Proposed rule · 2026-18134

Updates to the National Pollutant Discharge Elimination System Definitions and Exclusions

The U.S. Environmental Protection Agency (EPA) proposes to revise a regulatory definition under the Clean Water Act (CWA) permitting regulations pertaining to discharges in the contiguous zone and ocean. The proposal would revise the regulatory definition of "discharge of a pollutant" to reflect and faithfully implement the statutory exclusion of vessels and other floating craft that add pollutants in the contiguous zone or the ocean from inclusion in the definition of "discharge of a pollutant" or "discharge", and thus, from National Pollutant Discharge Elimination System (NPDES) program requirements. The proposed rulemaking would also make conforming and clarifying changes to the NPDES regulatory exclusion for vessels and other floating craft. The effect of these changes would be that the addition of pollutants by a vessel or other floating craft in the contiguous zone or the ocean that is not secured to the seabed would not be a discharge and would not require CWA NPDES permit authorization to add pollutants to those waters.