Hydrogeochemical processes, mixing and isotope tracing in hard rock aquifers and surface waters from the Subarnarekha River Basin, (east Singhbhum District, Jharkhand State, India)

Geochemical observations, including major ion and trace element analysis, and isotopic tracing have been carried out in the Subarnarekha River system (northeastern India) during a surface-water- and groundwater-monitoring program aimed at evaluating impacts of mining. The aquifer is of fracture type. Groundwater flow conditions and pollutant transfer were observed through a network of 69 wells. δ18O and δ2H results suggest that transfer from rainfall towards groundwater storage through soils and the unsaturated zone is fast, without any major transformation like evaporation. The scatter of 87Sr/86Sr signatures in surface water and groundwater are explained by three end-members. One is compatible with rainwater inputs. The most mineralised end-member represents anthropogenic inputs (agricultural practices and ore processing). The third end-member, characterised by a high 87Sr/86Sr signature, is believed to be controlled by natural geochemical processes, although affected by human activities (e.g. drainage of mine waste). Potential flow paths, investigated north of the area, reveal that all groundwater types seem to evolve more in pockets than along a flow path. The limited extent of transfer and the predominance of natural phenomena help to explain the moderate level of groundwater contamination and the characteristics of surface water contamination by mining and the metallurgy industry.RésuméDes études géochimiques dont une analyse des ions majeurs et des éléments en trace, ainsi qu’un traçage isotopique, ont été effectuées sur le système de la rivière Subarnarekha (au nord-est de l’Inde) lors d’un programme de surveillance des eaux de surface et souterraines dont le but était d’évaluer les impacts liés à l’activité minière. L’aquifère est de type aquifère fracturé. Les conditions d’écoulement des eaux souterraines et le transfert de polluant ont été étudiés grâce à un réseau de 69 puits. Les valeurs de δ18O et δ2H suggèrent un transfert rapide de la pluie vers la ressource en eau souterraine à travers les sols et la zone non-saturée, sans aucune transformation majeure telle que l’évaporation. La distribution des signatures 87Sr/86Sr dans les eaux de surface et souterraines est expliquée par trois pôles. L’un est compatible avec le signal d’entrée des eaux de pluie. Le pôle le plus minéralisé représente le signal d’entrée anthropique (pratiques agricoles et traitements des minerais). Le troisième pôle, caractérisé par une signature de 87Sr/86Sr élevée, est supposé être contrôlé par des processus géochimiques naturels, bien qu’affectés par des activités humaines (le drainage de déchets miniers par exemple). Les trajectoires d’écoulement potentiel, étudiées dans le nord de la zone, revèlent que tous les types d’eau souterraine semblent évoluer plus dans des poches que le long de lignes d’écoulement. L’étendue limitée du transfert et la prédominance des phénomènes naturels aident à expliquer le niveau modéré de la contamination de l’eau souterraine et les caractéristiques de la contamination de l’eau de surface par l’industrie minière et métallurgique.ResumenEn el sistema del Río Subarnarekha (Noreste de la India), se han tomado datos geoquímicos, incluyendo análisis de mayores, elementos traza y trazadores isotópicos dentro de un programa de monitorización de aguas superficiales y subterráneas dedicado a la evaluación del impacto de la minería. El acuífero presenta porosidad por fracturación. Las condiciones de flujo del agua subterránea y la transferencia de contaminantes fueron observados en una red de 69 pozos. Los resultados de δ18O y δ2H sugieren que la recarga de la lluvia hacia el almacenamiento de las aguas subterráneas a través de los suelos y la zona no saturada es rápida, sin ninguna transformación importante como evaporación. La dispersión de la relación 87Sr/86Sr en las aguas superficiales y subterráneas se explican por la existencia de tres tipos de agua extremos. Uno de ellos es compatible con la entrada de agua de lluvia. El extremo más mineralizado representa las entradas antrópicas (prácticas agrícolas y procesado de minerales). El tercer extremo, caracterizado por valores altos de la relación 87Sr/86Sr, se piensa que está controlado por procesos geoquímicos naturales, aunque afectados por actividades humanas (por ejemplo, drenaje de residuos mineros). Las líneas de flujo potenciales, investigadas al norte del área, revelan que todos tipos de aguas subterráneas parecen evolucionar más en bolsas que a lo largo de líneas de flujo. El alcance limitado de la transferencia y predominancia de los fenómenos naturales ayuda a explicar el nivel moderado de la contaminación de las aguas subterráneas y las características de la contaminación de las aguas superficiales por la industria minera y metalúrgica.

