Hydrogeology Journal

, Volume 20, Issue 2, pp 263–282 | Cite as

Comparison of particle-tracking and lumped-parameter age-distribution models for evaluating vulnerability of production wells to contamination

  • S. M. Eberts
  • J. K. Böhlke
  • L. J. Kauffman
  • B. C. Jurgens
Paper

Abstract

Environmental age tracers have been used in various ways to help assess vulnerability of drinking-water production wells to contamination. The most appropriate approach will depend on the information that is available and that which is desired. To understand how the well will respond to changing nonpoint-source contaminant inputs at the water table, some representation of the distribution of groundwater ages in the well is needed. Such information for production wells is sparse and difficult to obtain, especially in areas lacking detailed field studies. In this study, age distributions derived from detailed groundwater-flow models with advective particle tracking were compared with those generated from lumped-parameter models to examine conditions in which estimates from simpler, less resource-intensive lumped-parameter models could be used in place of estimates from particle-tracking models. In each of four contrasting hydrogeologic settings in the USA, particle-tracking and lumped-parameter models yielded roughly similar age distributions and largely indistinguishable contaminant trends when based on similar conceptual models and calibrated to similar tracer data. Although model calibrations and predictions were variably affected by tracer limitations and conceptual ambiguities, results illustrated the importance of full age distributions, rather than apparent tracer ages or model mean ages, for trend analysis and forecasting.

Keywords

Groundwater age Contamination Numerical modeling Water supply USA 

Comparaison de modèles de traçage de particule et de modèles de distribution d’âge à paramétrage global pour l’évaluation de la vulnérabilité de puits productifs à la pollution

Résumé

Des traceurs environnementaux ont été utilisés de différentes façons pour aider à évaluer la vulnérabilité de puits de production d’eau potable à la pollution. L’approche la plus appropriée dépendra de l’information disponible et de celle qui est recherchée. Pour comprendre comment le puits répond à des sources de polluants non localisées et variables, il faut nécessairement une représentation de la distribution des âges de l’eau dans le puits. Une telle information sur des puits productifs est rare et difficile à obtenir, particulièrement dans les zones où manquent des études de terrain détaillées. Dans cette étude, des distributions d’âge déduites de modèles de flux souterrain détaillés avec suivi de particules advectives ont été comparés avec ceux générés par des modèles paramétriques globaux pour examiner les conditions dans lesquelles des estimations tirées de modèles plus simples, de modèles paramétrés moins liés à la ressource pourraient être utilisés à la place d’estimations issues de modèles de suivi de particule. Dans chacun des quatre sites hydrogéologiques contrastées aux USA, des modèles de suivi de particule et des modèles à paramétrage global basées sur des schémas conceptuels similaires et paramétrés pour des traçage similaires ont fourni en gros des distributions d’âge et des tendances de contamination largement semblables. Bien que les paramétrages de modèle et prévisions aient été affectés de façon variable par des limitations du traçage et par des ambiguités conceptuelles, les résultats ont illustré l’importance des distributions de l’âge total, comparativement aux âges apparents de traçage ou âges moyens du modèle, pour l’analyse de tendance et pour la prévision.

Comparación entre el seguimiento de una partícula y los modelos de parámetros concentrados de distribución de edad para evaluar la vulnerabilidad de los pozos de producción a la contaminación

