Reclamation/Revegetation

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 Freeport-McMoRan Copper & Gold
Reclamation and Revegetation
PT Freeport Indonesia is committed to reclaiming or revegetating disturbed land when it is no longer used for our operations. We have 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. International scientific experts and PT Freeport Indonesia staff have studied the ecology of the alpine ecosystem in our work area and have developed methods to produce planting stock for native species. Studies undertaken to date include ethno-botany, biodiversity of the sub-alpine and alpine ecosystems, the use of native mosses for pioneering reclamation strategies and tissue culture for propagating native alpine plants. During the year, Greg Hambali, one of Indonesia’s most renowned botanists, visited our site for a firsthand overview of the ongoing mine reclamation program.

Although many of the overburden stockpile areas around the surface mine will be active for another eight years when all mining will become underground, we are committed to reclaiming areas of overburden each year when the areas are no longer necessary for operations as we monitor the performance of various planting techniques and modify the programs to enhance their long-term success. Through 2006, more than 70 hectares of disturbed land at the mine in the highlands has been revegetated, although some of that area has since been reused for overburden management as the mine plan is modified to accommodate changes in conditions. However, the information gained from these trials provides the foundation for planning final reclamation. Most of the disturbed areas at the mine and mill in the highlands remain in active use and therefore are not yet available for revegetation.

The intensive studies conducted to date have identified many types of native highlands plant species that are suitable in reclamation. Current research is designed to improve survival of these species in the harsh conditions. During 2006, larger-scale trials focused on the use of nutrients to accelerate revegetation directly on a typical overburden surface.

We also commissioned an independent study on the potential use of sterile non-native species in the early stages of revegetation to stabilize slopes and improve habitat more quickly. Transplanting and natural succession of native species can then take place with no risk of non-indigenous propagation. At our area’s altitudes, native species are not plentiful and tend to be slow growers. The report on this study will be published in 2007.

Lowlands In the lowlands, reclamation research has repeatedly demonstrated that native species successfully and rapidly colonize naturally and grow on soils containing tailings. Soils containing tailings when ameliorated with a small percentage of organic material, are highly suitable for growing many agricultural crops. The objective of PT Freeport Indonesia’s reclamation and revegetation program in the lowlands is to speed the transformation of soils containing tailings in the deposition area into agricultural and/or other productive land use or to return the soils to native vegetation after mining is completed.

The tailings area between the Twin Levees where our Lowlands Reclamation research and demonstration work takes place continued to be an area of intense of activity in 2006. The activities include the Natural Succession Discovery Park; cattle raising; plantations of bamboo, matoa, eucalyptus, coconut, and king grass; a butterfly sanctuary; a model airplane aerodrome, and growing edible fruits and vegetables. Much of the work in this area is handled by local contractors, who are improving their business skills and their knowledge of the environment. These activities are sampled for monitoring purposes and the areas are used as part of our Public Education and Awareness programs.

Through the end of 2006, more than 160 plant species had been successfully grown on soils containing tailings. Plant species that have been especially successful include legume cover crops for fodder; local trees such as casuarina, matoa, eucalyptus and coconut; agricultural crop plants such as pineapple, melon and banana; and vegetables and grains such as chili peppers, cucumbers, tomatoes, rice, string beans and pumpkins. Similar to previous years, edible plants and fruit from many of these species were harvested in 2006.

 


PT Freeport Indonesia’s comprehensive sampling program monitors environmental conditions in the tailings deposition area. There were 113 samples from 57 varieties of edible plants and fruit collected during the year for metals uptake analysis. Rigorous testing performed on these edible plants and fruits continues to demonstrate that metals uptake from the minerals naturally contained in the tailings is minimal and levels remain well below the maximum allowable levels stipulated by national and international standards.

Our reclamation plan is based on the PT Freeport Indonesia Five-year Reclamation Plans, which have been submitted to the Department of Energy and Mineral Resources. Approximately 50 hectares of tailings deposition area were reclaimed during 2006. About 15 hectares of legume cover crops were planted inside the areas planted with Casuarina sp., Pometia pinnata and coconut trees. Monitoring of the growth of these trees continues to indicate excellent progress. In order to prevent erosion, vetifer grass (Vetiver zizanoides) was planted at the edge of the Ajkwa River on about 12 hectares. An additional 2.5 hectares was hydroseeded in the levee area for erosion control. Eucalyptus and local species were planted on five hectares in this area. An animal husbandry program has been developed in the lowlands to demonstrate that cattle can be raised and grazed on deposited tailings. In cooperation with the local government, we are monitoring the health of the cattle. King grass, legume cover crops, and Koronivia grass were planted on 15 hectares in this and adjacent areas in 2006. Presently about 100 head of cattle are being raised in this program.

