<p>Osnovni cilj istraživanja u okviru doktorske disertacije je definisanje<br />kriterijuma na osnovu optimizacije usvojenog stepena sorbiranja i<br />degradacije za modele transporta farmaceutika u aluvijalnim podzemnim<br />vodama, koji služe kao polazna osnova za postavke budućih izvori&scaron;ta<br />podzemne vode. Dobijeni su novi podaci i informacije koje će se koristiti za<br />procenu pona&scaron;anja farmaceutika, kao i za projektovanje i optimizaciju novih<br />sistema za efikasnu za&scaron;titu i upravljanje podzemnim vodama. Potpuno novi<br />rezultati se odnose na određivanje stepena eliminacije farmaceutika tokom<br />primene metode rečne obalske filtracije, kao i teorijsko i eksperimentalno<br />poređenje realnih podataka o stepenu sorbiranja i razgradnje farmaceutika.</p> / <p>The main goal of dissertation is to define new criteria based on the<br />optimization of applied sorption and degradation degree for groundwater<br />pharmaceuticals transport model, which serve as a basis for development<br />and design of the future drinking water facilities. New data and information&rsquo;s<br />are obtained and can be used for assessment of pharmaceutical behavior in<br />alluvial groundwater and for design of new and innovative systems for more<br />efficient protection and groundwater management. Novel results are referred<br />on the determination of the pharmaceuticals elimination during river bank<br />filtration and on the theoretical and experimental comparison of real data for<br />the sorption and degradation capacity of selected pharmaceuticals.</p>

Seit mehr als 100 Jahren wird Oberflächenwasser mit verschiedenen Verfahren versickert, wobei sich dessen Qualität stark verbessert. Sie finden zunehmend weltweit Anwendung, um eine zuverlässige Versorgung mit sauberem Trinkwasser zu gewährleisten. Solche Verfahren erfordern nur einen geringen technischen Aufwand. Während bei der Versicherung mit Schluckbrunnen und bei künstlichen Infiltrationsbecken das Wasser noch gepumpt und oft auch vorgereinigt werden muss, reduziert die Nutzung eines natürlichen Gewässers den Aufwand nochmals. Am Beispiel eines Untersuchungsgebiets am Tegeler See in Berlin werden die hydraulischen Prozesse modelliert. Die regionale, instationäre und 3-dimensionale Modellierung eines langen Zeitraums zeigt, dass die bisher verwendeten linearen Ansätze zur Beschreibung der Durchlässigkeit der Kolmationsschicht sowohl die infiltrierten Wassermengen als auch die Infiltrationsprozesse nur unzureichend wiedergeben. Grundwasserpiegelschwankungen werden stärker als bisher angenommen gedämpft. Als Folge dieser Wasserspiegelschwankungen wird die Bodenluft in der ungesättigten Bodenzone ausgetauscht und Sauerstoff eingetragen. Auf diese Weise erhöht sich die Durchlässigkeit der Kolmationsschicht um mindestens eine Größenordnung. Auf Grundlage dieser Ergebnisse wurden eine instationäre Wasserbilanz aufgestellt und die Uferfiltratanteile bestimmt. Die genaue lokale Lage eines Grundwasserstauers wird mit Hilfe eines neu entwickelten inversen Modellkonzeptes bestimmt. Er wird mit räumlich verteilten Pilot Points und Überparameterisierung unter Nebenbedingungen kalibriert. Die Zielgröße sind Piezometerhöhenschwankungen. Kreuzvalidierung bestätigt, dass die Lage des Grundwasserstauers präzise bestimmt wird. Diese hat einen entscheidenden Einfluss auf das räumliche Strömungsfeld und liefert neue Anhaltspunkte zur Genese des Tegeler Sees. Ein Transportmodell liefert lediglich mit den hydraulisch kalibrierten Parametern eine genaue Anpassung der Durchbruchskurven von Chlorid, 18O und Temperatur. Dies kann als Vorhersage angesehen werden und zeigt die Güte des Modells. Es konnte gezeigt werden, dass der Sauerstoffeintrag die Redoxprozesse in der Infiltrationszone dominiert. In Kombination mit der Lage des Grundwasserstauers können so auch zuvor widersprüchliche und lokale geochemische Verhältnisse schlüssig interpretiert werden. Es wird eine Theorie entwickelt, die