Physical Sciences and Mathematics Commons^™

A Groundwater Model Of The San Luis Obispo Valley Basin Using Comsol Multiphysics, Brian Whetsler

Master of Science in Environmental Sciences and Management Projects

A groundwater model of a subsection of the San Luis Obispo Valley basin was pro- duced using COMSOL Multiphysics 5.5 software. The goal of this project was to create a general model using forward modeling techniques which would serve as the foundation for a more refined, complete, and calibrated groundwater hydrology model. The San Luis Obispo and Edna Valley basins are characterized as high-priority by the California Sustainable Groundwater Management Act because of historic overdrafting of groundwater reserves during periods of drought in the early 1990's. Natural resource managers must use tools such as computer models to help forecast trends …

Water Chemistry And Lake Dynamics Of Laguna Bacalar, Quintana Roo, Mexico, Ryan Matzuk

Theses and Dissertations

Laguna Bacalar in the Quintana Roo region is the second largest lake in Mexico and contains freshwater derived solely from groundwater. Local geology on the Yucatan Peninsula is karstic and the southern shoreline of Laguna Bacalar is spotted with a handful of cenotes that contribute substantial amounts of inflowing groundwater to the lake. This is shown by sonde profile data taken in one of the largest cenotes in the area. Outflow is dominated by a surface water outlet in the southern portion of the lake and an unknown amount of outflowing groundwater. During January of 2017 through 2019, UWM researchers …

Nitrate Dynamics And Source Within Nested Watersheds Of An Agricultural Stream, Nebraska, Usa, Galen Richards

School of Natural Resources: Dissertations, Theses, and Student Research

Nitrate concentrations have been increasing throughout the globe, primarily due to heightened agricultural activity. Nitrate concentrations in Bazile Creek, located in Northeastern Nebraska, have been steadily rising since the early 2000s. Groundwater nitrate concentrations within the Bazile Creek watershed are high (> 10 mg/L nitrate-N), and there is strong connectivity between groundwater and surface water systems. This study aimed to better understand temporal nitrate concentration variability within the watershed through sampling tributaries and the main channel during baseflow conditions. Nitrate source was also investigated though the use of dual δ¹⁵N and δ¹⁸O nitrate isotopes, with samples …

High-Resolution Timeseries Analysis Of Dynamic Geochemistry: A 27-Well Survey Of Contaminated Groundwater Downstream Of The Former S-3 Ponds, Oak Ridge, Tennessee, Emma Dixon

Masters Theses

Spatiotemporal variability of geochemistry of contaminated groundwater has large implications on overall water quality and ability to respond to remedial applications. Gaining knowledge of how geochemistry changes over time in an area can help establish response trends to changing external conditions like weather and level of contamination. In this study, a spatiotemporal survey was performed on 27 wells at the Y-12 Complex in Oak Ridge, Tennessee. This was completed to measure diurnal fluxes in geochemistry from seasonal changes and extreme weather conditions in three areas of historically different contamination levels from a single point contamination source. Measurements were gathered over …

A Geochemical And Statistical Investigation Of The Big Four Springs Region In Southern Missouri, Jordan Jasso Vega

MSU Graduate Theses

The Big Four Springs region hosts four major first-order magnitude springs in southern Missouri and northern Arkansas. These springs are Big Spring (Carter County, MO), Greer Spring (Oregon County, MO), Mammoth Spring (Fulton County, AR), and Hodgson Mill Spring (Ozark County, MO). Based on historic dye traces and hydrogeological investigations, these springs drain an area of approximately 1500 square miles and collectively discharge an average of 780 million gallons of water per day. The rocks from youngest to oldest that are found in Big Four Springs region are the Cotter and Jefferson City Dolomite (Ordovician), Roubidoux Formation (Ordovician), Gasconade Dolomite …

Evaluation Of Groundwater Sodium And Sodium Uptake In Taxodium And Its Hybrids On Galveston Island, Texas, Daniel Morgan

Electronic Theses and Dissertations

In September 2008, Hurricane Ike swept through the Gulf of Mexico striking the Gulf Coast, claiming hundreds of lives and causing billions of dollars in damage. The hurricane left behind elevated sea salt concentrations in the soil and groundwater, preventing the unaided return of live oaks and other species to the island. To determine effective ways to ameliorate the elevated Na⁺ concentrations in the soil, eight treatments were applied to the soil and combinations of three species of plants, live oak (Quercus virginiana), hybrid bald cypress (Taxodium ‘T406’), and yellow hibiscus (Hibiscus hamabo …

