A total maximum daily load (TMDL) assessment in the Upper North Bosque River (UNBR) has mandated reductions of soluble reactive phosphorus (SRP). The large concentrations of dairies in the UNBR watershed have been identified as a source of the SRP. Agricultural best management practices (BMPs) can be used to reduce in-stream loads of manure nutrients from confined dairy feeding operations (CAFOs). A new BMP utilizes turfgrass sod to export composted dairy manure nutrients out of the impaired watershed in a sustainable manner. Previous plot-scale experiments have showed that 46 to 77% of applied phosphorus (P) and 36 to 47% of applied nitrogen (N) were removed in a single sod harvest. Two, 1.4 ha turfgrass fields were instrumented to measure runoff flow and sediment and nutrient transport. One turfgrass field was topdressed with composted dairy manure and fertilizer N and the other with fertilizer N only. A total of 3.5% of the applied manure P and 3.1% of applied manure N were lost in the surface runoff over a 1.5 year period. The runoff data from the experimental fields were used to calibrate and validate Soil and Water Assessment Tool (SWAT) model simulations of flow, sediment, organic, and mineral nutrients. The Nash-Sutcliffe model fit statistic was greater than 0.6 for flow, sediment, and nutrients during the calibration period and greater than 0.3 during the validation period. Research results indicated that turfgrass sod can be used to export composted dairy manure out of impaired watersheds to improve water and soil quality.

<p>Coastal eutrophication is a complex process that is caused largely by anthropogenic nutrient enrichment. Estuaries are particularly susceptible to nutrient impairment, owing to their intimate connection with the contributing watersheds. Estuaries experiencing accelerating eutrophication are subject to a loss of key ecological functions and services. This doctoral dissertation presents the development and implementation of an integrated approach toward assessing the water quality in the Neuse Estuary following the implementation of the total maximum daily load (TMDL) program in the Neuse River basin. In order to accomplish this task, I have developed a series of water quality models and modeling strategies that can be effectively used in assessing nutrient based eutrophication. Two watershed-level nutrient loading models that operate on a different temporal scale are developed and used to quantify nitrogen loading to the Neuse Estuary over time. The models are used to probabilistically assess the success of the adopted mitigation measures in achieving the 30 % load reduction goal stipulated by the TMDL. Additionally, a novel structure learning approach is adopted to develop a Bayesian Network (BN) model that describes chlorophyll dynamics in the Upper Neuse Estuary. The developed BN model is compared to pre-TMDL models to assess any changes in the role that nutrient loading and physical forcings play in modulating chlorophyll levels in that section of the estuary. Finally, a set of empirical models are developed to assess the water quality monitoring program in the estuary, while also exploring the possibility of incorporating remotely sensed satellite data in an effort to augment the existing in-situ monitoring programs.</p> / Dissertation

Concentrated animal feeding operations (CAFOs) have caused water quality concerns in many rural watersheds, sometimes forcing the State of Texas to conduct Total Maximum Daily Load (TMDL) assessments of stream nutrients such as nitrogen (N) and phosphorus (P). One suggested Best Management Practice (BMP) is the export of phosphorus (P) through turfgrass sod produced with composted dairy manure from an impaired rural watershed to an urban watershed. The manure-grown sod releases P slowly and would not require additional P fertilizer for up to 20 years in the receiving watershed. This would eliminate P application to the sod and improve the water quality of urban streams. The Soil and Water Assessment Tool (SWAT) was used to model a typical suburban watershed that would receive the transplanted sod. The objective of the modeling was to determine the water quality changes due to the import of sod transplanted from turf fields and grown with composted dairy manure. The SWAT model was calibrated to simulate historical flow and sediment and nutrient loading to Mary's Creek. The total P stream loading to Mary's Creek was lower when manure-grown sod was imported instead of commercial sod grown with inorganic fertilizers. Yet, flow, sediment yield, and total N yield increased equally for both cases at the watershed outlet. The SWAT simulations indicate that a turfgrass BMP can be used effectively to import manure P into an urban watershed and reduce in-stream P levels when compared to sod grown with inorganic fertilizers.

