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Zhong D, Zhang J, Ma J, Ma W. Reshaping water distribution topology from the carbon emission reduction perspective: An exploratory analysis of water distribution reliability. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 370:122417. [PMID: 39260280 DOI: 10.1016/j.jenvman.2024.122417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 07/05/2024] [Accepted: 09/02/2024] [Indexed: 09/13/2024]
Abstract
As urban economies continue to evolve, the water distribution networks (WDNs) are expanding in scale and becoming more interconnected, leading to increased carbon emissions from operations and maintenance. Consequently, enhancing the stability and safety of WDNs while saving energy has emerged as a primary research focus. This study abandoned the original use of high economic costs for post-maintenance of WDNs. Instead, it reshaped the traditional water distribution topology to form a dynamic, storable, energy-efficient "WDN self-help" model. Drawing inspiration from the "deep tunnel" project in drainage systems, the proposal was to leverage underground spaces to create a deep aqueduct (DA) complementing the traditional WDN, forming a three-dimensional (3D) WDN. Hydraulic and water quality analyses of varying scales of the 3D WDN model demonstrated its superior ability to equalize node pressures, reduce pipeline head losses, and maintain water quality for end-users. Reliability assessments of the 3D WDN revealed enhanced system robustness for medium-to large-scale distributions, while energy consumption analyses indicated a significant increase in water supply energy utilization and significant long-term reductions in carbon footprint. A practical case study was presented to validate the effectiveness of the 3D WDN concept, confirming its ability to reliably distribute water even in the event of a failure. Finally, an estimate of the retrofit cost and the static payback period of the 3D WDN was conducted. This study aims to provide a theoretical reference for the renovation of water supply projects or the optimal design of new WDNs in the context of carbon neutrality.
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Affiliation(s)
- Dan Zhong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jingna Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Wencheng Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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2
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Zambrana JV, Bustos Carrillo FA, Ojeda S, Lopez Mercado B, Latta K, Schiller A, Kuan G, Gordon A, Reingold A, Harris E. Epidemiologic Features of Acute Pediatric Diarrhea in Managua, Nicaragua, from 2011 to 2019. Am J Trop Med Hyg 2022; 106:1757-1764. [PMID: 35895434 PMCID: PMC9209918 DOI: 10.4269/ajtmh.21-0793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 02/18/2022] [Indexed: 11/12/2022] Open
Abstract
Diarrhea remains a leading cause of death in children in developing countries, including Nicaragua, but little is known about patterns of diarrhea occurrence in Central America over long periods of time. The purpose of this study was to determine the incidence, risk factors, long-term trends, and seasonality of diarrhea in children age 2 to 14 years in Managua, Nicaragua. From 2011 to 2019, we examined episodes of diarrhea among 6,485 children who participated in a prospective cohort study and presented for care in a primary care facility. We performed a longitudinal analysis considering time-varying variables and the intra-subject correlation of outcomes. In addition, we analyzed the weekly incidence of diarrhea, applying seasonal trend decomposition to extract secular and seasonal patterns. The overall incidence rate of diarrhea was 133.4 episodes per 1,000 person-years (95% CI, 128.3–138.7). We observed a slight increase in the incidence of diarrhea from 2011 to 2019. Younger age was the strongest predictor of the risk of diarrhea, and incidence increased with every additional hour without running water in the household per day. Diarrhea incidence in Managua was seasonal, with high peaks each year between May and July. Despite reductions in childhood mortality since 1990 in Nicaragua, diarrheal morbidity remains a major problem in Managua.
