Region 8

Nelson Tunnel / Commodore Waste Rock

Nelson Tunnel in the 1890s
Nelson Tunnel in the 1890s, Courtesy of Creede Historical Society
Nelson Tunnel site location map Site Type: Final NPL
City: Creede
County: Mineral
Street Address: One mile north of town
ZIP Code: 81130
EPA ID: CON000802630
Site Alias: Nelson Tunnel

What's New?

Updated March 2014

  • Monitoring wells were installed in the fall of 2013 in the Commodore Waste Rock Pile, to investigate possible metal loading coming from the waste rock pile to the surface water. Another well was installed near the confluence of East and West Willow Creeks to distinguish possible subsurface metals loading there.
  • EPA plans to continue seasonal sampling events of surface water in the West Willow Creek, Willow Creek and the Rio Grand River near the confluence, to continue to gather baseline data to compare with post-remedy data in the future.
  • Hydro-geologic investigations are nearing completion. EPA is compiling the isotope hydrology analysis, also called ‘finger printing,’ to understand the age, source and movement of groundwater in the area.
  • The options for remedies at the Nelson Tunnel differ, depending on whether or not the Bulldog Mine is dewatered for future mining operations; therefore, the progress on the Feasibly Study has slowed while Rio Grande Silver, the company that intends on mining the Bulldog Mine, works through the mine permitting process. EPA is compiling information and talking with Rio Grande Silver to more clearly understand the interconnections of the hydrology and possible long-term solutions for managing the drainage from the Nelson Tunnel.

Site Description

The Nelson Tunnel/Commodore Waste Rock Pile Superfund Site lies about one mile north of the city of Creede in the Willow Creek watershed in Mineral County, Colorado. The abandoned hard rock mine site consists of an adit draining directly into West Willow Creek and a large, formerly unstable waste rock pile which is part of the Commodore Mine.

In 1889, a party of prospectors, including Nicholas C. Creede, located the Holy Moses vein in the East Willow Creek drainage. The vein was extremely rich in silver. Prospecting increased in this area and in West Willow Creek. Two claims were staked up West Willow Creek, the Last Chance and the Amethyst mines, which would become the richest, most profitable mines in the Creede Mining District. Creede was one of the last silver boom towns in Colorado. Mining lasted nearly 100 years with the last mine closing in 1985.

West Willow Creek joins East Willow Creek to form Willow Creek which empties into the Rio Grande River approximately four miles downstream of the site. Historically, mining of silver, lead, and zinc provided economic viability to the area in and around the Creede mining district. The mining activity resulted in contaminated water discharging into the Willow Creek drainage and mine waste piles accumulating in the watershed.

Map of the Superfund site boundary and Operable Units

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Site Risk

Media Affected Contaminants Source of Contamination
surface water, mining waste rock pile arsenic, cadmium, lead, zinc, manganese mining
Legacy left behind
The Commodore mines and waste rock piles that today attract tourists, but are a reminder of the mining legacy left behind—contaminated waterways

Characterization of the watershed identified the Nelson Tunnel adit drainage as the largest source of cadmium, lead and zinc in the Willow Creek watershed. Immediately upslope and surrounding Nelson Tunnel is the waste rock pile from the Commodore Mine, which is comprised of waste rock from hard rock mining that accumulated over the years. The waste rock contains elevated levels of arsenic, cadmium, lead, manganese and zinc. In 2005, a less-than-20-year flood event caused catastrophic failure of the waste rock. As a result, the Commodore Waste Rock Pile became highly unstable and partially collapsed into West Willow Creek. EPA conducted a removal action that stabilized the Commodore Waste Rock Pile (see Cleanup Progress below).

West Willow Creek runs through the site carrying contamination into Willow Creek and the Rio Grande River four miles below the site. A biological assessment of the Willow Creek watershed indicated concentrations for cadmium, lead and zinc that exceed recommended dietary intake benchmarks and aquatic water standards for fish and birds. The assessment identified cleanup of Nelson Tunnel as a key element to restoring the Willow Creek stream and streamside habitat.

Since mining has moved out of the area, tourism and recreation have become the town's economic backbone. Fishing is an important part of recreation for visitors and locals. Fisheries have been impacted to the point that no fish exist for approximately a two-mile stretch below the site. Below that stretch the fish are sparse and appear to be suffering from reproductive effects of metal contamination. Willow Creek is a tributary of the Rio Grande River, a State-designated Gold Medal fishery.

