State of the Environment Report 2007
Mining and petroleum industries are referred to collectively as the resources sector. The WA resources sector is a world-scale supplier of petroleum and mineral commodities (Geological Survey of Western Australia, 2005), including:
Mining and petroleum operations have a finite life during which there are three distinct phases, including exploration, production and decommissioning at the end of the project's economic life. The life span of resources projects can range from as little as a few months to 50 years. Impacts on the environment are varied due to the wide range of extraction and processing operations, phases of operational life, and the diverse range of environments where resource extraction occurs. This sector report presents only the significant environmental issues directly related to the extraction of minerals and petroleum - not downstream processing activities.
From a natural resources perspective, the mining and petroleum sector is unique in that the resource base (i.e. minerals, ores, petroleum) is extracted and not replenished over time. This makes it difficult to apply the concept of sustainability to this sector in terms of 'environmental integrity'. However, the sector is applying environmental stewardship practices to manage its environmental impacts, and is recognised for providing significant economic and social benefits to the State. In 2006, the value of sales from the resources sector was $48.4 billion. The sector contributes about 85% of the total value of State exports (Chamber of Minerals and Energy, 2006) and is directly responsible for about 5% of the State's total employment (Chamber of Minerals and Energy, 2005).
The State Sustainability Strategy outlines a vision for our natural resources by ensuring that they are '... conserved, protected, managed and used sustainably for the common good' (Government of Western Australia, 2003a, p. 108). The mining and petroleum sector has a vision that "minerals and petroleum production in Western Australia remains at world best practice and the industries help to establish the standard for sustainability" (Government of Western Australia, 2003, p. 139). The objectives for the sector include:
Estimates based on data collected between 1986 and 2002 indicate that the area disturbed by mining was approximately 162 00 hectares. Comprehensive data on the area disturbed by mining after 2002 was not available. Approximately 24 000 hectares of land was rehabilitated between 1986 and 2002.
Mining and petroleum operations are audited, through several mechanisms, for compliance with the Department of Industry and Resources and the Department of Environment and Conservation environmental conditions. This information has not been standardised to enable reporting as a headline indicator.
Annual greenhouse gas emissions from the resources sector nearly doubled between 1990 and 2002 to 12.3 million tonnes.
It is estimated that the sector's total water use was approximately 428 gigalitres (GL) in 1999-2000. Up to 30% of the water used on mine sites is recycled at least once.
Currently there are 67 producing oil and gas fields and 560 commercial mineral projects in the State, including 1222 operating mine sites (open pit, underground and quarries) which produce over 50 different minerals (Figure TS5.1).
During 2005-06, petroleum production for the State totalled 11.5 GL of crude oil, 5.63 GL of condensate and around 7.71 giga-cubic metres of gas. Production of other key mineral commodities during 2005-06 included 11.5 million tonnes of alumina, 161 tonnes of gold, 191 000 tonnes of nickel and 244 million tonnes of iron ore (Department of Industry and Resources, 2006a). The sector is experiencing rapid growth and projections indicate that sector output is likely to grow by 50-75% over the next decade (Chamber of Minerals and Energy, 2005).
Most of the land disturbed by mining activity is used for tailings dams/evaporation ponds, waste rock dumps/heap leaches, infrastructure or it becomes a pit. Estimates based on data collected between 1986 and 2002 indicate that approximately 162 000 hectares of land was disturbed by mining, which represents approximately 0.07% of the State's total land area (Figure TS5.2; Department of Industry and Resources, 2003). The area of land revegetated over this period was approximately 24 000 hectares. These estimates should be considered incomplete for this period as comprehensive data collection only began in 1995 and do not include disturbance from exploration. The area of land disturbed and rehabilitated post-2002 was not available, as reported information was not compiled comprehensively for these years. However, an increasing trend in the approved number of notices of intent to clear for mining between 2002 and 2004 suggests that the area of land being disturbed is rising (Figure TS5.2). In 2004 a new system for application to clear native vegetation was established with the introduction of the Environmental Protection (Clearing of Native Vegetation) Regulations 2004. During 2005 and 2006, applications were made to clear approximately 10 600 ha for mining. This data is not comparable with the data from the notice of intent process.
