria WWTP ERA 26
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 New Victoria WWTP ERA 27
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 New Victoria WWTP ERA 28
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 New Victoria Wastewater System Pre‐Design Summary Report Appendices
APPENDIX D
New Victoria Wastewater Treatment Facility
Site Desktop Geotechnical Review
301 Alexandra Street, Sydney, NS B1S 2E8
t: 902.562.2394 f: 902.564.5660 www.exp.com
October 22, 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
New Victoria Site
Dear Mr. Boutilier:
It is the pleasure of EXP Services Inc. (EXP) to provide Dillon Consulting Limited (Dillon) with this letter
report summarizing the preliminary review completed by EXP on the potential site for the
construction of a wastewater treatment facility in New Victoria, 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);
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Desktop Study – New Victoria Site
SYD-00245234-A0
October 22, 2018
2
M:\SYD-00245234-A0\60 Project Execution\60.2 Reports\New Victoria\New Victoria_Site.docx
• 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 on a vacant lot off Daily
Road in New Victoria, Nova Scotia and is identified by three Property Identification Numbers (PIDs),
15267057, 15267099 and 15267107. The subject property is relatively level, but slopes slightly from
the southeast toward the northwest. The property then drops off rapidly along the coastline (cliff face)
of Sydney Harbour. The property is bound by the Atlantic coastline along the northern and
northwestern perimeters of the site; residential and forested/marsh areas along the eastern and
southern perimeters of the site; and a mine water treatment facility to the northeast. Figure 1 outlines
the proposed location of the site.
Figure 1: Proposed footprint of the new WWTP in New Victoria.
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.
Engineered Wetland
Stabilization Pond
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Desktop Study – New Victoria Site
SYD-00245234-A0
October 22, 2018
3
M:\SYD-00245234-A0\60 Project Execution\60.2 Reports\New Victoria\New Victoria_Site.docx
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.
A review of historical mapping and online reference documents indicated that mining activities have
been carried out extensively in an area west and southwest of the proposed construction site (but not
directly under the site). The workings were the standard room and pillar coal extraction process. It
should be noted that pillars may have been mined at some point. Mapping indicates that the site is just
north of the Lloyd Seam and south of the Hub (Barrasois) Seam outcroppings. Two abandoned mine
openings (AMOs) were identified as being found on the site. The AMOs have the identification numbers
SYM-1-414 and SYM-1-415. Review of the reports suggest that both openings were backfilled to grade
as a protective measure.
Existing Ground Conditions
At the time of the investigation, the site was covered with thick vegetation (densely wooded areas) and
relatively thin peat bog deposits. Historical reports suggest that the peat found on-site ranged in
thickness from 25 to 30 cm and covers approximately 5 to 15% of the land area. The peat bog and
mossy area overburden materials are not suitable for construction and should be completely removed
from the footprint of the facility. All-terrain vehicle (ATV) trails were observed crisscrossing over the
site exposing the underlying glacial till materials below.
The overburden soil (glacial till) exposure was observed along the cliffside. The thickness of the
overburden appears to be in the range of 1.5 to 2.5 metres thick (thicker accumulations are expected
deeper inland). 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 and 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. A Coastal
Protection Plan will be required for this site.
• The area west and southwest of the site was undermined due to historical coal mining activities
and there is a potential for undocumented bootleg pits/mines in the area.
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Desktop Study – New Victoria Site
SYD-00245234-A0
October 22, 2018
4
M:\SYD-00245234-A0\60 Project Execution\60.2 Reports\New Victoria\New Victoria_Site.docx
• 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).
• It is anticipated that the overburden soil will be in a very moist to wet condition near the
surface, in particular near the marshy/boggy areas. This will create some problems during site
preparation and construction. A Surficial and Groundwater Control Plan should be developed
for the site.
• The presence of uncontrolled fills, foundation and construction debris is suspected on the site
due to historical activities (residences and development) on the site.
Previous Land Use
Aerial photographs from 1931 to 2018 have been reviewed and are summarized below.
• An aerial photograph taken in 1931 depicts three residential dwellings on the proposed site.
