In southwestern Indiana, Bowen Engineering Corp. is proceeding with numerous upgrades to the Evansville Westside Wastewater Treatment Plant. Bowen Senior Project Engineer Homer Fruit says the $16-million project "will increase the capacity of the treatment plant from 20 million gallons a day to 40 million gallons a day."
The plant upgrades, designed by Bernardin, Lochmueller & Associates Inc. (BLA) and Clark Dietz Inc., include the addition of the first biofiltration process in Indiana. According to BLA, the biofiltration process consists of a submerged floating media, like polystyrene beads, where bacteria grows. Wastewater and air are introduced through the bottom of the media-filled tanks. As the wastewater flows up through the media, the bacteria breaks down the organic matter in the wastewater.
"The major portion of our project is installing the biological aerated filter," says Bowen Project Engineer Brian Meunier. "Biofilters are popular in Europe, but this is just the sixth one that has been built in the U.S."
Meunier says biofiltration "is a different kind of process than found on typical wastewater treatment plants." Biofiltration requires no additional settling tanks and no return sludge system. The backwash water, generated after cleaning the media, is easily transported to the head of the plant for treatments.
Bypassing The Headworks Building
To keep the wastewater treatment plant operational while making modifications to the plant, Bowen enlisted the services of ITT Water & Wastewater Indiana, LLC, located in Evansville, to provide a bypass around the headworks building. "ITT was involved with the project because we had to replace the influent and effluent pumps, which had been in service at the plant since 1955," Meunier says.
Headed by Branch Manager Jack Dutton, ITT Water & Wastewater, which offers a number of pumping product lines, provided three Thompson 16JSC electric-drive pumps with Emotron VFDs and controls for the bypass of the wastewater treatment project, according to Sales Representative Brad Coney.
"We set up three 18-inch pumps along with about 500 feet of 18-inch pipe for the bypass," Coney says.
A pressure transducer that was tied to the main control panel supplied the water level depth to the VFDs to control the speed of the pumps as the flow increased or decreased in the 60-inch line.
The contractor also wanted backup for this project as well as monitoring capabilities. So, ITT Water & Wastewater provided a 400-kilowatt generator with switch gear in case of power failure for stand-by power.
