State and Tribal Comment Summary and Response Document on EPA’s
Recommended Area Designations for the 2006 24-hour PM2.5 Designation
Recommendations

EAP-HQ-OAR-2007-0562

December 22, 2008

TABLE OF CONTENTS

  TOC \o "1-3" \h \z \u    HYPERLINK \l "_Toc217305073"  List of Tables
 PAGEREF _Toc217305073 \h  3

  HYPERLINK \l "_Toc217305074"  List of Figures	  PAGEREF _Toc217305074
\h  3

  HYPERLINK \l "_Toc217305075"  List of Acronyms	  PAGEREF _Toc217305075
\h  4

  HYPERLINK \l "_Toc217305076"  GENERAL ISSUES	  PAGEREF _Toc217305076
\h  6

  HYPERLINK \l "_Toc217305077"  SECTION I:  2006-2008 Data	  PAGEREF
_Toc217305077 \h  6

  HYPERLINK \l "_Toc217305078"  SECTION II:  Contributing Emissions
Score (CES)	  PAGEREF _Toc217305078 \h  6

  HYPERLINK \l "_Toc217305079"  SECTION III:  Technical Analysis
PAGEREF _Toc217305079 \h  24

  HYPERLINK \l "_Toc217305080"  SECTION IV:  Power Plant Issues
PAGEREF _Toc217305080 \h  35

  HYPERLINK \l "_Toc217305081"  SECTION V:  Consideration of Other
Regulations	  PAGEREF _Toc217305081 \h  37

  HYPERLINK \l "_Toc217305082"  SECTION VI:  Exceptional Events
PAGEREF _Toc217305082 \h  41

  HYPERLINK \l "_Toc217305083"  SECTION VII:  Other General Issues
PAGEREF _Toc217305083 \h  42

  HYPERLINK \l "_Toc217305084"  SECTION VIII:  Typographical Errors
PAGEREF _Toc217305084 \h  44

  HYPERLINK \l "_Toc217305085"  AREA-SPECIFIC ISSUES	  PAGEREF
_Toc217305085 \h  46

  HYPERLINK \l "_Toc217305086"  Allentown, PA	  PAGEREF _Toc217305086 \h
 46

  HYPERLINK \l "_Toc217305087"  Birmingham, AL	  PAGEREF _Toc217305087
\h  49

  HYPERLINK \l "_Toc217305088"  California Air Resources Board (CARB)
Multi-Area	  PAGEREF _Toc217305088 \h  56

  HYPERLINK \l "_Toc217305089"  Chicago, IL-IN	  PAGEREF _Toc217305089
\h  57

  HYPERLINK \l "_Toc217305090"  Chico, CA	  PAGEREF _Toc217305090 \h  62

  HYPERLINK \l "_Toc217305091"  Cincinnati-Hamilton, OH-KY-IN	  PAGEREF
_Toc217305091 \h  63

  HYPERLINK \l "_Toc217305092"  Clarksville, TN-KY	  PAGEREF
_Toc217305092 \h  68

  HYPERLINK \l "_Toc217305093"  Cleveland-Akron-Lorain, OH	  PAGEREF
_Toc217305093 \h  73

  HYPERLINK \l "_Toc217305094"  Columbus, OH	  PAGEREF _Toc217305094 \h
75

  HYPERLINK \l "_Toc217305095"  Davenport-Moline-Rock Island, IA-IL
PAGEREF _Toc217305095 \h  77

  HYPERLINK \l "_Toc217305096"  Dayton-Springfield, OH	  PAGEREF
_Toc217305096 \h  82

  HYPERLINK \l "_Toc217305097"  Detroit-Ann Arbor, MI	  PAGEREF
_Toc217305097 \h  83

  HYPERLINK \l "_Toc217305098"  Evansville, IN	  PAGEREF _Toc217305098
\h  93

  HYPERLINK \l "_Toc217305099"  Fairbanks, AK	  PAGEREF _Toc217305099 \h
 94

  HYPERLINK \l "_Toc217305100"  Fort Belknap Indian Community, MT
PAGEREF _Toc217305100 \h  99

  HYPERLINK \l "_Toc217305101"  Grand Rapids, MI	  PAGEREF _Toc217305101
\h  99

  HYPERLINK \l "_Toc217305102"  Green Bay, WI	  PAGEREF _Toc217305102 \h
 100

  HYPERLINK \l "_Toc217305103"  Huntington-Ashland, WV-KY-OH	  PAGEREF
_Toc217305103 \h  101

  HYPERLINK \l "_Toc217305104"  Imperial County, CA	  PAGEREF
_Toc217305104 \h  115

  HYPERLINK \l "_Toc217305105"  Indianapolis, IN	  PAGEREF _Toc217305105
\h  118

  HYPERLINK \l "_Toc217305106"  Juneau, AK	  PAGEREF _Toc217305106 \h
119

  HYPERLINK \l "_Toc217305107"  Klamath Falls, OR	  PAGEREF
_Toc217305107 \h  121

  HYPERLINK \l "_Toc217305108"  Knoxville-Sevierville-LaFollette, TN
PAGEREF _Toc217305108 \h  121

  HYPERLINK \l "_Toc217305109"  Logan, UT-ID	  PAGEREF _Toc217305109 \h
122

  HYPERLINK \l "_Toc217305110"  Louisville, KY-IN	  PAGEREF
_Toc217305110 \h  124

  HYPERLINK \l "_Toc217305111"  Madison-Baraboo, WI	  PAGEREF
_Toc217305111 \h  137

  HYPERLINK \l "_Toc217305112"  Milwaukee-Racine, WI	  PAGEREF
_Toc217305112 \h  138

  HYPERLINK \l "_Toc217305113"  Muscatine, IA	  PAGEREF _Toc217305113 \h
 138

  HYPERLINK \l "_Toc217305114"  Nez Perce Tribe	  PAGEREF _Toc217305114
\h  140

  HYPERLINK \l "_Toc217305115"  Oakridge, OR	  PAGEREF _Toc217305115 \h
141

  HYPERLINK \l "_Toc217305116"  Paducah-Mayfield, KY-IL	  PAGEREF
_Toc217305116 \h  141

  HYPERLINK \l "_Toc217305117"  Parkersburg-Marietta, WV-OH	  PAGEREF
_Toc217305117 \h  148

  HYPERLINK \l "_Toc217305118"  Pascua Yaqui Tribe	  PAGEREF
_Toc217305118 \h  154

  HYPERLINK \l "_Toc217305119"  Philadelphia-Wilmington, PA-NJ-DE
PAGEREF _Toc217305119 \h  154

  HYPERLINK \l "_Toc217305120"  Pinehurst, ID	  PAGEREF _Toc217305120 \h
 169

  HYPERLINK \l "_Toc217305121"  Sacramento, CA	  PAGEREF _Toc217305121
\h  171

  HYPERLINK \l "_Toc217305122"  Saint Louis, MO-IL	  PAGEREF
_Toc217305122 \h  173

  HYPERLINK \l "_Toc217305123"  Salt Lake City-Provo, UT	  PAGEREF
_Toc217305123 \h  177

  HYPERLINK \l "_Toc217305124"  San Carlos Apache Indian Reservation, CA
  PAGEREF _Toc217305124 \h  191

  HYPERLINK \l "_Toc217305125"  Youngstown, OH	  PAGEREF _Toc217305125
\h  193

  HYPERLINK \l "_Toc217305126"  Yuba City-Marysville, CA	  PAGEREF
_Toc217305126 \h  193

List of Tables

  TOC \h \z \c "Table"    HYPERLINK \l "_Toc217331174"  Table 1.
Delaware EGUs.	  PAGEREF _Toc217331174 \h  167

  HYPERLINK \l "_Toc217331175"  Table 2.  Moor Facility Annual Emissions
Limits.	  PAGEREF _Toc217331175 \h  167

  HYPERLINK \l "_Toc217331176"  Table 3.  PM2.5 Modeling Results.  From
the MDNR 10-18-08 response.	  PAGEREF _Toc217331176 \h  175

  HYPERLINK \l "_Toc217331177"  Table 4.  Days with High Concentrations
at Granite City or VFW.

	From the MDNR October 18, 2008 response.	  PAGEREF _Toc217331177 \h
177

List of Figures

  TOC \h \z \c "Figure"    HYPERLINK \l "_Toc217329864"  Figure 1. Wind
Pattern Diagram for January 11 through 13, 2004.	  PAGEREF _Toc217329864
\h  15

  HYPERLINK \l "_Toc217329865"  Figure 2.  HYSPLIT Back Trajectory for
January 13, 2004, all Salt Lake County Monitors.	  PAGEREF _Toc217329865
\h  16

  HYPERLINK \l "_Toc217329866"  Figure 3.  Meteorology Near the Utah
County/Salt Lake County Line, January 13, 2004.	  PAGEREF _Toc217329866
\h  17

  HYPERLINK \l "_Toc217329867"  Figure 4.  Wind Pattern Diagram for
January 20 through 22, 2004.	  PAGEREF _Toc217329867 \h  18

  HYPERLINK \l "_Toc217329868"  Figure 5.  24-hour Backtrajectory for
January 22, 2004, All Salt Lake County Monitors.	  PAGEREF _Toc217329868
\h  19

  HYPERLINK \l "_Toc217329869"  Figure 6.  Meteorology Near the Utah
County/Salt Lake County Line, January 22, 2004.	  PAGEREF _Toc217329869
\h  20

  HYPERLINK \l "_Toc217329870"  Figure 7.  Wind Pattern Diagram for
January 24 through 26, 2006.	  PAGEREF _Toc217329870 \h  21

  HYPERLINK \l "_Toc217329871"  Figure 8.  24-hour Backtrajectory for
January 26, 2006.	  PAGEREF _Toc217329871 \h  22

  HYPERLINK \l "_Toc217329872"  Figure 9.  Utah DOT Alpine and Bluffdale
Meteorology Station Locations.	  PAGEREF _Toc217329872 \h  23

  HYPERLINK \l "_Toc217329873"  Figure 10.  Point of the Mountain
Surface Winds, January 21-30, 2007.	  PAGEREF _Toc217329873 \h  24

  HYPERLINK \l "_Toc217329874"  Figure 11.  Pollution Rose for St. Clair
County, Michigan.	  PAGEREF _Toc217329874 \h  91

  HYPERLINK \l "_Toc217329875"  Figure 12.  Position of Herriman and
Highland relative to Point of the Mountain.	  PAGEREF _Toc217329875 \h
181

  HYPERLINK \l "_Toc217329876"  Figure 13.  Concentration and Point of
the Mountain Surface Winds on the Peak PM2.5 Day of 2007.	  PAGEREF
_Toc217329876 \h  182

  HYPERLINK \l "_Toc217329877"  Figure 14.  Point of the Mountain
Meteorology, January 27, 2007.	  PAGEREF _Toc217329877 \h  183

List of Acronyms

Acronym	Definition

AQS	Air Quality System

ASOS	Automated Surface Observing Systems

BACT	Best Available Control Technology

BART	Best Available Retrofit Technology

CAIR	Clean Air Interstate Rule

CALGRID	California Photochemical Grid

CAMx	Comprehensive Air Quality Model with Extensions

CARB	California Air Resources Board

CBSA	Core Based Statistical Area

CEM	Continuous Emissions Monitoring

CENRAP	Central Regional Air Planning Association

CES	Continuous Emissions Score

CMAQ	Community Multi-Scale Air Quality Modeling

CMSA	Combined Metropolitan Statistical Area

CRPAQS	California Regional PM10/PM2.5 Air Quality Study

CSA	Combined Statistical Area

EDAS	Eta Data Assimilation System

EGU	Electric Generating Unit

ESP	Electrostatic Precipitator

FEM	Federal Equivalent Method

FGD	Flue Gas Desulfurization

FHWA	Federal Highway Administration

FRM	Federal Reference Method

GIS	Geographic Information Systems

HPMS	Highway Performance Modeling System

HYSPLIT	Hybrid Single Particle Lagrangian Integrated Trajectory

KYOVA	Metropolitan Planning Organization for southwestern West Virginia
and southern Ohio

LADCO	Lake Michigan Air Directors Consortium

LAER	Lowest Achievable Emission Rate

LMACD	Louisville Metropolitan Air Control District

MANE-VU	Mid-Atlantic/Northeast Visibility Union

MARAMA	Mid-Atlantic Regional Air Management Association

MVEB	Motor Vehicle Emission Budget

MPO	Metropolitan Planning Organization

MSA	Metropolitan Statistical Area

NAAQS	National Ambient Air Quality Standard

NEEDS	National Electric Energy Data System

NEI	National Emission Inventory

NEPA	National Environmental Policy Act

NMIM	National Mobile Inventory Model

NOAA	National Oceanic and Atmospheric Administration

OTC	Ozone Transport Commission

PM	Particulate Matter

PMF	Positive Matrix Factorization

PSAT	Particulate Source Apportionment Technology

PSD	Prevention of Significant Deterioration

QA	Quality Assurance

RACT	Reasonably Available Control Technology

SCR	Selective  Catalytic Reduction

SIP	State Implementation Plan

SLAMS	State and Local Air Monitoring Stations

SNCR	Selective Non-Catalytic Reduction

SOFA	Separated Overfire Air

TSD	Technical Support Document

UMAERO/MM5	Urban Airshed Model for Aerosols/Mesoscale Model Version 5

VMT	Vehicle Miles Traveled

WWW	Wood-Washington-Wirt

GENERAL ISSUES

SECTION I:  2006-2008 Data

State Comment:  Consideration of 2008 Data

A number of States believe that data for one or more of the areas
violating the 2006

24-hour PM2.5 National Ambient Air Quality Standard (NAAQS) may show
attainment based on 2006-2008 air quality data.  These States ask that
EPA consider 2006-2008 data for purposes of determining final area
designations.

