96152 Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 

and expertise in the conservation of 

cultural or natural heritage, as those 

terms are defined in Articles 1 and 2 of 

the Convention, may be requested to 

participate in the Panel from time to 

time. 

(3) The Assistant Secretary chairs 

meetings of the Panel, and sets its 

agenda and schedule. The NPS provides 

staff support to the Panel. 

■ 8. Amend § 73.13 by: 

■ a. Revising paragraphs (a) and (c); and 

■ b. Removing the undesignated 

paragraph at the end of the section. 

The revisions read as follows: 

§ 73.13 Protection of U.S. World Heritage 

properties. 

(a) Requirements. (1) Article 5 of the 

Convention, as required in more detail 

in the Operational Guidelines, mandates 

that each participating nation shall take, 

insofar as possible, the appropriate 

legal, scientific, technical, 

administrative, and financial measures 

necessary for the identification, 

protection, conservation, preservation, 

and rehabilitation of properties of 

outstanding universal value. This is a 

government-wide obligation. 

(2) The nomination document for a 

property must include evidence of such 

legal protections as may be necessary to 

ensure preservation of the property and 

its environment, including, for example, 

restrictive covenants, easements, or 

other forms of protection (54 U.S.C. 

307101(c)). 

* * * * * 

(c) Protection Measures for Private 

Properties. For properties owned by 

private organizations or individuals, the 

protection measures for each property 

being considered for possible 

nomination to the World Heritage List 

will be reviewed by the Assistant 

Secretary on a case-by-case basis to 

ensure that they fulfill the mandate of 

54 U.S.C. 307101(c), giving 

consideration to what would constitute 

effective protection that is appropriate 

to the circumstances of the particular 

property. Such considerations may 

include the current and potential use of 

the property, the nature of its 

ownership, and the effectiveness of the 

applicable legal protection measures. 

(1) One or more of the following items 

may satisfy the protection requirements 

outlined in paragraph (a) of this section, 

if the Assistant Secretary determines 

that they sufficiently prohibit any use or 

physical alteration that is not consistent 

with, or which threatens or damages the 

property’s universally significant value: 

(i) Written covenant executed by the 

owner(s); or 

(ii) Other trust or legal arrangement, 

such as an easement or substantive 

protection under a local historic 

preservation ordinance. 

(2) [Reserved] 

§ 73.17 [Amended] 

■ 9. Amend § 73.17, in paragraph (c), by 

removing the text ‘‘slideshows,’’. 

Shannon A. Estenoz, 

Assistant Secretary for Fish and Wildlife and 

Parks. 

[FR Doc. 2024–27373 Filed 12–3–24; 8:45 am] 

BILLING CODE 4312–52–P 

DEPARTMENT OF COMMERCE 

Patent and Trademark Office 

37 CFR Part 1 

[Docket No. PTO–P–2024–0003] 

RIN 0651–AD76 

Terminal Disclaimer Practice To 

Obviate Nonstatutory Double 

Patenting; Withdrawal 

AGENCY: United States Patent and 

Trademark Office, Department of 

Commerce. 

ACTION: Proposed rule; withdrawal. 

SUMMARY: The USPTO is withdrawing 

the Notice of Proposed Rulemaking 

(NPRM) published in the Federal 

Register on May 10, 2024, that proposes 

to add a new requirement for an 

acceptable terminal disclaimer filed to 

obviate (that is, overcome) nonstatutory 

double patenting. 

DATES: The proposed rule published at 

89 FR 40439 on May 10, 2024, is 

withdrawn as of December 4, 2024. 

FOR FURTHER INFORMATION CONTACT: 

Susy Tsang-Foster, Senior Legal 

Advisor, Office of Patent Legal 

Administration, at 571–272–7711; or 

Nicholas Hill, Legal Advisor, Office of 

Patent Legal Administration, at 571– 

270–1485. 

SUPPLEMENTARY INFORMATION: This 

action withdraws a proposed rule 

published in the Federal Register on 

May 10, 2024 (89 FR 40439), to add a 

new requirement for an acceptable 

terminal disclaimer that is filed to 

obviate (that is, overcome) nonstatutory 

double patenting. The proposed rule’s 

comment period was open from May 10, 

2024, to July 9, 2024. 

Reason for Withdrawal 

During the proposed rule’s 60-day 

comment period, the USPTO received 

more than 300 comments from a variety 

of stakeholders, including commenters 

both supporting and opposing the 

proposal. The comments are publicly 

available at the Federal eRulemaking 

Portal at www.regulations.gov/ 

document/PTO-P-2024-0003-0001. Of 

the comments received on the proposed 

rule, 256 comments were unique. 

In light of resource constraints, the 

USPTO has decided not to move 

forward with the proposed rule at this 

time and to withdraw the proposed rule. 

Despite the decision not to move 

forward with the proposed rule at this 

time, the USPTO appreciates and takes 

seriously the thoughtful perspectives 

raised by commenters. The USPTO will 

continue engaging with its stakeholders 

as it works to foster a balanced, robust, 

and reliable intellectual property 

system. 

Conclusion 

The proposed rule to add a new 

requirement for an acceptable terminal 

disclaimer that is filed to obviate 

nonstatutory double patenting, 

published in the Federal Register on 

May 10, 2024 (89 FR 40439), is hereby 

withdrawn. 

Katherine K. Vidal, 

Under Secretary of Commerce for Intellectual 

Property and Director of the United States 

Patent and Trademark Office. 

[FR Doc. 2024–28263 Filed 12–3–24; 8:45 am] 

BILLING CODE 3510–16–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R05–OAR–2024–0215; FRL–12351– 

01–R5] 

Air Plan Approval; Michigan and 

Minnesota; Revision to Taconite 

Federal Implementation Plan 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is proposing to finalize 

nitrogen oxide (NOX) and/or sulfur 

dioxide (SO2) limits for the indurating 

furnaces at five taconite facilities in 

accordance with the procedures set 

forth in the Federal implementation 

plan (FIP) addressing the requirement 

for best available retrofit technology 

(BART) at taconite facilities. EPA is also 

proposing to modify the Upper 

Predictive Limit (UPL) equations used 

to establish NOX and SO2 emission 

limits under the FIP. Finally, EPA is 

proposing to revise reporting provisions 

to require reports to be submitted to 

EPA electronically. EPA is proposing 

these actions pursuant to sections 110 

and 169A of the Clean Air Act (CAA). 


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1Areas designated as mandatory Class I Federal 

areas consist of national parks exceeding 6000 

acres, wilderness areas and national memorial parks 

exceeding 5000 acres, and all international parks 

that were in existence on August 7, 1977. 42 U.S.C. 

7472(a). In accordance with section 169A of the 

CAA, EPA, in consultation with the Department of 

Interior, promulgated a list of 156 areas where 

visibility is identified as an important value. 44 FR 

69122 (November 30, 1979). The extent of a 

mandatory Class I area includes subsequent changes 

in boundaries, such as park expansions. 42 U.S.C. 

7472(a). Although states and Tribes may designate 

as Class I additional areas which they consider to 

have visibility as an important value, the 

requirements of the visibility program set forth in 

section 169A of the CAA apply only to ‘‘mandatory 

Class I Federal areas.’’ Each mandatory Class I 

Federal area is the responsibility of a ‘‘Federal Land 

Manager.’’ 42 U.S.C. 7602(i). When we use the term 

‘‘Class I area’’ in this action, we mean a ‘‘mandatory 

Class I Federal area.’’ 

DATES: Comments must be received on 

or before January 21, 2025. 

Virtual Public Hearing. EPA will hold 

a virtual public hearing to solicit 

comments on December 19, 2024. The 

last day to pre-register to present at the 

hearing will be December 16, 2024. On 

December 16, 2024, EPA will post a 

general agenda for the hearing that will 

list pre-registered presenters in 

approximate order at https://

www.epa.gov/mn/revision-taconiteregional-haze-federal-implementationplan-mi-and-mn. If you require the 

services of a translator or a special 

accommodation such as audio 

description/closed captioning, please 

pre-register for the hearing and describe 

your needs by December 11, 2024. 

For more information on the virtual 

public hearing, see SUPPLEMENTARY

INFORMATION. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R05– 

OAR–2024–0215 at https://

www.regulations.gov, or via email to 

arra.sarah@epa.gov. For comments 

submitted at Regulations.gov, follow the 

online instructions for submitting 

comments. Once submitted, comments 

cannot be edited or removed from the 

docket. EPA may publish any comment 

received to its public docket. Do not 

submit to EPA’s docket at https://

www.regulations.gov any information 

you consider to be Confidential 

Business Information (CBI), Proprietary 

Business Information (PBI), or other 

information whose disclosure is 

restricted by statute. Multimedia 

submissions (audio, video, etc.) must be 

accompanied by a written comment. 

The written comment is considered the 

official comment and should include 

discussion of all points you wish to 

make. EPA will generally not consider 

comments or comment contents located 

outside of the primary submission (i.e. 

on the web, cloud, or other file sharing 

system). For additional submission 

methods, please contact the person 

identified in the FOR FURTHER

INFORMATION CONTACT section. For the 

full EPA public comment policy, 

information about CBI, PBI, or 

multimedia submissions, and general 

guidance on making effective 

comments, please visit https://

www.epa.gov/dockets/commenting-epadockets. 

FOR FURTHER INFORMATION CONTACT: 

Kathleen D’Agostino, Environmental 

Scientist, Air and Radiation Division 

(AR18J), Environmental Protection 

Agency, Region 5, 77 West Jackson 

Boulevard, Chicago, Illinois 60604, 

(312) 886–0266, dagostino.kathleen@

epa.gov. The EPA Region 5 office is 

open from 8:30 a.m. to 4:30 p.m., 

Monday through Friday, excluding 

Federal holidays. 

SUPPLEMENTARY INFORMATION: 

Throughout this document whenever 

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

EPA. 

Virtual Public Hearing 

EPA is holding a virtual public 

hearing to provide interested parties the 

opportunity to present data, views, or 

arguments concerning the proposal. 

EPA will hold a virtual public hearing 

to solicit comments on December 19, 

2024. The hearing will convene at 9:00 

a.m. Central Standard Time (CST) and 

will conclude at 1:00 p.m. CST, or 15 

minutes after the last pre-registered 

presenter in attendance has presented if 

there are no additional presenters. EPA 

will announce further details, including 

information on how to register for the 

virtual public hearing, on the virtual 

public hearing website at https://

www.epa.gov/mn/revision-taconiteregional-haze-federal-implementationplan-mi-and-mn. 

EPA will begin pre-registering 

presenters and attendees for the hearing 

upon publication of this document in 

the Federal Register. To pre-register to 

attend or present at the virtual public 

hearing, please use the online 

registration form available at https://

www.epa.gov/mn/revision-taconiteregional-haze-federal-implementationplan-mi-and-mn or contact Mayesha 

Choudhury at 312–886–5909 or by 

email at choudhury.mayesha@epa.gov. 

The last day to pre-register to present at 

the hearing will be December 16, 2024. 

On December 16, 2024, EPA will post a 

general agenda for the hearing that will 

list pre-registered presenters in 

approximate order at https://

www.epa.gov/mn/revision-taconiteregional-haze-federal-implementationplan-mi-and-mn. Additionally, requests 

to present will be taken on the day of 

the hearing as time allows. 

EPA will make every effort to follow 

the schedule as closely as possible on 

the day of the hearing; however, please 

plan for the hearing to run either ahead 

of schedule or behind schedule. Each 

commenter will have 5 minutes to 

provide oral testimony. EPA encourages 

commenters to provide EPA with a copy 

of their oral testimony electronically by 

including it in the registration form or 

emailing it to choudhury.mayesha@

epa.gov. EPA may ask clarifying 

questions during the oral presentations 

but will not respond to the 

presentations at that time. Written 

statements and supporting information 

submitted during the comment period 

will be considered with the same weight 

as oral comments and supporting 

information presented at the virtual 

public hearing. 

EPA is asking all hearing attendees to 

pre-register, even those who do not 

intend to present. This will help EPA 

prepare for the virtual hearing. 

Please note that any updates made to 

any aspect of the hearing will be posted 

online at https://www.epa.gov/mn/ 

revision-taconite-regional-haze-federalimplementation-plan-mi-and-mn. While 

EPA expects the hearing to go forward 

as set forth above, please monitor our 

website or contact Mayesha Choudhury 

at 312–886–5909 or 

choudhury.mayesha@epa.gov to 

determine if there are any updates. EPA 

does not intend to publish a document 

in the Federal Register announcing 

updates. 

If you require the services of a 

translator or a special accommodation 

such as audio description/closed 

captioning, please pre-register for the 

hearing with Mayesha Choudhury at 

312–886–5909 or choudhury.mayesha@

epa.gov and describe your needs by 

December 11, 2024. EPA may not be 

able to arrange accommodations without 

advance notice. 

