Regina sinkhole, caused by sewer backup, led to another sewer backup for Albert Park residents

It's been a summer of sinkholes and sewer issues in Regina.

The city's second sinkhole in just over a month opened up last week at the northeastern corner of Pasqua Street, near the Parliament Avenue intersection east of Lewvan Drive.

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The sinkhole was caused by a sewer backup in the area, according to the City of Regina, and it led to another sewer backup for many residents in Albert Park.

Multiple residents reported they had sewage spewing into their basements, as well as about fifteen centimetres of water.

The owner of a restoration company in Regina, WINMAR, said one of the houses his crew worked on had about 60 centimetres of water in the basement.

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Pat Wilson, director of water, waste and environmental services with the city, said the sewer issues are being caused largely by mud and dirt getting into the system, as well as a buildup of hydrogen sulfide gas in the pipes.

"As we've seen these extremely dry conditions over the last few years, the soil has dried out far deeper than is typical, so that creates voids in the soil," she said, noting that dry soil leads to more pressure on pipes.

"As well, we're not seeing the flushing of our lines and the dilution of the sewage, so we're seeing more corrosive sewers. There's hydrogen sulfide gas that forms in the sewers and then sits there and that does have an impact on the concrete."

Backup led to sinkhole

Wilson said city crews responded to a sewer main backup near Pasqua Street and Parliament Avenue on Thursday. They believed the problem was fixed but another sewer block developed, which led to the sinkhole.

She said repairs could take several days because sewer repairs in that area can be difficult.

"There are several different neighbourhoods where the flow comes into that particular location, into the manhole. That makes the whole issue of pumping around that, while we do a repair, very complex."

However, she said sewer services shouldn't be affected during repairs.

Wilson said the city is currently relining concrete sewer lines to make them more durable, on top of other precautions to prevent sinkholes.

"We will be doing more inspecting and exploring, looking for possible situations. It's not necessarily a trend at this point but it does concern us," she said.