Commonwealth of Australia 2010
Emissions management and monitoring
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- 78.1.2National Pollutant Inventory (NPI) Program
- 78.2Prevention of environmental contamination
- 78.2.2Groundwater management
- 78.2.3TSF management
- 80.Regulatory framework
- 81.Industry initiatives
78.1Emissions management and monitoring78.1.1Pollution managementEach state and territory stipulates controls on discharges of contaminants to the environment through legislation, policies and guidance. Table 11. lists primary legislation pertaining to environment protection and pollution management. Table 11.. Primary environment protection legislation for pollution management
78.1.2National Pollutant Inventory (NPI) ProgramAs discussed further in Section 14.1.2, emissions of ‘cyanide (inorganic) substances’ are included in the National Pollutant Inventory (NPI) program administered by the Department of the Environment, Water, Heritage and the Arts (DEWHA, 2009a; EPHC, 2007b). The NPI program was established in 1998 as a joint Australian Government, state and territory initiative, with each state/territory responsible for collecting emissions data from facilities and providing the collated data to DEWHA for publication on the NPI website. Individual facilities using or handling greater than 10 tonnes per annum of inorganic cyanides are required to report their emissions estimates to water, air and land. 78.2Prevention of environmental contamination78.2.1General frameworkPrevention of environmental contamination, as well as its assessment and management, is currently established through various state/territory regulations, policies and industry codes and guidance covering, for example, mine site operations (mill and heap leach), TSF management, contaminated sites assessment and management, environment protection, waste management and public and occupational health and safety. At a national level, the Environment Protection and Heritage Council (EPHC) oversees the National Environment Protection Measures (NEPM) program. NEPMs are broad framework-setting statutory instruments defined in the National Environment Protection Measures (Implementation) Act, 1998 (Cwlth). NEPMs outline agreed national objectives for protecting or managing particular aspects of the environment. The NEPM for the NPI (above) was the first NEPM to be made. The National Environment Protection (Assessment of Site Contamination) Measure (NEPC, 1999) establishes a nationally consistent approach for assessing site contamination through fourteen guidance documents, but does not provide guidance on how contaminated sites should be remediated. For mining operations, action to remediate a site is usually addressed through mine rehabilitation plans to guide what sort of rehabilitation is required and when it is to be completed, and inspection and auditing processes to ensure this occurs. The use of environmental performance bonds or mining securities serve to protect a state from financial liability should a mineral tenement owner fail to comply with mine site rehabilitation requirements (WA DIR, 2006; NSW DPI, 2002; Qld EPA, 2004). The publication Environment Australia (1999e) provides Best practice environmental management in mining guidance for mining agencies and industry on the avoidance of land contamination and contamination assessment and management in Australia. 78.2.2Groundwater managementWith respect to groundwater resources, the National Water Quality Management Strategy, ANZECC/ARMCANZ (1995) has developed guidelines for groundwater protection in Australia. This initiative stemmed from a review of the status of groundwater contamination and regulation in Australia by the Australian Water Resources Council (AWRC, 1990). The review found that for most states and territories, there was adequate legislation available to protect groundwater from contamination although it was fragmented across several areas of government in some states and territories. However, little protective action had eventuated. ANZECC/ARMCANZ (1995) provided the basis for a nationally consistent approach to the protection of groundwater from contamination in Australia. They distinguished between the terms ‘contamination’ and ‘pollution’ as pollution infers groundwater contamination ‘has deteriorated to a point where the ability of the water to support or maintain the existing or potential identified beneficial uses is diminished’. The framework enabled the states, territories and Commonwealth to develop policies and strategies, which are tailored to their specific legislative and resource management situations. The ANZECC/ARMCANZ (1995) guidelines for groundwater protection rely on a framework in which there is the identification and classification of beneficial uses and environmental values for each groundwater resource. The goal of groundwater protection in Australia is to ‘protect the groundwater resources of the nation so that these resources can support their identified beneficial uses and values in an economically, socially, and environmentally sustainable and acceptable manner’ (ANZECC/ARMCANZ, 1995). These classifications assist in determining the level of protection afforded to the groundwater resource. The choice of beneficial use classification for a groundwater body will depend on the quality of water present and the potential environmental values of the groundwater in the long term. The benefits of water use and non-use cover a range of exploitive benefits as well as environmental and conservation values. Environmental values are values or uses of the environment that are conducive to public benefit, welfare, safety or health and which require protection from the effects of pollution, waste discharge and deposits (ANZECC/ARMCANZ, 1995). Generally, the designated beneficial use of a groundwater body should aim to protect water quality to its greatest extent; however, there may be other factors to consider. A polluter pays principle is promoted. Once a beneficial use determination has been made, the developer of an industry or activity that has the potential to contaminate the groundwater body should bear the full cost of protection of the aquifer against any threats that the development may pose. On this basis, the developer would be required to show on a continuous basis that the activity did not pollute the groundwater body. 