Coal seam gas water
To produce coal seam gas (CSG), wells are drilled into underground coal seams, bringing water (CSG water) from the seams to the surface. This process reduces pressure in the seams which allows gas to be released.
CSG water contains varying concentrations of salt which must be treated to ensure it meets water quality standards before it is used for other beneficial purposes, such as: irrigating crops, watering livestock, for commercial uses, or injected into underground water systems called aquifers.
- Managing CSG water
- CSG Water Management Policy
- Beneficial use approvals
- Salt and brine
- Regulated structures including dams
- Evaporation dams
- Coal seam gas and drinking water supplies
- Coal seam gas water feasibility study
Managing CSG water
CSG operators must apply for an environmental authority (EA) before any work can take place. The environmental authority identifies potential environmental risks and imposes conditions to ensure these risks are properly dealt with.
As part of the application process, CSG operators are also required to show how they plan to manage CSG water. This will include information like:
- flow rate, quantity and quality of expected CSG water
- proposed management of CSG water, including: use, treatment, storage or disposal
- criteria for monitoring and assessing the management of CSG water
- proposed actions by the CSG operator should management criteria not be met.
CSG operators are also required to submit an annual evaluation of how effective and appropriate management of CSG water has been.
For example, managing CSG water may include a water treatment facility and using treated CSG water for dust suppression. The annual evaluation would provide information about the quality of the CSG water used for dust suppression, the results of any tests of the water treatment facility or failures of the facility, and any impacts on environmental values. If it is determined that CSG water has not been appropriately managed, the CSG operator will need to outline actions to remediate. Their environmental authority can also be amended to ensure that the water is managed properly. Read more about measurable criteria for the management of CSG water
CSG Water Management Policy
The role of the Coal Seam Gas Water Management Policy is to:
- clearly state the government’s position on the management and use of CSG water
- guide CSG operators in managing CSG water under their environmental authority
- ensure community understanding about the government’s preferred approach to managing CSG water.
The Coal Seam Gas Water Management Policy 2012 has been developed following consultation with community, industry and rural stakeholder groups.
The objective of the policy is to encourage the beneficial use of CSG water in a way that protects the environment and maximises its productive use as a valuable resource.
The objective of the policy is to be achieved by managing CSG water in accordance with the following two priorities:
Priority 1—CSG water is used for a purpose that is beneficial to one or more of the following: the environment, existing or new water users, and existing or new water-dependent industries.
Priority 2—After feasible beneficial use options have been considered, treating and disposing of CSG water in a way that firstly avoids, and then minimises and mitigates impacts on environmental values.
A report has been prepared that summarises the results of public consultation on the draft Coal Seam Gas Water Management Policy undertaken between 22 October and 19 November 2012. The report outlines the key issues raised and the actions or responses to those issues.
Consistent with a commitment in the policy, on 20 September 2013, the Environmental Protection Regulation 2008 was amended so that better quality CSG water is exempt from the definition of regulated waste. This change applies where groundwater has:
- a pH between 6 -10.5; and
- an electrical conductivity of less than 15,000 μS/cm.
This amendment means that additional tracking, transport and disposal requirements only apply to strongly saline CSG water, and brine concentrates. Importantly, this results in a reduction in regulatory burden for the majority of CSG water.
Untreated CSG water that does not meet the water quality standards or treated CSG water that is not of a suitable quality, will remain a regulated waste.
Beneficial use approvals
Beneficial use approvals allow CSG water to be dealt with as a resource instead of being disposed of and managed as a waste under the Environmental Protection Act 1994. The beneficial use approval for CSG water ensures it is reused and carefully managed to minimise any risk of environmental harm.
The department has developed a beneficial use approval for coal seam gas water. This is also called the General Beneficial Use Approval for Associated water and it details the requirements for using CSG water for aquaculture, coal washing, dust suppression, industrial and manufacturing operations, irrigation and livestock watering. This approval is available upon request. Please contact Permit and License Management Unit in the contact details given under Enquiries below.
Where the conditions of this approval cannot be met, it is possible to apply for a specific approval. Applications for a specific approval will be assessed in accordance with Chapter 8 of the Waste Reduction and Recycling Act 2011.
Approval of coal seam gas water for beneficial use guideline — provides information on applying for a beneficial use approval.
Permit and Licence Management
Ph: 1300 130 372 (Option 4)
Fax: (07) 3330 5875
Salt and brine
The treatment of CSG water using desalination technologies results in brine and, ultimately, salt residues that must be appropriately managed. The concentration and composition of salts depends on the characteristics of the CSG water and the treatment process.
The salinity of CSG water is typically measured as the concentration of total dissolved solids (TDS) with values ranging from 200 to more than 10,000 milligrams per litre.
By comparison, good quality drinking water has TDS value of less than 500 milligrams per litre. The TDS of sea water is between 36,000 and 38,000 milligrams per litre. Brine is defined as saline water with a total dissolved solid concentration greater than 40,000 milligrams per litre.
The CSG Water Management Policy requires that saline waste is managed in accordance with the following two priorities:
Priority 1—Brine or salt residues are treated to create useable products wherever feasible.
Priority 2—After assessing the feasibility of treating the brine or solid salt residues to create useable and saleable products, disposing of the brine and salt residues in accordance with strict standards that protect the environment.
Regulated structures including dams
The requirements for assessing the potential hazards of dams or levees (referred to as regulated structures) associated with planned CSG activities are outlined in the manual and guideline below:
- Manual for Assessing Hazard Categories and Hydraulic Performance of Dams - EM635
- Structures which are dams or levees constructed as part of environmentally relevant activities - EM634
CSG companies applying for an environmental authority must demonstrate via certification from a Registered Professional Engineer of Queensland that the design and construction of their regulated structure meets the hazard assessment requirements.
The guideline also contains a range of ‘model’ conditions that provides performance requirements set by the department including the requirement for CSG operators to maintain a regulated dam register. Obtain a template for a regulated dam register.
This risk management approach requires the resource industry to actively manage regulated structures throughout their life.
In all but exceptional circumstances, evaporation dams have been banned for CSG water, and existing dams will be either converted to other uses or decommissioned.
Once a dam is no longer being used for CSG operations it must be rehabilitated or modified for a different use (like a farm dam, if the landholder agrees).
Decommissioning and rehabilitation standards require contaminated water and underlying soil to be appropriately remediated.
Coal seam gas and drinking water supplies
A regulatory framework is in place to protect public health where treated CSG water is supplied for town drinking water.
CSG water providers must prepare a Recycled Water Management Plan before recycled CSG water is supplied for drinking water. This ensures that there are no adverse effects on a community’s water supply and the appropriate water quality standards are met.
Read more about the regulation for CSG recycled water.
Coal seam gas water feasibility study
This study examines the use of CSG water in the Queensland section of the Murray Darling Basin — a significant water source for agriculture and more recently, a location for CSG production.
The study considers the feasibility of using CSG water to relieve demand on groundwater for irrigation in heavily used aquifer systems near the Condamine River and help local communities to become lower water users.
Read more about the Healthy HeadWaters Coal Seam Gas Water Feasibility Study.