There is significant interest in the development of a liquefied natural gas (LNG) sector in Queensland based on processing coal seam gas (CSG). As the CSG-LNG sector presents both opportunities and challenges, the Queensland Government is conducting a review to help shape its policy response.

What are aquifers and are they connected?

An aquifer is a geological underground formation that holds a usable quantity of water within either a sand, gravel, sandstone or limestone mix.

There are three forms of aquifers:

• unconfined
• confined (artesian)
• perched.

An unconfined aquifer is a body of water than extends from the surface to an impermeable rock layer. A confined aquifer is a body of water located below, and separate from, the surface water table. A perched aquifer is a body of water created by rain entering the ground and pooling to form a spring.

Aquifers generally are not interconnected, however, some migration of water can occur. The extent of the interconnection of the aquifers associated with the LNG projects is being examined to determine if CSG production could cause any environmental impacts to the aquifers.

Will aquifers be affected by CSG production?

The Queensland Government has commissioned a study of the potential groundwater impacts resulting from the expansion of the CSG sector. It is possible that CSG water extraction may reduce groundwater levels within important aquifer systems surrounding to the coal seam beds, including aquifers within the Great Artesian Basin. It is uncertain how long this effect would exist.

The commissioned study will:

• describe the potential impacts of CSG water extraction on the Surat and Bowen basins and surrounding aquifers
• propose an approach for regional and local monitoring of the impacts of CSG water extraction on surrounding aquifers
• examine the local and regional hydro-geological relationship between coal seams and surrounding aquifers in the Surat and Bowen basins
• estimate the quantity, quality and distribution of CSG water.

How are Queensland’s groundwater resources being managed?

The majority of Queensland’s groundwater resources are administered by the Department of Natural Resources and Water (NRW) as water resource plans under  the Water Resources Act 2000. There are currently 21 such plans in operation covering more than 90 per cent of the state’s water catchment areas.

Groundwater resources that are not covered by a water resource plan are administered either by a formal arrangement between NRW, the local council and the company involved, or the Wild Rivers Act 2005.  

Contact the LNG projects team

tel:        +61 7 3404 8206
email:    lng.team@dip.qld.gov.au
post :    LNG Industry Unit
Department of Infrastructure and Planning
PO Box 15009, Brisbane City East QLD 4002

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Impacts of coal seam gas on groundwater aquifers   44 KB