"We know we have great water quality here in Rotorua but this added treatment means Mamaku residents will have water that is treated to the highest quality.
"We hear about things happening around the country but it's good to know that council is vigilant in protecting our water quality and that all 10 supplies within the district will now be doubly protected with chlorine and ultra-violet light."
Trumper said there may be some disruptions while the work was taking place but having top quality water would be worth it.
The council said work would also be carried out to replace and upgrade other parts of the treatment facility including replacing one of the existing bore pumps and adding extra filtration devices.
Additional and replacement water quality monitoring equipment is also included in the upgrade.
Infrastructure General Manager Stavros Michael said the work would help to future proof Mamaku's water supply.
"We want to be confident that we supply high quality drinking water and that we can continue to do so should a breakdown happen at one of the bores which supplies water to Mamaku residents.
"Under the Health Act Councils must take all practicable steps to ensure that supplied drinking water is safe and the added ultra-violet light treatment means both of Mamaku's bores will be fully compliant with the Drinking Water Standards for New Zealand," he said.
Work is expected to take place over a couple of months and will require the water supply in Mamaku to be shut down on two occasions.
The first shutdown will take place from 9am to 4.30pm on Tuesday September 4 and residents will receive notification in their letter boxes.
The second shut down has not been scheduled yet but residents will be notified in advance.
For more information about the Mamaku water supply and what to do during the shutdown click here.