Otumahi Water Supply Bore

A new bore site was developed (with associated treatment plant and pump station) at the site located on Paul Road.

Works involved the installation of a 75kW submersible pump down existing 300dia bore casings. 169m of galvanised 6” threaded riser pipework connected the bore pumps to an above ground headworks configuration containing sluice valves, strainers, backflow prevention devices and flow meters. New PE pipework was installed between the bore headworks and the new WTP building. The WTP building consisted of a 4 room 10m x 10m blockwork structure. The WTP building housed the water treatment equipment, electrical and telemetry equipment, chlorination equipment and booster pumps and associated manifolds.

Also included within the project was the construction of a new 150m³ steel reservoir.

Essentially raw water is extracted from the onsite bore, then piped to the WTP building where caustic and chlorination treatment is provided to the raw water. The treated water is then piped to the on-site reservoir. Treated water is then piped back through the WTP building and directed to the automated booster pump system which then pumps the treated water to the Council supply. Onsite PE pipework ranged in size between 300dia to 525dia.

Phoenix also undertook comprehensive commissioning of the WTP, including dry, wet and final commissioning.