Water at a number of pump stations supplying suburbs across the city is now being treated, and we’ll be adding more stations within these zones in the next few days.

To find out if where you live is included, check out the map on our website.

Treatment has started at several pump stations in the northwest zone, which stretches from Belfast through to Yaldhurst and includes parts of Riccarton and Addington and supplies 80,000 people. We’ll be treating the remaining pump stations in this zone as well as any remaining ones in Sockburn, Wigram and Hornby (the west zone) in coming days.

We’re also planning to begin the rollout of chlorination in Parklands and other parts of the city from this week.

We're aiming to have started temporary treatment of all Council water supplies by the end of April.

Investigations are under way into whether it is better to convert some below ground well heads to above ground and treating with UV while upgrade work is done.

This will future-proof the network and boost the likelihood of the city’s water returning to its unchlorinated state in the long term.

This solution won’t be able to be done at all pump stations and is likely to take longer.

In a report to the Infrastructure, Transport and Environment Committee, we’re looking for guidance on options to allow us to return to having an unchlorinated water supply.

Our preferred option could include installing UV treatment for a number of pump stations where the Council may not be able to get secure status, or as a medium term option while new wells are drilled or upgrades done.

The advantage of UV treatment is it doesn’t affect the taste or smell of water —most bottled water is treated this way. It can be more expensive to implement UV treatment, and unlike chlorine, it doesn’t provide protection beyond the site where treatment occurs. However where the installation of UV treatment replaces the need to upgrade a number of well heads it can be an economical solution.

We’re hoping to reduce the amount of time we need to chlorinate. With careful management of the various pump stations as well as limiting demand where we can, we may be able to provide enough unchlorinated water for the city.

It is intended to turn off the chlorine at individual pump stations as soon as they regain their secure status.

We’ve had a few people mention they've noticed a chlorine smell or taste in their water. This is caused when the chlorine reacts with biofilm in the pipes and we’d expect this to reduce over time.

For drinking water, you can put a jug in the fridge and the taste and smell will reduce over a couple of hours. We’re also monitoring dosage levels and adjusting where needed to keep the rate as low as possible.

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