Resumen

Los trazadores de edad ambiental han sido usados de varias maneras para ayudar a evaluar de vulnerabilidad de los pozos de producción de agua potable a la contaminación. El enfoque más apropiado depende de la información que está disponible y que la que es necesaria. Para entender como el pozo responde a la entrada variable de la fuente no puntual del contaminante en la capa freática se necesita alguna representación de la distribución de las edades de agua subterránea en el pozo. Tal información para los pozos de producción está dispersa y es difícil de obtener, especialmente en áreas carentes de un estudio detallado de campo. En este estudio se compararon las distribuciones de edades derivadas de modelos detallados de flujo de agua subterránea con el seguimiento advectivo de partículas para examinar las condiciones en las cuales las estimaciones a partir de modelos de parámetros concentrados más simples y menos intensivamente dependientes de los recursos podrían ser usados en lugar de la estimación de los modelos de seguimiento de partículas. En cada una de las cuatro configuraciones hidrogeológicas contrastantes en EEUU, el seguimiento de partículas y los modelos de parámetros concentrados brindaron a grandes rasgos las distribuciones de edad y las tendencias de contaminación resultan grandemente indistinguibles cuando estaban basadas en modelos conceptuales similares y calibrados con datos de similares trazadores. A pesar que las calibraciones del modelo y las predicciones estuvieron afectadas variablemente por las limitaciones de los trazadores y las ambigüedades conceptuales, los resultados ilustraron la importancia de las distribuciones de edad completa, más bien que las edades aparentes de trazadores o de modelos de edades medias, para los análisis de tendencias y predicciones.

生产井污染脆弱性评价的颗粒示踪及集中参数年龄分布模型的对比

摘要

用于评价饮用水生产井污染脆弱性的环境年龄示踪已被广泛应用。最适合的方法取决于可利用的信息及所需数据。为了解井对水面上非点源污染物输入变化的响应,必须知道地下水年龄的分布特征。生产井的这些信息较少,且难获得,尤其是在缺少详细野外调查的地区。本次研究,年龄分布来源于详细的地下水流动模型以及平流溶质运移,并与来源于集中参数模拟的年龄分布进行比较,以确定简单少源的加强集中参数模型估计值可用于替代颗粒示踪模型估计值的条件 。在美国的四个对比水文地质设置点,颗粒示踪及集中参数模拟法基于简单概念模型,对简单示踪数据进行验证,得出了大致的简单年龄分布及主要的难分辨的污染物趋势。尽管模型验证与预测受示踪物局限性及概念的不准确性的变化影响,结果表明对趋势分析及预测而言,完整的年龄分布比表观示踪年龄或模型平均年龄更有意义。

Comparação de modelos de rastreio de partículas e de parâmetros agregados de distribuição de idade para avaliação da vulnerabilidade à contaminação de poços de produção

Resumo

Traçadores ambientais de idade têm sido usados de várias maneiras para ajudar a avaliar a vulnerabilidade das captações de produção de água potável à contaminação. A abordagem mais adequada dependerá da informação que está disponível e do que é desejado. Para entender como o poço vai responder às variações das entradas de contaminantes difusos no nível freático, é necessária alguma representação da distribuição das idades das águas subterrâneas no poço. Estas informações são escassas e difíceis de obter para furos de produção, especialmente em áreas carentes de estudos de campo pormenorizados. Neste estudo, as distribuições de idade provenientes de modelos de fluxo de águas subterrâneas detalhados com rastreio de partículas advetivas foram comparadas com aqueles gerados a partir de modelos de parâmetros agregados, para examinar as condições em que as estimativas obtidas a partir de modelos mais simples, com menos recursos, poderiam ser usadas em vez das estimativas a partir de modelos de partículas de rastreio. Uma em cada quatro das configurações hidrogeológicas nos EUA, obtidas por modelos de partículas de rastreio e por modelos de parâmetros agregados, produziram distribuições de idade mais ou menos semelhantes e tendências de contaminação em grande parte indistinguíveis quando baseadas em modelos conceptuais semelhantes e calibrados para idênticos dados de traçadores. Embora a calibração e as previsões do modelo tenham sido afetadas de forma variável por limitações dos traçadores e por ambiguidades conceptuais, os resultados demonstraram a importância das distribuições de idade total, ao invés de modelos de idades aparentes de traçadores ou de modelos de média de idades, para análises de tendências e previsões.

