APCD hearing board approves Oceano Dunes dust agreement

May 1, 2018

The San Luis Obispo County Air Pollution Control District (APCD) Hearing Board on Monday approved a hotly contested agreement between the APCD and California state parks over reducing dust flows coming from the Oceano Dunes. [Cal Coast Times]

State parks’ deal with the APCD will lead to the closure of portions of the Oceano Dunes to off-road vehicles in order to create islands of vegetation within the park. Presently, there are 186 acres of fenced vegetation islands on the dunes, according to a map circulated by the APCD.

The agreement requires particulate matter emissions to be reduced by 50 percent. The hearing board previously rejected a negotiated deal between the APCD and state parks that would have sought to reduce emissions by 30 percent.

Other conditions in the newly approved agreement include the formation of a scientific advisory group. The group is required to meet at least once a year to discuss emission reduction efforts.

For years, the APCD and Nipomo Mesa residents have clashed with state parks and off-road vehicle riders over Oceano Dunes dust flows. In 2011, the air district adopted the Oceano Dunes dust rule, which requires state parks to reduce the amount of particulate matter blowing from the dunes off-roading area or face fines of $1,000 per day.

In adopting the regulations, the APCD relied on contested studies that concluded off-road vehicles on the dunes were causing pollution on the Nipomo Mesa. The APCD also claimed that crystalline silica, which commonly appears in nature as quartz, made up a significant portion of the dust blowing onto the Nipomo Mesa and that it created a cancer risk for residents. However, the APCD did not release the results of its silica testing.

Meanwhile, state parks conducted its own crystalline silica tests and did release the results. State parks’ tests listed crystalline silica levels as below the detection limit.

Additionally, a 2018 report by the Scripps Institution of Oceanography at UC San Diego found that much of the dust blowing on the mesa is biological from the ocean and not the sand dunes.

On Monday, Nipomo Mesa residents and supporters of off-roading at the Oceano Dunes packed the SLO County Board of Supervisors chambers, where the APCD hearing board met. The deal between the APCD and state parks was met with opposition from both sides.

Nipomo residents argued the agencies involved are not doing enough to reduce emissions and air pollution on the Mesa. Supporters of off-road activity, who oppose further closures of riding areas, argued the APCD is continuing to use faulty science.

The hearing board then voted 4-1 to approve the agreement. The deal must now go before the California Coastal Commission before it is implemented by state parks.


They are trying to make a law to stop the wind from blowing.

The D***’s removed the trees that slowed the natural sand movement to increase their view.

Tough! They did it to themselves, the sand has been blowing for millions of years. That is what

they built their homes on. Did they think the sand would stop blowing? OH! That’s right they are D***’s

who are unable to understand the natural weather or action of wind, water, and climate?


I have to laugh…the repeated argument that it is dusty cuz the wind blows (and the implication that ORV’s do not contribute to higher dust levels) is just laughable. No wonder you all are sitting here whining about it; you are gonna lose every single policy development making decision if your only argument is “the wind blows, that’s why its dusty and sandy”. The level of scientific ignorance is stunning. But keep it up, makes for an easy win on the other side, the side of reality, that is.

Jorge Estrada

Sure, any disturbance gets the sand blowing. Natural turbulence in the wind is also a disturbance that kicks up the sand / dust. The real point is that those mountains of sand came from the ocean and will continue as a blend of geology, tidal activity, ocean currents and wind. The unavoidable fact is that new residents are being constructed in harms way for profit with the claim that eliminating the problem starts by the removal of people on the beach sands. That is not only laughable but truly a result of derelict governance.

Jorge Estrada

Build a housing tract near and airport then they want to close the airport. If that were to happen, the airport disclosure can be removed from their property record but if dune buggies are removed from an upwind beach, the toxic sand disclosure will never be removed from the property record. Surely the Scientific Advisory Group will put the down wind residents on notice, it would be the responsible thing to do now that (formally) negligence would be a liability. I smell litigation in the future, maybe against the agency that permitted the consequences, buggies or not.