THE shifting-nature of the Liverpool Plain's black soil makes it an "impractical" place for a gas pipeline, a report has revealed.
It the latest in a raft of concerns farmers have raised about the proposed $1-billion Queensland-Hunter Gas Pipeline.
In 2015, an independent report was prepared by SoilFutures Consulting for the now defunct Eastern Star Gas Narrabri-to-Wellington pipeline, which was proposed to run through the Liverpool Plains.
It revealed the shrink and swell properties for the vertosols - cracking clay soils - on the Liverpool Plains were "among the highest in the world", with some cracks reaching a depth of up to six metres.
"[The plains have] highly expansive soils, which will lead to any pipeline placement with in the expansive zone of the soils having a high risk of failure," the report states.
The extensive report concluded it was "clearly impractical to place a safe and stable gas pipeline" in the Liverpool Plains.
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The pipeline was first approved in 2008, and it was granted a five-year extension by the state government at end of last year.
However, there has been no correspondence between landholders and company behind the project, Queensland Hunter Pipeline, during that time, leading farmers to believe the project had lapsed.
Easement agreements have yet to be reached, so the proposed pipeline does not appear in any title searches and many new landholders are only just learning the pipeline goes through valuable irrigation land.
At a recent meeting in Quirindi, more than 100 farmers gathered to discuss their concerns about the project.
The town's water supply, and that of many farmers, could be at risk, with the pipeline running below the Borambil Creek, into its recharge aquifer.
In recent correspondence between Queensland Hunter Pipeline chief executive Garbis Simonian and a local landholder, Mr Garbis said the "pipe diameter will most likely be 24 inches [600mm]".
But the pipeline's approval documents state it will "have a diameter of approximately 500mm".