Let's take oil and fuel as an example to better understand the principle of "Containment". Wether it says Oil/fuel you can easily replace with gas, chemicals, water or a combination. 


Oil and fuel may run today’s modern world, but they can also be hazardous materials. Even small amounts that spill and leak out of their intended storage areas end up damaging the environment and creating health risks for people. Containment is simply the practice of keeping all that valuable oil and fuel where it’s needed the most. This breaks down into primary and secondary containment, but it’s the secondary stage that most people are referring to with the general term of containment. Discover why it’s essential to plan for containment from the beginning and not just consider it after a leak or spill.


Primary and Secondary Containment

Containment refers to all of the methods used to keep a material in a specific place. This can cause confusion when discussing oil and fuel storage. Primary containment measures are the containers used to store and transport the liquids themselves. Whether it’s a 55-gallon drum, or a massive holding tank with a capacity in the millions of gallons, it’s a primary containment unit.


Secondary containment measures are all the other efforts used to control spills or leaks from the primary containers. Secondary containment measures can include:

  • Berms, dikes, and bund walls built to hold back liquids and form a basin
  • Liners to ensure that basins don’t leak or seep while containing a spill
  • Gutters, ditches, and culverts that divert the runoff and spills to another holding area
  • Covered or open retention ponds, which can cross over in many ways with walled containment basins
  • Temporary and emergency measures like flexible rubber barriers and absorbent materials
  • Floating booms for spills that occur in or near water.




Primary contained oil  Oil to be secondairy contained

Oil Fields and Beyond

Almost every part of the oil and fuel production line requires containment. The need for spill protection begins at the oil field, but it doesn’t end there. Oil and fuel fields are particularly challenging to properly protect with secondary containment because of their size and dispersed design. Once the crude materials are extracted from the ground, they need spill protection during transport and then secondary containment as they’re transferred to other containers. This is another opportunity for using lined basins to make clean up easy. Demand for secondary containment continues through the processing and refinement stages as well, especially in facilities where spills put workers at risk. Finally, the finished oil and fuel products need secondary containment in their final storage places until they’re used up or disposed of for good. Every storage or transfer location will need some kind of secondary containment, and emergency spill protection devices don’t replace the need for permanent basins and lined walls.


Passive and Active Leak Control

Most secondary containment measures can be considered passive because they’re designed to hold back or absorb spilled oil and fuel. For more active control measures, some oil field and refinery owners install sensors, pumps, and other pieces of advanced equipment. This isn’t mandated by most federal and state laws regarding environmental protection, but it may be required by the Occupational Safety and Health Administration (OSHA) regulations in some environments. At the very least, active sensors that alert operators to the earliest signs of leaks should be included in as many passive secondary containment systems as possible.

Proximity and Access to Waterways

Oil rigs, and other facilities located in and near the water, are particularly prone to environmental damage when they leak. Yet, they’re also the most challenging to secure with secondary containment due to their design and the surrounding open water. Secondary containment regulations are even stricter in most states for oil and fuel facilities that are particularly close to water. Since oil and fuel spread rapidly once they’re released in an open body of water, it’s essential to keep the fluids from reaching the surface if possible. Yet, these facilities must also keep response kits on hand like floating booms and chemical dispersants to quickly deal with any spills that do reach the water.


Comparing the Main Methods of Secondary Containment

With so many methods of secondary containment to choose from, it’s not always easy to determine what’s necessary and recommended. This leads to both oversized and undersized containment, leaving the facility either at risk for leaks or spending too much on protection. Flexible liners are the most versatile way of building permanent secondary containment, but only if an oil and fuel resistant polymer is used. Yet, a liner alone won’t necessarily hold back the correct volume of liquid for a large facility like an entire oil field. Bunding, dikes, and berms are generally combined with the liner to create a basin with the necessary volume.

The EPA has extensive regulations and rules on secondary containment for oil and fuel fields, but they also make exemptions for common scenarios. Don’t rush to overbuild containment that offers little extra protection when it’s possible to perfectly tailor the system to the volume and type of fuel being stored.