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. 

## • Step 4 : Compare Net Emissions to Appropriate De Minimis Threshold(s) 

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. 

## 8.1.1.5. Facility-Wide Emissions Budgets 

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. 

## 8.1.2. Preparing a General Conformity Determination 

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 in 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, 

