THE ADMINISTRATOR OF THE ENVIRONMENTAL PROTECTION AGENCY 

Mr. James R. Gray 

General Manager 

Great Lakes Works 

United States Steel Corporation 

1 Quality Drive 

Ecorse, Michigan 48229 

Dear Mr. Gray: 

WASHINGTON, D.C. 20460 

MAR 1 1 2014 

In an October 2, 2013, letter you filed a petition for reconsideration on behalf of the United States Steel 

Corporation concerning the U.S. Environmental Protection Agency's final rule, "Air Quality 

Designations for the 2010 Sulfur Dioxide Primary National Ambient Air Quality Standard." See 78 FR 

4719, August 5, 2013. The petition requests that the EPA reconsider the S02 nonattainment designation 

for the Detroit area and revise the boundaries of the nonattainment area to include the portion of Monroe 

County, Michigan, that contains DTE Energy Company's coal-fired power plant. In addition, the 

petition asks the EPA to stay the effect of the nonattainment designation of the Detroit area pending 

reconsideration. 

The EPA has carefully evaluated the issues and information in your petition. For the reasons explained 

in the EPA's initial final designation action and in the enclosure, I am denying the United States Steel 

Corporation's petition. Consequently, I also deny the United States Steel Corporation's request for a stay 

of the effectiveness of the August 5, 2013, designation. The EPA continues to believe that the state of 

Michigan recommended appropriate boundaries for the initial Detroit S02 nonattainment area. We plan 

to publish notice of this denial in the Federal Register, describing the option available to the United 

States Steel Corporation, if it chooses to petition for judicial review of this denial of the petition. 

I appreciate the United States Steel Corporation's interest in reducing S02 levels and in providing 

cleaner, healthier air for Michigan's residents and visitors. Please know that we look forward to working 

with you and the state of Michigan to ensure the Detroit area achieves the 2010 S02 standard. 

Gina McCarthy 

Enclosure 

cc: Mr. G. Vinson Hellwig, Chief, Air Quality Division 

Michigan Department of Environmental Quality 

This paper is printed with vegetable-oil-based inks and is 1 00-percent postconsumer recycled material, chlorine-free-processed and recyclable . 
Enclosure 

The EPA Response to the Petition for Reconsideration and Request for Stay from James R. Gray, 

General Manager, U.S. Steel Corporation- Great Lakes Works 

By letter dated October 2, 2013, U.S. Steel Corporation petitioned the U.S Environmental 

Protection Agency to reconsider and stay, pending reconsideration, the initial final area designation for 

the Detroit, Michigan area under the 2010 Sulfur Dioxide (S02) primary National Ambient Air Quality 

Standard (2010 S02 NAAQS). For the reasons discussed below, the EPA is denying this petition. The 

initial final designation was signed by the Administrator on July 25, 2013, and published in the Federal 

Register on August 5, 2013, at 78 FR 47191 (S02 designations). The S02 designations became effective 

on October 4, 2013. The EPA has reviewed the petition and revisited both the administrative record and 

the Administrator's decision process underlying the S02 designations in light of this petition. Our 

analysis of the petition leads us to conclude that the petition does not meet the criteria for 

reconsideration under the Clean Air Act (CAA). 

I. Summary 

The Petitioner seeks reconsideration of the S02 nonattainment area boundaries for the Detroit 

area designated by the EPA, to expand the area to include the DTE Energy Company's (DTE's) coalfired power plant located in Monroe County, Michigan (the Monroe Plant). The Petitioner believes 

reconsideration is warranted in part by new information provided by the Petitioner that it believes shows 

that the Monroe Plant's S02 emissions contributed to the 2010 S02 NAAQS violations recorded at the 

Southwestern High School (SWHS) monitor located 31 miles from the Monroe Plant. The Petitioner 

claims that this new information compels extending the boundary of the Detroit nonattainment area to 

include the Monroe Plant. The Petitioner argues that the grounds for its petition arise from such new 

information, including information that was not available during the public comment period, and that it 

would have been impractical for them to obtain it during the comment period. The Petitioner further 

asserts that the issues it raises in its petition are of "central relevance" to the outcome of the S02 

designations, and that its petition is timely filed. Finally, the Petitioner asks the EPA to stay the 

effectiveness of the S02 designations, pending the Agency's reconsideration. 

As discussed below, after careful review, we conclude the Petitioner's claims and the 

information it submits do not change our conclusions regarding the areas the EPA initially identified as 

violating the 2010 S02 NAAQS or as contributing to violations in nearby areas, as determined under 

section 107 of the CAA. 

The EPA has not made any decision whether violations are occurring near the Monroe Plant or 

elsewhere in Monroe County, and the Petitioner does not challenge the absence of such decision 

regarding violations in Monroe County independent of the violations in Wayne County; the Petitioner 

instead is only challenging the boundaries of the designated Detroit nonattainment area. Also, the 

evidence provided by the Petitioner is incomplete in important respects, and this incomplete 

information, to the extent it speaks to relevant questions, tends to support the EPA's findings regarding 

the appropriate extent of the initial Detroit nonattainment area. It does not justify modifying the 

boundaries of that area at this time. Therefore, the EPA declines reconsideration of its initial S02 

designation to grant the relief the Petitioner requests. 
In addition, because the EPA believes that the boundaries of the Detroit S02 nonattainment area 

do not presently warrant reconsideration, the EPA denies the Petitioner's request for a stay. 

