The disposal of waste products by man has led to the contamination of soil and ground-water. Problems associated with the disposal of hazardous waste are of major concern. Using the U.S. Environmental Protection Agency's definition of hazardous waste, the contamination of soils and groundwater resulting from waste disposal is viewed from two standpoints: (1) disposal of waste so that contamination does not occur; and (2) problems and solutions to situations where the soil or groundwater has already been contaminated. Six approaches to safe disposal are considered: (1) secure hazardous waste landfills; (2) co-disposal of hazardous and municipal waste; (3) land spreading; (4) deep-well disposal; (5) underground mine waste; and (6) alternatives to land disposal. Options for decontaminating soil and groundwater are discussed, in case the research needs in the 1980's are identified.