Temporal changes in peri-urban drinking water practices and quality

In this study, different optical, physical and chemical measurements were tested for their capacity to detect changes in water quality. The tests included UV-absorbance at 254 nm, absorbance at 420 nm, turbidity, particle counting, temperature, pH, electric conductivity (EC), free chlorine concentration and ATP concentration measurements. Special emphasis was given to investigating the potential for measurement tools to detect changes in bacterial concentrations in drinking water. Bacterial colony counts (CFU) and total bacterial cell counts (TBC) were used as reference methods for assessing the bacterial water quality. The study consists of a series of laboratory scale experiments: monitoring of regrowth of Pseudomonas fluorescens, estimation of the detection limits for optical measurements using Escherichia coli dilutions, verification of the relationships by analysing grab water samples from various distribution systems and utilisation of the measurements in the case of an accidentally contaminated distribution network. We found significant correlations between the tested measurements and the bacterial water quality. As the bacterial contamination of water often co-occurs with the intrusion of matrixes containing mainly non-bacterial components, the tested measurement tools can be considered to have the potential to rapidly detect any major changes in drinking water quality.

Bacterial indicator organisms (e.g., coliforms, E. coli) and some chemical parameters (e.g., turbidity, ammonia) are basic monitoring tools used to measure both changes in drinking-water quality and the presence of hard-to-detect pathogenic bacteria, viruses and protozoa. Microscopically detectable free-living organisms, such as some groups of bacteria, fungi, nematodes, rotifers and protozoa, are usable as additional indicators of fecal or environmental contamination of drinking water as well as any changes in the drinking-water quality. Our aim in this paper is to summarize the results of microscopic examination of 913 drinking-water samples from different water sources in Hungary in 2004 and 2005 and to demonstrate how these results can be used to maintain safe and good-tasting drinking-water quality. A total of 277 drinking-water samples failed Hungarian microscopic water quality standards as a result of helminths (58%), protozoa (41%), iron bacteria (16%), sulfur bacteria (13%), fungi (11%), algae (5%) and multiple biological contaminants (34%). Based on these results, pipe washing or water storage tank cleaning was deemed necessary. In addition, a number of disinfection or filtration failures were found. Two detailed case studies show the usefulness of monitoring microscopic parameters to avoid disease outbreaks. To our knowledge this is the first paper discussing drinking-water microscopy based on Hungarian experience and practice, which could be useful and informative for other countries.

An experimental study on the influence of water stagnation and temperature change on water quality in a full-scale domestic drinking water system

Case study: Fixture water use and drinking water quality in a new residential green building

ABSTRACK Background: Water represents an absolute medium to human life and other living things. However, water can also be the best media of diseases to spread. Therefore, before consumed, water has to be processed drinking to eliminate or degrade impure materials up to the safest level. As water becomes more problematic these days, it attracts the attention of drinking water refill depots to. Furthermore, dringking water that produce is not yet legalized and standardized in terms of its process. This research to know determine factors related to bacteriological quality of drinking water product drinking water refill in Semarang City. Methods :This research was an Explanatory Research. Using observation with a cross sectional approach. Samples are determined with standard error of 10% from 49 depots divided proportionally towards the spreading of depots throughout Semarang city. The variables used are a parameter of the bacteriologic number of coliform, E_Coli germs. Data analysis using Test correlation of kontingensi chi-square to know relation between variable. Results: The result of this research shows the relation to the variables using Chi-square test, it is shown that the condition of standard water and the condition of Bacteria of refill drinking water are C = 0,494, p = 0,0001, consequently Ho rejects it. Correlation test of instrument condition and the bacteriologic quality of refill drinking water showed that when C = 0,178, p = 0,447, Ho accepts it. While correlation test of processing of drinking water and the bacteriologic quality of refill drinking water showed that when C = 0,346, p = 0,035, Ho rejects it. Correlation test of hygienic officer of depot and the bacteriologic quality of refill drinking water shows that when C = 0,263, p = 0,162, so Ho accepts it. And correlation test of DAMIU sanitation and the bacteriologic quality of refill drinking water showed that C = 0,512, p = 0,0001, so Ho rejects it. Conclusions : All depots have not yet met the requirements of producing standard water as requested by Department of Health. The hygienic behavior of workers is still poor. The bacteriologic quality of refill drinking water based on the result of lab. test indicates that 34 samples ( 69,4%) have fulfilled the requirements of standard drinking water but the rest have not yet reached the minimum standard of drinking water. This matter is caused by the standard water which is used, the procedure of processing and the environmental condition of depot. Keyword; drinking water, refill depots, bacteriology quality

