Review of potential environmental impacts of shale gas related wastewater disposal options

A component of shale gas development is the production of wastewater, primarily from used drilling fluids and flowback from hydraulic fracturing activities. How this wastewater is managed, with a particular focus on potential environmental impacts, is an issue that continues to be of concern to communities in the Beetaloo region of the Northern Territory (NT).

This project will assess wastewater management and treatment options, including associated waste disposal requirements, and their potential for environmental harm. The project’s focus will be on wastewater derived from drilling, hydraulic fracturing and flowback activities associated with shale gas development. Wastewater from other industries will also be considered to provide additional context.

A significant component of this project will look at approaches to reduce the volume of wastewater and waste to be managed. These approaches include reuse of untreated residual drilling, hydraulic fracturing and flowback fluids in shale gas activities. The project will place an emphasis on evaluating the potential impacts of the reinjection of wastewater into deep formations.

Wastewater reinjection, though widely used in other jurisdictions is prohibited in the Northern Territory in response to a recommendation from the Independent Scientific Inquiry into Hydraulic Fracturing of Onshore Unconventional Reservoirs in the Northern Territory. This recommendation was based on the uncertainty around potential impacts and indicated that wastewater reinjection may be permitted if the risks could be managed.

The ultimate disposal of residual wastewater or the waste materials that result from wastewater treatment will be included in the assessment. The results of this project will be a comparison of the relative potential environmental impacts of the options considered, how those impacts are mitigated elsewhere, along with the level uncertainty.

This information may be used to inform the community, industry and regulators about future approaches to wastewater management from shale gas development.