En este trabajo se presenta un Plan de Seguridad del Agua (PSA) para uno de los sistemas de abastecimiento de agua potable de la ciudad de Salta, Argentina. El sistema estudiado se encuentra en Finca las Costas, en las serranías y valles al Oeste de la ciudad. El sistema fue dividido en tres procesos (captación, transporte y tratamiento) y diversos sub-procesos y componentes. Se empleó la metodología de evaluación de riesgos propuesta por la Organización Mundial de la Salud (OMS) complementada con aportes propios. Las adaptaciones consistieron básicamente en: (a) una modificación numérica y cualitativa en la manera de calcular probabilidad, gravedad y riesgo; (b) la definición de un valor umbral de riesgo; y (c) una cuantificación numérica de la magnitud de las medidas de control. El riesgo estimado para todo el sistema fue de 49.1% (magnitud media). El proceso tratamiento de agua recibió el valor de riesgo más elevado (59.1%, magnitud alta). Más del 80% de las situaciones peligrosas identificadas requieren algún tipo de medida de control. Las modificaciones introducidas en el método facilitaron y mejoraron el proceso de evaluación de riesgos. | We describe the Water Safety Plan (WSP) developed for a drinking-water supply system of the city of Salta, Argentina. The system selected was “Finca Las Costas”, located on the hills and valleys West of the city. The system was divided in three processes (catchment, transport, and treatment) and several sub-processes and components. We applied the risk assessment methodology proposed by the World Health Organization (WHO). This methodology was modified with the addition of three innovative steps: (a) a quantitative and qualitative modification of the calculation of probability, severity and risk; (b) the definition of a risk threshold value; and (c) a quantitative calculation of the magnitude of control measures. Current risk for the entire system was 49.1% (medium). Water treatment was found to be the riskiest process (59.1%, high). More than 80% of the hazardous situations studied require some type of control measure. Modifications introduced to the method allowed a more accurate and easier risk assessment process. | Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES)

A estrutura de segurança da água para consumo humano proposta pela Organização Mundial da Saúde e incluída na legislação brasileira é baseada na gestão de riscos à saúde, com a elaboração de Planos de Segurança da Água (PSAs) pelos fornecedores. No Brasil, cerca de 29,9 milhões de pessoas residem em localidades rurais, das quais 72,7% dependem de soluções alternativas de abastecimento e, embora existam iniciativas de aplicação de PSAs em pequenas comunidades, ainda permanecem lacunas de materiais oficiais direcionados a sistemas de pequeno porte. Este trabalho tem como principal contribuição a adaptação das ferramentas metodológicas que compõem a elaboração dos PSAs à avaliação de riscos no contexto das soluções alternativas coletivas (SACs) localizadas em áreas rurais. Para tanto, foi aplicada uma metodologia adaptada de identificação de perigos potenciais a uma SAC do município de Travesseiro (RS). Os resultados desse processo evidenciaram a importância da avaliação de sistemas desse tipo refletida na insuficiência de dados sobre a infraestrutura de abastecimento, a escassez de medidas de controle implementadas, dada a desinfecção como única barreira entre os perigos e os consumidores e a ausência de sistemas de monitoramento em todos os níveis. Diante disso, destacou-se a essencialidade da elaboração de protocolos de monitoramento operacional e planejamento de melhorias no âmbito do desenvolvimento de PSAs simplificados e a potencialidade da produção de subsídios para os instrumentos de gestão de recursos hídricos e investimentos em saneamento. Finalmente, os resultados substanciam a proposta de construção de banco de dados nacional para identificação de perigos potenciais e de que a avaliação seja estendida a toda a cobertura de abastecimento, permitindo que o mapeamento de perigos informe a tomada de decisões. | The drinking-water safety framework proposed by the World Health Organization and included in Brazilian legislation is based on the management of health risks, with the elaboration of Water Safety Plans (WSP) by suppliers. In Brazil, about 29.9 million people live in rural locations, of which 72.7% depend on alternative supply solutions and, although there are initiatives to apply WSPs in small communities, there are still gaps in official materials directed to small-scale supply systems. This study aims to contribute with the adaptation of the methodological tools that make up the elaboration of WSPs to the risk assessment in the context of Brazilian alternative collective solutions (SACs) located in rural areas. Therefore, an adapted methodology for identifying potential hazards was applied to a SAC in the municipality of Travesseiro (RS). The results of this process highlighted the importance of evaluating systems of this type, reflected in the insufficiency of data on the supply infrastructure, the scarcity of implemented control measures, given disinfection as the only barrier between hazards and consumers and the absence of monitoring at all levels. In view of this, the essentiality of the elaboration of operational monitoring protocols and improvement planning within the scope of the development of simplified WSPs and the potential of producing subsidies for the instruments of water resources management and investments in sanitation was highlighted. Finally, the results substantiate the necessity of a national database to identify potential hazards and the argument for the extension of the assessment to the entire supply coverage, allowing such hazard mapping to inform decision-making.

