Rocky Flats Plant

Rocky Flats Plant
U.S. National Register of Historic Places
U.S. Historic district
July 1995
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Location	Jefferson County, Colorado
Nearest city	Arvada, Colorado
Coordinates	39°53′N 105°12′W / 39.89°N 105.20°W / 39.89; -105.20
Area	175.8 acres (0.711 km2)
Built	1952
Built by	Austin Construction Co.
NRHP reference No.	97000377[1]
Added to NRHP	May 19, 1997

The Rocky Flats Plant was a United States manufacturing complex that produced nuclear weapons parts near Denver, Colorado.^[2] The facility's primary mission was the fabrication of plutonium pits,^[3] the fissionable part of a bomb that produces a nuclear explosion. The pits were shipped to other facilities to be assembled into complete nuclear weapons.^[4] Operated from 1952 to 1992 by private contractors, Dow Chemical Company, Rockwell International Corporation and EG&G, the complex was under the control of the U.S. Atomic Energy Commission (AEC), succeeded by the Department of Energy (DOE) in 1977. The plant manufactured 1,000 to 2,000 pits per year.

Plutonium pit production was halted in 1989 after EPA and FBI agents raided the facility^[5] and the plant was formally shut down in 1992. Rockwell then accepted a plea agreement for criminal violations of environmental law.^[6] At the time, the fine was one of the largest penalties ever in an environmental law case.^[7]

Cleanup began in the early 1990s,^[8][9][10] and the site achieved regulatory closure in 2006.^[11] The cleanup effort decommissioned and demolished the entire plant, more than 800 structures; removed over 21 tons of weapons-grade material; removed over 1.3 million cubic meters of waste; and treated more than 16 million US gallons (61,000 m³) of water. Four groundwater treatment systems were also constructed.^[12] The site of the former facility consists of two distinct areas: the "Central Operable Unit", which remains off-limits to the public as a CERCLA Superfund site, owned and managed by the U.S. Department of Energy,^[13] and the Rocky Flats National Wildlife Refuge, owned and managed by the U.S. Fish and Wildlife Service.^[14] Every five years, the U.S. Department of Energy, U.S. Environmental Protection Agency, and Colorado Department of Public Health and Environment review environmental data and other information to assess whether the remedy is functioning as intended.^[15] The latest Five-Year Review for the site, released in August 2022, concluded the site remedy is protective of human health and the environment. However, a protectiveness deferred determination was made for PFAS.^[16]