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[Federal Register Volume 78, Number 230 (Friday, November 29, 2013)]
[Proposed Rules]
[Pages 71550-71554]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-28652]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2011-0833; FRL-9903-25-Region-8]

Approval and Promulgation of Air Quality Implementation Plans; 
State of Colorado Second Ten-Year PM10 Maintenance Plan for 
Telluride

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve State Implementation Plan (SIP) 
revisions submitted by the State of Colorado. On March 31, 2010, the 
Governor of Colorado's designee submitted to EPA a revised maintenance 
plan for the Telluride area for the 24-hour National Ambient Air 
Quality Standards (NAAQS) for particulate matter with an aerodynamic 
diameter less than or equal to 10 microns (PM10), which was 
adopted on November 19, 2009. As required by Clean Air Act (CAA) 
section 175A(b), this revised maintenance plan addresses maintenance of 
the PM10 standard for a second 10-year period beyond the 
area's original redesignation to attainment for the PM10 
NAAQS. In addition, EPA is proposing to approve the revised maintenance 
plan's 2021 transportation conformity motor vehicle emissions budget 
for PM10. Also, we are proposing to exclude from use in 
determining that Telluride continues to attain the PM10 
NAAQS exceedances of the PM10 NAAQS that were recorded at 
the Telluride PM10 monitor on April 5, 2010 and April 16, 
2013, because they meet the criteria for exceptional events caused by 
high wind natural events. This action is being taken under sections 110 
and 175A of the CAA.

DATES: Written comments must be received on or before December 30, 
2013.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2011-0833, by one of the following methods:
    http://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     Email: ostigaard.crystal@epa.gov.
     Fax: (303) 312-6064 (please alert the individual listed in 
the FOR FURTHER INFORMATION CONTACT if you are faxing comments).
     Mail: Carl Daly, Director, Air Program, U.S. Environmental 
Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop Street, 
Denver, Colorado 80202-1129.
     Hand Delivery: Carl Daly, Director, Air Program, U.S. 
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 
Wynkoop Street, Denver, Colorado 80202-1129. Such deliveries are only 
accepted Monday through Friday, 8:00 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-
2011-0833. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://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 email. 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 email comment directly to EPA, without 
going through http://www.regulations.gov, your email 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 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 Program, U.S. 
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 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, 8:00 a.m. 
to 4:00 p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Crystal Ostigaard, Air Program, U.S. 
Environmental Protection Agency, Region 8, Mailcode 8P-AR, 1595 Wynkoop 
Street, Denver, Colorado 80202-1129, (303) 312-6602, 
ostigaard.crystal@epa.gov.

SUPPLEMENTARY INFORMATION:

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 initials APCD mean or refer to the Colorado Air Pollution 
Control Division.
    (iii) The initials AQCC mean or refer to the Colorado Air Quality 
Control Commission.
    (iv) The initials AQS mean or refer to the EPA Air Quality System 
database.
    (v) The words Colorado and State mean or refer to the State of 
Colorado.
    (vi) The initials CDOT mean or refer to the Colorado Department of 
Transportation.
    (vii) The initials CDPHE mean or refer to the Colorado Department 
of Public Health and Environment.
    (viii) The words EPA, we, us or our mean or refer to the United 
States Environmental Protection Agency.

[[Page 71551]]

    (ix) The initials MVEB mean or refer to motor vehicle emissions 
budget.
    (x) The initials NAAQS mean or refer to National Ambient Air 
Quality Standard.
    (xi) The initials PM10 mean or refer to particulate 
matter with an aerodynamic diameter of less than or equal to 10 
micrometers (coarse particulate matter).
    (xii) The initials RTP mean or refer to the Regional Transportation 
Plan.
    (xiii) The initials SIP mean or refer to State Implementation Plan.
    (xiv) The initials TIP mean or refer to the Transportation 
Improvement Program.
    (xv) The initials TSD mean or refer to technical support document.

