Annual Report 2007 - Antofagasta plc

Corporate Social Responsibility continuedbeen improved by using reagents in water andcontinuous dust monitoring is carried out at themine camp and the neighbouring town of Sierra Gorda.CSR REPORTOsmosis plant at El Tesoro.EmissionsThe Group seeks to reduce air emissions and ensuregood air quality in and around its operations andprojects.At Los Pelambres, several initiatives for dust controlare used to counter dust emissions coming primarilyfrom the sands dam of the tailings pond, roads andthe crushed ore stockpiles. Dust particles of less than10 microns (PM10) are monitored on a regular basisin 12 areas located inside and outside the mine’soperations. The roads, mine area and stockpiles areregularly sprinkled with water and additives are usedon roads to capture dust particles. Beyond the mineoperation areas, samples are analysed to ensure airquality for the neighbouring communities includingCuncumén, Quelén Alto, Tranquila, Camisas andCaimanes. Current results show that the emissionlevels are below the limits set by law. Every effort ismade to minimise dust emissions at the port and theconcentrate stockpile and the conveyor systems aresubject to negative pressure conditions. The loading ofconcentrates is done by extendible arms with emissioncollection systems. Close contact is maintained withthe authorities and audits are conducted on acontinuing basis.Emissions of dust from mining operations and gasesfrom the leaching process at El Tesoro are controlledby its Environmental Management System whichreduces emissions into the atmosphere.Measurements confirm that the emission levelsremain below the PM10 limit. Dust control hasWasteThe Group’s activities generate mineral and nonmineralwaste. Mineral waste includes mined rockwith no economic value, tailings from the concentratorplant and leached residue from the heap-leachoperations. These materials are disposed of indesignated waste dumps or tailings dams forwhich environmental approval has been obtained.Non-mineral waste includes materials from processeswhich support mining and processing such as usedtyres and waste oils. The Group’s operations havesystems to dispose of industrial and hazardous wastesaccording to applicable legal requirements. Regularcontact is maintained with local authorities, the HealthService and the National Environmental Commission(“CONAMA”) and audits of waste management areconducted on an on-going basis.Environmental guidelines at Los Pelambres use apreventive approach and seek to minimise disturbanceof surroundings, pollution, the use of resources, andthe disposal of waste. An industrial waste managementprogramme categorises hazardous waste in accordancewith current standards and directives. For example,industrial wastes are recycled where possible or sortedand sold as scrap. A waste management plan to sellused lubricant oils to other companies for use as fueland in the manufacture of explosives was approvedby authorities and implemented. Los Pelambres alsocontinued its composting facility for processing organicwaste from the dining halls during 2007 and added avermicomposting process. This enabled more wasteto be treated and reduced the overall amount ofwaste. The disposal of heavy duty tyres is alsocarried out by a system of external recycling.Michilla has also been working to improve industrialand hazardous waste management and will presenta plan to the authorities for approval in 2008.Waste disposal considerations at ADASA arise fromboth the purification process for providing potablewater and the treatment and disposal of sewage.Water purification generates waste which could havean impact on the environment as it contains arsenic52Antofagasta plc Annual Report and Financial Statements 2007