II. Background 

A. Revisions to the S02 Primary NAAQS. 

Based on its review of the impact on air quality from oxides of sulfur, and the primary NAAQS 

for oxides of sulfur as measured by S02, the EPA published a revised primary S02 NAAQS on June 22, 

2010. See 75 FR 35520-35603. Specifically, the EPA replaced the prior 24-hour and annual standards 

with a new short-term standard of 75 parts per billion (ppb), evaluated on the basis of the 99th percentile 

among daily maximum 1-hour average values. The EPA also established requirements for an S02 

monitoring network and provisions specifying how the standard is shown to be met. These new 

provisions require monitoring in areas where there is an increased coincidence of population and S02 

emissions. The EPA did not, however, promulgate requirements governing designations of areas as 

either nonattainrnent, attainment or unclassifiable with respect to the new NAAQS under CAA section 

1 07, or governing development and approval of state implementation plans (SIPs) under CAA sections 

110, 172 and 191-192. 

B. The 2013 Designations of Initial Areas as Nonattainment Based on Monitored Violations of 

theNAAQS 

Following promulgation of the 2010 S02 NAAQS, under CAA section 107(d)(1)(A) state 

governors had until June 3, 2011 , to submit to the EPA recommendations for air quality designations, as 

either nonattainment, attainment or unclassifiable. Section 107(d)(1)(A) provides further that when the 

EPA intends to modify any state designation recommendations, it must provide states at least 120 days 

notice prior to promulgating final designations. During that period, states may demonstrate why they 

believe the EPA's proposed modifications are inappropriate. 

Nearly all states submitted timely designation recommendations to the EPA. On February 7, 

2013, the EPA provided the required 120 days notice of proposed modifications to states, and in such 

letters addressed areas for which states had already conducted 3 years of air quality monitoring of S02 

emissions that showed violations of the 2010 S02 NAAQS. The EPA expressed its intent not to modify 

the boundaries for the Detroit area that Michigan had recommended, but the EPA nevertheless wrote to 

Michigan to explain its rationale for intending to promulgate the Detroit nonattainment area designation 

that Michigan had recommended. The EPA did not address other types of areas in these letters, 

including areas for which there was not yet 3 years of monitoring showing a violation, even if there may 

have been modeling evaluating the impact of such areas' emissions. For those areas, instead, the EPA 

explained to the state governors that it was not yet prepared to propose designations. On February 15, 

2013, the EPA published a notice in the Federal Register providing the public an opportunity to 

comment on the EPA's intended designations of areas with monitored violations, and reiterated its 

position that it was at that time only prepared to propose designations for areas with monitored 

violations and for areas that were clearly contributing to such areas with monitored violations. 78 FR 

11124, 11126. The EPA stated that all other areas would be addressed in a future round of designations. 

!d. 

Regarding the proposed Detroit, Michigan nonattainment area, in its Draft Technical Support 

Document (TSD) for the proposed designations the EPA stated its agreement with the State of 

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Michigan's recommended boundaries for the area. Draft TSD, EPA-HQ-OAR-2012-0233-0177, at 4. 

While not proposing any final conclusions about the status of the area containing the Monroe Plant, the 

EPA suggested that given the Plant's distance from the monitor and recent installation of emissions 

controls and resulting declining 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 the plant may reasonably 

be judged to not be a significant nearby contributor to the violation." ld:.., at 7. The EPA then proposed to 

conclude that "the source is sufficient distance from the violation monitor to warrant exclusion from the 

nonattainment area." !d. 

U.S. Steel, among others, submitted timely comments on the EPA's proposed designations. 

EPA-HQ-OAR-2012-0233-0249 (U.S. Steel Comments). U.S. Steel objected to the EPA's intended 

designation of a Detroit area that did not include the Monroe Plant, and argued that additional 

information supported extending the Detroit nonattainment area to include the Monroe Plant, even in 

light of its distance from the violating monitor and the Monroe Plant's recently declining emissions. !d. 

In promulgating final designations for the addressed areas, the EPA more clearly explained that 

it was now only "initially" designating some areas as nonattainment, that for all other areas it was "not 

yet prepared" to issue designations, and that designation decisions would be reached for all areas not 

included in the initial round in separate future actions. 78 FRat 47193. In the Final TSD for Michigan, 

the EPA also more clearly stated that it was then taking final action only "for areas the EPA is initially 

designating 'nonattainment' based on monitored violations. [The] EPA is not yet prepared to designate 

other areas in [Michigan], and will address such areas and their sources in a subsequent round of final 

designations." EPA-HQ-OAR-2012-0233-0312 (Final TSD), at 1. The EPA further explained that 

" [b]ased on [the] EPA's technical analysis, [the] EPA is initially designating a Detroit, Michigan 

nonattainment area for the 2010 S02 NAAQS within the boundaries recommended by Michigan. Areas 

and sources that we are not yet prepared to conclude are contributing to the monitored violations or to 

possible other violations are not included in the initial nonattainment area, and will be addressed in a 

subsequent round of designations." Id. , at 4-5 (emphasis added). 

