The post What You Can Learn About Pipeline Leaks From Government Statistics first appeared on the ISA Interchange blog site.
When designing safety and protection systems, it is always useful to understand the nature of the threat. To that end, the U.S. Department of Transportation (DOT) has accumulated data and statistics regarding leaks on regulated pipelines. Some years ago, my company, EFA Technologies, used DOT data to explore the causes of pipeline leaks over a 10-year period. The results of that work were published and are included in Detecting Leaks in Pipelines as Appendix I.
The DOT categorized reported leaks into six specific categories plus one labeled “Other.” Over the 10-year study period there were 1,901 leaks that required reporting for one reason or another. This chart shows the causes distributed across the classification categories:
The “Other” category includes just over a quarter of the accidents, indicated to be the result of vandalism, gasket failure, “bullet hit the pipe” and a diversity of even more obscure issues which serve to remind us that it is hard to foresee and plan for everything. Appendix I in the book includes a lot more detail than we can explore here. The inescapable conclusion is that while many leaks can be prevented by planning, design, construction, maintenance, and management there are many that cannot. Damage by others, for example, was the cause of nearly three-fourths of the “Outside Force” accidents. In a subsequent paper (also in Detecting Leaks in Pipelines), I explored the higher accident frequency at “crossings,” places where a pipeline crosses some other right-of-way such as a railroad, highway, or utility easement.
Clearly, some of the categories can be mitigated by the operator companies. A lot of thought, for example, goes into specifying the metallurgy of line pipe and the anti-corrosion measures that are appropriate on both the inside and the outside. Pipelines, though, often move past their initial purpose and past their design life. Changing the use of a pipeline, or the fluid in it, or the rate-of-flow, or even features of the installation environment, may suggest different design criteria than what were originally appropriate, perhaps even optimal.
The accident statistics investigation also explored the cost of leaks. As one would expect, nearly any leak results in costs in the tens of millions of dollars, and seems to be increasing over time. About a third of the documented costs involve property damage and cleanup. The rest go to fines, legal costs, and other legally mandated assessments. During this period the president of a major pipeline operator observed that while the costs associated with any accident are significant, the loss of good will by those who will not forget what happened is beyond calculation. Another industry icon, Constantine Nicandros, then president of CONOCO Inc, observed, “Every company in this business may be judged by the performance of the worst among us.” He went on to say that, “We can be sure that if we do not police ourselves, others will be more than happy to take up the task. I believe that in the days ahead our industry will thrive if we do a better job of listening to the public and earning their trust.”
These observations by these industry leaders help answer the question, how important is pipeline safety? They also suggest an analysis of what is required by mandate or regulation may be a subset of what is truly necessary or desirable.
These are old data but were stable during the study period and a couple of decades around them. Only the accident cost showed an upward trend. Appendix I shows a lot more detail.
When this study was done, theft was involved in only a small number of operations. In the U.S., that’s probably still true. In many parts of the world, though, theft is a significant safety and financial hazard. If one were to revisit this study it would be very interesting to assess the impact, if any, of the increase in theft that we see in some parts of the world.
This study is a good place to start evaluation of the risks confronted by any pipeline operation. It provides a good list of threat causes and an assessment of the significance of each of them. While things change over time, and while they vary in each situation, these are factors that should be considered, but as time moves along, perhaps not all the factors that could be involved. Fortunately, there are processes for analyzing risk and some features of those will be discussed in a future blog post.
Did you miss the first post in this blog series? Click this link to read it.
Source: ISA News