scholarly journals Microbial Community Structure and Diversity in Drinking Water Supply, Distribution Systems as well as Household Point of use Site in Addis Ababa City, Ethiopia

Author(s):  
Bayable Atanfu ◽  
Adey Desta ◽  
Fassil Assefa

Abstract Understanding ecology of microbiomes in drinking water distribution systems is the most important notion in delivering safe drinking water. Despite cultivation-based methods routinely employed in monitoring drinking water quality, cultivation of specific indicator organisms alone is not always guarantee for assuring safe drinking water delivery. The presence of complex microbiomes in drinking water distribution systems affects treatment effectiveness leading to poor quality water which as a result affects health of human and animals. Drinking water treatment and distribution systems harbor various microbiota despite efforts made in improving water infrastructures and several waterborne diseases become serious problems in the water industry, specially, in developing Countries. Intermittent water supply, long-time of water storage, low water pressure in distribution systems, storage tankers and pipes as well as contaminated source water are among many of the factors responsible for low drinking water quality which in turn affecting health of people. The aim of this study was to explore microbial diversity and structure in water samples collected from source water, treated water, reservoirs, and several household points of use locations (taps). High throughput Illumina sequencing technology was employed by targeting V4 region of 16S rRNA following Illumina protocol to analyze the community structure of bacteria. The core dominating taxa were Proteobacteria followed by Firmicutes, Bacteroidetes and Actinobacteria. Gamma proteobacteria were dominant among other Proteobacterial classes across all sampling points. Opportunistic bacterial genera such as Pseudomonas, Legionella, Klebsiella, Escherichia, Actinobacteria, as well as eukaryotic microbes like Cryptosporidium, Hartmanella, Acanthamoeba, Aspergillus, and Candida were also the abundant taxa found along the distribution systems. The shift in microbial community structure from source to point of use locations were influenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household. The shift in microbial community structure from source to point of use locations were influenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household. The complex microbiota which was present in different sample sites receiving treated water from the two treatment plants (Legedadi and Gefersa) starting from source water to household point of consumption across the distribution systems in Addis Ababa brings drinking water quality problem which further causes significant health problems to both human and animal health. Treatment ineffectiveness, disinfection inefficiency, poor maintenance actions, leakage of sewage and other domestic wastes are few among many other factors responsible for degraded drinking water quality in this study putting health at high risk which, this, leads to morbidity and mortality. Findings of this research provide important and bassline information to understand the microbial profiles of drinking water along source water and distribution systems.

2021 ◽  
Author(s):  
Bayable Atanfu ◽  
Adey Desta ◽  
Fassil Assefa

Abstract BackgroundUnderstanding ecology of microbiomes in drinking water distribution systems is the most important notion in delivering safe drinking water. Despite cultivation-based methods routinelyemployed in monitoring drinking water quality, cultivation of specific indicator organisms alone is not always guarantee for assuring safe drinking water delivery. The presence of complex microbiomes in drinking water distribution systems affects treatment effectiveness leading to poor quality water which as a result affects health of human and animals. Drinking water treatment and distribution systems harbor various microbiota despite efforts made in improving water infrastructures and several waterborne diseases become serious problems in the water industry, specially, in developing Countries. Intermittent water supply, long-time of water storage, low water pressure in distribution systems, storage tankers and pipes as well as contaminated source water are among many of the factors responsible for low drinking water quality which in turn affecting health of people. The aim of this study was to explore microbial diversity and structure in water samples collected from source water, treated water, reservoirs, and several household points of use locations (taps). High throughput Illumina sequencing technology was employed by targeting V4 region of 16S rRNA following Illumina protocol to analyze the community structure of bacteria. ResultsThe core dominating taxa were Proteobacteria followed by Firmicutes, Bacteroidetes and Actinobacteria. Gamma proteobacteria were dominant among other Proteobacterial classes across all sampling points. Opportunistic bacterial genera such as Pseudomonas, Legionella, Klebsiella, Escherichia, Actinobacteria, as well as eukaryotic microbes like Cryptosporidium, Hartmanella, Acanthamoeba, Aspergillus, and Candida were also the abundant taxa found alongthe distribution systems. The shift in microbial community structure from source to point of uselocations were influenced by factors such as residual free chlorine, intermittent water supply andlong-time storage at the household. The shift in microbial community structure from source to point of use locations were influenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household.ConclusionsThe complex microbiota which was present in different sample sites receiving treated water from the two treatment plants (Legedadi and Gefersa) starting from source water to household point of consumption across the distribution systems in Addis Ababa brings drinking water quality problem which further causes significant health problems to both human and animal health. Treatment ineffectiveness, disinfection inefficiency, poor maintenance actions, leakage of sewage and other domestic wastes are few among many other factors responsible for degraded drinking water quality in this study putting health at high risk which, this, leads to morbidity and mortality. Findings of this research provide important and bassline information to understand the microbial profiles of drinking water along source water and distribution systems.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1361
Author(s):  
Hongxing Li ◽  
Alasdair Cohen ◽  
Zheng Li ◽  
Shibo Lv ◽  
Zuan He ◽  
...  

