As with noise, the dust emissions from the Bulga Complex operations are subject to strict limits contained in our development consents. Mine dust is generated from the disturbance of soil and rock material by equipment such as the dragline and shovel; bulldozing; blasting and vehicles on dirt roads. Dust is also generated from the wind blowing over exposed ground and stockpiles.
Current dust controls at the Bulga Complex include watering of haul roads, dust suppression sprays on coal stockpiles, planting of temporary cover crops on exposed areas and suspending operations in difficult weather conditions.
Recognising the importance of issues raised in the broader community relating to dust emissions, the Bulga Complex is implementing a number of dust controls to reduce our emissions. These dust controls include:
- 4 real-time dust monitors to be located in the village of Broke, Cobcroft Road, Bulga and Broke Road. The purpose is to provide effective monitoring of background dust levels and develop a proactive approach to managing our operations
- The use of dust surveillance cameras throughout the pit to minimise dust emissions
- Two early warning dust monitors located close to our operations. These monitors will provide real time dust levels to the control room.
- The use of chemical dust suppressants on haul roads throughout the pit
- Aerial seeding of former mining areas.
The Bulga Complex operates an extensive air quality monitoring system which includes 30 depositional dust gauges which are used to monitor larger dust particles that settle out from the air over approximately one month, referred to as depositional dust. These gauges are sampled monthly and results are used to determine insoluble matter and ash residue.
The air quality monitoring system also has 6 high volume air samplers that monitor concentrations of smaller dust particles which are airborne (suspended particles) for a period of 24 hours on every 6th day.
Results from the dust monitoring are reported quarterly on the website in the Environmental Monitoring Report and also reported in the Annual Environmental Management Report.
Hunter Valley Air Quality Monitoring Network
Xstrata Coal participated in a steering committee and working group with the Office of Environment and Heritage to implement the Air Quality Monitoring Network around Singleton and Muswellbrook. The network continuously measures the concentration of dust with a particle size of 10 microns; one micron is equal to one thousandth of a millimetre; at up to 14 sites throughout the region. The network also monitor wind speed and wind direction. Air quality data from the network is accessible around the clock at the Office of Environment and Heritage website: http://www.environment.nsw.gov.au/aqms/uhaqmnfaq.htm