Desalination is Helping San Diego Avert Drought. Is the Technology Useful Elsewhere?

San Diego County has long faced drought conditions. But a new desalination plant has changed all that, allowing the area to get 50 million gallons of fresh drinking water everyday, or enough to serve 400,000 people and 10 percent of the area’s water supply.

California, of course, has suffered through what seems like an endless drought. The result has pitted interest groups against one another for access to available supplies. But the problem is particularly felt around the world, especially in the Middle East and Africa.

As environmental concerns grow over greenhouse gas emissions and water needs rise, cleaner options that have large-scale applications are necessary. The need is paramount. The demand for drinking water grew six-fold in the 20th century and is expected to increase another 40 percent by 2025, the United Nations says.

According to the UN, 1.1 billion people don’t have access to water and another 2.6 billion don’t have access to safe sanitation. The problem is compounded because only 0.5 percent of earth’s water is directly suitable for human consumption. The rest is composed of saltwater or locked up in glaciers and icecaps. But is desalination the answer?

Regarding San Diego, “The water from the Carlsbad plant is truly the only drought-proof supply available to San Diego, it is not dependent on local rainfall or snowpack in the Sierras,” said Graham Beatty, Poseidon Water Director, project management and finance. “Poseidon is committed to providing sustainable, fresh and clean drinking water to San Diego in an environmentally responsible manner.”

Advocates are touting the technology’s ability to create drinking water out of seawater and to avoid diverting fresh water supplies from rivers and streams. Opponents of the method, however, are saying that the conversion process uses great amounts of fossil fuels and that it harms marine life through its vast duct system whereby it pipes water into the desalination facilities. Those plants then dispense other toxins back into the ocean.

But the Carlsbad Desalination Plant is necessary to guard against droughts and the influx of new citizens who will increase the demand for fresh water. That’s why the Sandia National Laboratory has written a roadmap that would use desalination to increase the nation’s drinking water supply.

“By 2020, desalination and water purification technologies will contribute significantly to ensuring a safe, sustainable, affordable, and adequate water supply for the United States,” the federal lab says.

Cost, it adds, has been the biggest obstacle to development, noting that it is much more expensive to purify seawater than it is to treat fresh water. As for the Carlsbad Desalination Plant, it is a public-private partnership between the local water authority and Poseidon Water, which developed the project. 

Applicable elsewhere in the world? The International Desalination Association says that 300 million people around the globe get their water using such technology. But if concerns exist over using fossil fuels to purify the seawater, what about using nuclear energy? 

The Atomic Energy Agency says that nuclear energy is the most feasible method. It points out that the technology of coupling nuclear energy and desalination plants already has taken hold in Japan and Kazakhstan, where commercial facilities have been operating since the 1970s.

India is among countries seeking to expand the base of national and international experience through a demonstration plant it is building. Altogether, the agency is working with 20 nations to advance nuclear science and desalination.

It is estimated that a 300-megawatt nuclear plant would be required to drive a desalination facility with a capacity of 1 million cubic meters of potable water a day. That’s enough water to support a population of between 3 or 4 million people. That same population would require between 4,000 and 6,000 megawatts of installed capacity to meet its electricity needs.

Authorities around the globe are making dire predictions: the effects of climate change and reduced access to safe drinking water supplies are on collision course — something that would affect the well-being of billions of people all over the planet. Greater conservation and efficiencies are a must. But so are the development and implementation of clean technologies that can desalt seawater.