Characterization, Cleanup, and Revitalization of Mining Sites

Revitalization and Reuse

Considering the potential future uses of abandoned mine lands is an important part of EPA's commitment to finding innovative and effective approaches to reducing the potential threats that these contaminated lands pose to human health and the environment. EPA recognizes that land reuse often brings economic, environmental, and social benefits to communities, and also may serve as a catalyst for expediting environmental risk reduction. EPA's Abandoned Mine Lands Reuse and Revitalization web page includes links to reports, fact sheets and technical resources related to revitalization of mine lands.

• The Mine-Scarred Lands Initiative Tool Kit shares what was learned through the Federal Brownfields Partnership's Mine-Scarred Lands Initiative by working with six demonstration projects on hard rock and coal mining sites throughout the country. In addition to the experiences of the six projects, the toolkit includes links to other mine cleanup and reuse resources.
• Mine Site Cleanup for Brownfields Redevelopment: A Three-part Primer summarizes the basic issues surrounding mine site cleanup for brownfields redevelopment, including innovative characterization and remediation approaches. The Primer includes detailed technical information about the characterization, remediation, and redevelopment of hard rock and coal mine sites. It is intended for those with an interest in, and knowledge of the technical aspects of redeveloping coal mine sites.
• Abandoned Mine Lands: A Decade of Progress Reclaiming Hardrock Mines sheds light on abandoned mining sites and their impacts on public lands as well as highlight the accomplishments of the BLM, the Forest Service, and project partners in addressing AML problems. Examples provided offer insight into the environmental, health, safety, and economic effects often associated with these sites and illustrate the lasting and acid mine drainage leaching from the positive impacts of reclamation activities on formerly mined lands.
• The journal article Ecosystem Services Consideration in the Remediation Process for Contaminated Sites, primarily authored by EPA staff, provides environmental stakeholders involved in contaminated site cleanups with a single resource to address ES and help guide decision-making during the cleanup process.
• EPA developed fact sheets that describe reuse and revitalization of former mining sites:
• Wetland Banking at Former Mine Lands: An Ecological Solution with Economic Benefits
  Describes the opportunities associated with reusing former mine lands to create wetland banks
• Land Conservation and Former Mine Lands: Preserving Natural Land Resources, Planning for the Future
  Explains to communities, mine land owners, potentially responsible parties, companies, and other interested groups how land conservation tools can be used as part of an integrated strategy to remediate and restore former mine lands. Describes available land conservation tools and their potential benefits and the opportunities and limitations associated with using different land conservation tools.
• Water Quality Credits at Former Mine Lands: Improving America's Water Resources, Reclaiming Lost Landscapes
  Explains to communities, mine land owners, potentially responsible parties, companies, and other interested groups how water quality trading credits can be used as part of an integrated strategy to clean up and restore former mine lands. Also describes the opportunities and limitations associated with using water quality trading credits and provides resource and contact information.
• Reuse Alternatives for the Cochiti Gravel Mine: Cochiti Pueblo, New Mexico (EPA 560-F-17-199)
  Land revitalization success story describes technical assistance provided by the EPA Land Revitalization Team to the Cochito Pueblo to help develop reuse alternatives for a former gravel mine. The Team identified reuse alternatives for the mine based on feedback from tribal members, recognizing tribal concerns for safety, and taking into account unknown geotechnical conditions, restoration potential, and site location.
• Brownfields Success Story: A Former Coal Mine Springs to Life - Weirton, West Virginia (EPA 560-F-17-222)
  Brownfields success story describes the use of EPA Brownfield Assessment Grants to assess contamination at a business park located on a former coal mine. The assessments lead to the successful redevelopment of the property.
• Brownfields Success Story: The Past Is Prologue for Taylor Colliery, Taylor Borough, Pennsylvania (EPA 560-F-17-224)
  Brownfields success story highlights how EPA assessment and cleanup grants were used in the cleanup of soil contamination at an abandoned coal mine colliery, leading to the active reuse of the site through the construction of housing and office buildings.
• U.S. EPA Making a Difference in Communities: California Gulch Superfund Site (Webinar Series | February 22, 2016) — For years, EPA has worked with the community of Leadville, Colorado, the Colorado Department of Public Health and the Environment, and other stakeholders to complete cleanup at the California Gulch Superfund site and return the site to appropriate use. The Superfund site encompasses 18 sq mi, including the entire town of Leadville. This video highlights how the cleanup of a portion of the Superfund site, combined with the community's leadership and support for bringing new recreational resources to the area, has resulted in development of the Lake County Community Park and Fairgrounds.
• RE-Powering America's Lands — EPA is encouraging renewable energy development on current and formerly contaminated land and mine sites when it is aligned with the community's vision for the site. This initiative identifies the renewable energy potential of these sites and provides other useful resources for communities, developers, industry, state and local governments or anyone interested in reusing these sites for renewable energy development. The site includes a variety of resources, including mapping tools and data for assessing the renewable energy potential for sites.
• Revegetation

