Water is said to be the next oil. Countries are using and wasting much more water than they should, leading to over-abstraction, new desalination plants and water treatment plants being built. Securing water sources is a necessity for a country and its assets to remain viable. While at large there is a general focus to consume less water globally; in the Middle East, there should be an even greater drive not to let treated sewage effluent (TSE) go to waste. In the region, an excess of approximately 40 percent to 60 percent of TSE is wasted. Locally, excess production leads to over-irrigation, disposal at sea and flooding highlighting the need to put TSE to better use while considering the local environment, culture and regulations.
Aquifer recharge & recovery
TSE can and should be recycled but this requires a change in thinking from being a choice and cost to a necessity and investment. The solution is either direct or in-direct reuse of TSE – indirect is preferred and generally accepted by stakeholders as there is an environmental buffer that also acts as storage whereas direct use cannot store water (without building huge reservoirs) if there is no immediate need. Taking into account the high evaporation rates, limited amount of rechargeable water resources and declining groundwater table, aquifer recharge and recovery is the optimal choice for the Middle East. Recharged groundwater is a good water source, and can also help prevent salinization of existing wells and prevents or reduces salt water intrusion. Merely, 60 percent of the region’s TSE could be stored in the aquifer and used at a later time rather than be uncontrollably discharged. There are three different approaches to aquifer recharge that can be considered: aquifer storage and recovery (ASR); aquifer storage transfer and recovery (ASTR) and aquifer recharge & recovery (ARR) – ASR is the forthright technique where water is re-injected back into the aquifer for later recovery and using a single well; ASTR allows for water to be injected into an aquifer, stored for a prolonged period and pumped up through another well, enabling natural treatment to occur as it moves through the ground; while ARR involves building infrastructure or modifying an existing landscape such as a wadi to enhance groundwater infiltration, also enabling natural treatment. There is currently minimal implementation or planning taking place across the GCC for aquifer recharge using TSE. Abu Dhabi and Doha are currently pumping excess desalinated water in the aquifer to act as emergency storage whereas the use of TSE is still in the midst of research. The outcomes of aquifer recharge are good for countries economically and environmentally – saving costs, reducing the carbon footprint and improving the environment.
“… Aquifer Recharge and Recovery is the optimal choice for the Middle East”
Water opportunities for the region
Whilst the region is progressing, there is still an essential requirement for overcoming constraints that enable aquifer recharge in the region, specifically using TSE. The Middle East can look into global knowledge sharing and learn best practice developments from other markets to implement across the region. The concept is already being used in arid areas of the United States such as California, Illinois, Arizona and Texas, where treated sewage effluent is used for groundwater recharge and then contributes to the production of potable water and to prevent salt-water intrusion. The following contributes to the region’s water success: early involvement of stakeholders; extensive treatment involving reversed osmosis and advanced oxidation to prevent contamination of groundwater by emerging pollutions; and development of local guidelines and regulations. Furthermore, additional research is required to identify suitable aquifers in the region in order to assess the feasibility. At the moment, desalinated water is transmitted over great distances, so that savings to the prevention of production and transmission could be made. The next step involves engaging the regional water community, government bureaus and ministries and associated industries in a conversation that can ultimately implement rules and regulations and highlight strategy and challenges; whilst also involving the wider global community in subjects related to quality and technical involvement. TSE can also be looked at as a source of income by forcing industry to utilize (where appropriate) this water rather than the more costly desalinated potable water. For this to occur, legislation changes will be required to take place, in particular the tariff structures.
“… research is required to identify suitable aquifers in the region in order to assess the feasibility”
The final word
The region has a remaining amount of prospects in the water space, especially when it comes to optimizing TSE utilization in the Middle East. As industry experts, it is our duty to bring together our regional and international expertise to drive environmental change, local development and ultimately create sustainable solutions. We must start to think of TSE as a valuable resource and not merely a wasteful by-product.
Water Sector Leader
Titia De Mes
Water for Industry Leader