A new spatially telescoping approach was proposed to improve measurement flexibility and account for hydrologic scale in field studies of groundwater-surface water (GW-SW) interaction. We applied this spatially telescoping approach in a study GW-SW interactions along Lucile Creek, Alaska. Catchment-scale data were used to screen areas of potentially significant GW-SW exchange, indicating groundwater contribution from a deeper regional aquifer along the middle to lower reaches of the stream. This initial assessment was tested using reach-scale estimates of groundwater contribution during base flow conditions. The reach-scale measurements indicated a large increase in discharge along the middle reaches of the stream accompanied by a shift in chemical composition towards a regional groundwater end member. Point measurements of vertical water fluxes were used to evaluate spatial and temporal variability of GW-SW exchange within representative reaches. The spatially telescoping approach identified locations of GW-SW exchange and improved interpretation of reach-scale and point-scale measurements.

The Tangipahoa River and Natalbany River watersheds (Tangipahoa Parish/County) in the Lake Pontchartrain Basin (southeastern Louisiana) are experiencing rapid urbanization, particularly in the wake of the 2005 hurricane season. To document the impact of land use on water quality, thirty sites were monitored for surface water physiochemical, geochemical, and bacteriological parameters. Water quality data was compared to land use within four sub-watersheds of the Tangipahoa Watershed and three sub-watersheds of the Natalbany Watershed. Urbanization had the most profound impact on water quality of all land uses. In watersheds with little urban land cover (< 7% with the sub-watershed) waterbodies had low dissolved salt, nutrient, and fecal coliform concentrations and high dissolved oxygen levels. Waterbodies within the urban region (> 28% urban land cover within the sub-watershed) of the parish had significantly greater dissolved salt, nutrient, and fecal coliform concentrations and decreased dissolved oxygen concentrations. Specifically, nutrient and fecal coliform concentrations increased as streams flowed through urban areas. The specific conductance, fecal coliform counts, concentrations of sulfate, HCO3-C, sodium, and nutrients (NO3-N, NO2-N, NH4-N, and PO4-P), and the ratios of Na:Cl, Cl:Br, and SO4:Cl were shown to be the parameters most indicative of urban impacts. Many of the geochemical parameters correlated significantly with each other, particularly within the urban streams (the streams with the greatest concentrations). While fecal coliform counts were high within the urban streams, programs to address malfunctioning wastewater treatment plants (WWTP) appear to be working, with fecal coliform counts declining and dissolved oxygen levels rising during the course of the data collection. In contrast, sites undergoing rapid development showed an increase in turbidity levels and a decrease on dissolved oxygen levels (both going from healthy to unhealthy levels) during the 18-month course of the data collection. By understanding the impacts of urbanization on streams of the Gulf Coast, local and regional municipalities may be able to reduce the impacts in already urbanized areas or mitigate the impacts at the outset of development.