I. Background 

A. Requirements of the Clean Air Act 

and EPA’s Regional Haze Rule 

In section 169A of the 1977 

Amendments to the CAA, Congress 

created a program for protecting 

visibility in the nation’s national parks 

and wilderness areas. This section of the 

CAA establishes as a national goal the 

‘‘prevention of any future, and the 

remedying of any existing, impairment 

of visibility in mandatory Class I 

Federal areas 1 which impairment 

results from manmade air pollution.’’ 

Congress added section 169B to the 

CAA in 1990 to address regional haze 

issues. EPA promulgated a rule to 

address regional haze on July 1, 1999 


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2The set of ‘‘major stationary sources’’ potentially 

subject to BART is listed in CAA section 169A(g)(7) 

and includes ‘‘taconite ore processing facilities.’’ 

3 ‘‘BART-eligible sources’’ are those sources that 

have the potential to emit 250 tons or more of a 

visibility-impairing air pollutant, were not in 

operation prior to August 7, 1962, but were in 

existence on August 7, 1977, and whose operations 

fall within one or more of 26 specifically listed 

source categories. 40 CFR 51.301. 

4Fuel sulfur content BART limits were also set 

for two process boilers and a line dryer at Tilden. 

Those limits are not impacted by this action. 

5Stoichiometry refers to the relationship between 

the actual quantity of combustion air to the 

theoretical minimum quantity of air needed for 100 

percent combustion of the fuel. 

6Cliffs acquired ArcelorMittal Steel Production 

Company in 2020. Previously, Minorca was owned 

by ArcelorMittal and Hibbing was jointly owned by 

ArcelorMittal, Cliffs and United States Steel. 

Currently, Minorca is owned by Cliffs and Hibbing 

is jointly owned by Cliffs and United States Steel. 

(64 FR 35714), codified at 40 CFR part 

51, subpart P (herein after referred to as 

the ‘‘Regional Haze Rule’’). The 

Regional Haze Rule codified and 

clarified the BART provisions in the 

CAA and revised the existing visibility 

regulations to add provisions addressing 

regional haze impairment and to 

establish a comprehensive visibility 

protection program for Class I areas. The 

requirements for regional haze, found at 

40 CFR 51.308 and 51.309, are included 

in EPA’s visibility protection 

regulations at 40 CFR part 51, subpart P. 

Section 169A of the CAA directs 

states, or EPA if developing a FIP, to 

evaluate the use of retrofit controls at 

certain larger, often uncontrolled, older 

stationary sources to address visibility 

impacts from these sources. 

Specifically, section 169A(b)(2)(A) of 

the CAA requires that implementation 

plans contain such measures as may be 

necessary to make reasonable progress 

toward the natural visibility goal, 

including a requirement that certain 

categories of existing major stationary 

sources 2 built between 1962 and 1977 

procure, install, and operate BART as 

determined by EPA. 

Under the Regional Haze Rule, states 

(or in the case of a FIP, EPA) are 

directed to conduct BART 

determinations for such ‘‘BARTeligible’’ sources that may reasonably be 

anticipated to cause or contribute to any 

visibility impairment in a Class I area. 

On July 6, 2005, 70 FR 39104, EPA 

published the Guidelines for BART 

Determinations Under the Regional 

Haze Rule at appendix Y to 40 CFR part 

51 (hereinafter referred to as the ‘‘BART 

Guidelines’’) to assist states and EPA in 

determining which sources should be 

subject to the BART requirements and 

in determining appropriate emission 

limits for each source subject to BART. 

The process of establishing BART 

emission limitations follows three steps. 

First, states, or EPA if developing a FIP, 

must identify and list ‘‘BART-eligible 

sources.’’ 3 Once the state or EPA has 

identified the BART-eligible sources, 

the second step is to identify those 

sources that may ‘‘emit any air pollutant 

which may reasonably be anticipated to 

cause or contribute to any impairment 

of visibility’’ in a Class I area. (Under 

the Regional Haze Rule, a source which 

fits this description is ‘‘subject to 

BART.’’). Third, for each source subject 

to BART, the state or EPA must identify 

the level of control representing BART 

after considering the five factors set 

forth in CAA section 169A(g). The 

BART Guidelines provide a process for 

making BART determinations that states 

can use in implementing the BART 

requirements on a source-by-source 

basis. See 40 CFR part 51, appendix Y, 

at IV.D. 

States, or EPA if developing a FIP, 

must address all visibility-impairing 

pollutants emitted by a source in the 

BART determination process. The most 

significant visibility impairing 

pollutants are SO2, NOX, and particulate 

matter (PM). 

A state implementation plan (SIP) or 

FIP addressing regional haze must 

include source-specific BART emission 

limits and compliance schedules for 

each source subject to BART. Once a 

state or EPA has made a BART 

determination, the BART controls must 

be installed and operated as 

expeditiously as practicable, but no later 

than five years after the date of the final 

SIP or FIP. See CAA section 169A(g)(4) 

and 40 CFR 51.308(e)(1)(iv). In addition 

to what is required by the Regional Haze 

Rule, general SIP requirements mandate 

that the SIP or FIP include all regulatory 

requirements related to monitoring, 

recordkeeping, and reporting for the 

BART controls on the source. See CAA 

section 110(a). 

B. BART FIP for Taconite Facilities in 

Michigan and Minnesota 

EPA is proposing to finalize NOX and/ 

or SO2 limits for the indurating furnaces 

at five taconite facilities in accordance 

with the procedures set forth in the FIP 

addressing the requirement for BART at 

taconite facilities. These facilities 

include Tilden Mining Company 

(Tilden) located at 101 Cci Mine Road, 

Ishpeming, Michigan; Hibbing Taconite 

Company (Hibbing) located at 4950 

Highway 5 North, Hibbing, Minnesota; 

Minorca Mine (Minorca) located at 5950 

Old Highway 53, Virginia, Minnesota; 

Northshore Mining Company—Silver 

Bay (Northshore) located at 10 Outer 

Drive, Silver Bay, Minnesota, and 

United Taconite (UTAC) located at 8470 

Townline Road, Forbes, Minnesota. 

Tilden, Minorca, Northshore, and UTAC 

are owned by Cleveland-Cliffs, Inc. 

(Cliffs), formerly known as Cliffs 

Natural Resources, and Hibbing is 

jointly owned by Cliffs and United 

States Steel. The primary units 

identified as being subject to BART at 

Tilden, Hibbing, Minorca, UTAC, and 

Northshore include the following 

pelletizing, or indurating, furnaces: 

Tilden Grate Kiln Line 1, Hibbing 

Straight-Grate Lines 1–3, Minorca 

Straight-Grate Line 1, UTAC Grate Kiln 

Lines 1 and 2, and Northshore StraightGrate Furnaces 11 and 12.4 The U.S. 

taconite iron ore industry uses two 

types of pelletizing machines or 

processes: straight-grate kilns and grate 

kilns. In a straight-grate kiln, a 

continuous bed of agglomerated green 

pellets is carried through different 

temperature zones with upward draft or 

downward draft blown through the 

pellets on the metal grate. The grate kiln 

system consists of a traveling grate, a 

rotary kiln, and an annular cooler. A 

significant difference between these 

designs is that straight-grate kilns do not 

burn coal and therefore have a much 

lower potential for emitting SO2. 

Further, even within the same kiln type 

or process, individual furnaces (referred 

to as indurating or pelletizing) or 

processes have distinct equipment and 

process characteristics that may affect 

the compatibility and performance of 

certain types of burners. 

On February 6, 2013 (78 FR 8706), 

EPA promulgated a FIP that set BART 

limits for NOX and SO2 emissions from 

furnaces at seven taconite facilities in 

Michigan and Minnesota (‘‘Original 

FIP’’). EPA took this action because 

Michigan and Minnesota had failed to 

meet a statutory deadline to submit their 

Regional Haze SIPs and subsequently 

failed to require BART at the taconite 

facilities within their borders. BART 

limits for NOX were based upon the 

performance of high stoichiometric 

(high-stoich) low-NOX burners (LNBs) 5

at two of the taconite furnaces at U.S. 

Steel’s Minntac facility, while BART for 

SO2 was established as no additional 

controls, apart from a limit on the sulfur 

content of coal used in co-firing 

furnaces. 

In a related action, EPA published a 

final partial disapproval of Michigan’s 

and Minnesota’s Regional Haze SIPs on 

September 30, 2013 (78 FR 59825), due 

to the states’ failure to require BART for 

taconite facilities within these states. 

ArcelorMittal USA LLC 

(‘‘ArcelorMittal’’) 6 and Cliffs, owners of 

several taconite facilities affected by the 

FIP, along with the State of Michigan, 


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7On November 15, 2016, the 8th Circuit Court of 

Appeals terminated the June 14, 2013, stay and 

extended the deadlines in the Original FIP by one 

day for each day the court’s stay was in place. From 

the day the 2013 FIP was effective to the day it was 

stayed, 98 days elapsed (March 8, 2013, to June 14, 

2013). See Order dated November 15, 2016, in 

response to U.S. EPA’s Petition to reconsider the 

Original FIP, EPA–R05OAR–2017–0066–0009 (8th 

Cir. 2016). As a result, the deadlines contained in 

the Original FIP still apply (e.g., 6 months after 

March 8, 2013), only now from the date the stay 

was terminated, minus the number of days that 

elapsed prior to the stay being issued. 

8Taconite facilities typically operate 24 hours per 

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

period; therefore, a 720-hour average is essentially 

equivalent to a 30-day average. 

filed timely petitions for review of the 

Original FIP. ArcelorMittal and Cliffs 

also filed a joint motion seeking a stay 

of the Original FIP, which was granted 

by the Eighth Circuit on June 14, 2013.7

ArcelorMittal, Cliffs, the State of 

Michigan, and others also submitted 

petitions for reconsideration of the 

Original FIP, pursuant to CAA section 

307(d)(7)(B). 42 U.S.C. 7607(d)(7)(B). 

On October 22, 2015 (80 FR 64160), 

in response to the petitions for 

reconsideration and due to new 

information submitted to EPA after 

promulgation of the Original FIP, EPA 

proposed to revise the Original FIP to 

revise NOX and SO2 emission limits for 

certain taconite facilities. On April 16, 

2016 (81 FR 21672), EPA promulgated 

the final 2016 revised FIP (‘‘2016 FIP’’). 

With respect to NOX, the emission 

limits in the 2016 FIP were based on 

information submitted to EPA by Cliffs 

and ArcelorMittal that suggested highstoich LNBs, which formed the basis for 

the NOX limits in the Original FIP, 

posed serious technical hurdles. In the 

2016 FIP, EPA revised the NOX

emission limits for Tilden, Hibbing, 

Minorca, and UTAC, and set forth a 

process to confirm or modify those 

emission limits using continuous 

emissions monitoring system (CEMS) 

data that was to be collected after the 

installation of the selected low-NOX

technology. Under the 2016 FIP, the 

NOX emission limits do not become 

enforceable until EPA confirms or 

modifies the emission limits in 

accordance with procedures set forth in 

the FIP. The NOX emission limits in the 

2016 FIP were based upon low-stoich 

LNBs (for grate kilns) and LNBs that 

utilize a combination of water and 

steam injection and pre-combustion 

technologies (for straight-grate kilns). 

With respect to SO2, EPA granted 

reconsideration of the SO2 limit for 

Tilden’s grate kiln due to information 

that became available after the close of 

the public comment period on the 2013 

FIP regarding Tilden’s intent to burn 

mixed fuels. Cliffs’ intent to burn mixed 

fuels at Tilden was not considered in 

the Original FIP and would have led to 

an inability to meet the established 

BART limit. The 2016 FIP limits the 

sulfur content of the coal combusted on 

Tilden Line 1 and sets an SO2 emission 

limit for the furnace. 

Cliffs and ArcelorMittal filed petitions 

for review of the 2016 FIP due to a 

dispute over the UPL equation in the 

final rule. The 2016 FIP requirements 

for each facility are set forth in 40 CFR 

52.1183 for Michigan and 40 CFR 

52.1235 for Minnesota and discussed 

further in the remainder of this action. 

II. Basis for NOX Limits 

The 2016 FIP set emission limits in 

pounds (lbs) of NOX per million British 

Thermal Unit (MMBtu), based on a 30- 

day (720-hour) rolling average, and 

established a process to either confirm 

or modify the NOX emission limits 

within established ranges based on 

CEMS data that Tilden, Hibbing, 

Minorca, and UTAC were required to 

submit to EPA by dates specified in the 

2016 FIP.8 The FIP also specified that 

the NOX emission limits for these 

facilities would become enforceable 

only after EPA’s confirmation or 

modification of the NOX emission limits 

reflecting EPA’s expectation that the 

owner or operator of each facility would 

provide the requisite data to EPA by the 

dates specified in the FIP. EPA’s efforts 

to finalize NOX emission limits for these 

facilities by the deadlines established in 

the FIP were complicated by several 

implementation issues, including 

challenges with installation of control 

technology, delays in receipt of requisite 

data, and emission limit modification 

requests not conforming to the 

requirements set forth in the FIP. 

The NOX emission limits established 

for each furnace and the ranges of limits 

allowable under the limit modification 

process are set forth in Table 1. As 

indicated in Table 1, the emission limits 

for certain furnaces vary by the type of 

fuel being used (natural gas or ‘‘co-fire,’’ 

which is a combination of natural gas 

and coal). 

