Determination of Visible Emission Opacity from Stationary Sources Using Computer-Based Photographic Analysis Systems

(a) Many stationary sources discharge visible emissions into the atmosphere, which are usually in the shape of a plume. The following method describes a technical approach for determining the visible opacity of plume emissions through the use of photographs taken of the regulated source under compliance enforcement conditions. The photographs are processed using computer software that determines visible opacity using information available from the digital or digitized images. The visible opacity determination method includes procedures for the validation of both the computer opacity analysis software system as well as performance specifications for camera hardware.