pH Control: Supporting on Auckland's North Harbour 2 Watermain

Auckland's water network is growing. The North Harbour 2 (NH2) watermain project is one of the most significant pieces of water infrastructure currently underway in New Zealand, and Condor has been on the ground supporting March Cato to keep the reinstatement work moving cleanly and compliantly.

The Project

Watercare's North Harbour 2 project involves the construction of a 33km watermain to service a population increase of 200,000 people across north and west Auckland. The project will provide both growth capacity and long-term resilience for the region's water supply.

March Cato was engaged to carry out Cement Lined Steel (CLS) pipe reinstatement works at Watercare's Northern Interceptor Park in Hobsonville as part of the early works phase of the programme.

The Challenge

A section of CLS pipe on this project had been sitting out of service for approximately three years. Over that time, the water inside had developed a significantly elevated pH level. At that pH, the water inside the pipe couldn't simply be discharged to site or stormwater without treatment first, doing so would breach discharge consent conditions and risk environmental harm.

Before reinstatement works could proceed, that water needed to be treated and brought within an acceptable pH range for discharge.

The solution needed to be fast to mobilise, effective at managing the volume of water involved, and reliable enough to keep the job on programme without any compliance risk.

The Condor Solution

Condor deployed the XXL Water Treatment System to manage pH stabilisation on site throughout the reinstatement works.

The Condor XXL is built around a channel-shaped lamella clarifier system with multiple inlet and outlet configurations, making it well suited to flexible site setups where water quality and discharge compliance are the primary concern. On this project, the XXL was configured to receive and treat the high-pH water from the out-of-service pipe section, stabilising pH levels to meet discharge consent requirements before any water left the site.

The Outcome

The reinstatement works were completed with all discharge meeting consent requirements throughout the project. The high-pH water that had accumulated in the out-of-service pipe section was treated and managed efficiently, removing what could have been a significant compliance and programme risk for the team on the ground.

The NH2 watermain, once complete, will play a critical role in supporting Auckland's continued growth, providing a reliable, resilient water supply for communities across the north and west of the city for decades to come.

Condor is proud to have supported March Cato and Watercare in keeping this important project moving.