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General Conformity

General Conformity Training Module 2.1: Applicability Process

Words that are shown in bold and italics are defined in the Glossary.

See Figure 3  

2.1.1 Prohibition and geographic areas     

Section 176(c) of the Clean Air Act (CAA) prohibits federal agencies from taking actions in nonattainment and maintenance areas unless the emissions from the actions conform to the State or tribal implementation plan (SIP/TIP) for the area. Based on air quality data and other information, EPA, states and tribes identify specific areas as not meeting a national ambient air quality standard (NAAQS) and EPA designates those areas as nonattainment. In addition to designating areas as nonattainment, EPA, for some pollutants, also classifies areas based on the severity of the pollution problem. EPA publishes the designations and classifications in 40 CFR Part 81. When the air quality in the nonattainment area improves so that the area is meeting the NAAQS, and the state or tribe develops a plan to maintain the air quality, the area can be re-designated as attainment. These areas are known as maintenance areas. The CAA requires federal agencies to demonstrate that the emissions caused by their actions will not interfere with the plans to attain or maintain the NAAQS in both nonattainment and maintenance areas.

The CAA recognizes that ozone and its precursors can be transported over long distances and can impact large regions. To address that concern, the CAA permits the establishment of Ozone Transport Regions and Commissions to coordinate the control of ozone precursors in the region. Of particular concern is the northeast portion of the United States, from Northern Virginia to New England. At present, EPA has not approved any other ozone transport regions. The General Conformity Regulations recognize the potential need to have consistent pollution control requirements throughout the ozone transport region and thus establish more restrictive de minimis emission levels for the lower classification nonattainment and maintenance areas in ozone transport regions.

Section 176(c)(5) of the Clean Air Act limits the application of the conformity regulations to nonattainment and maintenance areas. Therefore, pollutants caused by a federal action and emitted in attainment (not maintenance areas) or undesignated areas are not subject to the requirements of the General Conformity Regulations, even though the emissions may impact a nonattainment or maintenance area.

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2.1.2 De minimis emission levels

In promulgating the General Conformity Regulations, EPA recognized that the many entities of federal government take thousands of actions every day, most of which do not result in significant increases in emissions in nonattainment and maintenance areas. Therefore, EPA promulgated de minimis emissions levels for each of the NAAQS pollutants. If the total direct and indirect emissions from the action are below the de minimis levels, the action is exempt. The de minimis levels are based on an area’s designation and classification and are described in De minimis Table.

If a federal agency determines that its action will result in total direct and indirect emissions in a nonattainment or maintenance area, it must compare the projected emissions to the de minimis levels for that area. The total direct and indirect emissions are the net emission increases in the nonattainment or maintenance area caused by the action. The emissions must be reasonably foreseeable at the time the conformity determination is made. For indirect emissions the federal agency also must be able to practicably control the emissions based upon the agency’s continuing program responsibility.

The emissions from the total action are used to determine if they exceed the de minimis levels. The action cannot be segmented to create several smaller projects with the emissions from each compared to the de minimis levels.

2.1.3 Presumed to conform

In addition to the activities that EPA listed, individual federal agencies are permitted to develop their own list of additional activities that are presumed to conform. The list must meet specific criteria and undergo a public review process. Generally, a federal agency must show that the emissions from that type of action are below the de minimis levels or otherwise will conform with the SIP/TIP. The list can be area specific and does not have to apply to the entire country. An agency taking an action that includes several of these activities is only allowed to claim one activity as a presumed to conform activity. A new provision in the regulations (40 CFR Parts 51 and 93)(27 pp, 287 K, About PDF) allows states to develop a list of activities that are presumed to conform in that state or portion of that state.

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2.1.4 Other exemptions

Since agencies of the federal government make numerous decisions and take numerous actions every day and very few have the potential to cause significant increased emissions in nonattainment or maintenance areas, EPA’s General Conformity Regulations list a number of categories of actions that are presumed to conform, have insignificant emissions, or have emissions that are not reasonably foreseeable (see Table 2 below).

