Environment and Responsible Operations

Perseus is committed to minimising the impact of our activities on the natural environment through the integration of good environmental practices to all areas of our business.


Our operations align with the international Standard ISO 14001:2015 – Environmental Management Systems as well as the environmental regulations of our host countries. Potential impacts on water, air quality, soil, visual aesthetics and biodiversity were assessed during the Environmental and Social Impact Assessment process conducted for all operations during their design phase, in line with international standards and in consultation with our stakeholders. Management plans are implemented during construction and operation to manage risks, complimented by risks assessments conducted in line with our Risk Management Framework. Robust environmental monitoring programs are in place to identify prevent or mitigate impacts.


We recognise that the management of tailings – the residual, slurry-like material left after gold is extracted from ore and stored in a Tailing Storage Facility (TSF) – is of concern to our stakeholders.

We are committed to preventing loss of containment and other environmental and social impacts from our TSFs across their lifespan, in line with widely supported international good practice, governance and risk management.

From concept stage, TSFs location and design are integrated into our mine development and operational planning, including engaging with local communities, collecting baseline information to inform decisions throughout the TSF life, and impact assessments. The location, selection and design of our TSFs are in line with the Australian National Committee On Large Dams (ANCOLD) standards and local regulations. Management measures developed from these assessments are integrated into our licence conditions, site operational plans and HSEC plans. All TSFs include leak and stability detection systems.

Independent experts design all TSF lifts and expansions, with construction monitored closely through quality assurance and control.
During operation, we carry out monitoring, surveillance and auditing to check the facility functions as intended and change facility management as required. We maintain operating discipline of our TSFs in accordance with their ANCOLD consequence category and design standards, and country-specific regulatory requirements (where applicable). Emergency Preparedness and Response plans are in place at each operation, including for tailings dam failures in line with the TSF risk profile. Routine training and drills on our Emergency Plans include desktop exercises and simulations.

In FY22, we updated all our tailings dam break assessments to align with updated ANCOLD Standards and the Global Industry Standard on Tailings Management (GISTM) and completed gap analysis against the GISTM. We completed independent review and update of our approach to closure cost estimation. Furthering a record of success that has seen no failure occur in the life of any of our tailings facilities, in FY22, we had no tailings dam failures or loss of containment events.

We aim to be transparent in disclosures related to our TSF management. A detailed directory of TSFs, including location, raising methods, heights, volumes, risk ratings and other technical details can be found in the Investors and Media Reports section of the website.

Case Study: Yaouré Tailings Dam Raise

In FY22, we prepared for and successfully completed the first raise of the Tailing Storage Facility (TSF) at Yaouré. The lift increased the
capacity of the TSF by lifting the embankment by 3.2m from 282.5mRL to 285.7mRL, providing sufficient tailings storage for a further 12 months
of continued operations (to mid-2023).

The Yaouré TSF is located in the Bandama River catchment, five kilometres upstream of the Bandama River, downstream of Lake Kossou. The river and lake are rich in biodiversity, supporting globally threatened and vulnerable IUCN Red Listed mammal, bird, fish, reptile, amphibian and tree species. Downstream of the TSF is the village of Kouakougnanou and a powerline critical for hydroelectric power supply in the region. The river and lake are important for our local communities and are used for drinking, sanitation and irrigation purposes.

Given the TSF location, it was critical to ensure that the lift was conducted to the highest possible standard to manage social and environmental risks. This included:

  • Design by an industry leading independent expert (Knight Pièsold), complying with ANCOLD and new GISTM guidelines for safe design and operation of tailings dams;
  • Ensuring the design adhered to embankment stability requirements and incorporated calibrated modelling for water management and tailings consolidation. This included building an additional decant tower as part of the TSF raise, allowing water to be efficiently withdrawn from the tailings facility and continually recycled back through the processing plant;
  • Risk assessments for all elements of construction, design and assessment of the facility, based on the ANCOLD and GISTM guidelines; and
  • Full lining the TSF with a HDPE geo-membrane liner (overlying a low permeability compacted soil liner) to reduce seepage from the TSF. A textured HDPE liner was installed on the embankment upstream faces for safety reasons.

With these measures, we have exceeded the safety standards of local and international governing bodies.

