NORTHERN SIERRA AIR QUALITY MANAGEMENT DISTRICT

RULE 202 - VISIBLE EMISSIONS
(Adopted: September 11, 1991)

A person shall not discharge into the atmosphere from any single source of emission whatsoever any air contaminant for a period or periods aggregating more than three (3) minutes in any one (1) hour which is:

1. As dark or darker in shade as that designated as No. 1 on the Ringlemann Chart, as published by the United States Bureau of Mines, or
2. Of such opacity as to obscure an observer's view to a degree equal to or greater than does smoke described in subsection (A) of this section.