As soon as the weather dries out, three weeks of testing and monitoring will begin at Oceano Dunes State Vehicular Recreation Area that may reveal a way to stop unhealthy amounts of sand particles from blowing onto the Nipomo Mesa.
Larry Allen, county air pollution control officer, said at least five days without rain are needed to sufficiently dry out the sand at the park to begin testing. The most likely start date is April 11, he said.
The testing will consist of placing devices that measure sand movement in various places in the park. Researchers will compare sand movements in open areas inside and outside the park’s riding sections, as well as in vegetated areas and in a large area strewn with straw bales, Allen said.
Researchers are hoping to determine if replanting parts of the park or deploying hay bales to break up wind gusts will reduce particulate emissions to levels within state health standards. Springtime was selected for the testing because that is windiest time of year.
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On Wednesday, the county Air Pollution Control District board approved the testing as well as a new cooperative agreement between the air district, state parks and the county. The new agreement is intended to streamline the work of mitigating blowing dust, Allen said.
A recent scientific study by the air district showed that riding within the park breaks up sand dunes, making it easier for particles to become airborne. Air quality on the Nipomo Mesa downwind frequently exceeds state standards for particulates.
Allen said he is optimistic a way to reduce sand emissions can be found. The techniques to be tested in the Oceano Dunes have been used in the Owens Lake area of eastern California to reduce blowing dust by 90 percent.
Several Mesa residents complained Wednesday that it has taken a year to get the testing under way, during which time riding in the dunes has continued uninterrupted. Residents say a brown haze blows over the Mesa on windy days, forcing them to stay indoors.
Supervisor Bruce Gibson, who chairs the air board, said he sympathizes with the frustration of Mesa residents, but added it has taken “an extraordinary amount of effort to get us to this point.”