Regarding the Monroe Plant, the EPA also more clearly explained that "we are not yet prepared 

to conclude that the emissions from [the Monroe Plant] contribute to the monitored violation or that the 

source[] may be considered nearby. We will further address [the Monroe Plant] in a subsequent round of 

designations." Id:.., at 7 (emphasis added). In conclusion, the EPA stated that its initial assessment 

"warrant[ s] not including it in the initial 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.; !d., at 8 (emphasis added). 

In responding to U.S. Steel's comments on the proposed designations, the EPA, after discussing 

U.S. Steel's analysis in detail, found significant shortcomings in U.S. Steel's analysis, such as failure to 

consider the relationship between impacts of the Monroe Plant and impacts of other sources closer to the 

violating monitor. Furthermore, the EPA pointed out that "U.S. Steel conceded that Monroe Station 

would not be considered a source that is 'local"' to the violating monitor. Responses to Significant 

Comments on the State and Tribal Designation Recommendations for the 2010 S02 NAAQS, EPA-HQOAR-2012-0233-0354 [Response to Comments (RTC)], at 27. The EPA then stated that "[b]ased on the 

analysis described in the TSD, EPA continues to believe that Monroe Station is not a nearby source that 

contributes to the violation at the SWHS monitor." Id. , at 28. Furthermore, the EPA stated in the 

pertinent designation documentation that it was not yet prepared to base decisions regarding any areas 

3 
on submitted modeling information, and that it would determine how to consider such information in a 

subsequent round of designations. R TC at 6-9. 

As stated in the EPA's strategy paper for implementation ofthe S02 NAAQS (see 

http://epa.gov/airquality/sulfurdioxide/pdfs/20130207S02StrategyPaper.pdj), the EPA envisions 

directing states with areas with significant potential to violate the S02 NAAQS to obtain further 

information, either by monitoring or modeling, to inform future rounds of S02 designations. To the 

extent that further information becomes available regarding air quality impacts of the Monroe Plant as a 

result, such information may provide further insight both into whether a separate nonattainment area 

including the area of the Monroe Plant is warranted and into whether revisions to the Detroit 

nonattainment area are warranted. When the EPA designates the Monroe Plant's area, it will reach such 

a final conclusion. 

C. Petitions for Reconsideration and Stay and for Judicial Review 

Following promulgation of the initial S02 designations, in October 2013 numerous parties filed 

petitions for judicial review in the U.S. Court of Appeals for the D.C. Circuit, and one party filed a 

petition for review in the U.S. Court of Appeals for the 7th Circuit. Those cases have now all been 

consolidated in the D.C. Circuit. See Sierra Club, et al v. EPA, No. 13-1262 (and consolidated cases) 

(D.C. Cir.). One ofthe parties in the consolidated cases, U.S. Steel, also in October 2013 submitted to 

the EPA Administrator a petition for administrative reconsideration and stay of the rule under CAA 

section 307(d)(7)(B). 

U.S. Steel's petition for reconsideration objected to the EPA's fmal initial designation of the 

Detroit nonattainment area not including the Monroe Plant. U.S. Steel requested, first, that the EPA 

reconsider its initial designation of the boundary of the Detroit nonattainment area in light of new 

information that U.S. Steel argues demonstrates that the nearby Monroe Plant, located in an area for 

which EPA had not yet issued any designation, contributes to the monitored violations in Wayne 

County. In addition, U.S. Steel requested that the EPA administratively stay the final rule's effectiveness 

pending such reconsideration. Specifically, U.S. Steel objected to the EPA's establishment ofthe initial 

boundaries of the Detroit nonattainment area that did not include the area containing the Monroe Plant, 

and asserted that new computer modeling that was not yet available during the public comment period 

on the proposed designations shows that the Monroe Plant's area should be so included. 

II. Standards for Reconsideration 

Section 307(d)(7)(B) of the CAA, where applicable, strictly limits petitions for reconsideration 

both in time and scope. While this section does not apply here, insofar as designations are not one of the 

types of rulemaking listed in section 3 07 (d)( 1) as providing for petitions for reconsideration, the EPA is 

nevertheless using the section 307(d)(7)(B) criteria as the basis for evaluating U.S. Steel's petition, 

because there is no other section which directly applies to such petitions. 

Section 307(d)(7)(B) provides that judicial review of final actions taken under section 307(d) is 

generally only available with respect to issues raised "with reasonable specificity" during the comment 

period that the EPA has provided. An alternative in the form of a petition for reconsideration may be 

filed under strictly limited circumstances: "If the person raising an objection can demonstrate to the 

Administrator that it was impracticable to raise such objection within [the period for public comment] or 

if the grounds for such objection arose after the period for public comment (but within the time specified 

4 
for judicial review) and if such objection is of central relevance to the outcome of the rule, the 

Administrator shall convene a proceeding for reconsideration of the rule and provide the same 

procedural rights as would have been afforded had the information been available at the time the rule 

was proposed. If the Administrator refuses to convene such a proceeding, such person may seek review 

of such refusal in the United States court of appeals for the appropriate circuit (as provided in subsection 

(b)). Such reconsideration shall not postpone the effectiveness ofthe rule. The effectiveness of the rule 

may be stayed pending such reconsideration, however, by the Administrator or the court for a period not 

to exceed three months." 

