scholarly journals Characterizing the concentration of Cryptosporidium in Australian surface waters for setting health-based targets for drinking water treatment

2015 ◽  
Vol 13 (3) ◽  
pp. 879-896 ◽  
Author(s):  
S. Petterson ◽  
D. Roser ◽  
D. Deere
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Physiological State ◽  
Drinking Water Treatment ◽  
World Health ◽  
Quantitative Microbial Risk Assessment ◽  
Surface Source ◽  
Microbial Risk Assessment ◽  
Treatment Targets ◽  
Climatic Regions

It is proposed that the next revision of the Australian Drinking Water Guidelines will include ‘health-based targets’, where the required level of potable water treatment quantitatively relates to the magnitude of source water pathogen concentrations. To quantify likely Cryptosporidium concentrations in southern Australian surface source waters, the databases for 25 metropolitan water supplies with good historical records, representing a range of catchment sizes, land use and climatic regions were mined. The distributions and uncertainty intervals for Cryptosporidium concentrations were characterized for each site. Then, treatment targets were quantified applying the framework recommended in the World Health Organization Guidelines for Drinking-Water Quality 2011. Based on total oocyst concentrations, and not factoring in genotype or physiological state information as it relates to infectivity for humans, the best estimates of the required level of treatment, expressed as log10 reduction values, ranged among the study sites from 1.4 to 6.1 log10. Challenges associated with relying on historical monitoring data for defining drinking water treatment requirements were identified. In addition, the importance of quantitative microbial risk assessment input assumptions on the quantified treatment targets was investigated, highlighting the need for selection of locally appropriate values.

scholarly journals The Dutch secret: safe drinking water without chlorine in the Netherlands

2008 ◽  
Vol 1 (2) ◽  
pp. 173-212 ◽  
Author(s):  
P. W. M. H. Smeets ◽  
G. J. Medema ◽  
J. C. van Dijk
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
The Netherlands ◽  
Distribution System ◽  
Drinking Water Treatment ◽  
Quantitative Microbial Risk Assessment ◽  
Safe Drinking Water ◽  
Microbial Risk Assessment ◽  
Production And Distribution ◽  
Water Companies

Abstract. The Netherlands is one of the few countries where chlorine is not used at all, neither for primary disinfection nor to maintain a residual disinfectant in the distribution network. The Dutch approach that allows production and distribution of drinking water without the use of chlorine while not compromising microbial safety at the tap, can be summarized as follows: Use the best source available, in order of preference: – microbiologically safe groundwater, – surface water with soil passage such as artificial recharge or bank filtration, – direct treatment of surface water in a multiple barrier treatment; Use a preferred physical process treatment such as sedimentation, filtration and UV-disinfection. If absolutely necessary, also oxidation by means of ozone or peroxide can be used, but chlorine is avoided; Prevent ingress of contamination during distribution; Prevent microbial growth in the distribution system by production and distribution of biologically stable (biostable) water and the use of biostable materials; Monitor for timely detection of any failure of the system to prevent significant health consequences. New developments in safe drinking water in the Netherlands include the adaptation of the Dutch drinking water decree, implementation of quantitative microbial risk assessment (QMRA) by water companies and research into source water quality, drinking water treatment efficacy, safe distribution and biostability of drinking water during distribution and \\textit{Legionella}. This paper summarizes how the Dutch water companies warrant the safety of the drinking water without chlorine.

