Unconventional gas is a natural gas resource which require greater than industry-standard levels of technology or investment to harvest. The three most common types of unconventional gas resources are tight sands, coalbed methane (CBM), and gas shales.
The extraction of all forms of unconventional gas typically involves hydraulic fracturing or 'fracking', involving the pumping at high pressure, water and sand down the well. In the USA, chemicals such as benzene and hydrocarbons such as diesel are part of the mix. Groundwater has been contaminated wit hthese chemicals.
Fracking involves drilling to down to depth and often horizontally, and then injecting a slurry comprising water, sand and a cocktail of chemicals to fracture the shale deposits at intense pressure. The sand props open the fractures and, when the slurry is pumped back to the surface, natural gas – freed from pores in the fractured rock – flows.
In January 2010, the Environmental Working Group (EWG), a Washington, DC-based NGO, released a report stating that oil and gas companies were injecting petroleum distillates, including kerosene, mineral spirits and other petroleum products that often contain high levels of known human carcinogen benzene, into hydraulic-fracturing wells.
The report also cited research indicating that fracking – now used in 90 per cent of US natural gas wells – had been linked to drinking-water contamination and property damage in Colorado, Ohio, Pennsylvania, Wyoming and other states.
The level of concern is such that the United States Environmental Protection Authority is engaged in a study of the impacts of hydraulic fracturing on groundwater that is expected to provide an interim report in 2012 and final reports in 2014.
The Western Australian Department of Mines and Petroleum assures us that these chemicals have not been approved for use in Western Australia, but they are unable to tell us exactly what has been approved for use and how much of it has been used.
In June 2011, France banned fracking as a technique for extracting gas.
The WA government seems determined to push ahead with unconventional gas exploration and extraction, regardless of the growing level of public concern about the environmental impact of the 'fracking' process.
Before we even consider allowing fracking in WA, we need to carry out thorough independent research,tighten our regulations and make the entire regulatory process transparent to make sure this technology is safe and that surrounding groundwater is not contaminated.