Slag pile sinkholes cause for investigation

The slag piles northeast of Grand Forks sit on the edge of the Granby River; Photo, City of Grand Forks

Large crevices and sinkholes appearing in the Grand Forks slag piles along the Granby river were cause for serious investigation today.

The changes in the slag piles were noted by Pacific Abrasives Ltd. and city crews. 

"If the entire slag pile shifts and lands in the river we could see the Granby running through town on 2nd Street," said mayor Brian Taylor. 

Taking quick action, especially in light of the recent landslides elsewhere in the Kootenays, the city and Pacific Abrasives agreed to shut down operations as a precaution and to wait on a technical opinion.

A geo-technical engineer from Golder Associates Ltd. arrived Monday afternoon and reviewed the stability of the slag along with Taylor and other city staff. 

After a preliminary inspection, the city was advised that the crevices were formed as a result of underground waterways which in all likelihood have been there for some time, but now due, to excessive rain and running water, have become apparent. 

"While we don’t expect any sluffing from the slag pile properties to impact the Granby River, the situation continues to be monitored on a daily basis," added the city's chief administrative officer Lynne Burch.

The slag is the waste minerals left after extracting copper for the smelter that was the main industry for the area in the early 1900's. Pacific Abrasives uses the material for transforming into sandblasting products and city crews access the gravel pit nearby.

Pacific Abrasives and the city’s gravel pit will resume operations on Tuesday.