"We are still assessing what exactly happened but it appears a valve may have stuck allowing the potassium permanganate to get into our sump reservoir and thereby into the Town’s water distribution system," Onoway Mayor Dale Krasnow said on the town's official website.
Potassium permanganate is widely used to remove bad taste and odours from drinking water. Too much of the chemical, however, can turn the water pink or purple.
According to Krasnow, "there was never a public health risk" and the town flushed its water distribution system to deal with the problem.