WILTON — A broken shaft in machinery designed to remove pollutants from wastewater before it is discharged will cost the Wastewater Treatment Plant at least $20,000 to repair.

And the repair would be temporary.

The broken shaft will be replaced through a second-phase renovation next year, Superintendent Clayton Putnam told the Board of Selectmen on Tuesday. During the renovation of the plant, built in 1978, two rotating biological contactors, known as RBCs, were expected to be replaced and two more added for a total of six, he said.

The broken shaft supports an RBC installed in 2003, he said. The RBC method now includes four large drums which revolve to remove grit and solids. The RBC drum normally weighs about 16,000 pounds, he said.

Options for dealing with the RBC include a $20,000 to $30,000 repair, a $40,000 to $45,000 modification or doing nothing over the winter until the replacement is installed during the renovation, Putnam said.

If nothing is done and another shaft goes, the plant would be in willful violation of state rules. Potential fines could be higher than the repair, Putnam said. 

The modification option is more expensive and means each new sprocket or piece of equipment for it would have to be modified, he said.

The current plan is to repair the shaft.

An outfit in Auburn could do the repair, Putnam said. The department only needs about a year and a half more of use from it. Funds for the repair will be taken from the department’s maintenance operation account.

“Sounds like a $20,000 Band-Aid,” Board of Selectmen Chairman Scott Taylor said.

The real blessing is that if this had happened after the renovation bids had gone out, it wouldn’t have been part of the project. “We would have had to increase the design and costs,” Putnam said.

All six RBCs will be included in the project at a cost of about $600,000, he said. The two bought in 2003 cost $96,000. The price for one is now $100,000, he said.

abryant@sunjournal.com