1 Draft Technical Support Document

Michigan

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

.

Michigan submitted recommendations on June 1, 2011

. Table 1 below lists Michigan’s

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

.

Table 1

. Nonat tainment Area Designation s for Michigan

Area Michigan ’s Recommended Designations of

Areas/Counties EPA's Intended Designation of

Areas/Counties

Detroit , MI
Wayne County ( part ial )

- A n area bounded on the east by the Michigan

- Ontario border, on the south by the Wayne County

- Monroe County border, on the west by Interstate 75 north to Southfield 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 borde r 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) w hich 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 susceptible to the health effects associated with breathing 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. Accordingly, EPA is not designating areas in this process on the basis of either of these two primary standards. Simil arly, 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 revised 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 promulga ting an initial area designation that is a

modification of a state’s recommendation

. EPA was to promulgate initial area designations within two years of promulgation of the revised primary standard, although EPA has extended

this deadline for one addition al year due to having insufficient information to promulgate the designations. If a state did not submit designation recommendations, EPA will promulgate the designations that it deems appropriate

. If a state or tribe disagrees with EPA’s intended design ations, they have 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, to Air Division Directors, U.S. EPA Regions I

- X. This memorandum identifies factors EPA in tends to evaluate in determining boundaries for areas designated nonattainment. These five factors include: 1) air quality data; 2) emissions and emissions

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

- existing nonattainment areas, reservations, metropolitan planning organiza tion) , 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 prov ided by the state or tribe 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 differing boundary than that of a default 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 Michigan 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 an d/ or on the technical analysis included 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 siting 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 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

.

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 cou nties 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.4

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

nonattain ment 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. Bas ed on this 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 an d 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 their recommended nonattainment area should be considered to be bounded by Mich igan 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 agrees with and intends to designate a Detroit , MI nonattainment area for the 2 010 SO 2 NAAQS with the boundaries recommended by Michigan.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 Detroit area based on data for the 200 8

- 20 10 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,

200 8

- 20 10 ( 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 2008

- 2010 design value in the county.

The Southwest High School monitor in Wayne 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 data

.

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 (NEI08V 2 )

.

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 i nformation 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 (NEI08V 2 )

County Facility in

State

Recommen

ded N.A.

Area ? Facility Emissions

NEI08V 2 (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 55,791

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 54 135,800

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 64,389

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. While three sources in Wayne County emitting over 100 tons per year are located outside the recommended nonattainment area, these are relatively smaller sources located at sufficient

distance from the vio lating monitor to be judged unlikely to have significant impacts at the

monitor.

Monroe County has a power plant with by far the most emissions of any facility in the area. This facility is also located at a substantial distance from the violating monitor. Using emissions divided by distance as a rough indicator of impacts, this facility is likely to have less impact than DTE’s River Rouge plant and USS’ Great Lakes Works but more impact than other sources in
the area. Thus, ful l 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 unlikely to have a significant impact on concentrations at the violating monitor.

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

emissions data submitted into EPA Clean Air Markets data base for the Monroe power plant.7

These data show that this facility installed 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 fac ility were similar to its emissions in 2010. Given this decline in emissions, the Monroe plant is likely to have significantly less impact than sources in Wayne County that are much closer to the violating monitor, so that the plant may reasonably be judg ed not to be a significant nearby contributor to the violations.

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 area. Fo r this area, wind patterns can be from any direction. Therefore, for a one

- hour standard, it is useful to consider all directions to have potential contribution. Nevertheless, winds in this area come from the southwest more frequently than from other qua drants, so sources to the south and west of the Southwest High

School monitor are most likely to contribute to violations at this monitor.

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

Michigan does not have any current SO 2 nonattainment areas

. Nonattainment areas in Michigan 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 area s.

Other Relevant Information

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

.

Conclusion

The nonattainment area recommended by Michigan includes the sources that are likely to be

contribu ting to the violation at the Southwest High School monitor. While a very 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 d istance from the

violation monitor to warrant its exclusion from the nonattainment area. Other sources outside Michigan’s recommended nonattainment area are also likely not to be having a significant impact on SO 2 concentrations at the violating monitor. Therefore

, EPA intends to designate a

Detroit , MI nonattainment area using the boundaries recommended by Michigan.