Aerators, left, and ultraviolet treatment equipment are seen in the new Monteagle, Tenn., wastewater treatment plant.Officials are still trying to determine exactly what went wrong Sept. 18 to cause thousands of gallons of wastewater to flow backward into the basement of Monteagle, Tenn.'s new multimillion-dollar sewer plant.
Mayor Marilyn Campbell-Nixon said Wednesday that plant officials are no longer "manually treating" incoming wastewater but using a different process. It doesn't incorporate ultraviolet treatment equipment that was damaged by corrosive wastewater.
The cause of the malfunction and who has responsibility for fixing it must still be determined, though repair work a is "moving forward," Nixon said.
She said officials hope the plant will be back to normal, "pre-failure" conditions in 60 to 70 days.
Tennessee Department of Environment and Conservation officials say Monteagle's plant operators were not at fault, so Nixon believes the city won't have to pay to fix whatever malfunctioned.
The town's insurance carrier gave the green light to order replacement parts for some of the equipment in the basement, officials said.
Until new UV equipment is installed, wastewater is being treated by first chlorinating, then de-chlorinating the incoming flow, officials said.
Wastewater Treatment Plant 3 answered a seven-year sewer moratorium imposed by TDEC in 2005 after violations found between 2002 and 2004, state officials said.
In March 2009, a 50-year-old storage tank at Plant 1 collapsed. It spilled more than 150,000 gallons of raw sewage into Juanita Creek, dramatically illustrating the sewage system's condition and spurring work on the new facility.
State officials said in September that "backflow-preventer valves" and a sump pump operating in the basement could allow sewage to enter the basement under the right conditions.
State officials are satisfied with Monteagle's efforts, TDEC spokeswoman Meg Lockhart said Wednesday.
"Monteagle has worked around the clock to assure human health and the environment are protected," Lockhart said.