Approval and Promulgation of State Implementation Plans; State of Colorado Regulation Number 3: Revisions to the Air Pollutant Emission Notice Requirements and Exemptions, 4271-4276 [2011-1477]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 76, Number 16 (Tuesday, January 25, 2011)]
[Proposed Rules]
[Pages 4271-4276]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-1477]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2007-0649; FRL-9256-5]


Approval and Promulgation of State Implementation Plans; State of 
Colorado Regulation Number 3: Revisions to the Air Pollutant Emission 
Notice Requirements and Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing partial approval and partial disapproval of 
State Implementation Plan (SIP) revisions regarding the Air Pollutant 
Emission Notice (APEN) regulations submitted by the State of Colorado 
on September 16, 1997, June 20, 2003, July 11, 2005, August 8, 2006 and 
August 1, 2007. The APEN provisions in Sections II.A. through II.D., 
Part A of Colorado's Regulation Number 3, specify the APEN filing 
requirements for stationary sources and exemptions from such 
requirements. This action is being taken under section 110 of the Clean 
Air Act (CAA).

DATES: Comments must be received on or before February 24, 2011.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2007-0649, by one of the following methods:
     https://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     E-mail: freeman.crystal@epa.gov.
     Fax: (303) 312-6064 (please alert the individual listed in 
the FOR FURTHER INFORMATION CONTACT if you are faxing comments).
     Mail: Callie Videtich, Director, Air Program, 
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 
Wynkoop Street, Denver, Colorado 80202-1129.
     Hand Delivery: Callie Videtich, Director, Air Program, 
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 
Wynkoop, Denver, Colorado 80202-1129. Such deliveries are only accepted 
Monday through Friday, 8 a.m. to 4:30 p.m., excluding Federal holidays. 
Special arrangements should be made for deliveries of boxed 
information.
    Instructions: Direct your comments to Docket ID No. EPA-R08-OAR-
2007-0649. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
https://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 https://www.regulations.gov or e-mail. The https://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA, without 
going through https://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional 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 https://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 https://www.regulations.gov or in hard copy at the Air Program, 
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 
Wynkoop, Denver, Colorado 80202-1129. EPA requests that if at all 
possible, you contact the individual listed in the FOR FURTHER 
INFORMATION CONTACT section to view the hard copy of the docket. You 
may view the hard copy of the docket Monday through Friday, 8 a.m. to 4 
p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Crystal Freeman, Air Program, U.S. 
Environmental Protection Agency, Region 8, Mailcode 8P-AR, 1595 
Wynkoop, Denver, Colorado 80202-1129, (303) 312-6602, 
freeman.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 words EPA, we, us or our mean or refer to the United 
States Environmental Protection Agency.
    (iii) The initials SIP mean or refer to State Implementation Plan.

[[Page 4272]]

    (iv) The words Colorado and State mean the State of Colorado.

Table of Contents

I. General Information
II. Background
III. What action is EPA proposing?
IV. What is the State process to submit these materials to EPA?
V. EPA's Review and Technical Information
VI. Proposed Action
VII. Statutory and Executive Order Reviews

