Johnson County Wastewater (JCW) optimized its capital improvement plan for the Mission Main and Turkey Creek collection system basins to identify millions of dollars in savings. The project completed by WCS Engineering and HDR in 2019 using OptimizerTM was driven by basement backups and sanitary sewer overflows (SSOs) in wet weather due to limited conveyance capacity in the existing collection system.
Conveyance, storage, and I/I reduction alternatives were evaluated to eliminate basement backups in the 10-year design storm and SSOs in the 5-year design storm. Objectives included minimizing life-cycle cost, integrating asset condition data, addressing risk by running sensitivity analyses, and providing flexibility for the plan to be adapted over time.
Once the capital improvement plan was optimized, the next task was to prioritize the implementation schedule. OptimizerTM was used to evaluate thousands of possible scheduling alternatives to determine the sequence that would maximize return on investment based on the following objectives (in order of priority: 1) reduce basement backups; 2) reduce manhole flooding; 3) reduce SSOs at Facility Protection Devices (FPD); and 4) reduce discharge at Peak Extraneous Flow Treatment Facility (PEFTF / High Rate Treatment).