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Arsenic in groundwater above 0.05 mg/l was found in 61 out of the total of 64 districts, and 433 out of the total of the 496 thanas in Bangladesh. Groundwater arsenic contamination in Bangladesh is reported to be the biggest arsenic calamity in the world in terms of affected population. Water in around 65% of the areas of Bangladesh contain iron in excess of 2 mg/l, and arsenic has been found to co-exist with iron in many situations. Thus the presently used iron removal plants that operate on the principle of aerating ferrous iron to convert it into ferric iron for precipitation can be a cost-effective solution for treating both iron and arsenic together in the context of Bangladesh. This study investigates the efficiency of 60 arsenic and iron removal plants (AIRPS) presently operating in different geo-hydrological conditions of Bangladesh. [ABSTRACT FROM AUTHOR]

Groundwater reservoirs play an important role in regional water volume balance. In order to ensure the efficiency of a groundwater reservoir and obtain its maximum value, it is necessary to figure out its characteristics, such as minimum water level, normal water level, and maximum water level. The characteristics not only determined the storage capacity but also influenced the water allocation and utilization. Therefore, this paper took a groundwater reservoir built in an alluvial fan as an example to assess its storage capacity and the influence on water dynamic control. The alluvial fan was located in the front of Lao River, where there were an alluvial-diluvial fan, groundwater storage space, and natural impervious boundary. Therefore, it was an ideal place for constructing a groundwater reservoir. Through theoretical analysis and numerical simulation, the storage capacity was determined, and the influence of groundwater reservoir characteristics on water dynamic control was analyzed. On this basis, the water-supply method in the research area was confirmed. This paper will present a new method for repairing the groundwater system and protecting the ecological environment.

Surface water contamination has emerged as an area of major concern in rapidly growing cities in the Global South, including and especially in the Indian megacity context. We argue here that nallahs (open drainage channels in Indian megacities) should be more widely recognized as a potential locus of intervention. These combined stormwater and wastewater networks offer opportunities for flexible, frugal and inclusive retrofits to improve surface and groundwater quality. We propose and define the concept of provisional green infrastructure (PGI) as a speculative innovation typology describing in-stream interventions. We argue that PGI should be employed as a shared boundary concept guiding transdisciplinary action and research within the highly unpredictable, space-constrained, and contaminated watersheds. Citing case studies throughout the region and ongoing research in the city of Bangalore, we demonstrate in-stream modifications may be capable of achieving significant improvement in the quality of urban wastewater and may play a complementary role in closing persistent capacity gaps in the operation of both centralized and decentralized treatment practices within megacities. Anticipating the larger diffusion of PGI practices across the region by various early adopters and non-state actors, we suggest a cogent research agenda focused on identifying various generalizable 'upscaling' opportunities for deploying in-stream interventions across various organizational and spatial domains.

Study of the vulnerability of water resources contributing to consumer health in the inter-tropical zone. The aim of this paper is to present the state of the art on the protection of water resources in the inter-tropical zone in order to identify gaps in knowledge that improve drinking water supply. To achieve this, a documentary search online was carried out to assess the progression of work over time. What emerges from this literature review is that the method for assessing intrinsic and specific vulnerability in bedrock areas is practically non-existent. A discrepancy exists and reflects the difference in a coincidence of the level of vulnerability when several methods of determining vulnerability are used in the same study site. The issue of validation is still problematic, as it lies in the fact that a property that is not precisely defined cannot be unambiguously deduced from the measured quantity. The characterisation of specific pollutants and their propagation in the saturated or groundwater zone are not taken into account. All the different components of the water cycle are not always taken into account during a groundwater vulnerability study, yet each water resource is part of a closely related component of the water cycle. HIGHLIGHTS The aim of this paper is to present the state of the art on the protection of groundwater that improve drinking water supply.; Several indices have been identified in the literature.; However, these indices reveal that groundwater vulnerability assessment procedures are not well understood, are poorly used, and remain a challenge for underdeveloped countries.; There is an urgent need to apply effective corrections to the methods of protecting water resources in the intertropical zone for drinking water supply.;

