Federal Register / Vol. 75, No. 177 / Tuesday, September 14, 2010 / Proposed Rules 55713 

Dated: September 8, 2010. 

Lisa Jackson, 

Administrator. 

[FR Doc. 2010–22851 Filed 9–13–10; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R08–OAR–2006–0952; FRL–9200–9] 

Air Quality Implementation Plans; 

Montana; Attainment Plan for Libby, 

MT PM2.5 Nonattainment Area and 

PM10 State Implementation Plan 

Revisions 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: EPA is proposing to approve 

the State Implementation Plan (SIP) 

revision submitted by the State of 

Montana on March 26, 2008. Montana 

submitted this SIP revision to meet 

Clean Air Act requirements for attaining 

the 15.0 micrograms per cubic meter 

(μg/m3) annual fine Particulate Matter 

(PM2.5) national ambient air quality 

standard (NAAQS) for the Libby 

nonattainment area. The plan, herein 

called an ‘‘attainment plan,’’ includes an 

attainment demonstration, an analysis 

of Reasonably Available Control 

Technology and Reasonably Available 

Control Measures (RACT/RACM), baseyear and projection year emission 

inventories, and contingency measures. 

The requirement for a Reasonable 

Further Progress (RFP) plan is satisfied 

because Montana projects that 

attainment with the 1997 PM2.5 NAAQS 

will occur in the Libby nonattainment 

area by April 2010. In addition, we are 

proposing to approve the PM10 SIP 

revisions to the Lincoln County Air 

Pollution Control Program submitted by 

Montana on June 26, 2006 for inclusion 

into Libby’s attainment plan. This 

submittal contains provisions, including 

contingency measures, for controlling 

both PM10 and PM2.5 emissions from 

woodstoves, road dust, and outdoor 

burning. Finally, EPA is proposing to 

find on-road directly emitted PM2.5 and 

oxides of nitrogen (NOX) in the Libby, 

Montana nonattainment area 

insignificant for regional transportation 

conformity purposes. If this 

insignificance finding is finalized as 

proposed, the Libby, Montana 

nonattainment area will not have to 

perform a regional emissions analysis 

for either direct PM2.5 or NOX as part of 

future conformity determinations for the 

annual 1997 PM2.5 NAAQS. 

DATES: Written comments must be 

received on or before October 14, 2010. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R08– 

OAR–2006–0952, by one of the 

following methods: 

• http://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 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 St., Denver, 

Colorado 80202–1129. 

• Hand Delivery: Callie Videtich, 

Director, Air Program, Environmental 

Protection Agency (EPA), Region 8, Mail 

Code 8P–AR, 1595 Wynkoop St., 

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–2006– 

0952. 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 St., Denver, Colorado 

80202–1129. EPA requests that, if at all 

possible, you contact the individual 

listed in FOR FURTHER INFORMATION

CONTACT 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, 

Environmental Protection Agency 

(EPA), Region 8, Mailcode 8P–AR, 1595 

Wynkoop Street, Denver, Colorado 

80202–1129, Phone: (303) 312–6602, 

Fax: (303) 312–6064, 

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. 

(iv) The initials PM2.5 mean or refer to 

particulate matter with an aerodynamic 

diameter of less than 2.5 micrometers. 

(v) The initials PM10 mean or refer to 

particulate matter with an aerodynamic 

diameter of less than 10 micrometers. 

(vi) The word State or Montana refers 

to the State of Montana unless the 

context indicates otherwise. 

(vii) The initials NAAQS mean or 

refer to National Ambient Air Quality 

Standards. 


emcdonald on DSK2BSOYB1PROD with PROPOSALS
55714 Federal Register / Vol. 75, No. 177 / Tuesday, September 14, 2010 / Proposed Rules 

Table of Contents 

I. General Information 

II. What Action Is EPA Proposing? 

III. What Is the Background for EPA’s 

Proposed Action? 

A. Designation History 

B. Clean Air Fine Particle Implementation 

Rule 

IV. What Is Included in Montana’s Submittal? 

A. Background 

B. PM10 SIP Revisions to the Lincoln 

County Air Pollution Control Program 

C. Libby and Vicinity PM2.5 Control Plan 

V. EPA’s Analysis of Montana’s Submittal 

A. PM10 SIP Revisions to Lincoln County 

Air Pollution Control Program 

B. Attainment Demonstration 

C. Analysis of Montana’s Submittal 

1. Pollutants Addressed and Attainment 

Date 

2. Monitoring Data 

3. Emission Inventory 

4. Modeling 

5. RACT/RACM 

6. Contingency Measures 

7. Transportation Conformity 

Requirements 

VI. Proposed Action 

VII. Statutory and Executive Order Reviews 

I. General Information 

A. What should I consider as I prepare 

my comments for EPA? 

1. Submitting CBI. Do not submit this 

information to EPA through http:// 

www.regulations.gov or e-mail. Clearly 

mark the part or all of the information 

that you claim to be CBI. For CBI 

information in a disk or CD ROM that 

you mail to EPA, mark the outside of the 

disk or CD ROM as CBI and then 

identify electronically within the disk or 

CD ROM the specific information that is 

claimed as CBI. In addition to one 

complete version of the comment that 

includes information claimed as CBI, a 

copy of the comment that does not 

contain the information claimed as CBI 

must be submitted for inclusion in the 

public docket. Information so marked 

will not be disclosed except in 

accordance with procedures set forth in 

40 CFR part 2. 

2. Tips for Preparing Your Comments. 

When submitting comments, remember 

to: 

a. Identify the rulemaking by docket 

number and other identifying 

information (subject heading, Federal 

Register date and page number). 

b. Follow directions—The agency may 

ask you to respond to specific questions 

or organize comments by referencing a 

Code of Federal Regulations (CFR) part 

or section number. 

c. Explain why you agree or disagree; 

suggest alternatives and substitute 

language for your requested changes. 

d. Describe any assumptions and 

provide any technical information and/ 

or data that you used. 

e. If you estimate potential costs or 

burdens, explain how you arrived at 

your estimate in sufficient detail to 

allow for it to be reproduced. 

f. Provide specific examples to 

illustrate your concerns, and suggest 

alternatives. 

g. Explain your views as clearly as 

possible, avoiding the use of profanity 

or personal threats. 

h. Make sure to submit your 

comments by the comment period 

deadline identified. 

II. What action is EPA proposing? 

EPA is proposing to approve two 

Montana SIP submittals for the Libby 

nonattainment area: (1) PM10 SIP 

revisions to the Lincoln County Air 

Pollution Control Program submitted by 

Montana on June 26, 2006; and (2) the 

Libby PM2.5 attainment plan submitted 

by Montana on March 26, 2008. EPA has 

determined that the PM10 SIP revisions 

and the PM2.5 attainment plan meet 

applicable requirements of the Clean Air 

Act, including the Clean Air Fine 

Particle Implementation Rule (herein 

referred to as the implementation rule) 

issued by EPA on April 25, 2007 (72 FR 

20586). Furthermore, EPA has 

determined that Montana’s PM2.5 SIP 

submittal for the Libby area includes an 

attainment demonstration, an analysis 

of RACT/RACM, base-year and 

projection-year emission inventories 

and contingency measures. The 

attainment plan supports a 

determination that the Libby PM2.5

nonattainment area will attain the 1997 

PM2.5 NAAQS by the April 2010 

deadline for attainment. Finally, EPA is 

proposing to find on-road directly 

emitted PM2.5 and NOX in the Libby, 

Montana nonattainment area 

insignificant for regional transportation 

conformity purposes. 

EPA’s analysis and findings are 

discussed in this proposed rulemaking. 

Additional technical support documents 

are available at http:// 

www.regulations.gov, Docket No. EPA– 

R08–OAR–2006–0952. 

III. What is the background for EPA’s 

proposed action? 

A. Designation History 

On July 18, 1997 (62 FR 38652), EPA 

established PM2.5 NAAQS, including an 

annual standard of 15.0 μg/m3 based on 

a 3-year average of annual mean PM2.5

concentrations, and a 24-hour (or daily) 

standard of 65 μg/m3 based on a 3-year 

average of the 98th percentile of 24-hour 

concentrations. EPA established the 

standards based on significant evidence 

and numerous health studies 

demonstrating that serious health effects 

are associated with exposures to PM2.5. 

Following promulgation of a new or 

revised NAAQS, EPA is required by the 

CAA to designate areas throughout the 

United States as attaining or not 

attaining the NAAQS; this designation 

process is described in section 107(d)(1) 

of the CAA. In 1999, EPA and state air 

quality agencies initiated the monitoring 

process for the 1997 PM2.5 NAAQS, and, 

by January 2001, established a complete 

set of air quality monitors. On January 

5, 2005, EPA published initial air 

quality designations for the 1997 PM2.5

NAAQS (70 FR 944), based on air 

quality monitoring data for calendar 

years 2001–2003. On April 14, 2005, 

EPA published a final supplemental 

rule amending the agency’s initial 

designations (70 FR 19844). EPA did not 

consider modifications made in this rule 

to be ‘‘re-designations’’ because the 

changes were made before April 5, 2005, 

the effective date of the initial 

designations. As a result of the final 

supplemental rule, PM2.5 nonattainment 

designations are in effect for 39 areas, 

comprising 208 counties within 20 

states (and the District of Columbia) 

nationwide, with a combined 

population of about 88 million people. 

The Libby nonattainment area which is 

the subject of this rulemaking is 

included in the list of areas not attaining 

the 1997 PM2.5 NAAQS. 

On October 17, 2006, EPA 

strengthened the 24-hour PM2.5 NAAQS 

to 35 μg/m3 and retained the level of the 

annual PM2.5 standard at 15.0 μg/m3 (71 

FR 61144). On November 13, 2009 EPA 

designated areas as either attainment/ 

unclassified or nonattainment with 

respect to the revised 24-hour NAAQS 

(74 FR 58688). In the November 2009 

designation action, EPA established a 

deadline of December 14, 2012 for states 

to submit attainment plans for areas 

designated as nonattainment for the 

revised 24-hour PM2.5 NAAQS. 

Of relevance to the proposed 

rulemaking herein, the notice for the 

November 2009 action clarified 

designations for the 1997 PM2.5 NAAQS 

by relabeling the existing designation 

tables to identify designations for the 

annual NAAQS, and by providing a 

separate table identifying designations 

for the 1997 24-hour NAAQS (i.e., 65 

μlg/m3). In that table, the Libby 

nonattainment area is designated as 

attaining the 1997 24-hour PM2.5

NAAQS. 


emcdonald on DSK2BSOYB1PROD with PROPOSALS
Federal Register / Vol. 75, No. 177 / Tuesday, September 14, 2010 / Proposed Rules 55715 

1Subpart 1 applies to nonattainment areas 

generally. 

