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Project Background - CSST

Project Overview

Background and Council Reports

The CSST project is the result of an extensive planning process, including an Environmental Assessment study. During this study, a wide range of conceptual alternatives were considered, a formal screening and evaluation process was developed and followed, and a preferred alternative was identified. This process also provided a range of public consultation opportunities, including Public Open Houses held as part of the Ottawa River Action Plan (ORAP) in late 2009, as well as several more public consultations in 2010 and 2012. The results of the Environmental Assessment study were received by Committee and Council in 2013 (include link: City Council – ORAP Status Update and CSST Environmental Assessment).

Recognizing the importance of the health of the Ottawa River, Council and Committee confirmed the project as a Term of Council Strategic Initiative (SI) in the City’s 2015-2018 City Strategic Plan on July 8, 2015.

Further to a procurement process, Dragados Tomlinson Joint Venture was selected to construct the Construction of the Combined Sewage Storage Tunnel. Implementation officially began in the summer of 2016 at Site 10 (intersection of Kent Street and Chamberlain Avenue), which is the location of the portal for the North-South Tunnel (NST) where the Tunnel Boring Machine will be launched in 2017.

As the project moves into implementation, efforts will continue to ensure that residents, the public and all key stakeholders are informed and engaged throughout construction and in advance of any major construction activities.

In addition to this webpage, residents looking for additional information on the CSST project can access:

Regularly distributed e-newsletter with updates on construction activities, impacts, and progress. Residents can sign up to receive updates automatically at Ottawa.ca/esubscriptions.

Email address CSST@ottawa.ca (link sends e-mail) for inquiries

To date, three public information sessions have been held in advance of site specific construction activities: one at Site 10 (June 27, 2016), and two for Site 5 (October 27 and November 16, 2016). Further sessions are anticipated as construction progresses, and dates and locations will be posted on the website.

Environmental Study Report (ESR) – Addendum – 3 April 2014

Combined Sewer Overflow (CSO) Storage Environmental Assessment and Functional Design Project

Like most municipalities, the City of Ottawa has combined sewers in older areas of the City, which transport sewage and stormwater runoff in the same pipe. These older systems were designed to overflow when it rains to prevent flooding and basement backups.

The City of Ottawa has completed an Environmental Assessment (EA) and Functional Design to identify and develop a preferred solution that will provide additional storage of combined sewage in the combined sewer area and thereby reduce combined sewer overflows (CSOs) to the Ottawa River. This is one of seventeen projects included in the City’s Ottawa River Action Plan. It is being conducted under the Municipal Class EA process.

When implemented, the project will help to:   

  • Reduce CSOs from the Ultimate Combined Sewer Area;
  • Improve water quality in the Ottawa River; and,
  • Become fully compliant with Ministry of Environment’s Procedure F-5-5

Why is the project needed?

Currently, CSOs to the Ottawa River do not meet all provincial CSO control targets. The City’s Combined Sewer Area Pollution Prevention and Control Plan (PPCP) has identified that storage within the Ultimate Combined Sewer Area is the most cost effective way of further reducing CSO beyond the minimum regulatory requirements.

The Process

This project followed Schedule C project of the Municipal Class Environmental Assessment process. Public consultation was carried out throughout the project, including three series public open houses held on the following dates:

  • Spring of 2009
  • June 2010 and
  • June 2012

The Environmental Study Report (ESR) has been completed and has been placed on record January 25 2013 for public and agency review for a 30-day period. Subject to comments received as a result of this Notice and the receipt of necessary approvals, the City intends to proceed with the detailed design of this project in 2013.

The Environmental Study Report (ESR) is available on-line; alternatively, hard copies can be reviewed at the following branches of the Ottawa Public Library:

  • Hazeldean: 50 Castlefrank Road
  • Ruth E. Dickinson: 100 Malvern Drive
  • Main: 120 Metlcalfe Street
  • Orléans: 1705 Orléans Boulevard

Interested persons are encouraged to review the ESR and provide comments within the 30 day review period to the City of Ottawa Project Manager listed below. If after consulting with the City of Ottawa, you have unresolved concerns, you have the right to request the Minister of the Environment (135 St. Clair Avenue West, 12th Floor, Toronto, Ontario, M4V 1P5) to “bump-up” (i.e. make a Part II Order for) this project. A Part II Order may lead to preparation of an individual environmental assessment. A written copy of the “bump-up” request must be received by the Minister of Environment by Monday 25 February 2013 at the address indicated above. A copy of the request should also be sent to the City of Ottawa Project Manager at the address indicated below. If there are no outstanding concerns after Monday 25 February 2013, the project will be considered to have met the requirements of the Class EA and the project will proceed with detailed design and construction as presented in the planning document.