Microplastics (MPs) are widespread in aquatic and soil environments. This study targets the issue of MPs' transfer from soil to groundwater. Scientific papers were collected and analyzed using a text-mining approach that classifies text segments. This allowed the identification of four research topics and the organization of the results into a summarizing table. Those four topics are sources of groundwater MPs, main types of MPs (physico-chemical properties, polymer units, shapes, and size), human exposure (mainly drinking water), and potential environmental and human effects. Compared to the research of MP on aquatic or soil compartments, scientific data on MP in groundwater are less substantial. Current results show a divergence due to differences in context (alluvial aquifer, fractured rock aquifer, karst aquifer, etc), collecting, sampling, and analytical methods. This divergence requires further research with standardized analytic protocols and reference materials. The associated research gaps were identified by using the same approach. The following five topics emerged: (1) the transfer of MPs from soil to underground, (2) the contribution of groundwater to drinking water microplastic pollution, (3) the interaction with other contaminants, (4) the human and environmental effects, and (5) the protective and remediation solutions. [ABSTRACT FROM AUTHOR]

Fluoride has both beneficial and detrimental effects on human health. Concentrations of fluoride less than 1.0 mg/L in ingested water are beneficial for the rate of tooth decay, especially in children. The aims of the paper are as follows: (i) to monitor fluoride concentrations in drinking water samples (well water and tap water from the rural district of Valea Râmnicului, Romania); (ii) to study and select the optimal buffer solution and the optimal volume used in the analyses and (iii) to validate the potentiometric method for determining fluoride ions with a selective ion electrode. The values of fluoride ion concentrations in the groundwater samples and in tap water varied from 0.01 to 0.138 mg/L. The values for the hazard quotient for the studied samples varied from 0.01 to 0.13. [ABSTRACT FROM AUTHOR]

This paper aimed to determine the grey water footprint (GWF) of groundwater resources. The effect of groundwater recharge on grey water footprint was investigated in Southeastern Turkey. In this paper, GWF has been monitored in October and March in terms of nitrate and arsenic concentrations for ten observation wells in the Harran Plain. In this study, a new approach was developed based on the GWF to determine the nitrate and arsenic pollution of groundwater. GWF of coagulation-flocculation and biochar adsorption processes were calculated and benchmarked with each other. In the second stage of the study, the effect of groundwater recharge using reclaimed municipal wastewater on GWF was investigated applying Monte Carlo simulation. The results revealed that nitrate led to higher GWF. According to the results, biochar application could reduce the GWF. Total reduction of GWF would be approximately 64.3% if groundwater recharge using reclaimed wastewater is applied. HIGHLIGHT The novelty of this study is that a new estimation model has been adapted for grey water footprint of groundwater resources. The other originality of this work is biochar application for groundwater treatment. Biochar application was carried out to treat groundwater in order to observe the GWF. Urfa Isot pepper, which is a traditional crop of Turkey, was used to generate biochar with slow pyrolysis.;

This paper investigates the effect of phosphorus on nitrogen migration and transformation during the sewage purification processes in deep subsurface wastewater infiltration systems. Good performance was achieved with a hydraulic loading rate of 0.1 m 3 /m 2 ·d, indicating that the effluent water quality could meet the primary grade A values as put forth by the 'Cities Sewage Treatment Plant Pollutant Discharge Standard' (GB18918-2002). In addition, the results of three inflow total phosphorus (TP) concentrations (5 mg L -1 , 15 mg L -1 , and 30 mg L -1 ) indicated that high-levels of phosphorus were more advantageous in regards to improving the activity of denitrifying bacteria in soil and strengthening the effect of nitrogen removal, suggesting that the effluent total nitrogen (TN) concentration could meet the primary grade A standard (TN ≤ 15 mg L -1 ). It was further observed that soil depth was less crucial when inflow TP concentrations were higher. Therefore, the results indicated that inflow phosphorus concentrations could greatly influence nitrogen migration and transformation in deep subsurface wastewater infiltration systems.

