A. No person shall allow the emission of any air contaminant for a period or periods aggregating more than three (3) minutes in any one hour which is:
1. Darker in shade than that designated no. 2 (40 percent density) on the Ringelmann chart as published by the United States bureau of mines; or
2. Of such opacity as to obscure an observer's view to the same degree as an emission described in subsection A of this section.
B. Testing shall be done in accordance with the procedures manual for sampling and analysis of air pollutants, published by the state air pollution control commission.
C. The visible emissions regulation applicable to equipment installed after the effective date hereof shall be as above, except that the criteria for determining compliance shall be Ringelmann no. 1 or equivalent opacity.
D. The density or opacity of an air contaminant shall be measured at the point of its emission if observable, and if not shall be measured at an observable point on the plume nearest the point of emission. (Ord. 536, 2-20-1973)