Review of the Desalination and Water Purification Technology Roadmap (2004)

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Chapter 2 Overall Assessment of the Roadmap This chapter provides a broad review of the Desalination and Water Purification Technology Roadmap (Roadmap; USBR and SNL, 2003) and summarizes the findings presented in the committee’s letter report (NRC, 2003; see Appendix A), which addresses whether the Roadmap presents an appropriate and effective course to help address future fresh water needs in the United States. In this review, it is important to distinguish between the Roadmap document and the underlying process to develop, refine, and implement the Roadmap, which continues to evolve. Although the committee was specifically tasked to review the Roadmap document, several observations and suggestions are provided about the roadmapping process, since continued desalination research planning should benefit from lessons learned. This chapter also describes general recommendations to improve the effectiveness of the Roadmap. The chapter highlights concerns in the following areas: the vision statement, targets for critical research objectives, desalination technology needs, and implementation. A more detailed review of the desalination and water purification technologies presented in the Roadmap and implementation needs are provided in Chapters 3 and 4, respectively. Desalination technologies have the potential to serve as significant components of future water supply management, and a national research plan for desalination and water purification technology is important to help meet the nation’s future water needs (NRC, 2001b; NRC, 2003). As noted in Chapter 1, supply-enhancing technologies represent just one component in a multi-faceted strategy necessary to address future water needs. Nevertheless, a careful research and development strategy is necessary to facilitate technological advancements and nurture novel ideas that can enhance water supplies and reduce the costs of current technologies. The committee commends the Bureau of Reclamation and Sandia National Laboratories for leading this important research planning initiative. An initial assessment of the Roadmap was presented in the committee’s interim letter report (NRC, 2003). Because the Roadmap represents an evolving document that engages desalination experts in a process to guide desalination research investments, NRC (2003) noted “…this Roadmap and its underlying process appear to present an appropriate framework for advancing research in several areas of desalination and water purification technology to help address future water needs in all regions of the United States.” Several suggestions, however, were presented to strengthen the process and focus future efforts. NRC (2003) recommended that the Roadmap emphasize research to 19 

20 Review of the Desalination and Water Purification Technology Roadmap support advances in technology. Much of the Roadmap is dedicated to explaining the national need for safe, adequate, sustainable, and affordable water supplies, which could be enhanced by desalination technologies. However, little attention is devoted to the actual technologies and the associated research needed to meet the identified water supply objectives. Overall, a sharper focus on desalination research and technology and related treatment would improve the Roadmap, which loses clarity in its breadth. While water reuse and recycling utilize some of the same technologies as desalination, the field of reuse has research needs that are generally distinct from desalination technologies, especially when considering the issue of potable reuse. For lower-order reuse applications, such as landscape irrigation, desalination technologies may not be necessary. The Roadmap would be strengthened if research to support water reuse was considered separately in an initiative parallel to the development of a desalination research agenda, with each serving as a component to meet the nation’s freshwater needs. Concerns were raised in NRC (2003) about the use of the term “water purification” in the Roadmap title, which includes a wide array of treatment technologies and processes that are more often related to conventional water treatment plants than to desalination or desalination pre- and post-treatment. The committee was also tasked to evaluate whether the Roadmap presents an effective course for meeting the nation’s freshwater needs. Ultimately, the effectiveness of the Roadmap and its underlying process will depend upon its future implementation, and plans for implementing the Roadmap have not yet been resolved. VISION The Roadmap presents a vision statement that is intended to provide motivation to the entire effort (USBR and SNL, 2003): By 2020, the desalination and water purification technologies will contribute significantly to ensuring a safe, sustainable, affordable, and adequate water supply for the United States. • Provide safe water. A safe water supply is one that meets all drinking water standards, meets all standards for use by agricultural and industrial interests, and that strives to move toward greater water security during drought, natural disasters, transport, and terrorist attacks. • Ensure the sustainability of the nation’s water supply. A sustainable water supply is one that meets today’s needs without jeopardizing the ability to meet the needs of future generations. • Keep water affordable. An affordable water supply is one that provides water to the nation’s future citizenry at rates comparable to that of today. • Ensure adequate supplies. An adequate water supply is one that guarantees local and regional availability of water and that maintains reserves of water sufficient to endure episodic shortages such as drought. 

