Q. In doing calculations for the size of containment, can you include the equilibrium volume of the inside of the storage tank as part of the containment volume? How often should a tank have integrity test done?
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A. The Spill Prevention, Control, and Countermeasure (SPCC) regulations are performance based, not prescriptive, and as a result, they do not require specific containment methods, only that they be consistent with good engineering practice.
The general secondary containment provision requires that areas be designed with appropriate containment and/or diversionary structures to prevent a discharge in quantities that may be harmful (i.e., a discharge as described in §112.1(b)). “Appropriate containment” must be designed to address the most likely quantity of oil that would be discharged from the primary containment system (e.g., container, equipment), such that the discharge will not escape secondary containment before cleanup occurs. In determining the most likely quantity, the facility owner/operator should consider factors such as the typical failure mode (e.g., overfill, fracture in container wall, etc.), resulting oil flow rate, facility personnel response time, and the duration of the discharge.
Calculations may be provided as part of the documentation to support the adequacy of secondary containment measures employed at the facility, although they are not required. Nevertheless, the Plan preparer must include enough detail in the SPCC Plan to describe the efficacy of the measures used to comply with the general secondary containment requirements in §112.7(c).
Similar to the secondary containment regulations, the regulations do not specific an exact schedule for integrity testing. Aboveground containers must be integrity inspected on a regular schedule and whenever material repairs are conducted. Owners and operators must determine, in accordance with industry standards, the appropriate qualifications for personnel performing tests and inspections and the frequency and type of testing and inspections, which take into consideration container size, configuration, and design. Examples of such tests include visual inspection, hydrostatic testing, radiographic testing, ultrasonic testing, acoustic emissions testing, or other systems of nondestructive testing.