Boil Water Notice Lifted in Four Communities; Two Communities Still Under Notice
Author: Public Works
Date: 5/2/2025 1:31 PM
FIVE CITIES – The State Division of Drinking Water has allowed the Boil Water Notice to be lifted for the cities of Arroyo Grande and Grover Beach, Oceano Community Services District, and San Miguelito Mutual Water Company as of 1:00 PM, Friday, May 2. The Notice will remain in effect for the city of Pismo Beach, Avila Beach Community Services District, and County Service Area #12.
The Notice can be lifted for these four communities for two reasons: 1) They were able to isolate their water system from the County’s Lopez Lake water distribution system and use other water supply sources; and 2) their other water supply sources have tested negative for bacterial contamination during the entire boil Notice.
The communities that remain under the boil Notice have also continued to test negative for bacterial contamination during the entire boil Notice, but they remain connected to the County's Lopez Lake water distribution system, which requires the Notice to remain in place. Test results of the Lopez Lake distribution system were negative today, which means the entire boil Notice could be lifted as early as Saturday, May 3, if those samples also test negative for bacteria. Until your local water agency lifts their Boil Water Notice, these safety measures remain in effect.
The boil Notice was issued on Wednesday, April 30, 2025, after one sample showed the presence of E. coli, with repeated samples only showing higher levels of total coliform bacteria, and not E. coli, in the County’s Lopez Lake water distribution system. Commonly found in the environment, Coliform bacteria are used as indicators of potential contamination. The repeated detection triggered a mandatory Boil Water Notice.
Notifications about the boil Notice have been sent to the affected communities through Reverse 911 and Alert SLO. You can sign up for either alert system at AlertSLO.org. An interactive map of the affected communities can be found at:
The communities that remain under the boil Notice have also continued to test negative for bacterial contamination during the entire boil Notice, but they remain connected to the County's Lopez Lake water distribution system, which requires the Notice to remain in place. Test results of the Lopez Lake distribution system were negative today, which means the entire boil Notice could be lifted as early as Saturday, May 3, if those samples also test negative for bacteria. Until your local water agency lifts their Boil Water Notice, these safety measures remain in effect.
The boil Notice was issued on Wednesday, April 30, 2025, after one sample showed the presence of E. coli, with repeated samples only showing higher levels of total coliform bacteria, and not E. coli, in the County’s Lopez Lake water distribution system. Commonly found in the environment, Coliform bacteria are used as indicators of potential contamination. The repeated detection triggered a mandatory Boil Water Notice.
Notifications about the boil Notice have been sent to the affected communities through Reverse 911 and Alert SLO. You can sign up for either alert system at AlertSLO.org. An interactive map of the affected communities can be found at:
https://slocooes.maps.arcgis.com/apps/instant/lookup/index.html?appid=e3b584fb770e438689b4483821187486
The public can also visit the websites and social media pages for each agency to obtain real-time information.
For homeowners or commercial operations with individual Reverse Osmosis (R/O) systems, please refer to the manufacturer’s user or owner’s manual for specific details on flushing the system.
In over 50 years of operation, this is the first time a Boil Water Notice has been triggered for the Lopez Lake distribution system. State officials are working onsite with the County of San Luis Obispo Public Works Department to identify what caused the increase in bacteria levels.
The Boil Water Notice identifies that the purpose of boiling water is to avoid intestinal illness. Residents with stomach or intestinal distress may seek care with their primary care provider or urgent care facility.
Restaurants may remain open during the Boil Water Notice if they comply with guidance found at ReadySLO.org/restaurantguidance, and are encouraged to contact County Environmental Health for guidance on complying with the notice at (805) 781-5544. County Environmental Health staff have already worked with over 150 businesses to help ensure they are able to comply with the guidance and remain open.
Please avoid calling fire or law enforcement for questions about the Notice. More information and updates can be found at ReadySLO.org/WEA.
The public can also visit the websites and social media pages for each agency to obtain real-time information.
For homeowners or commercial operations with individual Reverse Osmosis (R/O) systems, please refer to the manufacturer’s user or owner’s manual for specific details on flushing the system.
In over 50 years of operation, this is the first time a Boil Water Notice has been triggered for the Lopez Lake distribution system. State officials are working onsite with the County of San Luis Obispo Public Works Department to identify what caused the increase in bacteria levels.
The Boil Water Notice identifies that the purpose of boiling water is to avoid intestinal illness. Residents with stomach or intestinal distress may seek care with their primary care provider or urgent care facility.
Restaurants may remain open during the Boil Water Notice if they comply with guidance found at ReadySLO.org/restaurantguidance, and are encouraged to contact County Environmental Health for guidance on complying with the notice at (805) 781-5544. County Environmental Health staff have already worked with over 150 businesses to help ensure they are able to comply with the guidance and remain open.
Please avoid calling fire or law enforcement for questions about the Notice. More information and updates can be found at ReadySLO.org/WEA.
