[Federal Register Volume 76, Number 186 (Monday, September 26, 2011)]
[Proposed Rules]
[Pages 59338-59344]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-24697]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2011-0100; FRL-9471-4]


Approval and Promulgation of Air Quality Implementation Plans; 
Montana; Revisions to the Administrative Rules of Montana--Air Quality, 
Subchapter 7, Exclusion for De Minimis Changes

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to partially approve and partially disapprove 
State Implementation Plan (SIP) revisions submitted by the State of 
Montana on June 25, 2010 and May 28, 2003. The revisions contain new 
and amended rules in Subchapter 7 (Permit, Construction, and Operation 
of Air Contaminant Sources) that pertain to the issuance of Montana air 
quality permits, in addition to other minor administrative changes to 
the Administrative Rules of Montana. The intended effect of this action 
is to propose to approve the rules that are approvable and to propose 
to disapprove the rules that are inconsistent with the Clean Air Act 
(CAA.) This action is being taken under section 110 and 112 of the CAA.

DATES: Comments must be received on or before October 26, 2011.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2011-0100, by one of the following methods:
     http://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     E-mail: [email protected].
     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, Environmental 
Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop Street, 
Denver, Colorado 80202-1129.
     Hand Delivery: Carl Daly, Director, Air Program, 
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 
Wynkoop Street, Denver, Colorado 80202-1129. Such deliveries are only 
accepted Monday through Friday, 8 a.m. to 4:30 p.m., excluding Federal 
holidays. Special arrangements should be made for deliveries of boxed 
information.
    Instructions: Direct your comments to Docket ID No. EPA-R08-OAR-
2011-0100. 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 e-mail. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA, without 
going through http://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm. For additional instructions on submitting 
comments, go to Section I. General Information of the SUPPLEMENTARY 
INFORMATION section of this document.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly-available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the Air Program, 
Environmental Protection Agency (EPA), Region 8, 1595 Wynkoop Street, 
Denver, Colorado 80202-1129. EPA requests that if at all possible, you 
contact the individual listed in the FOR FURTHER INFORMATION CONTACT 
section to view the hard copy of the docket. You may view the hard copy 
of the docket Monday through Friday, 8 a.m. to 4 p.m., excluding 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Kevin Leone, Air Program, Mailcode 8P-
AR, Environmental Protection Agency, Region 8, 1595 Wynkoop Street, 
Denver, Colorado 80202-1129, (303) 312-6227, or [email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
II. Background
III. What Authorities Apply to EPA's Proposed Action
IV. EPA's Analysis and Proposed Actions on SIP Revisions
V. Summary of Proposed Actions
VI. Statutory and Executive Order Reviews

Definitions

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

I. General Information

A. What should I consider as I prepare my comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
http://www.regulations.gov or e-mail. Clearly mark the part or all of 
the information that you claim to be CBI. For CBI information in a disk 
or CD ROM that you mail to EPA, mark the outside of the disk or CD ROM 
as CBI and then identify electronically within the disk or CD ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a

[[Page 59339]]

