DENVER, OCT 23, 2017 -- The U.S. Environmental Protection Agency (EPA) and the Colorado Department of Public Health and Environment (CDPHE) have released two final Records of Decision for environmental remediation at the Eagle Mine Superfund Site in Eagle County, Colorado, following the consideration of input received through a public comment process. Both documents, specifying measures to protect water quality and facilitate site reuse, focus on further reducing exposure to heavy metal contamination created by nearly one-hundred years of mining activity at the site.
"These actions reflect both EPA's and CDPHE's commitment to efficiently evaluate conditions and protect human health and the environment at the Eagle Mine Superfund Site," said EPA Assistant Regional Administrator Betsy Smidinger. "Together, we are strengthening the water quality improvements we have achieved in the Eagle River and providing opportunities to bring lands back into safe, productive reuse. EPA remains committed to improving environmental conditions and human health for Americans that live and work near Superfund sites."
The amended Record of Decision finalized for Operable Unit 1 (OU1) at the Eagle Mine Superfund Site adopts site-specific arsenic remedial goals and modifies surface water cleanup levels for cadmium, copper and zinc to meet more recent standards established for the site by the Colorado Water Quality Control Commission in 2008. Water quality monitoring in the Eagle River indicates that these standards for cadmium, copper and zinc are not attained in March and April of most years. The OU1 Record of Decision requires institutional controls to protect existing remedial features and expands the current groundwater collection system in Belden and at the mouth of Rock Creek to further reduce metals loading to the Eagle River.
EPA and CDPHE have also finalized a separate Record of Decision for Operable Unit 3 (OU3) focused on soil remediation necessary to protect human health should future residential development occur. EPA created OU3 after a developer purchased a large portion of the Eagle Mine Superfund Site in 2004 with plans to develop the property into a private, residential community. The Record of Decision for OU3 includes a combination of the following elements for areas proposed for development: excavating soil; placing a soil exposure barrier; grading the site; placing institutional controls and conducting monitoring; and/or demolishing structures.
The Eagle Mine Superfund Site is located in Eagle County, Colorado. The site is defined as the area impacted by past mining activity along and including the Eagle River between the towns of Red Cliff and Minturn. Mining activities at the Eagle Mine began in 1879 and continued until 1984. EPA listed the site on the National Priorities List (NPL), commonly known as the list of Superfund Sites, in 1986 because of the mine metals discharge, uncontrolled mine waste piles and the close proximity of the population to the mine and associated features. To better manage the site, EPA divided it into operable units.
EPA and CDPHE issued a final Record of Decision for the Eagle Mine Superfund Site in 1993. Over the years, all required environmental cleanup work has occurred at the site under a number of state and federal directives. EPA declared all cleanup construction activities complete at the site in 2001. Remediation conducted to-date has resulted in significant improvement in water quality and reduction in risk to human health and the environment. Continued operation of the existing remedy, including drawdown from the mine pool and treatment at the water treatment plant, is required to maintain this condition. Contaminant concentrations in surface water and groundwater have decreased significantly, and the aquatic ecosystem continues to show signs of recovery.
