(a) The definitions promulgated at 40 Code of Federal Regulations 60.281 shall apply to all sections within this undesignated head and are hereby incorporated by reference.
(b) Except as provided in §112.53 of this title (relating to Alternate Emissions Limitations), no person may cause, suffer, allow, or permit emissions of TRS from kraft pulp mills to exceed the following limits:
  (1) recovery furnaces:
    (A) old design (furnaces without membrane wall or welded wall construction or emission-control designed air systems): 20 parts per million (ppm) TRS, as hydrogen sulfide (H[sub]2[/sub]S) on a dry basis, corrected to 8.0% oxygen;
    (B) new design (furnaces with both membrane wall or welded wall construction and emission-control designed air systems: five ppm TRS, as (H[sub]2[/sub]S) on a dry basis, corrected to 8.0% oxygen;
    (C) cross recovery (furnaces with green liquor sulfidities in excess of 28% and liquor mixtures of more than seven weight percent of the total pulp solids from the neutral sulfite semichemical process): 25 ppm TRS, as H[sub]2[/sub]S on a dry basis, corrected to 10% oxygen;
  (2) digester system, multiple-effect evaporator system, or condensate stripper system: five ppm TRS, as H[sub]2[/sub]S on a dry basis, corrected to 8.0% oxygen, unless gases are burned in a combustion device, such as an incinerator or power boiler, for at least 0.5 second at 1,200 degrees Fahrenheit, a lime kiln, or a recovery furnace;
  (3) lime kiln: 20 ppm TRS, as H[sub]2[/sub]S on a dry basis, corrected to 10% oxygen; and
  (4) smelt dissolving tank: 0.033 lb/ton black liquor solids as H[sub]2[/sub]S (0.016 gram/kilogram black liquor solids as H[sub]2[/sub]S).
(c) Compliance with the emissions limitations in subsection (b) of this section or §112.53 of this title (relating to Alternate Emissions Limitations) shall be determined by reference Methods 16, 16A, or 16B (40 Code of Federal Regulations 60, Appendix A) or an equivalent measurement method approved by the executive director.

Source Note: The provisions of this §112.51 adopted to be effective July 14, 1989, 14 TexReg 3203.