Federal Register / Vol. 86, No. 39 / Tuesday, March 2, 2021 / Rules and Regulations 12095 

Order 13132 (64 FR 43255, August 10, 

1999); 

• Is not an economically significant 

regulatory action based on health or 

safety risks subject to Executive Order 

13045 (62 FR 19885, April 23, 1997); 

• Is not a significant regulatory action 

subject to Executive Order 13211 (66 FR 

28355, May 22, 2001); 

• Is not subject to requirements of 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (15 U.S.C. 272 note) because 

application of those requirements would 

be inconsistent with the CAA; and 

• Does not provide EPA with the 

discretionary authority to address, as 

appropriate, disproportionate human 

health or environmental effects, using 

practicable and legally permissible 

methods, under Executive Order 12898 

(59 FR 7629, February 16, 1994). 

In addition, the SIP is not approved 

to apply on any Indian reservation land 

or in any other area where EPA or an 

Indian tribe has demonstrated that a 

tribe has jurisdiction. In those areas of 

Indian country, the rule does not have 

tribal implications and will not impose 

substantial direct costs on tribal 

governments or preempt tribal law as 

specified by Executive Order 13175 (65 

FR 67249, November 9, 2000). 

The Congressional Review Act, 5 

U.S.C. 801 et seq., as added by the Small 

Business Regulatory Enforcement 

Fairness Act of 1996, generally provides 

that before a rule may take effect, the 

agency promulgating the rule must 

submit a rule report, which includes a 

copy of the rule, to each House of the 

Congress and to the Comptroller General 

of the United States. EPA will submit a 

report containing this action and other 

required information to the U.S. Senate, 

the U.S. House of Representatives, and 

the Comptroller General of the United 

States prior to publication of the rule in 

the Federal Register. A major rule 

cannot take effect until 60 days after it 

is published in the Federal Register. 

This action is not a ‘‘major rule’’ as 

defined by 5 U.S.C. 804(2). 

Under section 307(b)(1) of the CAA, 

petitions for judicial review of this 

action must be filed in the United States 

Court of Appeals for the appropriate 

circuit by May 3, 2021. Filing a petition 

for reconsideration by the Administrator 

of this final rule does not affect the 

finality of this action for the purposes of 

judicial review nor does it extend the 

time within which a petition for judicial 

review may be filed, and shall not 

postpone the effectiveness of such rule 

or action. This action may not be 

challenged later in proceedings to 

enforce its requirements. See section 

307(b)(2). 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Incorporation by 

reference, Intergovernmental relations, 

Nitrogen dioxide, Ozone, Particulate 

matter, Reporting and recordkeeping 

requirements, Sulfur oxides. 

Dated: February 23, 2021. 

John Blevins, 

Acting Regional Administrator, Region 4. 

For the reasons stated in the 

preamble, the EPA amends 40 CFR part 

52 as follows: 

PART 52—APPROVAL AND 

PROMULGATION OF 

IMPLEMENTATION PLANS 

■ 1. The authority citation for part 52 

continues to read as follows: 

Authority: 42 U.S.C. 7401 et seq. 

Subpart RR—Tennessee 

§ 52.2219 [Amended] 

■ 2. Amend § 52.2219 by removing and 

reserving paragraph (a). 

■ 3. In § 52.2220 amend Table 1 in 

paragraph (c) by revising the entry for 

‘‘Section 1200–3–27–.12’’ to read as 

follows: 

§ 52.2220 Identification of plan. 

* * * * * 

(c) * * * 

TABLE 1—EPA APPROVED TENNESSEE REGULATIONS

State citation Title/subject State effective 

date EPA approval date Explanation 

*******

CHAPTER 1200–3–27 NITROGEN OXIDES 

*******

Section 1200–3–27–.12 NOX SIP Call Requirements for Stationary Boilers and Combustion Turbines.

12/12/2019 3/2/2021, [Insert citation 

of publication].

* * * * * 

[FR Doc. 2021–04061 Filed 3–1–21; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R05–OAR–2010–0037; FRL–10019– 

32–Region 5] 

Air Plan Approval; Minnesota; 

Revision to Taconite Federal 

Implementation Plan 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is revising a Federal 

implementation plan (FIP) addressing 

the requirement for best available 

retrofit technology (BART) for the 

United States Steel Corporation’s (U.S. 

Steel) taconite plant located in Mt. Iron, 

Minnesota (Minntac or Minntac 

facility). We are revising the nitrogen 

oxides (NOX) limits for U.S. Steel’s 

taconite furnaces at its Minntac facility 

because new information has come to 

light that was not available when we 

originally promulgated the FIP on 

February 6, 2013. The EPA is finalizing 

this action pursuant to sections 110 and 

169A of the Clean Air Act (CAA or the 

Act). 


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1See ‘‘US Steel Comments—Proposed FIP MN 

and MI’’ and ‘‘10–15–2012 email from C. Bartovich 

to S. Rosenthal’’ and attachments, included in the 

docket. 

2See ‘‘IV.F. U.S. Steel Minntac Line 6 Low NOX

Burner Final Report, December 1, 2011,’’ ‘‘III.F. U.S. 

Steel Minntac9.m. U.S. Steel Minntac Line 7 Burner 

Final Report, May 13, 2011,’’ and ‘‘Final Report 

Line 4 Burner 092917,’’ included in the docket. 

DATES: This final rule is effective April 

1, 2021. 

ADDRESSES: EPA has established a 

docket for this action under Docket ID 

No. EPA–R05–OAR–2010–0037. All 

documents in the docket are listed in 

the http://www.regulations.gov website. 

Although listed in the index, some 

information is not publicly available, 

e.g., Confidential Business Information 

or other information whose disclosure is 

restricted by statute. Certain other 

material, such as copyrighted material, 

is not placed on the internet and will be 

publicly available only in hard copy 

form. Publicly available docket 

materials are available either through 

http://www.regulations.gov or at the 

EPA Region 5 office (please contact the 

person identified in the FOR FURTHER

INFORMATION CONTACT section for 

availability information). 

FOR FURTHER INFORMATION CONTACT: 

Kathleen D’Agostino, Environmental 

Scientist, Attainment Planning & 

Maintenance Section, Air Programs 

Branch (AR–18J), U.S. Environmental 

Protection Agency, Region 5, 77 West 

Jackson Boulevard, Chicago, Illinois 

60604, (312) 886–1767, 

dagostino.kathleen@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this document whenever 

‘‘we,’’ ‘‘us,’’ or ‘‘our’’ is used, we mean 

EPA. 

I. Background Information 

On February 6, 2013, EPA 

promulgated a FIP that included BART 

limits for certain taconite furnaces in 

Minnesota and Michigan (2013 Taconite 

FIP; 78 FR 8706). On February 4, 2020, 

EPA proposed to revise the 2013 

Taconite FIP with respect to the NOX

BART emission limitations and 

compliance schedules for U.S. Steel’s 

Minntac facility in Minnesota. (85 FR 

6125). 

Specifically, EPA proposed that an 

aggregate emission limit of 1.6 lbs NOX

per million British Thermal Unit 

(MMBtu), based on a 30-day rolling 

average, averaged across Minntac’s five 

production lines, represents NOX BART 

for the Minntac facility. An explanation 

of the CAA requirements, a detailed 

analysis of how these requirements 

apply to U.S. Steel’s Minntac facility, 

and EPA’s reasons for proposing the 

revised limit and compliance schedule 

were provided in the notice of proposed 

rulemaking (NPRM) and will not be 

restated here. The public comment 

period for this proposed rule ended on 

March 5, 2020. 

One commenter stated that EPA did 

not provide information regarding a 

public hearing and did not ask the 

public if they were interested in a 

public hearing. To address this 

comment, EPA held a virtual public 

hearing on October 14, 2020, and 

reopened the public comment period. 

The second comment period closed on 

November 13, 2020. The commenter 

also stated that EPA did not 

demonstrate that the agency consulted 

with Federal Land Managers (FLMs) 

regarding the proposed FIP revision. In 

response to this comment, EPA engaged 

with the FLMs on the revision to the 

taconite FIP for Minntac. The FLMs 

have indicated that they have no 

comments on the FIP revision. 

II. Public Comments 

During the first comment period EPA 

received adverse comments submitted 

on behalf of the National Parks 

Conservation Association and the 

Minnesota Center for Environmental 

Advocacy, an adverse comment 

submitted anonymously, and a 

comment from a private citizen in 

support of the February 4, 2020 

proposal. We also received an 

anonymous comment that addresses 

subjects outside the scope of our 

proposed action. The adverse comments 

are summarized and addressed below. 

No one presented testimony at the 

October 14, 2020 virtual public hearing. 

The transcript of the hearing is available 

in the docket. We received no comments 

during the second comment period. 

Comment 1: The 2013 FIP included 

case-by-case determinations and 

emission limits for each of the BART 

units at Minntac, as follows: 1.2 lbs 

NOX/MMBtu when burning natural gas 

and 1.5 lbs NOX/MMBtu when co-firing 

coal and natural gas. This was done in 

accordance with the CAA where BART 

is defined as ‘‘an emission limitation 

based on the degree of reduction 

achievable through the application of 

the best system of continuous emission 

reduction for each pollutant which is 

emitted by an existing stationary 

facility.’’ This emission limit is to be 

established on a case-by-case basis after 

considering the five statutory factors. 

EPA’s 2020 proposal would provide a 

single facility-wide NOX BART limit of 

1.6 lbs/MMBtu that will apply on a 

rolling 30-day basis. Contrary to the 

CAA and BART Guidelines, for each 

Minntac source subject to BART, EPA 

abandons its 2013 BART determination 

and now proposes a FIP revision that 

neglects its obligation to ensure limits 

reflect BART emission rates that are of 

the appropriate type and level for each 

source subject to BART. Without revised 

individual BART determinations for 

each of the five Minntac units EPA 

cannot demonstrate that reductions 

achieved by the facility-wide limit will 

be equal to the reductions obtained by 

controlling the individual units. While 

the Minntac Spreadsheet in the docket 

contains information on 95th and 99th 

percentile and highest 720-hour 

averages, it seems EPA decided to 

ignore the percentile values, and rather 

propose U.S. Steel’s averaging approach. 

Response: The August 15, 2012 

Proposed FIP (77 FR 49312–49313) 

included a five-step BART analysis for 

Minntac’s five lines (Lines 3–7). The 

five-step analysis was conducted in 

accordance with the BART Guidelines, 

appendix Y to 40 CFR part 51. EPA 

proposed BART emission limits of 1.2 

lbs NOX/MMBtu measured on a 30-day 

rolling average based on the use of low 

NOX burners. EPA’s analysis and 

proposed determination that BART is 

based upon the use of low NOX burners 

remains valid. In the February 6, 2013 

Final FIP (78 FR 8706), based on a 

comment from U.S. Steel regarding the 

appropriate emission limit when 

burning solid fuels and supplementary 

data submitted by U.S. Steel on October 

15, 2012,1 EPA finalized a limit for each 

of Minntac’s five lines of 1.5 lbs NOX/ 

MMBtu measured on a 30-day rolling 

average; however, a limit of 1.2 lbs 

NOX/MMBtu measured on a 30-day 

rolling average would apply for any 30 

or more consecutive days when only 

natural gas is used. The final 2013 FIP 

limits reflected what EPA determined 

could be reasonably achieved by the use 

of low NOX burners at taconite furnaces 

based on the limited emission data 

available. 

