The Department of Energy, Mines, Industry Regulation and Safety (DEMIRS) has identified instances where mining tenement holders have failed to implement adequate stormwater control measures.
Recent investigations have found that inadequate drainage controls on and around waste rock dumps can result in significant environmental impacts, particularly following heavy rainfall events. Poorly managed runoff can transport fine sediments such as kaolinite clay into creek systems, affecting waterways and potentially harming riparian vegetation and aquatic ecosystems.
DEMIRS Executive Director Resource and Environmental Compliance Tyler Sujdovic emphasised the importance of proactive stormwater management and robust landform design to ensure compliance with environmental obligations and responsible resource development.
“Sediment pollution from waste rock dumps is a clear indicator of poor landform design and may prevent sites from meeting their mine closure objectives,” Mr. Sujdovic said.
“If not properly managed, waste runoff can introduce contaminants such as acid leachate, heavy metals, and saline water into natural watercourses, potentially harming riparian vegetation and the surrounding environment.”
To mitigate these risks, DEMIRS reminds all tenement holders of the need to:
- Implement well-researched, robust landform designs suited to waste material properties and climatic conditions.
- Conduct regular inspections of surface water drainage systems.
- Maintain sediment basins to trap runoff and reduce downstream impacts.
- Promptly address any erosion-related instability.
- Use monitoring data to inform future mine closure studies and improve rehabilitation practices.
DEMIRS will continue to monitor compliance and take enforcement action where necessary to ensure responsible environmental management.
Reports of environmental non-compliance in Western Australia’s resource activities can be submitted online.
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