Q. Why are “process” tanks like hydraulic reservoirs considered as storage in the calculations?
A. Hydraulic reservoirs are considered “oil filled operational equipment” in the SPCC regulations because they exist to spurt the function of the apparatus of the device. Owners and operators may either provide adequate secondary containment for this equipment, or if that is impracticable, opt for the optional alternative to the general secondary containment requirements for oil-filled operational equipment as described in 40 CFR 112.7(k).