Growing demand for clean water is predicted to result in shortages and highlights the potential contribution of unconventional sources, like salt water and wastewater, for agriculture (including irrigation and animal management), thermoelectric cooling, mining, oil and gas extraction, industrial and manufacturing processes, and drinking water.

While water managers in 40 U.S. states expect some portion of their community to experience shortfalls by 2024, a solution awaits in runoff drains, farmlands and the ocean. The key research and development (R&D) needed to lower the cost and energy of desalination of nontraditional water sources to provide a viable marginal water supply in the major sectors mentioned are identified in a roadmap developed by the National Alliance for Water Innovation (NAWI). The research guidelines are intended to advance the NAWI goal to achieve a circular water economy in which 90% of non-traditional water supplies can be cost-competitive with existing water sources.

The recommendations focus on developing technologies for targeted removal of trace solutes for regulatory compliance, enhanced water recovery and resource valorization. Sensor networks and adaptive process controls are needed for efficient, resilient and secure water treatment systems. Emphasis must also be placed on enhanced reliability and longevity of water treatment equipment and distribution systems through development of adaptable processes that are not adversely affected by feedwater variability and robust materials that are resistant to fouling and corrosion.

Dramatic reductions in the cost and energy intensity of concentrate management can be realized by maximizing brine valorization, developing novel processes for brine concentration and reducing the costs of small-scale brine management systems. Materials and manufacturing innovations are needed to substantially reduce the cost of small-scale desalination and fit-for-purpose reuse applications.

The research roadmap also covers electrifying water treatment processes and facilitating their integration with a clean energy grid, adoption of new types of small-scale desalination and advanced water treatment systems, and autonomous operations advancements to serve as an enabling feature for new forms of distributed desalination and water recycling systems.