Instead of producing only one concentrate stream like most desalination processes, a key advantage of electrodialysis metathesis (EDM) is that it produces two concentrate streams, and each stream can be highly concentrated by separating divalent cations and anions. Our team's previous piloting of conventional EDM for treating reverse osmosis (RO) concentrate at the Brackish Groundwater National Desalination Research Facility (BGNDRF) in Alamogordo, NM achieved over 98% system recovery, but recent batch testing with Fujifilm's novel salt-free EDM process revealed that it uses approximately half of the energy of conventional EDM and does not require continuous consumption of sodium chloride (promising significant cost reductions). To our knowledge, salt-free EDM has not been piloted in continuous flow with various water chemistries to understand the limits of its application. The objectives of this proposed research are: (a) to demonstrate high recovery concentrate management in UTEP's existing solar-powered desalination pilot at BGNDRF (Fig. 1) with continuous-flow piloting of Fujifilm's salt-free EDM (including solid calcium sulfate recovery) and contribute data through the Water DAMS Repository, (b) to understand the limits of hydraulic recovery of salt-free EDM, and (c) to develop a salt-free EDM model within WaterTAP.