Hydrogeology Journal

, Volume 22, Issue 4, pp 829–849 | Cite as

Evaluation of the importance of clay confining units on groundwater flow in alluvial basins using solute and isotope tracers: the case of Middle San Pedro Basin in southeastern Arizona (USA)

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Abstract

As groundwater becomes an increasingly important water resource worldwide, it is essential to understand how local geology affects groundwater quality, flowpaths and residence times. This study utilized multiple tracers to improve conceptual and numerical models of groundwater flow in the Middle San Pedro Basin in southeastern Arizona (USA) by determining recharge areas, compartmentalization of water sources, flowpaths and residence times. Ninety-five groundwater and surface-water samples were analyzed for major ion chemistry (water type and Ca/Sr ratios) and stable (18O, 2H, 13C) and radiogenic (3H, 14C) isotopes, and resulting data were used in conjunction with hydrogeologic information (e.g. hydraulic head and hydrostratigraphy). Results show that recent recharge (<60 years) has occurred within mountain systems along the basin margins and in shallow floodplain aquifers adjacent to the San Pedro River. Groundwater in the lower basin fill aquifer (semi confined) was recharged at high elevation in the fractured bedrock and has been extensively modified by water-rock reactions (increasing F and Sr, decreasing 14C) over long timescales (up to 35,000 years BP). Distinct solute and isotope geochemistries between the lower and upper basin fill aquifers show the importance of a clay confining unit on groundwater flow in the basin, which minimizes vertical groundwater movement.

Keywords

Confining units Groundwater age Hydrochemistry Numerical modeling USA 

Evaluation de l’importance des unités argileuses dans les bassins alluviaux sur l’écoulement d’eau souterraine en utilisant des traceurs dissous et des isotopes: cas du bassin moyen de San Pedro, Sud-Est de l’Arizona, USA

Résumé

L’eau souterraine devenant une ressource d’importance croissante à travers le monde, il est essentiel de comprendre comment la géologie locale affecte la qualité de l’eau souterraine, l’organisation des écoulements et les temps de séjour. Cette étude a utilisé des traceurs multiples pour améliorer les modèles d’écoulement souterrain conceptuel et numérique dans le Bassin Moyen de San Pedro, Sud-Est de l’Arizona (USA), en déterminant les aires de recharge, la compartimentation des venues d’eau, l’organisation des écoulements et les temps de séjour. Quatre-vingt quinze échantillons d’eau souterraine et d’eau de surface ont été analysés pour la chimie des ions majeurs (type d’eau et ratios Ca/Sr), isotopes stables (18O, 2H, 13C) et radiogéniques (3H, 14C), et les données résultantes utilisées en conjonction avec les données hydrogéologiques (e.g. charge hydraulique et hydro stratigraphie). Les résultats montrent que la recharge récente (<60 ans) a lieu dans les systèmes montagneux le long des marges du bassin et dans des aquifères peu profonds de plaine d’inondation le long de la rivière San Pedro. L’aquifère du bassin inférieur (semi-captif) est rechargé à une cote élevée dans le substrat fracturé et considérablement modifié par des réactions eau-roche (accroissement de F et Sr, décroissance du14C) sur de longues périodes de temps (jusqu’à 35 000 ans avant l’actuel). Les différences géochimiques des solutés et des isotopes entre le remplissage des aquifères des bassins supérieur et inférieur montrent l’importance de l’unité argileuse «confinante» sur les écoulements souterrains dans le bassin, qui minimise les mouvements verticaux de l’eau souterraine.

Evaluación de la importancia de las unidades arcillosas confinantes en el flujo de agua subterránea en cuencas aluviales usando trazadores isotópicos y solutos: el caso de la cuenca del Middle San Pedro en el sudeste de Arizona (EEUU)

