The water management system at Bulga Coal is designed to minimise the interception of clean surface water. The runoff is diverted back into downstream catchments therefore reducing the downstream impact. Surface water captured within the mining operation is reticulated into the raw water system and used in preference to Hunter River Water. Coal seam groundwater from the underground operation is also discharged into the Complex raw water system. Raw water captured on site is only ever released via the Hunter River Salinity Trading Scheme which is managed by the NSW Office of Environment and Heritage. Since 2007, drinking and showering water has been supplied from the Broke Potable Water Supply system.
The objectives of water management at Bulga Coal are to:
- Minimise the contamination of clean water runoff from catchment areas upslope of the operations
- Minimise potential effects of erosion and its associated impacts as a result of mining operations
- Securely contain mine water (groundwater and surface water which reports to open cut and underground mining areas), and other site water that comes into contact with areas disturbed by mining activities – including overburden emplacement areas, coal stockpiles and the Coal Handling and Preparation Plant area
- Maximise the re-use of mine water for onsite water use such as coal washing and dust suppression. Reusing mine water is preferred over using water from the Hunter River.
- Manage the discharge of excess water back to the Hunter River through careful management and in accordance with the Hunter River Salinity Scheme
Recycled water from tailings
Water recycling technology is being utilised at the Coal Handling & Preparation Plant, decreasing our need for fresh water and reducing tailings (waste).
A chemical called flocculant is added to the tailings which separates water from coal fines, allowing for the water to be recycled from the tailings dam back into the Coal Handling & Preparation Plant. This recovered water is then re-used for coal washing as well as dust suppression and equipment wash down.