![Figure TS5.2: Area subject to disturbance and rehabilitation and number of notices of intent approved for mining in Western Australia. [Data source: Department of Industry and Resources. Note: ‘Disturbed’ includes areas where vegetation has been cleared and/or topsoil has been removed. ‘Preliminary rehabilitation’ includes areas that have undergone reshaping, capping and water/wind erosion control. ‘Revegetation’ includes areas that have established self sustaining vegetation cover based on data available through established reporting mechanisms but does not include all legacy sites.]](/site/files/images/Figure-TS5.2_Large.jpg)
The efficient use of natural resources is widely acknowledged in the mining and petroleum sector. This sector ranks second to agriculture in the total volume of water used in the State. Around half of the water used is of poor quality (naturally saline) and not well suited to most other uses. It is estimated that the sector's total water use was approximately 428 GL in 1999-2000. Up to 30% of the water used on mine sites is recycled at least once before discharge to tailings storage facilities or evaporation ponds (Economics Consulting Services, 2004). The major water resource issue for the sector is potential contamination. While precise data on the volume of water used by the sector is not available, data on water allocations to the mining industry is available (Figure TS5.3). Petroleum operations use very little water in the production process.
![Figure TS5.3: Proportion of mining sector water licence allocation by mineral commodity in Western Australia, 2004. [Data source: Economics Consulting Services (2004).]](/site/files/images/Figure-TS5.3_Large.jpg)
In comparison, energy use in the minerals and petroleum sector is increasing (Figure TS5.4). Despite efforts to improve energy efficiency within the sector, there has been an overall increase in energy use due to growth in sector activity.
![Figure TS5.4: Energy use in the resources sector in Western Australia. [Data source: Australian Bureau of Agricultural and Resource Economics (2005a). Note: Includes all industries in the Australian and New Zealand Standard Industrial Classification Codes under ‘Division B: Mining’ (Australian Research Council, n.d.).]](/site/files/images/Figure-TS5.4_Large.jpg)
Before mining or petroleum extraction projects commence, companies submit proposals to the Department of Industry and Resources for assessment. These proposals detail the measures that will be taken to minimise impacts on the environment and plans for closure and decommissioning once operations have ceased. Projects having proposed impacts to environmentally significant areas are also assessed by the EPA. Operating conditions included in environmental licences and ministerial approvals are employed to manage environmental risks and impacts. Conditions may address:
Mining operations are audited against criteria relating to various aspects of environmental performance. Currently, audit assessment scores are collated by the Department of Industry and Resources and presented in an environmental compliance index. In 2005-06, the overall score for mining operators was 106 against a baseline of 100 for the year 1998-99, which represents a slight improvement compared with the baseline year (Department of Industry and Resources, 2006b). This assessment and scoring process is currently being reviewed to enable compliance with the Mining Act 1978. Auditing of the petroleum industry is also undertaken to determine compliance with relevant environmental management criteria. In 2005-06, 100% of audited projects had no reports of major corrective actions (Department of Industry and Resources, 2006b). Data on levels of compliance with ministerial conditions set by the Minister for the Environment and licence conditions implemented under the Environmental Protection Act 1986 are unavailable.
Mining companies are required to undertake rehabilitation of land disturbed by mining upon a project's completion. Industry financial securities are held by government authorities to ensure rehabilitation is completed to a satisfactory standard. For the mining industry, the State Government holds around $455 million in unconditional performance bonds for the purpose of funding a program of rehabilitation works in the event that operations fail to meet rehabilitation standards agreed to in their conditions of approval (Department of Industry and Resources, 2006b). Petroleum companies are required to prepare decommissioning and closure plans and maintain adequate insurance against environmental risks such as oil spills. Currently, it is not common practice to require bonds for onshore petroleum projects.
While there are now processes governing the rehabilitation of land, this has not always been the case. There are many abandoned mines sites that were approved before rehabilitation protocols were established and there remain areas of land yet to be rehabilitated. Historical sites continue to have an impact on flora and fauna. On-ground exploratory drill holes can also act as pitfall traps for native fauna and contribute to local erosion and the formation of sinkholes. For example, a study undertaken in the early 1980s in Fitzgerald River National Park recovered the remains of nearly 300 marsupials and reptiles from two shallow uncapped drill holes (Geological Survey of Western Australia, n.d.). Surveying of abandoned mine sites has been ongoing since 1999 and 82% of known high priority sites have now been inspected (Geological Survey of Western Australia, 2005). Companies are now required to routinely plug drill holes and also to plug the holes of previous explorers on their acquired mining leases.
