Water management
The increase in water use since 2002 is attributable to the incorporation of a number of large sites into the Xstrata Group following the acquisition of MIM in 2003 and subsequent smaller acquisitions.
Effective water management and conservation is critical to the long-term viability of many Xstrata operations, a number of which are located in dry, remote areas.
Xstrata's raw water use increased by 0.5% to 75,300 megalitres (ML) in 2005 compared with 74,900ML in 2004. Raw water use increased due to increased production of thermal coal, copper in concentrate and zinc, new projects commencing production and the incorporation of new sites, through the acquisition of African Carbon Group in January 2005. As a result of this acquisition and increased mine production, raw water use increased by 30% at Xstrata Alloys. The full impact of this increase was largely offset by exporting water from our water abundant mines to our water scarce mines and increased recycling at our smelters. Xstrata Coal offset 4,469ML of raw water use in 2005 through the construction of pipelines to share water across a number of its mines in New South Wales. At Mount Isa, excess water is exported for use in community facilities.
Overall, Xstrata's operations continued to increase use of recycled water year on year. In 2005 water recycled increased by 6% to 98,900ML. In particular, Xstrata Zinc operations recycled 55% more water than in the previous year primarily due to improved recycling in the concentrator at McArthur River Mine. This achievement was offset by Xstrata Coal's operations, where the quantity of water recycled declined by 18% overall, due to alterations at South African mines which reduced the capacity to store water and recycle it at these operations, and improved accuracy in monitoring recycled water.
Ulan coal mine's Bobadeen irrigation scheme is a unique solution that uses surplus mine water to irrigate 242 hectares of land specially planted with perennial pastures, which are maintained at an optimal level by beef cattle. Surplus mine water is first pumped to a holding dam and then to five centre-pivot irrigators. The pasture is kept at an optimal level by carefully monitored rotational grazing by beef cattle and the production of fodder. An industry first, this AUD7 million scheme uses approximately seven megalitres of water per hectare each year and has been heralded as an outstanding and sustainable solution to a complex salinity and water management problem (as set out in Xstrata's 2002 HSEC report).
Our operations at Mount Isa have a number of schemes in place to increase capture of storm water, including the construction of a 20 megalitre mine-side dam which began in early July after a feasibility study involving the X41 underground mine. The dam is designed to capture a one in 10 year rainfall event from its 60 hectare catchment area to reduce the likelihood of offsite discharge. A water recovery system will be installed at the dam to enable water to be captured and reused on site. Other initiatives include the use of a disused quarry, additional infrastructure, removal and capping of contaminated material within the catchment to improve the quality of storm water runoff. Stored storm water is used for dust suppression and to replace raw water wherever possible. Also at Mount Isa, where a number of departments operate at the same site, water consumption is directly charged to operational departments (‘user pays' principle), inherently promoting the use of recycled water.