Table of Contents

I. General Information
II. Background
III. What was the State's process?
IV. EPA's Evaluation of the Revised Telluride PM10 
Maintenance Plan
V. Proposed Action
VI. Statutory and Executive Orders Review

I. General Information

    1. Submitting CBI. Do not submit CBI to EPA through http://www.regulations.gov or email. 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. Background

    The Telluride area was designated nonattainment for PM10 
and classified as moderate by operation of law upon enactment of the 
CAA Amendments of 1990. See 56 FR 56694, 56705, 56736 (November 6, 
1991). EPA partially/conditionally approved Colorado's nonattainment 
area SIP for the Telluride PM10 nonattainment area on 
September 19, 1994 (59 FR 47807) and fully approved the SIP on October 
4, 1996 (61 FR 51784). On May 10, 2000, the Governor of Colorado 
submitted a request to EPA to redesignate the Telluride moderate 
PM10 nonattainment area to attainment for the 1987 24-hour 
PM10 NAAQS. Along with this request, the State submitted a 
maintenance plan, which demonstrated that the area was expected to 
remain in attainment of the 24-hour PM10 NAAQS through 2012. 
EPA approved the Telluride maintenance plan and redesignation to 
attainment on June 15, 2001 (66 FR 32556).
    Eight years after an area is redesignated to attainment, CAA 
section 175A(b) requires the state to submit a subsequent maintenance 
plan to EPA, covering a second 10-year period.\1\ This second 10-year 
maintenance plan must demonstrate continued maintenance of the 
applicable NAAQS during this second 10-year period. To fulfill this 
requirement of the Act, the Governor of Colorado's designee submitted 
the second 10-year update of the PM10 maintenance plan to 
EPA on March 31, 2010 (hereafter; ``revised Telluride PM10 
Maintenance Plan'').
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    \1\ In this case, the initial maintenance period described in 
CAA section 175A(a) was required to extend for at least 10 years 
after the redesignation to attainment, which was effective on August 
14, 2001. See 66 FR 32556. So the first maintenance plan was 
required to show maintenance at least through 2011. CAA section 
175A(b) requires that the second 10-year maintenance plan maintain 
the NAAQS for ``10 years after the expiration of the 10-year period 
referred to in [section 175A(a)].'' Thus, for the Telluride area, 
the second 10-year period ends in 2021.
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    As described in 40 CFR 50.6, the level of the national primary and 
secondary 24-hour ambient air quality standards for PM10 is 
150 micrograms per cubic meter ([mu]g/m\3\). An area attains the 24-
hour PM10 standard when the expected number of days per 
calendar year with a 24-hour concentration in excess of the standard 
(referred to herein as ``exceedance''), as determined in accordance 
with 40 CFR part 50, appendix K, is equal to or less than one, averaged 
over a three-year period.\2\ See 40 CFR 50.6 and 40 CFR part 50, 
appendix K.
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    \2\ An exceedance is defined as a daily value that is above the 
level of the 24-hour standard, 150 [micro]g/m\3\, after rounding to 
the nearest 10 [micro]g/m\3\ (i.e., values ending in five or greater 
are to be rounded up). Thus, a recorded value of 154 [micro]g/m\3\ 
would not be an exceedance since it would be rounded to 150 
[micro]g/m\3\; whereas, a recorded value of 155 [micro]g/m\3\ would 
be an exceedance since it would be rounded to 160 [micro]g/m\3\. See 
40 CFR part 50, appendix K, section 1.0.
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    Table 1 below shows the maximum monitored 24-hour PM10 
values for the Telluride PM10 maintenance area for 2004 
through 2012, excluding one value that the State flagged as being 
caused by an exceptional event. The table reflects that the values for 
the Telluride area were well below the 24-hour PM10 NAAQS 
standard of 150 [mu]g/m\3\. However, on April 5, 2010, the area 
experienced an exceedance measured at 354 [mu]g/m\3\. The State flagged 
this value as a high wind exceptional event in EPA's Air Quality System 
(AQS), which is EPA's repository for ambient air quality data.
    40 CFR 50.1(j) defines an exceptional event as an event which 
affects air quality, is not reasonably controllable or preventable, is 
an event caused by human activity that is unlikely to recur at a 
particular location or a natural event, and is determined by the 
Administrator in accordance with 40 CFR 50.14 to be an exceptional 
event. Exceptional events do not include stagnation of air masses or 
meteorological inversions, meteorological events involving high 
temperatures or lack of precipitation, or air pollution relating to 
source noncompliance. 40 CFR 5.14(b) states that EPA shall exclude data 
from use in determinations of exceedances and NAAQS violations where a 
state demonstrates to EPA's satisfaction that an exceptional event 
caused a specific air pollution concentration in excess of one or more 
NAAQS at a particular air quality monitoring location and otherwise 
satisfies the requirements of section 50.14.
    The State submitted an exceptional event package on June 28, 2013 
requesting EPA's concurrence on the flag for the April 5, 2010 
exceedance. EPA completed its review of the exceptional events package 
for Telluride's 2010 exceedance and concurred on the flag on August 21,