Overall Assessment of the Roadmap 21 The first sentence of the vision statement accurately reflects the contents and discussion contained in the body of the report, stating that desalination and water purification technologies will provide an important contribution to the development of water supplies that are safe, sustainable, affordable, and in adequate supply. However, inconsistent with the overall tone and direction of the remainder of the report, the expansion of the vision statement strays into water policy. For example, the text associated with “keep water affordable” suggests that research should strive to keep future water prices “at rates comparable to that of today.” While there are opportunities for research to determine the true cost of water in various regions across the United States, asserting what cost is appropriate steps beyond the stated mission of the Roadmap. The text associated with “provide safe water” attempts to define safe water as that which meets drinking water standards; the text does not consider the quality of the original water sources, which could include impaired waters such as municipal wastewater, or potential adverse health effects associated with emerging contaminants, which may not be included in existing drinking water standards. Although the current vision statement provides a means to structure the Roadmap, the vision should remain focused on the research and technology efforts that could contribute to future water needs. CRITICAL OBJECTIVES A series of critical objectives for desalination and related water purification technologies are presented in the Roadmap. These critical objectives represent quantifications of the United States’ needs in areas associated with the vision statement (see also Table 1-2). The objectives are broken down into near-term (by 2008) and mid/long-term (by 2010/2020) time frames and set metrics (or targets) for technological advancements in order to meet the nation’s anticipated water needs related to providing safe water, keeping water affordable, and ensuring adequate supplies and sustainability. Additional “stretch targets” were also provided. It can be useful to connect critical objectives to such, admittedly arbitrary, time frames, but the baseline values for these critical objectives should be provided (e.g., 2003 values for desalination cost and energy efficiency for various technologies) as a point of reference to gauge future progress. It should also be noted that research initiated today is not likely to be translated into technological improvements by 2008. The Roadmap would be substantially strengthened if the critical objectives had a logic and origin that could be readily understood. As noted in NRC (2003), “some of the targets identified do not appear well founded in science and may be unachievable.” The rationale for the critical objectives in the Roadmap should be clarified and referenced to historical improvements and current and theoretical limitations for the technologies. For example, the Roadmap presents an explanation of the cost structure for reverse-osmosis desalination of seawater (see Figure 3-2) that highlights the potential for reducing the costs through various technological improvements. Similar examples should be developed and referenced to justify the critical objectives identified, thereby increasing the plausibility of the Roadmap and fostering a more strategic approach to accomplish the goals of the Roadmap. Additional comments on the critical objectives for specific technology areas are provided in Chapter 3. 

22 Review of the Desalination and Water Purification Technology Roadmap TECHNOLOGIES In the Roadmap, research and technological improvements are presented as the mechanism for reaching the critical objectives. The five technological areas highlighted—membrane, alternative, thermal, concentrate management, reuse/ recycling—represent appropriate priorities for research and development in the field of desalination and membrane-based water purification. Nevertheless, these technological areas and their associated research issues receive limited discussion. Analyses of recent technological advancements, current limitations of desalination technologies, and opportunities for reaching the objectives identified are essential to strategic research planning, yet these are not developed in the Roadmap. A convincing justification of future research needs can only be developed based on a solid understanding of the current state of desalination technology relative to the technology objectives. As noted in NRC (2003), “the report would be improved by more thorough descriptions of the technologies and associated research opportunities, along with a list of technical references supporting the technologies identified in the report.” Increased involvement of representatives from the desalination industry (including thermal desalination technologies), the U.S. Environmental Protection Agency, and the energy/power industry in the desalination research planning process would be necessary to strengthen the technical discussions. The recommendations presented in the Roadmap for each of these technological areas are evaluated in detail in Chapter 3. Several important cross-cutting research areas are not adequately addressed within the five technology areas in the Roadmap, including energy use and air emissions from energy intensive desalination technologies. Energy efficiency and emissions (e.g., carbon dioxide and nitrogen oxides) could influence the potential and sustained contribution of desalination technologies to meet future water supply needs and merit additional attention in desalination research planning. Therefore, a sixth technology area entitled “cross- cutting desalination technology-related research” is proposed and described in further detail in Chapter 3. IMPLEMENTATION As stated previously, the effectiveness of the Roadmap and its underlying process will ultimately depend upon its future implementation. Although implementation issues have been discussed within the Bureau of Reclamation and by the Roadmap’s Executive Committee, an implementation strategy has not been determined and a detailed implementation plan is absent in the Roadmap. Thus, the interim report (NRC, 2003) stated that the Roadmap would be improved if it included a general implementation plan for this research initiative. Such an implementation strategy for the Roadmap should include a comprehensive peer-review process for selecting and funding research proposals, involving the widest range of scientists and engineers available. Mechanisms for setting research priorities, information sharing, and technology transfer should be developed. These implementation issues are discussed in more detail in Chapter 4. 

Overall Assessment of the Roadmap 23 CONCLUSIONS AND RECOMMENDATIONS Conclusion: The Roadmap does not explain how the critical objectives were derived. Recommendation: The Roadmap should be developed to include clear, understandable logic and scientific basis for each of the critical objectives. Conclusion: The five technical areas highlighted—membrane, alternative, thermal, concentrate management, reuse/recycling—represent appropriate priorities for research and development in the field of desalination and membrane-based water purification, but these technological areas and associated research issues received only limited attention in the Roadmap. Recommendation: The Roadmap should be developed to include analyses of recent technological advancements, descriptions of current limitations of desalination technologies, theoretical limits in ideal processes, and quantifications of baseline desalination values from which future advancements can be measured, which could provide the basis for developing a strategic research agenda for desalination. Conclusion: The Roadmap and its underlying process appear to represent an appropriate framework for advancing research in several areas of desalination, but the Roadmap document lacks an appropriate focus on desalination research and technology needs to meet the identified water supply objectives. Recommendation: A subsequent research agenda should be developed that logically builds from the current state of desalination technology toward the critical objectives.