Salty trend may cause long-term damage to Lake Simcoe watershed: LSRCA

Chloride concentration in the lake increasing by about .7 milligrams per litre annually since 1971

Yorkregion.com
April 27, 2017
By Chris Simon

For decades, salt has been the standard “go-to” for winter maintenance in the Lake Simcoe watershed.

But excessive winter salt usage, both by municipalities and private businesses, has caused the average chloride concentration in the lake to increase by about .7 milligrams per litre annually since 1971.

At this rate, the lake will exceed the Canadian government’s chronic (long-term) chloride guidelines by 2120.

While that seems like a long way off, reductions in usage take time and there’s little indication the increase is slowing, said Bill Thompson, the Lake Simcoe Region Conservation Authority’s manager of integrated watershed management.

“There’s really no change,” he said. “The challenge with salt is it’s pretty much invisible. You put it down and it disappears. The more people that are aware there’s an environmental impact, the more people will think twice before demanding that level of service from their local store or municipality. Their behaviour impacts the health of the watershed.”

About 100,000 tons of salt is applied to paved surfaces within the watershed each year. Much of that ends up in creeks and rivers before getting to the lake.

The LSRCA monitors chloride levels at 21 tributary locations and 17 lake stations.

Data show chronic guidelines are already exceeded in many creeks and rivers in Barrie, Newmarket and Aurora and that the issue is mostly caused by the larger urban municipalities around the lake.

“We look to not over-apply any de-icing materials on roadways and sidewalks,” Newmarket infrastructure services commissioner Peter Noehammer said. “That’s carefully measured.”

Periodic sampling over a five-year period has also recorded 17 cases of acute (short-term) guideline exceedances at Hotchkiss Creek in Barrie, and 44 at Holland Landing over one winter.