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Although the quantification of lost water, due to leakages in pressure management areas (PMAs) is a crucial task for all water agencies' financial viability, currently there is no rigorous approach for their parametric modeling including the effect of inlet/operating pressures. In this work we develop a probabilistic model for minimum night flow (MNF) estimation in water distribution networks that: (1) parametrizes the MNF as a function of the network's specific characteristics (topography, length of the pipeline grid, pipe diameters, density of connections etc.), and (2) parametrically describes leakages in individual Pressure Management Areas (PMAs) as a function of the inlet/operating pressures. The effectiveness of the developed model is tested in a large-scale real-world application to 43 PMAs of the water distribution network of the city of Patras in western Greece, which cover an area of approximately 18 km2 with approximately 538 km of pipeline serving more than 150 000 consumers. The strong point of the current methodology is that it allows for confidence interval estimation of the parametrized MNFs, including inlet pressure effects, a strong indicator regarding the level of leakages in PMAs. Thus, the current parametric model can serve as a useful tool for water experts and officials, allowing effective selection of proper leakage reduction technics based on a robust probabilistic approach. [ABSTRACT FROM AUTHOR]

Irrigation remains an essential component of food security in many parts of the world. Kyrgyzstan is included in this number, but, at the same time, the water resources of Kyrgyzstan are still not used efficiently enough. This study gives an assessment of the conditions for the formation and quality of water resources in the Kyrgyz Republic based on an analysis of the new draft State Program for the Development of Irrigation of the Kyrgyz Republic for 2017–2026 and an assessment of the irrigation facilities of the Republic that takes into account their relevance and economic and technical indicators. The modern realities demonstrate the need for a careful and rational use of natural resources. High-quality, safe water is becoming one of the most in-demand resources in many countries of the world, therefore, "water powers" can make water their strategic resource, but the operation and maintenance of water-management systems requires significant financial investments. Payment for water use can become the basis for reform of the economic mechanism of interstate relations. The study resulted in the formulation of reasonable directions for the strategic nature of the modernization of the reclamation fund and the expansion of the volume of ongoing reclamation activities related to high-priority measures for the development of the rational use of the water balance. [ABSTRACT FROM AUTHOR]

Constantly developing monitoring systems provide a large amount of raw data. In many cases, the operators of water supply systems (WSS) have already reached their perception limit for analysing information. Therefore, the managing process of the WSS requires quasi-intelligent informatics systems, the main purpose of which is to minimise the WSS operating costs in addition to maintaining the proper water delivery to customers. It can be achieved by the detection of abnormal functioning of WSS operations (leakages, water outages). The standard SCADA monitoring systems, in most cases, are not able to distinguish a significant water leakage and water tank filling process. Such cases occur relatively often in complex water supply systems with many water tanks. The aim of this paper is to present the quasi intelligent method of detecting abnormal WSS functioning, including its concepts and effects after a 3 month period operation. The essence of the detection method is the integration of numerical model (built-in Bentley WaterGEMS software) and SCADA monitoring system. The monitoring data are constantly compared to the simulation results and when accepted accordance limits are exceeded, the appropriate alerts are generated. Such solution cause the WSS operator does not need to analyse SCADA system indications constantly. The additional application of the method enables the detection of essential water leakages. [ABSTRACT FROM AUTHOR]

Accurate and reliable optimization and simulation of the dam reservoir system to ensure optimal use of water resources cannot be achieved without precise and effective models. Providing insight into reservoir system operation and simulation modeling through a comprehensive overview of the previous studies and expanding research horizons can enhance the potential for accurate and well-designed models. The current research reviews previous studies that have used optimization methods to find optimal operating policies for a reservoir system over the past 20 years. Indeed, successful operating policies cannot be obtained without achieving accurate predictions of the main hydrological parameters in the reservoir system, which are inflow and evaporation. The present study focuses on giving an overview of the applications of AI-based models for predicting reservoir inflow and evaporation. The advantages and disadvantages of both optimization algorithms and predictive models have been summarized. Several recommendations for future research have also been included in the present review paper. [ABSTRACT FROM AUTHOR]

