The Great Salt Lake: getting more minerals with less water

Regional water scarcity and increasing demand for critical minerals are two of the most important environmental issues for planetary health. New technologies and improved brine management can help mitigate both issues simultaneously. 

What comes to mind when you think of brine? You might remember using it in a juicy roast or hearty soup to add warmth and flavor during the bitterly cold months. But brines extend beyond the kitchen – these water-based salt solutions are naturally found in oceans and salt lakes. Brines often contain minerals such as lithium and magnesium that are critical to the clean energy transition. With demand for critical minerals projected to more than triple this decade, shortfalls may limit or slow the transition to clean power generation (e.g., wind and solar power) and clean transportation (e.g., electric vehicles). 

Brines are also industrial byproducts (e.g., from desalination or oil and gas extraction), and these waste streams are often discharged into surface waters where their high salinity can disrupt marine life (see Figure 1). However, the high mineral concentration of these brine wastes makes it more economical to extract critical minerals from them, reducing recovery costs by over 50%. By optimizing mineral extraction from both brine waste and natural brines through technological innovation and improved management, we can address critical mineral demand while also mitigating the environmental damage from conventional brine disposal. These processes will also help alleviate freshwater shortages that now threaten nearly four billion people globally due to overuse, pollution, and climate change.

Figure 1: Conventional brine disposal

Figure 1. Conventional brine disposal limits water and mineral recovery while harming the environment. Below are the top five conventional disposal methods, with percentages indicating their share of total brine waste and the associated environmental impact in yellow.

Utah’s Great Salt Lake, the largest salt lake in the Western Hemisphere, provides an excellent case study on brine management. In just 37 years, the Great Salt Lake has lost over 70% of its water volume and shrunk by more than 2,500 square miles due to excessive water use by agriculture, municipalities, and mineral extractors, highlighting what’s at stake (see Figure 2). Critical mineral extraction using solar evaporation ponds – a traditional brine mining technique – has contributed to roughly 10% of the Great Salt Lake’s water loss. 

Shallow solar evaporation ponds are filled with brine pumped from the source. Water in these pools naturally evaporates slowly in the sun over months or even years, leaving behind concentrated salts for further processing. While this process provides critical minerals – such as lithium – that are found in high concentrations in the lake, it also depletes the reservoir, and has contributed to the Great Salt Lake receding to a record low water level. That decline threatens Northern Utah residents and the broader ecosystem with toxic dust storms, the collapse of a habitat for 12 million migratory birds, and disruptions to the regional water cycle. Do you like to ski or board Utah’s famous powder? That could also be affected by a shrinking Great Salt Lake, further damaging the local economy. While the state has made significant investment and changes to policy to increase water levels in the Great Salt Lake, only roughly 10% of the water necessary to restore the lake has been conserved.

Figure 2: The great shrinking lake

Figure 2. Great Salt Lake depletion over time due to unsustainable extraction. Slide bar to compare. Left, June 1985; Right, July 2022. Images via NASA.

New extraction technologies with greater selectivity and efficiency can economically capture critical minerals with greatly reduced environmental impacts: a win for people, planet, and profits. New technologies using membranes, adsorbents, and/​or organic solvents to extract minerals and recover water from brine are faster, more efficient, and more sustainable than solar evaporation. By deploying these technologies at scale – which has yet to be proven – these companies could process brines in a matter of hours to days (as opposed to months to years through evaporation), achieve higher recovery rates, require less land, recover water that would otherwise be lost to evaporation, produce fewer emissions, and return the processed brine back to its source. 

However, new technology alone won’t solve this problem – we also need smart regulation and strong public-private collaboration to ensure market adoption. Last year the Utah legislature passed a new law to (1) incentivize sustainable mineral extraction from the lake and (2) impose fees for unsustainable practices. Until this new law passed there were no restrictions on rights to deplete the Great Salt Lake and no incentive or authority to increase conservation. 

Now, mineral extractors using unsustainable practices will be required to pay a higher severance tax unless they enter voluntary agreements with Utah to mitigate water use. These agreements tie water consumption limits to lake health, offering tax breaks to mineral extractors that enter them (Compass Minerals recently became the first company to enter such an agreement). The law also requires mineral extractors to adopt commercially viable, innovative technologies to minimize water depletion within five to seven years. 

RA Capital’s Planetary Health team has partnered on this article with Grow the Flow, a nonpartisan organization focused on restoring the Great Salt Lake. Together, we hope to bring awareness to the issues caused by traditional evaporative mineral recovery methods and encourage greater investment in more sustainable technologies. In highlighting the case study of the Great Salt Lake and the state of Utah’s conservation efforts, we are deepening our understanding of brine management, which also aligns with our broader explorations into agriculture’s outsized impact on freshwater withdrawals and water pollution. The Planetary Health Team evaluates potential investment opportunities based not only on reducing emissions but also increasing resource availability and improving environmental quality. Recognizing the lake’s importance to Utah’s economy and community, Grow the Flow aims to balance the needs of mineral extractors, agriculture, and residents. Through community organizing, coalition building, research coordination, and policy drafting, it seeks to make Utah the first state in the US to reverse the chronic decline of a saline lake and restore this invaluable ecosystem in perpetuity.

Whether you are a business leader, policy maker, researcher or simply someone passionate about making a difference, we invite you to join the movement to preserve the Great Salt Lake and improve brine management more broadly. Reach out to RA Capital or Grow the Flow today to become part of this important effort! If you or your business is interested in getting involved with the growing effort to save the Great Salt Lake, you can reach out to Jake Dreyfous (jake@​growtheflowutah.​org; (801) 712‑0026). Individuals can learn more about Grow the Flow by signing up for its Newsletter, which provides bi-weekly updates and action opportunities, or donate HERE. 

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