An economic analysis of selected strategies for dissolved oxygen management: Chattahoochee River, Georgia

Using the Chattahoochee River as an example, a method for evaluating the cost-effectiveness of alternative strategies for dissolved oxygen (DO) management is demonstrated. The conceptual framework for the analysis is suggested by the economic theory of production. The minimum flow of the River and the percentage of the total waste inflow receiving nitrification are considered to be two variable inputs to be used in the production of a given minimum concentration of DO in the River. Each of the inputs has a cost: the loss of dependable peak hydroelectric generating capacity at Buford Dam associated with flow augmentation and the cost associated with nitrification of wastes. The least-cost combination of minimum flow and waste treatment to achieve a prescribed minimum DO concentration is identified.

Results indicate that, in some instances, the waste assimilative capacity of the Chattahoochee River can be substituted for increased waste treatment with the associated savings in waste treatment costs more than offsetting the benefits foregone due to the loss of peak generating capacity at Buford Dam. The sensitivity of the results to the estimates of the cost of replacing peak generating capacity is examined. It is also demonstrated that a flexible approach to the management of DO in the Chattahoochee River may be much more cost-effective than a more rigid, institutional approach wherein constraints are placed on the flow of the River and/or waste treatment practices.