Hikuai–Pauanui Wastewater Project

Located on a 23.8 ha site in a breathtaking valley nestled among cascading mountains, the development required a centralised wastewater system due to land constraints and environmental sensitivity. The FlowX Integrated Wastewater Treatment System was selected, incorporating MBR, MABR, and MBBR processes to achieve high-efficiency treatment within a compact footprint.

The development comprises 47 residential lots where individual wastewater systems were not feasible due to limited disposal land area and environmental constraints. The system ensures compliance with New Zealand standards while achieving higher treatment efficiency, water reuse, and community acceptance.

Scale

• Site area: 23.8 hectares

• Lots: 47 four-bedroom dwellings (design occupancy: 282 residents)

• Design flow: 33,840 litres/day

• Treatment capacity: 2 × 50,000 litre/day FlowX MBR modules

• Drain field area: 1,691 m² (reduced footprint vs conventional systems)

Benefits

Advanced Treatment – High removal of BOD, TSS, nitrogen, and phosphorus using MBR, MABR, and MBBR processes, producing crystal-clear effluent.

Reuse & Recycling – Treated water reused for toilet flushing, irrigation, and landscaping; nutrients recovered to support community greenhouse cultivation.

Compact & Scalable – Containerized modular units enable rapid installation, minimal land use, and future expansion flexibility.

Environmental Protection – Reduced discharge volume, minimized groundwater risk, ozone disinfection, and odour control systems.

Community Integration – Greenhouse doubles as a water polishing system and community green space, improving social acceptance of recycled water.

Circular Economy – Onsite sludge drying and pyrolysis convert biosolids into biochar for landscaping, reducing landfill dependency and closing resource loops.