Second spill linked to Scarborough subway extension fouls West Highland Creek

A second spill linked to the Scarborough subway extension has contaminated West Highland Creek, stoking concerns from local environmental stewards about the project's ongoing impact on the waterway.

The spill was reported to the City of Toronto and Ontario's Spills Action Centre on Thursday, originating from a construction site operated by Scarborough Transit Connect, the Metrolinx contractor building the extension. The material entered the storm drainage system near Lawrence Avenue E. and McCowan Road before discharging into the creek. The Ministry of the Environment, Conservation and Parks said the spilled material was non-toxic and no fish or aquatic wildlife impacts have been observed to date.

Cleanup has been completed, but remediation continues with water quality testing and hydrovac operations, followed by inspection of catch basins and creek outfalls to ensure the spill is contained. The city has not stated when that testing will finish.

This mirrors a similar spill in the same location in July, when the contractor spilled polymer-based slurry, the viscous liquid often used in construction for building foundations and drilling. Metrolinx said it will continue to hold Aecon — the joint-venture partner building the extension alongside FCC Canada Ltd. — to account for following its spill prevention plan.

Salima Pirani, lead steward with Toronto Nature Stewards at Highland Creek Park, flagged the timing: a salmon run is scheduled for Sunday, and she worries about what the spill might mean for the fish. "People don't understand that when a natural area is degraded, or when an environmental disaster like this happens, how it impacts everything downstream," Pirani said.