County marks start of massive $335 million Tomahawk Creek Treatment Facility expansion in Leawood

County and city leaders marked the groundbreaking of the $335 million wastewater treatment facility expansion. Photo credit Johnson County.

County and city officials on Thursday marked the start of a $335 million project that Johnson County Wastewater says will ultimately save ratepayers in the area large sums.

The county has been working with city, state and federal governments on the idea of the expansion of the Tomahawk Creek Wastewater Treatment Facility for several years now. The facility, located at 10701 Lee Boulevard near Leawood City Park, treats wastewater flows for parts of Leawood, Overland Park and Prairie Village, among other cities. However, because of capacity issues, Johnson County Wastewater has to divert much of the flows that come in to facilities in Kansas City, Mo.

“Currently, the county sends 60 percent of the Tomahawk Creek incoming flow to Kansas City, Missouri, for treatment and we treat the other 40 percent,” said Johnson County Wastewater General Manager Susan Pekarek. “The expansion will allow the county to treat all of its wastewater for that location and save ratepayers hundreds of millions of dollars in the decades ahead.”

The county estimates that when completed at the end of 2021, the new facility will save Johnson County Wastewater ratepayers $16 million a year with greater saving expected in the years that follow.

Johnson County Commission Chair Ed Eilert said that there are additional benefits, as well.

“New technology used in the treatment of wastewater flow will allow Johnson County Wastewater to meet higher environmental standards,” Eilert said.

During the construction period, the county will be diverting all of the flows that would have been treated at the Tomahawk Creek facility to Kansas City, Mo.’s treatment operations. Over the next two month, crews will be working to decommission and demolish the existing plant, prepare the site for the new facilities, and fence off the construction area. Future phases of the project will likely include road and trail closures in the Leawood Park area.

Here’s a video rendering that shows the existing facility and how it will be transformed:

A rendering of the project plan for the expanded Tomahawk Creek facility.