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San Luis Obispo County, California


Ocean Water Monitoring Results

Japan Tsunami Debris Radiation Testing

Radiation testing results of beach debris from the 2011 Japan Tsunami will be posted on this website as they become available. The public is advised to contact Environmental Health Services at 805-781-5544 when significant Japan Tsunami debris washes ashore on SLO County beaches View test results.



Environmental Health Services takes ocean water samples at nineteen locations along the coast on a weekly basis. (Sampling locations are listed below.) Samples are analyzed for three types of indicator bacteria, which at sufficient concentrations indicate the potential presence of microbes that may cause human illness. A ratio of two of the three bacteria types are analyzed as well.  The results are compared to standards established by the State. If any of the State standards are not met, a Health Advisory is issued. A Health Advisory warns bathers to avoid water contact activities due to the presence of elevated levels of bacteria. An advisory spans fifty yards north and south of the area where the sample is collected. Beaches are posted with advisory signs and remain posted until sample results indicate that bacteria levels meet State standards.

A beach closure occurs when a specific beach location is closed to all water contact activities due to a higher health risk associated with known hazardous waste spills, such as untreated sewage reaching recreational waters.

San Luis Obispo County Environmental Health Services is committed to report on the testing of radioactivity of Japan tsunami debris that may wash ashore on SLO County beaches. The test results can be viewed by clicking here.

This website is updated when weekly sample results become available. This information is also available on our hotline (805) 788-3411.


Current Alerts and Advisories 


 There are no sewage spills or beach closures at this time.

Effective July 1, 2015 Environmental Health Services will no longer be taking a sample at the "HAZ 10" (Montana de Oro / Hazard Canyon) location due to revised sampling criteria.