scholarly journals DRINKING WATER QUALITY IN DISTRIBUTION SYSTEMS OF SURFACE AND GROUND WATERWORKS IN FINLAND

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Jenni Meirami Ikonena ◽  
Anna-Maria Hokajärvi ◽  
Jatta Heikkinen ◽  
Tarja Pitkänen ◽  
Robert Ciszek ◽  
...  

Physico-chemical and microbiological water quality in the drinking water distribution systems (DWDSs) of five waterworks in Finland with different raw water sources and treatment processes was explored. Water quality was monitored during four seasons with on-line equipment and bulk water samples were analysed in laboratory. Seasonal changes in the water quality were more evident in DWDSs of surface waterworks compared to the ground waterworks and artificially recharging ground waterworks (AGR). Between seasons, temperature changed significantly in every sys-tem but pH and EC changed only in one AGR system. Seasonal change was seen also in the absorbance values of all sys-tems. The concentration of microbially available phosphorus (MAP, μg PO₄-P/l) was the highest in drinking water origi-nating from the waterworks supplying groundwater. Total assimilable organic carbon (AOC, μg AOC-C/l) concentrations were significantly different between the DWDSs other than between the two AGR systems. This study reports differences in the water quality between surface and ground waterworks using a wide set of parameters commonly used for monitor-ing. The results confirm that every distribution system is unique, and the water quality is affected by environmental fac-tors, raw water source, treatment methods and disinfection.

2012 ◽  
Vol 12 (5) ◽  
pp. 580-587 ◽  
Author(s):  
Stephen Mounce ◽  
John Machell ◽  
Joby Boxall

Safe, clean drinking water is a foundation of society and water quality monitoring can contribute to ensuring this. A case study application of the CANARY software to historic data from a UK drinking water distribution system is described. Sensitivity studies explored appropriate choice of algorithmic parameter settings for a baseline site, performance was evaluated with artificial events and the system then transferred to all sites. Results are presented for analysis of nine water quality sensors measuring six parameters and deployed in three connected district meter areas (DMAs), fed from a single water source (service reservoir), for a 1 year period and evaluated using comprehensive water utility records with 86% of event clusters successfully correlated to causes (spatially limited to DMA level). False negatives, defined by temporal clusters of water quality complaints in the pilot area not corresponding to detections, were only approximately 25%. It was demonstrated that the software could be configured and applied retrospectively (with potential for future near real time application) to detect various water quality event types (with a wider remit than contamination alone) for further interpretation.


Author(s):  
Valeria Mirela Brezoczki ◽  
◽  
Gabriela Maria Filip ◽  

This paper presents the analysis of the quality indicator of a subterranean raw water source, captured in Crăciunesti, Sighetu Marmatiei, followed by the description of the technological flow of capturing and chlorinating water with the aim of making it drinkable, and the analysis of the obtained values of the physical, chemical and bacteriological indicators. The period within which water quality was monitored for this paper covers four months (December 2016, March, April and May 2017). Within this period the analyses regarding water quality control were carried out by the laboratory of the Water Treatment Baia Mare. The analysis of the obtained results highlighted a series of problems regarding the existence of certain indicators/parameters with values above the legally admissible threshold with regard to water quality. The manganese found in raw water exceeds the admissible threshold by 160%, in December 2016, and by 120% in March 2017, but it is within limits during the months of April and May. The occurrence of colonies developed at 37 °C and 22°C in the raw water requires chemical treatment of the raw water aimed at disinfecting it. The parameters of drinking water correspond to the values admissible through the laws in force, the water being distributed to the consumers through the Drinking water distribution system in Sighetu Marmatiei.


1997 ◽  
Vol 35 (11-12) ◽  
pp. 283-287 ◽  
Author(s):  
Ph. Piriou ◽  
S. Dukan ◽  
Y. Levi ◽  
P. A. Jarrige

Of the many causes of drinking water quality deterioration in distribution systems, biological phenomena are undoubtedly the subject of the most study. They are also the most closely monitored because of short-term public health risks. A determinist model was developed to predict bacterial growth in the network and to locate the zones where the risks of biological proliferation are the highest. The model takes into account the growth of suspended and fixed bacteria, the consumption of available nutrients in the bulk water and in the biofilm layer, the influence of chlorine residual on the mortality of suspended and fixed biomass, the deposition of suspended bacteria and the detachment of biofilm cells, the influence of temperature on bacterial activity and chlorine decay. The model is constructed using hydraulic results previously generated by PICCOLO, the SAFEGE hydraulic computer model and a numerical scheme to predict bacterial count at each node and on each link of a network. The model provides an effective and each way to visualise on a computer screen variations in water quality in the network. The first model calibration was done using data obtained from a pipe loop system pilot. A validation of the model has been carried out by means of measurement campaigns on various real networks. This predictive model of bacterial growth in distribution systems is a unique approach for the study, diagnosis and management of distributed water quality. This tool is helpful for proposing strategies for the management of distribution systems and treatment plants and to define conditions and locations of high bacterial counts in relation to hydraulic conditions.


