Ref: 8P-AR 

Date: October 18,2013 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http :1/www. epa. gov /reg ion08 

SUBJECT: Memorandum to Docket No. EPA-R08-0AR- 2011-0562: EPA's evaluation of 

Colorado's Regulation No. 10 "Criteria for Analysis of Conformity" as submitted to EPA as 

a State Implementation Plan (SIP) revision on May 11, 2012. 

In reviewing the State's May 11,2012 SIP revisions to Colorado's Regulation No. 10, EPA consulted our 

"Transportation Conformity State Implementation Plans" guidance located at: 

http://www .epa. gov I otaq/ stateresources/transconf/po licy .htm 

State Implementation Plans (SIPs) and Conformity 

• Guidance for Developing Transportation Conformity State Implementation Plans (PDF) (31 pp, 277K, 

EPA420-B-09-001, January 2009) 

This document provides guidance on the statutory and regulatory requirements for states to develop 

conformity state implementation plans. This document supersedes the November 2004 Conformity SIP 

Guidance and Section 7 of the Interim Guidance for Implementing the Transportation Conformity 

Provisions in the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users 

(SAFETEA-LU) (February 2006). 

Checklist for Developing a Conformity SIP (PDF)- Appendix A (6 pp, 11 SK) 

A.) Our review also included a comparison of the State's Regulation No. 10 contents to our above 

referenced "Checklist for Developing a Conformity SIP". Our analysis is as provided below: 

1.) INTERAGENCY CONSULTATION 

a.) GENERAL: [93.105(a)]. A conformity SIP shall include procedures for interagency 

consultation, conflict resolution, and public consultation. EPA encourages development of 

extensive, effective consultation procedures that will resolve problems as early in the process as 

possible. See 58 FR 62188 at 62201, November 24, 1993. The procedures must be written in a 

manner that gives them full legal effect. See 40 CFR 51.390. 

Consultation is required on the development of the regional transportation plan (RTP), the transportation 

improvement program (TIP), on conformity determinations, and on the development of state 

implementation plan (SIP) revisions that affect transportation. [93.105(a)(1)]. 
MPOs and State departments of transportation must provide reasonable opportunity for consultation with 

State air agencies, local air quality and transportation agencies, DOT, and EPA, including consultation on 

specific processes for interagency consultation. [93.105(a)(2)] 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in section III 

"Interagency Consultation". 

b.) INTERAGENCY CONSULTATION PROCEDURES: GENERAL FACTORS [93.105(b)]. 

States shall provide well defined consultation procedures in the implementation plan. Organizations with 

responsibilities for developing, submitting or implementing provisions of an implementation plan 

(including MPOs, State and local air quality planning agencies, and State and local transportation 

agencies) must consult with each other with and local or regional offices of EPA, the Federal Highway 

Administration (FHWA), and the Federal Transit Administration (FTA). 

The interagency consultation procedures must include, at a minimum, the following general factors: 

• Procedures that require that agencies consult on the development of the implementation plan, the 

transportation plan, the TIP, and associated conformity determinations [93.105(b)(1)]; 

• The roles and responsibilities of each agency at each stage in the SIP development process and the 

transportation planning process, including technical meetings [93.105(b)(2)(i)]; 

• The organizational level of regular consultation [93.105(b)(2)(ii)]; 

• A process for circulating (or providing ready access to) draft documents and supporting materials 

for comment before formal adoption or publication [93.105(b)(2)(iii)]; 

• The frequency of, or process for convening, consultation meetings and responsibility for 

establishing meeting agendas [93 .1 05(b )(2)(i v)]; 

• A process for responding to significant comme!lts of involved agencies [93.105(b)(2)(v)]; and 

• A process for the development of a list of the transportation control measures (TCMs) that are in 

the applicable implementation plan [93 .1 05(b )(2)( vi)]. 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in sections: II 

"Definitions", III.A "Roles and Responsibilities for Transportation Conformity Determinations and 

Related SIP Development", and III.B. "Establishing a Forum for Regional Conformity 

