Abstract Submission: Growth in JEA’s service area prompted the expansion of the Southwest Water Reclamation Facility. The project included a new headworks facility with a flow distribution structure that collects Return Activated Sludge (RAS) flow from four RAS pump stations and distributes flow over various weirs to seven Biological Nutrient Removal (BNR) tanks. A computational fluid dynamics (CFD) analysis was used to optimize the design with two primary objectives: evaluate RAS mixing within the headworks facility and predict total flow and RAS distribution between the seven BNR tanks. The CFD analysis required multi-phase and multi-species models to accurately predict flow distribution among the seven free-flowing weirs and predict mixing of individual RAS flow from four pump stations and the primary flow in the headworks facility. The results of the CFD analysis revealed preliminary design performance was less than desired, leading to further design development to achieve the desired performance in the final design. The analysis identified the need to mix the RAS flows in a separate mixing box structure upstream of the flow distribution structure. Construction of the new headworks is complete, and operations data will be presented to demonstrate performance and validate the CFD results.
