327 IAC 5-1.5-4
327 IAC 5-1.5-4 "Ambient upstream concentration" defined
Cite as Ind. Admin. Code tit. 327, r. 5-1.5-4
Sec. 4. "Ambient upstream concentration" means the concentration of a substance occurring immediately upstream of the point of discharge,
which is present, or likely to be present, in the absence of upstream point source contributions.