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Cumberland Resources Ltd. MEADOWBANK GOLD PROJECT. AIR QUALITY EIS. MEADOWBANK GOLD PROJECT. Air Quality Overview. Scope. Identify activities potentially impacting air quality Define type of air contaminants Calculate emissions and find their locatons Predict ground-level concentrations
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Cumberland Resources Ltd. • MEADOWBANK GOLD PROJECT AIR QUALITY EIS
MEADOWBANK GOLD PROJECT Air Quality Overview Scope • Identify activities potentially impacting air quality • Define type of air contaminants • Calculate emissions and find their locatons • Predict ground-level concentrations • Compare predicted concentrations to AAQO
Point Emission Sources • Power plant • 15.5 MW maximum power demand • three diesel generators plus one stand-by • atmospheric dispersion maintained by 30.5 m stacks • Primary crusher and mills
Mobile Emission Sources • Most of mobile sources will be trucks • Ore payload 90 tonnes, empty truck 60 tonnes • Maximum haul distance 7.5 km one way • Diesel supply for mobile equipment 11,200 m3/a
Fugitive Emission Sources • Tailings • Coarse-ore stockpile – 17 m high 44 m base diameter • Conveyors • Drilling and blasting
Air Pollutants • Sulphur oxides (SO2 and SO3) – sources: • - diesel engines (power plant, trucks, loaders, tractors) • Nitrogen oxides (NO and NO2) – sources: • - as above • Particulate matter (TSP, PM10, PM2.5) – sources: • - diesel engines, wheel entrainment, fugitive • Other contaminants: • carbon monoxide and carbon dioxide • unburned hydrocarbons
Dispersion Modelling • Dispersion modelling predicts ambient ground-level concentration of air pollutants • Model inputs: • emissions data (rate, location, source parameters) • meteorology, buildings, receptors data • Models outputs: • concentration isopleths • PM precipitation isopleths
Monitoring Monitoring of the concentration of suspended particulate matter in the air surrounding the major areas of activity (dynamic monitoring) with Partisol air samplers.
Monitoring Monitoring of the deposition rate of particles (static monitoring).
Mitigation • Processing Plant • The diesel power plant engines with low NOx emissions to prevent ozone formation and with low hydrocarbon emissions to lower greenhouse gas (GHG) emissions • Install dust filters at the primary crusher building and at fine grinding facilities (SAG mill and ball mill) and provide dust suppression equipment (dust covers, sonic sprays, etc.) • Install enclosure of feed conveyor to avoid fugitive emissions during windy weather • Transportation • Impose vehicle speed limit on Vault haul road to mitigate fugitive dust and reduce engine emissions • Apply dust suppressants (water, calcium chloride) to haul and service roads during dry weather to mitigate fugitive dust • Blasting & Waste Disposal • Limit blasting to calm days or use delay blasting technique; natural mitigation to take place when mining pits are from 85 to 175 m below the ground level; • Cover dewatered tailings with non-potentially acid-generating (non-PAG) aggregates to control wind erosion. • Miscellaneous Items • Use site-generated mineral material (dirt, aggregate, etc.) to cover disposed solid waste at the waste dump • Apply vegetation cover on stripped areas and long-term stockpiles.
Summary • Main air pollutants will include SO2, NOx and particulate matter • No hazardous pollutants will enter the atmosphere • Concentrations will comply with AAQO • Higher PM concentrations can be expected near hauling trucks and areas of mineral material discharges • Concentration of PM will be monitored • Mitigation methods will be implemented to keep low concentration of air pollutants