Resumen

Puesto que el agua subterránea se convierte en un recurso de agua crecientemente más importante en todo el mundo, es esencial entender como la geología local afecta la calidad del agua subterránea, las trayectorias de flujo y los tiempos de residencias. Este estudio utilizó múltiples trazadores para mejorar los modelos conceptuales y numéricos del flujo de agua subterránea en la cuenca de Middle San Pedro en el sudeste de Arizona (EEUU) determinando las área de recarga, la compartimentación de las fuentes de agua, las trayectorias de flujo y los tiempos de residencia. Se analizaron noventa y cinco muestras de agua subterránea y de agua superficial en la búsqueda de los iones químicos principales (tipo de agua y relaciones Ca/Sr) e isótopos estables (18O, 2H, 13C) y radiogénicos (3H, 14C), y los datos resultantes fueron usados en conjunción con la información hidrogeológica (por ejemplo carga hidráulica e hidroestratigrafía). Los resultados muestran que ha ocurrido una recarga reciente (<60 años) dentro de los sistemas montañosos a lo largo de los márgenes de cuenca y en los acuíferos someros de la planicie de inundación adyacente al Río San Pedro. El agua subterránea en los acuíferos de relleno (semiconfinados) de la cuenca inferior fue recargada en las altas elevaciones en las rocas fracturadas del basamento y ha sido extensamente modificada por las reacciones agua – roca (incrementándose el F y Sr, y disminuyendo el 14C) a lo largo de grandes escalas de tiempo (hasta 35,000 años antes del presente). La geoquímica de distintos solutos y los isótopos en los acuíferos de relleno en la cuenca inferior y superior muestran la importancia de una unidad arcillosa confinante sobre el flujo de agua subterránea en la cuenca, lo que minimiza el movimiento vertical del agua subterránea.

Avaliação da importância das unidades confinantes de argila no fluxo de água em bacias aluviais através da utilização de traçadores solúveis e isotópicos: o caso da Bacia Média de San Pedro no sudeste do Arizona (EUA)

Resumo

À medida que a água subterrânea se torna progressivamente num importante recurso hídrico à escala mundial, é essencial perceber-se como a geologia local afeta a qualidade da água subterrânea, os caminhos de fluxo e os tempos de residência. Este estudo utilizou múltiplos traçadores para melhorar os modelos conceptuais e numéricos do fluxo de água subterrânea na Bacia Média de San Pedro, no sudeste do Arizona (EUA), através da determinação das áreas de recarga, da compartimentação das origens da água, dos caminhos de fluxo e dos tempos de residência. Foram analisadas noventa e cinco amostras de água subterrânea e superficial para o quimismo dos iões principais (tipos de água e rácios Ca/Sr), os isótopos estáveis (18O, 2H, 13C) e os radiogénicos (3H, 14C), tendo os dados resultantes sido usados em conjugação com informação hidrogeológica (p. ex. carga hidráulica e hidrostratigrafia). Os resultados mostram que a recarga recente (<60 anos) ocorreu nos sistemas montanhosos ao longo das margens da bacia e nas planícies de cheia baixas, adjacentes ao rio San Pedro. A água subterrânea no aquífero inferior do enchimento da bacia (semi-confinado) foi recarregada a cotas superiores no embasamento rochoso fraturado e foi extensivamente modificada por reações água-rocha (aumento de F e Sr, decréscimo de 14C) ao longo de extensas escalas temporais (até 35,000 anos antes do presente). As distintas geoquímicas dos solutos e dos isótopos entre os aquíferos superiores e inferiores no enchimento da bacia mostram a importância de uma unidade confinante de argila no fluxo de água subterrânea na bacia, a qual minimiza a movimentação vertical da água subterrânea.

