1 Draft Technical Support Document

I llinois

Area Designations For the

2010 SO 2 Primary National Ambient Air Quality Standard

Summary

Pursuant to section 1 07(d) of the Clean Air Act , EPA must initially designate areas as either “unclassifiable”, “attainment”, or “nonattainment” for the 2010 one

- hour sulfur dioxide (SO 2 ) primary national ambient air quality standard (NAAQS)

. The Clean Air Act defines a

nonattainment area as one that does not meet the NAAQS or that contributes to a violation in a nearby area

.

Illinois submitted recommendations on June 2 , 2011

. Table 1 below lists Illinois’s

recommendations and identifies the counties or portions of counties in Illinois that EPA intends to designate “nonattainment” based on monitored violations

.

Table 1

. Nonat tainment Area Designation s for Illinois

Area Illinois Recommended Designation of Areas/

Counties EPA's Intended Designation of Areas/

Counties

Pekin , IL

Tazewell County (part ial )

- Cincinnati Township

,

- Pekin Township

Peoria County (part ial )

- Hollis Township Nonattainment

Unclassifiable Nonattainment

Nonattainment

Lemont

, IL Cook County (part ial )

- Lemont Township Will County (part ial )

- Dupage Township

- Lockport Township Nonattainment

Nonattainment Nonattainment

Nonattainment2 Background

On June 3 , 2010, EPA revised the primary SO 2 NAAQS (75 FR 35520, published on June 22, 2010)

. EPA revised the primary SO 2 standard by establishing a new one

- hour standard at a level

of 75 parts per billion (ppb) which is attained when the three

- year average of the 99 th percentile

of one

- hour daily maximum concentrations 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 children, the elderly and those with asthma. These groups are particularly

s usceptible to the health effects associated with breathin g SO 2

. EPA is revoking the two prior primary standar ds of 140 ppb evaluated over 24 hours, and 30 ppb evaluated over an entire year because they will not add additional public health protection given a one

- hour standard at 75 ppb. Ac cordingly, EPA is not designati n g areas in this process on the basis of either of these two primary standards. Similarly, the secondary standard for SO2 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 Clean Air Act requires that not later than one year after promulgation of a

new or revise d NAAQS, state Governors must submit their recommendations for designations

and boundaries to EPA by June 2011. Section 107(d) also requires EPA to provide notification

to states no less than 120

- days prior to promulgating an initial area designation that is a

modification of a state’s recommendation

. EPA was to promulgate initial area designations

within t wo years of promulgation of the revised primary standard , although EPA has extended this deadline for one additional year due to having insufficient information to promulgate the designations

. If a state did not submit designation recommendations, EPA wil l promulgate the designations that it deems appropriate

. If a state or tribe disagrees with EPA’s intended designations, they have an opportunity to demonstrate why any proposed modification is inappropriate.

Designations guidance was issued by EPA throu gh 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 identifies factors EPA intends to evaluate in determining boundaries f or areas designated nonattainment. These five factors include: 1) a ir quality data; 2) e missions and emissions

- related data (location of sources and potential contribution to ambient SO 2 concentrations) ; 3) m eteorology (weather/transport patterns); 4) g eography/topography (mountain ranges or other air basin boundaries); and 5) j urisdictional boundaries (e.g., counties, air districts, pre

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

- hour SO2 NAAQS

.

The March 24, 2011

, memo recommended that area boundaries default to the county boundary unless

information provided by the state or tribe justif ies a large r 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 differing boundary tha n a county boundary.3

In this technical support document , EPA discusses its review and technical analysis of the

recommendations regarding areas with monitored violations submitted by Illinois for designations for

the one

- hour SO 2 standard and any modifications from these recommendations.

Definition of important terms used in this document:

1) Designated nonattainment area

– an area which EPA has determined, based on a s tate
recommendation and/ or on the technical analysis include d in this document, has violat ed 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.

2 ) Recommended nonattainment area

– an area a s tate or t ribe has recommended that EPA designate as nonattainment.

3 ) Violating monitor

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

4 ) 20 10 SO 2 NAAQS

– The NAAQS for SO 2 promulgated in 20 10

. This NAAQS is 75 ppb,

b ased on the three year average of the 99th percentile of the annual distribution of daily

maximum one

- hour average concentrations. See 40 CFR Part 50.17.

5) Design Value

- a statistic computed according to the data handling procedures of the NAAQS (in 40 CFR 50 Appendix T) that , by comparison to the level of the NAAQS , indicates whether the area is violating the NAAQS

.

