Marin IJ
October 27, 2009

Supervisors approve quarry's environmental impact report
By Richard Halstead

Medical experts disagreed over the health effects of continued mining at the San Rafael Rock Quarry during a key public hearing on the quarry Tuesday.

More than 300 people attended the three-hour hearing at the Civic Center, where county supervisors voted unanimously to certify as adequate and complete an environmental impact report submitted by the Dutra Group to continue operations at the quarry for least another 17 years.

The Dutra Group wants to dig the pit twice as deep as the 200 feet below sea level allowed by a 1982 permit, and continue operations for another 17 years with 250 truck trips daily.

The next and final step in approving a new use permit for the quarry is for supervisors to conduct a hearing on the merits of the Dutra dustup Is the San Rafael quarry a threat to public health? Yes No quarry's plan. Prior to that hearing, which has not yet been scheduled, supervisors Susan Adams and Steve Kinsey will work with the county's Department of Public Works to formulate the conditions that Dutra will be required to meet.

The impact report also covered Dutra's reclamation plan, which includes a plan to carve a channel between the main pit and San Pablo Bay and flood the massive bowl. Dutra have proposed using a mechanical device, as yet unspecified, to prevent the water in the bowl from stagnating due to a lack of circulation.

As during previous hearings on the impact report, most of the discussion Tuesday focused on the health risk to people living near the quarry from the crystalline silica dust produced by the quarry and the diesel emissions of trucks and equipment used in mining operations.

Paul Damian, a toxicologist with SCS Engineers in Sacramento, said even though crystalline silica is a known carcinogen, "no health risk assessment done to date for this quarry evaluates the cancer risk of c-silica."

The problem is that neither the federal nor state government has developed risk factors for c-silica, said Damian, who spoke on behalf of the Point San Pedro Road Coalition, a group of quarry neighbors.

"It doesn't mean it is not carcinogenic or there are no cancer risks," Damian said. "It just means the agency hasn't developed the key information necessary to do that."

Damian said the fact that people living near the quarry are also being exposed to increased diesel emissions because of quarry operations, and have been for years, heightens the risk of lung cancer.

Damian said the analysis contained in the impact report, as well as a separate study commissioned by the Dutra Group, only looked at long-term exposure to c-silica in the area. Damian said that, while those numbers appear low, short-term exposures may be much higher, particularly when blasting is taking place at the quarry.

For example, Damian said he used data collected by quarry proponents to estimate that students at San Pedro School, about two miles away, would be exposed to twice the occupational exposure limit for c-silica for 30 days each year.

Two experts hired by the Dutra Group challenged Damian's conclusions.

Shari Libicki, a principal with Environ International Corp., which the Dutra Group hired to do its own analysis of the quarry's effect on air quality, said Damian used incorrect modeling and ignored the results of air samples taken near the quarry.

Libicki said those samples refute the claims of neighbors who say there is an unusual amount of c-silica dust escaping from the quarry onto their property.

"It's all anecdotal assertions that are simply not true," Libicki said.

Dr. David Weill, director of Stanford University's adult cystic fibrosis center and heart-lung transplant program, said c-silica has been found to cause cancer only in people who work around it and are exposed to exceptionally high levels.

But the medical debate didn't end there.

Dr. Robert Rodvien, an oncologist and hematologist, who serves as a medical director at California Pacific Medical Center in San Francisco, said the impact report fails to take into consideration the fact that many of the people living near the quarry might already have health problems that will be aggravated by the dust and place them at heightened risk for cancer.

Rodvien is one of three physicians living near the quarry who sent a letter to other Marin doctors and medical professionals asking for their help in requiring the quarry's owners to reduce or eliminate the distribution of crystalline silica.

Referring to the disagreement among the medical experts, Rodvien said, "You can read the (medical) literature any way you want. It's a debating society."

Adams said conditions the quarry will have to meet are likely to include close monitoring of the quarry's operations and "along with this there needs to be strict enforcement, meaningful fines, penalties and sanctions, including the possibility of shutting down operations if violations occur."