The first lawsuit has been filed in the US District Court for the Northern District of West Virginia, and the second will be filed in the US Court of Appeals for the Sixth Circuit.

On the face of it, the Waters of the US 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 like Murray Energy have labelled it yet another power grab. The lawsuits are another step in Murray Energy's legal campaign to stop the EPA’s “illegal actions and to restore the rule of law in this country”, Murray Energy assistant general counsel Gary Broadbent said.

“The Obama EPA's final ‘waters of the US' rule not only reflects an unprecedented expansion in federal regulatory authority, but results in one of the largest land grabs by the federal government in this nation's history,” he said.

“The Obama EPA is seeking to expand jurisdiction over dry ditches, puddles, ponds, and erosional features, dictating to Americans how they can and cannot use their private property.

“Under the Obama EPA's rule, any area that is wet, or has the potential to be wet, would be subject to the Clean Water Act. Congress clearly did not intend such a radical and illogical outcome.”

In 1972, when Congress adopted the Clean Water Act, it expressly limited the federal government's authority to “navigable waters”. Over the years, however, the EPA has engaged in “regulatory creep”, expanding its rules and authority under the Clean Water Act to include not only navigable waters, but dry lands and activities potentially affecting those areas, according to Murray Energy.

In 2001 and 2006, the US Supreme Court rendered opinions that struck down the EPA's impermissible expansion of authority.

The EPA now continues to aggressively push beyond the limits of its authority, according to Broadbent.