1. November 06, 2003 Doug Deason ExxonMobil Chemical Engineering and Manufacturing Support Houston Area Ozone Air Quality Overview of Tools, Techniques, Communications and Improvements to Better Understand Ozone

2. Agenda items Tools/techniques being used to analyze exceedances and VOC data –Use of back trajectory analysis –New / improved tools for meteorology measurement Ozone Action Days Forecast & Warning systems Modeling to simulate ozone spikes Improvements to Emission Reporting New Regulations in the works? Industry & TCEQ cooperation including specific projects Upcoming relevant Technical Seminars in TX PROPRIETARY

3. Tools/techniques being used Measurements and Methods Extensive monitoring locations –Monitors with ozone, NOx & speciated VOC –Map follows –Owned by City of Houston, TCEQ, and Houston Regional Monitoring (HRM) SSM & Emission Event Reporting analysis –On the web reporting of SSM & Emission Events since early 2003 Episode Specific Data –TCEQ Monitoring Operations Group for selected episodes –HRM publishes summary information for all ozone exceedances –Special analyses by TCEQ & Industry for selected exceedances –[Examples follow ]

5. Ozone Action Days Forecast System Ozone Forecast - Ozone Conducive Meteorology triggers –Accuracy 1994-2002 is ~ 83%. –Key forecast criteria include Wind speed between 10a.m.-4p.m. <7 mph Temperature above 74 degrees F Satellite pictures indicate low cloud cover Day before estimate of incoming regional ozone TCEQ Monitoring Operations Owns

6. Ozone Warning System Ozone Warning –Initiated in 2000 to issue warnings to the public based on measured levels of ozone –Initial warning system specifically targets high ozone levels in the Houston-Galveston-Brazoria, Dallas-Fort Worth, and San Antonio areas Measured high 1 hour ozone triggers –Orange125 ppb ozone –Red165 ppb ozone –Purple205 ppb ozone TCEQ Tools are non-proprietary and data is available from National Weather Service & others TCEQ Monitoring Operations Owns

7. Ozone Episode Followup HRM Members receive compilation of data for each ozone exceedance episode –Tabulation of key data for each monitor that exceeded –Summary data (Example attached) –Back trajectory plots –NOAA Satellite Image & NOAA & NWS Forecast of Fronts, Pressure, and Weather Exploring improving shared analysis tools to better automate data visualization and facilitate analysis. Exploring improved to do specific event analysis

8. Ozone Episode Followup TCEQ Monitoring Operations posts data for selected Ozone Episodes  Ozone Maximum One-Hour Clock Averages Ozone Maximum One-Hour Clock Averages  Ozone Maximum One-Hour Running Averages Ozone Maximum One-Hour Running Averages  Ozone Maximum Eight-Hour Running Averages Ozone Maximum Eight-Hour Running Averages  Ozone Graph of Five-Minute Data for the Day Ozone Graph of Five-Minute Data for the Day  Ozone Graph of Peaks Ozone Graph of Peaks  Ozone Graph of Net Ozone Production Ozone Graph of Net Ozone Production  Ozone Animation Ozone Animation  Plume Animation Plume Animation  Plume Animation - Regional Plume Animation - Regional  Satellite Image Houston - True Color Satellite Image Houston - True Color  Satellite Image Texas - True Color Satellite Image Texas - True Color  Satellite Animation - GOES12 Satellite Animation - GOES12

9. Modeling to simulate ozone spikes Urban Airshed Model Grid size and coarseness of emissions representation inhibit ability to replicate ozone spikes –Can’t generate enough ozone “Box” Model Lack of all dynamic physical processes produces too much ozone in a “static box” Developmental work underway at Univ. of Texas & Univ. of North Carolina is attempting to iteratively couple these two models to better simulate ozone spikes

10. Industry & TCEQ cooperation Specific Projects 2001-Emission Inventory Verification project –Is the annual inventory submission being done well with existing tools? Voluntary Episodic Release Reduction Initiative Integrated Science Committee –Jointly identify key research projects to fund Emission Inventory –HRVOC Inventory Source Analysis (to determine source focus) –Emission Point Type Classification Improvement For 2000 Episode Modeling For improving future annual submissions Shared monitoring (HRM results provided to TCEQ) PROPRIETARY

11. Improvements to Emission Reporting Annual data reported and used for modeling with supplemental “special inventory” for modeling episode Areas for improvement include –More speciation of VOC’s –Better classification of Emission Point Types to correspond to regulated equipment types –Improved monitoring for major sources of HRVOC emissions Major HRVOC Emission Sources in the Houston area are –Fugitives48% Routine17% SSM & Emission Events –Flares30% Routine 73% SSM & Emission Events –Cooling Towers7% routine 10% SSM and Emission Events –Polymer Vents8% routine 0% SSM and Emission Events

12. New Regulations in the works? Lowered HRVOC Reportable Quantities to 100 # in 9/2001 Improving Monitoring for Flares & Cooling Towers by YE05 Flare Metering & Composition Analysis in place Continuous cooling tower leak detection/speciation Improving Fugitives Monitoring [1H2004] Adds new components to periodic Method 21 monitoring Mid Course Review 1-hour SIP Update - 2004 Will address Account Cap Emission Limits for HRVOC – Sources include Flares, Vents, Cooling Towers New Emission Limits become Effective in 2006 HGA SIP Revision in 2004

13. Choosing a Focus Significant data and analysis has lead Houston to Focus on specific substances, emission sources, and types of emissions Analysis of 2000 TEXAQS Data –Led to understanding of significance of HRVOC Emission Inventory Analysis to identify key sources –Led to focus on fugitives, flares, cooling towers, and vents Understanding of Emission Rate Variability –Led to focus on understanding & reducing emissions from SSM & Emission Events

14. A $20 million one month air quality sampling study was done in August and Sept. 2000 Some of the slides that follow hilight some of the preliminary science observations, findings, learnings, and questions These data and learnings were unavailable for the Dec. 2000 SIP Data processing and learning are ongoing TEXAQS: Texas Air Quality Study 2000 TEXAQS

15. TxAQS Preliminary Results Ozone appears to be produced more efficiently by ship channel emissions than from urban area emissions –Ship Channel yield more than twice the urban yield –12 - 15 molecules of ozone produced per molecule of NOx –Highest yield the investigators have seen so far The rate of ozone formation from industrial emissions in the HG area is faster than observed in other areas of the US –Production rates 50 to 100 ppb /hour observed at both surface monitors and aircraft measurements Ozone yield Reactivity

16. Focus on Highly Reactive VOC Control Focus on key compounds and emission type –Ethylene, propylene, and butadiene have high reactivity and very high yield –Houston has a unique high density of industrial sources of these compounds –Houston has many episodic releases of these high reactivity and high yield compounds Ozone Forming Potential - Incremental Ozone Yield

17. A few key points: Short term releases of very Highly Reactive / High Yield VOC can result in rapid and high levels of ozone formation (THOE’s) over a very localized area (which can be carried by air elsewhere). Large releases of less reactive or lower yield VOC’s can additively increase typical ozone In the Houston area, both types occur Can Upset Releases Be Significant?

18. Are Upset Releases Significant? Upset or other episodic emissions may have caused or contributed to ozone NAAQS exceedances on perhaps 6 to 10, of 21 spike exceedance days in 2000 Reflects short term concentration elevation TEXAQS

19. Keys to Houston progress include TCEQ and Industrial collaboration to identify potential problems and develop solutions. New science was a key eye-opener (TEXAQS) Willingness to question what we thought we knew Open communications Trust building over time Focused objectives (can’t work on everything at once) Conclusion TEXAQS