Measurements, abbreviations, and acronyms used in this subpart are defined as follows:

Btu—British thermal unitCO2—carbon dioxideCSAPR—Cross-State Air Pollution RuleH2O—waterhr—hourkWh—kilowatt-hourlb—poundmmBtu—million BtuMWe—megawatt electricalMWh—megawatt-hourNOX—nitrogen oxidesO2—oxygenppm—parts per millionscfh—standard cubic feet per hourSIP—State implementation planSO2—sulfur dioxideTR—Transport Ruleyr—year[76 FR 48379, Aug. 8, 2011, as amended at 81 FR 74605, Oct. 26, 2016]