Air and Radiation EPA420-B-04-017

November 2004

Conformity SIP Guidance
EPA420-B-04-017

November 2004

Conformity SIP Guidance

Transportation and Regional Programs Division

Office of Transportation and Air Quality

U.S. Environmental Protection Agency
EPA Conformity SIP Guidance November 18, 2004 

Conformity SIP Guidance 

Introduction 

This document provides guidance on the requirement that states adopt their own criteria 

and procedures for determining transportation conformity; these state conformity rules 

are known as “conformity SIPs.” Where EPA has approved a state’s conformity SIP, the 

approved conformity SIP governs conformity determinations instead of the federal rule, 

for those aspects of the rule that it addresses. 

EPA recently published a new final rule for transportation conformity on July 1, 2004 (69 

FR 40004). This guidance document will help areas that have approved conformity SIPs 

know which provisions of the July 1, 2004, conformity rule amendments apply 

immediately in their areas, and which provisions cannot apply until their conformity SIPs 

are revised. In addition, this guidance document includes questions and answers on other 

aspects of conformity SIPs. 

1. Q. How is this guidance organized? 

A. This document is organized by questions and answers under the following 

headings: 

• Introduction (Q&A 1 - 4). 

•	 Applying the July 1, 2004, Transportation Conformity Rule (Q&A 5 - 11). 

This section includes Q & As that specifically address what aspects of the July 

1, 2004, transportation conformity rule (69 FR 40004) apply in areas with and 

without conformity SIPs, and other questions regarding that rulemaking. 

•	 New 8-hour Ozone and PM2.5 Standards (Q&A 12 & 13). These two 

questions specifically address areas designated nonattainment under the new 

air quality standards. 

•	 General Questions About Conformity SIPs (Q&A 14 - 18). This section 

includes Q & As about using a Memorandum of Agreement or Memorandum 

of Understanding for a conformity SIP, incorporating the rule by reference, 

whether existing conformity SIPs apply to new areas, and which parts of the 

conformity rule need to be tailored for specific areas. 

This document also includes an appendix: 

•	 Appendix A is a table that indicates whether a new federal rule provision 

applies in areas with approved conformity SIPs. 

2. Q. Does this guidance create new policy? 

A. No, this guidance does not create new policy, it merely explains the current 

conformity SIP requirements in the conformity rule at 40 CFR Subpart T, codified at 

40 CFR 51.390. This portion of the conformity regulation was published in the 

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EPA Conformity SIP Guidance November 18, 2004 

August 15, 1997, conformity rule (62 FR 43801). In addition, the July 1, 2004, 

conformity rule includes a discussion of conformity SIPs, at 69 FR 40068. 

3. Q. Who can I contact for additional questions regarding conformity SIPs? 

A. If this guidance document does not answer a specific question, please contact the 

transportation conformity staff person responsible for your state at the appropriate 

EPA Regional Headquarters Office. A listing of Regional Offices, the states they 

cover, and contact information for the EPA Regional conformity staff people can be 

found at the following website: 

http://www.epa.gov/otaq/transp/conform/contacts.htm 

For questions of a general nature about conformity SIPs, please contact: 

Laura Berry, berry.laura@epa.gov , 734-214-4858; or 

Rudy Kapichak, kapichak.rudolph@epa.gov , 734-214-4574. 

4. Q. How can I find out if a conformity SIP applies in my area? 

A. Please contact the transportation conformity staff person at the appropriate EPA 

Regional Office (see previous Q & A for the website that lists these staff people). 

This staff person will have the most up-to-date information regarding the status of a 

specific state or area’s approved or submitted conformity SIP. 

Applying the July 1, 2004, Transportation Conformity Rule 

5. Q. Do the provisions of the July 1, 2004, transportation conformity rule (69 FR 

40004; “July 2004 rule”) apply in states without approved conformity SIPs? What if 

the SIP has been submitted to EPA but has not been approved? 

A. All of the provisions contained in the July 2004 conformity rule apply upon the 

effective date of EPA’s rulemaking in states without previously approved conformity 

SIPs, including those states that have submitted SIPs that have not been approved by 

EPA. 

6. Q. Does the July 2004 rule apply if a state has a state conformity rule under which it 

has been operating, but which has not been approved by EPA into the SIP? 

