Delivering a design solution that dealt with a challenging operating environment and multiple, complex stakeholder relationships

Watercare Māngere CFT Tank – Wastewater Treatment Plant

The Māngere Wastewater Treatment Plant receives and treats wastewater collected within the Auckland metropolitan region. The operators, Watercare, engaged our team to support the upgrade of two centrifuge feed tanks (CFT) and the installation of a new packaged odour treatment plant to service the CFTs. CFTs are a key part of the process that store digested sludge prior to dewatering using centrifuges as stored digested sludge has the potential to release biogas.

Our team provided design services including structural (new independent walking platforms above the CFTs to eliminate additional maintenance loads on the tanks, DN300 odour duct supports, and a reinforced concrete slab onto engineered fill which the packaged odour treatment plant is installed), electrical (the power supply) and control and instrumentation (integrating packaged odour treatment plant to Watercare’s existing site services). A hazardous area classification reassessment was completed on the CFT and Armatec designed, constructed, and installed the packaged odour control plant.

Many of the design and integration challenges that arose were related to the operation of the CFTs—our goal was to integrate the Armatec installed odour control plant, to satisfy compliance standards, and minimise risks without creating an over-engineered solution. The odour control plant was installed and is currently being commissioned with anticipated operation resuming shortly.