References

  1. Anderson TW, Freethey GW, Tucci P (1992) Geohydrology and water resources of alluvial basins in south-central Arizona and parts of adjacent states. US Gov. Printing Office, Washington, DC, p 1406-BGoogle Scholar
  2. Arizona Daily Star (2005) Growth crawls toward Benson. Arizona Daily Star newspaper article published March 27, 2005. http://www.dailystar.com/. Accessed July 25, 2005
  3. Arizona Department of Water Resources (2005) Upper San Pedro Basin active management area review report. Arizona Department of Water Resources, Phoenix, AZ. http://www.azwater.gov/azdwr/. Accessed January 26, 2009
  4. Auken E, Jørgensen F, Sørensen KI (2003) Large-scale TEM investigation for groundwater. Explor Geophys 34:188–194CrossRefGoogle Scholar
  5. Baillie MN, Hogan JF, Ekwurzel B, Wahi AK, Eastoe CJ (2007) Quantifying water sources to a semiarid riparian ecosystem, San Pedro River, Arizona. J Geophys Res 112(G3), G03S02Google Scholar
  6. Burtell RT (1989) Geochemistry and occurrence of ground water in the Allen Flat Basin, Arizona. MSc Thesis, University of Arizona, USAGoogle Scholar
  7. Coes A (1997) A geochemical approach to determine ground-water flow patterns in the Sierra Vista basin, Arizona, with special emphasis on ground-water/surface-water interaction. MSc Thesis, University of Arizona, USAGoogle Scholar
  8. Coes A, Pool D (2007) Ephemeral-stream channel and basin-floor infiltration and recharge in the Sierra Vista subwatershed of the Upper San Pedro Basin, southeastern Arizona. US Geol Surv Prof Pap 1703-J, pp 253–311Google Scholar
  9. Coleman ML, Moore MP (1978) Direct reduction of sulfates to sulfur dioxide for isotopic analysis. Anal Chem 50:1594–1598CrossRefGoogle Scholar
  10. Craig H (1957) Isotopic standards for carbon and oxygen and correction factors for mass spectrometric analysis of carbon dioxide. Geochem Cosmochim Acta 12:133–149CrossRefGoogle Scholar
  11. Dickinson WR (1991) Tectonic setting of faulted Tertiary strata associated with the Catalina core complex in southern Arizona. Geol Soc Am Spec Pap 264, 106 ppGoogle Scholar
  12. Dickinson JE, Hanson RT, Ferre TPA, Leake SA (2004) Inferring time-varying recharge from inverse analysis of long-term water levels. Water Resour Res 40, W07403Google Scholar
  13. Dickinson JE, Kennedy JR, Cordova JT, Parker JT, Macy JP, Blakemore T (2010a) Hydrogeologic framework of the Middle San Pedro watershed, southeastern Arizona. US Geol Surv Sci Invest Rep 2010-5126, 36 ppGoogle Scholar
  14. Dickinson JE, Pool DR, Groom RW, Davis LJ (2010b) Inference of lithologic distributions in an alluvial aquifer using airborne transient electromagnetic surveys. Geophysics 75:WA149–WA161CrossRefGoogle Scholar
  15. Earman S, McPherson BJOL, Phillips FM, Ralser S, Herrin JM, Broska J (2008) Tectonic influences on ground water quality: insight from complementary methods. Ground Water 46(3):354–371CrossRefGoogle Scholar
  16. Eastoe CJ, Gu A, Long A (2004) The origins, ages, and flow paths of groundwater in Tucson Basin: results of a study of multiple isotope systems. In: Hogan JF, Phillips FM, Scanlon BR (eds) Groundwater recharge in a desert environment: the southwestern United States. Am Geophys Union, Washington, DC, pp 217–234Google Scholar
  17. Eastoe CJ, Watts CJ, Ploughe M, Wright WE (2011) Future use of tritium in mapping pre-bomb groundwater volumes. Ground Water 50(1):87–93CrossRefGoogle Scholar
  18. Eastoe CJ, Watts CJ, Ploughe M, Wright WE (2012) Future use of tritium in mapping pre-bomb groundwater volumes. Ground Water 50(1):87–93Google Scholar
  19. Edmunds WM, Smedley PL (2000) Residence time indicators in groundwater: the East Midlands Triassic Sandstone Aquifer. Appl Geochem 15:737–752CrossRefGoogle Scholar
  20. Fenneman NM (1931) Physiography of western United States, 1st edn. McGraw–Hill, New YorkGoogle Scholar
  21. Fordyce FM, Vrana K, Zhovinsky E, Povoroznuk V, Toth G, Hope BC, Iljinsky U, Baker J (2007) A health risk assessment for fluoride in Central Europe. Environ Geochem Health 29:83–102CrossRefGoogle Scholar
  22. Freethey GW (1982) Hydrologic analysis of the Upper San Pedro Basin from the Mexico-United States boundary to Fairbank, Arizona. US Geol Surv Open-File Rep 82-752Google Scholar
  23. Gehre M, Hoefling R, Kowski P, Strauch G (1996) Sample preparation device for quantitative hydrogen isotope analysis using chromium metal. Anal Chem 68:4414–4417CrossRefGoogle Scholar
  24. Gieskes JM, Rogers CW (1973) Alkalinity determination in interstitial waters of marine sediments. J Sediment Petrol 43:272–277Google Scholar
