Did a glow-in-the-dark dial maker once help turn part of Denver radioactive?

A company producing luminescent radium dials in Denver was part of numerous businesses, including radium processing plants, that contributed to the area’s radioactive contamination in the early 1900s.  

In 1918, the Cold Light Manufacturing Company produced luminous dials for military use. One of their manufacturing sites, at 2001 E. Colfax Ave., became part of the Denver Radium Superfund site. A Superfund designation authorizes the Environmental Protection Agency to clean up these sites, often contaminated by hazardous waste.

Denver was a hub for radium, vanadium and uranium processing in the 1910s and 1920s. Decades later, the discovery of the radioactive contamination led to the creation of the Superfund site, consisting of 65 properties along the South Platte River Valley. 

The removal of at least 500,000 tons of contaminated materials in the 1990s and 2000s rendered the area safe for redevelopment. 

Approximately 100 businesses are now on the site. Groundwater monitoring continues.