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The three cities of Abu Dhabi Emirate within the United Arab Emirates – the coastal city Abu Dhabi itself (more than one million inhabitants) as well as the inland oases Al Ain (0,4 million inhabitants) and Liwa (about 0,1 million inhabitants) – receive their drinking water supply entirely from desalinated seawater. Their wastewater is being treated and reused for the irrigation of green spaces.〔 == Water resources == There are two main sources of water in Abu Dhabi Emirate: Desalinated seawater and groundwater. While groundwater is used for agriculture in Al Ain and Liwa, drinking water is provided almost entirely from desalinated seawater across the Emirate. In 2008, groundwater contributed 71% to total water demand for all purposes, desalinated water 24% and treated wastewater 5%.〔UAE Interact:(EAD warns against depletion of Abu Dhabi's water resources within next 50 years ), 22 March 2009〕 ;Seawater desalination In 2010, there were eight seawater desalination plants in Abu Dhabi owned and operated by eight joint ventures: Tawilah A, Tawilah B, the five Umm al Nar plants and the Al Mirfa plant. These joint ventures between the government and foreign companies, which are allowed to own up to 40% of the shares, are called Independent Water & Power Producers (IWPPs). They operate under Build-Own-Operate (BOO) contracts with the government and their energy is supplied by fossil fuels. In the model green city called Masdar City, four smaller pilot desalination plants that will use solar power are nearing completion as of early 2015. ;Groundwater 90% of groundwater in Abu Dhabi Emirate is saline, in some cases up to eight times as much as seawater. There are only two freshwater aquifers. Natural groundwater recharge is estimated at about 300 million cubic meters per year. Brackish groundwater is mostly used for the irrigation of date palms which are relatively salt-tolerant. Recharge dams have been built on wadis in order to prevent flood water to flow into the sea, recharging it instead to aquifers. Unplanned and uncontrolled groundwater withdrawals, especially for agriculture and forestry, total over 2,000 million cubic meters per year and have resulted in declining groundwater levels and quality.〔Environment Agency of Abu Dhabi: (Abu Dhabi Water Resources Statistics 2006 )〕 ;Groundwater recharge Artificial groundwater recharge with desalinated seawater has been piloted in 2003 near the Liwa Oasis and construction of large-scale recharge facilities has begun in 2008. The objective is to create a 90-day reserve instead of the current 48-hour reserve for drinking water supply, in order to protect the emirate against the risk of terrorist attacks or oil spills that would shut down the entire water supply. Recharge will occur during summer when the desalination plants generate surplus freshwater. Desalination plants in Abu Dhabi use the multi-stage flash distillation technology which uses steam from thermal power plants as an energy source. Their water production thus is proportional to electricity production and reaches a peak during the summer when electricity production is highest to power air conditioning. The recharge scheme is currently under construction and is due to be completed by 2013.〔Frankfurter Allgemeine Zeitung: (Viel Erdöl und wenig Wasser, Ein deutsches Projekt schafft in Abu Dhabi eine Wasserreserve unter dem Wüstensand ), 17 June 2010〕〔GTZ: ( Artificial Recharge and Utilization of the Ground Water Resource in the Liwa Area ), accessed on June 27, 2010〕 ;Sanitation Approximately 550,000 cubic metres of wastewater is generated in Abu Dhabi every day and treated in 20 wastewater treatment plants.〔 Almost all of the wastewater is being reused to irrigate green spaces.〔Gulfnews.com: (Abu Dhabi regulates water usage ), 28 March 2009〕 While most wastewater treatment plants are publicly owned and operated, four large new plants have been built by joint ventures under build-own operate transfer (BOOT) arrangements. One such contract for two plants was awarded in 2008, one in Abu Dhabi itself with a capacity of 300,000 cubic meter per day and one in Al Ain with a capacity of 130,000 cubic meter per day.〔Cleantech group: (Veolia, Abu Dhabi in wastewater deal ), 31 July 2008〕 Contracts for two other plants were awarded to Biwater under a similar structure. A Strategic Tunnel Enhancement Programme (STEP) is to be implemented between 2008 and 2014 to establish a tunnel that will comprise 40 kilometres of deep sewerage tunnel and two new large pumping stations to relieve Abu Dhabi Island.〔UAE Interact: (Tunnel planned to tackle capital wastewater issue ), 30 June 2008〕 In Masdar City green spaces and agriculture near the city are to be irrigated with grey water and reclaimed water. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Water supply and sanitation in Abu Dhabi」の詳細全文を読む スポンサード リンク
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