Water withdrawn from the environment
As a result of the target setting process undertaken in 2003, the amount of freshwater withdrawn from the environment per tonne of product has been selected as a key performance indicator for the Group.
Freshwater withdrawn
Fifty per cent (373 gigalitres) of total water withdrawn in 2005 was freshwater.
- Some operations only withdraw freshwater. For example, IOC's Carol Project and QIT’s Sorel, accounting for 58 per cent of the Group's total freshwater withdrawal, operate in areas of water abundance and currently only use freshwater. The Carol Project is planning to recycle poor quality tailings water, which will reduce the amount of freshwater withdrawn from the environment. Richards Bay Minerals, accounting for a further eight per cent of total freshwater withdrawal, mines heavy mineral sands from mine ponds. After use, water from the mine ponds seeps back into the aquifer, recharging it.
- In many operations, the use of poor quality water, including marine water, can reduce the need to withdraw freshwater.
The Group targets a ten per cent reduction in freshwater withdrawal per tonne of product between 2003 and 2008, based on efficiency improvements.
Freshwater withdrawn per tonne of product
Efficiency and intensity are parameters used to report the change in Rio Tinto's freshwater withdrawal performance. They are used in order to separate the effects of product mix change from underlying performance improvements:
- Change in efficiency is measured by changes in freshwater withdrawn per tonne of product (assuming there is no change in product mix); and
- Change in intensity is an indicator of how change in the mix of products alters Group wide freshwater withdrawal per tonne of product.
In 2005 Rio Tinto's freshwater withdrawal efficiency improved by 13.5 per cent from 2004. The main contributors to this increase in efficiency included:
- Production increases at IOC’s Carol Project achieved without proportional increases in freshwater withdrawal;
- Increased production of titanium slag and iron at Richards Bay Minerals and Sorel;
- Water efficiency improvements at Palabora and Northparkes;
- Reduction in the amount of freshwater used in ore processing at Pilbara Iron; and
- Reduction in the amount of mine dewatering at IOC’s Carol Project and Pilbara Iron
Compliance with water abstraction permits
Fifty three per cent of operations have a maximum regulatory allocation for water withdrawal. Two operations, Kestrel and Murowa Diamonds, exceeded their allocation in 2005.
- Murowa Diamonds withdrew greater than their allocated amount due to an increase in production and associated water demands. An allocation in line with the higher production rate is being sought for 2006; and
- Kestrel exceeded their public allocation by six per cent due to the limited availability of water purchased from third party providers requiring greater than the amount publicly allocated to be used. Opportunities to purchase additional water and to take more effluent from a neighbouring mine are being investigated for 2006.
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