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Affiliation(s)
| | - Fausto Andres Bustos Carrillo
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California
| | - Sergio Ojeda
- Sustainable Sciences Institute, Managua, Nicaragua
| | | | - Krista Latta
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Amy Schiller
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Guillermina Kuan
- Centro de Salud Sócrates Flores Vivas, Ministry of Health, Managua, Nicaragua
| | - Aubree Gordon
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Arthur Reingold
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California
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3
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Abstract
Intermittent water supply systems (IWSSs) are prevalent in most developing countries and some developed ones. Their usage is driven by necessity rather than as a principal objective, mostly due to technical and economic deficiencies. Major health risks and socio-economic inequities are associated with such systems. Their impacts are aggravated by climate changes and the COVID-19 crisis. These are likely to have profound implications on progress toward advancing sustainable development goals (SDGs). Motivated by providing a comprehensive overview of global knowledge on IWSSs, the present work proposed to track and analyze research works on IWSSs utilizing bibliometric techniques and visual mapping tools. This includes investigating the trends and growth trajectories of research works on IWSSs and analyzing the various approaches proposed to expand our understanding with respect to the management, modeling, optimization, and impacts of IWSSs. The national and international contributions and collaboration figures are further analyzed at country, institution, author, and source levels. This analysis indicates that research works conducted on IWSSs have certain expectations in terms of productivity (total global productivity; 197 documents). The United States was the best country in terms of productivity (58 documents; 29.4%), while the Water Switzerland journal was the most productive journal (19 documents; 9.6%). The impacts of IWSSs on health and well-being have attracted considerable attention. The outcomes showed deep and justified worries in relation to the transition from intermittent to continuous supply, equity, and mitigating the health risks associated with IWSSs in the foreseen future. The utilization of artificial intelligence techniques and expert systems will drive and shape future IWSS-related research activities. Therefore, investments in this regard are crucial.
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Salehi M. Global water shortage and potable water safety; Today's concern and tomorrow's crisis. ENVIRONMENT INTERNATIONAL 2022; 158:106936. [PMID: 34655888 DOI: 10.1016/j.envint.2021.106936] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 05/28/2023]
Abstract
Climate change, severe droughts, population growth, demand increase, and poor management during the recent decades have further stressed the scarce freshwater resources worldwide and resulted in severe water shortages in many regions. The water utilities address the water shortage by providing alternative source of water, augment the supplied water, supply intermittently, and even bulk water delivery under severe water shortage conditions. On the other hand, many households store water in building storage tanks to cope with insufficient delivery of potable water due to frequent interruptions. All these practices could pose crucial risks to the chemical and microbiological quality of the water. However, consistent monitoring and implementation of mitigation strategies could lower the potential risks associated with these practices. It is critical to identify the potential hazards resulting from the alternative water supplies and distribution practices to develop temporary and long-term monitoring and mitigation plans and reduce the microbial and chemical contamination of potable water delivered to the consumers. This paper provides a holistic review of the significant hazards associated with the practices employed by the water utilities and water consumers to alleviate the potable water shortage and discusses the required monitoring and mitigation practices.
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Affiliation(s)
- Maryam Salehi
- Department of Civil Engineering, The University of Memphis, 3815 Central Avenue, 108C Engineering Science Bldg, Memphis, TN 38152, United States.
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5
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Molinero J, Cipriani-Avila I, Barrado M. Heavy metal concentrations in rivers and drinking water of Esmeraldas (Ecuador) under an intermittent water supply service. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:775. [PMID: 34741668 DOI: 10.1007/s10661-021-09579-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Universal access to safe water is a major global goal, but these efforts could be at stake because drinking water sources are becoming polluted in many developing countries. Chlorine, major ions, and heavy metals were measured in rivers and drinking water of Esmeraldas because potential pollution sources raise concerns about the quality of the water supply, and because users have developed strategies to cope with water shortages including collecting river water and water distributed by tankers, storing water at home, and consuming commercial bottled water. We sampled water from the water distribution system (WDS) and the Esmeraldas and Teaone rivers including the intake to the potabilization plant, water distributed by tankers, and commercial bottled water. Most of the samples collected from the Esmeraldas and Teaone rivers, the WDS, and tankers complied with drinking water standards, but higher concentration of cadmium and other metals in the eastern part of the city is an indication of corrosion inside the WDS. Commercial bottled and WDS water showed similar heavy metal concentrations, but regular consumption of some brands may lead to higher exposure to arsenic and mineral deficiencies. Chlorine concentrations in the water supplied by the WDS were below the values required for safe disinfection, and in-house chlorination is uncommon in the city. Strengthening pollution control in the Esmeraldas river, monitoring corrosion of the WDS, and promoting point-use chlorination and better water handling practices are required to secure a safer water supply in the long term.