Figure 3. Applicability Analysis
(Click on links to relevant sections)

Figure 3. Applicability AnalysisNAAemergency responsetransportation conformityexempt actionemissions budgetpresumed to conformcalculate emissionsarea classificationdetermine emissionsde minimis levelsspecial provisionsdetermine de minimisdetermine classificationcalculate emissionsdetermine exemptionsend flow chart

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Table 1. De minimis Emission Levels

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Table 2: EPA Exempt Actions

Sub Section of 93.153 Exemption Comment
a. Transportation plans, programs and projects Conformity for these actions are covered under the Transportation Conformity Regulations.
c.1. Total emissions below the de minimis levels

See Table I for the de minimis emission levels

c.2. Actions which would result in no emissions increases in non-attainment or maintenance areas  
c.2.i. Judicial and legislative proceedings  
c.2.ii. Continuing and recurring activities such as permit renewals where activities conducted will be similar in scope and operations to activities currently being conducted Conformity evaluation may be required if the size, scope or frequency of the activity increases.
c.2.iii. Rulemaking and policy development and issuance The process of rulemaking or policy development is exempt however if the resulting rule or policy increases emissions above the de minimis levels in any non-attainment or maintenance area then a conformity determination is required for the rule or policy. See the ruling from the US 9th Circuit Court of Appeals.
c.2.iv. Routine maintenance and repair activities, including repair and maintenance of administrative sites, roads, trails and facilities.  
c.2.v. Civil and criminal enforcement activities, such as investigations, audits, inspections, examinations, prosecutions, and the training of law enforcement personnel Administrative actions  
c.2.vii. The routine, recurring transportation of materials and personnel The quantity and frequency of the activity remains constant.
c.2.viii. Routine movement of mobile assets  
c.2.ix. Maintenance dredging and debris disposal where no new depths are required, applicable permits are secured, and disposal will be at an approved disposal site. Increasing the depth or width of the channel requires an evaluation.
c.2.x. Future activities similar in scope to current activities  
c.2.xi. Granting licenses and leases for activities similar to ongoing activities  
c.2.xii. Planning, studies, and provision of technical assistance This is similar to rulemaking and policy development; planning, studies and provisions are exempt, however, if the following actions by the federal agency may require a conformity determination.
c.2.xiii. Routine operation  
c.2.xiv. Transfers of ownership, interests, and titles in land, facilities, and real and personal properties, regardless of the form or method of the transfer  
c.2.xv. Designation of empowerment zones, enterprise communities, or viticulture areas  
c.2.xvi. Actions by any of the federal banking agencies or the Federal Reserve Banks  
c.2.svii. Actions by the Board of Governors of the Federal Reserve System or any Federal Reserve Bank necessary to effect monetary or exchange rate policy  
c.2.xviii. Actions that implement a foreign affairs function of the United States  
c.2.xix. Actions associated with transfer of land, facilities, title, and real properties through an enforceable contract or lease agreement where the delivery of the deed is required to occur promptly after a specific, reasonable condition is met  
c.2.xx. Transfer of real property, including land, facilities, and related personal property from one federal entity to another  
c.2.xxi. Actions by the Department of the Treasury to effect fiscal policy and to exercise the borrowing authority of the United States  
c.2.xxii. Air traffic above the mixing height for the area The federal agency must use the mixing height specified in the SIP/TIP. If no mixing height is specified, the federal agencies can use the 3,000 feet above ground level as a default mixing height unless the agency demonstrates that a different height is appropriate.
c.3. Actions where the emissions are not reasonably foreseeable  
c.3.i. Initial outer continental shelf lease sales  
c.3.ii. Electric power marketing  
c.4. Actions which implement a decision to conduct or carry out a conforming program  
d.1. NSR or PSD permitted emissions Both major and minor sources are now exempt. A Title V operating permit does not exempt a facility from conformity requirements. However, if the action is covered by the permit, the federal agency may be able to show the emissions are covered in the SIP/FIP in the conformity demonstration.
d.2. Response to emergency events or natural disasters Response to the event or disaster in the first 6 months does not require any conformity evaluation. The exemption can be extended in 6-month increments, provided the federal agency makes a determination that it is impractical to prepare the conformity analyses due to concerns for public health and welfare as well as national security and foreign policy commitment. The exemption cannot be extended beyond 2 years after the event or disaster.
d.3. Research or training that causes no detrimental effects on the environment  
d.4. Action as a result of an environmental regulation  

Emissions resulting from Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) actions; must comply with PSD/NSR program or otherwise be exempt from other environmental regulations under provisions of CERCLA


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