A. Yes. If a state’s conformity rule has not been approved by EPA as a conformity 

SIP (note that a conformity SIP could also take the form of a Memorandum of 

Understanding (MOU) or Memorandum of Agreement (MOA), see Q&A 14 and 15, 

below), then the state does not have an approved conformity SIP. In this case, all of 

the July 2004 rule changes apply. 

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EPA Conformity SIP Guidance November 18, 2004 

7. Q. What portions of the July 2004 conformity rule apply in areas that have approved 

conformity SIPs? 

A. The answer to this question is found in Appendix A for each section of the 

conformity rule. The table indicates which conformity rulemaking finalized each 

specific section and briefly indicates how the provision changed as a result of the July 

2004 rulemaking. The last column of the table answers whether the July 2004 rule 

changes apply in areas with approved conformity SIPs. 

There are three possible answers to whether a provision applies and though we have 

provided general examples for each of these three answers, readers should not rely on 

these generalizations. States should thoroughly consider all the information provided 

in the table for each specific provision, in conjunction with review of the specifics of 

the particular state conformity rule. 

The three possible answers to whether or not a provision of the July 2004 rule applies 

are as follows: 

(1) Yes, the change applies. The answer is yes, for example, for all provisions that 

address the new air quality standards or the March 2, 1999, conformity court decision. 

(2) No, the change does not apply. The answer is no for major changes that are not 

the result of either the new air quality standards or the court decision. Such 

provisions cannot apply until the conformity SIP is revised to include it. 

(3) States can interpret their existing rules consistent with the July 2004 rule so 

that the substance of the new rule applies. However, specific language of the 

July 2004 rule clearly does not apply until SIPs are changed. This statement is 

the answer in the table for some types of minor clarifications, such as when 

references have been updated by the July 2004 rule. In addition, this statement 

applies in other situations, such as when the July 2004 rule added a pre-existing 

interpretation or policy into the rule for the purpose of codifying it. EPA believes that 

where changes merely codify an interpretation of the prior conformity regulations or 

change a reference without changing the requirement, states can and may want to 

interpret their existing conformity regulations consistent with the interpretation as 

EPA had done under the previous federal rule. Note, although a state is not 

compelled to interpret their conformity SIP in the same way as the July 2004 rule, 

some pre-existing or current EPA policy interpretations may still apply to their 

conformity SIP. The decision to interpret a conformity SIP in the same way as the 

July 2004 regulation should be made within interagency consultation process. 

8. Q. Does a provision in the July 2004 conformity rule apply if a state has an approved 

conformity SIP, but it does not address that particular section? 

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EPA Conformity SIP Guidance November 18, 2004 

A. If a conformity SIP does not include a complete section (i.e., an entire numbered 

portion, such as §93.106 or §93.122) then that section of the federal rule applies in 

that state. Therefore, if any section of the conformity rule is missing from a state’s 

conformity SIP, that section as amended by the July 2004 rule applies immediately. 

However, if a state conformity SIP includes a particular section, then the state is still 

considered to have a rule addressing that section. In such cases, whether or not the 

new federal provision can apply immediately will depend on the specific section and 

nature of the change at issue. As discussed above, the Appendix A table indicates 

whether or not a specific July 2004 amendment or addition in such a section can 

apply in these circumstances. 

9. Q. Can EPA approve a state conformity SIP that is based on an earlier version of the 

conformity rule rather than the July 2004 conformity rule? 

A: EPA can only approve SIPs that meet the regulations as updated by the July 2004 

rule. Some provisions of the July 2004 rule change requirements from the previous 

version of the rule. Areas should include these new provisions in their conformity 

SIPs in accordance with 40 CFR 51.390. EPA regions can only approve conformity 

SIPs that address the current rule’s requirements, including the 2004 rule revisions. 

10. Q. What changes in the July 2004 rule that are not the result of either the new air 

quality standards or the court decision could make the most difference to areas that 

have approved conformity SIPs? 