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Affiliation(s)
- Jon Molinero
- Escuela de Gestión Ambiental, Pontificia Universidad Católica del Ecuador Sede Esmeraldas, Espejo y Subida a Santa Cruz, 080150, Esmeraldas, Ecuador.
| | - Isabel Cipriani-Avila
- Escuela de Química, Pontificia Universidad Católica del Ecuador, 12 de octubre 1076, 170525, Quito, Ecuador
| | - Miren Barrado
- Escuela de Gestión Ambiental, Pontificia Universidad Católica del Ecuador Sede Esmeraldas, Espejo y Subida a Santa Cruz, 080150, Esmeraldas, Ecuador
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6
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Meyer DD, Khari J, Whittle AJ, Slocum AH. Effects of hydraulically disconnecting consumer pumps in an intermittent water supply. WATER RESEARCH X 2021; 12:100107. [PMID: 34345814 PMCID: PMC8319575 DOI: 10.1016/j.wroa.2021.100107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 06/12/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
We estimate 250 million people receive water using private pumps connected directly to intermittently pressurized distribution networks. Yet no previous studies have quantified the presumed effects of these pumps. In this paper, we investigate the effects of installing pressure-sustaining valves at consumer connections. These valves mimic pump disconnection by restricting flow. Installing these valves during the dry season at 94% of connections in an affluent neighborhood in Delhi, India, cut the prevalence of samples with turbidity > 4 NTU by two thirds. But considering the poor reputation of pumps, installed valves had surprisingly small average effects on turbidity (-8%; p<0.01) and free chlorine (+0.05 mg/L; p<0.001; N = 1,031). These effects were much smaller than the high variability in water quality supplied to both control and valve-installed neighborhoods. Site-specific responses to this variability could have confounded our results. At the study site, installed valves increased network pressure during 88% of the typical supply window; valves had a maximum pressure effect of +0.62 m (95% CI [0.54, 0.71]; a 40% increase vs. control). Further research is needed to generalize beyond our study site. Nevertheless, this paper provides unique evidence showing how the deployed valves mitigated pump effects, increased network pressure and improved water safety.
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Affiliation(s)
- David D.J. Meyer
- Mechanical Engineering, MIT, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - J. Khari
- Anonymous Partner Utility, Delhi, India
| | - Andrew J. Whittle
- Civil and Environmental Engineering, MIT, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Alexander H. Slocum
- Mechanical Engineering, MIT, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
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7
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Bivins A, Lowry S, Wankhede S, Hajare R, Murphy HM, Borchardt M, Labhasetwar P, Brown J. Microbial water quality improvement associated with transitioning from intermittent to continuous water supply in Nagpur, India. WATER RESEARCH 2021; 201:117301. [PMID: 34139512 DOI: 10.1016/j.watres.2021.117301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/12/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
Nearly half a billion people living in Indian cities receive their drinking water from an intermittent water supply (IWS), which can be associated with degraded water quality and risk of waterborne disease. The municipal water supply in Nagpur, India is transitioning from intermittent to continuous supply in phases. We conducted cross-sectional sampling to compare microbial water quality under IWS and continuous water supply (CWS) in Nagpur. In 2015 and 2017, we collected 146 grab samples and 90 large-volume dead-end ultrafiltration (DEUF) samples (total volume: 6,925 liters). In addition to measuring traditional water quality parameters, we also assayed DEUF samples by droplet digital PCR (ddPCR) for waterborne pathogen gene targets. At household taps served by IWS, we detected targets from enterotoxigenic E. coli, Shigella spp./enteroinvasive E. coli, norovirus GI and GII, adenovirus A-F, Cryptosporidium spp., and Giardia duodenalis. We observed a significant increase in the proportion of grab samples positive for culturable E. coli (p = 0.0007) and DEUF concentrates positive for waterborne pathogen gene targets (p = 0.0098) at household taps served by IWS compared to those served by CWS. IWS continues to be associated with fecal contamination, and, in this study, with increased prevalence of molecular evidence of waterborne pathogens. These findings add mounting evidence that, despite the presence of piped on premise infrastructure, IWS is less likely to meet the requirements for safely-managed drinking water as defined by the Sustainable Development Goals. Importantly, these findings demonstrate the transition from IWS to CWS in Nagpur is yielding meaningful improvements in microbial water quality.
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Affiliation(s)
- Aaron Bivins
- Environmental Change Initiative, University of Notre Dame, 721 Flanner Hall, Notre Dame, IN 46556, USA; Department of Civil & Environmental Engineering & Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556, USA
| | - Sarah Lowry
- School of Civil & Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, USA
| | - Sonal Wankhede
- Director's Research Cell, Council of Scientific and Industrial Research, National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur, India
| | - Rajashree Hajare
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Heather M Murphy
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Mark Borchardt
- Agricultural Research Service, U.S. Dept of Agriculture, 2615 Yellowstone Drive, Marshfield, WI 54449, USA
| | - Pawan Labhasetwar
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 135 Dauer Drive, Chapel Hill NC 27599-7431, USA..
