Oral Presentation NCGRT/IAH Australasian Groundwater Conference 2019

Integrating surplus and potable water management in the Pilbara (543)

Mal McGivern 1
  1. BHP Billiton, Perth, WA, Australia

Although water has always been a huge part of BHP’s governance, risk and operational practices, increasing pressures on water resources such as population, climate change, and how different areas of water management integrated within the business, was not clearly defined.

The long-term directional plan for future ore bodies to be mined within BHP Western Australian Iron Ore (WAIO) has indicated that there will be an increase in mine dewatering flows associated with a growing percentage of deposits situated below the water table. In Western Australia, the Department of Water and Environmental Regulation (DWER) has established a “hierarchy of controls” for Surplus Water Management within the mining Industry.

  1. Mitigate - Impacts
  2. Use Onsite – Processing, dust suppression
  3. Transfer – To a 3rd party – beneficial use
  4. Reinject – or infiltrate back into aquifer
  5. Discharge

In line with this, and BHP’s Water Stewardship Statement, WAIO has determined that infiltration, and Managed Aquifer Recharge Bores (MAR) are the preferred method of discharge of excess water at our operations, to minimise environmental impacts.

At WAIO we are required to manage operational water issues, such as dewatering/discharge and process water supply, as well as provide safe and clean drinking water to our mines, towns and mining residential camps that support these operations. As mining operations expand and potential excess water discharge locations expand, there’s the potential for surplus discharge schemes to interact with drinking water supply borefields. A Surplus Water Operationalisation program was undertaken to help address this issue.

The Surplus Water Operationalisation program was developed to ensure that as assets are being planned and developed, accountabilities, operational controls within a detailed management system, to ensure an operational model with appropriate controls are implemented to manage environment, regulatory, operational, and maintenance risks, and interconnectivity with potable water sources.