A. Among the updates EPA made to the rule that are not the result of either the new 

air quality standards or the court decision, two stand out as those that could have the 

greatest impact on how conformity is done. First, EPA has streamlined the frequency 

requirements in §93.104 in the August 2002 and July 2004 rulemakings. States with 

approved conformity SIPs that do not include these changes may be required to make 

conformity determinations sooner and more frequently than the federal rule now 

requires. Specifically, state conformity SIPs may contain the requirement found in 

the August 1997 rule to determine conformity within 18 months of submission of a 

SIP that includes budgets, rather than within 18 months of EPA’s adequacy finding 

for budgets in a submitted SIP. Another example is that state conformity SIPs may 

contain the requirement to determine conformity within 18 months of EPA’s approval 

of any SIP that contains budgets found in the August 1997 rule, but the updated 

federal rule requires a conformity determination in this case only if those budgets 

have not already been used in a conformity determination. 

The second rule change that stands out is the update to the latest planning 

assumptions requirement in §93.110. Under the updated federal rule, areas can 

determine conformity based on the latest planning assumptions that are available at 

the time the conformity analysis begins. However, areas with approved conformity 

SIPs that include §93.110 as it existed in the August 1997 rule must use the latest 

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EPA Conformity SIP Guidance November 18, 2004 

planning assumptions that are available at the time DOT makes its conformity 

determination. Areas may want to update their SIPs quickly to take advantage of 

these two rule changes as well as others made in the July 2004 rule. 

11. Q. Can EPA expedite a state’s conformity SIP revision so that an area could take 

advantage of the changes in the July 2004 rule that are not the result of either the new 

air quality standards or the court decision as soon as possible? 

A. Yes. EPA will work with states to approve conformity SIP revisions as 

expeditiously as possible by using approaches such as parallel processing or direct 

final rulemaking, so that areas can then take advantage of all of the amendments 

included in the July 2004 rule and subsequent rulemakings. 

12. Q. Are two conformity SIP revisions required for areas designated for both the 8-

hour ozone standard and the PM2.5 standard? 

A. Not necessarily; states may be able to address all conformity rule provisions 

within the same conformity SIP. The July 2004 conformity rule includes criteria and 

procedures for determining conformity for the 8-hour ozone standard, as well as for 

the PM2.5 standard. However, there are two conformity requirements for the PM2.5 

standard that were not addressed in July 2004 rule: PM2.5 hot-spot requirements, and 

requirements for addressing PM2.5 precursors in transportation conformity 

determinations. EPA intends to publish a supplemental notice of proposed 

rulemaking in the near future to request additional comment on options related to 

PM2.5 and PM10 hot-spot requirements. EPA intends to finalize both the hot-spot 

requirements and the requirements for addressing PM2.5 precursors as soon as 

possible; we anticipate these final rules to be completed in 2005. 

State and local agencies can consider addressing the July 2004 rule amendments and 

the upcoming PM2.5 rule requirements within the same conformity SIP revision, to the 

extent possible given the requirements in §51.390, to minimize the work involved in 

creating or revising the conformity SIP. However, the drawback of this approach for 

a state with an approved conformity SIP is that it may need to wait longer before it 

can apply some of the provisions of the July 2004 rule (see Q&A 7, and Appendix A). 

If states decide to address all provisions in one conformity SIP, states should make 

sure that the conformity SIP includes the consultation procedures that apply 

specifically in PM2.5 areas as well as in ozone areas. 

State and local agencies should keep in mind that any federal rule provisions that 

specifically address the new standards, whether they are included in the July 2004 

final rule or an upcoming rulemaking, apply upon the federal rule’s effective date for 

all areas that determine conformity. Therefore, the PM2.5 hot-spot and precursor 

requirements will apply upon the effective date of EPA’s final rule published in the 

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EPA Conformity SIP Guidance November 18, 2004 

Federal Register, even if an area has already updated its conformity SIP to include 

the July 2004 final rule. 

13. Q. If a state has consultation procedures that refer to general types of agencies (e.g., 

MPOs) rather than specific agencies (e.g., an MPO for a specific area), do the 

provisions of the conformity SIP apply for new or expanded nonattainment areas? 

