Published 26/02/2024
Wellington Water working to achieve chlorine compliance
Wellington Water is working with Greater Wellington and Hutt City Council on upgrades to make sure water from the Waterloo Treatment Plant is compliant with new rules set out by Taumata Arowai, the national water services regulator. The new rules require water from the treatment plant to have longer contact time with chlorine through the treatment process than was previously required, to further reduce the risk of bacteria.
Chlorine guards against the risk of treated water becoming contaminated within the supply network as it flows from the treatment plant to households and is a precaution against the slim possibility of contaminants getting through the treatment process.
“It is important to note that the water being supplied from the Waterloo Water Treatment Plant is still safe to drink,” says Tonia Haskell, Wellington Water’s Chief Executive, adding the plant was compliant under previous rules, and it is only recently when the rules changed that it stopped meeting the chlorine rules.
An independent technical study completed in early 2022 shows the current water treatment process at the plant is effective but can be further improved by increasing the contact time, which we are working towards. Wellington Water submitted this report to Taumata Arowai and asked for an exemption from the chlorine contact rule in March 2023, while the upgrade work was underway. However, the exemption request was declined in January 2024.
The upgrades to the drinking water network will ensure the water from Waterloo is compliant.
“Once the upgrades have been completed, drinking water from the Waterloo Water Treatment Plant will be in contact with chlorine for the required amount of time to meet the new rules. Until then, the plant will not be compliant with the new rules.”
There are currently a number of homes in areas near Epuni Street and Tilbury Street in Lower Hutt that are receiving water that does not meet the new chlorine rule. It is estimated that this could affect up to 800 properties at most. We can’t identify exactly how many households are impacted because it depends on the way water flows through the network.
Some homes located near the Treatment Plant are connected to the water supply early in the network, which means the water they receive has not travelled through the network for a long enough period to have the right amount of contact with chlorine.
“We are committed to continuing to provide safe and healthy drinking water to the community. The upgrades are something we have been progressing for some time now. We will continue to work closely with our council owners and the regulator to make sure that this work is completed and that the Waterloo Water Treatment Plant achieves compliance.”
Some of the upgrades have already been completed with more due to start in July 2024. The full timeline of the work is still being worked through, and we estimate that it could take up to two years before we can achieve full compliance with the new rule.
Wellington Water will continue to keep the public, the regulator and its council owners updated as this work progresses.
Editor notes
Wellington Water is owned and fully funded by Wellington City Council, Hutt City Council, Porirua City Council, and Upper Hutt City Council, Greater Wellington Regional Council and South Wairarapa District Council. All six councils are equal shareholders.
Our councils own the water infrastructure in the region, and they task us to manage the infrastructure and deliver water services to our communities.
Wellington Water is governed by a Board of Directors. The Board and our organisation receive overall leadership and direction from the Wellington Water Committee, which are also responsible for appointing members to the Board.
The Wellington Water Committee is made up of representatives from our council owners and mana whenua.