B. Clean Air Fine Particle 

Implementation Rule 

On April 25, 2007, EPA issued the 

Clean Air Fine Particle Implementation 

Rule for the 1997 PM2.5 NAAQS (72 FR 

20586). The implementation rule 

describes the CAA framework and 

requirements for developing state PM2.5

attainment plans. An attainment plan 

must include a demonstration that a 

nonattainment area will meet applicable 

NAAQS within the timeframe provided 

in the statute. This demonstration must 

include modeling (40 CFR 51.1007) that 

is performed in accordance with EPA 

modeling guidance (EPA–454/B–07– 

002, April 2007). It must also include 

supporting technical analyses and 

descriptions of all relevant adopted 

federal, state, and local regulations and 

control measures that have been 

implemented by the proposed 

attainment date. 

For the 1997 PM2.5 NAAQS, an 

attainment plan must show that a 

nonattainment area will attain the 

standard by 2010. Alternatively, if the 

area is not expected to meet the NAAQS 

by 2010, a state may propose an 

attainment-date extension for up to five 

years based on the severity of the 

nonattainment problem and on the 

availability and feasibility of pollution 

control measures (CAA section 

172(a)(2)). 

For each nonattainment area, the state 

must demonstrate that it has adopted all 

RACT/RACM needed to show that the 

area will attain the PM2.5 standards ‘‘as 

expeditiously as practicable.’’ The 

implementation rule provided guidance 

for making these RACM and RACT 

determinations (72 FR 20616–21). Any 

measures that are necessary to meet 

these requirements which are not 

already either federally promulgated or 

part of the state’s SIP must be submitted 

in enforceable form as part of a state’s 

attainment plan. 

The implementation rule also 

included policies on pollutants that 

comprise total PM2.5. Five main types of 

pollutants contribute to fine particle 

concentrations: direct PM2.5, sulfur 

dioxide (SO2), nitrogen oxides (NOX), 

ammonia, and volatile organic 

compounds (VOCs). All but direct PM2.5

is considered to be ‘‘precursors’’ to PM2.5

formation. The effect of reducing 

emissions of each of these five types of 

pollutants varies by area, depending on 

PM2.5 composition, emission levels, and 

other area-specific factors. For this 

reason, the implementation rule 

established policies regarding what 

states should include in their PM2.5

attainment plans for evaluating these 

pollutants. 

Under these policies, sources of direct 

PM2.5 emissions (including organic 

particles, elemental carbon and 

inorganic particles) and SO2 must be 

evaluated for emission reduction 

measures in all PM2.5 nonattainment 

areas. Sources of NOX must be evaluated 

for emission reduction measures in each 

area unless the state and EPA 

demonstrate that NOX is not a 

significant contributor to PM2.5

concentrations in a specific area. 

Neither VOC nor ammonia sources are 

required to be evaluated for emission 

reduction measures in an area unless 

the state or EPA demonstrates that 

either of these pollutant types 

significantly contributes to PM2.5

concentrations. To reverse any of the 

presumptive precursor policies, the 

implementation rule provided guidance 

on the types of analyses that may be 

included in a technical demonstration. 

The implementation rule also 

provided guidance on other elements of 

a state’s attainment plan, including but 

not limited to, consideration of emission 

inventories, contingency measures, and 

motor vehicle emissions budgets used 

for transportation conformity purposes. 

IV. What is included in Montana’s 

submittal? 

A. Background 

Libby, Montana, a small rural 

community, is located in Lincoln 

County in the northwestern part of the 

State. Libby sits in the narrow, 

triangular Kootenai valley at an 

elevation of 2,100 feet. The 

nonattainment area is dominated by 

three major mountain ranges that limit 

the air-shed: (1) The Rocky Mountain 

and Flathead Ranges on the eastern 

boundary; (2) the Purcell Range, which 

roughly bisects the area from north to 

south; and (3) the Selkirk and Cabinet 

Ranges on the western boundary. The 

vast majority of the area surrounding 

Libby is National Forest managed by the 

U.S. Forest Service. Based on the 2000 

census and a growth rate through 2005 

of 3.71%, Libby’s population is 

estimated at 2,674. 

The highest PM2.5 concentrations in 

Libby generally occur during the winter 

months of November through February. 

The winter concentrations are related to 

stagnant weather conditions dominated 

by light winds and strong temperature 

inversions. These meteorological 

conditions can trap emissions within 

the valley for many days or weeks. 

Air quality data recorded during 

2001–2003 at the PM2.5 monitor at the 

Libby Courthouse Annex showed 

violations of the annual PM2.5 standard. 

Libby was designated nonattainment for 

PM2.5 under section 107(d)(3) of the 

CAA, on April 5, 2005 (40 CFR part 81). 

The air quality planning requirements 

for PM2.5 nonattainment areas are set out 

in Title I subpart 1 of the Act.1

Historically, Libby was designated 

nonattainment for PM10 by operation of 

law on November 15, 1990 (56 FR 

56694, 56794, November 6, 1991), under 

CAA section 107(d)(4)(B) and was 

classified as ‘‘Moderate.’’ The PM10

attainment plan was approved by EPA 

on August 30, 1994 (59 FR 44627). 

Montana has submitted revisions to the 

Lincoln County Air Pollution Control 

Program (herein referred to as the 

Program) and the Libby and Vicinity 

PM2.5 Control Plan (herein referred to as 

the Libby attainment plan) for the 

purpose of demonstrating attainment of 

the annual PM2.5 NAAQS. After public 

notice, public hearings regarding these 

two submittals were held on February 

27, 2006 for the Lincoln County Air 

Pollution Control Program and on 

March 25, 2008 for the Libby and 

Vicinity PM2.5 Control Plan. The 

Montana Board of Environmental 

Review approved the revised Lincoln 

County Air Pollution Control Program 

on March 23, 2006 and the Libby 

attainment plan on March 25, 2008. 

Montana has met the requirements of 

Section 110(a)(2) for reasonable notice 

and public hearings. 

B. PM10 SIP Revisions to the Lincoln 

County Air Pollution Control Program 

Montana submitted revisions to the 

PM10 SIP for the Lincoln County Air 

Pollution Control Program for the Libby 

nonattainment area to improve and 

strengthen the PM10 attainment plan. 

The revisions include several provisions 

to regulate solid fuel burning devices 

and require owners and operators to 

obtain operating permits. Operating 

permits may only be issued for EPAcertified woodstoves or for pellet stoves. 

Furthermore, only specified materials 

can be burned in these devices, and 

visible emissions of greater than 20% 

opacity from them are prohibited. 

Additionally, these provisions allow for 

air pollution alerts if PM10 or PM2.5

concentrations averaged over a 4-hour 

period exceed a level 20 percent below 

any federal or state particulate matter 

standard. Provisions are also included 

for penalties for non-compliance and 

contingency measures. 

Additionally, revisions were made for 

open and outdoor burning regarding 

prohibited materials, major open 

burning and management burning, 

minor open burning or residential open 


emcdonald on DSK2BSOYB1PROD with PROPOSALS
55716 Federal Register / Vol. 75, No. 177 / Tuesday, September 14, 2010 / Proposed Rules 

2The boundaries of the District are identical to 

those for the nonattainment area. 

3Ward, T.J., Rinehart, L.R., Lange, T. The 2003/ 

2004 Libby, Montana PM2.5 Source Apportionment 

Research Study. Aerosol Science and Technology. 

Vol. 40:166–177. 2006. 

4 Ibid. 

burning, and special burning. These 

revisions generally included significant 

limits on the time periods for open 

burning activities as compared to the 

existing PM10 SIP. Further restrictions 

also include prohibitions on burning 

from November 1 to March 31, which is 

the winter-time period when 

exceedances of PM2.5 typically occur. 

Lincoln County’s Program prohibits 

burning the same materials as the State 

but is more restrictive because the 

burning of trade waste, Christmas tree 

waste, leaves, grass clippings and 

stumps is prohibited within the Air 

Pollution Control District 2 (herein 

referred to as the District). The June 26, 

2006 submittal also included a 

stringency analysis for the Program 

showing that the revisions are more 

stringent than comparable State law. 

C. Libby and Vicinity PM2.5 Control Plan 

The Libby attainment plan provides a 

demonstration that the annual PM2.5

NAAQS will be met by April 2010 

through the implementation of the 

Lincoln County Program described in 

section B above. The Libby attainment 

plan includes an emissions inventory 

(EI), a woodstove air pollution control 

calculation, and a technical analysis 

showing that the emissions of PM2.5 will 

be reduced sufficiently to meet the 

NAAQS. The key components of the 

Libby attainment plan are described as 

follows: 

1. Ambient air quality monitoring in 

the Libby area began in 1999 and is 

conducted using Federal Reference 

Method (FRM) PM2.5 samplers at the 

Courthouse Annex site in downtown 

Libby. Based on monitoring data from 

the years 2001 to 2003, the 3-year 

annual design value was 15.9 μg/m3, 

which is a violation of the annual PM2.5

NAAQS. In February 2002, speciation 

monitoring was conducted to determine 

possible PM2.5 emission sources. The 

results identified organic carbon as the 

main component of wintertime PM2.5

emissions. Further ambient monitoring 

was conducted from November 2003 to 

February 2004 to determine the 

geographic distribution of PM2.5

concentrations. After additional 

monitoring from various locations 

beyond Libby city limits and 

meteorological data from Libby 

Courthouse Annex site, it was 

determined that the Libby Courthouse 

Annex site represented the worst-case 

ambient PM2.5 levels in the area. 

2. A chemical mass balance study 

(CMB) was conducted during the winter 

of 2003–2004 by the University of 

Montana, Center for Environmental 

Health Sciences (UM–CEHS). The goal 

of the CMB study was to identify those 

emission sources in the Libby area that 

contributed to elevated PM2.5

concentrations. The CMB model runs 

indicated that emissions from 

residential wood combustion were the 

major source of the fine particles on the 

PM2.5 filters, averaging 82% during the 

CMB study period (i.e., winter months). 

