THUNDER BAY — A concrete tunnel under the McKellar River that allowed coal to be delivered to the Ontario Power Generation thermal plant on Mission Island has been decommissioned, and is slowly filling with water.
Thunder Bay Terminals shipped fuel on a conveyor belt through the tunnel from its bulk facility on McKellar Island.
Built in 1963, the generating station was idled in 2014 when the provincial government phased out coal-fired electricity, It was subsequently converted to burn advanced bio-mass, but this summer OPG and the Independent Electricity System Operator announced plans to demolish it.
Some of the land the tunnel crossed on Mission Island was leased from the City of Thunder Bay. Thunder Bay Terminals didn't renew the lease when it expired a year ago, and since then has been decommissioning the infrastructure.
The conveyor system and sump pumps have been removed, access points have been sealed, and the tunnel is being allowed to fill naturally with groundwater.
A spokesperson for the City of Thunder Bay Realty Services department says there were no environmental concerns related to decommissioning.
The provincial government was the lessor of the land the tunnel crossed under the river, and provincial officials prescribed the method for deactivating it.
However, Realty Services property agent Peder Olsen said the tunnel "will remain in place as a possible future industrial asset."
Olsen said if it's ever needed for another purpose, the tunnel can be drained.