14604 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

1 76 FR 64186. 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R06–OAR–2008–0727; FRL–9637–4] 

Approval and Promulgation of 

Implementation Plans; Arkansas; 

Regional Haze State Implementation 

Plan; Interstate Transport State 

Implementation Plan To Address 

Pollution Affecting Visibility and 

Regional Haze 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: The EPA is partially 

approving and partially disapproving a 

revision to the Arkansas State 

Implementation Plan (SIP) intended to 

address the regional haze (RH) 

requirements of the Clean Air Act (CAA 

or Act). In addition, EPA is partially 

approving and partially disapproving 

the portion of the Arkansas Interstate 

Transport SIP submittal that addresses 

the visibility requirement of section 

110(a)(2)(D)(i)(II) for the 1997 8-hour 

ozone and 1997 fine particulate matter 

(PM2.5) national ambient air quality 

standards (NAAQS) that the Arkansas 

SIP contain adequate provisions to 

prohibit emissions from interfering with 

measures required in another state to 

protect visibility. EPA is approving 

certain core elements of the RH SIP 

including: identification of affected 

Class I areas; determination of baseline 

and natural visibility conditions; 

determination of Uniform Rate of 

Progress (URP); reasonable progress goal 

(RPG) consultation and long term 

strategy (LTS) consultation; 

coordination of RH and reasonably 

attributable visibility impairment 

(RAVI); regional haze monitoring 

strategy and other SIP requirements 

under 40 CFR 51.308(d)(4); commitment 

to submit periodic regional haze SIP 

revisions and periodic progress reports 

describing progress towards the RPGs; 

commitment to make a determination of 

the adequacy of the existing SIP at the 

time a progress report is submitted; and 

consultation and coordination with 

Federal land managers (FLMs). EPA is 

partially approving and partially 

disapproving portions of other core 

elements of the SIP including: 

identification of best available retrofit 

technology (BART) eligible sources and 

subject to BART sources; requirements 

for BART; Chapter 15 of the Air 

Pollution Control and Ecology 

Commission (APCEC) Regulation No. 

19, also known as the State’s RH Rule; 

and the LTS. EPA is disapproving 

Arkansas’s reasonable progress goals 

(RPGs) required under 40 CFR 

51.308(d)(1). This action is being taken 

under section 110 and part C of the 

CAA. 

DATES: This final rule is effective on 

April 11, 2012. 

ADDRESSES: EPA has established a 

docket for this action under Docket ID 

No. EPA–R06–OAR–2008–0727. All 

documents in the docket are listed in 

the Federal e-Rulemaking portal index 

at http://www.regulations.gov and are 

available either electronically at http:// 

www.regulations.gov or in hard copy at 

EPA Region 6, 1445 Ross Ave., Dallas, 

TX 75202–2733. To inspect the hard 

copy materials, please schedule an 

appointment during normal business 

hours with the contact listed in the FOR

FURTHER INFORMATION CONTACT section. 

A reasonable fee may be charged for 

copies. 

FOR FURTHER INFORMATION CONTACT: Ms. 

Dayana Medina, Air Planning Section 

(6PD–L), Environmental Protection 

Agency, Region 6, 1445 Ross Avenue, 

Suite 700, Dallas, Texas 75202–2733, 

telephone 214–665–7241; fax number 

214–665–7263; email address 

medina.dayana@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this document wherever 

‘‘we,’’ ‘‘us,’’ ‘‘our,’’ or ‘‘the Agency’’ is 

used, we mean the EPA. 

Overview 

The CAA requires that states develop 

and implement SIPs to reduce the 

pollution that causes visibility 

impairment over a wide geographic 

area, known as Regional Haze (RH). 

CAA sections 110(a) and 169A. 

Arkansas submitted a RH plan to us on 

September 23, 2008, and August 3, 

2010, and submitted supplemental 

information on September 27, 2011. On 

October 17, 2011, we proposed to 

partially approve and partially 

disapprove certain elements of 

Arkansas’s SIP.1 Today, we are taking 

final action by partially approving and 

partially disapproving the elements of 

Arkansas’s RH SIP addressed in our 

proposed rule. 

In addition to the RH requirements, 

CAA section 110(a)(2)(D)(i)(II) requires 

that the Arkansas SIP ensure that 

emissions from sources within Arkansas 

do not interfere with the SIP of any 

other state under part C of the CAA to 

protect visibility. This requirement is 

commonly referred to as the visibility 

prong of ‘‘interstate transport,’’ which is 

also called the ‘‘good neighbor’’ 

provision of the CAA. Arkansas 

submitted a SIP to meet the 

requirements of interstate transport for 

the 1997 8-hour ozone and PM2.5

NAAQS on April 2, 2008, and 

supplemented it on September 27, 2011. 

On October 17, 2011, we proposed to 

partially approve and partially 

disapprove this submission as it relied 

upon the State’s RH Rule that we were 

proposing to partially approve and 

partially disapprove. Id. Because the 

Interstate Transport SIP is conditioned 

upon the BART determinations in the 

RH SIP, we are also taking final action 

by partially approving and partially 

disapproving elements of Arkansas’s 

Interstate Transport SIP addressed in 

our proposed rule. 

Arkansas submitted Chapter 15 of 

APCEC Regulation No. 19, its State RH 

Rule that addresses Arkansas’s RH 

program, to address the requirements in 

both its RH SIP and its Interstate 

Transport SIP. In both the RH SIP and 

the Interstate Transport SIP, Arkansas 

adopted BART emission limits for 

certain sources to meet the requirements 

of both SIPs as stated in the State RH 

Rule. Based upon public comment, we 

are disapproving the portion of the 

BART compliance provision found in 

the State’s RH Rule, Chapter 15 of 

APCEC Regulation No. 19, at Reg. 

19.1504 (B), which requires each source 

subject to BART to install and operate 

BART no later than six years after the 

effective date of Arkansas’s RH Rule for 

both the RH SIP and the Interstate 

Transport SIP. Because of this 

disapproval, compliance with 

Arkansas’s BART emission limitations 

is within five years of approval of 

Arkansas RH SIP by EPA. 

For a RH SIP, the process of 

establishing BART emission limitations 

can be logically broken down into three 

steps. First, states identify those sources 

which meet the definition of ‘‘BART 

eligible source’’ set forth in 40 CFR 

51.301. Second, states determine 

whether such sources ‘‘emit any air 

pollutant which may reasonably be 

anticipated to cause or contribute to any 

impairment of visibility in any such 

area’’ (a source which fits this 

description is ‘‘subject to BART’’). 

Third, for each source subject to BART, 

states then identify the appropriate type 

and the level of control for reducing 

emissions by conducting a five-step 

analysis: Step 1: Identify All Available 

Retrofit Control Technologies, Step 2: 

Eliminate Technically Infeasible 

Options, Step 3: Evaluate Control 

Effectiveness of Remaining Control 

Technologies, Step 4: Evaluate Impacts 

and Document the Results, and Step 5: 

Evaluate Visibility Impacts. 


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We agree with Arkansas’s 

identification of sources that are BART 

eligible, with the exception of the 6A 

Boiler at the Georgia-Pacific Crossett 

Mill, which we find to be BART eligible. 

We also agree with Arkansas’s 

identification of subject to BART 

sources, with the exception of the 6A 

and 9A Boilers at the Georgia-Pacific 

Crossett Mill, which we find to be 

subject to BART. In addition, we are 

approving a number of BART 

determinations from Arkansas’s RH SIP. 

We are not able to approve the following 

BART determinations made by 

Arkansas: the sulfur dioxide (SO2), 

nitrogen dioxide (NOX), and particulate 

matter (PM) BART determinations for 

the Arkansas Electric Cooperative 

Corporation (AECC) Bailey Plant Unit 1 

and the AECC McClellan Plant Unit 1; 

the SO2 and NOX BART determinations 

for the American Electric Power (AEP) 

Flint Creek Plant Boiler No. 1; the NOX

BART determination for the natural gas 

firing scenario and the SO2, NOX, and 

PM BART determinations for the fuel oil 

firing scenario for the Entergy Lake 

Catherine Plant Unit 4; the SO2 and 

NOX BART determinations for both the 

bituminous and sub-bituminous coal 

firing scenarios for the Entergy White 

Bluff Plant Units 1 and 2; the BART 

determination for the Entergy White 

Bluff Plant Auxiliary Boiler; the SO2

and NOX BART determinations for the 

Domtar Ashdown Mill Power Boiler No. 

1; and the SO2, NOX and PM BART 

determinations for the Domtar Ashdown 

Mill Power Boiler No. 2. In reviewing 

the State’s BART determinations for 

these pollutants and units, we found 

that the State did not satisfy all the 

regulatory and statutory requirements in 

making these BART determinations. We 

have therefore determined it is 

appropriate to finalize our proposed 

disapproval of the State’s BART 

determinations for these units, because 

we conclude that the flaws and 

omissions in the State’s BART analyses 

were significant, and that the State 

therefore lacked adequate record 

support and a reasoned basis for its 

analyses, as required by the RH Rule 

(RHR). As we previously noted, 

Arkansas submitted Chapter 15 of 

APCEC Regulation No. 19, also known 

as the State’s RH Rule, as a SIP revision 

to address both RH and the visibility 

transport requirements. With respect to 

RH, we are partially approving and 

partially disapproving Chapter 15 of 

APCEC Regulation No. 19, such that our 

disapproval is of those portions of the 

State’s RH Rule that correspond to 

portions of the Arkansas RH SIP we are 

disapproving. In particular, we note that 

based upon public comment, we also 

are disapproving the portion of the 

BART compliance provision found in 

Chapter 15 of APCEC Regulation No. 19, 

at Reg. 19.1504(B), which requires each 

source subject to BART to install and 

operate BART requirements no later 

than six years after the effective date of 

the State’s regulation. We are approving 

the portion of the BART compliance 

provision that requires each Arkansas 

subject to BART source to install and 

operate BART as expeditiously as 

practicable, but in no event later than 

five years after EPA approval of the 

Arkansas RH SIP, for those sources’ 

BART determinations we are approving. 

We find that this is consistent with the 

requirements under 40 CFR 

51.308(e)(iv). Arkansas’s inclusion of 

the compliance provision that would 

require Arkansas subject to BART 

sources to install and operate BART no 

later than six years after the effective 

date of the State’s regulation (if such 

date takes place before five years from 

EPA approval of the Arkansas RH SIP) 

is not a required element of the RH SIPs 

to be developed and submitted by states 

pursuant to section 169 of the CAA. We 

are also partially approving and 

partially disapproving the State’s 

submitted LTS because it relies on 

portions of the RH SIP we are 

disapproving, including some of 

Arkansas’s BART emission limits. We 

are disapproving the State’s RPGs under 

40 CFR 51.308(d)(1) because Arkansas 

did not consider the four factors that 

states are required to consider in 

establishing RPGs under the CAA and 

40 CFR 51.308(d)(1)(A). 

We are approving the remaining 

sections of the RH SIP submission. This 

includes certain core elements of the 

SIP, including Arkansas’s (1) 

Identification of affected Class I areas; 

(2) determination of baseline and 

natural visibility conditions; (3) 

determination of the URP; (4) RPG 

consultation and LTS consultation; (5) 

coordination of regional haze and 

reasonably attributable visibility 

impairment; (6) monitoring strategy and 

other implementation requirements; (7) 

commitment to submit periodic RH SIP 

revisions and periodic progress reports 

describing progress towards the RPGs; 

(8) commitment to make a 

determination of the adequacy of the 

existing SIP at the time a progress report 

is submitted; (9) coordination with 

states and FLMs; and (10) the following 

BART determinations from Arkansas’s 

RH SIP: 

• The PM BART determination for 

the AEP Flint Creek Plant Boiler No. 1. 

• The SO2 and PM BART 

determinations for the natural gas firing 

scenario for the Entergy Lake Catherine 

Plant Unit 4. 

• The PM BART determinations for 

both the bituminous and subbituminous coal firing scenarios for the 

Entergy White Bluff Plant Units 1 

and 2. 

• The PM BART determination for 

the Domtar Ashdown Mill Power Boiler 

No. 1. 

Arkansas stated in its April 2, 2008 

submittal that it is relying on Chapter 15 

of APCEC Regulation No. 19, also 

known as the State’s RH Rule, to satisfy 

the requirements of section 

110(a)(2)(D)(i)(II) that emissions from 

Arkansas sources not interfere with 

measures required in the SIP of any 

other state under part C of the CAA to 

protect visibility. The Arkansas 

Department of Environmental Quality 

(ADEQ) also stated in its April 2, 2008, 

submittal that it is not possible to assess 

whether there is any interference with 

the measures in the applicable SIP for 

another state designed to protect 

visibility for the 8-hour ozone and PM2.5

NAAQS until ADEQ submits and EPA 

approves Arkansas’s RH SIP. We 

proposed to partially approve and 

partially disapprove this submission as 

it relied upon the State’s RH Rule that 

we were proposing to partially approve 

and partially disapprove. In developing 

their RH SIP and RPGs, Arkansas and 

potentially impacted States collaborated 

through the Central Regional Air 

Planning (CENRAP) association. Each 

state developed its RH Plans and RPGs 

based on the CENRAP modeling. The 

CENRAP modeling was based in part on 

the emissions reductions each state 

intended to achieve by 2018. Some of 

the emissions reductions included in 

the CENRAP’s modeling and thus relied 

upon by other states, were from BART 

controls on Arkansas subject to BART 

sources. Compliance with these BART 

requirements will ensure that Arkansas 

obtains its share of the emission 

reductions relied upon by other states to 

meet the RPGs for their Class I areas. As 

already previously discussed in this 

final rulemaking, Arkansas submitted 

Chapter 15 of APCEC Regulation No. 19, 

also known as the State’s RH Rule, as a 

SIP revision to address both RH and the 

visibility transport requirements. With 

respect to the visibility interstate 

transport SIP, we are partially approving 

and partially disapproving the 

submitted Chapter 15 of APCEC 

Regulation No. 19, such that our 

disapproval is of those portions that 

correspond to the submitted BART 

determinations we are disapproving. In 

response to public comment, we note 

that we also are disapproving the 

portion of the BART compliance 


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2CAA section 110(c)(1). 3 76 FR 64186. 

provision found in the APCEC 

Regulation No. 19, at Reg. 19.1504(B), 

which requires each source subject to 

BART to install and operate BART no 

later than six years after the effective 

date of the State’s regulation. Since 

compliance of Arkansas’s subject to 

BART sources with BART requirements 

now is solely dependent upon our 

approval of the RH SIP, and since we 

are disapproving the portion of the RH 

SIP which includes some of Arkansas’s 

BART determinations, a portion of the 

emission reductions committed to by 

Arkansas and relied upon by other 

states will not be realized. 

Consequently, Arkansas’s emissions 

will interfere with other states’ SIPs to 

protect visibility. Therefore, we are 

partially approving and partially 

disapproving the portion of the 

Arkansas Interstate Transport SIP 

submittal that addresses the visibility 

requirement of section 110(a)(2)(D)(i)(II) 

that emissions from Arkansas sources 

not interfere with measures required in 

the SIP of any other state under part C 

of the CAA to protect visibility. 

Under the CAA,2 we must, within 24 

months following a final disapproval, 

either approve a SIP or promulgate a 

Federal Implementation Plan (FIP). We 

will of course consider, and would 

prefer, approving a SIP if the state 

submits a revised plan that we can 

approve before the expiration of the 

mandatory FIP clock for the portions of 

the SIP we are disapproving in this 

rulemaking action. 

We originally provided a 30 day 

public comment period for this action, 

which we extended after receiving 

several requests for an extension on the 

comment period. We held a 66 day 

public comment period for this action. 

Many public commenters disagreed 

with several aspects of our proposal, 

expressing the belief that we should 

approve either more portions of the 

Arkansas RH SIP or the SIP in its 

entirety. We also received public 

comments agreeing with several aspects 

of our proposal, expressing the belief 

that we should disapprove either more 

portions of the Arkansas RH SIP or the 

SIP in its entirety. All public comments 

and our responses are discussed in more 

detail in section III of this final 

rulemaking action. 

This action is being taken under 

section 110 and part C of the CAA. 

Table of Contents 

I. Summary of Our Proposal 

A. Regional Haze 

B. Interstate Transport of Pollutants and 

Visibility Protection 

II. Final Decision 

A. Regional Haze 

B. Interstate Transport of Pollutants and 

Visibility Protection 

III. Public Comments Received and Our 

Responses 

A. Comments on Presumptive Emission 

Limits 

B. Comments on Reasonable Progress Goals 

and Long Term Strategy 

C. Comments on BART 

1. Evaluation of the Most Stringent Level 

of Control in the BART Analysis 

2. Evaluation of Post-Combustion Controls 

in the BART Analysis 

3. Comments on the State’s PM BART 

Emission Limits We Proposed to 

Approve 

4. Comments on the Capacity Factor Used 

in the State’s BART Analyses for Entergy 

Lake Catherine and White Bluff 

5. Comments on the State’s Cost 

Evaluations 

6. Comments on the August 2008 Revised 

BART Analysis for White Bluff 

7. Other Comments Related to BART 

D. Comments on the Arkansas Pollution 

Control and Ecology Commission 

Variance for Subject to BART Sources 

E. Comments on BART and the 

Forthcoming MACT Requirements 

F. Comments on Modeling 

G. Comments on Legal Issues 

1. Comments on Regional Haze 

2. Comments on Interstate Transport and 

Visibility 

H. Other Comments 

I. Comments Requesting an Extension to 

the Public Comment Period 

IV. Statutory and Executive Order Reviews 

I. Summary of Our Proposal 

On October 17, 2011, we published 

the proposal on which we are now 

taking final action.3 We proposed to 

partially approve and partially 

disapprove Arkansas’s RH SIP revision 

submitted on September 23, 2008, 

August 3, 2010, and supplemented on 

September 27, 2011. We also proposed 

to partially approve and partially 

disapprove a portion of a SIP revision 

we received from the State of Arkansas 

on April 2, 2008, as supplemented on 

September 27, 2011, for the purpose of 

addressing the ‘‘good neighbor’’ 

provisions of the CAA section 

110(a)(2)(D)(i)(II) with respect to 

visibility for the 1997 8-hour ozone 

NAAQS and the PM2.5 NAAQS. 

A. Regional Haze 

We proposed to approve the State’s 

identification of BART-eligible sources, 

with the exception of the 6A Boiler at 

the Georgia-Pacific Crossett Mill, which 

we find to be BART-eligible. We 

proposed to approve the State’s 

identification of subject to BART 

sources, with the exception of the 6A 

and 9A Boilers at the Georgia-Pacific 

Crossett Mill, which we find to be 

subject to BART. We also proposed to 

approve certain core elements of the 

SIP, including Arkansas’s (1) 

identification of affected Class I areas; 

(2) determination of baseline and 

natural visibility conditions; (3) 

determination of the URP; (4) RPG 

consultation and LTS consultation; (5) 

coordination of regional haze and 

reasonably attributable visibility 

impairment; (6) monitoring strategy and 

other implementation requirements; (7) 

commitment to submit periodic RH SIP 

revisions and periodic progress reports 

describing progress towards the RPGs; 

(8) commitment to make a 

determination of the adequacy of the 

existing SIP at the time a progress report 

is submitted; (9) coordination with 

states and FLMs; and (10) the following 

BART determinations from Arkansas’s 

RH SIP: the PM BART determination for 

the AEP Flint Creek Plant Boiler No. 1; 

the SO2 and PM BART determinations 

for the natural gas firing scenario for the 

Entergy Lake Catherine Plant Unit 4; the 

PM BART determinations for both the 

bituminous and sub-bituminous coal 

firing scenarios for the Entergy White 

Bluff Plant Units 1 and 2; and PM BART 

determination for the Domtar Ashdown 

Mill Power Boiler No. 1. 

We proposed to disapprove 

Arkansas’s SO2, NOX, and PM BART 

determinations for the AECC Bailey 

Plant Unit 1 and the AECC McClellan 

Plant Unit 1; the SO2 and NOX BART 

determinations for the AEP Flint Creek 

Plant Boiler No. 1; the NOX BART 

determination for the natural gas firing 

scenario and the SO2, NOX, and PM 

BART determinations for the fuel oil 

firing scenario for the Entergy Lake 

Catherine Plant Unit 4; the SO2 and 

NOX BART determinations for both the 

bituminous and sub-bituminous coal 

firing scenarios for the Entergy White 

Bluff Plant Units 1 and 2; the BART 

determination for the Entergy White 

Bluff Plant Auxiliary Boiler; the SO2

and NOX BART determinations for the 

Domtar Ashdown Mill Power Boiler No. 

1; and the SO2, NOX and PM BART 

determinations for the Domtar Ashdown 

Mill Power Boiler No. 2 because they do 

not comply with our regulations under 

40 CFR 51.308(e). We also proposed to 

partially approve and partially 

disapprove the Arkansas RH Rule, 

Chapter 15 of APCEC Regulation No. 19, 

such that our proposed disapproval was 

of those portions of the State’s RH Rule 

that correspond to portions of the 

Arkansas RH SIP we were proposing to 

disapprove. We also proposed to 

partially approve and partially 

disapprove the LTS under 40 CFR 


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51.308(d)(3) because Arkansas has not 

shown that the strategy is adequate to 

achieve the RPGs set by Arkansas and 

by other nearby states. 

We proposed to disapprove the State’s 

RPGs under 40 CFR 51.308(d)(1) 

because Arkansas did not consider the 

four factors states are required to 

consider in establishing RPGs under the 

CAA and 40 CFR 51.308(d)(1)(A). 

B. Interstate Transport of Pollutants and 

Visibility Protection 

We proposed to partially approve and 

partially disapprove a portion of a SIP 

revision we received from the State of 

Arkansas on April 2, 2008, as 

supplemented on September 27, 2011, 

for the purpose of addressing the ‘‘good 

neighbor’’ provisions of the CAA section 

110(a)(2)(D)(i) with respect to visibility 

for the 1997 8-hour ozone NAAQS and 

the PM2.5 NAAQS. This SIP revision 

addressed the requirement of section 

110(a)(2)(D)(i)(II) that emissions from 

Arkansas sources do not interfere with 

measures required in the SIP of any 

other state under part C of the CAA to 

protect visibility. ADEQ participated in 

the CENRAP visibility modeling 

development that assumed certain SO2, 

NOX, and PM reductions from 

Arkansas’s BART sources. Compliance 

with these BART requirements will 

ensure that Arkansas obtains its share of 

the emission reductions relied upon by 

other states to meet the RPGs for their 

Class I areas. Since compliance of 

Arkansas’s subject to BART sources 

with BART requirements is dependent 

upon our approval of the RH SIP, and 

since we proposed to disapprove the 

portion of the RH SIP which includes 

some of Arkansas’s BART 

determinations, a portion of the 

emission reductions committed to by 

Arkansas and relied upon by other 

states will not be realized and, as a 

consequence, Arkansas’s emissions will 

interfere with other states’ SIPs to 

protect visibility. 

II. Final Decision 

A. Regional Haze 

With one exception, we are finalizing 

our action as proposed. As discussed 

below, based upon public comment, we 

are adjusting our action on the Arkansas 

RH Rule. We are partially approving and 

partially disapproving the Arkansas RH 

SIP revision submitted on September 

23, 2008, August 3, 2010, and 

supplemented on September 27, 2011. 

We are approving Arkansas’s 

identification of sources that are BART 

eligible, with the exception of the 6A 

Boiler at the Georgia-Pacific Crossett 

Mill, which we find to be BARTeligible. We are also approving 

Arkansas’s identification of subject to 

BART sources, with the exception of the 

6A and 9A Boilers at the Georgia-Pacific 

Crossett Mill, which we find to be 

subject to BART. 

We are disapproving Arkansas’s SO2, 

NOX, and PM BART determinations for 

the AECC Bailey Plant Unit 1 and the 

AECC McClellan Plant Unit 1; the SO2

and NOX BART determinations for the 

AEP Flint Creek Plant Boiler No. 1; the 

NOX BART determination for the 

natural gas firing scenario and the SO2, 

NOX, and PM BART determinations for 

the fuel oil firing scenario for the 

Entergy Lake Catherine Plant Unit 4; the 

SO2 and NOX BART determinations for 

both the bituminous and subbituminous coal firing scenarios for the 

Entergy White Bluff Plant Units 1 and 

2; the BART determination for the 

Entergy White Bluff Plant Auxiliary 

Boiler; the SO2 and NOX BART 

determinations for the Domtar Ashdown 

Mill Power Boiler No. 1; and the SO2, 

NOX and PM BART determinations for 

the Domtar Ashdown Mill Power Boiler 

No. 2. With respect to RH, we are 

partially approving and partially 

disapproving the Arkansas RH Rule, 

Chapter 15 of APCEC Regulation No. 19, 

such that our disapproval is of those 

portions of the State’s RH Rule that 

correspond to portions of the Arkansas 

RH SIP we are disapproving and our 

approval is of the remaining portions. 

We do note that in response to 

comments received, we are making one 

change to the portions of the Arkansas 

RH Rule we are approving from what we 

proposed to approve in our October 17, 

2011, proposed rulemaking. 

Specifically, in our proposed 

rulemaking, we proposed to approve 

Reg. 19.1504(B), which requires 

Arkansas’s subject to BART sources to 

‘‘install and operate BART as 

expeditiously as practicable, but in no 

event later than 6 years after the 

effective date of [the State RH Rule] or 

5 years after EPA approval of the 

Arkansas Regional Haze State 

Implementation Plan, whichever comes 

first.’’ As discussed in more detail in 

our response to comments, because the 

State revised its rule to delete the 

provision that would require Arkansas’s 

subject to BART sources to comply with 

BART within 6 years of the effective 

date of the State RH Rule, we are 

disapproving this portion of the BART 

compliance provision found in Chapter 

15 of APCEC Regulation No. 19. We are 

partially approving and partially 

disapproving the portion of the BART 

compliance provision that requires each 

Arkansas subject to BART source to 

install and operate BART as 

expeditiously as practicable, but in no 

event later than five years after EPA 

approval of the Arkansas RH SIP. The 

disapproval is of those portions of the 

State’s RH Rule that correspond to 

portions of the Arkansas RH SIP we are 

disapproving. We find that this is 

consistent with the requirements under 

40 CFR 51.308(e)(iv). We are partially 

approving and partially disapproving 

the LTS under 40 CFR 51.308(d)(3). We 

are disapproving the State’s RPGs under 

40 CFR 51.308(d)(1). 

We are approving the remaining 

sections of the RH SIP submission. This 

includes certain core elements of the 

SIP, including Arkansas’s (1) 

identification of affected Class I areas; 

(2) determination of baseline and 

natural visibility conditions; (3) 

determination of the URP; (4) RPG 

consultation and LTS consultation; (5) 

coordination of regional haze and 

reasonably attributable visibility 

impairment; (6) monitoring strategy and 

other implementation requirements; (7) 

commitment to submit periodic RH SIP 

revisions and periodic progress reports 

describing progress towards the RPGs; 

(8) commitment to make a 

determination of the adequacy of the 

existing SIP at the time a progress report 

is submitted; (9) coordination with 

states and FLMs; and (10) the following 

BART determinations from Arkansas’s 

RH SIP: 

• The PM BART determination for 

the AEP Flint Creek Plant Boiler No. 1. 

• The SO2 and PM BART 

determinations for the natural gas firing 

scenario for the Entergy Lake Catherine 

Plant Unit 4. 

• The PM BART determinations for 

both the bituminous and subbituminous coal firing scenarios for the 

Entergy White Bluff Plant Units 1 and 

2. 

• The PM BART determination for 

the Domtar Ashdown Mill Power Boiler 

No. 1. 

B. Interstate Transport of Pollutants and 

Visibility Protection 

We are partially approving and 

partially disapproving a portion of a SIP 

revision we received from the State of 

Arkansas on April 2, 2008, as 

supplemented on September 27, 2011, 

for the purpose of addressing the ‘‘good 

neighbor’’ provisions of the CAA section 

110(a)(2)(D)(i) with respect to visibility 

for the 1997 8-hour ozone NAAQS and 

the PM2.5 NAAQS. Because Arkansas 

relied on Chapter 15 of APCEC 

Regulation No. 19, to satisfy the 

requirements of section 

110(a)(2)(D)(i)(II) that emissions from 

Arkansas sources not interfere with 


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14608 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

4 69 FR 39129 and CAA section 169(a)(4). 

5 42 U.S.C. 7491(b). 

6 40 CFR 51.308(e)(1)(ii)(B) and Appendix Y to 

Part 51. 

measures required in the SIP of any 

other state under part C of the CAA to 

protect visibility, we are partially 

approving and partially disapproving 

the submitted Chapter 15 of APCEC 

Regulation No. 19, such that our 

disapproval is of those portions that 

correspond to the submitted BART 

determinations we are disapproving. In 

response to public comment, we note 

that we also are disapproving the 

portion of the BART compliance 

provision found in the APCEC 

Regulation No. 19, at Reg. 19.1504(B), 

which requires each source subject to 

BART to install and operate BART no 

later than six years after the effective 

date of the State’s regulation. Since 

compliance of Arkansas’s subject to 

BART sources with BART requirements 

now is solely dependent upon our 

approval of the RH SIP, and since we 

are disapproving the portion of the RH 

SIP which includes some of Arkansas’s 

BART determinations, a portion of the 

emission reductions committed to by 

Arkansas and relied upon by other 

states will not be realized and, as a 

consequence, Arkansas’s emissions will 

interfere with other states’ SIPs to 

protect visibility. Therefore, we are 

partially approving and partially 

disapproving the portion of the 

Arkansas Interstate Transport SIP 

submittal that addresses the visibility 

requirement of section 110(a)(2)(D)(i)(II) 

that emissions from Arkansas sources 

not interfere with measures required in 

the SIP of any other state under part C 

of the CAA to protect visibility. 

III. Public Comments Received and Our 

Responses 

During the public notice and 

comment period, we received 13 

comment letters both supporting and 

opposing our proposal. We received 

comments from the ADEQ, the Utah 

Department of Environmental Quality 

(UDEQ), the National Park Service, the 

Sierra Club, Entergy Arkansas Inc., the 

American Electric Power/Southwestern 

Electric Power Company (AEP– 

SWEPCO), the Arkansas Electric 

Cooperative Corporation, Domtar 

Industries Inc., Nucor Steel-Arkansas, 

the Competitive Enterprise Institute, the 

Utility Air Regulatory Group, PacifiCorp 

Energy, and the Energy and 

Environmental Alliance of Arkansas. 

The comments we received opposing 

our proposal contended that we had 

either overstepped our bounds in 

proposing a partial disapproval or that 

we had not gone far enough in our 

action and should fully disapprove 

Arkansas’s RH SIP. Many of the 

comments received are similar in nature 

and are grouped together accordingly. 

Thus, many of the comments you will 

read are representative of more than one 

comment letter. The comments are 

summarized and addressed below. The 

full text received from these 

commenters is included in the docket 

associated with this action. 

A. Comments on Presumptive Emission 

Limits 

Comment: The SO2 and NOX BART 

determinations for the AEP Flint Creek 

Boiler No. 1 and Entergy White Bluff 

Plant Units 1 and 2 meet the 

presumptive BART limits established in 

40 CFR part 51, appendix Y (BART 

Guidelines). In the Arkansas RH 

proposal, EPA did not justify its 

decision that the presumptive BART 

limits are unacceptable. EPA is insisting 

on a five factor analysis even when a 

source can meet the presumptive limits. 

EPA’s current interpretation of the 

presumptive BART limits makes the 

presumptive BART limits meaningless, 

contrary to the requirements of the CAA 

and the clear intent of the BART Rule. 

The CAA singles out electric generating 

units (EGUs) located at 750 megawatt 

(MW) power plants for specific BART 

controls (42 U.S.C. 7491(b)(2)), and EPA 

adopted the presumptive BART limits to 

establish the specific control levels 

required for these EGUs. Since EPA 

went through extensive analysis to 

establish presumptive BART limits, the 

only rational explanation is that EPA 

intended for those limits to be 

meaningful. EPA is rationalizing its 

decision on the Arkansas RH SIP as if 

the presumptive BART limits were no 

longer a binding regulation, and there is 

concern that EPA is attempting to 

establish new, more stringent 

presumptive BART limits through caseby-case disapprovals of state BART 

determinations. Unless and until EPA 

goes through notice and comment 

rulemaking to remove the presumptive 

emission limits and establish other 

requirements consistent with the CAA, 

the presumptive BART limits in the 

promulgated BART Rule continue to 

establish the requirement that states 

must meet in their regional haze SIPs for 

large coal-fired EGUs and EPA must 

approve a state’s BART determination if 

it meets the presumptive regulatory 

limits. 

Response: Our application of the 

presumptive BART limits in our 

proposed rulemaking on the Arkansas 

RH SIP gives proper treatment of 

presumptive BART limits and is 

consistent with the requirements of the 

CAA and the intent of the BART Rule. 

We note that the states generally have 

broad authority to decide appropriate 

BART controls. However, the CAA gives 

EPA a more active role in establishing 

BART emission limits for large power 

plants.4 The CAA states the following 

regarding emission limits for fossil-fuel 

fired generating power plants having a 

total generating capacity in excess of 

750 MW: 

‘‘In the case of a fossil-fuel fired 

generating power plant having a total 

generating capacity in excess of 750 

megawatts, the emissions limitations 

required under this paragraph shall be 

determined pursuant to guidelines, 

promulgated by the Administrator 

under paragraph (1).’’ 5

EPA disagrees that the CAA mandates 

specific control levels (i.e. presumptive 

emission limits) for power plants with 

a total generating capacity of 750 MW or 

greater. Rather, the CAA directed EPA to 

develop guidelines for States to 

establish BART emission limits, and 

required that power plants having a 

total generating capacity in excess of 

750 MW follow the guidelines when 

establishing BART emission limits. In 

response, in 2005 EPA promulgated the 

BART Guidelines, which provide a 

detailed description of how a State must 

approach the BART determination 

process for certain large EGUs, and 

required that the determination of fossilfuel fired power plants having a total 

generating capacity greater than 750 

MW must be made pursuant to the 

BART Guidelines.6 As such, the plain 

reading of the CAA language makes it 

clear the intent was to make the BART 

Guidelines mandatory for EGUs larger 

than 750 MW, as opposed to 

presumptive limits. Therefore, EPA’s 

proposed rulemaking on the Arkansas 

RH SIP is not contrary to the 

requirements of the CAA. 

The EPA went through extensive 

analysis to establish presumptive BART 

emission limits, and intended these 

limits to be meaningful. As stated in our 

proposed rulemaking on the Arkansas 

RH SIP, the purpose of the presumptive 

limits in the BART Guidelines was to 

identify controls that the Agency 

considered to be generally cost-effective 

across all affected units. Because EPA’s 

extensive analysis found that these 

controls are generally cost-effective 

across all affected units and were 

anticipated to result in a substantial 

degree of visibility improvement, EPA 

concluded that such units should at 

least meet the presumptive limits. 

However, EPA’s BART Rule does not 

state that the presumptive limits will 

represent the ‘‘best available retrofit 


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7 70 FR 39131. 

8 70 FR 39132. 

9 71 FR 60619. 

10 70 FR 39158. 

11 71 FR 60619. 

12 70 FR 39171. 

13Appendix Y to Part 51, section IV.E.5. 

14 70 FR 39132. 

controls’’ for all EGUs at these larger 

power plants. Instead, EPA’s BART Rule 

and the BART Guidelines make clear 

that in developing the presumptive 

emission limits, EPA made many design 

and technological assumptions, and that 

the presumptive limits may not be 

BART in every case. As such, the 

presumption in the BART Rule is not 

that the presumptive limits will be 

BART in every case. Rather, the 

presumption in the BART Rule is more 

accurately interpreted to be that the 

controls reflected by the presumptive 

limits are cost-effective and will result 

in considerable visibility improvement. 

EPA’s intent was for these generally 

cost-effective controls to be used in the 

State’s BART analysis considering the 

five factors specified in CAA section 

169A(g)(2), and considering the level of 

control that is currently achievable at 

the time that the BART analysis is being 

conducted. 

We note the RHR states: 

‘‘States, as a general matter, must require 

owners and operators of greater than 750 MW 

power plants to meet these BART emission 

limits. We are establishing these 

requirements based on the consideration of 

certain factors discussed below. Although we 

believe that these requirements are extremely 

likely to be appropriate for all greater than 

750 MW power plants subject to BART, a 

State may establish different requirements if 

the State can demonstrate that an alternative 

determination is justified based on a 

consideration of the five statutory factors.’’ 7

The RHR also states: 

‘‘If, upon examination of an individual 

EGU, a State determines that a different 

emission limit is appropriate based upon its 

analysis of the five factors, then the State 

may apply a more or less stringent limit.’’ 8

Therefore, the presumptive emission 

limits in the BART Guidelines are 

rebuttable.9 The presumptive emission 

limits apply to power plants with a total 

generating capacity of 750 MW or 

greater insofar as these sources are 

required to adopt emission limits at 

least as stringent as the presumptive 

limits, unless after considering the five 

statutory factors, the State determines 

that the presumptive emission limits are 

not appropriate. Moreover, the RHR and 

BART Guidelines do not exempt states 

from a five factor BART analysis, and 

that BART analysis may result in a 

determination of BART emission limits 

that are more or less stringent than the 

presumptive emission limits for subject 

to BART sources. The RHR states: 

‘‘For each source subject to BART, 40 CFR 

51.308(e)(1)(ii)(A) requires that States 

identify the level of control representing 

BART after considering the factors set out in 

CAA section 169A(g), as follows: 

States must identify the best system of 

continuous emission control technology for 

each source subject to BART taking into 

account the technology available, the costs of 

compliance, the energy and non-air quality 

environmental impacts of compliance, any 

pollution control equipment in use at the 

source, the remaining useful life of the 

source, and the degree of visibility 

improvement that may be expected from 

available control technology.’’ 10

As previously stated, the presumptive 

emission limits apply to power plants 

with a total generating capacity of 750 

MW or greater insofar as these sources 

are required to adopt emission limits at 

least as stringent as the presumptive 

limits, unless after considering the five 

statutory factors, the State determines 

that a more or less stringent emission 

limit is appropriate. Further, EPA is not 

attempting to establish new, more 

stringent presumptive BART limits. As 

a matter of fact, EPA’s proposed 

rulemaking did not propose to establish 

particular BART emission limits on any 

of Arkansas’s subject to BART sources. 

Instead, EPA’s proposed rulemaking 

proposed to disapprove the State’s 

BART limits where the State adopted 

the NOX and SO2 presumptive emission 

limits without conducting a proper five 

factor BART analysis, as required by the 

RHR and the CAA, to determine if an 

emission limit more or less stringent 

than the presumptive limits is BART. 

EPA disagrees that our approach is 

not consistent with the RHR and that we 

must undergo notice and comment 

rulemaking to follow our application of 

the presumptive BART limits for large 

coal-fired EGUs. EPA reiterates that the 

RHR and the BART Guidelines make 

clear that the presumptive limits are 

rebuttable and may not necessarily be 

the appropriate level of control for all 

EGUs.11 Therefore, EPA is not required 

to approve every BART determination 

that meets the presumptive emission 

limits, especially when there is no 

analysis that supports the state’s 

decision in adopting the presumptive 

limit instead of a more or less stringent 

emission limit. 

Comment: The BART Rule shows that 

an alternative analysis is required only 

when a source cannot meet the 

presumptive limits (40 CFR part 51, 

appendix Y, section IV.E.5). As such, 

only when EGUs cannot meet 

presumptive NOX limits using current 

combustion control technology should 

other technologies be considered. The 

plain reading of the BART Rule is 

contrary to EPA’s proposal to 

disapprove the NOX presumptive 

emission limits adopted for BART by 

Arkansas. 

Response: Regarding NOX

presumptive emission limits, the BART 

Rule provides that: 

‘‘For coal-fired EGUs greater than 200 

MW located at greater than 750 MW 

power plants and operating without 

post-combustion controls (i.e. Selective 

Catalytic Reduction or Selective NonCatalytic Reduction), we have provided 

presumptive NOX limits, differentiated 

by boiler design and type of coal 

burned. You may determine that an 

alternative control level is appropriate 

based on a careful consideration of the 

statutory factors. For coal-fired EGUs 

greater than 200 MW located at power 

plants 750 MW or less in size and 

operating without post-combustion 

controls, you should likewise presume 

that these same levels are cost-effective, 

unless you determine that an alternative 

control level is justified based on 

consideration of the statutory 

factors.’’ 12

The BART Rule does not contain 

language stating that an alternative 

analysis is required only when a source 

cannot meet the presumptive limits. The 

BART Guidelines provides the 

following: 

‘‘Most EGUs can meet these 

presumptive NOX limits through the use 

of current combustion control 

technology, i.e. the careful control of 

combustion air and low-NOX burners. 

For units that cannot meet these limits 

using such technologies, you should 

consider whether advanced combustion 

control technologies such as rotating 

opposed fire air should be used to meet 

these limits.’’ 13

The intent of this language is to 

communicate that EPA believes that the 

large majority of units can at least meet 

the presumptive limits at relatively low 

costs (i.e. without post-combustion 

controls). Because of this, EPA found it 

appropriate to require EGUs greater than 

200 MW located at greater than 750 MW 

power plants and without postcombustion controls to at least meet the 

presumptive limit, unless based on an 

evaluation of the statutory factors the 

State found a more or less stringent 

emission limit is appropriate.14 The 

language in the BART Guidelines 

should not be misinterpreted to mean 

that sources capable of meeting the 

presumptive limits may forego a BART 

analysis or that they need not consider 

post-combustion controls if they can 


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15See 40 CFR 51.308(e)(1)(ii)(A) and 42 U.S.C. 

7491(g)(2). 

16 70 FR 39171. 17 42 U.S.C. 7491(g)(2). 18 42 U.S.C. 7491(g)(2). 

meet the NOX presumptive limits with 

combustion controls. States have a duty 

to evaluate the five statutory factors,15

and should consider the level of control 

that is currently achievable at the time 

the BART analysis is conducted.16

Comment: The preamble discussion of 

the BART Rule shows that the 

presumptive BART limits were intended 

to establish a presumptively acceptable 

BART determination for large EGUs. 

The preamble to the proposed May 5, 

2004, and final July 5, 2005, BART Rule 

demonstrate the clear intent that the 

presumptive limits in the BART Rule 

are BART. In its proposed disapproval 

of the Arkansas RH SIP, EPA ignores 

this. Nothing in the BART Rule or the 

preamble to the rule requires that a 

source achieve a more stringent 

emission rate if the emission controls 

allow the source to meet the 

presumptive emission limits. Section 

169A(g) of the CAA requires a balancing 

of the five statutory factors when a State 

is determining BART. The preamble to 

the BART Rule describes the 

presumptive limits as reasonable, costeffective, extremely likely to be 

appropriate and likely to result in a 

significant degree of visibility 

improvement. The term ‘‘presumptive 

minimum’’ or a discussion of controls 

more stringent than the presumptive 

limits is not found in the BART Rule. 

Response: The EPA disagrees that the 

presumptive BART limits in the BART 

Rule were intended to establish BART 

in every case, as nothing on the record 

states that the presumptive limits 

represent the ‘‘best available retrofit 

controls’’ for all EGUs at these large 

power plants. On the contrary, EPA’s 

BART Rule and the BART Guidelines 

make clear that in developing the 

presumptive emission limits, EPA made 

many design and technological 

assumptions, and that the presumptive 

limits may not be BART in every case. 

As such, the presumption in the BART 

Rule is not that the presumptive limits 

will be BART in every case. Rather, the 

presumption in the BART Rule is more 

accurately interpreted to be that the 

controls reflected by the presumptive 

limits are cost-effective and will result 

in considerable visibility improvement. 

EPA’s proposed rulemaking on the 

Arkansas RH SIP did not propose to 

require Arkansas’s subject to BART 

sources to achieve an emission rate 

more stringent than the presumptive 

emission limits. Rather, EPA’s proposed 

rulemaking proposed to disapprove the 

BART emission limits for subject to 

BART sources where the State adopted 

presumptive emission limits without 

conducting a proper BART five factor 

analysis. Only after the State conducts 

a proper evaluation of the five statutory 

factors, as required by 40 CFR 

51.308(e)(1)(ii)(A) and section 169A(g) 

of the CAA, or EPA conducts one in the 

context of a FIP, will it be demonstrated 

whether any of Arkansas’s subject to 

BART sources must achieve an emission 

rate more (or less) stringent than the 

presumptive limits. 

EPA agrees that section 169A(g) of the 

CAA requires a balancing of the five 

statutory factors when a State is 

determining BART.17 EPA is also in 

agreement that the preamble to the 

BART Rule describes the presumptive 

limits as reasonable, cost-effective, 

extremely likely to be appropriate and 

likely to result in a significant degree of 

visibility improvement. However, EPA 

reiterates that the BART Rule does not 

state that the presumptive limits will 

represent the ‘‘best available retrofit 

controls’’ for all EGUs at these larger 

power plants. EPA agrees that the term 

‘‘presumptive minimum’’ or a 

discussion of controls more stringent 

than the presumptive limits are not 

explicitly found in the BART Rule, but 

the BART Rule does require that 

affected sources achieve at least the 

level of control represented by the 

presumptive limits, unless a proper 

evaluation of the five statutory factors 

demonstrates that a different level of 

control is BART for the affected sources. 

Comment: The CAA gives states 

discretion to make BART 

determinations, and while a state may 

choose to establish a limit that is more 

stringent than the presumptive limit, 

there is nothing in the BART Rule that 

would require a state to do so. There are 

a number of examples in the BART 

regulations and in the preambles to the 

proposed and final BART Rule, showing 

that a state has discretion to choose to 

demonstrate an alternative control level. 

The preamble to the BART Rule 

recognizes that in some limited cases, 

where the source cannot meet the 

presumptive limit, a state could 

demonstrate an alternative level of 

control. The plain meaning of the BART 

Rule and the preamble discussion of the 

presumptive limits supports a reading of 

the BART Rule that discretion rests with 

a state, not EPA, as to whether the 

presumptive limits are reasonable. 

Response: The EPA agrees with the 

comment that the CAA gives states 

discretion to make BART 

determinations, and that there are 

examples in the BART regulations and 

in the preambles to the proposed and 

final BART Rule showing that a state 

has discretion to choose an alternative 

control level after considering the five 

statutory factors. However, section 

169A(g) of the CAA requires States to 

consider these statutory factors in 

determining BART for affected 

sources.18 If a proper evaluation of the 

five statutory factors demonstrates that 

an emission limit more or less stringent 

than the presumptive limit is BART for 

the subject to BART source in question, 

then the State must require the source 

to comply with such emission limit. 

EPA agrees that states have considerable 

discretion in making BART 

determinations, but if the State has not 

conducted a proper evaluation of the 

five statutory factors, as required by 40 

CFR 51.308(e)(1)(ii)(A) and section 

169A(g) of the CAA, the State cannot 

determine that the presumptive limits 

are the ‘‘best available retrofit controls’’ 

for Arkansas’s affected sources. 

Comment: The EPA proposes to reject 

Arkansas’s BART determinations that 

rely on the presumptive BART limits 

codified in EPA’s own BART 

Guidelines, arguing that states are 

required to perform a case-by-case 

BART analysis in every instance and 

that they can never rely on the 

presumptive limits (76 FR 64201). The 

BART rules state that the presumptive 

limits should be adopted unless the 

state BART-determining authority 

determines that an alternative control 

level is justified based on a 

consideration of the statutory factors (70 

FR 39171). Given the assessment EPA 

undertook to determine the presumptive 

BART limits and that EPA has 

determined in a formally codified rule 

that they are likely to be suitable as 

BART limits in nearly every 

circumstance to which they applyexcept to the extent states make a 

determination otherwise in a particular 

case- states properly have discretion to 

adopt the presumptive limits. The 

determination as to whether the 

presumptive limits should or should not 

apply is one that is well within the 

discretion of the state. There is little 

reason for EPA to have established the 

presumptive BART limits if states 

cannot rely on them. If EPA requires a 

case-by-case analysis for every facility to 

repeatedly test the assumptions 

underlying the presumptive limits, this 

would result in a senseless approach 

that would vitiate the establishment of 

the presumptive limits. This would be 

contrary to EPA’s own nationally 

applicable regulations developed as a 

product of notice-and-comment 


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19 70 FR 39131. 

20 70 FR 39131. 

21 70 FR 39132. 

22 71 FR 60619. 

rulemaking. If a specific assessment is 

required in every case, there is no 

reason to have a presumptive limit in 

the first place. Regulations, like statutes, 

should not be interpreted in a manner 

that is more stringent than the plain 

language requires. Where there is no 

clear and compelling evidence that 

presumptive limits cannot be BART for 

a given source, EPA should accept state 

BART determinations that rely on the 

presumptive limits. 

Response: The EPA agrees that the 

State has considerable discretion in 

making BART determinations, but if the 

State has not conducted a proper 

evaluation of the five statutory factors, 

as required by 40 CFR 51.308(e)(1)(ii)(A) 

and section 169A(g) of the CAA, the 

State cannot determine that the 

presumptive limits are the ‘‘best 

available retrofit controls’’ for 

Arkansas’s affected sources. With regard 

to the comment that there is little reason 

for EPA to have established presumptive 

emission limits if states cannot rely on 

them, EPA notes that the purpose of the 

presumptive limits in the BART 

Guidelines was to identify controls that 

the Agency considered to be generally 

cost-effective across all affected units. 

Because EPA’s extensive analysis found 

that these controls are generally costeffective across all affected units and 

were anticipated to result in a 

substantial degree of visibility 

improvement, EPA concluded that such 

units should at least meet the 

presumptive limits. Presumptive limits, 

thus, rather than being senseless, 

provide a starting point for a source 

specific analysis. 

We agree that regulations, like 

statutes, should not be interpreted in a 

manner that is more stringent than the 

plain language. However, we do not 

agree that our application of the 

presumptive limit is more stringent than 

what is required under the CAA and the 

RHR. Rather, our application of the 

presumptive limit is in keeping with the 

plain language of the CAA and the RHR. 

Under the RHR, presumptive limits 

were promulgated to provide a path for 

states to follow when analyzing BART 

for particular EGUs. The BART Rule has 

presumptive limits that act as a starting 

point for the establishment of BART 

emission limits unless the state’s 

analysis indicates that an emission limit 

more or less stringent than the 

presumptive limit is required. Please see 

our response to other comments for our 

discussion of the requirements of the 

CAA visibility program and the RHR. 

EPA disagrees that we should accept 

state BART determinations that rely on 

the presumptive limits in every case as 

long as there is no clear and compelling 

evidence that presumptive emission 

limits cannot be BART for a given 

source. There is no language indicating 

this in the CAA, the RHR, or the BART 

Guidelines. On the contrary, EPA’s 

BART Rule and the BART Guidelines 

make clear that in developing the 

presumptive emission limits, EPA made 

many design and technological 

assumptions, and that the presumptive 

limits may not be BART in every case. 

EPA’s intent was for the presumptive 

limits to be used in the State’s BART 

analysis considering the five factors 

specified in CAA section 169A(g)(2), 

and considering the level of control that 

is currently achievable at the time that 

the BART analysis is being conducted. 

Comment: The intent of the RHR was 

to gain reasonable progress in visibility 

improvements in Class I areas, with the 

ultimate goal being to achieve 

background levels of visibility by the 

year 2064. The BART Guidelines 

developed presumptive BART emission 

limits that are cost-effective and capable 

of meeting reasonable progress. ADEQ 

followed EPA’s BART Guidelines in 

establishing presumptive limits as 

BART for the AEP Flint Creek Boiler No. 

1 and Entergy White Bluff Units 1 and 

2. In its proposed rule, EPA ignores its 

own guidance to utilize presumptive 

limits and proposes to go beyond the 

cost-effective presumptive limits at 

Arkansas’s EGUs in the near term and 

to essentially perform a BACT analysis 

for these units, as per EPA’s PSD 

regulations. Going beyond the 

presumptive limits denies the costeffectiveness afforded by the 

presumptive limits and places an 

unnecessary burden on Arkansas 

electricity ratepayers. EPA’s approach is 

beyond what is required to comply with 

the RHR, as requiring standards more 

stringent than EPA’s own presumptive 

limits is unnecessary in order to 

demonstrate reasonable progress. 

