Construction is set to begin next week on a $3 million sewage holding basin in southwest Lawrence.
It's time to start digging.
A Paola contractor is scheduled to start work next week on a $3 million project to boost capacity for Lawrence's 260 miles of sanitary sewers.
The project's largest component will be a giant hole -- known as a ``holding basin'' -- designed to hold up to 2.5 million gallons of overflow sewage during periods of heavy rain.
The concrete-lined basin will serve as a sanitary safety valve to protect basements from backing up in town. It will be large enough to hold the water of more then three Lawrence Aquatic Centers.
``That's a lot of water to put downstream into the system at one time,'' said Debbie Van Saun, the city's assistant director of utilities. ``This will hold it until that system has a chance to clear out. Then we can gradually release it.''
The project, which also includes installation of a new pump station and force main, will be built by Carrothers Construction Co. of Paola. Construction is expected to take at least 18 months.
The new complex, located on 28 acres just southeast of 26th Street and Crossgate Drive in southwest Lawrence, is intended to relieve pressure on the city's sewer system.
Instead of increasing the size of pipes downstream -- a time-consuming, disruptive and expensive process -- officials decided to install the basin to handle overflow during the heaviest rains. Officials expect the basin to fill up only on rare occasions, when the ground already is saturated and intense rains add to the load by flowing into the system through cracks in sewer pipes and holes in manholes.
Once the sewer load loosens up, typically within one or two days, officials then can release the basin's load into the system.
The new basin will have concrete walls about four or five feet above ground, surrounded by a perimeter fence. The walls will be strong enough to support a roof, if necessary, in the future.
Odor-control systems also will be included in the work, leaving only one likely time for unpleasant smells: immediately after the basin has been emptied. Officials hope to handle those problems with an aggressive cleaning program, including the use of fire hoses to power-wash basin walls.
-- Mark Fagan's phone message number is 832-7188. His e-mail address is firstname.lastname@example.org.