The Nelson Tunnel/Commodore Waste Rock site sits near Creede, Colorado, where acid mine drainage flows from the Nelson Tunnel into West Willow Creek and downstream into the Rio Grande River. The Rio Grande is a state-designated Gold Medal fishery. The U.S. Environmental Protection Agency (EPA) added the site to the National Priorities List (NPL) in September 2008 because of ongoing water quality impacts. The NPL is the federal list of the most serious hazardous waste sites in the country.
The main contaminants are cadmium and zinc, both present in surface water at levels above Colorado's water quality standards. These metals harm fish, insects, and plants. The rocky creek channel and concrete sections running through town limit aquatic habitat near the tunnel, but conditions improve further downstream near the Rio Grande flood plain. Health risks come from contact with waste rock, soil, or surface water, and from breathing contaminated dust. Physical access to the site is currently restricted, which keeps most people away from the contamination in the short term. EPA assessments show human exposure is currently under control, though groundwater migration cannot be fully evaluated due to insufficient data.
Cleanup work has unfolded in several stages. Community members formed the Willow Creek Reclamation Committee in 1999. Between 2008 and 2010, the EPA stabilized the Commodore Waste Rock Pile by grading slopes, removing mine waste from the creek, and building about 2,000 feet of reinforced creek channel. From 2018 to 2022, a time-critical removal action rehabilitated the mine's Commodore 5 level and connecting tunnels to relieve pressure on blockages inside the Nelson Tunnel and prevent an uncontrolled release of contaminated water. The site is divided into three operable units. Operable Unit 2, the Nelson Tunnel/Draining Adit, has a Record of Decision (ROD) dated April 5, 2021, selecting drainage and erosion control as cleanup methods. Remedial design for that unit finished on September 30, 2025, and remedial action started that same day, with an estimated completion in mid-2028. A removal action for Operable Unit 1, the Commodore Waste Rock, is scheduled to begin between March and May 2028.
The EPA is also working toward a final remedy that may include source control, semi-passive water treatment, or active water treatment. Drilling, water sampling, and treatability studies are ongoing. Surface water and groundwater sampling continues every other year across the Willow Creek watershed.
Community members can get involved in several ways. The EPA and the Colorado Department of Public Health and Environment (CDPHE) both have staff assigned to the site and are reachable by email and phone. Site records are available for review at the Creede Town Hall Meeting Room, at CDPHE offices, and at the EPA Superfund Records Center in Denver, with appointments recommended or required. A reuse situation assessment was completed in 2019, and community outreach efforts have continued through grants supporting local watershed partnerships.