EPA Response:

The U.S. Environmental Protection Agency (EPA or the Agency) understands
the States’ concerns with using 2005-2007 data in lieu of the most
recent data (2006-2008) for making designation decisions.  The Agency
recognizes that many areas in the country are making improvements in
their air quality and believes that it is important to recognize such
improvements.  In making decisions about whether an area is meeting the
24-hour PM2 5 NAAQS, EPA also believes that it is important to use the
most recent air quality data.  EPA will be unable to use 2008 air
quality data for the designation decisions that will be made in December
2008 because that data will not be final and certified by that date.
However, all States will still have the opportunity to benefit from
improvements air quality by using 2008 air quality data to demonstrate
attainment of the 24-hour PM2.5 NAAQS.

Prior to the effective date of final 24-hour PM2.5 designations, States
will have the opportunity to provide more recent data showing that an
area is attaining the 24-hour PM2.5 NAAQS.  To do so, a State must
submit its complete, quality assured, certified 2008 air quality data to
EPA earlier than the usual June 30 deadline.  This early submittal
deadline will be February 20, 2009 – approximately 45 days prior to
the 90-day effective date of publication of the final 24-hour PM2.5
designations.  If the Agency agrees that a change of designation status
is appropriate based on 2006-2008 air quality data, it would withdraw
the nonattainment designation prior to the 90-day effective date of
final 24-hour PM2.5 designations and take a new final action designating
such areas consistent with the new 2008 data.

SECTION II:  Contributing Emissions Score (CES)

General Response to Comments Regarding the CES:

Several commenters asserted that too much emphasis had been placed on
the Contributing Emissions Score (CES) in deciding the nonattainment
area boundaries.  EPA has stated that the CES is one tool which utilizes
information from the nine factors recommended through guidance to be
used in determining potential nonattainment area boundaries.  EPA’s
intent in developing and utilizing the CES was to have it serve as a
starting point in determining the possible spatial extent of a potential
nonattainment area with additional information through the use of the
nine factors as well as other information the Federal, State or Local
air agency could provide to determine an area that was contributing to
concentrations greater than the level of the standard.  The CES was in
no way considered to be outcome determinative, but just one more
analytical tool that could help inform the final boundary decision.

As stated in the Technical Support Document (TSD), the CES represents a
generalized approach that was implemented across the country for
consistency purposes.  The Agency strongly encouraged State and Local
agencies to submit other data and analyses to provide a more detailed
and specific characterization of the contributing emissions to the
ambient PM2.5 concentrations violating the NAAQS.  The comments EPA has
received including these additional pieces of information have played a
major role in the final decision making process.

Other commenters stated that the CES was limited based on the data and
the weighting factors used in its calculation.  EPA recognizes that it
is difficult for any analytical tool to completely characterize the
unique and complex conditions observed in many areas across the country
using a general approach.  The CES TSD clearly states that several
factors could not be adequately accounted for such as topography,
overall emissions estimates and emissions estimates in counties with
isolated densely populated areas or large rural areas.  EPA recognized
that additional information from the State and Local agencies would be
required to better characterize these unique circumstances and
encouraged State and Local agencies to submit through the comment
process any supplemental information such as population density,
commuting patterns, more detailed or localized weather data, and
topography data.  Additional data and analyses were received to aid U.S.
EPA staff in better determining the spatial extent of areas in parts of
the country where these limitations were experienced and were considered
to help inform the final regulatory decision.  Many States, however, did
not provide additional analyses which required the Agency to use the
information it had on hand at the end of the comment period to inform
its decision.

State Comment:  Introduction and application of CES methodology

A number of States expressed concerns that information about the CES
should have been introduced to the States much sooner, and that it can
produce obscure or inaccurate results.

EPA Response:

The concepts used in the CES were introduced early in the process at the
PM2.5 Implementation and Designations Workshop held in Chicago, IL from
June 20-21, 2007.  At this workshop, the concept of an emissions score
was presented that envisioned taking into account an area’s emissions,
back trajectories, and the speciation increments.  That presentation can
be found at   HYPERLINK
"http://www.epa.gov/ttn/naaqs/pm/presents/pm2.5_designations_part3.pdf"
http://www.epa.gov/ttn/naaqs/pm/presents/pm2.5_designations_part3.pdf .
At this meeting EPA expressed its interest in further developing some
sort of score similar to what was developed during the designation
process for the 1997 PM2.5 NAAQS, utilizing the concepts presented
during the Chicago workshop.

EPA introduced the CES in its entirety through its modification letters
to States provided in 2008, and allowed the States to further comment on
the technique.  This provided States the opportunity to assess the
applicability of the CES to areas within their States.

California:

Although the CES is only one element in determining the nonattainment
boundary areas, a high CES suggests that a county has a high impact on
the adjacent violating county.  However, CES numbers are based on data
for entire counties.  The CES should be adjusted to reflect only those
portions of a county to be included with an adjoining nonattainment
area, such as Solano, El Dorado, and Placer Counties within the
Sacramento nonattainment area.  The higher score of Solano was
discounted based on its contribution to the San Francisco Bay Area
nonattainment area and the higher population in the western portion of
the county.  The high scores for Placer and El Dorado were based,
partially, on analysis done for the entire counties.  As noted in a U.S.
EPA Technical Document (Rizzo and Hunt, 2008), the CES methodology uses
county-based emissions inventories which may be inaccurate in counties
with large rural populations or with mountainous terrain, both of which
occur in El Dorado and Placer.  Although EPA took some of this into
account in recommending only a part of each county for inclusion in the
nonattainment area, it did not take into account the fact that the
majority of PM2.5 emissions are from residential wood burning.  These
emissions were recently found to be inaccurate (pages 17 and 18 of the
California comment letter) and a significant portion may be occurring in
the Lake Tahoe Air Basin segment of these counties.

Use of population and population growth as factors in EPA’s
decision-making was not consistent throughout the country.  Warren
County, NJ is an example of a county not included with an adjacent
violating area.  According to EPA,

“Warren County [New Jersey] ranks low in terms of population and in
population density in comparison to counties located near the violating
monitor in Northampton County, Pennsylvania.  In comparison to the two
counties that have been recommend as nonattainment for the Allentown,
PA-NJ area, Warren County’s population and population density is below
50 percent that of Lehigh and Northampton.  (U.S. EPA Response to New
Jersey, 2008)”.

Warren County’s population density is, in fact, 32 percent of Lehigh
County and 40 percent of Northampton County.  Although the Sacramento
County population is larger than the populations for counties around
Warren County, NJ, Sacramento’s population density is very similar.
Both total populations and population densities for all surrounding
counties are below those of Sacramento County and far below EPA stated
limit of above 50 percent.

In an additional example, Hamblen County, part of the
Knoxville-Sevierville-LaFollette,

TN Core Based Statistical Area (CBSA), has a population density 44
percent of neighboring (and violating) Knox County.  Hamblen County was
designated in attainment (U.S. EPA Response to Tennessee, 2008).  There
are many other examples of counties with higher population densities
than those adjoining Sacramento, within a MSA, but not designated
nonattainment.  EPA has placed a high importance on the CES in
designating nonattainment areas.  While several counties in California
have a relatively low CES and no violating monitor, EPA has still
proposed a nonattainment designation in tandem with neighboring
violating counties.  In several other areas throughout the country,
however, counties with similar, or higher, CES are not wed to their
adjacent nonattainment counties (Table 2-3 on page 25 of the California
comment letter).  California requests similar flexibility as provided to
other areas of the country.

EPA Response:

EPA recognizes that using county level emissions can have limitations in
areas with geographically large counties.  However, the Agency also used
information from the nine factors as well as additional information from
the State to assess whether partial county designations were
appropriate.  For example, in the case of Placer County EPA has
determined it is appropriate to designate only a portion of that county
based on information such as topographical features and locations of
emission sources.  As noted above, the CES is one analytical tool that
EPA has used in conjunction with other information as appropriate.  The
CES is designed and intended to assess the relative contributions only
within a specific geographic area.  Just as it is not appropriate to
consider a county within metropolitan New York City and a county within
metropolitan Los Angeles as equal in all respects, it is also not
appropriate to compare CES values between different nonattainment areas.

Delaware:

EPA has relied heavily on the CES in evaluating this factor, using CES
as an arbitrary and inadequate means to evaluate transport, and
apparently putting much weight on the CES in their analysis.  First, the
CES utilizes 2005 National Emission Inventory (NEI) emissions data,
which completely misrepresents Delaware emissions.  Second, tools such
as the CES should be considered only when more sophisticated tools like
modeling are not available.  EPA Clean Air Interstate Rule (CAIR)
modeling has already demonstrated that the PM2.5 transport problem is a
regional problem, and explicitly demonstrates that Delaware does not
significantly contribute to the Philadelphia Combined Statistical Area
(CSA) problem.  The CES indicates that New Castle County impacts the
Philadelphia area more than any other county, and the Pennsylvania CAIR
modeling indicates that the entire State of Delaware does not contribute
significantly to any part of the Philadelphia CSA (i.e., they reach
opposite conclusions)

EPA Response:

The 2005 NEI was used for the CES calculation because it was the most up
to date inventory EPA had at the time.  EPA believes that the inventory
is sufficiently accurate and appropriate for this purpose because it
reflects information submitted by States concerning emission sources
within their boundaries.  In addition, although not directly involved
with the CES calculation per se, EPA invited States to submit further
information regarding emission reductions since 2005 to be considered as
part of the designation process.  The CES was intended to be a screening
tool to provide an initial evaluations of areas suitable for inclusion
within a nonattainment boundary.  Additional information such as that
recommended by EPA in its guidance document was taken into account to
better refine the final decision.

The purpose of the CAIR modeling was to assess the contribution of
interstate transport under Section 110 (a)(2)(D) of the Clean Air Act.
The purpose of the CES was to provide an initial evaluation of counties
possibly contributing to the violating monitor concentrations within the
Philadelphia CSA.  These two tests were implemented to assess two
different problems, the first being long-range interstate transport as
opposed to the second, which was the contribution from a county to the
nearby area.  Under section 107(d), EPA must designate the nearby areas
that contribute to violations of the NAAQS.  Interstate or long range
transport is addressed under other provisions of the CAA.

A CES value is interpreted as the magnitude of contribution a county has
on any violating county within an area.  This may mean that a high CES
value may indicate that a county is affecting itself if it also contains
a violating monitor as is the case with New Castle, DE.  EPA considered
many sources of information when determining whether to include New
Castle, DE as part of the Philadelphia CSA including its inclusion in
the current annual PM2.5 nonattainment area and its close proximity to
the city of Philadelphia.

Iowa:

The CES methodology is incapable of resolving scales finer than the
county level, utilizes data during periods without a violation of the
24-hour PM2.5 NAAQS, and is based upon unrepresentative speciated data.
The boundaries should be determined based upon the analyses utilizing
data corresponding to the nonattainment design values, 2005 – 2007.
County-scale data as aggregated in the CES analysis is insufficient to
resolve the impacts of the sources adjacent to the monitors and results
in arbitrary county boundaries.

EPA Response:

The Agency used county level emissions data because that was the finest
resolved data available.  This level of detail was sufficient for the
analytical purposes in part because PM2.5 and its precursors generally
transport across distances greater than individual counties.  However,
where county sizes varied this may be a limitation of the CES as
acknowledged in the technical support document.  In such situations, the
Agency considered additional sources of information as recommended in
its guidance.

For this purpose, the CES was appropriate for use as a screening tool
with additional data refining the area to better reflect specific
conditions to both Davenport and Muscatine.  For both Davenport and
Muscatine, 2005-2007 data were used.  This has been clarified in the CES
TSD which now lists those areas for which 2005-2007 data were used as
opposed to 2004-2006.  In generalizing the CES so it could be
implemented across the country, default data were used to represent the
speciation concentrations in the violating area based on the area’s
general location within the country.

In the case of Muscatine, EPA recognizes that using default data may not
specifically represent the actual speciation profile for the area.  The
default values represented the average profile for the region containing
the violating monitor which EPA felt served as a valid substitution for
lacking speciation data.  For this case, the Agency relied on data from
the State to better clarify the specific circumstances associated with
both the Davenport and Muscatine areas to make its final designation
decision.

Kentucky:

The Commonwealth was surprised to learn that EPA had employed the use of
a “contributing emissions scoring” process to evaluate counties for
emissions contributions to an area attainment problem.  At no time
during States’ development of recommendations did EPA offer
information concerning this methodology.  Further, EPA did not afford
the States the opportunity to provide input on the appropriateness of or
the science behind this methodology.  Information on this methodology
only became available in August 2008, after recommendations were done.
This approach was revealed in EPA’s comments on Kentucky’s
recommended PM2.5 Boundary Designation December and June submittals.
Taking this approach, especially at such a late date, is not only
contrary to boundary guidance provided to States by EPA, but insults the
established designation process which allows States to use their
thorough knowledge of the monitoring network and local and regional
circumstances to make those designations.  A brief description and a
link to the CES TSD, which consists of over 1,000 pages of information,
were provided in EPA’s comments.

EPA should provide all documentation and a step-by-step process report
that shows the calculations of the CES for each county in Kentucky that
EPA proposes to be nonattainment.  The development of the CES appears to
involve a large number of assumptions, data, and calculations, and it is
not practicable to expect Kentucky to be able to verify the accuracy of
each step without the supporting documentation and processes.  Due to
the number of errors contained in the August 19, 2008 letter, Kentucky
feels that it is imperative to review the process of developing the CES
for the areas proposed for nonattainment by EPA.

