Secondary Location Classes
Referenced Section: AS/NZS 2885.6 S 2.4 Secondary Location Classes
Q: What do I need to know if I assign the Secondary Location Class "HI" to a site?
A: (Susan Jaques) When assigning secondary class "HI", be sure to also do a consequences assessment in order enable the requirement that "... depending on the assessed severity, the requirements of R2, T1 or T2 apply". In other words, assigning "HI" requires the next step of declaring which of R2, T1 or T2 requirements apply to that site.
Q: What is the difference between secondary location class "S" (Sensitive) and "E" (Environmental)? (Secondary Location Class "E" is new in 2018).
A: S location class is specifically about protecting vulnerable people. Clause 2.4(b) includes the words "... land developed for use by sectors of the community who may be unable to protect themselves ...". E location class is specifically about protecting the environment. "... locations of high environmental sensitivity to pipeline failure ...".
The failure consequences and protection requirements may be quite different for these two situations so this revision of the Standard makes a clear distinction between them. (Peter Tuft)
Q: Is “C” (Crowd) coupled to “S” (Sensitive) (or can it be coupled) for exposure within the measurement length?
No, coupling or doubling up on Secondary Classes is not an intended approach. C (Crowd) is a secondary location class independent of S (Sensitive), and in fact has been created to not over-specify an infrequent gathering of people as an "S" secondary location classification. This may result in adding undue controls and costs. Each C (Crowd) location needs to be looked at individually to determine appropriate controls treatment. (Jeff Jones)
Q: Would a water course used for drinking water, be assessed as Secondary Location Class "E", or "S"?
I would go with "E", but just test it with both severity scales and go with the more conservative, that is Risk Assessment 101. (Jeff Jones)
Jeff is right about picking the more conservative outcome. In terms of Location Class I would probably go for "E", but as long as you are aware of the associated issues, it is not worth obsessing over which Location Class is more appropriate. More important is identifying the threats, applying controls and assessing any residual risk. Location class is just a pointer to help focus attention on the most important consequences. (Peter Tuft)
Q: Medium-sized compressor stations within measurement lengths are now not considered as "HI" (Heavy Industrial) Secondary Location Class in AS 2885.6?
(Peter Tuft) I don't read the current wording as suggesting that an ordinary compressor station could/should be HI. I'd be interested in how you reach this interpretation (so that if necessary it can be made clearer next time).
(Simon Gillice) The location classification assessment for a compressor station may still decide to apply a secondary location classification of HI - though this may be conservative. Have a read of the following for more guidance:
(Jeff Jones) The intent of HI is to reflect the potential broader impacts of a pipeline failure and societal impact from adjacent heavy industrial plant within the measurement length. A compressor station is generally part of a pipeline system and inherently covered off in the design, construction and operation of the pipeline system. Essentially, location classification is for external public (population) consequence impact. Workers at the station are also covered under Part 3 WHS obligations and protection measures.