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 behalfofthe 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 ofthe 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 ofthe nonattainment designation ofthe 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 ofthe effectiveness ofthe 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 ofthis 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 ofthe 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 ofMichigan to ensure the Detroit area achieves the 2010 S02 standard.

Gina McCarthy

Enclosure

cc : Mr. G

. Vinson Hellwig, Chief , Air Quality Division Michigan Department ofEnvironmental 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 S02NAAQS)

. 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 (S02designations). The S02designations 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 S02designations in light ofthis petition. Our analysis ofthe 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 ofthe S02nonattainment 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 Count y, 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 S02emissions contributed to the 2010 S02NAAQS 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 ofthe 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 ofthe S02 designations, and that its petition is timely filed. Finally, the Petitioner asks the EPA to stay the effectiveness ofthe 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 ofthe 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 ofthe violations in Wayne County; the Petitioner instead is only challenging the boundaries ofthe 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 ofthe initial Detroit nonattainment area. It does notjustify modifying the boundaries ofthat area at this time. Therefore, the EPA declines reconsideration ofits initial S02 designation to grant the reliefthe Petitioner requests.In addition, because the EPA believes that the boundaries ofthe 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 S02Primary NAAQS

. Based on its review ofthe 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 S02NAAQS 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 of75 parts per billion (ppb) , evaluated on the basis ofthe 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 ofpopulation 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 ofInitial Areas as Nonattainment Based on Monitored Violations of theNAAQS Following promulgation of the 2010 S02NAAQS , 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 ofproposed modifications to states, and in such letters addressed areas for which states had already conducted 3 years ofair quality monitoring of S02 emissions that showed violations of the 2010 S02NAAQS. 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 ofareas in these letters, including areas for which there was not yet 3 years ofmonitoring showing a violation, even ifthere 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 ofareas 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 ofdesignations. !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

2Michigan'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 ofthe area containing the Monroe Plant, the EPA suggested that given the Plant' s distance from the monitor and recent installation ofemissions 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 ofa 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 ofits 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 offinal 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 S02NAAQS 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 ofdesignations. " 

### 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 ofdesignations

.; 

### !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 ofthe Monroe Plant and impacts ofother 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 S02NAAQS , 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

3on submitted modeling information, and that it would determine how to consider such information in a subsequent round ofdesignations. RTC at 6-9

. As stated in the EPA ' s strategy paper for implementation ofthe S02NAAQS 

### (see http:// epa.gov /

airquality /

sulfurdioxide / pdfs /

2013020 7 S02StrategyPaper.pdj), the EPA envisions directing states with areas with significant potential to violate the S02NAAQS 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 ofthe Monroe Plant as a result, such information may provide further insight both into whether a separate nonattainment area including the area ofthe 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 ofAppeals for the D.C. Circuit, and one party filed a petition for review in the U.S

. Court ofAppeals 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 f or administrative reconsideration and stay ofthe rule under CAA section 307(d)(7)(B).
U.S. Steel ' s petition for reconsideration objected to the EPA' s fmal initial designation ofthe Detroit nonattainment area not including the Monroe Plant. U.S. Steel requested, first, that the EPA reconsider its initial designation ofthe boundary ofthe Detroit nonattainment area in light ofnew 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 ofthe 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 ) ofthe 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 ofthe types ofrulemaking listed in section 307(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 thatjudicial review offinal 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 ofa petition for reconsideration may be filed under strictly limited circumstances: " Ifthe person raising an objection can demonstrate to the Administrator that it was impracticable to raise such objection within [the period for public comment] or ifthe grounds for such objection arose after the period for public comment (but within the time specified
4for judicial review) and if such objection is ofcentral relevance to the outcome ofthe rule, the Administrator shall convene a proceeding for reconsideration ofthe rule and provide the same procedural rights as would have been afforded had the information been available at the time the rule was proposed

. Ifthe Administrator refuses to convene such a proceeding, such person may seek review of such refusal in the United States court ofappeals for the appropriate circuit (as provided in subsection (b))

. Such reconsideration shall not postpone the effectiveness ofthe rule

. The effectiveness ofthe 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 S02designations. 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 ofwhen 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 ofthe close ofthe 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 ofthe rule. In the EPA' s view, an objection is ofcentral relevance to the outcome ofthe rule only ifit 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 ofthe 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 " ofcentral relevance to the outcome ofthe rule. " It is not enough that the objection be ofcentral relevance to the issues involved in the rulemaking

. Instead, the objection has to be ofcentral relevance "to the outcome ofthe rule" itself. Section 307(d)(7)(B) requires that the objection be central to the substantive final decision that is the outcome ofthe section 307(d) rulemaking and that is taking ef fect.
An objection is considered ofcentral relevance to the outcome ofthe rule only ifit 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, notjust 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) ofthe importance Congress attributed to preserving the finality ofagency rulemaking decisions made under section 307(d), once they have in fact been made.

