Preventing sewer backups in western Lawrence will take a new basin, pump and sewer pipe -- and the $3 million needed to get the project under way, officials said.
A Paola contractor is ready to dig holes down to three stories deep, coat them with 4,900 tons of concrete and connect them into pumps and more than a half-mile of new sewer pipe so that heavy rains won't cause sewage backups in western Lawrence.
Tuesday night, Lawrence city commissioners are expected to hire Carruthers Construction Co. L.L.C., for nearly $3 million, to build a 3.75-million gallon sewage holding complex on 28 acres of city land in the Four Seasons area of southwest Lawrence.
The project is intended to relieve stress placed on the city's sewer system by Lawrence's booming western growth. Heavy rains can seep into existing sewer pipes, which could overload the system and push sewage back into homes and businesses.
Even if the complex's open overflow basin is used only once every two years -- such storms are thought to occur only once every 10 years -- the investment will be worth it, said Roger Coffey, the city's director of utilities.
Sewage backups, he notes, are not fun.
``We're trying to minimize or mitigate some of that from happening,'' Coffey said. ``We're giving that water someplace to go.''
The new 2.5 million-gallon basin will be connected to an existing 1.25 million-gallon covered basin at the site, just southeast of 26th Street and Crossgate Drive.
The project, which also includes below-ground pumps and a new sewer line, should allow sewers north and west of the complex to function properly for years, officials said.
The site includes room for future expansion, if necessary.
Contract saves $1.5 million
The project's $2.997 million price tag for construction came in 33 percent below its estimated $4.48 million, or enough to save Lawrence utilities customers an estimated $1.483 million.
``That's the frosting on the cake,'' Coffey said.
Commissioners are expected to approve the contract with Carruthers during the city's 6:35 p.m. meeting Tuesday at city hall, Sixth and Massachusetts.
The road to approval has been far from smooth.
Officials struggled to negotiate a land purchase from Douglas County and endured vocal criticism from property owners about the prospect of planting a open sewage pool in the ground within 600 yards of nearby homes.
The city's hired engineers, Black & Veatch of Kansas City, Mo., conducted several meetings with neighbors in an attempt to quell fears about noise, smell and declining property values. City commissioners agreed to design the basin so that it could handle a permanent roof in the future. And the county agreed to sell the land.
``It's gone through a lot of public review,'' said Rod Bremby, assistant city manager. ``We're just hoping to get on with it.''
Construction could being within four to six weeks, Bremby said. Engineers expect the work to take about two years.
Steve Phillips, a Black & Veatch partner who is serving as project manager, said the project would provide sufficient protection for nearby residents.
People living in the area or using a nearby bike path would see a chain-link fence surrounding the site. Walls of the basin itself will rise 4 or 5 feet out of the ground, so that the wastewater inside the 22-foot-deep pool will be out of view.
Once full the basin likely would be drained within a day, and then sprayed down with fire hoses to ensure that all residuals are removed before becoming an odor problem.
To further reduce the chance of odor problems, Phillips said, all sewage heading into the basin also will be injected with oxygen and treated with chemicals.
``We believe that those should be effective in reducing odors,'' Phillips said.
Even if the features turn out to be less effective than the community desires, city officials could take the next step and hire someone to put a roof on top of the basin. The project has been designed with that eventuality in mind.
-- Mark Fagan's phone message number is 832-7188. His e-mail address is email@example.com.