The U.S. may not have enough water to support its lithium ambitions, a new Northwestern University study has found.
An essential ingredient for electric vehicle (EV) batteries and other clean energy technologies, lithium is largely mined in Australia and Chile and then processed and refined in China. In recent years, however, the U.S. has pushed to develop its own lithium industry to reduce reliance on foreign supply chains.
In the new study, researchers found that most proposed U.S. lithium mines - many located in already parched areas - could face significant water shortages. These shortages could worsen as climate change reshapes water availability and as competition for resources intensifies among farms, households, industry and power generators.
The study was published today (May 28) in the Communications Earth & Environment, a Nature Portfolio journal
"Even if all of the proposed mines become operational, the U.S. does not have enough lithium to meet national demand, regardless of all of the variables that we considered in our analysis," said Northwestern's Jennifer Dunn, who led the study. "We will likely still have to rely on foreign partners to supplement our lithium supply."
An expert on the environmental impacts of emerging technologies, Dunn is a professor of chemical and biological engineering at Northwestern's McCormick School of Engineering, director of the Center for Engineering Sustainability and Resilience and a member of the Paula M. Trienens Institute for Sustainability and Energy. Jenna Trost, a Northwestern Ph.D. candidate in Dunn's lab, is the paper's first author.
Lithium's hidden water cost
No matter how it's mined, lithium extraction can be incredibly water intensive. In some methods, machines pump lithium-rich brines from below the ground. The water evaporates, leaving the concentrated lithium behind. In other methods, workers crush rocks and then use water to process ore, wash materials and cool equipment.
"Water use in processing at hard-rock lithium mines can become contaminated with toxins like arsenic," Dunn said. "If we wanted to clean it up to the point where it could be put back into a river or lake, it would cost a lot of money and energy and emit greenhouse gases. So, we count that water as consumed because we can't get it back without a lot of processing."
Dunn and her team wanted to assess whether U.S. subbasins, or small water drainage regions, can support lithium mining. To do this, they combined five global climate models with four socioeconomic scenarios, a hydrology model and the projected water needed for mining. Each model simulates how Earth's climate responds to greenhouse gases. The researchers intentionally selected models representing different climate futures, including wetter, drier, hotter and more moderate scenarios.
The team then used the models to project water supply and demand between 2040 and 2060 for one active lithium mine in southwestern Nevada and 22 proposed U.S. lithium projects. Under every scenario, most western subbasins struggled to meet existing water demands, let alone support additional lithium mining.
Where shortages hit hardest
The most severe shortages appeared in southern California's Salton Sea region and across parts of Nevada, where multiple proposed mines would compete for limited water resources. Although agriculture and households will likely use more water than lithium mining, mining still would add significant pressure in already stressed regions.
"The lithium mining industry is trying to enter a region that is already water-strapped," Dunn said. "For this industry to come alive, it will require a lot more engineering to improve water efficiency and better water management."
The findings highlight the need for more water-efficient extraction technologies, more strategic location choices for new mines and stronger lithium recycling infrastructure, she said. Next, Dunn plans to assess how the changing climate might affect the U.S. demand for other critical minerals.
"Currently, lithium is an essential ingredient in energy storage technologies, so it's hard to replace," Dunn said. "It intersects with so many different decarbonization technologies. If we want to achieve energy transition goals and energy security goals, then we need lithium. But we're finding an underlying paradox. We need these minerals to help combat climate change, but climate change might make it harder to obtain these minerals. The U.S. will have to make some tough choices on the horizon."
The study, "Future U.S. lithium production with water and socioeconomic-climate considerations," was supported by a National Science Foundation (NSF) Graduate Research Fellowship and an NSF Office of International Science and Engineering (award number OISE-2330041).
