4. 4
Acceptable Risk Tolerance Level
To prepare a risk response plan we need to know the
Acceptable Risk Tolerance Level from Natural
Events (Seismic, Ice Storm, Wind Storm etc.) for
infrastructure elements (utility, road system etc.) by
the company and the public (social acceptance of
loss levels)
5. 5
Acceptable Risk Tolerance Level
From CAN/CSA-Q850-97 (Reaffirmed 2002) Risk Management: Guideline for Decision-Makers
7. 7
Acceptable Risk Tolerance Level
• Company and Public Risk Tolerance could be very
different !
• Recent wind an snow storms in BC created extended
electrical outages for customers.
8. 8
Recovery and Restoration Times
• Acceptable recovery and restoration times for
infrastructure components (hours, weeks or
months?)
• Company and public requirements could be quite
different.
• Public usually requires quick response
• Companies have limited resources to respond.
9. 9
Answers Required
When we can get reasonable answers for these
questions we can plan for an event (potential
disaster) and mitigate its impact within our resource
and political constrains (cost of service delivered).
Currently there is no coordinated risk tolerance level
among utilities. NBCC 2005 has requirements for
new construction, mainly buildings, but many
existing system elements do not meet these
requirements and some items are outside the scope
of the code, for example transmission lines and
substations.
10. 10
Answers Required
What can we do now? Upgrade to some technically
reasonable risk tolerance level, usually defined
within companies.
Is this acceptable by the public?
