Tunnel boring to begin for project aimed at reducing sewer overflow in Toronto’s waterways

Tunnel boring is set to get underway as part of a project aimed at reducing sewer overflow in Toronto’s waterways.

Mayor John Tory, along with other city officials, spoke Saturday about the next stage of construction for the Coxwell Bypass Tunnel.

“Through this tunnel we can capture and store rain and wastewater and transport it for treatment and disinfection so clean water is released into the lake,” Tory said in a statement.

“This project is of great importance to our city and the future of our waterways.”

In older areas of the city — estimated to be about 23 per cent — sewer systems combine both rain water and sewage. During significant rainfalls, those systems often get overwhelmed, resulting in sewage overflowing into Lake Ontario.

The Coxwell Bypass Tunnel, however, is one of several connected projects aimed at ensuring water is treated before being released back into waterways.

Overflow water will be stored in the tunnel during periods of heavy rain and transferred to the Ashbridges Bay Treatment Plant before being released.

“Today we’re making history by embarking on the largest and most significant stormwater management program in the city’s history,” Tory said during Saturday’s event, adding the projects have an overall budget of $3 billion.

The Coxwell Bypass project officially got underway in 2018 and, according to the city’s website, is approximately 30 per cent done, including two shafts that are complete. Use of new tunnel boring machine, however, marks the next step of the project.

It is expected to undergo testing before starting to dig parallel to the Don River in the new year.

Officials said it can dig at a rate of at least 20 metres per day.

Tory said he has also been calling on the federal and provincial government to provide financial assistance for wastewater management projects to make them move along more quickly.

The Coxwell Bypass Tunnel scheduled for completion in 2024.

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