Rāwene Electrocoagulation (EC) Plant Commissioning

Field Report:

Date: 05/10/2026 Prepared For: Carbon Neutral NZ Trust & Strategic Partners Prepared By: The Carbon Neutral NZ Trust Team (Inge Bremer, Rolf Mueller-Glodde, Moana Maaka).

1. Executive Summary

On 05/10/2026, the Rāwene EC Wastewater Treatment Plant was officially commissioned. The event, hosted by Te Mauri o Te Wai, was a resounding technical success. The EC machinery demonstrated immediate, clear effluent during its operation. Crucially, political, regulatory, and technical stakeholders were present to witness the operational viability of the EC modular standard, providing strong momentum for our upcoming annual plan strategies. The plant exemplifies a fit-for-purpose and environmentally sound solution for small, often remote communities.

2. Event Overview & Key Attendees

The early morning karakia and blessing at the Te Rāupo site was well-attended by decision-makers, proving the high level of regional interest in this pilot. Notable Attendees Included:

• Political/Regulatory: MP Huhana Jackson, NRC Chair Pita Tipene, FNDC Deputy Mayor Chicky Rudkin, Cllrs Tamati Rakena & Arohanui Allen, and Community Board Chair Jessie McVeagh.

• FNDC/Infrastructure: Tanya Procter (FNDC Infrastructure Manager), Martin Smith, and 3 Ventia staff members.

• Project & Community: Andreas Kurmann (Technical Anchor), Dallas King (Kaikōrero), Dr. Judy Reinken, alongside kaumātua, hapū, and community members, Darleen Tana as an observer

3. Technical Demonstration & Operational Outcomes

Andreas Kurmann and Dallas King led the demonstration, passing wastewater through the EC container and polymer addition unit. The visual proof of concept was immediate and compelling.

• Treatment Rate & Efficacy: When operating, the plant treats 6.5 m³ of wastewater per hour. This water is drawn from the last settling pond, and the process visually transforms it to clear effluent with settled flocculation in just 10 minutes. The process effectively destroys algae, bacteria, pathogens, and drugs via cell membrane electrocution, followed by coagulation and pressing into fertilizer.

• Targeted Daily Processing & Pond Management: Instead of overflow, 60 to 100 m³ of wastewater is targeted daily to be processed from the last settling pond. This actively lowers the pond's wastewater level by approximately 300mm. The EC system will operate intermittently, stopping once the target level is reached and resuming when enough wastewater has accumulated again. This ensures all treated water is managed for beneficial reuse.

• Energy Consumption: The electrical coagulation unit itself consumes 1.8 kWh for every 6.5 m³ of wastewater treated. Total daily power consumption, including ancillary pumps and valves, is currently being measured over a one-month period to establish a precise operational profile.

• Solar Integration: 64 kW will be installed uphill on the adjacent land to support the EC plant, which will significantly boost its energy independence and contribute to a highly sustainable, low-carbon footprint operation.

4. Strategic & Political Intelligence

Critical intelligence was gathered regarding the Water CCO transition and regional logistics:

• CCO Incorporation: The Far North District Council has formally agreed to join Northland Waters Limited (NWL).

• Funding: The "Better Off Fund," which financed this plant, is now depleted.

• Monitoring Plan: A dual approach will be used: 3 months of Western scientific monitoring running concurrently with Tirotiro monitoring (observing Maramataka phases and aquatic life behavior).

• Taipā Pilot Update: The Taipā trial is scheduled to start at the beginning of June, with no results or data expected before the end of June.

5. Next Steps

Following historical struggles regarding wastewater in the Hokianga (including the 2013 Rāwene issues and long-standing concerns in Opononi and Kohukohu), this pilot represents a major turning point.

• Community Observation: Te Mauri o Te Wai will invite various groups to see the EC plant running.

• Targeting the CCO: It was widely suggested to invite CCO representatives to view the plant, as the new entity will ultimately be responsible for water infrastructure.

• Media: RNZ has already run a short report, and Te Mauri o Te Wai captured extensive photographic evidence of the day.

Conclusion: The flawless technical demonstration at Rāwene directly answers the compliance failures of legacy systems, now with precise operational data. With the CCO agreement now formalised (on 20/5/26), we have the exact data and visual proof required to challenge the AP 2026/2027 budget plans and advocate for the EC modular standard as an immediate, sustainable, and affordable solution.