November 06, 2003 Doug Deason ExxonMobil Chemical Engineering and Manufacturing Support

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

2. PROPRIETARY 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

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 • Orange 125 ppb ozone • Red 165 ppb ozone • Purple 205 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 Running Averages • Ozone Maximum Eight-Hour Running Averages • Ozone Graph of Five-Minute Data for the Day • Ozone Graph of Peaks • Ozone Graph of Net Ozone Production • Ozone Animation • Plume Animation • Plume Animation - Regional • Satellite Image Houston - True Color • Satellite Image Texas - True Color • 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. PROPRIETARY 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)

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 • Fugitives 48% Routine 17% SSM & Emission Events • Flares 30% Routine 73% SSM & Emission Events • Cooling Towers 7% routine 10% SSM and Emission Events • Polymer Vents 8% 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. TEXAQS: Texas Air Quality Study2000 • 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

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. Can Upset Releases Be Significant? 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

18. Are Upset Releases Significant? TEXAQS Reflects short term concentration elevation 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

19. Conclusion 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) TEXAQS