A $350 million water treatment plant will be built on the Darling Downs to treat salty water brought to the surface as part of coal seam gas mining.
Multinational QGC (Queensland Gas Company) says the water treatment plant will have eventual production capacity of up to 100 megalitres a day and it will be treated and pumped from near the Kenya gas processing plant 20km to Chinchilla Weir for use in irrigation.
The company says it is “new” water but farmers say it’s extremely old water stored in the Great Artesian Basin and the impacts of its extraction are unknown.
“The water treatment facilities will benefit farmers, town residents and industry around Chinchilla,” QGC said in a statement.
“The facilities will treat water from the Walloon coal seams not usually used by local communities and will be a new water source that can be used as a substitute for water from the shallower, distressed aquifers currently used for agriculture.”
QGC Managing Director Catherine Tanna said the water is salty and would otherwise not be used.
“Our investment will make it possible to put this water to good use by treating it through leading-edge technology for use in agriculture and industry and it may supplement existing town supplies,” she said.
A QGC spokesman said the company is in discussions to find a use for 200 tonnes of salt per day.
“The aim is we find some sort of commercial grade use for it,” he said.
However, “as a very last resort”, the salt will be buried in government-approved and strictly controlled dumps if a commercial outlet cannot be found, he said.
AgForce policy director Drew Wagner said the water was coming from the Walloon coal measures underground aquifer, part of the Great Artesian Basin.
“If you start de-watering various aquifers in that basin, we don’t know what that inter-aquifer relationship’s going to be,” Mr Wagner said.
He said depressurising one aquifer will impact others but to what extent is uncertain.
He said the water supply touted by QGC will last only a few years and the problems of the waste stream, including large quantities of salt, were not resolved.
“They keep banging on about the virtues of this `new’ water to be utilised by landholders for food production, but the reality is that water will only be available for a short period of time and you can’t guarantee the volume,” Mr Wagner said.
Mr Wagner repeated AgForce’s calls for a moratorium on the CSG industry.
“This isn’t about us against them, it’s not about the agricultural sector trying to remove them from the landscape, it’s about balance and sustainability,” he said.
“We’ve called for a moratorium so all of us can take a deep breath, all of us stand back and use the scientific information we have to determine what that balance is.
“What if we’ve already gone past it?”
