WWTP HistoryPrimary Treatment
Granite City began operation of its wastewater treatment facility in 1965. Designed to provide primary treatment of domestic and industrial wastewater with a 30% removal of Biochemical Oxygen Demand (BOD) and 60% removal of suspended solids (TSS). The design flow was 20 MGD with a peak capacity of 30 MGD.
The plant consisted of a mechanical bar screen, raw waste pumping station, Parshall flume, aerated grit chamber, four primary settling clarifiers, a sludge holding tank and two vacuum coil filters. De-watered sludge was hauled by truck and disposed of in landfills.
In 1975 secondary treatment, combined storm water overflow treatment, sludge incineration and additional sludge treatment processes were added to the treatment plant. Plant capacities were increased to an average daily design flow of 23 MGD with a peak capacity of 34.5 MGD. The addition of secondary treatment provided a minimum overall removal rate of 90% for both BOD and TSS.
The Granite City Regional Wastewater Treatment Plant became a regional facility when it began treating wastewater from the Village of Glen Carbon and the Madison County Special Service Area in 1987 and from the Lansdowne Service Area of the Metro East Sanitary District in 1988.
In order to accommodate regionalization certain improvements were necessary. A new grit chamber was constructed upstream from the pre-aeration tank to increase capacity and correct deficiencies in the previous system. The two traveling bridges on the secondary clarifiers were replaced with four lighter weight traveling bridges with improved pumping capacity. Two of the original vacuum coil filters were replaced with Wrinklepress belt filter presses and the laboratory was expanded to meet EPA requirements.