City preparing for mandated sewer work

Per the city of Tiffin's Ohio EPA mandated Long Term Control Plan (LTCP), the city must reduce the Combined Sewer Overflow (CSO) events to four events per typical year while also eliminating all future bypass events at the city's Waste Water Treatment Plant. The LTCP, which was approved in 2017, is a multi-phase plan with a compliance deadline of July 2040. The countermeasures for obtaining compliance identified within the plan include conveyance, storage, Waste Water Treatment Plant and inflow and infiltration reduction improvements. The total estimated cost for the improvements identified within the LTCP was roughly $82.4 million when calculated in 2015. In 2022, the city updated the total estimated LTCP implementation cost to reflect recent inflation and the actual year each project was proposed to be constructed. Additionally, the city included additional cost in the estimate for necessary maintenance to the sewer collection system within the project areas identified by the LTCP. Updated calculations estimated nearly $160 million for implementation. Addressing the necessary maintenance concerns simultaneously with the OEPA mandates promotes a "dig once" plan to ultimately reduce the future impact on projects restoration costs as well as the impact construction has on the city's residents and neighborhoods. To date, several sewer improvement projects have been completed on behalf of the city's former LTCP. Beginning in the early 2000's the city completed three phases of Combined Sewer Separation Projects within the northern and eastern portions of the city, as well as an Interceptor Improvement project along Rock Creek. To date, three projects have been completed to comply with the new CSO policy approach as established within the plan approved in 2017; Downtown Interceptor Sewer Project (Completed 2017), Water Pollution Control Center Expansion Project (Completed 2021) which substantially increased the capacity of the city's Waste Water Treatment Plant to 13 million gallons per day, Backflow Preventer Project (Completed 2023) which eliminated the intrusion of river water into several of the city's combined sewer overflows. Currently the city has several projects in different phases of implementation; Combined Sewer Basin 24 & 30 Inflow Reduction Project; presently in construction in the vicinity of Charlotte Street and Rebecca, Ann and Schonhardt Streets, Combined Sewer Basin 16 Inflow Reduction Project; currently progressing to the construction phase with OEPA mandated compliance by July 2025.EQ Basin Project; currently in the planning phase with mandated compliance by July 2026; Main Interceptor Project; currently in the planning phase with mandated compliance by July 2028. Benner Interceptor Project; currently in the planning phase with mandated compliance by July 2028 Combined Sewer Basins 9-13 & 15 Inflow Reduction Project; currently in the planning phase with mandated compliance by July 2029. Combined Sewer Basins 18, 19, 23, 33 & 37 Inflow Reduction Project is currently entering the planning phase in 2024. The 2017 LTCP is a front end loaded plan proposing significant combined sewer overflow reduction by 2030. The total estimated cost of the upcoming sewer work requiring to be completed by 2030 (EQ Basin, Main Interceptor, Benner Interceptor and CSO 9-13 & 15 Projects) is estimated to be $117 million. The city continues to be proactive reducing the cost burden the implementation of the LTCP has on its sewer customers. The city has partnered with Raftelis a financial consultant experienced with utility funds to develop a strategic implementation plan in regard to funding. To date, the city has obtained several below market rate long term loans including in excess of $5.7 million in principal forgiveness from the Water Pollution Control Loan Fund (WPCLF) for consulting and construction contracts associated with the LTCP projects. Via the planning phase of the EQ Basin Project, the city recently identified the potential for significant cost savings. Thus, the city has submitted a LTCP amendment to the Ohio EPA for review which would propose restructuring the city's plan to replace the proposed EQ Basin with an off-site High Rate Treatment Facility. This modification would also significantly reduce the scope of the proposed Main Interceptor Project.