The $1 million upgrade to Mamaku's water supply infrastructure is now complete.
The upgrade work was undertaken to add ultra-violet light treatment as an additional treatment to chlorination, which will now be consistent with Rotorua's nine other water supplies.
The work also ensures all Rotorua's water supplies are now treated to give communities the highest possible drinking water quality under the Drinking Water Standards for New Zealand.
Other work that took place during the upgrade included replacing one of the existing bore pumps and adding extra filtration devices and water-quality monitoring equipment.
Rural Community Board chairwoman Shirley Trumper said it was good to know all 10 supplies within the district would now be doubly protected with chlorine and ultra-violet light.