erklärt, wie die vertikale Schichtung von oxidiertem und reduziertem Wasser zu starker Verockerung der Brunnen führt. / Several kinds of managed aquifer recharge techniques provide very good purification of surface water since more than 100 years. In order to maintain a reliable supply of clean water, they are becoming increasingly popular all over the world. These methods require low technical effort. At Aquifer Storage and Recovery and ponded infiltration the recharged amounts are technically controlled. The infiltration water has to be pumped and often pretreated. At bank filtration this is dispensable, the approach, of using existing surface water bodies is even more consequent. Exemplarily, at a test site at Lake Tegel, Berlin, Germany, the hydraulic processes are modelled. By means of 3D long term regional and transient hydraulic modelling it was detected that the existing approaches for determining the leakance induce large errors in the water balance and describe the infiltration zone insufficiently. The leakance could be identified to be triggered by the groundwater table, causing air exchange and intrusion of atmospheric oxygen, which reduces clogging by altered redox conditions by at least one order of magnitude. This causes that changes of the groundwater table are mitigated much more than previously assumed. Taking these findings into account, a transient water balance is determined and bank filtration ratios are quantified. A new inverse modelling concept has been developed and applied to a 3D short term local and transient hydraulic model. It comprises spatially distributed pilot points and overparameterisation constrained by regularisation and calibration to head differences. Significance of the results is demonstrated by cross validation. With this approach the spatial distribution of an aquitard have been identified with high precision. The highly transient and heterogeneous flow conditions are specified and a new viewpoint on the geologic formation of Lake Tegel is obtained. The good fit of modelled and observed breakthrough curves of 18O, chloride and temperature by just using transferred parameters obtained with the previous hydraulic methods, show the very good model performance and predictive capabilities. The intrusion of atmospheric oxygen into the unsaturated zone is identified to be the principal redox determining factor during infiltration. Previously inconsistent and also local geochemical conditions are identified to be determined by interaction of infiltration processes with the spatial extent of the aquitard. A theory for chemical clogging of abstraction wells is developed, identifying the strong vertical redox zoning as principal factor of influence.

No description available.

No description available.

Die Uferfiltration (UF) ist eine potentielle Alternative zur konventionellen Oberflächenwasseraufbereitung in Indien, da Trübstoffe, pathogene Mikroorganismen und organische Wasserinhaltsstoffe effektiv entfernt werden. In dieser Arbeit wurde erstmals ein umfangreicher Überblick zu bestehenden UF-Anlagen in Indien erarbeitet. Für die Standorterkundung und -bewertung wurde ein Konzept erarbeitet, das an drei Standorten entlang des Ganges getestet und weiterentwickelt wurde. Das Konzept umfasst vier Stufen: Standortvorerkundung, Bestimmung von Grundwasserleiterparametern, Erfassung von hydraulischen und Beschaffenheits-parametern sowie numerische Grundwasser-strömungsmodellierung. Entlang des oberen Flusslaufes des Ganges (Haridwar und Srinagar) wurden günstige geohydraulische Verhältnisse identifiziert (kf = 10E-4 bis 10E-3 m/s, Grundwasser leitermächtigkeit 11 bis 20 m). Entlang des unteren Flusslaufes (Patna) gibt es in Abhängigkeit von der Mächtigkeit der Sedimentablagerungen im Ganges nur bei erhöhter Schleppkraft im Monsun eine gute hydraulische Verbindung zwischen dem Fluss und dem Grundwasserleiter. In Haridwar wurde der Uferfiltratanteil im Rohwasser mittels Isotopenanalysen (δ18O) und