• All direct and indirect emissions (not just the portion exceeding  de minimis  threshold(s)  are fully offset such that there is no  net increase in emissions of the pollutant or precursors; or,  • The action will not cause or contribute to a new NAAQS violation in the area based on  area-wide or local air quality modeling, and it will not increase the frequency or severity  of any existing violation; or  • State/local air quality governance agrees to revise the SIP to accommodate the action’s  emissions.  These four demonstration points are further explained as follows.  Through consultation, the federal agency must identify the approved SIP and isolate the action's  emissions within the approved SIP budget for years that the direct and indirect emissions of the  action are subject to a General Conformity Determination. It is preferable that this comparison be  done at the facility level (i.e., the SIP budget should specifically identify an airport and sources for a given year). However, this approach is not always  possible and often it is the case  that only a category -specific comparison can be made (i.e., Airport ’s aircraft emissions are  compared to the SIP aircraft budget for the entire nonattainment area). For each year requiring  a  Conformity Determination, it must be de monstrated that the action’s emissions are within the  applicable SIP budget line or category.  In the case of motor vehicles, a motor vehicle emissions budget in the approved SIP can only be  used for comparison purposes if the action is specifica lly identif ied in a conforming  Transportation Plan as determined by the local MPO. If the action is not specifically included in  this fashion, the motor vehicle emissions predicted from the action must be shown to conform in  a manner that does not utilize the SIP motor vehicle emissions budget. These instances require  close coordination with the MPO to ensure the action’s emissions could then be accommodated.  If identifying an action’s emissions in the SIP is the selected General Conformity strategy,  Conformity would be demonstrated by securing statements of concurrence from the state/local  air agency, the MPO, and in some cases the EPA regional authority, that the action’ s emissions  are contained within the SIP and that the action conforms per the General Conformity Rule.  As mentioned, an action’s direct and indirect emissions must be fully offset to zero if emissions  mitigation and offsetting are used as a General Conformity strategy. In the case of O$_{3 }$and PM, a  state agency can approve offsets or mitigation measures of different precursors of the pollutant only if such trades are allowed by local regulation, are technically justified, and have a  demonstrated environmental benefit. For instance, if an action causes a reduction in emissions of  the O 3  precursor VOC, these reductions could be used,  with approval, to offset an action’s  increase in NO$_{x }$emissions (also an O$_{3 }$precursor).  In terms of timing,  the General Conformity Rule  generally requires that emissions reductions  from an offset or mitigation measures used to demonstrate conformity must occur during the  same calendar year as the emissions subject to Conformity. However, exceptions to this rule are  8.1.2.2.  Emissions Mitigation and Offsetting  8.1.2.1.  Identifying Emissions in the SIP  Aviation Emissions and Air Quality Handbook  75$_{ }$