(a) No department, agency or instrumentality of the Federal Government shall engage in, support in any way or provide financial assistance for, license or permit, or approve any activity which does not conform to an applicable implementation plan.

(b) A Federal agency must make a determination that a Federal action conforms to the applicable implementation plan in accordance with the requirements of this subpart before the action is taken.

(c) [Reserved]

(d) Notwithstanding any provision of this subpart, a determination that an action is in conformance with the applicable implementation plan does not exempt the action from any other requirements of the applicable implementation plan, the National Environmental Policy Act (NEPA), or the Clean Air Act (Act).

(e) If an action would result in emissions originating in more than one nonattainment or maintenance area, the conformity must be evaluated for each area separately.

The provisions and requirements of this subpart to demonstrate conformity required under section 176(c) of the Clean Air Act (CAA) apply to all Federal actions in designated nonattainment and maintenance areas where EPA has not approved the General Conformity SIP revision allowed under 40 CFR 51.851. When EPA approves a State's or Tribe's conformity provisions (or a portion thereof) in a revision to an applicable implementation plan, a conformity evaluation is governed by the approved (or approved portion of the) State or Tribe's criteria and procedures. The Federal conformity regulations contained in this subpart apply only for the portions, if any, of the part 93 requirements not contained in the State or Tribe conformity provisions approved by EPA. In addition, any previously applicable implementation plan conformity requirements remain enforceable until the EPA approves the revision to the applicable SIP to specifically include the revised requirements or remove requirements.

Terms used but not defined in this part shall have the meaning given them by the Act and EPA's regulations (40 CFR chapter I), in that order of priority.

Affected Federal land manager means the Federal agency or the Federal official charged with direct responsibility for management of an area designated as Class I under the Act (42 U.S.C. 7472) that is located within 100 km of the proposed Federal action.

Applicability analysis is the process of determining if your Federal action must be supported by a conformity determination.

Applicable implementation plan or applicable SIP means the portion (or portions) of the SIP or most recent revision thereof, which has been approved under section 110(k) of the Act, a Federal implementation plan promulgated under section 110(c) of the Act, or a plan promulgated or approved pursuant to section 301 (d) of the Act (Tribal implementation plan or TIP) and which implements the relevant requirements of the Act.

Areawide air quality modeling analysis means an assessment on a scale that includes the entire nonattainment or maintenance area using an air quality dispersion model or photochemical grid model to determine the effects of emissions on air quality, for example, an assessment using EPA's community multi-scale air quality (CMAQ) modeling system.

Cause or contribute to a new violation means a Federal action that:

(1) Causes a new violation of a national ambient air quality standard (NAAQS) at a location in a nonattainment or maintenance area which would otherwise not be in violation of the standard during the future period in question if the Federal action were not taken; or

(2) Contributes, in conjunction with other reasonably foreseeable actions, to a new violation of a NAAQS at a location in a nonattainment or maintenance area in a manner that would increase the frequency or severity of the new violation.

Caused by, as used in the terms “direct emissions” and “indirect emissions,” means emissions that would not otherwise occur in the absence of the Federal action.

Confidential business information (CBI) means information that has been determined by a Federal agency, in accordance with its applicable regulations, to be a trade secret, or commercial or financial information obtained from a person and privileged or confidential and is exempt from required disclosure under the Freedom of Information Act (5 U.S.C. 552(b)(4)).

Conformity determination is the evaluation (made after an applicability analysis is completed) that a Federal action conforms to the applicable implementation plan and meets the requirements of this subpart.

Conformity evaluation is the entire process from the applicability analysis through the conformity determination that is used to demonstrate that the Federal action conforms to the requirements of this subpart.

Continuing program responsibility means a Federal agency has responsibility for emissions caused by:

(1) Actions it takes itself; or

(2) Actions of non-Federal entities that the Federal agency, in exercising its normal programs and authorities, approves, funds, licenses or permits, provided the agency can impose conditions on any portion of the action that could affect the emissions.

Continuous program to implement means that the Federal agency has started the action identified in the plan and does not stop the actions for more than an 18-month period, unless it can demonstrate that such a stoppage was included in the original plan.

Criteria pollutant or standard means any pollutant for which there is established a NAAQS at 40 CFR part 50.

Direct emissions means those emissions of a criteria pollutant or its precursors that are caused or initiated by the Federal action and originate in a nonattainment or maintenance area and occur at the same time and place as the action and are reasonably foreseeable.

Emergency means a situation where extremely quick action on the part of the Federal agencies involved is needed and where the timing of such Federal activities makes it impractical to meet the requirements of this subpart, such as natural disasters like hurricanes or earthquakes, civil disturbances such as terrorist acts and military mobilizations.

Emission inventory means a listing of information on the location, type of source, type and quantity of pollutant emitted as well as other parameters of the emissions.

Emissions budgets are those portions of the applicable SIP's projected emission inventories that describe the levels of emissions (mobile, stationary, area, etc.) that provide for meeting reasonable further progress milestones, attainment, and/or maintenance for any criteria pollutant or its precursors.

Emissions offsets, for purposes of § 93.158, are emissions reductions which are quantifiable, consistent with the applicable SIP attainment and reasonable further progress demonstrations, surplus to reductions required by, and credited to, other applicable SIP provisions, enforceable at both the State and Federal levels, and permanent within the timeframe specified by the program.

EPA means the U.S. Environmental Protection Agency.