Other contributing PM2.5 sources 

identified by the CMB model were 

automobile exhaust (7%), ammonium 

nitrate (5%), diesel exhaust (4%), and 

sulfate (2%).3

3. Carbon 14 (14C) analysis, as a part 

of the CMB study completed by UM– 

CEHS, was conducted by the University 

of Arizona’s Accelerator Mass 

Spectrometry Laboratory Facility to 

provide further evidence that wood 

combustion was the major source of 

PM2.5 emissions in Libby.4

4. The Libby base year PM2.5 EI 

included a quantification of actual PM2.5

emissions and apportioned the 

emissions on a seasonal and annual 

basis for point and area sources. The 

State used calendar year 2005 as the 

base year for the development of an EI 

for the Libby area. The EI was used to 

support a proportional rollback model 

for the emission control plan. The State 

developed information for 2005 that 

allowed for the calculation of residential 

wood combustion and commercial fuel 

use. 

5. The Libby PM10 SIP as revised also 

serves as the control plan for emissions 

of PM2.5. Controls exist for reducing 

emissions from re-entrained road dust 

through aggressive street sweeping and 

flushing, and traction sand durability 

requirements. Emissions of organic 

carbon are controlled through 

residential woodstove regulations and 

outdoor burning restrictions. 

6. A significant part of the PM2.5

control strategies has been the 

completion of a woodstove changeout 

program. Approximately 1,130 

uncertified woodstoves were replaced 

with EPA-certified woodstoves or pellet 

fuel burning devices. After the 

changeout, PM2.5 emissions have been 

reduced from approximately 138.78 

tons/year to 57.21 tons/year, a decrease 

of 59%. 

PM2.5 control strategies are primarily 

focused on residential wood 

combustion. The control strategies also 

include: air pollution alerts may be 

declared during the winter months; 

solid fuel burning devices must have an 

operating permit; only EPA-certified 

woodstoves and pellet fuel burning 

devices can obtain permits; and only 

permitted pellet fuel devices can 

operate during air pollution alerts. 

Other control strategies for PM2.5 have 

included an expanded area for the 

prescribed burning control program and 

the continuing federal tailpipe 

standards. 

7. Analysis for RACT/RACM was 

conducted for the Libby area. EPA’s 

RACT/RACM guidance covers three 

general source categories: stationary, 

mobile and area (79 FR 20586). The 

Libby PM2.5 CMB study did not identify 

any emissions from local stationary 

sources, only a minor amount from 

mobile sources, and a significant 

amount from an area source category— 

residential wood combustion. EPA’s 

area source RACM guidance covers four 

source categories: (1) Reduced solvent 

usage or solvent substitution; (2) 

controls on charbroiling or other 

commercial cooking operations; (3) 

controls on woodstoves and fireplaces; 

and (4) new or improved regulations on 

open burning (79 FR 20586 and 20621). 

The Libby attainment plan concluded 

that wood combustion control strategies 

and more stringent rules on open 

burning constituted RACM for area 

sources. The analysis further noted that 

the other two categories of area sources, 

commercial users of solvent and 

commercial cooking, were infrequent in 

the Libby area. The analysis also 

considered mobile sources, but 

determined that in light of their small 

contribution to PM2.5 nonattainment, 

existing federal tailpipe standards and 

natural turnover rates of the local 

vehicle fleet made additional measures 

for mobile sources unnecessary. 

8. The Lincoln County Air Pollution 

Control Program is legally enforceable 

by Lincoln County, and by the State 

should Lincoln County fail to 

administer the program. The Libby 

attainment plan also provides for 

contingency measures if the NAAQS are 

exceeded after implementation. There is 

one contingency measure for wood 

burning for space heating purposes if it 

is determined that wood burning 

emissions contribute to an exceedance 

of the PM2.5 NAAQS, then only biomass 

pellet fuel burners may operate within 

the District. Other contingency 

measures are included for re-entrained 

dust and industrial facilities. There is 

also a review process to consider 

permanent adoption of a contingency 

measure. 


emcdonald on DSK2BSOYB1PROD with PROPOSALS
Federal Register / Vol. 75, No. 177 / Tuesday, September 14, 2010 / Proposed Rules 55717 

V. EPA’s Analysis of Montana’s 

Submittal 

A. PM10 SIP Revisions to Lincoln County 

Air Pollution Control Program 

EPA’s summary of the PM10 SIP 

revisions is addressed in detail under 

section IV.B. These revisions were made 

for two purposes: (1) To address PM2.5

attainment plan requirements; and (2) to 

improve and strengthen requirements 

for continued attainment of PM10. The 

revisions are a significant improvement 

to a plan that was approved by EPA 16 

years ago. The Libby area has not had 

an exceedance of the PM10 NAAQS 

since 1993. Furthermore, clarifications 

were made to the language to better 

explain to the public the requirements 

of the air quality program. The revisions 

removed exemptions and replaced them 

with requirements for obtaining permits 

for wood burning appliances. These 

revisions also added enforcement 

provisions where previously none had 

existed. 

Section 110(l) of the Clean Air Act 

states that a SIP revision cannot be 

approved if the revision would interfere 

with any applicable requirement 

concerning attainment and reasonable 

further progress toward attainment of 

the NAAQS or any other applicable 

requirement of the Act. The Libby area 

is currently meeting the NAAQS for all 

criteria pollutants and has not had any 

violations of the PM10 standard for over 

a decade. Furthermore, the revisions do 

not relax the stringency of any SIP 

provision; in fact, the revisions 

generally strengthen the SIP. As a result, 

the PM10 SIP revisions do not interfere 

with attainment of the NAAQS or any 

other applicable requirement of the Act. 

Therefore, section 110(l) requirements 

are satisfied. 

B. Attainment Demonstration 

In accordance with section 172(c) of 

the CAA and the implementation rule, 

the attainment plan submitted by 

Montana for the Libby area included: (1) 

Emission inventories for the plan’s base 

year (2005) and projection year (2009); 

and (2) an attainment demonstration 

consisting of: (a) Technical analyses that 

locate, identify, and quantify sources of 

emissions contributing to violations of 

the annual PM2.5 NAAQS; (b) analyses 

of future-year emission reductions and 

air quality improvements expected to 

result from national and local programs, 

and from new measures to meet RACT/ 

RACM requirements; (c) adopted 

emission reduction measures; and (d) 

contingency measures. 

C. Analysis of Montana’s Submittals 

1. Pollutants Addressed and Attainment 

Date 

In accordance with policies described 

in the implementation rule, Montana’s 

PM2.5 attainment plan evaluates 

emissions of direct PM2.5, SO2 and NOX

in the Libby area. Montana provided 

documentation of expeditious 

attainment of the annual PM2.5 NAAQS 

in the Libby area by April 2010. Areas 

that demonstrate attainment by 2010 are 

considered to have satisfied the 

requirement to show reasonable further 

progress toward attainment and need 

not submit a separate RFP plan. For 

similar reasons such areas are also not 

subject to a requirement for a midcourse review. 

Montana’s evaluation of emissions is 

based on the work conducted by UM– 

CEHS for the CMB model runs 

indicating that emissions from 

residential wood combustion were the 

major source (82%) of the fine particles 

on the PM2.5 filters. Other PM2.5 sources 

identified by the CMB model were 

automobile exhaust (7%), ammonium 

nitrate (5%), diesel exhaust (4%), and 

sulfate (2%). In addition, a Carbon 14 

analysis confirmed that wood 

combustion is the major source of PM2.5

emissions in the Libby area and that 

emissions of both SO2 and NOX are very 

minor compared to PM2.5 emissions 

from residential wood combustion. As 

described in the emissions inventory, 

the sources of SO2 are from home 

heating oil and sources of NOX are from 

on-road and off-road mobile sources (see 

further discussion in section V.C.7. on 

NOX emissions from mobile sources). 

2. Monitoring Data 

As shown in the table below, the 

annual weighted average for 2009 shows 

that the Libby area has met the April 

2010 deadline for the 1997 PM2.5

NAAQS. The trend in annual average 

concentrations is downward and 

coincides with the implementation of 

the woodstove changeout program. This 

is based on quality-controlled and 

quality-assured monitoring data from 

2005–2009 that is available in the EPA 

Air Quality System (AQS). 

TABLE V.2–1 

Year Annual weighted average 

(μg/m3) 

2005 ............ 15.8 

2006 ............ 15.2 

2007 ............ 13.0 

2008 ............ 12.9 

2009 ............ 10.7 

3. Emission Inventory 

CAA section 172(c)(3) states that for 

nonattainment areas, the State shall 

prepare a statewide emission inventory 

no later than three years after 

designation. The baseline emission 

inventory for calendar year 2005 or 

another suitable year shall be used for 

attainment planning (40 CFR 

51.1008(b)). EPA promulgated the Air 

Emissions Reporting Rule (AERR) (40 

CFR part 51, subpart A) in order to 

consolidate the various reporting 

requirements that already exist, 

including those requirements outlined 

in the PM2.5 implementation rule. The 

AERR requires states to report statewide emissions every three years. 

Montana prepared a statewide emission 

inventory for 2005. This inventory 

included annual totals of emissions of 

criteria pollutants and their precursors. 

The State used data from this statewide 

inventory to create an emission 

inventory specific to the Libby area. 

Monitoring data for 2005 showed an 

exceedance of the PM2.5 annual 

standard. The year 2005 is a suitable 

year for attainment planning because an 

emission inventory for this year is 

representative of ambient emission 

levels that led to the exceedance of the 

annual standard. The 2005 emission 

inventory showed that residential wood 

burning comprised 82% of the direct 

PM2.5 emissions during the winter. The 

next largest direct source, road dust, 

was 11%, followed by locomotive 

emissions at 3.4%. The remaining 

criteria pollutant emissions were very 

minor, including the precursors of PM2.5

(i.e., NOX and SO2). Background values 

of PM2.5 were accounted for by the State 

using monitored data collected at 

remote stations far away from emissions 

sources in the Libby area. EPA notes 

that the State used a conservative 

emission inventory approach for 

projecting future growth for the 2010 

attainment year which involved 

increasing the vehicle emissions by 

2.1% (the population growth rate) from 

the 2005 base year inventory, and not 

taking any credit for potential emission 

reductions that may have been available 

from fleet turnover and the Federal 

tailpipe standards for vehicles. 

Condensable particulate matter was not 

considered in the emission inventory 

because of a lack of sources in the Libby 

area. 

4. Modeling 

CAA Section 172(c) requires states 

with nonattainment areas to submit an 

attainment demonstration. A PM2.5

attainment demonstration consists of (1) 

analyses which estimate whether 


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selected emissions reductions will 

result in ambient concentrations that 

meet the NAAQS and (2) a set of control 

measures which will result in the 

required emissions reductions. 

