Drillers often flare excess gas, which releases harmful air pollutants, include volatile organic compounds. Photo courtesy U.S. EPA
Drillers often flare excess gas, which releases harmful air pollutants, include volatile organic compounds. Photo courtesy U.S. EPA

As fracking starts up in North Carolina, there are loopholes that would allow for air pollution near fracking sites. The second of two stories exploring air pollution rules and loopholes as the process begins.

By Gabe Rivin

North Carolina’s future gas drillers could benefit from several exemptions in federal air pollution rules, leaving nearby residents to breathe potentially large amounts of hazardous air pollution.

Those federal rules, despite their strict limits for most drillers, are lenient for smaller-scale polluters, those whose storage tanks release less than six tons of volatile organic compounds per year. The rules also provide exemptions for exploratory drillers, who, unlike most drillers, will not have to capture pollution at their wells.

Gas drilling is a source of harmful air pollution. The pollutants include benzene, a known carcinogen, and other compounds that cause respiratory problems. Drilling has been linked to infants’ health defects, and researchers have shown that it can cause significant increases in smog.

North Carolina regulators are addressing this pollution by relying solely on federal rules for gas drilling, rather than developing state-specific rules.

Those rules, written by the U.S. Environmental Protection Agency, seek dramatic reductions in volatile organic compounds and other pollutants.

But environmentalists and regulators have questioned whether the EPA’s rules will be too lenient on small-scale and exploratory drillers.

And they worry more broadly that the federal rules will simply not be enough.

What’s the harm in six tons per year?

Environmentalists say they’re concerned about air pollution caused by the storage tanks at drilling sites. These tanks temporarily hold the liquids produced during gas drilling.

But the tanks can leak air pollution. Their vents allow volatile organic compounds, like benzene, to escape into the air and potentially harm nearby residents.

Storage tanks used to hold drilling fluids. Tanks leak volatile organic compounds, which is a concern for nearby residents. Photo courtesy: U.S. Bureau of Indian Affairs

EPA’s rules set firm standards for the tanks. Under the rules, drillers have to reduce 95 percent of their emitted volatile organic compounds.

But that requirement only applies to tanks that emit more than six tons of VOCs per year. A tank that emits 5.9 tons of VOCs would not be required to meet the strict standards.

“That’s one of the really big concerns with the hazardous air pollutants rules,” said Miriam Rotkin-Ellman, a public-health scientist with the Natural Resources Defense Council.

Rotkin-Ellman said the EPA is lacking in its study of this issue. The agency didn’t study, for example, the health effects of breathing 5.9 tons of annual VOC emissions at 650 feet away from a well, the current minimum distance between homes and gas wells in North Carolina.

Other studies have shown that these 650-foot distances can be concerning, Rotkin-Ellman said. In other states, hazardous air pollution has been found at alarming levels, she said.

Exemptions from green completions

Environmentalists and regulators also say they’re concerned about the centerpiece of the EPA’s rules, the requirement that drillers use so-called green completions. This technology works by capturing gas that drillers either would have released into the air or burned off. Both processes can release harmful air pollutants.

Those pollutants include a suite of VOCs such as benzene, which is known to cause leukemia, according to the EPA. The gas can also include toluene, which, through inhalation, can cause central nervous system problems and cerebral atrophy.

VOCs also contribute to the formation of ground-level ozone, which can cause respiratory problems for children and the elderly. Ozone also increases smog’s formation.

The EPA rules require that by 2015 drillers capture this pollution with green completions.

But they also offer an exclusion for “wildcat” drillers. Instead of being required to use green completions, wildcatters will be allowed to burn, or flare, their excess gas.

Drillers often flare excess gas, which releases harmful air pollutants, include volatile organic compounds. Photo courtesy U.S. EPA

So who would qualify as a wildcatter?

The EPA says a wildcat well is one that is “outside known fields or the first well drilled in an oil or gas field where no other oil and gas production exists.”

But that definition raises a question: With North Carolina’s gas fields completely unproven, won’t every new driller qualify as a wildcat?

It depends whom you ask.

One environmentalist said that only a minority of drillers qualify as wildcatters, and that in North Carolina most drillers would be covered by the EPA’s rules.