TABLE 1—NOX LIMITS AND LIMIT MODIFICATION RANGES ESTABLISHED IN THE 2016 FIP 

Furnace Emission limit 

(lbs NOX/MMBtu) 

Emission limit 

modification range 

(lbs NOX/MMBtu) 

Tilden Line 1: 

Natural Gas .............................................................................................................................. 2.8 2.8–3.0 

Co-fire ....................................................................................................................................... 1.5 1.5–2.5 

Hibbing Line 1 .................................................................................................................................. 1.2 1.2–1.8 

Hibbing Line 2 .................................................................................................................................. 1.2 1.2–1.8 

Hibbing Line 3 .................................................................................................................................. 1.2 1.2–1.8 

Minorca ..................................................................................................................................... 1.2 1.2–1.8 

UTAC Line 1: 

Natural Gas .............................................................................................................................. 2.8 2.8–3.0 

Co-fire ....................................................................................................................................... 1.5 1.5–2.5 

UTAC Line 2: 

Natural Gas .............................................................................................................................. 2.8 2.8–3.0 

Co-fire ....................................................................................................................................... 1.5 1.5–2.5 

For Tilden, Hibbing, Minorca, and 

UTAC, the process specified in the 2016 

FIP to either confirm or modify the NOX

emission limits within the established 

ranges included the installation of a 

CEMS, submission of an engineering 

report to EPA, installation of NOX

reduction control technology, 

submission of pellet quality analyses to 

EPA, and submission to EPA of a report 

to either confirm or modify the limit. 

For any furnace without CEMS already 

installed, CEMS installation was 

required for each furnace by 6 months 

after May 12, 2016, and the owner or 

operator was required to submit 

quarterly CEMS data to EPA after May 

12, 2016, for the time periods specified 


ddrumheller on DSK120RN23PROD with PROPOSALS1
96156 Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 

9 Data distribution analyses are available in the 

docket for this action. 

10Taconite facilities typically operate 24 hours 

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

day period; therefore, a 720-hour average is 

essentially equivalent to a 30-day average. For 

facilities that both burn natural gas exclusively and 

co-fire with coal, i.e., Tilden and UTAC, a 30-day 

period may involve operation with only natural gas 

as well as operation with co-firing of coal. 

Therefore, the 2016 FIP established UPL equations 

based on 720-hour averages to allow for the 

separation of hours when burning only natural gas 

from hours when co-firing with coal. When 

calculating an emission limit that applies only 

when burning natural gas, emissions are averaged 

over 720 successive hours in which the unit burns 

only natural gas. When calculating a co-firing 

emission limit, emissions are averaged over 720 

successive hours in which the unit burns a gas/coal 

mix. All emission limit modifications were 

calculated based on 720-hour averages, consistent 

with the equations at 40 CFR 52.1183(p) and 40 

CFR 52.1235(f). However, EPA is proposing 

modified emission limits in the form of a 30-day 

average if the facility burns only one fuel or if the 

modified limit applies to all fuels. In those 

circumstances, there is no need to be able to 

separate the hourly data to determine compliance 

with the emission limit. 

11April 16, 2016, 81 FR 21672, 21680. 

12See emission limit calculation files in the 

docket for this action. 

below in Table 2. Engineering reports 

containing detailed engineering 

analyses and modeling of the selected 

NOX reduction technology for each 

furnace demonstrating that the 

technology was designed to meet an 

emission limit equal to the lower bound 

of the established range were required to 

be submitted to EPA by the deadlines 

specified in Table 2. NOX reduction 

technology was required to be installed 

two months after the engineering report 

submission deadline. Beginning on the 

earlier of six months after the 

installation of NOX reduction 

technology or the deadline for 

installation of the NOX reduction 

technology, the owner or operator was 

required to submit quarterly pellet 

quality analyses to EPA, including an 

explanation of causes for pellet samples 

that failed to meet the acceptable range 

for any pellet quality analysis factor, for 

the time periods specified in Table 2. At 

the end of the CEMS and pellet quality 

data collection periods, the owner or 

operator of each furnace may submit a 

report to EPA to either confirm or 

modify the NOX limits within the 

bounds described in the 2016 FIP (and 

above in this section). The 2016 FIP also 

allows the owner or operator to submit 

a report proposing a single NOX limit for 

all fuels. The process for confirming or 

modifying limits detailed in the 2016 

FIP specifies that EPA’s determinations 

shall be based on the appropriate UPL 

equation, using CEMS data that meet 

pellet quality specifications and proper 

furnace/burner operation. For a more 

detailed description of the process set 

forth in the 2016 FIP to confirm or 

modify the emission limits, see 40 CFR 

52.1183 and 40 CFR 52.1235. 

TABLE 2—TIMELINES OF PROCESSES TO CONFIRM OR MODIFY LIMITS

Furnace 

Period of 

CEMS data 

required for 

submission 

to EPA 

Engineering 

report 

deadline 

NOX reduction 

technology 

installation 

deadline 

Period of 

pellet 

quality data 

required for 

submission 

to EPA * 

Report to 

confirm or 

modify limit 

deadline 

Months after May 12, 2016 

Tilden Line 1 ........................................................................ 0–57 48 50 50–57 57 

Hibbing Line 1 ...................................................................... 6–34 24 26 26–34 34 

Hibbing Line 2 ...................................................................... 6–52 42 44 44–52 52 

Hibbing Line 3 ...................................................................... 6–57 48 50 50–57 57 

Minorca’s Indurating Furnace .............................................. 6–52 42 44 44–52 52 

UTAC Line 1 ........................................................................ 0–34 24 26 26–34 34 

UTAC Line 2 ........................................................................ 0–52 42 44 44–52 52 

* If the owner or operator installed NOX reduction technology more than six months before the required date, pellet quality analyses were required to be submitted to EPA beginning six months after installation. 

The 2016 FIP incorporates two UPL 

equations to calculate emission limits. 

The appropriate equation is determined 

by the statistical distribution of the 

hourly CEMS data. If the data are 

normally distributed and statistically 

independent, the equation in 40 CFR 

52.1183(p)(1) and 40 CFR 52.1235(f)(1) 

is used. If the data are not normally 

distributed or are normally distributed 

but not statistically independent, the 

non-parametric equation in 40 CFR 

52.1183(p)(2) and 40 CFR 52.1235(f)(2) 

is used. None of the CEMS data 

submitted are normally distributed and 

statistically independent, therefore the 

non-parametric equation is the 

applicable equation for all limit setting 

in this action.9

The non-parametric equation in the 

2016 FIP calculates a 95th percentile 

UPL by ranking 720-hour averages of 

NOX emissions in lbs/MMBtu from 

lowest to highest and identifying the 

value at the 95th percentile of the data 

set as the UPL and emission limit.10

While a 95th percentile UPL establishes 

an emission rate that a source is 

predicted to be below during at least 95 

out of 100 averaging periods, it was not 

EPA’s intent to set a limit that a source 

would be expected to exceed five 

percent of the time once the limit was 

in place. Rather, EPA used the 95th 

percentile UPL to ensure that the final 

emission limits would be consistent 

with the actual emission reduction 

capabilities of the BART controls, as 

required by 40 CFR 51.301, which 

defines BART as ‘‘the degree of 

reduction achievable.’’ 11 EPA expected 

that during the eight-month CEMS data 

collection period, furnace operators 

would be adjusting numerous variables 

to optimize control technology 

performance, which would result in 

higher emissions at times during the 

initial ‘‘shakedown’’ period. Once the 

eight-month data collection period was 

over, EPA expected that the operators 

would have gained sufficient experience 

to run the furnaces and control 

technologies with fewer adjustments, 

meaning less emission variations and 

lower emissions overall. EPA selected 

the 95th percentile UPL to ensure the 

elevated emissions expected during the 

initial shakedown period would not 

become the basis for final emission 

limits. 

However, once continuous data 

collection began, the CEMS data did not 

show the expected elevated emissions 

levels during the shakedown period and 

emissions were not consistently lower 

toward the end of the data collection 

period as compared to the beginning of 

the period.12 Therefore, EPA has 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 96157 

13 Data analyses and emissions calculations are 

available in the docket for this action. 

14 40 CFR 52.1183(k)(1). 

15 40 CFR 52.1183(k)(1)(viii). 

16See ‘‘Tilden NOX limit modification report 

(Feb. 12, 2021)_Redacted.pdf,’’ available in the 

docket for this action. 

17See Tilden Emission Limit Calculations, 

available in the docket for this action. 18See 40 CFR 52.1235((b)(1)(ii). 

determined that using the UPL equation 

at the 99th percentile is more 

appropriate to establish an emission 

limit consistent with the actual 

emission reduction capabilities of the 

BART controls and is proposing to 

modify the UPL equations used to 

calculate both the NOX and SO2

emission limits to reflect use of the 99th 

percentile. The emission limits EPA is 

proposing in this action were calculated 

using the UPL equations at 40 CFR 

52.1183(p) and 40 CFR 52.1235(f) at the 

99th percentile.13

A. Tilden 

For Tilden’s indurating furnace, 

Tilden Line 1 (EUKILN1), the 2016 FIP 

established a specific NOX BART 

emission limit of 2.8 pounds of NOX/ 

MMBtu when burning natural gas, while 

allowing for potential modification of 

the limit within the range of 2.8–3.0 lbs 

NOX/MMBtu. Similarly, the 2016 FIP 

established a specific NOX BART 

emission limit of 1.5 lbs NOX/MMBtu 

when co-firing coal and natural gas, 

with an allowance for potential 

modification of the limit within the 

range of 1.5–2.5 lbs NOX/MMBtu.14 The 

2016 FIP also allowed for the 

establishment of a single NOX limit for 

all fuels.15

Tilden submitted a partially complete 

engineering report on May 21, 2020, and 

submitted the final engineering report 

on July 30, 2020. Tilden implemented 

low-stoichiometry LNBs designed to 

achieve an emission rate of 2.8 lbs NOX/ 

MMBtu when firing exclusively natural 

gas and 1.5 lbs NOX/MMBtu when cofiring with coal, as described in the 

engineering report submitted to EPA. 

On February 12, 2021, Tilden 

submitted a report requesting 

modification of the NOX limits for Line 

1 pursuant to 40 CFR 52.1183 (k)(1)(vi). 

Tilden requested an emission limit of 

3.0 lbs NOX/MMBtu for all fuels. 

Tilden’s limit modification request was 

accompanied by CEMS data (in 30-day 

rolling averages) from September 12, 

2020, to February 2, 2021. On May 21, 

2021, Tilden provided hourly emission 

data for July 1, 2020, to February 11, 

2021. Approximately half of these data 

were collected when Tilden was cofiring with coal and half were collected 

when Tilden was burning exclusively 

natural gas. Tilden demonstrated that 

when burning natural gas, NOX

emission rates recorded were higher 

than the modeling results presented in 

the engineering report, and above the 

high end of the limit range established 

in the 2016 FIP (2.8–3.0 lbs/MMBtu). 

The CEMS data submitted to EPA when 

burning coal recorded emission rates 

within the range specified in the 2016 

FIP (1.5–2.5 lbs/MMBtu). Tilden 

explained that the furnace is unable to 

achieve 3.0 lbs NOX/MMBtu when 

burning exclusively natural gas and 

would need to burn a minimum of 80% 

coal when co-firing to meet a limit of 2.0 

lbs NOX/MMBtu. Tilden stated a 

preference to maximize natural gas 

usage and supplement with solid fuel as 

needed to meet NOX limits.16

The 2016 FIP provides Tilden the 

option to propose, for EPA’s 

consideration and approval, a single 

NOX emission limit for all fuels based 

on a 30-day rolling average. Citing the 

CEMS data, Tilden requested a revised 

NOX BART limit of 3.0 lbs NOX/MMBtu 

for all fuels that would apply on a 

rolling 30-day average, contending that 

this emission limit is the most stringent 

limit that can be met without substantial 

increases in coal usage, while 

maintaining pellet quality standards. 

Based on the equation set forth at 40 

CFR 52.1183(p)(2), EPA calculated a 

720-hour average NOX emission limit of 

3.8 lbs NOX/MMBtu when burning 

exclusively natural gas, and separately, 

an emission limit of 1.9 lbs NOX/ 

MMBtu when burning mixed fuel.17

While CEMS data show the installed 

emission control measures reduced NOX

emissions, the selected technology 

failed to achieve emission rates within 

the specified FIP ranges when burning 

only natural gas (2.8–3.0 lbs NOX/ 

MMBtu). Using the non-parametric 

equation with the full data set, 

unseparated by fuel type, EPA 

calculated a 720-hour average UPL of 

3.7 lbs NOX/MMBtu. EPA evaluated 

these CEMS data and considered 

Tilden’s requested single NOX emission 

limit of 3.0 lbs NOX/MMBtu for all fuels 

based on a 30-day rolling average, as 

allowed at 40 CFR 52.1183(k)(1)(viii). 

