OLYMPIA — The state Department of Health has issued a boil-water advisory for the Crescent Water Association system.

The advisory was issued today after E. coli was detected in water samples from the system, which serves about 900 homes and businesses in Joyce.

The potentially harmful bacteria were detected in a routine monitoring sample, and follow-up testing confirmed the presence of E. coli in the water, the state said.

E. coli can cause such short-term health effects as diarrhea, cramps, nausea, headaches, or other symptoms, and may pose a special health risk for infants, young children, some of the elderly, and people with weak immune systems.

People at increased risk should seek advice about drinking water from their health care provider.

Until follow-up test results are satisfactory, the Department of Health recommends that residents boil tap water used for drinking, brushing teeth, dishwashing, preparing food, and making ice.

Water should be boiled for one minute and allowed to cool before use.

State health officials are working with the water system to help determine the source of contamination and resolve the problem as quickly as possible.

The water system staff has increased chlorine levels in an effort to eliminate the bacteria.

“We are taking multiple samples from all over the system to try to isolate the problem,” said Connie Beauvais, Crescent’s water system operator.

Customers will be notified when the advisory is lifted, she said.

Crescent Water Association customers who have questions may call 360-928-3128.