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Toxic air: Are the emissions from oil and gas wells dangerous to public health?

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CLARK - In February, Deb Thomas received a worried phone call from a neighbor. A funny clanking sound was coming from a natural gas well in their neighborhood, he reported. Could she check it out? 

Thomas, 60, is a longtime activist, having worked for years at the Powder River Basin Resource Council, a landowners group, where she helped push for more stringent regulation of the oil and gas industry.

She grew up a short drive over the Montana border and has longstanding ties to the oilfield. Friends and family have worked in the industry since the 1960s.

Her foray into activism came in 1999 when a natural gas company began drilling near her home. Seven years later one of those wells blew out, prompting the evacuation of 25 families in the area, including her own. 

Thomas left Powder River last year to become the director at Shale Test, which collects environmental data on oil and gas operations, and to consult for the national environmental group Earthworks.

Her goal: study air pollution from oil and gas wells like the one near her home.

As part of that work, Thomas had borrowed an infrared camera. Energy companies use the same device to detect leaks at wellheads, compressor stations and other oilfield sites that are invisible to the naked eye.

And so, when her neighbor called, Thomas departed for the wellpad, camera in tow. She displayed the resulting footage on a laptop positioned on her kitchen table one recent afternoon.

It showed what looked like a dark cloud of steam rising from a compressor shed. The clouds were not steam, however, but gases, some of which can be extremely harmful to human health if the exposure level is high enough.  

"They know this happens everywhere so why don't they fix it?" she asked, with a shake of her head. 

A 2014 study in the journal Environmental Health documented numerous instances at wells in Wyoming and four other states where emissions levels exceeded federal health standards.

One, near Thomas' home, reported benzene levels 12,000 times above the minimum risk level set by the U.S. Agency for Toxic Substances and Disease Registry. Benzene is a known carcinogen.

The report made several notable findings in Wyoming. It documented seven cases where hydrogen sulfide, a potentially lethal pollutant that occurs naturally in some hydrocarbon bearing formations, exceeded safety standards. The study identified four cases of benzene levels above the U.S. Environmental Protection Agency's most hazardous cancer limit, including the one near Thomas' home, which was by far the highest reading. And it recorded one case where formaldehyde levels were above the EPA's most hazardous cancer limit.

Thomas was one of a wider group of volunteers belonging to a group called Global Community Monitor, which helped gather data in accordance to EPA testing protocol. The findings were peer-reviewed and ultimately published in Environmental Health. 

"The landowners we monitored in Wyoming exceeded these standards by enormous amounts, and no one is doing anything about it," said David Carpenter, director of the School of Public Health and Environment at the State University of New York Albany and lead author of the report. "In my judgement, in the long term, the (pollutants) that are really frightening are these ones causing cancer."

The problem, he added, is that it generally takes years for the first patients to show cancerous symptoms. 


It is unclear if the report's findings represent an isolated incident or are part of a wider trend. State and federal regulators do not monitor hazardous air pollutants like hydrogen sulfide and benzene from oil and gas operations. 

The reason: Oil and gas production is exempted from the regulations governing hazardous pollutants under the Clean Air Act. 

Industry representatives have dismissed the Environmental Health study, calling it biased.

"It's difficult to see how Global Community Monitor, a group that dubiously claims no amount of regulation will ever make fracking safe, could make a constructive contribution within the scientific community," Katie Brown, a spokeswoman for the Independent Petroleum Association of America's Energy in Depth campaign, told the Center for Public Integrity in November. 

The study is nonetheless one in a growing number of reports linking emissions from oil and gas operations to health problems.  

An April 2014 study by the Colorado School for Public Health found higher rates of congenital heart defects in infants born within 10 miles of areas with a higher density of natural gas wells. 

Researchers in Pennsylvania reported in 2013 that residents living within two-thirds of a mile of a drilling rig were more likely to report rashes and respiratory problems than their neighbors living further away.

A third study, conducted by researchers at the University of Wyoming, did not examine health impacts, but found elevated levels of benzene and pollutants known to form ozone under the right conditions at water treatment facilities in the Upper Green River Basin.

"We found levels that are high compared to busy city locations," Robert Field, a professor of atmospheric science and the report's lead author, wrote in an email to the Star-Tribune. "Such occurrences inside the boundary of the oil and gas development areas were common and reflective of the meteorological conditions."

The Upper Green River Basin was named a nonattainment area by the EPA in 2011 for exceeding the federal health standard for ozone. Smog, as ozone is commonly referred to, has been linked to health ailments like asthma, stroke and heart attacks, according to the American Lung Association.  


Concern over air quality comes at a time when oil and gas development is occurring in growing proximity to communities. Development in Wyoming traditionally took place in remote sections of the Big Horn, Green River and Power River basins.

But the most recent round of drilling pushed up against the city limits of Cheyenne and Douglas. 

Wyoming, like most states, seeks to regulate oilfield emissions at the time a well is drilled or repaired. 

The assumption is that pollution controls will be required as part of the initial permit. Further controls can be added when a well is modified and its permit is updated.

The problem, environmentalists said, is many wells are drilled and then left for years.

"We do know in five, 10, 15 years, as the infrastructure starts to fall apart, we're going to have huge issues with contamination," Thomas said. "You're continually playing catch-up, particularly in states that rely on extractive industries."