Montana’s analysis of future-year 

emissions reductions and air quality 

improvements was based on a 

proportional rollback model for showing 

attainment of the standard and a roll 

forward model demonstrating 

attainment in the future. The 

proportional models were applied in 

conjunction with the findings from 

chemical mass balance and Carbon 14 

studies conducted by the University of 

Montana. 

In the particular case of Libby, a 

proportional model is more appropriate 

than dispersion models. The great 

majority of periods with elevated PM2.5

concentrations in Libby occur during 

wintertime stagnation conditions. 

Furthermore, dispersion in Libby is 

constrained by steep terrain. The most 

suitable approach for stagnation 

conditions should be determined on a 

case-by-case basis, (see sections 7.2.8 

and 8.3.4.2(b) of the Guideline on Air 

Quality Models, 40 CFR part 51, 

appendix W), and an alternative model 

should be selected by the EPA Regional 

Office when a preferred model is less 

appropriate (see section 3.2.2 of the 

Guideline). 

The proportional model used the 

emission inventory for 2005 when there 

was an exceedance of the standard. The 

decrease in PM2.5 emissions for the 

Libby area resulting from the woodstove 

changeout program was calculated 

based on the amount of wood burned by 

the EPA-certified woodstoves and then 

compared to the amount of emissions 

resulting from burning the same amount 

of wood from the uncertified 

woodstoves that were still in use. The 

decrease in emissions would be an 

indication of the effectiveness of the 

control strategy. Montana estimated that 

PM2.5 emissions would be reduced by 

81.57 tons as a result of the new EPAcertified woodstoves installed in Libby 

households. 

The State projected future annual 

average PM2.5 concentrations for Libby 

at 9.5 μg/m3. This projection was based 

on the installation of the new stoves and 

a 100 percent compliance with the 

wood burning restrictions for Libby. 

EPA’s guidance is based on emission 

sources complying with state and local 

restrictions on emission sources 

(Emissions Inventory Guidance for 

Implementation of Ozone and 

Particulate Matter National Ambient Air 

Quality Standards (NAAQS) and 

Regional Haze Regulations, appendix B, 

EPA–454/R–05–001, August 2005.) The 

guidance defines rule effectiveness (RE) 

as a method to account for the reality 

that not all emission sources are in 

compliance 100% of the time. 

The guidance provides a listing of the 

factors that are most likely to affect RE. 

EPA used a conservative 70% RE 

instead of a 100 percent compliance to 

determine if Libby would still reach 

attainment of the PM2.5 standard. EPA 

estimated that using the more 

conservative compliance percentage for 

wood burning restrictions, the future 

value for Libby would still be below the 

PM2.5 standard of 15 μg/m3. As stated 

above in Table V.2.–1 the Libby area 

2009 annual average is currently 10.7 

μg/m3. 

5. RACT/RACM 

Determination of RACT/RACM is a 

three-step process: (1) Identifying 

potential measures that are reasonable; 

(2) modeling to identify the attainment 

date that is as expeditious as 

practicable; and (3) selecting RACT/ 

RACM. Identification of potential 

measures should ordinarily be 

supported by an inventory of emissions 

of directly emitted PM2.5 and of 

precursors from the relevant sources 

and source categories; the 

technologically feasible control 

measures for each source or source 

category; and, for each measure, the 

control efficiency, possible emission 

reductions by pollutant, estimated cost 

per ton, and the date by which the 

measure was or could be implemented; 

and other relevant information. 

For the first step, identification of 

potential measures that are reasonable, 

Montana supported its RACT/RACM 

analysis with the emissions inventory 

and the CMB study. The RACT/RACM 

analysis first noted that there are no 

major stationary sources of PM2.5 in the 

Libby area. It also noted that minor 

stationary sources are currently 

regulated under Montana’s minor source 

program, which requires permits and a 

Best Available Control Technology 

(BACT) review. As discussed in the 

implementation rule, if state or federal 

rules already regulate a given sector, it 

is reasonable for a state to look to 

unregulated sectors for RACT/RACM 

measures. Furthermore, the 

implementation rule permits the state to 

use reason in the extent of its effort to 

identify potential control measures. For 

example, the rigor of the analysis may 

depend on the relative contribution of a 

particular pollutant to the PM2.5

nonattainment problem (72 FR 20613). 

As shown by the CMB study, stationary 

sources are a very minor contributor to 

PM2.5 nonattainment in Libby. 

Similarly, the RACT/RACM analysis 

reasoned that mobile sources are 

currently regulated, make only a minor 

contribution to the nonattainment 

problem, and the overall emissions will 

continue to be reduced through fleet 

turnover. Thus, the first step focused on 

measures for area sources. 

The analysis further noted that two 

types of area sources (commercial users 

of solvents and commercial charbroilers 

or other commercial cooking operations) 

were infrequent in the Libby area. The 

analysis also discussed re-entrained 

road dust, which the CMB study did not 

identify as a contributor to PM2.5

nonattainment, and noted that there 

were existing SIP provisions to control 

road dust. As to home heating oil, a 

source of SO2, the CMB study found 

only a 2% contribution to PM2.5

nonattainment for all sulfates combined. 

Thus, the RACM analyses focused on 

the remaining area sources of wood 

burning devices and open burning and 

identified several control measures to be 

included in the attainment plan. 

For the second step, as discussed in 

more detail in section V.C.4, Montana 

modeled attainment by 2010 based on 

adoption of these reasonable control 

measures. Finally, for the third step, 

based on the analysis, Montana selected 

and adopted RACM for wood burning 

devices and open burning. For wood 

burning devices, the State developed 

and implemented a woodstove 

changeout control strategy. The 

woodstove changeout permanently 

removed 1,130 old, uncertified 

woodstoves and replaced them with 

EPA-certified woodstoves or pellet 

stoves. Additionally, the State adopted 

measures that require permits for solid 

fuel burning devices (including 

woodstoves) and restrict installation 

and operation of these devices to three 

categories: pellet stoves, devices with a 

catalytic emissions control system, and 

devices with a non-catalytic emissions 

control system. For the latter two, 

emission limits are imposed. 

RACM measures were also included 

for major open burning, management 

burning, residential burning, and 

special burning. The PM2.5 attainment 

plan includes BACT and permits for an 

expanded area, which is the entire Air 

Pollution Control District, for all of 

these different types of burning 

activities. Additionally, these burning 

activities were restricted to shorter time 

periods. 

In summary, the State evaluated, by 

source category, sources of direct PM2.5, 

SO2 and NOX for RACT/RACM control 

measures. The State’s evaluation of 

sources of SO2 and NOX resulted in 

their decision that no additional 

controls are necessary to attain the 


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NAAQS based on the absence of major 

sources or area sources that can be cost 

effectively or reasonably controlled. The 

State therefore adopted RACM for direct 

PM2.5. In accordance with Section 172(c) 

of the CAA, Montana has adopted all 

RACT/RACM needed to attain the 

standards as expeditiously as 

practicable. EPA has reviewed 

Montana’s RACT/RACM analysis and 

has determined that the state reasonably 

identified potential control measures, 

modeled the attainment date that is as 

expeditious as practicable and 

reasonably selected RACT/RACM for 

the Libby area. 

6. Contingency Measures 

In conformance with Section 172(c)(9) 

of the CAA, the implementation rule 

requires that PM2.5 attainment area 

plans include contingency measures. 

These measures must be fully adopted 

or otherwise ready for quick 

implementation, should contain trigger 

mechanisms and an implementation 

schedule, should be measures not 

included in the SIP control strategy, and 

should provide the equivalent of one 

year of RFP. Once triggered, a 

contingency measure should take effect 

without further action by the State or 

EPA. 

The Libby SIP contains contingency 

measures for residential wood burning, 

re-entrained dust, and industrial 

facilities. If it is determined that 

residential wood burning contributes to 

an exceedance of the PM2.5 NAAQS, 

then only biomass pellet fuel burners 

may operate within the District. If reentrained dust contributes to 

noncompliance, then the existing 

regulations (which currently only apply 

in a limited area) are made applicable to 

the entire Air Pollution Control District. 

Finally, if an industrial facility 

contributes to noncompliance, the 

Montana Department of Environmental 

Quality (MTDEQ) will initiate 

contingency measures to reduce 

emissions. Once a contingency measure 

is initiated, it must remain active until 

the Libby SIP demonstration is revised 

and resubmitted to EPA for approval. 

The contingency measures for 

residential wood burning and reentrained dust meet the requirements of 

the implementation rule. The 

contingency measure for major point 

sources would require further action by 

MTDEQ to determine whether 

additional controls are necessary. 

However, the contingency measures for 

residential wood burning and reentrained dust are sufficient to meet the 

requirements of the CAA, including 

equivalence to one year of RFP. 

7. Transportation Conformity 

Requirements 

Transportation conformity is required 

under CAA section 176(c) (42 U.S.C. 

7506(c)) to ensure that transportation 

plans, transportation improvement 

programs (TIPs) and federally supported 

highway and transit projects are 

consistent with (‘‘conform to’’) the state 

air quality implementation plan. 

Transportation conformity applies to 

areas that are designated nonattainment, 

and to those areas redesignated to 

attainment after 1990 with a CAA 

section 175A maintenance plan 

(‘‘maintenance areas’’), for 

transportation-related criteria 

pollutants: carbon monoxide (CO), NOX

and particulate matter (PM2.5 and PM10). 

EPA’s transportation conformity rule 

(40 CFR parts 51 and 93) establishes the 

criteria and procedures for determining 

whether transportation activities 

conform to the SIP. One requirement of 

the rule is that transportation plans, 

TIPs, and projects must satisfy a 

regional emissions analysis for the 

relevant pollutants and precursors (40 

CFR 93.118, 119). However, section 

93.109(m) of this rule states that an area 

is not required to satisfy a regional 

emissions analysis for a pollutant or 

precursor if the SIP demonstrates that 

motor vehicle emissions of that 

pollutant or precursor are an 

insignificant contributor to the area’s air 

quality problem. In today’s notice, EPA 

is proposing to find that motor vehicle 

emissions of PM2.5 and NOX are 

insignificant contributors to Libby’s 

PM2.5 nonattainment problem. If this 

proposal is finalized, PM2.5 and NOX

motor vehicle emissions budgets 

(MVEB) would not be established and a 

regional emissions analysis would not 

be required for either PM2.5 or NOX in 

any future conformity determination in 

Libby. Please note, however, that this 

proposed action would not apply to 

PM2.5 hot-spot analyses for individual 

projects, if such an analysis is required 

in the future for transportation 

conformity purposes. 