[[Page 71552]]

2013 because the State successfully demonstrated that the exceedance on 
April 5, 2010 was caused by a natural high wind exceptional event due 
to blowing desert dust from upwind natural desert areas of Arizona, 
Utah, and southwest Colorado into the Telluride area.\3\ Thus, we are 
proposing to exclude from use in determining that Telluride continues 
to attain the 24- hour PM10 NAAQS the exceedance of the 24-
hour PM10 NAAQS that was recorded at the Telluride 
PM10 monitor on April 5, 2010. See 40 CFR 50.14(b) and 
(c)(2)(ii). With the exclusion of this data point, the highest value in 
2010 is 133 [mu]g/m\3\, which is well below the 24-hour PM10 
NAAQS standard.
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    \3\ Copies of the State's June 28, 2013 exceptional events 
package and our concurrence documents are included in the docket for 
this action.
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    Additionally, EPA reviewed 2013 data from AQS (this data has not 
yet been quality assured by Colorado) and found a high wind exceptional 
event of 265 [mu]g/m\3\ at the Telluride monitor on April 16, 2013. The 
State submitted the exceptional events package for this exceedance on 
October 3, 2013, and EPA concurred on the package on November 1, 2013, 
because the State successfully demonstrated that the exceedance on 
April 16, 2013 was caused by a natural high wind exceptional event 
blowing desert dust from upwind natural desert areas of Arizona, Utah, 
and southwest Colorado into the Telluride area.\4\ Thus, we are 
proposing to exclude from use in determining that Telluride continues 
to attain the 24-hour PM10 NAAQS the exceedance of the 24-
hour PM10 NAAQS that was recorded at the Telluride 
PM10 monitor on April 16, 2013.
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    \4\ Copies of the State's October 3, 2013 exceptional events 
package and our concurrence documents are included in the docket for 
this action.

             Table 1--Telluride PM10 Maximum 24-Hour Values
 [Based on Data from 333 West Colorado Avenue, AQS Identification Number
                              08-113-0004]
------------------------------------------------------------------------
                                                               Maximum
                                                                Value
                            Year                               ([mu]g/
                                                                m\3\)
------------------------------------------------------------------------
2004.......................................................           72
2005.......................................................           70
2006.......................................................           69
2007.......................................................           77
2008.......................................................           82
2009.......................................................          130
2010.......................................................          133
2011.......................................................           68
2012.......................................................           80
------------------------------------------------------------------------

    Table 2 below shows the estimated number of exceedances for the 
Telluride PM10 maintenance area for the three-year periods 
of 2004 through 2006, 2005 through 2007, 2006 through 2008, 2007 
through 2009, 2008 through 2010, 2009 through 2011, and 2010 through 
2012. To attain the standard, the three-year average number of expected 
exceedances (values greater than 150 [mu]g/m\3\) must be less than or 
equal to one. The table reflects continuous attainment of the 24-hour 
PM10 NAAQS.

              Table 2--Telluride PM10 Estimated Exceedances
 [Based on Data from 333 West Colorado Avenue, AQS Identification Number
                              08-113-0004]
------------------------------------------------------------------------
                                                              3-Year
                                                            estimated
                  Design value period                       number of
                                                           exceedances
------------------------------------------------------------------------
2004--2006.............................................                0
2005--2007.............................................                0
2006--2008.............................................                0
2007--2009.............................................                0
2008--2010.............................................                0
2009--2011.............................................                0
2010--2012.............................................                0
------------------------------------------------------------------------

III. What was the State's process?

    Section 110(a)(2) of the CAA requires that a state provide 
reasonable notice and public hearing before adopting a SIP revision and 
submitting it to EPA.
    The Colorado Air Quality Control Commission (AQCC) held a public 
hearing for the revised Telluride PM10 Maintenance Plan on 
November 19, 2009. The AQCC approved and adopted the revised Telluride 
PM10 Maintenance Plan during the hearing. The Governor's 
designee submitted the revised plan to EPA on March 31, 2010.
    We have evaluated the revised maintenance plan and have determined 
that the State met the requirements for reasonable public notice and 
public hearing under section 110(a)(2) of the CAA. On September 30, 
2010, by operation of law under CAA section 110(k)(1)(B), the revised 
maintenance plan was deemed to have met the minimum ``completeness'' 
criteria found in 40 CFR part 51, appendix V.

