AGL (formerly Lucas and Molopo companies) has exploration licences covering the whole Gloucester Coal measure area, 1050 sq km, and has recently announced the flows are such that they are now seeking approval to go into full production of Stage 1. This involves connecting the underground drill holes which go several hundred metres deep, possibly through aquifers.
Approval for a pipeline to be constructed from Gloucester to Newcastle is also being sought. The Environmental Impact study (EIS) is currently before the NSW State government for approval. The public exhibition of the EIS has been delayed with a date for public viewing to be announced. Initial land surface disruption is less than that of open cut coal mining, but the potential for serious pollution and destruction of underground and surface water is considerable (see left). There have been examples of this type of damage from methane extraction in NSW and elsewhere.
Your BGSP-Alliance representative on the AGL Community Consultative Committee (CCC) is Garry Smith. If you have any concerns or need further information please contact Garry through
bgsp-alliance@yahoo.com.au
Photos on this page: The consequences of methane escapes in Pilliga, NSW.
THE GAS STORY...
Methane gas extraction is seen by some local citizens as a relatively benign activity. We have been able to gather some information from gas extraction sites elsewhere in NSW and in other countries using similar technology.
Coal is quite porous and methane is usually found in the minute cavities. Coal seams have to be penetrated by drilling. Sometimes the coal seams are fractured to help in the process of releasing the gas. When there is a good supply of gas, the coal bed needs to be tapped with multiple drillings. Water is used in a number of ways and this water can be mineralised to the point that makes it unsuitable for agricultural uses on the surface.The gas, if released into the surrounding country, or if it flows uncontrolled through the fractured coal seam and surrounding rocks, is toxic and quite dangerous. In order to reach the underground coal seams, miners must drill down through the underground water table upon which surface vegetation and rural activity depends.
The situation could be briefly sumarised as follows:
* Impacts on the surface of the land, during the exploration period, seems modest compared to the excavation by coal and ruby mining.
* If multiple wells are later developed, the impact becomes much more intrusive.
* If the drilling brings saline or otherwise mineralised water to the water table or to the surface, then this can prejudice local water supplies. Holding dams have, in other places, allowed seepage into local water supplies and have been breached because of poor maintenance or when storm water has caused overflows.
* Drill holes are usually lined with concrete, but shifts in the strata can fracture this precaution, releasing gas or contaminated water. The following report by C.M.Atkinson, geologist, was printed by The Australian Gas Alliance. It refers to a methane gas escape in the Gloucester Basin. “In September 2004, within a fortnight of the beginning of gas testing, a coalbed methane well north of Newcastle, NSW, was shut down as several boreholes up to 300m away began to blow off methane gas.”
“In this case there were apparently no serious injuries and the methane gas migrated into nearby boreholes rather than houses, essential water supplies or livestock areas. This example shows that even with only a partial withdrawal of the hydrostatic pressure methane will migrate quickly and in unpredictable directions.”
* Photographs available show the consequences of methane escapes in Pilliga, NSW. Geologists reports are published by the Australian Gas Alliance, which successfully campaigned against gas mining in the NSW central coast.
* Clearly, government guidelines are laid down, but we cannot be reassured by the fact that we are being expected to allow mining to go ahead, so only when the disaster occurrs can we know about the dangers.