Coal Seam Gas
Coal seam gas (CSG) extraction is relatively new in Australia, but has been practiced in the United States for some time. It involves releasing gas (usually methane) from coal seams deep underground, often by injecting highly pressurised water and other chemicals into the coal seams to break them up.
Coal seam gas (CSG) extraction is relatively new in Australia, but has been practiced in the United States for some time.
It involves releasing gas (usually methane) from coal seams deep underground, often by injecting highly pressurised water and other chemicals into the coal seams to break them up.
CSG mining is sometimes seen as a relatively ‘clean’ form of mining, in terms of greenhouse emissions. However, the CSG mining extracts very large volumes of water and produces large amounts of waste salt.
CSG is just one form of unconventional gas extraction, with shale deposits offering another potential source of supply.
Australia has experienced rapid growth in CSG mining, with exploration and production licences covering much of the land mass. In the five years leading up to 2008, CSG production in Australia increased by 32 per cent a year (references available on request).
It has been suggested that one of the major risks of CSG mining is contamination of surface and groundwater supplies.
This is of particular concern because much of the CSG development has been associated with the Great Artesian Basin, one of the largest underground water reservoirs in the world, covering about 22 per cent of Australia’s land mass.
Little is known about the nature and doses of the chemical mixtures that are used during the mining process. This makes it difficult to accurately predict and measure the associated impacts on human health and the environment.
However, a number of the chemicals typically used in CSG extraction have been associated with hormonal disruption, fertility and reproductive effects, and the development of some cancers.
While some evidence exists from US operations of environmental contamination, there is relatively limited evidence so far regarding the actual health effects of CSG in Australian.
In 2012, a NSW parliamentary committee completed an inquiry into the environmental, economic and social impacts of CSG activities. In relation to health issues, the inquiry concluded:
- more data is needed on the impact of CSG on contamination or depletion of water resources;
- the chemicals used in CSG need to be tested more comprehensively; and
- CSG companies may not all be meeting their obligations.
A risk assessment of CSG operations in the Tara region in Queensland, published in 2013, failed to find a clear link between health complaints by some residents in the area and the impact of CSG activity on air, water or soil quality within the community.
Despite this, concerns are growing among many health groups.
A coalition of organisations including the Public Health Association of Australia, the Climate and Health Alliance, the National Rural Health Alliance, the Climate Change Health Research Network and the Australian Healthcare and Hospitals Association, recently hosted the Health and Energy Roundtable.
In a joint statement, the coalition noted that the risks to human health from energy and resources policy were not being well accounted for in current policy decisions. The statement called for a precautionary approach to policy, and for potential intergenerational consequences to be considered.
Members of the Public Health and Child & Youth Health Committee recently discussed CSG and its potential impacts on human health and the environment. Accepting that CSG extraction is likely to continue in Australia, Committee members voiced strong support for the establishment of an appropriate monitoring system for all CSG developments. Committee members also agreed that there was a critical need for health implications to be a key part of the CSG approval processes.
This is an issue the Committee will continue to monitor, and AMA members with additional information are invited to forward it to the Committee.
Published: 21 Apr 2013