Maryland regulators are weighing some of the strictest limits in the country on shale gas drilling, but a scientist Monday suggested they still may not go far enough to protect drinking water wells from contamination by methane leaking from drilling sites.
Gas drilling rigs would generally have to be at least 2,000 feet from public or private water wells under rules being considered by the Maryland Department of the Environment, officials said Monday during a meeting of the governor's advisory commission on the issue.
But Avner Vengosh, a researcher at Duke University, told commission members that studies he and his colleagues have done in states bordering Maryland and elsewhere found that domestic water wells were more likely to be fouled with potentially explosive levels of methane gas if they were within one kilometer — 3,280 feet — of a drilling rig. Water wells farther away rarely had problems, he said.
"If I were in your position, I would try to be as cautious as possible," Vengosh said.
The debate over well protections came as the advisory commission nears the end of a three-year study of the promise and potential problems associated with drilling for natural gas in shale formations beneath western Maryland. While thousands of shale gas wells have been drilled in neighboring Pennsylvania alone, supporting tens of thousands of jobs, the O'Malley administration has put drilling on hold until it can determine whether it can be done safely, citing concerns about environmental and health impacts. The 15-member panel is expected to issue a draft final report by the end of June.
Administration officials defended the setback under consideration, saying it was drawn primarily to protect drinking-water wells from chemical spills or leaks from a drilling site. Ground water generally flows so slowly that there would be plenty of time to detect any contaminants before they could reach a drinking-water well.
"What we're calling for is the tightest in the nation," said Christine Conn, a manager in the Department of Natural Resources' aquatic resources division.
Drew Cobbs, executive director of the Maryland Petroleum Council, concurred, saying that the state is leaning toward requiring more planning, testing and safeguards than any other state has so far. He said they'd make it both more time-consuming and expensive to get approval to drill, and depending on gas prices and what other states require the industry may choose to bypass Maryland as a result.
"Only time will tell whether the industry will be interested in developing here," he said.
Gas industry executives have challenged the Duke research, arguing that methane occurs naturally in ground water in the mid-Atlantic region underlain by Marcellus shale. Conn said state officials don't doubt the Duke research, but are looking to prevent methane leaks in other ways, by limiting where wells can be drilled and by requiring they be properly sealed. She said the state also is considering barring drilling within 450 feet of a stream or other water ways, expanding the buffer now required.
The setback under consideration from residential wells would be roughly double what's required under the state's current gas drilling regulations, officials said. Exceptions could be allowed to drill as close as 1,000 feet, they noted, if the gas company could show that ground water at the drill site flows away from any homes in the vicinity.
Activists joined the Duke researcher in arguing for a larger setback.
"The state is making a huge mistake," said Paul Roberts, co-owner of a Garrett County vineyard near a site that's been leased for drilling. "It's not protective in any way."