Desalination

In 2019 Iranian drones and missiles staged a surprise attack on Saudi Arabia’s oil facilities. An article in The Economist  noted the Saudi’s vulnerability to a wider conflict, adding Saudi officials worry “that a well-placed salvo of missiles aimed at desalination plants could render the Gulf unlivable within days.”

The desert kingdom of 35 million people has very little fresh water and cheap energy costs. Its desalination plants produce half of its water, more desalinated water than any other country, and a fifth of the world’s total.  A decade ago the Saudi minister for water and electricity estimated that the kingdom was using a quarter of the oil and gas produced in the country to generate electricity for its desalination plants.

Water scarcity is pervasive throughout the Arabian Peninsula. Like Saudi Arabia, rulers of Oman, Qatar, Bahrain, Kuwait and United Arab Emirates have used their oil and gas riches to build desalination plants to support their growing populations. Qatar’s domestic water comes entirely from desalination plants, providing free water for its citizens. Plants are proliferating in Israel, Egypt and Jordan; Israel’s five plants on the Mediterranean Sea provide half of the country’s domestic water needs.

These arid regions of the Middle East are half of the desalination story. The world’s 16,000 to 18,000 desalination plants (estimates vary by reporting source) are spread among 120 countries, with 50-70% of the desalinated water produced in the Middle East. Intermittent drought and climate warming have turned water-stressed areas around the world to desalination.

Over 1,400 desalination plants are in the United States. The majority are being used to desalt brackish groundwater. The remainder process seawater along the coasts of California and Florida. Decreased Rocky Mountain snowfall over the past two decades has reduced flow in the Colorado River, a source of fresh water for states in the Southwest United States. Carlsbad, the largest of twelve desalination plants in California, provides 12% of San Diego County’s water; a thirteenth desalination plant is proposed for Huntington Beach.

Desalination has a limitless supply of seawater, while surface water depends on intermittent snowfall and rain. But desalination comes with its own disadvantages. Desalination takes enormous amounts of energy to force seawater through the membranes that filter it, in turn creating environmental impact. The process discharges a brine consisting of concentrated saline and other chemicals that are harmful to aquatic ecosystems. Various efforts are employed to dilute the brine before discharging it back into the ocean. Chemicals in saltwater, such as magnesium, calcium, lithium and pure sodium chloride can be extracted to offset the costs of production.

For nearly one hundred years California has moved water to Southern California from the Colorado River. Starting in the 1960’s, water from the Sacramento and San Joaquin Rivers has been transported hundreds of miles to Southern California via a system of dams, reservoirs, power plants, pumping plants and aqueducts. Although the end user cost of desalinated water is approximately twice the cost of water from traditional sources, the additional expense is deemed necessary for water security. As in other parts of the world, desalination serves as a safeguard against future impacts of climate warming.