EPA Response:

The concepts utilized in the CES were presented at the Regional and
State designations meeting held in Chicago in June 2007.  The CES served
to provide an initial evaluation of what potential  areas are
contributing.  It incorporated forms of information recommended in
EPA’s guidance to preliminarily determine contributing counties which
potentially affected the ambient PM2.5 concentrations at violating
monitors on high days.  EPA has given the State the opportunity to
comment on the CES through the 120 day letter process which the State
has availed itself of here.

The CES technical support document stated that the technique had several
limitations which the States would supplement with additional
information based on the results from the 9-factor analysis.  Thus, the
CES score acted as one tool that was not used to determine the final
outcome but as an initial piece of information from which additional
data from the 9-factor analysis and other analyses submitted to EPA by
the States could be used to making a more informed decision.

Michigan:

The State maintains that the CES calculation is a complicated and
obscure analysis of air pollution concentrations across Michigan.
Ambient values clearly are the best representation of actual
environmental conditions in areas of concern.  The CES calculation used
to determine the daily PM2.5 nonattainment areas is much more complex
than the version used previously for the annual PM2.5 designations.  The
Michigan Department of Environmental Quality (MDEQ) is concerned about
the extensive use of assumptions and weighting factors, all of which
culminate in propagation of error in the final result.

EPA Response:

Michigan’s theory is that EPA should only use monitoring data to
promulgate designations.  Obviously, violating monitors indicate where
there violations.  However, to evaluate nearby areas contributing to
those violations, EPA believes that it is necessary to evaluate other
forms of information.  Therefore, EPA has recommended consideration of
different types of information as laid out in the guidance.  The CES is
intended to be another method to evaluate several of these types of
information.

The CES aggregates data from some of the types of information
recommended in EPA’s guidance.  The tool provides an estimate of the
contribution a particular county has on a violating county.  It does not
attempt to characterize air pollution concentrations across an area.  It
utilizes air pollutant concentrations at violating sites to determine
which days to examine more closely and use a series of weighting factors
to determine which counties could possibly contribute to the violation.

The limitations of the CES have been discussed in the TSD.  The Agency
has given States the opportunity to submit additional information
specific to their areas to make a better informed decision.  Although
the CES influenced the Agency’s decision, it served as one tool out of
many whose information was utilized to determine potential nonattainment
area boundaries.

Utah:

The State indicates for the CES that since there is no documentation of
the actual analysis itself, but only conceptual descriptions of the
process at the web link provided by the Agency, one assumes this was an
analysis done for all of the nonattainment areas in the country.  The
State continues with concerns with the validity of the CES with respect
to the Wasatch Mountains as a topographical issue.

EPA Response:

EPA notes that the CES scores that were provided for every proposed
nonattainment area across the nation do not provide definitive answers,
but do provide a useful screening analysis for the areas.  The EPA does
not disagree that the CES screening analyses have limitations especially
for areas in the western U.S.  The CES information was an additional
analytical tool in EPA’s technical analysis.  The following is
extracted from section 3 “Limitations” of the CES reference
document:

“Topography also affects the CES outcome.  For example, mountain
ranges can act as barriers to transported emissions as well as
potentially limiting the size of the region considered when calculating
the urban increment.  The CES cannot adequately account for the effects
of mountainous terrain which would essentially split a county into
different parts, each having their own potentially unique effect on the
violating county.  A more in-depth discussion of these limitations is
contained within the “Methodology Details" section of this document.
These potential deficiencies can be overcome on an area-by-area basis by
using supplemental information, such as population density, commuting
patterns, more detailed or localized weather data, and topography
data.”

In addition to the information provided in the Agency’s letter were
web links to specific documentation regarding the development of our
9-factor analysis.  EPA acknowledges that the information was
voluminous.  However, this information helped to inform EPA’s
decisions for the Wasatch Front.

Utah:

The State expressed concerns about using an annual emission inventory
data (in tons per year) rather than an episodic inventory for the
9-factor analysis.  The State is convinced that the wrong inventory data
were used in the CES evaluations, and that EPA drew incorrect summary
information from the annual emission inventory data.

EPA Response:

EPA utilized monthly total emission county level estimates that were
aggregated to represent daily seasonal estimates for the cold and warm
seasons used in the CES.  The Agency believes that these estimates
provide a good basis for generally assessing which counties possibly
contribute to a nonattainment area.

Utah:

EPA ran and provided the results of backwards trajectories from the
National Oceanic and Atmospheric Administration’s (NOAA) Air Resource
Laboratory’s Hybrid Single Particle Lagrangian Integrated Trajectory
(HYSPLIT) model for selected high PM2.5 days (inversion conditions).
Unfortunately, specific model run details were not included in EPA’s
response.  In order to properly interpret the results of the
trajectories, it is critical to know the following:

What meteorological data set was used?

What meteorological data set resolution was used?

What vertical motion scheme was used?

What trajectory start height was used?”

EPA Response:

EPA has already provided this information through the CES TSD.  The data
set used was the Eta Data Assimilation System (EDAS) data set from the
NOAA archives.  It has a 40 km resolution.  The vertical motion scheme
was the model default and four trajectory start heights were used as
detailed in the TSD.

Utah:

All of the available meteorological data sets on the HYSPLIT website
have horizontal resolutions far too coarse to accurately depict a
near-surface air parcel’s trajectory in a cold pool.  The coarse
resolution of the meteorological data does not capture the
topographically driven micro- and meso-scale features of the wind field.
 As mentioned in the pollution rose diagram section, topography controls
the wind during quiescent ridge dominated synoptic conditions.  For this
reason, the backwards trajectories produced by EPA must be removed as a
technical justification for any argument put forth.

EPA Response:

EPA concurs with much of the above statement, but believes that
“topography controls the wind during quiescent ridge dominated
synoptic conditions” is an overstatement of the case.  EPA’s
analysis of the surface wind data collected by the Utah Department of
Environmental Quality (DEQ) indicates that there are often relatively
uniform movements of air across the basin during inversion episodes,
which appear to overlay any micro- and meso-scale features of the wind
field caused by local topography.  This data set is completely
independent of the data used by NOAA to create the EDAS meteorology
files.  It represents an independent assessment of the HYSPLIT results.
This regional motion derived from Utah DEQ data appears to be adequately
represented by the low speed regional movements seen in the HYSPLIT
analyses on inversion days.  Currently, the HYSPLIT results do appear to
have some value, and so do not need to be removed from consideration as
suggested by Utah.

To evaluate the appropriateness of conclusions reached using HYSPLIT
back trajectories, EPA obtained surface meteorological data collected by
Utah DEQ across their monitoring network from EPA’s Air Quality System
(AQS).  Using 1-hour average wind speed and direction for all of the DEQ
met stations (excluding Logan in the Cache Valley); the Agency ordered
the data from north to south.  The monitors used, in north to south
order are:

Brigham City

Harrisville

Washington Terrace

Antelope Island

Syracuse

Badger Island

Bountiful

Salt Air

North Salt Lake*

Beach*

Hawthorne

Magna

West Valley City

Cottonwood

West Jordan

Tooele City*

Herriman*

Highland

Lindon

N.  Provo

Spanish Fork

* Indicates monitor did not operate in all years in the period 2004
through 2008

EPA plotted hourly wind speed and direction from these monitors during
the periods used in the HYSPLIT trajectory analyses shown in Figure 2.
EPA then color coded hourly average wind directions, where blue
indicated wind directions originating from the north (northwesterly,
northerly or northeasterly winds), and salmon represents times with
southerly winds (winds from the southwest, south or southeast).  Winds
from the east or west remained unshaded.

Rather than showing only winds controlled by local topography during
cold pool inversion patterns, the resulting diagrams show basin scale
uniformity in wind direction for much of the basin over much of the
inversion periods.  In addition, for specific monitoring days targeted
by the HYSPLIT back trajectories, the diagrams show wind directions over
the basin consistent with the trajectories generated by HYSPLIT.  Thus
the HYSPLIT results and conclusions are in fact consistent with
independent local wind measurements.

Figure 1 shows the three days used in the HYSPLIT trajectory ending at
midnight on January 13, 2004 (shown in Figure 2).  EPA used the 3-day
HYSPLIT trajectory ending on January 13, 2004 to illustrate a monitoring
day in which winds were blowing from the south, and emissions from Utah
County were seen in the HYSPLIT trajectory to move north into Salt Lake
County.  The third day of the diagram in Figure 1 shows southerly winds
across nearly the DEQ’s entire meteorology network for the morning
hours, and southerly winds in Utah County all day, consistent with the
HYSPLIT trajectory for the day.

Figure   SEQ Figure \* ARABIC  1 . Wind Pattern Diagram for January 11
through 13, 2004.

Figure   SEQ Figure \* ARABIC  2 .  HYSPLIT Back Trajectory for January
13, 2004, all Salt Lake County Monitors.

Figure 3 shows the meteorology data from the Utah Department of
Transportation (DOT) monitor located just north of Point of the Mountain
along I-15.  The monitor shows variable light winds all day, but with
frequent winds from the south through the Point of the Mountain gap
before noon.

Figure   SEQ Figure \* ARABIC  3 .  Meteorology Near the Utah
County/Salt Lake County Line, January 13, 2004.

The second wind pattern diagram in Figure 4 shows the three days used in
the HYSPLIT trajectory ending at midnight on January 22, 2004.  Figure 5
shows this three-day HYSPLIT trajectory to illustrate a monitoring day
in which winds were generally blowing from the north.  The third day of
the wind diagram in Figure 4 shows winds from the north across nearly
the DEQ’s entire meteorology network in the middle of the day,
consistent with the HYSPLIT trajectory.  The Bluffdale UDOT wind data
for the day is shown in Figure 6.  The monitor was not reporting prior
to 9:15 AM, at which time flow through Point of the Mountain was from
the south (downvalley from Utah County to Salt Lake County).  Consistent
with the Utah DEQ network and HYSPLIT, flow in the afternoon hours is
up-valley, flowing south from Salt Lake County into Utah County.

Figure   SEQ Figure \* ARABIC  4 .  Wind Pattern Diagram for January 20
through 22, 2004.

Figure   SEQ Figure \* ARABIC  5 .  24-hour Backtrajectory for January
22, 2004, All Salt Lake County Monitors.

Figure   SEQ Figure \* ARABIC  6 .  Meteorology Near the Utah
County/Salt Lake County Line, January 22, 2004.

The third day of HYSPLIT trajectories EPA utilized were those ending on
January 26, 2006 (figure 8).  This day was again a southerly wind
dominated day.  It was selected because it included more southwesterly
flow than other trajectories, indicating the potential for flow of
Tooele Valley emissions toward Salt Lake City and Ogden, but represents
a day with much more complex wind patterns in the HYSPLIT simulation.
Again, as shown in figure 7, the measurements of the Utah DEQ
meteorology network are consistent with the HYSPLIT trajectory, showing
pronounced flow from the south across the basin prior to midnight on
January 25 through midday on January 26, 2006.  Figure 8 shows the
24-hour backtrajectory from HYSPLIT.

Figure   SEQ Figure \* ARABIC  7 .  Wind Pattern Diagram for January 24
through 26, 2006.

Figure   SEQ Figure \* ARABIC  8 .  24-hour Backtrajectory for January
26, 2006.

Wind data from the Bluffdale Utah DOT monitor for January 26, 2006 is
almost uniformly from the south.  While the Quality Assurance (QA)
status indicator for this data in the MesoWest database is “OK”, the
monitor seems to show a very high level of high winds from due south or
south-southeast during January of 2006, so the data appears to reflect a
bias in the instrument toward southerly winds.  Therefore, that data is
not used here.

With respect to the wind pattern diagrams in Figures 1, 4 and 7 and the
Utah DOT wind measurements at Point of the Mountain, to a greater or
lesser extent, all show some degree of diurnal winds across the Salt
Lake and Utah Lake basins; surface winds across the network are more
often southerly at night and in the morning, with northerly winds most
likely in the afternoon.  This would indicate that the two basins are
acting as a connected valley system.  Generalized basin level winds can
be seen well beyond any degree to which local topography is controlling
winds at any given monitor location.

Subsequent to 2004-2006 (the period over which HYSPLIT trajectories were
calculated for every PM2.5 exceedance day), UDOT meteorology data is
available from the Alpine station along I-15 just south of Point of the
Mountain.  The station location is shown in figure 9.  The Alpine
monitor, on the south entrance to the gap at Point of the Mountain
generally shows much more intense winds than does the UDOT Bluffdale
monitor north of Point of the Mountain.  As an example, figure 10 shows
the winds recorded by the Alpine monitor on January 21-30, 2007.  This
period included the highest PM2.5 days in both Utah County and in Salt
Lake County during 2007.  Winds throughout the period are dominated by
southerly (down valley) winds from Utah County to Salt Lake County.
During the peak days in the period, some degree of up-valley flow occurs
in the middle of several days.  The dominance of downvalley flow at this
site is typical during the inversion periods since March of 2006,
indicating that consistent and significant flow is the usual pattern;
some lesser degree of northerly winds is also typical, indicting the
likelihood of 2-way transport.

Figure   SEQ Figure \* ARABIC  9 .  Utah DOT Alpine and Bluffdale
Meteorology Station Locations.

Figure   SEQ Figure \* ARABIC  10 .  Point of the Mountain Surface
Winds, January 21-30, 2007.

SECTION III:  Technical Analysis

State Comment:  2005 NEI Inadequate

Delaware:

EPA used the 2005 NEI as a basis for evaluating this factor.  The 2005
NEI is not a high quality inventory, as it was not developed in
conjunction with State agencies, nor has it been quality assured by
States.

