<p> This dissertation adds to the body of knowledge of the <i>water-energy nexus</i> in four measurable ways. First, a water withdrawal footprint of energy supply (WWFES) to cities was developed, and placed it in the context of other water footprints defined in the literature. The WWFES provides a novel way to quantify direct and indirect water requirements to satisfy urban energy demand. The magnitude of the WWFES for Denver, Colorado was found to be 381 liters/person/day and 66% as large as all direct water uses in the city combined (mean estimate). This finding is relevant to urban sustainability planning as it shows significant water conservation may be achieved through energy efficiency and energy conservation. </p><p> Next, we demonstrate the robustness of the WWFES method for a rapidly developing city (Delhi) with unique energy requirements, energy infrastructure and data availability compared to the initial test case (Denver). Data collected for the Indian power sector enabled exploration of spatial- and temporal-variability of electricity supply to cities and the associated dynamic WWFES. Integrating over both space and time for one year, we estimate the water requirements of electricity production alone to be 36% as large as municipal water supply for Delhi, compared to 16% for Denver. In both cases, this highlights that electricity supply, like municipal supply, can be at risk during drought or other hydrological extremes, corroborated by interviews with industry experts. </p><p> The third and fourth contributions of this dissertation are to place water-related constraints to power generation in the context of other system risks using both social science methods and data-driven statistical analysis. For the former, a survey was administered to electricity infrastructure operators serving Delhi with three objectives: (1) identify and rank system risks to power supply reliability based on industry perceptions of risk; (2) identify and rank current and future service provision priorities; and (3) collect social network data regarding interaction between infrastructure operators. For the latter, an empirical study of electricity supply reliability in Northern India was conducted in a hierarchical modeling framework to assess the contribution of structural, environmental and supply-chain constraints to grid reliability. Model results indicate the WWFES is a statistically significant predictor of power supply reliability in Northern India when we control for structural, climate and supply-chain covariates. These results highlight the importance of the WWFES when evaluating risks to, and reliability of, trans-boundary energy systems.</p>

<p> One of the major challenges faced by civil engineering industry is to execute projects in harmony with nature. This is achieved to some extent by judicious use of natural resources in construction practices. In recent years, the demand for construction materials has grown tremendously, so has the amount of construction and demolition waste, putting huge pressure on the environment. This has encouraged the use of recycled aggregate in concrete, which not only allows for a more efficient life cycle of natural resources but also contributes to environmental protection leading to sustainable development. In this study recycled concrete aggregate (RCA) are used in the production of self-compacting concrete (SCC) in varying percentage replacements of natural coarse aggregate (NCA) The use of sustainable technologies such as supplementary cementitious materials (SCMs), and/or recycled material is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of 20 concrete mixtures were prepared and tested. Mixtures were divided into five different groups, with constant water to cementitious material ratio of 0.38, based on the Recycled concrete aggregate (RCA) content: 0, 25, 50, 75, and 100% of coarse aggregate (CA) replaced by RCA. All mixtures were designed to achieve a target slump flow higher than 500 mm (19.7 in). The control mixture for each group was prepared with 100% Portland cement while all other mixtures were designed with 50% of Portland cement substituted by a combination of Supplementary Cementitious Materials (SCMs) such as class C fly ash, and granulated blast furnace slag. Several properties of fresh concrete were investigated in this study such as: flow ability, deformability; filling capacity, and resistance to segregation. Moreover, the compressive strength at 3, 14, and 28 days, the tensile strength, the unrestrained shrinkage up to 90 days and permeability were investigated. Partial replacement of the cement using Supplementary Cementitious Materials resulted in smaller 28-days-compressive strength compared to those of the control mixes. Based on the results of this study, it is not recommended to replace the natural coarse aggregate in self-consolidating concrete by more than 75% of RCA.Although, the partial replacement of cement by Supplementary Cementitious Materials had an adverse effect on the 28-days-compressive strength, most of the mixes have exceeded the SCC minimum requirements, including those with up to 100% RCA. Finally, several mix designs from the study have met the minimum Illinois Department of Transportation (IDOT) compressive strength requirements for several engineering applications such as pavements and bridges. This suggests that a practical application of results from the research is feasible in the near future.</p>