A. As indicated previously, the answer depends on the wording of the conformity 

SIP itself. If the SIP’s wording could be interpreted to include expanded or new 

nonattainment areas in the state, the provisions of the conformity SIP would apply to 

these areas. However, if the conformity SIP includes wording that limits its 

applicability to particular areas, then it may not apply to new or expanded areas. If 

your state has an approved conformity SIP and you are unsure whether or not it 

applies to your particular area, please consult with your EPA Regional Office (see 

Q&A 3 for where to find contact information). 

General Questions About Conformity SIPs 

14. Q. In what part of the regulations is the requirement for conformity SIPs found? 

A. The regulations that explain the requirements for a conformity SIP are found in 40 

CFR Part 51, subpart T, at 40 CFR 51.390. This portion of the conformity regulation 

was published in the August 15, 1997, conformity rule (62 FR 43801). In addition, 

the July 1, 2004, conformity rule includes a discussion of conformity SIPs, at 69 FR 

40068. 

15. Q. What are the requirements for conformity SIP MOUs and MOAs? 

A. Some states use a memorandum of understanding (MOU) or memorandum of 

agreement (MOA) to include the criteria and procedures of the conformity rule 

instead of a state regulation. Some states have used MOUs and MOAs to codify their 

consultation procedures, and have used a SIP revision to codify the remainder of the 

rule. In either case, a state can use an MOU or MOA if such a memo meets the 

following requirements: 

a) it is fully enforceable under state law against all parties involved in interagency 

consultation and in approving, adopting and implementing transportation projects, 

TIPs, or transportation plans (see d below for how this is done). 

b) it is submitted for inclusion in the SIP, and 

c) it has been signed by all agencies that are covered by the conformity rule, 

including federal agencies and the recipients of funds designated under title 23 

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EPA Conformity SIP Guidance November 18, 2004 

U.S.C. or the Federal Transit Laws (see the definition in §93.101). For example, 

MOU signers would include MPOs, local and state air agencies, state DOTs, 

transit agencies, FHWA, FTA, and EPA, and all current recipients of federal 

surface transportation funds, both public and private. 

In addition, a state rule must be adopted which: 

d) requires all future parties covered by the rule, including new recipients of funds 

designated under title 23 U.S.C. or the Federal Transit Laws, to sign the MOU. 

16. Q. If a state wants to revise its MOU, must it be done through the SIP process, or 

can the state just have everyone sign a new MOU? 

A: An MOU revision would have to be approved through the SIP process because 

the MOU is part of the SIP. 

17. Q. If a state has prepared its conformity SIP by incorporating the federal rule into 

the SIP by reference rather than repeating the rule verbatim, do the changes made to 

the federal rule automatically apply in that state, or does the state still have to update 

the conformity SIP to take advantage of changes to the federal rule? 

A. The answer depends on what the conformity SIP indicates: 

•	 If a state incorporates the federal rule into its SIP by reference, it may have 

incorporated the federal rule that existed as of the date of the incorporation. If 

so, subsequent updates to the federal rule do not automatically apply and a 

revision to the conformity SIP must be submitted within 12 months of a 

change to the federal rule. 

•	 However, a conformity SIP that incorporates the federal rule by reference 

could also indicate that it also incorporates by reference any future changes 

made to the federal rule, although this is rare. In this case, the conformity SIP 

does not need to be revised when the federal conformity rule is updated. 

If your state has an approved conformity SIP that incorporates the rule by reference, 

and you are unsure about whether or not it also includes all future changes to the 

federal rule, please consult with your EPA Regional Office (see Q&A 3 for where to 

find contact information). 

18. Q. What sections of a state’s conformity SIP should be tailored for a specific area? 

A. Section 51.390(d) states that a conformity SIP must address all requirements of 

part 93, subpart A (e.g., all provisions of the conformity rule). In preparing 

transportation conformity SIPs, states can either adopt the language of the federal 

conformity rule verbatim or incorporate the rule into their SIP by reference. 

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EPA Conformity SIP Guidance November 18, 2004 

However, there are some parts of the rule that either must be tailored in order to make 

them enforceable, or could be tailored to improve readability. These provisions are as 

follows: 

Section 93.105: This section requires the adoption of area-specific consultation 

procedures. By definition, these procedures must be developed by local agencies 

in consultation with state and federal agencies. It is important that the state’s 

consultation procedures are clearly defined and enforceable. 

