AbstractsEngineering

Storage of water for water quality control is one of the alternative means of achieving water quality objectives. Authorities in the field of water quality management disagree regarding the use of precious water for the dilution of wastes. The costs of achieving water quality objectives by treatment of wastes at their source or by a combination of waste treatment and storage of water for waste dilution are investigated. Water quality objectives studied are dissolved oxygen and coliform bacteria. Different levels of water quality and fluctuating flows of the Willamette River in Oregon during the 1963 summer low flow period are examined. To ascertain the minimum cost of achieving a water quality objective in a complex river basin, an analytical model is developed to examine the costs of waste treatment and the response of the receiving waters to the wastes discharged. A minimum cost solution to achieve a water quality objective is obtained employing nonlinear programming techniques which analyze the assimilative capacity of the receiving waters and the economics of waste treatment. The response of the receiving waters is indicated by systems analysis methods. Final results include the degree of treatment required of each discharger. Regulated flows under full development of the Willamette River Basin System of the Corps of Engineers do not follow typical statistical distributions. Distribution free or nonparametric methods are employed to determine the quantities of water required for low flow augmentation. Costs of storage are calculated on the basis of analysis of the costs of the three remaining authorized reservoirs in the Willamette Valley that are not under construction at this time. Conditions under which the storage of water for dilution is favorable, in lieu of waste treatment, are summarized. Generally water can be stored for water quality control in the Willamette River Basin to achieve high levels of quality by augmenting low flow levels of a short duration. Methods for selecting optimal water quality objectives and design periods for the storage of water for water quality control are presented in graphical form and expressed mathematically, These methods are based on the assumption that it is possible to measure the reduction in costs to society resulting from water quality management programs. This dissertation does not attempt to measure the reduction in damage costs because the data are not readily available at this time. An analytical model is used to illustrate the impact of different water quality management alternatives on the economy of a river basin in terms of waste treatment costs. This model produces some interesting results under different management policies to achieve the same water quality objective. The response of the receiving waters and the economic impact of stream standards and effluent standards are revealed by the model. Examination of the costs of different discharge policies indicates to the administrator the consequences of…