An investigation is underway in Saskatoon after a large quantity of raw sewage spilled into the South Saskatchewan River last month.
According to officials, the exact amount of sewage spilled is unknown, but it could be as much as 60 million litres — the equivalent of 24 Olympic-sized pools.
It happened on July 19 as heavy rains rushed through the city's sewer system.
Saskatoon's sewage treatment plant is being upgraded, and currently there's just one bar screen in place to handle the sewage. Debris plugged that screen, and so raw sewage had to be released into the river, officials said.
Sewage flowed into the river for seven hours, water treatment manager Mark Keller said.
The sewage would have been diluted by the rain, but the volume isn't known, he said.
"We are talking about a flood condition, a heavy intense rainfall event, so to put a number to that right now, we are not actually sure."
Environment officials are investigating.