The conjunctive use of groundwater and surface water (GW-SW) resources has grown worldwide. Optimal conjunctive water use can be planned by coupling hydrologic models for the simulation of water systems with optimization techniques for improving management strategies. The coupling of simulation and optimization methods constitutes an effective approach to determine sustainable management strategies for the conjunctive use of these water resources; yet, there are challenges that must be addressed. This paper reviews (1) hydrologic models applied for the simulation of GW-SW interaction in the water resources systems, (2) conventional optimization methods, and (3) published works on optimized conjunctive GW-SW use by coupling simulation and optimization methods. This paper evaluates the pros and cons of GW-SW simulation tools and their applications, thus providing criteria for selecting simulation–optimization methods for GW-SW management. In addition, an assessment of GW-SW simulation–optimization tools applied in various studies over the world creates valuable knowledge for selecting suitable simulation–optimization tools in similar case studies for sustainable water resource management under multiple scenarios. HIGHLIGHTS Reviewing hydrologic models applied for the simulation of GW-SW interaction.; Reviewing conventional optimization methods for conjunctive GW-SW.; Reviewing simulation–optimization methods for conjunctive GW-SW.; Evaluating the pros and cons of GW-SW simulation tools.; Providing criteria for selecting simulation–optimization methods for GW-SW management.;

Groundwater infiltration through cracked sewer pipes has caused significant economic losses. This paper presents a three-dimensional analytical expression for calculating the steady-state groundwater infiltration rate into sewer systems. As an extension of the previously developed two-dimensional model by the author, this new model can be used to simulate the infiltration through an orifice defect. The derived analytical expression has been validated with experimental results. The new model incorporates all the related resistances during the infiltration process, including the soil head loss and the orifice loss. The soil head loss is assessed with Ergun equation, which involves an inertial loss term in addition to the viscous loss. This has significantly extended the application range of the new expression. A new OS number (the ratio of orifice loss to soil loss) expression is also presented. The order analysis of the OS number expression has demonstrated that in most real cases, the head loss through the soil layer dominates the whole infiltration process.

The effectiveness of an emergency water supply using private wells has been asserted theoretically but not evaluated in detail. This paper aims to consider the effectiveness and shortcomings of emergency water supply based on local wells and to support policy formulation regarding groundwater usage in the event of a disaster. In Kamisu City, Ibaraki Prefecture, Japan, not only public-operated formal water supply points using water trucks but also informal water supply points using private wells were open to address water outages following the Great East Japan Earthquake of 2011. This study clarified the pattern of appearance and spatial distribution of those points by combining information from local newspapers, Internet archives, and an original questionnaire survey. In addition, the function of informal water supply points was quantitatively evaluated using GIS by comparing cases with and without informal water supply points. Analysis revealed that informal water supply points expanded the size of the serviced population within a 500-m radius of the water supply points by 47%, compared with cases when only formal water supply points were available. However, well water was not necessarily suitable for drinking owing to quality issues. As a policy lesson, the importance of sharing well information is indicated. HIGHLIGHTS In emergency, informal water supply points (IWSPs) using private wells are superior to public ones in terms of service area and speed of availability.; In this case study, IWSPs expanded the size of the serviced population within a 500-m radius of water supply points by 47%.; Groundwater cannot always be potable owing to quality problems.; Information sharing on IWSPs could encourage the appearance of additional water providers.;

In this paper, we consider the problem of completing missing records of annual water levels. The water levels records are taken once a year, in a group of neighboring wells. The collected records are assembled into a data matrix, where each column refers to a different well and each row refers to a different year. Yet some entries of the matrix are unknown and we want to assign appropriate values to these entries. The need for solving such problems arises in many applications, as many models and programs require a complete set of data. Traditional approaches for handling missing groundwater records are based on statistical techniques for treating missing data. The current paper introduces a new approach for solving this problem. One that is able to take advantage of the 'matrix structure' of annual water levels. This type of 'matrix imputing methods' has been proved successful in many modern areas, but it has not yet been tested in hydrology. Special attention is given to the question of assessing the quality of the imputed water levels. The proposed methods are examined on a number of test cases. [ABSTRACT FROM AUTHOR]

