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NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
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Poster 4: Texas Air Quality Study 2000 (TexAQS2000) Special Point Source Inventory Development
Jocelyn Mellberg, Gabriel Cantu, Ron Thomas, Jim Smith, Jim Neece
Texas Commission on Environmental Quality
During the past two years, the TCEQ staff prepared a special hourly inventory for point sources in the Houston and Beaumont areas. This data has been used to prepare the Mid-Course Reviews of the Houston/Galveston area´s State Implementation Plan (both Phase I and Phase II). For the Texas portion of the point source emission inventory, data from the 2000 TCEQ´s point source database (PSDB) has been used for modeling Houston ozone episode. First, the inventories were supplemented with hourly data from the Environmental Protection Agency´s acid rain database. In addition, the 2000 inventory was supplemented with data obtained during the TexAQS2000 special inventory. Episode-day and hourspecific point source emissions data were collected from August 15, 2000 through September 15, 2000. These data were obtained by surveying the largest industrial sources of VOC and NOx in the Houston and Beaumont areas to account for specific operating conditions, upsets, start-ups, and shut-downs during the TexAQS2000. TCEQ contacted 83 companies in HGB and BPA. Of these companies, and 74 companies provided data. Respondents to the survey were expected to account for a large proportion of the VOC and NOx point source emissions in the nonattainment areas. In the HGB area, companies that responded to the survey accounted for approximately 50% of the Ozone Season Daily (OSD) NOx emissions and 70% of the OSD VOC emissions. And in the BPA area, respondents accounted for 60% of OSD NOx emissions and 70% of the OSDVOC emissions. Many companies supplied daily and even hourly chemical speciation profiles as part of the survey. This data has been used to develop the CB-IV and SAPRC speciation profiles used in CAMx. This talk will describe the results of the special inventory and how those results were incorporated into the Texas point source modeling inventory.