Water Treatment Plant Upgrades

Final Update

Tararua District Council has upgraded three water treatment plants situated in Dannevirke, Woodville and Eketāhuna.

The primary motivation for getting these projects underway and completed was the concern regarding the quality of the water during adverse weather events such as heavy rain and storms and these events could cause the water quality to not always meet the New Zealand Drinking Water Standards and consequently a Boil Water Notice would be issued under such conditions.

In response to this challenge, each of these plants underwent a unique upgrade tailored to address their specific concerns and these upgrades involved multiple layers of work that required careful coordination and execution.

The collaboration between Tararua District Council and Filtec has been instrumental in ensuring ongoing compliance with the New Zealand Drinking Water Standards.

These three water treatment plants have been running successfully without any concerns since the upgrades.

Dannevirke Water Treatment Plant

The Dannevirke site upgrade consisted of a migration to a new Supervisory Control And Data Acquisition (SCADA) system that would allow better control and monitoring of the upgraded plant. The allowance for this new technology means we will now be able to have the consistency of control, monitoring, and reporting. A new filter system was implemented that would allow raw water incoming into the plant to be cleaned thoroughly using the new filter systems.

Woodville Water Treatment Plant

The Woodville site was installed with a new Floc tank clarifier. The clarifier allows for solid particulates or suspended solids from liquid to be removed. The process of this allows for raw water that comes into the plant to have a more detailed filter down method of cleaning before it goes out to the community.

Eketāhuna Water Treatment Plant

The Eketāhuna site was installed with a new Flock tank, clarifier, and sludge tank. With this new equipment installed it has allowed for raw water coming into the treatment plant to be cleaned, filtered out before it enters the water systems in the community. The new sludge tank has enabled for sludge to be removed from the clarifiers and then sent to a sludge holding tank.

Tararua District Council is upgrading its water treatment plants in Dannevirke, Woodville and Eketāhuna. These essential improvements are aimed at enhancing drinking water quality in order to meet the New Zealand Drinking Water Standards supporting the district’s water treatment plants to meet future demands.

The infrastructure work is being done through a collaborative model between the Tararua District Council and Filtec water treatment specialists, which has been coined the Filtar Alliance. This partnership is based on the principle of having a single delivery team which shares risks and responsibilities and aims to deliver the best outcomes for the Tararua District.

The upgrades are funded through the Department of Internal Affairs Three Waters Stimulus Grant, as part of Central Government’s broader Three Waters Reform programme, which is now moving at pace. In 2020, council was successful in securing $5.02m for investment in three waters (water, wastewater and stormwater).

The combined cost of these water treatment plant upgrade projects is estimated to be $3.2 million. The remaining funds from the stimulus grant will be used for further assessments, planning and improvements to water and wastewater infrastructure.

Civil work on the water treatment plants started in June 2021 and is expected to be completed around October 2021 for Dannevirke, November 2021 for Woodville and March 2022 for Eketāhuna.

Plant History:
Woodville’s plant was built in the 1960’s and received its last major upgrade in 2010, while Dannevirke’s plant was last upgraded in 2016. In Eketāhuna, residents are experiencing discolouration in the water and this upgrade will install equipment that can manage that.