I. General Information

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

II. Background

    The Colorado APEN provisions in Regulation Number 3, Part A, 
Sections II.A. through II.C., specify requirements for stationary 
sources (major and minor) to file emission notices. These notices 
provide information such as the location where a source's emissions 
will occur, the nature of the source or of the activity generating the 
expected emissions, and an estimate of the emissions' quantity and 
composition. The Colorado APEN provisions in Regulation Number 3, Part 
A, Section II.D. exempt specific categories of sources from APEN 
requirements.
    EPA's last final rulemaking action addressing revisions to 
Colorado's APEN provisions was published January 21, 1997 (62 FR 2910). 
The action proposed today addresses the APEN SIP revisions submitted by 
the State of Colorado between 1997 and 2007 with Governor's letters 
dated as follows: September 16, 1997; June 20, 2003; July 11, 2005; 
August 8, 2006; and August 1, 2007. EPA's evaluation of the revisions 
submitted by the State does not trace the APEN provision changes 
through each of the submissions noted above. For reasons of efficiency 
and clarity, EPA compared the language of each APEN provision as 
submitted by the State on August 1, 2007 with the EPA-approved text of 
the same APEN provision in the 1997 Colorado SIP. For each provision, 
the substantive language changes, EPA's proposed action, EPA's comments 
about the general nature of the changes, and the rationale for the 
Agency action are reported in Table 1 of the Technical Support Document 
(TSD) underpinning our proposed action.\1\ For actions involving a 
provision's proposed disapproval our analysis does reference and 
address relevant material supporting the revision's adoption by the 
State. In some cases, EPA asked the State for clarification of 
revisions; these clarifications are also available in the docket. 
Through this approach to the cumulative revisions, EPA intends for this 
proposed rule action to address all APEN revisions as submitted by the 
State of Colorado on September 16, 1997, June 20, 2003, July 11, 2005, 
August 8, 2006, and August 1, 2007.
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    \1\ EPA's Technical Support Document (TSD), part of the docket 
for this proposed action (accessible on the regulations.gov Web site 
under Docket Number EPA-R08-OAR-2007-0649) clearly identifies for 
each of the APEN provisions the cumulative effect of the revisions 
(if any) adopted by the State between 1997 and 2007. The TSD's Table 
1 lists all the APEN provisions (requirements and exemptions) and 
for each it provides: the provision number in the 1997 EPA-approved 
SIP, and in the 2007 State submittal; a short description or title 
of the provision, and cumulative language changes from 1997 to 2007; 
EPA's proposed action (Approval, Disapproval, or No Action); and 
EPA's comments summarizing the nature of the changes, and providing 
a rationale for supporting the proposed action. EPA believes that 
this approach allows a clear understanding of the overall revisions 
adopted by the State for each provision and of the rationale for the 
Agency's proposed action. The cumulative revisions identified in 
Table 1 of the TSD were part of the Colorado submissions dated 
September 16, 1997, June 20, 2003, July 11, 2005, August 8, 2006 and 
August 1, 2007.
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III. What action is EPA proposing?

    EPA is proposing: (a) To approve some of the revisions to the 
Colorado APEN provisions submitted to EPA on September 16, 1997; June 
20, 2003; July 11, 2005; August 8, 2006; and August 1, 2007; (b) to 
disapprove some of the revisions; and (c) to not take action on a few 
revisions unrelated to the SIP or to maintenance of the National 
Ambient Air Quality Standards (NAAQS). As mentioned in section II 
above, the specific provisions we propose to approve, disapprove, or 
not act on are identified in the TSD; those that require extended 
analysis are discussed in section V below.

IV. What is the State process to submit these materials to EPA?

    Section 110(k) of the CAA addresses EPA's rulemaking action on SIP 
submissions by states. The CAA requires states to observe certain 
procedural requirements in developing SIP revisions for submittal to 
EPA. 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 EPA.
    The Colorado Air Quality Control Commission (AQCC) held public 
hearings for, and adopted, on March 31, 1996 the APEN revisions 
submitted to EPA September 16, 1997. On June 20, 2003 Colorado 
submitted two APEN revision packages. For the first package, public 
hearing and adoption dates were respectively February 21 and July 18, 
2002. For the second, the revisions were submitted to public hearing 
and adopted on the same October 17, 2002 date. For APEN revisions 
submitted to EPA on July 11, 2005, the Colorado AQCC held public 
hearings February 19, April 15, and April 16, 2004, and adopted the 
revisions on the latter date. The Colorado AQCC held a public hearing 
on December 16, 2004 for APEN revisions adopted the same day and 
submitted to EPA August 8, 2006. For the last of the submissions 
considered in this action, APEN revisions submitted to EPA on August 1, 
2007, the Colorado AQCC public hearing and adoption took place on 
August 17, 2006.
    EPA has reviewed the submittals by the State of Colorado and has 
determined that the State met the requirements for reasonable notice 
and public hearing under section 110(a)(2) of the CAA. All Colorado 
APEN

[[Page 4273]]

revisions submittals referenced above, and addressed in this action, 
became complete by operation of law under section 110(k)(1)(B) of the 
CAA six months after their submittal dates.