Occurrence of microcystins in raw water sources and treated drinking water of Finnish waterworks

2001 ◽  
Vol 43 (12) ◽  
pp. 225-228 ◽  
Author(s):  
K. Lahti ◽  
J. Rapala ◽  
A-L. Kivimäki ◽  
J. Kukkonen ◽  
M. Niemelä ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Water Sources ◽  
World Health ◽  
Bank Filtration ◽  
Raw Water ◽  
Guide Value ◽  
The World ◽  
Treated Drinking Water

Problems caused by cyanobacteria are common around the world and also in raw water sources of drinking water treatment plants. Strains belonging to genera Microcystis, Anabaena and Planktothrix produce potent hepatotoxins, the microcystins. Laboratory and pilot scale studies have shown that microcystins dissolved in water may pass the conventional surface water treatment processes. In 1998 the World Health Organization proposed a guide value of 1 μg/L for microcystin-LR (MC-LR) in drinking water. The purpose of this research was to study the occurrence of microcystins in raw water sources of surface waterworks and in bank filtration plants and to evaluate the removal of microcystins in operating waterworks. Four bank filtration plants and nine surface waterworks using different processes for water treatment were monitored. Phytoplankton was identified and quantified, and microcystins analysed with sensitive immunoassay. Microcystin occurrence in selected water samples was verified with HPLC and a protein phosphatase inhibition method. Microcystins were detected sporadically in raw water sources of most of the waterworks. In two raw water supplies toxins were detected for several months. The highest microcystin concentrations in incoming raw water were approximately 10 μg/L MC-LR equivalents. In treated drinking water microcystins were detected occasionally but the concentrations were always below the guide value proposed by WHO.

Identification, assessment, and control of hazards in water supply: experiences from Water Safety Plan implementations in Germany

2010 ◽  
Vol 61 (5) ◽  
pp. 1307-1315 ◽  
Author(s):  
H.-J. Mälzer ◽  
N. Staben ◽  
A. Hein ◽  
W. Merkel
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Water Supply ◽  
Drinking Water Treatment ◽  
Control Measures ◽  
World Health ◽  
Water Safety ◽  
Water Safety Plan ◽  
Health Organization ◽  
And Control

According to the recommendations of the World Health Organization (WHO) for Water Safety Plans (WSP), a Technical Risk Management was developed, which considers standard demands in drinking water treatment in Germany. It was already implemented at several drinking water treatment plants of different size and treatment processes in Germany. Hazards affecting water quality, continuity, and the reliability of supply from catchment to treatment and distribution could be identified by a systematic approach, and suitable control measures were defined. Experiences are presented by detailed examples covering methods, practical consequences, and further outcomes. The method and the benefits for the water suppliers are discussed and an outlook on the future role of WSPs in German water supply is given.

scholarly journals Insights into Solar Disinfection Enhancements for Drinking Water Treatment Applications

2021 ◽  
Vol 13 (19) ◽  
pp. 10570
Author(s):  
Abdassalam A. Azamzam ◽  
Mohd Rafatullah ◽  
Esam Bashir Yahya ◽  
Mardiana Idayu Ahmad ◽  
Japareng Lalung ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Water Disinfection ◽  
World Health ◽  
Solar Disinfection ◽  
Physical Chemical ◽  
Main Challenge ◽  
Pre Treatment ◽  
Health Organization

Poor access to drinking water, sanitation, and hygiene has always been a major concern and a main challenge facing humanity even in the current century. A third of the global population lacks access to microbiologically safe drinking water, especially in rural and poor areas that lack proper treatment facilities. Solar water disinfection (SODIS) is widely proven by the World Health Organization as an accepted method for inactivating waterborne pathogens. A significant number of studies have recently been conducted regarding its effectiveness and how to overcome its limitations, by using water pretreatment steps either by physical, chemical, and biological factors or the integration of photocatalysis in SODIS processes. This review covers the role of solar disinfection in water treatment applications, going through different water treatment approaches including physical, chemical, and biological, and discusses the inactivation mechanisms of water pathogens including bacteria, viruses, and even protozoa and fungi. The review also addresses the latest advances in different pre-treatment modifications to enhance the treatment performance of the SODIS process in addition to the main limitations and challenges.

scholarly journals A web-based early-warning service to monitor drinking-water treatment plant operations

2010 ◽  
pp. 69-73
Author(s):  
Franclin S. Foping
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Distribution Systems ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
World Health ◽  
Raw Water ◽  
Supply And Distribution ◽  
The World

