Sustainability

Dams and tailings management

Newcrest recognises good environmental practice as critical to building operational performance and building community trust and acceptance.

Newcrest’s aspiration is to be a leader in tailings management with an ultimate goal of zero harm to people and the environment.

As members of the International Council of Mining and Metals (ICMM), Newcrest is working towards conformance to the Global Industry Standard for Tailings Management (GISTM), for all the tailings storage facilities (new, active or in active).

Background

Tailings are the resulting material from finely-ground processed ore bearing rock that has been through several sizing, grinding, and processing steps.

Tailings are discharged as dense slurry into containment areas known as tailings storage facilities (TSF) or through lacustrine or deep sea tailings placement (DSTP) in suitable locations. Modern gold and copper processes seek to maximise the extraction of economic minerals, chemicals and reagents before the tailings are deposited.

Under Newcrest’s World Gold Council membership, Telfer and Lihir are certified to the International Cyanide Management Code, while Red Chris, Brucejack and Cadia do not use cyanide for processing.

Tailings Storage Design

Every mine location is unique with tailings facilities designed to account for a range of considering factors including:

  • Local topography;
  • Climate;
  • Geotechnical and geological conditions;
  • Potential seismic activity,
  • Proximity to people and infrastructure;
  • Land rehabilitation and;
  • Future land use considerations.

The three main TSF construction methods are:

  • Downstream construction involves raising the dam by placing fill on the downstream side of the initial embankment. This construction method requires the embankment to be expanded over previously undisturbed ground and requires the largest amount of fill for a given height increment.
  • Centreline construction also requires fill to be placed on the downstream side of the embankment, but the raised crest remains vertically in line with the previous crest. This construction method requires less fill than the downstream method but relies on the support of the upstream tailings to some degree.
  • Upstream construction involves embankment construction over previously deposited tailings and relies on the strength of the tailings for the stability of the embankment. This construction method uses the least amount of embankment fill and does not require the footprint to be expanded.

Tailings facility embankments are either continually or incrementally raised in layers or lifts to contain the tailings generated by the operation and to minimise the area of land disturbed by tailings placement.

NEWCREST TAILINGS FACILITIES

As of 30 June 2023, Newcrest had 12 terrestrial tailings storage facilities.

  • Four tailings facilities in active use;
  • Two tailings facilities inactive and under short-term care and maintenance with operations resuming following improvements and;
  • Six tailings facilities under long-term care and maintenance.

The tailings facilities at each site are:

  • One tailings storage facility in operation at Red Chris, contained by two dams, based on centreline design.
  • Two facilities in operation and six smaller facilities no longer in use at Telfer. 
  • Three facilities at Cadia.
    • Cadia Hill open pit is being utilised to store tailings.
    • Northern Tailings Storage Facility (NTSF) and
    • Southern Tailings Storage Facility (STSF).

In Ecuador, Newcrest has an equity interest in Lundin Gold which operates the Fruta Del Norte gold project and its downstream-constructed TSF.

Given a lack of suitable terrestrial tailings storage options, high rainfall and frequent seismicity at Lihir, the Papua New Guinea Government has approved the DSTP method with near offshore ocean slopes leading to a deep ocean basin with an absence of upwelling; conditions that satisfy industry criteria for the application of DSTP.

The Brucejack operation in Canada uses lacustrine deposition.

Tailings Management System

Where tailings are discharged into TSFs, risk is managed through completion of engineering designs in accordance with leading practice guidelines (e.g., ANCOLD 2019), safety assurance through independent review, and by following Newcrest’s internal risk and change management procedures.

Newcrest’s commitment to safe and responsible tailings facility operations is documented in the Tailings Governance Policy and required by Newcrest’s Tailings and Water Storage Standard.

These documents are aligned to the International Council on Mining and Metals (ICMM) Preventing Catastrophic Failure of Tailings Storage Facilities Position Statement and the Global Industry Standard on Tailings Management (GISTM).

Global Cooperation and disclosures

Newcrest is committed to public disclosure and transparency around publishing its tailings facility details in the Global Tailings Portal database allowing investors and stakeholders to review tailing facilities, the impact of climate change and the extreme weather events on dam stability.

 

global industry standard on tailings management (gistm)

Newcrest Mining statement on conformance of Newcrest tailings storage facilities with the Global 
Industry Standard on Tailings Management

Newcrest aspires to be a leader in tailings management with the ultimate goal of zero harm to 
people and the environment. 

As a member of the International Council of Mining and Metals (ICMM), Newcrest is committed to 
best practice tailings management and working towards continual conformance with the Global 
Industry Standard on Tailings Management (GISTM) through meaningful engagement as part of an 
ongoing effort focused on dam integrity and public safety.