Information will be collected in accordance with the Freedom of Information and Protection of Privacy Act.

Next Steps in the Process

With the exception of components of the project to be built as part of the LRT (see below), the next steps for the Project are

  • Final design, tendering and Contract Award of the preferred solution Spring 2013 to Fall 2015
  • Construction of the preferred solution Winter 2016 to Summer 2019
  • Commissioning of the storage tunnels Fall 2019

Since part of the CSST alignment is located under or immediately adjacent to the LRT alignment in Lebreton Flats, construction of a few components of the Project located within the vicinity of the LRT alignment are being coordinated with construction of the LRT.

For more information

For additional information, please visit: ottawa.ca/CSST

Public information session – 27 June 2016

Combined Sewage Storage Tunnel (CSST) project
Site #10: Kent Street / Chamberlain Avenue

Monday, June 27, 2016
4:30 to 6:30 pm
St. Giles Presbyterian Church
174 First Avenue, Ottawa, ON

The City of Ottawa invites you to a Public Information Session on the Combined Sewage Storage Tunnel (CSST) project, one of the most important projects of the Ottawa River Action Plan to improve the health of the river. The CSST project will include the construction of two tunnels: an east-west tunnel (EWT) through the downtown core from LeBreton Flats to New Edinburgh Park, and a north-south tunnel (NST) along Kent Street from Catherine Street to existing infrastructure, just behind the Supreme Court.

At the Public Information Session, you will be provided with background information on the CSST project, as well as details on specific construction activities and impacts for Site 10 at Kent Street and Chamberlain Avenue. Representatives from the City and the consultant team will be available to discuss the project and answer your questions.

Why: The CSST will greatly reduce the frequency of sewage overflows during storms from entering the Ottawa River, and will help protect the river.

Where: To complete this project, there will be several surface construction sites and continuous underground tunneling operations throughout the downtown. A key surface construction site for the CSST will be located at the intersection of Kent Street and Chamberlain Avenue, on land formerly used for the Kent Street Rapid Bridge Replacement. The Contractor may also use the former school board site along Chamberlain between Bronson and Percy.

What: An access shaft will be constructed at this location to launch the tunneling operation for the North-South Tunnel. When complete, a permanent access point to the underground tunnel will remain at this site.

When: Construction will begin as soon as July 2016 at Kent Street and Chamberlain Avenue and is expected to last until fall 2018 at this location. Overall CSST construction will continue at various sites throughout the City until the end of 2019, with the CSST becoming operational mid-2020.

For further information about the information session or the project overall, please:

Accessible formats and communication supports are available upon request.

Environmental Study Report (ESR) – Addendum – 3 April 2014

City of Ottawa
Class Environmental Assessment
Combined Sewage Storage Tunnel
Notice of Filing of Addendum

In February 2013, the City of Ottawa completed a 'Schedule C' Class Environmental Assessment (EA) to develop a preferred solution and functional design for additional storage of combined sewage in the ultimate combined sewer area of Ottawa.  In 2013, Combined Sewage Storage Tunnel (CSST) Environmental Study Report (ESR) was completed.  The preferred design of the CSST consists of an east-west tunnel (EWT) through the downtown core from LeBreton Flats to New Edinburgh Park and a north-south tunnel (NST) along Kent Street from Catherine Street to the existing outfall north of Wellington Street.  The 2013 ESR concluded that the preferred design for the NST would include a construction staging area in St. Laurent Square.

After consultation took place during preliminary design of the CSST in 2014, it was determined that the CSST could be extended south to Chamberlain Street for an alternative construction staging area for the NST.  The resulting change in the preferred construction staging area requires additional property.  An addendum is required to evaluate the potential environmental implications.

