[Federal Register Volume 66, Number 163 (Wednesday, August 22, 2001)]
[Proposed Rules]
[Pages 44097-44107]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-21197]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[CO-001-0045; CO-001-0046; CO-001-0047; CO-001-0052; CO-001-0053; CO49-
1-7187; CO-001-0061; CO-001-0062; CO-001-0064 FRL-7042-1]


Approval and Promulgation of Air Quality Implementation Plans; 
State of Colorado; Denver Carbon Monoxide Redesignation to Attainment, 
Designation of Areas for Air Quality Planning Purposes, and Approval of 
Related Revisions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: On May 10, 2000, the Governor of Colorado submitted a request 
to redesignate the Denver-Boulder metropolitan (hereafter, Denver) 
``serious'' carbon monoxide (CO) nonattainment area to attainment for 
the CO National Ambient Air Quality Standard (NAAQS). The Governor also 
submitted a CO maintenance plan. In conjunction with the maintenance 
plan, the Governor submitted revisions to Colorado's Regulation No. 11 
``Motor Vehicle Emissions Inspection Program'', and Colorado's 
Regulation No. 13 ``Oxygenated Fuels Program''. In addition, on May 7, 
2001, the Governor submitted a revision to the Colorado State 
Implementation Plan (``United States Postal Service (USPS) revision'') 
that is intended to be a substitute for a Clean Fuel Fleet Program. In 
this action, EPA is proposing approval of the Denver CO redesignation 
request, the maintenance plan, the revisions to Regulation No. 11 and 
Regulation No. 13, and the USPS revision.

DATES: Written comments must be received on or before September 21, 
2001.

ADDRESSES: Written comments may be mailed to:
    Richard R. Long, Director, Air and Radiation Program, Mailcode 8P-
AR, United States Environmental Protection Agency, Region VIII, 999 
18th Street, Suite 300, Denver, Colorado 80202-2466.
    Copies of the documents relevant to this action are available for 
public inspection during normal business hours at the following 
offices:

United States Environmental Protection Agency, Region VIII, Air and 
Radiation Program, 999 18th Street, Suite 300, Denver, Colorado 80202-
2466; and,

[[Page 44098]]

United States Environmental Protection Agency, Air and Radiation Docket 
and Information Center, 401 M Street, SW, Washington, DC 20460.

    Copies of the State documents relevant to this action are available 
for public inspection at: Colorado Air Pollution Control Division, 
Colorado Department of Public Health and Environment, 4300 Cherry Creek 
Drive South, Denver, Colorado, 880246-1530.

FOR FURTHER INFORMATION CONTACT: For Denver redesignation questions, 
contact Tim Russ, Air and Radiation Program, Mailcode 8P-AR, United 
States Environmental Protection Agency, Region VIII, 999 18th Street, 
Suite 300, Denver, Colorado 80202-2466, telephone number: (303) 312-
6479.
    For questions regarding the Regulation No. 11, Regulation No. 13, 
and the U.S. Postal Service revisions, contact Kerri Fiedler, Air and 
Radiation Program, Mailcode 8P-AR, United States Environmental 
Protection Agency, Region VIII, 999 18th Street, Suite 300, Denver, 
Colorado 80202-2466, telephone number: (303) 312-6493.

SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we'', 
``us'', or ``our'' are used we mean the Environmental Protection 
Agency.

I. What Is the Purpose of This Action?

    In this action, we are proposing approval of a change in the legal 
designation of the Denver area from nonattainment for CO to attainment, 
we're proposing approval of the maintenance plan that is designed to 
keep the area in attainment for CO for the next 12 years, we're 
proposing approval of changes to the State's Regulation No. 11 for the 
implementation of motor vehicle emissions inspections, we're proposing 
approval of changes to the State's Regulation No. 13 for the 
implementation of the wintertime oxygenated fuels program, and we're 
proposing approval of the USPS revision that requires the destruction, 
relocation, and replacement with cleaner vehicles of certain USPS 
vehicles, as a substitute for a Clean Fuel Fleet Program for the Denver 
metropolitan area.
    We originally designated Denver as nonattainment for CO under the 
provisions of the 1977 CAA Amendments (see 43 FR 8962, March 3, 1978). 
On November 15, 1990, the Clean Air Act Amendments of 1990 were enacted 
(Pub. L. 101-549, 104 Stat. 2399, codified at 42 U.S.C. 7401-7671q). 
Under section 107(d)(1)(C) of the Clean Air Act (CAA), we designated 
the Denver area as nonattainment for CO because the area had been 
designated as nonattainment before November 15, 1990. Under section 186 
of the CAA, Denver was originally classified as a ``moderate'' CO 
nonattainment area with a design value greater than 12.7 parts per 
million (ppm), and was required to attain the CO NAAQS by December 31, 
1995. See 56 FR 56694, November 6, 1991. The Denver area, however, 
violated the CO NAAQS in 1995. With our final rule of March 10, 1997 
(62 FR 10690), we approved the State's 1994 State Implementation Plan 
(SIP) submittal and bumped-up the Denver area to a ``serious'' CO 
nonattainment classification. Further information regarding these 
classifications and the accompanying requirements are described in the 
``General Preamble for the Implementation of Title I of the Clean Air 
Act Amendments of 1990.'' See 57 FR 13498, April 16, 1992.
    Under the CAA, we can change designations if acceptable data are 
available and if certain other requirements are met. See CAA section 
107(d)(3)(D). Section 107(d)(3)(E) of the CAA provides that the 
Administrator may not promulgate a redesignation of a nonattainment 
area to attainment unless:
    (i) the Administrator determines that the area has attained the 
national ambient air quality standard;
    (ii) the Administrator has fully approved the applicable 
implementation plan for the area under CAA section 110(k);
    (iii) the Administrator determines that the improvement in air 
quality is due to permanent and enforceable reductions in emissions 
resulting from implementation of the applicable implementation plan and 
applicable Federal air pollutant control regulations and other 
permanent and enforceable reductions;
    (iv) the Administrator has fully approved a maintenance plan for 
the area as meeting the requirements of CAA section 175A; and,
    (v) the State containing such area has met all requirements 
applicable to the area under section 110 and part D of the CAA.
    Before we can approve the redesignation request, we must decide 
that all applicable SIP elements have been fully approved. Approval of 
the applicable SIP elements may occur simultaneously with final 
approval of the redesignation request. That's why we are also proposing 
approval of the revisions to Regulation No. 11, Regulation No. 13, and 
the USPS revision.

II. 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 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 Denver CO redesignation request, the maintenance plan, 
the revisions to Regulation No. 11, and the revisions to Regulation No. 
13 on January 10, 2000. The AQCC adopted the redesignation request, 
maintenance plan, and revisions to Regulation No. 11 and Regulation No. 
13 directly after the hearing. These SIP revisions became State 
effective March 1, 2000, and were submitted by the Governor to us on 
May 10, 2000.
    We have evaluated the Governor's submittal 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 Governor's submittal was administratively and technically complete. 
Our completeness determination was sent on August 7, 2000, through a 
letter from Rebecca W. Hanmer, Acting Regional Administrator, to 
Governor Bill Owens.
    For the USPS revision, the Colorado AQCC held a public hearing on 
March 16, 2000. The AQCC adopted the USPS revisions directly after the 
hearing. The USPS revision became State effective May 30, 2000, and was 
submitted by the Governor to us on May 7, 2001. On May 30, 2001, the 
Colorado Attorney General's Office submitted administrative corrections 
to the USPS revision to us.
    We have evaluated the Governor's submittal of the USPS revision 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 Governor's submittal, with the 
subsequent administrative corrections, was administratively and 
technically

[[Page 44099]]

complete. Our completeness determination was sent on June 15, 2001, 
through a letter from Jack W. McGraw, Acting Regional Administrator, to 
Governor Bill Owens.

