Dust-up in Grover Beach

Though researchers, officials and a judge have pointed to off-road vehicles as a major contributor to the area’s air-quality problems, the mayor of Grover Beach doesn’t buy it, saying the off-roaders are a scapegoat. “I won’t stay quiet,” Peterson said. “I can’t.”   (Brian van der Brug / Los Angeles Times)

View of the Oceano Dunes State Vehicular Recreation Area. Nearly 2 million people visit the region’s dunes each year, and the whole enterprise represents $171 million in annual economic impact.  (Al Seib / Los Angeles Times)

An all-terrain-vehicle rider takes to the sand of Oceano Dunes State Vehicular Recreation Area, which bills itself as the only state beach where vehicles can be driven on the sand. Some area residents blame respiratory problems on activity by off-roaders in the state park that causes fine dust to blow over from the Oceano Dunes. State park officials say there’s no evidence the ATVs are to blame and call the blowing dust a natural phenomenon.  (Al Seib / Los Angeles Times)

Ronnie Glick, senior environmental scientist with Oceano Dunes State Vehicular Recreation Area, shows the fine powdery talc-like material that covers fences and most other objects surrounding temporary air quality monitoring stations, which where rolled onto the sand and then had to be elevated because the sand beneath blew away.   (Al Seib / Los Angeles Times)

The Guadalupe-Nipomo Dunes are best known for one thing: People have been driving on them “since the creation of vehicles,” according to a state parks district specialist.  (Brian van der Brug / Los Angeles Times)

A thin line of eucalyptus trees stands between a dirt road and homes on the perimeter of a Nipomo development. Grover Beach Mayor Debbie Peterson feels the developer felled too many of the trees, which were supposed to be a buffer against the wind and dust.  (Brian van der Brug / Los Angeles Times)

Many trees in a eucalyptus grove are being cleared for new homes at Monarch Dunes in Nipomo. Grover Beach Mayor Debbie Peterson believes such development is more to blame for particulate pollution in the region than is ATV activity on the dunes.  (Brian van der Brug / Los Angeles Times)

Grover Beach Mayor Debbie Peterson feels that unpaved roads like this one in south San Luis Obispo County contribute to airborne particulate pollution and that vehicles on the Oceano Dunes are not the only culprit behind the dust that sometimes exceeds state air-quality standards.  (Brian van der Brug / Los Angeles Times)

Remnants of clamshells left over from a Chumash settlement form a white pile at Oceano Dunes.  (Brian van der Brug / Los Angeles Times)

Farmland planted with strawberries is near Monarch Dunes homes in Nipomo. Many people believe farm operations contribute particulate pollution in the area.   (Brian van der Brug / Los Angeles Times)

The state parks department has installed a barrier to help keep blowing sand off of homeowners’ property at Oceano Dunes State Vehicular Recreation Area near Grover Beach, where wind and sand make for a troublesome combination.   (Brian van der Brug / Los Angeles Times)