Second round of tests for Ohakea groundwater after firefighting chemical contamination

In this 2006 photo, firefighters at Ohakea air base are hosing down a plane that made a wheels-up landing. Photo / Getty Images

Ohakea residents whose drinking water is contaminated are getting water from other sources but now worry about their livelihoods and futures, Manawatu Mayor Helen Worboys says.

The Defence Force has again tested the groundwater around Ohakea air base for contamination by firefighting chemicals.

The checks takes in the original 23 properties tested, and others further out. When results come through they will go direct to residents, with an explanation from the Defence Force.

A first round of testing found traces of a chemical from firefighting foam, known as PFAS, at 19 of the properties. At 13 it was found in groundwater and at five it was found in groundwater used for drinking.

The PFAS chemicals (per- and poly-fluoroalkyl substances) are long-lasting in the environment and long-term exposure can affect human health. They are not known to have any acute effects, the Health Ministry says.

Residents have complained of illness and of stock not doing well, but the Ministry for Primary Industries says there is no evidence that PFAS is the cause.

Residents have been offered alternative drinking water. They are waiting to hear how the Defence Force will provide them with longer-term sources of drinking water - probably rainwater tanks. Ms Worboys wants an action plan to get those installed before winter.

The Ministry for the Environment is now the lead agency dealing with the contamination, and Jen Rose is its recovery manager. Affected residents have formed a group that meets with her, and other agencies.

They may yet be part of a class action against the Defence Force.

The contamination was made public in early December, and there was a first round of testing. The results have sparked an investigation by the Environmental Protection Authority into other contamination by PFAS chemicals.

The Defence Force has not used firefighting foam with the chemicals since 2002, but Nelson Airport was found to still have some and they may be elsewhere. Defence Force facilities at Devonport, Hobsonville and Whenuapai are to be tested.

The chemicals have been illegal in New Zealand since 2011, except for special and limited uses, the Environment Ministry website says.

They come in thousands of forms and since the 1950s have been used in a huge range of products, including furniture protectants, textile coatings and colour photocopiers. They were not known to be a pollutant until the 1990s.