The following is a speech by Mallaley farmer, Margaret Fleck, delivered at the recent Back the Gomeroi against Santos Rally and Road Trip at Coonabarabran and Narrabri.
To extract the gas Santos has to remove the water to reduce the pressure to allow the gas to flow. Having been buried in the coals seam for a very long time the water contains significant levels of boron, fluoride, heavy metals, and in some places radionuclides like radium and uranium.
To get to the coal seams the gas company has to drill through a crucial recharge zone of the Great Artesian Basin and through rock layers to get to the coal seams.
The process starts with clearing an area around the well of about 100 metres x 100 metres,
clearing of 12-metre-wide interconnecting corridors for roads and the installation of water and gas gathering pipework with high point vents and low point drains.
The drilling process involves the use of what is usually referred to ‘drilling mud’ or ‘drilling fluid’. These are water-based fluids used in the drilling process to cool and lubricate the drill bit, and also to carry drill cuttings to the surface. A lot of chemical compounds are added:
Common additives include, weighting material, corrosion inhibitors, gelling agents, viscosifiers, biocides and defoamers. For example, Tetrahydro-3,5-dimethyl-1,3,5-thidiazine-2-thione is a soil sterilant.
Some of the drilling fluid remains down the well and of the drilling fluid brought to the surface with the drill cuttings about about 90% of the drilling fluid is recovered for reuse. Santos has approval to use a mix, turn, bury strategy which means that for each well about 100 cubic metres drill cuttings of which about 10% will be drilling fluid will be mixed into the soil at each well pad.
Once the coal seams have been drilled the toxic water which now has gas flowing through it is brought to the surface to be separated. Initially these wells produce millions of litres of water and that causes huge problems for the environment. Once brought to the surface it is placed in large holding ponds. The water is so toxic that if the ponds leak or overflow it causes contamination and results in death of vegetation.
Bibblewindi where there are large water holding ponds there have been a number of spills and leaks.
- spill example – Bibblewindi (pump stop failure) – 1.8 hectare of vegetation killed by 10,000 litres. This equates to less than one millimetre in depth if spread evenly over the kill zone.
- leak example – Bibblewindi pond number 3 with a holding capacity of 170 megalitres had a damaged liner and leaked, contaminating aquifers below the pond.
If the Narrabri Gas Project were to proceed up to 37 gigalitres of toxic water will be removed from the coal seams. To visualise that amount of water it represents a tower measuring 100 metres by 100 metres at the ground and 3.7 kilometres high.
Unlike conventional gas with one or very few gas wells, coal seam gas extraction needs a very large number of wells closely spaced.
Environmental Impacts
The Pilliga Forest constitute an important refuge area for wildlife, containing high conservation-value small remnant patches, which are part of a recognised National Biodiversity Hotspot with endemic species and high levels of ongoing threat, whose irreplaceability is of the highest order.
The threat and serious and irreversible harm is clear.
The installation and operation of the coal seam gas wells would result in the following detrimental impacts:
- Increased fragmentation of a landscape already under severe environmental stress;
- increased sedimentation of ephemeral waterways and the reduced availability of surface water essential to the maintenance of many vertebrate populations;
- increased disturbance from an increase in vehicle movements, dust, noise and lighting
associated with gas mining operations; - cumulative impacts resulting from the exacerbation of perturbations already operating in the project area due to climate change, particularly the loss of hollow bearing trees,
vegetation loss and increased fire frequency.
The coal seam gas industry results in industrialisation of the landscape with compressor stations, water treatment plants. By pumping out huge amounts of water from the coal seams leads to depressurisation of upper aquifers.
This has already happened in Queensland. In one region, the Surat Cumulative Management Area, a 2021 QLD government report found that over 700 bores have already been impacted by coal seam gas or will be in the coming years. That figure keeps rising, from 459 in 2016 and 571 in 2019.
The report also reveals the industry in the Surat area is:
- taking about 54 billion litres of water each year,
- causing groundwater levels to drop by more than 400 metres in some areas,
- expected to expand from 8,600 gas wells currently operating to about 22,000.
- causing farmland to sink due to depressurisation of coal seams beneath the surface.
Health Impacts
There is a body of peer reviewed scientific papers showing the health issues associated with living in a gasfield due to the air borne pollutants.
Dr Geralyn Mc Carron had this to say:
“No longer can the ill health reported by families in Queensland’s gas fields be dismissed as merely anecdotal. Enough peer reviewed medical evidence is already in. Women exposed to fine particulate air pollution in late pregnancy have double the risk of having an autistic child. Babies born within 2½ km of a gas well had lower birth weight and more health problems than babies born within 2½ km of a well-planned but not drilled.
Children born in areas with the highest number of gas wells were found to have a 30 per cent increased rate of congenital heart defects compared to children in areas with no gas wells within 10 km.
Co-existence is a failed experiment, and throughout the terms of the Bligh and Newman
governments, the noses of the children in the Tara gas fields continued to bleed.”