DES MOINES, Wash. — A boil water notice is in effect for homes and businesses in parts of Des Moines and Normandy Park after E. coli was detected in the water supply for King County Water District No. 54.
Residents who reside within the notice area should bring their water to a rolling boil and allow it to cool before using it. Boiled or bottled water should be used for drinking, making ice, brushing teeth, washing dishes and preparing food until the notice is lifted, according to a release from the district.
The water district takes weekly samples for testing, and a recent sample showed E. coli was present in the water. Follow-up samples showed coliform in the water, of which E. coli is a subspecies of, but the samples did not show E. coli. Coliform bacteria is commonly found in the environment but is not expected to be in public water systems, according to the water district.
The areas impacted by the boil water notice are in the highlighted yellow box below:
Restaurants in the zone were closed in accordance with a directive from public health officials. The Washington State Department of Health will need to sign off before they can open again.
The district responded by chlorinating the water system beginning on Saturday, June 17.
While chlorination kills bacteria, it does have some other effects that could be unpleasant for people. Chlorine can clean off mineral buildup inside water pipes, like iron and manganese, resulting in cloudy or brown-looking water for some. The district will attempt to aggressively flush the system to clear the cloudy water, according to the release.
Water District #54 suspects the positive sample may have resulted from a water main break that dislodged some build-up.
The district will provide notice when the boil water order is lifted.