Geographic Information Systems for Water Quality Modeling in the Zhytomyr District Communities

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

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

Biological effect-based monitoring is essential for predicting or alerting to a possible deterioration in drinking water quality. In the present study, a reporter gene assay based on oxidative stress-mediated Pgst-4::GFP induction in the Caenorhabditis elegans strain VP596 (VP596 assay) was assessed for its applicability in evaluating drinking water safety and quality. This assay was used to measure the oxidative stress response in VP596 worms exposed to six ubiquitous components (As3+, Al3+, F-, NO3--N, CHCl3, and residual chlorine) in drinking water, eight mixtures of these six components designed through orthogonal design, ninety-six unconcentrated water samples from source to tap water in two supply systems, and organic extracts (OEs) of twenty-five selected water samples. Pgst-4::GFP fluorescence was not induced by Al3+, F-, NO3--N, and CHCl3, and was significantly enhanced by As3+ and residual chlorine only at concentrations higher than their respective drinking water guideline levels. Pgst-4::GFP induction was not detected in any of the six-component mixtures. Induction of Pgst-4::GFP was observed in 9.4% (3/32) of the source water samples but not in the drinking water samples. However, a notable induction effect was revealed in the three OEs of drinking water, with a relative enrichment factor of 200. These results suggest that the VP596 assay has limited utility for screening drinking water safety by testing unconcentrated water samples; however, it offers a supplemental in vivo tool for prioritizing water samples for an enhanced quality assessment, monitoring pollutant removal performance by drinking water treatment plants, and evaluating water quality in water supplies.

Physicochemical quality of drinking and hot waters in Finnish buildings originated from groundwater or surface water plants

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.

This paper describes how access to a sufficient supply of safe drinking water is essential in maintaining public health. The quality of water and associated health risks vary throughout the world with some regions showing contamination of drinking water by pathogens or high levels of chemical compounds, where elsewhere these are very low and present no problem for human health. Considerable variations also occur on a more local level within countries. This study analyzes the status of public water supply and drinking water quality in towns and rural settlements of Estonia and its possible impact on public health. The basis of the study was the Health Protection Inspectorate database on the water suppliers and water quality. A special study was carried out to determine fluoride content (the main toxic chemical of concern in Estonia) in drinking water. All towns and rural settlements with water supply systems serving at least 100 inhabitants were visited and water samples were taken. The access to public drinking water supplies by counties was analyzed. The exposure of the population to selected chemicals of concern was determined. Estonia is characterized by a large proportion of small water supplies. It makes the safeguarding of water quality and control complicated. The percentage of the population exposed to toxic compounds (fluoride, boron) was small and this occurred mainly in the case of small water supplies. At the same time a considerable amount of the population is influenced by undesirable chemicals (iron, manganese, etc.). These substances are non-toxic but disturb the conditions of water usage and quality of life. The priority in planning and improving public water supply should be given to activities minimizing the health risks from toxic components in drinking water.

