Special purpose plans can also be prepared to address unique issues in select nonattainment or maintenance areas, such as transport of pollutants across large areas in the case of O $_{3}$, and the formation of regional haze in the case of PM. 

## 2.2.4. General/Transportation Conformity Rules 

The General Conformity Rule of the CAA ensures that actions occurring in EPA -designated NAAQS nonattainment or maintenance areas that receive federal funding, support, approval , or permitting are accounted within, or do not in any way interfere with, the attainment strategy of an EPA-approved SIP(s). 7 

The Transportation Conformity Rule of the CAA governs the federal funding and approval of highway and transit projects occurring in NAAQS nonattainment or maintenance areas such that these activities will not cause new NAAQS violations, exacerbate existing violations, otherwise interfere with an area’s attainment strategy outlined within an EPA-approved SIP(s). 8 

General and Transportation Conformity applicability to airport actions, analysis considerations, coordination points and demonstration options are discussed in Section 8 (Conformity). Areas where General Conformity, Transportation Conformity, and NEPA requirements interface with one another are also highlighted. 

## 2.2.5. Indirect Source Review 

Indirect source review (ISR) requirements are state- specific, and in some states it may be required as part of their SIP when proposed federal actions are located in nonattainment or maintenance areas. Indirect sources may include highways, parking facilities, sports entertainment facilities, and office buildings. Any applicable indirect source requirements should be identified as early as possible during the NEPA scoping process and described in the NEPA documentation. 

The states that require ISR generally establish thresholds for the applicability of ISR . For example, a state may ISR for all projects that increase total airport throughput at an airport by more than 100,000 passengers per year, add 1,000 new parki ng spaces, or increase aircraft operations by 1,000 per year . Projects that exceed the thresholds could be required complete an indirect source analysis and obtain an indirect source permit. 9 

## 2.3. Regulatory Agencies 

There is a wide range of federal, state , and local governmental agencies that are involved in air quality management throughout the U.S. The primary regulatory agencies with jurisdiction in the management of air quality as it pertains to FAA-supported activities are summarized in Table 2­ 2 ( Regulatory Agencies ) along with synopses of their roles and responsibilities. 

