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This paper investigates strategies that could achieve an 80% reduction in transportation emissions from current levels by 2050 in the City of Philadelphia. The baseline daily lifecycle emissions generated by road transportation in the Greater Philadelphia Region in 2012 were quantified using trip information from the 2012 Household Travel Survey (HTS). Emissions were projected to the year 2050 accounting for population growth and trends in vehicle technology for both the Greater Philadelphia Region and the City of Philadelphia. The impacts of vehicle technology and shifts in travel modes on greenhouse gas (GHG) emissions in 2050 were quantified using a scenario approach. The analysis of 12 different scenarios suggests that 80% reduction in emissions is technically feasible through a combination of active transportation, cleaner fuels for public transit vehicles, and a significant market penetration of battery-electric vehicles. The additional electricity demand associated with greater use of electric vehicles could amount to 10.8 TWh/year. The use of plug-in hybrid electric vehicles (PHEV) shows promising results due to high reductions in GHG emissions at a potentially manageable cost. [ABSTRACT FROM AUTHOR]

Participatory engineering has been called for after major catastrophes, yet is often bypassed due to countervailing implementation of ‘quick fixes’. While immediate expert-driven solutions may be attractive, in the long-term they may be ineffective and inconsistent with the goals and capacities of local stakeholders. This article discusses the findings of National Science Foundation research by a team of three engineers and one social scientist who visited Haiti twice, four and seven months after the January 2010 earthquake, to investigate community participation in water and sanitation engineering processes in Léogâne. Methods included interviews with local inhabitants, water-sector actors, and government agencies; inspections of the engineering of the existing water and sanitation system; surveys of the affected population; and a participatory workshop to which numerous community-based organizations were invited. The research tests the potential for engineers to develop stakeholder-based participatory processes in a post-disaster context, which is hypothesized to produce better outcomes than traditional top-down authoritative planning processes. Focusing on the sanitation sector within a multi-stakeholder arena, the article analyzes the potential for various kinds of interactions amongst actors during unfolding decision-making processes at multiple scales, and assesses how each might contribute to better post-disaster engineering and ultimately more sustainable water and sanitation systems. [ABSTRACT FROM PUBLISHER]

The Haitian government passed a law in 2009 to decentralize water utility management and improve cost recovery. This study identifies the attitudes of the public towards payment for and management of water and sanitation, several months after the 2010 earthquake, through a survey (N = 171) and semi-structured interviews (N = 19) in Leogane, Haiti. A majority of survey respondents were willing to pay for water and sanitation, which aligns with the fee-based approach of the 2009 law. Significant differences were found between geographic locations, suggesting that a neighbourhood-level approach to water and sanitation is appropriate. [ABSTRACT FROM AUTHOR]

In the wake of the 2001 terrorist attacks, the use of Bacillus anthracis (anthrax) in bioterrorism attacks has emerged as a realistic concern. Thus, a contingency plan is needed to inform decision-makers about which response actions are appropriate and justified under which circumstances. This study considers the decisions: (1) to undertake prophylactic antibiotic treatment; (2) to vaccinate individuals; or (3) to decontaminate the building. While these response actions are clearly justified for highly exposed individuals, a very large number of individuals exposed to very small risks in areas outside of the immediate vicinity of the release are also likely. Our results indicate that there are non-negligible risk thresholds below which response actions produce more costs than benefits. For the base case, the thresholds range from a risk of 1 in 33 for decontamination by fumigation to 1 in 6,547 for antibiotic prophylaxis and 1 in 7,108 for vaccination. A one-way sensitivity analysis on uncertain variables indicates less than an order of magnitude change in these thresholds. Benefit-cost analysis is a useful tool for assessing tradeoffs among alternative decisions, but cannot be the sole criterion in responding to incidents because of inherent limitations. [ABSTRACT FROM AUTHOR]

The current framework for U.S. Environmental Protection Agency regulation of water quality in community drinking water supplies produces sequential rules for either single contaminants or small groups of similar contaminants. For both substantive and pragmatic reasons, some water industry experts have advocated the development of a more holistic regulatory process in which rules are promulgated less frequently but for larger contaminant classes. Such a framework would require the expansion of existing regulatory evaluation technologies to account for joint occurrence distributions of multiple contaminants. This article presents an analysis, using two national contaminant databases, of the joint distributions of seven contaminants (arsenic, nitrate, uranium, manganese, magnesium, calcium, and sulfate) in community water system source waters. Inferences are based on a flexible Bayesian hierarchical modeling structure with numerous features desirable for empirical exploration of multicontaminant regulations, including the simultaneous estimation of spatial heterogeneity in contaminant levels and covariations among contaminants, applicability to sparse data collected over a large spatial scale, and coherent assimilation of information provided by censored observations. The model is used to estimate a family of joint distributions for the contaminants indexed by water system characteristics, with empirically appropriate complexity given the resolution of the available data. The resulting distributions provide insights about the nature of, and uncertainty about, contaminant co-occurrence patterns, quantify the impact on national assessments of jointly modeling the contaminants, and facilitate identification of critical classes of water systems where uncertainty is highest. [ABSTRACT FROM AUTHOR]