At the time EPA promulgated the 

BART emission limits for Minntac, low 

NOX burners had only been in operation 

on Minntac Lines 6 and 7 since April 

2011 and May 2010, respectively, and 

there were very little emission data 

available upon which to base a limit. 

Since promulgation of the FIP, however, 

U.S. Steel submitted continuous 

emission monitoring system (CEMS) 

data demonstrating that despite having 

optimized each burner,2 Minntac is 

unable to comply with the 1.2 lbs NOX/ 

MMBtu limit at all times when burning 

only natural gas. 

EPA continues to rely on the BART 

analysis set forth in the August 15, 2012 

proposal concerning the selection of low 

NOX burners as the appropriate BART 


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3U.S. Steel installed low NOX burners on Lines 

4 and 5 on December 15, 2016, and December 20, 

2015, respectively. 

4Operations at Minntac in a given 30-day period, 

or even a single day, may in some cases involve 

both operation with only natural gas and operation 

with at least some firing of solid fuels. To be able 

to evaluate emissions from all hours when different 

fuels were used within a 30-day period, rather than 

only the times when a line used solely natural gas 

or solely co-fired for 30 consecutive days, EPA 

evaluated emissions based on 720-hour averages. 

Note that operations are typically 24 hours per day 

and 720 is the number of hours in a 30-day period. 

5See Lines 3, 4, and 5 Data-L4_7 NOX Data files 

combined,’’ included in the docket. 

technology. However, since EPA 

promulgated the BART limits for 

Minntac, U.S. Steel has continued to 

operate low NOX burners on Lines 6 and 

7 and has installed low NOX burners on 

Lines 4 and 5.3 There are significantly 

more data available from which to 

determine whether the BART FIP 

emission limits are actually achievable 

through the utilization of low NOX

burners at Minntac. To reevaluate the 

emission limit achievable by use of low 

NOX burners, EPA analyzed available 

hourly CEMS data showing emissions in 

lbs NOX/MMBtu by fuel type. These 

data were available for the 2012–2017 

time period. From this data set, EPA 

then compiled the emission data 

available for each line after the 

installation of low NOX burners. For 

Line 4, this included data from 

December 15, 2016 through November 

19, 2017. For Line 5, this included data 

from December 12, 2015 through 

November 11, 2017. For Lines 6 and 7, 

emission data were available from May 

8, 2012 and April 27, 2012 through 

November 11, 2017, respectively. There 

are necessarily differing amounts of 

CEMS data for each line since the low 

NOX burners were installed at different 

times. 

To ensure that any revised emission 

limit would be based upon emission 

reduction capabilities during normal 

operations, EPA excluded hours when a 

line was idle, when a measurement 

error was recorded, or when process or 

CEMS codes indicated anything other 

than normal operation. For each line, 

EPA separated hours when only natural 

gas was burned from hours when the 

line was co-fired with coal (Lines 6 and 

7) or co-fired with biomass (Lines 4 and 

5). EPA then calculated 720-hour rolling 

averages based upon fuel type.4 To 

establish an achievable emission limit, 

EPA assessed the highest 720-hour 

average, the 99th percentile 720-hour 

average, and the 95th percentile 720- 

hour average.5 The 99th percentile is the 

emission rate that the source would be 

predicted to be below during 99 out of 

100 720-hour averages. The 95th 

percentile is the emission rate that the 

source would be predicted to be below 

during 95 out of 100 720-hour averages. 

The highest 720-hour average is the 

emission rate at which the source would 

be predicted to be able maintain 

continual compliance. 

Under the BART Guidelines, a source 

may be permitted to average emissions 

across a set of BART-eligible emission 

units within a fenceline, so long as the 

emission reductions from each pollutant 

being controlled for BART would be 

equal to those reductions that would be 

obtained by simply controlling each of 

the BART-eligible units that constitute 

the BART-eligible source. See 40 CFR 

part 51, appendix Y, at V. U.S. Steel 

expressed interest in utilizing this 

option. As shown in Table 1 below, 

averaging the individual limits across 

Lines 4 through 7 for natural gas results 

in a combined emissions limit of 1.6 lbs 

NOX/MMBtu averaged over 720 hours, 

regardless of whether the single line 

emission limit basis for the cross-line 

average was the highest 720-hour 

average, the 99th percentile 720-hour 

average, or the 95th percentile 720-hour 

average. 

TABLE 1—INDIVIDUAL LINE AND CROSS-LINE AVERAGING EMISSION RATES FOR LINES 4 THROUGH 7 

Fuel 

High 

720-hr 

average 

lbs NOX/ 

MMBtu 

99% 

720-hr 

average 

lbs NOX/ 

MMBtu 

95% 

720-hr 

average 

lbs NOX/ 

MMBtu 

Line 4 .............................................................. Natural Gas .................................................... 1.5 1.5 1.5 

All Fuels ......................................................... 1.5 1.4 1.4 

Line 5 .............................................................. Natural Gas .................................................... 1.4 1.4 1.4 

All Fuels ......................................................... 1.4 1.4 1.3 

Line 6 .............................................................. Natural Gas .................................................... 1.7 1.6 1.6 

All Fuels ......................................................... 1.7 1.6 1.4 

Line 7 .............................................................. Natural Gas .................................................... 1.9 1.8 1.8 

All Fuels ......................................................... 1.9 1.8 1.7 

Cross-line Average .................................. Natural Gas .................................................... 1.6 1.6 1.6 

All Fuels ......................................................... 1.6 1.6 1.5 

While Line 3 will not become subject 

to the FIP limits until July 2021, U.S. 

Steel has indicated that, when 

compared to the other lines, the Line 3 

burner is most similar to Line 4. Line 4 

is more similar in age, size and design 

to Line 3 than the other lines. Line 3 

utilizes the same fuels (natural gas and 

biomass) as Line 4, and both Lines are 

managed by the same control room 

operators. In addition, operating 

parameters on Line 3 are similar to Line 

4 for such measured parameters as Kiln 

Exit Temperature, Preheat Zone 

Temperature, Burner Temperature, and 

Pellet Residence time on the grate and 

in the kiln. Absent an engineering study 

for Line 3, using the emission rates for 

Line 4 as an estimate of the emission 

rates that would be expected after 

installation of a low NOX burner on Line 

3 is reasonable. Therefore, EPA also 

calculated a cross-line average 

considering actual emissions from all 

four lines currently utilizing low NOX

burners (Lines 4 through 7), as well as 

the expected emissions from Line 3. The 

resulting cross-line average is 1.6 lbs 

NOX/MMBtu averaged over 720 hours, 

regardless of selection of statistical 

analyses at the 99th or 95th percentiles, 

or highest 720-hour average. 

While the 1.6 lbs NOX/MMBtu limit 

for Minntac is reflective of natural gas 

emission data, in response to the 

comment received, EPA calculated 720- 

hour rolling averages for each line over 

the entire period without separating fuel 

types. As provided in Table 1, the data 


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6See Redacted ‘‘U. S. Steel Confidential 

Settlement Communication—Subject to FRE 408,’’ 

May 1, 2018, included in the docket. 

7See ‘‘Minntac CEMS Data and Analysis,’’ 

included in the docket. 

analysis showed that the cross-line 

averages at the highest 720-hour average 

across all data and also at the 99th 

percentile is 1.6 lbs NOX/MMBtu, and at 

the 95th percentile is 1.5 lbs NOX/ 

MMBtu. In addition, review of the 

CEMS data shows that U.S. Steel has 

largely transitioned toward firing with 

natural gas and away from co-firing with 

coal and natural gas. U.S. Steel stated 

that it ‘‘has been primarily combusting 

natural gas since December 2016.’’ 6 As 

previously stated, only two of Minntac’s 

five lines (Lines 6 and 7) are capable of 

burning coal, and CEMS data show that 

U.S. Steel has largely shifted its 

operations on Lines 6 and 7 away from 

co-firing with coal and natural gas and 

toward firing exclusively natural gas. 

While Lines 6 and 7 co-fired with coal 

and natural gas 85% of the time in 2012, 

these lines co-fired with coal and 

natural gas only 3% of the time in 

2017.7

EPA has determined that the 1.6 lbs 

NOX/MMBtu cross-line emission limit 

constitutes the appropriate BART 

emission limit for Minntac Lines 3 

through 7, regardless of fuel type. As 

previously discussed, the BART 

Guidelines provide that a source may be 

permitted to average emissions across a 

set of BART-eligible units within a 

fenceline, so long as the emission 

reductions from each pollutant 

controlled for BART would be equal to 

those reductions that would be obtained 

by separately controlling each of the 

BART-eligible units that constitute the 

BART-eligible source. 40 CFR part 51, 

appendix Y, at V. Minntac Lines 3, 4, 5, 

6, and 7 are all BART-eligible units that 

constitute a BART-eligible source 

within a fenceline. When averaging the 

level of NOX emission reductions 

achievable on each of Minntac Lines 3 

through 7 individually, the resulting 

limit is 1.6 lbs NOX/MMBtu when 

burning natural gas. Therefore, it is 

reasonable for EPA to establish a single 

cross-line average emission limit of 1.6 

lbs NOX/MMBtu, to apply at all times, 

for Minntac Lines 3 through 7. 1.6 lbs 

NOX/MMBtu is the most stringent limit 

the facility can consistently meet while 

providing for operational flexibility 

with regard to fuel choice, including 

burning exclusively natural gas. 

Comment 2: EPA’s proposal lacks 

alternative BART emission limits based 

on the type of fuel each line will burn 

under the FIP. Although the BART 

Guidelines are fuel-neutral, where a 

source wants to operate under different 

scenarios and burn different fuels that 

create different levels of BART pollutant 

emissions, EPA must first set alternative 

BART emission limits for each unit 

based on fuel use. EPA’s 2013 FIP 

promulgated two BART emission limits 

based on fuel use, which apply to all 

five BART units: A limit when burning 

natural gas, and second limit when cofiring coal and natural gas. The record 

indicates the BART units historically 

used a variety of fuels, which included: 

Coal; wood; co-firing; biomass; and 

natural gas. EPA’s proposed facilitywide BART limit relies on emission data 

collected when only one fuel was used, 

natural gas. EPA fails to analyze the 

range of fuels burned at Minntac and 

how the fuel burned impacts revising 

the prior BART determinations. 

Response: EPA disagrees with the 

commenter’s contention that EPA must 

set alternative BART emission limits for 

each unit based on fuel use. Neither the 

CAA nor the regional haze rule requires 

EPA to establish separate BART limits 

based on fuel type. While the 1.6 lbs 

NOX/MMBtu limit for Minntac is 

reflective of natural gas emission data, 

EPA evaluated all available CEMS data 

for 2012–2017. These data are reflective 

of scenarios where lines were burning 

exclusively natural gas and scenarios 

when lines were co-firing with solid 

fuels. 

We are under no obligation to set fuelspecific limits and are not doing so here. 