EPA has concluded that Tilden’s 

requested emission limit of 3.0 lbs NOX/ 

MMBtu for all fuels based on a 30-day 

rolling average is appropriate and 

reflects BART. It allows Tilden to select 

a fuel mix that maximizes natural gas 

usage and minimizes coal usage if the 

facility so chooses without exceeding 

the natural gas emission limit range 

established in the 2016 FIP. This has the 

duel environmental (visibility) benefit 

of minimizing NOX emissions by setting 

an emissions limit that is below the 

calculated natural gas-only rate, and 

also potentially minimizing the use of 

coal and the associated SO2 emissions 

from coal burning. Therefore, based on 

these data and as provided at 40 CFR 

52.1183(k)(1)(viii), EPA is proposing 

that a modified limit of 3.0 lbs NOX/ 

MMBtu for all fuels, with compliance to 

be determined on a rolling 30-day 

average basis, reflects BART for the 

Tilden Line 1 indurating furnace. 

B. Hibbing 

For Hibbing Lines 1, 2, and 3, the 

2016 FIP established NOX BART 

emission limits of 1.2 lbs NOX/MMBtu 

that applied to each furnace 

individually, with provisions allowing 

for potential modification of the limits 

within the range of 1.2–1.8 lbs NOX/ 

MMBtu.18

Hibbing implemented the NOX

reduction measures described in its 

engineering report, submitted to EPA on 

May 11, 2018, identified as LNBs in 

conjunction with water injection, at 

Hibbing Lines 1, 2, and 3. Hibbing 

installed CEMS on Lines 1, 2, and 3 and 

provided EPA with hourly NOX

emissions data on March 12, 2019, 

September 11, 2020, and February 12, 

2021, for Lines 1, 2 and 3, respectively, 

documenting actual emissions after 

installation of LNB technology. 

Hibbing’s submittals included CEMS 

data from July 12, 2018, to March 11, 

2019, for Line 1; January 12, 2020, 

through September 1, 2020, for Line 2; 

and August 3, 2020, to February 11, 

2021, for Line 3. The hourly CEMS data 

identified hours excluded from the 

limit-setting calculations because pellets 

failed to meet pellet quality 

specifications. Although the limitsetting period for Line 3 established in 

the 2016 FIP began August 3, 2020, Line 

3 did not operate during the period 

between July 12 to August 3, 2020, due 

to COVID-related reasons. Line 2 did not 

operate from May 1, 2020, to July 31, 

2020, during the limit setting period for 

similar reasons. On November 25, 2020, 

Hibbing provided additional 

information requested by EPA, 

including hourly CEMS data for Lines 1, 

2, and 3 in Excel format to facilitate 

independent calculation of emission 

limits and identification of hours when 

the burner was not operated within the 

parameters modeled in the engineering 

report. 

The requirements at 40 CFR 

52.1235((b)(1)(ii)(A)(6), (B)(6), and (C)(6) 

set forth the process for submitting data 

to support limit modifications under the 

2016 FIP. At the time of the initial 


ddrumheller on DSK120RN23PROD with PROPOSALS1
96158 Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 

19See Hibbing Emission Limit Calculations, 

available in the docket for this action. 

20 40 CFR part 51, appendix Y, at V. 

21See 40 CFR 52.1235((b)(1)(v). 

22CEMS data in the September 11, 2020, 

submittal was presented as 720-hour rolling 

averages. On November 25, 2020, Minorca provided 

the hourly CEMS data for the same January 12, 

2020, to September 10, 2020, time period to allow 

for independent calculation of 720-hour averages. 

23See Minorca Emission Limit Calculations, 

available in the docket for this action. 

24 40 CFR 52.1235(b)(1)(iv). 

CEMS data submissions, Hibbing 

requested NOX emission limits of 1.7, 

1.5, and 1.6 lbs NOX/MMBtu on Lines 

1, 2, and 3, respectively. The facility 

cited sub-zero temperatures and other 

factors that may have affected the 

calculated emission rates and restricted 

production. Further, Hibbing provided 

regression analyses assessing the 

relationship between furnace feed rates 

and NOX emission rates during the 

limit-setting periods to support the 

requested limit increases. 

On October 22, 2021, Hibbing 

submitted a request to EPA to establish 

a crossline average emission limit for 

Lines 1, 2, and 3 of 1.6 lbs NOX/MMBtu, 

with compliance to be determined on a 

30-day rolling average basis. The 

submittal included hourly CEMS data 

for the same time periods as Hibbing’s 

initial limit modification submittals and 

a regression analysis assessing the 

relationship between furnace feed rates 

and NOX emission rates during the 

limit-setting periods to support the 

requested limit increases. The hourly 

CEMS data submitted to EPA included 

a description of the failure analyses 

identifying potential reasons for pellets 

failing to meet pellet quality 

specifications for hours excluded in the 

limit-setting calculation. 

There is no basis in the FIP for 

adjusting emission limits to account for 

possible future production levels based 

upon an assumed correlation between 

feed rates and emissions. Therefore, in 

accordance with 40 CFR 52.1235(f)(2), 

EPA calculated 720-hour average NOX

emission limits of 1.5 lbs NOX/MMBtu 

for Line 1, 1.4 lbs NOX/MMBtu for Line 

2, and 1.5 lbs NOX/MMBtu for Line 3.19

Under the BART Guidelines, a source 

may be permitted to ‘‘ ‘average’ 

emissions across any set of BARTeligible 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 BARTeligible units that constitute BARTeligible sources.’’ 20 EPA averaged the 

single line limits described above and 

calculated a crossline 720-hour average 

emission limit of 1.5 lbs NOX/MMBtu. 

The NOX controls have been installed 

and are being operated on all three 

lines. Based on EPA’s analysis, this 

crossline average emission limit is equal 

to the reductions that would be obtained 

by controlling each line separately. 

Therefore, based on these data and as 

provided at 40 CFR 

52.12335(b)(1)(ii)(A)(7), (B)(7), and 

(C)(7), and consistent with 40 CFR 

51.308(e) and 40 CFR part 51, appendix 

Y, at V, EPA is proposing that a 

crossline average emission limit of 1.5 

lbs NOX/MMBtu for Hibbing Lines 1, 2, 

and 3, with compliance to be 

determined on a 30-day rolling average 

basis, reflects NOX BART for Hibbing 

Lines 1, 2, and 3. 

C. Minorca 

For Minorca’s indurating furnace, the 

2016 FIP established a NOX BART 

emission limit of 1.2 lbs NOX/MMBtu, 

while allowing for potential 

modification of the limit within the 

range of 1.2–1.8 lbs NOX/MMBtu.21

On November 12, 2019, Minorca 

submitted an engineering report to EPA 

which identified the low NOX

technology to be installed on Line 1 as 

an LNB, water injection, and utilization 

of specific operating parameters. The 

combined use of these measures was 

projected to meet an emission limit of 

1.2 lbs NOX/MMBtu based on a 30-day 

average. On September 11, 2020, 

Minorca submitted CEMS data for the 

period January 12, 2020, to September 

10, 2020, excluding the CEMS values 

that did not meet pellet quality 

specifications, consistent with the 2016 

FIP.22

On October 22, 2021, Minorca 

submitted supplemental information 

consisting of 720-hour averages of 

CEMS data from January 12, 2020, 

through September 30, 2021. Adding the 

data from September 10, 2020, through 

September 30, 2021, to the original data 

set, Minorca calculated an emission 

limit of 1.6 lbs NOX/MMBtu using the 

equation at 40 CFR 52.1235(f)(2). 

Minorca then performed a regression 

analysis assessing the relationship 

between furnace pellet production rates 

and NOX emission rates during the 

limit-setting period to support the 

requested limit increase. Minorca cited 

the climate in Minnesota and other 

factors that may have affected 

production rates in its explanation of 

why the emission limit should be 

adjusted to 1.7 lbs NOX/MMBtu. 

Based on the non-parametric equation 

at 40 CFR 52.1235(f)(2), EPA evaluated 

the 720-hour average NOX emission data 

for the full data set submitted and 

calculated an emission limit of 1.6 lbs 

NOX/MMBtu.23 There is no basis in the 

FIP for adjusting emission limits to 

account for possible future production 

levels based upon an assumed 

correlation between feed rates and 

emissions. Therefore, based on these 

data and as provided at 40 CFR 

52.1235(b)(1)(v)(7), EPA is proposing 

that a modified limit of 1.6 lbs NOX/ 

MMBtu, with compliance to be 

determined on a rolling 30-day average 

basis, reflects BART for the Minorca 

Line 1 indurating furnace. 

D. UTAC 

For UTAC’s indurating furnaces, 

Grate Kiln Line 1 (EU040) and Grate 

Kiln Line 2 (EU042), the 2016 FIP 

established specific NOX BART limits of 

2.8 pounds of NOX/MMBtu when 

burning natural gas, while allowing for 

potential modification of the limits 

within the range of 2.8–3.0 lbs NOX/ 

MMBtu. Similarly, the 2016 FIP 

established specific NOX BART limits of 

1.5 lbs NOX/MMBtu when co-firing coal 

and natural gas, while allowing for 

potential modification of the limits 

within the range of 1.5–2.5 lbs NOX/ 

MMBtu.24 The 2016 FIP also allowed for 

the establishment of a single NOX limit 

for all fuels. 

UTAC submitted an engineering 

report for Line 1 on May 11, 2018. 

UTAC installed and began operating the 

sub-stoichiometric staged combustion 

LNB designed to achieve an emission 

rate of 2.8 lbs NOX/MMBtu when firing 

exclusively natural gas and 1.5 lbs NOX/ 

MMBtu when co-firing with coal, as 

described in the engineering report 

submitted to EPA. UTAC subsequently 

made modifications to the Line 1 LNB 

in September 2018. On March 12, 2019, 

UTAC submitted a report requesting 

modification of the co-firing NOX limit 

for Line 1 to 2.5 lbs NOX/MMBtu, based 

upon 720-hour averages from February 

2019. 

On November 12, 2019, UTAC 

submitted a report to EPA to address the 

requirement for an engineering report 

for Line 2. On November 12, 2021, 

UTAC submitted information on the 

LNB selected for Line 2, a modified 

version of the LNB installed on Line 1. 

This submittal included a report on 

computational fluid dynamics modeling 

demonstrating the burner was designed 

to achieve an emission rate of 2.8 lbs 

NOX/MMBtu when firing exclusively 

natural gas and 1.5 lbs NOX/MMBtu 

when co-firing with coal. On April 11, 

2023, UTAC submitted an analysis of 

Line 1 and Line 2 NOX performance 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 96159 

25See United Taconite Emission Limit 

Calculations, available in the docket for this action. 

26 40 CFR part 51, appendix Y, at V. 

27See Tilden Emission Limit Calculations, 

available in the docket for this action. 

post LNB installations and requested a 

crossline average limit of 3.0 lb NOX/ 

MMBtu for all fuels, based on a 30-day 

rolling average. Along with the analysis, 

UTAC submitted 720-hour averages of 

total lbs NOX/MMBtu for Lines 1 and 2 

combined for the time period of January 

25, 2022, to March 26, 2023. UTAC also 

submitted hourly CEMS and process 

information for this time period, which 

UTAC claimed as confidential business 

information, so that EPA could verify 

the calculations. 

Based on the equation set forth at 40 

CFR 52.1235(f)(2), EPA calculated 720- 

hour average NOX emission limits of 2.3 

lbs NOX/MMBtu and 3.6 lbs NOX/ 

MMBtu when burning exclusively 

natural gas for Lines 1 and 2, 

respectively. Separately, EPA calculated 

an emission limit of 3.1 lbs NOX/ 

MMBtu when burning mixed fuel on 

Line 2. There were 475 hours of cofiring data for Line 1, which is not 

sufficient to calculate a 720-hour 

average NOX emission limit. EPA also 

calculated an emission limit of 3.1 lbs 

NOX/MMBtu when combining hourly 

emissions data for both lines and all 

fuels.25 While CEMS data show the 

installed emission control measures 

reduced NOX emissions, the selected 

technology failed to achieve emission 

rates within the specified FIP ranges, 

particularly when evaluating separate 

limits for each fuel type. 

As discussed in II.B., under the BART 

Guidelines, a source may be permitted 

to ‘‘ ‘average’ emissions across any 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 BARTeligible units that constitute BARTeligible sources.’’ 26 EPA evaluated the 

CEMS data and considered UTAC’s 

requested crossline average NOX

emission limit of 3.0 lbs NOX/MMBtu 

for all fuels, for Lines 1 and 2, with 

compliance to be determined on a 30- 

day rolling average basis. Based on 

EPA’s analysis, this crossline average 

emission limit is equal to the reductions 

that would be obtained by controlling 

each line separately and is within the 

natural gas NOX emission limit range 

established in the 2016 FIP. A single 

fuel-neutral emission limit allows 

UTAC to select a fuel mix that 

maximizes natural gas usage and 

minimizes coal usage without exceeding 

the natural gas emission limit range 

established in the 2016 FIP. This has the 

dual environmental (visibility) benefit 

of minimizing NOX emissions by setting 

an emissions limit that is below the 

calculated natural gas-only rate, and 

also potentially minimizing the use of 

coal and the associated SO2 emissions 

from burning coal. Therefore, based on 

these data and as provided at 40 CFR 

52.1235(b)(1)(iv)(A)(8) and (B)(8), and 

consistent with 40 CFR 51.308(e) and 40 

CFR part 51, appendix Y, at V, EPA is 

proposing that a crossline emission 

limit of 3.0 lbs NOX/MMBtu for all fuels 

for UTAC Lines 1 and 2, based on a 

rolling 30-day average, reflects BART for 

UTAC Lines 1 and 2. 

