Secondary Containment Systems for Tanks

Secondary containment systems must also be in place for tanks that are holding hazardous waste. These systems must be designed, installed, and operated in a way that prevents the transfer of wastes from the tank into the surrounding soil or sources of water. Examples of secondary containment systems for tanks include the following:

• An impermeable external liner that surrounds the tank
• An underground vault (usually built with concrete floors and walls and an impermeable cover)
• A double-walled tank with a leak detection monitoring system installed between the walls

Any pipes, tubes, joints, and valves that are part of the storage system must also have a secondary containment system. Examples of containment systems for ancillary equipment include the following:

• Lined trenches
• Jacketed or double-walled piping

Exemptions: The following equipment is exempt from the requirement for secondary containment, as long as the equipment is inspected daily:

• Above-ground piping (except for flanges, joints, valves, and connections, which do need secondary containment)
• Welded flanges, welded joints, and welded connections
• Seal-less or magnetic coupling pumps
• Above-ground pressurized piping systems with automatic shut-off devices

To learn more about RCRA visit our RCRA Hazardous Waste Safety Online Training web page.