A área de estudo situada no município de Taboão da Serra, Região Metropolitana de São Paulo, possui histórico de ocorrências anômalas de chumbo na água subterrânea, frequentemente reportando concentrações acima dos valores orientadores da CETESB. Verifica-se que em muitos casos de contaminação ambiental por metais de forma geral, e principalmente o chumbo, os procedimentos realizados não são suficientes para que seja feita uma análise mais apurada da contaminação das águas subterrâneas, fazendo com que, em muitos casos a fonte da contaminação seja atribuída, erroneamente, ao material geológico. A presente dissertação teve como objetivo analisar a metodologia de investigação empregada pela empresa bem como avaliar o comportamento do chumbo na água subterrânea local quanto aos fatores geológicos e físico -químicos que produziram a sua ocorrência e presença na forma solúvel em meio aquoso. Dessa forma, para atender os objetivos acima, foram realizados estudos de caracterização hidrogeológica e hidroquímica. Os métodos hidrogeológicos foram realizados de forma a se obter dados básicos como, carga hidráulica, potenciometria, direção e velocidade da água no aquífero local. Os métodos hidroquímicos seguiram com a coleta de dados em campo como sondagem para coleta de solo, amostragem de águas subterrâneas, medidas de parâmetros físico-químicos e análises laboratoriais. Com relação aos dados dos parâmetros físico-químicos, o pH verificado para a área apresentou valores entre 5,43 a 9,7. A análise das concentrações históricas do íon chumbo no meio aquoso em relação ao diagrama de especiação, sugere que as formas mais estáveis do chumbo na faixa de pH encontrada corresponde, em porcentagem, as espécies: \'Pb POT.2+\' (20%) e \'Pb(OH) POT.+\' (20%). O restante, 60% pode ser identificado no diagrama Pb-S-C-O-H. Como a variação do pH nas campanhas de amostragem ficaram entre 6 e 9, e as condições de Eh positivas, a principal forma estável nesse contexto é o \'PbCO IND. 3\' . Entretanto, por conta do baixo carbono orgânico total COT em torno de 1%, o chumbo tende a se manter na matriz do solo ligado a fração argilosa em minerais como a caulinita, muscovita ou oxi-hidróxidos de ferro e alumínio presentes no solo segundo os resultados obtidos por Difração de Raio X. Dessa forma verifica-se que a avaliação da contaminação por chumbo pode estar relacionada com sua interação química com outros compostos no sistema aquífero. O que em termos das ações empresariais em caso ambiental sugere um levantamento mais amplo da investigação analisando a matri z do solo e as condições de solubilidade de seus principais constituintes. / The study area is located in the county of Taboão da Serra, São Paulo Metropolitan Region, has a history of anomalous occurrences of lead in groundwater, often reporting concentrations above the guideline values by CTESB. It is noted that in many cases of environmental contamination by metals, and especially lead, the procedures are not sufficient for a more accurate analysis of groundwater contamination is made, so that in many instances the source contamination is wrong attributed to the geological material. This thesis aims to analyze the research methodology employed by the company as well as evaluating the behavior of lead in local groundwater as the geological and physical- chemical factors that produced its occurrence and presence in soluble form in aqueous. Thus to meet the above objectives method of hydrogeological and hydrochemical characterization were performed. Hydrogeological methods were performed in order to obtain basic data as hydraulic load, potentiometry, direction and speed of the water at aquifer. The hydrochemical methods followed by collecting field data as probing for collecting soil, groundwater sampling, measures of physical-chemical parameters and laboratory analyses. According the data of physico-chemical parameters, pH checked for the area showed values between 5.43 to 9.7. The analysis of historical concentrations of lead ion in the aqueous in relation to the speciation diagram suggests that the most stable forms of lead in the pH range found corresponds in percentage species: \'Pb POT.2+\' (20%) and \'Pb (OH) POT.+\' (20%). The remaining 60% can be identified in the diagram Pb-S-C-O-H. As the pH variation in the sampling campaigns were between 6 and 9, and the conditions of positive Eh, the main stable in this context is \'PbCO IND.3\' . However, due to the low total organic carbon TOC around 1 %, lead tends to remain in the soil matrix bound to clay fraction minerals such as kaolinite, muscovite or oxy-hydroxides of iron and aluminum in the soil according to the results obtained by X-ray Diffraction. Thus it appears that the evaluation of lead contamination may be related to its chemical interaction with other compounds in the aquifer. In according of corporate actions in environmental cases suggests a broader survey of research analyzing the soil matrix and conditions of solubility of its main constituents.

