Final Report: Texas Joint Center for Air Quality

EPA Grant Number: X832317
Center: Texas Joint Center for Air Quality
Center Director: Hitchcock, David
Title: Texas Joint Center for Air Quality
Investigators: Hitchcock, David , Allen, David T.
Institution: The University of Texas at Austin
EPA Project Officer: Chung, Serena
Project Period: September 1, 2005 through August 31, 2008
Project Amount: $969,300
RFA: Targeted Research Center (2004) Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research


The Joint Center work has included several components: the Transportation and Air Quality Forum (TAQF), Texas Air Quality Study II (TexAQS II) tasks, and six research subawards.  Joint Center activities have included formation of an Advisory Committee, interaction with regional air quality decision processes in target regions (Houston and Dallas/Fort Worth), and communications with partner organizations.
Over the reporting period, the TAQF focused on identifying and reviewing transportation/air quality options that were included in SIP considerations in the Houston and DFW regions. The objective has been to create an evaluative database of options that could be more readily assessed than current regional decision processes allow. This led to a secondary focus for incorporating promising control measures that may fail to meet SIP criteria, but would directional achieve air quality benefits.  In the course of this examination, TAQF also assembled and examined transportation/air quality computer models that might be suited to wider use in regional decision processes, the primary focus being those that might be amenable to on-line applications by community decision makers.  
The primary conceptual difficulty identified by this project is the lack of consistent or comparable quantitative and qualitative information on transportation/air quality options. Over 1,000 transportation/air quality options were identified in the course of this project, which have been part of the target regions’ decision processes.  More than 50 evaluative variables were identified in seeking to develop a database structure that could be used to analyze these options; most of these variables have not be quantified in the research and studies examined.  And in most instances, the variables identified were not comparable across options. 
The challenges identified in this project suggest that developing a more comprehensive analytical decision process is substantially more than could be accomplished in one initiative, although the need for a more structured and comprehensive system remains.  Staff has met throughout the project with regional transportation/air quality staff and other researchers to consider these challenges. Toward this end, staff participated in mobile source research discussions with regional, state, and others involved in target city transportation issues.  This included involvement with the Texas Environmental Research Consortium (TERC), which is specifically focused on air quality research and policies in the Houston and Dallas/Ft. Worth nonattainment areas. 
On outreach activities with decision makers, the Joint Center has worked with various activities and stakeholders. The Center participated in outreach activities to communicate with stakeholders in the Houston and DFW regions.  These activities included the Montgomery County Transportation Task Force, the regional Commute Solutions programs (such as NuRide), and various regional non-motorized initiatives (biking/pedestrian) with air quality objectives.  During 2007 and 2008, the Joint Center worked with stakeholders to toward creation of the Advanced Technology Truck Coalition of Texas (ATTCoT), with an aim of further inclusion of hybrid truck technologies as an air quality/transportation measure.  Various workshop initiatives were pursued with EPA Region 6, Texas Transportation Institute, and the regional COGs to further outreach on transportation/air quality issues pertinent to TAQF.

Summary/Accomplishments (Outputs/Outcomes):

