Shelbyville is one of 68 municipally-owned sewer systems in Tennessee that are under some type of order to bring their systems up to standards, the Chattanooga Times Free Press reports, based on data from the Tennessee Department of Environment and Conservation.

A report this spring by the Tennessee Advisory Commission on Intergovernmental Relations said many sewer lines are a half-century old and many systems have been surpassed by rapid population growth.

For example, the Hamilton County Water and Wastewater Treatment Authority in Chattanooga has now been told to make improvements. Also under notice are sewer systems for major urban areas like Knoxville, Nashville and Shelby County.

But Shelbyville Power, Water and Sewer manager David Crowell said this is nothing new. A two-year-old order for Shelbyville is being addressed, with the first phase already completed.

"We've been under a commissioner's order since November of 2005," Crowell said this morning. "We're meeting the requirements by building a new sewer plant."

Crowell added that the first phase of the improvement has already been completed with the construction of a biosolid building at a cost of $2 million.

The second and final stage of the project will be the design of a $25 million plant, which is capable of handling 6.5 million gallons of sewage a day.

The new wastewater treatment plant was given an environmental assessment and a "Finding of No Significant Impact" by TDEC last year.

Crowell added that the final designs for the plant would be submitted to the state for approval by September and following the state's OK, construction can begin.

The current facility has a capacity of 4.9 million gallons a day. It originally handled two million gallons when first constructed in 1957, but was upgraded and expanded extensively in 1977 to meet Environmental Protection Agency (EPA) Clean Water Act requirements.

It was expanded again in 1986 with no increase in design capacity. The sewer system entered into a letter of agreement with TDEC in 1991 to begin a sewer system rehabilitation program, and in late 2005, a Commissioner's Order was issued due to several permit violations.

The violations involved "biochemical oxygen demand limits, total suspended solids limits, fecal coliform limits and settleable solids minimum percent removal limits and overflows in the collection system," TDEC stated.

The Power Board has already voted to pay for the new facility through rate hikes to local utility customers. According to the TDEC report, the current sewer rate was increased by five percent to finance the project.

"The sewer rates will need to be increased by 5 percent in calendar years 2008 and 2009, and by 10 percent in calendar years 2010 and 2011," the environmental assessment reads. The total incremental annual cost for the sewer project would be $145.20, "which is approximately 0.42 percent of the current annual household median income" for Shelbyville.

The Shelbyville Power Board has already purchased 12 acres west of the current facility all the way down to Pencil Street for the facility. The new plant would be a three-year project and an improvement to the city's sewer system. The plant will be on the same site and will hopefully eliminate the Lane Parkway odor.

Shelbyville isn't the only town in the county with this problem. Bell Buckle is still awaiting word from the Tennessee Department of Environment and Conservation (TDEC) about getting a sewer moratorium lifted.

A director's order against the town from TDEC was issued in March of 2005 that prevents the town from installing any new sewer taps until problems with its waste water system have been corrected.

According to the state order, there were 61 instances of bypass overflow with the system in 2004, which allowed an estimated 1.6 million gallons of partially-treated wastewater to enter Bell Buckle Creek.

-- The Associated Press contributed to this report.