Factors Affecting Water Quality in a Water Supply Network

Jachimowski, Artur

doi:10.12911/22998993/74288

Cited by 21 publications

(8 citation statements)

References 3 publications

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“…For instance, changes in color of water in distribution networks could occur due to the release of iron in iron-based pipes (Vreeburg & Boxall 2007), implying that the type of pipe material in the network could influence water discoloration and associated chemical parameters. Moreover, studies have shown that changes in the concentrations of iron in water could induce changes in pH, alkalinity, and electrical conductivity (Bergel et al 2013;Jachimowski 2017). However, the results of the random forest models suggest that pipe material has the least impact on the physical-chemical parameters of water quality included in this study.…”

Section: Conditional Probabilities Of Posterior Predictionsmentioning

confidence: 71%

Modelling the impact of water temperature, pipe, and hydraulic conditions on water quality in water distribution networks

Hadi

Tornyeviadzi

Seidu

2021

Water Practice and Technology

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Identifying and controlling the drivers of change in the quality of water within distribution systems requires a comprehensive understanding of the individual and interactive effects of relevant factors. This article examines the impact of water temperature, pipe characteristics, and hydraulic conditions on the microbiological, physical, and chemical parameters of water quality in the distribution network using Bayesian Dirichlet process mixture of linear models and random forest method. The study was based on a database of the distribution network for the city of Ålesund in Norway and records of water quality data measured at seven different locations in the network from 2013 to 2019. In both modelling approaches applied, temperature was identified as the main factor that controls the microbiological stability of water in the network. From the minimum to the maximum values of temperature in the pipes (3.35 °C–11.14 °C respectively), the probabilities of occurrence of bacteria in water increased from 0.36 to 0.95. Temperature was also shown to be an important factor that affects the chemical parameters of water quality (pH, alkalinity and electrical conductivity). Among the input parameters included in this study, concentration of residual chlorine was shown to have the strongest growth-inhibiting effect on Total Bacteria in the pipes. The results further showed that changes in the hydraulic conditions in the pipes (residence time and flow) were among the most important determinants of the physical, chemical and microbiological quality of water in the distribution network. The random forest models assigned minimal importance to the pipe characteristics and conditions on changes in the water quality parameters. However, the Bayesian models revealed that these parameters have significant impact on the quality of water in the pipes.

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Section: Conditional Probabilities Of Posterior Predictionsmentioning

confidence: 71%

Modelling the impact of water temperature, pipe, and hydraulic conditions on water quality in water distribution networks

Hadi

Tornyeviadzi

Seidu

2021

Water Practice and Technology

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“…Drinking water supply systems are commonly affected by the raw water quality and the capacity of the treatment process to remove pollutants. The biological and physicochemical stability of the water in the network is also a quality issue, as secondary contamination of the water can occur in the supply networks [41]. Among these factors, the effectiveness of the treatment process is certainly the most important and must be carefully adapted to the quality of the incoming raw water.…”