Federal action means any activity engaged in by a department, agency, or instrumentality of the Federal government, or any activity that a department, agency or instrumentality of the Federal government supports in any way, provides financial assistance for, licenses, permits, or approves, other than activities related to transportation plans, programs, and projects developed, funded, or approved under title 23 U.S.C. or the Federal Transit Act (49 U.S.C. 1601 et seq.). Where the Federal action is a permit, license, or other approval for some aspect of a non-Federal undertaking, the relevant activity is the part, portion, or phase of the non-Federal undertaking that requires the Federal permit, license, or approval.

Federal agency means, for purposes of this subpart, a Federal department, agency, or instrumentality of the Federal government.

Increase the frequency or severity of any existing violation of any standard in any area means to cause a nonattainment area to exceed a standard more often or to cause a violation at a greater concentration than previously existed and/or would otherwise exist during the future period in question, if the project were not implemented.

Indirect emissions means those emissions of a criteria pollutant or its precursors:

(1) That are caused or initiated by the Federal action and originate in the same nonattainment or maintenance area but occur at a different time or place as the action;

(2) That are reasonably foreseeable;

(3) That the agency can practically control; and

(4) For which the agency has continuing program responsibility.

For the purposes of this definition, even if a Federal licensing, rulemaking or other approving action is a required initial step for a subsequent activity that causes emissions, such initial steps do not mean that a Federal agency can practically control any resulting emissions.

Local air quality modeling analysis means an assessment of localized impacts on a scale smaller than the entire nonattainment or maintenance area, including, for example, congested roadways on a Federal facility, which uses an air quality dispersion model (e.g., Industrial Source Complex Model or Emission and Dispersion Model System) to determine the effects of emissions on air quality.

Maintenance area means an area that was designated as nonattainment and has been re-designated in 40 CFR part 81 to attainment, meeting the provisions of section 107(d)(3)(E) of the Act and has a maintenance plan approved under section 175A of the Act.

Maintenance plan means a revision to the applicable SIP, meeting the requirements of section 175A of the Act.

Metropolitan Planning Organization (MPO) means the policy board of an organization created as a result of the designation process in 23 U.S.C. 134(d).

Milestone has the meaning given in sections 182(g)(1) and 189(c)(1) of the Act.

Mitigation measure means any method of reducing emissions of the pollutant or its precursor taken at the location of the Federal action and used to reduce the impact of the emissions of that pollutant caused by the action.

National ambient air quality standards (NAAQS) are those standards established pursuant to section 109 of the Act and include standards for carbon monoxide (CO2), lead (Pb), nitrogen dioxide (NO2), ozone, particulate matter (PM-10 and PM2.5), and sulfur dioxide (SO2).

Nonattainment area means an area designated as nonattainment under section 107 of the Act and described in 40 CFR part 81.

Precursors of a criteria pollutant are:

(1) For ozone, nitrogen oxides (NOx), unless an area is exempted from NOx requirements under section 182(f) of the Act, and volatile organic compounds (VOC).

(2) For PM-10, those pollutants described in the PM-10 nonattainment area applicable SIP as significant contributors to the PM-10 levels.

(3) For PM2.5:

(i) Sulfur dioxide (SO2) in all PM2.5 nonattainment and maintenance areas,

(ii) Nitrogen oxides in all PM2.5 nonattainment and maintenance areas unless both the State and EPA determine that it is not a significant precursor, and

(iii) Volatile organic compounds (VOC) and ammonia (NH3) only in PM2.5 nonattainment or maintenance areas where either the State or EPA determines that they are significant precursors.

Reasonably foreseeable emissions are projected future direct and indirect emissions that are identified at the time the conformity determination is made; the location of such emissions is known and the emissions are quantifiable as described and documented by the Federal agency based on its own information and after reviewing any information presented to the Federal agency.

Regional water and/or wastewater projects include construction, operation, and maintenance of water or wastewater conveyances, water or wastewater treatment facilities, and water storage reservoirs which affect a large portion of a nonattainment or maintenance area.

Restricted information is information that is privileged or that is otherwise protected from disclosure pursuant to applicable statutes, Executive Orders, or regulations. Such information includes, but is not limited to: Classified national security information, protected critical infrastructure information, sensitive security information, and proprietary business information.

Take or start the Federal action means the date that the Federal agency signs or approves the permit, license, grant or contract or otherwise physically begins the Federal action that requires a conformity evaluation under this subpart.

Total of direct and indirect emissions means the sum of direct and indirect emissions increases and decreases caused by the Federal action; i.e., the “net” emissions considering all direct and indirect emissions. The portion of emissions which are exempt or presumed to conform under § 93.153 (c), (d), (e), or (f) are not included in the “total of direct and indirect emissions.” The “total of direct and indirect emissions” includes emissions of criteria pollutants and emissions of precursors of criteria pollutants.

Tribal implementation plan (TIP) means a plan to implement the national ambient air quality standards adopted and submitted by a federally recognized Indian tribal government determined to be eligible under 40 CFR 49.9 and the plan has been approved by EPA.

(a) Conformity determinations for Federal actions related to transportation plans, programs, and projects developed, funded, or approved under title 23 U.S.C. or the Federal Transit Act (49 U.S.C. 1601 et seq.) must meet the procedures and criteria of 40 CFR part 51, subpart T, in lieu of the procedures set forth in this subpart.

(b) For Federal actions not covered by paragraph (a) of this section, a conformity determination is required for each criteria pollutant or precursor where the total of direct and indirect emissions of the criteria pollutant or precursor in a nonattainment or maintenance area caused by a Federal action would equal or exceed any of the rates in paragraphs (b)(1) or (2) of this section.

(1) For purposes of paragraph (b) of this section the following rates apply in nonattainment areas (NAA's):

(2) For purposes of paragraph (b) of this section the following rates apply in maintenance areas:

(c) The requirements of this subpart shall not apply to the following Federal actions:

(1) Actions where the total of direct and indirect emissions are below the emissions levels specified in paragraph (b) of this section.

