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Phone: 913-715-8500

11811 S. Sunset Drive, Suite 2500, Olathe, Kansas 66061

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Engineering Public Projects: Tomahawk Creek Wastewater Treatment Facility Improvements

The Tomahawk Creek Wastewater Treatment Facility, located at 10701 Lee Boulevard in Leawood, was originally built in 1955. The facility treats wastewater from the Tomahawk Creek watershed, the Indian Creek watershed downstream of the Douglas L. Smith Middle Basin WWTF (Lower Indian Creek), and the Dykes Branch sub-watershed. Prior to construction, the Tomahawk WWTF treated 7 million gallons per day, which was 40 percent of the wastewater collected from parts of Leawood, Olathe, Overland Park and Prairie Village. The remaining 60 percent was sent to Kansas City, MO for treatment. Once construction is complete, the facility will treat all of the flow.

Current Status

Johnson County Wastewater is proceeding with the construction of the improvements to the Tomahawk Creek Wastewater Treatment Facility. This project utilizes an alternative delivery construction approach called Construction Manager at Risk, or CMAR. Groundbreaking occurred in April 2018 and the facility is scheduled to start treating flows in October 2021. More information about the construction activities, the individual processes at the treatment facility and more can be found at the project website: Tomahawk Creek Wastewater Treatment Facility Expansion Website

Project Definition Phase

The Project Definition Phase of the expansion focused on the following tasks: refining the previously recommended improvements, project costs, and schedule; developing a conceptual level site plan to support public outreach efforts and site permitting; and negotiating and finalizing a discharge permit for the new facilities. The results of this effort are summarized in the Preliminary Design Report.

Process Improvements Pre-Design Study

Several studies were prepared to determine the future of the Tomahawk Creek Wastewater Treatment Facility. The Pre-Design Study evaluated various treatment alternatives and capacity scenarios using the latest user rate information and regulatory perspectives. The study identified $280 million in investments to expand the facility to 19 MGD as the most beneficial alternative.

Tomahawk Creek Wastewater Treatment Facility Improvements Fact Sheet

Section 1: Executive Summary
Section 2: TM 1 - Basis of Analysis
Section 3: TM 2 - Alternatives Identification & Development
Section 4: TM 3 - Alternatives Selection - Dry Weather Treatment
Section 5: TM 4 - Wet Weather Flow Evaluation & Alternative Definition
Section 6: TM 5 - Wet Weather Flow Alternatives Selection
Section 7: TM 6 - Combined Dry & Wet Weather Alternative Selection

Public Outreach

The project team completed many public meetings for this project, including three open house meetings and multiple presentations to Leawood Planning Commission and City Council. A recommendation for the design phase of the project was presented to the Johnson County Board of County Commissioners (BOCC) on Mar. 31, 2016. At that time the BOCC directed JCW to execute the regulatory permit for the project and to bring forward an authorization for design of the recommended improvements. This design authorization was developed and the BOCC voted to approve funding on May 5, 2016.  The BOCC also voted to approve funding and selection of a Construction Manager at Risk (CMAR) team for pre-construction services and approved funding for construction. Please refer questions to 913-283-0107 or [email protected].


Media Coverage

Media coverage since start of construction may be found here: https://www.jcwtomahawk.com/in-the-news. Below are links to earlier media coverage of the project.

Tomahawk treatment plant takes step toward $280 million rebuild

Tomahawk Wastewater Treatment Facility gets green light from Johnson County Commission

New EPA guidelines to affect Tomahawk sewage treatment plant