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The book embodies the groundwater issues and challenges in India focusing its sustainable use. It is a compilation of papers presented by the eminent experts from Government departments, academia, research institutes, NGOs and stakeholders who assembled at Kurukshetra on 21st August, 2015 in the event of Bhujal Manthan or “Churning of Groundwater” organized for the first time by Ministry of Water Resources, River Development and Ganga Rejuvenation, the apex Ministry of Water Resource under Government of India.

India, as a country, is the highest groundwater extractor in the world. Its service towards attaining the food and clean drinking water security is well documented. This volume addresses the issues of aquifer characterization, groundwater contamination, groundwater resource availability and its sustainable management through community participation in pan-India scenario. This book provides a unique opportunity for its readers to understand groundwater domain in India in its entire gamut. The papers included in the volume were selected carefully from the presentations made in the following four broad topics during the Manthan; (i) groundwater quality, (ii) conjunctive use of surface and groundwater, (iii) management intervention and sustainable use of this resource, and (iv) groundwater problems and application of various techniques.

The book contains 20 papers including an introductory chapter by the editors. The content of the book is enriched by contributions from eminent researchers and activists in groundwater domain, like Prof. Tushar Shah, Prof. Himanshu Kulkarni, Dr. D. K. Chadha, Dr. Bharat Sharma and others. The recommendations in the individual papers are of immense significance for keeping the groundwater of the country clean and sustainable. The volume will help the readers to understand the groundwater issues of the country and also assist policy makers to prepare strategies for its better governance and management with environmentally sustainable ways.

Inhaltsverzeichnis

Frontmatter

Groundwater Resources and Sustainable Management Issues in India

Abstract
Groundwater is a critical component for socioeconomic development in India. The country exhibits wide spectrum on geology, climatic condition, and terrain, which is reflected in considerable variation in groundwater occurrence and movement. In addition, excessive withdrawal, in comparison with its annual replenishment, has created overexploitation of this precious natural resource, obliterating natural groundwater regime in large areas of the country. Besides, in many parts, the groundwater is contaminated both geogenically and anthropogenically. India as a country has established himself as the largest groundwater extractor in the world. The looming issues of overexploitation and deteriorating quality call for sustainable management of groundwater resource in long-term perspective. With the preamble on the review of the hydrogeology of the country, this paper summarizes 20 contributions that have been included in this volume. The papers are rich in their content and present a wide array of groundwater issues of the country, ranging from quality, conjunctive use of surface and groundwater, artificial recharge, community participation in its management, urban hydrogeology, coastal aquifer dynamics, mining hydrogeology, and application of state-of-the-art investigation techniques in groundwater survey and management. The aroma of the volume will enrich which are directly or indirectly linked with groundwater resource management of the country.
Dipankar Saha, Sanjay Marwaha, Arunangshu Mukherjee

Fluoride Contamination in Groundwater: A Pilot Study on Dug Well Recharge System for In situ Mitigation

Abstract
Dissolved ions concentration in groundwater beyond the recommended limits is a major problem as they make the water unsuitable for drinking purpose. Fluorine commonly found in certain rocks is released into groundwater due to the processes of rock–water interaction. This leads to increase in the concentration of fluoride in groundwater which is a major problem in several parts of the world including India. Presence of fluoride beyond the prescribed limits causes health problems to humans due to prolonged consumption of water, which is common in many parts of India. Dental and skeletal fluorosis is observed due to prolonged drinking of water with fluoride concentration above 1.5 mg/l. The objective of the study is to know how fluoride get released from the host rock and spot out suitable location for installing a dug well recharge system to decrease the fluoride concentration in groundwater. Several methodologies exist for in situ or exsitu removal of fluoride from groundwater. Exsitu methods can be enforced at community level or even at household level for the reduction of fluoride before its consumption, through ion exchange, reverse osmosis, adsorption, electrodialysis, coagulation, Nalgonda technique, electrodialysis, coagulation, precipitation, etc. Even artificial recharging structures can also be built in suitable location for diluting fluorite concentration in groundwater. Rainwater harvesting is also found effective to reduce the fluoride concentration of groundwater in existing wells. A pilot study was carried out by construction of a dug well recharge system in Dharmapuri district, Tamil Nadu, India. The study successfully demonstrated the applicability of dug well recharge system at a carefully selected site based on the systematic long-term hydrogeochemical studies to solve the problem of fluoride contamination affecting millions of rural people.
L. Elango, G. Jagadeshan

