Radioactive waste cleanup paying off for giant Idaho aquifer

摘要

Radioactive and chemical contamination in a giant aquifer below an eastern Idaho federal nuclear facility has decreased or remained constant in recent years, scientists say. A report released earlier this year by the U.S. Geological Survey attributes the decreases to radioactive decay, changes in waste-disposal methods, cleanup efforts and dilution from water coming into the Lake Erie-sized Eastern Snake River Plain Aquifer. "The overall aquifer is looking pretty good compared to what it used to be," said Roy Bartholomay, a USGS scientist and one of the report's authors. "But we still have a few of these wells that keep us scratching our heads." The report said contamination levels at all but a handful of nearly 180 wells are below acceptable standards for drinking water as set by EPA. The contamination originated at an 890-square-mile Department of Energy site that includes the Idaho National Laboratory, considered the nation's leading nuclear research lab. The 2016 to 2018 study tracked water quality in the aquifer that supplies water to cities and farms in the region. It's part of an ongoing monitoring program that started in the 1960s. There are a handful of wells that continue to have concentrations of radioactive elements above drinking water standards, but they are near nuclear facilities. The report noted that the number of wells failing to meet drinking water standards has decreased from a similar study three years ago. The nuclear site started operating in the late 1940s under the Atomic Energy Commission, a forerunner to the Energy Department, and contamination of the aquifer began in 1952, according to the report. Contamination reached the aquifer through injection wells, unlined percolation ponds, pits into which radioactive material from other states was dumped, and accidental spills mainly during the Cold War era before regulations to protect the environment were put in place.