The brackish water extracted from the coal seams is treated to very high standards to make it suitable for use in agriculture, groundwater systems and environmental flow enhancement.
Reverse Osmosis (RO) treatment facilities have been constructed at Spring Gully, Talinga, Condabri and Reedy Creek using cutting-edge water management and treatment technology to purify and desalinate up to 112 megalitres (million litres) of water each day. Treated water produced from the Talinga and Condabri water treatment facilities is provided for irrigation and livestock drinking water via the Fairymeadow Road Irrigation Pipeline scheme, near Miles.
The high quality water provided meets recognised irrigation and stock water standards for beneficial agricultural use (ANZECC Guidelines). Routine water sampling and plant safeguards are in place to provide assurance that all water supplied under the scheme meets these standards.
The diagram shows where the coal seams are typically positioned relative to the commonly used aquifers.
The salt that is removed from the CSG water during treatment to make it suitable for beneficial use forms part of a residual solution known as brine. The brine is contained in fully-lined dams that are subject to strict construction regulations to prevent it from entering the surrounding environment. This stored brine is further concentrated through thermal processes prior to forming salt crystals which are suitable for disposal in encapsulation facilities.
All existing research and experience in producing CSG over the past 10 years, along with computer modeling, shows that CSG production is likely to have negligible impacts on the most commonly used water supply aquifers.
Our modelling has been subject to comprehensive reviews by both state and federal regulatory agencies. Decisions about groundwater management will be guided by modelling, but any action taken will be based on monitoring results. Together with other participants in the CSG industry, we work with the Federal Office of Groundwater Impact Assessment in the development of an independent cumulative regional groundwater model. Their first Underground Water Impact Report (UWIR) was released in December 2012, and the second was released in 2016. The latest UWIR with associated updated modeling, was released in November 2019.
We undertake extensive groundwater monitoring throughout the entire duration of our operations, monitoring water levels and quality in the most commonly used aquifers as well as geological layers not generally accessed for groundwater. We monitor for pressure and water quality changes in the geological layers above and below the coal seams. This early detection monitoring is designed to provide Australia Pacific LNG with sufficient time to implement appropriate mitigation strategies.
The monitoring program is undertaken at both local and regional scales. Local programs focus on the existing operational gas fields at Talinga and Reedy Creek to gather data and improve the understanding of potential risk and adapt monitoring if necessary. Regional monitoring extends across the full extent of Australia Pacific LNG/Origin CSG tenements, and is undertaken in partnership with the other CSG tenure holders across their leases to provide comprehensive and seamless coverage.
Make Good Agreements
If CSG-related impacts on groundwater are predicted or detected,we will mitigate these impacts and ‘make good’ as required by the Water Act 2000 (Qld). This means that ‘make good’ requirements must be assessed and negotiated with potentially impacted landholders.
Actions could include increasing the depth of landholder bores,sinking new bores for the impacted landholder,lowering,modifying or replacing pumping equipment or supplying treated CSG water to supplement landholder supplies.Decisions on the appropriate course of action will be made on a case-by-case basis.