58 MLD Wastewater Pump Station Upgrade.


MTL were engaged by McConnell Dowell for the mechanical (tender) design for the upgrade of the second dry well to accommodate higher capacity pumps with a wider flow range (24 MLD – 58 MLD).

The Hobsonville pump station building was constructed approximately 10 years ago, but only one dry well fitted out. The design flow requirement increased significantly since the building was originally designed. Fitting significantly larger pumps than originally intended in the space introduced a number of design challenges. Our ultimate plant layout did not compromise hydraulic design or operational and maintenance access. Thickening of the dry well floor was required to accommodate the larger pump drive vibration and deflection limits.

Pump suppliers were consulted during the design process to ensure the pump performance was not compromised particularly in the wet well which required to be reformed to optimise flow.


The pump station design, particularly with regard to the operational and maintenance access, was well received when presented to the tender panel.


Watercare, McConnell Dowell, Arup, Neo.