Status of Subawards
Five of the six subaward projects are complete.  Final reporting from the Texas A&M Galveston project was prevented due to Hurricane Ike in August 2008.  Joint Center staff visited project sites including Texas A&M/TTI, Texas A&M Galveston emission testing, and Lamar University at various points in the projects. 
  • The TexAQS II project (University of Texas at Austin – UT):  Complete.  This project contributed to field studies and analysis carried out under the Texas Air Quality Study II program that involved a wide range of researchers in a field campaign for the Houston and east Texas region. 
  • MOBILE 6 High Speed Emission Rates (Texas Transportation Institute, Texas A&M – TTI): Complete.  This project developed drive cycles and high speed emission factors for use in MOBILE6 that had not been available for vehicles traveling more than 65 mph. 
  • Marine Vessel Use of Bio-Fuel (Texas A&M Galveston – TAMUG):  Project tasks complete; awaiting final report; staff moved to College Station due to hurricane damage.  This project identified detailed marine vessel movements and measured emissions associated with the use of biodiesel in marine engines. 
  • Photocatalytic Coating on Road Pavements/Structures for NOx Abatement (Lamar University): Complete.  This project tested the effects of catalytic materials in paving on NOx levels. 
  • Effects of Atmospheric Aging on Ozone, Secondary Aerosol and Particulate Matter and Air Toxics (University of North Carolina – Chapel Hill):  Complete.  This project compared various air quality effects of B100/99 biodiesel. 
  • Assessment of CO and NOx Emission Estimates from MOBILE6 with Ambient Concentrations from Texas Roadways  (The University of Texas at Austin):  Complete.  This project compared CO/NOx ratios for field measurements and mobile source modeling.
(2) Change in Key Personnel
No change in key personnel.
(3) Discussion of Expenditures
Expenditures have been slower than planned. Project expenditures through August 31, 2007 amounted to $607,095 or 63% of the total award.  The TAQF portion is $307,680 with $299,415 expended for subawards.  No significant variations from the current budget have occurred. The project is 70% complete through August 31, 2007. No budget revisions are needed.
(4) Quality Assurance Statement
Quality assurance requirements have been implemented, as described in HARC’s QAPP. The TAQF tasks have not involved data collection or testing.  Environmental measurements and data generation have been conducted by subawardees in accordance with their submitted QAPPs and their organization’s quality assurance requirements.
(5) Results to Date
The TAQF has conducted reviews of SIP transportation control measure analyses in target regions (Houston and Dallas/Ft. Worth areas). These reviews found a lack of quantitative and qualitative measures for most of the decision variables identified. This supports the need for alternative methods or alternative processes for informing regional processes for transportation/air quality decision-making.
A major TAQF objective was to develop an alternative region-based method (called regional translation), but the challenge of analyzing hundreds of options without comparative information presented a substantial barrier for any data driven method, particularly if it is intended to be region specific. Several publicly available computer analysis models were identified for potential use in helping to meet this challenge, and are linked in Joint Center web information.  
The Joint Center website was revised in 2008.  It contains a comprehensive list of emissions and air quality models along with links to other pertinent reference sources.  Because of a lack of quantitative and qualitative data for control measures, the options database only lists control measures under their respective categories, it does not include a searchable component that would allow users to search measures based on a certain metric. 
Work on a regional translation methodology resulted in a white paper on the SIP process and regional translation that was submitted for publication.  This paper has not been accepted to date, but is being submitted to other publications in the future.  To assess the issues surrounding the current SIP process, Joint Center staff met with decision makers from the Houston-Galveston Area Council (H-GAC), the North Central Texas Council of Governments (NCTCOG), the Texas Transportation Institute (TTI), and city officials from Dallas and Houston.  These discussions increased interest in addressing the issues identified in this project.  Most shared opinions and ideas with regard to the critical evaluative problems associated with the SIP processes and requisite improvements.  Responses from other regions (such as WASHCOG) have indicated similar problems, but no readily applicable changes have been identified.  Responses from white paper reviews indicate that some do not experience the problems identified in the Texas target regions.  Provisions such as “bundling” and “emerging measures” that have been developed in recent years are responsive to these issues.  Texas SIP processes, air quality planning, and regulatory oversight may be sufficiently different from other states that the problems identified in this project are unique to Texas target regions. 
Joint Center staff worked extensively with the H-GAC RAQPQ (Regional Air Quality Planning Committee) Policy Subcommittee and the Transportation Control Measure/Voluntary Mobile Emissions Reduction Program (TCMs/VMEPs) Working Group to help identify and prioritize transportation control road measures and projects for inclusion in the SIP, including options identified in the Joint Center process. 
Joint Center staff continued to interact with stakeholders and staff involved in Texas air quality research through TERC processes, including a Science Advisory Committee, a Technical Advisory Committee, and an Advisory Council.  Additionally, Joint Center staff has participated in technology development projects that are part of the transportation/air quality approach in the target regions.  TERC is a nonprofit organization receiving research funding from the State of Texas for air quality research and technology development.   Joint Center staff involvement has included input on transportation and mobile source options from Joint Center research. 
HARC, in conjunction with the Joint Center, launched the Advanced Technology Truck Coalition of Texas (ATTCoT).  The coalition includes end users and technology providers aiming to accelerate deployment of fuel efficient and clean technology in Texas.  The objectives are:
  • Leverage combined purchasing power of the coalition members
  • Pooling resources for demonstration program and early technology adoption
  • Pursuit of State and Federal grants to offset incremental cost of technology
  • Conferences to disseminate important technology information to members and the public
  • Information sharing between members and technology providers
HARC is working with EPA Region 6 for a hybrid truck and advanced technology conference in 2009. 
The Joint Center and H-GAC worked with stakeholders to organize and sponsor a workshop on TTI’s Mobile Source Emission Reduction Strategies (MOSERS) guide.  Over 25 policy makers and stakeholders attended the workshop.  The MOSERS guide provides a possible alternative approach to regional translation and it is being examined for further inclusion in SIP related control measure evaluation.  Similar control measures catalogs have been prepared, but none have been compiled into flexible evaluative tools (e.g., searchable databases). 
Subaward Results to Date
·         TexAQS II: The University of Texas, as part of the overall Texas Air Quality Study II, conducted seasonal modeling on transport of pollutants, made improvements to emissions inventories (fine particulates primarily), and helped assimilate satellite data into air quality modeling. 
·         MOBILE 6 High Speed Emission Rates:  The study produced a wide range of results including drive cycles, measured emissions rates using PEMS equipment, modeled emissions rates using MOBILE6, regression models for estimating emissions, and expansion curves to extend MOBILE6 rates to speeds above 65 mph. The findings from the study enable transportation and air quality planners to more reliably assess impacts associated with high-speed operations already existing on freeways and tollways as well as facilities scheduled for inclusion in metropolitan transportation plans (MTPs) in the near future. 
·         Marine Vessel Use of Bio-Fuel: Detailed marine vessel movement data were collected and compiled from the U.S. Coast Guard records. Biodiesel emissions tests were conducted using B20 in a marine engine.  Due to the closure and relocation (to College Station) of the Texas A&M Galveston campus as a result of Hurricane Ike, delivery of the project’s final report has been delayed. 
·         Photocatalytic Coating on Road Pavements/Structures: Lamar University researchers have constructed a catalyst-coated concrete photoreactor (CCP) setup consisting of a catalyst-coated cement concrete slab and a light source fixed to a wooden casing for testing NOx removal. NOx is introduced into this setup for testing. NO conversion in the CCP reached 90% within 5 minutes and increased to stay above that level thereafter. NO2 concentration profiles show the intermediate stage of NO oxidation. NO conversion increases with residence time in the CCP. The NO conversion time was found to be insensitive to the inlet concentration after 5 minutes. The research did find that higher relative humidity leads to a lower conversion, most likely due to the competitive adsorption between water and NO. 
·         MOBILE6 CO and NOx emissions over/under estimation:  Despite its frequent and broad application, there remains a continuing need to evaluate the performance of the MOBILE model against near roadway measurements. Further analysis of the Texas Roadway Study data was performed in this study to evaluate the MOBILE6 emissions model.  Eight separate time periods with a range of traffic volumes were selected from the continuous monitoring at stationary trailers. Hourly emissions factors for CO and NOx generated by MOBILE6 and measured hour-specific meteorological data were used as inputs in CALINE4, a roadway plume dispersion model.  Predicted CO/NOx values were higher than observed CO/NOx during seven out of the eight time periods. Predicted CO/NOx ratios for all but one of these seven runs were within a factor of three of observed ratios. During one time period, MOBILE6 over predicted the CO/NOx ratio by a factor of 4.1. The average of the eight ratios of predicted CO/NOx to observed CO/NOx (ratio of ratios) in this study was 1.96. A similar evaluation should be conducted using the next generation mobile source emissions model, MOVES, as it becomes available.
·         Effects of Atmospheric Aging on Ozone, Secondary Aerosol and Particulate Matter and Air Toxics:  A Ford-350 Diesel pickup equipped with dual fuel tanks was fueled with either conventional diesel or 100% ASTM grade biodiesel produced from waste vegetable oil (WVO) to produce exhaust used to conduct experiments in the UNC environmental smog chamber. The exhaust mixtures in the chamber were allowed to photochemically react in the presence of real sunlight for a full day.  In addition, in vitro toxicological exposures were conducted to measure the relative toxicity of these air mixtures, as measured by cell death and inflammatory response.  Comparisons of WVO and conventional diesel fuel emissions show that the truck, when fueled with WVO, produces less particle mass, CO, NOx, and formaldehyde (as well as other carbonyls) than when fueled with diesel fuel.  The photochemical reactivity of the exhaust test mixtures is significantly reduced when WVO biodiesel exhaust replaces conventional diesel in air, both alone and mixed with an urban-like VOC mixture. The truck engine fueled with WVO biodiesel and conventional diesel fuel produces a similar Particle Number Concentration, but the WVO produces a smaller Particle Mass Concentration since the fresh WVO exhaust particles are initially smaller compared to conventional diesel exhaust.  Particulate emissions of the WVO biodiesel, in terms of mass, are roughly half that of the conventional diesel fuel. Toxicological evidence suggests that photochemical aging increases the toxicity of particles of both fuels, but the diesel exhaust becomes significantly more toxic causing twice the cell death compared to the aged WVO biodiesel exhaust.


