The State of Wyoming has joined a lawsuit filed against the EPA and the US Army Corps of Engineers over the agencies’ Waters of the United States rule.

The EPA sent its controversial regulation to redefine the extent of its authority over water pollution control last month.

However, the agriculture, oil and home-building industry have been lining up to attack the rule aimed at protecting wetlands and waterways.

Congress voted last month to block the rule, with support from both Republicans and energy-state Democrats, while similar legislation moves has been moving through the Senate.

On the face of it, the Waters of the United States rule is a largely technical document that defines which rivers, streams, lakes and marshes fall under the jurisdiction of the EPA and the Army Corps of Engineers.

But opponents have labelled it yet another power grab, echoing US coal magnate Robert Murray’s accusation that US President Barack Obama and the EPA are doing the same to the nation’s power grid.

In announcing the move, Wyoming Governor Matt Mead, who has opposed the rule since it was first proposed said he was disappointed with the “lack of consideration shown to the states” throughout this process.

“When I saw the original draft of the rule it was so flawed, I asked the agencies to withdraw it,” Mead said.

“Nonetheless, the agencies, without addressing significant concerns raised by Wyoming and other states, charged ahead.”

The Clean Water Act recognises states as having primary responsibility for land and water within their boundaries.

The coalition which filed the complaint on Monday included the states of North Dakota, Alaska, Arizona, Arkansas, Colorado, Idaho, Missouri, Montana, Nebraska, Nevada, South Dakota, and Wyoming. The New Mexico Environment Department and New Mexico State Engineer are also parties.

“This rule expands the reach of federal agencies to lands and waters beyond the bounds set by Congress,” Mead added. “It is wrong for Wyoming – for every state and for the United States – and it is unlawful.”

On Monday the US Supreme court sided with state and industry groups in the Michigan versus Environmental Protection Agency case, which was seen as a key environmental case that sought to determine if the EPA must consider how costly it would be for power plants to comply with environmental rules before deciding to implement them.

In its opinion, delivered by Justice Scalia, the Court determined that in fact, “the EPA must consider cost – including cost of compliance – before deciding whether regulation is appropriate and necessary. It will be up to the Agency to decide (as always, within the limits of reasonable interpretation) how to account for cost”

The EPA had argued that the costs of implementation should not be considered until it issues specific pollution standards.

On the other hand, state and industry groups argued the EPA should consider the costs of implementing regulations before requiring power plants to comply with them. These groups warned that setting limits on emissions of mercury and other pollutants would be prohibitively expensive for the power plants.

Coal companies jump for joy

US coal stocks, meanwhile, rallied at the news of the Supreme Court’s decision to throw out the EPA’s landmark rules requiring coal-fired plants to cut emissions of mercury and other toxic air pollutants.

Walter Energy (28.2%), Arch Coal (15.1%), Peabody Energy (11.2%), Alpha Natural Resources (5.4%), Cloud Peak Energy (5.2%), Rhino Resource Partners (3.9%), Westmoreland Coal (1.9%) and Consol Energy (1.4%) all surged on the news.

Meanwhile, utilities American Electric Power Company, PG&E Corporation, Dominion Resources, NextEra Energy and Exelon Corporation also made slight gains.

West Virginia governor Earl Ray Tombline also praised the Supreme Court’s ruling against the EPA.

“As we have maintained for years, the EPA far too often fails to consider the impact its mandates have on jobs and the economies of both our state and our nation,” he said.

He expressed hope that the decision would encouraged those making “these unreasonable decisions to reconsider their plans not only for mercury emissions but the unreasonable restrictions this administration wants to put on existing power plants”.

Murray Energy also threw in its two cents.

“Indeed, the Obama EPA will also be unable to justify its so-called Clean Power Plan, which similarly imposes billions of dollars in costs, with no discernible environmental benefit whatsoever,” the company said.