WATER leaked from a storage pond at Santos’ Narrabri project has contaminated groundwater with heavy metals and other elements, elevating uranium levels to 20 times the safe drinking limits, according to the State's environmental watchdog.
The Environment Protection Agency (EPA) confirmed the contamination in its investigation of the leaks, which were reported by Santos as part of its ongoing monitoring of the Bibblewindi storage ponds.
Other elements detected in the groundwater include lead, aluminium, arsenic, barium, boron and nickel. The mining company says these are naturally occurring elements.
Santos responded to the news of the leaks, saying impacts of the contamination are localised and do not impact regional groundwater systems used by the community.
The EPA fined Santos $1500 for the leak in February, but has now detailed the nature of groundwater contamination in the Pilliga.
Following these fines, the NSW government moved to fast-track the Narrabri project.
Water produced from exploratory drilling into coal seams, which lay hundreds of metres below the surface, is drawn to the surface and stored in ponds. Poor construction of pond lining is blamed for the leaks.
The Greens' mining spokesman Jeremy Buckingham said the contamination exposes risks that should prevent further development of coal seam gas.
“Here is definitive proof that unconventional gas, such as coal seam gas pollutes aquifers with extremely toxic elements,” Mr Buckingham said.
“This is game over for coal seam gas."
The Bibblewindi storage ponds were constructed by Eastern Star Gas, which was bought by Santos in 2011. The facilities were closed due to their deficiency by Santos shortly after the takeover and a remediation program is currently underway.
A spokeswoman for Santos said the contamination has occurred in shallow perched groundwater covering an area of approximately 30 metres by 30m.
“The concentrations outlined by the EPA are for drinking water. Shallow perched aquifers in this area are not suitable to be used for drinking water purposes.”
“The current concentrations of uranium are below the Australian National Water Quality Management Strategy guidelines,” she said.
Santos is currently constructing new storage ponds at nearby Leewood, located outside the Pilliga, and plans to transfer Bibblewindi water there by the end of the year.
A recent report found groundwater is essential to industries that contribute $34 billion to Australia's gross domestic product (GDP) each year. Agriculture accounts for about 70 per cent of groundwater use and irrigators and livestock producers who rely on groundwater for at least a portion of their water needs generate a combined $27 billion.
The Economic Value of Groundwater in Australia study was commissioned by the National Centre for Groundwater Research (NCGR) and carried out by Deloitte Access Economics.
Independent hydrologist Professor Philip Pells argued that regulation of coal seam gas needs to be reformed to mitigate potential damage to areas with geological characteristics that are more susceptible to damage from gas extraction.
Professor Pells said CSG extraction could co-exist safely in certain areas, such as Camden in south-west Sydney, however other areas such as Sutton Forest, the Liverpool Plains and Gloucester should be exempt from development - at least until the industry is better understood, as the geology is more susceptible to damage.