Key Plan for the Combined Sewage Storage Tunnel (CSST) Environmental Assessment Addendum [ PDF – 1.05 MB ]

By this Notice, the Addendum is being placed on the public record in accordance with the requirements of the Municipal Engineers Association Municipal Class Environmental Assessment (2000, as amended 2007 and 2011).  Please note that only the changes proposed in the Addendum are open for review.

A copy of the Addendum report, and the 2013 ESR, will be available for viewing at the following locations.  Requests for translation for this report should be forwarded to Randy Dempsey at 613-580-2424, ext. 14102.

Environmental Study Report (ESR) – Addendum
City of Ottawa, Client Service Centre: 110 Laurier Avenue West 
Ottawa Public Library, Hazeldean: 50 Castlefrank Road
Ottawa Public Library, Ruth E. Dickinson: 100 Malvern Drive
Ottawa Public Library, Main: 120 Metcalfe Street
Ottawa Public Library, Orléans: 1705 Orléans Boulevard

The 30-day public review period begins April 3, 2014. Written comments may be submitted until May 5, 2014 to:

Randy Dempsey, Project Manager
Infrastructure Services Dept.
100 Constellation Cres.
Ottawa, ON  K2G 6J8
Phone: 613-580-2424 ext 14102
Fax: 613-560-6064
E-mail: Randy.Dempsey@ottawa.ca

If concerns arise during the prescribed review period that cannot be resolved through discussions with the City of Ottawa, a person or party may request that the Minister of Environment make an order for the project to comply with Part II of the Environmental Assessment Act (referred to as a Part II Order).  This request must be received by the Minister, at the address listed below, prior to May 5, 2014.  A copy of the request must also be sent to the City of Ottawa at the address listed above. If no request is received on or before the end of the review period, the City will proceed with detailed design and construction as presented in the Addendum.

Minister of the Environment
77 Wellesley Street West
11th Floor, Ferguson Block
Toronto, ON M7A 2T5

This Notice issued April 3, 2014.

Information will be collected in accordance with Ontario’s Freedom of Information and Protection of Privacy Act.  With the exception of personal information, all comments will become part of the public record.

Executive Summary

This addendum to the 2013 Combined Sewage Storage Tunnel (CSST) Environmental Study Report (ESR) has been prepared to revise the previous recommended alternative for the staging area and launch site of the north-south tunnel (NST).  During preliminary design of the CSST, consultation with PWGSC identified potential conflicts for the original (as documented in the ESR) preferred alternative in terms of construction schedule and space requirements at St. Laurent Square immediately south of the Supreme Court of Canada.

The revised recommended preferred location for the staging and launch site for the NST is a land parcel owned by the Ministry of Transportation (MTO) at 605 Bronson Avenue.  Using this site will require the NST to be extended by approximately 625 m along Chamberlain Avenue on the south side of Highway 417.  However, the site is large enough to accommodate both tunnel launch staging and launch operations without the need for remote staging areas.  The site will be available by the start of 2015 and will be returned to the MTO by the start of 2018 in order to coordinate with other planned projects in the area.

Despite the additional costs involved with extending the NST, this option is similar in overall cost as compared to the previously recommended option.  The NST extension effectively leads to cost savings through the elimination of other planned works.  The NST extension will allow significant sanitary and storm sewer projects in the area to be either deferred or eliminated completely.  This results in cost savings and future flexibility in routing the sewer systems.

It is recommended that the City proceed with using the Chamberlain Avenue site as the staging and launch site for the NST construction.  This will require additional geotechnical and environmental studies as well as reaching an agreement with the MTO regarding land use and schedule.  This site provides greater advantages over the other options identified.

Open House June 2010

Open Houses have been held in March/April of 2009 to present the study process, evaluation criteria and methodology, and the alternative solutions being considered, as well as provide the public with an opportunity to discuss the study with the study team and provide input and comment.

 

A second round of Open Houses have been arranged to present:

  • A short list of alternative solutions
  • Evaluation of these alternative solutions
  • The recommended Preferred Alternative Solution

Consultation (PDF version 709 KB)
Evaluation Alternative Solutions All (PDF version 1.1 MB)
Evaluation Alternative Solution Shortlist (PDF version 1.1 MB)
Recommended Preferred Solution (PDF version 350 KB)
Next Steps (PDF version 861 KB)


East

Tuesday June 15, 2010

6:30 to 9 p.m.

