[Federal Register Volume 72, Number 159 (Friday, August 17, 2007)]
[Rules and Regulations]
[Pages 46148-46157]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-16146]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2007-0465; FRL-8453-5]


Approval and Promulgation of Air Quality Implementation Plans; 
State of Colorado; Revised Denver and Longmont Carbon Monoxide 
Maintenance Plans, and Approval of Related Revisions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: EPA is taking direct final action approving a State 
Implementation Plan (SIP) revision submitted by the State of Colorado. 
On September 25, 2006, the Governor's designee submitted revised carbon 
monoxide (CO) maintenance plans for the Denver metropolitan and 
Longmont areas for the CO National Ambient Air Quality Standard 
(NAAQS). These revised maintenance plans address maintenance of the CO 
standard for a second ten-year period beyond redesignation, extends the 
horizon years, and contains revised transportation conformity budgets. 
In addition, Regulation No. 11, ``Motor Vehicle Emissions Inspection 
Program,'' and Regulation No. 13, ``Oxygenated Fuels Program,'' are 
removed from Denver's and Longmont's revised CO maintenance plans. EPA 
is approving Denver's and Longmont's revised CO maintenance plans, and 
the revised transportation conformity budgets. In addition, EPA is also 
approving the removal of Regulation No. 11 and Regulation No. 13 from 
Denver's and Longmont's revised CO maintenance plans. This action is 
being taken under section 110 of the Clean Air Act.

DATES: This direct final rule is effective on October 16, 2007 without 
further notice, unless EPA receives adverse comment by September 17, 
2007. If adverse comment is received, EPA will publish a timely 
withdrawal of the direct final rule in the Federal Register informing 
the public that the rule will not take effect.

ADDRESSES: Submit your comments, identified by Docket Number EPA-R08-
OAR-2007-0465, by one of the following methods:
     http://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     E-mail: [email protected] and [email protected].
     Fax: (303) 312-6064 (please alert the individual listed in 
the FOR FURTHER INFORMATION CONTACT if you are faxing comments).
     Mail: Callie A. Videtich, Director, Air and Radiation 
Program, Environmental Protection Agency (EPA), Region 8, Mailcode 8P-
AR, 1595 Wynkoop Street, Denver, Colorado 80202-1129.
     Hand Delivery: Callie A. Videtich, Director, Air and 
Radiation Program, Environmental Protection Agency (EPA), Region 8, 
Mailcode 8P-AR, 1595 Wynkoop Street, Denver, Colorado 80202-1129. Such 
deliveries are only accepted Monday through Friday, 8 a.m. to 4:30 
p.m., excluding Federal holidays. Special arrangements should be made 
for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-R08-OAR-
2007-0465. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available at http:/
/

[[Page 46149]]

www.regulations.gov, including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through http://www.regulations.gov or e-
mail. The http://www.regulations.gov Web site is an ``anonymous 
access'' system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA, without going through http://www.regulations.gov your e-mail address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses. For additional information about EPA's public docket visit the 
EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm. 
For additional instructions on submitting comments, go to Section I. 
General Information of the SUPPLEMENTARY INFORMATION section of this 
document.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g. CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the Air and Radiation 
Program, Environmental Protection Agency (EPA), Region 8, 1595 Wynkoop 
Street, Denver, Colorado 80202-1129. EPA requests that if at all 
possible, you contact the individual listed in the FOR FURTHER 
INFORMATION CONTACT section to view the hard copy of the docket. You 
may view the hard copy of the docket Monday through Friday, 8 a.m. to 4 
p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Kerri Fiedler, Air and Radiation 
Program, Environmental Protection Agency (EPA), Region 8, Mailcode 8P-
AR, 1595 Wynkoop Street, Denver, Colorado 80202-1129, phone (303) 312-
6493, and e-mail at: [email protected]..

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
II. What is the purpose of this action?
III. What is the State's process to submit these materials to EPA?
IV. EPA's Evaluation of Denver's and Longmont's Revised CO 
Maintenance Plans
V. EPA's Evaluation of the Transportation Conformity Requirements
VI. EPA's Evaluation of Regulation No. 11 Revisions
VII. EPA's Evaluation of Regulation No. 13 Revisions
VIII. Consideration of Section 110(l) of the Clean Air Act
IX. Final Action
X. Statutory and Executive Order Reviews

Definitions

    For the purpose of this document, we are giving meaning to 
certain words or initials as follows:
    (i) The words or initials Act or CAA mean or refer to the Clean 
Air Act, unless the context indicates otherwise.
    (ii) The words EPA, we, us or our mean or refer to the United 
States Environmental Protection Agency.
    (iii) The initials NAAQS mean National Ambient Air Quality 
Standard.
    (iv) The initials SIP mean or refer to State Implementation 
Plan.
    (v) The word State means the State of Colorado, unless the 
context indicates otherwise.

I. General Information

A. What Should I Consider as I Prepare My Comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
http://www.regulations.gov or e-mail. Clearly mark the part or all of 
the information that you claim to be CBI. For CBI information in a disk 
or CD ROM that you mail to EPA, mark the outside of the disk or CD ROM 
as CBI and then identify electronically within the disk or CD ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
    a. Identify the rulemaking by docket number and other identifying 
information (subject heading, Federal Register date and page number).
    b. Follow directions--The agency may ask you to respond to specific 
questions or organize comments by referencing a Code of Federal 
Regulations (CFR) part or section number.
    c. Explain why you agree or disagree; suggest alternatives and 
substitute language for your requested changes.
    d. Describe any assumptions and provide any technical information 
and/or data that you used.
    e. If you estimate potential costs or burdens, explain how you 
arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
    f. Provide specific examples to illustrate your concerns, and 
suggest alternatives.
    g. Explain your views as clearly as possible, avoiding the use of 
profanity or personal threats.
    h. Make sure to submit your comments by the comment period deadline 
identified.