Implementing the presumptive limits as 

BART meets the intent of the RHR and 

EPA should accept ADEQ’s proposed 

BART requirements for units subject to 

presumptive limits. 

Response: With regard to the 

comment that the BART Guidelines 

developed presumptive emission limits 

that are cost-effective and capable of 

meeting reasonable progress, EPA notes 

that the RHR states the following 

concerning SO2 and NOX presumptive 

limits: ‘‘Based on our analysis of 

emissions from power plants, we 

believe that applying these highly costeffective controls at the large power 

plants covered by the guidelines would 

result in significant improvements in 

visibility and help to ensure reasonable 

progress toward the national visibility 

goal.’’ 19

The comment appears to suggest that 

a state’s adoption of the presumptive 

limits will result in achieving 

reasonable progress. The EPA notes that 

the RHR stated that applying the highly 

cost-effective controls reflected by the 

presumptive limits would result in 

significant visibility improvement that 

would help to ensure reasonable 

progress, not that it would necessarily 

ensure reasonable progress. 

Furthermore, for a state to achieve 

reasonable progress during the first 

implementation period, it must also 

look at point sources beyond those that 

are subject to BART as well as at nonpoint sources and determine, based on 

consideration of the four statutory 

factors under 40 CFR 51.308(d)(1)(i), 

whether it is reasonable to require these 

sources to install additional pollution 

controls. Therefore, even if a state 

satisfies the BART requirements, 

satisfaction of the reasonable progress 

requirements cannot be met by 

complying with BART requirements 

alone. In addition, the EPA notes that 

the BART Guidelines make clear that 

the presumptive limits may not be 

appropriate for all affected units.20,21,22

The EPA is not ignoring its own 

guidance to utilize presumptive limits, 

as the BART Rule does not suggest the 

presumptive limits should be viewed as 

establishing a safe harbor from more 

stringent regulation under the BART 

provisions. The EPA’s proposed 

rulemaking did not propose particular 

emission limits more stringent than the 

presumptive limits for Arkansas EGUs. 

Instead, the EPA’s proposed rulemaking 

stated that Arkansas must conduct a 

proper evaluation of the five statutory 

factors, as required by 40 CFR 

51.308(e)(1)(ii)(A) and section 169A(g) 

of the CAA, before determining whether 

the presumptive emission limits are the 

‘‘best available retrofit controls’’ for 

affected units. Therefore, the EPA does 

not believe that requiring the State to 

conduct a proper evaluation of the five 

statutory factors places an unnecessary 

burden on Arkansas electricity 

ratepayers. 

The EPA disagrees with the comment 

that EPA is requiring Arkansas to 

perform a PSD BACT analysis for 

affected EGUs. The EPA notes the 

comment is not specific in terms of 

explaining what aspect of our proposed 

rulemaking led to the belief that EPA is 

requiring a PSD BACT analysis for 


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14612 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

23 69 FR 25218. 

24 69 FR 25218. 

25See our proposed rulemaking for the Arkansas 

RH SIP (76 FR 64186). 

26See Appendix Y to Part 51. 

27 64 FR 35740. 

28 70 FR 39,164. 29 70 FR 39,164. 

30 71 FR 60619. 

31 70 FR 39134. 

affected EGUs. However, the proposed 

BART Rule did note that the process for 

a BART analysis is very similar to the 

BACT review as described in the New 

Source Review Workshop Manual 

(Draft, October 1990).23 The proposed 

BART Rule also explained that although 

very similar in process, BART reviews 

differ in many respects from the BACT 

review. The proposed BART Rule 

explained these differences as follows: 

‘‘First, because all BART reviews 

apply to existing sources, the available 

controls and the impacts of those 

controls may differ from source to 

source. Second, the CAA requires you to 

take slightly different factors into 

account in determining BART and 

BACT * * * Because of the differences 

in terminology, the BACT review 

process tends to encompass a broader 

range of factors * * * Finally, for the 

BART analysis, there is no minimum 

level of control required, while any 

BACT emission limitation must be at 

least as stringent as any NSPS that 

applies to the source.’’ 24

Because of the similarities in the two 

processes, it is understandable that 

there may be some misunderstanding 

regarding our proposed rulemaking to 

mean that EPA is requiring subject to 

BART sources to conduct a PSD BACT 

analysis. Our statement that subject to 

BART sources must consider the ‘‘most 

stringent option (i.e. maximum level of 

control each technology is capable of 

achieving) as well a reasonable set of 

options for analysis,’’ 25 may have been 

misinterpreted to mean that we are 

requiring a PSD BACT analysis. We are 

not requiring a PSD BACT analysis. As 

explained in our proposed rulemaking, 

the BART Guidelines provide that in 

identifying all options, you must 

identify the most stringent option (i.e. 

maximum level of control each 

technology is capable of achieving) as 

well as a reasonable set of options for 

analysis.26 The RHR also provides that 

in establishing source specific BART 

emission limits, the State should 

identify and consider in the BART 

analysis the maximum level of emission 

reduction that has been achieved in 

other recent retrofits at existing sources 

in the source category.27 Furthermore, 

the BART Guidelines state that 

‘‘[t]echnologies required as BACT or 

LAER are available for BART 

purposes.’’ 28 The guidelines instruct: 

‘‘You are expected to identify 

potentially applicable retrofit control 

technologies that represent the full 

range of demonstrated alternatives. 

Examples of general information sources 

are to consider include: The EPA’s 

Clean Air Technology center, which 

includes the RACT/BACT/LAER 

Clearinghouse (RBLC) * * *’’ 29 Our 

rulemaking is consistent with the RHR 

and the BART Rule, and does not 

require Arkansas’s subject to BART 

sources to conduct a PSD BACT 

analysis. 

The EPA disagrees with the comment 

that EPA’s approach in our proposed 

rulemaking for the Arkansas RH SIP is 

beyond what is required to comply with 

the RHR and that requiring standards 

more stringent than EPA’s own 

presumptive limits is unnecessary in 

order to demonstrate reasonable 

progress. As already explained 

elsewhere in our response to other 

comments, EPA’s rulemaking on the 

Arkansas RH SIP is not requiring 

Arkansas affected sources to meet 

standards more stringent than the 

presumptive emission limits. Arkansas 

must conduct a proper evaluation of the 

five statutory factors, as required by 40 

CFR 51.308(e)(1)(ii)(A) and section 

169A(g) of the CAA, before determining 

whether the presumptive emission 

limits are the ‘‘best available retrofit 

controls’’ for affected units. 

Furthermore, 40 CFR 51.308(e)(1)(ii)(A) 

and section 169A(g) of the CAA require 

that states consider the five statutory 

factors when making BART 

determinations, and the State cannot 

determine whether or not emission 

limits more stringent than the 

presumptive emission limits are 

necessary to demonstrate reasonable 

progress when a proper evaluation of 

the five statutory factors has not been 

conducted. 

Comment: Appendix Y is very clear 

that when it comes to presumptive 

BART NOX emissions limits for 

qualifying EGUs, Arkansas must require 

these EGUs to meet the presumptive 

BART emissions limits in Appendix Y. 

Not only does Arkansas have broad 

discretion to apply presumptive NOX

limits, but Appendix Y actually requires 

this. Arkansas followed this approach in 

its RH SIP. In its proposed rule, EPA 

now claims that the presumptive limits 

are something completely different than 

the straightforward directive contained 

in the Code of Federal Regulations, 

claiming that they are the starting point 

in a BART determination and that 

sources must ‘‘at least’’ meet these 

emission limits. Using the word ‘‘at 

least’’ implies that presumptive limits 

constitute a minimally acceptable 

degree of control that would constitute 

BART. Nothing in the CAA, RHR, or 

Appendix Y ever states or implies this. 

EPA also stated in its proposal for the 

Arkansas RH SIP that ‘‘nothing on the 

record would support the conclusion 

that the presumptive limits represent 

‘best available retrofit controls’ for all 

EGUs at these large power plants’’ (76 

FR 64201). EPA is attempting to avoid 

the broad statements it previously made 

regarding the applicability of the 

‘‘presumptive BART’’ NOX emissions 

limits. EPA’s statements in previous 

rulemakings demonstrate that in almost 

all cases, the presumptive BART limits 

should apply, and the only instance 

when they should not apply is to 

atypical instances when a source is able 

to show through a five factor test that it 

is not able to meet the presumptive 

emission rates, even if the expected 

control technology were installed. EPA’s 

proposal for the Arkansas RH SIP also 

incorrectly claims that in Appendix Y, 

EPA simply concluded that it could not 

reach a generalized conclusion as to the 

appropriateness of more stringent 

controls for categories of EGUs (76 FR 

64201). EPA’s failure to recognize the 

proper role of presumptive BART NOX

emissions limits is arbitrary and 

capricious because EPA acted in excess 

of statutory jurisdiction, authority, or 

limitations (North Carolina v. EPA, 531 

F.3d 896, 906, DC Circuit 2008). 

Response: The EPA disagrees that 

Appendix Y (i.e. the BART Guidelines) 

makes the presumptive emission limits 

mandatory for all qualifying EGUs. The 

comment that states have broad 

discretion to apply presumptive NOX

limits contradicts the comment that the 

BART Guidelines require states to adopt 

the presumptive limits. The BART 

Guidelines make clear that the 

presumptive emission limits are 

rebuttable.30 Referring to the NOX

presumptive emission limits, the BART 

Rule states that the presumptive 

emission limits may not be appropriate 

for all sources, as they are 

‘‘presumptions only.’’ 31 The 

presumptive emission limits apply to 

power plants with a total generating 

capacity of 750 MW or greater insofar as 

these sources are required to adopt 

emission limits at least as stringent as 

the presumptive limits, unless after 

considering the five statutory factors, 

the State determines that the 

presumptive emission limits are not 

appropriate. Moreover, the CAA, the 

RHR, and the BART Guidelines do not 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14613 

32 70 FR 39132. 

33 76 FR 64201. 

34 70 FR 39131, 39132, and 39134. 

35See 40 CFR 51.308(e)(1)(ii)(A) and 42 U.S.C. 

7491(g)(2). 

36 70 FR 39132. 

37 70 FR 39132. 

38 70 FR 39136. 

exempt the State from a five factor 

BART analysis or even provide the State 

with discretion to determine whether or 

not to conduct an analysis of the five 

statutory factors when the State has 

adopted the presumptive emission 

limits. 

We are not claiming that the 

presumptive emission limits are 

anything else than what is contained in 

the RHR and the BART Guidelines. 

With regard to the comment that 

nothing in the CAA, RHR, or Appendix 

Y ever states or implies that the 

presumptive limits are the starting point 

in a BART determination, EPA notes 

that there is no mention of the 

presumptive emission limits in the 

CAA. Further, in response to comments 

on the proposed BART Guidelines that 

the presumptive SO2 EGU limits should 

be more stringent, EPA justified its 

decision not to establish more stringent 

SO2 presumptive limits, by explaining 

in the preamble to the final BART Rule 

that ‘‘[i]f, upon examination of an 

individual EGU, a State determines that 

a different emission limit is appropriate 

based upon its analysis of the five 

factors, then the State may apply a more 

or less stringent limit.’’ 32 Similar 

statements are made elsewhere in the 

BART Rule. Clearly, the RHR and the 

BART Rule do not suggest the 

presumptive limits should be viewed as 

establishing a safe harbor from more 

stringent regulation under the BART 

provisions. EPA stands by the statement 

made in its proposed rulemaking on the 

Arkansas RH SIP that ‘‘nothing on the 

record would support the conclusion 

that the presumptive limits represent 

‘best available retrofit controls’ for all 

EGUs at these power plants.’’ 33 EPA 

does not find this statement to be 

inconsistent with the RHR and BART 

Guidelines. As already explained above, 

EPA is clear in the BART Rule and the 

BART Guidelines that the presumptive 

limits may not be appropriate for every 

EGU.34

EPA disagrees with the comment that 

the only instance when the presumptive 

emission limits should not apply is to 

atypical instances when a source is able 

to show through a five factor test that it 

is not able to meet the presumptive 

emission rates. The comment suggests 

that for power plants with a total 

generating power capacity greater than 

750 MW, the RHR and the BART Rule 

provide that an evaluation of the five 

statutory factors for these units is 

merely a vehicle for justifying adoption 

of a BART emission limit less stringent 

than the presumptive limit. This is 

clearly not the intent of the RH 

regulations and section 169A(g) of the 

CAA.35 As explained above, in response 

to comments on the proposed BART 

Guidelines that the presumptive SO2

EGU limits should be more stringent, 

EPA justified its decision not to 

establish more stringent presumptive 

emission limits by explaining that after 

considering the five statutory factors, 

States may find that a more or less 

stringent emission limit is BART.36

Similar statements are made elsewhere 

in the BART Rule. The BART Rule 

states the following: 

‘‘We recognize that while some 

scrubber units currently achieve 

reductions greater than 95 percent, not 

all units can do so. The individual units 

that currently achieve greater than 95 

percent control efficiencies do not 

necessarily represent the wide range of 

unit types across the universe of BARTeligible sources * * * In addition, we 

note that the presumption does not limit 

the States’ ability to consider whether a 

different level of control is appropriate 

in a particular case.’’ 37

Further, in the BART Rule, EPA 

justified its decision not to establish 

presumptive NOX limits based on the 

use of selective catalytic reduction 

(SCR) for units other than cyclone units, 

stating the following: 

‘‘For other units, we are not 

establishing presumptive limits based 

on the installation of SCR. Although 

States may in specific cases find that the 

use of SCR is appropriate, we have not 

determined that SCR is generally costeffective for BART across unit types.’’ 38

Therefore, EPA stands by its 

statement in the proposed rulemaking 

on the Arkansas RH SIP that in the 

BART Guidelines, EPA simply 

concluded that it could not reach a 

generalized conclusion as to the 

appropriateness of more stringent 

controls for categories of EGUs. 

The EPA’s application of presumptive 

BART NOX emissions limits to 

Arkansas’s RH BART determinations is 

not arbitrary and capricious, because 

EPA is acting in accordance with the 

CAA and the RHR. The EPA’s 

disapproval of Arkansas’s BART 

determinations that adopted the 

presumptive BART SO2 and NOX

emission limits without conducting a 

proper five factor BART analysis is a 

proper exercise of EPA’s authority 

under the Act. Congress crafted the CAA 

to provide for states to take the lead in 

developing implementation plans 

consistent with the laws and 

regulations, but balanced that decision 

by requiring EPA to review the plans to 

determine whether a SIP meets the 

requirements of the CAA. The EPA’s 

review of SIPs is not limited to support 

and cooperation in implementation of a 

state SIP nor is it to simply approve 

state decisions. When reviewing state 

SIPs, EPA must consider not only 

whether the state considered the 

appropriate factors in making decisions 

but acted reasonably in doing so. In 

undertaking such a review, EPA does 

not usurp the state’s authority but 

ensures that such authority is 

reasonably exercised. EPA has reviewed 

Arkansas’s BART determinations for 

NOX that adopted the presumptive 

limits without conducting a proper five 

factor BART analysis, and we find that 

Arkansas did not follow the 

requirements of the RHR; that is the 

basis for our disapproval of those BART 

determinations. For a more detailed 

explanation of state and EPA authority 

in the development and approval of RH 

SIPs as well as of how EPA’s action does 

not encroach on state authority and is 

consistent with the CAA and the RHR, 

please see our response to comments 

under section III.F, titled ‘‘Comments on 

Legal Issues,’’ of this final rulemaking. 

Comment: The EPA’s treatment of 

presumptive limits in its proposed 

partial disapproval of AR RH SIP is 

inconsistent with EPA’s BART 

Guidelines. EPA departed from the 

BART Guidelines and made the use of 

presumptive limits meaningless when it 

disapproved BART determinations for 

Entergy’s Lake Catherine Unit 4 and 

White Bluff Units 1 and 2 that adopt the 

presumptive limits. When EPA departs 

from the BART Guidelines, it is going 

beyond the scope of the CAA’s visibility 

protection program. For certain 

categories of EGUs, EPA’s BART 

Guidelines provide presumptive limits 

that the states rely upon in making 

BART determinations. The presumptive 

limit framework outlined in the BART 

Guidelines is intended to function like 

presumptive evidence in litigation 

where the evidence is received and 

treated as sufficient until it is 

discredited. Presumptive limits should 

represent BART until and unless they 

are rebutted. This is not how EPA 

approached presumptive limits in 

reviewing the Arkansas RH SIP. The 

BART Guidelines provide that if a state 

wishes to do a case-by-case BART then 

there are presumptive levels of controls 

for SO2 and NOX that can be adopted for 

certain EGUs that the state finds are 


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14614 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

39 70 FR 39158. 40 70 FR 39144. 

subject to BART. This is what Arkansas 

did and should be approved by EPA. 

Response: The EPA disagrees that the 

EPA’s treatment of the presumptive 

limits in its proposed rulemaking on the 

Arkansas RH SIP is inconsistent with 

EPA’s BART Guidelines and made use 

of the presumptive limits meaningless. 

EPA notes that Entergy Lake Catherine 

Unit 4 is currently permitted to burn 

natural gas and fuel oil. EPA’s BART 

Guidelines do not establish presumptive 

emission limits for units that burn 

natural gas and/or fuel oil, therefore the 

ADEQ did not adopt any presumptive 

limits for Entergy Lake Catherine Unit 4. 

With regard to Entergy White Bluff 

Units 1 and 2, as stated in our proposed 

rulemaking on the Arkansas RH SIP, the 

purpose of the presumptive limits in the 

BART Guidelines was to identify 

controls that the Agency considered to 

be generally cost-effective across all 

affected units. Because EPA’s extensive 

analysis found that these controls are 

generally cost-effective across all 

affected units and were anticipated to 

result in a substantial degree of 

visibility improvement, EPA concluded 

that such units should at least meet the 

presumptive limits, unless a more or 

less stringent limit is found to be BART 

after the state considers the five 

statutory factors. EPA’s intent was for 

these generally cost-effective controls to 

be used in the State’s BART analysis 

considering the five factors specified in 

CAA section 169A(g)(2), and 

considering the level of control that is 

currently achievable at the time that the 

BART analysis is being conducted. 

Further, 40 CFR 51.308(e)(1)(ii)(A) 

requires that States identify the level of 

control representing BART after 

considering the five statutory factors set 

out in CAA section 169A(g).39

We disagree that the presumptive 

limits should represent BART until and 

unless they are rebutted. We reiterate 

that nothing on the record states that the 

presumptive limits represent the ‘‘best 

available retrofit controls’’ for all EGUs 

at these large power plants. On the 

contrary, EPA’s BART Rule and the 

BART Guidelines make clear that in 

developing the presumptive emission 

limits, EPA made many design and 

technological assumptions, and that the 

presumptive limits may not be BART in 

every case. 

While the BART Guidelines provide 

that there are presumptive levels of 

controls for SO2 and NOX that can be 

adopted for certain EGUs that the state 

finds are subject to BART, this is true 

only after the state has considered the 

five statutory factors to determine 

whether a more or less stringent 

emission limit is BART. In the BART 

Guidelines, EPA noted that the 

presumptive limits represented current 

control capabilities at the time the 

BART Rule was promulgated, and that 

we expected that scrubber technology 

would continue to improve and control 

costs continue to decline.40 Therefore, 

in their evaluation of the five statutory 

factors, states must consider the level of 

control that is currently achievable at 

the time the BART analysis is being 

conducted. 

The presumptive limit framework 

could be compared to the presumptive 

evidence in litigation. However, the 

comment mischaracterizes the role of 

presumptive evidence in litigation as 

simply to be received and treated as 

sufficient until it is discredited. 

Presumptive evidence is circumstantial 

evidence that creates belief by showing 

surrounding circumstances which 

logically lead to a conclusion of fact. At 

trial, many forms of evidence are 

submitted including circumstantial 

evidence. All forms of evidence that are 

admitted in court are reviewed and 

considered before a decision is made. 

While presumptive evidence may meet 

the sufficiency requirement for 

admission in court, this does not mean 

that it is looked at alone without review 

of the other admitted evidence. 

Presumptive evidence does not trump 

other forms of evidence. It is just a type 

of evidence that is reviewed in reaching 

a court decision. Like presumptive 

evidence, presumptive limits are one 

line of analysis for reaching a decision. 

Like presumptive evidence in the court 

room, presumptive limits are not the 

only limit that is looked at when 

performing the five factor BART 

analysis. Presumptive limits do not 

preempt states from conducting the 

BART analysis nor do they preclude the 

evaluation of other emission limits to 

help the state reach its BART 

determination. 

Comment: The EPA should approve 

the Arkansas RH SIP in its entirety and 

specifically with regards to Arkansas 

adoption of presumptive limits in its 

BART determinations. Modeling 

conducted by Arkansas and CENRAP 

demonstrates that Arkansas’s adoption 

of the presumptive limits is satisfactory 

to make reasonable progress toward the 

national goal by 2018 and ultimately to 

achieve the national goal prior to 2064. 

Response: Presumptive emission 

limits apply to power plants with a total 

generating capacity of 750 MW or 

greater insofar as these sources are 

required to adopt emission limits at 

least as stringent as the presumptive 

limits, unless after considering the five 

statutory factors, the State determines 

that the presumptive emission limits are 

not appropriate. The RHR and the BART 

Guidelines make clear that the 

presumptive limits will not necessarily 

be the appropriate level of control for all 

EGUs. Therefore, EPA is not required to 

approve a state’s submitted presumptive 

emission limits in every instance for 

every EGU as BART. For the reasons 

presented in our proposed rulemaking, 

and as further explained in our response 

to comments, EPA stands by its partial 

approval and partial disapproval of the 

BART determinations in the Arkansas 

RH SIP. 

States are required to satisfy all BART 

requirements in this first 

implementation period regardless of 

whether modeling demonstrates that the 

state will make reasonable progress by 

2018 and meet the national goal by 

2064. As described in our proposed 

rulemaking on the Arkansas RH SIP, we 

find that in adopting the SO2 and NOX

presumptive limits for the AEP Flint 

Creek Boiler No. 1 and Entergy White 

Bluff Units 1 and 2 without conducting 

a proper evaluation of the five statutory 

factors, as required by 40 CFR 

51.308(e)(1)(ii)(A) and section 169A(g) 

of the CAA, Arkansas did not satisfy all 

the BART requirements for these subject 

to BART sources. Furthermore, EPA 

notes that the CENRAP modeled the 

projected visibility conditions 

anticipated at each Class I area in 2018. 

The CENRAP modeling is based on 

emissions reductions expected to result 

from Federal, state, and local control 

programs that are either currently in 

effect or with mandated future-year 

emission reduction schedules that 

predate 2018. The CENRAP modeling 

itself did not show that already 

mandated controls are expected to attain 

natural visibility conditions by 2064. 

Rather, the rate of visibility 

improvement anticipated by the 

CENRAP modeling in 2018, if sustained, 

will result in a return to natural 

visibility prior to 2064. The comment 

that Arkansas is expected to ultimately 

achieve the national goal prior to 2064 

assumes that the same level of 

reductions of visibility-impairing 

pollutants that is expected to occur 

during the first implementation period 

ending in 2018 will increasingly occur 

during each implementation period 

until the final implementation period 

ending in 2064. However, there is no 

guarantee that this will occur. The 

Arkansas RH SIP addresses 

implementation of the RHR only up to 

the end of the first implementation 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14615 

41 70 FR 39134. 

42 71 FR 60619. 

43 70 FR 39134. 44 70 FR 39132. 

period ending in 2018. Therefore, EPA 

disagrees that we should approve 

Arkansas’s adoption of the presumptive 

limits on the basis that modeling 

demonstrates that the State’s adoption 

of the presumptive limits is satisfactory 

to make reasonable progress toward the 

national goal by 2018 and ultimately to 

achieve the national goal prior to 2064. 

Comment: Under the BART 

Guidelines, presumptive limits were 

established as a default requirement 

where the presumption would apply 

unless the state has persuasive evidence 

that an alternative determination is 

justified. According to EPA, the 

presumptive limits reflect highly costeffective controls that are extremely 

likely to be appropriate for all power 

plants subject to BART but may be 

deviated from if a state determines that 

a different emission limit is appropriate 

based upon its analysis of the five 

factors. 76 FR 39131–32. 

Response: As reflected in our 

previous responses to similar 

comments, the proper interpretation of 

the BART Rule and BART Guidelines is 

that presumptive limits are the 

‘‘rebuttable’’ starting point rather than 

the ‘‘default requirement’’ in making 

BART determinations. Referring to the 

NOX presumptive emission limits, the 

BART Rule states that the presumptive 

emission limits may not be appropriate 

for all sources, as they are 

‘‘presumptions only.’’ 41 EPA notes that 

presumptive emission limits apply to 

power plants with a total generating 

capacity of 750 MW or greater insofar as 

these sources are required to adopt 

emission limits at least as stringent as 

the presumptive limits, unless after 

considering the five statutory factors, 

the State determines that the 

presumptive emission limits are not 

appropriate for BART. 

EPA agrees that the BART Rule and 

the BART Guidelines provide that 

presumptive limits reflect controls that 

the Agency considered to be generally 

cost-effective across all affected units. 

Because EPA’s extensive analysis found 

that these controls are generally costeffective across all affected units and 

were anticipated to result in a 

substantial degree of visibility 

improvement, they may likely be 

appropriate for all Arkansas power 

plants subject to BART, but Arkansas 

must establish different BART emission 

limits if an evaluation of the five 

statutory factors reveals that such 

emission limit is appropriate. However, 

as discussed in our proposed 

rulemaking, Arkansas did not conduct a 

proper evaluation of the five statutory 

factors for its sources. Therefore, it is 

not possible to know whether the 

presumptive emission limits or an 

alternative emission limit is BART for 

the affected sources. 

Comment: The approach in EPA’s 

proposed rule to presumptive limits as 

a starting point is inconsistent with the 

BART Guidelines. The Guidelines do 

not state that presumptive limits are a 

starting point for a BART determination, 

but instead establish a presumption in 

favor of the presumptive limits. 

Presumptive limits serve no purpose if 

their adoption does not presume 

compliance with the applicable 

regulations. The EPA’s inconsistent 

application of its own guidelines fosters 

regulatory uncertainty among the EGU 

industry. 

Response: The EPA disagrees that our 

approach to presumptive limits as a 

starting point in EPA’s proposed rule is 

inconsistent with the BART Guidelines 

and that the presumptive limits serve no 

purpose if their adoption does not 

presume compliance with the 

regulations. As stated in our proposed 

rulemaking on the Arkansas RH SIP, the 

purpose of the presumptive limits in the 

BART Guidelines was to identify 

controls that the Agency considered to 

be generally cost-effective across all 

affected units. Because EPA’s extensive 

analysis found that these controls are 

generally cost-effective across all 

affected units and were anticipated to 

result in a substantial degree of 

visibility improvement, EPA concluded 

that such units should at least meet the 

presumptive limits. EPA’s intent was for 

these generally cost-effective controls to 

be used in the State’s BART analysis 

considering the five factors specified in 

CAA section 169A(g)(2), and 

considering the level of control that is 

currently achievable at the time that the 

BART analysis is being conducted. The 

BART Rule makes clear that the 

presumptive emission limits in the 

BART Guidelines are rebuttable.42

Referring to the NOX presumptive 

emission limits, the BART Rule states 

that the presumptive emission limits 

may not be appropriate for all sources, 

as they are ‘‘presumptions only.’’ 43

Further, in response to comments on the 

proposed BART Guidelines that the 

presumptive SO2 EGU limits should be 

more stringent, EPA explained in the 

preamble to the final BART Rule that 

‘‘[i]f, upon examination of an individual 

EGU, a State determines that a different 

emission limit is appropriate based 

upon its analysis of the five factors, then 

the State may apply a more or less 

stringent limit.’’ 44 Similar statements 

are made elsewhere in the BART Rule. 

It is important that, in analyzing the 

technology, states take into account the 

most stringent emission control level 

that the technology is capable of 

achieving. States should be sure to 

consider the level of control that is 

currently achievable at the time that the 

BART analysis is being conducted. 

Thus, the BART Guidelines require that 

potential emission limits that are more 

stringent than the presumptive limits 

must be examined as part of the BART 

determination. 

Comment: The EPA’s proposed 

disapproval of Arkansas’s adoption of 

presumptive limits for some of its BART 

determinations is inconsistent with 

EPA’s acceptance of presumptive limits 

in other states’ BART determinations 

such as Kansas, North Dakota, and 

Oklahoma. The EPA has not identified 

a rationale or reason for this 

inconsistency. The lack of consistency 

in its analyses for states’ RH SIPs is a 

cause of concern. Applying different 

standards and/or rendering different 

decisions on similar SIPs when there is 

no basis for differentiation is by 

definition arbitrary and capricious, and 

therefore invalid. Instead of arbitrarily 

applying different standards, EPA 

should use its own guidelines to 

implement the RH program on a 

consistent, cost-effective basis. For 

Kansas, the EPA approved the Kansas 

RH SIP including the adoption of SO2

and NOX presumptive limits for non-oil 

or gas-fired units similar in design and 

capacity to Arkansas’s units. The Kansas 

RH SIP also included language, which 

EPA approved, that presumptive limits 

are cost effective in most cases, and if 

a facility proposed controls at or beyond 

the presumptive limits, it need not take 

into account the remaining statutory 

factors as BART will be met. In 

addition, the SIP also stated that 

allowing facilities to use presumptive 

limits to meet BART is within its 

authority under the RH program. This 

contradicts the EPA’s proposed 

disapproval of the Arkansas RH SIP 

where EPA states that presumptive 

limits are the starting point in a BART 

determination for these units. For North 

Dakota, EPA proposed to approve the 

BART determinations that SO2 and NOX

presumptive limits is BART for facilities 

that are similar in use of fuel and 

capacity to Arkansas’s units. For 

Oklahoma, the EPA has proposed to 

approve those portions of Oklahoma’s 

SIP which adopt the presumptive 

emissions limits for NOX set forth in the 

Guidelines as BART for the subject 


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14616 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

45 76 FR 64206. 

46 76 FR 52616. 

47 76 FR 52616. 

48 76 FR 52617. 

49 76 FR 80754. 

50 76 FR 80754. 

units. This contradicts EPA’s approach 

for this proposed rule since EPA is 

proposing to disapprove the NOX BART 

presumptive limit for Arkansas’s units 

even though the units are similar in 

design and capacity to the subject units 

in Oklahoma and Arkansas considered 

the same BART factors as Oklahoma. 

EPA’s simultaneous proposed approval 

of other states’ SIPs which use 

presumptive limits in a manner similar 

to Arkansas and proposed disapproval 

of those portions of Arkansas’s SIP 

demonstrates that EPA is acting 

inconsistently and has exceeded its 

limited authority in implementation of 

the visibility protection program. 

Response: The EPA disagrees that 

there is an inconsistency between our 

approach to presumptive limits in our 

proposed rulemaking on the Arkansas 

RH SIP and that in our proposed 

rulemaking on the North Dakota RH SIP 

and final rulemakings on the Kansas 

and Oklahoma RH SIPs. Our action on 

the Arkansas RH SIP is not arbitrary and 

capricious. 

In the Arkansas RH SIP, the State 

adopted the NOX and SO2 presumptive 

emission limits for BART without 

conducting any form of BART analysis 

for AEP Flint Creek Boiler No. 1. For 

Entergy White Bluff Units 1 and 2, the 

State conducted a five factor BART 

analysis for SO2 and NOX, which we 

find does not appropriately consider all 

five statutory factors at 40 CFR 

51.308(e)(1)(ii)(B); as such, EPA 

proposed to disapprove the State’s 

determination that the presumptive SO2

and NOX emission limits are BART for 

these two units.45 As explained in more 

detail in our proposed rulemaking, the 

factors that EPA is finding were not 

appropriately considered in the NOX

and SO2 BART analyses for White Bluff 

Units 1 and 2 are the available control 

technology and the cost and visibility 

impact of controls beyond the 

presumptive limits. For NOX BART, 

Arkansas evaluated only combustion 

controls to achieve the NOX

presumptive emission limit. For SO2

BART, Arkansas evaluated both 

combustion and post-combustion 

controls, but evaluated the cost and 

visibility impact of operating postcombustion controls (i.e. wet and dry 

scrubbers) to achieve theSO2

presumptive emission limit only. As 

explained in our proposed rulemaking, 

Arkansas did not evaluate NOX and SO2

controls to achieve emission limits 

beyond the presumptive limits, and we 

believe it is very likely that a proper five 

factor analysis would demonstrate that 

controls that achieve NOX and SO2

emission limits more stringent than 

presumptive limits are cost-effective for 

White Bluff Units 1 and 2. Therefore, we 

are disapproving the SO2 and NOX

presumptive emission limits for Flint 

Creek Boiler No. 1 and White Bluff 

Units 1 and 2 not because the State 

adopted the presumptive emission 

limits, but rather because the State did 

not conduct a proper evaluation of the 

five statutory factors when making these 

BART determinations. 

In contrast, in our evaluation of the 

Oklahoma RH SIP, EPA found that 

Oklahoma conducted proper BART 

analyses before determining that NOX

presumptive limits are BART for some 

sources. In our final rulemaking action 

on the Oklahoma RH SIP, EPA approved 

the State’s NOX BART determinations 

for Units 1 and 2 at OG&E Sooner; Units 

4 and 5 at OG&E Muskogee; and Units 

3 and 4 at AEP/PSO Northeastern. For 

each of these sources, the State made its 

NOX BART determination based on an 

evaluation of a number of controls, 

including post-combustion controls 

operated to achieve an emission limit 

beyond the NOX presumptive limit. 

Based on an evaluation of the five 

statutory factors, Oklahoma determined 

that the NOX presumptive limit is BART 

for these sources. In our action on the 

Oklahoma RH SIP, we approved the 

NOX presumptive limits as BART for 

these sources because Oklahoma’s NOX

BART analyses were appropriate and 

met the requirements of the RHR and 

CAA. 

In our proposed approval of the 

Kansas RH SIP, we noted that each of 

Kansas’s subject to BART sources are 

EGUs greater than 200 MW in capacity 

and located at power plants with a total 

capacity greater than 750 MW, which 

are units for which EPA established 

presumptive BART emission limits.46

Consistent with our proposed 

rulemaking on the Arkansas RH SIP, in 

our proposed rulemaking for Kansas, we 

stated that such units must as a general 

matter at least meet the presumptive 

emission limits as described in the 

BART Guidelines, unless an evaluation 

of the five statutory factors 

demonstrated that an alternative level of 

control was appropriate.47 The State of 

Kansas performed an evaluation of the 

five statutory factors for each source 

subject to BART, evaluating the costs 

and visibility impact of both 

combustion and post-combustion 

controls.48 In fact, the Kansas BART 

evaluation for some units resulted in the 

adoption of BART emission limits more 

stringent than the NOX and SO2

presumptive limits.49 Based on an 

evaluation of the five factors, the State 

of Kansas determined, and EPA 

proposed to approve the NOX and SO2

presumptive limits for some units. 

During the public comment period for 

our proposed approval of the Kansas RH 

SIP, we received comments stating that 

the Kansas RH SIP was incomplete and 

insufficient because the State did not 

evaluate the cost and visibility 

improvement resulting from the most 

stringent emission limit capable of being 

achieved by the various SO2 and NOX

controls considered for these units. 

Subsequently, the State provided EPA 

information on the cost and visibility 

impact of operating the various NOX

and SO2 control technologies 

considered by the State at an emission 

rate more stringent than the 

presumptive limits. The information 

provided by the State demonstrated that 

operation of these controls to achieve an 

emission limit more stringent than the 

presumptive limit would result in high 

costs and very low visibility 

improvement, and thereby not be costeffective. Based upon its evaluation of 

the State’s five factor supplemented 

analysis, EPA agreed with Kansas that it 

is reasonable to determine that the cost 

of further control beyond presumptive 

limits is not warranted and finalized its 

proposed approval of the Kansas RH SIP 

without changes.50 In particular, for the 

Westar Jeffrey Units 1 and 2, EPA agreed 

with the State of Kansas that given the 

very low visibility improvement 

modeled for the additional SO2 control 

(i.e. operating a scrubber at a control 

efficiency that would achieve an 

emission rate of 0.05 lb/MMBtu instead 

of the presumptive emission rate of 0.15 

lb/MMBtu), it is not reasonable to 

establish an SO2 emission limit more 

stringent than the presumptive limit. 

Arkansas has not provided EPA with 

information demonstrating that 

operation of SO2 and NOX controls to 

achieve an emission limit more 

stringent than the presumptive limits is 

not cost-effective for Flint Creek Boiler 

No. 1 and White Bluff Units 1 and 2. 

Since controls capable of achieving a 

more stringent emission limit than the 

NOX and SO2 presumptive limits have 

been found to be technically feasible 

and cost-effective at similar sources, the 

State must evaluate these controls in its 

BART analysis. Therefore, EPA’s final 

approval of the NOX and SO2

presumptive limits for some EGUs in 

Kansas is not inconsistent with our 

proposed disapproval of the NOX and 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14617 

51 76 FR 52604, at 52616. 

52The BART Guidelines provide that States must 

require 750 MW power plants to meet specific 

control levels for SO2 of either 95% control or 0.15 

lb/MMBtu, for each EGU greater than 200 MW that 

is currently uncontrolled unless you determine that 

an alternative control level is justified based on a 

careful consideration of the statutory factors 

(Appendix Y to Part 51, section IV.E.4.). 

53 76 FR 58570, at 58586 and 58587. 

54 76 FR 58570, at 58589. 

SO2 presumptive limits for White Bluff 

Units 1 and 2 and Flint Creek Boiler No. 

1. With regard to the comment that the 

Kansas RH SIP included language that 

that if a subject facility proposes 

controls at or beyond the presumptive 

limits then BART will be met and that 

allowing facilities to use presumptive 

limits to meet BART is within the 

State’s authority under the RH program, 

EPA notes that although the Kansas RH 

SIP did include such language, EPA did 

not approve or propose to approve the 

BART determinations by Kansas based 

on such reasoning. EPA notes that 

Kansas supplemented its BART 

evaluation by providing additional 

information on the costs and visibility 

impacts associated with various NOX

and SO2 control technologies. This 

additional information constituted an 

important part of the basis for EPA’s 

approval of the Kansas RH SIP. As a 

general matter, in evaluating a SIP 

submittal, EPA considers the state’s 

rationale for its determinations but 

reaches a decision as to whether a SIP 

meets the relevant statutory and 

regulatory requirements based on 

consideration of other factors as well. 

EPA’s approval of a SIP does not mean 

that EPA has determined that every 

statement or analysis provided by the 

state was appropriate or reasonable or 

that EPA agrees with the state’s 

interpretation of the relevant legal 

requirements. Furthermore, the 

preamble to our proposed rulemaking 

on the Kansas RH SIP states that as 

presumptive units, each of Kansas’ five 

subject to BART units ‘‘must as a 

general matter at least meet the 

presumptive emission limits as 

described in the BART Guidelines.’’ 51

This is consistent with statements made 

in the preamble to our proposed 

rulemaking on the Arkansas RH SIP. 

EPA believes that our approach to 

presumptive limits in our final action 

on the Kansas RH SIP is consistent with 

that in our action on the Arkansas RH 

SIP. 

While the SO2 controls evaluated by 

North Dakota for the Great River Energy 

Coal Creek Station Units 1 and 2 are not 

expected to achieve an emission limit 

more stringent than the SO2

presumptive emission limit, EPA 

disagrees that our approach to 

presumptive limits in our proposed 

action on North Dakota’s BART 

determinations for the Coal Creek 

Station Units 1 and 2 is inconsistent 

with that in our proposed action on 

Arkansas’s BART determinations for 

Flint Creek Boiler 1 and White Bluff 

Units 1 and 2. First of all, the SO2

presumptive limits do not apply to 

North Dakota’s Coal Creek Station Units 

1 and 2, as the presumptive limits do 

not apply to coal-fired units with 

existing SO2 post-combustion 

controls.52 The Coal Creek Station Units 

1 and 2 have existing wet scrubbers, and 

as such, the cost effectiveness (on a 

dollar/tons reduced basis) of additional 

controls and/or upgrades to the existing 

scrubbers may not be as cost-effective as 

the installation and operation of a new 

scrubber would be at a unit with no 

existing post-combustion controls (as is 

the case with Arkansas’s Flint Creek 

Boiler No. 1 and White Bluff Units 1 

and 2). In addition, we note that the 

Coal Creek Station Units 1 and 2 burn 

pulverized lignite coal, while Flint 

Creek Boiler No. 1 burns low sulfur 

western coal (i.e. sub-bituminous coal) 

and White Bluff Units 1 and 2 burn subbituminous and bituminous coal. 

Lignite coal generally has higher sulfur 

content than sub-bituminous and 

bituminous coal, and therefore, its 

combustion produces a greater amount 

of SO2 emissions. As such, the operation 

of a given control technology, in this 

case a wet scrubber, at a lignite firing 

unit (such as North Dakota’s Coal Creek 

Station Units 1 and 2) may not 

necessarily achieve an emission limit as 

stringent as that capable of being 

achieved at a unit burning subbituminous and/or bituminous coal 

(such as Arkansas’s Flint Creek Boiler 

No. 1 and White Bluff Units 1 and 2). 

In light of the above, we believe that our 

approach to presumptive limits in our 

proposed action on the North Dakota RH 

SIP is not inconsistent with that in our 

proposed action on the Arkansas RH 

SIP. 

As articulated in our proposed 

rulemaking on the North Dakota RH SIP, 

the Great River Energy Stanton Unit 1 is 

located at a 188 MW power plant. 

Therefore, presumptive NOX and SO2

emission limits do not apply to Stanton 

Unit 1. As shown in Tables 7 and 8 of 

our proposed rulemaking on the North 

Dakota RH SIP, in its five factor analyses 

for SO2 for this unit (for both the lignite 

and the Powder River Basin coal firing 

scenarios), North Dakota considered a 

number of post-combustion control 

options, several of which were expected 

to achieve an emission limit more 

stringent than the SO2 presumptive 

limit, including one of which would 

achieve 95% control efficiency.53 Based 

on its consideration of the five statutory 

factors, North Dakota determined that 

an SO2 emission limit of 0.24 lb/MMBtu 

for lignite burning and an emission limit 

of 0.16 lb/MMBtu for Powder River 

Basin coal burning is BART for SO2. For 

NOX for Stanton Unit 1, North Dakota 

evaluated both combustion and postcombustion controls for both the lignite 

and Powder River Basin Coal burning 

scenarios. In its evaluation of controls, 

North Dakota considered the operation 

of selective non-catalytic reduction 

(SNCR) to achieve a control efficiency of 

90% for lignite burning and 88% for 

Powder River Basin coal burning, which 

corresponds to an emission limit 

beyond the NOX presumptive limit. 

Based on its consideration of the five 

statutory factors, North Dakota 

determined that a NOX emission limit of 

0.29 lb/MMBtu for lignite burning and 

0.23 lb/MMBtu for Powder River Basin 

coal burning is BART for NOX. In our 

proposal, we did not identify any flaws 

with North Dakota’s BART analyses for 

NOX and SO2 for this unit, and 

proposed to approve North Dakota’s 

BART determinations. EPA’s approach 

to presumptive limits in our proposed 

action on North Dakota’s BART 

determinations for the Great River 

Energy Stanton Unit 1is not inconsistent 

with that in our proposed action on the 

Arkansas BART determinations for 

White Bluff Unit 1 and 2 and Flint 

Creek Boiler No. 1 because North Dakota 

considered controls beyond the NOX

and SO2 presumptive emission limits. 

This was not done by Arkansas in the 

NOX and SO2 BART analyses for White 

Bluff Units 1 and 2 and Flint Creek 

Boiler No. 1. Furthermore, presumptive 

NOX and SO2 emission limits do not 

apply to Stanton Unit 1. 

North Dakota’s Minnkota Power 

Cooperative Milton R. Young Station 

Unit 1 has no existing SO2 postcombustion controls, while Unit 2 has 

an existing wet scrubber for control of 

SO2. As such, the SO2 presumptive 

limits don’t apply to Unit 2. As shown 

in Table 12 of our proposed rulemaking 

on the North Dakota RH SIP, for Milton 

R. Young Station Unit 1, North Dakota 

considered post combustion controls 

that were expected to achieve 95% 

control efficiency, which corresponds to 

an emission limit more stringent than 

the SO2 presumptive limit.54 As shown 

in Table 13 of our proposed rulemaking 

on the North Dakota RH SIP, for Milton 

R. Young Station Unit 2 North Dakota 

considered upgrades to the existing wet 

scrubber that were expected to achieve 


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14618 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

55 76 FR 58570, at 58590. 

56The BART Guidelines provide that States must 

require 750 MW power plants to meet specific 

control levels for SO2 of either 95% control or 0.15 

lb/MMBtu, for each EGU greater than 200 MW that 

is currently uncontrolled unless you determine that 

an alternative control level is justified based on a 

careful consideration of the statutory factors 

(Appendix Y to Part 51, section IV.E.4.). 

57 76 FR 58570, at 58593. 

58See ‘‘BART Analysis for the White Bluff Steam 

Electric Station,’’ dated December 2006 and 

prepared by Robert Paine, found in Appendix 9.3A 

of the Arkansas RH SIP. 

95% control efficiency, which 

corresponds to an emission limit 

beyond the SO2 presumptive limit.55 In 

our proposed rulemaking on the North 

Dakota RH SIP, we did not identify any 

flaws with North Dakota’s SO2 BART 

analysis for these units. In light of the 

fact that SO2 presumptive limits don’t 

apply to Milton R. Young Station Unit 

2 and that North Dakota evaluated 

controls to achieve 95% control 

efficiency for both Units 1 and 2, which 

corresponds to an emission limit more 

stringent than the SO2 presumptive 

limit, we believe that EPA’s approach to 

presumptive limits in our proposed 

action on North Dakota’s BART 

determinations for Minnkota Power 

Cooperative Milton R. Young Station 

Unit 1 and 2 is not in conflict with that 

in our proposed action on Arkansas’s 

BART determinations for White Bluff 

Units 1 and 2 and Flint Creek Boiler No. 

1. 

While the SO2 controls evaluated by 

North Dakota for the Basin Electric 

Power Cooperative Leland Olds Station 

Units 1 and 2, which are located at a 

656 MW coal fired power plant, are not 

expected to achieve an emission limit 

more stringent than the SO2

presumptive emission limit, EPA 

disagrees that our approach to 

presumptive limits in our proposed 

action on North Dakota’s BART 

determinations for the Leland Olds 

Station Unit 1 and 2 is inconsistent with 

that in our proposed action on 

Arkansas’s BART determinations for 

Flint Creek Boiler No. 1 and White Bluff 

Units 1 and 2. As with the Great River 

Energy Stanton Unit 1, the SO2 and NOX

presumptive limits do not apply to 

North Dakota’s Leland Olds Station 

Units 1 and 2, as the presumptive limits 

do not apply to coal fired power plants 

with a total generating capacity less 

than 750 MW.56 As shown in Table 17 

of our proposed rulemaking on the 

North Dakota RH SIP, for Leland Olds 

Station Unit 1 North Dakota considered 

both NOX combustion and postcombustion controls capable of 

achieving 80% control efficiency, which 

corresponds to an emission limit much 

more stringent than the NOX

presumptive limit.57 In our proposed 

rulemaking on the North Dakota RH SIP, 

we did not identify any flaws with 

North Dakota’s BART analysis for NOX

for Unit 1 and proposed to approve 

North Dakota’s determination that 

BART for NOX is 0.19 lb/MMBtu for 

Leland Olds Station Unit 1. EPA’s 

approach to presumptive limits in our 

proposed action on North Dakota’s 

BART determination for NOX for the 

Leland Olds Station Unit 1 is not 

inconsistent with that in our proposed 

action on Arkansas’s BART 

determinations for Flint Creek Boiler 

No. 1 and White Bluff Units 1 and 2 

because in its evaluation of controls for 

NOX for Unit 1 (for which we did not 

propose to find any flaws), North Dakota 

considered controls beyond the NOX

presumptive emission limits. This was 

not done by Arkansas in the NOX and 

SO2 BART analyses for White Bluff 

Units 1 and 2 and Flint Creek Boiler No. 

1. Furthermore, the NOX and SO2

presumptive limits do not apply at the 

Leland Olds Station Units 1 and 2. 

In summary, EPA disagrees that there 

is an inconsistency between our 

approach to presumptive limits in our 

proposed rulemaking on the Arkansas 

RH SIP and that in our proposed 

rulemaking on the North Dakota RH SIP 

and final rulemakings on the Kansas 

and Oklahoma RH SIPs. 

Comment: The process used by the 

State of Arkansas in adopting the 

presumptive emission limits set forth in 

EPA’s BART Guidelines as BART for 

Entergy White Bluff was improper. The 

record reflects that neither ADEQ nor 

the APCEC conducted its analysis of the 

statutory factors required to establish 

BART, but merely adopted EPA’s 

presumptive limits as proposed by the 

owners and operators of the Entergy 

White Bluff Units 1 and 2. The record 

does not reflect that any analysis was 

done by ADEQ to determine if the 

estimated operating cost and the 

projected cost per deciview (dv) 

improvement for wet scrubbing control 

technology for the White Bluff plant 

were realistic, whether those costs were 

consistent with the cost assumptions 

underlying EPA’s development of 

presumptive limits in the BART 

Guidelines, or whether other options 

were available to address RH concerns 

or whether existing control technology 

at White Bluff was sufficient. Moreover, 

after Arkansas’s RH SIP was adopted by 

the APCEC, Entergy submitted a revised 

2008 BART analysis to ADEQ that 

reflected a more than 300% increase in 

the costs of compliance for the White 

Bluff facility. After this, Entergy filed 

with the Arkansas Public Service 

Commission a claim that the RHR 

compliance costs for White Bluff would 

exceed $1 billion. Nothing in the record 

indicates that Arkansas considered 

these increased costs in establishing 

BART emission limits for Entergy White 

Bluff in the Arkansas RH SIP. In 

addition, EPA was not aware or did not 

consider Entergy’s 2008 revised BART 

analysis for White Bluff. 

Response: The EPA agrees that the 

Arkansas BART determination for 

Entergy White Bluff Units 1 and 2 was 

flawed. As described in our proposed 

rulemaking, the State failed to 

adequately consider controls and BART 

emission limits beyond the presumptive 

limits and the State did not determine 

that the general assumptions underlying 

the EPA’s analysis of presumptive limits 

in its 2005 BART Rule were not 

applicable to White Bluff. As to the 

revised 2008 BART analysis for White 

Bluff, which the source submitted to 

ADEQ, EPA notes that the Arkansas RH 

SIP submittal that EPA received from 

the State on September 23, 2008, 

contains a BART analysis for White 

Bluff dated December 2006.58 The 

Arkansas RH SIP submittal does not 

contain the revised 2008 BART analysis 

for White Bluff, nor was the revised 

2008 BART analysis for White Bluff ever 

submitted to EPA by the State as an 

official RH SIP revision. Given this, EPA 

has not taken the revised analysis into 

account in evaluating the Arkansas RH 

SIP. 

Comment: The process used by the 

State of Arkansas in adopting the 

presumptive emission limits set forth in 

EPA’s Guidelines as BART for Flint 

Creek Boiler No. 1 was improper. For 

the Flint Creek facility, there is no 

BART analysis or other information that 

indicates the actual costs of various 

control technologies or other options for 

addressing RH concerns, and there is 

nothing in the record that reflects that 

ADEQ considered the actual costs of 

controls at the Flint Creek plant in its 

determination of BART for this facility. 

This is due to Arkansas’s improper 

adoption and reliance on EPA’s 

presumptive limits. 

Response: The EPA agrees that the 

process used by Arkansas in adopting 

the NOX and SO2 presumptive emission 

limits set forth in EPA’s Guidelines for 

BART for Flint Creek Boiler No. 1 was 

improper. The State did not consider 

the costs of controls or any of the other 

statutory factors, as required under the 

RHR and the Act, when making its 

BART determinations for this source. 

