A stewardship group in Sudbury, Ont., has installed eight catch basin filters on local waterways that have collected 31 kilograms of garbage so far.

With 16,000 catch basins across the city, that would translate to a cost of $8 million. Replacing the 275 filters in the test program would cost $137,500.

The city will begin installing 97 catch basin filters in storm drains today to reduce the amount of heavy metals, petroleum products and bacteria entering ocean waters, officials said.