February 27, 2012
A few centuries ago, water use was not a problem because it was seen as a renewable resource that can never be overexploited. However, as population growth increases exponentially, water use likewise increases, depleting water resources at an unsustainable rate. As we use groundwater and surface water at a rate faster than their replenishment rate, we must look towards other sources to obtain water. One proposed solution is desalination, a process that removes salt from saline water. There are three techniques associated with desalination: electrodialysis, freezing, and reverse osmosis. Electrodialysis uses porous members to remove positively and negatively charged salt ions; freezing, by default, removes salt from ice; and reverse osmosis is a process that pressurizes salt water so that water flows through a membrane while the remaining salt are retained (Desalination Process).
Desalinization, while is considered an alternative water supply, has its fair share of negative environmental impacts that could potentially harm large communities of marine organisms. First, the discharge from the desalination facilities carries saline water back into the ocean, which affects benthic organisms that are not accustomed to water with such high salinity. Similarly, discharged water can contain chloride, heavy metals, and cleaning chemicals that would foul ocean water and poison marine animals.
Furthermore, the power consumption required for the process of desalination consumes fossil fuels, which leads to carbon dioxide emissions. As known, carbon dioxide has detrimental effects on the environment, including warming of the earth and human health risks.
Desalination also requires an extensive amount of energy to work. If desalination were to produce half of America’s water, the United States would need to construct 100 more electric power plants (Why Desalination Doesn’t Work). And the energy cost of consuming the necessary amount of energy to produce usable water would exceed the cost to pump water from aquifers or to import the water. Therefore, desalination is not a very cost-effective method and should be used with caution.
In one example, Huntington Beach has proposed desalination in order to provide water to their community. This desalination facility, if successful, would provide 50 million gallons of drinking water per day (Proposed Desalination Plant Wins Permit). However, opponents criticize desalination as energy-intensive and expensive. Furthermore, the construction of the facility near a popular beach would inevitably harm aquatic organisms, which could reduce tourism and recreation.
While it’s necessary to address the current water crisis and some may claim that the damage to marine organisms is insignificant in comparison to the benefits to society, desalination conflicts with the energy-crisis, which would mean that through desalination, we are essentially trading one problem in for another. Especially since most desalination plants require the use of fossil fuels, desalination would exacerbate the energy-crisis, depleting energy resources from other uses.
Despite their criticism, opponents do acknowledge the current water problem, so they propose alternative solutions, including improving irrigation systems and requiring new homes to be water-efficient. These solutions are more focused on conservation of water, which can help communities be more conscientious of their water usage and supply more water to each individual.
Kaylee Yang and Marc Chua are undergraduates in the USC Dornsife College of Letters, Arts and Sciences.
February 8, 2012
In 2009, concerns over the lack of water availability in California dramatically escalated—the issue was named by Arnold Schwarzenegger, the governor at the time, as a statewide emergency. Some even believed that following two “critically dry years,” the year 2009 became the most “severe drought year in California history” (water.ca.gov). However, a winter of persistent snowstorms brought close to 61 feet of snow to the Sierra Nevada’s, 143% of normal levels and the second highest levels the state has ever seen (Huffington Post); the drought was over. Today, it is apparent that we need not focus our immediate concern on the California drought, as California remains in the clear and consistently is a victim of this repetitive drought cycle–our history proves that drought in California is nothing new. Instead of focusing on the dry conditions, it is important that we realize our anxiety is a result of water crisis issues that need our attention: California’s aging water infrastructure, its immensely growing population, and the new prospect of climate change. These issues make up the true water emergency faced daily by Californians.
Looking back at California’s drought history proves several points about the state and droughts. First, California is no stranger to droughts. Over the past 35 years, the state has experienced 3 major droughts, one being the most severe ever recorded. Second, the state has been able to respond strongly to survive a drought through statewide policy and conservation efforts. California’s government has taken the necessary steps and measurements to sustain itself and prepare for future droughts. Third, droughts are a normal phenomenon that should be expected in California. The reason droughts have occurred is due to the climate of the region that tends to fluctuate between wet and dry cycles, meaning droughts are inevitable. Thus, if droughts are to be expected they should not be the biggest concern in California, but rather other issues that influence the water crisis in the state, like its aging water infrastructure.