EPA Response:

EPA believes the 2005 NEI Version 1 was the highest quality emission
inventory available during the 2006 24-hour PM2.5 designations process.
Most of the point and non-point emissions in the 2005 NEI Version 1 were
taken directly from the 2002 NEI Version 3 which was developed in
conjunction with State agencies and underwent thorough QA, including QA
by State agencies.  New emission measurements and estimates were
included in the 2005 NEI Version 1 for Electric Generating Units (EGUs),
mobile sources, and fires because EPA had more recent data and/or models
for these sources (e.g., Continuous Emission Monitoring (CEM) data for
EGUs, new versions of the MOBILE model for mobile sources).  While it is
true that these new emissions data were not developed in conjunction
with State agencies, nor quality assured by States, EPA believes using
these data more accurately characterize emissions than the alternative
of using an older version of the NEI (e.g., 2002 NEI Versions 3) for
these sources.

State Comment:  Determination of contributing areas

Indiana:

Indiana firmly believes that due to the localized influence (urban
excess) of PM2.5, nonattainment boundaries for the 24-hour PM2.5
standard should be limited only to counties that possess a three-year
average ambient monitor-based design value above the standard.  However,
if the only violating monitor within the county is a source-oriented
site, the boundary should be limited to the township in which the
monitor resides.  This is consistent with U.S. EPA designations under
the PM10 standard.

EPA Response:

CAA Section 107(d)(1)(A)(i) provides that nonattainment areas must
include “any area that does not meet (or that contributes to ambient
air quality in a nearby area that does not meet)” the applicable
NAAQS, therefore to limit nonattainment boundaries to only those
counties with monitored-based design values above the standard ignores
the role of contribution from nearby areas mandated by the Act.  In most
nonattainment areas, speciation data indicate significant contributions
from sulfur dioxide and nitrogen oxide sources throughout broader
metropolitan and contributing areas..

With regard to source-oriented monitors, those in Indiana are in areas
that also have other monitors violating the standard (for example in
Illinois).  EPA has found that even source-oriented monitors reflect
substantial contribution from the metropolitan area and beyond.  EPA
does not find the comparison to PM10 appropriate because areas with high
PM2.5 concentrations are more affected by secondary formation.  PM10 and
PM2.5 are different particles, that are often formed from emissions from
different types of sources that may require different control
strategies.  PM2.5 can transport greater distances than PM10.  PM10
nonattainment area boundaries often date back nearly 20 years.

Indiana:

Recognizing that EPA is obligated to consider a county’s contribution
to a downwind monitored violation of the standard, sound evidence must
exist that demonstrates that a county actually contributes to the
downwind violation in order for the upwind county to be designated
nonattainment.  Such evidence should not only be supported by a
culpability demonstration, the culpability of the upwind county, or
portion thereof, must be significant.  Counties that measure air quality
below the standard, and are not proven to be significantly culpable for
a downwind violation, should be designated attainment.  Counties for
which monitoring data does not exist, and are not proven to be
significantly culpable for a downwind violation, should be considered
unclassifiable and designated attainment.

EPA Response:

EPA appreciates Indiana’s acknowledgement that EPA must consider the
contribution of areas as part of its decision-making on nonattainment
area boundaries.  However, Indiana suggests application of a burden of
proof that is not required under section 107 of the Act which is
inconsistent with the role of designations as distinct from attainment
planning.  In many respects, the role of designations is to define the
planning area for the State to use in planning for achieving air quality
standards.  While EPA must make judgments of nonattainment area
boundaries based on the best available evidence, the expectation is that
the promulgation of designations will trigger more thorough analyses of
impacts and potential controls of sources as part of the process of
formulating and adopting an attainment plan.  Indiana seems to seek a
requirement for analyses of impacts of sources typical of an attainment
plan analysis in order to determine what area should be subject to such
an attainment planning requirement.  Such an approach would be
inconsistent with the structure of the Act.  Furthermore, Indiana in
effect seeks for the Agency to be bound to designate potentially
contributing areas as attainment even if the best available evidence
indicates that the area contributes to the violations, merely because
the available evidence is insufficient to meet the burden of proof that
Indiana seeks for the Agency to apply.  Again, such an approach would be
inconsistent with the mandates and structure of the Act.  The Agency
construes “contribution” to allow a case-by-case approach in
determining what level of contribution warrants inclusion in a
nonattainment area.  Each area has unique facts which must be analyzed.
Rather than adopting specific materiality requirements or bright-line
tests, the Agency reasonably developed an analytical approach to
evaluate whether emissions in a particular area contribute to violations
in another nearby area.  Nothing in Section 107(d) requires the
culpability demonstration suggested by Indiana.  The definition of
“nonattainment” specifically includes any area that “contributes
to” violations of NAAQS in a nearby area, not only those that
literally cause such violations.  Ambient PM2.5 at every monitor
reflects the cumulative impacts of many types of emissions from many
sources, near and far, that result in primary and secondary formation of
particles.  Imposing a culpability analysis would frustrate the goal of
the statute by narrowing its application.  The Agency’s analytical
approach was designed to evaluate contribution in a qualitative way by
considering the facts and circumstances of each area.

Indiana:

Since there are multiple species that comprise PM2.5, and the portion of
specie contribution varies by season and geographic location, relying
solely on precursor emissions data weighted evenly by species is
inappropriate and does not constitute a culpability demonstration.
Additionally, assuming that mobile source contributions driven by
population density substantiate culpability for a collar county is
erroneous and contradicted by speciation and source apportionment data
available to EPA.

EPA Response:

This comment misrepresents EPA’s approach.  The Agency applied
different weights to the emissions of different pollutants that directly
or indirectly contribute to PM2.5 concentrations, explicitly in
computation of its contributing emission score and also in its
examination of underlying information.  The contributing emission scores
were computed by first estimating the urban increment contributions of
each major PM2.5 component, estimated separately for each metropolitan
area and separately for warm versus cold months.  The relative
percentages for each component were then used as weighting factors to
give the highest score to counties that had high emissions of the most
important pollutants.  Since this approach appears to match the approach
that Indiana recommends, it appears that Indiana endorses the
contributing emission score as a tool for judging relative contributions
of different counties.

Indiana also appears to misrepresent the approach EPA took regarding
mobile source emissions.  In general, one of the most important
indicators of contribution by a county is the emissions within that
county.  Commonly, these data strongly indicate contribution of relevant
counties, and information regarding the location of mobile sources and
their emissions had little influence on EPA’s judgment.  Nevertheless,
since some mobile source control programs are applied based on the home
station of the vehicle, one factor in judging the contribution of a
county is the number of vehicles that are housed in the county.  For
example, many vehicles registered in Lake County, Indiana, incur much of
their emissions in Cook County, Illinois; these vehicles represent Lake
County sources that are contributing to air quality problems in Cook
County.  Mobile sources are important contributors to PM2.5
concentrations, and population data can be an important indicator of the
home station of these sources.  Mobile source use in an area, as
reflected in information like the number of drivers and vehicle miles
traveled (VMT) in an area, is relevant to determining whether an area
contributes to violations in nearby areas.  Similarly, the number of
commuters in a county who drive to another county, the percent of total
commuters in each county who commute to other counties, and their
destinations is important to the analysis.  Information about commuting
patterns may indicate where emissions from mobile sources might actually
be occurring, and therefore the degree to which drivers based in one
area are contributing emissions to another area.

Indiana:

In its October 2, 2008 letter, Indiana included an evaluation of fine
particulate matter nonattainment area boundaries.  Indiana provided this
information in Attachment D of its letter in response to the Agency’s
August 2008 recommended designations.

EPA Response:

Indiana focused on information it believes justifies excluding selected
counties or partial counties from the respective nonattainment areas.
Nevertheless, the information that Indiana provided in Attachment D is
similar to information that EPA has reviewed.  Therefore, this
information does not justify a change in the boundaries of the pertinent
nonattainment areas.

State Comment:  Relevance of jurisdictional boundaries and consistent
boundaries for PM2.5, PM10, and other nonattainment areas

California:

One of U.S. EPA’s goals in designating nonattainment areas in
California was to achieve a degree of consistency with existing ozone
and PM10 nonattainment areas.  Application of this goal in California
led to differences between the State’s recommended nonattainment areas
and EPA’s proposed designations.  EPA expanded many of the State’s
recommended PM2.5 nonattainment areas boundaries to match 8-hour ozone
nonattainment area boundaries.  However, we do note areas throughout the
country where EPA proposed PM2.5 nonattainment area designations are not
consistent with existing 8-hour ozone nonattainment area boundaries.
Examples are shown in Table 2 on page 3 of the California comment
letter.

Some of the areas in Table 2 were excluded based on the nature of the
pollutant.  PM2.5 is comprised of both primary and secondary components;
the primary being more localized.  The California Air Resources Board
(CARB) requests that EPA recognize the technical basis for different
boundaries for regional ozone and localized PM2.5.

EPA Response:

EPA looked at the violating monitors and sources in nearby areas
potentially contributing to the violations.  As described above,
residential woodburning and transportation were identified as the
principal sources based on speciation data and, therefore, nonattainment
areas were intended to capture population centers, major transportation
corridors, and stationary sources in the area.  The Agency revised the
eastern boundary of the Sacramento, Sutter/Yuba and Butte nonattainment
areas.  Rather than extending the boundary to the ridgeline of the
Sierra Nevada Mountains or the county line, which was consistent with
the ozone nonattainment boundaries where they existed, the eastern
boundaries were redefined based on the topography of the Sierra Nevada
Mountains and the height of the winter time inversion layer.
Considering this physical boundary, which also resembles the California
Air Basin boundary for the Sacramento Valley, EPA defined the eastern
boundaries with township and range lines to capture this topographical
boundary, as well as the major population centers and transportation
networks.

Delaware:

EPA indicated that New Castle County historically has been part of the
Philadelphia nonattainment area for ozone and PM2.5, and that Delaware,
Pennsylvania, and New Jersey have a long history of working
cooperatively with ozone and particulate matter (PM) attainment
planning.  This statement by EPA is not in the proper context of factor
8.  While these States do work cooperatively together, no cooperative
air planning effort to date has occurred as a result of being in a
common nonattainment area.  These States have historically worked
together only as part of larger efforts, like the Mid-Atlantic/Northeast
Visibility Union (MANE-VU) and the Ozone Transport Commission (OTC).
Not a single control measure has been developed as a cooperative effort
amongst these States outside of MANE-VU and OTC context.

EPA Response:

Delaware has conceded that it has worked with the other States in the
Philadelphia area as part of MANE-VU and the OTC.  Therefore, as stated
in its August 18, 2008 letter, EPA does not anticipate that including
New Castle County as part of the Philadelphia nonattainment area for the
2006 PM2.5 NAAQS will be an undue burden on Delaware.

Delaware:

In addition, no CSA scale efforts are necessary relative to planning for
the 2006 PM2.5 standard.  This is because the New Castle County
non-attainment problem is separate and distinct from the Philadelphia
problem, and the only commonality is transport, which is regional, not
local, in nature.  Factor 8 supports New Castle County as a separate
non-attainment area from the rest of the Philadelphia CSA, and the
continuation of larger regional efforts to develop control strategies
and address transport.

EPA Response:

EPA has determined that emissions from New Castle County contribute to
downwind fine particulate concentrations in the Philadelphia CSA.  New
Castle County’s SO2 emissions are the highest of all the counties in
the Philadelphia-Wilmington area.  The predominant wind direction in the
Philadelphia-Wilmington area is from the southwest.  The violating
monitors in the Philadelphia-Wilmington area, in Delaware, Chester,
Camden, and Philadelphia Counties, are downwind of both northern and
southern New Castle County.  High PM2.5 days at the Chester County
monitor are from the south-southwest, southeast, and south-southeast.
Winds from the southeast and south-southeast would pass through New
Castle County.  Therefore, CSA-scale planning is necessary.

Indiana:

When designating areas under the annual PM2.5 standard, EPA relied on
guidance and criteria established for the 1-hour ozone and carbon
monoxide NAAQS.  Section 107(d)(4)(A)(iv) is the only citation of the
CAA that references a Metropolitan or Consolidated Metropolitan
Statistical Area (MSA or CMSA) boundary as the presumptive boundary for
a nonattainment area.  However, not only is this citation limited to
ozone and carbon monoxide areas, it is limited to areas classified as
Serious, Severe, or Extreme under Subpart 2 of the CAA.  EPA relied on
Subpart 1 of the CAA when it designated areas under the annual PM2.5
standard and no areas were classified.  Section 107(d)(4)(B) of the CAA
defines a nonattainment area for PM10 based on a violation of the
standard, suggesting that the boundary should be limited to the
jurisdiction where the violation occurs.

