Physical Sciences and Mathematics Commons^™

Hydrogeologic Model Of A Leachate Plume In An Unconfined Coastal Plain Aquifer And Chemical Transport Mechanisms Of Metals And Dense Non-Aqueous Phase Liquids, Thomas Lindblad

Theses and Dissertations

Groundwater contamination is of increasing environmental concern as many aquifers across the globe have experienced a decrease in water quality in recent time. The growth of the world's population over the last couple of decades has caused a dramatic increase in the rate of groundwater use. One potential source of groundwater contamination is waste material in landfills. The 1 st Division Road Sanitary landfill at Fort Benning Military Reservation was studied to evaluate the potential effect on local groundwater and a leachate plume was recognized using data from 16 groundwater monitoring wells located around the facility. The study site is …

Pluton Zonation Unveiled By Gamma-Ray Spectrometry And Magnetic Susceptibility; A Case Study Of The Sheeprock Granite, Western, Utah, Paul D. Richardson

Theses and Dissertations

A radiometric survey of the zoned 21 Ma, A-type Sheeprock granite, western Utah, combined with measurements of magnetic susceptibility and field observations were analyzed using a geographic information system. The intrusion spans 25 square km and is roughly eliptical in shape with its long axis trending northwest. Concentration maps (composed of more than 500 survey stations) of eU, eTh, texture, magnetic susceptibility, color, and joint density help to constrain magmatic and post-magmatic processes related to its chemical and physical zonation. Uranium ranges from 3.9 to 26.9 ppm (mean 12.7) and thorium from 1.7 to 125.7 ppm (mean 45.5). Similarities in …

A Cost Effective Approach To Taxonomic Resolution For Bioassessment And Monitoring Programs In The State Of Georgia, Jodi Alene Williams

Theses and Dissertations

The Georgia Ecoregions Reference Sites Project has developed biological criteria for streams in Georgia according to the Rapid Bioassessment Protocols For Wadeable Streams and Rivers. Streams will ultimately be classified into categories of impairment so that management decisions can be made in accordance with the Clean Water Act. A cost-effective approach to accomplish mandates set forth by the Clean Water Act must be employed, as state budgets are limited. One means of examining costs is to assess taxonomic resolution. Taxonomic resolution not only assesses the sensitivity of biocriteria, it also allows one to make recommendations to state agencies regarding the …

The Occurrence And Control Of Disinfection By-Products (Dbps) In Two Water Treatment Plants Utilizing The Same Source, Sam George Khoury

Theses and Dissertations

The influence of disinfection by-products (DBPs) on the operation and design of water treatment plants has been increasing since the early studies by Rook on trihalomethanes (THMs) (Stevens, 1977). Work conducted in the 1980s identified the existence of nonvolatile halogenated organics (non-THM organics), of which the majority produced by chlorination were haloacetic acids (HAAs), within the HAAs, dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were the dominant members. Concern over potential health effect led the U.S. Environmental Protection Agency (USEPA) to set a maximum contaminant level (MCL) for total THMs and HAAs. The disinfectant/disinfection by-product rule (D-DBP Rule) currently proposed …

Platinum Group Element Mineralization In "Ballrooms" Of The J-M Reef Of The Stillwater Complex, Montana, Matthew P. Harper

Theses and Dissertations

The J-M Reef of the Stillwater Complex, Montana (a large layered mafic intrusion), is one of the highest grade platinum group element (PGE) deposits known in the world, producing primarily palladium and platinum in a 3.4:1 ratio. "Ballrooms" of the Stillwater Complex are anomalously wide areas within or stratigraphically below the J-M Reef that host platinum group element mineralization. Ballrooms have two typical morphologies (type 1 and type 2); the first is an abrupt thickening of the mineralization that extends below the Reef Package and the second is a gentle widening of the Reef Package and associated reef mineralization to …

The Impact Of Urbanization On Macroinvertebrate Communities Of Creeks Within Western Georgia, Jeniffer Susan Lang

