By quickly identifying and developing solutions for risks that could cause delays, suspensions, or high management costs, mining companies can focus attention and resources where efforts are most warranted. Equally, the identification and realisation of opportunities enable companies, local communities, and other stakeholders to benefit from shared value.
This selection of case-studies from SRK's direct and recent experience demonstrates the range of issues and geographies where the global consultancy has applied its-risk management services. Risks from water management, social issues, and closure, as featured here, are high priorities in the mining sector, as they can result in significant cost and time implications for operators.
Water management in Mozambique
Water supply and management were the client's key concerns during a feasibility study for an iron and vanadium project in Mozambique. The area is characterised by a long, dry winter and a short, wet summer, and other planned mining projects presented competition for water resources.
The client recognised the need for a proactive water management strategy, and the value of a decision support tool to help make informed decisions about the impacts of operation decisions on water demand and availability.
SRK Consulting (South Africa) SRK developed an integrated water management dashboard for planning and presenting water data using GoldSim Monte Carlo simulation software. The dashboard incorporated stormwater information, floodline information and, more importantly, a dynamic water balance which allowed the user to test water intervention or environmental scenarios that can impact water demand and availability.
This allowed the client to model the implementation of strategies, and make decisions instantly, to prevent interruptions to operations due to water constraints. This dashboard was well received by the client, environmental authorities, as well as financial advisors for the bankable feasibility study.
Reputational risk in Peru
In an increasingly connected and well-informed society, controlling reputational risks is high on the agenda of many mining companies. To address this, SRK Consulting (Peru) S.A. has recently developed ‘Reputation Map and Change', a unique tool that uses multi-component methodology to promote transparency and risk management within an organisation.
Key areas covered by the methodology include: attitude to transparency, risk identification, change management, crisis communication, and training for communication with media and stakeholders.
‘Reputation Map and Change' has already been implemented for a client with rigorous E&S standards that had recently acquired an historical operation.
The old technologies and poor maintenance of the plant, prior to acquisition, had resulted in several environmental liabilities at the site, and social liabilities were also present through the plant being used as a collection point for material from artisanal miners.
SRK provided support to develop management plans and communication strategies to discuss and resolve the problematic issues with stakeholders. Thanks to the Reputation Map and Change, the client now has a list of the involved risks, a plan of change, and also a communication strategy to mitigate future issues.
Satellite remote sensing in South Africa
It is becoming increasingly important for mines to stay up-to-date with the latest monitoring technology in order to ensure water resources are monitored efficiently on site, particularly from resource-efficiency and compliance perspectives.
Remote sensing allows for the distant monitoring of the presence and surface distribution of moisture on Tailings Storage Facilities (TSFs) on a regular time scale. This provides valuable data to better inform water balances and TSF designs.
Remote sensing has been used on several mines in South Africa, and particularly for tailings storage facilities, to measure evaporation as an indicator of seepage, and to monitor the persistence of moisture deposited with the slurry.
SRK has used remote sensing information to help clients identify if and where surface seepage is occurring, allowing them to concentrate their efforts in drilling recovery boreholes to contain those pollution plumes. This has saved clients unnecessary expenditure in developing exploratory boreholes and assists in targeting boreholes where seepage is identified.
The use of remote sensing to measure and monitor evaporation is a relatively new scientific field worldwide and there is great potential for remote sensing to complement TSF monitoring programs into the future. This will allow for the better management of tailings dams and improved input into water balances.
Permitting and post-closure risk in the US
SRK Consulting (US) has been providing operational support and post-closure predictive assessments of potential risks associated with the ecological exposure of hazardous and toxic conditions at mine sites. Specifically, SRK uses state-of-the-art risk assessment methodologies to determine the risk to livestock, terrestrial wildlife, and avian/volant organisms from solutions and waters that accumulate in process ponds during operations, and open pits post closure.
For a recent project in south central Nevada, SRK used a modified approach that was originally developed and approved by the US Environmental Protection Agency. The approach effectively demonstrated that, under site-specific conditions, the accumulation of various chemical constituents, including general salinity, would not likely result in toxicological risk to area wildlife.
The pit-lake model addressed regulator concerns, and allowed the project to proceed in permitting without the need for extensive, and expensive, post-closure mitigation, including, but not limited to partial or full backfilling of the pit and long-term active water treatment.
Environmental (heap leach) risk in Chile
Heap leach pads are continuously irrigated with raffinate solution during their operational life. At the end of the active leach operations, once the volumes or grades of recoverable solution diminish, there remains the problem of long-term draindown of a solution that is unsuitable for discharge to the environment, and therefore requires containment and management.
In a recent study of a leach pad in an arid setting, a multi-disciplinary team from SRK Consulting in Canada and the UK developed a complex unsaturated flow model to evaluate the length of the active closure period required to reduce the solution inventory.
As the early period draindown volumes were too large to be contained in the existing raffinate ponds, and the operation was unable to discharge the water, the best closure option was to re-circulate the solution to the top of the pad.
The arid climate, which had previously been an operational constraint, was used as a benefit to decrease the time required to reduce the solution volume to a point where it could be managed within passive evaporation cells.
Numerical modelling was used first to assess and then to optimise the closure options while accounting for the inherent uncertainties of climate and heterogeneity of hydraulic behaviour.
Geochemical modelling of the recirculated solutions was used to assess the long-term chemistry and potential corrosive and scaling properties.
Using this approach, SRK provided a range of options to shorten the period of active management and achieve zero discharge at closure, as well as provide the client with the basis for assessing which option would be most cost-effective to implement.
*The authors are SRK senior consultants covering various discplines across the group