Tailings, Waste and Emissions

Mining activities – extracting, processing and refining – generate air emissions and waste including tailings (the rock slurry that remains after removing the desired minerals).

Reducing mine waste and improving chemical management through recovery and recycling throughout the mine lifecycle lowers risks and costs and supports our commitment to operate in a responsible, sustainable manner. We also recognize the potential catastrophic consequences should one of our tailings or other impoundments fail, and we are committed to continuous improvement and the safe management of those facilities and structures.

A set of global standards outlines our commitment and establishes minimum requirements to manage the risks posed by mineral and non-mineral waste, hazardous materials and emissions in a manner that protects the environment and human health; promotes beneficial post-mining land use; and reduces post-mining closure and reclamation liabilities.


After mined ore is reduced into sand-sized particles and mixed with water, the valuable minerals are removed and the remaining milled rock slurry – called tailings – flows to an engineered impoundment called a tailings storage facility (TSF).

In response to several high-profile tailings dam failures, the International Council on Mining and Metals (ICMM) developed a position statement that was published at the end of 2016 on Preventing Catastrophic Failure of Tailings Storage Facilities, which addresses six key areas of governance that members, including Newmont, agreed to implement.

To meet this commitment, we updated three standards – Tailings and Heap Leach Facility Management, Water Management, and Surface Ground Control – that govern the operation of all our TSFs. These standards explicitly include the ICMM governance framework and integrate cross-functional and regional feedback. In 2018, all operating sites reached full compliance with our updated standards.

Other governance improvements include:

  • Updates to guidance for the development of tailings management plans and requirements for the design and closure of tailings and heap leach facilities;
  • The addition of a catastrophic TSF failure to our top enterprise risk analysis and developing a globally consistent set of critical controls to reduce the risk;
  • A new training program to improve knowledge; and
  • The establishment of independent technical review boards (ITRB) at our five sites with TSFs deemed to be a high priority – Akyem and Ahafo in Ghana, Boddington and KCGM in Australia, and Merian in Suriname.

Each ITRB member is a respected global tailings and hydrology expert who has more than 30 years of experience and a key regional perspective. ITRB reviews are conducted annually, and final reports are added to our Integrated Management System (IMS) where site and regional teams track actions.

Our engineered TSFs and heap leach facilities (HLF) are designed to withstand extreme weather or seismic events. In addition to daily performance monitoring and inspections conducted by on-site staff, qualified independent senior geotechnical engineers inspect every TSF at least once a year. Emergency response procedures are tested periodically and, at a minimum, reviewed annually. Additional information about our approach to managing tailings – including a complete inventory of each operating and legacy facility – is included in a fact sheet available on our website.

Reports on TSF risk management are provided quarterly to the executive leadership team (ELT) and annually to the Board of Directors’ Safety and Sustainability Committee.

Waste rock

Each operation is required to manage waste rock and ore stockpiles in a manner that promotes beneficial post-mining land use and reduces closure and reclamation liabilities. Sites must also minimize the risk to surface and groundwater quality from acid rock drainage (ARD), which is generated when water comes into contact with certain minerals in the rock that are oxidized by exposure to air, precipitation and naturally occurring bacteria. In instances where prevention is not possible, we collect and treat ARD in a manner that protects human health and the environment.

Hazardous and non-hazardous materials

We minimize the use and amount generated of hazardous materials – inclusive of hydrocarbons and cyanide – by replacing hazardous chemicals with less hazardous products whenever possible. For example, we often use citrus-based solvents in our maintenance facilities instead of chlorinated ones.

Hydrocarbon wastes (e.g., used oil) are the largest portion of our hazardous waste stream, which also includes shop waste, such as grease and solvents, and laboratory chemicals. Our sites minimize the volume requiring disposal by recycling almost all waste oils and greases, either through third-party vendors or on-site processes, such as using waste oil for fuel in combustion processes or explosives.