Deciphering Freshwater/Saline Water Interface in and Around Northern Chennai Region, Southern India

Abstract
Chennai, a city of almost seven million people, is one of the most water-stressed cities of India. While the population keeps skyrocketing, the volume of water available for them is dwindling. Scarcity intensifies conflict between Chennai and its peri-urban areas, which warrants urgent attention. The city receives about 985 million litres a day (mld) against the demand of 1200 mld. The present demand of 1200 mld includes the drinking water requirement for the city and its urban agglomerations that is 950 mld and the industrial demand of 250 mld. This demand is projected to increase to 2100 mld by 2031. Presently, the demand is met from the five freshwater reservoirs besides groundwater is pumped from 6 well fields in the inter-fluve area of the Araniyar and Korattalaiyar rivers. In the last decade, 3 well fields had to be abandoned due to seawater intrusion. In the dry months, seawater intrusion is observed 16 km inland, and after the monsoon, the seawater intrusion moves seaward side and is observed 14 km inland. There is an urgent need to monitor and regulate the fresh groundwater resource of the region. This paper describes the exact hydrological frame walk of the area. Rainwater harvesting and artificial recharge at apt locations in the Korattalaiyar River Plain so that the saline and fresh water interface is pushed further towards the seaward side.
M. Senthilkumar, D. Gnanasundar, E. Sampath Kumar

Geogenic Fluoride Contamination in Two Diverse Geological Settings in West Bengal

Abstract
Fluoride contamination in groundwater has been studied in two important geological settings of West Bengal, viz. (i) alluvium of Rampurhat–Nalhati area of Birbhum district, and (ii) consolidated formation of Barabazar block of Purulia district. Rampurhat–Nalhati area in Birbhum district is located in ‘basin margin’ area represented by Tertiary sediments overlain by Quaternary deposits. A two aquifer system exists in the area: (i) shallow aquifer in the Pleistocene Older Alluvium in Quaternaries, and (ii) deeper aquifer within the Tertiary sediments. The shallow aquifer has high groundwater potentiality with low fluoride content, while the deeper aquifer system is characterized by comparatively low yield and high fluoride concentration. Maximum concentration of fluoride of 10.7 mg/L has been encountered at Junudpur in Birbhum district. At places, only one continuous aquifer system exists where the groundwater potentiality is high with low fluoride content. The fluoride content of groundwater has, in general, an inverse relationship with calcium and magnesium content and positive relationship with sodium concentration. Barabazar block in Purulia district is situated in the eastern fringe of Chhotanagpur Gneissic Complex, occupied mostly by meta-sedimentaries and a few thin linear patches of alluvium along narrow courses of stream. Groundwater prospect is better in northern parts underlain by gneissic rocks than in the south, which is mainly underlain by phyllites and schists. No relationship could be established between the fluoride content of groundwater with the concentrations of bicarbonate, calcium and sodium. Groundwater is generally potable, except at places near ‘south shear zone’, where groundwater with high concentration of fluoride and iron has been encountered. The concentration of fluoride increases with depth as well as in proximity to shear zone. In both cases, fluoride concentration in groundwater increases with depth.
S. Brahma

Petro-Geochemical Analysis and Their Correlation for Genesis of Fluoride Contamination in Groundwater of District Sonbhadra, U.P., India

