Physical Sciences and Mathematics Commons^™

Organic Fouling Mitigation In Forward Osmosis Technology Through The Use Of Oscilatting Alternating Current Electric Fields, Logan Werner

Graduate College Dissertations and Theses

Forward osmosis (FO) is the term given to osmosis in water filtration applications. FO has many advantages to conventional membrane filtration processes. The lack of external pressure needed to force solvent through the membrane is dramatically decreased in FO, resulting in a lower cost of operation compared to reverse osmosis. Lower external pressures also result in decreased fouling on the membrane surface and improved permeate flux. Fouling is one of the foremost challenges within the membrane filtration industry and is one of the biggest contributors to operating costs. While FO results in less fouling than RO, fouling remains a major …

Riparian Buffer Establishment Using Different Management Techniques, Stever H. Bartlett

Graduate College Dissertations and Theses

ABSTRACT

In riparian areas of the northeastern United States, well-established reed canary grass (Phalaris arundinacea) stands are common and have proven to be a challenge for the success of tree plantings during riparian forest restoration projects. The impacts of reed canary grass (RCG) on the habitats it invades are numerous. Reed canary grass reduces biological diversity by homogenizing habitat structure, richness, and environmental variability. Its rapid growth rate and invasive nature limits tree regeneration in riparian forests by shading and crowding out seedlings. Riparian forests improve water quality, wildlife habitat, flood control, and provide a variety of other ecosystem services. …

A Holistic Approach To River Restoration Design And Conservation Planning On The Reach And Basin Scales Using Hydraulic Modeling And Multi-Objective Optimization Tools, Lindsay Courtney Worley

Graduate College Dissertations and Theses

Flooding events around the world cost billions (USD) in damages each year. For decades, engineers have combated flood related damages by implementing flood mitigation controls such as channelization, levees or berms, and armoring. Recent advances in the study of river dynamics, however, have challenged the efficacy of these traditional flood mitigation techniques and pose that these structures are disconnecting channels from their floodplains, increasing flow rates, and contributing to more erosion. The effects of climate change combined with future predictions of increased storm frequency and intensity make it necessary to revise flood hazard mitigation strategies. A more nature-based alternative to …

An International Pilot Study Of Volunteer Stream Monitoring Groups: The Role Of Place Attachment In Volunteer Motivations, Rachel Pierson

Graduate College Dissertations and Theses

Engaging the public in scientific research through volunteer monitoring (a form of community science) has potential to expand knowledge of conditions and to improve collaborative decision-making. Many studies have sought to understand motivations for participation and potential resulting actions or behaviors that benefit the environment. Place-based connections have been demonstrated to lead people to adopt environmentally responsible behaviors. However, few studies have considered possible differences in motivations across countries or the role place attachment may play as a driver of initial or sustained participation.

The aim of this research was to determine the extent to which place attachment influences people’s …

Phosphorus And Nitrogen Losses In Runoff From Fields With And Without Tile Drainage, Leanna Thalmann

Graduate College Dissertations and Theses

Nutrient losses in surface and subsurface drainage from crop fields have important water quality implications. The deterioration of water quality in segments of Lake Champlain has led to efforts to reduce phosphorus (P) and nitrogen (N) export from agricultural fields. This thesis presents data from two years of edge-of-field monitoring in two adjacent corn (Zea mays L.) silage fields in Keeseville, New York. One field has only surface drainage improvements with monitoring equipment, and the other has both surface and subsurface drainage modifications and monitoring equipment. The study took place from October 2018 to September 2020 and quantified flow and …

Estimating Floodplain Storage And Prioritizing Floodplain Reconnection In The Northern Lake Champlain Basin In Vermont, Stephanie Drago

Graduate College Dissertations and Theses

Floodplains play a major role in maintaining the health and sustainability of riverine systems, but human interventions have reduced the connectivity between stream channels and floodplains. Geomorphic assessments of streams and rivers in Vermont (USA) show they have been significantly altered within the past two centuries due to straightening, berming, and armoring channels to accommodate development, agriculture, roads, and rail lines. These alterations in river-floodplain connectivity have decreased floodplain functioning, specifically their capacity to store water during flood events. Currently, there is a lack of knowledge concerning the amount of floodwater, sediment, and nutrient retention provided by Vermont’s floodplains. This …