II. What is the purpose of this action?

    In this action, we are approving revised maintenance plans for the 
Denver and Longmont CO attainment/maintenance areas, that are designed 
to keep the areas in attainment for CO for a second ten-year period 
beyond redesignation. In addition, we are approving revised 
transportation conformity motor vehicle emissions budgets (MVEBs), and 
the removal of Regulation No. 11, ``Motor Vehicle Emissions Inspection 
Program,'' and Regulation No. 13, ``Oxygenated Fuels Program,'' from 
Denver's and Longmont's revised CO maintenance plans.
    We approved the original CO redesignation to attainment and 
maintenance plan for the Denver area on December 14, 2001 (see 66 FR 
64751), and a revised CO maintenance plan for the Denver area on 
September 16, 2004 (see 69 FR 55752). The State has made the following 
changes: (1) Revised and updated the mobile source CO emissions with 
MOBILE6.2, based on the pending removal of Regulation No. 11, the 
inspection and maintenance (I/M) program, and Regulation No. 13, the 
oxygenated fuels program; (2) updated the transportation projections 
and stationary source inventories; (3) revised the MVEBs including 
applying a selected amount of the available safety margin to the 
transportation conformity MVEBs; and, (4) extended the horizon

[[Page 46150]]

year to 2021. We have determined that these changes are approvable as 
further described below.
    We approved the original CO redesignation to attainment and 
maintenance plan for the Longmont area on September 24, 1999 (see 64 FR 
51694), and a revised CO maintenance plan for the Longmont area on 
September 30, 2004 (see 69 FR 58264). The State has made the following 
changes: (1) Revised and updated the mobile source CO emissions with 
MOBILE6.2, based on the pending removal of the I/M and oxygenated fuels 
programs; (2) updated the transportation projections and stationary 
source inventories; (3) revised the MVEBs including applying a selected 
amount of the available safety margin to the transportation conformity 
MVEBs; and, (4) extended the horizon year to 2020. We have determined 
that these changes are approvable as further described below.

III. What is the State's process to submit these materials to EPA?

    Section 110(k) of the CAA addresses our actions on submissions of 
revisions to a State Implementation Plan (SIP). The CAA requires States 
to observe certain procedural requirements in developing SIP revisions 
for submittal to us. Section 110(a)(2) of the CAA requires that each 
SIP revision be adopted after reasonable notice and public hearing. 
This must occur prior to the revision being submitted by a State to us.
    The Colorado Air Quality Control Commission (AQCC) held a public 
hearing for the revised Denver and Longmont carbon monoxide (CO) 
maintenance plans, Regulation No. 11 and Regulation No. 13 on December 
15, 2005. The AQCC adopted the revised CO maintenance plans and removal 
of Regulation No. 11 and Regulation No. 13 from Denver's and Longmont's 
revised CO maintenance plans directly after the hearing. This SIP 
revision became State effective on March 2, 2006, and was submitted by 
the Governor's designee to us on September 25, 2006.
    We have evaluated the revised maintenance plans and have determined 
that the State met the requirements for reasonable notice and public 
hearing under section 110(a)(2) of the CAA. As required by section 
110(k)(1)(B) of the CAA, we reviewed these SIP materials for 
conformance with the completeness criteria in 40 CFR part 51, Appendix 
V and determined that the submittal was administratively and 
technically complete. Our completeness determination was sent on 
February 21, 2007, through a letter from Robert E. Roberts, Regional 
Administrator, to Governor Bill Ritter.

IV. EPA's evaluation of Denver's and Longmont's Revised CO Maintenance 
Plans

    EPA has reviewed the State's revised CO maintenance plans for the 
Denver and Longmont attainment/maintenance areas and believes that 
approval is warranted. The following are the key aspects of these 
revisions along with our evaluation of each:
    (a) The State has revised the Denver and Longmont CO maintenance 
plans and has provided air quality data that show continuous attainment 
of the CO NAAQS.
    As described in 40 CFR 50.8, the national primary ambient air 
quality standard for carbon monoxide is 9 parts per million (10 
milligrams per cubic meter) for an 8-hour average concentration not to 
be exceeded more than once per year. 40 CFR 50.8 continues by stating 
that the levels of CO in the ambient air shall be measured by a 
reference method based on 40 CFR part 50, Appendix C and designated in 
accordance with 40 CFR part 53 or an equivalent method designated in 
accordance with 40 CFR part 53. The original Denver CO maintenance 
plan, approved by EPA on December 14, 2001, relied on ambient air 
quality data from 1996 through 1999. The previously revised Denver CO 
maintenance plan, approved by EPA on September 16, 2004, relied on 
ambient air quality data from 2000 through 2002. This revised Denver CO 
maintenance plan submitted September 25, 2006, relies on ambient air 
quality data from 2002 through 2004. Further, we have reviewed ambient 
air quality data from 2005 and 2006 and the Denver area shows 
continuous attainment of the CO NAAQS from 2000 to present.
    The original Longmont CO maintenance plan, approved by EPA on 
September 24, 1999, relied on ambient air quality data from 1989 
through 1996. The previously revised Longmont CO maintenance plan, 
approved by EPA on September 30, 2004, relied on ambient air quality 
data from 1993 through 2003. This revised Longmont CO maintenance plan 
submitted September 25, 2006, relies on ambient air quality data from 
1999 through 2004. Further, we have reviewed ambient air quality data 
from 2005 and 2006 and the Longmont area shows continuous attainment of 
the CO NAAQS from 1993 to present. All the above-referenced air quality 
data are archived in our Aerometric Information and Retrieval System 
(AIRS).
    (b) Using the MOBILE6.2 emission factor model, the State updated 
the attainment year, projected years and the maintenance year emission 
inventories.
    (1) The State updated the attainment year (2001), projected years 
(2009, 2010, 2013, 2015, 2020) and the maintenance year (2021) emission 
inventories for Denver's revised CO maintenance plan.
    Denver's revised CO maintenance plan submitted on September 25, 
2006, included comprehensive inventories of CO emissions for the Denver 
area. These inventories include emissions from stationary point 
sources, area sources, non-road mobile sources, and on-road mobile 
sources. More detailed descriptions of the 2001 attainment year 
inventory, the revised 2013 projected inventory, the new 2009, 2010, 
2015, and 2020 projected inventories, and the 2021 maintenance year 
projected inventory are documented in the revised maintenance plan in 
section C, ``Emission Inventories'' and in the State's Technical 
Support Document (TSD). The State's submittal contains emission 
inventory information that was prepared in accordance with EPA 
guidance. Summary emission figures from the 2001 attainment year and 
the projected years are provided in Table IV-1 below.

                         Table IV-1.--Summary of CO Emissions in Tons per Day for Denver
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                                                     2001     2009     2010     2013     2015     2020     2021
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Point Sources....................................     15.3     18.1     18.5     19.8     20.4     22.9     23.3
Area Sources.....................................     74.1     80.5     81.2     83.4     84.9     88.7     89.4
Non-Road Mobile Sources..........................    199.4    239.0    241.3    245.6    250.4    262.6    265.6
On-Road Mobile Sources...........................   1708.1   1476.8   1523.9   1429.2   1416.0   1362.7   1372.1

[[Page 46151]]

 
    Total........................................   1997.0   1814.5   1864.9   1778.1   1771.7   1736.9  1750.3
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Note: The significant figures in this table are used to show the small contribution of certain source
  categories. They are not intended to indicate a level of accuracy in the inventories. Totals may not add due
  to rounding.

