Technology is one of the five pillars of BHP’s Water Stewardship Strategy. We aim to leverage technology solutions that drive a step-change reduction in water-related risks, realise opportunities and deliver multiple benefits. By considering where new or emerging technologies have the greatest potential to make a step-change in the water challenges we face, we have chosen to initially focus on technologies that will:

• reduce the use of freshwater resources through more efficient re-use of water
• reduce the potential impacts to water resources from closed and operated assets

In FY2020, we completed a global review to develop a targeted technology test project list. In this review we engaged with providers of well-established water technologies and with water intelligence organisations to understand current, emerging and new water treatment technologies. We assessed the application of technology to specific BHP site water challenges through a panel of technical experts. The panel considered challenges including the re-use of process water streams at Olympic Dam and Nickel West to reduce the use of water resources; the treatment of pit void water in our Queensland Coal operated assets to reduce the use of water resources and improve water discharge quality; and the treatment of future pit lake waters and waste dump seepage at WAIO to prevent potential environmental impacts.

A program is underway at Olympic Dam to assess two emerging technologies for the treatment of a waste water stream (tailings storage facility decant liquor) so that it can be re-used rather than stored in lined evaporation ponds. If successful, the treatment will reduce or mitigate the potential increase of water extracted from the Great Artesian Basin. It may also reduce the future need for evaporation pond facilities and assist in the recovery of valuable minerals.