IMPERIAL BEACH (NEWS 8/CNS) - Beaches near the U-S-Mexico border remain closed Monday due to sewage-contaminated runoff from the Tijuana River.

The shoreline was closed Sunday and remains closed from the border to the northern boundary of the Tijuana Slough National Wildlife refuge after testing showed unsafe water quality.

Officials also issued a precautionary advisory for the beach from the slough boundary to Carnation Avenue in Imperial Beach with both the closure and advisory set to remain in place until testing confirms water quality meets health standards, the agency said. 

The contaminated test came after a Friday morning incident in which a partial power failure at a Tijuana treatment facility allowed more than half-a-million gallons of water to flow through the Tijuana River across the border unhindered, according to the International Boundary and Water Commission. 

Officials sample the water quality in the area weekly, the environmental health department said, and sewage from the Tijuana River frequently results in closures during the winter rainy season.

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