    (2) The State updated the attainment year (1993), projected years 
(2009, 2010, 2015) and the maintenance year (2020) emission inventories 
for Longmont's revised CO maintenance plan.
    Longmont's revised CO maintenance plan submitted on September 25, 
2006, included comprehensive inventories of CO emissions for the 
Longmont area. These inventories include emissions from stationary 
point sources, area sources, non-road mobile sources, and on-road 
mobile sources. More detailed descriptions of the 1993 attainment year 
inventory, the revised 2010, and 2015 projected inventories, the new 
2009 projected inventory, and the 2020 maintenance year projected 
inventory are documented in the revised maintenance plan in section C, 
``Emission Inventories and Maintenance Demonstration,'' and in the 
State's TSD. The State's submittal contains emission inventory 
information that was prepared in accordance with EPA guidance. Summary 
emission figures from the 1993 attainment year and the projected years 
are provided in Table IV-2 below.

                        Table IV-2.--Summary of CO Emissions in Tons per Day for Longmont
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               Source category                     1993          2009         2010         2015          2020
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Point........................................         0.18         0.053        0.055         0.059        0.066
Area.........................................         3.503        2.948        2.956         3.0          3.048
Non-Road Mobile..............................         6.36         5.983        6.012         5.829        5.988
On-Road Mobile...............................        43.255       39.952       40.452        36.459       35.456
                                              ------------------------------------------------------------------
    Total....................................        53.298       48.938       49.565        45.348       44.558
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    Note: The significant figures in this table are used to show the 
small contribution of certain source categories. They are not 
intended to indicate a level of accuracy in the inventories. Totals 
may not add due to rounding.


    The State's approach follows EPA guidance on projected emissions 
and we believe it is acceptable.\1\ Further information on these 
projected emissions may also be found in the State's TSD. The revised 
mobile source emissions show the largest change from the original and 
previously revised maintenance plans and this is primarily due to the 
removal of the vehicle inspection/maintenance (I/M) (Regulation No. 11) 
and oxygenated fuels (Regulation No. 13) programs, effective January 1, 
2008. The phase-out of residual I/M program benefits is estimated in 
the 2009 and 2010 analysis years. January 1, 2009 will have half the 
benefit of a biennial I/M program and January 1, 2010 will have no 
residual benefit due to the I/M program. The MOBILE6.2 modeling 
information is contained in the State's TSD. Much of the modeling data, 
input-output files, fleet makeup, MOBILE6.2 input parameters, etc. are 
on a compact disc (CD), included with the docket for this action, and 
available from either EPA or the State. Other revisions to the mobile 
sources categories were due to revised vehicle miles traveled (VMT) 
estimates that were provided to the State from the Denver Regional 
Council of Governments (DRCOG) which is the metropolitan planning 
organization (MPO) for both the Denver and Longmont areas. The revised 
VMT were extracted from DRCOG's 2030 Regional Transportation Plan of 
January, 2005. In summary, the revised maintenance plans and State TSDs 
contain detailed emission inventory information, that was prepared in 
accordance with EPA guidance, and are acceptable to EPA.
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    \1\ ``Use of Actual Emissions in Maintenance Demonstrations for 
Ozone and Carbon Monoxide (CO) Nonattainment Areas'', signed by D. 
Kent Berry, Acting Director, Air Quality Management Division, 
November 30, 1993.
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    (c) The State revised the maintenance demonstration used in the 
original and previously revised maintenance plans.
(1) Denver
    The original Denver CO redesignation maintenance plan, approved on 
December 14, 2001, was revised and approved by EPA on September 16, 
2004. The State has revised and updated the maintenance plan for a 
second ten-year period beyond redesignation.
    The September 25, 2006 revised maintenance plan updated mobile 
source CO emissions with MOBILE6.2, based on the pending removal of 
Regulation No. 11, the vehicle I/M program and Regulation No. 13, the 
oxygenated fuels program (from the CO maintenance plan), and using the 
most recent planning assumptions for the Denver metropolitan area from 
DRCOG's 2030 Regional Transportation Plan (RTP). The modeling domain-
wide vehicle miles traveled (VMT) are presented in section C.2.(a) of 
Denver's revised CO maintenance plan and Table IV-3 below.

                                        Table IV-3.--Estimated Daily VMT
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                      Year                           2001         2005         2015         2020         2030
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                                                  57,984,600   61,842,200   77,544,600   84,765,600   98,499,600
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[[Page 46152]]

    Section C.2.(b) of Denver's revised CO maintenance plan contains a 
discussion of the State's assessment of point source emissions. Point 
source inventories were updated including new sources permitted since 
the previously approved maintenance plan. The State indicates point 
sources have little or no impact on the maintenance demonstration, 
consistent with what EPA has approved in previous maintenance plans. We 
find the State's overall analysis of revised point source emissions 
acceptable.
    For the non-road and area source emissions, the State relied upon 
updated demographic information from DRCOG. Several of the non-road and 
area source emissions are dependent on demographic data as a surrogate 
emission factor. DRCOG demographics are presented below from section 
C.1 (Table 4) of Denver's revised CO maintenance plan and a further 
discussion is presented in the State's TSD.

