Environmental performance

Compliance with all laws and regulations is the foundation on which our environmental performance is built. Significant non-compliances, including spills and other discharges to the environment, are reported principally through our incident reporting system. Significant environmental incidents are defined as any occurrence that has actually resulted in or had the potential to cause at least moderate environmental impact. Non-compliances that result in a failure to meet legal requirements may also result in fines and prosecutions.

There were 663 environmental incidents during the reporting period. Of these, 26 (4 per cent) were significant incidents and 637 (96 per cent) were non-significant. None of the significant incidents were rated as causing or having the potential to cause major environmental impact. Forty incidents (6 per cent) were required to be reported to a regulatory authority, generally either because of their high significance or due to the specific requirements of the local operating licence.

Of the 26 significant incidents, one incident saw a load of regulated waste catch on fire during road transportation. Sixteen significant incidents involved the discharge of water from our mine sites, five incidents involved the spillage of product, tailings or sediment outside of their containment areas, and four incidents involved the loss of hydrocarbons or chemicals to the environment. These included:

• At the Golden Grove operation in Western Australia, approved mine water discharge to Lake Wownaminya exceeded the discharge licence limit for cadmium for 12 samples collected throughout the year. Upgrade of the mine water treatment system is underway. No toxicological effects on the local ecology have been defined to date, with impact monitoring ongoing
• A temporary sediment control structure that was under construction at the Phavat deposit, Sepon, failed due to heavy rain and resulted in the uncontrolled release of sediments into the creek system. Activities at the immediate site were stopped for 24 hours until an approved interim structure was constructed and signed off
• Approximately 16 tonnes of lead concentrate spilt to the ground when a truck carrying the concentrate rolled the last of its three trailers whilst en route from the Century mine in northwest Queensland. The incident occurred during the night when the driver of the vehicle swerved to avoid hitting kangaroos. Concentrate trucking was immediately suspended and cleanup of the site commenced the following day. A soil testing program to ensure appropriate cleanup standards was implemented in consultation with the Queensland Environmental Protection Agency
• During the excavation of a pit during upgrade of the Izok camp facility in Nunavut, Canada, a 200 litre drum of fuel was found buried in what appears to have been a historical landfill site. Oil texture and odour in the soil suggested that an undetermined amount of fuel had been lost from the drum. The drum and impacted soil were recovered and containerised for transport off site
• The incorrect installation of pipe work for a bulk fuel tank at Prominent Hill resulted in 1,100 litres of diesel overflowing from the emergency vent onto the surrounding ground. As soon as this was discovered the generator was removed and the tank emptied. The contaminated area was contained with a dirt bund and all contaminated material was removed to the bioremediation area

Sixty one exceedances of licence limits related mainly to water discharge were recorded. At the Avebury mine, which OZ Minerals acquired in July 2008, 38 exceedances in 11 water samples were reported to the Tasmanian Government. These discharges were judged not to have had a major environmental impact. The company is liaising closely with the regulatory authority to review the water discharge quality program and amend the current water discharge limits so that they are more appropriate to the local environmental conditions and actual potential for environmental impact.

No fines or prosecutions arose from the incidents recorded during the reporting period.

Investigations were conducted into all significant incidents to ensure that the factors that contributed to the incident were identified and additional controls were implemented to prevent a recurrence.