Consultation". 

c.) SPECIFIC PROCESSES Interagency consultation procedures shall include the specific processes 

listed below [93 .1 05( c)]: 

A process involving at least the MPO(s), State and local air quality planning and transportation agencies, 

EPA, and the Department ofTransportation (DOT) for the following [93.105(c)(1)]: 

• Evaluating and choosing models and associated methods and assumptions for hot-spot and 

regional emissions analyses [93.105(c)(1)(i)]; 

• Determining which minor arterials and other projects are "regionally significant"for the regional 

emissions analysis (in addition to those functionally classified as principal arterials or higher or 

fixed guide way systems or extensions that offer an alternative to regional highway travel) 

[93.1 05( c )(1 )(ii)]; 

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• Determining which projects should be considered to have a significant change in design concept 

and scope from the RTP or TIP [93.105(c)(1)(ii)]; 

• Evaluating whether otherwise exempt projects (see 93.126 and 93.127) should be treated as nonexempt where adverse impacts are possible for any reason [93.105(c)(l)(iii)]; 

• Determining whether past obstacles to implementation of transportation control measures (TCMs) 

in approved SIPs have been identified and are being overcome (for TCMs behind SIP schedules) 

[93.105(c)(l)(iv); 93.113(c)(1)]; 

• Determining whether State and local agencies are giving maximum priority to approval and 

funding for TCMs in approved SIPs [93.105(c)(l)(iv)]; 

• Determining whether delays in the implementation of approved SIP TCMs necessitate revisions to 

the SIP to remove or substitute such TCMs or other emission reduction measures 

[93.1 05( c )(1 )(iv)]; 

• Notification oftransportation plan and TIP amendments which only add or delete exempt projects 

listed in 93.126 and 93.127 [93.105(c)(l)(v)]; and 

• Choosing conformity tests and methodologies for isolated rural nonattainment and maintenance 

areas, as required by 93.109(1)(2)(iii) [93.105(c)(1)(vi)]. 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in sections: III.A 

"Roles and Responsibilities for Transportation Conformity Determinations and Related SIP 

Development", III.B "Establishing a Forum for Regional Conformity Consultation", and III.C 

"Topics for Consultation". 

d.) A process involving at least the MPO and State and local air and transportation agencies for 

[93.105( c)(2)]: 

• Evaluating events that will trigger new conformity determinations in addition to those required by 

93.104 [93.1 05( c )(2)(i)]; and 

• Consulting on emissions analysis for transportation activities which cross borders of MPOs, 

nonattainment areas or air basins [93.1 05( c )(2)(ii)]. 

• Where the metropolitan planning area does not include the entire nonattainment or maintenance 

area, procedures must specify a process involving the MPO and the State DOT for cooperative 

planning and analysis for determining conformity of projects outside the metropolitan area and 

within the nonattainment or maintenance area [93.1 05(c)(3)]. 

• Specifies a process to ensure disclosure of plans for regionally significant non-FHW NFTA 

projects (including projects for which alternatives are still being considered) to the MPO on a 

regular basis, and immediate disclosure of any changes to those plans [93.105(c)(4)]. 

• Provides a process involving the MPO and other federal funds recipients for assuming project 

location and design concept/scope where these features not adequately defined for regional 

emissions analysis [93.105(c)(5)]. 

• Specifies a process for consulting on design, schedule, and funding of research and data collection 

efforts and regional transportation model development by the MPO [93.105(c)(6)]. 

• Specifies a process for providing final documents and supporting information to each agency 

(including federal agencies) after approval or adoption [93.105(c)(7)]. 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in sections: III.B 

"Establishing a Forum for Regional Conformity Consultation", III.C "Topics for Consultation", 

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III.D "Process for assuming the location and design concept and scope of projects disclosed to the 

MPO as required by paragraph (E) of this section, but whose sponsors have not yet decided these 

features in sufficient detail to perform the regional emissions analysis according to the 

requirements of 40 CFR 93.122", III.E "Process to ensure that plans for construction of regionally 

significant projects which are not FHW AIFTA projects (including projects for which alternative 

locations, design concept and scope, or the no-build options are still being considered), including 

those by recipients of funds designated under Title 23 U.S.C. or the Federal Transit Act, are 

disclosed on a regular basis, and to ensure that any changes to those plans are immediately 

disclosed", III.F "Consultation procedures for development of State Implementation Plans", and III.G 

"Agreements further describing consultation procedures". 

