Environmental Management System Water Criticality
Northern Star values the diverse environments in which we operate, and we are committed to ongoing demonstrated performance improvements in our stewardship of these important ecosystems.
Our Environmental Policy, Global Standards and Environmental Management System (EMS) provide a framework to facilitate our management and protection of the natural resources we are proud to be given access to. Targeted management plans are developed to provide additional guidance on site and region-specific requirements. These documents and processes are regularly reviewed and updated to ensure proactive and continual improvement, and adaptation to new issues or risks that arise.
Northern Star’s environmental management system is based on the principles of ISO14001:2015. We have used the services of an independent third-party consultant to conduct a full assessment of our corporate and site EMS in terms of alignment and application. The assessment also incorporated a gap analysis against the ISO14001:2015 Standard to ensure our EMS is aligned to the Standard’s requirements.
This allows us to better understand areas for continuous improvement in our systems, procedures and processes by:
- Establishing objectives and processes as required;
- Implementing the processes;
- Measuring and monitoring the processes and reporting results; and
- Taking action to improve performance of our EMS based on results.
Our operations all operate under relevant government approvals, including Mining Proposals, Mine Permit (Alaska), Water Licences, and Operating Licences. All operations also have in place approved Closure Plans and set aside financial provisions for implementing these plans at the end of a mine’s life. We conduct our exploration activities in accordance with our tenement conditions and, where needed, Plans of Work.
Our environmental management capability is complemented by our corporate and site-based environmental professionals.
Access to water is a fundamental human right. Water is also critical to our operations. The majority of our sites exist in areas with high baseline water stress, and we are committed to using and managing this valuable resource sustainably to ensure shared users and the environment are not adversely impacted.
Our Water Management Global Standard and site-specific Water Management Plans further strengthen this commitment by detailing key practices and processes for managing water use.
Comprehensive water balances are also utilised across our operations to manage site specific water resources and ensure our site Environmental and Operational teams have clear oversight of water abstraction, recycling, discharge and consumption.
We understand that water is a shared asset and are diligent in ensuring our activities do not negatively impact our neighbours, stakeholders and peers. In the early planning stages of any significant borefield expansion, a detailed hydrological assessment is completed to ensure that a targeted borefield is fit for purpose and any potential impacts to neighbouring stakeholders are avoided where possible.
All of Northern Star's borefields are operated in accordance with relevant regulatory endorsed groundwater operating strategies.
We consistently look for strategies to improve efficiencies and reduce water consumption across our operations, in consultation with our stakeholders and other shared water users.
Net water consumption per operational centre (ML)
Key water uses across our operations are processing and beneficiation purposes, as well as dust suppression. The addition of tailings thickeners on many of our sites has increased our water efficiency, allowing for up to 80% of water within the tailings slurry to be recovered and recycled in the mill. The potential for additional thickening capacity will be considered for all prospective mill expansions across the business.
Total water consumption per operational centre (ML)
Freshwater consumption per operational centre (ML)
Further information on water metrics are available in our Performance Data Tables.
Reclamation & Closure Preparedness
Northern Star’s Operations are located in a variety of natural environments, each with its own unique biodiversity values. Our Biodiversity Management Global Standard provides the guidance for managing biodiversity across all our operations, with supporting plans and procedures developed at a site level to address issues specific to each site. Regional information and site-specific surveys provide guidance on the values to be protected at each of our sites.
Northern Star is committed to maintaining and conserving biodiversity values and applies the ‘mitigation hierarchy’ (avoid, minimise, rehabilitate, offset) when there is a potential for biodiversity impacts. All personnel, contractors and visitors are required to adhere to Northern Star’s policies, standards and procedures related to protecting biodiversity values.
Our Western Australian Operations are in the Goldfields region within the Eastern Murchison and Eastern Goldfields biogeographic regions, comprised of eucalypt and acacia woodlands and heaths, as well as expanses of desert dominated by shrubs and spinifex grasslands. Salt lakes are also a feature of the region.
These landscapes hold distinctive flora and fauna values that Northern Star aims to protect through site specific knowledge and management plans. Where possible, we also work with stakeholders to improve knowledge of particular species with the aim of promoting better species management outcomes across the region.
Our Pogo Mine is in the Interior Alaska Highlands Major Land Resource Area, characterized by wetlands, boreal forests, and alpine tundra with zones of discontinuous permafrost. The mine is bordered by steep mountain slopes and the Goodpaster River, classified as an anadromous river for Chinook and Chum salmon. There are no threatened or endangered State or Federally listed species within the Goodpaster watershed or Pogo Mine area.
To strengthen our understanding and management of potential impacts by each of our operations on biodiversity, flora and fauna surveys are undertaken in areas of proposed direct impact and surrounding areas prior to any disturbances. These surveys provide information on the biodiversity values surrounding our operations which can be included in site and project risk assessments.