III. Basis for SO2 Limits 

As previously described, the Original 

FIP determined that existing controls 

reflected SO2 BART for Minorca, 

Hibbing, and Northshore, and 

established SO2 emission limits for each 

furnace, with the option or requirement, 

depending on the facility, that the 

owner or operator submit one year of 

CEMS data to EPA to set a revised SO2

emission limit calculated using the 

appropriate UPL equation. The 2016 FIP 

limited the sulfur content of the coal 

burned at Tilden, set an SO2 emission 

limit, and required Tilden to submit one 

year of CEMS data to EPA to set a 

revised SO2 emission limit calculated 

using the appropriate UPL equation. For 

a more detailed description of the 

existing SO2 emission limits and the 

process set forth to modify the emission 

limits, see 40 CFR 52.1235 (Hibbing, 

Minorca, and Northshore) and 40 CFR 

52.1183 (Tilden). As discussed above in 

II., EPA has calculated the emission 

limits using the appropriate UPL 

equation at the 99th percentile. 

A. Tilden 

For Tilden, the 2016 FIP established 

a specific SO2 BART emission limit of 

500 pounds of SO2 per hour (lbs/hr) for 

Grate Kiln Line 1, with no more than 

0.60 percent sulfur by weight based on 

a monthly block average for any coal 

usage. The 2016 FIP also required that 

the owner or operator of Tilden 

calculate an SO2 emission limit based 

on one year of hourly CEMS emissions 

data using the appropriate UPL equation 

provided in 40 CFR 52.1183(p) and 

submit such calculations and data to 

EPA by 36 months after May 12, 2016. 

The 2016 FIP provides that EPA may 

revise the emission limit downward to 

reflect the calculated SO2 emission rate; 

however, EPA may not increase the SO2

limit above 500 lbs SO2/hr. 

On October 1, 2018, Tilden submitted 

SO2 emissions data to EPA reflecting 

Tilden burning exclusively natural gas 

during the period March 28, 2017, 

through March 27, 2018. Citing various 

production-related concerns, Tilden 

adjusted its calculated limit to account 

for expected higher production capacity 

and higher ore sulfur content, which 

resulted in an adjusted expected 

emission rate of 568 lbs SO2/hr. Tilden 

requested an SO2 emission limit of 500 

lbs/hour for all fuels, regardless of 

natural gas or coal fuel usage, as 

established in the 2016 FIP. On 

November 10, 2022, Tilden submitted 

hourly SO2 data for Line 1 from the 

same time period of March 28, 2017, 

through March 27, 2018, during which 

time Tilden was exclusively burning 

natural gas. On March 1, 2023, Tilden 

provided hourly co-firing CEMS data for 

July 12, 2018, through July 11, 2019. On 

March 30, 2023, Tilden provided hourly 

CEMS data for the time period March 

27, 2018, through March 26, 2019, 

which included both co-firing and 

natural gas-only operation. 

The 2016 FIP established a single SO2

emission limit to apply regardless of 

natural gas or coal fuel usage, which 

Tilden must meet at all times. 

Consistent with this approach, and 

because SO2 emissions are higher when 

Tilden is co-firing and the emission 

limit must be met at all times, EPA is 

proposing to base the emission limit 

modification calculations on all cofiring data included in Tilden’s March 

1, 2023, and March 30, 2023, CEMS data 

submissions. Based on the equation set 

forth at 40 CFR 52.1183(p)(2), EPA 

calculated an emission limit of 189 lbs 

SO2/hour consistent with this 

approach.27 There is no basis in the FIP 

for adjusting emission limits to account 

for possible future production levels or 

possible higher ore sulfur content. 

Therefore, based on these data and as 

provided at 40 CFR 52.1183(k)(3), EPA 

is proposing that an SO2 limit of 189 lbs 

SO2/hr for the Tilden Line 1 indurating 

furnace, with compliance to be 

determined on a 30-day rolling average 

basis, reflects SO2 BART for Tilden Line 

1. 

B. Hibbing 

For Hibbing Lines 1, 2, and 3, the 

Original FIP set an aggregate emission 

limit of 247.8 lbs SO2/hr, based on a 30- 

day rolling average and excluding 

emissions resulting from the 

combustion of fuel oil, and provided 

Hibbing the option of calculating a 

revised SO2 emission limit by 20 

months after March 8, 2013, based on 

one year of hourly CEMS emissions data 

and the non-parametric UPL equation. If 

any fuel oil is burned after the first day 


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28While Hibbing’s SO2 BART limit is not being 

modified, the regulatory text at 40 CFR 

52.1235(b)(2)(ii) is being revised to remove the 

original limit modification provisions and clarify 

that Hibbing’s SO2 BART limit is final. 

29See Minorca Emission Limit Calculations, 

available in the docket for this action. 

30See Northshore Emission Limit Calculations, 

available in the docket for this action. 

31 40 CFR 52.1183(k)(1)(viii), 

52.1235(b)(1)(iv)(A)(8) and 52.1235(b)(1)(iv)(B)(8). 

that SO2 CEMS were required to be 

operational, the 2016 FIP requires 

Hibbing to submit the gallons of fuel oil 

burned per hour, the sulfur content of 

the fuel oil, and the SO2 emissions in 

pounds per hour, so that EPA can 

establish an SO2 emissions limit for fuel 

oil. Hibbing chose not to calculate a 

revised SO2 emission limit.28

C. Minorca 

For Minorca, the Original FIP set an 

emission limit of 38.16 lbs SO2/hour, 

based on a 30-day rolling average and 

excluding emissions when Minorca is 

combusting fuel oil, with an allowance 

for potential modification of the limit 

based on one year of hourly CEMS data 

submitted to EPA by 20 months after 

March 8, 2013. If any fuel oil is burned 

after the first day that SO2 CEMS were 

required to be operational, the 2016 FIP 

requires Minorca to submit the gallons 

of fuel oil burned per hour, the sulfur 

content of the fuel oil, and the SO2

emissions in pounds per hour so that 

EPA can establish an SO2 emissions 

limit for fuel oil. 

On April 6, 2018, Minorca submitted 

a request to modify the SO2 limit 

established in the 2016 FIP. Minorca 

ranked hourly data from the period 

March 1, 2017, through March 31, 2018, 

adjusted the calculated limit based on 

potential increased production rates, 

and requested an emission limit of 73.79 

lbs SO2/hour. On October 14, 2019, 

Minorca submitted additional hourly 

SO2 CEMS emission data for the time 

period of September 8, 2018, through 

September 7, 2019, revising their 

request to an emission limit of 208.66 

lbs SO2/hr. Minorca adjusted the 

calculated limit based on potential 

increased production rates, maximum 

ore sulfur content based on a ratio of 

maximum percent sulfur, and pellet 

type. 

Using the equation set forth at 40 CFR 

52.1235(f)(2) and the most recent CEMS 

data from September 8, 2018, through 

September 7, 2019, EPA calculated an 

SO2 emission limit of 68.2 lbs SO2/ 

hour.29 There is no basis in the FIP for 

adjusting emission limits to account for 

possible future production levels or 

possible higher ore sulfur content. 

Therefore, based on these data and as 

provided at 40 CFR 52.1235(b)(2)(v) and 

40 CFR 51.308(e), EPA is proposing that 

an emission limit of 68.2 lbs SO2/hr, 

based on a 30-day rolling average, 

reflects SO2 BART for the Minorca 

indurating furnace. 

D. Northshore 

For Northshore, the Original FIP set 

an aggregate emission limit of 39.0 lbs 

SO2/hour for Furnace 11 (EU100/ 

EU104) and Furnace 12 (EU110/EU114), 

based on a 30-day rolling average and 

excluding emissions resulting from the 

combustion of fuel oil, with a 

requirement that the owner or operator 

calculate a revised limit based on one 

year of hourly CEMS data and submit 

such data and calculations to EPA by 20 

months after March 8, 2013. 

On April 11, 2018, Northshore 

submitted an SO2 emission limit 

modification request which included 

CEMS data from January 16, 2017, 

through January 15, 2018. Northshore 

adjusted the calculated emission limit 

based on potential increased production 

rates and requested a limit of 22.1 lbs 

SO2/hour. 

On November 21, 2018, Northshore 

submitted a revised limit modification 

request of 49 lbs SO2/hr. This limit 

modification request included data for 

the time period of January 16, 2017, 

through January 15, 2018, and adjusted 

the calculated limit based on potential 

increased production rates and potential 

increases in ore sulfur content. On 

November 10, 2022, Northshore 

submitted hourly SO2 CEMS data for the 

period of January 16, 2017, through 

January 15, 2018, as requested by EPA, 

to allow for EPA’s independent 

calculation of emission limits. 

Using the equation set forth at 

52.1235(f)(2) and the hourly SO2 CEMS 

data from January 16, 2017 through 

January 15, 2018, EPA calculated an 

aggregate SO2 emission limit of 17.0 lbs 

SO2/hour for Furnaces 11 and 12.30

There is no basis in the FIP for adjusting 

emission limits to account for possible 

future production levels or possible 

higher ore sulfur content. Therefore, 

based on these data and as provided at 

40 CFR 52.1235(b)(2)(vi), EPA is 

proposing that an aggregate SO2

emission limit of 17.0 lbs SO2/hr for 

Northshore Furnaces 11 and 12, based 

on a 30-day rolling average, reflects SO2

BART for Northshore. 

IV. CAA Section 110(l) 

Under CAA section 110(l) (sometimes 

referred to as an ‘‘anti-backsliding’’ 

provision), EPA cannot approve a plan 

revision ‘‘if the revision would interfere 

with any applicable requirement 

concerning attainment and reasonable 

further progress (as defined in section 

7501 of this title), or any other 

applicable requirement of this chapter.’’ 

Based on the following analysis, we find 

that our revisions to the 2016 FIP are 

consistent with CAA section 110(l) 

because they will not interfere with any 

applicable requirement concerning 

attainment or reasonable further 

progress or any other applicable 

requirements of the CAA. 

A. NOX Emission Limits 

When the 2016 FIP was promulgated, 

NOX control technology had not yet 

been installed on the furnaces at Tilden, 

Hibbing, Minorca, and UTAC. 

Therefore, EPA established initial 

emission limitations based on the 

modeled (estimated) performance of the 

proposed technology along with a 

procedure to refine and modify the 

emission limits within a specified range 

based upon CEMS data collected after 

installation of the NOX control 

technology. The 2016 FIP also allowed 

for the establishment of a single NOX

limit for all fuels. However, the NOX

emission limits in the 2016 FIP are not 

enforceable and final until EPA takes 

action to confirm or modify the initial 

emission limits established in the 2016 

FIP. Because the NOX limits established 

in the 2016 FIP have not been confirmed 

and made enforceable through the 

procedures set forth in the 2016 FIP, 

and are not currently enforceable, the 

proposed NOX emission limits do not 

alter any existing enforceable limits, 

since there are no current enforceable 

limits. Therefore, approval of the 

proposed NOX limits would not 

interfere with any applicable 

requirement concerning attainment or 

reasonable further progress, or any other 

applicable requirement of the CAA. 

Additionally, even if EPA were to 

evaluate the proposed NOX emission 

limits in relation to the relevant 

provisions of the 2016 FIP, we believe 

the FIP will not interfere with any 

applicable requirement concerning 

attainment or reasonable further 

progress, or any other applicable 

requirements of the CAA.31 EPA’s 

proposed action will complete the 

process set forth in the 2016 FIP to 

finalize enforceable NOX emission 

limits for Tilden, Hibbing, UTAC, and 

Minorca within ranges previously 

established. The NOX emission limits 

EPA is proposing reflect BART because 

they were calculated using the corrected 

UPL equation and actual emission data 

recorded by CEMS, after installation of 

the required low-NOX technology, 

pursuant to the procedures set forth in 


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32 40 CFR part 51, appendix Y, at V. 

the 2016 FIP. While crossline averaging 

was not addressed in the 2016 FIP, 

under the BART Guidelines, a source 

may be permitted to ‘‘ ‘average’ 

emissions across any set of BARTeligible emission units within a 

fenceline, as 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 BARTeligible units that constitute BARTeligible sources.’’ 32 Based on EPA’s 

analysis, the crossline average emission 

limits proposed for Hibbing and UTAC 

are equal to the reductions that would 

be obtained by controlling each line 

separately. 

