Sustainable Development > Environmental Performance > Reclamation Reclamation |
||
 | ||
|
By the nature of the business, mining disturbs land; however, this disturbance does not have to result in long-term environmental degradation. We take our remediation and reclamation responsibilities seriously. Once a mine can no longer produce minerals or metals economically, we take the steps needed to close the facilities and restore the land to uses that benefit society, protect the environment and consider the economic and social effects on the local community. The planning for mine closure begins decades before a mine is expected to close. For new mining operations, we consider closure and post-closure issues from the inception of project planning. To accelerate reclamation at several properties, Freeport-McMoRan Copper & Gold Inc. created a reclamation services group with more than 200 employees and a fleet of equipment dedicated to contouring and capping old stockpiles, capping tailings and re-vegetating disturbed lands. Reclamation projects are in progress or scheduled to begin during 2008 in Bisbee, Jerome, Globe-Miami and Tohono, Arizona; Tyrone and Chino, New Mexico; and Climax, Colorado. Since 2004, we have spent approximately $20 million for the Tyrone IC stockpile reclamation project to improve protection of groundwater and storm water runoff while simultaneously recovering copper from low-grade ore placed there during past mining operations. It involved mining and moving nearly 34 million tons of a 300-acre stockpile, removing stockpile material from Oak Grove Draw to restore the historic channel and creating an environmental buffer zone. The remaining portion of the stockpile will eventually be re-sloped, capped and revegetated. Additionally, new storm water and groundwater protection facilities will be constructed in compliance with state and federal environmental regulations. Since 2005, we have spent more than $100 million on the reclamation of almost 2,400 acres of tailings at our Tyrone operation. This large earthworks project has included capping the tailings impoundments plus the creation of large drainage channels to reroute storm water from the capped areas. The post-remediation land will become wildlife habitat. At Chino, reclamation of about 2,000 acres of historic tailings will begin in 2008. The remaining Chino tailings will be reclaimed when concentrator operations (and tailings production) end. The Clarkdale Tailings Reclamation Project is located on private land near the Tuzigoot National Monument in Arizona. For years, rangers at the Tuzigoot National Monument would have to explain to visitors why an expanse of earth adjacent to the monument was seemingly discolored. They would state it was the tailings, or material left over after copper production, from former processing facilities at Clarkdale. We capped the Clarkdale tailings with a natural soil cover and reseeded the 129-acre site with native plants and grasses. Earthmoving and reseeding were completed in 2007. Grasses are already growing, but it will take many years for the vegetation to mature and to match the surrounding native landscape. The tailings contained very small quantities of some minerals that could impact the aquifer if rainwater was allowed to infiltrate through it. The soil cover is designed to absorb the rainfall, allowing it to naturally evaporate or to be consumed by vegetation through the process of evapotranspiration, thus protecting groundwater. A major voluntary reclamation project was completed in 2007 at the Ojos del Salado property in Chile. The focus was an old slag pile left behind by prior operations that date from the late nineteenth and early twentieth centuries (into the 1920s). This project included the removal of the slag pile (covering 6.5 hectares) and the relocation of the material (500,000 tonnes) to a waste rock dump located in nearby authorized facilities of Minera Candelaria. The site had become an illegal dump for household garbage, creating a health and safety hazard. The removal of slag and refuse, followed by site reclamation, improved community aesthetics and quality of life in the Tierra Amarilla community. In Indonesia, PT Freeport Indonesia has conducted comprehensive scientific reclamation studies and programs for many years in both the highlands and the lowlands areas to provide sound data on the options for land reclamation. Highlands. The highland ecosystem is shaped by environmental extremes that include very low nocturnal temperatures, high solar radiation during the day but with short periods of photosynthesis, heavy fog, high rainfalls and nutrient-poor soils. Plants growing there are highly specialized, having evolved to survive in these harsh conditions. Many of these have been found suitable for overburden stockpile reclamation, including local grasses and several species of rhododendron and mosses. Although many of the overburden stockpile areas around the surface mine will be active for another eight years, after which all mining will take place underground, we are committed to reclaiming areas of overburden each year when the areas are no longer necessary for operations. We monitor the performance of various planting techniques and modify the programs to enhance their long-term success. Through 2007, more than 50 hectares of disturbed land at the mine in the highlands has been revegetated. Lowlands. Our studies of tailings reclamation and establishment of demonstration plots on deposited tailings have demonstrated that tailings are not toxic to native forest and agricultural plants. The studies have also provided important information on the range of plant species that can thrive when grown in tailings media. The tailings deposition area in a zone called the “twin levees project,” where our Lowlands reclamation research and demonstration work takes place, continued to be an area of intense activity in 2007. These activities include an educational facility called the Natural Succession Discovery Park, plantations and food crops, cattle husbandry and a butterfly sanctuary. Much of the work in this area is performed by local contractors, who are improving their business skills and their knowledge of the environment. Through the end of 2007, more than 160 plant species had been successfully grown on soils containing tailings. A portion of the tailings passes through the tailings deposition area. The new estuary areas formed from these sediments are being naturally colonized by mangroves. Seven mangrove species, 45 species of crabs and shrimp, and several species of snails, clams, fish and marine polychaetes (worms) have been identified in these new estuary areas. To accelerate the primary succession processes, we have planted over 200,000 mangroves in the area. Survival and growth rates of these seedlings compares favorably with rates for similar programs. Mangrove swamplands are part of the native ecosystem and also provide a protective barrier for inland residents. When mining is completed, the tailings deposition area will be reclaimed in a manner considered acceptable to various stakeholders, taking into account appropriate consideration of environmental and social impacts.
|
||
Bottom Right: The Clarkdale tailings area early in the reclamation process.
A major voluntary reclamation project involving the removal of a 6.5 hectare slag pile left behind by prior operations was completed at the Ojos del Salado property in Chile in 2007.