https://www.sswm.info/sites/default/files/reference_attachments/PETER%20VARBANETS%20et%20al%202009%20Decentralized%20Systems%20for%20Potable%20Water%20and%20the%20Potential%20of%20Membrane%20Technology.pdf

Decentralized systems for potable water and the potential of membrane technology.

Background: Pit latrines are one of the most common human excreta disposal systems in low-income countries, and their use is on the rise as countries aim to meet the sanitation-related target of the Millennium Development Goals. There is concern, however, that discharges of chemical and microbial contaminants from pit latrines to groundwater may negatively affect human health.

Objectives: Our goals were to a) calculate global pit latrine coverage, b) systematically review empirical studies of the impacts of pit latrines on groundwater quality, c) evaluate latrine siting standards, and d) identify knowledge gaps regarding the potential for and consequences of groundwater contamination by latrines.

Methods: We used existing survey and population data to calculate global pit latrine coverage. We reviewed the scientific literature on the occurrence of contaminants originating from pit latrines and considered the factors affecting transport of these contaminants. Data were extracted from peer-reviewed articles, books, and reports identified using Web of ScienceSM, PubMed, Google, and document reference lists.

Discussion: We estimated that approximately 1.77 billion people use pit latrines as their primary means of sanitation. Studies of pit latrines and groundwater are limited and have generally focused on only a few indicator contaminants. Although groundwater contamination is frequently observed downstream of latrines, contaminant transport distances, recommendations based on empirical studies, and siting guidelines are variable and not well aligned with one another.

Conclusions: In order to improve environmental and human health, future research should examine a larger set of contextual variables, improve measurement approaches, and develop better criteria for siting pit latrines.

/pdf/pit-latrines-and-their-impacts-on-groundwater-quality-a-1iqx0a6iw4.pdf

Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review

Removal of fluoride and uranium by nanofiltration and reverse osmosis: A review

Human enteric viruses can be present in untreated and inadequately treated drinking water. Molecular methods, such as the reverse transcriptase PCR (RT-PCR), can detect viral genomes in a few hours, but they cannot distinguish between infectious and noninfectious viruses. Since only infectious viruses are a public health concern, methods that not only are rapid but also provide information on the infectivity of viruses are of interest. The intercalating dye propidium monoazide (PMA) has been used for distinguishing between viable and nonviable bacteria with DNA genomes, but it has not been used to distinguish between infectious and noninfectious enteric viruses with RNA genomes. In this study, PMA in conjunction with RT-PCR (PMA-RT-PCR) was used to determine the infectivity of enteric RNA viruses in water. Coxsackievirus, poliovirus, echovirus, and Norwalk virus were rendered noninfectious or inactivated by treatment with heat (72°C, 37°C, and 19°C) or hypochlorite. Infectious or native and noninfectious or inactivated viruses were treated with PMA. This was followed by RNA extraction and RT-PCR or quantitative RT-PCR (qRT-PCR) analysis. The PMA-RT-PCR results indicated that PMA treatment did not interfere with detection of infectious or native viruses but prevented detection of noninfectious or inactivated viruses that were rendered noninfectious or inactivated by treatment at 72°C and 37°C and by hypochlorite treatment. However, PMA-RT-PCR was unable to prevent detection of enteroviruses that were rendered noninfectious by treatment at 19°C. After PMA treatment poliovirus that was rendered noninfectious by treatment at 37°C was undetectable by qRT-PCR, but PMA treatment did not affect detection of Norwalk virus. PMA-RT-PCR was also shown to be effective for detecting infectious poliovirus in the presence of noninfectious virus and in an environmental matrix. We concluded that PMA can be used to differentiate between potentially infectious and noninfectious viruses under the conditions defined above.

Use of propidium monoazide in reverse transcriptase PCR to distinguish between infectious and noninfectious enteric viruses in water samples.

Sustainable in situ remediation of recalcitrant organic pollutants in groundwater with controlled release materials: A review

Protecting drinking-water resources is the first barrier against pathogens and substances hazardous to health. Practitioners in drinking-water supply or surveillance - from the local and technical level up to senior management - have a key role in initiating collaboration with other sectors, such as environment, land-use planning, or agriculture towards safeguarding drinking-water sources. Protecting Groundwater for Health provides a structured approach to analysing hazards to groundwater quality, assessing the risk they may cause for a specific supply, setting priorities in addressing these, and developing management strategies for their control. For health professionals, it thus is a tool for access to environmental information needed for such a process, and for professionals from other sectors, it gives a point of entry for understanding health aspects of groundwater management. This book presents tools for developing strategies to protect groundwater for health by managing the quality of drinking-water sources. Section I covers the natural science background needed to understand which pathogens and chemicals are relevant to human health, how they are transported in the sub-surface and how they may be reduced, removed or retarded. Section II provides guidance for compiling information needed to characterise the drinking-water catchment area in order to assess health hazards potentially reaching groundwater. Section III provides conceptional guidance on prioritising both hazards and management responses. Section IV provides an overview of the potential management actions that may be taken to protect drinking-water sources. These begin with their integration into a comprehensive Water Safety Plan that covers all supply steps from catchment to consumer. Section V provides an overview of measures to prevent pollution from human activities in the catchment, beginning with the overarching issues of policy, land-use planning and implementation for protecting groundwater. Overviews are presented of the specific management approaches that help avoid groundwater pollution from the range of human activities in the catchment, i.e. agriculture, sanitation practices, industry, mining, military sites, waste disposal and traffic.

John Chilton

Papers

Protecting Groundwater for Health: Managing the Quality of Drinking-water Sources

Protecting groundwater for health: managing the quality of drinking-water sources.