1

--------------------------------------------------------------------------------------- ----------------------------- Technical Support Document (TSD)

Illinois 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 designate areas as either

“ nonattainment, ” “attainment

, ” or “ unclassifiable ” for the 2010 one

- 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 meet the NAAQS. Table 1 below identifies the counties or portions of counties (or tribal areas) in Illinois that EPA intends to d esignate “nonattainment” for the primary 2010 SO 2 NAAQS.

Illinois submitted recommendations on June 2, 2011. On February 6, 2013, EPA sent out a letter with intended designations for Illinois

. Illinois did not respond to EPA’s intended designation.

Table 1 below lists Illinois’s June 2, 2011 recommendations and identifies the counties or portions of counties in Illinois that EPA is initially designating “nonattainment” based on

monitored violations

. EPA is not yet prepared to designate other areas i n Illinois, and will address them in subsequent rounds of designation.

Table 1. Nonattainment Area Designations for Illinois

Area Illinois Recommended Designation of Areas/

Counties EPA's 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, June 22, 2010) by establishing a new 1

- hour standard at a level of 75 parts per billion (ppb)

, which is met at an ambient air quality monitoring site when the 3

- year average of the annual 99 th percentile of the daily maximum 1

- hour ave rage concentration at each monitor in an area does not exceed 75 ppb

, as determined in accordance with Appendix T of 40 CFR part 50. 40 CFR 50.17(a)

- (b). EPA has determined that this is the level necessary to provide protection of public health with an

a dequate margin of safety, especially for children, the elderly and those with asthma. These groups are particularly susceptible to the health effects associated with breathing SO 2 . The Agency is revoking the two prior primary standards of 140 ppb evaluat ed over 24

- hours, and 30 ppb evaluated over an entire year because the 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, the 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 provides that not later than 1 year after promulgation of a new or revised NAAQS, state Governors may submit their recommendations for designations and

boundaries to EPA . For the 2010 SO 2 NAAQS, this deadline was June 3, 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. EPA has reviewed the State’s recommendations and has notified the State Commissioner through letter signed by the Regional Administrator of any intended modifications. [While language in section 107 specifically addresses states, we intend to follow the same process for tribes, pursuant to section 301(d) of the CAA and Tribal Authority Rule (40 C FR Part 49). Therefore, we intend to designate tribal areas, in consultation with the tribes, on the same schedule as state designations.] If a State or Tribe did not submit designation recommendations, EPA is to promulgate the designations that it deems appropriate. If a state or tribal government disagrees with EPA’s intended area designations, it had an opportunity to demonstrate why any proposed modification is inappropriate.

Designations guidance was issued by EPA through a March 24, 2011, memoran dum 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 for areas designated nonattai nment. 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) Geography/topography (mountain ra nges or other air basin boundaries); and 5) Jurisdictional boundaries (e.g., counties, air districts, pre

- existing nonattainment areas, reservations, metropolitan planning organization), among any other information deemed relevant to establishing appropria te area designations and boundaries for the 1

- hour SO 2 NAAQS.3

The March 24, 2011, designations guidance memo recommended that area boundaries be defaulted to the county boundary unless additional provided information justifies 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 different boundary than a default county bo undary.

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

- hour SO 2 standard and any modifications from these

recommendations.

Definition of important terms used in this do cument:

1) Designated nonattainment area

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

2010 SO 2 NAAQS, based on the most recent three years of air quality monitoring data from

2009

- 2011, or contributes to a violation in a nearby area.

2 ) Recommended nonattainment area

– an area that a s tate or tribal government has recommended to EPA to be design ated 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 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 qua lity monitors

. Notably, a monitor in4

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 t o 30 ppb.

Figure 1

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

area

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

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

nonattainmen t. This recommendation reflected 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 initially designat ing a Lemont nonattainment area consisting of Lemont Township in Cook County and DuPage and Lockport Townships i n Will County a s nonattainment for the 2 010 SO 2 NAAQS

. Areas and sources that we are not yet prepared to conclude are contributing to monitored violations or to other possible

violations are not included in this initial nonattainment area. Such sources a nd areas will be further addressed in a subsequent round of final designations.5

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

.

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 ( NEI08V3 )

.

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 th e 2008 NEI

.6

Table 3 . SO 2 Emission s in the Chicago Area ( NEI08 V3 )

County Facility in

State

Recommen

ded N.A.

Area ? Facility Emissions

NEI08 V3 (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 19,346

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 498 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 110 tpy 41.785,

- 87.7519 24

Will No MWG Joliet Station 18,281 tpy 41.4947,

- 88.125 22 63,967

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. Based on the distance of these sources from the violating monitor, EPA is not yet prepared to conclude that these sources con tribute to the Lemont monitor ’s design value

. These sources will be further addressed in a subsequent round of designations.

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

sufficient emissions that Illinois reco mmended including the townships containing these sources

in the Lemont nonattainment area. However, considering their emission levels and based on their distance from the monitor, EPA is not yet prepared to conclude that two other Will County

sources, Mid west Generation’s Jolie t Station and the Exxon

- Mobil refinery

, are contributing to

the Lemont monitor ’s design value

. These two sources will also be further addressed in subsequent a round of designations.