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

    In response to Montana legislation adopted in 1995, (House Joint 
Resolution No. 22, Montana's June 25, 2010 SIP Submittal Package, Tab 
15, Attachment 2), on August 9, 1996, the Montana Board of 
Environmental Review (Board) adopted the initial de minimis rules, 
Administrative Rules of Montana (ARM) 16.8.1102, 16.8.1113 and 
16.8.1121 as part of Montana's air quality preconstruction permit 
program rules. These rules created an exemption from the requirement to 
obtain an air quality permit modification for certain changes at a 
permitted facility that did not increase the facility's potential 
emissions of an air pollutant by more than 15 tons per year, when 
conditions specified in the rule were met. On December 9, 1996, the 
Board recodified its rules, including the following recodification of 
the de minimis rules: ARM 16.8.1102 became 17.8.705; 16.8.1113 became 
17.8.733 and 16.8.1121 became 17.8.708. On May 14, 1999, the Board 
revised ARM 17.8.705 and 17.8.733 and repealed 17.8.708. The Governor 
of Montana submitted the Board's August 9, 1996 and May 14, 1999 
rulemaking actions to EPA on August 26, 1999, for inclusion in the SIP. 
On December 6, 2002, the Board repealed ARM 17.8.705 and 17.8.733, 
which the Board incorporated into a new rule, ARM 17.8.745, the State's 
current de minimis rule. On May 28, 2003, the Governor submitted the 
new rule to EPA for inclusion in the SIP and rescinded the previous 
submissions of ARM 17.8.705 and 17.8.733.
    During the State's 1996 and 1999 rulemaking process we expressed 
concerns with the de minimis level specified in the earlier versions of 
the regulation we are proposing action on today (see letters from EPA 
to the State of Montana dated July 25, 1996, April 1, 1999 and October 
9, 2002 in the docket). ARM 17.8.745 created an exemption from the 
requirement to obtain an air quality permit or permit modification for 
certain changes at a permitted facility that did not increase the 
facility's potential emissions of an air pollutant by more than 15 tons 
per year, when conditions specified in the rule were met. Since this 
new rule reduced the stringency of the current SIP approved 
regulations, EPA indicated that the State must provide an analysis 
showing that the new rule will not interfere with compliance with the 
National Ambient Air Quality Standards (NAAQS) or Prevention of 
Significant Deterioration (PSD) increments. Section 110(l) of the CAA 
states that EPA cannot approve a SIP revision that would interfere with 
any applicable requirement concerning attainment or reasonable further 
progress (RFP), as defined in section 171 of the CAA, or any other 
applicable requirement of the CAA. Montana's May 28, 2003 submittal did 
not provide any analysis or demonstration that the new rule (ARM 
17.8.745) meets these requirements. In EPA's final July 8, 2011 
rulemaking (76 FR 40237) which approved revisions to ARM 17.8.7, no 
action was taken on Montana's de minimis provision in ARM 17.8.745. 
Since EPA took no action on ARM 17.8.745 in our 76 FR 40237 notice, we 
took no action on all references to ARM 17.8.745 in ARM 17.8.7.
    On June 25, 2010, the Governor of Montana submitted the Board's May 
14, 2010 rulemaking action to EPA for inclusion in the SIP. This 
revision request for ARM 17.8.745, which supercedes the State's May 28, 
2003 submittal for ARM 17.8.745, created an exemption from the 
requirement to obtain an air quality permit or permit modification for 
certain changes at a permitted facility that did not increase the 
facility's potential emissions of an air pollutant by more than five 
tons per year, when conditions specified in the rule were met. In this 
action EPA proposes to act on two submittals: (1) The May 28, 2003 SIP 
revision request; and (2) the June 25, 2010 SIP revision request, which 
amended the 2003 submittal.
    The State's May 28, 2003 submittal also included ARM 17.8.743, 
which was a new rule. ARM 17.8.743(1) describes those sources that are 
required to obtain a Montana air quality permit. ARM 17.8.743(1) 
provides that any new or modified facility or emitting unit that has 
the potential to emit more than 25 tons per year of any airborne 
pollutant, except lead,\1\ must obtain a Montana air quality permit 
except as provided in ARM 17.8.744 and ARM 17.8.745 before 
constructing, installing, modifying or operating. ARM 17.8.431(1)(b) 
also requires asphalt concrete plants, mineral crushers, and mineral 
screens that have the potential to emit more than 15 tons per year of 
any airborne pollutant, other than lead, to obtain a Montana air 
quality permit.
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    \1\ Facilities or emitting units that emit airborne lead must 
obtain a Montana air quality permit if they are new and emit greater 
than five tons per year of airborne lead, or if they are an existing 
facility or emitting unit and a modification results in an increase 
of airborne lead by an amount greater than 0.6 tons per year.
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    This notice also contains EPA's proposed action on Montana rules 
relating to the permitting threshold for asphalt concrete plants and 
mineral crushers. In our July 8, 2011 rulemaking, EPA approved of all 
of new section ARM 17.8.743(1), except for the phrase ``asphalt 
concrete plants and mineral crushers'' where the de minimis permitting 
threshold for those sources was changed from five tons per year to 15 
tons per year. During the State's rulemaking process we expressed 
concerns with the new permit threshold for asphalt concrete plants and 
mineral crushers. (See October 9, 2002, letter from EPA to the State of 
Montana in the docket.) Since for asphalt concrete plants and mineral 
crushers this revision (ARM 17.8.743(1)(b)) reduces the stringency of 
the current SIP approved regulations, which has a threshold of 5 tons, 
we stated that Montana must provide an analysis showing that this new 
rule will not interfere with compliance with the NAAQS or PSD 
increments. Section 110(l) of the CAA states that EPA cannot approve a 
SIP revision that would interfere with any applicable requirement 
concerning attainment or reasonable further progress, as defined in 
Section 171 of the CAA, or any other applicable requirement of the CAA. 
Montana did not provide any analysis or

[[Page 59340]]

demonstration that the increased permit threshold, from five tons per 
year to 15 tons per year, for asphalt concrete plants and mineral 
crushers meets these criteria. At the request of the State, we took no 
action on the phrase ``asphalt concrete plants, mineral crushers'' in 
ARM 17.8.743(1)(b) in 76 FR 40237. EPA is proposing action on the May 
28, 2003, SIP revision request for 17.8.743(1)(b) in this action.

