Moccasin Bend-2

Moccasin Bend Wastewater Treatment Facility

The City of Chattanooga, Tennessee owns and operates the Moccasin Bend Wastewater Treatment Facility in Hamilton County. In 1984 the plant upgraded from 40 MGD to 65 MGD, where future CTI personnel worked on the design for the new expansion with a construction cost of $63 million.

With rapid city expansion and a growing collection system, the 65 MGD capacity WWTP needed a major expansion to accommodate upgrades to the liquids and biosolids handling of the plant. Again, the CTI team was selected to study, design and provide construction services for the expansion. Secondary treatment plant capacity was increased to 140 MGD, with an additional wet-weather treatment capacity of 120 MGD, for a peak treatment capacity of 260 MGD.

Following a study, the City selected to upgrade the 20-year solids handling process to primary sludge using two-phased thermophilic-mesophilic digestion. The six existing anaerobic digester tanks were converted to temperature-phased anaerobic digestion, followed by dewatering utilizing high solids decanter centrifuges to produce a minimum 25% cake solid. The existing plate and frame filter press system was replaced to dewater waste activated sludge through a vacuum-assisted plate and frame drying system, producing a minimum 75% cake solid meeting Class A biosolids requirements. This project was completed in 2005 for a total construction cost of $60 million.

Throughout the years, upgrades and new technologies have been implemented at Moccasin Bend WWTP to ensure the facility continues to provide effective wastewater treatment for the residents of Chattanooga. CTI continues to have a strong, trusted relationship with the City.


Before CTI was a company, the Moccasin Bend WWTP was upgraded from 40MGD to 60MGD based on designs from engineers who would go on to form CTI Engineers in 1991



To account for a growing collections system, the plant was upgrades from 65MGD to 140MGD with a complete overhaul of the solids handling procedure



Manufactured in 1982, the high purity oxygen generation plant needed rehabilitation and maintenance. CTI rehabilitated the two turbo air compressors and the cryogenic oxygen generation plant and replaced all system controls



In order to improve the reliability of the detritor mechanisms, the structures had to be upgraded to prevent equipment failures while still keeping the 140 MGD plant fully operational