PRESS RELEASE/WEEKLY NEWSLETTER. From the San Mateo County Health Department.
Water samples from natural recreational waters in San Mateo County are sampled each week for concentrations of indicator bacteria.
If concentrations of indicator bacteria exceed State or County standards, the area is posted to warn users that they may become ill if they engage in water contact activities in the posted area.
Join the Monday morning San Mateo County Volunteer Sampling Team and help protect beach users. For more information, see the Volunteer Opportunities in the FAQ section below.
To view current data and posted sites, please view the map here: San Mateo County Interactive Beach Map
The State Water Resources Control Board has statewide recreational water sampling locations and historical data available to the public: Safe to Swim Map
The following list was last updated Wednesday, July 28, 2021 based on samples collected Monday, July 26, 2021.
Certain beaches and creeks may not have been sampled this week due to closures or inaccessibility. Sites that were not sampled are shown in gray on the San Mateo County Interactive Beach Map (We are currently experiencing technical difficulties with the beach map. We are working to resolve this issue as soon as possible).
The following locations have elevated levels of indicator bacteria and are posted with warning signs.
- Linda Mar Beach at San Pedro Creek
- Pillar Point #8 (Maverick’s Parking)
- Pillar Point #7 (Surf-West Point Ave)
- Pillar Point #9 (Outer Harbor)
- Francis Beach (Kelly Ave)
CREEKS (WHERE THEY MEET OR CROSS THE BEACH)
- Pilarcitos Creek
- San Gregorio Creek
- Pomponio Creek*
- *This creek was not sampled due to it not breaching to the ocean. It will remain posted as a cautionary measure
- Erckenbrack Park
Signs limiting the recreational use of these waters have been posted and will remain in place until the level of indicator bacteria drop below State thresholds. You can also check for closures and postings on San Mateo County’s Beach/Creek Posting Hotline announcement at (650) 599-1266. Read on for more information on the County’s Recreational Water Quality Monitoring Program, including:
- Description of the County’s Monitoring Program
- Posting Criteria
- Explanation of Signs
- What Waters to Avoid
- Description of Exposure Symptoms
- Volunteer Opportunities
Recreational Water Quality Monitoring in San Mateo County
Thousands of people use San Mateo County swimming areas annually. On any one day, people can be found swimming, surfing, body-surfing, diving, or just walking through the water’s edge at any of the Ocean or Bay water beaches in San Mateo County.
Generally, these waters are clean and safe for swimming. However, to ensure public health and safety, San Mateo County Environmental Health Services, with the help of volunteer samplers, regularly test these waters for contamination. If problems are found the public is notified and steps are taken to control the source of contamination.
San Mateo County routinely tests 43 sites each week, including ocean beaches, creek mouths (where the creek meets or crosses the beach), and Bay/lagoon beaches. Sites are sampled every Monday morning by a combination of County staff and volunteers, primarily associated with the local chapter of the Surfrider Foundation. The County evaluates the potential presence of disease-causing organisms by testing for “indicator” bacteria. When high indicator bacteria levels are found, the site is posted with a warning sign and is re-tested to confirm the results.