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Basin Mining Area
Site Type: Final NPL
Updated March 2014
EPA recently held a public meeting to provide information on the RI/FS reports, the proposed plans and our preferred cleanup alternatives for the Crystal and Bullion mine sites, Operable Units 5 and 6 of the Basin Mining Area Superfund site. Interested individuals can provide comments on the proposed plans by sending written comments to Kristine Edwards during the public comment period, which runs through April 21, 2014.
EPA has completed focused Remedial Investigation (RI) and Feasibility Study (FS) reports for the Crystal and Bullion mine sites located in the Basin Watershed. Proposed plans, which summarize the studies and include the preferred alternatives for cleanup for each of these two mine sites, are available for public comment. EPA decided to focus on the Crystal and Bullion mine sites before addressing the remainder of the watershed because these two sites are the worst offenders from a water quality degradation perspective. Each site has a discharging adit which releases acidic, contaminated water. Acidic discharges from the Bullion mine contaminate water in Basin Creek. Acidic discharges from the Crystal mine contaminate Cataract Creek. Both Basin Creek and Cataract Creek are tributaries to the Boulder River. The proposed plans will be followed by interim records of decision for both the Crystal and Bullion mine sites after consideration of public comments.
EPA listed the Basin Mining Area to the Superfund National Priorities List (NPL) on October 22, 1999, due to mining-waste problems in the watershed and mining waste in the Town of Basin. The mining area includes the watersheds of Basin and Cataract Creeks and portions of the Boulder River below the confluence with these heavily impacted streams. Listing makes the site eligible for federal cleanup funds while EPA seeks to recover costs from the parties responsible for the contamination, or to complete the work if no parties are found. The NPL designation also allows EPA to cooperate with other agencies (such as the US Forest Service) in the cleanup.
Mine wastes impact Basin and Cataract Creeks and the soils within the Town of Basin. Contaminants include arsenic, cadmium, copper, lead and other metals.
|Media Affected||Contaminants||Source of Contamination|
|groundwater, surface water, sediment, soils||arsenic, cadmium, copper, lead, zinc and other metals||mine wastes|
The Basin Mining Area Superfund site consists of six operable units:
- OU1 - Town of Basin
- OU2 - Basin Watershed, within which lies:
- Luttrell Repository - OU3
- Buckeye/Enterprise mines - OU4
- Crystal mine - OU5
- Bullion mine - OU6
EPA prioritized its focus on the Town of Basin (OU1) due to human health concerns. A Record of Decision (ROD) and a Remedial Action have been completed in the Town of Basin. The Basin Watershed (OU2) has undergone a Remedial Investigation and Feasibility Study, but has not progressed to a ROD. EPA decided to first conduct interim remedies at the Crystal and Bullion mine sites before developing a ROD for the Basin Watershed due to the acidic mine drainage at these sites which significantly degrades water quality.
OU1 – Town of Basin
In the summer of 1998, EPA conducted a removal action near residential properties in the Town of Basin, which removed some of the mining waste sources. EPA then completed a remedial investigation in October 2000 and a feasibility study in December 2000.
A human health risk assessment was completed in October of 2000 as well as a Proposed Plan for cleanup in January 2001. The Record of Decision was finished in March of 2001, with the selected remedy costing approximately $3.9 million. The residential component of the remedy began in September 2002 and was completed in November 2003. Source area cleanup began in May 2004 was completed in the fall of 2004. Two five-year reviews of the cleanup have been conducted; the first in 2007/2008 and the second in 2012/2013. Both found that the remedy has remained protective.
OUs 2 through 6 - The Basin Watershed and Other Operable Units
Working in partnership with the U.S. Forest Service, EPA conducted some limited removal actions at the Buckeye/Enterprise (OU4), Crystal (OU5) and Bullion (OU6) mines, all located within the Basin Watershed (OU2). The removals were completed in 2002. These projects were managed as EPA Removal Program projects, and funding was provided by each agency according to the ownership (federal or private). Wastes were disposed of in the joint EPA/Forest Service Luttrell Repository (OU3).
Remedial investigation of the mine waste sites in the Basin Watershed began in 1999 and was completed in 2005. Over 300 mine waste areas were identified within the 77-square mile Basin Watershed. These areas were grouped into the following five risk categories, based on an environmental data-driven scoring system: very low, low, medium, medium-high, and high priority. Only high, medium-high, and medium priority sites are being considered for active remedial action.
EPA is currently working on interim Records of Decision for additional cleanup work at the Crystal and Bullion mines, both of which scored in the high category. A public meeting to discuss the proposed plans for the Crystal and Bullion mines and to receive public comments will be held on Wednesday, March 19, 2014. Written comments on the proposed plans will also be accepted during the public comment period, which runs from March 7, 2014 through April 21, 2014. After work on these mines is complete, a Record of Decision for the Basin Watershed will be developed.
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.
Recent community involvement activities have occurred during the 2008 and 2013 five-year reviews for the Town of Basin cleanup. Residents of Basin were interviewed to understand their concerns about EPA’s remedy for the town and future plans for the watershed.
Under Superfund, affected communities are eligible to receive Technical Assistance Grants from EPA to provide a technical advisor for independent review of the proposed work. Please contact Kristine Edwards for more information.
EPA recently held a public meeting to discuss the proposed plans for cleanup of the Crystal and Bullion mines. Interested individuals can provide comments on the proposed plans by sending written comments to Kristine Edwards during the public comment period, which runs through April 21, 2014.
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. EPA uses 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 RemediaI Investigation/Feasibility Study (RI/FS) Superfund process. This information is considered during the development and selection of the remedies for the site. Additionally, many properties in the Town of Basin are already in continued use as residential and commercial properties.
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.
Institutional controls will be evaluated for sites in the Basin Watershed as cleanup actions progress there. Informational fact sheets will be updated and distributed to assist residents and recreationists in understanding the risks posed by contaminated mine waste areas in the Watershed. EPA will work with Jefferson County to develop a contaminated-soil removal and disposal program in the event mine wastes are encountered during future excavations. EPA also anticipates that Institutional Controls will be needed to protect remedies at sites in the Basin Watershed, including the Crystal and Bullion mine sites, and will work with the State and Jefferson County to develop those controls.
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.
EPA completed the second five-year review for the site on June 27, 2013. This review focused on Operable Unit 1, the Town of Basin cleanup. OU1 is the first operable unit in the Basin Mining Area Superfund site to have progressed to remedial action, although some other operable units have undergone limited removal actions. The five-year review found that the remedy at OU1 is working and remains currently protective of human health and the environment. The five-year review also concluded that for future protectiveness, an institutional control (IC) should be developed with Jefferson County to assure that mining-contaminated soils potentially found during future excavations in Basin receive proper handling and disposal.
Second Five-Year Review Report, June 27, 2013
Basin Watershed (OU2) Draft Remedial Investigation, December 2002 and Draft Final Feasibility Study Report, July 2005
Record of Decision for the Town of Basin (OU1) (PDF), March 30, 2001 (108 pp, 2.5 MB, About PDF)
Remedial Project Manager
U.S. Environmental Protection Agency, Region 8
10 West 15th Street, Suite 3200
Helena, MT 59626
State Project Manager
P.O. Box 200902
Helena, MT 59620
Site Information Repository:
EPA Superfund Records Center
10 West 15th Street, Suite 3200
Helena, MT 59626
866-457-2690 (toll free)
Hours: M-F, 8:00 a.m.-4:30 p.m.
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