Idaho Cleanup Project sees cleaner groundwater

The U.S. Geological Survey, in conjunction with the U.S. Department of Energy and the Idaho National Laboratory have released more than 30 years of water quality data.

Data collected at the DOE’s Idaho National Laboratory Site shows that long term trends indicate improved water quality in the eastern Snake River Plain aquifer.

“Just knowing that the water at the INL is safer and cleaner is really a good news story,” said Roy Bartholomay, manager of the USGS INL Project Office. “Statistically, when we look at the last 10 years of data, we see no trend. We believe that the engineering practices that are occurring at the facility are having a positive impact.”

USGS scientists analyzed data collected from 99 wells at the INL Site between 1981 and 2012. The study focused on wells possibly affected by waste water disposal that occurred from the early 1950s until the late 1980s at the INL Site.

Key findings include:
– Improved waste water disposal practices are helping to reduce concentrations of radionuclides such as tritium and strontium-90 in groundwater.

– Concentrations of the inorganic compounds sodium and chloride are decreasing at waste water disposal sites, but increasing farther down in the aquifer’s gradient. For example, chloride disposed of at the Idaho Nuclear Technology and Engineering Center in the mid-1990s has moved about 3 miles south where it was found at the highest concentrations in wells near the Central Facilities Area.

– There is an increasing trend for carbon tetrachloride, a volatile organic compound, at the Radioactive Waste Management Complex Production Well for the period 1987 to 2012. However, trend analyses of data collected since 2005 show no statistically significant trend, indicating that engineering practices designed to reduce movement of volatile organic compounds to the aquifer may be working.

USGS said it plans to optimize the monitoring well network as a result of the study, which could better prioritize use of equipment and resources.

“We’re going to be looking at optimizing our network to determine which wells we could eliminate from our program in the future and which constituents to discontinue sampling,” said Bartholomay.