Supplementary material

10040_2011_810_MOESM1_ESM.pdf (719 kb)
ESM 1(PDF 719 kb)

References

  1. Aeschbach-Hertig W, Peeters F, Beyerle U, Kipfer R (1999) Interpretation of dissolved atmospheric noble gases in natural waters. Water Resour Res 35:2779–2792CrossRefGoogle Scholar
  2. Aeschbach-Hertig W, Peeters F, Beyerle U, Kipfer R (2000) Palaeotemperature reconstruction from noble gases in ground water taking into account equilibration with entrapped air. Nat 405:1040–1044CrossRefGoogle Scholar
  3. Amin IE, Campana ME (1996) A general lumped parameter model for the interpretation of tracer data and transit time calculation in hydrologic systems. J Hydrol 179:1–21CrossRefGoogle Scholar
  4. Bayer R, Schlosser P, Banisch G, Rupp H, Zaucker F, Zimmek G (1989) Performance and blank components of a mass spectrometric system for routine measurement of helium isotopes and tritium by the 3He in-growth method. In: Sitzungsberichte der Heidelberger Akademie der Wissenschaften, Mathematisch-naturwissenschaftliche Klasse, 5. Springer, Heidelberg, Germany, pp 241–279Google Scholar
  5. Bethke CM, Johnson TM (2008) Groundwater age and groundwater age dating. Annu Rev Earth Planet Sci 36:121–152CrossRefGoogle Scholar
  6. Böhlke JK (2002) Groundwater recharge and agricultural contamination. Hydrogeol J 10:153–179, Erratum: (2002) Hydrogeol J 10:438–439CrossRefGoogle Scholar
  7. Böhlke JK (2006) TRACERMODEL1. Excel workbook for calculation and presentation of environmental tracer data for simple groundwater mixtures. In: Use of chlorofluorocarbons in hydrology, a guidebook, IAEA STI/PUB/1238. IAEA, Vienna, Austria, pp 239–243Google Scholar
  8. Brown CJ, Starn JJ, Stollenwerk KG, Mondazzi RA, Trombley TJ (2009) Aquifer chemistry and transport processes in the zone of contribution to a public-supply well in Woodbury, Connecticut, 2002–06. US Geol Surv Sci Invest Rep 2009–5051, 158 ppGoogle Scholar
  9. Burow KR, Jurgens BC, Kauffman LJ, Phillips SP, Dalgish BA, Shelton JL (2008) Simulations of groundwater flow and particle pathline analysis in the zone of contribution of a public-supply well in Modesto, eastern San Joaquin Valley, California. US Geol Surv Sci Invest Rep 2008–5035, 41 ppGoogle Scholar
  10. Busenberg E, Plummer LN (1992) Use of chlorofluoromethanes (CCl3F and CCl2F2) as hydrologic tracers and age-dating tools, Example: the alluvium and terrace system of Central Oklahoma. Water Resour Res 28(9):2257–2283CrossRefGoogle Scholar
  11. Busenberg E, Plummer LN, Bartholomay RC, and Wayland JE (1998) Chlorofluorocarbons, sulfur hexafluoride, and dissolved permanent gases in ground water from selected sites in and near the Idaho National Engineering and Environmental Laboratory, Idaho, 1994–97, US Geol Surv Open-File Rep 98–274, 72 ppGoogle Scholar
  12. Busenberg E, Plummer LN (2000) Dating young groundwater with sulfur hexafluoride, natural and anthropogenic sources of sulfur hexafluoride. Water Resour Res 36:3011–3030CrossRefGoogle Scholar
  13. Busenberg E, Plummer LN (2006) Potential use of other atmospheric gases. In: Use of chlorofluorocarbons in hydrology, a guidebook, IAEA STI/PUB/1238. IAEA, Vienna, Austria, pp 183–190Google Scholar
  14. Carle SF (1999) T-PROGS: Transition probability geostatistical software: user’s manual. University of California, Davis, CAGoogle Scholar
