Health & Science

Air Toxics Can Leak Near Gas Wells

Natural gas production is a growing source of air pollution. Near Fort Worth, companies have sunk 14,000 gas wells into the Barnett Shale. But drilling happens regularly in the Houston region too. The state is stepping up regulation — but critics wonder if it’s enough. KUHF health science and technology reporter Carrie Feibel has more.

Yesterday we heard the story of Suzanne Deason, a resident of Summerwood, just west of Lake Houston. Last June a company began drilling a gas well down the street from her house. It was perfectly legal, but it still surprised her. And she was worried, especially about the diesel fumes.

“I think this is one of the reasons I feel so betrayed and I’m so angry that someone has the right to bring that sort of thing into your home, literally. I mean, those fumes come right into my home through my air-conditioning.”

County and state inspectors came out. They did detect diesel emissions, but not above levels considered dangerous to human health. Rock Owens is the chief environmental attorney for Harris County.

“You have to be able to report the nuisance and then get an investigator out there to investigate the nuisance while the condition still exists and that makes it a little tricky.”

The drilling wrapped up in September and the diesel smells went away. But that doesn’t mean the air pollution has stopped. The company is now drawing gas from the well through a system of tanks and pipes. It’s been long known that this equipment for collecting and storing natural gas can constantly leak small but potentially dangerous amounts of toxic chemicals. The carcinogen benzene, for example, is a common stowaway in oil and gas pockets. I asked Anne Inman, a regulator with the Texas Commission on Environmental Quality, to describe the problem.

Fiebel: “And where does benzene potentially leak out in the production process that you’re watching?”
Inman: “Every single point, where there’s petroleum, if there’s any there.”

Fiebel: “So it would be at a joint, at a …”

“At a flange, at a joint, at a valve, at a process vessel, at a tank, out of a truck, out of the gasoline that you’re putting in your car at the gas station. There’s always a little bit everywhere.”

Technically, these leaks can’t exceed certain amounts. The TCEQ does conduct some inspections, but mostly relies on companies to police themselves. Environmentalists say that one big problem is that the agency doesn’t even know where a lot of the equipment is. Ramon Alvarez  is a scientist with the Environmental Defense Fund.

“The state got caught by surprise in a way because once there were 14,000 wells drilled in the Barnett Shale and a lot of concerns were raised about emissions, the agency didn’t even know where — what wells were there, what emissions they were releasing, what equipment they were using at the well, because the companies didn’t even have to register the facility with the Commission.”

This year, the TCEQ did begin building an inventory of equipment in the Barnett Shale region. And it’s proposing new statewide rules to better track pollution from oil and gas production.

Again, Inman: “Our new proposed rule would require everyone, whether they’re natural gas or crude oil, to let the agency know where they are, who they are, what they’re doing and give us an estimate of their emissions.”

Alvarez is happy about that, but says the proposals still don’t go far enough. He says natural gas comes out of the ground under high pressure. And he wants companies to work harder to prevent small bursts of gas from escaping, along with their toxic hitchhikers.

“Just think of the Coke bottle. You know when you open it up: Psssshh. All that stuff just flashes off as it goes to the low pressure condition.”

It’s a little psssh here, a little psssh there. But Alvarez says it adds up.

“The emissions from tanks in Texas alone were bigger than any other source in the state.”

In Colorado and Wyoming, companies must install certain equipment to capture leaking gases. The Texas approach is to let companies pick their own technologies to keep pollution under a certain level. The TCEQ will consider adopting the new rules on Dec. 14. From the KUHF Health Science and Technology Desk, I’m Carrie Feibel.