Kokomo Long-Term Control Plan Addendum No. 2 and Rate Analysis
The City of Kokomo is in the midst of improving their combined sewer system based on their LTCP. This project included preparation of Addendum No. 2 to the LTCP discussing alternative approaches to CSO reduction at multiple locations, including CSO 006. CSO 006 is one of Kokomo's most significant as it is their largest-volume CSO and the source of a majority of the system's problem CSOs. It is scheduled to be addressed over the next few years to create the largest positive changes to the system.
A review of the original recommended plan for CSO 006 led our team and the City to investigate innovative technologies to economically and effectively address the CSOs in this area. As an alternative to separating the combined sewer, we reviewed and pilot tested an advanced vortex technology for the city to determine effectiveness for achieving floatables control. The particular brand tested not only achieved effective floatables control but actually produced results similar to primary treatment. The vortex separation chamber screens floatables and solids and separates them from the water discharges out of the overflow. The vortex provides mixing and can act as a contact chamber for chemical disinfection if required. In contrast to conventional screening practices, this end-of-pipe treatment technology has been shown to be more efficient, occupying less than one quarter of the footprint and costing up to 50 percent less. The vortex technology is an integrated solution that offers low capital cost, no moving parts, no power or minimal power requirements, a small footprint, and minimal maintenance, which appealed to the City of Kokomo. Similar units have already been installed in Indiana. These can be sized for different flow rates, but are easily capable of treating more than 100 MGD with multiple units installed.