This paper mainly studied migration and transformation characteristics of dissolved organic matter (DOM) in underground aquifers. To achieve the research purpose, we carried out the dynamic column experiments of the DOM at different conditions indoors. In the experiment, the water of Wujiang River from Pingdingshan Coal-field is used as water sample, meanwhile, fine sand and marl rock are used as testing rock sample. A comparative study on migration and transformation characteristics of the DOM in different rock samples is done. The results show that, in the fine sand, the main effects are convection and dispersion, while the adsorption and biological effects are very weak. However, in the marl rock, besides existing convection and dispersion, the adsorption and biological effect are quite significant. And in the marl rock, convection and dispersion plays a major role in the early experiment, while adsorption is the main effect in the medium term, then the biodegradation dominates the final stage. With the increasing of temperature and seepage velocity in the fine sand, the impact of the convection effect becomes gradually weak, the dispersion effect gradually enhances, and, however, convection effect is still playing a dominant role. With the temperature rising in the marl rock, the adsorption effect becomes weak, but biodegradation is enhanced. As the seepage velocity increases in the marl rock, the adsorption and biodegradation both decrease.

Identification of the hydrochemical characteristics of the groundwater system in the mining area and the controlling factors of the water's chemical components is necessary to protect groundwater resources. In this study, 80 sets of groundwater samples were collected from three aquifers of the Liuzhuang coal mine (northern Anhui Province, China), and a total of eight indicators were selected for quantitative analysis of the chemical components of water. Conventional mathematical and statistical methods and Piper trilinear diagrams show that the cations in the groundwater samples of the mine area are mainly K+ + Na+ (92.4%), while the anions in the Cenozoic and Carboniferous aquifers are mainly Cl−, reaching 57.2% and 55.2%, respectively, and the anions in the Permian aquifer are mainly HCO3- (52.6%). Most of the water chemistry types are Cl-Na, HCO3-Na, and HCO3-Cl-Na. Analysis on the basis of Gibbs plots showed that the aquifer system in the mine area is primarily controlled by the water–rock interaction. The results of ion ratio analysis, principal component analysis, and cluster analysis showed that the dissolution of hydrochloric acid and alternating cation adsorption is more prominent in the Cenozoic and Carboniferous aquifers, while desulfurization is more significant in the Permian aquifer. HIGHLIGHTS This paper is the first to analyze the hydrochemical characteristics and controlling factors of three aquifers in the Liuzhuang coal mine (Northern Anhui Province, China).; The study determines the major cations and anions as well as the types of water chemistry in each aquifer in the study area.; The study shows that the aquifer system in the study area is mainly controlled by water–rock action.; Correlation analysis, ion ratio analysis, principal component analysis and cluster analysis were used to show the hydrochemistry of the three aquifers in the study area and to reasonably infer their genesis.;

This paper focuses on the distribution of volatile organic compounds (VOCs) in the surface water, soil, and groundwater within a chemical industry park in Eastern China. At least one VOC was detected in each of the 20 sampling sites, and the maximum number of VOCs detected in the surface water, groundwater, and soil were 13, 16, and 14, respectively. Two of the 10 VOCs with elevated concentrations detected in surface water, groundwater, and soil were chloroform and 1,2-dichloroethane. The characteristics of VOCs, which include volatility, boiling point, and solubility, could significantly affect their distribution in surface water, soil, and groundwater. However, due to the direct discharging of chemical industry wastewater into surface water, higher concentrations of VOCs (except chloroform) were detected in surface water than in soil and groundwater. Fortunately, the higher volatility of VOCs prevents the VOCs from impacting groundwater, which helps to maintain a lower concentration of VOCs in the groundwater than in both surface water and soil. This is because pollutants with relatively higher boiling points and lower solubilities have higher detection frequencies in soil, and contaminants with relatively lower boiling points and higher solubilities have higher detection frequencies in water, notably in surface water.

