Seattle Public Utilities (SPU) has a complex wastewater collection system, comprising a network of approximately 1,420 miles of pipes, 68 pump stations, and 86 permitted combined sewer overflow outfalls. Major project drivers were old and deteriorating infrastructure, aggressive growth, and anticipated future land use changes. SPU hired Aqualyze, now a part of the Murraysmith team, to complete a comprehensive capacity analysis of the entire wastewater collection system.
To fulfil the project goals, our team conducted a system-wide modeling analysis under various design storms to select the performance thresholds in achieving performance goals, ultimately identifying high-priority areas by utilizing modeling results and other key metrics. To continue assisting future efforts, summary sheets for each priority area were developed that include relevant planning and analysis information.