As part of the construction process, the underlying fundamentals for Quality Assurance and Quality Control (QA/QC) were maintained. This was achieved through:

    • Independent QA/QC on all material placed by Knight Pièsold engineers present on site throughout construction. This was reported on a daily, weekly, monthly and quarterly basis. Laboratory and field testing was completed by an independent laboratory managed by Knight Pièsold;
    • Periodical reviews of all QA/QC data by the Knight Pièsold Design Manager to ensure integrity and adherence to design compliance;
    • Each layer of fill placed was approved by the Knight Pièsold site engineer;
    • The geomembrane was installed and tested in accordance with the manufacturer’s requirements and the Technical Specification, to ensure that all welds were completed to the required standards. A detailed walkover inspection was completed to ensure the liner area was free of defects; and
    • Adherence to the Operating Manual, which was assessed during the Annual Audit by the Engineer of Record (Knight Pièsold).

The Yaouré TSF design includes a full basin liner, internal drains to improve stored tailings density, a leakage collection and recovery system and a decant system design to optimise water recycling. These measures all act to mitigate any seepage into the environment. Perseus is proud to have built a worldclass facility that meets international standards, contributing to a cleaner, safer and more sustainable mining industry.

Waste Management and Hazardous Materials

Mining and processing ore for gold production requires the use of hazardous materials and generates non-hazardous and hazardous waste. We are committed to preventing impacts to human health and soil or water contamination from hazardous materials and waste.

Hazardous materials we use at our operations include lime, flocculants, caustic soda, hydrochloric acid, explosives, and cyanide. We proactively manage and monitor all cyanide transport, handling and storage processes, in line with the International Cyanide Management Code (ICMC). Our Operational Emergency Preparedness and Response Plans enable us to prepare for site-specific chemical or hazardous material or waste releases. Plans include regular training and drills to maintain our capability to respond.

Waste rock and overburden is our largest waste stream by volume. We deposit it onsite on appropriately engineered waste rock dumps or use it to backfill pits. We manage waste rock that is potentially acid generating (PAG) to prevent Acid Rock Drainage (ARD).

Tailings are our largest hazardous waste stream by volume, which are disposed to our TSFs.

Our most significant streams of non-hazardous waste include metals, cardboard, glass, plastic and aluminium. General household waste and organic wastes is disposed of via onsite landfill. Items such as unused food, scrap metal, plastic bottles and wood may be donated.

We commit to implementing effective systems to address the health, safety and environment risks of transporting, storing, handling and disposing waste and hazardous materials. Sustainable waste management is achieved through established reduction, re-use and recycling as appropriate and suitable waste disposal strategies.

Dust, Noise, Blast and Vibration

We seek to avoid or mitigate impacts on our workers, local communities and the environment arising from noise, dust, blasting and vibration associated with our operations.

All our operations monitor noise, dust and blast-induced overpressure and vibration to ensure we meet legal requirements, occupational health and safety standards and local community expectations. We also track and monitor any grievances associated with noise, dust, vibration and building damage.

We monitor employee and contractor exposure to dust, noise and vibration, and provide all personal protective equipment, including hearing protection, dust masks and other breathing apparatus, where exposures may be above safe occupational exposure limits.

All grievances raised by stakeholders relating to dust, noise, blast and vibration are investigated, and corrective actions taken as appropriate.

Biodiversity & Land

We recognise the importance of biodiversity conservation, the need for properly designated and managed systems of protected areas, and integrated land use planning, and aim to protect ecosystems and minimise or avoid biodiversity impacts and land disturbance. We will not explore or mine in World Heritage Areas and respect legally-designated protected areas.

Key biodiversity risks at our operations include land clearing, habitat loss/fragmentation and fauna disturbances due to light, noise and vehicle movements. We may also contribute to indirect impacts, include water quality and availability for ecosystems, soil degradation, bushfire, the introduction of weeds, feral animals and invasive pests, and human in-migration resulting in habitat loss. Our Yaouré and Sissingué operations are located close to river systems and IUCN Red List species are present adjacent to each of our operational areas.

We manage biodiversity risk at our operations by applying an established mitigation hierarchy (avoid, mitigate, rehabilitate and, where appropriate, apply compensatory measures) to any potential or residual adverse impacts on freshwater or terrestrial ecosystems.

