Theses and Dissertations at Montana State University (MSU)
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Item Analysis of cleanups of lead-contaminated residential soils at u.s. smelter superfund sites(Montana State University, 2021) Tan, RobertLead contamination from historic smelting operations continues to pose a public health risk in the United States, particularly from exposure to contaminated soils. Epidemiological studies have shown that concentrations of lead in residential soils can result in unacceptable exposures, and that there is no apparent blood lead concentration that may entirely avoid adverse health effects. These findings have caused regulatory agencies to gradually reevaluate previous blood lead targets and cleanup levels for lead sites. The U.S. Environmental Protection Agency (EPA), which is responsible for conducting cleanups of large-scale lead smelting sites that are on the National Priorities List, has acknowledged current literature that demonstrates risks from trace exposures, but has not yet revised the 1994 blood lead level target of 10 ?g/dL. This ambiguity is coupled with regional delegations of authority that have resulted in varied approaches to addressing lead contamination within the Superfund program. These inconsistencies create a challenge to remedial project teams tasked with determining strategies to address these future sites. I address this challenge by conducting a first-of-its-kind comprehensive evaluation of residential cleanups at lead smelter Superfund sites. By using publicly available data from decision documents for 31 lead smelter sites across the US, I identify predominant cleanup strategies. Although the evaluations demonstrate inconsistent blood lead targets and cleanup levels used between sites, they also illustrate commonalities in the type of remedy selected as well as general costs for residential cleanups conducted by EPA's removal and remedial programs. My results indicate that remedial project teams should embrace strategies that use both removal and remedial actions to address residential soil contamination and should expect to select a remedy based on excavation and backfill of contaminated properties. Soil amendments may be able to reduce lead bioavailability but have only been used for residential properties at one site and were unable to achieve residential cleanup standards. Last, my paper provides average preliminary cost estimates for residential cleanups, ranging from $434 per yd3 removal actions, and $125 per yd3 for remedial actions. Although costs differ substantially between sites, these general estimates provide a starting point for early planning efforts.Item Water quality impacts from leaking coal ash ponds at two superfund sites(Montana State University, 2020) Rozwara, Aeriel Kyra; Chairperson, Graduate Committee: Miranda MargettsCoal is a fossil fuel used worldwide for energy production. Although coal is a plentiful and cost-efficient source of energy, the by-product of coal production, coal ash, poses environmental and human health risks. My analysis involved the identification and comparison of concentrations of thallium, manganese, and arsenic contamination at two Superfund managed sites that experienced a leak of coal ash ponds. I also examined the potential role that public awareness and risk management approaches undertaken at each site to contain the effect of the contamination may have played in mitigating the extent of the risk impacts. The Kingston Tennessee Valley Authority (TVA) coal ash spill received national media coverage and occurred over a large visible area in a relatively short time frame (December 2008 - December 2014). In contrast, the coal ash spill at Town of Pines received limited media attention and occurred slowly over many years (April 2000 - present). As a result, the spill remained unknown to many residents in neighboring counties. To investigate the efficacy of the implemented mitigation measures, I compared both the risk management approach to containing the spills, and the contaminant concentrations (arsenic, manganese, and thallium) at each site over time. Overall, the TVA coal ash spill received a relatively fast, intensive containment, reflected by contaminant values reduced to below EPA threshold levels within a matter of months. The visible extent of the spill was shared extensively by the media . Conversely, my analysis of the Town of Pines spill, which remained unknown to residents and received limited media attention, highlighted that although concentration values have decreased over a 15-year timeframe, some concentrations remain at harmful levels. The results of my study demonstrate the influence of public awareness and subsequent community pressure on the timeliness of remediation measures and reduction of overall environmental and human health risks from coal ash spills.Item Development of GIS/GPS methodology of minesite soil salvaging(Montana State University - Bozeman, 1994) Lindberg, Steven Dennis; Chairperson, Graduate Committee: D. J. DollhopfItem Processes affecting solute transport through soils : preferential flow and microbial degradation(Montana State University - Bozeman, College of Agriculture, 1997) Langner, Heiko WalterItem Effect of two dolomitic industrial by-products on pH control, leachate chemistry and plant response in acidic-metalliferous mine waste(Montana State University - Bozeman, College of Agriculture, 1997) Kelly, Laureen SusanItem Sulfate reduction and carbon oxidation in model constructed wetlands for metal remediation(Montana State University - Bozeman, College of Engineering, 2000) Sturm, Jason RichardItem The bioavailability of selected aromatic hydrocardons : an extension from saturated to variably saturated soils(Montana State University - Bozeman, College of Engineering, 1995) Peccia, Jordan LeeItem Isolation, characterization and copper binding of Gaeumannomyces graminis var. graminis melanin mutants(Montana State University - Bozeman, College of Agriculture, 1997) Frederick, Barbara AnneItem Biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and pentachlorophenol (PCP) in soils(Montana State University - Bozeman, College of Agriculture, 1997) Doughten, Ronald AllenItem Biological and geochemical controls on CO2 equilibria in free water wetlands(Montana State University - Bozeman, College of Engineering, 1999) Sharp, Thomas Robert