On March 4, 2023, CST Canada Coal Limited (CST Coal) reported to the Alberta Energy Regulator (AER) an exceedance of its daily Environmental Protection and Enhancement Act (EPEA) Approval limit of total suspended solids (TSS) in mine wastewater that was released from the Plant Site Settling Pond into the Smoky River.
Plant Site Settling Pond is an approved structure that is authorized to release mine wastewater and other streams into the Smoky River as part of CST Coal’s mine wastewater management system. Daily monitoring of this pond has continued and it has been in compliance with the daily Approval limit since the date of the incident. Since the release, CST Coal has submitted a release prevention plan to the AER to prevent a reoccurrence of this event in the future, and is actively implementing release prevention measures as they are identified in the plan, as well as ongoing and continued monitoring of the Smoky River.
CST Coal continues to cooperate with the AER and has complied with all of the regulator’s requests to date.