Burke warned coal seam gas will deplete Great Artesian Basin

The Australian, Roseanne Barrett - 11.10.2010

TONY Burke is considering a report that warns the coal-seam gas industry could deplete groundwater in the Great Artesian Basin.

The federal Environment Minister is preparing to rule on several multi-billion-dollar projects and remains committed to a deadline of October 22, when he is expected to advise international energy giants Santos and BG Group whether he will grant environmental approvals for their projects converting coal-seam gas to liquefied natural gas, worth an estimated $22bn to the Queensland economy.

While the projects have been supported by the Queensland government, farmers and green groups have formed an alliance to call for a moratorium on the projects.

Their main concern is a potential depletion of the groundwater, something acknowledged by CSG companies in specific areas. Irrigators commissioned a report by the former technical adviser to the Great Artesian Basin Co-ordinating Council, John Hillier. It found there was an equilibrium between the Walloon Coal Measures — where CSG exploration is under way — and the Great Artesian Basin.

“There has been movement from the Walloon Coal Measures to the alluvium in the past, and with the decrease in pressure from the Walloons, this reversal of gradient must have an effect,” the report said.

Mr Burke said the department was “aware of the report by Dr Hiller and (has) considered that report in its advice to me. Water is one of many important issues considered in the assessment of these proposals. The department has sought expert advice on groundwater issues. I will take this into account when considering my final decision by October 22.”

Santos and BG Group have acknowledged their projects — which will extract 270 megalitres a day from the coal seam at their peak in 2014 — will have an impact on groundwater levels.

The Precipice Sandstone aquifer could drop as much as 15m, the Hutton Sandstone water table 3m and the Springbok Sands up to 5m, environmental impact statements acknowledge.

During the gas-extraction process, wells are drilled 300m to 600m below ground, pushing briny water and gas to the surface because of the pressure gradient.


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