Various types and quantities of oil products are stored in ASTs and USTs throughout the facility to support building, vehicle, and aircraft maintenance and operations. The storage of large quantities of hazardous liquids poses safety risks to personnel as well as environmental risks from unauthorized releases or spills. AST and UST regulations are designed to minimize the threat of an unauthorized or accidental release.
For all containers storing petroleum, oils and other lubricants that are 55 gallons or greater, secondary containment for that container is required. Secondary containment should be able to capture 100% of the contents of the largest container plus 10% capacity for precipitation rainwater. Make sure that all secondary containment areas are free of liquids and that any liquids present are pumped out within 24 hours of accumulation.