III. EPA's Evaluation of the Denver Redesignation Request and 
Maintenance Plan

    We have reviewed the Denver CO redesignation request and 
maintenance plan and believe that approval of the request is warranted, 
consistent with the requirements of CAA section 107(d)(3)(E). The 
following are descriptions of how the section 107(d)(3)(E) requirements 
are being addressed.
    (a) Redesignation Criterion: The Area Must Have Attained The Carbon 
Monoxide (CO) NAAQS
    Section 107(d)(3)(E)(i) of the CAA states that for an area to be 
redesignated to attainment, the Administrator must determine that the 
area has attained the applicable 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. 
Attainment of the CO standard is not a momentary phenomenon based on 
short-term data. Instead, we consider an area to be in attainment if 
each of the CO ambient air quality monitors in the area doesn't have 
more than one exceedance of the CO standard over a one-year period. 40 
CFR 50.8 and 40 CFR part 50, Appendix C. If any monitor in the area's 
CO monitoring network records more than one exceedance of the CO 
standard during a one-year calendar period, then the area is in 
violation of the CO NAAQS. In addition, our interpretation of the CAA 
and EPA national policy \1\ has been that an area seeking redesignation 
to attainment must show attainment of the CO NAAQS for at least a 
continuous two-year calendar period. In addition, the area must also 
continue to show attainment through the date that we promulgate the 
redesignation in the Federal Register.
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    \1\ Refer to EPA's September 4, 1992, John Calcagni policy 
memorandum entitled ``Procedures for Processing Requests to 
Redesignate Areas to Attainment.''
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    Colorado's CO redesignation request for the Denver area is based on 
an analysis of quality assured ambient air quality monitoring data that 
are relevant to the redesignation request. As presented in Part II, 
Chapter 3, section B of the State's maintenance plan, ambient air 
quality monitoring data for consecutive calendar years 1996 through 
1999 show a measured exceedance rate of the CO NAAQS of 1.0 or less per 
year, per monitor, in the Denver nonattainment area. All of these data 
were collected and analyzed as required by EPA (see 40 CFR 50.8 and 40 
CFR part 50, Appendix C) and have been archived by the State in our 
Aerometric Information and Retrieval System (AIRS) national database. 
Further information on CO monitoring is presented in Part II, Chapter 
3, section B of the maintenance plan and in the State's Technical 
Support Document (TSD). We have evaluated the ambient air quality data 
and have determined that the Denver area has not violated the CO 
standard and continues to demonstrate attainment.
    The Denver nonattainment area has quality-assured data showing no 
violations of the CO NAAQS for 1996 and 1999 which are the years the 
State used to support the redesignation request. In addition, data from 
the most recent consecutive two-calendar-year period (i.e., 1999 and 
2000) also show no violations. Therefore, we believe the Denver area 
has met the first component for redesignation: demonstration of 
attainment of the CO NAAQS. We note too that the State of Colorado has 
also committed, in the maintenance plan, to continue the necessary 
operation of the CO monitors in compliance with all applicable federal 
regulations and guidelines.
    (b) Redesignation Criterion: The Area Must Have Met All Applicable 
Requirements Under Section 110 And Part D Of The CAA.
    To be redesignated to attainment, section 107(d)(3)(E)(v) requires 
that an area must meet all applicable requirements under section 110 
and part D of the CAA. We interpret section 107(d)(3)(E)(v) to mean 
that for a redesignation to be approved by us, the State must meet all 
requirements that applied to the subject area prior to or at the time 
of the submission of a complete redesignation request. In our 
evaluation of a redesignation request, we don't need to consider other 
requirements of the CAA that became due after the date of the 
submission of a complete redesignation request.

1. CAA Section 110 Requirements

    On March 10, 1997, we approved the Denver CO element revisions to 
Colorado's SIP as meeting the requirements of section 110(a)(2) of the 
CAA (see 62 FR 10690). In addition, we have analyzed the SIP elements 
that we are proposing approval of as part of this action and we have 
determined they comply with the relevant requirements of section 
110(a)(2).

2. Part D Requirements

    Before the Denver ``serious'' CO nonattainment area may be 
redesignated to attainment, the State must have fulfilled the 
applicable requirements of part D. Under part D, an area's 
classification indicates the requirements to which it will be subject. 
Subpart 1 of part D sets forth the basic nonattainment requirements 
applicable to all nonattainment areas, whether classified or 
nonclassifiable. Subpart 3 of part D contains specific provisions for 
``serious'' CO nonattainment areas.
    The relevant subpart 1 requirements are contained in sections 
172(c) and 176. Our General Preamble (see 57 FR 13529, 13533, April 16, 
1992) provides EPA's interpretations of the CAA requirements for 
``serious'' CO areas.
    The General Preamble (see 57 FR 13530, et seq.) provides that the 
applicable requirements of CAA section 172 are 172(c)(3) (emissions 
inventory), 172(c)(5) (new source review permitting program), 172(c)(7) 
(the section 110(a)(2) air quality monitoring requirements), and 
172(c)(9) (contingency measures). It is also worth noting that we 
interpreted the requirements of sections 172(c)(2) (reasonable further 
progress--RFP) and 172(c)(6) (other measures) as being irrelevant to a 
redesignation request because they only have meaning for an area that 
is not attaining the standard. See EPA's September 4, 1992, John 
Calcagni memorandum entitled, ``Procedures for Processing Requests to 
Redesignate Areas to Attainment'', and the General Preamble, 57 FR at 
13564, dated April 16, 1992. Finally, the State has not sought to 
exercise the options that would trigger sections 172(c)(4) 
(identification of certain emissions increases) and 172(c)(8) 
(equivalent techniques). Thus, these provisions are also not relevant 
to this redesignation request.
    Regarding the requirements of sections 172(c)(3) (inventory) and 
172(c)(9) (contingency measures), please refer to our discussion below 
of sections 187(a)(1) and 187(a)(3), which are provisions of subpart 3 
of Part D of the CAA that address the same requirements as sections 
172(c)(3) and 172(c)(9).
    For the section 172(c)(5) New Source Review (NSR) requirements, the 
CAA requires all nonattainment areas to meet several requirements 
regarding NSR,