2021 ◽  
Vol 12 ◽  
Author(s):  
Frances C. Pick ◽  
Katherine E. Fish ◽  
Stewart Husband ◽  
Joby B. Boxall

Biofilms are endemic in drinking water distribution systems (DWDS), forming on all water and infrastructure interfaces. They can pose risks to water quality and hence consumers. Our understanding of these biofilms is limited, in a large part due to difficulties in sampling them without unacceptable disruption. A novel, non-destructive and non-disruptive biofilm monitoring device (BMD), which includes use of flow cytometry analysis, was developed to assess biofouling rates. Laboratory based experiments established optimal configurations and verified reliable cell enumeration. Deployment at three operational field sites validated assessment of different biofouling rates. These differences in fouling rates were not obvious from bulk water sampling and analysis, but did have a strong correlation with long-term performance data of the associated networks. The device offers the potential to assess DWDS performance in a few months, compared to the number of years required to infer findings from historical customer contact data. Such information is vital to improve the management of our vast, complex and uncertain drinking water supply systems; for example rapidly quantifying the benefits of improvements in water treatment works or changes to maintenance of the network.


2001 ◽  
Vol 1 (4) ◽  
pp. 237-245 ◽  
Author(s):  
V. Gauthier ◽  
B. Barbeau ◽  
R. Millette ◽  
J.-C. Block ◽  
M. Prévost

The concentrations of suspended particles were measured in the drinking water of two distribution systems, and the nature of these particles documented. The concentrations of particulate matter were invariably found to be small (maximum 350 μg/L). They are globally in the very low range in comparison with dissolved matter concentrations, which are measured in several hundreds of mg/L. Except during special water quality events, such as turnover of the raw water resource, results show that organic matter represents the most important fraction of suspended solids (from 40 to 76%) in treated and distributed water. Examination of the nature of the particles made it possible to develop several hypotheses about the type of particles penetrating Montreal's distribution system during the turnover period (algae skeleton, clays). These particles were found to have been transported throughout the distribution systems quite easily, and this could result in the accumulation of deposits if their surface charge were ever even slightly destabilised, or if the particles were to penetrate the laminar flow areas that are fairly typical of remote locations in distribution systems.


2006 ◽  
Vol 6 (2) ◽  
pp. 147-151 ◽  
Author(s):  
X.-J. Zhang ◽  
W. Lu

Biofilm growth in drinking water distribution systems was studied in an annular reactor system which was designed to model the hydraulic conditions in water mains. Experiments were performed with chlorine-free water as well as with different disinfectant (chlorine or chloramine) residuals and different AOC concentrations added to the reactor influent to examine the effect of disinfectant residuals and AOC concentrations on biofilm accumulation and planktonic cell numbers. The dynamic parameters of bacteria growth were calculated in water with different disinfectant (chlorine or chloramine) and the results indicated that monochloramine may be more effective than free chlorine for control of biofilm accumulation.


2018 ◽  
Vol 4 (12) ◽  
pp. 2080-2091 ◽  
Author(s):  
Isabel Douterelo ◽  
Carolina Calero-Preciado ◽  
Victor Soria-Carrasco ◽  
Joby B. Boxall

This research highlights the potential of whole metagenome sequencing to help protect drinking water quality and safety.


2003 ◽  
Vol 3 (1-2) ◽  
pp. 239-246 ◽  
Author(s):  
G. Kastl ◽  
I. Fisher ◽  
V. Jegatheesan ◽  
J. Chandy ◽  
K. Clarkson

Nearly all drinking water distribution systems experience a “natural” reduction of disinfection residuals. The most frequently used disinfectant is chlorine, which can decay due to reactions with organic and inorganic compounds in the water and by liquid/solids reaction with the biofilm, pipe walls and sediments. Usually levels of 0.2-0.5 mg/L of free chlorine are required at the point of consumption to maintain bacteriological safety. Higher concentrations are not desirable as they present the problems of taste and odour and increase formation of disinfection by-products. It is usually a considerable concern for the operators of drinking water distribution systems to manage chlorine residuals at the “optimum level”, considering all these issues. This paper describes how the chlorine profile in a drinking water distribution system can be modelled and optimised on the basis of readily and inexpensively available laboratory data. Methods are presented for deriving the laboratory data, fitting a chlorine decay model of bulk water to the data and applying the model, in conjunction with a simplified hydraulic model, to obtain the chlorine profile in a distribution system at steady flow conditions. Two case studies are used to demonstrate the utility of the technique. Melbourne’s Greenvale-Sydenham distribution system is unfiltered and uses chlorination as its only treatment. The chlorine model developed from laboratory data was applied to the whole system and the chlorine profile was shown to be accurately simulated. Biofilm was not found to critically affect chlorine decay. In the other case study, Sydney Water’s Nepean system was modelled from limited hydraulic data. Chlorine decay and trihalomethane (THM) formation in raw and treated water were measured in a laboratory, and a chlorine decay and THM model was derived on the basis of these data. Simulated chlorine and THM profiles agree well with the measured values available. Various applications of this modelling approach are also briefly discussed.


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