Measurements, abbreviations, and acronyms used in this subpart and subparts BBBB through IIII are defined as follows:

Btu—British thermal unit CO2—carbon dioxideH2O—waterHg—mercuryhr—hourkW—kilowatt electrical kWh—kilowatt hour lb—pound mmBtu—million Btu MWe—megawatt electrical MWh—megawatt hour NOX—nitrogen oxides O2—oxygen ppm—parts per million scfh—standard cubic feet per hour SO2—sulfur dioxide yr—year[71 FR 25392, Apr. 28, 2006]