The U.S. Environmental Protection Agency on April 18 finalized standards under the Clean Air Act to reduce air pollution associated with oil and natural gas production through hydraulic fracturing.The national standards are the first effort by EPA to regulate emissions from oil and natural gas production through hydraulic fracturing.

Hydraulic fracturing, or "fracking," is a technique used to release oil and natural gas by pumping large amounts of water, sand and chemicals into the ground where oil and gas are locked in shale or other geological formations. The standards require owners or operators to either “flare” their emissions or use emissions reduction technology called "green completions," technologies that are already widely deployed at wells. Beginning on Jan. 1, 2015, all new fractured wells will be required to use green completions.

The EPA says that these technologies will not only reduce 95% of the harmful emissions of substances like benzene and other volatile organic compounds from fractured wells that contribute to smog and lead to health impacts, they will also enable companies to collect additional natural gas that can be sold.

Gina McCarthy, assistant administrator for EPA's Office of Air and Radiation, told reporters in a conference call that the new standards are "practical, flexible, affordable, and they're achievable." Many well operators are already reducing emissions through green completions or flaring, she said. Some states, such as Colorado and Wyoming, are already regulating oil and gas emissions from fractured wells as well.

The three-year transition period is a concession to industry groups who provided data that the equipment needed for compliance would not be widely available and cost-effective until 2015, she added.

American Petroleum Institute’s director of regulatory and scientific affairs Howard Feldman says he thinks the EPA's final rules are an improvement over the initial proposal. "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 needs," he says.

Environmental groups also praised the rule, saying it was a good first step to regulating an industry that many claim has caused environmental and health hazards. But Miriam Rotkin-Ellman, staff scientist at the Natural Resources Defense Council, says, "The rapid expansion of oil and natural gas drilling without modern air pollution controls has exposed millions of Americans to a toxic brew of cancer-causing, smog-producing, and climate-changing air pollutants…Left to police itself for too long, the oil and gas industry has failed even to adopt pollution controls that pay for themselves."