Residents of a Queensland town being tested for noxious soil gases say they want scientific proof that coal seam gas mining in the area is not to blame.
Gases were detected in soil on private properties at Hopeland, about 300km west of Brisbane, late last month. The Department of Environment and Heritage Protection has not ruled out an underground fire as testing continues to find the cause.
"EHP is working hard on a range of techniques and sampling, such as thermal imagery and micro seismic testing, to narrow down the potential causes," a spokesman said.
The EHP has also carried out water testing in the Condamine River and Chinchilla weir, but says the results were within the expected range. Preliminary air quality tests were also within guidelines, but more testing is still being done.
It says there is no risk to human health, and that effects on grazing animal and stock are "very unlikely".
However, Hopeland residents, who now have to contact the EHP before carrying out excavation works, are not convinced. They say they believe coal seam gas mining in the area is to blame, despite assurances from the government that it is not.
"One of our questions is what is the science behind you categorically saying that CSG is not complicit or contributing to this problem?" said Shay Dougall, from the Hopeland Community Sustainability Group.
She said the EHP had agreed to meet community members about the gas testing but had not yet set a date to do so.