DETERMINING APPLICABLE STANDARDS OF PERFORMANCE

Subpart 1. Scope. Parts 7011.0500 to 7011.0550 shall apply to indirect heating equipment for which a standard of performance has not been promulgated in a specific rule. Subp. 2. Rated heat input. The applicable standards of performance in part 7011.0545 or 7011.0550 shall be determined by using the rated heat input of the specific indirect heating equipment and the total rated heat inputs of all indirect heating equipment and all direct heating equipment of one owner or operator at that particular location. Subp. 3. Simultaneous burning of different fuels. Simultaneous burning of different fuels: A. When different fossil fuels are burned simultaneously in any combination, the applicable sulfur dioxide standard shall be determined by proration using the following formula: y(a) + z(b) w = _ x + y + z where: w is the maximum allowable emissions of sulfur dioxide gases in lbs per million Btu (nanograms/joule); x is the percentage of total heat input derived from gaseous fossil fuel; y is the percentage of total heat input derived from liquid fossil fuel; z is the percentage of total heat input derived from solid fossil fuel; a is the allowable SO 2 standard for liquid fossil fuels expressed in lbs per million Btu (nanograms/joule); and b is the allowable SO 2 standard for solid fossil fuels expressed in lbs per million Btu (nanograms/joule). B. When different fossil fuels are burned simultaneously in any combination, the applicable nitrogen oxides standard shall be determined by proration using the following formula: x(c) + y(a) + z(b) w = _ x + y + z where: w, x, y, and z mean the same as in the formula in item A, for determining the applicable sulfur dioxide standard; a is the allowable NO x standard for liquid fossil fuels expressed in lbs per million Btu (nanograms/joule); b is the allowable NO x standard for solid fossil fuels expressed in lbs per million Btu (nanograms/joule); and c is the allowable NO x standard for gaseous fossil fuels expressed in lbs per million Btu (nanograms/joule). Subp. 4. Exception. When lignite or a solid fossil fuel containing 25 percent by weight, or more, of coal refuse is burned in combination with gaseous, liquid, or other solid fossil fuel, the standard of performance for nitrogen oxides shall not apply.