Groundwater Storage Loss Associated With Land Subsidence In Western United States Mapped Using Machine Learning, Ryan G. Smith, Sayantan Majumdar

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Land subsidence caused by groundwater extraction has numerous negative consequences, such as loss of groundwater storage and damage to infrastructure. Understanding the magnitude, timing, and locations of land subsidence, as well as the mechanisms driving it, is crucial to implementing mitigation strategies, yet the complex, nonlinear processes causing subsidence are difficult to quantify. Physical models relating groundwater flux to aquifer compaction exist but require substantial hydrological data sets and are time consuming to calibrate. Land deformation can be measured using interferometric synthetic aperture radar (InSAR) and GPS, but the former is computationally expensive to estimate at scale and is subject …

Hydrogeochemical Characterization And Speleogenesis Of Sistema Huautla In Oaxaca, Mexico, Fernando Hernandez

Masters Theses & Specialist Projects

Sierra Mazateca, Mexico is home to Sistema Huautla, the deepest cave in the Western hemisphere with 1,560 meters of depth and 90 kilometers of passage, including 26 entrances distributed in a high-relief, karstified terrain, within the Sistema Huautla Karst Groundwater Basin. Exploration of the cave has generated research questions about its evolution and geomorphology given the different vadose and phreatic zones impacted by tectonic and incision processes. Dye traces during this study of Cueva de La Peña Colorada confirmed it is a fossil resurgence of the cave system. An additional cave, Cueva Elysium, was connected hydrologically in 2019, expanding the …

Climate Change Impacts The Subsurface Transport Of Atrazine And Estrone Originating From Agricultural Production Activities, Renys Enrique Barrios, Simin Akbariyeh, Chuyang Liu, Khalid Muzamil Gani, Margarita T. Kovalchuk, Xu Li, Yusong Li, Daniel D. Snow, Zhenghong Tang, John Gates, Shannon L. Bartelt-Hunt

Nebraska Water Center: Faculty Publications

Climate change will impact soil properties such as soil moisture, organic carbon and temperature and changes in these properties will influence the sorption, biodegradation and leaching of trace organic contaminants to groundwater. In this study, we conducted a modeling case study to evaluate atrazine and estrone transport in the subsurface under current and future climate conditions at a field site in central Nebraska. According to the modeling results, in the future, enhanced evapotranspiration and increased average air temperature may cause drier soil conditions, which consequently reduces the biodegradation of atrazine and estrone in the water phase. On the other hand, …

Estimating Evapotranspiration Of A Riparian Forest Using Sap Flow Measurements, James R. Solum

Master's Theses

To close the water use budget of irrigated agricultural fields in floodplains with substantial riparian corridors, it is necessary to understand groundwater usage by dominant phreatophytic vegetation, particularly when the primary source of water for irrigation comes from groundwater abstraction. We report here results of estimated evapotranspiration (ET) of a riparian forest, which were based on measurements of sap flow in phreatophytic vegetation within a riparian corridor. The riparian corridor was within a study area 75 to 140 meters wide in the lower portion of the Scotts Creek watershed, which is bounded to the west by the Pacific Ocean in …

Promoting The Sustainable Utilization Of Groundwater Resources In Ethiopia Using The Integrated Groundwater Footprint Index, Xinyu Lin

Honors Scholar Theses

The country of Ethiopia is highly vulnerable to human-caused climate change and is already suffering from the effects. The predominately rural population relies heavily on small-scale agriculture, with 78% of households having at least one member engaged in the field, yet staple crops are highly susceptible to droughts and other weather shocks. Total and agricultural GDP growth in the country have been strongly linked to inter-annual rainfall variability, of which Ethiopia has among the highest in sub-Saharan Africa. A decrease in rainfall since the 1970s has been one of the primary causes of low crop yields, and stresses the immediate …

An Analysis Of Groundwater Quality As Sampling Networks Age: The Gaps In Groundwater Monitoring, Angela Leone

Undergraduate Distinction Papers

Groundwater management is an important facet of protecting this important resource. One way that we ensure proper groundwater management is through the regular, long-term monitoring of groundwater wells at waste management sites throughout the country. This study investigates potential changes to groundwater quality attributed to degradation of well construction materials rather than impacts to aquifers from wastes. This assessment was completed using a data analysis of groundwater trends at closed landfill sites. An analysis of fifty-five sites was completed and three sites met our criteria for suitable data history. Due to the lack of suitable data, a more thorough investigation …