Diversos métodos geofísicos têm sido empregados para a identificação de zonas fraturadas em rochas cristalinas a fim de locar pontos de perfuração de poços tubulares. Os métodos geoelétricos têm tido um papel importante na identificação destas zonas fraturadas, no entanto, em áreas urbanas sofrem com a falta de espaço e interferências diversas, o que limita suas aplicações. O presente trabalho visou correlacionar as anomalias geoelétricas típicas de zonas fraturadas em rochas cristalinas, com medidas de emanação natural de radônio a fim de estabelecer parâmetros que possam ser aplicados em áreas onde os fatores externos impeçam a execução dos métodos geoelétricos, uma vez que os fatores que interferem na aplicação desses métodos não interferem na emanação do radônio. Os resultados encontrados nas áreas investigadas mostraram uma boa correlação entre as anomalias geoelétricas e as anomalias de emanação de radônio, bem como foram boas as correlações com os resultados de vazão dos poços existentes nas áreas investigadas. A metodologia aqui proposta alcançou os objetivos podendo ser uma excelente ferramenta para prospecção de água subterrânea, tanto como método auxiliar, quanto como ferramenta principal de prospecção de aqüíferos em áreas onde outros métodos não possam ser aplicados devido a interferências diversas tais como: tubulações metálicas, fiações elétricas, entre outras. Estes tipos de interferências são bastante comuns em áreas urbanas, justamente onde a perfuração de poços é mais requerida. / A several geophysical methods have been used for the identification of shear zones in crystalline rocks in order to mark points to water well drilling. The geoelectrical methods have had an important role on the identification of these shear zones. However, in urban areas they suffer with the lack from space and diverse interferences, what it limits the application of these ones. The present research aimed to correlate the typical electrical anomalies of shear zones in crystalline rocks, with measures of natural emanation of radon, in order to establish parameters that can be applied in areas where the external factors hinder the execution of the geoelectrical methods, because the factors that intervene with the application of these methods do not intervene with the emanation of the radon. The results found in the investigated areas had shown a good correlation with the electrical anomalies and the radon emanation anomalies, as well as had been good the correlations with the results of yield of water wells on the investigated areas. The methodology proposal reached the objectives being able to be an excellent tool for groundwater prospection, as a auxiliary method auxiliary, as a main tool of prospection of fractured aquifers in areas where other methods cannot be applied due several interferences, as metallic pipes, electric wirings, and others. These types of interferences are sufficiently common in urban areas, exactly where the water well drilling its more necessary.

O objetivo principal deste trabalho é estimar a recarga direta e profunda do Sistema Aqüífero Guarani (SAG) na bacia representativa do Ribeirão da Onça. Paralelamente são analisados os comportamentos do aqüífero e da evapotranspiração na bacia. A bacia do Ribeirão da Onça apresenta características representativas típicas da região de afloramento do Sistema Aqüífero Guarani (SAG) no Estado de São Paulo. A bacia do Ribeirão da Onça tem a vantagem de ser uma bacia amplamente estudada em vários aspectos referentes à sua hidrologia e hidrogeologia. Obtiveram-se dados suficientes para fazer um balanço hídrico da bacia monitorada por um ano hidrológico e extrair uma estimativa da recarga direta e profunda nesta zona de afloramento do Sistema Aqüífero Guarani. Utilizaram-se dados da flutuação do nível do aqüífero para estimar a recarga direta e a variação do armazenamento subterrâneo. Os poços de monitoramento foram distribuídos em diversas culturas, possibilitando uma análise do comportamento do aqüífero por cultura. Estimou-se que a recarga direta do sistema, na bacia, está em torno de 400 mm anuais. A estimativa da recarga profunda indica um valor entre zero e 40 mm. A análise do comportamento do aqüífero mostra que a recarga direta é menor em solos cultivados com eucalipto e maior em áreas cultivadas com pastagem. A variação do nível do aqüífero apresenta forte correlação entre as culturas, exceto a de eucaliptos. A posição dos poços é fator fundamental para a estimativa da recarga direta. Terrenos mais planos tendem a produzir uma maior recarga direta do aqüífero. Avaliaram-se métodos de estimativa de evapotranspiração. A avaliação foi realizada entre alguns métodos empíricos e a evapotranspiração obtida através do balanço hídrico. Estimou-se uma evapotranspiração em torno de 900 mm anuais a partir do balanço hídrico. Todos os métodos empíricos e semi- empiríco, com exceção do de Thornthwaite, superestimaram a evapotranspiração quando comparados ao valor estimado pelo balanço hídrico. O método de Hargreaves-Samani foi o que mais se distanciou, com 1894 mm anuais. O método de Thornthwaite foi o que mais se aproximou, com 936 mm anuais, com discrepância de apenas