Leitfähigkeitsmessungen im Fluss- und Rohwasser ermittelt. Der Uferfiltratanteil in den auf einer Insel und südlich davon gelegenen Brunnen liegt bei bis zu 90%. An den untersuchten Standorten wird durch die UF eine effektive Entfernung von E. coli um 3,5 bis 4,4 Log10 und der Trübung bis >2 Log10 Einheiten erreicht. Eine Entfernung von 3 Log10 Einheiten wurde bereits bei einer Fließzeit des Uferfiltrats von zwei Tagen beobachtet. Die erhöhte Anzahl an Coliformen in einigen Brunnen am Standort Haridwar resultiert aus Verunreinigungen des landseitigen Grundwassers. Bei Hochwässern und Starkregenereignissen muss eine Kontamination durch den direkten Eintrag von Wasser durch undichte Brunnenabdeckungen, Risse in den Schächten bzw. unsachgemäßen Brunnenbau berücksichtigt werden. Die Anwendung des angepassten Untersuchungskonzepts an 15 weiteren UF-Standorten in Indien hat gezeigt, dass die niedrigen DOC-Konzentrationen im Flusswasser (0,9 bis 3,0 mg/L) und im Brunnenwasser (0,4 bis 2,3 mg/L) günstig für die Anwendung der UF sind. Bei erhöhten DOC-Konzentrationen (Vormonsun) im Flusswasser konnte in Delhi und Mathura im Monsun eine 50%ige Verminderung erreicht werden. Bei der Erkundung neuer UF-Standorte in bergigen Gebieten sind die Grundwasserleitermächtigkeit mit geophysikalischen Erkundungsverfahren, die Strömungsverhältnisse in den alluvialen Ablagerungen sowie lokale Hochwasserrisiken zu untersuchen. / Riverbank filtration or bank filtration (RBF / BF) is a potential alternative to the direct abstraction and conventional treatment of surface water by virtue of the effective removal of pathogens, turbidity, suspended particles and organic substances. A comprehensive overview of existing RBF systems in India has been compiled for the first time. To systematically select and investigate new and existing potential RBF sites in India, a methodological concept was developed and tested at three sites along the Ganga River. The four stages of the concept are: initial site-assessment, basic site-survey, monitoring of water quality and quantity parameters and determination of aquifer parameters and numerical groundwater flow modelling. Suitable geohydraulic conditions for RBF (hydraulic conductivity: 10E-4 to 10E-3 m/s, aquifer thickness: 11 to 20 m) exist along the upper course of the Ganga (Haridwar and Srinagar). Due to the presence of fine sediment layers beneath the river bed along the Ganga’s lower course (Patna), river-aquifer interaction occurs during increased shear stress on the riverbed in monsoon. The portion of bank filtrate abstracted by the wells in Haridwar was determined from isotope analyses (Oxygen 18) and electrical conductivity measurements of river and well water and is up to 90% for wells located on an island and between the river and a canal. The results were confirmed by groundwater flow modelling. A high removal of E. coli (3.5 to 4.4 Log10 units) and turbidity (>2 Log10 units) was observed at the investigated sites. An E. coli removal of 3 Log10 units was observed for short travel times of 2 days. Higher coliform counts in some wells occur due to contamination from landside groundwater. During floods and intense rainfall events, contamination of RBF wells from direct entry of flood water, seepage of surface runoff into the well through leaky covers, fissures in the well-heads / caissons and in-appropriately sealed well-bases has to be considered. The application of the adapted investigation concept to 15 other sites in India showed that the low DOC concentrations in river water (0.9 to 3.0 mg/L) and well-water (0.4 to 2.3 mg/L) are favourable for the application of RBF. A 50% decrease of the high (pre-monsoon) DOC concentration was observed during monsoon in Delhi and Mathura. For the exploration of new RBF sites in hilly / mountainous areas, investigations of the aquifer thickness using geophysical methods, subsurface flow conditions in the alluvial deposits and the risk from floods should be conducted.

