Anglo American: Reducing freshwater use for sustainable mining

Anglo American’s Metallurgical Coal business has commissioned the first of two planned reverse osmosis (RO) water treatment plants at its Aquila project in the Bowen Basin, with the aim of reducing the use of freshwater in its mining operations.

The Aquila project is an underground metallurgical coal mine currently under construction which will extend the life of Anglo American’s Grasstree underground mine near Middlemount in Central Queensland. Aquila is on track for first coal in early 2022 and will utilise the associated Coal Handling and Preparation Plant (CHPP) on site – part of Anglo American’s Capcoal complex. The freshwater allocation is approximately 6.2 megalitres (ML) a day, which includes supplying water to the town of Middlemount*.

In the RO process, water passes semi-permeable thin membranes with pores small enough to allow the water to flow through the membrane while rejecting larger particles or contaminants. At Aquila, the new RO plant filters mine affected water (MAW) – water already used in the mining process. This first plant is producing 2 ML of treated water per day for the construction of Aquila and the planned second RO treatment plant will produce 2.4 ML of treated water, more than doubling capacity. The recycled water will work to reduce the reliance on freshwater at Aquila, both during construction and once operational, while helping to drought-proof operational water supplies.

In metallurgical coal mining, water is used for processing the coal product, dust suppression, equipment cooling, longwall roof supports and coal cutting operations.

Currently, there is a large inventory of MAW available for treatment, which can be treated for the mining process in favour of freshwater or water found in the
environment. A remotely operated system of pumps and pipelines transfers the water to where it is required including the RO treatment plant.

Aquila’s integrated water management system is helping to transform how the mine can best use existing on-site mine water inventories, with a focus on
improving sustainability by shrinking its dependence on externally sourced freshwater.

To this end, RO plants are helping to maintain a healthy environment which is part of Anglo American’s Sustainable Mining Plan for its Metallurgical Coal business. The plan sets out ambitious targets, designed to challenge the company to lead and innovate in reducing its environmental footprint.
Among other targets, the water target aims for a future where Anglo American can operate while using less water: reduce the abstraction of freshwater by 50 per
cent by 2030.

For more information on Anglo American’s Sustainable Mining Plan visit

*Only freshwater is sent to Middlemount not the recycled water