Q82. For a non-Acid Rain combustion turbine rated over 250 mmBtu per hour that only burns diesel oil and pipeline natural gas, is it acceptable to use Tier 2 to calculate CO2 emissions?  Is the use of Tier 2 also allowed if the turbine combusts only one of these fuels?

A82. Yes, to both questions.  Tier 2 may be used in a unit with a maximum rated heat input capacity greater than 250 mmBtu/hr for the combustion of pipeline natural gas and/or distillate fuel oil. (See §98.33(b)(2)(ii) and the definition of “distillate fuel oil” in §98.6.)