"But the offer to date has been turned down ...so [we] can't do anything about that."
Yesterday Mr Graham said he made the offer to Hastings mayor Lawrence Yule earlier this week, but understood why the offer had not been taken up.
Mr Yule said the council was not prepared to discuss the investigation as it was before the courts.
"How this happened and all the issues around it is actually in the realms of the Government Inquiry," he said. "We still haven't had the full disclosure of what their [court] case is so it would have been premature for us to do that ahead of time."
Evidence hearings for the inquiry were scheduled for this week, where "it would have been in the public, and all the sides would have been put across", he said.
Although Mr Yule had turned down Mr Graham's offer they would be meeting next week, along with Ngati Kahungunu chairman Ngahiwi Tomoana, to discuss how they could co-operate.
Regardless of the prosecution, and inquiry, Mr Graham and Mr Yule had discussed that the public wanted the councils to sort out these issues.
"It's actually serving... [no] good purpose if we keep focusing on the court case and the inquiry," Mr Yule said. "Sure there will be learnings out of that, but what our ratepayers want us to do is fix this, and get on top of all the water issues we face, and the three of us are committed to doing that."
Although the inquiry postponement means the findings have not been heard before a court, they have been uploaded to the inquiry website.
Prepared by HBRC manager environmental science Dr Stephen Swabey, the investigation report claims campylobacter "entered the drinking-water system because flooding carried the contaminant over land, and the bore headworks allowed that water to enter the bore from above."
"This indicates the wellhead is insecure, causing discharge of contaminated water into the Havelock North water supply."
The report stated there had been heavy rainfall about a week prior to the outbreak, which caused overland flow in paddocks south of Brookvale Rd, and filled the drains at the side of the road with water on the morning of August 6.
Dr Swabey wrote the investigation had identified the source of the contamination needed to be close to the bore field, or well connected with the bore field through a water flow path, because campylobacter does not live long.
The report claimed more than 1600 sheep were in the paddocks from which the flood flows reached the bore chambers during early August, and in a nominal five days, these sheep would have produced approximately 7.1 tonnes, or 7076kg of faeces.
Only a small volume of faeces - less than a kilo - was required to cause all the infections in Havelock North, the report stated.
The report also alleged the bores' sump pumps - which remove any surface water that enters the bore chambers - could not operate on August 6 during the two power cuts that morning.
"Immediately following the power cuts on August 6 2016 the water supply pumps in both bore 1 and bore 2 ran for several hours. During this time, any contamination present in the bores would have passed into the water reticulation network, including into the reservoirs around Havelock North," the report claimed.
Mr Yule said the district council had a very different theory about how the contamination occurred.
"And if I didn't I'd probably be less strident in my opposition of what they're saying."
