(a) Existing emission sources.

1. (1) No person shall burn in an existing fuel gas combustion device any gas which contains sulfur compounds measured as hydrogen sulfide in excess of 50 grains per 100 standard cubic feet of gas.

2. (2) No person shall cause or allow emissions of any sulfur compound into the outdoor atmosphere from any existing Claus sulfur recovery unit in excess of the amount permitted by table 2, section 212.9(b) of this Title.

   (b) New emission sources and modifications.

3. (1) No person shall burn in a fuel gas combustion device or modification thereof, for which an application for a permit to construct is received by the commissioner pursuant to Part 201 of this Title, subsequent to June 11, 1973, any fuel gas which contains hydrogen sulfide in excess of 10 grains per 100 standard cubic feet of gas.
4. (2) A source owner burning a fuel gas containing sulfur compounds in excess of that allowed in paragraph (1) of this subdivision may elect to treat the resulting gases in a manner which limits the release of sulfur compounds to the outdoor atmosphere if he can show to the satisfaction of the commissioner that this results in the reduction of sulfur compound emissions as effectively as compliance with the requirements of paragraph (1) of this subdivision.

5. (3) No person shall emit any gases into the outdoor atmosphere from any Claus sulfur recovery unit for which an application for a permit to construct is received by the commissioner pursuant to Part 201 of this Title, subsequent to October 4, 1976, containing in excess of:

   1. (i) 0.025 percent by volume of sulfur dioxide at zero percent oxygen on a dry basis if emissions are controlled by an oxidation system or a reduction system followed by an afterburner;
   2. (ii) 0.03 percent by volume of reduced sulfur compounds and 0.001 percent by volume of hydrogen sulfide (calculated as SO₂) at zero percent oxygen on a dry basis if emissions are controlled by a reduction system not followed by an after-burner.