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Superfund Program
California Gulch
NEW: EPA activities at the Leadville Mine Drainage Tunnel and Gaw Shaft
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Site Type: Active NPL City: Leadville Count: Lake Street Address: S. of CY-YAK Tunnel Downstream Zip Code: 80461 EPA ID#: COD980717938 Site ID#: 0801478 Site Aliases: Mestas Well Congressional District(s): 03 |
Site Status & Updates
NEW: Activities at the LMDT Site
Operable Unit 1: | The Yak Tunnel |
Lead: | Resurrection-Asarco Joint Venture |
Status: | Ongoing water treatment |
Starting in 1990, the Asarco-Resurrection Joint Venture agreed to design, build and operate a water treatment system to reduce the contaminants flowing frmo the Yak Tunnel. Water quality in the Arkansas River has improved since the treatment plant was built.
Operable Unit 2: | Malta Gulch |
Lead: | EPA |
Status: | Deleted |
Operable Unit 3: | Denver & Rio Grande Railroad Slag Piles, Railroad Easement, Railroad Yard, and Mineral Belt Trail |
Lead: | Union Pacific |
Status: | Institutional controls under development |
This unit encompasses several different slag piles and historic rail yards with high lead levels, including the Harrison Avenue slagpile and a portion of the Mineral Belt Trail. Slag is a by-product of smelting operations that has a high concentration of heavy metals. Union Pacific removed and consolidated the Harrison Steet slag pile into the Arkansas Valley slag pile. Based on current land use, EPA determined that slag does not pose elevated health risks.
Operable Unit 4: | Upper California Gulch |
Lead: | Resurrection Mining Co. |
Status: | Ready for deletion |
This watershed is located above the Yak Tunnel and Resurrection has constructed water diversion channels and settling ponds to prevent heavy metals from flowing into surface water.
Operable Unit 5: | Asarco Smelter/Colorado Zinc-Lead Mill Site |
Lead: | Asarco, Inc. |
Status: | Remedial Action Underway |
This unit addresses contaminants associated with five historic smelters and one mill. Smelter waste and waste rock, and tailings from the milling process, are being consolidated and capped with a soil cover on-site.
Operable Unit 6: | Strayhorse Gulch |
Lead: | EPA |
Status: | Remedial Action and Remedial Design |
A Record of Decision (ROD) was signed in 2003 and water management projects were completed during the summer of 2004. This involved removing the Ponsardine waste rock pile and rebuilding the Robert Emmet Crib Wall. EPA is in the design process for additional work activities that will address long-term water quality in Strayhorse Gulch, including a bulkhead in the Leadville Mine Drainage Tunnel. EPA is developing an agreement with the U.S. Bureau of Reclamation and the State of Colorado for the long-term treatment and management of the mine pool waters. Funding for the Leadville Mine Drainage Tunnel work has not yet been obtained.
Operable Unit 7: | Apache Tailings |
Lead: | Asarco, Inc. |
Status: | Ready for deletion |
Asarco completed consolidation efforts and placed a soil cap on this tailing pile in 2002. The site is ready for deletion.
Operable Unit 8: | Lower California Gulch |
Lead: | Resurrection Mining Co. |
Status: | Ready for deletion |
The unit is located between the Yak Water Treatment Plant and the point where the gulch enters the Arkansas River. Resurrection completed work here in 2002 that involved removing tailings and non-residential soils and channel stabilization in the 500-year floodplain. The site can be deleted once institutional controls are in place.
Operable Unit 9: | Residential Area |
Lead: | Asarco, Inc. |
Status: | Ongoing |
This unit addresses lead contamination in the residential areas of Leadville and Lake County. Asarco launched "Kids First" in 2000, a program to reduce young children's exposure to lead and to provide information about lead to the community. Both residential sub-units have met their performance goals, and EPA is currently working with the County and the Colorado Department of Public Health & the Environment to develop an Operations & Maintenance program. Additional residential actions included removing and/or placing soil covers on piles of waste rock, tailing and slag in 1995 and 1996.
Operable Unit 10: | Oregon Gulch |
Lead: | Resurrection Mining Company |
Status: | Deleted |
Operable Unit 11: | Arkansas River Floodplain |
Lead: | EPA, the State of Colorado and the mining companies are working together in a collaborative effort |
Status: | Remedial Design |
EPA completed a Record of Decision in 2005 and is coordinating with mining companies and state and federal natural resource trustees to agree on a settlement pertaining to Superfund and natural resource damages. EPA also is continuing a revegetation project in some of the areas affected by mine waste deposits.
