An alarm has sounded over the nation's natural-gas pipelines that snake underground across the lower 48 states.
Fourteen people are dead, dozens injured and entire neighborhoods are gone in the wake of three massive pipeline explosions in San Bruno, Calif.; Philadelphia and Allentown, Pa., over the past six months.
The problem is so serious The National Transportation Safety Board is set to hold hearings this week to gather additional information into the San Bruno explosion, and any information that could help prevent further incidents.
More than 2,800 significant gas pipeline accidents have been recorded across the country since 1990 -- a third of them causing deaths and significant injuries. There are more than 210 natural gas pipeline systems, made of cast iron, steel, and plastic with more than 21,000 miles running through heavily populated areas. That's a dangerous combination, say watchdog groups.
Rick Kessler, with the watchdog group Pipeline Safety Trust, tells Fox News, "Pipelines are really the safest way to transport natural gas, and the question always is, 'are they as safe as they could or should be?' 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." Kessler adds, "Cast iron pipe will fail and the law always envisioned that these things would be replaced over time.
"Well, here we are more than a century later and we still have these things in the ground… they are kind of a ticking time bomb."
By law, private and public pipeline operators are required to conduct leak surveys, which continue to be one of the most important ways to ensure the safety of the lines.
While the pipeline that broke in Allentown was more than 80 years old and made of cast iron, experts say age is just one factor in judging the integrity of a pipe, adding, old lines don't necessarily mean imminent disaster.
Joseph Swope, communications manager with UGI Utilities in Pennsylvania explains, "other factors include the leak history of the pipe, the composition, the population density around the pipe, the geography, the road, the traffic patterns."
Swope explains, "The equipment used is very sensitive, but it's actually very easy to use. The people who use those surveys have to be certified and qualified. It's not something that anybody can go down to the Home Depot and pick up -- a you know, survey a gas sniffer and figure out what’s going on -- but they go through very rigorous training. They're qualified to do that work and to identify what they're looking at."
Federal pipeline regulators say safety is a top concern. The Obama administration is implementing new regulations that include additional pipeline inspectors and establish more stringent leak detection measures. But as more incidents are being reported, nerves are being rattled for some who have concerns of what lies beneath their front yards and homes.
Richard Kuprewicz, an independent neutral pipeline safety expert and president of Accufacts Inc., in Redmond Wash., says if people are concerned they need to start asking questions. Kuprewicz suggests contacting your local pipeline operators to ask about the regulations that are in place for the types of lines being used where you live, and to find out if those operators are following the regulations.
He says you should be able to get good general information from a pipeline operator, and if you don't, contact your local congressman.
Laura Ingle currently serves as a New York-based correspondent for FOX News Channel (FNC) and also frequently anchors FOXNews.com/LIVE. She joined FNC as a Dallas-based correspondent in 2005.