WATER authorities face a struggle to keep Katherine’s drinking water at safe levels.
The town’s two bores, which supply the town’s water treatment plant, are producing some of their worst ever results for PFAS concentrations.
In testing results made public today, Power and Water said Katherine’s bores had returned “average” results across August of 0.23 micrograms per litre.
The national drinking water upper limit is 0.07.
Katherine’s bore water is blended with river water and treated to supply the town’s water.
Katherine’s tap water was also tested in August with an average result of 0.02, down from the 0.03 of the previous month.
The bore result was 0.12 in July.
Water restrictions began in Katherine last month to reduce the demand on the treatment plant to better cope with the higher bore contamination levels during these peak use months of September and October.
Authorities fear most the first rains of the wet season which produce a “flush” of bacteria in a turbid river.
An emergency add-on for the treatment plant, being paid for by the Defence Department, is still at least a month away, mostly likely two.
In a letter to the Katherine Times this week, the department says the “interim ECT 2 water treatment plant” is expected to arrive in Australia this month and to begin treating water as part of the commissioning phase in October.
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“The interim ECT2 water treatment plant is expected to treat PFAS affected bore water prior to blending it with river water to generate the town water supply,” the department wrote.
“The interim ECT2 water treatment plant will filter PFAS from the bore water before it enters the purification and blending process in the Power and Water Corporation’s water treatment plant.
“The interim ECT2 water treatment plant will be capable of processing the majority of the bore water currently required for town water supply. This will significantly reduce the levels of PFAS in the town water supply,” the department said.
State and Federal health authorities have confirmed that the Katherine town water remains safe to drink.
“Defence will continue to work with the Katherine community and the NT Government as it investigates and implements strategies to reduce PFAS exposure,” the defence department wrote.
Chief Minister Michael Gunner told Katherine Times late last month his Cabinet had not discussed a back-up plan for Katherine’s drinking water if levels rose above 0.07.