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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]

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.;

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.;

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]

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.;

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]

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]

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.;

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]

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]

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.;

This paper reviews diagnostic tools that can be used at waterworks to investigate the physical and operational state of rapid granular filters. Diagnostic tools can be of interest for the Water Safety Plans of WHO to monitor filters in a proactive manner. The review considers conventional and state of the art tools and tools currently in development or conception stage. The development status, usability and availability of each tool and procedure are discussed. Some conventional, simple and low-tech tools are available which can rapidly provide both qualitative and quantitative information. However, it is difficult to relate this information to guideline values or design criteria because the tools are often not documented and are most often used with past experience or rules of thumb. New tools such as the total dissolved gas probe, salt tracers and ammonium profiles are presented. Potential tools from the soil and groundwater field such as the hand penetrometer, time domain reflectometry and ground penetrating radar are suggested. The paper discusses how the filtration process can be optimized once a malfunction is recognized by the diagnostic tools, and finally, research and development needs are identified. [ABSTRACT FROM AUTHOR]

Target 7C of the Millennium Development Goals is to "halve, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation". However, the corresponding indicator measures the "proportion of population using an improved drinking water source". This raises the question of whether "safe" and "improved" can be used interchangeably. This paper tests this hypothesis by comparing microbiological water quality in 346 different water sources across the District of Amuria in Uganda to each other and to defined standards, including the WHO drinking water standard of zero TTC per 100 ml, and the Ugandan national standard of 50 TTC per 100 ml. The water sources were grouped into six different categories: boreholes, protected springs, covered hand dug wells, open hand dug wells, open water and roofwater harvesting. The paper concludes that the ranking from the highest to the lowest microbiological quality water was: boreholes, protected springs and roofwater harvesting, open and covered hand dug wells, open water. It also concludes that sanitary surveys cannot be used to predict water quality precisely; however they are an essential component of the monitoring of safe water supplies. [ABSTRACT FROM AUTHOR]

The zinc load from the Dalãlven River to the Baltic Sea is greater than for any other watercourse in Sweden. This paper investigates zinc mass flows into and through the Dalälven River from major mining areas within its drainage basin. Reported zinc mass flow data for this river are re-analyzed using an input-output flow analysis approach. Results show major inconsistencies in previous data interpretations which totally neglected possible zinc mass load contributions from the groundwater system to the river. This paper quantifies significant subsurface zinc load contributions that are consistent with all independently available data. Furthermore, a possible explanation for why these subsurface contributions may have been missed in previous studies and by the prevailing Swedish environmental monitoring system is provided. The study indicates that the input-output flow analysis approach may be generally useful for identifying and quantifying diffuse, unmonitored and uncertain pollutant load contributions from ground- to surface water systems. [ABSTRACT FROM AUTHOR]

The paper deals with a method for quantification of infiltrating groundwater based on the variation of diurnal pollutant load and continuous water quality and quantity monitoring. Although the method gives us the potential to separate particular components of wastewater hygrograph, several aspects of the method should be discussed. Therefore, the paper investigates the cost-effectiveness, the relevance of pollutant load from surface waters (groundwater) and the influence of measurement time step. These aspects were studied in an experimental catchment of Prague sewer system, Czech Republic, within a three-month period. The results indicate high contribution of parasitic waters on night minimal discharge. Taking into account the uncertainty of the results and time-consuming maintenance of the sensor, the principal advantages of the method are evaluated. The study introduces a promising potential of the discussed measuring concept for quantification of groundwater infiltrating into the sewer system. It is shown that the conventional approach is sufficient and cost-effective even in those catchments, where significant contribution of foul sewage in night minima would have been assumed. [ABSTRACT FROM AUTHOR]

This paper presents considerations for the application of the natural water isotope method on catchment areas. For the estimation of the amount of infiltration and inflow in sewer systems the paper shows two applications in the Netherlands: one successful application on a relatively small catchment area with a simple geo-hydrological groundwater system and one unsuccessful application in an area that shows a large heterogeneity of δ18O values in groundwater. Also, the paper focuses on the validity of the assumption that the isotopic ratios of drinking water are equal to those of strict domestic wastewatar. In the transition from drinking water to strict wastewater it is shown that changes in isotopic composition of the water due to evaporation in common household appliances and effects inside the human body are insignificant. However, the presence of high-efficiency condensing boilers in an area can significantly influence the δ18O value of strict wastewater, especially in winter months. This effect should be taken into account when applying the isotope method in such areas. [ABSTRACT FROM AUTHOR]

According to the Paris climate change agreement, temperature increases of around 1.5 or 2.0 °C by 2050 are bound to increase the amounts of evaporation and evapotranspiration, which are among the losses from surface water bodies, such as rivers, lakes, reservoirs and dams. In order to reduce these losses and support local water supply, subsurface dam construction projects are at the forefront in many countries, especially in arid and semi-arid regions, even in subtropical climate regions. In the literature, there are classical methodological explanations for underground dams with quite insufficient and restrictive interpretations. In this paper, two very similar but different new alternatives are proposed as longitudinally and laterally supported underground dams with inspirations from historical qanat groundwater subsurface structures. Both types are supported by artificial trenches with higher hydraulic conductivity than the surrounding Quaternary alluvial deposits to increase external and meanwhile to support internal areal recharge possibilities between the trenches and the surrounding natural porous, weathered and fractured layers. It is noticed that trench-supported subsurface dams are more effective, affordable, sustainable and manageable than classical alternatives available in the literature. It is recommended that a more refined subsurface groundwater movement mathematical formulation should be developed in the future. HIGHLIGHTS Subsurface dams play an important role against climate change impacts in many regions.; Old qanat groundwater technology led to longitudinal and lateral trench-supported innovative subsurface dam designs.; These innovative subsurface dam designs provide rainfall and runoff harvesting possibilities.; Up-to-date literature review is presented and there is not enough subsurface dam information in the open literature.;