The object of the study was the centralized drinking water supply system of the Voronezh Region. The purpose of the study was to assess health risks for the population of the Voronezh Region associated with drinking water quality. Materials and methods: The data of the regional drinking water quality monitoring system, which included monthly sampling and testing of water samples at 553 sites in 32 administrative districts and the city of Voronezh for 8 priority sanitary and chemical indicators (total hardness, concentrations of iron, manganese, nitrates, nitrites, boron, fluorine, and ammonium ions) for the years 2010-2019 were used. To achieve the objective based on monitoring studies of drinking water quality in the water distribution system, four generally accepted stages of risk assessment were implemented including hazard identification, evaluation of dose-response relationship, exposure assessment, risk quantification and characterization. When evaluating the exposure, four calculation scenarios were considered and probable body burdens for children and adults were calculated using the average long-term concentration and 95 percentile of concentration in a separate administrative territory. Results: Regional non-carcinogenic risks estimated on the basis of the average regional concentrations of priority pollutants did not exceed acceptable values (HQ < 1) for 6 of 7 ingredients. Unacceptable risk levels were observed in two of 33 administrative districts due to the presence of nitrates in drinking water (HQ ranged 1.34 to 2.95 for children and equaled 1.26 for adults). Detailed information for separate settlements (control points) using an aggravated scenario helped identify 4 rural settlements in 2 administrative districts with unacceptable risks for the child population of iron in drinking water (HQ up to 2.31), 230 settlements in 27 districts – of nitrates (HQ up to 9.51), one settlement – of boron (HQ = 1.17), and 35 settlements in 13 districts – of fluorine (HQ up to 4.17). Discussion: Summarizing the results of the regional studies of health risks for the population associated with the quality of drinking water, one can testify the shift of the problem to rural settlements where water treatment is practically null. The use of average concentrations of chemicals in drinking water in administrative districts proved to be insufficiently objective and having significant uncertainties. The reduction of uncertainties was achieved by a detailed review of the information for each monitoring site and the use of the 95th percentile concentration of the chemical to assess the health risks for children and adults. Conclusions: With a sufficient degree of certainty, the priority regional indicators determining the unacceptable level of non-carcinogenic risk (HQ > 1) associated with the quality of drinking water include elevated levels of nitrates, fluorine, boron, and iron. Key words: drinking water, centralized water supply, water quality, public health risk.

Research on the Drinking Water in Tartu in the Late 19th Century The 19th century witnessed positive developments in the maintenance of cities. Various medical and healthcare factors had a role in this, including the understanding of drinking water as a relevant component of applied hygiene. Discussions on the quality of water turned vehement after the nature of infectious diseases was explained, i.e., it was proved that they are caused and transmitted by different microorganisms. The presence of bacteria in water and the need for clean drinking water arising from it was still, however, not immediately unequivocal. The approach to cholera is an example of a model situation, where different theories collided. At the turn of the century there were two theories on the spread of the aforementioned infectious disease that also reached Tartu: the drinking water theory (created by Robert Koch) and the so-called groundwater level theory (Max v. Pettenkofer). The first predicated that the disease spreads in drinking water via disease agents. The other theory considered that the existence of certain favourable geological circumstances is relevant. Both theories fitted the scientific context of their times, i.e., they had strengths and weaknesses. Against the backdrop of the concern for the quality of drinking water, academics got involved in the discussion in Tartu as well. The research performed by Bernhard Korber, professor of hygiene at the University of Tartu, and his students persuaded the school of science here to support the drinking water theory. This was the right direction. Korber was socially active, which, in its turn, helped to shape the environment of Tartu in view of health care, including improving the quality of drinking water.

BackgroundPublic health is at risk due to chemical contaminants in drinking water which may have immediate health consequences. Drinking water sources are susceptible to pollutants depending on geological conditions and agricultural, industrial, and other man-made activities. Ensuring the safety of drinking water is, therefore, a growing problem. To assess drinking water quality, we measured multiple chemical parameters in drinking water samples from across Bangladesh with the aim of improving public health interventions.MethodsIn this cross-sectional study conducted in 24 randomly selected upazilas, arsenic was measured in drinking water in the field using an arsenic testing kit and a sub-sample was validated in the laboratory. Water samples were collected to test water pH in the laboratory as well as a sub-sample of collected drinking water was tested for water pH using a portable pH meter. For laboratory testing of other chemical parameters, iron, manganese, and salinity, drinking water samples were collected from 12 out of 24 upazilas.ResultsDrinking water at sample sites was slightly alkaline (pH 7.4 ± 0.4) but within acceptable limits. Manganese concentrations varied from 0.1 to 5.5 mg/L with a median value of 0.2 mg/L. The median iron concentrations in water exceeded WHO standards (0.3 mg/L) at most of the sample sites and exceeded Bangladesh standards (1.0 mg/L) at a few sample sites. Salinity was relatively higher in coastal districts. After laboratory confirmation, arsenic concentrations were found higher in Shibchar (Madaripur) and Alfadanga (Faridpur) compared to other sample sites exceeding WHO standard (0.01 mg/L). Of the total sampling sites, 33 % had good-quality water for drinking based on the Water Quality Index (WQI). However, the majority of the households (67 %) used poor-quality drinking water.ConclusionsHigher values of iron, manganese, and arsenic reduced drinking water quality. Awareness raising on chemical contents in drinking water at household level is required to improve public health.

