Download or read book New Methods for Improving the Watershed Scale Modeling of In Stream Pathogen Indicator Bacteria written by Jeffrey J Iudicello and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Excessive bacteria levels are the leading cause of impairment in U.S. water bodies. This dissertation looked at the use of watershed-scale computer models to predict in-stream bacteria concentrations. The study site was the Little River Experimental Watershed (LREW) in Tifton, GA, and fecal coliform fate and transport models were built for four of the LREW catchments over the period Jan 1996 - Dec 2002. A multi-model approach was used in the study to examine the current capacity of industry-standard models and to avoid conclusions unique to a particular catchment. Three models were examined: HSPF, SWAT, and a new model based on the principles of hydrograph separation called the Characteristic Concentration (CC) model. Sensitive hydrology and water-quality parameters were identified in HSPF and SWAT and a response-surface iterative scheme was used to calibrate the sensitive parameters of the models, while a simpler calibration method was used for the 2-parameter CC model. Model performance, both hydrology and water-quality, was evaluated by the Nash-Sutcliffe statistic. The research was conducted in three substudies: an examination of the three models' performance in modeling bacteria concentrations in all four catchments, an examination in HSPF and SWAT to determine the relationship between model performance and the hydrologic state of the watershed, and an examination of model combination possibilities to further analyze model performance and provide methods for combining model output to maximize model results beyond what the individual models could achieve. The research revealed that while the hydrology components of HSPF and SWAT could be considered strong the water-quality components were not as strong. The model parameters describing in-stream bacteria processes were consistently more sensitive than parameters describing terrestrial processes of bacteria, a result that was reinforced when considering the hydrologic state of the watersheds. A Latin Hypercube analysis revealed that parameter uncertainty is significant in the models, but that structural uncertainty resulting from the model process equations is the dominant source of uncertainty in model predictions. The model combination methods were able to provide an improved set of model predictions and showed that in some cases the use of a single calibrated model may still not be the best representation of a watershed. In all cases the CC model performed comparably or better than HSPF and SWAT, and provided a new model framework for analyzing the environmental fate and transport of bacteria. The CC model is worth using in future modeling studies and may be particularly useful in model combination applications since it is comparatively much simpler to use and less data-intensive than either HSPF or SWAT.
Download or read book A Multi model Approach to Predicting Pathogen Indicator Bacteria Loading in Tmdl Analyses written by Donna-May G. Sakura-Lemessy and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation utilizes data from four sub-watersheds in the Little River Experimental Watershed, GA to develop models to improve forecast predictions related to the management of surface-water pollution due to non-point source runoff. Non-point source pollution is the primary cause of US surface-water quality impairment and a main transport mechanism for pathogens and other pollutants into receiving surface water bodies (US EPA 2008). In response to pollution reduction and watershed remediation mandates under the Federal Clean Water Act (1972)--particularly the Total Maximum Daily Load (TMDL) program--the role of water quality modeling in effectively rehabilitating impaired waters has taken on greater importance. Consequently, the significance of this study is that it is the first of its kind to incorporate a multi-model approach to address limitations in using single water quality models. In this regard, it builds on water quality engineering research by presenting methods to estimate contaminant concentrations and reduce uncertainty in overall model predictions in impaired water-bodies. Methodologically, the key point of departure in this dissertation is centered on the fact that water quality modeling is the cornerstone of TMDL analyses but the associated prediction uncertainty affects their adequacy in providing reliable contaminant loadings estimates in an impaired water body. As such, utilizing hydrological and water-quality process equations embedded in the two most widely used watershed-scale models, the Soil and Water Assessment Tool (SWAT) and Hydrological Simulation Program-Fortran (HSPF), and observed data from the sub-watersheds mentioned above, the dissertation addresses this limitation by combining results from the two competing models to reduce uncertainty and enhance accuracy of predictions. The study was conducted in two phases. First, HSPF and SWAT--two extensively-used, scientifically-rigorous, US EPA-approved watershed-scale codes--were used to build models of the four study catchments. The models were individually calibrated and shown (based on Nash-Sutcliffe Efficiency (NSE) ratios) to produce reliable simulations of the hydrologic and water quality conditions in the watershed. The second