A California environmental advocacy group claims to have detected hydrogen sulfide, a highly toxic chemical, at abnormally high levels in the air above Silt Mesa.

The report comes from Global Community Monitor (GCM), which over the past 15 years has trained volunteers around the U.S. and in other countries on how to form local “Bucket Brigade” air-quality monitoring squads.

The report, “Gassed! Citizen Investigation of Toxic Air Pollution from Natural Gas Development,” was issued Tuesday. It reports on air sampling results, environmental and public health issues in New Mexico and Colorado.

The report states that analysis of Bucket Brigade samples, taken by volunteers in western Colorado and northern New Mexico, detected “a total of 22 toxic chemicals in the air samples, including four known carcinogens, as well as toxins known to damage the nervous system and respiratory irritants.”

Most of the findings deal with eight samples taken in the San Juan Basin, a geologic region around Durango that reaches into New Mexico.

But one sample was taken on Jan. 15, 2011, at the home of the Strudley family on Silt Mesa, which was close to an Antero Resources gas drilling rig.

The Bucket sample collected at the Strudleys, according to GCM, showed hydrogen sulfide at 185 times the level set by the Environmental Protection Agency for long-term serious health risks. It was analyzed by a lab in California.

Jim Rada, Garfield County environmental health manager, said Wednesday that he is not confident in the validity of the report.

“I think the report warrants further explanation from the authors,” he said. “The information is incomplete.”

Emails to an Antero spokesman seeking comment for this story were not answered.

Rada said the reports he has gotten from oil and gas companies has indicated that there is no hydrogen sulfide in the gas deposits being drilled in this area.

Plus, he said, the report gives “no indication … as to where the samples were taken. All you're given is an address.”

He said heightened levels of hydrogen sulfide can some from water wells with sulfur-destroying bacteria, septic tanks and animal feeding operations, “all of which are present on Silt Mesa. It's hard to say that this is related to oil and gas development.”

Sample taken after wells ‘closed in'

The air sample was taken a month after Beth Strudley reported that she was detecting the smell of rotten eggs in the family's home, a smell that is characteristic of hydrogen sulfide.

The family later reported the appearance of painful and unsightly skin rashes, bloody noses and other symptoms they argued were linked to odors and to air or water contamination from nearby gas wells. They moved out of their home a few weeks later.

Industry representatives at the time downplayed the fears of the Strudleys and others who believe that the procedure known as hydraulic fracturing, or “fracking,” poses hazards to water quality in Garfield County.

The procedure involves injecting massive amounts of water, small solid particles and chemicals into a well bore after it is drilled, to break up the deep rock formations where natural gas deposits are trapped and permit the gas to flow to the surface.

According to the industry, there has never been a conclusive finding that fracking poses health hazards in areas where drilling activities are conducted.

Rada also said that he was informed that all of the gas wells on Silt Mesa were “closed in,” meaning drilling and fracking activities had been completed prior to the sample being taken on Jan. 15, 2011.

“If they were closed in, I can't imagine they were emitting anything,” he said.

Findings ‘deserve consideration'

David Ludlam, executive director of the West Slope Colorado Oil and Gas Association, questioned whether the Bucket Brigade air samples are reliable.

“Their concerns are real, their intentions are good, but their science is not,” Ludlam remarked. “Vigilante air studies are ill advised.”

Hydrogen sulfide can come from many sources, he said. Ludlam said it is not present at the levels proclaimed in the GCM report in the natural gas pipelines themselves, nor does it occur naturally in the Piceance Basin.

He said the industry would support air quality studies “in a manner where the companies have input into the quality assurance program,” and that could be reviewed by others in the scientific community.

Frank Smith, organizing director for Western Colorado Congress, a citizens group, said he thinks the findings deserve serious consideration, even if they are not in a traditional scientific study.

“I think it is as close as citizens can get, with the limited tools they have available to them,” Smith said. “As we're waiting for our governments to allocate funds [to conduct more complete studies], at least citizens can do something.”

He said the Colorado Department of Public Health and Environment and the Garfield County Public Health Department should both should be conducting extensive studies to ensure that gas drilling does not harm the public, rather than relying on the public to do its own testing.

The Strudley family could not be reached for comment on the air sampling findings.

jcolson@postindependent.com