BACKGROUND AND AIM: Drinking water quality in the U.S has been a growing concern for decades. There is substantial evidence of regulatory violations and the presence of chemical and microbial contaminants that are detrimental to public health in drinking water supplies, but research on water quality disparities is limited. Here, we examined the water quality and demographic characteristics of populations served by community water systems (CWS) in five states: California (CA), New Jersey (NJ), North Carolina (NC), Pennsylvania (PA), and Texas (TX). METHODS: Water quality data for community water systems (CWS) were obtained from the EWG's Tap Water Database for 2010-2017. State specific CWS service area boundaries were overlaid with census tract areas allowing community demographics to be linked to water quality data. Demographic characteristics of the CWS-served population were estimated by proportionally assigning census tract demographic data to the CWS by area and summing across that system. The overall water quality metrics were examined against the racial and ethnic groups served and stratified by system size. Water quality was estimated as a function of the average concentrations of major contaminants: nitrate, arsenic (As), trihalomethanes (THM4), and the cumulative cancer risk (CCR) due to 23 carcinogenic drinking water contaminants. RESULTS:CWS that served proportionally more Hispanic people, regardless of system size, in CA and TX had the overall highest average concentration of nitrates. For NJ, PA, and NC, there were racial/ethnic disparities in the average concentration of As, nitrate, and THM4 in drinking water served by different system sizes. The average CCR also differed across states with risk ranging from 1 X 10-4 to 9 X 10-4. CONCLUSIONS:This study findings indicate the need for federal, state, and local agencies to target racial and ethnic disparities in different regions and communities while seeking solutions to chemical contamination in the U.S drinking water. KEYWORDS: Water quality, risk assessment, multi-pollutant, environmental disparities

Stunting is a nutritional problem that needs attention because of its risk to future generations. The causes of stunting are related to environmental factors such as sanitation and drinking water quality. Intervention efforts are carried out to improve sanitation and drinking water quality, which is regarded as a risk factor. This article reviewed literature relevant to the topic from Science Direct, Scopus, EBSCO (CINAHL, MEDLINE), and Proquest databases from 2020-2024 publications with the keywords Water Quality and Stunting, then analyzed using a synthesis matrix. The inclusion criteria for this study were articles in English with a correlational design and full text. The results of the journal review found six articles that stated that sanitation factors, especially the quality of drinking water, were the cause of the stunting problem. The quality of drinking water is related to bacterial contamination due to disasters (floods), risk factors for unhealthy behavior, and open toilets. Poor water quality causes infection, which indirectly affects other factors that affect linear growth (weight and height), which are indicators of stunting. Interventions reduce the prevalence of stunting by improving sanitation, especially the quality of proper drinking water, and improving clean living behavior in the community.

Comprehensive assessment and visualized monitoring of urban drinking water quality

The paper presents the results of a drinking water quality study in towns located in the mining areas of the Republic of Bashkortostan, The Russian Federation. The objects of the study were underground water supply sources and water distribution networks of the towns of Uchaly, Sibay, and Baimak. In total, 30 water wells were examined, and five water samples were collected from the water distribution network in each town. The water quality indicators were pH, solid residue, total hardness, copper content, zinc content, iron content, and manganese content. The water quality in water distribution networks corresponded to the permissible limits according to environmental and sanitary regulations, except for the increased iron contentprobably due to corrosion of water supply pipelines. The water quality in non-centralized water supply (wells) in some areas failed to meet the sanitary standards. Priority indicators of water pollution were increased hardness and mineralization, high content of iron and manganese. To provide the residents with high-quality drinking water, it is proposed to make a complete inspection of centralized and non-centralized water sources not only within the towns, but also in the neighbouring communities. It is necessary to install filtration plants, primarily to reduce the iron content, in roder to bring the water taken from the wells for household and drinking purposes to the standard quality.

