South Sewer Treatment Plant
The City of Thibodaux's Sewage Treatment Plant is an innovative experimental plant using natural processes to treat sewage. In 1992 the plant was adapted so that adjacent wetlands could be used for tertiary treatment.
There are several features which make this plant a unique experiment. One is the recharging of a freshwater swamp with the effluent. This plant also uses ultraviolet light as a disinfectant, rather than chlorine. (See Louisiana Environmentalist July/August 1993 for an article on the Crowley, LA "Innovative Wastewater Treatment" which is similar to that in Thibodaux)
Effluent (liquid discharge) is released into a beautiful cypress-tupelo swamp for tertiary treatment during the final stage. This swamp had formerly been cut off from its supply of fresh water, and was in danger of dying. Now it is receiving fresh water from the sewage treatment plant and is thriving. Wetlands areas such as this act as biological filters for pollutants including nitrogen wastes from sewage pollutants and nutrients which are trapped in the soils where they are taken up by the roots of plants.