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Draft Technical Supp ort Document

PENNSYLVANIA Area Designations For the

2010 SO 2 Primary National Ambient Air Quality Standard

Summary

Pursuant to section 107(d) of the Clean Air Act (CAA) , EPA must initially designate areas as

either “unclassifiable

, ” “attainment

, ” or “ n onattainment ” for the 2010 1

- hour sulfur dioxide (SO 2 ) primary national ambient air quality standard (NAAQS). The CAA defines a nonattainment area as one that does not meet the NAAQS or that contributes to poor air quality in a nearby area that does not m eet the NAAQS. Table 1 below identifies the counties or portions of counties in the Commonwealth of Pennsylvania (“Pennsylvania” or “PA” ) that EPA

intends to initially designate nonattainment based on monitored violations

.

Table 1. Nonattainment Area Designation s for Pennsylvania

Area Pennsylvania ’s

Recommended Designation of

Areas/ Counties EPA’s Intended Designation

of Designated

of Areas/Counties

Allegheny , PA Allegheny County N onattainment Nonattainment

Beaver , PA Beaver County N onattainment Nonattainment

Indiana , PA Indiana County Armstrong County (partial)

Plumcreek Township South Bend Township

Elderton B orough Nonattainment

U nclassifiable Nonattainment

Nonattainment

Warren, PA Warren County N onattainment Nonattainment

Background

On June 2, 2010, EPA revised the primary SO 2 NAAQS (75 FR 35520 )

, by establishing a new 1

- hour standard at a level of 75 parts per billion (ppb) which is attained when the 3

- year average of

the 99 th percentile of daily maximum 1

- hour average concentrations at each monitor in an area does not exceed 75 ppb

. EPA has determined that this is the level necessary to provide protection of public health with an adequate margin of safety, especially for chil dren, the elderly and those with asthma. These groups are particularly s usceptible to the health effects associated2

with breathing SO 2

. The Agency is revoking the two prior primary standards of 140 ppb

evaluated over 24

- hours, and 30 ppb evaluated over a n entire year because the se standards will not add additional public health protection given a 1

- hour standard at 75 ppb. Accordingly, EPA is not designating areas in this process on the basis of either of these two prior primary standards. Similarly, th e secondary standard for SO 2 has not been revised, so EPA is not designating areas in this process on the basis of the secondary standard.

EPA ’s SO 2 Designation Approach

Section 107(d) of the CAA requires that no later than one year after promulgation of a new or revised NAAQS, state Governors must submit their recommendations for designations and

boundaries to EPA. This de adline was in June 2011. Section 107(d) also requires EPA to provide a notification to states of no less than 120 days prior to promulgating an initial area designation that is a modification of a state’s recommendation. If a state or tribe did not submi t designation recommendations, EPA will promulgate the designations that it deems appropriate.

If a state or t ribe disagrees with EPA’s intended area designations, they have an opportunity to demonstrate why any proposed modification is inappropriate.

Designations guidance was issued by EPA th rough a March 24, 2011 memorandum from Stephen D. Page, Director, U.S. EPA, Office of Air Quality Planning and Standards, to Air Division Directors, U.S. EPA Regions I

- X. This memorandum i dentifies factors EPA intends to evaluate in determining boundaries for areas designated nonattainment. These 5 factors include: 1) Air quality data; 2) Emissions and emissions

- related data (location of sources and potential

contribution to ambient SO 2 concentrations) ; 3) Meteorology (weather/transport patterns); 4)

Geo graphy/topography (mountain ranges or other air basin boundaries); 5) Jurisdictional boundaries (e.g., counties, air districts, pre

- existing nonattainment areas, reservations, metropolitan planning organization) , among any other criteria deemed to be relev ant to establishing appropriate areas designations and boundaries for the 1

- hour SO 2 NAAQS.

The March 24, 2011

, memo recommended that area boundaries be defaulted to the county boundary

unless additional provided information justif ies a larger or smaller boundary than that of the county. EPA believes it is appropriate to evaluate each potential area on a case

- by

- case basis, and to recognize that area

- specific analyses conducted by states, tribes and/or EPA may support a differ ent
boun dary than that of a default county boundary.

In this TSD , EPA discusses its review and technical analysis of the recommendations submitted by Pennsylvania for designations of the 1

- hour SO 2 standard and any modifications from these

recommendations regardi ng areas for which there are monitored violations of the NAAQS.

Definitions of important terms used in this document:

1) Designated “nonattainment” area

– an area which EPA has determined, based on a state recommendation and/or on the technical analysi s included in this document, has violated the

2010 SO 2 NAAQS, based on the most recent three years of air quality monitoring data, or contributes to a violation in a nearby area.3

2 ) Recommended nonattainment area

– an area a State or Tribe has recommended to EPA be designated as nonattainment.

3 ) Violating monitor

– an ambient air monitor meeting all methods, quality assurance and citing criteria and requirements whose valid design value exceeds 75 ppb, as described in Appendix T of 40 CFR part 50.

4 ) 2010 SO 2 NAAQS

- 75 ppb, national ambient air quality standard for SO 2 promulgated in

2010. Based on the 3

- year average of the 99 th percentile of the annual distribution of daily

maximum 1

- hour average concentrations

5 ) Design Value

– a statisti c that describes the air quality status of a given area relative to the level of the NAAQS.

Nonattainment Designations

Introduction

In Pennsylvania’s designation recommendation letter to EPA, dated June 23, 2011, Michael L. Krancer, Secretary of the P ennsylvania D epartment of E nvironmental P rotection (PADEP)

, recommended that Allegheny , Beaver, Indiana, and Warren Count ies be designated as

nonattainment for the 2010 SO 2 NAAQS based on monitored air quality data from 2008

- 2010. Pennsylvania provided it s 5

- factor analysis for each of these four counties as part of its designation recommendation.

Based on EPA’s technical analysis, EPA intends to initially designate four areas as nonattainment (Table 1 ) based on monitored violations of the 2010 SO 2 NAAQS

. The Allegheny Nonattainm ent Area consists of Allegheny Count y ; t he Beaver Nonattainment Area

consist s of Beaver County ; the Indiana Nonattainment Area consists of Indiana County and a portion of Armstrong County (Plumcreek and South Bend Townships and Elderton Borough) ; and the Warren Nonattainment Area consists of Warren County.

The 5 factors were used to analyze the nonattainment areas for 1

- hour SO 2 designations :

1. Air quality data

. This factor considers the SO 2 air quality monitoring data from EPA’s Air Trends website (see http://www.epa.gov/airtrends/values.html ), including the design

value s (ppb) calculated for each monitor in the area for the most recent 3

- year period. A monitor’s design value indicates whether that monitor violates a specified air quality

standard. The 20 10 SO 2 NAAQS is met at a monitoring site when the identified design

value is valid and less than or equal to 75 ppb as described in Appendix T of 40 CFR part

50

. An ambient air monitor whose valid design value exceeds 75 ppb, as described in Appendix T of 40 CFR part 50 is deemed a violating monitor. A design value is only

va lid if minimum data completeness criteria are met. A n SO 2 design value that meets the NAAQS is generally considered valid if it encompasses 3 years of complete data. A year is complete when all 4 quarters are complete. A quarter is complete when 75% of the days are complete. A day is complete when it has 75% of its hours. Data substitution

tests are described in Appendix T of 40 CFR part 50 . Areas where monitoring data4

indicate a violation of the 1

- hour, 75 ppb primary SO 2 standard will be designated as nonattainment.

