A small hole formed in an aging natural gas well in southern Denton last fall. Instead of traveling up the casing into gas gathering pipelines, the methane and other hydrocarbons escaped underground.
Powered by pressure from the well, the natural gas moved through cracks and groundwater in the rock for a half-mile or more. Whether it traveled for days, weeks or months isn’t clear. Whether it traveled under the scores of new homes and businesses built along South Teasley Lane remains unclear, too. It appears the methane found a new way to escape to the surface, through an abandoned water well just outside the Denton city limits.
In November, gas bubbles were popping vigorously at the bottom of the well on Isaac Escobar’s land, turning the old pipe into an eerie sounding tubular bell. His neighbor, Charmaine Grace, held a plastic grocery bag over the top of the old pipe. As they videotaped their common-man’s test for gas, the little bag inflated like a balloon.
State inspectors and repair crews descended on the well site the day after Escobar reported the problem to the mis-named Texas Railroad Commission, which regulates the oil and gas industry. They found a leaky gas well a half mile away. Endeavor Energy Resources, the well owner, repaired it, although state officials say they have not connected the well leak to the water well pollution.
“The Railroad Commission’s investigation into whether the source of the gas in the abandoned water well was natural or from area oil and gas facilities is ongoing,” Gaye Greever McElwain, a railroad commission spokeswoman wrote in an email to the Denton Record-Chronicle.
The incident was uncommon, but not unheard of. Regardless of what caused gas to emanate from Escobar's water well, experts say it could happen again and with more serious consequences as more gas wells in the Barnett Shale reach the end of their productive life.
Escobar was lucky. His family wasn’t using the well water. A family in Perrin, about 70 miles west of Denton, discovered too late that natural gas had migrated to its water well in 2014. A man was badly burned, as was his father and his 4-year-old daughter, in a flash fire. A methane cloud had gathered around the family’s water well and it ignited when the man opened the door to his wellhouse.
Escobar declined an interview with the Record-Chronicle. Grace said it took a while for them to understand how serious the situation was.
Grace had nosebleeds last fall that lasted about five minutes each time, she said.
“I’ve never had nosebleeds before, or since,” she said. But, she added she couldn’t be sure that the leaking gas was the cause.
She was glad to see the inspectors and the crews making repairs, but she remained concerned that the ground is sinking around the old water well, which was plugged in December.
During their first visit on Nov. 15, state inspectors visited Escobar’s water well and checked on nearby gas well sites along south Teasley Lane and Hickory Creek Road in Denton. Records show they visited well sites near the Kroger grocery store, another near Sprouts and another adjacent to Guyer High School.
They inspected the gas wellheads and equipment, including a simple gauge that shows pressure changes inside the well casing that could indicate a leak underground. The inspector’s reports showed troubling readings at both the wells by Guyer High School and the Meredith well, which is near Sprouts, railroad commission records show.
Inspectors ruled out a problem at the wells near Guyer High School, saying they didn’t read the pressure gauge correctly. Additional inspectors came out three days later with a special infrared camera and other equipment to learn more about the gas getting into the Escobar’s water well. They also took a water sample to learn more about characteristics of the gas in the water.
They turned their attention to the Meredith well, which is owned by Endeavor Energy Resources, based in Midland.
Cherl Prince, regulatory manager for Endeavor, said the railroad commission notified the company about the problem in November and its representatives immediately began to take corrective actions.
“Operations to remediate the issue were completed in late January 2017,” Prince wrote in an email. “Endeavor checks on its producing wells on a daily basis.”
State records showed the company reported a sharp drop in the amount of gas the Meredith well was producing in October, another possible signal of leaking gas. In addition, a company representative told state inspectors that the Meredith well was prone to pressure changes, according to state records.
The Record-Chronicle requested inspection records for the three gas wells nearest the Escobar water well from the beginning of the life of the well 15 years ago up to the present. Railroad commission officials said the agency no longer retains inspection records that are more than two years old.
Records showed inspectors visited the Meredith well three times in the two years prior to the leak, with the last visit in April 2016. Another Endeavor Energy well behind Kroger -- called the Forester well -- was inspected twice in the two years prior to the Escobar water well leak. The last inspection came in June 2016. The agency produced no records showing that the wells adjacent to Guyer High School, which sits an estimated half mile from Escobar's water well, had ever been inspected in the two years prior to the leak.
City records show that the city of Denton’s inspectors visit gas well sites a little more frequently, but city inspectors focus on other fire prevention conditions, such as paint, lightning arrestors and weed control.
Tony Ingraffea, a Cornell University engineering professor, told the Record-Chronicle that it is well-known that aging wells can develop problems; therefore they should be inspected more frequently.
Ingraffea said that aging Texas wells have another vulnerability. Unlike other states (or new federal rules following the Los Angeles' area's catastrophic leak at Aliso Canyon), Texas still allows drillers to line casings with a single layer of cement.
“The risk of leaks heightens with time in single-point-of-failure designs,” Ingraffea said.
Ken Banks, who was recently promoted from the city’s environmental services to oversee the city’s water and wastewater departments, said the railroad commission did not notify about the gas surfacing in Escobar's abandoned water well.
The Record-Chronicle requested documents related to the investigation from the North Texas Groundwater Conservation District. The district registers groundwater wells in Collin, Cooke and Denton Counties. The district withheld the records pending a ruling from Texas Attorney General Ken Paxton.
Property owners can’t drill new water wells within the city limits without proving it would be a financial hardship to hook up to the city's water system, Banks said. Meanwhile, the city tries to identify abandoned water wells inside the city limits and make sure they are properly plugged.
“We don’t want them [water wells] to act as a conduit to groundwater,” Banks said. “You don't want to have that open portal.”
PEGGY HEINKEL-WOLFE can be reached at 940-566-6881 and via Twitter at @phwolfeDRC.