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Sewer plant expansion considered

LAWRENCEVILLE - On the heels of a six-year, $400 million expansion to the county's largest sewage plant, officials are considering a $250 million contract to expand a plant that treats sewer for most of southern Gwinnett County.

The $250 million construction-management-at-risk contract was approved Monday by the Water and Sewerage Authority. The Board of Commissioners will consider the matter today.

This is the first venture into construction-management-at-risk for the Gwinnett Department of Water Resources, which typically uses the more traditional design-build model. Gwinnett County government used the model to build its arena and expand the county jail.

"A smart project is going to partner all the parties," Water Resources Director Frank Stephens said of the process.

In it, the single contractor, Pizzagalli Construction Co., will work with the designers and the county to find cost reductions.

During the Hill plant expansion, three separate contracts were awarded, one of them to Pizzagalli, but the geography allowed the expansion to take place with little interference in the operation of the plant.

But for the Yellow River plant, which is off Tom Smith Road, crews will have to work on a smaller site to phase in the expansion while keeping the plant running.

Another benefit to the at-risk model is a cap of the county's price at $250 million.

According to Adam Minchey, a division director for engineering and construction, a cost estimate set the price of the Yellow River expansion at $186 million in 2004, but since then prices of materials, including cement and steel have sky-rocketed.

A more recent cost estimate came out at $305 million, but the amount was out of the county's price range.

So engineers with contractor Jordan Jones and Goulding have worked to cut the amount.

One solution, Minchey said, was to use a new kind of membrane filter, new technology that cuts down the price of concrete but that has been tested and proved reliable since the original study.

"We like to be leading edge, but not bleeding edge," Minchey said of using the technology while saving costs.

During Monday's Water and Sewerage Authority meeting, the board approved a $6 million bump to the $16.8 million contract with the engineering firm for the extra work. The Board of Commissioners must also vote on the change.

After the six-year construction project, the plant's capacity will grow from 14.5 million gallons per day to 22 million gallons per day. At that time, the county will close two smaller, less efficient plants.