Browsing by Subject "TMDL"
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Item Open Access Achieving Better Outcomes in Local Government Stormwater Programs through Pay for Performance(2017-04-28) Alexandrovich, AndrewLocal governments are challenged with addressing stormwater pollution to meet water quality standards set forth by Total Maximum Daily Loads (TMDLs). Procurement and financial instruments used in traditional stormwater programs typically pay contractors based on delivery of a set of actions or volume of services (Pay for Success Learning Hub, no date). This oftentimes requires significant public staff time to design and administer projects, and places liability for performance risk and cost overruns on the local government. Additionally, green infrastructure has emerged as an attractive alternative to gray infrastructure solutions, however, its effectiveness is largely unproven. This combination of factors has piqued the interest of local governments around the country in cost-effective solutions that streamline agency staff time, and shift performance risk from the local government to the private sector. Four programs in the Chesapeake Bay region were analyzed in order to identify how alternative delivery models that incorporate pay for performance are being utilized in local government stormwater programs, and whether those approaches are likely to deliver better outcomes than traditional approaches. The analysis was carried out via a literature review and series of interviews with staff from each program and professionals with relevant expertise in this field of work. The structure, roles between the public and private sector partners, and degree to which pay for performance is applied varies across each program. The lessons learned from this analysis provide a strong foundation to build upon and inform adoption of pay for performance in local government stormwater programs. However, each program analyzed is in its early phases of implementation and this analysis does not address the cost-efficiency, in terms of environmental benefit per dollar spent, of each approach in satisfying TMDL requirements. Nonetheless, this analysis highlights a broad range of program examples, outlines the key components and benefits of each program and pay for performance, and highlights a set of enabling conditions necessary to establish an environment conducive to pay for performance.Item Open Access Assessing the effectiveness of the Neuse nitrogen TMDL program and its impacts on estuarine chlorophyll dynamics(2011) Alameddine, IbrahimCoastal 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.
Item Open Access Optimizing the scale of markets for water quality trading(Water Resources Research, 2014) Doyle, Martin W; Patterson, Lauren A; Chen, Yanyou; Schnier, Kurt E; Yates, Andrew JApplying market approaches to environmental regulations requires establishing a spatial scale for trading. Spatially large markets usually increase opportunities for abatement cost savings but increase the potential for pollution damages (hot spots), vice versa for spatially small markets. We develop a coupled hydrologic-economic modeling approach for application to point source emissions trading by a large number of sources and apply this approach to the wastewater treatment plants (WWTPs) within the watershed of the second largest estuary in the U.S. We consider two different administrative structures that govern the trade of emission permits: one-for-one trading (the number of permits required for each unit of emission is the same for every WWTP) and trading ratios (the number of permits required for each unit of emissions varies across WWTP). Results show that water quality regulators should allow trading to occur at the river basin scale as an appropriate first-step policy, as is being done in a limited number of cases via compliance associations. Larger spatial scales may be needed under conditions of increased abatement costs. The optimal scale of the market is generally the same regardless of whether one-for-one trading or trading ratios are employed.Item Open Access Pathogen Pollutant Loading Responses to Precipitation Dynamics and Land Cover(2008-04-25T15:33:48Z) O'Banion, RyanThe Newport River Estuary in Carteret County, North Carolina has been placed on the state’s 303D list for its inability to meet federally mandated surface water quality criteria. A pathogen pollutant Total Maximum Daily Load (TMDL) study with fecal coliform as an indicator species has therefore been undertaken by Kenneth H. Reckhow of Duke University. Integral to the completion of this TMDL is an understanding of the terrestrial pathogen pollutant loading responses to precipitation dynamics and land use within the Newport River Estuary. This masters project investigates pathogen pollutant loading by completing three primary objectives. Through visual analysis of sampled fecal coliform and flow data, the best available data are chosen for model fitting and creation. Geospatial analysis tools are then developed in Python and ArcGIS to accurately delineate coastal watersheds with Light Detection and Ranging (LIDAR) data. The data are then used to calibrate a model to predict fecal coliform loading responses to precipitation dynamics within the Newport River Estuary. The results of the three primary objectives illustrate the complicated relationship between fecal coliform loading and precipitation events. The geospatial analysis tools allow for the accurate delineation of coastal watersheds at scales previously unavailable to managers. Additionally, the calibrated model highlights problem areas for future modelers to address when attempting to quantify fecal coliform loading and precipitation dynamics.Item Open Access TMDLs for Bacterial Impairment of Shellfish Waters: An Analysis of Options for Coastal North Carolina(2008-04-25T17:41:55Z) Wallach, LauraIn North Carolina, more than 100,000 acres of shellfish waters have been closed to shellfishing, many since the Clean Water Act was put in place in 1972. These waters are considered impaired because of levels of fecal coliform bacteria in excess of a set water quality standard. By law, the state must develop a TMDL, or total maximum daily load, for each impaired water body. In North Carolina, only one TMDL for fecal coliform in shellfish waters has been developed in the State, and it has not been implemented. North Carolina does not offer any guidelines for implementing these TMDLs. The purpose of this project was to use case study TMDLs for nonpoint sources of fecal coliform in shellfish waters to see how they have been implemented and what North Carolina could learn from this. Land use was analyzed for coastal North Carolina counties, and the counties were categorized based on those land uses as forest, agriculture, or developed. Two case study TMDLs were selected for each category. After reading each case study, the TMDL contact for the state was interviewed about implementation of the case study and general guidelines for implementation in the state. Though some of these case studies were approved as early as 2004, none have been implemented. In addition, each state had different methods for dealing with TMDL implementation. Other means of improving water quality before TMDL development were also investigated. These included different types of best management practices, action by stakeholders, and watershed management plans. Any of these could be used to prevent water quality impairment or to improve degraded water quality. Actions can be taken on state and local levels to improve water quality in closed shellfish waters in North Carolina. Locally, sources of fecal coliform should be identified so appropriate best management practices can be selected and implemented. At the state level, requiring TMDL implementation with a specific timeline would increase the probability that water quality will improve as a result of the TMDL process.