Toxic Chromium Found in Regional Aquifer

* Toxic Chromium Found in Regional Aquifer

Elevated levels of toxic chromium VI were identified in the regional aquifer beneath the Los Alamos National Laboratory (LANL). A recent report, which LANL was required to submit to the New Mexico Environment Department, states that concentrations of chromium VI were found in the regional aquifer which are eight times greater than the state standard, and four times greater than the federal standard. The report asserts that the chromium contamination has not been detected in Los Alamos County drinking water wells.

In December 2005, LANL reported finding elevated levels of chromium in a regional characterization well. The New Mexico Drinking Water standard is 50 parts per billion (ppb). The Environmental Protection Agency standard is 100 ppb. Between January 2004 and December 2005, the detected chromium levels nearly doubled from 270 ppb to 405 ppb.

LANL used chromium compounds to reduce corrosion in power plant cooling towers and other activities. Chromium was discharged by LANL into Los Alamos, Sandia and Mortandad canyons. The releases began in the 1950s and were suspended in the mid 1970s.

Chromium is a hard metal. It occurs in nature and is found in plants, soils, and at low levels in groundwater. There are two forms of chromium that are important at LANL: chromium III and VI. Chromium III is known to positively contribute to health. Chromium VI is toxic and a major concern to public health. It was the controversial toxin portrayed in the Hollywood production Erin Brockovich.

The presence of chromium contamination in the regional aquifer threatens drinking water. Los Alamos County relies on the regional aquifer for 100 percent of its drinking water. The EPA has found chromium VI to be toxic, even from brief exposure. If ingested, chromium VI can be lethal. It causes stomach upset, ulcers, convulsions and kidney and liver damage. External exposure can cause ulcers on the skin, rashes and nerve damage.

Bob Gilkeson, a registered geologist who originally worked on the well drilling project as a contractor for LANL, is concerned that the investigation detailed in the report does not adequately address the situation at hand. He said, LANL has no plans to install new wells in the regional aquifer, instead the new wells will monitor the water in perched zones of saturation located above it.

Likewise, he found that the proposed testing will not determine how high the level of contamination may be. LANL intends to take samples every three months, but as the contamination levels continue to rise, Gilkeson recommends that the wells be continuously pumped and sampled until the highest level of the contamination can be determined.

Gilkeson said, "We know the contamination level is high and the concentrations are growing with each sample. We know that the contamination is located in aquifer strata, which will allow it to travel quickly, but we do not know how close the contamination plume is to drinking water wells. Gaining the necessary knowledge requires the installation of new monitoring wells in the regional aquifer. It is very important to prevent the chromium contamination from reaching the precious drinking water wells."

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