SAN DIEGO COUNTY AIR POLLUTION CONTROL DISTRICT

RULE 260.43a - STANDARD FOR SULFUR DIOXIDE

(a) On and after the date on which the initial performance test required to be conducted under Rule 260.8 is completed, no owner or operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere from any affected facility which combusts solid fuel or solid-derived fuel, except as provided under sections (c), (d), (f) or (h) of this rule, any gases which contain sulfur dioxide in excess of:

1. 520 ng/J (1.20 lb/million Btu) heat input and 10 percent of the potential combustion concentration (90 percent reduction), or
2. 30 percent of the potential combustion concentration (70 percent reduction), when emissions are less than 260 ng/J (0.60 lb/million Btu) heat input.

(b) On and after the date on which the initial performance test required to be conducted under Rule 260.8 is completed, no owner or operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere from any affected facility which combusts liquid or gaseous fuels (except for liquid or gaseous fuels derived from solid fuels and as provided under sections (e) or (h) of this rule), any gases which contain sulfur dioxide in excess of:

1. 340 ng/J (0.80 lb/million Btu) heat input and 10 percent of the potential combustion concentration (90 percent reduction), or
2. 100 percent of the potential combustion concentration (zero percent reduction) when emissions are less than 86 ng/J (0.20 lb/million Btu) heat input.

(c) On and after the date on which the initial performance test required to be conducted under Rule 260.8 is complete, no owner or operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere from any affected facility which combusts solid solvent refined coal (SRC-I) any gases which contain sulfur dioxide in excess of 520 ng/J (1.20 lb/million Btu) heat input and 15 percent of the potential combustion concentration (85 percent reduction) except as provided under Section (f) of this rule; compliance with the emissions limitation is determined on a 30-day rolling average basis and compliance with the percent reduction requirement is determined on a 24-hour basis.

(d) Sulfur dioxide emissions are limited to 520 ng/J (1.20 lb/million Btu) heat input from any affected facility which:

1. Combusts 100 percent anthracite,
2. Is classified as a resource recovery facility, or
3. Is located in a noncontinental area and combusts solid fuel or solid-derived fuel.

(e) Sulfur dioxide emissions are limited to 340 ng/J (0.80 lb/million Btu) heat input from any affected facility which is located in a noncontinental area and combusts liquid or gaseous fuels (excluding solid-derived fuels).

(f) The emission reduction requirements under this rule do not apply to any affected facility that is operated under an SO₂ commercial demonstration permit issued by the Administrator in accordance with the provisions of Rule 260.45a.

(g) Compliance with the emission limitation and percent reduction requirements under this rule are both determined on a 30-day rolling average basis except as provided under Section (c) of this rule.

(h) When different fuels are combusted simultaneously, the applicable standard is determined by proration using the following formula:

1. If emissions of sulfur dioxide to the atmosphere are greater than 260 ng/J (0.60 lb/million Btu) heat input
   E_SO2 = [340x + 520y]/100 and

   P_SO2 = 10 percent

2. If emissions of sulfur dioxide to the atmosphere are equal to or less than 260 ng/J (0.60 lb/million Btu) heat input:
   E_SO2 = [340x + 520y]/100 and

   P_SO2 = [90x + 70y]/100

   where,

   E_SO2 is the prorated sulfur dioxide emission limit (ng/J heat input),

   P_SO2 is the percentage of potential sulfur dioxide emission allowed (percent reduction required = 100 - P_SO2),

   x is the percentage of total heat input derived from the combustion of liquid or gaseous fuels (excluding solid-derived fuels),

   y is the percentage of total heat input derived f rom the combustion of solid fuel (including solid-derived fuels).