NOA Construction & Grading

Areas mapped and indicated by the California Department of Conservation, California Geological Survey (CGS) as having a greater likelihood for the presence of Naturally-Occurring Asbestos require dust control when the earth is disturbed. The State’s Asbestos Airborne Toxic Control Measure for Construction, Grading, Quarrying, and Surface Mining Operations (ATCM), District Rule 228, Fugitive Dust (PDF), and Naturally-Occurring Asbestos Dust Mitigation Plan (ADMP) Guidance (PDF), finalized May 1, 2010, establish requirements in addition to the standard dust control measures.

Note that for Construction and Grading projects occurring in areas with a lower probability for the presence of Naturally Occurring Asbestos (NOA), where greater than one acre will be disturbed, and if established as a Condition of Approval of a discretionary permit, a Dust Control Plan is required. Further information may found on the Construction and Grading Dust Control Requirements (PDF) and Dust Control Plan Instructions and Application (PDF). Use of the Dust Control Plan Instructions and Application (effective date of May 11, 2010) form is encouraged as submission of an original plan may be subject to increased fees if additional review time is required in the approval process.

Dust Control Requirements for High NOA Area Projects with Greater Than One Acre Disturbed Area 

For disturbed surface areas greater than one acre and residing in an Area Most Likely to Contain NOA as identified using the District NOA Hazard map found on the NOA Maps and Resources page, or designated as a High NOA zone in plus, before a Grading Permit will be issued, and/or within 14 days of the discovery of NOA, ultramafic rock, or serpentine rock in the area to be disturbed after earth-disturbing activities have been initiated, an ADMP must be submitted to the District for approval. Use of the ADMP Guidance Application form (PDF) is encouraged as submission of an original plan will be subject to increased fees due to additional review time required in the approval process. Dust controls must be implemented at the initiation of earth-disturbing activities, or upon the discovery of NOA, ultramafic rock, or serpentine rock, and maintained throughout the duration of construction and grading activities. The Agency for Toxic Substances and Disease Registry (ATSDR) Fact Sheet for workers involved in activities that disturb soil or generate dust in areas with naturally-occurring asbestos is available.

View the NOA Dust Mitigation Plan Flowchart (greater than one acre) (PDF).

Dust Control Requirements for High NOA Area Projects with One Acre & Less Disturbed Area

Minimum standards for dust control must be implemented for disturbed areas under one acre in “Most Likely” to contain NOA areas, and must be implemented within 24-hours of the discovery of NOA, ultramafic rock, or serpentine rock in the area to be disturbed after earth-disturbing activities have been initiated. Please consult the Asbestos Airborne Toxic Control Measure for Construction, Grading, Quarrying, and Surface Mining Operations (ATCM) or the District Naturally-Occurring Asbestos Dust Mitigation Plan (ADMP) Guidance (PDF), and District Rule 228, Fugitive Dust (PDF) for the minimum dust control standards required. View the Agency for Toxic Substances and Disease Registry (ATSDR) Fact Sheet for workers involved in activities that disturb soil or generate dust in areas with naturally-occurring asbestos.

Access the NOA Dust Mitigation Plan Flowchart (less than one acre) (PDF).