All clearing works are carefully managed with both external approvals and internal disturbance permits required prior to any clearing. The internal permits cannot be issued without environmental personnel conducting relevant checks to ensure biodiversity values are protected.
Image of active Malleefowl nest construction from remote monitoring systems at Carosue Dam, Kalgoorlie Production Centre, Western Australia
Further information on biodiversity at Northern Star is available in our Annual Sustainability Reports, Performance Data Tables and our Biodiversity Values.
Northern Star has closure and reclamation plans at each of our operations, developed in accordance with our Reclamation and Closure Preparedness Global Standard and approved by regulators in each region. These plans are regularly reviewed in conjunction with the financial provisioning required for the eventual closure of each site.
We regularly engage an independent external consultant to undertake a detailed analysis of and update our closure provisioning across our assets. This includes reviewing estimates for salvage and demolition works, landform design, revegetation, and ongoing monitoring to ensure that progression towards achieving closure criteria can be demonstrated.
Reclamation and closure works present an opportunity to engage our local Indigenous peoples to assist in land management practices. Utilising the knowledge of Indigenous Peoples can assist in sites achieving the closure criteria set out in their closure and reclamation plans.
Western Australia’s Mining Rehabilitation Fund (MRF) commenced in 2013 as part of the WA Department of Mines, Industry Regulation and Safety’s (DMIRS) strategy to encourage responsible development of resources and a commitment by the Mining Industry to environmental and community safety.
Northern Star collects and reports its mining-related disturbance and rehabilitation data to DMIRS annually and pays the required levy in to the MRF Fund. When planning projects, Northern Star tries to use existing disturbed areas as much as possible as part of the land disturbance mitigation hierarchy. This ensures we limit our clearing of new areas as much as possible. Whilst most of Northern Star’s land rehabilitation will occur when sites are at final closure, we look for opportunities along the way to rehabilitate areas that are not required for future use.
Further information on reclamation and closure preparedness at Northern Star is available in our Annual Sustainability Reports.
Recycling and Landfill Distribution
Our efforts to minimise and manage waste across our operations are guided by our Waste Management Global Standard, which places a focus on reducing, reusing and recycling as priorities for waste management. Treatment and disposal of waste products into landfill or incineration facilities should be a final option considered. Each of our sites frequently considers additional opportunities to recycle materials where possible, reducing overall waste production.
Wastes that cannot be reused or recycled are disposed of in onsite landfill facilities or sent to offsite landfill and incineration facilities, dependent on the type of waste. For example, hydrocarbon contaminated materials such as oily rags are sent offsite for incineration as they are unable to be placed in landfill due to contamination risks.
Wastes are transported from our sites to licenced facilities and waste management service providers via approved freight companies with controlled waste licences as required. Onsite landfill facilities are managed in accordance with the relevant licence and permit conditions in each region to ensure risks to the surrounding environments are mitigated.
Distribution of Waste (Excluding Waste Rock and Tailings)
Further information on waste management metrics are available in our Annual Sustainability Reports and Performance Data Tables.
Potential Acid Forming Material
Acid mine drainage (AMD) is the formation of acidic water rich in metals which forms through the oxidation of sulphur-bearing rocks in the presence of water and oxygen. Pyrite (FeS2) is commonly found in metal ore deposits and can form AMD if exposed to the right conditions.
Northern Star conducts detailed assessments on our mine waste materials to determine if there is any risk of AMD being able to form and to enable early mitigation measures to be undertaken. We classify our wastes as being either Non-Acid Forming (NAF) or Potentially Acid Forming (PAF). This assessment provides an understanding of the material and the risk it poses to the environment and allows for specialised materials handling and disposal plans to be created for each waste and each location.
Where PAF material is encountered at our sites, a site-specific management plan is developed. In most cases, PAF material is usually encapsulated within waste rock dumps. These encapsulation cells are designed to ensure the most effective location and method for encapsulation and are covered with a minimum depth of two metres suitable compacted oxide or five metres of fresh rock. At Pogo, PAF is encapsulated within the dry stack tailings facility.
Waste Rock Management & Reuse
Waste rock is material mined from our operations that does not contain gold at economic levels. This material must be disposed of to waste rock landforms or backfilled into open pit or underground voids. Backfilling waste rock is Northern Star’s first preference as it eliminates the need to create permanent landforms in the environment, while decreasing safety risks associated with open voids. However, backfilling relies on availability and distance to barren voids and is not always practical.
Waste Rock Production (T)
Further information on waste rock metrics are available in our Performance Data Tables.
Tailings are a combination of the fine-grained (typically silt-sized) solid materials remaining after the recoverable gold has been extracted from mined ore, together with the water used in the recovery process. Northern Star deposits tailings material into four different types of tailings facilities across its operations.
- Paddock – style facilities: Most utilised in arid environments and consist of dams with walls constructed from compacted earthen material, slurry waste and water.
