Westchester County SSO

Project:  Westchester County SSOs

Client:  Connecticut Fund for the Environment and Save the Sound

Location: Westchester County, New York

Services:  Wastewater Treatment/Sewer Systems; Litigation Support

Inflow and infiltration (I&I) from deteriorating pipes and manholes were causing excessive sewage flows in the sewer systems of a dozen municipalities (municipalities) in southeastern Westchester County (County) that discharged to the County-owned wastewater collection system and treatment plants.  As a result of excessive I&I, sanitary sewer overflows (SSOs) frequently occurred during rainstorms and discharged raw sewage to the environment.  Local waterways in the County and the Long Island Sound were being repeatedly polluted.  The nitrogen found in raw sewage was contributing to hypoxia (low oxygen), harmful algae blooms, fish and aquatic life die-offs, and loss of coastal marshes experienced by the Long Island Sound.

In 2015, Connecticut Fund for the Environment (CFE) and Save the Sound (STS) were preparing to sue the County and municipalities under the Clean Water Act (CWA) to compel them to make the repairs necessary to their collection systems to reduce I&I and upgrade their wastewater treatment plants to prevent SSOs from polluting the Long Island Sound.  In support of their planned litigation, CFE and STS turned to CEA Engineers and Kevin Draganchuk, P.E. for technical expertise.

CEA Engineers analyzed SSO reports and Wastewater Treatment Plant (WWTP) designs, operational data, and inspection reports to determine the influence of I&I on SSOs at several county owned WWTPs and in the municipalities’ sewer systems and to determine their impact to surface waters.  CEA Engineers prepared a technical report for CFE and STS with the results of its analyses in support of their citizen’s suit under the Clean Water Act.  CFE and STS has successfully negotiated Stipulated Orders (SO) with the municipalities requiring investigation and rehabilitation of their sewer systems to reduce I&I and protect the Long Island Sound.

CEA Engineers continues to provide CFE and STS technical settlement negotiation support and monitors the municipalities’ compliance with the SO through its review of Sanitary Sewer Evaluation Surveys (SSES), Capacity, Management, Operation and Maintenance (CMOM) Plans, and sewer system rehabilitation plans.