Winnipeg, MB - Results received today are negative for bacteria in all the water samples retested. However, the provincial Medical Officer of Health advises that the precautionary boil water advisory will remain in place pending the test results of another resample.
The Medical Officer of Health issued a precautionary boil water advisory for Winnipeg’s water system late yesterday due to positive results for bacteria in some water samples taken as part of routine compliance testing under the Operating Licence issued by the Provincial Office of Drinking Water. Positive test results do happen from time to time, but usually retest negative.
City staff take all the water samples, and follow a 12 step sampling protocol. All bacteria tests are performed by a contracted lab. A number of factors can cause a water sample to have a false positive test result for bacteria, including:
- contaminated water tap at the sampling location,
- accidental contamination of the sample container,
- accidental contamination of the water during sampling, and
- accidental contamination at the laboratory during analysis.
The chlorine levels at all sampling locations, including the locations that tested positive, measured better than the level required in the Operating Licence and would have effectively killed any bacteria in the water.
The Manitoba Office of Drinking Water, Manitoba Health and the Winnipeg Regional Health Authority have advised us that they will review the next set of test results tomorrow and the Medical Officer of Health will make a determination on the status of the precautionary boil water advisory issued to the City last evening.
More information is available at City of Winnipeg - Precautionary Measures during a Boil Water Advisory