Husky Energy says ground movement is the reason a section of its pipeline burst in July, leaking crude into the North Saskatchewan River and jeopardizing the drinking water of thousands downstream.
The company said a detailed report into the incident showed the sudden break was caused by “geotechnical activity” that forced a section of the pipe to buckle.
The pipeline leaked an estimated 225,000 litres of heavy oil and condensate and affected an area of about 41,500 square metres, with about 40 per cent of the spill liquid flowing into the river.
The incident forced the Saskatchewan cities of North Battleford, Prince Albert and Melfort to shut off their water intakes from the river and find other water sources for almost two months.
Husky said it has spent about $90 million responding to the spill and wrapped up shoreline clean-up efforts in October after recovering about 210,000 litres of what spilled.
Provincial regulators continue with their own investigation into the incident and will file a separate report.