Land and biodiversity
AWAC has a significant physical footprint which encompasses the land it uses and leases for mining, refining and smelting activities in:
- United States, and
- Saudi Arabia.
In the Darling Range in Western Australia, alone AWAC has mine leases for over 7,000 km2.
Land disturbance and rehabilitation
In regards to mining operations, AWAC operates under the mandate that mining is a temporary use of the land and it supports returning mined land to a sustainable future. In most cases that means returning the land to its pre-mining condition with the same diversity of plant and animal species.
Bauxite mining, which is done in relatively shallow pits, disturbs the land and disrupts its biodiversity. Mining accounts for the majority of land that is disturbed as a result of AWACs operations. As the joint venture is committed to minimising the disturbance of the original habitat and work closely with community and regulatory stakeholders to restore those lands we do impact to the most productive use possible, including, where feasible, re-establishing pre-operating conditions.
Some AWAC operations are within or adjacent to protected areas or sensitive bio diverse areas.
|OPERATIONAL SITE||SITE LOCATION & SIZE||POSITION||BIODIVERSITY VALUE|
|Huntly and Willowdale bauxite mines||Jarrah Forest, Western Australia - 712,900 hectares (1,761,614 acres)||Within protected area||Recognised by Conservation International as an international biodiversity hotpost; threatened species and ecological communities (International Union for Conservation of Nature - IUCN- and federal government listed)|
|Anglesea Power station (coal mine and power station closed in August 2015)||Anglesea, Victoria Australia - 7,221 hectares (17,843 acres)||Within and adjacent to protected area||Adjacent land zoned for conservation and listed on the National Estate Register; threatened species and ecological communities (IUCN and federal government listed)|
|Wagerup alumina refinery||Wagerup, Western Australia - 6,000 hectares (14,826 acres)||Contains portions of area of biodiversity value||Ramsar listed wetlands adjacent; threatened species and ecological communities (International Union for Conservation of Nature (IUCN) and federal government listed)|
|Portland aluminium smelter||Portland, Victoria Australia - 500 hectares (1,236 acres)||Adjacent to protected area||Threatened species and ecological communities (International Union for Conservation of Nature (IUCN) and federal government listed)|
|Juruti bauxite mine (railway and port facility)||Juruti, Brazil - 6,000 hectares (14,826 acres) that will be mined||Within protected area||Amazon rainforest and river; threatened species and ecological communities (IUCN listed)|
|Paranam bauxite mine (bauxite mine that ceased operation in October 2015)||Paramaribo, Suriname - 37,000 hectares (91,429 acres)||Adjacent to protected area||Adjacent to IUCN protected area; threatened species (IUCN listed)|
|Point Comfort alumina refinery (alumina refinery that was curtailed in 2016)||Point Comfort, Texas USA - 1,417 hectares (3,501 acres)||Adjacent to protected area||Native grassland and intertidal emergent marsh (protected under the Clean Water Act); threatened species (IUCN and federal government listed)|
In 2016, AWAC had three (directly owned and operated) active bauxite mining areas, one inactive bauxite mining area and one inactive coal mine. The 2016 total open area includes a number of inactive mines resulting from the cessation of mining in Suriname in late 2015 following full curtailment of the refinery. Also in 2015, the Anglesea coal mine ceased operation due to the closure of the Anglesea power station that used to feed the now closed Point Henry smelter. AWAC also has an equity interest in bauxite mines in Guinea, Brazil and Saudi Arabia however data relevant to those mines are not included in the information provided in this report.
In Suriname, AWAC’s Suralco operations developed an integrated closure planning framework to facilitate viable and sustainable future land use for mined out areas. Closure plans for five mine sites have been submitted to the Government of Suriname for review.
Mining operations at the Juruti mine in Brazil continue to innovate in rehabilitation practices. They have employed a nucleation technique for rehabilitation that which relies on locally adapted plants and animals colonising micro-environments. This has resulted in more rapid and effective restoration of disturbed areas.
Results and goals 2016
During 2016, progress was made in monitoring and reducing the collective mining footprint to the minimum required for efficient resource recovery.
AWAC’s Western Australian mining operations, the Juruti mine in Brazil and the Portland aluminium smelter in Victoria Australia have developed biodiversity action plans for their locations. These plans will be the basis for the development of similar plans at other locations. Three of AWAC’s mines that were active during 2016 or close to achieving or have achieved their minimum environmental footprint required for mining and mining infrastructure.
The Huntly mine in Western Australia is predicted to achieve its target by 2020. In 2016 open mine area increased due to a range of operational constraints at the Huntly mine. Mined areas at the previous crusher region of McCoy remained open due to a strategy to eradicate potential infection of haul roads by the pathogen Phytophthora cinnamonmi, which has the ability to kill many of the plant species in the jarrah forest. The backlog of open area is expected to be rehabilitated beginning in 2018 through to completion in 2020.
Legacy mined areas are reducing or eliminating; each of our mining operations is challenged to work toward the minimum footprints for active mining and supporting infrastructure agreed to in 2012; sharing best practices across our operations; and actively tracking and reporting upon progress.
