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Hartselle Utilities, Hartselle, AL

Hartselle Utilities won’t have to worry about a sludge build-up problem at its wastewater treatment plant in the future.

That problem was solved last week when HU began operating a centrifuge--purchased from & installed by Hydra Service, Inc. and produced by Peralisa Corporation in Italy--to extract solid matter from wastewater before it is processed and returned to Flint Creek.

The centrifuge is the centerpiece of a three-stage process HU began several months ago to keep sludge out of its holding ponds. While it doesn’t address the sludge already there, it has the capacity to reduce the weight of sludge in wastewater by a 16 to one ratio and thereby greatly reduces the cost of its disposal at the Decatur-Morgan County Landfill.

A 90,000-gallon glass-lined storage tank represents the project’s second stage. It is located adjacent to the building where the centrifuge is located and is used to hold wastewater before it is processed by the centrifuge. Polymers are mixed with the wastewater to accentuate the separation of solids from liquids.

The first stage of the project was completed last summer with the construction of drying beds, which are being used to separate sludge from pond water by allowing it to dry out under the rays of the sun. When the water dries out, the sludge is removed and hauled to the dump. The process is designed to remove all of the sludge from the ponds in time.

“This is going to extend the capacity and life of our wastewater treatment facilities and save ratepayers a lot of money in the long run,” said HU general manger Ferrell Vest. “It will also enable us to comply with state an federal environmental guidelines.”

Vest said the project was originally estimated to cost about $4 million.

“We decided we couldn’t afford that and began looking around for alternatives,” Vest pointed out. “So we broke it down and took it on one part at a time. At the same time we turned to our own staff for assistance.”

Jerry Johnson assumed the role of project manager; Glenn Partlow handled the engineering and Robert Wright served as superintendent. Others who played key roles were Scott Scales, Greg Knighten and Jason Summerford. The electric department installed the conduit for the centrifuge building.

“Thanks to their help and getting a good low bid on the centrifuge, we were able to hold the cost down to about $900,000,” Vest stated. “I couldn’t be any more pleased with the way the project turned out.”

   

    Hartselle Utilities staff and board members were joined by representatives of Peralisa Corporation and Hydra Service, Inc., last week to observe the operation of a Peralisa centrifuge at the Wastewater Treatment Plant last week. Peralisa, an Italian company, is the world’s largest manufacturer of centrifuges.