CSO control project modifications based on water quality studies

A 5-year cooperative study of the Cumberland River at Nashville by consulti ng engineers, university researchers, Tennessee regulatory agency officials , federal agencies, and a citizens advisory committee produced results that allowed Nashville to alter its combined sewer overflow (CSO) control plan, eliminate two major detention tanks, and save $106,000,000. The data showe d that dissolved oxygen depletion was not a problem, nor was toxic material discharges. Fecal coliform bacteria were a problem, but it was short term and near field, and would not be solved by planned detention tanks, or even by eliminating all CSOs. Other changes are being implemented that will gre atly reduce CSO discharges at lower capital cost than the original plan.