COLUMBUS, GEORGIA WATER QUALITY PROGRAMS

The Columbus Water Works manages water resources and water reclamation for the Consolidated Government in Columbus, Georgia. The board-managed utility provides water for other cities and counties in Georgia and Alabama. Located in the Middle Chattahoochee River Watershed, the program has evolved over the last decade to include a 95 million combined sewer overflow (CSO) control program, riverfront re-development, environmental educational facilities and programs for demonstrating wet weather technologies and water quality protection.The CSO technology-testing program includes an array of side-by-side processes for optimizing solids separation and disinfection. The full-scale studies provide design methodologies and costeffective solutions for significantly reducing various contaminants in CSO's. Results include protocols for characterization and performance measurements, design methodologies for optimizing process components against target pollutant removals, operation and maintenance issues and procedures and quantification approach for yield reductions (mass per acre per year) and Total Maximum Daily Load (TMDL) strategies.Watershed monitoring and modeling included chemical, biological and physical measurements and use of the data to calibrate the EPA BASINS Model and to provide an overall assessment of watershed health and priority for watershed management. Watershed issues included source water protection of drinking water supplies and water quality to maintain and restore beneficial uses. Results include protocols for characterization, model calibration and watershed yield quantification.Overall program findings include load generation rates and yields for various pollutants correlated to watershed impervious area and aquatic biology indices. Loading rates between impervious collection systems (CSO) and erodible creek networks show exponential differences strongly suggesting cost-effective attenuation approaches to reduce annual pollutant quantities. CSO treatment demonstrations indicate high-rate compressed media filtration as a cost-effective technology that may also be applied to stormwater as an impervious area flush-control. Recommendations include a communications and monitoring network for drinking water protection and measurement of watershed progress and watershed demonstrations to develop long-term strategies for management policies and controls.The Columbus water quality program includes a peer review process by a team of volunteer experts, coordinated by the Water Environment Research Foundation. The peer review was undertaken to assure sound-science methodologies were applied to measure and model watershed parameters and to evaluate the performance of CSO technologies.