Sunstainable development principles suggest that health effects are associated with the result of complex issues affecting air, soil and water. In some areas in Indonesia, such as South Kalimantan province, water quality has been a problem due to both natural environmental hazards and anthropogenic activities. One of the water borne diseases which results as a sign of permanent damage to health is dental decay. Teeth also can provide an excellent record of nutritional status and environmental exposure.The Indonesian Basic Health Research Survey (2008) showed that the prevalence of dental decay was extremely high (83. 6 %). In addition, only 40 % of the people have access to a good quality source of drinking water and much of the drinking water quality was poor (58. 6 %). Tooth decay is a multi-factorial disease, related to socio-behavioural risk: unhealthy diet, poor oral hygiene, individual susceptibility; hereditary factors, and environmental risk factors. The aims of this research are to study the association between drinking water quality and the severity of dental caries in school children as well as investigate the associated environmental risk factors from the perspective of sustainable development principles. In this dissertation, quantitative & Qualitative methods are employed in a cross sectional study, with oral health examinations of 600 school children in 2 age group, 6 and 12 years old, of 300 children each.Study location covered 20 villages, 3 districts, in South Kalimantan Province, Indonesia. Interviewers investigated social risk factors. Drinking water samples were collected from 20 villages and tested through the laboratory analyses. To strengthen the evidence of the environmental exposure, a dental analysis using Laser Ablation Inductively Couple Plasma Mass Spectrometry (LA-ICP-MS) examined trace elements in selected 30 exfoliated deciduous teeth from the sample of 600 children. The study shows the prevalence of tooth decay is 99,7%; on average there are 11 decayed, exfoliated or filled deciduous teeth per person. This finding exceeding the target of oral global health set by WHO is of 50%, and no more than 7 tooth decay. Laboratory findings showed that 30 % of drinking water is outside the normal pH range of 6.5-8.5. Then, 95 % of fluoride concentration is below the optimum level (0.7 ppm) to prevent dental caries. In certain areas, manganese concentration exceeds the safety level of 0.4 ppm. Bivariate analysis showed significant correlations (p<0.05); the more acidic water, the lower the fluoride, the higher the dental caries. Manganese is positively associated with dental caries in deciduous teeth. The potential resource of manganese in this study found is the study site close to mining area. Turbidity and colour shows significant association with permanent teeth decay. Multivariate analysis shows covariate factors positively associated with tooth decay are oral hygiene index and consumption of sweet food, and inversely associated with consumption of milk and fruit. The result of mass Spectrometry through LA-ICP-MS shows that an individual has a unique pattern resulting from different concentration of trace elements in the tooth. Bivariate analysis showed significant (p<0.05) but moderate correlations between the dental caries index and concentrations of tin, mercury and uranium in dentine and inversely with copper in enamel. Concentration of fluoride in water is inversely correlated with selenium, tin, cerium, and lead in enamel, selenium and lanthanum in dentine and positively associated with, samarium, erbium in dentine. Water pH is positively correlated with arsenic and uranium in enamel and with samarium in dentine, and inversely with selenium in enamel and dentine. Socio-behavioural patterns vary among the school children in different villages. The findings support views of people that they have tooth decay due to poor quality water and that many teenagers failed the health examination of Army School entry test, in large part due to teeth decay. Hence, tooth decay also reflects poor environmental conditions and has consequences for future socio-political life, education and employment. A potential approach using local wisdom and applying religious approach in innovative methods in oral health promotion was also identified. Identification of trace elements in the teeth of schoolchildren was undertaken in order to associate levels with caries experience and the quality of local drinking water in communities with distinctive environmental conditions. Tooth decay in school children is highly prevalent and related to poor drinking water quality in certain areas. This needs to be taken into account as a potential indicator of general environmental problems. Interventions are not only treatment of cases and minimizing human exposures but also integrated action from sectors that generate environmental health threats. Environmental risk factors need to be taken into account as the subject of oral health promotion in preventing the high incidence of dental caries in school children.

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.