Drinking water companies have the technology and responsibility to deliver safe and high-quality drinking water to the water distribution systems network (WDN). However, many events within the WDN, such as cross-connections and backflow, might degrade water quality and pose public health risks to consumers. Cross-connection and backflow events may occur if there is physical contact between the external non-potable water source and the drinking water. When the pressure in the external source is greater than in the WDN, and when there are inadequate cross-connections controls, cross-connections and backflows may occur. This project aimed to investigate the circumstances that influence cross-connection and backflow events and estimate the health risk of infection. The method used for this study included hydraulic and water quality modeling EPANET to simulate the fate and transport of pathogens in the WDN during the outbreak. Besides, the quantitative microbial risk assessment QMRA was used to evaluate the health risks associated with cross-connections and backflow events due to ingestion of contaminated water. The modeled events included four reference pathogens (viruses: Norovirus and Rotavirus, bacteria: Campylobacter, and protozoa: Cryptosporidium) from four water types (wastewater, greywater, treated wastewater, and treated greywater). The simulation considered three potential pathogen load risk levels entering WDN: extreme, evaluated, and endemic. The results indicate that the factors that influence pathogen intrusion and consequently the risk of infection were the duration and intensity of the low-pressure event, the location of the cross-connection, and the pathogen concentration in water sources. The estimated daily risk of infection from cross-connection and backflow events generally exceeded the acceptable target level of 10−6 per person per day for all reference pathogens and modeled events. The exception was for the endemic risk level during the cross-connections with treated wastewater and greywater, where the risk was 10−7 and 10−10. Several measures can be implemented to manage and mitigate the risk of cross-connections, such as demanding plumbing installation procedures and backflow prevention devices and developing an early detection system to predict the cross-connection earlier before the outbreak happens to the system, for instance, by applying a machine learning system. / Vattenreningsindustrin har tekniken och ansvaret för att leverera säkert och högkvalitativt dricksvatten till nätverket för vattendistributionssystem (WDN). Däremot många händelser inom WDN, såsom korskopplingar och återflöde, kan försämra vattenkvaliteten och utgöra folkhälsorisker för konsumenterna. Korskoppling och återflödeshändelser kan inträffa om det finns fysisk kontakt mellanden externa vattenkällan för icke dricksvatten och dricksvattnet. När trycket i den externa källan är högre än i WDN, och när det finns otillräckliga korskopplingskontroller, kan korskopplingar och återflöden inträffa. Syftet med detta projekt var att undersöka omständigheterna som påverkar korskopplings- och återflödeshändelser samt uppskatta hälsorisken för infektion. Metoden som användes för denna studie inkluderade hydraulisk och vattenkvalitetsmodellering med EPANET för att simulera transporten och förekomsten av patogener i WDN under utbrottet. Dessutom användes kvantitativ mikrobiell riskbedömning (QMRA) för att utvärdera hälsoriskerna i samband medkorskopplingar och återflödeshändelser på grund av intag av förorenat vatten. De modelleradehändelserna inkluderade fyra referenspatogener (virus: Norovirus och Rotavirus; bakterier:Campylobacter; och protozoer: Cryptosporidium) från fyra vattentyper (avloppsvatten, gråvatten, renatavloppsvatten och renat gråvatten). Simuleringen beaktade tre potentiella patogenbelastningsrisknivåer som kommer in i WDN: extrem, utvärderad och endemisk. Resultaten tyder på att de faktorer som påverkar patogenavbrott och följaktligen risken för infektionvar lågtryckshändelsens varaktighet och omfattning, platsen för korskopplingen och patogenkoncentrationen i vattenkällor. Den uppskattade dagliga risken för infektion från korskopplingoch återflödeshändelser översteg i allmänhet den acceptabla målnivån på 10e6 per person och dag föralla referenspatogener och modellerade händelser. Undantaget var den endemiska risknivån vidkorskopplingarna med renat avloppsvatten och gråvatten, där risken var 10e7 och 10e10. Flera åtgärder kan implementeras för att hantera och minska risken för korskopplingar, såsom atttillämpa krav på installationsprocedurer för VVS och anordningar för att förhindra återflöde samt attutveckla ett system för tidig upptäckt för att förutsäga korskopplingen tidigare innan utbrottet inträffarmed systemet, till exempel genom att tillämpa ett maskininlärningssystem.