Multiscale Assessment Of Drinking Water Treatment Residuals As A Phosphorus Sorbing Amendment In Stormwater Bioretention Systems, Michael Rick Ament

Graduate College Dissertations and Theses

Bioretention systems can reduce stormwater runoff volumes and filter pollutants. However, bioretention soil media can have limited capacity to retain phosphorus (P), and can even be a P source, necessitating P-sorbing amendments. Drinking water treatment residuals (DWTRs) have promise as a bioretention media amendment due to their high P sorption capacity. This research explores the potential for DWTRs to mitigate urban P loads using a combination of lab experiments, field trials, and an urban watershed model.

In the laboratory portion of this research, I investigated possible tradeoffs between P retention and hydraulic conductivity in DWTRs to inform bioretention media designs. …

After The Flood: Exploring The Influence Of Risk Perception And Decision Criteria Preference On Flood Mitigation In The Lake Champlain Richelieu River Basin, Emma Jane Spett

Graduate College Dissertations and Theses

In April of 2011, heavy rainfall paired with snow melt from the Green and Adirondack Mountains caused unprecedented flooding in the Lake Champlain Richelieu River (LCRR) basin. A study was subsequently convened by the International Joint Commission (IJC), and was tasked with identifying how flood forecasting, preparedness, and mitigation could be improved in order to reduce the impact of flooding in this transboundary watershed, and build the greater community’s resilience to flooding. A component of this study includes an assessment of the social acceptability and political feasibility of potential flood mitigation measures, which was in part carried out through the …

Assessing Chemical And Biological Recovery From Acid Rain Deposition In Montane Vermont Lakes, Sydney Diamond

Graduate College Dissertations and Theses

Vermont’s inland lakes are changing rapidly in response to anthropogenic disturbance pressures. While changes in water chemistry are well documented across the state, the biological response of primary producer communities to these shifts remains poorly understood. This project investigated the response of phytoplankton communities to the interacting effects of recovery from acidification and climate change in high-altitude lakes. We analyzed long-term monitoring and meteorological data in four of Vermont’s acid-impaired lakes and found that as pH and acid-neutralizing capacity has increased, so have concentrations of dissolved organic carbon (DOC) in most lakes. To assess the biological response to these processes, …

Growth Evaluation And Standardized Assessment Of Juvenile Lake Trout In Lake Champlain, Pascal Dylan Wilkins

Graduate College Dissertations and Theses

Restoration and recovery of lake trout (Salvelinus namaycush) has been the focus of research and management in the Great Lakes and Lake Champlain since populations collapsed in the late 19th and 20th centuries. Wild juvenile lake trout recruitment was discovered in Lake Champlain in 2015 after 42 years of stocking efforts. Intensive biweekly bottom trawl sampling during the ice-free season was conducted from 2015 to 2018 to assess the extent of wild recruitment at three different sampling areas (north, central, south) of the Main Lake. The collection of wild and stocked lake trout in bottom trawls enabled analysis and comparison …

Evaluation Of Nitrogen And Phosphorus Removal In Alternative Management Practices For Dairy Farm Production Area Runoff: Bioretention Cells And A Woodchip Bioreactor Treatment System, Jillian Sarazen

Graduate College Dissertations and Theses

Non-point source pollution from agricultural areas can lead to the degradation of downstream water bodies, including eutrophication and harmful algal blooms, due to high concentrations of nitrogen (N) and phosphorus (P) emanating from these areas. One source of agricultural runoff that is often overlooked, originates from agricultural production areas, which have impervious surfaces, such as paved and compacted areas, barnyards, cow paths, and silage bunker storage; these areas generate stormwater runoff and contribute to pollution during storm events.

