Foodstuffs Auckland is New Zealand’s largest retail organisation employing over 30,000 employees. The company recently implemented an innovative water-harvesting project in Auckland, designed to save millions of litres of potable water.
The project, for CTD Nesdale – Foodstuffs’ chilled and frozen goods distribution site – now harvests rainwater for use in the site’s refrigeration system. Chris Wilmoth, Operations Manager with Foodstuffs Auckland, explains the site has two areas; a chiller which runs at approximately +2°C and a freezer which runs at about -25°C. “The rainwater is now used to cool ammonia which circulates throughout the building creating the cool temperatures,” he said.
As part of the project, rainwater is stored in an 840 cubic metre tank, supplied by leading storage tank company Tasman Tank Co. “As the site was expanded, there was an increased need for water which had to be met. The tank has saved us huge quantities of water, as now we are able to use rainwater collected from the roof instead of Auckland City’s water supply,” Wilmoth said.
The tank, a TS 600 bolted tank with a heavy duty Aeon PTR liner, measures 15m x 4.76m and has an effective capacity of 630 cubic metres. “We chose Tasman Tanks as they are specialists in large capacity tanks. They understood our needs and used their expertise to make sure these were met,” said Wilmoth.
He explained that this was Foodstuffs’ first water harvesting project. “CTD was chosen first, but we are always thinking about how we can improve/expand our services however we always aim to do so in a productive and sustainable way.
“The tank was part of an expansion project of the site which took approximately 12 months. The expansion had to take into account our growing industry but also the new needs that expansion would require especially water thus the tank was included in the design. Future plans will definitely include water harvesting so we will have minimal impact on the environment,” he added.
Wilmoth went on to say he would definitely recommend other companies consider investing in such a project. “There are so many benefits to be gained both financial and environmental,” he said. “Whilst we have financial goals we also have environmental goals. Water harvesting is just one aspect of how we can grow in a sustainable way as a company. We had the resources available to use water harvesting and thus took advantage of it. This has paid off hugely.”
Ian McGregor, Tasman Tanks’ New Zealand territory manager, said the move by Foodstuffs to use a bolted steel tank made a lot of sense. “The modular tanks are speedy and safe to erect, and offer a method of construction that can be readily and aesthetically blended with surrounding buildings in applications such as commercial and industrial mining, energy, resources, manufacturing, government and infrastructure, engineering, food and beverage processing, chemical and primary product processing, water and waste water and fire protection.”
McGregor explained that bolted steel tanks are steadily overtaking alternatives such as concrete because they won’t leak, they are less expensive to build in the first place, they are cheaper and easier to maintain and typically outlast alternative materials.
“Welded tanks would have been an option here but they are more expensive to build,” McGregor explained. “This particular liner type tank installed is an all steel bolted round tank using Zincalume sheet panels that when required can be powder coated to blend with existing buildings.”
McGregor said another major factor giving impetus to the adoption of bolted construction throughout New Zealand is suitability and speed of construction in remote and climatically challenging areas. “Bolted site construction allows for control of all quality processes in good or bad weather. It is not subject to uncontrolled factors from outside influences, which (in the case of concrete) can impact upon mixtures specifications and joint connections.”