On August 27, the U.S. District Court in North Dakota placed a preliminary injunction on the implementation of the Clean Water or Waters of the U.S. (WOTUS) Rule that was set to go into effect the next day. Chief District Judge Ralph Erickson ruled that in finalizing the rule, the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers likely failed to comply with the Administrative Procedures Act and overstepped their authority beyond congressional intent. According to the court the WOTUS rule, which sought to clarify the definition of streams and wetlands, may have too broad of a definition of navigable waters. The court issued the injunction because it agreed with states in the suit that they could face irreparable harm due to federal infringement of state sovereignty if the rule went into effect.

"The Rule allows EPA regulation of waters that do not bear any effect on the ?chemical, physical, and biological integrity' of any navigable-in-fact water. While the Technical Support Document states that pollutants dumped into a tributary will flow downstream to a navigable water, the breadth of the definition of a tributary set forth in the Rule allows for regulation of any area that has a trace amount of water so long as ?the physical indicators of a bed and banks and an ordinary high water mark' exist," wrote Judge Erickson. "While the Agencies assert that the definition's exclusion of drains and ditches remedies the defect, 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."

The court ruling immediately stopped implementation of the rule in the 13 states that joined in the lawsuit ? including North Dakota, Alaska, Arizona, Arkansas, Colorado, Idaho, Missouri, Montana, Nebraska, Nevada, South Dakota, Wyoming and the New Mexico Environment Department. Immediately after the decision, the EPA announced that they would respect the judgment in those states but would continue to enforce the rule in the remainder of the states. However, the states that filed the original suite then filed a notice contending that the preliminary injunction should apply nationally. The court responded on September 4 that it would not extend the injunction because four other district courts, including federal judges in West Virginia and Georgia, have denied or deferred decisions on preliminary injunctions in their region for various reasons. The injunction will stay in place as legal proceedings move forward on the case.