A sharp increase in natural gas leaks has plagued neighborhoods across North Texas this year, from Irving to Oak Cliff to Preston Hollow.

Large swaths of north and northwest Dallas had more hazardous leaks during the first half of 2018 than in any year since 2015, according to a Dallas Morning News analysis of data filed with state regulators by Atmos Energy Corp.

These leaks — the most serious type, which required immediate fixes — were reported along neighborhood gas lines that snake through working-class areas between Dallas’ two major airports, as well as tony North Dallas streets dotted with multimillion-dollar homes.

Atmos found so many natural gas leaks in northwest Dallas that it now plans to replace a pipeline network covering an area more than four times the size of White Rock Lake.

In some zip codes of Dallas, Atmos Energy reported more leaks in the first part of 2018 than in any of the three previous years. A Dallas Morning News analysis found several hot spots outside the one northwest Dallas neighborhood rocked earlier this year by fires and a fatal explosion. (Ben Torres / Special Contributor)

This gas line replacement extends well beyond the northwest Dallas neighborhood where leaks fueled three explosions and fires in February, including one that killed 12-year-old Linda Rogers. Those blasts launched a federal investigation and prompted Atmos Energy to replace aging pipelines to 2,800 homes in that neighborhood.

Since then, Atmos has done more frequent searches for gas leaks in the Dallas area using high-tech tools, the company said in a statement Friday.

"As would be expected, the result has been a higher number of found and repaired leaks ultimately enhancing the safety of our system," the statement said.

Our data analysis reveals potential widespread problems with aging and wear and tear in the gas delivery system running under customers’ homes and businesses all over Dallas County.

Of the 3,100 leaks Atmos reported in Dallas County during the first half of 2018, nearly 1,400 were deemed hazardous — the type most likely to cause explosions and fires if not repaired quickly. These kind of leaks have destroyed dozens of homes in Texas, sometimes injuring or killing people.

For our analysis, The News excluded the roughly 600 hazardous leaks caused by digging mistakes or car crashes. We focused on the remaining 800 hazardous leaks that Atmos attributed to all other causes. The most common were stripped pipe threads, corrosion, and aging or failing parts.

Across Dallas County, this subset of dangerous gas leaks more than tripled during the first half of 2018 compared with the first half of 2017, The News found.

Our analysis identified clusters of leaks that were repaired near Preston Hollow Elementary School; between the Trinity Groves and Sylvan Thirty developments in West Dallas; and along rail lines east of the downtown Irving DART station.

The majority of hazardous leaks The News analyzed happened on steel or plastic pipe. Atmos has pledged to rid its North Texas system of older cast iron pipes by 2021.

The state requires natural gas companies to report each January and July the number of leaks they repaired during the prior six months, along with the leak locations and other details. The reports do not include leaks that have yet to be repaired.

When The News first asked Atmos about the rise in leaks, the company posted an announcement on its website touting its commitment to safety and asserting that it fixes hazardous leaks quickly. Atmos said it found "isolated areas" with a high number of leaks outside the northwest Dallas neighborhood of Midway Hollow, but did not say where.

More neighborhoods affected

Gas utility crews surrounded by orange cones and road signs have become common sights in several neighborhoods west of the Dallas North Tollway and south of the LBJ Freeway.

That's an area The News identified as having a sharp increase in hazardous gas leaks so far in 2018.

In March, Mary Jane Mackenna woke to a ringing doorbell at 5:30 a.m. at her northwest Dallas home near Royal Lane and Aladdin Drive.

Men in orange vests were scrambling in her yard, with six work trucks behind them. They had found a dangerous leak near the curb in front of her oak tree, and immediately began working to fix it.

She wondered if she needed to evacuate, but was told she could stay in her home while crews dug up her yard and replaced a leaking steel pipe with a more durable, flexible plastic one.

The gas leak in her yard was fixed quickly since it was the most hazardous type. But she wondered: What about my neighbors? Are their gas lines leaking, too?

Other types of leaks can linger longer under state regulations, which troubles Mackenna.

“You mean they don’t have to fix all of them right away?” she said. “What they need to do is replace everybody’s lines. They were supposed to do this a long time ago.”

The News found several hazardous leaks reported in Mackenna's neighborhood that were repaired the same month as hers. Now, Atmos Energy plans to replace her entire neighborhood's pipelines and much of those in the surrounding area by 2019, according to a report the company gave to state regulators this month.