There are specific transportation 

conformity provisions that EPA 

proposes to determine as applicable to 

the Libby PM2.5 nonattainment area. As 

provided in more detail in 40 CFR 

93.109(m), these specific conformity 

provisions are addressed when EPA 

finds that emissions from motor 

vehicles in the Libby PM2.5

nonattainment area are an insignificant 

contributor to the areas’ nonattainment 

problem for a relevant NAAQS and/or 

precursor. 

To consider making such an 

insignificant finding, EPA evaluated the 

provisions of 40 CFR 93.109(m) against 

the relevant information contained in 

the SIP attainment plan, the SIP 

revision’s associated technical support 

document (TSD), and additional 

information as developed by EPA. We 

evaluated the following factors in 

determining whether on-road direct 

PM2.5 and NOX emissions are 

insignificant contributors to the area’s 

PM2.5 air quality problem; (1) the 

percentage of motor vehicle emissions 

in the context of the total SIP inventory; 

(2) the current state of air quality as 

determined by monitoring data for that 

NAAQS; (3) the absence of SIP motor 

vehicle control measures; and (4) 

historical trends and future projections 

of the growth of motor vehicle 

emissions. Our evaluation and 

conclusions are as follows: 

a. The Percentage of PM2.5 Motor 

Vehicle Emissions in the Context of the 

Total SIP Inventory 

This factor, with regard to PM2.5

emissions, is addressed in two areas of 

the SIP revision documentation. Table 

27.12.11.4B (‘‘PM2.5 Annual 

Demonstration of Compliance’’) of the 

Libby attainment plan provides relevant 

information with regard to 2003–2004 

CMB percentages by source category, 

percent reduction in emissions due to 

control strategies, estimated growth in 

emissions over the 2005 to 2010 time 

period, and 2010 compliance year 

contributions. The dominant CMB 

source was residential woodstoves at 

82% with motor vehicle tailpipe 

emissions at 7% of total PM2.5 mass and 

diesel exhaust at 4% of the total PM2.5

mass. 

The contribution of motor vehicle 

PM2.5 emissions is also documented in 

Table 5.1A (‘‘Seasonal PM 2.5 Emissions 

in Libby by Source Category’’) of the 

SIP’s TSD. Table 5.1A presents 

estimated emissions based on metric 

tons and percentage of the inventory for 

2005, by season; we have provided these 

motor vehicle tailpipe PM2.5 emissions, 

as percent of total PM2.5 emissions, in 

Table V.7–1 below. We note that in 

Table 5.1A of the SIP’s TSD, the 

inventory is dominated by woodstove 

emissions in all four seasons. 


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TABLE V.7—1 MOTOR VEHICLE PM2.5 EMISSIONS PERCENTAGE OF TOTAL INVENTORY FOR 2005 

(All figures are in metric tons) 

Season Motor vehicle 

PM2.5 emissions 

Total inventory 

PM2.5 emissions 

Motor vehicle 

emissions % of 

total 

Winter ............................................................................................................................... 0.48 80.63 0.59 

Spring ............................................................................................................................... 0.55 46.43 1.18 

Summer ........................................................................................................................... 0.66 13.66 4.83 

Fall ................................................................................................................................... 0.51 97.67 0.52 

Total Year ................................................................................................................. 2.2 238.38 0.92 

As shown in Table V.7.–1 above, 

motor vehicle tailpipe PM2.5 emissions 

represent an annual average of only 

0.92% of the total PM2.5 inventory. That 

is, motor vehicle emissions are less than 

one percent of the inventory over the 

course of a year. During the summer, 

motor vehicle emissions make up close 

to five percent of the inventory, but 

motor vehicle emissions are only 

slightly higher during the summer than 

during other seasons. The motor vehicle 

emissions percentage is much greater 

during the summer compared with other 

seasons primarily because total PM2.5

emissions are significantly reduced 

during the summer compared to other 

seasons; summer is the season with the 

fewest emissions from woodstoves. The 

information provided in the State’s 

submittal supports a conclusion that 

regional PM2.5 on-road mobile source 

emissions are a minimal percentage in 

the context of the total PM2.5 emissions 

inventory. Therefore, this factor 

supports the proposed finding that onroad PM2.5 emissions are insignificant 

for the Libby PM2.5 nonattainment area. 

b. The Current State of Air Quality as 

Determined by Monitoring Data for the 

PM2.5 NAAQS 

This factor is addressed as shown in 

the table below. From the State’s SIP 

revision and section V.B.2 above, from 

2007 to 2009 the Libby area continues 

to demonstrate attainment of the 1997 

annual PM2.5 NAAQS. Furthermore, the 

trend in annual average concentrations 

is downward and coincides with the 

implementation of the woodstove 

changeout program. This data is based 

on quality-controlled and qualityassured monitoring data from 2005– 

2009 that are available in the EPA AQS. 

This factor supports the proposed 

finding that on-road PM2.5 emissions are 

insignificant for the Libby PM2.5

nonattainment area. 

TABLE V.2.–1 

Year 

PM2.5 annual weighted average 

(μg/m3) 

2005 ............ 15.8 

2006 ............ 15.2 

2007 ............ 13.0 

2008 ............ 12.9 

2009 ............ 10.7 

c. The Absence of SIP Motor Vehicle 

Control Measures for PM2.5

The Libby PM2.5 attainment plan 

relies on a 59% reduction in residential 

woodstove emissions to reach 

attainment of the annual PM2.5 NAAQS 

and took no credit for any emission 

reductions in the motor vehicle tailpipe 

and diesel exhaust categories (e.g. 

Federal tailpipe emission standards and 

fleet turnover). The State further 

described these assumptions in sections 

27.12.7.3 (‘‘Federal Tailpipe Standards 

Control Program’’) and 27.12.11.4 

(‘‘PM2.5 2010 Demonstration of 

Compliance’’) of the Libby attainment 

plan. EPA also notes there is no State or 

local mandated motor vehicle emission 

control requirements (e.g., inspection 

and maintenance program, fuels, or 

transportation control measures) for the 

Libby PM2.5 nonattainment area. 

Therefore, this factor supports the 

proposed finding that on-road PM2.5

emissions are insignificant for the Libby 

PM2.5 nonattainment area. 

d. Historical Trends and Future 

Projections of the Growth of Motor 

Vehicle PM2.5 Emissions 

Libby’s annual PM2.5 2001–2003 

design value was 15.9 μg/m3. In 

November 2003 through February 2004 

air quality data was collected in Libby 

to support CMB modeling. This CMB 

modeling showed that residential wood 

smoke was the primary source of PM2.5

in Libby. Table 27.12.11.4B in the Libby 

attainment plan shows that, when the 

results of the CMB modeling are applied 

to the air quality data from 2001–2003, 

residential wood smoke contributed 

13.0 μg/m3 (82%) of the 2001–2003 

annual PM2.5 design value, motor 

vehicle tailpipe emissions contributed 

1.1 μg/m3 (7%), and diesel exhaust 

emissions contributed 0.7 μg/m3 μg/m3

(4%). Based on the results of this 

modeling Montana based its attainment 

strategy for the area on a woodstove 

change-out program. 

The SIP assumes that the woodstove 

change-out program will reduce those 

emissions by 59% in 2010. The SIP also 

assumes that motor vehicle tailpipe 

emissions and diesel exhaust emissions 

would grow by 2.1% between 2005 and 

2010, which is equal to the expected 

population growth rate during that 

period. The SIP does not account for 

any reductions in motor vehicle 

emissions or diesel exhaust that would 

occur due to fleet turnover to new lower 

emission motor vehicles, on-road diesel 

vehicles or off-road equipment. Table 

27.12.11.4B in the Libby attainment 

plan shows that in 2010 the predicted 

annual average PM2.5 concentration 

would be 8.37 μg/m3. The table also 

shows that residential wood smoke is 

expected to contribute 5.44 μg/m3 (65%) 

in 2010, motor vehicle tailpipe 

emissions would contribute 1.12 μg/m3

(13%), and diesel exhaust emissions 

would contribute 0.71 μg/m3 (8%). As 

can be seen, on a percentage basis the 

contribution of motor vehicle emissions 

and diesel exhaust increases; however, 

overall PM2.5 concentrations are 

expected to decrease by 53% to 8.37 μg/ 

m3, the contribution of wood smoke 

emissions is expected to decrease by 

59%, and the total contribution of 

emissions from motor vehicles and 

diesel exhaust to PM2.5 mass in 2010 is 

expected to increase by only 0.03 μg/m3

between 2005 and 2010. This increase 

in mass is due to the assumptions that 

emissions from these sources increase at 

the same rate as population growth and 

that no emissions reductions from fleet 

turnover are included in the 

calculations. Both of these are 

conservative assumptions. 

EPA notes that the contribution of 

motor vehicle emissions of 13% to PM2.5

mass in 2010 represents the projected 

chemical mass balance of PM2.5 and not 

an emission inventory projection. The 


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5The 2005 NEI data from EPA’s PM2.5 24-hour 

2006 NAAQS final designations information are 

available at: http://www.epa.gov/ttn/naaqs/pm/ 

pm25_2006_techinfo.html. 

6See http://www.epa.gov/ttn/naaqs/pm/ 

pm25_2006_techinfo.html; Factor 4.B ‘‘Vehicle 

Miles Traveled’’. 

7 VMT data was communicated in a February 26, 

2010, email from Jim Carlin of MTDEQ to Tim Russ 

of EPA Region 8. 

SIP includes a base year PM2.5 inventory 

(Table 5.1A) for 2005. That inventory 

shows that motor vehicle emissions of 

PM2.5 are 2.20 tpy and that total PM2.5

emissions in the base year are 238.39 

tpy. Therefore, the motor vehicle 

emissions in the base year are slightly 

less than 1% of the total direct PM2.5

emissions. On the surface this may seem 

to be in conflict with the results of the 

CMB modeling, which shows that motor 

vehicle exhaust contributed about 7% of 

the PM2.5 mass in the base year. 

However, it should be noted that the 

chemical mass balance data and the 

PM2.5 data collected at the Libby 

Courthouse Annex represents only one 

receptor within the City of Libby, and 

only for the period of late 2003 through 

early 2004. While this location is 

believed to be representative of Libby’s 

air quality, numerous factors influence 

the local particulate matter 

concentrations and air quality. Local 

scale meteorology (wind speed, wind 

direction, temperature, relative 

humidity, barometric pressure, and 

solar radiation at a minimum), traffic 

patterns, and precipitation are a few 

examples of these factors which vary 

throughout the city. Accepting that 

variable conditions exist throughout 

Libby, as well as the inherent 

uncertainty associated with ambient air 

monitoring, the difference that exists 

between PM2.5 monitoring data at one 

receptor and a city-wide emission 

inventory appears to be plausible. 

