State Parks and San Luis Obispo County air quality officials say they are making progress in resolving their disagreement over controlling unhealthy dust levels on the Nipomo Mesa, but the results of a new study by the air district shows that dusty air from Oceano Dunes often blows as far inland as Santa Maria.

In recent months, Larry Allen, county air pollution control officer, has criticized the Off-Highway Motor Vehicle Recreation Division of State Parks for its lack of progress in taking steps to reduce blowing dust on the Oceano Dunes State Vehicular Recreation Area as well as an overemphasis on monitoring.

At a meeting Wednesday of the Air Pollution Control District board of directors, Allen said communication has improved between the two agencies and that State Parks has agreed to speed up meeting some important goals set down in the district’s dust-control rule. The two agencies are also working on expediting the state Coastal Commission permitting process.

Coastal Commission permission will be needed to implement some on-the-ground techniques for minimizing blowing dust, such as installing hay bales and wind fences. A study by the air district concluded that off-highway vehicle driving on the Dunes was responsible for worsening particulate pollution on the Nipomo Mesa.

“We feel like we’ve been working hard on this issue for a long time,” said Phil Jenkins, director of State Park’s Off-Highway Motor Vehicle Recreation Division. “We are trying to move the ball forward in addressing the elevated dust levels on the Nipomo Mesa.”

Allen also outlined the findings of a recently completed study to determine the extent of the dust plume that blows from the off-highway vehicle park into Nipomo and Oceano. During the peak dust months of March through May of last year, the agency deployed 24 portable dust-sampling machines around the South County.

The sampling showed that on high wind days dust often blows as far inland as downtown Santa Maria. Areas of Oceano also receive high levels of dust because to the town's proximity to the Dunes and from vehicles exiting the off-highway vehicle park at Pier Avenue and tracking out dust.

The sampling also showed that dust levels in Oceano are localized with particulates dropping significantly within less than half a mile from the beach. The sampling data will be used to produce more accurate air quality forecasting and public health notification, Allen said.