Assist. Prof. Vakur Sümer, ORSAM Advisor, Selçuk University

The countries of the Middle East, most of which rank among the world’s most water-scarce ones, should focus more on reusing existing water resources. Reusing the treated sewage effluent (TSE) is one of possible routes to water efficiency, something gravely needed in the region as a whole. A recent report by Dutch water infrastructure company Arcadis, which stated the significance of using TSE in the Middle East, attained an international acclaim. Transboundary technical and economic cooperation with an aim of increasing the overall capacity of using treated sewage effluents for groundwater recharge could ameliorate the water problems as well as contribute to the easing of the tense state of affairs in parts of the area.

In the Middle East, groundwater resources are already under stress. Existing stress on groundwater resources tend to rise during prolonged drought periods. Drier times cause people to resort to water wells in order to sustain their living, water their fields, supply water for their animals, etc. One example for this was observed in the Euphrates-Tigris transboundary river basin. In a study published in 2012, scientists utilized the Gravity Recovery and Climate Experiment (GRACE) satellite mission in order to analyze trends in freshwater storage in the north-central Middle East from January 2003 to December 2009. The study revealed that the region concerned lost some 144 billion cubicmeters of freshwaters during the study period. (1)

This is a very sizable amount particularly when we think of the actual capacities of reservoirs or average annual flows of rivers in the region. For instance, 144 billion cubicmeters of water is nearly three times larger than the greatest dam in the basin, Ataturk Dam, with a reservoir capacity of 48 billion cubicmeters. The water lost also dwarfs the annual average flow of Euphrates which fluctuates between 30-32 billion cubicmeters. Tigris, which flows at an annual rate of 52 billion cubicmeters, needs almost three years to reach equivalence with the amount of water lost in just seven years. Thus, countries of Euphrates and Tigris, as well as many other parts of the Middle East, are now more pressed than ever to critically assess the way they used to go in water management.

The study also found that some 60% of this lost water comes from groundwater. This is quite alarming in the sense that groundwaters were utilized by the people of the region at large as a reserve source in times of drought. When such safety valve is lost, the next drought can result in catastrophe. Therefore, it is of utmost significance to keep groundwaters as replenished as possible. TSE has a great potential for protecting these vital resources of water. It is also environmentally sound given the fact that recharging aquifers with TSE can help in struggle with the problem of salt intrusion into water. Last but not the least, it has been suggested that using TSE for groundwater recharge and recovery could contribute to better use of desalinated water in Gulf countries. Instead of pumping costly desalinated water to aquifers, countries like Qatar and United Arab Emirates can, instead, use it as potable water. UNDP, in 2013, reported that treated effluent could be regarded as an important source of water in areas of extreme scarcity, such as Jordan and Tunisia. Since the level of uncertainties in treated sewage effluent is not a big concern as compared to those of surface water resources, UNDP recognizes it as a viable option which can relieve some of the stress over water resources which is mainly due to rapid urbanization and population growth.

Anticipating all the advantages of using TSE, Kuwait appears to be one of the pioneers in the region. It aimed to utilize 100 % of its TSE. Despite this good example, it is also known that around half of the TSE in the Middle East is being wasted, particularly through disposal at sea.

In brief, there is a big potential for TSE in the most water-scarce region, i.e. Middle East. However, opportunities coexist with the challenges. First and foremost, more scientific research is essential in order to conduct feasibility studies of the projects. Yet, there are serious data gaps in vast parts of the region such as Iraq, and increasingly Syria. Ongoing instabilities in these regions do not allow for in-depth scientific inquiries. Another challenge is the existence of transboundary aquifers dynamics of which have not been adequately studied, so far. All co-aquifer countries should agree on common grounds for studying this type of aquifers. This is not easy for well-known reasons such as the lack of trust among many countries in this part of the world.

All in all, management of water resources in the Middle East is in flux. Not only enduring (e.g. population pressures) but also newly emerging (e.g. climate change) challenges force countries countries to reassess and adapt their water use strategies. While countries like Israel appear to be far more advanced in water efficiency than the rest of the region; there are countries like Yemen which suffers from highest rates of water exhaustion in the Middle East. What common to all is -albeit in varying degrees- the challenge of water. Use of TSE for groundwater recharge could be one of the possible solutions that can improve the current status of water use. In this particular case, transboundary cooperation on technical and economic aspects of scientific research and feasibility surveys may generate more optimum results than national initiatives.

(1) Voss, K. A., J. S. Famiglietti, M. Lo, C. de Linage, M. Rodell, and S. C. Swenson (2013), Groundwater depletion in the Middle East from GRACE with implications for transboundary water management in the Tigris-Euphrates-Western Iran region, Water Resour. Res., 49, doi:10.1002/wrcr.20078.