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

Michigan 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 Michigan that EPA intends to d esignate “nonattainment” for the primary 2010

SO 2 NAAQS.

Michigan submitted designation recommendations on June 1, 2011. On February 6, 2013, EPA sent a letter with intended designations for Michigan. Michigan did not respond to EPA’s intended designati on. Table 1 below lists Michigan’s recommendations and identifies the counties or portions of counties in Michigan for areas that EPA is initially designat ing

“nonattainment” based on monitored violations

. EPA is not yet prepared to designate other areas in Indiana, and will address such areas and their sources in a subsequent round of final designations.

Table 1. Nonattainment Area Designations for Michigan

Area Michigan ’s Recommended Designations of Ar eas/Counties EPA's Designation of

Areas/Counties

Detroit , MI
Wayne County (part ial )

- A n area bounded on the east by t he Michigan

- Ontario border, on the south by the Wayne County

- Monroe C ounty border, on the west by I nterstate
75 north to S outhfield Road,

Southfield Road to Interstate 94, and Interstate 94 north to Michigan Avenue, and on the north by Michigan Avenue to

Woodward Avenue and a line

on Woodward Avenue extended to the Michigan

- Ontario border 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 average concentration at each monitor in an area does not exceed 75 ppb

, as determined in accordance with Appendix T of 40 CFR part 50. 4 0 CFR 50.17(a)

- (b). 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 susceptible to the health effects associated 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 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 p rocess 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 a rea 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 i n 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 CFR 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 designation s, it had an opportunity to demonstrate why any proposed modification is inappropriate.

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

- X. This memorandum identifies 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 dat a (location of sources and potential

contribution to ambient SO 2 concentrations); 3) Meteorology (weather/transport patterns); 4) Geography/topography (mountain ranges or other air basin boundaries); and 5) Jurisdictional boundaries (e.g., counties, air di stricts, pre

- existing nonattainment areas, reservations, metropolitan planning organization), among any other information deemed relevant to establishing appropriate 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 potentia l 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 boundary.

In this TSD, EPA discusses its review and technical analysis of the recomm endations submitted by Michigan for designations of the 1

- 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 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 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 a nnual 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 Detroit , MI Area

Introduction

Th is technical analysis for the Detroit , MI area identifies Wayne C ount y 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

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

.4

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 at Southwest High School in Detroit recorded a 2009 to 2011 des ign value of 9 0 ppb. One other monitor operates in the area, at Allen Park, also in Wayne County, about 12 kilometers to the

s outhwest. T he Al len Park monitor recorded a 2009 to 2011 design value of 49 ppb.

Figure 1. Map of sources and monitors in the Detroit , MI area and the Detroit nonattainment area

Michigan analyzed the sources that might be c ontributing to the violation at Southwest High

School. T his assessment identified a series of major sources located south of downtown Detroit

and within a few kilometers of the Detroit River. Based on thi s assessment

, Michigan ’s June 1,

2011

, submittal recommended designating a nonattainment area bordered by the Michigan

Ontario border (in the Detroit River ) on the east, the Wayne

- Monroe county border on the south, Interstate 75, Southfield Road and Interstate 94 on the west, and Michigan Avenue on the north. Since Michigan Avenue does not extend fully to the Michigan

- Ontario border , Michigan subsequently clarified that its recommended nonattainment area should be c onsidered to be bounded by Michigan Avenue from Interstate 94 to Woodward Avenue and by Woodward Avenue and an extending line as if Woodward Avenue extended to the Michigan

- Ontario border. Michigan’s recommended nonattainment area averages approximately 6 kilometers east

- west
and about 40 kilometers north

- south.

Based on EPA's technical analysis described below, EPA is initially designat ing a Detroit , MI

nonattainment area for the 2 010 SO 2 NAAQS with the boundaries recommended by Michigan. Areas and sources that we are not yet prepared to conclude are contributing to the monitored5

violations or to possible other violations are not included in this initial nonattainment area , and will be addressed in a subsequent round of designations

.

Det ailed 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 Detroit area based on data for the 2009

- 2011 period

.

The 2010 SO 2 NAAQS design values for the Detroit , MI area in Michigan are shown in Table 2

.

Table 2 . Air Quality Data in the Detroit Area

County State Recommended

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

2009

- 2011 (ppb) Wayne Yes 26

- 163

- 0015 42.3028,

- 83.1065 90

Included in area 26

- 163

- 0001 42.2286,

- 83.2082 49

Monitor in Bold has the highest 2009

- 2011 design value in the county.

The Southwest High School monitor ( Monitor Air Quality System ID 26

- 163

- 0015 ) in Wayne County show s a violation of the 75 ppb 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. Michigan provided emissions data for 2009 generally showing emissions similar to 2008

emissions. T herefore

, EPA primarily 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 major sources in Wayne County and for sources emitting over 1000 tons per year in adjoining Monroe and St. Clair

Counties . 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 Detroit Area ( NEI08 V3 )

County Facility in

State

Recommen

ded N.A.