A total maximum daily load (TMDL) assessment in the Upper North Bosque River (UNBR) has mandated reductions of soluble reactive phosphorus (SRP). The large concentrations of dairies in the UNBR watershed have been identified as a source of the SRP. Agricultural best management practices (BMPs) can be used to reduce in-stream loads of manure nutrients from confined dairy feeding operations (CAFOs). A new BMP utilizes turfgrass sod to export composted dairy manure nutrients out of the impaired watershed in a sustainable manner. Previous plot-scale experiments have showed that 46 to 77% of applied phosphorus (P) and 36 to 47% of applied nitrogen (N) were removed in a single sod harvest. Two, 1.4 ha turfgrass fields were instrumented to measure runoff flow and sediment and nutrient transport. One turfgrass field was topdressed with composted dairy manure and fertilizer N and the other with fertilizer N only. A total of 3.5% of the applied manure P and 3.1% of applied manure N were lost in the surface runoff over a 1.5 year period. The runoff data from the experimental fields were used to calibrate and validate Soil and Water Assessment Tool (SWAT) model simulations of flow, sediment, organic, and mineral nutrients. The Nash-Sutcliffe model fit statistic was greater than 0.6 for flow, sediment, and nutrients during the calibration period and greater than 0.3 during the validation period. Research results indicated that turfgrass sod can be used to export composted dairy manure out of impaired watersheds to improve water and soil quality.

Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2004. / Title from first page of PDF document. Includes bibliographical references (p. 33).

The accurate prediction of water quality is essential for management of reservoirs used for drinking water supply. Since algae are a major source of taste and odor problems in drinking water, understanding and controlling algal growth and production is an important task. Deer Creek Reservoir supplies drinking water for over one million people in northern Utah and has been highly eutrophic in the past. Despite major reductions in external nutrient loading, including phosphorus, seasonal algal blooms in Deer Creek have not decreased to desired levels. Resuspension of sediment has been suggested as a potential source of internal nutrient loading for water bodies (including reservoirs in the Utah/Wyoming area) and may be responsible for delays in water quality improvement. I investigated sediment deposition and resuspension rates at the upper end of the reservoir and evaluated these sediments as a possible internal source of phosphorus. Sonar and GPS systems were used to make measurements of recently deposited sediment in the submerged Provo River delta of Deer Creek Reservoir during the period of May, June, July, and August 2011. ArcGIS 10 was used to interpolate survey points and calculate sediment volume changes, including areas of deposition and erosion. These data were used to develop approximate sedimentation rates for the soft sediment – which is most susceptible to resuspension during reservoir drawdown. I used previously measured field phosphorous concentrations in the sediment to estimate if these processes could affect reservoir phosphorous concentrations. The study used two survey areas, a small area near the Provo River inlet early in the year, and an extended larger area starting on June 23rd. I found that sediment volume in the smaller study area was increasing at a rate of 27-109 m3/day during the spring season. Data show that rates are slightly correlated with flow and reservoir elevation. Typically by August, Deer Creek reservoir would have been drawn down 2 to 4 m. However, due to a heavy snow pack in 2011, Deer Creek reservoir was not drawn down. When the reservoir is drawn down, the sediments in the upper region of the delta, where the survey was conducted, will be resuspended and deposited lower in the reservoir. These processes will likely result in releasing the phosphates currently bound to the sediment into the water column. Based on previous measurements of readily soluble phosphates bound to the sediment, this resuspension could release between 80 and 230 kg of phosphorus from the study area into the water column during critical times during the warm months–conditions well suited for algal growth. This amount of phosphorus, while an upper bound of what could be expected under actual field conditions, could raise phosphorus concentrations in the survey area by as much as 0.38 mg/L. The potential P (80-230 kg) release could account for 14%-42% of the TMDL. This is a potentially significant amount, especially if released during the critical late-summer period, and warrants more detailed study.

