The 6,240-acre Rocky Flats Plant (USDOE) site is located about 16 miles northwest of Denver and 10 miles south of Boulder, Colorado. The Rocky Flats Plant operated from 1952 until 1989 as part of the United States� nationwide nuclear weapons complex. The facility manufactured trigger mechanisms for nuclear weapons from various radioactive and hazardous materials. Manufacturing activities, accidental industrial fires and spills, support activities, and waste management practices contaminated soil, sediment, groundwater and surface water with hazardous chemicals and radioactive constituents.