Area ? Facility Emissions

NEI08 V3 (tons per year) Facility Location Distance

to SWHS

mon itor (km) Total County

SO 2 Emissions (tons per year)

Wayne Yes DTE Trenton

Channel 27,622 42.1237,

- 83.1812 21 55,660

Yes DTE River Rouge 14,491 42.2727,

- 83.1124 3

Yes USS Great Lakes 6,755 42.2817,

- 83.1102 2

Yes Wyandotte Muni 1,793 42.2082,

- 83.1456 11

No GM Hamtramck 566 42.3820,

- 83.0449 10

Yes Severstal 558 42.3032,

- 83.1655 5

Yes Dearborn Industrial

Generation 401 42.3026,

- 83.154 4

Yes Carmeuse

Lime/River Rough 395 42.2774,

- 83.128 3

No Detroit W TP 225 42.2217,

- 83.3622 23

No Detroit Resource

Recovery 200 42.3686,

- 83.0517 7

Monroe No DTE Monroe 118,382 41.8917,

- 83.3461 54 135,789

No J.R. Whiting 9,260 41.7917,

- 83.4486 63

No Holcim Cement 7265 41.9933,

- 83.6596 57

St. Clair No Belle River power plant 62,114 42.7748,

- 82.4945 73 64,392

No E.B. Eddy Paper 1

, 019 42.9865,

- 82.4415 93

All of the largest sources in Wayne County are located within the recommended nonattainment

area. T hree sources in Wayne County emitting over 100 tons per year are located outside the

recommended nonattainment area . Based on the emissions from these relatively smaller sources

and their distance from the violating monitor

, EPA is not yet prepared to conclude that the

emissions from these three sources contribute to the monitored violation or to other possible

violations

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

Monroe County has a power plant with by far the most emissions of any facility in the area based

on the NEI08V3 . This facility is also located at a substantial distance from the violating monitor. Using emissions divided by distance as a rough indicator of impa cts, this facility is likely to have less impact than DTE’s River Rouge plant and USS’ Great Lakes Works but more impact on the violating monitor’s design value than other sources in the area. Thus, full consideration of the impact of this plant requires consideration of recent emission controls at this plant. The other plant in Monroe County and the plant in St. Clair County are at even greater distances and are

less likely to be contributing to the violating monitor ’s design value

.

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. Michigan did not provide any additional information on7

emissions reductions resulting from controls put into place after 2008. However, EPA examined

emissions data submitted into EPA ’s Clean Air Markets database for the Monroe power plant. These data show that this facility installe d wet limestone scrubbing systems on two of its four units in 2009, reducing SO 2 emissions from the 2008 level of 118,382 tons to a 2010 level of
47,608 tons. Emissions in 2011 from this facility were similar to its emissions in 2010. Given

this decline in emissions, and the distance of the facility from the monitor, the Monroe plant is likely to have significantly less impact on the monitor’s design value than sources in Wayne County that are much closer to the violating monitor

.

Based on information above for the sources in Monroe County and St. Clair County, we are not yet prepared to conclude that the emissions from these sources contribute to the monitored

violation or that the sources may be considered nearby

. We will further address these sourc es in a subsequent round of designations.

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 approp riate contributing areas and the appropriate extent of the nonattainment area. Figure 2 shows the prevalent wind direction for the Detroit area.

Figure 2: Wind Rose for Detroit, MI

Source: MDEQ Software: WRPLOT

- Lakes Environmental Software

The wind rose above shows that winds are most likely to come from the southwest but also frequently come from all the western directions, and occasionally from the other directions. This shows that a source from any direction could contribute to the violation at the monitor. All of the largest emitters in the area , including DTE Trenton Channel, DTE River Rouge, and USS8

Great Lakes, are located to the south and southwest of the mo nitor, which are the most frequent

wind directions.

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

The Detroit 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

Once the geographic area associated with the area violating the SO 2 standard and the nearby areas contributing to the monitored violations are determined, we consider ed existing jurisdictional boundaries for the purpose of providing a clearly defined legal boundary for carrying out the air qual it y planning and enforcement functions for the area. Michigan does not have any pre

- existing SO 2 nonattainment area boundaries under the prior NAAQS

. Nonattainment areas in Michigan for other pollutants have often been defined on the basis of roadways, and roadways in Michigan have well established locations and are a suitable basis for defining nonattainment areas. Therefore, EPA used roadways in defining the nonattainment boundary for the Detroit area. The boundary for the Detroit nonattainment area is provided in

Table 1 above.

Other Relevant Information

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

.

Conclusion

The air quality monitor located at Southwest High School shows a violation of the 2010 SO 2 NAAQS, based on 2009

- 2011 air quality data. The nonattainm ent area recommended by Michigan includes the violating monitor and sources that are likely to be contributing to the

violati ng monitor’s design value

. While a large source is located in Monroe County south of the recommended nonattainment area, this source has recently installed significant emission controls, and the source is sufficient ly distan t from the violati ng monitor to warrant not including

it in the in itial nonattainment area based on the monitored violation, as we are not yet prepared to

conclude that it is a nearby source contributing to that violation. This source will be further addressed in a subsequent round of designations.

Other sources outsid e Michigan’s recommended nonattainment area are also less likely to be having a significant impact on the violating monitor ’s design value, and we are similarly not yet prepared to conclude that these sources are contributing to the monitored violation

. W e will also further address these sources in a subsequent round of designations. Therefore

, EPA is initially designat ing a Detroit , MI nonattainment area using the boundaries recommended by Michigan. In a subsequent round of designations, we will make fin al designation decisions for areas in Michigan not included in the nonattainment area designation addressed in this TSD.