The nature of bauxite mining means large areas of flat land are exposed, which can be a dust source during windy conditions. Dust is also generated by truck movements and large tailings facilities, some located close to local communities.
A Dust Management Plan was developed in 2010 which included the development of a model which predicts dust spread within the airshed and determines the risk of impact on the community. This information is used in mine planning decisions. In late 2011, activities were enhanced with the installation of automatic dust monitoring stations at Nanum, Napranum and Rocky Point. A fourth station will be installed in 2012 at Sherger to provide baseline information. These stations enable real time monitoring of Total Suspended Particulate (TSP) matter and dust deposition (see Definitions). The stations send SMS messages to a member of the Environment team if dust levels are approaching licence limits and allow a much faster response time.
Responses to high levels of dust emissions can include watering haul roads or moving mine operations to another location until wind conditions change.
Deposited matter refers to any dust that falls out of suspension in the atmosphere.
Total Suspended Particles (TSP) refers to particles 50 μm (0.05 mm diameter) in size or less.
PM10 refers to particles 10 μm (0.01 mm) in size or less.