Analysis Links Pollutants with Barnett Shale Gas and Oil Production

Environmental Defense Fund today released an analysis that compared trends in air pollution data collected by the state with public records of oil and gas activity in the Barnett Shale and found a correlation between the ambient levels of common hydrocarbons and the amount of condensate produced by natural gas wells in Denton County.

A related analysis released today of state air pollution monitoring data between 2002 and 2008 found that the air in Denton county contained more non-methane hydrocarbons (including some potentially hazardous pollutants) than any of the other counties in the Dallas-Fort Worth area where such monitoring was conducted. 

Hydrocarbons include many chemicals found in natural gas and petroleum. Most are considered volatile organic compounds (VOCs), which contribute to the formation of ground-level ozone or smog. Environmentalists are also concerned because methane, a main component in natural gas, contributes to greenhouse gas emissions and climate change.

"EDF is not opposed to shale drilling for natural gas, a valuable national resource and cleaner transition fuel," said Ramón Alvarez, Ph.D., senior scientist who led the analyses. "We simply want to see production done in the most environmentally responsible way possible. The good news is that many emissions controls can actually increase profits for natural gas producers."

Results of these analyses come at a time when the oil and gas industry is drawing increased attention from the development of unconventional resources like the Barnett Shale, some of which are located near population centers. The New York Times reported last week about the challenge of persuading gas and oil producers to employ emission reduction measures that frequently pay for themselves. 

Numerous cost-effective ways exist to reduce emissions from oil and gas production. Most of these measures have paybacks of less than one year. "An environmental trifecta is within our reach," Alvarez said. "Oil and gas operators can use proven emissions controls to increase profits after short payback periods, while helping improve local air quality and minimizing climate change."

The oil and gas industry releases about 37 tons of VOC emissions per day in Denton County, which ranks second in the region behind Wise County's 42 tons per day. These emissions are substantial, nearly equal to a third of the 100 tons of VOC emissions produced daily from all of the cars and trucks in the nine-county DFW ozone nonattainment area.

Proposed recommendations by EDF include: expansion of VOC monitoring, especially in other Barnett Shale counties with significant condensate production (e.g., Wise, Hood, Parker); adoption of cost-effective oil and gas emissions controls, beginning with condensate tanks; and analyzing the effects of emissions in the Barnett Shale area on health and regional ozone levels.

Analyses are available via downloadable PDFs on the EDF website.