Maryland’s 2019 Triennial Review of Water Quality Standards



MDE will be accepting comments on the 2019 Triennial Review from March 11th to April 11th 2022. Interested stakeholders can review and comment on the proposed regulatory changes and ​supporting material provided on this webpage. A virtual public hearing was held on ​March 30, 2022 at 5pm to present on the proposed changes. Stakeholders are invited to comment both on the proposed ​changes to water quality standards and on other water quality standards of interest. 

Comments can be submitted during the public comment period to Matthew Stover ​at​ or to the following address

Mr. Matthew Stover
Maryland Department of the Environment
1800 Washington Blvd.
Baltimore, MD 21230

What is the Triennial Review of Water Quality Standards?  

The purpose of water quality standards is to protect, maintain and improve the quality of Maryland’s surface waters. Water quality standards have three components: Designated Uses, Water Quality Criteria, and an Antidegradation Policy. The Clean Water Act (CWA) requires that States review their water quality standards every three years (Triennial Review) and revise the standards as necessary.  The Environmental Assessment and Standards Program has compiled proposed amendments to Maryland’s Water Quality Standards regulations associated with the 2019 Triennial Review. Information regarding the previous 2013 and 2016 Triennial Reviews can be found here​.​

Proposed Regulatory Changes and Review of Water Quality Standards

The document immediately below provides the specific proposed regulatory language proposed for revision in the Code of Maryland Regulations and a summary of what water quality standards were reviewed.

The following documents are being considered for incorporation by reference into the Code of Maryland Regulations (COMAR).  If adopted they will have the same authority and weight as regulatory language captured in COMAR.

Materials from the Public Hearing on March 30, 2022

Supporting Materials for this Triennial Review  

The following documents will not be incorporated by reference but provide supporting information, justification and context for the proposed amendments to Maryland’s water quality standards.  

Designated and Existing Uses
Recent data have shown that the current use classification of some Maryland surface waters are not protective of their existing use. The existing uses of these streams will be formally recognized by the department and some surface waters will be reclassified to use class III (or III-P) where data have demonstrated that the designated use and criteria are being attained. The following documents provide justification for and describe the scale of existing use determinations and use classification changes where applicable.

Water Quality Criteria

Antidegradation Policy​​

Contact Information 

For more information, please contact Matthew Stover at​ or at (410) 537-3611.​

This page was last updated on 04/2022

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