For this reason we are finalizing our 

proposed disapproval of the States’ NOX


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14619 

59These documents can be found in the docket 

for our rulemaking. 60 70 FR 39116. 

61 71 FR 60619. 

62 70 FR 39132. 

and SO2 BART determinations for Flint 

Creek Boiler No. 1. 

Comment: The EPA approval of the 

PM BART determination for Flint Creek 

Boiler No. 1 in which BART analysis 

was not conducted because visibility 

impacts are minimal contradicts EPA’s 

later rejection of presumptive limits for 

failure to conduct a full BART analysis 

for NOX and SO2 at the same facility. 

Response: Our proposed approval of 

the PM BART determination for the AEP 

Flint Creek Boiler No. 1 does not 

contradict our proposed disapproval of 

the NOX and SO2 presumptive limits for 

the same source. In our review of the 

Arkansas RH SIP, we evaluated the 

determination by ADEQ that no 

additional PM controls are required at 

the Flint Creek Boiler No. 1. ADEQ’s 

determination was based on the precontrol modeling performed by ADEQ 

and a review of AEP SWEPCO’s 

statement that the PM visibility 

modeling did not ‘‘trip the BART impact 

threshold.’’ We reviewed the pre-control 

modeling preformed by ADEQ using the 

24-hr actual maximum emissions from 

the baseline period. The modeling 

results in Appendix 9.2B of the 

Arkansas RH SIP and presented in Table 

7–6 of Appendix A of the Technical 

Support Document (TSD),59 indicate 

that PM contributes less than 0.5% of 

the total visibility impacts from Flint 

Creek Boiler No. 1 at all nearby Class I 

areas with the exception of Upper 

Buffalo. PM contributions to visibility 

impacts at Upper Buffalo from Flint 

Creek are less than 2% of the total 

visibility impairment at this Class I area. 

On the most impacted day at Upper 

Buffalo, modeling the 24-hr actual 

maximum emissions demonstrates that 

PM contributes only 0.07 dv of the total 

3.781 dv modeled visibility impact from 

the source. As stated in the proposal, we 

found that the visibility impact from PM 

emissions alone is so minimal such that 

the installation of any additional PM 

controls on the unit (including any 

upgrades to the existing controls) could 

only have minimal visibility benefit and 

therefore would not be justified. This is 

in keeping with the BART Rule, which 

states the following: 

‘‘Consistent with the CAA and the 

implementing regulations, States can adopt a 

more streamlined approach to making BART 

determinations where appropriate. Although 

BART determinations are based on the 

totality of circumstances in a given situation, 

such as the distance of the source from a 

Class I area, the type and amount of pollutant 

at issue, and the availability and cost of 

controls, it is clear that in some situations, 

one or more factors will clearly suggest an 

outcome. Thus, for example, a State need not 

undertake an exhaustive analysis of a 

source’s impact on visibility resulting from 

relatively minor emissions of a pollutant 

where it is clear that controls would be costly 

and any improvements in visibility resulting 

from reductions in emissions of that 

pollutant would be negligible. In a scenario, 

for example, where a source emits thousands 

of tons of SO2 but less than one hundred tons 

of NOX, the State could easily conclude that 

requiring expensive controls to reduce NOX

would not be appropriate. In another 

situation, however, inexpensive NOX

controls might be available and a State might 

reasonably conclude that NOX controls were 

justified as a means to improve visibility 

despite the fact that the source emits less 

than one hundred tons of the pollutant.’’ 60

Clearly, the most effective controls to 

address visibility impairment from the 

source are those that would reduce 

emissions of visibility impairing 

pollutants other than direct emissions of 

PM. Therefore, we are finalizing our 

proposed disapproval of the NOX and 

SO2 BART determinations for Flint 

Creek Boiler No. 1, as ADEQ did not 

properly identify and evaluate NOX and 

SO2 controls to address visibility 

impairment from the source. As 

explained elsewhere in our response to 

comments, this is consistent with the 

BART Guidelines and with our action 

on other state’s RH SIPs. 

Comment: The EPA’s 2004 proposed 

RHR provided extensive technical 

justification to establish that the 

presumptive limits represent cost 

effective technologies equivalent to 

BART. In addition, the 2004 proposed 

RHR provides that the adoption of the 

presumptive limits by the state is 

acceptable unless the states choose to 

conduct a BART analysis to support 

different limits. Arkansas relied on the 

2004 proposed RHR to adopt 

presumptive limits, along with 

consultation with BART-eligible sources 

to determine whether any site-specific 

factors vary significantly from those 

examined by EPA. Since no factors have 

been identified by the affected sources, 

Arkansas adopted EPA’s presumptive 

limit without any further analysis. That 

is all that is required under the RHR. 

Response: The EPA agrees that we 

went through extensive analysis to 

provide presumptive BART emission 

limits. As stated in our proposed 

rulemaking on the Arkansas RH SIP, the 

purpose of the presumptive limits in the 

BART Guidelines was to identify 

controls that the Agency considered to 

be generally cost-effective across all 

affected units. Because EPA’s extensive 

analysis found that these controls are 

generally cost-effective across all 

affected units and were anticipated to 

result in a substantial degree of 

visibility improvement, EPA concluded 

that such units should at least meet the 

presumptive limits. However, the RHR 

and the BART Guidelines make clear 

that the presumptive limits are 

rebuttable.61 As discussed elsewhere in 

our response to comments, the RHR and 

the BART Guidelines make clear that 

the presumptive limits will not 

necessarily be the appropriate level of 

control for all EGUs. Therefore, EPA 

cannot approve any BART 

determination that relies upon the 

presumptive emission limit unless the 

five factor BART analysis shows the 

presumptive emission limit meets 

BART. EPA disagrees that the 2004 

proposed RHR provides that the 

adoption of the presumptive limits by 

the state is acceptable unless the state 

chooses to conduct a BART analysis to 

support different limits. The RHR (in 

some instances referred to in the 

comment as the BART Rule) and the 

BART Guidelines do not provide that a 

state may choose to conduct a BART 

analysis to support different limits. The 

RHR states the following concerning 

presumptive limits: 

‘‘If, upon examination of an 

individual EGU, a State determines that 

a different emission limit is appropriate 

based upon its analysis of the five 

factors, then the State may apply a more 

or less stringent limit.’’ 62

There is similar language elsewhere in 

the RHR and the BART Guidelines. The 

RHR and the BART Guidelines do not 

contain language giving the State 

discretion to determine whether or not 

to conduct a five factor BART analysis 

when the presumptive emission limits 

have been adopted. 

The EPA disagrees that reliance on 

the 2004 proposed RHR to adopt 

presumptive limits along with 

consultation with subject to BART 

sources to determine whether any sitespecific factors vary significantly from 

those examined by EPA is all Arkansas 

is required to do to satisfy the BART 

requirements under the RHR. The RHR 

states that for each source subject to 

BART, states are required to identify 

BART after considering the five 

statutory factors in CAA section 

169A(g), as follows: 

‘‘States must identify the best system of 

continuous emission control technology for 

each source subject to BART taking into 

account the technology available, the costs of 

compliance, the energy and non-air quality 

environmental impacts of compliance, any 

pollution control equipment in use at the 


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14620 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

63 70 FR 39158. 

64 70 FR 39131. 

65 70 FR 39132. 

66See 40 CFR 51.308(e)(1)(ii)(A) and 42 U.S.C. 

7491(g)(2). 

67 70 FR 39171. 

68See 40 CFR 51.308(e)(1)(ii)(A) and 42 U.S.C. 

7491(g)(2). 

69 70 FR 39171. 

source, the remaining useful life of the 

source, and the degree of visibility 

improvement that may be expected from 

available control technology.’’ 63

Therefore, adoption of the NOX and 

SO2 presumptive limits alone does not 

satisfy the requirements of the RHR and 

the CAA. 

Comment: The EPA’s 2004 proposed 

RHR supports the position that the 

presumptive limits identified in the 

RHR are adequate to meet the visibility 

requirements for the first 

implementation period of the RHR. 

Thus, Arkansas’s use of presumptive 

limits should be approved because, like 

the RHR confirms, use of presumptive 

limits by Arkansas ensures that there is 

sufficient visibility improvement to 

satisfy the URP goals. The EPA’s 

suggestion that a more detailed or 

extensive investigation is required is not 

supported by the RHR or guidance. It is 

the state’s prerogative to make this 

determination and to choose what 

sources of information and degree of 

investigation is adequate. Having 

confirmed EPA’s expectations, the 

state’s submission should be approved. 

Response: Neither the 2004 proposed 

nor the final RHR provide that adoption 

of the presumptive emission limits 

identified in the RHR are all that is 

necessary to meet the visibility 

requirements for the first 

implementation period of the RHR. The 

EPA disagrees that the RHR confirms 

that use of presumptive limits by states 

ensures that there is sufficient visibility 

improvement to satisfy the URP goals. It 

appears that the comment may have 

been referring to the ‘‘national visibility 

goal,’’ or ‘‘reasonable progress goals,’’ 

(which are interim visibility goals 

towards meeting the national visibility 

goal), instead of the ‘‘URP goals.’’ The 

RHR states the following regarding the 

SO2 and NOX presumptive limits: 

‘‘Based on our analysis of emissions 

from power plants, we believe that 

applying these highly cost-effective 

controls at the large power plants 

covered by the guidelines would result 

in significant improvements in visibility 

and help to ensure reasonable progress 

toward the national visibility goal.’’ 64

A full reading of the RHR and the 

BART Rule, demonstrates that the 

proper interpretation of this statement is 

that because EPA found these controls 

to be generally highly cost-effective and 

would result in significant visibility 

improvement, EPA concluded that 

requiring affected sources to achieve at 

least this level of control would help 

ensure reasonable progress toward the 

national visibility goal. The RHR did not 

confirm that by adopting the 

presumptive emission limits states 

would ensure sufficient visibility 

improvement to satisfy their reasonable 

progress goals, since for the first 

implementation period this can only be 

confirmed by EPA’s full approval of the 

state’s RH SIP. Furthermore, for a state 

to achieve reasonable progress during 

the first implementation period, it must 

look at sources beyond those that are 

subject to BART as well as at non-point 

sources and determine, based on 

consideration of the four statutory 

factors at 40 CFR 51.308(d)(1)(i), 

whether it is reasonable to require these 

sources to install additional pollution 

controls. Therefore, even if states satisfy 

the BART requirements, satisfaction of 

the reasonable progress requirements 

can’t be met by complying with BART 

requirements alone. 

With regard to the comment that the 

RHR and BART Guidelines do not 

support EPA’s position that a more 

detailed or extensive investigation is 

required, EPA notes that in response to 

comments on the proposed BART 

Guidelines that the presumptive SO2

EGU limits should be more stringent, 

EPA justified its decision not to 

establish more stringent presumptive 

emission limits in the preamble to the 

final BART Rule by explaining that ‘‘[i]f, 

upon examination of an individual 

EGU, a State determines that a different 

emission limit is appropriate based 

upon its analysis of the five factors, then 

the State may apply a more or less 

stringent limit.’’ 65 Similar statements 

are made elsewhere in the BART Rule. 

Clearly, the RHR and the BART Rule do 

not suggest the presumptive limits 

should be viewed as establishing a safe 

harbor from more stringent regulation 

under the BART provisions. While 

states do have discretion in how to go 

about making BART determinations, 

states have a duty to evaluate the five 

statutory factors,66 and should consider 

the level of control that is currently 

achievable at the time the BART 

analysis is conducted.67

Comment: The EPA was incorrect in 

disapproving ADEQ’s SO2 and NOX

BART determinations that adopted the 

presumptive limit for subject to BART 

power plants greater than 750 MW. 

ADEQ used the presumptive limits 

provided by EPA in the BART Rule and 

worked with the affected facilities to 

make BART determinations. 

Response: The EPA disagrees. States 

have a duty to evaluate the five statutory 

factors,68 and should consider the level 

of control that is currently achievable at 

the time the BART analysis is 

conducted.69 As already explained in 

our response to similar comments in 

this final rulemaking, adoption of the 

presumptive emission limits for subject 

to BART EGUs greater than 750 MW, 

without a proper evaluation of the five 

statutory factors, is not sufficient to 

meet the BART requirements in the RHR 

and the BART Rule. 

Comment: The EPA incorrectly states 

that such BART-eligible sources should 

at least meet the presumptive limits. 

BART-eligible sources are just that— 

eligible. As such, these sources are not 

required to meet any limit until 

modeling indicates that the unit either 

causes or contributes to visibility 

impairment. The use of the phrase 

‘‘BART-eligible’’ in this context appears 

to be a mistaken reference to ‘‘subjectto-BART’’ sources. 

Response: The EPA agrees that we 

meant to say that ‘‘subject to BART 

sources’’ rather than ‘‘BART eligible 

sources’’ should at least meet the 

presumptive limits. This misstatement 

is minor and did not affect our 

evaluation of Arkansas’s RH SIP. 

B. Comments on Reasonable Progress 

Goals and Long Term Strategy 

Comment: The EPA’s proposed rule 

would disapprove Arkansas’s RPGs 

because in EPA’s view the State did not 

provide an analysis that considered the 

four statutory factors under 40 CFR 

51.308(d)(1)(i)(A) to evaluate the 

potential of controlling certain sources 

or source categories for addressing 

visibility impacts from man-made 

sources. Whether or not this is true, it 

does not appear that the state has fallen 

short of its obligations under the RHR 

and applicable EPA guidance. States 

generally must consider the reasonable 

progress factors and the URP in 

establishing RPGs. Arkansas clearly 

considered the URP and has 

demonstrated that the measures 

included in the SIP exceed those 

necessary to meet the URP for both of 

its Class I areas. As for the reasonable 

progress factors, the BART Guidelines 

note their substantial similarity to the 

BART factors (70 FR 39143), and EPA 

guidance makes clear that states need 

not reassess the reasonable progress 

factors for sources subject to BART for 

which the state has already completed 

a BART analysis. As such, EPA has not 


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70 64 FR 35731. 

71See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 2.4. 

72See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 5.0. 

73See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 1.2. 

74 64 FR 35766. 

identified a flaw in the state’s 

reasonable progress analysis warranting 

disapproval of Arkansas’s selected 

RPGs. EPA must respect the states’ 

considerable discretion in determining 

RPGs and cannot substitute its judgment 

for that of the state simply because EPA 

would have performed a different type 

of assessment if it had the authority to 

establish RPGs. The EPA does not have 

the authority to require the adoption of 

RPGs other than those found by the 

states to be reasonable and must defer 

to the state’s reasonable progress 

determinations. 

Response: The EPA disagrees that the 

Arkansas RH SIP has not fallen short of 

its obligations under the RHR and 

applicable EPA guidance. With respect 

to the RPG requirements, the State has 

fallen short of its obligations precisely 

because it did not provide an analysis 

that considered the four statutory 

factors, as required under 40 CFR 

51.308(d)(1)(i)(A). The RHR states the 

following with regard to RPG 

requirements: 

‘‘Today’s final rule requires the States to 

determine the rate of progress for remedying 

existing impairment that is reasonable, taking 

into consideration the statutory factors, and 

informed by input from all stakeholders.’’ 70

The EPA’s 2007 guidance for setting 

RPGs (referred to hereafter as EPA’s RPG 

Guidance) states the following with 

regard to the statutory factors under 40 

CFR 51.308(d)(1)(i)(A): 

‘‘The regional haze rule requires you to 

clearly support your RPG determination in 

your SIP submission based on the statutory 

factors.’’ 71

Therefore, it is clear that the Arkansas 

RH SIP has fallen short of its obligations 

with regard to RPG requirements under 

the RHR and applicable EPA guidance. 

The EPA agrees that states generally 

must consider the reasonable progress 

factors (i.e. the four statutory factors) 

under 40 CFR 51.308(d)(1)(i)(A) and the 

URP in establishing RPGs. The EPA also 

agrees that EPA guidance states that it 

is not necessary for states to reassess the 

reasonable progress factors for sources 

subject to BART for which the state has 

already completed a full five factor 

BART analysis.72 However, the 

requirement in the RHR and EPA’s RPG 

guidance for states to consider the four 

statutory factors applies to all point 

sources (and non-point sources if 

appropriate), and as such, is not limited 

only to sources that are subject to BART. 

In establishing RPGs, states must still 

consider the four statutory factors for 

sources that are not subject to BART. 

EPA’s guidance for establishing RPGs 

states the following: 

‘‘The discussion of the statutory factors in 

this guidance is largely aimed at helping 

States apply these factors in considering 

measures for point sources. States may find 

that the factors can be applied to sources 

other than point sources; the meaning of the 

factors, however, should not be unduly 

strained in order to fit non-point sources.’’ 73

As such, what warrants EPA’s 

disapproval of Arkansas’s RPGs is that 

in establishing its RPGs, the State did 

not evaluate the four statutory factors 

for sources that are not subject to BART, 

as required under 40 CFR 

51.308(d)(1)(i)(A). Arkansas’s lack of 

RPG analysis is especially troublesome 

in light of several sources not subject to 

BART which contribute to the 

impairment of visibility above 0.5 dv, as 

explained in more detail in our 

proposed rulemaking. To satisfy the 

RHR requirements, the State must do 

more than just consider the URP in 

establishing RPGs. As explained in our 

proposed rulemaking on the Arkansas 

RH SIP, the RHR provides that EPA will 

consider both the State’s consideration 

of the four factors in 40 CFR 

51.308(d)(1)(i)(A) and its analysis of the 

URP in determining whether the State’s 

goal for visibility improvement provides 

for reasonable progress.74 Therefore, the 

State must still consider the four 

statutory factors under 40 CFR 

51.308(d)(1)(i)(A), even if the CENRAP’s 

modeling demonstrated that the 

measures included in the SIP exceed 

those necessary to meet the URP for the 

first implementation period for both of 

Arkansas’s Class I areas. The RHR and 

EPA’s guidance for establishing RPGs do 

not provide that a State may forego an 

analysis of the four statutory factors if 

modeling demonstrates that it is 

expected to meet the URP in 2018 for 

both of its Class I areas. EPA agrees with 

the commenter that states have 

considerable discretion in determining 

RPGs. Nevertheless, there are several 

requirements that states must meet in 

establishing their RPGs, and where EPA 

determines that these requirements have 

not been satisfied, EPA has the authority 

to disapprove the State’s RPGs and 

indeed must disapprove it as not 

meeting the Federal requirements. 

In our disapproval of the State’s RPGs, 

EPA is not substituting its judgment for 

that of the State. Our disapproval is not 

based on a disagreement with the State 

with regard to the value of the State’s 

RPGs, rather our disapproval is based on 

the fact that the State did not evaluate 

the four statutory factors in establishing 

its RPGs, especially given that known 

sources of visibility impairment were 

not analyzed. We note that, at this point, 

it is not possible to know whether 

different RPGs are appropriate for 

Arkansas’s Class I areas. Until the State 

conducts a proper evaluation of the four 

statutory factors, in accordance with the 

CAA § 169A(g)(1), 40 CFR 

51.308(d)(1)(i)(A), and EPA’s RPG 

Guidance, or EPA conducts such 

evaluation in the context of a FIP, we 

will not know whether different RPGs 

are appropriate for Arkansas’s Class I 

areas. 

Comment: The EPA properly 

approved Arkansas’s URP, but 

improperly applied the URP when 

analyzing Arkansas’s BART 

determinations and RPGs. EPA 

acknowledges that the measures 

Arkansas adopted in the RH SIP would 

meet the URP, but EPA still partially 

disapproved the Arkansas RH SIP in 

part because ADEQ did not undertake 

any ‘‘further analysis’’ after determining 

its RPGs would meet or exceed the URP. 

EPA’s claim that Arkansas is required to 

undertake any further analysis lacks a 

legal basis, as states are not required to 

go beyond the URP analysis in 

establishing RPGs. Neither the CAA nor 

the RHR allow for the ‘‘further analysis’’ 

EPA is requiring of Arkansas regarding 

its RPGs and the URP. Courts have held 

that when an agency relies on factors 

which Congress has not intended it to 

consider, then such action is arbitrary 

and capricious (Arizona Public Service 

Company v. US EPA, 562 F.3d 1116, 

1123 (10th Cir. 2009)). The RHR 

explains that states must consider the 

uniform rate of improvement in 

visibility and the emissions reductions 

needed to achieve it when formulating 

RPGs, and since Arkansas has exceeded 

the URP when formulating its RPGs, 

Arkansas has met the legal requirements 

of the RHR. EPA should not have 

disapproved Arkansas’s RPGs since they 

are consistent with the CAA and the 

visibility impairment regulations. The 

EPA’s disapproval of Arkansas’s RPGs 

elevates form over substance, and fails 

to recognize the purpose of RPGs in 

improving visibility impairment. The 

RHR only requires additional analysis 

when a state establishes RPGs that 

provide for a slower rate of 

improvement than the URP (40 CFR 

51.308(d)(1)(ii). 

Response: The EPA disagrees that we 

improperly applied the URP when 


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14622 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

75 64 FR 35731. 76 76 FR 64195. 

77 40 CFR 51.308(d)(3). 

78 76 FR 64212. 

analyzing Arkansas’s BART 

determinations and RPGs. In fact, EPA 

did not consider the State’s URP in 

evaluating the State’s BART 

determinations because EPA does not 

have authority under the RHR to do so. 

With regard to the RPGs, EPA upholds 

its proposed disapproval of the State’s 

RPGs because the State did not 

undertake an analysis of the four 

statutory factors, as required under 40 

CFR 51.308(d)(1)(i)(A). While EPA 

agrees that the RHR requires states to 

consider the uniform rate of 

improvement in visibility when 

formulating RPGs, we disagree that a 

state’s consideration of the URP and 

establishment of RPGs that provide for 

a slightly greater rate of improvement in 

visibility than would be needed to attain 

the URP is all that is needed to satisfy 

the RPG requirements in the RHR. EPA 

also disagrees that the RHR only 

requires additional analysis when a 

state establishes RPGs that provide for a 

slower rate of improvement than the 

URP. As explained in our proposed 

rulemaking on the Arkansas RH SIP, in 

establishing its RPGs, the State is 

required by CAA § 169A(g)(1) and 40 

CFR 51.308(d)(1)(i)(A) to ‘‘[c]onsider the 

costs of compliance, the time necessary 

for compliance, the energy and non-air 

quality environmental impacts of 

compliance, and the remaining useful 

life of any potentially affected sources, 

and include a demonstration showing 

how these factors were taken into 

consideration in selecting the goal.’’ 

The RHR states the following with 

regard to RPG requirements: 

‘‘Today’s final rule requires the States to 

determine the rate of progress for remedying 

existing impairment that is reasonable, taking 

into consideration the statutory factors, and 

informed by input from all stakeholders.’’ 75

An analysis of the four statutory 

factors is precisely the ‘‘further 

analysis’’ EPA refers to in its proposed 

rulemaking on the Arkansas RH SIP.76

As explained above, both the RHR and 

the CAA require states to undertake this 

analysis in establishing its RPGs. 

Therefore, EPA disagrees that our 

proposed rulemaking on the Arkansas 

RH SIP is arbitrary and capricious 

because it relies on factors which 

Congress has not intended it to 

consider. CAA section 169A(g)(1) 

clearly requires states to consider these 

four factors in establishing their RPGs. 

Accordingly, EPA’s proposed 

disapproval of Arkansas’s RPGs is 

consistent with the RH regulations and 

the Act. Because the CAA section 

169A(g)(1) and 40 CFR 

51.308(d)(1)(i)(A) require that states 

consider the four statutory factors in 

establishing their RPGs, a requirement 

which Arkansas has not satisfied, our 

proposed disapproval of Arkansas’s 

RPGs recognizes the purpose of the 

RPGs in improving visibility 

impairment and is in keeping with the 

statutory requirements. 

Comment: We agree with EPA’s 

proposed disapproval of Arkansas’s 

RPGs because no proper four-factor 

analysis was done in setting those goals. 

In setting its RPGs, the state is required 

to consider the four statutory factors and 

include a demonstration showing how 

these factors were taken into 

consideration in selecting the goal (40 

CFR 51.308(d)(1)(i)(A) and 42 U.S.C. 

7491(g)(1)). As EPA stated in its 

proposed rulemaking, the RHR makes 

clear that just meeting the URP does not 

exempt a state from a proper four-factor 

evaluation of RPGs for the state’s Class 

I areas (see 76 FR 64195 and 64 FR 

35732). Being on the ‘‘glide path’’ to 

achieve the URP does not by itself 

ensure that a Class I area will make 

reasonable progress to reach natural 

background visibility conditions by 

2064 because the ‘‘glide path’’ assumes 

that increasing levels of reductions of 

visibility-impairing pollutants will 

consistently occur over the next 53 

years until 2064. There is no guarantee 

that this will happen, and ADEQ has not 

indicated what controls will be required 

in the next 53 years to ensure they stay 

on the glide path. EPA ensures that all 

reasonable measures that can be 

implemented during the first planning 

period are implemented by requiring 

states to evaluate whether additional 

progress beyond the URP is reasonable 

in this first RH planning period. 

Considering that the modeling on which 

future predictions of visibility 

impairment levels are based has 

uncertainties both in the modeling itself 

and in the projections of emissions for 

various source categories, it is necessary 

that states be required to conduct a fourfactor analysis to evaluate all the 

controls that could reasonably be 

implemented to make progress toward 

the national visibility goal. 

Response: The EPA agrees that 

Arkansas did not do a proper four-factor 

analysis nor did it include a 

demonstration showing how these 

factors were taken into consideration in 

selecting the goal in accordance with 

the CAA and the RHR. Please see 

elsewhere in our response to other 

comments for an explanation of the 

requirements for establishing RPGs. 

Comment: The EPA has proposed to 

partially disapprove Arkansas’s LTS for 

failure to include adequate emissions 

limitations as required under 40 CFR 

51.308(d)(3)(v)(C) due to the fact that 

the State relied on its BART emission 

limits to satisfy this LTS requirement 

and EPA is proposing to disapprove the 

majority of those BART emission limits 

(76 FR 64218). The EPA has proposed 

to approve the remaining elements of 

the Arkansas LTS. EPA should not 

partially approve any part of Arkansas’s 

LTS when EPA has proposed to 

disapprove Arkansas’s RPGs. A State’s 

LTS is the State’s plan to ensure that 

reasonable progress towards achieving 

natural background conditions is 

achieved both at the State’s Class I areas 

and at out-of-state Class I areas 

impacted by sources within the State 

(40 CFR 51.308(d)(3). If the State’s RPGs 

are not approvable, then no part of the 

State’s LTS should be approved because 

the purpose of the LTS is to reflect the 

State’s plan for assuring reasonable 

progress, which is in turn based on the 

State’s RPGs. The Arkansas LTS should 

be disapproved in its entirety. 

Response: While EPA agrees that a 

state’s LTS is its plan to ensure that 

reasonable progress towards achieving 

natural background conditions is 

achieved both at the state’s Class I areas 

and at out-of-state Class I areas 

impacted by sources within the state,77

EPA disagrees that no part of a state’s 

LTS should be approved even if the 

state’s RPGs are not approvable. As 

explained in our proposed rulemaking 

on the Arkansas RH SIP, the LTS is a 

compilation of state-specific control 

measures relied on by the states for 

achieving their RPGs.78 Regardless of 

what RPGs a state establishes (and 

whether or not EPA approves these 

RPGs), state-specific control measures 

will help the state make progress 

towards improving visibility. Even 

though these control measures may not 

ensure that a state’s RPGs will be met, 

especially in cases such as this where 

EPA is disapproving the State’s RPGs, 

the control measures that the State has 

relied on in the LTS for achieving its 

RPGs (with the exception of the BART 

determinations we are disapproving) 

will aid the State in achieving 

reasonable progress. 

Furthermore, 40 CFR 51.308(d)(3)(v) 

requires that states consider certain 

factors in developing their LTS. These 

LTS factors are: (A) Emission reductions 

due to ongoing air pollution control 

programs, including measures to 

address RAVI; (B) measures to mitigate 

the impacts of construction activities; 

(C) emissions limitations and schedules 

for compliance to achieve the 


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79 76 FR 64216. 

reasonable progress goal; (D) source 

retirement and replacement schedules; 

(E) smoke management techniques for 

agricultural and forestry management 

purposes including plans as currently 

exist within the state for these purposes; 

(F) enforceability of emissions 

limitations and control measures; and 

(G) the anticipated net effect on 

visibility due to projected changes in 

point, area, and mobile source 

emissions over the period addressed by 

the LTS. As explained in our proposed 

action on the Arkansas RH SIP, we are 

finding that Arkansas had appropriately 

considered these factors, with the 

exception of the factor under 40 CFR 

51.308(d)(3)(v)(C), which requires the 

State to consider emission limitations 

and schedules for compliance to achieve 

the RPGs. Therefore, with the exception 

of this element, we are finding that the 

LTS satisfies the requirements of 40 CFR 

51.308(d)(3). Furthermore, we point out 

that satisfaction of some of the 

requirements under 40 CFR 51.308(d)(3) 

is not intrinsically tied to or 

conditioned upon a specific dv value for 

the RPG. Therefore, disapproval of the 

RPGs does not mean automatic 

disapproval of all elements of the LTS. 

We are finalizing our proposed partial 

approval and partial disapproval of 

Arkansas’s LTS. 

Comment: According to EPA’s TSD 

for the Arkansas RH SIP, Arkansas Class 

I areas are impacted by sources from 

outside the State as well as by sources 

within the State. In 2018, Arkansas 

sources are projected to be the top 

contributor to visibility impairment at 

Caney Creek and Upper Buffalo. The 

contribution from Arkansas’s sources at 

the Class I areas in Arkansas, Missouri, 

Oklahoma, and other states is projected 

to increase in 2018 from 2002 levels. It 

appears that the projected improvement 

in visibility in 2018 for Caney Creek and 

Upper Buffalo is mainly due to 

significant projected emission 

reductions from sources in Texas. Even 

if other states are requiring emission 

reductions at the sources that cause and 

contribute to visibility impairment in 

Arkansas’s Class I areas, Arkansas still 

has an obligation under its LTS to adopt 

control measures adequate to address its 

contribution to visibility impairment in 

the State’s Class I areas. The Federal RH 

regulations require that ‘‘where other 

States cause or contribute to impairment 

in a mandatory Class I Federal area, the 

State must demonstrate that it has 

included in its implementation plan all 

measures necessary to obtain its share of 

the emissions reductions needed to 

meet the progress goal for the area’’ (see 

40 CFR 51.308(d)(3)(ii)). Therefore, as 

part of the LTS, Arkansas is required to 

identify all sources of visibility 

impairment in the State and should 

have considered the adoption of 

emission limitations and compliance 

schedules for those sources to achieve 

natural background visibility conditions 

at Arkansas’s Class I areas. Arkansas 

failed to properly evaluate these 

emission limitations and compliance 

schedules. 

Response: The EPA agrees that 

Arkansas Class I areas are impacted by 

sources from outside the State as well as 

by sources within the State, and that 

modeling demonstrates that Arkansas 

sources are projected to be the top 

contributor to visibility impairment at 

Caney Creek and Upper Buffalo in 2018. 

EPA also agrees that the contribution of 

Arkansas sources to visibility 

impairment at Class I areas in Arkansas, 

Missouri, Oklahoma, and other states is 

projected to increase in 2018 from 

baseline levels. 

Under 40 CFR 51.308(d)(3), states 

must submit a LTS that addresses 

visibility impairment for each Class I 

area within the State and for each Class 

I area located outside the State which 

may be affected by emissions from the 

State. Arkansas has done this, and we 

are partially approving and partially 

disapproving that LTS, as explained in 

more detail in our proposed rulemaking 

and discussed elsewhere in our 

response to other comments. Under 40 

CFR 51.308(d)(3)(i), states that are 

reasonably anticipated to contribute to 

visibility impairment in any Class I area 

located in another state are required to 

consult with the other state to develop 

coordinated emission management 

strategies. States are also required to 

consult with any other states that are 

reasonably anticipated to contribute to 

visibility impairment in any Class I area 

within the state. As explained in our 

proposed rulemaking, Arkansas satisfied 

this requirement through its 

consultation with affected states. Under 

40 CFR 51.308(d)(3)(ii), where other 

states cause or contribute to impairment 

in a Class I area, the State must 

demonstrate that it has included in its 

implementation plan all measures 

necessary to obtain its share of the 

emissions reductions needed to meet 

the progress goals for the area. States 

can meet this requirement through 

participation in a regional planning 

process where all potentially affected 

states are consulted, and by ensuring 

that they have included all measures 

needed to achieve their apportionment 

of emission reduction obligations agreed 

upon through that process. As explained 

in our proposed rulemaking on the 

Arkansas RH SIP, we are finding that 

Arkansas satisfied its consultation 

requirements when establishing its 

LTS.79 Therefore, EPA is finding that 

the Arkansas RH SIP satisfies the 

requirements under 40 CFR 

51.308(d)(3)(i) and (ii). 

The EPA agrees that as part of setting 

RPGs and developing a LTS, Arkansas is 

required to identify sources of visibility 

impairment in the State and to establish 

‘‘emission limitations, schedules of 

compliance and other measures as may 

be necessary to make reasonable 

progress toward the national goal.’’ In 

developing a RH SIP, the state 

accordingly must consider whether 

there are reasonable measures that 

should be adopted. A state is also 

required to consider the adoption of 

emission reduction measures needed to 

achieve the URP. The RHR does not 

require a state to consider what 

measures would be necessary to achieve 

natural background visibility conditions 

at Arkansas’s Class I areas. EPA does, 

however, agree that Arkansas failed to 

properly evaluate whether there were 

any reasonable measures beyond BART 

that could have been adopted to 

improve visibility. 

Comment: The fact that emissions of 

SO2, NOX, and other visibility impairing 

pollutants are projected to increase in 

2018 compared to 2002 levels, indicates 

that Arkansas is not doing all it can to 

address the sources of visibilityimpairment that exist in the State of 

Arkansas. There are additional control 

measures Arkansas should have 

considered for adoption as part of its 

LTS. For example, ADEQ’s BART 

emission limits for White Bluff Units 1 

and 2 and Flint Creek do not reflect the 

top levels of emissions control 

achievable at Arkansas’s subject to 

BART sources, nor do the emission 

limits reflect the capabilities of the 

control equipment that has been 

proposed to be installed. If not required 

to meet lower SO2 limits as BART, 

ADEQ should evaluate lower SO2 limits 

to ensure reasonable progress toward 

achieving natural background visibility 

conditions. Also, ADEQ did not 

evaluate installation of post-combustion 

controls such as SCR to meet the NOX

BART requirements for White Bluff 

Units 1 and 2 or Flint Creek Boiler No. 

1. The data on the worst 20% days for 

Caney Creek shows that nitrates are 

often the major component of visibility 

impairment during the winter months 

and the data on the best 20% days for 

Caney Creek shows that nitrates are 

more often the major component of 

visibility impairment. At Upper Buffalo, 

nitrates are the major component of 


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14624 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

80See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 4.2. 

81See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 5.0. 

82See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 5.0. 

visibility impairment in the winter 

months as well, and nitrates are also a 

major component of visibility 

impairment in the spring and fall 

months. The Missouri Class I areas 

show similar patterns. The 2018 

modeling projections show that nitrates 

continue to be a major component of 

visibility impairment during the winter 

months on the 20% worst days at Caney 

Creek. Therefore, if post-combustion 

controls are not required as BART for 

White Bluff Units 1 and 2 and Flint 

Creek Boiler No. 1, then the State 

should be required to evaluate 

installation of post-combustion controls 

at these sources to meet reasonable 

progress requirements. If not ultimately 

required to meet lower SO2 limits or the 

installation of SCR as BART, the State 

should evaluate lower limits and 

additional controls on SO2 and NOX to 

ensure reasonable progress is made 

toward natural background visibility 

conditions. 

Response: The EPA agrees that 

emissions of visibility impairing 

pollutants in Arkansas are projected to 

increase in 2018 from baseline levels, 

and that in establishing its RPGs and 

LTS, the State has not appropriately 

considered whether there are additional 

measures that would be reasonable for 

addressing visibility impairment. That 

emissions of SO2, NOX, and other 

visibility impairing pollutants in 

Arkansas are projected to increase 

suggests that the state should carefully 

consider what measures can be adopted 

to ensure that the state contributes to 

improving visibility in the region. EPA 

also agrees that Arkansas’s NOX and SO2

BART emission limits for White Bluff 

Units 1 and 2 and Flint Creek Boiler No. 

1 do not reflect the most stringent level 

of emissions control achievable at 

Arkansas’s subject to BART sources. As 

explained in our proposed rulemaking 

on the Arkansas RH SIP, we are 

disapproving the State’s SO2 and NOX

BART determinations for White Bluff 

Units 1 and 2 and Flint Creek Boiler No. 

1 because Arkansas limited its BART 

determinations to considering the 

measures necessary for achieving the 

presumptive limits and did not 

appropriately consider whether more 

stringent controls or emission limits 

were appropriate based on a 

consideration of the five statutory 

factors, as required by 40 CFR 

51.308(e)(1)(ii)(A) and section 

169A(g)(2) of the CAA. However, EPA 

disagrees that if we ultimately approve 

BART determinations that do not 

require White Bluff Units 1 and 2 and 

Flint Creek Boiler No. 1 to install postcombustion controls and/or do not 

require these sources to establish SO2

and NOX BART emission limits more 

stringent than those currently adopted 

by the State, Arkansas is required to 

evaluate post-combustion controls and 

more stringent SO2 and NOX limits for 

its subject to BART sources to satisfy the 

reasonable progress requirements at 40 

CFR 51.308(d)(1). Because the BART 

analysis that is required for subject to 

BART sources is based, in part, on an 

assessment of many of the same factors 

that must be addressed in establishing a 

state’s RPGs, EPA’s guidance for 

establishing RPGs provided that it is 

reasonable for a State to conclude that 

any control requirements imposed in 

the BART determination also satisfy the 

RPG-related requirements for source 

review in the first RPG planning 

period.80 EPA’s guidance states the 

following: 

‘‘Also, as noted in section 4.2, it is not 

necessary for you to reassess the reasonable 

progress factors for sources subject to BART 

for which you have already completed a 

BART analysis.’’ 81

Therefore, we note that once EPA has 

approved the BART determination for a 

particular pollutant for a given subject 

to BART source, the State is not 

required to evaluate the reasonable 

progress factors for that particular 

pollutant for the given source in order 

to satisfy the reasonable progress 

requirements. 

Comment: There are additional 

control measures Arkansas should have 

considered for adoption as part of its 

LTS. Arkansas must consider controls 

for other point sources in the State that 

are not subject to BART but that could 

be required to reduce emission to help 

Arkansas and other affected states 

assure reasonable progress towards 

achieving background visibility 

conditions. For example, Arkansas 

should evaluate controls for Entergy’s 

Independence Power Plant, which is 

located approximately 140 km from 

Upper Buffalo, and is the second largest 

source of SO2 and NOX emissions in 

Arkansas (Entergy White Bluff is the 

first). Once the White Bluff power plant 

installs controls to meet BART for SO2

and NOX, the Independence plant will 

be the largest source of SO2 and NOX in 

the State. The Independence plant was 

not identified by ADEQ as BARTeligible. It consists of two coal-fired 

units that have no SO2 control 

technology installed with a generating 

capacity of 1700 MW (see Exhibit 23). 

PM emissions are controlled with 

electrostatic precipitators (ESPs) and 

NOX emissions are controlled only with 

overfire air. Despite its size and 

location, the Arkansas RH SIP did not 

identify the Independence plant as a 

possible source of visibility impairment. 

Upgraded combustion controls and/or 

installation of SCR should be evaluated 

for control of NOX emissions, and the 

installation of a scrubber should be 

evaluated for control of SO2 emissions. 

Arkansas should be required to evaluate 

these as well as additional control 

measures to ensure it is doing all it can 

to provide for reasonable progress 

toward meeting natural visibility 

conditions at the State’s Class I areas 

and at the Class I areas impacted by 

Arkansas sources. 

Response: EPA agrees that Arkansas 

must consider controls for point sources 

in the State that are not subject to BART 

but that could be required to reduce 

emissions to help Arkansas and other 

affected states assure reasonable 

progress towards achieving background 

visibility conditions. We do note that 

the RHR and EPA’s guidance for 

establishing RPGs give states flexibility 

in determining which particular sources 

to evaluate and how to take into 

consideration the four statutory factors. 

EPA’s guidance for establishing RPGs 

provide the following: 

‘‘In determining reasonable progress, CAA 

§ 169A(g)(1) requires States to take into 

consideration a number of factors. However, 

you have flexibility in how to take into 

consideration these statutory factors and any 

other factors that you have determined to be 

relevant. For example, the factors could be 

used to select which sources or activities 

should or should not be regulated, or they 

could be used to determine the level or 

stringency of control, if any, for selected 

sources or activities, or some combination of 

both.’’ 82

As the Entergy Independence Power 

Plant has significant emissions and 

emissions reductions from the source 

would likely help Arkansas and other 

affected states assure reasonable 

progress, EPA agrees that the Entergy 

Independence Power Plant is a good 

candidate for further consideration by 

Arkansas. As we are disapproving 

Arkansas’s RPGs, the State will need to 

consider whether controls at this facility 

and any other facilities would be 

reasonable for purposes of addressing 

visibility impairment. 

Comment: In addition to Caney Creek 

and Upper Buffalo, sources in Arkansas 

also contribute to visibility impairment 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14625 

83Chuck McDate and Warren White UC Davis, 

Power Point from Inter-RPO Data Analysis/ 

Monitoring Workgroup 9/28/05 ‘‘Approach for 

Substituting Mingo IMPROVE Carbon Data’’, RPO 

Call 092805 Mingo.ppt; Archuleta, et al. Extended 

Abstract #58 ‘‘IMPROVE Data Substitution Methods 

for Regional Haze’’, 58-Archuleta.pdf; Graphic of 

comparison of two technique results, Out.pdf; 

Communications record between Scott Copeland 

CIRA—Cooperative Institute for Research in the 

Atmosphere with Erik Snyder, EPA Region 6, 

February 10, 2012. 

84See letter from Mike Bates, Air Division 

Director, Arkansas Department of Environmental 

Quality, to Eddie Terrill, Air Division Director, 

Oklahoma Department of Environmental Quality, 

dated August 17, 2007. This letter is found in 

Appendix 10.3 of the Arkansas RH SIP. 

in Missouri’s two Class I areas (Mingo 

and Hercules Glades) and Oklahoma’s 

Class I area (Wichita Mountains). Even 

though Arkansas claims it does not need 

to adopt any additional measures in its 

LTS because the CENRAP 2018 

modeling showed that the emissions 

reductions planned in CENRAP states 

were sufficient for Missouri’s Class I 

areas to meet their RPGs, EPA has not 

proposed action on the Missouri RH 

SIP, and it is not clear if EPA will be 

approving Missouri’s RPGs. Also, the 

CENRAP 2018 modeling Missouri relied 

on may be underestimating impacts due 

to sulfates, as indicated by EPA in 

Appendix A to the TSD for the Arkansas 

RH SIP. For the Mingo Class I area in 

Missouri, since there was not sufficient 

capture of valid IMPROVE data to 

determine baseline conditions in 

accordance with EPA guidance, it is not 

clear whether the CENRAP modeling 

shows that the projected visibility 

improvements at Mingo will meet or 

exceed the URP toward attaining 

background visibility conditions. 

Therefore, Arkansas cannot rely on 

Missouri’s claims that it is meeting its 

RPGs to justify avoiding the evaluation 

of additional control measures for 

sources of visibility-impairing 

pollutants in Arkansas. In addition, 

Arkansas sources contributed 2.0% to 

visibility impairment at Wichita 

Mountains during the baseline period 

and are projected to contribute 2.3% in 

2018. This may appear to be a small 

contribution, but it is a contribution 

nonetheless. Oklahoma apparently does 

not agree with ADEQ that Arkansas’s 

source contributions are insignificant. 

Since the Wichita Mountains is not 

expected to achieve the necessary 

improvements in visibility in 2018 to 

meet or exceed the URP, Arkansas 

should be required to evaluate emission 

controls that could be required at 

Arkansas sources that impact visibility 

at the Wichita Mountains. Arkansas has 

an obligation as part of its LTS to 

evaluate and adopt those control 

measures necessary to address 

Arkansas’s share of visibility 

impairment in Class I areas in Missouri 

and Oklahoma (40 CFR 51.308(d)(3)(ii)). 

Response: We disagree that because 

EPA has not proposed action on the 

Missouri RH SIP, we cannot find that 

Arkansas does not need to adopt any 

additional measures in its LTS. We find 

that we have the authority to act on 

Arkansas’s LTS now. 

In the context of acting on the LTS 

and Arkansas’s RH SIP, the comment 

raises a concern with missing data at the 

Mingo Wilderness Area’s IMPROVE 

monitor, and refers to a statement in the 

CENRAP TSD that because of a lack of 

data it did not meet EPA’s data 

acceptance criteria. The Mingo monitor 

had a wasp type nest inside the 

collection apparatus for the Organic 

Carbon sampling stream that may have 

impacted the air flow and sampling for 

these specific pollutants, but not the 

other sampling streams. The other 

pollutants, including nitrates and 

sulfates (NOX and SO2 products) were 

collected for the entire baseline time 

period without the need for data 

substitution. The IMPROVE group did 

evaluate two different approaches to 

backfill the missing data for the organics 

and Elemental Carbon that resulted in 

nearly identical results. They then 

selected the method that they thought 

was most appropriate in backfilling the 

data based on other monitoring data 

collected. This backfill data was then 

used with the rest of the monitored data 

for the baseline for the Mingo monitor. 

The IMPROVE group is made up of a 

number of experts in these specific 

issues and we concur that the approach 

is acceptable for use in establishing the 

baseline. It is very important to note that 

the Organic Carbon is a significantly 

smaller component of the visibility 

impairment than the amount of 

impairment from ammonium nitrate and 

ammonium sulfate at Mingo. We do not 

believe any inaccuracies in the backfill 

information for organic carbon would 

significantly impact the baseline at 

Mingo.83

With regard to the establishment of a 

state’s LTS, 40 CFR 51.308(d)(3)(i) states 

the following: 

‘‘Where the State has emissions that are 

reasonably anticipated to contribute to 

visibility impairment in any mandatory Class 

I area located in another State or States, the 

State must consult with the other State(s) in 

order to develop coordinated emission 

management strategies.’’ 

As explained in our proposed 

rulemaking on the Arkansas RH SIP, 

CENRAP’s photochemical modeling 

demonstrated that besides Arkansas’s 

own Class I areas, the only Class I areas 

where Arkansas sources can be said to 

be contributing to visibility impairment 

are the Mingo Wilderness Area and the 

Hercules Glades Wilderness Area in 

Missouri and not Wichita Mountains in 

Oklahoma. Arkansas considered 

modeling that was performed by the 

CENRAP and consulted with Missouri, 

Oklahoma, and other potentially 

affected states. In its consultation with 

Missouri, both Arkansas and Missouri 

determined that it was not necessary for 

Arkansas to commit to additional 

emission reductions since the CENRAP 

modeling showed that emission 

reductions already planned by the 

CENRAP and other states would be 

sufficient for Missouri’s Class I areas to 

meet their RPGs (notwithstanding the 

uncertainties that may have been 

involved in the modeling). We note that 

Arkansas will be considering whether 

additional emission reduction measures 

are reasonable for improving visibility at 

the Class I areas within Arkansas and 

revisiting several of its BART 

determinations. Any more stringent 

measures adopted by Arkansas to 

address the deficiencies we have 

identified in its RH SIP have the 

potential to also benefit visibility at 

Mingo and Hercules Glades. When we 

take action on the Missouri RH SIP, we 

will consider whether Missouri’s RPGs 

are appropriate. 

With regard to the comment that 

Arkansas sources contributed 2.0% to 

visibility impairment at Wichita 

Mountains during the baseline period 

and are projected to contribute 2.3% in 

2018, EPA notes that removal of this 

2.3% contribution to the total extinction 

results in a visibility improvement of 

only 0.2 dv from the 2018 projected 

visibility conditions. Although the 

Oklahoma Department of Environmental 

Quality (ODEQ) initially believed that 

emissions from Arkansas sources are 

impacting visibility at Wichita 

Mountains and that it might be 

necessary for Arkansas to commit to 

additional emissions reductions, 

Arkansas responded to ODEQ’s 

concerns with a letter dated August 17, 

2007, explaining that based on 

photochemical modeling, ADEQ had 

calculated that the total visibility impact 

from all sources in Arkansas at Wichita 

Mountains is 0.2dv.84 Furthermore, in 

section X.A. of the Oklahoma RH SIP 

submitted to EPA, ODEQ references the 

August 17, 2007 letter sent by ADEQ 

and states that it is in agreement with 

the projected emissions reductions from 

Arkansas and all other states with 

which it consulted with regard to 

visibility impairment at Wichita 

Mountains. 


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14626 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

85See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 5.0. 

86See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 4.2. 

87See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 4.1. 88 40 CFR 51.308(d)(1)(i)(A). 

Consequently, while we are 

concerned that the RPG at Wichita 

Mountains is not on the glide path, we 

believe the technical assessment that 

Arkansas sources do not have a 

significant impact at Wichita Mountains 

is accurate and ADEQ and ODEQ 

followed consultation procedures. We 

therefore disagree that Arkansas must 

adopt additional control measures to 

address its visibility impact at other 

states’ Class I areas. Considering the 

modeling results and since both states 

agreed to this on the results of the 

consultations, we find that Arkansas has 

satisfied its obligations under 40 CFR 

51.308(d)(3)(i) and (ii). 

Comment: The EPA criticizes 

Arkansas for not conducting the four 

factor RPG analysis. However, EPA’s 

guidance only requires a four factor 

analysis for potentially affected sources. 

Because Arkansas determined that 

emission reductions anticipated from 

implementation of BART and other 

CAA programs during the initial 

planning period are sufficient to satisfy 

the URP, it is not required to consider 

additional emission reductions from 

other potentially affected sources in 

setting its RPGs. This approach is 

supported by EPA’s RPG Guidance, 

which opines that only BART and other 

existing CAA programs may be all that 

are necessary to achieve reasonable 

progress in the first planning period for 

some states. The EPA is incorrect that 

ADEQ relied solely on meeting the URP 

to reach its RPG determination. ADEQ 

relied on EPA guidance indicating the 

application of BART alone could be 

considered as constituting reasonable 

progress for the first planning period. 

Arkansas determined its URP. Arkansas 

participated in CENRAP, coordinated 

with Missouri Department of Natural 

Resources, and consulted with other 

states who may contribute to RH in 

Arkansas Class I areas. ADEQ also used 

modeling projections that show that the 

combination of already mandated 

controls, including BART emissions 

limitations, will provide for a rate of 

progress that improves visibility 

conditions and results in the attainment 

of natural visibility conditions by 2064. 

This modeling also demonstrated that 

the RPGs for Arkansas’s Class I areas are 

better than the URP. This is consistent 

with the requirements of the CAA and 

EPA’s regulations and guidance. Thus, 

Arkansas’s RPGs should be approved by 

EPA. 

Response: With regard to the 

comment that EPA’s guidance only 

requires a four factor analysis for 

potentially affected sources, we note 

that EPA’s RPG Guidance states the 

following: 

‘‘In determining reasonable progress, CAA 

§ 169A(g)(1) requires States to take into 

consideration a number of factors. However, 

you have flexibility in how to take into 

consideration these statutory factors and any 

other factors that you have determined to be 

relevant. For example, the factors could be 

used to select which sources or activities 

should or should not be regulated, or they 

could be used to determine the level or 

stringency of control, if any, for selected 

sources or activities, or some combination of 

both.’’ 85

EPA’s guidance for setting RPGs also 

provides that: 

‘‘The RHR gives States wide latitude to 

determine additional control requirements, 

and there are many ways to approach 

identifying additional reasonable measures; 

however, you must at a minimum, consider 

the four statutory factors. Based on the 

contribution from certain source categories 

and the magnitude of their emissions you 

may determine that little additional analysis 

is required to determine further controls are 

not warranted for that category.’’ 86

Although the State has flexibility in 

how to consider the four statutory 

factors, it must consider these four 

factors in some form. The State made no 

attempt to do this in the Arkansas RH 

SIP. Even if emission reductions 

anticipated from implementation of 

BART and other CAA programs during 

the initial planning period are expected 

to result in a slightly greater rate of 

improvement in visibility than would be 

needed to attain the URP for the first 

implementation period, the State must 

still consider whether any additional 

control measures would be reasonable, 

based on its consideration of the 

relevant factors. Arkansas’s actions are 

especially problematic as there are 

sources that are not subject to BART but 

which contribute to visibility 

impairment above the State’s 

established BART threshold of 0.5 dv. 

