Projects
Hutt Valley & Wainuiomata Wastewater Scheme
Owner
Hutt City Council
Location
Wellington, New Zealand
Date
1998 - 2002
Description
Servicing the residential suburbs and industrial areas directly to the east of New Zealand’s capital Wellington, this scheme is a DBO project. It encompasses a new 55 ML/d sewage treatment plant at Seaview; replacement of the old Wainuiomata treatment plant with new collection facilities, pump stations and 7.2 km delivery pipeline to Seaview; upgrade of several major pumping stations; 20 year operations of the new facilities plus the 74 km of sewers and 17 pump stations in the bulk wastewater network and an 18 km main outfall sewer to Pencarrow Head, where the treated effluent discharges to the Cook Strait. The innovative design of the new treatment plant takes full advantage of the limited available hydraulic profile to avoid the need for inter-stage pumping in the liquid stream processes. Residuals are thickened, dewatered and granulated in a thermal dryer. This represented the largest infrastructure project undertaken by Hutt City Council at the time, and the contract was let to a consortium of Bovis Lend Lease, CH2M-Beca and NZ Water Services.
Role
Nick Read was the project’s Engineering Manager from the bid phase onwards and throughout the life of the project, culminating in process commissioning and performance testing. Nick has also returned to the project on occasion to assist with additional elements brought into the scheme and review long term sustainability of some the ‘inherited’ assets.