When implementing anion exchange (AEX) for per- and polyfluoroalkyl substances treatment, temporal drinking water quality changes from concurrent inorganic anion (IA) removal can create unintended consequences (e.g., corrosion control impacts). To understand potential effects, four drinking water-relevant IAs (bicarbonate, chloride, sulfate, and nitrate) and three gel-type, strong-base AEX resins were evaluated. Batch binary isotherm experiments provided estimates of IA selectivity with respect to chloride ( ) for IA/resin combinations where bicarbonate < sulfate ≤ nitrate at studied conditions. A multi-IA batch experiment demonstrated that binary isotherm-determined values predicted competitive behavior. Subsequent column experiments with and without natural organic matter (NOM) allowed for the validation of a new ion exchange column model (IEX-CM; https://github.com/USEPA/Water_Treatment_Models). IA breakthrough was well-simulated using binary isotherm-determined values and was minimally impacted by NOM. Initial AEX effluent water quality changes with corrosion implications included increased chloride and decreased sulfate and bicarbonate concentrations, resulting in elevated chloride-to-sulfate mass ratios (CSMRs) and Larson ratios (LRs) and depressed pH until the complete breakthrough of the relevant IA(s). IEX-CM utility was further illustrated by simulating the treatment of low-IA source water and a change in the source water to understand the resulting duration of changes in IAs and water quality parameters.

The ever-growing population of India, along with the increasing competition for water for productive uses in different sectors – especially irrigated agriculture and related local water systems and drainage – poses a challenge in an effort to improve water quality and sanitation. In rural and peri-urban settings, where agriculture is one of the main sources of livelihood, the type of water use in irrigated agriculture has complex interactions with drinking water and sanitation. In particular, the multi-purpose character of irrigation and drainage infrastructure creates several interlinks between water, sanitation (WATSAN) and agriculture and there is a competition for water quantity between domestic water use and irrigated agriculture. This study looks at the determinants of the microbiological quality of stored drinking water among households residing in areas where communities use different types of irrigation water. The study used multiple tube fermentation method 'Most Probable Number' (MPN) technique, a WHO recommended technique, to identify thermotolerant fecal coliforms and E. coli in water in the laboratory (WHO 1993). Overall, we found that the microbiological water quality was poor. The stored water generally had very high levels of Escherichia coli (E. coli) contamination, 80% of the households had water in storage that could not be considered potable as per the World Health Organization (WHO) standards, and 73% of the households were using a contaminated water source. The quality of household storage water was largely unaffected by the major household socioeconomic characteristics, such as wealth, education level or social status. Households using surface water for irrigation had poor drinking water quality, even after controlling for hygiene, behavioral and community variables. Drinking water quality was positively impacted by proper storage and water treatment practices, such as reverse osmosis. Hygiene and sanitation indicators had mixed impacts on the quality of drinking water, and the impacts were largely driven by hygiene behavior rather than infrastructures. Community open defaecation and high village-household density deteriorates household storage water quality.

The ever-growing population of India, along with the increasing competition for water for productive uses in different sectors – especially irrigated agriculture and related local water systems and drainage – poses a challenge in an effort to improve water quality and sanitation. In rural and peri-urban settings, where agriculture is one of the main sources of livelihood, the type of water use in irrigated agriculture has complex interactions with drinking water and sanitation. In particular, the multi-purpose character of irrigation and drainage infrastructure creates several interlinks between water, sanitation (WATSAN) and agriculture and there is a competition for water quantity between domestic water use and irrigated agriculture. This study looks at the determinants of the microbiological quality of stored drinking water among households residing in areas where communities use different types of irrigation water. The study used multiple tube fermentation method ‘Most Probable Number (MPN) technique, a WHO recommended technique, to identify thermotolerant fecal coliforms and E. coli in water in the laboratory (WHO 1993). Overall, we found that the microbiological water quality was poor. The stored water generally had very high levels of Escherichia coli (E. coli) contamination, 80% of the households had water in storage that could not be considered potable as per the World Health Organization (WHO) standards, and 73% of the households were using a contaminated water source. The quality of household storage water was largely unaffected by the major household socioeconomic characteristics, such as wealth, education level or social status. Households using surface water for irrigation had poor drinking water quality, even after controlling for hygiene, behavioral and community variables. Drinking water quality was positively impacted by proper storage and water treatment practices, such as reverse osmosis. Hygiene and sanitation indicators had mixed impacts on the quality of drinking water, and the impacts were largely driven by hygiene behavior rather than infrastructures. Community open defaecation and high village-household density deteriorates household storage water quality.