  15. Carle SF, LaBolle EM, Weissmann GS, VanBrocklin D, Fogg GF (1998) Geostatistical simulation of hydrostratigraphic architecture, a transition probability/Markov approach. In: Fraser GS, Davis JM (eds) Concepts in hydrogeology and environmental geology no. 1: hydrogeologic models of sedimentary aquifers. SEPM (Society for Sedimentary Geology), Tulsa, OKGoogle Scholar
  16. Chorco Alvarado JA, Purtschert R, Barbecot F, Chabault C, Rueedi J, Schneider V, Aeschbach-Hertig W, Kipfer R, Loosli HH (2007) Constraining the age distribution of highly mixed groundwater using 39Ar, a multiple environmental tracer (3H/3He, 85Kr, 39Ar, and 14 C) study in the semiconfined Fontainebleau Sands Aquifer (France). Water Resour Res. doi:10.1029/2006WR005096
  17. Clark WB, Jenkins WJ, Top Z (1976) Determination of tritium by mass spectrometric measurement of 3He. Int J Appl Radiat Isot 27:515–522CrossRefGoogle Scholar
  18. Clark BR, Landon MK, Kauffman LJ, Hornberger GZ (2007) Simulations of groundwater flow, transport, age, and particle tracking near York, Nebraska, for a study of transport of anthropogenic and natural contaminants (TANC) to public-supply wells. US Geol Surv Sci Invest Rep 2007–5068, 48 ppGoogle Scholar
  19. Cook PG, Böhlke JK (2000) Determining timescales for groundwater flow and solute transport. In: Cook PG, Herczeg AL (eds) Environmental tracers in subsurface hydrology. Kluwer, Boston, pp 1–30CrossRefGoogle Scholar
  20. Cook PG, Solomon DK (1995) Transport of atmospheric trace gases to the water table: Implications for groundwater dating with chlorofluorocarbons and krypton 85. Water Resour Res 31:263–270CrossRefGoogle Scholar
  21. Crandall CA, Kauffman LJ, Katz BG, Metz PA, McBride WS, Berndt MP (2009) Simulations of groundwater flow and particle tracking analysis in the area contributing recharge to a public-supply well near Tampa, Florida, 2002–05. US Geol Surv Sci Invest Rep 2008–5231, 53 ppGoogle Scholar
  22. Eberts SM, Erwin ML, Hamilton PA (2005) Assessing the vulnerability of public-supply wells to contamination from urban, agricultural, and natural sources. US Geol Surv Fact Sheet FS 2005–3022, 4 ppGoogle Scholar
  23. Einarson MD, Mackay DM (2001) Predicting impacts of ground water contamination. Environ Sci Technol 35:66A–73ACrossRefGoogle Scholar
  24. Frind EO, Molson JW, Rudolph DL (2006) Well vulnerability: a quantitative approach for source water protection. Ground Water 44:732–742Google Scholar
  25. Fylstra D, Lasdon L, Watson J, Waren A (1998) Design and use of the Microsoft Excel Solver. Interfaces 28:29–55CrossRefGoogle Scholar
  26. Goode DJ (1996) Direct simulation of groundwater age. Water Resour Res 32:289–296CrossRefGoogle Scholar
  27. Green CT, Böhlke JK, Bekins B, Phillips S (2010) Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer. Water Resour Res 46:1–19CrossRefGoogle Scholar
  28. Halford KJ, Hanson RT (2002) User guide for the drawdown-limited, multi-node well (MNW) package for the U.S. Geological Survey’s modular three-dimensional finite-difference groundwater flow model, versions MODFLOW-96 and MODFLOW-2000. US Geol Surv Open-File Rep 02–293, 33 ppGoogle Scholar
  29. Harbaugh AW, Banta ER, Hill MC, McDonald MG (2000) MODFLOW-2000, the U.S. Geological Survey modular ground-water model: user guide to modularization concepts and the ground-water flow process. US Geol Surv Open-File Rep 00–92, 121 ppGoogle Scholar
  30. Heaton THE, Vogel JC (1981) Excess air in groundwater. J Hydrol 50:201–216CrossRefGoogle Scholar
  31. Hill MC, Banta ER, Harbaugh AW, Anderman ER (2000) MODFLOW-2000, the U.S. Geological Survey modular ground-water model: user guide to the observation, sensitivity, and parameter-estimation processes and three post-processing programs. US Geol Surv Open-File Rep 00–184, 209 ppGoogle Scholar