                                            Table IV-4.--Demographics
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                      Year                           2001         2005         2015         2020         2030
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Population.....................................    2,304,700    2,454,300    2,853,200    3,099,300    3,591,600
Households.....................................      916,480      988,000    1,156,300    1,262,300    1,474,400
Employment.....................................    1,306,800    1,267,100    1,612,300    1,721,300    1,939,500
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    We have concluded that the revised maintenance demonstration is 
approvable.
(2) Longmont
    The original Longmont CO redesignation maintenance plan, approved 
on September 24, 1999, was revised and approved by EPA on September 30, 
2004. The State has revised and updated the maintenance plan for a 
second ten-year period beyond redesignation.
    This revised maintenance plan updated mobile source CO emissions 
with MOBILE6.2, based on the pending removal of Regulation No. 11 and 
Regulation No. 13 (from the CO maintenance plan), and using the latest 
transportation and demographic data from DRCOG. All emission source 
categories (point, area, non-road, and mobile) were updated using the 
latest version of applicable models (including MOBILE6.2), 
transportation data sets, emissions data, emission factors, population 
figures and other demographic information. As discussed above, the 
State prepared emission inventories for the years 1993, 2009, 2010, 
2015 and 2020. The results of these calculations are presented in Table 
3, ``1993-2020 Longmont CO Attainment Area Emissions (Tons per Day),'' 
on page 7 of the Longmont CO revised maintenance plan and are also 
summarized in our Table IV-2 above. Emissions for all future years are 
less than emissions for the 1993 attainment year. Therefore, 
maintenance of the CO NAAQS is demonstrated and is approvable.
(d) Monitoring Network and Verification of Continued Attainment
    Continued attainment of the CO NAAQS in both the Denver and 
Longmont areas depend, in part, on the State's efforts to track 
indicators throughout the maintenance period. This requirement is met 
in section F, ``Monitoring Network/Verification of Continued 
Attainment'' of the revised Denver CO maintenance plan and section E, 
``Monitoring Network/Verification of Continued Attainment'' of the 
revised Longmont CO maintenance plan. In these sections, the State 
commits to continue operating the CO monitors in both the Denver and 
Longmont areas, and to annually review the monitoring networks and make 
changes as appropriate.
    Also, in these sections, the State commits to track CO emissions 
from mobile sources (which are the largest component of the 
inventories) through the ongoing regional transportation planning 
process done by DRCOG. Since regular revisions to the transportation 
improvement programs are prepared every two years, and must go through 
a transportation conformity finding, the State will use this process to 
periodically review the Vehicle Miles Traveled (VMT) and mobile source 
emissions projections used in the revised maintenance plans. This 
regional transportation process is conducted by DRCOG in coordination 
with the Regional Air Quality Council (RAQC) (in Denver), the City of 
Longmont (in Longmont), the State's Air Pollution Control Division 
(APCD), the Colorado Air Quality Control Commission (AQCC), and EPA.
    Based on the above, we are approving these commitments as 
satisfying the relevant requirements[R3] from ``Procedures 
for Processing Requests to Redesignate Areas to Attainment,'' signed by 
John Calcagni, Director, Air Quality Management Division, September 4, 
1992. We note that our final rulemaking approval renders the State's 
commitments federally enforceable. These commitments are also the same 
as those we approved in the original and the previously revised 
maintenance plans.
(e) Contingency Plan
    Section 175A(d) of the CAA requires that a maintenance plan include 
contingency provisions. To meet this requirement, the State has 
identified appropriate contingency measures along with a schedule for 
the development and implementation of such measures.
    As stated in section G of the revised Denver CO maintenance plan 
and section F of the revised Longmont CO maintenance plan, the 
contingency measures for both the Denver and Longmont areas will be 
triggered by a violation of the CO NAAQS. (However, the maintenance 
plans note that an exceedance of the CO NAAQS may initiate a voluntary, 
local process by the RAQC (in Denver) or the City of Longmont (in 
Longmont), and APCD to identify and evaluate potential contingency 
measures.)
    The RAQC (in Denver) or the City of Longmont (in Longmont), in 
coordination with the APCD and AQCC, will initiate a subcommittee 
process to begin evaluating potential contingency measures no more than 
60 days after being notified by the APCD that a violation of the CO 
NAAQS has occurred. The subcommittee will present recommendations 
within 120 days of notification and recommended contingency measures 
will be presented to the AQCC within 180 days of notification. The AQCC 
will then hold a public hearing to consider the recommended contingency 
measures, along with any other contingency measures that the AQCC 
believes may be appropriate to effectively address the violation of the 
CO NAAQS. The necessary contingency measures will be adopted and 
implemented within one year after the violation occurs.
    The potential contingency measures that are identified in section 
G.1 of Denver's revised CO maintenance plan and section F.3 of 
Longmont's revised CO maintenance plan include: (1) A

[[Page 46153]]

3.1% oxygenated fuels program from November 8 through February 7, with 
a 2.0% oxygen content required from November 1 through November 7, and 
(2) reinstatement of the enhanced I/M program in effect before January 
10, 2000. Denver's revised CO maintenance plan also includes a third 
potential contingency measure: Transportation Control Measures (TCM) 
such as financial incentives for Ecopass, Auraria transit pass, and 
improved traffic signalization. Longmont's revised CO maintenance plan 
also includes a third potential contingency measure: Nonattainment New 
Source Review permitting requirements.
    Based on the above, we find that the contingency measures provided 
in Denver's and Longmont's revised CO maintenance plans are sufficient 
and meet the requirements of section 175A(d) of the CAA. We note the 
contingency measures and methodology to implement them are the same as 
those we approved in the original and previously revised maintenance 
plans.
(f) Subsequent Maintenance Plan Revisions
(1) Denver
    The previously approved maintenance plan addressed the period 2001 
through 2013 and demonstrated, in accordance with section 175A(a) of 
the CAA, that the CO standard will be maintained for the initial ten-
year period (through 2011). In accordance with section 175A(b), 
Colorado has submitted a revised maintenance plan eight years after our 
approval of the original redesignation. The purpose of this revised 
maintenance plan is to provide for maintenance of the CO standard for 
the additional ten years (through 2021) following the first ten-year 
period.
(2) Longmont
    The previously approved maintenance plan addressed the period 1999 
through 2009 and demonstrated, in accordance with section 175A(a) of 
the CAA, that the CO standard will be maintained for the initial ten-
year period (through 2009). In accordance with section 175A(b), 
Colorado has submitted a revised maintenance plan eight years after our 
approval of the original redesignation. The purpose of this revised 
maintenance plan is to provide for maintenance of the CO standard for 
the additional ten years (through 2020) following the first ten-year 
period.
    Based on our review of the components of the revised Denver and 
Longmont CO maintenance plans, as discussed in items IV.(a) through 
IV.(f) above, we have concluded that the State has met the necessary 
requirements for us to fully approve the revised Denver and Longmont CO 
maintenance plans. It is important to note that neither the maintenance 
plans nor the control measures relied upon in these maintenance plans 
simply go away after the maintenance year (2021 for Denver, 2020 for 
Longmont). Both the maintenance plans and control measures relied upon 
in these maintenance plans will continue to be a part of Colorado's SIP 
unless we approve their removal. Both maintenance plans will remain in 
effect until they are revised and we approve the revision.

