The city of Thompson, Man., has been placed under a boil water advisory.
Test results taken on October 31 revealed total coliform bacteria in the treated and distributed water supply.
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The Manitoba government is asking residents to bring water used for consumption to a rolling boil for at least one minute.
Water does not need to be boiled for laundry and washing dishes.
The boil water advisory will remain in effect until the water no longer represents a risk to public health.
The city of Dauphin has also been under a boil water advisory since Nov. 1.
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