It’s amazing to think that 97% of the world’s water is salt water, 2% is glacial ice, and just 1% is water that is actually suitable for drinking, agricultural and mining purposes. With Australia being one of the driest continents in the world, mining operators need to continually advance water management strategies and technologies to secure supply and minimise their environmental footprint.
All stages of mining production rely on water, either for exploratory drilling, production or site rehabilitation, and downstream processing. Without water, it’s impossible to operate a mine, and the Australian mining industry is one of the most important contributors to the Australian economy – so managing this well is critical.
According to the Australian Bureau of Statistics, in 2014 – 15, approximately 76,140 gigalitres of water was extracted to support the Australian economy. Of this amount, 768GL was used for mining operations, a large increase from the 652GL consumed for mining the year before, and almost doubling since 2009-10. According to a study by Monash University, it takes approximately 1690L of water to process one tonne of gold ore, and approximately 773,000L to produce one kilogram of gold. So, it’s a thirsty business and wanting more.
With water becoming increasingly finite due to a growing population, economic issues and the ongoing effects of climate change, there’s even greater competition for existing water supplies. The supply of purchased water is becoming increasingly expensive due to the associated cost of the infrastructure needed to move and store it. Obtaining a permanent water licence from the government is expensive and there is only such much water to extract. it’s hard to envisage the price of water getting cheaper in the future.
The issue of water management is amplified by the fact that mine sites are typically located in remote areas of the country, where water can be both scarce and, at certain times, overabundant after periods of extremely high rainfall. Anyone who wears a high vis vest, a helmet and has dirty boots knows this all too well!
With high rainfall, many mining sites become flooded, and it’s becoming more and more difficult to treat and discharge this excess waste water. Increased environmental regulation and community concern means that the days of simply discharging after a rainfall event are long gone.
Mine site’s isolated locations typically mean that established water and sewage infrastructures are not readily available, and wastewater rich in metals and harmful particles require intensive treatment – which is not easy to do. Mining operators face ongoing difficult decisions on how to extract and dispose of this wastewater safely and cost-effectively, ensuring no pollutants such as lead and uranium flow out into the environment. Miners must be continuously innovative, aiming for a point of sustainability across their operations amidst concerns from local landowners and environmentalists.
With a scarcer resource, greater competition and greater scrutiny, better management is not only a good idea but essential. Furthermore, the onsite re-use or treatment of water is both a cost-saving and environmental risk management measure.
Harbak is currently investigating several operational models for better water management on site to reduce both capital and operational expenditure, as well as ensuring environmental compliance. We will be happy to share these in the new year once our results are confirmed.
Keiran Travers is the Founder and Director of Harbak. The company provides Business Management, Business Match-Making (Business Development) and Advisory Services. Harbak provides strategy, procurement and infrastructure planning advice as well as advice regarding development approvals and environmental compliance to the waste management and mining sectors. Contact https://harbak.com.au/contact