An Evaluation Of Bank Storage At Lake Mead Reservoir In The Southwest United States, Jon Woodrow Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A water balance model is employed at Lake Mead to monitor and verify changing hydrology that affects total volume at the reservoir. Bank storage, which is defined as the volume of water captured in permeable lithologic layers subject to changes induced by contact and proximity to an open waterbody, is one component that is updated regularly and is based upon data and methods that were developed in the 1960’s from observations made within the first 30 years of the reservoir's maturation. Since this period, the reservoir has undergone further development and a current understanding of additional hydrologic affects to bank …

Modeling The Contribution Of Poroelastic Deformation To Postseismic Geodetic Signals, Kimberly Mccormack, Marc A. Hesse, Timothy H. Dixon, Rocco Malservisi

School of Geosciences Faculty and Staff Publications

To constrain the poroelastic component of postseismic deformation, we model the subsurface hydrologic response to the Mw 7.6 subduction zone earthquake that occurred on the plate interface beneath the Nicoya peninsula in Costa Rica on 5 September 2012. The model shows that poroelastic relaxation occurs on multiple time scales and the associated deformation can be up to 2 cm for the trench‐perpendicular component. By modeling the time‐dependent deformation associated with poroelastic relaxation, we can begin to remove its contribution from the observed geodetic signal. Inversions for after slip that ignore poroelastic deformation have errors of 10–20% overall and up …

Field And Numerical Evaluation Of Nitrogen Transport From Septic Systems In Surfical Aquifer Systems To Charlotte Harbor, Florida, Tanten T. Buszka

Masters Theses

Shallow water tables in coastal surficial aquifers limit effective treatment of septic effluent which can result in excess nutrient loading into nearby surface water bodies. Approximately 45,000 septic systems in Charlotte County, Florida transmit effluent into an under studied surficial aquifer and contribute to harmful algal blooms and outbreaks of E. coli. An undeveloped field site was characterized using standard hydrogeologic methods, including a one-year duration natural gradient tracer test, to obtain representative lithology of the sandy surficial aquifer and estimates of groundwater velocity, flow directions, effective porosity and dispersion. These data were used to support the development of a …

Nebraska Statewide Groundwater-Level Monitoring Report 2019, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division

The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the total volume of the High Plains Aquifer lies beneath the State. Groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Nebraska’s total groundwater resource is vast, yet it is also vulnerable to natural and anthropogenic changes, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting form the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.

The personnel of the Conservation and Survey Division (CSD) are proud …

Declining Water Resources And Environmental Degradation: A Case Of The Thulokhola Watershed In The Nuwakot District Of Nepal, Durga D. Poudel, Timothy W. Duex

IGC Proceedings (1993-2023)

Climate change alters the hydrology of a watershed through changes on precipitation patterns, extreme rain events, increase on temperatures, degradation of forest and soil resources and drought conditions. Drought conditions create stress on agricultural crops, forests, drinking water supply for human and wildlife as well as water supply for industrial uses. Flooding destroys crops, infrastructures, private properties, and results in loss of life. Climate change impacts both the availability as well as the quality of water resources as extreme rain events tend to alter water infrastructures and pollute water sources.

In Nepal, climate change impacts include degradation of resource and …

Quantification Of Septic System Contribution To Nutrient Loads In Surface Waters, Archana Tamang

Electronic Thesis and Dissertation Repository

Freshwater systems worldwide are threatened by excessive nutrient (nitrogen and phosphorus) loading. This study evaluated the contribution of septic systems to stream nutrient loads in nine subwatersheds. Stream sampling was conducted during low and high discharge conditions, with samples analyzed for total phosphorus (TP), soluble reactive phosphorus (SRP), nitrate (NO₃-N), and acesulfame (ACE; wastewater tracer). Higher septic effluent reached the subwatershed outlets during high discharge conditions. Subwatersheds with newer households had a lower percentage of septic effluent reaching the stream compared with subwatersheds with older households. Seasonal and event-based ACE concentration-discharge relationships revealed that the hydrological pathways delivering …

Recharge Seasonality Based On Stable Isotopes: Nongrowing Season Bias Altered By Irrigation In Nebraska, Mikaela Cherry, Troy E. Gilmore, Aaron R. Mittelstet, Didier Gastmans, Vinicius Santos, John Gates

