In process safety, we spend a lot of time discussing the PRIMARY containment systems; however, our secondary containment systems play a vital role in our PROTECTION and MITIGATION layers of protection. Of course, we want to keep the tiger in its cage, but we also need to be prepared for the day it gets loose, and this is where our secondary containment systems come into play. With all that said, let’s talk about verifying the sizing and containment abilities of a “dike.”
I have practiced this since 1994, when my facility built a new tank farm. The environmental team required the contractor to fill the dike with fire water to “leak test” (i.e., proof test) that it did not leak. We held the liquid in the dike for four (4) hours, watching for a drop in the level.
However, the Property Conservation Manager required them to run the water through a flow meter so we could calculate the amount of water the dike would hold, AND we could verify fire water flows from the new hydrant branch on the fire water system.
So essentially, we are capturing three (3) pieces of data to validate our:
- Dike Sizing,
- Dike is Leak Proof, and
- Fire-Water Flows
during a single test.
Some will argue this is NOT a PSM or a Code requirement. That matters not to me, as anything we claim as a “safeguard” in our PREVENT—PROTECT—MITIGATE model has to be verified and validated that it is designed, constructed, operated, and maintained per our chosen RAGAGEP.