The City of Euclid is a partially combined storm and sanitary sewer community. The area served by the Euclid Wastewater Treatment Plant includes the Cities of Euclid, Willowick, Wickliffe, Willoughby Hills, Richmond Heights, South Euclid, and a portion of Cleveland. Over the past 20 years the City has faced new regulations and completed several projects to address SSOs, CSOs, and WWTP bypasses. Projects included various system rehabilitations and a 180 MGD wet weather treatment facility using swirl concentrator technology. While the technology was acceptable to EPA in the early 1990s, current regulations require secondary treatment of wet weather flow. The City was directed to sign a Consent Order schedule to implement improvements to upgrade bypass treatment and continue efforts to control remaining system CSOs and elimination of a number of SSOs.
System mapping and field investigations were used to evaluate the conditions of the collection system for building a SWMM model. Together with the flow monitoring data, the model was calibrated in order to provide a baseline hydraulic condition for the collection system, including all of the existing CSO and SSO locations. This baseline model was used through this investigation to predict flows within the system and at the WWTP in conjunction with a study of alternative capital improvements.
The study prepared contained a Long Term Control Plan (LTCP) for the control of system CSOs; a No Feasible Alternative (NFA) Report exploring alternatives for enhanced treatment of WWTP wet weather bypasses; and a Sanitary Sewer Evaluation Survey – SSO Elimination Plan (SSES-SSOEP) for system SSOs. The study also provided a sewer system Management, Operation and Maintenance (MOM) program and assessed coordinated implementation planning and affordability of the recommended courses of action. The comprehensive study provided a schedule of capital improvements for a 20 year implementation period.
Study challenges and constraint included limited available land at the WWTP. High rate treatment technologies investigated included various ballasted flocculation systems, high rate filtration, and chemical enhancement of swirl concentration. WWTP improvements were also reviewed to maximize secondary treatment including flow equalization, enhanced clarification, and membrane bioreactor conversion.