Applications of the Mobile Ambient Air Monitoring Laboratory in Addressing Air Quality Issues for the City of Houston

1. Applications of the Mobile Ambient Air Monitoring Laboratory in Addressing Air Quality Issues for the City of Houston Mobile Laboratory Program Team: James Rhubottom, Jr., Dr. Youjun Qin, Dr. Peter Chen Program Manager: Dr. Wei-Yeong Wang 2009 NAQC -05Mar09

2. The case for improving Houston’s air monitoring options Photograph - Heidi Bethel

3. Houston Area Air Pollution Factors • Meteorology/Topography – Houston/Galveston area • Below the jet stream, weather systems are strongly influenced by Gulf of Mexico and Galveston Bay • “Houston Heat Pump” - Dr. John W. Nielsen-Gammon • 30 miles to Gulf of Mexico, daily sea-breeze • Large scale urban environment traps heat, results in large temperature gradient with surrounding agricultural landscape • Acts as a heat pump, deflects naturally occurring land-breeze • Pulls air cells over pollution sources back into city • Results in stagnant and humid air masses that may last for weeks

4. Houston Area Air Toxics Sources • Area Sources • Gas stations, dry cleaners, construction equipment, outdoor grills, landscaping equipment • Daily byproducts from 5 million Houston/Galveston area residents • Point Sources • 140 petrochemical plants in Harris County • Two of the four largest refineries in the world • 400 chemical plants in the Houston/Galveston are • Greatest concentration of petrochemical plants in the United States

5. 22,000 of the 79,000 permitted emission points in the State of Texas lie along the Houston Ship Channel

6. Mobile Ambient Air Monitoring Laboratory (MAAML) Funding provided by the U.S. EPA and the Houston Endowment, Inc.

7. MAAML – Instrumentation

8. MAAML – Process Schematic Sampling Tower ThermalDesorber Gas Chromatograph Meteorological Tower/GPS CapillaryColumn Dean’sSwitch MassSpectrometer Fuel/Carrier Gas Supply FlameIonization Detector PLOT Column DataLogger BAQC Server Modem

9. Program Metrics • Over 1820 hours of field sampling • 1548 hours of field samples collected • Data capture rate of 86% during 24-hour sampling periods (not including quality control samples) • Collected samples from five separate locations surrounding the two-plant complex as defined in the original grant proposal (primary upwind and downwind sites) as well as deployments in around several plants and industrial facilities in the Greater Houston Area • ~8% of samples contained 1,3-butadiene at concentrations greater than 1.0 ppbv

10. Stages of MAAML Deployment • Phase 1: Determination of Capabilities • Phase 2: Response to VOC Complaints • Phase 3: Addition to Analytical Scope

11. Phases of MAAML Deployment Phase 1: Demonstration of Capabilities • Identification and characterization of emissions events • Initial focus on 1,3-butadiene • Later addition of benzene • Data analysis and back trajectories in source determination

12. Phase 1 - Initial MAAML Monitoring Locations

13. Phase 1: Case Study - Emissions Event • On 01Oct07, the MAAML recorded elevated 1,3-butadiene levels over a three hour interval. • AIM atmospheric modeling indicated via back trajectory that the likely emissions source appeared to come from one of the two plants. • BAQC staff conducted investigations associated with the MAAML data. • Concurrent with the MAAML emissions detection, fence-line monitors in one of the plants also recorded 1,3-butadiene emissions.

14. Phase 1: Case Study - Emissions Event • The Milby Park auto-GC and the MAAML detected elevated levels of 1,3-butadiene, while the Cesar Chavez auto-GC did not.

15. Phase 1: 1,3-BD Back Trajectory Model Back trajectory for 01Oct07 1,3-butadiene release

16. Phase 1: 1,3-BD Forward Trajectory Model Forward trajectory for 01Oct07 1,3-butadiene release

17. Phase 1: Case Study - Emissions Event • Back trajectories generated by the MAAML’s AIM software can provide not only which facility most likely generated the source of a detected emissions event but also can, based upon the severity of the release and prevailing wind conditions indicate a specific area inside the plant as the most likely location of the emissions event.

18. Phase 1 – 1,3-BD Back Trajectory Model Back trajectory for 20Sep07 1,3-butadiene release from the second plant

19. Phase 1: Case Study - Emissions Event • During this phase of the MLP, the MAAML acted as an extra fixed monitor to extend the current air monitoring network. • In this role, the MAAML, with its onboard GC/MS instrumentation, provides accurate and confirmed air toxics concentration data faster than previously available. • It also showed ways to maximize MAAML capabilities. • Adding a 51 compound TO-15 calibration standard would enhance emissions fingerprinting and provide more data for investigators. • Combining upwind canister sampling with downwind MAAML monitoring would strengthen case for designating the targeted facility as the source of the emissions event.

