Space & Innovation

US's Largest Water Desalination Plant Opens

Though enormous, the high-tech plant produces 50 million gallons of drinkable water per day. Continue reading →

A massive seawater desalination plant in San Diego is now producing 50 million gallons of drinkable water per day, making it the largest such project in the Western Hemisphere.

The Claude "Bud" Lewis Carlsbad Desalination Plant, a $1 billion public-private venture between Poseidon Water and the San Diego County Water Authority, commenced operations on Monday, the culmination of nearly 20 years of planning, development and construction.

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Each day, approximately 100 million gallons of water from the adjacent Agua Hedionda Lagoon enter the plant through a 72-inch seawater pipe. During the pretreatment process, the seawater cycles through a multi-layer tank that uses anthracite, sand and gravel to remove algae and other large impurities. A second pretreatment then removes smaller particles.

The plant relies on state-of-the-art reverse osmosis technology to remove dissolved salt from seawater; more than 2,000 pressure vessels in the facility contain semi-permeable membranes through which seawater must pass.

"These membranes act like microscopic strainers that allow only water molecules to pass through, leaving behind the salt, minerals and other impurities such as bacteria and viruses," the project's operators explain in press materials.

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After the filtration process is complete, select minerals are reintroduced to the newly potable water, which is then disinfected with chlorine. At that point, the newly potable water is pumped throughout drought-parched San Diego County. Officials estimate that the high-tech plant will satisfy 10 percent of the region's water needs.

Brine, the highly concentrated, salty byproduct that remains, is finally diluted with seawater and reintroduced back into the ocean.

The plant is outfitted with energy-efficient technology that is said to nearly halve energy consumption, saving 146 million kilowatt-hours of energy each year - the equivalent of taking 9,000 cars off of the road.

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Mind-blowing technology aside, the project is not without its critics. The Surfrider Foundation, a nonprofit foundation that has waged a lengthy battle against the plant, has called desalination's environmental impact into question.

"Desalination may be part of the solution eventually, but it needs to be sized and located appropriately. It should be the last tool in the tool box, not the first," the organization writes in a press statement.

This article originally appeared on DSCOVRD; all rights reserved.

Ongoing water shortages around the world, along with recent drought conditions in the western United States, have resulted in a flood of new research and proposals around water technology. We take a look at some concepts -- from simple to complex to rather ancient -- that are designed to help us collect, store, transport and even create water where it's needed most.

The severe drought in California -- now in its third year -- has triggered new interest in a relatively old technology. Desalination plants turn seawater into drinking water by way of high pressure valves and semi-permeable membranes. Traditionally an expensive and energy-intensive process, recent innovations have made desalination a more viable option. The city of Carlsbad, Calif., is set to open the biggest

ocean desalination plant

in the Western Hemisphere later this year.

Desalination plants are efficient, relatively speaking, but they're not very pretty. A couple years back, IBM and Airlight Energy turned heads with their

High Concentration PhotoVoltaic Thermal

(HCPVT) system, designed to generate solar power and desalinate water at the same time. The sunflower-shaped solar collectors use a liquid cooling system that could potentially double as a small-scale desalination plant, providing both energy and water for apartment buildings, hotels or hospitals.

Water recycling is the umbrella term for reuse and reclamation systems that involve treating wastewater and returning it to underground aquifers or reservoirs. Along with desalination, it's among the existing technologies being optimized for large-scale use. San Diego's

Pure Water

project, for example, treats wastewater with three different techniques -- membrane filtration, reverse osmosis, and ultraviolet disinfection -- before piping the recycled water back into reservoirs.

One nice thing is that water generating systems tend to scale down nicely. This

Air Orchard

water-harvesting billboard in Lima, Peru, uses dehumidifiers to pull moisture out of the atmosphere. Then a drip irrigation system waters the adjacent garden, producing more than 2.500 heads of lettuce per week. The billboard was built by -- and advertises -- Lima's University of Engineering and Technology.

The Air Orchard is just one of several clever self-advertising projects the university has built to advocate engineering solutions to environmental issues. This

potable water generator

also pulls moisture from the air -- Lima's average humidity is around 80 percent year-round -- and turns it into drinkable water provided by a dispenser at the base.

Lima is the kind of town that doesn't mess around. As the second largest desert city in the world (behind Cairo), it has faced water problems for centuries. A new initiative by the city's water utility plans to

revive ancient stone canals

to bring water down from rivers in the Andes. It's something of a fixer-upper project: The canals were built by pre-Incan civilizations between 500 and 1,000 AD.

The concept of harvesting water with fog nets has been around a long time and some ambitious large-scale projects have been tested across the globe, most notably in

Chile

. A few years back, German design student Imke Hoehler proposed a design for portable and collapsible tent-like fog nets that could potentially harvest up to 20 liters of water per day under the right conditions.

Then there are the research projects that get

really, really small.

In March, a team of Japanese scientists proposed studying the microscopic workings of certain moisture-gathering plants to design the next generation of water collection systems. Electron microscope imagery reveals that such plants use cone shaped hairs to catch and store water, then change shape release the moisture in dry conditions. The team hopes advanced fiber technology could essentially replicate the process.

Global droughts and water shortages can seem like terrifying, insurmountable problems. But fear not. As with so many things in this world, William Shatner has our back. The actor and

sci-fi author

recently proposed a plan to pipe water from the Pacific Northwest to arid sections of California by way of -- well, the details are

still fuzzy

. But long-distance water pipelines have a

storied history

in the U.S. and several new projects are in various stages of proposal. And let it never be said that Shatner doesn't follow through: He recently launched the

Shatner Water

website, dedicated to exploring the issue.

Designed and built by the Washington-based engineering firm, Janicki Bioenergy, the very official-sounding Omniprocessor S100 uses heat from sludge to make water. A trial run is underway in Dakar, Senegal, where the machine -- which has received funding from the Bill and Melinda Gates Foundation -- is processing sewage from a community of about 100,000 people. The sewage is first heated intensely to dry it and then during the process, the water vapor is captured, heavily processed and turned into drinking water.