Abstract
In many parts of India, high concentration of fluoride in drinking water has been causing severe health problems in human, such as dental and skeletal fluorosis. The present study has been aimed to assess the role of hydrogeological characteristics on fluoride contamination of groundwater. This includes the monitoring of parameters such as lithological compositions, groundwater level behavior, and different chemical parameters to understand their impact on fluoride concentration in the study area of Sonbhadra district, U.P. Chemical parameters such as pH, F, EC, TDS, chloride, total hardness, alkalinity, phosphate, Ca2+, Mg2+, Na+, and K+ have been determined. A petrological study of rocks reveals that mainly granite, granite gneiss, and pegmatite types of rocks are found in area. In general, high fluoride content has been observed in shallow aquifer due to erosion of rock. Therefore, the most dominant reason for leaching of fluoride in groundwater is due to the weathering of various fluoride-bearing minerals in the area.
H. K. Pandey, S. K. Srivastava, Prashant Pandey

Hydrochemical Evaluation of Fluoride-Rich Groundwater in Cherlapalli Watershed, a Fluorosis Endemic Area, Nalgonda District, Telangana State

Abstract
Nalgonda District is widely known as one of the fluorosis endemic districts of India. Groundwater quality from Cherlapalli watershed, Nalgonda District, is evaluated with reference to fluoride. In the present study, concentration of fluoride is reported as high as 7.1 mg/L, while NO3 reaches up to 490 mg/L. Higher F concentrations are detected in highly weathered and fractured zones in structurally controlled central part of the area. Vertical variation in fluoride concentrations is observed down to 120 m depth, indicating local geological influence. F and Ca2+ show moderate degree of negative correlation, indicating F enrichment by removal of Ca2+ during rock-water interaction. Positive correlation between Na+ and F and pH and F reveals that Na+ is released into groundwater under alkaline conditions. Groundwater is mainly of Na–Mg–HCO3- and Na–HCO3 types. It is recommended that for drinking use surface water be blended with groundwater in fluoride-affected areas under the proposed Water Grid Project by local Government. Artificial recharge measures through percolation tanks and check dams are recommended in the central part where thick de-saturated weathered zone is available. De-silting of existing tanks under the ongoing Govt.-sponsored Mission Kakatiya may be taken on priority basis in the area.
Pandith Madhnure, P. N. Rao, K. M. Prasad, A. D. Rao, J. S. Kumar

Uranium Contamination of Groundwater in Southwest Parts of Punjab State, India, with Special Reference to Role of Basement Granite

Abstract
The state of Punjab is known for potential aquifer system and also experiencing heavy groundwater extraction mainly to cater the irrigation sector from the shallow aquifers (<50 m depth). Uranium concentration in the groundwater from shallow tubewells (<50 m depth) ranges from 1.78 to 261 µg/L. Uranium concentration shows spatial variations even within a short distance of 200 m. In majority of samples, uranium concentration exceeds the permissible limit of 15 µg/L prescribed by WHO (2004) and 60 µg/L prescribed by AERB, DAE (2004). Most workers link the presence of uranium in groundwater to basement granite. The results of uranium analysis of basement granite sample collected earlier from Phulka (29° 29′; 75° 08′) during exploratory drilling carried out under UNDP-CGWB project reveal a normal concentration of 3.686 µg/g. Further, the granite core sample shows negligible (0.01 mR/h) radioactivity. In addition, granitic basement occurring at the depth of 242 m or more at other places could not have contributed uranium to groundwater occurring at shallow depth (up to 50 m). Uranium concentration in sediments/soils was found to range between 1 and 3 µg/g. Mobilization of uranium from sediments/soils under favorable geochemical conditions seems to be the possible explanation for uranium contamination in groundwater.
K. P. Singh, Naval Kishore, Naresh Tuli, R. S. Loyal, Mandeep Kaur, Jasbir Kaur Taak

Conjunctive Use of Surface and Groundwater in Efficient Manner

Abstract
Conjunctive use of groundwater and surface water is being adapted in many countries to enhance the intensity of irrigation and host at often benefits like cope with the water logging and salinity problems in canal irrigated areas, blending of water reduce the contamination load etc. In India, a number of scientific studies have been conducted which conclusively proved its importance and benefits, but the implementation of this technology has been overlooked because of apathy at various levels. The implementation of conjunctive use program has to be considered now seriously if we really mean “each drop of water counts” for food security in views of the climate change scenario. The chapter presents details of the different aspects of the conjunctive use with the assertion that institutional arrangements and action plan be made for taking up the projects for which detailed hydrogeological studies have already been completed and found favorable for its application.
D. K. Chadha

