Original Date: 04/22/1996
Revision Date: 01/18/2007

Moccasin Bend Wastewater Treatment Plant serves more than 220,000 residents and 102 industrial dischargers including Chattanooga and its surrounding communities. Typical loading is approximately 60 million gallons per day (GPD) and up to 220,000 pounds per day as biological oxygen demand; collection is complicated by the Tennessee River and the extreme and difficult topography. In 1976, when the Publicly Operated Treatment Works (POTW) was established, Chattanooga was eighth nationally in percent of its population engaged in manufacturing and 19th nationally in the diversity of its industrial base. Wastewater composition was therefore subject to frequent and rapid fluctuations.

To help alleviate these problems, the POTW first conducted special samplings to establish the characteristics of normal domestic wastes. It then worked with the Chattanooga Manufacturers' Association (CMA) to establish pretreatment standards which protected the POTW from upset while providing close and stable standards for industry. (Of 37 parameters established in 1976, only the silver parameter has changed.) These standards were accepted by EPA in 1982 – the first pretreatment standards accepted in the region.

Permits are now enforced through self-monitoring, random sampling, and on-site inspections by the POTW-budgeted staff of 121 which includes one pretreatment coordinator, one inspector, and three sampling technicians. Surcharges to industry provide $2M per year of the $30M per year operating budget.

The POTW includes two large aerated equalization basins (35 million gallons each) and a pure oxygen activated sludge digester. The sludge processing operations produce about 300 wet tons per day (five-day week basis) of Class B sludge for landfill disposal and limited land applications. An elaborate automated filter press provides filter cakes of >35% solids.

For more information see the Point of Contact for this survey.