Recent fact-finding visits to the municipalities of Casselman and Alexandria should improve the management of Renfrew’s drinking water in 2013.
The summer drought in Renfrew County altered the chemistry of the water, leaving a buildup of manganese. Manganese isn’t a health concern whatsoever, says Renfrew development and works director Mike Asselin.
But he says it creates darker water that appears to be dirtier. As a result, the town flushed about 62 kilometres of water mains this fall to remove the buildup of manganese.
“Both of those treatment plants have facilities for treatment of manganese,” said Asselin of the Nov. 16 visit to Alexandria and Casselman by himself, two J.L. Richards engineering consultants and the town’s Ontario Clean Water Agency chief operator.
“During the drought of 2012 we did see the manganese levels in the river spike, and our treatment system at the water treatment plant has no way to treat for manganese,” said Asselin.
“So it ends up oxidizing in the system, and some homes were getting brown water out of the taps. Although it was safe, it was very unpleasant-looking, and it’s something we want to absolutely avoid.”
The only way to avoid this situation is to establish a manganese-treatment system, says Asselin.
Central to that system is potassium permanganate. This chemical oxidizes the manganese into solids. The solids would then be removed by filters at the water-treatment plant, before entering the drinking-water system.
Both Casselman and Alexandria have a year-round issue with manganese.
“We saw the chemical feed system they use, and storage, and talked to them about storage requirements and the sensitivities of over-dosing or under-dosing that chemical,” said Asselin.
Over-dosing can provide a pink colouring of the water.
With or without a drought, the town sees elevated manganese levels each spring, so the hope is to have a treatment system in place for the spring of 2013. The anticipated cost is $40,000 to $50,000, says Asselin.
“We’d still have to do regular directional flushing, as part of our maintenance of our distribution system, but nothing to the extent that we saw this year.”