Clarification, July 21, 2023 at 10:17 a.m.: A previous version of this story said that companies that lose natural gas due to emissions events can still charge consumers for the lost gas. That portion of the story has been removed because those rules don’t apply to Targa, which does not sell natural gas for public consumption.
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As a record-breaking heat wave bore down in June, extreme temperatures triggered a series of failures in West Texas’ gas supply infrastructure that led to more than 300 tons of greenhouse gases being released into the atmosphere.
According to more than a dozen reports filed by gas pipeline operators with the Texas Commission on Environmental Quality, extreme heat caused compressor stations along gas pipelines to dial back or shut down in June, which caused dangerous pressure buildup inside the pipes. In response, operators released hundreds of tons of natural gas through emergency valves and shut down other compressors in the network.
In Reagan County, a rural Permian Basin county with about 3,360 residents, reported emissions were nine times higher than the June average for the prior six years, according to an analysis of self-reported industry emissions data to the state by the Environmental Integrity Project, an environmental nonprofit organization based in Washington, D.C.
That analysis followed an earlier report by Public Citizen, an environmental watchdog group in Texas, stating that 18 emission events — the term used for unexpected releases of airborne pollution — were attributed to extreme heat in the West Texas gas fields last month, including nine in Reagan County. Those emissions included 362 tons of natural gas, which is largely made up of the potent greenhouse gas methane.
“It is sadly ironic that the fossil fuel industry is seeing its equipment threatened by a situation it helped create,” Adrian Shelley, Texas director of Public Citizen, said in the report.
The heat-related releases were equivalent to the greenhouse gas emissions of more than 5,000 cars in one year. But they are a tiny fraction of the approximately 30 million tons of annual U.S. methane emissions estimated in recent years. Oil and gas systems are the largest single source of methane emissions, according to the EPA.
Baking temperatures like those Texas experienced last month are becoming increasingly common partly due to the warming effects of carbon emissions from fossil fuels. Texas has seen average temperatures climb during the past century, a Texas Tribune data analysis shows — especially in the state’s oil-rich west, which includes the Permian Basin.
This year, San Angelo broke a 63-year-old temperature record, recording a high of 114 degrees on June 20. In Reagan County, temperatures hit 108 degrees three times in one week before peaking at 111 on June 25.
The heat-related gas releases mostly happened in remote rural areas — Reagan County has fewer than three people per square mile on average. But the effects of rural pollution can spread far beyond West Texas, according to Laura Kate Bender, assistant vice president for the American Lung Association’s Healthy Air campaign.
“It often shows up many, many, many miles away from the source of the pollution that formed it,” Bender said. “The methane that is being emitted from these facilities is further driving climate change and the health harms that all of Texas is experiencing.”
“Extensive planning occurs”
Power generation often depends heavily on the weather. Ice storms can freeze wind turbines, cloudy skies can reduce the output of solar panels and extreme temperatures can cause problems with gas supply.
When Winter Storm Uri caused catastrophic grid failure in February 2021 — leaving millions of Texans without power or heat for days in freezing temperatures — gas system failures comprised about 27% of the unplanned outages.
One year later, the Texas Railroad Commission, which regulates the state’s oil and gas industry, approved new rules for certain gas supply chain facility operators, requiring them to prepare their equipment for extreme heat and freezing cold.
Todd Staples, president of the Texas Oil and Gas Association, said in a statement that “extensive planning occurs to prepare assets for hot or cold weather,” which was “part of industry’s continued commitment towards achieving lower emissions through operational efficiencies and contributing to the reliability of Texas’ power grid.”
He said hot-weather preparations can include insulation, equipment shelters, sunshades, wind walls, around-the-clock monitoring and backup power generation.
“It is amazing what this industry does to keep jobs flowing and governments functioning with the revenue it contributes, all while investing heavily to successfully minimize environmental impact,” Staples said, adding that Texas accounts for 26% of U.S. natural gas production.
Self-reported emission events
The reported emissions events in Reagan County included one release of 238,000 pounds of natural gas by Targa Resources on June 20. In its report to Texas regulators, the company wrote “high ambient temperature” had caused an increase in pressure, leading operators to let gas escape from mid-morning until after midnight the next day.
Targa, a Houston-based company valued at $17 billion, did not respond to multiple requests for comment.
The Environmental Integrity Project’s analysis of emissions in five Permian Basin counties — Reagan, Midland, Ector, Crane and Glasscock — for the past seven years found that the June 20 event was the largest single gas release in those counties for the month of June since 2017 — another year of record-breaking West Texas heat, when Targa released 253,000 pounds of propane and 108,000 pounds of butane due to high temperatures in Midland County.
