It is important to understand what coal seam gas extraction means for human health and the environment. Coal seam gas extraction is closely regulated by state, territory and Commonwealth governments, which legally require protective measures to be in place to safeguard health and the environment. While the exact requirements vary by jurisdiction, this regulatory framework applies to all aspects of the industry, including the handling and use of chemicals throughout the extraction process.
To increase the knowledge base about chemicals used in the industry and in recognition of the scientific and community interest in the risks of this chemical use, the Australian Government commissioned the National assessment of chemicals associated with coal seam gas extraction in Australia in June 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. 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 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.
Industrial chemical use and coal seam gas operations are closely regulated by state, territory and Commonwealth governments, which legally require protective measures to be in place to safeguard human health and the environment.
Legislation, regulations, standards and codes of practice cover the coal seam gas industry including workplace and public health and safety, environmental and water protection, managing and reusing waste water, and the transport, handling, storage and disposal of chemicals. Coal seam gas projects must be assessed and approved under state, Territory and Commonwealth environmental laws and may be subject to site-specific conditions including how the companies manage chemical risk. A case study of one of the chemicals from the Assessment – ammonium persulfate – is used to illustrate how regulations and industry practices keep people and the environment safe.
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.
Summary of protections in place
What protects human health and the environment?
|Approving, starting and managing coal seam gas projects|
Conditions of approval
When applying for approval for a coal seam gas project, companies must typically:
State regulators or the Commonwealth may set specific conditions of approval to protect health or the environment, including how the companies must manage, monitor and report on chemical risks.
Before a coal seam gas project can begin, companies must typically:
The companies’ plans and chemical use is subject to ongoing monitoring and regular review to ensure chemicals are being used in a way that minimises the risk of spills or leaks and any harm to people or the environment, occurring. Regular reviews also ensure that new chemicals or practices are included and plans remain current and relevant.
Responding to spills and leaks
If a spill or leak does occur, companies have an enforceable requirement to:
|Storing chemicals||Managing, storing and reusing waste water|
Controls on storage of chemicals are set by work health and safety, environment and water legislation at the state and Commonwealth level, as well as industry standards and codes of practice.
How coal seam gas waste water is managed, stored and reused is governed by state law, codes and policy covering water use, public health, environmental protection and coal seam gas industry regulation.
|Transporting chemicals||Handling and using chemicals|
Transport of chemicals is controlled by the Australian Dangerous Goods Code, state and Commonwealth work health and safety legislation, and environment and water legislation.
How industrial chemicals are handled and used is governed by national and state work health and safety legislation, industry standards and codes of practice, state legislation regulating coal seam gas, and company policy.
Other common uses of chemicals used in hydraulic fracturing
|Chemicals used in hydraulic fracturing||Other common uses|
|PROPPANTS (eg sand, silica and quartz)
Keeps the fracture open to allow gas and water to flow more freely
|High purity silica sands for glassmaking and metallurgical uses|
|MICROBIAL CONTROLS (eg tetrakis (hydroxymethyl phosphonium sulphate))
Helps stop the growth of organisms which could contaminate the coal seam gas and the fracturing fluid
|Household bleach, stain remover and disinfectant|
|BUFFERS, STABILISERS, SOLVENTS ETC (eg 2-Butoxyethanol)
Helps bond the chemicals and maintain the stability of the fracturing fluid
|Solvent, vinegar, medicinal uses|
|CLAY MANAGEMENT (eg Sodium Chloride)
Minimises clay swelling in the vicinity of the well and in the underground formation
|Salt-chemical-based dehumidifiers in domestic and other environments to absorb dampness/moisture from the air|
|GELLING AGENTS AND BINDERS (eg bentonite, polymers, guar gum)
Thicken the fracturing fluid to allow more sand to be carried into the fractures
|Pet litter, groundwater barrier, drilling mud|
|BREAKERS, SURFACTANTS, FRICTION REDUCERS (eg Ammonium Persulfate)
Assists in breaking down the chemical bonds and surface tension in the gel, allowing the chemicals to be pumped back out as a fluid
|Bleach, etching zinc, soil conditioner, surface cleaners, personal care products, medicines|
|pH CONTROLLERS (eg acetic acid)
Adjusts the pH of the hydraulic fracturing fluid to maximise the effectiveness of other additives
|Manufacture of pulp, paper, textiles, soaps and detergents|
|MINERAL DISSOLUTION AGENTS (eg hydrochloric acid, acetic acid)
Helps dissolve minerals and initiate cracks in the rock
|Household cleaning, descaling, food production|
|FOAMING AGENTS (eg 2-Butoxyethanol)
Helps carry the proppant and minimise water use
|Laundry detergents and household cleaning products|
|CORROSION INHIBITORS (eg Ethylene Glycol)
Prevents pipe corrosion
|Plywood, paint, confectionary, cleaning products and camping stoves|
While these chemicals are used in other industries, they are not used in the same quantity or concentration. Risks are managed according to the potential hazard and exposure in each industry.
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.
- New South Wales government protections
- New South Wales Environment Protection Authority
- Queensland government protections
- Queensland Department of Environment and Heritage Protection
- control of industrial chemicals
- water protection
- environmental assessments and approvals
- work health and safety
What the findings mean for: