De Soto Water Treatment Plant Expansion

De Soto Water Treatment Plant Expansion
Supporting Economic Development in Booming Kansas Community
Facing increased demand from growth — including a new Panasonic production facility — the City needed to restore capacity at its existing plant. HDR was hired to perform a rapid condition assessment and recommend improvements of the aging infrastructure.
The water treatment plant (WTP), located at the former Sunflower Army Ammunition Plant, was built in 1941 by the U.S. government for drinking and production water. After the facility closed in 1993, the plant was granted to the City and operated as a public drinking water supply. Originally designed to produce 8 million gallons per day (MGD), due to the facility's age, capacity was limited to 4 MGD.
The design started in early 2023, with Panasonic’s target for water production by spring/summer 2025. To manage the schedule, our team recommended using the Construction Manager at Risk (CMAR) approach and onboarding a contractor early in the process to provide input during design. Through a competitive process, the City chose Garney Construction to serve as CMAR.
To minimize risks with construction phasing and uninterrupted operations at the WTP, Garney proposed an innovative solution: building a new plant rather than rehabilitating — all while maintaining budget and schedule. In response, our team pivoted the design scope to a new filter and chemical building, transfer pump station, clear wells, and high-service pump station.
The project was delivered through three guaranteed maximum price packages: lime feed and clarifier equipment, process and major electrical equipment, and balance of plant construction. Substantial completion was split into two milestones: Milestone 1 was achieved in May 2025, meeting the City and Panasonic’s demand for resilience. This included placing online key plant components commissioned to their full capacity. Milestone 2, involving a third redundant clarifier and lagoons, is expected by October 2025, with completion in November 2025.
This work exemplifies the power of early collaboration and innovative thinking between project stakeholders to deliver a complex project on time and within budget, supporting significant economic development and growth.
