Case Studies

Whareroa Water Treatment Plant – Wet Well Water Intake Taranaki (2016)

The Brief
To provide a reliable source of water intake for a new water treatment plant providing up to 1200 m3/hr to a major dairy factory site.

The Issues
The system needed to be a cost effective, reliable and robust system to extract water, in line with the consent conditions and with minimal environmental impact.

The Solution
We began by driving a 14m deep vertical shaft using segmental concrete rings with stainless steel splice plates. We then bored a horizontal shaft to a stainless steel intake structure within the river bed.

Two suction pumps, each weighing two tonnes, were then installed and connected to booster pumps in the nearby lift station. NDA Site Services provided all mechanical services and commissioning support to completion.

We minimised the environmental impact by driving the shaft without mass excavations, then installing stainless steel suction riser pipes and connections to the booster pump station.

Clandeboye Dairy Factory – South Island (2018)

The Brief
To provide and install 15 silos with a  capacity of 250m3 and five with a capacity of 100m3 at a new cheese plant, giving a total of 4,250,000 litres of storage capacity.

The Issues
The silos needed to be provided within a short lead-time, and installed to new seismic standards.

The Solution
We took industry learnings from damaged silos and hold down systems from recent New Zealand earthquakes, along with new seismic codes, to improve our fabrication and installation techniques.

We also undertook continuous quality management and auditing throughout the fabrication and installation process, to give assurance to the client.

Lyttleton Port – South Island (2019)

The Brief
To restore the cultural and ecological health of Lyttelton Harbour, as part of the Council’s wider Waka-Ora plan, working with Te Hapu o Ngati Wheke, Te Runanga o Ngai Tahu, Lyttelton Port Company and harbour communities.

The Issues
Wastewater discharge into Lyttelton Harbour from Diamond Harbour, Governor’s Bay and Lyttelton.

The Solution
The wet well and buffer tank form part of a series of pump stations transporting all wastewater from the bay communities under the harbour to Lyttelton and then on to the main Christchurch wastewater treatment plant in Bromley.