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8
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van den Berg H, Quaye MN, Nguluve E, Schijven J, Ferrero G. Effect of operational strategies on microbial water quality in small scale intermittent water supply systems: The case of Moamba, Mozambique. Int J Hyg Environ Health 2021; 236:113794. [PMID: 34147023 DOI: 10.1016/j.ijheh.2021.113794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/14/2021] [Accepted: 06/09/2021] [Indexed: 10/21/2022]
Abstract
Intermittent drinking water supply affects the health of over 300 million people globally. In Mozambique, it is largely practiced in cities and small towns. This results in frequent microbial contamination of the supplied drinking water posing a health risk to consumers. In Moamba, a small town in Southern Mozambique with 2,500 water connections, the impact of changes in operational strategies, namely increased chlorine dosage, increased supply duration and first-flush, on the microbial water quality was studied to determine best practices. To that aim, water quality monitoring was enhanced to provide sufficient data on the microbial contamination from 452 samples under the different strategies. The water at the outlet of the water treatment plant during all strategies was free of E. coli complying to the national standards. However, E. coli could be detected at household level. By increasing the chlorine dosage, the number of samples that showed E. coli absence increased at the two sampling locations in the distribution network: in Cimento from 72% to 83% and in Matadouro from 52% to 86%. Modifying the number and duration of supply cycles showed a different impact on the water quality at both locations in the distribution network. A positive effect was shown in Cimento, where the mean concentrations decreased slightly from 0.54 to 0.23 CFU/100 mL and 16.7 to 7.3 CFU/100 mL for E. coli and total coliforms respectively. The percentage of samples positive for bacteria was, however, similar. In contrast, a negative effect was shown in Matadouro where the percentage of positive samples increased and the mean bacterial concentrations increased slightly: E. coli from 0.9 to 1.5 CFU/100 mL and total coliforms 17.6 to 23.0 CFU/100 mL. Enhanced water quality monitoring improved operational strategies safeguarding the microbial water quality. The E. coli contamination of the drinking water at household level could point at recontamination in the distribution or unsafe hygienic practices at household level. Presence of faecal contamination at household level indicates potential presence of pathogens posing a health risk to consumers. Increasing chlorine dosage ensured good microbiological drinking water quality but changing the number of supply cycles had no such effect.
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Affiliation(s)
- Harold van den Berg
- National Institute for Public Health and the Environment (RIVM), WHO Collaborating Centre for Risk Assessment of Pathogens in Food and Water, P.O. Box 1, 3721, MA, Bilthoven, the Netherlands.
| | - Michael Nii Quaye
- IHE Delft Institute for Water Education, Westvest 7, 2611, AX, Delft, the Netherlands.
| | - Eugenia Nguluve
- Collins Ltd, Rua Joseph Ki-zerbo, N. 119 Bairro da Sommerschield, Maputo, Mozambique.
| | - Jack Schijven
- National Institute for Public Health and the Environment (RIVM), WHO Collaborating Centre for Risk Assessment of Pathogens in Food and Water, P.O. Box 1, 3721, MA, Bilthoven, the Netherlands; Earth Sciences, University of Utrecht, Princetonlaan 8a, 3584, CB, Utrecht, the Netherlands.
| | - Giuliana Ferrero
- IHE Delft Institute for Water Education, Westvest 7, 2611, AX, Delft, the Netherlands.
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9
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Zhu NJ, Ghosh S, Edwards MA, Pruden A. Interplay of Biologically Active Carbon Filtration and Chlorine-Based Disinfection in Mitigating the Dissemination of Antibiotic Resistance Genes in Water Reuse Distribution Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8329-8340. [PMID: 34080846 DOI: 10.1021/acs.est.1c01199] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Appropriate management approaches are needed to minimize the proliferation of antibiotic resistance genes (ARGs) in reclaimed water distribution systems (RWDSs). Six laboratory-scale RWDSs were operated over 3 years receiving influent with or without biologically active carbon (BAC) filtration + chlorination, chloramination, or no disinfectant residual. Shotgun metagenomic sequencing was applied toward comprehensive characterization of resistomes, focusing on total ARGs, ARG mobility, and specific ARGs of clinical concern. ARGs such as aadA, bacA, blaOXA, mphE, msrE, sul1, and sul2 were found to be particularly sensitive to varying RWDS conditions. BAC filtration with chlorination most effectively achieved and maintained the lowest levels of nearly all metagenomically derived antibiotic resistance indicators. However, BAC filtration or addition of residual disinfectants alone tended to increase these indicators. Biofilm and sediment compartments harbored ARGs in disinfected systems, presenting a concern for their release to bulk water. Relative and absolute abundances of most ARGs tended to decrease with water age (up to 5 days), with notable exceptions in BAC-filtered chloraminated and no residual systems. Superchlorination of unfiltered water especially raised concerns in terms of elevation of clinically relevant and mobile ARGs. This study revealed that BAC filtration and disinfection must be carefully coordinated in order to effectively mitigate ARG dissemination via RWDSs.
