Chris Dobney and Melissa Hargraves
The coal-seam gas industry could face a troubled future if it can be proven that it is causing methane leakages into the landscape, according to two Southern Cross University researchers who presented their findings last night.
Methane is a greenhouse gas 20 times more potent than carbon dioxide and gas companies could face massive carbon-tax charges if fugitive atmospheric emissions were proven.
Drs Isaac Santos and Damien Maher used high-tech equipment to monitor methane levels and to fingerprint the methane isotopes of gas in Tara, Queensland, and the Richmond Valley. They were then able to determine whether it was either part of the natural cycle (eg from swamps or grazing animals) or was from underground sources.
The team established that methane was up to three times more prevalent in the environment around Tara than in the Richmond valley, where CSG production has yet to commence.
They recorded methane levels in CSG areas as high as 6.89 parts per million compared to other non-CSG areas that recorded levels around two parts per million.
Dr Santos also disclosed the testing results of the Condamine methane bubbles as ‘having the same fingerprint as the methane from extraction… which has a different composition than what occurs naturally’.
‘This throws the industry into a whole new light,’ according to Lock the Gate Alliance president Drew Hutton.
‘The federal government currently works on the assumption that fugitive methane emissions from coal seam gas are 0.12 per cent of all gas produced,’ he told media this morning.
However, he said, if methane levels are ‘many times higher’ – as the study suggests – than the industry could face higher penalties under the carbon tax.
While the tax implications of this greenhouse gas are evident, the researchers pointed to the fact that there are no baseline data, other than their research, currently available against which to compare future readings.
Dr Maher said the team was putting together ‘cutting-edge atmospheric models to try to calculate how much gas must be escaping’.
‘Currently NSW and QLD [only] have a code of practice for wellhead emissions, which relate to how explosive the wellhead is. For a wellhead leak to be reported, the methane concentration needs to reach 5,300 parts per million, compared to 1.8 which is natural in the atmosphere.
‘It is like we have a fire alarm instead of a smoke alarm.’
Dr Santos, whose area of speciality is groundwater, says he ‘doesn’t like to exaggerate but we have heard of examples in Tara where the groundwater has dropped by 100 metres!’
The team also measured for the amount of groundwater present in rivers and streams, based on the amount of radon, a naturally occurring radioactive gas, traces of which are present in any water or gas that is moving underground.
Dr Santos explained that ‘radon is much higher in groundwater than surface water’.
By mapping radon concentrations, Dr Santos believes that you can determine where groundwater is entering the creek.
‘I would be advising the CSG mining companies to drill in areas where there are low concentrations of radon as we know that groundwater is not feeding those areas.’
Interestingly, high levels of radon were detected in five creeks across the Richmond catchment by students of Dr Santos, so they are being fed by groundwater.
‘This is the kind of information we need so we can see what happens after major development,’ said Dr Santos.