IV. EPA's Evaluation of the Revised Telluride PM10 
Maintenance Plan

    The following are the key elements of a Maintenance Plan for 
PM10: Emission Inventory, Maintenance Demonstration, 
Monitoring Network/Verification of Continued Attainment, Contingency 
Plan, and Transportation Conformity Requirements including the Motor 
Vehicle Emission Budget for PM10. Below, we describe our 
evaluation of these elements as they pertain to the revised Telluride 
PM10 Maintenance Plan.

A. Emission Inventory

    The revised Telluride PM10 Maintenance Plan includes 
three inventories of daily PM10 emissions for the Telluride 
area, for years 2007, 2015, and 2021. The Air Pollution Control 
Division (APCD) developed these emission inventories using EPA-approved 
emissions modeling methods and updated transportation and demographics 
data. Each emission inventory is a list, by source category, of the air 
contaminants directly emitted into the Telluride PM10 
maintenance area. A more detailed description of the 2007, 2015 and 
2021 inventories and information on model assumptions and parameters 
for each source category are contained in the State's PM10 
Maintenance Plan Technical Support Document (TSD). Included in both 
inventories are agriculture, highway vehicle exhaust, railroads, road 
dust, commercial cooking, construction, fuel combustion, non-road 
sources, structure fires, and woodburning. We find that Colorado has 
prepared adequate emission inventories for the area.

B. Maintenance Demonstration

    The revised Telluride PM10 Maintenance Plan uses 
emission roll-forward modeling to demonstrate maintenance of the 24-
hour PM10 NAAQS through 2021. Using the 2007 and 2021 
emissions inventories, the State first determined the projected growth 
in PM10 emissions from the 2007 base year to the 2021 
maintenance year. The State estimated that emissions would increase 
from 1,285 pounds per day in 2007 to 1,989 pounds per day in 2021. This 
represents an increase of 54.8 percent.
    The State then applied this percentage increase to the design day 
concentration of 82 [mu]g/m\3\, which was the highest 24-hour maximum 
PM10 value recorded in the Telluride area from 2006-2008. 
This resulted in an estimated maximum 24-hour PM10 
concentration in 2021 of 126.9 [mu]g/m\3\. This is well below the 24-
hour PM10 NAAQS of 150 [mu]g/m\3\.

C. Monitoring Network/Verification of Continued Attainment

    In the revised Telluride PM10 Maintenance Plan, the 
State commits to continue to operate an air quality monitoring network 
in accordance with 40 CFR part 58 to verify continued attainment of the 
24-hour PM10 NAAQS. This includes the continued operation of 
a PM10 monitor in the Telluride area, which the State will 
rely on to track PM10 emissions in the maintenance

[[Page 71553]]

area. The State also commits to conduct an annual review of the air 
quality surveillance system in accordance with 40 CFR 58.20(d) to 
determine whether the system continues to meet the monitoring 
objectives presented in Appendix D of 40 CFR part 58. Additionally, the 
State commits to track and document PM10 mobile source 
parameters and new and modified stationary source permits. If these and 
the resulting emissions change significantly over time, the APCD will 
perform appropriate studies to determine: (1) whether additional and/or 
re-sited monitors are necessary; and (2) whether mobile and stationary 
source emissions projections are on target.
    Based on the above, we are proposing approval of these commitments 
as satisfying the relevant requirements.

D. Contingency Plan

    Section 175A(d) of the CAA requires that a maintenance plan include 
contingency provisions to promptly correct any violation of the NAAQS 
that occurs after redesignation of an area. 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 the revised Telluride PM10 Maintenance 
Plan, the contingency measures will be triggered by a violation of the 
24-hour PM10 NAAQS. However, the maintenance plan notes that 
an exceedance of the 24-hour PM10 NAAQS may initiate a 
voluntary, local process by the Town of Telluride, the Town of Mountain 
Village, San Miguel County and the APCD to identify and evaluate 
potential contingency measures.
    The Town of Telluride, the Town of Mountain Village and San Miguel 
County in coordination with the APCD, AQCC, and the Colorado Department 
of Transportation (CDOT) will initiate a process to begin evaluating 
potential contingency measures no more than 60 days after notification 
from APCD that a violation of the 24-hour PM10 NAAQS has 
occurred. The AQCC will then hold a public hearing to consider the 
contingency measures recommended by the Town of Telluride, the Town of 
Mountain Village, San Miguel County, APCD and CDOT along with any other 
contingency measures the AQCC determines may be appropriate to 
effectively address the violation. The State commits to adopt and 
implement any necessary contingency measures within one year after a 
violation occurs.
    The State identifies the following as potential contingency 
measures in the revised Telluride PM10 maintenance plan: (1) 
Increased street sweeping requirements; (2) expanded, mandatory use of 
alternative de-icers; (3) more stringent street sand specifications; 
(4) road paving requirements; (5) woodburning restrictions; (6) re-
establishing new source review permitting requirements for stationary 
sources; and (7) other emission control measures appropriate for the 
area based on consideration of cost effectiveness, PM10 
emission reduction potential, economic and social considerations, or 
other factors.
    We find that the contingency measures provided in the revised 
Telluride PM10 Maintenance Plan are sufficient and meet the 
requirements of section 175A(d) of the CAA.

E. Transportation Conformity Requirements: Motor Vehicle Emission 
Budget for PM10

    Transportation conformity is required by section 176(c) of the CAA. 
EPA's conformity rule at 40 CFR part 93 requires that transportation 
plans, programs, and projects conform to SIPs and establishes the 
criteria and procedures for determining whether or not they conform. 
Conformity to a SIP means that transportation activities will not 
produce new air quality violations, worsen existing violations, or 
delay timely attainment of the NAAQS. To effectuate its purpose, the 
conformity rule requires a demonstration that emissions from the 
Regional Transportation Plan (RTP) and the Transportation Improvement 
Program (TIP) are consistent with the motor vehicle emissions budget(s) 
(MVEB(s)) contained in a control strategy SIP revision or maintenance 
plan (40 CFR 93.101, 93.118, and 93.124). A MVEB is defined as the 
level of mobile source emissions of a pollutant relied upon in the 
attainment or maintenance demonstration to attain or maintain 
compliance with the NAAQS in the nonattainment or maintenance area. 
Further information concerning EPA's interpretations regarding MVEBs 
can be found in the preamble to EPA's November 24, 1993, transportation 
conformity rule (see 58 FR 62193--62196).
    The revised Telluride PM10 Maintenance Plan contains a 
single MVEB of 1,108 lbs/day of PM10 for the year 2021, the 
maintenance year. Once the State submitted the revised plan with the 
2021 MVEB to EPA for approval, 40 CFR 93.118 required that EPA 
determine whether the MVEB was adequate.
    Our criteria for determining whether a SIP's MVEB is adequate for 
conformity purposes are outlined in 40 CFR 93.118(e)(4), which was 
promulgated August 15, 1997 (see 62 FR 43780). Our process for 
determining adequacy is described in our July 1, 2004 Transportation 
Conformity Rule Amendments (see 69 FR 40004) and in relevant 
guidance.\5\ We used these resources in making our adequacy 
determination described below.
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    \5\ ``Companion Guidance for the July 1, 2004 Final 
Transportation Conformity Rule, Conformity Implementation in Multi-
Jurisdictional Nonattainment and Maintenance Areas for Existing and 
New Air Quality Standards'' (EPA 420-B-04-012 July, 2004).
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    On November 22, 2010, EPA announced the availability of the revised 
Telluride PM10 Maintenance Plan, and the PM10 
MVEB, on EPA's transportation conformity adequacy Web site. EPA 
solicited public comment on the MVEB, and the public comment period 
closed on December 22, 2010. We did not receive any comments. This 
information is available at EPA's conformity Web site: http://www.epa.gov/otaq/stateresources/transconf/currsips.htm#telluride.
    By letter to the Colorado Department of Public Health and 
Environment (CDPHE) dated March 21, 2011, EPA found that the revised 
Telluride PM10 Maintenance Plan and the 2021 PM10 
MVEB were adequate for transportation conformity purposes.\6\ However, 
we noted in our letter that the revised Telluride PM10 
Maintenance Plan did not discuss the PM10 MVEB for 2012 of 
10,001 lbs/day from the original PM10 maintenance plan that 
EPA approved in 2001 (see 66 FR 32556, June 15, 2001).
---------------------------------------------------------------------------

    \6\ In a Federal Register notice dated August 2, 2011, we 
notified the public of our finding (see 76 FR 46288). This adequacy 
determination became effective on August 17, 2011.
---------------------------------------------------------------------------

