REX MARTINICH
The Hamilton Spectator – August 08, 2015
WESTERN Victoria’s aquifers and surface water face a “low” risk from onshore unconventional gas fracking, according to a State Government report that has been harshly criticised by The Greens.
The report explored “hypothetical onshore natural gas development scenarios”, including a wide band of shale gas west of Casterton and three coal seam gas areas between Casterton, Merino and Dartmoor.
Another hypothetical coal seam gas field was modelled in the prime dairy region between Macarthur and Koroit.
Unconventional gas development involves, to varying degrees depending on the type of gas, the controversial extraction method of hydraulic fracturing or ‘fracking’.
Water, sand and chemicals are pumped underground at high pressure in order to ‘frack’ a gas well and the process has been depicted by activists as dangerous to the environment and human health.
Though the main body of the report presented unconventional gas as low risk, its introduction made candid statements about the proposed industry.
“Gas extraction depressurises the gas-bearing formation and may cause a decline in groundwater level, which could impact water users and ecosystems,” the report stated.
“Groundwater level decline may also cause land subsidence.
“Hydraulic fracturing can increase gas yield, but may unintentionally contaminate water supplies with hydraulic fracturing fluids and induce seismicity (earthquakes).”
Victorian Greens Leader Greg Barber has rejected a water table report’s main findings as “flawed” and accused the consulting company that produced it of having a commercial interest in seeing the fracking moratorium lifted.
“If the government is backing these findings, they seem to be saying that drilling in Western Victoria will be a lot lower risk than other places,” he said.
“I’m just not buying it.”
“There’s no actual evidence provided that the water table will only fall by 2 to 10 metres from gas drilling and extraction. All their other conclusions follow from that.
“That impact could be devastating enough to fragile farmlands and sensitive ecosystems, already stressed by drought and climate change.”
The Spectator has sought comment from Western Victoria Labor MP Gayle Tierney but she did not respond before publication deadline.
The ‘Otway region synthesis report: overview of the assessment of potential impacts on water resources’ was one of four submissions made by the Victorian Government for the State Parliament’s inquiry into unconventional gas.
The inquiry is due to report its findings to Parliament in December, and the recommendations could see the State Government lift or extend its current moratorium into most onshore gas exploration activities.
The water report stated that gas development in the Otways and Western Victoria would have a “low” impact on the water table with water flow changes and aquifer depressurisation “within historical ranges” and “the potential for chemical contamination of groundwater from hydraulic fracturing fluids is low”.
Lowan Nationals MP Emma Kealy repeated her party’s pledge to not approve any gas development that would pose a threat to agriculture.
“The Coalition has a strong history in unconventional gas, banning the use of dangerous BTEX chemicals, introducing the gas exploration moratorium, and commissioning extensive water and environmental studies and entering into a broad community consultation process,” she said.
“This is in stark contrast to Labor, who recklessly issued 72 gas exploration permits and 23 extraction licenses with no studies into the impact of fracking on our land, environment and water.
“This report forms just one of the submissions to (Parliament’s) Inquiry into Unconventional Gas. I await the final recommendations of the Inquiry with interest.”
The water report’s authors used test drilling results to estimate the water table impact of hypothetical shale and coal seam gas development in the Otways and Western Victoria regions.
Though much of south-west Victoria is covered by shale and tight gas exploration licences, The Spectator has only found one coal seam gas exploration licence that was granted in Western Victoria in previous years.
The private company that owned the licence, Mecrus Resources, “has ruled out CSG” according to a separate State Parliament report.
The current report found that “shale gas…is expected to exist in the Casterton Formation at depths greater than 2500m.”
“Prospective shale gas resources could be located near the South Australian border.”