V. EPA's Evaluation of the Transportation Conformity Requirements

    One key provision of our conformity regulation requires a 
demonstration that emissions from the Long Range Transportation Plan 
and the Transportation Improvement Program are consistent with the 
emissions budgets in the SIP (40 CFR 93.118 and 93.124). The emissions 
budgets are defined as the level of mobile source emissions relied upon 
in the attainment or maintenance demonstration to maintain compliance 
with the NAAQS in the nonattainment or maintenance area. The rule's 
requirements and EPA's policy on emissions budgets are found in the 
preamble to the November 24, 1993, transportation conformity rule (58 
FR 62193-62196) and in the sections of the rule referenced above. With 
respect to maintenance plans, our conformity regulation requires that 
motor vehicle emission budgets (MVEBs) must be established for the last 
year of the maintenance plan and may be established for any other years 
deemed appropriate (40 CFR 93.118).
    For transportation plan analysis years after the last year of the 
maintenance plan, a conformity determination must show that emissions 
are less than or equal to the maintenance plan's MVEBs for the last 
year of the implementation plan. EPA's conformity regulation (40 CFR 
93.124) also allows the implementation plan to quantify explicitly the 
amount by which motor vehicle emissions could be higher while still 
demonstrating compliance with the maintenance requirement. The 
implementation plan can then allocate some, or all, of this additional 
safety margin to the emissions budgets for transportation conformity 
purposes.
(1) Denver
    Section E.2 of the revised Denver CO maintenance plan describes the 
applicable transportation conformity requirements and updated MVEBs for 
the revised Denver CO maintenance plan. The State has established a 
MVEB for 2013 through 2020 and 2021 and beyond. Specifically, the CO 
MVEBs are defined as 1625 tons per day for 2013 through 2020, and 1600 
tons per day for 2021 and beyond. As we explain more fully below, we 
view these as the budgets for 2013, and 2021 respectively.
    Under our conformity rules, a MVEB is established for a given year, 
not for a range of years. This is because the MVEB reflects the 
inventory value for motor vehicle emissions in a given year, plus, 
potentially, any safety margin in that year. (We explain the concept of 
safety margin more fully below.) It is not possible to specify the same 
MVEB for a range of years absent specific analysis supporting the 
derivation of that budget for each year in the range. As a practical 
matter, this is not usually important because our conformity rules also 
say that a MVEB for a particular year applies for conformity analyses 
of emissions in that year and all subsequent years before the next 
budget year. See 40 CFR 93.118(b)(1)(ii), ``Emissions in years for 
which no motor vehicle emissions budget(s) are specifically established 
must be less than or equal to the motor vehicle emissions budget(s) 
established for the most recent prior year.'' Therefore, the ``2013 
through 2020'' and the ``2021 and beyond'' budgets were derived from, 
the 2013 and 2021 inventory values, respectively, for on-road vehicle 
emissions and available safety margin. Thus, we will refer to these as 
the 2013 and 2021 budgets in the remainder of this action.
    Section E. ``Carbon Monoxide Motor Vehicle Emissions Budget'' of 
the revised Denver CO maintenance plan describes the applicable 
transportation conformity requirements and updated MVEBs. The State has 
revised the 2013 MVEB, and established a new MVEB for the last year of 
the revised maintenance plan, 2021. Based on this, in order for a 
positive conformity determination to be made, transportation plan 
analyses for years between 2013 and 2020 must show that motor vehicle 
emissions will be less than or equal to the MVEB in 2013. In addition, 
transportation plan analyses for years after 2021 must show that motor 
vehicle emissions will be less than or equal to the MVEB in 2021. Our 
conformity regulation also allows the implementation plan (maintenance 
plan in this case) to quantify explicitly the

[[Page 46154]]

amount motor vehicle emissions that could be higher in 2013, while 
allowing a demonstration of maintenance of the NAAQS (40 CFR 93.124). 
This process is known as allocating all or a portion of the designated 
safety margin to the MVEB and is further described in 40 CFR 93.124 and 
below.
    In addition, our January 18, 2002 MOBILE6 policy states that `` * * 
* regardless of the technique used for attainment or maintenance 
demonstrations, a more rigorous assessment of the SIP's demonstration 
may be necessary if a State decides to reallocate possible excess 
emission reductions to the motor vehicle emissions budget safety 
factor.'' Since the State decided to allocate available excess 
emissions reductions in the revised maintenance plan to the 2013 and 
2021 MVEBs, we required a ``more rigorous assessment'' in order to 
ensure that even with the allocation of safety margin to the 2013 and 
2021 MVEBs, the revised maintenance plan would continue to demonstrate 
maintenance. The ``more rigorous assessment'' is described in section 
E.2 of the revised Denver CO maintenance plan, in the State's TSD, and 
below.
    In section E.2 of the revised Denver CO maintenance plan, the State 
revises the 2013 MVEB and establishes a MVEB for 2021 and these MVEBs 
are applicable to the boundaries of the Denver CO attainment/
maintenance area. The revised maintenance plan estimates the available 
safety margin using the EPA recommended ``more rigorous assessment'' 
methodology and allocates a portion of the available safety margin to 
the MVEBs in 2013 and 2021 as illustrated in Table V-2 below.

 Table V-2.--Derivation of the MVEBs for 2013 and 2021 and Allocation of
                            the Safety Margin
------------------------------------------------------------------------
          Budget years             2013   2021         Explanation
------------------------------------------------------------------------
2001 Total Attainment Inventory.   1997   1997  2001 attainment year
                                                 inventory from all
                                                 sources that
                                                 established attainment
                                                 level of emissions in
                                                 the attainment/
                                                 maintenance area.
Area and Point Source Emissions.    349    378  Total estimated
                                                 emissions from point
                                                 and area sources.
Mobile Source Emissions.........   1429   1372  Estimated mobile source
                                                 emissions based on
                                                 MOBILE6.2 and State
                                                 control strategies.
Total Emission Inventory........   1778   1750
Potential Safety Margin.........    219    247  Difference between the
                                                 2001 and 2013 and 2021
                                                 total emission
                                                 inventories,
                                                 respectively.
Allowable Mobile Source            1648   1619  Total mobile source
 Emissions.                                      emissions that
                                                 demonstrate maintenance
                                                 of the CO NAAQS based
                                                 on EPA's recommended
                                                 ``more rigorous
                                                 assessment''.
Available Safety Margin.........    219    247  Difference between
                                                 allowable mobile source
                                                 emissions and estimated
                                                 mobile source emissions
                                                 which equals the
                                                 available safety margin
                                                 that may be allocated
                                                 to the MVEB.
Portion of the Safety Margin         23     19  Portion of the available
 Reserved.                                       safety margin that is
                                                 reserved to account for
                                                 point/area growth and
                                                 other modeling
                                                 uncertainties.
Safety Margin allocated to the      196    228  Difference between
 MVEB.                                           available safety margin
                                                 and the reserved safety
                                                 margin.
2013 and 2021 MVEBs.............   1625   1600  Total of estimated
                                                 mobile source emissions
                                                 and safety margin
                                                 assigned to the budget,
                                                 which establishes the
                                                 MVEB for 2013 and 2021.
------------------------------------------------------------------------

