Is Desalination the Future of Water?

Almost three quarters of the surface of the earth is covered by water, and 96 percent of that water is found in oceans.  Fresh water is becoming ever more important as a finite resource.  While some look to the oceans as a solution to the limited fresh water supply, oceans hold saline water, something that is neither good for human consumption nor agricultural use. Desalination, a process that turns saline water into fresh water, may be the solution to the problem.

Until recently, desalination was only widely used in the Middle East, particularly in Saudi Arabia.  There are currently desalination plants in many countries, including the United States and Australia, with China about to overtake Saudi Arabia as the world leader, by capacity, of desalinated water.  Soon, the United States will also have more desalination plants, including a plant outside San Diego, California, known as the Carlsbad Desalination Project.  It is a state supported project, with the California Pollution Control Financing Authority currently selling tax-exempt bonds to finance the construction of the plant.  The plant in expected to be operational by 2016 and will have the capacity to create over sixty-thousand acre-feet  of fresh water per year, making it the largest capacity plant in the western hemisphere.

In addition to potential human consumption and agricultural use, desalinized water is also used for other projects such as mining.  The biggest challenge for many mining projects in arid regions is finding water.  For example, there are plans to pump desalinized water to the Mantoverde copper mine in Chile, where the water will be used to separate the copper from the ore. While more desalination projects could benefit industries such as mining and oil and gas production, the process has been criticized by many.

 Desalination Condemned

Although many governments and organizations are choosing desalination as a solution to their fresh water woes, there are just as many critics of the process.  Critics, including the non-profit organization, Food & Water Watch, claim that desalination is the most expensive type of water management, and that the expenses will be passed along to consumers, leading to corporate abuse of a social and basic life-sustaining need.  The Food & Water Watch also claims that desalination methods have a negative environmental history and the extreme environmental costs far outweigh the benefit of providing fresh water.  Costs include the massive amount of energy, often provided by fossil fuels, required to run such a plant.  There are concerns that desalination will become popular in places without strong environmental laws, and others are worried that the desalination plants extensive duct systems harm marine life through intake pipes and toxins.

One of the largest environmental impacts of the desalination process is the brine.  Desalination removes salt and minerals from the water, and creates hyper-saline brine that must be disposed.  Often, the brine is sent back into the oceans, but as brine is denser than most ocean water, it sinks and settles on the ocean floor, affecting marine ecosystems, and ocean life.  In states like California, National Pollutant Discharge Elimination System (“NPDES”) permits are issued through the Water Boards to regulate brine releases from desalination facilities, and the permits have conditions protecting aquatic life.  Those permits do not directly address the elevated salinity in the oceans, how brine discharges are actually controlled, or the method of intake from the ocean.  However, the permits do address marine life.  It is important to note that other processes like wastewater treatment and recycling also create brine that is similarly discharged.

Hope for a Desalination Future

Some desalination plants are not as environmentally destructive as critics claim.  For example, a California Federal Court of Appeals held that the Carlsbad Desalination Plant would not violate environmental laws.  In the case, an environmental organization, the Surfrider Foundation (“Surfrider”), claimed the desalination project would violate California’s clean water laws.  Surfrider originally petitioned the California State Water Resources Control Board to review the NPDES permits given to the desalination project claiming that wetland restoration was the only substantive measure put in place, through the permits, to reduce the intake of and affects on marine life.  Surfrider focused on Cal. Wat. Code § 13142.5(b) that requires new or expanding coastal plants or industrial facilities using seawater to “minimize the intake and mortality of all forms of marine life.”  Surfrider then took its claim to the San Diego County Superior Court.  The court held, and the Appellate Court agreed, that Surfrider did not have factual support for their claim.  The actual approved minimization plan uses wetland restoration, along with site, design, technology and mitigation measures to reduce intake and mortality of marine life.

With desalination gaining popularity, more companies have entered the market, and research on the processes is quickly growing.  With more efforts focused on the technology, and a larger and more competitive market, the process if becoming more efficient and more affordable.  The developer of the Carlsbad Project claims the more expensive water will only translate into an additional $5 to $7 in residential users’ monthly water bills.  Some desalination plants are also switching to cleaner forms of energy, and as the costs of solar cells continues to decrease more plants will begin to use cleaner energy.  Although the brine and water intake may have future environmental repercussions, with the larger market and better research, the process could soon become more environmentally friendly.  Also with a larger market, more governments will take notice and regulate desalination procedures; many states and counties are already developing laws regulating desalination.


Billions of people do not have guaranteed daily access to potable water.  Currently, an estimated one billion people are gaining access to potable water through desalination.  Alternatives to desalination like conservation and wastewater recycling are likely not enough to provide potable water for such large numbers.

More municipalities, regions, and countries have many reasons for opening desalination facilities, including: creating a long-term solution to water shortages; creating a drought-proof resource; maintaining the local economy; and sustaining the quality of life.  These are the reasons are why many governments are prioritizing clean water for millions of the citizens over potential harm to marine life and the environment.

Regardless of the environmental costs, desalination will continue to increase in use.  Even if the continued research and use show that the brine is extremely harmful to the environment, it is unlikely that some countries, such as China, would stop using their desalination facilities.