The Environmental Protection Agency said Wednesday that it will delay requirements for capturing air emissions from oil and gas wells until 2015, though in the interim the agency will impose other requirements, including gas flaring, that it said would reduce the release of smog-forming and toxic chemicals by 90 percent.

The move represents a victory for firms that use hydraulic fracturing to tap natural gas resources trapped in shale rock. The American Petroleum Institute, which has been harshly critical of the Obama administration’s policies, said EPA’s final rules made “constructive changes” from rules the agency proposed earlier.

Half a dozen environmental groups also praised the new regulations, which they said would “result in major reductions” of volatile organic compounds (VOCs), toxic benzene and natural gas, or methane, a potent contributor to climate change.

The issue of whether to regulate drilling emissions has become a political football in an election year and amid the boom in shale gas drilling over the past three years.

President Obama has talked about the need to tap shale gas in an environmentally responsible way. The oil and gas industry has pressed him to open up federal lands for even more drilling and to keep EPA out of fracking regulation. Environmental groups have urged EPA to step in to prevent water pollution and natural gas leaks from pipelines or during drilling that could undermine the climate benefits that gas has over coal.

Under the Clean Air Act, the EPA has the authority to regulate emissions from the drilling activity. But the oil and gas industry has argued that the task should be left in the hands of state regulators.

Assistant EPA administrator Gina McCarthy said Wednesday that “this is a reasonable step for national regulation to try to address.” She estimated that there have been 12,000 gas wells drilled using hydraulic fracturing.

McCarthy said the agency delayed requirements for gas capture because of concerns about the availability and cost of equipment needed and the worker training needed on that equipment. But she said that the gas capture method known as “green completion” is already used for about half the wells drilled and that ultimately companies would save money by capturing compounds that can be sold as fuel and chemical feedstocks.

In the meantime, she said, while flaring is wasteful, it would eliminate 90 percent of volatile organic compounds. Moreover, flaring natural gas, or methane, breaks down the methane into water and carbon dioxide. As a greenhouse gas, methane is more than 20 times more potent than carbon dioxide.

Howard Feldman, director of regulatory and scientific affairs for the American Petroleum Institute, said the changes will “push back” requirements to capture air pollutants at well sites until 2015 but will call for “a whole host of” other requirements, including new valves. The agency will phase in over one year a requirement to put captured gas in storage tanks at well sites, for example.

“On the whole, we believe EPA has made constructive changes in the rule, which will reduce emissions while allowing our member companies to keep producing the oil and gas the country needs,” Feldman said in an interview.

The industry had sought to exempt wells with low emissions from having to capture the volatile organic compounds released during hydraulic fracturing, Feldman said, but EPA refused to do so.

About a month ago, senior oil and gas company executives on the board of API met with Obama senior adviser Valerie Jarrett about the hydraulic fracturing proposal and other energy issues. Feldman would not speculate on whether the meeting helped shape the new requirements, but he said the industry made “cogent and technically-supported arguments for our position” in the course of conversations with White House and EPA officials.

“I hope every place we made those arguments they resonated,” he said.