Key Terminology

Acronyms

CEQ - Council on Environmental Quality
CFR - Code of Federal Regulations
EA - Environmental Assessment
EIS – Environmental Impact Statement
EMS - Environmental Management System
EPA - Environmental Protection Agency
FONSI - Finding of No Significant Impact
GPO – General Plan of Operations
MARRCO - Magma Arizona Railroad Company
NEPA – National Environmental Policy Act
NDAA – National Defense Authorization Act
NOI - Notice of Intent
RCM – Resolution Copper Mining
ROD - Record of Decision
TNF – Tonto National Forest

Mining Terms

Acid-Forming Materials - Earth materials that contain sulfide minerals or other materials that, if exposed to air, water, or weathering processes, form acids that may create acid drainage (as in potentially-acid-generating or reactive rock).

CAP Water - Fresh make-up water that is drawn either directly from the Central Arizona Project (CAP) canal or through pumping of groundwater available through banking of CAP credits.

Crushers - Machines that reduce large rocks into smaller rocks.

East Plant Site - Current exploratory shaft sinking site; historic Magma Mine site.

Flotation - Process of separating small particles of various materials by treatment with chemicals in water in order to make some particles adhere to air bubbles and rise to the surface for removal while others remain in the water.

Loadout Facility – A proposed facility where copper concentrate would be filtered to remove water and then sent to off-site smelters via rail cars or trucks.

MARRCO Corridor - Magma Arizona Railroad Company railroad corridor that begins at the Union Pacific Line at Magma Junction and continues to the town of Superior. The corridor would be used for water pipelines, concentrate pipelines, power and pump stations.

Panel Caving – An underground mining technique in which a series of horizontal tunnels are constructed below the ore body. The process begins with an initial round of explosives at the bottom of the ore body to break up the rock. Then rock is funneled downward and removed. The void created in the removal process allows gravity to continue forcing the ore body downward.

Slurry – Mixture of a fine-grained solid material – such as copper ore concentrate or tailings - and water.

Smelter - An installation or factory for smelting a metal from its ore.

Subsidence – The gradual caving in or sinking of an area of land. In the context of underground mining, subsidence is the lowering of the Earth's surface due to collapse of bedrock and unconsolidated materials (sand, gravel, silt, and clay) into underground mined areas.

Tailings – Finely ground rock fragments that remain after minerals (such as copper) have been removed from the rock by the flotation process.

Tailings Corridor – A proposed corridor that begins at the West Plant Site, ends at the Tailings Storage Facility, which would be used for water and tailings pipelines and access.

Tailings Storage Facility - The final storage area for unrecoverable and uneconomic metals, minerals, chemicals, organics and process water.

Waste Rock – Valueless rock that must be fractured and removed from a mine to keep the mining scheme practical and gain access to ore.

West Plant Site - Current site of water treatment plant, historic Magma Mine Concentrator and Smelter, legacy tailings/waste rock.

Snapshots Updated

The Forest Service is considering five reasonable action alternatives for a Tailings Storage Facility. To view Snapshot summaries and accompanying maps, click here.

View Updated Snapshots

EIS Status

Thumbnail image of EIS Status file

EIS Status graphic updated March 2018

Forest Points of Contact

Media & General Info
John Scaggs
jscaggs@fs.fed.us

Project Manager
Resolution Copper
Mary Rasmussen
mcrasmussen@fs.fed.us

Apache Leap Special Management Area
Apache Leap SMA website