Great Western Reservoir helped make Broomfield's growth possible. But its location immediately downstream from Rocky Flats also made it part of Colorado's nuclear history. After plutonium and tritium associated with the plant were detected in the watershed and reservoir, Broomfield ultimately replaced Great Western as a drinking-water source. Today, plutonium remains in its sediments.

After the 1989 FBI raid halted plutonium production, Rocky Flats underwent an accelerated cleanup that reached physical completion in 2005. More than 800 structures were removed, but the cleanup did not eliminate all contamination. What remained, how were the decisions made, and why does Rocky Flats still require long-term environmental stewardship?