The environmental impacts of petroleum operations arise from drilling, ship and platform anchoring and the construction of infrastructure such as subsea pipelines, production facilities and shore-based facilities that process oil and gas. Onshore operations, such as oil and gas processing facilities, also generate environmental impacts. Active management is required to minimise land disturbance, impacts on biodiversity and loss of conservation and heritage values. When offshore drilling operations cease, all wells are plugged below the seabed surface.
Many operational discharges are authorised under project approvals and licence conditions. However, some accidental releases and spills occur. Releases to the environment from the mining industry potentially include spills of fuel, oil, chemicals, process water, saline borefield water or tailings. Tailings storage facilities are of most concern as they pose a risk to native flora and fauna and groundwater contamination. While mining facilities are audited and spills investigated by the Department of Environment and Conservation, comprehensive data on quantities of spills and releases to the environment are unavailable.
For the petroleum industry, releases to the environment can include oil, gas, fuel, other hydrocarbons and saline water. Data on accidental releases of gas or liquid hydrocarbons are submitted to the Department of Industry and Resources and the Department of Environment and Conservation. In 2005-06 there were 384 L of total hydrocarbons released during reportable incidents from onshore operations in the upstream petroleum industry. A total of 582 L of hydrocarbons were released in State and Commonwealth waters from offshore operations during the same period. Reportable gas venting totalled 387 200 m3 during 2005-06.
Acid mine drainage is an emerging issue for the mining industry. Acid mine drainage occurs when sulfidic minerals along the walls of open pits and in waste rock dumps and tailings storage oxidise, resulting in the release of acidic drainage water and dissolved metals which may impact on terrestrial and aquatic environments. The sector has recognised acid mine drainage as a significant issue and a number of industry groups are undertaking research to improve management of acid mine drainage .
Greenhouse gas emissions from the sector are increasing (Figure TS5.5). New gas ventures in the North West are expected to increase the State's carbon dioxide emissions by up to 10 million tonnes. Coal mining is also a significant source of fugitive methane emissions, with smaller amounts of fugitive emissions resulting from the extraction and storage of oil and gas. Some operators are working to improve efficiencies and consequently, emissions have declined on a per unit production basis for some projects. However, these improvements have been offset by significant overall growth in sector activity.
![Figure TS5.5: Total sector greenhouse gas emissions (carbon dioxide equivalent) in Western Australia. [Data source: Australian Greenhouse Office (2005).]](/site/files/images/Figure-TS5.5_Large.jpg)
The sector emits a significant quantity of sulfur dioxide, most of which is produced during the smelting of sulfide ores in mineral processing and some from the flaring of natural gas while extracting crude oil. There is an increasing trend in the emissions of sulfur dioxide from the sector (Figure TS5.6), with it being a significant issue in the Kalgoorlie-Boulder area (see 'Sulfur dioxide'). Dust is also recognised as having significant localised impacts, particularly around mining facilities in the North West (see 'Particulates'). Various dust suppression techniques are being developed and implemented by the sector.
![Figure TS5.6: Sulfur dioxide emissions from the mining and petroleum sector in Western Australia. [Data source: National Pollutant Inventory (2006). Note: Includes all industries in the Australian and New Zealand Standard Industrial Classification Codes under ‘Division B: Mining’ (Australian Research Council, n.d.). Reporting is only required for facilities emitting more than 10 tonnes of sulfur dioxide per year.]](/site/files/images/Figure-TS5.6_Large.jpg)
Sector activity is significantly influenced by the cyclical nature of commodity prices on international markets, and experiences 'booms' and 'busts'. Over the last ten years the resources sector has experienced a nominal growth rate of about 8% per annum (Figure TS5.7). As at December 2006, it was estimated that $81 billion worth of projects were either under construction or planned for the State. It is anticipated that the State will continue to experience growth in demand in the resources market fuelled by strong economic activity in Asia (Department of Industry and Resources, 2005c; Department of Industry and Resources, 2007). While some per unit production impacts on the environment (e.g. from atmospheric emissions and energy usage) are decreasing, the increasing demand for resource commodities and the corresponding increasing levels of production will continue to place pressures on the environment.
