Oceano Dunes pollution study gets tentative OK

Tribune file photo by Joe Johnston

The county Air Pollution Control District board struggled Wednesday to agree on what to do about high particulate pollution on the Nipomo Mesa in light of a scientific study linking the dust to the Oceano Dunes State Vehicular Recreation Area.

After hours of public comment and discussion, the board voted 9-1 to officially receive the study and told air district staff to come up with a list of ways to lessen the pollution. Pismo Beach City Councilman Kris Vardas voted no, saying that too many questions about the validity of the study had been raised.

By receiving the report, the board tentatively accepted the findings of the study that off-highway vehicle riding in the state park destabilizes the sand dunes and allows strong ocean winds to carry small sand particles inland to the Mesa.

However, many board members told Air Pollution Control Officer Larry Allen that they want his staff to analyze critiques of the report to determine whether further study needs to be done. The board also told its attorney, Rex Biering, to come back with a report on the board’s authority to require air pollution mitigation measures.

“Receiving and filing the report is not the end of the process,” Supervisor Katcho Achadjian said.Thomas Cahill, an air pollution researcher at UC Davis and one of the study’s consultants, said a combination of revegetation and putting up sand fences proved effective in minimizing a dust pollution problem at Owens Lake, a dry lake in Inyo County. The fences could be as low as 3 feet tall and cost about $70,000.

About 60 members of the public also spoke at the meeting.

Many were Nipomo Mesa residents, particularly of Cypress Ridge, who complained of asthma, bronchitis and eye infections that they attributed to the poor air quality. Some asked that the air board declare a moratorium on riding at the park until the pollution problem can be reduced.

Much of the meeting was also spent debating the scientific validity of the study. Pismo Beach City Councilman Ed Waage, the state Parks Department and pro-OHV riding group Friends of Oceano Dunes have sent lengthy letters criticizing many aspects of the study.

“The assumptions and content of the study are not substantiated by the facts,” said Andy Zilke, Oceano Dunes superintendent.

For example, Waage said that the topography of the Dunes is creating a “river of clean air” leading to the air sampling station south of the riding area that was used in the study to measure dust coming off areas of the park closed to riding.

Allen and several of the board members, including county Supervisor Bruce Gibson, rejected these criticisms, saying the study clearly shows air quality is much worse downwind of the riding area even when variables and margins of error are factored in. Particulates on the Nipomo Mesa violate state air standards 40 to 60 days per year.

In the end, the board members agreed that public health should trump all other concerns. Several of the board members, most notably Vardas, said the board could not ignore the importance of Oceano Dunes to the economy of the South County.