Stage one addressed the facts and failings around last August's campylobacter outbreak.
Throughout this week a number of speakers will discuss the issues of stage two - which will look at lessons to be learnt, how to prevent gastro outbreaks in future and changes to improve the safety of drinking water.
The inquiry received over 40 written submissions, or statements of evidence in addressing the stage two issues, a minute released before the hearing stated.
Although the inquiry had read and considered all written statements, there was not enough time to allow each to present their submission orally.
So, the panel had concluded that there were a number of topics . . . that would benefit from "further exploration" at this week's hearing.
The panel sessions would be run as a "hot tub" with counsel assisting facilitating the discussions of each session, by asking questions on key topics.
The issues range from the nature and extent of risks to drinking water, whether all drinking water should be treated, outbreak management, and the strategy for addressing Havelock North drinking water safety into the future.
The inquiry has already made a number of recommendations on the ongoing safety of the Havelock North drinking water supply, in an interim report based on the findings of a June hearing. This marked the start of the second stage.
These included that all bores which supply drinking water to Havelock North, or Hastings be managed as non-secure, and potentially subject to surface water influence, or at risk of contamination from sewerage system defects.
The only way these bores could be considered as secure was after unanimous agreement of Dr Deere and the four members of the Joint Working Group (JWG).
The council has treated all its urban supplies as if they were non-secure since August last year - prior to this all water sources in the district's urban supply were classified as "secure" under the Drinking Water standards for New Zealand (DWSNZ).
The inquiry also recommended the monitoring and testing of all Havelock North and Hastings water supplies be subject to certain conditions, and that checking for protozoa be carried out at each bore bi-weekly until the end of the year.
Some Hawke's Bay councils are already moving forward with plans to secure their drinking water, in advance of recommendations from the inquiry.
Several councils and the Hawke's Bay District Health Board (HBDHB) have confirmed their commitment to establishing a Hawke's Bay drinking water governance committee.
Its aim is to provide governance oversight to the Joint Working Group, established by the inquiry late last year to drive greater collaboration between the agencies on water-safety matters.