While EPA agrees that EPA’s RPG 

Guidance states that BART and other 

existing CAA programs may be all that 

is necessary to achieve reasonable 

progress in the first planning period for 

some states, Arkansas’s approach is not 

supported by our RPG Guidance.87

EPA’s guidance states that BART and 

other existing CAA programs may be all 

that is necessary, not that it is in fact all 

that is necessary. If the State believes 

that it is not necessary to require any 

sources to install controls under the 

reasonable progress requirements (i.e. 

that there are no ‘‘potentially affected 

sources’’), it must demonstrate this 

through its consideration of the four 

statutory factors. 

As discussed in our proposed 

rulemaking on the Arkansas RH SIP, we 

agree that the State properly determined 

its URP, and that the State participated 

in CENRAP and coordinated and 

consulted with other states who may be 

contributing to visibility impairment in 

Arkansas’s Class I areas. We find that 

Arkansas satisfies these requirements 

under the RHR. However, that is not all 

that a state is required to do in 

establishing its RPGs. In establishing its 

RPGs for any Class I area, a state must 

‘‘consider the costs of compliance, the 

time necessary for compliance, the 

energy and non-air quality 

environmental impacts of compliance, 

and the remaining useful life of any 

potentially affected sources, and include 

a demonstration showing how these 

factors were taken into consideration in 

selecting the goal.’’ 88 The Arkansas RH 

SIP does not satisfy this requirement. 

With regard to the comment that 

modeling projections show that the 

combination of already mandated 

controls will provide for a rate of 

progress that improves visibility 

conditions and result in the attainment 

of natural visibility conditions by 2064, 

EPA notes that the CENRAP modeled 

the projected visibility conditions 

anticipated at each Class I area in 2018. 

The CENRAP modeling is based on 

emissions reductions expected to result 

from Federal, State, and local control 

programs that are either currently in 

effect or with mandated future-year 

emission reduction schedules that 

predate 2018. The CENRAP modeling 

itself did not show that already 

mandated controls are expected to attain 

natural visibility conditions by 2064. 

Rather, the rate of visibility 

improvement anticipated by the 

CENRAP modeling in 2018, if sustained, 

would result in a return to natural 

visibility conditions prior to 2064. 

Therefore the comment that Arkansas is 

expected to ultimately achieve the 

national goal prior to 2064 assumes that 

the same level of reductions of 

visibility-impairing pollutants that is 

expected to occur during the first 

implementation period ending in 2018 

will increasingly occur during each 

implementation period until the final 

implementation period ending in 2064. 

However, there is no guarantee that this 

will occur. The Arkansas RH SIP 

addresses the requirements of the RHR 

only for the first implementation period 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14627 

89CAA section 169A(b)(2)(B). 

90 40 CFR 51.308(d)(3). 91 40 CFR 51.308(d)(3)(v). 

ending in 2018. As such, EPA disagrees 

that we should approve Arkansas’s 

RPGs because modeling demonstrates 

that Arkansas is expected to achieve the 

national goal prior to 2064. 

Comment: The EPA should not have 

disapproved Arkansas’s LTS since it is 

consistent with the CAA and the 

visibility impairment regulations. The 

EPA is proposing to disapprove 

Arkansas’s LTS because Arkansas relied 

on the emissions reductions and 

schedules of compliance associated 

with Arkansas’s BART determinations. 

The EPA’s reliance on its disapproval of 

Arkansas’s BART determinations as a 

basis for disapproving the LTS treads on 

the state’s authority under the CAA. The 

EPA’s disapproval of Arkansas’s LTS 

elevates form over substance, disregards 

the underlying purpose of the visibility 

protection program, and does not 

recognize the purpose of the LTS. 

Arkansas’s LTS complies with the CAA. 

The applicable regulations require each 

state to submit a long-term, 10- to 15- 

year strategy for making reasonable 

progress toward the national goal of 

natural visibility conditions in 2064. 

Given that Arkansas’s LTS includes 

emission limits, compliance schedules 

and other measures necessary to achieve 

reasonable progress toward the national 

visibility goal and to ultimately achieve 

natural visibility prior to 2064, the 

EPA’s proposed disapproval is baseless 

and further shows that EPA is acting 

beyond the scope of the visibility 

protection requirements of the CAA. 

Response: We disagree that 

Arkansas’s LTS fully satisfies the 

requirements of the CAA and the RH 

regulations. With regard to the LTS, the 

CAA requires that states establish: 

‘‘[A] long-term (ten to fifteen years) strategy 

for making reasonable progress toward 

meeting the national goal specified in 

subsection (a) of this section.’’ 89

Consistent with the requirement of 

the CAA, 40 CFR 51.308(d)(3) requires 

that states include in their RH SIPs a 

LTS that includes ‘‘enforceable 

emissions limitations, compliance 

schedules, and other measures as 

necessary to achieve the reasonable 

progress goals’’ for all Class I areas 

within, or affected by emissions from, 

the state.90 At a minimum, states must 

describe how each of the following 

seven factors listed below are taken into 

account in developing their LTS: (1) 

Emission reductions due to ongoing air 

pollution control programs, including 

measures to address RAVI; (2) measures 

to mitigate the impacts of construction 

activities; (3) emissions limitations and 

schedules for compliance to achieve the 

RPG; (4) source retirement and 

replacement schedules; (5) smoke 

management techniques for agricultural 

and forestry management purposes 

including plans as currently exist 

within the state for these purposes; (6) 

enforceability of emissions limitations 

and control measures; and (7) the 

anticipated net effect on visibility due to 

projected changes in point, area, and 

mobile source emissions over the period 

addressed by the LTS.91 Since 40 CFR 

51.308(d)(3)(v)(C) requires that in 

developing its LTS, Arkansas consider 

emissions limitations and schedules of 

compliance to achieve the RPGs, the 

State included the BART emission 

limits it established for its subject to 

BART sources as part of its LTS. As 

explained in our proposed rulemaking 

on the Arkansas RH SIP, the BART 

emission limits established by Arkansas 

are an element of the LTS, and because 

we are disapproving a portion of 

Arkansas’s BART determinations, it 

follows that the State did not properly 

consider emission limitations and 

schedules for compliance to include in 

its LTS, as required under 40 CFR 

51.308(d)(3)(v)(C). Therefore, we cannot 

approve this element of the LTS. 

Furthermore, as pointed out in one of 

the comments we received, since 

Arkansas did not consider the four 

statutory factors under 40 CFR 

51.308(d)(1)(i)(A) when establishing its 

RPGs, it is not possible to know at this 

point whether requiring additional 

controls for Arkansas source categories 

affecting visibility constitutes 

reasonable progress. Therefore, we find 

that Arkansas’s LTS does not include 

those measures necessary to achieve 

reasonable progress toward the national 

visibility goal. This is in support of the 

finding that Arkansas has not properly 

considered emission limitations and 

schedules for compliance in 

establishing its LTS, as required under 

40 CFR 51.308(d)(3)(v)(C). 

We acknowledge that the CENRAP 

modeling shows that with the measures 

included in the RH SIP, Arkansas is 

projected to meet the URP for the first 

implementation period ending in 2018 

for both of its Class I areas. However, 

with regard to the comment that 

Arkansas’s LTS includes those measures 

necessary to ultimately achieve natural 

visibility prior to 2064, we note that the 

Arkansas’s RH SIP (including the LTS) 

addresses the RHR requirements only 

for the first implementation period 

ending in 2018. The CENRAP modeling 

is based on emissions reductions 

expected to result from Federal, State, 

and local control programs that are 

either currently in effect or with 

mandated future-year emission 

reduction schedules that predate 2018. 

The CENRAP modeling itself did not 

show that already mandated controls are 

expected to attain natural visibility 

conditions by 2064. Rather, the rate of 

visibility improvement anticipated by 

the CENRAP modeling in 2018, if 

sustained, will result in a return to 

natural visibility prior to 2064. This 

assumes that the same level of 

reductions of visibility-impairing 

pollutants that is expected to occur 

during the first implementation period 

ending in 2018 will increasingly occur 

during each implementation period 

until the final implementation period 

ending in 2064. However, there is no 

guarantee that this will in fact occur. 

Comment: We agree with EPA’s 

findings that ADEQ cannot rely solely 

on meeting the uniform rate of progress 

to conclude that its goals provide for 

reasonable progress. ADEQ needs to 

consider the four statutory factors 

required under 40 CFR 

51.308(d)(1)(i)(A) to evaluate the 

potential controls for sources or source 

categories that contribute to visibility 

impairment. 

Response: As explained in our 

proposed rulemaking and elsewhere in 

our response to comments, Arkansas’s 

lack of consideration of the four 

statutory factors required under the RHR 

is the grounds for our disapproval of 

Arkansas’s RPGs. 

Comment: The EPA should 

disapprove Arkansas’s LTS as well as 

the reasonable progress analysis because 

Arkansas’s point sources emissions of 

SO2, the major pollutant contributing to 

visibility impairment in Arkansas’s 

Class I area, are projected to increase 

instead of decreasing between 2002 and 

2018. Source apportionment modeling 

by the CENRAP indicates that 

Arkansas’s contribution to sulfate in 

Class I areas is projected to increase as 

contributions from surrounding states 

are projected to decrease. This is in 

contradiction to 40 CFR 51.308(d)(3)(ii) 

which requires that the State 

demonstrate that it has included in its 

implementation plan all measures 

necessary to obtain its share of the 

emissions reductions needed to meet 

the progress goal for the area. 

Response: We agree that Arkansas’s 

point source SO2 emissions are 

projected to increase instead of 

decreasing between 2002 and 2018, and 

that the CENRAP modeling indicates 

that Arkansas’s contribution to sulfate 

in class I areas is projected to increase 

as contributions from surrounding states 


pmangrum on DSK3VPTVN1PROD with RULES_2
14628 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

92 40 CFR 51.308(d)(3)(ii). 

93 76 FR 64216. 

94See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 2.4. 

95CAA section 169A(g)(1). 

96 64 FR 35731. 

97 64 FR 35731. 

98 64 FR 35734. 

99See EPA’s Guidance for Setting Reasonable 

Progress Goals Under the Regional Haze Program 

(June 1, 2007), Section 1.2. 

are projected to decrease. However, we 

disagree that this is in contradiction 

with our proposed finding that the 

Arkansas RH SIP satisfies the 

requirements of 40 CFR 51.308(d)(3)(ii). 

The full reference to 40 CFR 

51.308(d)(3)(ii) is the following: 

‘‘Where other States cause or contribute to 

impairment in a mandatory Class I Federal 

area, the State must demonstrate that it has 

included in its implementation plan all 

measures necessary to obtain its share of the 

emissions reductions needed to meet the 

progress goals for the area. If the State has 

participated in a regional planning process, 

the State must ensure that it has included all 

measures needed to achieve its 

apportionment of emission reduction 

obligations agreed upon through that 

process.’’ 92

A state can meet the requirements 

under 40 CFR 51.308(d)(3)(ii) if when 

establishing its LTS, the state can 

demonstrate that it has included in its 

RH SIP all measures necessary to obtain 

its share of the emissions reductions 

needed to meet the progress goals. This 

means that if a state participates in a 

regional planning process, the state 

must ensure that the RH SIP includes all 

agreed upon measures needed to 

achieve its apportionment of emission 

reduction obligations. Arkansas met part 

of this requirement by participating in a 

regional planning process and 

consulting with other states that cause 

or contribute to impairment at 

Arkansas’s Class I areas, with the 

participating states arriving at a 

consensus with regard to each states’ 

apportionment of emissions reduction 

obligations. Arkansas’s RH SIP includes 

the regional planning process but those 

emission reductions agreed to by all 

states in the consultation meetings will 

not be met by Arkansas because the 

reductions from the BART 

determinations we are disapproving will 

not be realized. This is consistent with 

40 CFR 51.308(d)(3)(ii). As explained in 

our proposed rulemaking on the 

Arkansas RH SIP, we are finding that 

Arkansas satisfied its consultation 

requirements when establishing its 

LTS.93

Comment: The EPA’s proposed 

disapproval of Arkansas’s RPGs is not 

consistent with its own guidance, treads 

on the State’s authority under the CAA, 

and disregards the underlying purpose 

of the visibility protection program by 

criticizing the technical aspect of 

Arkansas’s evaluation even though EPA 

acknowledges that Arkansas’s SIP 

provides for a rate of visibility 

improvement that achieves the national 

goal before the time contemplated by 

the program itself. 

Response: The EPA disagrees that 

EPA’s disapproval of Arkansas’s RPGs is 

not consistent with its own guidance. 

EPA’s RPG Guidance states the 

following with regard to the statutory 

factors under 40 CFR 51.308(d)(1)(i)(A): 

‘‘The regional haze rule requires you to 

clearly support your RPG determination in 

your SIP submission based on the statutory 

factors.’’ 94

As explained in more detail elsewhere 

in our response to comments, even if 

emission reductions anticipated from 

implementation of BART and other 

CAA programs during the initial 

planning period would result in a 

slightly greater rate of improvement in 

visibility than would be needed to attain 

the URP, the State must still consider 

the four statutory factors in setting its 

RPGs. 

EPA also disagrees with the 

commenter’s statement that EPA’s 

proposed disapproval of Arkansas’s 

RPGs treads on the state’s authority 

under the CAA. The CAA requires that 

in determining reasonable progress, 

states should take into consideration the 

costs of compliance, the time necessary 

for compliance, and the energy and nonair quality environmental impacts of 

compliance, and the remaining useful 

life of any existing source subject to 

such requirements.95 Since the State has 

not taken into consideration these four 

factors, EPA’s disapproval of Arkansas’s 

RPGs is in accordance with the CAA. 

While we do recognize that the 

CENRAP’s modeling demonstrates that 

Arkansas is projected to meet the URP 

for the first implementation period 

ending in 2018 for both of its Class I 

areas, we emphasize that we cannot 

approve Arkansas’s RPGs because in 

setting its RPGs the State did not satisfy 

the requirements of the CAA 

§ 169A(g)(1), the RHR,96 and 40 CFR 

51.308(d)(1)(i)(A). 

Comment: With respect to 

establishment of RPGs, EPA has 

provided that the BART Rule does not 

require a definitive dv or percent 

improvement in visibility. All the BART 

Rule requires for each state is a 

demonstration of improvement of 

visibility. To that end, ADEQ did show 

in its RH SIP that there was a 

statistically significant improvement to 

visibility in the Class I areas modeled 

using the presumptive limits through 

statistical analysis and photochemical 

modeling. 

Response: It appears that the 

comment may have been referring to the 

RHR rather than the BART Rule, as it is 

the RHR that establishes the RPG 

requirements. While EPA agrees that the 

RHR does not require a definitive dv or 

percent improvement in visibility with 

respect to the establishment of RPGs,97

we disagree that all the RHR requires in 

terms of RPGs is a demonstration of 

visibility improvement. The RHR 

requires that the RPGs provide for an 

improvement in visibility for the most 

impaired days over the period of the 

implementation plan and ensure no 

degradation in visibility for the least 

impaired days over the same period.98

However, the RHR also establishes other 

analytical requirements states must 

satisfy in establishing their RPGs. 

Among these, is the requirement for 

states to consider the four statutory 

factors under 40 CFR 51.308(d)(1)(i)(A), 

which is a requirement that Arkansas 

has not satisfied. 

Comment: The ADEQ acted 

consistently with the EPA’s RPG 

Guidance when it did not perform a 

four-factor analysis in establishing 

Arkansas’s RPGs. The RPG Guidance 

provides that if common sense dictates 

that a particular statutory factor cannot 

be applied to a particular source 

category (i.e. non-point sources), then 

the state’s analysis may reflect that, and 

emissions reductions from such sources 

may still be included in the SIP. 

Response: The section of EPA’s RPG 

Guidance the comment refers to states 

that the guidance is primarily aimed at 

helping states apply the four statutory 

factors to point sources, and that EPA 

recognizes that even though states must 

look at all source categories affecting 

visibility when evaluating the four 

statutory factors, application of some of 

the statutory factors to certain non-point 

sources may not be practical.99 The 

comment appears to imply that this 

section of EPA’s RPG Guidance supports 

the State’s decision not to conduct an 

evaluation of the four statutory factors. 

However, EPA’s RPG Guidance does not 

state, or in any way imply, that 

application of any of the statutory 

factors in considering control measures 

for point sources is not practical. On the 

contrary, EPA’s RPG Guidance clearly 

states that the guidance is mainly aimed 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14629 

100 64 FR 35731. 

101 40 CFR 51.308(d)(1)(iv). 

102 40 CFR 51.308(d)(1)(iii). 

103 64 FR 35732. 

104 64 FR 35732. 

105 64 FR 35721. 

106 64 FR 35733. 

at helping states apply the four statutory 

factors to point sources. 

Comment: There is no requirement in 

the BART Rule for a state to adopt 

control measures that it does not 

consider necessary or reasonable when 

it can be shown that its RPGs represent 

a rate of progress that it and other 

affected states have found to be 

reasonable. The EPA’s role in evaluating 

a state’s RPGs is to assure that other 

affected states have been consulted and 

are satisfied that the RPGs are 

appropriate. In fact, Arkansas’s Class I 

areas as well as Missouri’s Class I areas 

are on the glidepath and are expected to 

meet the rate of progress goals for the 

first implementation period ending in 

2018. 

Response: While EPA agrees that the 

BART Rule does not require a state to 

adopt control measures under 

reasonable progress if the state 

determines that such control measures 

are not reasonable, EPA notes that the 

state must make the determination of 

whether those controls are reasonable or 

not through an evaluation of the four 

statutory factors. The RHR states the 

following: 

‘‘Today’s final rule requires the States to 

determine the rate of progress for remedying 

existing impairment that is reasonable, taking 

into consideration the statutory factors, and 

informed by input from all stakeholders.’’ 100

Arkansas has not considered the four 

statutory factors, and therefore, cannot 

make the claim that additional control 

measures are not reasonable. This is 

especially troublesome in light of the 

fact that there are sources in Arkansas 

not subject to BART which impair 

visibility by more than 0.5 dv, as 

explained in more detail in our 

proposed rulemaking. While EPA agrees 

that one of EPA’s roles in evaluating a 

state’s RPGs is to assure that other 

affected states have been consulted and 

agree with the RPGs the state has 

established,101 EPA notes that our role 

is not limited to just that. The RH 

regulations state the following: 

‘‘In determining whether the State’s goal 

for visibility improvement provides for 

reasonable progress towards natural visibility 

conditions, the Administrator will evaluate 

the demonstrations developed by the State 

pursuant to paragraphs d(1)(i) and (d)(1)(ii) of 

this section.’’ 102

Among the demonstrations the state is 

required to develop pursuant to 40 CFR 

51.308(d)(1)(i) is an evaluation of the 

four statutory factors. As such, EPA’s 

role in evaluating a state’s RPGs is not 

limited to ensuring that other affected 

states have been consulted and agree 

that the state’s RPGs are appropriate. 

With regard to the comment that 

Arkansas Class I areas as well as 

Missouri’s Class I areas are on the 

‘‘glidepath,’’ EPA notes that even if a 

state is projected to meet the URP for its 

Class I areas during the first 

implementation period ending in 2018, 

this is not a safe harbor from more 

stringent regulation. The RHR requires 

states to calculate the URP and 

determine what control measures would 

be needed to achieve this amount of 

progress during the first implementation 

period and to determine whether those 

measures are reasonable based on an 

evaluation of the four statutory 

factors.103 The RHR states the following: 

‘‘If the State determines that the amount of 

progress identified through the analysis is 

reasonable based upon the statutory factors, 

the State should identify this amount of 

progress as its reasonable progress goal for 

the first long-term strategy, unless it 

determines that additional progress beyond 

this amount is also reasonable. If the State 

determines that additional progress is 

reasonable based on the statutory factors, the 

State should adopt that amount of progress 

as its goal for the first long-term strategy.’’ 104

As such, being on the ‘‘glidepath’’ 

does not mean a state is allowed to 

forego an evaluation of the four 

statutory factors when establishing its 

RPGs. Based on an evaluation of the 

four statutory factors, states may 

determine that RPGs that provide for a 

greater rate of visibility improvement 

than would be achieved with the URP 

for the first implementation period are 

reasonable. 

Comment: The EPA’s statement in its 

proposed rulemaking that Arkansas’s 

RH SIP fails to ensure adequate 

reasonable progress toward meeting the 

national visibility goal without 

Arkansas conducting additional analysis 

is not supported by the record. The EPA 

admits that under Arkansas’s RPGs, 

natural visibility conditions will be 

obtained in 2062 for Caney Creek and 

2063 for Upper Buffalo. Based on 

modeling approved by EPA, Arkansas 

will meet the visibility goals as set out 

in the RHR prior to the target date of 

2064. Therefore, the EPA’s position that 

Arkansas must undertake additional 

analysis even though Arkansas’s 

proposed RPGs provide a greater rate of 

improvement in visibility to attain URP 

is incorrect and is an attempt to step on 

the state’s authority. 

Response: The EPA notes that the 

RHR requires states to determine what 

constitutes reasonable progress by, 

among other things, consideration of the 

four statutory factors. The RHR states 

that the determination of what 

constitutes reasonable progress can only 

be made once the necessary technical 

analyses of emissions, air quality, and 

the reasonable progress factors have 

been conducted.105

While in our proposed rulemaking we 

noted that Arkansas calculated that 

under its RPGs, it would attain natural 

visibility conditions in 2062 for Caney 

Creek and 2063 for Upper Buffalo, we 

would like to clarify that such 

calculation assumes that Arkansas 

would be able to achieve the rate of 

improvement reflected by the RPGs for 

the first implementation period ending 

in 2018, and each implementation 

period thereafter. The RHR states the 

following: 

‘‘Once a State has adopted a reasonable 

progress goal and determined what progress 

will be made toward that goal over a 10-year 

period, the goal itself is not enforceable. All 

that is ‘enforceable’ is the set of control 

measures which the State has adopted to 

meet that goal. If the State’s strategies have 

been implemented but the State has not met 

its reasonable progress goal, the State could 

either: (1) Revise its strategies in the SIP for 

the next long-term strategy period to meet its 

goal, or (2) revise the reasonable progress 

goals for the next implementation period. In 

either case, the State would be required to 

base its decisions on appropriate analyses of 

the statutory factors included in 40 CFR 

51.308(d)(1)(i)(A) and (B) of the final 

rule.’’ 106

As such, there is no certainty that the 

State will achieve its RPGs for the first 

implementation period ending in 2018, 

let alone for each implementation 

period thereafter. With regard to the 

comment that the modeling approved by 

EPA shows that Arkansas will meet the 

visibility goals as set out in the RHR 

prior to the target date of 2064, EPA 

notes that the CENRAP modeled the 

projected visibility conditions 

anticipated at each Class I area in 2018. 

The CENRAP modeling is based on 

emissions reductions expected to result 

from Federal, State, and local control 

programs that are either currently in 

effect or with mandated future-year 

emission reduction schedules that 

predate 2018. The CENRAP modeling 

itself did not show that Arkansas will 

meet the visibility goals as set out in the 

RHR prior to 2064. Rather, the rate of 

visibility improvement anticipated by 

the CENRAP modeling projections for 

2018, if sustained, will result in a return 

to natural visibility prior to 2064. This 

assumes that the same level of reduction 

of visibility impairment that is expected 


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14630 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

107 76 FR 64195. 

108 40 CFR 1.308(d)(3). 

109 64 FR 35734. 

110 40 CFR 1.308(d)(3)(v)(C). 

to occur during the first implementation 

period ending in 2018 will occur during 

each implementation period until the 

final implementation period ending in 

2064. However, there is no guarantee 

that this will in fact occur. 

As explained in our proposed 

rulemaking on the Arkansas RH SIP, in 

establishing its RPGs, the State is 

required by CAA § 169A(g)(1) and 40 

CFR 51.308(d)(1)(i)(A) to consider the 

costs of compliance, the time necessary 

for compliance, the energy and non-air 

quality environmental impacts of 

compliance, and the remaining useful 

life of any potentially affected sources, 

and include a demonstration showing 

how these factors were taken into 

consideration in selecting the goal. An 

analysis of the four statutory factors is 

precisely the ‘‘additional analysis’’ EPA 

refers to in its proposed rulemaking on 

the Arkansas RH SIP.107 The RHR does 

not exempt states from evaluating the 

four statutory factors if their RPGs 

provide a greater rate of improvement in 

visibility to attain URP. Since Arkansas 

has not satisfied this requirement, EPA 

disagrees that our disapproval of 

Arkansas’s RPGs is an attempt to step on 

the state’s authority. 

Comment: The EPA’s reliance on 

disapproving the Arkansas LTS based 

on the disapproval of ADEQ’s BART 

determinations is incorrect and not 

consistent with the RHR. Under the 

RHR, states must develop a LTS that 

includes emissions limitations, 

compliance schedules, and other 

measures as necessary to achieve the 

RPGs for Class I areas within a state. 

Arkansas’s LTS complies with the RHR 

by demonstrating that Arkansas will 

meet the visibility goals as set out in the 

RHR prior to the date of 2064 and the 

LTS will help Arkansas achieve its 

RPGs. As such, Arkansas should be 

given the maximum deference in 

attaining those RPGs. In addition, 

ADEQ’s BART determinations are sound 

and are in compliance with the RH 

program. Thus, the EPA should approve 

the portion of the Arkansas RH SIP 

pertaining to its LTS. 

Response: With regard to the 

comment that EPA’s reliance on 

disapproving Arkansas’s LTS based on 

the disapproval of some of Arkansas’s 

BART determinations is incorrect and 

inconsistent with the RHR, EPA clarifies 

that the basis for EPA’s partial 

disapproval of the State’s LTS is that the 

state did not properly consider emission 

limits and schedules for compliance to 

include in its LTS, as required pursuant 

to 40 CFR 51.308(d)(3)(v)(C). Since 40 

CFR 51.308(d)(3)(v)(C) requires that in 

developing its LTS, Arkansas consider 

emissions limitations and schedules of 

compliance to achieve the RPGs, the 

State included the BART emission 

limits it established for its subject to 

BART sources as part of the LTS. As 

explained in our proposed rulemaking, 

EPA disagrees that all of Arkansas’s 

BART determinations are in compliance 

with the RHR. The BART emission 

limits established by Arkansas are an 

element of the LTS, and because we are 

disapproving a portion of Arkansas’s 

BART determinations, it follows that the 

State did not properly consider 

emission limitations and schedules for 

compliance to include in its LTS, as 

required under 40 CFR 

51.308(d)(3)(v)(C). Therefore, we cannot 

approve this element of the LTS. 

Furthermore, as raised by another 

comment, since Arkansas did not 

consider the four statutory factors under 

40 CFR 51.308(d)(1)(i)(A) when 

establishing its RPGs, it is not possible 

to know, at this point, whether requiring 

additional controls for Arkansas source 

categories affecting visibility constitutes 

reasonable progress. This further 

supports our finding that Arkansas has 

not properly considered emission 

limitations and schedules for 

compliance in establishing its LTS, as 

required under 40 CFR 

51.308(d)(3)(v)(C). 

The comment suggests that if a state 

develops a LTS that is expected to 

achieve the state’s RPGs and meet the 

national visibility goal prior to 2064, the 

state will have met the LTS 

requirements in the RHR. While EPA 

agrees that the RHR requires states to 

develop a LTS that includes emissions 

limitations, compliance schedules, and 

other measures as necessary to achieve 

the RPGs established by states having 

mandatory Class I areas,108 EPA notes 

that the RHR establishes several 

requirements a state must satisfy when 

establishing its LTS.109 Among these is 

the requirement for states to consider, at 

a minimum, the seven factors under 40 

CFR 51.308(d)(3)(v). As explained 

above, one of the factors states are 

required to consider is emission 

limitations and schedules for 

compliance to include in the LTS.110

Arkansas has not properly considered 

this factor. Furthermore, as already 

explained above, Arkansas did not 

establish RPGs in accordance with the 

RHR and CAA requirements. As such, 

EPA cannot approve those RPGs. 

Therefore, Arkansas has not 

demonstrated that its LTS includes 

enforceable emissions limitations and 

compliance schedules, as necessary to 

achieve reasonable progress. EPA 

cannot fully approve Arkansas’s LTS. 

Comment: Despite the fact that the 

CENRAP’s modeling for the year 2018 

shows a significant improvement in 

visibility at Caney Creek and Upper 

Buffalo (3.88 dv and 3.75 dv, 

respectively), the available emissions 

data that was used to conduct this 

modeling suggests something different. 

This emissions data shows that SO2

emissions from EGUs in Arkansas are 

projected to increase by roughly 35,000 

tons per year (tpy) between 2002 and 

2018. While non-EGU point source 

emissions of SO2 in Arkansas are 

projected to decrease by 2018, overall 

point source emissions of SO2 (EGU 

plus non-EGU emissions) in Arkansas 

are projected to increase by roughly 

15,000 tpy. When emissions from all 

sources of SO2 in Arkansas are summed 

together (point sources, onroad sources, 

and area sources), SO2 emissions in 

2018 are projected to be higher than 

2002 levels. 

NOX emissions from non-EGUs are 

projected to be 25% higher in 2018 

compared to 2002 levels. Even though 

NOX emissions from non-EGUs are 

projected to decrease between 2002 and 

2018, overall point source NOX

emissions (non-EGUs plus EGUs) are 

projected to increase in 2018 from 2002 

levels. When emissions from all sources 

of NOX in Arkansas are summed 

together (point sources, onroad sources, 

and area sources), NOX emissions in 

2018 are projected to be lower than 2002 

levels, but most of these emissions 

reductions are from onroad sources in 

Arkansas. Also, 2018 emissions of 

PM2.5, PM10, and ammonia (NH3) from 

Arkansas sources were also projected to 

increase somewhat compared to 2002 

levels. Considering that sulfates are the 

significant contributor to visibility 

impairment at both Arkansas Class I 

areas on the majority of the 20% worst 

days, it is difficult to understand how 

the CENRAP 2018 modeling showed 

such a significant improvement in 

visibility when SO2 emissions from 

Arkansas are projected to increase 

between 2002 and 2018. 

EPA also indicated that there is an 

under-prediction bias in the model that 

must be considered when examining 

source apportionment results for sulfate. 

Given that the 2018 modeling reflects a 

low bias in the projection of visibility 

impacts due to sulfates, that there are 

significant projected increases in SO2

emissions from Arkansas point sources 

in 2018, and that the 2018 point source 

emissions from NOX and other visibility 

impairing pollutants are also projected 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14631 

111 76 FR 64206. 

112 64 FR 35740. 

113 76 FR 64206. 

to be higher than 2002 emissions, the 

2018 CENRAP modeling is questionable. 

As discussed by EPA in Appendix A 

to its TSD for its proposed rulemaking 

on the Arkansas RH SIP, it appears that 

the bulk of the projected visibility 

improvement in 2018 in Arkansas’s 

Class I areas may be based on projected 

emissions reductions from sources in 

Texas. However, Texas has 

acknowledged uncertainties in its 2018 

emissions projections, and that the 

Texas emissions inventory is based on 

the Integrated Planning Model (IPM) 

Version 2.19, whereas other planning 

organizations used version 3.0 of the 

IPM, which EPA has indicated provides 

‘‘significantly more accurate prediction 

of future EGU operating scenarios and 

emissions’’ (see Exhibit 21). Texas also 

stated that the IPM Version 2.19 used by 

the CENRAP projected approximately 

14% increase in coal/lignite-fired 

generating capacity and a 32% increase 

in gas-fired capacity in Texas, whereas 

the Electric Reliability Council of Texas 

(ERCOT) predicted a greater percentage 

of growth in coal/lignite-fired generating 

capacity than natural gas-fired capacity 

(see Exhibit 21). Given the uncertainty 

in Texas’ 2018 emission projections and 

that the 2018 modeling may underpredict visibility impacts from sulfates, 

Arkansas should not be allowed to 

forego performing an analysis of 

measures that would enable the state to 

ensure reasonable progress towards 

reaching natural background visibility 

conditions at the State’s Class I areas. 

EPA must disapprove the Arkansas RH 

SIP for failure to include a four-factor 

analysis of reasonable progress 

milestones for the State’s Class I areas. 

As part of a four-factor analysis of 

reasonable progress goals, Arkansas 

should evaluate emission control 

strategies that can be implemented to 

reduce Arkansas’s share of visibilityimpairing pollution. 

Response: The EPA agrees that SO2

emissions from EGUs in Arkansas are 

projected to increase considerably 

between 2002 and 2018, that overall 

point source emissions of SO2 (i.e. EGU 

plus non-EGU emissions) in Arkansas 

are projected to increase by roughly 

15,000 tpy, and that total SO2 emissions 

in Arkansas (i.e. point sources, onroad 

sources, and area sources combined) are 

projected to increase between 2002 and 

2018. We also agree that even though 

total NOX emissions in Arkansas (i.e. 

point sources, onroad sources, and area 

sources combined) are projected to 

decrease in 2018 from 2002 levels, most 

of these emissions reductions are from 

onroad sources in Arkansas. As 

discussed in Appendix A of the TSD for 

our proposed action on the Arkansas RH 

SIP, we agree that the modeling 

demonstrates that most of the projected 

visibility improvement in 2018 in Caney 

Creek appears to be based on projected 

emissions reductions from sources in 

Texas and that Texas has acknowledged 

that there are uncertainties in its 2018 

emissions projections. Consistent with 

the points raised in the comment, we 

are disapproving Arkansas’s RPGs for 

Caney Creek and Upper Buffalo. As 

discussed in our proposed rulemaking 

and in our response to previous 

comments, Arkansas must evaluate the 

four statutory factors when establishing 

its RPGs. As part of its evaluation of the 

four statutory factors Arkansas must 

determine what (if any) level of control 

is reasonable to require sources in 

Arkansas to comply with to achieve 

reasonable progress at Arkansas’s Class 

I areas. 

C. Comments on BART 

1. Evaluation of the Most Stringent 

Level of Control in the BART Analysis 

Comment: The EPA pointed out that 

Entergy White Bluff did not evaluate the 

most stringent level of control 

achievable in that it did not evaluate 

emission limits lower than the 

presumptive SO2 BART emission limit 

of 0.15 lb/MMBtu for either a wet or a 

dry scrubber, but EPA did not mention 

that both wet and dry scrubbers can 

achieve greater than the control 

efficiencies assumed in the White Bluff 

analysis (i.e. greater than 95% control 

with a wet scrubber, and greater than 

92% control with a dry scrubber). EPA 

pointed out that SO2 emission rates as 

low as 0.065 lb/MMBtu have been 

documented with installation of dry 

scrubbers. EPA recently proposed a FIP 

requiring the installation of dry 

scrubbers as BART at six coal-fired 

EGUs in Oklahoma, to achieve the SO2

BART emission limit of 0.06 lb/MMBtu 

on a 30-day rolling average basis (76 FR 

16187–188, 16193–194). These units 

burn similar low sulfur coal as that 

primarily burned at the Entergy White 

Bluff Units 1 and 2. A limit of 0.06– 

0.065 lb/MMBtu would reflect 92.2% to 

92.8% removal from the highest SO2

rate identified by Entergy during the 

base case of 0.83 lb/MMBtu. Therefore, 

SO2 emission rates much lower than 

0.15 lb/MMBtu should be achievable 

with the installation of a wet scrubber 

or a dry scrubber/baghouse at White 

Bluff Units 1 and 2. Wet scrubbers can 

achieve 98–99% SO2 removal and dry 

scrubbers can achieve 95% SO2 removal 

(see Exhibits 17, 17A, 17B, 17C, and 

17D). An October 2008 Sargent & Lundy 

study of SO2 control technologies for 

White Bluff makes clear that dry 

scrubbers are capable of 95% removal 

efficiency, and wet scrubbers are 

capable of 95–99% removal efficiency 

(see Exhibit 16). This study also 

indicates that the typical Powder River 

Basin coal SO2 emission rates expected 

from wet scrubbers ranges from 0.03 to 

0.10 lb/MMBtu, and for dry scrubbers 

ranges from 0.06 to 0.12 lb/MMBtu. 

Therefore, EPA should require 

consideration of emission limits more 

stringent than ADEQ’s proposed SO2

BART limit of 0.15 lb/MMBtu. 

Response: The EPA agrees that wet 

scrubbers for control of SO2 emissions 

have been demonstrated to achieve as 

high as 98–99% removal efficiency, 

while dry scrubbers have been 

demonstrated to achieve as high as 95% 

removal efficiency. SO2 emission rates 

much lower than 0.15 lbs/MMBtu are 

achievable at Entergy White Bluff Units 

1 and 2 with the installation of a wet or 

dry scrubber. This is consistent with our 

proposed rulemaking on the Arkansas 

RH SIP, in which we noted that the 0.15 

lb/MMBtu presumptive SO2 limit the 

State established for both the 

bituminous and sub-bituminous coal 

firing scenarios for White Bluff Units 1 

and 2 corresponds to 82% control 

removal of the wet scrubber at Unit 1 

and 80% control removal of the wet 

scrubber at Unit 2, while such controls 

are capable of a higher control 

efficiency.111 EPA’s proposed 

rulemaking proposed to disapprove the 

State’s determination that SO2 BART for 

White Bluff Units 1 and 2 is the 

presumptive limit of 0.15 lb/MMBtu for 

both the sub-bituminous and 

bituminous coal firing scenarios, as the 

State is required to evaluate the cost and 

visibility impact of operating controls at 

the maximum control efficiency 

achievable (i.e. to achieve the most 

stringent emission limit capable of being 

achieved by those controls).112,113

Comment: A study conducted by 

Babcock & Wilcox at tangentially-fired 

units burning sub-bituminous Powder 

River Basin coal showed NOX emission 

rates with ultra low NOX burners and 

overfire air that were generally less than 

0.13 lb/MMBtu (see Exhibit 17F). The 

proposed NOX limits for White Bluff 

Units 1 and 2 of 0.15 lb/MMBtu when 

burning sub-bituminous coal and 0.28 

lb/MMBtu when burning bituminous 

coal do not reflect the capability of the 

state of the art low NOX burners and 

overfire air. Also, since the White Bluff 

Units 1 and 2 burn primarily subbituminous coal, EPA’s presumptive 

BART limit for sub-bituminous coal 


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14632 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

114CAA section 169A(g)(2). 

115Appendix Y to Part 41, section IV.D. 

116 40 CFR 51.308(e)(1)(ii)(A). 

117 64 FR 35740. 

118 76 FR 64202. 

119 64 FR 35740. 

120 76 FR 64202. 

(and not for bituminous coal) should be 

evaluated. The BART Guidelines do not 

provide for prorating the presumptive 

BART limits based on the percentages of 

each coal burned. Presumptive limits 

should be defined by the coal type 

predominantly burned by the White 

Bluff units and BART must be based on 

the coal the units have historically 

burned, not on the type of coal that 

might be used in the future. 

Response: The EPA agrees that the 

NOX limits adopted by the State of 0.15 

lb/MMBtu when burning subbituminous coal and 0.28 lb/MMBtu 

when burning bituminous coal for 

White Bluff Units 1 and 2 do not reflect 

the capability of the state of the art low 

NOX burners and overfire air. 

In addition, the BART Rule and the 

BART Guidelines do not specify 

whether a state can make separate BART 

determinations for each type of fuel 

burned by a given source. This should 

not be interpreted to mean that a state 

is not allowed to make separate BART 

determinations for each fuel type 

burned by a given source. The CAA and 

BART Rule give states broad authority 

in making BART determinations. 

Accordingly, States may determine it is 

appropriate to make BART 

determinations for each type of fuel 

burned by a given source. EPA 

acknowledges that the BART Guidelines 

do not specifically mention whether or 

not states can prorate the presumptive 

BART limits based on the percentages of 

each coal burned. However, if a source 

has a history of burning more than one 

type of fuel, then the BART 

determination must either be based on 

the fuel resulting in the greatest amount 

of emissions or the State must consider 

BART for each fuel type. 

Comment: BART is not the maximum 

feasible technology but only the 

technology that is appropriate as 

determined by the state in weighing the 

public interest factors. EPA is incorrect 

in its assertion that the BART 

Guidelines require consideration of the 

most stringent control technology in the 

BART analysis. The EPA is going 

beyond the scope of the CAA by 

proposing that BART analysis requires 

identification and evaluation of the 

maximum control technology available 

when the state conducts BART 

evaluations. 

Response: The EPA agrees that BART 

is not defined as the ‘‘maximum feasible 

technology.’’ However, EPA disagrees 

that EPA is going beyond the scope of 

the CAA by stating that states must 

evaluate the most stringent controls 

available in their BART evaluations. 

The BART Guidelines explicitly require 

consideration of the most stringent 

control technology in the BART 

analysis. The CAA states the following: 

‘‘[I]n determining best available retrofit 

technology the State (or the Administrator in 

determining emission limitations which 

reflect such technology) shall take into 

consideration the costs of compliance, the 

energy and non-air quality environmental 

impacts of compliance, any existing 

pollution control technology in use at the 

source, the remaining useful life of the 

source, and the degree of improvement in 

visibility which may reasonably be 

anticipated to result from the use of such 

technology * * *’’ 114

In accordance with the CAA, EPA 

promulgated the BART Rule and the 

BART Guidelines to clarify the 

requirements of the RHR’s BART 

provisions. The BART Guidelines 

provide the following: 

‘‘In identifying ‘‘all’’ options, you must 

identify the most stringent option and a 

reasonable set of options for analysis that 

reflects a comprehensive list of available 

technologies. It is not necessary to list all 

permutations of available control levels that 

exist for a given technology-the list is 

complete if it includes the maximum level of 

control each technology is capable of 

achieving.’’ 115

Furthermore, the RH regulations 

define BART as the best system of 

continuous emission control technology 

available and associated emission 

reductions achievable, as determined 

through an evaluation of the five 

statutory factors.116 As explained in our 

proposed rulemaking on the Arkansas 

RH SIP, the RHR states that since recent 

retrofits at existing sources provide a 

good indication of the current ‘‘best 

system’’ for controlling emissions, these 

controls must be considered in the 

BART analysis.117 118 EPA’s proposed 

rulemaking also explains that the RHR 

provides that in establishing source 

specific BART emission limits, a state’s 

BART analysis must identify and 

consider the maximum level of emission 

reduction that has been achieved in 

other recent retrofits at existing sources 

in the source category.119 120

2. Evaluation of Post-Combustion 

Controls in the BART Analysis 

Comment: We agree with EPA’s 

proposal that the White Bluff Units 1 

and 2 BART analysis for NOX in the 

Arkansas RH SIP only evaluated options 

to comply with the presumptive BART 

limits and the company failed to 

evaluate add-on NOX controls such as 

SCR and SNCR. NOX emission limits as 

low as 0.05 lb/MMBtu, achieved by the 

installation of SCR, have been 

promulgated as BART limits for EGUs 

such as the San Juan power plant in 

New Mexico (76 FR 52390, 52439). SCR 

along with combustion controls are 

routinely required as BACT today for 

proposed new coal-fired power plants. 

SCR along with combustion controls 

have also been required as BART or to 

meet RH progress goals at several coal 

fired power plants, including the 

Boswell Energy Center Unit 3 and the 

Alan S. King Unit 1 facility in 

Minnesota (see Minnesota Air Pollution 

Control Agency revised draft RH SIP, 

July 2009); Naughton Unit 3 and Jim 

Bridger Units 3 and 4 in Wyoming (see 

Wyoming draft RH SIP, January 2011); 

San Juan Units 1–4 (see 76 FR 52388); 

Four Corners Units 1–5 (See 75 FR 

64230); and Big Stone Unit 1 (see EPA’s 

November 29, 2011 proposed 

rulemaking on the South Dakota RH 

SIP). Installation of SCR along with 

combustion controls has been found to 

be cost-effective both in BART and 

BACT determinations, with costs 

ranging from approximately $4200/ton 

NOX removed all the way up to $21,000/ 

ton NOX removed (see Exhibit 17, 17H, 

17I, 17J, and 17K). According to data 

compiled by the National Parks Service, 

the cost effectiveness of SCR controls at 

units required to install such controls to 

meet RH requirements has ranged from 

$2,200 to $4,300/ton NOX removed (see 

Exhibit 19). White Bluff would greatly 

reduce NOX emissions beyond that 

achieved by the combustion controls 

proposed as BART if it were to install 

SCRs as BART at each unit. If SCR had 

been evaluated as BART at White Bluff 

Units 1 and 2, NOX emissions would 

have been 78% lower when the units 

burn sub-bituminous coal and 82% 

lower when the units burn bituminous 

coal. Based on testimony before the 

Arkansas Public Service Commission, 

Entergy appears to be planning to install 

SCR at both units at some point in the 

near future (see Exhibit 17L). Entergy’s 

NOX BART analysis for White Bluff 

cannot be considered complete without 

an evaluation of combustion controls 

plus SCR. 

Response: The EPA agrees that 

installation and operation of SCR as 

BART could potentially result in the 

reduction of NOX emissions beyond that 

achieved by operation of the 

combustion controls proposed by the 

State as BART for White Bluff Units 1 

and 2. EPA also agrees that the State 

must evaluate SCR controls when it 

evaluates what is BART for Entergy 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14633 

121 76 FR 64201. 

122 70 FR 39136. 

123 70 FR 39132. 

124 40 CFR 51.308(e)(1)(ii)(A). 

125 64 FR 35740. 

126 76 FR 64202. 

127 64 FR 35740. 

128 76 FR 64202. 

129Appendix Y to Part 51, section IV.E.4. 

130 40 CFR 51.308(e)(1)(ii)(A). 

131 64 FR 35740. 

132 76 FR 64202. 

133 64 FR 35740. 

134 76 FR 64202. 

White Bluff Units 1 and 2. As explained 

elsewhere in this final rulemaking, we 

are finalizing our proposed disapproval 

of the State’s NOX BART determination 

(bituminous and sub-bituminous coal 

firing scenarios) for White Bluff Units 1 

and 2. 

Comment: Since EPA explicitly did 

not evaluate post combustion controls 

in establishing presumptive limits for 

EGUs that burn coal and do not have 

existing post-combustion controls for 

NOX in the BART Guidelines, post 

combustion controls should not be 

required to be evaluated as part of 

Arkansas’s NOX BART evaluations of 

Entergy’s White Bluff facility. In 

addition, since EPA explicitly did not 

evaluate post combustion technology 

when establishing presumptive limits 

for boilers other than cyclone units in 

the BART Guidelines, post combustion 

controls should not be required to be 

evaluated as part of the Arkansas BART 

evaluations for Lake Catherine facility. 

Response: The EPA agrees that we did 

not evaluate post-combustion controls 

in providing NOX presumptive emission 

limits for EGUs that burn coal and have 

no existing post-combustion controls. 

The EPA also points out the BART 

Guidelines did not provide presumptive 

limits for oil-fired units such as Entergy 

Lake Catherine Unit 4. This does not 

mean that Arkansas may forego an 

evaluation of post-combustion controls 

in its NOX BART analyses for Entergy 

White Bluff Units 1 and 2 and Lake 

Catherine Unit 4. As stated in our 

proposed rulemaking on the Arkansas 

RH SIP, the purpose of the presumptive 

limits in the BART Guidelines was to 

identify controls that the Agency 

considered to be generally cost-effective 

across all affected units.121 Because 

EPA’s extensive analysis found that 

these controls are generally costeffective across all affected units and 

were anticipated to result in a 

substantial degree of visibility 

improvement, EPA concluded that such 

affected units should at least meet the 

presumptive limits unless the state finds 

that a more or less stringent emission 

limit is BART based on a consideration 

of the five statutory factors. EPA’s intent 

was for these generally cost-effective 

controls to be used in the State’s BART 

analysis considering the five factors 

specified in CAA section 169A(g)(2), 

and considering the level of control that 

is currently achievable at the time that 

the BART analysis is being conducted. 

Further, in the BART Rule, EPA 

justified its decision not to establish 

presumptive NOX limits based on the 

use of SCR for units other than cyclone 

units, stating the following: 

‘‘For other units, we are not establishing 

presumptive limits based on the installation 

of SCR. Although States may in specific cases 

find that the use of SCR is appropriate, we 

have not determined that SCR is generally 

cost-effective for BART across unit types.’’ 122

As such, in the BART Guidelines, 

EPA simply concluded that it could not 

reach a generalized conclusion as to the 

appropriateness of more stringent 

controls (i.e. post-combustion controls) 

for coal-fired EGUs without existing 

post-combustion controls. Similarly, 

EPA concluded that it could not reach 

a generalized conclusion as to the 

appropriateness of providing 

presumptive limits based on the 

installation of SCR (or even combustion 

controls for that matter) for oil-fired 

units. This does not mean that states 

should not evaluate post-combustion 

NOX controls at affected sources. As 

explained elsewhere in this final 

rulemaking, in response to comments on 

the proposed BART Guidelines that the 

presumptive SO2 EGU limits should be 

more stringent, EPA justified its 

decision to not provide more stringent 

presumptive emission limits by 

explaining that after considering the five 

statutory factors, States may find that a 

more or less stringent emission limit is 

BART [emphasis added].123 Similar 

statements are made elsewhere in the 

BART Rule. 

Furthermore, the RH regulations 

define BART as the best system of 

continuous emission control technology 

available and associated emission 

reductions achievable, as determined 

through an evaluation of the five 

statutory factors.124 As explained in our 

proposed rulemaking on the Arkansas 

RH SIP, the RHR states that since recent 

retrofits at existing sources provide a 

good indication of the current ‘‘best 

system’’ for controlling emissions, these 

controls must be considered in the 

BART analysis.125 126 EPA’s proposed 

rulemaking also explains that the RHR 

provides that in establishing source 

specific BART emission limits, a state’s 

BART analysis must identify and 

consider the maximum level of emission 

reduction that has been achieved in 

other recent retrofits at existing sources 

in the source category.127 128 In most 

cases, the maximum level of emission 

reduction is achieved through the 

installation and operation of postcombustion controls. Therefore, the 

State should evaluate post-combustion 

controls in its BART analysis for 

Entergy White Bluff Units 1 and 2. 

Comment: The BART Guidelines 

indicate that States should only 

consider the installation of current 

combustion control technology on oil 

and gas-fired units. Therefore, EPA 

cannot disapprove BART 

determinations on the basis that post 

combustion control technology was not 

evaluated for Entergy’s Lake Catherine 

Unit 4. 

Response: The EPA disagrees that the 

BART Guidelines indicate that States 

should only consider the installation of 

current combustion control technology 

on oil and gas-fired units. The BART 

Guidelines state the following: 

‘‘For oil-fired and gas-fired EGUs larger 

than 200 MW, we believe that installation of 

current combustion control technology to 

control NOX is generally highly cost-effective 

and should be considered in your 

determination of BART for these sources.’’ 129

The context of the above statement is 

with regard to whether EPA believed a 

presumptive emissions limit is 

appropriate for gas fired and fuel oil 

fired EGUs. It was not intended to limit 

the consideration for BART for these 

sources to combustion controls only. 

The BART Guidelines should not be 

interpreted to mean that states should 

not consider NOX post-combustion 

controls in their BART analyses for gas 

fired and oil fired units. The RH 

regulations define BART as the best 

system of continuous emission control 

technology available and associated 

emission reductions achievable, as 

determined through an evaluation of the 

five statutory factors.130 As explained in 

our proposed rulemaking on the 

Arkansas RH SIP, the RHR states that 

since recent retrofits at existing sources 

provide a good indication of the current 

‘‘best system’’ for controlling emissions, 

these controls must be considered in the 

BART analysis.131 132 EPA’s proposed 

rulemaking also explains that the RHR 

provides that in establishing source 

specific BART emission limits, a state’s 

BART analysis should identify and 

consider the maximum level of emission 

reduction that has been achieved in 

other recent retrofits at existing sources 

in the source category.133 134 In most 

cases, the maximum level of emission 

reduction is achieved through the 


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14634 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

135Appendix Y to Part 51, section IV.D.2. 