EPA Response:

Contrary to the commenter’s claim, EPA did not rely on guidance and
criteria established for the 1-hour ozone and carbon monoxide NAAQS in
promulgating PM2.5 designations.  Instead, EPA issued separate guidance
for designations for PM2.5 and conducted PM2.5-specific evaluations
(including use of a weighted emission score that was not used for ozone)
to determine appropriate boundaries for PM2.5 nonattainment areas.  As
explained in EPA’s guidance, PM2.5 arises from a combination of
distant sources and urban scale sources (including sources very nearby
and sources elsewhere in metropolitan areas).  Ozone also arises from
both distant sources and urban scale sources, and EPA’s guidance on
PM2.5 designations notes the similarity of approaches for designating
the two pollutants.   This similarity in approaches does not mean that
EPA is simply applying criteria contained in section 107(d)(4)(A)(iv)
(applicable to ozone designations for areas with specified
classifications) in promulgating PM2.5 designations.  To the contrary,
EPA acknowledged in its guidance for the 2006 PM2.5 designations that
when determining boundaries in urban areas for the 1997 annual PM2.5
NAAQS, it had applied a presumption that they should be based on
Metropolitan Statistical Area (MSA) or Consolidated MSA (CMSA)
boundaries.  However, we specifically stated that “[f]or the PM2.5
24-hour NAAQS, EPA is establishing no such presumption.”  The Agency
did note that it anticipated that the same boundaries established for
the annual PM2.5 standard, where that presumption might have been
applied, may also be appropriate for implementing the 24-hour PM2.5
NAAQS because the same sources of emissions may also be contributing to
violations of the 24-hour standard based on emissions and air quality
data and meteorology.

EPA continues to believe that C/MSA boundaries may be relevant and
appropriate to consider in making PM 2.5 designations because of the
distances that PM2.5 and its precursors can be transported.  Therefore,
“nearby areas” for PM2.5 are not only those in the immediate
vicinity of a violating monitor.  Like ozone, a significant fraction of
PM2.5 particles results from secondary formation of particles in the
atmosphere due to emissions of different precursor chemicals from a
variety of nearby and distant sources.  EPA’s analysis indicated that
the local component of particles at a violating monitor were likely to
result from a combination of sources throughout the urban area.  Thus,
it was logical to analyze C/MSAs as potential boundaries to ensure
inclusion of relevant sources in evaluating nonattainment area
boundaries.

When Congress enlarged the presumptive boundaries for ozone and carbon
monoxide nonattainment areas to the C/MSAs, EPA had already designated
areas for ozone and carbon monoxide.  Section 107(d)(4)(A) explicitly
required that those already designated areas be enlarged to full C/MSA
boundaries by operation of law.  By making this change, Congress
presumably recognized that artificially small nonattainment areas could
exclude sources that should be subject to SIP requirements.  While
Section 107(d)(4)(A) does not directly apply to PM2.5 designations, it
provides a logical basis for EPA to suggest a comparable analysis for
PM2.5, which, like ozone, is a pollutant that results from a broad range
of urban sources.  If Congress intended to prohibit States or EPA from
using C/MSAs as appropriate geographic starting points for evaluating
potential contributions to PM2.5 violations, Congress could have done
so.  Silence in the CAA on the subject does not prohibit using C/MSAs as
potential boundaries, but rather leaves to EPA the task of determining
how to draw appropriate nonattainment boundaries.  Thus EPA considered
it appropriate to analyze counties within the C/MSA boundary as well as
a ring of counties outside the C/MSA to determine potential contribution
and therefore inclusion in the nonattainment area. Additionally, the
fact that EPA declined to classify areas for PM2.5 when designating
areas under the annual PM2.5 standard and relied in its implementation
rule instead on Subpart 1 (CAA Section 171 – 179B) has no bearing on
whether EPA has the discretion to consider any potential group of
counties, such as those within the C/MSAs, for analysis purposes.
Further, EPA is not promulgating the 2006 PM2.5 designations under
Section 107(d)(4)(B) but instead under Section 107(d)(1).  Therefore,
the provisions contained in Section 107(d)(4)(B) do not limit EPA’s
authority to designate nearby contributing areas, otherwise mandated by
the CAA, nor otherwise limit its analysis of potentially contributing
counties.

Indiana:

Both the annual and 24-hour PM2.5 standards are a revised version of the
PM standards.  Therefore, Indiana firmly believes that PM2.5
designations should be consistent with designations under the PM10
standard.  Since U.S. EPA is relying on the nonattainment boundaries for
the annual PM2.5 standard to serve as the presumptive boundaries for the
24-hour PM2.5 standard, and the presumptive boundaries would be more
representative of ozone as the pollutant, U.S. EPA must reconsider the
criteria and presumptive boundaries prior to proceeding with final
designations under the 24-hour PM2.5 standard.

EPA Response:

As explained above, EPA did not apply any presumption that annual
nonattainment area boundaries would serve as the presumptive boundaries
for the 24-hour standard, only that we anticipated that the annual PM2.5
boundaries, which were based upon a number of relevant factors, might
also be appropriate for the 24-hour PM2.5 boundaries.  EPA is deciding
the boundary of each 24-hour PM2.5 nonattainment area on its own merits.
 EPA’s decision to exclude Dubois County from the Evansville 24-hour
PM2.5 nonattainment area, in contrast to its inclusion in the annual
PM2.5 nonattainment area, illustrates the fact that EPA is making
independent decisions on the boundaries of nonattainment areas for the
2006 air quality standards based on current information about potential
contributions to violating monitors.

Nevertheless, in most cases, areas that contribute to violations of the
annual standard also contribute to violations of the 24-hour standard.
For both standards, violations in the eastern United States generally
reflect significant quantities of sulfate, nitrate, and organic
particulate matter.  These violations result from a range of sources,
including sources at great distances (most notably power plants,
yielding regionally distributed sulfate and nitrate concentrations),
sources within a few kilometers, and sources emitting either particles
or precursors or both within the broader metropolitan area.
Consequently, the requirement of the Act, dictating that nonattainment
areas shall include nearby contributing areas as well as the area
actually observing a violation, is to include much if not all of the
metropolitan area in the nonattainment areas for both standards.  It was
thus appropriate for EPA to analyze counties within and just outside of
C/MSA boundaries to determine whether such areas were contributing to
monitored violations.

Preexisting PM10 nonattainment boundaries generally have little, if any,
relevance to what boundaries would be appropriate for PM2.5.  The PM10
NAAQS involves a different standard, with different indicator particles,
different concentrations levels, resulting from different sources that
may require different control strategies.  These boundaries were
generally promulgated almost 20 years ago, for a completely different
NAAQS.

Indiana

Section 107(d)(4)(B) of the CAA defines a nonattainment area for PM10
based on a violation of the standard, suggesting that the boundary
should be limited to the jurisdiction where the violation occurs.  Both
the annual and 24-hour PM2.5 standards are a revised version of the PM
standards.  Therefore, Indiana firmly believes that PM2.5 designations
should be consistent with designations under the PM10 standard.

EPA Response:

Section 107(d)(4)(B) explicitly applies to designations for PM10, not to
designations for any other form or constituent of particulate matter.
Therefore, this section does not govern designations for PM2.5.  Given
that most designations for PM10, including all the designations for PM10
in Indiana, took effect pursuant to section 107(d)(4)(B)(i) (reflective
of pre-existing Group I areas), not section 107(d)(4)(B)(ii), and given
that no Group I areas exist for PM2.5, the Act cannot reasonably be
interpreted to provide for promulgating PM2.5 designations pursuant to
section 107(d)(4)(B).

The comment regarding designations for PM10 is not germane and
misinterprets this provision of the Act.  Section 107(d)(4)(B) applies
explicitly to designations for PM10, and the Act does not provide for
this section also to apply to other pollutants such as PM2.5.  In
addition, section 107(d)(4)(B)(ii) need not be interpreted to dictate a
different legal structure than section 107(d)(1) (“Designations
generally”).  For PM10, just as for PM2.5, the planning areas that
became the nonattainment areas included the violating areas but also
included contributing areas.  For example, the nonattainment area in
Northwest Indiana included the entirety of four cities in Lake County,
notwithstanding the fact that monitoring data indicated violations in
only a portion of that area.  Although in Indiana the PM10 designations
were promulgated under subsection (i) rather than subsection (ii) of
Section 107(d)(4)(B), EPA promulgated PM10 designations elsewhere that
reflected its view that PM10 nonattainment areas are to include
contributing areas as well as violating areas.  The difference between
the size of most PM10 nonattainment areas and the size of most PM2.5
nonattainment areas thus reflects differences in the typical size of the
contributing area and not to any legal differences as to whether
contributing areas are to be included.  Thus, PM10 which consists of
larger particles that more rapidly settle to the ground will generally
be caused by sources closer to a violating monitor, while PM 2.5 which
consists of smaller particles that can be transported greater distances
will more likely see contributions from throughout a metropolitan area.
In fact, the distribution of PM2.5 bears more similarity to the
distribution of ozone than it does to the distribution of PM10, which is
the primary reason that the PM2.5 nonattainment areas generally resemble
the size of ozone nonattainment areas more than they do the PM10
nonattainment areas.

Iowa:

The use of arbitrary political boundaries to delineate the extent of the
proposed nonattainment boundaries is not consistent with EPA’s
guidance.  In the June 8th, 2007, “Area Designations for the Revised
24-Hour Fine Particulate National Ambient Air Quality Standards”
guidance document, EPA stated that the Metropolitan Statistical Area
presumptive boundary for areas violating the annual standard would not
apply to areas violating only the 24-hour standard.  In effect, no
presumptive boundaries are to be assumed for any nonattainment area in
Scott or Muscatine Counties.  The EPA has given no technical
consideration to sub-county boundaries.  All technical analyses
completed by EPA, for example the use of the CES analysis, have relied
upon data aggregated to the county level.  In effect, this approach has
elevated the importance of the jurisdictional/political boundary factor
above the other eight factors.  This gives rise to the conceptual model
of which sources and what conditions lead to PM2.5 formation in a given
area.

EPA Response:

EPA emphasizes that it did not rely on boundary presumptions in its
120-day letter to Iowa, nor did EPA use it to consider the
jurisdictional boundaries factor to override other important factors to
be more significant than others.  To the contrary, the 120-day letter
included EPA’s application of all nine factors to the area in stating
its intent to establish the county boundaries.  The letter also stated
that EPA was considering other boundaries, including a partial county
boundary, and sought information on whether different boundaries would
be appropriate.  Finally, and most significantly, EPA’s promulgation
does establish a partial county boundary for both areas, based on a
case-specific application of the nine factors and information provided
by the state.  However, EPA does not agree that the relatively small
area covered by the partial city boundaries recommended by Iowa is
supported by the available information.

West Virginia:

EPA’s analysis correctly identifies relevant State and county
jurisdictions.  But that analysis fails to provide any justification
whatsoever for adding part of Mason County to the nonattainment area.
Rather, the text notes that the ozone nonattainment area includes Cabell
and Wayne County (WV) and Boyd County (KY).  It is puzzling that EPA
ostensibly performed a similar 9-factor analysis for both ozone and
PM2.5 and reached different conclusions, even though NOX is a common
precursor.  It is also troubling that, prior to the 2005 annual PM2.5
designations, EPA had generally based nonattainment boundaries on county
and Metropolitan Statistical Area boundaries rather than arbitrarily
adding “islands” such as the portion of Mason County.  EPA provides
no support for how such an isolated tax district bears any relevant
jurisdictional relationship to the remainder of the nonattainment area.
Moreover, its inclusion within the nonattainment area presents an
additional and unnecessary burden on KYOVA because it must be addressed
under transportation conformity requirements even though no air quality
benefits result.

EPA Response:

Mason County is not part of KYOVA, the metropolitan planning
organization for Cabell and Wayne Counties and the City of Huntington in
West Virginia, and Lawrence County and the City of Ironton in Ohio.
However, EPA believes that including a portion of Mason County in the
Huntington-Ashland nonattainment area will not pose an undue burden on
KYOVA.  In fact, under the 1997 PM2.5 NAAQS, KYOVA has successfully
completed its transportation planning with the inclusion of the Graham
Tax District in Mason County.

EPA included a portion of Mason County in the Huntington-Ashland area
because it determined that emissions from two large sources in that tax
district currently contribute to violations of the 2006 24-hour PM2.5
NAAQS in the Huntington-Ashland area.  Mason County, which is adjacent
to Cabell County, has two large electric generating units.
Meteorological data shows that on one-third of the days in 2004-2006
with monitored 24-hour PM2.5 values greater than 35 and 40 µg/m3 in
Cabell County, winds came from the north-northeast.  This data suggests
that emissions from the north-northeast, i.e., from Mason County, WV
likely contribute to the 2006 24-hour PM2.5 NAAQS violations.   However,
since Mason County did not rank highly for other factors EPA concluded
that including only the Graham Tax District in Mason County in the
nonattainment area would capture the bulk of emissions in that county
that are contributing to the monitored violations.

West Virginia:

EPA identifies the State boundary between Ohio and West Virginia as the
major jurisdictional boundary.  Further, the Agency encourages the two
States to work collaboratively to reduce emissions.  The West Virginia
Department of Environmental Protection (DEP) agrees that cooperation
will facilitate meeting the air quality standard.  EPA goes on to note
that the former 8-hour ozone nonattainment area included Wood County
(WV) and Washington County (OH).  However, EPA provides absolutely no
support for the inclusion of any portion of Pleasants County based upon
jurisdictional considerations.  DEP continues to pursue litigation
concerning EPA’s inclusion of the Grant Tax District (Pleasants, WV)
in the PM2.5 annual standard designations.  We strongly believe that EPA
has inappropriately proposed inclusion of this district in the 24-hour
PM2.5 Parkesburg-Marietta nonattainment area.  DEP encourages EPA to
reconsider and exclude the entire county of Pleasants from the
nonattainment designation.

Pleasants County is not part of the Parkersburg MSA.  Therefore, it is
not within the jurisdiction of the Wood-Washington-Wirt Interstate
Planning Commission (WWW), the transportation planning organization.
Moreover, its inclusion within the nonattainment area presents an
additional and unnecessary burden on WWW because it must be addressed
under transportation conformity requirements even though no air quality
benefits result.