[[Page 44100]]

including provisions to ensure that increased emissions will not result 
from any new or modified stationary major sources and a general offset 
rule. The State of Colorado has a fully-approved NSR program (59 FR 
42500, August 18, 1994) that meets the requirements of CAA section 
172(c)(5). The State also has a fully approved Prevention of 
Significant Deterioration (PSD) program (59 FR 42500, August 18, 1994) 
that will apply if we approve the redesignation to attainment.
    For the CAA section 172(c)(7) provisions (compliance with the CAA 
section 110(a)(2) Air Quality Monitoring Requirements), our 
interpretations are presented in the General Preamble (57 FR 13535). CO 
nonattainment areas are to meet the ``applicable'' air quality 
monitoring requirements of section 110(a)(2) of the CAA.
    Information concerning CO monitoring in Colorado is included in the 
Monitoring Network Review (MNR) prepared by the State and submitted to 
EPA. Our personnel have concurred with Colorado's annual network 
reviews and have agreed that the Denver network remains adequate. In 
Part II, Chapter 4, section D., of the maintenance plan, the State 
commits to the continued operation of the existing CO monitors, 
according to all applicable Federal regulations and guidelines, even 
after the Denver area is redesignated to attainment for CO.
    Section 176 of the CAA contains requirements related to conformity. 
Although EPA's regulations (see 40 CFR 51.396) require that states 
adopt transportation conformity provisions in their SIPs for areas 
designated nonattainment or subject to an EPA-approved maintenance 
plan, we have decided that a transportation conformity SIP is not an 
applicable requirement for purposes of evaluating a redesignation 
request under section 107(d) of the CAA. This decision is reflected in 
EPA's 1996 approval of the Boston carbon monoxide redesignation. (See 
61 FR 2918, January 30, 1996.)
    The relevant Subpart 3 provisions were created when the CAA was 
amended on November 15, 1990. The new CAA requirements for ``serious'' 
CO areas, such as Denver, required that the SIP be revised to include a 
1990 base year emissions inventory (CAA section 187(a)(1)), vehicle 
miles traveled tracking (CAA section 187(a)(2)(A)), a special rule for 
Denver for transportation control measures (TCM) (CAA section 
187(a)(2)(B)), contingency provisions (CAA section 187(a)(3)), 
corrections to existing motor vehicle inspection and maintenance (I/M) 
programs (CAA section 187(a)(4)), periodic emission inventories (CAA 
section 187(a)(5)), enhanced motor vehicle I/M program (CAA section 
187(a)(6)), a modeled attainment demonstration with specific annual 
emissions reductions (CAA section 187(a)(7)), and the implementation of 
an oxygenated fuels program (CAA section 211(m)(1)). How the State met 
these requirements and our approvals, are described in our March 10, 
1997, final rule approving the Denver CO nonattainment area SIP 
revision (see 62 FR 10690). Additional information and further 
discussions on these CAA requirements can also be found in our proposed 
rulemaking regarding the Denver CO SIP revision of July 9, 1996 (61 FR 
36004) and December 6, 1996 (61 FR 64647).
    Regarding section 187(a)(5) of the CAA (periodic emission 
inventories), the Governor submitted a SIP revision for a 1993 periodic 
emission inventory for Denver on September 16, 1997, and a SIP revision 
for a 1996 periodic emission inventory for Denver on May 10, 2000. We 
approved these revisions on July 15, 1998 (see 63 FR 38087) and on 
October 24, 2000 (65 FR 63546), respectively.
    In addition to the above, the requirements for clean-fuel vehicle 
fleets also applied to the Denver area (CAA section 246(a)(2)(B)). We 
describe how the State addressed the clean-fuel requirements in section 
VII below.
    (c) Redesignation Criterion: The Area Must Have A Fully Approved 
SIP Under Section 110(k) Of The CAA
    Section 107(d)(3)(E)(ii) of the CAA states that for an area to be 
redesignated to attainment, it must be determined that the 
Administrator has fully approved the applicable implementation plan for 
the area under section 110(k).
    As noted above, EPA previously approved SIP revisions for the 
Denver CO nonattainment area that were required by the 1990 amendments 
to the CAA (see 62 FR 10690, March 10, 1997). In this action, we are 
also proposing approval of revisions to Colorado's Regulation No. 11 
and Regulation No. 13, the USPS revision, and the State's commitment to 
maintain an adequate monitoring network (contained in the maintenance 
plan.) Thus, with a final rule to approve the Denver redesignation 
request, maintenance plan, revisions to Regulation No. 11 and 
Regulation No. 13, and USPS revision, we will have fully approved the 
Denver CO element of the SIP under section 110(k) of the CAA.
    (d) Redesignation Criterion: The Area Must Show That The 
Improvement In Air Quality Is Due To Permanent And Enforceable 
Emissions Reductions
    Section 107(d)(3)(E)(iii) of the CAA provides that for an area to 
be redesignated to attainment, the Administrator must determine that 
the improvement in air quality is due to permanent and enforceable 
reductions in emissions resulting from implementation of the applicable 
implementation plan, implementation of applicable Federal air pollutant 
control regulations, and other permanent and enforceable reductions.
    The Denver CO element of the Colorado SIP was adopted by the AQCC 
on June 16, 1994, and was approved by the EPA on March 10, 1997 (62 FR 
10690). The 1994 SIP element's emission control plan was primarily 
based on emission reductions from the Federal Motor Vehicle Control 
Program (FMVCP), Colorado's Automobile Inspection and Readjustment 
Program, Colorado's Oxygenated Gasoline Program, and Colorado's 
Residential Wood Burning Control Measures. The anticipated date for 
Denver to attain the 8-hour CO NAAQS was December 31, 2000. These 
programs are further described in Part II, Chapter 3, section D. of the 
maintenance plan.
    In general, the FMVCP provisions require vehicle manufacturers to 
meet more stringent vehicle emission limitations for new vehicles in 
future years. These emission limitations are phased in (as a percentage 
of new vehicles manufactured) over a period of years. As new, lower 
emitting vehicles replace older, higher emitting vehicles (``fleet 
turnover''), emission reductions are realized for a particular area 
such as Denver. For example, EPA promulgated lower hydrocarbon (HC) and 
CO exhaust emission standards in 1991, known as Tier I standards for 
new motor vehicles (light-duty vehicles and light-duty trucks) in 
response to the 1990 CAA amendments. These Tier I emissions standards 
were phased in with 40% of the 1994 model year fleet, 80% of the 1995 
model year fleet, and 100% of the 1996 model year fleet.
    As described in Part II, Chapter 3, section D. of the maintenance 
plan, significant additional emission reductions were realized from 
Denver's basic I/M program (applicable to 1981 and older vehicles) and, 
beginning in 1995, the enhanced I/M or I/M240 program (applicable to 
1982 and newer vehicles). Colorado's Regulation No. 11, ``Motor Vehicle 
Emissions Inspection Program'', contains a full description of the 
requirements for both of Denver's I/M programs.
    Oxygenated fuels are gasolines that are blended with additives that 
increase