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Affiliation(s)
- Ni Joyce Zhu
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Sudeshna Ghosh
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Marc A Edwards
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Amy Pruden
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
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10
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Haider H, Alkhowaiter MH, Shafiquzzaman MD, Alresheedi M, AlSaleem SS, Ghumman AR. Source to Tap Risk Assessment for Intermittent Water Supply Systems in Arid Regions: An Integrated FTA-Fuzzy FMEA Methodology. ENVIRONMENTAL MANAGEMENT 2021; 67:324-341. [PMID: 33410919 DOI: 10.1007/s00267-020-01400-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Water utilities in arid regions deal with multifaceted issues of natural groundwater contamination, high treatment costs, and low water rates. These utilities rely on intermittent supplies resulting in numerous water quality failures at source, treatment, distribution, and in-house plumbing systems. The present research presents an inclusive risk assessment methodology for managing water quality from source to tap. Three-year monitoring data for turbidity, TDS, pH, iron, ammonia, nitrates, residual chlorine, Coliform group, E. coli, and Fecal Streptococci identified the root causes of failures. The cause-effect relationships in the form of a fault tree were solved using multiple failure modes and effect analysis (FMEA) to handle both the Boolean operations. The fuzzy sets addressed the uncertainties associated with data limitations in calculating exceedance probabilities (Pe) and vagueness in expert opinion for subjective evaluation of severity and detectability. The methodology was applied on a smaller system serving 18,000 consumers in Qassim, Saudi Arabia. Potable supplied water underwent reoccurrence of TDS (Pe = 20%), turbidity (Pe = 10%), and Fe (Pe = 2%) failures in distribution that further increased up to 44%, 33%, and 11% at the consumer end. The Pe for residual chlorine failure soared up to 89%. Economic controls reduced the cumulative risk to 50%, while the shift to continuous supply can limit the remaining failures under the acceptable risk. The framework will help utilities manage water quality in intermittent systems from source to tap in Saudi Arabia, the Gulf, and elsewhere.
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Affiliation(s)
- Husnain Haider
- Department of Civil Engineering, College of Engineering, Qassim University, Buraydah, Qassim, 51452, Saudi Arabia.
| | - Mohammed Hammed Alkhowaiter
- Graduate student, Department of Civil Engineering, College of Engineering, Qassim University, Buraydah, Qassim, 51452, Saudi Arabia
- Real Estate Development Fund, AlRass Brach, AlRass, Qassim, 52719, Saudi Arabia
| | - M D Shafiquzzaman
- Department of Civil Engineering, College of Engineering, Qassim University, Buraydah, Qassim, 51452, Saudi Arabia
| | - Mohammad Alresheedi
- Department of Civil Engineering, College of Engineering, Qassim University, Buraydah, Qassim, 51452, Saudi Arabia
| | - Saleem S AlSaleem
- Department of Civil Engineering, College of Engineering, Qassim University, Buraydah, Qassim, 51452, Saudi Arabia
| | - Abdul Razzaq Ghumman
- Department of Civil Engineering, College of Engineering, Qassim University, Buraydah, Qassim, 51452, Saudi Arabia
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11
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Zhang H, Xu L, Huang T, Liu X, Miao Y, Liu K, Qian X. Indoor heating triggers bacterial ecological links with tap water stagnation during winter: Novel insights into bacterial abundance, community metabolic activity and interactions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 269:116094. [PMID: 33234370 DOI: 10.1016/j.envpol.2020.116094] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 06/11/2023]
Abstract
The overnight stagnation of tap water in plumbing systems can lead to water quality deterioration. Meanwhile, the indoor heating can improve the indoor temperature in cold areas during winter, which may affect the quality of tap water during stagnation. However, indoor heating drives bacterial ecological links with tap water stagnation during winter are not well understood. The results indicated that the water temperature increased significantly after stagnation during indoor heating periods. Moreover, the average intact cell number and total adenosine triphosphate (ATP) concentration increased 1.53-fold and 1.35-fold after stagnation, respectively (P < 0.01). In addition, the increase in the ATP per cell number indicated that the combined effects of stagnation and indoor heating could enhance the bacterial activity. Biolog data showed that the bacterial community metabolic capacity was significantly higher in stagnant water than that of fresh water. Co-occurrence networks suggested that the bacterial metabolic profile changed after stagnation during the heating periods. DNA analysis indicated that the composition of the bacterial community changed dramatically after stagnation. The abundances of potential pathogens such as Mycobacterium sp. and Pseudomonas sp. also increased after stagnation. These results will give novel insights on comprehensive understanding the combined effects of indoor heating and overnight stagnation on the water bacterial community ecology of plumbing systems, and provide a scientific basis for tap water quality management after overnight stagnation during the indoor heating periods.