2. Emissions and emissions

- related data (location of sources and potential contribution to

ambient SO 2 concentrations). We reviewed data from the 2008 National Emissions Inventory (NEI), version 2 (NEI08V 2 ), which was the most current version of the national inventory available in 20 11 when these data were compiled for the designations

process
, (s ee http://www.epa.gov/ttn/chief/net/2008inventory.html .) or other relevant sources of data, such as state inventories or inventories from other federal sources. EPA recognize s that there might be no new information on any changes in emissions that may

have occurred after 2008, but would consider more recent years if available

. For example, certain large sources of emissions in or near an area may have installed emission controls or otherwise significantly reduced emissions since 2008

. Also any additional information we receive on federally

- enforceable emissions control that are not reflected in recent inventories but which will require compliance before final designations are issued were considered. Two source categories from the 2008 NEI were examined: the point source inventory and the nonpoint source inventory. Generally, the point source inventory represents the bulk of the SO 2 emissions in the EPA Region III

states

.

Additionally, a source screening analysis, involving an emissions by distance (Q/d) methodology, was used to assess the need to examine point sources for fur ther review

which are located within 50 kilometers of a violating monitor. North Carolina’s Prevention of Significant Deterioration (PSD) Guidance document ( http://www.ncair.org/permits/mets /psd_guidance.pdf ) describes a screening methodology used to identify point sources to be specifically include d in a modeled impact analysis. According to this method, a source is considered to be significant and, therefore, included in the modeling analy sis if its annual emissions are greater than or equal to twenty (20) times the distance between the source and the point of interest (Q/d≥20 or Q/20d≥1), or as used in this case, the violating monitor. While not used for the same purpose, this methodology was used to identify point sources near a violating

monitor for further review.

Point source emissions data are needed to perform th e Q/d analysis. Three sources of

emissions data were considered for this screening analysis: emissions recorded in the 2008 NEI, the 2010 Clean Air Markets Division (CAMD) reported emissions, and the sources’ permitted emission limits. CAMD emissions were limited to sources with continuous emissions monitors (CEMs). Po int source emission information from the 2008 NEI and 2010 CAMD represent actual yearly emission totals, and these values are probably less than a point source’s allowable or permitted emission limit. Permitted emission limits are generally unavailable si nce most state s lack a central repository or permit database at this time. Emissions used in the Q/d screening analysis were chosen following the steps outlined below in Figure 1

.5 Figure 1

. Emission Decision Tree

3. Meteorology (weather/transport patt erns). We evaluated meteorological data to help determine how weather conditions, including wind speed and direction, affect the plume of sources contributing to ambient SO 2 concentrations. The National Weather Service maintains surface and upper air mo nitoring sites across the United States. Automated Surface Observing System (ASOS) ( http://www.weather.gov/asos ) sites collect hourly averaged wind measurements including wind direction and wind speed. Upper air measurements (rawinsonde) are collected at a limited number of sites where vertical wind profiles are taken using weather balloons. Measurements taken at ASOS and rawinsonde sites are often used in dispersion modeling analyses using EPA’s AERMOD modeling

system.

One

- minute meteorological wind fields for an area’s nearby airport(s) were downloaded and run through AERMOD’s preprocessor AERMINUTE to produce hourly averaged wind fields. This data was then run through Lakes Environmental’s WRPLOT software

t o produce wind roses for the airports, showing predominant wind patterns in the area

.

4. Geography/topography (mountain ranges or other air basin boundaries)

. We examined the physical features of the land that might affect the distribution of SO 2 over an area. Mountains or other physical features may affect the distribution of emissions, and may help define boundaries. Maps depicting elevations and point sources were constructed and evaluated to determine the effects of the topography on point so urce emissions.

5. Jurisdictional boundaries (e.g., counties, air districts, pre

- existing nonattainment areas, reservations, metropolitan planning organizations ) . Once the geographic area associated with the area violating the SO 2 standard and the nearby a rea contributing to violations were determined, we considered existing jurisdictional boundaries for the purposes of providing a clearly defined legal boundary for carrying out the air quality planning and

enforcement functions for the nonattainment area. If an existing jurisdictional boundary is used to help define the nonattainment area, it encompasses all of the area that has been identified as meeting the nonattainment definition. These existing boundaries may Point

- Source Screening Analysis

If Source Emissions (Q) ≥ 20 x Distance from Nonattainment Monitor, Source Received Further

Review If Source Emissions (Q) ≤ 20 x Distance from Nonattainment Monitor, Source Not Considered

Further Point

- Source Emission Selection Process

First Preference: Permitted Next: If no recent controls, max
of NEI or CAMD or Next: If recent controls installed, CAMD Available Point

- Source Emissions

2008 NEI v2

(Actual) 2011 CAMD

(Actual) Permitted

(Allowable)6

include an existing nonattainment or main tenance area boundary, a county or township boundary, a metropolitan area boundary, an air management district, or an urban planning boundary established for coordinating business development or transportation activities. Where existing jurisdictional bou ndaries are not adequate to describe the nonattainment area, other clearly defined and permanent landmarks or geographic coordinates are used.

Pennsylvania recommended the county boundary for all its nonattainment area boundaries, which was the default bo undary as per EPA’s March 24, 2011 designations guidance. In addition to considering the county boundary, we also examined use of Metropolitan Statistical Areas (MSAs) as the jurisdictional boundary. The U.S. Office of Management and Budget (OMB) defines metropolitan and micropolitan stati stical areas according to published standards that are applied to Census Bureau data. The general concept of a metropolitan or micropolitan statistical area is that of a core area containing a substantial population nucleus, together with adjacent communi ties having a high degree of economic and social integration with that core ( http://www.census.gov/population/www/metroareas/aboutmetro.html ). Finally, previously established Ai r Quality Control Regions (AQCRs) were considered as well. The five factor descriptions above are a combination of descriptions from the March 24, 2011 memo and other relevant information pertaining to this TSD.

Technical Analysis for the Allegheny Non attainment Area

This technical analysis for the intended Allegheny Nonattainment Area identifies the whole county with a monitor that violate s the 2010 SO 2 NAAQS

, and evaluates nearby counties for

contributions to SO 2 concentrations in the area. EPA has evaluated this county and nearby

counties based on the weight of evidence of the factors recommended in the March 24, 2011 guidance issued by EPA

.

Based on EPA's technical analysis described below, EPA agrees with Pennsylvania’ s recommendation and initially intends to designate

, based on the violating monitor , Allegheny County in Pennsylvania as nonattainment for the 2 010 SO 2 NAAQS as part of the Allegheny

N onattainment A rea

.

Air Q uality D ata

This factor considers the SO 2 design values (in ppb ) for air quality monitors in Allegheny County in the Allegheny Area based on certified data for the 200 9

- 20 1 1 period

. Figure 2 depicts

the area analyzed and the location of the violating air quality monitor (Liberty m onitor)

.7 Figure 2

.

The 2010 1

- hour SO 2 design values for the five monitors located in Allegheny County are shown

in Table 2

.

Table 2

. Allegheny County Monitor Trends : 1

- Hour SO 2 99 th % and Design Values

in Parts Per Billion ( ppb ) *

Monitor

Name Monitor

Air Quality System ID 99 th % Design

Value Design

Value

2007 2008 2009 2010 2011 2008

- 10 2009

- 11

Avalon 42

- 003

-

0002 70 75 61 53 40 63 51

Carnegie 42

- 003

-

0010 75 62 61 35 23 53 40

Liberty 42

- 003

-

0064 192 111 131 141 165 128 146

South Fayette 42

- 003

-

0067 74 52 53 63 28 48 40

* Monitor in bold has the highest 200 9

- 201 1 design value in the respective county.8

Allegheny County shows a violation of the 2010 1

- hour SO 2 NAAQS (Liberty m onitor)

. Therefore

, this county and nearby counties will be reviewed to determine what area should be designated as nonattainment. T he absence of a violating monitor alone is not a sufficient reason to eliminate nearby counties as candidates for nonattainment status. E ach area has been

evaluated based on the five factors and other relevant information.

Emissions and Emissions

- Related Data

Evidence of SO 2 emissions sources in the vicinity of a violating monitor is an important factor for determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluated county level emission s data for SO 2 and any change in SO 2 emitting activities since the date represented by those emissions data

.

