(a) No person who owns an air contamination source used in producing nitric acid or sulfuric acid, for which an application for a permit to construct is submitted after August 16, 1971, may cause or allow to be emitted, to the outdoor atmosphere, smoke or visible emissions, except water, having an average opacity equal to or greater than 10 percent (six minutes).

(b) No person who owns an air contamination source used in producing nitric acid or sulfuric acid, for which an application for a permit to construct was received before August 17, 1971, may cause or allow smoke or visible emissions, except water, having an average opacity equal to or greater than 20 percent (six minutes) to be emitted to the outdoor atmosphere.