Superfund sites dot Colorado; arguably the most well known is the long-dormant Rocky Mountain Arsenal, the chemical weapons and pesticide manufacturing plant once dubbed the most contaminated square mile on earth and now home to a wildlife refuge.
Many other past and present Superfund sites are tougher to spot, including the Denver radium sites.
Radium, once thought to be a miracle cure for cancer, was big business in Denver before the industry went belly up in the 1920s. Years later, all that remained of the industry were the 65 properties around Denver contaminated with radioactive material, which an EPA official discovered in the late '70s. Soil at the sites was contaminated with radium, thorium and uranium, the radioactive decay of which produces radon gas, according to a Colorado Department of Public Health and Environment report.
In 1980, then-President Jimmy Carter signed into law the Comprehensive Environmental Response, Compensation and Liability Act, which set up an EPA-managed fund dedicated to paying for the cleanup of hazardous sites around the country. That included the Denver radium sites, which in 2010 were finally released from the EPA's National Priorities List, "the list of national priorities among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States and its territories," according to the EPA's website.
Colorado Department of Public Health and Environment officials still test groundwater at the former Shattuck Chemical Co. site in south Denver, which falls under Denver radium's Superfund, and they will continue to test water every five years until it meets department standards.
The radium sites have all been cleaned up, the contaminated asphalt and soil scraped off and hauled away. But there are other active Superfund sites in Colorado, as noted below. The Colorado Department of Public Health and Environment is the lead cleanup agency at all of the sites except those marked with an asterisk, which are led by the EPA. The EPA has a full list of proposed, final and deleted sites in Colorado.
Air Force Plant PJKS
12500 South State Highway 75
5800 Galapago Street
California Gulch/Yak Tunnel*
County Road 2 and vicinity
Captain Jack Mill/Lefthand Canyon
1.5 miles south of Ward
Central City/Clear Creek
Central City and Idaho Springs
Mining District/Argo Tunnel
Chemical Sales Co.
4661 Monaco Street
Between Interstate 25 and South Santa Fe Drive
0502 Fremont County Road 68
Denver Radium Sites*
Operable Unit 8 (Shattuck)
U.S. 24 between Gilman and Minturn
4200 South Gun Club Road
66th Street (south of Colorado 170)
Nelson Tunnel/Commodore Waste Rock*
Creede Historic Mining District
Colorado 93, north of Colorado 72
Rocky Mountain Arsenal
North of former Stapleton Airport
Ruby Mining District
Rio Grande County
Uravan Mill Site
Vasquez Boulevard/Interstate 70*
Vasquez Boulevard and I-70