The environmental nonprofit's 2025-26 report placed the Pier second on its annual "Beach Bummer" list of beaches with the poorest summer dry- weather water quality grades because of elevated bacteria levels and chronic pollution concerns.
Playa Blanca near Tijuana ranked as the state's most polluted beach, while the Tijuana Slough at the Tijuana River Mouth in San Diego County also made the top 10 list.
The report's Beach Bummer rankings were:
-- 1. Playa Blanca near Tijuana;
-- 2. Santa Monica Pier;
-- 3. Erckenbrack Park in San Mateo County;
-- 4. Linda Mar Beach at San Pedro Creek in San Mateo County;
-- 5. Parkside Aquatic Park in San Mateo County;
-- 6. Pillar Point Harbor's Capistrano Road Beach in San Mateo County;
-- 7. Pillar Point Harbor's Harbor Beach in San Mateo County;
-- 8. Marlin Park in San Mateo County;
-- 9. Tijuana Slough at the Tijuana River Mouth in San Diego County; and
-- 10. Clam Beach County Park at Strawberry Creek in Humboldt County.
According to Heal the Bay, California beaches overall maintained relatively strong water quality, with 91% earning A or B grades during summer dry conditions. However, statewide wet-weather grades declined from 67% to 61% because of rainfall, stormwater runoff and aging infrastructure, according to the report.
"No one should get sick from a weekend in our waters," Heal the Bay CEO Tracy Quinn said in a statement. "These findings are a reminder that water quality isn't just a report, it's a public health issue that affects every beachgoer and river user across California."
The organization also released its annual River Report Card, which identified recurring freshwater pollution hotspots in urban sections of the Los Angeles River watershed. The worst grades were recorded near the Rio Hondo confluence and Hollydale Park along the lower Los Angeles River.
The report's "Freshwater Fails" rankings for sites receiving annual F grades were:
-- 1 (tie). Los Angeles River below the Rio Hondo Confluence in the Lower Los Angeles River watershed;
-- 1 (tie). Los Angeles River at Hollydale Park in the Lower Los Angeles River watershed;
-- 2. Los Angeles River below the Compton Creek Confluence in the Lower Los Angeles River watershed;
-- 3. Los Angeles River at Willow Street in the Lower Los Angeles River watershed;
-- 4. Eaton Wash at Sierra Madre Boulevard in the Upper Los Angeles River watershed;
-- 5 (tie). Santa Anita Wash at Colorado Boulevard in the Upper Los Angeles River watershed;
-- 5 (tie). the Los Angeles River at Riverfront Park in the Lower Los Angeles River watershed;
-- 6. Compton Creek in the Lower Los Angeles River watershed;
-- 7. Tujunga Wash at Hansen Dam in the Los Angeles River watershed recreation zones;
-- 8. Arroyo Seco at Brookside Golf Course in the Upper Los Angeles River watershed; and
-- 9. Bull Creek in the Upper Los Angeles River watershed.
Heal the Bay said 21 beaches statewide earned Honor Roll status for receiving A-plus grades in all monitored weather conditions, down sharply from 62 beaches the previous year. Los Angeles County's Bluff Cove in Palos Verdes Estates was among the beaches receiving top marks.
The report urged beachgoers to avoid swimming within 72 hours after rainfall and to stay away from storm drains, river outlets and stagnant water areas.