(2) Actions which would result in no emissions increase or an increase in emissions that is clearly de minimis:

(i) Judicial and legislative proceedings.

(ii) Continuing and recurring activities such as permit renewals where activities conducted will be similar in scope and operation to activities currently being conducted.

(iii) Rulemaking and policy development and issuance.

(iv) Routine maintenance and repair activities, including repair and maintenance of administrative sites, roads, trails, and facilities.

(v) Civil and criminal enforcement activities, such as investigations, audits, inspections, examinations, prosecutions, and the training of law enforcement personnel.

(vi) Administrative actions such as personnel actions, organizational changes, debt management or collection, cash management, internal agency audits, program budget proposals, and matters relating to the administration and collection of taxes, duties and fees.

(vii) The routine, recurring transportation of materiel and personnel.

(viii) Routine movement of mobile assets, such as ships and aircraft, in home port reassignments and stations (when no new support facilities or personnel are required) to perform as operational groups and/or for repair or overhaul.

(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.

(x) Actions, such as the following, with respect to existing structures, properties, facilities and lands where future activities conducted will be similar in scope and operation to activities currently being conducted at the existing structures, properties, facilities, and lands; for example, relocation of personnel, disposition of federally-owned existing structures, properties, facilities, and lands, rent subsidies, operation and maintenance cost subsidies, the exercise of receivership or conservatorship authority, assistance in purchasing structures, and the production of coins and currency.

(xi) The granting of leases, licenses such as for exports and trade, permits, and easements where activities conducted will be similar in scope and operation to activities currently being conducted.

(xii) Planning, studies, and provision of technical assistance.

(xiii) Routine operation of facilities, mobile assets and equipment.

(xiv) Transfers of ownership, interests, and titles in land, facilities, and real and personal properties, regardless of the form or method of the transfer.

(xv) The designation of empowerment zones, enterprise communities, or viticultural areas.

(xvi) Actions by any of the Federal banking agencies or the Federal Reserve Banks, including actions regarding charters, applications, notices, licenses, the supervision or examination of depository institutions or depository institution holding companies, access to the discount window, or the provision of financial services to banking organizations or to any department, agency or instrumentality of the United States.

(xvii) Actions by the Board of Governors of the Federal Reserve System or any Federal Reserve Bank necessary to effect monetary or exchange rate policy.

(xviii) Actions that implement a foreign affairs function of the United States.

(xix) Actions (or portions thereof) associated with transfers 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, such as promptly after the land is certified as meeting the requirements of CERCLA, and where the Federal agency does not retain continuing authority to control emissions associated with the lands, facilities, title, or real properties.

(xx) Transfers of real property, including land, facilities, and related personal property from a Federal entity to another Federal entity and assignments of real property, including land, facilities, and related personal property from a Federal entity to another Federal entity for subsequent deeding to eligible applicants.

(xxi) Actions by the Department of the Treasury to effect fiscal policy and to exercise the borrowing authority of the United States.

(xxii) Air traffic control activities and adopting approach, departure, and enroute procedures for aircraft operations above the mixing height specified in the applicable SIP or TIP. Where the applicable SIP or TIP does not specify a mixing height, the Federal agency can use the 3,000 feet above ground level as a default mixing height, unless the agency demonstrates that use of a different mixing height is appropriate because the change in emissions at and above that height caused by the Federal action is de minimis.

(3) Actions where the emissions are not reasonably foreseeable, such as the following:

(i) Initial Outer Continental Shelf lease sales which are made on a broad scale and are followed by exploration and development plans on a project level.

(ii) Electric power marketing activities that involve the acquisition, sale and transmission of electric energy.

(4) Actions which implement a decision to conduct or carry out a conforming program such as prescribed burning actions which are consistent with a conforming land management plan.

(d) Notwithstanding the other requirements of this subpart, a conformity determination is not required for the following Federal actions (or portion thereof):

(1) The portion of an action that includes major or minor new or modified stationary sources that require a permit under the new source review (NSR) program (Section 110(a)(2)(c) and Section 173 of the Act) or the prevention of significant deterioration program (title I, part C of the Act).

(2) Actions in response to emergencies which are typically commenced on the order of hours or days after the emergency and, if applicable, which meet the requirements of paragraph (e) of this section.

(3) Research, investigations, studies, demonstrations, or training (other than those exempted under paragraph (c)(2) of this section), where no environmental detriment is incurred and/or, the particular action furthers air quality research, as determined by the State agency primarily responsible for the applicable SIP;

(4) Alteration and additions of existing structures as specifically required by new or existing applicable environmental legislation or environmental regulations (e.g., hush houses for aircraft engines and scrubbers for air emissions).

(5) Direct emissions from remedial and removal actions carried out under the Comprehensive Environmental Response, Compensation and Liability Act and associated regulations to the extent such emissions either comply with the substantive requirements of the PSD/NSR permitting program or are exempted from other environmental regulation under the provisions of CERCLA and applicable regulations issued under CERCLA.

(e) Federal actions which are part of a continuing response to an emergency or disaster under paragraph (d)(2) of this section and which are to be taken more than 6 months after the commencement of the response to the emergency or disaster under paragraph (d)(2) of this section are exempt from the requirements of this subpart only if:

(1) The Federal agency taking the actions makes a written determination that, for a specified period not to exceed an additional 6 months, it is impractical to prepare the conformity analyses which would otherwise be required and the actions cannot be delayed due to overriding concerns for public health and welfare, national security interests and foreign policy commitments; or

(2) For actions which are to be taken after those actions covered by paragraph (e)(1) of this section, the Federal agency makes a new determination as provided in paragraph (e)(1) of this section and:

(i) Provides a draft copy of the written determinations required to affected EPA Regional office(s), the affected State(s) and/or air pollution control agencies, and any Federal recognized Indian tribal government in the nonattainment or maintenance area. Those organizations must be allowed 15 days from the beginning of the extension period to comment on the draft determination; and

(ii) Within 30 days after making the determination, publish a notice of the determination by placing a prominent advertisement in a daily newspaper of general circulation in the area affected by the action.