Several sections of the conformity rule include references to §93.105. If a state 

adopts these references verbatim, EPA could still approve the conformity SIP. 

Regardless of the cross-references, the state’s consultation section would exist 

and explain how and when agencies should consult. However, if the state has the 

ability to change the §93.105 references, doing so would help to clarify their rule. 

The state can either change the reference in each section to reflect the proper state 

rule’s reference, or include a generic provision in the SIP that says that “federal 

rule references to §93.105 correspond to §**** in the SIP.” 

Section 93.112: The second sentence in this section can be omitted from a state 

conformity SIP, because this language is not relevant once a conformity SIP is 

approved. However, a state could include this sentence without negative 

consequences. 

Section 93.119(d)(2): This provision is required to be adopted verbatim. But, if a 

PM10 area “defines the baseline emissions...to be those occurring in a different 

calendar year for which a baseline emissions inventory was developed for the 

purpose of developing a control strategy implementation plan,” then the 

conformity SIP should specify the baseline year here. An NO2 area could choose 

either to include this additional PM10 area-specific language verbatim, or delete 

everything after “calendar year 1990” in order to make it more readable. Either 

choice will not change the enforceability of this section. 

Section 93.122(a)(4)(ii): This provision stipulates that the conformity SIP 

submission must require that written commitments to implement control measures 

be obtained prior to conformity determinations and that the commitments be 

fulfilled. The following is example language that could be substituted in the 

conformity SIP for 93.122(a)(4)(ii): 

“Written commitments to control measures that are not included in the 

transportation plan and TIP must be obtained prior to a conformity 

determination and such commitments must be fulfilled.” 

However, if a state has already developed its conformity SIP and included the 

federal rule’s language for §93.119(d)(2), it would still be enforceable. 

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EPA Conformity SIP Guidance November 18, 2004 

Section 93.125(c): This provision is similar to 93.122(a)(4)(ii) and states that the 

SIP submission must require that written commitments for mitigation measures be 

obtained before conformity determinations are made and such commitments must 

be met. The following is example language that could be substituted in the 

conformity SIP for 93.125(c): 

“Written commitments to mitigation measures must be obtained prior to a 

positive conformity determination and project sponsors must comply with 

such commitments.” 

However, if a state has already developed its conformity SIP without adapting 

§93.125(c) and submitted it to EPA, this provision would still be enforceable. 

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EPA Conformity SIP Guidance November 18, 2004 

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EPA Conformity SIP Guidance November 18, 2004 

Appendix A: What Provisions of the Conformity Rule Apply in Areas with Conformity S

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

51.390 Implementation plan revision. 

August 1997 rule: This provision is not included in conformity SIPs 

(N/A) 

93.100 Purpose. August 1997 rule; not changed in July 2004 rule (N/A) 93.101 Definitions. August 1997 rule for majority of definitions, except the 

following: July 2004 rule additions: 

• 1-hour ozone NAAQS 

• 8-hour ozone NAAQS • Donut areas • Isolated rural nonattainment and maintenance areas. • Limited maintenance plan 

July 2004 rule clarifications: • Control strategy implementation plan revision 

• Milestone 

Yes for the newly added July 2004 defi

• 1-hour ozone NAAQS • 8-hour ozone NAAQS • Donut areas • Isolated rural nonattainment and m• Limited maintenance plan These definitions apply immediately be

includes them. 

For the July 2004 clarified definitions: 

• Control strategy implementation pl

• Milestone States can interpret their existing rules c

the July 2004 rule. However, the speci

clearly does not apply until SIPs are ch

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EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.102 Applicability. August 1997 rule, except the following 

August 2002 rule addition: 

(d) added one-year grace period provision, as a result of 

CAA amendment which applied immediately 

July 2004 rule additions: 

(b)(1) PM2.5 added to list of pollutants 

(b)(3) road dust for PM2.5 areas 

(c) requires currently conforming plan and TIP for project 

phase approvals 

(d) PM2.5 areas added to grace period provision 

July 2004 rule clarification: 

(b)(2)(iii) clarified only; no practical change 

Yes for the August 2002 rule addition: 

(d). This provision applies immedia

the statute, which applies as a matter 

Yes for the July 2004 rule additions in t

(b)(1): new standards (b)(3): new standards (c): court decision (d): new standards 

These provisions apply immediately, be

standards or court decision. 