Emissions

EPA recognize s that there might be no new information on any changes in emissions that may

have occurred after 2008, but would consider more recent years if available

. Pennsylvania did not provide updated emissions information, therefor e EPA relied on the 2008 NEI emissions data (NEI08V 2 )

.

Table 3 shows total emissions of SO 2 in tons per year (tpy ) for violating and potentially contributing counties in and around the Allegheny Area and sources emitting or contributing greater than 100 t py of SO 2 according to the NEI08V 2

.

Table 3

. SO 2 Emissions in Allegheny Area (source: NEI08V 2 )

County Facility

Located in

State

Recommended

Nonattainment

Area? Facility Total Facility

SO 2 Emissions (tpy) Total

County

SO 2 Point

Emissions (tpy) Name EIS Coordinates

Allegheny Yes Us Steel Corporation

- Irvin Plant 7409411 40.33554,

- 79.90168 475 35,844

Allegheny Yes Shenango Inc 7407611 40.492,

- 80.07968 333 35,844

Allegheny Yes Orion Power

Midwest

Cheswick

Station 8404811 40.53639,

- 79.79222 30,300 35,844

Allegheny Yes Uss Corporation

- Edgar Thomson

Works 7409311 40.39553,

- 79.86299 1,536 35,844

Allegheny Yes Uss

- Clairton

Works 8204511 40.3055,

- 79.877021 1,517 35,8449

Allegheny Yes Bellefield

Boiler Plant 8404711 40.442127,

- 79.94913 795 35,844

Allegheny Yes Bay Valley Foods, LLC 8521211 40.45343,

- 79.98584 487 35,844

Washington No Orion

Power/Elrama

Power Station 3895011 40.25,

- 79.9167 2,572 3,746

Washington No Allegheny Energy/Mitchel l

Power Station 3894811 40.2228,

- 79.9694 934 3,746

Westmoreland No Arcelormittal

Monesson

LLC/Monesson

Coke Plant 8330811 40.161547,

- 79.883469 396 569

Washington No Langeloth Metallurgical 4778911 40.36346,

- 80.401 186 3,746

Q/d Screening Analysis

Using point source emissions data, the emissions by distance (Q/d) screening methodology was used to identify sources within 50 kilometers (km) of the Liberty monitor that should receive a

further review

. A total of 11 poi nt sources emitting more than 100 tpy (from the 2008 NEI v 2 ) are located within 50 km of the Liberty monitor. Of the 11 point sources, seven are in Allegheny County, three are in neighboring Washington County and one is in Westmoreland County. No permit information was available for our analysis and only one source, Cheswick Power Station, had control equipment installed recently (so the CAMD emissions were used for this source). Following the Q/d methodology, we determined that nine of the eleven source s should receive

further review. These sources are Orion Power Cheswick Station, Bay Valley Foods, Bellefield Boiler Plant, USS corporation

- Edgar Thomson Works, US Steel Corporation, USS Clairton Works, Orion Power Elrama Power Station, Allegheny Energy Mitchell Power Station, and

Arcelormittal Monessen Coke Plant ( Figure s 3

- 4 ).10 Figure 3.

Figure 4

.11

Emissions Controls

Under this factor, the existing level of control of emission sources is taken into consideration. The emissions data used by EPA in this technical analysis represent s emiss ion levels while

account ing for any control strategies implemente d on stationary sources in the Allegheny Area up to and including 2008

. Although EPA has not received any additional information on emissions reductions resulting from controls put into place after 2008

, EPA has collected

additional information

. Cheswick Power Station, had control equipment installed recently

. Elrama Power Station in Washington County has had wet scrub bers installed since the mid 1970’s and was scheduled to shut down in June 2012. Mitchell Power Station in Washington County had wet scrubbers installed in 2006 and 2007.

Meteorology (weather/transport patterns)

Evidence of source

- receptor relationships between specific emissions sources and high SO 2 values at violating monitors is another important factor in determining the appropriate contributing areas and the appropriate extent of the nonattainment area boundary. For this factor,

EPA co nsidered data from sites that collected hourly averaged wind measurements including wind direction and speed for 5 years. There are two meteorological monitoring sites currently operating in Allegheny County. An ASOS and rawinsonde site is located at the Pittsburgh International Airport in the western part of the county. Another ASOS site is located at the Allegheny County Airport in the southern portion of the county. The Allegheny County Airport site is closer to the Liberty monitor. Recent wind data from both airports was downloaded and run through AERMOD’s preprocessor AERMINUTE to produce hourly averaged wind fields.

Th ese data w ere in turn run through Lakes Environmental’s WRPLOT software to produce wind

roses for both of the surface ASOS sites i n Allegheny County and shown below in Figure 5

.12 Figure 5.

Wind rose plots for Pittsburgh International and Allegheny County airports show differing wind distribution patterns. As shown in the map in Figure 5

, th e prevailing wind directions at the Allegheny County Airport are predominantly out of the south and west. At the Pittsburgh International Airport, the prevailing winds are predominantly out of the west / sout h west

. These different wind patterns suggest source emission dist ributions may be dependent on their locations within the county. Differing wind patterns between the two ASOS sites are probably due to the county’s complex topography (see explanation under Geography/topography ).

Pennsylvania provided its own analysis o f meteorological data

. They used wind measurements collected at the Allegheny County Airport from January 2008 to December 2010 and developed a wind rose diagram showing that the wind is primarily out of the west and south at the Allegheny County Airport, with secondary peaks out of the north. During the periods when there are high SO 2 concentrations at the Liberty monitor, the wind is primarily out of the south. In addition, wind speeds are generally stronger, indicating that the winds are unimpeded (fr om any terrain) from that direction. P ennsylvania notes that the Allegheny County Airport meteorological tower is measuring winds at 55 meters above the Libert y monitor. Therefore, the stronger winds at the Allegheny County Airport could potentially sign ify the long range transport of pollutants affecting the Liberty monitor.13

Geography/topography (mountain ranges or other air basin boundaries)

Allegheny County is made up of the high elevations of the Appalachian Mountains with

dendridic valleys carved out by the Ohio, Allegheny and Monongahela rivers systems. Higher terrain lies to the southeast (Laurel Ridge). Elevation differences between the river valleys and the ridge tops can exceed 150 meters. See Figure 6 below.

Most of the la rge (>100 tpy) point sources in Allegheny County reside within the river valleys. This is important since these valleys can create complex wind patterns which will impact sources with low stacks that cannot overcome neighboring elevated terrain causing th e emissions to be trapped within the valleys. T he ASOS meteorological sites in Allegheny County are both located in the higher elevations of the county. This presents a problem in that the meteorological measurements may not be representative of the vall ey flows that can occur under certain atmospheric conditions. These atmospheric conditions may define the times of peak

concentrat i ons for some emissions sources (low stacks for example). Therefore, the large sources residing within the river valleys are likely to cause localized air quality problems.

Figure 6

.

Jurisdictional boundaries

There is an existing maintenance boundary (i

. e.
, previous nonattainment area) for the 1971 primary SO 2 NAAQS in Allegheny County

, in Hazelwood, PA that encompasses the area within14

a 2

- mile radius of the Hazelwood monitor. This boundary is not an appropriate boundary

because i t is too small and does not encompass any of the sources impacting the current violating

monitor (Liberty monitor)

.

T here are other possible boundaries that can be considered: the Pittsburgh, PA MSA and the Southwest Pennsylvania Air Quality Control Region ( AQCR ) . The Pittsburgh, PA MSA contains seven counties: Allegheny, Armstrong, Beaver, Butler, Fayette, Washington , and

Westmoreland. The Southwest Pennsylvania AQCR consists of Allegheny, Beaver, Butler, Armstrong, Indiana, Westmoreland, Fayette, Greene, and Washington Counties.

Drawing the nonattainment boundary based on the Pittsburgh, PA MSA would add significan t areas to the proposed 1

- hour SO 2 nonattainment area ( Figures 7

- 8 ). Portions of the Pittsburg h

, PA MSA would extend beyond 50 km from the Liberty monitor. Using the Pittsburgh, PA MSA as the nonattainment boundary would include sources and areas that EP A is not prepared to

conclude are likely to have an impact at the Liberty monitor.

