Residents of Portland, Oregon, have been warned to avoid drinking tap water and to consume it only after boiling it, due to concerns over E. coli contamination. Health officials issued a warning on May 23, following tests that revealed the presence of bacteria in water supplied to consumers.
Approximately 650,000 people were affected by the warning. According to a statement released by the Portland Water Bureau, total coliform and E. coli were detected in three separate tests on drinking water samples, carried out between May 20 and May 23. Water tested in the samples was taken from two of Portland's Mt. Tabor reservoirs.
Residents have been advised to boil tap water for at least one minute. Ice and any beverages that were prepared with tap water around the specified period should be disposed of, the bureau added.
Portland Water Bureau Administrator David Shaff stated that the risk to public health is relatively low but the possibility of having the contamination spread is being taken seriously and all necessary steps to protect the public are being implemented. Shaff added that further tests would reveal whether the boil notice should be lifted but pointed out that such events usually affect the water supply over short periods of time.
Officials are investigating the cause of the contamination.
Last month, in an unrelated incident, Portland officials had to empty one of the Mt. Tabor reservoirs after a teenager was spotted urinating in the water, media reports noted.