Former public health officer Ian Inkson confirmed that no one responded to his concerns over the potential contamination of Brookvale 2 Bore in 2002.
Now, 15 years later, his complaint about an "insecure control cable duct" if actioned could have potentially prevented the campylobacter outbreak, which left 5500 people sick, 45 in hospital and possibly three dead, the inquiry heard.
In an email to Hawke's Bay Regional Council consents adviser Tim Waugh and Hastings District Council water engineer Peter Free, Mr Inkson said a bore "in his interpretation contravened rule 3" of the Proposed Resource Management Plan.
The email stated that an "insecure control cable duct" gave the potential for leakage of contamination from the surface down into the aquifer close to the drinking water bore.
"It is considered that contamination could be introduced by this bore and due to the draw down from the Brookvale 2 Bore be sucked up through that bore's water.
"It is considered that this could cause enteric contamination of the groundwater through an animal defecating in the area of the insecure duct or when floodwaters cover the ground surface most notably when at a height greater than the control cable duct."
Neither council had any record of their responses to this complaint and the inquiry was left with no significant evidence other than the email itself.
It was noted that if this complaint had been actioned adequately by the regional council in 2002, it should have led to the detection of numerous insecure bores in the vicinity of the district council's drinking water bores.
The inquiry received evidence from the district council's investigator, Mr Mananui, of at least 12 insecure bores in the vicinity of Brookvale Rd. These clearly involved a contamination risk for the drinking water source.
"Undoubtedly, the 2002 Mr Inkson email was another missed opportunity for both the regional council and the district council.
"Neither organisation identified insecure bores as a significant area of risk to the aquifer used as the source for Havelock North drinking water."
Mr Inkson told Hawke's Bay Today exclusively that after a 1998 campylobacter outbreak, he thought both councils might have been more diligent.
In 1998 there were cases of campylobacter from the same bores and the likely point of entry for contaminated surface water was a leaking power supply cable gland.
"Regrettably, while the two outbreaks shared remarkable similarities, it appears nothing was learned from the July 1998 outbreak," the inquiry stated.
The former Hawke's Bay District Health Board drinking water assessor was disappointed that he never had a response regarding his complaints.
"An email is a form of prompt writing and it is not unusual to not get a response, I guess it depends on how they view the priority of what is being said.
"I think the inquiry is justice being served and they have put together a reasonable report so I sure do hope the bore is fixed now."
Hawke's Bay Regional Council chairman Rex Graham said it was a "disgrace" that no one responded to an official representative of public health.
"If his complaint subsequently does prove to be correct it is terrible, but nevertheless even if it doesn't his email should have been taken seriously and given consideration. It is a big let-down from both councils."
Hastings Mayor Lawrence Yule agreed that the email should have been responded to and said he couldn't defend either council's actions.
"This is all part of the findings and we are looking at how this can never happen again."