To ensure the quantitative and qualitative safety of the drinking water supply to urban and rural areas, drinking water supply network managers are always concerned to improve the quality of the ...service provided to consumers and the continuity and quality of the water distributed. They are also concerned to ensure better management of all water supply systems. The development of computer software has made network modelling an essential part of the design and management of water supply systems. In this context, this study focuses on the operation of the Ain Regada water supply network. The simulation of the operation of the network in its current state is carried out using Epanet software.
•The diversification of water sources requires tools to optimize the blending options.•ACO approach was proposed and applied to optimize the blending of water sources.•Service outage, water ...conveyance and treatment costs were involved in the optimization.•The proposal improves the resilience and sustainability of urban water supplies.•The procedure achieves an optimal water blending at the overall lowest cost.
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Climate change and socioeconomic factors have increased the complexity of urban water supply systems. Thus, fresh water sources are being gradually diversified to improve the reliability and resilience of the systems. However, as the number of source blending options grows, optimization tools are needed to design drinking water supply systems that comply with indicators of cost, resilience, and water quality. This paper proposes a pioneering methodological approach, based on an ant-colony-optimization (ACO) algorithm, to optimize the blending of drinking water from different sources to minimize operational costs of a given system originating from a number of impaired water sources while complying with water quality standards. To evidence the potential of the ACO algorithm to solve such a system, a virtual case study was designed that considers eight fresh water sources, including seawater desalination and potable reuse. Seven scenarios were developed with different weightings to service outage, water conveyance and treatment costs while complying with water quality goals in regard to total organic carbon, nitrates, and total dissolved solids. It was shown that the cost per volumetric unit of water can vary considerably depending on the weightings of the three cost items. This paper provides a rigorous scientific approach to propose a methodology supporting the decision-making process of selecting a mixture of different sources to achieve the overall lowest system cost. Hence, this work contributes to improving the resilience and sustainability of urban water supplies.
To cope with present and future challenges, a growing number of water utilities in Sweden, Europe and elsewhere initiate various forms of inter-municipal cooperations creating a new regional level of ...drinking water governance. In order to reach viable decisions of alternative ways forward, there is an international consensus that sustainability needs to be addressed in water supply planning, design and decision-making. There are, however, few decision aids focusing on assessing the sustainability of inter-municipal cooperations and the inter-municipal policies and interventions that regional decision-makers are faced with. This paper presents a decision support model based on a combination of cost-benefit analysis and multi-criteria decision analysis for assessing the sustainability of regional water supply interventions, including formations of inter-municipal cooperations. The proposed decision support model integrates quantitative and semi-quantitative information on sustainability criteria. It provides a novel way of presenting monetized benefits and costs, capturing utilitarian aspects of alternative interventions, with non-monetized social and environmental effects, capturing aspects based in the deontological theories of moral ethics. The model is based on a probabilistic approach where uncertainties are defined by statistical probability distributions. A case study is used to exemplify and evaluate model application in decision situations regarding regionalization, (de)centralization, source water quality and redundancy. All evaluated alternatives were expected to contribute to a slightly improved social sustainability, whereas the results were more varying in the economic and environmental domains. A structured and transparent treatment of uncertainties facilitates a better understanding of the results as well as communication between decision-makers, stakeholders and the community.
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•A decision support model for water supply sustainability assessments is proposed.•Monetized and non-monetized values are handled in a structured and transparent way.•A probabilistic approach is used to enable uncertainty analysis of the results.•The model captures both utilitarian and deontological aspects of the alternatives.•A case study shows how decisions may affect the society, environment and economy.
The transformation of dissolved organic nitrogen (DON) in the drinking water treatment plants could be closely associated with nitrogenous disinfection by-product (N-DBP) formation. In this study, we ...have assessed the molecular transformation of DON and its impact on N-DBP formation in a full scale drinking water treatment plant. Based on the result of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis, DON compounds with low molecular weight (<1 kDa) were classified as CHON, CHON2 and CHON3 according to the number of nitrogen atoms. Via the analytical window of van Krevelen diagrams, we found that the molecular structural features of CHON, CHON2 and CHON3 were not altered before the chlorination process. In detail, the CHON2 and CHON3 compositions were concentrated on the regions assigned to a lignin-structure while CHON compositions were also distributed in other compounds including proteins, carbohydrates and tannin. Furthermore, CHON formation was more difficult to be removed before the V-filter process. For N-DBP, chlorine-containing DON (Cl-DON) composition was likely to be removed through flocculation and sedimentation processes, whereas N-nitrosamine compounds were removed in V-filter and biological activated carbon filter processes. The health risks of aromatic structure N-nitrosamines due to the pre-chlorination of the raw water should be further studied.