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 addit ional information on emissions reductions resulting from controls put into place after 2008.7

Meteorology (weather/transport patterns)

Evidence of source

- receptor relationships between specific emissions sources and high SO 2 values at violating monitors i s another important factor in determining the appropriate contributing areas and the appropriate extent of the nonattainment area. Figure 2 shows the prevalent wind direction for the Lemont, IL area.

Figure 2: Wind Rose for Lemont, IL

Source: IEPA Software: WRPLOT

- Lakes Environmental Software

The wind rose above shows that winds are most likely to come from the south , west, and

southwest directions, but also frequ ently come from all the north east direction, and occasionally

from the other directions. This shows that a source from any direction could contribute to the

violation at the monitor. The three largest nearby emitters

, MWG Will County Station , Oxbow Midwest Calcining, and CITGO Petroleum

, are located to the west and southwest of t he monitor, which are the frequent wind directions.

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

The Lemont 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 under the prior SO 2 NAAQS

. Townships in Illinois have well established boundaries and are a suitable basis for defining

nonattainment areas.8

Other Relevant Information

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

.

Conclusion

Illinois has adequately justified a n initial nonattainment area

, based on the violating monitor in Cook County

, which includes the Lemont T ownship contain ing the monitoring site and two townships in Will County, DuPage and Lockport Township s
, with sources that contribute to the

monitored violation. Based on the distance from the violating monitor and wind rose analysis,

EPA is not yet prepared to conclude that other sources in Cook County outside Lemont Township , as well as the Midwest Gener ation Joliet plant and the Exxon

- Mobil refinery in Will County, contribute to the Lemont monitor ’s design value . In a subsequent round of designations, EPA will make final designations decisions for areas and sources that are not currently included

in the initial nonattainment area designation addressed in this TSD.

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 3 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 monitor is located in these or any neighboring counties

.9

Figure 3

. Map of sources, monitors, and 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

in Taz e well County

. E.D. Edwards Station, a power plant operated by Ameren , is located in this 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 violatio n, EPA is initially designating a Pekin nonattainment area consisting of Cincinnati and Pekin Township s in

Tazewell County and Hollis Township in Peoria County

. Areas and sources that we are not yet prepared to conclude are contributing to the monitored v iolations are not included in this initial

nonattainment area. Such areas and sources will be addressed in a subsequent round of final designations.

EPA received comments from Ameren and from the Illinois Environmental Regulatory Group objecting to the inclusion of Hollis Township in the nonattainment area, as well as comments from Citizens Against Ruining the Environment and the Respiratory Health Ass ociation generally supporting the intended designation. These comments are addressed in more detail in the response to comments document.10

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 Peo ria 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 i nclusion in a nonattainment area.

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 emitti ng 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 we re similar to

emissions in 2008. T herefore

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

emissions data ( NEI08V3 ).

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.11

Table 5 . SO 2 Emission s in the Pekin Area ( NEI08 V3 )

County Facility Located

in State

Recommended

Nonattainment

Area ? Facility

– Total SO 2 Air

Emissions NEI08 V3 (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 14,603

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 34,358

Yes Aventine Renewable

Energy

– 11,830 tpy 40.5553,

- 89.6629 1

*This source is included in the nonattainment area that EPA is promulgating

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

d id 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 i mpact on recorded concentrations at the

monitor. Th is source is located in Hollis Township, and so this township warrants consideration

for its contributions to t he violation measured in Pekin. Based on their distance from the violating monitor, EPA is n ot yet prepared to conclude that the other sources in Peoria County

contribute to the violating monitor ’s design value

. These sources will be further addressed in a subsequent round of designations.

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 red uctions resulting from controls put into place after 2008.

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. Figure 4 shows the prevalent wind direction for the Lemont, IL area.12

Figure 4 : Wind Rose f

or Pekin , IL

Source: IEPA Software: WRPLOT

- Lakes Environmental Software

The wind rose above suggests that winds come most frequently from the south, somewhat frequently from the northwest, and occasionally from the other directions. F ocusing on days

when concentrations are above the level of the standard, winds from the north (including variable winds that at least in part include north winds) occur with sufficient frequency to suggest that nearby significant sources located north as well as west and southwest of the monitor are contributing to violations measured in Pekin

. As discussed in more detail in the response to comments document, winds from the north (including variable winds that at least in part include north winds) also occur in particular at times when the standard is exceeded at the Pekin monitor.

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

The Pekin area does not have any geographical or topogra phical 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 under the prior SO2 NAAQS

. 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 establish ing a nonattainment area boundary for this area.13

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

. However, EPA has determined that the initial

nonattainment area should also include Hollis Township in Peoria County , which includes

Ameren’s E.D. Edwards Station. This sou rce has substantial emissions relatively close to the monitor measuring a violation , and analysis of wind information supports a finding of contribution of emissions from the direction of this source to the violating monitor . Therefore,

EPA believes that Hollis Township of Peoria County warrants inclusion in the initial Pekin

nonattainment area. Thus, a fter considering the factors described above, EPA is initially designat ing an area that includes Cincinnati and Pekin Township s in Tazewell County and Holl is Township in Peoria County as the Pekin , IL nonattainment area for the 2010 SO 2 NAAQS

. In a subsequent round of designations, we will make final designations decisions for areas and

sources that we are not yet prepared to conclude are contributing to th e monitored violations or to other possible violations and that are not currently included in the initial nonattainment area designation addressed in this TSD.