Mining creates mineral waste which has to be handled. The main challenge is that the volumes of mineral waste (tailings and waste rock) are large and sufficient storage capacity has to be available. There are three alternative disposal methods, (1) back-filling in underground tunnels or open pits, (ii) land fills above or below a water cover and (iii) sea disposal, deep or shallow. They have all challenging aspects according to a conference in Egersund, Norway in 2009.
SMC contributes with advice and evaluation of alternative disposal techniques based on BAT and environmental assessments.
Evaluation of environmental implications
The environmental risks which are related to mine waste handling varies due to different types of ores, associated metals or minerals and the environmental setting at the mine site.
SMC provides assessments of environmental implications and recommend solutions with minimum footprints and long term consequences.
The regulatory agencies require comprehensive monitoring programs as a prerequisite for disposal permission. To document the environmental impact of mining, a baseline study is necessary which document natural and seasonal variability in environmental quality. The base line study is followed by regular monitoring to detect the potential influence of mine waste disposal. The monitoring results are evaluated in relation to environmental standards and quality criteria and may be compared to predictive models.
SMC may provide services related to design of baseline studies and monitoring programs and evaluate the results against quality criteria, modeling and anticipated effects.
Communication of sensitive environmental issues to the public is a major challenge. If the communicated message is too simplified or too technical or academic it is difficult to achieve a good dialog about the real environmental risk. The dialog has to be based on mutual trust.
SMC may contribute to a better dialog between varies parties in the society, having hands on experience about environmental implications of mine waste management.
Environmental impact assessments (EIA)
The majority of mining projects require an environmental impact assessment (EIA) to obtain permissions related to waste management. An EIA should be based on documented effects from similar mining projects and site specific conditions. A baseline study in the area expected to be influenced by waste disposal should be designed to document pre-conditions and observe natural environmental variability. This is important to interpret monitoring data when the project is launched.
SMC may provide services related to initiation of an EIA regarding waste disposal alternatives and the need of documentation of disposal site suitability, natural variability and anticipated environmental impact. A roadmap for waste management is necessary.
There is a strong need of establishing a set of environmental acceptance criteria regarding waste disposal. Acceptance criteria are needed to distinguish between anticipated effects based on assumptions (and emotions) and real effects based on scientific documentation. Little focus has been on the difference between acceptable and non-acceptable risk. This requires quantification of the risk in short and long term.
SMC may contribute to establishment of accept criteria which are site specific, which take into account other user interests and special vulnerable disposal sites.
In addition to EIA, disposal of mine waste requires a discharge permit from the regulatory authorities. The permit is related to the amount of waste to be disposed and the physical, chemical, geochemical and toxicity characteristics of the waste. Additionally, the application for permit must also contain information about the site where the waste is planned to be disposed and the infrastructure and design of the disposal arrangement.
SMC may contribute in the process of producing an application for discharge permit by close cooperation with the mining company and the regulatory agency.
It is anticipated that R&D related to mining industry and waste management will lead to focus on gaps of knowledge and new research.
Technical innovation in the mining industry in the years to come may change the amount and the composition of generated waste. Focus should continually be on “clean mining” and “environmental sustainable mining”.
SMC may contribute to identification of critical knowledge gaps and needs of new research to minimize environmental risk related to waste management.