[[Page 44101]]

the level of oxygen in the fuel and, consequently, reduce CO tailpipe 
emissions. Colorado's Regulation 13, ``Oxygenated Fuels Program'', 
contains the oxygenated fuels provisions for the Denver nonattainment 
area. As approved by EPA on August 25, 1999 (see 64 FR 46279), 
Regulation 13 required all Denver-area gas stations to sell fuels 
containing a 3.1% minimum oxygen content (by weight) during the 
wintertime CO high pollution maximum blending season. The use of 
oxygenated fuels contributed to the area's attainment of the CO NAAQS.
    Denver has also been implementing the requirements of Regulation 
No. 4 ``New Wood Stoves and the use of Certain Woodburning Appliances 
During High Pollution Days.'' The primary strategy of Regulation No. 4 
is the mandatory wood burning curtailment program that prohibits most 
wood burning activity on ``high pollution days'' between November 1st 
and March 31st of each year in the Denver metropolitan area. Regulation 
No. 4 also requires all new wood burning stoves and fireplace inserts 
sold in Colorado to meet both State and Federal emission control 
standards.
    We have evaluated the various State and Federal control measures, 
the original 1990 base year emission inventory, the original 2001 
attainment year emission inventory, and the 1993 and 1996 periodic 
emission inventories, and believe that the improvement in air quality 
in the Denver nonattainment area has resulted from emission reductions 
that are permanent and enforceable.
    (e) Redesignation Criterion: The Area Must Have A Fully Approved 
Maintenance Plan Under CAA Section 175A
    Section 107(d)(3)(E)(iv) of the CAA provides that for an area to be 
redesignated to attainment, the Administrator must have fully approved 
a maintenance plan for the area meeting the requirements of section 
175A of the CAA.
    Section 175A of the CAA sets forth the elements of a maintenance 
plan for areas seeking redesignation from nonattainment to attainment. 
The maintenance plan must demonstrate continued attainment of the 
applicable NAAQS for at least ten years after the Administrator 
approves a redesignation to attainment. Eight years after the 
promulgation of the redesignation, the State must submit a revised 
maintenance plan that demonstrates continued attainment for the 
subsequent ten-year period following the initial ten-year maintenance 
period. To address the possibility of future NAAQS violations, the 
maintenance plan must contain contingency measures, with a schedule for 
adoption and implementation, that are adequate to assure prompt 
correction of a violation. In addition, we issued further maintenance 
plan interpretations in the ``General Preamble for the Implementation 
of Title I of the Clean Air Act Amendments of 1990'' (57 FR 13498, 
April 16, 1992), ``General Preamble for the Implementation of Title I 
of the Clean Air Act Amendments of 1990; Supplemental'' (57 FR 18070, 
April 28, 1992), and the EPA guidance memorandum entitled ``Procedures 
for Processing Requests to Redesignate Areas to Attainment'' from John 
Calcagni, Director, Air Quality Management Division, Office of Air 
Quality and Planning Standards, to Regional Air Division Directors, 
dated September 4, 1992 (hereafter the September 4, 1992 Calcagni 
Memorandum). In this Federal Register action, EPA is proposing approval 
of the maintenance plan for the Denver CO nonattainment area because we 
believe, as detailed below, that the State's maintenance plan submittal 
meets the requirements of section 175A and is consistent with the 
documents referenced above. Our analysis of the pertinent maintenance 
plan requirements, with reference to the Governor's May 10, 2000, 
submittal, is provided as follows:

1. Emissions Inventories--Attainment Year and Projections

    EPA's interpretations of the CAA section 175A maintenance plan 
requirements are generally provided in the General Preamble (see 57 FR 
13498, April 16, 1992) and the September 4, 1992, Calcagni Memorandum 
referenced above. Under our interpretations, areas seeking to 
redesignate to attainment for CO may demonstrate future maintenance of 
the CO NAAQS either by showing that future CO emissions will be equal 
to or less than the attainment year emissions or by providing a 
modeling demonstration. However, under the CAA, many areas (such as 
Denver) were required to submit a modeled attainment demonstration to 
show that reductions in emissions would be sufficient to attain the 
applicable NAAQS. For these areas, the maintenance demonstration is to 
be based on the same level of modeling (see the September 4, 1992, 
Calcagni Memorandum). For the Denver area, this involved the use of 
EPA's Urban Airshed Model (UAM) in conjunction with intersection 
Hotspot modeling using the CAL3QHC model (see 62 FR 10690, March 10, 
1997).
    The maintenance plan that the Governor submitted on May 10, 2000, 
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. The State 
used the 2001 attainment year inventory, from the March 10, 1997, EPA-
approved attainment SIP (see 62 FR 10690) and included an interim-year 
projection for 2006 along with the final maintenance year of 2013. 
Additional mobile source emission inventories were provided for the 
years 2002, 2003, 2004, and 2005. These particular mobile source 
inventories present CO emissions during the phase-in period of the 
revisions to Regulation No. 11 for the Remote Sensing Device (RSD) 
program, the phase-in of more stringent cutpoints for the I/M240 
program, and the phase-down of the oxygenated gasoline program under 
the revisions to Regulation No. 13. More detailed descriptions of the 
2001 attainment year inventory from the approved nonattainment SIP for 
Denver, the 2006 projected inventory, the 2013 projected inventory, and 
the 2002, 2003, 2004, and 2005 mobile source projected inventories are 
documented in the maintenance plan in Part II, Chapter 4, section B, 
and in the State's TSD. The State's submittal contains detailed 
emission inventory information that was prepared in accordance with EPA 
guidance. Summary emission figures from the 2001 attainment year and 
the interim projected years are provided in Table III.-1 below.

                                            Table III-1.--Summary of CO Emissions in Tons Per Day for Denver
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                                                                   2001         2002         2003         2004         2005         2006         2013
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Point sources................................................         70.2  ...........  ...........  ...........  ...........         46.7         46.7
Area sources.................................................        198.2  ...........  ...........  ...........  ...........        172.8        172.6
Non-road mobile sources......................................         59.9  ...........  ...........  ...........  ...........         61.2         64.9
On-road mobile sources.......................................       *875.2         *851         *850         *827         *850       *844.7       *867.2
                                                              ------------------------------------------------------------------------------------------

[[Page 44102]]

 
    Total....................................................      *1203.3  ...........  ...........  ...........  ...........      *1125.4     *1151.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
*These figures represent CO emissions for the Denver CO modeling domain which is slightly larger than the Denver CO nonattainment area.

    We note in Table III-1 there are significant reductions projected 
in years 2006 and 2013 for point sources and area sources. The majority 
of the area source projected reductions are from the State's estimates 
for less woodburning in future years. We believe this projection of 
less woodburning is reasonable. For point sources, the original Denver 
CO nonattainment plan modeled all point sources at their potential-to-
emit (PTE) for 2001, and Table III-1 retains these values for 2001. For 
years 2006 and 2013, the State projected emissions for elevated point 
sources at PTE, but projected emissions from surface point sources 
based on actual emissions. This accounts for the reduction in emissions 
from point sources in 2006 and 2013. The State's approach follows EPA 
guidance on projected emissions and we believe it is acceptable.\2\ 
Further information on these projected emissions may also be found in 
Section 2 ``Emission Inventories'' of the State's TSD.
---------------------------------------------------------------------------

    \2\ ``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.
---------------------------------------------------------------------------