We also make every effort to recycle or reuse non-hazardous waste. Through Full Potential – our global continuous improvement program – we have identified opportunities such as increasing the tire life on haul trucks, optimizing the use of reagents and other consumables, and identifying materials (e.g., HDPE pipes and valves) that could be recycled rather than thrown away.

Air emissions

Our material air emissions are sulfur and nitrogen oxides (SOx and NOx), particulate matter (PM) and mercury. SOx emissions are primarily generated at coal-fired power plants and during thermal processes that heat pyritic ore. NOx emissions are produced during combustion of fossil fuels, including diesel that powers generators and heavy equipment (e.g., haul trucks), and coal, natural gas and propane in stationary sources such as furnaces and power plants. All our diesel fuel suppliers must provide ultra-low sulfur diesel (ULSD), which contains 97 percent less sulfur than low-sulfur diesel and allows for the use of pollution-control devices that are more effective at reducing diesel emissions but can be damaged by sulfur. In our underground operations where diesel PM (DPM) is a health risk, we are retrofitting higher horsepower equipment to decrease DPM emissions. Our fugitive PM emissions are primarily dust from mining activities such as blasting, excavating and crushing ore. Our approach to managing emissions characterized as greenhouse gases (GHG) is detailed in the Energy and Climate Change section of this report.

All sites must comply with the local laws and regulations for source air emissions, fugitive dust emissions and ambient air quality. For those jurisdictions where laws are non-existent or incomplete, we apply the U.S. Environmental Protection Agency (EPA) national ambient air quality standards.


Our approach to responsibly manage mercury byproduct aligns with ICMM’s position statement. We do not use mercury to mine or extract gold. However, naturally occurring mineralized forms of mercury exist in ores at our KCGM (Australia), Carlin and Twin Creeks (Nevada), Yanacocha (Peru) and Merian (Suriname) operations, and ore processing can generate mercury compounds and gaseous elemental mercury.

We capture point-source mercury from air emissions using maximum achievable control technology (MACT) standards, and we continuously evaluate opportunities to reduce emissions.

We are committed to permanently removing mercury waste from circulation using long-term safe storage solutions. In the U.S., the Mercury Export Ban Act (MEBA) prohibits the export of elemental mercury, and the U.S. Department of Energy (DOE) oversees the long-term storage of elemental mercury. Until the DOE constructs a permanent facility and begins accepting mercury, we are safely storing mercury on site.

For the management of non-U.S. mercury, we continue to negotiate an agreement to transport and permanently retire elemental mercury currently stored at Yanacocha. Commercial disposal agreements for KCGM and Merian are planned for the future.

Performance measurement

We annually report our air emissions through the U.S. EPA’s Toxic Release Inventory (TRI) program and Australia’s National Pollutant Inventory.

As a member of the International Council on Mining and Metals (ICMM), we participate in the organization’s Tailings Aspirational Goal (TAG) working group that is working to identify innovative technologies and practices that can minimize or replace conventional wet storage facilities (such as TSFs) over the next 10 to 15 years. We also collaborate with several industry-led consortiums – including partnerships with the University of Western Australia, Canadian Mining Association, China Engineering Machinery Corporation, Commonwealth Scientific and Industrial Research Organization, and Mine Environmental Neutral Drainage program – to improve TSF management practices and reduce the risk of potential failures.

Newmont is an active member of the International Network for Acid Prevention (INAP), an industry-led group that promotes best practices in handling potentially acid-generating materials such as waste rock and tailings. We also participate in an ICMM-led working group engaging on the United Nations Minamata Convention on mercury – a global treaty to protect human health and the environment from the adverse effects of mercury – to develop regulations for the Convention’s signatories.


Newmont generated 300 million tonnes of waste rock and 112 million tonnes of tailings in 2018 – a year-over-year decrease of 13 percent and increase of 1 percent, respectively, compared to an overall decrease in annual consolidated gold production from continuing operations of 3 percent. Approximately 36 percent of our total waste rock is characterized as potentially acid-generating, up from 26 percent in 2017 due to less waste rock combined with an increase in mining in areas that contain a higher amount of potentially acid-generating rock.