III. What Authorities Apply to EPA's Proposed Action

    Section 110(l) of the CAA states: Each revision to an 
implementation plan submitted by a State under this Act shall be 
adopted by such State after reasonable notice and public hearing. The 
Administrator shall not approve a revision to a plan if the revision 
would interfere with any applicable requirement concerning attainment 
and reasonable further progress (as defined in section 171), or any 
other applicable requirement of this Act.
    The States' obligation to comply with each of the NAAQS is 
considered as ``any applicable requirement(s) concerning attainment.'' 
A demonstration is necessary to show that this revision will not 
interfere with attainment or maintenance of the NAAQS, including those 
for ozone, particulate matter, carbon monoxide (CO), sulfur dioxide 
(SO2), lead, nitrogen oxides (NOX) or any other 
requirement of the Act.
    The CAA at section 110(a)(2)(C) requires states to include a minor 
New Source Review (NSR) program in their SIP to regulate modifications 
and new construction of stationary sources within the area as necessary 
to assure the NAAQS are achieved. EPA's implementing regulations at 40 
CFR 51.160-164 are intended to ensure that new source growth is 
consistent with maintenance of the NAAQS and 40 CFR 51.160(e) requires 
states to identify types and sizes of facilities which will be subject 
to review under their minor NSR program. For sources identified under 
40 CFR 51.160(e), section 51.160(a) requires that the SIP include 
legally enforceable procedures that enable a state or local agency to 
determine whether construction or modification of a facility, building, 
structure or installation, or combination of these will result in a 
violation of applicable portions of the control strategy; or 
interference with attainment or maintenance of a national standard in 
the state in which the proposed source (or modification) is located or 
in a neighboring state. Section 110(i) of the CAA specifically 
precludes states from changing the requirements of the SIP except 
through SIP revisions approved by EPA. SIP revisions will be approved 
by EPA only if they meet all requirements of section 110 of the CAA and 
the implementing regulations at 40 CFR part 51. See CAA section 110(l); 
40 CFR 51.104.
    EPA recognizes that, under the applicable Federal regulations, 
states have broad discretion to determine the scope of their minor NSR 
programs as needed to attain and maintain the NAAQS. The states have 
significant discretion to tailor minor NSR requirements that are 
consistent with the requirements of 40 CFR part 51. States may also 
provide a rationale for why the rules are at least as stringent as the 
40 CFR part 51 requirements where the revisions are different from 
those in 40 CFR part 51. For example, states may exempt from minor new 
source review certain categories of changes based on de minimis or 
administrative necessity grounds in accordance with the criteria set 
out in Alabama Power Co. v. Costle, 636 F.2d 323, 360-361 (D.C. Cir. 
1979). De minimis sources are presumed not to have an impact and their 
emissions would not prevent or interfere with attainment of the NAAQS, 
even within nonattainment areas.
    Since there are no ambient air quality standards for air toxics, 
the area's compliance with any applicable maximum achievable control 
technology (MACT) standards, as well as any Federal mobile source 
control requirements under CAA sections 112 or 202(l) would constitute 
an acceptable demonstration of noninterference for air toxics.
    Section 110(l) does not require a demonstration of noninterference 
for changes to Federal requirements that are not included in the SIP. A 
revision to the SIP, however, cannot interfere with any federally 
mandated program such as a MACT standard (or related section 112 
requirements) or Reid Vapor Pressure.
    The following is a table of the NAAQS that were in place at the 
time Montana submitted its new section ARM 17.8.745 and all references 
to ARM 17.8.745 for Federal approval on May 23, 2003, as well as the 
current NAAQS levels:

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                                      NAAQS level as of
        Criteria pollutant                   2003           Current NAAQS level          Date of revision
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Carbon Monoxide...................  35 ppm 1-hr Average..  35 ppm 1-hr Average..  August 31, 2011.
                                    9 ppm 8-hr Average...  9 ppm 8-hr Average...
Lead..............................  1.5 ug/m3 Quarterly    0.15 ug/m3 Rolling 3-  Nov. 12, 2008.
                                     Average.               month Average.
Nitrogen Dioxide..................  0.53 ppm Annual Mean.  0.53 ppm Annual Mean.  Feb. 9, 2010.
                                                           100 ppb 1-hour Avg...
Particulate Matter (PM10).........  150 ug/m3 24-hr Avg..  150 ug/m3 24-hr Avg..  Oct. 17, 2006.
                                    50 ug/m3 Annual Mean.
Particulate Matter (PM2.5)........  65 ug/m3 24-hr Avg...  35 ug/m3 24-hr Avg...  Oct. 17, 2006.
                                    15 ug/m3 Annual Mean.  15 ug/m3 Annual Mean.
Ozone.............................  0.12 ppm 1-hour Avg..  0.075 ppm 8-hour Avg.  Mar. 27, 2008.
                                    0.08 ppm 8-hour Avg..
Sulfur Dioxide, Primary Standard..  0.14 ppm 24-hour Avg.  75 ppb 1-hour Average  June 22, 2010.
                                    0.030 ppm Annual Mean
Sulfur Dioxide, Secondary Standard  0.5 ppm 3-hour Avg...  0.5 ppm 3-hour Avg...  May 22, 1996.
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    For this proposal EPA is using indicators such as ambient air 
quality analysis, air quality trends including air monitoring and air 
modeling and findings from past EPA-approved rules and attainment 
demonstrations to show noninterference. In this proposal we are taking 
into consideration the nature of the permitting requirement, its 
potential impact on the air quality in the area and the air quality of 
the area in which the permitting requirements apply.
    CAA Section 193, also referred to as the ``General Savings Clause'' 
requires that ``[n]o control requirement in effect or required to be 
adopted by an order, settlement agreement, or plan in effect before 
November 15, 1990, in any area which is a nonattainment area for any 
air pollutant may be modified after November 15, 1990, in any manner 
unless the modification ensures equivalent or greater emission 
reduction of such air pollutant.'' This proposed rulemaking and 
associated Technical Support Document (TSD) demonstrates that the 
requirements of CAA Section

[[Page 59341]]

193 have been met through consistent emission reductions in 
nonattainment areas compared to the current EPA approved SIP.

IV. EPA's Analysis and Proposed Actions on SIP Revisions

    In this proposed rulemaking, we are proposing to approve new 
section ARM 17.8.745 submitted by Montana on June 25, 2010. We are also 
proposing to approve all references to ARM 17.8.745, submitted by 
Montana on May 28, 2003. Specifically, the following phrases in 
17.8.740(8)(a) and (c), respectively, (1) ``except when a permit is not 
required under ARM 17.8.745'' and (2) ``except as provided in ARM 
17.8.745'', the phrase ``and 17.8.745'' in ARM 17.8.743(1) and the 
phrase ``the emission increase meets the criteria in ARM 17.8.745 for a 
de minimis change not requiring a permit in ARM 17.8.864(1)(b). We are 
also proposing to disapprove the phrase ``asphalt concrete plants and 
mineral crushers'' in ARM 17.8.743(1)(b) submitted by Montana on May 
28, 2003.