Pilot Study of Greater Boston Drinking Water Quality Changes - Impacts of Ozonation and Distribution System

Diarrhoeal diseases kill an estimated 2.5 million people each year, the majority being children under 5 years (Kosek et al. 2003). An estimated 4 billion cases annually account for 5.7% of the global burden of disease and place diarrhoeal disease as the third highest cause of morbidity and sixth highest cause of mortality (Pruess et al. 2002). Among children under 5 years in developing countries, diarrhoeal disease accounts for 21% of all deaths (Parashar et al. 2003). By inhibiting normal consumption of foods and adsorption of nutrients, diarrhoeal diseases are also an important cause of malnutrition, leading to impaired physical growth and cognitive development (Guerrant et al. 1999), reduced resistance to infection (Baqui et al. 1993) and potentially long-term gastrointestinal disorders (Schneider et al. 1978). Infectious agents associated with diarrhoeal disease are transmitted chiefly through the faecal-oral route (Byers et al. 2001). A wide variety of bacterial, viral and protozoan pathogens excreted in the faeces of humans and animals are known to cause diarrhoea. Many of these are potentially waterborne – transmitted through the ingestion of contaminated water (Leclerc et al. 2002). Accordingly, a number of interventions have been developed to treat water. These include (i) physical removal of pathogens (e.g. filtration, adsorption and sedimentation); (ii) chemical treatment (e.g. assisted sedimentation, chemical disinfection and ion exchange); or (iii) heat and ultra violet (UV) radiation. Because of the risk of recontamination (Clasen & Bastable 2003), interventions to improve water quality also include steps to maintain the microbiological quality of safe drinking water, such as piped distribution, residual disinfection and improved storage. These efforts are expected to receive additional priority as a result of the United Nation’s commitment to reduce by one-half of the 1.5 billion people without sustainable access to improved water, one of the United Nation’s Millennium Development Goals (United Nations 2000), and by the World Health Organization’s steps to accelerate the health gains of safe water to the remaining population by improved treatment and storage of water at the household level (Sobsey 2002). Health authorities generally accept that safe water plays an important role in preventing outbreaks of diarrhoeal disease (Hunter 1997). Accordingly, the most widely accepted standard for water quality allows no detectable level of harmful pathogens at the point of distribution (WHO 1993). However, in those settings in which diarrhoeal disease is endemic, much of the epidemiological evidence for increased health benefits following improvements in the quality of drinking water has been equivocal (Esrey & Habicht 1986; Lindskog et al. 1987; Cairncross 1989). As many of these same waterborne pathogens are also transmitted via ingestion of contaminated food and other beverages, by person-to-person contact, and by direct or indirect contact with infected faeces, improvements in water quality alone may not necessarily interrupt transmission (Briscoe 1984). As a result of this variety of risk factors, interventions for the prevention of diarrhoeal disease not only include enhanced water quality but also steps to (i) improve the proper disposal of human faeces (sanitation), (ii) increase the quantity and improve access to water (water supply), and (iii) promote hand washing and other hygiene practices within domestic and community settings (hygiene). As in the case of studies of water quality, there is a wide range in the reported measure of effect on diarrhoea morbidity of each of these other environmental interventions (Esrey et al. 1985). Even more fundamentally, there are also questions about the methods and validity of studies designed to assess the health impact of such interventions (Briscoe et al. 1986; Imo State Evaluation Team 1989). As part of a larger evaluation of interventions for the control of diarrhoeal disease (Feachem et al. 1983), Esrey et al. (1985) reviewed 67 studies to determine the health impact from improvements in water supplies and excreta disposal facilities (Esrey et al. 1985). The median reduction in diarrhoeal morbidity from improved water quality was 16% (range 0–90%). This compared with 22% for Tropical Medicine and International Health