  32. IAEA/WMO (2006) Global network of isotopes in precipitation, the GNIP Database. Available via http://isohis.iaea.org. Cited 27 Jan 2007
  33. Jurgens BC, Burow KR, Dalgish BA, Shelton JL (2008) Hydrogeology, water chemistry, and factors affecting the transport of contaminants in the zone of contribution of a public-supply well in Modesto, eastern San Joaquin Valley, California. US Geol Surv Sci Invest Rep 20085156, 78 ppGoogle Scholar
  34. Katz BG, Crandall CA, Metz PA, McBride WS, Berndt MP (2007) Chemical characteristics, water sources and pathways, and age distribution of ground water in the contributing recharge area of a public-supply well near Tampa, Florida, 2002–05. US Geol Surv Sci Invest Rep 2007–5139, 85 ppGoogle Scholar
  35. Kauffman LJ, Baehr, AL, Ayers, MA, Stackelberg, PE (2001) Effects of land use and travel time on the distribution of nitrate in the Kirkwood-Cohansey aquifer system in southern New Jersey. US Geol Surv Sci Invest Rep 01–4117, 49 ppGoogle Scholar
  36. Konikow LF, Hornberger GZ (2006) Use of the multi-node well (MNW) package when simulating solute transport with the MODFLOW ground-water transport process. US Geol Surv Tech Methods 6-A15, 34 ppGoogle Scholar
  37. Konikow LF, Goode DJ, Hornberger GZ (1996) A three-dimensional method-of- characteristics solute-transport model (MOC3D). US Geol Surv Water Resour Invest Rep 96–4267, 87 ppGoogle Scholar
  38. Koterba MT, Wilde FD, Lapham WW (1995) Ground-water data-collection protocols and procedures for the National Water-Quality Assessment Program: collection and documentation of water-quality samples and related data. US Geol Surv Open-File Rep 95–399, 113 ppGoogle Scholar
  39. Landon MK, Eberts SM, Jurgens BC, Katz BG, Burow KR, Crandall CA, Brown CJ, Starn JJ (2006) Knowledge of where and how contamination-susceptible water enters public-supply wells can be used to improve monitoring strategies and protection plans. Ground Water Protection Council Annual Forum. GWPC, Miami Beach, FLGoogle Scholar
  40. Landon MK, Clark BR, McMahon PB, McGuire VL, Turco MJ (2008) Hydrogeology, chemical-characteristics, and water sources and pathways in the zone of contribution of a public-supply well in York, Nebraska. US Geol Surv Water Resour Invest Rep 2008–5050, 149 ppGoogle Scholar
  41. Levenspiel O (1999) Chemical Reaction Engineering, 3rd edn. Wiley, New YorkGoogle Scholar
  42. Maloszewski P, Zuber A (1982) Determining the turnover time of groundwater systems with the aid of environmental tracers: 1, models and their applicability. J Hydrol 57:207–231CrossRefGoogle Scholar
  43. Maloszewski P, Zuber A (1993) Principals and practice of calibration and validation of mathematical models for the interpretation of environmental tracer data in aquifers. Adv Water Res 16:173–190CrossRefGoogle Scholar
  44. Małoszewski P, Zuber A (1996) Lumped parameter models for interpretation of environmental tracer data. Manual on mathematical models in isotope hydrogeology, IAEA-TECDOC-910. IAEA, Vienna, Austria, pp 9–58Google Scholar
  45. Manning AH, Solomon DK, Thiros SA (2005) 3H/3He age data in assessing the susceptibility of wells to contamination. Ground Water 43:353–367CrossRefGoogle Scholar
  46. Maupin MA, Barber NL (2005) Estimated withdrawals from principal aquifers in the United States, 2000. US Geol Surv Circ 1279, 49 ppGoogle Scholar
