Operating from 1952 to 1992, the Rocky Flats nuclear weapons facility was located approximately 15 miles northwest of Denver, a city built by an influx of miners during the gold rush in the nineteenth century. During the years of its operation, the plant constructed more than 70,000 triggers for nuclear bombs. Rocky Flats would be the site of two major secret plutonium fires, blowing radioactive poison into sections of Arvada and Denver in 1957 and 1969. Hundreds of smaller fires also took place, as well as regular leaks, spills, and atmospheric plutonium releases. Plutonium clouds blew over houses, swimming pools, schools, churches, farms, fields, and streams. Rocky Flats is known for powerful Chinook winds — winds that would blow plutonium dust into local neighborhoods. Locals did not know that Rocky Flats was a weapons factory for most of its years of operation. Workers employed there were forbidden to speak of their work and often didn’t comprehend the full extent of the factory’s activities.
By 1989, The FBI and EPA suspected criminal negligence at Rocky Flats, which led to a raid, led by FBI agent Jon Lipsky. A federal grand jury began an investigation, a settlement was negotiated, the court documents were sealed, and the plant closed. The story of this federal grand jury is fraught and complex, and cover-ups are suspected in the sealing of the documents and lack of full prosecution. The Rocky Flats cleanup was officially completed in 2004; however, numerous scientists, nuclear experts, local citizens, and antinuclear activists argue the cleanup is far from finished. Unknown but large amounts of plutonium and other contaminants remain on the land in what has been turned into a Superfund site, a designation made under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980. The primary industrial site (the Superfund area — 485 acres) was never completely remediated. There is a buffer zone, also heavily contaminated, although the EPA claims this area is fully remediated. The surrounding area, now called a National Wildlife Refuge, was not remediated. Significant contamination has been detected there in the soil and groundwater. Many other toxic and radioactive contaminants have also been found at Rocky Flats in addition to plutonium: americium, uranium, cadmium, PCBs, beryllium, and more. A 2019 study found plutonium “hot particles” in the soil frighteningly close to the homes abutting the Flats.