Newcrest’s tailings storage facilities are audited against criteria that aligns with industry guidelines and specifically against the Australian National Committee on Large Dams (ANCOLD) guidelines.
All of Newcrest’s operations have a program of annual external audits. Like most major mining companies, Newcrest commissioned a series of independent audits of its tailings storage facilities following the Samarco event in 2015.
In response to Cadia’s Northern Tailings slump in 2018 Newcrest is conducting even more extensive reviews on all its tailings storage facilities. Read the findings of the independent review into the technical root cause of the slump, which have all been accepted by Newcrest.
At Cadia we have conducted investigative drilling near tailings storage facility walls with a significant number of samples tested and analysed. There has been a detailed review of the geological mapping. Engineering work conducted over life of tailings wall has also been reviewed.
In 2018 Newcrest commenced construction of buttresses in two areas of the Southern Tailings Storage Facility (STSF), which have now been completed. In designing this buttressing, Newcrest and its external engineers have assumed the potential presence of weak material analogous to that in the area of the Northern Tailings Storage Facility (NTSF) slump and adopted conservative strength parameters.
We are also concluding the design of future STSF raises to progressively move from upstream to centreline. Construction is planned to begin in late 2020. Meanwhile, our work is progressing on the repair plans for the NTSF.
Investigations to reconfirm the TSF design at Telfer began in May 2018, under the supervision of acknowledged industry experts. As part of this investigation, cone penetrometer tests have been conducted on the TSF to validate design assumptions. Work is ongoing in relation to ensuring the stability of the Telfer TSF.
Tailings storages with upstream construction have been subject to analyses to confirm the engineering characteristics of the tailings and with a view to confirming tailings saturation. Several dams have been reinforced with buttresses or are now subject to panel review where such has been recommended.
Our strong commitment to the safety of people and care for the environment underpins our approach to managing our tailings facilities. There is nothing more important to Newcrest than everyone going home safe every day, the safety of our local communities and the environment.