Os antimicrobianos, especialmente a classe das fluoroquinolonas (FQs), são utilizados em grandes quantidades na medicina humana e veterinária. Uma atenção especial deve ser dada à ocorrência desses fármacos em diferentes matrizes ambientais, devido a potencialidade de propagação da resistência bacteriana. As principais fontes dessa contaminação são os esgoto industrial, urbanos, esgoto sanitário de hospital e de fazendas que utilizam antibióticos com finalidades veterinárias. Após a ingestão, os antimicrobianos são excretados na sua forma inalterada e, devido a baixa eficiência dos sistemas convencionais de tratamento de esgoto, são eventualmente liberados para o meio aquático. Diferentes métodos têm sido desenvolvidos para a determinação de FQs em amostras aquosas diversas, tais como esgoto sanitário , água de abastecimento, águas superficiais e esgoto sanitário de hospital. A maior parte dessas amostras ambientais é complexa e exige uma série de etapas de preparo, limpeza e pré-concentração; de maneira que, nos últimos anos, extensos esforços têm sido feitos para o desenvolvimento de novas técnicas de preparo de amostra que reduzam o tempo, trabalho, consumo de solvente e que permitam melhor desempenho do processo analítico. Nesse estudo foram desenvolvidos dois métodos de extração - a extração em fase sólida (SPE ) e a microextração por sorvente empacotado (MEPS) - sendo a separação, identificação e quantificação feitos por HPLC-MS/MS. Os métodos foram avaliados e validados segundo os parâmetros: precisão, exatidão, recuperação, linearidade, limite de detecção (LD), limite de quantificação (LQ), seletividade, efeito matriz, eficiência total do processo e robustez. Posteriormente, foi feita aplicação dos métodos desenvolvidos para investigação de FQs em águas superficiais e amostra de esgoto coletadas em diferentes pontos da cidade de São Carlos-SP. Os métodos apresentaram valores de recuperação maiores que 80% para as FQs estudadas, e valores de exatidão e precisão menores que 30% . A comparação entre as técnicas de extração desenvolvidas permitiu listar vantagens e desvantagens particulares de cada técnica. Além do menor consumo de solventes e volume de amostras, valores insignificantes de efeito matriz foram alcançados para a técnica MEPS; no entanto a SPE, devido ao seu maior fator de concentração, permitiu a quantificação de duas fluoroquinolonas em amostra de esgoto doméstico e detecção das mesmas em amostra de rio. / Antimicrobials, particularly the fluoroquinolones (FQs) class, are widely used in human and veterinary medicine. Particular attention must be given to the occurrence of these drugs in different environmental matrices, due to the potential spread of bacterial resistance. Effluents from industries, residential districts, hospitals and animal farms are the main sources of contamination by antibiotics. After ingestion, the antimicrobials are excreted in its unchanged form. Due to the low efficiency of conventional wastewater treatments, these antimicrobials are eventually released into the aquatic environment. Several methods have been developed for the determination of FQs in different water samples, such as municipal wastewater, tap water, river water, and hospital sewage. Most of these environmental samples is complex and requires a number of preparation steps, cleaning and preconcentration. For this reason, recently, extensive efforts have been made to develop new techniques for sample preparation in order to reduce: time, number of steps, solvent consumption and achieve better performance on the analytical process. This work describes the development of two methods of extraction - by solid phase extraction (SPE) and microextraction by packed sorbent (MEPS) - and separation, identification and quantification by HPLC-MS/MS. These methods were evaluated and validated by studying the following parameters: accuracy, precision, recovery, linearity, limit of detection (MDL), limit of quantification (MQL), selectivity, matrix effect, process efficiency and robustness. These methods were subsequently applied for FQs investigation in surface water and sewage sample collected at different points in the city of Sao Carlos/SP, Brazil. The methods recoveries achieved values greater than 80% for the studied FQS and the accuracy and precision values were satisfactory when compared to the values acceptable by regulatory agencies such as EPA and AOAC. A comparison between the extraction techniques developed allowed listing advantages and disadvantages of each particular technique. Besides the lowest solvent consumption and volume of samples, negligible values of matrix effects were achieved for MEPS technique. However, SPE, due to its higher pre-concentration, allowed the quantification of two fluoroquinolones in a sample of sewage and the detection in river sample.

