Rebecca Harper, who also lives in one of the flats, said she was worried about how the irrigation might effect the bore and her vegetable garden, which backs on to the land the council proposes to irrigate: "Why can't they think of somewhere else? There must be other areas."
The council has proposed a tightly planted continous screen planting 10-15m from the boundary to provide a barrier between the irrigation site and the flats.
Peter Rewi of the Papawai Mangarara Stream Restoration Group and the Papawai Marae Kaumatua Housing Trust said the screen planting was not a good idea.
"You can go and put some poplars or whatever there but, hang on, these guys get the winter sun so planting trees is not a viable plan."
The upgrade is planned in four stages, with the final stage, which would see full land treatment except under special circumstances, due to begin no later than 2041.
Mr Rewi said he supported the council's move to reduce discharge to waterways, but it was disappointing it had applied for a 35-year consent.
"What we are disappointed in is the length of time and the fact that there's still going to be discharge to the Papawai Stream for the duration of the application ... we are disappointed that while we've improved the flow of the stream and we've cleaned the sides of the stream, that they still want to put things into the stream.
"And we don't believe that there's enough attention paid to land flooding and what happens in the case of flooding."
Another concern was that the irrigation site bordered the urupa, Mr Rewi said.
However, Michael Roera, of the South Wairarapa Maori Standing Committee, said the group had been in negotiation with the council and accommodations were being made. The screen planting would be limited to 5m high, and water and soil quality would be regularly monitored, Mr Roera said.
But the duration of the consent should be limited to a much shorter period, he said.
"It's too long. If we get improvements then we want that put in."
Under the Wairarapa Combined District Plan, the irrigator could be no closer than 20m from the boundary with the flats, council chief executive Paul Crimp said.
"While the exact irrigation type has not been completely decided but will in all likelihood include pivot-type systems.The pivot irrigators are modified so that the droplets being discharged are quite large and less likely to be either carried very far in the wind or subject to becoming very small spray droplets."
The ultra-violet treatment meant there would little, if any odour, and screen planting would be done in a way to ensure sunlight reached the flats, he said.
Spreading the upgrade across 35 years reduced the impact on ratepayers, Mr Crimp said.
"The 35 years is required because we have to manage the discharge across the three towns, and the get the best environmental outcomes, we need to have a staged approach for each town."
Monitoring systems would be able to detect any contamination of bore water, which was not expected.
The upgrade to all three plants is expected to cost about $29 million.
The council's application for the Greytown consent is still being considered by the regional council, with a date for a public hearing yet to be set.