    As stated above, our January 18, 2002 MOBILE6 policy required a 
``more rigorous assessment'' in order to ensure that even with the 
allocation of safety margin emissions to the MVEBs, the revised 
maintenance plan would continue to demonstrate maintenance. We 
determined that a ``more rigorous assessment'' for the revised Denver 
CO maintenance plan would be an intersection modeling analysis similar 
to that performed by the State for the original EPA-approved Denver CO 
maintenance plan and the previously revised EPA-approved Denver CO 
maintenance plan. The State's intersection analysis used a background 
CO concentration combined with CAL3QHC intersection (``hot spot'') 
modeling of the same six high-volume, high congestion intersections 
that were analyzed for the original and previously revised maintenance 
plan.
    The background CO concentration for each intersection used the 
second highest 8-hour maximum monitored value at a nearby CO ambient 
air quality monitor for the time period of 2000 through 2002. The 
CAL3QHC intersection modeling used 2013 and 2021 MOBILE6.2 mobile 
sources emissions and DRCOG projected traffic data. The background 
concentration and results from the CAL3QHC modeling were then combined 
for each intersection. If the resulting concentration was greater than 
9 ppm (the CO NAAQS), the background concentration was reduced by the 
necessary percentage to bring the total intersection value below 9 ppm. 
Since it is assumed that background concentrations are influenced by 
regional emissions of CO, the State, in order to determine the 
allowable regional emissions, reduced the base regional emissions (1997 
tons per day in 2001) by the same percentage it had to reduce the 
initial background concentration.
    The State modeled the six intersections based on the 2013 MVEB of 
1625 tons per day and the 2021 MVEB of 1600 tons per day of CO. The 
results are shown in Table 13 on page 23, of the State's revised 
maintenance plan and are reproduced in Table V-3 below.

                Table V-3.--Intersection Modeling Results
                         [In parts per million]
------------------------------------------------------------------------
                                                          2013     2021
                     Intersection                        Total    Total
                                                          ppm      ppm
------------------------------------------------------------------------
28th & Arapahoe (Boulder).............................      7.8      7.3
University & Belleview................................      7.1      6.8
University & 1st Ave..................................      7.5      7.1
Foothills & Arapahoe (Boulder)........................      7.3      6.9
Wadsworth & Alameda...................................      6.5      6.0
20th & Broadway (CAMP)................................      6.6      6.5
------------------------------------------------------------------------

    The modeling results presented in the revised Denver CO maintenance 
plan and the State's TSD, and repeated in Table V-3 above, show that CO 
concentrations are not estimated to exceed the 9.0 ppm 8-hour average 
CO NAAQS for 2013 or 2021. We have concluded that the State has 
satisfactorily addressed the requirements of our January 18, 2002 
MOBILE6 policy for a ``more rigorous assessment'' of MVEBs and has also 
demonstrated maintenance of the CO NAAQS while using a transportation 
conformity MVEB of 1625 tons per day

[[Page 46155]]

for 2013 and 1600 tons per day for 2021. Therefore, we are approving 
the transportation conformity MVEB of 1625 tons per day of CO, for the 
Denver attainment/maintenance area, for 2013 and 1600 tons per day of 
CO, for the Denver attainment/maintenance area, for 2021.
    Pursuant to Sec.  93.118(e)(4) of EPA's transportation conformity 
rule, as amended, EPA must determine the adequacy of submitted MVEBs. 
EPA reviewed the Denver CO 2021 budget for adequacy using the criteria 
in 40 CFR 93.118(e)(4), and determined that the 2021 budget was 
adequate for conformity purposes. EPA's adequacy determination was made 
in a letter to the State on May 3, 2007, and was announced in the 
Federal Register on June 13, 2007 (72 FR 32646). As a result of this 
adequacy finding, the 2021 budget took effect for conformity 
determinations in the Denver area on June 28, 2007. However, we are not 
bound by that determination in acting on the maintenance plan.
(2) Longmont
    Section D, ``Transportation Conformity and Mobile Source Carbon 
Monoxide Emission Budgets,'' of the Longmont CO revised maintenance 
plan briefly describes the applicable transportation conformity 
requirements, provides MVEB calculations, identifies safety margin, and 
indicates that the City of Longmont and DRCOG elected to apply the 
identified safety margin to the MVEB for 2010 through 2014, 2015 
through 2019, and 2020 and beyond. Specifically, the CO MVEBs are 
defined as 43 tons per day for 2010 through 2014, 43 tons per day for 
2015 through 2019, and 43 tons per day for 2020 and beyond. As we 
explained more fully above in V.(1), ``Denver,'' we view these as the 
budgets for 2010, 2015, and 2020 respectively.
    For the revised Longmont CO maintenance plan, the safety margin is 
the difference between the attainment year (1993) total emissions and 
the projected future year's total emissions. Part, or all, of the 
safety margin may be added to projected mobile source CO emissions to 
arrive at a motor vehicle emissions budget to be used for 
transportation conformity purposes. The safety margins, less one ton 
per day, were added to projected mobile source CO emissions for 2010, 
2015, and 2020. The derivation and determination of safety margins and 
motor vehicle emissions budgets for the Longmont CO maintenance plan is 
further illustrated in Table V-4 below and in section D of the revised 
maintenance plan.

