• Collective Utility of Exchanging Treated Sewage Effluent for Irrigation and Mining Water

      Ko, Stephen C.; Duckstein, Lucien; Systems & Industrial Engineering, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      The concept of collective utility is applied to a case study of alternative water resource utilization by providing a basis for comparing alternative uses of resources from the viewpoint of aggregate welfare. The exchange of sewage effluent for groundwater used by irrigation farmers, and the exchange of sewage effluent for groundwater used by processing and milling miners in Tucson, Arizona, are given as examples. Reviewed are collective utility concepts, case problems, definitions of problems, formulation of the model, and marginal change of collective utility. The first case has a collective utility of $800,500-g, where g represents unquantifiable factors, such as the reduction in quality of living due to the odor if solid waste exchanges. The second case has a collective utility of $175,000. Since it is likely that g will be on the order of $1 million per year, the first exchange is preferable to the second.
    • Saline and Organic Water Pollution

      Bohn, Hinrich L.; Johnson, Gordon V.; Department of Soils, Water and Engineering, University of Arizona, Tucson, Arizona, 85721 (Arizona-Nevada Academy of Science, 1972-05-06)
      Better use and recycling of fresh water, which often recharges the oceans, would reduce man's disruption of nature to increase his supply of potable water. The global distribution of water, desalination, water reclamation and recycling, the roles of soils and plants in recycling and urban misuse of water are discussed. Man can increase his supply of food and good fresh water by recycling and nutrient balance, which imply living off his wastes. Intimate involvement of soils and plants in the production of fresh water and food is clear. Soils and plants should be equally involved in converting our waste water into potable water and useful nutrients. Numerous examples of how this may be done and how it is being done are presented.