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•CHON formation was more difficult to be removed before V-filter process.•CHON2 and CHON3 compositions were closely associated with lignins structure•Effective mitigation of Cl-DON formation was achieved by flocculation-sedimentation
The utilization of groundwaters containing high levels of arsenic (As) for drinking water purposes presents major health and economic challenges for water utilities. One low-cost approach is to mix ...arsenic-rich groundwater (GW) with arsenic-free surface waters (SW) to achieve acceptable As levels. In this study we investigated the effect of different mixing ratios on water quality in an eastern Croatian water distribution system (WDS). To investigate the effects of mixing on drinking water quality, we measured the organic matter (OM) composition, disinfection byproduct (DBP) and metal concentrations in differently mixed ratios of GW and SW within the WDS. Fluorescence analysis revealed that the GW and SW had similar OM composition, with an almost equal ratio of humic- and protein-like OM throughout the WDS despite fluorescence indices revealing slightly different OM sources between the two water types. The tyrosine-like OM component was more variable, increasing during warmer months and towards the end of the WDS, most likely due to enhanced biofilm formation. Arsenic concentrations decreased to below 10 μg/L in the second half of the sampling campaign. Acceptable water quality was achieved after a period of destabilization and solubilization of loose deposits within the WDS resulting in their mobilization caused by water quality changes. Principal component and classification analysis, regression models and Spearman correlation coefficients revealed an association between As, OM and DBP concentrations with these correlations suggestive of their role in As mobilization in the WDS. Changing source waters, with different OM content and characteristics, corresponded to variable As release within the WDS.
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•Mixing ground-with surface waters decreased arsenic concentrations.•Water quality changes caused a destabilization of metals from pipe deposits.•Stable arsenic concentrations were achieved after six months of water mixing.•Tyrosine-like OM components were most variable in the WDS.•OM compositional changes altered DBP formation.
Socio-spatial Infrastructures Srivastwa, Amit Kumar; Kabra, Asmita
Ecology, Economy and Society, the INSEE Journal,
07/2023, Volume:
6, Issue:
2
Journal Article
Peer reviewed
This paper explores the social and spatial implications of drinking water infrastructures in rural southern Bihar. Hardiya, a multi-caste and multi-religion village, has a complex social arrangement. ...This village consists of original households, households resettled due to dam construction, and households resettled due to excessive fluoride contamination in groundwater. Excessive fluoride produces incidences of fluorosis among households, and historically, households have low access to clean drinking water. In response to the drinking water and public health crisis, multiple state, non-state, and transnational institutions intervened in Hardiya to provide safe technologies and infrastructures for clean drinking water. These twenty years of interventions have brought different technologies, institutions, and actors together to supply drinking water. However, these schemes are functioning inadequately on the ground, and access to clean water remains a big question amidst the development of drinking water infrastructures in Hardiya. This paper explores the dialectical relationship between drinking water infrastructures and social spaces, how both shape each other, through which assemblages, and what it renders. It explores the uneven outcomes of this technological intervention across different socio-spatial groups in Hardiya...
•Climate change impacts water sources’ vulnerability to contamination and shortages.•Key risk factors affecting drinking water along the impact chain are highlighted.•Emphasis is put on northern ...regions with changes of high kinetics and intensity.•Seasonal risks of water supply insecurity will increase in northern regions.•Under deep uncertainty, a paradigm change in assessing climate impacts is needed.