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Cleanup Progress

2012 and 2013: On-Going Studies

  • Sampling of the site surface water continues to capture seasonal variation and verify metals loadings.
  • Isotopic hydrologic investigations continued to assist in determining the sources of water to the mine workings. Additional samples for isotopic analysis were collected from the Bulldog Mine and a deep water well in the vicinity.
  • Conversations with Rio Grande Silver continue to assist in understanding how mining in the Bulldog Mine may influence the Nelson Tunnel remedy possibilities.

2011: Nelson Tunnel Hydrological Investigation and Remedial Investigation

Nelson Tunnel today
Nelson Tunnel today

The Remedial Investigation Report was completed and is available in Site Documents below. It is also available at the Creede Town Hall and EPA Superfund Records Center information repositories listed below.

After a structural geologist visited the Nelson Tunnel to learn more about the mine workings inside the tunnel, he recommended drilling a deep well up-gradient of the Nelson Tunnel and Commodore Mine workings to intersect the faults and fractures that may serve as a conduit for water entering the mine workings. EPA has not implemented this suggestion since dewatering at the Bulldog Mine may produce a reduction in flows at the Nelson Tunnel and may open up other remedy possibilities.

2010: Superfund Process Begins

As the Nelson Tunnel/Commodore Waste Rock Superfund site gets underway, the first step is to complete a Remedial Investigation/Feasibility Study (RI/FS).

  • The goals of the RI/FS are to determine the nature and extent of the contamination and to provide adequate information that allows EPA, after considering public comments, to select a remedy that addresses the potential risks to human health and the environment. During the RI, the water is characterized and information is gathered to assist in determining if there is a way to keep clean water from becoming contaminated. This would provide a smaller volume of water that would need treatment.
  • The FS process involves reviewing different technologies and evaluating the feasibility of these as cleanup remedy options for the Nelson Tunnel.

The best of the cleanup options will go into a summary report known as the proposed plan, the second step in the Superfund process. One of these alternatives will be EPA’s preferred cleanup remedy. This information will be presented at a public meeting where public comments are recorded. There will also be a 30-day comment period for the public to submit their comments. EPA reviews the comments and responds accordingly. This responsiveness summary becomes part of the Record of Decision (ROD), the official document stating what the remedy entails; this is the third step of the process. The remedial design and remedial action follow after the ROD.

2009: Commodore Waste Rock Pile

Constructing the new West Willow Creek channel
Constructing the new West Willow Creek channel

The Waste Rock pile needed to be reconfigured and a new channel made to slow the flow of West Willow Creek, especially during spring run-off. This was accomplished by:

  • Waste rock was temporarily moved below the confluence of East and West Willow Creek to allow for re-configuring of the waste pile.
  • A new channel was dug to a lower base and in some cases near the original base of West Willow Creek.
  • An armored channel was constructed using rip rap and grouting to keep water from seeping through.
  • Energy dissipating structures were installed to slow the flow of water.

2009: Development of the Remedial Investigation/Feasibility Study Began

  • EPA reviewed data the Willow Creek Recreation Committee, the Colorado Division of Reclamation, Mining, and Safety (DRMS), the Colorado Department of Public Health and Environment (CDPHE), and Colorado University, Boulder had collected and EPA determined what information was still needed.
  • Monitoring water in the Nelson Tunnel for seasonal changes and for isotopic analysis, or “finger printing” continued. This will help determine the sources of the water entering the tunnel.

2008: Commodore Waste Rock Pile

  • A temporary stream diversion around the construction area in West Willow Creek was completed.
  • The diversion had provisions for overflow if circumstances dictated.
  • Most of the debris, old pipes, flume, etc. were removed from West Willow Creek.
  • In preparation for construction of the new conveyance system, some grading of the lower portion of the waste rock pile was completed.

2008: Nelson Tunnel/Commodore Waste Rock Pile Superfund Site

  • September 2008 the site received its final listing designation on the National Priorities List.
  • March 2008 the site was proposed to be listed on the National Priorities List.

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Community Involvement

Community involvement plays an important role in the Superfund process. EPA uses a number of different tools and resources to promote effective, on-going, meaningful community involvement. The goals of the Superfund community involvement program are to:

  • Keep communities affected by sites informed throughout the cleanup process
  • Provide opportunities for communities to comment and offer their input about site cleanup plans
  • Facilitate the resolution of community issues tied to a site

A Community Involvement Plan for this site has been prepared and outlines any outreach activities that EPA plans to implement to keep the community informed and address community concerns.