California’s water infrastructure is critical for supplying water for agriculture, the population, and environmental protection throughout the whole state. Lately, these variables have caused a rise in water demand that the current infrastructure cannot support, mainly because it is aging. The major component of the infrastructure is the Sacramento-San Joaquin River Delta which has weak, aging levees that, if broken, can drastically jeopardize the state’s water distribution for vital use. If major investments aren’t made to upgrade the aging infrastructure in the future, California won’t be able to sustain itself through drought at a time when climate change and population growth in the state exacerbate the growing water crisis.
California is relentless when it comes to growing population numbers. In 1900, California housed about 1.4 million people, and today, according to the 2010 Census, has close to 38 million people. This immense jump has placed much strain on the infrastructure of the state and contributes to the environmental issues–such as climate change–now plaguing the surrounding ecosystems. The main contributors to climate change are exacerbated by human activities, such as burning fossil fuels to produce carbon dioxide. Climate Change is creating a huge problem for California’s water sources, as seen through changes in sea level, snowpack, and river flows. According to the California Department of Water Resources, scientists predict our Sierra Nevada snowpack, which provides one-third of our water resources, to lose approximately 20 percent of its volume. This, along with the increasing population, will soon become a huge contributing factor to the California drought pattern, and needs to be addressed immediately.
Caroline Smith and Sergio Avelar are undergraduates in the USC Dana and David Dornsife College of Letters, Arts and Sciences.
October 10, 2011
Due to a growing population, frequent droughts, and the effects of climate change, it is becoming more and more challenging for California to provide enough water to meet the demands of its citizens. Even with increased conservation and reuse, traditional water sources might not be sustainable in the future. Currently, California is experimenting with desalination, a process that removes salt and other minerals from seawater, as a possible solution to the water crisis. However, current desalination technology is extremely energy intensive, contributes to global warming by emitting greenhouse gases, and poses a severe threat to marine environments. Despite California’s water issues, the combined environmental effects of desalination are too severe for the process to be considered a viable alternative water source until desalination plants can operate in a way that minimizes their impact on the environment.
According to Peter Hanlon in the article “Desalination Nation” from The Huffington Post, desalination uses eight times more energy than groundwater pumping. Hanlon describes how this process creates that he calls an “energy-water nexus”: “In short, generating electricity requires a lot of water as does treating and moving water. Desalination does not help to ease the burden of these interconnected demands, in fact it makes the situation worse.” Electric grids require a lot of water for cooling, and the amount of water produced by desalination may not be enough to compensate for the water and energy used to create it.
An additional problem caused by increased energy use is increased air pollution, which can contribute to the global climate change. Planned desalination plants will be located alongside existing power plants, potentially propelling greenhouse gas emissions (Food & Water Watch). Considering the current climate crisis, a process that uses so much energy and increases pollution may not be sustainable in the long term.
The greatest threat to the environment from desalination plants is their potential impact on marine life. According to the report Evaluating Environment Impacts of Desalination in California by Holly Alpert, Catherine Borrowman, and Dr. Brent Haddad, during the desalination process, seawater is withdrawn directly from the ocean, trapping fish and macroinvertebrates against a screen; smaller organisms that get through the screen, like plankton, invertebrates, and eggs and larvae of fishes, are killed once in the facilities. The effect of this process can be illustrated by a study of a San Onofre power generation facility that uses a similar open intake method: It was found that 4.4 million fish, of 61 different species, were trapped by the open-water intake screens in 2004, which caused a 60% decrease in fish populations within one kilometer of the facility (Alpert, Borrowman, and Haddad). Not only can the size of the population be affected, biodiversity may also be reduced by desalination causing fundamental changes in the ecological processes of the given ecosystem.
Unfortunately, the open ocean intake technology of desalination plants is not the only part of the process that can significantly impact healthy fish populations near the facilities. The disposal of wastes poses an additional threat to marine environments. After desalination, a heavily concentrated brine solution is left over. Currently, all desalination facilities in the world discharge this brine solution, containing double the salt of natural seawater as well as various chemicals, directly into the ocean (Alpert, Borrowman, and Haddad). The balance between marine life and their environment is delicate. Some organisms may be able to withstand an increase in salt, but most would not survive.
Ideally, desalination would be eliminated as a possible alternative water source, and efforts would instead be focused on increasing conservation, sustainability and recycling. However, California has already implemented legislation to allow for the construction of various plants along the coast. Therefore, the important issue now is to make sure that the plants are not allowed to operate until they do an Environmental Impact Assessment and comply with the California Water Code so that desalination has the least possible impact on the environment.
About the authors: Katherine Moreno and Madi Swayne are working towards their bachelor degrees in the USC Dornsife College of Letters, Arts and Sciences.