U.S. Steel argues that the EPA must accept its petition because the petition is based on 

information, especially information based on modeling that was not available until after the EPA 

promulgated the pertinent S02 designations. However, U.S. Steel does not address whether the 

information provided in its petition for reconsideration could have been timely provided during the 

public comment period. That is, irrespective of when the modeling analysis was completed, U.S. Steel 

has not demonstrated that it was impracticable to have conducted the modeling analysis in a timely 

fashion and to have provided the resulting information during the EPA's public comment period or 

before. Indeed, the nonattainment area that EPA ultimately promulgated was the area that Michigan 

recommended on June 1, 2011 , which U.S. Steel had seen even before then, so that U.S. Steel had nearly 

2 years' opportunity to conduct this analysis and compile this information in advance of the close of the 

EPA's comment period on April8, 2013. The EPA believes that it was fully practicable for U.S. Steel to 

develop this information during this period, and U.S. Steel has not demonstrated otherwise. Therefore, 

the EPA believes that U.S. Steel's petition for reconsideration does not meet the section 307(d)(7) 

criteria for being granted, insofar as it was not impracticable for U.S. Steel to provide its comments in a 

timely fashion. 

The requirement to convene a proceeding under section 307(d)(7)(B) to reconsider a rule is 

based on the petitioner demonstrating to the EPA that the objection is of central relevance to the 

outcome of the rule. In the EPA's view, an objection is of central relevance to the outcome of the rule 

only if it provides substantial support for the argument that the promulgated regulation should be 

revised. See, e.g. , EPA's Denial ofthe Petitions to Reconsider the Endangerment and Cause or 

Contribute Findings for Greenhouse Gases under Section 202 of the CAA, 75 FR 49556, 49561 (August 

13, 2010). Under section 307(d)(7)(B), the Administrator is required to reconsider a rule subject to 

section 307(d) only ifthe objection is "of central relevance to the outcome ofthe rule." It is not enough 

that the objection be of central relevance to the issues involved in the rulemaking. Instead, the objection 

has to be of central relevance "to the outcome of the rule" itself. Section 307(d)(7)(B) requires that the 

objection be central to the substantive final decision that is the outcome of the section 307(d) rulemaking 

and that is taking effect. 

An objection is considered of central relevance to the outcome of the rule only if it provides 

substantial support for the argument that the final promulgated regulation should be revised. This 

properly links the criteria to the promulgated outcome ofthe rulemaking, not just the issues addressed in 

the rulemaking which may or may not have influenced that final action taken by the EPA. It requires 

that the objection be of such substance and merit that it can be considered central to the final outcome of 

the rulemaking. This interpretation gives proper weight to the approach throughout sections 307(b) and 

(d) of the importance Congress attributed to preserving the finality of agency rulemaking decisions made 

under section 307(d), once they have in fact been made. 

5 
The EPA is denying U.S. Steel's petition because it fails to meet all ofthese criteria. As is 

discussed below, U.S. Steel provides information suggesting that the Monroe Plant on some occasions 

has an impact at the site in Detroit that monitored violations of the S02 NAAQS, a view that is also 

implied by the information presented in the EPA's TSD for its action. U.S. Steel does not address 

whether this impact can be expected to occur at times when the S02 NAAQS is being exceeded, but the 

impact on these occasions is likely even more modest. As noted above, U.S. Steel also apparently agrees 

that the Monroe Plant need not be considered a source that is nearby to the violations. That is, to the 

extent that U.S. Steel addresses the questions relevant to whether the Monroe Plant should be included 

in the Detroit nonattainment area, we conclude that U.S. Steel's information tends to support not 

including the Monroe Plant in the nonattainment area. In any case, U.S. Steel has not demonstrated that 

the EPA must now amend its initial designation to propose and take final action to include the Monroe 

Plant as a nearby contributor to the already identified violations occurring in Wayne County. 

The objections do not provide substantial support for a conclusion that the final designation 

identifying the Detroit area as a nonattainment area was incorrect and should be revised. As such, they 

do not meet the statutory criteria for administrative reconsideration under CAA section 307(d)(7)(B). In 

addition, the EPA has expressly stated that the initial absence of the Monroe Plant from the Detroit 

nonattainment area did not represent a final decision regarding the attainment status of the area 

surrounding this facility. As a result, there is no action regarding the attainment status ofthe area in 

Monroe County surrounding the Monroe Plant that is ripe either for judicial review or for administrative 

reconsideration. 

U.S. Steel also asked the EPA to administratively stay the final S02 designations during the 

period that EPA was evaluating the petition for consideration. Since we are today denying the petition 

for reconsideration, the request for a stay becomes moot. There is no longer a reason to consider a stay 

under either CAA section 307(d)(7)(B) or APA section 705. 

Even if the request for an administrative stay was not moot, a stay of the final designation for the 

Detroit area is not warranted. In response to the arguments raised by U.S. Steel: (1) the Petitioner has 

not made a necessary showing on the merits, for all of the reasons for which the EPA is denying the 

petition to reconsider, (2) the Petitioner's arguments concerning irreparable harm pertain to a speculative 

outcome of air quality planning by the State of Michigan (disregarding the impact of the Monroe Plant) 

that far from being allowed and encouraged by the designation is in fact an impermissible outcome, (3) 

the Petitioner's arguments do not consider the possibility of harm to other parties if a stay of the initial 

S02 designations were to be granted, 'and (4) granting a stay would be contrary to the public interest. 