For the July 2004 clarification: 

(b)(2)(iii) 

States can interpret their existing rules c

so that the substance of the new rule apof the July 2004 clearly does not apply 

93.103 Priority. August 1997 rule-- not changed in July 2004 rule (N/A) 

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EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.104 Frequency of conformity 

determinations. 

*Note: By “old,” we mean a 

provision as it existed in the CFR as 

of the August 1997 rulemaking. 

“Old” provisions have either been deleted or renumbered. 

By “new,” we mean a provision that has been updated or added by the 

July 2004 rulemaking. 

August 1997 rule, except the following: 

August 2002 rule revision: 

Old* (e)(2): provision changed so 18-month clock starts 

upon EPA’s adequacy finding instead of SIP submission 

July 2004 rule revisions and deletions: 

Old (c)(4) deleted; this was the requirement to determine 

conformity of the TIP within 6 months of the plan Old (e)(1) deleted; this was the 18-month trigger for 

November 1993 date 

Old (e)(3) revised so that 18-month clock for SIP 

approvals applies only if budgets not already used 

Old (e)(4) deleted; this was the 18-month trigger for TCM 

changes Old (e)(5) revised so that a FIP change to a TCM does not 

trigger an 18-month clock 

July 2004 rule renumbering: 

Old (e)(2) Æ new (e)(1) Old (e)(3) Æ new (e)(2), revised as noted above Old (e)(5) Æ new (e)(3), revised as noted above 

July 2004 rule clarifications: 

(b)(3) clarified only; no practical change 

(c)(3) clarified only; no practical change (d) clarified and combined provisions; no practical change 

No for the following August 2002 and J

Old (c)(4), 

Old (e)(1), Old (e)(2), (updated by August 2002 

Old (e)(3) Old (e)(4), and Old (e)(5) 

These provisions continue to apply in s

SIPs that include them, because revisio

related to the new standards or court deFor July 2004 clarifications: 

(b)(3), (c)(3), and (d), 

States can interpret their existing rules c

so that the substance of the new rule ap

language of the July 2004 rule clearly d

changed. Although these provisions ha

has been EPA’s existing policy, which 

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EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.105 Consultation. August 1997 rule, except 

July 2004: 

(c)(1)(vii): minor nonsubstantive change to update a 

reference 

For (c)(1)(vii): States can interpret their existing rules c

so that the substance of the new rule ap

changes). However, the specific langua

does not apply until SIPs are changed. 

93.106 Content of transportation 

plans. 

August 1997 rule, except July 2004 revision: 

(b) expanded; now includes additional situations under 

which a 2-year grace period for transportation plan content would apply, for certain CO and ozone areas. 

No for revisions to (b): 

i.e., (b)(2) and (b)(3) do not apply. The 

related to the new standards or court de

93.107 Relationship of transportation plan and TIP conformity with the NEPA process. 

August 1997 rule– not changed in July 2004 rule. (N/A) 

93.108 Fiscal constraints for transportation plans and TIPs. 

August 1997 rule– not changed in July 2004 rule. (N/A) 

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EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.109 Criteria and procedures for 

determining conformity of 

transportation plans, programs, and 

projects: General. 

August 1997 rule: 

(a) introduction 

July 2004 rule revisions: 

(b) table 1, conformity criteria 

(c) 1-hour ozone areas 

(f) CO areas (g) PM10 areas 

(h) NO2 areas 

(l) isolated rural areas 

In these paragraphs, the phrase “emissions reduction tests” is 

replaced by “interim emissions tests.” In addition, in (c)(1), 

(f)(2), (g)(2), and (h)(2), the July 2004 provisions clarify 

when budgets in SIPs must be used for conformity: (i) Upon the effective date of EPA’s adequacy finding; 

(ii) Upon the publication date of EPA’s approval of a SIP; 

and (iii) Upon the effective date of EPA’s approval of a SIP 

made via a direct final rule. 

