What is Secondary Containment?
If your company stores hazardous materials or hazardous wastes, you need secondary containment systems that meet Environmental Protection Agency (EPA) or Occupational Safety and Health Administration (OSHA) regulations.
Q: What is secondary containment?
A: Broadly, secondary containment is a backup system that prevents spills or leakage from a primary container from spreading onto land or into a waterway. Examples of portable primary containers include drums, pails, and intermediate bulk containers (IBCs), tank trucks and railcars. EPA Container Storage Regulation 40 CFR 264.175, and Spill Prevention, Control and Countermeasures (SPCC) Rule 40 CFR 112 apply. Local governments may have other rules and restrictions, so be sure to check in with them.
Q: What’s a hazardous material?
A: Even though OSHA and EPA broadly define hazardous materials, any materials or liquids that harm people, plants, animals or the environment should be considered as hazardous. Check the EPA and OSHA rules as well as your state and county regulations for guidance about your specific materials.
Q: I only store small containers. Do all these rules apply to me?
A: Secondary containment is required for containers 55 gallon and larger, or if multiple containers exceed a total of 1,000 gallons. Still, it’s better to contain a potential leak or spill - even a small one - rather than scrambling to prevent it from reaching a floor drain.
Q: What’s the difference between spill control and secondary containment?
A: Spill control is reactive in an emergency and uses portable equipment and supplies to control the spread of a leak or spill. For example, when a worker is transporting a filled drum and it tips and spills, or it becomes damaged and leaks. Secondary containment is preventative - designed to safely and completely contain an accidental leak or spill from a primary container in storage, minimizing the need for an emergency spill control response.
Q: What does secondary containment look like?
A: The exact equipment you need depends on what quantity and types of primary containers you store. Three basics are: Compatible, Impermeable, Durable.
The system could include permanent basins, berms with liners, or spill pallets and decks typically made from various plastic materials, which offer a wide range of chemical compatibility and are generally resistant to cracks caused by mechanical and thermal shocks.
Primary containers cannot sit in spilled or leaked liquid, so your secondary containment system must be designed to drain away any spills or leaks, using a grate over a drainable sump, such as the one at right.
You must not let your system overflow, so it must have provision for removing accumulated liquid in a timely manner without getting it on the ground, through a drain plug or pump.
EPA regulations require the containment device to have a capacity of 110% of the container, or the total volume of the largest container, whichever is greater, that will be stored on it.
For example, since an IBC typically contains 275 gallons, the secondary containment basin for a single IBC must have a capacity of at least 302.5 gallons. Even if a leaking container empties completely, its entire contents will be retained and may even be reclaimed.
If the secondary containment will be located outside, the capacity must allow for anticipated rain or snow accumulation. That’s why it’s much better to use an enclosed system to keep the weather out.
Q: Are there different secondary containment rules for flammables?
A: EPA doesn’t regulate flammables differently for the purpose of secondary containment. However, secondary containment systems for flammables need to be fire-resistant, and OSHA and National Fire Protection Association (NFPA) have strict rules for storage of flammables. More than 25 gallons of flammables must be stored in an approved safety cabinet, many which also provide secondary containment that meets EPA requirements.
Q: Is outside storage better for hazardous materials?
A: Space, safety, and temperature extremes are important considerations. Any materials suitable for outside storage must be protected from the elements and outdoor secondary containment systems, with their large sumps, will collect rain and snow. Therefore, it should be securely covered and protected from tampering.
