Abandoned mine lands are those lands, waters, and surrounding watersheds contaminated or scarred by the extraction, beneficiation or processing of coal, ores and minerals. Abandoned mine lands include areas where mining or processing activity is determined to have ceased.
AMLs exist across private, mixed, and federal lands adding to the complexity of the issue. A number of federal statutes address environmental contamination issues associated with AMLs. Federal statutory authority is spread among several agencies with no one agency having overall statutory responsibility. Ensuring that appropriate authorities are used at AML sites will work to facilitate cleanup.
There are many types of mines, each with their own unique characteristics, making cleanup efforts varied, both in terms of cost and approach. The three main types are coal, hardrock, and uranium.
Abandoned Coal Mines
Most abandoned coal mines are found in the East and tend to be small to medium-sized. Sixty percent of these mines can be found in just three states: West Virginia, Pennsylvania, and Kentucky. Larger sites are found in the West, though in much smaller numbers. Most abandoned coal mines are located on State-owned land. These sites also tend to be in closer proximity to populated areas. Many times, homes and other buildings have been constructed on top of underground mine workings and subsidence can become a problem.
The Office of Surface Mining Reclamation and Enforcement (OSM), within the Department of the Interior, is the primary Federal agency responsible for abandoned coal mine reclamation. A national program, established by 1977 law, is in place that includes an inventory of high priority sites, a reclamation fee paid by the coal mining industry, and a funding mechanism comprised largely of grants to States and Indian tribes with approved programs. Priority focus is on sites posing health and safety hazards.
There is an inventory of high priority abandoned coal mines maintained jointly by OSM and program States and Tribes.
Abandoned Hardrock Mines
These are primarily ores and metals (e.g. gold, silver, copper, lead, zinc, nickel). Most are small to medium in size, though there are a handful of large, significant sites. These sites are predominately in the West, which gave rise to the establishment of cities and towns during homesteading (Westward population expansion). The majority sits on or adjacent to Federal lands and often involve “mixed-ownership.” Many of these sites have been “patented” to mining claimants and are now on private lands.
No single national AML program exists; rather, several authorities and multiple departments and agencies address hardrock AML sites as part of broader programs. Similarly, funding for remediation projects is spread among separate appropriations for participating departments and agencies. Federal and State agencies are doing more than ever before to display their spatial data and exchange information. Data from the former U.S. Bureau of Mines and the U.S. Geological Survey provide the foundation of most hardrock mine inventories.
There is a “polluter pays” principle that requires the Federal government, where possible, to compel responsible parties to clean up their sites or help cover the costs. Priorities focus on water quality and sites involving release or potential release of hazardous substances.
Abandoned Uranium Mines
The uranium mining industry began in the 1940s primarily to produce uranium for weapons and later for nuclear fuel. Although there are about 4,000 mines with documented production, a database compiled by EPA, with information provided by other federal, state, and tribal agencies, includes 15,000 mine locations with uranium occurrence in 14 western states. Most of those locations are found in Colorado , Utah, New Mexico, Arizona, and Wyoming, with about 75% of those on federal and tribal lands.
The majority of these sites were conventional (open pit and underground) mines. The mining of uranium ores by both underground and surface methods produces large amounts of bulk waste material, including bore hole drill cuttings, excavated top soil, barren overburden rock, weakly uranium-enriched waste rock, and subgrade ores (or protore). At some abandoned mine sites, ore enriched with uranium was left on site when prices fell, while transfer stations at some distance from remote mines may contain residual radioactive soil and rock without any visible facilities to mark their location.
While most pose minimal radiation risk to the public, since exposure is most likely to be short and intermittent (e.g., visitation, recreation), they may pose other physical safety risks.
There are a plethora of other kinds of mines such as iron and phosphate, and there are thousands of sand, gravel, and clay pits and quarries that are not addressed by Federal abandoned mine lands programs. Contact your State and local authorities if you are seeking information about these sites.