Yesterday Greater Wellington Regional Council approved $6 million to restore fluoride to residents and upgrade facilities.
The money will fund two new fluoride facilities to be located at Te Marua and Gear Island treatment plants.
As of early May, Jenkins had completed 30 interviews and reviewed more than 400 documents as part of the inquiry.
He was commissioned to review events that resulted in Wellington Water stopping fluoridation at the two water treatment plants, and why the organisation didn't communicate this in a timely and accurate manner.
"The inquiry is a vital step in understanding how this situation occurred. While the delay is not ideal, it's important we get this right. This takes time and the board is prepared to accept a small delay in the interests of receiving an in-depth report and recommendations," Carroll said.
"This inquiry is very important to Wellington Water as it will provide us with clarity on next steps and provide the public with assurance that this situation will not occur again."