More than 3.5 billion tons of solid wastes--such as abandoned cars, discarded bottles and cans, and paper--accumulate in the United States each year. About $4.5 billion is spent annually to dispose of wastes from these sources. The most common methods of solid waste disposal are landfill and incineration. A survey has shown that 94 percent of landfills used were inadequate because the wastes were not covered daily or were burned in the open, and that 75 percent of the incinerators used were inadequate because they did not reduce waste efficiently or because they caused air pollution. In view of these facts and of the increasing public and congressional concern over solid waste disposal, GAO reviewed the effectiveness of the Federal grant program conducted by the Office of Solid Waste Management Programs for demonstrating new and improved means of solid waste disposal.