Workers in Saskatoon are starting to clean up contaminated soil beneath an apartment building on 33 Street West and Avenue P.

The soil underneath the 36-unit Prairie View Apartments is contaminated with gasoline from a Co-op service station across the street.

The gas came from a leak decades ago.

'Dissolved gasoline constituents'

The contamination was discovered three years ago when Federated Co-operatives Ltd. did an environmental assessment as part of an upgrade of the existing service station.

It discovered that the underground tanks at the decades-old station had leaked.

Trevor Carlson

Trevor Carlson

"A small portion of the contamination on that site managed to find its way into a sand seam that travelled pretty much underneath the midsection of that apartment building across the street," said Trevor Carlson, FCL's environmental affairs director.

"The historical fringe of the contamination had parked itself under that apartment."

Residents who live in the building knew something was up two years ago when a Regina environmental firm started drilling test holes on the front lawn.

And then — in the building's stairwell.

Ellie Konkin

Ellie Konkin

Building caretaker Ellie Konkin said they're taking it in stride.

"Nobody mentioned that we had to get out, so we're just kind of okay with it."

Carlson said the clean-up will cost between $300,000 and $500,000 and take until at least Christmas.

No one technology sufficient

The clean up is presenting a technical challenge to engineers. The object is to get the contaminated soil from underneath the apartment building without having to disrupt the lives of tenants, or tear down the building.

To accomplish that, they've set up behind the building on city land and are using a combination of vacuum pumps and air hoses.

They'll use vacuum pumps to draw out the contaminated soil, and then pump in air to accelerated the bioremediation.