136 76 FR 64209. 137 70 FR 39123. 

138 70 FR 39131. 

139Appendix Y to Part 51, section IV.E.2. 

installation and operation of postcombustion controls. Therefore, the 

State must evaluate post-combustion 

control technology in its BART analysis 

for Entergy Lake Catherine Unit 4. 

Comment: The EPA cannot 

disapprove the NOX BART 

determinations for the Domtar Ashdown 

Mill Power Boilers No. 1 and 2 for not 

evaluating SNCR. While SNCR has been 

installed on several industrial boilers 

similar to Domtar’s Boilers, at the time 

that the BART evaluation was 

conducted, SNCR was not available. 

Even if you considered SNCR and a 

50% reduction in emissions (the upper 

level of control expected with SNCR) 

less than 10 days of impacts greater than 

0.5 dv would be eliminated. Thus, the 

cost of SNCR is not appropriate, 

especially considering Arkansas is 

already achieving progress toward the 

overall goal of the RH program. 

Response: The BART Guidelines 

provide the following: 

‘‘In order to provide certainty in the 

process, all technologies should be 

considered if available before the close of the 

State’s public comment period. You need not 

consider technologies that become available 

after this date. As part of your analysis, you 

should consider any technologies brought to 

your attention in public comments. If you 

disagree with public comments asserting that 

the technology is available, you should 

provide an explanation for the public record 

as to the basis for your conclusion.’’ 135

As pointed out in our proposed 

rulemaking on the Arkansas RH SIP, 

SNCR was available for industrial 

boilers similar to Domtar’s boilers before 

the close of the State’s public comment 

period.136 As documented by Arkansas 

in Appendix 2.1 of its RH SIP, EPA 

provided comments to Arkansas on this 

matter on May 1, 2007. This was far in 

advance of the end of the State’s public 

comment period. As documented in 

Appendix 2.1 of the Arkansas RH SIP, 

the State did not provide any form of 

response to EPA’s comment, nor did the 

State evaluate operation and installation 

of SNCR at Domtar Ashdown Mill 

Power Boilers No. 1 and 2. 

Since the State did not conduct 

modeling to evaluate the visibility 

impact of operation of SNCR at Domtar 

Power Boilers No. 1 and 2, it is not clear 

how one could reach a conclusion that 

SNCR would result in the elimination of 

less than 10 days of impacts greater than 

0.5 dv. Furthermore, the RHR and BART 

Guidelines require states to consider all 

five statutory factors, and not just the 

visibility impact resulting from 

operation of SNCR. The BART Rule 

states the following: 

‘‘[T]he degree of improvement in visibility 

which may reasonably be anticipated to 

result from the use of [BART]’’ is only one 

of five criteria that the State must consider 

together in making a BART 

determination.’’ 137

A proper evaluation of SNCR, through 

a consideration of the five statutory 

factors, may demonstrate that 

installation and operation of SNCR at 

Domtar Power Boilers 1 and 2 is costeffective. As such, EPA cannot approve 

the State’s NOX BART determinations 

for the Domtar Power Boilers No. 1 and 

2. 

Comment: The EPA is incorrect in 

stating that not all technically feasible 

options were considered and visibility 

impacts considered for the NOX BART 

determination for Domtar. Methane DeNOX (MdN) is the only control 

technology deemed technically feasible 

for which modeling was not completed. 

The technical capability of MdN is 

highly questionable. There is no reason 

to complete a modeling analysis for this 

option because it was cost prohibitive 

regardless of what visibility 

improvement may be gained from its 

use. Because of this, the decision was 

made to forgo the modeling. Such a 

decision is within ADEQ’s discretionary 

authority to weigh the BART factors as 

they feel appropriate as spelled out in 

the BART Guidelines. This decision is 

reasonable since ADEQ is already 

achieving better than necessary progress 

towards attaining its visibility goals. 

Response: The EPA stands by the 

statement made in its proposed 

rulemaking on the Arkansas RH SIP that 

not all technically feasible options were 

considered for the NOX BART 

determination for Domtar Power Boilers 

1 and 2. As explained in our proposed 

rulemaking and elsewhere in our 

response to comments, Arkansas did not 

evaluate SNCR controls even though 

such NOX control is technically feasible, 

having been demonstrated at industrial 

boilers similar to Domtar Power Boilers 

No. 1 and 2 well in advance of the end 

of the State’s public comment period for 

the Arkansas RH SIP. 

EPA also stands by the statement 

made in its proposed rulemaking on the 

Arkansas RH SIP that the State did not 

evaluate the visibility impact of all 

technically feasible options. The 

preamble to the RHR states the 

following: 

‘‘We agree with commenters who asserted 

that the method for assessing BART controls 

for existing sources should consider all of the 

statutory factors.’’ 138

The BART Guidelines also provide 

the following with regard to the 

selection of BART: 

‘‘You have discretion to determine the 

order in which you should evaluate control 

options for BART. Whatever the order in 

which you choose to evaluate options, you 

should always (1) display the options 

evaluated; (2) identify the average and 

incremental costs of each option; (3) consider 

the energy and non-air quality environmental 

impacts of each option; (4) consider the 

remaining useful life; and (5) consider the 

modeled visibility impacts.’’ 139

Therefore, in their BART evaluations, 

States must consider the visibility 

impact of a control option before 

eliminating it. In particular, for Domtar 

Power Boiler No. 1, for which the State 

determined that NOX BART is no 

additional controls (resulting in no 

emissions reductions or visibility 

improvement beyond baseline levels), 

an evaluation of all five statutory factors 

is necessary before the State can make 

the determination that no retrofit 

controls are available for Domtar Power 

Boiler No. 1. 

The EPA disagrees with the comment 

that the decision to forego modeling the 

visibility impacts of Methane De-NOX

(the only technically feasible control 

option the State identified for Domtar 

Power Boiler 1) is reasonable since 

ADEQ is already achieving better than 

necessary progress towards attaining its 

visibility goals. EPA would like to 

clarify that the State is not already 

achieving better than necessary progress 

towards attaining its visibility goals, as 

the commenter’s statement is based on 

modeling projections based on 

emissions reductions resulting from 

BART and the implementation of other 

CAA requirements, and many of these 

emissions reductions have yet to take 

place. Furthermore, as explained in 

more detail in our proposed rulemaking 

on the Arkansas RH SIP and elsewhere 

in our response to comments, EPA is 

disapproving the State’s RPGs because 

the State did not evaluate the four 

statutory factors under 40 CFR 

51.308(d)(1)(i)(A). Therefore, the claim 

that Arkansas is already achieving better 

than necessary progress towards 

attaining its visibility goals cannot be 

made. 

Comment: In addition to reducing 

visibility impairing regional haze, SCR 

systems can oxidize elemental mercury, 

making it easier to capture downstream 

in wet flue gas desulfurization (FGD) 

systems or PM collection devices. 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14635 

140These documents can be found in the docket 

associated with our final rulemaking. 141 70 FR 39116. 

Industry improvements in SCR 

technology that would enhance mercury 

oxidation for all coal types are currently 

being developed. Significant mercury 

reductions would be a likely co-benefit 

if an SCR is coupled with a baghouse 

designed for state-of-the-art PM control. 

Response: While EPA agrees that SCR 

technology coupled with a baghouse 

may result in significant reductions in 

mercury emissions, EPA notes that 

mercury is not considered a visibility 

impairing pollutant. As such, the 

control of mercury emissions is outside 

the scope of the RHR. However, if in 

evaluating control technologies for a 

BART pollutant for a given source, a 

state finds that two or more technologies 

(or combination of technologies) would 

have similar visibility benefits, the state 

may justify selection of one of the 

technologies on the basis of its non-air 

quality environmental benefits. For 

example, a state may justify selection of 

SCR technology coupled with a 

baghouse to control NOX emissions over 

a different control option on the basis 

that SCR coupled with a baghouse 

would result in less mercury emissions 

going into the soil or a nearby body of 

water. That being said, as explained in 

our proposed rulemaking on the 

Arkansas RH SIP and elsewhere in our 

response to comments, Arkansas must 

evaluate NOX post-combustion controls 

(i.e. SCR and SNCR) in its BART 

analyses for subject to BART sources. 

Comment: SCR would remove up to 

3,832 tpy NOX per unit at Entergy White 

Bluff beyond what the combustion 

controls currently proposed to meet 

BART would remove. Visibility in the 

Region’s Class I areas would further be 

improved by the NOX emissions 

reductions achievable with combustion 

controls plus SCR at White Bluff Units 

1 and 2, especially since, as EPA stated 

in its proposed rulemaking, a 

‘‘considerable portion’’ of the visibility 

impairment in the Class I areas of 

Arkansas and Missouri is due to NOX

emissions (76 FR 64207). According to 

EPA’s AirData Web site, in 2002, the 

most recent year of emissions data in 

the AirData system, White Bluff was the 

largest industrial source of NOX

emissions in the state. Therefore, it is 

necessary that a complete and proper 

evaluation of SCR and combustion 

controls be conducted to determine 

BART for White Bluff Units 1 and 2. 

Response: Consistent with our 

proposed rulemaking on the Arkansas 

RH SIP and other responses to other 

comments, EPA agrees that the State 

must conduct a BART analysis that 

properly evaluates both combustion and 

post-combustion controls at Entergy 

White Bluff Units 1 and 2. 

3. Comments on the State’s PM BART 

Emission Limits We Proposed To 

Approve 

Comment: BART is based on a fivefactor analysis, and the requirement for 

a five-factor analysis stems from 

statutory and regulatory requirements 

regarding how BART is to be 

determined (see 40 CFR 

51.308(e)(1)(ii)(A) and section 169A(g) 

of the CAA, 42 U.S.C. 7491(g)). A proper 

evaluation of BART for White Bluff 

Units 1 and 2 and Flint Creek Boiler No. 

1 would have shown that each sources’ 

existing PM limit does not reflect PM 

BART for the sources. 

Response: In our review of the 

Arkansas RH SIP, we evaluated the 

determination by ADEQ that no 

additional PM controls were required at 

the AEP Flint Creek Boiler No. 1 or the 

Entergy White Bluff Units 1 and 2. For 

Flint Creek Boiler No. 1, ADEQ’s 

determination was based on the precontrol modeling performed by ADEQ 

and on AEP SWEPCO’s statement that 

the PM visibility modeling did not ‘‘trip 

the BART impact threshold.’’ We 

reviewed the pre-control modeling 

performed by ADEQ using the 24-hr 

actual maximum emissions from the 

baseline period. The modeling results in 

Appendix 9.2B of the Arkansas RH SIP 

and presented in Table 7–6 of Appendix 

A of the TSD,140 indicate that PM 

contributes less than 0.5% of the total 

visibility impacts from Flint Creek 

Boiler No. 1 at all nearby Class I areas 

with the exception of Upper Buffalo. PM 

contributions to visibility impacts at 

Upper Buffalo from Flint Creek are less 

than 2% of the total visibility 

impairment at this Class I area. On the 

most impacted day at Upper Buffalo, 

modeling the 24-hr actual maximum 

emissions demonstrates that PM 

contributes only 0.07 dv of the total 

3.781 dv modeled visibility impact from 

the source. Clearly, the most effective 

controls to address visibility 

impairment from the source are those 

that would reduce emissions of 

visibility impairing pollutants other 

than direct emissions of PM. 

For White Bluff Units 1 and 2, we 

reviewed the data submitted by ADEQ, 

including pre-control modeling in 

Appendix 9.2B of the Arkansas RH SIP, 

to evaluate ADEQ and White Bluff’s 

determination that the majority of 

visibility-causing emissions are due to 

emissions of NOX and SO2, and that no 

additional PM controls are warranted. 

The modeling results in Appendix 9.2B 

of the Arkansas RH SIP and presented 

in Table 7–7 of Appendix A of the TSD 

for our proposed rulemaking, indicate 

that PM contributes less than 0.4% of 

the total visibility impacts at all nearby 

Class I areas. On the most impacted day 

at Caney Creek, modeling the 24-hr 

actual maximum emissions 

demonstrates that PM contributes only 

0.03 dv of the more than 8 dv modeled 

visibility impact from the White Bluff 

Units 1 and 2. Clearly, the majority of 

visibility-causing emissions are due to 

emissions of NOX and SO2 and the most 

effective controls to address visibility 

impairment from the units are those that 

would reduce emissions of NOX and 

SO2 rather than direct emissions of PM. 

As explained in our proposed 

rulemaking, in our evaluation for PM 

BART for these sources, we found that 

the visibility impact due to PM 

emissions alone is so minimal such that 

any additional PM controls could only 

result in very minimal visibility benefit 

that could not justify the cost of any 

upgrades and/or operational costs 

needed to operate the existing controls 

to achieve a more stringent emission 

limit. This is in keeping with the BART 

Rule, which provides the following: 

‘‘Consistent with the CAA and the 

implementing regulations, States can adopt a 

more streamlined approach to making BART 

determinations where appropriate. Although 

BART determinations are based on the 

totality of circumstances in a given situation, 

such as the distance of the source from a 

Class I area, the type and amount of pollutant 

at issue, and the availability and cost of 

controls, it is clear that in some situations, 

one or more factors will clearly suggest an 

outcome. Thus, for example, a State need not 

undertake an exhaustive analysis of a 

source’s impact on visibility resulting from 

relatively minor emissions of a pollutant 

where it is clear that controls would be costly 

and any improvements in visibility resulting 

from reductions in emissions of that 

pollutant would be negligible. In a scenario, 

for example, where a source emits thousands 

of tons of SO2 but less than one hundred tons 

of NOX, the State could easily conclude that 

requiring expensive controls to reduce NOX

would not be appropriate.’’ 141

Therefore, we are approving the 

State’s determination that PM BART for 

Flint Creek Boiler No. 1 and White Bluff 

Units 1 and 2 is the existing PM 

emission limit (i.e. no additional 

controls). 

Comment: The EPA should not 

partially approve the State’s BART 

determination for a given source for 

some pollutants and disapprove the 

BART determination for other 

pollutants without also concurrently 

promulgating BART requirements for 

the pollutants that have been 

disapproved. EPA should not approve 


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14636 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

142The Arkansas Public Service Commission is 

an appointed executive board in the Arkansas state 

government. The commission is responsible for 

regulating the rates and services of Arkansas’s 

electricity, natural gas, water, phone, and pipeline 

safety utilities. 

143See Exhibit 12 to Sierra Club’s comment letter 

to EPA, found in the docket for this rulemaking 

action. 144Appendix Y to Part 51, section III.A.2. 

the PM BART controls for the AEP Flint 

Creek Power Plant, the Entergy White 

Bluff Power Plant, and the No. 1 Power 

Boiler of the Domtar Ashdown Mill 

before knowing what the SO2 and NOX

BART controls will be because the SO2

or NOX controls determined to be BART 

may increase PM emissions or otherwise 

affect the PM BART determination. 

Response: You cannot infer from the 

RHR that the disapproval of the BART 

determination for one pollutant at a 

given source requires disapproval of 

BART determinations for other 

pollutants at the same source. Each 

BART analysis for an individual 

visibility impairing pollutant is 

separate. As such, disapproval of the 

SO2 or NOX BART determination does 

not affect the PM BART determination 

even though SO2 and NOX are 

precursors to PM. This is because when 

the BART determination is conducted 

for PM, it is analyzed without taking in 

account whether BART controls for SO2

or NOX are being adopted. As such, EPA 

may take action on the BART 

determinations for NOX, SO2, and PM 

for a given source in separate 

rulemaking actions. In addition, EPA 

may approve the BART determination 

for one pollutant for a given source 

while disapproving the BART 

determination for one or more 

pollutants at the same source. Therefore, 

EPA disagrees with the commenter that 

it cannot approve the PM BART 

determinations for the Flint Creek Boiler 

No. 1, the White Bluff Units 1 and 2, 

and the Domtar Ashdown Mill Power 

Boiler No. 1, and disapprove the SO2

and NOX BART determinations for these 

sources without promulgating SO2 and 

NOX BART determinations for these 

sources in the context of a FIP. 

As explained in our proposed 

rulemaking and elsewhere in this final 

rulemaking, our disapproval begins a 

two year period after which if Arkansas 

has not provided a new SIP revision and 

EPA has approved that SIP revision 

correcting the deficiencies, EPA must 

promulgate a FIP. If in conducting the 

BART analyses for NOX and SO2, 

Arkansas, or EPA in the context of a FIP, 

determines that direct emissions of PM 

will increase because of the 

implementation of certain control 

technologies, the BART PM limit can be 

re-evaluated at that time and balanced 

against the potential visibility 

improvements from the reductions of 

the other pollutants. 

Comment: In the testimony for a 

permit proceeding, Entergy’s primary 

contractor for engineering and 

procurement of its BART controls 

showed that PM emission rates much 

lower than 0.1 lb/MMBtu could be met 

with either a wet scrubber or with a dry 

scrubber and a baghouse installed at the 

Entergy White Bluff Units 1 and 2 (see 

Exhibits 12 and 16). Entergy’s contractor 

indicated that if a dry scrubber and 

baghouse were installed at White Bluff 

Units 1 and 2, the baghouse would be 

designed to lower the PM emissions to 

0.012 lb/MMBtu, giving an advantage of 

the dry scrubber over the wet scrubber. 

Since the selection of the SO2 scrubber 

(wet vs. dry) will have an impact on the 

PM emissions rate that will be 

achievable at the White Bluff units, EPA 

should not take any action on PM BART 

for White Bluff until the SO2 controls to 

meet BART are known. 

Response: The comment points out 

that in the testimony for a permit 

proceeding before the Arkansas Public 

Service Commission,142 Entergy’s 

contractor indicated that if a dry 

scrubber and baghouse are installed at 

the Entergy White Bluff Units 1 and 2, 

the baghouse would be designed to 

lower the PM emissions to an emission 

rate of 0.012 lb/MMBtu.143 However, it 

has also been brought to EPA’s attention 

that Entergy White Bluff has since 

canceled the proceeding before the 

Arkansas Public Service Commission to 

obtain a declaratory order approving the 

installation of those controls. 

Furthermore, the State has not 

submitted to EPA a revision to the RH 

SIP EPA received on September 23, 

2008, August 3, 2010, and 

supplemented on September 7, 2011. As 

far as EPA is aware, the State has not 

adopted revisions to the Arkansas RH 

SIP with respect to BART for SO2 for 

Entergy White Bluff Units 1 and 2 based 

on the proceeding before the Arkansas 

Public Service Commission. Therefore, 

what is before EPA is the Arkansas RH 

SIP submitted to EPA on September 23, 

2008 August 3, 2010, and supplemented 

on September 7, 2011, which does not 

include installation of a dry scrubber 

and baghouse for control of SO2 at 

White Bluff Units 1 and 2. As explained 

elsewhere in our response to comments, 

the RHR states that the BART 

determinations are made on a 

individual pollutant specific basis and 

this analysis is separate from the BART 

determinations for other pollutants at 

the same source. Therefore, EPA 

disagrees that it should not take action 

on PM BART for White Bluff Units 1 

and 2 until the SO2 controls to meet 

BART are known. 

Our approval of the limit for direct 

PM emissions was based on the 

extremely low modeled visibility impact 

from these emissions. While reductions 

in PM may occur from future controls 

necessary to meet SO2 BART, these PM 

reductions are not necessary to meet 

BART for PM. 

Comment: The EPA’s BART 

Guidelines specify that BART should be 

evaluated and defined for both PM10

and PM2.5 (see 40 CFR part 51, appendix 

Y, section IV.A.). However, with the 

exception of the oil-firing scenario for 

Lake Catherine Unit 4, ADEQ did not 

adopt BART limits for PM2.5, yet EPA 

did not identify this as a deficiency. 

EPA must disapprove the PM/PM10

BART limits in the Arkansas RH SIP 

along with disapproving the RH SIP for 

the lack of BART limits for PM2.5. 

Response: The BART Guidelines do 

not specify that states must make BART 

determinations for PM2.5. The BART 

Guidelines provide the following: 

‘‘You must look at SO2, NOX, and direct 

particulate matter (PM) emissions in 

determining whether sources cause or 

contribute to visibility impairment, including 

both PM10 and PM2.5.’’ 144

This language in the BART Guidelines 

was meant to clarify that when a state 

is making a BART determination as to 

whether a source is subject to BART, the 

modeling evaluation to determine the 

source’s impact on visibility has to 

account for both PM10 and PM2.5

emissions. There are several instances 

in which we state in both the preamble 

to the RHR, and in the BART Guidelines 

that PM10 may be used as indicator for 

PM2.5 in determining whether a source 

is subject to BART. However, neither 

the RHR nor the BART Guideline 

specify that states must set separate 

BART limits for PM2.5. We have 

concluded that Arkansas’s PM BART 

determinations for the natural gas firing 

scenario for Entergy Lake Catherine Unit 

4; for the bituminous and subbituminous coal firing scenarios for 

Entergy White Bluff Units 1 and 2; for 

the AEP Flint Creek Boiler No. 1; and 

for the Domtar Ashdown Mill Power 

Boiler No. 1 are reasonable. 

Comment: The existing PM limit of 

0.1 lbs/MMBtu in the AEP Flint Creek 

Title V permit, which EPA proposed to 

approve as BART for PM, is based on 

EPA’s New Source Performance 

Standards (NSPS) for Fossil-Fuel Fired 

Steam Generators that commenced 

construction after August 17, 1971 (40 

CFR part 60, subpart D, § 60.42(a)(1)). 


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145These documents can be found in the docket 

associated with our final rulemaking. 

146 70 FR 39116. 

147 70 FR 39116. 

148 76 FR 52604 and 76 FR 80754. 

149 76 FR 16168 and 76 FR 81728. 

150See section IV, specific conditions 3.a., 8.a., 

and 17.b of the ADEQ Operating Air Permit for 

AEP–Flint Creek Power Plant (Permit No. 0276– 

AOP–R5). This permit can be viewed at http:// 

www.adeq.state.ar.us/ftproot/pub/WebDatabases/ 

PermitsOnline/Air/0276-AOP-R5.pdf. 

This PM emission limit does not apply 

during periods of startup, shutdown, 

and malfunction (SSM) (see 40 CFR 

60.8(c)); only applies to filterable PM 

emissions (see 40 CFR 60.46(b)(2) and 

EPA Method 5 in 40 CFR part 60, 

appendix A); and only applies during 

scenarios of firing coal and tire-derived 

fuel at Flint Creek (see Title V permit for 

Flint Creek, Permit No. 0276–AOP–R5, 

at 18 (Exhibit 3)). When the unit is firing 

coal with leachate injection a PM10

emission limit of 778.4 lb/hr applies, 

which at maximum heat input capacity 

equates to 0.12 lb/MMBtu. Since the 

Title V permit directs Flint Creek to ask 

EPA for a determination regarding the 

applicability of NSPS Subpart D limits 

for oil-firing and coal-and-oil-firing 

scenarios, it is not clear whether any PM 

emission limit applies to Flint Creek 

during oil-firing and oil-and-coal-firing. 

EPA recently proposed to disapprove 

SSM exemptions from BART limits in 

the Kansas RH SIP (see 76 FR 52604, 

52617–18 and section 302(k) of the 

CAA). Because BART must reflect the 

best system of continuous emission 

reduction, the BART limits must apply 

at all times. The existing PM limit in the 

Flint Creek Title V permit cannot satisfy 

BART because the existing PM limit in 

the Flint Creek Title V permit does not 

apply during SSM, and there does not 

appear to be a PM limit in the Flint 

Creek Title V permit during oil-firing 

and oil- and coal-firing. A proper BART 

evaluation would have shown that these 

limits do not reflect BART for Flint 

Creek’s PM emissions. 

Response: In our review of the 

Arkansas RH SIP, we evaluated the 

determination by ADEQ that no 

additional PM controls are required at 

the AEP Flint Creek Boiler No. 1. 

ADEQ’s determination was based on the 

pre-control modeling performed by 

ADEQ and on AEP SWEPCO’s statement 

that the PM visibility modeling did not 

‘‘trip the BART impact threshold.’’ We 

reviewed the pre-control modeling 

ADEQ performed using the 24-hr actual 

maximum emissions from the baseline 

period. The modeling results in 

Appendix 9.2B of the Arkansas RH SIP 

and presented in Table 7–6 of Appendix 

A of the TSD145 indicate that PM 

contributes less than 0.5% of the total 

visibility impacts from Flint Creek 

Boiler No. 1 at all nearby Class I areas 

with the exception of Upper Buffalo. PM 

contributions to visibility impacts at 

Upper Buffalo from Flint Creek are less 

than 2% of the total visibility 

impairment at this Class I area. On the 

most impacted day at Upper Buffalo, 

modeling the 24-hr actual maximum 

emissions demonstrates that PM 

contributes only 0.07 dv of the total 

3.781 dv modeled visibility impact from 

the source. Clearly, the most effective 

controls to address visibility 

impairment from the source are those 

that would reduce emissions of 

visibility impairing pollutants other 

than direct emissions of PM. In this 

action, we are finalizing our proposal to 

disapprove Arkansas’s NOX and SO2

BART determinations for Flint Creek 

Boiler No. 1, as ADEQ did not properly 

identify and evaluate NOX and SO2

controls to address visibility 

impairment from the source. 

As stated in our proposed rulemaking 

on the Arkansas RH SIP, we found that 

the source’s visibility impact from PM 

emissions alone is so minimal such that 

the installation of any additional PM 

controls on the source could only result 

in very small visibility benefit that 

would not justify any upgrades to the 

existing controls. This is in keeping 

with the BART Rule, which states the 

following: 

‘‘Consistent with the CAA and the 

implementing regulations, States can adopt a 

more streamlined approach to making BART 

determinations where appropriate. Although 

BART determinations are based on the 

totality of circumstances in a given situation, 

such as the distance of the source from a 

Class I area, the type and amount of pollutant 

at issue, and the availability and cost of 

controls, it is clear that in some situations, 

one or more factors will clearly suggest an 

outcome. Thus, for example, a State need not 

undertake an exhaustive analysis of a 

source’s impact on visibility resulting from 

relatively minor emissions of a pollutant 

where it is clear that controls would be costly 

and any improvements in visibility resulting 

from reductions in emissions of that 

pollutant would be negligible. In a scenario, 

for example, where a source emits thousands 

of tons of SO2 but less than one hundred tons 

of NOX, the State could easily conclude that 

requiring expensive controls to reduce NOX

would not be appropriate. In another 

situation, however, inexpensive NOX

controls might be available and a State might 

reasonably conclude that NOX controls were 

justified as a means to improve visibility 

despite the fact that the source emits less 

than one hundred tons of the pollutant.’’ 146

Therefore, we agreed with the State 

that PM BART for Flint Creek Boiler No. 

1 is the existing PM emission limit (i.e. 

no additional controls). The BART Rule 

provides that states may determine that 

for a given source no additional control 

satisfies the BART requirement for a 

particular pollutant.147 In our final 

approval of the Kansas RH SIP, we 

approved the State’s determination that 

no additional control (and no new 

emission limit) for PM is BART for a 

number of sources.148 In our final 

approval of the Oklahoma RH SIP, we 

also approved the State’s determination 

that no additional control (and no new 

emission limit) for PM is BART for a 

number of sources.149 In the above 

cases, Kansas and Oklahoma adopted no 

new PM emission limit for PM BART for 

particular sources, and EPA approved 

this based on the low visibility impact 

attributable to PM emissions. As such, 

it was not necessary for Arkansas to 

establish a new PM emission limit for 

BART for Flint Creek Boiler No. 1, as 

‘‘no additional controls’’ satisfies PM 

BART in this particular case. Since no 

additional controls satisfies BART for 

Flint Creek Boiler No. 1, it is not 

problematic that the existing PM 

emission limit that Arkansas adopted in 

Chapter 15 of APCEC Regulation No. 19 

as meeting PM BART for Flint Creek 

Boiler No. 1 (i.e. the EPA NSPS, and 

also included in the Title V permit) does 

not apply on a continuous basis and 

only applies to filterable PM emissions. 

We also clarify that the distinction 

between our approval of an existing PM 

emission limit adopted in Arkansas’s 

Chapter 15 of APCEC Regulation No. 19 

for Flint Creek Boiler No. 1 that does not 

apply during SSM and our disapproval 

of an exemption of SSM for BART in the 

Kansas RH SIP is that the BART 

determinations that would have 

exempted SSM in the Kansas RH SIP 

were not based upon the minimal 

visibility impact from a particular 

pollutant. Therefore, we are finalizing 

our proposed approval of Arkansas 

determination that PM BART is the 

existing PM emission limit in Chapter 

15 of APCEC Regulation No. 19 for Flint 

Creek Boiler No. 1. 

That being said, we note that the 0.1 

lb/MMBtu existing PM emission limit 

(for Flint Creek Boiler No. 1) in Chapter 

15 of APCEC Regulation No. 19, which 

is based on EPA’s NSPS standards (40 

CFR part 60, subpart D, § 60.42(a)(1)), 

applies during the following firing 

scenarios: coal firing; coal and tire 

derived fuel (TDF) firing; and during 

coal firing with leachate injection.150

We are finalizing our proposed approval 

of PM BART for the AEP Flint Creek 

Boiler No. 1. 

Comment: The existing PM limit of 

0.1 lbs/MMBtu in the Entergy White 


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14638 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

151 70 FR 39116. 

152 70 FR 39116. 

153 76 FR 52604 and 76 FR 80754. 

154 76 FR 16168 and 76 FR 81728. 

Bluff Title V permit, which EPA 

proposed to approve as BART for PM, 

is based on EPA’s NSPS for Fossil-Fuel 

Fired Steam Generators that commenced 

construction after August 17, 1971 (40 

CFR part 60, subpart D, § 60.42(a)(1)). 

This PM emission limit does not apply 

during SSM (see 40 CFR 60.8(c)), and 

only applies to filterable PM emissions 

(see 40 CFR 60.46(b)(2) and EPA 

Method 5 in 40 CFR part 60, appendix 

A). Since the Title V permit directs 

White Bluff to ask EPA for a 

determination regarding the 

applicability of NSPS Subpart D limits 

during fuel oil-firing and biodiesel firing 

during startup, shutdown and 

malfunction, it is not clear whether any 

PM emission limit applies to White 

Bluff for these scenarios. EPA recently 

proposed to disapprove SSM 

exemptions from BART limits in the 

Kansas RH SIP (see 76 FR 52604, 

52617–18 and section 302(k) of the 

CAA). Because BART must reflect the 

best system of continuous emission 

reduction, the BART limits must apply 

at all times. The existing PM limit in the 

White Bluff Title V permit cannot 

satisfy BART because this limit does not 

apply during SSM, and there does not 

appear to be a PM limit in the White 

Bluff Title V permit during fuel oilfiring and bio-diesel firing. The existing 

PM limit in the White Bluff Title V 

permit cannot satisfy BART because it 

does not apply during all periods of 

operation of the unit. 

Response: First, we disagree that we 

are approving the White Bluff Title V 

permit as BART for PM. We are 

approving the part of the Chapter 15 of 

APCEC Regulation No. 19 that applies to 

the Entergy White Bluff Units 1 and 2 

as BART for PM. We agree that the part 

of the submitted rule that applies to the 

two White Bluff units is based on EPA’s 

NSPS for Fossil-Fuel Fired Steam 

Generators that commenced 

construction after August 17, 1971 (40 

CFR part 60, subpart D, § 60.42(a)(1)). 

Secondly, in our review of the Arkansas 

RH SIP, we evaluated the determination 

by ADEQ that no additional PM controls 

are required at the Entergy White Bluff 

Units 1 and 2. We reviewed the data 

submitted by ADEQ, including precontrol modeling in Appendix 9.2B of 

the Arkansas RH SIP, to evaluate the 

State’s determination that the majority 

of visibility-causing emissions are due 

to emissions of NOX and SO2, and that 

no additional PM controls are 

warranted. The modeling results in 

Appendix 9.2B of the Arkansas RH SIP 

and presented in Table 7–7 of Appendix 

A of the TSD, indicate that PM 

contributes less than 0.4% of the total 

visibility impacts at all nearby Class I 

areas. On the most impacted day at 

Caney Creek, modeling the 24-hr actual 

maximum emissions, PM contributes 

only 0.03 dv of the more than 8 dv 

modeled visibility impact from the 

White Bluff Units 1 and 2. Clearly, the 

majority of visibility-causing emissions 

are due to emissions of NOX and SO2

and the most effective controls to 

address visibility impairment from the 

units are those that would reduce 

emissions of NOX and SO2 rather than 

direct emissions of PM. In this action, 

we are finalizing our proposal to 

disapprove Arkansas’s NOX and SO2

BART determinations for White Bluff 

Units 1 and 2, as the State did not 

properly evaluate and identify controls 

to address visibility impairment from 

these units. 

As articulated in our proposed 

rulemaking on the Arkansas RH SIP, we 

are finding that the source’s visibility 

impact from PM emissions alone is so 

minimal such that the installation of 

any additional PM controls on the two 

units could only result in such small 

visibility benefits that it could not 

justify any upgrades to the existing 

controls. This is in keeping with the 

BART Rule, which states the following: 

‘‘Consistent with the CAA and the 

implementing regulations, States can adopt a 

more streamlined approach to making BART 

determinations where appropriate. Although 

BART determinations are based on the 

totality of circumstances in a given situation, 

such as the distance of the source from a 

Class I area, the type and amount of pollutant 

at issue, and the availability and cost of 

controls, it is clear that in some situations, 

one or more factors will clearly suggest an 

outcome. Thus, for example, a State need not 

undertake an exhaustive analysis of a 

source’s impact on visibility resulting from 

relatively minor emissions of a pollutant 

where it is clear that controls would be costly 

and any improvements in visibility resulting 

from reductions in emissions of that 

pollutant would be negligible. In a scenario, 

for example, where a source emits thousands 

of tons of SO2 but less than one hundred tons 

of NOX, the State could easily conclude that 

requiring expensive controls to reduce NOX

would not be appropriate. In another 

situation, however, inexpensive NOX

controls might be available and a State might 

reasonably conclude that NOX controls were 

justified as a means to improve visibility 

despite the fact that the source emits less 

than one hundred tons of the pollutant.’’ 151

Therefore, we agree with the State 

that PM BART for White Bluff Units 1 

and 2 is the existing PM emission limit 

in Chapter 15 of APCEC Regulation No. 

19 (i.e. no additional controls). The 

BART Rule provides that states may 

determine that for a given source no 

additional control satisfies the BART 

requirement for a particular 

pollutant.152 In such cases, it is not 

necessary for a state to establish a new 

emission limit when no additional 

control is BART. In our final approval 

of the Kansas RH SIP, we approved the 

State’s determination that no additional 

control (and no new emission limit) for 

PM is BART for a number of sources.153

In our final approval of the Oklahoma 

RH SIP, we also approved the State’s 

determination that no additional control 

(and no new emission limit) for PM is 

BART for a number of sources.154 In the 

above cases, Kansas and Oklahoma 

adopted no new PM emission limit for 

PM BART for particular sources, and 

EPA approved this based on the low 

visibility impact attributable to PM 

emissions. As such, it was not necessary 

for Arkansas to establish a new PM 

emission limit for BART for White Bluff 

Units 1 and 2, as ‘‘no additional 

controls’’ satisfies PM BART in this 

particular case. As explained above, the 

distinction between our approval in the 

Arkansas RH SIP of an existing PM 

emission limit in Chapter 15 of APCEC 

Regulation No. 19 for White Bluff that 

does not apply during SSM and our 

disapproval of an exemption of SSM for 

BART in the Kansas RH SIP is that the 

BART determinations that would have 

exempted SSM in the Kansas RH SIP 

were not based upon the minimal 

visibility impact from a particular 

pollutant. Since no additional controls 

satisfies BART for White Bluff Units 1 

and 2, it is not problematic that the 

existing PM emission limit that 

Arkansas adopted for PM BART for 

Units 1 and 2 does not apply on a 

continuous basis and only applies to 

filterable PM emissions. Therefore, we 

are finalizing our proposed approval of 

Arkansas determination that PM BART 

is the existing PM emission limit in 

Chapter 15 of APCEC Regulation No. 19 

for White Bluff Units 1 and 2. 

Comment: The technology available 

for control of the pollutant in question 

is the first factor that must be evaluated 

in a BART analysis. The most effective 

PM control technology is a fabric filter 

baghouse. ESPs can achieve control 

efficiencies of 99% or better, and 

baghouses can achieve PM control 

efficiencies as high as 99.9% or even 

higher. Baghouses have been installed 

since the 1970’s and are the PM control 

technology of choice for new coal-fired 

EGUs. Several recent PSD permits have 

been issued with best available control 

technology (BACT) limits at 0.010 lb/ 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14639 

MMBtu, based on installation of a fabric 

filter baghouse. Matt Haber, EPA Region 

9’s BACT expert and current Deputy 

Director of the Air Division, concluded 

in 2002 that BACT for filterable PM at 

two existing PC boilers firing Powder 

River Basin coal and equipped with a 

baghouse was 0.006 lb/MMBtu based on 

a 3-hour average and monitored via EPA 

Method 5 and continuously using 

triboelectric broken bag detectors. Even 

though AEP Flint Creek and Entergy 

White Bluff are subject to BART, and 

not BACT, after evaluating the 

achievable emission rates with a new 

baghouse at these units, there is no 

reason why Flint Creek and White Bluff 

could not achieve PM emission rates 

similar to those of a new unit with a 

baghouse. Particularly since White Bluff 

will be installing new baghouses at the 

two units. Even these BACT limits fail 

to reflect the low levels of filterable PM 

emissions that can be achieved with 

fabric filter baghouses. As early as May 

2004, at least 147 performance tests 

measured filterable PM/PM10 at less 

than 0.010 lb/MMBtu and 82 recorded 

PM/PM10 emissions less than 0.005 lb/ 

MMBtu using fabric filter baghouses. 

The lowest reported PM/PM10 emission 

rate was 0.0004 lb/MMBtu. Other states 

have made PM BART determinations 

that are much lower than ADEQ’s 

proposed limit of 0.1 lb/MMBtu, based 

on use of a baghouse. South Dakota 

adopted and EPA recently approved a 

PM BART emission limit of 0.012 lb/ 

MMBtu for the Big Stone Power Plant, 

a 600 MW power plant burning Powder 

River Basin coal, and with an existing 

baghouse. Even though Big Stone is 

located 431 km from the nearest Class 

I area, EPA did not exempt the plant 

from PM BART as EPA has proposed for 

Flint Creek. 

Response: EPA agrees that baghouses 

have very high PM control efficiency 

capabilities. However, as articulated in 

our proposed rulemaking and further 

explained in our response to comments, 

due to the low visibility impact from the 

AEP Flint Creek Boiler No. 1 and the 

Entergy White Bluff Units 1 and 2 

attributable to PM, we agree with 

Arkansas that the existing PM emission 

limit adopted for these sources in 

Chapter 15 of APCEC Regulation No. 19 

satisfies BART for these units. As 

explained elsewhere in our response to 

comments, this is consistent with the 

BART Rule and EPA’s action on other 

states’ RH SIPs. We are finalizing our 

proposed approval of the existing PM 

emission limit as PM BART for the AEP 

Flint Creek Boiler No. 1 and Entergy 

White Bluff Units 1 and 2. 

With regard to the comment that 

White Bluff will be installing baghouses 

on Units 1 and 2, EPA is aware that 

Entergy White Bluff has canceled the 

proceeding before the Arkansas Public 

Service Commission to obtain a 

declaratory order approving the 

installation of these controls. 

Furthermore, as explained elsewhere in 

our response to other comments, the 

Arkansas RH SIP that is before EPA to 

act on does not include installation of 

a dry scrubber and baghouse for control 

of SO2 and PM emissions at White Bluff 

Units 1 and 2. Therefore, EPA disagrees 

that it should disapprove the PM BART 

determination for White Bluff Units 1 

and 2 because the source may be 

considering installing these controls. 

Comment: Coal-fired boilers with hotside ESPs, including the Navajo Power 

Plant Units, are meeting PM emission 

rates much lower than 0.1 lb/MMBtu. 

Even if EPA finds that it is acceptable 

to not evaluate additional control 

technologies for PM10 at AEP Flint 

Creek, the PM10 BART limit for Flint 

Creek must reflect the technology 

determined to represent BART. The 0.1 

lb/MMBtu PM emission limit of Subpart 

D of the NSPS does not. Because the 

existing PM emission limit of 0.1 lb/ 

MMBtu is much higher than the 

maximum 24-hour average PM10 levels 

emitted by Flint Creek, the existing limit 

fails to reflect the best system of 

continuous emission reduction as 

required by the definition of BART in 40 

CFR 51.302. There will be less incentive 

to properly operate and maintain the 

PM control equipment if the PM BART 

limit is unreasonably high. 

Response: As articulated in our 

proposed rulemaking and further 

explained in earlier response to 

comments, due to the low visibility 

impact from the AEP Flint Creek Boiler 

No. 1 attributable to PM, we agree with 

Arkansas that the existing PM emission 

limit in Chapter 15 of APCEC 

Regulation No. 19 satisfies BART for 

this unit. EPA agrees with Arkansas that 

requiring the source to install and 

operate additional PM controls on this 

unit (including any upgrades to the 

existing PM controls) would not be 

justified because of the low visibility 

benefit that would result. As explained 

elsewhere in our response to comments, 

this is consistent with the BART Rule 

and EPA’s action on other states’ RH 

SIPs. We are finalizing our proposed 

approval of the existing PM emission 

limit in as PM BART for the AEP Flint 

Creek Boiler No. 1. 

Comment: Even if it was determined 

that the existing ESPs represent BART 

for the White Bluff Units 1 and 2, the 

existing PM emissions limits fail to 

reflect BART. According to ADEQ, the 

maximum 24-hour actual PM10 emission 

rates at White Bluff Units 1 and 2 are 

much lower than the emissions allowed 

by the existing PM limit in the White 

Bluff Title V permit. At an emission rate 

of 0.1 lbs/MMBtu, while firing coal and 

a maximum allowable heat input 

capacity of 8,700 lbs/MMBtu, the 

maximum pound per hour emission rate 

would be 879 lb/hr. However, ADEQ 

modeled Entergy White Bluff’s highest24 hour actual PM10 emission rate as 

15.592 grams per second for Unit 1 and 

16.653 grams per second for Unit 2, 

which equate to 123.7 lb/hr and 132.2 

lb/hr, respectively. Assuming the 

highest actual PM10 emission rate 

occurred during the time of maximum 

heat input capacity, the maximum 24- 

hour actual PM10 emission rate modeled 

equates to 0.027 lb/MMBtu. In 2010, PM 

stack testing at White Bluff Units 1 and 

2 showed the units were emitting 

filterable PM and total PM at rates much 

lower than ADEQ’s PM BART limit of 

0.1 lb/MMBtu, which under Subpart D 

of the NSPS only applies to filterable 

PM (see Exhibits 14 and 15). With the 

installation of a scrubber and NOX

controls to meet BART, the condensable 

PM emissions will be even lower than 

the 2010 stack testing results show. 

Even if EPA finds it acceptable to not 

evaluate additional control technologies 

for PM at White Bluff Units 1 and 2, the 

PM BART limit for the units must 

reflect the technology determined to 

represent BART, which in this case it 

does not. Because the existing PM 

emission limit of 0.1 lb/MMBtu is much 

higher than the maximum 24-hour 

average PM10 levels emitted by White 

Bluff, the existing limit fails to reflect 

the best system of continuous emission 

reduction as required by the definition 

of BART in 40 CFR 51.302. There will 

be less incentive to properly operate and 

maintain the PM control equipment if 

the PM BART limit is unreasonably 

high. 

Response: As articulated in our 

proposed rulemaking and further 

explained in our previous response to 

comments, due to the low visibility 

impact from the Entergy White Bluff 

Units 1 and 2 attributable to PM, we 

agree with Arkansas that the existing 

PM emission limit adopted in Chapter 

15 of APCEC Regulation No. 19 satisfies 

BART for these units. EPA agrees with 

Arkansas that requiring the source to 

install and operate additional PM 

controls on these units (including any 

upgrades to the existing PM controls) is 

not justified based on the small 

visibility benefit. As explained 

elsewhere in our response to comments, 

this is consistent with the BART Rule 

and EPA’s action on other states’ RH 


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14640 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

155 70 FR 39116. 

156 70 FR 39116. 

157 76 FR 52604 and 76 FR 80754. 

158 76 FR 16168 and 76 FR 81728. 

SIPs. We are finalizing our proposed 

approval of the existing PM emission 

limit as PM BART for White Bluff Units 

1 and 2. 

Comment: Other states have made PM 

BART determinations that are much 

lower than ADEQ’s proposed limit of 

0.1 lb/MMBtu for White Bluff Units 1 

and 2. South Dakota adopted and EPA 

recently approved a PM BART emission 

limit of 0.012 lb/MMBtu for the Big 

Stone Power Plant, a 600 MW power 

plant burning Powder River Basin coal, 

and with an existing baghouse. Even 

though Big Stone is located 431 km from 

the nearest Class I area, neither South 

Dakota nor EPA exempt the plant from 

PM BART as EPA has proposed for 

White Bluff. In Big Stone’s case, South 

Dakota and EPA are following the 

Federal regulations regarding BART, 

which requires that sources that are 

subject to BART obtain BART limits for 

‘‘each pollutant emitted by’’ the BARTeligible source (see 40 CFR 51.301 and 

Appendix Y, section IV.A). The State of 

Wyoming has also adopted PM BART 

determinations for several EGUs that are 

lower than 0.1 lb/MMBtu, including 

0.042 lb/MMBtu for Naughton Unit 1; 

0.054 lb/MMBtu for Naughton Unit 2; 

0.015 lb/MMBtu for Naughton Unit 3, 

Dave Johnson Units 3 and 4, and 

Wyodak; and 0.03 lb/MMBtu for Jim 

Bridger Units 1–4. 

Response: The EPA agrees that other 

states have adopted PM emission limits 

more stringent than those adopted by 

Arkansas for PM BART. However, as 

articulated in our proposed rulemaking 

and further explained in our response to 

comments, due to the low visibility 

impact from White Bluff Units 1 and 2 

attributable to PM, we agree with 

Arkansas that the existing PM emission 

limit in Chapter 15 of APCEC 

Regulation No.19 satisfies BART for 

these units. EPA agrees with Arkansas 

that requiring the source to install and 

operate additional PM controls on these 

units (including any upgrades to the 

existing PM controls) is not justified 

based on the small visibility benefit. 

Such was not the case with regard to the 

visibility impact due to direct PM 

emissions from the sources in other 

states referenced in the comment. As 

explained elsewhere in our response to 

comments, this is consistent with the 

BART Rule and EPA’s action on other 

states’ RH SIPs. We are finalizing our 

proposed approval of the existing PM 

emission limit as PM BART for Entergy 

White Bluff Units 1 and 2. 

Comment: The EPA proposed to 

approve Entergy’s determination that 

PM BART for the natural gas firing 

scenario is the existing PM limit for 

Lake Catherine Unit 4, or 45.0 lb/hr (76 

FR 64204). EPA identifies the PM 

emission limit as 45.0 lb/hr, but the 

permit identifies the PM10 limit as 44.5 

lb/hr (see Exhibit 21). EPA cannot 

approve the existing PM limit as 

meeting BART for Lake Catherine Unit 

4 for the natural gas firing scenario 

because Lake Catherine’s Title V permit 

does not include provisions to ensure 

the enforceability of the PM limit. There 

are no requirements in the permit for 

testing to determine compliance with 

this limit. The permit states that 

Condition 9, which is a requirement to 

install and maintain O2 monitors and to 

maintain a positive O2 reading when the 

boilers are operating, is to be used for 

compliance with the PM10 and PM 

limits of the permit for Lake Catherine 

Unit 4 (see Exhibit 21). It is not clear 

how this will ensure compliance with 

the numerical PM10 emission limit of 

44.5 lb/hr. The provisions of Condition 

9 appear to be operational standards, 

and if ADEQ was relying on the O2

monitoring provision to meet BART for 

PM, the State would need to show that 

the operational standard will ensure 

equivalent results to the lb/hr emission 

limit assumed for BART (see 40 CFR 

51.308(e)(1)(iii)). EPA cannot justify its 

approval of the unenforceable PM/PM10

limit for Lake Catherine Unit 4 based on 

its statement that PM emissions are 

expected to be very low from natural gas 

firing. Once a unit is determined to be 

subject to BART, it must make a 

determination of BART for each 

pollutant emitted by the unit. 

Response: In our review of the 

Arkansas RH SIP, we evaluated the 

determination by ADEQ that PM 

emissions from Entergy’s Lake Catherine 

Unit 4 are inherently very low when 

burning natural gas and that as a result, 

no additional PM controls are required 

for the natural gas firing scenario. We 

agree with the State’s conclusion, based 

on its modeling results, that the 

visibility impact of this unit from direct 

PM emissions alone is minimal. We 

note that the modeling results submitted 

by Arkansas in Appendix 9.2B of the 

Arkansas RH SIP indicate that under 

natural gas firing conditions, NOX

contributes over 99.9% of Lake 

Catherine Unit 4’s total visibility 

impacts at all nearby Class I areas on the 

most impacted days. Based on the 

State’s modeling results, the visibility 

impact of this unit from direct PM 

emissions alone is so minimal such that 

the requirement of any additional PM 

controls on this unit would only achieve 

minimal visibility benefit and would 

not be justified. It is clear that the most 

effective controls to address visibility 

impairment from the source during 

natural gas firing are those that would 

reduce emissions of NOX. Given these 

conclusions, we proposed to find that 

the State reasonably concluded that 

BART for PM for the natural gas firing 

scenario is the existing PM emission 

limit for Unit 4 in Chapter 15 of APCEC 

Regulation No. 19. This is consistent 

with the BART Rule, which states the 

following: 

‘‘Consistent with the CAA and the 

implementing regulations, States can adopt a 

more streamlined approach to making BART 

determinations where appropriate. Although 

BART determinations are based on the 

totality of circumstances in a given situation, 

such as the distance of the source from a 

Class I area, the type and amount of pollutant 

at issue, and the availability and cost of 

controls, it is clear that in some situations, 

one or more factors will clearly suggest an 

outcome. Thus, for example, a State need not 

undertake an exhaustive analysis of a 

source’s impact on visibility resulting from 

relatively minor emissions of a pollutant 

where it is clear that controls would be costly 

and any improvements in visibility resulting 

from reductions in emissions of that 

pollutant would be negligible. In a scenario, 

for example, where a source emits thousands 

of tons of SO2 but less than one hundred tons 

of NOX, the State could easily conclude that 

requiring expensive controls to reduce NOX

would not be appropriate.’’ 155

Based on our analysis of the data 

submitted by ADEQ in the Arkansas RH 

SIP, and our agreement that PM 

emissions from burning natural gas are 

inherently very low, we agree with the 

State that PM BART for Lake Catherine 

Unit 4 is the existing PM emission limit 

in Chapter 15 of APCEC Regulation No. 

19 (i.e. no additional controls). The 

BART Rule provides that states may 

determine that for a given source no 

additional control satisfies the BART 

requirement for a particular 

pollutant.156 In such cases, it is not 

necessary for a state to establish a new 

emission limit when no additional 

control is BART. In our final approval 

of the Kansas RH SIP, we approved the 

State’s determination that no additional 

control (and no new emission limit) for 

PM is BART for a number of sources.157

In our final approval of the Oklahoma 

RH SIP, we also approved the State’s 

determination that no additional control 

(and no new emission limit) for PM is 

BART for a number of sources.158 In the 

above cases, Kansas and Oklahoma 

adopted no new PM emission limit for 

PM BART for particular sources, and 

EPA approved this based on the low 

visibility impact attributable to PM 

emissions. Arkansas adopted the 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14641 

159Compilation of Air Pollutant Emission Factors, 

Volume I: Stationary Point and Area Sources, AP– 

42, 5th Edition, January 1995. 