phase of the analysis involved using a multi-model approach to combine model forecasts. Model combination, introduced by Bates and Granger in 1969, has emerged as a viable analytical technique (Claesken and Hjort, 2008; Ajami et al., 2006) and widely-used across disciplines to improve model-forecasting results (Kim et al., 2006; Shamseldin et al., 1997; Granger, 2001; Clemens, 1989; Thompson, 1976; Newbold and Granger, 1974; Dickinson, 1973). After calibration, the model predictions were combined for each catchment using three different methods: the Weighted Average Method (WAM), the Nash-Sutcliffe Efficiency Maximization Method (NSE-max) and an Artificial Neural Network Method (ANN). Comparison of the results of the multi-model formulation with original individual model results showed improved estimates with all three combination methods. The improvement in model accuracy (based on NSE ratios) varied from modest to significant in both hydrologic and water quality variables. These improvements were attributed to a reduction in model structural uncertainty resulting from the ability to capture aspects of some of the more complex watershed interactions from exogenous information provided by the contributing models. It should be noted here, however, that as model availability increases, if additional models (beyond those utilized here) are used with this approach, care should be taken to ensure the credibility of each individual model for simulating the watershed scale processes under review. Limitations of this study include possible bias introduced by the use of deterministic models to estimate probabilistic contaminant distributions, limitations in available data, and the use of a seven-year study period that did not account for possible impacts of shorter periods of extreme hydrologic conditions on the individual model performances and model combination weightings. Recommendations for future research include (a) improving watershed-scale codes to better describe the probability distribution functions characteristic of contaminant distributions and data collection on wildlife species and populations; and investigating the fate and transport processes of pathogenic indicator bacteria deposited in forested areas and the impact of extreme hydrologic conditions on model performance and weighting. Overall, the findings from this dissertation suggest that water quality modeling incorporating a multi-model approach has the potential to significantly improve predictions compared to the predictions obtained when only one model is used. Clearly, the findings reported here have significant implications in improving TMDL analyses and remediation plans by presenting an approach that exploits the strengths of two of the most complete and well-accepted watershed-scale water quality models in the United States. Moreover, the findings of this dissertation auger well for the future of TMDL management in that it provides a more robust and cost effective basis for policy makers to decide on effective management strategies that incorporate acceptable risk, allowable loading and land use.
Download or read book Indicators for Waterborne Pathogens written by National Research Council and published by National Academies Press. This book was released on 2004-06-19 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent and forecasted advances in microbiology, molecular biology, and analytical chemistry have made it timely to reassess the current paradigm of relying predominantly or exclusively on traditional bacterial indicators for all types of waterborne pathogens. Nonetheless, indicator approaches will still be required for the foreseeable future because it is not practical or feasible to monitor for the complete spectrum of microorganisms that may occur in water, and many known pathogens are difficult to detect directly and reliably in water samples. This comprehensive report recommends the development and use of a "tool box" approach by the U.S Environmental Protection Agency and others for assessing microbial water quality in which available indicator organisms (and/or pathogens in some cases) and detection method(s) are matched to the requirements of a particular application. The report further recommends the use of a phased, three-level monitoring framework to support the selection of indicators and indicator approaches.Â
Download or read book Review of the New York City Watershed Protection Program written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2020-12-04 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: New York City's municipal water supply system provides about 1 billion gallons of drinking water a day to over 8.5 million people in New York City and about 1 million people living in nearby Westchester, Putnam, Ulster, and Orange counties. The combined water supply system includes 19 reservoirs and three controlled lakes with a total storage capacity of approximately 580 billion gallons. The city's Watershed Protection Program is intended to maintain and enhance the high quality of these surface water sources. Review of the New York City Watershed Protection Program assesses the efficacy and future of New York City's watershed management activities. The report identifies program areas that may require future change or action, including continued efforts to address turbidity and responding to changes in reservoir water quality as a result of climate change.
