EPA proposes 2027 general stormwater permit for construction

The Environmental Protection Agency (EPA) published the proposed 2027 National Pollutant Discharge Elimination System (NPDES) Construction General Permit (CGP) for public comment on August 3, 2026. The CGP covers stormwater discharges from construction activities.

Who’s impacted?

The CGP applies to construction activities in areas where EPA is the NPDES permitting authority (including Massachusetts, New Hampshire, New Mexico, and the District of Columbia). Construction site operators must obtain a stormwater discharge permit for any construction activity that:

• Disturbs 1 acre or more of land, or
• Disturbs less than 1 acre of land but is part of a larger common plan of development or sale that will disturb 1 acre or more of land.

What are the proposed changes to the CGP?

EPA’s proposed 2027 CGP contains multiple modifications to the 2022 CGP. Significant changes include:

• Replacing the broad requirement for permittees to “meet applicable water quality standards” for receiving waters (i.e., the waters that permittees discharge into) with more specific limits that indicate water quality problems in the discharge and applying these indicator conditions to all permittees;
• Requiring CGP applicants to submit with the Notice of Intent (NOI) an electronic copy of the Stormwater Pollution Prevention Plan (SWPPP), a website address where the SWPPP can be viewed, or a copy of the SWPPP site map and the signed certification;
• Requiring construction sites that install a sediment basin to implement stabilization measures before directing stormwater to the basin; and
• Streamlining specific requirements, such as:
  • Clarifying that perimeter sediment controls are only required for areas that may receive stormwater from disturbed areas;
  • Clarifying the stabilization deadlines for sites in arid, semi-arid, and drought-stricken areas;
  • Allowing sites that experience unforeseeable winter weather conditions to temporarily suspend the requirement to stabilize exposed portions of the site for 14 days or more of inactivity while the extreme weather conditions persist;
  • Eliminating the requirement to submit pre-stabilization photos with a Notice of Termination;
  • Reducing the frequency of turbidity monitoring from daily to weekly for sites discharging dewatering water continuously for longer periods of time;
  • Relieving some operators of turbidity benchmark monitoring reporting requirements at sites where multiple operators coordinate monitoring efforts (if the operators submit an initial quarterly report to inform EPA that they’re relying on another permitted operator on-site to monitor and report); and
  • Eliminating the reporting requirement when no dewatering discharges occur during a monitoring quarter.

Who needs to apply for 2027 CGP coverage?

Operators of both new sites (construction activities begin on or after the final 2027 CGP’s effective date) and existing sites must apply for coverage under the 2027 CGP.

If an existing site obtained permit coverage under the 2022 CGP before the permit’s expiration date (February 17, 2027), the site will automatically remain covered for a limited period of time, allowing operators to submit a new Notice of Intent for coverage under the 2027 CGP.

What’s next?

Public comments are due by September 2, 2026 (Docket ID No. EPA-HQ-OW-2025-0760).

EPA will host a webinar on August 18, 2026, to review the proposed 2027 CGP and answer questions. You may register for the webinar on EPA’s “Proposed 2027 Construction General Permit (CGP) and Related Documents” webpage. If the proposed 2027 CGP is finalized, it will replace the existing 2022 CGP, which expires on February 17, 2027.

Key to remember: EPA seeks public comment on the proposed 2027 Construction General Permit for stormwater discharges.