Drinking water systems aim to remove, reduce, and prevent microbial contamination in water by usingmultiple barriers from catchments to consumers. Water distribution networks are vulnerable tocontamination from external sources if they lose their physical or hydraulic integrity. The leading causeof intrusion is losing hydraulic integrity due to low pressure in the water distribution networks. Eventsthat lead to low pressure in the water distribution networks can result in transient or sustained lowpressure lasting from milliseconds in a transient to hours and days in sustained low-pressure events.This study studied two sustained low-pressure events with durations of one to five hours, leading tointrusion in the water distribution network. The first event was the pump shut down, and the secondwas the pipe repair. Different durations, start times, and locations were simulated for the pumpshutdown and pipe repair events. Hydraulic and water quality modelling using EPANET 2.2 was usedto simulate low-pressure events and intrusion of microbial contamination in the drinking waterdistribution networks. Quantitative microbial risk assessment (QMRA) was used to estimate potentialpublic health risks using the Swedish QMRA tool. Campylobacter, Norovirus, and Cryptosporidiumwere selected as reference pathogens for simulating intrusion transport within the drinking waternetwork based on their health problem severity, persistence in water supplies, and resistance to chlorinecompound disinfectants. The study area was taken from the virtual network files generated usingHydroGen. This study showed that the volume of intrusion depended on the magnitude but mainly onthe duration of pressure drop. Also, the length of the pipes experiencing pressure drop and the numberof intrusion nodes affected the volume of intrusion. The location and magnitude of maximum nodalpathogen concentration changed significantly by changing the pump shutdown's start time and locationof pipe repair. Generally, the pump shutdown event affected extended areas with low pressure in thewater distribution network than the pipe repair. The QMRA results showed a considerable infection riskin all studied pump shutdown scenarios. The pipe repair duration was crucial in increasing or decreasingthe infection probability. The findings of hydraulic modelling and QMRA could benefit the watermanagers in deciding mitigation strategies.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated. In addition to normal operation, a number of scenarios were examined. This is to investigate how water treatment would do if they became a reality. The thesis has examined Borg´s waterworks operated by Norrköping Vatten AB. It was defined to cover the distance from water source to the consumer. In the work, the model Quantitative Microbial Risk Assessment (QMRA) was used to perform risk analysis by simulating the normal operation and different scenarios of the water purification process. Thus, knowledge can be obtained about the effectiveness of separation by bacteria, viruses and parasites. However, the QMRA-model is considered to contain some flaws and for that reason the Norwegian model called Good Disinfection Practice (GDP) was also used. GDP is a theoretical model which is based on formulas and tables. The model takes into account the raw water quality and also provides deductions for various measures that the water plant possesses to ensure a good supply of water. The results obtained with both models were similar and showed that the water treatment is sufficient for the bacteria, but not viruses and parasites. Both models were considered to be reliable but viruses and parasites are very difficult to analyze, which has resulted in uncertain literature values and hence in the results. The result also showed that neither viruses nor parasites exceeded the limit by so much that more hygienic barriers to the reduction of them are necessary. The conclusion which may be drawn from the fact that no parasites have been detected in the raw water is that the water treatment still might be sufficient. To determine the effects that an exclusion of various barriers may give, the normal operation was simulated and a purification step at a time was excluded. The result showed that the purification steps which are most important to maintain the treatment process are chemical precipitation followed by rapid filtration, slow filtration and disinfection with chlorine. If any of these cleaning steps were to fail, this introduces a large increase in the risk of waterborne disease. The results showed that the chemical precipitation step gave the greatest separation effect on the virus but also on the parasites. However, the slow filtration gave the largest separation of the parasites. Free chlorine had the greatest effect on bacteria. The investigated scenarios were assumed to be wastewater discharges, sewage discharges in relation to flood the nearby pastures, and sewage overflows due to heavy rainfall. The results of the simulated scenarios were the same when it was only bacteria that in all cases produced a result within the limits of the daily infection probability. Both viruses and parasites exceeded both values. However, there were few studies on these and thus literature values needed to be implemented in the QMRA-model. Hence, the uncertainty of the results was great. The QMRA-model also contained deficiencies in the simulation of the discharge of effluents, where the amount of virus was about 1000-10000 times too much. If this problem as well as more specific data for the investigated area, and more Swedish studies were available, a more credible simulation of the scenarios could be implemented.