Download or read book Watershed Management for Potable Water Supply written by National Research Council and published by National Academies Press. This book was released on 2000-02-17 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1997, New York City adopted a mammoth watershed agreement to protect its drinking water and avoid filtration of its large upstate surface water supply. Shortly thereafter, the NRC began an analysis of the agreement's scientific validity. The resulting book finds New York City's watershed agreement to be a good template for proactive watershed management that, if properly implemented, will maintain high water quality. However, it cautions that the agreement is not a guarantee of permanent filtration avoidance because of changing regulations, uncertainties regarding pollution sources, advances in treatment technologies, and natural variations in watershed conditions. The book recommends that New York City place its highest priority on pathogenic microorganisms in the watershed and direct its resources toward improving methods for detecting pathogens, understanding pathogen transport and fate, and demonstrating that best management practices will remove pathogens. Other recommendations, which are broadly applicable to surface water supplies across the country, target buffer zones, stormwater management, water quality monitoring, and effluent trading.
Download or read book Microbial Source Tracking written by Jorge W. Santo Domingo and published by Emerging Issues in Food Safety. This book was released on 2007 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a state-of-the-art review of the current technology and applications being utilized to identify sources of fecal contamination in waterways. - Serves as a useful reference for researchers in the food industry, especially scientists investigating etiological agents responsible for food contamination. - Provides background information on MST methods and the assumptions and limitations associated with their use. - Covers a broad range of topics related to MST, including environmental monitoring, public health and national security, population biology, and microbial ecology. - Offers valuable insights into future research directions and technology developments.
Download or read book Protocol for Developing Pathogen TMDLs written by and published by . This book was released on 2001 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oceans and Human Health written by Patrick J. Walsh and published by Academic Press. This book was released on 2011-09-02 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oceans and Human Health highlights an unprecedented collaboration of environmental scientists, ecologists and physicians working together on this important new discipline, to the benefit of human health and ocean environmental integrity alike. Oceanography, toxicology, natural products chemistry, environmental microbiology, comparative animal physiology, epidemiology and public health are all long established areas of research in their own right and all contribute data and expertise to an integrated understanding of the ways in which ocean biology and chemistry affect human health for better or worse. This book introduces this topic to researchers and advanced students interested in this emerging field, enabling them to see how their research fits into the broader interactions between the aquatic environment and human health. Color illustrations of aquatic life and oceanic phenomena such as hurricanes and algal blooms Numerous case studies Socio-economic and Ethical Analyses place the science in a broader context Study questions for each chapter to assist students and instructors Risks and remedies sections to help define course modules for instruction
Download or read book Indicators for Waterborne Pathogens written by Committee on Indicators for Waterborne Pathogens and published by National Academies Press. This book was released on 2004-07-30 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent and forecasted advances in microbiology, molecular biology, and analytical chemistry have made it timely to reassess the current paradigm of relying predominantly or exclusively on traditional bacterial indicators for all types of waterborne pathogens. Nonetheless, indicator approaches will still be required for the foreseeable future because it is not practical or feasible to monitor for the complete spectrum of microorganisms that may occur in water, and many known pathogens are difficult to detect directly and reliably in water samples. This comprehensive report recommends the development and use of a “tool box” approach by the U.S Environmental Protection Agency and others for assessing microbial water quality in which available indicator organisms (and/or pathogens in some cases) and detection method(s) are matched to the requirements of a particular application. The report further recommends the use of a phased, three-level monitoring framework to support the selection of indicators and indicator approaches.