Um estudo descritivo foi realizado com o intuito de caracterizar os casos de doença diarreica aguda e a qualidade da água distribuída em localidades cobertas pelo Programa Saúde da Família, no período de janeiro de 2006 a dezembro de 2008, no município de Viçosa-MG. O estudo foi enriquecido com a integração entre as metodologias quantitativa e qualitativa e com a utilização de diferentes ferramentas de análise, a exemplo da análise espaço-temporal dos casos de doença diarreica aguda e da teoria psicossocial da representação social, no esforço para conhecer a percepção da população a respeito da água que consomem. Houve concentração dos casos de doença diarreica aguda nos trimestres correspondentes ao inverno e maior incidência na faixa etária de menores de 1 ano, sendo o plano de tratamento mais recomendado A, o que indica a pouca gravidade dos casos. A análise espaço-temporal demonstrou concentração dos casos de doença diarreica aguda nas localidades de Nova Viçosa e Nova Viçosa-Posses. Os dados de qualidade da água distribuída estavam, de modo geral, em conformidade com o padrão de potabilidade preconizado pela legislação, o que sugere que outros parâmetros e, ou, critérios deveriam ser levados em consideração pela Vigilância da Qualidade da Água para Consumo Humano. A utilização, por exemplo, de banco de dados sobre reclamações e queixas feitas pela população ao responsável pelo controle da qualidade da água demonstrou ser uma alternativa viável. Os resultados do estudo qualitativo demonstraram a objetivação da água pelo indivíduo em parâmetros físicos e microbiológicos, associados a características organolépticas, evidenciando a primordial importância do conhecimento da percepção do indivíduo e de suas demandas em relação à água que consome, no sentido de direcionar tomadas de decisão e ações que visem garantir o consumo de água segura pela população. | A descriptive study was carried out to characterize acute diarrhea disease and quality of water distributed in localities covered by the Family Health Program, from January 2006 to December 2008 in Viçosa-MG. The study included the integrated quantitative and qualitative methodologies and the use of different analysis tools, such as the space-time distribution analysis for acute diarrhea cases and the psychosocial theory of social representation, attempting to obtain an insight on the perception the population had about the water consumed. There was a concentration of cases of acute diarrhea disease in the three winter months and a higher incidence in the under 1-yearold age range, with treatment A being the most recommended, indicating the little gravity of the cases. The time spatial distribution analysis showed concentration of the cases of acute diarrhea disease in the localities of Nova Viçosa and Nova Viçosa-Posses. The data on the quality of the water distributed were in general in compliance with the drinking water standard recommended by the legislation, suggesting that other parameters or criteria be taken into account by the Water Quality Surveillance for Human Consumption. The use, for instance, of a data bank of the complaints made by the population to the professional in charge of water quality control was shown to be a viable alternative. The qualitative study results showed that the population classified water based on physical and microbiological parameters, associated to organoleptic characteristics, stressing the foremost importance of knowing the individual's perception and his /her water consumption demands, aiming at decision-making processes and actions to guarantee safe water consumption by the population. | Escola de Saúde Pública do Estado de Minas Gerais

Abstract: The city of San Cristobal de Las Casas, Chiapas, Mexico lacks information on the microbiological quality of the municipal drinking water distribution system. Therefore, the risks associated with its intake and the impact it has on public health is unknown. This study assessed the risk of microbial contamination from the Potable Water and Sewerage Municipal (SAPAM) water sources, by conducting a Quantitative Microbiological Risk Assessment (QMRA). Samples from each source were analyzed for Escherichia coli. The QMRA and disease burden were calculated using estimates of the concentrations of four reference pathogens (E. coli O157:H7, Campylobacter, rotavirus and Cryptosporidium) based on published ratios between E. coli and the indicated pathogens. All sources showed fecal contamination. The annual probability of infection was higher than the safety threshold set by the EPA on all previously indicated pathogens. The sum of the disease burden was 2.40 × 10-3 DALYs per person per year, much higher than WHO reference level. The risk was not uniform for the entire population, inequalities in the exposure and the risk were found according to the source of supply. This study demonstrates the need to implement improvements in drinking water distribution system to reduce the public heath risk. | Resumen: La ciudad de San Cristóbal de Las Casas, Chiapas, México, carece de información sobre la calidad microbiológica del agua del sistema municipal de distribución de agua potable. Se desconocen, por tanto, los riesgos derivados de su ingesta y el impacto que supone para la salud pública. El presente estudio evaluó el riesgo por contaminación microbiana de las fuentes de agua del Sistema de Agua Potable y Alcantarillado Municipal (SAPAM) mediante la aplicación de una Evaluación Cuantitativa del Riesgo Microbiológico (ECRM). Se analizó la contaminación por Escherichia coli en muestras de agua de todas las fuentes. Para calcular la ECRM y la carga de enfermedad, se estimó la concentración de cuatro patógenos de referencia (E. coli O157:H7, Campylobacter, rotavirus y Cryptosporidium) utilizando datos publicados de la razón de éstos con E. coli. Todas las fuentes presentaron contaminación fecal. La probabilidad de infección anual fue mayor que el nivel de seguridad establecido por la EPA en todos los patógenos. La suma de la carga de enfermedad fue de 2.40 x 10-3 años de vida ajustados por discapacidad (AVAD) por persona/año, mucho más elevada que el nivel de referencia de la OMS. El riesgo no fue homogéneo para toda la población, se encontraron diferencias en la exposición y riesgo, según fuente de abastecimiento. Este estudio demuestra la necesidad de implementar mejoras en el sistema de distribución de agua potable que reduzcan el riesgo para al salud de la población.

Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.

Water inrush from coal-seam floors greatly threatens mining safety in North China and is a complex process controlled by multiple factors. This study presents a mathematical assessment system for coal-floor water-inrush risk based on the variable-weight model (VWM) and unascertained measure theory (UMT). In contrast to the traditional constant-weight model (CWM), which assigns a fixed weight to each factor, the VWM varies with the factor-state value. The UMT employs the confidence principle, which is more effective in ordered partition problems than the maximum membership principle adopted in the former mathematical theory. The method is applied to the Datang Tashan Coal Mine in North China. First, eight main controlling factors are selected to construct the comprehensive evaluation index system. Subsequently, an incentive-penalty variable-weight model is built to calculate the variable weights of each factor. Then, the VWM-UMT model is established using the quantitative risk-grade divide of each factor according to the UMT. On this basis, the risk of coal-floor water inrush in Tashan Mine No. 8 is divided into five grades. For comparison, the CWM is also adopted for the risk assessment, and a differences distribution map is obtained between the two methods. Finally, the verification of water-inrush points indicates that the VWM-UMT model is powerful and more feasible and reasonable. The model has great potential and practical significance in future engineering applications.

A method of evaluating the risk of floor water inrush using principal component logistic regression analysis (PCLRA) and an improved analytic hierarchy process (IAHP) is presented. The approach was validated by a case study at the Yangcheng coal mine in Shandong Province, China. First, the risk assessment index of floor water inrush was determined based on geological and hydrogeological conditions of the study area. Then, a comprehensive evaluation model (CEM), combining PCLRA with IAHP, was constructed to determine the comprehensive weight of each water-inrush evaluation index. Finally, water-inrush risk zoning was determined with GIS. The results show that the CEM, compared with the water-inrush coefficient method (WICM) traditionally and commonly used in China, has higher fitting accuracy and more detailed division of water-inrush risk areas. This method not only follows the observations in reality, but also fully considers the relative importance of water-inrush evaluation indices. The results can provide a theoretical basis for the safe mining of coal seams above confined groundwater.

Coal-floor water-inrush incidents account for a large proportion of coal mine disasters in northern China, and accurate risk assessment is crucial for safe coal production. A novel and promising assessment model for water inrush is proposed based on random forest (RF), which is a powerful intelligent machine-learning algorithm. RF has considerable advantages, including high classification accuracy and the capability to evaluate the importance of variables; in particularly, it is robust in dealing with the complicated and non-linear problems inherent in risk assessment. In this study, the proposed model is applied to Panjiayao Coal Mine, northern China. Eight factors were selected as evaluation indices according to systematic analysis of the geological conditions and a field survey of the study area. Risk assessment maps were generated based on RF, and the probabilistic neural network (PNN) model was also used for risk assessment as a comparison. The results demonstrate that the two methods are consistent in the risk assessment of water inrush at the mine, and RF shows a better performance compared to PNN with an overall accuracy higher by 6.67%. It is concluded that RF is more practicable to assess the water-inrush risk than PNN. The presented method will be helpful in avoiding water inrush and also can be extended to various engineering applications.

Drinking water quality is of vital importance for the healthy life of a community especially if consumer is a teenager. In order to compare groundwater profile of flooded area (FA) and non-flooded area (NFA) of district Sanghar, 120 water samples from public schools were collected and investigated for physico-chemical parameters, essential metals, trace elements and microbiological indicators. Analysis data revealed that 47% samples in FA were contaminated with faecal coliform bacteria as compared to only 8.3% in NFA. On the other hand, chemical indicators like TDS, Ca, Na, K, SO4, Mg and hardness were higher in FA. Comparison of trace elements content with WHO guidelines revealed that concentration of Fe, As and Zn was higher in 66.7%, 31.7% and 13.3% water samples, respectively in FA whereas content of these elements was also on higher side in 3.3%, 23.3% and 1.7% samples in NFA, respectively. Health risk assessment due to high concentration of Fe, As and Zn showed that As HRI>1, for children in 35 and 23% water samples in FA and NFA, respectively.