2. Demonstration of Maintenance

    The September 4, 1992, Calcagni Memorandum states that where 
modeling was relied on to demonstrate maintenance, the plan is to 
contain a summary of the air quality concentrations expected to result 
from the application of the control strategies. Also, the plan is to 
identify and describe the dispersion model or other air quality model 
used to project ambient concentrations.
    For the Denver CO redesignation maintenance demonstration, the 
State used the Urban Airshed dispersion Model (UAM) in conjunction with 
concentrations derived from the CAL3QHC intersection (or ``hotspot'') 
model. This was the same level of modeling as was used for the 1994 
Denver CO SIP attainment demonstration, which was approved by EPA on 
March 10, 1997 (62 FR 10690), and addressed the requirements of section 
187(a)(7) of the CAA. The UAM and CAL3QHC models were applied to the 
2006 and 2013 inventories using meteorological data from December 5, 
1988. This was the episode day used in the modeling in the EPA-approved 
1994 Denver CO nonattainment SIP revision and was thought to represent 
the worst-case meteorological conditions. For the CAL3QHC intersection 
component, six intersections were selected for modeling based on the 
latest information from Denver Regional Council Of Governments (DRCOG) 
regarding the highest volume and most congested intersections in the 
Denver CO nonattainment area. This was done consistent with our 
modeling guidance.
    After an analysis, the State concluded that the Continuous Air 
Monitoring Project (CAMP) ambient air quality monitor, located at the 
intersection of Broadway and Champa Street, was still the maximum 
concentration monitor for the Denver CO nonattainment area. This 
analysis is further detailed in Part II, Chapter 4, section C of the 
maintenance plan and in the State's TSD. We agree with the State's 
conclusion regarding the maximum concentration monitor. The results of 
the State's modeling for 2006 and 2013 are presented in Part II, 
Chapter 4, section C, of the maintenance plan, in the State's TSD, and 
are reproduced in Table III-2 below:

                       Table III-2.--Dispersion Modeling and Intersection Modeling Results
                                             [in parts per million]
----------------------------------------------------------------------------------------------------------------
                                                     2006                                   2013
           Intersection            -----------------------------------------------------------------------------
                                      UAM \1\    CAL3QHC \2\     Total         UAM        CAL3QHC       Total
----------------------------------------------------------------------------------------------------------------
Broadway & Champa \3\.............         7.59         1.12         8.71         7.88         1.08         8.96
Foothills & Arapahoe..............          0.9          4.8          5.7          0.9          4.7          5.6
1st & University..................          4.0          4.3          8.3          3.9          4.2          8.0
Hampden & University..............          1.9          3.6          5.5          1.9          4.3          6.2
Parker & Illiff...................          2.7          3.2          5.8          2.6          3.0          5.6
Arapahoe & University.............          1.3          3.6          5.0          1.3          3.9         5.3
----------------------------------------------------------------------------------------------------------------
\1\ UAM (Urban Airshed Model). This column represents the dispersion model's calculated background CO
  concentration at each location.
\2\ CAL3QHC (Intersection Model). This column represents the intersection model's calculated CO component
  concentration.
\3\ The use of two significant figures by the State for the Broadway and Champa intersection, where the CAMP
  monitor is located, reflects the fact that the modeling done for the maximum concentration location was more
  detailed.

    The modeling results presented in the Denver CO maintenance plan, 
the State's TSD, and as repeated in Table III-2 above show that CO 
concentrations are not estimated to exceed the 9.0 ppm 8-hour average 
CO NAAQS during the maintenance period's time frame through 2013. 
Therefore, we believe the Denver area has satisfactorily demonstrated 
maintenance of the CO NAAQS.

3. Monitoring Network and Verification of Continued Attainment

    Continued attainment of the CO NAAQS in the Denver area depends, in 
part, on the State's efforts to track indicators throughout the 
maintenance period. This requirement is met in two sections of the 
Denver CO maintenance plan. In Part II, Chapter 4, sections E and F.2, 
the State commits to continue the operation of the CO monitors in the 
Denver area and to annually review this

[[Page 44103]]

monitoring network and make changes as appropriate.
    Also, in Part II, Chapter 4, sections E and F.2, the State commits 
to track mobile sources' CO emissions (which are the largest component 
of the inventories) through the ongoing regional transportation 
planning process that is done by DRCOG. Since revisions to Denver's 
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 maintenance plan. 
This regional transportation process is conducted by DRCOG in 
coordination with the Denver Regional Air Quality Council (RAQC), the 
State's Air Pollution Control Division (APCD), the AQCC, and EPA.
    Based on the above, we are proposing approval of these commitments 
as satisfying the relevant requirements. We note that a final 
rulemaking approval will render the State's commitments federally 
enforceable.

4. 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 Part II, Chapter 4, section F of the maintenance plan, 
the contingency measures for the Denver area will be triggered by a 
violation of the CO NAAQS. (However, the maintenance plan does note 
that an exceedance of the CO NAAQS may initiate a voluntary, local 
process by the RAQC and APCD to identify and evaluate potential 
contingency measures.)
    The RAQC, 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 to the RAQC within 120 days of notification and the 
RAQC will present recommended contingency measures to the AQCC within 
180 days of notification. The AQCC will then hold a public hearing to 
consider the contingency measures recommended by the RAQC, 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 Part II, 
Chapter 4, section F of the Denver CO maintenance plan include; (1) a 
3.1% oxygenated fuels program from November 8th through February 7th, 
with a 2.0% oxygen content required from November 1st through November 
7th, (2) reinstatement of the enhanced I/M program in effect before 
January 10, 2000, and (3) Transportation Control Measures (TCM) such as 
financial incentives for Ecopass, Auraria transit pass, and improved 
traffic signalization. A more complete description of the triggering 
mechanism and these contingency measures can be found in Part II, 
Chapter 4, section F of the maintenance plan.
    Based on the above, we find that the contingency measures provided 
in the State's Denver CO maintenance plan are sufficient and meet the 
requirements of section 175A(d) of the CAA.

5. Subsequent Maintenance Plan Revisions

    In accordance with section 175A(b) of the CAA, Colorado has 
committed to submit a revised maintenance plan eight years after our 
approval of the redesignation. This provision for revising the 
maintenance plan is contained in Part II, Chapter 4, section G of the 
Denver CO maintenance plan.

IV. EPA's Evaluation of the Transportation Conformity Requirements

    One key provision of our conformity regulation requires a 
demonstration that emissions from the transportation plan and 
Transportation Improvement Program are consistent with the emissions 
budget(s) in the SIP (40 CFR sections 93.118 and 93.124). The emissions 
budget is 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 62193-96) and in the sections of the rule referenced above.
    The maintenance plan defines the CO motor vehicle emissions budget 
in the Denver CO attainment/maintenance area as 800 tons per day for 
all years 2002 and beyond. This budget is equal to the maintenance year 
(2013) mobile source emissions inventory for CO for the attainment/
maintenance area. We have scaled the modeling domain emissions 
projections for 2002 to the attainment/maintenance area values and 
believe the 800 tons per day value is essentially equivalent to the 
mobile source inventory for the attainment/maintenance area in 2002. In 
addition, our analysis indicates that the 800 tons per day budget is 
consistent with maintenance of the CO NAAQS throughout the maintenance 
period. Therefore, we are proposing to approve the 800 tons per day CO 
emissions budget for the Denver area.
    Pursuant to section 93.118(e)(4) of EPA's transportation conformity 
rule, as amended, EPA must determine the adequacy of submitted mobile 
source emissions budgets. EPA reviewed the Denver CO budget for 
adequacy using the criteria in 40 CFR 93.118(e)(4), and determined that 
the budget was adequate for conformity purposes. EPA's adequacy 
determination was made in a letter to the Colorado APCD on July 12, 
2000, and was announced in the Federal Register on August 3, 2000 (65 
FR 47726). As a result of this adequacy finding, the 800 ton per day 
budget took effect for conformity determinations in the Denver metro 
area on August 18, 2000. However, we are not bound by that 
determination in acting on the maintenance plan.