Intermittent water supply (IWS) is a relatively common phenomenon across the world as well as in rural and peri-urban areas across China, though there has been little IWS-focused research from China published to date. IWS consumers typically adopt a range of strategies to cope with insufficient water supply, poor drinking water quality, and associated inconveniences. In this study, we collected a range of data from small-scale utilities and households in two IWS systems and two continuous water supply (CWS) systems, as well as from comparison groups, in Shandong and Hubei provinces. Data collection included water quality testing, interviews, and surveys on behavioral adaptations, coping strategies, water-related health perceptions, and other metrics of consumer satisfaction. Overall, we found that the IWS coping strategies employed in northern China (Shandong) were associated with generally safe, but inconvenient, water access, whereas adaptation strategies observed in southern China (Hubei) appeared to improve convenience, but not water quality. Compared to the CWS comparison groups, we did not observe significant differences in water- and sanitation-related behaviors in the IWS groups, suggesting interventions to increase adaptive and protective behaviors at the household level might further improve safe water access for households living with IWS. Overall, although the water supply infrastructure in these study areas appeared to be in relatively good condition, in contrast to reported data on IWS systems in other countries, we observed multiple risk factors associated with the water treatment and distribution processes in these IWS systems. Among policy recommendations, our results suggest that the implementation of Water Safety Plans in China would likely improve the management of drinking water treatment and, by extension, safe drinking water supply under conditions of IWS.


Author(s):  
Yu.A. Novikova ◽  
I.O. Myasnikov ◽  
A.A. Kovshov ◽  
N.A. Tikhonova ◽  
N.S. Bashketova

Summary. Introduction: Drinking water is one of the most important environmental factors sustaining life and determining human health. The goal of the Russian Federal Clean Water Project is to improve drinking water quality through upgrading of water treatment and supply systems using advanced technologies, including those developed by the military-industrial complex. The most informative and reliable sources of information for assessing drinking water quality are the results of systematic laboratory testing obtained within the framework of socio-hygienic monitoring (SGM) and production control carried out by water supply organizations. The objective of our study was to formulate approaches to organizing quality monitoring programs for centralized cold water supply systems. Materials and methods: We reviewed programs and results of drinking water quality laboratory tests performed by Rospotrebnadzor bodies and institutions within the framework of SGM in 2017–2018. Results: We established that drinking water quality monitoring in the constituent entities of the Russian Federation differs significantly in the number of monitoring points (566 in the Krasnoyarsk Krai vs 10 in Sevastopol) and measured indicators, especially sanitary and chemical ones (53 inorganic and organic substances in the Kemerovo Region vs one indicator in the Amur Region). Discussion: For a more complete and objective assessment of drinking water quality in centralized cold water supply systems, monitoring points should be organized at all stages of water supply with account for the coverage of the maximum number of people supplied with water from a particular network. Thus, the number of points in the distribution network should depend, inter alia, on the size of population served. In urban settlements with up to 10,000 inhabitants, for example, at least 4 points should be organized while in the cities with more than 3,000,000 inhabitants at least 80 points are necessary. We developed minimum mandatory lists of indicators and approaches to selecting priority indices to be monitored at all stages of drinking water supply.


