USC Dana and David Dornsife College of Letters, Arts & Sciences > Blog

October 10, 2011

California Desalination

As global population continues to rise, the amount of freshwater available for human consumption becomes an increasing issue. Though sources are rapidly depleting, the United States in general has yet to understand the importance of conserving water.

For coastal states such as California, an alternative means to obtaining freshwater is right at their disposal: the ocean.

The spotlight on desalination has been glowing brighter in recent years, as researchers debate on whether or not it is an adequate provider of water for the public. But while desalination provides a new source of freshwater, the environmental and monetary costs outweigh the potential benefits considering the lack of focus on conservation in California.

As far as the environment goes, negative effects of desalination are far too great at this point; the debris left over from distilling the water is put back into the ocean, increasing salinity and killing off biodiversity that is not adapted to such high levels of salt. According to David Rosenfeld, “desalination plants have the potential to entrap sea lions, millions of fish and other marine life,” their environmental impacts also including “the heavy concentrates of salt and the remains of other chemicals that could be dumped into the ocean,” as he writes in his article, Conservationists Push Back Against Desalination in California. When species all around the world are already rapidly declining due to anthropogenic reasons, consciously decreasing ocean biodiversity is not the answer to finding more sources of freshwater.

In addition, desalination is an extremely energy intensive process. Rosenfeld furthers his argument to say that desalination has a massive carbon footprint—around 40 percent of the operating cost is the cost of electricity used to power to plant.

Even while the issue of wasted energy can be mitigated with improved technology, the biodiversity lost cannot be replaced, and the costs put into the additional technology renders the whole business impractical.

While desalination seems like one of the only options for increasing our freshwater resources, in addition to the environmental degradation, it is currently not economical. A proposed plant in Carlsbad is estimated to cost $700 million dollars and will satisfy only 8% of San Diego’s water needs. For this 8% of the water supply it will use as much electricity as 45,000 homes, which is an additional recurrent operating cost on top of the $700 million. The amount of energy required for desalination is extremely high and will be very costly. The cost of water from the desalination plant will be tied to the cost of energy and as the price of energy rises, so will the price of water. “The Public Utilities Commission has approved a plan to allow publicly traded California American Water to potentially quadruple water bills on 40,000 ratepayers in order to pay for the proposed plant,” writes Rosenfeld. Consumers are unaware that the cost of desalination plants will be passed on to them, which is why they are cost-effective for the owners of the plant.

In terms of the allocation of state money, while our education system struggles on budget cuts, Proposition 50 (passed in 2002) provide $50 million to support desalination projects. This year, the Metropolitan Water District of Southern California reduced its conservation to $10 million while allocating $350 million for the Carlsbad desalination plant and promising $250 per acre-foot of fresh water produced to future desalination plants. Rather than spending tons of money on desalination plants that are harmful to the environment, we should first focus on maximizing conservation. While at some point, desalination might be necessary for human survival, we should increase our conservation first: “In parts of Southern California, up to 70 percent of all household water is used outdoors, mostly to water lawns, and an estimated 1.3 billion gallons of wastewater drains into the ocean each year” (Rosenfeld). Southern California is a desert and people living here need to accept that they cannot have a green lawn. If you want a green lawn, move to Northern California or Oregon. Otherwise plant some native plants that don’t need as much water and stop exploiting our water resources just to have a pretty front yard. In terms of in house conservation, low-flow toilets and showerheads, efficient washing machines and dishwashers could all be made extremely affordable if state subsidies were reallocated from desalination plants to conservation technologies.

Desalination plants cause too much environmental degradation and are too expensive to be implanted when there so much there is so much left to be done as far as conservation. We can reevaluate the need for desalination plants when excessive water use has been reduced significantly.

Bibliography: http://www.dcbureau.org/20110303169/natural-resources-news-service/conservationists-push-back-against-desalination-in-california.html

About the authors: Leslie Chang and Lauren Taymor are working towards their bachelor degrees in the USC Dornsife College of Letters, Arts and Sciences.