DE SOTO, Kansas — The City of De Soto celebrated the opening of its expanded wastewater treatment plant with a ribbon-cutting ceremony. The plant began operations in March, and the ribbon-cutting recognized the completion of a project that doubles treatment capacity from 1.3 million gallons per day (MGD) to 2.6 MGD.

The expansion was driven by the arrival of a $4 billion Panasonic battery manufacturing facility, expected to bring 4,000 jobs to the area and help supply batteries for electric vehicles. To meet the plant’s startup requirements, the City needed to expand treatment capacity on an exceptionally tight schedule while also meeting increasingly stringent water-quality requirements for nitrogen and phosphorus removal.

“Expanding our wastewater treatment capacity is an investment in the long-term reliability of our community’s infrastructure,” says Rick Walker, mayor of the City of De Soto. “It gives residents and businesses confidence that the essential services they depend on are in place, well maintained, and prepared to meet De Soto’s needs for years to come.”

A joint venture of Burns & McDonnell and CAS Constructors delivered the $40 million expansion using progressive design-build. This approach enabled the team to reach 30% design in under six months and positioned the City to meet its aggressive schedule.

“Progressive design-build gives small communities a real advantage when they face big infrastructure challenges, because everyone is at the table early,” says Jeff Keller, manager of the project’s design team at Burns & McDonnell. “That collaboration let De Soto move faster, manage risk and keep costs in check without overextending its staff.”

The project team accelerated design and early procurement to support Panasonic’s startup schedule while implementing a combined chemical, physical and biological water treatment process. The team also coordinated closely with the Kansas Department of Health and Environment and Panasonic to define flows and meet permit requirements.

“Early procurement, strategically phased construction, and a relentless focus on safety let our team meet an aggressive schedule without compromise,” says Travis Stryker, PE, president of CAS Constructors. “Delivering this expansion on time made it possible for the City to meet Panasonic’s timeline.”

The expansion provides capacity for Panasonic’s initial operations while creating a foundation for future development throughout the region.

About the City of De Soto

Located in Johnson County, Kansas, De Soto is a community that balances its history and small-town charm with its growing role in the region. The City works to provide high-quality public services, invest in infrastructure, support economic development, and enhance quality of life for residents and businesses. Learn more at desotoks.us.

About Burns & McDonnell

Working from more than 75 offices around the world, Burns & McDonnell designs and builds critical infrastructure. Our family of companies, driven by engineers, construction professionals, architects, planners, technologists and scientists, delivers projects grounded in safety and a desire to make a difference as we make our clients successful. Founded in 1898, Burns & McDonnell is 100% employee-owned. Learn more.

About CAS Constructors

CAS Constructors (CAS) is a leading contractor specializing in the collaborative delivery of water and wastewater infrastructure projects throughout Kansas and the Midwest. Since 1985, CAS has safely completed more than 400 projects, strengthening critical water infrastructure that transforms communities and improves lives. CAS is headquartered in Topeka, Kansas, and is a subsidiary of Alberici, the 34th largest contractor in the United States (Engineering News-Record, 2025).