Never-before-seen documents show a senior government official feared children could die if they came into contact with toxic chemicals that were pouring directly onto a popular New Plymouth beach.
The documents were uncovered as part of research for the paper Silencing Paritūtū which claims there was a long-standing campaign to suppress evidence about the risks of dioxin emissions from a herbicide plant at Paritūtū during the 1960s.
Ivon Watkins, later Ivon Watkins-Dow, made the herbicide 2, 4, 5-T at Paritūtū from the 1960s until 1987.
It contained the dioxin TCDD which was a key component of Agent Orange - the defoliant used by the US military in the Vietnam War. It has been linked to cancers and birth defects.
Levels of TCDD were highest in the herbicide in the 1960s.
Jimmy Stoppard grew up on Marama Crescent which backs onto the Paritūtū plant.
The 67-year-old, who now lives in Melbourne, remembers the reek of chemicals while out surfing nearby in his early teens.
"In some stormy type sessions you could even taste it in your mouth and quite often the whole of Back Beach along where that stormwater outlet, drain outlet was the water was nothing but foam as though someone had tipped a packet of washing powder in there."
At about the same time Stoppard and his mates were regular surfers at Back Beach, the Ministry of Works wrote to the Marine Department about that stormwater pipe which Ivan Watkins factory fed into.
In the July 1967 letter, Commissioner of Works J. L. Laing said birds were being poisoned because chemicals were reaching the foreshore via the pipe, which should have been extended beyond the low tide mark.
He said the Taranaki Harbours Board had turned a "blind eye" to this and he was not happy.
"I am very concerned about this matter because some child may be killed. Urgent action should be taken to stop the discharge of chemicals. Further failure to comply with the conditions should be followed by prosecution under the Harbours Act."
The Ministry of Health's Taranaki office responded the following month.
The writer was dismayed at the crudeness of the pipe, which was open-ended and discharged about five metres down onto the beach below.
They said although the discharge had a distinct chemical odour, the smell, and the plant's emissions, had been investigated by the company and "controls" had been put in place.
"We consider there is little risk to children under normal circumstances, and we are confident that if a major spill occurred on any paved yard of the factory, the company would - for its own protection - see that disposal was complete and without any hazard to the public."
The writer concluded that taking the pipe to beyond the water's edge would safely disperse any residual chemicals.
Sometime in the 70s stormwater from the Paritūtū was directed into the mains system.
The co-author of Silencing Paritūtū, Andrew Gibbs, said the letters - which were found in the National Archives - were important because they indicated concern about the plant's emissions in the 1960s - the period of highest exposure.
Stoppard said he did not think much of the chemical taste he experienced at the time, and even went on to work as a fitter welder at Ivon Watkins-Dow.
But more recently, a cancer diagnosis has given him pause for thought.
"They took the whole right-hand side of my large intestine out and when they did the pathology on that it came back I had mantle cell lymphoma and when they investigated they found it in my neck, one of my lungs, my groin, my spleen and my bone marrow, so they classified me as stage four."
After a gruelling course of chemotherapy and stem cell treatment, he was now in remission.
The Ministry of Health said an inter-governmental group has overseen several pieces of research into Paritūtū, including the Taranaki Regional Council's report on alleged historical dumpsites, and the Taranaki Medical Officer for Health's investigation into health effects in Paritūtū.
"The studies found no evidence of inappropriate disposal and no difference in cancer registrations, respectively."
The ministry also contracted ESR to investigate non-occupational exposure to dioxins among current and former Paritūtū residents.
"The findings of this study showed elevations in serum dioxins which were most likely caused by breathing in emissions originating from the agrichemical plan."
As a result of these findings, the ministry said it established a health support service in 2008 for dioxin-exposed people which aimed to promote healthy lifestyles, reduce modifiable risk factors, and support early detection of disease.
The Taranaki Regional Council said it had no record of any emissions testing at Ivon Watkins Dow during the 1960s.
It only began monitoring air quality at the site in the 1990s following the introduction of the Resource Management Act.
The council looked into the discharge pipe at the northern end of Back Beach in 2001 as part of its investigation into alleged waste disposal sites in New Plymouth.
It detected 2,4, 5-T at a level of 0.4 parts per billion, above the New Zealand drinking water standard of 10 parts per trillion.
Similarly, the levels of TCDD in marine biota while slightly elevated above those found by the Ministry for the Environment in its survey of background levels of dioxins in marine biota around New Zealand, the levels were similar to those found in seafood in the ministry's study of dioxin intake in New Zealand diets.
"From the investigations from this council, there is no evidence of inappropriate discharge of chemicals at this site. There is no evidence of environmental risk."