Protecting and preserving the environment are core elements of Alcoa’s values and commit us to the highest standards of environmental performance.
We are acknowledged as a world leader in a number of environmental management areas and we strive for continual improvement.
Our Australian operations manage environmental issues using a comprehensive environmental management system certified to international standard ISO 14001:2015. Our refinery quality management systems are certified to ISO 9001:2008.
Mining rehabilitation and bauxite residue management are two key environmental priorities.
Alcoa is a recognised world leader in mine site rehabilitation (view video to learn more). Our key objective is to re-establish a self-sustaining jarrah forest ecosystem that fulfils forest land uses that include conservation, timber production, water catchment and recreation.
Our rehabilitation process, which has been developed and continually improved over decades, involves landscaping, pre-ripping, soil return, fauna habitat return, final contour ripping and seeding, recalcitrant planting, fertilising and ongoing monitoring and management.
We conduct annual monitoring of plant species richness to measure our performance. We first achieved our target of returning 100 per cent species richness to mined areas in 2001.
Alcoa is the recipient of numerous esteemed environmental awards including the Society for Ecological Restoration International Award for Outstanding Contribution to the Field of Ecological Restoration (2003).
Since mining commenced in 1963, we have cleared less than four per cent of our Mineral Lease (ML1SA) which extends from Mundaring to Collie. Alcoa does not mine in old growth forest.
Bauxite residue management
Bauxite residue is a by-product of alumina refining and consists primarily of iron and silica minerals. The coarse sand fraction (red sand) comprises approximately 40 per cent of residue and approximately 60 per cent of fine silt fraction (red mud). Much of the sand is reused to construct residue drying areas which are eventually capped and revegetated.
Long Term Residue Management Strategy
Alcoa has a Long Term Residue Management Strategy (LTRMS) for each refinery. These are designed to inform both government and community about our long-term planning and management strategies including the location of future residue drying areas; current plans for closure and future land use options; and current research into residue management and reuse. LTRMS reports are available here.
We are the first major alumina producer in Australia to use residue filtration. At our Kwinana and Pinjarra refineries residue filtration facilities force bauxite residue through very large filters that squeeze the water from the mud, with the water being recycled in the refining process. It used to be that all bauxite residue was deposited as slurry into storage areas and solar dried. Our filtration process extracts moisture from the residue, enabling it to be stored using stacking technology. This improves the overall efficiency and safety associated with stored tailings and reduces the amount of land required. It also gives these refineries the capability to reduce freshwater use by a collective 2.2 gigalitres (581 million gallons) annually. This is equivalent to the amount of water needed to fill 880 Olympic-sized swimming pools.
We continue to explore opportunities to use bauxite residue as a source material for a variety of applications. Our global refining research and development team has identified a number of possible sustainable uses including Red Sand™, a product that has been successfully trialed as a fill for industrial land development, turf top dressing, and in road base construction.
Further information about Australia’s environmental commitments and management can be found in Reports and Publications.