Changes in the quality of raw water can significantly affect the treatments necessary for drinking water. Generally, raw water quality assessments are carried out to classify the pollution level of raw waters and cannot be used directly as a control for drinking water treatments. In order to improve the adaptability of drinking water treatments and to stabilize the overall quality of treated water, a raw water quality assessment technique that is specifically related to drinking water treatments is developed in this study. First, a drinking water treatment-oriented raw water quality assessment standard is proposed, based on historical environmental information and an analysis of operational data from drinking water treatments. A raw water quality assessment model is then set up to assess the raw water quality in real time. Finally, the results from this assessment are used to compute feedforward compensation for real-time control of the chemical dosing process, including both alum and ozone in the drinking water treatment. In this way, drinking water treatment can be adjusted according to the temporal changes in raw water quality, thereby stabilizing the quality of treated waters. Experimental implementation of this technique has been carried out in the chemical dosing process control systems of a drinking water treatment plant in China, and the results obtained demonstrate the effectiveness of the raw water quality assessment method proposed herein. This development will be helpful in satisfying the basic requirement of safe drinking water under a worsening global water environment.

Monitoring transformation product formation in the drinking water treatments rapid sand filtration and ozonation

Heterotrophic plate count bacteria—what is their significance in drinking water?

Potential health effects of drinking water quality changes caused by acid precipitation are presented. Several different types of water supply are discussed and their roles in modifying acid rain impacts on drinking water are explained. Sources of metals contamination in surface water supplies are enumerated. The authors present some results from their research into acid rain impacts on roof-catchment cisterns, small surface water supplies, and lead mobilization in acid soils. A good correlation was obtained between cistern water corrosivity as measured by the Ryznar Index (RI) values and standing tapwater copper concentrations. However, lead concentrations in tapwater did not correlate well with cistern water RI. A modified linear regression model that accounted for Ryznar Index change during storage in vinyl-lined cisterns was used to predict the Ryznar Index value at a copper concentration of 1000 micrograms/L. The predicted RI was greater than the RI of precipitation with a pH of 5.3, indicating that anthropogenically acidified precipitation may result in cistern tapwater copper concentrations in excess of the 1000 micrograms/L suggested drinking water limit. Good correlations between tapwater Ryznar Index and tapwater copper and lead concentrations were not obtained for the small surface water supply. Aluminum concentrations in reservoir water were similar to those in stream source water. Limited data were also presented that indicated lead was present in acid forest soil leachate and streams draining such soils in relatively small concentrations. Where appropriate, recommendations for future research are included with the discussions of research results.

the bacteriological quality of drinking water plays a critical role in preventing waterborne diseases. In Ghana, there is water scarcity and many communities depend on contaminated water sources for their domestic use. This study aimed to assess the bacteriological quality of household drinking water in both cholera endemic and non-endemic areas in Greater Accra Region. a community-based cross-sectional comparative survey in cholera endemic and non-endemic communities was conducted. A total of 480 drinking water samples were collected. The membrane filtration technique was used for the quantification of coliform counts and Vibrio counts. The bacteria were further identified and characterized. The Kruskal Wallis rank test was used to determine any significant variations in the means of the log-transformed bacteria counts among specific factor variables. drinking water samples were contaminated with coliform counts exceeding the zero colony-forming units per 100 ml standard in most communities across cholera endemic and non-endemic areas. Vibrio counts were detected in all household water stored in vessels. Further characterization identified predominantly Klebsiella pneumonia and Escherichia coli. The coliform contamination levels were significantly higher in water stored in vessels compared to water directly obtained from the source. The contamination levels were generally higher during the wet season than the dry season. the household's stored drinking water and direct water sources were highly contaminated with coliform bacteria, posing a significant risk for the transmission of pathogenic waterborne diseases. Therefore, the need to implement an effective water treatment strategy to improve the quality of drinking water.