Road salt is used to keep roads clear in the winter but a researcher says municipalities should reduce the amount used due to the impact on local lakes. (Rhianna Schmunk/CBC)

An expert on road salt and its effect on waterways says municipalities need to start finding ways to reduce how much salt is used on roads in the winter.

Queen’s University professor Shelley Arnott will be speaking about the topic in Sudbury on Friday.

She’s been studying the negative impact of road salt on lake habitat. Arnott says studies have shown that water in the lakes in the Canadian Shield is softer, which means it doesn’t have a lot of calcium carbonate in it.

“Calcium carbonate can influence the toxicity of road salt and other contaminants like metals,” she said.

She says that means the effect of salt or chloride on the organisms in lakes in the Canadian Shield is greater.

“We find that they are much more susceptible at lower concentration of chloride,” she explained.

“So for soft water lakes we need to have another look at what level of protection we have for those lakes.”

Arnott says less salt should be used on the roads.

“[There is] pretty good evidence that increasing chloride has a negative effect on aquatic life and so somehow we have to come up with that balance,” she said.

“But I think there’s lots of things we can do.”

Arnott says mixing road salt with water can help reduce how much is used, adding using a brine like that is also more effective.

“I think we also need to explore the¬†alternatives and what the impact of those alternatives are,” she said.