Section 326IAC6-4-2. Emission limitations

   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) 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) 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) The ground level ambient air concentrations exceed fifty (50) micrograms per cubic meter above background concentrations for a sixty (60) minute period.

(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)