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Naturally Occurring Asbestos (NOA)

Like many counties in Northern California Mendocino County has areas that contain Naturally Occurring Asbestos (NOA). State regulations, enforced by the District  may affect quarries, grading and surfacing projects.


NOA Grading and Surfacing Application Process and Forms

Outline of the NOA application process

NOA Dust Mitigation Plan Application (and exemption request)


NOA Links

Copies of the State NOA Regulations 17 CCR 93105 and 93106

California Air Resources Board Web Page for Naturally Occurring Asbestos

USGS Flyer on Asbestos

Letter from Office of Planning and Research on how to deal with Naturally Occurring Asbestos in CEQA documents 

District NOA Policy



The District, working with other agencies, has produced a series of  maps of areas likely to contain NOA in Mendocino County. These maps are not parcel specific and only shows areas where NOA is more likely, the actual presence of NOA can only be determine by an expert.


NEW! Google Earth NOA map

MAP of likely areas to contain NOA in Mendocino County

MAP of the Ukiah Area

MAP of the Willits Area

MAP of the Hopland Area




Under 17 CCR 93105 & 93106, only a State Registered Geologist can document that property is free of Naturally Occurring Asbestos. The District cannot recommended any particular Geologist, but the state Department of Consumer Affairs does provide a searchable online database of Registered Geologists.

Searchable Database of Registered Geologists

MCAQMD Geologic Evaluation Guidelines (for consultants)



Contact the District (707) 463-4354 with any questions.

    Last Update 04/01/2011