Overlooking or inadequately remediating hydrocarbon contamination on mining sites can have considerable negative consequences for a company, including reputational risks, potential legal suits and settlements, as well as the possibility of having one’s operating licence cancelled.
With confidence in the mining sector at an all-time low due to the commodities price slump, experts from Environmental Resources Management (ERM), a leading global provider of environmental, health, safety, risk, social and sustainability related consulting services, have expressed concern that there might be lapses in adherence to good practice in environmental management as mining houses embark on cost-containment measures to ensure that their operations remain viable. Amongst the areas that might be affected is pro-active hydrocarbon remediation.
Based on persistent reports of soil and groundwater contamination on closed mines in South Africa it can be concluded that, even during times when the sector was experiencing a boom, there has not been a commitment to sound hydrocarbon remediation on some mine sites.
Partner at ERM, Jonathan Van Gool, points out: “Fuel spills often occur during routine operations, and fuel leaks can occur in fuel systems which are assumed to be leak-tight and failsafe”, explains Van Gool.
What complicates fuel spill management, which is supposed to be a routine activity, is sometimes an oversight in managing the unique risks faced with fuel spillages and releases, based on the fate and transport of hydrocarbon contaminants and the associated effects on exposed populations or environmental receptors, Stephen McKeown, Technical Director at ERM, adds.
Effective hydrocarbon remediation
According to McKeown, to manage hydrocarbon releases effectively, there are two scenarios to consider – where spills have not occurred but may inevitably occur due to poor management practices or deteriorating infrastructure, and where spills have already occurred and require intervention.
Forestalling the problem
It pays to be proactive by identifying higher risk areas and, accordingly, instituting measures to manage them. In effect, notes McKeown, ensuring that fuel does not get out of the system in the first place is more cost effective than managing the consequences of leaks. This can be achieved by incorporating leak management systems with suppliers during the design stage and by having processes to manage and record fuel supply and usage (i.e. stock reconciliation procedures).
- Engineering and environmental means
The fuel leak risk can be managed through utilising engineering controls and good environmental management methods. The former entails use of automatic tank gauging, regular volume reconciliation, and providing secondary containment including bunds or double-walled tanks. The latter entails acting on identified discrepancies to assess and address impact to the environment. Monitoring of fuel stock and regular maintenance are critical to keep track of stock and avoid releases from occurring.
- Fuel installation integrity
During mine design stage, an appropriate design can be agreed on with fuel suppliers for the fuel infrastructure to facilitate zero fuel leaks to the environment.
Despite the use of good fuel management methods, at some point fuel leaks can occur. In such cases, timeous and effective treatment of affected areas is key.
A plan to cater for fuel spill remediation should be developed, recommends Arjen van Schaijk, Partner and Contaminated Site Management Leader at ERM Southern Africa. “It is important to establish the severity and extent of the contamination by developing a conceptual site model, then identifying sources, possible pathways and the likely receptors to fuel impact. Subsequently, based on the level of environmental and/or human health risk, an appropriate remedial solution can be found.”
Methods for handling contaminated soil comprise two broad categories, namely in-situ and ex-situ methods. The former entails treating the contamination in-situ using agents or chemicals that stimulate degradation or break down the contaminants to harmless by-products, and the latter involves the removal of contaminated soil for ex-situ treatment (e.g. biopiling and land farming) or disposal. In many cases, in-situ methods are more practical and cost-effective as transport and disposal costs are avoided.
Importantly, ERM stresses, the sustainability of each remediation option should be incorporated into the evaluation process. For example, the impact to the environment of implementing the remediation system from a lifecycle assessment perspective needs to be evaluated against the benefit of undertaking the remediation of contamination.
The consequences of non-compliance
What mines might overlook is that in the long run, the perceived cost saving gains from not addressing fuel release impacts during mine operations could be offset by the potentially high costs of remediating hydrocarbon impacts during mine closure, the experts state. Three main costs come to mind.
Firstly, a mining company could irredeemably tarnish its reputation and erode its stakeholders’ trust in the organisation, resulting in loss of potential business.
Secondly, a mining company might incur exorbitant costs from court cases and settlements involving aggrieved communities.
Thirdly, in extreme cases, a mining company’s operating licence might be revoked by the regulator following serious contamination episodes. On the other hand, Van Gool argues: “one shouldn’t forget or underestimate the potential positive reputational benefits associated with sound environmental management and early action.”