(3) If additional actions are necessary in response to an emergency or disaster under paragraph (d)(2) of this section beyond the specified time period in paragraph (e)(2) of this section, a Federal agency can make a new written determination as described in (e)(2) of this section for as many 6-month periods as needed, but in no case shall this exemption extend beyond three 6-month periods except where an agency:

(i) Provides information to EPA and the State or Tribe stating that the conditions that gave rise to the emergency exemption continue to exist and how such conditions effectively prevent the agency from conducting a conformity evaluation.

(ii) [Reserved]

(f) Notwithstanding other requirements of this subpart, actions specified by individual Federal agencies that have met the criteria set forth in either paragraphs (g)(1), (g)(2), or (g)(3) of this section and the procedures set forth in paragraph (h) of this section are “presumed to conform,” except as provided in paragraph (j) of this section. Actions specified by individual Federal agencies as “presumed to conform” may not be used in combination with one another when the total direct and indirect emissions from the combination of actions would equal or exceed any of the rates specified in paragraphs (b)(1) or (2) of this section.

(g) The Federal agency must meet the criteria for establishing activities that are “presumed to conform” by fulfilling the requirements set forth in either paragraphs (g)(1), (g)(2), or (g)(3) of this section:

(1) The Federal agency must clearly demonstrate using methods consistent with this subpart that the total of direct and indirect emissions from the type of activities which would be presumed to conform would not:

(i) Cause or contribute to any new violation of any standard in any area;

(ii) Interfere with provisions in the applicable SIP for maintenance of any standard;

(iii) Increase the frequency or severity of any existing violation of any standard in any area; or

(iv) Delay timely attainment of any standard or any required interim emission reductions or other milestones in any area including, where applicable, emission levels specified in the applicable SIP for purposes of:

(A) A demonstration of reasonable further progress;

(B) A demonstration of attainment; or

(C) A maintenance plan; or

(2) The Federal agency must provide documentation that the total of direct and indirect emissions from such future actions would be below the emission rates for a conformity determination that are established in paragraph (b) of this section, based, for example, on similar actions taken over recent years.

(3) The Federal agency must clearly demonstrate that the emissions from the type or category of actions and the amount of emissions from the action are included in the applicable SIP and the State, local, or tribal air quality agencies responsible for the SIP(s) or TIP(s) provide written concurrence that the emissions from the actions along with all other expected emissions in the area will not exceed the emission budget in the SIP.

(h) In addition to meeting the criteria for establishing exemptions set forth in paragraphs (g)(1), (g)(2), or (g)(3) of this section, the following procedures must also be complied with to presume that activities will conform:

(1) The Federal agency must identify through publication in the Federal Register its list of proposed activities that are “presumed to conform” and the basis for the presumptions. The notice must clearly identify the type and size of the action that would be “presumed to conform” and provide criteria for determining if the type and size of action qualifies it for the presumption;

(2) The Federal agency must notify the appropriate EPA Regional Office(s), State, local, and tribal air quality agencies and, where applicable, the agency designated under section 174 of the Act and the MPO and provide at least 30 days for the public to comment on the list of proposed activities “presumed to conform.” If the “presumed to conform” action has regional or national application (e.g., the action will cause emission increases in excess of the de minimis levels identified in paragraph (b) of this section in more than one of EPA's Regions), the Federal agency, as an alternative to sending it to EPA Regional Offices, can send the draft conformity determination to U.S. EPA, Office of Air Quality Planning and Standards;

(3) The Federal agency must document its response to all the comments received and make the comments, response, and final list of activities available to the public upon request; and

(4) The Federal agency must publish the final list of such activities in the Federal Register.

(i) Emissions from the following actions are “presumed to conform”:

(1) Actions at installations with facility-wide emission budgets meeting the requirements in § 93.161 provided that the State or Tribe has included the emission budget in the EPA-approved SIP and the emissions from the action along with all other emissions from the installation will not exceed the facility-wide emission budget.

(2) Prescribed fires conducted in accordance with a smoke management program (SMP) which meets the requirements of EPA's Interim Air Quality Policy on Wildland and Prescribed Fires or an equivalent replacement EPA policy.

(3) Emissions for actions that the State or Tribe identifies in the EPA-approved SIP or TIP as “presumed to conform.”

(j) Even though an action would otherwise be “presumed to conform” under paragraph (f) or (i) of this section, an action shall not be “presumed to conform” and the requirements of § 93.150, § 93.151, §§ 93.154 through 93.160 and §§ 93.162 through 93.164 shall apply to the action if EPA or a third party shows that the action would:

(1) Cause or contribute to any new violation of any standard in any area;

(2) Interfere with provisions in the applicable SIP or TIP for maintenance of any standard;

(3) Increase the frequency or severity of any existing violation of any standard in any area; or

(4) Delay timely attainment of any standard or any required interim emissions reductions or other milestones in any area including, where applicable, emission levels specified in the applicable SIP or TIP for purposes of:

(i) A demonstration of reasonable further progress;

(ii) A demonstration of attainment; or

(iii) A maintenance plan.

