Paper: Oil and Hazardous Materials Program of the United States Environmental Protection Agency

Spills of oil and hazardous substances are one of the primary concerns of EPA. Presently, an estimated 15,000 spills of oil and hazardous substances occur annually in the navigable waters of the United States. These spills are expected to significantly increase over the next 30 years, if left unchecked, as a result of greater production, transport, storage and transfer. It is estimated, based on existing reporting functions, that of the 15,000 total spills, approximately 75 percent involve petroleum products. These include the large and devastating-type spills such as the Santa Barbara offshore oil well blowout, the Louisiana offshore oil well platform blowouts and fires, and the large tanker and barge collisions and groundings. Added to these large incidents, there are numerous lesser events affecting practically every body of water where oil transport, transfer, pipeline crossing, onshore storage or related activities take place. In addition to spills or accidental discharges of oil and hazardous substances, large quantities of these pollutants enter the water environment every day as a result of continuous effluent discharges from refineries, chemical and petrochemical plants, factories, etc. These continuous discharges may have a more detrimental long-term effect than the large, one-time accidental spills.