Have you been keeping up with recent discussions regarding the Ozone Nonattainment Areas in Texas? Spirit Has!
As you may know, the Houston-Galveston-Brazoria (HGB) and Dallas-Fort Worth (DFW) ozone nonattainment areas are currently classified as “serious” under the 2008 ozone standard and “marginal” under the 2015 ozone standard. San Antonio/Bexar County is also “marginal” under the 2015 ozone standard (this area is attainment under the 2008 ozone standard). Another important piece of information is that 2021 is an attainment year for both standards.
One of the confusing aspects of ozone nonattainment is that there are actually two ozone standards in effect at the same time: The 2008 ozone standard and the 2015 ozone standard. Potentially adding to the confusion, the counties designated as nonattainment under the 2008 ozone standard are not identical to the counties designated as nonattainment under the 2015 ozone standard within the HGB and DFW nonattainment areas. There are also times when an area is attainment under the 2008 ozone standard but nonattainment under the 2015 ozone standard; San Antonio/Bexar County is an example of this scenario.
Let’s take a look at where the nonattainment areas currently stand:
- 2008 standard (75 ppb): The HGB area is currently classified as serious nonattainment under the 2008 ozone standard. Based on monitoring data, HGB is eligible to request (and the TCEQ has requested) an ozone classification extension; however, the extension is not automatic and must be approved by the EPA for it to take place. If the EPA does not grant an extension, it is anticipated that HGB will be “bumped-up” from the serious classification to the severe classification in early 2022.
- Likewise, the DFW area is also currently classified as serious nonattainment under the 2008 ozone standard; however, DFW does not appear to be eligible for an extension, and it is anticipated that DFW will be “bumped-up” from the serious to the severe classification in early 2022 as well.
- 2015 standard (70 ppb): HGB, DFW, and San Antonio/Bexar County are all currently classified as marginal nonattainment under the 2015 ozone standard. Based on monitoring data, it is anticipated that these areas will be “bumped-up” from marginal to moderate ozone nonattainment (also in early 2022 timeframe).
So, why is this important? Well, let’s look at the different impacts that a bump-up would have, focusing on the 2008 ozone standard because it has a larger, and potentially more immediate, impact on a company’s authorization options and permitting strategy:
- The definition of a major source will decrease from 50 tons/year (of either VOC and/or NOx) to 25 tons/year.
- Sources (sites) located in the nonattainment area that have PTEs (or authorized emission rates) between 25 tons/year and 50 tons/year will become major sources once a classification bump-up rule becomes effective.
After the effective date of a bump-up rule, all of the nonattainment new source review (NNSR) applicability analysis requirements for the “new” ozone major sources come into play.
- If a new source is at or above the nonattainment major source threshold of 25 tons/year of NOx and/or VOC, NNSR will apply;
- If a project’s net emissions increase is greater than, or equal to, the nonattainment major modification threshold of 25 tons/year of either NOx and/or VOC, NNSR will apply; and,
- If NNSR is triggered, LAER and offsets (at a 1.3:1 ratio) will be applicable to the project.
This can be very important if an existing site is located in the HGB or DFW 2008 ozone standard nonattainment areas and has authorized emission rates between 25 and 50 tons/year (of either VOC and/or NOx).
Does this sound confusing? Are you concerned about future permitting/authorization requirements in your area? Do you have the data necessary to support a NNSR analysis? If you are unsure of the answers to any of these questions, feel free to contact our air quality subject matter experts and we’ll be happy to help you work through these complex requirements!
