The Contract Works involved the construction of a new earth wastewater treatment aeration basin at the Rangiora Wastewater Treatment Plant (WWTP). The site was an active wastewater treatment plant and the contract works were carried out at the same time as other significant construction works to construct a new inlet pump station and screening channel.

Existing pipelines had to be protected and remain live throughout the period of the contract works. Temporary bypassing pumping and pipework was required to maintain a live network/plant.

The project also involved the construction of several reinforced concrete structures, the largest of which was the distribution chamber which was over 5m deep and completed within sheetpiled temporary works chamber.