entre 3% e -6% do valor estimado pelo balanço hídrico. A utilização dos métodos empíricos e semi- empíricos de estimativa da evapotranspiração, para estudos da recarga de aqüíferos na região da zona de afloramento do Sistema Aqüífero Guarani no estado de São Paulo, deve ser vista com cautela. Só uma avaliação prolongada poderá indicar quais os métodos mais se aproximam da realidade. Pelos resultados obtidos, recomenda-se a revisão das estimativas de disponibilidade hídrica sustentável do Sistema Aqüífero Guarani e a utilização com cautela dos métodos empíricos e semi-empíricos de estimativa da evapotranspiração, para estudos hidrológicos no estado de São Paulo. A análise do monitoramento da bacia do Ribeirão da Onça só vem a confirmar a representatividade dos estudos feitos nessa região e a grande relevância que esses estudos terão para o gerenciamento desse importante reservatório que é o Sistema Aqüífero Guarani / The main objective of this work is to esteem the recharge direct and deep in the Guarani Aquifer System (GAS) at the representative basin of Ribeirão da Onça. At the same time, the behavior and the evapotranspiration at the water basin have been studied. The Ribeirão da Onça water basin has typical representative characteristics on the outcrop region in the Guarani Aquifer System (GAS) in the São Paulo State. Its hydrology and hydrogeology have been widely studied under several aspects, what consists of an advantage. It had been gotten enough data to make a water balance of the monitored water basin for one hydrological year and get out the direct and deep recharge estimate at this outcrop region of the Guarani Aquifer System. It had been used data of the aquifer level fluctuation in order to estimate the direct recharge and the subterranean storage. The monitoring wells are distributed in several crops, making the behavior in the aquifer per crop analysis possible. The estimated direct recharge of the system, at the water basin, is about 400 mm. The estimated deep recharge is between zero and 40 mm. The aquifer behavior analysis shows that the direct recharge is smaller in soils with eucalyptus cultivated than it is in other crops. The wells position is also an important aspect to the direct recharge. Plainer and higher lands tend to produce a greater direct recharge of the aquifer. Evapotranspiration esteem methods had been also evaluated. The evaluation was made with some empirical methods and the evapotranspiration gotten through to the water balance. The evapotranspiration estimated through the water balance was about 900 mm per year. All the empirical and semi-empirical methods, excepting Thornthwaite, overestimated the evapotranspiration if compared to the water balance estimated value. The Hargreaves-Samani´s method was the most far-away, with 1894 mm per year. The Thornthwaite method was the closest, with 936 mm per year, only between -6% and 3% of the estimated value through the water balance. The use of empirical and semi-empirical methods to esteem the evapotranspiration, in order to study the aquifers recharge in the region of the outcrop zone of the Guarani Aquifer System at São Paulo State, must be used with caution. Only a long-term evaluation could say which methods get closer to the reality. Through the analysis of the gotten results, it is recommended a revision of the estimated sustained water accessibility of the Guarani Aquifer System and the cautious use of the empirical and semi- empirical methods to esteem the evapotranspiration, to hydrological studies at São Paulo State. The analysis of the monitoring of the Ribeirão da Onça water basin comes to prove the active role of the studies in this region and the importance that this studies will have to the management of this great reservoir that is the Guarani Aquifer System

Chemical and tritium analyses of groundwater, precipitation and discharge records, fracture orientations, lineaments, and structural, stratigraphic, and topographic relationships have been used to describe the groundwater systems of Mantua Valley, north-central Utah. Groundwater flows through fractured Paleozoic quartzites and carbonate rocks and discharges from eleven perennial springs in Mantua Valley. Permeability in quartzites is the result of intense faulting and jointing. Groundwater in carbonate aquifers flows through fractures and/or fractures modified by solution and discharges as relatively large springs (up to 227 liters per second). Neogene normal faulting, rather than extensive karst processes, has produced valleys which are closed or nearly closed to surface-water drainage. Groundwater in the area has relatively low total dissolved solids, is warmer than the mean annual air temperature, and is of the calcium-magnesium-bicarbonate type. Temperatures of the groundwater suggest circulation depths in excess of 10 to 185 meters. Intermittent turbidity and fluctuations in calcite and dolomite saturation indices and in groundwater temperatures suggest that springs may be supplied by mixtures of shallow and deeper groundwater flow. With the methods used here, a water budget analysis of the area indicates that recharge to the groundwater systems is approximately 49% of mean annual precipitation. Annual recharge and average discharge of the springs were used to calculate recharge areas, which range from 3.0 km2 to 18 km2. Tritium analyses of two of the springs suggest mean residence times of less than ten years.