Municipal separate storm sewer system (MS4) permittees face costly obligations to reduce pollutant loadings needed to achieve waste load allocations (WLAs) and meet total maximum daily loads (TMDLs). Street sweeping is potentially an effective BMP since streets exist throughout urban watersheds, often are directly connected to the storm sewer, and are found to contain an abundance of contaminants. Although pollutant removal from street sweeping has been evaluated for decades, an understanding of the impact on water quality in receiving streams is elusive. Due to numerous variables, the large number of samples necessary to measure impact in receiving streams may never be obtained. In response, modeled pollutant removal efficiencies based on frequency of sweeping have been recommended to the Chesapeake Bay Program, but these results are suspect. Alternatively, the amount of swept material has emerged as a method to quantify reductions. A sampling study was conducted to measure pollutants in swept material. The study identified the fraction of material susceptible to transport in runoff based on timing of sweeping in relation to runoff events. Based on observed pollutant concentration associations with particle size, the study results in estimates of pollutant concentrations for the fraction of material susceptible to downstream transport, dependent on duration since the last rainfall and type of surface swept, whether the area is a streets or a parking lot. Pollutant loadings and required reductions to achieve the Chesapeake Bay WLAs for various land use sample areas are computed for an average year. Modeled removal efficiencies and results from the sampling study were employed to assess impacts from street sweeping. Modeled efficiencies predict significantly lower impact than measurements of pollutants susceptible to runoff in swept material. Modeled loadings are inconsistent with measurements of swept materials and the rigorous sweeping frequency required for modeled removal efficiency credit appears to be unnecessary. / Doctor of Philosophy / Many localities, state agencies and other public entities that own storm sewer systems are increasingly required to reduce pollutants discharged from their systems to surface waters as a result of programs stemming from the Clean Water Act. Traditional stormwater management practices, such as retention ponds, appear limited towards providing the total pollutant reductions necessary due to physical constraints, opportunity and cost. Street sweeping is potentially an effective alternative practice since streets exist throughout urban watersheds, often are directly connected to the storm sewer, are found to contain an abundance of contaminants and can be cost effective. Although pollutant removal from street sweeping has been evaluated for decades, an understanding of the pollutants removed from stormwater is elusive. Past studies suggest the large number of samples necessary to measure impact from sweeping in receiving streams may never be obtained. In response, pollutant removal estimates have been made using computer models, but modeled results are suspect since they cannot be calibrated. Alternatively, a measure of swept material has emerged as a method to quantify pollutant reductions. A sampling study was conducted to measure pollutants in swept material. Results identify the fraction of swept material washed from the swept surface dependent on timing of sweeping in relation to the duration since the last rainfall. Based on observed pollutant concentration associations with particle size, the study results in estimates of concentrations for the fraction of material susceptible to downstream transport, dependent on duration since the last rainfall and type of surface swept, whether the area is a streets or a parking lot. Application of the results are compared to modeled removal efficiencies towards achieving regulatory compliance within various land use sample areas. Modeled efficiencies predict significantly lower impact than measurements of pollutants susceptible to runoff in swept material. Rigorous sweeping frequency required for modeled removal efficiency credit appears to be unnecessary.