160EPA’s AP–42 emission factors are based on an 

average natural gas higher heating value of 1,020 

Btu/standard cubic foot. As explained under Table 

1.4–2 of EPA’s AP–42 emission factors, to convert 

from 1b/106 standard cubic feet to lb/MMBtu, 

divide by 1,020. Based on this calculation, the 7.6 

lb/106 standard cubic feet emission factor from 

combustion of natural gas is equivalent to an 

emission rate of 0.0074 lb/MMBtu. 

161The Arkansas RH SIP was originally submitted 

to EPA on September 23, 2008. We received a 

revision to the RH SIP on August 3, 2010, and a 

supplemental submittal on September 27, 2011. The 

revisions to Chapter 15 of APCEC Regulation 19 

that we are referring to were submitted to us in the 

August 3, 2010 RH SIP revisions. 

162Appendix Y to Part 51, section IV.4. 

existing PM emission limit from the 

facility’s existing permit as BART for 

Lake Catherine Unit 4, which is 

consistent with the finding that ‘‘no 

additional controls’’ is sufficient to 

satisfy PM BART in this particular case. 

With regard to the commenter’s 

concerns about the enforceability of the 

limit, because of the extremely low 

visibility impact of direct PM emissions 

from this source and the inherently low 

emissions of PM from natural gas 

combustion, the practical enforceability 

of this limit is not critical to our 

approval. We also note that NOX

contributes over 99.9% of Lake 

Catherine Unit 4’s total visibility 

impacts at all nearby Class I areas on the 

most impacted days. Therefore, we are 

finalizing our proposed approval of 

Arkansas’s determination that PM BART 

is the existing PM emission limit in 

Chapter 15 of APCEC Regulation No. 19 

for the Entergy Lake Catherine Unit 4. 

A review of the emissions based on 

AP–42 emissions factors substantiates 

that the PM emissions from natural gas 

combustion are inherently low. Table 

1.4–2 of EPA’s AP–42 Compilation of 

Air Pollutant Emission Factors 159

indicates the total PM (i.e. condensable 

plus filterable PM) emission factor from 

combustion of natural gas is 7.6 lb/106

standard cubic feet, which is equivalent 

to an emission rate of 0.0074 lb/ 

MMBtu.160 A unit’s maximum emission 

rate for a given pollutant can be 

calculated by using the following 

standard equation: 

Pollutant mass emission rate (lb/hr) = 

Pollutant emission rate (lb/MMBtu) 

x Unit heat input rate (MMBtu/hr) 

Accordingly, Appendix 9.1A of the 

Arkansas RH SIP indicates that the Lake 

Catherine Unit 4 has a heat input rate 

of 5,850 MMBtu/hr. Based on Unit 4’s 

heat input rate and the 0.0074 lb/ 

MMBtu PM emission rate from natural 

gas combustion, the unit’s maximum 

mass emission rate for PM is 43.29 lb/ 

hr. This is actually slightly lower than 

the existing PM emission limit for 

Entergy Lake Catherine Unit 4 as of 

October 15, 2007 (i.e. 45 lb/hr). 

With regard to the comment that the 

Entergy Whit Bluff Title V permit 

identifies the PM10 limit as 44.5 lb/hr, 

EPA is approving the part of Chapter 15 

of APCEC Regulation No. 19 161 that 

establishes PM BART for the natural gas 

firing scenario for Entergy Lake 

Catherine Unit 4. The Title V permit 

that was in effect at the time of the 

State’s adoption of Chapter 15, 

Regulation 19, which is Permit No. 

1717–AOP–R4, required Unit 4 to meet 

a PM emission limit of 45 lb/hr. The 

Title V permit referenced by the 

commenter is Permit No. 1717–AOP– 

R5, and appears to contain revisions to 

several emission limits, including the 

PM emission limit for Unit 4. However, 

EPA can act only upon what is 

submitted to it by a state as a SIP 

revision. Arkansas submitted Chapter 

15, Regulation 19 as part of its RH SIP 

revision. The State’s submitted RH Rule 

adopts the existing PM emission limit as 

of October 15, 2007 (i.e. 45 lb/hr) as the 

PM BART emission limit. 

The EPA is finalizing its approval of 

the existing PM emission limit as 

meeting PM BART for Entergy Lake 

Catherine Unit 4 for the natural gas 

firing scenario. 

4. Comments on the Capacity Factor 

Used in the State’s BART Analyses for 

Entergy Lake Catherine and White Bluff 

Comment: The EPA was incorrect in 

its assessment of Entergy’s Lake 

Catherine BART determination that 

Entergy’s Lake Catherine Unit 4 

assumption of a 10% capacity unit 

needs to be supported by an enforceable 

limit. A 10% capacity factor for 

Catherine Unit 4 is a conservative 

assumption as demonstrated by the 

following table: 

LAKE CATHERINE UNIT 4 ANNUAL CAPACITY FACTOR

2003 2004 2005 2006 2007 2008 2009 2010 2011 

(1/1–11/31) 

10.4 3.2 4.2 0.5 0.7 2.7 3.0 3.1 2.5 

This is consistent with the BART 

Guidelines because the baseline 

emissions rate represents a realistic 

depiction of anticipated annual 

emissions for the source and actual 

emissions for existing sources subject to 

BART should be based from a baseline 

period by the state. The BART 

Guidelines provide that only if future 

operating parameters differ from past 

practices and they have a deciding effect 

in the BART determination, then these 

parameters need to be enforceable 

limits. Consistent with the BART 

Guidelines, annual emissions for 

Entergy Lake Catherine Unit 4 were 

estimated based on the continuation of 

past practice of using 10% capacity for 

future emissions. Therefore, an 

enforceable permit limitation is not 

required for a 10% capacity use of 

Entergy Lake Catherine Unit 4. 

Response: The EPA agrees that in our 

proposed rulemaking on the Arkansas 

RH SIP we made an error in our 

calculation of the capacity factor for 

recent years for Entergy Lake Catherine 

Unit 4. Based on certain statements 

made in the BART analysis for Lake 

Catherine, to the effect that in the future 

the unit was expected to be dispatched 

approximately 10% of the time only, we 

were under the impression that the 

source had factored into their cost 

analysis that the unit would only be 

operating 10% of the time when the unit 

has historically operated at considerably 

more than 10% of the time. Based on 

the information provided by the 

commenter, we agree that the source has 

historically operated at less than a 10% 

capacity factor. We also agree that the 

BART Guidelines provide that for the 

purpose of calculating the cost of 

controls, the state may calculate 

baseline emissions based upon 

continuation of past practice.162

However, our finding that the State 

did not properly document the cost 

analysis for NOX controls for the fuel 

and gas firing scenarios and SO2 and PM 

controls for the fuel oil firing scenario 

for Lake Catherine Unit 4 has not 

changed, as the proper documentation 

necessary to allow us to make an 

informed and proper evaluation of the 

BART analysis was not included in the 

SIP, as the BART Guidelines require. As 

explained in our proposed rulemaking, 

the RH SIP includes the results of a 


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14642 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

163EPRI document entitled ‘‘Retrofit NOX Control 

Guidelines for Gas and Fired Boilers,’’ Version 2, 

June 1997. 164See Appendix 9.3B of the RH SIP. 

165Appendix Y to Part 51, section IV.4. 166See Tables 9.4f and 9.4e of the Arkansas RH 

SIP. The pre- and post-control visibility impact 

reported is the maximum Ddv. The post-control 

visibility impact is the visibility impact resulting 

from the BART controls adopted by the State. 

computerized model the source used to 

calculate the costs associated with each 

NOX control technology for both the 

natural gas and fuel oil firing scenarios. 

However, the SIP includes no detailed 

breakdown of the costs. The only 

explanation of the computerized model 

is a paragraph in Appendix 9.3B, which 

points out that inputs that went into the 

model were based on inputs derived 

from the EPRI document entitled 

‘‘Retrofit NOX Control Guidelines for 

Gas and Oil Fired Boilers,’’ 163 which 

were further analyzed to reflect 

performance expected for Lake 

Catherine Unit 4, as according to the 

source ‘‘each specific boiler will 

perform differently due to the unique 

characteristics of that boiler.’’ 164 The 

BART Guidelines provide that states 

should include documentation for any 

additional information used for the cost 

calculations, including any information 

supplied by vendors that affects your 

assumptions regarding purchased 

equipment costs, equipment life, and 

other elements of the calculation.165

This was not done in the Arkansas RH 

SIP. 

Furthermore, as noted in our 

proposed rulemaking on the Arkansas 

RH SIP, the State did not properly 

consider NOX post-combustion controls 

in the BART analysis for natural gas 

firing and fuel oil firing. As pointed out 

by another comment, the State 

eliminated post-combustion controls 

from consideration because they were 

found to be not cost-effective and the 

State eliminated two NOX control 

options (for natural gas firing) involving 

a combination of combustion controls 

because of their incremental costeffectiveness. Based on the information 

provided from the source’s 

computerized model, the costeffectiveness of a combination of 

combustion controls and SNCR is 

$3,378/NOX ton removed for the natural 

gas firing scenario and $3,440/NOX ton 

removed for the fuel oil firing scenario. 

This is not an unreasonably high costeffectiveness value, and depending on 

the visibility impact of these controls 

and the consideration of any of the other 

statutory factors, the State may find that 

these controls are BART. In light of 

Entergy Lake Catherine’s pre-control 

visibility impact of 6.607 dv and postcontrol visibility impact of 3.671 dv at 

Caney Creek for the fuel oil firing 

scenario, which is based on the BART 

controls adopted by the State in Chapter 

15, Regulation 19 (i.e. for NOX BART 

this consists of boiler tuning, boiler 

modifications, and burners out of 

service), we believe that it is possible 

that NOX and SO2 controls more 

stringent than those adopted by the 

State, including post-combustion 

controls, would be cost-effective and 

help reduce the visibility impact of the 

source at Arkansas and Missouri Class 

I areas. Therefore, the State should have 

evaluated both the cost-effectiveness 

and the incremental cost-effectiveness 

in addition to the visibility impact of 

post-combustion controls and each of 

the other control options considered at 

each potentially affected Class I area 

before eliminating any given control 

option. It appears that the source and 

the State may have only considered the 

incremental cost-effectiveness of 

controls in eliminating post-combustion 

controls and all other controls more 

stringent than the controls adopted by 

the State for NOX BART. The BART 

Guidelines provide that average costeffectiveness (reported by the source to 

be $1,701/ton NOX removed and $3,757/ 

ton NOX removed for the two sets of 

combination of controls mentioned 

above for the natural gas firing 

scenario), in addition to the visibility 

impacts at each potentially affected 

Class I area, should also be taken into 

consideration before a BART 

determination is made. 

In addition, as articulated in our 

proposed rulemaking on the Arkansas 

RH SIP, the State did not consider SO2

post-combustion controls in the BART 

analysis for fuel oil firing. Furthermore, 

as noted in our proposed rulemaking, 

the use of a wet scrubber system that 

controls both SO2 and PM emissions 

may prove to be cost-effective and 

provide for substantial visibility 

improvement. As explained elsewhere 

in our response to comments, in light of 

Entergy Lake Catherine’s pre-control 

visibility impact of 6.607 dv and postcontrol visibility impact of 3.671 dv at 

Caney Creek for the fuel oil firing 

scenario,166 we believe that it is possible 

that NOX, SO2, and PM controls more 

stringent than those adopted by the 

State in Chapter 15 of APCEC 

Regulation No. 19, including postcombustion controls, would be costeffective and help reduce the visibility 

impact of the source at Arkansas and 

Missouri Class I areas. 

Therefore, we are finalizing our 

proposed disapproval of BART for the 

Entergy Lake Catherine Unit 4 for NOX

for both the natural gas and fuel oil 

firing scenarios, and SO2 and PM for the 

fuel oil firing scenario. 

Comment: The EPA was incorrect in 

criticizing the cost-analysis conducted 

for Entergy’s White Bluff Units 1 and 2 

because the source assumed 85% 

utilization of the units without an 

enforceable limit when the EPA believes 

that the units are capable of utilization 

of 100% capacity factor. Utilization of 

85% capacity factor for these units is a 

conservative assumption, as 

demonstrated by the following table: 

WHITE BLUFF CAPACITY FACTORS

Unit 2003 2004 2005 2006 2007 2008 2009 2010 2011 

(1/1–11/31) 

1 ........................................................................... 75.3 73.4 63.1 55.1 81.3 78.2 71.1 82.5 60.7 

2 ........................................................................... 58.7 74.4 63.0 74.8 54.3 71.5 74.6 65.5 71.9 

This is consistent with the BART 

Guidelines because the baseline 

emissions rate represents a realistic 

depiction of anticipated annual 

emissions for the source and actual 

emissions for existing sources subject to 

BART should be based from a baseline 

period by the state. The Guidelines 

provide that only if future operating 

parameters differ from past practices 

and they have a deciding effect in the 

BART determination, then these 

parameters need to be enforceable 

limits. Consistent with the Guidelines, 

annual emissions from Entergy White 

Bluff Units 1 and 2 were estimated 

based on the continuation of past 

practice of using 85% capacity for 

future emissions. Therefore, an 

enforceable permit limitation is not 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14643 

167Appendix Y to Part 51, section IV.4. 

168 70 FR 39127. 

169Appendix Y to Part 51, section IV.4. 

170Appendix Y to Part 51, section IV.4. 

required for an 85% capacity use of 

Entergy White Bluff Units 1 and 2. 

Response: The EPA agrees that in our 

proposed rulemaking on the Arkansas 

RH SIP we made an error in our 

calculation of the capacity factor for 

recent years for Entergy White Bluff 

Units 1 and 2. Based on certain 

statements made in the BART analysis 

for White Bluff, to the effect that in the 

future the unit was expected to be 

dispatched approximately 85% of the 

time only, we were under the 

impression that the source had factored 

into their cost analysis that the unit 

would only be operating 85% of the 

time when the unit has historically 

operated at more than this. Based on the 

information provided the commenter, 

we agree that the source has historically 

operated at slightly less than an 85% 

capacity factor. We also agree that the 

BART Guidelines provide that for the 

purpose of calculating the cost of 

controls, the state may calculate 

baseline emissions based upon 

continuation of past practice.167

However, our finding that the State 

did not properly document the cost 

analysis for NOX and SO2 controls for 

both the bituminous and subbituminous coal firing scenarios for 

White Bluff Units 1 and 2 has not 

changed. As articulated in our proposed 

rulemaking, the proper documentation 

necessary to allow an informed and 

proper evaluation of the BART analysis 

was not included in the SIP, as the 

BART Guidelines require. As pointed 

out in another comment, the annual cost 

estimates of NOX combustion controls 

in the BART analysis for White Bluff 

Units 1 and 2 are significantly higher 

than those of similar controls at 

comparable facilities. The State must 

provide documentation of its cost 

calculations and a reasonably detailed 

breakdown of the costs. The State must 

also document the reason for any 

unusually high costs, which may 

require a higher level of detail in cost 

breakdown. Furthermore, the State did 

not properly consider the available 

controls and cost of controls because it 

did not evaluate SO2 and NOX controls 

that can achieve emission limits more 

stringent than the presumptive emission 

limits. As articulated in more detail in 

our proposed rulemaking, some of the 

control technologies evaluated by the 

State for SO2 are capable of achieving a 

higher control efficiency than that 

evaluated by the State, and there are 

NOX control technologies capable of 

achieving a more stringent limit than 

the presumptive limit. Because such 

controls have been found to be costeffective at similar facilities, the State 

must evaluate the costs and visibility 

impact of these controls before making 

a BART determination. Moreover, as 

articulated in our proposed rulemaking 

and in previous response to comments, 

the RHR, BART Guidelines, and CAA 

require that states consider the controls 

available, including the most stringent 

control technology, as well as the 

maximum level of control achievable by 

each technology. 

Therefore, we are finalizing our 

proposed disapproval of the NOX and 

SO2 BART determinations for the 

Entergy White Bluff Units 1 and 2 for 

both the bituminous and subbituminous coal firing scenarios. 

5. Comments on the State’s Cost 

Evaluations 

Comment: The ‘‘cost of compliance’’ 

is a BART consideration factor that 

should be properly left to the states and 

EPA cannot void a state’s cost 

assessment on the grounds that EPA 

would have used a different analysis or 

would have reached a different 

conclusion if it had primary 

jurisdiction. 

Response: The EPA agrees that the 

BART Rule provides states with some 

flexibility in how they calculate and 

consider costs.168 However, our grounds 

for disapproving Arkansas’s NOX BART 

determinations (natural gas and fuel oil 

firing conditions) and SO2 BART 

determination (fuel oil firing conditions) 

for Entergy Lake Catherine Unit 4 and 

the NOX and SO2 BART determinations 

(bituminous and sub-bituminous coal 

firing conditions) for Entergy White 

Bluff Units 1 and 2, as articulated in our 

proposal, are not based on EPA arriving 

at a different BART determination. Our 

disapproval of the above BART 

determinations is based in part on the 

fact that the State did not provide the 

proper documentation, as required by 

the BART Guidelines.169 The BART 

Guidelines provide that states must 

develop estimates of capital and annual 

costs and document the basis for 

equipment cost estimates either with 

data supplied by a vendor (i.e. budget 

estimates or bids) or by a referenced 

source (such as the OAQPS Control Cost 

Manual).170 The BART Guidelines also 

provide that cost estimates should be 

based on the OAQPS Control Cost 

Manual, where possible, to maintain 

and improve consistency, and that states 

should include documentation for any 

additional information used in cost 

calculation. The State did not satisfy 

this requirement in the above BART 

determinations because the State 

provided no documentation, 

breakdown, or any sufficiently detailed 

supporting information for its cost 

analyses. Without the documentation, 

neither we nor the public have the basis 

to verify the validity of either the cost 

estimates or Entergy’s BART 

determination based on the cost 

estimation. As pointed out in another 

comment, the annual cost estimates of 

NOX combustion controls in the State’s 

BART analysis for White Bluff Units 1 

and 2 are significantly higher than those 

of similar controls at comparable 

facilities. In summary, our disapproval 

for these BART determinations is based 

(among other reasons) on the fact that 

the proper documentation necessary to 

allow us to make an informed and 

proper evaluation of the BART analysis 

was not included in the SIP, as the 

BART Guidelines require. 

Comment: The EPA claims that 

Arkansas’s BART determinations should 

be disapproved because they rely on 

cost estimates that are not adequately 

documented or that lack sufficiently 

detailed supporting information (76 FR 

64206), yet EPA fails to provide any 

specific discussion in the proposed 

rule’s preamble of the purported 

shortcomings in the state’s cost 

information and fails to describe the 

type or degree of documentation it 

believes is mandated. In other similar 

RH SIP rulemakings, EPA has described 

a level of cost estimate documentation 

that is of such an extensive and detailed 

nature that it cannot be reasonably 

deemed an appropriate requirement of a 

BART cost assessment (76 FR 52388, 

52396). 

Response: The EPA disagrees that our 

proposed rulemaking did not provide 

any specific discussion on the type or 

degree of documentation needed in a 

state’s cost evaluation. Our proposed 

rulemaking and the TSD for our 

proposed rulemaking both specify that 

the basis for equipment cost estimates 

should be documented either with data 

supplied by an equipment vendor or by 

a referenced source, such as the OAQPS 

Control Cost Manual. Our proposed 

rulemaking also specified that for the 

SO2 BART analysis for fuel oil firing for 

Entergy Lake Catherine Unit 4, the State 

should clearly indicate the quantity of 

fuel oil consumption on which the 

State’s annual cost calculation is based. 

However, the BART Guidelines set 

specific requirements regarding this 

matter. The BART Guidelines provide 

that states should base their cost 

estimates on the OAQPS Control Cost 

Manual, where possible, and that the 

level of detail in the Cost Control 


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14644 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

171 76 FR 52388. 

172Appendix Y to Part 51, section IV.4. 

Manual addresses most control 

technologies in sufficient detail for a 

BART analysis. In general, a state 

should include a reasonably detailed 

line by line breakdown of the cost 

estimates, and document the vendor 

and/or referenced source. However, as 

explained in the BART Guidelines, 

where unusual costs due to site-specific 

design or other conditions are factored 

into the cost calculation, this should 

also be documented properly. For cases 

involving unusual costs, such as was the 

case at the San Juan Generating Station 

in New Mexico,171 which was subject to 

a FIP for BART controls (which the 

comment references), a higher level of 

detail in documentation may be 

necessary. Furthermore, the State is 

encouraged to work with EPA to 

determine the appropriate level of detail 

needed for any future BART analyses to 

be submitted to EPA as SIP revisions. 

Comment: The EPA found that 

Entergy’s cost evaluation for BART for 

NOX and SO2 for White Bluff Units 1 

and 2 was deficient because the 

company assumed 85% utilization of 

the two units when they are not subject 

to any federally enforceable limit on 

utilization, and the units are capable of 

100% utilization. We agree with EPA’s 

concerns that by assuming 85% 

utilization of the White Bluff units 

under the proposed NOX and SO2 BART 

limits, Entergy underestimated the tons 

of NOX and SO2 emissions that would 

be reduced and overestimated the costs 

per ton of pollutant removed for the 

combustion controls evaluated. The 

EPA also found that the cost analysis is 

inadequate because Entergy did not take 

into account the achievable emissions 

reductions with the control technologies 

evaluated. We agree with EPA’s finding 

that Entergy did not adequately evaluate 

the cost-effectiveness of controls in the 

NOX and SO2 BART analyses for White 

Bluff Units 1 and 2. 

Response: Based on comments 

received during the public comment 

period, it has come to our attention that 

we made an error in the calculation of 

the capacity factors for White Bluff 

Units 1 and 2. Based on the information 

provided, we agree that the source has 

historically operated at a slightly less 

than 85% capacity factor. The BART 

Guidelines provide that for the purpose 

of calculating the cost of controls, the 

state may calculate baseline emissions 

based upon continuation of past 

practice.172 However, our finding that 

the State did not properly document the 

cost analysis for NOX and SO2 controls 

for White Bluff Units 1 and 2 has not 

changed, as the proper documentation 

necessary to allow us to make an 

informed and proper evaluation of the 

BART analysis was not included in the 

SIP, as the BART Guidelines require. As 

pointed out in another comment, the 

annual cost estimates of NOX

combustion controls in the BART 

analysis for White Bluff Units 1 and 2 

are significantly higher than those of 

similar controls at comparable facilities. 

In addition, the State did not properly 

consider the available controls and cost 

of controls because it did not evaluate 

SO2 and NOX controls to achieve 

emissions limits more stringent than the 

presumptive emission limits. As 

articulated in more detail in our 

proposed rulemaking, some of the 

control technologies evaluated by the 

State for SO2 are capable of achieving a 

higher control efficiency than that 

evaluated by the State, and there are 

NOX control technologies capable of 

achieving a more stringent limit than 

the presumptive limit. Because such 

controls have been found to be costeffective at similar facilities, the State 

must evaluate the costs and visibility 

impact of these controls in making a 

BART determination. Furthermore, as 

articulated in our proposed rulemaking 

and in previous response to comments, 

the RHR, BART Guidelines, and CAA 

require that states consider the most 

stringent control technology, as well as 

the maximum level of control 

achievable by each technology. 

Comment: Comparing Entergy’s stated 

costs for SO2 controls with those found 

in other companies’ SO2 BART 

evaluations, it appears that Entergy has 

overstated the costs of SO2 controls. 

Entergy assumes much higher cost 

numbers for SO2 controls in its revised 

2008 BART analysis for White Bluff 

than in its 2006 BART analysis (see 

Exhibit 11). The SO2 control cost 

numbers in Entergy’s revised 2008 

BART analysis for White Bluff are much 

higher than the cost numbers in other 

plants’ SO2 BART analyses (see Exhibit 

17). Even though Entergy’s revised 2008 

BART analysis for White Bluff is not 

before EPA for approval, these 

comments are being provided now in 

case the revised 2008 BART analysis is 

eventually submitted to EPA. EPA 

should require that Entergy’s costeffectiveness calculations are based on 

the emission reductions achievable with 

the controls being evaluated and that 

Entergy’s cost-analysis is welldocumented, sound, and that the 

documentation and details be made 

publicly available. 

Response: The EPA agrees that the 

2008 BART analysis for Entergy White 

Bluff is not before EPA to take action on. 

As far as EPA is aware, the State has not 

revised the RH SIP to include Entergy 

White Bluff’s revised analysis. As such, 

it is unclear whether the State plans to 

submit it to EPA in the future as a SIP 

revision. However, we do agree that the 

cost numbers in the 2008 analysis are 

considerably higher than those in the 

2006 BART analysis that is before EPA 

to take action on. Consistent with the 

action we are taking on the Arkansas RH 

SIP in this rulemaking, if the State 

submits the revised 2008 BART analysis 

to EPA in the future in the context of an 

official RH SIP revision, the State must 

provide documentation of its cost 

calculations and a reasonably detailed 

breakdown of the costs. The State will 

also have to document the reason for 

any unusually high costs, which may 

require a higher level of detail in cost 

breakdown. If the State anticipates 

submitting a revised BART analysis for 

White Bluff or any other source to EPA 

as a SIP revision, EPA encourages the 

State to work with us to resolve any 

uncertainties it may have with regard to 

the level of detail needed in the cost 

analysis. Consistent with the action we 

are taking on the Arkansas RH SIP in 

this rulemaking, we agree that the State 

must ensure that its BART analyses 

evaluate the most stringent emission 

limit achievable by each control 

considered, and that the cost-analysis be 

well-documented, sound, and that the 

documentation and all other relevant 

details are made publicly available. 

Comment: It appears that the annual 

cost estimates of NOX combustion 

controls in Entergy’s December 2006 

BART analysis for the Entergy White 

Bluff Units 1 and 2 are very high ($5.2 

million for Unit 1 and $5.3 million for 

Unit 2) compared to the cost estimates 

for similar controls at other coal-fired 

EGUs, such as those at the Boardman 

Power Plant (617 MW, $3.7 million), the 

Four Corners Power Plant (790 MW, 

$3.0 million), and the Sherburne County 

Power Plant (690 MW, $2.2 million) (see 

Exhibit 19). Since neither Entergy nor 

ADEQ have provided the specific details 

that went into these cost estimates, it is 

difficult to discern why Entergy’s cost 

estimates are much higher. 

Response: The EPA agrees with the 

comment that the cost estimates 

Arkansas provided in the cost 

evaluation of NOX combustion controls 

in the 2006 Entergy White Bluff BART 

analysis are considerably higher than 

the cost estimates for similar controls at 

the other coal fired EGUs. The EPA 

notes that the Entergy White Bluff Units 

1 and 2 have a slightly greater 

generating capacity (850 MW each), but 

because of the lack of detail in Entergy 

White Bluff’s cost calculations, it is not 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14645 

173Appendix Y to Part 51, section IV.4. 

174See ‘‘BART Analysis for Lake Catherine PlantUnit 4,’’ prepared by Robert Paine, dated December 

2006 (Appendix 9.3A of the Arkansas RH SIP). 

175EPRI document entitled ‘‘Retrofit NOX Control 

Guidelines for Gas and Fired Boilers,’’ Version 2, 

June 1997. 

176See Appendix 9.3B of the RH SIP. 

177Appendix Y to Part 51, section IV.4. 

clear what issues are attributing to the 

wide difference in the annualized cost 

estimates. As explained in our proposed 

rulemaking, the State must provide 

proper documentation of all cost 

calculations, and a reasonably detailed 

breakdown in costs. In cases where the 

State finds that cost of controls are 

unusually high, especially in 

comparison to the cost of the same 

controls at other similar sources, the 

State must provide a more detailed 

breakdown of costs, as provided in the 

BART Guidelines.173

Comment: The EPA was incorrect in 

its assessment of Entergy’s Lake 

Catherine Unit 4 BART determination 

that Entergy provided no documentation 

or detailed breakdown of cost. Entergy 

only included the expected capital cost 

and any impacts the control technology 

will have on the unit heat rate in the 

cost estimate, which is a conservative 

cost estimate of the cost of each control 

technology. Entergy’s methods of 

calculations are described in the 

Appendix of the Determination Report. 

This approach is supported by EPA’s 

BART Guidelines. In addition, by 

incorporating the costs provided by 

Entergy in the RH SIP Arkansas 

supports Entergy’s cost analysis. 

Response: The comment appears to be 

in contradiction with what was 

documented in Arkansas’s RH SIP. In 

Appendix 9.3B of the Arkansas RH SIP, 

Entergy states that a computerized 

model was used to evaluate electrical 

generating unit performance and the 

capital and operation and maintenance 

cost associated with each identified 

control technology. As such, the State 

should provide proper documentation 

of the equipment costs with data 

supplied by an equipment vendor or by 

a referenced source, and include a 

reasonably detailed breakdown of all 

cost estimates. The Appendix to the 

Determination Report referenced in the 

comment appears to be ‘‘Appendix A: 

Cost and Emissions Estimates for NOX

and SO2 Control Options.’’ 174 This 

document contains the total annual cost 

(with no breakdown), the costeffectiveness and the incremental costeffectiveness calculated by Entergy of 

the controls considered in the BART 

analysis, along with formulas that were 

used by the source in calculating costs 

(i.e. total capital requirement, levelized 

control cost, etc.). But the actual 

calculations or numbers that went into 

these formulas are not included. As 

explained in our response to other 

comments, this approach is not 

supported by the BART Guidelines. We 

also note that the State’s support for a 

particular cost analysis alone is not 

grounds for EPA approval. The EPA 

must evaluate the details of a cost 

analysis and determine whether it meets 

the RH requirements and BART 

Guidelines before we can consider it in 

approving or disapproving a BART 

determination. 

Comment: Entergy demonstrated that 

post-combustion NOX controls for Lake 

Catherine Unit 4 are not economically 

viable. Thus, EPA should not have 

disapproved Lake Catherine Unit 4’s 

BART determination on the grounds 

that post-combustion controls were not 

evaluated. ADEQ noted that in the 

BART analysis for Lake Catherine 

facility Entergy used a computerized 

model that evaluated EGU performance 

and the cost associated with each 

identified technology. Entergy’s analysis 

started with the most economical 

control technology and then conducted 

a stepped approach where the next 

economical control was analyzed. The 

analysis continued with a combination 

of all identified control technologies. 

Entergy reported the combination of 

control technologies until that 

combination was no longer cost 

effective. This is consistent with the 

BART Guidelines which provide that in 

the BART review, one or more of the 

available control options may be 

eliminated from consideration if it is 

demonstrated to be technically 

infeasible or to have unacceptable 

energy, cost, or non-air quality 

environmental impacts on a case by case 

basis. The incremental NOX control cost 

of $41,739/ton (option 5) and $10,101/ 

ton (option 4) shown in the Lake 

Catherine BART analysis do not pass 

the cost test as described in the BART 

Guidelines. This is consistent with the 

BART Guidelines, which provide that 

installation of current combustion 

control technology is cost-effective and 

should be considered in determining 

BART for oil- and gas-fired sources. 

Response: As noted in our proposed 

rulemaking, we agree that the RH SIP 

includes the results of a computerized 

model the source used to calculate the 

costs associated with each technology. 

However, the SIP includes no detailed 

breakdown of the costs. The only 

explanation of the model is a paragraph 

in Appendix 9.3B, which points out that 

inputs that went into the model were 

based on inputs derived from the EPRI 

document entitled ‘‘Retrofit NOX

Control Guidelines for Gas and Oil Fired 

Boilers,’’ 175 which were further 

analyzed to reflect performance 

expected for Lake Catherine Unit 4, as 

‘‘each specific boiler will perform 

differently due to the unique 

characteristics of that boiler.’’ 176 The 

BART Guidelines provide that States 

should include documentation for any 

additional information used for the cost 

calculations, including any information 

supplied by vendors that affects the 

assumptions regarding purchased 

equipment costs, equipment life, and 

other elements of the calculation.177 We 

find that this documentation was not 

provided by Arkansas. 

The comment states that postcombustion controls were eliminated 

from consideration because they were 

found to be not cost-effective. Based on 

the information provided from the 

Entergy’s computer model, the costeffectiveness of a combination of 

combustion controls and SNCR is 

$3,378/NOX ton removed. Again, the 

issue of documentation aside, we find 

that Arkansas should have evaluated the 

visibility impact of this and each of the 

other control options considered at each 

potentially affected Class I area before 

eliminating any given control option. 

The comment also notes that some 

control options, including options 4 and 

5 that are each a combination of 

combustion controls, were eliminated 

from consideration based on their 

incremental cost-effectiveness. 

However, the BART Guidelines provide 

that the average cost-effectiveness 

(which was reported by the source to be 

$1,701/ton for option 4 and $3,757/ton 

for option 5), in addition to the visibility 

impacts from the installation of controls 

at each potentially affected Class I area, 

should also be taken into consideration 

before a BART determination is made. 

Based on average cost effectiveness, 

these options should not be eliminated 

from consideration. As the BART 

Guidelines explain, cost effectiveness 

cannot be assessed without an analysis 

of the projected visibility benefit. This 

holds true even for control options 

evaluated on the basis of their 

incremental cost effectiveness. In the 

preamble to the BART Rule, in response 

to comments that modeling should not 

be included as part of a BART review, 

EPA supported its decision to include 

modeling by stating that CAA section 

169(g)(2) clearly requires an evaluation 

of the expected degree of improvement 


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14646 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

178 70 FR 39129. 

179 70 FR 39129. 

180 70 FR 39130. 

181Appendix Y to Part 51, section IV.E.5. 

in visibility from BART Controls.178 The 

BART Rule also states the following: 

‘‘We believe that modeling, which provides 

model concentration estimates that are 

readily converted to deciviews, is the most 

efficient way to determine expected visibility 

improvement.’’ 179

Furthermore, in the preamble to the 

BART Rule, in response to comments 

received, we stated the following: 

‘‘We agree with commenters who asserted 

that the method for assessing BART controls 

for existing sources should consider all of the 

statutory factors.’’ 180

Therefore, Arkansas must evaluate all 

five statutory factors before eliminating 

a given control option, especially if 

there are no unusual circumstances that 

would make it clear that a particular 

control option should be eliminated 

before all five statutory factors are 

considered. With regard to the comment 

that the BART Guidelines provide that 

installation of current combustion 

control technology is cost-effective and 

should be considered in determining 

BART for oil- and gas-fired sources, we 

note the context of that statement is 

with regard to whether we believed a 

presumptive emission limit was 

appropriate for oil and gas fired 

EGUs.181 It was not intended to limit the 

consideration for BART of possible postcombustion control options. 

Comment: Arkansas’s failure to 

consider the actual costs of compliance 

for its BART determination is reflected 

by the APCEC rulemaking record for the 

Arkansas RH SIP. No actual costs of 

compliance with presumptive limits for 

the White Bluff and Flint Creek facilities 

are provided. The petition to initiate 

rulemaking before the APCEC contains 

no information about the costs to install 

the required control technology at these 

two plants nor does it identify or 

contain any explanation of the five 

BART factors that the APCEC is 

supposed to consider under the CAA. 

The financial documentation filed in 

support of the petition contains no 

indication of the actual costs of 

compliance. The documentation 

suggests that the financial impact of the 

rule to the citizens and ratepayers of 

Arkansas would be zero. Thus, Arkansas 

should not have adopted EPA’s 

presumptive limits for the Entergy 

White Bluff Units 1 and 2 and AEP Flint 

Creek Boiler 1 without first determining 

whether the assumptions underlying 

those presumptive emission limits, 

including the costs of compliance, were 

still valid and reasonable. 

Response: EPA notes that the APCEC 

is the State’s rulemaking body for 

environmental regulations. EPA agrees 

that the rulemaking record for the 

Arkansas RH SIP lacks sufficient 

information to support the State’s BART 

determinations for the two facilities. As 

reflected in our proposed rulemaking 

and in our previous response to 

comments, the State should have 

conducted a proper evaluation of the 

five statutory factors before adopting the 

NOX and SO2 presumptive limits for 

BART for Entergy White Bluff Units 1 

and 2 and Flint Creek Boiler 1. 

6. Comments on the August 2008 

Revised BART Analysis for White Bluff 

Comment: The EPA’s evaluation of 

the BART submittal for Entergy White 

Bluff Units 1 and 2 is based on a 

December 2006 BART analysis 

submitted by Entergy Arkansas Inc., and 

included in the Arkansas RH SIP in 

Appendix 9.3A. Entergy subsequently 

submitted a revised BART analysis to 

ADEQ for White Bluff on August 8, 2008 

(see Exhibit 11), stating that this revised 

document should supersede the 

Entergy’s original December 2006 BART 

determination for White Bluff. It does 

not appear that ADEQ ever adopted the 

revised BART analysis as part of the 

Arkansas RH SIP, but in 2009 ADEQ did 

propose to issue a Title V permit for 

White Bluff that proposed to incorporate 

the control equipment proposed by 

Entergy in its revised 2008 BART 

analysis to meet BART. These controls 

differed from the controls assumed to 

meet BART in Entergy’s 2006 BART 

analysis. Specifically, the 2006 BART 

analysis proposed to install wet 

scrubbers to achieve the SO2

presumptive limit of 0.15 lb/MMBtu 

and no additional controls for PM, 

while the revised 2008 BART analysis 

proposed to install dry scrubbers and 

baghouses to meet the SO2 presumptive 

limit of 0.15 lb/MMBtu and no 

additional controls for PM. Although 

ADEQ never issued the permit it 

proposed in 2009, it appears that 

Entergy may intend to change its 

planned controls to meet BART. The 

EPA’s proposal does not mention 

Entergy’s revised 2008 BART analysis 

because it has not yet been adopted by 

Arkansas as a SIP revision, and it is 

therefore not before EPA to approve or 

disapprove. However, as EPA acts on 

the Arkansas RH SIP, it must consider 

that Entergy may be installing a 

baghouse as part of its SO2 controls. 

Since a baghouse is more effective at 

controlling PM emissions than an ESP, 

EPA should not act on the state’s 

proposed PM BART limit until it has a 

complete and approvable suite of BART 

controls that it is acting on or otherwise 

promulgating as a FIP. 

Response: The EPA agrees that the 

December 2006 White Bluff BART 

analysis is what was included in 

Appendix 9.3A of the Arkansas RH SIP 

received by EPA on September 23, 2008. 

As such, that is the BART analysis that 

is before EPA to take action on. EPA 

does not have the authority to take 

action on a SIP revision that has never 

been officially submitted by the State. 

As the comment notes, the controls 

assumed to meet BART in Entergy’s 

2008 revised BART analysis differ from 

those in the 2006 BART analysis that 

was submitted to EPA as part of the 

Arkansas RH SIP. However, since to the 

best of EPA’s knowledge, the State has 

never officially adopted the 2008 

revised BART analysis as a revision to 

the Arkansas RH SIP and since the State 

never issued the permit that proposed to 

install the controls in the 2008 revised 

BART analysis, it is not clear if the State 

is even considering submitting such a 

revised SIP to EPA. As such, EPA can 

only review what has been submitted to 

it by Arkansas. Therefore, we are basing 

our decision upon Arkansas’s submitted 

RH SIP and our review of comments. As 

articulated in our proposed rulemaking 

and elsewhere in our response to 

comments, we find that the current 

permit limit (i.e. no additional controls) 

is PM BART for Entergy White Bluff 

Units 1 and 2 for both bituminous and 

sub-bituminous coal firing scenarios. 

Comment: The EPA cannot propose to 

disapprove the BART determination for 

SO2 for the Entergy White Bluff Units 1 

and 2 because the EPA did not evaluate 

the most recent and more detailed 

BART analysis conducted for Entergy’s 

White Bluff facility when making its 

decision. The EPA’s proposal references 

the 2006 BART analysis as the basis for 

EPA’s decision on Arkansas’s White 

Bluff BART determinations and not the 

2008 revised BART analysis. The 2008 

revised BART analysis considered 

additional non-air quality 

environmental impacts and provided a 

detailed BART five factor analysis. The 

2008 revised BART report was 

evaluated by ADEQ and provided to 

EPA. Even though EPA did not consider 

the 2008 revised BART analysis in its 

proposed rulemaking, it agreed with its 

findings in a 2009 letter to ADEQ staff 

that installation of dry scrubber 

technology is BART for the White Bluff 

facility. The EPA’s lack of consideration 

of the most current and accurate BART 

analysis and determination for the 

White Bluff facility makes EPA’s 


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Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14647 

182Letter from Mark C. Bowles, Arkansas 

Environmental Support Manager, to Mike Bates, Air 

Division Chief, ADEQ, dated August 8, 2008. Please 

see the docket for this rulemaking for a copy of this 

letter. 

183Letter from Jeff Robinson, Air Permits Chief, 

EPA Region 6, to Tom Rheaume, Permits Branch 

Manager, ADEQ, dated November 25, 2009. 

184Appendix Y to Part 51, section II.A. 

185Appendix Y to Part 51, section II.A. 

186Appendix Y to Part 51, section IV.D. 

187 64 FR 35740. 

proposed rule regarding the White Bluff 

facility inaccurate and arbitrary. 

Response: The EPA notes that the 

December 2006 White Bluff BART 

analysis is the BART analysis that was 

included in Appendix 9.3A of the 

Arkansas RH SIP received by EPA on 

September 23, 2008. As such, the 

December 2006 White Bluff BART 

analysis is what is before EPA to take 

action on. The EPA does not have the 

authority to take action on a SIP 

revision that has never been officially 

submitted by the State. The EPA is 

aware that in a letter dated August 8, 

2008, sent by Entergy to ADEQ, the 

source requests that the 2008 revised 

BART analysis supersede the 2006 

BART analysis.182 The EPA notes that 

the CAA places the authority and duty 

to submit SIPs on the states. Under the 

RH regulations, it is the State who is 

authorized to make BART 

determinations for inclusion in the RH 

SIP submitted to EPA. As such, even if 

a source submits a revised BART 

analysis to the State and requests that 

the revised version supersede the one 

currently in the RH SIP, EPA is not 

authorized to take action on the revision 

if the State does not adopt the revised 

version as a revision to the RH SIP, 

allow the FLM to review the proposed 

RH SIP revision at least 60 days prior to 

holding any public hearing, undergo 

reasonable notice and public hearing, 

and submit the revision to EPA in the 

context of an official SIP submission. 

This did not happen. 

While EPA did provide comments in 

a letter dated November 25, 2009, to the 

State on the 2008 revised BART analysis 

for White Bluff, this was done in the 

context of EPA’s review of a draft Title 

V/Prevention of Significant 

Deterioration (PSD) permit for White 

Bluff.183 Since the draft Title V permit 

proposed by the State proposed to 

incorporate the control equipment 

proposed by Entergy in the 2008 revised 

BART analysis for White Bluff, the 2008 

BART analysis was provided as an 

attachment to the proposed permit. Our 

review of the draft Title V permit did 

not involve a full review of the 2008 

BART analysis, as we were only 

reviewing that BART analysis in the 

context of providing comments to the 

State on the draft Title V permit. In the 

comment letter EPA sent to the State, 

we did note that we agreed that dry 

scrubber technology is generally 

considered BART, but we also noted 

that we did not agree that the SO2

emission limit proposed by the source is 

reflective of the control efficiency this 

control technology is capable of 

achieving, and that we did not agree 

that this SO2 emission limit of 0.15 lb/ 

MMBtu is BART. Our superficial review 

of the 2008 revised BART analysis also 

revealed that many of the same flaws we 

identified in our proposed rulemaking 

for the 2006 White Bluff BART analysis 

are also found in the 2008 White Bluff 

analysis. Furthermore, the draft Title V 

permit that proposed to incorporate the 

control equipment proposed by Entergy 

in the 2008 revised White Bluff BART 

analysis was never issued by the State. 

We disagree that our rulemaking 

regarding White Bluff Units 1 and 2 is 

inaccurate and arbitrary because the 

EPA did not rely on the 2008 revised 

White Bluff BART analysis, as the 2008 

revised White Bluff BART analysis is 

not before EPA to take action on. 

7. Other Comments Related to BART 

Comment: The EPA’s proposed 

disapproval of BART for the Entergy 

White Bluff auxiliary boiler is legally 

incorrect because the unit is not BART 

eligible. The EPA disapproved ADEQ’s 

BART determination that BART for the 

White Bluff auxiliary boiler is a 

restriction to operate no more than 4360 

hours annually. However, the White 

Bluff auxiliary boiler has only a heat 

input capacity of 183 MMBtu/hr, which 

is less than the BART-eligible threshold 

of 250 MMBtu/hr. The BART Guidelines 

supports this finding that units which 

are located at a steam electric plant, but 

which themselves are not in any of the 

26 BART source categories, such as the 

White Bluff auxiliary boiler, should not 

be considered BART-eligible. Further, 

the Guidelines state that for fossil-fuel 

boilers more than 250 MMBtu/hour heat 

input, this category includes only those 

boilers that are individually greater than 

250 MMBtu/hour heat input. 

Response: The EPA agrees that the 

Auxiliary Boiler (SN–05) at the Entergy 

White Bluff Plant does not fall into 

‘‘Category 2’’ (i.e. fossil-fuel boilers of 

more than 250 million BTU/hr heat 

input) under the BART Guidelines. 

However, as noted in our proposed 

rulemaking, it does fall into ‘‘Category 

1’’ (i.e. steam electric plants of more 

than 250 million BTU/hr heat input) 

under the BART Guidelines. The BART 

Guidelines state the following regarding 

the BART eligibility of steam electric 

plants of more than 250 MMBTU/hr 

heat input: 

‘‘Because the category refers to ‘plants,’ we 

interpret this category title to mean that 

boiler capacities should be aggregated to 

determine whether the 250 million BTU/hr 

threshold is reached. This definition includes 

only those plants that generate electricity for 

sale.’’ 184

The BART Guidelines also provide 

the following example to help states 

determine whether a boiler at a steam 

electric plant of more than 250 MMBtu/ 

hr heat input falls into ‘‘Category 1’’ (i.e. 

steam electric plants of more than 250 

million BTU/hr heat input) under the 

BART Guidelines: 

‘‘Example: A stationary source includes a 

steam electric plant with three 100 million 

BTU/hr boilers. Because the aggregate 

capacity exceeds 250 million BTU/hr for the 

‘plant,’ these boilers would be identified in 

Step 2.’’ 185

Therefore, even though the Auxiliary 

Boiler (SN–05) at the Entergy White 

Bluff Plant is individually only 183 

MMBtu/hr, since it is located at a plant 

where the aggregate capacity exceeds 

250 MMBtu/hr, the Auxiliary Boiler is 

BART eligible and, as explained in our 

proposed rulemaking, subject to BART. 

As such, our proposed disapproval of 

BART for the auxiliary boiler is 

consistent with the BART Guidelines 

and is legally correct. For the reasons 

articulated in our proposed rulemaking, 

we are finalizing our proposed 

disapproval of BART for the Auxiliary 

Boiler (SN–05) at the Entergy White 

Bluff plant. 

Comment: The EPA has not 

demonstrated in its proposed partial 

disapproval of Arkansas RH SIP that 

post-combustion controls are costeffective. The EPA has also not 

demonstrated that Arkansas’s reliance 

on presumptive limits without 

analyzing post-combustion controls 

abused its authority to determine the 

appropriateness of the selected BART 

technologies. 

Response: The BART Guidelines 

provide that in identifying all options, 

you must identify the most stringent 

option as well as a reasonable set of 

options for analysis.186 The RHR also 

provides that in establishing source 

specific BART emission limits, the State 

should identify and consider in the 

BART analysis the maximum level of 

emission reduction that has been 

achieved in other recent retrofits at 

existing sources in the source 

category.187 The visibility regulations 

define BART as ‘‘an emission limitation 

based on the degree of reduction 

achievable through the application of 

the best system of continuous emission 


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188 76 FR at 64186, at 64187. 

reduction.’’ Since recent retrofits at 

existing sources provide a good 

indication of the current ‘‘best system’’ 

for controlling emissions, these controls 

must be considered in the BART 

analysis. As explained in our proposed 

rulemaking, post-combustion controls 

for NOX, SO2, and PM have been 

demonstrated to be technically feasible 

and cost-effective controls at fossil fuel 

fired EGUs that are similar to those that 

are subject to BART in Arkansas. As 

articulated in our proposed rulemaking 

(and also discussed elsewhere in our 

response to comments), EPA is also 

aware of at least one type of NOX postcombustion control (SNCR) that has 

been demonstrated to be technically 

feasible for a power boiler at a kraft pulp 

mill with similar design specifications 

as Domtar Ashdown Mill Power Boilers 

No. 1 and 2. Therefore, states must 

consider post-combustion controls in 

their BART analyses for NOX, SO2, and 

PM if such controls have been recently 

installed as retrofits at existing sources 

in the source category. 

Furthermore, our disapproval of some 

of Arkansas’s BART determinations 

where the State did not consider postcombustion controls, is not based on a 

demonstration by EPA that postcombustion controls are cost-effective at 

any of Arkansas’s subject to BART 

sources. Instead, it is based on our 

finding that some of the State’s BART 

analyses did not satisfy the RHR and 

applicable EPA guidance. We did not 

perform a source specific BART analysis 

to determine if post-combustion 

controls are cost-effective at Arkansas’s 

subject to BART sources nor are we 

required to perform such an analysis in 

reviewing a SIP revision. As explained 

in our response to other comments and 

as required by CAA section 169A(g)(2) 

and 40 CFR 51.308(e)(1)(ii)(A), it is the 

State’s responsibility to conduct a five 

factor BART analysis that satisfies the 

RHR and BART Rule using the NOX and 

SO2 presumptive emission limits as a 

starting point in the BART analysis. In 

addition, as explained above, states 

must consider post-combustion controls 

in their BART analyses for NOX, SO2, 

and PM if such controls are technically 

feasible. It is EPA’s responsibility to 

review the adequacy of this analysis. 

Comment: The EPA’s proposed 

disapproval is inconsistent with EPA’s 

guidance and regulations concerning 

visibility protection causing regulatory 

uncertainty among the EGU industry. 

The EPA’s proposed disapproval action 

should be withdrawn in favor of 

approval of the Arkansas RH SIP. 

Response: Because the comment is 

not specific about what aspect of our 

proposed disapproval is believed to be 

inconsistent with EPA guidance and RH 

regulations, it is not possible for EPA to 

address in this response any specific 

concerns. Several similar comments 

raised very specific concerns. Our 

responses to these can be found 

elsewhere in our responses to 

comments. As articulated in our 

proposed rulemaking and further 

explained in our responses to other 

comments, EPA’s partial approval and 

partial disapproval of the Arkansas RH 

SIP is consistent with the CAA, the 

RHR, BART Rule, and EPA guidance. 

Since our rulemaking is consistent with 

the above, we disagree that it causes 

regulatory uncertainty among the EGU 

industry. 

Comment: Arkansas’s BART 

determinations are consistent with the 

BART Guidelines and EPA should defer 

to the state’s decision. Instead of 

deferring to the state’s judgment about 

the necessary measures to implement 

BART within its borders, EPA proposed 

to substitute its judgment concerning 

what constitutes BART and what 

constitutes an acceptable LTS for 

making reasonable progress toward the 

national goal. 

Response: The EPA disagrees that all 

of Arkansas’s BART determinations 

satisfy the CAA, the RHR, BART Rule, 

and EPA guidance. For some BART 

determinations, Arkansas adopted NOX

and SO2 presumptive limits without 

conducting a source-specific analysis of 

appropriate levels of control when those 

sources have the capability of more 

stringent controls. This is in 

contradiction with the RHR and the 

BART Guidelines. We have determined 

that Arkansas’s failure to conduct the 

BART analysis despite the evidence that 

the BART analysis might result in 

adoption of a different emissions limit 

was significant enough to result in 

BART determinations that were 

unreasoned and unjustified. 

Accordingly, those BART 

determinations, that adopted 

presumptive limits without conducting 

any additional BART analysis when 

information exists that may affect the 

BART determination, are not 

approvable. For some BART 

determinations, Arkansas did not 

perform a full BART analysis by not 

considering one or more factors it is 

required to consider in determining 

whether retrofit control should be 

required. We have determined that not 

considering one or more BART factors 

by Arkansas in its BART 

determinations, when it is demonstrable 

that this lack of analysis could alter the 

BART determination, is unreasoned and 

unsupportable. Thus, those BART 

determinations, which lack the 

consideration of one or more BART 

factors when it can be demonstrated that 

lack of consideration of the BART factor 

has the potential to alter the BART 

determination, are not approvable. We 

are also disapproving Arkansas’s LTS 

because it does not satisfy the 

requirements under 40 CFR 51.308(d)(3) 

by relying on BART determinations that 

are inconsistent with the CAA and the 

RHR as detailed in our BART 

disapproval actions.188 As explained in 

our response to other comments, EPA 

agrees that States have broad authority 

and flexibility under the RHR. 

