Center for Earth Systems Engineering and Management

The objective of this work is to perform LCAs three wastewater treatement alternatives at battalion-sized (500 soldier) FOBs. Three systems will be explored: traditional wastewater treatment of combined blackwater and graywater streams using activated sludge and anaerobic digestion (the status quo); MXC treatment of blackwater to produce H2O2 for disinfection of blackwater and graywater; a hybrid system of blackwater treatments with MXCs to produce electricity with graywater disinfection using H2O2 produced offsite. Environmental impacts are assessed using Impact 2002+ midpoint and endpoint categories, primarily reported for human health and environmental impacts. Uncertainity analysis is performed using two techniques. First, a pedigree matrix is developed to identify the highest areas of uncertainties in data. Second, a sensitivity analysis is used to explore the effects on endpoint categories from varying transportation distance, the percentage of wastewater that is reused as nonpotable water, and coagulant doses.

In the economic crisis Detroit has been enduring for many decades, a unique crisis has emerged with the provision of water that is normally not seen in the developed world. The oversized, deteriorating, and underfunded water provision system has been steadily accruing debt for the water utility since population began to decrease in the 1950s. As a result, the utility has instated rate increases and aggressive water shut off policies for non-paying residents. Residents have consequentially claimed that their human right to water has been breeched.

In this report, I analyze possible solutions to the water crisis from both the water utility and resident perspectives. Since all utility management solutions have very serious limitations on either side of the argument, I have chosen a set of technologies to consider as a part of an impact mitigation plan that can provide alternative sources of water for the people who no longer can rely on municipal water. I additionally propose an adaptive management plan to evaluate the effects of using these technologies in the long-term. The monitoring of the effects of technological mitigations might also help determine if sustainability (efficiency and equity) could be an attainable long-term solution to Detroit’s water crisis.

There is increasing evidence that vehicle travel in developed countries may have peaked, contradicting many historical travel demand forecasts. The underlying causes of this peaking are still under debate and there has been a mobilization of research, largely focused at national scales, to study the explanatory drivers. There is, however, a dearth of research focused at the metropolitan scale where transportation policy and planning are frequently decided.

Using Los Angeles County, California, as a case study, we investigate the Peak Car theory and whether social, economic, and technical factors, including roadways that have become saturated at times, may be contributing to changes in travel behavior. After peaking in 2002, vehicle travel in Los Angeles County declined by 3.4 billion (or 4.1%) by 2010. The effects of changing fuel prices, fuel economy, population growth, increased utilization of alternate transportation modes, changes in driver demographics, income, and freight are first assessed. It is possible, and likely, that these factors alone explain the reduction in travel. However, the growth in congestion raises questions of how a constricting supply of roadway network capacity may contribute to travel behavior changes.

There have been no studies that have directly assessed how the maturing supply of infrastructure coupled with increasing demand affect travel behavior. We explore regional and urban factors in Los Angeles to provide insight into the drivers of Peak Car at city scales where the majority of travel occurs. The results show that a majority of the decline in VMT in Los Angeles can be attributed the rising fuel prices during the 2000s. While overall roadway network capacity is not yet a limiting factor for vehicle travel there is some evidence that suggests that congestion along certain corridors may be shifting some automobile travel to alternatives. The results also suggest that the relative impact of any factor on travel demand is likely to vary from one locale to another and Peak Car analysis across large geographic areas obscures the nuisances of travel behavior at a local scale.

With potential for automobiles to cause air pollution and greenhouse gas emissions relative to other modes, there is concern that automobiles accessing or egressing public transportation may significantly increase human and environmental impacts from door-to-door transit trips. Yet little rigorous work has been developed that quantitatively assesses the effects of transit access or egress by automobiles.

This research evaluates the life-cycle impacts of first and last mile trips on multimodal transit. A case study of transit and automobile travel in the greater Los Angeles region is developed. First and last mile automobile trips were found to increase multimodal transit trip emissions, mitigating potential impact reductions from transit usage. In some cases, a multimodal transit trips with automobile access or egress may be higher than a competing automobile trip.

In the near-term, automobile access or egress in some Los Angeles transit systems may account for up to 66% of multimodal greenhouse gas trip emissions, and as much as 75% of multimodal air quality impacts. Fossil fuel energy generation and combustion, low vehicle occupancies, and longer trip distances contribute most to increased multimodal trip impacts. Spatial supply chain analysis indicates that life-cycle air quality impacts may occur largely locally (in Los Angeles) or largely remotely (elsewhere) depending on the propulsion method and location of upstream life-cycle processes. Reducing 10% of transit system greenhouse emissions requires a shift of 23% to 50% of automobile access or egress trips to a zero emissions mode.

A corresponding peer-reviewed journal publication is available here:
Greenhouse Gas and Air Quality Effects of Auto First-Last Mile Use With Transit, Christopher Hoehne and Mikhail Chester, 2017, Transportation Research Part D, 53, pp. 306-320,