Section 204.620  Replacement Unit

"Replacement unit" means an emissions unit for which all the criteria listed in this Section are met.  No creditable emission reductions shall be generated from shutting down the existing emissions unit that is replaced.

a)         The emissions unit is a reconstructed unit, within the meaning of 40 CFR 60.15(b)(1), or completely takes the place of an existing emissions unit.

b)         The emissions unit is identical to or functionally equivalent to the replaced emissions unit.

c)         The replacement does not alter the basic design parameter or parameters of the process unit.  Basic design parameters of a process unit shall be determined as follows:

1)         Except as provided in subsection (c)(3), for a process unit at a steam electric generating facility, the owner or operator may select as its basic design parameters either maximum hourly heat input and maximum hourly fuel consumption rate or maximum hourly electric output rate and maximum steam flow rate.  When establishing fuel consumption specifications in terms of weight or volume, the minimum fuel quality based on Btu content shall be used for determining the basic design parameter or parameters for a coal-fired electric utility steam generating unit.

2)         Except as provided in subsection (c)(3), the basic design parameter or parameters for any process unit that is not at a steam electric generating facility are maximum rate of fuel or heat input, maximum rate of material input, or maximum rate of product output.  Combustion process units will typically use maximum rate of fuel input.  For sources having multiple end products and raw materials, the owner or operator should consider the primary product or primary raw material when selecting a basic design parameter.

3)         If the owner or operator believes the basic design parameter or parameters in subsections (c)(1) and (c)(2) are not appropriate for a specific industry or type of process unit, the owner or operator may propose to the Agency an alternative basic design parameter or parameters for the source's process unit or units.  If the Agency approves of the use of an alternative basic design parameter or parameters, the Agency shall issue a permit that is legally enforceable, records such basic design parameter or parameters and requires the owner or operator to comply with such parameter or parameters.

4)         The owner or operator shall use credible information, such as results of historic maximum capability tests, design information from the manufacturer, or engineering calculations, in establishing the magnitude of the basic design parameter or parameters specified in subsections (c)(2) and (c)(3).

5)         If design information is not available for a process unit, the owner or operator shall determine the process unit's basic design parameter or parameters using the maximum value achieved by the process unit in the five-year period immediately preceding the planned activity.

6)         Efficiency of a process unit is not a basic design parameter.

d)         The replaced emissions unit is permanently removed from the major stationary source, otherwise permanently disabled, or permanently barred from operation by a permit that is enforceable as a practical matter.  If the replaced emissions unit is brought back into operation, it shall constitute a new emissions unit.