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Watershed Planning Program: Surface Water Quality Standards Review and Development Activities

The Watershed Planning Program’s Surface Water Quality Standards (SWQS) Section regularly reviews and revises the Massachusetts SWQS regulation (314 CMR 4.00) and policies based on the latest available science to restore and protect surface waters.


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Overview

Triennial Review

The federal Clean Water Act (CWA) 33 USC 1251 et seq., and associated Water Quality Standards regulations at 40 Code of Federal Regulations (CFR) Part 131, 40 CFR 131 require states to periodically review and update their water quality standards in a process called the Triennial Review. During this process, the SWQS Section reviews water quality criteria guidance from the U.S Environmental Protection Agency (EPA) for potential adoption into 314 CMR 4.00. The SWQS Section may also develop or refine criteria, which involves extensive research and scientific expertise as well as stakeholder engagement and inter- and intra-agency coordination. States also must also provide a public explanation for any EPA criteria guidance not adopted.

Amendments to the MA SWQS are enforceable by the Commonwealth, but federal Water Quality Standards regulations require that revisions to state water quality standards be approved by EPA for the revisions to be federally enforceable for CWA purposes (including, for example, application of the MA SWQS for water quality assessments and National Pollutant Discharge Elimination System permits). MA SWQS amendments are completed through a formal regulatory process in accordance with the Massachusetts Administrative Procedures Act, M.G.L. c. 30A.

2021 Triennial Review

On November 12, 2021, MassDEP promulgated amendments to the MA SWQS, 314 CMR 4.00. Subsequently, MassDEP published two sets of corrections, effective December 10, 2021, and January 7, 2022. 

Opportunities for SWQS Review

Triennial reviews provide an opportunity for the public to participate in the process to potentially amend the MA SWQS. In May 2022, MassDEP’s Watershed Planning Program started the current triennial review process by hosting two remote public “Listening Sessions” to receive suggestions on future criteria development, priority surface waters for protection or restoration, and other topics of interest pertaining to the MA SWQS.

Current Triennial Review

MassDEP developed proposed amendments to the MA SWQS with several purposes including:  (1) addressing EPA deferred actions and disapprovals from the 2021 promulgation process; (2) revising pathogen water quality criteria that protect human health during activities such as boating; (3) improving waterbody descriptions; (4) updating copper criteria adjustment procedures; (5) removing unused surface water classifications; and (6) making minor improvements and corrections. See the link below under “Document Availability” for two versions of the regulation reflecting the proposed amendments (a clean version and a redline version), as well as a detailed summary of the proposed amendments. The amendments will make the MA SWQS clearer and easier to apply, improve human health and environmental protections, employ the latest science, and align with EPA requirements.

Public Hearing Notice: Proposed Amendments to the MA SWQS (314 CMR 4.00)

On January 2, 2026, MassDEP published a Public Hearing Notice concerning proposed amendments to 314 CMR 4.00: MA SWQS pursuant to M.G.L. c. 21, §§ 26–53, M.G.L. c. 30A, and Section 303 of the federal Clean Water Act (33 U.S.C. § 1313).

  • Public Notice & Comment Period: MassDEP published the Public Hearing Notice in the Boston Globe, the Worcester Telegram and Gazette, and the Environmental Monitor, and opened a 30-day public comment period that will close on February 9, 2026.  A link to the Public Hearing Notice is provided below under “Document Availability”.
  • Public Hearing Dates and Registration Links: The public hearings to receive comments on the proposed amendments will be held virtually under the provisions of M.G.L. Chapter 30A on:
    • Tuesday, January 27, 2026, at 6:00 PM; and
    • Wednesday, January 28, 2026, at 2:00 PM.

Testimony may be presented at the hearings, and written comments may be submitted until 5:00 PM on Monday, February 9, 2026. Written comments must be submitted via email or physical mail. Comments may be submitted via email to dep.wpp@mass.gov using the subject line: “Public Comments – Proposed MA SWQS Amendments” or by physical mail to: Anna Mayor, MassDEP Watershed Planning Program, 8 New Bond Street, Worcester, MA 01606. Advanced registration to attend the virtual Zoom hearings is required. The registration links are provided below:

Document Availability

The proposed amended regulation, a summary of the amendments, and the Public Hearing Notice can be accessed using the links below:

How to Stay Informed

Check this page regularly for updates. To receive notices of future review opportunities you may also subscribe to the Watershed Planning Program’s mailing list or contact MassDEP’s Watershed Planning Program by Email at dep.wpp@mass.gov. To receive MassDEP’s Regulations Updates & Related Notifications sign up here.

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