Issue Clouded : State Considers Off-Road Park Despite Concern Over Asbestos Dust

The state is considering buying a 46,000-acre tract in the western San Joaquin Valley for an off-road vehicle park despite concerns expressed by environmentalists and state and local water agencies that dirt-biking there could raise clouds of asbestos dust and increase erosion of asbestos soil into the California Aqueduct.

The state Off-Highway Motor Vehicle Recreation Commission, which has passed resolutions supporting the park in concept, is scheduled to decide later this week whether to buy and develop the tract at a cost of about $10 million.

At least two parts of the remote parcel are high in naturally occurring asbestos.

The proposed park borders the federally owned 43,000-acre Clear Creek Management Area, where dirt-bikers tear through soil so loaded with asbestos that airborne levels of asbestos exceed federal industrial standards.

Asbestos can cause cancer when inhaled. But there is no conclusive evidence that it can cause cancer when ingested in water.

Still, some fear that erosion caused by dirt bikes could increase asbestos levels in California Aqueduct water, which provides more than 13 million Southern Californians with part of their drinking water.

The property in western Fresno and eastern San Benito counties is “much too sensitive to erosion” for an off-road park, said Howard Wilshire, a research geologist and former member of the off-highway commission.

But officials with the Division of Off-Highway Motor Vehicle Recreation, a branch of the state parks department, contend that the environmental problems can be managed by installing sediment dikes or other erosion controls. And to control asbestos dust, they said, they will route trails away from the areas with high asbestos soils--possibly erecting fences as well.

Critics, however, question the efficacy of such control measures.

The state officials also said they may shelve a plan to build trails connecting Martin Ranch with the Clear Creek area.

“We’ve had a great deal of difficulty finding projects for the off-road vehicle users,” said Ronald Rawlings, assistant chief of the off-highway division. “And this (project) does not appear to have any unrealistic problems.”

But even some of the commission members are asking whether the environmental problems can be overcome, and at a reasonable cost.

“Children are out riding these vehicles,” Commissioner Marge Sutton said. “Should they be riding them over asbestos?”

“I want to hear more about management before I make a decision myself,” Commissioner John Motley said.

The presence of asbestos is not the only potential roadblock. Off-road officials also have acknowledged that such a park could accelerate runoff of selenium, a naturally occurring element that is highly toxic in concentrated amounts.

Park users and staffers also would be at risk of contracting valley fever, a disease endemic to the San Joaquin Valley that is carried by fungus spores in airborne dust, according to a recent environmental impact report prepared by state park officials. The fever commonly produces flu-like symptoms; in rare cases it causes permanent disability or even death.

“I personally cannot see why the state persists in pushing this project in such a very unsuitable location,” said Mark Ward, a nearby property owner. “It just seems dumb.”

The park, which has had enthusiastic support from some off-road groups, would double the acreage of state off-road parks, of which there are six.

Called the Martin Ranch after the family that owns it, the land is in dry hill country six miles west of the California Aqueduct.

Over the years, streams draining the ranch and the Diablo Mountains to the west have deposited huge amounts of asbestos mud along the aqueduct, and rain periodically has flushed sediment into the aqueduct.

Tests have shown up to 25 billion asbestos fibers per liter in aqueduct water near the site, according to the state Department of Water Resources, which owns the aqueduct in partnership with the federal government.

The state agency has spent about $10 million dredging asbestos mud from the aqueduct.

Although there are no standards for asbestos in drinking water, the U.S. Environmental Protection Agency has proposed a precautionary health guideline of 7.1 million asbestos fibers per liter of drinking water, counting only the long fibers, which are thought to be more likely to be hazardous.

The Metropolitan Water District, which supplies aqueduct water to more than 13 million people in Southern California, would easily meet the EPA’s advisory limit, although the treated water sometimes has contained millions of short fibers, which some scientists believe are less hazardous.

Edward Thornhill, chief of environmental planning at MWD, said asbestos now is “not a problem to us.” But he said the district does not want “airborne asbestos from the vehicles and additional erosion getting into the aqueduct.”

Although off-road division officials have said they will control asbestos runoff from the proposed park, critics have said the officials should spell out their plans before acquiring the land.

According to officials of the water resources department, the off-road division may be “underestimating” the measures needed “to ensure that the proposed project will not worsen runoff, sedimentation, and asbestos problems.”

As the vote nears, some off-road officials are saying that chrysotile, the type of asbestos found on the ranch, may be safe, unlike other forms of asbestos.

But while chrysotile “may be a little less hazardous,” according to Dr. Kaye Kilburn, a professor of medicine at USC who has studied disease among asbestos workers, the difference between it and other types of asbestos “is the difference between being run over by a 10-ton truck, or a tank.”