Die Uferfiltration (UF) ist eine potentielle Alternative zur konventionellen Oberflächenwasseraufbereitung in Indien, da Trübstoffe, pathogene Mikroorganismen und organische Wasserinhaltsstoffe effektiv entfernt werden. In dieser Arbeit wurde erstmals ein umfangreicher Überblick zu bestehenden UF-Anlagen in Indien erarbeitet. Für die Standorterkundung und -bewertung wurde ein Konzept erarbeitet, das an drei Standorten entlang des Ganges getestet und weiterentwickelt wurde. Das Konzept umfasst vier Stufen: Standortvorerkundung, Bestimmung von Grundwasserleiterparametern, Erfassung von hydraulischen und Beschaffenheits-parametern sowie numerische Grundwasser-strömungsmodellierung. Entlang des oberen Flusslaufes des Ganges (Haridwar und Srinagar) wurden günstige geohydraulische Verhältnisse identifiziert (kf = 10E-4 bis 10E-3 m/s, Grundwasser leitermächtigkeit 11 bis 20 m). Entlang des unteren Flusslaufes (Patna) gibt es in Abhängigkeit von der Mächtigkeit der Sedimentablagerungen im Ganges nur bei erhöhter Schleppkraft im Monsun eine gute hydraulische Verbindung zwischen dem Fluss und dem Grundwasserleiter. In Haridwar wurde der Uferfiltratanteil im Rohwasser mittels Isotopenanalysen (δ18O) und Leitfähigkeitsmessungen im Fluss- und Rohwasser ermittelt. Der Uferfiltratanteil in den auf einer Insel und südlich davon gelegenen Brunnen liegt bei bis zu 90%. An den untersuchten Standorten wird durch die UF eine effektive Entfernung von E. coli um 3,5 bis 4,4 Log10 und der Trübung bis >2 Log10 Einheiten erreicht. Eine Entfernung von 3 Log10 Einheiten wurde bereits bei einer Fließzeit des Uferfiltrats von zwei Tagen beobachtet. Die erhöhte Anzahl an Coliformen in einigen Brunnen am Standort Haridwar resultiert aus Verunreinigungen des landseitigen Grundwassers. Bei Hochwässern und Starkregenereignissen muss eine Kontamination durch den direkten Eintrag von Wasser durch undichte Brunnenabdeckungen, Risse in den Schächten bzw. unsachgemäßen Brunnenbau berücksichtigt werden. Die Anwendung des angepassten Untersuchungskonzepts an 15 weiteren UF-Standorten in Indien hat gezeigt, dass die niedrigen DOC-Konzentrationen im Flusswasser (0,9 bis 3,0 mg/L) und im Brunnenwasser (0,4 bis 2,3 mg/L) günstig für die Anwendung der UF sind. Bei erhöhten DOC-Konzentrationen (Vormonsun) im Flusswasser konnte in Delhi und Mathura im Monsun eine 50%ige Verminderung erreicht werden. Bei der Erkundung neuer UF-Standorte in bergigen Gebieten sind die Grundwasserleitermächtigkeit mit geophysikalischen Erkundungsverfahren, die Strömungsverhältnisse in den alluvialen Ablagerungen sowie lokale Hochwasserrisiken zu untersuchen.:Abstract i (Seitenzahl / page number) Acknowledgements iii Table of contents v List of tables viii List of figures ix Abbreviations and symbols xi 1 Introduction 1 1.1 Problem description 1 1.2 Riverbank filtration and its potential in India 2 1.3 Motivation 3 1.4 Aims 4 2 Bank filtration in context to India’s water resources 5 2.1 Water budget of India and the Ganga River catchment 5 2.1.1 Water budget 5 2.1.2 The Ganga River catchment 6 2.2 Problems of surface water abstraction for drinking water production 8 2.2.1 Effect of low surface flows on the quantity of raw water abstraction 8 2.2.2 Effect of the monsoon on conventional drinking water treatment plants using directly abstracted surface water 9 2.2.3 Quality of surface water 10 2.2.4 Treatment of directly abstracted surface water for drinking 11 2.3 Sustainability issues of groundwater abstraction 11 2.4 Drinking water consumption in India 12 2.5 Bank filtration for water supply 14 2.5.1 Geohydraulic, siting and design aspects of