Idaho's Snake River Plain Aquifer Contaminated with Radionuclides

* Idaho National Engineering and Environmental Laboratory (INEEL) announced this week that the Snake River Plain Aquifer, which sits beneath INEEL, is contaminated with the radionuclide technetium-99. INEEL claims that the contamination poses no threat to human health. The technetium at INEEL is a byproduct of nuclear spent fuel reprocessing from naval reactors and can affect the thyroid.

No technetium has yet been found in Idaho's drinking water, but INEEL spokesperson Bryce Byram says, "INEEL scientists will continue to monitor ... and use that information as one of the many tools to make future cleanup decisions." The contamination stems from the Tank Farm at INEEL's Nuclear Technology and Engineering Center. The Tank Farm is comprised of eighteen underground tanks containing anywhere from 18,000 to 300,000 gallons of hazardous and radioactive liquid waste and 2.6 million curies of radioactivity.

The Tank Farm has been at the center of controversy recently, as the Department of Energy (DOE) has proposed reclassifying some of the tank waste so as to leave it in the tanks rather than clean it up. Although a federal court ruled against the proposal, DOE has appealed the ruling. Jeremy Maxand, of Snake River Alliance, Idaho's nuclear watchdog, says, "This would allow them to leave literally thousands of gallons of high-level extremely dangerous liquid waste above North America's second largest aquifer."

INEEL claims that the majority of the contamination is due to soil contaminated by leaks of technetium in transfer pipelines used when the tanks were being filled from 1956 to 1986. The Environmental Protection Agency says that nearly 80% of storage tank leaks are from pipelines and valves, rather than the tank vessel. However, DOE has not thoroughly investigated these leaks, claiming that the tanks are reliable.

INEEL says that while technetium levels are rising, levels of other radionuclides in the Snake River Plain Aquifer are steadily declining. Records indicate that the Aquifer also contains high levels of strontium-90, iodine-129, cesium-137 and tritium.

INEEL says that, due to natural attenuation, levels of strontium and iodine have decreased. INEEL does not indicate the amount of decrease, although activists are skeptical considering that as of 2001, strontium levels in the most highly contaminated areas of the Aquifer were ten times higher and iodine levels were 137 times higher than the federal Safe Drinking Water Act allows. Furthermore, it is estimated that tritium levels are 20 times higher than Drinking Water standards in the most highly contaminated areas of the Aquifer. However, long-lived radionuclides like plutonium have yet to infiltrate the Aquifer in large amounts.

In its 2001 report, Poison in the Vadose Zone, the Institute for Energy and Environmental Research suggested thorough cleanup, including solidification and removal of all tank wastes, before the damage to the aquifer is irreversible. The reports states, "Once the aquifer becomes contaminated at levels that exceed drinking water standards for long-lived radionuclides, the problem will be essentially irreparable. The technology for cleaning up large amounts of water contaminated with ... long-lived radionuclides to safe drinking water standards does not exist today."

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