Beverage industry saving water

Stormwater harvesting scheme

After achieving a 5-star rating in the Every Drop Counts Business Program, Coca-Cola Amatil has remained environmentally focused while building its High Bay Warehouse at Northmead, Sydney.

The company will use the High Bay Warehouse’s 6000 m² roof area to run a stormwater harvesting scheme. The water captured will be diverted into two underground storage tanks totalling 1.87 million litres and the project is estimated to save 9 ML of water per year.

The company has a ‘first flush’ water diverter option built into its rainwater collection system. This could be used to improve the quality of the water collected by diverting the more polluted water that initially runs off the roof and preventing it from entering the storage tanks.

The rainwater collected in one of the storage tanks will be treated and filtered to drinking water quality. The water captured in the other tank will be used to substitute water on site in processes such as flushing toilets and irrigating a council park.

With up to 200 m³ of rainwater stored in a 25 cm deepening of the eastern Onsite Detention tank, a submersible pump will provide water from this tank to the irrigation system. The floor of the tank will fall towards sumps to allow removal of accumulated sediment as necessary.

The irrigation water will be filtered before being pumped through an irrigation reticulation system to landscaped areas. This system will allow all irrigation water to be supplied from on-site harvesting.

The company hired an ecologically sustainable development consultant to look at areas where water efficiency could be achieved. The consultants assisted in the early days of the project with the conceptual planning and advised the company about rainwater harvesting, water re-use, water usage efficiency and equipment to install to increase efficiency.

The consultants found that: the use of potable water for irrigation will be eliminated by the storage of rainwater collected on site; the use of potable water for domestic use will be minimised by the use of water-efficient devices; all wastewater discharges will be treated to the standards required by Sydney Water before discharge from the site to sewerage reticulation mains.

CCA has plans to extend this project to other plants and to increase the roof area used at the Northmead plant, but will first wait for the results of the Northmead project.