July 2004 rule additions: 

(d) 8-hour ozone areas without budgets 

(e) 8-hour ozone areas with 1-hour budgets (i) PM2.5 areas 

(j) limited maintenance plans (k) insignificance 

July 2004 rule revisions: 

With regard to the change in the name o

tests” to “interim emissions tests”) in pa

(l), states with approved conformity SIP

consistent with the July 2004 rule. Yes for provisions in (c)(1)(i), (f)(2)(i), 

these provisions are a result of the cour

budget test must be used upon the effec

finding. For the remaining changes in paragraph

addition of (c)(1)(ii) and (iii), (f)(2)(ii) 

their existing rules consistent with the Jregulatory text provisions are new, they 

existing policy, which continues to appFor July 2004 rule additions: Yes for paragraphs (d), (e), and (i), as tFor paragraphs (j) and (k), states can in

consistent with the July 2004 rule so th

applies. These two paragraphs address 

insignificance respectively. Though the

new, they reflect what has been conform

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EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.110 Criteria and procedures: 

Latest planning assumptions. 

August 1997 rule, except for: 

July 2004 rule revision: (a) changed the point at which latest planning assumptions 

are determined for a conformity determination. 

July 2004 rule revision: 

No, this change to (a) does not apply in 

SIPs, because this change is not related decision. Areas in states with an appro

to use the latest planning assumptions a

determination is made, until the SIP is r

93.111 Criteria and procedures: 

Latest emissions model. 

August 1997 rule – not changed in July 2004 rule (N/A) 

93.112 Criteria and procedures: 

Consultation. 

August 1997 rule – not changed in July 2004 rule (N/A) 

93.113 Criteria and procedures: 

Timely implementation of TCMs. 

August 1997 rule – not changed in July 2004 rule (N/A) 

93.114 Criteria and procedures: 

Currently conforming transportation plan and TIP. 

August 1997 rule – not changed in July 2004 rule (N/A) 

93.115 Criteria and procedures: 

Projects from a plan and TIP 

August 1997 rule – not changed in July 2004 rule (N/A) 

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EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.116 Criteria and procedures: 

Localized CO and PM10 violations 

(hot spots). 

July 2004 rule clarified the time period to be addressed in 

hot-spot analyses. 

States can interpret their existing rules c

so that the substance of the new rule ap

language of the July 2004 rule clearly d

changed. EPA believes the July 2004 rule change 

hot-spot requirements established in the 

preamble states “EPA does not anticipa

significantly change how project-level a

practice,” (69 FR 40056). In other worconformity SIPs, EPA expects that the y

analysis would be the year where emissgreatest. In choosing such a year, the h

requirement to consider the 20 year per

93.117 Criteria and procedures: 

Compliance with PM10 and PM2.5 

control measures. 

July 2004 rule added PM2.5 to this provision, so that 

compliance with SIP control measures is required in PM2.5 areas. 

Yes, because this change is related to th

17 
EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.118 Criteria and procedures: 

Motor vehicle emissions budget. 

August 1997 rule except the following: July 2004 rule additions: 

(b)(2)(iv): analysis years before last year of maintenance plan must be < budgets from most recent prior year. 

(f): adequacy procedures 

July 2004 rule revisions: 

(a): reference updated (b): intro text revised to include attainment year as a year 

for which consistency must be demonstrated; 

(b)(2)(iii) revised; (e): (e)(1), (e)(2), (e3) 

July 2004 rule additions: 

For paragraph (b)(2)(iv), states can inte

with the July 2004 rule so that the substapplies. However, the specific languag

not apply until SIPs are changed. Thou

new, it reflects what has been EPA’s exapply. The provision also mirrors the 1

covers the period of time before mainteYes for paragraph (f), because this addirule is a result of the court decision. 

July 2004 rule revisions: 

For provisions in (a), (b) introductory te

interpret their existing rules consistent w

substance of the July 2004 provision apfor paragraph (b) introductory text clari

year for which consistency with budgetEPA assumes most areas were doing so 

the requirement to analyze the attainme

2004 rule language for (b)(2)(iii) clarifi

rule, but even before this clarification E

require conformity to budgets in submit

Yes for paragraph (e) – (e)(1), (e)(2), an

are a result of the court decision. 

18 
EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.119 Criteria and procedures: 

Interim emissions in areas without 

motor vehicle emissions budgets. 

