FEATHER RIVER AIR QUALITY MANAGEMENT DISTRICT
RULE 3.0 - VISIBLE EMISSIONS
As provided by Section 41701 of the California Health and Safety Code, a person shall not discharge into the atmosphere from any single source of emissions whatsoever, any air contaminants for a period or periods aggregating more than three minutes in any one hour which is:
a. As dark or darker in shade as that designated as No. 2 on the Ringlemen Chart, as published by the United States Bureau of Mines; or
b. Of such opacity as to obscure an observers view to a degree equal to or greater than does smoke described in Subsection 'a' above.