Site DescriptionThe Illinois Gulch Site is an area of historic mining activity along Boreas Pass Road in Breckenridge, Colorado. Waters from two historic adits and several natural seeps drain through a wetland that contains several large mine waste piles. This contaminated water, characterized by elevated levels of heavy metals and low-pH, works its way down the watershed to Illinois Gulch, the Blue River and ultimately Dillon Reservoir.
The Site is located in a residential area with several properties that are immediately adjacent to the historic mine features. EPA has not determined whether or not these properties have been impacted by soil from these mine features.
Initial ResponseIn Fall 2020, EPA issued the owner of the historic mine features, TransAmerica, a Unilateral Administrative Order, to:
a) reduce the flow of water from the adits by preventing water from entering a nearby mine shaft;
b) control the flow of water through the wetland and move it away from the waste piles;
c) install a passive remediation system to improve water quality;
d) consolidate and cap the waste piles; and
e) sample nearby residential properties and remediate them as necessary.