And a long delayed deal to buy a bigger water treatment plant for Katherine is believed to be imminent.

The cost of the plant to end water restrictions and provide guaranteed safe water for the town is put at $13-$14 million.

The Defence Department this week released the final in a series of environmental reports regarding PFAS and Katherine.

Now the full extent of the contamination is known, which is still flowing in the groundwater from the Tindal RAAF Base under Katherine, and into the Katherine River.

Defence has begun installing two water treatment plants at Tindal in an attempt to intercept the PFAS before it leaves the base.

A bore field basically on top of the base’s old fire training area will intercept ground flow, remove the PFAS and re-inject the cleaned water back into the aquifer.

Defence lead spokesman on PFAS, Steve Grzeskowiak told Katherine Times the next steps on PFAS were management and remediation.

He said 65 water tanks had been installed at homes near the base not connected to the town’s treated water supply and formerly reliant on bore water.

“Next dry season we will focus on the soil,” he said.

Ground zero for Katherine’s PFAS contamination is the former fire training areas on the base where the problem chemicals were contained in fire fighting foams once used there.

He agreed the water plants would have to continue operating for many years.

“I don’t think anybody can accurately say how long we must operate … but it will be many years.”

Mr Grzeskowiak said the science for removing PFAS from water was much more advanced than soil.

He said Defence was still investigating the best methods for treating the contaminated soil and were undecided on whether to dig it up, stockpile it in a proper containment area and stop any further leaching into the groundwater.

Capping the soil where in lay is another option being explored.

Defence was evaluating new scientific methods for removing PFAS from soil, he said.

On the subject of Katherine’s long overdue water treatment plant, Mr Grzeskowiak said he was meeting with Power and Water officials this week to “dot the i’s and cross the t’s”.

He said Power and Water had determined a new plant, similar to the smaller plant already in operation treating a megalitre of contaminated bore water a day, would be needed.

The new new plant, also sourced from the US, would be capable of treating 10 megalitres a day and end the need for water restrictions.

More stories:

Final environment report on PFAS.

Tindal spend now close to $1 billion.

Mr Grzeskowiak put the cost of that plant at between $13-$14 million which he said Defence has already agreed to pay for.

He said Power and Water has already assured Katherine residents the delay in signing contracts would not delay its arrival, expected about this time next year.

Defence is developing a PFAS Management Area Plan  which outlines activities that Defence will undertake to manage and reduce the risks of PFAS exposure for RAAF Base Tindal and the Katherine community.

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