Two lake lungs will protect Richmond Hill's aquatic asset ­ Lake Wilcox

By Tom Davey

Over the years, I have spent many hours windsurfing and swimming in Lake Wilcox, 40k north of Toronto. Gradually it became obvious that the water quality was becoming seriously impaired. The deterioration should decrease with the installation of two "lake lungs" in August. The Wilcox lungs follow two earlier pilot projects at Heart Lake in Brampton and Chesley Lake in Owen Sound, Ontario.

lakelung

PVC hypolimnetic oxygenation devices under construction.

"The lake lungs pump oxygen into the water," says John Nemeth, Richmond Hill's manager of environmental services. "In summer, oxygen levels become depleted. The top four or five metres will have oxygen, but the lake is 18 metres deep."

All the fish and the zooplankton that they eat, move into the top portion of the lake, where the oxygen is. By the end of June, fish start to lose a lot of their food sources. They end up eating each other, doing what they have to do to stay alive.

By pumping oxygen throughout the lake, the lungs allow the fish and zoo-plankton to live in deeper water. Food will be more abundant, which means more fish will be able to live in the lake.

The Town of Richmond Hill looked at many different options and the planning department was also involved. The use of lake lungs was the best option.

The equipment costs $405,000; the town is paying just under half the cost, with the remainder shared by the Great Lakes 2000 Clean Up Fund, Ministry of Environment and Energy and Richmond Hill Hydro Electric Commission. The project will cost $10,000 annually.

Technically known as hypolimnetic oxygenation devices, the U-shaped PVC pipes are 600 millimetres in diameter. The open ends of the U are pointed toward the bottom of the lake and the closed end is at the surface, supported by flotation devices. One penetrates 14 metres deep and the other goes 18 metres down. The 95 percent pure oxygen is pumped out to the lungs from an O2 generator on the shore.

The lake lungs, the largest project of its kind in North America, will be welcomed by swimmers, canoists and windsurfers.