9 November 2015
Updated – Whitehaven response to inaccurate assertions about Werris Creek mine
There have been a number of assertions made through the media about water resource management at Whitehaven Coal’s Werris Creek Mine. Whitehaven refutes the claim that the depletion of bores being reported anecdotally by some local landholders and others is in any way related to the workings of the mine. The geology of aquifers and groundwater systems around the Werris Creek Mine and Whitehaven’s own monitoring suggests that the onset of drought conditions in 2012, and rainfall recharge not keeping pace with groundwater extraction for surrounding uses not related to mining, are the major factors implicated in declining water levels.
Groundwater seepage into mine pits is a normal and anticipated aspect of open cut mining operations. This is why the Werris Creek Mine has a water access licence allowing for the interception of up to 211ML of groundwater per year. The Mine is well within this approved limit and is using less than half of its quota. Whitehaven has written to the Member for New England as a matter of urgency to outline its serious concerns with recent public comments made about water management at Werris Creek in more detail.
(Update Nov 10 2015): A letter previously sent to Greens MLC Jeremy Buckingham regarding inaccurate assertions made regarding Werris Creek can be found at this link: Letter to Jeremy Buckingham
Information Update: 1 September
FURTHER INFORMATION REGARDING WATER MANAGEMENT AT THE WERRIS CREEK COAL MINE
Whitehaven’s Werris Creek mine operates in proximity to the Werrie Basalt Aquifer, which is separated from the Mine’s workings by a clay aquitard that maintains approximately 100 metres difference in groundwater level between the Werrie Basalt Aquifer and the floor of the mine.
Some seepage does occur into the mine pit from the Werrie Basalt aquifer. This is a normal and anticipated part of open cut mining operations and is why the Mine has a Water Access Licence (WAL 32224) permitting the interception of up to 211ML per year in this manner.
Whitehaven’s own long-term groundwater monitoring shows that the Mine consistently intercepts less than half of this permitted allocation per annum.
Whitehaven is not aware of any scientific evidence to support claims that the depletion of nearby bores is in any way related to the Mine’s workings. The Quipolly Alluvium aquifer is more than two kilometres from the Werris Creek Mine and is separated by the Werrie Basalt aquifer, which forms a natural partition between the Mine and Quipolly Creek. Real evidential data gained from long term monitoring of both the Quipolly Creek Alluvium and Werrie Basalt aquifers shows that the levels in the two aquifers are dependent upon rainfall recharge.
Changes in aquifer levels have been observed and recorded throughout the life of the mine, including during 2011 and 2012 when groundwater levels reached historic highs due to correspondingly high levels of rainfall during that period, and at which point the Mine itself had been operating for over five years.
Whitehaven’s long-term monitoring suggests that the onset of drought conditions in 2012, and the fact that rainfall has not kept pace with groundwater extraction for irrigation by surrounding land users since this point, are the primary factors implicated in declining groundwater levels in the area.
We estimate that the entire groundwater system monitored to the south of Werris Creek Mine has lost approximately 15,600ML since 2012. Since 2012, Werris Creek received approximately 718ML annually in void water from rainfall runoff. During that same period, as with today, our total usage on site is approximately 350ML per year for dust suppression purposes. This modest level of annual water use is indicative of the fact that the Werris Creek Mine sells its product in raw form and does not have or need a coal washing facility on site.
To be clear, the Werris Creek Mine has water storage capacity of only 755ML at any point in time. Taking into consideration our low on-site usage (half of what rainfall provides the Mine even in drought conditions per annum), it would be impossible for the Werris Creek Mine to receive, use or store the volume of water implied by our estimated drawdown above (some 5,000ML per year over the last three years).
Any suggestion that the reported depletion of nearby bores has occurred suddenly or is associated with significant volumes of water from neighbouring aquifers being diverted and stored at Werris Creek is not supported by scientific data and any other observable evidence. No aquifer has ever been ‘pierced’ or ‘intercepted’ at Werris Creek.
Another relevant fact is that during 2012 the Quipolly Dam wall was raised to increase the capacity of the dam from 5,000ML to 7,500ML. At the same time, the Dam was declared a zero discharge facility to preserve water for town water use where previously this Dam fed Quipolly Creek. This effectively removed a significant source of water resource recharge in the region.
It is worth noting that as recently as 23 July, 2015, representatives from the NSW Office of Water and the NSW Department of Planning and Environment visited Werris Creek Mine. In concluding their visit they informed site management that they were satisfied that the water management on site was in compliance with all relevant regulations.