April 17, 2013
Have you ever tasted a grain of salty baking soda in an otherwise a sweet cookie? That grain of baking soda could be classified as an emerging contaminant, as it has reached levels that were previously not at high enough levels to be noticed. As a society we have managed to develop infrastructure and sewage treatment plants for human waste, but there is new issue. There are certain materials that cannot be removed, and are accumulating in our water.These emerging contaminants, such as PCBs and nonylphenol, ingredients being used in industrial detergents, are being discovered in our waterways.
Analysis and removal of emerging contaminants in wastewater and drinking water.
As you might have been able to infer, an emerging contaminant is one that “is being discovered in water that previously had not been detected or are being detected at levels that may be significantly different than expected” as stated on the EPA website. These contaminants, which include human birth control and pesticides just to name a few, are interacting with our ecosystem, often causing adverse health issues in marine organisms. Although emerging contaminants are not as important as other water issues in the context of human health, it is tantamount to the health of the ecosystem that we fully identify what is going on in an attempt to mitigate these pollutants.
The problem with emerging contaminants is that it is not fully understood what the effects of certain unidentifiable pollutants are, but in the marine environment thus far, the effects have been adverse. Some EC’s, such as synthetic estrogen found in birth control that are not destroyed in the sewage treatment process, are released into the ocean and have been shown to cause serious problems for species in the water. According to the Southern California Coastal Water Research Project, in a recent project that assessed emerging contaminant effects on coastal fish, they discovered that “some [emerging contaminants] have been shown to cause endocrine disruption after being released to the environment, as they either mimic or interfere with the action of reproductive hormones such as estrogen and testosterone” (SCCWRP 2012). Because many of these contaminants that are entering the marine environment are not monitored by any existing programs due the difficulty in analyzing and quantifying them, not much is know about what the full effects may be on marine organisms and human health.
A program that has existed since 1986 called Mussel Watch, performed by NOAA, is using the success of their water quality monitoring system to further understand emerging contaminants and their effects on the marine ecosystem as well as their potential effects on humans. Mussels, which are a bivalve, filter-feeding species, bioaccumulate contaminants in their tissues and can be used as indicators of local contamination. The program analyzes native bivalves by extracting tissue and analyzing the samples with instruments. The concern is that if the emerging contaminants that so little is known about is disrupting the health of marine species, it may also be bioaccumulating in humans and having unknown adverse effects. We already know and are working to eliminate existing pollutants that are continuously being monitored, but what about the ones we don’t know about? The goal of this addition to the Mussel Watch project is to come to a better understanding of what exactly it is we may be dealing with in the future.
We are currently at a point where we are still identifying all of the different contaminants and what impacts and risks they create to us and our ecosystems. There are various methods of treatment which are can be integrated into pre-existing treatment plants. However, it is a difficult issue that is not fully understood, which makes implementation difficult. It is a step forward, though, that we are addressing these problems before they manifest themselves on a larger scale with other populations, including humans.
By Clayton Greene and Dana Handy
Mira Petrović, Susana Gonzalez, Damià Barceló. “Analysis and removal of emerging contaminants in wastewater and drinking water.” TrAC Trends in Analytical Chemistry. 2003: 685-696. Online Journal.
“Project: Southern California Mussel Watch.” SCCWRP. N.p., 17 Apr. 2012. Web. 05 Apr. 2013. <http://www.sccwrp.org/ResearchAreas/Contaminants/ContaminantsOfEmergingConcern/SouthernCaliforniaMusselWatch.aspx>.
Terry L Wade, José L. Sericano, Piero R Gardinali, Gary Wolff, Laura Chambers. “NOAA’s Mussel Watch project: Current use organic compounds in bivalves”.Volume 37, Issues 1–2, January–February 1998, Pages 20-26. Marine Pollution Bulletin.
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.