Cleanup References

• Bralorne-Takla Mercury Mine: Innovative Risk Management and Reclamation
  Runnells, J., T. McConkey, T. Gillett, and B. Power.
  41st British Columbia Mine Reclamation Symposium 17-20 September, Williams Lake, BC, 2018
  In 2005, the Crown Contaminated Sites Program began assessing onsite wastes, equipment, and other materials at the historic Bralorne-Takla mercury mine. Investigations confirmed the presence of unacceptable risks to human health and ecological receptors. Remedial objectives were identified to return the mine site to forest ecosystem. Remediation included capping mine openings, demolishing structures, disposing of hazardous waste off-site, consolidating non-hazardous waste in 2 on-site landfills, revegetating, and implementing administrative risk controls to protect future site users. The cover design included innovative elements to support forest growth. Selection of native species for seed mix, shrub and tree replanting focused on returning the mine site to a forest ecosystem and supporting traditional use of the land. Monitoring covers, drainage systems, landfill gases, water quality, vegetation performance, and land use risk controls are ongoing. Additional monitoring includes ambient mercury vapor monitoring and biomonitoring.
• Reclamation of the McLaren Tailings: The Rest of the Story
  Bennett, M., T. Henderson, and A. Coleman.
  36th Annual Meeting of the American Society of Mining & Reclamation, 3-7 June, Big Sky, MT, 73 slides, 2019
  In late 1960, Soda Butte Creek was considered the most polluted stream entering Yellowstone National Park. The contamination source was the McLaren Tailings impoundment, constructed a former channel and floodplain of Soda Butte Creek from 1934 to 1953. A remedial design was developed to stabilize/remove 191,140 m³ of mine tailings, mine wastes, and impacted soils; construct an onsite repository, a site-wide dewatering system and water treatment system, and 1,219 linear meters (LM) of stormwater conveyance channels/infiltration systems; reconstruct 610 LM of Soda Butte Creek and Miller Creek; and revegetate 10 ha. The project turned a previously unusable area back to its historical landscape while cleaning up the contaminated Soda Butte Creek and preserving important fishery and natural resources of Yellowstone National Park. Construction began in June 2010, and the project was completed in fall 2015. After 4 years, the site is functioning as a stable landform. In 2018, the Montana Department of Environmental Quality delisted the creek from Montana's list of impaired waters 303d list. https://www.asmr.us/Portals/0/Documents/Meetings/2019/PowerPoints/1B_300_Bennett.pptx.
  See EPA fact sheet for more information https://www.epa.gov/sites/production/files/2018-11/documents/mt_sodabutte_1768_508.pdf

Demonstrations/Feasibility Studies References

• Land Application Disposal System Design for Biochemical Reactor Treated Effluent
  Anton, N.R., D.T. Shanight, C.S. Storrar, M.J. Fischer, E.M. Janoviak, and B. Lala
  36th Annual Meeting of the American Society of Mining & Reclamation, 3-7 June, Big Sky, MT, 26 slides, 2019
  At the mine waste repository for the Upper Tenmile Creek Mining Area Superfund site, Montana, collected leachate water has been managed in an active water treatment plant and pilot biochemical reactor system, with disposal to a land application disposal (LAD) system since 2003. In 2018, the design was completed for a full-scale leachate passive treatment system utilizing parallel BCR cells, post-treatment settling, aeration, limestone channels, and a gravity-operated LAD system. The new system construction will begin in 2019, and the existing water treatment infrastructure will be decommissioned after the new system is operational and functional. The presentation includes the critical passive treatment design components and provides details of the pre-design investigation and design approach for the LAD system, including field siting for the LAD, test pits, soil lithology logging, permeability testing, soil metal sorption studies, metal sorption capacity and water balance calculations, and hydraulic design of the LAD. https://www.asmr.us/Portals/0/Documents/Meetings/2019/PowerPoints/8A_1130_Anton.pptx
  More information: https://itrcweb.org/bcr-1/Content/Appendix%20B%20Case%20Studies/B15%20Luttrell%20Case%20Study.htm