Os antimicrobianos, especialmente a classe das fluoroquinolonas (FQs), são utilizados em grandes quantidades na medicina humana e veterinária. Uma atenção especial deve ser dada à ocorrência desses fármacos em diferentes matrizes ambientais, devido a potencialidade de propagação da resistência bacteriana. As principais fontes dessa contaminação são os esgoto industrial, urbanos, esgoto sanitário de hospital e de fazendas que utilizam antibióticos com finalidades veterinárias. Após a ingestão, os antimicrobianos são excretados na sua forma inalterada e, devido a baixa eficiência dos sistemas convencionais de tratamento de esgoto, são eventualmente liberados para o meio aquático. Diferentes métodos têm sido desenvolvidos para a determinação de FQs em amostras aquosas diversas, tais como esgoto sanitário , água de abastecimento, águas superficiais e esgoto sanitário de hospital. A maior parte dessas amostras ambientais é complexa e exige uma série de etapas de preparo, limpeza e pré-concentração; de maneira que, nos últimos anos, extensos esforços têm sido feitos para o desenvolvimento de novas técnicas de preparo de amostra que reduzam o tempo, trabalho, consumo de solvente e que permitam melhor desempenho do processo analítico. Nesse estudo foram desenvolvidos dois métodos de extração - a extração em fase sólida (SPE ) e a microextração por sorvente empacotado (MEPS) - sendo a separação, identificação e quantificação feitos por HPLC-MS/MS. Os métodos foram avaliados e validados segundo os parâmetros: precisão, exatidão, recuperação, linearidade, limite de detecção (LD), limite de quantificação (LQ), seletividade, efeito matriz, eficiência total do processo e robustez. Posteriormente, foi feita aplicação dos métodos desenvolvidos para investigação de FQs em águas superficiais e amostra de esgoto coletadas em diferentes pontos da cidade de São Carlos-SP. Os métodos apresentaram valores de recuperação maiores que 80% para as FQs estudadas, e valores de exatidão e precisão menores que 30% . A comparação entre as técnicas de extração desenvolvidas permitiu listar vantagens e desvantagens particulares de cada técnica. Além do menor consumo de solventes e volume de amostras, valores insignificantes de efeito matriz foram alcançados para a técnica MEPS; no entanto a SPE, devido ao seu maior fator de concentração, permitiu a quantificação de duas fluoroquinolonas em amostra de esgoto doméstico e detecção das mesmas em amostra de rio. / Antimicrobials, particularly the fluoroquinolones (FQs) class, are widely used in human and veterinary medicine. Particular attention must be given to the occurrence of these drugs in different environmental matrices, due to the potential spread of bacterial resistance. Effluents from industries, residential districts, hospitals and animal farms are the main sources of contamination by antibiotics. After ingestion, the antimicrobials are excreted in its unchanged form. Due to the low efficiency of conventional wastewater treatments, these antimicrobials are eventually released into the aquatic environment. Several methods have been developed for the determination of FQs in different water samples, such as municipal wastewater, tap water, river water, and hospital sewage. Most of these environmental samples is complex and requires a number of preparation steps, cleaning and preconcentration. For this reason, recently, extensive efforts have been made to develop new techniques for sample preparation in order to reduce: time, number of steps, solvent consumption and achieve better performance on the analytical process. This work describes the development of two methods of extraction - by solid phase extraction (SPE) and microextraction by packed sorbent (MEPS) - and separation, identification and quantification by HPLC-MS/MS. These methods were evaluated and validated by studying the following parameters: accuracy, precision, recovery, linearity, limit of detection (MDL), limit of quantification (MQL), selectivity, matrix effect, process efficiency and robustness. These methods were subsequently applied for FQs investigation in surface water and sewage sample collected at different points in the city of Sao Carlos/SP, Brazil. The methods recoveries achieved values greater than 80% for the studied FQS and the accuracy and precision values were satisfactory when compared to the values acceptable by regulatory agencies such as EPA and AOAC. A comparison between the extraction techniques developed allowed listing advantages and disadvantages of each particular technique. Besides the lowest solvent consumption and volume of samples, negligible values of matrix effects were achieved for MEPS technique. However, SPE, due to its higher pre-concentration, allowed the quantification of two fluoroquinolones in a sample of sewage and the detection in river sample.

abstract: One of the two objectives of this dissertation is an investigation into the possible correlation between rainfall events and increased levels of E. coli and Mycobacterium using an existing data set. The literature states that levels of microbial concentrations do increase after rainfall events, but there are no studies to indicate this correlation applies in any Arizona water systems. The data analyzed for the bacterial concentrations project suggested the possibility of a correlation along one river but it is not conclusive to state that any correlation exists between rainfall events and the microbial concentration for many other sites included in the analysis. This is most likely due to the highly engineered water delivery systems that are not directly impacted. The secondary objective was to determine if there are environmental variables collected from an ongoing project which would be a good candidate for making predictions about any of the project data parameters. Of the 79 possible opportunities for the model to accurately predict the dependent variable, it showed strong statistical favorability as well as experimentally favorable results towards Dissolved Organic Carbon as the best dependent variable from the data set, resulting in an accuracy of 41%. This is relevant since Dissolved Organic Carbon is one of the most important water quality parameters of concern for drinking water treatment plants where disinfection by-products are a limiting factor. The need for further analysis and additional data collection is an obvious result from both studies. The use of hydrograph data instead of rainfall would be a logical new direction for the heavily engineered water delivery systems. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2018

