The Steuben Lakes Regional Waste District (SLRWD) embarked on a significant upgrade to its wastewater treatment plant (WWTP) with the design and installation of an effluent filter. Essentially, an effluent filter acts as a strainer, preventing large chunks of debris from passing through. This helps with WWTP effluent total suspended solids and effluent phosphorus removal efficiency for improved compliance with the SLRWD’s discharge permit regulations. The projects Engineering Design Phase began in early 2019 and saw the completion of construction in January 2021.

This initiative was crucial for addressing persistent issues with the aging effluent polishing pond, which had been operational since the early 2000s. The pond’s inefficiency in managing algae formation and solids settlement necessitated a modern solution to enhance the wastewater treatment process. The primary objective was to replace the outdated 2-million-gallon polishing pond with a more efficient tertiary cloth disk filtration system. This move was essential to mitigate algae formation issues and improve solids settlement and phosphorus precipitation.  

The project’s scope included several significant upgrades and installations. The existing polishing pond was dewatered and decommissioned, paving the way for the new filtration system. Installed within a new building on the existing WWTP site, this system is central to the upgraded treatment process. A new 77,000-gallon effluent equalization basin was constructed to buffer effluent flows from the existing Sequencing Batch Reactor (SBR) before filtration. Additionally, a poly-aluminum chloride (PAC) chemical feed system was added to enhance the treatment process, and upgrades were made to the plant site lift station to support the new system. The project incorporated Aqua-Aerobic Systems AquaDisk cloth media filters due to their compatibility with the existing SBR system, also manufactured by Aqua-AerobicSystems. These filters provide a significant improvement over the previous methods, offering more effective screening of residual suspended solids and phosphorus in a compact footprint. This efficiency enables better utilization of the WWTP site, as the new system occupies less space than the decommissioned polishing pond.

While the project did not increase the overall treatment capacity, it significantly improved the efficiency of removing suspended solids and phosphorus. This improvement aligns with current regulatory standards, resulting in fewer effluent Total Suspended Solids (TSS) and phosphorus violations.

The performance of the enhanced tertiary treatment directly benefits the receiving stream by reducing the environmental impact of the effluent waste stream. The new filtration system supports the long-term sustainability of the WWTP by freeing up space for potential future improvements on the site formerly occupied by the polishing pond. Moreover, the elimination of the polishing pond reduces long-term maintenance costs associated with dewatering sludge. Although the new disk filters require regular backwashing and cleaning, the process is largely automated, simplifying operation and maintenance.

One of the main challenges faced during the project was maintaining uninterrupted wastewater treatment service. Special permission from the Indiana Department of Environmental Management (IDEM) was required to bypass the existing polishing pond during construction, which temporarily increased effluent TSS and phosphorus levels. IDEM acknowledged this as a necessary step to achieve the project’s long-term goals. A key lesson learned was the advantage of designing pump stations with multiple pumps to handle varying flow rates efficiently. This approach allows large pump stations to manage wet well levels more effectively if they get too high.

This project represents a significant advancement in wastewater treatment for the Steuben Lakes Regional Waste District. With JPR’s guidance, the project not only addressed existing inefficiencies but also laid the foundation for a more sustainable and cost-effective operation in the longterm. The implementation of the effluent filter stands as a testament to the District’s commitment to environmental stewardship and regulatory compliance.

The project was funded through a State Revolving Fund (SRF) grant/loan package, ensuring financial support for the critical upgrades. JPR served as the design engineer, construction administrator, and Resident Project Representative (RPR) for this project. The team’s expertise ensured that the project was executed successfully from initial design through the Final Construction Phase.