Technical analysis for the Lemont , IL Area

Introduction

Th is technical analysis for the Lemont, IL area identifies Cook C ount y with a monitor , in
Lemont, 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

evidence for the factors recommended in the March 24, 2011 EPA guidance

.

Figure 1 is a map of the area showing the location s and design value s of air quality monitor s in the area, and the counties surrounding any violating air quality monitors

. Notably, a monitor in

Lemont Township in Cook County recorded a 200 9 to 2011 design value of 98 ppb. Multiple other monitors in Cook County and a monitor in Will County showed design values below the

stand ard, with values ranging from 18 to 30 ppb.4

Figure 1

. Map of sources and monitors in the Chicago area and the intended Lemont , IL

nonattainment area

Illinois analyzed the sources that might be contributing to the monitored violation in Lemont.

Based on this assessm ent, Illinois recommends that an area consisting of DuPage and Lockport Townships in Will County and Lemont Township in Cook County be designated as

nonattainment. This recommendation reflects Illinois’ view that no significant sources are located in Cook County near Lemont but that three significant sources are located nearby in Will County.

Based on EPA's technical analysis described below, EPA is intending to designate a Lemont nonattainment area consisting of Lemont Township in Cook County and DuPage and Lockport Townships in Will County a s nonattainment for the 2 010 SO 2 NAAQS

.

Detailed Assessment

Air Q uality D ata

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

calculated for all air quality monitors in the Chicago metropolitan area based on data for the

200 9

- 20 11 period

.

The 2010 SO 2 NAAQS design values for the Chicago area within Illinois are shown in Table 2

.5

Table 2

. Air Quality Data in the Chicago Area

County State Recommended

Nonattainment? Monitor Air Quality System ID Monitor Location SO 2 Design Value,

200 9

- 20 1 1 ( ppb )

Cook No 17

- 031

- 0050 41.7076, 87.5686 20

No 17

- 031

- 0063 41.877, 87.6343 18

No 17

- 031

- 0076 41.7514, 87.7135 2 4

Yes 17

- 031

- 1601 41.6681, 87.9906 98

No 17

- 031

- 4002 41.8552, 87.7525 3 0

No 17

- 031

- 4201 42.1400 , 87.7992 18 *

Will No 17

- 197

- 0013 41.46, 88.182 28

*Data are incomplete. Value is determined from available data for instrument identified as POC 2. Monitors in Bold have the highest 2009

- 2011 design value in the respective county.

The Lemont monitor in Cook County show s a violation of the 2010 SO 2 NAAQS

.

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 data for SO 2 and any growth in SO 2 emitting activities since the date represented by those emissions d ata

.

Emissions

The most recent year for which national emissions information was compiled was 2008. Illinois did not provide more recent emissions information

. T herefore

, EPA relied on the 2008 N ational

E missions I nventory (NEI) emissions data (NEI08V 2 )

.

Table 3 shows total emissions of SO 2 (given in tons per year) for Cook County and for adjoining Will County. Table 3 also shows pertinent information for s ources in these counties emitting greater than 100 ton s per year of SO 2 according to the 2008 NEI

.6

Table 3 . SO 2 Emission s in the Chicago Area (NEI08V 2 )

County Facility in

State

Recommen

ded N.A.

Area ? Facility Emissions

NEI08V15 (tons per year) Facility Location Distance

to

Lemont

Monitor (km) Total County

SO 2 Emissions (tons per year)

Cook No Crawford Station 6,627 tpy 41.8278, 87.7236 28 20,562

No Fisk Station 4,486 tpy 41.8408, 87.6533 34

No Corn Products 2,203 tpy 41.7751, 87.8224 18

No Koppers 823 tpy 41.8206, 87.7487 26

No O’Hare Airport 511 tpy 41.9772, 87.9044 35

No Saint

- Gobain

Containers 345 tpy 41.6439, 87.6003 32

No Carmeuse Lime 321 tpy 41.7056, 87.5438 37

No Midway Airport 114 tpy 41.785, 87.7519 24

Will No MWG Joliet Station 18,281 tpy 41.4947, 88.125 22 64,126

Yes MWG Will County

Station 16,497 tpy 41.6344, 88.0592 7

No Exxon Mobil 16,404 tpy 41.4138, 88.1835 33

Yes Oxbow Midwest

Calcining 6,205 tpy 41.6622, 88.0379 4

Yes CITGO Petroleum 6,137 tpy 41.6444, 88.0559 6

The sources in Cook County are at considerable distances from the violating monitor. For example, the closest source is Corn Products Corporation, at about 18 kilometers from the monitor, with emissions of about 2

, 300 tons per year, and the highest emitti ng source in Cook County, Midwest Generation’s Crawford Station, is about 28 kilometers away, emitting about

6

, 600 tons per year. These sources are at sufficient distance from the monitor, with sufficiently low emissions, for EPA to judge, as recommended by Illinois

, that these sources do not

contribute significant ly to the monitored violation at the Lemont monitor.

