Respected water expert Dr Richard Cresswell has reaffirmed that Santos’ proposed Narrabri Gas Project will not impact the major recharge zones of the Great Artesian Basin.
In a short video released by Santos today, Dr Cresswell, former CSIRO hydrogeologist, said the area in which the Narrabri Gas Project is located, is a “very low recharge area”.
“The main recharge areas in the region around Narrabri for the GAB are in the Warrumbungles to the south and from the Namoi River alluvium system to the north,” Dr Cresswell said.
“The area around where the gas project is, is in fact is a very low recharge area.
“The water in the GAB comes from rainfall falling on the recharge zones all around the margins.”
Dr Cresswell said the water Santos will extract is not from the GAB and the local geology will prevent the waters in the GAB from being impacted.
“They are not Great Artesian Basin waters, they are from the Gunnedah Basin, beneath the GAB and it is isolated from the GAB by some very fine grain sediments which do not allow water to go up or down between those two basins,” Dr Cresswell said.
“A farmer’s water would not be impacted by any of the drilling that goes through the Great Artesian Basin to get to the gas.”
Dr Cresswell also highlighted the stringent regulations that an energy company must abide by while extracting natural gas, to ensure water resources are protected.
“When a farmer is putting a bore down for water, they are drilling under the provisions of the water act. When a gas company is putting down almost exactly the same bore to get the gas, they are drilling under the provisions of the petroleum act and under that act they have much more strict and stringent requirements for the quality of that bore and the protection of all the rocks that it goes through,” Dr Cresswell said.
“A gas company seals the top area with concrete, then puts a second concrete seal down through any of the groundwater sources and then they drill another tube down through the middle of that so there is at least three levels of protection of any water supplies in the rocks that its going through.”
Facts about the GAB
· It underlies about 1.7 million square km of Australia – or about 1/5 of the continent
· It is comprised of many different types of sediments including sandstones, siltstones and mudstones that have been laid down in layers over millions of years
· The layers of the GAB are then wrinkled, morphed and tilted over time so the eastern side is slightly higher than the western side.
· There are four sub basins to the Great Artesian Basin and each is isolated hydrogeologically so the groundwater in one basin does not flow into any of the other basins.