When do you need secondary containment measures, you ask? Well, some of it is common sense. If you have fuel tanks or other oil filled equipment that leaks steadily and you find your soil, water, or sensitive materials in danger of contamination, then yeah, it's probably a good idea to employ a spill pallet, spill berms, or some other secondary containment measures.
But there are also some less obvious rules of thumb that you can use to ensure the safety of your work site as well as keeping your operation compliant with the myriad regulations set forth by the EPA. Here are some quick little examples below.
Run-on is basically precipitation of your hazardous fluid. If you find that it is perspiring from your primary containment apparatuses then that presents a risk to the site, particularly if it threatens to exceed the capacity of the sump. If you find that run-on is persisting with your primary containers, then ensure the containment of the material with secondary containment measures...though you may also want to replace your primary containers if it is possible and if the problem is too severe.
Exceeding Allowable Capacity
The Environmental Protection Agency has a limit for how much oil can be stored in a particular facility, both above ground and below ground (the above ground limit is 1,320 gallons or 4,997 liters of oil, the below ground limit is 40,000 gallons or 15,416 liters). Exceed this limit, and not only does a company have to submit a written plan detailing how they will avoid discharge and oil spills into navigable waters, but they also have to provide secondary containment systems to mitigate these risks. If you happen to be in the oil industry and see expansion on this scale in the future, you might as well plan for this expense and chalk it up as an investment. It's a good thing to do anyway.
Secondary containment is also important to have when it comes to mitigating the potential damage done during the course of loading and unloading should a loading or unloading rack fail. You can always check the integrity of your equipment, but at the end of the day it is far too easy for something to break or fall over the course of many different transfers. Instead of just hoping that this will never happen, cover your bases by investing in secondary containment. Besides, in many cases the EPA will require it, so it is another instance in which you may need to invest in such a measure just to remain in regulatory compliance.
Potential Failures or Discharge
One thing that should definitely spur you to invest in secondary containment measures is the possibility for any type of discharge of hazardous or volatile liquid (particularly from bulk storage containers). This could happen for any number of reasons, but if, as the manager or owner of your particular facility, you can foresee a scenario in which a mechanical failure, a power shutdown, pipe bursting, or other type of mistake or malfunction might lead to a scenario in which liquid might lead or spill aggressively, then it is probably wise as a preventative measure to put some capital into acquiring secondary containment units. You may never need it, but as the saying goes, it is better to have something and not need it then to need something and not have it.
There are different types of scenarios in which you might need to invest in secondary containment measures. There are different options for this aside from spill pallets and larger containers. Drain covers which can be used during the course of a spill to block passage of fluid through a single channel is a useful and inexpensive method of secondary containment. Having a gate valve that closes in order to head off an oncoming discharge is also, in some circumstances, an effective means of secondary containment.
What is important is that you look at not only things that may be going wrong but things that also may go wrong, depending on certain circumstances in the future. Knowing your facility, knowing your operation, and understanding the risks present and potential should allow you to make an informed decision as to whether or not this is an investment that you need to make. But do remember that it is always better to be safe than sorry.