In many parts of the developing world, drinking water is collected from unsafe surface sources outside the home and is then held in household storage vessels. Drinking water may be contaminated at the source or during storage; strategies to reduce waterborne disease transmission must safeguard against both events. We describe a two-component prevention strategy, which allows an individual to disinfect drinking water immediately after collection (point-of-use disinfection) and then to store the water in narrow-mouthed, closed vessels designed to prevent recontamination (safe storage). New disinfectant generators and better storage vessel designs make this strategy practical and inexpensive. This approach empowers households and communities that lack potable water to protect themselves against a variety of waterborne pathogens and has the potential to decrease the incidence of waterborne diarrheal disease.

Wastewater disposal by marine outfalls is proven and effective and is a reliable and cost effective solution with minimal environmental impacts. The design and siting of submarine outfalls is a complex task that relies on many disciplines including oceanography, civil and environmental engineering, marine biology, construction, economics, and public relations. Marine Wastewater Outfalls and Treatment Systems brings these disciplines together and outlines all tasks involved in the planning and design of a wastewater system involving a marine outfall. This book concerns the design of marine wastewater disposal systems: that is an ocean outfall plus treatment plant. All aspects of outfall design and planning are covered, including water quality design criteria, mathematical modelling of water quality and dilution, gathering required oceanographic data, appropriate wastewater treatment for marine discharges, construction materials for marine pipelines, forces on pipelines and outfall design, outfall hydraulics, outfall construction, tunnelled outfalls, operation and maintenance, monitoring, case studies are discussed and methods for gaining public acceptance for the project are presented. Finally, costs for many outfalls around the world are summarized and methods for estimating costs are given. This is the first book to consider all aspects of marine outfall planning and construction. The authors are all extensively involved with outfall schemes and aware of recent developments. The science and technology of all aspects of outfall discharges into coastal waters and estuaries of treated municipal or industrial wastewater has advanced considerably over the past few years. Marine Wastewater Outfalls and Treatment Systems provides an up to date and comprehensive summary of this rapidly developing area.

A very large segment of the world's population is without a microbiologically safe water supply. It is estimated that in Latin America more than 40% of the population is utilizing water of dubious quality for human consumption. This figure is probably even higher in Africa and areas of southeast Asia. Water used for drinking and food preparation can be an important route of transmission for many of the most widespread and debilitating of the diseases that afflict humans. The cholera pandemic which struck Latin America in January 1991, and has become endemic in many of the countries, continues to exemplify the public health significance of contaminated drinking water. Ideally, this neglected segment of the world's population should be served with piped water systems that provide a continuous supply of microbiologically safe water, but this would require such enormous investments of financial and human resources that it is not reasonable to expect that it will be accomplished. Interim practical measures to assure microbiologically safe water are necessary. The public health intervention to accomplish this is described in this paper and has an annual per family cost of which ranges between $1.50 and $4. It consists of providing individual households with one or preferably two suitable water containers in which to disinfect and store the essential quantities of water that need to be free of pathogens, with the containers of a design that will preclude recontamination of the contents and enable the production and distribution of the water disinfectants to be managed at the local level. It includes the necessary component of public education, promotion and involvement to establish the sustainability of the measures as a community-based endeavor. Investigation and demonstration projects are being carried out in II countries to determine and perfect and appropriate intervention, and it has been proven that it is economically, technically and socially feasible to assure microbiologically safe water for the world's population that is threatened by waterborne diseases. Carefully controlled microbiological analysis of the untreated and treated water shows that waterborne pathogens can be destroyed or inactivated, and carefully controlled epidemiological studies being carried out by the Centers for Disease Control and Prevention show that this intervention achieves considerable reduction in the incidence of water borne disease. It is recommended that all developing countries initiate programs to replicate the health measure described in this paper in order to test its validity and to adapt it to their local conditions.

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