Glendale Heights Wastewater Treatment Plant discharges treated water to the East Branch of the DuPage River in Illinois. Local discharge requirements state that the total suspended solids (TSS) discharging from the plant must be 5 mg/L or less. To remove TSS and meet this standard, Glendale Heights employed traveling bridge filters for tertiary treatment. Frequent problems with these filters included: bridge derailment, sand migration, inconsistency during high flows, and permanent biological fouling.
With an aging system, Glendale Heights needed to upgrade their tertiary treatment to continue to meet the TSS effluent standard. To minimize construction and operational costs, Glendale Heights established the design objective to use existing basins and maintain the current gravity fed system.