Norwalk Sewage Overflows

Norwalk’s Inner Harbor scored significantly worse than the Middle or Outer portions did in the 2019 Unified Water Study.

Location: Norwalk, CT | Status: Active

Summary: Save the Sound successfully advocated for CT Department of Energy and Environmental Protection (“DEEP”) to issue a decree requiring Norwalk to fix conditions leading to chronic raw sewage overflow from its collection system. Now we are in the process of tracking and documenting progress to ensure the decades overdue repairs happen on schedule.  

Poorly maintained sewage collection systems can fall into a state of disrepair that can result in chronic sewage spills, impacting the health of Connecticut residents and our shared environment. A review of Connecticut’s Sewage Right to Know database showed that the City of Norwalk has chronic bypasses, in which sewage is diverted from the treatment plant or collection system and discharged into bodies of water. Despite two recent administrative orders issued by the EPA in 2010 and 2017, these sewage bypasses continue to result in the discharge of raw sewage into the Norwalk River, Five Mile River, and Long Island Sound. In 2020, Norwalk reported two illegal bypasses; in 2021, Norwalk reported eight illegal bypasses; in 2022, Norwalk reported four illegal bypasses; in 2023, to date, Norwalk reported six bypasses. While some progress is being made in eliminating these bypasses, there are still unresolved issues of excess flow resulting in bypasses during storm events and failing sewer pipes that require urgent rehabilitation. 

Norwalk also relies on the use of a combined sewage overflow (CSO) outfall at its treatment plant when flows exceed plant capacity, which discharges partially treated sewage into Norwalk Harbor. Norwalk also operates an emergency outfall, again to accommodate excess flow, that discharges raw sewage into the Harbor. There needs to be a plan to address this excess flow and eliminate the use of these outfalls. 

Save the Sound is tracking compliance with the EPA’s orders to fix this problem, through discussions with Norwalk staff, EPA, and DEEP, and review of compliance deliverables. Save the Sound submitted comments on the renewal of Norwalk’s wastewater treatment plant permit and participated in a public informational hearing that we requested. As a result of our advocacy during the permit renewal proceedings, DEEP issued an order in May 2022 requiring the city to develop and implement the following: 

  • Plans to study and remove excess flow from the collection system within 5 years 
  • Eliminate an unpermitted emergency overflow outfall within 5 years 
  • Either provide primary treatment to a permitted sewage overflow outfall or eliminate use of that outfall within 10 years.  

These efforts will reduce the discharge of raw sewage into Norwalk’s waterways and should improve water quality in Norwalk Harbor. DEEP will also soon establish a Total Maximum Daily Load (TMDL), an enforceable plan to address water quality problems, for Norwalk’s polluted inner harbor. We successfully advocated for a requirement that Norwalk monitor the harbor to provide information for the upcoming TMDL. We’ll continue to push DEEP to move forward with the process and finally bring the inner Norwalk Harbor up to Clean Water Act standards. 

Latest Step: DEEP issued an order addressing Norwalk’s sewage collection system and excess sewage flows. Per this order, Norwalk submitted a Sanitary Sewer Collection System Master Plan (“Master Plan”) and Wastewater Treatment Facilities Plan (“Facilities Plan”) to DEEP, and Save the Sound submitted comments on these plans. 

Next Step: DEEP must finish its review of the Master Plan and Facilities Plan to ensure that Norwalk is complying with the issued requirements. Once DEEP approves these plans, Norwalk must promptly implement them. Save the Sound will continue to review Norwalk’s compliance with the Clean Water Act and DEEP’s imperatives for preventing sewage overflows, including any deliverables. Save the Sound will also ensure that the public is informed about these ongoing efforts. 

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Last Updated: September 26, 2024


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