Experts warn road salt piles could harm waterways, drinking water

Experts warn that road salt from melting snow piles can contaminate waterways, harm fish and seep into groundwater, as cities explore ways to reduce its environmental impact.

As massive snow piles melt across Ontario cities after a heavy winter, researchers say the road salt mixed into them could pose serious risks to waterways, ecosystems and even drinking water.

Cities commonly pile snow cleared from streets and parking lots into large mounds. But those piles often contain more than just snow.

“What we’re getting is a really concentrated salt solution that can be released from it,” said University of Toronto professor emeritus and ecology expert Don Jackson. “And that’s ultimately draining into our streams and rivers and then to Lake Ontario.”

Researchers say salt runoff can have significant environmental effects.

According to research from the University of Waterloo, road salt can accumulate in soils and water bodies after winter, altering their natural chemical composition and harming freshwater ecosystems.

Scientists say the primary ingredient in road salt, sodium chloride, can persist in the environment indefinitely once introduced through road runoff.

Jackson said salt contamination can damage nearby vegetation and eventually seep into groundwater.

“You can also have that salt sinking into the ground, eventually getting into the groundwater,” he said.