City of Emporia, Kansas Emporia, Kansas, United States

Innovative infrastructure reuse and uninterrupted plant operations

Major improvements for today and beyond

Through progressive design-build delivery, CAS Constructors, an Alberici Enterprise, implemented major improvements at the City of Emporia’s wastewater treatment plant. This project allows the plant to meet new discharge limits for nitrogen and phosphorous and will support the City’s anticipated growth for the next 30 years. The updated facility handles peak wet weather treatment flow of 11 MGD, streamlines operations and solids handling, and reduces energy costs.

Innovative reuse of existing infrastructure

To meet the City’s strict municipal budget, a CAS joint venture offered a cost-saving and creative approach that reused much of the existing facility. The team installed an Integrated Fixed-Film Activated Sludge (IFAS) process in the existing aeration basin, eliminating the need to build separate anaerobic/anoxic basins for nutrient reduction.

Plantwide system upgrades

Overall treatment facility improvements included the replacement of influent pumps and the installation of new headworks fine screening, washer-compactor, and grit removal systems. Additionally, the team converted the existing aeration basins to IFAS BNR basins, with anaerobic, anoxic, aerobic, and deoxidation zones. The project team installed new large bubble mixing and high-speed turbo blower systems to support the IFAS system, and final clarifiers and UV disinfection systems were all rehabilitated and replaced. The project also included the addition of a new aerobic digester, waste activated sludge (WAS) solids thickening systems, and a new process building which includes return activated sludge (RAS) and WAS pump systems along with chemical feed systems and storage. A new, plant-wide electrical system was also installed. The project also included construction of new laboratory, office, and administrative space.

No disruptions to operational plant during construction

This facility is Emporia’s only wastewater treatment plant. In order to keep the plant operational, the project team coordinated closely with plant operations staff. The team created and executed transition plans for each system to ensure the facility was able to handle influent flow and meet the water treatment regulatory requirements without disruption. For every phase of construction, the project team analyzed risks and prepared back-up plans to guarantee that the City’s wastewater treatment requirements were maintained.