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

Btu—British thermal unit.CO2—carbon dioxide H2O—water Hg—mercury hr—hour kW—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 dioxideyr—year[71 FR 25381, Apr. 28, 2006]