IT is the lifeblood of our grazing areas and for a group of landholders south of Wallumbilla, access to free flowing bores has provided water security that many would envy.
That is until recently.
In the past 18-months, a small pocket of landholders south of Wallumbilla have watched on as their previously free-flowing bores have at times stopped flowing completely and started releasing levels of gas unseen in the region before.
Landholders, who have never even bothered with water storages because their bores were so reliable, have been forced to abandon troughs where water will no longer flow to and monitor other troughs daily to release a continuous build-up of gas.
Frustrated and concerned about what was happening to their bores, the landholders established the CSG Net in 2013 to encourage other landholders in the area to monitor levels on water bores in the region.
CSG Net was established in partnership with the Department of Natural Resources but landholders say the situation had become so critical in recent months that more urgent action was now required to determine what was happening to the bores.
Many of the landholders have become sceptical about the science used to predict the impact of CSG activities on underground water supplies and say the future of such a valuable resource cannot be left to chance.
“I don’t like throwing darts but I believe something is going on,” said Andrew Sutton from Sunnybank, 60km south of Wallumbilla.
“This place was proper safe with water and now it’s not. We have a big ocean under the ground and I don’t think they know enough about what’s going on down there.”
In response to questions from Queensland Country Life regarding the issues facing landholders south of Wallumbilla, the Department of Natural Resources and Mines (DNRM) released the following statement:
“The static head pressures in water-bearing formations across the Great Artesian Basin have been declining since the first artesian bore was drilled in 1878.
One bore that taps the Gubberamunda Sandstone formation in the area south of Wallumbilla has had pressure reductions amounting to approximately 17m over the past 40 years.
"The increased gas in the water supply of bores in the area can be shown to be caused by the reduction in static head pressure over time, releasing increased volumes of gas from geological formations tapped by water bores.
"The closest CSG production wells are some 13 kilometres northwest of Wallumbilla. It is unlikely that the increased gas in the water supplies is being influenced at all by CSG activities at this time.
"Static head pressures have declined by an average of 0.4 metres per year over the last 40 years. Above average rainfall in the period 2009 to 2013 reduced the pressure on the groundwater resource in the area, resulting in a rise in static head pressures during the period 2010 to 2012.
"The recent dry conditions have resulted in increased water use and additional take from the groundwater resource and a resultant decline in static head pressures. It is likely that this has caused some low-pressure bores to cease free-flowing in recent times.
"Again, it isn’t considered that bore problems associated with increased gas or reductions in static head pressure are influenced at all by local CSG activity.”
Simon Body doesn’t claim to be an expert in the science of artesian water but he’s also sceptical about the claims being made by the State Government and the CSG industry about the impact of CSG activities on underground water.
When Mr Body and his wife Katrina purchased Tallar, 19km south of Wallumbilla in 2003, the reliable, free flowing bores were a major drawcard.
Tallar is watered by two water bores that were drilled in the 1970s. Unlike many other bores in the area that were initially sunk for oil and gas exploration and later converted to water bores, Mr Body’s bores were sunk solely for the purpose of stock water.
When the Body’s purchased Tallar they installed gauges on the bores to test the pressure in order to plan a new water reticulation system around the property.
At that time, the bores had a pressure reading of 140KPA and no visible gas.
That reading stayed static for a decade, with regular readings of 140KPA diligently recorded and filed away by the Body’s until November last year when it suddenly dropped to 105KPA.
At the same time, Mr Body was noticing large amounts of gas at the bore heads and connected troughs. On several occasions he ran out of water at troughs due to air locks caused by excessive gas and the drop in pressure.
This week another test revealed the pressure had dropped further, to 95KPA.
Each test was carried out under the same conditions with the bore switched off for 12 hours prior to ensure an accurate reading and on several occasions staff from Santos were also present for readings.
Mr Body has been repeatedly told by staff at Santos and the Department of Natural Resources and Mines that the increase in gas and drop in pressure experienced at his bores was a natural event.
It’s a line he’s no longer prepared to accept.
“I have no argument with the Department about the fact that some bores are in a natural decline but a drop in pressure that great and that fast is certainly not a natural decline,” he said.
“It dropped from 140KPA to 95KPA in just over 12 months. That equates to a decrease of 4.5 metres of head.”
Mr Body said his greatest fear was that his experience, and the experience of his neighbours, pointed to a far wider issue.
“If there has been some effect from CSG extraction on underground water it will be the free-flowing bores that are impacted first,” he said.
“The bores we pump from aren’t impacted yet because the pumps are 30 metres under the water head so it may well have dropped but as long as the pumps keep pumping people aren’t aware.”
It is an argument that Roma pumps specialist, Mark Huntly, Pumps and Solar, agrees with.
“If there is a change to the water bed the flowing bores will see it first,” Mr Huntly said.
“It could be happening extensively in bores that you are pumping from but you won’t know until the water level gets down to where the pump is.”
Mr Huntly said it was vital that the State Government and the CSG industries not dismiss claims like those being made by the landholders south of Wallumbilla.
“One might be an isolated case but when it happens to two or three landholders over a short space of time then you have a pattern,” he said.
“The gas companies and the Department need to be made aware of it and they certainly wouldn’t want to dismiss it.”
Santos did respond to questions from Queensland Country Life after our print deadline this week.
The company released a statement that said analysis undertaken by the Queensland Department of Natural Resources and Mines (DNRM) in February 2013 found no link to gas activity in the area.
The statement went on to say:
"The DNRM report found that:
- There is no linkage with coal seam gas (CSG) activity. The closest CSG well to the test sites is approximately 24 kilometres away.
- It is not considered that there is any link to historical conventional gas infrastructure in the area.
- Gas appearing in bores is most likely naturally occurring in the Gubberamunda or other shallow aquifers.
- It is possible that increased use of water bores accessing the Gubberamunda aquifer during the recent dry conditions has exacerbated the issue.
"The DNRM report also noted that the static head pressures in water-bearing formations across the Great Artesian Basin (GAB) have been declining over the long-term.
"It noted that declining static head pressures causes increased volumes of gas to be released from geological formations tapped by water bores.
"Furthermore, testing conducted for Santos GLNG by two accredited laboratories shows that the gas in these bores does not originate from the coal seams.
"Santos GLNG has notified landholders and the Queensland Government’s CSG Compliance Unit of the testing results.”
Penelope Arthur
Journalist for Queensland Country Life at Roma.
Journalist for Queensland Country Life at Roma.
