CSG Mining – Environmental Impacts

Over the last decade there has been much discussion about coal seam gas (CSG) mining and its potential impacts on the environment. With the advancement of technology, currently in Australia and in particular Queensland, there are several large scale projects underway, and it is of high importance that any potential impacts are studied and known. This paper will discuss the process in which coal seam gas is mined, the roles of government agencies and the different legislations and the possible impacts of coal seam gas mining on the environment and ecosystems. This paper will also conduct a review of the current literature that discusses coal seam gas mining and the many issues that surround it, and then put forward recommendations and discussion points which will be based on the information which has been gathered in this paper.


Coal mining in Australia has been undertaken for over a century, and the gas which is trapped in coal seams has long been a problem for miners, especially in underground projects. It wasn’t until the early 1970’s that the potential to tap into this vast gas resource was realised and the first exploration projects were undertaken in the mid 1970’s and mining commenced in the early 1990’s. Coal is formed over many million years by the pressure placed on plant and other organic matter, and the gas, which is generally methane is formed by the bonding of the coal particles on the surface of the coal. The water that is present in the coal seam traps the gas between the surface of the coal and the water, effectively making it adhere to the surface of the coal. This process is called ‘Adsorption’ 1). The CSG industry in Queensland alone employs over 18,000 people and contributes over three billion dollars to the gross state product and provides over 850 million dollars of royalties to the state government 2).


There are several steps that are undertaken before any CSG can be mined. Firstly the target site needs to be identified. The next step in the process is to gain approval from the relevant government agencies for an exploration permit, and also permission and access are required from land owners and other relevant stake holders. Once these approvals have been granted, the next step is the physical exploration. This can be done in a variety of ways, which can include seismic data acquisition, drilling and logging 3). Once the depth, location and abundance have been measured, the next step is to gain a mining permit, which requires an environmental impact assessment and also community and landholder engagement. This process can take anywhere between twelve months and three years. If all criteria has been met, the construction phase of the CSG well can begin, after all of the engineering and well design has been completed. To access the gas, a hole is drilled into the coal seam. This hole is cased with steel and cement in order to prevent the mixing of aquifers that may be used for drinking water or irrigation. The depth varies on the position of the coal seam, however in Queensland the approximate depth is usually around 600m. For the extraction of the gas, a mixture of water and chemicals are forced into the coal seam, causing fractures, or what is known as ‘fracking’. When this fracture occurs, the water flows out of the cracks and the gas is released from the pores, which is then processed in the well 4).

Government, Legislation and Monitoring

In Queensland, the monitoring process is undertaken by the CSG Compliance Unit (CSGCU) which is overseen by the Department of Natural Resources and Mines. The CSGCU ensures that well operators comply with things such as:

  • Safety, land access and environmental issues
  • Dealing with the concerns of land holders
  • Investigating any events or incidents
  • Routine monitoring of CSG sites
  • Sampling groundwater from the site and surrounding locations

The CSGCU and the Department of Natural Resources and Mines has the power to revoke, suspend or alter any permits if there are any breaches in the conditions and or any other conduct which is not within the permit guidelines. The owner of the permit must also report any events or incidents that it thinks may be applicable and failing to do so can also result in the revocation of the exploration or extraction permits . The CSGCU can also refer the breach to the Petroleum and Gas Inspectorate, who are a branch of the Department of Employment, Economic Development and Innovation. This department ensures that all operators comply with the Petroleum and Gas Safety Act (2004) and the Petroleum and Gas Safety Regulation (2004). This department has the power to fine, prosecute or revoke licences and permits in conjunction with the Department of Natural Resources and Mines (Queensland Government 1b, Department of Employment, Economic Development and Innovation, 2011, 'Regulatory Enforcement Policy', Available: Accessed 1st May 2014)).

The department also monitors the water management at CSG wells, and has provided a series of guidelines that must be adhered to during the life of the exploration and extraction. In 2012 the Queensland Department of Environment and Heritage Protection outlined a CSG water management policy which gives guidelines to how to manage, treat and dispose of any water that is brought to the surface during extraction or exploration. This includes the measurement of pH levels and also conductivity of the water in order to avoid highly saline or acidic water damaging surface environmental ecosystems. This is tested annually and includes provisions for the storage and treatment of water that is deemed to be potentially harmful to the environment.