(k) The provisions of this subpart shall apply in all nonattainment and maintenance areas except conformity requirements for newly designated nonattainment areas are not applicable until 1 year after the effective date of the final nonattainment designation for each NAAQS and pollutant in accordance with section 176(c)(6) of the Act.

Any department, agency, or instrumentality of the Federal government taking an action subject to this subpart must make its own conformity determination consistent with the requirements of this subpart. In making its conformity determination, a Federal agency must follow the requirements in §§ 93.155 through 93.160 and §§ 93.162 through 93.165 and must consider comments from any interested parties. Where multiple Federal agencies have jurisdiction for various aspects of a project, a Federal agency may choose to adopt the analysis of another Federal agency or develop its own analysis in order to make its conformity determination.

(a) A Federal agency making a conformity determination under §§ 93.154 through 93.160 and §§ 93.162 through 93.164 must provide to the appropriate EPA Regional Office(s), State and local air quality agencies, any federally-recognized Indian tribal government in the nonattainment or maintenance area, and, where applicable, affected Federal land managers, the agency designated under section 174 of the Act and the MPO, a 30-day notice which describes the proposed action and the Federal agency's draft conformity determination on the action. If the action has multi-regional or national impacts (e.g., the action will cause emission increases in excess of the de minimis levels identified in § 93.153(b) in three or more of EPA's Regions), the Federal agency, as an alternative to sending it to EPA Regional Offices, can provide the notice to EPA's Office of Air Quality Planning and Standards.

(b) A Federal agency must notify the appropriate EPA Regional Office(s), State and local air quality agencies, any federally-recognized Indian tribal government in the nonattainment or maintenance area, and, where applicable, affected Federal land managers, the agency designated under section 174 of the Clean Air Act and the MPO, within 30 days after making a final conformity determination under this subpart.

(c) The draft and final conformity determination shall exclude any restricted information or confidential business information. The disclosure of restricted information and confidential business information shall be controlled by the applicable laws, regulations, security manuals, or executive orders concerning the use, access, and release of such materials. Subject to applicable procedures to protect restricted information from public disclosure, any information or materials excluded from the draft or final conformity determination or supporting materials may be made available in a restricted information annex to the determination for review by Federal and State representatives who have received appropriate clearances to review the information.

(a) Upon request by any person regarding a specific Federal action, a Federal agency must make available, subject to the limitation in paragraph (e) of this section, for review its draft conformity determination under § 93.154 with supporting materials which describe the analytical methods and conclusions relied upon in making the applicability analysis and draft conformity determination.

(b) A Federal agency must make public its draft conformity determination under § 93.154 by placing a notice by prominent advertisement in a daily newspaper of general circulation in the area affected by the action and by providing 30 days for written public comment prior to taking any formal action on the draft determination. This comment period may be concurrent with any other public involvement, such as occurs in the National Environmental Policy Act (NEPA) process. If the action has multi-regional or national impacts (e.g., the action will cause emission increases in excess of the de minimis levels identified in § 93.153(b) in three or more of EPA's Regions), the Federal agency, as an alternative to publishing separate notices, can publish a notice in the Federal Register.

(c) A Federal agency must document its response to all the comments received on its draft conformity determination under § 93.154 and make the comments and responses available, subject to the limitation in paragraph (e) of this section, upon request by any person regarding a specific Federal action, within 30 days of the final conformity determination.

(d) A Federal agency must make public its final conformity determination under § 93.154 for a Federal action by placing a notice by prominent advertisement in a daily newspaper of general circulation in the area affected by the action within 30 days of the final conformity determination. If the action would have multi-regional or national impacts, the Federal agency, as an alternative, can publish the notice in the Federal Register.

(e) The draft and final conformity determination shall exclude any restricted information or confidential business information. The disclosure of restricted information and confidential business information shall be controlled by the applicable laws, regulations or executive orders concerning the release of such materials.

(a) Once a conformity determination is completed by a Federal agency, that determination is not required to be re-evaluated if the agency has maintained a continuous program to implement the action; the determination has not lapsed as specified in paragraph (b) of this section; or any modification to the action does not result in an increase in emissions above the levels specified in § 93.153(b). If a conformity determination is not required for the action at the time NEPA analysis is completed, the date of the finding of no significant impact (FONSI) for an Environmental Assessment, a record of decision (ROD) for an Environmental Impact Statement, or a categorical exclusion determination can be used as a substitute date for the conformity determination date.

(b) The conformity status of a Federal action automatically lapses 5 years from the date a final conformity determination is reported under § 93.155, unless the Federal action has been completed or a continuous program to implement the Federal action has commenced.

(c) Ongoing Federal activities at a given site showing continuous progress are not new actions and do not require periodic re-determinations so long as such activities are within the scope of the final conformity determination reported under § 93.155.

(d) If the Federal agency originally determined through the applicability analysis that a conformity determination was not necessary because the emissions for the action were below the limits in § 93.153(b) and changes to the action would result in the total emissions from the action being above the limits in § 93.153(b), then the Federal agency must make a conformity determination.

