Region 1 Final New Hampshire Medium Wastewater Treatment Facility General Permit

EPA Region 1 has issued the National Pollutant Discharge Elimination System (NPDES) General Permit for the discharge of wastewater from medium-sized wastewater treatment facilities (WWTFs) in the State of New Hampshire (Permit Number NHG590000), referred to as the "New Hampshire Medium Wastewater Treatment Facility General Permit" ("NH Medium WWTF GP" or the " General Permit").

The NH Medium WWTF GP is designed to authorize discharges of wastewater from publicly owned treatment works (POTWs) treating domestic sewage. Facilities eligible for coverage under the General Permit include those that discharge to fresh and marine waters in New Hampshire with a design flow between 1 and 5 million gallons per day (MGD). The NH Medium WWTF GP proposes effluent limitations, monitoring requirements, reporting requirements and standard conditions. Specific eligibility and notification requirements are provided for in the General Permit. See Attachment E of the NH Medium WWTF GP in the link below for a list of the 21 eligible facilities.

EPA solicited public comments on the Draft NH Medium Wastewater Treatment Facility GP from November 13, 2024 to February 12, 2025. EPA received many comments during this time and made several changes to the NH Medium WWTF GP as described in EPA's Response to Comments document posted below.

The NH Medium WWTF General Permit was issued on November 3, 2025, and the effective date is February 1, 2026. Although not required to obtain coverage, eligible facilities may choose to submit a Notice of Intent (NOI) to EPA in accordance with 40 CFR § 122.28(b)(2)(i) & (ii). The details of such a submittal are outlined in the Part III.A of the General Permit. As a convenience, eligible facilities may use this NOI template (pdf) (109 KB) and submit their NOI electronically to R1NPDESReporting@epa.gov (with copy to Duspiva.Michele@epa.gov) at any time before the deadline of March 2, 2026.

Note that eligible facilities will not be covered by the General Permit until the effective date of their authorization.

• NH Medium WWTF General Permit (pdf) (596 KB)
  • Part VII – Standard Conditions (pdf) (354 KB)
  • Attachment A – Freshwater Acute Toxicity Test Procedure and Protocol, February 2011 (pdf) (246 KB)
  • Attachment B – Freshwater Chronic Toxicity Test Procedure and Protocol, March 2013 (pdf) (171 KB)
  • Attachment C – Marine Acute Toxicity Test Procedure and Protocol, July 2012 (pdf) (181 KB)
  • Attachment D – Marine Chronic Toxicity Test Procedure and Protocol, November 2013 (pdf) (224 KB)
  • Attachment E – List of Eligible Facilities and Facility-Specific Requirements (pdf) (92 KB)
  • Attachment F – Reassessment of Technically Based Industrial Discharge Limits (pdf) (1.6 MB)
  • Attachment G – Industrial Pretreatment Program Annual Report (pdf) (135 KB)
  • Attachment H – PFAS Analyte List (pdf) (250 KB)
  • Attachment I – List for Pollutant Scans (pdf) (512 KB)
• EPA's Response to Comments (pdf) (3.7 MB)
• New Hampshire State Water Quality Certification (pdf) (299 KB)

All authorizations will be posted below once they are effective and will be available for public access throughout the permit term.