The Oceano Dunes State Vehicle Recreation Area (SVRA) emits significantly more particulate matter (PM) dust than the natural background emission levels measured in non-riding dune areas. This fact is apparent in the aerial photograph (left) of the Nipomo Mesa. The visible, concentrated dust plume originates from the SVRA riding area and extends over the southwest part of the mesa. No plume is visible north or south of this.Unnatural PM concentrations are emitted from the Oceano Dunes SVRA any time there is on-shore wind. However, during periods of high wind the concentrations frequently exceed the PM10 and PM2.5 health standards established by the California Air Resources Board, and violate the San Luis Obispo County Air Pollution Control District (APCD) Rule 1001. On June 12, 2017 the APCD Air Pollution Control Officer issued a Notice of Violation to the State Parks OHMVR Division Acting Deputy Director.PM dust pollution levels are measured by the APCD at several monitoring sites in the South County area. The data from these sites is used to issue forecast PM pollution alerts, and to document violation of air quality standards.
Report summarizing Phase 1 and Phase 2 South County PM Studies. Conclusion: Off-Highway vehicle activity in the SVRA is a major contributing factor to the high PM concentrations observed on the Nipomo Mesa.