(a) An action required under § 93.153 to have a conformity determination for a specific pollutant, will be determined to conform to the applicable SIP if, for each pollutant that exceeds the rates in § 93.153(b), or otherwise requires a conformity determination due to the total of direct and indirect emissions from the action, the action meets the requirements of paragraph (c) of this section, and meets any of the following requirements:

(1) For any criteria pollutant or precursor, the total of direct and indirect emissions from the action are specifically identified and accounted for in the applicable SIP's attainment or maintenance demonstration or reasonable further progress milestone or in a facility-wide emission budget included in a SIP in accordance with § 93.161;

(2) For precursors of ozone, nitrogen dioxide, or PM, the total of direct and indirect emissions from the action are fully offset within the same nonattainment or maintenance area (or nearby area of equal or higher classification provided the emissions from that area contribute to the violations, or have contributed to violations in the past, in the area with the Federal action) through a revision to the applicable SIP or a similarly enforceable measure that effects emissions reductions so that there is no net increase in emissions of that pollutant;

(3) For any directly-emitted criteria pollutant, the total of direct and indirect emissions from the action meets the requirements:

(i) Specified in paragraph (b) of this section, based on areawide air quality modeling analysis and local air quality modeling analysis; or

(ii) Meet the requirements of paragraph (a)(5) of this section and, for local air quality modeling analysis, the requirement of paragraph (b) of this section;

(4) For CO or directly emitted PM—

(i) Where the State agency primarily responsible for the applicable SIP determines that an areawide air quality modeling analysis is not needed, the total of direct and indirect emissions from the action meet the requirements specified in paragraph (b) of this section, based on local air quality modeling analysis; or

(ii) Where the State agency primarily responsible for the applicable SIP determines that an areawide air quality modeling analysis is appropriate and that a local air quality modeling analysis is not needed, the total of direct and indirect emissions from the action meet the requirements specified in paragraph (b) of this section, based on areawide modeling, or meet the requirements of paragraph (a)(5) of this section; or

(5) For ozone or nitrogen dioxide, and for purposes of paragraphs (a)(3)(ii) and (a)(4)(ii) of this section, each portion of the action or the action as a whole meets any of the following requirements:

(i) Where EPA has approved a revision to the applicable implementation plan after the area was designated as nonattainment and the State or Tribe makes a determination as provided in paragraph (a)(5)(i)(A) of this section or where the State or Tribe makes a commitment as provided in paragraph (a)(5)(i)(B) of this section:

(A) The total of direct and indirect emissions from the action (or portion thereof) is determined and documented by the State agency primarily responsible for the applicable SIP to result in a level of emissions which, together with all other emissions in the nonattainment (or maintenance) area, would not exceed the emissions budgets specified in the applicable SIP;

(B) The total of direct and indirect emissions from the action (or portion thereof) is determined by the State agency responsible for the applicable SIP to result in a level of emissions which, together with all other emissions in the nonattainment (or maintenance) area, would exceed an emissions budget specified in the applicable SIP and the State Governor or the Governor's designee for SIP actions makes a written commitment to EPA which includes the following:

(1) A specific schedule for adoption and submittal of a revision to the SIP which would achieve the needed emission reductions prior to the time emissions from the Federal action would occur;

(2) Identification of specific measures for incorporation into the SIP which would result in a level of emissions which, together with all other emissions in the nonattainment or maintenance area, would not exceed any emissions budget specified in the applicable SIP;

(3) A demonstration that all existing applicable SIP requirements are being implemented in the area for the pollutants affected by the Federal action, and that local authority to implement additional requirements has been fully pursued;

(4) A determination that the responsible Federal agencies have required all reasonable mitigation measures associated with their action; and

(5) Written documentation including all air quality analyses supporting the conformity determination;

(C) Where a Federal agency made a conformity determination based on a State's or Tribe's commitment under paragraph (a)(5)(i)(B) of this section and the State has submitted a SIP or TIP to EPA covering the time period during which the emissions will occur or is scheduled to submit such a SIP or TIP within 18 months of the conformity determination, the State commitment is automatically deemed a call for a SIP or TIP revision by EPA under section 110(k)(5) of the Act, effective on the date of the Federal conformity determination and requiring response within 18 months or any shorter time within which the State or Tribe commits to revise the applicable SIP;

(D) Where a Federal agency made a conformity determination based on a State or tribal commitment under paragraph (a)(5)(i)(B) of this section and the State or Tribe has not submitted a SIP covering the time period when the emissions will occur or is not scheduled to submit such a SIP within 18 months of the conformity determination, the State or Tribe must, within 18 months, submit to EPA a revision to the existing SIP committing to include the emissions in the future SIP revision.

(ii) The action (or portion thereof), as determined by the MPO, is specifically included in a current transportation plan and transportation improvement program which have been found to conform to the applicable SIP under 40 CFR part 51, subpart T, or 40 CFR part 93, subpart A;

(iii) The action (or portion thereof) fully offsets its emissions within the same nonattainment or maintenance area (or nearby area of equal or higher classification provided the emissions from that area contribute to the violations, or have contributed to violation in the past, in the area with the Federal action) through a revision to the applicable SIP or an equally enforceable measure that effects emissions reductions equal to or greater than the total of direct and indirect emissions from the action so that there is no net increase in emissions of that pollutant;

(iv) Where EPA has not approved a revision to the relevant SIP since the area was designated or reclassified, the total of direct and indirect emissions from the action for the future years (described in § 93.159(d)) do not increase emissions with respect to the baseline emissions:

(A) The baseline emissions reflect the historical activity levels that occurred in the geographic area affected by the proposed Federal action during:

(1) The most current calendar year with a complete emission inventory available before an area is designated unless EPA sets another year; or

(2) The emission budget in the applicable SIP;

(3) The year of the baseline inventory in the PM-10 applicable SIP;

(B) The baseline emissions are the total of direct and indirect emissions calculated for the future years (described in § 93.159(d)) using the historic activity levels (described in paragraph (a)(5)(iv)(A) of this section) and appropriate emission factors for the future years; or

(v) Where the action involves regional water and/or wastewater projects, such projects are sized to meet only the needs of population projections that are in the applicable SIP.

(b) The areawide and/or local air quality modeling analyses must:

(1) Meet the requirements in § 93.159; and

(2) Show that the action does not:

(i) Cause or contribute to any new violation of any standard in any area; or

(ii) Increase the frequency or severity of any existing violation of any standard in any area.