When The News asked Atmos last week if customers in those neighborhoods had been notified of this plan, Atmos declined to answer. The next day, the company posted its announcement online and emailed several Dallas City Council members to notify them.

“The NW Dallas distribution system is operating safely as it had been performing in the months and years before February and March 2018,” Atmos said in that statement.

This is the home in Midway Hollow where Linda Rogers, 12, died in February. Her house exploded after a gas leak and several fires were reported in the neighborhood, but Atmos did not cut off gas or evacuate. (Vernon Bryant / Staff Photographer)

Dallas City Council member Jennifer Gates, whose district is in part of the planned replacement area, said she was notified about two months ago that Atmos might upgrade gas lines across a large swath of northwest Dallas.

“It would have been nice if this had been replaced before we started having all the leaks,” Gates said. “But the response now, that’s what needs to be done. My concern is we follow through and make sure everything is repaired.”

An aging system

Atmos inherited an aging system when it acquired Lone Star Gas Co. from TXU in 2004, said Geoffrey Gay, a lawyer who represents more than 150 cities in rate negotiations with the utility.

“I suspect there’s a lot of old pipe out there that is desperate to be replaced,” Gay said.

Upgrading the entire system is likely to send customers’ gas bills higher, he said.

An Atmos Energy gas truck patrols a Dallas neighborhood. (Tom Fox / Staff Photographer)

Atmos Energy, based in Dallas, is among the country’s largest natural gas distributors, serving more than 3 million utility customers in eight states. Officials said the company has invested $3 billion since 2005 to upgrade its Mid-Tex system, which includes north and central Texas.

Atmos plans to replace 292 miles of gas distribution pipes on that network in 2018, according to reports filed with state regulators.

In a July 12 letter to state officials about the increase in leaks, company executives said “a constructive rate environment is necessary” to fund improvements.

Last year, Atmos secured permission from state regulators to get more than $9 million in increased rates from customers. This year, the company initially asked for a $6.3 million increase but agreed to settle for far less after receiving a massive federal tax break.

Atmos maintains the 2018 surge in leaks for its north and central Texas system is largely due to clusters of “abnormal, sudden and unexplained” leaks in one part of northwest Dallas. This includes the neighborhood where three houses were destroyed by fires and an explosion in February. Atmos said it found more leaks there in one week of 2018 than in all of 2015, 2016 or 2017.

The company has blamed this phenomenon on heavy rains and “unique” soil and geology conditions in the area.

But that wasn't the only area The News found with more leaks: In Preston Hollow (the north Dallas ZIP code 75230), there were 40 leaks in the first half of 2018, compared with 39 dangerous leaks in all of 2015 to 2017. (Excavation damage caused an additional 10 hazardous leaks in the first half of 2018 and about 50 leaks from 2015 to 2017.)

Linda Michelle Rogers was killed in the Feb. 23 explosion at her home in northwest Dallas. A preliminary investigation by federal authorities found a gas leak in the alley behind her home. (KXAS-TV)

While Atmos was replacing leak-riddled pipelines in the neighborhood where Linda Rogers died, it was monitoring other areas of Dallas with high-tech leak detection equipment described as a thousand times more powerful than traditional tools.

As for the exact areas that Atmos monitored, the company said it included ones where The News found a notable increase in hazardous leaks.

The recent rise in gas leaks isn't necessarily a bad thing, as Atmos sees it.

"Finding and repairing leaks is evidence that we operate our system safely," the company said in a statement.

The News asked Atmos what specific leak technology it is currently using in Dallas and throughout Texas, and whether it's the "state-of-the-art" detection equipment the utility told regulators it used this past March.

The company did not answer those specific questions, saying only it "continuously evaluates and incorporates new, more sensitive technology into its leak surveys."

Staff writer Robert Wilonsky contributed to this report.

HOW WE DID OUR ANALYSIS

Atmos and other natural gas companies must report the number of leaks they repair to the state twice a year. The reports include where the leaks were found, how serious they were graded, what caused them and how they were fixed.

Atmos submitted its most recent leak report to state regulators on July 12, covering leaks repaired between January and June 2018. The report excluded an unknown number of leaks that are part of a federal investigation into the fatal Feb. 23 explosion in northwest Dallas.

For its analysis, The News focused on Dallas County's most dangerous leaks, called Grade 1. We identified the zip codes for all the leaks and compared how many occurred in each area over the past three years.

We excluded leaks caused by digging and similar accidents — for instance, a construction worker who punctures a pipe with a backhoe. Those leaks usually happen because the excavator made a mistake — not because the pipes are old or corroding.