Tony Walker, REM DFW Regional Director Texas Commission on Environmental Quality Texas Commission on Environmental Quality – DFW Region Office

Barnett Shale Study Phase 1: August 24-28, 2009 Phase 2: October 9-16, 2009 Phase 3: November 16-20, 2009 * 2007 Initial Study - North Texas Flyover Texas Commission on Environmental Quality – DFW Region Office

Barnett Shale Study 94 Monitoring Sites GasFindIR Toxic Vapor Analyzers Summa Canisters Texas Commission on Environmental Quality – DFW Region Office

TCEQ Monitoring Review Infrared Gas-Imaging Camera (IR Camera) Infrared Gas-Imaging Camera (IR Camera) –Allows us to see hydrocarbon emissions that we cant see with the bare eye Texas Commission on Environmental Quality – DFW Regional Office

Barnett Shale Study Of the 94 sites monitored, TCEQ documented that only two sites had benzene levels that demanded immediate action TCEQ documented that 19 additional sites may require action by facility operators Texas Commission on Environmental Quality – DFW Region Office

Barnett Shale Study Two sites exceeded both short-term and long-term ESL - Repairs have been completed & confirmed by TCEQ Initial monitoring: Targa (site 8) – 1,100 ppb (compressor station) Devon (site 7) – 15,000 ppb (five feet from well) Texas Commission on Environmental Quality – DFW Region Office

What is an Effect Screening Level (ESL)? ESLs are based on data concerning health effects, the potential for odors to be a nuisance, effects on vegetation, and corrosive effects. They are not ambient air standards. If predicted or measured airborne levels of a constituent do not exceed the screening level, adverse health or welfare effects are not expected. If ambient levels of constituents in air exceed the screening levels, it does not necessarily indicate a problem but rather triggers a review in more depth. ESLs are based on data concerning health effects, the potential for odors to be a nuisance, effects on vegetation, and corrosive effects. They are not ambient air standards. If predicted or measured airborne levels of a constituent do not exceed the screening level, adverse health or welfare effects are not expected. If ambient levels of constituents in air exceed the screening levels, it does not necessarily indicate a problem but rather triggers a review in more depth. The ESL for benzene is: The ESL for benzene is: Short term = 180 ppb Long term = 1.4 ppb Texas Commission on Environmental Quality – DFW Region Office

Barnett Shale Study TCEQ conducted verification monitoring 1/18/10 Post repair benzene levels: Targa (site 8) ppb Devon (site 7) ppb Texas Commission on Environmental Quality – DFW Region Office

Whats Next? Install new stationary monitors - DISH and Eagle Mountain Additional targeted mobile monitoring – ground and air-based monitoring Continue complaint response process (12 hour response) Continue routine / reconnaissance investigations Texas Commission on Environmental Quality – DFW Region Office

Conclusion Repairs have been completed at the two sites where significant levels of benzene were documented (benzene is now at background levels) Repairs are in progress at sites where elevated levels of benzene were detected TCEQ will continue to investigate and direct facilities to make the necessary repairs and verify repairs achieve desired results TCEQ will continue to monitor to ensure emerging issues are addressed Texas Commission on Environmental Quality – DFW Region Office

Contacts & Additional Resources TCEQ DFW Regional Office: TCEQ DFW Regional Office: File a complaint at OR online at: File a complaint at OR online at: TCEQ Barnett Shale Information Webpage: TCEQ Barnett Shale Information Webpage: nettshale/bshale-main nettshale/bshale-main Texas Commission on Environmental Quality – DFW Region Office