We also note that the actual location 

of the monitor may have exposed it to 

additional influence from motor vehicle 

emissions. We have not performed an 

in-depth analysis, but we do note that 

the monitor is located directly adjacent 

to U.S. Highway 2, the main north/south 

highway through Libby. Although motor 

vehicle PM2.5 emissions are shown to be 

minimal in the State’s emissions 

inventory (ref. Table 5.1A: ‘‘Seasonal 

PM2.5 Emissions in Libby by Source 

Category’’ and Table V.7.-1 above), 

motor vehicle emissions may have 

shown a greater than anticipated 

contribution on the chemical mass 

balance analysis due to the monitor’s 

close proximity to Highway 2. 

Overall, this factor supports the 

proposed finding that on-road PM2.5

emissions are insignificant for the Libby 

PM2.5 nonattainment area. In summary, 

all four factors support the proposed 

finding. After weighing these four 

factors described in 40 CFR 93.109(m) 

and evaluated above, EPA proposes to 

find that on-road PM2.5 emissions are 

insignificant for the Libby PM2.5

nonattainment area. We turn to applying 

the four factors to on-road NOX

emissions. 

e. The Percentage of NOX Motor Vehicle 

Emissions in the Context of the Total 

SIP Inventory 

The Libby attainment plan focuses on 

directly emitted PM2.5 and controls of 

PM2.5 emissions from woodstoves and 

does not address any motor vehicle NOX

emissions other than to indicate in 

Table 27.12.11.4B ‘‘PM2.5 Annual 

Demonstration of Compliance’’ that the 

CMB data show that ammonium nitrate 

was only 5% of the mass found on the 

filters. EPA, therefore, drew upon other 

relevant, available data to evaluate 

whether NOX motor vehicle emissions 

in the Libby PM2.5 nonattainment area 

are significant and require that a NOX

motor vehicle emissions budget be 

established for transportation 

conformity purposes or whether on-road 

NOX emissions could be found 

insignificant based on the criteria in 40 

CFR 93.109(m). 

EPA reviewed relevant information 

from EPA’s National Emissions 

Inventory (NEI) data for 2005 that were 

used for the 2009 final designations for 

the 24-hour 2006 PM2.5 NAAQS (74 FR 

58688, November 13, 2009).5 However, 

since the NEI data were for Lincoln 

County as a whole, we needed to assess 

how much of the Lincoln County onroad NOX inventory could be 

apportioned to the Libby PM2.5

nonattainment area. Our methodology 

was to calculate how many vehicle 

miles traveled (VMT) the Libby PM2.5

nonattainment area contributes to 

Lincoln County’s total VMT and to 

assign that same proportion of the total 

Lincoln County on-road NOX emissions 

to the Libby PM2.5 nonattainment area, 

as explained further below. We then 

needed to determine what percentage 

this was of total NOX from the Libby 

PM2.5 nonattainment area. 

Specific emissions data for Lincoln 

County, MT, which includes the Libby 

PM2.5 nonattainment area, are presented 

in Table V.7.–2 below and are from 

EPA’s PM2.5 24-hour 2006 NAAQS final 

designations information. 

TABLE V.7.–2—(ALL EMISSION FIGURES ARE IN TONS PER YEAR) 

County Major category VOC NOX SO2 NH3 PM2.5 OC EC SO4 NO3 PMFine 

Lincoln .................. Fires .............................. 6106 310 277 425 2199 1286 219 20 10 664 

Lincoln .................. Non-Road ...................... 338 2403 169 1 76 16 55 0 0 4 

Lincoln .................. On-Road ........................ 366 545 15 23 11 3 6 0 0 2 

Lincoln .................. Other-Stationary ............ 871 138 74 57 453 108 16 5 1 323 

Total .............. ........................................ 7681 3395 535 506 2738 1412 296 25 11 994 

The ‘‘On-Road’’ or motor vehicle, 2005 

NEI emissions were calculated by EPA 

for Lincoln County based on a county 

annual total of VMT of 231,246,800. 

This VMT figure, which represents data 

for the entire county, is also referenced 

in our 2006 PM2.5 24-hour NAAQS final 

designations information.6

Based on the 2005 NEI data 

referenced above in Table V.7.–2, 

Lincoln County’s total annual VMT of 

231,246,800 results in approximately 

545 tpy of on-road NOX. To calculate 

the estimated on-road NOX emissions 

for the Libby PM2.5 nonattainment area, 

we first needed to determine what 

percentage of Lincoln County’s total 

VMT is attributed to the Libby PM2.5

nonattainment area. We then applied 

that VMT percentage to the total Lincoln 

County on-road NOX emissions to get 

the estimated on-road NOX emissions 

for the Libby PM2.5 nonattainment area. 

The total VMT for the Libby PM2.5

nonattainment area, 54,877,360, came 

from the MTDEQ.7 This is 23.73% of 

Lincoln County’s total VMT (i.e., 

54,877,360 VMT from Libby divided by 

231,246,800 VMT from Lincoln County 

as a whole). It is reasonable to assume 

that the Libby PM2.5 nonattainment area 

contributes this same percentage of onroad NOX emissions to the total Lincoln 

County on-road NOX emissions. 

Therefore, we applied this 23.73% to 

the Lincoln County total of 545 tpy of 


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8The ‘‘Fires’’ category of the 2005 NEI relates to 

wildfires, prescribed burns and such. This 

correlates to the ‘‘Large Prescribed Burning’’ and ‘‘General Burning’’ categories in the State’s Table 

5.1A. 

on-road motor vehicle NOX emissions, 

which results in approximately 129.33 

tpy of on-road NOX emissions for the 

Libby PM2.5 nonattainment area. In lieu 

of other specific data, EPA considers 

this approach a reasonable estimate of 

the on-road NOX emissions for the Libby 

PM2.5 nonattainment area. 

Once we had a figure for the number 

of tons of on-road NOX emissions from 

Libby, the next step in our analysis was 

to determine what percentage of the 

total anthropogenic NOX this represents. 

Again, since the NEI data available were 

for Lincoln County as a whole, we 

needed to assess how much of the 

Lincoln County total anthropogenic 

NOX could be apportioned to the Libby 

PM2.5 nonattainment area. To do so, we 

needed to establish what NOX emissions 

were from anthropogenic sources in the 

Libby PM2.5 nonattainment area other 

than from on-road motor vehicle 

tailpipes. To develop these particular 

emissions figures, we assumed that the 

percentage of Lincoln County’s 

anthropogenic NOX coming from Libby 

would be the same as the percentage of 

Lincoln County’s anthropogenic PM2.5

emissions coming from Libby, as 

described below. 

First, we determined the 

anthropogenic NOX emissions for 

Lincoln County from the ‘‘Non-Road’’ 

and ‘‘Other Stationary’’ source 

categories. We used the data from Table 

V.7.–2 above and eliminated the 

‘‘Fires’’ 8 and ‘‘On-Road’’ emissions 

categories from the Lincoln County 2005 

NEI data (see Table V.7.-3 below): 

TABLE V.7.–3—(ALL EMISSIONS ARE IN TONS PER YEAR) 

County Major category VOC NOX SO2 NH3 PM2.5 OC EC SO4 NO3 PM 

Fine 

Lincoln .................. Non-Road ...................... 338 2403 169 1 76 16 55 0 0 4 

Lincoln .................. Other-Stationary ............ 871 138 74 57 453 108 16 5 1 323 

Total .............. ........................................ 1209 2541 243 58 529 124 71 5 1 327 

The total anthropogenic NOX in 

Lincoln County from sources other than 

on-road is 2541 tpy. 

Next, we summed-up the PM2.5

emissions from the Libby PM2.5

nonattainment area from the State’s SIP 

emission inventory Table 5.1A, but did 

not include emissions from fires (i.e., 

PM2.5 emissions from ‘‘Large Prescribed 

Burning’’ and ‘‘General Burning’’ were 

not included from the State’s Table 

5.1A); see Table V.7.-4 below. 

TABLE V.7.–4—LIBBY ANTHROPOGENIC PM2.5 EMISSIONS

(As adapted from Table 5.1A ‘‘Seasonal PM2.5 Emissions in Libby by Source Category’’ of the Libby Attainment SIP Emission Inventory) 

Sources Winter Spring Summer Fall 

Woodstoves Residential/Com. ......................................................................................... 66.65 20.74 5.08 58.76 

Paved Roads Fugitive Dust ............................................................................................. 8.92 2.57 3.23 9.61 

Large Prescribed Burning ................................................................................................ - - - - - - - - - - - - 

General Burning ............................................................................................................... - - - - - - - - - - - - 

Locomotives ..................................................................................................................... 2.72 2.72 2.72 2.72 

Unpaved Roads Fugitive Dust ......................................................................................... 1.22 1.34 1.53 1.2 

Propane Heating Residential/Com. ................................................................................. 0.13 0.04 0.01 0.11 

Oil Heating Residential/Com. .......................................................................................... 0.48 0.15 0.04 0.42 

Aircraft .............................................................................................................................. 0.0 0.03 0.03 0.0 

Road & Building Construction Dust ................................................................................. 0.02 0.36 0.36 0.36 

Motor Vehicle Tailpipe ..................................................................................................... 0.48 0.55 0.66 0.51 

Total (Metric Tons) ................................................................................................... 80.62 28.50 13.66 73.69 

Total Short Tons (2000 lbs. per ton) ........................................................................ 88.88 31.42 15.06 81.24 

Total Annual Anthropogenic Short Tons of PM2.5 Emissions = 216.60 tons. 

Based on the data in Table V.7.-4 

above, the total annual anthropogenic 

short tons of PM2.5 emissions (without 

including emissions from the ‘‘Motor 

Vehicle Tailpipe’’ category) from ‘‘NonRoad’’ and ‘‘Other Stationary’’ sources in 

the Libby PM2.5 nonattainment area are 

estimated as 214.17 tons per year. 

The Libby PM2.5 nonattainment area’s 

annual emissions of PM2.5 from ‘‘NonRoad’’ and ‘‘Other Stationary’’ 

anthropogenic sources is 214.17 tpy, 

whereas these sources emit 529 tpy for 

Lincoln County as a whole (see Table 

V.7.-3 above). Therefore, Libby’s share 

of Lincoln County’s PM2.5 emissions 

from ‘‘Non-Road’’ and ‘‘Other Stationary’’ 

anthropogenic sources is approximately 

40.48%. 