III. Administrative Process Issues 

A. Summary ofthe Petitioner's Arguments 

U.S. Steel asserts that the EPA must conclude its analysis ofthe Monroe Plant and its as-yetundesignated area in order to properly establish the boundaries of the areas for which it did issue 

designations. U.S. Steel explains that following a nonattainment designation for an area, significant 

obligations befall the area's host state to develop a SIP to bring the area into attainment with the 

NAAQS no later than 5 years from the effective date of designation. This SIP must be submitted to the 

EPA for review and approval or disapproval within 18 months of designation, and must include an 

analysis of sources of emissions in such area. U.S. Steel argues that leaving any significant source out of 

the nonattainment area, if its emissions may contribute to the area's nonattainment status, will result in 

6 
the state developing a SIP that consequently overburdens sources included in the nonattainment area in 

order to compensate for contributions from sources not yet included in the nonattainment area. To 

remedy the risk ofthis result, U.S. Steel claims, the EPA must complete its analysis of whether the 

Monroe Plant contributes to ambient air quality at the violating SWHS monitor in W;:tyne County. 

U.S. Steel then argues that the new modeling it has provided to the EPA that was not available 

during the public comment period would enable the EPA to complete this analysis. Moreover, U.S. Steel 

asserts that, following its own submission of adverse comments on the proposal, it had no reason not to 

expect the EPA to complete its analysis of the Monroe Plant. Because the EPA did not complete such an 

analysis, and because U.S. Steel considers such an analysis to be central to answering the question 

whether the Monroe Plant is a nearby source that contributes to the Detroit nonattainment area, U.S. 

Steel believes its objection and provision of new modeling information is of central relevance to the 

limited nonattainment decision the EPA made for the Detroit area in the initial final S02 designations. 

B. Responses to the Petitioner's Arguments 

The central assumption of each of the Petitioner's objections is that the EPA's initial final S02 

designations took final action regarding the Monroe Plant and the area in which it is located, and that the 

treatment of the Monroe Plant and its area are of central relevance to the outcome of the final S02 

designations that the EPA promulgated. But the Petitioner's arguments overstate the significance of 

EPA's designation ofthe Detroit area or, more precisely, the absence of the Monroe Plant from the 

designated Detroit nonattainment area. The EPA's designation ofthe Detroit nonattainment area obliges 

Michigan to. develop a plan that provides for attainment in the area. Specifically, the S02 concentration 

at any point in this area includes impacts from sources outside the area as well as impacts from sources 

inside the area, and Michigan is obliged under the CAA to develop a plan that provides that the sum of 

these impacts does not violate the NAAQS. While in some cases these impacts may be analyzed 

explicitly through modeling the pertinent source and in other cases these impacts may be analyzed 

implicitly as part of a background concentration estimated with monitoring data, in all cases the impacts 

of sources outside as well as inside the nonattainment area must be accounted for. Therefore, Michigan's 

plan must account for all impacts from all sources that influence concentrations in the nonattainment 

area, including the impacts from sources that have not been identified as nearby contributors to the 

violations. If Michigan's future analysis, and the EPA's review thereof, shows that it is necessary and 

appropriate to include new requirements for the Monroe Plant in its SIP in order for the Detroit 

nonattainment area to timely attain the NAAQS, the absence ofthe EPA's having yet designated the 

Monroe Plant's area in no way suggests that the State may ignore the Monroe Plant's emissions and 

"overburden" the Wayne County sources, as the Petitioner fears. 

In fact, even if the EPA had taken final action to designate the Monroe Plant's area as something 

other than nonattainment, such that there could be an issue regarding whether the EPA's treatment of the 

Monroe Plant in the initial S02 designations Rule was of "central relevance" to the actually promulgated 

designations, Michigan would remain obliged to consider the impacts of sources outside the 

nonattainment boundary, such as the Monroe Plant, either by expressly modeling the impact or by 

considering the sources' impacts as part of background concentrations, and nothing would preclude 

Michigan from deciding to require emission reductions and taking account of required reductions at 

sources outside the nonattainment area, including the Monroe Plant, in a future SIP addressing the 

Detroit area. Also, if Michigan had instead recommended that the Monroe Plant be included in the 

nonattainment area and if the EPA had so included it, this result would not on its own have required 

Michigan to allocate the burdens across its sources for attaining the NAAQS any differently than 

7 
otherwise may be needed in order for the Detroit area to attain, whatever the Monroe Plant's area 

designation. 

The EPA has not yet taken a final action regarding the Monroe Plant that could be presently 

"reconsidered" under CAA section 307(d)(7)(B). Any interested party may raise its objections to how 

the EPA designates the Monroe Plant's area in the future action for that area, an action that will be based 

on a complete analysis of the Monroe Plant as a "final" matter for the first time. In response to U.S. 

