Sewage-contaminated runoff from the Tijuana River forced beach closures Sunday near the U.S.-Mexico border.
The shoreline from the border to the northern boundary of the Tijuana Slough National Wildlife Refuge was closed after testing showed unsafe water quality, according to the San Diego County Department of Environmental Health.
Officials also issued a precautionary advisory for the beach from the refuge boundary to Carnation Avenue in Imperial Beach.
The closure and advisory will remain in place until testing confirms water quality meets health standards, the agency said.
The unhealthy water quality comes after a Friday morning incident in which a partial power failure at a treatment facility in Tijuana allowed an estimated 560,000 gallons of water to flow through the Tijuana River across the border unhindered, according to the International Boundary and Water Commission.