            Table V-4.--Mobile Sources Emissions, Safety Margins, and Motor Vehicle Emissions Budgets
                                           In Tons of CO per Day (tpd)
----------------------------------------------------------------------------------------------------------------
                                   Mobile
                                   source       Total                                Margin of     Motor vehicle
             Year                emissions    emissions            Math            safety  (tpd)     emission
                                   (tpd)        (tpd)                                              budget  (tpd)
----------------------------------------------------------------------------------------------------------------
1993..........................  ...........       53.298
2010..........................       40.452       49.565  53.298 - 49.565 =                2.733              43
                                                           3.733.
                                                          3.733 - 1 = 2.733.....
                                                          2.733 + 40.452 =
                                                           43.185.
2015..........................       36.459       45.348  53.298 - 45.348 = 7.95            6.95              43
                                                          7.95 - 1 = 6.95.......
                                                          6.95 + 36.459 = 43.409
2020..........................       35.456       44.558  53.298 - 44.558 = 8.74            7.74              43
                                                          8.74 - 1 = 7.74.......
                                                          7.74 + 35.456 = 43.196
----------------------------------------------------------------------------------------------------------------

    Our analysis indicates that the above figures are consistent with 
maintenance of the CO NAAQS throughout the maintenance period. 
Therefore, we are approving the 43 tons per day CO MVEB for 2010, 2015, 
and 2020 for the Longmont area.
    As described above, EPA must determine the adequacy of submitted 
MVEBs. EPA reviewed the Longmont CO 2020 budget for adequacy using the 
criteria in 40 CFR 93.118(e)(4), and determined that the 2020 budget 
was adequate for conformity purposes. EPA's adequacy determination was 
made in a letter to the State on May 3, 2007, and was announced in the 
Federal Register on June 13, 2007 (72 FR 32646). As a result of this 
adequacy finding, the 2020 budget took effect for conformity 
determinations in the Longmont area on June 28, 2007. However, we are 
not bound by that determination in acting on the maintenance plan.

VI. EPA's Evaluation of the Regulation No. 11 Revisions

    Colorado's Regulation No. 11 is entitled, ``Motor Vehicle Emissions 
Inspection Program.'' In developing the revised Denver and Longmont CO 
maintenance plans, the State conducted a comprehensive reevaluation of 
mobile source control programs with MOBILE6.2 and the latest 
transportation sets from DRCOG's 2030 Regional Transportation Plan. 
Based on the results from the modeling demonstration in the State's TSD 
[R4], Colorado's Regulation No. 11 can be removed from the 
revised Denver and Longmont CO maintenance plans effective December 31, 
2007. These revised maintenance plans reflect the removal of Regulation 
No. 11 in that the mobile source CO emissions were calculated without 
the CO emissions reduction benefit of an inspection and maintenance (I/
M) program starting January 1, 2008 and continuing through 2021 for 
Denver and 2020 for Longmont. The phase-out of residual I/M program 
benefits is estimated in the 2009 and 2010 analysis years. January 1, 
2009 will have half the benefit of a biennial I/M program and January 
1, 2010 will have no residual benefit due to the I/M program. Even with 
the elimination of the I/M program from the revised Denver and Longmont 
CO maintenance plans beginning on January 1, 2008, the areas were still 
able to meet our requirements to demonstrate maintenance of the CO 
standard through 2021 for Denver and 2020 for Longmont.
    We note that the removal of the I/M program from Denver's revised 
CO maintenance plan does not mean the I/M program is eliminated. The 
State relies on the I/M program in Denver's 1-hour ozone maintenance 
plan and Denver's 8-hour ozone Early Action Compact (EAC). Therefore, 
the motor vehicle I/M program will remain intact in the Denver-metro 
area. We have

[[Page 46156]]

reviewed and are approving the removal of Regulation No. 11 from the 
revised Denver and Longmont CO maintenance plans.
    Additionally, we note that the State had made previous revisions to 
Regulation No. 11 regarding the repeal of the basic vehicle emissions 
inspection program in the Fort Collins and Greeley areas that were 
adopted by the Colorado AQCC on November 17, 2005, and submitted to us 
for approval by the Governor on August 8, 2006. We previously approved 
Fort Collins' and Greeley's revised CO maintenance plans which 
eliminated the Basic I/M program from the Federal SIP on July 22, 2003 
and August 19, 2005, respectively (68 FR 43316 and 70 FR 48650). 
Without the CO emissions reduction benefit of a Basic I/M program, 
these areas were still able to meet our requirements to demonstrate 
maintenance of the CO standard. The August 8, 2006 submittal merely 
clarifies the geographical applicability in Part A.1 and Part A.IV. In 
addition, the August 8, 2006 submittal also eliminates the inspection 
requirement for vehicles that have not yet reached their fourth model 
year, registering in the I/M program area for the first time. This is 
consistent with the regulation and the mobile source modeling that the 
first four model years are exempt from the I/M program. We have 
reviewed and are approving Part A.1 and Part A.IV of Regulation No. 11 
as submitted on August 8, 2006, to repeal the Basic Vehicle Emissions 
Inspection Program in the Fort Collins and Greeley areas.[R5] 
Please note we are not acting on other Regulation No. 11 revisions 
submitted on August 8, 2006 at this time. These other revisions are 
located in Part F and revise the emissions limits for motor vehicle 
exhaust, evaporative and visible emissions for light-duty and heavy-
duty vehicles.

VII. EPA's Evaluation of the Regulation No. 13 Revisions

    Colorado's Regulation No. 13 is entitled, ``Oxygenated Fuels 
Program.'' The purpose of this regulation is to reduce CO emissions 
from gasoline powered motor vehicles through the wintertime use of 
oxygenated gasoline. In developing the revised Denver and Longmont CO 
maintenance plans, the State conducted a comprehensive reevaluation of 
mobile source control programs with MOBILE6.2 and the latest 
transportation sets from DRCOG's 2030 Regional Transportation Plan. 
Based on the results from the modeling demonstration in the State's 
TSD[R6], Colorado's Regulation No. 13 can be removed from 
the revised Denver and Longmont CO maintenance plans effective December 
31, 2007. These maintenance plans reflect the removal of Regulation No. 
13 in that the mobile source CO emissions were calculated without the 
CO emissions reduction benefit of an oxygenated fuels program starting 
January 1, 2008 and continuing through 2021 for Denver and 2020 for 
Longmont. Even with the elimination of the oxygenated fuels program 
from the revised Denver and Longmont CO maintenance plans beginning on 
January 1, 2008, the areas were still able to meet our requirements to 
demonstrate maintenance of the CO standard through 2021 for Denver and 
2020 for Longmont.
    Additionally, we note that the State had made previous revisions to 
Regulation No. 13 regarding methyl tert-butyl ether (MTBE) that were 
adopted by the Colorado AQCC on January 11, 2001, and submitted to us 
for approval by the Governor on July 31, 2002. With our approval of the 
removal of Regulation No. 13 from the revised Denver and Longmont CO 
maintenance plans, the oxygenated fuels program is not federally 
required and will no longer be federally applicable in any area. 
Regulation No. 13 will, however, remain as a state only regulation. 
Therefore, this July 31, 2002 submittal does not require further EPA 
action. We have reviewed and are approving the removal of Regulation 
No. 13 from the revised Denver and Longmont CO maintenance plans.

