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Matthew K. Landon - One of the best experts on this subject based on the ideXlab platform.
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groundwater quality of a Public Supply aquifer in proximity to oil development fruitvale oil field bakersfield california
Applied Geochemistry, 2019Co-Authors: Michael T Wright, Matthew K. Landon, Peter B. Mcmahon, Justin T KulongoskiAbstract:Abstract Due to concerns over the effects of oil production activities on groundwater quality in California, chemical, isotopic, dissolved gas and age-dating tracers were analyzed in samples collected from Public-Supply wells and produced-water sites in the Fruitvale oil field (FVOF). A combination of newly collected and historical data was used to determine whether oil formation fluids have mixed with groundwater used for Public Supply and what the potential pathways for the migration of oil formation fluids into groundwater may be. Stable isotopes of water (δ2H and δ18O) and age dating (3H, 3Hetrit, SF6 and 14C) tracers in groundwater samples were consistent with the Kern River being the main source of recharge to aquifers. The distribution of major ion concentrations and pH with distance from the Kern River indicate that natural processes were the primary controls on groundwater salinity. Two of 14 groundwater samples had δ13C-DIC values (−2.4 to +1.9 per mil) consistent with mixtures of
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Statistical Evaluation of Variables Affecting Occurrence of Hydrocarbons in Aquifers Used for Public Supply, California†
JAWRA Journal of the American Water Resources Association, 2013Co-Authors: Matthew K. Landon, Kenneth Belitz, Carmen A. Burton, Tracy A. Davis, Tyler D. JohnsonAbstract:The variables affecting the occurrence of hydrocarbons in aquifers used for Public Supply in California were assessed based on statistical evaluation of three large statewide datasets; gasoline oxygenates also were analyzed for comparison with hydrocarbons. Benzene is the most frequently detected (1.7%) compound among 17 hydrocarbons analyzed at generally low concentrations (median detected concentration 0.024 μg/l) in groundwater used for Public Supply in California; methyl tert-butyl ether (MTBE) is the most frequently detected (5.8%) compound among seven oxygenates analyzed (median detected concentration 0.1 μg/l). At aquifer depths used for Public Supply, hydrocarbons and MTBE rarely co-occur and are generally related to different variables; in shallower groundwater, co-occurrence is more frequent and there are similar relations to the density or proximity of potential sources. Benzene concentrations are most strongly correlated with reducing conditions, regardless of groundwater age and depth. Multiple lines of evidence indicate that benzene and other hydrocarbons detected in old, deep, and/or brackish groundwater result from geogenic sources of oil and gas. However, in recently recharged (since ~1950), generally shallower groundwater, higher concentrations and detection frequencies of benzene and hydrocarbons were associated with a greater proportion of commercial land use surrounding the well, likely reflecting effects of anthropogenic sources, particularly in combination with reducing conditions.
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Trends in concentrations of nitrate and total dissolved solids in Public Supply wells of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins, San Bernardino County, California: Influence of legacy land use
Science of The Total Environment, 2013Co-Authors: Robert Kent, Matthew K. LandonAbstract:Abstract Concentrations and temporal changes in concentrations of nitrate and total dissolved solids (TDS) in groundwater of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins of the Upper Santa Ana Valley Groundwater Basin were evaluated to identify trends and factors that may be affecting trends. One hundred, thirty-one Public-Supply wells were selected for analysis based on the availability of data spanning at least 11 years between the late 1980s and the 2000s. Forty-one of the 131 wells (31%) had a significant (p Increasing nitrate trends were associated with greater well depth, higher percentage of agricultural land use, and being closer to the distal end of the flow system. Decreasing nitrate trends were associated with the occurrence of volatile organic compounds (VOCs); VOC occurrence decreases with increasing depth. The relations of nitrate trends to depth, lateral position, and VOCs imply that increasing nitrate concentrations are associated with nitrate loading from historical agricultural land use and that more recent urban land use is generally associated with lower nitrate concentrations and greater VOC occurrence. Increasing TDS trends were associated with relatively greater current nitrate concentrations and relatively greater amounts of urban land. Decreasing TDS trends were associated with relatively greater amounts of natural land use. Trends in TDS concentrations were not related to depth, lateral position, or VOC occurrence, reflecting more complex factors affecting TDS than nitrate in the study area.
