A return to chlorine-free water in Napier would take 22 years and cost $295 million if councillors decided they wanted to remove it, a report has found.
The addition of chlorine to Napier's water in 2017 after E. coli was detected in the city's pipe system has since become an ongoing political and social saga for its 62,000 residents.
The chlorine reacts with manganese in Napier's ageing pipe system, and prompts near weekly examples of "dirty" water flowing from taps.
Few areas of the city have been spared from the malaise and almost every councillor to be elected to Napier City Council in 2019 did so vowing to relook at whether it was possible to remove it.
In December 2019, the new council resolved to proceed with a review to consider the options for the future of Napier's water supply, comparing the option of an enhanced system with chlorine disinfection against a safe chlorine free alternative.
The review Involved consultants across four countries as well as Napier City Council staff and began in June 2020.
The report, produced by Pattle Delamore Partners will be presented to councillors at the Sustainable Napier Meeting next Thursday, 25 March, an NCC spokersperson said.
In it are the two "most practical scenarios" for chlorine free Napier water, plotted over a 20-year timeframe to compare the options' costs against each other.
The report does not identify a preferred option but shows how the investment of the current Long Term Plan and an enhanced network are stepping stones towards a chlorine free future.
"The reviewers were not asked to provide a detailed cost analysis and have not undertaken design, however cost estimates indicate it will cost around $300 million over 20 years to achieve chlorine-free," a Napier City Council spokesperson said.
The review recommends a staged approach, to make sure the city's drinking water supply continues to be safe throughout these changes, over a number of years.
"There is no quick fix to enable Napier to return to chlorine-free in the short term," the NCC spokesperson said.
"For Napier to develop a chlorine-free supply that would be likely to meet the new regulator's standards, the network and its operation would require considerable enhancements, moving towards the advanced chlorine-free networks seen overseas."
If the decision is made to go to chlorine-free, it could take until 2041 and cost an estimated $284 million.
The options will be part of the Long Term Plan 2021-31 (LTP) community consultation process.
This will includes a public meeting, Facebook Live Chats and Book a Chat with councillors, initiatives to inform the community of the Review's findings and recommendations.
Napier Mayor Kirsten Wise said community feedback would help us the council decide what our next steps will be.
"Keeping the upcoming central government Three Water reforms in mind, the future of our drinking water supply is one of the most important decisions this council will make."
The main issues related to the review include: affordability, the ability of Council and industry to deliver the required work in a timely manner, and the new Drinking Water Standards NZ.
These standards, while not approved yet, may force Council to deliver temporary measures to meet compliance which may defer the network's long term development, an NCC spokesperson said.