Powering the Future with a Wastewater Treatment Expansion

The City of Sioux Falls is making a significant investment in its future with the major expansion of its water reclamation facility. This $215 million project, the largest in the city's history, will increase the facility’s daily treatment capacity from 21 to 30 million gallons to support an additional 100,000 customers over the next two decades. As part of this critical infrastructure effort, Interstates is playing a key role in ensuring a smooth electrical transition and reliable power distribution. 

Navigating a Complex Expansion 

Interstates mobilized to the site in November 2021, handling a complete power distribution upgrade from 5kV to 15kV while keeping the plant fully operational at all times. This required extensive planning, coordination with city officials, and adherence to strict lockout/tagout procedures. “This was one of the project's main challenges and required temporary power, generators, and a ton of coordination with plant staff,” says Josh Wynstra, Project Manager, Construction, at Interstates. “Our site team has developed such a deep understanding of the facility’s power system that they now know it nearly as well as the plant staff themselves.” 

The upgrade will enhance the equipment’s long-term efficiency and reliability. “Upgrading from 5kV to 15kV results in future cost savings for the plant and increases capacity,” says Andy Van Voorst, Site Project Manager at Interstates. “The redundant power loops ensure continuous operation, preventing unexpected outages.” 

Innovative Solutions in 3D Modeling and Automation 

The use of 3D modeling and prefabrication benefited the project in several ways. “Virtual design and construction modeling helped us coordinate with other trades to prevent clashes, and our use of prefabrication greatly improved productivity,” Van Voorst explains. “Most of our brackets and supports were prefabricated, along with large conduit racks, which streamlined installation and minimized errors.” 

As part of the expansion, Interstates upgraded and integrated the facility’s automation system to ensure a seamless transition between existing operations and the newly added areas. “The client’s goal was to update the existing system while maintaining the same look and feel, and we also introduced new automation functionality to improve overall efficiency,” says Cary Bandstra, Automation Manager at Interstates. The upgraded system provides operators with enhanced visibility, allowing them to monitor the facility more effectively and make adjustments as needed. 

In addition to integrating automation across the facility, Interstates completed a full upgrade of the public works visualization platform. “We coordinated with the project schedule to implement the automation upgrade without delaying construction,” Bandstra says. These enhancements ensure that the facility operates with greater control and consistency, supporting Sioux Falls' long-term wastewater treatment needs. 

Strong Partnerships = Progress 

The success of a project of this scale depends on strong partnerships among contractors and city staff. “Having good collaboration has been critical to maintaining the project deadline and budget,” says Allyn Brummel, Civil Engineer for the City of Sioux Falls. “Interstates will play a critical role in the start-up of new facilities coming online over the next five months, and we look forward to continuing to work with them.” 

The project’s general contractor also praised Interstates’ contributions. “I was pleased with pretty much all aspects that Interstates brought to the project—from the Project Manager and Superintendent down to the craft doing the installation,” says Jay Robinson of McCarthy Construction. 

Looking Ahead 

With completion targeted for early 2025, the remaining work on this project includes finishing four buildings, construction closeout, and system start-up. As the project nears the finish line, the Interstates team remains focused on safety and quality execution. “We’re proud of the work done so far and are committed to finishing strong and injury-free,” Van Voorst says. 

Through careful planning, innovative solutions, and strong collaboration, Interstates is helping Sioux Falls build a more resilient and efficient wastewater treatment facility – one that will support the city’s growth for decades to come.