Oceano Dunes State Vehicular Recreation Area has spent more than $2 million over the past two years on various dust-control measures but still is not meeting requirements to substantially reduce unhealthy amounts of dust blowing onto the Nipomo Mesa.
In spite of extensive use of wind fences and hay bales to control blowing dust, areas downwind of the park still violated state and federal air quality standards during this year’s windy season from March through May.
At an often contentious meeting Wednesday, many members of the San Luis Obispo County Air Pollution Control District Board of Directors said they were frustrated at the slow success rate by the Off-Highway Vehicle Division of the State Parks Department in reducing blowing dust.
Efforts to address the issue began in 2011 and state and local air quality regulators had hoped that substantial progress would have been made by now in reducing the blowing dust. That has not happened.
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“The progress here is glacial,” said Arroyo Grande City Councilman Joe Costello. “Let’s melt the glacier.”
San Luis Obispo Mayor Jan Marx agreed, saying, “If this is an emergency, let’s act like it’s an emergency.”
Air district and State Parks officials had hoped that a combination of hay bales, vegetation replanting and wind fences in the park would reduce blowing dust to meet federal air quality standards. However, monitoring showed there were still two days of bad air between March and May that failed to meet federal air standards downwind of the park — a level similar to the number of unhealthy air days in the past, said Larry Allen, air pollution control officer.
“So it was not possible to determine if the measures put in were effective,” he said. “The actual effect on our monitoring stations which are downwind from the park was not recognizable in the data. Clearly, more needs to be done.”
This spring, three miles of wind fences covering 15 acres and more than 5,000 hay bales on 30 acres were installed in the park to test their effectiveness in reducing dust. Both work by slowing the speed of the wind blowing across the surface of the sand dunes.
Both techniques were effective in some dust reduction, but State Parks is going to need to refine the placement and use of them within the park during next year’s windy season to maximize their effectiveness, said Christopher Conlin, deputy director of the state’s OHV Division.
Although details have not been finalized, the dust-control measures tested this spring will be some combination of hay bales, wind fences and revegetation, parks officials said.
“The goal is to stop the bleeding,” Conlin said. “We are still committed to improving the air quality on the Nipomo Mesa.”
The air district board directed staff to return with another update in June after the results of monitoring during next year’s windy season are available.
The air district adopted a rule in November 2011 that requires the park to reduce the number of days of unhealthy air on the Mesa by about three-quarters. Currently, air quality there exceeds state standards by 65 days or more a year and federal standards two or three days a year.
State dust standards are three times stricter than federal standards. High levels of dust cause a variety of breathing problems including asthma and respiratory infections.
Recent monitoring showed that emissions are 2.5 to 5 times higher from riding areas within the park compared to non-riding areas, said Ronnie Glick, an environmental scientist at the park. This prompted some of the board members to urge State Parks to concentrate their dust-control efforts in the riding areas rather than buffer areas that are closer to monitoring stations.
Not everyone was critical of the progress of the dust measures, however. Pismo Beach Councilman Ed Waage and Grover Beach Mayor Debbie Peterson said finding a solution to the dust problem is complex and will take time.