Despite taking action to prevent coal-seam gas miner Metgasco from disposing of potentially polluted wastewater into the Casino Sewerage Treatment Plant (STP) the Environment Protection Authority (EPA) has flagged the possibility of the water being used for agricultural irrigation in the future.
The EPA made the comment in a letter written to the Environmental Defenders Office (EDO) earlier this month, which was acting on behalf of Lock the Gate Northern Rivers (LTGNR).
The letter, written by EPA’s north coast region manager Brett Nudd and addressed to EDO lawyer Sue Higginson, admitted that 1.36 megalitres of potentially contaminated water had been unlawfully released into the Richmond Valley Council’s (RVC) STP.
The letter confirmed the NSW Office of Water’s view that the disposal of water via an STP was ‘inappropriate’ and advised RVC not to process any further water through its STP. But the reason given was a technical one, saying that the liquid for disposal didn’t constitute ‘human septage/effluent’.
It went on to say, ‘Metgasco has also been advised that the water contained in its storage ponds cannot be disposed of via a STP. Further, the produced water needs to be assessed against the EPA’s Solid and Liquid Waste Classification Guidelines to identify lawful disposal pathways’.
But the letter also said, ‘if coal-seam gas produce water is managed appropriately and not cross-contaminated with drilling fluids or other related compounds, there is potential for this water to be sustainably utilised as a resource for agricultural irrigation. The produced water would need to be analysed to ensure it consistently meets ANZECC Water Quality Guidelines.’
The suggestion has rung alarm bells with LTGNR spokesperson Boudicca Cerese, who says experiments with disposal of produced water in Queensland have been very concerning.
‘The Queensland government gave licence approval to a CSG miner there to release wastewater into the Condamine River at elevated levels of heavy metals without apparent consideration of the cumulative impact of such releases over time,’ she told Echonetdaily.
‘Heavy metals are known to bioaccumulate in fish.
‘The industry is relying on the water being treated and used but we’re seeing that reverse osmosis, which removes the salt, doesn’t necessarily remove the heavy metals and other chemicals. They’re just making it up as they go along,’ she said.