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Affiliation(s)
- Haihan Zhang
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
| | - Lei Xu
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Tinglin Huang
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Xiang Liu
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Yutian Miao
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Kaiwen Liu
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Xuming Qian
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
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12
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Abstract
Water utilities should monitor their nonrevenue water (NRW) levels properly to manage water losses and sustain water services. However, monitoring NRW is problematic in an intermittent water supply regime. This is because more supplied water to users imposes higher volumes of NRW, and supplying significantly less water results in an unmet water demand but interestingly less NRW. This study investigates the influence of the amount of water supplied to a distribution system on the reported level of NRW. The volume and indicators of NRW all vary with variations in the system input volume (SIV). This is even more critical for monitoring NRW for systems shifting from intermittent to continuous supply. To enable meaningful monitoring, the NRW volume should be normalised. Addressing that, this research proposes two normalisation approaches: regression analysis and average supply time adjustment. Analysis of the NRW performance indicators showed that regression analysis enables the monitoring of NRW and tracking its progression in an individual system only, but not for a comparison with other systems. For comparing (or benchmarking) a water system to other systems with different supply patterns, the average supply time adjustment should be used. However, this approach presents significant uncertainties when the average supply time is less than eight hours per day.
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Understanding the impacts of intermittent supply on the drinking water microbiome. Curr Opin Biotechnol 2019; 57:167-174. [PMID: 31100615 DOI: 10.1016/j.copbio.2019.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 04/14/2019] [Accepted: 04/15/2019] [Indexed: 11/21/2022]
Abstract
Increasing access to piped water in low-income and middle-income countries combined with the many factors that threaten our drinking water supply infrastructure mean that intermittent water supply (IWS) will remain a common practice around the world. Common features of IWS include water stagnation, pipe drainage, intrusion, backflow, first flush events, and household storage. IWS has been shown to cause degradation as measured by traditional microbial water quality indicators. In this review, we build on new insights into the microbial ecology of continuous water supply systems revealed by sequencing methods to speculate about how intermittent supply conditions may further influence the drinking water microbiome, and identify priorities for future research.
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Liu L, Xing X, Hu C, Wang H. One-year survey of opportunistic premise plumbing pathogens and free-living amoebae in the tap-water of one northern city of China. J Environ Sci (China) 2019; 77:20-31. [PMID: 30573084 DOI: 10.1016/j.jes.2018.04.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 04/20/2018] [Accepted: 04/20/2018] [Indexed: 05/21/2023]
Abstract
In this study, qPCR was used to quantify opportunistic premise plumbing pathogens (OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated that the average numbers of gene copies of Legionella spp. and Mycobacterium spp. were significantly higher than those of Aeromonas spp. (p < 0.05). Legionella spp. and Mycobacterium spp. were 100% (44/44) positively detected while P. aeruginosa and Aeromonas spp. were 79.54% (35/44) and 77.27% (34/44) positively detected. Legionella pneumophila was only detected in 4 samples (4/44), demonstrating its occasional occurrence. No Mycobacterium avium or Naegleria fowleri was detected in any of the samples. The average gene copy numbers of target OPPPs were the highest in summer, suggesting seasonal prevalence of OPPPs. Average gene copy numbers of OPPPs in the taps of low-use-frequency were higher than in taps of high-use-frequency, but the difference was not significant for some OPPPs (p > 0.05). Moderate negative correlations between the chlorine concentration and the gene copy numbers of OPPPs were observed by Spearman analysis (rs ranged from -0.311 to -0.710, p < 0.05). However, no significant correlations existed between OPPPs and AOC, BDOC, or turbidity. Moderate positive correlations were observed between the target microorganisms, especially for Acanthamoeba spp., through Spearman analysis (p < 0.05). Based on our studies, it is proposed that disinfectant concentration, season, taps with different-use frequency, OPPP species, and potential microbial correlations should be considered for control of OPPPs in tap water.