This research evaluates two built stormwater runoff treatment systems designed to treat high concentrations of nutrients in runoff from a dairy farm. …

Governing Water Quality Limits In Agricultural Watersheds, Courtney Ryder Hammond Wagner

Graduate College Dissertations and Theses

The diffuse runoff of agricultural nutrients, also called agricultural nonpoint source pollution (NPS), is a widespread threat to freshwater resources. Despite decades of research into the processes of eutrophication and agricultural nutrient management, social, economic, and political barriers have slowed progress towards improving water quality. A critical challenge to managing agricultural NPS pollution is motivating landowners to act against their individual farm production incentives in response to distant ecological impacts. The complexity of governing the social-ecological system requires improved understanding of how policy shapes farmer behavior to improve the state of water quality. This dissertation contributes both theoretically and empirically …

Edge-Of-Field Hydrology And Nutrient Fluxes Within Northeastern Agroecosystems: Evaluation Of Alternative Management Practices And Water Quality Models, Cameron Robert Twombly

Graduate College Dissertations and Theses

Agricultural runoff is one of largest contributors of phosphorus (P), nitrogen (N), and sediment affecting freshwater systems in watersheds across the Northeastern U.S., including the Lake Champlain Basin in Vermont. Agricultural cropping systems, such as corn silage and haylands, used for dairy feed production have been shown to impact watershed hydrology and water quality. Agricultural best management practices (BMPs) have the potential to decrease runoff volumes and flow rates and the associated export of nutrients and sediment from agricultural fields. Many states in the Northeastern U.S., including Vermont, are beginning to require farmers to implement water quality BMPs and further …

Shining Light On The Storm: Using High-Frequency Optical Water Quality Sensors To Characterize And Interpret Storm Nutrient And Carbon Dynamics Among Contrasting Land Uses, Matthew Ch Vaughan

Graduate College Dissertations and Theses

Elevated nutrient concentrations present significant challenges to surface water quality management globally, and dissolved organic matter mediates several key biogeochemical processes. Storm events often dominate riverine loads of nitrate, phosphorus, and dissolved organic matter, and are expected to increase in frequency and intensity in many regions due to climate change. The recent development of in situ optical sensors has revolutionized water quality monitoring and has highlighted the important role storms play in water quality. This dissertation focuses on improving the application of in situ optical water quality sensors and interpreting the high-frequency data they produce to better understand biogeochemical and …

Nutrient Removal Performance Of A Wood Chip Bioreactor Treatment System Receiving Silage Bunker Runoff, Deborah Joy Kraft

Graduate College Dissertations and Theses

Silage bunker runoff is a form of agricultural pollution that contributes to aquatic ecosystem degradation. Current handling and treatment methods for this process wastewater are often ineffective or expensive. A woodchip bioreactor is an emerging treatment technology designed to facilitate denitrification through the provision of an anaerobic, carbon rich environment. A wood chip bioreactor treatment system, consisting of three pre-treatment tanks, two wood chip bioreactors, and one infiltration basin, was constructed at the Miller Research Complex in South Burlington, Vermont in 2016. Runoff and leachate from an adjacent silage storage bunker is directed into the system. The pre-treatment tanks include …

Bottom-Up Adaptive Management And Stakeholder Participation For Clean Water And Healthy Soils In A Complex Social-Ecological System, Sarah Coleman

Graduate College Dissertations and Theses

Protection of water resources in a changing climate depends on bottom-up stewardship and adaptive management. From the ground up, a vital component is maintaining soil ecosystem services that regulate water, recycle nutrients, sequester carbon, provide food, and other benefits. Interacting spatial, social, and physical factors determine agricultural and stormwater management, and their impact on water. This dissertation explores these dimensions within a complex social-ecological system. The first chapter evaluates a participatory process to elicit solutions to complex environmental problems across science, policy, and practice. The second chapter studies on-farm soil assessment and its role in informing management decisions and supporting …

Evaluating Alternative Technologies And Monitoring Methods For Water Quality In A Field Setting; Research On Effects On Phosphorous And Solids Removal From Cheese Factory Wash Water And Stormwater Runoff Treatment, Dana J. Allen

Graduate College Dissertations and Theses

Lake Champlain is a major economic driver for Vermont's tourism economy, as well as a primary source of drinking water for many of the state's residents but nutrient pollution represents a potential threat to ecosystem health and economic well-being. From December 2011 to December 2012 a field trial of an EAF steel slag filter was assessed for its feasibility in treating wastewater originating from Swan Valley Cheese (SVC), in Swanton, VT. The study focuses on a period of the filter's operation from May 4 to October 10, 2012. The plant generates approximately 20,000 gallons per day of high P concentration …

Evaluating Stormwater Pollutant Removal Mechanisms By Bioretention In The Context Of Climate Change, Amanda Cording