Furthermore, we are not substituting our 

judgment and forcing Arkansas to adopt 

any specific BART determination. 

Rather, we are disapproving portions of 

Arkansas’s RH SIP that address BART, 

the LTS, and the RPGs because the State 

omitted critical analyses and made 

flawed assumptions that may 

compromise any decisions that arise 

from it. In doing so, the State did not 

satisfy the requirements of the CAA, 

RHR, and the BART Rule. The state 

could submit and EPA would approve 

RH SIP revisions that reached identical 

determinations as the current SIP 

submittal if Arkansas’s analyses in 

reaching those determinations are 

consistent with the CAA, RHR, and 

BART Rule. 

Comment: Because of the limited 

ability to combust fuel oil on a shortterm basis for the Domtar Ashdown Mill 

Power Boiler No.1, a higher SO2

emission rate was proposed of 1.12 lb/ 

MMBtu even though the average longterm emissions are low. The EPA is 

incorrect in stating that there is a 

mismatch between ADEQ’s high BART 

SO2 emission limit and the emission 

needs of the Domtar Power Boiler No.1 

when you take into account the actual 

operation of and the fuels used by the 

boiler. 

Response: As articulated in our 

proposed rulemaking, as part of its 

BART analysis, the State should have 

conducted a fuel inventory for Domtar 

Power Boiler No. 1 and investigated 

sources of potential sulfur emissions. If 

the source believes that burning fuel oil 

on a relatively long-term basis is the 

primary source of high SO2 emissions 

from Domtar Power Boiler No. 1, the 

State should consider in its BART 

analysis establishing a limit on the 

sulfur content of the fuel oil burned at 

the boiler and/or lowering the limit of 

fuel oil usage. In addition, if the boiler 

operator wishes to burn fuel oil on a 

long-term basis and this is the primary 

source of SO2 emissions from the boiler, 

the State should evaluate SO2 postVerDate Mar<15>2010 14:56 Mar 09, 2012 Jkt 226001 PO 00000 Frm 00046 Fmt 4701 Sfmt 4700 E:\FR\FM\12MRR2.SGM 12MRR2

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189Appendix Y to Part 51, section IV.E.4. 

combustion controls in its BART 

analysis. A proper BART evaluation of 

SO2 controls may demonstrate that the 

installation and operation of an SO2

scrubber is cost-effective and would 

result in significant visibility 

improvement. 

Comment: With regard to the 

evaluation of upgrades to the existing 

scrubber at Domtar’s Power Boiler No. 2, 

multiple scrubber upgrades were 

considered including the addition of a 

spray tower and/or a third scrubber. 

Preliminary estimates of capital costs for 

the third scrubber exceed $10 million 

not taking into account the expenses of 

installing the technology in a limited 

space. Considering Arkansas’s progress 

towards the overall goal of the RH 

program, such costs are clearly not 

justified. 

Response: As articulated in our 

proposed rulemaking, the BART 

Guidelines provide that if a state 

determines that a source has controls 

already in place that are the most 

stringent controls available and that all 

possible improvements to any control 

devices have been made, it may take a 

streamlined approach for the BART 

analysis for this source. Since the source 

has an existing wet scrubber for control 

of SO2 emissions, Arkansas has elected 

to take this streamlined approach for 

Power Boiler No.2. As explained in our 

proposed rulemaking, we agree that SO2

post-combustion controls are typically 

the most stringent technology available 

for control of SO2. However, we disagree 

that a BART emission limit of 1.2 lb/ 

MMBtu for SO2 is reflective of the most 

stringent controls available. Further, the 

State has not provided sufficient 

documentation of the upgrades 

considered for the existing wet scrubber. 

In addition, based on the information 

available, it also appears that the State 

has not considered all possible 

improvements to the scrubber. As 

articulated in our proposed rulemaking, 

the BART Guidelines state that there are 

numerous scrubber enhancements 

available to upgrade the average 

removal efficiencies of all types of 

existing scrubber systems, including 

increasing a scrubber system’s reliability 

(and conversely decreasing its 

downtime) by way of optimizing 

operational procedures, improving 

maintenance practices, adjusting 

scrubber chemistry, and increasing 

auxiliary equipment redundancy.189

The BART Guidelines also provide the 

following detailed list of potential 

scrubber upgrades that have been 

proven in the industry as cost-effective 

means to increase overall SO2 removal 

of wet systems: 

• Elimination of Bypass Reheat 

• Installation of Liquid Distribution 

Rings 

• Installation of Perforated Trays 

• Use of Organic Acid Additives 

• Improve or Upgrade Scrubber 

Auxiliary System Equipment 

• Redesign Spray Header or Nozzle 

Configuration 

Based on the limited information that 

has been provided to EPA, it does not 

appear that the State has evaluated all 

possible improvements to the existing 

wet scrubber at Domtar Ashdown Mill 

Power Boiler No. 2. Therefore, the State 

must either consider all possible 

improvements to the existing wet 

scrubber (including proper 

documentation of these) or conduct a 

full five factor BART analysis that 

satisfies the requirements of the RHR 

and the BART Rule for Power Boiler No. 

2. EPA is finalizing our proposed 

disapproval of the State’s SO2 BART 

determination for the Domtar Power 

Boiler No. 2. 

Comment: The EPA should not 

question if the proposed SO2 BART 

limit of 1.2 lb/MMBtu represents 90% 

control for Domtar’s Power Boiler No. 2. 

The 90% control value has never been 

confirmed via testing. Rather this 

control efficiency was estimated based 

on a comparison of the actual maximum 

daily emissions measured via CEMS and 

the uncontrolled emission rate 

predicted by EPA’s AP–42 data. It may 

be overestimated, but the percent 

control value is somewhat irrelevant 

due to the BART limit on a lb/MMBtu 

basis. 

Response: As articulated in our 

proposed rulemaking, we agree that SO2

post-combustion controls are typically 

the most stringent technology available 

for control of SO2. However, we disagree 

that a BART emission limit of 1.2 lb/ 

MMBtu for SO2 is necessarily reflective 

of the most stringent controls available. 

Since Arkansas has elected to take the 

streamlined approach for the SO2 BART 

analysis for this source, it must ensure 

that the source has controls already in 

place that are the most stringent 

controls available and that all possible 

improvements to any control devices 

have been made. This has not been 

done. Since the State is relying on the 

fact that the source has the most 

stringent controls in place to take a 

streamlined approach to the BART 

analysis, we disagree that the control 

efficiency of the existing wet scrubber is 

irrelevant. As explained elsewhere in 

our response to comments, the State 

must either ensure it has the most 

stringent controls in place and consider 

all possible improvements to the 

existing wet scrubber (including proper 

documentation of these) or conduct a 

five factor BART analysis that satisfies 

the requirements of the RHR and the 

BART Rule for Domtar Power Boiler No. 

2. EPA is finalizing our proposed 

disapproval of the State’s SO2 BART 

determination for Domtar’s Power Boiler 

No. 2. 

Comment: Since EPA is proposing to 

partially approve and partially 

disapprove portions of the Arkansas 

SIP, EPA should clarify that the 

compliance dates are all based on the 

same final approval date of the entire 

SIP. Compliance should be five years 

after final approval by EPA. 

Response: The EPA disagrees that 

compliance with the BART 

requirements is contingent upon full 

approval of the entire Arkansas RH SIP. 

40 CFR 51.308(e)(iv) requires subject to 

BART sources to install and operate 

BART as expeditiously as practicable, 

but in no event later than 5 years after 

the approval of the implementation plan 

revision. Therefore, in the event of a 

partial approval of the RH SIP, those 

sources whose BART determinations for 

a particular pollutant have been 

approved by EPA are required to install 

BART as expeditiously as practicable, 

but in no event later than 5 years after 

the partial approval of the BART 

determination. The RH regulatory 

language in no way conditions the 

BART compliance dates on EPA’s full 

approval of the entire RH SIP. 

Comment: Arkansas did a proper 

BART evaluation for Entergy Lake 

Catherine Unit 4 and White Bluff Units 

1 and 2 when it adopted the 

presumptive limits. Arkansas did the 

BART five factor analyses, which is 

consistent with the BART Guidelines. 

EPA’s proposed disapproval of 

Arkansas’s NOX and SO2 BART 

determinations for Entergy’s White Bluff 

and Lake Catherine facilities is based on 

EPA’s incorrect evaluation of Arkansas’s 

BART analyses and prioritizes EPA’s 

disagreements with Arkansas 

concerning available technologies and 

the associated costs of compliance over 

the visibility protection program’s 

fundamental purpose of remedying 

visibility impairment by 2064, which 

the Arkansas’s RH SIP achieves. The 

EPA’s disapproval for Arkansas’s BART 

determinations for Entergy Lake 

Catherine and White Bluff facilities is a 

disagreement with the results of the 

BART determination as to the 

appropriate level of control for the Lake 

Catherine and White Bluff facilities. 

Accordingly, EPA should withdraw its 

proposed partial disapproval and 

approve the existing Arkansas RH SIP. 


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14650 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

190EPA notes that in our proposed rulemaking on 

the Arkansas RH SIP, we proposed to find that 

Arkansas did not appropriately consider the costs 

of controls when they assumed a 10% capacity 

factor for Lake Catherine Unit 4 and an 85% 

capacity factor for White Bluff Units 1 and 2. Based 

on comments received during the public comment 

period, we have found that we made an error in 

proposed rulemaking in our calculation of the 

historical capacity factors for these units. We agree 

that assuming a 10% capacity factor for Lake 

Catherine and an 85% capacity factor for White 

Bluff Units 1 and 2 in the calculation of emissions 

reductions achieved and cost of controls is 

appropriate and in accordance with the BART 

Guidelines (see our response to other comments in 

our response to comments for a more detailed 

explanation). However, we still find that Arkansas 

did not appropriately consider a number of factors 

(as articulated in our proposed rulemaking and 

explained elsewhere in our response to comments) 

in its five factor BART analysis for NOX BART 

(natural gas and fuel oil firing), and SO2 and PM 

(fuel oil firing) BART for Lake Catherine Unit 4, and 

for NOX and SO2 BART (bituminous and subbituminous coal firing) for White Bluff Units 1 and 

2. Therefore, we are finalizing our disapproval of 

BART for the aforementioned pollutants and units. 

191Appendix Y to Part 51, section IV.D.1. 

192 76 FR 52604 and 76 FR 80754. 

Response: As explained in our 

proposed rulemaking,190 we disagree 

that Arkansas did a proper five factor 

BART evaluation for NOX and SO2

BART when it adopted the presumptive 

limits for White Bluff Units 1 and 2, and 

we also disagree that Arkansas did a 

proper five factor BART evaluation for 

NOX BART (natural gas and fuel oil 

firing) and SO2 and PM BART (fuel oil 

firing) for Lake Catherine Unit 4. We do 

note that in our proposed rulemaking on 

the Arkansas RH SIP, we proposed to 

find that Arkansas did not appropriately 

consider the costs of controls when they 

assumed a 10% capacity factor for Lake 

Catherine Unit 4 and an 85% capacity 

factor for White Bluff Units 1 and 2. 

Based on comments received during the 

public comment period, we have found 

that we made an error in proposed 

rulemaking in our calculation of the 

historical capacity factors for these 

units. We agree that assuming a 10% 

capacity factor for Lake Catherine and 

an 85% capacity factor for White Bluff 

Units 1 and 2 in the calculation of 

emissions reductions achieved and cost 

of controls is appropriate and in 

accordance with the BART Guidelines 

(see our response to similar comments 

for a more detailed explanation). 

However, we still find that Arkansas 

did not appropriately consider a number 

of factors (as articulated in our proposed 

rulemaking and explained elsewhere in 

our response to comments) in its fivefactor BART analysis for NOX BART 

(natural gas and fuel oil firing), and SO2

and PM (fuel oil firing) BART for Lake 

Catherine Unit 4, and for NOX and SO2

BART (bituminous and sub-bituminous 

coal firing) for White Bluff Units 1 and 

2. The State’s BART analyses for Lake 

Catherine Unit 4 and White Bluff Units 

1 and 2 for the aforementioned 

pollutants do not satisfy all the 

requirements of the RHR and BART 

Guidelines. As such, our disapproval of 

the BART determinations for Lake 

Catherine Unit 4 and White Bluff Units 

1 and 2 is not based on our 

disagreement with the results of the 

BART determination as to the 

appropriate level of control for the Lake 

Catherine and White Bluff facilities. 

Instead, our disapproval is based on our 

finding that Arkansas’s BART analyses 

for these units and pollutants do not 

satisfy all the requirements of the RHR 

and BART Guidelines. The State 

omitted critical analyses and made 

flawed assumptions that compromise 

the resulting BART determinations. As 

such, until a proper five-factor BART 

analysis is conducted for these 

pollutants that satisfies all the statutory 

and regulatory RH requirements and 

adheres to the applicable guidelines, it 

will not be possible to know whether 

the level of control adopted by the State 

or a different level of control is BART 

for these units and pollutants. The state 

could submit and EPA would approve 

RH SIP revisions that reached identical 

determinations as the current SIP 

submittal if Arkansas’s analysis in 

reaching those determinations is 

consistent with the RHR and applicable 

EPA Guidance. As explained elsewhere 

in our response to comments, even if the 

CENRAP’s modeling shows that the 

State is expected to meet the URP for 

the first implementation period ending 

in 2018 and is projected to meet the 

natural visibility goal by 2064 if the 

same level of visibility improvement 

expected to take place during the first 

implementation is achieved for every 

remaining implementation period, the 

State of Arkansas has not satisfied all its 

BART requirements. We are finalizing 

our disapproval of BART for NOX

(natural gas firing and fuel oil firing) 

and SO2 and PM (fuel oil firing) for Lake 

Catherine Unit 4 and BART for NOX and 

SO2 (bituminous and sub-bituminous 

coal firing) for White Bluff Units 1 and 

2. 

Comment: It appears that EPA agrees 

with the State’s approach of developing 

BART determinations for each fuelburning scenario for subject to BART 

units that are permitted to burn more 

than one type of fuel. Setting separate, 

individual BART limits for each fuel 

type that a source is physically capable 

of burning and permitted to burn is a 

generally reasonable approach to 

addressing multi-fuel units. Other 

approaches may also be reasonable if 

chosen by the State, so long as they do 

not amount to a redefinition of the 

source, as would occur if use of a 

particular fuel-type, otherwise 

permitted, were prohibited or made 

infeasible as a result of the imposition 

of a BART limit. 

Response: The EPA generally agrees 

with the State’s approach of developing 

BART determinations for each fuel 

burning scenario for subject to BART 

sources that are permitted to burn more 

than one type of fuel, as was done for 

Entergy Lake Catherine Unit 4 and 

Entergy White Bluff Units 1 and 2. 

There is nothing in the RHR or the 

BART Guidelines prohibiting a State 

from doing so. Although the BART 

Guidelines provide that we do not 

consider BART as a requirement to 

redesign the source when considering 

available control alternatives,191 we do 

note that if a State considers it 

appropriate, it may consider a fuel 

switch (i.e. switch from burning fuel oil 

to natural gas), which does not 

necessarily constitute a redesign of the 

source, as one of the options in the 

BART analysis for a particular source. 

This was done by the State of Kansas, 

which determined that a switch from 

fuel oil to natural gas satisfied the BART 

requirements for SO2 and NOX for 

Westar Energy Gordon Evans Unit 2 (the 

unit can burn both fuel oil and natural 

gas).192 The EPA approved Kansas’ 

aforementioned BART determination. 

Comment: As stated by EPA in its 

proposed action on the Arkansas RH 

SIP, neither AEP nor ADEQ performed 

a five-factor BART analysis for Flint 

Creek Boiler No. 1 (76 FR 64203). The 

company commented that since it was 

proposing to meet the presumptive 

BART limits for SO2 and NOX, it did not 

need to undertake a five-factor BART 

analysis. This does not constitute a 

proper BART analysis, and EPA was 

right in proposing disapproval of 

Arkansas’s SO2 and NOX BART 

requirements for Flint Creek. The 

presumptive limits in EPA’s BART 

Guidelines do not exempt a source from 

a five-factor BART analysis. If ADEQ or 

AEP–SWEPCO had performed a fivefactor analysis for Flint Creek, the BART 

limits would likely have been lower 

than 0.15 lbs/MMBtu for SO2 and 

0.23 lbs/MMBtu for NOX. 

Response: As explained elsewhere in 

this final rulemaking, we are finalizing 

our proposed disapproval of BART for 

NOX and SO2 for Flint Creek Boiler No. 

1 because the State did not conduct a 

five factor BART analysis for the source. 

Comment: The SO2 and NOX emission 

limits for Flint Creek Boiler No. 1 do not 

reflect the best system of continuous 


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SO2 and NOX emission reduction and 

EPA cannot find that these emission 

limits satisfy the legal BART 

requirements without a five-factor 

BART analysis. The proposed SO2

BART limit of 0.15 lbs/MMBtu for Flint 

Creek reflects only 67% removal from 

the uncontrolled 2010 average annual 

SO2 emission rate of 0.46 lbs/MMBtu. 

The best system of continuous SO2

emission reductions is a wet scrubber, 

which can achieve 95–99% removal. 

The next best system of continuous SO2

emissions reductions is a dry scrubber, 

which can achieve 90–95% SO2

removal. EPA recently proposed and 

finalized as a FIP the installation of dry 

scrubbers as BART at six coal-fired 

EGUs in Oklahoma to achieve the SO2

BART emission limit of 0.6 lbs/MMBtu 

on a 30-day rolling average basis. The 

Oklahoma units are all similar to Flint 

Creek in size and coal type. This 

provides evidence that had a proper five 

factor BART analysis been done for 

Flint Creek, the SO2 BART limit would 

have been lower than 0.15 lb/MMBtu. 

Similarly, a five-factor analysis for NOX

at Flint Creek would have required the 

evaluation of SCR and SNCR, which can 

achieve NOX emission limits lower than 

0.23 lbs/MMBtu. If SCR had been 

evaluated as BART for NOX, emissions 

would have been 78% lower, providing 

significant benefits to the State’s Class I 

areas. NOX BART emission limits as low 

as 0.5 lb/MMBtu have been promulgated 

(76 FR 52390, 52439). 

Response: The EPA agrees that we 

cannot approve the State’s BART 

determinations for SO2 and NOX for 

Flint Creek Boiler No. 1 because the 

State adopted presumptive limits as 

meeting BART for the source without 

conducting a BART five-factor analysis. 

The EPA also believes that a proper 

evaluation of the five statutory factors is 

likely to demonstrate that emission 

limits lower than the NOX and SO2

presumptive emission limits are BART 

for Flint Creek Boiler No. 1. We are 

finalizing our proposed disapproval of 

the State’s BART determinations for SO2

and NOX for Flint Creek Boiler No. 1. 

With regard to the comment that a wet 

scrubber is the ‘‘best system of 

continuous emissions reductions’’ for 

SO2 and a dry scrubber is the next ‘‘best 

system of continuous emissions 

reductions’’ for SO2, we note that 

40 CFR 51.308(e)(1)(ii)(B) directs States 

to identify the ‘‘best system of 

continuous emissions control 

technology’’ taking into account ‘‘the 

technology available, the costs of 

compliance, the energy and non-air 

quality environmental impacts of 

compliance, any pollution control 

equipment in use at the source, and the 

remaining useful life of the source.’’ 

Therefore, while we agree that a wet 

scrubber and a dry scrubber are 

generally the two most stringent control 

technologies available for control of SO2

emissions and have been found to be 

BART for many sources, we disagree 

that a wet scrubber or a dry scrubber 

will necessarily be BART in every case. 

Comment: The EPA’s proposal is 

correct that the White Bluff BART 

analyses for SO2 and NOX in the 

Arkansas RH SIP are incomplete and 

inadequate because the company only 

evaluated options to comply with the 

presumptive BART limits rather than 

evaluating emission limits reflective of 

the best system of continuous emission 

reduction at White Bluff Units 1 and 2. 

In Entergy’s 2006 BART analysis, which 

is part of the Arkansas RH SIP, the 

company did not explain why it 

proposed a 0.15 lb/MMBtu SO2

emission limit for either a wet scrubber 

or a dry scrubber, when the higher 

control efficiency associated with a wet 

scrubber would result in the ability to 

meet a lower SO2 emission limit. Also, 

the proposed SO2 BART limit of 0.15 lb/ 

MMBtu only reflects approximately 

80% control from the base case SO2

emission rates, and not the 95% and 

92% control efficiency capable of being 

achieved by a wet and dry scrubber, 

respectively. Entergy’s 2006 BART 

analysis did note that the resulting SO2

emission limit from either control 

technology would ‘‘depend on the 

future coal sulfur content’’ (see 

Appendix 9.3 of Arkansas RH SIP). 

Entergy’s revised 2008 BART analysis, 

which has not been adopted by 

Arkansas or submitted to EPA as a RH 

SIP revision, elaborated on this, 

explaining that 2 lb/MMBtu SO2 is 

assumed as the highest coal sulfur 

content for dry scrubbing and 3 lb/ 

MMBtu is assumed for wet scrubbing. 

Taking into account Entergy’s projected 

future coal sulfur content (which varies 

depending on the control technology 

used) and Entergy’s claimed percent 

removal efficiencies for the control 

technologies considered, the resulting 

emission limit just happens to equal 

EPA’s presumptive BART limit for SO2

of 0.15 lb/MMBtu. White Bluff is not 

authorized to burn coal of unlimited 

sulfur or ash content, and the higher 

uncontrolled coal sulfur content that 

Entergy assumed in its December 2006 

BART analysis (as well as in its revised 

2008 BART analysis) is prohibited from 

being utilized at the White Bluff units 

under the terms of the White Bluff 

permit. It would be virtually impossible 

for White Bluff to comply with Permit 

Condition IV.6 in its Title V permit and 

burn coal with uncontrolled SO2

emissions at the inlet to the scrubber of 

2 lb/MMBtu, much less 3 lb/MMBtu. 

The future uncontrolled SO2 emission 

rate must not be raised above the level 

of uncontrolled SO2 emissions/coal 

sulfur content authorized by the White 

Bluff permit and EPA must make clear 

that the assumed uncontrolled SO2

emission rate cannot be improperly 

inflated in proposing a BART emission 

limitation. EPA has commented on the 

BART determinations of the Wisconsin 

Department of Natural Resources as well 

as other states that BART cannot be 

based on characteristics of coal that 

might be burned in the future (see 

Exhibit 18). Instead, it is to be based on 

the fuel characteristics during the base 

case. If Entergy plans to burn higher 

sulfur coal in the future as compared to 

that utilized in the base case, that must 

be made clear in the BART analysis 

because sulfur content of coal should be 

considered in determining whether it is 

most beneficial to install a wet scrubber 

or a dry scrubber. 

Response: The EPA agrees that in its 

SO2 BART analysis for White Bluff 

Units 1 and 2, the State did not explain 

why it proposed a 0.15 lb/MMBtu SO2

emission limit for either a wet scrubber 

or a dry scrubber, when the higher 

control efficiency associated with a wet 

scrubber would result in the ability to 

meet a lower SO2 emission limit. EPA 

also agrees that the State’s proposed SO2

BART limit of 0.15 lb/MMBtu only 

reflects approximately 80% control from 

the base case SO2 emission rates, and 

not the 95% and 92% control efficiency 

capable of being achieved in many cases 

by a wet and dry scrubber, respectively. 

EPA also agrees that the BART 

Guidelines provide that BART must be 

based on the fuel characteristics during 

the base case. If a source projects that 

future operating parameters (i.e. limited 

hours of operation or capacity 

utilization, type of fuel, raw materials or 

product mix or type) will differ from 

past practice, resulting in greater (or 

less) emissions, the State must make 

this clear in the BART evaluation, as it 

may have an impact on the cost analysis 

and the ultimate selection of BART. 

Since the State did not properly 

document the cost of the SO2 control 

options considered in the BART 

analysis (including a reasonably 

detailed line by line breakdown of 

costs), we were not able to determine if 

the parameters assumed in the State’s 

cost analysis for White Bluff Units 1 and 

2 are reflective of the base case. As 

explained elsewhere in this final 

rulemaking, we are finalizing our 

proposed disapproval of SO2 BART for 


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193Appendix Y to Part 51, section IV.4. 194Appendix Y to Part 51, section III.A.2. 

Entergy White Bluff Units 1 and 2 for 

both the bituminous and subbituminous coal firing scenarios. 

Comment: The EPA’s proposed 

disapproval of the SO2, NOX, and PM 

BART determinations for fuel oil firing 

for Entergy Lake Catherine Unit 4 is 

correct because Entergy’s BART 

analyses for the fuel oil firing scenario 

are inadequate. Neither Entergy nor 

ADEQ considered and evaluated postcombustion controls for the fuel oil 

firing scenario, and Entergy improperly 

assumed only a 10% capacity factor in 

the cost-effectiveness calculations, even 

though the unit’s capacity factor is not 

limited by any enforceable requirement. 

The EPA is also correct in not allowing 

the unit to be exempt from BART for the 

fuel oil firing scenario until the Lake 

Catherine permit is revised to prohibit 

Unit 4 from burning fuel oil. 

Response: The EPA agrees that the 

State did not evaluate any SO2 postcombustion controls and did not 

properly evaluate NOX post-combustion 

controls for Entergy Lake Catherine Unit 

4 for the fuel oil firing scenario. 

Based on comments received during 

the public comment period, it has come 

to our attention that we made an error 

in our calculation of the capacity factor 

for recent years for Lake Catherine Unit 

4. Based on the information provided, 

we agree that the source has historically 

operated at less than a 10% capacity 

factor. The BART Guidelines provide 

that for the purpose of calculating the 

cost of controls, the State may calculate 

baseline emissions based upon 

continuation of past practice.193

However, as explained in more detail in 

our response to other comments and in 

our proposed rulemaking, we find that 

the State did not properly document the 

cost analysis for NOX, SO2, and PM 

controls for fuel oil firing for Entergy 

Lake Catherine Unit 4 because the 

proper documentation necessary to 

allow us to make an informed and 

proper evaluation of the BART analysis 

was not included in the SIP, as the 

BART Guidelines require. 

Therefore, we are finalizing our 

proposed disapproval of BART for NOX

for both the natural gas and fuel oil 

firing scenarios, and SO2 and PM for the 

fuel oil firing scenario. 

Comment: The EPA’s proposed 

disapproval of Arkansas’s BART 

determinations for SO2, NOX, and PM 

for AECC’s Bailey Unit 1 and McClellan 

Unit 1 is correct. ADEQ must comply 

with the requirement that once a unit is 

determined to be subject to BART, a 

BART determination must be made for 

all pollutants emitted by the source 

(see 40 CFR part 51, § 51.301 and 

Appendix Y, section IV.A). EPA must 

also disapprove the PM BART 

requirements because there was no 

determination of BART for PM2.5. 

Response: While we are finalizing our 

proposed disapproval of the State’s 

BART determinations for SO2, NOX, and 

PM for AECC’s Bailey Unit 1 and 

McClellan Unit 1, we disagree that we 

must disapprove the PM BART 

determination because the State did not 

make a BART determination for PM2.5. 

The BART Guidelines do not specify 

that States must establish a BART limit 

for both PM10 and PM2.5. The BART 

Guidelines provide the following: 

‘‘You must look at SO2, NOX, and 

direct particulate matter (PM) emissions 

in determining whether sources cause or 

contribute to visibility impairment, 

including both PM10 and PM2.5.’’ 194

This language in the BART Guidelines 

was intended to clarify to States that 

when determining whether a source is 

subject to BART, the modeling 

evaluation to determine the source’s 

impact on visibility has to account for 

both PM10 and PM2.5 emissions. There 

are several instances in which we state 

in both the preamble to the RHR, and in 

the BART Guidelines that PM10 may be 

used as indicator for PM2.5 in 

determining whether a source is subject 

to BART. Neither the RHR nor the BART 

Guidelines specify that States must 

make separate BART determinations for 

PM10 and PM2.5. Therefore, we disagree 

that we must disapprove the PM BART 

determination for AECC’s Bailey Unit 1 

and McClellan Unit 1 on the basis that 

a BART determination for PM2.5 was not 

made. 

Comment: The EPA’s proposed 

disapproval of the SO2 and NOX BART 

determinations for the Domtar Power 

Boilers No. 1 and 2 the EPA’s proposed 

disapproval of the PM BART 

determination for Domtar Power Boiler 

No. 2 are correct for the reasons given 

by EPA in its proposed rulemaking (76 

FR 64207–210). 

Response: Consistent with the 

comment, we are finalizing our 

proposed disapproval of the State’s SO2

and NOX BART determinations for the 

Domtar Power Boilers No. 1 and 2 and 

the State’s PM BART determination for 

Domtar Power Boiler No. 2 

Comment: There is significant interest 

in the application of appropriate BART 

requirements for the Flint Creek Power 

Plant, the White Bluff Steam Electric 

Station, the AECC Carl E. Bailey 

Generating Station, and the AECC John 

L. McClellan Generating Station. It is 

critical to ensure that ratepayers are not 

burdened by improper and/or 

unnecessary requirements. EPA’s 

proposed rule will impose unnecessary 

and/or improper costs and requirements 

on these and other Arkansas facilities. 

ADEQ’s original RH SIP submission 

fully met the requirements of the CAA 

and its implementing regulations. 

Response: We disagree that our final 

action will impose unnecessary and 

improper requirements on Arkansas’s 

subject to BART sources. In fact, for the 

BART determinations we are 

disapproving, we are not imposing or 

requiring a specific BART emission 

limit or cost. As explained elsewhere in 

our response to comments, our partial 

disapproval of Arkansas’s RH SIP is a 

proper exercise of our authority under 

the CAA. Our role is to review the RH 

SIP submittal and determine if the state 

met the applicable statutory and 

regulatory requirements. When 

reviewing state SIPs, we must consider 

not only whether the State considered 

the appropriate factors in making 

decisions but also whether it acted 

reasonably in doing so. Some of 

Arkansas’s BART determinations for its 

subject to BART sources, among other 

portions of the RH SIP, were not 

developed in accordance with the RHR 

and the BART Guidelines, as discussed 

in our proposed rulemaking and 

elsewhere in this final rulemaking. We 

are not imposing additional 

requirements beyond what the RHR and 

the BART Guidelines require. Therefore, 

we disagree that our proposed 

rulemaking, as finalized in this 

rulemaking, imposes unnecessary 

requirements on Arkansas’s subject to 

BART sources. 

Comment: Since limiting the sulfur 

content of fuel oil to 1.0% by weight at 

the Bailey Unit 1 and McClellan Unit 1 

is cost-effective and post-control 

modeling predicted that visibility 

impacts to Class I areas would be below 

the 0.5 dv contribution threshold, this 

control option was selected as BART. It 

is unnecessary to perform additional 

analyses for lower sulfur fuel oil for 

Bailey Unit 1 and McClellan Unit 1. 

Response: While we agree that 

limiting the sulfur content of fuel oil to 

1.0% by weight at the AECC Bailey Unit 

1 and McClellan Unit 1 is extremely 

cost-effective ($54.90/ton SO2 removed 

for Bailey Unit 1 and $158.60/ton SO2

removed for McClellan Unit1), we find 

that it is very likely that other options 

that would result in greater visibility 

improvement may also be found to be 

cost effective. According to the 

Arkansas RH SIP, the post-control 

modeling demonstrates that with the 

SO2 BART controls selected by the State 

for AECC Bailey Unit 1, the visibility 


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195See Table 9.4b of the Arkansas RH SIP. Note 

that the pre and post control visibility impact 

shown on Table 9.4b is the modeled maximum 

visibility impact at each affected Class I area. As 

explained in our proposed rulemaking, the original 

meteorological databases generated by CENRAP did 

not include observations as EPA guidance 

recommends. Therefore, in their evaluation to 

determine if a source exceeds the 0.5 dv 

contribution threshold at nearby Class I areas, states 

used the 1st high values (i.e. maximum value) of 

modeled visibility impacts instead of the 8th high 

values (i.e. 98th percentile value). The use of the 

1st high modeled values was agreed to by EPA, 

representatives of the Federal Land Managers, and 

CENRAP stakeholders. 

196See Table 9.4c of the Arkansas RH SIP. Note 

that that the pre and post control visibility impact 

shown on Table 9.4c is the modeled maximum 

visibility impact at each affected Class I area. 

197Appendix Y to Part 51, section IV. 

198 64 FR 35740. 199 70 FR 39130 and 39131. 

impact would be 0.897 dv at Caney 

Creek, 0.574 dv at Upper Buffalo, 0.809 

dv at Hercules Glades, and 0.766 dv at 

Mingo.195 According to the Arkansas RH 

SIP, the post-control modeling 

demonstrates that with the SO2 BART 

controls selected by the State for AECC 

McClellan Unit 1, the visibility impact 

would be 1.011 at Caney Creek and 

0.487 dv at Upper Buffalo.196 We note 

this constitutes approximately a 50% 

improvement in visibility across all 

areas. As such, if Arkansas conducts a 

proper five factor BART analysis that 

considers all five statutory factors and 

evaluates more stringent controls, such 

as a 0.5% or lower limit for the sulfur 

content of fuel oil used, Arkansas may 

find one or more of these more stringent 

controls to be cost-effective and result in 

even more visibility improvement than 

that resulting from the control option it 

selected. As explained in our proposed 

rulemaking, the visibility regulations 

define BART as ‘‘an emission limitation 

based on the degree of reduction 

achievable through the application of 

the best system of continuous emission 

reduction.’’ Since recent retrofits at 

existing sources provide a good 

indication of the current ‘‘best system’’ 

for controlling emissions, these controls 

must be considered in the BART 

analysis. The BART Guidelines provide 

that in identifying all options, States 

must identify the most stringent option 

(i.e. maximum level of control each 

technology is capable of achieving) as 

well a reasonable set of options for 

analysis.197 The RHR states that in 

establishing source specific BART 

emission limits, the State should 

identify and consider in the BART 

analysis the maximum level of emission 

reduction that has been achieved in 

other recent retrofits at existing sources 

in the source category.198 Fuel oil with 

a sulfur content of 0.5% by weight or 

less is being utilized in industry. In 

considering use of fuel oil with low 

sulfur content as a control option in the 

BART analysis, AECC did not identify 

and consider the maximum level of 

control achievable from the use of low 

sulfur fuel oil, and therefore, did not 

satisfy the RHR requirements. 

In addition, as pointed out in the TSD 

for our proposed rulemaking on the 

Arkansas RH SIP, even though the 

State’s cost analysis showed that wet 

scrubbers are cost-effective ($2,108.25/ 

ton SO2 removed and $1,658.32/ton SO2

removed), Arkansas did not evaluate the 

visibility impact of this control option. 

As explained in more detail elsewhere 

in our response to comments, the BART 

Guidelines require a State to evaluate all 

five statutory factors before eliminating 

a particular control option for BART.199

As articulated in our proposed 

rulemaking on the Arkansas RH SIP, the 

State must perform a cost analysis in 

which all cost estimates are properly 

documented and must evaluate the 

visibility impacts of all technically 

feasible control options considered 

before making a BART determination. 

This was not done in Arkansas’s SO2

BART analysis for the AECC Bailey Unit 

1 and McClellan Unit 1. As such, the 

BART analysis for SO2 for AECC Bailey 

Unit 1 and McClellan Unit 1 does not 

satisfy the RHR and CAA requirements. 

Therefore, we believe that it is 

necessary for Arkansas to perform 

additional analyses to evaluate the cost 

and visibility impact of using lower 

sulfur fuel oil at Bailey Unit 1 and 

McClellan Unit 1. It must also evaluate 

the visibility impact of wet scrubbers 

and any other control options 

considered in the BART analysis before 

making a BART determination. 

Comment: The results of the initial 

BART modeling performed in 2006, 

which was cumulative modeling of SO2,

NOX, and PM, indicated that both the 

AECC Bailey Unit 1 and McClellan Unit 

1 cause visibility impacts at one or more 

Class I areas. Pollutant-specific 

modeling was then performed and the 

results of the pollutant-specific 

modeling for NOX were all less than 0.5 

dv, demonstrating that NOX neither 

caused nor contributed to visibility 

impacts. For this reason, a NOX

engineering analysis was unnecessary 

and not performed. The EPA previously 

had an opportunity to comment on this 

issue about two years prior to ADEQ 

submitting its draft SIP to EPA, when 

ADEQ forwarded a question to EPA in 

an email dated October 19, 2006, asking 

whether or not five factor analyses were 

required for NOX and PM since both 

pollutants showed no impacts. No 

response to the question was ever 

received by ADEQ from EPA. 

Response: While we regret any kind of 

miscommunication or lapse of 

communication that may have occurred 

between us and Arkansas, we note that 

it is ultimately the State’s duty to make 

sure that its RH SIP satisfies all the 

regulatory and statutory requirements 

and is consistent with all applicable 

EPA guidance. As explained elsewhere 

in our response to comments, the 

pollutant-specific analysis approach for 

NOX and SO2 used to evaluate controls 

at these AECC units does not take into 

consideration the chemical interaction 

between these two pollutants and 

ammonia present in the atmosphere. A 

reduction in sulfate emissions, while 

most likely reducing visibility 

impairment overall, can result in an 

increase in visibility impairment from 

nitrate due to the increase in ammonia 

available to react with nitrate to form 

visibility impairing aerosol. The precontrol modeling results indicate that 

nitrate is a significant contributor to 

visibility impairment on some days and 

this contribution can increase under 

conditions of decreased SO2 emissions. 

Therefore, NOX and SO2 emissions 

should be modeled together and 

emission control technologies should be 

evaluated for both pollutants. We are 

finalizing our proposed disapproval of 

the State’s NOX, SO2, and PM BART 

determinations of the AECC Bailey Unit 

1 and McClellan Unit 1. 

Comment: We do not agree with 

EPA’s proposed approval of no BART 

determination for SO2 for the gas-firing 

scenario for Entergy Lake Catherine Unit 

4 (76 FR 64203–204). Once a source is 

determined to be subject to BART, a 

BART determination must be made for 

all pollutants emitted by the source (see 

40 CFR part 51, § 51.301 and appendix 

Y, section IV.A). Since the unit emits 

some SO2 when firing gas, it must be 

subject to a BART limit. EPA cannot 

exempt the unit from an SO2 BART 

analysis when firing natural gas just 

because SO2 emissions are considered to 

be low when combusting such fuel. A 

BART analysis may show that the SO2

limit currently in the Lake Catherine 

Title V permit satisfies BART, but that 

will not be known until a BART 

analysis is done. 

Response: In our review of the 

Arkansas RH SIP, we evaluated the 

determination by ADEQ that SO2

emissions when burning natural gas are 

very low and that no additional SO2

controls are required at Entergy Lake 

Catherine Unit 4. Furthermore, the 

modeling results submitted by Arkansas 

in Appendix 9.2B of the Arkansas RH 

SIP indicate that under natural gas firing 


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200 70 FR 39116. 

201 70 FR 39116. 

202 76 FR 52604 and 76 FR 80754. 

203 76 FR 16168 and 76 FR 81728. 

204A copy of the March 26, 2010, APCEC Minute 

Order granting all Arkansas subject to BART 

sources a variance from the compliance deadline 

imposed by the State’s RH Rule can be found in the 

docket associated with this rulemaking. 

205The State’s BART compliance requirements 

are found at Reg. 19.1504(B). 

conditions, NOX contributes over 99.9% 

of Lake Catherine Unit 4’s total visibility 

impacts at all nearby Class I areas on the 

most impacted days. Based on the 

State’s modeling results, the visibility 

impact of this unit from SO2 emissions 

alone is so minimal such that any 

requirement for additional SO2 controls 

on this unit would have virtually no 

visibility benefit. It is clear that the most 

effective controls to address visibility 

impairment from the source during 

natural gas firing are those that would 

reduce emissions of NOX. Therefore, in 

our proposed rulemaking, we agreed 

that it was appropriate for the State to 

not establish an SO2 BART emission 

limit (i.e. no additional controls) for the 

natural gas firing scenario. This is 

consistent with the BART Rule, which 

states the following: 

‘‘Consistent with the CAA and the 

implementing regulations, States can 

adopt a more streamlined approach to 

making BART determinations where 

appropriate. Although BART 

determinations are based on the totality 

of circumstances in a given situation, 

such as the distance of the source from 

a Class I area, the type and amount of 

pollutant at issue, and the availability 

and cost of controls, it is clear that in 

some situations, one or more factors will 

clearly suggest an outcome. Thus, for 

example, a State need not undertake an 

exhaustive analysis of a source’s impact 

on visibility resulting from relatively 

minor emissions of a pollutant where it 

is clear that controls would be costly 

and any improvements in visibility 

resulting from reductions in emissions 

of that pollutant would be negligible. In 

a scenario, for example, where a source 

emits thousands of tons of SO2 but less 

than one hundred tons of NOX, the State 

could easily conclude that requiring 

expensive controls to reduce NOX

would not be appropriate.’’ 200

Based on our analysis of the data 

submitted by ADEQ in the Arkansas RH 

SIP, and our agreement that SO2

emissions from burning natural gas are 

very low, we proposed to find that it is 

appropriate for the State to establish no 

additional control for SO2 BART. The 

BART Rule provides that states may 

determine that for a given source no 

additional control satisfies the BART 

requirement for a particular 

pollutant.201 In such cases, it is not 

necessary for a state to establish an 

emission limit when no additional 

control is BART. For example, in our 

final approval of the Kansas RH SIP, we 

approved the State’s determination that 

no additional control (and no new 

BART emission limit) for PM is BART 

for a number of sources.202 In our final 

approval of the Oklahoma RH SIP, we 

also approved the State’s determination 

that no additional control (and no new 

BART emission limit) for PM is BART 

for a number of sources.203 In the above 

cases, Kansas and Oklahoma adopted no 

new PM emission limit for PM BART, 

and we approved this based on the 

sources’ low visibility impact 

attributable to PM emissions. As such, 

our proposed approval of Arkansas’s 

determination that no additional 

controls for SO2 for the natural gas firing 

scenario satisfies SO2 BART for Lake 

Catherine Unit 4 is consistent with the 

BART Rule and consistent with our 

action on the RH SIPs of other states. 

D. Comments on the Arkansas Pollution 

Control and Ecology Commission 

Variance for Subject to BART 

Comment: The EPA cannot approve 

any of the BART determinations 

because each of the BART 

determinations is premised by Arkansas 

to implement only 5 years after EPA 

fully approves the entire RH SIP. 

Arkansas’s enforceability of BART 

requirements are codified in Chapter 15 

of Regulation No. 19 and modified in 

March 2010. Since EPA has not yet 

proposed full approval of the Arkansas 

RH SIP, EPA’s partial approval of some 

pollutant-specific BART requirements 

in Regulation No. 19 for some of 

Arkansas’s subject to BART sources will 

not meet the requirements of 40 CFR 

51.308(e)(iv). Also, the APCEC variance 

does not account for the possibility that 

EPA may impose a partial FIP for RH in 

Arkansas, and thus, under the variance, 

the backstop BART compliance 

deadline will be delayed indefinitely. 

Response: We do not believe that the 

2008 submitted Chapter 15 of APCEC 

Regulation No. 19 and its subsequent 

modification submitted to us on August 

3, 2010, creates an enforceability 

timeframe less stringent than that 

required under 40 CFR 51.308(e)(iv). We 

do not read that the partial approval of 

Arkansas BART determination means 

that the enforceability timeframe is 5 

years from the full approval of the AR 

RH SIP. Section 110(k)(3) of the 

amended Act addresses the situation in 

which an entire submittal, or a 

separable portion of a submittal, meets 

all applicable requirements of the Act. 

In the case where a separable portion of 

the submittal meets all the applicable 

requirements, partial approval may be 

used to approve that part of the 

submittal and disapprove the 

remainder. Since the portions of the RH 

SIP submittal we are approving are 

separable from the portions we are 

disapproving as explained above, each 

approved BART determination for a 

particular pollutant for a given source 

will have an enforceable date of 5 years 

from the date of EPA’s approval. If 

Arkansas fails to submit a revised RH 

SIP that is approvable for the severable 

BART determinations we are 

disapproving today, we will promulgate 

a FIP for the disapproved BART 

determinations; in that case, the 

compliance deadline will be no later 

than 5 years from the date of the FIP 

promulgation. 

As explained in our proposed 

rulemaking and as pointed out in 

another comment, the APCEC variance 

granted to Arkansas’s subject to BART 

sources on March 26, 2010, will require 

compliance with BART requirements 

‘‘as expeditiously as practicable but in 

no event later than five (5) years after 

EPA approval of the Arkansas Regional 

Haze SIP.’’ 204 As explained in our 

response to that comment, we agree that 

the APCEC variance was never 

submitted to EPA as a revision to the 

SIP. The operative rule before us is 

Chapter 15 of Regulation No. 19 (i.e. the 

State RH Rule), which requires 

compliance with BART either six years 

after the effective date of the State’s 

regulation or five years after EPA 

approval of the Arkansas RH SIP, 

whichever is first.205 Although we 

believe this timeframe is consistent with 

the requirements under 40 CFR 

51.308(e)(iv), because of the variance 

granted to all Arkansas subject to BART 

sources, the State of Arkansas no longer 

has the legal authority to enforce 

compliance within the timeframe 

required by Chapter 15 of APCEC 

Regulation No. 19, which is before us to 

act upon. Specifically, Arkansas no 

longer has the authority to enforce 

compliance with BART within six years 

after the effective date of its regulation. 

40 CFR 51.230 requires that a state must 

show it has the legal authority to 

enforce a rule that is submitted as part 

of the SIP. Therefore, we are 

disapproving the portion of the BART 

compliance provision found in the 2008 

submitted Chapter 15 of APCEC 

Regulation No. 19 that requires 

compliance with BART requirements no 

later than six years after the effective 

date of the State’s regulation. For 


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purposes of our action on the RH SIP 

submissions, we are partially approving 

and partially disapproving the portion 

of the BART compliance provision in 

Chapter 15 of APCEC Regulation No. 19, 

that requires each Arkansas subject to 

BART source to install and operate 

BART as expeditiously as practicable, 

but in no event later than five years after 

EPA approval of the Arkansas RH SIP, 

such that our disapproval is of those 

portions of the regulation that 

correspond to portions of the Arkansas 

RH SIP we are disapproving. We find 

that this is consistent with the 

requirements under 40 CFR 

51.308(e)(iv). Arkansas’s inclusion of 

the compliance provision that would 

require Arkansas subject to BART 

sources to install and operate BART no 

later than six years after the effective 

date of the State’s regulation (if such 

date takes place before five years from 

EPA approval of the Arkansas RH SIP) 

is not a required element of the Regional 

Haze SIPs to be developed and 

submitted by States pursuant to section 

169 of the CAA. Therefore, we are 

finalizing our approval of the BART 

determinations for which we proposed 

approval. 

Comment: Arkansas has not 

submitted the APCEC variance to EPA 

as part of the Arkansas RH SIP. The 

version of APCEC Regulation No. 19 

that EPA is proposing to approve 

requires compliance with BART 

emission limitations no later ‘‘than 6 

years after the effective date of [Chapter 

15 of APCEC Regulation No. 19] or five 

years after EPA approval of the 

Arkansas Regional Haze State 

Implementation Plan * * *’’ (see 

APCEC Reg. 19.1504(B) in EPA–R06– 

OAR–2008–0727–0004). Compliance 

with BART under the version of APCEC 

Reg. 19.1504(B) that has been submitted 

to EPA is required by October 15, 2013, 

yet ADEQ will have no authority to 

enforce compliance with the deadline 

that will be in effect under the version 

of APCEC Regulation No. 19 being 

proposed for approval by EPA. EPA’s 

proposed partial approval would be of 

a rule that ADEQ has no authority to 

enforce. Given that States are required 

to have legal authority to enforce the 

requirements of the SIP (see 40 CFR 

51.230(b)), EPA cannot legally approve 

the BART compliance deadline in 

APCEC Reg. 19.1504(B) until Arkansas 

properly revises its SIP to address the 

terms of the variance and submits it to 

EPA for approval. EPA seemingly 

ignores the fact that the variance was 

not adopted by the State as a SIP 

revision, was not submitted to EPA as 

a SIP revision, and is not being acted on 

by EPA in this proposed rulemaking 

action. Further, the APCEC variance 

allows for BART compliance deadlines 

less stringent than the BART 

compliance deadlines of 40 CFR 

51.308(e)(iv) of the Federal RH 

regulations because under the variance, 

compliance would not be required until 

5 years from EPA’s full approval of the 

Arkansas RH SIP. Therefore, EPA 

cannot approve any of the BART 

determinations in the Arkansas RH SIP. 

Response: As stated in our proposal, 

Chapter 15 of APCEC Regulation No. 19, 

was submitted by ADEQ on September 

23, 2008, as part of the RH SIP 

submittal. The 2008 submitted Chapter 

15 of Regulation No. 19 requires each 

subject to BART source to install and 

operate BART as expeditiously as 

practicable, but in no event later than 

six years after the effective date of 

Arkansas’s Chapter 15 of APCEC 

Regulation No. 19 or five years after 

approval of the SIP or plan revision by 

EPA, whichever comes first. ADEQ did 

revise APCEC Regulation No. 19, 

including Chapter 15, and submitted 

these changes to EPA in 2010 but this 

revised submittal did not include 

revisions to the provision for BART 

compliance timeframe. We agree with 

the comment that the APCEC variance 

that requires BART compliance as 

expeditiously as practicable but in no 

event later than five years after our 

approval of the Arkansas RH SIP has 

never been submitted to us as a revision 

to the SIP. We do not believe, however, 

this means we cannot finalize the 

approval of the BART determinations 

for which we proposed approval. We 

agree that because of the APCEC 

variance, Arkansas no longer has the 

authority to enforce compliance with 

BART within six years after the effective 

date of the State’s regulation. 40 CFR 

51.230 requires that a state must show 

it has the legal authority to enforce a 

rule that is submitted as part of the SIP. 

Therefore we are disapproving the 

portion of the BART compliance 

provision found in the 2008 submitted 

Chapter 15 of Regulation No. 19 that 

requires compliance with BART 

requirements no later than six years 

after the effective date of the State’s 

regulation. For purposes of our action 

on the RH SIP submissions, we are 

partially approving and partially 

disapproving the portion of the BART 

compliance provision that requires each 

Arkansas subject to BART source to 

install and operate BART as 

expeditiously as practicable, but in no 

event later than five years after our 

approval of the Arkansas RH SIP. We 

find that this is consistent with the 

requirements under 40 CFR 

51.308(e)(iv). Arkansas’s inclusion of 

the compliance provision that would 

require Arkansas subject to BART 

sources to install and operate BART no 

later than six years after the effective 

date of the State’s regulation (if such 

date takes place before five years from 

EPA approval of the Arkansas RH SIP) 

is not a required element of the Regional 

Haze SIPs to be developed and 

submitted by States pursuant to section 

169 of the CAA. We also note that with 

the exception of the PM BART 

determination for the Domtar Ashdown 

Mill Power Boiler No. 1, our partial 

approval of the State’s BART 

determinations is based on a finding 

that no additional control is required. 

Therefore the compliance date is not 

relevant for RH purposes since no 

additional controls would be expected 

for these sources. 

Our actions approving some BART 

determinations and disapproving some 

BART determinations for Arkansas 

sources are severable. We can approve 

some of the rules and disapprove the 

rest as long as the rules that are 

disapproved do not affect those that are 

approved. This is the case in our partial 

approval and partial disapproval action, 

in which we are disapproving the 

severable BART determinations for 

some of the units and approving the 

severable BART determinations for 

some of the units in Arkansas’s RH SIP. 

