The South West Arkansas lithium project is a lithium-brine project located in Arkansas, US.
The project is being developed by Smackover Lithium, a joint venture between Standard Lithium, which holds a 55% equity interest and operates the project, and Equinor, which holds the remaining 45%.
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A pre-feasibility (PFS) study for the project was released in August 2023.
In April 2025, the Arkansas Oil and Gas Commission (OGC) approved the phase one brine production unit spanning 20,854 acres and formally designated the Reynolds Unit, following a public hearing.
An updated feasibility study was released in September 2025. The latest study outlines an initial development phase with a 20-year operating life and an estimated capital requirement of approximately $1.45bn.
In October 2025, the OGC approved the integration application for the Reynolds Brine Unit, which consolidates unleased mineral interests into an authorised unit while protecting the correlative rights of mineral owners.
The first phase is designed for an annual output of 22,500t of battery-grade lithium carbonate, with start-up targeted for 2028.
Project location
The South West Arkansas lithium project is located approximately 24km west of Magnolia, Arkansas, within Lafayette and Columbia counties.
The project comprises 947 brine leases and eight brine deeds covering roughly 11,438 net mineral hectares.
Geology and mineralisation
The South West Arkansas lithium project is hosted in a confined aquifer system within the Smackover Formation, where lithium-bearing brine is held in the formation’s pore space.
The Smackover Formation is typically divided into upper, middle and lower intervals. Reported resources are associated with the Upper and Middle Smackover, while the Lower Smackover is not included in the current estimate and is considered a longer-term exploration target.
South West Arkansas lithium project reserves
The proven and probable reserves for the initial phase of the South West Arkansas lithium project were estimated at 709,000t of lithium carbonate equivalent (LCE), as of September 2025.
Mining methods
Lithium-rich brine is set to be extracted from a network of 12 brine production wells drilled into the Smackover Formation from four pads to depths of 2,600m-2,900m (8,500ft-9,400ft) vertical depth beneath mean sea level.
Spent brine will be reinjected via ten injection wells located on three of the four pads. A further pad is planned in the eighth year, adding two production wells and two injection wells.
Directional drilling is expected to support the layout and limit surface infrastructure across the five multi-well pad sites.
The production wells are designed as conventional brine wells fitted with electric submersible pumps rated between 220kW and 660kW. Well flow rates are expected to range from 1,000 cubic metres per day (m³/d) to 4,500m³/d, averaging around 2,300m³/d, with total brine production projected at around 1,325 cubic metres per hour on an annual average basis.
At the pads, three-phase separation will be used to split brine, sour gas and small volumes of hydrocarbon liquids and solids before brine is routed to a central processing facility (CPF) through buried fibreglass pipelines.
No dedicated mining fleet is planned beyond light vehicles for field operations.
Processing at South West Arkansas lithium project
Incoming brine at the CPF will be degassed, pH-adjusted, filtered and conditioned through staged pre-treatment ahead of direct lithium extraction.
The selected process uses Aquatech’s proprietary Lithium Selective Sorption (LSS) technology to capture lithium and produce a lithium chloride solution with low impurities.
This stream is further treated through chemical softening and ion exchange, then concentrated using reverse osmosis, followed by evaporation and crystallisation to increase lithium chloride strength.
The concentrate is converted to crude lithium carbonate through a conventional carbonation circuit, then upgraded through purification steps including bicarbonation, ion exchange and decarbonation, with carbon dioxide recovered for reuse.
The final lithium carbonate product is dried, micronised and packaged.
Site infrastructure
The project area is supported by an established, all-season secondary road network, with access provided by US routes and Arkansas state highways. US Highway 82 runs west to east, linking Lewisville, Stamps and Magnolia, while US Highway 371 passes to the south-east of the site. Arkansas State Highways 29, 53 and 313, along with improved county roads, also connect to the area.
Water supply is planned from submersible pumps wells drilled at the CPF, designed to deliver around 1,700 gallons per minute, with studies ongoing to confirm the number of wells needed to maintain sustainable yields.
Total power demand is expected to be 40MW and is due to be supplied via an electrical network supported by a natural gas-fuelled generation plant.
Offtake agreements
Smackover Lithium signed a binding take-or-pay offtake agreement in March 2026 with Trafigura for 8,000 tonnes per annum (tpa) of battery-grade lithium carbonate over a period of ten years, commencing with commercial production.
The venture is seeking further offtake arrangements to cover a large share of phase one nameplate capacity.
Financing
In September 2024, the project was invited to enter negotiations with the US Department of Energy (DoE) for potential support of up to $225m under a funding round administered by the Office of Manufacturing and Energy Supply Chains, aimed at strengthening domestic battery supply chains and increasing US production of critical minerals. The DoE confirmed the award in January 2025.
By December 2025, the venture had received interest from three export credit agencies including the Export-Import Bank of the United States and Export Finance Norway regarding senior secured project debt exceeding $1bn to help fund phase one construction.
Smackover Lithium is pursuing a senior secured, limited-recourse debt package of up to $1.1bn, structured around an export credit agency-supported component with direct lending and guarantees for a covered tranche, alongside an uncovered tranche from commercial banks.
Contractors involved
The definitive feasibility study for the project was prepared by Ausenco Engineering Canada with collective input from Haas & Cobb Petroleum Consultants, Hunt, Guillot & Associates and Trinity Consultants.
The PFS was prepared by HGA, Haas & Cobb and Alliance Technical Group.
