Erosion and equipment tend to destroy the integrity of earthen berms. If the site is shut down, the berm will need to be removed and disposed of at a proper disposal area. All these factors are costly. Another approach, has been the use of concrete walls for Secondary Containment. This too, is costly, and over time concrete will develop cracks requireing maintanence.
Concrete walls give a special problem in the event the site is closed down.
You now have a major project in breaking up the concrete and disposing of it. Steel Containment Rings are economical, are easy to install, are low maintanence and can be unbolted and removed from the site. They can then be reassembled with a minimum of cost at another location. Each ring comes complete with a set of installation manuals.