Water, water everywhere… and tested often

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This article was published 30/01/2015 (3995 days ago), so information in it may no longer be current.

Fifty-seven times.

That’s how many times Winnipeg’s drinking water is tested each week for coliform bacteria, said Kim Philip, director of the province’s Office of Drinking Water.

The city takes 39 regulatory compliance samples throughout its water-distribution system, plus an additional 18 samples it does on its own accord, she said.

‘It’s absolutely done by the book. This is a big city. They take the job seriously’

— Kim Philip, director of the province’s Office of Drinking Water

“It’s absolutely done by the book,” she said. “This is a big city. They take the job seriously.”

Philip said each test is done at the ALS Environmental laboratory in Winnipeg, a private lab contracted by the province to test drinking water for public distribution systems such as Winnipeg’s.

A spokeswoman from ALS declined comment on the city’s precautionary boil-water advisory and the investigation into what may have happened in the testing process that led to the advisory.

Philip said under the contract, the lab sends out water-sample bottles to the client with a customized, preprinted chain-of-custody form specific to that water system. A designated person takes the water samples and sends them back to the lab.

She said the lab has the responsibility to call the water system’s owner if a positive test result comes back and then notify the Office of Drinking Water.

“We try to find out what’s going on,” Philip said. “We make sure that these are valid results.”

Part of that conversation includes determining the levels of chlorine residuals in the water system, which are recorded when the water sample is taken.

Based on that, she said, her office contacts the province’s medical officer of health if it’s believed an advisory has to be issued. Under the province’s Drinking Water Safety Act, the designated medical officer of health is responsible for issuing any advisory. Because it’s a city-water issue, Dr. Lisa Richards of the Winnipeg Regional Health Authority is responsible.

“Only the medical officer of health can rescind an advisory,” Philip added. “Nobody else.”

To do that, she said, national guidelines stipulate there needs to be two consecutive clean re-sample results at least 24 hours apart.

The two-day boil-water advisory was lifted Thursday afternoon after the two consecutive tests showed the city’s drinking water is safe.

What continues is the investigation into what caused the advisory to be initiated in the first place.

City water engineers believe it was caused by “false positive” results based on the apparent coexistence of bacteria and chlorine in the samples, as well as the fact no bacteria were found in samples collected upstream and downstream of the six original problematic sites. It’s not yet known whether sampling error, a laboratory process or some other error led to the suspected “false positive” for coliform bacteria.

“There is a lot of work going on,” Philip said. “That investigation is ongoing to try to find out exactly what happened. We don’t want to guess at this point until there is actual information to pass on.”

She added laboratory testing for coliform bacteria is a well-established process, as is the sampling done by the City of Winnipeg.

Private drinking-water systems, such as homes that have their own wells, are tested less frequently by the homeowner, with samples handled by Horizon Laboratory in Winnipeg.

The province recommends at bare minimum, well water be tested once a year.

“The larger the system is, the more samples they have to take,” she said.

bruce.owen@freepress.mb.ca