We introduce two alternative probabilistic approaches for minimum night flow (MNF) estimation in water distribution networks (WDNs), which are particularly suited to minimize noise effects, allowing for a better representation of the low flows during night hours, as well as the overall condition of the network. The strong point of both approaches is that they allow for confidence interval estimation of the observed MNFs. The first approach is inspired by filtering theory, and proceeds by identifying a proper scale for temporal averaging to filter out noise effects in the obtained MNF estimates. The second approach is more intuitive, as it estimates MNF as the average flow of the most probable low-consumption states of the night flows. The efficiency of the developed methods is tested in a large-scale real world application, using flow-pressure data at 1-min temporal resolution for a 4-monthly winter period (i.e. November 2018–February 2019) from the water distribution network of the City of Patras (i.e. the third largest city in Greece). Patras' WDN covers an area of approximately 27 km2, consists of 700 km of pipeline serving approximately 213,000 consumers, and includes 86 Pressure Management Areas (PMAs) equipped with automated local stations for pressure regulation. Although conceptually and methodologically different, the two probabilistic approaches lead to very similar results, substantiating the robustness of the obtained findings from two independent standpoints, making them suitable for engineering applications and beyond. [ABSTRACT FROM AUTHOR]

The revision of the Drinking Water Directive (DWD), which the process of consultation by the European Parliament is coming to the end, includes a commitment for all Member States to assess the level of water leakage. The overarching aim of this action is to reduce water loss through leaks. In regard to this, use of performance indicators as suitable to enable assessment of water utility performance with regard to leakage reduction, including impacts on environment and cost-efficiency, is recommended. The paper provides results from water losses evaluation with the set of performance indicators (PI), considering dependence on the availability of resources and specific operating conditions. An analysis of different PI that are necessary to evaluate in most of leakage reduction methods was conducted considering step-by-step approach. Furthermore, the most relevant data for leakage analysis and management on a network level was determined. Presented PI can be used to improve leakage management of small water supply system. Similarly as in the Deming cycle, the described tool provides for planning activities, executing activities in accordance with the plan, checking the degree of execution of objectives included in the plan, and on the basis of conducted analyses and lessons learned, the so-called improvement. The results of the analysis lead to the conclusion that through a comprehensive, systematically improved strategy, the high effectiveness of the system could be reach. The reliable monitoring does not have to be based on advanced technological methods, which are often unavailable for small water supply system, due to high investment and operating costs. The results indicate that integrated IT systems, as SCADA, might not be directly beneficial to water loss management in small networks with moderate leakage levels. [ABSTRACT FROM AUTHOR]

Water companies and their consumers affected with leakages in water distribution system worldwide. This has attracted many practitioner's attention as well as researchers over the past years. Selected study area suffers from water losses of about 10 to 15% which accounts to loss of about 9 to 9.75 million liters per month. The present study was under taken to understand, analyze and evaluate the losses and suggest preventive measures of wrapping and repair clamping for control of these losses. The assessment of water losses is done through comparative analysis of data using Microsoft Excel software. Population forecasting is done in context of assessing the amount of water lost that can be prevented in future decades, adjusting to increased water demand and losses. For better efficiency of the suggested methods, experimental analysis was carried out on a reduced scale model of a single stretched pipeline. Cost estimation of the preventive measures was done by obtaining information about the materials used by trading professionals. [ABSTRACT FROM AUTHOR]

This study aims to identify issues plaguing rural India's water supply chain and present a general methodology for the implementation of an IoT-based water distribution and management system in a rural setting. Through the literature review, significant hurdles in the water supply chain of rural India, as well as the potential role of IoT in water supply chain management, were recognized. An implementation plan was proposed to design an IoT-based water distribution and management system with the help of flow meters, ultrasonic sensors, motors, etc. Also, the feasibility of such a system was explored with the help of a use case. This study highlighted that one of the most significant reasons for water scarcity in rural India is the lack of proper infrastructure leading to water resources mismanagement. In the context of our use case, despite adequate availability of physical water for consumption, by the time water is delivered to the consumers, a significant amount of it is wasted due to the lack of an efficient water management system. It was determined that the investment return for the proposed system would break even within three months of installment. This study's results are based on inputs from governmental data collected in the Census report of 2011. As such, the ground level scenario is bound to be comparatively different today. This study is anticipated to guide governmental organizations and policymakers in the formulation of new strategies. [ABSTRACT FROM AUTHOR]