EPA has determined that 1.6 lbs NOX/ 

MMBtu is the most stringent limit the 

facility can consistently meet while 

providing for operational flexibility 

with regard to fuel choice, including 

burning exclusively natural gas. As 

discussed previously in response to 

Comment 1, in response to comments 

received, EPA calculated 720-hour 

rolling averages for each line over the 

entire period without separating fuel 

types (the ‘‘All Fuels’’ scenario). The 

data demonstrate that the cross-line 

averages at the highest 720-hour average 

across all data and also at the 99th 

percentile is 1.6 lbs NOX/MMBtu, and at 

the 95th percentile is 1.5 lbs NOX/ 

MMBtu. However, as previously 

explained, to allow for fuel choice and 

a scenario in which the facility burns 

only natural gas, 1.6 lbs NOX/MMBtu is 

the appropriate limit for the facility. 

Comment 3: The agency suggests 

using the new data to revise the five 

BART determinations in its 2013 FIP. 

EPA fails to provide a reasoned analysis 

for using the new data to revise its prior 

determination. EPA’s prior 

determination found that once low NOX

burners were installed and burned 

natural gas, NOX emissions were lower 

than when co-firing coal and natural 

gas, and therefore, based the 2013 FIP 

BART emission limits on its record and 

findings. EPA’s 2020 proposal flips its 

prior determination, contending that 

NOX emissions are higher when burning 

only natural gas, as compared to cofiring coal and natural gas. 

Response: EPA’s August 15, 2012 

proposed FIP approval includes an 

analysis and proposed determination 

that BART for Minntac is based upon 

the use of low NOX burners. In the 2013 

FIP final rule, EPA finalized this 

determination. EPA’s analysis 

concerning low NOX burners as 

representing BART for Minntac 

continues to remain valid and it is 

appropriate for EPA to rely on it in this 

action. As discussed above, at the time 

EPA established limits in the 2013 FIP, 

low NOX burners had only been in 

operation on Lines 6 and 7 since April 

2011 and May 2010, respectively, and 

there were limited emission data 

available upon which to base a limit. 

However, since that time, U.S. Steel has 

continued to operate low NOX burners 

on Lines 6 and 7 and has installed low 

NOX burners on Lines 4 and 5. 

Therefore, as discussed in the response 

to Comment 1, there are significantly 

more data available from which to 

determine whether the BART FIP 

emission limits are actually achievable 

through the utilization of low NOX

burners at Minntac. 

Comment 4: EPA’s approach is not 

permissible under the Act. Instead of 

proposing BART emission limits based 

on maximum controls, EPA’s proposal 

uses the new data from the operating 

scenario that is the least effective at 

controlling NOX emissions to derive a 

BART emission limit, and then suggests 

applying the least effective control at all 

five BART units, regardless of what the 

unit burns. 

Response: The control technology 

used as the basis for establishing BART 

limits in the 2013 FIP has not changed. 

Since promulgation of the 2013 FIP, 

however, our understanding of the 

emissions levels achievable through the 

use of this technology has changed. The 

emission limits initially promulgated 

under the 2013 FIP were based on the 

installation and optimization of a low 

NOX burner on Lines 6 and 7, and the 

limited CEMS data available at that 

time. Since promulgation of the 2013 

FIP, U.S. Steel has continued to collect 

CEMS data from Lines 6 and 7. U.S. 

Steel has also installed low NOX burners 

on Lines 4 and 5, has adjusted and 

optimized each of those burners to 

reduce NOX, and has collected CEMS 

data for each of the lines. EPA based the 

1.6 lbs NOX/MMBtu limit on the 


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8See ‘‘Minntac CEMS Data and Analysis,’’ 

included in the docket. 

9See ‘‘Lines 3, 4, and 5 Data-L4_7 NOX CEMS 

Data files combined.’’ 

10Commenter refers to a figure provided by 

commenter that purports to show 2002 baseline 

emissions from Minnesota’s state implementation 

plan (SIP) submittal along with plots of facilitywide NOX emissions in tons per year (tpy) and 

facility-wide production for the period 2007 

through 2018. See NPCA and MCEA Comments on 

the Proposed Revision to Minnesota Taconite 

Federal Implementation Plan for U.S. Steel 

Minntac, at p. 11, Figure 2. 

11Note commenter used incorrect numbers 

14,294 vs 14,924. 

12See 40 CFR 51.301. 

emission rates demonstrated by the 

CEMS data to be achievable by low NOX

burners, which is the technology 

determined to be the basis for BART. 

The 1.6 lbs NOX/MMBtu limit is the 

most stringent limit the facility can 

consistently meet while providing for 

operational flexibility with regard to 

fuel choice. Contrary to commenter’s 

assertion, EPA did not base the 1.6 lbs 

NOX/MMBtu limit on the projected 

emission rates achievable by the least 

effective control technology. 

Comment 5: There is nothing in the 

record to suggest all lines will be 

capable of and restricted to burning 

natural gas nor that the company plans 

to burn natural gas exclusively. 

Response: The CEMS data clearly 

demonstrate that all lines are capable of 

burning natural gas. EPA is not 

restricting U.S. Steel to only burning 

natural gas at Minntac. Should U.S. 

Steel choose to periodically co-fire with 

coal or biomass on one or more of its 

lines, the facility will remain subject to 

the 1.6 lbs NOX/MMBtu limit regardless 

of fuel type. 

Comment 6: EPA fails to provide a 

basis for the cherry-picked and 

incomplete data. EPA’s NPRM notes it 

evaluated six years of CEMS data, not 

specifying which years were evaluated. 

EPA provides neither an analysis of nor 

a justification for using such disparate 

data. While EPA explains the data 

represent operations at the taconite 

furnaces under various production 

scenarios, it fails to explain what these 

scenarios are and whether they 

represent the full range of future 

scenarios. EPA provides no explanation 

to justify its use of this limited data set. 

Response: As described previously, 

EPA used the full suite of CEMS data 

available for each line after the 

installation of low NOX burners. The 

document entitled ‘‘Minntac CEMS Data 

and Analysis,’’ included in the docket, 

identifies the date and hour of each 

emission data point used in the 

calculations. The earliest data available 

that provided hourly NOX emission data 

in lbs NOX/MMBtu along with the 

corresponding fuel type began in 2012 

and was provided through 2017. From 

this data set, EPA then compiled the 

emission data available for each line 

after the installation of low NOX

burners. For Line 4, this included data 

from December 15, 2016 through 

November 19, 2017. For Line 5, this 

included data from December 12, 2015 

through November 11, 2017. For Lines 

6 and 7, emission data were available 

from May 8, 2012 and April 27, 2012, 

respectively, through November 11, 

2017. There are necessarily differing 

amounts of data for each line since the 

low NOX burners were installed at 

different times. To establish a limit 

based on emissions reflective of normal 

operating conditions, EPA excluded 

hours when the process was idle, when 

a measurement error was recorded, or 

when process or CEMS codes indicated 

anything other than normal operation. 

With respect to operating scenarios, 

EPA does not claim that the data 

evaluated represent the full range of 

possible future operating scenarios. 

Rather, the initial emission limits in the 

2013 FIP were based upon very limited 

CEMS data from Lines 6 and 7. 

Operations at Lines 6 and 7 over the 

2012–2017 time period showed varying 

production levels, fuels, pellet types 

and different ore mixes. In addition, we 

now have CEMS data for Lines 4 and 5 

reflecting the installation of low NOX

burners. The available CEMS data 

provide information on NOX emissions 

over time which encompass more 

operating scenarios than were 

represented by the limited data 

available at the time EPA promulgated 

the 2013 FIP. As the CEMS data 8

available in the docket show, the 1.2 lbs 

NOX/MMBtu limit promulgated under 

the 2013 FIP and intended to apply 

when burning only natural gas cannot 

be consistently achieved at Minntac 

during normal operations with low NOX

burners. 

Comment 7: Although EPA’s NPRM 

explains that U.S. Steel also provided 

hourly NOX emissions data in lbs/ 

MMBtu for Line 3, which has not yet 

installed low NOX burner technology, 

the NPRM provides no information on 

where this information is available. 

Response: This information was 

erroneously omitted from the docket. 

The docket has been updated to include 

this information.9

Comment 8: For the past ten years, 

2009 through 2018, the NOX emissions 

reported by U.S. Steel have been 

relatively constant. EPA fails to explain 

why emissions remain constant even 

though U.S. Steel reports it installed 

low NOX burners on four of the five 

lines subject to BART. EPA also fails to 

provide an explanation for why there 

has been an increase in NOX emissions 

in the years following installation of the 

low NOX burner. This suggests that U.S. 

Steel did not optimize the low NOX

burners from 2014 through 2017.10

Response: Commenter references a 

figure provided by commenter that: (1) 

Shows the 2002 baseline annual 

emissions for Minntac included in 

Minnesota’s December 30, 2014 FiveYear Regional Haze Progress Report SIP 

submittal,11 and (2) plots annual 

production and annual NOX emissions 

at Minntac. The figure does not 

accurately reflect U.S. Steel’s 

implementation and optimization of low 

NOX burners at Minntac. First, the 

annual NOX emissions included in the 

commenter’s figure do not represent 

annual emissions from only the 

indurating furnaces, but rather represent 

facility-wide NOX emissions. Second, by 

definition, BART is ‘‘based on the 

degree of reduction achievable through 

the application of the best system of 

continuous emission reduction.’’ 12 EPA 

is setting a cross-line average for 

Minntac Lines 3 through 7 of 1.6 lbs 

NOX/MMBtu, averaged over 30 days, 

which is a rate-based limit based on the 

degree of reduction achievable through 

the use of low NOX burners. Commenter 

conflates the rate-based emission limit 

with total annual NOX emissions from 

the facility. Since we are setting a ratebased emission limit, which does not 

constrain production levels, total annual 

NOX emissions may fluctuate in a given 

year even while the source is in 

compliance with its BART emission 

rate. For example, if production 

increases, total NOX emissions in tons 

per year would be expected to increase 

as well. If production decreases, total 

NOX emissions in tons per year (tpy) 

would be expected to decrease. Under 

all production scenarios, the lbs of NOX/ 

MMBtu rate-based emission limit 

remains applicable. Finally, the 

production levels shown in the figure 

represent facility-wide production. The 

figure provided by the commenter does 

not differentiate production 

contributions by line, i.e., what 

percentage of total production comes 

from individual lines which had low 

NOX burners installed at the time vs. 

lines which did not have low NOX

burners installed at the time. 

Notwithstanding the above-noted 

limitations regarding the figure 

provided by the commenter, 

nonetheless, some information can be 

gained by looking at the difference 

between production and emissions over 

time, as represented by the distance 


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13See ‘‘Emission reduction estimates’’ and ‘‘Lines 

3, 4, and 5 Data-L4_7 NOX CEMS Data files 

combined for docket,’’ included in the docket. 

