The Board of Mayor and Aldermen Friday authorized City Clerk Walter Osborne to advertise for bids for a new reactor clarifier for the city’s water treatment plant on Haining Road.

The clarifier is one of two 47-year-old clarifiers installed at the plant in 1968 and used to soften the water during the treatment process, Public Works Director Garnet Van Norman said.

“It’s used to mix in the lime during the process,” he said. “As the lime slowly sinks to the bottom of the clarifier, it is sucked away.”

He said the clarifier, known as clarifier No. 1, has broken down.

“Its gear box is worn out and its old,” he said, adding the city has $2 million put aside for work.He said similar work on the other clarifier about two years ago cost $1.6 million.

“We’re hoping we’ll be able to get some low bids and save some money,” he said.

“This new system will have stainless steel equipment,” Van Norman added. “The equipment currently on the clarifier is made of mild steel and you had to turn off the system and break it down and clean the parts. With the new equipment, all you have to do is stop it and wash it down with a hose. That’s going to save us a lot of time.”

He said the new unit is expected to last 20 to 25 years.