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The desalination debate

(article, Stephanie Beechem)

“Desalination” seems to be a buzzword on many politicians' and farmers' tongues these days, but that doesn’t mean it’s the best answer to a worldwide water shortage. In fact, the conservation group WWF announced recently that the process of desalination — filtering salt out of brackish or ocean water to create fresh water — will not only worsen the worldwide shortage of drinking water, but will also accelerate the rate of climate change, due to the inordinate amount of greenhouse gases released into the atmosphere during the process.

Furthermore, the WWF said, desalination plants’ large intake valves inevitably pull in small organisms such as fish larvae, eggs, and plankton, most of which die during the process. Even worse, once the purification process is complete, desalination plants discharge the highly concentrated salt waste product — brine — back into the ocean, where it artificially raises the salinity of the ocean itself and can damage both fish and plants.

There are, of course, undeniable benefits of desalination, not the least of which is making drinkable water available in some of the neediest areas of the world. Earlier in June, China announced plans to build its largest ever desalination plant in Xiangshan for $144 million to provide water to its most impoverished citizens. Australia’s newest plant is slated to cost even more, at $450 million, but it will provide a huge one-third of the drinking water consumed in drought-prone Melbourne. Other interested regions of the world include France, India, the Middle East, Spain and, in the U.S., California, Las Vegas, and some parts of Florida, where lawmakers are currently building the largest desalination plant anywhere on the continent.

The desalination process, which was once so costly that few considered it a reliable alternative to treating fresh water, has become increasingly efficient and streamlined in the past few years thanks to new, more energy-efficient filtering technologies, which helps explain the recent boom in interest. 

But compared to processing fresh water, the costs of desalination are still astronomical. So why the big interest from governments and businesses? 

The answer is simple: We’re not conserving enough. Conservation is key to solving this very complicated problem, but it’s difficult to achieve. Although conserving water supplies and recycling used water are two ways that individuals can help, the real problem does not lie with individual waste but rather with agriculture. In California, for example, agricultural water use makes up a staggering 80 percent of the state’s total water used. These are the kind of egregious water abuses our government should investigate and regulate before desalination ever enters the picture. Businesses and farmers, given an incentive or marshaled with a law, will find ways to reduce and reuse water rather than flooding fields with it simply because it’s cheap and available. 

That’s the thing — one day, it won’t be, and desalination in its current form isn’t looking like any kind of solution.