CSO Control Project Modifications Based on Water Quality Studies

Abstract

A 5-year cooperative study of the Cumberland River at Nashville by consulting 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 showed 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 greatly reduce CSO discharges at lower capital cost than the original plan.