The History of Desalination
Desalination is the process of removing salt from seawater. It had been crudely used by Greek sailors during the 14th century. Since then, more than 120 countries utilize desalination for providing their citizens with adequate water. In fact, Saudi Arabia uses desalination for 70% of its water needs, and desalination plants in Israel supply half of the population’s drinking water. However, with the ever-increasing global population, the demand for adequate water increases as the supply of water per capita decreases. As of now, desalination would seem to be the best solution to prevent widespread dehydration of future generations, but is it really the best solution for years to come? (1)
San Diego’s Dilemma
In San Diego, the signs of drought are undetectable. Water sprinklers shower upon fresh, green grass, and kids still play in pools on hot summer days. However, beneath the surface, there is another story. In 2015, it was 4 years since San Diego had rain, and they had record high temperatures. Since then, California has imposed conservation methods that require 25% reduction in water usage, including agricultural producers, who consume 80% of the state’s water. Poseidon Water, the leading water desalination developer in the U.S., has spent more than a billion dollars and 3 years to build a desalination plant in San Diego, called the Carlsbad Desalination Plant. By being situated near the coast, the desalination plant has access to the largest reservoir in the world, the Pacific Ocean. (1)
One of the Largest Desalination Plant in the U.S.
The Carlsbad Desalination Plant works by first drawing seawater through ocean intake plants, where screens are used to keep marine animals out. Second, sand and chemical filters further clean the sea water. Third, the water is then pushed through thousands of tubes, each with filters so fine that only water can get through, but the larger particles of salt cannot. This process is called Reverse Osmosis. It uses half as much energy as it did 20 years ago and pumps out a higher volume of water than ever before. Moreover, the captured salt is diluted with the cooling water from the nearby power station and is discharged back to the ocean. Pipes then pump the fresh water remaining to more than 112,000 homes and 300,000 people in San Diego, which is 1/10 of San Diego County’s population. This will increase the water bill by about 6% for residents and set the monthly bill to about $5 for water from Poseidon Water. Bob Yamada, a San Diego County Water Authority, has stated, “We are able to produce up to 54 million gallons a day of desalinated ocean water. That is enough to fill an Olympic sized pool every 18 minutes.” (1)
The Disadvantages to Desalination
However, today, scientists and researchers have found that desalination may not be the perfect solution for the future. First, desalination is expensive. The price tag for the water is often obscured by corporate underestimates and government subsidies. It is often 2-4 times as costly as traditional options. Second, desalination harms the environment and human health. Bi-products from desalination include coagulants, bisulfates, and chlorines. Furthermore, power plants’ intake mechanism in desalination plants kill at least 3.4 billion fish and other marine organisms annually. Also, it causes fishermen to lose at least 16.5 million pounds of fish a year today and 717.1 million pounds of potential future catch. Though some state that dumped concentrated waste is harmful to marine life and the environment, Poseidon Water has replied that it won’t affect marine life. Third, desalinated water puts drinking water supplies at risk. Seawater contains chemicals like boron, that fresh water does not. In fact, during the desalination process, only 50-70% of the boron is removed. This is troubling as boron has been linked to reproductive problems, developmental problems in animals, and irritation of the human digestive tract. Additionally, current drinking water regulations don;t protect the public from boron. Fourth, desalination contributes to global warming and requires large amounts of energy. Statistically, desalination plants burn about 840 megawatts a day, which is equal to the amount of electricity used to power nearly 30,000 homes (1). It takes 9 times as much energy as surface water treatments and 14 times as much energy as groundwater protection. Emissions given off by desalination plants contribute to global warming as well. Finally, desalination turns water into a commodity. Private corporations are investing into desalination because it’s a leading growth area in global water market. They want to set themselves up to sell water for a profit. Private control of water makes it much harder to ensure public safety. (2)
In conclusion, desalination still has a lot to go to become the thing of the future. With our ever-growing population, we require a source of water that can adequately supply us and future generations. However, the question is, will the oceans last for decades to come if the whole world decides to desalinate them?
- Taibbi, Mike, director. Is Desalination the Future of Drought Relief in California? YouTube, PBSNewsHour, 31 Oct. 2015, http://www.youtube.com/watch?v=3Skuk8DeXpE&list=W
- Fried, Kate. “Ocean Desalination No Solution to Water Shortages.” Food & Water Watch, 2 Feb. 2009, http://www.foodandwaterwatch.org/news/ocean-desalination-no-solution-water-shortages.
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