Maui Water Department officials yesterday advised residents in portions of Makawao to boil their water after E. coli bacteria turned up in the water supply Wednesday.

The affected area has fewer than 50 households, the county said.

The affected area spans from the fire station on Makawao Avenue, Nane Lane, to the intersection of Makawao Avenue and the Old Haleakala Highway. Ki'i Place, Pukalani Square, and Pukalani Superette are on a different waterline and are not affected. Pukalani Baptist Church also is not affected.

E. coli bacteria can make people sick. Contamination is a particular concern for people with weakened immune systems.