EPA Response:

Pleasants County is part of the Parkersburg-Marietta-Vienna MSA, which
also includes Wood and Wirt Counties in West Virginia and Washington
County in Ohio.  However, Pleasants County is not part of the WWW, which
is the metropolitan planning organization for Wood County, West Virginia
and portions of Washington County, Ohio.  EPA believes that including a
portion of Pleasants County in the Huntington-Ashland nonattainment area
will not pose an undue burden on KYOVA.  In fact, under the 1997 PM2.5
NAAQS, WWW has successfully completed its transportation planning with
the inclusion of the Grant Tax District in Pleasants County.

EPA included the Grant Tax District portion of Pleasants County in the
Parkersburg-Marietta nonattainment area because emissions from three
large sources in the Pleasants County, just over the border from Wood
County, contribute to violations of the 2006 24-hour PM2.5 NAAQS in the
Parkersburg-Marietta area.  These sources are the Pleasants Power
Station, the Willow Island Power Station, and the Cabot Corporation Ohio
River Plant.  Due to these large sources, Pleasants County has the
highest emissions in the West Virginia portion of the
Parkersburg-Marietta-Vienna MSA.  Its SO2 emissions are nearly 10 times
higher than those of Wood County, which contains the violating monitor.
Furthermore, Pleasants County’s NOX emissions are more than twice
those of Wood County and its total PM2.5 emissions are close to two
times higher than Wood County’s.  Therefore, EPA determined that it is
appropriate to only include the portion of Pleasants County containing
these sources, namely the Grant Tax District, in the
Parkersburg-Marietta nonattainment area.

State Comment:  Consideration of topography

Kentucky:

The response for the Geography/topography factor was inconsistent
throughout the entire response.  EPA determined in each area that there
were “no geographical or topographical barriers significantly limiting
air pollution transport within its air shed.” However, despite the
common factor, the answer alternated between each factor as to whether
or not the absence of topographical and geographical barriers
“contributed to violations in the area” or “did not play a
significant role in the decision-making process.” The lack of a
geographical/topographical barrier should either benefit an area or
cause a problem.

EPA Response:

The geography/topography analysis evaluated the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the area in question.  The nonattainment
areas in Kentucky do not have any geographical or topographical barriers
significantly limiting air-pollution transport within its air shed.
Therefore, this factor did not play a significant role in the
decision-making process.  By “contributed to violations in the
area,” EPA, in this case, was conveying that no topographical features
interfered with or cut off the transport of relevant pollutants from
nearby emissions sources.  Kentucky is correct, however, that the
absence of topographical features impeding contribution can support the
conclusion that such contribution occurs.

State Comment:  Consideration of Counties and Time Intervals for
9-Factor Analysis (KY)

EPA used a list of counties including some that were outside of the MSA
for certain factor analyses, and would exclude these same counties in
different factor analyses.  It seems inconsistent to make comparisons
with one population of statistical data, and then continue comparisons
with a different population of statistical data.  This comment also
applies where EPA used certain time intervals for one factor analysis
and a different time interval in another factor analysis.

EPA Response:

For the CES methodology, EPA ran calculations on counties extending out
a large distance from each violating monitor.  The CES tables shown in
EPA’s intended designation letters may not include all counties
considered in the 9-factor analysis, but they include those counties
having factors which indicate they should be candidates for a
nonattainment status.  In evaluating each of the nine factors for each
potential nonattainment area, our intended designation letters showed
the counties for which the Agency intended to designate nonattainment
for the 2006 24-hour PM2.5 NAAQS, and in many cases, other surrounding
counties where a comparison seemed relevant.  EPA’s exclusion of
particular counties from a particular factor data table does not mean
those counties were excluded from our analysis, only that we considered
those counties less relevant for that factor.  With regard to the time
intervals considered for each factor, note that the Agency utilized the
latest available data sets for our analyses.

State Comment:  Documentation of VMTs

Regarding the VMTs that EPA has utilized in their analysis, Kentucky has
been unable to document the basis for the development of this data.  EPA
has provided the spreadsheet containing the VMT numbers used in the
analysis, but to date has been unable to provide Kentucky with the
supporting documentation in the development of these numbers.  Since the
numbers used in Kentucky’s previous recommendation submittals were
developed by area agencies responsible for transportation conformity, we
must insist that the numbers in our previous submittals are more
reflective of the transportation sector in these areas.

EPA Response:

EPA consistently used county-level population and VMT growth estimates
for all areas of the country.  For 2005 a full VMT database at the
county, roadway type, and vehicle type level of detail was developed
from Federal Highway Administration (FHWA) information.  For States and
local areas that submitted VMT data that were incorporated in the 2002
NEI, the 2002 NEI VMT data were grown to 2005 using growth factors
developed from the FHWA data, and these grown VMT data replaced the
baseline FHWA-based VMT data.  The resulting VMT database prepared for
2005 include data for all 50 States, the District of Columbia, Puerto
Rico, and the Virgin Islands for each of the 12 Highway Performance
Modeling System (HPMS) functional roadway types and the 28 MOBILE6
vehicle classes, for a total of 336 records per year per county.  The
data were prepared in the NMIM National County Database BaseYear VMT
table format.  At this point, States had opportunity to submit 2005
estimates that replaced EPA's estimates for 2005.

SECTION IV:  Power Plant Issues

State Comment:  Power plant counties

Several States believe that EPA should reconsider its determination that
counties and/or townships with significant power plants should be
designated as nonattainment based on the cause or contribute rationale.
The existence of an electric generating unit in a township should not be
the sole factor in determining nonattainment.  At a minimum, EPA should
consider the size of the power plant and the emission controls it has
implemented.

EPA Response:

The fundamental statutory requirement governing the designations process
is section 107(d) of the Act, which requires the EPA Administrator (or
the Administrator) to designate each area that violates the NAAQS and
any nearby area that “contributes” to the violation.  In the PM2.5
designations process, EPA used 2005 county-level data from the National
Emissions Inventory in evaluating potential contributing counties for
area-specific technical analyses.  These data reflected emissions and
control strategies implemented by sources in the State through 2005.

In its August 2008 letters responding to State recommendations, EPA
recognized that certain power plants or large sources of emissions in a
potential nonattainment area may have installed emission controls or
otherwise significantly reduced emissions since 2005 and that this
information may not be reflected in the 2005 data.  EPA noted that it
would consider additional information on emission controls in making
final designation decisions.  In cases where specific plants have
installed emission controls since 2005 or plan to install such controls
in the near future, EPA requested additional information on:

the plant name, city, county, and township/tax district

identification of emission units at the plant, fuel use, and megawatt
capacity

identification of emission units on which controls will be installed,
and units on which controls will not be installed

identification of the type of emission control that has been or will be
installed on each unit, the date on which the control device became /
will become operational, and the emission reduction efficiency of the
control device

the estimated pollutant emissions for each unit before and after
implementation of emission controls

whether the requirement to operate the emission control device will be
federally enforceable by December 2008, and the instrument by which
federal enforceability will be ensured (e.g.  through source-specific
State Implementation Plan (SIP) revision, operating permit requirement,
consent decree)

Some commenters claimed that EPA intends to include partial county areas
simply due to the existence of a power plant in the area.  EPA did not
include these areas simply due to the existence of a power plant, but as
a result of a reasoned evaluation of information indicating the likely
contribution by the source to PM2.5 concentrations at the nearby
violating monitor.  This information included emissions data, ambient
air quality speciation monitoring data, meteorological data, information
about current and future planned emission controls, and related
geographic information.

A number of States provided comments to EPA with specific additional
information on power plants, and they requested that EPA remove such
facilities from the list of areas intended for inclusion as
nonattainment.  Some commenters noted that certain facilities have plans
for emission controls to be installed and operational on a date later
than the December 2008 date on which the designations were finalized,
and they have requested that EPA consider whether a facility contributes
to a violation based on projected lower future emissions levels after
future installation of controls.  EPA interprets section 107(d) as
requiring the designation of areas which currently (i.e.  through 2008)
emit pollutants contributing to violations of the 24-hour standard.
Therefore, in making decisions about contributing areas, EPA did not
take into consideration emission controls that would be implemented
after the December 2008 date for the Agency’s final action on
designations.  EPA recognizes that implementation of future emission
controls will provide important improvements in air quality and they
should be included in the State implementation plans for these
designated nonattainment areas.  These emission reductions should be an
important element of the State plan for attaining the PM2.5 standards,

In the event that emission controls have been installed and are
operational at a facility prior to December 2008, or the facility
significantly reduced emissions due to another reason (e.g., the shut
down of certain units at the plant), EPA considered two related issues.
One issue is whether the emission control requirement on the source is
federally-enforceable.  Generally, a requirement is considered to be
federally-enforceable if 1) it has been adopted by the State and
approved by EPA as part of the SIP; 2) it has been approved as part of a
federally-enforceable Title V operating permit or new source
review/prevention of significant deterioration (PSD) permit; or 3) it is
required as part of a consent decree, and the consent decree includes a
provision for the emission reduction requirement to be included in the
SIP or federally-enforceable permit upon fulfillment of the consent
decree.  EPA has determined that only federally-enforceable emission
controls in place prior to December 2008 should be considered in this
process.

A second issue is whether, after the implementation of emission controls
prior to December 2008, the facility continues to emit pollutants at
levels which still contribute to fine particle concentrations at a
nearby violating monitor.  For example, certain large facilities may
continue to emit several thousand tons or more per year of SO2 or NOX
even with operation of emission controls.  To assess contributions from
large sources, EPA considered a number of factors, including emissions
data, meteorological information, and ambient air quality data.  Each
area was considered based on the specific facts for that situation.  EPA
does not believe, however, that the presence of an emission control
device alone should be used as a basis to exclude a source that is
otherwise deemed to be contributing to the violations.  In the
Agency’s final action, a number of partial county areas with large
power plants were included in nonattainment areas based on the
Administrator’s judgment that such areas were contributing to nearby
violations.

SECTION V:  Consideration of Other Regulations

State Comment:  Consideration of CAIR-related emissions reductions

Kentucky:

Although at this point in time it is uncertain what reductions can be
attributed to CAIR or its replacement, it is certain that some manner of
control similar to CAIR will be implemented.  This will further reduce
these emissions since the Selective Catalytic Reduction (SCR) should be
operated year-round instead of only during the ozone season.
Kentucky’s NOX SIP Call regulations remain in effect and, if CAIR
continues to be in limbo, it will cover the 2009 allocation timeframe.
In addition, non-EGUs in Kentucky will also be required to put on Best
Available Retrofit Technology (BART) controls, which will further
achieve PM air quality improvements.  To designate counties
nonattainment because they have a power plant in them would place
additional hardships on the county and would be counterproductive since
the EGUs in the entire region will be mandated by EPA’s CAIR rule to
significantly control their PM precursor emissions without being
designated nonattainment.

EPA Response:

As required by section 107 of the CAA, EPA determined violations of the
2006 24-hour fine particulate NAAQS based solely on the most recent
three complete years of certified monitoring data.  EPA set boundaries
based on available data and analysis that best represents present-day
conditions, and not on projected emissions reductions that may occur
after area designations are finalized.  Section 107 requires EPA to
designate all areas within three years of promulgation of a new NAAQS
and to designate as nonattainment any area that violates or contributes
to an area that violates a NAAQS.  The statute is written in the present
tense and thus EPA believes it can only base designations on controls
that are in place and federally enforceable by the effective date of
final designations.

States may account for other projected emissions reductions in their
State SIPs for achieving attainment, where appropriate.  States will
also be able to take advantage of any air quality benefits that may have
already occurred from recently enacted rules by submitting the 2008
monitoring data to EPA by February 20, 2009.  EPA will review 2008
monitoring data submitted by this date, and will modify designation
areas if appropriate prior to the effective date of the final
designations.  EPA notes that compliance with CAIR (or any other rule
based upon section 110(a)(2)(D) or section 126) does not negate the
obligation of a source to comply with nonattainment area requirements.
If a source is contributes to local nonattainment, it may well need to
be evaluated for additional controls necessary for local attainment
needs, as well as reductions to eliminate interstate transport.

State Comment:  Anticipated reductions in PM2.5 levels due to recent
low-sulfur gasoline and diesel rules

Kentucky:

In many areas, EPA based potential nonattainment designations on the
supposition that population, commuter traffic, or VMT played an
important role in determining potential impacts on PM2.5 levels within
an MSA.  It is not feasible to designate a county as nonattainment if
the only reason an area has been included was due to these
population-based factors.  With national controls being implemented that
would address this contribution, including these counties as
nonattainment would place additional, burdensome planning requirements
on these local areas for no useful purpose.  Due to the Tier 2 Vehicle
and Low Sulfur Gasoline program, which became effective beginning in
2006, average national gasoline sulfur levels dropped 90 percent.  The
new Low Sulfur Diesel Rule, which began to be phased-in beginning in
2007, along with new clean engines operating requirements will reduce
NOX emissions by 50 percent, and reduce PM emissions by more than 90
percent.  The implementation of these new federal rules will
significantly decrease the fine particulate contribution in and from
areas impacted by population and transportation factors.

Michigan:

National rules are reducing emissions from both mobile and non-road
mobile sources throughout the region.  The Michigan Department of
Environmental Quality (MDEQ) believes that decreased emissions in the
area will ensure that the Grand Rapids metropolitan area will attain and
continue to maintain the daily PM2.5 standard.

Ohio:

Beginning in 2004, refineries began phasing in a new sulfur level for
gasoline due to the new federal standard for fuel.  This standard
requires the average sulfur level to be no greater than 30 parts per
million (ppm).  This represents a 10-fold reduction where average
national levels in 2002 were 300 ppm.  Also beginning in 2006, a new
requirement for ultra low sulfur diesel fuel (15 ppm) began phasing in.
As with gasoline, this represents an enormous decrease from the 380 ppm
average measured in 2002.  These sulfur reductions are a key contributor
to large scale vehicular emission reductions in S02, which in turn, will
continue to have a positive impact on reducing PM2.5 emission.