  47. McMahon PB, Böhlke JK, Kauffman LJ, Kipp KL, Landon MK, Crandall CA, Burow KR, Brown CJ (2008a) Source and transport controls on the movement of nitrate to public supply wells in selected principal aquifers of the United States. Water Resour Res. doi:10.1029/2007WR006252
  48. McMahon PB, Burow KR, Kauffman LJ, Eberts SM, Böhlke JK, Gurdak JJ (2008b) Simulated response of water quality in public supply wells to land-use change. Water Resour Res. doi:10.1029/2007WR006731
  49. Michel RL (1989) Tritium deposition in the continental United States, 1953–83. US Geol Surv Water Resour Invest Rep 89–4072, 46 ppGoogle Scholar
  50. Michigan DEQ (2009) Use of tritium in assessing aquifer vulnerability. Michigan Department of Environmental Quality WHP 1–109. Available online. http://www.michigan.gov/documents/deq/deq-wb-dwehs-swpu-tritiumanalysisguidance_212715_7.pdf. Cited 10 Nov 2009
  51. Nelms DL, Harlow GE Jr, Plummer LN, Busenberg E (2003) Aquifer susceptibility in Virginia, 1998–2000. US Geol Surv Water Res Invest Rep 03–4278, 58 ppGoogle Scholar
  52. Nir A (1986) Role of tracer methods in hydrology as a source of physical information: basic concepts and definitions—time relationship in dynamic systems. In: Mathematical models for interpretation of tracer data in groundwater hydrology, IAEA TECDOC-381. IAEA, Vienna, Austria, pp 7–44Google Scholar
  53. Osenbrück K, Fiedler S, Knöller K, Weise SM, Sültenfuß J, Oster H, Strauch G (2006) Timescales and development of groundwater pollution by nitrate in drinking water wells of the Jahna-Aue, Saxonia, Germany. Water Resour Res. doi:10.1029/2006WR004977
  54. Ozyurt NN, Bayari CS (2005) Steady- and unsteady-state lumped parameter modelling of tritium and chlorofluorocarbons transport: hypothetical analyses and application to an alpine karst aquifer. Hydrol Proc 19:3269–3284CrossRefGoogle Scholar
  55. Paschke SS, Kauffman LJ, Eberts SM, Hinkle SR (2007) Overview of regional studies of the transport of anthropogenic and natural contaminants to public-supply wells. In: Hydrogeologic settings and ground-water flow simulations for regional studies of the transport of anthropogenic and natural contaminants to public-supply wells—studies begun in 2001. US Geol Surv Prof Pap 1737-A, 1-1-1-18Google Scholar
  56. Peeters F, Beyerle U, Aeschbach-Hertig W, Holocher J, Brennwald MS, Kipfer R (2002) Improving noble gas based paleoclimate reconstruction and groundwater dating using 20Ne/22Ne ratios. Geochim Cosmochim Acta 67:587–600CrossRefGoogle Scholar
  57. Plummer LN, Busenberg E (2000) Chlorofluorocarbons, tools for dating and tracing young groundwater. In: Cook PG, Herczeg AL (eds) Environmental tracers in subsurface hydrology. Kluwer, BostonGoogle Scholar
  58. Plummer LN, Busenberg E (2006) Chlorofluorocarbons in the atmosphere. In: Use of chlorofluorocarbons in hydrology, a guidebook, IAEA STI/PUB/1238. IAEA, Vienna, Austria, pp 9–15Google Scholar
  59. Plummer LN, Busenberg E, Böhlke JK, Nelms DL, Michel RL, Schlosser P (2001) Groundwater residence times in Shenandoah National Park, Blue Ridge Mountains, Virginia, USA, a multi-tracer approach. Chem Geol 179:93–111CrossRefGoogle Scholar
  60. Plummer LN, Busenberg E, Eberts SM, Bexfield LM, Brown CJ, Fahlquist LS, Katz BG, Landon MK (2008) Low-level detections of halogenated volatile organic compounds in groundwater, use in vulnerability assessments. J Hydrol Eng 13:1049–1068CrossRefGoogle Scholar
