With the recent opening of the largest plant in North America, desalination has garnered attention from water stressed communities. The process involves extracting salt from ocean water to produce freshwater. Although pulling from a seemingly endless supply of water (the ocean) appears to be a viable solution, researchers and environmentalists across the globe have highlighted a number of concerns.
The Carlsbad desalination plant is capable of supplying up to 50 million gallons of potable water per day. It is also able to provide “as much as 10% of the region’s drinking water,” reducing the amount of water imported from other areas.  But desalination plants of this size require high amounts of energy to operate efficiently. Between the large daily water intake, treatment process and overall footprint of the facility, an article in Public Radio International reports “desalination plants around the world use more than 200 million kilowatt-hours each day.”  Reverse osmosis systems, the most popular treatment technique in desalination facilities,  can use over ten times more energy than traditional drinking water treatment systems. 
The United States set a goal to reduce carbon pollution 80 percent or more by 2050 ; the intensive energy consumption from desalination facilities may hinder the achievability of this goal. According to Heather Cooley, Water Program Director for the Pacific Institute, “If we are dramatically increasing our production from seawater desalination, that could dramatically increase our greenhouse-gas emissions at a time when we’re trying to reduce them.” 
While the energy demands are high, so are the operational costs. The energy requirements account for nearly half of the facility’s operations and maintenance costs, sometimes even more.  The process of desalination is nearly double the price of wastewater treatment.  Additionally, freshwater from desalination, based per thousand gallons, can cost the “average US consumer” more than twice the price of traditional freshwater. 
According to a report by the Pacific Institute, “Electricity prices in California are projected to rise by nearly 27% between 2008 and 2020 (in inflation-adjusted dollars).”  The report continued, “While rising electricity prices will affect the price of all water sources, they will have a greater impact on those that are the most energy intensive, like desalination.” 
The process of desalination also has numerous environmental implications. The desalination process requires large amounts of water to be drawn directly from the ocean. This water intake can harm many aquatic creatures and “organisms small enough to pass through, such as plankton, fish eggs, and larvae, are killed during processing of the salt water.” 
For every two gallons of saline water taken from the ocean, one gallon of freshwater produced. The salty water is usually then discharged back into the ocean, twice as saline.  The Pacific Institute states, “The brine is denser than the waters into which it is discharged and tends to sink and slowly spread along the ocean floor, where there is typically little wave energy to mix it.”  This may affect bottom-dwelling organisms that are not acclimated to the high salt concentration.
Long-term research is needed to analyze the overall implications of desalination discharge. Cooley explained “monitoring of existing and proposed desalination plants is crucial to improving our understanding of the sensitivity of the marine environment.” 
While desalination may be considered a solution to the current water stresses, the potential challenges it could create in the future remain a mystery. New developments are already underway to reduce the energy and environmental impacts; however, further research may be needed to determine the long-term effects of desalination.
Published: May 31, 2016
 Johnson, Chris. Desalination: the quest to quench the world’s thirst for water. The Guardian, May 27, 2015. Web. https://www.theguardian.com/technology/2015/may/27/desalination-quest-quench-worlds-thirst-water  Bienkowski, Brian. Desalination is an expensive energy hog, but improvements are on the way. Public Radio International, May 13, 2015. Web. http://www.pri.org/stories/2015-05-15/desalination-expensive-energy-hog-improvements-are-way  Herndon, Andrew. Energy Makes Up Half of Desalination Plant Costs: Study. Bloomberg, May 1, 2013. Web. http://www.bloomberg.com/news/articles/2013-05-01/energy-makes-up-half-of-desalination-plant-costs-study  The White House. FACT SHEET: U.S. Reports its 2025 Emissions Target to the UNFCCC. The White House, March 31, 2015. Web. https://www.whitehouse.gov/the-press-office/2015/03/31/fact-sheet-us-reports-its-2025-emissions-target-unfccc  Cooley, Heather; Heberger, Matthew. Key Issues in Seawater Desalination in California: Energy and Greenhouse Gas Emissions. Pacific Institute, May 1, 2013. Web. http://pacinst.org/publication/energy-and-greenhouse-gas-emissions-of-seawater-desalination-in-california/  Cooley, Heather; Ajami, Newsha; Heberger, Matthew. Key Issues in Seawater Desalination in California: Marine Impacts. Pacific Institute, December 11, 2013. Web. http://pacinst.org/publication/desal-marine-impacts/  Claude “Bud” Lewis Carlsbad Desalination Plant. FAQs. Carlsbad Desalination Project. N.D. Web. http://carlsbaddesal.com/faqs