14U.S. Steel installed low NOX burners on Lines 

4 and 5 on December 15, 2016, and December 20, 

2015, respectively. 

between the NOX line and production 

line in the figure. From 2007 through 

2009, before the installation of low NOX

burners, these lines are relatively close 

together. In 2010, the year when the low 

NOX burner was installed on Line 7, 

production rose dramatically while 

annual NOX emissions did not. Visually, 

there is a significant divergence between 

the NOX and production lines in the 

figure, indicating an increase in 

production without a commensurate 

increase in emissions. Correspondingly, 

after the low NOX burner was installed 

on Line 6 in 2011, the figure shows 

production increased between 2010 and 

2011 while emissions decreased. Low 

NOX burners were installed on Lines 5 

and 4 in December 2015 and December 

2016, respectively. Similarly, the figure 

shows NOX emissions between 2015 

and 2017 did not increase at the same 

rate as production. 

Using the available CEMS data for the 

2012–2017 time period, EPA further 

evaluated the differences between 

various NOX emission values pre and 

post-installation of low NOX burners on 

Lines 4 and 5.13 Data for both lines 

showed a decrease in the average lbs 

NOX/MMBtu, high 720-hour average lbs 

NOX/MMBtu, and 99th percentile lbs 

NOX/MMBtu. Even the average lbs NOX/ 

hour, which does not account for 

variations in production levels, 

decreased. U.S. Steel did not provide 

CEMS data for Lines 6 and 7 for the 

period prior to the installation of low 

NOX burners, so a similar comparison 

cannot be made for these lines. 

Finally, the commenter asserts that 

the data suggest that U. S. Steel failed 

to optimize operation of the low NOX

burners from 2014 through 2017. As 

discussed in detail in responses to 

comments 9 and 14 in this document, 

after installation of the low NOX burner 

on each line, U.S. Steel optimized 

burner operation for NOX reduction 

while maintaining pellet quality. In 

addition, Minntac has remained subject 

to the limits in the 2013 FIP. 

Comment 9: EPA did not explain how 

U.S. Steel arrived at its conclusion that 

the low NOX burners at each of the lines 

were optimized and functioning at their 

best. In prior regional haze actions, 

when the level of control has been 

uncertain at the time of EPA’s final 

action, EPA requires a control 

technology demonstration, with explicit 

requirements for optimization of the 

control technology system. EPA’s 2014 

final FIP requirements for Arizona 

plants included a control technology 

demonstration project for the emission 

control system at each plant, which 

entailed the collection of data and 

preparation of an optimization protocol 

that would be used to determine if a 

higher control efficiency would be 

achievable. There is no evidence that 

EPA required and oversaw 

implementation of a control technology 

project. Moreover, the BART Guidelines 

require the consideration of 

improvements to the low NOX burner 

controls (40 CFR part 51, appendix Y, at 

IV. D. Step 1¶ 9). 

Response: U.S. Steel has documented 

optimization studies at Lines 4, 5, 6, and 

7 in final testing reports for each line. 

Final testing reports for Lines 6 and 7 

and preliminary data for Lines 4 and 5 

are included in the docket. In addition, 

U.S. Steel submitted final testing reports 

for Lines 4 and 5, titled ‘‘Final Report 

Line 4 Burner 092917.’’ This document 

has also been added to the docket. In 

each report, U.S. Steel describes 

challenges encountered over the course 

of installing, operating, and testing each 

low NOX burner, and discusses how 

certain design and operational changes 

were found to optimize operation of 

each line’s low NOX burners. As 

explained in the reports, U.S. Steel 

evaluated operation of each low NOX

burner to ensure each burner can 

operate in a manner that reduces NOX

emissions while making pellets that 

meet quality specifications. Each burner 

was evaluated according to hourly 

CEMS data and during expected 

operating scenarios, including while 

burning natural gas, solid fuels, and a 

combination of natural gas and solid 

fuels. Over the course of the testing, 

U.S. Steel identified several problems 

occurring at various stages of low NOX

burner operation and prescribed specific 

design and operational changes to 

improve operation in each scenario. 

U.S. Steel states that each of the 

proposed solutions and design 

changes—including adding blowers, 

increasing combustion air fan speed and 

capacity, adding rings to combustion air 

annuli, and adjusting and monitoring 

atomizing air and gas splits—were 

implemented in consultation with the 

burner manufacturer to optimize low 

NOX burner operation and NOX

reduction. In each case, U.S. Steel 

determined optimization of the low 

NOX burners involves achieving 

stoichiometric ratios of air to fuel at 

levels that create a tight flame shape in 

order to minimize NOX while ensuring 

proper process operation. U.S. Steel 

continues to monitor CEMS data and 

burner parameters to ensure the burners 

are operating effectively. 

As explained in response to 

Comments 1 and 3, at the time EPA 

established limits in the 2013 FIP, low 

NOX burners had only been in operation 

on Lines 6 and 7 since April 2011 and 

May 2010, respectively, and there were 

limited CEMS data available upon 

which to base a limit. However, since 

EPA promulgated the initial BART 

limits for Minntac in the 2013 FIP, U.S. 

Steel has continued to operate low NOX

burners on Lines 6 and 7 and has 

installed low NOX burners on Lines 4 

and 5.14 There are significantly more 

data available from which to determine 

whether the 2013 FIP emission limits 

are actually achievable through the 

utilization of low NOX burners at 

Minntac. In addition, and as noted 

above, U.S. Steel has submitted final 

testing reports for Lines 4 through 7 that 

detail U.S. Steel’s optimization efforts 

for each of these low NOX burners. In 

contrast to the scenario cited by 

commenter where the control 

technology had not yet been installed 

and only minimal data were available 

regarding performance of the control 

technology at issue, EPA is basing the 

revised limit for Minntac on actual 

CEMS data. U.S. Steel has also provided 

information concerning its low NOX

burner optimization efforts for Minntac 

Lines 4 through 7 and has provided 

post-optimization emissions data for 

Lines 4 through 7. 

In the Arizona 2014 Regional Haze 

FIP (79 FR 52420) cited by the 

commenter, EPA stated the following 

with regard to Selective Non-Catalytic 

Reduction (SNCR) at lime kilns: ‘‘While 

this type of control technology 

demonstration is not typically required 

as part of a regional haze plan, we 

consider it to be appropriate here, given 

the minimal data available about the 

performance of SNCR at lime kilns.’’ (79 

FR 52440). With regard to SNCR at 

cement kilns, we explained, ‘‘While this 

type of control technology 

demonstration is not typically required 

as part of a regional haze plan, we 

consider it to be appropriate here, given 

the significant variability in control 

efficiencies achievable with SNCR at 

cement kilns.’’ (79 FR 52456; 79 FR 

52462). The control technologies 

required for lime kilns and cement kilns 

in the 2014 Arizona FIP had not yet 

been installed at the time the Arizona 

FIP was promulgated. This is a different 

scenario than the situation we are 

addressing with regard to Minntac. 

Commenter cites to the BART 

Guidelines at 40 CFR part 51, appendix 


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15See ‘‘Minntac CEMS Data and Analysis,’’ 

Docket ID # EPA–R05–OAR–2010–0037–0110, 

available at https://www.regulations.gov/ 

document?D=EPA-R05-OAR-2010-0037-0110. We 

note that the document, Redacted US Steel Proposal 

to EPA Minntac 5–1–2018, was erroneously listed 

on regulations.gov as an attachment to Minntac 

CEMS Data and Analysis under Docket ID # EPA– 

R05–OAR–2010–0037–0110. Minntac CEMS Data 

and Analysis and Redacted US Steel Proposal to 

EPA Minntac 5–1–2018 are two distinct documents. 

Minntac CEMS Data and Analysis is an Excel file 

containing EPA’s analysis of CEMS data for 

Minntac. Redacted US Steel Proposal to EPA 

Minntac 5–1–2018 is a redacted version of a 

settlement communication provided by U.S. Steel 

to EPA. While Redacted US Steel Proposal to EPA 

Minntac 5–1–2018 remains available under Docket 

ID # EPA–R05–OAR–2010–0037–0110, it may also 

be found under its own Docket ID # EPA–R05– 

OAR–2010–0037–0109, available at https://

www.regulations.gov/document?D=EPA-R05-OAR2010-0037-0109. 

Y, at IV. D. Step 1¶ 9. However, section 

IV.D. addresses the five steps of a caseby-case BART analysis, with Step 1 

being the identification of all available 

retrofit control technologies. As 

discussed in response to Comment 1, 

the August 15, 2012 Proposed FIP (77 

FR 49312–49313) included a five-step 

BART analysis for Minntac’s five lines 

(Lines 3–7). The five-step analysis was 

conducted in accordance with the BART 

Guidelines. EPA’s analysis and 

proposed determination that BART is 

based upon the use of low NOX burners 

remains valid and EPA continues to rely 

upon that analysis. We are not 

conducting a new five-step BART 

analysis. In this action, we are only 

revising the NOX emission limits for 

Minntac to reflect the level of emission 

reductions consistently achievable by 

low NOX burners, which is the control 

technology determined to represent 

BART for Minntac in the 2013 FIP. 

Comment 10: 42 U.S.C. 7607(d)(2) 

requires that EPA’s proposed action 

include ‘‘the methodology used in 

obtaining the data.’’ While the docket 

includes an Excel spreadsheet of CEMS 

data, there is no explanation provided 

regarding the methodology and test 

methods used to obtain the data. 

Furthermore, there is nothing in the 

record to indicate U.S. Steel’s recent 

data was accompanied by a certification 

statement. Therefore, EPA’s proposal 

fails to comply with the Act’s 

methodology disclosure requirements 

and the public is unable to confirm 

accuracy and completeness of the data. 

Response: 42 U.S.C. 7607(d)(2) 

includes requirements pertaining to the 

establishment of a rulemaking docket. 

42 U.S.C. 7607(d)(3), however, does 

require EPA to include a summary of 

‘‘the methodology used in obtaining the 

data and in analyzing the data.’’ At 

proposal, we explained how EPA 

obtained the CEMS data. Specifically, 

we stated, ‘‘[t]o justify this limit, U.S. 

Steel provided EPA with hourly NOX

emissions data in lbs/MMBTU 

documenting actual emissions levels 

after installation of [low NOX burner] 

technology on Minntac Lines 4–7. U.S. 

Steel also provided hourly NOX

emissions data in lbs/MMBTU for Line 

3, which has not yet installed [low NOX

burner] technology.’’ (85 FR 6126). 

In response to EPA’s CAA section 114 

request for information regarding 

Minntac, U.S. Steel provided CEMS data 

for Lines 3, 4 and 5 covering the time 

period from January 1, 2012 through 

August 9, 2016 as well as CEMS data for 

Lines 6 and 7 covering the time period 

from July 24, 2015 through August 9, 

2016. The response included a 

certification of the accuracy and 

completeness of the information 

provided. U.S. Steel’s letter responding 

to the CAA section 114 information 

request, as well as the certification, has 

been added to the docket. 

In response to additional requests 

from EPA that were not made under 

CAA section 114, U.S. Steel provided 

CEMS data for Lines 6 and 7 for the 

period of April 27, 2012 through July 

24, 2015 and for Lines 4 through 7 for 

the period of August 2016 to November 

2017. However, Minntac’s CEMS were 

certified on Agglomerator Waste Gas 

Lines 6 & 7 on June 2–3, 2005. The 

CEMS were certified on Waste Gas Lines 

3, 4 & 5 on January 24, 2007, January 31, 

2007 and February 1, 2007, respectively. 