Yes / This paper presents a study to assess the roof-harvested rainwater (RHRW) in the Ikorodu area of Lagos state, Nigeria, and recommends guidance to minimise the health risk for its households. The types, design and use of rainwater harvesting systems have been evaluated in the study area to inspect the human risk of exposure to Escherichia coli (E. coli). To achieve these objectives, a detailed survey involving 125 households has been conducted which showed that 25% of them drink RHRW. Quantitative microbial risk assessment (QMRA) analysis has been used to quantify the risk of exposure to harmful E. coli from RHRW utilised as potable water, based on the ingestion of 2 L of rainwater per day per capita. Results have revealed that the maximum E. coli exposure risk from the consumption of RHRW, without application of any household water treatment technique (HHTTs) and with application of alum only, were 100 and 96 respectively, for the estimated number of infection risk per 10,000 exposed households per year. This estimation has been done based on 7% of E. coli as viable and harmful. Conclusively, it is necessary that a form of disinfectant be applied to the RHRW before use.

In low-resource contexts, household-level point-of-use water treatment (POUWT) techniques are the final, and sometimes only, barrier against waterborne illnesses, and in these and other water-related applications, health risks can be quantified using one of two methods. Firstly, Escherichia coli (or other indicator organism) counts can be used to monitor water and determine adherence to a health-based limit (i.e. compliance monitoring). Secondly, E. coli can be used to conduct a quantitative microbial risk assessment (QMRA), indicating the level of protection conferred by a given POUWT device by spiking test water with E. coli to ascertain a reduction efficacy relative to that target organism, a process referred to as challenge testing, which is typically carried out in a laboratory context. Although both methods are well established, both have scope for improvement for effective field application in low-resource contexts. Regarding compliance monitoring, I assessed the performance of a new low-cost field kit for E. coli enumeration, which was designed by others. I also assessed the feasibility of re-using some disposable materials, in terms of sterility and mechanical wear. The use of the new low-cost field kit was successful during the fieldwork campaign; however, re-using disposable materials introduced a relatively high occurrence of false positive results during E. coli enumeration. Use of the new low-cost field kit can reduce financial barriers, thus enabling greater water quality testing coverage. Regarding challenge testing, the aim of this study was to adapt current protocols to assess the household performance (as opposed to laboratory performance) of POUWT techniques. I developed a conceptual framework to conduct Field Challenge Tests (FCT’s) on POUWT techniques, using a probiotic health supplement containing E. coli as the challenge organism. I successfully carried out a FCT in Malawi with limited resources, verifying FCT viability. Applications of such FCT’s include quality control practices for manufactured devices, guiding QMRA and recommendations by public health organizations regarding POU device selection, and assessing the impact of user training programmes regarding POUWT techniques. / Graduate

O uso das águas costeiras para fins recreacionais está associado com benefícios à saúde e bem-estar, todavia eventuais impactos negativos podem diminuir estes benefícios. Esses usos variam de acordo com o tipo de atividade desenvolvida, sendo que a recreação de contato primário requer contato direto e prolongado com a água, durante a qual pode ocorrer ingestão acidental. A Resolução CONAMA nº 274/2000 dispõe sobre os critérios de balneabilidade e reza que as condições da qualidade das águas recreacionais devem ser avaliadas através de indicadores microbiológicos de contaminação fecal, e ainda recomenda que seja realizada pesquisa de organismos patogênicos em praias sistematicamente impróprias. Dada a escassez de dados da ocorrência de patógenos em águas costeiras, no período de 2010 a 2012, a CETESB realizou o Estudo de microrganismos patogênicos nas praias do Litoral Paulista pesquisando enterovírus, adenovírus, vírus da hepatite A, Cryptosporidium sp e Giardia sp, no intuito de preencher esta lacuna e gerar dados primários. Assim, o objetivo deste trabalho foi estimar a probabilidade de infecção por Cryptosporidium sp e Giardia sp após exposição a águas recreacionais costeiras usando como ferramenta a Avaliação Quantitativa de Risco Microbiológico (AQRM), como também o risco de doença. As concentrações de (oo)cistos nas águas das praias são oriundas dos relatórios de Qualidade das Praias Litorâneas no Estado de São Paulo da CETESB dos anos de 2011 e 2012. Nesse período foram analisadas 203 amostras coletadas de 12 praias na 1ª fase e de cinco praias na 2ª fase