An addition to Tyson Foods' wastewater treatment facility for its Shelbyville Poultry Complex is one of the items on the city's planning commission agenda next week.

The food giant is requesting site plan approval for combined additional coverage of 13,707 square feet for the treatment system upgrade at 901 West Jackson St.

In February 2007, Tennessee Department of Environment and Conservation (TDEC) issued a notice of violation to Tyson Foods' environmental office in Shelbyville, stating that the plant's sewage treatment facility discharged effluent into the Duck River with levels of ammonia greater than allowed by the plant's permit.

The planned upgrade is intended to meet new federal guidelines for Tyson's wastewater treatment plant, according to Meg Lockhart, deputy communications director for TDEC.

According to city planning director Kip Green, three different clarifying tanks are to be constructed at the site to clean the discharge from the chicken processing plant, especially ammonia.

Tyson's existing chemical room will be modified to accommodate the large tanks. One part of the addition is a 150 foot diameter anoxic reactor, where chemicals will equalize the water to be discharged.

Drawings also show a new jet pump and blower building as well as a new sludge return pump station, which will keep any contamination out of the water, and a new clarifier flow splitter tank.

"This is a much better layout and a much better system for protecting the environment," Green said.

After the planning commission approved the site plan, then Tyson can apply for state approval for the discharge into the Duck River. The entire project should take 14 months to complete, Green added, but that time frame could be "drastically reduced if everything goes perfectly well."

The violations occurred during September 2006 through January 2007, TDEC said. The amount of ammonia in effluent flowing from the plant in January 2007 was almost twice what's allowed.

Last month, a Dissolved Air Floation system was installed to separate grease and oil from the water that is discharged into the Duck River, according to Mike Ensley, division vice president for Tyson.

Also on next Thursday's agenda is a de-annexation request for 53 acres at 1976 Fairfield Pike made by Don and Alberta Tanner.

If the commission approves the de-annexation, it would impact surrounding properties since any property owner who wanted to be annexed into Shelbyville would have to adjacent to Shelbyville's current corporate limits, Green explained.

De-annexation of the land would affect seven to 10 other property owners who might desire annexation in the future for possible development, Green added.

The commission will also consider site preparation plan approval for a 50,000 square foot spec building pad to be located on Hawkins Drive requested by OPM Properties, owned by Owen P. Marsh.

A public hearing is also to be held concerning Shelbyville's new subdivision regulations before the commission meeting.