It hasn’t been a good month for the EPA. A few weeks ago, EPA engineers accidentally breached a mine dam and polluted waterways in southwestern Colorado and northern New Mexico, after having bullied the landowner to access the mine. Ironically, their new rule that expands their authority by redefining the legal term “navigable waterways” was about to take effect tomorrow. A federal judge in North Dakota shut that down this afternoon, ruling that the EPA had exceeded its authority and jurisdiction from Congress:

A federal judge in North Dakota on Thursday blocked a new Obama administration rule that would give the federal government jurisdiction over some smaller waterways just hours before it was set to go into effect.

U.S. District Judge Ralph Erickson in Fargo issued a temporary injunction against a the rule which would have given the U.S. Environmental Protection Agency and Army Corps of Engineers authority over some streams, tributaries and wetlands under the Clean Water Act. The rule was scheduled to take effect Friday.

“The risk of irreparable harm to the states is both imminent and likely,” Erickson said in granting the request of 13 states to temporarily stop the rule from taking effect. The judge said that among other things, the rule would require “jurisdictional studies” of every proposed natural gas, oil or water pipeline project in North Dakota, which is at the center of an energy exploration boom.

The opinion can be found here. The government tried telling the judge that he didn’t have the jurisdiction to block the order, arguing that it had to go to the appellate court, but Erickson summarily rejected that argument. “If the exceptionally expansive view advocated by the government is adopted,it would encompass virtually all EPA actions under the Clean Water Act,” Erickson wrote of the procedural demand made by the EPA. “It is difficult to imagine any action the EPA might take in the promulgation of a rule that is not either definitional or regulatory.”

On the merits, Erickson ruled, the states were likely to succeed in their suit. Erickson highlights several applicable passages to Rapanos, in which Justice Anthony Kennedy joined in a concurrence that struck down an earlier attempt to expand the Clean Water Act to arrogate jurisdiction over wetlands. “While the Agencies assert that the definitions exclusion of drains and ditches remedies the defect,” Erickson writes of the overbroad rule, “the definition of a tributary here includes vast numbers of waters that are unlikely to have a nexus to navigable waters within any reasonable understanding of the term.”

Erickson also sees at least a fair chance of success for the states in proving the rule to be capricious and arbitrary:

The Rule asserts jurisdiction over waters that are remote and intermittent waters. No evidence actually points to how these intermittent and remote wetlands have any nexus to a navigable-in-fact water. The standard of arbitrary and capricious is met because the Agencies have failed to establish a “rational connection between the facts found” and the Rule as it will be promulgated.

The Rule also arbitrarily establishes the distances from a navigable water that are subject to regulation. … Once again, the court has reviewed all of the information available to it and is unable to determine the scientific basis for the 4,000 feet standard. Based on the evidence in the record, the distance from the high water mark bears no connection to the relevant scientific data purported to support this because any water that is 4,001 feet away from the high water mark cannot be considered “similarly situated” for purposes of 33 C.F.R. § 328.3(a)(8). While a “bright line” test is not in itself arbitrary, the Rule must be supported by some evidence why a 4,000 foot standard is scientifically supportable. On the record before the court, it appears that the standard is the right standard because the Agencies say it is.

This is, of course, just a temporary restraining order. Erickson will have to conduct a trial on the merits, and for the moment it’s unclear whether this applies to states not party to this suit. However, it seems at least somewhat likely based on these comments that Erickson isn’t likely to be convinced that the rule is either necessary or within the jurisdiction granted EPA by Congress. It may take long enough that the EPA will fall under a Republican administration, which can moot the entire question by withdrawing the rule change altogether.