As a board member for the International Desalination Association (IDA) and the American Membrane Technology Association, Doug Eisberg likes to clear the air—or water—when talking about desalination technologies. "I think with desalination trends in general, it's important to note when I speak to people about desalination, 'What is desalination?' Because it's really commonly misunderstood," said Eisberg, who serves as director of business development for Avista Technologies Inc., a Southern California-based company that specializes in water treatment chemicals and support for membrane systems.
"The term desalination, it's removing dissolved salts, so there's desalination to remove salt from water. Most people think of seawater like sodium chloride … but there's a lot of other salts out there," Eisberg told Pumps & Systems. "They change the purity of water, so typically when you desalinate, you're trying to remove something called a dissolved solid from water you're desalting."
Although desalination technology is commonly used with seawater, brackish water—a mix of saltwater and freshwater—and wastewater, there are numerous applications besides drinking-water production. "It's not just in municipal drinking water but in everything else we use or touch every day," Eisberg said. "In the food and dairy industry, desalination is used to make everything from baby food to Ensure, so if you're a baby or a senior, you're using a product" made with desalination technology.
The smartphones and tablets that have become a mainstay of modern-day life represent a prime example of how desalination works in other industries, Eisberg added. "That technology was made available because desalination was used to remove the impurities from the water that cools microchips. When the industry went to desalinated water, that's what allowed chips to get smaller and smaller," he said, also pointing to the beverage, mining and power generation industries that use the technology.
"From the moment you get up with the alarm clock that uses a chip from desalination to your toothpaste made from desalinated water to taking a shower using water that comes from a membrane desalination process … it's impressive how much the technology touches our lives every day—and people aren't aware of it," Eiseberg said.
From a drinking-water standpoint, perhaps no other place showcases what desalination technology is capable of doing in the U.S. than in Southern California at the new Claude "Bud" Lewis Carlsbad Desalination Plant. "What the important thing about Carlsbad is … it's really state-of-the-art for seawater desalination," Eisberg said.
Carlsbad Makes a Splash
Named in honor of the late mayor of the beachside community nestled between the Los Angeles and San Diego areas, the Carlsbad Desalination Plant received its formal dedication as the largest seawater desalination facility in the Western Hemisphere during a ceremony Dec. 14, 2015. At the time of the dedication, the facility had already produced more than 1.5 billion gallons of water for San Diego County.
The reverse osmosis facility produces about 50 million gallons of drinking water daily for the region. On a typical day, the plant uses about 100 million gallons of seawater from the Pacific Ocean drawn into the pump station through a 72-inch feed pipe, according to the facility. With about half the water converted for drinking purposes, the other half—carrying original salts and minerals—is returned to the ocean.
"It's a gold-plated plant," said Reese Tisdale, president of Bluefield Research, a Boston, Massachusetts-based firm that focuses on strategic water analysis. "It's the newest and best technology out there. … At least in the U.S., it sets a new price point and operating benchmark for desalination."
The project that started in 1998 resulted from a 30-year water purchase agreement between the plant's owner and developer, Boston-based Poseidon Water, and the San Diego County Water Authority for the production of up to 56,000 acre-feet of water annually, according to the firms. The production addresses ongoing drought concerns in the area and meets about 7 to 10 percent of the region's water demand.