GRAND RONDE -- Customers of the Grand Ronde Community Water Association have been warned to boil any water used for drinking, cooking, making ice or brushing teeth until further notice.
Results from regular testing revealed Monday that water in the system tested positive for E. coli, a bacteria. The utility uses water from four springs and it is routinely tested for contaminants.
As of Friday afternoon, water association officials weren't certain of the source of the bacteria.
"We don't know what is causing the problem," said Karl Ekstrom, the water association manager. "We are thinking it's the distribution system because all samples from the springs have come back good."
The water association has about 950 service hookups and employees spent Tuesday calling or leaving door hangers telling people to boil their water.
Ekstrom said a disinfection procedure, in which the system is flushed with chlorinated water, will begin Monday.
He said he will likely have a better idea when customers can stop boiling water after the system flush is complete.
"We are diligently working on the problem," Ekstrom said. "We want to get people back into normal service as fast as possible."