Viewpoint: Dust emission rule’s passage is an issue of public health

Much has been aired on this page and on the radio over the past week regarding the Air Pollution Control District’s proposed rule to reduce dust emissions from the Oceano Dunes, and the scientific studies supporting the rule. Most of it involves a very strong lobbying and misinformation campaign by those opposed to the rule, raising questions in the guise of “science” to create doubt and undermine our credibility. As a result, APCD has been pulled into a whirlwind of accusations, character attacks and untruths.

This is unfortunate and detracts from the real issue: the ongoing and significant health risks faced by South County residents exposed to the huge dust plume rising from the Dunes on windy days. Protection of public health is not a choice for APCD — it’s our mandate. I completely agree with Judith Bean’s statement in her Viewpoint article that decisions must be made on information that goes beyond hearsay.

Here are the facts:

Airborne particulate matter (PM) levels on the Nipomo Mesa are consistently higher than anywhere on the California coast, including other dune areas, exceeding state health standards about 65 days per year; those standards are rarely exceeded elsewhere in our county. APCD performed a comprehensive year-long air quality study beginning in 2004 to evaluate possible sources of PM emissions impacting the Mesa, including dirt roads, agricultural activities, nearby industry, highway emissions and coastal dunes. The data definitively identified the coastal dunes as the primary source of PM on days when the health standards were exceeded; the study was not designed, however, to evaluate whether off-road vehicle activity on the Oceano Dunes was a contributing factor. The APCD Board thus directed staff to conduct a second study for that purpose.

APCD contracted with the UC Davis Delta Group to help design and implement the new study, a team of internationally recognized experts in particulate aerosol analysis that was also relied upon by the EPA to analyze the PM concentrations and exposure to workers and residents at ground zero after the World Trade Center attacks of 9/11. Air monitoring and meteorological experts from two other air districts, soil experts from University of Texas, and geologists and staff from State Parks also played important roles in designing and carrying out the Phase 2 PM Study.

The project involved three independent studies conducted by three independent groups to analyze sand movement, particle size and composition, and airborne particulate levels from the riding area and a comparable non-riding area selected by State Parks. After collecting and analyzing more than 2 million data points generated by the sampling, all three studies were peer reviewed and independently reached the same conclusion: Vehicle activity on the Dunes is significantly contributing to the high PM levels on the Mesa.

Attacks on the study began before it was even published and continue to this day. APCD staff and its consultants spent considerable time and effort thoroughly analyzing and answering all questions raised, reaffirming our confidence in the validity of the findings. It’s time to move forward. The proposed rule is fair, requiring dust from the Dunes to be reduced to natural background levels using best management practices selected by State Parks; we have worked collaboratively with them over the past 18 months to evaluate potential solutions. The recent pilot projects performed at the Dunes by scientists from the Desert Research Institute, as well as substantial other research in this field, demonstrate a variety of strategies are available to reduce the dust emissions without significantly affecting operations at the park.

As a regulatory agency charged with public health protection, we are obligated to ensure those reductions occur in a timely manner. The proposed rule is the appropriate means to accomplish that goal. APCD has spent nearly a decade, countless staff hours and considerable funds researching this issue while exposure to harmful levels of pollution continues for downwind residents. Our mandate is clear, and we will strongly recommend that our board adopt the proposed rule.

Implementing regulations is a collaborative process. We work closely with hundreds of other facilities and businesses subject to air quality regulations in our county to help them meet their requirements in a feasible and practical manner. We don’t shut them down, and we don’t penalize them out of existence if they fall out of compliance — we work with them to find the best path forward in solving the problem while ensuring public health is protected. That’s how we’ve always functioned, and that’s the relationship we’ll establish with the park operators.

Larry Allen is executive director of the San Luis Obispo County Air Pollution Control District.