Lincoln, Prebbleton, Rolleston and Leeston are set to get the plants later this year or next.
Rolleston already has one plant operating using UV technology and another is planned.
District council water services team leader Cinnil Thomas said the upgrades will help to meet or exceed new guidelines.
“New Water Safety Plan guidelines that came into effect in May encourage a multi-barrier approach for water treatment. These projects and others are being delivered in accordance with these requirements,” she said.
“UV treatment is an effective method used for water treatment using ultraviolet light for disinfecting bacteria. It is a standard method that is widely used around the world. The UV rays attack the genetic code of harmful pathogens rendering them unable to reproduce.”
The budgeted costs for the plant on Vernon Drive and UV treatment for the Lincoln supply is $373,000 and is expected to be completed in June next year.
The same cost has been allocated for the Prebbleton township supply, the plant will be built on Shands Rd and will be completed in October next year.
The Leeston water treatment plant on Leeston Dunsandel Rd is expected to be finished in January and will cost $375,000.
The cost for UV treatment for the Rolleston town water supply is part of the total budget for the work planned at Helpet Park.
As well as improve water quality, the plants will also provide additional storage as population numbers in the district continue to rise.
The work is a part of a $6 million dollar plan to upgrade water supply treatment plants across the district to meet or exceed drinking water standards between 2018-2021.
Environment Canterbury chief scientist Tim Davie said the advantages are that it doesn’t leave a taste in the water and is relatively inexpensive.
“A disadvantage, compared with chlorination, is that it only treats in one place so if there are further risks as the water goes through the network then it isn’t covered,” he said.
Waterways Centre for Freshwater Management director Jenny Webster-Brown said the key to beneficial UV treatment is a good reticulation system.
“If you have a good reticulation system that is secure then UV is fine but if you haven’t it can be quite risky and leave water sources without protection,” she said.