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Trends in concentrations of nitrate and total dissolved solids in Public Supply wells of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins, San Bernardino County, California: influence of legacy land use.
Science of The Total Environment, 2013Co-Authors: Robert Kent, Matthew K. LandonAbstract:Concentrations and temporal changes in concentrations of nitrate and total dissolved solids (TDS) in groundwater of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins of the Upper Santa Ana Valley Groundwater Basin were evaluated to identify trends and factors that may be affecting trends. One hundred, thirty-one Public-Supply wells were selected for analysis based on the availability of data spanning at least 11 years between the late 1980s and the 2000s. Forty-one of the 131 wells (31%) had a significant (p
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Geogenic sources of benzene in aquifers used for Public Supply, California
Environmental Science & Technology, 2012Co-Authors: Matthew K. Landon, Kenneth BelitzAbstract:Statistical evaluation of two large statewide data sets from the California State Water Board’s Groundwater Ambient Monitoring and Assessment Program (1973 wells) and the California Department of Public Health (12 417 wells) reveals that benzene occurs infrequently (1.7%) and at generally low concentrations (median detected concentration of 0.024 μg/L) in groundwater used for Public Supply in California. When detected, benzene is more often related to geogenic (45% of detections) than anthropogenic sources (27% of detections). Similar relations are evident for the sum of 17 hydrocarbons analyzed. Benzene occurs most frequently and at the highest concentrations in old, brackish, and reducing groundwater; the detection frequency was 13.0% in groundwater with tritium 1600 μS/cm, and anoxic conditions. This groundwater is typically deep (>180 m). Benzene occurs somewhat less frequently in recent, shallow, and reducing groundwater; the detection frequency was 2.6% in groundwater...
Christopher A Gellasch - One of the best experts on this subject based on the ideXlab platform.
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characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well wisconsin usa
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants.
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Characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well (Wisconsin, USA)
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:Con el objeto de proteger a los pozos de abastecimiento público de un amplio rango de contaminantes, es imperativo entender los mecanismos físicos de transporte y flujo en el sistema acuífero. Aunque el flujo a través de las fracturas ha sido típicamente asociado con rocas cristalinas o bien carbonáticas, hay una evidencia creciente que ello puede ser una importante componente de flujo en formaciones de areniscas relativamente permeables. El objetivo de este trabajo es determinar el rol que desempeñan las fracturas en el transporte de contaminantes en las proximidades de la superficie, tales como aguas residuales proveniente de las pérdidas de alcantarillas, a pozos de abastecimiento público en un acuífero de basamento profundo. Se estudió una parte del sistema acuífero cámbrico en Madison, Wisconsin (EEUU), usando una combinación de ensayos geofísicos, geoquímicos, e hidráulicos en una perforación adyacente a un pozo de abastecimiento público. Los datos sugieren que las fracturas del basamento son trayectorias importantes de transporte desde la superficie al acuífero profundo. Estos intervalos fracturados tienen valores de transmisividad de varios órdenes de magnitud más altos que los intervalos de rocas no fracturadas. Con respecto al transporte rápido de los contaminantes, altos valores transmisividad de las fracturas individuales hacen a ellas probablemente las mayores trayectorias de flujo preferencial. Los