Climate change impacts the vulnerability of drinking water sources to contamination and water shortages. This review highlights key risk factors along the impact chain of climate change on water supply security, from precipitation and runoff to surface water quality and availability at drinking water intakes. How climate impacts water quantity (hydrology) and quality (fate, transport and loads of contaminants, via soils, forests, and urban water infrastructure) is examined across the scientific literature. An emphasis is placed on high-latitude regions, where the kinetics and intensity of projected changes are high. The province of Quebec, Canada, is used as a study area that covers diverse land and climate conditions, with extended relevance at a broader scale globally. This review aims at guiding researchers and water managers in considering the climate-related evolution of a range of threats when assessing the vulnerability of drinking water systems. It highlights how climate change increases the seasonal risks of water supply insecurity in a northern region, thereby increasing socioeconomic and public health risks. Accounting for multiple feedback effects is a major cause of uncertainty in assessing future risks in drinking water supplies. Under deep uncertainty, a paradigm change in assessing climate impacts on water supplies is needed.
Socio-spatial Infrastructures Amit Kumar Srivastwa; Asmita Kabra
Ecology, Economy and Society, the INSEE Journal,
07/2023, Volume:
6, Issue:
2
Journal Article
Peer reviewed
Open access
This paper explores the social and spatial implications of drinking water infrastructures in rural southern Bihar. Hardiya, a multi-caste and multi-religion village, has a complex social arrangement. ...This village consists of original households, households resettled due to dam construction, and households resettled due to excessive fluoride contamination in groundwater. Excessive fluoride produces incidences of fluorosis among households, and historically, households have low access to clean drinking water. In response to the drinking water and public health crisis, multiple state, non-state, and transnational institutions intervened in Hardiya to provide safe technologies and infrastructures for clean drinking water. These twenty years of interventions have brought different technologies, institutions, and actors together to supply drinking water. However, these schemes are functioning inadequately on the ground, and access to clean water remains a big question amidst the development of drinking water infrastructures in Hardiya. This paper explores the dialectical relationship between drinking water infrastructures and social spaces, how both shape each other, through which assemblages, and what it renders. It explores the uneven outcomes of this technological intervention across different socio-spatial groups in Hardiya...
As drinking water supply systems plan for sustainable management practices, impacts from future water quality and climate changes are a major concern. This study aims to understand the intraannual ...changes of energy consumption for water treatment, investigate the relative importance of water quality and climate indicators on energy consumption for water treatment, and predict the effects of climate change on the embodied energy of treated, potable water at two municipal drinking water systems located in the northeast and southeast US. To achieve this goal, a life cycle assessment was first performed to quantify the monthly energy consumption in the two drinking water systems. Regression and relative importance analyses were then performed between climate indicators, raw water quality indicators, and chemical and energy usages in the treatment processes to determine their correlations. These relationships were then used to project changes in embodied energy associated with the plants' processes, and the results were compared between the two regions. The projections of the southeastern US water plant were for an increase in energy demand resulted from an increase of treatment chemical usages. The northeastern US plant was projected to decrease its energy demand due to a reduced demand for heating the plant's infrastructure. The findings indicate that geographic location and treatment process may determine the way climate change affects drinking water systems.
•Local climates result in differing seasonal water demand and energy use patterns.•Water quality resulted in 3 times energy difference in two surface water systems.•Climate and water quality explain 40–55% of intraannual embodied energy variations.•Energy use by water systems can have opposite trends under future climate change.•Energy use by water peaks at similar times of a year as other types of energy uses.
Water supply facilities that supply water to more than 100 residents or supply more than 20 m3 of water per day are called specified privately owned water supply systems (SPOWs). SPOWs and small ...water systems require proper maintenance and management at their facilities, especially small water systems including private drinking water wells, where many water quality incidents involving health hazards have occurred. Most water quality incidents in SPOWs occurred in facilities where the groundwater was used as raw water, requiring thorough water quality management by those who install SPOWs. In addition to recent water quality incidents associated with microbial contamination in drinking water storage tanks, the incident at a building of university hospital is introduced. In October 2021, methemoglobinemia developed in 10 of 17 infants in the neonatal intensive care unit of the university hospital. It was found that these infants had been fed milk that had been prepared in the kitchen within the building of university hospital. It was finally proved that the water was contaminated with nitrite contained in the anticorrosion agent used in the air-conditioning system due to cross-connection.
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