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Affiliation(s)
- Lizhong Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xueci Xing
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Chun Hu
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China
| | - Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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15
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Bacterial Contamination of Drinking Water in Guadalajara, Mexico. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 16:ijerph16010067. [PMID: 30591690 PMCID: PMC6339170 DOI: 10.3390/ijerph16010067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 12/21/2018] [Accepted: 12/22/2018] [Indexed: 11/17/2022]
Abstract
In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Metropolitan Zone of Guadalajara is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and Escherichia coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.
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Brooks YM, Tenorio-Moncada EA, Gohil N, Yu Y, Estrada-Mendez MR, Bardales G, Richardson RE. Performance Evaluation of Gravity-Fed Water Treatment Systems in Rural Honduras: Verifying Robust Reduction of Turbidity and Escherichia coli during Wet and Dry Weather. Am J Trop Med Hyg 2018; 99:881-888. [PMID: 30084345 PMCID: PMC6159558 DOI: 10.4269/ajtmh.17-0577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
This is the first study to document the reduction of turbidity and Escherichia coli throughout the processes of full-scale gravity-fed drinking water plants (GFWTPs) and their downstream distribution systems in rural Honduras. The GFWTPs, which in these cases were designed by AguaClara, use standard treatment processes: coagulation, sedimentation, filtration, and chlorination. During the dry season, we measured E. coli, turbidity, and chlorine residual at five GFWTPs with < 1,000 connections and at three alternative piped-water systems in neighboring communities. Samples were evaluated from the raw water, settled water, filtered water, post-chlorination in the distribution tank, and at a distant-piped household connection. During the dry season, the treated water and household connections serviced by the GFWTPs met World Health Organization (WHO) recommendations for E. coli (< 1 most probable number [MPN]/100 mL). Alternative plants with the same water sources had comparable or higher E. coli and turbidity measurements posttreatment. We examined the performance robustness of two GFWTPs during the transition into the rainy season. The turbidity of the filtered water met WHO recommendations (< 1 nephelometric turbidity units). Escherichia coli was not detected in treated water, indicating that the two GFWTPs can consistently remove particulates and E. coli from source waters containing varying levels of turbidity. During two sampling events during the rainy season, E. coli was detected at the household connection of a GFWTP system with intermittent service and a substandard chlorine residual (geometric mean = 1.0 MPN/100 mL). Strategies to avoid contamination or inactivate E. coli in the distribution system are needed to ensure safe drinking water at the points of delivery, especially for systems with intermittent service.
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Affiliation(s)
- Yolanda M Brooks
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York
| | - Erika A Tenorio-Moncada
- Department of Environment and Development, Panamerican Agriculture University, Zamorano, Yeguare Valley, Municipality of San Antonio de Oriente, Francisco Morazán, Honduras
| | - Nisarg Gohil
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York
| | - Yuqi Yu
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York
| | - Mynor R Estrada-Mendez
- Department of Environment and Development, Panamerican Agriculture University, Zamorano, Yeguare Valley, Municipality of San Antonio de Oriente, Francisco Morazán, Honduras
| | - Geovany Bardales
- Department of Environment and Development, Panamerican Agriculture University, Zamorano, Yeguare Valley, Municipality of San Antonio de Oriente, Francisco Morazán, Honduras
| | - Ruth E Richardson
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York
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17
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Taylor DDJ, Slocum AH, Whittle AJ. Analytical scaling relations to evaluate leakage and intrusion in intermittent water supply systems. PLoS One 2018; 13:e0196887. [PMID: 29775462 PMCID: PMC5959068 DOI: 10.1371/journal.pone.0196887] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/21/2018] [Indexed: 11/18/2022] Open
Abstract
Intermittent water supplies (IWS) deliver piped water to one billion people; this water is often microbially contaminated. Contaminants that accumulate while IWS are depressurized are flushed into customers' homes when these systems become pressurized. In addition, during the steady-state phase of IWS, contaminants from higher-pressure sources (e.g., sewers) may continue to intrude where pipe pressure is low. To guide the operation and improvement of IWS, this paper proposes an analytic model relating supply pressure, supply duration, leakage, and the volume of intruded, potentially-contaminated, fluids present during flushing and steady-state. The proposed model suggests that increasing the supply duration may improve water quality during the flushing phase, but decrease the subsequent steady-state water quality. As such, regulators and academics should take more care in reporting if water quality samples are taken during flushing or steady-state operational conditions. Pipe leakage increases with increased supply pressure and/or duration. We propose using an equivalent orifice area (EOA) to quantify pipe quality. This provides a more stable metric for regulators and utilities tracking pipe repairs. Finally, we show that the volume of intruded fluid decreases in proportion to reductions in EOA. The proposed relationships are applied to self-reported performance indicators for IWS serving 108 million people described in the IBNET database and in the Benchmarking and Data Book of Water Utilities in India. This application shows that current high-pressure, continuous water supply targets will require extensive EOA reductions. For example, in order to achieve national targets, utilities in India will need to reduce their EOA by a median of at least 90%.
