Recent Gas Explosions Raise Questions of U.S. Pipeline Safety

A series of natural gas explosions has raised questions about the safety of the nation’s aging pipeline system.

The National Transportation Safety Board (NTSB) has scheduled a hearing March 1-3 concerning results of an investigation into a San Bruno, CA pipeline explosion caused by a faulty pipe and will discuss concerns about the pipeline infrastructure in the United States.

According the U.S. Department of Transportation (USDOT) Pipeline and Hazardous Materials Safety Administration (PHMSA), there are more than two million miles of pipelines in the U.S., delivering trillions of cubic feet of natural gas and hundreds of billions of ton/miles of liquid petroleum products each year.

Nearly a quarter of the nation’s gas pipelines are now more than 50 years old. In response to the aging pipeline infrastructure, the U.S. Department of Energy’s Fossil Energy program is working on ways to improve their safety and performance, but most of the technology is a long way away.

A number of natural gas pipeline explosions have happened recently across the United States:

• On February 8, the rupture and explosion of a 36-inch natural gas pipeline near Hanoverton, OH could be seen from 30 miles away. It damaged one home. County officials said they were lucky, that the explosion would have been more serious if it had occurred in one of their cities. El Paso Corp. shut down the county’s pipeline, part of the Tennessee Gas Pipeline, pending investigation and repair of the pipe failure.
• The day before in neighboring PA, a natural gas explosion of a home in an Allentown residential neighborhood killed five people, leveled two homes and damaged the structure of six more houses so severely they required demolition, reports The New York Times. Investigators are investigating the condition of the 12-inch low-pressure gas main, which dates back to 1928.
  “Since the incident, we have thoroughly surveyed every foot of pipeline in the area, and we will be testing the soil around the pipeline for additional clues to the cause of the accident,” said UGI Utilities, a subsidiary of UGI Corp. of Valley Forge, PA, in a statement regarding the Allentown explosion. “We continue to work closely with the Pennsylvania Public Utility Commission to investigate and determine exactly what happened and why.”
• In a residential subdivision northeast of Philadelphia, PA on January 19, 2011, as employees of Philadelphia Gas Works responded to reports of a gas smell and discovered a 12-inch gas main break, an explosion occurred. That event killed one person, injured five more and damaged nearby buildings and vehicles.
• The most devastating natural gas pipeline explosion recently occurred in September 2010 in San Bruno, CA. A 50-inch Pacific Gas & Electric pipeline in a residential neighborhood exploded and caused the death of eight people and injured fifty more. The resulting fires swept through the neighborhood, destroying 37 homes and damaging eight. The investigation found that the pipeline, installed in 1956, had numerous weld defects.

From 2005 to 2009, there was an average of 282 significant incidences involving pipelines in the U.S., including an average of 51 injuries and 14 fatalities. The PHMSA classifies “significant” as one resulting in fatality or injury requiring hospitalization, incident costing more than $50,000, a release of 5 barrels or more of volatile liquid or 50 barrels of other liquid, or liquid release resulting in unintentional fire or explosion.

Until robots can zip through, inspect and photograph the millions of miles of pipeline as the U.S. Department of Energy envisions, the USDOT and the Pipelines and Informed Planning Alliance (PIPA) developed recommendations to enhance pipeline safety in communities.