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County Manager's Office

Phone: 913-715-0725

111 S. Cherry St., Suite 3300, Olathe, KS 66061

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Tomahawk Creek Wastewater Treatment Facility Project

Tomahawk Creek Wastewater Treatment Facility construction site

Date Authorized: July 31, 2014 (project def.); May 5, 2016 (design); March 2, 2017 (pre-construction); March 29, 2018 (construction)

Project Authorization: $4,100,000 (project definition); $21,387,000 (design); $2,680,000 (preconstruction); $306,678,678 (construction funding including $23,131,462 (engineering construction services), $267,892,045 (Construction GMP, and bonds, PAF, and other project costs) Total Project Authorization = $334,990,678

Delivery Method: Construction Manager at Risk (CMAR)

Design Firm: Black & Veatch/HDR Engineers

Contractor: McCarthy Building Companies, Inc. (CMAR)

Completion Date (Estimated): March 1, 2022 (Substantial Completion)

Major Milestones: McCarthy anticipates that the slab of the BNR basin will be completely poured and finished by the week of 7/29/19. This structure is one of the largest and on the critical path so finishing the slab on-time is a significant accomplishment for the team. KCPL substation was originally scheduled for startup in September 2020, but is currently ahead of schedule with a startup in June 2020. Team is working to make the new Peak Flow Pump Station operational for wet weather treatment during construction by August 2020. This will allow McCarthy to begin work on the existing Influent Pump Station. McCarthy’s current schedule has them completing Lee Blvd improvements during 2019. Next contractual milestone is the liquids process contract milestone which is dated October 25, 2021. This will allow JCW to begin the process of eliminating flows to KCMO.

Future Pending Action(s): The Final Plat is on hold pending final approved design of WaterOne’s water main that will run parallel to Lee Blvd and is required for the project. The Chairman will need to sign the plat once the final design has been approved. The Board authorized the Chairman to sign the plat on March 29, 2018 under BS 18-13. The team is working on easements for WaterOne and KCPL distribution lines. It is anticipated that the easements will be presented to the Board in 2019.


  • McCarthy is currently on schedule and on budget despite the wet weather in May.
  • We are coordinating multiple site tours with County Commissioners, Leawood city officials, and guests in the beginning of September. 
  • We are coordinating with WaterOne and Leawood on the alignment of a larger water main along Lee Blvd to provide the increased potable and fire water needs of the facility. The new water main will replace the existing connection at Mission Road and will tie in at the east end of Lee Blvd near Leawood City Park.
  • The majority of work in progress includes earthwork, buried pipes and electrical utilities, piers, and concrete structures. Concrete foundations are being poured for multiple buildings and structures. Concrete wall pours have begun in five of the structures. Leakage testing is expected to begin on part of the BNR basin at the end of August.
  • McCarthy will continue early morning work hours for concrete pours. They have notified Leawood of this activity per the hours of operation memo of understanding and a notice has been placed on the website.

>> Project Website


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