bank filtration systems 14 2.5.2 Water quality aspects 15 2.5.3 Water quality aspects for bank filtration in India 15 2.5.4 Risks to riverbank filtration sites from floods 16 2.6 Hypotheses favouring the use of bank filtration and the need for a concept to investigate potential RBF sites in India 17 3 Study areas 18 3.1 Choice of study areas 18 3.2 Case study site Haridwar 19 3.3 Case study site Patna 20 3.4 Case study site Srinagar in Uttarakhand 21 3.5 Hypotheses favouring RBF at the selected study sites 22 4 Methodology for the investigation of the case study sites 24 4.1 Overview of methodology for investigating the case-study sites 24 4.2 Investigations at the case study site of Haridwar 25 4.2.1 Initial site-assessment 25 4.2.2 Basic site-survey and establishing monitoring infrastructure 26 4.2.2.1 Identification of specific locations for monitoring wells 26 4.2.2.2 Geodetic survey and inventory of existing on-site infrastructure 26 4.2.2.3 Construction of exploratory wells 27 4.2.3 Determination of hydrogeological parameters 27 4.2.3.1 Sediment analyses 27 4.2.3.2 Determination of hydraulic conductivity by pump tests on large-diameter wells 29 4.2.4 Water level and stable isotope measurements 30 4.2.4.1 Water level 30 4.2.4.2 Stable isotopes 31 4.2.5 Water quality monitoring 31 4.2.5.1 Initial investigations, screening and formulation of monitoring concept 31 4.2.5.2 Comprehensive and regular monitoring 2011 - 2013 33 4.3 Investigations at the case study site of Patna 34 4.3.1 Initial site-assessment, basic-site survey and monitoring 34 4.3.2 Sampling for water quality and isotope analyses 35 4.4 Investigations at the case study site of Srinagar in Uttarakhand 35 4.4.1 Basic site-survey and establishing monitoring infrastructure 35 4.4.1.1 Identification of a specific location for a new RBF well 35 4.4.1.2 Construction of production and monitoring wells and exploratory boreholes 37 4.4.2 Determination of hydrogeological parameters and monitoring 38 4.4.2.1 Sediment analyses and determination of hydraulic conductivity of the aquifer 38 4.4.3 Water quality monitoring 40 4.5 Column experiments to determine the removal of bacteriological indicators under field conditions 40 5 Characterisation of the RBF system in Haridwar 42 5.1 Site and design aspects 42 5.1.1 Location of RBF wells 42 5.1.2 Design of RBF wells 44 5.1.3 Quantity of drinking water produced by RBF 45 5.2 Aquifer characterisation 47 5.3 Numerical groundwater flow model of RBF well field in Haridwar 49 5.3.1 Model set-up 49 5.3.2 Model calibration 50 5.4 Origin of water and mean portion of bank filtrate abstracted by RBF wells 52 5.5 Water quality 53 5.6 Analysis of presence of thermotolerant coliforms in RBF wells 56 5.7 Impact of regulated Upper Ganga Canal on RBF wells on Pant Dweep 58 5.8 Summary of case study site Haridwar 60 5.8.1 Aspects related to water quality 60 5.8.2 Benefit of groundwater flow modelling 60 6 Evaluation of the potential for RBF in Patna 62 6.1 Physiography and hydrogeology 62 6.1.1 South Ganga Plain 62 6.1.2 Patna 63 6.2 Ground and surface water levels 65 6.3 Ganga River morphology 66 6.4 Water quality 67 6.5 Numerical groundwater flow model of case study site Patna 68 6.5.1 Model geometry and initial conditions 68 6.5.2 Boundary conditions 69 6.5.3 Steady-state flow modelling 70 6.6 Isotope analyses 71 6.7 Summary of case study site Patna 71 7 Evaluation of the potential for RBF in Srinagar 73 7.1 Drinking water production and overview of geomorphology 73 7.2 RBF site characterisation 74 7.2.1 Aquifer geometry and material 74 7.2.2 Water levels 75 7.2.3 Hydraulic conductivity 76 