The Idaho National Laboratory (INL) was established by the U.S. Atomic Energy Commission, now the U.S. Department of Energy (DOE), in 1949 to build, operate, and test nuclear reactors. The scope of work at the INL increased from the 1950s through the 1970s to include other nuclear-research programs, the reprocessing of spent nuclear fuel, and the storage and disposal of radioactive waste. A history of more than 50 years of waste disposal associated with nuclear-reactor research and nuclear-fuel reprocessing at the INL has resulted in measurable concentrations of contaminants in the eastern Snake River Plain (ESRP) aquifer beneath the INL.