Background

Leadville Mine is a historic site located 15 km east of Dunedoo in the Central West of New South Wales. Once an active mining and mineral processing operation, the site has remained largely untouched since its closure in 1957, giving rise to ongoing environmental concerns.

In 2024, the NSW Government launched a comprehensive remediation project under the Legacy Mines Program, an initiative aimed at addressing the enduring environmental impacts of historical mining activities. The project prioritised contamination remediation and site safety improvements, with the goal of reducing risks to public health and safety, reducing any impacts to the environment, and to contain contamination at its source.

Our role and delivery

The success of the Leadville Mine remediation project hinged on effective collaboration among various government agencies, including the Department of Primary Industries and Regional Development, the Environmental Protection Authority, Crown Lands, Local Land Services, and Warrumbungle Shire Council. NSW Public Works (NSWPW) was appointed to deliver procurement, contract administration, and project management services, ensuring seamless execution from planning through to completion.

A robust procurement strategy was critical in selecting a contractor with the specialised expertise required for hazardous soil remediation and site recontouring. This capability was essential for redesigning the site’s drainage system to contain contamination within an on-site dam, a key environmental protection measure.

Additional remediation works included excavating contaminated soil and replacing it with clean material, enhancing drainage systems to manage surface water runoff, upgrading fencing to improve site security, and revegetating final landforms, including areas with residual contamination.

One of the most technically challenging aspects was the precise identification and removal of contaminated soil. To address this, technical consultants supported the project team using real-time X-Ray Fluorescence (XRF) scanning technology, which enabled accurate detection and mapping of contaminated zones for safe removal.

Further complexities arose during the redesign of the on-site dam. Initial assessments revealed that the existing clay material was dispersive and unsuitable for use as a liner. To overcome this, specialists developed a tailored solution: treating the clay with calcium and gypsum to improve its structural integrity, enabling it to function effectively as a containment barrier.

Outcomes and benefits

The completion of remediation works at Leadville Mine marks a significant milestone in advancing environmental safety and sustainability. Finalised in April 2025, the project successfully addressed key sources of contamination, particularly in high-risk areas. Where residual contamination remains, secure fencing has been installed to ensure long-term environmental protection and public safety.

Among the project’s major environmental achievements was the effective containment of contaminants through redesigned drainage systems and responsible waste disposal practices. The contractor prioritised sustainability by adhering to the Construction Environmental Management Plan and implementing material recycling initiatives. To safeguard both the environment and the local community, continuous dust and water monitoring was conducted throughout the construction phase.

Despite encountering unforeseen challenges, such as the discovery of dispersive clay, the project maintained a strong commitment to time, quality and environmental standards. It also met Aboriginal participation targets and supported local employment by engaging regional contractors for fencing, civil works, weed control, and water cart services.

Given Leadville Mine’s designation as a Registered Historic Site under the 2013 Warrumbungle Local Environmental Plan, all works were carried out with cultural sensitivity. An unexpected finds protocol was established and overseen by an independent cultural heritage expert, ensuring that heritage values were respected and preserved throughout the project.