Technoeconomic Framework for Evaluating Desalination and Brine Management Pathways across the United States

The growth of desalination capacity to address global water stress has intensified the need for effective and economically viable brine management strategies. This work develops a geospatial technoeconomic analysis framework for freshwater production using desalination (via reverse osmosis) with brine management across the United States. Levelized cost of water (LCOW) is used to determine the most viable brine management approach as a function of geographic location, feed salinity, transport distance, and revenue from salt recovery. The results show that ocean discharge (OD) is the most favorable brine management strategy across most of the country owing to its relatively low disposal cost, particularly in coastal regions where seawater (SW) desalination has LCOW values between 1–1.5 $/m³. However, transport costs increase substantially with distance from the coast, making desalination of alternate feed sources such as brackish groundwater (BGW) and produced water (PW) more practical. For low salinity BGW feed, zero liquid discharge (ZLD) is generally not economically competitive because limited salt recovery cannot offset the high capital and operating costs associated with brine concentration (mechanical vapor compression or MVC) and crystallization (evaporation pond or EP) systems. In contrast, PW feed with higher salinity favors ZLD due to increased salt recovery potential. A sensitivity analysis further reveals that feed/brine transport cost has the largest impact on LCOW, while ZLD equipment cost and salt revenue become increasingly important for higher-salinity feed. These results are used to develop a regime map that identifies the economically preferred brine management pathway as a function of feed salinity and distance from the coast, thereby providing a generalized decision-making tool for implementation across the United States.