In water distribution systems, depending on various factors, the failures and leakages occur in service connections, main pipes, and fittings. A significant part of these leakages are not visible at surface, occur underground, and are expressed as unreported leakages. The aim of this study was to investigate and analyze the effect of the unreported leakages occurring on service connections to water loss volume by applying a water loss model based on the minimum night flow and the active leakage control methods. For this aim, a total of 14 district metered areas in Malatya water distribution system were selected as study area. For the water loss model, the minimum night flows were monitored at the lowest consumption times, and the potential leakages points were detected by applying active leakage control method. As a result of this method, a high rate of 77.4% of the identified leakages was observed in service connections. After repairing the leakages detected in the district metered areas, it was determined that a total reduction of approximately 148.9 l/s was achieved at minimum night flow. In the study, it was determined that the water loss model developed on the basis of minimum night flow and active leakage control methods provided important contributions to the monitoring, detection and control of the unreported leakages. Furthermore, according to the developed water loss model, it has been determined that a significant portion of the unreported leakages are caused by leakages that occur in the service connections and cause significant water loss. [ABSTRACT FROM AUTHOR]

The main objective of this study is to estimate the total economic loss due to inefficient use of irrigation water in Tunisia. Several approaches have been used for this purpose. The optimal level of water application for different crops is calculated using the actual crop evapotranspiration which is based on FAO-56 method. The residual imputation and yield comparison methods have been used to estimate the economic value of irrigation water for different irrigated crops in different bioclimatic areas. For the empirical analysis, primary data were obtained from a series of surveys that covered 78% of the total irrigated areas and were collected within the framework of the "Virtual Water and Food Security in Tunisia project" (2013–2015). Secondary data about land distribution of crops in Tunisia were taken from the Ministry of Agriculture (2016). Around 724 farms were randomly sampled considering their bioclimatic area, farm type, and production system. The survey included the main 20 crops produced in Tunisia. Results show that most of farmers are either under or over utilizing irrigation water. The value of total direct economic losses, at the country level, of both types of water inefficiencies, was estimated to around 470 million Tunisian Dinars. Therefore, an improvement of water use efficiency at field level through dissemination of information/knowledge on irrigation scheduling and crop water requirements by extension services to farmers is needed to reduce this huge economic loss, reach higher sustainability in water use and improve food security. [ABSTRACT FROM AUTHOR]

The definition of the relationship between the leak outflow, the total head at the leak and other relevant parameters such as pipe stiffness, leak dimension and shape has been object of extensive studies. The attention to a correct estimation of leakages, leak law, is crucial for the management of water distribution systems. Water utilities, in fact, can reduce leakage levels through the leak detection or more usually by pressure management. In the last cases, the known of the relationship between leak discharge and pressure is fundamental. In recent decades, the use of the Torricelli equation has been questioned, because some experimental results showed that it can yield unsatisfactory results, and other formulations have been suggested to model water leakages in water distribution networks. To investigate the effectiveness of the formulations suggested by different authors, an experimental campaign was carried out at the Environmental Hydraulic Laboratory of the University of Enna (Italy) for leaks of different shape and size in polyethylene pipes. The results of the laboratory experiments contribute to clarify the applicability of the leak law for circular and rectangular leaks and suggest that Torricelli formulation is valid in absence of leak area deformation. Furthermore, the analysis contributes to the knowledge of the coefficients of the leak laws used to estimate the leakage outflow. [ABSTRACT FROM AUTHOR]

Objective analysis of water resources development in the territory of Vologda oblast in period from 2005 to 2014 is given. It was found that water withdrawal from water sources decreased by 22.4%, wastewater discharge into water bodies decreased by 22.6%, and the total volume of recycling and successive water use increased by 2.0%. The dynamics of the distribution of water resources between economic sectors is given. Unreasonable water losses were identified in water use systems and their extent was assessed. The main directions in water economy in the production and domestic sectors are determined. Steps for improving the efficiency of water resources development in the region are proposed. [ABSTRACT FROM AUTHOR]

Water distribution networks are high energy and low efficiency systems, where water pressure is frequently reduced by dissipation valves to limit leakage. The dissipation produced by the valves can be converted to energy production to increase the efficiency and reduce the energy impact of networks. If valves are replaced by turbines or pumps as turbines (PATs), they can both reduce pressure and produce energy. This study focuses on the optimal location of PATs within a water distribution network in order to both produce energy and reduce leakage. A new optimization model is developed consisting of several linear and non-linear constraints and a newly proposed objective function, where the turbine installation costs as well as the energy production and the economic saving due to the reduction of leakage can be accounted all together. The case study shows that the application of the mathematical model to a synthetic network ensures better results, in terms of both energy production and water saving, in comparison to other procedures. [ABSTRACT FROM AUTHOR]