School of Natural Resources: Faculty Publications

The sustainability of groundwater resources for agricultural and domestic use is dependent on both the groundwater recharge rate and groundwater quality. The main purpose of this study was to improve understanding of the timing, or seasonality, of groundwater recharge through the use of stable isotopes. Based on 659 groundwater samples collected from aquifers underlying Natural Resources Districts in Nebraska, the isotopic composition of groundwater (δ 2H, δ 18O) was compared to that of precipitation by (a) mapping the isotopic composition of groundwater samples and (b) mapping a seasonality index for groundwater. Results suggest that for the majority of the state, …

Under Pressure: Hydraulic Fracturing, Suzanne Miller

Augsburg Honors Review

Modern hydraulic fracturing, or "fracking," is a relatively new technique that has unlocked previously unviable sources of natural gas. It involves the rapid injection of large volumes of fluids into shale formations thousands of feet below the surface to force open fractures, creating pathways for the gas to flow into the well. The recent escalation in fracking operations has already made shale formations a major source of natural gas, but the fracking process could potentially lead to groundwater contamination. This paper explores concerns over the toxic narure of fracking chemicals, the leakage of produced water and natural gas into aquifers, …

Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray

Daugherty Water for Food Global Institute: Faculty Publications

This study combines empirical predictive and economics models to estimate the cost of remediation for domestic wells exceeding suggested treatment thresholds for nitrates. A multiple logistic regression model predicted the probability of well contamination by nitrate, and a life cycle costing methodology was used to estimate costs of nitrate contamination in groundwater in two areas of Nebraska. In south-central Nebraska, 37% of wells were estimated to be at risk of exceeding a threshold of 7.5 mg/L as N, and 17% were at risk of exceeding 10 mg/L as N, the legal limit for human consumption in the United States. In …

Water Use Governance In A Temperate Region: Implications For Agricultural Climate Change Adaptation In The Northeastern United States, Rachel E. Schattman, Meredith T. Niles, Hannah M. Aitken

College of Agriculture and Life Sciences Faculty Publications

Climate change and access to water are interrelated concerns for agriculture and other sectors, even in temperate regions. Governance approaches and regulatory frameworks determine who has access to water, for what purpose, and when. In the northeastern United States, water governance has historically been conducted by states through a combination of statutory guidance and common law. However, it is unclear what effect if current governance approaches will be sufficient for achieving resource conservation and equitable allocation in a changing climate. To provide insight into these issues, we conducted the first review of freshwater governance in the 12 states that comprise …

Detecting Groundwater Discharge In The Clark Fork River Near Stone Container Using Spectral Alpha Decay Detection For Dissolved Radon In Surface Water Samples Abstract, Daniel William Forsland

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Radon-222 (²²²Rn) was measured along 8.7 kilometers of the Clark Fork River, between Harper’s Bridge and Frenchtown, MT. Twelve water samples were taken along the stretch. Samples 1 through 4 and 10 through 12 were collected on a 1 km interval, samples 5 through 9 were taken on a 500 meter interval. Samples were analyzed for dissolved ²²²Rn using a RAD7 spectral alpha decay detector. Instream ²²²Rn was modeled to quantify groundwater discharge to the river. Literature on the Missoula Valley aquifer was analyzed, revealing an alluvial aquifer system to the east consisting of interbedded gravel, …

Tracing Sources Of Natural Organic Matter, Trihalomethanes And Metals In Groundwater From A Karst Region, Connie O'Driscoll, Eoin Mcgillicuddy, Peter Croot, Pamela Bartley, John Mcmyler, Jerome Sheahan, Liam Morrison

Articles

Groundwater offers an important source for drinking water around the world; however, groundwater quality is under increasing pressure and is particularly vulnerable in karst areas. Total organic carbon (TOC) is significantly related to groundwater quality and when not removed by water treatment processes can give rise to the formation of disinfection by-products trihalomethanes (THMs) above the level of compliance. This study investigated the source of organic matter giving rise to the THM exceedances in a groundwater supply in a karst area. Results highlighted that source water for this groundwater supply was prone to surface water infiltration linked to rainfall events; …

A Geochemical Assessment Of Potential Groundwater Storage Locations Within The Yakima River Basin, Silas Sleeper

All Master's Theses

Currently in the Yakima River Basin more people possess surface water rights than there is available surface water. As a result, the local community devised the Yakima River Basin Integrated Water Management Plan, with the goal of creating a sustainable source of water for the foreseeable future. One of seven elements outlined in this plan is groundwater storage. The idea is to take available water during high spring flows and store it in the subsurface. The water will then be used to increase stream flows and decrease stream water temperatures during the summer months. A main challenge associated with groundwater …

