WAC 173-460-020   Definitions.  The definitions of terms contained in chapter 173-400 WAC are incorporated into this chapter by reference. Terms specific to this chapter are defined as follows:

     (1) "Acceptable source impact analysis" means a procedure for demonstrating compliance with WAC 173-460-070, that compares maximum incremental ambient air impacts with applicable acceptable source impact levels (ASIL).

     (2) "Acceptable source impact level (ASIL)" means a screening concentration of a toxic air pollutant in the ambient air. The ASIL for each toxic air pollutant is listed in WAC 173-460-150.

     (3) "Best available control technology for toxics (tBACT)" means best available control technology, as that term is defined in WAC 173-400-030, as applied to toxic air pollutants.

     (4) "De minimis emissions" means trivial levels of emissions that do not pose a threat to human health or the environment. The de minimis emission threshold values are listed in WAC 173-460-150.

     (5) "Increased cancer risk of one in one hundred thousand" means the 95th percent upper bound on the estimated risk of one additional cancer above the background cancer rate per one hundred thousand individuals continuously exposed to a carcinogenic toxic air pollutant at a given average dose for a specified time.

     (6) "New or modified toxic air pollutant source" means the construction or modification of a stationary source that increases the amount of any toxic air pollutant emitted by such source or that results in the emission of any toxic air pollutant not previously emitted.

     (7) "Small quantity emission rate (SQER)" means a level of emissions below which dispersion modeling is not required to demonstrate compliance with acceptable source impact levels. SQERs are listed in WAC 173-460-150.

     (8) "Toxic air pollutant (TAP)" means any toxic air pollutant listed in WAC 173-460-150.



[Statutory Authority: Washington Clean Air Act, RCW 70.94.152. 09-11-131 (Order 05-19), § 173-460-020, filed 5/20/09, effective 6/20/09. Statutory Authority: Chapter 70.94 RCW. 94-03-072 (Order 93-19), § 173-460-020, filed 1/14/94, effective 2/14/94. Statutory Authority: RCW 70.94.331. 91-13-079 (Order 90-62), § 173-460-020, filed 6/18/91, effective 9/18/91.]