General References

• Evaluation of Ecological Restoration Success in Mining-Degraded Lands
  Bandyopadhyay, S., and S.K. Maiti.
  Environmental Quality Management 29(1):89-100(2019)
  This review article analyzes the importance of assessing the success of ecological restoration using the assemblage of the plant and animal communities, enzyme activity, litter accumulation and decomposition, and the improvement of soil quality as indicators.
• Developing Diverse, Effective, and Permanent Plant Communities on Reclaimed Surface Coal Mines: Restoring Ecosystem Function
  Vasquez, E.A., and R.L. Sheley.
  Journal American Society of Mining and Reclamation 7(1):77-109(2018)
  This article focuses on lands to be reclaimed back to rangelands similar to pre-mine ecosystem in terms of plant composition/diversity, structure, and ecosystem function. Because plant functional groups can differ in their spatial and temporal acquisition of resources, improving functional diversity may be a method to more fully utilize soil nutrients in reclaimed soils and improve resilience to weed invasion. Strategically combining species with different seed/seedling traits in seed mixtures can increase chances of achieving adequate plant establishment during revegetation. Monitoring program design should be an integral part of the reclamation planning process, and indicators reflecting landscape-scale processes can be adapted to monitor reclamation project success. Effective reclamation plans are process-oriented, seek to initiate self-repair, and address landscape interactions. The probability of achieving successful reclamation is enhanced by pursuing a broader goal of improving ecosystem vigor, organization and resilience utilizing novel assemblages of species that perform desired functions and produce a range of ecosystem goods and services. Reclaiming mined land requires realistic objectives that consider the ecological potential of the site, land-use goals, and socioeconomic constraints. This article is Open Access at https://www.asmr.us/Portals/0/Documents/Journal/Volume-7-Issue-1/Vasquez-CO.pdf.

Research References

• Soil Reclamation of Abandoned Mine Lands by Revegetation in Northwestern Part of Transylvania: A 40-Year Retrospective Study
  Buta, M., G. Blaga, L. Paulette, I. Pacurar, S. Rosca, O. Borsai, F. Grecu, P. Ecaterina, et al.
  Sustainability 11(12):3393(2019)
  Researchers developed an ecological land restoration strategy to restore the ecological integrity of the 2 abandoned and disturbed mine lands in Aghiresu and Capusu Mare, in the Northwestern part of Transylvania. Soil quality changes were monitored over 40 years as a result of land restoration activities by examining 30 soil profiles and 450 soil samples collected from 3 depths (0-20 cm, 20-50 cm, and 50-80 cm). All the proposed plant covers (natural grassland, pasture cover, black locust, Norway spruce, and Scots pine) significantly improved the overall soil quality with the increasing years of reclamation following various patterns. Pasture cover most significantly enhanced the soil's microbial activity, organic carbon, nitrogen, phosphorus, and potassium content, followed by natural grassland. Results revealed that restoration of the vegetation cover on tailing dumps contributes to soil quality improvement through stabilization, pollution control, aesthetic improvement, and soil fertility. This article is Open Access at https://www.mdpi.com/2071-1050/11/12/3393/htm.
• Soil Amendments — Revitalization of a mining site may involve the addition of amendments to the contaminated soil. Soil amendments are materials added to soils in order to revitalize and make them suitable for sustaining plant life or development. Mining sites with contaminated or disturbed soils exhibit a variety of problems that often can be addressed effectively and directly through the use of soil amendments. Project managers could evaluate their effects in the subsurface, their potential for eventual transport to surface waters, and their possible subsequent adverse effects on plant and animal communities.

Research References

• Gasified Grass and Wood Biochars Facilitate Plant Establishment in Acid Mine Soils
  Phillips, C., K. Trippe, G. Whittaker, S. Griffith, M. Johnson, and G. Banowetz.
  Journal of Environmental Quality 45:1013-1020(2016)
  Biochars derived from the pyrolysis or gasification of biomass potentially can serve as a valuable soil amendment to revegetate mine sites. Biochars produced by gasification of either Kentucky bluegrass seed screenings (KB) or mixed conifer wood (CW) were investigated for mine soil amendment to support the growth of wheat plants in heavy metal-laden mine soils from the abandoned Formosa and Almeda mines, Oregon. Both KB and CW biochar amendments promoted plant establishment by increasing soil pH, increasing concentrations of macro- and micronutrients, and decreasing the solubility of heavy metals. Amending these soils with between 2% to 4% biochar (by weight) was needed to promote healthy wheat growth and reduce metals mobility.
• Microbial Functional Capacity is Preserved Within Engineered Soil Formulations Used in Mine Site Restoration
  Kumaresan, D., A.T. Cross, B. Moreira-Grez, K. Kariman, P. Nevill, J. Stevens, R.J.N Allcock, et al.
  Scientific Reports 7:564(2017)
  Recycling of mining site substrates can be achieved by blending the waste materials with native soil to form a novel substrate that can be used in future landscape restoration; however, these post-mining substrate-based soils are likely to contain significant abiotic constraints for plant and microbial growth. Using both marker gene and shotgun metagenome sequencing, researchers showed that topsoil storage and the blending of soil and waste substrates to form planting substrates gave rise to variable bacterial and archaeal phylogenetic composition but a high degree of metabolic conservation at the community metagenome level. Their data indicated that whilst low phylogenetic conservation was apparent across substrate blends, high functional redundancy was observed in relation to key soil microbial pathways, allowing the potential for functional recovery of key belowground pathways under targeted management.