A new study conducted by University of Massachusetts Amherst in partnership with the University of Alaska Anchorage has found that lithium mining in Chile has a limited impact on water resources compared to agriculture and copper mining.
Declines in groundwater availability, the research shows, are largely attributable to copper mining, agriculture and household consumption. Lithium mining does reduce groundwater availability, but to a lesser extent than other sectors. The study focused on whether water supply would restock levels to compensate mining activity and found that this may depend on how old the water is, given that the recharge times for most aquifers in the region are greater than 65 years.
The mining of lithium takes place in very arid areas, and there have been public concerns over the environmental impact of the mining of metal. There is a rapid growth in the global demand for lithium following the growth in demand for batteries, amongst others for electric vehicles. The Salar de Atacama in Chile holds some 42% of the world’s lithium reserves, contained in brine in underground aquifers.
Brendan Moran, the lead author of the paper, said: “To understand the environmental effect of lithium mining, we need to understand the hydrology in the region the lithium is found. That hydrology is much more complex than previous researchers have given it credit for.”
The researchers focused on Chile’s Salar de Atacama and showed that all inflows into the basin are composed of water that flowed into the basin more than 65 years ago. As a result,
means that studies over a longer period of time would be needed to properly evaluate the impact of lithium mining. Moran said: “Because these regions are so dry, and the groundwater so old, the overall hydrological system responds very slowly to changes in climate, hydrology and water usage.”
With drought episodes becoming more frequent due to climate change and lithium’s demand on the rise due to it being an essential part of electrical car batteries, researchers think this may have an impact on the rate of water resupply.
The study, published in the journal Earth’s Future concludes that the use of fresh water from the Chilean deposit is exceeding resupply rates, but it claims this is not due to lithium mining but, rather, other uses.
This research was funded by BMW Group and BASF, the same companies that own the lithium mining infrastructure in Salar de Atacama.