Figure 7

.

The Southwest Pennsylvania (SW PA) AQCR

, codified in the Code of Federal Regulations (CFR) § 81.23

, is another possible nonattainment boundary. The SW PA AQCR is similar in size to the Pittsburgh, PA MSA but also includes Indiana and Greene counties ( Figure 8 ). The SW PA AQCR does include all counties that lie within 50 km of the Liberty monitor

, but similar15

to the Pittsburgh, PA MSA

, it includes a signif icant area outside this buffer that EPA is not prepared to conclude is likely to contain sources contributing to the violating monitor at Liberty.

Figure 8.

Conclusion for the Allegheny Nonattainment Area

After considering the factors described above, EPA intends to find that it is appropriate to

include Allegheny C ount y as part of the Allegheny Nonattainment A rea for the 2010 SO 2 NAAQS

.

The Liberty monitor in Allegheny County, based on certified 200 9

- 20 1 1 air quality data, shows high concentration of SO 2 emissions in the vicinity. Although m eteorological data suggests that

emissions from large sources south and west could potentially contribute to SO 2 NAAQS

violations in Allegheny County

, based on available information, EPA is not prepared to conclude

that emissions from these sources are contributing to the violating monitor in Allegheny County. Elrama Power Station in Washington County has had wet scrubbers installed since the mid

1970’s and was scheduled to shut down in June 2012. Mitchell Power Station in Washington County had wet scrubbers installed in 2006 and 2007. The emissions from Monesson Coke Plant in Westmoreland County are relatively low

, and it is likely that any impacts fr om these emissions are localized. Furthermore, the emissions from source s nearest the Liberty monitor in Allegheny County are likely causing the violation at the Liberty monitor. Based on the consideration of all the relevant and available information, as described above, EPA believes that the boundar y16

described herein encompass es the appropri ate initial nonattainment area based on the violating

monitor for the 2010 SO 2 NAAQS

.

Figure 9.

Technical Analysis for the Beaver Nonattainment Area

This technical analysis for the Beaver Nonattainment A rea identifies the whole county with a

monitor that violates the 2010 SO 2 NAAQS, and evaluates nearby counties for contributions to

SO 2 concentrations in the area. Beaver County has two violating monitors. EPA has evaluated

this count y and all nearby counties based on the weight of evidence of the factors recommended in the March 24, 2011 guidance issued by EPA.

Based on EPA's technical analysis described below, EPA agrees with Pennsylvania’s

recommenda tion and intends to initially designate

, based on monitored violations, Beaver County in Pennsylvania as nonattainment for the 2 010 SO 2 NAAQS as part of the Beaver

N onattainment A rea

.

Air Quality Data

This factor considers the SO 2 air quality monitoring data, including design values (in ppb)

calculated for all air quality monitors in Beaver County in the Beaver Area based on certified17

data for the 200 9

- 20 1 1 period

. Figure 10 depicts the area analyzed and the location of the

violati ng air quality monitor s.

Figure 10

.

The 2010 1

- hour SO 2 design value for the monitor located in Beaver County is shown in Table 4

.

Table 4

. Beaver County Monitor Trend s: 1

- Hour SO 2 99 th % and Design Value in Parts Per Billion (ppb)

Monitor Name Monitor

Air Quality System ID 99 th % Design

Value Design

Value

2007 2008 2009 2010 2011 2008

- 10 2009

- 11

Hookstown 42

- 007

-

0002 153 122 109 72 58 101 80

Brighton Township 42

- 007

-

0005 170 165 176 161 136 167 158

One

- hour SO 2 design values at the Hookstown monitor appear to be generally falling over the last four years though the data are in sufficient to clearly establish a definitive trend. Values at the Brighton Township monitor appear to be relatively unchanged. The Hookst own monitor’s

99 th % concentrations have fallen by about a factor of two over the last four years while the Brighton Township monitor has remained relatively stable. Monitors within the 50 kilometer18

zone of the violating monitors in the neighboring countie s in PA (Lawrence, Alleg h eny and Washington) are not recording violations

.

Emissions and Emissions

- Related Data

Evidence of SO 2 emissions sources in the vicinity of a violating monitor is an important factor for determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluated county

- level emission s data for SO 2 and any change in SO 2 emitt ing activities since the date represented by those emissions data

.

Emissions

EPA recognize s that there might be no new information on any changes in emissions that may

have occurred after 2008, but would consider more recent years if available

. Pennsyl vania did not provide updated emissions information, therefore EPA relied on the 2008 NEI emissions data (NEI08V 2 )

.

Table 5 shows total emissions of SO 2 in tons per year (tpy) for violating and potentially contributing counties in and around the Beaver Area and sources emitting greater than 100 tpy of

SO 2 according to the 2008 NEI.

Table 5

. SO 2 Emissions in the Beaver Nonattainment Area

County Facility

Located in

State

Recommended

Nonattainment

Area? Facility Total Facility SO 2 Emissions (tpy) Total

County SO 2 Point

Emissions (tpy) Name EIS Coordinates

Beaver , PA Yes First Energy/Bruce

Mansfield Plant 3853711 40.6344,

- 80.42 11,019 17,584

Beaver , PA Yes Horsehead Corp./Monaca

Smelter 7991511 40.67058,

- 80.3365 3,320 17,584

Beaver , PA Yes AES Beaver Valley 8141311 40.6558,

- 80.3556 3,113 17,584

Jefferson,

OH Yes W.H. Sammis

Plant 8190811 40.5308,

- 80.6311 102,195 136,297

Jefferson,

OH Yes Cardinal Power

Plant 8115711 40.2522,

- 80.6486 33,317 136,297

Jefferson,

OH Yes Severstal Wheeling, Inc. 8190711 40.31974,

- 80.6042 700 136,297

Westmore

land , PA No Arcelormittal

Monesson

LLC/Monesson

Coke Plant 8330811 40.161547,

- 79.883469 396 569

Brooke

, WV Yes Mountain State Carbon, LLC 4864311 40.34361,

- 80.60667 731 76719

Hancock

, WV Yes Arcelormittal

Weirton Inc. 6153111 40.42194,

- 80.60278 597 613

Lawrence,

PA No Orion Power

Midwest/New

Castle Power

Plant 3776611 40.9378,

- 80.3681 12,923 14,532

Lawrence,

PA No ESSROC/

Bessemer 6595011 40.9745,

- 80.49011 910 14,532

Lawrence,

PA No CEMEX/ Wampum Cement

Plant 6621611 40.87825,

- 80.3247 674 14,532

Allegheny

, PA Yes Shenango Inc 7407611 40.492,

- 80.07968 333 35,844

Allegheny

, PA Yes Bellefield Boiler

Plant 8404711 40.442127,

- 79.94913 795 35,844

Allegheny

, PA Yes Bay Valley Foods, LLC 8521211 40.45343,

- 79.98584 487 35,844

Q /d Screening Analysis

Using point source emissions data, the emissions by distance (Q/d) screening methodology was used to identify sources within 50 kilometers (km) of a violating monitor in Beaver County

. A

total of 15 point sources emitting more than 100 tpy (from the 2008 NEI v 2 ) are located within 50 km of the Beaver County monitor s . Of these 15 point sources, there are three sources each

located in Beaver County, PA, Allegheny County, PA, Lawrence County, PA, and Jefferson County, OH. There is one source each located in Brooke County, West Virginia, one source in

Hancock Count y, West Virginia and one source in Washington County, PA

. Following the Q/d methodology, we determined that eleven of the fifteen sources should be considered for

additional review. These sources are ESSROC /B essemer, Orion Power New Castle Power Plant,

CEMEX / Wampum Cement Plant, Horsehead

- Monaca Smelter, AES Beaver Valley, First Energy Bruce Mansfield Plant, W.H. Sammis Plant, Arcelormittal Weirton Inc., Mountain State Carbon,

Severs tal Wheeling, Inc., and Cardinal Power Plant ( Figures 11

- 12 )

.20 Figure 1 1

.

