City gas pipes corrode

By Monica Mitrovic
Copy Desk Chief

In the U.S., gas leaks have destroyed property, hurt or killed someone about every other day between 2004 and 2014, according to USA Today. On average, 17 people die in the U.S. because of leaks and explosions caused by natural-gas pipelines each year, according to The Atlantic.

On Feb. 23, a natural gas explosion killed 12-year-old Michelita Rogers in Northwest Dallas, according to wfaa.com. Two days before that explosion, two other nearby homes caught fire or exploded. On April 2, four people in South Dallas were injured in an explosion thought to be caused by a gas leak, according to nbcdfw.com.

Atmos Energy officials blamed unforeseen shifting soil conditions for the Feb. 23 house explosion, according to wfaa.com. Cast iron and steel gas pipes can become stressed under shifting soil and leak, according to the Denton Record-Chronicle.

Natural gas is piped into 67 million homes and at least 5 million businesses, schools and other buildings across the nation, according to USA Today.

In an email to The Courier, Gary Jones, Brookhaven College geology adjunct faculty, said North Texas has soils with a lot of clays in them. “When they get wet, they expand,” Jones said. “When they dry, they contract.”

According to USA Today, aging bare-metal gas pipes susceptible to rust and corrosion can lead to gas leaks. “Water tends to act as a catalyst in chemical reactions,” Jones said. “Iron is very reactive with oxygen especially when water is present. This is why you see a lot of rust, [or] iron oxide.”  

According to the Record-Chronicle, “When it rains, North Texas clay soils can compound the problem by creating new paths for any leaking gas to migrate and collect, rather than disperse in the air.”

There are more than 300,000 miles of gas transmission lines in the U.S., according to theworldlink.com. There are at least 85,000 miles of cast iron and bare steel gas mains beneath American cities and towns, according to USA Today.

As of July 2017, Atmos has replaced 48.5 miles of cast iron pipe in Dallas over the past three years, according to documents obtained by WFAA through open records. However, 409 miles of cast iron piping running beneath the city.

The Pipeline and Hazardous Materials Safety Administration has pushed gas utility companies to replace aging pipes with tougher materials for more than a decade, according to USA Today. Replacing aging piping can cost $1 million per mile or more. 

As of March 8, 21 states, excluding Texas, have replaced cast iron piping, according to wfaa.com. In a letter to WFAA, Atmos officials said all cast iron pipes in Dallas should be removed by the end of 2023.

“Since we are just starting spring, we expect there to be heavy rainfall through April,” Jones said. “If this is the cause, then it is possible for there to be more gas explosions. The main thing would be to replace the metal pipelines with plastic.”


If there is a leak:

Leave the premises.

Leave any doors open.

Do not turn off or on any electric switch.

Do not use a cell phone, telephone, garage door opener, doorbell or flashlight.

Do not smoke, use a lighter or strike a match.

Do not start or stop a nearby vehicle or machinery.

Do not try to shut off a natural gas valve.

Call 911 and
Atmos at 866-322-8667


According to the Atmos Energy website, signs of a gas leak include a distinct odor, hissing or whistling sound near a gas appliance, roaring sound near a pipeline, or blowing dust, bubbling water or dead vegetation near a gas line.

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