resultados sugieren que en un acuífero silicoclástico cercano a un pozo de abastecimiento público, las fracturas pueden tener un rol importante en el transporte de contaminantes provenientes de aguas residuales de las alcantarillas cloacas. In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants. Com o objetivo de proteger os furos de captação de abastecimento público de uma grande variedade de contaminantes, é imperativo compreender o fluxo físico e mecanismos de transporte no sistema aquífero. Embora o fluxo através de fraturas tenha sido associado tipicamente a rochas cristalinas ou a rochas carbonatadas, existe uma evidência crescente de que ele possa ser uma componente importante do fluxo em formações granulares relativamente permeáveis. O objetivo deste trabalho é determinar o papel que as fraturas assumem no transporte subsuperficial de contaminantes, tais como águas residuais provenientes da drenagem de esgotos para furos de abastecimento público que captam um aquífero rochoso profundo. Uma parte do sistema aquífero Câmbrico, em Madison, Wisconsin (EUA), foi estudada usando uma combinação de ensaios geofísicos, geoquímicos e hidráulicos num furo adjacente a uma captação de abastecimento público. Os dados sugerem que as fraturas no maciço são importantes vias de transporte a partir da superfície para o aquífero profundo. As zonas fraturadas têm valores de transmissividade várias ordens de magnitude mais elevados que as zonas não-fraturadas. Valores elevados de transmissividade em fraturas individuais torna-as nos caminhos preferenciais de fluxo em relação ao transporte rápido de contaminantes. Os resultados sugerem que, num aquífero siliciclástico perto de uma captação de abastecimento público, as fraturas podem ter um papel importante no transporte de contaminantes com origem no esgoto de águas residuais. 为防止公共供水井受到各种污染物污染,了解含水层系统中物理流动和运移机理是必要的。尽管裂隙中的流动代表性地与结晶岩或碳酸岩相联系,越来越多的证据表明它可以是相对可渗透的砂岩地层中流动的重要组成部分。本文旨在确定近地表污染物运移中裂隙所起的作用,比如从渗漏下水道到深层基岩含水层中的公共供水井的污水。利用地球物理、地球化学以及公共供水井附近钻孔液压测试相结合的手段对美国威斯康星州麦迪逊市部分寒武系含水层系统进行研究。数据表明基岩裂隙是从地表到深部含水层的重要运移路径。有裂隙的区间导水系数比无裂隙区间高若干个数量级。考虑到污染物的快速运移,个别裂隙的高导水系数使它们成为最可能优先运动路径。结果表明在靠近公共供水井的硅质碎屑含水层中,裂隙在下水道起源的污水污染物运移中起重要作用。 Afin de protéger des puits Publics d’alimentation contre une large gamme de polluants, il est impératif de comprendre le flux physique et les mécanismes de transport dans le système aquifère. Bien qu’un flux à travers des fractures ait été typiquement associé à des roches soit cristallines soit carbonatées, il y a une évidence grandissante qu’il peut être une composante importante de flux dans des formations gréseuses relativement perméables. L’objectif de ce travail est de déterminer le rôle que les fractures jouent dans le transfert de contaminants de sub-surface, tels que eaux usées d’égouts fuyants, à des puits d’alimentation dans un substrat aquifère profond. Une partie du système aquifère de Madispn, Wisconsin (USA) a été étudié en utilisant une combinaison de tests géophysique, géochimique et hydraulique dans un forage adjacent à un puits d’alimentation publique. Les données suggèrent que les fractures du substrat sont des chemins importants de passage depuis la surface à l’aquifère profond. Ces intervalles fracturées ont une transmissivité d’ordre de grandeur plusieurs fois supérieure à celle des intervalles non fracturés. En raison du transport rapide des contaminants, des valeurs de transmissivité élevées des fractures singulières en font les chemins préférentiels les plus vraisemblables. Les résultats suggèrent que dans un aquifère silicaté près d’un puits d’alimentation Public, des fractures peuvent avoir un rôle important dans le transport de contaminants d’eau résiduaire provenant d’égouts.
Jean M Bahr - One of the best experts on this subject based on the ideXlab platform.
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characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well wisconsin usa
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants.