Download or read book Watershed Hydrology written by Vijay P. Singh and published by Allied Publishers. This book was released on 2003 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania written by National Research Council and published by National Academies Press. This book was released on 2005-04-04 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: The city of Pittsburgh and surrounding area of southwestern Pennsylvania face complex water quality problems, due in large part to aging wastewater infrastructures that cannot handle sewer overflows and stormwater runoff, especially during wet weather. Other problems such as acid mine drainage are a legacy of the region's past coal mining, heavy industry, and manufacturing economy. Currently, water planning and management in southwestern Pennsylvania is highly fragmented; federal and state governments, 11 counties, hundreds of municipalities, and other entities all play roles, but with little coordination or cooperation. The report finds that a comprehensive, watershed-based approach is needed to effectively meet water quality standards throughout the region in the most cost-effective manner. The report outlines both technical and institutional alternatives to consider in the development and implementation of such an approach.
Download or read book Nonpoint Source Transport Model for Indicator Bacteria from Western Rangeland Watersheds written by Everett P. Springer and published by . This book was released on 1982 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compendium of Tools for Watershed Assessment and Tmdl Development written by L. Shoemaker and published by . This book was released on 1997-11 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Broadens the review of models and techniques from solely watershed loading models to include receiving water models and ecological assess. techniques and models. It summarizes avail. techniques and models that assess and predict physical, chemical, and biol. conditions in waterbodies. Includes info. regarding: a wide range of watershed-scale loading models; field-scale loading models; receiving water models, including eutrophication/water quality models, toxics models, and hydrodynamic models; integrated modeling systems that, for example, link watershed-scale loading with receiving water processes; and ecological techniques and models that can be used to assess &/or predict the status of habitat, single species, or biol. community.
Download or read book Comprehensive Water Quality and Purification written by and published by Elsevier. This book was released on 2013-09-24 with total page 1537 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Water Quality and Purification, Four Volume Set provides a rich source of methods for analyzing water to assure its safety from natural and deliberate contaminants, including those that are added because of carelessness of human endeavors. Human development has great impact on water quality, and new contaminants are emerging every day. The issues of sampling for water analysis, regulatory considerations, and forensics in water quality and purity investigations are covered in detail. Microbial as well as chemical contaminations from inorganic compounds, radionuclides, volatile and semivolatile compounds, disinfectants, herbicides, and pharmaceuticals, including endocrine disruptors, are treated extensively. Researchers must be aware of all sources of contamination and know how to prescribe techniques for removing them from our water supply. Unlike other works published to date that concentrate on issues of water supply, water resource management, hydrology, and water use by industry, this work is more tightly focused on the monitoring and improvement of the quality of existing water supplies and the recovery of wastewater via new and standard separation techniques Using analytical chemistry methods, offers remediation advice on pollutants and contaminants in addition to providing the critical identification perspective The players in the global boom of water purification are numerous and varied. Having worked extensively in academia and industry, the Editor-in-Chief has been careful about constructing a work for a shared audience and cause
Download or read book Safe Management of Shellfish and Harvest Waters written by Gareth Rees and published by World Health Organization. This book was released on 2010 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Presents the contributions made, conclusions reached and the consensus statement agreed upon at a workshop on safe management of shellfish and harvest waters held 30 November - 2 December 2004 in Kuala Lumpur, Malaysia"--Pref.
Download or read book The Hyporheic Handbook written by Great Britain, Environment Agency Staff and published by . This book was released on 2009-11 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook brings together the latest research on a range of topics related to the groundwater-surface water interface and hyporheic zones specifically for environmental management practitioners.
Download or read book Riparian Areas written by National Research Council and published by National Academies Press. This book was released on 2002-10-10 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Clean Water Act (CWA) requires that wetlands be protected from degradation because of their important ecological functions including maintenance of high water quality and provision of fish and wildlife habitat. However, this protection generally does not encompass riparian areasâ€"the lands bordering rivers and lakesâ€"even though they often provide the same functions as wetlands. Growing recognition of the similarities in wetland and riparian area functioning and the differences in their legal protection led the NRC in 1999 to undertake a study of riparian areas, which has culminated in Riparian Areas: Functioning and Strategies for Management. The report is intended to heighten awareness of riparian areas commensurate with their ecological and societal values. The primary conclusion is that, because riparian areas perform a disproportionate number of biological and physical functions on a unit area basis, restoration of riparian functions along America's waterbodies should be a national goal.
