Region 1 Final Medium Wastewater Treatment Facilities General Permit for Massachusetts

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 Commonwealth of Massachusetts (Permit Number MAG590000), referred to as the "Medium Wastewater Treatment Facilities General Permit" ("Draft Medium WWTF GP" or the "Draft General Permit").

The Medium WWTF GP is designed to authorize discharges of wastewater from privately and publicly owned treatment works treating domestic sewage. Facilities eligible for coverage under the General Permit would include those in Massachusetts with a design flow between 1 and 5 million gallons per day (MGD). The Medium WWTF GP proposes effluent limitations, monitoring requirements, reporting requirements and standard conditions for facilities that discharge to fresh and marine waters in the Commonwealth of Massachusetts. Specific eligibility and notification requirements are provided for in the General Permit. See Attachment E of the Medium WWTF GP in the link below for a list of the 43 eligible facilities.

EPA solicited public comments on the Draft Medium WWTF General Permit from February 8, 2022 to April 26, 2022. EPA received many comments during this time and made several changes to the Medium WWTF GP as described in EPA's Response to Comments document posted below.

The Medium WWTF General Permit was issued on September 28, 2022 and the effective date is November 1, 2022. 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 IV.A of the General Permit. As a convenience, eligible facilities may use this NOI template (pdf) (110 KB) and submit their NOI electronically to [email protected] (with copy to [email protected]) at any time before the deadline of December 1, 2022. Note that eligible facilities will not be covered by the General Permit until the effective date of their specific authorization, discussed below.

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

• Medium WWTF General Permit (pdf) (462 KB)
  • Part VII – Standard Conditions (pdf) (326 KB)
  • Attachment A – Freshwater Acute Toxicity Test Procedure and Protocol, February 2011 (pdf) (113 KB)
  • Attachment B – Freshwater Chronic Toxicity Test Procedure and Protocol, March 2013 (pdf) (105 KB)
  • Attachment C – Marine Acute Toxicity Test Procedure and Protocol, July 2012 (pdf) (109 KB)
  • Attachment D – Marine Chronic Toxicity Test Procedure and Protocol, November 2013 (pdf) (128 KB)
  • Attachment E – List of Eligible Facilities (pdf) (169 KB)
  • Attachment F – Reassessment of Technically Based Industrial Discharge Limits (pdf) (946 KB)
  • Attachment G – NPDES Permit Requirement for Industrial Pretreatment Annual Report (pdf) (68 KB)
  • Attachment H – PFAS Analyte List (pdf) (227 KB)
  • Attachment I – Facility-Specific Permit Terms (pdf) (6 MB)
  • Attachment J – Pretreatment Program Development Requirements (pdf) (158 KB)
• EPA's Response to Comments (pdf) (4.5 MB)
• 2023 Medium WWTF GP Minor Modification Letter (pdf) (166 KB)
• 2023 Medium WWTF GP Minor Modification Letter Medfield (pdf) (178 KB)
• Permittee PFAS Clarification Letter (pdf) (160 KB)
• Massachusetts State Water Quality Certification, dated July 1, 2022 (pdf) (245 KB)
• Medium WWTF General Permit Fact Sheet (Including Appendices A, B, and C) (pdf) (1.2 MB)
• 2024 Medium WWTF GP Minor Modification Letter Spencer (pdf) (262 KB)

After the General Permit becomes effective, EPA will send each eligible Permittee an authorization which will include their specific permit limits and other requirements and will indicate the date that their coverage under the General Permit will begin. All authorizations will be posted below once they are effective and will be available for public access throughout the permit term.

Authorizations: