Asbestos is commonly found in ultramafic rock, including serpentine, near fault zones and is released into the air when it is broken or crushed. This can happen when land is graded for building purposes, or at quarrying operations. The state of California has determined that NOA, such as serpentine rock, is a toxic air contaminant and if inhaled may result in the development of lung cancer or cause other health hazards. Work in serpentine areas requires a District pre-approved dust control plan and may include asbestos air monitoring.
The California Air Resources Board has identified asbestos as a toxic air contaminant. In San Luis Obispo County, serpentine rock is located in many regions of the county including: coastal, coastal mountain, western north county and the extreme eastern county area along the San Andreas Fault. Under the ARB's Air Toxics Control Measure (NOA ATCM) for Construction, Grading, Quarrying, and Surface Mining Operations, prior to any grading activities at a site within the green “buffer” areas on the APCD NOA map, the Owner or Operator will be required to comply with the applicable sections contained in the NOA ATCM. For those projects within the NOA Planning area (green areas), the following requirements apply.
For grading projects qualifying for NOA ATCM exemption:
Submit NOA Exemption form with geologic evaluation.
For grading projects in serpentine rock less than 1 acre:
Submit Project Form with geologic evaluation.
Mini Dust Control Measures (93105.e.(A-F).
For grading projects in serpentine rock greater than 1 acre:
The San Luis Obispo County Air Pollution Control District (APCD) will assess Review Fees for all work that has the potential to disturb soil containing Naturally Occurring Asbestos (NOA).
NOA Project Review Fee amounts depend upon the project size and if projects involve disturbance of asbestos serpentine, and include dust mitigation plans or air monitoring. Exemptions from requirements are available based on geological evaluation. Please refer to the fee schedule for more information.