In summary, all CSG operations in Queensland must comply with the following acts/codes/regulations, in conjunction with the guidelines discussed above:

  • Gas Industry Code, 2003
  • Gas Supply Act, 2003
  • Gas Supply Regulation, 2007
  • Petroleum and Gas (Production and Safety) Act, 2004
  • Petroleum and Gas (Production and Safety) Regulation, 2004
  • National Gas (Queensland) Act, 2008
  • Energy and Water Ombudsman Act, 2006
  • Coal Mining Act, Queensland, 1999
  • Coal Mining Safety and Health Regulation, 2001


There have been serious concerns within communities and other organisations regarding the possible environmental impacts of CSG mining. These impacts can occur during the exploration, construction and extraction stages of CSG mining and impact the following:

  • Flora and fauna
  • Geology and soils
  • Surface and ground water

Flora and Fauna

During the exploration and construction phases, there is serious potential for impacts on flora and fauna. This can occur due to initial clearing of flora for the building of roads, parking areas and ultimately the final position of the well will mean the total eradication of the plants/trees that are currently located in that area. These impacts will affect both terrestrial and bird species. There will be a reduction of area for animals such as snakes and lizards in which they can find food resources and also areas in which they can find shelter from climatic conditions and predation. Birds will be affected by having a reduced number of trees in which they can nest and breed, thus increasing the competition for the remaining trees with other similar species, whilst also reducing the amount of available food. Both flora and fauna can also be affected by the by-products created by the CSG mining process, such as contaminated ground water being brought to the surface.

Geology and Soils

CSG mining can have significant impacts on soil and soil composition. There is potential for soil contamination during the exploration and construction process by the use of heavy vehicles which contain diesel and hydraulic fluids, which can impact soil compositions in the event of a significant uncontained spill. The water which is brought to the surface after the fracking process may contain high levels salt and also the possibility of heavy metals and radionuclides. This water is commonly stored in salt pits and brine ponds, as there is currently no solution as to how to neutralise this water. Any release of this contaminated water into natural surface or underground waterways can have an extreme negative impact, such as the changing in soil composition after absorption of these heavy metal and radionuclides which can alter the areas in which certain plants or other flora can grow, thus impacting the surrounding environment as a whole 5).

Surface and Ground Water

The possible contamination of surface and underground water caused by CSG mining is an area of great concern. The contaminated water which is brought to the surface by the fracking process may contain very high levels of salt and also heavy metals and radionuclides. There is also potential for below ground aquifers, and more critically, the Great Artesian Basin itself to become contaminated during the drilling process. The Great Artesian Basin is the largest body of underground water in the world and covers most of Queensland, and is a critical environmental resource for natural habitats and also human use for agricultural purposes.. Such a contamination could have disastrous effects for both people reliant on the bore water but also for flora and fauna. Any contamination of water in creeks and rivers can have a devastating effect on fish and other marine inhabitants, and have a flow on affect which may be felt hundreds of kilometres away 6).

Literature Review

The amount of literature and peer reviewed papers regarding the environmental impacts of CSG are limited, so it is important that further research is conducted in this area in the future. There are several differing views and studies which have been conducted into the impacts of CSG mining, with most of the literature focussed on the impacts on water systems. The main concerns are the possible contamination of ground and surface water from heavy metals, methane and sodium. There is also some literature that supports CSG mining and believes that it is a viable energy source due to its lower greenhouse gas emissions and the reduction of the risk of underground coal mining explosions due to methane build up and also some studies and papers that concede that there are both risks of environmental damage but also believe that there are economic and environmental benefits that can be derived from this process.. Please see Tables 1.1, 1.2 and 1.3 for the differing views and results.

Articles on Negative Impacts

Groundwater management and coal bed methane development in the Powder River Basin of Montana

This article discusses the impacts of CSG mining in Montana, USA. The author simulates the hydrological impacts of this mining process and the effects it has on the water capacities of groundwater, wells and springs. The paper concludes that CSG mining will potentially have a significant effect on these water sources, reducing the capacities by up to 40% and requiring a recovery period that could take between 45 and 200 years, within 29 kilometres of the well sites 7).

Directions for social research to underpin improved groundwater management

This article discusses the different processes and papers and how they identify the risks that CSG mining poses to groundwater systems and what conclusions were determined from these studies. This paper concluded that there was a significant risk to groundwater systems from CSG mining, and also the extraction of water from aquifers cause a depletion in the volume of groundwater which cannot be recharged in the long term by natural methods 8).

Coal seam gas water from Maramarua, New Zealand: characterisation and comparison to United States analogues

This study concentrates on the variance in ground and surface water quality from a CSG mining operation in New Zealand, and compares the finding with other CSG mining operations along with areas that have no mining at all. This paper concludes that in the CSG mining areas, there was a significant increase in the amount of sodium, chloride and bicarbonate. These levels were elevated in comparison to non-CSG mining areas however were consistent with other CSG mining operations worldwide. They also conclude that it will take a very long period of time for aquifers to recharge, and suggest further research in this area 9).