V. EPA's Review and Technical Information

    As indicated in the Background section of this action, for each of 
the APEN provisions in Regulation Number 3, Part A, Sections II.A. 
through II.D., EPA's TSD identifies the cumulative revisions submitted 
by the State between 1997 and 2007, provides EPA's assessment of the 
revisions, and indicates EPA's proposed action (approval, no action, or 
disapproval). The TSD compares the cumulative revisions of each APEN 
provision with the current EPA-approved language of the same provision, 
effective as of February 20, 1997.\2\ For revisions to APEN provisions 
that must be addressed in greater detail, EPA's evaluation references 
the specific submittal or submittals affecting the changes, their 
related material, as well as any subsequent information/clarification 
provided to EPA by the State of Colorado. All material contributing to 
EPA's proposed action is referenced appropriately and made available 
for review as part of the docket supporting the Agency's proposed 
rulemaking.
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    \2\ 62 FR 2910, January 21, 1997.
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    For clarity, EPA's evaluation of the APEN revisions submitted by 
the State of Colorado between 1997 and 2007 considers four groups 
identified according to EPA's action. The first group consists of the 
APEN provisions that the State did not revise between September 1997 
and August 2007. These provisions retained in the 2007 APEN submission 
are the same language as the provisions in the 1997 EPA-approved 
Colorado SIP. For this group of APEN provisions there are no SIP 
revisions for EPA to propose action on. The second group consists of 
the APEN provisions for which the State had adopted only clerical 
changes, such as grammar or style changes, that do not reflect any 
substantive modifications. For example, some of the changes expanded 
abbreviations such as ``APEN,'' and others replaced the digits of a 
numerical value with its equivalent text--i.e., ``four hundred'' 
instead of ``400.'' EPA proposes to approve all the clerical revisions 
submitted by the State of Colorado between September 16, 1997 and 
August 1, 2007.
    The third and fourth groups consist of the Colorado APEN provisions 
that underwent substantive revisions; the third group are those 
provisions EPA proposes to approve and the fourth those EPA proposes to 
disapprove. In general, our evaluation of each substantive revision 
assesses whether the revision makes the SIP more or less stringent, or 
weakens protection of the NAAQS. In carrying this out, we consider 
whether the revisions satisfied recordkeeping and reporting 
requirements set out in 40 CFR 51.211. We also consider whether the 
revisions affected the applicability of substantive provisions 
elsewhere within the SIP. In particular, a source that is exempt from 
APEN requirements is also exempt from construction permitting 
requirements (see Regulation 3, Part B, Section III.D.1.a). As a 
result, the requirements for stationary sources at 40 CFR 51.160 are 
implicated by the submitted APEN exemptions we review in this proposal.
    For many of the provisions affected by the substantive revisions 
submitted by the State, EPA's rationale for its proposed action is 
explained and provided in Table 1 of the TSD. For the remaining 
provisions, affected by revisions requiring more complex and detailed 
evaluations, we do so in the following paragraphs.
    We examine first the revisions that EPA proposes to approve, in the 
order as they appear in Regulation 3. Provision II.B.1.b.\3\ pertains 
to alternative methods for emissions estimates. The language of the 
1997 EPA-approved provision included a reference to ``Section II.E.2. 
