It would cost more than $100 million to install granular activated carbon filters in Toronto water treatment plants, said Hiroshi Taniguchi, the city's director of water supply.
"We're talking about a major process addition to all of our plants. It would be huge activated carbon filters that filter the water after our normal filtration to remove taste and odour compounds," he said.
Chlorination and conventional water treatment won't remove the "earthy" taste and odour during periods of algae buildup, he added.
However, the frequency and duration of past episodes of smelly water have not been enough "to make recommendations for that sort of expenditure."
The problem surfaced in 1994 and again - though less seriously - in 1996, with the unpleasant characteristics disappearing within days.
"If the frequency and duration of episodes increases, it's a different story, there might be a stronger justification to invest those kinds of dollars," Taniguchi said.
The algae and microbes creating the stench this time around (by producing a compound known as geosmin) struck in Durham Region first and have been moving west.
Durham spokesperson Ron Motum said complaints started Saturday (August 11) and have continued. Taniguchi said Toronto's problem first surfaced at a Scarborough filtration plant near the Pickering border, then at a plant at the foot of Victoria Park. On August 12, the city's most westerly plant, R.L Clark, also began to detect the foul taste and odour.
Mitch Zamjoc, Peel Region's public works commissioner, said residents there have also started to complain. "We have the same issue, but on a much smaller scale. We've had some complaints, but not many."
Zamjoc said filtration plants in Peel are adding more chlorine to the water, hoping it will partially mask the taste and smell.
Odour and taste problems routinely occur at this time of year but not to this extent, he said.
Meanwhile, water problems of a different sort have forced public health officials to post warning signs at 10 Toronto beaches finding unsafe levels of E. coli bacteria. People are advised against taking dips at Marie Curtis Park East and West, Colonel Samuel Smith Park East and West, Amos Waites Park, Windermere/Ellis Ave., Sunnyside, Centre Island, Hanlon's Point, Bluffers Park, Humber Bay Park East and Rouge Beach.
E. coli is found in the waste of animals and humans. Swimming in contaminated water can lead to ear, nose and throat infections, an upset stomach, skin rash and diarrhea. Officials warn that children and the elderly, as well as those with suppressed immune systems, are most susceptible .
Source: Toronto Star
