A mix of options for upgrading the security of Christchurch’s groundwater supply will be pursued so the city’s drinking water can return to its natural, unchlorinated state as soon as possible.

Yesterday, the Council approved that well heads should be raised above ground wherever practicable.

It also agreed that staff should examine options for installing UV treatment at a number of pump stations where the Council may not be able to get secure status or while new wells are drilled or remediation work is done.

Converting most of the below ground wells to above ground and integrating some UV treatment into the water scheme gives us the best chance of returning to an unchlorinated water supply in the long term. Above ground well heads offer a better safeguard against possible contamination, are easier to access for maintenance and converting them gives us a better chance of gaining an exemption should the government make treatment mandatory.

We’re now working on the detail to establish what will work best for each well head and will be reporting back to Council next month with a draft programme.

A few people have been getting in touch saying their skin is irritated by the treated water, particularly those who have eczema. We went to Medical Officer of Health Dr Cheryl Brunton for some expert advice.

Dr Brunton explains that people with eczema often experience flares or exacerbations due to changes in the environment, particularly exposure to things that tend to dry the skin out.

Some people will have eczema that gets worse at this time of year due to seasonal changes.

For some people with eczema, they might find bathing in chlorinated water tends to dry their skin out or irritate it.  If that’s the case they need to use plenty of emollient cream and treat any flare up of their eczema as they would usually do.  If it gets worse, they should see their GP or skin specialist.

The problem may get better with time.  At the moment, as chlorinated water comes through pipes (including those in the home) which may have biofilms on them, there will be some by products in the water (like chloramine) which could affect some people’s skin – the amounts of these by products will reduce over time.

Dr Brunton says there isn’t any evidence that eczema is more common in cities and towns with chlorinated water supplies.

As temporary chlorination is implemented at each pump station, we're testing the water to make sure that chlorine doses are at the appropriate lowest possible level.

We’ve had a few people contact us complaining of a strong smell. While in some areas the initial doses have been slightly elevated, testing shows we are well below the allowable limit. We will continue to monitor and adjust the dose rate as we progress.

We expect any smell and taste issues to reduce as the chlorine comes into full effect and suggest people put a jug in the fridge for drinking as the smell and taste will reduce over time.

There is background information and a map on our website showing areas of the city where chlorine is being used and this will be updated as we progress. There is also a question and answer section on the Council website.

You can call the Customer Contact Centre on 03 941 8999 or 0800 800 169 if you have any questions, or email watersupply@ccc.govt.nz