of this Regulation No. 3, Part A.,'' which addressed deferrals of APEN 
reporting timelines--a subject unrelated to the issue of emissions 
estimates and alternative methods. This reference was an obvious 
clerical error corrected by the State, with the June 20, 2003 
submission,\4\ to ``Section II.C.2.'' The corrected reference, on the 
other hand, specifies thresholds for significant emission changes, 
which relate to the accuracy required for emission estimates. The lower 
the significant emission changes threshold, the greater the precision 
required of an acceptable alternate emissions estimate. EPA therefore 
proposes to approve this correction.
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    \3\ Unless otherwise specified, all references to sections in 
the remainder of this notice are to sections in Part A of Regulation 
3.
    \4\ This revision was adopted by Colorado AQCC July 18, 2002.
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    EPA also proposes to approve revisions to II.B.3.a., which sets 
thresholds (in tons per year) of criteria pollutants for APEN 
applicability. The revisions clarify the understanding that the one ton 
per year (tpy) threshold in nonattainment areas applies to the 
pollutants for which the area is in nonattainment. EPA proposes 
approval of this revision because the change does not make the SIP less 
stringent or affect the ambient air quality.
    Next, APEN provision II.B.9. of the EPA-approved SIP identifies 
criteria pollutants for the purpose of APEN applicability. The Colorado 
AQCC adopted on April 16, 2004 the revised provision that was submitted 
to EPA on July 11, 2005; Colorado retained the same language in the 
August 8, 2006 and August 1, 2007 submissions. The revision generally 
defines criteria pollutants as those for which EPA has established a 
NAAQS. The revision also identifies NOx and volatile organic compounds 
(VOCs) as precursors to ozone. EPA proposes approval of this revision 
because it makes the definition of criteria pollutants (for the 
purposes of APEN applicability) consistent with the federal definition. 
In the same submittal, the AQCC renumbered the provision to I.B.16. EPA 
is also proposing to approve this renumbering, which does not affect 
the applicability of the provision. EPA notes that since prior to this 
renumbering Section I.B.16 was ``reserved,'' the move of II.B.9 to this 
section does not replace any other provision, and therefore does not 
impact the stringency of the SIP.
    EPA is also proposing to approve the revision to II.C.1.h. 
submitted on July 11, 2005. The revision is intended to update the 
reference to the definition of ``major stationary source.'' However, 
the reference specified, Section II.A.25., gives the definition of 
``Minor Source Baseline Date,'' while Section II.A.24. defines ``Major 
Stationary Source.'' EPA has discussed this with the State; the State 
concurs that the reference should be ``Section II.A.24.'' and has 
agreed to correct this discrepancy in a later submittal to EPA. Given 
that the correct reference can be determined from the context, EPA 
proposes approval of the revision.
    A revision to II.C.3.d was submitted to EPA on August 8, 2006. The 
revised provision changes the time APENs are due for control equipment 
at condensate storage tanks located at oil and gas exploration 
facilities. However, the revision does not exempt such sources from 
reporting and therefore does not relieve them from any substantive 
requirements of the SIP. As the revision does not impact emission 
levels and ambient air quality standards, EPA is proposing to approve 
it.
    We turn to exemptions from APEN requirements that have been added 
to Section II.D.1 in the submittals. First, II.D.1.nnn exempts 
``Fugitive emissions

