The Hammond Sanitary District submitted an application for a variance on August 28, 1996. The discharge from the Hammond Sanitary District facility is to the West Branch of the Grand Calumet River. The Hammond Sanitary District operates a Class IV, 37.8 MGD, single stage nitrification type activated sludge facility with high rate filtration through multimedia filters.
Disinfection is with chlorine and dechlorination is with sulfur dioxide.
Sludge is thickened, anaerobically digested, and dried with belt filter presses. Final sludge disposal is either by disposal in a landfill or land application. The plant is designed to treat wastewater prior to its discharge into the West Branch of the Grand Calumet River. The wastewater consists of treated domestic sewage, wastewater from industrial and commercial facilities, and storm water. The Sanitary District of Hammond submitted an application for a variance on August 28, 1996.