According to the U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration (PHMSA), a total of 5,806 significant pipeline incidents occurred in the United States from 2003 to 2022, resulting in 252 fatalities, 1,081 injuries requiring in-patient hospitalization, and approximately in $12.8 billion in costs.  While PHMSA's data suggests that a significant pipeline incident occurs nearly every day, very few of these events have a profound or lasting impact on public policy.  Understanding the reasons for that disparity will leave stakeholders in a better position to predict--and, more importantly, influence--the direction of the pipeline safety program in the future.  

An examination of historical case studies, including natural gas pipeline incidents in New London, Texas (1937), Natchitoches, Louisiana (1965), Queens, New York (1967), San Bruno, California (2010), and Merrimack Valley, Massachusetts (2018), a hazardous liquid pipeline incident in Marshall, Michigan (2010), and an underground gas storage incident in Aliso Canyon, California (2016), demonstrate that several factors can turn a pipeline incident into a transformative event from a public policy perspective.  Those factors include the magnitude of the consequences, the timing, location, and cause of the incident, and the presence other forces that heighten the public's interest.  The last factor concerning the public interest has grown in importance over the years with the emergence of more robust regulatory authorities, aggressive advocacy groups, and widespread media scrutiny of pipeline incidents.

Starting with the enactment of laws requiring the odorization of gas distribution lines in the wake of the New London, Texas incident, and continuing with the adoption of more stringent laws and regulations in response to incidents in the modern era, these historical case studies also illustrate the lasting impact that such events have from a public policy perspective.   Growing public interest indicates that trend is likely to continue in the future.