78.2.3TSF management79.General guidanceInternationally, the International Commission on Large dams (ICOLD), and the National Committees of its ~81 member countries, provides a forum for technical interaction amongst dam designers and constructors. ICOLD has published a range of technical guidance on dam design, construction and monitoring. The Australian National Committee on Large Dams (ANCOLD) is the Australian representative to ICOLD. ANCOLD is a learned society that has no regulatory powers, but has developed guidance on recommended practices on dam construction and operation (http://www.ancold.org.au/). The International cyanide management code for the manufacture, transport, and use of cyanide in the production of gold (ICMI, 2006) provides additional guidance for management of mine wastes and environmental risks. Guidance on the placement, siting, design, construction and safe management of TSFs and tailings, as well as environmental aspects (i.e. groundwater, wildlife) is available from various government and industry bodies in Australia and internationally. Most guidance on TSF and tailings management is relatively recent, developed largely since major TSF failures in Europe and Africa (Section 22.3.3). While recently developed guidance can be implemented at new facilities, some aspects (e.g. TSF siting studies, TSF type, liner and dam construction, operational processes) may not be capable of retrospective implementation at existing mine site operations and their TSFs. This may require the implementation of alternative strategies to manage risk issues. 80.Regulatory frameworkThe regulation of tailings and TSFs in Australia is principally a state and territory matter. The Commonwealth Environment Protection and Biodiversity Conservation Act (1999) has established a nationally consistent framework for environmental assessment of new projects and variations to existing projects, based on consultative agreement between the Commonwealth and state and territory governments. Tailings management is an important consideration in the assessment process for mining proposals at both the state and federal levels (MCMPR/MCA, 2003). Environmental planning/assessment and environmental impact assessment (EIA) procedures is established in Australia to allow analysis of significant developments/activities. The Cowal Gold Project, NSW provides a recent example of the EIA procedures established in Australia. The regulation of tailings deposition and management (including rehabilitation and closure) in all states and territories has been the responsibility of mining regulatory agencies. In some states, environment protection agencies regulate pollution issues (MCMPR/MCA, 2003). More recently, responsibilities relating to environmental management of mines in Queensland were transferred from the Department of Natural Resources and Mines (Qld NR&M) to the Queensland Environment Protection Agency (Qld EPA - Section 84.1.1). Most states and territories do not currently regulate concentration limits for cyanide or products in tailings discharged to TSFs. The regulation of TSF design, construction and ongoing integrity is more complex. In some jurisdictions, dam construction and operation is regulated by specific legislation (e.g. NSW’s Dams Safety Act 1978) while in other states and territories, TSFs are principally regulated within the mining regulatory agency regulations. In some instances, regulation is based on the size of the dam, with large dams being formally regulated and smaller dams falling under general regulation (MCMPR/MCA, 2003). The level of TSF management required to achieve environmental objectives is predetermined during the planning stage, being evaluated against site-specific risk-based factors such as the likely contaminants present and concentrations, potential effects on groundwater discharge areas and receiving environments, natural groundwater quality, groundwater level (e.g. potential watertable changes) and current and future beneficial uses of the groundwater. The risk of pollution of groundwater bodies can be evaluated by site-specific hydrogeological investigations, identification of beneficial uses and values, computer-based modelling and risk analysis, enabling risk management strategies to be developed into TSF design, construction, operational and post-closure requirements. This is typically initiated at the planning/development phase and carried through operational and post-closure phases. States/territory regulatory agencies require detailed siting studies before approving the construction and operation of TSFs and other facilities using or containing cyanide solution. The National Water Quality Management Strategy for groundwater protection in Australia is applicable (ANZECC/ARMCANZ, 1995). For example, the environmental impact statement for the Cowal Gold Project, NSW, included a TSF siting study in the approval process. Migration rates for cyanide (not including products such as cyanate and nitrogenous compounds) were simulated through computer modelling, which predicted minimal migration of contamination (i.e. probably not beyond the base of the TSF) and under worst-case conditions (i.e. continuous tailings impoundment, maximum permeability and low retardation and degradation) that cyanide would be unlikely to migrate more than 200 m, for which allowance was made in the final siting of the TSF (Train, 1999). In this instance, tailings cyanide concentration will be limited to 20 mg WAD CN/L (90th percentile) and 30 mg WAD CN/L (maximum) at the point of discharge into the TSF. In addition, the operating license conditions require that the Cowal Gold Project TSF and contained water storage facilities have a basal barrier or impermeable liner with an equivalent permeability of 1X10-9 m/s over a thickness of 1 m. A holistic approach to tailings management and groundwater protection from cyanide is proposed. It should be noted that such stringent permeability requirements may not be appropriate in other Regardless of the quality of the investigations undertaken during the design phase and the operational controls implemented to manage environmental risks from contaminants, uncertainties will remain regarding current and future potential risks. Monitoring provides an important means of validating planning assumptions and predictions about the expected behaviour of contaminants in the