Connecticut State Council on Environmental Quality

2024 CEQ Annual Report


Water


The Water of Long Island Sound               Warming and Rising Waters               Swimming               Clamming and Oystering               Drinking Water

Rivers, Lakes, and Estuaries

Climate Change Indicator

 

 

The Department of Energy and Environmental Protection (DEEP) assesses water quality for each designated use (aquatic life, recreation, and fish consumption) for some waterbodies in the state, which characterizes whether the water is suitable for that designated use. While there has been an increase in the number of river miles assessed, there has been a slight decrease in the percentage of assessed river miles that fully support aquatic life. In addition, there has been little change in the percentage of assessed lakes and estuaries that “fully support” aquatic life in recent years.33 Data for 2024 is delayed and there are no official results yet.

Goal: Section 101(a)(2) of the CWA (1972) established a national goal for “water quality which provides for the protection and propagation of fish, shellfish, and wildlife, and recreation in and on the water, wherever attainable”.
 
Combined sewer overflows (CSOs) are discharges of untreated sewage from combined sewer systems and sanitary sewer overflows (SSOs) are discharges of untreated sewage from separate sanitary sewers and are sometimes referred to as spills or bypasses. 


The occurrence of CSOs and SSOs increases when significant rainfall occurs, particularly from extreme weather events. During heavy rains, untreated stormwater and wastewater, which can contain pathogens, excess nutrients, and chemicals, may be discharged at CSO locations. The discharge of untreated or partially treated sewage can adversely impact water quality, which effects recreational and economic opportunities, such as swimming and shellfishing. As depicted in the chart, more than 1.2 billion gallons of CSO volume and over 800 million gallons of SSO volume were released to waterbodies in Connecticut in 2024.* Almost 82 percent of the total CSO volume released in 2024 was attributed to the Bridgeport West and Metropolitan District Commission (MDC) treatment facilities, while almost 80 percent of the total SSO volume released in 2024 was attributed to facilities in New Haven, Bridgeport, and West Hartford.34

 

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33 DEEP, 2022 Integrated Water Quality Report to Congress; portal.ct.gov/DEEP/Water/Water-Quality/Water-Quality-305b-Report-to-Congress.

34 DEEP, CT Sewage Right-to-Know webpage and CT DEEP Performance Dashboard, accessed 4-1-2025; portal.ct.gov/deep/municipal-wastewater/ct-sewage-right-to-know. Frequently Asked Questions about Combined Sewer Overflows (CSOs); portal.ct.gov/deep/municipal-wastewater/combined-sewer-overflows-frequently-asked-questions.