Efficient Conjunctive Use of Surface and Groundwater Can Prevent Seasonal Death of Non-Glacial Linked Rivers in Groundwater Stressed Areas

Abstract
The surface and groundwater system is an interdependent system. In the case of alluvial plains, they are best manifested by the relationship between a river and groundwater system. This relationship is vibrant and dynamic in rain-fed rivers or the non-glacial linked rivers. It has been typically observed that many a case such rivers originate from lesser elevation and in downstream stretches; during summers, their flow is maintained by groundwater contribution. In groundwater stressed regions, often these rivers get disconnected from aquifer. Thus there could be different levels of stream-aquifer interaction during monsoon and non monsoon seasons. In this context, the article examines effect of long-term groundwater abstraction on such river flows in a conceptual framework. It also proposes efficient conjunctive use of surface and groundwater to prevent death of such rivers.
Shashank Shekhar, Suman Kumar, Rajiv Sinha, Sanjeev Gupta, Alexander Densmore, S. P. Rai, Manoranjan Kumar, Ajit Singh, Wout Van Dijk, Sunil Joshi, Philipa Mason, Dewashish Kumar

Specific Yield of Unconfined Aquifers in Revisiting Efficiency of Groundwater Usage in Agricultural Systems

Abstract
Groundwater has been the backbone of water for agriculture in India. Millions of farmers depend on groundwater for sustaining their agricultural livelihood. Any discussion on groundwater would be incomplete without taking into consideration the resource unit i.e. aquifers. Aquifer storage capacity is not necessarily reflected in discussions on water use efficiency. Efficiency estimation in agricultural systems has centred on a crop-per-drop approach. We take up three traditional approaches to efficiency in the context of two case studies from western Maharashtra which are part of shallow unconfined Deccan basalt aquifer systems, viz. Pabal and Randullabad. We compare the efficiencies of these two aquifers and propose a more comprehensive methodology to address efficiency in groundwater-based agricultural systems taking into consideration the characteristics of aquifers, mainly the specific yield. Such an efficiency index is useful in gauging specific impacts from initiatives that include supply and demand-side interventions.
Himanshu Kulkarni, Uma Aslekar, Dhaval Joshi

Toward a Managed Aquifer Recharge Strategy for Gujarat, India: An Economist’s Dialogue with Hydro-geologists

Abstract
Gujarat state in Western India exemplifies all challenges of an agrarian economy founded on groundwater over-exploitation sustained over decades by perverse energy subsidies. Major consequences are secular decline in groundwater levels, deterioration of groundwater quality, rising energy cost of pumping, soaring carbon footprint of agriculture and growing financial burden of energy subsidies. In 2009, Government of Gujarat asked the present author, an economist, to chair a Taskforce of senior hydro-geologists and civil engineers to develop and recommend a managed aquifer recharge (MAR) strategy for the state. This chapter summarizes the recommended strategy and its underlying logic. It also describes the imperfect fusion of socioeconomic and hydro-geological perspectives that occurred in course of the working of the Taskforce and highlights the need for transdisciplinary perspectives on groundwater governance.
Tushaar Shah

Co-solving Groundwater Depletion and Seasonal Flooding Through an Innovative Managed Aquifer Recharge Approach: Converting Pilot to a Regional Solution in the Ram Ganga Sub-basin

