Mystery of gas bubbles in Condamine River still murky
TWO years after gas seeps were discovered bubbling in the Condamine River, Australia Pacific LNG can not confirm their cause.
The gas company's Condamine River Gas Seep Investigation: Technical Report was released today, and although it did not pinpoint a definite cause for the seeps it found no evidence of environmental or safety risks.
The report was independently reviewed and verified by the Queensland Government's Chief Scientist Dr Geoff Garrett who recommended ongoing monitoring of the seeps and further investigation into their cause.
Potential causes for the seeps outlined in the technical report included depressurisation, repressurisation, fractures, faults and springs and the capping and trapping of natural gas.
Lock the Gate Alliance president Drew Hutton said it was the depressurisation possibility from the "narrowly focused" report that should ring alarm bells.
"That's important as it indicates that there are pathways from the coal seam to the surface," he said.
"The key thing is that the activities of the CSG industry are depressurising the coal seam aquifer and that makes way for methane and other dangerous gases to be released into the atmosphere."
Origin Group Manager, Exploration, Appraisal and Development, Ross Evans, said a detailed analysis found no evidence of contribution to the seeps from Origin's CSG wells in the area.
Mr Evans said he was pleased with Origin's progress in investigating the seeps and their cause.
"We've been very busy over that period [since 2012] doing an enormous amount of monitoring and studying," he said,
"In terms of progress, we've certainly narrowed the field down."
Australia Pacific LNG has now constructed six of eight monitoring bores at four locations near the seeps.
These monitoring bores feature real time telemetry data systems and will provide ongoing data on ground water levels and pressures.
Origin Chief Executive Officer LNG, David Baldwin said detailed investigation into the Condamine River seeps had greatly increased understanding of subsurface conditions.
"Despite there being very little CSG development in the immediate area, the responsible approach is to develop and maintain an ongoing monitoring," he said.