  61. Poeter EP, Hill MC, Banta ER, Mehl S, Christensen S (2005) UCODE_2005 and six other computer codes for universal sensitivity analysis, calibration, and uncertainty evaluation. US Geol Surv Tech Methods 6-A11, 283 ppGoogle Scholar
  62. Pollock DW (1994) User’s guide for MODPATH/MODPATH-PLOT, Version 3: a particle tracking post-processing package for MODFLOW, the U.S. Geological Survey finite-difference ground-water flow model. US Geol Surv Open File Rep 94–464, variously paginatedGoogle Scholar
  63. Rupert MG, Plummer LN (2009) Groundwater quality, age, and probability of contamination, Eagle River Watershed valley-fill aquifer, North-Central Colorado, 2006–2007. US Geol Surv Water Res Invest Rep 2009–5082, 59 ppGoogle Scholar
  64. Scanlon BR, Mace RE, Barrett ME, Smith B (2003) Can we simulate regional groundwater flow in a karst system using equivalent porous media models? Case study, Barton Springs Edwards aquifer, USA. J Hydrol 276:137–158CrossRefGoogle Scholar
  65. Schlosser P, Stute M, Sonntag C, Munnich KO (1989) Tritiogenic 3He in shallow groundwater. Earth Planet Sci Lett 94:245–256CrossRefGoogle Scholar
  66. Solomon DK, Cook PG (2000) 3H and 3He. In: Cook PG, Herczeg AL (eds) Environmental tracers in subsurface hydrology. Kluwer, BostonGoogle Scholar
  67. Solomon DK, Poreda RJ, Schiff SL, Cherry JA (1992) Tritium and Helium 3 as groundwater age tracers in the Borden Aquifer. Water Resour Res 28:741–755CrossRefGoogle Scholar
  68. Spitz FJ (2001) Method and computer programs to improve pathline resolution near weak sinks representing wells in MODFLOW and MODPATH ground-water-flow simulations. US Geol Surv Open File Rep 00–392, 41 ppGoogle Scholar
  69. Starn JJ, Brown CJ (2007) Simulations of ground-water flow and residence time near Woodbury, Connecticut. US Geol Surv Sci Invest Rep 2007–5210, 45 ppGoogle Scholar
  70. Stewart JW, Goetz CL, Mills LR (1978) Hydrogeologic factors affecting the availability and quality of ground water in the Temple Terrace area, Hillsborough County, Florida. US Geol Surv Water Res Invest Rep 784, 38 ppGoogle Scholar
  71. Vogel JC (1967) Investigation of groundwater flow with radiocarbon. In: Isotopes in hydrology. IAEA, Vienna, Austria, pp 355–369Google Scholar
  72. Weissmann GS, Zhang Y, LaBolle EM, Fogg GE (2002) Dispersion of groundwater age in an alluvial aquifer system. Water Resour Res 38:1–8CrossRefGoogle Scholar
  73. Zinn BA, Konikow LF (2007) Potential effects of regional pumpage on groundwater age distribution. Water Resour Res. doi:10.1029/2006WR004865
  74. Zoellmann K, Kinzelbach W, Fulda C (2001) Environmental tracer transport (3H and SF6) in the saturated and unsaturated zones and its use in nitrate pollution management. J Hydrol 240:187–205CrossRefGoogle Scholar
  75. Zuber A (1986) On the interpretation of tracer data in variable flow systems. J Hydrol 86:45–57CrossRefGoogle Scholar
  76. Zuber A, Witczak S, Różański K, Śliwka I, Opoka M, Mochalski P, Kuc T, Karlikowska J, Kania J, Jackowicz-Korczyński M, Duliński M (2005) Groundwater dating with 3H and SF6 in relation to mixing patterns, transport modeling and hydrogeochemistry. Hydrol Proc 19:2247–2275CrossRefGoogle Scholar

Copyright information

© Springer-Verlag (outside the USA) 2011

Authors and Affiliations

  • S. M. Eberts
    • 1
  • J. K. Böhlke
    • 2
  • L. J. Kauffman
    • 3
  • B. C. Jurgens
    • 4
  1. 1.US Geological SurveyColumbusUSA
  2. 2.US Geological SurveyRestonUSA
  3. 3.US Geological SurveyWest TrentonUSA
  4. 4.US Geological SurveySacramentoUSA

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