Further, Minntac is subject to the CEMS 

requirements of the 2013 FIP, which 

may be found at 40 CFR 52.1235(c) and 

include the requirement that CEMS ‘‘be 

installed, certified, calibrated, 

maintained, and operated in accordance 

with 40 CFR part 60, appendix B, 

Performance Specification 2 (PS–2) and 

appendix F, Procedure 1.’’ Minntac’s 

title V permit also specifies that the 

CEMS meet the requirements of 40 CFR 

part 60 appendix B and F and 

Minnesota rule 7017 for monitoring and 

testing requirements. Pursuant to their 

title V permit, U.S. Steel must annually 

certify its compliance with title V. EPA 

has no reason to question the accuracy 

and completeness of the CEMS data 

supplied. 

In addition, the document, Minntac 

CEMS Data and Analysis, is included in 

the docket and contains EPA’s analysis 

of the data provided by U.S. Steel.15

Comment 11: While U.S. Steel 

expressed apprehensions about 

fluctuating emissions due to ‘‘concerns 

regarding ore blend,’’ and EPA appears 

to rely on this in proposing to revise the 

FIP, there is no information in the 

record to substantiate ore blend 

variability. Nor is there any information 

in the record that explains how 

fluctuations in ore blend impact the 

ability of low NOX burners to control 

NOX emissions. EPA’s assertions appear 

to suggest that it assumes the 

fluctuations go in one direction, adding 

a ‘‘safety margin’’ to the facility-wide 

limit, without providing a reasoned 

basis. 

Response: EPA did not consider ore 

blends in proposing to revise the FIP. 

EPA did provide a reasoned basis for the 

1.6 lbs NOX/MMBtu emission limit. 

This is the limit demonstrated by the 

CEMS data to be achievable by low NOX

burners, which is the technology 

determined to be the basis for BART. 

The 1.6 lbs NOX/MMBtu limit is the 

most stringent limit the facility can 

consistently meet while providing for 

operational flexibility with regard to 

fuel choice. EPA did not add a safety 

margin to the limit as commenter 

suggests. 

Comment 12: EPA’s proposal suggests 

that given the trajectory of fuel markets, 

EPA has no reason to believe that U.S. 

Steel will not continue to use natural 

gas at Minntac. EPA provides neither 

information about fuel markets nor a 

trajectory. Even if such information 

were provided, reliance on market 

projections is not an acceptable 

justification. Projections are just that, 

merely projections, and EPA lacks 

authority to rely on them. Moreover, in 

responding to the Petitions for 

Reconsideration on its 2013 FIP, EPA 

explained that ‘‘the taconite industry 

has demonstrated that it can re-engineer 

furnaces to adapt to market changes 

(such as fuel prices)’’ and EPA found 

that ‘‘at U.S. Steel’s Minntac facility, 

where low NOX burners have been 

installed and are in operation, there has 

been no fuel penalty.’’ 

Response: The 1.6 lbs NOX/MMBtu 

limit for Minntac represents the most 

stringent limit the facility can 

consistently meet while providing for 

operational flexibility to burn 

exclusively natural gas. As discussed 

previously in response to Comments 2 

and 4, U.S. Steel’s production and fuel 

use data show that U.S. Steel has been 

moving toward using natural gas rather 

than co-firing with coal. Minntac Lines 

6 and 7 (the only lines that capable of 

burning coal) have shifted fuel use 

dramatically over the six years 

evaluated, from 15% natural gas in 2012 

to 97% natural gas in 2017. The 1.6 lbs 

NOX/MMBtu limit represents the most 

stringent limit the facility can 

consistently meet while providing 

operational flexibility with regard to 

fuel choice—including, for example, in 

response to market changes, the option 

to burn exclusively natural gas. Should 


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16Commenter seems to be confusing the order of 

low-NOX burner installation on Lines 6 and 7. Low 

NOX burners were installed on Lines 6 and 7 in 

April 2011 and May 2010, respectively. 

U.S. Steel choose to co-fire with coal or 

biomass on one or more of its lines, the 

facility will remain subject to the 1.6 lbs 

NOX/MMBtu limit regardless of fuel 

type. 

Comment 13: Information in the 

docket indicates U.S. Steel suggested 

the facility-wide emission limit needs to 

be set at a level that includes 

approximately two months of historical 

emission data that were above the 1.5 

lbs NOx/MMBtu limit EPA offered 

during the negotiations. EPA provides 

no explanation for what caused the 

elevated levels. In fact, it’s unclear 

whether EPA attempted to ascertain the 

answer to that question. These elevated 

levels were not seen at the other BART 

units. Without an explanation for this 

limited data, and whether such 

instances will occur during normal 

operations, it is unreasonable, arbitrary 

and capricious for EPA to set a limit that 

includes these operations, which has 

the effect of providing a ‘‘safety 

margin.’’ 

Response: It is unclear what 

information commenter is referencing. 

However, as discussed in greater detail 

in response to Comment 1, EPA 

evaluated and analyzed available hourly 

CEMS data showing emissions in lbs 

NOX/MMBtu and fuel type. These data 

were available for the 2012–2017 time 

period. From this data set, EPA 

compiled the emission data available for 

each line after the installation of low 

NOX burners. EPA then evaluated CEMS 

codes and process codes for each line to 

ensure that the limit would be based 

upon emission reduction capabilities 

during normal operations. EPA 

excluded hours when the process was 

idle, when a measurement error was 

recorded, or when process or CEMS 

codes indicated anything other than 

normal operation. Based upon that data, 

EPA proceeded to calculate achievable 

limits for the individual lines to use as 

a basis for the 1.6 lbs NOX/MMBtu 

cross-line average limit proposed. 

Comment 14: Based on its experience 

with the low NOX burner at Minntac 

Line 6, EPA denied U.S. Steel’s Petition 

for Reconsideration (at another facility), 

explaining that after installing Line 6, 

U.S. Steel was able to make significant 

design changes before installation at the 

next line planned for BART installation, 

Minntac Line 7.16 EPA explained that 

the company identified the need for 

increased air flow and the need to 

modify the burner size or physical space 

to best accommodate the installation, 

and in doing so achieved the NOX

reductions at Line 7. EPA’s current 

proposal fails to explain why U.S. Steel 

cannot make design changes to all the 

lines that will be capable of burning 

natural gas to achieve the NOX emission 

limit when burning gas, when earlier it 

demonstrated it was able to do so at 

Lines 6 and 7. 

Response: U.S. Steel’s final burner 

reports for Lines 4 and 5, 6, and 7 

provide detailed explanations of its 

efforts to optimize NOX reduction at 

each line. As discussed in the reports, 

U.S. Steel has made physical and 

operational changes and tuned each low 

NOX burner to ensure each can operate 

in a manner that reduces NOX emissions 

while making pellets that meet quality 

specifications. Specifically, the 

September 2017 Line 4 final burner 

report highlights how U.S. Steel 

installed a blower to add additional 

combustion air to optimize 

stoichiometric ratios at Lines 4 and 5. 

Subsequent information provided by 

U.S. Steel discusses how U.S. Steel 

implemented a CEMS-based monitoring 

and process control program to monitor 

NOX emissions at each line and allow 

for automated process control system 

adjustments to ensure the low NOX

burners at each line are operating 

efficiently. 

Comment 15: One of EPA’s purported 

reasons for providing U.S. Steel with the 

higher limit is to provide the company 

with ‘‘additional flexibility.’’ This 

rationale finds no basis in the CAA and 

is therefore not a permissible reason for 

revising the 2013 FIP determinations. 

Moreover, while EPA suggests that this 

flexibility is appropriate because of 

‘‘unique issues U.S. Steel faced in trying 

to comply with the individual limits in 

the 2013 FIP,’’ EPA provides no 

explanation of what those issues are, 

and what options were explored, if any, 

to resolve those issues. EPA fails to 

provide an explanation for its reversal of 

opinion and fails to explain the basis for 

its decision. 

Response: As explained in the 

proposal, U.S. Steel faced issues trying 

to comply with the limits in the 2013 

FIP. As discussed in response to 

Comment 1, the emission limits initially 

promulgated under the 2013 FIP were 

based on the installation and 

optimization of low NOX burners on 

Lines 6 and 7, and the limited CEMS 

data available at that time. Since 

promulgation of the 2013 FIP, our 

understanding of the emissions levels 

achievable through the use of low NOX

burner has changed. U.S. Steel has 

continued to collect CEMS data from 

Lines 6 and 7. U.S. Steel has also 

installed low NOX burners on Lines 4 

and 5, adjusted and optimized each of 

those burners to reduce NOX, and 

collected CEMS data for each of the 

lines. 

EPA’s proposal to set an aggregate 

emission limit averaged across 

Minntac’s five lines is permissible 

under the BART Guidelines. As 

discussed in the proposal and in 

response to Comments 1 and 18, the 

BART Guidelines provide that a source 

may be permitted to ‘‘average’’ 

emissions across a set of BART-eligible 

emission units within a fenceline, so 

long as the emission reductions from 

each pollutant controlled for BART 

would be equal to those reductions that 

would be obtained by simply 

controlling each of the BART-eligible 

units that constitute BART-eligible 

sources. See 40 CFR part 51, appendix 

Y, at V. 

EPA based the 1.6 lbs NOX/MMBtu 

cross-line average on the emission rates 

demonstrated by the CEMS data to be 

achievable through the use of low NOX

burners. The 1.6 lbs NOX/MMBtu limit 

is the most stringent limit the facility 

can consistently meet while providing 

for operational flexibility with regard to 

fuel choice. As stated in the proposal, 

EPA is confident that allowing U.S. 

Steel to average NOX emissions levels 

across Minntac Lines 3 through 7 will 

achieve NOX emission reductions equal 

to the reductions that would have been 

obtained had EPA revised the 

individual limits for Minntac Lines 3 

through 7 separately. The ‘‘additional 

flexibility’’ provided by this cross-line 

average is consistent with the BART 

Guidelines. 

Comment 16: EPA does not disclose 

that the proposal is apparently the result 

of confidential settlement discussions. 

EPA’s apparent reliance on confidential 

information not disclosed as a part of 

this proposal, contravenes the Act’s 

requirements and does not allow the 

public to review and consider the 

changes proposed, and is particularly 

problematic in light of the history and 

level of pollution from these sources. 

EPA has not provided documentation of 

the reasons for the revisions in the form 

of publicly available information. 

Without the opportunity to review the 

information EPA relies on, the public is 

prohibited from critiquing the basis for 

EPA’s action and cannot meaningfully 

participate in the comment process. 

EPA is suppressing ‘‘meaningful 

comment by failure to disclose the basic 

data relied upon is akin to rejecting 

comment altogether.’’ 

In sum, EPA’s emission limitation 

proposal appears to be based on 

negotiations, rather than a technical 

analysis, since EPA did not consider the 


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relevant statutory and regulatory factors 

in proposing the revisions and fails to 

provide a basis for most of its assertions. 

It is unlawful, arbitrary and capricious 

for EPA to assert it has authority to 

revise BART emission limitations 

without the factual and analytical 

support substantiating its decision. 

