On January 22, 2018, the Supreme Court ruled in National Assoc. of Manufacturers v. Department of Defense that federal district courts have original jurisdiction to hear challenges to the 2015 Obama Administration Waters of the U.S. (WOTUS) rule which defined the extent of federal jurisdiction over streams and wetlands under the Clean Water Act.  After the ruling, the Trump Administration was concerned that the 2015 WOTUS Rule may be effective before it completes it’s own process to remove the rule and promulgate its own rule defining the extent of federal jurisdiction over waters in the United States.  

On February 6th, the EPA and Army Corps of Engineers adopted a new rule which establishes an "applicability date" of the 2015 WOTUS Rule.  The applicability date as established by the rule is February 6, 2020 which will provide time for the Trump Administration to complete the process of unwinding the 2015 WOTUS Rule and adopt its own rule defining federal jurisdiction.

The effective date of the 2015 WOTUS Rule was August 28, 2015, however, the Agency’s assert that the 2015 WOTUS Rule did not establish an "applicability date."  Therefore, the EPA and Army Corps assert that, until the applicability date passes, the Agencies will define waters and wetland falling under federal jurisdiction “consistent with Supreme Court decisions and practice and as informed by applicable agency guidance documents (the 2003 and 2008 guidance documents) as the agencies have been operating pursuant to the Sixth Circuit’s October 9, 2105, order, and the North Dakota district court’s injunction.” (The North Dakota District Court issued an injunction preventing implementation of the 2015 WOTUS Rule).

The Trump Administration believes the "applicability" rule allows the regulatory interpretation of jurisdiction under the Clean Water Act in effect prior to the 2015 WOTUS Rule to remain in place.  It is very likely this rule will also be challenged on the basis the August 28, 2015 effective date of the 2015 WOTUS Rule cannot be delayed in this manner.