The lack of upgrades speak to a need to update the state's air quality rules to cover existing wells, as well as new and modified ones, they said.  

Wyoming is considering just that, though the rules will apply only to the Upper Green River Basin. The proposal, expected to be finalized this year, would require companies in the region to conduct leak detection and repair programs for facilities emitting more than 4 tons of volatile organic compounds annually. 

It is intended to cut down on ozone pollution and help bring the area back into compliance with federal health standards. But keeping the pollutants that can form ozone in the pipe also prevents carcinogens like benzene from leaking into the atmosphere, said Jon Goldstein, a policy adviser at the Environmental Defense Fund. 

Expanding the existing source rules proposed in the Upper Green River Basin to cover the entire state would help combat the problem, he said. 

"While it’s important to pass rules for new and modified sources, you need to pass rules for existing sources as well," he said.

Steve Dietrich, director of the Department of Environmental Quality's air quality division, dismissed that suggestion. The Upper Green River Basin is out of compliance with federal ozone standards, necessitating the additional layer of regulation. Other parts of the state are in compliance, making the adoption of the existing source rule in other areas impractical, he said.  

Addressing air quality concerns through permitting is a quicker way to solve that problem than rule-making, a long and often contentious process, Dietrich said. 

The state's air quality permits require new and modified facilities capture 98 percent of all emissions. 

He said he could not comment on the Environmental Health study. DEQ must act within the law and can respond only if current standards have been violated. Establishing new standards is a task that belongs to the EPA, Dietrich said.  


Several times a week, when the wind blows from the east, the smell of rotten eggs wafts over Geanie and Doug McMullan's 300-acre goat farm near Deaver.

It is an ominous sign, and not just because the smell is rancid. The odor is a sign of hydrogen sulfide. 

The hydrogen sulfide at the McMullan's is the product of two aging oil wells about a half-mile from their home. The wells are old. Each was drilled in 1970 and produced water flows into three open-air impoundments, where hydrocarbons and water are separated, before eventually being discharged into an irrigation ditch.

The wells have proven a consistent scourge for the McMullans over the years.

The couple tries to keep their goats away from the wellpads, but the conniving creatures are always finding ways to slip the fence. They try to keep the dogs away from the irrigation ditches. Inevitably the dogs find their way into the ditches.

Geanie suffers from regular nose bleeds. It could be from the dry air, but she suspects it's because of the wells.

"We’ve had the state out here so many times," Geanie said. "DEQ, EPA, the guys from Denver. They all stand around. Nothing is done."

The Environmental Health study found hydrogen sulfide exceeded the U.S. Agency for Toxic Substances and Disease Registry's acute and intermediate minimal risk levels.


The two wells are owned by Rael Resources LLC, a small company based in Cowley. Rael owns four wells total and, in 2014, reported combined production of 7,125 barrels of oil and 637,000 barrels of water, according to Oil and Gas Conservation Commission statistics. 

It is a family owned company, and the fifth to operate the wells near the McMullan's. 

David Rael, the owner, was herding cattle when reached by cellphone in early May. 

"We’ve done everything we possibly could," he said, as his animals bayed in the background. "We comply with everything we’re supposed to." 

The Oil and Gas Conservation Commission generally leaves air quality matters to its counterparts at the DEQ. But hydrogen sulfide is so serious that the commission has its own regulations to govern the gas, said Tom Kropatsch, deputy supervisor.

The rules require companies install blowout preventers at wells where hydrogen sulfide is present. Venting, the controlled release of gases, is prohibited at quantities greater than 50 parts per million.  

However, the regulations do not cover fugitive emissions, the industry term for the pollutants that leak out of tanks, pumps and pipes. 

Several years ago, the McMullans complained about the hydrogen sulfide coming from the wellpads. The commission and DEQ investigated, but did not find dangerously high levels from either the tanks or the pits at the site, Kropatsch said. 

Hydrogen sulfide complaints are generally rare and limited to fields where the pollutant is found in the geologic formation, he noted. To his knowledge, Kropatch said, it has not been found in new fields around Cheyenne or in the Powder River Basin. 

Six of the seven cases of elevated hydrogen sulfide concentrations identified by Environmental Health were in Park County. The remaining case was in Fremont County near Pavillion. 


Deb Thomas and her husband, Dick Bilodeau, live in a blue trailer tucked along a creek leading into the Beartooth Mountains. Tires line the roof and cables run from the building's corners to sunken wooden anchors in the ground, serving as protection against wind gusts that can sometime reach up to 100 mph. 

The couple once had plans to build a permanent home on their property. But then the well blew out and they spent the next decade debating whether to build or move. 

Thomas has had a series of rashes and urinary tract infections in the years since. Soon after the blowout she was rushed to the emergency room with respiratory problems. Her friendships have suffered. Where Thomas once volunteered in the local school, she is now a controversial figure in Clark because of her outspoken opposition to oil and gas development. 

"People here either love me or hate me," she remarked. 

For now, the family will stay, despite ongoing remediation from the well blowout and their concern over the dangerous emissions near their home. At 60 years old, Thomas doesn't feel up for a move. But she also feels like that would be giving in to the oil and gas companies. So she plans to stay and fight.

Follow energy reporter Benjamin Storrow on Twitter @bstorrow.


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