“As soon as there is any meaningful production, which may be realistically expected, natural gas would need to be captured and routed to pipelines,” said Vignesh Gowrishankar, a staff scientist with the Natural Resources Defense Council.

The state’s chief of air quality, whose recommendation shaped regulators’ decision to only adopt the EPA rules, echoed those claims.

“That first well in an oil or gas field where no other oil and gas production exists could be defined as a wildcat,” said Mike Abraczinskas, deputy director of the Department of Environment and Natural Resources’ Division of Air Quality.

According to that reading of the term, a very small number of drillers would be classified as wildcats, and thus exempt from the green-completion requirement.

But others have raised concerns that the definition of “wildcat” is more nuanced.

“That could be the first well drilled in North Carolina but none of the others,” said Grady McCallie, policy director with the N.C. Conservation Network. But, he said, “it could be a range of interpretations.”

McCallie said that there’s an ambiguity in the term “gas field,” at least when applied to the sort of unconventional drilling that will likely take place in North Carolina.

Gas drillers will likely use hydraulic fracturing, or “fracking,” in horizontally drilled wells. This technique allows drillers to access pockets of gas from dense shale, a process that is uneconomical with conventional, vertical drilling.

But accessing pockets of gas – rather than a large, continuous reservoir – raises questions about where a gas field begins and ends, and what will be, in EPA’s definition, “the first well drilled in an oil or gas field.”

An illustration of horizontal drilling, using hydraulic fracturing. The process recovers gas from hard-to-reach pockets within dense shale. Graphic courtesy U.S. EPA

“It’s one thing to describe a field for conventional oil or gas, where the rock is porous and it’s moving through it,” McCallie said. “I think that’s much less clear for unconventional, where the stuff is trapped in shale and that’s why they’re fracking.”

He also raised concerns about “delineation wells,” which are drilled in order to explore the boundaries of a gas field. Like wildcat wells, these wells can flare their air pollution.

“As long as you keep moving away from the center, I don’t see why it wouldn’t be considered a delineation well,” he said.

Regulators’ concerns

“Up until about a month ago, I felt more comfortable that those 2012 EPA rules were going to have a big impact in North Carolina,” said Amy Pickle, a member of the Mining and Energy Commission.

Since September of 2012, Pickle’s commission has been responsible for drafting almost every drilling rule that the state still will adopt. Under state law though, drilling’s air pollution rules are the responsibility of the Environmental Management Commission, which decided to rely solely on the EPA rules.

“I don’t know if we can say that at the MEC we know enough whether federal or state laws will be sufficient,” she said. “A number of us have some real concerns about the industry.”

Still, Jim Womack, the MEC’s chairman, applauded state efforts to measure air quality near potential wells.

The state has installed air-quality monitors in Lee County, Durham County and Chatham County, where drillers could begin producing gas as soon as next spring. The state has already begun taking samples of the air so that it can compare air quality before and after drilling begins.

“We’ll be able to use that data to identify the before-and-after effects of literally hundreds of potential [chemicals] that would be in the air – everything from nitrous oxide to sulfur dioxide to aromatics, the things that would be considered air toxics,” Womack said.

He said that no other state is gathering this sort of baseline data.

Unregulated pollution

Even with what they say are laudable provisions in the EPA’s rules, environmentalists remain concerned about the potential air pollution from drilling.

The EPA rules “were rightly focused on trying to reduce the emission of VOCs and air toxics at certain points in the oil-and-gas production process,” said David Kelly, a senior analyst at the Environmental Defense Fund.

But Kelly said the rules are limited.

“They’re mostly focused on the well pad, and that ignores a lot of the transportation and processing infrastructure,” he said.

This includes the large number of diesel trucks that travel to and from gas wells, carrying the millions of gallons of water used to fracture wells.

Kelly noted that the EPA is considering changes to its storage-tank rules.

“Right out of gate, that’s a signal that the [EPA rule] isn’t comprehensive,” he said. “While it’s a big, positive step in the right direction, it doesn’t get us everything, and it would be a mistake, in our view, to have a false sense of security that the EPA has it handled.”


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Gabe Rivin

Gabe is our former environmental health reporter from 2014-2016. He is a former editor of The Cooperative Business Journal, and a former reporter for Inside Washington Publishers, where he covered federal...