The Defence Force could face prosecution over contamination from toxic chemicals used in firefighting foam.
The Defence Force has admitted chemicals used in firefighting foam before 2003 have leached into nearby soil and water at bases in Ohakea and Woodbourne in Marlborough and contaminated seven neighbouring properties, including five in Manawatu.
The head of Horizons Regional Council, Michael McCartney, said the organisation had started an investigation into the contamination under the Resource Management Act.
"There is a process by which we take various levels of enforcement action, ranging from abatement notices to enforcement orders to full-scale prosecutions that are matters to be heard by the court.
"So they are the menu of things to be considered, but that's all evidential.
"We need to look at the facts, we need to look at the case and we're taking advice on that currently."
It was a public health issue, but farmers in particular were also worried about their livelihoods, he said.
"Is their milk still going to be picked up by Fonterra? Is their meat still OK to sell? These are the kind of questions bouncing around in the community, and you can understand why."
Mr McCartney said he had spoken personally to the Defence Minister Ron Mark to urge action.
Testing began in December, even though the Defence Force was told that the levels of chemicals present at Ohakea airbase in the Manawatu exceeded acceptable levels in June.
Manawatu District mayor Helen Worboys said families, many of whom had lived on the land for generations, were worried about their health and the future of their farms.
She had been told many stories of cancers, birth defects and deaths, and sick animals that seem to recover when not on affected land.
"It's natural for people when something like this happens, they go on Google and start putting two and ten together about things that have happened in their families and on their farms."
The lack of official information was feeding fears and rumours, she said.
The regional council's science manager, Abby Matthews, said the council had asked the Defence Force to widen its testing radius to include the township of Sanson and the Bulls side of the Rangitikei River.
"On the basis of the modelling that they've already carried out, they've established where they think the boundary of the contamination is currently extending to.
"We're asking them to go beyond that and test beyond that boundary."
In a written statement, the Defence Force said the question of testing boundaries was "a sensitive one" for landowners and to protect their privacy, it was not releasing boundary information at this stage.
"Our testing is based on groundwater modelling and in light of the results from the first round of testing, we have extended the initial testing area," a spokesperson said.
"Those people in that area will be contacted by us seeking permission to test their water. We will also be speaking to Horizons Regional Council directly."
Meanwhile, officials from Defence, the Ministry for Primary Industries, the Ministry for the Environment and the Health Ministry were meeting with representatives from local councils today to discuss the next stage of the inquiry, which was likely to include crops and animal health.
The Environmental Protection Authority is also investigating the wider use of the foam after Auckland Airport said it was still using it late last year despite it having been banned in firefighting standards in New Zealand since 2006.
What is the foam?
A fire retardant used by the Fire Service, Defence Force, Marsden Point oil refinery and airports. The foam contains the chemicals PFOS and PFOA - manmade chemical compounds which don't break down.
These are the most commonly used of the perfluoroalkyls chemical family, or PFAS, and diffuse extremely readily in air, dust, surface and groundwater, soil and sediment.
Human bodies get rid of PFOA and PFOS from their systems much more slowly than other animal species.
PFOA and PFOS are found in other things too, including some carpets, waterproof jackets, non-stick frying pans, and sneakers. Since 2010, some companies have been signing up to stop using these chemicals.
It has been banned in firefighting standards in New Zealand since 2006 and hasn't been used by the Defence Force since 2002.
However, Auckland Airport is still using a foam containing PFOA and the Environmental Protection Agency has announced an investigation.