Case Study: Progressive Rehabilitation & On-Site Nursery At Edikan

Progressive rehabilitation is being undertaken at our Edikan site in Ghana under the direction of our HSE Department. Edikan propagates its own seedlings in an on-site nursery, which is staffed by four personnel from the local villages. In December 2020 the nursery contained approximately 44,000 seedlings across 32 different species, with 60% of the species endemic to Ghana and the other 40% found in Ghana, but not native to Ghana. To date, we have rehabilitated 14% of the cleared land at Edikan.


Closure planning is integrated into the entire life cycle of our operated assets, from design through operation to closure and beyond.

While we manage the associated financial, environmental and social risks, our aim is to leave a positive legacy and optimise closure outcomes in consultation with local communities and other stakeholders.

During design, we develop Closure Plans for each operation, which include the approach to shaping landforms, rehabilitating vegetation, removing infrastructure, as well as re-purposing and social closure programs such as livelihood development. The plans are also used to calculate our closure provisions and the bank guarantees held by governments for each of our operations, which are reviewed annually.

During operation, we back-fill pits as much as possible, and progressively rehabilitate as areas become available, supported by onsite nurseries staffed by local community members. We also seek opportunities to partner with our communities and governments to identify post-closure land uses that generate enduring environmental, social and economic value, particularly self-sustaining social programs.

Case Study: Edikan

Progressive rehabilitation is being undertaken at our Edikan site in Ghana under the direction of our HSE Department. Edikan propagates its own seedlings in an on-site nursery, which is staffed by four personnel from the local villages. In June 2019 the Nursery contained approximately 52,500 seedlings across 32 different species, with 60% of the species endemic to Ghana and the other 40% found in Ghana, but not native to Ghana. To date, Ghana has rehabilitated 255ha back to natural with another 70ha rehabilitated to help control erosion.

Water Stewardship

We recognise access to safe, clean water as a basic human right and central to maintaining healthy ecosystems, community livelihoods and quality of life, and to the sustainability of our business – we cannot operate without it.

We aim to be responsible stewards of water, responsibly planning and managing water resources and risks relating to water availability, usage, consumption and quality. While we must ensure secure supplies of suitable quality water for our operations, we must also ensure clean water is available for our communities, and the environments and catchments in which we operate. We also seek to avoid any negative impacts on surface and ground water quality in our land areas, and work with our communities to improve and safeguard their access to safe drinking water.

We maintain water balance information at each of our operations, seek to maximise water use efficiency and recycling, and ensure our activities do not contaminate shared water resources.

As a key operational control, we monitor the quality of abstraction sources and discharges against reference locations outside our operations, and international and local guidelines. Water is regularly tested for contaminants associated with our activities, as well as physical and chemical characteristics such as pH, suspended solids, and nutrients.

Case Study: Sissingué Water management

We are deeply committed to Environmental Stewardship, and our responsibilities to manage the impact of our operations on water, land and other natural resources. Water quality monitoring is a critical control across all our operations – it enables us to protect our shared water resources, the health of our people and communities, as well as the stability of our operations. Robust water quality monitoring supports our pledge to be responsible stewards of water and meet SDG 6 (Clean Water and Sanitation).

Perseus monitors the quality of surface and groundwater across our sites to ensure it is suitable for our operational and domestic purposes, and to certify that the water we discharge to shared water resources is safe for our communities. We also monitor the quality of the ground and surface water outside our operational boundaries, upstream and downstream, so contaminants are not unknowingly released from our operations. We record the baseline water conditions prior to construction of our projects, as a reference point to identify impacts over time.

Monitoring parameters include physical properties, such as temperature, acidity and suspended solids; chemical properties and nutrients, heavy metals, chemical compounds such as cyanide, and microbiological parameters.

Our Sissingué operation is located in the Bagoé river catchment that forms the natural border between Côte d’Ivoire and Mali. The Bagoé River flows east towards the Baoulé River to form the Bani River, one of the main tributaries of the Niger River, the third-longest river in Africa.

We conduct monthly water quality sampling both upstream and downstream of the Bagoé river and in its tributaries, and across the operational area, including at the waste rock areas, ore storage areas, around the TSF, at the fuel and hazardous materials areas, the sewage treatment plant, pit sumps and settlement ponds. Physical parameters are measured on site, and samples of water from each location are also sent to the Biotitiale Laboratory in Abidjan for all other parameters. Duplicates of each sample are sent to SGS Laboratories in The Netherlands for quality assurance.

