An upgrade required for the Ngunguru Wastewater Treatment Plant involved the supply and installation of a precast concrete ultraviolet light (UV) treatment chamber at its existing wastewater treatment facility. The Ngunguru wastewater treatment plant treats the sewage from the small coastal Whangarei township. The treatment plant was upgraded in 2009 to incorporate an aerated oxidation pond and wetlands and in 2011 the council decided to further upgrade its UV disinfection system to improve the quality of the final treated effluent.
The initial project proposal involved a refurbishment of the existing concrete UV treatment chamber at the Ngunguru wastewater treatment facility in order to improve the quality of final treated effluent leaving the plant.
Through discussions with the client, Paneltech proposed an alternative solution, which would involve the supply and installation of a precast concrete UV treatment chamber, rather than refurbishing the existing plant. The value of the subcontract works was $70,000.
Paneltech contributed to the upgrade of the Ngunguru Wastewater Treatment Plant, sub-contracting through lead contractor United Civil Construction. The initial proposal for a refurbishment of the existing concrete UV treatment chamber was superseded by a solution put forward by Paneltech to build a new chamber. The project would be undertaken at the same cost, but would give the chamber a longer life span and would be quicker to install, meaning the plant would be ‘offline’ for less time. Paneltech proceeded with the supply and installation of a new precast concrete UV treatment chamber, made challenging because the process demanded that the chambers be built to within 3mm tolerances.
The upgraded facility at Ngunguru has achieved the desired impact of improving the quality of the final treated effluent.
The project was completed on time and budget, with Paneltech’s recommendations leading to a new treatment chamber that was quicker to install, leading to less downtime for the plant during installation. The installed chamber will also have a longer life span than if the existing chamber had been refurbished.