The boil water notice for Portland water customers has been lifted.
Tap water is safe to drink for all customers of the Portland Water Bureau, Burlington, city of Gresham, Lake Grove, Lorna Water, Palatine Hill, Rockwood, Tigard Water Service Area (including Durham, King City and Bull Mountain), Valley View and West Slope Water Districts.
Follow-up testing of drinking water has shown the absence of bacterial contamination. The Portland Water Bureau recommends flushing all taps for two minutes or until the water runs cold before consuming for the first time. This will flush any potentially contaminated water from the plumbing.
The Portland Water Bureau issued a "Boil Water Notice" on Friday, May 23, in response to bacterial contamination detected at three locations in its system.
Tests conducted throughout the affected area since the notice was issued were clear of contamination.
As a precaution, the Portland Water Bureau will be draining and cleaning Reservoirs one and five. An investigation into determining the source of contamination is ongoing. The reservoirs will be put back into service once it is determined to be safe to do so.
For more information visit:
or call the Water Bureau Customer Service line at (503) 823-7770.
The original alert was ordered by the state of Oregon Health Authority's Drinking Water Program after water samples taken at the three locations test positive over three-day period for total coliform and E. coli bacteria.
The alert came at the start of the Portland Rose Festival and Memorial Day Weekend, a time when many people are traveling into the region.
"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.
According to the water bureau, in three separate incidents from May 20 to May 23, repeat water samples confirmed the presence of total coliform and E. coli in routine drinking water samples. The water samples that tested positive for bacteria were collected at the outlets of Mt. Tabor Reservoirs 1 and 5, and at the S.E .2nd Avenue and Salmon Street water sampling station. Both reservoirs have been taken offline.
The bureau is working with the Multnomah County Health Department to provide health-related information to the public.
"The chance of any health problems related to this water test result is low. If any problems occur, we would expect diarrhea," said Dr. Paul Lewis, Interim Tri-County Health Officer. "We monitor cases of bacterial diarrhea and will be aware of any increase following this event."
The bureau collects approximately 240 routine bacterial samples per month throughout the system. The test to determine the presence of bacteria takes about 18 hours. It is not unusual for one of these samples to test positive for bacteria. Samples to confirm possible contamination are collected immediately after an initial detection of the presence of bacteria in drinking water. Once the detection has been confirmed, public health officials recommend that the public boil all tap water before consuming.
Contamination can occur when there is a loss of water pressure, a pipe breaks, or conditions that expose drinking water to outside elements. The Portland Water Bureau is performing a full investigation to identify the cause of the contamination. However, it is not always possible to make an exact determination.