The results are assessed by comparison to local and international water quality guidelines. If there are results outside guideline limits, a repeat sample is taken to confirm the initial results.

The results of the analysis are compiled into a report each month with conclusions on indications of water contamination or other impacts. Adaptive management measures are implemented or further investigation is conducted if required.

The program is reviewed annually so it remains aligned to the risk profile of the activities as the operation evolves and is independently audited every three years.

Climate Change

We acknowledge climate change presents an emerging and increasing risk that will impact our organisation, our stakeholders and the communities that host our operations. As an organisation, we are committed to understanding and managing the potential implications of climate change on our business and our stakeholders.

We have assessed the risks and opportunities to Perseus from climate change and selected the Taskforce on Climate-related Financial Disclosures (TCFD) as an appropriate internationally recognised framework to disclose our climate-related risks, and our strategy to manage them.

Strategy and Risk Management

While climate change is a key consideration and focus for many of our stakeholders, its specific impact on our business under short- and medium-term operational conditions is lower than other business risks, such as health and safety, tailings management, and communities and government relations.

Nonetheless, we recognise that our business faces potential for both physical and transition risks from climate change.

Physical risks include impacts to our operations from extreme heat, flooding, drought and storms, supply chain disruption and increases to the cost of closure.

Transition risks include climate and energy policy and legal changes in West Africa, the cost of transition to new technologies, changes in supply and demand for gold and the cost of inputs, and potential reputational impact from increasing stakeholder scrutiny of our role in the changing climate, and our impact on surrounding communities.

We believe our current asset base has relatively low exposure to physical risks, due to our operations’ short life (relative to climate change driven impact) of five to eight years. For this reason, our immediate focus will remain on other critical sustainability issues and opportunities such as community engagement, health, safety and wellbeing and economic development.

A price on carbon is a possible transition risk. In West Africa, Côte d’Ivoire and Senegal are exploring carbon pricing as part of policy options to reach objectives of the Nationally Determined Contributions (NDC). and are consulting with stakeholders to assess initial policy design options. We will continue to monitor and assess the opportunities and risks associated with the pricing of carbon.
Gold’s carbon footprint is relatively small compared to other mined resources, driven in part by the small amount of gold produced globally each year (less than 3000 tonnes) and its relatively low emission intensity levels ‘per US$ value’ (refer to the chart below). Gold also has the potential to play an important role in emerging technologies that will help facilitate the transition to a low carbon economy, which may give us potential opportunities to reduce our future carbon impact.

Metrics and Targets

The most significant environmental impacts of Perseus’s business are the emissions associated with our operations. We report on these metrics on an annual basis and work to maximise our energy efficiency and reduce our emissions.

We are currently exploring options to lower emissions in our operations and considering costs when assessing viable efficiency initiatives. We monitor usage and efficiency metrics for water, energy and emissions. These indicators are used as the basis for identification of efficiency initiatives, where assessed as viable.


We monitor usage and efficiency metrics for water, energy and emissions, and are exploring options to lower emissions in our operations, and a range of efficiency initiatives.

While our energy consumption mix includes hydropower and natural gas, our largest source of energy is diesel. Accordingly, our Scope 1 and 2 emissions from diesel-generated and purchased electricity represent our primary emission challenge.




There is potential to adopt greater levels of renewable and lower-emission energy, but West Africa presents a challenging environment for renewables, including land and infrastructure security and investment timeframes. We will consider renewable energy in the power assessments for all future new developments.

While emissions intensity varies with gold grades and mining methods, our emissions intensity of 0.55 tonnes of CO2-e per ounce of gold is benchmarked ahead of our peers.



Future Considerations

We recognise the need to proactively monitor and understand potential impacts of climate change as an organisation and an active member of the communities within which we operate. We will continue to explore ways to reduce the carbon intensity of our current and any potential future operations.

While our current operations portfolio minimise the potential to be exposed to long term climate-related risks, the long-term impacts of climate change must and will be considered in future strategic and operational planning, particularly where the operational life is considered over a longer timeframe through expansions, acquisitions or development projects.

We will simultaneously manage the shorter-term considerations of emissions management, medium term potential carbon constraint mechanisms (carbon prices) and technological developments, as well as monitoring the longer-term landscape within which future business decisions will be made.

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