Even though Maryland has yet to permit any hydraulic fracturing for natural gas, emissions linked to the controversial drilling technique have been detected in the air in Baltimore and Washington, according to a new study.
In a paper published in the journal Atmospheric Environment, University of Maryland scientists reported finding that levels of ethane, a component of natural gas, rose 30 percent from 2010 through 2013 in air samples taken at a monitoring station in Essex.
A similar spike in ethane levels was detected at a monitor in Washington near Howard University - but not in Atlanta, where there is no fracking occurring in neighboring states.
The UM researchers say they couldn't find anything in Maryland that could account for such increases. Indeed, levels of other air pollutants responsible for summertime smog have declined significantly since the 1990s.
But in reviewing air circulation patterns in the Mid-Atlantic region, researchers found that the bulk of prevailing winds reaching Baltimore and Washington passed over areas of Pennsylvania, West Virginia and Ohio where there is widespread drilling for gas.
"What we're trying to do is wave a little flag," said Sheryl H. Ehrman, a co-author of the paper and chair of UM's chemical and biomolecular engineering department. "It looks like we've got a problem. I think we've got a regional issue."
The study, which was underwritten in part by the Maryland Department of the Environment, comes as the Hogan administration mulls adopting regulations to allow hydraulic fracturing, commonly called "fracking," in western Maryland.
Rules proposed under former Gov. Martin O'Malley would mandate control and reporting of air emissions from wells. Hogan administration officials have yet to say whether they will stick with or change such requirements.
The General Assembly this year imposed a moratorium on fracking until October 2017, ostensibly so lawmakers can review whatever regulations are finalized before any drilling can begin.
Environmentalists and some scientists have raised concerns over the health and environmental impacts of air emissions and leaks from gas wells and their related operations. Ethane is a relatively minor ingredient of natural gas, while the main component is methane, a potent greenhouse gas.
But the ethane spike picked up by the UM study is "a canary in the coal mine," said Ehrman. There aren't similar data tracking climate-altering methane and other pollutants produced by gas extraction, she said.
"If we're seeing the ethane what else might we be seeing?" she asked.
A Carnegie Mellon University study projects that gas production from the Marcellus shale formation, which stretches from New York through western Maryland to the Carolinas, could account for as much as 28 percent of the smog-forming air pollution in the region by 2020.
Smog-forming and fine particle emissions from fracking operations could undermine the progress made to date in clearing the air, Ehrman suggested.
Oil and gas industry representatives disputed the study. Joseph P. Massaro, spokesman for Energy in Depth, an arm of the Independent Petroleum Association of America, said the Environmental Protection Agency and others have determined that air emissions have declined in spite of, or because of, growing production of natural gas.
Using gas to produce energy generally produces less climate-altering carbon dioxide and other air pollution than would burning coal or oil. Where experts tend to differ is over the scale and impact of emissions released during "completion" of a gas well, from unintentional leaks and from related operations, such as gas compressor stations and heavy truck traffic.
Dan Whitten, spokesman for the American Natural Gas Alliance, contended methane releases have declined sharply in recent years as the industry increasingly practices "green" well completions, capturing emissions rather than letting them vent into the air.
Ehrman said that "hopefully we will see this downwind." But she noted that the Texas study's projections of growing air pollution have taken into account EPA air quality regulations on the books so far.
"There's still room in there for development of more stringent rules to reduce emissions and increase monitoring at the state level," the UM researcher concluded, "and it's there that regional cooperation would be helpful."