Huntington Harbour was shut down on Thursday after a blocked sewer main sent 60,000 gallons of sewage spilling into the water.
The sewer main blockage happened in the city of Stanton, according to the Orange County Health Care Agency.
The closure encompasses Anaheim Bay, Sunset Aquatic Marina, Portofino Cove, Anderson Street Marina and Mother's Beach.
The water is closed to swimmers, surfers and paddle boarders until testing determines the water quality is safe again. Officials did not provide an estimate for reopening.
For more information, you can contact the Orange County Health Care Agency at (714) 433-6400