A thesis submitted for the degree of Doctor of Philosophy at Monash University in January 2018.
Prepared by: Stephen A. Northey
Supervised by: Mohan Yellishetty, Gavin M. Mudd, Nawshad Haque
Funding for the project provided by CSIRO Mineral Resources.
Abstract
The mining industry is significant to national economies. However, existing studies of the mining industries water consumption and hydrological impacts are typically limited to detailed case studies of individual mining operations. Consequently, there are few industry wide datasets and studies available to understand how the water use impacts of the mining industry vary across regions, industry sub-sectors and hydrological settings.
A detailed literature review was conducted to determine how life cycle assessment and water footprinting methods have been applied to the mining industry. From this review, the major limitations and the opportunities for further use of these methods for assessments of the mining industries water use were identified.
Detailed analysis was performed to understand how copper, lead-zinc and nickel resources are situated in the context of regional water resources, climate regimes and life cycle assessment impact characterisation factors. The analysis demonstrated the common industry narrative that several major copper producing regions are more acutely exposed to these water risks than other sub-sectors of the industry. Furthermore, there is also a likelihood that the climate in many regions containing base metal resources will undergo changes over the coming decade that may alter the risk profile of hydrological, water quality and infrastructure risks at mining operations.
The spatial distribution of mine production in relation to water use impact characterisation factors was also assessed for 25 mined commodities. From this analysis, it was found that the results of studies may be sensitive to the choice of characterisation factors used and also the spatial resolution of the study. Assessing the industries consumptive water use impacts through the use of national average factors for the water stress index (WSI) and the Available Water Remaining (AWaRe) factors for non-agricultural water use is likely to lead to, on average, an overestimation of impacts for the mining industry. This is compared to assessments using watershed specific factors. Therefore, watershed based inventory development and impact assessment is strongly recommended for future life cycle assessment studies of the mining industry. This is one of the major findings from this study that industry future research should address.
The results of the study provide a quantitative basis for advancing discussions of the mining industries water use and risks, whilst also providing avenues for improving future life cycle assessment studies that consider the water use impacts of the mining industry and its products. Datasets were developed that can aid in the assessment of the industries water use impacts at national and global boundaries for many mineral commodities. This includes detailed datasets for a large number of mineral deposits. Through the combination of these datasets and life cycle assessment methodology, a more holistic assessment can be made regarding the contribution of the mining industry to achieving sustainable development
objectives.
Contents
1. Introduction
2. Background Methodology
2.1. Life Cycle Assessment
2.2. Life Cycle Inventory Data for the Mining Industry
2.3. Applications of Life Cycle Assessment to the Mining Industry
2.4. ‘Water Footprint’ approaches
2.4.1. Water Footprint Network Standards
2.4.2. ISO14046 – LCA based Water Footprints
2.4.3. Comparison of Approaches
3. Water Footprinting and Mining: Where are the limitations and opportunities? (View Journal Abstract)
3.1. Other Water Footprint related Studies of the Mining Industry
4. The Exposure of Global Base Metal Resources to Water Criticality, Scarcity and Climate Change (View Journal Abstract)
5. Production Weighted Water Use Impact Characterisation Factors for Global the Mining Industry
5.1. Abstract
5.2. Introduction
5.3. Background and Methods
5.3.1. Water Use Impact Characterisation Factors
5.3.2. Mine Production Weighted Averages and Boundaries of Assessment
5.4. Results and Discussion
5.4.1. Deviation between watershed and national average factors
5.4.2. Relative exposure of commodities to water stress and scarcity
5.4.3. Suitability of production weighted average characterisation factors
5.4.4. Limitations in the impact assessment of groundwater use
5.4.5. Implications for mine water use disclosures and reporting
5.4.6. Implications for life cycle inventory development
5.5. Conclusions
6. Intersection of Water Resources and Mineral Resource Development
6.1. Sourcing Water
6.2. Water as an Operational Risk Factor
6.3. Water and the Social License to Operate
6.4. Providing context to long-term mineral resource development and scarcity research (View Journal Abstract)
7. Water Use Reporting and Data for the Mining Industry
7.1. Water Use Reporting
7.2. Water Use Database Development
7.3. A Conceptual Framework for Mine Water Inventory Development
7.3.1. Water Quality Considerations
7.3.2. Life-of-Mine Considerations
8. Conclusions
Appendices
S.A. Northey. Assessing Water Risks in the Mining Industry Using Life Cycle Assessment Based Approaches. PhD Thesis, Department of Civil Engineering, Monash University, January 2018.