Frequently-Asked Question FAQ #149

FAQ-149: Class 3 and 4 Areas as per se HCAs

Question: Must an operator treat all of its class 3 and 4 areas as high consequence areas?

Answer: No. Section 192.905 requires that an operator use either method (1) or method (2) from the definition in 192.903, not both. If an operator elects to use method (1) on a pipeline segment, then all of the class 3 and 4 areas associated with that segment will be considered HCAs. If, on the other hand, an operator chooses to use method (2) on a pipeline segment, then potential impact circles would be drawn and some areas that are class 3 might not be determined to be HCAs. An operator can select one method to use for its entire pipeline or can apply either method to individual segments of its pipeline.

Operators of pipelines operating below 30% SMYS who use method (2) should recognize that there are some requirements in section 192.935(d) that apply to class 3 and 4 pipelines that are not in HCAs.