Aquifer storage and recovery of treated sewage effluent in the middle east

Treated sewage effluent (TSE) is becoming a critical resource in arid parts of the world. The high costs of desalinated potablewater and the depletion of fresh groundwater resources necessitate increased use of TSE as an important component of water resource management throughout the Middle East. TSE can replace potable-quality water in irrigation, with the latter becoming too valuable a resource to use for irrigation purposes. In urban regions of theMiddle East and North Africa, excess TSE is often available because of seasonal variations in demand and supply or that the development of reuse infrastructure has not kept pace with population growth, concomitant water use and TSE generation. Aquifer storage and recovery (ASR) technology provides an opportunity to store large volumes of TSE for later beneficial use. Natural attenuation processes that occur during underground storage in an ASR system can also act to improve the quality of stored water and thus provide an opportunity to 'polish' already high-quality TSE. Aquifers containing brackish water or those depleted from over-pumping are present throughout much of the Middle East. These aquifers could potentially be used as storage zones for ASR systems. However, currently available hydrogeologic data are insufficient for assessment of potential system performance. Other key design issues are the selection of ASR system locations and storage zones so that TSE will not enter potable water supplies, and ensuring that the ASR systems will be readily integrated into existing or planned sewage treatment, TSE transmission and reuse infrastructure. © King Fahd University of Petroleum and Minerals 2010.