Reject brine (or concentrate) is the waste by-product of the desalination process, but it can also be generated from mine dewatering and agricultural drainage for salinity control. The handling of reject brine from these sources poses a major economic and environmental dilemma, especially in regions that depend on desalination for potable water. Inland desalination plants tend to be smaller than coastal installations, but their number is growing at a faster rate. Here, brine disposal into natural ecosystems is frequently considered the only economically viable means of disposal, especially for produced mine water and saline land drainage. In such situations, the prevention of unacceptable impacts on receiving systems requires an understanding of the critical thresholds in ecosystem response to brine discharge and the interaction with multiple stressors that influence the state of the system.
Using an ecosystem services approach to the management of brine offers a means of accounting for the costs of environmental impacts as well as the potential gains from beneficial uses and enhanced ecosystem services. The approach conforms to processes at the national and international levels. However, these are not yet made explicit in water quality guidelines or environmental management best practice. There is a need to develop policies and practices for maintaining or enhancing ecosystem services, particularly for the arid and semi-arid regions of Australia where fresh water is a scarce commodity and in regions suffering from the effects of secondary salinisation.
Review current ‘best practices’ in relation to the management of brine from various sources, focusing on an inland Australia. Determine the links between different brine management options (disposal and beneficial uses) with ecosystem responses and ecosystem services, with a view to providing more site-specific applications and recommendations for regulatory reforms.
The study was built on three assumptions: i) an ecological understanding of ecosystem services is essential for human development; ii) protocols and guidelines for management (including brine discharge) need to be derived from these understandings; and iii) both industry and society can derive benefits from the brine, or from its appropriate management, in inland ecosystems.
The Guidelines (link below) present a review of current ‘best practices’ in relation to the management of brine from various sources, focusing on an inland Australian context. What differentiates this document from other similar reviews and guidelines is the attempt to explicitly link different brine management options (disposal and beneficial uses) with ecosystem responses and ecosystem services, with a view that this may feed into more site specific applications and hopefully also set the scene for discussions on necessary regulatory reforms.
The many compartments of ecosystems that are potential receiving environments for brine offer a multitude of services that, if lost or degraded, would incur serious social and economic costs. An ecosystem services framework offers a means of incorporating these externalities, both the negative and positive ones, into the cost-benefit analysis of brine management. For this to work, however, decision makers at all levels should endeavour to assess and communicate the role of biodiversity and ecosystem services in economic activity and for human well-being.
One issue is that to-date, brine ‘management’ in Australia has generally amounted to ‘disposal’. Unfortunately, most disposal options tend to have adverse environmental impacts, including on source waters. Given the ever growing demand for, and increasing scarcity of, fresh water resources, direct disposal of brine is increasingly being regarded as loss of a resource. An important prerequisite for sustainable brine management in inland Australia is a paradigm shift from treating brine as a waste product to treating it as a resource – while nevertheless still adhering to sound waste management principles (i.e. minimisation, reuse, recycle). There remain, however, a number of stumbling blocks and associated needs before this can be universally adopted.
Recommendations and Future Direction
Several recommendations were made from this study:
- Continue investment in breakthrough and innovative technologies for brine treatment and minimisation; this should be specifically focused on Australian conditions.
- Site-specific feasibility studies for brine management, including minimisation and beneficial uses; in particular, identifying opportunities for involving dedicated third parties in brine management. This would help to overcome industry sentiments that beneficial uses are outside of the core business of operations.
- Further detailed investigation of the socio-political aspects of brine disposal in inland areas, for example, identifying employment opportunities.
- Further analysis of regulatory reforms required to ensure sustainable brine management, including addressing inconsistencies and implementing standardised approaches between states and territories, and between different brine-producing sectors. This would ideally also include an economic-political assessment of potentially feasible market-based instruments and development of an ecosystem services framework.
Feedback on the Guidelines (link below) is sought and the intention is to update the information to maintain its relevance.
Total Value: $1,278,969 (cash and in-kind contributions)
Principal Investigator: Professor Ray Froend
Title: Management of brine disposal into inland ecosystems
Length: 37 months
Personnel: 7 collaborators contributing 4.0 FTE
- 2014. A Guide for the Management of Brine in Inland Areas: an Australian perspective (The Guidelines).
- 2013. NCEDA International Desalination Workshop. Melbourne, Australia.