Presentation at 7 p.m.

Shenkman Arts Studio, Music Studio

245 Centrum Boulevard, Orléans

 

Central

Wednesday June 16, 2010

6:30 – 9 p.m.
Presentation at 7:00 p.m.
Montgomery Legion 351, Upper Hall

330 Kent Street

 

Public comments are welcome throughout the study and there will be several opportunities to learn more during the course of the study. All comments received will be collected in accordance with the Act, and (with the exception of personal information) will become part of the public record.

Open House March/April 2009

The City of Ottawa is conducting an Environmental Assessment (EA) and Functional Design to identify and develop a preferred solution that will provide additional storage facilities in the combined sewer area and thereby reduce combined sewer overflows (CSOs) to the Ottawa River.  This project has been identified as a preferred alternative under the Ottawa River Action Plan to become fully compliant with provincial Procedure F-5-5.

 

The Process: This project is being planned as a Schedule C project in accordance with the requirements of the Municipal Class Environmental Assessment, 2007, which is an approved process under the Environmental Assessment Act.

 

Public Open Houses have been arranged to present the study process, evaluation criteria and methodology, and the alternative solutions being considered, as well as provide the public with an opportunity to discuss the study with the study team and provide input and comment.

 
Introduction (pdf 55 KB)
Project Overview (pdf 59 KB)
Municipal Class Environmental Assessment Process (pdf 68 KB)
Consultation (pdf 55 KB)
Glossary of Terms (pdf 134 KB)
What Causes Combined Sewer Overflows? (pdf 198 KB)
Existing Conditions (pdf 148 KB)
Evolution of Ottawa’s Combined Sewer System (pdf 156 KB)
Alternative Solution 1 – Storage Tanks (pdf 306 KB)
Alternative Solution 2 – Short Storage Tunnels – part 1 (pdf 353 KB)
Alternative Solution 2 – Short Storage Tunnels – part 2 (pdf 360 KB)
Alternative Solution 3 – Long Storage Tunnels (pdf 343 KB)
Alternative Solution 4 – Tank/Tunnel Hybrids (pdf 428 KB)
Alternative Solution 5 – Dunker’s System (pdf 228 KB)
Evaluation Methodology (pdf 47 KB)
Evaluation Criteria (pdf 63 KB)
Next Steps in the Project (pdf 43 KB)

Central

Tuesday March 30
6:30 – 9 p.m.
Presentation at 7:00 p.m.
Tom Brown Arena Hall (2nd Floor)
141 Bayview Rd.

 

East

Thursday April 1

6:30 – 9 p.m.
Presentation at 7:00 p.m.
Bob MacQuarrie Recreation Complex: Hall A
1490 Youville Dr., Orléans

 

Public comments are welcome throughout the study and there will be several opportunities to learn more during the course of the study. All comments received will be collected in accordance with the Act, and (with the exception of personal information) will become part of the public record.


Open house presentation (27 October 2016)

Welcome

The CSST project will include the following:

  • An east-west tunnel (EWT) through the downtown core from LeBreton Flats to New Edinburgh Park
  • A north-south tunnel (NST) along Kent Street from Catherine Street to existing storm sewer outfall at the Ottawa River north of Wellington Street
  • Support facilities, such as odour control buildings

The tunnels will be a total length of 6  kilometres and will be approximately 10 to 31  metres below surface level.  The inside diameter of the finished tunnel will be 3 metres.

Aerial photo [ PDF – 456 KB ]

Overview of CSST project

Background

The Ottawa River Action Plan (ORAP) is a long-term strategy to improve stormwater management and to enhance the health of the Ottawa River through 17 water infrastructure projects. The CSST is one of the most important projects of the ORAP.

Benefits

The CSST will greatly reduce the frequency of overflows from entering the Ottawa River.

The CSST will hold up to 43,000m3 of combined sewage during major rainfalls. Up to this volume of combined sewage will be held in the CSST until after the rain event. It will then be treated at the treatment plant and returned safely to the Ottawa River.