Hydrogeology of a coal-seam gas exploration area, southeastern British Columbia, Canada: Part 1: Groundwater flow systems

This paper discusses the potential effects of CSG mining on groundwater systems in Canada and how this affects the surrounding environment and ecosystems. After running a simulation which tried to replicate the potential recharge rates of the two rivers which are located within the potentially affected area, the authors concluded that the amount of water which would be lost during the CSG process would exceed the recharge rates, which could potentially affect the groundwater and surrounding areas 10).

Environmental aspects of a field-scale underground coal gasification trial in a shallow coal seam at the Experimental Mine Barbara in Poland

This study was conducted in order to measure the environmental effects of CSG mining. A two week trial was run in a temporary CSG mine in order to measure the amount, if any, of contaminants that could potentially be released into ground and surface water systems. The authors concluded that the CSG mining process caused the contamination of the water systems by releases organic and inorganic compounds into the water, such as heavy metals, ammonia and cyanide. It was determined that when left in its natural state, the CSG released very little contaminants into the water 11).

The mining and burning of coal: effects on health and the environment

This paper discusses the various potential health and environmental impacts of coal mining and burning, including CSG extraction. The authors concluded that there was significant risks to both human health and environmental systems due to CSG mining. They provided two examples of cases in Queensland where groundwater was contaminated with combinations of toluene, benzene, ethylbenzene and xylene 12).

Coalbed methane: a new source of energy and environmental challenges

In this paper the author describes the potential environmental impacts of CSG mining in the United States, a topic which is quite controversial among citizens and scientists alike. The paper concludes that CSG mining poses a significant risk to ground and surface water, wildlife and surface ecosystems from exploration, construction and extraction of CSG 13).

Positive articles about CSG mining

A review of Australia’s natural gas resources and their exploitation

This paper discusses the different gas extraction projects that are currently underway in Australia and the potential impacts and issues that may be faced into the future. The authors conclude that whilst there is some risk of water contamination due to CSG mining, properly monitored and maintained, there is little risk of any major contaminations, and that the economic benefits of CSG mining outweigh the risks 14).

The effect of zeolite treatment by acids on sodium adsorptionratio of coal seam gas water

This paper discusses the high levels of sodium ion which are found in CSG waters, and the potential of zeolite being used in order to treat this water in order to reduce the risks of contaminating ground and surface water systems in CSG mining areas. The authors concluded that zeolite can be effective in reducing the sodium levels in CSG water by up to three times, however the zeolite is only effective after being treated and activated firstly with acid. They also conceded that more research was required in order to gain more consistent test results 15).

Coal mine methane: A review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction

This paper discusses the different methods and ways in which CSG can be extracted in order to reduce the risk of explosions and air contamination in underground coal mining operations. The authors conclude that there are several positive aspects to CSG mining, including the reduction of underground mining explosions, an increase in economic benefits and also the environmental benefits of burning natural methane over the burning of coal 16).

Life-cycle greenhouse gas emissions of shale gas, natural gas, coal, and petroleum

This study aimed to discover whether the gas that escapes during the extraction process of natural gas outweighs the environmental benefits of burning this gas in comparison to other fossil fuels. The paper concluded that even though small amounts of gas escaped during the mining process, there was still a significant environmental benefit to using natural gas when compared to coal and petroleum 17).

Positive and negative impacts of CSG mining

Coal Seam Gas: Issues for Consideration in the Illawarra Region, NSW, Australia

This paper discusses the emergence of CSG mining in Australia and the various challenges and potential environmental impacts that this sort of mining may pose in the future. The paper concludes that CSG mining in Australia has high potential for economic growth, however there are some serious risks of environmental damage in the form of ground or surface waters contamination and also damage to ecosystems from surface mining operation in relation to CSG, and further research into this area is required for a balanced review 18).

Opportunities and challenges to coal bed methane production in Australia

This paper discusses the issues that surround CSG mining in Australia, and evaluates the environmental, social and economic impacts from this method of mining. The author concludes that whilst there are some economic benefits to CSG mining, there are real risks with water contamination and damage to ecosystems due to this contamination 19).

Coalbed methane: From hazard to resource

This paper discusses how CSG has evolved from a major hazard in underground coal mining operations into a clean burning fuel which can be used in many different industries. The author concludes that whilst there are still some environmental risks in CSG mining, the industry is still in its infancy and technological advancements in the future will see countries derive further economic benefits from this resource 20).

Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing

This paper discusses the report that CSG mining practices in Pennsylvania and New York caused methane contamination of the drinking water due to the fracking process. The authors ran a series of tests on water samples from the areas of concern and concluded that there was no contamination of the drinking water, and the levels of methane or other hydrocarbons were not higher than the control samples. They suggested that there needs to be greater stewardship for CSG mining in order to restore public confidence 21).

Environmental Impacts of Hydraulic Fracturing

In this book the author describes the potential environmental impacts of hydraulic fracking as a means of extracting CSG. The author concludes that whilst there are some concerns about the environmental impacts of CSG mining, it is a required resource extraction method due to its economic benefits and also due to natural gas being a cleaner energy to burn 22)


As mentioned in the literature review, there are a wide range of views, opinions and conclusions that are made by scientists and other experts in regards to CSG mining. There appears to be little or no doubt that the process of extraction creates a means by which several different types of contaminants, heavy metals and sodium can rise to the surface, thus having potential to contaminate water and soils. The effects of such a contamination can be widespread and devastating on several different types of ecosystems. In the literature that was cited in Table 1.1, the general consensus is that the CSG extraction and fracking process creates an unacceptable amount of risk of environmental damage and also a reduction in recharge rates of underground aquifers due to the water being brought to the surface during this process, whilst the construction phase can cause potential surface damage to the surrounding environment 23).

The secondary school of thought on CSG mining is the economic benefits. Several of the authors cited in the literature review in Table 1.2 claimed that there were many benefits and positive outcomes which could come from CSG mining, and that any possibility of environmental impacts and damaged were outweighed by the economic benefits from the sale of the gas and the creation of employment opportunities, the reduction in the risk of explosions in underground coal mines due to the reduction of methane build up in pits and tunnels and also the environmental benefits of extracting a fuel which burns cleaner than petroleum or coal. Some studies show that there is a considerable reduction in greenhouse gas and carbon dioxide emissions due to the burning of natural gases such as methane 24).

The third main theme from the literature that was reviewed was the studies that conceded that CSG mining posed both an environmental concern whilst also being important for economic and safety reasons. The authors of these studies were unanimous that further studies are needed in order to determine the full picture in regards to CSG mining. In summary, the main points to come out of the literature reviews were as follows:


  • Contamination of waterways both surface and underground by heavy metals and other hydrocarbons
  • Reduction in aquifer capacities
  • Surface environmental damage to ecosystems due to exploration and construction of CSG mining wells


  • Economic benefits for both governments and employees working in the industry
  • Environmental benefits of the burning of natural gas in comparison to petroleum and coal
  • Safety benefits from the extraction of methane in order to reduce the risk of explosions in underground coal mining activities


In light of the concerns that are raised within the literature, it is recommended that CSG mining should not proceed until there is more research conducted into its potential impacts. If this is not possible or viable, then some of the following steps should be followed:

  • An increase in environmental conditions that companies must adhere to
  • Improved reporting and monitoring of CSG mining processes
  • Increase in ground and surface water monitoring
  • Harsher penalties for individuals and companies who do not comply with environmental or other conditions
  • Reduction in surface footprint by reducing the size and frequency of vehicles used in exploration and construction
  • Research into alternatives to fracking
  • Improvement in extraction processes in order to reduce water and gas leakage
  • Reduction in red tape and creation of a single code of practice, legislation and code specifically for CSG


This paper has discussed the various issues that surround the controversial topic of CSG mining. The CSG mining process was discussed and the relevant legislations, laws and codes were outlined, using Queensland as an example. The possible environmental impacts have also been discussed, and several papers and studies were used as examples in the literature review. The discussion section talked about the general direction in which the literature was leading, although there are several schools of thought for and against the CSG mining process. In light of the various literature that was cited, there is a strong probability that the current processes used in the extraction of CSG will pose a significant risk to ground and surface water, geology and soils and also flora and fauna. There is also a strong case for the mining of CSG due to its economic and other perceived benefits, however the cost of a major environmental incident, such as contamination in The Great Artesian Basin, could potentially create an environmental catastrophe that will cost several times more than any economic benefit that the extraction of this gas. Whilst there are currently some stringent conditions that need to be met, companies and government departments can become bogged down in all of the different codes, laws and legislations that currently cover CSG mining. This confusion and wasting of time and money could be best spent in finding improved alternative natural gas mining processes, as there is significant economic and environmental benefits that can be derived from natural gas as an alternative to other natural resources which are high in carbon dioxide and greenhouse gas emissions.

Environment | Energy

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