Environment

Land management and biodiversity

Mining approach

Depending upon the location and depth of an ore body, there are a variety of engineering approaches that can be employed to develop a mine and extract the ore.

The ore body we must reach is more than 7,000 feet underground, making an open pit mine technologically infeasible. We will use a mining method called panel caving to access and extract the ore. A variation of block caving, panel caving allows for mining of very large ore bodies by dividing the mass into smaller strips or panels so that ore can be removed more safely and efficiently.

The Resolution Copper mining approach: environmental benefits:

No large open pits, small mining footprint
No overburden waste piles on the surface
Offsite smelting: Mined copper ore will be transported through a series of tunnels for offsite smelting. We are considering lands already impacted by previous mining operations as potential sites for our processing facilities and tailings areas. This means we can reduce environmental impact and help reclaim and restore lands for beneficial use.
Clean, efficient energy use: We are evaluating energy and water-saving technologies for use in our mining operations and are considering advanced clean-energy sources, such as geothermal energy from the mine itself.

Environmental risks

A potential risk of the panel cave mining method is surface subsidence or settling. Surface subsidence is caused as the material above the ore body gradually moves downward to replace the ore that has been mined.

Protecting Apache Leap

Stakeholders have expressed concern over the potential effects of subsidence and whether our mining operations could affect the area of Apache Leap, a culturally significant area of natural beauty. Resolution Copper is committed to protecting Apache Leap, both through legislative safeguards and close monitoring of subsidence. The company owns private lands around Apache Leap and has determined that adding its acreage to the exchange bill would best serve the public interest. The most recent version of the Southeast Arizona Land Exchange and Conservation Act transfers ownership of Resolution Copper's acreage to the federal government to be managed by the US Forest Service.

Close watch on subsidence

When mining starts, it will begin at a point away from Apache Leap. This will allow us to gather technical information over a period of years to reassess the cave angles and to ensure that Apache Leap is not impacted as mining progresses to the west. Methods to monitor subsidence include the following:

Seismic monitoring: Used to monitor cave progression by tracking the seismic energy that is released around its perimeter as it expands.
Displacement monitors: Installed down holes drilled from both surface and underground and used to sense any fracturing of the rock.
Tilt meters: Highly sensitive instruments that will be installed down short holes near the surface and will measure any tilting caused by the cave.
GPS, satellite imagery and laser scanning: surface-based monitoring that can be used to sense movements as small as 0.08 inches (2 mm).

This information will allow us to identify any possible threat to Apache Leap as a result of our mining activities. If a threat is identified, we will change our mining practices well in advance of any potential impact, thus ensuring that the area is protected.

Another key protection element involves the location of our mine infrastructure—it's between the ore body and Apache Leap. Consequently, our infrastructure would be impacted and our mining operations compromised well before any impacts to Apache Leap.

Rehabilitation

Resolution Copper has undertaken a major cleanup of the Superior-area site affected by previous mining operations. Reclamation costs absorbed by our company will exceed $50 million, and the majority of work involved is being completed by local contractors, thereby helping to support the local economy.

Our reclamation objectives are to protect human health and the environment from any legacy mining that may exist, restore the site to natural vegetation and re-establish the area for useful purpose.

As 2008 drew to a close, several different facilities had been reclaimed. These include one tailings impoundment, two stormwater ponds, a waste rock pile and several water conveyance features.

In November 2008, reclamation activities slowed significantly due to the economic downturn created by the global financial crisis. A small crew of contractors was retained to maintain the site and areas of reclamation that have already been completed. When the economy stabilizes and strengthens, we will once again step up our reclamation efforts.

Environmental and biodiversity partnerships

Resolution Copper teams with a variety of organizations to protect and preserve our environment and the species that inhabit these lands:

Arizona Trail Association - RCM employees and contractors volunteer to help build and maintain the Copper Butte Project, a 25-mile section of the Arizona Trail.
Audubon Arizona - The Rio Tinto Partnership Action Fund continues to help meet grant needs that support conservation and bird species protection.
Boyce Thompson Arboretum - RCM supports an after-school program that allows Superior elementary students to experience the beauty and diversity of their environment.
The Lower San Pedro Working Group - We are part of a working group of private businesses, nongovernment and government agencies formed to address long-term conservation issues facing the lower San Pedro River.