As an owner/operator of a UST system you are probably aware of the widespread requirements for secondary containment are fast approaching. Depending on what state you are in, you may already be feeling the effect of having to upgrade your older single-walled systems. Fortunately, installation requirements and best practice standards have pushed the industry toward double-walled tanks and piping for some time now. So, if you have an existing UST facility with double-walled tanks and piping, STP sumps, and dispenser pans, then you would think you’re in the clear. But, not so fast. Having these pieces of equipment as secondary containment is only half of the battle. The second half is making sure that those containments are TIGHT. What good is a STP sump if the liquid that enters it is leaked out?

Secondary containment is typically tested for tightness at installation. This means performing a pressure or a hydrostatic (filling with water) test to make sure that a containment will safely contain any product that is leaked into it. But a passed test at installation does not mean the containment will stay tight forever. Rubber boots dry out, fittings corrode, and equipment just ages with time. Regular testing of secondary containment has not typically been required, so the level of tightness for a not so recently installed secondary containment may be a complete unknown. Some older containments installed as “best practice” prior to being required, may have never even been tested at all. Some DW piping may have been installed in a way that does not even allow the interstice to be tested. So if you are relying on an older double-walled system or containment sump to meet a new requirement, make sure it is fit to do its duty, have it tested. And depending on the requirements in your area, you may have to test. 

Though it may not be required in your area right now,  a best practice for your double walled system is to test is and perform regular maintenance to verify that your secondary containment is tight.

- Troy Dickens, Field Services Technician