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Waste from a water desalination plant in the sea of Al-Dohan Jahra region, Kuwait (29°21’ N, 47°49’ E).

For a long time Kuwait depended upon imports from Iraq for its supply of drinking water, but today it has several seawater desalination plants that produce 75% of the country’s water supply. These plants use the instant thermal distillation technique (also known as the «flash» system). After treatment, water unfit for consumption is rejected into the sea, where it mixes with the waters of the Persian Gulf, creating the shape of a tentacled monster. Thanks to 12,500 desalination plants in 120 countries, the Earth’s oceans furnish almost 5,300 million gallons (20 million m3) of fresh water—around 1% of the fresh water consumed in the world. Two-thirds of this derives from seawater, and the remaining third from estuaries. Desalination plants require enormous amounts of energy and are expensive to operate and thus are available only to states that have considerable resources, particularly petroleum, such as those in the Persian Gulf, which produces half of the world’s desalinated water. One ton of fuel is needed to produce around 26,400 gallons (100 m3) of fresh water. At a time when the need for fresh water is a concern in a growing number of countries, Europeans use 66 to 92 gallons (250 to 350 liters) of water per person each day (a single toilet flush uses 1.5 gallons, or 6 liters).