  25. Goode TC, Maddock T III (2000) Simulation of groundwater conditions in the Upper San Pedro Basin for the evaluation of alternative futures. HWR No. 00-030, University of Arizona, Tuscon, AZ, 113 ppGoogle Scholar
  26. Huckleberry G (1996) Historical changes on the San Pedro River, southeastern Arizona. Open-file report 96-15, Arizona Geological Survey, Tuscon, AZGoogle Scholar
  27. Jacks G, Bhattacharya P, Chaundhary V, Singh KP (2005) Controls on the genesis of some high-fluoride groundwaters in India. Appl Geochem 20:221–228CrossRefGoogle Scholar
  28. Larsen D, Gentry RW, Solomon DK (2003) The geochemistry and mixing of leakage in a semi-confined aquifer at a municipal well field, Memphis, Tennessee, USA. Appl Geochem 18(7):1043–1063CrossRefGoogle Scholar
  29. Leake SA, Reeves HW, Dickinson JE (2010) A new capture fraction method to map how pumpage affects surface water flow. Ground Water 48(5):690–700CrossRefGoogle Scholar
  30. McDonald MG, Harbaugh AW (1988) A modular three-dimensional finite-difference ground-water flow model. US Dept. of the Interior, Reston, VAGoogle Scholar
  31. McPherson GR, Boutton TW, Midwood AJ (1993) Stable carbon isotope analysis of soil organic matter illustrates vegetation change at the grassland/woodland boundary in southeastern Arizona, USA. Oecologia 93:95–101Google Scholar
  32. Plummer NL, Prestemon EC, Parkhurst DL (1994) An interactive code (NETPATH) for modeling NET geochemical reactions along a flow PATH version 2.0. US Geol Surv Open-File Rep 94-4169Google Scholar
  33. Plummer NL, Bexfield LM, Anderholm SK, Sanford WE, Busenberg E (2004) Hydrochemical tracers in the Middle Rio Grande Basin, USA: conceptualization of groundwater flow. Hydrogeol J 12:359–388CrossRefGoogle Scholar
  34. Pollock DW (1994) MODPATH a particle tracking post-processing model for MODFLOW. US Geol Surv Open-File Rep 94-463Google Scholar
  35. Pool DR, Coes AL (1999) Hydrogeologic investigations of the Sierra Vista Subwatershed of the Upper San Pedro Basin, Cochise County, southeast Arizona. US Geol Surv Water Resour Invest Rep 99-4197Google Scholar
  36. Robertson FN (1989) Arsenic in ground-water under oxidizing conditions, South-West United States. Environ Geochem Health 11:171–185CrossRefGoogle Scholar
  37. Robertson FN (1991) Geochemistry of ground water in alluvial basins of Arizona and adjacent parts of Nevada, New Mexico, and California. US Geol Surv Prof Pap 1406-CGoogle Scholar
  38. Robertson FN (1992) Radiocarbon dating of groundwater in a confined aquifer in southeast Arizona. Radiocarbon 34:664–676Google Scholar
  39. Roeske RH, Werrell WL (1971) Hydrologic conditions in the San Pedro River Valley, Arizona. Bull 4, Arizona Water Commission, Phoenix, AZ, 76 ppGoogle Scholar
  40. Sanford WE, Plummer LN, McAda DP, Bexfield LM, Anderholm SK (2004) Hydrochemical tracers in the middle Rio Grande Basin, USA: 2. calibration of a groundwater-flow model. Hydrogeol J 12:389–407CrossRefGoogle Scholar
  41. Simpson SC (2007) Modeling stream-aquifer interactions during floods and baseflow: Upper San Pedro River, southeastern Arizona. MSc Thesis, University of Arizona, USAGoogle Scholar
  42. Theodorsson P (1996) Low-level counting: past - present - future. Appl Radiat Isot 47(9/10):827–834CrossRefGoogle Scholar
  43. US Geological Survey (variously dated) National field manual for the collection of water-quality data. US Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1–A9. http://pubs.water.usgs.gov/twri9A. Accessed September 26, 2008
  44. Usunoff EJ (1984) Hydrochemistry of the San Pedro River Basin near Saint David, Cochise County, Arizona, with special emphasis on the behavior of fluoride. MSc Thesis, University of Arizona, USAGoogle Scholar
  45. Wahi AK, Hogan JF, Ekwurzel B, Eastoe CJ (2008) Geochemical quantification of semiarid mountain recharge. Ground Water 46:414–425CrossRefGoogle Scholar
  46. Western Regional Climate Center (2009) Historical data. http://www.wrcc.dri.edu/. Accessed June 10, 2009
  47. Zhu C, Waddell RK, Star I, Ostrander M (2010) Responses of ground water in the Black Mesa basin, northeastern Arizona, to paleoclimactic changes during the late Pleistocene and Holocene. Geology 38:83–86CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg (outside the USA) 2014

Authors and Affiliations

  • Candice B. Hopkins
    • 1
    • 4
  • Jennifer C. McIntosh
    • 1
  • Chris Eastoe
    • 2
  • Jesse E. Dickinson
    • 3
  • Thomas Meixner
    • 1
  1. 1.Department of Hydrology and Water ResourcesUniversity of ArizonaTucsonUSA
  2. 2.Department of GeosciencesUniversity of ArizonaTucsonUSA
  3. 3.United States Geological SurveyTucsonUSA
  4. 4.United States Geological SurveyBoiseUSA

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