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EPA places a high priority on land reuse as part of its Superfund response program mission. The Agency tries to select cleanup options that encourage and support future use of a site. We use two fundamental methods to facilitate reuse of Superfund sites:

  • Exploring future uses before the cleanup remedy is implemented, an approach that gives the Agency the best chance of designing cleanup remedies to support the likely future use of a site.
  • Working with landowners and communities to remove barriers not considered necessary for the protection of human health or the environment at those sites where remedies are already in place.

One option for reuse is the siting of clean and renewable energy projects on contaminated (or formerly contaminated) lands. As part of this effort, EPA is evaluating the potential for energy projects on these properties and working with landowners and communities to identify ways to remove barriers to such projects.

The reasonably anticipated future land use is typically determined during the RI/FS process. This information is considered during the development and selection of the remedy for the site.

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Land Use Controls and Other Institutional Controls

Land use controls are the most common type of institutional control (IC). ICs are administrative or legal controls that help reduce the likelihood for human exposure to contamination. ICs can also help protect the integrity of the remedy. Examples of ICs are:

  • Zoning ordinances
  • Environmental covenants
  • Deed notices
  • Well-drilling restrictions
  • Building permits
  • Informational advisories

Options for land use controls and other institutional controls are typically considered during the RI/FS process to help minimize the potential for human exposure to contamination and/or to protect the integrity of the remedy. Institutional controls that are selected as a part of the remedy will be included in the Record of Decision.

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Five-Year Reviews

EPA or the lead agency conducts five-year reviews following the start of a Superfund cleanup when contamination is left on the site. These reviews are repeated every five years. We use these reviews to determine:

  • How the remedy is working
  • If the remedy remains protective of human health and the environment

Five-year reviews are not yet needed at this site.

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Site Documents

Willow Creek Watershed Environmental Activities, May 2015

Remedial Investigation Report, November 2011

Baseline Ecological Risk Assessment, October 2011

Cleanup Update, June 2011

Community Involvement Plan, May 2009

HRS Package (the NPL proposal), March 2008

HRS Listing Fact Sheet, August 2007

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Joy Jenkins
Remedial Project Manager
U.S. Environmental Protection Agency, Region 8
1595 Wynkoop Street (8EPR-SR)
Denver, Colorado 80202-1129
800-227-8917 ext. 312-6873 (toll free Region 8 only)

Cynthia Peterson
Community Involvement Coordinator
U.S. Environmental Protection Agency, Region 8
1595 Wynkoop Street (8OC)
Denver, Colorado 80202-1129
800-227-8917 ext. 312-6879 (toll free Region 8 only)


Wendy Naugle
State Project Manager
Colorado Department of Public Health and Environment
Hazardous Materials and Waste Management Division
4300 Cherry Creek Drive South B2
Denver, CO 80246
888-569-1831 ext. 3394 (toll-free)

Jeannine Natterman
State Community Involvement Coordinator
Colorado Department of Public Health and Environment
Hazardous Materials and Waste Management Division
4300 Cherry Creek Drive South B2
Denver, CO 80246
888-569-1831 ext. 3303 (toll-free)

Site Information Repositories:

Creede Town Hall
Meeting Room
2223 N. Main Street
Creede, CO 81130
M–F, 8 a.m.–4:30 p.m.
Appointment is recommended

Colorado Department of Public Health and Environment
Hazardous Materials and Waste Management Division
4300 Cherry Creek Drive South B2
Denver, CO 80246-1530
888-569-1831 ext. 3331 (toll-free)
By appointment only

EPA Superfund Records Center
1595 Wynkoop Street
Denver, CO 80202-1129
To request copies of administrative record documents call:
800-227-8917 ext. 312-7273 (toll free Region 8 only)

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Photo/Video Gallery

Click on a thumbnail below to view the full size image.

Removal of rock and debris from the Commodore Waste Rock Pile and West Willow Creek
Grouting the rip rap used to line the West Willow Creek channel
The armored channel after placing a liner and rip rap in the channel and grouting it to prevent any seepage of West Willow Creek
The West Willow Creek channel as it drops over the Commodore Waste Rock Pile
The new West Willow Creek channel as it flows down to join East Willow Creek

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ATSDR Public Health Assessments & Health Consultations – Colorado

Willow Creek Reclamation Committee Exit

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