55 Mining Gold for a Better Future: 2020 Sustainability Report Page 1 of 198 We’re mining gold for a better future Maleiya is a Construction Cost Controller at our Haile Gold Mine in the United States. OceanaGold is a multinational gold producer committed to the highest standards of technical, environmental and social performance. For 30 years we have contributed to excellence in our industry by delivering sustainable environmental and social outcomes for our communities, and strong returns for our shareholders. Today, we are delivering one of the best organic growth profiles in the industry and our ongoing operations are contributing to sustainable economic growth, providing certainty for community, business and government. We have four mine assets including the Macraes and Waihi operations in New Zealand; Haile Gold Mine in the United States of America (United States); and Didipio Mine in the Philippines. At each of our operations we contribute to economic growth, employment and skills development and community and environmental partnerships. Our purpose is mining gold for a better future. The gold, copper and silver we produce help power the global economy, hold important historic and cultural significance and are essential to the renewable energy and transport sectors, life-saving medical devices and the technology that connects communities around the world. Our vision is to be a resilient and dynamic gold miner, trusted to deliver enduring value through innovation, performance and sustainable growth. That vision is brought to life by our company values – respect, one team, contribute and knowledge – that put the safety and wellbeing of our people, communities and environment at the forefront of every decision we make. Mining Gold for a Better Future: 2020 Sustainability Report Page 2 of 198 Mining Gold for a Better Future: 2020 Sustainability Report Page 3 of 198 A message from our Chair and CEO Our purpose is mining gold for a better future and it is our pleasure to provide OceanaGold’s 2020 Sustainability Report. The gold, copper and silver we produce help power the global economy, hold important historic and cultural significance and are essential to the renewable energy and transport sectors, life- saving medical devices and the technology that connects communities around the world. Our commitment to responsible mining is vital to achieving our purpose and our vision to be a resilient and dynamic gold miner, trusted to deliver enduring value through innovation, performance and sustainable growth. 2020 was a year like no other. Across the company we demonstrated our values of respect, one team, contribute and knowledge – a credit to our employees and families, contractors, suppliers, communities and other stakeholders who came together, supported each other and the company through a challenging and uncertain year. The COVID-19 pandemic changed the way we live and work. For some of us, life is returning to a more normal state, but the pandemic is still impacting communities globally. At all our workplaces, our management of the pandemic has required a fluid and adaptable approach that reflects the local reality. Following the World Health Organization’s declaration of a global pandemic, we adopted common (but jurisdictionally appropriate) intervention and control strategies to protect the health and wellbeing of our workforce and minimise the potential for our workplaces to become a source for transmission of the virus. While we remain focused on our prevention, preparedness and response strategies, we also continue supporting our workforce and the communities in which we live and work. Our Didipio Mine in the Philippines remained in a state of operational readiness, with the normal operations of the mine suspended throughout the 2020 calendar year. Very sadly, and over a year since we suspended mining, we had to implement two rounds of employee redundancies, directly impacting 584 employees, their families and the cooperatives, communities and suppliers we work with. We are grateful for the continued overwhelming support we receive from employees and the host and adjacent communities of the Didipio Mine, and for the positive signs we have seen from the government. We remain focused on renewing our Financial or Technical Assistance Agreement (FTAA) and will continue our engagement with the Philippine Government. As a contractor of the Government and a responsible multinational miner, we are ready and waiting to restart the Didipio Mine quickly and safely, re-employ our workforce and to contribute to the Philippines’ post-COVID-19 recovery. While 2020 had its challenges, we remained driven to deliver our responsible mining commitments. We made strides towards full compliance with the World Gold Council’s Responsible Gold Mining Principles (RGMPs), receiving independent external assurance of our progress towards RGMP compliance by September 2022. Mining Gold for a Better Future: 2020 Sustainability Report Page 4 of 198 We led our peer group and took climate action, releasing an updated Statement of Position on Climate Change, Energy Use and Greenhouse Gas and setting the goal to achieve net zero GHG emissions by 2050. As part of our journey to understand our greenhouse gas emissions footprint, we commenced our first assessment of Scope 3 emissions and in 2021 we will set interim 2030 GHG emissions targets. Over US$4 million was invested in social programs, donations, in-kind support and community infrastructure. We continued to prioritise local procurement and benefits, investing over US$99 million in local procurement, and US$135.8 million in employee wages and benefits. The company also strengthened its corporate governance, ethics and compliance. We commenced a responsible supply chain program of work, including scoping a governance framework and mapping our supply chain in preparation for supply chain risk assessments in 2021. We also commenced the development of a Responsible Supply Chain Framework designed to address a range of third-party risks. We reissued corporate governance documents that reflect additional requirements to meet globally benchmarked performance expectations. These included a new Speak Up Policy (formerly known as the Whistleblower Policy); an updated External Affairs and Social Performance Manual with additional human rights and sponsorship performance requirements; and in 2021, an enhanced Statement of Position on Tailings Storage Facility (TSF) Management aligned to the Global Industry Standard on Tailings Management (GISTM). Our approach to Human Rights and Modern Slavery was bolstered during 2020. Having undertaken a Human Rights Impact Assessment (HRIA) at our Didipio Mine in 2019, we completed a HRIA at our Haile Gold Mine in 2020 and commenced HRIAs at the Waihi and Macraes operations in New Zealand. We will publish a report outlining the results of our HRIAs and our work program to continue improving our performance in December 2021. In 2018, Australia passed the Modern Slavery Act 2018, requiring entities based, or operating, in Australia, which have an annual consolidated revenue of more than $100 million, to report annually on the risks of modern slavery in their operations and supply chains, and actions to address those risks. We have released our first Modern Slavery Statement, detailing our assessment of our potential modern slavery risks, the work we delivered in 2020, how we measure effectiveness and our planned actions for 2021. In 2020, we updated our corporate strategy to support company-wide performance, organic growth and investment goals that are underpinned by our purpose, vision and values. Our strategy is built on five key pillars: investment, growth, management, capability and delivery. Under the strategy we commenced five execution plans: delivering organic growth in New Zealand; realising the Haile Gold Mine’s full potential; connecting the right talent to achieve growth and performance targets; planning, accountability and resourcing for delivery; and delivering sustainability and environmental and social governance (ESG) outcomes. Mining Gold for a Better Future: 2020 Sustainability Report Page 5 of 198 Our focus shifted from expansion to targeted resource development and exploration opportunities in existing gold deposits within our current mining footprint and we undertook extensive technical studies to investigate project development potential. We also continued to look at ways to automate our business to improve performance, safety and reduce our social and environmental impacts. We cemented our purpose, vision and values – known as The OceanaGold Way. Following consultation with our workforce, we identified the elements of our culture that were most meaningful to our people and refreshed our purpose, vision and values, giving them greater clarity and connection. Our approach to health and wellbeing was enhanced, delivering a significant update of our Occupational Exposure Management Guideline. This in turn generated a review of occupational hygiene exposure management at each of our operations. We developed a framework to measure the success of initiatives undertaken to support mental and physical health. In New Zealand, our Macraes Operation won the Minerals Sector Health and Safety award for its Healthy Employees Make Safer Employees Program. The program is being delivered over five years and supports employees to make proactive health choices. It was developed following studies including research into fatigue/sleep, Vitamin D levels, hydration, physical