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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

(Updated July 31, 2020)

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:

  • The Peak Flow Pump Station was the first structure to be completed, and it was placed in service on July 31, 2020. This will allow McCarthy to take the existing Influent Pump Station offline for rehabilitation.
  • The next contractual milestone is completing the liquids treatment process by October 25, 2021. This will allow Johnson County Wastewater (JCW) to begin reducing flow sent to Kansas City, Missouri.

Future Pending Action(s):

  • None.


  • Conducting work activities according to COVID-19 social distancing and safety recommendations continues to be a high priority for the team. McCarthy has continued their approach of following
  • CDC guidelines including but not limited to extra signage, handwashing stations, social distancing, face coverings, etc. to maintain a safe and productive work site.
  • McCarthy is currently on schedule and on budget.
  • The Admin Building is scheduled to be complete by the end of September 2020.
  • Construction is approximately 65% complete.
  • Approximately 98% complete with structural concrete.
  • Underground utilities are over 90% complete.
  • Masonry work is approximately 55% complete.
  • Leakage testing on water retaining structures is approximately 45% complete (22 out of 48 tests) and will continue through the year.
  • The majority of work in progress includes masonry, interior piping, mechanical work, plumbing, HVAC, installation of equipment, and finalizing the facility control system programming and
  • hardware.
  • We are beginning to see more equipment (e.g. pumps, screens, heat exchangers, etc.) arrive onsite. No significant delays to equipment at this time.
  • The replacement of the western portion of Lee Blvd is currently underway. The road is currently shut down and is scheduled to open by September 4th of 2020.
  • The team is posting information to Johnson County Facebook page and the project website (www.jcwtomahawk.com) about wastewater treatment at the Tomahawk Creek WWTF as part of a monthly educational outreach series. To date, 14 segments have been posted and 10 more willbe posted in the future.

Project Website


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