The federal government has announced it will join in an environmental assessment of a major expansion to a proposed southern British Columbia coal mine.
A spokeswoman for Environment Minister Jonathan Wilkinson says the decision was made after analyzing the potential of Teck Resources' Castle project to cause adverse effects within areas of federal jurisdiction.
Teck is proposing an expansion that would increase the size of Canada's largest mine for steelmaking coal by about 36 per cent.
Teck's existing mines in the area have created significant problems with selenium, a contaminant that has damaged fish life in regional rivers and spread south into the United States.
Eight interveners asked Ottawa to step in on the assessment, including First Nations on both sides of the border and the U.S. Environmental Protection Agency.
Wilkinson earlier said his department would step in on an assessment of the Vista coal project in Alberta, reversing an earlier decision.
Wednesday's Teck announcement comes as the Alberta government plans to increase coal production in the province.