    According to 40 CFR 93.118(e)(1), the EPA-approved 2012 
PM10 MVEB must continue to be used for analysis years 2012 
through 2020 (as long as such years are within the timeframe of the 
transportation plan), unless the State elects to submit a SIP revision 
to revise the 2012 PM10 MVEB and EPA approves the SIP 
revision. This is because the revised Telluride PM10 
Maintenance Plan did not revise the previously-approved 2012 
PM10 MVEB nor establish a new MVEB for 2012. Accordingly, 
the MVEB ``. . . for the most recent prior year . . .'' (i.e., 2012) 
from the original maintenance plan must continue to be used (see 40 CFR 
93.118(b)(1)(ii) and (b)(2)(iv)).
    We note that there is a considerable difference between the 2021 
and 2012 budgets--1,108 lbs/day versus 10,001 lbs/day. This is largely 
an artifact of changes in the methods, models, and

[[Page 71554]]

emission factors used to estimate mobile source emissions. The 2021 
MVEB is consistent with the State's 2021 emissions inventory for 
vehicle exhaust and road dust, and, thus, is consistent with the 
State's maintenance demonstration for 2021.
    The discrepancy between the 2012 and 2021 MVEBs is not a 
significant issue for several reasons. As a practical matter, the 2021 
MVEB of 1,108 lbs/day of PM10 would be controlling for any 
conformity determination involving the relevant years because 
conformity would have to be shown to both the 2012 MVEB and the 2021 
MVEB. Also, for any maintenance plan, like the revised Telluride 
PM10 Maintenance Plan, that only establishes a MVEB for the 
last year of the maintenance plan, 40 CFR 93.118(b)(2)(i) requires that 
the demonstration of consistency with the budget be accompanied by a 
qualitative finding that there are no factors that would cause or 
contribute to a new violation or exacerbate an existing violation in 
the years before the last year of the maintenance plan. Therefore, when 
a conformity determination is prepared which assesses conformity for 
the years before 2021, the 2021 MVEB and the underlying assumptions 
supporting it would have to be considered. Finally, 40 CFR 93.110 
requires the use of the latest planning assumptions in conformity 
determinations. Thus, the most current motor vehicle and road dust 
emission factors would need to be used, and we expect the analysis 
would show greatly reduced PM10 motor vehicle and road dust 
emissions from those calculated in the first maintenance plan. In view 
of the above, EPA is proposing to approve the 2021 PM10 MVEB 
of 1,108 lbs/day.

V. Proposed Action

    We are proposing to approve the revised Telluride PM10 
Maintenance Plan that was submitted to us on March 31, 2010. We are 
proposing to approve the revised maintenance plan because it 
demonstrates maintenance through 2021 as required by CAA section 
175A(b), retains the control measures from the initial PM10 
maintenance plan that EPA approved in June of 2001, and meets other CAA 
requirements for a section 175A maintenance plan. We are proposing to 
exclude from use in determining that Telluride continues to attain the 
24-hour PM10 NAAQS exceedances of the 24-hour 
PM10 NAAQS that were recorded at the Telluride 
PM10 monitor on April 5, 2010 and April 16, 2013 because 
they meet the criteria for exceptional events caused by high wind 
natural events. We are also proposing to approve the revised 
maintenance plan's 2021 transportation conformity MVEB for 
PM10 of 1,108 lbs/day.

VI. Statutory and Executive Orders Review

    Under the Clean Air Act, the Administrator is required to approve a 
SIP submission that complies with the provisions of the Act and 
applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). 
Thus, in reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. 
This proposed action merely proposes to approve state law as meeting 
Federal requirements and does not propose to impose additional 
requirements beyond those imposed by state law. For that reason, this 
proposed action:
     is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Order 
12866 (58 FR 51735, October 4, 1993);
     does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     does not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the Clean Air Act; and
     does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, this proposed action does not have tribal implications 
as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), 
because the SIP would not be approved to apply in Indian country 
located in the state, and EPA notes that it will not impose substantial 
direct costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, PM10, 
Incorporation by reference, Intergovernmental relations, Particulate 
matter, Reporting and recordkeeping requirements.

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

    Dated: November 18, 2013.
Howard M. Cantor,
Acting Regional Administrator, Region 8.
[FR Doc. 2013-28652 Filed 11-27-13; 8:45 am]
BILLING CODE 6560-50-P
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