New research from the United States reporting that a steep rise in earthquakes across the central US
is likely to be man-made as a result of 'fracking' coal seam gas will do nothing to reassure Australians regarding the environmental safety of this method of gas extraction. The US Geological Survey found a sixfold increase in seismic activity was
particularly common in regions where waste water from fracking was injected
into deep wells. Similar findings were made in the United Kingdom last year, where experts found it ''highly probable'' that fracking was the
cause of 50 seismic events near Blackpool. This finding has been reaffirmed again this year, thus underlining the lack of sound research knowledge and information on this mining method.
CSG occurs in coal seams being predominantly methane
(CH4) but other gases may also be carbon dioxide (CO2), carbon monoxide (CO) and nitrogen. As water
usually saturates these seams, the CSG is extracted through the drilling of wells
into the coal, pumping the water out, thus releasing pressure to enable the
gas to be collected. Released gas is pushed by compressors to a central gas
processing facility then compressed/dried for transportation. CSG has risks for
negative environmental impact through:
- Large
amounts of water by-product due to pumping from the coal seams and risk of arsenic contamination;
- The
use of hydraulic fracturing (‘fracking’) in the production process (if the gas
is tightly held) with possible effects on surface and ground water systems. Fracking
uses carcinogenic/toxic BTEX group chemicals/fluids (ie benzene, toluene, etc).
- The
potential leakage of methane gas during production and transportation (CH4 is a potent GHG gas if released).
CSG has alll the elements of a last ditch, desperate effort to locate new fossil fuel sources and should be seen in that light. It does not present a new safe form of energy nor at this time is it a safe intermediate energy source pending the uptake of greater renewable energy production.