Colorado School of Mines Site Environmental Remediation
Numerous industrial mineral research projects involving materials that contained natural radionuclides and metals were undertaken on the Site from 1912 until about 1987. Sixteen buildings once occupied the six-acre Site that is located on the south bank of Clear Creek near the campus of the Colorado School of Mines. The Colorado Department of Public Health and Environment (CDPHE) has issued a Radioactive Materials License to CSMRI for the Site (License). The License authorizes storage of “naturally occurring, source, and byproduct radionuclides.”In 1992 a City of Golden water main broke and released water into an inactive settling pond on the Site. This prompted the U.S. Environmental Protection Agency (EPA) to undertake an emergency removal action pursuant to the “Comprehensive Environmental Response, Compensation, and Liability Act” (CERCLA).
This activity involved the excavation of 22,000 cubic yards of soil from the vicinity of the pond. The material was later disposed as a “special solid waste” at a local solid waste landfill. The EPA removal action ended in 1997. All of the above-ground structures on the Site were removed, including concrete slabs, asphalt-paved areas, and subsurface footers for some of the buildings. The Site is encircled by an eight-foot chain link fence. Numerous environmental assessments of the CSMRI Site have been accomplished. Some assessments show that material with levels of radionuclides and/or metals above background remain locations at the CSMRI Site. Where these materials are present, they are part of naturally occurring decay chains and minerals. In 2004 New Horizons was selected to identify, excavate, and dispose of contaminated soils at the Site. Field work began in April of 2004.
This field work constituted Phase II of the environmental assessment and response. By May of 2004 it was apparent that excavated soil volumes exceeded previously estimated volumes. Work was halted and the Site stabilized. Approximately 1870 cubic yards of soil had been excavated, bagged, and stored on the Site by New Horizons during the 2004 remediation work. This bagged soil had been initially slated for disposal at the U.S. Ecology RCRA facility in Idaho. The contract with New Horizons was terminated in the Fall of 2004.Additional work was required to accomplish the goals of the remediation project. The goals were to properly manage all environmental and public health risks at the Site, develop a final remedy for the Site, terminate the License, and return the Site to beneficial uses. NMNTI analyzed the surface soil samples for the radionuclides of interest using a calibrated Gamma Spectrometer to define and segregate Ra-226 contaminated soil and rock thus reducing waste volumes by better definition of decisions on material found to be above background.