Abstract
Climate induced extreme events such as floods and droughts are often disastrous in incidences and affects Indian economy often. Low per capita surface water storage (225 m3/capita1), few sites for additional storages facilities and depleting groundwater aquifers reduce the resilience of the communities to alleviate the day-to-day short age and larger seasonal shocks. India has a long history of storing and recharging runoff waters through community participation. Ongoing such programs are focused on drought-prone or socio-economically weak areas and exclude the flood prone zones. The present study aims to improve the groundwater resources availability through diverting flows from rivers or canals at times when these flows pose flood risk and recharging the groundwater through suitable artificial recharge structures. This method addresses the issue of groundwater depletion as well as reducing the flood risks. A geo-hydrological analysis in spatial platform using data available in public domain and detailed ground survey, a site was identified in Jiwai Jadid village of Milk Block of Rampur district of Uttar Pradesh, India. A community owned pond was retrofitted with recharge wells and associated infrastructure to draw excess monsoon water from a nearby flood-prone river. The preliminary results show a positive impact on groundwater table and water quality. However, to achieve the full benefit of the method it is required to implement it in larger scale. Ongoing government programs that are focused on livelihood improvement and natural resources management are the best options to scale up such effect in regional scale.
Prasun K. Gangopadhyay, Bharat R. Sharma, Paul Pavelic

Impact Assessment of Demonstrative Project on Artificial Recharge to Groundwater in Gangavalli Block, Salem District, Tamil Nadu

Abstract
A total of 41 nos of artificial recharge structures (ARS) were constructed in Gangavalli block, Salem District, Tamil Nadu. The area is located in the central parts of the state and the block is marked with groundwater over exploitation. The project was executed to demonstrate the efficacy of the ARS in the aquifer type. The contributing aquifers are made up of weathered zone and underlying fractures within granite gneiss and charnockites. The area is depending on groundwater resources for all utilisation and the abstraction structures are dug well and borewell. The efficacy of the ARS constructed in the area has been assessed by studying its impact on hydro-geological scenario and agricultural practices.
A. Subburaj, E. Sampath Kumar, S. Suresh, V. Elanchelian, K. Rajarajan

Soil Infiltration Test in Hard Rock Areas—A Case Study

Abstract
The study carried out in Ankasandra watershed covering on area of 375 km2, falling in parts of Tiptur and C.N. Halli taluks of Tumkur district, Karnataka. Three major rock types identified in the area are gneisses, schists and granites belong to Archaean age. Groundwater is being extracted through borewells tapping fractures in depth ranges of 10–249 m below ground level. Over a period of time, due to increase in number of borewells and increasing groundwater extraction, the water level has gone down to more than 100 m bgl at certain location. The soil type in the area is fine red soils followed by clayey skeletal and loamy skeletal soils, and the rainfall is the main source of recharge. Twenty infiltration tests were conducted at various soil types using double-ring infiltrometer to understand the infiltration characteristics. The results of studies revealed that highest infiltration rates were observed at Madapurahattithanda, Kaval and Siddaramanagara sites characterised by sandy roils and lowest rates were noticed at Halkurike, Bommanahalli, Bhairanayakanahalli, Kuppur and Sasalu sites located on tank beds, pointing towards, need for desiltation of the tanks so that the tanks contribute to recharge also.
S. S. Vittala, G. R. C. Reddy, K. R. Sooryanarayana, G. Sudarshan

Peoples’ Participation for Sustainable Groundwater Management

Abstract
India is the largest user of groundwater in the world. Over 85% of rural domestic water, around 48% of urban domestic water, and 60–70% of agriculture water are groundwater dependent. This has resulted in the overexploitation and acute depletion of the resource in many parts of the country. Despite the manifold short- and long-term consequences of such dependence on a fast depleting and critical resource, India has made little headway in its regulation or conservation. While groundwater exhibits the qualities of a classic common pool resource—those of subtractability and excludability, in reality, it has largely been treated as private property. Much of the problem lies in the juxtaposition between the public and common pool nature of groundwater and its rampant private, atomized, and unregulated extraction. As the volume diminishes and quality deteriorates, lack of regulation and appropriate management can lead to both inter- and intra-use conflicts with considerable political and socio-economic impacts. Therefore, in order to conserve this resource it is imperative to shift away from a paradigm of private groundwater development to a more sound system of groundwater management. This paper argues that despite the relative invisibility of groundwater and the complexities that surround its governance, decentralized management options offer better solutions for long-term sustainability of the resource and ensure social equity. Firstly, it argues for a hydrogeological foundation for groundwater management. Secondly, given the decentralized nature of aquifers, community participation is essential for the sustainability of this resource. Finally, it highlights the urgent need for policy initiatives that recognize the common pool nature of groundwater and facilitate bottom-up innovations that reflect the local geological and socio-economic specificities of the resource Sengupta 2015.
Bishwadeep Ghose, Harshvardhan Dhawan, Himanshu Kulkarni, Uma Aslekar, Siddharth Patil, M. V. Ramachandrudu, Bakkareddy Cheela, Yogesh Jadeja, Brijen Thankar, Ravi Chopra, Anil Gautam, Eklavya Prasad

