Long-term investigations into firefighting foam

clear of the chemicals until one of its nine wells tested positive last month, in the third round of testing by the Marlborough District Council.

The result was 0.0014, which was above the detectable limit of 0.001, but about 50 times lower than levels considered unsafe, according to the Ministry of Health’s interim drinking water guidelines.

The Auckland St bore was switched off following the positive result.

Council operations and maintenance engineer Stephen Rooney said this week all nine bores tested clear again in the fourth round of testing earlier this month, and monthly testing would continue.

The town water supply in Bulls, near Base Ohakea, also tested positive in four of the five bores tested, but the Defence Force said it was unlikely to be from Base Ohakea and was working with the Rangitikei District Council to determine the source.

Parker’s cabinet paper said the scientific community was ‘‘rapidly’’ learning more about the chemicals and how they affected human health.

‘‘There is increasing public concern about the uncertainty of PFAS contamination, what it means for individuals, land owners and businesses, and how it may impact regions around New Zealand,’’ the paper said.

‘‘The evidence of health effects is not clear, and there is no conclusive evidence that PFAS exposure will result in future health problems.

However, potential adverse health effects in humans cannot be excluded.

Parker published the cabinet paper in a bid to follow through on the Government’s commitment for transparency, he said.