Air quality

Our mitigation measures aim to reduce atmospheric emissions from our gold plants and operations. Primary atmospheric emissions from our gold plants are sulphur oxides (Sox), nitrous oxides (NOx) and particulate matter (PM) as well as dust fallout from our operations (including TSFs). We manage these air pollutants with an environmental strategy that aims to protect our host communities and the environment.

Our approach

We measure our primary atmospheric emissions against the conditions of our licences for each plant, and our formal complaints system addresses public concerns with immediate investigation and corrective action. Our gold plants meet legislated thresholds with occasional PM exceedances. We address these exceedances by ensuring we use high-quality carbon as part of our multidisciplinary risk management process, which includes GHG emission reduction programmes. We identify, monitor and mitigate all emissions at company and asset levels.

Our South African operations apply the American Standard for Testing and Materials method (D1739) in dust fallout monitoring and mitigation at our operations and TSFs across the group. These operations also apply to the National Environmental Management: Air Quality Act’s national dust control regulations in collecting and analysing dust fallout.

Monitoring often indicates other fugitive dust sources with tailings fallout. We record exceedances as non-compliance and implement remedial measures when exceedances are due to our mining activities. Other sources include algal growth in wet seasons as well as soil and other organics that may contaminate samples.

At our Hidden Valley operation, and Wafi-Golpu and Eva Copper Projects, we conduct monitoring programmes commensurate with our activities and informed by compliance requirements. The location of these assets affords some separation from sensitive receptors. For the Wafi-Golpu and Eva Copper assets, the respective environment permit under Papua New Guinea regulation, and environmental authority under Queensland regulation, stipulate further PM and dust deposition requirements that will come into effect when mining activities commence.

South Africa

In FY23, the regulator approved all required annual national atmospheric emission reports submitted by our operations. Our Mponeng gold plant also received recognition from the Gauteng Department of Agriculture, Rural Development and Environment for its NOx reduction programme.

While there were no reportable exceedances, we continued implementing our prevention interventions which included chemical suppression, netting, grassing, trees, irrigation and controlled maintenance in windy seasons. We continued to address concerns despite costly equipment theft and vandalism:

• Kusasalethu reduced the dust fallout from its TSF and improved air quality in the West Wits area with irrigation and indigenous woodland land-based initiatives as part of land rehabilitation
• Mine Waste Solutions (including the Kareer and TSF extension), Moab Khotsong and Kalgold addressed PM and dust fallout exceedances through the use of better quality activated carbon (for point source emissions) as well as irrigation, chemical suppression, dust netting and vegetation initiatives being employed (for dust fallout exceedances)
• Mponeng improved NOx emission intensity from 35% to 25% by repairing an extractor fan in the smelter house
• Doornkop’s TSF revegetation project and dust reduction on gravel haul roads were delayed by community unrest. Work is scheduled to start soon.
• Free State operations installed or moved 25 000m of netting (wind barriers) and planted vegetation on top of TSFs to reduce dust Emissions with its dust management plan
• Noligwa gold plant reduced PM emissions with higher-quality activated carbon – we are extending this practice to Mine Waste Solutions.

Papua New Guinea

At Hidden Valley Mine, dust emissions at our monitoring sites remained below permitted compliance limits and in line with historical trends. Average dust deposition levels were highest in October 2022 due to drier weather conditions experienced in the area at this time

FY23 PERFORMANCE AND FOCUS AREAS

Improvements in Particulate Matter (PM) emissions will continue to receive priority at our gold plants, through better operational control, the use of improved quality activated carbon and changes to more efficient abatement equipment where necessary.

• In South Africa, we will continue rolling out mitigating measures (installing barriers such as artificial netting or trees, dust suppressants and rehabilitative vegetation). The success of these measures depends on communities’ cooperation in preventing theft and vandalism of equipment, including R6 million (US$0.3 million) in irrigation to be installed at Doornkop in the coming year.  
• In Papua New Guinea, our focus remains on implementing our monitoring programmes, commensurate with the project Phase and site activities informed by compliance requirements.
• In Australia, our focus is on establishing our baseline monitoring programme at Eva Copper.

We will also review our dust monitoring programme to ensure it is appropriate. This will include reducing PM exceedances at operations by improving process controls, upgrading equipment where necessary and implementing preventive maintenance programmes.

Future Focus

Improvements in PM emissions will continue to receive priority at our gold plants, through better operational control, the use of improved quality activated carbon and changes to more efficient abatement equipment where necessary.

In South Africa, we will continue with the roll out of mitigating measures, including a R6 million (US$0.3 million) irrigation system that is to be installed at Doornkop.

A planned review of our dust monitoring programme is aimed at ensuring it is appropriate and that it will help to reduce PM exceedances at operations.

In Papua New Guinea, our focus remains on implementing monitoring programmes, commensurate with project phase, site activities and informed by compliance requirements.

In Australia, we will focus on establishing our baseline monitoring programme at the Eva Copper project.