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Last Edited: 5/20/2010

Klau/Buena Vista Mines, San Luis Obispo County - Public Health Activities

From 2005 to 2010 the California Department of Public Health (CDPH) conducted an investigation of the public health implications from contamination at the Klau and Buena Vista Mines.

The site

The Klau and Buena Vista Mines are located in San Luis Obispo County, about 12 miles west of Paso Robles. The mines cover about 250 acres, including 5 miles of underground workings, approximately 300,000 tons of mine tailings, overburden, waste rock, and several rundown buildings. The mines have contributed significant levels of mercury to downstream waters, and they were named to the National Priority List in April 2006. The U.S. Environmental Protection Agency (EPA) is the lead agency for the cleanup at the site.

The Environmental Health Investigations Branch of CDPH (formerly the California Department of Health Services) is working with other agencies involved at the site, such as the EPA and the County of San Luis Obispo. View a brochure that explains agency roles and ways the community can get involved.

Evaluation of contaminants at the mines

On April 1, 2010, ATSDR and CDPH released the Public Health Assessment (PHA) report for the Klau and Buena Vista Mines. The PHA contains a review of environmental data to evaluate the potential health impact from exposures to contaminants found at the mines, a description of health concerns collected from community members, and an evaluation of these health concerns based on the environmental data review. 

What did CDPH's evaluation find?

In the PHA, CDPH evaluated possible ways people could be exposed (exposure pathways) to the contamination from the site, and concludes that while some exposure pathways and activities would not be expected to harm people’s health, others would have potentially been a public health hazard. View the findings of the pathway evaluation.

CDPH strives to protect the public from current and future exposure at the site by making recommendations in the report to the overseeing cleanup agency and other responsible parties, such as restricting public access to the mines and conducting additional soil, sediment, and water sampling. View the recommendations.

Evaluation of fish contamination at Lake Nacimiento

In March 2006, CDPH staff collected more than 150 fish from Lake Nacimiento to assess mercury levels. Mercury levels were high in all fish species at the lake. As a result of this investigation, we worked with the County of San Luis Obispo to develop safe consumption guidelines for Lake Nacimiento fish. An interim fish advisory was released in February 2007 to the greater community of San Luis Obispo. See the report of the work we conducted at the lake: Health Consultation "Evaluation of Fish Consumption from Lake Nacimiento [2/6/07]

In March 2009, the Office of Environmental Health Hazard Assessment (OEHHA), of the California Environmental Protection Agency, released an update of California sport fish advisories, including specific recommendations for Lake Nacimiento fish. View the advisory and learn more about mercury contamination.

Evaluation of mercury exposure and physical hazards

During a May 10, 2005 site visit, CDPH staff observed elemental mercury (quicksilver) in the vicinity of the dilapidated Buena Vista Mill buildings (Pictures of the Buena Vista Mill). Staff prepared a Health Consultation pertaining to imminent hazards present at the Buena Vista Mine. Specifically, we requested that EPA and the Department for Toxic Substances Control conduct interim actions to post warnings and put a fence up at the Buena Vista Mine to prevent access to the mill works at Buena Vista Mine. See the report of the work we conducted at the mine: Health Consultation "Evaluation of Mercury Exposures and Physical Hazards" [9/23/05]. 

Note. If you would like to receive a hard copy of any of these reports, please contact Nancy Palate, Health Educator at (510) 620-5845.

Related Topics


Project Location

  • CA Counties: San Luis Obispo