Toxins off charts at Devonport

The defence force is playing down new data showing levels of firefighting foam toxins averaging 80 times the recommended levels at training sites near Devonport naval base.

A report released last week said there was ‘‘significant contamination’’ of soil and marine environment at the Sea Safety Training Squadron at Ngataringa Bay, with toxic PFAS and PFOA found in firefighting foam.

The bay was used for, kayaking, sailing and sea-swim training among other activities.

Now, new data, released to RNZ under the Official Information Act, show levels of PFAS and PFOA between 35 to 115 times higher than the guideline limit for recreational water in groundwater in testing conducted in 2016 and 2017.

One result showed the levels at 14,000 times higher than the standard.

However, the New Zealand Defence Force said it does not believe there is significant cause for concern about PFAS on the mudflats or in the water of the bay, spokesperson Phil Murray said.

While investigations found the groundwater was contaminated, after dilution the PFAS concentration was not expected to exceed the relevant guidelines in the water of Ngataringa Bay.

Also, the areas tested around the mangroves and mudflats were well below the guidelines.

Also, the NZDF said the result showing contamination of 14,000 times over guideline levels was most likely to be crosscontaminated.

The well was re-tested the following year and the result was more in line with readings from other wells. Based on expert advice, NZDF therefore concluded this isolated reading was not indicative of actual PFOS levels.

Further testing was carried out last week to increase understanding of impact on the marine environment. The results are expected in April and will be shared with Auckland Council, Murray said.

At Devonport, there is no danger to the public from drinking water because local water was sourced from the town supply.

The Ministry of Environment said it is safe to swim and shower in potentially affected water because exposure to toxins will not pose any significant health effects immediately, the website said.

SIMON MAUDE/STUFF Banned firefighting foam toxins were at more than 110 times the guideline limit near Ngataringa Bay.