[1]  D. Widory,et al.  Strontium isotope geochemistry of alluvial groundwater: a tracer for groundwater resources characterisation , 2004 .

[2]  M. Meybeck.  Composition chimique des ruisseaux non pollués en France. Chemical composition of headwater streams in France , 1986 .

[3]  S. Krishnaswami,et al.  The Indus river system (India-Pakistan): Major-ion chemistry, uranium and strontium isotopes☆ , 1994 .

[4]  R. Ramesh,et al.  Chemical and Strontium, Oxygen, and Carbon Isotopic Compositions of Carbonates from the Lesser Himalaya: Implications to the Strontium Isotope Composition of the Source Waters of the Ganga, Ghaghara, and the Indus Rivers , 1998 .

[5]  B. Dupré,et al.  Erosion sources determined by inversion of major and trace element ratios and strontium isotopic ratios in river water: the Congo Basin case , 1993 .

[6]  D. L. Parkhurst,et al.  User's guide to PHREEQC (Version 2)-a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations , 1999 .

[7]  J. Luck,et al.  Geochemistry and water dynamics: application to short time-scale flood phenomena in a small Mediterranean catchment , 1997 .

[8]  C. Kendall,et al.  Kinetic and mineralogic controls on the evolution of groundwater chemistry and 87Sr/86Sr in a sandy silicate aquifer, northern Wisconsin, USA , 1996 .

[9]  R. Ramesh,et al.  Strontium isotopes and rubidium in the Ganga-Brahmaputra river system: Weathering in the Himalaya, fluxes to the Bay of Bengal and contributions to the evolution of oceanic87Sr/86Sr , 1992 .

[10]  V. Singh,et al.  Flow regime associated with partially penetrating large-diameter wells in hard rocks , 1988 .

[11]  A. Mukherjeea,et al.  Seasonal variations in the isotopes of oxygen and hydrogen in geothermal waters from Bakreswar and Tantloi , Eastern India : implications for groundwater characterization , 2005 .

[12]  V. Jayaraman,et al.  Groundwater resources development in hard rock terrain - an approach using remote sensing and GIS techniques , 2000 .

[13]  M. Leybourne,et al.  Hydrogeochemical, isotopic, and rare earth element evidence for contrasting water-rock interactions at two undisturbed Zn-Pb massive sulphide deposits, Bathurst Mining Camp, N.B., Canada , 1998 .

[14]  A. Long.  The Geochemistry of Natural Waters , 1997 .

[15]  R. Stallard,et al.  The fluvial geochemistry and denudation rate of the Guayana Shield in Venezuela, Colombia, and Brazil , 1995 .

[16]  H. Pauwels,et al.  Interaction between Different Groundwaters in Brittany Catchments (France): Characterizing Multiple Sources through Strontium- and Sulphur Isotope Tracing , 2004 .

[17]  B. Dupré,et al.  Chemical and physical denudation in the Amazon River Basin , 1997 .

[18]  C. Silva.  Optimising the dimensions of agrowells in hard-rock aquifers in Sri Lanka , 1997 .

[19]  Jing Zhang,et al.  Drainage basin weathering and major element transport of two large Chinese rivers (Huanghe and Changjiang) , 1990 .

[20]  D. Siegel,et al.  87Sr/86Sr as a tracer of groundwater discharge and precipitation recharge in the Glacial Lake Agassiz Peatlands, northern Minnesota , 2000 .

[21]  T. Coplen.  Stable Isotope Hydrology: Deuterium and Oxygen‐18 in the Water Cycle , 1982 .

[22]  Ivars Neretnieks,et al.  A stochastic multi-channel model for solute transport--analysis of tracer tests in fractured rock. , 2002, Journal of contaminant hydrology.