7.3 Numerical groundwater flow model of case study site Srinagar 77 7.3.1 Model geometry and calibration 77 7.3.2 Origin of bank filtrate and travel time 78 7.4 Water quality 79 7.5 Discussion and summary of case study site Srinagar 81 8 Assessment of risks from floods and insufficient sanitary measures to RBF wells in Haridwar and Srinagar 82 8.1 Flood-risk identification from field investigations 82 8.1.1 Description of an extreme flood event in Haridwar 82 8.1.2 Description of an extreme flood event in Srinagar 82 8.1.3 Summary of identifiable risks 83 8.2 Assessment of risks to RBF wells 84 8.2.1 Design of wells and direct contamination 84 8.2.2 Field investigations on the removal of bacteriological indicators 85 8.2.3 Removal of coliforms under field conditions by column experiments 87 8.3 Proposals to mitigate risks at RBF sites Haridwar and Srinagar 89 8.3.1 Operational and technical aspects for a general risk management plan 89 8.3.2 Health aspects for a general risk management plan 89 8.3.3 Criteria for flood protection measures of RBF wells 90 8.3.4 Sanitary sealing of RBF wells 90 9 Application of initial site-assessment to investigate other RBF sites in India 92 9.1 Hydrogeology and system-design 92 9.1.1 RBF systems for small and large-scale urban water supply 92 9.1.2 “Koop” well RBF systems for small-scale rural water supply 98 9.2 Water quality parameters 98 9.2.1 Removal of bacteriological indicators by RBF 98 9.2.2 Removal of dissolved organic carbon and organic micropollutants by RBF 101 9.2.3 Inorganic parameters 102 10 Conclusions, recommendations and propagation of RBF 105 10.1 Hydrogeological and system-design considerations 105 10.2 Aspects for improvement of the concept for RBF site investigations 106 10.3 Policy and planning aspects for the propagation of RBF in India 108 References 110 Annexes 121 / Riverbank filtration or bank filtration (RBF / BF) is a potential alternative to the direct abstraction and conventional treatment of surface water by virtue of the effective removal of pathogens, turbidity, suspended particles and organic substances. A comprehensive overview of existing RBF systems in India has been compiled for the first time. To systematically select and investigate new and existing potential RBF sites in India, a methodological concept was developed and tested at three sites along the Ganga River. The four stages of the concept are: initial site-assessment, basic site-survey, monitoring of water quality and quantity parameters and determination of aquifer parameters and numerical groundwater flow modelling. Suitable geohydraulic conditions for RBF (hydraulic conductivity: 10E-4 to 10E-3 m/s, aquifer thickness: 11 to 20 m) exist along the upper course of the Ganga (Haridwar and Srinagar). Due to the presence of fine sediment layers beneath the river bed along the Ganga’s lower course (Patna), river-aquifer interaction occurs during increased shear stress on the riverbed in monsoon. The portion of bank filtrate abstracted by the wells in Haridwar was determined from isotope analyses (Oxygen 18) and electrical conductivity measurements of river and well water and is up to 90% for wells located on an island and between the river and a canal. The results were confirmed by groundwater flow modelling. A high removal of E. coli (3.5 to 4.4 Log10 units) and turbidity (>2 Log10 units) was observed at the investigated sites. An E. coli removal of 3 Log10 units was observed for short travel times of 2 days. Higher coliform counts in some wells occur due to contamination from landside groundwater. During floods and intense rainfall events, contamination