ARM 17.8.745

    De minimis Exemptions from minor NSR. The Montana permit to 
construct rules exempt non-major sources from permitting requirements 
if they meet all of several criteria. These criteria are:
    (1) Any construction or changed conditions of operation at a 
facility that would violate any condition in the facility's existing 
Montana air quality permit or any applicable rule contained in this 
chapter is prohibited, except as allowed in (2);
    (2) any construction or changed conditions of operation at a 
facility that would qualify as a major modification of a major 
stationary source under subchapters 8, 9, or 10 of this chapter;
    (3) any construction or changed conditions of operation at a 
facility that would affect the plume rise or dispersion characteristics 
of the emissions in a manner that would cause or contribute to a 
violation of an ambient air quality standard or an ambient air 
increment, as defined in ARM 17.8.804;
    (4) any construction or improvement project with a potential to 
emit more than 5 tons per year may not be artificially split into 
smaller projects to avoid permitting under this subchapter; and
    (5) emission reductions obtained through offsetting within a 
facility are not included when determining the potential emission 
increase from construction or changed conditions of operation, unless 
such reductions are made federally enforceable.
    ARM 17.8.745(1)(b) states that an owner or operator shall notify 
the department for specific changes, with exceptions listed in ARM 
17.8.745(1)(c); ARM 17.8.745(1)(d) includes the information the owner 
or operator must submit to the department if a notice is required under 
ARM 17.8.745(1)(b); ARM 17.8.745(1)(e) states that the notice 
requirements under ARM 17.8.745(1)(d) shall not supercede any 
requirements under 40 CFR parts 60, 61 or 63 (New Source Performance 
Standards and National Emission Standards for Hazardous Air 
Pollutants.)
    We evaluated ARM 17.8.745 using the Federal regulations under CAA 
section 110(a)(2)(c) and 40 CFR 51.160, including section 51.160(b), 
which requires states to have legally enforceable procedures to prevent 
construction or modification of a source if it would violate any SIP 
control strategies or interfere with attainment or maintenance of the 
NAAQS.
    We also evaluated the new rules using CAA section 110(l). Section 
110(l) provides that EPA cannot approve a SIP revision if the revision 
would interfere with any applicable requirement concerning attainment 
and RFP, or any other applicable requirement of the CAA. Therefore, EPA 
will approve a SIP revision only after a state has demonstrated that 
such a revision will not interfere (``noninterference'') with 
attainment of the NAAQS, Rate of Progress (ROP), RFP or any other 
applicable requirement of the CAA.
    EPA retains the discretion to adopt approaches on a case-by-case 
basis to determine what the appropriate demonstration of 
noninterference with attainment of the NAAQS, ROP, RFP or any other 
applicable requirement of the CAA should entail. In this instance, EPA 
asked the State to submit an analysis showing that the approval of new 
section ARM 17.8.745 would not violate section 110(l) of the CAA (see 
docket number EPA-R08-OAR-2011-0100); this is also referred to as a 
``demonstration of noninterference'' with attainment and maintenance 
under CAA section 110(l). In addition to the State's demonstration, EPA 
conducted its own analysis utilizing SIP-approved attainment plans, 
past rulemakings, stipulations, consent decrees, air modeling data and 
air monitoring data. The scope and rigor of the demonstration of 
noninterference conducted in this notice is appropriate given the air 
quality status of the State, and the potential impact of the revision 
on air quality and the pollutants affected.
    We interpret section 110(l) to apply to all requirements of the CAA 
and to all areas of the country, whether attainment, nonattainment, 
unclassifiable, or maintenance for one or more of the six criteria 
pollutants. The scope and rigor of an adequate section 110(l) 
demonstration of noninterference depends on the air quality status of 
the area, the potential impact of the revision on air quality, the 
pollutant(s) affected, and the nature of the applicable CAA 
requirements.
    As described above, the changes to ARM 17.8.745 (the de minimis 
rule) that would occur with EPA approval of this SIP revision submittal 
affect the entire State of Montana for all criteria pollutants, with 
the exception of lead. ARM 17.8.743(1)(a) already limits a modification 
to an existing facility or emitting unit that results in an increase in 
the facility or emitting unit's potential to emit airborne lead by an 
amount greater than 0.6 tons per year. Therefore, EPA needs to review 
the effect of the exemption statewide for all criteria pollutants, 
except lead, before we can determine whether we can approve the SIP 
revisions under CAA section 110(l).
    The Montana Department of Environmental Quality (MDEQ) has been 
implementing the de minimis rule for more than 13 years as a State 
approved rule. This State approved rule established a 15 tons per year 
de minimis threshold for requiring a Montana air quality permit when a 
facility is modified. As stated earlier in this notice, Montana's June 
25, 2010 SIP revision request revises the federally approved SIP de 
minimis level from zero to a five tons per year threshold. MDEQ 
submitted a statewide demonstration of noninterference, which includes 
an air quality analysis, showing the effects of the de minimis rule on 
each criteria pollutant related to SIP control strategies or 
interference with attainment or maintenance of the NAAQS, as well as 
all other related requirements of the CAA. The air quality analysis 
displayed past air quality trends and provided information regarding 
future implications of the de minimis rule (predictive analysis). We 
find that MDEQ used reasonable methods and appropriate data in 
estimating the emissions effects of the new exemption. The following is 
a summary of Montana's air quality for criteria pollutants:
1. Ozone
    A review of Montana's past monitoring data show no violations of 
the ozone NAAQS standard since 2001 (See TSD, pages 4-5.) Montana 
currently has no ozone nonattainment areas; and consequently, no