Three of the sources in Will County are relatively close to the Lemont monitor and have

sufficient emissions that Illinois recommended incl uding the townships containing these sources

in the Lemont nonattainment area. Midwest Generation’s Jolie t Station and the Exxon

- Mobil refinery are sufficient distance and do not have sufficiently high emissions to warrant being

included in this nonattainment area based on the monitored violation

.

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 3 represent emissions levels taking into account any control strategies implemented on stationary sources in

this area up to and including 2008. EPA has not received any additional information on emissions reductions resulting from controls put into place after 2008.7

Meteorology (weather/transport patterns)

When considering a one

- hour standard, violations can occur at anytime, even when weather patterns are varied from the normal trends of the ar ea. For this area, wind s can be from any

direction. Theref

ore, for a one

- hour standard, it is useful to consider all directions to have potential contribution. Nevertheless, according to wind information provided with Illinois’
recommendations, winds in this area come from the west and southwest more frequently than from other quadrants, particularly when concentrations are high at the Lemont monitor, so sources to the west and southwest of the Lemont monitor are most likely to contribute to

violations at this monitor.

Geography/topography (mountain ranges or ot her air basin boundaries)

The Chicago area does not have any geographical or topographical barr iers significantly limiting

air pol lution transport within its air shed. Therefore, this factor did not play a significant role in determining the nonattainment boundary.

Jurisdictional boundaries

Illinois does not have any current SO 2 nonattainment areas . Townships in Illinois have well

established boundaries and are a suitable basis for defining nonattainment areas.

Other Relevant Information

EPA did not receive additional information relevant to establishing a nonattainment area boundary for this area

.

Conclusion

Illinois has adequately justified a nonattainment area

, based on the violating monitor in Cook County

, that includes the township that contains the monitoring site and two townships in Will County, DuPage and Lockport Townships , that are judged to contribute to the monitored violation. In judging the area to be included in the Lemont nonattainment area based on the violation recorded at the Lemont monitor, EPA judged that sources in Cook County outside Lemont Township, as well as the Midwest Generation Joliet plant and the Exxon

- Mobil refinery in Will County, are sufficiently distant from the violating monitor t o warrant being excluded

from this nonattainment area.8 Technical analysis for the Pekin , IL Area

Introduction

This technical analysis for the Pekin , IL area identifies a Tazewell C ount y monitor that violate s the 2010 SO 2 NAAQS

. EPA has evaluated this county and nearby counties based on the

evidence for the factors recommended in the March 24, 2011 EPA guidance

.

Figure 2 is a map of the are a showing the location and the design value of the air quality monitor in the area, and the counties surrounding this air quality monitor

. The monitor in Pekin (Tazewell County) recorded a 2 009 to 2011 design value of 2 11 ppb. A monitor in Peoria County recorded a 2009 to 2011 design value of 36 ppb, based on incomplete data. No other

SO 2 mon itor is located in these or any neighboring counties

.

Figure 2

. Map of sources, monitors, and intended nonattainment area boundaries in the Pekin , IL

area

Illinois analyzed the sources that might be contributing to the monitored violation in Pekin

. Based on this assessment, Illinois re commended that an area consisting of Cincinnati and Pekin Townships in Tazewell County be designated as nonattainment.

EPA believes that Hollis Township in Peoria County also contributes to the violation monitored

i n Taz e well County

. E.D. Edwards Station, a power plant operated by Ameren , is located in this9

township. Th is source emits approximately 11 ,000 tons of SO 2 per year , in a location that is

about 4.5 kilometers in a direction that is periodically upwind of the Pekin monitor.

Based on EPA's technical analysis described below, and based on a monitored violation, EPA is intending initially to designate a Pekin nonattainment area consisting of Cincinnati and Pekin Township s in Tazewell County and Hollis Towns hip in Peoria

.

Detailed Assessment

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 Tazewell County based on data for the 200 9

- 20 11 period

. The only other monitor in this part of Illinois is located in Peoria County. The 2010 SO 2 NAAQS des ign value s for the Tazewell and Peoria County monitor s are shown in Table 4

.

