The Johnson County Commission has unanimously green-lighted a massive rebuild of the Tomahawk Wastewater Treatment Facility near Leawood City Park. The project is intended to control the costs of meeting stricter environmental standards.
Commissioners told wastewater staffers to proceed with the permits and get their documents in order for a May 5 vote to fund the plant’s design, which is estimated at $18 million to $20 million of the project’s total $280 million cost.
The vote last week signaled the commission’s intent to go ahead with the project, which they’ve been studying since 2006. Commissioners have spent the last year and a half deciding what action to take on the aging plant, which was built in 1955. Doing nothing is not an option, commissioners have said.
Johnson County customers can expect annual rate increases of 5 percent to 7 percent from 2016-2024 with the addition of the building project. For the person who pays $420 a year, the cost would go up by about $24 each year, according to wastewater department estimates.
That revenue would go to operating and capital costs for the whole wastewater system, though. Wastewater General Manager John O’Neil said the department did not have figures on how much of that increase the Tomahawk project would be responsible for.
The Tomahawk plant at 10701 Lee Blvd. can treat only about 40 percent of the water that flows to it. The county sends the rest to Kansas City for a fee, making Johnson County Kansas City’s largest customer. With a rebuilt treatment facility, Johnson County would no longer send wastewater to Kansas City.
In 2010, Kansas City and federal regulators entered into a consent decree requiring Kansas City to make major improvements to handle its water treatment during wet weather overflow periods. Those improvements have driven up the rates Kansas City charges its customers, including Johnson County.
Even without the Kansas City rate increases, the county would have had to do something about the plant. Tomahawk’s components from the 1960s were not capable of meeting the clean water standards of today, said Tami Lorenzen, managing engineer on the project.
The stricter standards by the federal Environmental Protection Agency are intended to clear excess nitrogen, phosphorous and ammonia, among other things, from the water. Those nutrients work the same way in the water supply as they do in fertilizer, she said, encouraging algae blooms that rob the waterways and later the ocean of oxygen and are toxic to aquatic life.
Commissioners looked at three basic options. They could have made moderate expansions to the plant and continued to send some wastewater to Kansas City or they could have shut down the Tomahawk plant altogether and sent all the water to Kansas City. Ultimately they ruled those options out because of studies that showed they would have been more costly to ratepayers in the long run.
The commission decided on the largest building project — a 19-million-gallon-per-day plant that will mean tearing down a lot of the current facility and rebuilding in roughly the same footprint. The plant will shut completely down during the first phase and send the entire flow to Kansas City.
Traffic will have to be rerouted near the project, but officials haven’t worked those changes out yet. However, federal regulators will not require the county to build storage tanks to handle wet-weather overflow, so the youth soccer fields will be able to remain.
The commission and wastewater officials have pledged to keep the trees screening the facility from the park as thick as possible. Wastewater officials also said they would keep construction time as short as they could. Construction is still expected to run from mid 2018 to 2021.
Roxie Hammill: email@example.com