Steel's immediate concern, as Michigan develops its SIP for the Detroit area, Michigan will need to 

account for all possibly contributing sources, and interested parties will be free to attempt to demonstrate 

in Michigan's public comment process why they believe any sources located outside the area may be 

inadequately addressed by Michigan for the area to attain the 2010 S02 NAAQS. The EPA will have to 

review and take final approval or disapproval action- also subject to public comment at the federal level 

--on Michigan's submitted attainment demonstration for whether it appropriately shows future timely 

attainment of the NAAQS. 

IV. Review of Petitioner's Substantive Arguments 

A. Summary of the Petitioner's Arguments 

The Petitioner's arguments address three main technical areas: (1) the EPA's analysis ofthe 

nonattainment area, (2) consistency between the EPA's treatment of the Detroit nonattainment area 

designation and other area designations and (3) modeling provided by the Petitioner. The Petitioner 

asserts that by focusing on Wayne County, the EPA did not do a full analysis ofthe initial Detroit 

nonattainment area. The Petitioner stated that the Monroe Power Plant in adjacent Monroe County is the 

largest source in the Detroit area and that by not including the source and Monroe County in the 

nonattainment area, the EPA causes a disproportionate obligation on the sources in the Detroit 

nonattainment area if a contributing source is located outside the initially designated nonattainment area. 

The Petitioner also states that the contribution to the violating monitor in Wayne County from the 

Monroe Power Plant is greater than the contribution from most of the sources in the Detroit 

nonattainment area, and that an indicator based on the ratio of emissions divided by distance suggests 

that it is the fourth largest contributor. The Petitioner alleges that the EPA's analysis is incomplete, even 

without considering the later submitted modeling, because the EPA did not consider local geography or 

meteorology for the area, in particular because the EPA did not consider the funneling effect of local 

water sources. 

The Petitioner provided several examples of designations with what it considered to be similar 

circumstances to support its claim that the EPA was not consistent between its treatment of the Detroit 

area and other areas included in the S02 designations and other designations actions. The frrst example 

is Indiana County, Pennsylvania, for the 2010 S02 standard. In this example, the EPA added the 

Keystone Power Plant to the state's recommended nonattainment area. The plant is 37.1 kilometers (km) 

from the violating monitor, and, like the Monroe Power Plant, had scrubbers installed in 2009. The 

Petitioner also provided examples from fme particulate matter (PM2.s) and ozone designations where 

power plants were added to the nonattainment areas recommended by states. 

Most of the Petitioner's argument relies upon dispersion modeling provided by the Petitioner to 

the EPA for the first time in this petition. This information was not made available to the EPA during the 

comment period. The Petitioner stated that it did not have time to complete it during the comment 

period, but did not give reasons why, nor did it request an extension to the comment period. The 

8 
Petitioner also did not offer any reasons that it could not have begun its modeling analysis earlier in the 

designations development process. 

The Petitioner provides results from use of two models: CALPUFF and AERMOD. According to 

the appendix to the petition, the preferred model, AERMOD, indicated that the maximum impact of the 

Monroe Plant at any time at the SWHS location was 11 ppb. The petition states that CALPUFF results 

indicated that the maximum impact of the Monroe Plant at the same location was 16 ppb. The petition 

did not present modeled results indicating the impacts of other plants at the same time, nor did the 

petition present any other modeling results to indicate what impacts the Monroe Plant is expected to 

have specifically during periods when the S02 NAAQS is being exceeded at the SWHS monitor or any 

other location. The appendix to the petition presented results comparing the frequency with which the 

impacts of the Monroe Plant exceeded the impacts ofDTE's Trenton Power Plant within the 

nonattainment area, but neither the petition nor its appendix addressed the relative impact of the Monroe 

Plant on the subset of circumstances in which concentrations at the Southwestern High School monitor 

exceeded the NAAQS or any other concentration criterion. 

The Petitioner claims to be harmed by the boundaries of the Detroit nonattainment area. In the 

Petitioner's view, the lack of inclusion of the Monroe Plant from the initial Detroit nonattainment area 

serves to instruct Michigan that its plan for attaining the S02 standard in the Detroit area is to focus 

more on reducing emissions from sources in Wayne County such as U.S. Steel's facility than on 

reducing emissions from the Monroe Plant, potentially even to the point that no credit might be taken for 

any emission reductions at the Monroe Plant and that the entire burden of attaining the S02 standard 

might fall on Wayne County sources. 

B. Responses to the Petitioner's Arguments 

The EPA conducted a five factor analysis for the Detroit nonattainment area. The EPA 

considered air quality data, emissions and emissions-related data, meteorology, geography/topology and 

jurisdictional boundaries. In this analysis, the EPA concluded that although winds are often from the 

south and southwest directions, the directions that would tend to bring emissions from the Monroe 

Power Plant to the location of the violating monitor, several other sources at a much closer distance in 

the south and southwest direction from the monitor are more likely to be causing more significant 

impacts at times when exceedances of the NAAQS are recorded by the monitor. In addition to distance 

ofthe source from the monitor, the EPA noted that the Monroe Power Plant had installed controls that 

reduced its annual S02 emissions from 135,789 tons per year (tpy) in 2008 to 47,608 tpy in 2010. With 

this large drop in emissions and the 50 km separating the power plant from the monitor, and the 

presence of a non-violating monitor closer to and in a similar direction from the Monroe Plant, the EPA 

was not prepared to conclude at the time the EPA promulgated its initial S02 nonattainment designations 

that this source had the kind of clear and significant impact on the recorded exceedances that was arising 

from several more nearby sources. Elevated concentrations of S02 predominantly occur within a few km 

of the point of their emissions, and many of the violations in the initial nonattainment areas for the 2010 

S02 NAAQS are predominantly caused by smaller nearby sources. The area in Detroit surrounding the 

SWHS monitor has several moderate and large nearby sources, including the DTE Trenton Channel 

plant with S02 emissions of27,622 tpy, the DTE River Rouge plant with 14,491 tpy, and U.S. Steel's 

Great Lakes facility with 6,755 tpy. 