The use of indices, describing aquifer vulnerability and the risk of groundwater pollution, is a basic tool for the implementation of a sound water management plan, especially in densely populated and intensely cultivated areas. In this study, the groundwater contamination risk of the Caserta Plain (Southern Italy) was assessed through the integration of hazards defined on the basis of the different land uses, of the intrinsic vulnerability calculated by applying the SINTACS model and of the groundwater value evaluated by considering water wells density. In order to evaluate the evolution of the risk of groundwater pollution, the proposed methods were applied in the study area for both 2001 and 2009. The resulting specific vulnerability (SINTACS-L) and the risk (GRA) maps, created in a GIS environment, were validated by the comparison with the nitrate concentration distribution. The application of the proposed approach to the study area highlighted the strengths and weaknesses of each method and, at the same time, showed that their combination can provide an overall view of the threats posed to groundwater resources by the human activities affecting the territory. Considering both the benefits and the issues of the proposed approach, overall, the groundwater risk map is thought to be a robust tool to support water managers in defining future plans for water resources exploitation and land use. [ABSTRACT FROM AUTHOR]

The appropriate management of water resources in the world is a policy that can be used in the line of optimum water consumption. One of these management instructions is optimum designing of canal sections for transferring water in irrigation networks. Since water losses in an irrigation network include seepage and evaporation losses, and regarding that the seepage losses depends on the geometry of canal and evaporation losses depends on the free water level, the designing of canal section will be done with the minimum water loss which include minimizing the seepage and evaporation from the canal under uniform flow. Until now, the optimum designing has been done based on relations some of which have high errors in exact estimation of seepage value, so it is necessary to apply a more exact method in optimization process for estimating the seepage value in canal. In this study, the canal seepage value for different states have been modeled by using SEEP/W software package, then the most appropriate soft model have been extracted between the input data (the geometry of canal and the technical characteristics of the bed soil) and output data (seepage). The extracted soft model had been compared to other experimental relations of seepage estimation, and beside confirming its high exactness in estimating seepage compared to other methods, it also have been used as a more efficient method for estimating seepage in optimization process with the aim of minimizing water losses in canals. In the proposed structure, Manning equation has been introduced as the major constraint, allowed minimum velocity, and Froude number as the minor constraint of the problem. The results of this study have been presented in form of dimensionless diagrams that made it possible to design the canal's dimensions simply. Investigating the results of present study and previously conduced researches indicate the significant changes of canal's optimum dimension in the present study compared to other researches due to using the proposed method for estimating the seepage. [ABSTRACT FROM AUTHOR]

The high level of the non-revenue water (NRW: water not generating revenues) is a well-acknowledged problem water utilities are straggling with in areas facing water scarcity. High NRW values jeopardize the sustainability of water utilities, especially in cases, where these values exceed 50 % of the System Input Volume. WATERLOSS project developed a Decision Support System to help water utility managers design the most effective/efficient NRW reduction strategy. The project's first step was to evaluate the performance of the water distribution systems selected as case studies. The paper presents the respective results of eight cases from Cyprus, Greece, Italy, France and Spain, based on a modified International Water Association Water Balance adapted to the water pricing practices met across the Mediterranean (high Fixed Charge included in the water tariffs). The results revealed that although almost all cases experience high NRW levels, the high Fixed Charge reduces the actual revenue losses, thus providing a perfect excuse to the managers of the local water utilities do almost nothing to address the actual extent of the NRW problem in their systems. [ABSTRACT FROM AUTHOR]

The widely adopted alternate wetting and drying (AWD) irrigation for rice production is increasingly needed to quantify the different water outflows and nitrogen leaching losses. We investigated the effects of AWD on percolation, water productivity, nitrogen leaching losses, and nitrogen productivity through in situ experiments. Results show that AWD reduced irrigation water without a significant impact on grain yields and increased the mean water productivity by 16.9 % compared with continuously flood irrigation (CFI). The mean nitrogen productivity of 135 kg ha N level was 22.2 % higher than that of 180 kg ha N level, although grain yields substantially increased because of nitrogen fertilization application. The percolation was also reduced by 15.3 % in 2007 and 8.3 % in 2008 compared to CFI. However, the cumulative percolation of the first 5 days after irrigation in AWD plots is significantly larger than that in CFI plots. The NH-N and TN leaching losses of AWD and CFI had no significant variations while the NO-N leaching losses were increased caused by AWD. The total NH-N, NO-N, and TN leaching losses of AWD in the first 3 days after irrigation were higher than that of contemporaneous CFI. The results indicate that the bypass or preferential flow and strengthened nitrification-denitrification nitrogen transformation processes because of alternate wetting and drying potentially decrease the water saving effectiveness and increase the NO-N loading to the groundwater. [ABSTRACT FROM AUTHOR]

