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ShareJanuary 1, 2008 — Seismologists have tested a new way to measure the concentration of the dangerous groundwater contaminant Trichloroethylene (TCE). Ultrasonic waves called P-waves are sent through ground containing water that may be laced with TCE. The presence of TCE can be detected by measuring reductions in P-wave velocities. Seismic detection can be combined with ground penetrating radar to reveal the location of dense liquid pollutants where remediation is needed.
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The same seismic waves picked up by a seismometer during an earthquake now has a new use -- finding problems at the source of your drinking water.
Like a scene from Erin Brockovich, these scientists are searching for contaminants in ground water that may cause cancer. Looking for amounts of trichloroethylene, or TCE, even smaller than a needle in a haystack.
“If you were to take this amount of TCE that we have here could contaminate an Olympic swimming pools worth of water,” Jil T. Geller, Ph.D., UC Berkeley, told Ivanhoe.
Geophysicists and earth scientists from the Lawrence Berkley National Lab have a better way of locating that contamination. Here trouble does come in waves.
“If we inject a liquid contaminant, will we see it change in the signature of the acoustic or seismic wave,” Dr. Geller said.
That change in the returned seismic wave reveals the exact location of the contaminant -- even if it is only microscopic amounts.
“Currently what's done is they punch many many many bore holes into a site and sample and analyze very slow and very time consuming, they turn some of these sites into Swiss cheese basically," Dr. Geller said.
This new technology may change the way spills and leaks are cleaned up, changing the cost most of all.
"You want to get to the source and to get rid of the source, instead of treating 10 olympic pools of water you can go to the source and remediate that," Dr. Geller said.
“One way to do that is to put seismic sources in one well and receivers in the other and we try to image what the earth looks like in between them.” Jonathan Ajo-Franklin, Ph.D., UC Berkeley, told Ivanhoe.
These cables can be dropped up to 6,000 feet below the Earths surface.
“Its called an electric crystal, where if you squeeze it causes a change in voltage, we record those changes of voltage back up on the surface.” Dr. Ajo-Franklin said.
Seismic technology tested here in the US -- but the benefits may someday have a global impact.
WHAT IS HAZARDOUS WASTE? In the U.S., hazardous waste is defined as any discarded solid or liquid that is highly corrosive, toxic, reactive enough to release toxic fumes, or easily ignited. It can include solvents, pesticides, and spilled chemicals -- including acids, ammonia, chlorine bleach and other industrial cleaning agents -- as well as most heavy metals.
Long-term exposure to hazardous waste can lead to chronic respiratory diseases such as asthma, damaged liver and kidneys, or cancer. Poisoning and chemical burns can result from contact with even small amounts of toxic chemical waste. Even brief exposure can cause headaches, dizziness, and nausea.
Even non-hazardous, organic human waste that is not properly managed can be a serious health hazard, since it ferments and creates a good environment to let bacteria and other germs grow. The waste also attracts flies, rats, and other creatures that become infected and can spread infectious diseases, including malaria and plague.
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