This dissertation presents three chapters of contemporary research in environmental and development economics. Each chapter echoes a common theme, in that achievement of regional goals constitute 'Wicked Problems' and that the approaches that parties may take to address these specific regional goals may have complex interactions with other regional goals. Decision-making, cost analysis, and multipurpose efficacy of the approaches that regional parties may take to achieve goals are evaluated in environmental and development contexts and implications for program analysis and policy design are discussed. The first chapter of this dissertation seeks to understand how regulated parties, i.e. Municipal Separate Storm Sewer Systems (MS4s), choose from the strategies at their disposal to achieve compliance with their Chesapeake Bay Total Maximum Daily Load (TMDL) obligations. To address declining Chesapeake Bay water quality, the United States Environmental Protection Agency (EPA) set extensive nutrient and sediment reduction goals under the 2010 Chesapeake Bay TMDL. Virginia has responded by passing along explicit nutrient and sediment reduction requirements to its MS4s, which can choose from a variety of urban stormwater, land use change, source control, and restoration practices to achieve reductions toward these requirements. MS4s in Virginia have also been granted flexibility to achieve reduction requirements through purchase of nutrient and sediment credits toward requirements through trade. In spite of the cost-savings that these credits provide, MS4s' interest in trading for these credits has been low. MS4s instead generally engage in onsite nutrient and sediment reduction themselves, in spite of the high costs of doing so. In response to low interest in trade, case analysis of MS4s' Bay TMDL compliance behavior and semi-structured interviews are conducted to better understand the role of trade in compliance strategy and the reasons for its non-use. Findings reveal that the Virginia MS4s studied typically choose to implement onsite urban stormwater practices, source control practices, and restoration practices in order to generate long-lasting local benefits, like erosion control, flood risk reduction, and progress toward local TMDL obligations, alongside reductions toward the Bay TMDL. MS4s refrain from term credit purchases out of concern over future availability and refrain from perpetual credit purchases because they have been able to use funding sources to achieve reductions from long-lasting onsite practices at similar per-pound costs, while also receiving local benefits. Implications are that supply-side efforts to support trade markets may not generate the level of activity expected, given that would-be buyers have generally limited interest in trade as a compliance strategy. The second chapter studies the degree to which the practices used to meet local TMDL water quality obligations contribute to Bay TMDL compliance for the Loudoun County MS4. Linear programming is used to estimate the minimal cost of achieving Bay compliance in addition to local obligations through representative nutrient and sediment reduction strategies. The model estimates that Loudoun County MS4 faces substantial costs just to meet local water quality goals ($11 million/yr). Since many of the actions taken to meet local water quality goals also generate pollutant reductions to the Chesapeake Bay, adding Bay TMDL obligations adds 0.2%, 3%, and 32.9% to these costs, depending on the water quality trading used to reach Bay TMDL compliance. Findings shed additional light on Chapter 1's goal of investigating the role of trade by explaining low interest in trade as stemming from heavy local water quality needs. Implications are that the burden imposed by the Bay TMDL may not be as high as generally thought. The third chapter shifts focus to the Opioid Crisis to evaluate the efficacy of Syringe Exchange Programs, best known for their efforts to prevent bloodborne illness transmission, at achieving their secondary intervention goal of preventing opioid overdose. While research has established that Syringe Exchange Programs, or SEPs, are effective at preventing bloodborne illness, little focus has been given to their ability to prevent fatal overdose, which they aim to do by engaging in intervention practices like naloxone and fentanyl test strip distribution. In response for need for understanding of Syringe Exchange Programming's impact on overdose, fixed effects analysis is used to empirically study the impact of county-level SEP in North Carolina following the state's 2016 SEP legalization. Need-based programming complicates analysis and likely biases findings of the impact of SEP on overdose upward. Regardless, findings consistently fail to find that SEP has a significant effect on fatal overdose from four categories of opioids, which should reduce concerns in recent literature that they may increase overdose death. Implications are that, since SEPs have a richly documented history of saving lives through the prevention of bloodborne illness and do not appear to increase overdose, contrary to findings in other work, policy makers should continue to incorporate SEP into their portfolio of strategies used to address the Opioid Crisis. / Doctor of Philosophy / This dissertation presents three chapters of contemporary research in environmental and development economics. Each chapter echoes a common theme, in that achievement of regional goals constitute 'Wicked Problems' and that the approaches that parties may take to address these specific regional goals may have complex interactions with other regional goals. Decision-making, cost analysis, and multipurpose efficacy of the approaches that regional parties may take to achieve goals are evaluated in environmental and development contexts and implications for program analysis and policy design are discussed. The first chapter of this dissertation seeks to understand how regulated parties, i.e. Municipal Separate Storm Sewer Systems (MS4s), choose from the strategies at their disposal to achieve compliance with their Chesapeake Bay Total Maximum Daily Load (TMDL) obligations. To address declining Chesapeake Bay water quality, the United States Environmental Protection Agency (EPA) set extensive nutrient and sediment reduction goals under the 2010 Chesapeake Bay TMDL. Virginia has responded by passing along explicit nutrient and sediment reduction requirements to its MS4s, which can choose from a variety of urban stormwater, land use change, source control, and restoration practices to achieve reductions toward these requirements. MS4s in Virginia have also been granted flexibility to achieve reduction requirements through purchase of nutrient and sediment credits toward requirements through trade. In spite of the cost-savings that these credits provide, MS4s' interest in trading for these credits has been low. MS4s instead generally engage in onsite nutrient and sediment reduction themselves, in spite of the high costs of doing so. In response to low interest in trade, case analysis of MS4s' Bay TMDL compliance behavior and semi-structured interviews are conducted to better understand the role of trade in compliance strategy and the reasons for its non-use. Findings reveal that the Virginia MS4s studied typically choose to implement onsite urban stormwater practices, source control practices, and restoration practices in order to generate long-lasting local benefits, like erosion control, flood risk reduction, and progress toward local TMDL obligations, alongside reductions toward the Bay TMDL. MS4s refrain from term credit purchases out of concern over future availability and refrain from perpetual credit purchases because they have been able to use funding sources to achieve reductions from long-lasting onsite practices at similar per-pound costs, while also receiving local benefits. Implications are that supply-side efforts to support trade markets may not generate the level of activity expected, given that would-be buyers have generally limited interest in trade as a compliance strategy. The second chapter studies the degree to which the practices used to meet local TMDL water quality obligations contribute to Bay TMDL compliance for the Loudoun County MS4. Linear programming is used to estimate the minimal cost of achieving Bay compliance in addition to local obligations through representative nutrient and sediment reduction strategies. The model estimates that Loudoun County MS4 faces substantial costs just to meet local water quality goals ($11 million/yr). Since many of the actions taken to meet local water quality goals also generate pollutant reductions to the Chesapeake Bay, adding Bay TMDL obligations adds 0.2%, 3%, and 32.9% to these costs, depending on the water quality trading used to reach Bay TMDL compliance. Findings shed additional light on Chapter 1's goal of investigating the role of trade by explaining low interest in trade as stemming from heavy local water quality needs. Implications are that the burden imposed by the Bay TMDL may not be as high as generally thought. The third chapter shifts focus to the Opioid Crisis to evaluate the efficacy of Syringe Exchange Programs, best known for their efforts to prevent bloodborne illness transmission, at achieving their secondary intervention goal of preventing opioid overdose. While research has established that Syringe Exchange Programs, or SEPs, are effective at preventing bloodborne illness, little focus has been given to their ability to prevent fatal overdose, which they aim to do by engaging in intervention practices like naloxone and fentanyl test strip distribution. In response for need for understanding of Syringe Exchange Programming's impact on overdose, fixed effects analysis is used to empirically study the impact of county-level SEP in North Carolina following the state's 2016 SEP legalization. Need-based programming complicates analysis and likely biases findings of the impact of SEP on overdose upward. Regardless, findings consistently fail to find that SEP has a significant effect on fatal overdose from four categories of opioids, which should reduce concerns in recent literature that they may increase overdose death. Implications are that, since SEPs have a richly documented history of saving lives through the prevention of bloodborne illness and do not appear to increase overdose, contrary to findings in other work, policy makers should continue to incorporate SEP into their portfolio of strategies used to address the Opioid Crisis.