para a pesquisa de ocorrência de (oo)cistos. As amostras de água foram coletadas na isóbata de um metro, com frequência mensal. Giardia sp foi o microrganismo mais frequente, presente em 43 por cento das amostras e Cryptosporidium sp em 13 por cento . O cenário de exposição considerou tipos de atividade, tipos de usuários (crianças, adultos e esportistas), concentração de (oo)cistos, volume de ingestão, duração e frequência da exposição. A probabilidade de infecção foi maior em praias com mais amostras positivas para oocistos e cistos, no grupo dos esportistas e para Giardia sp. Em alguns casos os valores de risco de doença ultrapassaram o risco tolerável pela U.S. EPA (2012) de 3,6 por cento casos de gastroenterite, assim como ultrapassaram os resultados de incidência acumulada encontradas por LAMPARELLI et al. (2015). Os resultados apontaram a necessidade de melhoria nos sistemas de tratamento de efluentes no Litoral Paulista. A AQRM é uma ferramenta capaz de estimar a probabilidade de infecção no cenário das águas recreacionais e pode auxiliar no gerenciamento dos riscos. / The use of coastal water for recreational purposes has been associated with benefits to health and well-being; however some negative impacts can diminish such benefits. The usages can vary according to the type of activity but the primary contact demands physical contact resulting in a high probability in accidental ingestion of water. Brazilian legislation for coastal recreational waters CONAMA 274/2000 establishes criteria for fecal indicator bacteria and furthermore recommends investigation of pathogenic organisms for beaches which classification is systematically as improper. Given the scarcity of data referring to pathogenic presence in beaches´ waters, CETESB carried out a study, in 2010 and 2012, for quantifying enterovirus, adenovirus, hepatitis A virus, Cryptosporidium sp and Giardia sp in coastal waters of São Paulo state in order to obtain data about their occurrence of these pathogens in coastal waters. The objective of this study was to estimate the annual risk of infection and disease for Giardia sp and Cryptosporidium sp by ingestion of water during primary contact recreation using QMRA approach. Concentrations of both parasites were taken from the annual report entitled Quality of coastal beaches in São Paulo state by CETESB (2011 and 2012). In these years were analyzed 203 samples of water for quantifying (oo)cysts of Giardia and Cryptosporidium from 12 beaches in the first year and five beaches in the second year of research. The samples were collected at one meter isobaths, with monthly frequency. Giardia was the most frequent parasite present in 43 per cent of samples and Cryptosporidium sp in 13 per cent . Exposure scenario was built considering types of activity, beach goers (children, adults and athletes), concentration of parasites, ingestion rate, duration and frequency of exposure. The probability of annual infection was higher in beaches in which there were more positive results for parasites for athletes and for Giardia infection. The tolerable risk for gastroenteritis by USEPA, which is 3.6 per cent , was overpassed in some cases. Though the results found in this study overpassed the cumulative incidence reported by LAMPARELLI et al. (2015). The results indicate the need for improvements in wastewater treatment systems in the coastal area of São Paulo. As QMRA is a tool capable in estimating the probability of infection it can help to highlight crucial issues in risk management.

Introdução - A prática de reúso pela aplicação de esgotos tratados na agricultura atualmente é considerada parte integrante dos recursos hídricos por muitas nações. No entanto, oferece riscos à saúde da população pela presença de bactérias, cistos de protozoários, ovos de helmintos e vírus, capazes de sobreviver por longos períodos em ambientes desfavoráveis e apresentarem um curto tempo entre a infecção e o desenvolvimento da doença. Objetivo - Estabelecer medidas preventivas para o lançamento de efluentes nos ecossistemas aquáticos, controle sanitário na redução de patógenos transmitidos por águas contaminadas e a disposição de efluentes tratados em solos tropicais como ferramentas de auxílio do manejo integrado dos recursos hídricos em bacias hidrográficas, por meio do uso de metodologia de gerenciamento de risco com aplicação do Sistema APPCC, em um conjunto de tecnologias na produção de efluente tratado de esgoto de origem doméstica para avaliar o potencial de emprego em solos agrícolas. Métodos - A pesquisa foi desenvolvida na estação de tratamento de esgoto e no campo experimental para pesquisas de utilização de efluente na agricultura no município de Lins. Os indicadores biológicos estudados e os pontos de amostragem foram determinados através da utilização da metodologia de controle de qualidade Análise de Perigos e Pontos Críticos de Controle (APPCC). Foram coletadas amostras do solo irrigado e dos poços de monitoramento do lençol freático. As amostras foram submetidas a análises físico-químicas, microbiológicas e parasitológicas. Aos resultados obtidos foi aplicada a Avaliação Quantitativa do Risco Microbiológico, para a determinação do risco anual de infecção. Resultados - O efluente final apresentou concentrações médias de 8,13x105 NMP/100 mL de coliformes totais e 4,69x105 NMP/100 mL de Escherichia coli, não sendo observados ovos de helmintos. O solo apresentou maior concentração de coliformes totais e E. coli na camada superficial 1,01x106 e 8,70x103, diminuindo ao longo da profundidade. Os ovos de helmintos foram encontrados entre a superfície e os 15 cm de profundidade em concentrações entre 0,07 e 0,87 ovos/g de peso seco. Foi constatada a presença de adenovírus em concentração de 3,56x105 cópias genômicas/g entre os 5 e 10 cm de profundidade em 2015. Nos poços de monitoramento foram constatadas concentrações de coliformes totais variando entre < 1,00 e 1,01x103 NMP/100 mL e E. coli entre <1,00 e 1,00x100 NMP/100 mL. Não foi observada a presença de vírus entéricos. O risco anual de infecção estimado para E. coli no efluente final foi 1,02x10-2 pppa, no solo variou entre 2,68x10-3 e 7,59x10-3 pppa e nos poços de monitoramento variou entre 1,42x10-8e 4,38x10-9 pppa. Para os ovos de helmintos observados no efluente do tratamento primário o risco anual de infecção calculado foi 4,04x10-2 pppa e no solo variou entre 9,57x10-1 e 9,76x10-1 pppa. Conclusões No período da pesquisa, as amostras dos sistemas de tratamento de esgoto e de irrigação demonstraram atender as expectativas de remoção de patógenos condizentes aos seus parâmetros de projeto, havendo restrições para seu lançamento em corpos hídricos e aplicação na agricultura. O solo mostrou capacidade de retenção dos organismos patogênicos nos primeiros 60 cm de profundidade, reduzindo as suas concentrações a níveis inferiores a 1,00 NMP/100 mL nos aquíferos. / Introduction - Currently, the practice of reuse through the application of treated sewage in agriculture considers an integral part of water resources for many nations. However, threatens the health of the population by the presence of bacteria, protozoan cysts, helminth eggs and viruses able to survive for long periods in harsh environments and present a short time between infection and development of disease. Objective - Establish preventive measures for the release of effluents on aquatic ecosystems, sanitary control in the reduction of pathogens transmitted by contaminated water and the disposal of treated effluent in tropical soils as aid tools in integrated management of water resources in river basins. For this purpose it was employed as risk management methodology the Hazard Analysis and Critical Control Points system (HACCP) in a set of technologies in the treated effluent production of domestic sewage to assess the employment potential in agricultural soils. Methods - The study was conducted in the sewage treatment plant and in an adjoining experimental field situated at Lins city. The biological indicators and the sampling points were determined by using the quality control methodology Hazard Analysis and Critical Control Points (HACCP). Samples of irrigated soil and groundwater monitoring wells were collected. The samples were subjected to analysis, physical-chemical, microbiological and parasitological. The results obtained was applied to Quantitative Microbial Risk Assessment (QRMA), for determining the annual risk of infection. Results - The final effluent presented average concentrations of 8.13x105 MPN / 100 mL of total coliforms and 4.69x105 MPN / 100 mL of Escherichia coli, not being observed helminth eggs. The soil showed the highest concentration of total coliforms and E. coli in the surface layer and 1.01x106 8.70x103, decreasing along the depth. Eggs from helminths were found between the surface and 15 cm depth in concentrations from 0.07 to 0.87 eggs / g dry weight. It was found the presence of adenovirus in concentration 3.56x105 genomic copies / g between 5 and 10 cm depth in 2015. In monitoring wells total coliform concentrations were found ranging from <1.00 and 1.01x103 NMP / 100 mL and E. coli between <1.00 and 1.00x100 MPN / 100 mL. It was not observed the presence of enteric viruses. The estimated annual risk of infection to E. coli in the final effluent was 1.02x10-2 pppy, soil ranged from 2.68x10-3 and 7.59x10-3 pppy and monitoring wells ranged from 1.42x10-8 e 4.38x10-9 pppy. For helminth eggs observed in the effluent from the primary treatment, the annual risk of infection was calculated 4.04x10-2 pppy and soil ranged from 9.57x10-1 and 9.76x10-1 pppy. Conclusions - During the survey period, samples of sewage and irrigation treatment systems showed meet the expectation removal of pathogens consistent to its design parameters, with restrictions on its release in water and applied in agriculture bodies. The soil of pathogenic organisms showed retention capacity in the first 60 cm depth by reducing its concentration to levels below 1.00 MPN / 100 mL in aquifers.

O uso das águas costeiras para fins recreacionais está associado com benefícios à saúde e bem-estar, todavia eventuais impactos negativos podem diminuir estes benefícios. Esses usos variam de acordo com o tipo de atividade desenvolvida, sendo que a recreação de contato primário requer contato direto e prolongado com a água, durante a qual pode ocorrer ingestão acidental. A Resolução CONAMA nº 274/2000 dispõe sobre os critérios de balneabilidade e reza que as condições da qualidade das águas recreacionais devem ser avaliadas através de indicadores microbiológicos de contaminação fecal, e ainda recomenda que seja realizada pesquisa de organismos patogênicos em praias sistematicamente impróprias. Dada a escassez de dados da ocorrência de patógenos em águas costeiras, no período de 2010 a 2012, a CETESB realizou o Estudo de microrganismos patogênicos nas praias do Litoral Paulista pesquisando enterovírus, adenovírus, vírus da hepatite A, Cryptosporidium sp e Giardia sp, no intuito de preencher esta lacuna e gerar dados primários. Assim, o objetivo deste trabalho foi estimar a probabilidade de infecção por Cryptosporidium sp e Giardia sp após exposição a águas recreacionais costeiras usando como ferramenta a Avaliação Quantitativa de Risco Microbiológico (AQRM), como também o risco de doença. As concentrações de (oo)cistos nas águas das praias são oriundas dos relatórios de Qualidade das Praias Litorâneas no Estado de São Paulo da CETESB dos anos de 2011 e 2012. Nesse período foram analisadas 203 amostras coletadas de 12 praias na 1ª fase e de cinco praias na 2ª fase para a pesquisa de ocorrência de (oo)cistos. As amostras de água foram coletadas na isóbata de um metro, com frequência mensal. Giardia sp foi o microrganismo mais frequente, presente em 43 por cento das amostras e Cryptosporidium sp em 13 por cento . O cenário de exposição considerou tipos de atividade, tipos de usuários (crianças, adultos e esportistas), concentração de (oo)cistos, volume de ingestão, duração e frequência da exposição. A probabilidade de infecção foi maior em praias com mais amostras positivas para oocistos e cistos, no grupo dos esportistas e para Giardia sp. Em alguns casos os valores de risco de doença ultrapassaram o risco tolerável pela U.S. EPA (2012) de 3,6 por cento casos de gastroenterite, assim como ultrapassaram os resultados de incidência acumulada encontradas por LAMPARELLI et al. (2015). Os resultados apontaram a necessidade de melhoria nos sistemas de tratamento de efluentes no Litoral Paulista. A AQRM é uma ferramenta capaz de estimar a probabilidade de infecção no cenário das águas recreacionais e pode auxiliar no gerenciamento dos riscos. / The use of coastal water for recreational purposes has been associated with benefits to health and well-being; however some negative impacts can diminish such benefits. The usages can vary according to the type of activity but the primary contact demands physical contact resulting in a high probability in accidental ingestion of water. Brazilian legislation for coastal recreational waters CONAMA 274/2000 establishes criteria for fecal indicator bacteria and furthermore recommends investigation of pathogenic organisms for beaches which classification is systematically as improper. Given the scarcity of data referring to pathogenic presence in beaches´ waters, CETESB carried out a study, in 2010 and 2012, for quantifying enterovirus, adenovirus, hepatitis A virus, Cryptosporidium sp and Giardia sp in coastal waters of São Paulo state in order to obtain data about their occurrence of these pathogens in coastal waters. The objective of this study was to estimate the annual risk of infection and disease for Giardia sp and Cryptosporidium sp by ingestion of water during primary contact recreation using QMRA approach. Concentrations of both parasites were taken from the annual report entitled Quality of coastal beaches in São Paulo state by CETESB (2011 and 2012). In these years were analyzed 203 samples of water for quantifying (oo)cysts of Giardia and Cryptosporidium from 12 beaches in the first year and five beaches in the second year of research. The samples were collected at one meter isobaths, with monthly frequency. Giardia was the most frequent parasite present in 43 per cent of samples and Cryptosporidium sp in 13 per cent . Exposure scenario was built considering types of activity, beach goers (children, adults and athletes), concentration of parasites, ingestion rate, duration and frequency of exposure. The probability of annual infection was higher in beaches in which there were more positive results for parasites for athletes and for Giardia infection. The tolerable risk for gastroenteritis by USEPA, which is 3.6 per cent , was overpassed in some cases. Though the results found in this study overpassed the cumulative incidence reported by LAMPARELLI et al. (2015). The results indicate the need for improvements in wastewater treatment systems in the coastal area of São Paulo. As QMRA is a tool capable in estimating the probability of infection it can help to highlight crucial issues in risk management.

Introdução - A prática de reúso pela aplicação de esgotos tratados na agricultura atualmente é considerada parte integrante dos recursos hídricos por muitas nações. No entanto, oferece riscos à saúde da população pela presença de bactérias, cistos de protozoários, ovos de helmintos e vírus, capazes de sobreviver por longos períodos em ambientes desfavoráveis e apresentarem um curto tempo entre a infecção e o desenvolvimento da doença. Objetivo - Estabelecer medidas preventivas para o lançamento de efluentes nos ecossistemas aquáticos, controle sanitário na redução de patógenos transmitidos por águas contaminadas e a disposição de efluentes tratados em solos tropicais como ferramentas de auxílio do manejo integrado dos recursos hídricos em bacias hidrográficas, por meio do uso de metodologia de gerenciamento de risco com aplicação do Sistema APPCC, em um conjunto de tecnologias na produção de efluente tratado de esgoto de origem doméstica para avaliar o potencial de emprego em solos agrícolas. Métodos - A pesquisa foi desenvolvida na estação de tratamento de esgoto e no campo experimental para pesquisas de utilização de efluente na agricultura no município de Lins. Os indicadores biológicos estudados e os pontos de amostragem foram determinados através da utilização da metodologia de controle de qualidade Análise de Perigos e Pontos Críticos de Controle (APPCC). Foram coletadas amostras do solo irrigado e dos poços de monitoramento do lençol freático. As amostras foram submetidas a análises físico-químicas, microbiológicas e parasitológicas. Aos resultados obtidos foi aplicada a Avaliação Quantitativa do Risco Microbiológico, para a determinação do risco anual de infecção. Resultados - O efluente final apresentou concentrações médias de 8,13x105 NMP/100 mL de coliformes totais e 4,69x105 NMP/100 mL de Escherichia coli, não sendo observados ovos de helmintos. O solo apresentou maior concentração de coliformes totais e E. coli na camada superficial 1,01x106 e 8,70x103, diminuindo ao longo da profundidade. Os ovos de helmintos foram encontrados entre a superfície e os 15 cm de profundidade em concentrações entre 0,07 e 0,87 ovos/g de peso seco. Foi constatada a presença de adenovírus em concentração de 3,56x105 cópias genômicas/g entre os 5 e 10 cm de profundidade em 2015. Nos poços de monitoramento foram constatadas concentrações de coliformes totais variando entre < 1,00 e 1,01x103 NMP/100 mL e E. coli entre <1,00 e 1,00x100 NMP/100 mL. Não foi observada a presença de vírus entéricos. O risco anual de infecção estimado para E. coli no efluente final foi 1,02x10-2 pppa, no solo variou entre 2,68x10-3 e 7,59x10-3 pppa e nos poços de monitoramento variou entre 1,42x10-8e 4,38x10-9 pppa. Para os ovos de helmintos observados no efluente do tratamento primário o risco anual de infecção calculado foi 4,04x10-2 pppa e no solo variou entre 9,57x10-1 e 9,76x10-1 pppa. Conclusões No período da pesquisa, as amostras dos sistemas de tratamento de esgoto e de irrigação demonstraram atender as expectativas de remoção de patógenos condizentes aos seus parâmetros de projeto, havendo restrições para seu lançamento em corpos hídricos e aplicação na agricultura. O solo mostrou capacidade de retenção dos organismos patogênicos nos primeiros 60 cm de profundidade, reduzindo as suas concentrações a níveis inferiores a 1,00 NMP/100 mL nos aquíferos. / Introduction - Currently, the practice of reuse through the application of treated sewage in agriculture considers an integral part of water resources for many nations. However, threatens the health of the population by the presence of bacteria, protozoan cysts, helminth eggs and viruses able to survive for long periods in harsh environments and present a short time between infection and development of disease. Objective - Establish preventive measures for the release of effluents on aquatic ecosystems, sanitary control in the reduction of pathogens transmitted by contaminated water and the disposal of treated effluent in tropical soils as aid tools in integrated management of water resources in river basins. For this purpose it was employed as risk management methodology the Hazard Analysis and Critical Control Points system (HACCP) in a set of technologies in the treated effluent production of domestic sewage to assess the employment potential in agricultural soils. Methods - The study was conducted in the sewage treatment plant and in an adjoining experimental field situated at Lins city. The biological indicators and the sampling points were determined by using the quality control methodology Hazard Analysis and Critical Control Points (HACCP). Samples of irrigated soil and groundwater monitoring wells were collected. The samples were subjected to analysis, physical-chemical, microbiological and parasitological. The results obtained was applied to Quantitative Microbial Risk Assessment (QRMA), for determining the annual risk of infection. Results - The final effluent presented average concentrations of 8.13x105 MPN / 100 mL of total coliforms and 4.69x105 MPN / 100 mL of Escherichia coli, not being observed helminth eggs. The soil showed the highest concentration of total coliforms and E. coli in the surface layer and 1.01x106 8.70x103, decreasing along the depth. Eggs from helminths were found between the surface and 15 cm depth in concentrations from 0.07 to 0.87 eggs / g dry weight. It was found the presence of adenovirus in concentration 3.56x105 genomic copies / g between 5 and 10 cm depth in 2015. In monitoring wells total coliform concentrations were found ranging from <1.00 and 1.01x103 NMP / 100 mL and E. coli between <1.00 and 1.00x100 MPN / 100 mL. It was not observed the presence of enteric viruses. The estimated annual risk of infection to E. coli in the final effluent was 1.02x10-2 pppy, soil ranged from 2.68x10-3 and 7.59x10-3 pppy and monitoring wells ranged from 1.42x10-8 e 4.38x10-9 pppy. For helminth eggs observed in the effluent from the primary treatment, the annual risk of infection was calculated 4.04x10-2 pppy and soil ranged from 9.57x10-1 and 9.76x10-1 pppy. Conclusions - During the survey period, samples of sewage and irrigation treatment systems showed meet the expectation removal of pathogens consistent to its design parameters, with restrictions on its release in water and applied in agriculture bodies. The soil of pathogenic organisms showed retention capacity in the first 60 cm depth by reducing its concentration to levels below 1.00 MPN / 100 mL in aquifers.

Human excreta contain plant nutrients and have the potentialto be used as a fertiliser in agriculture. Urine contributesthe major proportion of the nutrients (N, P and K) in domesticwastewater whereas faeces contribute a smaller amount andinvolves greater health risks if reused due to the possiblepresence of enteric pathogens. Human urine does not generallycontain pathogens that can be transmitted through theenvironment. Source-separation of urine and faeces is possible by usingurine-separating (or urine-diverting) toilets, available assimple dry toilets or porcelain flush toilets with dividedbowls. The risk for transmission of disease when handling andreusing the urine is largely dependent on thecross-contamination by faeces. In this research, the presenceof human faeces in urine samples was successfully determined byanalysing for faecal sterols. Cross-contamination was evidentin 22% of the samples from urine collection tanks, and in thesequantified to an average (± SD) of 9.1 ± 5.6 mgfaeces per litre urine. Testing for indicator bacteria wasshown to be an unsuitable method for determining faecalcontamination in human urine sinceE. colihad a rapid inactivation in the urine and faecalstreptococci were found to grow within the system. The fate of any enteric pathogens present in urine iscrucial for the risk for transmission of infectious diseases.Gram-negative bacteria (e.g.SalmonellaandE. coli) were rapidly inactivated (time for 90%reduction, T90&lt;5 days) in source-separated urine at itsnatural pH-value of 9. Gram-positive faecal streptococci weremore persistent with a T90of approximately 30 days. Clostridia sporenumbers were not reduced at all during 80 days. Similarly,rhesusrotavirus andSalmonella typhimuriumphage 28B were not inactivated inurine at low temperature (5°C), whereas at 20°C theirT90-values were 35 and 71 days, respectively.Cryptosporidiumoocysts were less persistent with a T90of 29 days at 4°C. Factors that affect thepersistence of microorganisms in source-separated human urineinclude temperature, pH, dilution and presence of ammonia. By using Quantitative Microbial Risk Assessment (QMRA), therisks for bacterial and protozoan infections related tohandling and reuse of urine were calculated to be&lt;10-3for all exposure routes independent of the urinestorage time and temperature evaluated. The risk for viralinfection was higher, calculated at 0.56 for accidentalingestion of 1 ml of unstored urine. If the urine was stored at20°C for 6 months the risk for viral infection was reducedto 5.4 × 10-4. By following recommendations for storage and reuse, whichare dependent on the type of crop to be fertilised, it ispossible to significantly decrease the risk for infections. Sofar, the level of risk that is acceptable is unknown. Theacceptable risk will be one of the main factors determining thefuture utilisation of source-separated human urine inagriculture. <b>Keywords:</b>urine-separation, urine, wastewater systems,wastewater reuse, recycling, enteric pathogens, faecal sterols,indicator bacteria, hygiene risks, microbial persistence,microbial risk assessment, QMRA, fertiliser, crop.