[[Page 59342]]

nonattainment area control plans with respect to ozone. On November 27, 
2008 Montana submitted to EPA assurances certifying Montana's SIP was 
adequate for addressing the 1997 ozone NAAQS revision (see docket). On 
July 22, 2011 EPA partially approved ``Infrastructure Requirements for 
the 1997 8-Hour Ozone National Ambient Air Quality Standard; Montana''.
    In March 2008, EPA again promulgated revisions to the NAAQS for 
ozone. The revision lowered the ambient standards from the previous 
level of 0.08 parts per million (ppm) to 0.075 ppm as averaged over an 
eight-hour period. In addition, EPA's analysis to support the 2008 
ozone NAAQS revision consistent with EPA's modeling of counties 
predicted to violate the new ozone standard in future years does not 
include any Montana counties. Using 2004-2006 data, EPA conducted a 
national scale air quality modeling analysis to estimate future year 
attainment/nonattainment for ozone.
    Rural ozone monitoring currently occurs in Glacier National Park 
and near Sidney in eastern Montana. Glacier National Park data from 
2001-2008 shows continued attainment with the revised ozone standard 
(See TSD, Figures 1-3.) The Sidney monitor was located in proximity to 
oil and gas industry development activities. Monitoring began at the 
Sidney site in October, 2008, and initial data shows attainment with 
the revised 8 hour ozone standard.
    Data from Montana's past monitoring in the Billings area (the area 
in which conditions conducive to ozone formation are most likely to 
occur) does not show a violation of the revised 2008 NAAQS. Montana 
conducted three years of ozone monitoring (June-September, 2007-2010) 
in the Billings area (Shepherd Bard site) and two years of ozone season 
monitoring in the Missoula area (Frenchtown site) (See TSD, Figures 2-
3.) Based on factors including, but not limited to, population density, 
area-wide vehicle miles traveled, and existing industrial activity 
(including oil and gas industry development), Montana determined these 
locations represent the areas with the highest potential for ozone 
formation. The design value for the Billings area was determined during 
2005-2007 to be 0.059 ppm or 78.7% of the revised ozone NAAQS. Data 
from Missoula indicated an even lower design value.
    Based on future estimates and projections of the number of de 
minimis notices (See TSD pages 36-41) and the minimal likely effect of 
the de minimis rule on VOC and NOX emissions and monitoring 
data that show the area has attained the 8-hour ozone and 1-hour ozone 
NAAQS, we propose to find that approving the de minimus rule would not 
interfere with attainment of the 8-hour ozone NAAQS in the State of 
Montana. Montana has been implementing the de minimis level of 15 tons 
since 1998 as a state-approved rule, and ozone levels have remained 
relatively stable. EPA proposes to find that raising the federally 
enforceable de minimis level from zero to five tons will not interfere 
with compliance with the ozone NAAQS standards.
2. Carbon Monoxide
    The town of Billings, located in Yellowstone County, was designated 
nonattainment for the CO 8-hour NAAQS on March 3, 1978 (43 FR 9010) as 
a result of the 1977 CAA. Control plans were developed to bring 
Billings back into compliance following the nonattainment designation. 
The CO violation was attributed primarily to motor vehicle emissions 
(See TSD, pages 6 and 7.)
    The town of Missoula, in Missoula County, was designated as a 
nonattainment area for CO in 1978 because of repeated violations of the 
CO 8-hour NAAQS in 1977 and early 1978. Most of the problem focused on 
congested intersections and residential wood burning. Missoula took 
steps to reduce ambient levels of CO, including intersection changes, 
woodstove regulations, open burning regulations and the Federal motor 
vehicle emission reduction program. However, Missoula continued to 
violate the 8-hour CO NAAQS until 1992, when it was required to 
implement an oxygenated fuels program. Since the program began, 
Missoula has not recorded a violation of the 8-hour CO NAAQS (See TSD, 
Figure 4.)
    Between 1990 and 2000, CO emissions in the Missoula area decreased 
by 40%. The biggest reductions were from on-road motor vehicles and 
woodstoves. In 2000, these sources represented 95% of the CO emissions 
in the Missoula nonattainment area. The remaining sources, industry, 
natural gas combustion and railroads were responsible for less than 5% 
of CO emissions on a typical weekday (see 72 FR 46158; August 17, 
2007).
    In 72 FR 46158, EPA approved a request submitted by the State of 
Montana requesting to redesignate the Missoula ``moderate'' CO 
nonattainment area to attainment for the CO NAAQS. EPA also approved 
the new CO maintenance plan, which was submitted on May 27, 2005 and 
includes transportation conformity motor vehicle emission budgets 
(MVEB) for 2000, 2010, and 2020.
    The town of Great Falls, located in Cascade County, was designated 
nonattainment for CO on September 9, 1980 (45 FR 59315). This 
designation followed sixteen violations of the NAAQS 8-hour CO 
standard. Following the nonattainment designation, control plans were 
developed, but none were EPA approved. Great Falls was reevaluated in 
September 1990, based on the 1990 CAA Amendments and the lack of 
exceedances in the CO monitoring data for 1988 and 1989. On November 6, 
1991 (56 FR 56799), Great Falls was listed as a ``not classified'' 
nonattainment area for CO. Great Falls was re-designated as attainment 
on May 9, 2002 (67 FR 31143) (See TSD page 5 for more details and 
Figure 5 for Great Falls CO monitoring data).
    A review of CO monitoring data state-wide from 2002-2008 shows 
relatively constant levels of overall CO emissions and monitoring data 
shows that ambient CO levels remain well below the CO NAAQS (See TSD, 
Figure 5). None of the maintenance plans rely on Title 17, Chapter 8, 
subchapter 7 of the Montana Air Quality Program (MAQP) to attain and 
maintain the NAAQS, and CO levels in all three maintenance areas have 
fallen significantly over the years.
    Based on the minimal estimated increase in CO emissions due to the 
de minimis rule (See TSD pages 6-9 for basis and data), the relatively 
constant level of overall CO emissions, and monitoring data that shows 
that ambient CO levels remain well below the CO NAAQS, we propose to 
find that approving the de minimis rule would not interfere with 
continued attainment of the CO NAAQS in the State of Montana.
3. Particulate Matter (PM10)
    Based on the minimal estimated increase in PM emissions due to the 
de minimis rule (See TSD pages 9-27), the relatively constant level of 
overall PM10 emissions, and monitoring data that shows that 
ambient PM10 levels remain below the PM10 NAAQS, 
we propose to find that approving the de minimis rule would not 
interfere with continued attainment of the PM10 NAAQS in the 
State of Montana. Montana does not have any areas with monitoring data 
showing nonattainment for PM10. (For supplemental 
information concerning PM10 monitoring data, refer to TSD, 
pages 9-27.)
4. Particulate Matter (PM2.5)
    Monitoring results show that Montana is currently in attainment for 
the 1997

