Sewage spill blamed on bad circumstances, good weather

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This article was published 04/04/2022 (1306 days ago), so information in it may no longer be current.

A major spill that dumped more than 78 million litres of diluted sewage into the Assiniboine River last month would have been avoided if a construction project had ended on time, according to the City of Winnipeg’s acting director of water and waste.

“It’s unfortunate. Had the project been completed by the March 11 time frame, we wouldn’t have had to do any controlled discharge,” Cynthia Wiebe told council’s water and waste committee Monday.

Instead, this winter’s abnormally large volume of snow began to melt before the Portage Avenue interceptor sewer pipe replacement could be finished. That moisture combined with wastewater to exceed the capacity of the temporary pumping system at the site, sending 78.49 million litres of diluted wastewater into the river from March 16 to March 25.

Weather is a key scheduling factor for such projects, which prevented the pipe replacement from starting earlier, Wiebe said.

“When we’re working on a riverbank… we need to wait for the riverbank to be frozen enough to withstand heavy construction equipment and then we need to be out before the melt,” she said, noting that’s left a traditional construction window of Jan. 10 to March 15 for this type of project.

This particular job faced a long line of delays, including waits for key materials; a leaky watermain valve; blizzard-like conditions; heavy snow; inaccurate site drawings; and the disintegration of a pipe connector just as it was installed, Wiebe said.

“There were multiple circumstances or setbacks to the project that contributed to some of the delays and eventually led to some of the (sewage) discharges,” she said. “Given the quantity of snow that we had, the significant amount of snowmelt entered the system and started flooding out the construction site.”

The controlled sewage release was needed to protect the wastewater from backing up into area basements and the construction site itself, which would have created other public health risks, Wiebe said.

She stressed city staff monitored the sewage release at all hours to mitigate risk.

“We really did take every step we could to mitigate as much as possible and get this project to completion.”

When asked if the city should expect a fine from the province over the spill, Wiebe said she has not heard any mention of such an issue.

The verbal report took place amid concerns about environmental damage from the pollution.

The city and province (which regulates city sewage treatment) must do more to prevent this type of spill from being repeated, since it threatens human and animal health, said Alexis Kanu, executive director of the Lake Winnipeg Foundation.

“These rivers should be a centrepiece of the City of Winnipeg… When we treat them like toilets, when we all turn our backs on them in this way, it’s a real disservice to the gift that we’ve been given,” said Kanu, an environmental scientist.

The city should stop assuming sewage work is safe to complete in mid-March when it depends on frozen conditions to help prevent environmental damage, she said.

“(By) March 11, we have spring melt occurring in some years in Manitoba and, with climate change, that’s going to become even more problematic (to still see that date) as a day where we can be assured of frozen conditions,” Kanu said. “I think the city needs to revisit some of these long-standing guidelines. They’re not sufficient.”

The head of council’s water and waste committee said he believes the details of Monday’s presentation show the city wasn’t negligent.

“A series of calamities with parts breaking, supplies not coming in and then the drawings not being correct all combined to produce this,” said Coun. Brian Mayes.

Project timelines for sewage repairs are determined by the city, a provincial spokesperson said.

“The city has extensive knowledge on its wastewater system and is responsible for establishing appropriate timelines for this work, factoring in weather and spring run-off,” the spokesperson said Monday in an emailed statement.

The statement did not answer a question on whether the province will issue a fine or penalty for the sewage spill.

“The province does not comment on enforcement matters,” it said.

joyanne.pursaga@freepress.mb.ca

Twitter: @joyanne_pursaga