Water input
We source water from many different locations, and these are usually dictated by the availability of water in the region in which we are operating.
Where our water comes from
Our water can come from groundwater, surface water, sea water or from dams on site. In addition, some of our water is recycled and sourced from outside our operations, such as water treatment plants.
We withdraw a mixture of fresh and poor quality water from the environment. Most importantly, the use of poorer quality water - such as salt water and waste water - is used where possible, in place of good quality (potable) water.
Our results
In 2007, we withdrew 785 billion litres of water - which is a three per cent increase from 2006 when we withdrew 763 billion litres. In 2006, about half the water withdrawn was fresh quality water and in 2007 fresh quality water accounted for over half the water withdrawn.
As there is generally a higher community and environmental demand for freshwater than poor quality water, we consider how much freshwater we withdraw to be one of our key indicators for our water performance.
For example, in 2006, almost half of the water used our operations was poorer quality water - mostly seawater - used for cooling power stations. In some cases, this saved fresh water resources.
In addition to the water withdrawn for mining and processing, small amounts were withdrawn for supply to external parties, such as towns, pastoral use and export. In 2007 this amounted to 33 billion litres, compared to 29 billion litres in 2006.
We imported 3.4 billion litres of recycled water from external parties in 2007, and 5 billion litres in 2006. Although this is a small amount at the Group level, importing recycled water at the operation level is often a successful method to reduce the dependence on freshwater. For example:
- Approximately 69 to 70 per cent of HIsmelt® water is recycled waste water from the Kwinana Water Reclamation Plant sewage treatment plant.
- Twenty to 38 per cent of Tarong's water is recycled from the neighbouring power station. Tarong's import of recycled water deceased in 2007 as a result of water efficiency programmes.
- Approximately 32 to 33 per cent of Kestrel's water is sourced from a neighbouring company's mine.
- Approximately ten to eleven per cent of Spring Creek's water is supplied from neighbouring coal seam methane producers.
Alcan's 2007 freshwater input was 190 billion litres, an eight per cent decrease from the 200 billion litre input in 2006. This was the result of improved water management at Alcan's Quebec hydroelectric generating facilities after installing control valves to automatically restrict water use during maintenance and shut down.