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.
The Assessment looked at scenarios where people could come into contact with a chemical during the coal seam gas production process, and whether the chemicals could be harmful to the public in these specific situations.
How the public could come into contact with a chemical
As members of the public are not involved in the day-to-day coal seam gas extraction process, they are unlikely to come into direct contact with chemicals. It is generally only through large-scale accidental spills and leaks that people could come into contact with the chemicals.
The Assessment looked at risks to the public in the following events:
- a bulk spill occurs during transport of a chemical to a well site and it is not notified to the authorities, closed off to the public, or cleaned up, then a chemical enters surface water (such as a river) that is used for drinking, washing or swimming
- a bulk spill occurs at a work site from a surface storage tank or pond and it is not detected, notified or cleaned up, then a chemical enters shallow groundwater or surface water that is used for drinking, washing or swimming
- a long-term underground leak occurs from a waste water storage pond and it is not detected, notified or cleaned up, then a chemical enters shallow groundwater or surface water that is used for drinking, washing or swimming.
Scenarios where the public could come into contact with coal seam gas chemicals
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These scenarios did not take into account all standard precautionary measures that are taken to prevent, contain, clean up or report a spill or leak. In reality 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.
In these pre-mitigation scenarios, the majority of chemicals (73 of the 113 tested) were found to be unlikely to cause harm to public health when used in coal seam gas extraction, even if they were to spill or leak in large volumes without the leak or spill being detected or cleaned up.
There were two scenarios where some chemicals could be a risk to the health of a member of the public in the absence of standard risk management measures: a large transport spill and a long-term below-ground leak from a storage pond. Both scenarios require the person to drink, wash with or swim in water containing the chemical on a regular basis over an extended period for harm to occur.
What the Assessment found
Scenarios where chemicals could potentially cause harm to the public
A member of the public could potentially come into contact with harmful amounts of coal seam gas chemicals in only two of the three tested scenarios - a large transport spill or an underground leak from a storage pond for a long period of time. Both scenarios require the person to drink, wash with or swim in water containing the chemical on a regular basis over an extended period for harm to occur.
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A bulk spill when transporting chemicals to the well site where the spill enters water used by the public |
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A long-term underground leak from a storage pond where the leak enters water used by the public |
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| Who might come into contact with the chemical | When they might come into contact with the chemical | What chemicals could cause harm | What protects the community from harm |
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| People who drink, wash with or swim in water containing a chemical that has spilled in a large transport accident or leaked from a waste water storage pond. |
Transport spill A transport accident occurs, resulting in a large spill of chemicals into water used by the public. Under this scenario, a truckload (up to 10,000 kg or 10,000 L) of the chemical would have to spill into nearby water, the spill would have to go undetected, and people would have to continue to drink, wash with or swim in the water for the chemical to pose harm. Storage pond leak An underground leak from a waste water storage pond occurs over a long period of time. Under this scenario, the leak would have to go undetected, the waste water would have to be undiluted, the storage pond would have to be within 100m of a groundwater well, the chemical would have to enter surface and groundwater, and people would have to continue to wash in and drink the water for a long period of time.
Both scenarios assume that coal seam gas companies will not clean up or notify government authorities of the spill or leak. In practice, they have an enforceable requirement to do so. |
If no protective measures were in place, 40 of the 113 chemicals tested could potentially cause harm to the health of people using contaminated water - 14 of these in the event of a leak from a storage pond, and 38 of these in the event of a large transport spill. These chemicals are:
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These scenarios looked at what could happen if standard precautions to prevent or control a leak or spill were not taken. In practice, the transport and use of industrial chemicals and the storage of waste water is strictly regulated by state, territory and Commonwealth governments. Legislation, regulations and national standards set out requirements for the safe transport of chemicals, including packaging, driver training, safety equipment and vehicle standards. These measures reduce the risk of a spill occurring, or of not being detected and cleaned up if it does occur. Coal seam gas projects also operate under conditions of approval state, territory and Commonwealth, regulations and industry codes of practice which require them to manage chemicals in a way that minimises the risk of causing harm. This includes how chemicals are handled and transported, and how storage ponds are designed, monitored and maintained. Companies must also have emergency protocols in place to detect and respond to spills and leaks, including containing, cleaning up and reporting the spill to relevant authorities. |
What protects the public
These scenarios looked at what could happen if standard precautions to prevent or control a leak or spill were not taken.
In practice, the transport and use of industrial chemicals and the storage of waste water is strictly regulated by state and Commonwealth governments.
Legislation, regulations and national standards set out requirements for the safe transport of chemicals, including packaging, driver training, safety equipment and vehicle standards. These measures reduce the risk of a spill occurring, or of not being detected and cleaned up if it does occur.
Coal seam gas projects also operate under conditions of approval, state and Commonwealth regulations and industry codes of practice which require them to manage chemicals in a way that minimises the risk of causing harm. This includes how chemicals are handled and transported, and how storage ponds are designed, monitored and maintained.
Companies must also have emergency protocols in place to detect and respond to spills and leaks, including containing, cleaning up and reporting the spill to relevant authorities.
Read more about protections for the public.
More information
What the findings mean for:
Information about:
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Scenarios where the public could come into contact with coal seam gas chemicals
Two scenarios where some chemicals could potentially cause harm to people if no protective measures were in place are:
- A bulk spill when transporting chemicals to the well site where the spill enters water used by the public (Relates to transport of chemicals and relates to people using water containing chemicals).
- A long-term underground leak from a waste water storage pond where the leak enters water used by the public (Relates to management of waste water and relates to people using water containing chemicals).
The scenario where all chemicals were unlikely to cause harm to the public: A bulk spill from a waste water storage tank or pond where the spill enters water used by the public.