WASTE-WATER REUSE - REGIONAL AND ECONOMIC-CONSIDERATIONS

Wastewater treatment and disposal has become a major component of poli cy-making subject, because of growing awareness of environmental quali ty issues. Agricultural use of treated effluents helps to maintain env ironmental quality, and simultaneously furthers other national goals s uch as providing sustainable agriculture while preserving scarce water sources. Another advantage of irrigation with wastewater is the possi bility of decreasing the purification level and the derived treatment costs, thanks to the role of soil and crops in acting as a bio-filter. Also, using the nutrients available in wastewater may diminish fertil ization costs. The considerations for policy decision making include m any factors such as the level of purification, the location of agricul ture and the types of crops. The regional dimension is reflected in th e way the decision on where to convey the wastewater influences the ch oice of agricultural crops, the fate of aquifers and the related costs . For example, in Israel, wastewater treated in the center of the coun try may pollute the coastal aquifer, whereas conveying this wastewater to the south, where there is no active aquifer gives rise to increase d conveyance costs and loss of agriculture in the center. In this pape r a general methodology for environmental policy decision making in re lation to wastewater is developed and applied in an Israeli case study . (C) 1998 Elsevier Science B.V. All rights reserved.