In the last decade, there has been a rash of natural gas explosions in America caused by failures in cast iron pipelines. At Glenda Cochran Associates, we have represented a number of individuals injured in cast iron pipeline explosions, which are only likely to increase over time if cast iron pipelines are not replaced by upgraded, newer systems.

As America’s infrastructure grew during the last century, a large number of natural gas distribution pipelines were constructed using cast iron pipe. As this cast iron ages, however, a distinct and dangerous hazard presents a new risk to the public: the phenomenon of graphitization.


Graphitization occurs when older cast iron pipelines corrode due to normal environmental exposure. It can and often does result in catastrophic leaks throughout a pipe system, which can lead to fires and explosions. The Pipeline and Hazardous Materials Safety Administration (PHMSA), a sub-department within the United States Department of Transportation (DOT), has explained the hazard associated with cast iron pipelines, stating:

“Cast iron pipe, when graphitized, is relatively brittle, which allows far more dramatic failure modes such as rapid crack propagation and circumferential breaks. Such failures are potentially more severe than more ductile failure modes commonly seen in today’s pipe materials.” [PHMSA’s “192 Corrosion Enforcement Guidance” at 134 (2014)]


Because of the hazards associated with cast iron pipe, natural gas pipeline operators are required by federal regulations to replace any portion of an iron or ductile iron pipe with enough graphitization to increase the chances of a crack or leak to form there. Where graphitization is localized within the pipework, repairs or replacement must also be conducted as soon as possible, according to the legal statute 49 C.F.R. § 192.489 (1971). Additionally, pipeline operators are required to visually inspect its cast iron pipelines for corrosion and graphitization any time that they are exposed.

In 1991, PHMSA’s predecessor, the DOT’s Research and Special Programs Administration (“RSPA”), issued a Pipeline Safety Alert Notice (the “1991 Alert Notice”) to the owners and operators of natural gas pipelines regarding an explosion caused by a crack in a 4-inch cast iron gas main. This notice required gas and oil companies to create new safety programs that would repair or replace the iron pipes throughout their systems based on a reasonably paced timeline.

Each company’s timeline would be determined by various conditions of their pipelines, such as:

  • Age
  • Diameter
  • Depth
  • Average system pressure
  • Surrounding soil acidity
  • History of leaks and defects

In 2012, PHMSA published an Advisory Bulletin reiterating the importance of cast iron monitoring and replacement. According to the bulletin pipeline operators were instructed to increase their efforts to repair or replace “high-risk” cast iron pipes, as well as to revisit their replacement programs to ensure the aforementioned factors were accurately considered. [Pipeline Safety: Cast Iron Pipe (Supplementary Advisory Bulletin), 77 Fed. Reg. 17119-01 (Dep’t of Transp. March 23, 2012) (emphasis added).]

The 2012 Advisory Bulletin also specifically refers to operators’ obligation to develop and implement a Distribution Integrity Management Plan that must include procedures for identifying risks to each distribution pipeline, rank the associated risks, and implement measures to address them. [49 C.F.R. § 192.1007(b-d) (2009).]

While some operators have worked hard to replace their cast iron pipelines as quickly as possible, others have lagged behind, and there are still thousands of miles of cast iron pipelines throughout the United States. If you or someone you know has been injured or killed in an explosion or fire caused by a natural gas leak from a cast iron pipeline, you may be entitled to compensation and need to seek legal counsel. Call Glenda Cochran Associates Attorneys at Law at 888.906.3955 to discuss your claim. We assist clients across the nation.