Currently, the situations described in 40 CFR 93.105(c)(2)(ii) and 93.105(c)(3) only exist within the 

Metro-Denver/North Front Range 8-hour ozone nonattainment area. Specific procedures that meet 

the requirements of 40 CFR 93.105( c)(2)(ii) and 93.105( c)(3) are provided in the EPA-approved 

Ozone Action Plan as described in detail in section (C) below. 

e.) RESOLVING CONFLICTS [93.105(d)]. 

The process for resolving conflicts must sp~cify that: 

• Unresolveable conflicts among state agencies or between state agencies and an MPO shall be 

escalated to the Governor or Governors designee (the designee cannot be the State or local air 

agency, State department of transportation, State transportation commission or board, or an MPO) 

[93.105(d)]; 

• The State air agency has 14 calendar days (the implementation plan should define the procedures 

for starting the 14-day clock) to appeal to the Governor after the State DOT or MPO has notified 

the State air agency head ofthe resolution ofhis or her comments [93.105(d)]; and 

• If the State air agency appeals to the Governor, the final conformity determination must have 

Governors concurrence. If there is no appeal, the MPO or state DOT may proceed with the final 

conformity determination [93.105(d)]. 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in section III.H 

"Review of Conformity Determinations by the public, the Air Quality Control Commission, and 

resolution of conflicts". 

f.) PUBLIC CONSULTATION PROCEDURES. Affected agencies making conformity determinations 

on transportation plans, TIPs, and projects shall establish a proactive public involvement process 

[93.105(e)]. This general requirement can be satisfied by referencing the MPO's procedures, in addition 

to specifying or referencing the additional items listed below. 

Consultation procedures must set out a public process that, at a minimum: 

• Provides for reasonable public access to technical and policy information considered by the 

agency at the beginning of the public comment period and prior to taking formal action on a 

transportation plan or TIP conformity determination, consistent with 93.105 and 23 CFR 

450.316(a) [93.105(e)]; 

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• Ensures that any charges imposed for public inspection or copying are reasonable [49 CFR 7.43, 

93.105(e)]; 

• Provides that agencies must specifically address in writing all public comments that plans for 

regionally significant non-FHW A/FTA projects are not properly reflected in the emissions 

analysis [93.105(e)]; and 

• Provides opportunity for public involvement in project conformity determinations as otherwise 

required by law [93.105(e)]. 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in section III.H 

"Review of Conformity Determinations by the public, the Air Quality Control Commission, and 

resolution of conflicts". 

2.) OTHER CONFORMITY PROCEDURES: Under Clean Air Act, as amended by SAFETEA-LU, 

conformity SIPs must also include conformity procedures that address 40 CFR 93.122(a)(4)(ii) and 

93 .125( c). All ·other federal conformity regulations apply automatically and states are not required to 

address them in conformity SIPs. 

EPA Response: Noted. 

3.) ENFORCEABLE WRITTEN COMMITMENTS REQUIRED FOR EMISSIONS 

REDUCTION CREDIT: Emissions reduction credit from any control measures that are not included in 

the transportation plan and TIP and that do not require a regulatory action in order to be implemented may 

not be included in the emissions analysis unless the conformity determination includes written 

commitments to implementation from the appropriate entities [93.122(a)( 4)(ii)]. 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in section IV 

"Emission reduction credit for certain control measures". 

