There has been little fanfare over a Defence Department decision to build a Resin Regeneration Plant at the base.

Building of the plant finished in June, it was confirmed this week.

It is already operational.

Synthetic resin beads are at the heart of the water filtering plants which remove water from Katherine's drinking water and the two plants at the base cleaning PFAS from contaminated groundwater.

The PFAS was contained in firefighting foams used for decades in training at the Tindal base.

It has contaminated water and soil and has been found to flow through the underground aquifer, underneath Katherine, to empty in the Katherine River.

The new $15 million Katherine water treatment plant, being paid for by Defence, will also use resin to clean PFAS from water when it is installed late this year.

The smaller plant, currently being used to clean PFAS from a small portion of the town's water, that takes from Power and Water's two bores, will also supply its saturated resin to Tindal.

Simply put, the PFAS sticks to the resin beads and when it becomes saturated it is removed and replaced with more.

More reading:

Katherine's PFAS timeline.

This saturated resin beads will now go to Tindal to be cleaned or "regenerated" so the resin can be reused.

A defence spokeswoman said the PFAS would be stored in sealed drums at Tindal until sent for disposal.

Ten cubic metres of the PFAS saturated resin was removed from Katherine's smaller treatment plant for disposal back in January.

There is already 10 cubic metres of PFAS waste from the Katherine swimming pool being stored in drums at the base.

Katherine Times has previously been told the sealed drums are contained in a shipping container.

"The facility that the PFAS waste is stored at is on Commonwealth land and therefore the NT EPA does not have jurisdictional control or oversight in this regard," an EPA spokesman has said previously.

The construction of the resin plant was revealed by lead Defence spokesman Steve Grzeskowiak to Katherine Town Council last week.

It was also revealed 10,000 tonnes of soil need to be excavated from the Tindal PFAS hot spots - chiefly around the base's fire training areas - and somehow treated.

Excavation works are hoped to start there later this year and the soil will be stockpiled until a treatment option is found.

"The regeneration process detaches the PFAS compounds from the resin beads in concentrated form, allowing the clean resin to be re-used in the water treatment plants a number of times," the Defence spokeswoman said.

"Once the concentrated PFAS waste is removed from the resin, it will be stored in sealed containers at RAAF Base Tindal until disposal.

"At this stage the regeneration plant is only servicing those located in Katherine," the spokeswoman said.

Williamtown in NSW already has its is own, similar regeneration plant.

Meanwhile, Katherine Town Council has taken delivery of the scale model of Katherine's new water treatment plant from Power and Water who revealed it at the recent show. It is on public display in the civic centre foyer.

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