The Standard is a significant step towards strengthening current practices in the mining industry to 
support safer and more responsible tailings facility management. 

We are proud to be part of the Standard’s development with a focus on implementing the Standard 
through our ICMM membership commitment. 

While acknowledging Newcrest will not fully conform with the Standard by 5 August 2023, Newcrest 
has fully disclosed the level of conformance by all TSFs with potential consequences of failure 
assessed as being ‘extreme’ or ‘very high’.

All other tailings facilities operated by Newcrest are due for conformance disclosure by 5 August 
2025. This includes the three current tailings facilities at our Cadia mine.

While working towards conformance, Newcrest’s focus has been on dam safety and integrity, in 
particular at Cadia where work is underway to reduce risks and recover from the 2018 slump in the 
Northern TSF.

We have updated internal management and governance systems including standards and guidelines 
to align with the GISTM and increase resources devoted to tailings safety through a dedicated 
project team so we can achieve conformance in the shortest time frame possible.

Newcrest has taken a cross functional, multidisciplinary approach to conformance based on the 
ICMM guidance documents and location-specific regulatory requirements. We are using 
consequence classifications based on permitted facility height or the best available data.

Implementation of the Standard has already resulted in transformative improvements across the 
global mining sector in tailings management, governance and monitoring. 

It has also elevated tailings management to the highest levels of company oversight and 
accountability, while promoting greater transparency and meaningful engagement with 
stakeholders. 

Newcrest’s site-specific conformance disclosures can be found below.

Newcrest’s site-specific conformance disclosures

Cadia NTSF Embankment slump

On 9 March 2018,  a localised slump event occurred on the Northern Tailings Storage Facility (NTSF) at Cadia. The slump event resulted in a release of tailings from NTSF with all tailings contained within the Southern Tailings Storage Facilities (STSF).

Newcrest accepted the findings of the independent review into the causal factors and root cause of the event and has made these publicly available at the link below. Following the report, investigations and reviews of all major water and tailings facilities across Newcrest were undertaken, with remediation projects identified and progressed.

Cadia NTSF Embankment Slump mechanisms

 
NEXT UP

Cadia NTSF Investigation Reporting

Forward Looking Statement

This webpage includes forward looking statements and forward looking information within the meaning of securities laws of applicable jurisdictions. Forward looking statements can generally be identified by the use of words such as “may”, “will”, “expect”, “intend”, “plan”, “estimate”, “anticipate”, “believe”, “continue”, “objectives”, “targets”, “outlook” and “guidance”, or other similar words and may include, without limitation, statements regarding estimated reserves and resources, certain plans, strategies, aspirations and objectives of management, anticipated production, study or construction dates, expected costs, cash flow or production outputs and anticipated productive lives of projects and mines. Newcrest continues to distinguish between outlook and guidance. Guidance statements relate to the current financial year. Outlook statements relate to years subsequent to the current financial year.

These forward looking statements involve known and unknown risks, uncertainties and other factors that may cause Newcrest’s actual results, performance and achievements or industry results to differ materially from any future results, performance or achievements, or industry results, expressed or implied by these forward-looking statements. Relevant factors may include, but are not limited to, changes in commodity prices, foreign exchange fluctuations and general economic conditions, increased costs and demand for production inputs, the speculative nature of exploration and project development, including the risks of obtaining necessary licences and permits and diminishing quantities or grades of reserves, political and social risks, changes to the regulatory framework within which Newcrest operates or may in the future operate, environmental conditions including extreme weather conditions, recruitment and retention of personnel, industrial relations issues and litigation. For further information as to the risks which may impact on Newcrest’s results and performance, please see the risk factors included in the Annual Information Form dated 13 October 2020 lodged with ASX and SEDAR.

Forward looking statements are based on Newcrest’s good faith assumptions as to the financial, market, regulatory and other relevant environments that will exist and affect Newcrest’s business and operations in the future. Newcrest does not give any assurance that the assumptions will prove to be correct. There may be other factors that could cause actual results or events not to be as anticipated, and many events are beyond the reasonable control of Newcrest. Readers are cautioned not to place undue reliance on forward looking statements, particularly in the current economic climate with the significant volatility, uncertainty and disruption caused by the COVID-19 pandemic. Forward looking statements in this document speak only at the date of issue. Except as required by applicable laws or regulations, Newcrest does not undertake any obligation to publicly update or revise any of the forward looking statements or to advise of any change in assumptions on which any such statement is based.