Oil and gas companies in West Texas released hundreds of tons of toxic gases into the air last week as a record-breaking heatwave drove pressure inside pipelines and compressors to dangerously high levels. 

One company, Houston-based Targa Resources, alone released more than half a million  pounds of gas into the air during at least 17 reported events over a seven-day period, according to records filed with the Texas Commission on Environmental Quality. 

In one instance, the $17 billion company vented 238,000 pounds of gas when facilities in its pipeline network dialed back operations “to prevent them from shutting down due to high ambient temperature.” In another, it released 168,000 pounds “to prevent compressor units from overheating due to high ambient temperature.”

“These are just huge, major release events,” said Wilma Subra, an environmental chemist and MacArthur fellow in Louisiana, who reviewed the data for Inside Climate News. “That gas contains a whole host of chemicals that cause cancer and chronic diseases.”

A searing heat wave in June broke temperature records across Texas. Because gas expands as it warms, the weather caused sharp pressure increases inside the pipeline systems that carry West Texas gas to refineries, power plants and other customers. In order to avoid explosions, operators release gas into the air, including the potent greenhouse gas methane, which traps 80 times more heat than carbon dioxide. Methane also contributes to ground-level ozone pollution, which can cause breathing problems and other health issues. 

“Emissions are always way worse when it’s hot,” said Sharon Wilson, an optical gas thermographer who monitors oilfield emissions in Texas with Oilfield Witness. “The oil and gas industry cannot survive the extreme weather they create.”

Most of the heat-related emissions were reported as “volatile organic compounds,” the complex chemicals, vapors at room temperature, that make up petroleum gas. It’s mostly methane, but also includes cancer-causing chemicals like benzene, xylene and ethylbenzene.

“These events add up to a lot of toxic gases,” Wilson said. “They are just using our air for a dump.”

Heat-Related Emissions 

The heat-related emissions were reported by operators to the TCEQ and accessed via the agency’s online database.

In one West Texas incident on June 20, Targa reported: “Extreme high ambient air temperature caused issues out in the field. To protect the Rocker B Compressor Station from overpressure conditions and for safety reasons, inlet gas was routed to the Pressure Relief Valve.”

In another incident on June 25, Targa reported: “Multiple units shut down due to the ambient air temperature, causing pressure on the field pipeline system to increase… and inlet gas was vented to the atmosphere.”

Although Targa reported the most and the largest gas releases due to heat, it wasn’t the only operator to do so. 

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.”

On June 21, WTG South Permian Midstream burned about 7,000 pounds of carbon monoxide, 2,600 pounds of nitrogen oxide and 1,200 pounds of VOCs due to “high gas temperature in the sales line.” On June 26 the same company burned  off 5,200 pounds of carbon monoxide and 2,000 pounds of nitrogen oxide because of “restricted flow due to high discharge gas temperature causing the recompressor shutdown.”

Initial reports of emissions quantities are only estimates, said TCEQ spokesperson Victoria Cann, and may be revised up to two weeks after the event. After that, the agency will determine whether to enforce environmental law. 

TCEQ typically allows companies that emit excess pollutants to cite an “affirmative defense” and argue that the emissions were beyond their control because of unforeseeable circumstances. The agency says it “carefully considers the facts” in deciding whether excess emissions were unavoidable.

Cann said TCEQ rules “require operators to be accountable for good operation and maintenance practices, and those rules do not extend an affirmative defense to any activity or event that could have been foreseen and avoided or planned for.”

“TCEQ may pursue enforcement actions when appropriate against regulated entities which may include the assessment of a penalty,” Cann said. 

A 2017 report by the Environmental Integrity Project and Environment Texas found that TCEQ penalizes only about three percent of unauthorized emissions events each year. 

A 2023 report by the Environmental Integrity Project identified 21,769 instances of unauthorized pollution in Texas between 2016 and 2022, but found that “only one half of one percent of these incidents did the state use its legal authority to require the companies to analyze the cause of the problem and take concrete action to avoid these pollution releases in the future.”

“The TCEQ has been unwilling to require industry to do better,” that report said. 

Vulnerable Gas Infrastructure 

Luke Metzger, executive director of the nonprofit Environment Texas, said that state authorities should require sufficient insulation on oil and gas facilities to avoid temperature-related pollution. 

“Many companies avoid making health and safety investments to their facilities to reduce costs and maximize profits, leaving Texans to hold the bag of pollution and blackouts,” he said. 

Metzger also noted that about 10 gigawatts of power generation was unavailable to Texas’ electrical grid during the heatwave, driven largely by interruptions of gas supply. 

“These facilities not only pollute during extreme temperatures, they often fail to deliver gas to the power plants which need it,” he said. “This demonstrates the vulnerability of our gas infrastructure to extreme weather, whether it’s hot or cold.”

Gas supply also failed in 2021 during Winter Storm Uri, which caused catastrophic grid failure in Texas, according to Virginia Palacios, executive director of Commission Shift, a watchdog group for Texas’ oilfield regulator, the Texas Railroad Commission. 

Nonetheless, she said, lawmakers in Texas’ recent legislative session focused on subsidies for the gas sector in order to boost grid resilience. 

“That goal was misguided because natural gas infrastructure is subject to failure during extreme weather,” Palacios said. “Too many Texas legislators are blindly pushing natural gas as the ultimate fuel without following the data.”

Targa Resources, one of the largest midstream companies in the Permian Basin, did not respond to multiple requests for comment. 

According to Andrew Wheat, research director for Texans for Public Justice, the company has made campaign contributions to oil regulators on the Texas Railroad Commission, who have also traded the company’s stock. 

“Our state oil and gas agency is captured by the companies it is supposed to oversee,” Wheat said.  “These conflicts of interest lead to long term sustained negligence by companies who know that there is no state agency that will penalize them for breaking the rules.”

The Railroad Commission did not respond to a request for comment.