Water New Zealand chief executive John Pfahlert says the industry needs to learn from the Havelock North Water Inquiry's findings so that a similar contamination event does not occur again.
The organisation is a non-profit technical and educational body for environmental management professionals with about 1500 members in New Zealand and overseas.
Reacting to the release of the inquiry panel's report yesterday, Mr Pfahlert said it pointed to a failure to learn lessons from an earlier contamination in 1998 and this was consistent with international experience.
"It is very common for institutional knowledge to get lost through staff and organisational changes, and that's something that all councils and water service delivery organisations need to be more mindful about."
He said criticism in the report of the performance of both regional and district council staff and those within the DHB highlighted the need to ensure that staff were appropriately qualified and trained to manage drinking water systems.