U.S. Steel errs in assuming that the absence of the Monroe Plant from the Detroit nonattainment 

area will cause a disproportionate obligation on the sources included in the initial nonattainment area. 

9 
Michigan is obligated in its Detroit area attainment planning to consider all emissions that influence that 

area's S02 concentrations, including emissions from sources outside the designated nonattainment area. 

While Michigan has the option to address the impact of the Monroe Plant as an element of the 

background concentration as determined by use of monitoring data, the EPA has encouraged Michigan 

to address the Monroe Plant expressly in its modeling as a modeled source, and initial modeling runs by 

Michigan have in fact done so. The EPA understands that Michigan's initial runs suggest that modeled 

concentrations well above the NAAQS reflect impacts dominated by sources in Wayne County that are 

near the violating monitor, and that the impact of the Monroe Plant is sufficiently less such that 

Michigan, in conducting intermediate modeling runs focusing on the sources for which controls would 

most effectively address the Wayne County violations, may choose to exclude the Monroe Plant from 

these runs. That is, present evidence from Michigan's analyses to date suggests that even in accounting 

for the Monroe Plant's impacts, emissions from U.S. Steel's plant and from other more nearby plants 

will need to be the primary focus of Michigan's attainment planning. 

It is during a state's development of the attainment SIP that the state will determine the needed 

obligations of various sources in order to demonstrate future NAAQS attainment in the designated area. 

During that process, the state must account for impacts of sources outside of the initially identified 

boundaries of the nonattainment area to demonstrate attainment, and in that process the state will 

determine what mix of emission reductions constitutes the most appropriate means of providing for 

timely attainment. 

As the Petitioner is well aware, Michigan has taken significant steps toward evaluating which 

sources have the most significant impacts on violations in the Detroit area and toward evaluating the 

control measures that would be most effective at addressing the problem. The EPA understands that 

Michigan has already conducted several modeling runs to evaluate impacts of various sources in 

Southeast Michigan. Michigan has conducted initial modeling runs that included the Monroe Plant as an 

expressly modeled source. These initial runs preliminarily suggest that the impacts of the Monroe Plant 

on modeled violations are relatively minor, particularly in comparison to the impacts of U.S. Steel and 

other sources that are much closer to the violating monitor. Publicly available information on 

Michigan's continuing analyses is available at 

http://www.semcog.org/WorkArea/DownloadAsset.aspx?id=91300. While Michigan did not submit this 

modeling in support of its designation recommendations, and while the EPA did not consider any such 

modeling while developing its initial designation for the Detroit area, this modeling tends to suggest 

three possible conclusions may be reached in the future : (1) that the Monroe Plant need not be 

considered a nearby contributor to the violations at the SWHS monitor, (2) that the impact of the 

Monroe Plant is sufficiently minor at times of violations at the SWHS monitor that Michigan could 

reasonably focus its Detroit area SIP planning efforts on sources that are much closer to the monitor and 

(3) that the SIP process will provide ample opportunity for U.S. Steel to provide input on the degree to 

which the plan for providing for attainment in the Detroit area should include requirements for 

additional emission controls at the Monroe Plant beyond those already implemented in 2009. 

The Petitioner identified several designation examples that it argued show inconsistent treatment 

by the EPA between those examples and the Detroit nonattainment area. Many of the examples were for 

PM2.s NAAQS and ozone NAAQS designations. PM2.s and ozone are considered regional pollutants. 

The geographic scale of source-receptor relationships for regional pollutants is significantly different 

from that for more local pollutants such as S02, and the definition of "nearby" and the geographic size 

ofnonattainment areas differ accordingly. For PM2.s and ozone, significant impacts, sometimes 

constituting a majority of the observed concentrations, arise from the cumulative effects ofthe emissions 

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of precursors from sources located hundreds of miles away. In contrast, for S02, it is common for the 

majority of a monitored or modeled concentration to arise from a source or set of sources located within 

1 to 5 km of the violating location. As a result, the starting point for evaluating contributions to regional 

pollutant violations is Metropolitan Areas, generally consisting of several counties, whereas analyses for 

local pollutants like S02 typically address the county or even the sub-county level. Therefore, examples 

from PM2.s and ozone designations are not relevant here, and the consideration of whether the EPA 

promulgated a Detroit area S02 nonattainment area that was consistent with other comparable 

designations should be limited to consideration of other S02 designations. I 

A more germane comparison that the Petitioner provided addressed the 2013 S02 designation for 

the Indiana, Pennsylvania nonattainment area. The Petitioner believes that the Indiana, Pennsylvania 

area is comparable to the Detroit area because it contains a larger power plant located reasonably distant 

from the monitor that was included in the initial nonattainment area. However, the Indiana, 

