TITLE 35: ENVIRONMENTAL PROTECTION
SUBTITLE B: AIR POLLUTION
CHAPTER I: POLLUTION CONTROL BOARD
SUBCHAPTER c: EMISSION STANDARDS AND LIMITATIONS FOR STATIONARY SOURCES
PART 211 DEFINITIONS AND GENERAL PROVISIONS
SECTION 211.4130 OPACITY
SUBTITLE B: AIR POLLUTION
CHAPTER I: POLLUTION CONTROL BOARD
SUBCHAPTER c: EMISSION STANDARDS AND LIMITATIONS FOR STATIONARY SOURCES
PART 211 DEFINITIONS AND GENERAL PROVISIONS
SECTION 211.4130 OPACITY
Section 211.4130 Opacity
"Opacity" means that fraction of light, expressed in percent, which when transmitted from a source through a smoke-obscured path, is prevented from reaching the observer or instrument receiver.
(Source: Amended at 20 Ill. Reg. 7590, effective May 22, 1996)