Geospatial Analysis of Recharge of Groundwater and Irrigation Draft from Different Aquifer Systems of Rajasthan, India

Abstract
Groundwater over-exploitation for agricultural crops caused adverse impact on the sustainability of the resources of Rajasthan. Western arid to central semi-arid regions of the state shows a large spital variation in annual rainfall. The study of groundwater elevation zones during pre-monsoon, post-monsoon, and post winter irrigation (January to March) seasons shows a steady declining of groundwater level of places such as Osian (1.93 m/year) and Piprali (1.50 m/year) which is attributed to excessive groundwater draft due to irrigation in Rabi season. It has been predicted that most of the tube wells in Osian and Piprali may get dry completely by 2048 and 2068, respectively. However, during the same period Khamnor area shows rise in groundwater level at the rate of 1.19 m/year. This variation in groundwater level is attributed to the nature of different aquifer systems viz. alluvium in Piprali, sandstone in Osian, and gneisses in Khamnor area. Implementation of water harvesting structures shows significant improvement in recharge of groundwater in Osian and Khamnor area underlain by hard rock aquifer system. Geospatial analysis of recharge and draft from groundwater during 2008–2009, 2010–2011, and 2011–2012 shows significant changes due to rise and fall in groundwater levels. Over-exploitation of groundwater has developed a non-equilibrium stage between recharge and irrigation draft. In contrary, a positive impact on groundwater recharge in Khamnor area is evident due to higher rainfall and hard rock aquifer with secondary porosity (joints/fractures). Unless preventive measures are taken, the gap between groundwater recharge and draft will increase many folds in future.
Bidyut Kumar Bhadra, Rakesh Paliwal, S. Srinivasa Rao

Evaluation of Water Level Behavior in Coal-Mining Area, Adjacent Township, and District Areas of Jharkhand State, India

Abstract
The present paper deals with groundwater level behavior in the coal-mining areas and also in the adjacent township areas of the Jharkhand State. Thickness of saturated zone and the water level behavior depend on spatiotemporal and hydrogeological factors such as soil type, geomorphology, geological formations, rain fall pattern and distribution, and groundwater exploitation. The groundwater regime largely follows the topographical features in the area. In the mining areas, i.e., the East Bokaro, Jharia, and West Bokaro coalfield the water level ranges from 1.64 to 11.20, 3.05 to 11.10, and 1.8 to 16.12 mbgl, respectively, during pre-monsoon period while during post-monsoon it ranges from 1.36 to 10.80, 1.4 to 7.5, and 0.3 to 10.7 mbgl, respectively. The average seasonal water table fluctuation in the area is 2.60, 0.68, and 3.2 mbgl, respectively. Whereas in the adjacent township areas, the average water level during pre-monsoon is 6.99, 6.29, and 5.21 mbgl, respectively, while during post-monsoon the value are 2.46, 6.29, and 3.40 mbgl, respectively. It has been found that mining and industrial activities in some specific locations are impacting both shallow as well as deep aquifer indicating that sustainable groundwater management is urgently needed incorporating geological complexities and aquifer depositions in the area. Artificial recharge and protection of impacted aquifers are the key components of the management plan.
Prasoon Kumar Singh, Ashwani Kumar Tiwari, Poornima Verma

Modelling the Potential Impact of Small-Scale Pumping Near Future Water Supply Wells in a Stressed Aquifer in South Western Bengal Basin on Groundwater Flow

