All of Portland, Ore., was told Friday to boil its tap water after the city found E. coli in water samples.
An alert sent to people who live in the city and nearby warned that they "should boil all tap water used for drinking, food preparation, tooth brushing and ice for at least one minute. Ice or any beverages prepared with un-boiled tap water on or after May 20 should be discarded."
In all, 670,000 customers are under the order, health officials said at a news conference. "Animal waste" — fecal matter — in the water was the likely source of the E. coli, they said.
There were no immediate reports that anyone had been sickened by drinking the water.
Samples taken three times between May 20 and May 23 "confirmed the presence of total coliform and E. coli in routine drinking water samples," the Portland Water Bureau said.
Tigard and King City, Oregon, as well as parts of Gresham and other districts, also received the alert, NBC affiliate KGW reported. A full list of areas affected is available at KGW com.
Most types of E. coli, a bacterium, are harmless or cause brief diarrhea, according to the Mayo Clinic. But some strains can cause abdominal cramps, bloody diarrhea and vomiting.
Based on test results, officials said they believed the risk to the public was low.
But that didn't prevent a frenzy at local businesses. Rebekah Yli-Luoma, co-owner of Heart coffee shop in Portland, said, "Right now in the community, it seems like everybody's panicking."
Business had slowed down noticeably since the alert was sent out, she said, but the coffee shop continued to serve what it could.
"We're not using ice, we're not using anything that's not hot," Yli-Luoma said. "But we're also informing the customers about what the situation is. And if they want to drink at their own risk, they can."
This is the second water problem in two months for Portland. In April, the Portland Water Bureau diverted nearly 36 million gallons of water from a reservoir after officials feared it was tainted by a teenager's urine.