The US National Transportation Safety Board (NTSB) has released a synopsis of its near-final report on the San Bruno pipeline failure of September 9 2010 in which eight people died and many more were injured. Despite being a synopsis it’s quite long so I may comment on different aspects of it separately. But I want to start with the report’s clear recognition that this was an organisational failure.
There is a long list of findings but I’ll highlight just a few that deal with organisational failure rather than the physical mechanisms:
21. The deficiencies identified during this investigation are indicative of an organizational accident.
22. The multiple and recurring deficiencies in PG&E operational practices indicate a systemic problem.
27. The ineffective enforcement posture of the California Public Utilities Commission permitted PG&E’s organizational failures to continue over many years.
It goes on to outline the probable causes of the accident of which the main features (paraphrased) are:
- Inadequate QA and quality control during the 1956 construction of the pipeline (the longitudinal seam in the pipe was only half welded)
- Inadequate pipeline integrity management, which failed to detect and repair or remove the defective pipe section
- Regulations which “grandfathered” existing older pipelines, exempting them from pressure testing (the line had never been tested to the modern standard of 125% MAOP)
- Lack of automatic or remotely controlled valves and flawed emergency response procedures, which resulted in a 90 min delay before the ruptured pipeline could be shut down
These are all ultimately organisational failures, in either PG&E itself as the pipeline owner and operator or in the pipeline regulators (both state and national). The NTSB report recognises this and makes quite scathing criticisms of both PG&E and (to a slightly lesser extent) the regulators for their inadequate oversight and grandfathering of old pipelines built to inferior standards.
The report synopsis also contains a long list of findings about other physical and organisational aspects of the failure, and a long list of recommendations to both regulators and PG&E. I may comment further on these in due course.