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Characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well (Wisconsin, USA)
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:Con el objeto de proteger a los pozos de abastecimiento público de un amplio rango de contaminantes, es imperativo entender los mecanismos físicos de transporte y flujo en el sistema acuífero. Aunque el flujo a través de las fracturas ha sido típicamente asociado con rocas cristalinas o bien carbonáticas, hay una evidencia creciente que ello puede ser una importante componente de flujo en formaciones de areniscas relativamente permeables. El objetivo de este trabajo es determinar el rol que desempeñan las fracturas en el transporte de contaminantes en las proximidades de la superficie, tales como aguas residuales proveniente de las pérdidas de alcantarillas, a pozos de abastecimiento público en un acuífero de basamento profundo. Se estudió una parte del sistema acuífero cámbrico en Madison, Wisconsin (EEUU), usando una combinación de ensayos geofísicos, geoquímicos, e hidráulicos en una perforación adyacente a un pozo de abastecimiento público. Los datos sugieren que las fracturas del basamento son trayectorias importantes de transporte desde la superficie al acuífero profundo. Estos intervalos fracturados tienen valores de transmisividad de varios órdenes de magnitud más altos que los intervalos de rocas no fracturadas. Con respecto al transporte rápido de los contaminantes, altos valores transmisividad de las fracturas individuales hacen a ellas probablemente las mayores trayectorias de flujo preferencial. Los resultados sugieren que en un acuífero silicoclástico cercano a un pozo de abastecimiento público, las fracturas pueden tener un rol importante en el transporte de contaminantes provenientes de aguas residuales de las alcantarillas cloacas. In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants. Com o objetivo de proteger os furos de captação de abastecimento público de uma grande variedade de contaminantes, é imperativo compreender o fluxo físico e mecanismos de transporte no sistema aquífero. Embora o fluxo através de fraturas tenha sido associado tipicamente a rochas cristalinas ou a rochas carbonatadas, existe uma evidência crescente de que ele possa ser uma componente importante do fluxo em formações granulares relativamente permeáveis. O objetivo deste trabalho é determinar o papel que as fraturas assumem no transporte subsuperficial de contaminantes, tais como águas residuais provenientes da drenagem de esgotos para furos de abastecimento público que captam um aquífero rochoso profundo. Uma parte do sistema aquífero Câmbrico, em Madison, Wisconsin (EUA), foi estudada usando uma combinação de ensaios geofísicos, geoquímicos e hidráulicos num furo adjacente a uma captação de abastecimento público. Os dados sugerem que as fraturas no maciço são importantes vias de transporte a partir da superfície para o aquífero profundo. As zonas fraturadas têm valores de transmissividade várias ordens de magnitude mais elevados que as zonas não-fraturadas. Valores elevados de transmissividade em fraturas individuais torna-as nos caminhos preferenciais de fluxo em relação ao transporte rápido de contaminantes. Os resultados sugerem que, num aquífero siliciclástico perto de uma captação de abastecimento público, as fraturas podem ter um papel importante no transporte de contaminantes com origem no esgoto de águas residuais. 为防止公共供水井受到各种污染物污染,了解含水层系统中物理流动和运移机理是必要的。尽管裂隙中的流动代表性地与结晶岩或碳酸岩相联系,越来越多的证据表明它可以是相对可渗透的砂岩地层中流动的重要组成部分。本文旨在确定近地表污染物运移中裂隙所起的作用,比如从渗漏下水道到深层基岩含水层中的公共供水井的污水。利用地球物理、地球化学以及公共供水井附近钻孔液压测试相结合的手段对美国威斯康星州麦迪逊市部分寒武系含水层系统进行研究。数据表明基岩裂隙是从地表到深部含水层的重要运移路径。有裂隙的区间导水系数比无裂隙区间高若干个数量级。考虑到污染物的快速运移,个别裂隙的高导水系数使它们成为最可能优先运动路径。结果表明在靠近公共供水井的硅质碎屑含水层中,裂隙在下水道起源的污水污染物运移中起重要作用。 Afin de protéger des puits Publics d’alimentation contre une large gamme de polluants, il est impératif de comprendre le flux physique et les mécanismes de transport dans le système aquifère. Bien qu’un flux à travers des fractures ait été typiquement associé à des roches soit cristallines soit carbonatées, il y a une évidence grandissante qu’il peut être une composante importante de flux dans des formations gréseuses relativement perméables. L’objectif de ce travail est de déterminer le rôle que les fractures jouent dans le transfert de contaminants de sub-surface, tels que eaux usées d’égouts fuyants, à des puits d’alimentation dans un substrat aquifère profond. Une partie du système aquifère de Madispn, Wisconsin (USA) a été étudié en utilisant une combinaison de tests géophysique, géochimique et hydraulique dans un forage adjacent à un puits d’alimentation publique. Les données suggèrent que les fractures du substrat sont des chemins importants de passage depuis la surface à l’aquifère profond. Ces intervalles fracturées ont une transmissivité d’ordre de grandeur plusieurs fois supérieure à celle des intervalles non fracturés. En raison du transport rapide des contaminants, des valeurs de transmissivité élevées des fractures singulières en font les chemins préférentiels les plus vraisemblables. Les résultats suggèrent que dans un aquifère silicaté près d’un puits d’alimentation Public, des fractures peuvent avoir un rôle important dans le transport de contaminants d’eau résiduaire provenant d’égouts.