The identification of unknown groundwater pollution sources is one of the most important premises in groundwater pollution prevention and remediation. In this paper, an exploratory application of a least squares method to identify the unknown groundwater pollution source is conducted. Supported by a small amount of observation data and the analytical solutions of the pollutant transport model, the initial concentration, the leakage location and the pollutant mass are identified by using the least squares method under a sand tank experiment and a gas station area. In the sand tank experiment, it is found that the fitting errors of three cross-sections are within 6%. In the gas station area, it is found that the results are nearly consistent with the site investigation information. The results indicate that the least squares method has considerable application values in the identification of groundwater pollution sources. [ABSTRACT FROM AUTHOR]

Water from underground intakes is the main source of potable water for people in Poland, hence the protection of its resources is of great importance for the functioning of society and the economy. A new regulation in Polish Water Law imposes the obligation of performing risk analysis for water intakes, including the assessment of health hazards, factors negatively affecting water quality which are identified on the basis of hydrogeological and geological analyses. The main objective of the study was to determine the health risk for chlorides and to present an innovative approach to the health risk for non-toxic substances. In Upper Silesia, which is the most industrialized and urbanized area in Poland, old mining shafts are often used as deep wells in the water supply chain, and higher mineralization is the key feature of abstracted water which does not quite eliminate them as a source of drinking water supply. This paper proposes a new method of health risk determination as hazard index (HI). We present analysis of the health risks with increased concentration of chlorides in water which cause health effects for water consumers, especially for men, children aged 4-8, pregnant women and women during lactation. [ABSTRACT FROM AUTHOR]

The urban environment is a patchwork of natural and artificial surfaces that results in complex interactions with and impacts to natural hydrologic cycles. Evapotranspiration is a major hydrologic flow that is often altered through urbanization, although the mechanisms of change are sometimes difficult to tease out due to difficulty in effectively simulating soil-plant-atmosphere interactions. This paper introduces a simplified yet realistic model that is a combination of existing surface runoff and ecohydrology models designed to increase the quantitative understanding of complex urban hydrologic processes. Results demonstrate that the model is capable of simulating the long-term variability of major hydrologic fluxes as a function of impervious surface, temperature, water table elevation, canopy interception, soil characteristics, precipitation and complex mechanisms of plant water uptake. These understandings have potential implications for holistic urban water system management.

In situ remediation of ammonium-contaminated groundwater is possible through a zeolite permeable reactive barrier (PRB); however, zeolite's finite sorption capacity limits the long-term field application of PRBs. In this paper, a pilot-scale PRB was designed to achieve sustainable use of zeolite in removing ammonium (NH(4)(+)-N) through sequential nitrification, adsorption, and denitrification. An oxygen-releasing compound was added to ensure aerobic conditions in the upper layers of the PRB where NH(4)(+)-N was microbially oxidized to nitrate. Any remaining NH(4)(+)-N was removed abiotically in the zeolite layer. Under lower redox conditions, nitrate formed during nitrification was removed by denitrifying bacteria colonizing the zeolite. During the long-term operation (328 days), more than 90% of NH(4)(+)-N was consistently removed, and approximately 40% of the influent NH(4)(+)-N was oxidized to nitrate. As much as 60% of the nitrate formed in the PRB was reduced in the zeolite layer after 300 days of operation. Removal of NH(4)(+)-N from groundwater using a zeolite PRB through bacterial nitrification and abiotic adsorption is a promising approach. The zeolite PRB has the advantage of achieving sustainable use of zeolite and immediate NH(4)(+)-N removal.

The Songnen Plain in Northeast China is the only remaining black soil agricultural area in the world and is an important food base for China. The groundwater resources in this area are abundant, but human activities have caused them polluted. This paper established a groundwater vulnerability assessment to characterize the influence of human activities which used an entropy weight method. The index was tested using the nitrate pollution distribution in the groundwater to verify the effectiveness of this method. The results showed that areas with high specific vulnerability were distributed in the northern and eastern parts of the Songnen Plain and were consistent with areas that showed serious nitrate pollution of the groundwater. The correlation coefficient between these areas was 0.2536, which greatly improved the vulnerability assessment without superimposing human activities in the model. The results clearly showed that human activities increased groundwater vulnerability on the Songnen Plain. The evaluation method provided a reference for similar evaluations and a basis for the protection and management of groundwater resources in this region. [ABSTRACT FROM AUTHOR]

