Reports released on CSG brine management

The Department of Environment and Science (DES) has published two new online reports outlining potential long-term management solutions for brine generated from coal seam gas (CSG) activities.

A DES information sheet was also released, documenting the background and context of the investigation into the potential long-term CSG brine management solutions.

Groundwater extracted as part of the CSG production process in Queensland varies in quality but is generally saline. Queensland Government policy is that CSG water should be beneficially used if feasible.

More than 90% of water generated from CSG activities in Queensland is treated and made available for a range of beneficial uses including for example irrigation, livestock watering and in construction activities.

Brine is currently being stored on an interim basis in dedicated storage ponds until a long-term disposal strategy is adopted. One of the challenges now being faced is how saline waste generated during the production of CSG, will be managed in the long-term.

A number of potential approaches to address the long-term management of brine have been investigated over the past decade but an industry wide solution has not yet been adopted.

DES will be working in collaboration with the Australian Petroleum Production and Exploration Association (APPEA) and its members, along with industry, landholder and environmental groups to develop an action plan for the long-term management of saline waste over the next twelve months. The two reports (see below) will help inform this work.

Background – APPEA Report

In December 2018, APPEA provided a report to DES titled ‘Queensland Gas: end-to-end water use, supply and management’.

The APPEA Report gives an overview of a number of feasibility studies that have been undertaken by industry operators individually or in collaboration with other industry operators.

These feasibility studies examined the viability of the identified options through a range of potential risks and impacts such as environmental, economic, safety, technical, regulatory and social factors.

The report summarises the findings of the following options examined by the studies:

• selective salt recovery
• injection
• ocean outfall
• encapsulation.

In summary, selective salt recovery was determined infeasible due to a lack of suitable technology at a commercial scale, high upfront and life cycle costs, significant energy consumption requirements and low excess demand in the current market.

The report concluded that the most viable industry-wide option for brine management at this time is the crystallisation and disposal of salt in purpose-built facilities.

Background – University of Queensland Centre for Natural Gas Report

DES then sought an independent review of the conclusions of the APPEA report by the University of Queensland Centre for Natural Gas (UQ).

UQ was requested to determine if all practicable options for brine management had been considered and provide comment on the feasibility of the identified options and conclusions. UQ provided DES with a number of conclusions and recommendations in the report titled Independent Review ‘Brine and salt management (Section 6, Queensland Gas: end-to-end water use, supply and management)’, dated 10 February 2020. A summary of the key conclusions and recommendations is below:

• Industry has reviewed all reasonable brine disposal options. No new options have emerged to make original investigation irrelevant or provide new avenues for investigation.
• Identified barriers to the implementation of selective salt recovery, ocean outfall and brine injection have been considered realistically.
• Disposal of crystallised salt in purpose-built SEFs is the most viable industry-wide option at this time.
• [If encapsulation is adopted] DES should develop guidance with respect to regulatory requirements during SEF construction, operation and management beyond the lifetime of the CSG industry. This should consider public reporting processes and residual risk management.
• Continued research and analysis of options for the long-term management of brine should be undertaken by DES and industry.

Next Steps

DES will be working with key stakeholder groups to progress consideration of a long-term solution for CSG brine. This includes working towards drafting an action plan over the next 12 months.

Key external stakeholders include representatives from industry, conservation and agriculture sectors and well as landholder groups.

The draft Action Plan is anticipated to consist of a number of brief sections that outline topics and outcomes for an industry-wide brine management approach. The Action Plan may address topics such as the proposed approach to brine management, regulatory requirements, environmental authority conditions, assessment framework, compliance activities and future activities.

Stakeholders will have a number of opportunities to review materials, participate in workshops (virtual and/or face-to-face) and make submissions.