Operable Unit 12: | Site-Wide Surface and Groundwater Quality |
Lead: | EPA, the State of Colorado and the mining companies are working together in a collaborative effort |
Status: | Ongoing |
EPA and the State of Colorado are sampling and evaluating water quality and aquatic life in the Arkansas River to determine if conditions are returning to healthy levels. Fish and aquatic insect populations have substantially increased since remedial actions have been completed. Further evaluations are needed to determine when acceptable cleanup levels have been achieved. Groundwater investigations are continuing.
Site Description
The National Priorities List site includes about 18 square miles in Lake County, Colorado, and includes Leadville, the highest incorporated town in the United States. Mining, mineral processing and smelting activities in the area have produced gold, silver lead and zinc for more than 130 years. Mining in the Leadville area began in 1859 when prospectors working in the channels of the Arkansas River tributaries discovered gold at the mouth of California Gulch. Wastes generated during the mining and ore processing activities contain naturally occurring chemicals at levels that pose a threat to human health and the environment. These wastes remain on the land surface and migrate through the environment by washing into streams and leaching contaminants into surface water and groundwater.
The site was added to the National Priorities List in 1983 and in 1994 was
divided into 12 geographically-based areas, also called operable units or OUs.
Investigation of the site began in the mid-1980s.
Site Risk
Media Affected | Contaminants | Source of Contamination |
Soil , sediment, surface water, ground water, liquid waste, solid waste,
sludge |
Lead, arsenic and other metals; acid mine drainage | Mining, milling and smelting operations |
Cleanup Progress
The Yak Tunnel, one of two tunnels that drain the historic mining district, was a primary focus of studies and cleanup activities between 1989 and 1994. Prior to construction of the Yak Water Treatment Plant, the tunnel discharged about 210 tons of metals each year into California Gulch, which drains into the Arkansas River.
Since 1995, EPA and the potentially responsible parties have conducted removal and remedial activities to consolidate, contain and control more than 350,000 yards of contaminated soils, sediments and mine-processing wastes. Cleanups by the potentially responsible parties are focusing on:
- Drainage controls to prevent acid mine runoff;
- Consolidation and capping of mine piles;
- Cleanup of residential properties; and
- Reuse of slag.
Community Involvement
Throughout the Remedial Investigation and Feasibility Study process, the EPA has maintained contact with members of the community and has implemented various community relations activities. These activities have ranged from one-on-one meetings and open houses to newspaper articles, fact sheet distributions, and meetings with local officials. EPA holds public meetings and public comment periods at every decision point along the Superfund process. For more information about this process, contact Jennifer Lane, EPA's community involvement coordinator, at 1-800-227-8917, ext. 6813.
An Information Repository containing the Administrative Record and other information
about the site is available in Leadville at the Lake County Public Library,
1115 Harrison Avenue, and at the Learning Resource Center of the Colorado Mountain
College..
Site Documents
Activities at the LMDT Site: Draft Relief Well Restoration Plan for Cal Gulch (PDF, 3 pp, 41K)
Five-Year Review Annual Update, December 2007 (PDF, 5 pp, 49K)
2007 Five-Year Review Report, September 2007 (PDF, 131 pp, 1.7 MB)
Lake County Community Health Program 2005 Annual Report:
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Text of the 2005 Annual Report (PDF, 44 pages, 516K)
Appendix A (PDF, 3 pages, 1.8 MB)
Appendix B (PDF, 2 pages, 36K)
Appendix C (PDF, 11 pages, 2.9 MB)
Appendix D (PDF, 7 pages, 77K)
Appendix E (PDF, 20 pages, 265K)
Appendix F (PDF, 6 pages, 129K)
Figure 1-1 (PDF, 1 page, 2.7 MB)
Figure 1-2 (PDF, 1 page, 2.5 MB)
Figures 6-2 to 6-5(PDF, 5 pages, 2 MB)
Figures 6-6 to6-9a (PDF, 5 pages, 1.6 MB)
Figures 6-10 to 6-15 (PDF, 10 pages, 2.5 MB)
March 17, 2004, OU 4, Fluvial Tailing Site 4 / Oro City Explanation of Significant Differences (PDF, 400K)
September 2005 OU 11 Record of Decision (PDF, 117 pages, 4.1 MB)
More Records of Decision (RODs) | Location Map
Notices of Partial Deletion from the NPL
OU 2 07-23-2001
OU 9 04-22-2002
OU 10 04-16-2001
Contacts
EPA
Rebecca Thomas Mike Holmes Jennifer Lane |
Colorado Warren Smith |
View Documents at: Lake County Library Colorado Mountain College Library |
Neighborhood Group Technical Assistance Grant Group Concerned Citizens for Conservation Leadville, CO 80461 Jim Davidson, President |