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Thesis (M.S.)--University of Nevada, Reno, 2005. / "December 2005." Includes bibliographical references (leaves 69-72). Online version available on the World Wide Web.

As human population increases, demand for water supplies will cause an increase in pumping rates from confined aquifers which may become unconfined after long-term pumping. Such an unconfined-confined conversion problem has not been fully investigated before and is the focus of this thesis. The objective of this thesis is to use both analytical and numerical modeling to investigate groundwater flow in an unconfined-confined aquifer including the no-flow lateral boundary effect and the regional flow influence. This study has used Girinskii’s Potential in combination with MATLAB to depict how changes in aquifer dimensions, hydraulic properties, regional flow rates, and pumping rates affect the size and shape of the unconfined-confined boundary. This study finds that the unconfined-confined conversion is quite sensitive to the distance between the piezometric surface and the upper confining bed when that distance is small, and the sensitivity lessens as that distance increases. The study shows that pumping rate is the dominating factor for controlling the size of the unconfined-confined boundary in comparison to the regional flow. It also shows that the presence of a no-flow boundary alters the normally elliptical shape of the unconfined-confined boundary.

<p>Results from this study enables a better understanding of groundwater surface water interactions in the TMG, particularly regarding aquatic ecosystems. It has also highlighted the necessity to do proper impact assessments before proceeding with bulk abstraction from this important aquifer. The results also demonstrated the importance of differentiating between real groundwater and non-groundwater discharge contributions to surface hydrology and where these interface areas are located.</p>

The Mabou Group in the Picadilly region of New Brunswick consists predominantly of red siltstones with interbeds of sandstone and conglomerate. The Mabou is of importance in this region as it overlies evaporite deposits of economic value. Given that the Mabou is several hundred meters thick, yet possesses no significant marker beds, it has remained stratigraphically undifferentiated in the Picadilly region over the course of previous regional mapping efforts in the area. Given the lack of a stratigraphic framework, coupled with insufficient hydrogeological sampling and test data to delineate any laterally extensive flow zones, the hydro-stratigraphy of this sedimentary package has not been established. Based on experience gained at other operations, Potash Corporation of Saskatchewan Inc. (PCS) recognized the need to take a proactive approach towards understanding the hydrogeology of the Picadilly mine development site. PCS has used a specialized technique in characterizing boreholes to measure depth-profiles of hydrophysical properties by logging the electrical conductivity of the borehole fluids over a period of time. Through the interpretation of these logging results, with the context provided by conventional geophysical logging data and nearby exploration drill core, this research seeks to identify zones of flow and assess whether or not any major units with lateral connectivity can be identified. The results highlight four zones of interest within the Mabou: the Upper Mabou; vuggy porosity directly above gypsum-infilled fractures; vugs and fractures within the Medium Sandstone subdivision; and the lower Mabou Siltstone at the base of the Mabou Group (within ~15m of base). Three of these zones are of interest as they tend to have relatively high permeabilities, with permeabilities over 10 000 md measured within the Upper Mabou, as high as 1800 md in the vuggy porosity zone directly above gypsum-filled fractures and as high as 1900 md within the Medium Sandstone subdivision . The fourth zone, found at the base of the Mabou Group, is of interest because the modest to low permeability recorded (as high as 38 md) is higher than the surrounding rocks and is in close proximity to the caprock of future mining activity. The permeabilities of the rocks studied in this research are believed to be dominantly controlled by secondary porosity. In the case of the permeable zone identified above the zone of gypsum-infilled fractures, relatively high porosities (9 to 15%) were interpreted from geophysical logs. These elevated porosities are due to the presence of vuggy porosity in this zone. However, no clear correlation between log-derived porosity and permeability was observed for the other permeable zones. This is believed to be due to the fact that fractures were the dominant control on porosity in these zones, and that the incremental contribution of fracture porosity to total porosity was too small to be readily identified.