Year 2014 2015 2016 2017 2018
Total waste rock generated 406.6 340.1 335.9 346 299.7
Total tailings 146.1 135.9 96.8 110.9 112.1


Year 2014 2015 2016 2017 2018
Total non-hazardous waste 49.5 46.0 34.8 38.1 66.9
Total hazardous waste 38.9 40.0 12.0 12.2 18.4
12018 non-hazardous recycled wastes omit our Long Canyon site.
2 Hazardous recycled waste data for 2018 includes reported estimates for on-site and assumptions for off-site that are based on 2017 data.

We generated a total of 18,369 tonnes of hazardous and 66,925 tonnes of non-hazardous waste at our operations in 2018. An estimated 45,960 tonnes of our non-hazardous waste (69 percent) was recycled.

Around 9,167 tonnes (50 percent) of our hazardous waste was treated, incinerated and/or disposed of on site; 4,564 tonnes (25 percent) was treated, incinerated and/or disposed of off site by qualified service providers; and 4,637 tonnes (25 percent) was recycled.

Our global elemental mercury production was 26.9 tonnes, a 1.1 percent increase from 2017, reflecting the variable mercury content in our ore.


Year Mercury production
2014 20.9
2015 12.5
2016 19
2017 26.6
2018 26.9


Year 2014 2015 2016 2017 2018
SOx (SO2) 168.2 34.0 0.1 1.5 0.1
NOx (NO2) 6.4 7.1 5.5 6.9 6.19
PM10 19.0 19.8 17.3 16.7 16.57
Carbon monoxide (CO) 2.3 2.6 3.4 3.0 2.78
Note: Our Australia sites operated by Newmont report air emissions on a fiscal year basis (July 1 to June 30); however, Kalgoorlie Consolidated Gold Mines (KCGM) reports its air emissions on a calendar year basis (January 1 to December 31).


Year 2014 2015 2016 2017 2018
Mercury (Hg) 4.0 2.4 0.4 0.7 0.6
Arsenic (As) 4.6 3.9 3.4 3.0 2.8
Lead (Pb) 0.5 0.6 0.6 0.6 0.6
Selenium (Se) 4.1 0.1 0.1 0.1 0.1
Note: Our Australia sites operated by Newmont report air emissions on a fiscal year basis (July 1 to June 30); however, Kalgoorlie Consolidated Gold Mines (KCGM) reports its air emissions on a calendar year basis (January 1 to December 31). Mercury emissions omit Merian, Suriname data.

Variations in ore composition also impact air emissions. Our sulfur dioxide and mercury emissions have significantly decreased since 2014 after decommissioning KCGM’s Gidji roaster, which previously accounted for around 99 percent and 95 percent of Newmont’s total annual sulfur dioxide and mercury emissions, respectively.

Our standards detail the minimum requirements for managing our facilities, waste and emissions, and during the year we further defined these requirements in updated standards for waste, waste rock and ore stockpile facilities, hazardous materials and air emissions.

Ensuring full compliance with the ICMM Tailings Governance Framework, which minimizes the risk of catastrophic tailings dam failures, was a significant area of work during the year. Among the key activities to achieve this milestone:

