Saturday, November 27

The Defense Force takes measures to counteract wastewater pollution at the naval base


The Defense Force says it has installed a special filter system at its Auckland naval base because toxic chemicals used two decades ago continue to find their way into wastewater.

Devonport Naval Base

Investigations in Devonport in 2019 showed that the Defense Force had to do something about discharges of PFAS that were not in compliance.
Photo: RNZ

The Devonport base installed the specialized filters last November to deal with PFAS chemicals from the now-banned historical use of fire fighting foam.

PFASs are a parts per trillion threat, they do not biodegrade or biomagnify in the food chain.

The PFAS fluorine foam used until 2002 by Defense for firefighter training has contaminated Ngataringa Bay, a habitat for endangered birds, together with the Maritime Safety Training Squadron. Fish levels in Waitemata Harbor were low.

“PFAS continues to leach from steel, concrete and asphalt surfaces,” Defense said.

Residues have also been detected in the soil.

“High tides and heavy rains carry PFAS from groundwater to the site’s stormwater system and from there to the site’s water treatment system.”

It no longer uses PFAS foams, he said.

Training with them is prohibited, although that prohibition was recently violated at the Northland oil refinery.

Investigations in Devonport in 2019 showed that the Defense Force had to do something about discharges of PFAS that were not in compliance.

Problems with the old treatment system “exacerbate the accumulation of PFAS,” according to a report in late 2020.

“NZDF committed significant resources for the temporary storage of intermittent discharge water and its subsequent transfer to ChemWaste for treatment and disposal” from 2019 until the commissioning of the new filter.

Defense says the new granular activated carbon filter has fixed the discharges.

PFAS sticks to pieces of carbon as the water flows through the system.

As for contamination at its other bases, revealed by a land revaluation report submitted to RNZ, Defense says it is complying with health and safety and environmental legislation and regulations.

The report gave a rough estimate of $ 28 million to partially remediate 21 sites.

Devonport scored nearly 400 for actual or potential contamination, far ahead of any other base and compared to several other sites at zero.

The report said NZDF should improve the way it assesses contamination risks.

But Defense said its investigative and reporting methods “are fit for purpose.”

They use an official Hazardous Activities and Industries List (HAIL) to rank sites for further investigation based on risk.

“Where the classification … indicates a need for remediation, then that work will be undertaken,” Defense said in a statement Friday.

If it showed a risk of contaminants leaking from a base, that would also be examined.

The contamination was mostly decades old, and current practices and management were at a “different and higher standard.”

Defense’s priority for cleanups under a $ 2 billion 15-year estate update is dealing with toxic lead found in some of its many houses. It is also trying to better deal with lead contamination at its shooting ranges.


www.rnz.co.nz

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