Change in NPDES Construction General Permit

Under the United States Clean Water Act (CWA), construction stormwater discharges into waters of the U.S. (WOTUS) must be authorized by a state or U.S. Environmental Protection Agency (U.S. EPA) National Pollutant Discharge Elimination System (NPDES) permit.

U.S. EPA Construction General Permit (CGP) under the NPDES program applies to states which do not have authority to issue their own NPDES permits and include Massachusetts, New Hampshire, New Mexico, the District of Columbia, and all U.S. territories (except for the U.S. Virgin Islands). Some states also model their own NPDES permits based on the U.S. EPA permits.

Changes to the GCP

On April 8, 2025, U.S. EPA finalized a modification to the 2022 CGP effective immediately for U.S. EPA Regions 2, 4, 5, 6, 7, 8, 9, and 10. For U.S. EPA Regions 1 (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont) and Region 3 (Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, West Virginia), the modification’s effective date is pending. These regions require additional time to complete the Clean Water Act section 401(a)(2) process. The modification expanded the CGP scope to include construction projects in Lands of Exclusive Federal Jurisdictions (LEFJ), which are lands in the U.S. where the Federal Government maintains full jurisdiction. Not all federal lands are LEFJ and there is no master list of LEFJ because it is tracked by multiple agencies within the federal government and changes over time. LEFJ were not explicitly covered under the 2022 CGP, but U.S. EPA “finds the most effective way to provide such permit coverage is through a modification to the 2022 CGP” per the CGP 2022 Fact Sheet.

Not related but included in the modification, U.S. EPA is updating water quality-based limitations in light of the Supreme Court’s decision in San Francisco. The decision ruled that the CWA does not allow “NPDES permit requirements that condition permitholders’ compliance on whether receiving waters meet applicable water quality standards.” In accordance with this the new CGP added discharge water-based limitations and removed “generic narrative prohibition” of final water quality that was rejected by the courts. Per the CGP 2022 Fact Sheet the new GCP “Section 10…makes a conforming change to indicate that triggering conditions for corrective actions in Part 5.1.3 and limits on the use of treatment chemicals in Part 7.2.6 focus on conditions within the construction site’s discharge”. State specific implementation and timeline of removal of the “generic narrative prohibition” will vary by state.

What Can I Do

If you have a construction project located in LEFJ, assess whether the modified 2022 CGP applies to your activities. If you have a construction project which falls into a LEFJ and requires a CGP, ensure timely submission of the Notice of Intent (NOI) form to obtain coverage under the modified CGP.

If you need help determining the applicability of the CGP to your site or preparation and submittal of the NOI, please contact Evan Mia of ALL4 at emia@all4inc.com