J. Tarchitzky, O. Lahav, A. Tal
With almost half of humanity suffering insufficient access to potable water (1) and water scarcity for agriculture considered to be a global crisis (2), seawater desalination has emerged as a feasible solution. Between 1994 and 2004, world desalination capacity increased from 17.3 to 35.6 million m3/day (3). At present, seawater desalination provides 1% of the world's drinking water (4).
Desalinized water is increasingly considered a source of water for agriculture as well. With 69% of the global water supply going to irrigation (5), present freshwater resources may soon be insufficient to meet the growing demand for food. A recent report (6) concludes that, although the costs of desalination remain prohibitively expensive for full use by irrigated agriculture, for high-value cash crops like greenhouse vegetables and flowers, its use may be economically feasible.
In a few countries, desalinized brackish water (whose price is typically a third of desalinated seawater) is already widely used by farmers. For instance, ∼22% of water desalinated in Spain goes to agricultural irrigation (6). An Australian survey found that 53% of the population envisioned desalinated water usage for irrigation of vegetables as highly likely (7). In Israel, the promise of new, profitable crop options has inspired farmers to request allocations of relatively higher priced desalinized waters.
In December 2005, a new seawater desalination plant was opened in Ashkelon, on Israel's southern Mediterranean coast. Its 100,000,000 m3/year production makes it the largest reverse-osmosis (RO) desalination facility presently in operation worldwide (8). It is also the world's first desalination facility to produce potable water from seawater at a price below $0.55/m3 (9). Although the Ashkelon facility was designed to provide water for human consumption, because of relatively modest population densities in southern Israel, a substantial percentage of the desalinated seawater was delivered to farmers. Recent evaluation of the effect of the plant's desalinized water on agriculture, however, produced some surprising, negative results. Changing these outcomes will require modifying future water management orientation and revision of desalination standards.
J. Tarchitzky, O. Lahav, A. Tal
With almost half of humanity suffering insufficient access to potable water (1) and water scarcity for agriculture considered to be a global crisis (2), seawater desalination has emerged as a feasible solution. Between 1994 and 2004, world desalination capacity increased from 17.3 to 35.6 million m3/day (3). At present, seawater desalination provides 1% of the world's drinking water (4).
Desalinized water is increasingly considered a source of water for agriculture as well. With 69% of the global water supply going to irrigation (5), present freshwater resources may soon be insufficient to meet the growing demand for food. A recent report (6) concludes that, although the costs of desalination remain prohibitively expensive for full use by irrigated agriculture, for high-value cash crops like greenhouse vegetables and flowers, its use may be economically feasible.
In a few countries, desalinized brackish water (whose price is typically a third of desalinated seawater) is already widely used by farmers. For instance, ∼22% of water desalinated in Spain goes to agricultural irrigation (6). An Australian survey found that 53% of the population envisioned desalinated water usage for irrigation of vegetables as highly likely (7). In Israel, the promise of new, profitable crop options has inspired farmers to request allocations of relatively higher priced desalinized waters.
In December 2005, a new seawater desalination plant was opened in Ashkelon, on Israel's southern Mediterranean coast. Its 100,000,000 m3/year production makes it the largest reverse-osmosis (RO) desalination facility presently in operation worldwide (8). It is also the world's first desalination facility to produce potable water from seawater at a price below $0.55/m3 (9). Although the Ashkelon facility was designed to provide water for human consumption, because of relatively modest population densities in southern Israel, a substantial percentage of the desalinated seawater was delivered to farmers. Recent evaluation of the effect of the plant's desalinized water on agriculture, however, produced some surprising, negative results. Changing these outcomes will require modifying future water management orientation and revision of desalination standards.