Mangoola manages water on site in accordance with the Water Management Plan, which incorporates an Erosion and Sediment Control Plan, Surface Water Monitoring Plan, Groundwater Monitoring Plan and a Surface Water and Groundwater Response Plan. Water Management at Mangoola is designed to fulfil the requirements of the Project Approval (06_0014) and the Environment and Protection Licence (EPL). The Mangoola Water Management Plan is designed to ensure that clean runoff is separated from runoff within disturbed mining and infrastructure areas. Erosion and sediment controls have been designed and implemented to ensure any runoff from disturbed areas is appropriately captured and managed.
We currently re-use saline and dirty water on site for dust suppression and in the Coal Preparation Plant. We also recover and re-use water from onsite tailings emplacement areas to minimise the volume of water required to be sourced from the Hunter River. We operate a site water balance which describes the inflows and outflows of water at the operation. This balance allows us to investigate additional opportunities to reduce site water demands and to maximise re-use of water onsite.
Objectives of water management at Mangoola Open Cut include:
- Ensure that the quality of water leaving the site meets the appropriate quality standards;
- Define the structures, strategies and procedures to be implemented to ensure that all environmental impacts associated with site water management are minimised, based on the principle of separating water streams into dirty, clean and saline water;
- Define a program to monitor and assess impacts on surface water and groundwater; and
- Define how the mine will mitigate and respond to potential impacts on surface water and groundwater.
The Mangoola Surface Water Monitoring Plan is designed to facilitate compliance with conditions in our Project Approval and EPL. Furthermore, this plan enables Mangoola to measure and assess changes in stream health and channel stability.
Surface water monitoring at Mangoola Coal is completed in accordance with Surface Water Monitoring Plan and includes;
- Monthly water quality assessment of 16 monitoring locations;
- Monthly stream flow monitoring of 16 monitoring locations;
- Annual water quality speciation analysis of 16 monitoring locations;
- Annual channel stability monitoring of Big Flat Creek and Sandy Creek; and
- Bi-annual stream health monitoring of Big Flat Creek, Wybong Creek and Sandy Creek.
The Mangoola Groundwater Monitoring Plan has been developed to facilitate compliance with the conditions of the Project Approval and groundwater licences. The plan enables us to measure, assess and respond to changes to the groundwater regime that may be attributable to mining activities. The groundwater monitoring program for Mangoola coal includes:
- Continuous monitoring of six existing boreholes collected on a weekly basis;
- Bi-monthly sampling of groundwater monitoring locations;
- Quarterly sampling of 15 Monitoring Program bores;
- Annual speciation monitoring of eight representative boreholes; and
- Quarterly sampling of five Big Flat Creek bores