Water is currently an essential and strategic resource for society and its importance will rise in the future due to the increasing number of threats. However, water management is not currently up to par taking into consideration this well acknowledged importance. Generally speaking, water use is not efficient and loss figures are often too high. The reasons behind this situation are complex and diverse, however, in principle, they can be divided into four categories: cultural, political, social and economic. Since the latter are of most importance, this paper focuses on water costs from source to tap. The economic analysis presented quantifies the costs of a sustainable urban water service in a structured way. The second part of the paper present a case study in which the economic losses linked to leakage are assessed as a function of how expenses are recovered. The cost of apparent losses could also be assessed in a similar way and will always be higher, since apparent losses (unlike real ones) are present throughout the whole water cycle, thus increasing the unit costs. [ABSTRACT FROM AUTHOR]

Despite the growing research about water utilities, some questions still remain to be solved on the supply side, which are frequently absent from empirical studies based on the estimation of cost functions. This paper aims to fill to some extent this gap in the literature by focusing the consequences of water losses reduction and the management of water resources based on their availability at an integrated river basin level. Major findings derived from the estimation of a multiproduct cost function suggest advantages from reducing water losses, given that an adjusted measure of economies of scope, adapting the fact that water lost cannot be sold, reveals that there are small diseconomies of scope. In addition, generally the variables related to the hydrographical regions used have significant effects on water costs. Since the outcomes also reveal the existence of economies of scale, more concentration in the Portuguese water industry at the retail level would be beneficial. [ABSTRACT FROM AUTHOR]

The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid zone. Normally, evaporation and seepage are the main causes of water losses. For modeling water losses, a combination of Genetic Programming (GP), Penman-Monteith (PM) and Penman combination model for measurement of evapotranspiration, evaporation and seepage has been developed. The results were found to be varying depending on how the evaporation and seepage phenomena are modeled. These results show that that there is an improvement in reducing evapotranspiration, evaporation and seepage losses in arid and semi-arid region. [ABSTRACT FROM AUTHOR]

The multipurpose dam and reservoir “Bogovina” in the Crni Timok valley is one of several projects that have been initiated to improve water availability in Serbia. The site and height of the dam were initially proposed without consideration of risk factors such as water leakage or stability of the banks. Later, complex hydrogeological and speleological surveys and tests identified the potential of significant water losses from the reservoir area connected mainly to the karstic aquifer, and the nearby Bogovina cave system. The analyses show that once the reservoir is filled up, groundwater flow currently oriented towards the future reservoir would saturate the upper part of the karstified rocks, reactivate currently unsaturated pathways and form a reverse discharge outside of the reservoir area. In response to these findings, the dam design and technical details have been adapted accordingly: the dam height has been reduced by 9 m, and it is proposed that grouting and consolidation work be conducted both at the foundation of the dam and extensively on the embankments. It was concluded that although the proposed remedial measures cannot guarantee reservoir tightness, they can reduce the risk of large-scale leaking. [ABSTRACT FROM AUTHOR]

The paper presents the case of the Boljunčica reservoir, which began operation in 1973. It is situated on the Istria peninsula (Croatia). This is a multipurpose reservoir which was built in order to protect the downstream area from flood, to store water for irrigation, and to control sediment transport. The reservoir is situated on the contact zone between water impermeable Eocene flysch and deep Eocene and Cretaceous limestone. The bottom of the reservoir is covered partly by both flysch and quaternary deposits. Water losses from the reservoir bottom are so large that the main service intended for the reservoir, the storage of water for irrigation, is impossible. After every intensive precipitation, which occurs often in this region, the reservoir fills very quickly. The problem is that its retention of water is very short, and lasts only a few days. The water volume of the reservoir at the spillway altitude of 93.00 m a. s. l. is about 6.5 × 106 m3. Because of water losses from the reservoir bottom, the mean annual volume of water stored in it, during the period of 1977–2005 was only 0.5 × 106 m3, which is less than 8% of the full reservoir volume. On the reservoir bottom, many new swallow holes opened through the sediment cover after each time it filled and emptied with water. Special attention is paid to the groundwater level analyses. Interdisciplinary analyses and investigations of hydrological and hydrogeological factors causing the formation of swallow holes and water losses from the Boljunčica reservoir are discussed. The example given in this paper explains one unsuccessful case of building a reservoir in Dinaric karst, caused mainly due to insufficient geological, hydrogeological and hydrological investigations. In order to prevent water losses from the Boljunčica reservoir, very complex and expensive work needs to be done, but its success regarding the reasonable reduction of water losses from the reservoir is in question. [ABSTRACT FROM AUTHOR]