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

    Colorado's Regulation No. 11 is entitled ``Motor Vehicle Emissions 
Inspection Program'' (hereafter referred to as Regulation No. 11). In 
developing the Denver CO maintenance plan, the RAQC and State evaluated 
a number of options for revising the current motor vehicle emissions 
inspection programs. A description of the RAQC and State's process for 
the evaluation of potential options for Regulation No. 11 is found in 
Part I, Chapter 2 of the Governor's submittal. We note that Part I, 
Chapter 2 is only for informational purposes and was not submitted as a 
revision to the SIP. Part II, Chapter 4, is the maintenance plan that 
we are proposing to approve and it reflects the AQCC-adopted revisions, 
as an amendment to the SIP, to Regulation No. 11. These revisions to 
Regulation No. 11 were submitted, as a revision to the SIP, for our 
approval in conjunction with the maintenance plan and appear as 
Appendix A to the plan.
    We note that the Governor submitted several other revisions to 
Regulation No. 11 prior to or at the same time as the revision that he 
submitted with the Denver CO redesignation request and maintenance 
plan. These other revisions to Regulation No. 11, that we never

[[Page 44104]]

approved, were submitted on September 16, 1997, August 19, 1998, 
November 5, 1999, and May 10, 2000 (for Larimer and Weld Counties, 
Colorado). The version of Regulation No. 11 that was adopted on January 
10, 2000, became effective on March 1, 2000, and was submitted by the 
Governor in conjunction with the Denver CO redesignation request and 
maintenance plan supersedes and replaces the other revisions of 
Regulation No. 11.
    Current programs: Since 1995, the Denver metropolitan area has 
operated an Enhanced Inspection/Maintenance (I/M) program, also 
referred to as the I/M240 program, that includes a biennial test for 
vehicles manufactured 1982 and later; new vehicles are exempted from 
the test for their first four years. The Denver area also operates an 
annual, idle test for model year 1981 and older vehicles. Both the I/
M240 and idle test stations are required to be ``test-only'' 
facilities, meaning that they are not permitted to perform repairs or 
sell automotive parts. The programs also include waiver provisions for 
hardship cases and for motorists who spend $450 on repairs. All 
vehicles in the Denver program area are required to be tested upon 
change of ownership.
    With the development of the Denver CO maintenance plan, the RAQC 
and State evaluated several options for revising Regulation No. 11 to 
reduce the cost of the I/M programs and improve motorist convenience 
without jeopardizing maintenance of the CO standard. In their 
evaluations, the RAQC and State retained four components of the current 
I/M programs: (1) A test-only requirement for both the I/M240 transient 
program and the idle test program, (2) the requirement for the idle 
test for 1981 and older vehicles, (3) the current waiver policies, and 
(4) the requirement for testing upon change of ownership. In addition, 
the testing exemption for the first 4 years for a new vehicle was also 
retained. The major change to Regulation No. 11 for the Denver CO 
maintenance plan involved the implementation of a remote sensing device 
(RSD), clean-screen program for the Denver area. Remote sensing 
technology takes an instantaneous measurement of a vehicle's emissions 
as it is driven on the road past an RSD equipment location. RSD 
technology essentially involves the use of a light beam emitting device 
and reflector. As a vehicle passes through the light beam, the 
emissions are instantly recorded. Vehicle data, correlated from the 
license plate and hence registration, is then compared with the 
particular vehicle's model year emission specifications as stated in 
Regulation No. 11. Vehicles identified as ``clean,'' would be exempt 
from one inspection cycle.
    Based on a Greeley, Colorado pilot study and an additional pilot 
study in Denver, conducted by the Colorado Department of Public Health 
and Environment (CDPHE), implementing remote emissions sensing 
technology as an alternative inspection procedure brings with it some 
losses in emissions reduction compared to traditional inspection 
procedures. Use of remote sensing for clean screening will typically 
reduce the credit ascribable to the I/M program because some vehicles 
with high tailpipe emissions may appear clean in a remote sensing test 
and will be excused from I/M tailpipe testing and repair for that I/M 
cycle. Also, remote sensing cannot identify low versus high emitting 
vehicles with respect to evaporative hydrocarbon emissions. The AQCC 
concluded that this loss of emissions reduction will have no negative 
impact on compliance with the NAAQS for the Larimer County, Weld 
County, and Denver metropolitan program areas.
    We are proposing to approve the implementation of a clean-screen 
program for Larimer County, Weld County, and metropolitan Denver in 
accordance with EPA's final rule, ``Additional Flexibility Amendments 
to Vehicle Inspection Maintenance Program Requirements, Amendment to 
the Final Rule,'' as published in the Federal Register on July 24, 2000 
(65 FR 45526), and EPA's Technical Highlights document, ``Clean 
Screening in Inspection and Maintenance Programs'' (EPA420-F-98-023).
    To implement the clean-screen program for metropolitan Denver 
(Adams County-part, Arapahoe County-part, Boulder County-part, Denver 
County, Douglas County, and Jefferson County), the State will develop a 
network of RSD sites to achieve the clean-screen program percentages 
described below.
    In order to show continued compliance with the CO NAAQS, the Denver 
RSD clean-screen program will be phased-in starting in 2002. The 
program is designed to evaluate 20% of the fleet in 2003, 40% of the 
fleet in 2004, 60% of the fleet in 2005, and 80% of the fleet in 2006. 
The RSD clean-screen program will continue through 2013. In conjunction 
with the new RSD clean-screen program, Regulation No. 11's I/M240 
program for Denver will also continue to apply to evaluate the 
remainder of the applicable fleet and those vehicles that did not pass 
the clean-screen evaluation by the RSD clean-screen program. Also, the 
I/M240 CO cutpoints will be tightened from the current levels of 20 
grams per mile (through 2005) to 10 grams per mile in 2006 through 
2013.
    As we discussed above, the emission reductions associated with the 
revisions to Regulation No. 11 were incorporated by the State into both 
the 2006 and 2013 UAM/CAL3QHC Denver modeling evaluations and 
maintenance of the CO NAAQS was successfully demonstrated.
    For the Larimer County (Fort Collins area) and Weld County (Greeley 
area) programs, we conducted our own analysis, based on State-provided 
data, of the potential impacts from the implementation of RSD in these 
areas. These remote sensing programs are designed to exempt 35% of the 
I/M eligible vehicles from a periodic emissions inspection, which is 
estimated to result in a 4% decrease in overall I/M benefit. This 
translates into an increase in CO emissions of 1.28 tons per day for 
the Fort Collins area (out of a total CO inventory of approximately 134 
tons per day) and an increase of 0.26 tons per day for the Greeley area 
(out of a total inventory of approximately 44 tons per day).
    We also reviewed CO ambient air quality data for both areas for the 
complete years of 1995, 1996, 1997, 1998, 1999, and 2000. For the Fort 
Collins area, the highest 8-hour CO value was 5.8 ppm with a six-year 
average of 5.3 ppm. For the Greeley area, the highest 8-hour CO value 
was 7.5 ppm with a six-year average of 5.3 ppm. Because the estimated 
emissions increases are minimal and the CO ambient monitored values are 
well below the standard (the 8-hour CO NAAQS is 9.0 ppm), we believe 
the revisions to Regulation No. 11 for Larimer and Weld Counties will 
not affect the ability of these areas to continue to show attainment of 
the CO NAAQS.
    We have reviewed, and are proposing approval of, these State-
adopted changes to Regulation No. 11.

