An early report from an ongoing Fort Worth air quality study has been corrected to show that volatile organic compounds (VOC) detected at one of the monitored sites are much lower than stated more than two weeks ago.
Eastern Research Group (ERG) Inc., which has been contracted by the city to conduct the study of Barnett Shale area emissions, said it erred in calculating VOCs at the test site located at 2299 Mercado Drive. The firm's Natural Gas Air Quality Study -- Interim Report should have said VOC emissions were 0.353 tons per year rather than 103.78 tons per year, ERG told the city. The revised figure is well under air permit thresholds.
The erroneous figure reported earlier had raised some concern, but it is now said to have been due to a "calculation error."
Gas well sites producing less than 25 tons per year of VOCs would qualify for the permit by rule (PBR) designation, Texas' lowest level of air permit. "This corrected result puts the site well within the limits for the PBR. Gas well sites producing more than 25 tons per year of VOC emissions must apply for the next level of air permit, the standard permit," Michael Gange, assistant director of transportation and public works, told Fort Worth Mayor Michael Moncrief in a memo.
"To be clear, all data within the Interim Report is preliminary and as such may be subject to change."
Another monitored site -- 11398 West Freeway -- was also shown to have preliminary VOC emissions exceeding 25 tons per year. No change has been made to the early data from this site.
"The final report will contain field data, laboratory data, emission calculations and other detailed point source emission data to thoroughly document the process, provide accurate calculations and provide comprehensive conclusions about air quality impacts from gas drilling and production," Gange said. "ERG is currently processing all the data from the almost 400 point source emission site visits.
"Throughout this unprecedented process the gas well operators have worked with ERG to allow open and unannounced access to their operations."
The final ERG report is due to the city on June 30.
Another report was recently delivered to the board of the Fort Worth Independent School District that, among other things, recommended one-mile setbacks of natural gas wells from school property. However, an industry advocate active in the Barnett Shale called the report a "hoax" and said it was based on faulty research (see Shale Daily, Feb. 24).