Figure 1 2

.21

CAMD Emissions Analysis

Emissions from sources included in EPA’s CAMD database ( http://camddataandmaps.epa.gov/gdm/index.cfm?fuseaction=emissions.wizard ) were reviewed

to determine if more recent emissions are available for sources near the Beaver County monitors.

Not all emissions sources within 50 km of the Beaver County monitor s are included in the

CAMD database ; o nly five of the 15 sources within 50 km of the Beaver County monitor s reported their SO 2 emissions to the CAMD database. These sourc es and their reported annual

emissions are listed in Table 6 along with their distance from the nearest monitor in Beaver County.

Table 6

. CAMD 2008

- 1 1 Emissions Summary of SO 2 Emissions in tpy

Facility County Distance* CAMD

2008 CAMD

2009 CAMD

2010 CAMD

2011 AES Beaver Valley Beaver 3.2 Not

Available 3,500 1,491 3,086

First Energy/Bruce

Mansfield Beaver 7.6 11,117 17,704 8,971 21,196

W

. H

. Sammis Plant Jefferson 11.3 102,619 73,614 12,761 4,202

Orion Power/New Castle

Power Pl an t Lawrence 28.1 12,923 7,629 5,442 7,510

Cardinal Power Plant Jefferson 36.6 32,497 34,751 32,522 25,116 *Distance from Beaver County SO 2 monitor in kilometers.

Emissions Controls

Under this factor, the existing level of control of emission sources is taken into consideration. The emissions data used by EPA in this technical analysis represent s emiss ions levels while accounting for any control strategies implemente d on stationary sources in the Beaver Area up to and including 2008

. Although EPA has not received any additional information on emissions reductions resulting from controls put into place after 2008

, EPA has evaluated additional

information from the 2008 NEI and CAMD.

SO 2 emissions at four of the five CAMD sources have operating SO 2 controls on at least some of their units. The Bruce Mansfield and AES Beaver Valley plants had wet scrubbers installed prior to 2008. The Cardinal and W. H. Sammis power plants in Jefferson County, OH recently

installed wet scrubbers on their units. SO 2 emissions at the W. H. Sammis plant have fallen significantly since the installation and Cardinal’s emissions have decreased as well . Declining

emissions at the W. H. Sammis and Cardinal plant s may be responsible for the declining SO 2 concentrations obs erved at the Hookstown monitor near the PA

- WV border.

Meteorology (weather/transport patterns)

Evidence of source

- receptor relationships between specific emissions sources and high SO 2 values at violating monitors is another important factor in determini ng the appropriate22

contributing areas and the appropriate extent of the nonattainment area boundary. For this factor,

EPA considered data from sites that collected hourly averaged wind measurements including wind direction and speed for 5 years. There ar e two ASOS sites located within 50 km of the Beaver County monitors. The closest surface site is at the Pittsburgh International Airport located approximately 22

- 23 kilometers from either of the Beaver County monitors. The next

closest ASOS site is the W heeling/Ohio County Airport located approximately 44 and 61 kilometers from the Beaver County monitoring sites. The closest rawinsonde site is located at the Pittsburgh International Airport located in western Allegheny County approximately 22

- 23

km from the monitoring sites

.

One

- minute meteorological wind fields for the Wood County Airport site was downloaded and run through AERMOD’s preprocessor AERMINUTE to produce hourly averaged wind fields. This data was then run through Lakes Environmental’s WRPLO T software to produce wind roses for both sites ( Figure 1 3 ). Predominant winds at the Pittsburgh International Airport were generally from the west over the 2006

- 10 time period, while winds at the Wheeling Ohio County Airport were generally from the south west. Given this information, EPA is not prepared to

conclude that large sources in Lawrence County (ie. ESSROC/Bessemer, Orion Power New Castle Power Plant, and CEMEX/Wampum Cement Plant ) are likely to contribute to the violating monitor s in Beaver Count y.

Figure 1 3

.23

Geography/topography (mountain ranges or other air basin boundaries)

Figure 14 below depicts elevations and locations of point sources near Beaver County. The Ohio and Beaver rivers divide Beaver County into roughly three portions. The Ohio River traverses across the county in a roughly east

- west direction while the Beaver River f lows south into the Ohio River near the Borough of Beaver. The river valleys within Beaver County create sharp contrasts with the surrounding mountains in western Pennsylvania. Elevations in the valleys are

in the 220

- 230 meter range. Higher terrain in the county rises to over 350 meters above mean sea level. Terrain can change quite abruptly between the rivers and the mountains. In neighboring Allegheny County complex valley flows have been noted. These types of flow regimes probably exist in the riv er valleys of Beaver County also. This is important because the vast majority of large point sources reside in the river valleys.

Figure 14

.

Jurisdictional boundaries

There is no existing nonattainment/maintenance boundary for the 1971 primary SO 2 NAAQS for

the Beaver Area, however, there are other possible boundaries that can be considered: the Pittsburgh, PA MSA and the Southwest Pennsylvania Intrastate AQCR

. The Pittsburgh, PA MSA is comprised of seven counties: Allegheny, Armstrong, Beaver, Butler, Fayette, Washington, and Westmoreland. The Southwest Pennsylvania Intrastate AQCR consists of nine counties: Allegheny, Armstrong, Beaver, Butler, Fayette, Greene, Indiana, Washington, and

Westmoreland counties.24

The Pittsburgh, PA MSA extends be yond the 50 kilometer buffer from the Beaver County

monitors to the east and includes sources outside of the 50 kilometer buffer (Figu re 1 5 ). Drawing the nonattainment boundary based on the Pittsburgh, PA MSA would add additional

areas to Pennsylvania ’s d esignation recommendation for the 1

- hour SO 2 nonattainment area and

would include sources that EPA is not prepared to conclude are likely to impact the Beaver County monitors.

Figure 15

.

The South Pennsylvania Intrastate AQCR

, codified in the Co de of Federal Regulations (CFR) §

81. 23, is another possible nonattainment boundary. The area is slightly larger than the Pittsburgh, PA MSA and includes nine counties ( Figure 16 ). The South Pennsylvania Int ra state AQCR does not include all of the counties that lie within 50 km of the Beaver County monitors

and includes areas with sources which EPA is not prepared to conclude are contribut ing to the violating monitor. For these reasons it would not be practical to u se this air quality control region as the initial nonattainment boundary based on the violating monitor

.25 Figure 16

.

Conclusion for the Beaver Nonattainment Area

After considering the factors described above, EPA intends to find that it is appropriate to

include Beaver County in the Beaver N onattainment A rea for the 2010 SO 2 NAAQS

. The air quality monitor s in Beaver County show a violation of the 2010 SO 2 NAAQS, based on certified

200 9

- 201 1 air quality data. Meteorological data suggests that emissions from large sources west
and southwest of the monitor likely impact the monitor and contribute to SO 2 NAAQS violations

in Beaver County. Based on the consideration of all the relevant and available information, as described above, EPA believes that the initial boundaries described herein encompass the area

that should be initially designated as nonattainment due to cau s ing or contribu ting to the

monitored violation of the 2010 SO 2 NAAQS in the county. It should be noted that while EPA is not prepared to conclude that some sour c es locate d outside the county have some amount of impact in Beaver County

, those sources are already included in proposed nonattainment areas (see WV recommendations) and are likely havi n g a larger impact in t heir own county. Therefore, EPA is not prepared to conclude that neighboring areas contribute to the SO 2 concentrations in Beaver County.26

Figure 17.

Technical Analysis for the Indiana Nonattainment Area

This technical analysis for the Indiana Nonattainment A rea identifies the whole county with a

monitor that violates the 2010 SO 2 NAAQS, and evaluates nearby counties for contributions to

SO 2 concentrations in the area. For this area, Indiana County has a violating monitor. EPA has

evaluated this count y and all other surrounding counties based on the factors recommended in the March 24, 2011 guidance issued by EPA.

