How BLM AML Projects Work
BLM State AML Offices | Partnerships | How BLM AML Projects Work | Frequently Asked Questions | Glossary
BLM addresses physical safety and environmental hazards using a risk-based approach. The type of remediation activities performed at an abandoned mine site determines which regulations guide site activities. In general, BLM follows National Environmental Policy Act (NEPA) procedures when conducting activities to address physical safety issues and for those sites where activities have historic, cultural, or wildlife impacts. BLM implements the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process for sites with a release or the threat of a release of a hazardous substance.
Types of BLM AML sites include:
- Physical Safety Hazard Emergency Sites include accidents and deaths or the immediate potential for such tragedies on BLM-administered lands. Once BLM is notified of a physical safety hazard emergency the local authorities are contacted and appropriate emergency procedures are initiated.
- Physical Safety Hazards Sites include open shafts and adits (some concealed by deterioration or vegetative growth); unstable rock and decayed support structures; deadly gases and lack of oxygen; explosives and toxic chemicals (including illicit drug labs); highwalls; and open pits. More subtle hazards include encounters with wild animals (e.g., rattlesnakes, bears, mountain lions); exposure to diseases from bat droppings, hantavirus, radon and radiation; and toxic soil, water, and air contaminated with cyanide, lead, arsenic, mercury, and other toxins which may be inhaled through dust and particles or through contact with impounded acidic water.
- Water Quality Sites are those sites where a hazardous substance release has occurred, is suspected, or the threat of release exists. BLM generally uses CERCLA authority to address these sites, and can address physical safety hazards concurrently with the environmental remediation under CERCLA.
Physical Safety and Remediation Measures
BLM may take temporary measures to mitigate against physical safety hazards, such as by posting warning signs and fencing. Additional remedial measures include closure of adits and shafts, backfilling of highwalls, drainage of impoundments, removal of leftover equipment and debris, and revegetation to help offset erosion and improve stability.
If during the site characterization BLM determines that remedial activities may have historical, cultural, or wildlife impacts they must address these impacts in conjunction with the remedial activities. To mitigate impacts to bats, bat grates and cupolas are often installed.
Water Quality and Remediation Measures
Typical remedies for water quality sites include removing the source of the contamination, treating the contaminated water, and/or rerouting the flow of water. The cleanup activities performed at water quality sites are conducted under CERCLA authority and follow the CERCLA process.
Site Closure and Monitoring
When the remediation goals have been met the abandoned mine site is considered closed and BLM prepares a Closure Report. All sites will need to be monitored to ensure that the remedy remains in place as long as necessary and continues to achieve the desired result. Water quality sites will likely require at least periodic sample collection to determine if previously established water quality criteria have been and continue to be met.
Additional Information
BLM National Environmental Policy Act Handbook (BLM Handbook H-1790-1)
Major Environmental Laws
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