The proposed NOX emission limits do 

not reflect a change in EPA’s BART 

determination. Rather, the proposed 

limits were calculated using CEMS data 

and the corrected UPL equation, 

following the procedure set forth in the 

2016 FIP, to more accurately reflect an 

emission limit consistent with the 

actual emission reduction capabilities of 

the BART controls and within the 

natural gas ranges established in the 

2016 FIP. Therefore, there are no 

expected increases in NOX emissions 

compared to the ranges set in the 2016 

FIP. 

B. SO2 Emission Limits 

EPA is proposing to revise the SO2

emission limits applicable to Minorca, 

Northshore, and Tilden. Minorca and 

Northshore are straight-grate furnaces 

that do not co-fire with coal; SO2

emissions from these sources result 

from sulfur in the ore processed in the 

furnaces. As discussed previously, 

when the Original FIP was promulgated, 

SO2 BART for Minorca and Northshore 

was established as no further controls. 

EPA set initial SO2 emission limits 

based on limited stack test data and 

established a procedure to refine those 

limits when CEMS data became 

available. EPA is proposing to modify 

the Minorca emission limit from 38.16 

lbs SO2/hour to 68.2 lbs SO2/hour and 

the Northshore emission limit from 39.0 

lbs SO2/hour to 17.0 lbs SO2/hour. 

These proposed revised emission limits 

do not reflect a change in EPA’s BART 

determination or in operations at the 

facilities that would lead to an increase 

or decrease in SO2 emissions. Rather, 

the emission limits EPA is proposing 

establish emission limits that more 

accurately reflect BART because they 

were calculated using the corrected UPL 

equation and actual emission data 

recorded by CEMS, pursuant to the 

procedures set forth in the Original FIP. 

Similarly, the 2016 FIP established 

SO2 BART for Tilden as a limit on the 

sulfur content of the coal and no further 

controls, and set an SO2 emission limit 

for Tilden along with a process to 

modify that limit when CEMS data 

became available. EPA is not proposing 

to revise any limits on the sulfur content 

of coal at Tilden. EPA is only proposing 

to modify Tilden’s emissions limit from 

500 lbs SO2/hour to 189 lbs SO2/hour. 

The revised emission limit was 

calculated using the corrected UPL 

equation and actual emission data 

recorded by CEMS, pursuant to the 

procedures set forth in the 2016 FIP. 

In sum, as a result of the revised SO2

emissions limits described above, EPA 

does not expect changes in SO2

emissions from these sources. The limits 

do not reflect a change in EPA’s BART 

determination or in operations at the 

facilities. Rather, the proposed limits 

more accurately reflect actual emissions 

that were calculated using newly 

available CEMS data and the corrected 

UPL equation. 

C. Regional Haze SIPs 

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

approved Minnesota’s regional haze 

plan for the first implementation 

planning period as satisfying the 

applicable requirements in 40 CFR 

51.308, except for BART emission limits 

for the taconite facilities. Among the 

regional haze plan elements approved 

were 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. 

On December 3, 2012 (77 FR 71533), 

EPA approved Michigan’s regional haze 

plan for the first implementation 

planning period as satisfying the 

applicable requirements in 40 CFR 

51.308, except for BART emission limits 

for Tilden, St. Mary’s Cement, and 

Escanaba Paper Company. Among the 

regional haze plan elements approved 

was Michigan’s long-term strategy for 

making reasonable progress toward 

visibility goals. Michigan’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. 

On August 23, 2021, Michigan 

submitted a revision to their regional 

haze SIP for the second implementation 

planning period. Michigan’s submittal 

provided a long-term strategy and 

reasonable progress goals that included 

2028 emission projections for Tilden 

based on a 2016 modeling platform 

developed by LADCO that did not rely 

on emission limits or ranges in the 2016 

FIP. 

On December 20, 2022, Minnesota 

submitted a revision to its regional haze 

SIP for the second implementation 

period. Minnesota’s long-term strategy 

included implementation of the current 

applicable limits and ranges in the 

Original FIP and 2016 FIP for Hibbing, 

Minorca, UTAC, and Northshore. 

However, in applying the long-term 

strategy to develop its reasonable 

progress goals, Minnesota used 2028 

projected emissions modeling that 

relied on the 2016 FIP limits only for 

UTAC and not for Hibbing, Minorca, or 

Northshore. For Hibbing and Minorca, 

Minnesota’s modeling utilized 2028 

projected emissions provided by 

LADCO using the 2016 emissions 

modeling platform since CEMS data was 

not available at the time. For 

Northshore, Minnesota accounted for 

the facility being idled until 2031, 

which was incorporated into an 

enforceable agreement as an 

Administrative Order by Consent issued 

by the Minnesota Pollution Control 

Agency to Northshore and ClevelandCliffs, Inc. To project 2028 emissions for 

UTAC, Minnesota used 2017 CEMS data 

to convert NOX and SO2 emissions and 

associated heat input into emission rates 

that allowed for a comparison to the 

limits and ranges in the 2016 FIP. 

Minnesota kept heat input rates the 

same and assumed compliance at the 

least stringent end of the emission limit 

ranges (e.g., for an emission limit range 

of 2.8–3.0 lbs NOX/MMBtu, Minnesota 

assumed 3.0 lbs NOX/MMBtu in the 

emission calculations), resulting in 

conservative emission projections for 

2028. Using a photochemical model 

based on the 2028 emission projections 

for all selected sources in their regional 

haze plan, including the taconite 

facilities, Minnesota estimated future 

visibility and established their 

reasonable progress goals. 

Although EPA has not yet taken final 

action on the regional haze SIP revisions 

submitted by Michigan and Minnesota 

for the second implementation period, 

the assumptions used in the long-term 

strategies and reasonable progress goals 

were no more stringent than the 

currently applicable Original FIP and 

2016 FIP emission limits and ranges or 

the revised limits we are proposing in 

this action. Therefore, the revised NOX

emission limits for Tilden, Hibbing, 

UTAC, Minorca, and Northshore 

represent greater control overall than 

was assumed in Michigan’s and 

Minnesota’s long-term strategy and 

would not result in a degradation of the 

reasonable progress goals required by 40 

CFR 51.308(d)(1). 


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D. National Ambient Air Quality 

Standards (NAAQS) and Reasonable 

Further Progress 

With respect to requirements 

concerning attainment of the NAAQS 

and reasonable further progress, EPA is 

proposing to finalize NOX BART 

emission limits for seven subject-toBART units at four facilities within the 

ranges established in the 2016 FIP. EPA 

is also proposing to finalize SO2

emission limits for three facilities which 

will not result in an increase in SO2

emissions. Thus, the proposed FIP 

revision will not interfere with 

attainment and reasonable further 

progress requirements. 

E. Conclusion 

We find that these revisions are 

consistent with CAA section 110(l). The 

previous sections of the notice explain 

how the proposed FIP revision will 

comply with applicable regional haze 

requirements and general 

implementation plan requirements and 

demonstrate that it will not interfere 

with any regional haze program 

requirements, attainment and 

reasonable further progress, or any other 

requirement of the CAA. 

V. Environmental Justice 

Considerations 

Executive Order 12898 (59 FR 7629, 

February 16, 1994) directs Federal 

agencies, to the greatest extent 

practicable and permitted by law, to 

make environmental justice (EJ) part of 

their mission by identifying and 

addressing, as appropriate, 

disproportionately high and adverse 

human health or environmental effects 

of their programs, policies, and 

activities on communities with EJ 

concerns. 

EPA believes that the human health 

and environmental conditions that exist 

prior to this action do not result in 

disproportionate and adverse effects on 

communities with EJ concerns. To 

identify environmental burdens and 

susceptible populations in communities 

nearby the Tilden, Hibbing, Minorca, 

Northshore, and UTAC facilities, and to 

examine the implications of the 

proposed NOX and SO2 emission limits, 

EPA utilized the EJScreen tool to 

evaluate environmental and 

demographic indicators within a 3-mile 

buffer, a 10-mile buffer, and the county 

that each facility is located in 

(Marquette County, Michigan for Tilden; 

St. Louis County, Minnesota for 

Hibbing, Minorca, and UTAC; and Lake 

County, Minnesota for Northshore). 

EPA’s screening-level analysis 

indicates that communities near the 

facilities affected by this action score 

below the national average for the 

EJScreen ‘‘Demographic Index’’, which 

is the average of an area’s percent 

minority and percent low-income 

populations, i.e., the two demographic 

indicators explicitly named in Executive 

Order 12898. Additionally, the results 

indicate that these areas score below the 

80th percentile (in comparison to the 

nation as a whole) in the 13 EJ Indexes 

established by EPA, which include a 

combination of environmental and 

demographic information. EPA has 

provided that if any of the EJ indexes for 

the areas under consideration are at or 

above the 80th percentile nationally, 

then further review may be appropriate. 

As discussed in the EPA’s EJ technical 

guidance, communities with EJ 

concerns often experience greater 

exposure and disease burdens than the 

general population, which can increase 

their susceptibility to adverse health 

effects from environmental stressors. 

EPA believes that this action is not 

likely to result in new disproportionate 

and adverse effects on communities 

with EJ concerns. This action proposes 

to set final NOX and SO2 emission limits 

which are not expected to result in new 

or increased burdens on residents, 

including those in communities of EJ 

concern, as specified in Executive Order 

12898. 

EPA invited the identification of EJ 

and other concerns during its Tribal 

consultations which occurred prior to 

proposing emission limits for all five 

taconite facilities. No EJ concerns were 

raised in the context of this action. We 

have determined that this rulemaking 

will not have disproportionately high 

and adverse human health or 

environmental effects on communities 

with EJ concerns. The information 

supporting this Executive Order review 

is contained in the docket for this 

action, including the EJSCREEN reports 

considering a 3-mile buffer, a 10-mile 

buffer, and the county that each taconite 

facility is in. 

VI. Proposed Action 

EPA is proposing to modify the UPL 

equations used to establish NOX and 

SO2 emission limits and to finalize NOX

and/or SO2 limits for the indurating 

furnaces at five taconite facilities in 

accordance with the procedure set forth 

in the 2016 FIP. Specifically, EPA is 

proposing to approve the following NOX

limits, with compliance to be 

determined on a rolling 30-day average: 

3.0 lbs NOX/MMBtu for all fuels for 

Tilden Line 1; a crossline average limit 

of 1.5 lb NOX/MMBtu for Hibbing Lines 

1, 2, and 3; a crossline average emission 

limit of 3.0 lbs NOX/MMBtu for all fuels 

for UTAC Lines 1 and 2; and 1.6 lbs 

NOX/MMBtu for Minorca’s indurating 

furnace. EPA is proposing to approve 

the following SO2 limits, with 

compliance to be determined on a 

rolling 30-day average: 189 lbs SO2/hr 

for all fuels for Tilden Line 1; an 

aggregate emission limit of 247.8 lbs 

SO2/hr for Hibbing Lines 1, 2, and 3; 

68.2 lbs SO2/hr for Minorca’s indurating 

furnace; and an aggregate limit of 17.0 

lbs SO2/hr for Northshore Furnaces 11 

and 12. 

VII. Statutory and Executive Order 

Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 14094: Modernizing Regulatory 

Review 

This action is not a significant 

regulatory action as defined in 

Executive Order 12866, as amended by 

Executive Order 14094, and was 

therefore not subject to a requirement 

for Executive Order 12866 review. 

B. Paperwork Reduction Act 

This proposed action does not impose 

an information collection burden under 

the provisions of the Paperwork 

Reduction Act, 44 U.S.C. 3501 et seq. 

Because the FIP applies to just the 

taconite facilities in Michigan and 

Minnesota, the Paperwork Reduction 

Act does not apply. See 5 CFR 1320.3(c). 

C. Regulatory Flexibility Act 

I certify that this proposed action will 

not have a significant economic impact 

on a substantial number of small entities 

under the RFA. This proposed action 

will not impose any requirements on 

small entities. This action, if finalized, 

will add additional controls to certain 

sources. None of these sources are 

owned by small entities, and therefore 

are not small entities. 

D. Unfunded Mandates Reform Act 

(UMRA) 

This proposed action does not contain 

any unfunded mandate as described in 

UMRA, 2 U.S.C. 1531–1538, and does 

not significantly or uniquely affect small 

governments. The proposed action 

imposes no enforceable duty on any 

state, local or Tribal governments or the 

private sector. 

E. Executive Order 13132: Federalism 

This proposed 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. 


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F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

This proposed action does not have 

Tribal implications, as specified in 

Executive Order 13175. It will not have 

substantial direct effects on Tribal 

governments. Thus, Executive Order 

13175 does not apply to this action. 

Consistent with the EPA Policy on 

Consultation and Coordination with 

Indian Tribes, EPA did discuss this 

action in conference calls with the 

Michigan and Minnesota Tribes. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

This action is not subject to Executive 

Order 13045 because it is not 3(f)(1) 

significant as defined in Executive 

Order 12866, and because EPA does not 

believe the environmental health or 

safety risks addressed by this action 

present a disproportionate risk to 

children. To the extent this action, if 

finalized, will limit emissions of NOX

and SO2 emissions, the rule will have a 

beneficial effect on children’s health by 

reducing air pollution. 

H. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This action is not subject to Executive 

Order 13211 (66 FR 28355, May 22, 

2001), because it is not a significant 

regulatory action under Executive Order 

12866. 

I. National Technology Transfer and 

Advancement Act 

This rulemaking does not involve 

technical standards. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations and Executive 

Order 14096: Revitalizing Our Nation’s 

Commitment to Environmental Justice 

for All 

EPA believes that the human health 

and environmental conditions that exist 

prior to this action do not result in 

disproportionate and adverse effects on 

communities with Environmental 

Justice concerns. This proposed FIP 

limits emissions of NOX and SO2 from 

five taconite facilities in Michigan and 

Minnesota. EPA believes that this action 

is not likely to result in new 

disproportionate and adverse effects on 

communities with environmental justice 

concerns. 

EPA performed an EJ analysis, as is 

described above in the section titled, 

‘‘Environmental Justice 

Considerations.’’ The analysis was done 

for the purpose of providing additional 

context and information about this 

rulemaking to the public, not as a basis 

of the action. Due to the nature of the 

action being taken here, this action is 

expected to have a neutral to positive 

impact on the air quality of the affected 

area. In addition, there is no information 

in the record upon which this decision 

is based inconsistent with the stated 

goal of E.O. 12898 of achieving EJ for 

communities with EJ concerns. 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Incorporation by 

reference, Intergovernmental relations, 

Nitrogen dioxide, Regional haze, 

Reporting and recordkeeping 

requirements, Sulfur oxides. 

Michael S. Regan, 

Administrator. 

For the reasons stated in the 

preamble, EPA proposes to amend 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. Section 52.1183 is amended by: 

■ a. in paragraph (k) revising (1), (3), (4) 

and (5); 

■ b. in paragraph (l) revising (3), (4)(v) 

and (4)(xii); 

■ c. in paragraph (n) revising (1) and (2); 

and 

■ d. removing and reserving paragraph 

(p). 

The revisions read as follows: 

§ 52.1183 Visibility protection. 

* * * * * 

(k) Tilden Mining Company, or any 

subsequent owner/operator of the 

Tilden Mining Company facility in 

Ishpeming, Michigan, shall meet the 

following requirements: 

(1) NOX Emission Limits. 

(i) An emission limit of 3.0 lbs NOX/ 

MMBTU, based on a 30-day rolling 

average, shall apply to Tilden Grate Kiln 

Line 1 (EUKILN1) beginning January 3, 

2025. 

(ii) Compliance with this emission 

limit shall be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for NOX. 

(2) SO2 Emission Limits. * * * 

(3) The owner or operator of the 

Tilden Grate Kiln Line 1 (EUKILN1) 

furnace shall meet an emission limit of 

189.0 lbs SO2/hr, based on a 30-day 

rolling average, beginning on January 3, 

2025. Compliance with this emission 

limit shall be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for SO2. 

Beginning November 12, 2016, any coal 

burned on Tilden Grate Kiln Line 1 

shall have no more than 0.60 percent 

sulfur by weight based on a monthly 

block average. The sampling and 

calculation methodology for 

determining the sulfur content of coal 

must be described in the monitoring 

plan required for this furnace. 

(4) Emissions resulting from the 

combustion of fuel oil are not included 

in the calculation of the 30-day rolling 

average. However, if any fuel oil is 

burned after the first day that SO2 CEMS 

are required to be operational, then the 

information specified in (k)(5) must be 

submitted, for each calendar year, to the 

Regional Administrator at 

R5ARDReporting@epa.gov no later than 

30 days after the end of each calendar 

year so that a limit can be set. 

(5) Records shall be kept for any day 

during which fuel oil is burned as fuel 

(either alone or blended with other 

fuels) in Grate Kiln Line 1. These 

records must include, at a minimum, 

the gallons of fuel oil burned per hour, 

the sulfur content of the fuel oil, and the 

SO2 emissions in pounds per hour. If 

any fuel oil is burned after the first day 

that SO2 CEMS are required to be 

operational, then the records must be 

submitted, for each calendar year, to the 

Regional Administrator at 

R5ARDReporting@epa.gov no later than 

30 days after the end of each calendar 

year. 

(l) Testing and monitoring. 

* * * 

(3) The owner or operator shall 

install, certify, calibrate, maintain, and 

operate one or more continuous diluent 

monitor(s) (O2 or CO2) and continuous 

stack gas flow rate monitor(s) on Tilden 

Grate Kiln Line 1 to allow conversion of 

the NOX and SO2 concentrations to 

units of the standard (lbs/MMBTU and 

lbs/hr, respectively) unless a 

demonstration is made that a diluent 

monitor and/or continuous flow rate 

monitor are not needed for the owner or 

operator to demonstrate compliance 

with applicable emission limits in units 

of the standard. 

(4) * * * 

* * * * * 

(v) The owner or operator of each 

CEMS must furnish the Regional 

Administrator a written report of the 

results of each quarterly performance 

evaluation and a data accuracy 

assessment pursuant to 40 CFR part 60 

appendix F within 60 days after the 

calendar quarter in which the 


ddrumheller on DSK120RN23PROD with PROPOSALS1
96164 Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 

performance evaluation was completed. 

These reports shall be submitted to the 

Regional Administrator at 

R5AirEnforcement@epa.gov. 

* * * * * 

(xii) Data substitution must not be 

used for purposes of determining 

compliance under this regulation. If 

CEMS data is measuring only a portion 

of the NOX or SO2 emitted during 

startup, shutdown, or malfunction 

conditions, the CEMS data may be 

supplemented, but not modified, by the 

addition of calculated emission rates 

using procedures set forth in the site 

specific monitoring plan. 

* * * * * 

(n) Reporting requirements. 

(1) Unless instructed otherwise, all 

requests, reports, submittals, 

notifications, and other communications 

required by this section shall be 

submitted to the Regional Administrator 

at R5AirEnforcement@epa.gov. 

References in this section to the 

Regional Administrator shall mean the 

EPA Regional Administrator for Region 

5. 

(2) The owner or operator of each 

BART affected unit identified in this 

section and CEMS required by this 

section must provide to the Regional 

Administrator the written notifications, 

reports, and plans identified at 

paragraphs (n)(2)(i) through (viii) of this 

section. 

* * * 

* * * * * 

(p) [Reserved] 

* * * * * 

■ 3. Section 52.1235 is amended by: 

■ a. in paragraph (b) revising (1)(ii), 

(1)(iv), (1)(v), (1)(vi), (2)(ii), (2)(v) and 

(2)(vi); 

■ b. in paragraph (c) revising (1), (2), (3), 

(4)(ii), (4)(v), and (4)(xii); and 

■ c. in paragraph (e) revising (1) and (2); 

and 

■ d. revising paragraph (f). 

The revisions read as follows: 

§ 52.1235 Regional haze. 

* * * * * 

(b) * * * 

(1) NOX emission limits. 

(i) * * * 

(ii) Hibbing Taconite Company 

(A) An aggregate emission limit of 1.5 

lbs NOX/MMBtu, based on a 30-day 

rolling average, shall apply to the 

combined NOX emissions from the three 

indurating furnaces, Line 1 (EU020), 

Line 2 (EU021), and Line 3 (EU022), 

beginning on January 3, 2025. To 

determine the aggregate emission rate, 

the combined NOX emissions from 

Lines 1, 2, and 3 shall be divided by the 

total heat input to the three lines (in 

MMBtu) during every rolling 30-day 

period. 

(B) Compliance with this emission 

limit shall be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for NOX. 

(iii) * * * 

(iv) United Taconite 

(A) An aggregate emission limit of 3.0 

lbs NOX/MMBtu, based on a 30-day 

rolling average, shall apply to the 

combined NOX emissions from the two 

indurating furnaces, Grate Kiln Line 1 

(EU040) and Grate Kiln Line 2 (EU042), 

beginning on January 3, 2025. To 

determine the aggregate emission rate, 

the combined NOX emissions from Grate 

Kiln Line 1 and Grate Kiln Line 2 shall 

be divided by the total heat input to the 

two lines (in MMBtu) during every 

rolling 30-day period. 

(B) Compliance with this emission 

limit shall be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for NOX. 

(v) Minorca Mine 

(A) An emission limit of 1.6 lbs NOX/ 

MMBtu, based on a 30-day rolling 

average, shall apply to the Minorca 

Mine indurating furnace (EU026). This 

emission limit will become enforceable 

on January 3, 2025. 

(B) Compliance with this emission 

limit will be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for NOX. 

(vi) Northshore Mining Company— 

Silver Bay: An emission limit of 1.5 lbs 

NOX/MMBtu, based on a 30-day rolling 

average, shall apply to Furnace 11 

(EU100/EU104) beginning October 10, 

2018. An emission limit of 1.5 lbs NOX/ 

MMBtu, based on a 30-day rolling 

average, shall apply to Furnace 12 

(EU110/114) beginning October 11, 

2019. However, for any 30, or more, 

consecutive days when only natural gas 

is used at either Northshore Mining 

Furnace 11 or Furnace 12, a limit of 1.2 

lbs NOX/MMBtu, based on a 30-day 

rolling average, shall apply. An 

emission limit of 0.085 lbs NOX/ 

MMBtu, based on a 30-day rolling 

average, shall apply to Process Boiler #1 

(EU003) and Process Boiler #2 (EU004) 

beginning October 10, 2021. The 0.085 

lbs NOX/MMBtu emission limit for each 

process boiler applies at all times a unit 

is operating, including periods of startup, shut-down and malfunction. 

(2) SO2 Emission Limits. 

(i) * * * 

(ii) Hibbing Taconite Company 

(A) An aggregate emission limit of 

247.8 lbs SO2/hour, based on a 30-day 

rolling average, shall apply to the 

combined SO2 emissions from the three 

indurating furnaces, Line 1 (EU020), 

Line 2 (EU0021), and Line 3 (EU022), 

beginning on February 10, 2017. To 

determine the aggregate emission rate, 

the combined SO2 emissions from Lines 

1, 2, and 3 shall be divided by the total 

hours of operation of the three lines 

during every rolling 30-day period. 

(B) Compliance with this emission 

limit shall be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for SO2. 

(C) Emissions resulting from the 

combustion of fuel oil are not included 

in the calculation of the 30-day rolling 

average. However, if any fuel oil is 

burned after the first day that SO2 CEMS 

are required to be operational, then the 

information specified in (b)(2)(vii) must 

be submitted, for each calendar year, to 

the Regional Administrator at 

R5ARDReporting@epa.gov no later than 

30 days after the end of each calendar 

year so that a limit can be set. 

(iii) * * * 

(iv) * * * 

(v) Minorca Mine 

(A) An emission limit of 68.2 lbs SO2/ 

hr, based on a 30-day rolling average, 

shall apply to the indurating furnace 

(EU026) beginning January 3, 2025. 

(B) Compliance with this emission 

limit shall be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for SO2. 

(C) Emissions resulting from the 

combustion of fuel oil are not included 

in the calculation of the 30-day rolling 

average. However, if any fuel oil is 

burned after the first day that SO2 CEMS 

are required to be operational, then the 

information specified in (b)(2)(vii) must 

be submitted, for each calendar year, to 

the Regional Administrator at 

R5ARDReporting@epa.gov no later than 

30 days after the end of each calendar 

year so that a limit can be set. 

(vi) Northshore Mining Company— 

Silver Bay 

(A) An aggregate emission limit of 

17.0 lbs SO2/hr, based on a 30-day 

rolling average, shall apply to Furnace 

11 (EU100/EU104) and Furnace 12 

(EU110/EU114) beginning January 3, 

2025. To determine the aggregate 

emission rate, the combined SO2

emissions from Furnace 11 and Furnace 

12 shall be divided by the total hours of 

operation of the two furnaces during 

every rolling 30-day period. 

(B) Compliance with these emission 

limits shall be demonstrated with data 

collected by a continuous emissions 

monitoring system (CEMS) for SO2. 

(C) Emissions resulting from the 

combustion of fuel oil are not included 

in the calculation of the 30-day rolling 

average. However, if any fuel oil is 

burned after the first day that SO2 CEMS 

are required to be operational, then the 

information specified in (b)(2)(vii) must 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 96165 

be submitted, for each calendar year, to 

the Regional Administrator at 

R5ARDReporting@epa.gov no later than 

30 days after the end of each calendar 

year so that a limit can be set. 

(D) The owner or operator may submit 

to EPA for approval an alternative 

monitoring procedure request. The 

request shall include at least one year of 

CEMS data demonstrating consistent 

values at or below 5 lbs SO2/hr. The 

alternative monitoring procedure 

request shall not remove the obligation 

to maintain and operate a flow rate 

monitor in the stack. If approved, the 

owner or operator would not be 

required to operate the SO2 CEMS and 

may demonstrate continuous 

compliance using an emission factor 

derived from the average of at least one 

year of existing SO2 data using the 

procedure set forth in the site specific 

monitoring plan, and verified by annual 

stack tests using EPA approved test 

methods, multiplied by the daily 

measured flow rate as recorded by the 

flow rate monitor and recorded as the 

daily lb/hr SO2 emission rate. 

