; or (ii) an emission standard for emissions of sulfur dioxide that meets the requirements of paragraph (2); and (B) may not require that such unit comply with both an emission standard for emissions of hydrogen chloride and an emission standard for emissions of sulfur dioxide. (2) Rules for emission limitations (A) In general The Administrator shall require an operator of a coal refuse electric utility steam generating unit to comply, at the election of the operator, with no more than one of the following emission standards: (i) An emission standard for emissions of hydrogen chloride from such unit that is no more stringent than an emission rate of 0.002 pounds per million British thermal units of heat input. (ii) An emission standard for emissions of hydrogen chloride from such unit that is no more stringent than an emission rate of 0.02 pounds per megawatt-hour. (iii) An emission standard for emissions of sulfur dioxide from such unit that is no more stringent than an emission rate of 0.20 pounds per million British thermal units of heat input. (iv) An emission standard for emissions of sulfur dioxide from such unit that is no more stringent than an emission rate of 1.5 pounds per megawatt-hour. (v) An emission standard for emissions of sulfur dioxide from such unit that is no more stringent than capture and control of 93 percent of sulfur dioxide across the generating unit or group of generating units, as determined by comparing— (I) the expected sulfur dioxide generated from combustion of fuels emissions calculated based upon as-fired fuel samples, to (II) the actual sulfur dioxide emissions as measured by a sulfur dioxide continuous emission monitoring system. (B) Measurement An emission standard described in subparagraph (A) shall be measured as a 30 boiler operating day rolling average per coal refuse electric utility steam generating unit or group of coal refuse electric utility steam generating units located at a single coal refuse-fired facility.