Reported emissions for the five counties this year during June totaled 1,150 tons — the highest since 2020 and almost four times as high as June 2022. That figure includes large volumes of nongreenhouse gases like sulfur dioxide, nitrogen oxides and carbon monoxide. The heat was not cited as a factor for many of those emissions.
Targa reported more than a dozen instances of venting unburned gas because of heat. Other companies also reported smaller releases of emissions but said they flared, or burned, natural gas and other chemicals rather than releasing them directly into the atmosphere.
For example, on June 20, DCP Operating Company in Ector County reported burning almost 4,000 pounds of “acid gas” in its flare after system failures “caused by the automatic shutdown of the control panel from elevated temperatures.” The next day, WTG South Permian Midstream reported burning about 7,000 pounds of carbon monoxide, 2,600 pounds of nitrogen oxide and 1,200 pounds of volatile organic compounds, or VOCs, due to “high gas temperature in the sales line.”
DCP declined to comment for this story, and WTG did not respond to requests for comment.
Texas requires companies to self-report emissions events, but the reports are never independently verified. Shelley at Public Citizen doesn’t think Targa was the only West Texas gas operator facing widespread heat problems in June.
“I was fairly confident this was going on elsewhere, but just this one company reported,” Shelley said.
Targa has failed in the past to report emission events to the state.
In February, a European Space Agency satellite detected a large gas release from a Targa compressor that was not disclosed until Bloomberg News reported it to state authorities. Targa later told Bloomberg that 10 tons of gas were released.
Targa and its subsidiaries have more than 5,700 notices of violation on record with the TCEQ since 2015. In that time, the agency has fined Targa companies 34 times and the company was required to pay about $452,000, according to state records.
Laura Lopez, a spokesperson for the agency, said TCEQ reviews each emissions event to determine if it could have been preventable “and assesses whether or not operators took measures to minimize emissions.”
Sharon Wilson, an optical gas imaging thermographer with Oil Field Watch, said she has recorded many large emissions events in Texas that never appear in the TCEQ database.
“All the operator has to do is deny the event reached the reportable threshold. Since it’s all self-reported by their own calculations, no one disputes it,” she said.
High temperature affects gas compressors
Air temperature affects the pump stations that move gas through pipeline networks, according to Richard Kuprewicz, a career pipeline engineer who has testified to Congress as an expert witness on pipeline safety.
Because warm air holds less oxygen, it burns less efficiently in the gas-fired turbines that run pumps. When those pumps can’t move gas out of the pipeline as quickly as it is put in, the subsequent pressure buildup can cause an explosion.
“I have to chuckle when the operators feign surprise with high temperatures,” said Kuprewicz, who is president of the pipeline consultancy Accufacts Inc. “It doesn’t make a lot of sense to just vent gas to [the] atmosphere.”
At well sites, he said, gas can be redirected from the pipelines to flares, where it’s burned and enters the atmosphere as carbon dioxide. But in almost all of the cases reported by Targa, gas was released in raw form — a practice known as “venting” — through emergency relief valves on pipelines.
Unburned natural gas contains up to 95% methane — a greenhouse gas that traps 80 times more heat than carbon dioxide. It also contains scores of carcinogenic hydrocarbons like benzene, toluene, ethylbenzene and xylene.
“You don’t use relief valves as pressure regulators, especially if you’re venting methane,” Kuprewicz said. “It’s Texas and they can claim it’s not illegal, but it’s poor engineering practice.”
Many available technologies can reduce gas emissions during extreme heat, according to Bill Caram, executive director of the nonprofit watchdog group Pipeline Safety Trust.
Mobile compressor stations can empty pipelines into storage tanks instead of releasing gas into the air. Gas could be diverted to other parallel pipelines or cleared from downstream segments in anticipation of heat waves, Caram said.
However, he said, most operators have no financial incentive to minimize emissions.
“The end user ends up paying for the gas whether it gets delivered or not,” he said. “If it gets released in these emission events, operators still make money.”
That’s because federal and state rules on gas pricing allow operators to charge consumers for gas that is “lost and unaccounted for” due to leaks, accidents, damage or maintenance. The Texas Railroad Commission allows operators to report up to 5% of their total gas deliveries as “lost and unaccounted for.”
Virginia Palacios, executive director of energy policy watchdog Commission Shift, said allowing operators to charge for lost gas removes incentives for better maintenance and engineering.
“There’s an economic case to be made for the public on why utilities should not let their product escape to the air,” she said. “If you pay a gas bill, you pay for lost gas.”
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