Graduate College Dissertations and Theses

Stormwater runoff is one of the leading causes of water quality impairment in the U.S. Bioretention systems are ecologically engineered to treat stormwater pollution and offer exciting opportunities to provide local climate change resiliency by reducing peak runoff rates, and retaining/detaining storm volumes, yet implementation is outpacing our understanding of the underlying physical, biological, and chemical mechanisms involved in pollutant removal. Further, we do not know how performance will be affected by increases in precipitation, which are projected to occur in the northeastern U.S. as a result of climate change, or if these systems could act as a source or …

Impacts Of Transportation Infrastructure On Stormwater And Surface Waters In Chittenden County, Vermont, Usa, Joseph Hollis Bartlett

Graduate College Dissertations and Theses

Transportation infrastructure is a major source of stormwater runoff that can alter hydrology and contribute significant loading of nutrients, sediment, and other pollutants to surface waters. These increased loads can contribute to impairment of streams in developed areas and ultimately to Lake Champlain. In this study we selected six watersheds that represent a range of road types (gravel and paved) and road densities (rural, suburban, and urban) present in Chittenden County, one of the most developed areas in Vermont. The location and density of road networks were characterized and quantified for each watershed using GIS analysis. Monitoring stations in each …

Measurement And Modeling Of Stormwater From Small Suburban Watersheds In Vermont, Joel Nipper

Graduate College Dissertations and Theses

Despite decades of U.S. water quality management efforts, over half of assessed waterbody units were threatened or impaired for designated uses in the most recent assessments, with urban runoff being a leading contributor to those impairments. This cumulative research explores several aspects of urban runoff dynamics through a combination of field study and modeling.

Stormwater ponds are ubiquitous in developed landscapes due to their ability to provide multiple forms of treatment for stormwater runoff. However, evolving design goals have reduced the applicability of much of the early work that was done on pond effectiveness. In this study, we instrumented a …

The Champlain Sea/Lake Champlain Transition Recorded In The Northeast Arm Of Lake Champlain, Usa-Canada, Ashliegh Theresa Belrose

Graduate College Dissertations and Theses

Sediment accumulated on a lakebed archives information about past climate and changes in the regional environment. Previous studies (Burgess, 2007; Koff, 2011; Palmer, 2012) in the Northeast Arm of Lake Champlain, specifically Missisquoi Bay and Saint Albans Bay, showed a period (~9,400 - 8,600 yBP) of elevated organic matter deposition in both bays, indicating a productive event that pre-dated any possible anthropogenic influence. However, the record was abruptly cut off and any documentation representing the span of time leading up to this event was not found. The elevated organic matter levels were explained as being the result of a warm, …

New Insights For The Future Of Lake Champlain: Practical Approaches And Useful Tools For Grappling With Uncertainty And Weighing Trade-Offs In Watershed Management., Philip Halteman

Graduate College Dissertations and Theses

The effective management of non-point source nutrient pollution continues to prove elusive. Though the scientific literature is unequivocal that all anthropogenic land uses contribute to non-point source (NPS) pollution, variable levels of contribution over time and across location and complex relationships between cost and effect make finding technologically effective management solutions difficult. In addition, these solutions are implemented in a world of scarce resources, diverse and often competing concerns and values, and intense public scrutiny. Clearly, making the best possible decision about how to manage NPS pollution under these conditions is not simple. My overarching goal was to develop and …

Master's Project: Evaluating The Effectiveness Of Best Management Practices On Rural Backroads Of Vermont: A Retrospective Assessment And Cost Analysis, Joanne S. Garton

Rubenstein School Masters Project Publications

Repeated erosion of over 7,000 miles of unpaved roads in Vermont is degrading water quality and draining limited town budgets. Best Management Practices (BMPs), including stone-lined ditches, turn outs, check dams, revetments, culverts and vegetative controls, are recommended by the Vermont Department of Transportation as low cost means of reducing the sediment and phosphorous run-off from backroads. However, their effectiveness, longevity and cost benefit are unknown. To address this gap, I assessed 100 BMPs at 43 erosion control projects constructed between 2005 and 2012 with funding from the Vermont Better Backroads program. BMP condition was compared to environmental factors that …