This work was commissioned by the Whangarei District Council following frequent overflow of sewage into an urban stream during heavy rain events. The pump station upgrade and new emergency storage tank were designed to reduce these overflows and provide primary treatment and disinfection capability in the event of an overflow.
Whangarei District Council faced an ongoing problem with sewage overflows into the upper reaches of the Hatea River following heavy rainfall. An upgrade to the Hatea Sewer Pump Station and the construction of a large emergency storage tank at this location was designed and engineered so as to minimise overflows and ensure appropriate treatment and disinfection capability in the event of any future overflows.
At $1,200,000, the value of tank, pump well and control building construction works undertaken by Paneltech amounted to around 30% of the overall project value.
Paneltech took responsibility for the design and construction of structural components of the project, with the dimensions and design loadings specified by the owner (Whangarei District Council). Design considerations included resistance to the corrosive nature of sewage, buoyancy forces and lateral earth and ground water pressures. Site access was difficult and construction methodologies needed to give careful consideration as to how the large precast components could be safely lifted into position.
Paneltech’s works included the construction of a 1,000,000 litre concrete tank along with a deep wet well, weirs and other sumps, a timber framed control building and various ancillary works. The structures were built up to 7m below ground level.
Paneltech cast the floor slab in-situ, then erected precast panel walls (including a central wall), and unispan roof sections, which were finished with a 400mm reinforced topping slab.
The Hatea Sewer Pump Station Upgrade and Emergency Storage Tanks project was completed on time and budget. As a subcontractor to United Civil Construction, Paneltech played a critical role in delivering a successful result. The new pump station has dramatically reduced the number of sewage overflows following heavy rain events and the council is now considering building similar structures elsewhere within its network.