Yet, despite the coverage, the obvious damage, claims and counter-claims, it’s difficult to place these events in the overall context of pipeline safety without looking at longer time frames. Fortunately, the Pipeline and Hazardous Materials Safety Administration (PHMSA) maintains a comprehensive database of all pipeline incidents reported in the U.S.
Using data from 1993-2012, we focused on onshore and offshore pipelines carrying hazardous liquids (primarily crude oil and refined petroleum products) that suffered what PHMSA classifies as “significant incidents.” To qualify, a “significant incident” must satisfy one or more of the following criteria:
- a fatality or injury requiring in-patient hospitalization;
- $50,000 or more in total costs, measured in 1984 dollars;
- highly volatile liquid releases of 5 barrels or more, or other liquid releases of 50 barrels or more;
- liquid releases resulting in an unintentional fire or explosion.
Of 5,727 reported incidents during 1993-2012, 2,079 met the PHMSA definition of “significant incidents,” accounting for 99.4% of the total volume spilled.
Surprisingly, perhaps, the number of significant incidents has declined in recent years, with only one year of the past 10 exceeding the 20-year average.
On the other hand, costs related to property damage, including the loss of goods being transported, have increased markedly in the most recent decade. Total property damage over the 20-year period from spills of hazardous liquids amounted to $3.2 billion — with 74% of that occurring from 2003-2012.
The spike in the graph below for 2010 reflects losses due to the Enbridge pipeline spill near Marshall, Michigan — the costliest onshore spill in U.S. history.
Volume Spilled vs Volume Recovered
Despite the massive 2010 Enbridge spill, the total volume of hazardous liquids spilled has declined in the most recent decade (1 billion barrels) compared to the previous decade (1.4 billion barrels).
The percentage of oil recovered, however, has declined somewhat, from 41% in 1993-2002 to 38.4% in 2003-2012.
Looking at the causes of significant spills, nearly half were related to pipeline construction, equipment failure, and corrosion, suggesting that better engineering, more rigorous inspections, better monitoring and proper maintenance could go a long way toward reducing significant pipeline failures.