The objective of this project is to understand the potential mechanisms of antimicrobial resistance of E. coli and opportunistic pathogens under disinfection conditions. The project involves molecular techniques to understand genetic changes in biofilm and suspended bacteria in response to different disinfectant conditions. It examines the effects of using single chemical disinfectants (free chlorine, chloramines, and chlorine dioxide) compared with UV light pretreatment, as well as the impact of pipe material (polycarbonate or cast iron) and E. coli mutations. Field studies include both surface water and groundwater.
With an increasing population, use of new and diverse chemicals that can enter the water supply, and emergence of new microbial pathogens, the U.S. federal government is faced with a regulatory dilemma: Where should it focus its attention and limited resources to ensure safe drinking water supplies for the future? Identifying Future Drinking Water Contaminants is based on a 1998 workshop on emerging drinking water contaminants. It includes a dozen papers that were presented on new and emerging microbiological and chemical drinking water contaminants, associated analytical and water treatment methods for their detection and removal, and existing and proposed environmental databases to assist in their proactive identification and regulation. The papers are preceded by a conceptual approach and related recommendations to EPA for the periodic creation of future Drinking Water Contaminant Candidate Lists (CCLsâ€"produced every five yearsâ€"include currently unregulated chemical and microbiological substances that are known or anticipated to occur in public water systems and that may pose health risks).
Protecting and maintaining water distributions systems is crucial to ensuring high quality drinking water. Distribution systems-consisting of pipes, pumps, valves, storage tanks, reservoirs, meters, fittings, and other hydraulic appurtenances-carry drinking water from a centralized treatment plant or well supplies to consumers' taps. Spanning almost 1 million miles in the United States, distribution systems represent the vast majority of physical infrastructure for water supplies, and thus constitute the primary management challenge from both an operational and public health standpoint. Recent data on waterborne disease outbreaks suggest that distribution systems remain a source of contamination that has yet to be fully addressed. This report evaluates approaches for risk characterization and recent data, and it identifies a variety of strategies that could be considered to reduce the risks posed by water-quality deteriorating events in distribution systems. Particular attention is given to backflow events via cross connections, the potential for contamination of the distribution system during construction and repair activities, maintenance of storage facilities, and the role of premise plumbing in public health risk. The report also identifies advances in detection, monitoring and modeling, analytical methods, and research and development opportunities that will enable the water supply industry to further reduce risks associated with drinking water distribution systems.
Heterotrophic Plate Counts and Drinking-water Safety provides a critical assessment of the role of the Heterotrophic Plate Count (HPC) measurement in drinking water quality management. It was developed from an Expert workshop of 32 scientists convened by the World Health Organization and the WHO/NSF International Collaborating Centre for Drinking Water Safety and Treatment in Geneva, Switzerland. Heterotrophs are organisms, including bacteria, yeasts and moulds, that require an external source of organic carbon for growth. The HPC test (or Standard Plate Count), applied in many variants, is the internationally accepted test for measuring the hetrotrophic microorganism population in drinking water, and also other media. It measures only a fraction of the microorganisms actually present and does not distinguish between pathogens and non-pathogens. High levels of microbial growth can affect the taste and odor of drinking water and may indicate the presence of nutrients and biofilms which could harbor pathogens, as well as the possibility that some event has interfered with the normal production of the drinking water. HPC counts also routinely increase in water that has been treated by an in-line device such as a carbon filter or softener, in water-dispensing devices and in bottled waters and indeed in all water that has suitable nutrients, does not have a residual disinfectant, and is kept under sufficient conditions. There is debate among health professionals as to the need, utility or quantitative basis for health-based standards or guidelines relating to HPC-measured regrowth in drinking water. The issues that were addressed in this work include: the relationship between HPC in drinking water (including that derived from in-line treatment systems, dispensers and bottled water) and health risks for the general public the role of HPC as an indirect indicator or index for pathogens of concern in drinking water the role of HPC in assessing the efficacy and proper functioning of water treatment and supply processes the relationship between HPC and the aesthetic acceptability of drinking water. Heterotrophic Plate Counts and Drinking-water Safety provides valuable information on the utility and the limitations of HPC data in the management and operation of piped water systems as well as other means of providing drinking water to the public. It is of particular value to piped public water suppliers and bottled water suppliers, manufacturers and users of water treatment and transmission equipment and inline treatment devices, water engineers, sanitary and clinical microbiologists, and national and local public health officials and regulators of drinking water quality.