<p> In this dissertation I build theory of the social sustainability of onsite household sanitation infrastructure by leveraging organizational theory, using data collected from rural households in Guatemala and Bangladesh. The overarching research question asks <i>what causes high failure rates in onsite household sanitation systems?</i> This work is important because of the large number of people served by onsite technology types and also because of high observed rates of infrastructure abandonment. Since sanitation technologies are vitally important to public and environmental health, universal coverage is an urgent goal. Unfortunately, it is far from being met. As a first step towards addressing this problem, I use a literature review and expert panel to identify factors important to the sustainability of sanitation infrastructure. This work (Chapter 2) identified the importance of social factors and also showed that interactions between various factors explained the contention regarding the importance of ten factors. As such, the rest of my research focused on the topic of social sustainability, with the methodological goal of retaining attention to complexity. To build theory of social sustainability I use constructs of legitimacy and status from organizational theory. While organizational theory has never before been applied to infrastructure systems, it deals with groups of people using technology to achieve shared goals, and this is precisely what we see with infrastructure. I analyze household level interview data from Bangladesh using crisp set Qualitative Comparative Analysis to describe sanitation abandonment as a form of organizational decoupling (Chapter 3) by contrasting households with socially sustainable or socially unsustainable infrastructure. This research shows that neither a lack of demand nor economic barriers caused sanitation abandonment in the communities selected for this research. Instead the causal mechanism is decoupling, which is founded on perceptions of efficiency (whether or not desired infrastructure services are actually achieved) and competing rational myths (beliefs regarding how and why things ought to be done). This analysis leads us to suggest that, due to the impact on social sustainability, odor management should be required in the updated definition of improved sanitation as we revise and replace the Millennium Development Goals. This research also empirically identifies pathways that Guatemalan households took to achieve socially sustainable sanitation infrastructure (Chapter 4). The most practically useful of these shows that the combination of consequential legitimacy (a moral understanding of outcomes) and comprehensibility legitimacy (a cognitive model connecting outcomes to processes) leads to a socially sustainable outcome in a full 50% of the household cases studied for this work. Taken together, these findings explain and will allow us to better design sanitation infrastructure, technical knowledge mobilization, and educational outreach to support socially sustainable infrastructure.</p>

<p> Rural communities in developing countries are most vulnerable to the plight of requiring repeated infusions of charitable aid over time. Micro-business opportunities that effectively break the cycle of poverty in resource-rich countries in the developing world are limited. However, a strong model for global commerce can break the cycle of donor-based economic supplements and limited local economic growth. Sustainable economic development can materialize when a robust framework combines engineering with the generous investment of profits back into the community. This research presents a novel, systems-based approach to sustainable community development in which a waste-to-resource methodology catalyzes the disruption of rural poverty. </p><p> The framework developed in this thesis was applied to the rural communities of Cagmanaba and Badian, Philippines. An initial assessment of these communities showed that community members are extremely poor, but they possess an abundant natural resource: coconuts. The various parts of the coconut offer excellent potential value in global commerce. Today the sale of coconut water is on the rise, and coconut oil is an established $3 billion market annually that is also growing rapidly. </p><p> Since these current industries harvest only two parts of the coconut (meat and water), the 50 billion coconuts that grow annually leave behind approximately 100 billion pounds of coconut shell and husk as agricultural waste. Coconuts thus provide an opportunity to create and test a waste-to-resource model. Intensive materials analysis, research, development, and optimization proved that coconut shell, currently burned as a fuel or discarded as agricultural waste, can be manufactured into high-grade coconut shell powder (CSP), which can be a viable filler in polymeric composites. </p><p> This framework was modeled and tested as a case study in a manufacturing facility known as a Community Transformation Plant (CTP) in Cagmanaba, Philippines. The CTP enables local creation of globally viable products from agricultural waste. This researcher seeks to encourage the propagation of CTPs throughout developing communities worldwide, each profiting from its own waste-to-resource value.</p>