Abstract
This paper highlights the importance and effectiveness of groundwater modelling to water managers to protect stressed aquifer systems and to address conflicting interests and requirements in their decision making process. The study area is located in south western Bengal Basin which is a part of the lower deltaic plain of the River Ganga and lies on the eastern side of the River Hugli, a distributory of River Ganga. The aquifer is sandwiched between two aquitards and is semi-confined in nature. Steady-state model results indicate that groundwater pumping in a proposed housing complex in Kolkata city located just outside the eastern margin of East Kolkata Wetlands (EKW) far outweigh the topographic and geologic controls of the unperturbed groundwater flow system and shifts recharge areas towards the pumping centres. A small part of the groundwater is also recharged from far areas in the south and southwest. Drawdowns due to present and future pumping in the project area extend over a large area which results in interference effect in wells outside the project area. Therefore, part of the city wells will experience an additional fall in the piezometric head. The simulation results indicate that the aquifer is already stressed and therefore it may not be wise to abstract groundwater further. The required water for the housing complex may be obtained from other sources. If other sources of water are not available then as the last resort groundwater may be developed. In such case further groundwater development by wells of high yield around the project area should be avoided. It is also imperative that steps should be taken to artificially recharge the aquifer by roof top rainwater harvesting.
P. K. Sikdar, Paulami Sahu

Hydrodynamics of Groundwater Flow in the Arsenic-Affected Areas of the Gangetic West Bengal, India

Abstract
Hydrostratigraphy and groundwater flow in a ~21,000 km2 area of the arsenic-contaminated districts of West Bengal [Murshidabad, Nadia, North 24 Parganas and South 24 Parganas (including Calcutta)], India, have been delineated. Based on 143 lithologs, a regional hydrostratigraphic model has been developed to a depth of 300 m below mean sea level. Lithologic interpolations that were done manually and by computer models (resolution: 1000 m × 1000 m × 2 m) demonstrate a near-continuous, unconfined to semi-confined aquifer dominated by sand underlain by a thick clay aquitard. The aquifer thickens toward basin center in Bangladesh, toward south and east. Toward the Bay of Bengal, at the southern boundary, several heterogeneous aquitard layers of clay sub-divide the primary aquifer, into several deeper, regionally-discontinuous but laterally-connected, confined to semi-confined aquifers. Eight 21-layer regional groundwater models are based on observed topography and hydrostratigraphy. Groundwater flows were simulated in the pre-monsoon, monsoon and post-monsoon seasons with presence (2001) and absence (pre-1970s) of irrigation pumping and projected pumping for pre-monsoon seasons of 2011 and 2021. Modeling results indicate topographically dominated, seasonally variable, continuos regional-scale groundwater flow, which have been largely distorted by pumping. Groundwater flow is predominantly in the upper ~100 m of the aquifer but occurs to a depth of ~200 m.
Abhijit Mukherjee

Recording High Natural Gamma Radiations in Fluoride-Prone Area of Shivpuri District, Madhya Pradesh

Abstract
The occurrence of fluoride in groundwater is a major issue for aquifer-based drinking water supply. Many parts in state of Madhya Pradesh exhibit elevated fluoride content in groundwater. Present study has been conducted in Shivpuri district, underlain by granite and gneiss with some patches of recent alluvium. Ten boreholes have been drilled, and out of them, seven boreholes have been logged geophysically for natural gamma count. Chemical analyses of groundwater samples from the drilled wells have maximum fluoride content up to 5 mg/L. The natural gamma loggings conducted into the boreholes down to the depth of 200 mbgl have recorded 100–1600 cps for various lithological units encountered into the boreholes. It has been observed that water-rich fractures encountered in some of the boreholes with higher fluoride concentration is also showing higher range of natural gamma counts. Fluorite as a mineral in granites is considered as marker horizons for prospecting of radioactive minerals. Fluorite-bearing rocks releases fluoride in groundwater as well as related to high natural gamma radiation in the study area. The paper address geogenic groundwater quality problem of fluoride, associated with radioactive radiations in parts of Shivpuri district, Madhya Pradesh.
Subhash C. Singh, Rakesh Singh, Parvinder Singh

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