Colorado's Superfund Sites Stretch From Silverton to East Colfax Avenue

On Monday, the Navajo Nation formally endorsed a Superfund cleanup of contaminated mines in southwestern Colorado – including an Environmental Protection Agency-caused spill at the Gold King Mine site that released millions of gallons of contaminated water into the Animas River last August, tainting land stretching from Silverton down to Arizona. 

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
Jefferson County

5800 Galapago Street
Adams County

California Gulch/Yak Tunnel*
County Road 2 and vicinity

Captain Jack Mill/Lefthand Canyon
1.5 miles south of Ward
Boulder County

Central City/Clear Creek
Central City and Idaho Springs
Mining District/Argo Tunnel

Chemical Sales Co.
4661 Monaco Street

Colorado Smelter*
Between Interstate 25 and South Santa Fe Drive

Cotter/Lincoln Park
0502 Fremont County Road 68
Cañon City

Fonda Apostolopoulos
Denver Radium Sites*
Operable Unit 8 (Shattuck)

Eagle Mine
U.S. 24 between Gilman and Minturn

Lowry Landfill
4200 South Gun Club Road
Arapahoe County

Marshall Landfill*
66th Street (south of Colorado 170)
Boulder County

Nelson Tunnel/Commodore Waste Rock*
Creede Historic Mining District
Mineral County

Rocky Flats
Colorado 93, north of Colorado 72
Jefferson County

Rocky Mountain Arsenal
North of former Stapleton Airport
Adams County

Ruby Mining District
Crested Butte

Summitville Mine
Rio Grande County

Uravan Mill Site
Colorado 141

Vasquez Boulevard/Interstate 70*
Vasquez Boulevard and I-70

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Ana Campbell has been Westword's managing editor since 2016. She has worked at magazines and newspapers around the country, picking up a few awards along the way for her writing and editing. She grew up in south Texas.
Contact: Ana Campbell