MONTREAL—A major environmental clean-up is under way near St-Jerome after electric transformers leaked potentially toxic chemicals along Highway 15 on Thursday.

Environmental clean-up crews quickly contained the spill and put up sandbag barriers around sewers and a nearby river.

Officials say there  is no risk to the local population as they estimated a few hundred litres of oil—potentially contaminated with PCBs—may have escaped.

The transformers were en route Thursday from Pointe-Clare to a scrap metal recycling plant east of St-Jerome when a police officer noticed liquid leaking from the trailer and stopped the driver near Ramp 117.

The highway entrance was re-opened at 2 a.m. Friday, and Exit 45 closed again on Friday at 10 a.m. to continue cleaning the area. The entrance will close again on Monday for the clean-up to continue.

Denis Arsenault of Transport Quebec said the pavement in the area may be excavated to ensure it is clean.

Officials say tests will be done for PCB levels and the soil will be decontaminated. The company transporting the transformers will be investigating.