Recent major natural gas explosions could have been prevented
Last month, after a series of deadly accidents, the National Transportation Safety Board (NTSB) conducted hearings on the status of U.S. natural gas pipelines and found that utilities have long resisted implementing recommended safety measures leading to the increased likelihood of fatal explosions; the United States currently has more than 210 natural gas pipeline systems with roughly 21,000 miles of pipeline snaking throughout heavily populated areas; some of these pipes were first put in place more than eighty years ago; utilities could have minimized the damage caused by the recent explosions and even prevented the accidents from occurring had they installed safety valves, conducted regular testing, and replaced aging infrastructure
Last month, after a series of deadly accidents, the National Transportation Safety Board (NTSB) conducted hearings on the status of U.S. natural gas pipelines and found that utilities have long resisted implementing recommended safety measures leading to the increased likelihood of fatal explosions
In the past several months entire neighborhoods in California and Pennsylvania have been bathed in flames after natural gas pipelines exploded killing fourteen people, injuring dozens, and destroying hundreds of homes.
The United States currently has more than 210 natural gas pipeline systems with roughly 21,000 miles of pipeline snaking throughout heavily populated areas.
Some of these pipes were first put in place more than eighty years ago.
Rick Kessler, the vice president of Pipeline Safety Trust, a watchdog organization, said, “Well, here we are more than a century later and we still have these [pipes] in the ground… they are kind of a ticking time bomb.”
Kessler explains, “We do have aging infrastructure and some more than others, a lot of systems are very up-to-date, very safe, but a lot of systems are, in fact, aging. Some are so old that you can’t run the most modern inspection devices through them, and that’s a problem.”
Age alone does not determine the vulnerability of the pipes, but rather a slew of factors.
According to Joseph Swope, the communications manager with UGI Utilities in Pennsylvania, “other factors include the leak history of the pipe, the composition, the population density around the pipe, the geography, the road, the traffic patterns.”
Therefore ensuring the secure operation of these natural gas pipe systems requires frequent inspections, the installation of safety measures like shutoff valves, and other precautions, but utilities have resisted taking such steps.
Investigations by NTSB have revealed that utilities could have minimized the damage caused by the recent explosions and even prevented the accidents from occurring had they installed safety valves, conducted regular testing, and replaced aging infrastructure.
State regulators in California investigating the natural gas pipeline explosion in San Bruno that killed eight people and destroyed fifty-five homes found that Pacific Gas and Electric (PG&E) had put off several critical inspections and used lax assessment techniques.
The California Public Utilities Commission’s audits found that PG&E had delayed critical inspections for more than two years and chose to use less thorough inspection techniques.
Richard Clark, the director of the Public Utilities Commission, said, “We’re certainly concerned about the rescheduling of inspections and the changing of the methodologies.”
PG&E performed external corrosion detection tests, which only look at pipes from the outside to determine if there are any problems, instead of the more thorough in-line inspection which sends a robotic device called a “smart pig” to analyze the interior of pipes for corrosion, dents, or other structural weaknesses.
NTSB investigations have also found that PG&E did not install critical automatic valves to shut off the flow of gas in the event of an accident, despite agreeing to do so in 1997.
According to Professor Theo Theophanous at the University of California – Santa Barbara, “the natural gas industry has downplayed the safety importance of valves” and have chosen not to install them because of their high costs.
Industry representatives say that installing valves on 300,000 miles of pipeline would cost more than $370 million dollars.
Theophanous said, “Valves don’t prevent leaks or breakdowns, but they could have curtailed the damage in the aftermath of the explosion.”
Theophanous believes that the accident would have occurred regardless of the safety valves due to the age of the pipes and the amount of pressure exerted on it, but the resulting damage would have been far less.
“The role of remotely operated or automatic shut-off valves of natural gas pipelines is to minimize the loss of gas in the case of an accident,” he explained. “If they had the valves in place, it would have reduced the fuels that burn by 98 percent.”
NTSB is currently undergoing a thorough investigation of recent accidents and is working to implement new regulations to ensure the safety of natural gas pipelines.
