The Port of Houston and the Houston Ship Channel (HSC) are highly industrialized areas along Galveston Bay, Texas. The HSC is highly polluted with a host of persistent organic pollutants, including dioxins. The main objective of this study was to determine the potential for in situ bioremediation in the HSC sediments. Our study focused on the bacterial group Dehalococcoides, since it is the only known group to reductively dechlorinate dioxins. Culture independent methods were used to determine the presence or absence of Dehalococcoides in HSC sediments. Molecular methods including PCR, cloning, restriction enzyme digest, and sequencing were used to determine the diversity of Dehalococcoides as well as total bacterial diversity in HSC sediments. The metabolically active members of the microbial community in HSC sediments were also determined using the same molecular methods as described above. Dehalococcoides was detected in every sediment core and at various depths within each core. Depths ranged from 1cm (SG-6) to 30cm (11261). Dehalococcoides diversity was centered on Dehalococcoides ethenogenes strain 195 and Dehalococcoides sp. strain CBDB1. Overall bacterial diversity in HSC sediments was dominated by Proteobacteria, especially Deltaproteobacteria, and Chloroflexi, which include Dehalococcoides. Total bacterial diversity at a wetlands control site was dominated by Betaproteobacteria and Acidobacteria. Deltaproteobacteria and Chloroflexi were determined to be the major metabolically active groups within the HSC sediments. These findings indicate that the HSC sediments have great potential for successful in situ bioremediation. These results also support the use of Dehalococcoides as a biological proxy for dioxin contamination.

Urban centers are major sources of contaminants to the surrounding air, water and soils. Above all, combustion-derived carbonaceous aerosols, especially black carbon (BC) and associated polycyclic aromatic hydrocarbons (PAHs), make significant contributions to the pollution in these systems. Here sedimentary records are used to produce a series of historical reconstructions of such contaminants to the Houston Ship Channel (HSC) system and compare these to point source inputs of hydrophobic organic contaminants (HOC). Analytical data on total organic carbon (TOC), BC, PAHs, dioxins and lignin (likely discarded from a pulp and paper mill along the Channel) were determined. This multi-proxy approach revealed that over the last several decades, HOC inputs to the system have been derived from a complex mixture of combustion processes, industrial point-sources, and oil spills. In particular, widespread dioxin contamination was observed throughout the study region with a particular site of the HSC showing total concentrations over 20,000 pg/g and 5000 pg toxic equivalent (TEQ)/g dry weight of sediment. Using two models based on sorption constants of total OC and BC, porewater concentrations were estimated to be lower than expected, at 20 pg/L and 5 pg TEQ/L. These values, however, are recognized as being extremely high for freely dissolved concentrations in porous media. The pulp and paper waste pit has recently been declared a Superfund site based on dioxin concentrations alone. The relationship between lignin biomarkers and dioxins observed in these sediments confirms that discharges of pulp and paper effluents were responsible for such high dioxin levels. Concentrations of BC, amorphous OC, and TOC were then used to calculate sediment binding of dioxins in sediments of the HSC. Our study found BC to be extremely low in HSC sediments (0.04 to 0.20%) indicating minimal dioxin sorption capacity. This suggests strong potential for fluxes of dioxins from sediments to the water column both through passive diffusion and physical mixing during natural and anthropogenic sediment remobilization events in this shallow system (hurricanes, storms, and dredging). The purposeful addition of BC to these sediments might be promising as a remediation strategy.

This thesis seeks to challenge the dominant narrative that oil has been a positive contributor to Houston's development as a city by exploring the real lived consequences for those who live along the Houston Ship Channel--the home of Houston's oil industry. This is done through an examination of historical processes which look at how a pro-oil sentiment has been intertwined into Houston's identity juxtaposed to the historical processes which have shaped the lives of communities near the Houston Ship Channel. This thesis then ends by delving into how it is difficult to organize around the environment in Texas because of how much influence oil has on the state politically and physically.

Despite federal, state, and local efforts to combat environmental injustices resulting from heavy industrial activity and high air pollution levels, there is a widespread tendency for hazardous industrial activities to locate near low-income, underrepresented ethnic populations in the United States. The Houston Ship Channel, a port containing the largest concentration of Petrochemical Facilities in the United States, evidences this tendency and provides a stellar example of the nexus between poverty, race, industrial location, and air pollution levels. As a result of the heavy industrial activities in the East Houston area adjacent to the Houston Ship Channel, the surrounding residential area’s air quality levels are significantly poor in relation to federal, state, and local standards. Not coincidentally, these neighborhoods are predominantly low-income and Hispanic in makeup. Unfortunately, there exist few or no federal or state accountability and enforcement mechanisms to resolve this serious problem. In addition, Houston’s lack of zoning and weak land use regulations provides little opportunity for the situation to improve. Although community organization efforts have succeeded in terms of mobilization, education, and consensus building, more effective local planning tools, supported by federal regulations and applied research, would serve to remove the roadblocks that have hindered the advancement of policies promoting enhanced air quality controls, and thus improve the quality of life of the residents of East Houston. / text

Resiliency measurement is a great tool for evaluating system performance and proposing solutions to prevent damage and to recover from disruptive events. This study proposes an analytic approach to quantify narrow waterway systems’ resiliency during disasters. First, metrics are introduced to quantify the resiliency before, during, and after a disruption. The existing Key Performance Indicators (KPIs) for Maritime Transportation Systems (MTS) are examined, and two metrics, 1) the number of inbound and outbound vessels and 2) Total Stopped Vessel-Hours, are selected to measure the resiliency of a waterway system. Second, a heuristic method is developed to derive the KPIs from the Automatic Identification System (AIS) data. Finally, the proposed methodology is performed for the Houston Ship Channel (HSC) AIS data before, during, and after Hurricane Harvey, in August 2017. The results are presented for the entire channel and highlight useful information about the performance of individual docks, terminals, and waterway zones within HSC. This study helps decision-makers identify the weaknesses and potential bottlenecks in a waterway confronting a disruption and come up with remedies.