Day Pitney remains committed to providing quality legal counsel, while protecting our clients and employees, and transforming our communities into more just, equal and equitable spaces. For more information, please visit our COVID-19 Resource Center | Racial Justice and Equity Task Force.


Publications Events

The Connecticut Department of Energy and Environmental Protection Initiates Triennial Water Quality Standards Review, Requests Public Input

Publisher: Day Pitney Alert
March 8, 2019

The Connecticut Department of Energy and Environmental Protection (DEEP) announced this week it is initiating its triennial review of the Connecticut Water Quality Standards (WQS).

As a part of its review, DEEP is accepting public comments from March 4 through April 5. Comments should be submitted via email to During the public comment period, DEEP will conduct a public meeting on March 13, from 1:30-3:00 p.m. (snow date scheduled for March 15 from 1:30-3:00 p.m.) in the Gina McCarthy Auditorium at DEEP's headquarters located at 79 Elm Street, Hartford, CT.

The purpose of the triennial review, according to DEEP, is to evaluate the need to update or revise the WQS in order to remain consistent with state and federal law and to ensure that Connecticut's WQS continue to reflect the best available science and support sound water quality management policies. While DEEP is accepting comments on any provision of the WQS, areas already under consideration by DEEP as a result of the last triennial review conducted in 2014 include:

  • Updates to Numeric Water Quality Criteria: DEEP is proposing to review its existing numeric water quality criteria of the WQS against EPA's updated water quality criteria recommendations to determine whether to adopt the federally recommended criteria or to provide a reason for not doing so in accordance with Section 304(a) of the federal Clean Water Act. These updates to federal water quality criteria include recommendations for toxics, bacteria and ammonia.
  • Revising the Low Flow Statistic Applicable to Fresh Waters: DEEP is considering changing the low flow statistic applicable to fresh waters from the current 7Q10 flow to the Q99 flow. The Q99 flow represents the daily low flow rate that is expected to occur approximately 1 percent of the time. According to DEEP, Q99 flow information for water bodies in Connecticut is easily accessible for all locations and not just those served by gauging stations.
  • Extended Disinfection Period: DEEP is seeking an extension of the disinfection period of treated sewage discharge to surface waters for all sewage treatment plants located south of Interstate Highway I-95 to April 1 through November 1, unless an alternative schedule is approved. The current period is from May 1 to October 1.
  • Downstream Protection: The Clean Water Act requires consideration of the impacts of upstream activities on downstream waters when addressing water quality concerns. DEEP believes the current WQS adequately address this concept but may propose revisions to the regulations as may be needed to remain consistent with federal regulations.
  • Water Quality Classification Maps: DEEP is evaluating the need to revise current Water Quality Classification maps in order to reconcile water quality classification designations with shell fishing classifications for specific water quality segments. Additionally, DEEP expects to update groundwater classification designations for consistency with Aquifer Protection Areas.

Any changes to the WQS proposed as a result of the triennial review will be implemented through a formal regulatory process, which will also include opportunities for public review and comment.

Should you have any questions regarding the above, please feel free to contact any of the attorneys listed in the sidebar.

Related Professionals
Hartford, CT
T: (860) 275 0371
Hartford, CT
T: (860) 275 0357
Washington, DC
T: (202) 218 3918