A new and important study of the air quality in the Barnett Shale was released by Houston-based ToxStrategies, Inc. This study, published in the peer-reviewed “Science of The Total Environment,” is the first large-scale evaluation based on extensive measurements of ambient air in a shale gas producing area. The investigators concluded that Barnett Shale gas production activities have not resulted in community-wide exposures to chemicals at levels that would pose health concerns. With the high density of active natural gas wells in the Barnett Shale region, these findings may be useful for understanding potential health risks in other shale play regions.

The investigators reviewed more than 4.6 million air concentration values that were generated by the extensive air monitoring system that has been operated by the Texas Commission on Environmental Quality (TCEQ) for the last 12 years. When the measured concentrations were compared to federal and state health-based air comparison values (HBACVs), the investigators found that none of the 4.6 million air concentration values exceeded applicable acute HBACVs. The findings have undergone independent, scientific peer-review before publication.

Since the air samples were collected over more than a decade, a range of shale gas activities was captured, including drilling, hydraulic fracturing and production. Consistent with numerous other air studies that have been conducted in the Barnett Shale region, these results indicate that shale gas operations are not impacting community-wide ambient air concentrations of VOCs (volatile organic compounds). This is especially important given the exponential increase in the number of wells over the last decade.

The value of the TCEQ’s data is described in the report:   

• The air monitoring network that is currently in operation in the Barnett Shale area is extensive – including seven monitors in six different locations that represent areas where the general public could potentially be exposed, different types of monitors including a number of automated gas chromatographs (autoGCs) that run continuously, and the measurement of more than 100 chemicals at each monitor. 
• The air monitors in the Barnett Shale have been in place since the early 2000s, making it possible to look at the relationship between changes in air concentrations across time relative to the exponential increase in shale gas wells in the region. 
• The air-monitoring network has monitoring sites in areas of both richer (“wet”) and dry gas regions of the Barnett Shale. This is important as air emissions of VOCs are generally greater in rich/richer (wet) gas areas; therefore the diversity of monitor locations within the Barnett Shale provides data representing the spectrum of air emissions from different shale gas regions. (p. 833).

The Barnett Shale Energy Education Council provided the funding for the research in order to utilize the extensive set of air monitoring data that TCEQ has gathered.