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Environmental effects of fracking unclear
By Narelle Towie
CSIRO scientists have highlighted concerns that chemicals produced by hydraulic fracturing could be affecting ground and surface waters.
In a review published in CSIRO’s online Environmental Chemistry journal, researchers say fracking may be unlocking pollutants currently trapped safely in the ground and mixing them with substances injected by mining operations.
Review author and CSIRO chief research scientist Dr Graeme Batley says there is very little understanding of the chemical concentrations or what happens to them over time.
“To date there have been relatively few publications in the open scientific literature dealing with the environmental impacts of coal seam gas production and especially of fracking as well as geogenic [naturally occurring] contaminants, with most information contained in confidential reports to the service companies,” the review says.
“Although the industry is adapting where possible to more benign fracking chemicals there is still a lack of information on exposure to natural and added chemicals, and their fate and ecotoxicity in both the discharged produced and flow-back waters.”
Petrochemcials such as benzene, and naturally occurring metals and radioactive materials have been found in water produced as a result of fracking, according to the review.
“Geogenic contaminants mobilised from the coal seams during fracking may add to the mixture of chemicals with the potential to affect both ground and surface water quality,” Dr Batley states. Hydraulic fracturing, nicknamed fracking, involves blasting sand, chemicals and millions of litres of water underground to rupture rock and release ‘unconventional’ gas reserves.
The practice is controversial and fracking for coal seam gas has been blamed for depleting and contaminating groundwater and causing methane to leak up through farmland in Queensland and the US.
In WA, unconventional gas reserves consist mainly of shale and tight gas and are expected to secure the state’s energy needs as advances in engineering make the product more commercially viable.
Across the state, 46 wells have undergone 780 fracture stimulations across the Perth, Carnarvon, Canning and Bonaparte basins, according to the Department of Mines and Petroleum.
Monash University environmental engineer Dr Graham Mudd says more quantitative work needs to be done on the issue.
He says aside from a lack of data on the impacts of fracking chemicals on groundwater, there is a problem with how legislation controls the industry.
“At the end of the day, we’ve had multi-billion dollar projects go through Queensland and we still can’t get an accurate description of what is in [discharged] water, how it varies, what are the concentrations, how much chemicals have been put in and what has been the impact so far from existing coal seam gas operations—this is all stuff that an environmental assessment process should have dealt with and it hasn’t, and it has failed,” Dr Mudd says.
In July 2011, ScienceNetwork WA reported that a lack of legislation, which would force mining companies to carry out stress surveys before fracking, was putting WA groundwater at risk.
Then in November, a review by the State Government found legislation of unconventional gas industries was “adequate”.
Despite the review, Minister for Mines and Petroleum Norman Moore recently changed the law to require companies to publically disclose the chemicals they are injecting as part of the fracturing process.
The government maintains that fracking has been occurring in WA for more than 50 years with “no observed adverse consequences”.
Dr Batley says CSIRO research will further investigate environmental issues.
Industry representatives Australian Petroleum Production and Exploration Association did not respond about the CSIRO paper.