Waterleaf outlines lithium-extraction pilot at Great Salt Lake, says process returns most brine

Waterleaf, the project company affiliated with Lilac (technology provider), presented May 14 to the Great Salt Lake Advisory Council on a direct lithium extraction (DLE) pilot operating on the North Arm and described objectives and early results intended to inform commercial permitting.

Steve Mori, Waterleaf project director, said the company’s proposed commercial plant would produce about 5,000 tons of lithium per year and that — if built at the proposed scale — the plant "would double US production" of lithium produced domestically. Mori said the commercial target start date is 2027, with construction beginning in 2026 if permitting and funding close as planned.

Mark Mulligan, Waterleaf’s vice president of engineering, described the company’s ion-exchange bead DLE process: pump brine to a filtration step, pass it through a lithium-selective ion-exchange vessel to load beads, strip lithium from beads with dilute sulfuric acid to create a lithium sulfate eluate, concentrate and crystallize to lithium carbonate at an offsite facility, then return depleted brine to the lake after monitoring. Mulligan said the pilot is designed to be nonconsumptive and that at commercial scale the facility will recycle process water.

"We are proving nonconsumption there," Mulligan said while showing pilot graphs in which influent and return brine measurements were similar across many monitored constituents.

Waterleaf reported pilot averages of just under 70 parts per million (ppm) lithium in incoming brine and noted the North Arm feed has a high magnesium-to-lithium ratio. The company said permit-listed constituents are sampled weekly by both the Division of Water Quality and independent third-party laboratories (ChemTek) and that some early iron and aluminum spikes were driven by temporary metal tanks used during the pilot. Waterleaf said it engaged Dr. Bonnie Baxter to study biota impacts; preliminary sampling from two events showed no clear negative effects on measured biota, and full results will be included with permit applications.

During Q&A, council members and attendees asked for clarity on volumetric water balance, requested an estimate of annual water handling, and raised infrastructure and community‑impact questions. Waterleaf said a 5,000-ton commercial plant would require roughly 25,000–30,000 acre-feet per year of "nonconsumptive" throughput (the company emphasized that most water would be returned to the lake), that facility life‑design is about 20 years, and that daily truck traffic during operations is expected to be about 10–12 truck trips. On roads and mitigation, Waterleaf said the company expects to contribute as a taxpayer and use dust suppressants on private and adjacent roads, but that decisions about county-maintained roads and mitigation ultimately fall to Box Elder County.

The company also noted pilot design differences from commercial design (pilot uses some temporary metal holding tanks that affected early metal readings) and said long-form permit monitoring information will be publicly available once the commercial permit process advances.

Next steps: Waterleaf will complete the remaining pilot sampling and the biota study over the next several weeks, incorporate results into permit materials and continue coordination with state regulators as it advances commercial permitting.