Salt runoff ruining lakefront ‘jewel’

PICKERING — The salt spread on roads during harsh winter storms brings temporary relief to drivers racing down icy roads, but wreaks havoc on vulnerable ecosystems nearby.

In some cases, road salt is destroying them altogether.

An extensive five-year study published this week by researchers at the University of Toronto Scarborough found that Pickering’s Frenchman’s Bay, considered the “jewel” of the city’s waterfront, is a stew of harsh contaminants with levels far exceeding provincial water standards.

The pollution has reduced the number of fish, lowered the aquatic diversity and is destroying the provincially significant wetlands around the north end of the bay.

“Startling” levels of E. coli, lead, chloride and aluminum have been detected, said Nick Eyles, a professor of geology who led the study. The biggest culprit, he said, is the road salt sprinkled every winter on Hwy. 401, just north of the bay.

“There is a year-round impact of putting salt on for just a few weeks in the winter,” said Mr. Eyles, who studied the lagoon from 2002 to 2007. “Just imagine the impact it’s having on the fish in the inner northern parts of the bay.”

His team determined that 3,600 tonnes of dissolved road salt ends up in the small lagoon in the winter, mostly from direct runoff in four creeks during warmer thaws, and from groundwater that has become saturated with salt over time.

The highway accounts for more than a quarter of all road salt that ends up in the bay, but covers just over one per cent of the area, he said. “There is a lot of salt put on these roads, and there is almost nothing to prevent it going directly into the creeks,” he said, adding that metals, oils from the highways and animal waste carried along the creeks also contribute to the chemical mix.

Similar conditions have been seen in watersheds along the Great Lakes, Mr. Eyles said, but this is the first study to show that the damage from salt runoff lasts year round.

“This is really about a much larger issue. Our development is having a significant impact on the water quality of our waterways.”

The greatest concern is that the contaminated water is entering the Great Lakes, where much of our drinking water comes from.

Pickering City officials say they have been aware of the impending ecological crisis at Frenchman’s Bay for years. They hired Mr. Eyles and his team to assess the impact of urban development on the bay in 2003 and saw similar results.

“There is concern that the bay is regressing,” said Richard Holborn, division head of engineering services with the City. Since then, the City has been working to create a Frenchman’s Bay storm water management master plan to improve water quality, flooding and erosion issues. In the long term, there may be plans to restore the bay’s northern wetland back to health, he said.

The master plan is expected to go to council for approval in April.

The study is the latest in extensive research that points to the hazards of salt on the environment. In 2001, Environment Canada recommended road salt be considered a toxic substance because of its negative impact on ecosystems. That never happened. Instead, the federal government adopted a voluntary “code of practice,” which most municipalities have signed onto. They are expected to release a five-year assessment of the code’s effectiveness for the environment this year.

Almost all municipalities agree that road salt is damaging, yet it continues to be used because it is the cheapest option. Over the past five years, many municipalities have made an effort to reduce salt use and find cleaner options like beet solution and sand, said Mark Rabbior, a spokesman with the provincial environment ministry.

But salt is used as a default option, in part because it is effective regardless of temperature fluctuations and severity of weather.

The problem is, salt runoff into streams, ponds and rivers is no longer just a winter problem. Although all salt is dispersed in the winter, the water quality is worse in the summer when Frenchman’s Bay is busiest, said Mr. Eyles.

“In the summer, you get algae blooms, and you get this milky brown water as a result. That cuts off sunlight that reaches the bottom of the lagoon, and so vegetation can’t grow, and fish don’t come into the area,” he said. “If you look at the lake from above, you can see a plume of dirty water coming out of the bay into Lake Ontario.”

The only thing “saving it now” is that it is diluted by water from Lake Ontario. But at the same time, Mr. Eyles said, the polluted bay is adding to the “chemical load” going into the body of water that makes up our main drinking source.