The Atascadero Subbasin, located on the central coast of California, is a small, hydraulically separated sub-region of the Paso Robles Groundwater Basin. Three local cities operate approximately 40 wells to pump the Subbasin for their entire water supply needs. Past studies have questioned sustainability of the Subbasin as the combined pumping rate by the three cities is nearing the perennial yield of the Subbasin. The studies have been inconclusive as some areas of the Subbasin have seen increases in water table elevation thus questioning the assessment that consumption is nearing perennial yield. The objective of this research was to perform a water balance study for the aquifer and examine sustainability of the Subbasin. Surface water and groundwater models were developed to investigate the interaction between the Salinas River Alluvium Soils and the deeper Paso Robles Formation based on pumping from different shallow and deep wells. Surface water hydrology of the Subbasin was studied using HEC-HMS, and Visual MODFLOW was used to model the aquifer. Both HEC-HMS and Visual MODFLOW was calibrated to improve simulation accuracy. HEC-HMS was used to quantify natural recharge to the aquifer and to simulate streamflow and water level for the Salinas River. HEC-GeoHMS was used to delineate the watershed, create sub-watersheds and channel networks, and to extract sub-watershed inputs that were used to build HEC-HMS from geospatial data including land use, soil and topography data. Different hydrogeologic layers were defined to represent the alluvium and deeper soils. Results show that currently the Atascadero Subbasin does not appear to be in overdraft as shallow groundwater wells pump Salinas River underflow and the alluvium appears to be providing some recharge to the deeper aquifer. These findings would provide municipal and water managers better understanding of where their water comes from, the effects of their pumping, and could help with developing sustainable management strategies for the Subbasin.

Rapid population growth increases the competing water demand for agriculture and municipalities. This situation urges the necessity of using integrated water management to increase water supply and find possible symbiotic urban-agriculture relationships. Many studies have been done to simulate the integrated use of surface water, groundwater and reclaimed water for different water users. However, few studies use simulation/optimization (S-O) models for water resources to explicitly represent detailed interactions between the different resources as well as the relationship between users and resources. This research study uses an S-O model to show the symbiotic relationship between urban and agricultural water use. This model fully links the nonlinear flows of groundwater from multiple aquifer layers, surface waters, reclaimed water, and delayed returns of non-consumed water for municipal and agricultural uses. Using specific aquifer and stream properties, and related assumptions, the optimization result shows there is a symbiotic relationship between urban and agricultural water use. The unconsumed water returns to the hydrologic system, for both surface water and groundwater increase agricultural net return by 8.6 %, and urban population by 0.4%. This particular problem uses ModelMuse to create simulation input files, and SOMOS-Map to create the optimization input files to run the simulation/optimization problem in SOMOS. In addition to presenting an S-O model, we also provide practical information on how to create the model. The results of the study and the explanation on how to apply the method may be helpful information for engineers and water managers.

This thesis presents analysis of the hydrodynamic and sedimentation changes of the Causeway Lake, Queensland. It was created in 1939 when a causeway and bridge construction was built across the estuary entrance. Since the construction, significant sediment retention has occurred in the lake. The sediment study presented in this thesis was undertaken based on historical data, field data measurement and numerical modelling, supported by theoretical analysis. Based on bathymetry data for the period from 1986 and 2003, an average of 2500 m3/year of sediment has settled in the estuary. To verify the sources of sedimentation, field measurements were undertaken at selected sections at two upstream boundaries (Mulambin and Shoal Creeks), and at the downstream boundary under the bridge. Four sets of field measurements with tidal elevation up to 4.5 m (0.8 m above the bridge sill) were analysed. Results showed that sediment transport in from the sea side was about 1050 m3/year and from the catchments area was in the order of 1100 m3/year (wash load was not included). Implementation of numerical modelling using RMA required calibration using field data. The predicted sediment transport was in order of 2900 m3/year. The calibrated model was used to simulate the sedimentation pattern for the next 10 years. Four scenarios were analysed, and the resulting recommendation was to dredge out about 141,000 m3 sediment from the Mulambin Creek branch area. Other solutions were also suggested: improvement of lake management and possibility to raise the sill level (water gate).

