Department of Chemical and Environmental Engineering and ‡School of Forestry and Environmental Studies, Yale University , New Haven, Connecticut 06520, United States.
Environ Sci Technol. 2014 May 20;48(10):5883-91. doi: 10.1021/es405648x. Epub 2014 Apr 29.
Increased water demand and scarce freshwater resources have forced communities to seek nontraditional water sources. These challenges are exacerbated in coastal communities, where population growth rates and densities in the United States are the highest. To understand the current management dilemma between constrained surface and groundwater sources and potential new water sources, Tampa Bay, Florida (TB), and San Diego, California (SD), were studied through 2030 accounting for changes in population, water demand, and electricity grid mix. These locations were chosen on the basis of their similar populations, land areas, economies, and water consumption characters as well as their coastal locations and rising contradictions between water demand and supply. Three scenarios were evaluated for each study area: (1) maximization of traditional supplies; (2) maximization of seawater desalination; and (3) maximization of nonpotable water reclamation. Three types of impacts were assessed: embodied energy, greenhouse gas (GHG) emission, and energy cost. SD was found to have higher embodied energy and energy cost but lower GHG emission than TB in most of its water infrastructure systems because of the differences between the electricity grid mixes and water resources of the two regions. Maximizing water reclamation was found to be better than increasing either traditional supplies or seawater desalination in both regions in terms of the three impact categories. The results further imply the importance of assessing the energy-water nexus when pursuing demand-side control targets or goals as well to ensure that the potentially most economical options are considered.
水资源需求的增加和稀缺的淡水资源迫使社区寻求非传统水源。这些挑战在沿海社区更为严重，美国这些地区的人口增长率和人口密度最高。为了了解当前地表水和地下水资源与潜在新水源之间的管理困境，研究了佛罗里达州坦帕湾（TB）和加利福尼亚州圣地亚哥（SD），预测到 2030 年，这两个地区的人口、水需求和电网结构将发生变化。选择这两个地区是基于它们相似的人口、土地面积、经济和水消耗特征，以及它们的沿海位置和日益增长的供需矛盾。对每个研究区域评估了三种情景：（1）最大限度地利用传统供应源；（2）最大限度地利用海水淡化；（3）最大限度地利用非饮用水回收。评估了三种类型的影响：蕴含能源、温室气体（GHG）排放和能源成本。由于两个地区的电网结构和水资源不同，SD 在其大部分水基础设施系统中具有比 TB 更高的蕴含能源和能源成本，但 GHG 排放较低。在这两个地区，从三个影响类别来看，最大限度地回收水比增加传统供应源或海水淡化都要好。研究结果进一步表明，在追求需求侧控制目标或目标时，评估能源-水关系至关重要，以确保考虑到潜在的最经济选择。
