Mining Technology

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Mine Waste Technology Provides Cleanup Solutions (PDF) (2 pp, 130KB, About PDF)

Issue

Mining of metallic ores, phosphate, uranium, and oil shale in the United States produces between one and two billion tons of mine waste annually. As a result, more than 600,000 mines, most of which are abandoned, have polluted 180,000 acres of reservoirs and lakes, and 12,000 miles of streams. Since many of the mines involve sulfide minerals, mineral mine drainage is a common problem from abandoned mine sites as well. The combinations of acidity, heavy metals, and contaminated sediment have severe detrimental environmental impacts on delicate ecosystems. Without remediation and reclamation of these mines, they will continue to discharge toxic metals in water and sediment.

Scientific Objective

The Land Research Program in the U.S. Environmental Protection Agency's (EPA) Office of Research and Development (ORD) develops and demonstrates innovative, cost-effective cleanup technologies for mine land. Engineering solutions, through laboratory research and field testing, address the environmental legacy of mining and smelting of metallic ores.

Scientists and engineers work closely with other EPA offices involved with Superfund remediation and abandoned mine lands and collaborate with colleagues in state government, universities, and private entities to develop new approaches to developing remediation technologies for mining wastes.

At ORD's Engineering Technical Support Center (ETSC), engineers and scientists provide assistance to EPA regional offices, states, and communities on the design, function, and application of technologies. A major challenge is treating millions of gallons of acid mine run-off in remote locations without ready sources of electricity doing it in a cost- effective and sustainable manner. For information about the center, visit this web site.

For the past 16 years, ORD's Mine Waste Technology Program (MWTP) has been fulfilling its role of developing new innovative remediation technologies that address remediation of hard rock mining sites and associated waste more efficiently and effectively. More than 90 projects have been completed and others are in progress. For more information on mine waste technology projects, visit the Mine Waste Technology Web site.

Researchers also study the complex environmental, social, and environmental issues at sites designated as Mine-Scarred Lands (MSLs) under the Brownfields law.

Application and Impact

ORD researchers have made significant contributions to solving the complex issues of mine remediation. Successful remedies included:

Passive and semi-passive acid drainage/water treatment systems
Innovative components for conventional water treatment
Permeable reactive barriers (PRBs)
Pit lake treatment
Source control
Trace metal removal
Cyanide destruction
Sustainability

Site characterization of mineral mine drainage and long-term management methods of drainage and emissions from abandoned mines and disposal sites are at the heart of ORD's research efforts.

Research Contributions

Cyanide Heap Biological Detoxification, Phase II
This technology was implemented at Barrick Gold's Cortez Mine in northeastern Nevada. Biological heap detoxification is a process that uses bacteria to detoxify a spent heap leach pad by destroying cyanide, nitrates, and sulfates and removing metals.

Sustainability of Substrates in Sulfate-Reducing Bioreactor Systems
In cooperation with the Colorado School of Mines, ORD is testing different configurations of bioreactors and various substrate materials on the same mine- influenced feed water. While the results of these test reactors are site specific, the data will provide some insight into the overall design of biochemical reactors. The project is the culmination of several years of research and development.

Permeable Treatment Wall
ORD designed a system at the Nevada Stewart Mine to provide an economical technology that uses the mineral, apatite, as a treatment media to passively remove zinc and iron from the discharge water flowing from an abandoned mine. The treatment media was placed into a fully contained subsurface retention basin for odor control, aesthetics, protection from vandalism, and prevention of damage from animals. Overall, the system effectively reduced the metals loading from the mine's opening or adit discharge.

More information on permeable treatment wall effectiveness (PDF) (382 pp, 14.6MB, About PDF).

Other References

Mine Waste Technology Research Web site

Grants for Research on Mining Impacts Web site

Contacts

David Reisman, Director
ORD Engineering Tech. Support Center
U.S .Environmental Protection Agency
Cincinnati, OH 45268
reisman.david@epa.gov
513-569-7588

Diana Bless, Manager
ORD Mine Waste Technology Program
U.S. Environmental Protection Agency
Cincinnati, OH 45268
bless.diana@epa.gov
513-569-7674