![Figure TS5.7: Value of Western Australia’s minerals and petroleum sales for selected commodities. [Data source: Department of Industry and Resources (2005c).]](/site/files/images/Figure-TS5.7_Large.jpg)
Sourcing water for use in resource extraction (particularly for the mining industry) has become a major problem in specific areas in recent years with increasing competition for water resources and the need to allocate more water for the environment. In particular, the rapid expansion of downstream processing related to the mining industry along the Pilbara Coast between Karratha and Port Hedland is resulting in increasing pressures on available water supplies.
The international focus on the contribution of industrial emissions to climate change has increased pressure on the sector to reduce greenhouse gas emissions. There is also a recognition of the importance of environmental health issues and the need to minimise particulate emissions. While per unit levels of emissions are decreasing, this will continue to be offset by sector growth.
Legislation: The relevant State legislation governing the environmental impacts of the sector includes the Mining Act 1978, several petroleum Acts and the Environmental Protection Act 1986. In addition to these Acts, there is a range of other Commonwealth and State legislation governing specific aspects of environmental management in the sector.
Sector initiatives: A number of industry-led initiatives aim to support sound environmental management and provide mechanisms for the broader public to identify organisations adhering to more stringent requirements. State-based industry organisations actively involved in supporting sound environmental practice include Chamber of Minerals and Energy, Australian Petroleum Production and Exploration Association Limited (WA), Chamber of Commerce and Industry, and Association of Mining and Exploration Companies (WA). International organisations that have developed codes of practice to guide responsible environmental planning and management of sector operations include:
Greenhouse gas emissions: An increasing number of resource companies operating in WA are members of the Commonwealth's Greenhouse Challenge Program (see 'Greenhouse gas emissions'). As of 1 July 2006, participation in the Greenhouse Challenge Plus program became compulsory for all Australian companies receiving fuel excise credits of more than $3 million and for proponents of large energy resource development projects.
Rehabilitation: The Department of Industry and Resources is undertaking a review of the environmental bond system for rehabilitation works which is investigating the adequacy of environmental bond rates, assessment methodologies and bond administration.
Abandoned mine sites: Since 1999, the Geological Survey of Western Australia (2000) has been undertaking an inventory of abandoned mine sites. The aim of this project is to provide a basis for planning of remedial action and rehabilitation of high-risk features on abandoned mines. Priority has been given to areas within 10 km of major towns or less than 1 km from main roads, where rehabilitation is now largely completed. Surveying has now commenced in areas within 5 km of smaller towns or less than 1 km from selected tourist routes.
Land and water contamination: The Contaminated Sites Act 2003 and supporting Regulations came into effect in December 2006 and has become an effective mechanism for improved reporting, assessment and management of soil and water contamination on mine sites.
Recognition of excellence in environmental management: The Department of Industry and Resources mission is to facilitate responsible resource development in WA. The department established the Golden Gecko Awards for Environmental Excellence in the Mineral and Petroleum Industries in Western Australia to recognise excellence and leadership. The awards acknowledge the outstanding contribution recipients have made in balancing environmental responsibility with the successful development of the State's resources (Department of Industry and Resources, 2005a). A Golden Gecko Award symbolises the commitment of companies and individuals to go beyond basic compliance with regulations, and provides public and industry recognition for their efforts.
The management of environmental impacts, including impacts on biodiversity and emissions to the environment, is essential to maintain broad community support for the operations of the mining and petroleum sector. Without such support, the sector's capacity to contribute to the State's economy is reduced, with significant economic impacts felt in regional WA, where a high proportion of employment is often due to the resources sector. Resource companies and their shareholders have a direct financial stake in implementing appropriate environmental management practices to manage pressures on the environment. As well as company funds being held in performance bonds, increasingly well-informed global consumers are basing investment and purchasing decisions on factors other than price, one of which is environmental performance (Chamber of Minerals and Energy, 2004).
9.17 Develop a comprehensive central database to collate and process environmental data and information prepared by the sector to enhance the State's environmental knowledge.
9.18 Establish sector-wide targets and benchmarks in order to assess whether implemented environmental strategies are achieving required outcomes.
9.19 Develop guidelines on rehabilitation and relinquishment standards consistent with the Australian and New Zealand Minerals and Energy Council/Minerals Council of Australia Strategic Framework for Mine Closure.
9.20 Develop strategies for more effective information exchange between mining companies on practical and effective mine closure and rehabilitation techniques.
9.21 Coordinate and advance research in rehabilitation techniques in WA.
9.22 Adopt collaborative processes when significant environmental values and significant resource development economic benefits coincide, to achieve multiple land-use objectives.
