Three days after two industry groups had done the same, Montana and Wyoming filed a separate lawsuit last week against the Interior Department (DOI) over a final rule to reduce venting and flaring from oil and gas operations on public and tribal lands.

In a petition for review of final agency action filed in U.S. District Court in Wyoming last Friday, the states derided the methane rules promulgated by the DOI and its Bureau of Land Management (BLM) as a “blatant attempt by a land management agency to impose air quality regulations on existing oil and gas operations under the guise of waste prevention. Congress specifically delegated authority to regulate air pollution to the U.S. Environmental Protection Agency [EPA] and the states because they are in the best position to regulate air quality matters.”

Montana and Wyoming added that the rule — officially, the Methane and Waste Prevention Rule — conflicts with the federal Clean Air Act and should be deemed illegal because it also interferes with the states’ air quality regulations. “The BLM does not have the authority, much less the agency expertise, to impose air quality control requirements promulgated in the final rule,” the states said.

Wyoming Gov. Matt Mead blasted the rule in a separate statement Monday.

“The BLM is once again overstepping its bounds and imposing unnecessary regulations,” said Mead, a Republican. “Congress has delegated regulation of air pollution to the states and EPA, not BLM. Wyoming has successfully regulated air pollution emissions from oil and gas activities for over 20 years and has effective limitations on venting and flaring of natural gas.

“Wyoming has been a leader in air quality requirements. This rule only adds more federal red tape and bureaucracy.”

Two industry groups, the Western Energy Alliance (WEA) and the Independent Petroleum Association of America (IPAA), filed a separate lawsuit against the rule on Nov. 15. District Court Judge Scott Skavdahl is the presiding judge in both cases.

Under the final rule, to be implemented in stages, oil and gas producers would be required to use currently available technologies and processes to cut flaring in half at oil wells on public and tribal lands. Operators would also be required to periodically inspect their facilities for leaks and replace outdated equipment that vents large quantities of gas into the air. Other parts of the rule require operators to limit venting from storage tanks and to use best practices to limit gas losses when removing liquids from wells.

Last June, Skavdahl ruled that the BLM does not have the authority to enforce a separate rule governing hydraulic fracturing (fracking) on public and tribal lands. The BLM subsequently appealed to the Tenth Circuit Court of Appeals in Denver. Oral arguments in that case, in which WEA and IPAA are petitioners, are scheduled to be heard on Jan. 17, 2017, three days before the inauguration of President-elect Donald Trump.

The states’ lawsuit against the methane rule in district court is State of Wyoming et al v. United States Department of the Interior et al[No. 2:16-cv-00285-SWS]. The WEA/IPAA lawsuit is Western Energy Alliance et al v. Secretary of the US Department of the Interior et al[2:16-cv-00280-SWS].