Positive E. coli test in Sudbury drinking water found to be incorrect
Glitch at an underground water sampling station blamed for false-positive
cbc.ca, March 1, 2018
A seeming case of bacterial contamination in Greater Sudbury's water supply in 2017 was a false alarm.
Mike Jensen, the Acting Director of Wastewater Treatment, said routine testing in March and November of last year turned up E. coli and coliform bacteria in Garson's water supply.
"So we keep a pretty close eye on that any level of these types of bacteria by regulation and our practice is to immediately take action so it's not something we take lightly," he said. "The response time that we had was very effective and at no time was public health at risk."
Jensen said workers responded quickly, testing water in pipes on either side of the water sampling station and flushing the system with chlorine as a precaution.
Eventually, Jensen said they narrowed the cause of that seeming bacterial contamination down to a malfunction with an underground water sampling station — or the testing process itself.
The test was a false positive.
"Even something like touching the edge of the faucet where they take a sample from, or bottle, that procedural error, or a mistake in the lab. It could be any number of places where these sorts of bacteria might be entered into the test."
The standards for drinking water safety are very strict since the contamination of Walkerton's water supply with E. coli in 2000 caused the deaths of seven people and sickened 2,300.
The results are found in the 2017 Annual Water Quality Report for Greater Sudbury which is now online.