VIII. Consideration of Section 110(l) of the Clean Air Act

    Section 110(l) of the CAA states that a SIP revision cannot be 
approved if the revision would interfere with any applicable 
requirement concerning attainment and reasonable further progress 
towards attainment of a NAAQS or any other applicable requirement of 
the CAA. As stated above, the revised CO maintenance plans show 
continuous attainment of the CO NAQAQS since 2001 for Denver and 1993 
for Longmont. The revised maintenance plans along with the removal of 
Regulation No. 11 and Regulation No. 13 will not interfere with 
attainment, reasonable further progress, or any other applicable 
requirement of the CAA.

IX. Final Action

    In this action, EPA is approving the revised Denver and Longmont CO 
maintenance plans, that were submitted on September 25, 2006, and we 
are also approving the revised transportation conformity motor vehicle 
emission budgets for CO for the years 2013 and 2021 for Denver, and 
2010, 2015, and 2020 for Longmont. Furthermore, we are approving the 
removal of Regulation No. 11 (I/M) and Regulation No. 13 (Oxygenated 
Fuels) from the revised Denver and Longmont CO maintenance plans.
    EPA is publishing this rule without prior proposal because the 
Agency views this as a noncontroversial amendment and anticipates no 
adverse comments. However, in the ``Proposed Rules'' section of today's 
Federal Register publication, EPA is publishing a separate document 
that will serve as the proposal to approve the SIP revision if adverse 
comments are filed. This rule will be effective October 16, 2007 
without further notice unless the Agency receives adverse comments by 
September 17, 2007. If the EPA receives adverse comments, EPA will 
publish a timely withdrawal in the Federal Register informing the 
public that the rule will not take effect. EPA will address all public 
comments in a subsequent final rule based on the proposed rule. The EPA 
will not institute a second comment period on this action. Any parties 
interested in commenting must do so at this time. Please note that if 
EPA receives adverse comment on an amendment, paragraph, or section of 
this rule and if that provision may be severed from the remainder of 
the rule, EPA may adopt as final those provisions of the rule that are 
not the subject of an adverse comment.

X. Statutory and Executive Order Reviews

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is not a ``significant regulatory action'' and therefore is not 
subject to review by the Office of Management and Budget. For this 
reason, this action is also not subject to Executive Order 13211, 
``Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This action 
merely approves state law as meeting Federal requirements and imposes 
no additional requirements beyond those imposed by state law. 
Accordingly, the Administrator certifies that this rule will not have a 
significant economic impact on a substantial number of small entities 
under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Because 
this rule approves pre-existing requirements under state law and does 
not impose any additional enforceable duty beyond that required by 
state law, it does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the

[[Page 46157]]

Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4).
    This rule also does not have tribal implications because it will 
not have a substantial direct effect on one or more Indian tribes, on 
the relationship between the Federal Government and Indian tribes, or 
on the distribution of power and responsibilities between the Federal 
Government and Indian tribes, as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000). This action also does not have Federalism 
implications because it does not have substantial direct effects on the 
States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government, as specified in Executive Order 13132 (64 
FR 43255, August 10, 1999). This action merely approves a state rule 
implementing a Federal standard, and does not alter the relationship or 
the distribution of power and responsibilities established in the Clean 
Air Act. This rule also is not subject to Executive Order 13045 
``Protection of Children from Environmental Health Risks and Safety 
Risks'' (62 FR 19885, April 23, 1997), because it is not economically 
significant.
    In reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. In 
this context, in the absence of a prior existing requirement for the 
State to use voluntary consensus standards (VCS), EPA has no authority 
to disapprove a SIP submission for failure to use VCS. It would thus be 
inconsistent with applicable law for EPA, when it reviews a SIP 
submission, to use VCS in place of a SIP submission that otherwise 
satisfies the provisions of the Clean Air Act. Thus, the requirements 
of section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (15 U.S.C. 272 note) do not apply. This rule does not 
impose an information collection burden under the provisions of the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).
    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2).
    Under section 307(b)(1) of the Clean Air Act, petitions for 
judicial review of this action must be filed in the United States Court 
of Appeals for the appropriate circuit by October 16, 2007. Filing a 
petition for reconsideration by the Administrator of this final rule 
does not affect the finality of this rule for the purposes of judicial 
review nor does it extend the time within which a petition for judicial 
review may be filed, and shall not postpone the effectiveness of such 
rule or action. This action may not be challenged later in proceedings 
to enforce its requirements. (See section 307(b)(2).)

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Reporting and 
recordkeeping requirements.

    Dated: July 31, 2007.
Kerrigan G. Clough,
Acting Regional Administrator, Region VIII.

0
40 CFR part 52 is amended to read as follows:

PART 52--[AMENDED]

0
1. The authority citation for part 52 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

Subpart G--Colorado

0
2. Section 52.320 is amended by adding paragraph (c)(111) [R7]to read 
as follows:


Sec.  52.320  Identification of plan.

* * * * *
    (c) * * *
    (111) On August 8, 2006, the Governor of Colorado submitted SIP 
revisions to Colorado's Regulation No. 11 ``Motor Vehicle Emissions 
Inspection Program'' that repeals the basic vehicle emissions 
inspection program in the Fort Collins and Greeley areas.
    (i) Incorporation by reference.
    (A) Regulation No. 11 ``Motor Vehicle Emissions Inspection 
Program,'' 5CCR1001-13, Part A.1 and Part A.IV, as adopted on November 
17, 2005, and effective January 30, 2006.
0
3. Section 52.349 is amended by adding paragraphs (m) and (n) to read 
as follows:


Sec.  52.349  Control strategy: Carbon monoxide.

* * * * *
    (m) Revisions to the Colorado State Implementation Plan, revised 
Carbon Monoxide Maintenance Plan for Denver, as adopted by the Colorado 
Air Quality Control Commission on December 15, 2005, State effective on 
March 2, 2006, and submitted by the Governor's designee on September 
25, 2006.
    (n) Revisions to the Colorado State Implementation Plan, revised 
Carbon Monoxide Maintenance Plan for Longmont, as adopted by the 
Colorado Air Quality Control Commission on December 15, 2005, State 
effective on March 2, 2006, and submitted by the Governor's designee on 
September 25, 2006.

[FR Doc. E7-16146 Filed 8-16-07; 8:45 am]
BILLING CODE 6560-50-P