Authority: IC 13-14-8; IC 13-17-3-4; IC 13-17-3-11

Affected: IC 13-17

Sec. 2. A source or sources generating fugitive dust shall be in violation of this rule ( 326 IAC 6-4) if any of the following criteria are violated:

1. (1) A source or combination of sources which cause to exist fugitive dust concentrations greater than sixty-seven percent (67%) in excess of ambient upwind concentrations as determined by the following formula:

   P	=	Percentage increase
   R	=	Number of particles of fugitive dust measured at downward receptor site
   U	=	Number of particles of fugitive dust measured at upwind or background site

2. (2) The fugitive dust is comprised of fifty percent (50%) or more respirable dust, then the percent increase of dust concentration in subdivision (1) of this section shall be modified as follows: P_R = (1.5 ± N) P

   Where	N	=	Fraction of fugitive dust that is respirable dust;
   	PR	=	allowable percentage increase in dust concentration above background; and
   	P	=	no value greater than sixty-seven percent (67%).

3. (3) The ground level ambient air concentrations exceed fifty (50) micrograms per cubic meter above background concentrations for a sixty (60) minute period.
4. (4) If fugitive dust is visible crossing the boundary or property line of a source. This subdivision may be refuted by factual data expressed in subdivisions (1), (2) or (3) of this section.

(Air Pollution Control Division; 326 IAC 6-4-2; filed Mar 10, 1988, 1:20 p.m.: 11 IR 2500; readopted filed Dec 26, 2001, 2:57 p.m.: 25 IR 1605; readopted filed Oct 18, 2024, 2:09 p.m.: 20241113-IR-326230809RFA)