E. coli bacteria reside in human and animal waste and certain strains can cause diarrhea, cramps, nausea and headaches.
The risk of illness is greater for the elderly and those with compromised immune systems.
Regal Mobile Estates residents who use the water should boil it first before drinking it, preparing meals, washing dishes or brushing their teeth, health officials said.
Regal Community LLC bought the property in December.
That company is owned by Hurst & Son LLC, which manages 18 other similar communities in Washington and Idaho.
The company is providing free cases of bottled water for the residents.
The cases of bottled water are stacked in a shared laundry room, and resident Ron Mosier said he and others have helped distribute it to those with mobility issues.
“It’s a lot to expect senior citizens to carry 40-pound cases of water to their homes,” he said.
Mosier said he and his neighbors are making the best of the situation, but he worries about the strain it is placing on the tight-knit community, especially on those who have trouble getting around or who have memory problems and may forget the water is contaminated and drink it.
“(The owners) have a problem and now they have to proceed with better treatment or a better source,” he said.