We then added Lincoln County NOX

emissions from the ‘‘Non-Road’’ and 

‘‘Other Stationary’’ sources categories, 

2541 tpy (see Table V.7–3 above), and 

attributed 40.48% of those emissions to 

the Libby PM2.5 nonattainment area’s 

NOX ‘‘Non-Road’’ and ‘‘Other Stationary’’ 

sources categories, which results in 

1028.6 tpy. To summarize, EPA 

estimated the Libby PM2.5

nonattainment area’s on-road NOX

motor vehicle emissions as 129.33 tpy, 

and the non-road and other stationary 

sources’ NOX emissions as 1028.6 tpy. 

Therefore, the total estimated annual 

anthropogenic NOX emissions from all 

of these source categories are estimated 

to be 1157.93 tpy for the Libby PM2.5

nonattainment area. The approximate 

contribution of annual on-road NOX

motor vehicle emissions (129.33 tpy) to 

the total estimated NOX annual 

anthropogenic emissions from all 

sources (1157.93 tpy) in the Libby PM2.5

nonattainment area is 11.17% of the 

total inventory. 

EPA indicated in its July 1, 2004 

Transportation Conformity final rule (69 

FR 40004) that mobile source emissions 


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9EPA redesignated the insignificance provision of 

the transportation conformity rule from 40 CFR 

93.109(k) to 40 CFR 93.109(m) in its March 24, 2010 

‘‘PM Amendments’’ final rule (75 FR 14260). 

10Nitrogen oxides react in the atmosphere to form 

nitrates. For our purposes, the impact of NOX

emissions is measured as the amount of nitrates 

found at the PM2.5 monitor. 

of approximately 10% may be 

considered insignificant, but did not 

make 10% a specific threshold. While 

the 11.7% figure calculated for on-road 

NOX in the Libby PM2.5 nonattainment 

area is slightly greater than this, in this 

same rulemaking EPA explained: 

‘‘This example also illustrates the reason 

EPA believes it is important to have 

flexibility in implementing this provision. 

Although the commenter specifically 

mentions 10% as the threshold for finding 

motor vehicle emissions insignificant, EPA 

clarifies that this figure is a general guideline 

only. Depending on the circumstances, we 

may find that motor vehicle emissions that 

make up less than 10% of an area’s total 

inventory are still significant. Conversely, we 

may also find that motor vehicle emissions 

in excess of 10% are still insignificant, under 

certain circumstances relating to the overall 

composition of the air quality situation. In 

general, the percentage of motor vehicle 

emissions in the area’s total inventory is an 

important criterion for determining whether 

motor vehicles are a significant or 

insignificant contributor to an area’s air 

quality problem, yet there are other criteria 

that EPA will examine when making this 

finding, as described in the regulatory text for 

§ 93.109(k).’’ (69 FR 40062) 9

As stated in the 2004 preamble, 10 

percent is a guideline only. As 

described below, EPA considered other 

factors that lead EPA to propose that 

motor vehicle emissions of NOX are an 

insignificant regional contributor to the 

PM2.5 nonattainment problem. 

f. The Current State of Air Quality as 

Determined by Monitoring Data for 

PM2.5 NAAQS 

This factor is addressed with the 

ambient PM2.5 air quality data presented 

in section V.7.B above which 

demonstrate the Libby PM2.5

nonattainment area is attaining the 

PM2.5 annual NAAQS. Additional data, 

relevant to NOX or in this case nitrates 

derived from NOX emissions,10 were 

provided by EPA with the 2009 final 

designations for the 24-hour 2006 PM2.5

NAAQS. This information, as provided 

in Table V.7–5 below, is from EPA’s 

PM2.5 24-hour 2006 NAAQS final 

designations and is located at: http:// 

www.epa.gov/ttn/naaqs/pm/pm25_2006

_techinfo.html. 

TABLE V.7–5—PM2.5 COMPOSITION DATA FOR LIBBY, MT 

Area/County/State PM2.5 composition data Sulfate 

(μmg/m3) 

Nitrate 

(μmg/m3) 

Carbon 

(μmg/m3) 

Crustal 

(μmg/m3) 

Total 

(μmg/m3) 

Nitrate 

percent 

Carbon 

percent 

Libby/Lincoln/MT ............ Total Concentration (Cold) ...... 1.4 0.8 41.9 0.3 44.4 2 94 

Regional Concentration (Cold) 0.9 0.4 2.4 0.2 3.9 10 62 

Urban Concentration (Cold) .... 0.5 0.4 39.5 0.1 40.5 1 98 

Total Concentration (Warm) .... 1.2 0.0 6.7 0.8 8.7 0 77 

Regional Concentration 

(Warm).

1.0 0.0 2.5 1.1 4.6 0 54 

Urban Concentration (Warm) .. 0.2 0.0 4.2 0.0 4.4 0 95 

Total Concentration (Annual 

Average).

1.0 0.1 12.8 0.4 14.3 1 90 

As can be seen in Table V.7–5 above, 

nitrates (as derived from NOX) are a very 

small component of the PM2.5

composition found in the Libby PM2.5

nonattainment area. Therefore, NOX as 

derived from motor vehicle tailpipe 

emissions also is a very small 

component. This factor thus supports 

the proposed finding that on-road NOX

emissions are insignificant for the Libby 

PM2.5 nonattainment area. 

g. The Absence of SIP Motor Vehicle 

Control Measures for NOX

As discussed in section V.7.C above, 

the Libby PM2.5 attainment plan took no 

credit for any emission reductions in the 

motor vehicle tailpipe and diesel 

exhaust categories (e.g. Federal tailpipe 

emission standards and fleet turnover). 

The State further described these 

assumptions in sections 27.12.7.3 

(‘‘Federal Tailpipe Standards Control 

Program’’) and 27.12.11.4 (‘‘PM2.5 2010 

Demonstration of Compliance’’) of the 

Libby attainment plan. EPA also notes 

there is no State or local mandated 

motor vehicle emission control 

requirements (e.g., inspection and 

maintenance program, fuels, or 

transportation control measures) for the 

Libby PM2.5 nonattainment area. 

Therefore this factor supports the 

proposed finding that on-road NOX

emissions are insignificant for the Libby 

PM2.5 nonattainment area. 

h. Historical Trends and Future 

Projections of the Growth of NOX Motor 

Vehicle Emissions 

As noted in our discussion in section 

V.7.D above, the Libby attainment plan 

uses a 59% reduction in residential 

woodstove emissions to reach 

attainment of the annual PM2.5 NAAQS 

and took no credit for any emission 

reductions in the motor vehicle tailpipe 

and diesel exhaust categories. The State 

further described these assumptions in 

sections 27.12.7.3 (‘‘Federal Tailpipe 

Standards Control Program’’) and 

27.12.11.4 (‘‘PM2.5 2010 Demonstration 

of Compliance’’) of the Libby attainment 

plan. EPA notes that the State used a 

conservative emission inventory 

approach for projecting the 2010 

attainment year future growth which 

involved merely increasing the vehicle 

emissions by 2.1% (the population 

growth rate) from the 2005 base year 

inventory, and not taking any credit for 

potential emission reductions that may 

have been available from fleet turnover 

and the Federal tailpipe standards for 

vehicles. In addition, as we noted above, 

there are no State or local mandated 

motor vehicle emission control 

requirements (e.g., inspection and 

maintenance program) for the Libby 

PM2.5 nonattainment area. 

This factor supports the proposed 

finding that on-road NOX emissions are 

insignificant for the Libby PM2.5

nonattainment area. After weighing 

these four factors described in 40 CFR 

93.109(m) and evaluated above, EPA 

proposes to find that on-road NOx 

emissions are insignificant for the Libby 

PM2.5 nonattainment area. 

i. Conclusion 

In view of our evaluation presented 

above per 40 CFR 93.109(m), EPA is 

proposing to find that direct PM2.5 and 

NOX motor vehicle emissions are an 

insignificant contributor to the air 

quality issues associated with the PM2.5


emcdonald on DSK2BSOYB1PROD with PROPOSALS
55724 Federal Register / Vol. 75, No. 177 / Tuesday, September 14, 2010 / Proposed Rules 

annual NAAQS in the Libby PM2.5

nonattainment area; thus, motor vehicle 

emission budgets for on-road direct 

PM2.5 and NOX would not be established 

by this rulemaking. Based on our 

evaluation of the four factors described 

in 93.109(m), EPA proposes to conclude 

that it would be unreasonable to expect 

that the Libby PM2.5 nonattainment area 

would experience enough motor vehicle 

emissions growth such that a PM2.5

annual NAAQS violation would occur. 

VI. Proposed Action 

The EPA has reviewed Montana’s SIP 

revision for attaining the 15μg/m3

annual PM2.5 NAAQS for the Libby 

PM2.5 nonattainment area. EPA is 

proposing to approve the State of 

Montana’s revisions to the Lincoln 

County Air Pollution Control Program to 

be included in Montana’s SIP, 

submitted on June 26, 2006, and the 

Libby PM2.5 attainment plan, submitted 

on March 26, 2008. Action was not 

taken earlier on the June 26, 2006, 

submittal at the request of the State of 

Montana to delay action until the 

submittal of the Libby PM2.5 attainment 

plan at a later date. EPA has determined 

that the SIP meets applicable 

requirements of the CAA, as described 

in the Clean Air Fine Particle 

Implementation Rule. Specifically, EPA 

has determined that Montana’s SIP 

includes an attainment demonstration 

and adopted state regulations and 

programs needed to support the 

determination that the Libby PM2.5

nonattainment area will continue 

attaining the annual PM2.5 NAAQS. 

Finally, EPA is proposing to find onroad, directly emitted PM2.5 and NOX in 

the Libby, Montana nonattainment area 

insignificant for regional transportation 

conformity purposes. 

VII. Statutory and Executive Order 

Reviews 

A. Executive Order 12866, Regulatory 

Planning and Review 

Under Executive Order 12866, (58 FR 

51735 (October 4, 1993)) the Agency 

must determine whether the regulatory 

action is ‘‘significant’’ and therefore 

subject to the Office of Management and 

Budget (OMB) review and the 

requirements of the Executive Order. 