Latrines are an effective way for people in low- and middle-income countries to move away from open defecation. Guidelines are used to provide a recommended horizontal setback distance from a latrine to a downgradient well to ensure the safety of the well from subsurface contaminants. We collected 107 journal papers, books, and reports to critically review the recommended setback distances and how these recommendations are derived. It was discovered that the four most common guidelines/reviews are all based principally on just four field studies, all of which were conducted over 40 years ago, which casts doubt on a frequently used one-size-fits-all approach. More recent methods for latrine siting use both field data and some sort of modeling component to account for the different site conditions, but these models have not been verified for use outside their respective studies. They are also limited in how they consider the hydraulic connection between the latrine and the well. We recommend that future siting guidelines should focus more on vertical separation, include chemical contamination, and be based on models describing how latrines and wells are hydraulically connected, along with the fate and transport of potentially harmful contaminants. HIGHLIGHTS Most common guidelines are based on four field studies, conducted over 40 years ago.; Latrine-siting guidelines must account for the vertical transport of pollutants.; Siting guidelines should account for the distinct features of loadings and transport of bacteria and viruses.; In situ treatment technologies and resource recovery strategies may influence pollutant loadings.; Models can assist with site-specific siting.;

Bergen city centre is prone to both subsidence and flooding. With a predicted increase in precipitation due to climate change, a higher proportion of rainfall becomes surface runoff, which results in increased peak flood discharges. In addition, it has been predicted that sea-level rise and increasing storm surges will result in coastal flooding. In this study, the dual hazards of flooding and subsidence are analysed to exemplify possible risk assessment maps for areas most prone to the combination of both. Risk assessment maps are a support tool to identify areas where mitigation of subsidence and adaptation for surface water management will be most efficient and measures can be implemented. The results show that dual hazard assessment, like that described in this paper, can be a useful tool for decision-makers when prioritizing areas to implement measures such as Sustainable Urban Drainage Systems. [ABSTRACT FROM AUTHOR]

Groundwater is vulnerable to overdraft and depletion, especially in relatively dry regions where natural recharge rates are very low and groundwater is the main source of water. Artificial recharge of groundwater with treated wastewater has been widely adopted as a technique to replenish the overdraft aquifers. Indeed, in the USA, the technique has been practised for a long time. In 1981, a design procedure manual was developed for practitioners by the United States Environmental Protection Agency (USEPA). It was updated in 1984 and lastly in 2006. However, the design procedure has not been fully generalized for the different situations and has not been fully formalized in order to allow its automated implementation on calculation software (i.e. spreadsheet). Therefore, in this paper we formalized and generalized the USEPA design procedure to achieve an automated iterative method of calculation which can be easily implemented in a spreadsheet.

In this paper we present a new simulation-based integrated water management tool for sustainable water resources management in arid coastal environments. This tool delivers optimised groundwater withdrawal scenarios considering saltwater intrusion as a result of agricultural and municipal water abstraction. It also yields a substantially improved water use efficiency of irrigated agriculture. To allow for a robust and fast operation we unified process modelling with artificial intelligence tools and evolutionary optimisation techniques. The aquifer behaviour is represented using an artificial neural network (ANN) which emulates a numerical density-dependent groundwater flow model. The impact of agriculture is represented by stochastic crop water production functions (SCWPF). Simulation-based optimisation techniques together with the SCWPF and ANN deliver optimal groundwater abstraction and cropping patterns. To address contradicting objectives, e.g. profit-oriented agriculture vs. sustainable abstraction scenarios, we performed multi-objective optimisations using a multi-criteria optimisation algorithm.

Estimating groundwater infiltration into sewer systems is important for wastewater treatment operators and municipalities. This paper presents an approximate solution for steady-state groundwater infiltration into sewer systems through line defects. The groundwater table was assumed to be horizontal and the aquifer homogeneous and isotropic. Mobius transformation technique and equivalent circumference method were introduced to solve the governing equation. The infiltration rate is found to be controlled by the hydraulic conductivity of the surrounding soil, the total hydraulic head above the sewer pipe, the size of the sewer pipe, the position of the defect, and the size of the defect.