Drinking contaminated water can be harmful to our health. According to the World Health Organization, about 1.8 million people die every year across the world from water-borne diseases mainly caused by polluted drinking water. Furthermore, the cryptosporidium outbreak that happened in Galway in 2007 indicates the urgency to provide appropriate solutions in order to counteract this ominous situation in the country. Water treatment plants (WTP) are basic components of modern water supply and distribution systems. These are engineering systems that purify raw water to specific safety levels. The raw water passes through a series of treatment phases wherein it is processed and purified according to existing safety protocols regulating drinking water. After undergoing a purification step, the drinking water is distributed to the consumers through a network of pipes, pumps and reservoirs. The research presented in this report is focused on the safety of these critical infrastructures. In particular, the ...

Scenario-based quantitative microbial risk assessment to evaluate the robustness of a drinking water treatment plant

2016 ◽  
Vol 51 (2) ◽  
pp. 81-96 ◽  
Author(s):  
Mohamed A. Hamouda ◽  
William B. Anderson ◽  
Michele I. Van Dyke ◽  
Ian P. Douglas ◽  
Stéphanie D. McFadyen ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Operating Conditions ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Treatment Processes

While traditional application of quantitative microbial risk assessment (QMRA) models usually stops at analyzing the microbial risk under typical operating conditions, this paper proposes the use of scenario-based risk assessment to predict the impact of potential challenges on the expected risk. This study used a QMRA model developed by Health Canada to compare 14 scenarios created to assess the increase in risk due to potential treatment failures and unexpected variations in water quality and operating parameters of a water treatment plant. Under regular operating conditions, the annual risk of illness was found to be substantially lower than the acceptable limit. Scenario-based QMRA was shown to be useful in demonstrating which hypothetical treatment failures would be the most critical, resulting in an increased risk of illness. The analysis demonstrated that scenarios incorporating considerable failure in treatment processes resulted in risk levels surpassing the acceptable limit. This reiterates the importance of robust treatment processes and the multi-barrier approach voiced in drinking water safety studies. Knowing the probability of failure, and the risk involved, allows designers and operators to make effective plans for response to treatment failures and/or recovery actions involving potential exposures. This ensures the appropriate allocation of financial and human resources.

scholarly journals The Dutch secret: how to provide safe drinking water without chlorine in the Netherlands

2009 ◽  
Vol 2 (1) ◽  
pp. 1-14 ◽  
Author(s):  
P. W. M. H. Smeets ◽  
G. J. Medema ◽  
J. C. van Dijk
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
The Netherlands ◽  
Distribution System ◽  
Drinking Water Treatment ◽  
Quantitative Microbial Risk Assessment ◽  
Safe Drinking Water ◽  
Microbial Risk Assessment ◽  
Production And Distribution ◽  
Water Companies

Abstract. The Netherlands is one of the few countries where chlorine is not used at all, neither for primary disinfection nor to maintain a residual disinfectant in the distribution network. The Dutch approach that allows production and distribution of drinking water without the use of chlorine while not compromising microbial safety at the tap, can be summarized as follows: 1. Use the best source available, in order of preference:     – microbiologically safe groundwater,     – surface water with soil passage such as artificial recharge or bank filtration,     – direct treatment of surface water in a multiple barrier treatment; 2. Use a preferred physical process treatment such as sedimentation, filtration and UV-disinfection. If absolutely necessary, also oxidation by means of ozone or peroxide can be used, but chlorine is avoided; 3. Prevent ingress of contamination during distribution; 4. Prevent microbial growth in the distribution system by production and distribution of biologically stable (biostable) water and the use of biostable materials; 5. Monitor for timely detection of any failure of the system to prevent significant health consequences. New developments in safe drinking water in the Netherlands include the adaptation of the Dutch drinking water decree, implementation of quantitative microbial risk assessment (QMRA) by water companies and research into source water quality, drinking water treatment efficacy, safe distribution and biostability of drinking water during distribution and Legionella. This paper summarizes how the Dutch water companies warrant the safety of the drinking water without chlorine.

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