13 states led by North Dakota are asking a federal judge in Bismarck to block a new rule that gives federal authorities jurisdiction over some state waters.
North Dakota Attorney General Wayne Stenehjem says he will request a preliminary injunction Monday.
The states filed a lawsuit in June challenging the rule by the U.S. Environmental Protection Agency and the Army Corps of Engineers. The states say the new rule illegally expands the jurisdiction of those agencies under the federal Clean Water Act.
The law goes into effect Aug. 28.
The injunction seeks to suspend the new rules until a court can decide the case. The other states joining the lawsuit with North Dakota are Alaska, Arizona, Arkansas, Colorado, Idaho, Missouri, Montana, Nebraska, New Mexico, Nevada, South Dakota and Wyoming.