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.

Other water quality news:

• Los Angeles Times: Santa Monica Pier area among the dirtiest beaches again in new Beach Report Card
• Heal the Bay: News release: Annual beach and river report cards 2025-2026
• Ebb and Flow (California Water Boards): Blog: That bright green water? What to know about harmful algal blooms before you venture in​