Clarks Beach Wastewater Treatment Plant upgrade and outfall pipe

The latest

The team dedicated to the Membrane Aerated Biofilm Reactor (MABR) work has now commissioned the filtration tank which allows us to maintain compliance while we install the new MABR tanks.

Project overview

We have two interrelated projects underway for wastewater treatment improvements in Clarks Beach. This work consists of an upgrade to the existing wastewater treatment plant and the construction of a new outfall. Delivering this work allows higher quality treated effluent to be discharged effectively on the outgoing tide and minimises our impact on the local environment.

Wastewater Treatment Plant

Currently, the plant treats wastewater from about 2,500 people in Clarks Beach and Glenbrook. Our upgrade will allow it to treat wastewater for up to 6,000 people, which is expected to cover growth through to 2030. The upgrade involves us installing membrane aerated bioreactor technology (MABR) which together with UV disinfection, will significantly improve the quality of the treated wastewater leaving the plant.

Outfall

At the same time as the plant upgrade, we will construct a new outfall pipe to carry treated wastewater from the plant to about 100 metres off the coast in the Waiuku Channel. The outfall pipe will have the capacity to take the treated wastewater of up to 30,000 people, ensuring its fit-for-purpose for the long term.

• It will discharge only on the outgoing tide further lessening the impact on the environment.

• It will be constructed using a micro tunnelled tunnel boring machine and marine barges.

• The outfall and discharge were granted consent in 2018.

• Both the treatment plant upgrade and outfall construction will ensure we meet the conditions of this consent.

The works

Current and upcoming works

• Construction started in late August and is scheduled to complete in June 2026. The work is largely taking place within the current wastewater treatment plant site, however, there will be some works at at Stella Drive (our access into the site) and in the Waiuku Channel.

Week of 25 November

• Removing the median strip on Stella Drive to improve access for our vehicles. This work will take about one week to complete and will include the use of concrete cutters and excavators that will create some noise disturbance.

• Continuation of truck deliveries.

• Delivery of staff welfare cabins for staff use within the work site.

2-20 December

• Continuation of truck deliveries.

• Internal site works continue.

How will this affect you?

Working hours

• Most of the work will take place between 7am and 6pm Monday to Friday, with only limited works outside these hours.
• We continue to be in close contact with the Clarks Beach Golf Club around the scope and duration of the construction works.

Traffic management

• Will be in place for the work being carried out the week of 25 November.