Joint Center activities continue under a separate award to the University of Houston.  The future activities focus on selected transportation measures that could be incorporated into State Implementation Plans. 

Journal Articles: 3 Displayed | Download in RIS Format

Other center views: All 11 publications 3 publications in selected types All 3 journal articles
Type Citation Sub Project Document Sources
Journal Article Feldman MS, Howard T, McDonald-Buller E, Mullins G, Allen DT, Webb A, Kimura Y. Applications of satellite remote sensing data for estimating dry deposition in eastern Texas. Atmospheric Environment 2007;41(35):7562-7576. X832317 (Final)
  • Full-text: Science Direct
  • Abstract: Science Direct
  • Other: Science Direct PDF
  • Journal Article Simon H, Allen DT, Wittig AE. Fine particulate matter emissions inventories: comparisons of emissions estimates with observations from recent field programs. Journal of the Air & Waste Management Association 2008;58(2):320-343. X832317 (Final)
  • Abstract from PubMed
  • Journal Article Webster M, Nam J, Kimura Y, Jeffries H, Vizuete W, Allen DT. The effect of variability in industrial emissions on ozone formation in Houston, Texas. Atmospheric Environment 2007;41(40):9580-9593. X832317 (Final)
  • Full-text: Science Direct
  • Abstract: Science Direct
  • Other: Science Direct PDF
  • Supplemental Keywords:

    RFA, Air, climate change, Air Pollution Effects, Atmosphere

    Progress and Final Reports:

    Original Abstract
  • 2006 Progress Report
  • 2007 Progress Report