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.
In Half Moon Bay, the beaches in Pillar Point Harbor at Westpoint Avenue by the green pier have been closed since Dec. 27, 2012, due to storm-related sanitary sewer overflows and will be closed until further notice.
According to the San Mateo County Resource Conservation District (RCD), a non-regulatory public benefit district to help people protect, conserve, and restore natural resources through information, education, and technical assistance programs, Pillar Point Harbor water quality is chronically so poor that the State Water Resources Control Board listed the location as impaired by coliform bacteria on the 303(d) list submitted to the United States Environmental Protection Agency.
Capistrano Beach has elevated levels of fecal indicator bacteria, such as E. coli and Enterococcus on more than 95 percent of sampling events in wet and dry conditions, according to a RCD study. This beach has been ranked for several years by the Heal the Bay's Report Card as a “Beach Bummer,” meaning that it is in the top 10 most polluted beaches in California in dry weather conditions.
The following locations have elevated levels of indicator bacteria and are posted with warning signs. This list was last updated Jan. 4, 2013, based on samples collected Wednesday morning:
- Linda Mar #5
- Pillar Point #8 (Maverick's Parking)
- Pillar Point #7 (Surf-Westpoint Ave)
- Pillar Point #5 (Capistrano Beach)
- Pillar Point #9 (Outer Harbor)
- Surfers Beach
- Roosevelt Beach
- Venice Beach
The following creeks, lakes, lagoons, bay beaches, ditches, and/or storm drains have elevated levels of indicator bacteria and have been posted:
- Creeks (where they meet or cross the beach)
- San Pedro Creek (at Linda Mar #5)
- Pilarcitos Creek (at Venice Beach South)
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 www.surfridersmc.org. 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.
Swimming in water that is contaminated by sewage, animal waste, chemicals, or other types of contamination can result in minor illnesses such as; skin rashes, eye and ear infections, and upset stomachs, or more severe and potentially life-threatening diseases such as cholera, hepatitis, and meningitis.
Sources of contamination include sewage and industrial waste discharges and contributions from residential sources such as storm drain runoff and domestic animal wastes. Sewage can come from failing septic systems, discharges to storm drains, or cracked or blocked sewer lines in sewered areas. Large concentrations of birds or marine mammals may also be sources of contamination, which result in illness.
In spite of the heavy recreational water use in San Mateo County, there have been very few reports of illnesses linked to water contact. Water-borne illnesses such as cholera and meningitis that have life-threatening impacts in other countries have not been shown to be a problem at local swimming areas.
Typical symptoms of the illness due to the presence of disease-causing organisms are: skin rashes, ear and eye infections, gastrointestinal upsets (diarrhea, nausea, stomach aches), open wound infections, continuing headaches
Signs closing these waters to recreational use have been posted and will remain until health and safety issues have been addressed.
You can also check for closures and postings on San Mateo County’s Beach/Creek Posting Hotline announcement at (650) 599-1266.
— Information provided by the San Mateo County Health System