On October 11, 2000, a breakthrough of Martin County Coal Corporation's coal waste impoundment released 250 million gallons of slurry in near Inez, Kentucky. The 72-acre surface impoundment for coal processing waste materials broke through into a nearby underground coal mine. Although the spill caused no loss of human life, environmental damage was significant, and local water supplies were disrupted. This incident prompted Congress to request the National Research Council to examine ways to reduce the potential for similar accidents in the future. This book covers the engineering practices and standards for coal waste impoundments and ways to evaluate, improve, and monitor them; the accuracy of mine maps and ways to improve surveying and mapping of mines; and alternative technologies for coal slurry disposal and utilization. The book contains advice for multiple audiences, including the Mine Safety and Health Administration, the Office of Surface Mining, and other federal agencies; state and local policymakers and regulators; the coal industry and its consultants; and scientists and engineers.

Coal will continue to provide a major portion of energy requirements in the United States for at least the next several decades. It is imperative that accurate information describing the amount, location, and quality of the coal resources and reserves be available to fulfill energy needs. It is also important that the United States extract its coal resources efficiently, safely, and in an environmentally responsible manner. A renewed focus on federal support for coal-related research, coordinated across agencies and with the active participation of the states and industrial sector, is a critical element for each of these requirements. Coal focuses on the research and development needs and priorities in the areas of coal resource and reserve assessments, coal mining and processing, transportation of coal and coal products, and coal utilization.

Since the Arab oil embargo of 1974, it has been clear that the days of almost limitless quantities of low-cost energy have passed. In addition, ever worsening pollution due to fossil fuel consumption, for instance oil and chemical spills, strip mining, sulphur emission and accumulation of solid wastes, has, among other things, led to an increase of as much as 10% in the carbon dioxide content of the atmosphere in this century. This has induced a warming trend through the 'greenhouse effect' which prevents infrared radiation from leaving it. Many people think the average planetary temperatures may rise by 4°C or so by 2050. This is probably true since Antarctic ice cores evidence indicates that, over the last 160000 years, ice ages coincided with reduced levels of carbon dioxide and warmer interglacial episodes with increased levels of the gas in the atmosphere. Consequently, such an elevation of temperature over such a relatively short span of time would have catastrophic results in terms of rising sea level and associated flooding of vast tracts of low-lying lands. Reducing the burning of fossil fuels makes sense on both economic and environmental grounds. One of the most attractive alternatives is geothermal resources, especially in developing countries, for instance in El Salvador where geothermal energy provides about a fifth of total installed electrical power already. In fact, by the middle 1980s, at least 121 geothermal power plants were operating worldwide, most being of the dry steam type.