Analysis Of A Large Spatiotemporal Groundwater Quality Dataset, Ontario 2010–2017: Informing Human Health Risk Assessment And Testing Guidance For Private Drinking Water Wells, Tessa Latchmore, Paul Hynds, R. Stephen Brown, Corinne Schuster-Wallace, Sarah Dickson-Anderson, Kevin Mcdermott, Anna Majury

Articles

Approximately 1.5 million individuals in Ontario are supplied by private water wells (private groundwater supplies). Unlike municipal supplies, private well water quality remains unregulated, with owners responsible for testing, treating, and maintaining their own water supplies. The primary goal of this study was to assess the effect of repeat sampling of private well water in Ontario and investigate the efficacy of geographically- and/or temporally specific testing recommendations and health risk assessments. The current study combines the Well Water Information System Dataset and the Well Water Testing Dataset from 2010 to 2017, inclusive. These two large existing province-wide datasets collated over …

A Geostatistical Study Of Socioeconomic Status (Ses), Rurality, Seasonality And Index Test Results As Drivers Of Free Private Groundwater Testing In Southern Ontario, 2012–2016, Shahryar Qayyum, Paul Hynds, Harriet Richardson, Kevin Mcdermott, Anna Majury

Articles

Approximately 12% of the Canadian population uses private wells for daily water consumption; however, well water testing rates are on the decline, resulting in an increased risk of waterborne acute gastrointestinal illness. To date, limited research has explored the determinants influencing well testing practices. Accordingly, the current study sought to investigate the drivers of “one-off” and repeat well water testing in southern Ontario during the 5-year period 2012–2016, using the worlds largest private groundwater testing data-frame. Data from >400,000 wells were geospatially integrated with all tests conducted by the provincial laboratory in southern Ontario. The Ontario Marginalization Index (ON-Marg) was …

Tidal-Groundwater Study Of The Slaughter Beach Salt Marsh In Slaughter Beach, De, Michael Powers

West Chester University Master’s Theses

Seasonal and decadal monitoring of salt marsh at Slaughter Beach, DE documented long-term and short-term variations in number and sizes of salt ponds. Over 400 salt ponds ranging in size between 0.5 m² to 0.11 km² were identified on 5.5 km² salt marsh platform. The purpose of this study is to quantify hydrologic conditions and measure groundwater discharge of a salt marsh, particularly the impact of tidal forces on groundwater fluctuation.

Four wells with nests of mini-piezometers with ONSET Pressure Transducers were installed along a transect crossing the largest salt pond (0.11 km²) in the …

Performance Study Of The Membrane Based Layered Double Hydroxides ‘Znal-Gh’ In The Purification Of Groundwater, Jaouad Zerhouni, Omar Qabaqous, Fouzia Rhazi Filali, Mohammed Naciri Bennani, Najib Tijani

Karbala International Journal of Modern Science

The objective of this work is focused on the preparation and characterization of plan microfiltration membrane Zn₃Al-Gh and the study of their efficiency in the treatment of ground water. This membrane was carried by using the support of the clay such as Ghassoul ‘Gh’ prepared by using dry uniaxial compaction method. The layered double hydroxides (LDH) based on Zn₃Al-CO₃with molar ratio (Zn²⁺/Al³⁺=3) was deposited on support by direct co-precipitation method.

The characterizations of the membrane LDH-Gh ‘Zn₃Al-Gh’ and deposited layer Zn₃Al-CO_3, was done by scanning …

The Spatial Distribution Of Elevated Uranium In The Treasure Valley Aquifer System, Southwest Idaho, Lloyd A. Womeldorph

Boise State University Theses and Dissertations

The Treasure Valley Aquifer System (TVAS) in southwestern Idaho contains well-documented uranium concentrations over the U.S. Environmental Protection Agency maximum contaminant level of 30 µg/L. With a population in the Treasure Valley projected to reach 1.6 million by 2065, in-depth horizontal and vertical spatial knowledge of the contaminant is needed. This study evaluates the horizontal and vertical spatial nature of uranium in the TVAS and interprets those observations to provide both a conceptual model of uranium behavior, and recommendations for water resource management. A large water quality dataset was compiled, and supplemented by data collected during a field sampling campaign, …