environment. State/territory agencies in Australia require groundwater monitoring around TSFs and other structures containing cyanide solutions in order to monitor groundwater quality and contamination. The Western Australian Department of Water (WRC, 2000b) has published a series of guidance documents on water quality protection for mining and mineral processing, including guidance on TSFs, TSF impoundment liner requirements for tailings confinement, water quality monitoring and groundwater monitoring. Liners are used to restrict seepage of leachate from containment and storage areas. Their purpose is to prevent stored material from contaminating the environment (WRC, 2000b). In general, selection of a liner system depends on the hazard posed by the contained material, susceptibility of the liner material to attack by the contained material, time span of containment, local soil conditions and vulnerability of the environment. The mining and environment agencies in WA assess all proposals for TSF lining systems, and may seek advice from the Department of Water. Non-synthetic clay liners are commonly used at TSFs, and low permeability areas (e.g. 10-9 m/s) are favoured when selecting sites, but no matter what the permeability, seepage control and management will also be required. A typical operating licence under Western Australia’s Environment Protection Act 1986 would require the licensee to manage the storage of all matter containing cyanide constituents within TSFs in a manner that prevents pollution. Migration of constituents of TSFs is required to be managed to prevent damage to vegetation and pollution of surface waters or underground water. Monitoring bores are required to be installed and data reported. A licence would typically also specify analytes and methods to be used to analyse groundwater samples. In Western Australia, relevant analytes typically include free, WAD and total cyanide (a range of other analytes is also required to be monitored). Some licences have specified acceptable limits for WAD CN in groundwater (e.g. 0.5 mg/L or comparison to the background concentration range), but licence conditions may vary from site to site. Western Australian Department of Environment and Conservation advises that rather than specifying limit values, cyanide monitoring is required to track any plume and enable focused management response. In NSW, Environment Protection Licence (EPL) conditions may require the monitoring of tailings cyanide concentrations. A standard EPL will identify sampling locations, sampling frequency, analytes and methods for analytical testing. Concentration discharge limits at strategic sampling locations are typically specified and licences typically refer to the relevant legislation (e.g. Section 120 of the Protection of the Environment Operations Act 1997). NSW does not set licence limits for groundwater contamination from a TSF. Licensees are required to undertake monitoring of groundwater to check whether contamination is spreading and the matter is considered in detail in the design/planning stage to ensure the TSF is well located and well designed. Most state and territory agencies do not include potential cyanide products such as cyanate, thiocyanate or ammonia in the schedule of analytes required for groundwater monitoring programs. In some states, the breach of a TSF liner and detection of contaminants in groundwater is not necessarily an automatic breach of compliance; however, where monitoring results indicate groundwater contamination has occurred above the specified acceptable limits or in contravention of planning criteria, risk management actions are typically required (e.g. installation of a groundwater recovery bore system, cessation of operations) with on-going monitoring until the issue is addressed. 81.Industry initiativesThe Mining Association of Canada has published guidance on the management of tailings facilities in collaboration with representatives of the Canadian mining industry (MAC, 1998). While there is no equivalent industry guideline for tailings management in Australia, the The Ministerial Council on Mineral and Petroleum Resources and the Minerals Council of Australia (MCMPR/MCA, 2003) indicates that industry’s commitment to improved tailings management is evident through the development of mechanisms such as the Australian Minerals Industry Code for Environmental Management (2000) and through the adoption of environmental management system standards such as ISO14001. The Code for Environmental Management encourages self-regulation by the industry, with improved performance and enhanced community consultation as key components (MCMPR/MCA, 2003). Some key elements include:
The Minerals Council of Australia recognises nine key principles of effective tailings management in its Tailings Management Policy adopted in April 2000. The key principles are:
The Ministerial Council on Mineral and Petroleum Resources and the Minerals Council of Australia (MCMPR/MCA, 2003) provide a strategic framework for tailings management in Australia. The framework is designed to provide a broadly consistent framework for tailings management across the various Australian jurisdictions. The framework is not a detailed set of guidelines for tailings management, and a comprehensive list of codes, guidance and procedures is already available. The Strategic Framework provides a set of objectives and principles for tailings management grouped under five key areas: Stewardship, Stakeholder Engagement, Risk Management, Implementation and Closure. The framework has been developed to encourage consistency of purpose by regulatory agencies and industry in the effectiveness of tailings management. Directory: data -> assets -> word doc -> 0017 0017 -> National Industrial Chemicals Notification and Assessment Scheme word doc -> Priority Existing Chemical word doc -> Rail safety news issue 6 – October 2011 word doc -> Review of Multiple Chemical Sensitivity: Identifying 0017 -> Rail Safety News Edition 8, December 2012 0017 -> Real-Time License Plate Localisation on fpga 0017 -> Careers network bulletin issue 6 July 16 2012 0017 -> Wiser science: Finding References inspec for Physics and Engineering 0017 -> Part A: Depth Study: The globalising world Popular culture and public policy Download 2.29 Mb. Share with your friends:
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