Installing backup power at city’s sewage lift stations pegged at $50M

Power failures at city lift stations during wild storms last month caused 9.71 million litres of diluted raw sewage to spill into Winnipeg rivers.

But adding a backup power supply to prevent the problem at every sewage lift station would be extremely expensive and, in some cases, unlikely to prevent much pollution, city officials say.

Since the beginning of June, the city posted details of eight spills caused by power failures on its website, the largest of which dumped 2.6 million litres of diluted raw sewage from a single site on June 9.

That day’s storm pounded the city with large hail and rain, while also sparking tornado warnings, causing flooding and downing power lines.

“The storm was quite the outlier in terms of intensity. We haven’t had one of those storms in a long time. How intense that rainfall was and where it fell in the city, there (were) major power outages … That’s really kind of extreme. We had a lot of spills reported due to power outages. Hopefully, that’s not the new norm,” said Tim Shanks, director of Winnipeg water and waste.

The city is constantly assessing the condition of its lift stations, which pump wastewater for sewage treatment, including where backup power is most needed to protect the environment, said Shanks.

If outages become more frequent, plans to add backup power at lift stations with the most spills could ramp up. However, power failure is just one cause of sewage spills being routinely monitored, along with pipe conditions and other factors, said Shanks.

Currently, 13 of Winnipeg’s sewage lift stations have backup power, while it will be added at the Tylehurst Street station by next spring and the Mager Drive location by spring 2031. The city also has four standby generators and can rent more when big storms are expected.

Of the 75 lift stations in Winnipeg, only 25 have had a power failure that caused a sewage discharge since 2004, said Shanks.

“Not every lift station actually needs permanent backup power,” he said.

It’s unlikely that lift stations without a power failure-related spill in two decades would have one in the future, since power has been very reliable at those sites so far, he said.

The city estimates it would cost $50 million to install backup power at all 62 lift stations that don’t have it right now.

Officials say not all stations are in locations that have space to add the feature.

“They’re tucked away in neighbourhoods, they’re in between homes, they’re the small little … buildings at the back end of parks,” said Shanks.

For the Tylehurst lift station, the city explored using battery power but found that would cost about $2.5 million over 25 years, while an indoor gas-powered generator would cost $800,000. The city chose the latter option, said Lisa Marquardson, a water and waste spokeswoman, in a written statement.

The program to monitor lift station discharges began in 2021.

“We are now working to upgrade the lift stations in the worst conditions … Ten lift stations are identified as ‘high risk’ for discharging (untreated diluted sewage) due to power failures. We are looking to add backup power to each of these stations when they receive a full upgrade,” wrote Marquardson.

A University of Manitoba microbiologist and associate professor said it’s very important that governments closely monitor rivers impacted by the spills to determine how water quality is affected by elevated bacteria and viruses.

“As the summer (continues), many people may get ready to enjoy the aquatic environments here in Manitoba …there could be viruses that could affect humans and aquatic life,” said Miguel Uyaguari-Diaz, noting children and immunocompromised people would be most at risk.

Monitoring is key to fully understanding the effects of the diluted raw sewage being released, he said.

“It will impair some of the aquatic life because more organic matter will be present in this aquatic environment. It will create algal blooms, it will also … deplete the oxygen that is present in the water that some aquatic life needs,” said Uyaguari-Diaz.

Reducing this particular sewage spill risk is complicated, since lower income Winnipeggers might not be able to afford the rate hikes required to raise $50 million to add backup power at all sewage lift stations, the professor said. He noted the city is pursuing many other sewage mega projects that have boosted water and sewer rates.

He noted the ongoing $3.1-billion upgrade of the North End sewage treatment plant, which taxpayers are already paying for, is critical to ensuring Winnipeg can properly treat its sewage as its population grows.

Coun. Ross Eadie (Mynarski), chairman of the water, waste and the environment committee, said the city’s work to regularly monitor all 75 lift stations is becoming more important, as climate change is linked to more severe storms.

“I’m quite confident that they’re looking at it,” said Eadie (Mynarski).

joyanne.pursaga@freepress.mb.ca

X: @joyanne_pursaga