EPA Response:

As explained above, consistent with section 107, EPA determined
violations of the 2006 24-hour fine particulate NAAQS based solely on
the most recent three complete years of certified monitoring data.  EPA
set boundaries based on available data and analysis that best represents
present-day conditions, and not on projected emissions reductions that
may occur after designation areas are finalized.  As noted, EPA does not
believe the statute allows consideration of future controls that have
not produced emissions reductions by the effective date of the
designations.

States may account for other projected emissions reductions in their
SIPs for achieving attainment, where appropriate.  States will also be
able to take advantage of any air quality benefits that may have already
occurred from recently enacted rules by submitting the 2008 monitoring
data to EPA by February 20, 2009.  EPA will review 2008 monitoring data
submitted by this date, and will modify area designations if appropriate
prior to the effective date.

State Comment:  Anticipated reductions in PM2.5 levels due to State or
local rules and control strategies

Iowa:

Iowa is making “substantial progress” on the control strategies for
the sources which are most responsible locally for the violations
(Blackhawk Foundry, Grain Processing, and Muscatine Power and Water),
which will be in place on an “expedited timeline” which is likely to
achieve attainment for both areas by 2014.  In addition, voluntary
measures are ongoing in the Quad Cities which will continue to improve
air quality.

EPA Response:

EPA recognizes the efforts by the state and the stakeholders to achieve
emissions reductions as soon as possible.  EPA also encourages both
states to continue efforts to assist the community in implementing
voluntary measures.  However, under section 307(d) of the Clean Air Act,
in designating nonattainment areas, EPA must designate, as
nonattainment, areas that are violating a NAAQS and areas that are
contributing to the violations.  This requirement does not authorize EPA
to rely on the ongoing efforts to develop future control strategies in
determining nonattainment boundaries.  EPA’s decision must be based on
the statutory requirements, and EPA’s promulgation of the
nonattainment designations for these areas, as described in detail in
the TSDs, meets the statutory requirements.

We also note that the state’s submission includes a “mitigation
plan” provided by Blackhawk Foundry.  The plan states that the
company’s intended control strategy, when fully implemented, “will
significantly reduce PM2.5 concentrations”.  However, the document
also concludes that, after implementation of the “preferred
alternatives” identified in the company’s control strategy, the
“combination of the predicted concentration” from the foundry, and
the background concentration, “could result in a predicted exceedance
of the PM2.5 NAAQS”.  (“PM2.5 Emissions Mitigation Plan”, Oct. 10,
2008, at p. 3.)  This information provides additional justification for
establishing a boundary that ensures emissions from other sources in the
area are considered in developing the attainment demonstration control
strategies for the Muscatine and Davenport areas.

Wisconsin:

Since 2007, the State has promulgated four significant rules.
Collectively, when fully implemented in 2015, these four rules will
reduce SO2 and NOX emissions in the State by 82 percent and 62 percent
respectively below 2005 levels.

EPA Response:

Wisconsin also noted several emission reduction rules that it has
recently promulgated.  Full implementation of the rules should result in
significant emission reductions throughout the State.  The emission
reductions resulting from current programs and future planned reductions
will help improve the air quality in Wisconsin.  EPA commends Wisconsin
for it’s emission reduction efforts.  Still, for the fine particulate
designations, EPA must use the current information for making its
designations.  As explained above, section 107 requires designations to
be based on current conditions.  The uncertainty of future emission
reductions and new or expanded sources would not allow EPA to make an
accurate determination of the nonattainment area if these assumptions
were used.  Thus, EPA considers the emission controls in place for
designations.  Also, with EPA allowing early submission of 2008
monitoring data prior to the effective date of the designations, the air
quality improvement from current emissions reduction programs will be
factored into the final effective designations.  Wisconsin can include
the planned future emission reductions as it develops the area
attainment plans.

Wisconsin has recently enacted several rules to reduce emissions of a
variety of pollutants.  Reductions in fine particulate emissions coupled
with reductions in the precursor emissions, which form fine particulate
in the atmosphere, will lead to improved air quality.  The large
reductions in two key precursors predicted by the State are impressive.
Wisconsin expects a 62 percent reduction in nitrogen oxide and an 82
percent cut in sulfur dioxide emissions from 2005 levels in 2015.  These
are sizeable emission reductions.  Wisconsin can take advantage of the
reductions that have already occurred by submitting early 2008
monitoring data for areas that have made enough improvement to meet the
air quality standards based on 2006 – 2008 data.  The upcoming
emissions reductions will benefit areas with ambient concentrations
remaining above the fine particulate standards by continuing the
improvement toward reaching the air quality standards.

SECTION VI:  Exceptional Events

State Comment:  Exceptional Events

Indiana:

EPA needs to make a documented, reasoned determination concerning
Indiana’s exceptional events submittal for all PM2.5 data used to
determine compliance with the 24-hour PM2.5 NAAQS.  The repeated
conclusion that “Indiana did not fully establish a causal connection
to the event and failed to meet the ‘but-for’ test” does not
contain adequate information to understand EPA’s conclusion and what
specifically would need to be provided to change EPA’s determination.
The fact that EPA concurred with every exceptional event where the
24-hour concentrations were below 35 (g/m3, but rejected every event
where the 24-hour concentration was above 35 (g/m3 appears arbitrary,
especially when the rejected episodes all relate to significant
wildfires that were widely reported in the news at the time as causing
widespread air quality issues (which we indeed saw in our monitoring
data).

EPA Response:

EPA has evaluated Indiana’s submittal in accordance with the criteria
and procedures that it established in its exceptional event rule.  EPA
provided documentation of its “reasoned determination” regarding
claims for the 2004-2006 period with its letter to Indiana dated August
19, 2008, and EPA is providing documentation regarding claims for 2007
in the TSD.  Under the Exceptional Event rule, Indiana has the
obligation to demonstrate that each of several criteria are met, most
notably that there would have been no exceedance or violation “but
for” the exceptional event.  Indiana cannot shift this burden of proof
to EPA.  Nevertheless, in order to evaluate the Indiana Department of
Environmental Management’s (IDEM) exceptional event claims
comprehensively, EPA thoroughly reviewed information submitted by IDEM
as well as other additional information not included in IDEM’s
exceptional event demonstration.  In some cases, the supplemental
information led to concurrence on IDEM’s exceptional event claims, and
in other cases, the totality of the evidence did not support EPA
concurring.  Documentation of EPA’s review, including additional
sources of information, is included in the TSD.

Indiana has noted a pattern in EPA’s concurrences and non-concurrences
with claims for

2004-2006 events, but Indiana is incorrect in inferring that this result
is arbitrary or somehow predetermined.  An examination of patterns of
EPA’s findings regarding Indiana claims for 2007 exceptional events
clearly demonstrates that, for example, EPA neither concurred with every
claim for concentrations above 35 (g/m3 nor rejected every claim below
35 (g/m3.  Instead, EPA examined each claim for each day and each
monitoring site in accordance with the criteria and procedures
established  in the exceptional events rule, and EPA has provided
documentation of its rationale in each case.

News reports of significant wildfires causing air quality issues can be
used as supporting evidence in establishing causal relationship between
the measurement and event claimed to have affected air quality.  News
accounts can also help corroborate quantitative evidence; however, such
reports are rarely determinative of the occurrence of an exceptional
event.  Additionally, for the exceptional event claims from 2004, 2005,
and 2006 for which EPA did not concur, IDEM did not provide any news
reports or stories in the exceptional event demonstration.

SECTION VII:  Other General Issues

State Comment:  States’ authority to impose additional necessary
emissions reduction measures

Alabama:

The Alabama Department of Environmental Management (ADEM) has the legal
authority to impose reduction measures in any area of our State, as
necessary, to attain the NAAQS, regardless of which areas are formerly
designated as nonattainment.  Accordingly, in our December 2007
submittal, the only counties that we recommended be designated
nonattainment were those with monitoring data exceeding the 24-hour
PM2.5 NAAQS.  High background PM2.5 levels present in the entire eastern
United States and emissions generated in the local area around the
violating monitors are the major causes of the elevated PM2.5
concentrations.  Accordingly, air pollution controls necessary to
mitigate regional background levels must be regional or national in
nature.  To repeat, the State-specific reduction measures which will be
needed for attainment are likely to occur only in the area covered by
our proposal for a partial-county area.  In the unlikely event that
further State-specific reduction measures are needed outside the
boundaries of our proposal, ADEM has the necessary authority to impose
them.

EPA Response:

Section 107(d) directs that “…any area that does not meet (or that
contributes to ambient air quality in a nearby area that does not meet)
the national primary or secondary ambient air quality standard for the
pollutant” be designated as nonattainment.  EPA is legally bound to
carry out this directive, and therefore cannot base designation
decisions on a State’s ability or inability to impose targeted
measures either within or outside a nonattainment area that may result
in a violating monitor attaining the standard at some point in the
future.  Nonattainment designations must be based on current air quality
regardless of whether polluting emissions are local, regional or
transported from much further away.  All violating and nearby
contributing areas must be designated nonattainment consistent with the
statute.  States and EPA will then address the sources of pollution in
preparing implementation plans and other measures to address regional
transport.

State Comment:  County-level designations in Western States not
appropriate (CA)

California:

One of the primary issues that must be addressed when discussing the
boundaries of a nonattainment area in California is the large size of
California counties versus other States.  The average area of a
California county is 2,822 square miles, yet the average county size in
the United States is 622 square miles.  Alaska and Arizona are the only
States with larger average county size (Table 1 on page 5 of the
California comment letter).  The average California county is over 4½
times the average U.S. county; many as large, if not larger, than entire
States.  In many cases, California counties contain one or two urbanized
regions and large stretches of sparsely populated areas.

Much of the 9-factor analysis utilized by U.S. EPA to determine PM2.5
nonattainment areas is based at the county level.  This presents some
unusual challenges for California.  For instance, applying county-wide
VMT statistics to a large California county misrepresents differences
that may exist in VMT urban and rural areas in that county, or between
two widely separated urban areas in the same county.  Throughout this
submittal, we offer alternative approaches to analyzing the nine factors
when county size presents a particular problem.  This problem is most
evident in Imperial County where the three main urban areas represent
only one percent of the county (in square miles) recommended as a
nonattainment area.  The remaining 99 percent of the county is sparsely
populated.

EPA Response:

In designating nonattainment areas for the 2006 24-hour fine particulate
matter NAAQS, EPA considered a partial-county boundary for a violating
or contributing county on the basis of:  1) The existence of a power
plant as the major source of emissions in a county, with the county
ranking low for other factors; 2) Topography, where topography is
isolating an airshed within the county; or 3) Factors other than
topography that demonstrate a unique situation in which the sources
captured by the partial-county boundary account for nearly all of the
total fine particle mass on exceedance days; or international emissions
are a significant contributor, and the domestic sources captured by the
partial-county boundary account for nearly all of the domestic
contribution to the total fine particle mass on exceedance days.  Under
this analysis EPA considered the large size of some counties in the west
and did designate partial counties in such areas where the area-specific
data demonstrated that the partial county accounted for nearly all of
the sources contributing to the violating monitor.

While EPA used county-wide statistics, we also scrutinized population,
traffic, and stationary sources of emissions data at a smaller scale,
using spatial analysis and geographic information systems (GIS).  We
used publicly available data sources including the U.S.  Census for
population, the FHWA’s Freight Analysis Framework, and the NEI.  In
all of the areas where EPA’s boundary recommendations were larger than
California’s recommendations, the majority of the county's population,
traffic, and stationary sources were included in the boundary we
recommended.  Furthermore, in many cases we used township and range
boundaries, rather than county boundaries, as a more appropriate means
to define nonattainment area boundaries in Imperial, Butte, Yuba, Yolo,
Placer and El Dorado Counties.

State Comment:  Economic hardship considerations

Michigan:

The 2006-2008 three-year daily average shows only monitors in Wayne
County and St. Clair County in violation of the standard.  The Michigan
Department of Environmental Quality (MDEQ) continues to believe that
designating a huge nonattainment area in response to violating monitors
in a small area is heavy-handed and unnecessary.  It serves to
economically penalize the entire region at a time when the State has
been economically distressed for the past eight years and is struggling
to revive.

Ohio:

The consequences of having a nonattainment designation status will have
a significant economic impact on the townships as well as the entire
counties discussed previously, which are already experiencing severe
fiscal problems, high rates of unemployment, population migration, and
the other social dislocation associated with such economic distress.
Given these circumstances and the absence of data which solidly
demonstrate that such nonattainment designations are appropriate, I
strongly encourage US EPA to reconsider its original findings.

EPA Response:

EPA is required by the CAA to designate all violating and nearby
contributing areas nonattainment without regard to potential economic
impacts.  EPA used the data it had available in conjunction with State
recommendations and public input to analyze on a case-by-case basis
which areas should be included in each nonattainment area.  However, EPA
does not believe that a nonattainment designation necessarily and
significantly limits economic growth.  The requirements for new sources
in nonattainment areas are similar to those in attainment areas.  In
both areas, new sources must be well controlled and must appropriately
address the impact of the new source on air quality.  While companies
will blame environmental restrictions for facility location selections
there are many other factors such as market access, skilled labor
access, and various cost factors that affect the location decision.