The present water policy debate is dominated by the 30 yr old mission to secure water supply and sanitation to all people. The water needed to produce a nutritionally acceptable diet for one person is however 70 times as large as the amount needed for domestic water supply. The food security dilemma is largest in arid climate regions, a situation constituting a formidable challenge. It is suggested that an additional 5 600 km³/yr of consumptive water use will be needed to produce an adequate amount of food by 2050 — i.e almost a doubling of today's consumptive use of 6800 km³/yr. Past misinterpretations and conceptual deficiencies show the importance of a shift in thinking. Combining the scale of the challenge and the time scale of the efforts to feed humanity and eradicate hunger leads to an impression of great urgency. This urgency strengthens the call for international research both for supporting agricultural upgrading, and for much better handling of issues of environmental sustainability. What stands out is the need of a new generation of water professionals, able to handle complexity and able to incorporate water implications of land use and of ecosystem health in integrated water resources management. It will for those reasons be essential and urgent to upgrade the educational system to producing this new generation. [ABSTRACT FROM AUTHOR]

A model to support decision systems regarding the quantification, location and opening adjustment of control valves in a network system, with the main objective to minimise pressures and consequently leakage levels is developed. This research work aims at a solution that allows simultaneously optimising the number of valves and its location, as well as valves opening adjustments for simulation in an extended period, dependently of the system characteristics. EPANET model is used for hydraulic network analysis and two operational models are developed based on the Genetic Algorithm optimisation method for pressure control, and consequently leakage reduction, since a leak is a pressure dependent function. In these two modules, this method has guaranteed an adequate technique performance, which demands a global evaluation of the system for different scenarios. A case study is presented to show the efficiency of the system by pressure control through valves management. [ABSTRACT FROM AUTHOR]

In semiarid areas producing corn in the State of Paraiba (Brazil), despite the social and economic importance of this culture associated with some types of stress mainly in semiarid regions, as well as the soils of these regions, which in many cases have a low organic matter content, generally < 1.5%, limiting the viability of the crop. The correct management of organic fertilization via fertigation is a possibility to minimize water losses by evaporation. The objective was to evaluate the vegetative growth and productive parameters of corn (Poaceae) fertigated with bovine biofertilizer under irrigation levels. The experiment was carried out under field conditions, in the locality of the agroecology sector (UEPB, Catole do Rocha, Paraiba, Brazil). The treatments were distributed in blocks at random with four replications, in a 3 × 5 split plot scheme, represented by three irrigation depths (60, 90, and 120% of ETc—crop's evapotranspiration) that when applied daily were considered the main plots and the subplots represented by the doses of biofertilizer (0, 20, 40, 60, and 80 mL plant−1) applied biweekly via fertigation, totaling to 60 experimental plants. Plants on water stress conditions inhibit their growth and production, but when associated with biofertilizer, they result in plants with greater productive potential in semiarid conditions. The blade of 120% of the ETc provided greater growth and production of corn compared with the layers of 60 and 90% of the ETc. The 50 ml plant−1 biofertilizer dose provided corn growth and production compatible with conventional cultivation. [ABSTRACT FROM AUTHOR]

Leaky water supply and sewer mains can become unmanaged sources of urban groundwater recharge and contamination posing environmental and health risks. Stable isotopes of water and hydrochemical tracer were applied to quantify water and sewage leakages in a shallow aquifer of a large Ukrainian city. Binary and ternary mixing models were used based on the d-excess and chloride concentrations of tap water, rural and urban groundwater to estimate fractions of natural recharge, urban seepage, volumes of water supply and sewage leakages in urban springs. Water supply leakages that recharge aquifer were ~ 3% (6.5 Mm3 a− 1) of the total water supply and strongly correlated with failures on the water infrastructure. Sewage leakages (1.4 Mm3 a− 1) to the aquifer were less in amount than water supply leakages, but induced nitrate and associated contaminants pollution risk of urban groundwater. The proposed method is useful for the pilot evaluation of urban groundwater recharge and contamination and can be applied in other regions worldwide to support the decision-making in water management. [ABSTRACT FROM AUTHOR]