Water resources are sources of water that are useful or potentially useful to humans. They are important because they are needed for life to exist. Many uses of water include agricultural, industrial, household, recreational and environmental activities. Virtually all of these human uses require fresh water. Only 2.7% of water on the Earth is fresh water, and over two thirds of this is frozen in glaciers and polar ice caps, leaving only 0.007% available for human use. Fresh water is a renewable resource, yet the world's supply of clean, fresh water is steadily decreasing. Water demand already exceeds supply in many parts of the world, and as world population continues to rise at an unprecedented rate, many more areas are expected to experience this imbalance in the near future. The framework for allocating water resources to water users (where such a framework exists) is known as water rights. This new book presents recent and important research in the field.

In order to confront the increasingly severe water problems faced by all parts of the country, the United States needs to make a new commitment to research on water resources. A new mechanism is needed to coordinate water research currently fragmented among nearly 20 federal agencies. Given the competition for water among farmers, communities, aquatic ecosystems and other users-as well as emerging challenges such as climate change and the threat of waterborne diseases-Confronting the Nation's Water Problems concludes that an additional $70 million in federal funding should go annually to water research. Funding should go specifically to the areas of water demand and use, water supply augmentation, and other institutional research topics. The book notes that overall federal funding for water research has been stagnant in real terms for the past 30 years and that the portion dedicated to research on water use and social science topics has declined considerably.

Regulatory standards are already on the books at the the U.S. Environmental Protection Agency (EPA) to address health risks posed by inhaling tiny particles from smoke, vehicle exhaust, and other sources. At the same time, Congress and EPA have initiated a multimillion dollar research effort to better understand the sources of these airborne particles, the levels of exposure to people, and the ways that these particles cause damage. To provide independent guidance to the EPA, Congress asked the National Research Council to study the relevant issues. The result is a series of four reports on the particulate-matter research program. The first two books offered a conceptual framework for a national research program, identified the 10 most critical research needs, and described the recommended timing and estimated costs of such research. This, the third volume, begins the task of assessing the progress made in implementing the research program. The National Research Council ultimately concludes that the ongoing program is appropriately addressing many of the key uncertainties. However, it also identifies a number of critical specific subjects that should be given greater attention. Research Priorities for Airborne Particulate Matter focuses on the most current and planned research projects with an eye toward the fourth and final report, which will contain an updated assessment.

Slow sand filtration is typically cited as being the first "engineered" process in drinking-water treatment. Proven modifications to the conventional slow sand filtration process, the awareness of induced biological activity in riverbank filtration systems, and the growth of oxidant-induced biological removals in more rapid-rate filters (e.g. biological activated carbon) demonstrate the renaissance of biofiltration as a treatment process that remains viable for both small, rural communities and major cities. Biofiltration is expected to become even more common in the future as efforts intensify to decrease the presence of disease-causing microorganisms and disinfection by-products in drinking water, to minimize microbial regrowth potential in distribution systems, and where operator skill levels are emphasized. Recent Progress in Slow Sand and Alternative Biofiltration Processes provides a state-of-the-art assessment on a variety of biofiltration systems from studies conducted around the world. The authors collectively represent a perspective from 23 countries and include academics, biofiltration system users, designers, and manufacturers. It provides an up-to-date perspective on the physical, chemical, biological, and operational factors affecting the performance of slow sand filtration (SSF), riverbank filtration (RBF), soil-aquifer treatment (SAT), and biological activated carbon (BAC) processes. The main themes are: comparable overviews of biofiltration systems; slow sand filtration process behavior, treatment performance and process developments; and alternative biofiltration process behaviors, treatment performances, and process developments.

This book offers a comprehensive framework of the current state of water resources in Italy and of the main stages of the evolutionary way in the last decades for achieving an integrated, sustainable and equitable water resources management. The main paradigms of water resources development are identified as: i) engineering and economic approach to water resources exploitation, ii) focus on pollution control and water-excess management, iii) a comprehensive approach toward a sustainable and equitable distribution of resources and effective risk reduction of water-related disasters. After a section devoted to the analysis of some historic stages in the legislation framework and the governance of water and soil, with particular reference to planning, design, building and operation of water systems, two sections deal with the estimation of water resources availability on national territory and estimation of water demands in municipal, agricultural, industrial, ecosystem sectors. The complex problems that the Italian society has to solve in the water field and the main challenges of a changing world are discussed in the fourth section of the volume. The book will not only be useful for water professionals, but also for citizen who like to discern the key factors which delay the recognition of water as a resource for life. The description of the problems and adopted solutions could also serve as a guideline for similar situations encountered in other countries, improving the preparation of the responsible people.