The mineral oil used as an insulator in electrical transformers was, at one time, known to contain PCBs, but the substance spilled in last week's backhoe incident does not, the environment ministry confirms.
PCBs, or polychlorinated biphenyls, were used in electrical equipment at one time because of the substance's durability and resistance to heat and light, but their use has been prohibited in Canada since the late 1970s. Last week's spill of transformer mineral oil into Horne Lake prompted speculation on social media that toxic PCBs may have been released into the water, posing a danger to the lake's aquatic population.
"Hydro One has confirmed that, as with all modern transformers, the mineral oil used is PCB-free and is not expected to be harmful to aquatic organisms," writes Gary Wheeler, Ministry of the Environment, Conservation and Parks, in response to a query by ElliotLakeToday.
The spill of an unknown amount of mineral oil happened after a backhoe working on the Hillside Drive project last Wednesday accidentally took down a hydro pole and three transformers. The oil entered a catch basin which feeds into Horne Lake, creating a visible sheen on the water. Hydro One notified the environment ministry and a GFL crew responded to undertake a cleanup operation.