October 10, 2011
Our entire world runs off of water. Everything from the food we eat, to the paper we draw on, we are dependent on a consistent source of freshwater. That’s why, with our population doubling every fifty years, fresh water is starting to become an area of concern. This new issue has scientists and governments searching for alternatives to help save the water supply before its too late. Some alternatives have been extremely successful such as the water recycling taking place in Fountain Valley, California, while others such as desalination have proven both costly and harmful to the environment.
Desalination is the process of removing salts and other minerals from water that is otherwise harmful to the human body and biosphere. While desalination may seem like a major hope the future, the current processes we use to remove these salts have been extremely energy abusive and economically unfeasible. In order to convert seawater to drinking water, desalination requires having a major source of energy. Due to the massive amounts of energy used, the price of water increases over twenty five percent to that of water taken from aqueducts. The average acre of freshwater costs approximately $700, while the same area of desalinated water can cost upwards of $950.
Another major cost associated with the conversion of seawater to fresh water is the need to pump water from the sea to areas of use, sometimes lifted over 2000ft. In many cases, it is much more efficient to reroute water from an aqueduct than it is to pay the bills associated with lifting the water. While the economics behind desalination are extremely high, the environmental impact is also costly.
Desalination removes vital nutrients from our local waters, not simply at the microbial level, but as well as larvae and other organisms. There isn’t a way around this, simply because the intake of any seawater to be used in desalination will contain these important nutrients. Once the process of desalination has occurred, the remaining salt must be disposed of and in most cases that is back into the ocean where it increases salinity of our costal ecosystem that is already plagued by both urban and agricultural runoff. While the salty byproduct, can be diluted in other flows of water into the oceans such as runoff or output from treated sewage water, the negative affect from the intake outweigh the benefits of an increased freshwater supply.
Food & Water Watch advocates for better fresh water management practices. “Ocean desalination hides the growing water supply problem instead of focusing on water management and lowering water usage.” A key issue to focus on is the overall water usage of the population in southern California. With the growing need for freshwater, desalination may not quench southern California’s increasing thirst for freshwater. The environmental implications of desalination surpass the fiscal benefits water companies stand to gain and undoubtedly allow for further degradation of our costal ecosystems while not addressing overall water conservation.
About the authors: Lucas Biging and Nick Leonard are working towards their bachelor degrees in the USC Dornsife College of Letters, Arts and Sciences.