Mining Land disturbed/Land Rehabilitated (hectares)
|OPEN MINE AREA||AREA DISTURBED ANNUAL||AREA REHABILITATED ANNUAL|
*expressed in hectares
The values in this table include some for Alcoa’s South American operations that do not form part of AWAC operations. However the vast majority of disturbance and subsequent rehabilitation is the result of AWAC’s mining and infrastructure activities. At the end of 2013, each mine provided actual data for the current year and projections through 2018 to facilitate the review of progress against the goals. In conjunction with this review, some of AWAC’s mining operations undertook more in-depth inventories of their open lands. Others have made significant progress in both reducing their current footprint and making aggressive projections for further reductions over the next five years.
Area disturbed for mining and associated infrastructure (hectares)
Area disturbed means annual land used in each reported year for mining or for mining infrastructure (eg. roads, shops, crushing equipment, conveyors). In Australia, the 2016 decrease was due to a return to more normal rates following the relocation of the crusher operations for Huntly Mine.
Area rehabilitated (hectares)
*Annual figures. Area rehabilitated means annual land returned to natural conditions or to productive use (such as farming) after mining or decommissioning of mine infrastructure in each reported year. The reduction in area rehabilitated in 2016 was mainly due to a range of operational constraints at the Huntly mine in Australia and reduced areas returned to the Government of Suriname during 2016.
The Rehabilitation Process
Mining of the bauxite ore results in relatively shallow open pits and requires excavating through several layers of soil and sub-soil. The top soil which is rich with seed and nutrient reserves is removed and retained for return to the mined area to re-establish native vegetation.
The overburden is then removed to expose the bauxite ore. The overburden may also contain valuable nutrients and microbes necessary to assist with regeneration. Generally the overburden and any rock removed together with the topsoil is returned immediately to the mine pit (progressive rehabilitation) however in some cases that is not immediately possible or practical and those materials are stored for later use.
Also, the topsoil can be treated with specially grown seeds and nursery-grown vegetation or, where the plant species are not prone to produce a viable seed bank, to supplement with cuttings and tissue culture propagation.
The rehabilitation process also includes creating an environment for native wildlife to return. This may involve creating habitats from tree trunks and stumps that were removed during mining. These habitats provide protection and an area to recolonise.
Continual review and research is conducted at rehabilitation sites to judge the success of techniques and processes. Research conducted at the Western Australian sites discovered that the establishment and longer-term survival of some species could be improved by reducing the rate of fertiliser applied.
Different rehabilitation processes and also employed at specific sites due to local conditions. At the Juruti bauxite mine in Brazil a nucleation technique is used which relies on locally adapted plants and animals colonising micro-environments using small mounds of topsoil to create an undulating land scape. This technique is used to help trap surface water and control water runoff during the wet season (300mm of rainfall).
Biodiversity management is a major part of the mine rehabilitation process. It is an essential practice for operations near regions where there are significant flora and fauna species (such as the jarrah forest Darling Range of Western Australia, and at Juruti near the Amazon in Brazil) areas recognised as sensitive eco-systems.
Decisions on future land use and preparation of rehabilitation plans are contingent on determining and maintaining the biodiversity of the area. In assessing the reconstruction of biodiversity in rehabilitated areas tree establishment and growth are regularly monitored. This includes reviewing the concentration of undergrowth and diversity. Regular reviews are also undertaken on establishment of birds, mammals, reptiles and insect life. Ground and surface water levels and quality is also monitored.
AWAC’s mining activities, although often limited to relatively small pits where bauxite exists, can affect a region because the pits must be connected by haul roads or conveyors. Alcoa work successfully to prevent the isolation of wildlife and the disruption of stream flows. We also maintain vegetation cover and the quality and quantity of both surface and groundwater. AWAC's Western Australia operations have extensive programs around the management of soil erosion, weeds, feral animals, and forest pathogens to minimize impacts on biodiversity.
Our mining operations can alter rainfall runoff patterns and surface and ground water hydrology. Alcoa monitor and manage these situations to preserve biodiversity. For example, frequent monitoring of more than 50 stream locations within AWAC's mining lease in Western Australia has revealed negligible impacts from mining activities on stream quality and biodiversity. AWAC’s manager Alcoa has committed to not explore or operate in World Heritage sites. They have also committed to avoiding legally designated protected areas where strict nature conservation is the management objective. Prior to developing an area, Alcoa conducts extensive evaluations of the areas biodiversity to determine future rehabilitation programs. Evaluations include monitoring plant growth, density and diversity. A review is also conducted of birds, mammals, reptiles and including insects.
All locations with substantive biodiversity values and land holdings had a sustainability target to develop a biodiversity action plan by the end of 2015 that:
- Identifies the biodiversity values of the land, including sensitive habitats and the presence of threatened species and communities, in context with surrounding land;
- Pinpoints potential impacts, both positive and negative;
- Develops a management plan based on the hierarchy of biodiversity mitigation measures—avoid > minimize > rectify > compensate
- Inform employees and communities where AWAC operates about the importance of biodiversity protection, and encourage their participation in biodiversity initiatives, and
- Set and report performance against site-specific targets.
Results and goals in 2016
Biodiversity action plans are in place for AWAC’s Western Australian mining operations, the Juruti mine in Brazil and the Portland aluminium smelter in Australia. They will act as blueprints for other locations to follow.