August 1997 rule, except the following: 

July 2004 rule revisions: 

Title of section 

(a) intro (b) ozone areas 

(c) CO areas (d) PM10 and NO2 areas 

(f) pollutants (g) analysis years 

July 2004 rule additions: 

(b)(1)(ii)(B) and (b)(2)(ii)(B), 2002 test for 8-hour ozone 

areas (e) PM2.5 areas 

(f)(7) and (8), PM2.5 pollutants (g)(2): allows areas to skip an analysis year in the 

build/no-build test if action and baseline scenarios are the 

same 

July 2004 rule revisions: 

No for the following paragraphs: 

(a), (b) except for (b)(1)(ii)(B) and (b)(2(c), (d), (f) except for (f)(7) and (f)(8), and 

(g) 

because these revisions were made to in

ozone, CO, NO2, and PM10 nonattainme

revisions do not address the new standa

July 2004 rule additions: 

Yes for the following paragraphs: 

(b)(1)(ii)(B) and (b)(2)(ii)(B) 

(e), and (f)(7) and (8), 

because these provisions address the nestandards. For (g)(2), states with approved SIP couthe build and no-build scenarios are the 

analysis per se, but should consult EPA 2004 rule, this provision did not specify 

93.120 Consequences of control 

strategy implementation plan 

failures. 

August 1997 rule except for the following: 

July 2004 revision: 

(a)(2) specifying when conformity freezes start for SIP 

disapprovals without a protective finding. 

Yes, (a)(2) applies because this change 

decision. 

19 
EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.121 Requirements for adoption 

of projects by other recipients of 

funds designated under title 23 

U.S.C. or the Federal Transit Laws. 

August 1997 rule except for the following: 

July 2004 revisions: 

(a) revised (b) references updated, minor change to (b)(1) (c) added for limited maintenance plans and areas where motor vehicles are insignificant 

Yes for paragraph (a), because these ch

decision For paragraph (b), states can interpret th

the July 2004 rule, so that the substance the specific language of the July 2004 r

SIPs are changed. No for paragraph (c), because (c) create

in states’ approved conformity SIPs. 

93.122 Procedures for determining 

regional transportation-related 

emissions 

August 1997 rule except for the following: 

July 2004 revisions/additions: 

(c) expands two year grace period before modeling 

requirements apply (f) PM2.5 construction dust 

(g)(3) clarifies conformity determination that relies on a previous regional emissions analysis does not satisfy 

frequency requirements 

No for paragraph (c), which creates an 

states’ approved conformity SIPs. Howto be limited if any. Yes for paragraph (f), which applies to 

For paragraph (g)(3), states can interpre

with the July 2004 rule so that the substthough this provision is not included in 

clarifies an existing requirement and de

has always been interpreted. 

93.123 Procedures for determining 

localized CO and PM10 

concentrations (hot-spot analysis) 

August 1997 rule – not changed in July 2004 rule (N/A) 

20 
EPA Conformity SIP Guidance November 18, 2004 

Provision of current federal 

conformity rule 

What rule finalized this provision? Does the change to this provi

areas with an approved confor

rule, if the SIP includ

--Why or w

93.124 Using the motor vehicle 

emissions budget in the applicable 

implementation plan (or 

implementation plan submission) 

August 1997 rule, except for the following: 

July 2004 rule deletion: 

(b) deleted (re: safety margins in SIPs submitted before 

1993), remaining paragraphs relettered. 

Yes, because this change resulted from 

93.125 Enforceablity of design 

concept and scope and project-level 

mitigation and control measures 

August 1997 rule except for the following: 

July 2004 rule revision: 

Reference changes States can interpret their existing rules c

so that the substance of the new rule ap

updates). However, the specific langua

apply until SIPs are changed. 

93.126 Exempt projects August 1997 rule except for the following: 

July 2004 rule revision: 

Reference change to be consistent with DOT’s regulations States can interpret their existing rules c

so that the substance of the new rule ap

updates). However, the specific langua

apply until SIPs are changed. 

93.127 Projects exempt from regional emissions analyses 

August 1997 rule – not changed in July 2004 rule (N/A) 

93.128 Traffic signal sychronization projects 

August 1997 rule – not changed in July 2004 rule (N/A) 

21