To the casual observer, it may be difficult to understand the world’s growing water woes; after all, the majority of the planet is comprised of water.
The problem is of course that an overwhelming percentage of this life-giving resource is salt water – a characteristic that renders it utterly useless for consumption or irrigation.
Surely though, in an age where humanity continues to learn so much each and every day about the world we live in, about the fundamental building blocks and laws that govern the universe, someone, somewhere must have developed the technology capable of extracting the salt from saltwater.
The truth is, while the technology exists (and has for some time), there are significant hurdles to its widespread implementation.
Why Desalination Projects Have Typically Been Viewed As a Last Resort
The first hurdle, of course, has been the cost. Purifying seawater takes an enormous amount of energy. To become freshwater, saltwater must pass through a series of ultra fine filters at an incredibly high pressure – a process that requires a copious amount of energy. Aside from being costly, it can also be detrimental to the environment, depending on how the energy is produced.
To give it some perspective, the average cost to process 1,000 gallons of saltwater into freshwater can be as high as five dollars; admittedly, that doesn’t sound like a lot but in truth, it’s more than twice the cost of processing freshwater.
The second hurdle is one that continues to make conservationists wary, and that has to do with the environmental impact a desalination plant has on the ocean. Plants must be mindful of the manner in which ocean water is drawn into the facility; simply inserting a pipe into the ocean would decimate local populations of fish and other sea creatures as a great many of them would invariably be sucked into the pipeline.
Regulators in California, a state that has long endured the effects of a prolonged drought, prefer instead that the water be taken by an intake system installed beneath the seafloor (a method believed to be the least disruptive to ocean life), but many builders believe that to do so is cost prohibitive.
The third hurdle is the salt, or brine leftover from the desalination process. The process itself converts only half of the drawn water into drinkable water, leaving the other half a dense, salty mixture. Because this desalination by-product doesn’t mix particularly well with regular saltwater, returning it to the ocean in an irresponsible manner could harm or even kill the ocean’s wildlife, creating yet another environmental concern.
In Spite of the Hurdles, Desalination Plants Still Have Their Place as Part of a Larger Water Management Strategy
In places of exceeding rare rainfall like California in recent years, desalination plants can certainly play a role in reducing the hardship millions of residents and farmers face as a result of a prolonged drought.
There are many methods by which municipalities can ensure the preservation of their water supply without the exorbitant financial and environmental costs of state of the art infrastructure. Of course, desalination plants are a very effective way to bolster an unforeseen drop in a region’s water supply, but that requires municipalities to become reactive towards these issues.
Scheduling regular pipeline condition assessments helps to avoid calamitous leaks by identifying any potential weak equipment that may be close to rupturing, preventing the needless waste of thousands of gallons of water.
Likewise, installing monitoring equipment at key junctures, such as continuous water main leak detection units can help crews pinpoint exactly where the system has failed, expediting repairs.
Desalination and water monitoring can only drive results so far. The primary factor in places like California comes from the residents’ willingness to conserve their own water supply. That means avoiding the temptation to water plants and lawns on days of extreme heat, and imposing limits on one’s own discretionary water usage.
In June of 2013, Governor Brown instituted a 25% urban conservation mandate. Since then, Californians have saved enough water to satisfy the demand of 1.19 million people, a result that desalination plants played a key role in. Are desalination plants a legitimate method by which to eliminate the earth’s water supply? It’s possible. But first, we must resolve any lingering concerns relating to cost and environmental impact.