1. (a) Baseline amounts. A baseline amount must be established for major stationary sources or Section 185 Accounts that begin operating during or after the baseline year. The baseline amount must use the first full year of operation as a major source and be the lower of:

   1. (1) total amount of baseline emissions; or
   2. (2) total annual emissions allowed under applicable authorizations, including emissions from maintenance, startup, and shutdown activities. Emissions from pending authorizations with administratively complete applications as of the last day of the full first calendar year of operation may be included in the total annual emissions allowed under authorizations.
2. (b) Adjustments. The baseline amount must be adjusted downward to exclude any emissions that exceeded an emissions limit for rules or regulations in effect by the last day of the one-year period used to determine the baseline amount.
3. (c) Emissions units. Baseline amounts must include all emissions units located at the major stationary source as of the last day of the one-year period used to determine the baseline amount. When control or ownership of emission units changes during the calendar year, the emissions from those emission units will be attributed to the major stationary source with control or ownership of the emission unit on the last day of the one-year period used to determine the baseline amount.
4. (d) Calculations. A baseline amount, reported in units of tons per year, must be calculated separately for each pollutant, volatile organic compounds and/or nitrogen oxides for which the source meets the major source applicability requirements of §101.701 of this title (relating to Applicability).
5. (e) Compliance schedule. Within 90 calendar days of completing the first full year operating as a major stationary source, the major stationary source or Section 185 Account must submit to the executive director a report establishing the baseline amount on a form published by the executive director.
6. (f) Review. Where the baseline amount does not align with information recorded in either the emissions inventory database or the air permitting data systems, the executive director may direct that the baseline amount be based on the lower of reported emissions under §101.10 of this title (relating to Emissions Inventory Requirements) or total annual authorized emissions. After review, the baseline amount will be fixed and not change except as allowed under this subchapter.

Source Note:The provisions of this §101.706 adopted to be effective November 13, 2025, 50 TexReg 7293.