Historically, underground hard rock mines are abandoned after the ore is mined out. Water then seeps into the fractures, mined out veins, and other mine workings where it combines with oxidized minerals to form sulfuric acid which then brings heavy metals into solution which then flows out as acid mine drainage (AMD). The AMD impacts the surrounding streams by providing a steady influx of acidic metal rich water, as well as surges of AMD from the collapse of underground dams where AMD has pooled. Such surges and sometimes all flows can be controlled by installing concrete plugs (bulkheads) in strategic locations. This webinar will address underground bulkheads in general and will present specific examples from Region 8 of bulkhead installations and water quality changes, including those at Dinero Tunnel, Pennsylvania Mines, and Captain Jack Mill sites.

Presenters:

Michele Mahoney, U.S. EPA Technology Innovation and Field Services Division (mahoney.michele@epa.gov or 703-603-9057)
Michele Mahoney is a Soil Scientist working on issues related to remediation and reuse of contaminated sites within EPA's Superfund program. In order to support practitioners, she researches and reports on knowledge related to treatment technologies for mining sites, use of soil amendments for remediation and redevelopment/reuse, ecological revitalization, ecosystem services, phytotechnologies, and urban gardening. Michele develops and delivers training for the world-renown EPA Clean-Up Information Network (www.cluin.org), particularly a Mining Webinar Series, and topics related to Superfund Redevelopment, Ecological Revitalization, Ecosystem Services, and Phytotechnologies. She also creates and manages content development for the EcoTools and Mining pages on CLU-IN.org.

Michele has worked with EPA for over 20 years. Prior to her current responsibilities, Michele served the Agency as the lead for food waste composting issues and as an environmental fate and ecological risk assessor for pesticide registration. Michele also has experience as a Contractor for EPA and a Laboratory and Field Researcher.

Michele earned a M.S. in Soil Science from the Washington State University, and a B.S. in Agronomy & Environmental Science from Delaware Valley University.

Joy Jenkins, Ph.D., P.E., EPA Region 8 (Jenkins.Joy@epa.gov or 303-312-6873)
Dr. Jenkins is the EPA Region 8 Superfund Remedial Project Manager (RPM) for the Captain Jack Mill and Nelson Tunnel/CWR Sites in Colorado and the Gilt Edge Mine Site in South Dakota. Her work focuses on abandoned mine lands cleanup projects. She worked as a consulting environmental engineer prior to joining EPA in 2010. She completed her Ph.D. in Civil Engineering, Environmental emphasis, at the University of Colorado Boulder working on source control measures to prevent acid rock drainage generation.

Jeff Graves, Colorado Division of Reclamation and Mine Safety (jeff.graves@state.co.us or 303-866-3567)
Director of the Office of Active and Inactive Mines, Colorado Division of Reclamation, Mining and Safety, Colorado Department of Natural Resources. Mr. Graves has been with the State of Colorado for 18 years. He designed and implemented numerous mine reclamation projects for the State of Colorado as a Senior Project Manager. Prior to employment at the State of Colorado, he worked as a staff geologist for 2 geotechnical engineering firms in the Denver area. Mr. Graves has a Bachelors of Science in Geology from the University of Colorado and a Masters of Engineering in Geological Engineering, with an emphasis in groundwater engineering, from the Colorado School of Mines. His interests include mountain biking, backpacking, mining history, American history, and spending time with his family.

Christoph M Goss, PhD, PE, F ASCE, Deere & Ault Consultants (christoph.goss@deereault.com or 208-331-9736)
Dr. Goss holds a BS in Engineering -Civil and a PhD in Mining and Earth Systems Engineering, both from the Colorado School of Mines. As a principal at Deere & Ault Consultants in Longmont, CO, his practice includes tunneling, underground mine design, and underground rehabilitation. Since 2000 he has worked on a variety of abandoned mines and water tunnels, evaluating and designing support rehabilitation and bulkheads.

Moderator:

Jean Balent, U.S. EPA Technology Innovation and Field Services Division (balent.jean@epa.gov or 202-566-0832)
Ms Balent is on the staff of the EPA's Technology Innovation and Field Services Division where she has worked to collect and disseminate hazardous waste remediation and characterization information since 2003. Ms Balent manages the Clean Up Information Network website and actively supports online communication and collaboration resources available to EPA. She formerly worked with the US Army Corps of Engineers Environmental Engineering Division in the Buffalo District. Ms Balent was also a member of the SUNY-Buffalo Groundwater Research Group where she constructed and tested large scale models of groundwater flow. Ms Balent has also conducted research relating to the Great Lakes, environmental remediation, and brownfields re-development. She holds a Bachelor's degree in environmental engineering from SUNY-Buffalo and a Master's degree in Information Technology from AIU.

Webinar Slides and References:

• Introduction for Michele Mahoney, U.S. EPA Technology Innovation and Field Services Division (1.50MB/PDF)
• Slide Presentation for Christoph M Goss, PhD, PE, F ASCE, Deere & Ault Consultants (97.6MB/PDF)
• Slide Presentation for Jeff Graves, Colorado Division of Reclamation and Mine Safety (38.7MB/PDF)
• Slide Presentation for Joy Jenkins, Ph.D., P.E., EPA Region 8 (34.0MB/PDF)

Webinar Slides and References:

• Introduction for Michele Mahoney, U.S. EPA Technology Innovation and Field Services Division (1.50MB/PDF)
• Slide Presentation for Christoph M Goss, PhD, PE, F ASCE, Deere & Ault Consultants (97.6MB/PDF)
• Slide Presentation for Jeff Graves, Colorado Division of Reclamation and Mine Safety (38.7MB/PDF)
• Slide Presentation for Joy Jenkins, Ph.D., P.E., EPA Region 8 (34.0MB/PDF)

Additional Resources:

• Captain Jack Mill EPA Site Profile
• Fact Sheet: Captain Jack Mill, Ward, Boulder County, Co
• EPA OSC Left Hand Creek Discharge Response Profile