Groundwater near Kapuni wellsites found to be contaminated as long as eight years ago has still not been cleaned up.
But the contamination, which includes three of the toxic BETX chemicals, is not widespread and it has not reached the Kapuni stream, which supplies Hawera's drinking water, Taranaki Regional Council director environment quality Gary Bedford says.
"Let me be very clear – there are bores located between the well head sites and the Kapuni stream, but there is no indication of the contamination reaching that far and the Kapuni stream itself is showing absolutely no indication of contamination – either by chemical analysis or by biological health surveys conducted in the Kapuni stream," he said.
"Everything we see tells us that the contamination is highly localised."
The water is directly underneath the blow-down pits.
They were within the wider exploration site controlled by STOS, he said.
The South Taranaki District Council has tested all its water schemes including the Kapuni bore and river and found no evidence of contamination.
It has now set up its water monitoring system at the Kapuni Treatment Plant to check for the chemicals.
The contamination has been around for quite a while.
It was recorded at one site in 2004 and others in 2007 and 2008, but it has yet to be cleaned up.
Mr Bedford expects that to begin soon.
The problem comes from the blow-down pits where chemicals were stored. Before Shell Todd Oil Services Limited alerted the TRC of the contamination, a resource consent was not needed for the storage.
STOS general manager Rob Jager said the unlined pits were no longer used. Steel tanks will be used to fully contain all fluids during the drilling operations this year.
The situation was contained in a TRC report last year, which was tabled in Parliament a couple of weeks ago by Green MP Gareth Hughes.
He asked Energy Minister Phil Heatley if the contamination was enough evidence for Mr Heatley to put a moratorium on fracking. It wasn't.
But both Mr Jager and Mr Bedford said it was unlikely the contamination had anything to do with fracking.
STOS does not use BETX as part of the fracking process, Mr Jager says.
"These compounds (BETX) occur naturally in gas and condensate (light oil).
"We have an ongoing monitoring programme around it and continue to work with the Taranaki Regional Council," he said.
Have you signed up to stop smoking?