Response: The revised emission limit 

is the result of a settlement agreement 

between EPA and U.S. Steel. On 

September 11, 2019, EPA published a 

notice of proposed settlement agreement 

in the Federal Register and provided 

the public an opportunity to comment 

on the proposed settlement agreement, 

in accordance with CAA section 113(g), 

42 U.S.C. 7413(g). (84 FR 47945). EPA 

did not receive any adverse comments 

relating to the proposed settlement 

agreement. Contrary to the commenter’s 

assertion, EPA did not rely on 

confidential information in determining 

the appropriate NOX BART emission 

limits for Minntac. Rather, EPA relied 

upon CEMS data available in the docket. 

As discussed in the response to 

Comment 1, the five-step BART analysis 

for Minntac in the August 15, 2012 

proposed FIP (77 FR 49312–49313), 

established low NOX burners as the 

basis for BART emission limits. That 

analysis and EPA’s determination that 

BART is based upon the use of low NOX

main burners remains valid and EPA 

continues to rely on the BART analysis 

set forth in the August 15, 2012 

proposal concerning the selection of low 

NOX burners as the appropriate BART 

technology. However, since EPA 

promulgated the FIP limits, U.S. Steel 

has continued to operate low NOX

burners and to collect CEMS data on 

Lines 6 and 7. Since promulgation of the 

FIP, U.S. Steel has also installed low 

NOX burners and collected CEMS data 

on Lines 4 and 5. Therefore, there are 

significantly more data available now 

from which to evaluate the emissions 

limits actually achievable through the 

use of low NOX burners at Minntac than 

there were at the time the FIP was 

promulgated. As discussed in greater 

detail in response to Comments 1 and 6, 

it is this combined data set, which has 

been included in the docket, that 

provides the basis for the revision to the 

NOX BART emission limit for Minntac. 

Comment 17: The proposal lacks 

clear, well-documented comparisons 

between baseline emissions, the 

emission limitations from the 2013 final 

Taconite FIPs, and the new proposal. In 

particular, changes in annual emissions 

are not provided, and thus not easily 

compared by the public. 

Response: Upon implementation of 

limits of 1.5 lbs NOX/MMBtu and 1.2 lbs 

NOX/MMBtu, the reductions estimated 

under the 2013 FIP for Minntac range 

from 5,426 tpy to 6,077 tpy. The 

estimated reductions under a revised 

Minntac limit of 1.6 lbs NOX/MMBtu 

are 5,209 tpy. These data are included 

in the docket as ‘‘Emission reduction 

estimates.’’ 

Comment 18: EPA fails to explain 

why it now thinks it is reasonable to use 

U.S. Steel’s averaging approach, which 

it earlier found was not defensible 

because it relies on the assumption that 

all furnaces will emit at their highest 

values. Relying on the assumption that 

all furnaces will emit at their highest 

values (and be burning natural gas 100 

percent of the time) is yet another 

assumption that provides an additional 

unjustified ‘‘safety margin.’’ 

Response: Under the BART 

Guidelines, a source may be permitted 

to ‘‘average’’ emissions across a set of 

BART-eligible emission units within a 

fenceline, so long as the emission 

reductions from each pollutant 

controlled for BART would be equal to 

those reductions that would be obtained 

by simply controlling each of the BARTeligible units that constitute BARTeligible sources. See 40 CFR part 51, 

appendix Y, at V. As shown in Table 1 

in response to Comment 1, averaging the 

individual limits across Lines 4 through 

7 results in a combined emissions limit 

of 1.6 lbs NOX/MMBtu averaged over 

720 hours (30 days). 

In determining the appropriate NOX

emission limit for Minntac, EPA 

analyzed CEMS data reflecting 720-hour 

rolling averages at the 95th and 99th 

percentiles as well as the highest 720- 

hour rolling average at each line. As 

noted in responses to Comments 1 and 

2, while the 1.6 lbs NOX/MMBtu limit 

for Minntac is reflective of natural gas 

emission data, EPA evaluated all 

available CEMS data for 2012–2017. 

Based on this CEMS data, the resulting 

cross-line average is 1.6 lbs NOX/ 

MMBtu averaged over 720 hours when 

the facility is burning natural gas, 

regardless of selection of statistical 

analyses at the 99th or 95th percentiles, 

or highest 720-hour average. As 

discussed in response to Comments 1 

and 13, 1.6 lbs NOX/MMBtu limit is the 

most stringent limit the facility can 

consistently meet while providing 

operational flexibility with regard to 

fuel choice, including the facility’s 

ability to burn natural gas as opposed to 

co-firing. EPA did not add a safety 

margin to the limit as commenter 

suggests. 

Comment 19: If EPA is already setting 

a 30-day rolling average limit, it is 

inappropriate to further use the 720- 

hour values. Introducing the hourly 

values provides additional variability in 

the limit. EPA provides no authority to 

justify this approach, which appears to 

have increased the BART limit. 

Response: Operations at Minntac in a 

given 30-day period, or even a single 

day, may in some cases involve both 

operation with only natural gas and 

operation with at least some firing of 

solid fuels. To be able to evaluate 

emissions from all hours when different 

fuels were used within a 30-day period, 

rather than only the times when a line 

used solely natural gas or solely co-fired 

for 30 consecutive days, EPA evaluated 

emissions based on 720-hour averages. 

Note that operations are typically 24 

hours per day and 720 is the number of 

hours in a 30-day period. 

Comment 20: 42 U.S.C. 7410(l) 

prohibits the Administrator from 

approving a SIP/FIP revision if the 

revisions would interfere with the 

attainment and reasonable further 

progress requirements of the CAA, and 

‘‘any other applicable requirement.’’ In 

addition to requiring BART, each state’s 

regional haze SIP must also set goals, 

expressed in deciviews for each Class I 

area located within the state that will 

assure reasonable progress toward 

achieving natural visibility. Moreover, 

the state’s haze SIP must establish 

reasonable progress goals that ensure 

visibility conditions steadily progress, 

providing for improvement in visibility 

on the most impaired days and ensure 

no degradation in visibility on the least 

impaired days over the period of the 

implementation plan. 40 CFR 

51.308(d)(1). These goals are set after 

considering the anticipated reductions 

in visibility impairing pollution over the 

planning period of the SIP from 

anticipated BART controls and other 

Federal or state programs, as well as 

controls imposed on non-BART sources 

under the regional haze SIP to help 

achieve reasonable progress. EPA’s 

proposal did not consider how relaxing 

the BART emission limits will impact 

the reasonable progress goals. 

Response: Under section 110(l) of the 

Act, 42 U.S.C. 7410(l), the EPA 

Administrator may not approve a SIP or 

FIP revision ‘‘if the revision would 

interfere with any applicable 

requirements concerning attainment and 

reasonable further progress, or any other 

applicable requirements of [the Act].’’ In 

the proposed action, EPA proposed to 

find that the revisions to the FIP will 

comply with applicable regional haze 

program requirements and general 

implementation plan requirements such 

as enforceability. 

On June 12, 2012 (77 FR 34801), EPA 

approved Minnesota’s regional haze 

plan as satisfying the applicable 

requirements in 40 CFR 51.308, except 


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17Minnesota; Revision to Taconite Federal 

Implementation Plan; October 14, 2020 Public 

Hearing Transcript, Docket ID # EPA–R05–OAR– 

2010–0037–0117, available at https://

www.regulations.gov/document?D=EPA-R05-OAR2010-0037-0117. 

18See emails from March 23, 2020 to June 30, 

2020 included in the docket as ‘‘3–23–2020 email 

from K. D’Agostino to D. Shepherd, T. Wickman, T. 

Allen,’’ etc. 

for BART emission limits for the 

taconite facilities. Among the regional 

haze plan elements approved was 

Minnesota’s long-term strategy for 

making reasonable progress toward 

visibility goals. Minnesota’s long-term 

strategy did not rely on the achievement 

of any particular degree of emission 

control from the taconite plants to 

achieve reasonable progress goals. 

Therefore, the revised NOX limits for 

Minntac represent greater control than 

was assumed in Minnesota’s approved 

long-term strategy SIP and does not 

interfere with the reasonable progress 

goals required by 40 CFR 51.308(d)(1). 

Thus, the proposed FIP revision would 

not interfere with any regional haze 

program requirements. 

Comment 21: The CAA requires that 

EPA provide a public hearing when 

proposing a FIP. [42 U.S.C. 7607(d)(5)] 

EPA failed to comply with this 

legislative mandate, since its proposal 

neither provided information regarding 

a public hearing, nor asked the public 

if they were interested in a hearing. 

Response: In response to this 

comment, EPA held a virtual public 

hearing on the proposed rule to provide 

interested persons an opportunity for 

the oral presentation of data, views, or 

arguments concerning the proposed 

rule. EPA also reopened the comment 

period on the proposed rule. 

Specifically, on September 29, 2020, 

EPA published a NPRM in the Federal 

Register announcing the virtual public 

hearing on the proposed rule to be held 

on October 14, 2020 and reopening the 

public comment period on the proposed 

rule. (85 FR 60942). EPA held the 

virtual public hearing on October 14, 

2020. EPA accepted public comments 

on the proposed rule for 30 days 

following the virtual public hearing, and 

the public comment period closed on 

November 13, 2020. No individuals 

presented at the virtual public hearing 

and EPA did not receive any comments 

during the reopened comment period. 

The docket has been updated with a 

transcript of the virtual public 

hearing.17

Comment 22: The CAA and Regional 

Haze Rule grant the FLMs, regardless of 

whether a FLM manages a Class I area 

within or beyond the state, a special role 

in the review of regional haze 

implementation plans. There are 

obligations to consult on plan revisions 

under 40 CFR 51.308(i)(3) and EPA has 

not demonstrated it consulted with the 

Forest Service, the Fish and Wildlife 

Service and the National Park Service 

on the proposed FIP revision. Therefore, 

EPA has not met its obligations under 

the Act. 

Response: In response to this 

comment, EPA contacted the FLMs to 

provide the FLMs an opportunity to 

consult on the proposed action. EPA 

reached out to representatives from the 

National Park Service, U.S. Forest 

Service, and U.S. Fish and Wildlife 

Service. Each representative indicated 

that they did not have any comments on 

the proposed rule. EPA has updated the 

docket to include the relevant 

communications with the FLMs.18

Comment 23: Should EPA wish to 

pursue this FIP revision, the agency 

must prepare the required information 

and analyses, including a 

comprehensive optimization study at 

Minntac, and then repropose its action. 

Response: As noted in responses to 

Comments 1, 9 and 16, the five-step 

BART analysis for Minntac in the 

August 15, 2012 proposed FIP (77 FR 

49312–49313), established low NOX

burners as the basis for BART emission 

limits. That analysis and EPA’s 

determination that BART is based upon 

the use of low NOX main burners 

remains valid and EPA continues to rely 

on the BART analysis set forth in the 

August 15, 2012 proposal concerning 

the selection of low NOX burners as the 

appropriate BART technology. However, 

since EPA promulgated the FIP limits, 

U.S. Steel has continued to operate low 

NOX burners and to collect CEMS data 

on Lines 6 and 7. Since promulgation of 

the FIP, U.S. Steel has also installed low 

NOX burners and collected CEMS data 

on Lines 4 and 5. Therefore, there are 

significantly more data available now 

from which to evaluate the emissions 

limits actually achievable through the 

use of low NOX burners at Minntac than 

there were at the time the FIP was 

promulgated. As discussed in greater 

detail in response to Comments 1 and 6, 

it is this combined data set, which has 

been included in the docket, that 

provides the basis for the revision to the 

NOX BART emission limit for Minntac. 

