The Tijuana Slough at the Tijuana River Mouth ranked among California's most polluted beaches, while Playa Blanca near Tijuana was listed as the state's worst beach in Heal the Bay's annual Beach Report Card released Wednesday ahead of Memorial Day weekend.
The environmental nonprofit's 2025-26 report placed the Tijuana Slough ninth 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.
According to Heal the Bay, Playa Blanca and the Tijuana Slough continue to be heavily impacted by transboundary wastewater flows from Baja California, although efforts are underway on both sides of the border to reduce sewage discharges and improve infrastructure.
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
10. Clam Beach County Park at Strawberry Creek in Humboldt County