This is a National Priorities List (NPL), or "Superfund," hazardous waste site. While we’re the lead agency for remediation of the site, the EPA Superfund Program provides technical support and input on all remediation-related activities to ensure the objectives of the Superfund program are met.
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Upcoming public meeting
Date/Time: TBA
Location: TBA
Zoom link: TBA
Zoom phone number: TBA
Past meeting materials
Factsheets
- Understanding bioavailability.
- Operable Unit 5.
- Unidad Operable #5.
- OU5 Property owners and developers factsheet.
- Dirt Alert.
- Alerta de Tierra Contaminada!
Site documents
- Sixth five year review.
- Addendum to Central City / Clear Creek Five-Year Review Report.
- CC/CC OU5 Property Inquiry.
- Community involvement plan update, July 2023.
Site summary
In 1859 gold was discovered near Idaho Springs in Clear Creek County. Shortly after, a major lode deposit was discovered in the adjacent Gilpin County. For the next two decades the Black Hawk/Central City area was a leader in Colorado mining, with many mills built for the processing of gold and silver.
Mining continued as an important industry in Clear Creek and Gilpin counties until about 1950. In 1983, the area was placed on the National Priorities List as a Superfund site. The Central City/Clear Creek Superfund Site (Site) is located in a 400-square mile watershed extending from the Continental Divide to Golden, Colorado and is located within Gilpin and Clear Creek Counties.
Environmental concerns
The threats to public health and the environment at the site come from risks of exposure to heavy metals from historic mining and the effects of acid mine drainage into Clear Creek and its tributaries. The metals of primary concern for aquatic life found within the site include aluminum, arsenic, cadmium, chromium, copper, manganese, silver and zinc. The metals of primary concern for human health found within the site are arsenic and lead.
Current site remediation
The CDPHE, the U.S. Environmental Protection Agency (EPA), and the local community and agencies have implemented remedial activities to remove metals contamination from the Clear Creek watershed. Priority waste piles have been remediated and two active water treatment plants are operating to prevent heavy metals from entering the surface water or Clear Creek.
Future cleanup activities (OU5)
The division and EPA are overseeing an investigation of mine waste piles in the Clear Creek Superfund Site. The investigation is the first step in the cleanup process of the additional mine waste piles located in residential areas of the site. These piles contain concentrated materials left over from mining operations.
We expect our remedial investigation to be complete by 2025. We encourage residents to follow the best practices found in the factsheets above to protect their health.
CDPHE and EPA hold regular meetings to discuss the status of the site and of OU5. The recordings to those meetings are linked above. The recordings and presentation slide-decks also provide detailed explanations of the work that has been previously conducted at the site, the nature of the Superfund/CERCLA regulatory process, and best practices residents can use to identify potential contaminant sources.