Any ice or beverages prepared with unboiled tap water on or after May 20 should be thrown out.
The water samples that tested positive for bacteria were collected at Mt. Tabor Reservoirs 1 and 5, as well as the Southeast 2nd Avenue and Salmon Street water sampling station.
Those reservoirs have been taken offline.
Along with Portland Water Bureau customers, other local water providers also fall under the boil water notice. They are: Burlington Water District, City of Gresham (North of I-84), Lake Grove Water District, Lorna Portland Water, Palatine Hill Water District, Rockwood Water District, Tigard Water Service Area (including Durham, King City and Bull Mountain), Valley View Water District and West Slope Water District.
"While we believe at this time that the potential health risk is relatively small, we take any contamination seriously and are taking every precaution to protect public health," said Portland Water Bureau Administrator David Shaff.
Customers will be notified when they no longer have to boil their water after investigators determine the water system is clean of contamination through surveillance sampling.
Contamination can occur when there is a loss of water pressure, a pipe breaks or conditions expose drinking water to outside elements. The Portland Water Bureau is performing a full investigation to identify the cause of the contamination, but workers said it is not always possible to make an exact determination.
Friday, May 23 2014 9:32 PM EDT2014-05-24 01:32:45 GMT
What do I do? All water used for drinking, teeth brushing, food preparation, and ice should be boiled at a full rolling boil for at least 1 minute as a safety precaution. Ice or any beverages preparedMore >>
All water used for drinking, teeth brushing, food preparation, and ice should be boiled at a full rolling boil for at least 1 minute as a safety precaution.More >>