There have been widespread concerns about solute transport problems in fractured media, e.g. the disposal of high-level radioactive waste in geological fractured rocks. Numerical simulation of particle tracking is gradually being employed to address these issues. Traditional predictions of radioactive waste transport using discrete fracture network (DFN) models often consider one particular realization of the fracture distribution based on fracture statistic features. This significantly underestimates the uncertainty of the risk of radioactive waste deposit evaluation. To adequately assess the uncertainty during the DFN modeling in a potential site for the disposal of high-level radioactive waste, this paper utilized the probabilistic distribution method (PDM). The method was applied to evaluate the risk of nuclear waste deposit in Beishan, China. Moreover, the impact of the number of realizations on the simulation results was analyzed. In particular, the differences between the modeling results of one realization and multiple realizations were demonstrated. Probabilistic distributions of 20 realizations at different times were also obtained. The results showed that the employed PDM can be used to describe the ranges of the contaminant particle transport. The highpossibility contaminated areas near the release point were more concentrated than the farther areas after 5E6 days, which was 25,400 m². [ABSTRACT FROM AUTHOR]

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. HIGHLIGHTS A text-mining tool was used to distinguish sources, types, exposure pathways, and effects of microplastics (MPs).; There is a lack of common criteria to compare the behavior of MP in groundwater and their potential environmental and health impacts.; There is a need for standardized sampling, extracting, and analytical methods on microplastics in groundwater and biological matrices.;

This paper presents to study the performance of machine learning techniques consisting of multivariate adaptive regression spline (MARS), feed forward neural network-back propagation (FFNN-BP), and decision tree regression (DTR) for estimating the physico-chemical properties of groundwater in the coastal plain area in Vinh Linh and Gio Linh districts of Quang Tri province of Vietnam. With 290 groundwater samples collected in two districts, this study has identified three main elements CO2, Ca, CaCO3 for simulation. Quantitative analysis results have shown that these three components are such as CaCO3 with from 0 to 25.8 mg/l, Ca from 0 to 87.55 mg/l and CO2 from 0 to 12 mg/l. In the present examination, groundwater quality index (GQI) values and their representative categories have been referred by the Vietnam Groundwater Standard (QCVN01). Furthermore, the statistical accuracy parameters were used to compare among models. To deploy FFNN-BP and DTR, different types of transfer and kernel functions were tested, respectively. Determining the results of MARS, FFNN-BP and DTR showed that three models have suitable carrying out for forecasting water quality components. Comparison of outcomes of MARS model with the FFNN-BP and DTR models indicated that this model has good performance for forecasting the elements of water quality, its level of accuracy was slightly more than the other. To assess the accurate values of the models according to the measurement parameters for training phase illustrated that the order of the models was MARS to give the best result, followed by DTR and finally FFNN-BP, respectively. HIGHLIGHTS Machine learning methods are used for spatial modeling of physico-chemical properties of groundwater.; MARS performances suitable precision compared to the DTR and FFNN-BP models.; Total CaCO3 value in the experiment samples adapted the regular limit of QCVN01 with ‘Excellent’ point.; The quality of water parameters (i.e., CaCO3, Ca, and CO2) of the coastal plain area was predicted.; The study results have shown that the water quality in these two districts is usable for humans, livestock, and agriculture activities.;

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. HIGHLIGHTS A large part of Romania's population uses water from wells as a source of drinking water.; Monitoring of fluoride in drinking water samples.; Optimization and validation of the potentiometric method for determining fluoride ions with a selective ion electrode.; The performed health risk assessment of fluoride exposure due to groundwater consumption is based on the estimated daily intake (EDI) and the hazard quotient (HQ).;

The paper presents the activity performed at the University of Brescia by students and researchers, belonging to different Mediterranean cultures and different disciplines, to prepare a documentary exhibition on irrigation techniques in water scarcity conditions, on the occasion of the International Year of Soils 2015. Traditional irrigation techniques were identified as a key aspect of soil conservation and agricultural practices, to build living and autopoietic ecosystems, also in adverse climatic conditions, and to adapt to climatic changes. Being a structural source of ecosystem survival, and being based on long-lasting observation of the climate and of the environment, they have deep roots in local cultures and they were identified as a common ground also for multicultural interaction. The core of the exhibition is structured in sections focused on techniques for collecting groundwater, atmospheric humidity and surface water, on water lifting techniques and on water distributive systems. The final section of the exhibition is devoted to the oases which are presented as an equilibrium ecosystem, established upon the alliance between man and nature and founded on the capability of collecting water. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This article provides updated status of the arsenic affected rural habitations in India, summarizes the policy initiatives of the Ministry of Drinking Water & Sanitation (Government of India), reviews the technologies for arsenic treatment and analyses the progress made by states in tackling arsenic problems in rural habitations. It also provides a list of constraints based on experiences and recommends suggested measures to tackle arsenic problems in an holistic manner. It is expected that the paper would be useful for policy formulators in states, non-government organizations, researchers of academic and scientific institutions and programme managers working in the area of arsenic mitigation in drinking water, especially in developing countries, as it provides better insights compared to other available information in India on mitigating arsenic problems in drinking water in rural areas. [ABSTRACT FROM AUTHOR]