Aviation Emissions and Air Quality Handbook  73$_{ }$ 102 Reasonably foreseeable emissions include all quantifiable emissions from an action that are known at  the time of the General Conformity evaluation. Direct emissions from an action are those that caused  by the action and occur in the same time and place. Indirect emissions represent emissions caused by  the action that occur in a different time and place but are under the practical control of the agency.  − The attainment year specified in the approved SIP, or the latest attainment  year possible under the CAA;  − The last year for which emissions are projected in a maintenance plan;  − The year during which the total direct and indirect  emissions from the  action is expected to be greatest on an annual basis; and  − Any year for which the approved SIP contains an emissions budget.  • Step 1 :  Select Appropriate Comparison Year(s)  • Step 3 :  Identify Emissions Reductions Measures  • Step 2 :  Prepare Emissions Inventories  Compute an inventory of all  “reasonably foreseeable direct and indirect  emissions” associated with the action once implemented (i.e., the proposed action  emissions). 102  Also inventory emissions that would occur irrespective of the action  (i.e., the no action emissions). Subtract the no action emissions from the proposed  action emissions to determine the net increase associated with the action’s  operation.  For actions involving construction activities, prepare an emissions inventory for  each year of planned construction, including all reasonably foreseeable direct and  indirect emissions (e.g., on-site equipment and off-site haul trucks).  Features of an action that by design have an emissions reducing effect are called  “design measures” and are typically accounted for in the emissions inventories of  the action prepared in  Step 2 . For instance, if an action includes installing  additional terminal gates, and these gates are equipped with gate electrification  infrastructure, the resulting emissions benefit of defrayed APU usage would then  by virtue be included in the emissions inventory.  Of note, the comparison years required for General Conformity may or may not  be aligned with  timeframes utilized in the NEPA document  for an air quality  impact assessment. As such, it is advantageous for both  the NEPA and General  Conformity processes to be considered during project scoping and planning  such  that all requirements can be satisfied as needed.  The selection of years for which a  de minimis  comparison should be conducted  must be selected with discretion to ensure that General Conformity requirements  are fully addressed. These years include the following: 