In one demonstration project, two types of legume cover crops (Colopogonium muconoides and Centrosema pubescens) have been planted for use as biomass to accelerate the formation of soils in the tailings area. The legumes are also nitrogen-fixers that add nutrients to the soils containing tailings. In addition to the production of commercial crops, another strategy of tailings reclamation is to encourage natural ecological succession— the natural regrowth of native species — in designated areas. Natural succession occurs quickly in many parts of the tailings deposition area. Phragmites grass produces detrital biomass that enriches soils containing tailings. This process also improves water retention capacity of the soils so that other species can propagate.

An independent research project on natural succession of native vegetation on tailings in an area outside the current deposition area, but which previously received tailings, found that in a period of only a few years, 264 plant species have naturally re-colonized and are growing well. This aspect of tailings reclamation has been observed and studied by PT Freeport Indonesia for years, but the formal confirmation and documentation of this process by independent scientists is significant.

A fraction of the tailings pass through the tailings deposition area. The new estuary areas formed from these sediments have been 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, PT Freeport Indonesia in 2002 initiated an assisted mangrove colonization program. Through 2005 and 2006, nearly 140,000 mangrove trees were planted. Survival and growth rates of these seedlings compares favorably with rates for similar programs reported in the literature. Mangrove swamplands are part of the native ecosystem, and also provide a protective barrier for inland residents.

New Life Takes Flight on Reclamation Plot
Norris Pangemanan is a safety engineer with a passion for life. He spent a long career with Freeport Indonesia working to save lives by enforcing safety regulations and teaching safe work practices. Today, he celebrates new life on an almost daily basis. Pangemanan helped to build and now manages a butterfly enclosure at the Maurujaya Reclamation Center. The butterfly sanctuary is a very popular destination for school groups and visitors to the Freeport Indonesia mine project. In fine weather, hundreds of spectacularly colored butterflies, including several endemic Ornithoptera (bird-winged butterflies) species, take flight in search of meals of flowering plants in the warm, humid climate of the enclosure.
A native of Manado, North Sulawesi, who first joined the Freeport organization in 1975, Pangemanan is the resident expert on the brilliant endemic species of Papuan butterflies. When PT Freeport Indonesia’s Environmental Department set out to publish The Butterflies of Mimika in 2001, they knew where to start. Pangemanan worked with Australian butterfly expert Robert Gotts to research and publish the book, which has become part of a growing collection of Papuan biodiversity research publications based on work conducted in the Freeport Indonesia project area with the company’s assistance.

“I first became interested in butterflies back in 1980 when visiting a sanctuary in Cairns, Australia,” Pangemanan reminisced. “I realized that some of the species that attracted most of the attention among the tourists were similar to some of the species that are present here in Papua.” It was after that visit that Pangemanan’s casual interest in butterflies grew into first a hobby, and then a passion.

Now retired from his safety career, Pangemanan spends most of his spare time tending to thousands of caterpillars, pupae and butterflies at the enclosure. The butterfly project was added to the reclamation center a year ago. Pangemanan says that it has added new life to the center. “Until now, the reclamation project has focused on flora. This introduces an important part of the natural fauna and is a signal that the forest is good here,” he adds.

The project is built on deposited tailings in an area that was once part of the active deposition zone. The butterfly is a fitting metaphor for the rebirth that is taking place on the area that was only a few years ago part of a barren sandy plain. The caterpillar enclosure sits among cash crops, native fruit trees and fish ponds that are thriving on tailings sand. “There is a good source of water, soil and nutrients in the tailings deposition area, which is a strong signal for the future,” Pangemanan says.

The enclosure houses hundreds of insects at the various life stages, from crawling caterpillars to magnificent winged creatures. Because of the life that thrives inside, the enclosure attracts other butterflies into the area. “What is happening now,” says Pangemanan, “is that the ecosystem here in the tailings area and the forest just outside is crossing over. Insects, birds and other animals are at home here just as they are in the forest on the other side of the levee,” he adds.

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