The estimation of the groundwater recharge in a karstic system becomes an important challenge due to the great hydrodynamic variability in both time and space. This paper proposes a two reservoir conceptual model to simulate inflow into both the conduit system and the fissure network system based on the analysis of the spring hydrograph. The structure of the model and the governing equations are proposed on the basis of the physical considerations, with the assumption that flow at the outlet of the reservoirs obeys a linear threshold function. The model is applied on the Houzhai karstic underground river basin where it successfully reflects the temporal recharge distribution. The simulated accumulation recharge is 34.29 mm, which is reasonable in relation to the actual rainfall of 92.8 mm. The variations of water volume in two reservoirs represent the storage and transform characteristics of the karst aquifer system. However, this model is particularly well suited to simulate the recharge event after intensive rainfall.

Defining aquifer permeability distribution accurately over large areas is often debated in hydrogeology. The operational efforts to calculate hydraulic conductivity with classical aquifer tests are significant; however, accurate knowledge of permeability areal distribution is fundamental both from a hydrogeological and a modeling standpoint. This paper presents an empirical relationship between the transmissivity (T) and the specific capacity (SC) values obtained from experimental aquifer and well tests. All experimental values were obtained from 50 mm wells in middle Venetian plain artesian gravel aquifers. Many other authors have presented empirical relationships between T and SC, but most are related to fissured/karst aquifers, and only a few concern alluvial porous aquifers. Analysis of the T vs. SC relationship standardized residuals shows that a linear relationship produces statistically significant normal residuals compared with an exponential relationship.

Globally, irrigated agriculture is the largest abstractor, and predominant consumer, of groundwater resources, with large groundwater-dependent agro-economies now having widely evolved especially in Asia. Such use is also causing resource depletion and degradation in more arid and drought-prone regions. In addition crop cultivation practices on irrigated land exert a major influence on groundwater recharge. The interrelationship is such that cross-sector action is required to agree more sustainable land and water management policies, and this paper presents an integrated vision of the challenges in this regard. It is recognised that 'institutional arrangements' are critical to the local implementation of management policies, although the focus here is limited to the conceptual understanding needed for formulation of an integrated policy and some practical interventions required to promote more sustainable groundwater irrigation.

Phenol is an industrially key compound that has a wide range of applications and also one of the most commonly found toxic pollutants in wastewaters and groundwater. This paper demonstrates the applicability of in situ remediation at a deactivated industrial site using source zone excavation and sediment mixing associated with nutrients delivery into groundwater. Sediment excavation and mixing displaced the entrapped source zone enhancing mass transfer into groundwater and contaminant bioavailability. A nutrient solution prepared with nitrate, phosphate, sodium hydroxide and hydrogen peroxide was continuously delivered into groundwater to stimulate biodegradation and restrict plume migration. The observed correlation between phenol-dependent Enterobacteriaceae concentrations throughout the remediation time frame supported circumstantial evidence of biodegradation. Phenol concentration in groundwater (up to 1,300 mg/L) was reduced >99% after 5 months following remediation and remained under the established site specific target level (4 mg/L). Nitrate and phosphate concentrations returned to background concentrations levels at the end of the remediation. Overall, the proposed in situ remediation scheme was effective to remediate this particular aquifer contaminated with phenol for over 20 years.

This research paper aims to determine the genetic origin of the chemical elements in groundwater. It deals with the results of physicochemical parameters, to evaluate the hydro-geochemistry of groundwater in rural-urban fringe of district Bareilly, India. Pre- and post-monsoon sampling has been carried out, which reveals inter-seasonal variability effect on the hydro-geochemical processes. Geochemical modeling especially computation of saturation index was undertaken using the WATEQ4F model. Majority of samples fall in the category of undersaturation, which further suggests that groundwater still has potential to dissolve more minerals. Chemical categorizations of groundwater samples were performed with the help of the Aquachem model. Grouping of groundwater on the Piper diagram reveals a common composition and origin. In most of the area, water facies is of Ca(2+)-HCO(3)(-) type in both the seasons. It also indicates that in pre-monsoon, ion exchange is the dominant process, whereas in post-monsoon, both ion exchanges as well as reverse ion exchanges are reported in the groundwater of the study area.