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Construction Sites and Updates

Construction Sites

Map of Potential Sites

The map below identifies potential construction sites for the CSST project within the City of Ottawa. 

The legend provides additional information of the location of each site.  

Map of the CSST alignment and sites. The East-West tunnel runs through the downtown core from LeBreton Flats to New Edinburgh, and the North-South tunnel runs from Chamberlain Avenue to behind the Supreme Court of Canada.

Site 1: West End Shaft – LeBreton Flats

Site 1 is the western end of the East-West Tunnel (EWT) and the tunnel boring machine’s final exit point. Ultimately, Site 1 will house a flow diversion chamber, an access point for operations staff and large equipment, and an odour control facility. The flow diversion chamber structure will divert potential overflows from the Booth Street Sewer and Cave Creek Collector toward the EWT.

Site 2: East-West Tunnel/North-South Tunnel Intersection – Kent and Slater Streets

Site 2 is the intersection of the two tunnels at Kent and Slater Streets. This location will house an underground access shaft for inspection of both tunnels via a maintenance hole.

Site 3a: Rideau Canal Interceptor Diversion/Drop – Confederation Park

A new underground diversion chamber and drop structure will be built in Confederation Park and, ultimately, accessed via a maintenance hole. Excess flows from the existing Rideau Canal Interceptor can be diverted to the EWT at this location. 

Site 3b: Rideau Canal Regulator - Rideau Canal

Work is required on the existing Rideau Canal Regulator (which was previously constructed) in order to ensure operational efficiency of the CSST and prevent flooding as a result of elevated flow levels.

Site 3cR: Wilbrod Shaft – Cumberland Street at Wilbrod Street

This location - on Cumberland, just north of Wilbrod - will house an underground access shaft for inspection of the EWT via a maintenance hole.

Site 4

This site eliminated during the construction phase of the project.

Site 5 - EWT Outlet / Rideau River Collector RC Diversion – New Edinburgh

Site 5 will be the location of the downstream end of the EWT and connection point to existing sewer infrastructure. Four shafts, each with different functions, will be constructed, along with an odour control facility.

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Site 6: North South Tunnel Overflow/Kent Street Outfall - Ottawa River Pathway

Site 6 is the northern end of the North-South Tunnel (NST) and the exit portal for the tunnel boring machine. Here, potential overflows from the Kent Street Sewer will be diverted to the NST and monitored.  An underground connection and an improved sewer outfall will be constructed at this location.

Site 7

This site eliminated during the design phase of the project.

Site 8: McLeod Street Drop – McLeod Street and Kent Street

At Site 8, flows from the McLeod Relief Sewer will be directed to the NST via a new, underground drop shaft, ultimately accessed via a maintenance hole.

Site 9: Catherine Street Drop – Catherine Street at Kent Street

Excess flows from the Catherine Street Sewer will be diverted to the NST via an underground drop structure at this location.  An odour control facility will also be constructed at the corner of Catherine and Kent streets.

Site 10: Chamberlain Shaft – Chamberlain Avenue at Kent Street

Site 10 is the upstream end and southern extremity of the NST. This site is the main construction staging area for the NST. The shaft will serve as a means to flush the NST, and will allow operations staff and equipment to access the tunnel.

Key Definitions

Collector sewer: 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).

Diversion sewer: A conduit that conveys wastewater flows from diversion chambers to the CSST.

Diversion chamber: A structure that re-directs flows from collector or interceptor sewers to the CSST in order to prevent or minimize the volume of overflows.

Drop: A structure that conveys wastewater flows from a sewer at a higher elevation to one at a lower elevation (for example, from local high level combined sewers or a diversion sewer to the CSST).

Outfall: A structure that discharges combined sewer overflows and/or stormwater into a receiving waterbody; for the CSST the receiving waterbody is the Ottawa River.

Outlet: (in context of this project) A point of discharge from the CSST to another conduit. The CSST has two outlets; the first to the IOS at Site 5, and the second to the Kent Street Outfall at Site 6.

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

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

CSST e-newsletter

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