[[Page 4274]]

of hazardous air pollutants that are natural constituents of native 
soils and rock (not added or concentrated by chemical or mechanical 
processes) from underground mines or surface mines unless such source 
is a major source of hazardous air pollutants under Part C of 
Regulation No. 3.'' The provision was adopted on March 31, 1996, and 
submitted to the EPA on September 16, 1997. This exemption will not 
affect any substantive requirement in the SIP relating to emissions of 
criteria pollutants and thus EPA is proposing approval.
    EPA is also proposing approval of the exemption in APEN provision 
II.D.1.ooo: ``The use of pesticides, fumigants, and herbicides when 
used in accordance with requirements established under the Federal 
Insecticide, Fungicide and Rodenticide Act as established by the U.S. 
EPA (United States Code Title 7, Section 136 et seq.).'' The exemption 
was adopted on March 31, 1996, and submitted to the EPA on September 
16, 1997. Such sources are not elsewhere regulated in the SIP and 
therefore EPA proposes approval of this exemption.
    The exemption in II.D.1.ppp, ``Ventilation of emissions from mobile 
sources operating within a tunnel, garage, or building,'' was submitted 
to EPA on September 16, 1997. EPA proposes approval of this revision to 
the Colorado APEN SIP on the basis of the following considerations. The 
Colorado APEN reporting requirements are applicable only to stationary 
sources (see Regulation Number 3, Part A, Section II.A.). Section 
302(z) of the (CAA) defines stationary sources as ``any source of an 
air pollutant except those emissions resulting from an internal 
combustion engine for transportation purposes * * *.'' The exemption 
applies only when a mobile source (as defined in Regulation 3) is 
operating for transportation purposes. We recommend that in a future 
SIP revision the State of Colorado clarify the applicability of the 
current provision.
    EPA also proposes to approve the exemption in Section II.D.1.dddd., 
applicable to ``Non-road engines as defined in Section I.B.29. of this 
Part A, except certain non-road engines subject to state-only air 
pollutant emission notice and permitting requirements pursuant to 
Section I.B.29.c. of this part.'' The definition of non-road engines in 
Section I.B.29 is consistent with the federal definition of non-road 
engine at 40 CFR 1068.30. Under section 302(z) of the CAA non-road 
engines are specifically excluded from the definition of stationary 
sources, to which the Colorado APEN requirements apply (see Section 
II.A.).
    APEN substantive revisions submitted by the State to EPA between 
September 16, 1997 and August 1, 2007 include revisions to or additions 
of five exemption provisions that EPA proposes to disapprove. The first 
revision we propose to disapprove regards the APEN exemption for open 
burning activities, in Section II.D.1.q. During the period considered 
here, some of the open burning provisions were moved by the State from 
Regulation Number 1 to Regulation Number 9 (which is a State-only 
Regulation, and therefore outside the Colorado SIP) and then back to 
Regulation Number 1. At the same time, Colorado submitted a June 20, 
2003 revision of the ``Open burning activities'' provision in Section 
II.D.1.q. that changed a reference to Regulation Number 1 (part of the 
Colorado SIP) into a reference to Regulation Number 9. Since, as noted 
above, Regulation Number 9 is enforceable only by the State, EPA 
proposes to disapprove the change to the reference to Regulation Number 
9.
    EPA is proposing to disapprove the APEN provision at Section 
II.D.1.xxx. exempting ``Deaerator/vacuum pump exhausts,'' adopted on 
March 31, 1996 and submitted to EPA on September 16, 1997. This 
provision would potentially exempt emissions both from the devices and 
from the liquid or gas the device operates on. If the liquid or gas 