Theses and Dissertations

Urbanization is a major cause of stream impairment in the United States, altering stream ecological integrity in a variety of ways. While control of point source pollution has largely improved over the last twenty years, the control of non-point source pollution has proved to be more of a challenge. Urbanization in the area surrounding streams has been linked with elevated levels of sediment, heavy metals, organic matter, and nutrients within streams, as well as with other negative effects. Examining the macroinvertebrate communities within streams has proven to be an effective indicator of the effects of urbanization on water quality. This …

Terrestrial Movements And Habitat Use Of Gopher Frogs (Rana Capito) At Fort Benning, Georgia, Jonathan H. Neufeldt

Theses and Dissertations

Gopher frogs (Rana capito) were radio-tracked between the 2000 and 2001 breeding seasons to study their terrestrial movements and habitat use in a longleaf pine- sandhill area on the Fort Benning Military Reservation, Georgia. The telemetry research was conducted in response to the need for biological data concerning gopher frog terrestrial habits. Ultimately the data could aid biologists and land managers in describing critical habitat and the development of a management or recovery plan. Twelve gopher frogs were caught at a herpetofaunal array surrounding two neighboring breeding ponds during a post breeding migration, implanted with miniature transmitters, released and radio-tracked …

A Boundary Element Method For Thermo-Poroelasticity With Applications In Rock Mechanics, Qiang Zhang

Theses and Dissertations

Coupled thermal and poromechanical processes play an important role in many geomechanics problems, such as borehole stability analysis and studies of initiation and propagation of hydraulic fractures. Thermal effects, as well as hydraulic effects, can greatly change the stresses and pore pressure fields around an underground opening. This is due to the fact that thermal loading induces a volumetric deformation because of thermal expansion/contraction of both the pore fluid and the rock solid. Volumetric expansion can result in significant pressurization of the pore fluid. In order to take into account the influence of temperature gradients on pore pressure and stresses, …

Modeling The Hydrogeochemistry Of Denitrification In The Elk Valley Aquifer, Paul A. Skubinna

Theses and Dissertations

Nitrate (NO₃¯) in groundwater has become an important tissue in the last few decades. It is known to cause methemoglobinemia, commonly known as “blue baby syndrome,” and is suspected of being a carcinogen. The most common sources for dissolved NO₃¯ in shallow groundwater include excessive application of nitrogenous fertilizers, misuse of septic systems, improper disposal of domestic wastewater or sludge, and livestock waste.

Denitrification is the most effective sink for NO₃¯. The Elk Valley aquifer (EVA) of eastern North Dakota is known to support denitrification. The objective of this study was to gain a better understanding of the geochemical processes …

Design And Evaluation Of A Modified In Situ Mesocosm To Study Denitrification In The Karlsruhe Aquifer, Jason M. Warne

Theses and Dissertations

To simplify the in situ mesocosm (ISM) design given in Schlag (1999), a modified ISM was designed and built in which a 6-inch long sand point replaces three 16-inch diameter screens. The modified design also includes an optional submersible pump mounted on top of the ISM chamber, making it capable of applications at depths greater than those attainable using a peristaltic pump from the ground surface. Two ISMs, one the original design (0-ISM) and the other the modified design (M-ISM) with an optional submersible pump, were installed in the Karlsruhe aquifer, near Minot, ND, in late June, 2003. Tracer tests …

Discontinuities In The Icebox Formation (Ordovician), Williston Basin, North Dakota And Montana, Aaron J. Ulishney

Theses and Dissertations

The Ordovician Winnipeg Group is composed of three formations; in ascending order, the Black Island Formation, the Icebox Formation, and the Roughlock Formation. The Icebox Formation is largely composed of shale. This work shows that discontinuities and coarser facies exist within the Icebox Formation and that they are traceable throughout the subsurface of North Dakota and eastern Montana. This work also illustrates possible sea-level changes during the deposition of the Icebox Formation along with probable source areas providing detrital sediments into the study area.

Gamma-ray wireline logs were used to distinguish the formations of the Winnipeg Group from each other, …