Residents in a small section of Los Angeles’ Koreatown have been told to boil their tap water or rely on bottled water after routine testing found potentially dangerous bacteria in the local water supply.
The boil water notice was issued Tuesday for an area spanning roughly two blocks after preliminary results from one testing site came back positive for Escherichia coli, commonly known as E. coli.
The warning prompted an immediate response from local officials, including bottled water distribution and crews visiting homes and businesses to notify people directly.
The Los Angeles Department of Water & Power (LADWP), working with the State Water Resources Control Board’s Division of Drinking Water, advised residents not to use tap water unless it has been boiled first.
“ONLY USE BOILED TAP WATER OR BOTTLED WATER FOR DRINKING AND COOKING PURPOSES until further notice due to the positive Escherichia coli (E. coli) bacteria results received on June 30, 2026,” the Los Angeles Department of Water & Power (LADWP) and the State Water Resources Control Board Division of Drinking Water said in the notice.
According to the alert, the affected zone includes “the southern side of West 5th Street, the western side of Mariposa Avenue, the northern side of 6th Street, the eastern side of Ardmore Avenue, and the two square block area within.”
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Officials said the issue appears to be limited to that specific area and stressed that it is not connected to the recent fire in Boyle Heights.
By Wednesday afternoon, trucks carrying pallets of bottled water were stationed around the neighborhood, where residents lined up to collect free supplies.
The office of LA Councilmember Heather Hutt, whose Council District 10 includes Koreatown, said it is coordinating with LADWP while crews continue testing the water system.
“LADWP has stated this is an isolated exposure, narrowed down to a singular testing location amongst many in the area,” Hutt’s office said. “Our staff are currently walking door to door in the affected area notifying residents and business owners about the boiling water notice.”
Hutt’s office added that the council district is also helping distribute free bottled water and ice while officials work to determine the source of the contamination. It was not immediately clear how long the boil water notice would remain in effect.
Most strains of E. coli are harmless and naturally live in the human intestine, helping digest food and protect against harmful germs. But some varieties can trigger serious gastrointestinal illness.
“Some kinds can cause bloody diarrhea, watery diarrhea, or both. Some of these E. coli can cause other symptoms, including stomach cramps, vomiting, and fever,” according to the CDC.
