AGL acknowledges that both surface and groundwater resource protection is a key issue for the Gloucester community. AGL believes it is critical to protect water resources and manage produced water as part of the sustainable development of coal seam gas.
An extensive water monitoring network has been installed across the Gloucester area and as at December 2013 includes:
- Forty two (42) groundwater monitoring bores installed with dataloggers to record water levels
- Five (5) stream gauges installed with dataloggers recording salinity and water levels (surface water), and five dam monitoring locations
- Two (2) shallow gas monitoring bores
- Two (2) seepage monitoring bores to detect any seepage from the Tiedman produced water dams.
Groundwater investigations for the Gloucester Gas Project are well advanced. The investigation studies that are completed and ongoing comprise the following phases:
- Phase 1: Desktop study (completed)
- Phase 2: Detailed groundwater investigations and Stage 1 network (completed)
- Phase 3: Numerical models (commenced)
- Phase 4: Monitoring programs - Stage 1 and beyond (ongoing)
- Phase 5: Additional investigations - Stage 1 and beyond (commenced)
Phase 1: Desktop Study (completed)
The Phase 1 desktop study is a review of existing information to develop an initial understanding of the hydrogeological characteristics of the area.
View all Phase 1 reports under Water Reports.
Phase 2: Detailed groundwater investigations (completed)
AGL has been investigating groundwater and surface water conditions within the Stage 1 Gas Field Development Area since December 2010.
The studies involve geological appraisals, drilling, permeability testing, water level monitoring, water quality sampling, isotope studies, data collation, analysis and reporting.
In addition, the study was designed to help AGL and the community better understand the groundwater in the project area and what affects, if any, there might be on the groundwater from natural gas exploration.
The Phase 2 detailed groundwater reports can be found under Water Reports.
Phase 3: Numerical model (commenced)
Now that AGL has more than three years of water monitoring data, and has completed more Stage 1 and basinwide investigations, numerical modelling of the Gloucester Gas Project has commenced.
Numerical modelling is converting the current conceptual groundwater flow model into two and three dimensional representations of the geology and hydrogeology. Modelling allows the drawdown effects of different wellfield layouts and different development scenarios to be predicted. Likely water production volumes can be estimated together with the refinement of the current water balance for the Gloucester Basin.
These studies will help AGL with its water production estimates, and allow the community to better understand what affects, if any, there might be on groundwater and surface water resources from the Stage 1 field development.
Phase 4: Monitoring program (ongoing)
AGL's water monitoring program describes the water level and water quality results from its extensive monitoring network. The basin-wide monitoring network is shown here. Interpreted monitoring reports are released annually around September each year for the previous water year.
View all water level and water quality reports under Water Reports.
The hydrogeological studies conducted to date have shown that there is no evidence of natural connectivity between shallow and deep groundwater systems.
Phase 5: Additional investigations (commenced)
AGL has commenced additional investigations that expand on our detailed groundwater investigations and monitoring programs. Read the reports under Water Reports in the document library.
AGL Upstream Gas, as part of its CSG exploration and production programs in NSW and QLD, commissioned a desktop study on the occurrence of naturally occurring hydrocarbons in groundwater from Permian coals measures and associated sedimentary rocks. The report prepared by CSIRO and Earth Science and Resource Engineering - Petroleum and Geothermal Research Portfolio Group concluded that most of the detected total petroleum hydrocarbons, PAH (polycyclic aromatic hydrocarbons) and BTEX (benzene, toluene, ethyl benzene and xylenes) compounds appear to be naturally occurring.
Typical Bore Licences for the Gloucester Gas Project
AGL is required to hold bore licences from the NSW Office of Water for its exploration and groundwater monitoring activities that involve drilling and taking groundwater from bores/wells or monitoring groundwater associated with the local groundwater systems of the Gloucester Basin. The following are typical of the 40+ bore licences that AGL holds for the current CSG exploration activities: