Municipal Water Supply Research Articles

EXPLORING THEORETICAL CONSTRUCTS OF URBAN RESILIENCE THROUGH SMART WATER GRIDS: CASE STUDIES IN AFRICAN AND U.S. CITIES

This review paper explores the theoretical constructs of urban resilience through the lens of smart water grids, focusing on comparative insights between African and U.S. cities. Urban resilience, a critical concern in the face of climate change and urbanization, encompasses the capacity of urban systems to absorb, adapt, and recover from various shocks and stresses. Integrating advanced technologies such as sensors, smart meters, and data analytics, smart water grids emerge as innovative solutions to enhance urban resilience through improved water management. This paper synthesizes the literature on the intersections between urban resilience and smart water grids, highlighting theoretical constructs that emerge from integrating smart water technologies with urban resilience strategies. It discusses the implications of these constructs for urban planning and policy-making, considering socioeconomic, technological, and governance dimensions, and reflects on the importance of contextual factors. The paper identifies gaps in current theoretical and empirical understanding, suggesting areas for future research, including comparative studies and interdisciplinary approaches. By providing a comprehensive overview of how smart water grids contribute to urban resilience, this paper contributes to the broader discourse on sustainable urban development and the role of technology in addressing contemporary urban challenges.
 Keywords: Urban Resilience, Smart Water Grids, Climate Change Adaptation, Sustainable Urban Development.

Risk of Potential Invasive Non-Tuberculous Mycobacterial Infection in Major Cardiothoracic Surgeries.

Nontuberculous Mycobacteria (NTM) commonly colonise municipal water supplies and cause healthcare-associated outbreaks. Although the infections are rare, they are associated with high mortality. Aerosolization of NTM from colonised Heater cooler devices causes invasive infections in cardiac surgery patients. These units are widely used in open-chest heart surgery as an essential part of extracorporeal circulation but have been suggested as being a risk for infection. Water disinfection as well as effective engineering-related mitigation strategies should be designed to decrease the burden of NTM in the hospital water supply. Key Words: Nontuberculous Mycobacteria, Heater cooler devices, Endocarditis, Water, Cardiothoracic surgeries.

Contaminated Water and an Indication of Risk: Examining Microbial Contamination in the Water Used by Consumers and Commercial Growers in Fresh Produce Systems in Nepal

There has been limited research and understanding of the water quality in developing countries. Fresh produce consumed raw is nutrient-dense but is more susceptible to causing foodborne illness when contaminated water is used in production and consumption. There have been increasing reported incidences of foodborne outbreaks in Nepal linked to fresh produce contamination. However, water used in washing fresh produce by consumers and water used by growers or vendors is rarely tested. This research examines the source water used by consumers and growers in fresh produce systems in Nepal. To examine Escherichia coli (E. coli) detection as an indicator of contamination risk in water, we selected five major metropolitan cities for consumer households and ten districts representing commercial growers of vegetable growing areas of all seven provinces of Nepal. Altogether, we collected 394 water samples from randomly selected individual households: 156 from consumer households and 238 from growers or vendors. Results suggest that 59% of the water used in fresh produce systems is contaminated with E. coli in Nepal. On the water source used by consumers to wash fresh produce before consumption, we found that the dominant sources are the stored water in tanks or containers (46%) and municipal or communal supply water (39%)—which have E. coli prevalence rate of 66% and 57%, respectively. On the dominant sources of water used in fresh produce by growers or vendors, we found up to 88% of E. coli prevalence in the water they use. We also discussed the location or regional differences in contamination risks. This nationally represented study has implications for intervention policies and programs for safer food production and consumption practices in countries like Nepal where food safety is an emerging priority.

Advancing rainwater treatment technologies for irrigation of urban agriculture: A pathway toward innovation

Urban agriculture (UA) has emerged for local food security since the 1960s. However, the access to sufficient and safe irrigation water remains a significant constraint. Municipal water supply, though commonly used in UA practices, proves unsustainable due to high costs, intensive energy consumption, and limited availability in many vacant urban spaces. In contrast, rainwater harvesting (RWH) exhibits a potential as a non-traditional water supply for urban farming. This article aims to provide insights into the advantages and challenges associated with RWH for UA irrigation, analyze existing low-cost RWH treatment technologies, and identify a visionary way toward innovative, new-generation RWH treatment processes in UA practices. Despite a promising water source, harvested rainwater is challenged for crop irrigation owing to the presence of various contaminants (e.g., waterborne pathogens, potentially toxic metals and metalloids, and synthetic organic chemicals). While established RWH treatment processes (e.g., first flush diversion, sedimentation, solar disinfection, chlorination, UV irradiation, granular filtration, and bio-sand filtration) can remove certain pollutants, they cannot offer viable treatment solutions for UA irrigation due to different technical, economic, and social restrictions. Particularly, their capacity to reliably remove contaminants of emerging concern in runoff remains limited or uncertain. Consequently, it is essential to develop next-generation RWH treatment technologies tailored specifically for UA irrigation. To this end, three fundamental principles are recommended. First, the focus should be on technically viable, low-cost, simple-operation, and easy-maintenance treatment technologies capable of simultaneously addressing traditional and emerging runoff contaminants, while minimizing the production of undesirable treatment byproducts. Second, advancing the understanding of the water, soil, and crop interactions enables the development of “right” RWH treatment processes for irrigation of “right” crops at a “right” place. Last, crop nutrients, if possible, are retained in rainwater to reduce the nutrient demand for crop production. The insights and perspectives have far-reaching implications for water conservation, stormwater management, and the integration of water, food, and energy systems within the urban environment.

Machine learning applications for anomaly detection in Smart Water Metering Networks: A systematic review

The digitization of the water sector has led to the emergence of Smart Water Metering Networks (SWMNs), which enable automated and continuous water consumption measurement. However, challenges persist in efficiently managing and transmitting the vast amount of data generated by these networks. To address this, researchers have proposed anomaly detection techniques to identify and detect anomalies within SWMNs. In the realm of anomaly detection, a substantial body of research has emerged. However, there is a notable gap in the literature on a comprehensive synthesis of Machine Learning (ML) applications for anomaly detection in SWMNs. To bridge this knowledge gap, this study evaluated thirty-two research papers written between 2016 and 2023, focusing on ML applications for anomaly detection in smart water systems, smart water grids, water distribution networks, and water networks. From an initial pool of 725 research papers, those directly related to ML-based anomaly detection techniques were selected and analysed using both quantitative and qualitative data analysis. The study revealed that ML techniques such as k-Nearest Neighbors (kNN), Autoencoders, Density-Based Spatial Clustering of Applications with Noise (DBSCAN), Random Forest, Decision Trees, and Support Vector Machines (SVM) have made significant contributions to anomaly detection within these networks. Notably, researchers frequently employed multiple ML techniques to enhance accuracy. Performance metrics analysis demonstrated that F1 score, precision, accuracy, and recall were commonly used to assess the quality of ML anomaly detection techniques. This review aims to provide researchers with recommendations for selecting suitable ML anomaly detection techniques in SWMNs. The findings underscore the promising nature of ML applications for anomaly detection in SWMNs and highlight the need for further research in this area.

Effect of Community Water Service on Lead in Drinking Water in an Environmental Justice Community.

Multiple recent studies have found elevated lead (Pb) concentrations in tap water in U.S. homes relying on unregulated private wells. The main Pb source is dissolution from household plumbing, fixtures, and well components. Here, we leverage a natural experiment and citizen science approach to evaluate how extending community water service to an environmental justice community relying on private wells affects Pb in household water. We analyzed Pb in 260 first-draw kitchen tap water samples collected by individual homeowners over a 5-month period in residences that did and did not connect to the community system. Before the community water system was extended, 25% of homes had Pb > 15 μg/L (the U.S. regulatory action level for community water systems) in first-draw water samples. Pb was significantly correlated with nickel (ρ = 0.61), zinc (ρ = 0.50), and copper (ρ = 0.40), suggesting that corrosion of brass fittings and fixtures is the main Pb source. Among homes that connected to the community system, Pb decreased rapidly and was sustained at levels well below 15 μg/L over the study period. Overall, connecting to the municipal water supply was associated with a 92.5% decrease in first-draw tap water Pb.

Methane-carbon budget of a ferruginous meromictic lake and implications for marine methane dynamics on early Earth

Abstract The greenhouse gas methane (CH4) contributed to a warm climate that maintained liquid water and sustained Earth’s habitability in the Precambrian despite the faint young sun. The viability of methanogenesis (ME) in ferruginous environments, however, is debated, as iron reduction can potentially outcompete ME as a pathway of organic carbon remineralization (OCR). Here, we document that ME is a dominant OCR process in Brownie Lake, Minnesota (midwestern United States), which is a ferruginous (iron-rich, sulfate-poor) and meromictic (stratified with permanent anoxic bottom waters) system. We report ME accounting for ≥90% and >9% ± 7% of the anaerobic OCR in the water column and sediments, respectively, and an overall particulate organic carbon loading to CH4 conversion efficiency of ≥18% ± 7% in the anoxic zone of Brownie Lake. Our results, along with previous reports from ferruginous systems, suggest that even under low primary productivity in Precambrian oceans, the efficient conversion of organic carbon would have enabled marine CH4 to play a major role in early Earth’s biogeochemical evolution.

Long-term Evaluation of Culturable Fungi in a Natural Aging Biofilm on Galvanised Steel Surface

Fungi commonly found in municipal water can participate in natural biofilm formation on the surface of galvanised steel despite the toxic effect of zinc. Depending on the age of the biofilm, fungal diversity may vary. To examine this hypothesis, natural biofilm formation was allowed on galvanised steel surfaces over six months in a model recirculating water system. Fungal colonies with different morphologies were obtained monthly from biofilm and water samples and then identified by both morphological and molecular approaches. In addition, the biofilm layer was examined by electrochemical impedance spectroscopy (EIS) analysis and scanning electron microscopy (SEM). It was determined that fungi were included in the naturally aging biofilm formed on galvanised steel surfaces during the experiment. The diversity and the number of fungi in the biofilm and water changed over the experiment. All fungi isolated from the biofilm and water were found to be members of the Ascomycota phylum. F. oxysporum was the first fungus to be involved in the biofilm formation process and was one of the main inhabitants of the biofilm together with Penicillium spp. In addition, EIS data showed that the structure of the biofilm changed as it aged. The results of this study may lead to a better understanding of naturally aging biofilms involving fungi in municipal water systems, as well as the development of new strategies for effective disinfection of fungi based on biofilm age.

Degradation of fluoride in groundwater by electrochemical fixed bed system with bauxite: performance and synergistic catalytic mechanism.

Fluoride pollution in water has garnered significant attention worldwide. The issue of fluoride removal remains challenging in areas not covered by municipal water systems. The industrial aluminum electrode and natural bauxite coordinated defluorination system (IE-BA) have been employed for fluoride removal. The experiment investigated the effects of pH, current density, and inter-electrode mineral layer thickness on the defluorination process of IE-BA. Additionally, the study examined the treatment efficiency of IE-BA for simulated water with varying F- concentrations and assessed its long-term performance. The results demonstrate that the defluorination efficiency can reach 98.4% after optimization. Moreover, irrespective of different fluoride concentrations, the defluorination rate exceeds 95.2%. After 72 hours of continuous operation, the defluorination rate reached 91.9%. The effluent exhibited weak alkalinity with a pH of around 8.0, and the voltage increased by 2.0 V compared to the initial moment. By analyzing the characterization properties of minerals and flocs, this study puts forward the possible defluorination mechanism of the IE-BA system. The efficacy of the IE-BA system in fluoride removal from water was ultimately confirmed, demonstrating its advantages in terms of defluorination ability under different initial conditions and resistance to complex interference. This study demonstrates that the IE-BA technology is a promising approach for defluorination.

Water-based technologies for improving water quality at the point of use: A review.

Water safety concerns are increasing tremendously as a result of the rising population and environmental pollution. As a result, viable water treatment approaches need to be designed to meet the water consumption demands of the population, particularly in developing countries. The recent technological advances in water treatment and purification are well articulated in this review. The efficiency of the materials used for purification and their affordability for people living in rural and remote settlements in various parts of the world have been discussed. Water treatment techniques prior to the rapid advancement of science and technology included a variety of strategies such as coagulation/flocculation, filtration, disinfection, flotation and pH correction. The use of nanotechnology in water treatment and purification has modernized the purification process. Therefore, efficient removal of microbes such as bacteria and viruses are exquisitely accomplished. These technologies may include membrane filtration, ultraviolet irradiation, advanced oxidation ion-exchange and biological filtration technologies. Thus, nanotechnology allows for the fabrication of less expensive systems, allowing even low-income people to benefit from it. Most developing countries find these technologies particularly valuable because access to clean and safe water for drinking and residential needs is critical. This is because access to municipal water supplies is also difficult. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Geo-physical attributes of Shushunia’s aquifer, Chhatna block, Bankura district, West Bengal, India

Shushunia hill lies in a transitional zone of the South Singbhum Mobile Craton and northern Gondwana formation. The Shushunia hill appears like a porcupine peak and it has structural similarity to the Eastern Ghat. The Shushunia hill zone is an example of a contact spring. In the foothill zone, two perennial springs are observed. The study purely deals with its aquifer and water quality. Based on the present rock strata and the nature of the contact aquifer, its early condition has been assumed. The discharge of the confined aquifers occurs by leakage. The water temperature depicts the springs are not of geothermal origin. Shushunia's aquifer is the shallow flow system water table and it is the subdued replica of surface topography. The comparatively high discharge rate during post-monsoon indicates the fractured conduit-water seepage towards the aquifer. Moreover, twin-contact aquifers do not yield water uniformly. The perennial aquifer may act as a municipal water supply source for drinking purposes in the future.

Analyzing the possibility of using the internal energy of part of the Posušje municipality water supply system

Analyzing the possibility of using the internal energy of part of the Posušje municipality water supply system

Hydrogeological Analysis of Cretaceous and Tertiary Aquifers in Semiarid Sokoto Basin, Northwestern Nigeria: Implications for Sustainable Groundwater Development

Groundwater development in arid and semiarid regions is accelerated by expanded irrigation farming, industrialisation, and municipal water supply. This study provides a detailed hydrogeological analysis of sedimentary aquifers of the Sokoto basin, Northwestern Nigeria, for improved water resource development and management. Hydrogeological data, including static water level (Swl), pumping water level (Pwl), pumping test (Pt), and estimated yield (Ey), were analysed. A total of three hundred (300) observations on Swl, Pt, Pwl, Ey, and Hps were derived from boreholes and analysed using Factor analysis (FA) and Regression analysis (RA). Results showed that Gwandu Formation is the most prolific aquifer. Boreholes can yield more than 24000 litres per hour (L/h). This was followed by The Kalambaina limestone aquifer, which has the potential to yield about 15000 (L/h). However, the Taloka Formation is characterised by very poor aquifers in most of the basin, though along the Jega-Dogon Daji axis, boreholes can yield more than 24000 (L/h). Likewise, boreholes tapping the Wurno Formation can produce a maximum yield of 24000 (L/h). Estimated yields from boreholes were less than 1500 (L/h) from the Gundumi aquifer, and the maximum borehole yields were 17760 (L/h) in the Illo aquifer. Statistical modelling showed that all the analysed variables are significant concerning groundwater potentials and variability of borehole yields in the study area. Therefore, future groundwater resource development in the study area should be based on a proper analysis of the geological configurations of the Sokoto basin. This study provides an outlook on the groundwater potentials of the study area and aquifers that can provide a basis for sustainable groundwater development policy. Thus, the study has shown how multivariate and regression analysis can be used to study the hydrogeological conditions of a particular basin. Therefore, it is hoped that this study's findings will inspire other researchers to take a comparable approach.

Dynamics of the Water Table in the Rio Chiquito Sub-basin, Honduras

This research, led by the IHCIT in collaboration with the ADAPTARC project of SERNA/UNDP, forms a crucial part of the author's doctoral and master's thesis. Focusing on the Rio Chiquito sub-basin in Tegucigalpa, the capital of Honduras, it aims to offer a preliminary insight into the dynamics of the isophreatic curves as a technical tool for decision-makers. Despite its relatively small size, this sub-basin features a dramatic elevation change, ranging from 950 - 2200 meters above sea level over a 21km river length and with 30% urbanization. The study involved meticulous information management of over 100 wells, primarily used for human consumption, highlighting the community's dependence on groundwater. Given the intermittent and insufficient municipal water supply, this was especially critical, emphasizing groundwater's role in meeting basic needs and public health. The findings reveal underground water levels varying between 5 to 20 meters on average, with peaks up to 60 meters in the subbasin's lower western area. This underground flow aligns with the sub-basin geomorphology and surface dynamics, showing a gradient from 950 to 1200 meters in the middle-lower part, ascending to 2200 meters in the middle-upper region. Keywords: water table, aquifer, groundwater, sub-basin,

Blue Waters system and component reliability

SummaryThe Blue Waters system, installed in 2012 at NCSA, has the largest component count of any system Cray has built. Blue Waters includes a mix of dual‐socket CPU (XE) and single‐socket CPU, single GPU (XK) nodes. The primary storage is provided by Cray's Sonexion/ClusterStor Luster storage system delivering 35 PB (raw) storage at 1 TB/s. The statistical failure rates over time for each component including CPU, DIMM, GPU, disk drive, power supply, blower, etc and their impact on higher level failure rates for individual nodes and the systems as a whole are presented in detail, with a particular emphasis on identifying any increases in rate that might indicate the right‐side of the expected bathtub curve has been reached. Strategies employed by NCSA and Cray for minimizing the impact of component failure, such as the preemptive removal of suspect disk drives, are also presented.

Data‐driven modeling to enhance municipal water demand estimates in response to dynamic climate conditions

AbstractAltered precipitation and temperature patterns from a changing climate will affect supply, demand, and overall municipal water system operations throughout the arid western U.S. While supply forecasts leverage hydrological models to connect climate influences with surface water availability, demand forecasts typically estimate water use independent of climate and other externalities. Stemming from an increased focus on seasonal water demand management, we use the Salt Lake City, Utah municipal water system as a test bed to assess model accuracy versus complexity trade‐offs between simple climate‐independent econometric‐based models and complex climate‐sensitive data‐driven models to average to extreme wet and dry climate conditions—representative of a new climate normal. The climate‐independent model displayed low performance during extreme dry conditions with predictions exceeding 90% and 40% of the observed monthly and seasonal volumetric demands, respectively, which we attribute to insufficient model complexity. The climate‐sensitive models displayed greater accuracy in all conditions, with an ordinary least squares model demonstrating a measurable reduction in prediction bias (3.4% vs. −27.3%) and RMSE (74.0 lpcd vs. 294 lpcd) compared to the climate‐independent model. The climate‐sensitive workflow increased model accuracy and characterized climate‐demand interactions, demonstrating a novel tool to enhance water system management.

Public perceptions of rainwater harvesting (RWH): comparing users and non-users of RWH systems

ABSTRACT The UK’s abundant municipal water supply has resulted in slow progress with the uptake of rainwater harvesting (RWH) systems within the home. Research has indicated that exploring public preferences for domestic RWH are necessary for increasing demand. Here, we use explicit and implicit tests to investigate public perceptions of RWH for non-potable uses, and compare perceptions of respondents with and without domestic RWH systems. RWH is perceived positively by most respondents indicating an openness and acceptance of this technology (and/or lack of strong negative attitudes). Implicit attitudes are generally more positive than explicit, especially in respondents with RWH systems, implying that the positivity is deep-seated in their subconsciousness. We also reveal differences between subconscious (implicit) beliefs and practical difficulties (explicit opinions). Outdoor uses of rainwater are preferred, hence, more work in promoting indoor uses is needed to maximise the resource potential of UK rainfall and uptake of RWH systems.