The Order defines ‘‘significant 

regulatory action’’ as one that is likely to 

result in a rule that may: (1) Have an 

annual effect on the economy of $100 

million or more or adversely affect in a 

material way the economy, a sector of 

the economy, productivity, competition, 

jobs, the environment, public health or 

safety, or state, local, or tribal 

governments or communities; (2) create 

a serious inconsistency or otherwise 

interfere with an action taken or 

planned by another agency; (3) 

materially alter the budgetary impact of 

entitlements, grants, user fees, or loan 

programs or the rights and obligations of 

recipients thereof; or (4) raise novel 

legal or policy issues arising out of legal 

mandates, the President’s priorities, or 

the principles set forth in the Executive 

Order.’’ The OMB has exempted this 

regulatory action from Executive Order 

12866 review. 

B. Paperwork Reduction Act 

This action does not impose an 

information collection burden under the 

provisions of the Paperwork Reduction 

Act, 44 U.S.C. 3501 et seq. This action 

proposes to approve the SIP revisions 

submitted by the State of Montana. 

C. Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) 

generally requires an agency to prepare 

a regulatory flexibility analysis of any 

rule subject to notice and comment 

rulemaking requirements under the 

Administrative Procedure Act or any 

other statute unless the agency certifies 

that the rule will not have a significant 

economic impact on a substantial 

number of small entities. Small entities 

include small businesses, small 

organizations, and small governmental 

jurisdictions. 

This proposed rule will not have a 

significant impact on a substantial 

number of small entities because SIP 

approvals and disapprovals under 

section 110 and subchapter I, part D of 

the Clean Air Act do not create any new 

requirements, but simply approve or 

disapprove requirements that the state is 

already imposing. Therefore because the 

Federal SIP approval does not create 

any new requirements, I certify that this 

action will not have a significant 

economic impact on a substantial 

number of small entities. Moreover, due 

to the nature of the Federal-state 

relationship under the Clean Air Act, 

preparation of flexibility analysis would 

constitute Federal inquiry into the 

economic reasonableness of state action. 

The Clean Air Act forbids EPA to base 

its actions concerning SIPs on such 

grounds. Union Electric Co., v. U.S. 

EPA, 427 U.S. 246, 255–66 (1976); 42 

U.S.C. 7410(a)(2). 

D. Unfunded Mandates Reform Act 

Title II of the Unfunded Mandates 

Reform Act of 1995 (UMRA), Public 

Law 104–4, establishes requirements for 

Federal agencies to assess the effects of 

their regulatory actions on state, local, 

and tribal governments and the private 

sector. Under section 202 of the UMRA, 

EPA generally must prepare a written 

statement, including a cost-benefit 

analysis, for proposed and final rules 

with ‘‘Federal mandates’’ that may result 

in expenditures to state, local, and tribal 

governments, in the aggregate, or to the 

private sector, of $100 million or more 

in any one year. Before promulgating an 

EPA rule for which a written statement 

is needed, section 205 of the UMRA 

generally requires EPA to identify and 

consider a reasonable number of 

regulatory alternatives and adopt the 

least costly, most cost-effective or least 

burdensome alternative that achieves 

the objectives of the rule. The 

provisions of section 205 do not apply 

when they are inconsistent with 

applicable law. Moreover, section 205 

allows EPA to adopt an alternative other 

than the least costly, most cost-effective 

or least burdensome alternative if the 

Administrator publishes with the final 

rule an explanation why that alternative 

was not adopted. Before EPA establishes 

any regulatory requirements that may 

significantly or uniquely affect small 

governments, including tribal 

governments, it must have developed 

under section 203 of the UMRA a small 

government agency plan. The plan must 

provide for notifying potentially 

affected small governments, enabling 

officials of affected small governments 

to have meaningful and timely input in 

the development of EPA regulatory 

proposals with significant Federal 

intergovernmental mandates, and 

informing, educating, and advising 

small governments on compliance with 

the regulatory requirements. 

EPA has determined that this rule 

does not contain a Federal mandate that 

may result in expenditures of $100 

million or more for state, local, and 

tribal governments, in the aggregate, or 

the private sector in any one year. This 

Federal action proposes to partially 

approve and partially disapprove preexisting requirements under state or 

local law, and to disapprove a 

redesignation request, and imposes no 

new requirements. Accordingly, no 

additional costs to state, local, or tribal 

governments, or to the private sector, 

result from this action. Thus, today’s 

rule is not subject to the requirements 

of sections 202 and 205 of the UMRA. 

E. Executive Order 13132, Federalism 

Executive Order 13132, entitled 

‘‘Federalism’’ (64 FR 43255, August 10, 

1999), requires EPA to develop an 

accountable process to ensure 

‘‘meaningful and timely input by state 

and local officials in the development of 

regulatory policies that have federalism 

implications.’’ ‘‘Policies that have 

federalism implications’’ is defined in 


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Federal Register / Vol. 75, No. 177 / Tuesday, September 14, 2010 / Proposed Rules 55725 

the Executive Order to include 

regulations that have ‘‘substantial direct 

effects on the states, on the relationship 

between the national government and 

the states, or on the distribution of 

power and responsibilities among the 

various levels of government.’’ 

This proposed rule does not have 

federalism implications. It will not have 

substantial direct effects on the states, 

on the relationship between the national 

government and the states, or on the 

distribution of power and 

responsibilities among the various 

levels of government, as specified in 

Executive Order 13132. This rule merely 

proposes to partially approve and 

partially disapprove state rules 

implementing a Federal standard, and to 

disapprove a redesignation request, and 

does not alter the relationship or the 

distribution of power and 

responsibilities established in the Clean 

Air Act. Thus, Executive Order 13132 

does not apply to this rule. 

F. Executive Order 13175, Coordination 

With Indian Tribal Governments 

Executive Order 13175, entitled 

Consultation and Coordination With 

Indian Tribal Governments (65 FR 

67249, November 9, 2000), requires EPA 

to develop an accountable process to 

ensure meaningful and timely input by 

tribal officials in the development of 

regulatory policies that have tribal 

implications. This proposed rule does 

not have tribal implications, as specified 

in Executive Order 13175. It will not 

have substantial direct effects on tribal 

governments, on the relationship 

between the Federal government and 

Indian tribes, or on the distribution of 

power and responsibilities between the 

Federal government and Indian tribes. 

This action does not involve or impose 

any requirements that affect Indian 

Tribes. Thus, Executive Order 13175 

does not apply to this rule. 

G. Executive Order 13045, Protection of 

Children From Environmental Health 

Risks and Safety Risks 

Protection of Children From 

Environmental Health Risks and Safety 

Risks (62 FR 19885, April 23, 1997), 

applies to any rule that: (1) Is 

determined to be economically 

significant as defined under Executive 

Order 12866, and (2) concerns an 

environmental health or safety risk that 

EPA has reason to believe may have a 

disproportionate effect on children. If 

the regulatory action meets both criteria, 

the Agency must evaluate the 

environmental health or safety effects of 

the planned rule on children, and 

explain why the planned regulation is 

preferable to other potentially effective 

and reasonably feasible alternatives 

considered by the Agency. 

EPA interprets Executive Order 13045 

as applying only to those regulatory 

actions that are based on health or safety 

risks, such that the analysis required 

under section 5–501 of the Order has 

the potential to influence the regulation. 

This proposed rule is not subject to 

Executive Order 13045 because it 

proposes to approve a state rule 

implementing a Federal program. 

H. Executive Order 13211, Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This rule is not subject to Executive 

Order 13211, Actions Concerning 

Regulations That Significantly Affect 

Energy Supply, Distribution, or Use (66 

FR 28355, May 22, 2001) because it is 

not a significant regulatory action under 

Executive Order 12866. 

I. National Technology Transfer and 

Advancement Act 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (‘‘NTTAA’’), Public Law 

104–113, section 12(d) (15 U.S.C. 272 

note) directs EPA to use voluntary 

consensus standards in its regulatory 

activities unless to do so would be 

inconsistent with applicable law or 

otherwise impractical. Voluntary 

consensus standards are technical 

standards (e.g., materials specifications, 

test methods, sampling procedures, and 

business practices) that are developed or 

adopted by voluntary consensus 

standards bodies. The NTTAA directs 

EPA to provide Congress, through OMB, 

explanations when the Agency decides 

not to use available and applicable 

voluntary consensus standards. 

This proposed rulemaking does not 

involve technical standards. Therefore, 

EPA is not considering the use of any 

voluntary consensus standards. 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Intergovernmental 

relations, Oxides of nitrogen, Particulate 

matter, Reporting and recordkeeping 

requirements. 

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

Dated: September 2, 2010. 

Stephen S. Tuber, 

Acting Regional Administrator, Region 8. 

[FR Doc. 2010–22848 Filed 9–13–10; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R05–OAR–2010–0210; FRL–9201–3] 

Approval and Promulgation of Air 

Quality Implementation Plans; Indiana; 

Kentucky; Louisville Nonattainment 

Area; Determination of Attainment of 

the Fine Particle Standard 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: EPA is proposing to 

determine that the bi-state Louisville 

(Indiana and Kentucky) fine particle 

(PM2.5) nonattainment area has attained 

the 1997 annual average PM2.5 National 

Ambient Air Quality Standard 

(NAAQS). This proposed determination 

is based upon complete, qualityassured, and certified ambient air 

monitoring data for the 2007–2009 

period showing that the area has 

monitored attainment of the annual 

PM2.5 NAAQS. If EPA finalizes this 

proposed determination, the 

requirements for the area to submit an 

attainment demonstration and 

associated reasonably available control 

measures (RACM), a reasonable further 

progress (RFP) plan, contingency 

measures, and other planning State 

Implementation Plan (SIP) revisions 

related to attainment of the standard 

shall be suspended for so long as the 

area continues to attain the annual PM2.5

NAAQS. 

DATES: Comments must be received on 

or before October 14, 2010. 

ADDRESSES: Submit your comments 

regarding the Indiana portion of the bistate Louisville area, identified by 

Docket ID No. EPA–R05–OAR–2010– 

0210, by one of the following methods: 

1. http://www.regulations.gov: Follow 

the on-line instructions for submitting 

comments. 

2. E-mail: bortzer.jay@epa.gov. 

3. Fax: (312) 692–2054. 

4. Mail: Jay Bortzer, Chief, Air 

Programs Branch (AR–18J), U.S. 

Environmental Protection Agency, 77 

West Jackson Boulevard, Chicago, 

Illinois 60604. 

5. Hand Delivery: Jay Bortzer, Chief, 

Air Programs Branch (AR–18J), U.S. 

Environmental Protection Agency, 77 

West Jackson Boulevard, Chicago, 

Illinois 60604. Such deliveries are only 

accepted during the Regional Office 

normal hours of operation, and special 

arrangements should be made for 

deliveries of boxed information. The 

Regional Office official hours of 


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