Kenneth R Bradbury - One of the best experts on this subject based on the ideXlab platform.
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characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well wisconsin usa
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants.
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Characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well (Wisconsin, USA)
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:Con el objeto de proteger a los pozos de abastecimiento público de un amplio rango de contaminantes, es imperativo entender los mecanismos físicos de transporte y flujo en el sistema acuífero. Aunque el flujo a través de las fracturas ha sido típicamente asociado con rocas cristalinas o bien carbonáticas, hay una evidencia creciente que ello puede ser una importante componente de flujo en formaciones de areniscas relativamente permeables. El objetivo de este trabajo es determinar el rol que desempeñan las fracturas en el transporte de contaminantes en las proximidades de la superficie, tales como aguas residuales proveniente de las pérdidas de alcantarillas, a pozos de abastecimiento público en un acuífero de basamento profundo. Se estudió una parte del sistema acuífero cámbrico en Madison, Wisconsin (EEUU), usando una combinación de ensayos geofísicos, geoquímicos, e hidráulicos en una perforación adyacente a un pozo de abastecimiento público. Los datos sugieren que las fracturas del basamento son trayectorias importantes de transporte desde la superficie al acuífero profundo. Estos intervalos fracturados tienen valores de transmisividad de varios órdenes de magnitud más altos que los intervalos de rocas no fracturadas. Con respecto al transporte rápido de los contaminantes, altos valores transmisividad de las fracturas individuales hacen a ellas probablemente las mayores trayectorias de flujo preferencial. Los resultados sugieren que en un acuífero silicoclástico cercano a un pozo de abastecimiento público, las fracturas pueden tener un rol importante en el transporte de contaminantes provenientes de aguas residuales de las alcantarillas cloacas. In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants. Com o objetivo de proteger os furos de captação de abastecimento público de uma grande variedade de contaminantes, é imperativo compreender o fluxo físico e mecanismos de transporte no sistema aquífero. Embora o fluxo através de fraturas tenha sido associado tipicamente a rochas cristalinas ou a rochas carbonatadas, existe uma evidência crescente de que ele possa ser uma componente importante do fluxo em formações granulares relativamente permeáveis. O objetivo deste trabalho é determinar o papel que as fraturas assumem no transporte subsuperficial de contaminantes, tais como águas residuais provenientes da drenagem de esgotos para furos de abastecimento público que captam um aquífero rochoso profundo. Uma parte do sistema aquífero Câmbrico, em Madison, Wisconsin (EUA), foi estudada usando uma combinação de ensaios geofísicos, geoquímicos e hidráulicos num furo adjacente a uma captação de abastecimento público. Os dados sugerem que as fraturas no maciço são importantes vias de transporte a partir da superfície para o aquífero profundo. As zonas fraturadas têm valores de transmissividade várias ordens de magnitude mais elevados que as zonas não-fraturadas. Valores elevados de transmissividade em fraturas individuais torna-as nos caminhos preferenciais de fluxo em relação ao transporte rápido de contaminantes. Os resultados sugerem que, num aquífero siliciclástico perto de uma captação de abastecimento público, as fraturas podem ter um papel importante no transporte de contaminantes com origem no esgoto de águas residuais. 为防止公共供水井受到各种污染物污染,了解含水层系统中物理流动和运移机理是必要的。尽管裂隙中的流动代表性地与结晶岩或碳酸岩相联系,越来越多的证据表明它可以是相对可渗透的砂岩地层中流动的重要组成部分。本文旨在确定近地表污染物运移中裂隙所起的作用,比如从渗漏下水道到深层基岩含水层中的公共供水井的污水。利用地球物理、地球化学以及公共供水井附近钻孔液压测试相结合的手段对美国威斯康星州麦迪逊市部分寒武系含水层系统进行研究。数据表明基岩裂隙是从地表到深部含水层的重要运移路径。有裂隙的区间导水系数比无裂隙区间高若干个数量级。考虑到污染物的快速运移,个别裂隙的高导水系数使它们成为最可能优先运动路径。结果表明在靠近公共供水井的硅质碎屑含水层中,裂隙在下水道起源的污水污染物运移中起重要作用。 