Several driveways and footpaths were observed crisscrossing the subject site. The site is
primarily covered in low lying vegetation with some treed areas. Mining activities and
infrastructure are visible southwest of the site. Residential dwellings were also observed along
the western and southern perimeters of the site.
• An aerial photograph taken in 1947 depicts little to no discernable change to the site since the
1931 photograph was taken.
• An aerial photograph taken in 1953 depicts that the three historical building on the site have
been removed. Vegetation and development of an area (possible strip mining activities) were
observed at the southeast corner of the subject site.
• An aerial photograph taken in 1966 depicts a mine being constructed to the northeast of the
site. A waste rock haul road was installed across the northern perimeter of the site, which led
to a dumping site over the side of the coastline cliff. Additional roadways and trails were
observed crossing the site. Additional tree clearing was completed around the perimeter of the
development area identified in the 1953 photographs.
• An aerial photograph taken in 1977 depicts further expansion and devolvement of the area on
the southeast corner of the site. Additional roadways are visible crossing the site.
• An aerial photograph taken in 1987 further depicts development activities along the southern
perimeter of the site. Two new structures are visible within the footprint of this development
on the southeast corner of the site.
• Aerial photograph taken in 1993 depicts that the mine to the northeast of the site has been
abandoned. Furthermore, the development actives along the south perimeter of the site have
ceased. The two structures identified in the 1987 aerial photograph have been removed.
• Aerial photographs taken between 2005 and 2010 show little to no change to the site apart
from increased vegetation growth.
• Aerial photograph taken in 2011 depicts the new mine water treatment facility being
constructed northeast of the site (near footprint of previous mine workings).
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Desktop Study – New Victoria Site
SYD-00245234-A0
October 22, 2018
5
M:\SYD-00245234-A0\60 Project Execution\60.2 Reports\New Victoria\New Victoria_Site.docx
Proposed Supplemental Ground Investigation Methods
It is also recommended that a preliminary geotechnical investigation (land based drilling and test pit
program) be completed at the site. These programs are to be completed in conjunction with each other
to:
• verify the presence or absence of authorized and/or bootleg mining activities undertaken in
the area;
• identify the potential of future subsidence that could impact structures constructed on the
site; and
• verify the presence or absence as well as extent of uncontrolled fills (foundations, construction
debris, loose laid soils) within the footprint of the new facility.
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 Program
Borehole locations should be selected based upon the location of buried infrastructure (sewer, water,
electrical and fiber optic lines) and to provide adequate coverage of the proposed site. It is proposed
that representative soil samples be collected continually throughout the overburden material of each
of the four boreholes advanced at the site. Additionally, it is recommended that during the investigation
samples of the bedrock should be collected continuously to a depth of at least 30 metres or more, in
two of the four 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 (if applicable).
• accurately characterize the bedrock for design of either driven or drilled piles, if needed.
It is recommended that the remaining two boreholes 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 perused.
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
Dillon Consulting Limited
Wastewater Treatment Plant Geotechnical Desktop Study – New Victoria Site
SYD-00245234-A0
October 22, 2018
6
M:\SYD-00245234-A0\60 Project Execution\60.2 Reports\New Victoria\New Victoria_Site.docx
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.
Test Pit Program
Test pit locations should be selected to provide adequate coverage of the site and must encompass
areas whereby historical structures had once resided. Additional test pits should be installed along the
southern perimeter of the site to delineate the extent of the historical development on this area. At
this time, it is suggested that 20 test pits be installed at the site using an 20 tonne excavator under the
direction of a Geotechnical Engineer. Each test pit should be advanced until one of the following criteria
is met:
• maximum reach of the excavator is achieved;
• refusal on inferred/assumed bedrock; and/or
• significant caving of sidewalls due to groundwater infiltration.
Representative soil samples should be selected from each of the subsurface layers encountered during
the investigation for detailed examination and testing of select samples. Open excavations should be
logged, photographed and backfilled to grade to minimize possible tripping hazards.
Following the installation and backfilling activities, the location and elevations of the test pits are to be
determined using RTK survey equipment in the AST 77 coordinate system
This letter report is prepared for the New Victoria 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.
HEJV New Victoria Wastewater System Pre‐Design Summary Report Appendices
APPENDIX E
New Victoria Wastewater System
Archaeological Resources Impact
Assessment