In addition, as described in greater 

detail in responses to Comments 9 and 

14, U.S. Steel’s final burner reports for 

Lines 4 and 5, 6, and 7 provide detailed 

explanations of its efforts to optimize 

NOX reduction at each line. As 

discussed in the reports, U.S. Steel has 

made physical and operational changes 

and tuned each low NOX burner to 

ensure each can operate in a manner 

that reduces NOX emissions while 

making pellets that meet quality 

specifications. In each report, U.S. Steel 

discusses the process of optimizing the 

low NOX burners and tuning each 

burner and ancillary equipment to 

achieve optimal stoichiometric air to 

fuel ratios. For each line, U.S. Steel 

determined achieving optimal air to fuel 

ratios requires monitoring the atomizing 

air and gas split between the core and 

annulus gas to reduce flame turbulence 

in order to create a tight flame shape at 

each burner. In addition, in some cases, 

U.S. Steel modified capacities of 

combustion fans and added blowers and 

annulus rings to improve thrust and air 

to fuel ratios—each of which served to 

minimize NOX emissions as 

demonstrated by CEMS data. 

This action is limited to revising the 

FIP emission limit for Minntac to reflect 

the level of NOX control achievable for 

the source based on the use of low NOX

burners. Regarding commenter’s 

assertion that EPA was required to 

prepare certain information and analysis 

and repropose this action, as noted 

above, at the time of our February 4, 

2020 proposal, EPA already had the 

information and analyses necessary to 

determine the appropriate revised 

emission limit for Minntac. This 

information included CEMS data for 

Minntac Lines 4 through 7 provided by 

U.S. Steel and EPA’s analysis of that 

information. In addition, U.S. Steel 

provided to EPA final burner reports 

detailing U.S. Steel’s efforts to optimize 

the low NOX burners on Minntac Lines 

4 through 7. 

As discussed in response to Comment 

1, in the 2013 FIP, EPA determined that 

low NOX burners reflect the appropriate 

level of BART control for Minntac. 

EPA’s analysis and proposed 

determination that BART is based upon 

the use of low NOX burners remains 

valid. (78 FR 8706). However, the 

emission limits established in the 2013 

FIP were based on limited CEMS data. 

Since promulgation of the 2013 FIP, 

U.S. Steel has continued to collect 

CEMS data on Minntac Lines 6 and 7. 

U.S. Steel has also installed low NOX

burners on Lines 4 and 5 and has 

collected CEMS data reflecting the 

operation of low NOX burners on these 

lines. To determine emission rates that 

would be consistently achievable at 

each line, EPA evaluated all available 

CEMS data for 2012–2017, which 

covered a wide range of different 

operating scenarios. 

Comment 24: How is the increase in 

NOX emissions at this source not 

affecting nonattainment areas in 

downwind states such as New York or 


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Connecticut? East coast states typically 

point to states like Minnesota as 

significantly contributing to their ozone 

problems under CAA 110(a)(2)(D). Is 

EPA at this point conclusively deciding 

that this increased FIP limit will not 

cause the state to violate CAA 

110(a)(2)(D) for any of the relevant 

NAAQS like ozone PM or NO2? Did 

EPA adjust its photochemical modeling 

performed for good neighbor SIPs to 

account for this relaxation? EPA issued 

several memos detailing Minnesota’s 

contributions before this change, what is 

the quantitative effect of increasing 

these emissions on Minnesota’s 

contribution to downwind states? EPA 

must figure this out before modifying 

this FIP otherwise EPA is 

predetermining Minnesota’s SIP under 

110(a)(2)(D) and concluding the state 

has met its obligations. 

Response: The CAA requires states to 

submit, within three years after 

promulgation of a new or revised 

standard, SIPs meeting the applicable 

‘‘infrastructure’’ elements of sections 

110(a)(1) and (2). One of these 

applicable infrastructure elements, CAA 

section 110(a)(2)(D)(i), requires SIPs to 

contain ‘‘good neighbor’’ provisions to 

prohibit certain adverse air quality 

effects on neighboring states due to 

interstate transport of pollution. The 

commenter does not specify which 

element of CAA section 110(a)(2)(D) it 

believes is implicated by this action. 

Though, in questioning the effect of the 

FIP revision on downwind 

nonattainment areas, the commenter 

may be referring to the first two subelements of the good neighbor 

provisions, at CAA section 

110(a)(2)(D)(i)(I). These sub-elements 

require that each SIP for a new or 

revised standard contain adequate 

provisions to prohibit any source or 

other type of emissions activity within 

the state from emitting air pollutants 

that will ‘‘contribute significantly to 

nonattainment’’ or ‘‘interfere with 

maintenance’’ of the applicable air 

quality standard in any other state. 

EPA has previously taken action to 

approve good neighbor SIPs for several 

pollutants and the modifications being 

made to the FIP are not expected to 

contradict those approvals. On October 

20, 2015 (80 FR 63436), EPA approved 

Minnesota’s SIP as addressing the 

State’s CAA section 110(a)(2)(D)(i)(I) 

obligations under the 2010 NO2

NAAQS. The approval of Minnesota’s 

2010 NO2 good neighbor SIP was based 

on low design values for Minnesota and 

surrounding states, with the highest 

neighboring state showing a design 

value of 49 parts per billion (ppb), less 

than half of the 100 ppb standard. This 

approval was based on monitoring data 

from 2011 to 2013. Therefore, the FIP, 

promulgated in 2013, but not 

immediately requiring reductions, 

would not have had an impact on that 

data set. 

On October 10, 2018 (83 FR 50849), 

EPA approved Minnesota’s SIP as 

addressing the State’s CAA section 

110(a)(2)(D)(i)(I) obligations under the 

2012 PM2.5 NAAQS. In the proposed SIP 

approval, EPA explained that Minnesota 

found, and EPA’s review confirmed, 

that all areas in other states where 

Minnesota emissions had the potential 

to impact monitored PM2.5 air quality, 

with the exception of one monitor in 

Allegheny County, Pennsylvania, were 

attaining the 2012 annual PM2.5 NAAQS 

based on 2014–2016 data. (83 FR 39970, 

August 13, 2018). The emissions limits 

promulgated in the 2013 FIP were not 

yet in effect during this period, and thus 

the associated reductions did not impact 

the EPA’s assessment of attainment. 

Minnesota further determined that its 

impact on air quality monitors in 

Pennsylvania was projected to be less 

than 1% of the 2012 annual PM2.5

NAAQS, an insignificant contribution 

based on the air quality threshold that 

EPA had previously used to identify 

linkages between upwind states and 

downwind air quality problems under 

CAA section 110(a)(2)(D)(i)(I). 

Minnesota’s determination was based 

on EPA’s source apportionment 

modeling projecting upwind state 

contributions to downwind monitors 

using 2011 base case emissions, which 

was also conducted prior to the 

effectiveness of the emission limits 

promulgated in the 2013 FIP. The 

revised FIP limit at Minntac represents 

greater control than was assumed in 

Minnesota’s and EPA’s analysis 

supporting approval of the 2012 PM2.5

good neighbor SIP. 

To the extent EPA has not acted on a 

pending good neighbor SIP under CAA 

section 110(a)(2)(D)(i)(I), EPA is not in 

this action pre-determining its 

approvability. On October 1, 2018, the 

State of Minnesota submitted to EPA a 

SIP submittal addressing Minnesota’s 

interstate transport requirements under 

CAA section 110(a)(2)(D)(i)(I) with 

respect to the 2015 ozone NAAQS. EPA 

has not yet taken action on Minnesota’s 

October 1, 2018 SIP submittal. We will 

consider emissions from the state and 

whether the state is significantly 

contributing to or interfering with 

maintenance of the 2015 ozone NAAQS 

in any other state when we take action 

on the SIP. 

III. Final Action 

For the reasons stated in the proposed 

FIP revision, EPA is finalizing the 

revised BART emission limit and 

related requirements for the U.S. Steel 

Minntac facility as proposed. 

IV. Statutory and Executive Order 

Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

This action is exempt from review by 

the Office of Management and Budget 

(OMB) because it is a rule of particular 

applicability and only affects one 

facility, U.S. Steel’s Minntac taconite 

plant located in Mt. Iron, Minnesota. 

B. Executive Order 13771: Reducing 

Regulations and Controlling Regulatory 

Costs 

This action is not an Executive Order 

13771 regulatory action because this 

action is not significant under Executive 

Order 12866. 

C. Paperwork Reduction Act (PRA) 

This action does not impose an 

information collection burden under the 

provisions of the PRA, 44 U.S.C. 3501 

et seq. Under the Paperwork Reduction 

Act, a ‘‘collection of information’’ is 

defined as a requirement for ‘‘answers to 

. . . identical reporting or 

recordkeeping requirements imposed on 

ten or more persons . . . .’’ 44 U.S.C. 

3502(3)(A). Because the FIP applies to 

just one facility, the PRA does not 

apply. See 5 CFR 1320(c). 

D. Regulatory Flexibility Act (RFA) 

After considering the economic 

impacts of this action on small entities, 

I certify that this action will not have a 

significant economic impact on a 

substantial number of small entities. 

EPA’s action revises control 

requirements at one source. The 

Regional Haze FIP that EPA is 

promulgating for purposes of the 

regional haze program consists of 

imposing Federal control requirements 

to meet the BART requirement for NOX

emissions on specific units at one 

source in Minnesota. The net result of 

the FIP action is that EPA is finalizing 

emission controls on the indurating 

furnaces at one taconite facilities and 

this source is not owned by small 

entities, and therefore is not a small 

entity. 

E. Unfunded Mandates Reform Act 

(UMRA) 

EPA has determined that this rule 

does not contain a Federal mandate as 


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described in UMRA, 2 U.S.C. 1531– 

1538, that may result in expenditures 

that exceed the inflation-adjusted 

UMRA threshold of $100 million by 

State, local, or Tribal governments or 

the private sector in any one year. In 

addition, this rule does not contain a 

significant Federal intergovernmental 

mandate as described by section 203 of 

UMRA nor does it contain any 

regulatory requirements that might 

significantly or uniquely affect small 

governments. 

F. Executive Order 13132: Federalism 

This action does not have federalism 

implications. It will not have substantial 

direct effects on the states, on the 

relationship between the national 

government and the states, or on the 

distribution of power and 

responsibilities among the various 

levels of government. 

G. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

This rule does not have tribal 

implications, as specified in Executive 

Order 13175. Thus, Executive Order 

13175 does not apply to this rule. 

However, EPA did discuss this action in 

conference calls with the Minnesota 

Tribes. 

H. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

EPA interprets E.O. 13045 as applying 

only to those regulatory actions that 

concern health or safety risks, such that 

the analysis required under section 5– 

501 of the E.O. has the potential to 

influence the regulation. This action is 

not subject to E.O. 13045 because it does 

not establish an environmental standard 

intended to mitigate health or safety 

risks. This action addresses regional 

haze and visibility protection. Further, 

because this amendment to the current 

regulation will require controls that will 

cost an amount equal to or less than the 

cost of controls required under the 

current regulation, it is not an 

economically significant regulatory 

action. However, to the extent this rule 

will limit emissions of NOX, SO2, and 

PM, the rule will have a beneficial effect 

on children’s health by reducing air 

pollution. 

I. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This action is not subject to Executive 

Order 13211, because it is not a 

significant regulatory action under 

Executive Order 12866. 

J. National Technology Transfer and 

Advancement Act 

Section 12 of the National Technology 

Transfer and Advancement Act 

(NTTAA) of 1995 requires Federal 

agencies to evaluate existing technical 

standards when developing a new 

regulation. To comply with NTTAA, 

EPA must consider and use ‘‘voluntary 

consensus standards’’ (VCS) if available 

and applicable when developing 

programs and policies unless doing so 

would be inconsistent with applicable 

law or otherwise impractical. 

VCS are inapplicable to this action 

because application of those 

requirements would be inconsistent 

with the CAA. 

K. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations 

We have determined that this rule 

will not have disproportionately high 

and adverse human health or 

environmental effects on minority or 

low-income populations, as specified in 

Executive Order 12898 (59 FR 7629, 

February 16, 1994), because it increases 

the level of environmental protection for 

all affected populations without having 

any disproportionately high and adverse 

human health or environmental effects 

on any population, including any 

minority or low-income population. 

L. Congressional Review Act (CRA) 

This rule is exempt from the CRA 

because it is a rule of particular 

applicability. 

M. Determination Under Section 307(d) 

Pursuant to CAA section 307(d)(1)(B), 

this action is subject to the requirements 

of CAA section 307(d), as it revises a FIP 

under CAA section 110(c). 

N. Judicial Review 

Under section 307(b)(1) of the CAA, 

petitions for judicial review of this 

action must be filed in the United States 

Court of Appeals for the appropriate 

circuit by May 3, 2021. Filing a petition 

for reconsideration by the Administrator 

of this final rule does not affect the 

finality of this action for the purposes of 

judicial review nor does it extend the 

time within which a petition for judicial 

review may be filed, and shall not 

postpone the effectiveness of such rule 

or action. This action may not be 

challenged later in proceedings to 

enforce its requirements. See CAA 

section 307(b)(2). 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Incorporation by 

reference, Intergovernmental relations, 

Nitrogen dioxide, Particulate matter, 

Regional haze, Reporting and 

recordkeeping requirements, Sulfur 

oxides, Volatile organic compounds. 

This document of the Environmental 

Protection Agency was signed on 

January 11, 2021, by Andrew Wheeler, 

Administrator, pursuant to a settlement 

agreement between EPA and U.S. Steel 

that required the final rule to be signed 

no later than January 20, 2021. That 

document with the original signature 

and date is maintained by EPA. For 

administrative purposes only, and in 

compliance with requirements of the 

Office of the Federal Register, the 

undersigned EPA Official re-signs the 

document for publication, as an official 

document of the Environmental 

Protection Agency. This administrative 

process in no way alters the legal effect 

of this document upon publication in 

the Federal Register. 

Jane Nishida, 

Acting Administrator. 

For the reasons stated in the 

preamble, EPA amends title 40 CFR part 

52 as follows: 

PART 52—APPROVAL AND 

PROMULGATION OF 

IMPLEMENTATION PLANS 

■ 1. The authority citation for part 52 

continues to read as follows: 

Authority: 42 U.S.C. 7401 et seq. 

■ 2. In § 52.1235 revise paragraph 

(b)(1)(iii) to read as follows: 

§ 52.1235 Regional haze. 

* * * * * 

(b)(1) * * * 

(iii) United States Steel Corporation, 

Minntac: An aggregate emission limit of 

1.6 lbs NOX/MMBtu, based on a 30-day 

rolling average, shall apply to the 

combined NOX emissions from the five 

indurating furnaces: Line 3 (EU225), 

Line 4 (EU261), Line 5 (EU282), Line 6 

(EU315), and Line 7 (EU334). To 

determine the aggregate emission rate, 

the combined NOX emissions from lines 

3, 4, 5, 6 and 7 shall be divided by the 

total heat input to the five lines (in 

MMBTU) during every rolling 30-day 

period commencing either upon 

notification of a starting date by United 

States Steel Corporation, Minntac, or 

with the 30-day period from September 

1, 2019 to September 30, 2019, 

whichever occurs first. The aggregate 

emission rate shall subsequently be 

determined on each day, 30 days after 

the starting date contained in such 


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Federal Register / Vol. 86, No. 39 / Tuesday, March 2, 2021 / Rules and Regulations 12107 

notification or September 30, 2019, 

whichever occurs first. 

* * * * * 

[FR Doc. 2021–04108 Filed 3–1–21; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Parts 52 and 81 

[EPA–R05–OAR–2018–0732; FRL–10020– 

70–Region 5] 

Designation of Areas for Air Quality 

Planning Purposes; Indiana; 

Redesignation of the Southwest 

Indiana Sulfur Dioxide Nonattainment 

Area 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: In accordance with the Clean 

Air Act (CAA), the Environmental 

Protection Agency (EPA) is 

redesignating the Southwest Indiana 

nonattainment area, which consists of a 

portion of Daviess County and a portion 

of Pike County (Veale Township in 

Daviess County and Washington 

Township in Pike County), to 

attainment for the 2010 primary, healthbased 1-hour sulfur dioxide (SO2) 

National Ambient Air Quality Standard 

(NAAQS). EPA is also approving 

Indiana’s maintenance plan for the 

Southwest Indiana SO2 nonattainment 

area. Indiana submitted the request for 

approval of the Southwest Indiana 

nonattainment area’s redesignation and 

maintenance plan on October 24, 2018, 

and supplemental information on 

August 25, 2020. EPA has previously 

approved Indiana’s attainment plan for 

the Southwest Indiana area. 

DATES: This final rule is effective on 

April 30, 2021. 

ADDRESSES: EPA has established a 

docket for this action under Docket ID 

No. EPA–R05–OAR–2018–0732. All 

documents in the docket are listed on 

the www.regulations.gov website. 

Although listed in the index, some 

information is not publicly available, 

i.e., Confidential Business Information 

(CBI) or other information whose 

disclosure is restricted by statute. 

Certain other material, such as 

copyrighted material, is not placed on 

the internet and will be publicly 

available only in hard copy form. 

Publicly available docket materials are 

available either through 

www.regulations.gov or at the 

Environmental Protection Agency, 

Region 5, Air and Radiation Division, 77 

West Jackson Boulevard, Chicago, 

Illinois 60604. This facility is open from 

8:30 a.m. to 4:30 p.m., Monday through 

Friday, excluding Federal holidays and 

facility closures due to COVID–19. We 

recommend that you telephone Abigail 

Teener, Environmental Engineer, at 

(312) 353–7314 before visiting the 

Region 5 office. 

FOR FURTHER INFORMATION CONTACT: 

Abigail Teener, Environmental 

Engineer, Attainment Planning and 

Maintenance Section, Air Programs 

Branch (AR–18J), U.S. Environmental 

Protection Agency, Region 5, 77 West 

Jackson Boulevard, Chicago, Illinois 

60604, (312) 353–7314, teener.abigail@

epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. Background Information 

On October 29, 2020, EPA proposed 

to approve the redesignation of the 

Southwest Indiana SO2 nonattainment 

area to attainment of the 2010 primary, 

health-based 1-hour SO2 NAAQS and to 

approve Indiana’s maintenance plan for 

the nonattainment area (85 FR 68533). 

An explanation of the CAA 

requirements, a detailed analysis of the 

revisions, and EPA’s reasons for 

proposing approval were provided in 

the notice of proposed rulemaking and 

will not be restated here. The public 

comment period for this proposed rule 

ended on November 30, 2020. EPA 

received no comments on the proposal. 

II. Final Action 

In accordance with Indiana’s October 

24, 2018 request and August 25, 2020 

supplemental letter, EPA is 

redesignating the Southwest Indiana 

nonattainment area from nonattainment 

to attainment of the 2010 SO2 NAAQS. 

EPA finds that Indiana has 

demonstrated that the area is attaining 

the 2010 SO2 NAAQS and that the 

improvement in air quality is due to 

permanent and enforceable SO2

emission reductions in the area. EPA is 

also approving Indiana’s maintenance 

plan, which is designed to ensure that 

the area will continue to maintain the 

SO2 NAAQS. 

III. Statutory and Executive Order 

Reviews 

Under the CAA, redesignation of an 

area to attainment and the 

accompanying approval of a 

maintenance plan under section 

107(d)(3)(E) are actions that affect the 

status of a geographical area and do not 

impose any additional regulatory 

requirements on sources beyond those 

imposed by state law. A redesignation to 

attainment does not in and of itself 

create any new requirements, but rather 

results in the applicability of 

requirements contained in the CAA for 

areas that have been redesignated to 

attainment. Moreover, the Administrator 

is required to approve a SIP submission 

that complies with the provisions of the 

CAA and applicable Federal regulations. 

42 U.S.C. 7410(k); 40 CFR 52.02(a). 

Thus, in reviewing SIP submissions, 

EPA’s role is to approve state choices, 

provided that they meet the criteria of 

the CAA. Accordingly, this action 

merely approves state law as meeting 

Federal requirements and does not 

impose additional requirements beyond 

those imposed by state law. For that 

reason, this action: 

• Is not a significant regulatory action 

subject to review by the Office of 

Management and Budget under 

Executive Orders 12866 (58 FR 51735, 

October 4, 1993) and 13563 (76 FR 3821, 

January 21, 2011); 

• Is not an Executive Order 13771 (82 

FR 9339, February 2, 2017) regulatory 

action because it is not a significant 

regulatory action under Executive Order 

12866; 

• Does not impose an information 

collection burden under the provisions 

of the Paperwork Reduction Act (44 

U.S.C. 3501 et seq.); 

• Is certified as not having a 

significant economic impact on a 

substantial number of small entities 

under the Regulatory Flexibility Act (5 

U.S.C. 601 et seq.); 

• Does not contain any unfunded 

mandate or significantly or uniquely 

affect small governments, as described 

in the Unfunded Mandates Reform Act 

of 1995 (Pub. L. 104–4); 

• Does not have federalism 

implications as specified in Executive 

Order 13132 (64 FR 43255, August 10, 

1999); 

• Is not an economically significant 

regulatory action based on health or 

safety risks subject to Executive Order 

13045 (62 FR 19885, April 23, 1997); 

• Is not a significant regulatory action 

subject to Executive Order 13211 (66 FR 

28355, May 22, 2001); 

• Is not subject to requirements of 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (15 U.S.C. 272 note) because 

application of those requirements would 

be inconsistent with the CAA; and 

• Does not provide EPA with the 

discretionary authority to address, as 

appropriate, disproportionate human 

health or environmental effects, using 

practicable and legally permissible 

methods, under Executive Order 12898 

(59 FR 7629, February 16, 1994). 

In addition, the SIP is not approved 

to apply on any Indian reservation land 

or in any other area where EPA or an 


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