operated on contains high levels of criteria pollutants or their 
precursors (either in a dissolved form in liquid or mixed in gas), then 
high levels of criteria pollutants may be emitted from these devices. 
As APEN exemptions are linked to exemption from construction 
permitting, this exemption may increase emissions of criteria 
pollutants (or their precursors). Under section 110(l) of the Act, EPA 
cannot approve a SIP revision if it would interfere with any applicable 
requirement concerning attainment and reasonable further progress or 
any other applicable requirement of the Act. Furthermore, as these 
stationary sources may emit significant amounts of criteria pollutants, 
the exemption from permitting fails to ensure that construction or 
modification of these sources will not interfere with attainment or 
maintenance of the NAAQS (see 40 CFR 51.160(a)(2)). EPA therefore 
proposes to disapprove the exemption in II.D.1.xxx.
    EPA also proposes to disapprove APEN exemption A-II.D.1.sss and its 
subprovisions A-II.D.1.sss.(i) through A-II.D.1.sss.(iii). This 
provision exempts three tiers of stationary internal combustion engines 
from APEN requirements. The tiers are defined by engine horsepower and 
hours of operation per year: (1) Those engines less than or equal to 
175 horsepower that operate less than 1450 hours per year; (2) those 
greater than 175 horsepower and less than or equal to 300 horsepower 
that operate less than 850 hours per year; and (3) those greater than 
300 horsepower that operate less than 340 hours per year. As a result 
of the exemption from APEN requirements, such engines are also exempt 
from construction permit requirements in Part B of Regulation 3 (see 
Part B, Section III.D.1.a).
    The provision does not require owners or operators that claim the 
exemption to keep records of the hours of operation. As a result, the 
limit on the hours of operation is unenforceable. In parallel instances 
where a source seeks to limit its potential to emit (``PTE'') through 
an operational limitation (such as on hours of operation) in a permit, 
EPA guidance recommends that the limitation be enforceable as a 
practical matter. (Memorandum from Terrell E. Hunt & John S. Seitz 
entitled ``Guidance on Limiting Potential to Emit in New Source 
Permitting'' (June 13, 1989).) The guidance specifically notes, 
``permits with limits on hours of operation * * * should require an 
operating log in which the actual hours of operation * * * are 
recorded.'' (Id. at 6.) The logs should be made available to the 
permitting authority, which allows it to verify compliance with the 
limit. Although this recommendation is in the context of practical 
enforceability of operational limitations in a permit, the underlying 
principle applies to enforceability of SIP provisions. Section 
110(a)(2)(A) of the CAA requires that emission limitations in a SIP be 
enforceable.\5\ Under the principle set out in the guidance discussed 
above, the provision is unenforceable, as there is no requirement to 
keep records of hours of operation.
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    \5\ In addition, 40 CFR 51.160(a)(1) requires SIPs contain 
legally enforceable procedures for determining whether construction 
or modification of a stationary source will violate applicable 
portions of the control strategy, and 40 CFR 51.211(b) requires SIPs 
contain legally enforceable procedures for requiring owners and 
operators of stationary sources to keep records necessary to 
determine compliance with applicable portions of the control 
strategy.
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    Without an enforceable limit on the hours of operations, engines in 
even the lowest tier (175 horsepower or less) may emit up to 8.4 tons 
per year (``tpy'') of NOX for gasoline fuel or 23.8 tpy of 
NOX for diesel fuel, if operated for the full year. This is 
considerably above the level for the existing source-specific

