The Obama administration has ordered natural gas developers to address the air pollution that's created when a gas well is hydraulically fractured.
The rule only applies to wells drilled into deep shale gas formations, like the Marcellus Shale beneath Pennsylvania.
Some of the rules will be enforced immediately; other provisions will be phased in over time. All gas wells fractured after 2014 will have to be fitted with equipment that captures all "flowback" in a way that prevents any of it from escaping into the atmosphere. The EPA says flowback emits volatile organic compounds (VOCs) that create smog, as well as carcinogens like benzene and hexane.
Until the first day of 2015, energy companies can curb gas well pollution either by using such "green completion" technology, or by burning off the flowback gas as it emerges from the well. Once 2015 arrives, all new fractured wells must use green completions.
EPA administrator Gina McCarthy said green completions are the preferred method of pollution control because they allow energy companies to sell off the gas that otherwise would have escaped into the atmosphere.
"And it also provides an opportunity for the public to know that precious natural resources are not being wasted," said McCarthy. "That's why Wyoming and Colorado have already taken the step to regulate this. Other cities and counties have as well. This is a reasonable step for national regulation to try to address."
The EPA estimated the new rules will cut the shale gas industry's VOC emissions by almost 95%. The agency said by 2015 energy companies will also cover their costs and even save $11 million to $19 million per year by selling flowback gas.
McCarthy said the EPA standards also address pollution from other natural gas infrastructure, "including the gathering and boosting stations that move gas from several wells along the pipeline for processing; compressor stations that keep gas moving; and natural gas processing plants."
The new rule was hailed by the natural gas industry.
"EPA has made some improvements in the rules that allow our companies to continue reducing emissions while producing the oil and natural gas our country need," wrote Howard Feldman, Director of Regulatory and Scientific Affairs at the American Petroleum Institute.
The Natural Resources Defense Council also praised the EPA regulations as a step toward protecting public health.
"But to fulfill President Obama's State of the Union pledge to develop these resources 'without putting the health and safety of our citizens at risk,' the EPA needs to do more to protect people living near oil and gas production facilities," wrote Meleah Geertsma, an NRDC attorney.
The EPA estimated that about 13,000 natural gas wells are fractured or re-fractured in the United States each year.