Pennsylvania area differs from the Detroit area in significant respects. First, the violating monitor in the 

Detroit area is subject to significant impacts from six nearby sources (five being located between 2 and 5 

km from the violating monitor and one at 11 km) and a seventh larger source at a moderate distance of 

21 km from the monitor. Thus, in the Detroit area, the State ofMichigan and the EPA reasonably 

viewed the violations as affected most strongly by relatively nearby sources. In contrast, the closest 

source impacting the Indiana, Pennsylvania violating monitor is 20 km from the monitor. This area is 

not significantly impacted by any other, closer nearby sources. Therefore, the Keystone Power Plant, 

despite being 37 km from the monitor, appears to have a more significant influence on concentrations at 

the violating monitor relative to other sources in the area, because the Keystone Power Plant is both 

significantly larger than two of the three other sources impacting the monitor (29,420 tpy versus 4,333 

and 6,312 tpy) and not significantly more distant. Therefore, the Keystone Power Plant more clearly 

warrants being included in the initial nonattainment area than does the Monroe Plant, although in both 

areas, as previously explained, the sources will need to be explicitly considered in the states' respective 

planning processes. 

A more relevant comparison from the 2013 S02 designations is the designation for the Lemont, 

Illinois nonattainment area. In this area, the Midwest Generation Joliet Station and the Exxon Mobil 

facility (at 22 and 33 km from the violating monitor) were, like the Monroe Plant, not included in the 

initial npnattainment area and left for further future analysis due to the more significant impacts of 

closer nearby sources located less than 10 km from the violating monitor. Winds were equally prone to 

blow from the pertinent sources to the violating monitor in the Lemont area as in the Detroit area, but 

the EPA judged in both areas that the more distant sources did not warrant being considered as nearby 

contributing sources. Another relevant example from the 2013 S02 designations is for the Jackson 

County, Missouri area. For this area, the EPA determined the monitored S02 NAAQS violation to be 

caused predominantly by the Grand Avenue Power Plant located 5.1 km away. The source emitted 6,295 

tons of S02 in 2008. Also in a similar direction are two other power plants, the BPU-Quindaro facility 

and the BPU-Nearman facility emitting, respectively, 3,901 and 5,992 tons of S02 in 2008 at 7.9 and 

13.2 km from the violating monitor. However, based on wind analyses and, like in the Detroit area, the 

presence of a non-violating monitor at a closer proximity to those two sources, the EPA was not 

prepared at the time of the so2 designations to conclude that these two facilities contributed to the 

monitored violation, and left them for further future analysis. The EPA's approach in the Detroit area 

designation was consistent with these designations of other similar areas. 

1 Designations for other pollutants with relatively local impacts might also be suitable for comparison, but this point is moot 

because U.S. Steel presented no such comparisons. 

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The Petitioner also argued that modeling it submitted with its petition shows contribution to the 

Detroit nonattainment area from the Monroe Power Plant. The EPA does not believe it is currently 

appropriate to reconsider the Detroit area's designation based on this new modeling, for three principal 

reasons. First, as discussed above, the modeling provides inadequate information to evaluate whether the 

Monroe Plant contributes to the monitored violations, most notably insofar as the modeling does not 

address either the impacts of the Monroe Plant on occasions when concentrations exceeding the NAAQS 

are occurring or the impacts of the Monroe Plant in relation to the impacts of other sources that are more 

clearly influencing the monitored violations. Second, this modeling was not made available to the EPA 

at the time of proposing or finalizing the initial monitoring-based designations. The Petitioner did not 

conduct and submit this modeling during the public comment period and did not give any reason as to 

why it was not performed and made available at that time. If the length of the comment period was an 

impediment, the EPA was not made aware of this, as the Petitioner did not request to have the comment 

period further extended. Third, as the EPA repeatedly explained in its TSDs and RTC document 

regarding other areas for which modeling was submitted, the agency was not at the time of the S02 

designations prepared to base proposed or final designations under the 2010 S02 NAAQS on submitted 

modeling analyses, in part due to the fact that the EPA is continuing to refine its technical guidance on 

how such modeling should be conducted. Nevertheless, to the extent that the Petitioner's newly 

submitted modeling is germane to future designation actions, particularly any actions addressing the 

attainment status of the area in the immediate vicinity of the Monroe Power Plant, Michigan's and the 

EPA's deliberations on such actions would provide an appropriate opportunity for consideration of the 

new modeling information U.S. Steel has developed. 

In addition, the EPA notes two things: First, U.S. Steel in no way objects to the EPA's 

determination that the Detroit area is violating the S02 NAAQS and must therefore be designated 

nonattainment; second, the EPA has not yet taken any final action regarding the Monroe Plant and its 

impact on any area, designated or not designated. Thus, the Agency responds to several of U.S. Steel's 

arguments conditionally, leaving open the possibility that if the Petitioner were to raise these and other 

objections in the context of such future final designation action for the Monroe Plant's area, the EPA 

might reach final conclusions that differ from the responses provided here. 

V. Conclusion 

For all of the reasons discussed above, U.S. Steel's petition to reconsider the initial final area 

designation for the Detroit, Michigan area under the 2010 S02 NAAQS is denied, as is the petition for 

an administrative stay. 

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