Measurements, abbreviations, and acronyms used in this subpart and subparts BBBB through IIII 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 dioxide. yr—year.