TORONTO, March 2, 2010 The levels of contamination to water and sediment in Frenchman's Bay in Pickering, Ontario greatly exceed provincial water quality standards, in some cases by as much as 250 per cent, according to a new study by researchers at the University of Toronto Scarborough. This is largely due to large amounts of road salt applied in winter, especially to Highway 401, the study finds.
Roads, parking lots and railways are the primary source of contaminated water and sediment and a decline in aquatic life in the watershed and lagoon, according to a recent article in Sedimentary Geology written by geology professor Nick Eyles and recent PhD graduate Mandy Meriano.
The densely populated area along Highway 401 and its accompanying traffic volume have profoundly affected the geology and characteristics of water in the bay and nearby city, according to the article, "Road-impacted sediment and water in a Lake Ontario watershed and lagoon, City of Pickering, Ontario, Canada: An example of urban basin analysis." The growing city of 100,000 people is sprawled across a densely urbanized watershed that has been "hardened" by roads, rail lines, buildings and parking lots, the authors write.
"Our findings are pretty dramatic, and the effects are felt year round," says Eyles. "This is a really bad news story about the relentless chemical assault on a watershed, with bleak implications that go far beyond the lagoon itself. We now know that 3,600 tonnes of road salt end up in that small lagoon every winter from direct runoff in creeks and effectively poison it for the rest of the year. The future of Frenchman's Bay is not bright, but this also affects the Great Lakes."
The researchers conducted an extensive study of streams and groundwater entering Frenchman's Bay over a five-year period using sophisticated field testing and groundwater modeling methods. Some 7,600 tonnes of de-icing salt are applied to nearby roads ea
|Contact: Eleni Kanavas|
University of Toronto