OTTAWA  –  At a ceremony last Friday (Nov. 20), the city celebrated the official start of operations of the Combined Sewage Storage Tunnel, a major investment to protect the health of the Ottawa River.

The event was hosted by The Honourable Catherine McKenna, Minister of Infrastructure and Communities for the Government of Canada, The Honourable Lisa MacLeod, Minister of Heritage, Sport, Tourism and Culture Industries, MPP Nepean, on behalf of the Honourable Laurie Scott, Ontario’s Minister of Infrastructure for the Government of Ontario, and Mayor Jim Watson. 

This is one of the most significant projects of the Ottawa River Action Plan, which is a roadmap to protect the river for future generations. Construction began in 2016 on the two interconnected tunnels, which total 6.2 kilometres. The tunnels intercept surface runoff and wastewater (called combined sewage), store it temporarily, send it for treatment at the Robert O. Pickard Environmental Centre, and return it safely to the Ottawa River. The project also includes 15 underground chambers and access shafts and four odour control facilities.   

 “With the CSST in operation, we have fulfilled a major goal of the Ottawa River Action Plan and strengthened Ottawa’s position as a world leader in combined sewage overflow control,” Watson said. “We are delivering on Council’s commitment to protect our precious water resources and ensure the health and vitality of the Ottawa River for future generations.” 

Now in operation, the Combined Sewage Storage Tunnel will significantly reduce the frequency of combined sewage overflows to the Ottawa River, bringing the city into compliance with Ontario Ministry of the Environment, Conservation and Parks guidelines. It will reduce the volume of combined sewage overflows to the Ottawa River by up to 43,000 cubic-metres per event – or approximately 18 Olympic-sized swimming pools – while also reducing the risk of basement flooding for approximately 7,000 residential properties in the north end of the Glebe and in Centretown. The tunnels also allow flow to be diverted from a major downtown sanitary sewer for improved inspections and maintenance on this critical infrastructure. 

 “We need to protect the health of the Ottawa River to swim, drink, fish,” McKenna said. “The Government of Canada is investing more than $62 million in this project that will reduce sewage overflows into the Ottawa River during severe weather, while greatly reducing flooding for thousands of homes in Ottawa. Canada’s infrastructure plan invests in thousands of projects, creates jobs across the country, and builds cleaner, more inclusive communities – and this project strikes very close to home.” 

The Combined Sewage Storage Tunnel is a $232.3 million investment and part of the Ottawa River Action Plan. Funding was provided by the Government of Canada, the Government of Ontario, and the City of Ottawa. The Government of Canada and Province of Ontario each provided $62.09 million. In addition, the City contributed $108 million. 

Construction commenced in 2016 to build two interconnected tunnels, totalling 6.2 kilometres, to intercept surface runoff and wastewater from the most significant overflow locations and store it until it may be treated at the Robert O. Pickard Environmental Centre and returned safely to the Ottawa River. In addition to the tunnels, construction included 15 major access shafts and four odour control facilities housing a host of instrumentation.