Sewage spill into Assiniboine largest in five years

Cold snap prevented worse, but activist still fears health impact


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A major sewage spill dumped more than 78 million litres of diluted sewage into the Assiniboine River.

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A major sewage spill dumped more than 78 million litres of diluted sewage into the Assiniboine River.

“It is the largest overflow (incident) in at least five years,” city spokesperson Lisa Marquardson wrote in a statement.

A total of 78.49 million litres of wastewater mixed with snow melt was released into the river when a temporary sewage pump— in place while the city replaces a Portage Avenue interceptor sewer pipe — was unable to keep up with the flow.

A total of 78 million litres of wastewater mixed with snow melt was released into the river when a temporary sewage pump was unable to keep up with the flow. (Mike Deal / Winnipeg Free Press files)

As a result, diluted sewage was released between March 16 and March 25.

The spill ended around 2:15 a.m. on Friday, Marquardson said.

“The controlled release of wastewater related to this project ceased at that time due to the drastic change in weather conditions,” said Marquardson.

The city previously noted this winter’s abnormally large volume of snow began to melt before the project ended and, combined with wastewater, exceeded capacity of the temporary pumping system.

The temperatures plummeted to winter-like levels on the weekend.

Without the controlled discharge into the river, city officials say the sewage would have backed up into basements and the construction site, creating public health and safety risks.

However, the spill itself also threatens human health and the environment, so governments should face consequences for such spills and set higher standards to prevent them, said the head of the Lake Winnipeg Foundation.

“This sewage, it’s full of E. coli, fecal coliform. It’s got phosphorus in it… I think Winnipeggers are completely disgusted that this is happening at all. It’s (untreated) sewage in a natural habitat,” said Alexis Kanu, an environmental scientist who is the organization’s executive director.

For example, Kanu said the project’s assumption that frozen conditions would help prevent environmental damage, even though the project was expected to wrap up in March, warranted more scrutiny.

“The onus is on the province to back up its environmental regulation with some consequences for the proponent of this project, which in this case is the city. At the very least, I would like to see… a full accounting of the impacts of this project (from the province) and how spills like this… will be prevented in the future with better planning,” she said.

In an emailed statement, a provincial spokesperson noted the city has provided daily updates on the sewage release to the province. But the statement did not directly answer whether a penalty is expected.

“The province is reviewing all of the information provided by the City of Winnipeg,” the spokesperson said.

The head of city council’s water and waste committee says the spill will be discussed during his committee’s next meeting, on April 4.

Coun. Brian Mayes said he expects to seek details on whether the sewage discharge could have been prevented.

The spill highlights the need to invest in sewage treatment, he said, noting combined sewer overflows dump billions of litres of diluted sewage into local waterways each year.

“They’re all nasty spills, they’re all unpleasant… It sort of reinforces the point we were trying to make with increasing the (combined sewer overflow reduction) budget,” said Mayes.

Combined sewer overflows occur when heavy rain or snow overwhelms older sewers that collect precipitation and wastewater in a single pipe, causing them to overflow into rivers. About 5.6 billion litres of diluted sewage flowed into local waterways through combined sewer overflows in 2020, the most recent data available.

The city recently voted to increase its investment to reduce these overflows from $30 million to $45 million per year between 2024 and 2027. The overall plan to reduce combined sewer overflows is expected to cost $2.3 billion.

The construction-related sewage spill was not a combined sewer overflow.

By Saturday afternoon, the pipe construction project had been almost completed, Marquardson said.

While residents have complained about seeing and smelling apparent sewage in Omand’s Creek, Marquardson said the creek was “minimally affected and was spared most of the spill.”

Twitter: @joyanne_pursaga

Joyanne Pursaga

Joyanne Pursaga

Born and raised in Winnipeg, Joyanne loves to tell the stories of this city, especially when politics is involved. Joyanne became the city hall reporter for the Winnipeg Free Press in early 2020.


Updated on Tuesday, March 29, 2022 6:37 AM CDT: Replaces deck

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