Beachlands WWTP discharge consent renewal

Project overview

The Beachlands and Maraetai communities are growing and our wastewater treatment plant (WWTP) is nearing the end of its design life. With the WWTP consent up for renewal on December 31, 2025, upgrades are essential to continue providing services and meet future demands. This includes exploring alternative wastewater discharge locations.

Options consideration

We engaged independent specialists to assess potential options for wastewater treatment quality and discharge locations. These options were evaluated using a clear methodology and various criteria, aligned with project objectives.

The project team identified 20 potential solutions, taking into consideration community needs and best practices globally. These were narrowed down to five short-listed options after community feedback on 26 October 2023 at Te Puru Community Centre. There were also online surveys for those unable to respond in person.

After careful consideration and evaluation of a range of discharge options, we have identified option 2a - a diffuse discharge to a tributary of Te Puru Stream, as the preferred technical option for the future discharge from the Beachlands Wastewater Treatment Plant site.

While option 2a is the preferred technical option, we remain committed to consulting with Mana Whenua, Ngāi Tai ki Tamaki, to further refine and develop this option for the discharge of wastewater from the Beachlands Wastewater Treatment Plant.

We appreciate the ongoing collaboration and input from all stakeholders as we continue to prioritise public health of the Beachlands and Maraetai community, environmental outcomes, cultural wellbeing, and the requirements of the community in our decision-making process.

Stages of implementation

Current wastewater treatment plant

The ongoing discharge of treated wastewater from the existing treatment plant without any upgrade works, with an average dry weather flow of 2,200m³/day, and a peak wet weather limit of 4,500m³/day. This will cater for a population of up to 11,000 people. The upgrade is expected to be completed within seven years of the consent being granted.

Stage 1

The stage 2 works will cater for a population of up to 18,000 people with an average dry weather flow of 3,600m³/day, and a peak wet weather limit of 21,700m³/day.

Stage 2

The stage 2 works will cater for a population of up to 30,000 people with an average dry weather flow of 6,000m³/day, and a peak wet weather limit of 36,200m³/day.

These upgrade works will allow for removal of suspended solids and most micro-organisms (bacteria, viruses etc.). UV disinfection will be retained and expanded to provide an additional level of treatment. Water will still be discharged into the tributary of the Te Puru Stream via groundwater and an overland flow system.

The long-term upgrades are population dependent and will only be implemented once the referenced population numbers are reached.

A hearing date for the application has been confirmed for November 5 to7, 2025. A decision is expected by the end of 2025.