by Jack Caldwell
In British Columbia there are over 60 mines with the potential to generate acid mine drainage . At least 50 are closed and in long-term care. Bellafontein and Price, regulators in BC, call for compilation of Environmental Management Plans for each site.
Each site-specific plan would focus on the mine's acid generation potential and plans to deal with drainage. Plans would include sections on background information, an assessment of the risks and uncertainties, monitoring programs, contingency plans, and resources to implement contingency plans.
The authors postulate that site-specific issues need to be presented in a holistic fashion that provides for mitigation strategies that prevent drainage and/or provide for indefinite treatment and control. They recognize covers maintenance and chemical treatment as two of the most significant aspects of long-term operations. The same objectives set out by the authors could be achieved in other jurisdictions by comprehensive Environmental Impact Statements and Operating and Closure Plans that are regularly updated and faithfully implemented.
Rio Tinto has gone much further than it is required by law in any of the countries where it operates mines . At a corporate level they have initiate and undertaken a review of conditions and practices at twelve mines and will continue for all their properties.
The review ranks acid mine drainage potential at each property on the basis of geology, incipient acid rock drainage risk, scale of disruption, transport pathways, and sensitivity of the receiving environment. A team of experts prepares a report to mine management that describes the situation, highlights risks, and suggests a plan of action to reduce risks to acceptable levels.
The authors note that while the cost for the program is high, they believe they will result in significant benefit to corporate reputation and long-term reduction of costs as Rio Tinto continues to do its normal business-namely conceive, design, build, operate, and close mines.
The law, policy, and practice of mine waste disposal and seepage control in the European Union as described by Amezaga and Younger, professors at the University of Newcastle, appears to be complex, in a state of flux, full of gaps, and of no particular general applicability internationally or mine-specifically with regard to proper practice related to acid drainage. .
The Canadian federal government is spending $80 million a year towards its $900 million liability for contaminated sites, many of them old mines, as part of the Northern Contaminated Sites Program . Using a risk assessment approach the government is identifying risks at contaminated sites and taking action at the most risky ones. All nine sites so far evaluated involve risks of tailings impoundment failure and/or seepage impacts that demanded action. Clearly the cost of dealing with acid drainage in the north of Canada is high and will continue to be for an indefinite future.
SOCIAL, GOVERNMENT AND SUSTAINABILITY ISSUES
Two papers by consultants explore the all-too-real issues facing consultants evaluating the potential for acid drainage at new mines in developing countries: lack of sufficient data, time, or budget; impatient mine developers; indifferent or non-technical regulators; political realities; and pre-existing contamination from artesanal miners. Suggestions include: use of professionals; extrapolation of databases from other mines in other countries; clear communication of risks; and caution in decision making [1250 and 1903].
| Prev | Next | Back To Top |