What Happens After You Flush?

When the water (sewage) leaves your home or business it travels through a series of pipes and lift-stations to the Knox Wastewater Treatment Plant! The collection system consists of approximately 25 miles of gravity sewers ranging in size from 6" - 18". There are twelve duplex lift-stations located throughout the collection system that assists in transporting sewage to the City's Wastewater Treatment Plant for processing.

The City of Knox Wastewater Treatment Plant is a Class II extended aeration treatment facility that is designed to handle 0.7 MGD (million gallons per day) average design flow. The treatment facility is capable of handling up to 1.8 MGD of sewage during peak flow conditions. Processes at the facility include preliminary treatment, secondary treatment (activated sludge), final clarification, post-aeration, disinfection and sludge handling. These processes clean the sewage and allow treated water to be discharged to the Yellow River.

The Wastewater Department is responsible for the operation and maintenance of the City of Knox Wastewater Treatment Plant, as well as, the sanitary collection system. Laboratory analysis is performed five days per week with major testing completed three days. The wastewater staff members review the test results and make adjustments in the wastewater treatment process accordingly. Monthly operating reports are provided to the Indiana Department of Environmental Management (IDEM) and the Environmental Protection Agency (EPA) on a monthly basis as required in the City's National Pollutant Discharge Elimination System (NPDES) permit.