Based on EPA's technical analysis described below, EPA intends to expand upon Pennsylvania’s

recommendation a nd intends to designate , based on the violating monitor, Indiana County in Pennsylvania along with Plumcreek and South Bend T ownships , and Elderton Borough in Armstrong County

, as nonattainment for the 2 010 SO 2 NAAQS as part of the Indiana

N onattainment A r ea

.

Air Quality Data

This factor considers the SO 2 air quality monitoring data, including design values (in ppb)

calculated for all air quality monitors within 50 kilometers of the Indiana County monitor based

on data for the 200 9

- 20 1 1 period

. Figure 18 depicts the area analyzed and the location of the violating air quality monitor

.27 Figure 1 8

.

The 2010 1

- hour SO 2 design value for the monitor located in Indiana County is shown in Table

7

.

Table 7

. Indiana County Monitor Trend : 1

- Hour SO 2 99 th % and Design Value in Parts Per Billion (ppb)

Monitor

Name Monitor

Air Quality System ID 99 th % Design

Value Design

Value

2007 2008 2009 2010 2011 2008

- 10 2009

- 11

Strongstown 42

- 063

-

0004 88 92 82 95 68 90 82

Emissions and Emissions

- Related Data

Evidence of SO 2 emissions sources in the vicinity of a violating monitor is an important factor for determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluated county

- level emission s d ata for SO 2 and any change in SO 2 emitting activities since the date represented by those emissions data

.

Emissions

EPA recognize s that there might be no new information on any changes in emissions that may

have occurred after 2008, but would consider m ore recent years if available

. Pennsylvania did28

not provide updated emissions information, therefore EPA relied on the 2008 NEI emissions data (NEI08V 2 )

.

Table 8 shows total emissions of SO 2 in tons per year (tpy ) for violating and potentially contributing counties in and around the Indiana County Area in Region III and sources emitting greater than 100 tpy of SO 2 according to the 2008 NEI.

Table 8

. SO 2 Emissions in the Indiana Nonattainment Area

County Faci lity

Located in

State

Recommended

Nonattainment

Area? Facility Total Facility

SO 2 Emissions (tpy) Total

County

SO 2 Point

Emissions (tpy) Name EIS Coordi na tes

Indiana

, PA Yes Homer City Generating

Station 3005211 40.511,

- 79.1968 102,486 124,326

Indiana

, PA Yes Seward Generating

Station 3005111 40.4081,

- 79.0339 15,549 124,326

Indiana

, PA Yes Genon Conemaugh

Plant 2905911 40.3842,

- 79.0611 6,286 124,326

Armstrong

, PA No Keystone

Power

Station 3866111 40.6604,

- 79.3411 189,983 211,810

Cambria

, PA No Colver

Power Project 6594411 40.550378,

- 78.804741 2,576 7,183

Cambria

, PA No Cambria Cogen 6594511 40.4767,

- 78.7067 2,782 7,183

Cambria

, PA No Ebensburg Cogen 6594311 40.455,

- 78.7472 1,815 7,183

Blair , PA No Norfolk

Southern Railway Co/

Juniata

Locomotive Shops 4730711 40.53289,

- 78.38533 392 3,955

Q /d Screening Analysis

Using point source emissions data, the emissions by distance (Q/d) screening methodology was used to identify sources for further review within 50 kilometers (km) of a violating monitor in

Indiana County

. A total of eight point sources emitting more than 100 tpy (from the 2008 NEI

v 2 ) are located within 50 km of the monitor in Indiana County. Of these eight point sources,

there are three sources each located in Cambria and Indiana counties and one source each in Armstrong and Blair C ounties. Following the Q/d methodology, we determined that seven of the eight sources should be further reviewed

. These sources are Keystone, Homer City Gener ating29

Station, Seward Power Plant, Conemaugh, Colver Power P roject , Cambria Cogen, and Ebensburg Cogen ( Figures 19

- 20)

.

Figure 19

.

Figure 20

.30

CAMD Emissions Analysis

Emissions from sources included in EPA’s CAMD database ( http://camddataandmaps.epa.gov/gdm/index.cfm?fuseaction=emissions.wizard ) were reviewed to see if more recent emissions are available for sources near the Indiana County, PA monitor. Nearly all of the emission sources within 50 km of the Indiana County monitor are included in the CAMD data base since the monitor is essentially surrounded by electric

- generating units.

Table 9

. CAMD 2008

- 1 1 Emissions Summary of SO 2 Emissio ns in tpy

Facility County Distance * CAMD

2008 CAMD

2009 CAMD

2010 CAMD

2011

Colver Power Project Cambria 10.3 Not

Available 30,759 2,901 2,881

Ebensburg Cogen Cambria 18.9 Not

Available 2,044 2,404 1,937

Seward Power Plant Indiana 19.8 7,771 7,756 8,458 7,003

Cambria Cogen Cambria 20.4 Not

Available 6,947 2,070 1,942 Conemaugh Indiana 23.2 6,282 7,222 7,056 7,189 Homer City Generating

Station Indiana 24.1 102,484 101,334 112,951 83,596 Keystone Armstrong 37.1 189,994 113,137 39,114 46,441

*Distance from Indiana County, PA SO 2 monitor in kilometers.

Emissions Controls

Under this factor, the existing level of control of emission sources is taken into consideration. The emissions data used by EPA in this technical analysis represent s emiss ions levels while accounting for any control strategies implemente d on stationary sources in the Indiana Area up to and including 2008

. Although EPA has not received any additional information on emissions reductions resulting from controls put into place after 2008

, EPA has collected additional

information from the 2008 NEI and CAMD

.

Our review of the coal

- fired EGU sources within 50 km of the Indiana County monitor indicates

that all of the facilities have some sort of SO 2 emission controls curr ently operating or planned to be operating (as of 2010). Only two sources were projected to have controls installed after 2008 (Keystone and Homer City). According to EPA’s National Electric Energy Data System (NEEDS) database ( http://www.epa.gov/airmarkt/progsregs/epa

ipm/BaseCasev410.html#needs )

, the only uncontrolled units within 50 km of the Indiana County monitor are two units at Homer City (see Table 10 below).31

Table 1 0

. Summary of Controls Within 50 km of Strongstown Monitor (from NEEDS database)

Plant Name Unit

ID County Capacity

(MW) On

Line

Year Modeled

Fuels Wet/DryScrubber Scrubber

Online
Keystone 1 Armstrong 850 1967 Bituminous Wet Scrubber 2009
Keystone 2 Armstrong 850 1968 Bituminous Wet Scrubber 2009
Cambria Cogen B1 Cambria 44 1991 Waste Coal Reagent Injection
Cambria Cogen B2 Cambria 44 1991 Waste Coal Reagent Injection

Colver Power Project ABB01 Cambria 110 1995 Waste Coal Reagent Injection
Ebensburg Power 031 Cambria 49.5 1990 Waste Coal Reagent Injection
Conemaugh 2 Indiana 850 1971 Bituminous Wet Scrubber 1995
Conemaugh 1 Indiana 850 1970 Bituminous Wet Scrubber 1994 Homer City

Station 1 Indiana 620 1969 Bituminous

Homer City

Station 2 Indiana 614 1970 Bituminous Homer City

Station 3 Indiana 650 1977 Bituminous Wet Scrubber 2001

Seward 1 Indiana 260.5 2004 Waste Coal Dry Scrubber 2004

Seward 2 Indiana 260.5 2003 Waste Coal Dry Scrubber 2004

Meteorology (weather/transport patterns)

Evidence of source

- receptor relationships between specific emissions sources and high SO 2 values at violating monitors is another important factor in determining the appropriate contributing areas and the appropriate extent of the nonattainment area boundary. For this factor,

EPA considered data from sites that collected hourly averaged wind measurements including wind direction and speed for 5 years. There is only one ASOS site located within 50 km of the Indiana County monitor. The closest surface site is the John Murtha Johnstown

- Cambria County Airport located approximately 30 kilometers south

- southeast of the Indiana County monitor. The closest rawinsonde site is located at the Pittsburgh International Airport located approximately 105 km west of the Indiana County monitor.

