The Portland Water Bureau issued a ‘Boil Water Notice’ on Saturday, July 21, 2012. Customers of the Portland Water Bureau west of the Willamette River are affected. Customers of Burlington Water District, Valley View Water District, Palatine Hills Water District, City of Tigard, Lake Grove Water District, and West Slope Water District are also affected.
Customers of Tualatin Valley Water District, Southwood Water District, and Raleigh Hills Water District are not affected.
A routine sample was collected July 19, 2012, at the outlet of Reservoir 3 in Washington Park. Results received early Friday July 20 showed possible bacterial contamination. The reservoir was shut-off and follow-up samples were collected immediately. Results of these samples were available this morning. One of the follow-up samples tested positive for bacteria, the presence of which indicates that the water may be contaminated with human or animal wastes.
All tap water within the defined area used for drinking, food preparation, and ice should be boiled at a full rolling boil for at least one minute. Ice or any beverages prepared with tap water after Thursday, July 19 should be discarded.
The bacteria found were total coliforms and E.coli. These bacteria are found in the human digestive system and very few strains cause serious disease and illness. Although the specific strain of E. coli is not known, generally the worst strains that are associated with serious illness are rarely found in water supplies.
Portland Water Bureau Administrator David Shaff said, “Although these bacteria are generally not harmful, their presence in drinking water could indicate harmful organisms might have entered the distribution system, so we are taking every precaution to protect our customers.”
The US Environmental Protection Agency has set an enforceable drinking water standard for total coliforms to reduce the risk of adverse health effects. Under this standard, all drinking water must be free of these bacteria.
The Boil Water Notice is in effect immediately and customers will be notified when they no longer have to boil their water. Portland Water Bureau customers will be able to log on to www.portlandonline.com/water and type their address in the box provided to determine if their residence or business is in the Boil Water Notice area.
The Boil Water Notice, fact sheets and contact information are provided on this same website. For more information, contact the Portland Water Bureau at 503-823-7770.