The Wastewater Treatment Plant 

The Wastewater Treatment Plant was established in 1946. To date, it has undergone several updates to accommodate the growing population and businesses. Currently, the design flow is 1.9 MGD (million gallons per day). The peak flow capacity is 3.0 MGD. The primary treatment removes grease, grit, and debris. The secondary treatment uses aeration to eliminate phosphorus and ammonia. From April 1 to October 31, the plant disinfects with sodium hypochlorite (bleach) to remove E. coli. The water is then treated with sodium bisulfite to dechlorinate before being discharged to the Berlin Court Ditch? During rain events, the plant can reach a flow of 5.0 MGD. We underwent a massive CSO (Combined Sewer Overflow) project in 2019 and constructed a Wet Weather Detention Facility to capture additional runoff from rain events.

Wet Weather Detention Facility

Once the flow enters the facility, it goes into 44 MG tank and through a bar screen to remove large debris . It is then pumped through 4 RCS (raw combined sewage) pumps that are rated at 2.5 MGD each. The water is treated with Ultraviolet light for disinfection before it travels into the Berlin Court Ditch.

Once a rain event is over and the flow at the WWTP returns to normal, the WWTF then begins to drain back to the WWTP.

When the WWTF is completely drained, residual sediment remains on the bottom of the storage tanks. These tanks are flushed with a tipping bucket system and each tipping bucket holds 1,000 gallons. There are 13 tipping buckets within the storage tank.

Lift Stations 

The City of Nappanee has 15 lift stations. These are small storage tanks with either pumps that are submerged in sewage or pumps that sit in a dry area and pump out of wet wells. They receive sewage from residents and businesses, then pump it to the wastewater treatment plant.

Maintenance technicians check certain stations daily and all stations once a week. They are periodically cleaned due to grease and trash buildup. A few times a week, the maintenance crew pulls pumps to clean them of trash.