SAN DIEGO (CNS) - An influx of storm-driven sewage out of Baja California prompted authorities Wednesday to expand an existing ocean-contact 
warning in the area of Tijuana Slough National Wildlife Refuge north to include the entire shorelines of Imperial Beach and the Silver Strand.
   
The advisory stems from contamination that has entered the United States via the Tijuana River following recent rains, according to the San Diego County Department of Environmental Health.
   
Signs warning of pollution hazards will stand along beaches from the U.S-Mexico line to Avenida Lunar in Coronado until follow-up testing deems them safe again for recreational uses.