Modifications, additions, or relocations of equipment (excluding add-on controls) used for semiconductor manufacturing operations that result in the addition, increase, or substitution of an air contaminant are permitted by rule provided the following conditions of this section are satisfied.     
       (1) The following is a list of definitions for this section.                (A) Permitted air contaminants--The individual chemical compounds represented in the latest permit or permit amendment application approved by the executive director.                 (B) Ground Level Contaminant (GLC                   1                  )(max) new--The maximum hourly off-property GLC resulting from the new emission rate of air contaminant 1.                 (C) GLC                   1                  (receptor) new--The maximum hourly off-property GLC at the sensitive receptor with the highest possible impacts resulting from the new emission rate of air contaminant 1.                 (D) GLC                   2                  (max)--The maximum hourly off-property GLC resulting from the emission rate of air contaminant 2.                 (E) GLC                   2                  (receptor)--The maximum hourly off-property GLC at the sensitive receptor with the highest possible impacts resulting from the emission rate of air contaminant 2.                 (F) ESL                   1                  --The 30-minute Effects Screening Level (ESL) published in the commission's ESL list dated April 10, 1995, for air contaminant 1.                 (G) ESL                   2                  --The 30-minute ESL published in the commission's ESL list dated April 10, 1995, for air contaminant 2.        
       (2) New emissions or an emission increase of any air contaminant less than 0.04 pounds per hour  (sitewide) are exempt from all conditions of this section except paragraphs (3), (11), and (l2) of this section.      
       (3) A permit has been issued by the commission for at least one emission source owned by the person using this section on the same property for which this section is being claimed.      
       (4) The facility's baseline GLCs of the permitted air contaminants have been determined using air dispersion modeling or other methods.      
       (5) New emission points are not authorized by this section.      
       (6) There will be no change in method of control for any air contaminants as represented in the latest permit or permit amendment application approved by the executive director.      
       (7) Increases of a permitted air contaminant shall meet all of the following criteria:                (A) GLC                   1                  (max)new ≤ 2ESL                   1                  ;                 (B) GLC                   1                  (receptor)new ≤ ESL                   1                  .        
       (8) Additions of a non-permitted air contaminant, substitutions of a non-permitted air contaminant for a permitted air contaminant, and substitutions of one permitted air contaminant for another permitted air contaminant shall meet all of the following criteria:                (A) GLC                   2                  (max)new ≤ 2ESL                   2                  ;                 (B) GLC                   2                  (receptor)new ≤ ESL                   2                  .        
       (9) If the commission ESL list dated April 10, 1995, does not include the air contaminant to be added or substituted, the permittee must use an ESL derived by the commission's Toxicology and Risk Assessment Division. The ESL shall be obtained in writing prior to the use of the new substance.      
       (10) The cumulative net annual emission increases of the following categories of air contaminants from multiple uses of this section shall not exceed the following values:                (A) particulate matter--five tons per year (tpy);                 (B) volatile organic compounds (VOCs)--15 tpy;                 (C) non-VOCs--five tpy;                 (D) acids/bases--ten tpy;                 (E) any other air contaminant--five tpy;                 (F) total of all emission increases--25 tpy.        
       (11) The applicable ground-level concentration limits in Chapters 111, 112, and 113 of this title  (relating to Control of Air Pollution from Visible Emissions and Particulate Matter; Sulfur Compounds; and Toxic Materials) shall not be exceeded.      
       (12) Within 30 days of use of this section, the permittee shall maintain documentation that demonstrates all applicable conditions of this section were satisfied. The documentation shall be made available to the commission upon request.      
     Source Note:        The provisions of this §106.225 adopted to be effective March 14, 1997, 22 TexReg 2439; amended to be effective September 4, 2000, 25 TexReg 8653