NSW Government is pushing a plan for miners and gas producers to pump unwanted wastewater into aquifers, but the same technique has coincided with an alarming increase in earthquake activity in the US.
The scheme would provide resources companies with a monetary rebate for water pumped back into an aquifer after had been extracted during either mineral or gas production.
Water Minister Niall Blair confirmed the scheme was still under development and the Department reported consultation would be undertaken before the plan progressed.
Aquifer reinjection has been widely deployed by gas and shale oil producers across the US, with a whopping 30,000 water disposal wells sunk to date.
In March, the Federation of American Scientists investigated the impacts of aquifer reinjection and reported the technique could be behind the rapid increase in seismic activity in eastern and central states.
The report, titled Human-Induced Earthquakes from Deep-Well Injection, found earthquakes of magnitude 3.0 or greater had increased threefold since 2009.
Submitted in May to the US Government's Congressional Research Service, the Federation found that on average, there were 29 earthquakes greater then 3.0 magnitude a year between 1970 and 2000.
But between 2010 and 2013 that figure rose to more than 100 a year.
The rate of earthquakes with a magnitude of 3.0 or more in central Oklahoma increased by 50 per cent between October 2013 and May 2014. Some destroyed buildings.
Mr Blair said aquifer reinjection required careful consideration and consultation with stakeholders.
State environment laws would require any aquifer reinjection to operate in full compliance with current standards.
NSW Chief Scientist Mary O'Kane, in her 2014 report on coal seam gas, noted seismic activity could occur from aquifer reinjection - but added technical controls existed to manage those risks.
However, US Geological Survey senior advisor for earthquakes William Leith noted in the more recent Congressional research report that groundwater systems were still not understood well.
"Scientists currently have limited capability to predict human-caused earthquakes for a number of reasons, including uncertainty in knowing the state of stress in the earth, rudimentary knowledge of how injected fluids flow underground after injection, poor knowledge of faults that could potentially slip and cause earthquakes," Dr Leith said.
NSW Farmers slammed the move.
"We don't support the government's potential plan to let extractive industries reinject water, let alone be given financial credit for reinjecting that water back into the aquifers," a spokesman said.
"There is not enough rigour around accounting for water impacts.
"Governments have a responsibility to be open and transparent on (such important) issues."
Mike Foley
Senior journalist for The Land.
Senior journalist for The Land.
