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
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.
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.