[[Page 4275]]

exemption from construction permitting for stationary internal 
combustion engines (Part B, III.D.1.c(iii)), which is capped at 5 tons 
per year.
    This in turn raises another issue. Section 110(l) of the Act 
provides that EPA shall not approve a SIP revision if it would 
interfere with any applicable requirement concerning attainment and 
reasonable further progress or any other applicable requirement of the 
Act. Due to the linked exemption from construction permitting, 
emissions of criteria pollutants and their precursors (such as, again, 
NOX) may increase as a result of the exemption from APEN 
requirements. For this reason, and for the reason that the provision 
appears to be unenforceable, EPA proposes to disapprove the addition of 
the exemption in A.II.D.1.sss to the SIP.
    Similar issues are raised by the exemption in A-II.D.1.ttt. This 
provision exempts three tiers of emergency power generators from APEN 
requirements: (1) Those with a rated horsepower of less than 260; (2) 
those that operate no more than 250 hours per year and have a rated 
horsepower of less than 737; and (3) those that operate no more than 
100 hours per year and have a rated horsepower of less than 1,840. For 
similar reasons to those discussed above, EPA regards the limitations 
on hours in tiers 2 and 3 as unenforceable and therefore proposes to 
disapprove subprovisions A-II.D.1.ttt.(ii) and A-II.D.1.ttt.(iii). 
Sources in tier 1, on the other hand, do not have a limit on hours of 
operation. However, as tier 1 includes generators up to 260 hp, 
emissions from these sources may be even greater than the emissions 
from the first tier stationary internal combustion engines discussed 
above. As with those engines, this raises the issue of compliance with 
section 110(l) of the Act. EPA therefore proposes to also disapprove 
the exemption in A-II.D.1.ttt.(i).
    EPA also proposes to disapprove the exemption in Section 
II.D.1.ffff., applicable to ``Air Curtain Destructors burning only yard 
waste, wood waste, and clean lumber, or any mixture thereof generated 
as a result of projects to reduce the risk of wildfire and are not 
located at a commercial or industrial facility.'' The exemption does 
not apply to ``[a]ir curtain incinerators that are considered 
incinerators as defined by the Common Provisions.'' The exemption in 
II.D.1.ffff. was submitted to EPA on August 1, 2007.
    Under the definition of ``incinerator'' in a subsequent revision to 
the Common Provisions of Colorado's SIP, air curtain destructors that 
are subject to a New Source Performance Standard (NSPS) are considered 
``incinerators.'' On December 16, 2005, EPA published a final rule (70 
FR 74870) for NSPS and emission guidelines for new and existing 
``other'' solid waste incineration units (OSWI). Under this rule, air 
curtain destructors (called air curtain incinerators in the rule) are 
subject to an NSPS. As a result, this exemption, II.D.1.ffff., is 
superseded. Additionally, Colorado has agreed that this exemption, 
II.D.1.ffff., is no longer valid and thus EPA is proposing disapproval.
    APEN revisions submitted by the State to EPA between September 16, 
1997 and August 1, 2007 include revisions to six provisions that EPA 
proposes to take no action on. The first revisions we propose to take 
no action on are: II.D.1.m; II.D.1.ee; II.D.1.uu; II.D.1.ddd; and 
II.D.1.eeee. EPA is proposing to not act on these provisions in this 
Federal Register action, because EPA has already proposed approval of 
the repeal of these exemptions in a separate action published on July 
21, 2010 (75 FR 42346). Additionally, EPA is not proposing action on 
the revision to APEN exemption II.D.1.uuu., because we proposed 
approval of the revision in the same July 21, 2010 proposal.

VI. Proposed Action

    EPA is proposing partial approval and partial disapproval of the 
Colorado SIP revisions for APEN requirements and exemptions submitted 
by the State on September 16, 1997, June 20, 2003, July 11, 2005, 
August 8, 2006, and August 1, 2007. As noted above, EPA's evaluation of 
the revisions submitted by the State does not track the APEN provision 
changes through each of the submissions (to avoid having to evaluate 
revisions that may be significantly modified or even reversed in 
subsequent submittals), but for each provision compares the textual 
changes between the EPA-approved Colorado APEN provisions effective 
February 21, 1997, and the Colorado-adopted APEN provisions included 
with the August 1, 2007 submittal. This approach allows EPA to 
evaluate, for each provision, the cumulative revisions submitted by the 
State on the dates specified above.
    A comprehensive summary of the Colorado APEN provisions in 
Regulation Number 3, Part A, Section II, organized by EPA's proposed 
rule action, is provided in Table 2 below. The APEN provision numbers 
are as codified in the August 1, 2007 submission.

