Region 1 Final Small Wastewater Treatment Facilities General Permit

2021 Final Small Wastewater Treatment Facilities General Permit for Massachusetts and New Hampshire and 2023 Modification

EPA Region 1 has issued the National Pollutant Discharge Elimination System (NPDES) General Permits for the Discharge of Wastewater from Small Wastewater Treatment Facilities (WWTFs) in the Commonwealth of Massachusetts and the State of New Hampshire. General Permit MAG580000 applies to discharges in Massachusetts, and General Permit NHG580000 applies to discharges in New Hampshire. Unless otherwise specified, these two permits are collectively referred to as the "Small Wastewater Treatment Facilities General Permit" ("Small WWTF General Permit" or the "General Permit").

The Small WWTF General Permit is designed to authorize discharges of wastewater from publicly owned treatment works and other treatment works that treat domestic sewage. Facilities eligible for coverage under the General Permit would include those in Massachusetts and New Hampshire with a design flow less than one million gallons per day (MGD). The Small WWTF General Permit replaces the Publicly Owned Treatment Works General Permit (POTW GP) that was effective on July 6, 2011 and expired on July 6, 2016. The Small WWTF General Permit establishes effluent limitations, monitoring requirements, reporting requirements and standard conditions for facilities that discharge to fresh and marine waters in the Commonwealth of Massachusetts and the State of New Hampshire. Specific eligibility and notification requirements are provided for in the General Permit. See Attachment E of the Small WWTF General Permit in the link below for a list of the eligible facilities.

The 2021 Small WWTF General Permit was issued on September 28, 2021 and became effective on December 1, 2021.

From October 27, 2022, through January 25, 2023, a Draft Modification of the Small WWTF General Permit was made available for public review and comment which included several proposed changes and added several newly eligible WWTFs. The 2023 Modified Small WWTF General Permit was issued on March 29, 2023 and will become effective on June 1, 2023.

Newly eligible facilities under the 2023 Modified Small WWTF GP 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 V.A of the 2023 Modified Small WWTF General Permit. As a convenience, eligible facilities may use this NOI template (docx) (24 KB) and submit their NOI electronically to [email protected] (with copy to [email protected]) at any time before the deadline of June 27, 2023.

A copy of the Small WWTF General Permit and other relevant documents are posted here:

2023 Modified Small GP Documents

• 2023 Small WWTF General Permit Modification (pdf) (659 KB)
  • Part VIII – Standard Conditions (pdf) (327 KB)
  • Attachment A – Freshwater Acute Toxicity Test Procedure and Protocol, February 2011 (pdf) (126 KB)
  • Attachment B – Freshwater Chronic Toxicity Test Procedure and Protocol, March 2013 (pdf) (104 KB)
  • Attachment C – Marine Acute Toxicity Test Procedure and Protocol, July 2012 (pdf) (115 KB)
  • Attachment D – Marine Chronic Toxicity Test Procedure and Protocol, November 2013 (pdf) (132 KB)
  • Attachment E – List of Eligible Facilities, March 2023 (pdf) (166 KB)
• 2023 EPA's Response to Comments (pdf) (505 KB)
• Massachusetts State Water Quality Certification, dated February 24, 2023 (pdf) (163 KB)
• New Hampshire State Water Quality Certification, dated February 24, 2023 (pdf) (307 KB)
• Statement of Basis (Including Appendices A, B, and C) (pdf) (7.2 MB)

2021 Small WWTF GP Documents

• 2021 Small WWTF General Permit (pdf) (586 KB)
  • Part VIII – Standard Conditions (pdf) (327 KB)
  • Attachment A – Freshwater Acute Toxicity Test Procedure and Protocol, February 2011 (pdf) (126 KB)
  • Attachment B – Freshwater Chronic Toxicity Test Procedure and Protocol, March 2013 (pdf) (104 KB)
  • Attachment C – Marine Acute Toxicity Test Procedure and Protocol, July 2012 (pdf) (115 KB)
  • Attachment D – Marine Chronic Toxicity Test Procedure and Protocol, November 2013 (pdf) (132 KB)
  • Attachment E – List of Eligible Facilities, September 2021 (pdf) (123 KB)
• EPA's Response to Comments (including Appendices A and B) (pdf) (1.2 MB)
• Massachusetts State Water Quality Certification, dated June 7, 2021 (pdf) (240 KB)
• New Hampshire State Water Quality Certification, dated June 4, 2021 (pdf) (231 KB)
• Small WWTF Fact Sheet (pdf) (933 KB)

All authorizations for the Small WWTF GP are available below for public access.