DEVELOPMENT & LAND USE

A recorded 2016 City of Arvada development agreement required Candelas homebuilders to provide homebuyers with a Contiguous Area Report discussing the former Rocky Flats nuclear weapons facility immediately north of the community. Buyers were required to sign the report, and signed copies were to be recorded. The documents also raise another question: what happens to that disclosure when a home becomes a rental?

In 1979, the U.S. Department of Housing and Urban Development issued a Rocky Flats Advisory Notice informing certain prospective homebuyers near the nuclear weapons plant about off-site plutonium contamination and a radiological emergency-response plan. The federal warning offers a striking glimpse into what residents were told about Rocky Flats—and raises questions about how that information changed over time.

On Mother’s Day 1969, plutonium caught fire inside Rocky Flats Buildings 776/777. Firefighters battled the blaze for hours as portions of the filtration system were damaged and plutonium escaped. The accident became a turning point—bringing questions about contamination from the secretive nuclear weapons plant into public view.

On September 11, 1957, a plutonium fire at Rocky Flats spread into the building's filtration system, allowing radioactive material to escape into the atmosphere. Decades later, Colorado researchers reconstructed the accident and mapped how airborne plutonium may have traveled across surrounding communities.

The discovery of Rocky Flats-derived plutonium in air-filter samples collected along Indiana Street has renewed concerns about plans to expand the Rocky Mountain Greenway trail system near the former nuclear weapons plant. The Rocky Mountain Greenway Project began in 2016 as an effort to connect three national wildlife refuges—Rocky Mountain Arsenal, Two Ponds and Rocky Flats—through a regional trail network. Plans include an underpass connecting the Rocky Flats National Wild

In April 2018, CBS Colorado reported that several Colorado school districts had prohibited school-sponsored field trips to the Rocky Flats National Wildlife Refuge, the site surrounding the former Rocky Flats nuclear weapons plant. The Denver Public Schools Board brought forward a resolution prohibiting its nearly 100,000 students from participating in field trips to the refuge. Board members cited concerns that visiting the former nuclear weapons site posed too great a risk

In January 2012, longtime Rocky Flats researcher and activist LeRoy Moore and photographer Robert Del Tredici published an opinion piece in the Boulder Daily Camera titled “Plutonium is forever.” Moore later preserved the article on his Rocky Flats blog, where it remains available today. More than a decade later, the piece provides an important historical perspective on concerns surrounding Rocky Flats, the proposed Jefferson Parkway and opening the Rocky Flats National Wildl

In 2012, LeRoy Moore and Robert Del Tredici published “Plutonium is forever,” an opinion piece raising concerns about residual plutonium contamination, the Jefferson Parkway and public recreation at Rocky Flats. More than a decade later, the article offers a historical perspective on questions about soil disturbance, public access and long-term stewardship that continue to surround Rocky Flats today.

New warning signs at the Rocky Flats National Wildlife Refuge are drawing renewed attention to the site’s nuclear history. Installed in response to public requests, the signs warn of radioactive materials and raise a larger question: how should visitors be informed about the history and continuing concerns surrounding land that once formed part of the Rocky Flats nuclear weapons complex?

On March 17, the Lyons Board of Trustees voted 6–1 to oppose construction of the Greenway through the refuge and its connection to regional trails. Lyons joined Broomfield, Superior and Westminster, which had previously withdrawn their support for the project.

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.

Decades before homes were built at Candelas, members of the Church-McKay family sued over radioactive contamination of property near Rocky Flats and its effect on land use and value. Years later, Charles Church McKay became a developer of Candelas. The documented history connects Rocky Flats contamination, litigation and modern development in ways many current residents may never have heard.

In a 2018 position paper, Jefferson Parkway Advisory Committee member Randy Stafford examined decades of soil studies, health research and historical records to argue that disturbing soil along Indiana Street could create additional public-health risks. His paper brings together important evidence—and competing interpretations—at the center of the Jefferson Parkway debate.