The Chlorine Exemption Process

The new drinking water regulator Taumata Arowai took over from the Ministry of Health in November 2021 signalling a new era for water safety standards.

Under the new rules, all public supplies are required to have treatment such as Ultraviolet (UV) at the headworks, but also a residual disinfectant in water that leaves the plant. All suppliers of water need to have a Drinking Water Safety Plan (DWSP) in place as well as residual disinfectant, such as chlorine - unless awarded an exemption.

The Council believes our District has water of the highest quality and therefore we have submitted six applications seeking exemptions from having to use chlorine in our urban supplies of Rangiora, Kaiapoi, Woodend-Pegasus, Oxford Urban, Cust and Waikuku Beach. Exemptions are not being sought for restricted schemes as these have always been chlorinated due to the risks inherent with rural schemes - including us not being able to guarantee water safety of private tanks.

As a Council we have always been in favour of the new regulator (despite our opposition to the forced four-entity model of Three Waters) and welcomed new regulations.

Having secure and safe water is important for the health of our community and we want to meet the challenge of new regulations.

Our Planned Upgrades

The Council met with Taumata Arowai officials, including their Chief Executive, on two occasions to reiterate our programme of investment and the fact our residents want to have unchlorinated water.

The regulator listened and while we are waiting for our applications to be assessed, Taumata Arowai has allowed the Council to continue running unchlorinated water supplies on the basis that more regular testing is undertaken and a programme of work is brought forward, which will increase the safety of supply. A key part of this decision was also that the Council has emergency chlorination systems in place, which are ready and able to be used at a moment’s notice.

While we believe we have some of the safest drinking water in the country, the bar for unchlorinated supplies has never been higher. Despite being able to continue operating unchlorinated schemes without a residual disinfectant we are expected to use emergency-chlorine in response to even low-level detections of organic material – as we have recently experienced in Kaiapoi and Woodend.

As well as planned and budgeted UV upgrades, we are also undertaking a programme of reservoir upgrades across the District. To allow these upgrades to take place in a safe manner, chlorine will need to be used. This means for schemes such as Kaiapoi and Woodend, chlorine will remain until upgrades are completed - approx July or sooner if possible.

When We Must Use Chlorine

When we are using chlorine we are doing so at exceptionally low rates. In Kaiapoi for example we are using a rate of 0.5 parts per million (a concentration of about 0.00005%), which is a tenth of the maximum allowable level. This is well within the healthy level for drinking water, recognised internationally, and we are highly confident about the safety of the water.

Despite this low dose rate, the taste can be noticeable when chlorine is first introduced (until the system stabilises) and we appreciate that this has caused concern for many residents.

Waimakariri is one of the few areas nationwide that doesn’t use chlorine and given this, it’s not surprising that a lot of residents have questions about it. We have put together answers to some of the frequently asked questions at waimakariri.govt.nz/chlorination.

Working Through a New Process

Residents have been clear that they do not want chlorinated water and the Council is doing everything we can to ensure that happens. We have made sure that the community’s views with respect to chlorine are known to Taumata Arowai.

However, the decision to chlorinate or not will be decided by Taumata Arowai’s assessment of our applications.
What makes this process challenging is that there are no clear pass/fail criteria established. As a Council we respect that this is a new process, with a new regulator, interpreting new regulations and it will take time to work through.

We are working closely with neighbouring councils who are facing the same challenges and going through the same exemption process as us. We are also working constructively with Taumata Arowai.

The required increased testing, and fast-tracking of UV treatment projects already underway doesn’t guarantee a successful outcome of the exemption process.

We will know more about the exemption process around mid-year. For many we know the lack of a concrete timeframe has been frustrating and the Council is doing everything we can to provide residents with certainty as soon as possible.

Ultimately, chlorinating supplies, as well as undertaking further upgrades, may be something the Council is directed to do (rather than decides to do) due to new and higher standards. We are doing everything we can to make a case to allow our water supplies to remain chlorine free, despite the additional challenges in place for us to do this.

Find Out More

We will let you know when we have updates about each chlorinate application. We will also keep our website updated with the latest information at waimakariri.govt.nz/chlorination.

In addition to the drop-ins feel free to get in contact should you have any questions on 0800 965 468 (0800WMKGOV) or email office@wmk.govt.nz.

Drop-in Sessions

We will be hosting drop-in sessions so you can ask questions about this process and learn more about water supplies across the District.

Cust
Monday 1 May
5 – 7pm
Cust Community Centre

Kaiapoi
Tuesday 2 May
6.30 – 8pm
Kaiapoi Borough School Hall, 20 Hilton Street, Kaiapoi

Woodend
Wednesday 3 May
6 – 8pm
Woodend Community Centre

Rangiora
Monday 8 May
5 – 7pm
Rangiora Service Centre: Council Chambers