Laboratory results indicate water from the alternative water supply system is safe for residents to drink

The U.S. Department of Energy announced today that residential drinking water testing from an alternative water supply system in Riverton, Wyoming, confirmed the water is safe. Results from water samples collected on May 3, 2012, show that uranium levels at 0.0001 milligrams per liter, well below the drinking water standard set by the U.S. Environmental Protection Agency.

“We take the issue of potential water contamination very seriously and are pleased we can reassure residents that their drinking water is safe,” said April Gil, DOE Riverton site manager. “These results are especially encouraging because they are consistent with uranium values from all the previous years of sampling the alternative water supply system, adding to their credibility.”

On May 2, Department officials learned that water samples from four residences, conducted by the Northern Arapaho Utility Organization (NAUO) in October 2011, had tested positive for high concentrations of uranium. DOE responded immediately by delivering bottled water to the affected residents and maintaining their bottled water supply until additional samples could be collected, analyzed, and verified as safe.

DOE and the Wyoming Department of Environmental Quality re-sampled water at each residence the following day and sent those samples to ALS Environmental – an independent, EPA-approved laboratory that is audited by DOE annually – for analysis using standard quality assurance protocols. The Energy Department reviewed the laboratory reports to ensure the data were valid before releasing the final results today, and is working with NAUO and its laboratory to try to determine the validity of the data from October.

The DOE Riverton Uranium Mill Tailings Radiation Control Act Title I site, located on the Wind River Indian Reservation in central Wyoming, processed uranium ore from 1958 to 1963. While there are no tailings disposal cells at Riverton, historical ore processing resulted in contamination of the shallow groundwater. DOE selected natural flushing for remediation of the site groundwater, which was approved by the U. S. Nuclear Regulatory Commission. In 1998, DOE and Indian Health Services jointly funded installation of the alternative water supply system, which provides residents living near the Riverton site access to safe drinking water. The has a cooperative agreement with the Northern Arapaho Tribe to ensure that the alternative water supply system remains a viable institutional control at the Riverton processing site. 

The data validation and laboratory reports are available on the DOE Office of Legacy Management website.

May 10, 2012: Data Review and Validation Report of May 3, 2012, Sampling Event
ALS Environmental Laboratory Report on May 3, 2012, Sampling Event

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