Over the last decade in North America, an increasing number of microbiological drinking water regulations have been used to manage groundwater resources that are potentially influenced by surface water. Regulations such as the Ontario Ministry of Environment Regulation 505, which requires at least a 60 day groundwater travel time between surface waters and drinking water wells, have been created with limited understanding of subsurface pathogen transport processes. Groundwater Under Direct Influence studies (GUDI or GWUDI in USA) are conducted to assess the need to treat well water at an extraction point. Currently, there is a lack of knowledge regarding factors that affect the transport of pathogens through porous media at the surface water-groundwater interface. Such information is required to supply sufficient quantities of drinking water in a cost effective and safe manner. <br /><br /> Factors that affect pathogen transport through porous media include: properties of the pathogen (i. e. surface charge, size, and morphology), properties of the granular media (i. e. mineralogy, size, texture, angularity) and properties of the water (i. e. pH, ionic strength and content, and natural organic matter). This study examines the effects of ionic strength, grain size and influent virus concentrations on pathogen transport in porous media. Fourteen column tests were conducted using the bacteriophage MS2 and 1. 5 µm microspheres; two commonly used non-pathogenic surrogates representative of human viruses and bacteria, respectively. Two size distributions of crushed silica sand, with median grain diameters of 0. 7 and 0. 34 mm, and two ionic strengths of 8 and 95 mmol/L were used. A 2² partial factorial design was used with a minimum of two replicates of each combination of the parameters. <br /><br /> The results show that complete breakthrough of both viruses and microspheres occurred in medium sand at low ionic strength. It was found that increasing ionic strength by Ca²⁺ addition precluded breakthrough of MS2 in both the medium and fine sands. This represents a greater than 8 log reduction in peak effluent concentration and essentially complete attenuation. <br /><br /> In fine sand, with low ionic strength water, a 5 log reduction in peak MS2 concentrations was observed. In the same sand at high ionic strength, no MS2 broke through the column, corresponding to a greater than 8 log removal. Since complete attenuation occurred in both grain sizes at high ionic strength, the effect of higher ionic strength in the fine sand was indistinguishable from the effect observed from raising the ionic strength in the medium sand. <br /><br /> In contrast to the viruses, microsphere transport was essentially unaffected by increasing ionic strength under the conditions investigated. A 1 log reduction in peak concentration was observed in the high ionic strength water in the medium sand. In spite of this, grain size had a profound effect on the attenuation of microspheres. There was no evidence of microsphere breakthrough in any of the fine sand columns at the low or high ionic strengths, yielding a greater than 5 log reduction in microsphere concentration associated with grain size alone. The effect of varying virus concentration was also investigated. It was found that varying the concentration of viruses between 10⁵ and 10⁷ pfu/ml had no discernable effect on their observed transport characteristics; normalised peak breakthrough concentration, percent attenuation and retardation relative to a bromide tracer. <br /><br /> Based on the results from this Thesis, in a riverbank filtration environment, there is reason to expect that, at comparable water qualities and in similar porous media, multiple logarithmic reductions of viruses and bacteria would occur over the much longer (than column length) flowpaths associated with RBF. There is also reason to expect this attenuation capability to vary based on riverbank grain size and water chemistry.