- In-pit facilities: These are used where open pit mining voids have been successfully mined of all ore and are then used for deposition and filling with tailings.
- Dry stack facilities: These facilities require water to be removed from the tailings before it is transported to the tailings facility.
- Underground tailings backfill (or paste fill): Tailings material can be utilised on some sites as a component of cemented hydraulic backfill underground. Most of the fines and liquid are removed from the tailings at onsite paste backfill plants and the remaining paste is delivered underground for use in controlled conditions.
Northern Star actively reviews its management of tailings facilities against both internal and external standards and meets the local regulatory requirements. Annual third-party inspections occur across all sites.
Further information on Northern Star’s tailings facilities are available here Northern Star FY23 Tailings Disclosure Report.
Tailings Production and Recycling (T)
Further information on tailings management are available in our Annual Sustainability Reports and Performance Data Tables.
Northern Star uses sodium cyanide in gold processing to dissolve gold and silver from the ore, enabling them to be extracted and recovered. Focused on protecting our workforce, surrounding communities and the environment from potential impacts associated with our use of sodium cyanide, Northern Star’s Cyanide Management Standard provides guidance for our sites on how to manage the risks associated with the supply, handling, transport and storage of sodium cyanide.
Due to its proximity to the City of Kalgoorlie- Boulder, Kalgoorlie Consolidated Gold Mines (KCGM) became a signatory to the International Cyanide Management Code (Cyanide Code) in 2008. The Cyanide Code is a voluntary industry program focused on the safe and environmentally responsible management of cyanide. KCGM has since recertified its compliance with the Cyanide Code in 2012, 2105, 2019 and 2022. As a signatory to the Cyanide Code, KCGM demonstrates that all activities associated with the use of sodium cyanide comply with the Cyanide Code and are managed in accordance with industry best practice.
Sites without nearby or adjoining communities are not signatories to the Cyanide Code but are regularly assessed to ensure they are compliant with the Northern Star Cyanide Management Standard and are aligned with the principles and standards of the Cyanide Code.
Northern Star requires all suppliers and transporters of sodium cyanide to our operations to be signatories to the Cyanide Code, providing confidence that they are adequately managing the risks associated with their activities relevant to communities and the environment.
Further information on cyanide management at Northern Star is available in our Annual Sustainability Reports.
Northern Star monitors and manages key air quality metrics across our operations and local communities located adjacent to our operations. Air quality is typically influenced by industrial emissions, cars, planes, household emissions including wood fired heaters, bushfires and controlled burn offs, dust from unsealed roads and construction development, degraded lands and many other sources.
Air quality results are reported to the Australian and United States Governments via:
- Australian data - National Pollutant Inventory (Department of Climate Change, Energy, the Environment and Water);
- Alaskan data - Toxics Release Inventory (United States Environmental Protection Agency).
Measured Air Emissions (T)
Our Kanowna Belle processing plant incorporates a roaster to allow processing of sulphidic ore. The sulphidic ore prevents gold from being extracted efficiently during the normal process. Kanowna Belle has implemented an Air Quality Control system (AQC). The system consists of a network of monitoring instruments dedicated to measuring sulphur dioxide concentrations and atmospheric conditions within the region (Kalgoorlie-Boulder, Kurrawang, Coolgardie and Kambalda), to ensure the roasting in conducted in controlled manner.
The AQC system combines dynamic SO2 network and meteorological monitoring data with predictive logic to calculate a recommended roaster status i.e., ON or OFF. This is supported by a roaster auto-shutdown sequence with a 5-minute delay in the event that roaster personnel do not act on an ‘OFF' recommendation immediately. This system allows us to manage potential air quality impacts from our operations.
Further information on air quality management and metrics at Northern Star are available in our Annual Sustainability Reports and Performance Data Tables.
Northern Star has an internal system for recording environmental incidents, including documenting incident details and corrective actions to be undertaken. The system enables automatic reminders to be sent to personnel responsible for implementing the corrective actions.
Northern Star’s reporting standards require all incidents to be reported, whether they cause actual harm to the environment or not. In this way, we are able to identify trends that could point to a potential for larger incidents. Where trends appear in our data, actions are taken to explore more closely what is leading to these.
Once causes have been identified, relevant environmental personnel are involved in developing an appropriate response. These could include increased inspections, additional training, particular awareness campaigns or specific actions aimed at remedying specific issues such as updating old equipment, for example.
Further information on environmental incident reporting and management at Northern Star is available in our Annual Sustainability Reports.
Carosue Dam TSF Cell 4 Project
Northern Star is currently expanding the Tailings Storage Facility (TSF) at the Carosue Dam Operations with the construction of TSF Cell 4 and associated infrastructure. The expansion of the TSF allows for the mine life to be extended for another 10 years. The Carosue Dam Project is located approximately 110km north-east of Kalgoorlie in the Pinjin region of the Eastern Goldfields. Below are documents related to the project.