• Step 4 :  Compare Net Emissions to Appropriate  De Minimis  Threshold(s)  Emissions reduction credits,  including certified Airport Emission Reduction  Credits (AERCs) obtained through airport participation in the FAA Voluntary  Airport Low Emissions (VALE) program 103  can be similarly discounted as design  measures from the net emissions associated with the actio n. If this discounting  produces net emissions that are below  de minimis , the need for a formal General  Conformity Determination is circumvented.  If after completing  Steps 1  through  3  the net emissions associated with an action  exceed an applicable  de minimis  threshold(s), the federal agency must prepare a  formal General Conformity Determination for the action.  Provisions of the General Conformity Rule also allow airports to prepare and submit a “facility- wide emissions budget ” for inclusion in the EPA -approved SIP for a nonattainment maintenance area. The budget is established for a set time period and specifies either annual or  seasonal quantities of emissions that must not be exceeded.  A drawback of the facility-wide emissions budget is the requirement for periodic reporting or  compliance monitoring to ensure that the  “budget” is not exceeded . However, if emissions  associated with an action (i.e., total proposed action emissions) are within an airport’s approved  budget, that action is presumed to conform for the purposes of General Conformity. So, a formal  General Conformity Determination would not need to be prepared even if the action’s increase in emissions exceeds an applicable  de minimis  threshold(s).  In instances where a facility has an approved  budget but a portion of the action’s emissions  exceed the approved budget, the federal agency can use the budget to demonstrate Conformity and only the portion in excess would be subject a General Determination. Also, if an area SIP includes a category for airport related or general construction  emissions, an approved budget could be used to exempt construction emissions from  further  Conformity analysis.  Conducting an applicability analysis outlined in  Section 8.1.1  ( Applicability Analysis ) will  define the need for a General Conformity Determination . If required, a General Conformity  Determination must show that, for each year an action’s emissions exceed applicable  de minimis  thresholds for a pollutant or its precursors ( see  Table 8-1 ,  De minimis Thresholds Nonattainment Areas,  and  Table 8-2 ,  De minimis Thresholds in Maintenance Areas ), the  following apply:  • The total direct and indirect emissions from the action are specifically identified accounted in the appl icable federally-approved SIP. (Portions of an action’s emissions  attributable to motor vehicles, as determined by the local MPO, must also be specifically  identified in a conforming transportation plan); or,  103 FAA,  Voluntary Airport Low Emissions Program (VALE) , http://www.faa.gov/airports/environmental/vale/.  74$_{ }$ 8.1.2.  Preparing a General Conformity Determination  8.1.1.5.  Facility-Wide Emissions Budgets  Aviation Emissions and Air Quality Handbook 