ABSTRACT
Groundwater resources in the Middle East are being used at unsustainable rates, as populations grow and water demands increase. Desalination is a critical source of potable water, especially in the GCC nations; however, this supply source is very energy intensive and costly. Surface water in the Middle East is rare. The only other water supply source of significance in the region is reclaimed water.
Reclaimed water use is increasing throughout the region. Uses of reclaimed water include irrigation and industrial use, saline intrusion barriers, and indirect potable reuse, generally in an unplanned manner. The authors discuss the stages of reclaimed water use from immature to mature, though optimization. During this optimization phase, the best uses of reclaimed water are given priority, as well as increased cost recovery applied through tariffs. As reclaimed water use nears 100%, Aquifer Storage and Recovery (ASR) can become an important element of reclaimed water use optimization, allowing supply to keep up with varying demand, and ensuring consistent supply to paying customers. ASR does not work in all hydrogeological or hydrochemical settings. Factors determining success or failure of below ground water storage of reclaimed water are explored, as well as water quality considerations.
Water quality concerns for reclaimed water are explored, including potential acute concerns (i.e., bacteriological exposure) and potential chronic concerns (e.g., heavy metals and contaminants of emerging concern, or CECs). Potential contaminant migration and attenuation mechanisms associated with reclaimed water in the subsurface are discussed.
Proper use of reclaimed water includes application of the multiple barriers principal to ensure protection of public health and the environment. Multiple barriers can come in the form of various treatment trains, and separation of reclaimed water application from potential receptors (e.g., potable water supplies). Different levels of treatment can be used depending on the ultimate use of the water, as water quality should only be sufficient to meet needs. An example of this would be removal of nitrates as undesirable in water used for irrigation purposes. Optimal use of reclaimed water in the Middle East, in particular the GCC Nations is explored.