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and 2007 PM2.5 NAAQS (See TSD, Figures 16-18.) Libby, 
Lincoln County, is Montana's sole administratively designated 
PM2.5 nonattainment area (currently attaining the standard), 
that violated the 1997 annual standard. Montana does not have any other 
nonattainment areas for PM2.5.
    Based on the minimal estimated increase in PM2.5 
emissions due to the de minimis rule (See TSD pages 27-30 for basis and 
data), the relatively constant level of overall PM2.5 
emissions, and monitoring data that shows that ambient PM2.5 
levels remain below the 24-hour and annual NAAQS for both the 1997 
standard and the 2006 standard, we propose to find that approving the 
de minimis rule would not interfere with continued attainment of the 
PM2.5 NAAQS in the State of Montana.
5. Sulfur Dioxide
    The Billings/Laurel Federal Implementation Plan (73 FR 21418), and 
the portions of the Billings/Laurel SO2 Control Plan EPA 
approved, remain valid and enforceable, regardless of the existence of 
the de minimis rule. As such, we propose to find that approving the de 
minimis rule would not interfere with continued attainment of the 
SO2 NAAQS in the State of Montana (See TSD, pages 31-33 for 
basis and data.) Montana does not have any other nonattainment areas 
for SO2.
6. Nitrogen Dioxide
    Montana currently has no NO2 nonattainment areas; and 
consequently, no nonattainment area control plans with respect to 
NO2. Past monitoring of ambient NO2 reveals a 
history of exceedingly low concentrations (See TSD, Figures 20-22.) No 
discernable trend was observed during the monitoring period.
    MDEQ has installed monitoring equipment, including NO2 
monitors, in response to the increase in oil and gas development in the 
eastern part of the State and in anticipation of the recently proposed 
revision to the NO2 NAAQS (See TSD, Figure 22.) EPA 
strengthened the NO2 NAAQS in January 2010 by establishing a 
new 1-hr standard at 100 ppb (represented by the 3-yr average of the 
98th percentile from the annual distribution of daily max 1-hr 
averages) and retained the previous annual standard of 53 ppb.
    EPA proposes to find that the de minimis rule will not interfere 
with continued attainment of the NO2 NAAQS in the State of 
Montana, even in areas with increased oil and gas development.

