When asked if he felt this would affect his chances of re-election, Mr Yule said that was for the people to decide. "I absolutely do not see this as an election issue," he said.
"I've got a community that is facing the biggest challenge it has ever faced, this is the largest outbreak of waterborne disease to ever occur in New Zealand."
Council test the water twice a week in line with New Zealand drinking water standards.
However, following this event every well in the district is being tested daily as an extra precaution.
They would continue doing so if the investigation found this was needed in the long term.
The council had not considered running extra tests in the week following the major weather event.
Mr Yule said the two bores servicing Havelock North had never tested positive for any harmful presence in their 35 years of operation - which included Cyclone Bola, and other major rainfall events.
Mayoral hopeful and incumbent councillor Adrienne Pierce said it was good Mr Yule had fronted up with an apology.
"The mayor didn't cause [this], but it's how it's been handled. I don't think there was enough [communication with the public] and I don't think it was fast enough," she said.
A council statement released on Friday night was "all well and good", but people had not known where to look for information despite panic setting in as residents knew about the number of absent school students.
"You've got to front foot it as soon as you know there's a problem."
Ms Pierce had worked with the Havelock North Business Association to spread the news, including personally phoning rest-homes to inform them of the situation.
Mr Yule said he knew there was concern about "what happened and when", but he believed the council had acted prudently and appropriately with the information available.
"Normally we would not chlorinate the water until a positive test, which would not happen until the following day, so I would argue we went well ahead of what we would normally do."
He said if they told residents of the issue at 3pm, only to find there was no problem on Saturday, "we would have been having a very different conversation".
As there were still seven weeks until election day, political commentator Mike Williams said if he were the mayor, he would be asking for a fast investigation into where the contamination had come from, but also an evaluation of whether the council response was adequate.
"I would advise the voters of Hawke's Bay to await that inquiry," he said.
"What's important is what [people] believe, not what happened," he said, adding while the perception was that the council had not acted fast enough, this was probably not true.
As a general point, Mr Williams said "these things tend to go against sitting councillors".
