CT Sewage Right-to-Know

In 2012 the State of CT passed the first Sewage Right-to-Know law (SRTK) requiring DEEP to post the locations of combined sewer overflows (CSOs) and to begin posting unanticipated sewage spills on DEEP's website starting in July 2014.  In 2018, the law was updated to require municipalities with Publicly Owned Treatment Works (POTWs) and Publicly Owned Sewer Systems (POSSs) to notify DEEP no later than two hours after discovery of an untreated or partially treated sewage discharge electronically.  The law also required operators to notify the chief elected official (CEO) of any spills occurring in their municipality that exceeded five thousand gallons or that is anticipated to exceed five thousand gallons.  The CEO, as soon as practicable after receiving any such notification, was required to inform the public and downstream public officials, as appropriate.

The law was updated again in 2021 by Public Act 21-42 which will be memorialized in the Connecticut General Statues § 22a-424a.  The updated language includes requirements for updating the electronic bypass system every 24-hours that a spill is on-going, requires DEEP to implement a real-time public notification system, requires DEEP to post an annual report by February 1 each year and changed the municipality reporting requirements.  The new language reads: "...not later than two hours after becoming aware of any sewage spill or permitted sewage bypass that reaches a water body or may come in contact with the general public, the operator of a sewage treatment plant or collection system shall notify the chief elected official, or such official's designee, and the local public health official of the municipality where the sewage spill or permitted sewage bypass occurred and the chief elected official, or such official's designee, and the local public health official of any municipality that may be potentially impacted downstream by such spill or sewage bypass. As soon as practicable, but not later than two hours after receipt of any such notice pursuant to this subdivision, each such chief elected official, in conjunction with the local public health official, shall inform the public of any sewage spill or permitted sewage bypass that has the potential to impact public health, safety or the environment. Any such information provided to the public may be provided through the use of social media and shall be provided in each predominant language spoken by the residents of such municipality."

DEEP Public Information 

Current information from December 1, 2021 forward may be viewed at the CT DEEP Performance Dashboard

Historic information from July 1, 2016 to December 1, 2021 may be viewed at the Bypass and CSO Events Public Viewer

Public notifications may be viewed on the DEEP Twitter page CTSewerOverflows (@CTSewageSpills)

Why do untreated and partially treated sewage discharges occur?

Sewage that does not reach the treatment facility or is not fully treated may pollute waterbodies. Sewage may leave the system before being treated due to:

  • Weather (heavy rains or snowmelt)
  • Sewer system blockages
  • Insufficient system capacity
  • Structural, mechanical or electrical failures
  • Collapsed or broken sewer pipes
  • Vandalism

Additionally, the older a collection system is, the more likely it is to experience sewage discharges.

Avoid Recreation in Sewage Pollution 

Notifications of sewage discharges help the public avoid boating, fishing or swimming in waterbodies that may contain illness causing bacteria.  It does not take much rain to make a combined sewer system overflow.  Never recreate next to sign indicating that a combined sewer is nearby, especially during a storm.  For more information on combined sewers in CT, please visit Combined Sewer Overflows Right to Know

Data Caveats

  • All data is submitted by the POTWs and POSSs.
  • DEEP does not issue notifications about individual discharges, they are inputted by the reporters for each municipality.
  • The reports are being submitted by the municipalities in a short time frame after discovery of a discharge and specific details may not be known.
  • Data is estimated based on the existing systems, models, and personal knowledge of the sewer systems.
  • Data quality, especially volumes, is not checked by DEEP.
  • The program allows for zero duration, short durations and zero quantities for volume.
  • Addresses may not be entered by the municipalities in a way that allows the parts of the address to be separated nor with an exact location.
  • Multiple notifications may be sent for the same discharge since municipalities need to submit daily and termination reports for ongoing discharges.

2022 Annual Report (Due February 1, 2022)

The 2022 Annual Report covers the period of January 1, 2021 through December 31, 2021.  Please also see the 2022 SRTK Annual Report Overview for additional information.

The Annual Reporting Requirements under Public Act 21-42 are as follows:

A summary of the sewage spills that occurred within each municipality during such year.

A summary of sewage spills that reached named or identified water bodies.

  • The 2022 Annual Report contains the summary "sewage spills" that reached named or identified waters.

A summary of the total volume of each category of sewage spill.

Any enforcement actions taken by the department related to such sewage spills. 

  • No specific enforcement regarding the attached reports has been taken as of this time. 
  • Some enforcement that includes steps to prevent spills may be present in other enforcement actions taken, such as CMOM enforcement while those involving CSOs would be contained in Long-Term Control Plan enforcement.



Content Last Updated: March 1, 2022