One

- minute meteorological wind fields for the Johnstown

- Cambria County Airport site were downloaded and run through AERMOD’s preprocessor AERMINUTE to produce hourly averaged wind fields. This data was then run through Lakes Environmental’s WRPLOT software to produce wind roses for the Johnstown

- Cambria County Airpor t ( Figure 21 ). Predominant winds generally ranged from the west over the 2006

- 10 time period. Given this information, EPA is not prepared to conclude that large sources in Cambria County (ie. Colver Power Plant, Cambria Cogen, and Ebensburg Cogen) are li kely contributing to the violating monitor in Indiana County.32 Figure 21

.

Geography/topography (mountain ranges or other air basin boundaries)

Figure 22 below depicts elevations and locations of point sources near Indiana County. Indiana County is located east of Pittsburgh in the Allegheny Mountains. The Conemaugh River forms the southern boundary of the county. Terrain elevations generally rise as yo u move east culminating along the Chestnut Ridge that marks the eastern boundary of Indiana County. Elevations rise above 600 meters along this ridge with the highest elevations in Pennsylvania located in neighboring Cambria and Somerset Counties.33 Figure 22

.

Jurisdictional boundaries

There is no existing nonattainment/maintenance boundary for the previous 1971 primary SO 2 NAAQS for the Indiana Area and Indiana County is not part of any MSA (as of 2009) but is designated as a separate Micropolitan Statistical Area. There is another possible boundary, however, that can be considered: the Southwest Pennsylvania Intrastate AQCR, codified i n the Code of Federal Regulations (CFR) § 81. 23

. The Southwest Pennsylvania Intrastate AQCR consists of Allegheny, Armstrong, Beaver, Butler, Fayette, Greene, Indiana, Washington and

Westmoreland C ounties ( Figure 2 3 ). The Southwest Pennsylvania Intrastate AQC R does not

include all of the counties that lie within 50 km of the Indiana County monitor and includes areas

with sources which EPA is not prepared to conclude are likely to contribute to the violating

monitor in Indiana County . For these reasons it would not be practical to use this AQCR as the

i nitial nonattainment boundary.34 Figure 2 3

.

Other Information

There have been a number of studies of the Chestnut Ridge area due to the number of large coal

fired power plants in the region. One of the earliest studies was done by the US Department of Health, Education and Welfare in 1970 (Large Power Plant Effluent Study (LAPPES), National Air Pollution Control Administration). A general description of the region’s coal fired power plants from this report is included here:

“[T]hree new mine

- mouth stations, Keystone, Homer City and Conemaugh are located approximately equidistant al ong a NW

- SE line 39 kilometers long about 80 kilometers ENE of Pittsburgh. These three stations, combined with the nearby Seward and Shawville stations, form a complex whose total annual production of 47,380,305 megawatt hours exceeds the total electrical output of all but 11 nations of the world.”

M odeling analys e s concerning power plants in the Chestnut Ridge region w ere conducted in the

1990s and in 2003 at the behest of PADEP to examine compliance with the SO 2 NAAQS

. 1 The resulting report s examined i mpacts on the Chestnut Ridge from some of the larger power plants that lay to the west. A quick check of plant elevations and stack heights revealed that stack tops at Homer City and Keystone are roughly in line with the elevations at the Strongstown SO 2

1 “AERMOD Modeling Analyses for SO 2 NAAQS Compliance for Power Plants in the Laurel Ridge and Chestnut Ridge Region of Pennsylvania (TRC Project No. 33275),” March 2003; Prepared by RC Environmental Corp.35

monitor as well as the rest of the Chestnut Ridge. This suggests that violations could be occurring in most of the elevated terrain in eastern Indiana County due to emissions from these power plants.

Conclusion for the Indiana Nonattainment Area

After considering the factors described above, EPA intends to find that it is appropriate to initially include , based on the violating monitor, Indiana County and a portion of Armstrong County (Table 1) in the Indiana N onattainment A rea for the 2010 SO 2 NAAQS

. The air quality

monitor in Indiana County shows a violation of the 2010 SO 2 NAAQS, based on 200 9

- 201 1 air quality data. The nearby Keystone Plant in neighboring Armstrong County likely contributes to nonattainment in Indiana County as well

. Previous stud ies have shown that stack tops (of Homer City and Keystone) are at elevations in line with that of the Strongstown monitor in Indiana County. Meteorological data suggests that emissions from large sources west of the monitor likely impact the monitor and contribute to SO 2 NAAQS violations in Indiana County. Based on the consideration of all the relevant and available information, as described above, EPA believes

that the initial boundaries described herein encompass the area that should be initially desig nated as nonattainment due to causing or contributing to the monitored violation of the 2010 SO 2 NAAQS in the county

.

Figure 24.36

Technical Analysis for the Warren Nonattainment Area

This technical analysis for the Warren Nonattainment A rea identifies the whole county with a

monitor that violates the 2010 SO 2 NAAQS, and evaluates nearby counties for contributions to

SO 2 concentrations in the area. For this area, Warren County has a violating monitor. EPA has

evaluated this count y and al l other surrounding counties based on the factors recommended in the March 24, 2011 guidance issued by EPA.

Based on EPA's technical analysis described below, EPA agrees with Pennsylvania’s recommendation and intends to designate Warren County in Pennsy lvania as nonattainment for

the 2 010 SO 2 NAAQS as part of the Warren N onattainment A rea

.

Air Quality Data

This factor considers the SO 2 air quality monitoring data, including the design value (in ppb)

calculated for the air quality monitor in Warren County in the Warren Area based on certified

data for the 200 9

- 20 1 1 period

. Fig ure 2 4 depicts the area analyzed and the location of the violating air quality monitor

.

Figure 2 5

.37

The 2010 1

- hour SO 2 design value for the monitor located in Warren County is shown in Table

1 1

.

Table 11. Warren County Monitor Trend : 1

- Hour SO 2 99 th % and Design Value in Parts Per Billion (ppb)

Monitor Name Monitor

Air Quality System ID 99 th % Design

Value Design

Value

2007 2008 2009 2010 2011 2008

- 10 2009

- 11

Warren 42

- 123

-

0004 153 146 113 109 94 123 105

One

- hour SO 2 design values at the Warren County monitor have fallen slightly over the last four years. This decline may be attributed to the recent economic recession, which started in 2008. Any statistical trend that could be gleaned from the monitor data, however, should be viewed with caution due to the minimal amount of data currently available.

Emissions and Emissions

- Related Data

Evidence of SO 2 emissions sources in the vicinity of a violating monitor is an important factor for determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluated county

- level emission s data for SO 2 and any change in SO 2 emitt ing activities since the date represented by those emissions data

.

Emissions

EPA recognize s that there might be no new information on any changes in emissions that may

have occurred after 2008, but would consider more recent years if available

. Pennsyl vania did not provide updated emissions information, therefore EPA relied on the 2008 NEI emissions data (NEI08V 2 )

.

Table 12 shows total emissions of SO 2 in tons per year (tpy) for violating and potentially contributing counties in and around the Warren Area in Region III and sources emitting greater than 100 tpy of SO 2 according to the 2008 NEI.

Table 12

. SO 2 Emissions in the Warren Nonattainment Area

County Facility

Located in

State

Recommended

Nonattainment

Area? Facility Total Facility SO 2 Emissions (tpy) Total

County SO 2 Point

Emissions (tpy) Name EIS Coordinates

Warren , PA Yes United Refining

Warren

Plant 4966711 41.82992,

- 79.12444 1,612 1,61638

McKean,

PA No American Refining Group/

Bradford 6532511 41.96686,

- 78.63013 1,479 3,372

Chautauqua,

NY No Samuel A.

