Masterton and Carterton district councils are confident they will meet new water standards coming into force next year while work is underway in South Wairarapa to also achieve the new standard.
Last week, the government passed legislation aimed to transform drinking water safety and improve environmental outcomes for New Zealand's wastewater and stormwater networks.
The Water Services Act gives Taumata Arowai the legal authority to carry out its duties as New Zealand's dedicated water regulator.
Minister of Local Government Nanaia Mahuta said the passing of the legislation was "a major transformational advance" for the health and wellbeing of Kiwis.
About 34,000 people across New Zealand became ill from their drinking water each year and many thousands of households in different regions must boil their water to drink it safely, she said.
Taumata Arowai has been established to ensure there is consistent regulation and enforcement to minimise these risks.
In the most recent Ministry of Health report on drinking water, which covered the 2019-20 year, it was revealed that Carterton and South Wairarapa did not meet the current standards.
At the time the report was published, work was already underway to fix this in both districts.
But Taumata Arowai standards are much more stringent than the existing ones.
Last month, it was revealed that even though Martinborough's Water Treatment Plant meets the current Ministry of Health standards, it fails to meet 72 of 79 draft standards set by Taumata Arowai.
The Martinborough Water Treatment Plant was used as a "test case" by Wellington Water to indicate what work may be required to bring water assets up to new standards.
South Wairarapa District Council [SWDC] chief executive Harry Wilson said he had asked Wellington Water to plan improvements that would transition SWDC's water assets to meet the new standards.
"It is expected there will be a transition period, as with most new standards," Wilson said.
"As at April 2022 we may not comply fully - such large scale changes take time, but we would have made a good start."
The Greytown and Pirinoa Water Treatment Plants were undergoing a programme of work to meet the requirements of the current standards.
In Carterton, the council's infrastructure, services, and regulatory manager Dave Gittings said any changes to comply with the new standards would be related to monitoring and reporting, "rather than any major infrastructure changes".
"The final changes to the compliance rules will likely mean we will have to alter the computer setting frequencies of some of our online recordings and increase the number of physical tests.
"We may also need to install more constant monitoring electronic testing stations - we currently have two already - into the reticulation system.
"We are in a fortunate position in Carterton in that we already have a double barrier to disinfection with the use of chlorine and UV and have had this for some considerable time.
"Our basic infrastructure is in place to deal with the changes that have been signalled."
A Masterton District Council spokesperson said Masterton's water had "consistently met standards in the past, and we are confident we have the equipment and processes in place to meet the new standards".
The next step in the government's response to increasing the quality of water in New Zealand was to look at the operation, management, and service delivery of water systems to ensure all communities are able to meet the costs of compliance.
Local Democracy Reporting is a public interest news service supported by RNZ, the News Publishers' Association and NZ On Air.