By Anneleen Naudts
The days of phosphorus in Holland Marsh canals are numbered.
Phosphorus, a chemical element and source of food for algae, will soon be extracted from the canals using a product called Phoslock.
Township council recently approved the proposal by Lake Simcoe Region Conservation Authority (LSRCA) to use Phoslock to treat the inner canal in spring and fall, prior to major periods of pumping.
Phoslock is not a chemical, said Mike Walters, LSRCA’s director of watershed management.
Dubbed a quick-fix solution, applying Phoslock is a straightforward process which will entail adding 45 metric tons of the precipitant to the Holland inner canal. When added to water, phosphorus binds to Phoslock’s modified lanthanum enriched clay while sinking to the bottom. As it settles, forming a thin layer of one to three millimeters, Phoslock continues to absorb phosphorus, Walters explained.
Phoslock has been successfully used as a phosphorus removal agent in the United States, Germany, Australia, New Zealand and China, said Walters, who also gave assurances it’s safe. It has been subjected to extensive ecotoxicity testing and most recently was tested on algae, juvenile fish and water fleas.
Its track record includes establishing healthy fisheries, and creating drinking water impoundments in Western Australia, explained Walters.
An immediate benefit is expected, he added. The application will result in phosphorus reductions of 87 to 95 per cent. He said continuous sampling and a mid-year report are planned to determine the effectiveness of the pilot project.
The best news is it won’t cost King Township a penny. The pilot project, which comes with a $126,560 price tag, will be funded by Ontario’s Ministry of the Environment. This constitutes part of the McGuinty government’s plan to develop long-term measures to protect the health of Lake Simcoe, Environment Minister John Gerretsen announced.
Councillors last week rooted for the project. Councillor Jeff Laidlaw inquired whether Phoslock would cause any displacement of water, and Walters replied the displacement is not expected to exceed five centimeters, providing regular dredging of the system occurs.
Councillor Jack Rupke, who has discussed this system with King’s farming community, considered Phoslock to be an economical option. He added that so long as LSRCA makes a presentation to farmers, he expected they too would be in favour of it.
Councillor Linda Pabst said she would gladly support this “good news story,” as did Councillor Jane Underhill, who said there didn’t seem to be any drawbacks.
Mayor Margaret Black called using Phoslock a way of “solving a problem we thought couldn’t be solved years ago.”