2005 ◽  
Vol 5 (2) ◽  
pp. 123-134 ◽  
Author(s):  
R. Miller ◽  
B. Whitehill ◽  
D. Deere

This paper comments on the strengths and weaknesses of different methodologies for risk assessment, appropriate for utilisation by Australian Water Utilities in risk assessment for drinking water source protection areas. It is intended that a suggested methodology be recommended as a national approach to catchment risk assessment. Catchment risk management is a process for setting priorities for protecting drinking water quality in source water areas. It is structured through a series of steps for identifying water quality hazards, assessing the threat posed, and prioritizing actions to address the threat. Water management organisations around Australia are at various stages of developing programs for catchment risk management. While much conceptual work has been done on the individual components of catchment risk management, work on these components has not previously been combined to form a management tool for source water protection. A key driver for this project has been the requirements of the National Health and Medical Research Council Framework for the Management of Drinking Water Quality (DWQMF) included in the draft 2002 Australian Drinking Water Guidelines (ADWG). The Framework outlines a quality management system of steps for the Australian water industry to follow with checks and balances to ensure water quality is protected from catchment to tap. Key steps in the Framework that relate to this project are as follows: Element 2 Assessment of the Drinking Water Supply System• Water Supply System analysis• Review of Water Quality Data• Hazard Identification and Risk Assessment Element 3 Preventive Measures for Drinking Water Quality Management• Preventive Measures and Multiple Barriers• Critical Control Points This paper provides an evaluation of the following risk assessment techniques: Hazard Analysis and Critical Control Points (HACCP); World Health Organisation Water Safety Plans; Australian Standard AS 4360; and The Australian Drinking Water Guidelines – Drinking Water Quality Management Framework. These methods were selected for assessment in this report as they provided coverage of the different approaches being used across Australia by water utilities of varying: scale of water management organisation; types of water supply system management; and land use and activity-based risks in the catchment area of the source. Initially, different risk assessment methodologies were identified and reviewed. Then examples of applications of those methods were assessed, based on several key water utilities across Australia and overseas. Strengths and weaknesses of each approach were identified. In general there seems some general grouping of types of approaches into those that: cover the full catchment-to-tap drinking water system; cover just the catchment area of the source and do not recognise downstream barriers or processes; use water quality data or land use risks as a key driving component; and are based primarily on the hazard whilst others are based on a hazardous event. It is considered that an initial process of screening water quality data is very valuable in determining key water quality issues and guiding the risk assessment, and to the overall understanding of the catchment and water source area, allowing consistency with the intentions behind the ADWG DWQM Framework. As such, it is suggested that the recommended national risk assessment approach has two key introductory steps: initial screening of key issues via water quality data, and land use or activity scenario and event-based HACCP-style risk assessment. In addition, the importance of recognising the roles that uncertainty and bias plays in risk assessments was highlighted. As such it was deemed necessary to develop and integrate uncertainty guidelines for information used in the risk assessment process. A hybrid risk assessment methodology was developed, based on the HACCP approach, but with some key additions and modifications to make it applicable to varying catchment risks, water supply operation needs and environmental management processes.


2021 ◽  
Vol 15 (4) ◽  
pp. 168-176
Author(s):  
M. G. Daudova ◽  
R. B. Bagomedova ◽  
K. K. Bekshokov ◽  
M. M. Medzhidova ◽  
S. M. Nakhibashev ◽  
...  

Aim. Study of the influence of drinking water quality on the ecologically-dependent morbidity of the population of the Republic of Dagestan.Material and Methods. Methods of current and retrospective analysis of regional health indicators and methods of mathematical-statistical and medical-geographical analysis were used. Statistical processing of the results was carried out using the STATISTICA and Excel software packages. When carrying out laboratory studies on the quality of drinking water, we used a Lumex atomic absorption spectrometer "MGA-915MD".Results. Numerous hygiene studies indicate the direct impact of unsatisfactory drinking water quality on the health of a population. The relationship between sanitary and chemical indicators and the incidence rate for a number of nosological forms has been proven. It is generally accepted that human health is influenced by lifestyle factors (working, living and relaxation conditions), heredity and the ecological condition of the area of residence, including the quality of drinking water. Although it is not possible to differentiate the share of the negative effect caused by the consumption of poor quality drinking water but the incidence of certain nosological forms (cancer of the esophagus, gastrointestinal tract and kidney diseases) in the those regions of the Republic of Dagestan under consideration correlates with the characteristics of drinking water.Conclusion. The problem of pollution of water supply sources for the population in the dynamics of the long-term remains a priority concern. The quality and safety of drinking water are decreasing, which cannot but have a negative impact on public health. Correlation linkages between indicators of drinking water quality and oncological morbidity of the population were also established in indicators below the maximum permissible concentrations, which corresponds to a typical logistic model of causal relationships and serves as evidence of the high dependence of health disorders on chemical contamination of water supply sources. 


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