Section: Discussionmentioning

confidence: 99%

The impact of rainfall on drinking water quality in Antananarivo, Madagascar

Bastaraud

Perthame

Rakotondramanga

et al. 2019

Preprint

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21Low-income cities that are subject to high population pressure and vulnerable to 22 climate events often have a low capacity to continuously deliver safe drinking water. Here 23 we report the findings of a 32-year investigation of the temporal dynamics of indicators of 24 drinking water quality in the city of Antananarivo, where we assess the long-term evolution 25 of supplied water quality and characterize the interactions between climate conditions and 26 the full-scale supply system. A total of 25,467 water samples were collected every week 27 at different points in the supplied drinking water system. Samples were analyzed for total 28 coliforms (TC), Escherichia coli (EC), intestinal Enterococci (IE), and spores of Clostridia 29(SSRC). Nine-hundred-eighty-one samples that were identified as positive for one or more 30 indicators were unevenly distributed across the series. The breakpoint method identified 31 four periods when the time series displayed changes in the level and profile of 32 contamination (i) and the monthly pattern of contamination (ii), with more direct effects of 33 rainfall on the quality of supplied drinking water. The modeling showed significantly 34 different lags among indicators of bacteria occurrence after cumulative rainfall, which 35 range from 4 to 8 weeks. Among the effects of low-income urbanization, a rapid 36 demographic transition and urban watershed degradation are progressively affecting the 37 quality of supplied water and resulting in the more direct effects of rainfall events. of 3438 Introduction 39A poor capacity to provide safe drinking water, regardless of weather conditions, is of 40 growing concern in low-income areas vulnerable to climate change [1,2]. Indeed, under 41 global forecasts, some parts of the globe will experience increased frequency and intensity 42 of rainfall [3] with increasing difficulties to limit storm impacts, such as flooding or increased 43 run-off [4,5]. These events are associated with elevated turbidity [6-8] and dissolved 44 organic matter in water sources [9], which can overwhelm treatment plans [10]. Indeed, 45 extreme rainfall regimes are likely to be associated with drinking water contaminations 46 [6,10], and this is predicted to be worsened by climate change [11]. Contaminated water is 47 the main factor of diarrhea in children, and it is evident that an integrated approach to 48 improving water supply will have an impact on the health of the population [12]. 49However, the relationship between rainfall patterns and water microbial quality is 50 complex, involving an interplay between the type of water supply, the type of water source, 51 and the treatment technology applied to water [13]. Also, susceptibility to climate change 52 is reinforced by rapid and unplanned urbanization, poor sanitation, erosion, and low level 53 of maintenance of the supply network [14]. Thus, the nature and the depth of the link 54 between rainfall and water quality is not expected to be stationary. Rather, these should 55 vary with the infrastructure a...

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“…Such seasonal variations in drinking water system performance were potentially due to rapid changes in raw water quality as a result of precipitation (e.g. increased stormwater flows and discharges, soil erosion, sporadic high turbidity) and an increased microbial load entering drinking water distribution [41] (e.g. overloading of the treatment process, adversely affecting disinfection efficiency) [17,42,43].…”

Section: Drinking Water Quality Issuesmentioning

confidence: 99%

The impact of rainfall on drinking water quality in Antananarivo, Madagascar

et al. 2020

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Low-income cities that are subject to high population pressure and vulnerable to climate events often have a low capacity to continuously deliver safe drinking water. Here we reported the results of a 32-year survey on the temporal dynamics of drinking water quality indicators in the city of Antananarivo. We analyzed the long-term evolution of the quality of the water supplied and characterized the interactions between climatic conditions and the full-scale water supply system. A total of 25,467 water samples were collected every week at different points in the supplied drinking water system. Samples were analyzed for total coliforms (TC), Escherichia coli (EC), intestinal Enterococci (IE), and Spores of Sulphite-Reducing Clostridia (SSRC). Nine-hundred-eighty-one samples that were identified as positive for one or more indicators were unevenly distributed over time. The breakpoint method identified four periods when the time series displayed changes in the level and profile of contamination (i) and the monthly pattern of contamination (ii), with more direct effects of rainfall on the quality of supplied drinking water. The modeling showed significantly different lags among indicators of bacteria occurrence after cumulative rainfall, which range from 4 to 8 weeks. Among the effects of low-income urbanization, a rapid demographic transition and the degradation of urban watersheds have gradually affected the quality of the water supplied and resulted in the more direct effects of rainfall events. We focused on the need to adopt an alternative perspective of drinking water and urban watersheds management.

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Factors Affecting Water Quality in a Water Supply Network

Cited by 21 publications

References 3 publications

Modelling the impact of water temperature, pipe, and hydraulic conditions on water quality in water distribution networks

Modelling the impact of water temperature, pipe, and hydraulic conditions on water quality in water distribution networks

The impact of rainfall on drinking water quality in Antananarivo, Madagascar

The impact of rainfall on drinking water quality in Antananarivo, Madagascar

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