SECTION VIII:  Typographical Errors

Alaska:

On page 1 of EPA’s technical analysis for Juneau there is a
typographical error.  The second sentence starts “This technical
analysis for Fairbanks…” and should read “This technical analysis
for Juneau…”

EPA Response:

EPA has corrected this error in its final Technical Support Document.

Connecticut:

We note one inaccuracy on page 3 of EPA’s response to Connecticut’s
recommended designations.  The response refers to the 1997 PM2.5 NAAQS
nonattainment boundary for the New York City metropolitan area as
including Hartford and Fairfield Counties in Connecticut.  Rather, the
New York City metropolitan area included New Haven and Fairfield
Counties in Connecticut.  We hope you will correct the record in this
respect to avoid any confusion in the future.

EPA Response:

EPA has corrected this error in its final Technical Support Document.

Idaho:

Figure 9 on page 19 of the December 2007 submittal has an incorrect
image.  Please substitute the corrected page 19 attached to this
document.

EPA Response:

EPA has corrected this error in its final Technical Support Document.

Kentucky:

The ‘2005 VMT’ data should be labeled ‘millions’ (annual) miles
not 1000’s.  This error occurs throughout the letter in the Traffic
and Commuting Patterns Table.

EPA Response:

EPA has corrected this error throughout its final Technical Support
Document.

AREA-SPECIFIC ISSUES

Allentown, PA

New Jersey:

The “urban increment” in EPA’s technical analysis, which only uses
the “high” days (top 5 percent of days), does not take into account
the direct impact of a major point source such as the Portland
Generating Station, which is situated directly next to Knowlton
Township.  The Portland Generating Station is the single largest source
of both SO2 and carbon emissions in the Knowlton area.

EPA Response:

The “urban increment” identifies the non-regional contribution of
PM2.5 on high days to violating monitors.  For the Allentown, PA area,
the violating monitor is located in Northampton, PA.  The “urban
increment” is incorporated into the CES, which takes into account
emissions data, meteorological data, and air quality monitoring
information to provide a relative ranking of counties that contribute to
a monitored violation of a PM2.5 NAAQS within a nonattainment area.  The
CES metric was not meant to be an exclusive way for consideration of
data for these factors.

The CES method places primary emphasis on characterizing those days when
ambient PM2.5 concentrations at a monitor are near or exceed the
standard.  The CES specifically considers the influence of emissions,
including data from major point sources, and meteorology on days with
high 24-hour fine particle concentrations.  The information is
particularly relevant for a 24-hour standard, for which individual days
affect attainment status, unlike an annual standard, which considers air
quality throughout the year.  The CES examines all days in an area that
are above the 95th percentile or the level of the NAAQS, whichever is
lower.

EPA considers the CES to be a reasonably realistic model of the actual
processes that affect the contribution linkage between a monitored
violation in a violating county and emission sources in a nearby
potentially contributing county.  The CES was not designed to assess the
impact of individual sources on areas not identified as violating
through monitored data.

New Jersey:

Any emissions (primary and secondary) from the Portland Generating
Station would easily put the Knowlton area over the 35 ug/m3 standard
based on an air quality monitor in Phillipsburg, with a design value of
34 ug/m3.

EPA Response:

Current regulations for determining violations of the fine particle
NAAQS require that violations  be determined on the basis of complete,
quality-assured ambient air quality data at a monitor in

the area.  The air monitor in Phillipsburg, Warren County measured 34
ug/m3.  Consequently, this county is not currently violating the PM2.5
NAAQS notwithstanding emissions from the Portland Generating Station.
EPA strongly advises New Jersey to place an air quality monitor in the
vicinity of Knowlton Township, to support the State’s determination
that Warren County (or portions thereof) is violating the 24-hour
standard.  Without such monitoring data EPA cannot designate the area
nonattainment based on a violation, and for reasons explained in the TSD
EPA also does not have data to support designating Warren County
nonattainment based on contribution.

New Jersey:

New Jersey indicated that they disagreed with EPA’s assessment that
the Delaware River does not significantly influence the air shed.  Since
Knowlton Township and the Portland Generating Station are located in the
river valley, limited air mixing emissions from the Portland Generating
Station would directly impact Knowlton Township.

EPA Response:

EPA agrees with New Jersey that there would be limited air mixing within
the Delaware River Valley.   However, without monitoring data to
contradict the existing data for Warren County EPA can not determine
that Warren County is currently violating the PM2.5 NAAQS.  EPA
continues to strongly advise New Jersey to place an air quality monitor
in the vicinity of Knowlton Township, to support the State’s
determination that Warren County (or portions thereof) is violating the
24-hour standard.

New Jersey:

EPA is using the State line between Pennsylvania and New Jersey as the
boundary for the nonattainment area.  The State line does not prevent
SO2 and PM2.5 emissions from the Portland Generating Station from
impacting Knowlton citizens.

EPA Response:

Although emissions from Pennsylvania may impact Knowlton Township in
Warren County, the current air monitor in Warren County is currently not
in violation of the fine particle NAAQS.  As stated previously, current
regulations for determining violations of the fine particle NAAQS
require that violations be determined on the basis of complete,
quality-assured ambient air quality data at a monitor in the area.

New Jersey:

The CAA does not specifically require monitoring data when designating
or redesignating an area.  The regulations cited by EPA, 40 CFR
50.13(c), which references Appendix N, does not specifically provide
that monitoring data is the only data that can be used in support of a
redesignation or designation.  Further, U.S. EPA’s June 8, 2007
designation guidance memo should not limit States from considering other
scientifically valid approaches to understanding air quality in an area.
 New Jersey agrees that quality assured air quality monitoring data
should be used whenever available.  In the case of Knowlton, the use of
air quality modeling data to supplement the region’s air monitors is
appropriate given the geographical complexities of the area.

New Jersey stated that according to Section 171(2) of the CAA, the term
‘nonattainment data’ means for any pollutant area which is shown by
monitored data or which is calculated by air quality modeling (or other
means determined by the Administrator to be reliable) to exceed any
NAAQS.

New Jersey provided technically sound and consistent modeling results
based on two different models which, when used with regional air
monitoring data, indicate violations to the 2006 24-hour PM2.5 NAAQS.

EPA Response:

EPA agrees that section 107(d) does not explicitly state that only
monitoring data can be used for promulgation of designations, and EPA is
considering other information as appropriate to evaluate areas that may
be contributing to violations.  However, EPA regulations relevant to the
NAAQS and monitoring for the NAAQS do describe at length the
requirements (which are based on monitoring) for determining whether a
violation of the PM2.5 NAAQS has occurred.  EPA’s guidance for these
designations likewise explained that for an area to be “violating”
the NAAQS, it must have at least one FRM with data establishing such
violation.  For contributing areas, other information can be relevant.

 percentile 24-hour concentration, as determined in accordance with
appendix N of this part, is less than or equal to 35 μg/m3.

Appendix N to Part 50-Interpretation of the NAAQS for PM2.5 explains the
data handling conventions and computations necessary for determining
when the annual and 24-hour primary and secondary NAAQS for PM2.5
specified in 50.13 are met.  While monitoring requirements necessary for
determining NAAQS compliance are discussed in detail in Appendix N,
requirements for the use of modeling to demonstrate whether the NAAQS
has been exceeded are not specified.  Thus, EPA believes that monitoring
information is necessary in order to substantiate a nonattainment, or
attainment, designation made by EPA.  Therefore, EPA is designating
“violating” areas based upon the presence of an air monitor meeting
regulatory requirements to show that a violation, as defined in the
regulations for the NAAQS, has occurred.

EPA does not believe that its June 8, 2007 designation guidance memo
limits States from considering other scientifically valid approaches to
understanding air quality in an area.  Current Agency regulations
indicate the requirements for designating “violating” areas.
EPA’s designation guidance memo identifies the current regulations
which are applicable for identifying NAAQS violations, specifically
using data from Federal Reference Method (FRM) and Federal Equivalent
Method (FEM) monitors that are sited and operated in accordance with 40
CFR Part 58, and indicates the procedures given in 40 CFR Part 50
Appendix N for using these data to determine whether a violation has
occurred.

EPA agrees that the modeling performed by New Jersey does provide
valuable information for understanding air quality in Warren County.
Based on the air modeling performed by New Jersey which shows the
potential to exceed the PM2.5 NAAQS using New Jersey’s modeling
inputs, EPA strongly recommends that New Jersey place an air quality
monitor in the area of impact to demonstrate a possible violation of the
PM2.5 NAAQS.

New Jersey states that Section 171(2) of the CAA defines the term
‘nonattainment data’ as

“any pollutant area which is shown by monitored data or which is
calculated by air quality modeling (or other means determined by the
Administrator to be reliable) to exceed any NAAQS.”

New Jersey is citing a pre-1990 version of the CAA that has since been
modified.  Section 171(2) of the CAA, which defines nonattainment areas,
no longer refers to air quality modeling.  The provision now refers to
areas “designated ‘nonattainment’ with respect to that pollutant
within the meaning of section 107(d).  This change was accompanied by
revisions to section 107 itself which eliminated provisions for
designations for the SO2 NAAQS that directed EPA to designate areas
based on future projected attainment status, i.e., through a process
that would have necessitated modeling the future ambient level at FRM
monitors.  This provides further evidence that it is not appropriate to
base determinations of violations for purposes of designation on
modeling data alone, especially in the face of valid monitoring data for
the same county showing attainment.

Birmingham, AL

Alabama:

Alabama argued that the existence of

“high background levels present in the entire eastern United States
and emissions generated in the local area around violating monitors are
the major causes of the elevated PM2.5 concentrations.”

As a result, Alabama argued that regional control strategies are
necessary to address the regional background levels and that “local”
emissions sources are being analyzed by the Department for Reasonably
Available Control Technology (RACT) level controls, i.e., nonattainment
area plan requirements.

EPA Response:

EPA disagrees with the State’s argument for several reasons.  First,
it is not disputed that areas in the Eastern U.S., including Birmingham,
are subject to regional transport of pollution.  However, that regional
transport does not comprise the entire amount of ambient PM2.5 measured
at the violating monitors in the Birmingham area.  The purpose of the
designation process is to identify those “nearby” areas that contain
emissions sources or activities that are contributing to the violations.
 It is not appropriate for EPA to exclude nearby areas that are
contributing, merely because there is also transport from more distant
areas.  Moreover, the CAA provides other tools, most notably section
110(a)(2)(D) and section 126, to address interstate transport.

Second, EPA does not agree with Alabama’s view of what constitutes
“local” emissions sources in the context of designations.   As with
regional background, these “local” sources identified by Alabama are
not the exclusive source of ambient PM2.5 levels in the Birmingham area.
 Under section 107(d), EPA must identify both violating and nearby
contributing areas.  Because PM2.5 and PM2.5 precursor emissions can be
transported across great distances, the evaluation must take into
account sources that contribute in an area based upon the facts and
circumstances of that specific area.  In its guidance EPA recommended
various forms of information that are relevant for evaluating
contribution, and the Agency has used a number of relevant analytical
tools in evaluating the Birmingham area, as explained in the TSD for
this area.

Third, the State’s argument with respect to “regional” and
“local” emissions is that contribution is limited to the source or
sources that “cause” the violation at a violating monitor, i.e.,
those sources add the last increment of ambient PM2.5 above the level of
the standard.  EPA does not agree that section 107(d) contemplates that
“contributes” should be read to mean “causes” in the sense meant
by Alabama.  EPA believes that section 107(d) requires a designation of
nonattainment for those areas that “contribute” to the violation,
i.e., that have emissions sources or activities that cumulatively add to
the ambient PM2.5 at the violating monitor.  This reading of the statute
is consistent with the purpose of nonattainment area designations, which
is to provide the boundaries for those areas within which States should
evaluate all sources for controls in the context of the nonattainment
area SIP development, to impose controls as appropriate on such sources,
and to provide for expeditious attainment of the NAAQS.  EPA believes it
is not consistent with the statute to truncate that analysis by
excluding nearby areas with sources that are also contributing to
violations in the area.

Alabama:

In its October letter, Alabama also reiterated its arguments that EPA
should only designate a smaller area nonattainment, premised upon the
argument that “specific reduction measures which will be needed for
attainment are likely to occur only in the area covered by our proposal
for a partial county area.”

EPA Response:

EPA disagrees with this approach to designations.  In essence, Alabama
argues that the State and EPA should predetermine which sources should
be controlled as a basis for the designation.  EPA believes that this is
in direct contravention of section 107(d), which obligates EPA to
designate as “nonattainment” those violating areas and those nearby
areas that are “contributing” to the violations.  The full
evaluation of sources within a nonattainment area, including the
determination of which sources of direct PM2.5 and PM2.5 precursors
should be controlled, to what degree they should be controlled, and when
they should be controlled in order to provide for expeditious attainment
of the NAAQS, will occur during the development of the nonattainment
area SIP for this area.  EPA considers it inappropriate to truncate that
analysis and the requirements of the CAA for nonattainment area SIPs
through the creation of artificially smaller boundaries that exclude
areas that contribute to the violations.

Alabama:

The overwhelming majority of NOX and SO2 emissions in Walker County are
due to a single utility located in the county (Alabama Power Company –
Plant Gorgas).  Additional controls have been installed at this power
plant since 2005.  Flue gas desulfurization (FGD) scrubbers have been
installed on units 8, 9 and 10.  Therefore, over 80 percent of the power
generation capacity at Gorgas is being scrubbed.

The overwhelming majority of NOX and SO2 emissions in Shelby County are
due to a single utility located in the county (Alabama Power Company –
Plant Gaston).  A scrubber will be installed on Gaston Unit 5 in 2010.
Unit 5 is the largest unit at Plant Gaston.

EPA Response: