Regulatory Text: 
Section 112.1.  Definitions.

(Approved by EPA 08/30/93 (58 FR 45457) at 52.2270(c)(76) effective 10/29/93.)

Unless specifically defined in Section 382.003 of the Texas Clean Air Act (TCAA) or in the rules of the Board, the terms used by the Board have the meanings commonly ascribed to them in the field of air pollution control.  In addition to the terms which are defined by the TCAA, the following terms, when used in this chapter, shall have the following meanings, unless the context clearly indicates otherwise.


   Continuous emissions monitoring - sampling, analyzing, and recording at least one measurement of sulfur dioxide concentration in each 15-minute period from the effluent of each affected process or the emission control system serving each affected process.


   Effective stack height - a value in feet calculated by the following equation:

He = H + 0.083 * Ve * De [1.5 + 0.82 * ((Te - 550) / Te) * De]

Where:
He = Effective stack height in feet
H = Physical stack height above ground level in feet
Ve = Stack exit velocity in feet per second 
De = Stack exit inside diameter in feet
Te = Stack exit temperature in degrees Rankine


   In-stack concentration - the concentration of a pollutant inside the stack measured in parts per million by volume (ppmv) referenced at 0% stack gas oxygen on a dry basis averaged over a period of one hour with oxygen determined by the equation:

Ci = 20.9 * Cx / (20.9 - Co)

Where:
Ci = in-stack pollutant concentration corrected for 0% oxygen in ppmv
20.9 = % of oxygen in the air
Cx = measured pollutant concentration
Co = % dry oxygen measured in the stack


   Short-stack reduction factor - the factor by which the allowable emission rate must be multiplied if the source has an effective stack height less than the standard effective stack height.  The short-stack reduction factor is calculated by the following equation:

   Short-stack reduction factor = (He/Hs)^2

Where:
He = Effective stack height 
Hs = Standard effective stack height


   Secondary metal recovery facility - a facility which recovers metals and alloys from new and used scrap and dross.  It does not mean assembling, sorting, and breaking up scrap metal, without smelting and refining. 

As adopted by TACB 09/18/92 effective 10/23/92