Managing wastewater sustainably in the NT
Communities have concerns about the potential impacts on water from onshore gas development activities. In the Northern Territory’s Beetaloo Sub-basin, proposed future shale gas production is likely to produce large volumes of wastewaters. There are three main sources of shale gas water, namely flowback water (the return of hydraulic fracturing fluids after being injected into the well), well-drilling muds (used to lubricate and cool the drill bit) and produced water (water released from the geological formation during the drilling procedure). There will be a need to manage (store, treat and reuse) these wastewaters at proposed gas production sites.
To better understand options for wastewater management, CSIRO researchers first engaged with relevant industry, government and community groups to assist in incorporating the relevant social, environmental and economic criteria into the framework. The researchers identified both the quantity and quality of water expected at each stage of shale gas production in the Beetaloo. They reviewed the available data on appraisal well water quality from shale gas wells in the region and, also, the feasibility and proximity of production to those industries (such as mining, construction and agriculture) that could be potential users of reuse wastewater.
CSIRO researchers were then able to identify relative strengths and weaknesses of water management options that could be used for proposed shale gas operations in the Beetaloo Sub-basin. They developed an NT-specific framework for decision makers to understand future wastewater treatment and reuse options. The research showed many available management options, for example evaporation ponds and the use of membranes, although no single solution was found. The best fit-for-purpose process will depend on aspects such as the specific contaminants, energy needs, on-site treatment and reuse options etc.
Given Australia is a dry continent, there is considerable competition for water. The outcomes of this research will help improve the awareness and understanding of suitable options for water management following any shale gas production in the NT. The framework will provide a method to optimise wastewater options according to environmental, social and economic objectives, with benefits to local communities, regional industries and the environment.
For more information about this study, visit the research page for the project on the GISERA website.