(c) Notwithstanding any other requirements of this section, an action subject to this subpart may not be determined to conform to the applicable SIP unless the total of direct and indirect emissions from the action is in compliance or consistent with all relevant requirements and milestones contained in the applicable SIP, such as elements identified as part of the reasonable further progress schedules, assumptions specified in the attainment or maintenance demonstration, prohibitions, numerical emission limits, and work practice requirements.

(d) Any analyses required under this section must be completed, and any mitigation requirements necessary for a finding of conformity must be identified before the determination of conformity is made.

(a) The analyses required under this subpart must be based on the latest planning assumptions.

(1) All planning assumptions must be derived from the estimates of population, employment, travel, and congestion most recently approved by the MPO, or other agency authorized to make such estimates, where available.

(2) Any revisions to these estimates used as part of the conformity determination, including projected shifts in geographic location or level of population, employment, travel, and congestion, must be approved by the MPO or other agency authorized to make such estimates for the urban area.

(b) The analyses required under this subpart must be based on the latest and most accurate emission estimation techniques available as described below, unless such techniques are inappropriate. If such techniques are inappropriate, the Federal agency may obtain written approval from the appropriate EPA Regional Administrator for a modification or substitution, of another technique on a case-by-case basis or, where appropriate, on a generic basis for a specific Federal agency program.

(1) For motor vehicle emissions, the most current version of the motor vehicle emissions model specified by EPA and available for use in the preparation or revision of SIPs in that State must be used for the conformity analysis as specified in paragraphs (b)(1)(i) and (ii) of this section:

(i) The EPA must publish in the Federal Register a notice of availability of any new motor vehicle emissions model; and

(ii) A grace period of 3 months shall apply during which the motor vehicle emissions model previously specified by EPA as the most current version may be used unless EPA announces a longer grace period in the Federal Register. Conformity analyses for which the analysis was begun during the grace period or no more than 3 months before the Federal Register notice of availability of the latest emission model may continue to use the previous version of the model specified by EPA.

(2) For non-motor vehicle sources, including stationary and area source emissions, the latest emission factors specified by EPA in the “Compilation of Air Pollutant Emission Factors” (AP-42, http://www.epa.gov/ttn/chiefs/efpac) must be used for the conformity analysis unless more accurate emission data are available, such as actual stack test data from the stationary sources which are part of the conformity analysis.

(c) The air quality modeling analyses required under this subpart must be based on the applicable air quality models, data bases, and other requirements specified in the most recent version of the “Guideline on Air Quality Models.” (Appendix W to 40 CFR part 51).

(1) The guideline techniques are inappropriate, in which case the model may be modified or another model substituted on a case-by-case basis or, where appropriate, on a generic basis for a specific Federal agency program; and

(2) Written approval of the EPA Regional Administrator is obtained for any modification or substitution.

(d) The analyses required under this subpart must be based on the total of direct and indirect emissions from the action and must reflect emission scenarios that are expected to occur under each of the following cases:

(1) The attainment year specified in the SIP, or if the SIP does not specify an attainment year, the latest attainment year possible under the Act; or

(2) The last year for which emissions are projected in the maintenance plan;

(3) The year during which the total of direct and indirect emissions from the action is expected to be the greatest on an annual basis; and

(4) Any year for which the applicable SIP specifies an emissions budget.

(a) Any measures that are intended to mitigate air quality impacts must be identified and the process for implementation and enforcement of such measures must be described, including an implementation schedule containing explicit timelines for implementation.

(b) Prior to determining that a Federal action is in conformity, the Federal agency making the conformity determination must obtain written commitments from the appropriate persons or agencies to implement any mitigation measures which are identified as conditions for making conformity determinations.

(c) Persons or agencies voluntarily committing to mitigation measures to facilitate positive conformity determinations must comply with the obligations of such commitments.

(d) In instances where the Federal agency is licensing, permitting or otherwise approving the action of another governmental or private entity, approval by the Federal agency must be conditioned on the other entity meeting the mitigation measures set forth in the conformity determination.

(e) When necessary because of changed circumstances, mitigation measures may be modified so long as the new mitigation measures continue to support the conformity determination. Any proposed change in the mitigation measures is subject to the reporting requirements of § 93.156 and the public participation requirements of § 93.157.

(f) Written commitments to mitigation measures must be obtained prior to a positive conformity determination and such commitments must be fulfilled.

(g) After a State or Tribe revises its SIP or TIP and EPA approves that SIP revision, any agreements, including mitigation measures, necessary for a conformity determination will be both State or tribal and federally enforceable. Enforceability through the applicable SIP or TIP will apply to all persons who agree to mitigate direct and indirect emissions associated with a Federal action for a conformity determination.

(a) The State, local or tribal agency responsible for implementing and enforcing the SIP or TIP can in cooperation with Federal agencies or third parties authorized by the agency that operate installations subject to Federal oversight develop and adopt a facility-wide emission budget to be used for demonstrating conformity under § 93.158(a)(1). The facility-wide budget must meet the following criteria:

(1) Be for a set time period;

(2) Cover the pollutants or precursors of the pollutants for which the area is designated nonattainment or maintenance;

(3) Include specific quantities allowed to be emitted on an annual or seasonal basis;

(4) The emissions from the facility along with all other emissions in the area will not exceed the emission budget for the area;

(5) Include specific measures to ensure compliance with the budget, such as periodic reporting requirements or compliance demonstration, when the Federal agency is taking an action that would otherwise require a conformity determination;

(6) Be submitted to EPA as a SIP revision;

(7) The SIP revision must be approved by EPA.

