See the latest EHS federal and state regulatory updates due to COVID-19


If your site is located in a Texas ozone nonattainment area and emits more than 10 tons per year (tpy) of volatile organic compounds (VOC) or 25 tpy of nitrogen dioxide (NOx) in a calendar year, your site is required to submit an Annual Emissions Inventory Questionnaire (EIQ).  Many sites have been doing this for years, but there are numerous sites authorized under De Minimis authorizations, Permit By Rules (PBRs), or minor New Source Review (NSR) permits that may not be aware of this applicability threshold.

There are several applicability thresholds set by the Texas Commission of Environmental Quality (TCEQ) that require submittal of an EIQ as noted below:

  • A site is considered a major source in a nonattainment area
  • A site is located in an ozone nonattainment area that emits 10 tpy of VOC or 25 tpy of NOx
  • A site emits or has the potential to emit (PTE) 100 tpy of any contaminant
  • A site is a major source of hazardous air pollutants (HAP), e.g., emits or has the PTE 10 tpy of any single HAP or 25 tpy of all combined HAPs
  • Any site that is subject to TCEQ's special inventories as outlined in the TCEQ's Emissions Inventory Guidance

If your site was not familiar with the nonattainment thresholds of 10 / 25 for VOC and NOx, you are not alone. Please note, even if you have not received a formal letter from the TCEQ requesting the submittal of an EIQ, if your site meets one of the above criteria, an EIQ is required. All initial EIQs are due March 31 following the calendar year, e.g., March 31, 2010 for the reporting of 2009 actual emissions. If you need assistance with your EIQ or have any questions regarding the threshold for applicability, don't hesitate calling one of Trinity's Texas team at 512-514-6600 (Austin), 361-883-1668 (Corpus Christi), 972-661-8100 (Dallas) or 713-552-1371 (Houston).