San Diego County beaches top list of California's dirtiest beaches due to Tijuana River sewage

Hampered in part by winter storms, water quality declined at beaches across California in 2023-24, according to an annual report released Wednesday by an environmental group, which placed the Tijuana River Mouth in the top spot on its dreaded "Beach Bummer" list.

The annual Beach Report Card released by Heal the Bay assigns letter grades of A through F to beaches based on bacterial pollution levels. The report rates 700 Pacific Coast beaches stretching from Washington to Baja.

According to the report, 89% of California beaches received A or B grades during the dry-weather summer months, a 6% decline from last year. Southern California beaches fared about the same as those statewide, with 90% of them receiving A or B grades.

Heal the Bay's annual Beach Bummer list

Heal the Bay ranked the west coast's 10 most-polluted beaches in Summer Dry Weather from 2023 to 2024. Four San Diego County beaches unfortunately made the cut.

1. Tijuana River Mouth (San Diego County)
2. Playa Blanca (Baja, Mexico)
3. Santa Monica Pier (Los Angeles County)
4. Tijuana Slough (San Diego County)
5. Linda Mar Beach (San Mateo County)
6. Lakeshore Park (San Mateo County)
7. Imperial Beach at Seacoast Drive (San Diego County)
8. Border Field State Park (San Diego County)
9. Marina del Rey Mother’s Beach (Los Angeles County)
10. El Faro (Baja, Mexico)

During the winter season, however, only 66% of California beaches received overall A or B grades, according to the report, which noted that the state received 31% more rainfall during the reporting period than the 10-year average.

"Eighty-nine percent of California beaches were safe to swim at during summer 2023, but we are still seeing water quality impacts from record- breaking storms, urban runoff and sewage spills," Tracy Quinn, Heal the Bay's CEO and president, said in a statement. "California's 20th century water infrastructure was not designed to address the challenges faced by climate change in the 21st century. We need to upgrade outdated sewage treatment facilities and prioritize public investment in nature-based, multi-benefit stormwater capture infrastructure."

Four San Diego County beaches made the Beach Bummer list, and -- along with two beaches in Baja California -- all of them are directly adjacent to the Tijuana River and its years-long sewage and pollution problem. Besides the Tijuana River Mouth topping the list, the Tijuana Slough was fourth, Imperial Beach at Seacoast Drive was seventh and Border Field State Park was eighth. Playa Blanca and El Faro -- either in or adjacent to Tijuana -- came in second and 10th, respectively.

Toxic Tide: The sewage crisis at the border

NBC 7 investigates the millions of gallons of raw sewage crossing from Tijuana into the United States every day, including how the crisis affects our health — and what must be done to end it.

"The Beach Bummers in San Diego County and Baja all suffer from persistent sewage issues," Heal the Bay wrote. "The Tijuana River annually discharges tens of millions of gallons of untreated sewage into the ocean, originating from inadequate sanitation infrastructure in Tijuana.

"Enhancements are underway, including the U.S. EPA-funded upgrades to the Punta Bandera treatment plant and the South Bay International Wastewater Treatment Plan. Heal the Bay advises against swimming at these beaches until the upgrades are completed, which may take a decade or more," the group added.

Overall, 12 beaches in the state landed spots on Heal the Bay's coveted Honor Roll, meaning they received A+ grades throughout the summer and winter reporting seasons. That's up from just two that made the list last year, but noticeably down from the traditional 30-50 beaches that normally earn perfect scores.

Of the 12 beaches on the Honor Roll, nine are in Orange County. Two San Diego County locations -- Point Loma Lighthouse and Encinitas Moonlight Beach -- landed on the Honor Roll, along with County Line Beach in Ventura County.

California's cleanest beaches on Heal the Bay's 'honor roll'

1. Dana Point Harbor Fuel Dock (Orange County)
2. Huntington Harbor, Seagate Lagoon (Orange County)
3. Huntington Harbor, Trinidad Lane Beach (Orange County)
4. Newport Bay, Promontory Point (Orange County)
5. Dana Point, South Capistrano Bay Community Beach (Orange County)
6. Riviera Beach (Orange County)
7. Emerald Bay Beach (Orange County)
8. Marine Science Institute Beach (SERRA) (Orange County)
9. Salt Creek Beach (Orange County)
10. Point Loma, Lighthouse (San Diego County)
11. Encinitas, Moonlight Beach, Cottonwood Creek (San Diego County)
12. County Line Beach (Ventura County)