4.) ENFORCEABILITY OF DESIGN CONCEPT AND SCOPE AND PROJECT -LEVEL 

MITIGATION AND CONTROL MEASURES: Before a conformity determination is made, written 

commitments must be obtained for any project-level mitigation or control measures. [93.125( c)] 

EPA Response: Aspects of these provisions are provided in Regulation No. 10 in section V 

"Enforceability of design concept and scope and project-level mitigation and control measures". 

B.) EPA noted minor, non-substantive typographical errors and an incorrect reference in 

Regulation No. 10: 

1.) Non-substantive typographical errors: 

a.) Page 3 of Regulation No. 10, section III.A.2 contains a reference to section IV.H. The correct 

reference is to section III.H. 

b.) Page 3 of Regulation No. 10, section III.A.3 contains a reference to section IV.G. The correct 

reference is to section III.G. 

c.) Page 5 of Regulation No. 10, section III.B.l.a contains a reference to section IV.B.l.b. The correct 

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reference is to section III.B.1.b. 

d.) Page 6 of Regulation No. 10, section III.C.l.b(2) contains a reference to section IV.E. The correct 

reference is to section III.E. 

e.) Page 11 of Regulation No. 10, section III.F.3 contains a reference to section IV.F. The correct 

reference is to section III.F. 

2.) Incorrect reference: Page 8 ofRegulation No. 10, section III.C.l.g refers to 40 CFR 93.109(1). EPA 

revised 40 CFR 93, Subpart A on March 14, 2012 (see 77 FR 14979). The final rule was entitled 

"Transportation Conformity Rule Restructuring Amendments" and this rule revised EPA's transportation 

conformity rule which, among other changes, resulted in 40 CFR 93.109(1) becoming 40 CFR 93 .109(g). 

C.) Existing procedures for the Metro-Denver/North Front Range 8-hour ozone nonattainment 

area: 

The requirements of40 CFR40 CFR 93.105(c)(2)(ii) are addressed by section III.C.2.b ofRegulation No. 

10, which reads as follows: 

"III.C.2.b. Consulting on emissions analysis for transportation activities that cross the borders of 

MPOs or nonattainment areas or basins. 

In the event that contiguous MPOs are created within the state, the affected MPOs shall, in 

consultation with the participants in the consultation process, establish a consultation procedure 

for consulting on emissions analyses for transportation activities that cross the borders of MPOs or 

nonattainment areas or air basins." 

For the Metro-Denver/North Front Range 8-hour ozone nonattainment area, the specific consultation 

procedure is provided in: "CHAPTER VI: VOC AND NOx MOTOR VEHICLE EMISSIONS 

BUDGETS" of the "Denver Metro Area & North Front Range Ozone Action Plan; Including 

Revisions to the State Implementation Plan (Approved by: Colorado Air Quality Control 

Commission December 12, 2008)" as approved by EPA on August 5, 2011 (76 FR 47443). 

The Ozone Action Plan full text is available at: 

http://www.colorado.gov/cs/Satellite?blobcol=urldata&blobheademame 1 =ContentDisposition& blo bheademame2=ContentType&blobheadervalue 1 =inline%3 B+filename%3D%220zone+ Action+ Plan+ 2008. pdf0/o22&blobheader 

value2=application%2Fpdf&blobkey=id&blobtable=MungoBlobs&blobwhere=1251808867302&ssbinar 

y=true 

In addition, the reader should also refer to the March 14, 2008 Memorandum of Agreement (MOA) that 

accompanied the Ozone Action Plan which is entitled: 

"MEMORANDUM OF AGREEMENT FOR TRANSPORTATION CONFORMITY EVALUATIONS 

CONDUCTED UNDER THE 8-HOUR OZONE STANDARD BY AND BETWEEN THE COLORADO 

DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, THE DENVER REGIONAL AIR 

QUALITY COUNCIL, THE COLORADO DEPARTMENT OF TRANSPORTATION, THE UPPER 

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FRONT RANGE TRANSPORTATION PLANNING REGION, THE NORTH FRONT RANGE 

TRANSPORTATION AND AIR QUALITY PLANNING COUNCIL (a.k.a. the North Front Range 

MPO), AND THE DENVER REGIONAL COUNCIL OF GOVERNMENTS" (This document is 

available from the Denver Regional Council of Governments - DRCOG- at http://www.DRCOG.org) 