Afin de protéger des puits Publics d’alimentation contre une large gamme de polluants, il est impératif de comprendre le flux physique et les mécanismes de transport dans le système aquifère. Bien qu’un flux à travers des fractures ait été typiquement associé à des roches soit cristallines soit carbonatées, il y a une évidence grandissante qu’il peut être une composante importante de flux dans des formations gréseuses relativement perméables. L’objectif de ce travail est de déterminer le rôle que les fractures jouent dans le transfert de contaminants de sub-surface, tels que eaux usées d’égouts fuyants, à des puits d’alimentation dans un substrat aquifère profond. Une partie du système aquifère de Madispn, Wisconsin (USA) a été étudié en utilisant une combinaison de tests géophysique, géochimique et hydraulique dans un forage adjacent à un puits d’alimentation publique. Les données suggèrent que les fractures du substrat sont des chemins importants de passage depuis la surface à l’aquifère profond. Ces intervalles fracturées ont une transmissivité d’ordre de grandeur plusieurs fois supérieure à celle des intervalles non fracturés. En raison du transport rapide des contaminants, des valeurs de transmissivité élevées des fractures singulières en font les chemins préférentiels les plus vraisemblables. Les résultats suggèrent que dans un aquifère silicaté près d’un puits d’alimentation Public, des fractures peuvent avoir un rôle important dans le transport de contaminants d’eau résiduaire provenant d’égouts.
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characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well wisconsin usa
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants.
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Characterization of fracture connectivity in a siliciclastic bedrock aquifer near a Public Supply well (Wisconsin, USA)
Hydrogeology Journal, 2013Co-Authors: Christopher A Gellasch, Kenneth R Bradbury, David J Hart, Jean M BahrAbstract:Con el objeto de proteger a los pozos de abastecimiento público de un amplio rango de contaminantes, es imperativo entender los mecanismos físicos de transporte y flujo en el sistema acuífero. Aunque el flujo a través de las fracturas ha sido típicamente asociado con rocas cristalinas o bien carbonáticas, hay una evidencia creciente que ello puede ser una importante componente de flujo en formaciones de areniscas relativamente permeables. El objetivo de este trabajo es determinar el rol que desempeñan las fracturas en el transporte de contaminantes en las proximidades de la superficie, tales como aguas residuales proveniente de las pérdidas de alcantarillas, a pozos de abastecimiento público en un acuífero de basamento profundo. Se estudió una parte del sistema acuífero cámbrico en Madison, Wisconsin (EEUU), usando una combinación de ensayos geofísicos, geoquímicos, e hidráulicos en una perforación adyacente a un pozo de abastecimiento público. Los datos sugieren que las fracturas del basamento son trayectorias importantes de transporte desde la superficie al acuífero profundo. Estos intervalos fracturados tienen valores de transmisividad de varios órdenes de magnitud más altos que los intervalos de rocas no fracturadas. Con respecto al transporte rápido de los contaminantes, altos valores transmisividad de las fracturas individuales hacen a ellas probablemente las mayores trayectorias de flujo preferencial. Los resultados sugieren que en un acuífero silicoclástico cercano a un pozo de abastecimiento público, las fracturas pueden tener un rol importante en el transporte de contaminantes provenientes de aguas residuales de las alcantarillas cloacas. In order to protect Public Supply wells from a wide range of contaminants, it is imperative to understand physical flow and transport mechanisms in the aquifer system. Although flow through fractures has typically been associated with either crystalline or carbonate rocks, there is growing evidence that it can be an important component of flow in relatively permeable sandstone formations. The objective of this work is to determine the role that fractures serve in the transport of near-surface contaminants such as wastewater from leaking sewers, to Public Supply wells in a deep