Eels in two South Taranaki streams have been found to have elevated levels of chemicals associated with firefighting foam.
The eels were in the Oaonui and Ngapirau streams are relatively inaccessible and iwi and local residents have been notified.
Taranaki Regional Council director of environment quality Gary Bedford says the potential long-term effects of these chemicals on human health are unclear and under research.
The council has referred its findings to the Ministry for Primary Industries for food safety advice.
Gary says the chemicals are from PFAS, constituents of firefighting foam.
"They are also widely used in or on everyday items such as furniture and carpets, cooking equipment and food storage containers. New Zealand has no standards for PFAS chemicals in foodstuffs."
The council decided to begin an investigation after environmental PFAS contamination was found in other regions earlier this year.
The firefighting foam was formulated for use on hydrocarbon fires in particular, and the council focused on sites where it had been stored. In most cases, the companies involved were doing their own checks and investigations.
Investigations have also found elevated levels of PFAS in groundwater at five sites — New Plymouth airport, the Paritutu tank farm, Omata tank farm, and Maui Production Station and adjacent Hot Fire Training Facility at Oaonui.
Gary says in each case, the groundwater is not known to be used to supply water for human or stock consumption, so there are no direct pathways for human health risk.
No detectable PFAS was in samples of mussels taken from coastal waters near the Oaonui Stream mouth, Port Taranaki and tank farms, and the mouths of the Waiwhakaiho River, Waiongana Stream and Waitara River.
" As they are in effect stationary filters, mussels are recognised as reliable indicators of the presence or otherwise of marine contamination."
Very low levels of PFAS were found in samples of watercress from the Oaonui and Ngapirau Streams and none were found in a control sample taken from a tributary of the Waingongoro River.
"It's important to note that PFAS chemicals have been widely used in a range of consumer and industrial products.
"People are exposed to small amounts of some PFAS in everyday life, through food, dust, air, water and contact with products that contain these compounds."
He says the Council is continuing to work with the community and companies involved in environmental investigations.