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

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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

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The case for improving Houstons air monitoring
options Photograph - Heidi Bethel
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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

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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

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22,000 of the 79,000 permitted emission points in
the State of Texas lie along the Houston Ship
Channel
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Mobile Ambient Air Monitoring Laboratory (MAAML)
Funding provided by the U.S. EPA and the Houston
Endowment, Inc.
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MAAML Instrumentation
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MAAML Process Schematic
Sampling Tower
Thermal Desorber
Gas Chromatograph
Meteorological Tower/GPS
Capillary Column
Deans Switch
Mass Spectrometer
Fuel/Carrier Gas Supply
Flame Ionization Detector
PLOT Column
Data Logger
Modem
Server
BAQC
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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

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Stages of MAAML Deployment

• Phase 1 Determination of Capabilities
• Phase 2 Response to VOC Complaints
• Phase 3 Addition to Analytical Scope

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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

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Phase 1 - Initial MAAML Monitoring Locations
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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.

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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.

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Phase 1 1,3-BD Back Trajectory Model
Back trajectory for 01Oct07 1,3-butadiene release
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Phase 1 1,3-BD Forward Trajectory Model
Forward trajectory for 01Oct07 1,3-butadiene
release
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Phase 1 Case Study - Emissions Event

• Back trajectories generated by the MAAMLs 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.

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

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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

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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.

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Phase 2 Case Study VOC Complaints
Back trajectory at 0130 31Dec08
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Phase 2 Case Study VOC Complaints
Note VCH and TMP concentrations are estimates
only. Concentration versus time for six compounds
(30-31Dec08)
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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.

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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 MAAMLs capabilities as regards the Mayors
  initiatives for the improvement of Houstons air
  quality.

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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

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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 Whites initiatives for
  improving Houstons air quality

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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 MAAMLs capabilities extend far beyond the
  initial project guidelines as delineated in the
  EPA and HEI grants that funded the MAAML.

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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.

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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, Mayors 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 AM
  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

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MLP Personnel Contacts

• Dr. Wei-Yeong Wang wy.wang_at_cityofhouston.net
• James Rhubottom james.rhubottom_at_cityofhouston.net
  
• Dr. Youjun Qin youjun.qin_at_cityofhouston.net
• Dr. Peter Chen peter.chen_at_cityofhouston.net

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Questions?