Rushville Installs AquaStorm® Cloth Media Filters To Treat Combined Sewer Overflow Discharge Instead Of Conventional Wet Weather Storage Tank

Faced with a consent order to eliminate untreated combined sewer overflows (CSOs) polluting Indiana’s Flatrock River, the City of Rushville took an innovative approach. Rather than installing a costly stormwater storage tank, city leaders partnered with Aqua-Aerobic Systems to pilot the AquaStorm® Cloth Media Filter—an advanced, compact solution that treats both wet and dry weather flows.

The pilot’s success led to the installation of two 14-disk AquaStorm filters retrofitted into existing sand filter structures, saving Rushville approximately $1 million in capital costs. These filters, coupled with alum coagulant dosing, delivered consistent high-quality effluent, achieving impressive reductions in CBOD₅, TSS, ammonia, and phosphorus even during peak wet weather events. With an average dry weather design flow of 1 MGD and the ability to handle up to 12.6 MGD during storms, the system also eliminated overflows from the outset.

Complementing the upgrade was a switch from chlorine to UV disinfection, further improving environmental performance while repurposing existing infrastructure for cost savings. Completed five years ahead of regulatory deadlines, this project marked the first U.S. installation of AquaStorm for dual tertiary and wet weather treatment—preventing an estimated 50 million gallons of raw sewage from reaching the river annually.