“We’re pleased to see that elements of the BLM’s proposed regulations on flaring, venting and leak prevention are modeled from Colorado’s rules, and will minimize the waste of natural gas while reducing harmful emissions,” Colorado Gov. John Hickenlooper said, when the BLM first proposed its new rules in January.

But the Western Energy Alliance, a lobbying group representing oil and gas production companies in 13 western states, does not feel the Colorado methane rules have been worth the money spent by industry to implement them.

“We don’t really believe that Colorado’s rule is necessarily a model for the entire country,” said Kathleen Sgamma, WEA’s vice president of government and public affairs. “States are 50 different independent laboratories … and we certainly don’t agree that it’s a cost-effective method.”

By seeking out and minimizing leakage, “these oil and gas control measures are estimated to reduce [volatile organic compound] emissions by approximately 93,500 tons per year and methane/ethane emissions by approximately 65,000 tons per year, at a cost of approximately $42.5 million per year,” according to the state.

The VOCs are critical as the state grapples with tougher new EPA ozone standards. Methane reduction is key to combating global climate change, according to state officials and environmental groups, which also argue that oil and gas companies directly benefit from keeping methane out of the atmosphere and putting it into production.

“It’s the best bargain in air-pollution reduction today,” said former state lawmaker Dan Grossman, the Rocky Mountain regional director of the Environmental Defense Fund. “Unlike putting a scrubber on a power plant, which is only a cost, these measures put more product in the pipeline and offset a lot of the cost burdens on the operators to begin with.”

Sgamma counters that the state’s estimates are just that, estimates, and even those only equate to a very small amount of methane captured and returned to the production loop.

“What the [state] was claiming would be saved from the regulation comes out to less than a day’s worth of Colorado production—one day’s worth out of a year,” Sgamma said. “That’s the high estimate; it’s less than a day of production, and it’s very unlikely that even that estimate would be met.”

Asked to quantify the amount of methane Colorado’s new rules have kept out of the atmosphere through reduced leakage or venting, Will Allison, the director of the Air Pollution Control Division of the Colorado Department of Public Health and Environment, did not offer a set number. But he did say the program is working.

“Colorado inspectors are finding fewer leaks at oil and gas sites since the state adopted its methane rules in early 2014,” Allison said. “Because Colorado companies are required to find and fix leaks, this has led to improved operation and maintenance in the field.”