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 can be released into the air when asbestos-bearing rock or soil is disturbed. The application, mapping, and professional resources below can help project owners determine which requirements may apply before work begins.

Review the District process before submitting a dust mitigation plan or requesting an exemption.

• State NOA Regulations: 17 CCR 93105 and 17 CCR 93106
• California Air Resources Board web page for Naturally Occurring Asbestos
• USGS flyer on asbestos
• Office of Planning and Research guidance for NOA in CEQA documents
• District NOA Policy

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

• Google Earth NOA map
• Mendocino County map of areas likely to contain NOA
• Ukiah area map
• Willits area map
• Hopland area map

Under 17 CCR 93105 and 93106, only a State Registered Geologist can document that a property is free of Naturally Occurring Asbestos. The District cannot recommend a particular geologist, but the California Department of Consumer Affairs provides a searchable license database.

• Searchable database of Registered Geologists
• MCAQMD Geologic Evaluation Guidelines (for consultants)
• Guidelines for Geologic Investigations of Naturally Occurring Asbestos in California SP-124 (for consultants)

Questions? Contact the District at (707) 463-4354.