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Affiliation(s)
- David D. J. Taylor
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- * E-mail:
| | - Alexander H. Slocum
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Andrew J. Whittle
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
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Olalekan RM, Omidiji AO, Nimisngha D, Odipe OE, Olalekan AS. Health Risk Assessment on Heavy Metals Ingestion through Groundwater Drinking Pathway for Residents in an Oil and Gas Producing Area of Rivers State, Nigeria. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/ojogas.2018.33017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Adane M, Mengistie B, Medhin G, Kloos H, Mulat W. Piped water supply interruptions and acute diarrhea among under-five children in Addis Ababa slums, Ethiopia: A matched case-control study. PLoS One 2017; 12:e0181516. [PMID: 28723927 PMCID: PMC5517045 DOI: 10.1371/journal.pone.0181516] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/03/2017] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The problem of intermittent piped water supplies that exists in low- and middle-income countries is particularly severe in the slums of sub-Saharan Africa. However, little is known about whether there is deterioration of the microbiological quality of the intermittent piped water supply at a household level and whether it is a factor in reducing or increasing the occurrence of acute diarrhea among under-five children in slums of Addis Ababa. This study aimed to determine the association of intermittent piped water supplies and point-of-use (POU) contamination of household stored water by Escherichia coli (E. coli) with acute diarrhea among under-five children in slums of Addis Ababa. METHODS A community-based matched case-control study was conducted from November to December, 2014. Cases were defined as under-five children with acute diarrhea during the two weeks before the survey. Controls were matched by age and neighborhood with cases by individual matching. Data were collected using a pre-tested structured questionnaire and E. coli analysis of water from piped water supplies and household stored water. A five-tube method of Most Probable Number (MPN)/100 ml standard procedure was used for E. coli analysis. Multivariable conditional logistic regression with 95% confidence interval (CI) was used for data analysis by controlling potential confounding effects of selected socio-demographic characteristics. MAIN FINDINGS During the two weeks before the survey, 87.9% of case households and 51.0% of control households had an intermittent piped water supply for an average of 4.3 days and 3.9 days, respectively. POU contamination of household stored water by E. coli was found in 83.3% of the case households, and 52.1% of the control households. In a fully adjusted model, a periodically intermittent piped water supply (adjusted matched odds ratio (adjusted mOR) = 4.8; 95% CI: 1.3-17.8), POU water contamination in household stored water by E. coli (adjusted mOR = 3.3; 95% CI: 1.1-10.1), water retrieved from water storage containers using handle-less vessels (adjusted mOR = 16.3; 95% CI: 4.4-60.1), and water retrieved by interchangeably using vessels both with and without handle (adjusted mOR = 5.4; 95% CI: 1.1-29.1) were independently associated with acute diarrhea. CONCLUSION We conclude that provision of continuously available piped water supplies and education of caregivers about proper water retrieval methods of household stored water can effectively reduce POU contamination of water at the household level and thereby reduce acute diarrhea among under-five children in slums of Addis Ababa. Promotion of household water treatment is also highly encouraged until the City's water authority is able to deliver continuously available piped water supplies.
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Affiliation(s)
- Metadel Adane
- Ethiopian Institute of Water Resources (EIWR), Addis Ababa University, Addis Ababa, Ethiopia
| | - Bezatu Mengistie
- College of Health and Medical Sciences, Haramaya University, Haramaya, Ethiopia
| | - Girmay Medhin
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Helmut Kloos
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, United States of America
| | - Worku Mulat
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT, United States of America
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