Wawa Planning Pilot Project to Reduce THMs

Efforts to address a years-long water advisory in Wawa will ramp up this summer.

The Municipality's planning a pilot project using a poly-aluminum chloride coagulant to reduce "THMs" (trihalomethanes), which are a result of organic material - dissolved carbon - reacting with chlorine used to treat the water.

While he's faced questions from Council - particularly Councillor Bill Chiasson - about the safety of using a chemical compound to treat the problem, Infrastructure Services Director Cory Stainthorpe assures testing has shown low "alum residuals" after filtration - and he emphasizes aluminum is a natural mineral in many products, particularly canned products.

Other methods tried included lower amounts of chlorine and lower amounts of water in the water tower, and Stainthorpe says testing does put the THM amount within Ontario Drinking Water Quality Standards, but not as low as would be liked, as a brief spike could undo that.

A water quality advisory issued by Algoma Public Health in November 2014 remains in effect because of that, though the initial advisory emphasized there's only a risk from chronic, long-term exposure - drinking "a gallon a day every day for 35 years" - which would only mean a "slight increase" to risk of bladder cancer.

Stainthorpe expects the pilot to begin in July, running for a few months - the period when THMs are highest.