The Water Quality Program routinely collects ocean water samples every Monday, at 26 sampling sites extending from the Ventura/Los Angeles County border to south of the Redondo Beach pier. In addition, 5 samples are collected at Avalon Beach on Catalina from April through October. Samples are collected in the surf zone and analyzed by the Department of Health Service's laboratory for total coliform, E. coli and enterococcus bacteria.

The program also monitors and reviews ocean water monitoring results from the Los Angeles City, Bureau of Sanitation, Hyperion treatment plant and the Los Angeles County Sanitation District. The Hyperion treatment plant's laboratory makes available to our program daily bacteriological data for 19 shore stations, which are mainly adjacent to major storm drains. Water is analyzed for total coliform, fecal coliform and weekly for enterococcus bacteria. The Los Angeles County Sanitation District makes available, daily bacteriological data for 6 shore stations from Long Point to Outer Cabrillo Beach for total coliform and fecal coliform bacteria.

Beaches are posted with warning signs when bacteria levels exceed State ocean water quality standards. Beaches remain posted with warning signs until tests indicate that bacteria levels meet State standards.

Beaches are closed when a suspected or real sewage discharge to ocean waters occurs or elevated bacteriological levels can be linked to a known sewage discharge. Samples are collected from the affected areas and the beaches are kept closed until sampling data indicates that bacteria levels meet State standards.