The state of Montana has asked to be included in a federal lawsuit in Wyoming brought by energy companies seeking to overturn federal approval of Montana's water quality standards for the Tongue and Powder rivers.
"Montana needs to have a voice in this lawsuit to make sure that our water quality standards are defended as vigorously as possible," Montana Attorney General Mike McGrath said Friday.
"Our standards are based on sound science. There's no doubt that, if these companies get away with negating them, water quality in these streams will suffer and it will be Montana irrigators who pay the price in lower production and damaged soils."
Montana submitted documents Thursday seeking to intervene in the lawsuit filed in U.S. District Court in Cheyenne.
In 2003, the Montana Board of Environmental Review adopted numeric standards for measures of salinity for the Tongue, Powder and their tributaries. Those rivers have headwaters in Wyoming and flow to the Yellowstone River in Montana. The standards are aimed at protecting the water from discharges of groundwater produced by drilling for coalbed methane. Water produced by drilling for the gas tends to run high in salts.
The U.S. Environmental Protection Agency approved Montana's water quality standards, making them enforceable under the federal Clean Water Act. As a result, companies extracting coalbed methane in Wyoming must make sure their discharges into streams flowing north into Montana meet Montana's standards at the border.
If Montana's standards are disregarded, discharges of tainted water from Wyoming may make the Tongue and Powder rivers unusable for farmers and ranchers in southeastern Montana, McGrath said.
Also, if the standards are exceeded by water coming from Wyoming, Montana's ability to develop its own coalbed methane gas resources would be limited, McGrath said.
In April, three energy companies — Pennaco Energy Inc., Marathon Oil Co. and Devon Energy Corp. — sued EPA in federal court, seeking judicial review to overturn its approval of the Montana standards. The case is being heard by U.S. Magistrate William C. Beaman.
The companies called EPA's approval illegal, unconstitutional and "an abuse of discretion." The companies hold mineral rights and are "negatively affected" by EPA's approval, they said.
The state of Wyoming intervened in May on the side of the companies.
The Wyoming filing said Montana's standards have caused it to have less flexibility in administering its water quality permits and less control over development of its natural resources. EPA's approval of the Montana rules has hurt Wyoming's statutory control of its water, natural resource development and collection of tax revenues, it said.
Montana's position is that its water quality standards are lawful and were adopted after public comment and scientific review.
"These standards were appropriately approved by EPA and this legal challenge is without foundation," McGrath said. "This is obviously a matter of out-of-state energy companies putting their profit margins ahead of our water quality and the agricultural producers, who, for generations, have depended on these rivers for their livelihoods."