Additional benefits of the CSST project include:

  • Reducing the risk of basement flooding for several low-lying lands in the Glebe/O’Connor area
  • Increasing operational flexibility and redundancy to major collector sewers in the downtown

Existing conditions

Combined Sewer Overflows (CSOs) to the River originate from the sewer shed serviced by the Interceptor-Outfall Sewer (IOS) that services a population of 350,000. This one pipe conveys wastewater from a 107 km2 area to the Robert O. Pickard Environmental Centre for treatment. When the IOS or collector sewers reach capacity under wet weather conditions, they can cause overflows (CSO) to the Ottawa River. A key objective of the Ottawa River Action Plan is to minimize overflows to the River.

Ottawa’s combined sewer system

Present

This diagram shows how the control system uses sensors to maximize flow to the sewage treatment facility. With this system, we can capture the flow from a bigger storm that would have caused an overflow in the past.

A diagram showing how the control system now uses sensors to maximize flow to the sewage treatment facility.

Future with CSST

This diagram shows that during large rainfall events, excess wet weather flow is sent to the combined sewage storage tunnel.  Once the event has passed, the stored water is transferred to the interceptor sewer and treatment facility.

A diagram showing how during a large storm, after the implementation of the CSST, excess rain water will be sent to the new tunnel to be stored until it can be treated.

Planning and design

Work completed

To date, the City has completed an Environmental Assessment study and detailed design of the CSST project.

Timelines

The CSST is a Term of Council Strategic Initiative and one of the most important projects of the Ottawa River Action Plan (ORAP). Below is a summary of important milestones to date:

  • November 2009: CSST Environmental Assessment is initiated through ORAP
  • February 2010: ORAP and service levels for CSOs approved by Council
  • September 2011: ORAP Year One Update Report outlines the status of the 17 ORAP projects, including the CSST, Project 3 – CSO Storage for Ultimate Combined Sewer Area (UCSA). approved by Council
  • February 2013: CSST Environmental Assessment completed, with summary of the options reviewed and the preferred alternative recommended
  • August 2013: Design of CSST commences
  • April 2014: CSST EA Addendum filed with evaluation of alternative NST construction staging area on Chamberlain Street
  • Summer/Fall 2015: The City initiates property negotiations for the CSST
  • December 2015: CSST tendered for construction

Consultation

To date, nine public open houses have been held throughout the City to support the CSST Environmental Assessment study.

Next steps and project communications

Thank you for coming to our open house.

If you have any questions about the CSST Project, please feel free to ask any City or design team representatives present.

The City will keep residents updated through a variety of information tools, including:

  • Regularly distributed e-newsletter with updates on construction activities, impacts, and progress. Residents can sign up to receive updates automatically at Ottawa.ca/esubscriptions.
  • Webpage Ottawa.ca/CSST with information on the overall project including updates
  • Email address CSST@ottawa.ca for inquiries

Comments received may become part of the public record. Information will be collected in accordance with the Freedom of Information and Protection of Privacy Act.

Definitions

Collector sewer: A conduit that receives sewage and/or stormwater from local sewers. A main conduit that receives sewage and/or stormwater from the local sewer system serving a defined serviced area such as a neighbourhood or district. Acting as the main spine of a sewer system, collector sewers in the City of Ottawa generally range from 750 mm in diameter to 2100 mm in diameter (or larger in some cases). 

Design year: The meteorological and flow conditions used as the basis for designing the facilities. In Ottawa, the Ontario Ministry of Environment and Climate change has accepted rainfall conditions measured in 1980 as representing the “design year” because it had “average” wet weather patterns for engineering design purposes.

Interceptor Outfall Sewer (IOS): The primary conduit through the City’s downtown core that captures the wastewater flow from the collectors and combined sewers and conveys it to the wastewater treatment plant, the Robert O Pickard Environmental Centre (ROPEC).

Odour control facility: A building and system for the collection and treatment of odorous air from the CSST.

Real time control: An automated or manually operated system that adjusts the operation of facilities in response to online measurements in the field.

Flow regulator: A structure that directs and controls flows in the sewer system.

Shaft: An access point from the surface to an underground facility that allows for construction and/or inspection and maintenance of this or other underground facilities, such as the CSST.

Wet weather event: A period of rainfall or snow melt that results in stormwater being captured and conveyed in the sewer system.

