A $215-million project underway in Sioux Falls, S.D., is set to rehabilitate and expand the city’s 23-acre water reclamation plant as it looks to meet increased demand.

City officials say the project is the largest expansion to the Sioux Falls Regional Water Reclamation Plant since it was built in the 1980s. The work is aimed at increasing the plant’s daily capacity from 21 million gallons to 30 million gallons. 

The project team includes construction manager at-risk McCarthy Building Companies Inc., along with Sioux Falls-based Henry Carlson Construction, Carollo Engineers Inc. and the owner’s advisor, Integrated Delivery Solutions. 

Mark Perry, wastewater superintendent for Sioux Falls, said in a statement that the expansion is needed as the region has seen “tremendous population growth.” City officials project the population of Sioux Falls and other communities where it provides water service will grow from about 175,000 in 2016 to nearly 300,000 in 2036. 

“The plant rehabilitation and expansion project is a monumental undertaking,” Perry says. 

The plan includes construction of a headworks building where wastewater enters the facility, installation of generators and electrical system upgrades, the addition of three aeration basins and four final clarifier pools and the expansion of chlorine treatment areas with more storage tanks.

Work on the project started last May. A spokesperson for McCarthy says the contractors have completed all major excavations, totaling 70,000 cu yd of dirt. The team has also placed concrete for the lower level walls at the new headworks and placed about half of the concrete for the new aeration basin slabs. 

The project is scheduled to complete in 2025. 

Sioux Falls is funding the project with a grant from the American Rescue Plan Act and a low-interest loan from the U.S. Environmental Protection Agency via a state revolving fund program.