of RBF wells from direct entry of flood water, seepage of surface runoff into the well through leaky covers, fissures in the well-heads / caissons and in-appropriately sealed well-bases has to be considered. The application of the adapted investigation concept to 15 other sites in India showed that the low DOC concentrations in river water (0.9 to 3.0 mg/L) and well-water (0.4 to 2.3 mg/L) are favourable for the application of RBF. A 50% decrease of the high (pre-monsoon) DOC concentration was observed during monsoon in Delhi and Mathura. For the exploration of new RBF sites in hilly / mountainous areas, investigations of the aquifer thickness using geophysical methods, subsurface flow conditions in the alluvial deposits and the risk from floods should be conducted.:Abstract i (Seitenzahl / page number) Acknowledgements iii Table of contents v List of tables viii List of figures ix Abbreviations and symbols xi 1 Introduction 1 1.1 Problem description 1 1.2 Riverbank filtration and its potential in India 2 1.3 Motivation 3 1.4 Aims 4 2 Bank filtration in context to India’s water resources 5 2.1 Water budget of India and the Ganga River catchment 5 2.1.1 Water budget 5 2.1.2 The Ganga River catchment 6 2.2 Problems of surface water abstraction for drinking water production 8 2.2.1 Effect of low surface flows on the quantity of raw water abstraction 8 2.2.2 Effect of the monsoon on conventional drinking water treatment plants using directly abstracted surface water 9 2.2.3 Quality of surface water 10 2.2.4 Treatment of directly abstracted surface water for drinking 11 2.3 Sustainability issues of groundwater abstraction 11 2.4 Drinking water consumption in India 12 2.5 Bank filtration for water supply 14 2.5.1 Geohydraulic, siting and design aspects of bank filtration systems 14 2.5.2 Water quality aspects 15 2.5.3 Water quality aspects for bank filtration in India 15 2.5.4 Risks to riverbank filtration sites from floods 16 2.6 Hypotheses favouring the use of bank filtration and the need for a concept to investigate potential RBF sites in India 17 3 Study areas 18 3.1 Choice of study areas 18 3.2 Case study site Haridwar 19 3.3 Case study site Patna 20 3.4 Case study site Srinagar in Uttarakhand 21 3.5 Hypotheses favouring RBF at the selected study sites 22 4 Methodology for the investigation of the case study sites 24 4.1 Overview of methodology for investigating the case-study sites 24 4.2 Investigations at the case study site of Haridwar 25 4.2.1 Initial site-assessment 25 4.2.2 Basic site-survey and establishing monitoring infrastructure 26 4.2.2.1 Identification of specific locations for monitoring wells 26 4.2.2.2 Geodetic survey and inventory of existing on-site infrastructure 26 4.2.2.3 Construction of exploratory wells 27 4.2.3 Determination of hydrogeological parameters 27 4.2.3.1 Sediment analyses 27 4.2.3.2 Determination of hydraulic conductivity by pump tests on large-diameter wells 29 4.2.4 Water level and stable isotope measurements 30 4.2.4.1 Water level 30 4.2.4.2 Stable isotopes 31 4.2.5 Water quality monitoring 31 4.2.5.1 Initial investigations, screening and formulation of monitoring concept 31 4.2.5.2 Comprehensive and regular monitoring 2011 - 2013 33 4.3 Investigations at the case study site of Patna 34 4.3.1 Initial site-assessment, basic-site survey and monitoring 34 4.3.2 Sampling for water quality and isotope analyses 35 4.4 Investigations at the case study site of Srinagar in Uttarakhand 35 4.4.1 Basic site-survey and establishing monitoring infrastructure 35 4.4.1.1 Identification of a specific location for a new RBF well 35 4.4.1.2 Construction