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

    Colorado's Regulation No. 13 is entitled ``Oxygenated Fuels 
Program'' (hereafter referred to as Regulation No. 13). The purpose of 
this regulation is to reduce CO emissions from gasoline powered motor 
vehicles in the Denver area through the wintertime use of oxygenated 
gasolines. Section 211(m) of the CAA originally required the State to 
implement an oxygenated fuels program in the Denver Consolidated 
Metropolitan Statistical Area (CMSA). Section 211(m) states that the 
oxygenated fuels program must cover no less than a four month period 
each year

[[Page 44105]]

unless EPA approves a shorter period. We can approve a shorter 
implementation period if a State submits a demonstration that a reduced 
implementation period will still assure that there will be no 
exceedances of the CO NAAQS outside of this reduced period. This was 
done previously when we approved revisions to Regulation No. 13 for the 
Denver area that shortened the oxygenated fuels season and oxygenate 
content (see 62 FR 10690, March 10, 1997 and 64 FR 46279, August 25, 
1999). When an area is redesignated to attainment, the oxygenated fuels 
program may be further shortened or eliminated entirely as long as the 
State is able to show the program is not needed to demonstrate 
maintenance of the CO NAAQS (see 65 FR 80779, December 22, 2000).
    In developing the Denver CO maintenance plan, the RAQC and State 
evaluated a number of options for revising the current oxygenated 
gasoline program. A description of the RAQC and State's process for the 
evaluation of potential options for Regulation No. 13 is found in Part 
I, Chapter 2 of the Governor's submittal. We note that Part I, Chapter 
2 is only for informational purposes and was not submitted as a 
revision to the SIP. Part II, Chapter 4, is the maintenance plan that 
we are proposing to approve and it reflects the AQCC-adopted revisions, 
as an amendment to the SIP, to Regulation No. 13. These revisions to 
Regulation No. 13 were submitted for our approval in conjunction with 
the maintenance plan and appear as Appendix B to the plan.
    The current EPA-approved oxygenated gasoline program for the Denver 
area has the following four requirements: (1) The control period is 
from November 1st through February 7th of each winter season, (2) an 
oxygen content of at least 2.0% by weight is required from November 1st 
through November 7th, (3) an oxygen content of at least 2.7% by weight 
is required from November 8th through February 7th, with a requirement 
for maximum allowable oxygenate blending between November 8th and 
January 31st. The maximum blending for ethanol is 10% by volume (this 
provides a 3.5% by weight oxygen content), and (4) if the market does 
not achieve an average oxygenate content of 3.1% by weight for the area 
during the maximum blending period, a mandatory program to achieve 3.1% 
shall be implemented.
    With the submittal of the Denver CO maintenance plan, the State of 
Colorado is seeking EPA's approval of revisions to Regulation No. 13 
that would shorten the oxygenated fuels season and reduce the required 
oxygen content of the fuels. The specific revisions to Regulation No. 
13 adopted by the AQCC are presented in Table VI-1:

                    Table VI-1.--Regulation No. 13 Changes to the Oxygenated Gasoline Program
                              [All percentages represent oxygen content by weight]
----------------------------------------------------------------------------------------------------------------
                                                                    Nov. 1st to     Nov. 8th to     Feb. 1st to
                          Winter season                              Nov. 7th        Jan. 31st       Feb. 7th
----------------------------------------------------------------------------------------------------------------
2001-2002.......................................................            2.0%            2.7%            2.7%
2002-2003.......................................................            2.0%            2.6%            1.5%
2003-2004.......................................................            2.0%            2.0%            1.5%
2004-2005.......................................................            1.9%            1.9%            0.0%
2005-2006 up through 2011-20012.................................            1.5%            1.5%            0.0%
2012-2013.......................................................            1.7%            1.7%            0.0%
----------------------------------------------------------------------------------------------------------------

    As we discussed above, the emission reductions associated with the 
revisions to Regulation No. 13 were incorporated by the State into both 
the 2006 and 2013 UAM/CAL3QHC modeling evaluations and maintenance of 
the CO NAAQS was successfully demonstrated.
    We have reviewed, and are proposing to approve, these State-adopted 
changes to Regulation No. 13 as demonstrating maintenance of the CO 
NAAQS and as meeting the requirements of section 211(m) of the CAA.

VII. EPA's Evaluation of the USPS Revision

    Section 246(a)(2)(B) of the CAA requires areas, such as the Denver 
CO nonattainment area, to have a clean fuel vehicle program in the EPA-
approved SIP. Although the State submitted various revisions to 
Colorado's Regulation No. 17 over the years to try to meet the 
requirements of section 246(a)(2)(B) (Governor's submittals dated 
October 17, 1994, August 20, 1996, and September 16, 1997), we never 
acted favorably on any of these revisions because they either did not 
meet the requirements of the CAA or the State withdrew the authority 
for Regulation No. 17.
    We advised the State that we would be unable to redesignate the 
Denver area to attainment for CO unless the Governor submitted a clean 
fuel vehicle program meeting the requirements of section 246(a)(2)(B) 
of the CAA or a substitute program pursuant to CAA section 
182(c)(4).\3\ The State has chosen to submit a substitute program.
---------------------------------------------------------------------------

    \3\ Section 182(c)(4)(B) of the CAA refers to ozone-producing 
emissions; however, EPA has interpreted this section to allow for 
substitute programs for CO as well.
---------------------------------------------------------------------------

    On May 22, 2000, the State, EPA, and USPS entered into an agreement 
under EPA's Project eXcellence and Leadership program (Project XL) and 
Colorado's Environmental Leadership Program under which the USPS agreed 
to destroy or relocate several hundred pre-1984 high-emitting postal 
delivery vehicles and replace them with low-emitting vehicles (LEV \4\) 
and low-emitting flexible fuel vehicles.\5\ As part of this agreement, 
the USPS agreed that the State could incorporate the major components 
of the agreement into a SIP revision that the State could use as a 
substitute for a clean fuel vehicle program.
---------------------------------------------------------------------------

    \4\ A LEV is any vehicle certified to the low emission vehicle 
standards specified in 40 CFR 86, subpart R.
    \5\ A flexible fuel vehicle or dual fuel vehicle is a vehicle 
which operates on the combination of gasoline and an alternative 
fuel (any fuel other than gasoline and diesel fuel, such as 
methanol, ethanol, and gaseous fuels (40 CFR 86.000-2)), such as E-
85 (gasoline blended with 85% ethanol).
---------------------------------------------------------------------------

    The AQCC adopted the USPS revision on March 16, 2000, and the 
revision became State-effective on May 30, 2000. The Governor submitted 
the USPS SIP revision to us on May 7, 2001.
    On May 30, 2001, the Colorado Attorney General's Office submitted 
administrative corrections to the USPS SIP revision \6\ and we are 
acting on the corrected version of the SIP revision.

