The public will soon be asked to weigh on a massive rebuild of the Tomahawk Creek Wastewater Treatment Facility next to Leawood City Park.
The project, which would begin in 2018 and take three and a half years to complete, will cost about $266 million and would bring the county-run treatment plant into line with tighter federal regulations on wastewater treatment.
No timetable has been set on what may be a series of public meetings on the construction project, but they will happen this month, county officials said. County and Leawood officials met recently to discuss plans for the treatment facility.
Changes in the Tomahawk Creek plant, 10701 Lee Blvd., have been on the table for the past few years because of how the county’s water treatment is intertwined with Kansas City’s. In 2010, Kansas City and federal regulators entered into a consent decree in which the city would fix problems with sewer overflow during wet weather.
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That affects Johnson County because the Tomahawk Creek plant can’t handle all the wastewater that comes through its watershed. The plant, which was built in 1955, treats up to 7 million gallons a day — or 40 percent of the total water flowing in. The other 60 percent goes to Kansas City to treat, making the county Kansas City’s largest customer.
Since the Kansas City system needs about $2.5 billion in upgrades, rates charged to all its customers, including Johnson County, have been going up. The county currently pays about $13 million a year to Kansas City for water treatment.
The county would have to make improvements in the Tomahawk Creek facility to continue using it at all because of tighter Environmental Protection Agency rules, said Tami Lorenzen, a county managing engineer in wastewater during a recent briefing with Leawood officials. The rules address removal of nitrogen, phosphorus and ammonia, nutrients that encourage algae growth and impair water quality. Those nutrients are toxic to aquatic life and have contributed to low oxygen content in some parts of the Gulf of Mexico, she said.
County officials have considered three options: Closing the Tomahawk Creek plant and sending all water to Kansas City; expanding the plant to handle up to 10 million gallons a day and sending the rest to Kansas City; or expanding to 19 million gallons a day, which is expected to handle everything in the watershed and end its use of the Kansas City treatment plant.
County staff has come to prefer the largest expansion, because officials say it allows the county to control its own destiny and would be less expensive to ratepayers in the long run than the other two options. Still, county residents should expect rate increases of 5.5 to 7.25 percent a year for the next 10 years. That covers all the wastewater capital improvement and operating costs.
It will be months more of planning before the project could become reality. The design will have to be refined and the project will have to go through the Leawood Planning Commission. And the county commission would have to give its OK for issuing the bonds.
The county will try to keep the construction footprint small, with the least impact possible on neighboring sports fields, Lorenzen told Leawood council members. Much of the plant would be demolished and rebuilt on the same site. The plant would be shut down completely during construction, to keep the building time short, and would work to maintain wooded areas nearby for screening, she said.
However, a construction staging area would be necessary and that might mean moving the kindergarten soccer fields to temporarily share with T-ball diamonds, she said. The construction also could mean some trail detours and temporary traffic detours as well.
County officials also assured Leawood council members that flooding would not be increased because of the construction and that odors would be controlled.
Council member Lou Rasmussen asked whether the outflow pipes would be more aesthetically pleasing once construction is done. “The outflow from the plant to the creek is not exactly the prettiest thing I’ve ever seen,” he said. “I’d like to suggest you might want to doll up that outflow area. Our main trail goes through there now and it’s really a disgrace.”
Leawood Mayor Peggy Dunn expressed displeasure about the disruption the construction will cause, saying she wished there was another alternative. “I guess in my mind I’m a little bit disappointed there couldn’t have been some agreement,” that would have left the area open for more park land while controlling water rates, she said.