5The 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 ofthe S02NAAQS , 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 ofthe Monroe Plant from the Detroit nonattainment area did not represent a final decision regarding the attainment status ofthe 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 forjudicial 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 ifthe request for an administrative stay was not moot, a stay ofthe 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 ofthe 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 ofMichigan (disregarding the impact ofthe 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 ofharm to other parties ifa stay ofthe 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 ofthe 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 ofdesignation. This SIP must be submitted to the EPA for review and approval or disapproval within 18 months ofdesignation, and must include an analysis of sources ofemissions 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

6the 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 ofwhether 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 ofadverse comments on the proposal, it had no reason not to expect the EPA to complete its analysis ofthe 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 ofnew modeling information is ofcentral 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 ofeach ofthe 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 ofthe Monroe Plant and its area are of central relevance to the outcome ofthe 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 ofthe 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. IfMichigan' 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 ifthe 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 ofthe 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 ofbackground concentrations, and nothing would preclude Michigan from deciding to require emission reductions and taking account ofrequired reductions at sources outside the nonattainment area, including the Monroe Plant, in a future SIP addressing the Detroit area. Also, ifMichigan had instead recommended that the Monroe Plant be included in the nonattainment area and ifthe 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

7otherwise 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 ofthe 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 S02NAAQS

. 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 ofthe NAAQS.


### IV. Review ofPetitioner's Substantive Arguments
A. Summary ofthe 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 ofthe 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 ofthe sources in the Detroit nonattainment area, and that an indicator based on the ratio ofemissions 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 oflocal water sources
. The Petitioner provided several examples ofdesignations with what it considered to be similar circumstances to support its claim that the EPA was not consistent between its treatment ofthe 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 ofthe 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
8Petitioner 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 oftwo models: CALPUFF and AERMOD. According to the appendix to the petition, the preferred model, AERMOD , indicated that the maximum impact ofthe Monroe Plant at any time at the SWHS location was 11 ppb. The petition states that CALPUFF results indicated that the maximum impact ofthe Monroe Plant at the same location was 16 ppb

. The petition did not present modeled results indicating the impacts ofother 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 S02NAAQS 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 ofthe 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 ofthe Monroe Plant on the subset ofcircumstances 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 ofthe Detroit nonattainment area. In the Petitioner' s view, the lack ofinclusion ofthe 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 ofattaining 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 ofthe 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 ofthe 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 S02emissions 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 ofa 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 S02nonattainment designations that this source had the kind ofclear and significant impact on the recorded exceedances that was arising from several more nearby sources. Elevated concentrations of S02predominantly occur within a few 

### km ofthe point oftheir emissions, and many ofthe violations in the initial nonattainment areas for the 2010 S02NAAQS 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 S02emissions 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 ofthe Monroe Plant from the Detroit nonattainment area will cause a disproportionate obligation on the sources included in the initial nonattainment area.
9Michigan 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 ofthe Monroe Plant as an element ofthe background concentration as determined by use ofmonitoring 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 ofthe 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 ofthe attainment SIP that the state will determine the needed obligations ofvarious sources in order to demonstrate future NAAQS attainment in the designated area. During that process , the state must account for impacts of sources outside ofthe initially identified boundaries ofthe nonattainment area to demonstrate attainment, and in that process the state will determine what mix ofemission reductions constitutes the most appropriate means ofproviding 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 ofvarious 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 ofthe Monroe Plant
on modeled violations are relatively minor, particularly in comparison to the impacts ofU.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.or g

/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 ofthe Monroe Plant is sufficiently minor at times ofviolations 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 ofthe 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 ofthe observed concentrations, arise from the cumulative effects ofthe emissions

10ofprecursors from sources located hundreds ofmiles 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 ofthe 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 S02typically address the county or even the sub-county level. Therefore, examples from PM2

.s and ozone designations are not relevant here, and the consideration ofwhether the EPA promulgated a Detroit area S02 nonattainment area that was consistent with other comparable designations should be limited to consideration ofother 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 ofthe 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 EPAjudged 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 S02NAAQS violation to be caused predominantly by the Grand Avenue Power Plant located 5.1 km away
. The source emitted 6,295 tons of S02in 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 ofa non-violating monitor at a closer proximity to those two sources, the EPA was not prepared at the time ofthe 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 ofother 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. 11The 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 ofthe Monroe Plant on occasions when concentrations exceeding the NAAQS are occurring or the impacts ofthe Monroe Plant in relation to the impacts ofother sources that are more clearly influencing the monitored violations

. Second, this modeling was not made available to the EPA at the time ofproposing 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

. Ifthe length ofthe comment period was an impediment, the EPA was not made aware ofthis, 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 ofthe S02 designations prepared to base proposed or final designations under the 2010 S02NAAQS 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 ofthe area in the immediate vicinity ofthe Monroe Power Plant, Michigan' s and the EPA' s deliberations on such actions would provide an appropriate opportunity for consideration ofthe 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 S02NAAQS 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 ofU.S. Steel ' s arguments conditionally, leaving open the possibility that ifthe 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 S02NAAQS is denied, as is the petition for an administrative stay

.

12