Aboveground storage tanks (ASTs) are tanks or other containers that are above ground, partially buried, bunkered, or in a subterranean vault.
The majority of ASTs store petroleum products such as motor fuels, petroleum solvents, heating oil lubricants, and used oil. Oil storage facilities with ASTs are typically found in refineries, and fuel distribution centers. ASTs may also be found in airports, school bus barns, hospitals, automotive repair shops, military bases, farms, and industrial plants. Discharges of chemicals, petroleum, or nonpetroleum oils from storage tanks can contaminate source water. Product spilled, leaked, or lost from storage tanks may accumulate in soils and infiltrate into ground water or be carried away in stormwater runoff to surface water.