In Addis Ababa, Ethiopia, open reservoirs provide the majority of the drinking water. In the study present and future condition of these water sources and supplies were systematically assessed regarding water quantities. The study was done by reviewing municipal documents and accessing meteorological, hydrological and demographical data in Addis Ababa. 0%, 5% and 10% change in reservoir inflow/rainfall were used and projections for 2020 and 2030 were used to estimate future temperature and population sizes. The result indicated that supplied water quantity per capita from surface sources in Addis Ababa is likely to be reduced. Both climate and socio-economic related vulnerabilities were identified and the four following got the highest risk score: Increases in population, increased per capita water demand, overexploited land and increased distribution losses.At present the annual increase in population in Ethiopia is 4.4% and annual GDP increase is 7%, leading to a growing water demand in Addis Ababa. If the water supplies are not substantially increased the situation will lead to water scarcity. By 2020 water demand coverage will be 34% and by 2030 22%, compared with the current 50% coverage.Overexploited land was also identified as a major vulnerability due to the impact on catchment hydrology and distribution losses, caused by insufficient maintenance and replacement of aged pipes. At present 20% of the treated water is lost and it is likely to increase during the coming decades. However, the climate change induced rainfall variability is unlikely to cause large problems within the observed timeframe. Even with a 100 year drought 14% of the available water would be spill due to the limited reservoir capacity.To secure future water distribution Addis Ababa Water and Sewerage Authority (AAWSA) should build dams north of the Entoto ridge. They should also gain further understanding about and find appropriate measures for, highlighted vulnerabilities. A full vulnerability assessment should be done by AAWSA and they should consider implementing a „Water Safety Plan‟ for the whole water supply system.

Conventional water treatment facilities are the norm for producing potable water for U.S. metropolitan areas. Rapidly-growing urban populations, competing demands for water, imperfect water markets, and uncertainty of future water supplies contribute to high interests in alternative sources of potable water for many U.S. municipalities. In situations where multiple supply alternatives exist, properly analyzing which alternative is the most-economically efficient over the course of its useful life requires a sound economic and financial analysis of each alternative using consistent methodology. This thesis discusses such methodology and provides an assessment of the life-cycle costs of conventional water treatment using actual data from an operating surface-water treatment facility located in McAllen, Texas: the McAllen Northwest facility. This facility has a maximum-designed operating capacity of 8.25 million gallons per day (mgd), but due to required shutdown time and other limitations, it is currently operating at 78% of the designed capacity (6.44 mgd). The economic and financial life-cycle costs associated with constructing and operating the McAllen Northwest facility are analyzed using a newly-developed Excel 2 spreadsheet model, CITY H O ECONOMICS . Although specific results are applicable only to the McAllen Northwest facility, the baseline results of $771.67/acre-foot (acft)/ yr {$2.37/1,000 gallons/yr} for this analysis provide insight regarding the life-cycle costs for conventional surface-water treatment. The baseline results are deterministic (i.e., noninclusive of risk/uncertainty about datainput values), but are expanded to include sensitivity analyses with respect to several critical factors including the facility’s useful life, water rights costs, initial construction costs, and annual operations and maintenance, chemical, and energy costs. For example, alternative costs for water rights associated with sourcing water for conventional treatment facilities are considered relative to the assumed baseline cost of $2,300/ac-ft, with results ranging from a low of $653.34/ac-ft/yr (when water rights are $2,000/ac-ft) to a high of $1,061.83/ac-ft/yr (when water rights are $2,600/ac-ft). Furthermore, modifications to key data-input parameters and results are included for a more consistent basis of comparison to enable comparisons across facilities and/or technologies. The modified results, which are considered appropriate to compare to other similarly calculated values, are $667.74/ac-ft/yr {2.05/1,000 gallons/yr}.