The Dunedin City Council plans to start work on the $2 million Waikouaiti water treatment plant upgrade on September 22, and a "boil water" notice will be in place from then until January 12 next year, when it is hoped the work will be finished.
Residents appear to vary in how seriously they take the notices, but the Karitane School will not let children drink from its water fountain when a notice is current, and has applied for funding for its own filtration system to deal with the problem.
Cr Andrew Noone said the four months was "a short-term sacrifice for a long-term gain".
Council water operations team leader Gerard McCombie said water had to be boiled as a precaution during the upgrade because it would be chlorinated, but not filtered.
The tender for the work had gone to Filtration Technology Ltd.
It would involve removing old filters and replacing them with new membrane filters, and work on chemical dosing equipment used to assist the filtration process, adjust the pH level, and make sure water from the plant was as non-corrosive as possible.
There would also be new pumps, pipes and electrical systems.
The work would be subject to Ministry of Health assessment, Mr McCombie said.
Karitane School teacher Helen Carter said boil water notices had been a regular experience for residents whenever there was heavy rain.
Residents were split into three "camps": those who always boiled their water when notices were in place, those who "just don't care and drink it anyway", and those who believed they had developed immunity from drinking the local water.
People were sceptical of the new scheme, as they had lived with poor quality water for so long, she said.
But Mr McCombie said the area would get a "very, very high quality water" once the work was done.
