A boil water order that was issued because of bacterial contamination has been lifted this afternoon for Arroyo Grande, Grover Beach, Oceano and the San Miguelito Mutual Water Company.
Residents can now use tap water normally.
San Luis Obispo County Public Works told KCBX these areas have switched to an uncontaminated water source.
However, the boil water order is still in effect for Pismo Beach and Avila, which are still connected to the contaminated Lopez Water Distribution system.
Nola Engelskirger with Public Works said the California State Water Resources Control Board started looking into the cause on-site today.
“They will also be inspecting the integrity of our infrastructure, such as our tanks, to make sure that our storage facilities are properly maintained," Engelskirger said.
It is still unclear how the water system was contaminated.
Pismo and Avila residents are asked to keep boiling water for at least one minute– or to use bottled water– for drinking, brushing teeth and cooking.
The county first issued the order Wednesday after routine tests of the Lopez Lake distribution system first detected E. coli, then on a second round of tests found coliform bacteria— not E. coli.
According to Public Works, on Friday, May 2, the Lopez water system tested negative for the bacteria. The department said the boil water notice for remaining areas could be lifted as early as Saturday if this trend continues.
In over 50 years of operation, this is the first time a boil water notice has been triggered for the Lopez Lake distribution system. Coliform bacteria can enter water systems through leaks, broken pipes or failing septic systems, according to the Environmental Protection Agency.
Drinking contaminated water can cause vomiting, diarrhea and other symptoms within two to four days. County officials urge people with severe symptoms to seek medical care.
The County will post updates at readyslo.org/wea.