Site 5 – What’s happening

Map of CSST [ PDF – 333 KB ]

Construction has begun at Site 10. Site 5 (Stanley/New Edinburgh Park) will be occupied from March 2017 to October 2019. The sites are as follows:

  • Site 1: West End Shaft – Lebreton Flats
  • Site 2: EWT/NST Intersection – Kent and Slater Streets
  • Site 3a: Rideau Canal Interceptor Diversion/Drop – Confederation Park
  • Site 3b: Rideau Canal Regulator – Rideau Canal
  • Site 3c: Nicholas Street Shaft – Nicholas Street
  • Site 4: St Patrick Shaft – York and Cumberland Streets
  • Site 5: EWT Outlet / RRC Diversion – New Edinburgh Park
  • Site 6: NST Overflow and Kent Street Outfall – Ottawa River Parkway
  • Site 7: (Eliminated)
  • Site 8: McLeod Street Drop – Kent and McLeod Streets
  • Site 9: Catherine Street Drop – Kent and Catherine Streets
  • Site 10: Chamberlain Shaft – Kent and Chamberlain Streets

Staging areas

The Contractor will have available the use of two areas:

  • Stanley Park will be the primary construction area and will have a permanent access point to the CSST.
  • The intersection of Queen Victoria Street and River Lane will be a second construction area to connect the CSST to the existing Rideau River Collector overflow sewer.

Construction activities and schedule

Stanley Park
  • Temporary advance activities commenced in October and November of 2016 with installation of underground conduits, archaeological investigations and locating the IOS.
  • Tree removal may start in early 2017—Construction work will begin in spring 2017 with installation of fencing and trailers.
  • A 13-metre diameter shaft will be excavated to launch a tunnel boring machine (TBM); the TBM will be brought to the site and placed in the bottom of the shaft to excavate the tunnel.
  • After the tunnel is completed, an access chamber will be constructed within the shaft to allow for future maintenance of the CSST.
  • The existing biofilter will be removed and a new odour control facility will be constructed.
  • Work is scheduled to commence in March 2017 and be completed and the site restored by fall 2019.

Stanley Park staging plan [ PDF - 950 KB ]
Stanley Park plan and profile [ PDF - 166 KB ]
Stanley Park restoration plan [ PDF - 565 KB ]
Stanley Park proposed odour control facility [ PDF – 947 KB ]

Queen Victoria Street and River Lane
  • Work will begin with installation of fencing and signs.
  • A 6.5-metre by 6.5 m shaft will be excavated to construct a diversion chamber and access shaft.
  • Work is scheduled to commence in March 2017 and be completed and the site restored by March 2018.

Queen Victoria Street and River Lane [ PDF - 461 KB ]

Queen Victoria Street and River Lane - Projected Construction Sequencing Summary

Site 5c (Rideau River Collector - Overflow Diversion Chamber - At intersection of River Lane & Queen Victoria)
Task Start Date  End Date 

Duration

Details of Work  Expected Noise/Truck Levels
Utility Relocation Mid-February 2017

Early March 2017

2-3 weeks

Relocation of communication lines by the utility companies from above-ground to underground. 

Modest noise

Modest trucking
Traffic Control, Hoarding/Fencing, Site Setup, Utility Relocation and Temporary Sewer Bypass

March Early 2017

Early May 2017 8 weeks Site setup activities, including installation of the fencing and relocation of utilities and sewers as required.  Modest noise and trucking (delivery of fences/piping, hauling away of some material excavated for these relocations, etc).

Modest noise

Modest trucking
Shoring Early May 2017 Late May 2017

2-4 weeks

Includes driving shoring piles into the soil down to the rock elevation and line grouting to permit excavation of soils inside the shored area while supporting the surrounding areas. Installing the shoring will generate some noise - limited to daytime.  Modest trucking - limited to hauling shoring material and it is possible that some small volume of soils may be hauled away.

Loud noise driving sheet piles

Modest trucking

Soil Excavation

Late May 2017 Late May 2017 1-2 weeks Once shoring is installed, soil material will be excavated and trucked away (maybe 3 trucks per hour - small volume). The same frequency of empty trucks would also return to the site.

Modest noise

Heavier trucking

Rock Excavation

Late May 2017

Late July 2017 

8 weeks

Rock excavation will involve drilling, controlled blasting, hoe-ramming, shotcrete and bolt installation, as well as trucking away excavated rock.  Trucking frequency will be low as rock removal is a slow operation compared to earth removal. 

