Over 10,000 spills occur annually in the United States. They are defined as noncontinuous discharges or dumping which occur as a result of accidents, malfunctions of equipment, human error, deliberate discharges of bilge or ballast water and convenience dumping of hazardous materials and oil into sewers, streams, estuaries, coastal waters, and upon land areas. Approximately 80 percent of the reported spills involve oil, including crude and petroleum products ranging from grease to gasoline and waste lubricating oil. It is estimated that over 30 million gallons of oil were discharged in 1972. The remaining 20 percent involve hazardous polluting substances other than oils, which include poisons, corrosive materials, oxidizing agents, radioactive materials, and other compounds and mixtures which severely affect the aquatic environment.