Details from our operations
Didipio has one tailings storage facility (TSF). The TSF has been designed to exceed compliance standards as stipulated in the guideline issued by the Philippine Department of Environment and Natural Resources and the Australian National Committee on Large Dams’ Guidelines on Tailings Dams.
Quality control and assurance of construction criteria and materials is undertaken by an independent engineering specialist with support from operational personnel.
Quarterly and annual monitoring has been implemented since the start of construction by an independent third-party technical expert. In addition, an external review was conducted by a separate independent third-party technical expert in October 2017.
Haile Gold Mine
The TSF at Haile was constructed and became operational in 2016 following final regulatory approval by the South Carolina Department of Health and Environmental Control (SC-DHEC), which holds jurisdictional authority over the facility through their Dam Safety Division.
We commissioned an independent technical expert to undertake a Final Construction Inspection Report and a Dam Safety and Structural Review Inspection Report. In addition, the SC-DHEC undertook technical reviews prior to granting approval to operate the TSF.
Waihi Gold Mine
Waihi has two TSFs, although only one is operation. Tailings deposits into the closed and rehabilitated second facility ceased in 2005.
Both TSFs were designed by an independent third-party technical expert in accordance with the New Zealand Society of Large Dams. Both TSFs have monitoring plans that are reviewed and approved by the local regulators and undergo extensive internal monitoring. They also have detailed annual regulatory reporting requirements in relation to the stability and performance of pollution controls and environmental effects.
Annual reviews of the construction and operation of the TSFs are undertaken by an independent project engineer. An expert peer review panel has been appointed to review
the annual monitoring program and completion of the facility. The panel comprises independent third-party technical experts appointed by the local regulatory bodies with
expertise in geotechnical engineering, geochemistry, groundwater and rehabilitation.
These annual reviews have been conducted since 1987 and cover the following information:
- design, construction, monitoring, performance and stability reports from embankment construction
- operation, maintenance and surveillance records for the period of review
- other internal and external reports related to operations and closure of TSFs, including reviews of compliance against the New Zealand Society of Large Dams (NZSOLD) New Zealand Dam Safety Guidelines.
Macraes has three TSFs, two are closed and will be rehabilitated and one remains operational. All undergo extensive internal monitoring and have detailed annual regulatory reporting requirements regarding the stability and performance of pollution controls and environmental effects.
The Macraes TSFs were reviewed by an independent third party technical expert, commencing in 2016 and completed during 2017. The review updated a similar assessment performed in 2011, and included design, operation and monitoring processes, and a risk assessment of the safety and stability of the tailings embankments based on their status. It also reviewed compliance against the New Zealand Society of Large Dams’ New Zealand Dam Safety Guidelines.