Christchurch is one of the largest cities in the world that does not need to treat its water to make it safe for drinking.
* Health board and fish owners prepare for Christchurch chlorination * Chlorine taste unlikely in Christchurch’s treated drinking water, council says * Christchurch drinking water to be chlorinated for a year as councillors approve plan to keep it safe * Goldfish die after town supply water added to pond But amid a reappraisal of drinking water standards last year engineers found parts of the supply network were not up to scratch.
How does chlorination work – and will I taste it?
The solution reacts with organic matter and in the process gives off a chlorine taste.
"Chlorine might be noticeable at the beginning of the treatment because it does react with any organic matter in the network or even on the end of your tap," Adamson said.
So there is a chance when we first turn it on that you will get a taste – the organic matter reacting with the chlorine.
Running a tap will flush through any organic matter that chlorine has reacted with in household pipework, and leaving a jug of water in the fridge overnight will help get rid of the taste.
How fast it evaporates depends on the shape of the jug or bottle.
The Ministry of Health also says no side-effects have been found from long-term exposure to chlorine in drinking water and dismissed studies linking it to cancer as having insufficient data to show the levels required to cause such risks.
The temporary chlorination is expected to cost $600,000 to set up and about $250,000 a year to run.