    • We completed gap assessments against our updated Tailings Storage and Heap Leach Facility Management Standard and developed action plans to address areas of non-conformance. Cross-functional teams identified critical controls for TSFs and site-level performance criteria. Teams also developed a schedule and implementation plan for audits, reviews and controls related to TSFs; clarified the roles and responsibilities of each function involved in the operation and management of TSFs; and developed a change management process that defined what changes would result in required updates to planning documents or resources and what level of approval was required. More information about this work is included in the featured case study.
    • The ITRBs at our five high-priority TSFs conducted site visits and completed reviews. All facilities were found to be stable and in compliance with Newmont’s and other international standards. The reports found that Newmont applies best practices and employs proper governance to reduce risks and liabilities. They also highlighted that the TSF critical controls support continuous improvement and that the process is driving desired behaviors across the organization. In 2019, we plan to expand the ITRBs to other projects where technical, environmental, social or political risks warrant the need for increased governance.
    • To improve the competency of the operators and engineers responsible for tailings and water management at the sites, we launched a comprehensive training program that emphasizes best practices for designing, operating and closing TSFs. In 2018, approximately 30 engineers and operators were trained in the Africa region. Additional training is scheduled for 2019 at our sites in Africa and South America.

In early 2019, we updated our publicly available tailings fact sheet to disclose additional details about how we manage tailings and to publish a full inventory of our tailings facilities.

Newmont representatives participated in ICMM’s Tailings Aspirational Goal (TAG) working group meetings in which a consolidated road map was developed for three parallel tracks of activities: investigate and identify alternative methods of mineral recovery; develop technologies to remove moisture from tailings; and strengthen critical controls for the design, operation and closure of TSFs. For each track, the group identified activities, milestones and outcomes for the next three years (2019 through 2021). Activities in 2019 will largely focus on understanding the current state, identifying opportunities and challenges, and engaging equipment manufacturers.

To safely transport and permanently retire all liquid mercury byproduct from our non-U.S. based operations, we are negotiating a disposal agreement with Batrec, a Swiss-based subsidiary of the German company SARPI-VEOLIA, for Batrec to transport and permanently retire elemental mercury currently stored at Yanacocha beginning in 2019. The retirement of mercury from KCGM and Merian is planned for beyond 2019. Batrec proposes to convert the liquid to a mineral sulfide and dispose of the solid material in an engineered underground salt mine in Germany.

We held two internal workshops to discuss opportunities to reduce mine waste and improve chemical management through recovery, recycling or repurposing. Initial efforts will focus on integrating circular economy concepts into our Full Potential program. Identification of projects to reduce and reuse waste will be ongoing.

Efforts at our operations to address our risks and improve our tailings, waste and emissions management approach include the following:

      • Developed plan for TSF expansion: At our Ahafo operation in Ghana, we developed a road map and stakeholder engagement process related to the site’s TSF expansion project, which involved the resettlement of more than 89 households. We held several public hearings throughout the year and worked extensively with the Ghana Environmental Protection Agency to reach agreement on the final design specification for the site’s TSF expansion project. The EPA approved construction of the TSF expansion project in October while the permitting process continued.
      • Received approval for TSF expansion project: Ghana’s Inspectorate Division of the Minerals Commission approved the Akyem operation’s TSF expansion project, and Newmont received the permit in April.
      • Sponsored research on tailings: We are sponsoring a three-year program with the University of Western Australia to develop a better methodology to interpret tailings storage performance. The research, which is focused on our Boddington and KCGM operations, included testing of lab materials in 2018. Larger scale testing and a pilot are planned for 2019.
      • Commenced impact assessment: At our Twin Creeks operation in Nevada, we commenced an environmental impact assessment (EIA) for its Sage tailings expansion project. The EIA is expected to be finalized in mid-2019.
      • Evaluated technologies to reduce waste: Our global digital strategy includes two initiatives designed to reduce waste through the application of technologies. The Smart Mine initiative improves decision making related to the mining and processing of ore and includes using optimizer software that maximizes ore recovery and produces less waste. In 2018, we implemented the software at our Long Canyon operation in Nevada and Boddington mine in Australia. Another initiative – Connected Worker – will use technology to keep track of personnel and will integrate work tools, such as time and attendance tracking. The initiative, which we began deploying in our North America and Australia regions in 2018 and will be expanded to our Africa and South America regions in 2019, is expected to significantly reduce the amount of paper used for employee-related activities such as attendance tracking, scheduling and time sheets.

Click here for full data tables

View our featured Case Study