20. Phases of MAAML Deployment Phase 2: Response to Citizen VOC Complaints • Identification and characterization of unknown VOCs • Determination and evaluation of VOC source • Data analysis and back trajectories in source determination

21. Phase 2: Case Study – VOC Complaints • During December 2008, BAQC fielded a number of citizen complaints emanating from a nearby two-plant industrial complex with a history of emission events. • MAAML data revealed two unknown peaks at 21.95 and 29.10 minutes, which, upon library comparison, were tentatively identified as 2,4,4-trimethylpentene (TMP) and 4-vinyl-1-cyclohexene (VCH). • A review of plant process streams revealed VCH and TMP concentrations corresponding to collected MAAML data.

22. Phase 2: Case Study – VOC Complaints Back trajectory at 0130 31Dec08

23. Phase 2: Case Study – VOC Complaints Note: VCH and TMP concentrations are estimates only. Concentration versus time for six compounds (30-31Dec08)

24. Phase 2: Case Study – VOC Complaints • During this phase of the MLP, the MAAML acted as a resource to address citizens’ air quality complaints. • In this role, the MAAML, with its onboard GC/MS instrumentation, stood as an independent verifier of the VOC source. • The 51 compound TO-15 calibration standard aided in bracketing the TICs, a useful aid in VOC characterization. • In addition, the MAAML provided a reasonable estimate of the potential hazards associated with the emissions event. • Lastly, the MAAML showed its versatility in performing as a mobile monitor in the field while serving as a fixed base laboratory for the analysis of canister samples collected by BAQC Environmental Investigators.

25. Phases of MAAML Deployment Phase 3: Addition to Analytical Scope • Inclusion of Ozone and PM monitors to MAAML • Target monitoring locations with regard to population segments most vulnerable to these pollutants • Leveraging internal and external resources in support of ongoing monitoring initiatives • Establishing opportunities for collaborations with public health and academic institutions to determine how best to incorporate even further the MAAML’s capabilities as regards the Mayor’s initiatives for the improvement of Houston’s air quality.

26. Phase 3: Addition to Analytical Scope • Supporting DIAL – LIDAR project • BAQC grant from U.S. EPA to evaluate DIAL as a new monitoring technology for benzene and other air toxics in the United States • Supplemental air monitoring • Sitting the MAAML in locations lacking quality monitoring data • Community environmental investigations • Sampling at sites community organizations see as potential health hazards

27. Phase 3: Addition to Analytical Scope • Field sampling analysis • Analyzing field samples collected by BAQC staff as part of their ongoing investigations • Community outreach • Informing the public about MAAML data through community presentations and a dedicated website to help achieve Mayor White’s initiatives for improving Houston’s air quality

28. Summary • The MAAML has shown its ability for identifying and characterizing a variety of point source emissions, providing useful, high-quality data to aid in plant investigations. • The techniques and strategies initially used in MAAML field deployments for 1,3-butadiene have applicability for other air toxics, most notably benzene, as well as compounds not classified as air toxics. • The MAAML can be used as tool to promote and improve community awareness while also investigating the presence of air toxics in ambient air samples. • The MAAML’s capabilities extend far beyond the initial project guidelines as delineated in the EPA and HEI grants that funded the MAAML.

29. Acknowledgements • U.S. EPA, Region 6 • U.S. EPA • Texas Commission on Environmental Quality • Houston Endowment, Inc. • Houston Advanced Research Center (HARC) • Providence Engineering, LLP • Quantum Analytics • Agilent Technologies • Met One Instruments, Inc.

30. References and Personnel • EPA 2003 Toxic Release Inventory (TRI) Report • Texas Air Quality Study (2000) • “A Closer Look at Air Pollution in Houston: Identifying Priority Health Risks,” Mayor’s Task Force on the Health Effects of Air Pollution, 2006 • “The Control of Air Toxics: Toxicology Motivation and Houston Implications,” Clemens, Flatt, Fraser, Hamilton, Ledvina, Mathur, Tamhane, Ward; Houston Endowment Inc., 2006 • “Houston Heat Pump: Modulation of Atmospheric Sciences,” John W. Nielsen-Gammon, The Texas A&M University, College Station, Texas • TCEQ, 2005 Emissions Inventory Arturo J. Blanco, MPA – Bureau Chief, BAQC Dr. Wei-Yeong Wang – MLP Program Manager/ Chief, Technical Services, BAQC James Rhubottom, Jr. – MLP Operations Leader and Chemist Dr. Youjun Qin – MLP Chemist Dr. Peter Chen – MLP Chemist

31. MLP Personnel Contacts Dr. Wei-Yeong Wang: wy.wang@cityofhouston.net James Rhubottom: james.rhubottom@cityofhouston.net Dr. Youjun Qin – youjun.qin@cityofhouston.net Dr. Peter Chen – peter.chen@cityofhouston.net

32. Questions?