[[Page 44106]]

Our approval of the USPS revision is necessary in order for the State 
to meet the redesignation requirements of section 107(d)(3)(E)(v) of 
the CAA.
---------------------------------------------------------------------------

    \6\ Following adoption of the USPS revision, the AQCC 
inadvertently neglected to put the revision in final form before 
sending it to the Governor's office for submitted to EPA. In 
correcting the USPS revision, State Staff merely removed headings 
that indicated the USPS revision was ``draft'', dated and titled the 
revision, and inserted the correct date for the USPS Project XL 
agreement.
---------------------------------------------------------------------------

    We are proposing approval of the USPS SIP revision because we have 
performed an emissions reduction analysis (included with the docket for 
this action) and have determined that the State will achieve greater 
reductions in emissions of CO with the USPS revision than would have 
been achieved by the clean fuels vehicle program required by CAA 
section 246(a)(2)(B).

VIII. Proposed Rulemaking Action and Request for Public Comment

    We are soliciting public comment on all aspects of this proposed 
SIP rulemaking action. As stated above, we are proposing approval of 
the Governor's May 10, 2000, request to redesignate the Denver carbon 
monoxide nonattainment area to attainment, the maintenance plan, the 
revisions to Regulation No. 11, the revisions to Regulation No. 13, and 
the USPS revision. Send your comments in duplicate to the address 
listed at the front of this proposed rule. We will consider your 
comments in deciding our final action if your letter is received before 
September 21, 2001.

Administrative Requirements

(a) Executive Order 12866
    The Office of Management and Budget (OMB) has exempted this 
regulatory action from Executive Order 12866, entitled ``Regulatory 
Planning and Review.''
(b) Executive Order 13045
    Protection of Children from Environmental Health Risks and Safety 
Risks (62 FR 19885, April 23, 1997), applies to any rule that: (1) Is 
determined to be ``economically significant'' as defined under 
Executive Order 12866, and (2) concerns an environmental health or 
safety risk that EPA has reason to believe may have a disproportionate 
effect on children. If the regulatory action meets both criteria, the 
Agency must evaluate the environmental health or safety effects of the 
planned rule on children, and explain why the planned regulation is 
preferable to other potentially effective and reasonably feasible 
alternatives considered by the Agency.
    This rule is not subject to Executive Order 13045 because it does 
not involve decisions intended to mitigate environmental health or 
safety risks.
(c) Executive Order 13132
    Federalism (64 FR 43255, August 10, 1999) revokes and replaces 
Executive Orders 12612 (Federalism) and 12875 (Enhancing the 
Intergovernmental Partnership). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive Order to include regulations 
that 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.'' Under Executive Order 13132, EPA may not issue a 
regulation that has federalism implications, that imposes substantial 
direct compliance costs, and that is not required by statute, unless 
the Federal government provides the funds necessary to pay the direct 
compliance costs incurred by State and local governments, or EPA 
consults with State and local officials early in the process of 
developing the proposed regulation. EPA also may not issue a regulation 
that has federalism implications and that preempts State law unless the 
Agency consults with State and local officials early in the process of 
developing the proposed regulation.
    This rule will 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, because it 
merely proposes approval of 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. In 
addition, redesignation of an area to attainment under sections 
107(d)(3)(D) and (E) of the Clean Air Act does not impose any new 
requirements. Thus, the requirements of section 6 of the Executive 
Order do not apply to this rule.
(d) Executive Order 13175
    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 6, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' ``Policies that have tribal 
implications'' is defined in the Executive Order to include regulations 
that have ``substantial direct effects on one or more Indian tribes, on 
the relationship between the Federal government and the Indian tribes, 
or on the distribution of power and responsibilities between the 
Federal government and Indian tribes.''
    This proposed rule does not have tribal implications. It will not 
have substantial direct effects on tribal governments, 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 in Executive Order 13175. 
This action does not involve or impose any requirements that affect 
Indian Tribes. Thus, Executive Order 13175 does not apply to this 
proposed rule.
(e) Executive Order 13211 (Energy Effects)
    This rule is not subject to Executive Order 13211 ``Actions 
Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use'' (66 FR 28355 (May 22, 2001)) because it is not a 
significant regulatory action under Executive Order 12866.
(f) Regulatory Flexibility
    The Regulatory Flexibility Act (RFA) generally requires an agency 
to conduct a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements unless the agency certifies 
that the rule will not have a significant economic impact on a 
substantial number of small entities. Small entities include small 
businesses, small not-for-profit enterprises, and small governmental 
jurisdictions.
    This proposed approval will not have a significant impact on a 
substantial number of small entities because SIP approvals under 
section 110 and subchapter I, part D of the Clean Air Act do not create 
any new requirements, but simply approve requirements that the State is 
already imposing. Therefore, because a Federal SIP approval does not 
create any new requirements, I certify that this action will not have a 
significant economic impact on a substantial number of small entities. 
Moreover, due to the nature of the Federal-State relationship under the 
Clean Air Act, preparation of flexibility analysis would constitute 
Federal inquiry into the economic reasonableness of state action. The 
Clean Air Act forbids EPA to base its actions concerning SIPs on such 
grounds. Union Electric Co., v. U.S. EPA, 427 U.S. 246, 255-66 (1976); 
42 U.S.C. 7410(a)(2). Redesignation of an area to attainment under 
sections 107(d)(3)(D) and (E) of the Clean Air Act does not impose any 
new

[[Page 44107]]

requirements. Redesignation to attainment is an action that affects the 
legal designation of a geographical area and does not impose any 
regulatory requirements. Therefore, because the redesignation to 
attainment does not create any new requirements, I certify that the 
proposed approval of the redesignation request will not have a 
significant economic impact on a substantial number of small entities.
(g) Unfunded Mandates
    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
must prepare a budgetary impact statement to accompany any proposed or 
final rule that includes a Federal mandate that may result in estimated 
costs to State, local, or tribal governments in the aggregate; or to 
the private sector, of $100 million or more. Under section 205, EPA 
must select the most cost-effective and least burdensome alternative 
that achieves the objectives of the rule and is consistent with 
statutory requirements. Section 203 requires EPA to establish a plan 
for informing and advising any small governments that may be 
significantly or uniquely impacted by the rule.
    EPA has determined that the proposed approval does not include a 
Federal mandate that may result in estimated costs of $100 million or 
more to either State, local, or tribal governments in the aggregate, or 
to the private sector. This Federal action proposes approval of pre-
existing requirements under State or local law and of the State's 
redesignation request, and imposes no new requirements. Accordingly, no 
additional costs to State, local, or tribal governments, or to the 
private sector, result from this action.

List of Subjects

40 CFR Part 52

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

40 CFR Part 81

    Air pollution control, National parks, Wilderness areas.

    Dated: August 15, 2001.
Jack W. McGraw,
Acting Regional Administrator, Region VIII.
[FR Doc. 01-21197 Filed 8-22-01; 8:45 am]
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