PORTLAND, Ore. - The Portland Water Bureau lifted the most extensive boil water notice in its history Saturday morning after dozens of new water samples tested negative for E. coli bacteria.
The bureau said on its website that tap water is safe to drink, however it recommends flushing all taps for 2 minutes or until the water runs cold before drinking tap water for the first time. Doing so will flush any water that might be contaminated.
"The risk is really, really, really small," said David Shaff, the water bureau's administrator. "It's almost immeasurable."
State health officials detected E. coli bacteria in water samples at three locations over a three-day period earlier this week, which Shaff called a "highly unusual event."
Shaff says the 24-hour boil notice was issued in cooperation with the Oregon Health Authority out of an abundance of caution. Scientists detect E. coli, which indicates animal waste, in Portland's water supply about once every two months.
In those cases, however, they only find the bacteria in one place and don't feel it's necessary to warn the public while still reporting the results to other authorities, according to Shaff.
Officials said 670,000 people were affected by the boil water notice; the largest in the city's history.
It's unclear what caused the contamination. An investigation into determining the source is ongoing, the bureau said.
"It could have been a duck. It could have been a raccoon," Shaff said. "Somebody could have walked by the reservoir and tossed their dog poop bag in there."
Could a single duck trigger an E. coli sample to test positive? Shaff said yes.
"It depends where the sample is at the time the poop that came out of that duck is going through the system," said Shaff. "It could just be a bad coincidence."
As a precaution, the Portland Water Bureau says it will be draining and cleaning Reservoirs 1 and 5. The reservoirs will be put back into service once they are determined to be safe.
"Public confidence," said Shaff -- not public safety.
After all, animal waste is gross, even if it's not dangerous in tiny doses.
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