A slope failure on a stormwater retention pond at Saskatoon’s landfill is at risk of damaging a nearby underground petroleum pipeline, and administration is calling for emergency repairs. In a report before their meeting next Wednesday at City Hall, Saskatoon’s Environmental Operations Manager Dan Gauthier is asking councillors to approve the transfer of $1.2 million to cover the anticipated remediation costs. Gauthier says the funds would come from the capital reserve for waste processing and have no impact on the mill rate. The lined stormwater pond, basically a massive pit lined in heavy duty black tarp, was added in 2023 when the Material Recovery Centre (MRC) was built and the landfill site was upgraded. It’s designed to manage all runoff from the MRC and the west half of the landfill itself. With the northwest slope of the pond now shifting, Gauthier writes that it’s putting pressure on the pond liner, and further degradation could pose a massive threat to the environment. “In the 1950’s, a petroleum pipeline was buried on the current MRC site and is still active today, carrying petroleum products to Saskatoon which are stored and further distributed throughout the province,” he said. “This pipeline is buried immediately adjacent to the slope that has failed and further degradation of the slope could threaten the integrity of this pipeline.” The city retained an engineering consultant to perform geotechnical modelling of the failure, borehole drilling to confirm site conditions and come up with short-term stabilization solution. According to the report, the slope is being surveyed on a regular basis to track movement and runoff is currently being diverted away from the failed area as additional water could cause the slope movement to accelerate. “Based on the geotechnical assessment, installation of steel sheet piling was identified as the preferred short-term stabilization measure. Sheet piling consists of interlocking steel sections driven into the ground to create a retaining structure that provides support to unstable soil.” This work is expected to start as soon as council approves the funding transfer. Administration says a long-term repair plan will be developed over the winter.