In the development of the watershed, hydrodynamic, and water quality models for St. Louis Bay in Mississippi, the Better Assessment Science Integrating Point and Nonpoint Sources (BASINS 2.0) - Nonpoint Source Model (NPSM) was selected as the watershed model and the Environmental Fluid Dynamics Code (EFDC) which includes hydrodynamic and water quality models was selected as the Bay model. Watershed model calibration was initially accomplished utilizing historical data collected by the U.S. Geological Survey (USGS), U.S. Environmental Protection Agency (USEPA), Mississippi Department of Environmental Quality (MDEQ), and Gulf Coast Research Laboratory (GCRL). The watershed model simulated nonpoint source flow and pollutant loadings for all sub-watersheds, routed flow and water quality, and accounted for all major point source discharges in the St Louis Bay watershed. The model was executed for the period of time spanning from 1965 through 1999 in order to quantify flow and pollutant loadings under a variety of hydrologic conditions. Time varying output from the watershed model was applied directly to the St. Louis Bay model. The Bay model, in turn, simulated hydrodynamics and water quality, including water depth, velocities, salinity, temperature, and fecal coliforms. Final Bay model calibration was performed utilizing a set of site specific data acquired on St. Louis Bay during the period July 14-18, 1998. Model verification was conducted against another set of field data taken in the Bay, during April 18-27, 1999. Fecal coliform was modeled in each of the 750 segments of a three-dimensional system. Comparisons of the predicted and observed data are made qualitatively by using spatial and temporal comparisons. The response of model prediction calculations is consistent with trends of the observed data ranges. The applicability of the mathematical models is also demonstrated for the development of Total Maximum Daily Load (TMDL) for fecal coliform in the St. Louis Bay. The calibrated/verified model will be used as a planning tool to assess the water quality in the Watershed and the Bay as well as for calculating TMDL and Waste Load Allocation (WLA).

No description available.