Managing soil salinity is critical for successful rehabilitation in the arid Pilbara. Our strategies include targeted leaching, selecting salt-tolerant native species, and continuous monitoring to restore ecological function and meet closure criteria.
Land RehabilitationImplementing the AS/NZS ISO 31000 framework ensures a systematic approach to identifying, assessing, and treating risks throughout the mine lifecycle, from operation to closure, enhancing decision-making and regulatory compliance.
Risk & CompliancePreventing AMD involves source control through selective handling of reactive materials, engineered dry covers, and water management systems to limit oxidation and infiltration, protecting long-term water quality post-closure.
GeochemistryPost-closure stability is ensured via instrumented piezometers, inclinometers, and remote sensing to monitor pore pressure and movement, providing early warning and verifying the success of slope remediation works.
GeotechnicalDeveloping a native seed bank and propagation program is key for biodiversity offset requirements. We establish on-site nurseries to grow local provenance plants, ensuring genetic integrity and successful revegetation.
EcologyAccurate financial provisioning, calculated using detailed closure cost estimates and updated regularly, is a legal requirement in WA to guarantee funds are available for final rehabilitation and ongoing monitoring.
Closure PlanningA PRCP is a regulatory requirement under the WA Mining Act, outlining a staged approach to mine closure and land rehabilitation. It integrates closure activities into the operational lifecycle, ensuring continuous environmental management. The plan details final landforms, waste facility stability, and revegetation strategies to achieve agreed post-mining land use objectives, reducing long-term liability.
Stabilization involves applying organic binders or hydromulch to prevent wind and water erosion. Strategic placement of windbreaks and contour ripping helps retain moisture and soil. We select and establish native, drought-resistant pioneer species to create a vegetative cover that anchors the soil, a critical step for successful long-term rehabilitation in low-rainfall environments.
The EPA (Environmental Protection Authority) guidelines mandate that decommissioning eliminates all significant environmental risks. This includes the safe closure of tailings storage facilities, management of acid-forming materials, and achieving a stable, non-polluting landform. The site must be rehabilitated to a condition suitable for an agreed sustainable future land use, with ongoing monitoring often required.
Key steps include designing a stable final landform with appropriate slopes, installing a durable cover system (clay cap, geomembrane) to limit water infiltration and oxidation, and establishing a vegetative cover to control erosion. Long-term monitoring of seepage, structural integrity, and water quality is essential to ensure the facility's safety and environmental compliance post-closure.
AMD risk is assessed through detailed geochemical characterization of waste rock and tailings. Management strategies include blending acid-forming materials with neutralizing minerals, installing impermeable covers to limit oxygen and water contact, and constructing engineered water collection and treatment systems. Monitoring groundwater and surface water quality is critical for decades after closure.
Final sign-off requires demonstrating that all closure criteria in the approved PRCP have been met over a sustained monitoring period. This includes evidence of landform stability, successful vegetation establishment, water quality targets, and the absence of ongoing environmental hazards. Regulatory bodies conduct a final inspection before releasing the company from its closure obligations and financial bonds.