O- and H-isotope record of Cape Town rainfall from 1996 to 2022: the effect of increasing temperature, and the ‘water crisis’ of 2015 to 2018

Abstract The O- and H-isotope composition of rainfall collected monthly at the University of Cape Town (UCT) between 2009 and 2022 has been added to a previously published data set from 1996 to 2008 to make a continuous 27 year record. Monthly rainfall over the 27 year period has a range in δD and δ18O values from -57 to +21‰ and -8.1 to +3.5‰, respectively, and shows limited but discernible temperature and amount effects. The 27 year rainfall record defines a Local Meteoric Water Line (LMWL) whose equation is δD = 5.96*δ18O + 7.00 (r = 0.88), a slight change from the LMWL of 1996 to 2009 (6.41*δ18O + 8.89). Annual rainfall at UCT has varied from ~992 mm (2017) to 1996 mm (2013), with no systematic change in annual rainfall amount (r = −0.16). However, from 2015 to 2022, the average annual rainfall of 1 145 mm has been below the 27 year average of 1 313 mm. Mean monthly temperature has increased from 1996 to 2022 (r = 0.53), and the weighted mean annual δD and δ18O values have increased by ~4‰ (r = 0.53) and ~0.5‰ (r = 0.64), respectively, over the 27 years. The UCT data and the data for 1961 to 1974 from Cape Town International Airport plot around the same LMWL, with an average deuterium excess (d-excess) of 13.78 and 12.95, respectively. Natural springs in the area plot close to the LMWL with an average d-excess of 14.15, whereas local well-point and borehole water samples generally plot below the LMWL with an average d-excess of 10.65. These differences can be explained by relatively rapid recharge of springs and slower recharge of groundwater, with the latter containing an additional component, that could either be rainwater that fell during a period of hotter drier climate or, more probably, municipal mains water. Long-term monitoring of groundwater and spring water as well as rainwater would be of great help in assessing the sustainability of groundwater use, among other important questions.

Modeling and application of ship traffic conflicts in nearshore waters with heavy traffic

Ensuring the safety of ship navigation is essential to support the sustainable development of the shipping industry, and maritime safety analysis has thus received much attention in the field of shipping. Traditionally, the safety evaluation is mostly performed with the help of accident data, which is thus limited by the insufficient amount of accident data and affects the evaluation effect. In order to overcome this limitation, a ship traffic conflict model is established, which consists of three sub-models: multi-risk ship domain model, ship traffic conflict preliminary screening model and ship traffic conflict detection model. The multi-risk ship domain model is the key foundation, combining the traditional ship domain model with the water traffic conflict severity model to fully consider the severity of ship traffic conflict. To validate the proposed model, three ships in the study waters are selected as the own ships, and the severity of traffic conflicts formed with their target ships within a certain conflict time range are analyzed separately. Then, the conflict datasets obtained from the training of the ship traffic conflict model are used to analyze the traffic conflict situation in the heavily trafficked waters near Tianjin Port. Specifically, the spatial distribution characteristics are obtained using the kernel density estimation (KDE) method and the water grid method, and the temporal distribution characteristics are verified with the help of the accident statistics method. The proposed ship conflict model can provide technical support for further research in the field of ship traffic conflict, and the experimental analysis results are of great significance for strengthening maritime traffic supervision.

Canada Source Watershed Polygons (Can-SWaP): A dataset for the protection of Canada’s municipal water supply

Over 80% of municipal (i.e., excluding industrial and agricultural) water use in Canada comes from streams, lakes, and reservoirs. These freshwater bodies and their catchments require adequate protection to secure drinking water supply for Canadians. Canada, like most countries, lacks a consolidated national dataset of municipal catchments, arguably due to gaps in data availability. Against this backdrop, we present the Canada Source Watershed Polygons dataset, or Can-SWaP. Can-SWaP was created using point locations of more than 3,300 municipal water licences defining rights to surface water withdrawal. Where possible, the resulting 1,574 catchments were assessed for accuracy in spatial coverage against provincial and local datasets. Each watershed in Can-SWaP has an estimated water volume used for municipal water purposes derived from licencing data, and several variables from RiverATLAS for investigating the integrity of surface drinking water sources in Canada. Furthermore, basing our method on the HydroSHEDS suite of global products offers a robust framework for the production of other national datasets following an established international standard.