Abandoned and Legacy Hardrock Mines

A long judicial history has made defining hazardous mining wastes quite difficult. Currently, RCRA has named 20 mineral processing wastes that are excluded from federal hazardous waste regulations. 

Due to the fact that each mine, depending on processes and desired commodity, may produce a different waste stream, it is difficult to list all chemicals of concern. Essentially, it is the responsibility of the concerned citizen to research the specific wastes from the mine in question. 

Here are some examples of typical contaminants for common mines: 

Gold – cyanide, cyanide – metals, heavy metals, and acid rock drainage 

Zinc/Lead – heavy metals, cyanide, and acid rock drainage 

Uranium – uranium and associated radioactivity, radon, arsenic, and lead 

What are abandoned mine lands?  

The EPA defines abandoned mine lands (AMLs) as “lands, waters and watersheds where extraction, beneficiation or processing of ores and minerals has occurred.” This term, unlike legacy hardrock mining, includes all legacy mines – including mines processing petroleum, coal, sand and gravel, and salt.  

Mining wastes pose a threat to Tribal communities in several ways that may not be obvious to other agencies, therefore, it is critical for Tribes to be engaged in the cleanup and redevelopment process. See EPA’s Abandoned Mine Lands: Site Information webpage for information about abandoned hardrock mines and mineral processing sites. 

EPA Abandoned Mine Lands Program 

The EPA Abandoned Mine Lands (AML) Program is coordinated through the Agency’s National Mining Team (NMT) and Abandoned Mine Lands Team (AMLT). These teams provide an EPA headquarters and regional core of expertise on issues at abandoned mine sites. The teams together serve as a focal point for coordinating and facilitating national technical, policy and process issues with stakeholders on abandoned/inactive mine research, characterization, clean-up and redevelopment activities. 

The goal of EPA’s AML Program is to identify ways to protect human health and the environment by using all of the non-regulatory and regulatory approaches available to the Agency. The EPA AML program defines AMLs as: “Those lands, waters, and surrounding watersheds contaminated or scarred by extraction, beneficiation or processing of ores and minerals, including phosphate but not coal*. Abandoned mine lands include areas where mining or processing activity is temporarily inactive.” 

*Although acid mine drainage/acid rock drainage caused by coal mining commonly results in significant environmental impacts, Congress has designated the Department of the Interior’s Office of Surface Mining as the Federal authority responsible for addressing these coal mining contamination problem 

Obtaining Technical Assistance and Support 

The Office of Surface Mining Reclamation and Enforcement (OSMRE) works with Tribes to ensure that citizens and the environment are protected during coal mining and that the land is restored to beneficial use when mining is finished, including reclaiming and restoring lands and water degraded by mining operations before 1977. See OSMRE information for Tribal governments. 

The Good Samaritan Remediation of Abandoned Hardrock Mines Act of 2024 allows qualified volunteers (“Good Samaritans”) to remediate abandoned hardrock mine sites by easing regulatory barriers and providing protections from previously discouraging environmental liabilities under the Clean Water Act, 1972, and CERCLA, 1980. Because many of the mining companies that created and abandoned the most dangerous legacy hardrock mine sites are dissolved, the Good Samaritan Act aims to promote the cleanup of legacy mine sites where no responsible party exists.  

Section §319(h) of the Clean Water Act (1979) offers funding opportunities for nonpoint source pollution via annual base funding and competitive grants. Funding awards can range from $40,000-$70,000 and up to $125,000 respectively. To be eligible, tribes must be federally recognized and obtain Treatment as State (TAS) status by the application deadline.  

The Abandoned Hardrock Mine Reclamation (AHMR) Program allocates small amounts of funding for reclamation or remediation projects on Abandoned Mine Lands (AML) due to legacy hardrock mining-caused environmental effects. The AMHR program includes AMLs on Federal, Tribal, State, and private lands. The program is a combination of federal funding for AMLs on lands managed by the Department of the Interior and the US Department of Agriculture/Forest Service, and grant programs for Tribes and States.  

US Department of the Interior’s Office of Surface Mining Reclamation and Enforcement’s (OSMRE) website provides information on mining laws, regulations, and guidance. This includes a summary of the Surface Mining Control and Reclamation Act enacted in 1977, and links to OSMRE’s federal register notices, compliance with the endangered species act, select executive orders, and select memorandum of understanding. 

EPA’s Abandoned Mine Lands Policy and Guidance webpage contains EPA policy and guidance documents that have direct applications to the assessment and remediation of abandoned mine lands. These policies and guidance documents must be taken in the context of the National Contingency Plan Overview (NCP), which is the overarching planning document governing Superfund actions. All policies and guidance documents are official Agency documents that reflect Agency approaches at the time of their issuance. 

Reference Guide to Treatment Technologies for Mining-Influenced Water (94 pp) highlights select mining-influenced water (MIW) treatment technologies used or piloted as part of remediation efforts at mine sites.