of production and monitoring wells and exploratory boreholes 37 4.4.2 Determination of hydrogeological parameters and monitoring 38 4.4.2.1 Sediment analyses and determination of hydraulic conductivity of the aquifer 38 4.4.3 Water quality monitoring 40 4.5 Column experiments to determine the removal of bacteriological indicators under field conditions 40 5 Characterisation of the RBF system in Haridwar 42 5.1 Site and design aspects 42 5.1.1 Location of RBF wells 42 5.1.2 Design of RBF wells 44 5.1.3 Quantity of drinking water produced by RBF 45 5.2 Aquifer characterisation 47 5.3 Numerical groundwater flow model of RBF well field in Haridwar 49 5.3.1 Model set-up 49 5.3.2 Model calibration 50 5.4 Origin of water and mean portion of bank filtrate abstracted by RBF wells 52 5.5 Water quality 53 5.6 Analysis of presence of thermotolerant coliforms in RBF wells 56 5.7 Impact of regulated Upper Ganga Canal on RBF wells on Pant Dweep 58 5.8 Summary of case study site Haridwar 60 5.8.1 Aspects related to water quality 60 5.8.2 Benefit of groundwater flow modelling 60 6 Evaluation of the potential for RBF in Patna 62 6.1 Physiography and hydrogeology 62 6.1.1 South Ganga Plain 62 6.1.2 Patna 63 6.2 Ground and surface water levels 65 6.3 Ganga River morphology 66 6.4 Water quality 67 6.5 Numerical groundwater flow model of case study site Patna 68 6.5.1 Model geometry and initial conditions 68 6.5.2 Boundary conditions 69 6.5.3 Steady-state flow modelling 70 6.6 Isotope analyses 71 6.7 Summary of case study site Patna 71 7 Evaluation of the potential for RBF in Srinagar 73 7.1 Drinking water production and overview of geomorphology 73 7.2 RBF site characterisation 74 7.2.1 Aquifer geometry and material 74 7.2.2 Water levels 75 7.2.3 Hydraulic conductivity 76 7.3 Numerical groundwater flow model of case study site Srinagar 77 7.3.1 Model geometry and calibration 77 7.3.2 Origin of bank filtrate and travel time 78 7.4 Water quality 79 7.5 Discussion and summary of case study site Srinagar 81 8 Assessment of risks from floods and insufficient sanitary measures to RBF wells in Haridwar and Srinagar 82 8.1 Flood-risk identification from field investigations 82 8.1.1 Description of an extreme flood event in Haridwar 82 8.1.2 Description of an extreme flood event in Srinagar 82 8.1.3 Summary of identifiable risks 83 8.2 Assessment of risks to RBF wells 84 8.2.1 Design of wells and direct contamination 84 8.2.2 Field investigations on the removal of bacteriological indicators 85 8.2.3 Removal of coliforms under field conditions by column experiments 87 8.3 Proposals to mitigate risks at RBF sites Haridwar and Srinagar 89 8.3.1 Operational and technical aspects for a general risk management plan 89 8.3.2 Health aspects for a general risk management plan 89 8.3.3 Criteria for flood protection measures of RBF wells 90 8.3.4 Sanitary sealing of RBF wells 90 9 Application of initial site-assessment to investigate other RBF sites in India 92 9.1 Hydrogeology and system-design 92 9.1.1 RBF systems for small and large-scale urban water supply 92 9.1.2 “Koop” well RBF systems for small-scale rural water supply 98 9.2 Water quality parameters 98 9.2.1 Removal of bacteriological indicators by RBF 98 9.2.2 Removal of dissolved organic carbon and organic micropollutants by RBF 101 9.2.3 Inorganic parameters 102 10 Conclusions, recommendations and propagation of RBF 105 10.1 Hydrogeological and system-design considerations 105 10.2 Aspects for improvement of the concept for RBF site investigations 106 10.3 Policy and planning aspects for the propagation of RBF in India 108 References 110 Annexes 121