The county Department of Water Supply detected E. coli bacteria Thursday in the Ualapue shaft on Molokai, according to an announcement.

The water in the Ualapue system has since been disinfected and is safe to drink.

The bacteria was found in a water sample taken Wednesday. Testing took 18 hours to complete.

No E. coli was found during subsequent sampling Thursday, and the department plans to provide another update today.

Department officials said they were completing a comprehensive assessment of the Molokai water system and the department’s monitoring and operational practices to identify and correct any sources of contamination.

The presence of E. coli indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes can cause diarrhea, cramps, nausea, headaches or other symptoms.

The bacteria may pose a special health risk for infants, young children, elderly and people with severely compromised immune systems. E. coli also can exist in tropical, subtropical and temperate soils and may persist in soil over multiple years.

Residents should warn anyone who might drink the water about the contamination risk.For more information or to report water-related problems, call 270-7633. For general guidelines to lessen risks, call the Environmental Protection Agency’s safe drinking water hotline at (800) 426-4791.