Alternative wastewater system switched on at Rāwene

A significant switch in the treatment of wastewater at Rāwene was activated earlier this month when the electro-coagulation (EC) unit – an alternative system for treating wastewater – was turned on.

The goal of Te Mauri o te Wai, the community liaison group for the Rāwene Wastewater Treatment Transformation Project, is to achieve wastewater that is clean before it is dispersed into the Hokianga Harbour and Ōmanaia Awa.

Members of the hapū-led group – which includes hapū and community members who worked alongside council staff and contractors – were at the early morning ceremony along with elected members from the Far North District Council and Kaikohe-Hokianga Community Board.

The ‘symbolic’ blessing marked the beginning of the commissioning phase, which involves fine tuning mechanical processes of the EC unit to ensure they are working well. Several months of testing will be carried out to compare previous discharge data and to clarify operating costs.

The blessing also included naming the EC unit Puhi te Aewa.

Electrocoagulation (EC) is a process using electricity and iron plates (electrodes) to separate water-soluble contaminants in the wastewater. These contaminants - like phosphorus, nitrate and ammonium - are not visible. The system works by coagulating contaminants and making them easier to remove from the water.

The council was granted ‘Better Off’ funding in 2022 to work with Te Mauri o Te Wai to transition from the existing wastewater discharge system to a more effective, culturally appropriate treatment solution that significantly reduces environmental contamination and supports long-term resilience and community outcomes.

While the EC system is used in a variety of wastewater and industrial processes overseas, it has not yet been used on municipal wastewater systems in Aotearoa.

Find out more about the Rāwene Wastewater Transformation Project here.

Main photo - credit to Te Mauri o te Wai.