The State is required, under the federal Clean Water Act, to periodically update its Water Quality Standards to reflect the latest scientific understanding of water pollution effects and to accommodate changes in state and federal law.  Final revisions to the Water Quality Standards became effective on February 25, 2011, after approval by the federal Environmental Protection Agency.  The final document was developed after consideration of public comments provided on proposed revisions to the Standards. 

The Water Quality Standards form the foundation of Connecticut’s efforts to maintain and improve the quality of its waters and are required by both state and federal law.  The Standards articulate State policies regarding the uses and related classifications of Connecticut’s water resources, and the standards and criteria necessary to support such designated uses.   

Administrative Procedure for the Revisions

In the spring of 2009, DEEP announced its intent to review and revise the Water Quality Standards and identified topics being considered for revision.  These included:  antidegradation provisions of the Standards; dissolved oxygen criteria for marine waters; a nutrient control implementation strategy; and updating the criteria for toxics pollutants.  At that same time, DEEP solicited input from the public regarding additional topics that should be considered for review and revision of the Standards. 

After carefully considering the public feedback and conducting a review of the 2002 Water Quality Standards, (PDF) (December 17, 2002), DEEP proposed revisions in December of 2009. The proposed revisions included general changes to improve the organization and clarity of the document and an update of definitions and regulatory references.  The proposed revisions also included the following: 

An informational meeting on the proposal was held in late January, a public hearing in early February and the public comment period was held open until March 17, 2010.  Nine individuals provided oral comment at the hearing and twenty-five comment letters were received. 

Following review and consideration of the oral and written public comment submitted concerning the December 2009 Water Quality Standards, DEEP made revisions to this proposal.  As a result, the 2011 Water Quality Standards do not include all the revisions proposed in 2009 and takes an incremental and modest approach that meets DEP's environmental responsibilities under the federal Clean Water Act while reflecting concerns that DEEP heard from various parties during the public hearing process.  Please see the Hearing Officer's Report (PDF) for a complete discussion of the changes.  The changes will be discussed at the January 12 Forum, and all interested parties are encouraged to attend.  

The following are the highlights for revisions made in response to public comment:

CT DEEP proposed updates to the numeric water quality criteria pursuant to federal requirements of the Clean Water Act and associated federal guidance.  While the proposed revisions were consistent with those requirements and with guidance established by the EPA for developing water quality criteria, CT DEEP acknowledges strong public sentiment to allow for additional dialogue concerning the derivation of such criteria and the ultimate implementation of these criteria into regulatory programs.  Therefore, CT DEEP is not moving forward at this time with the revisions to the water quality criteria as proposed in December 2009, but will make a minimal number of changes as listed below.  Additional information is provided in the Hearing Officer's Report.(PDF)  Tables comparing the updated  2011 water quality criteria with those in the 2002 Water Quality Standards and the proposed 2009 revisions to the Water Quality Standards are presented in Appendices E and F (PDF) to the Hearing Officer's Report, respectively.

The narrative standard for nutrients within the Water Quality Standards has been revised to better reflect the intent to protect and maintain designated uses for surface waters from the effects of excessive anthropogenic inputs of nutrients.  CT DEEP has concluded that there is insufficient information currently available to support adoption of biologically based numeric nutrient criteria.  While CT DEEP continues to work towards deriving appropriate numeric criteria, the narrative standard will continue to provide protection of water quality consistent with federal requirements. 

Accordingly, Appendix F in the proposed 2009 revisions to the Water Quality Standards (Nutrient Criteria and Implementation Policy) has been removed.  CT DEEP will consult with stakeholders while continuing to work with EPA in developing appropriate implementation strategies, and ultimately numeric criteria.

CT DEEP is withdrawing proposed changes to temperature criteria and will continue to utilize the standards and criteria in the 2002 Water Quality Standards. The current standard prohibits changes from natural conditions that would impair any existing or designated uses, as well as a numeric temperature limit and the limitation that temperature of surface water not be increased more than 4^o F.  CT DEEP recognizes the need to further document conditions specific to Connecticut and establish implementation protocols.  CT DEEP is committed to moving towards an approach that determines thermal tolerance of various fish species and establishes thermal classes (coldwater surface waters, cool water surfaces waters and warm water surface waters) for freshwater streams and rivers.

A definition of the term “natural” has been added to the Water Quality Standards and is limited to the biological, chemical and physical conditions and communities that occur within the environment which are unaffected or minimally affected by human influences.  References to Best Management Practices are no longer associated with the term “natural” within Water Quality Standard 8.  

The Connecticut Department of Energy and Environmental Protection uses the Department web site to provide information about topics pertaining to water quality based programs within Connecticut.  The Department is in the process of setting up a list server to provide notice to interested parties of updates regarding water quality planning programs.  Please check back on this web site in the near future to subscribe to the listserv.

2011 CT Water Quality Standards  (PDF) Final, adopted February 25, 2011

Maps to accompany 2011 CT Water Quality Standards (Final)

WQS Hearing Officer's Report January 4, 2011  

Report through Appendix D (PDF)

Appendices E and F (PDF)
Appendix G (PDF)

2011 Revised Water Quality Standards Plain Text (proposed January 2011) (PDF)

2011 Revised (1/11) WQS Showing Changes from 2009 Proposal (PDF)

Water Quality Classification Maps (proposed January 2011)

Transmittal letter to USEPA Region 1 - January 4, 2011 (PDF)

Legal Certification - January 4, 2011 (PDF)

WQ Classification Maps Cover Sheet - January 4, 2011 (PDF)

Wingfield to Silva letter January 7, 2011 (PDF)

WQS Revisions Public Presentation January 14, 2011 (PDF)

Supporting Documentation for Proposed Modifications to Connecticut Site-Specific Copper Criteria - January 19, 2011 (PDF)

Wingfield Response to Silva letter - January 28, 2011 (PDF)

Supporting Documentation for Use of Macrophyte Data in Determining Lake Trophic Status - February 10, 2011 (PDF)

EPA Final Comments - February 18, 2011 (PDF)

Wingfield Response to Silva letter - February 23, 2011 (PDF)

Connecticut Water Quality Standards Approval - February 24, 2011 (PDF)

2009 Proposed Amendments to Connecticut's Water Quality Standards

Nutrients - Phosphorus Reduction Strategy

Temperature (future web page)

Water Quality Criteria (future web page)