
(Image: Getty Images)
Residents across California’s Five Cities area have been issued a boil water advisory following the detection of coliform bacteria in the local water system, according to the San Luis Obispo County Public Works Department.
The advisory applies to Arroyo Grande, Grover Beach, Oceano, Pismo Beach, Avila Beach, and customers served by the San Miguelito Water Company (Zone 3). In total, nearly 46,000 people are impacted by the warning.
Officials detected coliform bacteria in multiple samples collected from the Lopez distribution system. While coliform bacteria itself is not necessarily harmful, it can indicate the presence of more dangerous pathogens such as E. coli. As a result, residents are being urged to boil all tap water for at least one minute before using it for drinking, cooking, or brushing teeth, told Newsweek.
“This is the first time a boil water notice has been triggered for the Lopez distribution system, and we are still working to identify the cause,” the County Public Works Department said in a public notice. Routine sampling that produced repeated positive results for coliform bacteria prompted the mandatory boil order, which complies with California State Water Resources Control Board regulations.
The situation is being monitored closely. Officials stated that the samples collected since the order was issued show a downward trend in contamination levels. “Representatives from the State Division of Drinking Water will be on site Friday, May 2, 2025, to lead the investigation,” the county said.
City leaders are urging residents to take the advisory seriously, especially those with vulnerable family members. “I was on the phone until 11 o’clock last night and all morning this morning trying to gather accurate information to be able to get it to you,” Arroyo Grande Mayor Caren Ray Russom said on Instagram. “For now please follow the boil water order no matter what filtration system you have at home.”
Pismo Beach City Manager Jorge Garcia also addressed residents via Facebook, confirming that while test results in Pismo remain within normal limits, the city will continue to follow county guidance.
The advisory will remain in effect until water quality is verified as safe by state and county health officials. In the meantime, both residents and pets should use either bottled water or properly boiled and cooled tap water.