State Parks has been trying to reduce Oceano Dunes dust for 5 years. Is it working?
For almost five years, California State Parks has worked to reduce the amount of dust pollution blowing from the Oceano Dunes into nearby communities.
Those efforts appear to be paying off — but scientists studying the dunes need more time to confirm that the data is accurate.
A court order directed California State Parks to reduce dust emissions at the Oceano Dunes State Vehicular Recreation Area to a level lower than before people started driving on the dunes, according to San Luis Obispo County Air Pollution Control Officer Gary Willey.
The park is on track to meet that goal, he said.
In 1939, before off-roading was popular, the dunes emitted on average 166 metric tons of dust per day, according to modeling completed by the Scientific Advisory Group that studies the area.
With the current balance of off-road driving and vegetation anchoring sand to the dunes, the park will emit about 148 metric tons of dust per year during average wind conditions — which would meet the goal set in the court order, Willey said.
Wind speeds and the amount of vegetation on the dunes impact how much dust scatters into the air, which means that number could change, he said.
The Scientific Advisory Group needs time to collect more data and confirm that the emissions will continue to stay low.
“We just want to ensure that things are stabilizing,” Scientific Advisory Group chair Bernard Bauer told The Tribune on Wednesday. “You’re dealing with nature — nature adjusts in interesting and delightful ways, so you need to give it a little time to make sure you’re on the right track.”
The San Luis Obispo County Air Pollution Control District hearing board oversees the court order, and its members voted unanimously on Tuesday to extend the court order to Dec. 1, 2028.
This means the hearing board will continue to monitor dust mitigation efforts at the dunes, while California State Parks and its Recreation Off-Highway Motor Vehicle Recreation Division must prepare annual reports and work plans in 2025, 2026 and 2027.
“We’re in good shape right now,” Willey said. “We just have to prove that it’s going that way — it’s going to zero, and that our modeling inputs are sustainable and repeatable.”
Reducing dust emissions at the Oceano Dunes
Over the years, driving on the dunes killed vegetation that anchored sand to the ground, which scattered dust into the air and worsened air quality downwind.
About 740 acres of the park banned off-roading, according to the staff report. Straw and vegetation secured sand to the dunes in many of those areas, while others spots were nesting habitat for snowy plovers.
As the vegetation grows and anchors more sand to the dunes, the air quality should improve, Willey said.
“The air quality will continue to get better as the actual changes to the dunes occur with vegetation,” he told The Tribune on Wednesday.
In 2028, the hearing board will review the park’s dust emissions and decide whether or not to remove the court order.
When the order is lifted, State Parks will likely form an agreement with the Air Pollution Control District about how to keep the reduction in emissions steady, Willey said. This will likely include continuing to plant native vegetation at the dunes.
“We’ve seen really good success,” Willey said. “I expect more reductions at the monitoring sites where people breathe and live as these things mature.”