[23]  P. Pitkänen,et al.  Hydrogeochemical interpretation of groundwater at Palmottu , 2002 .

[24]  R. Singh,et al.  Hydrogeochemical exploration for unconformity-related uranium mineralization: example from Palnadu sub-basin, Cuddapah Basin, Andhra Pradesh, India , 2002 .

[25]  W. Moore,et al.  Major ion chemistry of the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal , 1989 .

[26]  P. K. Sikdar,et al.  Geochemical evolution of groundwater in the Quaternary aquifer of Calcutta and Howrah, India , 2001 .

[27]  V. Guinn.  Principles of Isotope Geology , 1978 .

[28]  P. Lachassagne,et al.  Geochemistry of the Maroni River (French Guiana) during the low water stage: implications for water–rock interaction and groundwater characteristics , 2000 .

[29]  P. J. Chilton,et al.  Groundwater and its susceptibility to degradation : a global assessment of the problem and options for management , 2003 .

[30]  S. Sengupta,et al.  Tectonic deformation of soft-sediment convolute folds , 2002 .

[31]  D. Chandrasekharam,et al.  Arsenic enrichment in groundwater of West Bengal, India: geochemical evidence for mobilization of As under reducing conditions , 2003 .

[32]  C. Talbot,et al.  Stress control of hydraulic conductivity in fracture-saturated Swedish bedrock , 2001 .

[33]  C. Langmuir,et al.  A general mixing equation with applications to Icelandic basalts , 1978 .

[34]  Ramaswamy Sakthivadivel,et al.  Over-exploitation and artificial recharging of hard rock aquifers of South India: issues and options. IWMI-TATA Water Policy Research Program Annual Partners' Meet, 2002 , 2002 .

[35]  J. Gat,et al.  Stable isotope hydrology : deuterium and oxygen-18 in the water cycle , 1981 .

[36]  J. Edmond,et al.  The fluvial geochemistry of the rivers of Eastern Siberia: I. tributaries of the Lena River draining the sedimentary platform of the Siberian Craton , 1998 .

[37]  C. Grosbois,et al.  An Overview of Dissolved and Suspended Matter Fluxes in the Loire River Basin: Natural and Anthropogenic Inputs , 2001 .

[38]  J. Edmond,et al.  The fluvial geochemistry of the rivers of Eastern Siberia: III. Tributaries of the Lena and Anabar draining the basement terrain of the Siberian Craton and the Trans-Baikal Highlands , 1999 .

[39]  P. Smedley,et al.  Hydrogeology and hydrogeochemistry of a small, hard-rock island — the heavily stressed aquifer of Jersey , 1994 .

[40]  Hans-Peter Schertl,et al.  Geochim. cosmochim. acta , 1989 .

[41]  S. Gupta,et al.  Groundwater δ18O and δD from central Indian Peninsula: influence of the Arabian Sea and the Bay of Bengal branches of the summer monsoon , 2005 .

[42]  R. Poreda,et al.  The groundwater geochemistry of the Bengal Basin: Weathering, chemsorption, and trace metal flux to the oceans , 2003 .

[43]  L. Derry,et al.  The strontium isotopic budget of Himalayan rivers in Nepal and Bangladesh , 1999 .

[44]  P. Négrel,et al.  Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields , 2005 .

[45]  S. Gupta,et al.  Distribution of oxygen and hydrogen isotopes in shallow groundwaters from Southern India: influence of a dual monsoon system , 2003 .

[46]  D. C. Singhal,et al.  Integrated approach to aquifer delineation in hard rock terrains ― a case study from the Banda District, India , 1988 .

[47]  S. Foster.  Groundwater in Rural Development: Facing the Challenges of Supply and Resource Sustainability , 2000 .

[48]  P. Négrel,et al.  Strontium isotope systematics used to decipher the origin of groundwaters sampled from granitoids: the Vienne Case (France) , 2001 .

[49]  P. Deschamps,et al.  Natural and anthropogenic budgets of a small watershed in the massif central (France): Chemical and strontium isotopic characterization of water and sediments , 1996 .