Sewage leaks in past 5 years in excess of 1 trillion litres

OTTAWA — Last Wednesday, a team of people from the Lake Ontario Waterkeeper environmental group descended on the Toronto harbourfront looking for any signs the previous night’s massive, flash-flood rainfall had caused the city’s ancient combined sewer system to overflow into the lake.

They didn’t need to dip a single test tube into the water to know it had.

There, in plain sight and floating around the docks and pedestrian bridges along the waterfront of Canada’s biggest city, was a toxic stew of used condoms, plastic tampon applicators and mounds of shredded toilet paper, along with a countless quantity of other, unidentifiable solids.

When water testing was done, the levels of bacteria “were off the charts,” said Krystyn Tully, vicepresident of the national water advocacy group Swim Drink Fish.

Toronto, like the vast majority of Canadian cities, doesn’t monitor real-time data of sewage leaks into lakes, rivers or oceans. As a result, it’s unknown how much raw sewage flowed through overflow pipes when the storm overwhelmed the city’s treatment facilities.

Environment Canada does require municipal governments to report annually how much untreated waste water is spilled, but settles for calculations that are based on computer models, rather than specific data of actual events.

Data provided by the federal government shows in 2017, municipalities reported 215 billion litres of raw sewage were spilled or leaked without being treated. Enough to fill 86,000 Olympicsized swimming pools, that represents an increase of 10 per cent over the amount reported five years ago.

Over the last five years, the total amount is in excess of one trillion litres.

About two-thirds of the amount reported in 2017 was purposely released when rains overwhelmed water systems that use a single pipe for both storm sewers and waste water. When storms happen, the excess water can’t be handled by treatment plants and must be released into waterways to prevent basement backups.

The rest is usually the result of problems like power outages, system breakdowns or leaks.

The largest contributor to the national problem is British Columbia, where municipalities reported 77 billion litres of raw sewage that leaked or was spilled in 2017.