Measurements, abbreviations, and acronyms used in this subpart and subparts BBB through III 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.