On January 29, the U.S. Court of Appeals for the Tenth Circuit became the latest federal Court of Appeals to issue a ruling reviving federal District Court challenges to the 2015 Environmental Protection Agency’s (EPA)/U.S. Army Corps of Engineers’ (Corps) Clean Water Act (CWA) rule redefining “Waters of the United States.” The United States District Court for the Northern District of Oklahoma dismissed challenges to this rule filed by the Chamber of Commerce, the National Federation of Businesses, Tulsa Regional Chamber, Portland Cement Association, and the State Chamber of Oklahoma, holding that the appeal must be brought in the US Court of Appeals. The Tenth Circuit abated these appeals, pending the decision of the U.S. Supreme Court in National Assoc. of Manufacturers v. Department of Defense (the NAM Decision). On January 22, 2018, the Supreme Court held that such challenges must be filed in the federal district courts, causing the Tenth Circuit to lift the abatement, and return the case to the District Court. The Tenth Circuit case is Chamber of Commerce of the U.S, et al. v. EPA, et al.