The Australian Government commissioned the National assessment of chemicals associated with coal seam gas extraction in Australia in 2012.
The Assessment examined 113 chemicals used by companies in Australia between 2010 and 2012 in drilling and hydraulic fracturing for coal seam gas, to develop a stronger understanding of the risks these chemicals could pose to the health of workers, the public and the environment.
Read the Assessment Overview for a summary of the Assessment and its methods and findings.
The Assessment was a complex project of Australian Government partners, resulting in 14 reports and reviews.
What the Assessment involved
The Assessment was a collaborative effort of technical experts from the National Industrial Chemicals Notification and Assessment Scheme (NICNAS), the Commonwealth Scientific and Industrial Research Organisation (CSIRO), and the Department of the Environment and Energy.
The Assessment drew on technical expertise in risk assessment, chemistry, toxicology, ecotoxicology, hydrogeology, hydrology, geology and natural resource management.
The Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development (IESC) provided independent advice and critical review at key points in the development of the Assessment.
Experts from Australia, the United States Environmental Protection Agency and Health Canada reviewed the Assessment and found it and its methods were consistent with international practice and unlikely to underestimate risks.
The Assessment involved reviewing the scientific and technical literature and knowledge base, identifying the chemicals in use, developing new models and methodologies, and assessing the human health and environment risks of using the chemicals in coal seam gas extraction.
Read more about how the Assessment was done.
|Steps involved in the National Assessment of Chemicals Associated with Coal Seam Gas Extraction|
What the Assessment looked at
The Assessment examined 113 chemicals used by companies in Australia between 2010 and 2012 in drilling and hydraulic fracturing for coal seam gas, to develop a stronger understanding of the risks these chemicals could pose to the health of workers, the public and the environment. Industry reports that 59 of the 113 chemicals that were being used in coal seam gas extraction in 2010-12 were still being used in 2015-17.
The focus of the Assessment was solely on the above-ground (surface) handling of chemicals – it did not consider potential risks from chemicals entering deeper groundwater through drilling or fracturing operations. The Australian government has since commissioned additional research into deeper groundwater that found the risks to be very low. This is consistent with international studies that had shown that the greatest risk to human health or the environment from chemicals used in coal seam gas extraction is from spills or releases of chemicals during surface activities such as transport, handling, storage and mixing of chemicals. It is important to note that not all wells require fracturing and not all chemicals are used at all sites. Most of the chemicals are also commonly used in other industries. Some are used in homes.
The Assessment looked at scenarios in the coal seam gas extraction process where workers, the public and the environment could come into contact with the chemicals. The scenarios considered all parts of the extraction process including the activities listed above. Spills, leaks and accidents were the main release events identified in the scenarios. Worker scenarios also examined direct handling of the chemicals.
The Assessment took a very conservative approach, consistent with best practice, to ensure any pre-mitigation risks are not overlooked. It examined worst case scenarios and did not take into account all the safety and handling precautions that are taken to protect people and the environment from industrial chemical use. In reality, these precautions are required by law and significantly reduce any likelihood of potential harm occurring.
The Assessment found that the greatest pre-mitigation risk of harm to public health or the environment was in the event of a large-scale transport spill. Because they work with chemicals in more concentrated forms, the main pre-mitigation risks to coal seam gas workers is from industrial accidents and handling chemicals while maintaining equipment or mixing and blending. Even in this case, applying the required safety and handling precautions such as wearing protective equipment and promptly notifying and cleaning up spills, reduces the risk significantly.
Protecting human health and the environment
Australia has a strict regulatory regime for coal seam gas operations that requires safety and handling precautions to prevent spills and promptly control, report and remediate them if they occur. Strict work, health and safety regulations are in place to protect workers. Comprehensive national standards apply to the handling and transport of chemicals for all industries, including the coal seam gas industry. The Assessment has provided regulators and companies with an additional level of information directly relevant to the coal seam gas industry. This is new knowledge and information that will enable more targeted risk management actions and practices for the safe management of chemicals in coal seam gas operations.
Read more about what protects the environment, workers and the public.
Other ways the findings will be used
The Assessment developed improved, targeted methods for assessing the risks of chemicals used in coal seam gas operations, and included release of a consultation draft Chemical Risk Assessment Guidance Manual.
The Department commissioned CSIRO to conduct further research on deeper groundwater. This research shows how chemicals used in coal seam gas extraction might move from deeper groundwater to other parts of the environment, how long this movement might take, and what the concentrations of chemicals might be at receiving environments such as water bores and streams. The research found that chemicals remaining underground after hydraulic fracturing are unlikely to reach people or ecosystems in concentrations that would cause concern. This conclusion is based on natural dilution and degradation that reduce concentrations to negligible levels. Risks are therefore likely to be very low.
The research developed methods that can be used on a project-by-project basis to assess risks to human health and the environment from chemicals remaining deep underground as a result of hydraulic fracturing in coal seam gas operations. It did not assess the risks associated with any existing or proposed coal seam gas project.