Top 10 most polluted beaches in California include 6 from San Mateo County

Photo of the San Mateo County coastline. Duncan Sinfield/KTVU.

San Mateo County beaches accounted for six of the top 10 most polluted beaches of the state, according to a list released Tuesday by the environmental advocacy group Heal the Bay.

Heal the Bay's 30th annual Beach Bummer list ranks the most polluted beaches in the state on their levels of harmful bacteria in ocean water. The group monitored more than 500 beaches across the state to compile lists of the most and least polluted beaches.

San Mateo County's Fitzgerald Marine Reserve in Moss Beach was deemed the most polluted beach in the state due to polluted runoff from San Vicente Creek, according to Heal the Bay. Fitzgerald Marine Reserve has never appeared on a Beach Bummer list until this year.

Pillar Point Harbor at Capistrano Avenue in Half Moon Bay, Erckenbrack Park in Foster City, Pillar Point Harbor Beach, Linda Mar Beach at San Pedro Creek and Pillar Point Harbor at Westpoint Avenue were also listed among the 10 most polluted beaches in the state. 

The group noted that the Pillar Point Harbor locations were all affected by pollutants from multiple storm drains that flow into the enclosed harbor.

"A day at the beach shouldn't make anyone sick," Heal the Bay president and CEO Shelley Luce said in a news release. "We are glad to see water quality improving at some beaches, but there are no guarantees."

San Mateo and Monterey counties both had beaches deemed among the best in the state on Heal the Bay's 2019-2020 Honor Roll list. Beaches qualify for the list if they are monitored weekly year-round and earn perfect marks for their water quality.

The list of 42 beaches is dominated by those in Southern California because northern and central California counties generally don't monitor water quality all year, according to Heal the Bay.

However, Monterey County's Asilomar State Beach at Arena Avenue, Monterey State Beach and Spanish Bay beach at 17 Mile Drive and San Mateo County's Bean Hollow State Beach all qualified for the group's Honor Roll. All four beaches made the list for the first time. 

"We know that our work is far from over," Heal the Bay said in its report. "With the numbers of people depending on the ocean for their recreation and livelihoods increasing, it is more important than ever to protect our water quality and our beaches."

Beachgoers can visit to view the complete beach water quality report. The latest water quality grades for beaches across the state can be found at