Major industries in Texas that released 500 million pounds of pollutants into the air during maintenance and malfunctions were penalized by the state less than 3 percent of the time, according to environmental groups.

The Environmental Integrity Project and Environment Texas released a report Friday documenting pollution that occurs when petroleum refineries, chemical plants and other industrial sites undergo maintenance or breakdowns. The groups looked at air emissions across Texas from 2011 to 2016 using data from the Texas Commission on Environmental Quality.

They found that during that time, the TCEQ fined operators $13,501,340. That adds up to only 3 cents per pound of pollution released, said Ilan Levin, the Environmental Integrity Project’s associate director.

“These industrial polluters have no incentive to upgrade their equipment or hire more workers,” Levin said. “Lax enforcement means it pays to pollute.”

In an emailed statement, TCEQ officials disputed the idea that the agency allows industries to release “excess” amounts of air pollution. The agency is required by law to “evaluate emissions events that exceed a reportable quantity,” and it “requires facilities to minimize emission from maintenance activities and upset events,” the statement said.

In 2016 alone, the TCEQ logged 3,720 such emission events, the report states. TCEQ’s Region 13, centered in San Antonio, had 90 that released nearly 1.8 million pounds of pollution. The region came in fourth in the state after Midland, Houston and Beaumont-Port Arthur.

Emissions of hydrocarbon gases and volatile organic compounds can form harmful chemicals such as ozone when exposed to sunlight, said Arch “Chip” Carson, a doctor who practices occupational and environmental medicine with UTHealth School of Public Health in Houston.

“They chemically react with almost anything they come in contact with,” he said. “If they’re inhaled into the body, they cause irritation and damage to lung tissue.”

San Antonio’s top emitters in 2016 for maintenance and malfunction events were slightly different from those in other regions. While in areas such as Houston and Corpus Christi, the top emitters were refineries and chemical plants, the sources in San Antonio were pipelines and oil production sites.

A natural gas transmission line in Atascosa County under the name TexStar Field Services was the top emitter in 2016 in the San Antonio area, according to the report.

TCEQ data show that pipeline as being operated by Regency Energy Partners, which merged with Dallas-based Energy Transfer Partners in 2015, according to a news release.

On March 3 last year, the pipeline had a rupture in Atascosa County, according to a TCEQ report. Gas that escaped through the leak was burned off in a field flare, depressurizing the line and allowing workers to repair it.

From 5 a.m. to 7 a.m. that day, an estimated 77,502 pounds of volatile organic compounds, 7,578 pounds of sulfur dioxide and 4,197 pounds of hydrogen sulfide escaped from the line, according to TCEQ data.

Asked to respond to the report, Energy Transfer Partners said in an email: “We operate and maintain our pipelines with safety in mind. The safety of our employees, the safety of the environment and the safety of the communities in which we have assets is our top priority.”

The report also mentioned four oil production sites operated by Cabot Oil & Gas Corp. near Charlotte in Atascosa County.

The facilities normally send excess gas collected during crude oil production to a nearby plant operated by Southcross Energy, Cabot spokesman George Stark said in an email.

In February 2016, an explosion that killed two workers shut down the Southcross facility in Frio County, according to TCEQ and news reports.

Cabot then began burning excess gas in flares at the four sites for nearly two months, releasing an estimated nearly 70,000 pounds of sulfur dioxide, nitrogen oxides and volatile organic compounds from one flare alone, according to the TCEQ. Two of the four reported use of flares at other times after shutdowns at the Southcross site.

“Cabot operates in full compliance with its permits,” Stark’s email said. “If the (Southcross) facility is shut down for maintenance, we comply with the state regulations applicable to our facilities.”

Asked how the TCEQ should enforce incidents like this, Levin said TCEQ staff should investigate the source of the problem.

“Our review of the TCEQ reports shows that it’s not all that difficult to identify the root cause, and when the root cause is an avoidable or foreseeable breakdown, that’s who bears the responsibility,” he said in an email.

The report also recommends that the TCEQ do more air monitoring and make better notifications to the public during “upset” events that disrupt multiple oil and gas facilities.

bgibbons@express-news.net