(vii) * * * 

(c) Testing and monitoring. 

(1) The owner or operator of the 

respective facility shall install, certify, 

calibrate, maintain and operate 

continuous emissions monitoring 

systems (CEMS) for NOX on United 

States Steel Corporation, Keetac unit 

EU030; Hibbing Taconite Company 

units EU020, EU021, and EU022; United 

States Steel Corporation, Minntac units 

EU225, EU261, EU282, EU315, and 

EU334; United Taconite units EU040 

and EU042; Minorca Mine unit EU026; 

and Northshore Mining Company-Silver 

Bay units Furnace 11 (EU100/EU104) 

and Furnace 12 (EU110/EU114). 

Compliance with the emission limits for 

NOX shall be determined using data 

from the CEMS. 

(2) The owner or operator shall 

install, certify, calibrate, maintain, and 

operate CEMS for SO2 on United States 

Steel Corporation, Keetac unit EU030; 

Hibbing Taconite Company units 

EU020, EU021, and EU022; United 

States Steel Corporation, Minntac units 

EU225, EU261, EU282, EU315, and 

EU334; United Taconite units EU040 

and EU042; Minorca Mine unit EU026; 

and Northshore Mining Company-Silver 

Bay units Furnace 11 (EU100/EU104) 

and Furnace 12 (EU110/EU114). 

(3) The owner or operator shall 

install, certify, calibrate, maintain, and 

operate one or more continuous diluent 

monitor(s) (O2 or CO2) and continuous 

stack gas flow rate monitor(s) on the 

BART affected units to allow conversion 

of the NOX and SO2 concentrations to 

units of the standard (lbs/MMBTU and 

lbs/hr, respectively) unless a 

demonstration is made that a diluent 

monitor and/or continuous flow rate 

monitor are not needed for the owner or 

operator to demonstrate compliance 

with applicable emission limits in units 

of the standards. 

(4) * * * 

(i) * * * 

(ii) CEMS must be installed and 

operational such that the operational 

status of the CEMS identified in 

paragraphs (c)(1) and (2) of this section 

shall be verified by, as a minimum, 

completion of the manufacturer’s 

written requirements or 

recommendations for installation, 

operation, and calibration of the 

devices. 

* * * * * 

(v) The owner or operator of each 

CEMS must furnish the Regional 

Administrator a written report of the 

results of each quarterly performance 

evaluation and a data accuracy 

assessment pursuant to 40 CFR part 60 

appendix F within 60 days after the 

calendar quarter in which the 

performance evaluation was completed. 

These reports shall be submitted to the 

Regional Administrator at 

R5AirEnforcement@epa.gov. 

* * * * * 

(xii) Data substitution must not be 

used for purposes of determining 

compliance under this section. If CEMS 

data is measuring only a portion of the 

NOX or SO2 emitted during startup, 

shutdown, or malfunction conditions, 

the CEMS data may be supplemented, 

but not modified, by the addition of 

calculated emission rates using 

procedures set forth in the site specific 

monitoring plan. 

* * * 

* * * * * 

(e) Reporting Requirements 

(1) Unless instructed otherwise, all 

requests, reports, submittals, 

notifications, and other communications 

required by this section shall be 

submitted to the Regional Administrator 

at R5AirEnforcement@epa.gov. 

References in this section to the 

Regional Administrator shall mean the 

EPA Regional Administrator for Region 

5. 

(2) The owner or operator of each 

BART affected unit identified in this 

section and CEMS required by this 

section must provide to the Regional 

Administrator the written notifications, 

reports and plans identified at 

paragraphs (e)(2)(i) through (viii) of this 

section. 

* * * 

* * * * * 

(f) Equations for establishing the 

upper predictive limit— 

(1) Equation for normal distribution 

and statistically independent data. 

Where: 

x = average or mean of hourly test run data; 

t[(n¥1),(0.99)] = t score, the one-tailed t value of 

the Student’s t distribution for a specific 

degree of freedom (n¥1) and a 

confidence level (0.99, to reflect the 99th 

percentile) 

s2 = variance of the hourly data set; 

n = number of values (e.g., 5,760 if 8 months 

of valid lbs NOX/MMBTU hourly values) 

m = number of values used to calculate the 

test average (m = 720 as per averaging 

time) 

(i) To determine if statistically 

independent, use the Rank von 

Neumann Test on p. 137 of data Quality 

Assessment: Statistical Methods for 

Practitioners EPA QA/G–9S. 

(ii) Alternative to Rank von Neumann 

test to determine if data are dependent, 

data are dependent if t test value is 

greater than t critical value, where: 

ρ = correlation between data points 

t critical = t[(n¥2),(0.95)] = t score, the twotailed t value of the Student’s t 

distribution for a specific degree of 

freedom (n¥2) and a confidence level 

(0.95) 

(iii) The Anderson-Darling normality 

test is used to establish whether the data 

are normally distributed. That is, a 

distribution is considered to be 

normally distributed when p > 0.05. 

(2) Non-parametric equation for data 

not normally distributed and normally 

distributed but not statistically 

independent. 

m = (n+1) * a 

m = the rank of the ordered data point, when 

data are sorted smallest to largest. The 

data points are 720-hour averages for 

establishing NOX limits. 

n = number of data points (e.g., 5040 720- 

hourly averages for eight months of valid 

NOX lbs/MMBTU values) 

a = 0.99, to reflect the 99th percentile 

If m is a whole number, then the 

limit, UPL, shall be computed as: 

UPL = Xm

Where: 

Xm = value of the mth data point in terms of 

lbs SO2/hr or lbs NOX/MMBtu, when the 

data are sorted smallest to largest. 

If m is not a whole number, the limit 

shall be computed by linear 

interpolation according to the following 

equation. 


ddrumheller on DSK120RN23PROD with PROPOSALS1EP04DE24.035</GPH> EP04DE24.036</GPH>

UP L = X + t[(n-1),(0.99)]✓ 5 2 (.!. n + 2.) m 

p 

t test = ji-p2 

n-2 
96166 Federal Register / Vol. 89, No. 233 / Wednesday, December 4, 2024 / Proposed Rules 

UPL = xm = xmi·md= xmi + 0.md(xm(i+1) ¥ 

xmi

) 

Where: 

mi = the integer portion of m, i.e., m 

truncated at zero decimal places, and 

md = the decimal portion of m 

[FR Doc. 2024–27635 Filed 12–3–24; 8:45 am] 

BILLING CODE 6560–50–P 

FEDERAL COMMUNICATIONS 

COMMISSION 

47 CFR Part 54 

[WC Docket Nos. 10–90, 23–328, 16–271, 

14–58, 09–197; WT Docket No. 10–208; FCC 

24–116; FR ID 264716] 

Connect America Fund, Alaska 

Connect Fund, Connect America 

Fund—Alaska Plan, ETC Annual 

Reports and Certifications, 

Telecommunications Carriers Eligible 

To Receive Universal Service Support, 

Universal Service Reform—Mobility 

Fund 

AGENCY: Federal Communications 

Commission. 

ACTION: Proposed rule. 

SUMMARY: In this document, the Federal 

Communications Commission (FCC or 

Commission) adopted a Further Notice 

of Proposed Rulemaking (FNPRM) that 

seeks comment on the implementation 

of the Alaska Connect Fund (ACF) for 

mobile service from the period January 

1, 2030 through December 31, 2034 for 

areas where more than one mobile 

provider had been receiving support for 

overlapping service areas, or duplicatesupport areas (ACF Mobile Phase II). 

This includes comment on the 

methodology to determine support 

amounts in duplicate-support areas and 

the competitive or alternative 

mechanism to distribute support, which 

would result in support to a single 

mobile provider in duplicate-support 

areas after ACF Mobile Phase I (mobile 

support provided from January 1, 2027 

to December 31, 2029) ends. The 

Commission also seeks comment on 

how to distribute support in unserved 

areas, Tribal consent requirements for 

the ACF, and other additional issues 

that would impact the ACF. 

DATES: Comments are due on or before 

February 3, 2025, and reply comments 

are due on or before March 4, 2025. 

ADDRESSES: You may submit comments, 

identified by WC Docket Nos. 10–90, 

23–328, 16–271, 14–58, 09–197 or WT 

Docket No. 10–208 by any of the 

following methods: 

• Electronic Filers: Comments may be 

filed electronically using the internet by 

accessing the Electronic Comment 

Filing System (ECFS): https://

www.fcc.gov/ecfs/. 

• Paper Filers: Parties who choose to 

file by paper must file an original and 

one copy of each filing. 

• Filings can be sent by hand or 

messenger delivery, by commercial 

courier, or by the U.S. Postal Service. 

All filings must be addressed to the 

Secretary, Federal Communications 

Commission. 

• Hand-delivered or messengerdelivered paper filings for the 

Commission’s Secretary are accepted 

between 8:00 a.m. and 4:00 p.m. by the 

FCC’s mailing contractor at 9050 

Junction Drive, Annapolis Junction, MD 

20701. All hand deliveries must be held 

together with rubber bands or fasteners. 

Any envelopes and boxes must be 

disposed of before entering the building. 

• Commercial courier deliveries (any 

deliveries not by the U.S. Postal Service) 

must be sent to 9050 Junction Drive, 

Annapolis Junction, MD 20701. 

• Filings sent by U.S. Postal Service 

First-Class Mail, Priority Mail, and 

Priority Mail Express must be sent to 45 

L Street NE, Washington, DC 20554. 

People with Disabilities. To request 

materials in accessible formats for 

people with disabilities (braille, large 

print, electronic files, audio format), 

send an email to fcc504@fcc.gov or call 

the Consumer & Governmental Affairs 

Bureau at 202–418–0530 (voice), 202– 

418–0432 (tty). 

FOR FURTHER INFORMATION CONTACT: For 

further information, please contact, Matt 

Warner, Competition and Infrastructure 

Policy Division, Wireless 

Telecommunications Bureau, at 

Matthew.Warner@fcc.gov or (202) 418– 

2419. 

SUPPLEMENTARY INFORMATION: This is a 

summary of the Commission’s FNPRM 

in WC Docket Nos. 10–90, 23–328, 16– 

271, 14–58, 09–197 and WT Docket No. 

10–208; FCC 24–116, adopted on 

November 1, 2024 and released on 

November 4, 2024. The full text of this 

document is available at the following 

internet address: https://www.fcc.gov/ 

document/fcc-adopts-alaska-connectfund-further-address-broadband-needs. 

The Commission also concurrently 

adopted a Report and Order (Order) that 

takes important and necessary steps to 

ensure continued support for the 

advancement of modern mobile and 

fixed broadband service in Alaska. 

Filing Requirements. Pursuant to 

§§ 1.415 and 1.419 of the Commission’s 

rules, 47 CFR 1.415, 1.419, interested 

parties may file comments and reply 

comments on or before the dates 

indicated in this document. Comments 

may be filed using the Commission’s 

ECFS or by paper. All filings must be 

addressed to the Commission’s 

Secretary, Office of the Secretary, 

Federal Communications Commission. 

Ex Parte Rules. This proceeding shall 

be treated as a ‘‘permit-but-disclose’’ 

proceeding in accordance with the 

Commission’s ex parte rules. Persons 

making ex parte presentations must file 

a copy of any written presentation or a 

memorandum summarizing any oral 

presentation within two business days 

after the presentation (unless a different 

deadline applicable to the Sunshine 

period applies). Persons making oral ex 

parte presentations are reminded that 

memoranda summarizing the 

presentation must: (1) list all persons 

attending or otherwise participating in 

the meeting at which the ex parte 

presentation was made, and (2) 

summarize all data presented and 

arguments made during the 

presentation. If the presentation 

consisted in whole or in part of the 

presentation of data or arguments 

already reflected in the presenter’s 

written comments, memoranda, or other 

filings in the proceeding, the presenter 

may provide citations to such data or 

arguments in his or her prior comments, 

memoranda, or other filings (specifying 

the relevant page and/or paragraph 

numbers where such data or arguments 

can be found) in lieu of summarizing 

them in the memorandum. Documents 

shown or given to Commission staff 

during ex parte meetings are deemed to 

be written ex parte presentations and 

must be filed consistent with Rule 

1.1206(b), 47 CFR 1.1206(b). 

Participants in this proceeding should 

familiarize themselves with the 

Commission’s ex parte rules. 

Providing Accountability Through 

Transparency Act. Consistent with the 

Providing Accountability Through 

Transparency Act, Public Law 118–9, a 

summary of the FNPRM is available on 

https://www.fcc.gov/proposedrulemakings. 

Synopsis 

I. Further Notice of Proposed 

Rulemaking 

In this FNPRM, the Commission seeks 

comment on a number of issues related 

to the implementation of the ACF. 

As an initial matter, for ACF Mobile 

Phase II, the Commission seeks 

comment on a methodology to 

determine a support amount for areas 

where more than one mobile provider 

had been receiving support for 

overlapping service areas. This 

mechanism may also be used to 

determine support amounts to claw 


ddrumheller on DSK120RN23PROD with PROPOSALS1