Table 4 . Air Quality Data in the Pekin Area

County State Recommended

Nonattainment? Monitor Air Quality System ID Monitor Location SO 2 Design Value,

2009

- 2011 ( ppb )

Peoria No 17

- 143

- 0024 40.6874 , 89.6069 36

Tazewell Yes 17

- 179

- 0004 40.5565, 89.654 2 11

The Tazewell County monitor show s a violation of the 2010 SO 2 NAAQS. Therefore

, some area in this county and possibly additional areas in surrounding counties must be designated

nonattainment

. The absence of a violating monitor alone is not a sufficient reason to eliminate nearby counties as candidates for nonatta inment status.

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 data for SO 2 and any growth in SO 2 emitting activities since the date represented by those emissions data

.

Emissions

The most recent year for which national emissions information was compiled was 2008 . Illinois reported data indicating that emissions from pertinent sources in 2007 and 2009 were similar to

emissions in 2008. T herefore

, EPA relied on the 2008 N ational E missions I nventory (NEI)

emissions data (NEI08V 2 ).

Table 5 shows total emissions of SO 2 (given in tons per year) for Tazewell County and for adjoining Peoria County. Table 5 also shows pertinent information for sources in these counties emitting greater than 100 ton s per year of SO 2 according to the 2008 NEI.10

Table 5 . SO 2 Emission s in the Pekin Area (NEI08V 2 )

County Facility Located

in State

Recommended

Nonattainment

Area ? Facility

– Total SO 2 Air

Emissions NEI08V 2 (tons per year) Facility Location Distance

to Pekin

Monitor (km) Total County

SO 2 Emissions (tons per year)

Peoria No * Ameren

– E.D . Edwards

Stn

– 11,224 tpy 40.5958, 89.6631 4 14,677

No ADM

– 3049 tpy 40.6756, 89.6073 14

No Keystone Steel & Wire

–

138 tpy 40.6420, 89.6467 10

Tazewell Yes MWG

– Powerton Stn.

– 22,355 tpy 40.5408, 89.6786 3 34,415

Yes Aventine Renewable

Energy

– 11,830 tpy 40.5553, 89.6629 1

*This source is included in the nonattainment area that EPA intends to promulgate

The two significant sources in Tazewell County are located in Cincinnati and Pekin Townships, respectively, which Illinois has recommended including in the Pekin nonattainment area. Illinois does not recommend including any of Peoria County in this nonattainment area. However, EPA finds that Ameren’s E.D. Edwards power plant is only 4 kilometers from the monitor and has significant emissions with potential to have significant impact on concentrations at the monitor.

Th is source is located in Hollis Township, and so this township warrants being considered an

area that contributes to th e violation measured in Pekin.

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 5 represent emissions levels taking into account any control strategies implemented on stationary sources in

this area up to and including 2008. EPA has not received any additional information on emissions reductions resulting from controls put into place after 2008.

Meteorology (weather/transport patterns)

W hen considering a one

- hour standard, violations can occur at anytime, even when weather patterns are varied from the normal trends of the area. For this area, wind patterns can be from any d irection. Therefore, for a one

- hour standard, it is useful to consider all directions to have potential contribution . The wind rose provided by Illinois suggests that winds come most frequently from the south, and somewhat frequently from the northwest, but winds come from all directions with sufficient frequency to suggest that meteorology is not a significant factor in defining this nonattainment area.11

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

The Pekin area does not have any geographical or topographical barr iers significantly limiting air pol lution transport within its air shed. Therefor e, this factor did not play a significant role in determining the nonattainment boundary.

Jurisdictional boundaries

Illinois does not have any current SO 2 nonattainment areas. Townships in Illinois have well

established boundaries and are a suitable ba sis for defining nonattainment areas.

Other Relevant Information

EPA did not receive additional information relevant to establishing a nonattainment area boundary for this area.

Conclusion

Illinois’ recommendation to define the Pekin , IL nonattainment area to include Cincinnati and Pekin Townships of Tazewell County appropriately include s the portions of Tazewell County that are contributing to the measured violation and the area known to be violating the standard. However, EPA believes that the initial nonattainment area based on monitored violations should

also include Hollis Township in Peoria County , which includes Ameren’s E.D. Edwards Station. This source has substantial emissions relatively close to the monitor measuring a violati on. Therefore, EPA believes that Hollis Township of Peoria County warrants inclusion in the Pekin

nonattainment area. Thus, a fter considering the factors described above, EPA intends initially to designate an area that includes Cincinnati and Pekin Towns hip s in Tazewell County and Hollis Township in Peoria County as the Pekin , IL nonattainment area for the 2010 SO 2 NAAQS

.