Table 2--List of Colorado APEN Provisions (Requirements and Exemption in
    Sections II.A through II.D of Part A, Regulation Number 3) by EPA
                          Proposed Rule Action
------------------------------------------------------------------------
                                     APEN provision number in August 1,
       EPA's proposed action                   2007 submission
------------------------------------------------------------------------
Approval--Substantially Revised     II.A; II.B.1.b; II.B.3; II.B.3.a;
 Provisions.                         II.C.1.h; II.C.2.b.(ii); II.C.3.c;
                                     II.C.3.d; II.D.1;
                                    II.D.1.a; II.D.1.f; II.D.1.g;
                                     II.D.1.i; II.D.1.nn; II.D.1.oo;
                                     II.D.1.ccc; II.D.1.fff; II.D.1.lll;
                                    II.D.1.nnn. through II.D.1.qqq;
                                     II.D.1.rrr; II.D.1.vvv; II.D.1.www;
                                     II.D.1.yyy through II.D.1.dddd;
                                    II.D.4. through II.D.6.
Approval--Provisions with Clerical  II.B.1; II.B.2; II.B.4.a. through
 Revisions.                          II.B.4.f; II.C. through II.C.1.a;
                                     II.C.2;
                                    II.C.2.b; II.C.2.b.(i);
                                     II.C.2.b.(iii). through II.C.3.b;
                                     II.D; II.D.1.h; II.D.1.j; II.D.1.k;
                                    II.D.1.n; II.D.1.x; II.D.1.y;
                                     II.D.1.aa; II.D.1.bb; II.D.1.kk;
                                     II.D.1.aaa;
                                    II.D.1.bbb; II.D.1.ggg; II.D.2;
                                     II.D.3.
Disapproval--Substantially Revised  II.D.1.q; II.D.1.sss; II.D.1.ttt;
 Provisions.                         II.D.1.xxx; II.D.1.ffff.
No Action--EPA's Prior Proposed     II.D.1.m; II.D.1.ee; II.D.1.uu;
 Action.                             II.D.1.ddd; II.D.1.uuu;
                                     II.D.1.eeee.
No Action--Un-Revised Provisions..  II.B; II.B.1.a; II.B.3.b; II.B.4;
                                     II.B.5; II.B.6; II.C.1.b. through
                                     II.C.1.g;
                                    II.C.2.a; II.D.1.b. through
                                     II.D.1.e; II.D.1.i.(i). through
                                     II.D.1.i.(iii); II.D.1.l;
                                    II.D.1.o; II.D.1.p; II.D.1.r.
                                     through II.D.1.w; II.D.1.z;
                                     II.D.1.cc; II.D.1.dd;
                                    II.D.1.ff. through II.D.1.jj;
                                     II.D.1.ll; II.D.1.mm; II.D.1.pp.
                                     through II.D.1.tt;
                                    II.D.1.vv. through II.D.1.zz;
                                     II.D.1.eee; II.D.1.hhh. through
                                     II.D.1.kkk;
                                    II.D.1.mmm.
------------------------------------------------------------------------


[[Page 4276]]

    In addition, EPA is proposing approval of certain other deletion 
and renumbering of APEN requirements. The provisions (using the 
numbering from the EPA-approved SIP, effective February 21, 1997) that 
are proposed for deletion are: II.B.8., II.B.10., and II.D.4.b. 
Deletion of the exemptions in II.D.4.b. makes the SIP more stringent, 
and deletion of the other provisions does not impact APEN requirements 
and exemptions, nor any other SIP provisions. EPA therefore proposes to 
approve these deletions. EPA's proposed approval of the renumbering of 
APEN requirements will be for the entirety of the language and their 
new location in Section I.B. The provision references, before the 
renumbering, were: II.B.5. and II.B. 9. The references, after the 
renumbering, are, respectively: I.B.43 and I.B.16. The renumbering of 
these provisions does not impact APEN requirements and exemptions, nor 
any other SIP provisions.
    As indicated in the Background section of this action, for each of 
the APEN provisions in Regulation Number 3, Part A, Sections II.A. 
through II.D., EPA's TSD identifies the cumulative revisions (if any) 
submitted by the State between 1997 and 2007, provides its assessment 
of the revisions within the regulatory context referenced earlier in 
this action, and indicates EPA's proposed action (approval, no action, 
or disapproval.)

VII. Statutory and Executive Order Reviews

    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. 
Accordingly, this action merely approves state law as meeting Federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this 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 rule does not have tribal implications as specified 
by Executive Order 13175 (65 FR 67249, November 9, 2000), because the 
SIP is not 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, Incorporation by 
reference, Intergovernmental relations, Nitrogen dioxide, Ozone, 
Particulate matter, Reporting and recordkeeping requirements, Volatile 
Organic Compounds.

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

    Dated: January 13, 2011.
Carol Rushin,
Acting Regional Administrator, Region 8.
[FR Doc. 2011-1477 Filed 1-24-11; 8:45 am]
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