Loud noise resulting from hoe-ramming and rock handling.Modest trucking

Micro-Tunneling of Diversion Sewer (5b to River Lane)

Early August 2017

Early October 2017

8-10 weeks

Includes installation of tunneling equipment, pilot hole tunneling, back reaming along that pilot hole, and finishing the grouting. The back reaming operation (which consists of enlarging the smaller pilot hole to the size required for the sewer) is expected to produce the most trucking as it generates spoils (crushed rock) to be hauled away, and will last approximately 5-6 weeks. For this section of the diversion tunnel, it is proposed by the contractor that these reaming spoils be extracted from the shaft located that the intersection of River Lane / Queen Victoria - to be confirmed. Could fill four trucks per day at its peak.

Some modest noise associated with motor for auger

Modest trucking
Construction of Chambers (once micro-tunneling complete)  Early October 2017 Early February 2018 16-18 weeks (4 months)

Construction of chambers includes the following components: structure floor, walls and roof construction, installation of weir, ladders and steps, demolition of section of existing overflow sewer, new connections, backfill and removal of shoring. Materials and concrete being delivered to site as required. This phase includes backfill around the chamber, estimated to generate 3-4 trucks per hour hauling backfill material to the site and the same frequency of empty trucks leaving the site - over a period of approximately 1-2 weeks in late January / early February. Other trucking would include concrete trucks during the pours.

Modest noise

Heavier trucking during backfill (1-2 weeks), modest otherwise

Grading and Rough Reinstatement Early February 2018 Early March 2018 4 weeks Grading of the surface, base-coat paving, curbs, sidewalks, rough grading of landscaped areas to prepare for sodding later in the spring (since weather will not permit sodding at this time). Opening of the intersection.  Heavier trucking will be during delivery of granular material for road construction (3-4 trucks per hour for a week or so).

Modest noise

Heavier trucking for 1-2 weeks, otherwise modest

Post-Construction Final Reinstatement Early May 2018 Mid May 2018

1-2 weeks

Once weather is warmer, application of final layer of pavement and placement of sod and plantings. No long-term roadway impact as top-lift pavement is expected to be completed in a single day.

Modest noise

Modest trucking

Important Notes:

1. This table should be considered to be a living document and presents a best estimate based on the contractor's submitted construction schedule and the project team's general experience with similar activities.  The contractor will be required to submit detailed schedules and management plans prior to undertaking this work.

2. All work at Site 5c (River Lane / Queen Victoria) is limited to daytime activities as defined in the City's Noise Bylaw (7:00AM-10:00PM).  No nighttime work is currently permitted at this site.  Contractor may submit a special request for a specific task that is impractical to be completed during daytime, but it would need to be submitted for review and approval by the project team and Councillor as it is not currently permitted.            

Site 5 - Construction impacts

Construction activities will have the potential to impact businesses and residents along the corridor and the adjacent community. The following construction impacts may be expected:

  • Closure of the Queen Victoria / River Lane intersection
  • Conversion of River Lane to two way traffic between Queen Victoria and Keefer and between Queen Victoria and Union Street
  • Temporary closure of the Rideau River Eastern Pathway between Union and Stanley with alternate pathway routes within Stanley Park
  • Tree removal in Stanley Park
  • Temporary loss of use of park space
  • Temporary closure and diversion of pathways
  • Construction traffic to and from staging areas
  • Construction noise and dust
  • Localized vibrations as the tunneling operations pass in close proximity to homes

Construction management requirements have been included in the design and tender. A vibration/seismic monitoring program will track surface level vibrations as the tunnel boring machine moves across the City.

A Noise By-law Exemption is in place to allow work on the CSST tunneling to proceed 24 hours per day, 7 days per week.

Project funding and partners

  • The total project cost for the CSST is $232 million and funding has been approved by City Council through the budget process.
  • The City of Ottawa has contributed $108 million. 
  • The Government of Canada and Province of Ontario have each committed $62.09 million towards the project. 
  • On March 23, 2016, Council passed a motion to approve these funding agreements.

Project team

  • Stantec Consulting Ltd., CH2M and Golder Associates are working with the City on the design and contract administration of the CSST project. 
  • Dragados Tomlinson Joint Venture has been selected as the construction team to build the CSST.