Carlson Generating

Station 7806011 42.093543,

- 79.247679 3,736 14,412

Q /d Screening Analysis

Using point source emissions data, the emissions by distance (Q/d) screening methodology was used to identify sources for additional review within 50 km of a violating monitor in Warren County

. A total of three point sources emitting more than 100 tpy (from the 2008 NEI v 2 ) are

located within 50 km of the monitor in Warren County. Sources are located in Warren and

McKea n counties in Pennsylvania and Chautauqua County, NY. Following the Q/d methodology, we determined that all three sources should be further reviewed

. These sources are United Refining Warren Plant, American Refining Group

- Bradford, and Samuel A. Carlson Generating Station ( Figures 2 6

- 2 7 )

.

Figure 2 6.39 Figure 2 7

.

CAMD Emissions Analysis

Emissions from sources included in EPA’s CAMD database ( http://camddataandmaps.epa.gov/gdm/index.cfm?fuseaction=emissions.wizard ) were reviewed to see if more recent emissions are available for sources near the Warren County, P A monitor. Only the Samuel A. Carlson Generating Station in Chautauqua County, NY reported its SO 2 emissions to CAMD.

Table 13

. CAMD 2008

- 1 1 Emissions Summary of SO 2 Emissions in tpy

Facility County Distance * CAMD

2008 CAMD

2009 CAMD

2010 CAMD

2011

Samuel A. Carlson Generating Station Chautauqua 28.41 3,736 1,885 1,272 664 *Distance from Warren County SO 2 monitor in kilometers.

Emissions Controls

Under this factor, EPA considers the existing level of control of emission sources. No SO 2 emission controls were noted on any of the sources within 50 kilometers of the Warren County

monitor.40

Meteorology (weather/transport patterns)

Evidence of source

- receptor relationships between specific emissions sources and high SO 2 values at violating monitors is another important factor in determining the appropriate contributing areas and the appropriate extent of the nonattainment area boundary. For this factor,

EPA considered data from sites that collected hourly averaged wind measurements including wind direction and speed for 5 years. There is only one ASOS site located within 50 km of the Warren County monitor. The closest surface site is the Bradford Regional Airport located approximately 44 kilometers east

- southeast of th e Warren County monitor. The closest rawinsonde site is located at the Buffalo Niagara International Airport located approximately 130 km north of the Warren County monitor.

One

- minute meteorological wind fields for the Bradford Regional Airport site wer e downloaded and run through AERMOD’s preprocessor AERMINUTE to produce hourly averaged wind fields. This data was then run through Lakes Environmental’s WRPLOT software to produce a wind rose for the site ( Figure 2 8 ). Winds at the Bradford Regional Airp ort showed a bimodal distribution with the predominant winds coming from the west to northwest with a second distribution coming from the southeast direction during the 2006

- 10 time period. Given this information, EPA is not prepared to conclude that the large source in McKean County (i

. e.
, American Refining Group) is likely to be advers e ly impacting the monitor in Warren County.

Pennsylvania’s recommendation provided meteorological information from the Warren monitoring location, which is situated with in a valley approximately 4 kilometers west of United Refining. Their analysis shows that high SO 2 concentrations at the monitoring site are likely driven by the source that is within close proximity to the air monitor.

Figure 2 8

.41

Geography/topography (mountain ranges or other air basin boundaries)

Figure 29 below depicts elevations and locations of point sources in the Warren County area. Warren County is located in northwest Pennsylvania in the state’s Allegheny Plateau Region. The area is made up of dendritic river valleys cut by the Allegheny River and its tributaries interspersed with higher terrain. Elevations vary from over 600 meters above mean sea level along the plateau to just under 325 meters along the Allegheny River as it drains south into Forest County. Higher terrain lies to the west in McKean County with elevations generally decreasing as one moves west towards Lake Erie.

Pennsylvania’s recommendation noted the influence of local topography on the Warren County

monitor. Their anal ysis examined the monitored wind fields and the timing of exceedances and concluded that local topographically

- induced meteorological conditions, mainly overnight inversions and complex drainage flows, coupled with a nearby local source contributed to the monitor’s noncompliance with the 1

- hour SO 2 NAAQS. Given this information, EPA is not prepared to conclude that emissions from the Samuel A. Carlson Generating Station in Chautauqua County, NY nor American Refining

- Bradford in McKean County, PA are likely to contribute to the violating monitor in Warren County, PA.

Figure 29

.42

Jurisdictional boundaries

There are two existing maintenance boundar ies (i

. e.
, previous nonattainment areas) in Warren County for the 1971 primary SO 2 NAAQS . One consists of Warren Borough, Pleasant Township, and Glad Township, while the other consists of only Conewango Township. These

boundaries are not appropriate boundaries because they are too small and would not include large sou r ces that are likely to contribute to nonattainment in Warren County

.

Although Warren County is not part of an y MSA (as of 2009) and is designated as a separate

MSA , t here is another possible boundary that can be considered: Northwest Pennsylvania

Youngstown Interstate AQCR, c odified in the Code of Federal Regulations (CFR) § 81. 74

. The Northwest Pennsylvania

- Youngstown Interstate AQCR consists of fourteen counties in Pennsylvania and Ohio: Cameron, Clairion, Clearfield, Crawford, Elk, Erie, Forest, Jefferson,
Lawrence, McKea n, Mercer, Potter, Venango, and Warren Counties in PA, along with Ashtabula, Mahoning and Trumbull Counties in Ohio ( Figure 30 ). The Northwest Pennsylvania

Youngstown Interstate AQCR does not include all of the counties that lie within 50 km of the

Warren County monitor and includes areas with sources which EPA is not prepared to conclude

are contribut ing to the violating monitor. For these reasons

, it would not be practical to use this AQCR as the initial nonattainment boundary.

Figure 30

.43

Conclusion for the Warren Nonattainment Area

After considering the factors described above, EPA intends to find that it is appropriate to

include , based on the violating monitor, Warren County in the Warren N onattainment A rea for

the 2010 SO 2 NAAQS

. The air quality monitor in Warren County shows a violation of the 2010

SO 2 NAAQS, based on certified 200 9

- 201 1 air quality data. EPA is not prepared to find that any nearby areas contribute to the monitored violations in Warren County. The monitor in Warren County, based on certified 200 9

- 201 1 air quality data, show s high concentrations of SO 2 emissions in the vicinity

, and both m eteorological and topographical data suggest that emissions

from the large source within close proxi mity of the monitor likely impact the monitor and

contribute to SO 2 NAAQS violations in Warren County. Additionally, EPA is not prepared to conclude that, based on m eteorological and topographical data

, the large source s in neighboring counties are likely to impact the monitor in Warren County. The monitored violation in Warren County is likely driven by the source within close proximity of the monitor (i.e. United Refining

Warren Plant )

. Based on the consideration of all the relevant and available infor mation, as described above, EPA believes that the boundaries described herein encompass the appropriate

initial area that does not meet the 2010 SO 2 NAAQS

.

Figure 3 1

.44 EPA’s Area Designations Conclusion for Pennsylvania

EPA has reviewed the information above and intends to find that it is appropriate to designate

based on monitored violations the counties and/or portions of counties liste d in Table 1 as

nonattainment for the 2010 SO 2 NAAQS. EPA intend s to designate Allegheny, Beaver, Indiana

, Warren Counties

, and a portion of Armstrong County ( Plumcreek and South Bend Townships and Elderton Borough ) as nonattainment after considering the factors and information described in this technical support document . The intended nonattainment area boundaries that EPA

describes above are based on the five factors which include: air quality data, emissions

- related data, meteorology, geography/topography, and jurisdictional boundaries. Based on the

consideration of all the relevant and available information, as described above, EPA believes that the boundaries described herein encompass the area that does not meet (or that contributes to ambient air quality in a nearby area that should be initially designated as nonattainment due to causing or contributing to the monitored violation of the 2010 SO 2 NAAQS in the county

.