Improved housing conditions can save lives, prevent disease, increase quality of life, reduce poverty, and help mitigate climate change. Housing is becoming increasingly important to health in light of urban growth, ageing populations and climate change. The WHO Housing and health guidelines bring together the most recent evidence to provide practical recommendations to reduce the health burden due to unsafe and substandard housing. Based on newly commissioned systematic reviews, the guidelines provide recommendations relevant to inadequate living space (crowding), low and high indoor temperatures, injury hazards in the home, and accessibility of housing for people with functional impairments. In addition, the guidelines identify and summarize existing WHO guidelines and recommendations related to housing, with respect to water quality, air quality, neighbourhood noise, asbestos, lead, tobacco smoke and radon. The guidelines take a comprehensive, intersectoral perspective on the issue of housing and health and highlight co-benefits of interventions addressing several risk factors at the same time. The WHO Housing and health guidelines aim at informing housing policies and regulations at the national, regional and local level and are further relevant in the daily activities of implementing actors who are directly involved in the construction, maintenance and demolition of housing in ways that influence human health and safety. The guidelines therefore emphasize the importance of collaboration between the health and other sectors and joint efforts across all government levels to promote healthy housing. The guidelines' implementation at country-level will in particular contribute to the achievement of the Sustainable Development Goals on health (SDG 3) and sustainable cities (SDG 11). WHO will support Member States in adapting the guidelines to national contexts and priorities to ensure safe and healthy housing for all.
"Access to safe water is a fundamental human need and therefore a basic human right" --Kofi Annan, United Nations Secretary General Edited by two world-renowned scientists in the field, The Handbook of Water and Wastewater Microbiology provides a definitive and comprehensive coverage of water and wastewater microbiology. With contributions from experts from around the world, this book gives a global perspective on the important issues faced in the provision of safe drinking water, the problems of dealing with aquatic pollution and the processes involved in wastewater management. Starting with an introductory chapter of basic microbiological principles, The Handbook of Water and Wastewater Microbiology develops these principles further, ensuring that this is the essential text for process engineers with little microbiological experience and specialist microbiologists alike. Comprehensive selection of reviews dealing with drinking water and aquatic pollution Provides an understading of basic microbiology and how it is applied to engineering process solutions Suitable for all levels of knowledge in microbiology -from those with no background to specialists who require the depth of information
The microbiology of drinking water remains an important worldwide concern despite modem progress in science and engineering. Countries that are more technologically advanced have experienced a significant reduction in water borne morbidity within the last 100 years: This reduction has been achieved through the application of effective technologies for the treatment, disinfec tion, and distribution of potable water. However, morbidity resulting from the ingestion of contaminated water persists globally, and the available ep idemiological evidence (Waterborne Diseases in the United States, G. F. Craun, ed. , 1986, CRC Press) demonstrates a dramatic increase in the number of waterborne outbreaks and individual cases within the United States since the mid-1960s. In addition, it should also be noted that the incidence of water borne outbreaks of unknown etiology and those caused by "new" pathogens, such as Campylobaeter sp. , is also increasing in the United States. Although it might be debated whether these increases are real or an artifact resulting from more efficient reporting, it is clear that waterborne morbidity cannot be ignored in the industrialized world. More significantly, it represents one of the most important causes of illness within developing countries. Approxi mately one-half the world's population experiences diseases that are the direct consequence of drinking polluted water. Such illnesses are the primary cause of infant mortality in many Third World countries.
Updated throughout for this new edition, Water Distribution System Monitoring describes the latest water quality monitoring approaches, techniques, and equipment that will assist water utilities for compliance with the "Lead and Copper Rule" as well as address numerous other water quality issues. Water quality data are obtained using the appro
Hidden problems, buried deep in the pipe networks of water distribution systems, are very serious potential threats to water quality. Microbial Quality of Water Supply in Distribution Systems outlines the processes and issues related to the degradation of water quality upon passage through networks of pipes, storage reservoirs, and standpipes on its way to the consumer. The risks associated with biofilm accumulation, bacteria, and other contaminants are discussed in great detail. In addition to its excellent microbiological coverage of organisms in drinking water and biofilms in distribution systems, Microbial Quality of Water Supply in Distribution Systems provides clear treatments of the technical and public communication issues most commonly affecting the quality of water and water supply systems. The inclusion of numerous case histories in this new book makes it a complete reference source for anyone concerned with water quality and water distribution systems.