bedrock aquifer. A part of the Cambrian aquifer system in Madison, Wisconsin (USA), was studied using a combination of geophysical, geochemical, and hydraulic testing in a borehole adjacent to a Public Supply well. Data suggest that bedrock fractures are important transport pathways from the surface to the deep aquifer. These fractured intervals have transmissivity values several orders of magnitude higher than non-fractured intervals. With respect to rapid transport of contaminants, high transmissivity values of individual fractures make them the most likely preferential flow pathways. Results suggest that in a siliciclastic aquifer near a Public Supply well, fractures may have an important role in the transport of sewer-derived wastewater contaminants. Com o objetivo de proteger os furos de captação de abastecimento público de uma grande variedade de contaminantes, é imperativo compreender o fluxo físico e mecanismos de transporte no sistema aquífero. Embora o fluxo através de fraturas tenha sido associado tipicamente a rochas cristalinas ou a rochas carbonatadas, existe uma evidência crescente de que ele possa ser uma componente importante do fluxo em formações granulares relativamente permeáveis. O objetivo deste trabalho é determinar o papel que as fraturas assumem no transporte subsuperficial de contaminantes, tais como águas residuais provenientes da drenagem de esgotos para furos de abastecimento público que captam um aquífero rochoso profundo. Uma parte do sistema aquífero Câmbrico, em Madison, Wisconsin (EUA), foi estudada usando uma combinação de ensaios geofísicos, geoquímicos e hidráulicos num furo adjacente a uma captação de abastecimento público. Os dados sugerem que as fraturas no maciço são importantes vias de transporte a partir da superfície para o aquífero profundo. As zonas fraturadas têm valores de transmissividade várias ordens de magnitude mais elevados que as zonas não-fraturadas. Valores elevados de transmissividade em fraturas individuais torna-as nos caminhos preferenciais de fluxo em relação ao transporte rápido de contaminantes. Os resultados sugerem que, num aquífero siliciclástico perto de uma captação de abastecimento público, as fraturas podem ter um papel importante no transporte de contaminantes com origem no esgoto de águas residuais. 为防止公共供水井受到各种污染物污染,了解含水层系统中物理流动和运移机理是必要的。尽管裂隙中的流动代表性地与结晶岩或碳酸岩相联系,越来越多的证据表明它可以是相对可渗透的砂岩地层中流动的重要组成部分。本文旨在确定近地表污染物运移中裂隙所起的作用,比如从渗漏下水道到深层基岩含水层中的公共供水井的污水。利用地球物理、地球化学以及公共供水井附近钻孔液压测试相结合的手段对美国威斯康星州麦迪逊市部分寒武系含水层系统进行研究。数据表明基岩裂隙是从地表到深部含水层的重要运移路径。有裂隙的区间导水系数比无裂隙区间高若干个数量级。考虑到污染物的快速运移,个别裂隙的高导水系数使它们成为最可能优先运动路径。结果表明在靠近公共供水井的硅质碎屑含水层中,裂隙在下水道起源的污水污染物运移中起重要作用。 Afin de protéger des puits Publics d’alimentation contre une large gamme de polluants, il est impératif de comprendre le flux physique et les mécanismes de transport dans le système aquifère. Bien qu’un flux à travers des fractures ait été typiquement associé à des roches soit cristallines soit carbonatées, il y a une évidence grandissante qu’il peut être une composante importante de flux dans des formations gréseuses relativement perméables. L’objectif de ce travail est de déterminer le rôle que les fractures jouent dans le transfert de contaminants de sub-surface, tels que eaux usées d’égouts fuyants, à des puits d’alimentation dans un substrat aquifère profond. Une partie du système aquifère de Madispn, Wisconsin (USA) a été étudié en utilisant une combinaison de tests géophysique, géochimique et hydraulique dans un forage adjacent à un puits d’alimentation publique. Les données suggèrent que les fractures du substrat sont des chemins importants de passage depuis la surface à l’aquifère profond. Ces intervalles fracturées ont une transmissivité d’ordre de grandeur plusieurs fois supérieure à celle des intervalles non fracturés. En raison du transport rapide des contaminants, des valeurs de transmissivité élevées des fractures singulières en font les chemins préférentiels les plus vraisemblables. Les résultats suggèrent que dans un aquifère silicaté près d’un puits d’alimentation Public, des fractures peuvent avoir un rôle important dans le transport de contaminants d’eau résiduaire provenant d’égouts.
