Eketāhuna Wastewater Treatment Plant Upgrade

The Eketāhuna Wastewater Treatment Plant (WWTP) is undergoing significant improvements to improve the water quality discharge to the Makakahi River. Led by Tararua District Council (TDC), this project focuses on addressing issues of excess stormwater and groundwater inflow, also known as Inflow & Infiltration (I&I), that places strain on the wastewater system, especially during heavy rainfall. By reducing I & I and upgrading the plant, we aim to make Eketāhuna’s wastewater system fit for purpose, more efficient and more environmentally friendly.

Project Goals

  1. Compliance with Environmental Standards: Ensuring treated wastewater meets regulatory requirements.
  2. Managing Stormwater & Groundwater Inflow: Reducing stormwater entering the sewer system to enhance treatment efficiency.
  3. Collaboration with the Community: Engaging with local iwi, Horizons Regional Council, and residents to achieve shared goals.

Project Phases

  • Pipeline to Wetland: Re-routing water from Pond 2 to the wetland to firmly establish wetland plants and to collect vital discharge data to aid in new plant selection.
  • Inflow & Infiltration (I&I) Reduction: Targeting high inflows of stormwater and groundwater that can overwhelm the system.
  • Upgrade Wastewater Treatment Plant: To upgrade plant according to collected data from wetland flow and the percent I & I reduction achieved in phase one. New inlet screens will be part of this upgrade.

Why This Upgrade is Important

The existing Eketahuna WWTP faces challenges with water quality and high stormwater inflows, particularly during wet weather. By addressing these issues, we can:

  • Reduce the environmental impact on the Makakahi River.
  • Enhance the plant’s resilience and reliability, ensuring it serves the community effectively.
  • Fulfill consent requirements, improving water treatment practices in Eketahuna for the long term.

Inflow & Infiltration (I&I) Reduction Program

The I&I reduction effort is a multi-step approach to managing stormwater & groundwater that enters the wastewater network through cracks in pipes, manholes, and private stormwater connections. When stormwater and groundwater seep into the system, it increases the volume of water needing treatment, placing unnecessary pressure on the plant.

The program includes:

  1. Network Inspections: Using advanced tools like cameras and smoke testing to identify weak spots in the system.
  2. Focused Remediation: Based on findings, TDC will carry out targeted repairs on the public network, & consult the community on recommended fixes required for the private network, to fix damaged pipes, manholes, and other inflow sources.
  3. Collaborative Efforts: Working closely with residents to address private stormwater connections that contribute to I&I.

By reducing I&I, we not only protect our waterways but also create room for future growth in Eketāhuna’s wastewater system without needing significant expansions.

Timeline and Updates

  • Mid-2024: Pipeline and inlet screen upgrades start.
  • 2025: Major plant upgrades begin.
  • Late 2027: Project completion.