The Metro-Denver/North Front Range 8-hour ozone nonattainment area specific consultation procedure is 

excerpted, in part, from the Ozone Action Plan and is provided below: 

CHAPTER VI 

VOC AND NOx MOTOR VEHICLE EMISSIONS BUDGETS 

A. Transportation Conformity 

Transportation conformity provisions of section 176 (c)(2)(A) of the Clean Air Act (CAA) 

require regional transportation plans and transportation improvement programs to demonstrate that 

" ... emissions expected from implementation of plans and programs are consistent with estimates of 

emissions from motor vehicles and necessary emissions reductions contained in the applicable 

implementation plan .. . " 

The Environmental Protection Agency's (EPA) transportation conformity rule requires that control 

strategy implementation plans, which are defined in 40 CFR 93.1 01 as reasonable further progress plans 

and attainment demonstrations, contain motor vehicle emissions budgets. Because this State 

Implementation Plan (SIP) is an 8-hour ozone attainment demonstration, motor vehicle emissions budgets 

for volatile organic compounds (VOC) and nitrogen oxides (NOx) are proposed for 2010, which is the 

area's attainment year. Once these budgets are found adequate or are approved, the metropolitan planning 

organizations (MPOs) in the nonattainment area will use the budgets to demonstrate that projected 

emissions that would result from implementation of their transportation plans and transportation 

improvement programs are less than or equal to the adequate or approved emissions budgets. 

The 8-hour ozone nonattainment area encompasses multiple MPOs and transportation planning regions. 

The Denver Regional Council of Governments (DRCOG) is the metropolitan planning organization 

responsible for transportation planning in the 7 -county Denver metropolitan area and a portion of 

southwest Weld County. Likewise, the North Front Range Transportation and Air Quality Planning 

Council (NFRTAQPC) is the metropolitan planning organization responsible for transportation planning 

in the urbanized portions of Larimer and Weld counties. Finally, the Upper Front Range (UFR) 

Transportation Planning Region (TPR), not a designated metropolitan planning organization, is 

responsible for transportation planning in the rural portions of Larimer, Weld, and Morgan counties. 

Because of the different institutional arrangements and different schedules and timelines for transportation 

plans and programs development, this SIP establishes both VOC and NOx subarea motor vehicle 

emission budgets, and budgets for VOCs and NOx for the entire nonattainment area for purposes of 

transportation conformity in the Denver/North Front Range 8-hour ozone nonattainment area. The two 

subareas are described below. Also described below are the procedures to be followed when switching 

between using subarea budgets and the nonattainment area-wide budgets. 

B. Motor Vehicle Emissions Budgets 

According to EPA regulations and guidance, the SIP may establish a budget or budgets 

that apply to the entire nonattainment area, and/or subarea budgets for each metropolitan planning 

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organization or subarea within the nonattainment area. For purposes of this SIP, Motor Vehicle 

Emissions Budgets for VOC and NOx are established for the 2010 attainment year. Budgets are 

specifically established for two sub-regional areas and for the entire nonattainment area for purposes of 

transportation conformity. The two subareas are defined as follows and shown in Figure 2: 

• Southern Subarea--Area denoted by the ozone nonattainment area south ofthe Boulder County 

northern boundary and extended through southern Weld County to the Morgan County line. This area 

includes the nonattainment portion ofDRCOG's' regional planning area and the southern Weld County 

portion of the Upper Front Range TPR. 

• Northern Subarea--Area denoted by the ozone nonattainment area north of the Boulder County 

northern boundary and extended through southern Weld County to the Morgan County line. This area 

includes the North Front Range Transportation and Air Quality Planning Council transportation planning 

area as well as the northern ozone nonattainment area portion the Upper Front Range TPR in Larimer and 

Weld counties. 

Figure 2: 8-Hour Ozone Emission Budget Subarea 

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