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Study: Industry Data Shows Hazardous Air Pollutants Are ‘Ubiquitous’ In The Natural Gas Transmission System; More Justification For Robust Leak Prevention Programs

In the first peer-reviewed study of EPA-designated Hazardous Air Pollutants in the natural gas transmission system, researchers from the Lawrence Berkeley National Lab and the University of California reviewed industry data and found HAPs were “ubiquitous throughout the gas transmission system, including pipelines, LNG facilities and storage facilities.”

In addition, “associated emissions sources such as flash gas and condensate vapor were reported to contain extremely high concentrations of HAPs.”

The study-- Hazardous Air Pollutants In Transmission Pipeline Natural Gas: An Analytic Assessment-- was accepted for publication in Environmental Research Letters September 16.

The authors of the study based their results on industry-disclosed Hazardous Air Pollutants data submitted to the Federal Energy Regulatory Commission as part of natural gas infrastructure applications between 2017-2020.

Although the HAP data is not required to be submitted by FERC, 49 percent of the approved natural gas expansion projects disclosed natural gas HAP data, according to the authors.

The Hazardous Air Pollutants reported by industry included-- hexane, benzene, toluene, ethylbenzene, xylenes, 2,2,4-trimethylpentane and hydrogen sulfide.

Up until now, the main justification for initiatives to control leaks from oil and gas infrastructure from the wells through the distribution system has been because those leaks contain methane-- a potent greenhouse gas-- and volatile organic compounds-- a precursor to the formation of ozone air pollution.

This includes new regulations in Pennsylvania. Read more here.

The Department of Environmental Protection estimates leaks from conventional oil and gas infrastructure facilities account for 80 percent of the methane emissions and 76 percent of the VOC emissions from oil and gas facilities because little thought and effort has gone into controlling those emissions by the industry. Read more here.

The unconventional shale gas infrastructure accounts for the remainder.

This new study also notes natural gas pipelines and infrastructure release natural gas during both routine operations and off-normal loss of containment events (e.g., blowdowns and blowouts), which we now know not only contains methane, but also Hazardous Air Pollutants and other chemicals.

The authors also pointed to recent research on the natural gas distribution system in Boston suggesting the “ubiquitous” nature of Hazardous Air Pollutants in the transmission system “delivers HAPs into the distribution system where they can be released into the indoor and outdoor environment, in close proximity to substantial numbers of people.”

“The identification of hexane and BTEX in natural gas from the production sector, distribution sector, and now the identification of hexane and BTEX in the transmission sector suggests that HAPs may travel throughout the entire natural gas supply chain and result in HAP exposures at various points along that supply chain.”

A study released earlier in September by the American Lung Association looked at the health impacts of fuel-burning appliances in the home-- like natural gas appliances-- and found they can have a dramatic impact on health. Read more here.

The contaminants looked at in that study were primarily carbon monoxide, nitrogen oxides, particulate matter, formaldehyde, but not HAPS. Read more here.

The authors of this new study do caution-- “no regulatory limits exist for HAPs present in natural gas” so direct comparisons to regulatory limits for HAPs in the ambient air are “not applicable as exposures to pure hydrocarbon streams are unlikely and releases would adhere to dispersion and dilution dynamics.”

“Nonetheless, for natural gas, reported HAP concentrations were higher than U.S. EPA Reference Concentration limits but generally under other health-based limits with the exception of benzene.

“For condensate vapor and flash gas, reported HAP concentrations were one or two orders of magnitude higher than various health-based limits including occupational short-term exposure limits for BTEX compounds.”

The study authors conclude-- “This study strongly suggests that routine natural gas releases and loss of containment events in the natural gas transmission sector are not only an issue pertinent to flammability, explosions and climate forcing from methane, but also a concern for air quality degradation and potential human exposure to elevated concentrations of HAPs, including toxic and/or carcinogenic volatile organic compounds, hydrogen sulfide, radon, and mercury.”

This new study provides more justification for putting in place an effective oil and gas leak detection and repair system throughout the entire natural gas distribution system.

Click Here for a copy of the research study.

(Photo: Methane leaks at Pennsylvania pipeline compressor station.)

Related Articles - Leak Controls:

-- IRRC Unanimously Approves Part I Of Final Reg. Reducing VOC/Methane Emissions From Unconventional Shale Gas Facilities; DEP Moves To Avoid Federal Highway Funding Sanctions

-- Republicans On House Committee Disapprove Final Reg. To Reduce VOC/Methane Emissions From Unconventional Oil & Gas Facilities Risking $500 Million In Federal Highway Funds

Related Articles This Week:

-- Penn State Research Links Groundwater Contamination To Areas Of Unconventional Shale Gas And Conventional Oil And Gas Drilling [PaEN]

-- DEP Tells Citizens Advisory Council Road Dumping Conventional Oil & Gas Wastewater Still Does Not Meet Residual Waste Regulations; Remains Illegal [PaEN]

-- U.S. Dept. Of Interior Notified DEP A Republican Bill Allowed To Become Law In July May Block Funding For New Federal Conventional Oil & Gas Well Plugging Program [PaEN]

-- DEP Finalizing First Bid Packages To Plug 249 Conventional Oil & Gas Wells Under New Federal Taxpayer Funded Well Plugging Program [PaEN]

-- House Committee Fails To Address $70 Million In Penalties On Natural Gas Pipelines Or Real Concerns Of People Living Near Gas Production & Distribution Facilities [PaEN]

-- PA Environmental Council: Clean Hydrogen & Carbon Capture Can Be Part Of A Comprehensive Decarbonization Strategy: Responsibly Deployed With Environmental Integrity, Accountability And Equity [PaEN]