(b) The facility-wide budget developed and adopted in accordance with paragraph (a) of this section can be revised by following the requirements in paragraph (a) of this section.

(c) Total direct and indirect emissions from Federal actions in conjunction with all other emissions subject to General Conformity from the facility that do not exceed the facility budget adopted pursuant to paragraph (a) of this section are “presumed to conform” to the SIP and do not require a conformity analysis.

(d) If the total direct and indirect emissions from the Federal actions in conjunction with the other emissions subject to General Conformity from the facility exceed the budget adopted pursuant to paragraph (a) of this section, the action must be evaluated for conformity. A Federal agency can use the compliance with the facility-wide emissions budget as part of the demonstration of conformity, i.e., the agency would have to mitigate or offset the emissions that exceed the emission budget.

(e) If the SIP for the area includes a category for construction emissions, the negotiated budget can exempt construction emissions from further conformity analysis.

If a Federal action would result in total direct and indirect emissions above the applicable thresholds which would be emitted beyond the time period covered by the SIP, the Federal agency can:

(a) Demonstrate conformity with the last emission budget in the SIP; or

(b) Request the State or Tribe to adopt an emissions budget for the action for inclusion in the SIP. The State or Tribe must submit a SIP or TIP revision to EPA within 18 months either including the emissions in the existing SIP or establishing an enforceable commitment to include the emissions in future SIP revisions based on the latest planning assumptions at the time of the SIP revision. No such commitment by a State or Tribe shall restrict a State's or Tribe's ability to require RACT, RACM or any other control measures within the State's or Tribe's authority to ensure timely attainment of the NAAQS.

(a) The emissions reductions from an offset or mitigation measure used to demonstrate conformity must occur during the same calendar year as the emission increases from the action except, as provided in paragraph (b) of this section.

(b) The State or Tribe may approve emissions reductions in other years provided:

(1) The reductions are greater than the emission increases by the following ratios:

(2) The time period for completing the emissions reductions must not exceed twice the period of the emissions.

(3) The offset or mitigation measure with emissions reductions in another year will not:

(i) Cause or contribute to a new violation of any air quality standard,

(ii) Increase the frequency or severity of any existing violation of any air quality standard; or

(iii) Delay the timely attainment of any standard or any interim emissions reductions or other milestones in any area.

(c) The approval by the State or Tribe of an offset or mitigation measure with emissions reductions in another year does not relieve the State or Tribe of any obligation to meet any SIP or Clean Air Act milestone or deadline. The approval of an alternate schedule for mitigation measures is at the discretion of the State or Tribe, and they are not required to approve an alternate schedule.

Federal agencies must reduce the same type of pollutant as being increased by the Federal action except the State or Tribe may approve offsets or mitigation measures of different precursors of the same criteria pollutant, if such trades are allowed by a State or Tribe in a SIP or TIP approved NSR regulation, is technically justified, and has a demonstrated environmental benefit.

(a) Federal facilities and installations subject to Federal oversight can, with the approval of the State or tribal agency responsible for the SIP or TIP in that area, create an early emissions reductions credit program. The Federal agency can create the emission reduction credits in accordance with the requirements in paragraph (b) of this section and can use them in accordance with paragraph (c) of this section.

(b) Creation of emission reduction credits.

(1) Emissions reductions must be quantifiable through the use of standard emission factors or measurement techniques. If non-standard factors or techniques to quantify the emissions reductions are used, the Federal agency must receive approval from the State or tribal agency responsible for the implementation of the SIP or TIP and from EPA's Regional Office. The emission reduction credits do not have to be quantified before the reduction strategy is implemented, but must be quantified before the credits are used in the General Conformity evaluation.

(2) The emission reduction methods must be consistent with the applicable SIP or TIP attainment and reasonable further progress demonstrations.

(3) The emissions reductions cannot be required by or credited to other applicable SIP or TIP provisions.

(4) Both the State or Tribe and Federal air quality agencies must be able to take legal action to ensure continued implementation of the emission reduction strategy. In addition, private citizens must also be able to initiate action to ensure compliance with the control requirement.

(5) The emissions reductions must be permanent or the timeframe for the reductions must be specified.

(6) The Federal agency must document the emissions reductions and provide a copy of the document to the State or tribal air quality agency and the EPA regional office for review. The documentation must include a detailed description of the emission reduction strategy and a discussion of how it meets the requirements of paragraphs (b)(1) through (5) of this section.

(c) Use of emission reduction credits. The emission reduction credits created in accordance with paragraph (b) of this section can be used, subject to the following limitations, to reduce the emissions increase from a Federal action at the facility for the conformity evaluation.

(1) If the technique used to create the emission reduction is implemented at the same facility as the Federal action and could have occurred in conjunction with the Federal action, then the credits can be used to reduce the total direct and indirect emissions used to determine the applicability of the regulation as required in § 93.153 and as offsets or mitigation measures required by § 93.158.

(2) If the technique used to create the emission reduction is not implemented at the same facility as the Federal action or could not have occurred in conjunction with the Federal action, then the credits cannot be used to reduce the total direct and indirect emissions used to determine the applicability of the regulation as required in § 93.153, but can be used to offset or mitigate the emissions as required by § 93.158.

(3) Emissions reductions credits must be used in the same year in which they are generated.

(4) Once the emission reduction credits are used, they cannot be used as credits for another conformity evaluation. However, unused credits from a strategy used for one conformity evaluation can be used for another conformity evaluation as long as the reduction credits are not double counted.

(5) Federal agencies must notify the State or tribal air quality agency responsible for the implementation of the SIP or TIP and EPA Regional Office when the emission reduction credits are being used.