ARM 17.8.743(1)(b)

    The May 28, 2003 SIP revision for ARM 17.8.743(1)(b) for asphalt 
concrete plants and mineral crushers reduces the stringency of the 
current SIP approved regulations. We commented that the State must 
provide an analysis showing that this new rule will not interfere with 
compliance with the NAAQS or PSD increments. Section 110(l) of the CAA 
states that EPA cannot approve a SIP revision that would interfere with 
any applicable requirement concerning attainment or reasonable further 
progress, as defined in section 171 of the CAA, or any other applicable 
requirement of the CAA. Montana did not provide any analysis or 
demonstration that the increased permit threshold for asphalt concrete 
plants and mineral crushers, from 5 tons per year to 15 tons per year, 
for any airborne pollutant, other than lead, regulated under Chapter 8 
of the ARM meets these criteria.
    EPA has concerns about a modification size cutoff (15 tons per 
year) that the State proposes as de minimis. Fifteen tons per year 
represents the major modification significance level for one criteria 
pollutant (PM10) and exceeds the significance level for 
another criteria pollutant (PM2.5) as well as for several 
non-criteria pollutants. It also exceeds the major source threshold for 
hazardous air pollutants (HAPs). Because of these reasons, EPA 
determines that the revision to ARM 17.8.743(1)(b) is not de minimis in 
the sense of having a trivial environmental effect. EPA has agreed in 
several rulemaking actions that certain activities with emissions of 5 
tons per year or less may be considered ``insignificant.'' However, EPA 
never before denoted emissions increases as high as 15 tons per year as 
de minimis. Since the State did not provide an analysis as to why 
emission increases as high as 15 tons per year should be considered as 
having a trivial environmental effect, EPA finds no basis for approving 
this revision. Therefore, EPA lacks sufficient available information to 
determine that the proposed SIP relaxation would not interfere with any 
applicable requirement concerning attainment and maintenance of the 
NAAQS, PSD increment, or any other requirement of the Act. If the State 
submits a new SIP with the analysis, we would evaluate such an 
analysis.

V. Summary of Proposed Actions

    Based on the above discussion, EPA proposes to find that the 
addition of new rule ARM 17.8.745 would not interfere with attainment 
or maintenance of any of the NAAQS in the State of Montana and would 
not interfere with any other applicable requirement of the Act (See TSD 
for basis); and thus, are approvable under CAA section 110(l). 
Therefore, we propose to approve ARM 17.8.745 as submitted on June 25, 
2010 by the State of Montana.
    We are proposing to approve new section ARM 17.8.745; and thus, we 
are also proposing to approve all references to ARM 17.8.745. This 
includes: The phrases in 17.8.740(8)(a) and (c), respectively, (1) 
``except when a permit is not required under ARM 17.8.745'' and (2) 
``except as provided in ARM 17.8.745'' and the phrase ``and 17.8.745'' 
in 17.8.743(1), submitted on May 28, 2003; and the phrase ``the 
emission increase meets the criteria in ARM 17.8.745 for a de minimis 
change not requiring a permit'' in 17.8.764(1)(b) and (4), submitted on 
May 28, 2003.
    EPA is proposing to disapprove the phrase ``asphalt concrete plants 
and mineral crushers'' in ARM 17.8.743(1)(b) submitted on May 28, 2003.

VI. 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 proposed 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);

[[Page 59344]]

     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, Carbon monoxide, 
Intergovernmental relations, Lead, Nitrogen dioxide, Ozone, Particulate 
matter, Reporting and recordkeeping requirements, Sulfur oxides, 
Volatile organic compounds, Incorporation by reference.

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

    Dated: September 16, 2011.
James B. Martin,
Regional Administrator, Region 8.
[FR Doc. 2011-24697 Filed 9-23-11; 8:45 am]
BILLING CODE 6560-50-P