Drinking water saving potential of dual networks in Kuwait

Purpose - The purpose of this paper is to present a case study on how drinking water consumption could be potentially reduced by the introduction of dual water distribution networks. Since water of this quality is required only for drinking, cooking, bathing, and washing, delivering such water for uses that require non-drinking water quality represents a tremendous waste of water and energy, and contributes to environmental pollution. Design/methodology/approach - An overview of dual distribution networks in several countries is presented. Kuwait, in which 86 percent of the freshwater network has a parallel brackish water network, is the leader in this field, with brackish water used for a range of outdoor activities. The residential sector is the major consumer of freshwater in Kuwait and the control of demand in this sector will be a key factor in curbing the overall demand, which without any demand management measures is expected to quadruple by 2025. Computer modeling based on existing water use statistics and the proposed phasing-in of a dual distribution network for indoor use in households has been undertaken to determine how the large quantities of reclaimed can be used to reduce drinking water consumption. Findings - The paper presents a modeling exercise that demonstrates that by using reverse osmosis (RO) treated wastewater for toilet flushing and watering the gardens, water consumption demand can be stabilized at present levels over a 20-year period. Originality/value - The paper concludes that with foresight and long-term planning it is feasible to implement a dual water supply network in a major city, on a scale which may lead to saving up to 25 percent of drinking quality water on top of other traditional water conservation measures.