Since the portions of the RH SIP 

submittal we are approving are 

severable from the portions we are 

disapproving as explained above, each 

approved BART determination for a 

particular pollutant for a given source 

will have an enforceability of 5 years 

from the date of EPA’s approval. If EPA 

cannot approve a revised RH SIP for the 

severable BART determinations EPA is 

disapproving today before the end of the 

2 year FIP clock, EPA will promulgate 

a FIP for the severable BART 

determinations EPA is disapproving 

today. In that case, the compliance 

deadline will be as expeditious as 

practicable, but no later than 5 years 

from the date of the FIP promulgation. 

Therefore, EPA disagrees that 

compliance is required no later 5 years 

from EPA’s full approval of the entire 

Arkansas RH SIP. 

Comment: Under the Federal RH 

regulations, compliance with BART is 

required ‘‘as expeditiously as 

practicable,’’ and in no event later than 

five years after approval of the SIP (see 

40 CFR 51.308(e)(iv), and 42 U.S.C. 

7491(b)(2)(A)). However, all parties 

seem to ignore this regulatory 

requirement. Considering this regulatory 

requirement and the significant delay in 


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14656 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

206Appendix Y to Part 51, section IV.C. 

207 76 FR 25091. 

208See http://www.epa.gov/ttn/atw/utility/ 

utilitypg.html for a copy of the signed final rule. 

getting an approved RH SIP or FIP in 

place for Arkansas, EPA must consider 

tighter deadlines for BART compliance. 

Response: It is our role to determine 

if the State SIP submittal meets the 

requirements of the CAA. Only in the 

context of a FIP are we in a position to 

make our own determination about the 

appropriate compliance deadline. It is 

our expectation that the State will 

correct the deficiencies in the SIP and 

submit a revised plan that we can 

approve before the expiration of the 

mandatory FIP clock for the portions of 

the SIP we are disapproving in this final 

rulemaking action. However, if this does 

not occur and we are forced to 

promulgate a FIP, we will consider at 

such time what the appropriate 

compliance deadline is in light of the 

final BART determination. 

E. Comments on BART and the 

Forthcoming MACT Requirements 

Comment: Flint Creek Boiler No. 1 

and White Bluff Units 1 and 2 will be 

subject to EPA’s forthcoming EGU 

MACT requirements, and the BART 

Guidelines provide that MACT 

requirements should be taken into 

account in determining BART (see 40 

CFR part 51, appendix Y, section IV.C). 

The EPA has proposed a total PM limit 

for existing EGUs of 0.03 lb/MMBtu, as 

a surrogate limit for non-mercury metal 

hazardous air pollutants (HAPs) (see 76 

FR 24975). EPA should not approve the 

lax PM limit of 0.1 lb/MMBtu for Flint 

Creek Boiler No. 1 and Entergy White 

Bluff Units 1 and 2 as meeting BART for 

PM because that emission limit is much 

less stringent than the forthcoming PM 

MACT requirement. Recent stack testing 

for White Bluff Units 1 and 2 show that 

the units will not be able to meet EPA’s 

proposed mercury MACT limit for 

existing units of 1.2 lb/MMBtu. It is 

likely that both Flint Creek Boiler No. 1 

and White Bluff Units 1 and 2 will need 

to install baghouses to meet EPA’s 

mercury MACT limit for existing EGUs. 

It is well known that coal-fired boilers 

equipped with baghouses achieve better 

control of mercury than those equipped 

with ESPs. Activated carbon, a sorbent 

which adsorbs mercury, is typically 

much more effective when a baghouse is 

used compared to an ESP. According to 

EPA, the form of mercury most easily 

removed is HgCl2 and the formation of 

this compound depends on how much 

chlorine is in the coal—the lower the 

chlorine content of the coal, the less 

HgCl2 is formed. EGUs that burn low 

chlorine coal, such as Flint Creek, often 

achieve better control of mercury via 

existing SO2 scrubbers and PM controls. 

A fabric filter baghouse provides 

additional opportunities for mercury 

removal compared to a particle scrubber 

or a dry ESP. 

Response: We would like to clarify 

that the section of the BART Guidelines 

the comment refers to was not meant to 

require States to take into account 

MACT requirements in determining 

BART, but rather to provide States with 

the option to streamline the BART 

analysis for sources subject to the 

MACT standards by relying on the 

MACT standards for purposes of 

BART.206 We received the originally 

submitted Arkansas RH SIP on 

September 23, 2008 and a revision on 

August 3, 2010, while EPA proposed the 

National Emission Standards for 

Hazardous Air Pollutants from Coaland Oil-fired Electric Utility Steam 

Generating Units (EGU MACT Rule) on 

March 16, 2011.207 The EPA issued the 

EGU MACT final rule on December 16, 

2011.208 As such, it would be 

unreasonable for EPA, when taking 

action on states’ RH SIPs, to consider 

EGU MACT standards proposed years 

after a state submitted its RH SIP. This 

would potentially create an endless 

review loop for States as new MACT 

standards are issued by EPA. In 

addition, the limits in the MACT 

standards are established by EPA for 

reasons that are much different than the 

reasons for the limits established in 

Regional Haze SIPs. Our approval of 

limits on direct PM emissions in 

Arkansas for RH purposes is based on 

minimal contribution to visibility 

impairment at Class I areas and is in no 

way related to the reasons a lower 

emission limit was established under 

section 112 of the Act. Therefore, EPA 

disagrees that it should disapprove the 

PM BART limit of 0.1 lb/MMBtu 

adopted by the State for Flint Creek 

Boiler No. 1 and White Bluff Units 1 

and 2 because it is much less stringent 

than the PM emission limit in the EGU 

MACT Rule recently promulgated by 

EPA or because the sources may need to 

install baghouses to meet the mercury 

emission limit for existing EGUs in 

EPA’s EGU MACT Rule. EPA expects 

that these sources will have to comply 

with these limits under the EGU MACT 

standard as well. 

Comment: The EPA’s reason for 

proposing to approve a limit of 0.07 lb/ 

MMBtu and a wet ESP as PM BART for 

Domtar Power Boiler No. 1 is based on 

an outdated 2004 Boiler MACT PM 

standard of 0.07 lb/MMBtu and because 

according to EPA, the BART Guidelines 

provide that unless there are new 

technologies subsequent to the MACT 

standards which would lead to costeffective increases in the level of 

control, sources may rely on the MACT 

standards for purposes of BART (76 FR 

64207). EPA’s proposed approval 

ignores the fact that the 2004 MACT PM 

standard upon which the Domtar Power 

Boiler No. 1 BART determination is 

based was vacated and remanded and 

that EPA subsequently promulgated 

revised boiler MACT standards in 2011 

which were more stringent. The new 

2011 standards require existing solid 

fuel-fired boilers like Domtar’s Power 

Boiler No. 1 to meet a PM emission limit 

of 0.039 lb/MMBtu on a 30-day rolling 

average, which is 44% lower than the 

vacated 2004 0.07 lb/MMBtu PM MACT 

limit (76 FR 15608, 15689 at Table 2). 

Even though EPA has delayed the 

effective date of the new 2011 Boiler 

MACT rule until completion of 

reconsideration of the rule and recently 

reissued a reconsideration proposal, 

there is no legitimate legal basis in the 

applicable regulations for exempting 

sources from a five-factor BART analysis 

based on their meeting an outdated and 

formally vacated PM MACT standard as 

reflecting BART when that MACT 

standard has been replaced with a more 

stringent proposed MACT standard. 

EPA should disapprove the PM BART 

determination for Power Boiler No. 1 

either because it is less stringent than 

required by the MACT standards for PM 

currently being proposed by EPA or 

because there was no five-factor 

evaluation for BART for PM. 

Response: The EPA acknowledges 

that on June 8, 2007, the United States 

Court of Appeals for the District of 

Columbia Circuit vacated and remanded 

the national emission standards for 

hazardous air pollutants for new and 

existing industrial/commercial/ 

institutional boilers and process heaters 

(i.e. the 2004 Boiler MACT Rule) 

promulgated by EPA on September 13, 

2004. However, it should be noted that 

the effective date of this vacatur was 

July 30, 2007, which was after the close 

of the public notice and comment 

period for Arkansas’s proposed RH 

Rule, which codifies all the BART 

determinations made by the State. On 

March 21, 2011, the EPA issued a final 

rule to regulate emissions of hazardous 

air pollutants (HAPs) from industrial, 

commercial, and institutional boilers 

and process heaters located at major 

sources of HAP emissions (i.e. the 

‘‘Major Source Boiler MACT,’’ or Boiler 

MACT Rule). As noted in the comment, 

the Major Source Boiler MACT Rule 

established a PM emission limit of 0.039 

lb/MMBtu on a 30-day rolling average 


pmangrum on DSK3VPTVN1PROD with RULES_2
Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14657 

209 76 FR 28662. 

210 76 FR 80598. 

211Appendix Y to Part 51, section IV.C. 

212These documents can be found in the docket 

for our rulemaking. 

that applies to existing boilers designed 

to burn solid fuel, such as the Domtar 

Ashdown Mill Power Boiler No. 1. 

However, EPA promulgated the Major 

Source Boiler MACT Rule years after the 

end of the State’s public notice and 

comment period and years after the date 

of Arkansas’s submission to EPA of the 

RH SIP. As such, it would be 

unreasonable to disapprove the State’s 

PM BART determination for Domtar on 

the basis that it is less stringent than the 

emission limit in the Major Source 

Boiler MACT Rule issued by EPA on 

March 21, 2011. Furthermore, on May 

18, 2011, EPA published a final rule 

delaying the effective date for the Major 

Source Boiler MACT Rule until the 

proceedings for judicial review of the 

rule is completed or the EPA completes 

its reconsideration of the rule, 

whichever is earlier.209 And on 

December 2, 2011, EPA issued a 

proposed rule for reconsideration of the 

final Major Source Boiler MACT 

Rule.210 The proposed rule for 

reconsideration and the uncertainty 

surrounding the Major Source Boiler 

MACT Rule is another reason why it is 

unreasonable for EPA to disapprove the 

State’s PM BART determination for 

Domtar on the basis that it is less 

stringent than the emission limit in the 

2011 Major Source Boiler MACT Rule. 

With regard to the comment that EPA 

should disapprove the State’s PM BART 

determination for Domtar Power Boiler 

No. 1 because there was no five-factor 

evaluation for BART for PM, EPA holds 

that the State did not conduct a BART 

analysis for PM for Domtar Power Boiler 

No. 1 because at the time of the State’s 

analysis, it was relying on the MACT 

standards for purposes of BART. 

Furthermore, the comment disregards 

the reason why the BART Guidelines 

provide that States could take a 

streamlined BART approach for sources 

subject to MACT standards. The BART 

Guidelines provide the following: 

‘‘Any source subject to MACT standards 

must meet a level that is as stringent as the 

best controlled 12 percent of sources in the 

industry * * * We believe that, in many 

cases, it will be unlikely that States will 

identify emission controls more stringent 

than the MACT standards without 

identifying control options that would cost 

many thousands of dollars per ton.’’ 211

Accordingly, the reason why the 

BART Guidelines anticipated that states 

could streamline their analysis by 

relying on the MACT standards for 

purposes of BART is because EPA 

believes that such controls are among 

the most stringent available and that 

emission controls more stringent than 

this are very likely not cost-effective. 

Notwithstanding the court’s vacatur of 

the 2004 Boiler MACT Rule, at the time 

Arkansas performed its analysis and 

adopted the 0.07 lb/MMBtu emission 

limit for PM BART for the Domtar 

Ashdown Mill Power Boiler No. 1 based 

on the 2004 Boiler MACT PM standard, 

the emissions controls reflected by that 

PM standard were among the most 

stringent controls available at that time 

and emission controls more stringent 

than this were at that time likely not 

cost-effective for purposes of addressing 

visibility. Therefore, EPA disagrees that 

we should disapprove the PM BART 

determination for the Domtar Ashdown 

Mill Power Boiler No. 1. 

F. Comments on Modeling 

Comment: ADEQ conducted precontrol CALPUFF modeling to show 

that PM10 and PM2.5 emissions from 

AEP Flint Creek No. 1 Boiler have 

minimal visibility impacts. The EPA 

utilized modeling results to exempt 

White Bluff Units 1 and 2 from a PM 

BART analysis, while ADEQ and 

Entergy exempted the units from a PM 

BART analysis based on their belief that 

most of the visibility-causing emissions 

from Units 1 and 2 are due to SO2 and 

NOX while PM10 emissions are wellcontrolled with existing electrostatic 

precipitators (ESPs). The existing PM 

emission limit of 0.1 lbs/MMBtu, which 

ADEQ adopted as BART for PM, fails to 

reflect the best system of continuous 

particulate matter reduction at the 

White Bluff units, especially if Entergy 

is considering the installation of a dry 

scrubber and baghouse at each White 

Bluff unit to meet BART. 

In addition, the impact threshold used 

in this analysis is problematic because 

it is likely that ADEQ applied a 0.5 dv 

threshold, although the discussion in 

the Arkansas RH SIP on the modeling is 

limited or not present. Given the 

number of sources impacting visibility 

at Class I areas, a 0.5 dv threshold is not 

appropriate for one visibility impairing 

pollutant. The RHR and BART 

Guidelines do not provide for 

exempting a source from BART for one 

visibility impairing pollutant. A BART 

determination must be made for each 

pollutant and EPA cannot exempt Flint 

Creek Boiler No. 1 and White Bluff 

Units 1 and 2 from a BART analysis for 

PM based on modeling that shows that 

PM visibility impacts do not trip the 

BART impact threshold. 

Furthermore, the PM modeling used 

to exempt the source from a PM BART 

determination utilized an emission rate 

much lower than the proposed BART 

limit. The pre-control modeling for Flint 

Creek included the 24-hr actual 

maximum emissions rate, which is 70% 

lower than the proposed BART limit of 

0.1 lbs/MMBtu. ADEQ modeled White 

Bluff Unit 1’s highest 24-hour actual 

PM10 emission rate of 15.592 grams per 

second and White Bluff Unit 2’s highest 

24-hour actual PM10 emission rate of 

16.653 grams per second in determining 

whether the plant’s emissions were 

subject to BART, which is 85% lower 

than the proposed BART limit of 0.1 

lbs/MMBtu. The emission limits in the 

April 2007 ENVIRON Report titled 

‘‘Cumulative Modeling of Subject to 

Best Available Retrofit Technology 

(BART) Facilities as a Requirement of 

ADEQ’s BART Modeling Protocol’’ 

(Appendix 9.2D of the Arkansas RH SIP) 

are even lower than those used in the 

pre-control modeling. 

Response: In our review of the 

Arkansas RH SIP, we evaluated the 

determination by ADEQ that no 

additional PM controls are required for 

the AEP Flint Creek Boiler No. 1 and the 

Entergy White Bluff Units 1 and 2. In 

the case of Flint Creek, ADEQ’s 

determination was based on the precontrol modeling performed by ADEQ 

and a review of AEP SWEPCO’s 

statement that the PM visibility 

modeling did not ‘‘trip the BART impact 

threshold.’’ We reviewed the pre-control 

modeling preformed using the 24-hr 

actual maximum emissions from the 

baseline period. The modeling results in 

Appendix 9.2B of the AR RH SIP and 

presented in Table 7–6 of Appendix A 

of the TSD,212 indicate that PM 

contributes less than 0.5% of the total 

visibility impacts from Flint Creek 

Boiler No. 1 at all nearby Class I areas 

with the exception of Upper Buffalo. PM 

contributions to visibility impacts at 

Upper Buffalo from Flint Creek are less 

than 2% of the total visibility 

impairment at this Class I area. On the 

most impacted day at Upper Buffalo, 

modeling the 24-hr actual maximum 

emissions, PM contributes only 0.07 dv 

of the total 3.781 dv modeled visibility 

impact from the source. Clearly, the 

most effective controls to address 

visibility impairment from the source 

are those that would reduce emissions 

of visibility impairing pollutants other 

than direct emissions of PM. 

For Entergy White Bluff units 1 and 

2, we reviewed the data submitted by 

ADEQ, including pre-control modeling 

in Appendix 9.2B of the Arkansas RH 

SIP, to evaluate ADEQ and White Bluff’s 

determination that the majority of 

visibility-causing emissions are due to 


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14658 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

213 70 FR 39116. 

emissions of NOX and SO2, and that no 

additional PM controls are warranted. 

The modeling results in Appendix 9.2B 

of the Arkansas RH SIP and presented 

in Table 7–7 of Appendix A of the TSD, 

indicate that PM contributes less than 

0.4% of the total visibility impacts at all 

nearby Class I areas. On the most 

impacted day at Caney Creek, modeling 

the 24-hr actual maximum emissions, 

PM contributes only 0.03 dv of the more 

than 8 dv modeled visibility impact 

from the White Bluff Units 1 and 2. 

Clearly, the majority of visibilitycausing emissions are due to emissions 

of NOX and SO2 and the most effective 

controls to address visibility 

impairment from the units are those that 

would reduce emissions of NOX and 

SO2 rather than direct emissions of PM. 

In this action, we are finalizing our 

proposal to disapprove the NOX and 

SO2 BART determinations for these 

units as ADEQ did not properly evaluate 

and identify controls to address 

visibility impairment from these units. 

In both cases, it is clear that the 

visibility impact from PM emissions 

alone is so minimal such that the 

installation of any additional PM 

controls on these units (including any 

upgrades to the existing controls) could 

only have minimal visibility benefit and 

therefore would not be justified. This is 

in keeping with the BART Rule, which 

states the following: 

‘‘Consistent with the CAA and the 

implementing regulations, States can adopt a 

more streamlined approach to making BART 

determinations where appropriate. Although 

BART determinations are based on the 

totality of circumstances in a given situation, 

such as the distance of the source from a 

Class I area, the type and amount of pollutant 

at issue, and the availability and cost of 

controls, it is clear that in some situations, 

one or more factors will clearly suggest an 

outcome. Thus, for example, a State need not 

undertake an exhaustive analysis of a 

source’s impact on visibility resulting from 

relatively minor emissions of a pollutant 

where it is clear that controls would be costly 

and any improvements in visibility resulting 

from reductions in emissions of that 

pollutant would be negligible. In a scenario, 

for example, where a source emits thousands 

of tons of SO2 but less than one hundred tons 

of NOX, the State could easily conclude that 

requiring expensive controls to reduce NOX

would not be appropriate. In another 

situation, however, inexpensive NOX

controls might be available and a State might 

reasonably conclude that NOX controls were 

justified as a means to improve visibility 

despite the fact that the source emits less 

than one hundred tons of the pollutant.’’ 213

In reviewing the State’s PM BART 

determinations for Flint Creek Boiler 

No. 1 and White Bluff Units 1 and 2, we 

utilized ADEQ’s pre-control screening 

modeling using 24-hr maximum actual 

emissions from the baseline period as 

recommended in the BART guidelines. 

We did not rely on the cumulative 

modeling results found in Appendix 

9.2D of the AR RH SIP in our review of 

ADEQ’s PM BART determination for 

sources at these two facilities. Based on 

our analysis of the data submitted by 

ADEQ in the Arkansas RH SIP, we find 

that no additional controls are required 

for PM and therefore are finalizing our 

proposal to find that the existing PM 

emission limits are acceptable to satisfy 

the PM BART requirements of Flint 

Creek Boiler No. 1 and White Bluff 

Units 1 and 2. 

Comment: Even though the modeling 

for Entergy’s White Bluff Units 1 and 2 

deviated from the standard modeling 

protocol in evaluating wet and dry 

scrubbers, these deviations did not 

impact the BART analysis and 

subsequent BART determination for 

these units. The use of the 8th highest 

day rather than the maximum visibility 

impact did not impact the BART 

determination because the units were 

still determined to be subject-to-BART 

and the BART decision was not based 

upon modeling. Therefore, ADEQ’s 

acceptance of the modeling should be 

approved by EPA. 

Response: The modeling conducted 

for Entergy White Bluff Units 1 and 2 

was not conducted appropriately for its 

purpose and affected the BART analysis 

and subsequent BART determinations 

for these units. The modeling for wet 

and dry scrubbers at Entergy’s White 

Bluff units 1 and 2 evaluated both 

control technologies at an emission 

limit of 0.15 lb/MMBtu for SO2. 

However, wet scrubbers and dry 

scrubbers are capable of achieving a 

lower emission limit than was modeled 

by ADEQ, and similar facilities use 

these controls to control SO2 emissions 

below the 0.15 lb/MMBtu limit included 

in the analysis. The lowest emission 

limit achievable must be included in the 

BART analysis. ADEQ evaluated the 

control effectiveness of the two control 

options of wet and dry scrubbing, 

stating the wet scrubber can achieve up 

to 95% control efficiency while the dry 

scrubber can achieve up to 92% control 

efficiency. An emission limit of 0.15 

lbs/MMBtu represents a control 

efficiency of only approximately 80% at 

White Bluff Units 1 and 2. Therefore, 

the visibility modeling is flawed 

because it did not evaluate the level of 

visibility improvement reasonably 

achievable due to the use of these 

technologies at the emission rate these 

technologies are capable of achieving. 

Furthermore the original 

meteorological databases generated by 

CENRAP did not include observations 

as our guidance recommends. The use 

of meteorological databases that do not 

include observations may lead, to less 

conservatism in the CALPUFF modeled 

visibility results compared with 

modeling that uses meteorological 

databases with observations. To account 

for this, the use of the 1st High 

modeling values rather than 8th high 

modeling values was agreed to by EPA, 

representatives of the Federal Land 

Managers, and CENRAP stakeholders. 

The modeling conducted for Entergy’s 

White Bluff Units 1 and 2 deviated from 

this accepted modeling protocol by 

using the 8th highest day rather than the 

maximum impacted day and failed to 

account in any other way for the loss in 

conservatism that results from using the 

CENRAP database that does not include 

observations. In summary, an 

approvable visibility analysis would 

follow the agreed upon modeling 

protocol for BART and evaluate the 

visibility benefits for the lowest 

emission limit achievable by each 

technologically feasible control as 

required by the RHR. 

Comment: We agree with EPA’s 

finding that the visibility impact 

analysis of the SO2 control options for 

Entergy White Bluff Units 1 and 2 was 

not properly conducted because ADEQ’s 

modeling for White Bluff Units 1 and 2 

considered both wet and dry scrubbers 

at the same emission rate of 0.15 lb/ 

MMBtu rather than modeling the 

emission rates that these technologies 

are capable of achieving. In addition, 

the modeling for Entergy’s White Bluff 

Units 1 and 2 deviated from ADEQ’s 

modeling protocol by using the 98th 

percentile value of visibility impacts 

rather than the highest day of impacts. 

Response: As explained elsewhere in 

our response to comments, we find that 

the visibility impact analysis of the SO2

control options for the White Bluff units 

1 and 2 was not properly conducted 

because ADEQ’s modeling for White 

Bluff Units 1 and 2 considered both wet 

and dry scrubbers at the same emission 

rate of 0.15 lb/MMBtu rather than 

modeling the emission rates that these 

technologies are capable of achieving. 

We find that ADEQ’s modeling for 

Entergy’s White Bluff Units 1 and 2 

deviated from ADEQ’s modeling 

protocol by using the 98th percentile 

value of visibility impacts rather than 

the highest day of impacts. 

Comment: ADEQ performed the 

BART determination modeling in 

accordance with the guidance provided 

by EPA. ADEQ modeled SO2 and NOX

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pmangrum on DSK3VPTVN1PROD with RULES_2
Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14659 

214BART Guidelines; Memo from Joseph Paisie 

(Geographic Strategies Group, OAQPS) to Kay 

Prince (Branch Chief EPA Region 4) on Regional 

Haze Regulations and Guidelines for Best Available 

Retrofit Technology (BART) Determinations, July 

19, 2006; EPA Q and A—September 26, 2006. 

control. Modeling results showed the 

pollutant that impacted visibility was 

SO2 and not NOX. Utilizing this 

information and in compliance with the 

EPA’s BART Guidelines, ADEQ did not 

make BART determination for that 

source or group of sources (or for certain 

pollutants for those sources) when 

ADEQ’s analysis showed that an 

individual source or group of sources 

(or certain pollutants from those 

sources) is not reasonably anticipated to 

cause or contribute to any visibility 

impairment in a class I area. 

Response: We agree that ADEQ precontrol and post-control modeling was 

performed modeling all pollutants 

(NOX, SO2, and PM) together. We note 

that to properly evaluate the visibility 

benefit from a control, NOX and SO2

emissions should be modeled together. 

It is unclear which facility the 

comment is referring to regarding ADEQ 

not making a BART determination for 

NOX based on modeling that showed 

SO2 impacted visibility and not NOX. 

ADEQ did make NOX BART 

determinations for all but two subjectto-BART sources. Our concerns with 

these BART determinations are 

discussed in detail in a separate 

response to comment. 

For AECC Bailey Unit 1 and AECC 

McClellan Unit 1, ADEQ determined, 

based on pollutant-specific modeling 

performed subsequent to the initial precontrol screening modeling, that NOX

contributions were less than the 0.5 dv 

threshold and, as a result, incorrectly 

determined a NOX BART determination 

was not needed for these two units. 

ADEQ made a NOX BART determination 

for all other sources they determined to 

be subject-to-BART. In the case of the 

two AECC units, as stated in our 

proposal, our evaluation of the 

screening modeling results for these 

units reveals that on some of the most 

impacted days, nitrate is a significant 

contributor to the visibility impairment 

due to these units. Post-control 

modeling performed by ADEQ, applying 

the use of 1% sulfur fuel, show that 

these units would continue to cause or 

contribute to visibility impairment at a 

number of Class I areas, with NOX

emissions responsible for over 50% of 

the impairment on some days under this 

control scenario. The pollutant-specific 

analysis approach for NOX and SO2

used to evaluate controls at these AECC 

units does not take into consideration 

the chemical interaction between these 

two pollutants and ammonia present in 

the atmosphere. A reduction in sulfate 

emissions can result in an increase in 

visibility impairment from nitrate due to 

the increase in ammonia available to 

react with nitrate to form visibility 

impairing aerosol. The pre-control 

modeling results indicate that nitrate is 

a significant contributor to visibility 

impairment on some days and this 

contribution can increase under 

conditions of decreased SO2 emissions. 

Therefore, NOX and SO2 emissions 

should be modeled together and 

emission control technologies should be 

evaluated for both pollutants. In light of 

the relatively high impacts due to 

nitrate, a combination of NOX and SO2

controls may prove to be cost-effective 

and provide for substantial visibility 

improvement and must therefore be 

evaluated. We further discuss the 

importance of evaluating all the 

emissions (NOX, SO2, and PM) together 

from BART sources when assessing the 

benefit in visibility impairment from 

reductions of NOX and/or SO2 in 

another response to comment and also 

in past EPA guidance.214

Comment: The EPA is inconsistent in 

its approach to the contribution 

threshold to visibility impairment. The 

EPA initially approved ADEQ’s 

selection of a threshold of 0.5 dv in the 

Arkansas RH SIP. However, the EPA 

later on states that a lower threshold 

value is needed in evaluating pollutantspecific modeling for sources that emit 

more than one visibility impairing 

pollutant. Arkansas properly modeled 

the visibility impacts of NOX and SO2

emissions separately from one another. 

Arkansas’s application of the 0.5 dv 

threshold in considering the impacts of 

NOX, SO2, and PM on a per-pollutant 

basis is consistent with the BART 

Guidelines. The EPA argues that the 0.5 

dv threshold in the BART Guidelines 

applies to all three visibility impairing 

pollutants combined, and requires the 

state to lower the threshold value in 

evaluating pollutant-specific modeling 

for sources that emit more than one 

visibility impairing pollutant. This is 

unsupported as a legal, factual, and 

policy matter, and it is unclear what 

EPA actually expects states to do on this 

issue. 

The EPA’s proposed rule does not 

provide any guidance on EPA’s views as 

to how Arkansas and other states should 

modify the 0.5 dv threshold to account 

for separate modeling of PM, on the one 

hand, and NOX and SO2, on the other 

hand. The EPA cannot reasonably 

purport to require the state to apply a 

new, untested, and previously 

unarticulated standard in its BART 

analyses if it does not provide guidance 

on how it should do so. Consistent with 

the 2006 EPA memorandum cited by 

EPA in its proposal, it is believed that 

numerous BART contribution analyses 

separating PM from NOX and SO2 have 

been performed without revising the 0.5 

dv contribution threshold on this basis 

alone. EPA has not previously stated or 

suggested that any such revision is 

necessary and there is no basis for any 

suggestion that such a revision is 

necessary. EPA should recognize that 

states may use the default 0.5 dv 

contribution threshold and allow the 

application of this threshold regardless 

of how pollutants are modeled. EPA’s 

proposed new approach needlessly 

complicates the analysis, is 

inappropriate and unsupported, and 

should be withdrawn. ADEQ’s selection 

of a threshold of 0.5 dv is reasonable 

and appropriate, and should be 

approved by EPA. 

Response: We reviewed ADEQ’s 

methodology to initially identify which 

sources were subject-to-BART. This 

methodology included modeling all 

pollutants together and applying a 

contribution threshold of 0.5 dv. As 

discussed in our proposed rule, we 

agree with ADEQ’s selection of the 0.5 

dv threshold as it applies to the initial 

screening modeling performed by ADEQ 

when all three pollutants, NOX, SO2 and 

PM are considered together. 

We disagree with the characterization 

of the 0.5 dv threshold as a default 

value. The BART Guidelines state that 

‘‘the appropriate threshold for 

determining whether a source 

contributes to visibility impairment’ 

may reasonably differ across states,’’ 

but, ‘‘[a]s a general matter, any 

threshold that you use for determining 

whether a source ‘contributes’ to 

visibility impairment should not be 

higher than 0.5 deciviews.’’ 70 FR 

39104, 39161. The 0.5 dv threshold is 

not set as a default value but rather a 

ceiling to what may be determined to be 

appropriate in any situation. Further, in 

setting a contribution threshold, the 

BART Guidelines say that states should 

‘‘consider the number of emissions 

sources affecting the Class I areas at 

issue and the magnitude of the 

individual sources’ impacts.’’ 70 FR 

39104, 39161. The BART Guidelines 

affirm that states are free to use a lower 

threshold if they conclude that the 

location of a large number of BARTeligible sources in proximity of a Class 

I area justifies this approach. 

The pollutant-specific approach is 

acceptable only for PM BART 

contribution analyses. Furthermore, as 


pmangrum on DSK3VPTVN1PROD with RULES_2
14660 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

215Memo from Joseph Paisie (Geographic 

Strategies Group, OAQPS) to Kay Prince (Branch 

Chief EPA Region 4) on Regional Haze Regulations 

and Guidelines for Best Available Retrofit 

Technology (BART) Determinations, July 19, 2006. 

216BART Guidelines; Memo from Joseph Paisie 

(Geographic Strategies Group, OAQPS) to Kay 

Prince (Branch Chief EPA Region 4) on Regional 

Haze Regulations and Guidelines for Best Available 

Retrofit Technology (BART) Determinations, July 

19, 2006; EPA Q and A—September 26, 2006 217 Ibid. 

stated in the 2006 EPA memorandum215

referenced in the comment, using 

CALPUFF on a pollutant-specific basis 

for PM is only appropriate in certain 

situations, such as if a State chooses to 

adopt the Clean Air Interstate Rule 

(CAlR) program/CSAPR to address 

emissions of SO2 and NOX from EGUs. 

In such an instance, the CAIR/CSAPR 

may satisfy the requirements for BART 

for these pollutants from these sources. 

However, the State must determine 

whether its BART-eligible EGUs are 

subject to review under BART for direct 

emissions of PM. 

Arkansas did not rely on CAIR to 

address emissions of SO2 and NOX. 

Therefore, pollutant specific analysis is 

not appropriate for a single source 

analysis. For non-CAIR situations, it is 

necessary to model the source’s total 

emissions (NOX and SO2) in any 

CALPUFF modeling to estimate 

visibility impairment or change in 

visibility impairment from the potential 

installation of controls or no controls. 

Separate pollutant-specific analyses for 

NOX and SO2 do not take into 

consideration the chemical interaction 

in the atmosphere. Such modeling does 

not take into account the competition/ 

balance of these two pollutants 

chemical reactions with ammonia 

present in the atmosphere. A reduction 

in sulfate emissions can result in an 

increase in visibility impairment due to 

nitrate due to the increase in ammonia 

available to react with nitrate to form 

visibility impairing aerosol. Therefore, 

NOX and SO2 emissions should be 

modeled together and emission control 

technologies should be evaluated for 

both pollutants.216

ADEQ’s approach to modeling a 

single source on a pollutant specific 

basis could allow for a BART applicable 

source to model below 0.5 for each of 

the pollutants individually (NOX, SO2, 

and PM), which could lead to a 

potential cumulative impact of up to 

1.47 dv (3 x 0.49 dv) and yet the source 

would not be evaluated for controls. 

This process would allow a 

determination to be made in this 

maximum hypothetical case that a 1.47 

dv impact from a subject to BART 

source, which is above the 1.0 dv 

impact that would result in the source 

causing a significant visibility 

impairment, would ‘‘screen’’ out of a 

full BART analysis using ADEQ’s 

approach. This is not appropriate and is 

inconsistent with our BART Guidelines 

and guidance. In evaluation of 

pollutant-specific impacts from a source 

(i.e. visibility impacts from PM 

emissions), consideration of the amount 

of visibility impairment contribution 

from a source’s PM emissions can be 

evaluated against the visibility 

impairment contribution from the 

source’s combined NOX and SO2

emissions.217

EPA also disagrees that we have 

developed or implemented any new 

guidance in our proposal. EPA’s 

approach is based on the 2005 BART 

guidelines, and additional guidance 

provided in 2006. 

Comment: Although the use of daily 

maximum emissions for BART 

modeling purposes meets the modeling 

protocol, this protocol should be 

revisited due to the fact that using daily 

maximum emissions is completely 

unrealistic and overly conservative in 

most cases, as it assumes that such an 

emission rate occurs every day for three 

years. This is especially overly 

conservative for Unit 1 of the Carl E. 

Bailey Generating Station and Unit 1 of 

the John L. McClellan Generation 

Station, as these units primarily fire 

natural gas and have rarely fired fuel oil 

over the past few years. With upcoming 

EPA environmental regulations such as 

the Utility MACT Rule being 

promulgated, these units are likely to 

continue the trend of low capacity 

factors of fuel use. Any controls 

required to be implemented on these 

units will only be used 5% or less of the 

time, and it is certainly not costeffective. Logic and practicality dictate 

that the minimal use of fuel oil at these 

two units requires an accommodation in 

this instance. 

Response: We agree that the modeling 

protocol and the BART Guidelines state 

that the daily maximum emissions 

should be used for modeling visibility 

impacts during the baseline period. We 

note that the BART Guidelines do allow 

for consideration of limited operation of 

a source or fuel type. Given that there 

are no permit requirements in place that 

would limit the time of operation of the 

AECC units when burning fuel oil, the 

facilities can legally be operated well 

above the 5% capacity factor that AECC 

assumes it will be operating under in 

the future. It is likely that if the fuel oil 

burning capacity of these units is 

significantly limited, installation of 

controls to address the emissions during 

fuel oil burning would prove to be not 

cost-effective on a dollar per ton 

removed basis. A federally enforceable 

limit must be in place that can be relied 

upon to limit the emissions of the 

source during fuel oil burning scenarios. 

We are disapproving the SO2 BART 

analysis for these two units because 

ADEQ did not consider the option of 

burning fuel oils with sulfur content 

less than 1.0%. As articulated in our 

proposal, the use of fuel oil with a 0.5% 

sulfur content or lower is technically 

feasible and ADEQ should have 

evaluated its cost effectiveness and 

visibility impact for the AECC Bailey 

Unit 1 and the AECC McClellan Unit 1. 

Alternatively, an operating air permit 

restriction to use only natural gas as the 

fuel source for the two units or 

significantly restricting fuel oil burning 

may be acceptable. 

At this time, it is speculation to 

assume that the future amended MACT 

rule will lower the capacity factors of 

fuel use for sources. When evaluating a 

state’s BART determination, the EPA 

looks at existing requirements and 

cannot rely on potential future actions 

in its decision to approve or disapprove 

a state SIP. ADEQ cannot rely on a 

future MACT Rule to limit the capacity 

factor of fuel oil use. 

Comment: All post-control CALPUFF 

modeling completed in Domtar’s 

analysis was cumulative-type modeling, 

taking into account all pollutants—NOX, 

SO2, and PM10 in each analysis. The 

EPA needs to list in detail any concerns 

about the methods used to complete 

modeling analysis of Domtar’s facility. 

Response: We agree with the 

commenter that post-control modeling 

for the Domtar facility was performed 

modeling all visibility impairing 

pollutants together (SO2, NOX and PM). 

As discussed in the proposed action, we 

are finding the chosen model and the 

general modeling methodology used by 

ADEQ to be acceptable. Because 

Domtar’s visibility modeling was 

performed following the ADEQ 

modeling protocol, we also find that the 

modeling methodology followed by 

Domtar is acceptable. However, the 

BART determinations made for the 

subject-to-BART units at the Domtar 

facility were performed without 

evaluating the visibility improvement 

anticipated due to the use of all 

technically feasible control options. 

Visibility modeling was performed only 

after a control technology was selected 

as BART. This approach is unacceptable 

and does not allow for a comparison of 

the effectiveness of available controls in 

reducing visibility impacts to be 

considered as part of the BART 

determination. ADEQ’s and Domtar’s 

BART determinations were flawed 


pmangrum on DSK3VPTVN1PROD with RULES_2
Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 14661 

218See 40 CFR 51.308(e)(1)(ii)(A) and 42 U.S.C. 

7491(g)(2). 

219Appendix Y to Part 41, section IV.D. 

220 64 FR 35740. 

221Regulatory version that had been approved by 

EPA for assessing Long Range Transport of primary 

pollutants. Final BART guidelines published July 6, 

2005. (70 FR 39104–39172). 

222 ‘‘Most important, the simplified chemistry in 

the model tends to magnify the actual visibility 

effects of that source. Because of these features and 

the uncertainties associated with the model, we 

believe it is appropriate to use the 98th percentile— 

a more robust approach that does not give undue 

weight to the extreme tail of the distribution.’’ 70 

FR 39104, 39121. 

223As discussed in detail in a separate response 

to comment, because the CENRAP meteorological 

databases used in the CALPUFF modeling analyses 

do not include observations, the use of the 

maximum impact rather than the 98th percentile 

was agreed upon. The use of meteorological 

databases that do not include observations may 

lead, in some applications, to potentially less 

conservatism in the CALPUFF modeled visibility 

results compared with modeling that uses 

meteorological databases with observations. The 

use of the 1st High modeling values was agreed to 

by EPA, representatives of the Federal Land 

Managers, and CENRAP stakeholders to account for 

this. 

because the modeling did not evaluate 

all technically feasible control options 

or evaluate the control technology at the 

control efficiencies they are capable of 

achieving to inform the BART 

determination. We note, that to properly 

evaluate the visibility benefit from each 

control, NOX and SO2 emissions must 

be modeled together for each control 

scenario examined, similar to the 

modeling performed in the post-and 

pre-control modeling scenarios. 

Comment: The EPA cannot rely on 

post-control modeling to justify the 

requirement to evaluate postcombustion controls for NOX in the 

agency’s disapproval of the BART 

determinations for Entergy’s White Bluff 

facility. While EPA states that postcontrol modeling shows continued postcontrol modeled visibility impairment 

due to NOX emissions, the models, 

including CALPUFF, significantly 

overstate nitrate-caused RH, and 

reliance on those models is not a 

credible approach. Even EPA 

acknowledges that the CALPUFF model 

tends to magnify the actual visibility 

effects of an individual source and the 

CALPUFF model is less advanced than 

some of the recent atmospheric 

chemistry simulations. A more recent 

version of CALPUFF tends to reduce the 

nitrate over prediction using more 

advanced chemistry modules borrowed 

from regional models such as CAMx and 

CMAQ, but this version has not been yet 

approved by EPA. Because there is not 

a credible version of CALPUFF with 

adequate chemistry to assess the 

visibility impact of Arkansas NOX

emissions in an unbiased manner, it is 

helpful to look at actual monitoring data 

taken at IMPROVE sites and to keep in 

mind that the nitrate chemistry and the 

IMPROVE monitoring data indicate that 

NO3 particulate formation tends to 

occur on the coldest days, while on 

warmer days, invisible HNO3 vapor 

formation is preferred, which has no 

visibility impact. The Arkansas sources 

that affect the class I areas subject to this 

rule are south and east of the areas, 

which are generally not associated with 

the coldest conditions when the worst 

nitrate haze is observed to actually 

occur. 

Response: We disagree that we relied 

on post-control modeling to justify the 

requirement to evaluate postcombustion controls. The post-control 

model results indicate that even after 

application of the State’s selected 

combustion controls to reduce NOX

emissions, a significant visibility impact 

due to NOX emissions from White Bluff 

Units 1 and 2 remains. This 

demonstrates that post-combustion 

controls that result in larger reductions 

of NOX may prove to be cost-effective 

and result in significant visibility 

improvement. We note that the 

modeling of changes in visibility 

impacts is only one of five factors that 

are evaluated in a BART analysis. In 

performing a BART analysis, the State 

must take into consideration all 

technologically feasible and available 

control technologies, the costs of 

compliance, the energy and non-air 

quality environmental impacts of 

compliance, any pollution control 

equipment in use at the source, the 

remaining useful life of the source, and 

the degree of improvement in visibility 

which may reasonably be anticipated to 

result from the use of such 

technology.218 As articulated in more 

detail in our proposal and in our 

response to previous comments, when 

evaluating NOX controls for White Bluff 

Units 1 and 2, the State considered only 

combustion controls that would achieve 

the presumptive NOX emission limit 

even though there are technically 

feasible and available control 

technologies (including postcombustion controls) that are currently 

being used at similar facilities to meet 

an emission limit much more stringent 

than the 0.15 lb/MMBtu presumptive 

limit for NOX. The BART Guidelines 

provide that in identifying control 

options for evaluation in a BART 

analysis, states must identify the most 

stringent option and a reasonable set of 

options for analysis that reflects a 

comprehensive list of available 

technologies.219 In addition, the RHR 

requires that in establishing source 

specific BART emission limits, a state’s 

BART analysis must identify and 

consider the maximum level of emission 

reduction that has been achieved in 

other recent retrofits at existing sources 

in the source category.220 Therefore, as 

explained in more detail in our response 

to previous comments, in its NOX BART 

analysis for White Bluff Units 1 and 2, 

the State must evaluate NOX postcombustion controls at the most 

stringent emission limit capable of being 

achieved by these controls. 

We disagree with the comment’s 

characterization that the CALPUFF 

model approved for regulatory actions is 

not a credible model to assess visibility 

impacts of NOX emissions from 

Arkansas sources. For the specific 

purposes of the RHR’s BART provisions, 

we concluded that CALPUFF (versions 

that EPA has approved) is sufficiently 

reliable to inform the decision making 

process in determining if a full BART 

analysis is required and in estimating 

the degree of visibility improvement 

that may reasonably be expected from 

controlling a single source in order to 

inform the BART determination.221

When we developed the BART 

Guidelines and determined the 

acceptability of using CALPUFF in 

estimating visibility impacts from BART 

sources (BART eligible or subject to 

BART sources), EPA was aware that 

EPA had not approved the regulatory 

version of CALPUFF for doing full 

chemistry as a Guideline on Air Quality 

Models (GAQM) preferred model. The 

final BART Guidelines recommend that 

CALPUFF’s 98th percentile modeling 

results be used to estimate the visibility 

impairment. This is in contrast to the 

approach in our BART Guidelines 

proposal to use the highest daily impact 

value. We acknowledged that the 

chemistry modules in the CALPUFF 

model are simplified and likely to 

provide conservative (higher) results for 

peak impacts. To address the concerns 

which are now being raised by the 

comment, we made the decision to 

consider the less conservative 98th 

percentile to account for this potential 

bias.222

The BART modeling protocol, 

developed by the CENRAP for use by all 

CENRAP states and reviewed by EPA 

and the FLM including the use of 

CALPUFF, was adopted by ADEQ. In 

general, this protocol was followed by 

ADEQ in determining which sources 

were subject-to-BART and in modeling 

visibility impacts from controls in 

evaluating BART.223 In development of 

the CENRAP BART modeling protocol, 

we were concerned that CENRAP had 

not included meteorological observation 

data in development of the 


pmangrum on DSK3VPTVN1PROD with RULES_2
14662 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

224See 76 FR 64205–64207. 

225See 76 FR 52431—52434 and the Response to 

comments document (pg. 124–133) for a full agency 

discussion on why CALPUFF version 6.4 (and other 

non-EPA approved versions) are not acceptable at 

this time for regulatory analyses (EPA Docket ID No. 

EPA–R06–OAR–2010–0846). 

meteorological data sets for the BART 

CALPUFF modeling. We were 

concerned that this approach, that did 

not follow our guidelines, would lead to 

some underestimation of impacts. As a 

result, EPA, FLM representatives, states, 

and stakeholders agreed that they would 

either use the maximum model 

predicted values (instead of the 98th 

percentile) or develop a modeling 

protocol to generate the meteorological 

datasets with meteorological 

observations, which we would then 

allow the use of the 98th percentile. We 

note that the CALPUFF modeling in 

ADEQ’s SIP that was provided by 

Entergy White Bluff’s contractors did 

not use the maximum value but did use 

the CENRAP meteorological dataset and 

used the 98th percentile, which creates 

a concern that visibility impairment will 

be underestimated. We noted this 

concern in our proposal and also a 

concern that Entergy had utilized a 

higher emission rate than is likely 

achievable by the selected control 

technology and both of these issues 

would lead to underestimations in the 

visibility benefit anticipated from the 

use of additional controls.224 These 

issues will need to be addressed when 

a revised BART analysis is completed. 

The comment suggests that CALPUFF 

version 6.4 has been updated with an 

allegedly more robust chemistry and 

purportedly performs better according 

to the comment than the current version 

of the model approved for regulatory 

actions (currently CALPUFF version 

5.8). The comment claims that 

CALPUFF version 6.4 was shared with 

EPA in December 2010. We wish to 

clarify that EPA had a meeting with API 

representatives and others in February 

2011. At this meeting, a PowerPoint was 

shared about CALPUFF version 6.4, but 

the full model code, explanations and 

documentation of the code, model 

evaluations, etc., have not been 

provided to EPA as of February 2012. 

We have a detailed procedure for 

evaluation of new models that includes 

documentation, peer review, evaluation, 

performance analysis, etc. Furthermore, 

significant changes in models (such as 

a significant upgrade in the chemistry 

module) are often required to go through 

a formal rulemaking process for 

adoption. As noted by the comment, we 

previously received comments about the 

CALPUFF version 6.4 model in another 

action and provided a response that a 

proper review analysis and evaluation 

have not been conducted.225 As noted 

by the comment, the more recently 

developed model version (version 6.4) 

has not gone through the appropriate 

review to assess if it is founded in 

appropriate science and performs 

adequately and reliably and is an 

improvement to the current version that 

is acceptable for regulatory actions. If 

the revised versions of CALPUFF can be 

shown to be reliable and acceptable to 

EPA through the appropriate process, it 

would likely be appropriate to the use 

Highest Daily impact (1st High instead 

of the 8th High) based on the 

presumption that the updated chemistry 

of the CALPUFF model would result in 

less conservative results than EPA 

approved CALPUFF versions 5.8 or 

5.711. In past agreements in using the 

CAMx photochemical model, which has 

a robust chemistry module, Region 6 has 

required the use of the 1st High value 

when sources are screened out of a full 

BART analysis based on the CAMx 

results. 

With regard to the comment’s 

observation that the monitoring data 

indicates visibility impacts due to 

nitrate formation occur on colder days 

and that these days are not when winds 

are generally from the south or east, 

EPA notes that monitoring data is only 

collected every three days at each 

IMPROVE monitor and there is only one 

monitor in a Class I area. Modeling 

provides for an analysis of visibility 

conditions during every day of the 

baseline period at a number of receptor 

locations at each Class I area, and is not 

limited by the number of days data is 

collected. Modeling also allows for 

receptors to be placed throughout the 

Class I area and not limited to one 

monitor location for estimating visibility 

impairment throughout the Class I areas. 

Thus, the comment’s observation is 

overly generalized that the winds do not 

generally come from the south and east 

during the colder periods when nitrates 

are a concern at the Class I areas of 

concern. This overly broad-brushed 

statement about wind patterns is not 

supported by a more detailed analysis of 

wind patterns nor transport phenomena 

as wind directions change. We included 

a more sophisticated approach for 

source-receptor analysis in our BART 

Guidelines that takes into account 

meteorological transport patterns on 

every day of the year. Since transport of 

pollutants to the Class I area is not 

always a direct route as wind patterns 

change, the more sophisticated 

approach discussed in the BART 

guidelines is to use a full meteorological 

modeling analysis using prognostic 

meteorological data that has wind speed 

and direction throughout many 

atmospheric layers from the surface to 

the upper atmosphere. CALPUFF 

visibility modeling was performed using 

three years (2001–2003) of prognostic 

meteorological data and 24-hr actual 

maximum emissions, following the 

methods in the BART Guidelines. Precontrol and post-control modeling show 

significant visibility impacts due to the 

Entergy White Bluff’s NOX emissions, 

with some of the highest impacted days 

occurring during the fall and winter 

months. This analysis did not include 

an evaluation based on the most 

effective emission limit that can be 

achieved. So it is likely that there are 

underestimates in the visibility 

improvement that could potentially be 

achieved from installation of BART. The 

use of CALPUFF and prognostic 

meteorological data that is generated 

with the same meteorological models as 

weather forecasting, with the many 

layers of wind speed and direction, is a 

much more appropriate and 

sophisticated approach to analyzing 

visibility impairment than the 

comment’s assessment of potential 

impacts from Arkansas sources 

indicated. Therefore, we disagree with 

the statement that the source would not 

be affecting the Class I areas because the 

winds are not generally from the south 

or east when the coldest conditions 

occur that are associated with the worst 

nitrate haze. 

G. Comments on Legal Issues 

1. Comments on Regional Haze 

Comment: The EPA does not have the 

authority under the CAA to partially 

disapprove portions of Arkansas’s RH 

SIP including BART determinations that 

did not address all the BART factors, 

BART determinations that adopted 

presumptive limits, Arkansas’s LTS, and 

Arkansas’s RPGs. The EPA’s proposal 

improperly encroaches on the state’s 

authority and discretion in developing a 

RH SIP. Arkansas has properly 

exercised its statutory authority under 

the CAA. The EPA must defer to 

Arkansas determinations in their RH SIP 

since EPA lacks the authority to 

substitute its own judgment or policy 

preferences for the state’s 

determination. The EPA’s role in 

implementing the visibility program 

under the RH SIP is one of support and 

cooperation in implementation. 

Response: The EPA’s proposed partial 

disapproval of Arkansas’s RH SIP is a 

proper exercise of EPA’s authority 

under the Clean Air Act. Congress 

crafted the CAA to provide for states to 


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226States must follow the BART Guidelines in 

making BART determinations for EGUs at power 

plants with a total generating capacity greater than 

750 MW. 40 CFR 51.308(e)(1)(ii)(B). In establishing 

presumptive limits for these sources, EPA 

undertook a partial weighing of the statutory factors 

that apply to BART determinations. 

take the lead in developing 

implementation plans, but balanced that 

decision by requiring EPA to review the 

plans to determine whether a SIP meets 

the requirements of the CAA. The EPA’s 

review of SIPs is not limited to support 

and cooperation in implementation of a 

state SIP, nor is it to simply rubberstamp state decisions. When reviewing 

state SIPs, EPA must consider not only 

whether the state considered the 

appropriate factors in making decisions, 

but acted reasonably in doing so. In 

undertaking such a review, EPA does 

not usurp the state’s authority but 

ensures that such authority is 

reasonably exercised. 

In taking action on the Arkansas RH 

SIP submittals, EPA is disapproving a 

portion but approving as much of the 

Arkansas RH SIP as possible. Our action 

today is consistent with the statute. In 

finalizing our proposed determinations, 

we are approving the following: 

Arkansas’s identification of affected 

Class I areas; the establishment of 

baseline and natural visibility 

conditions; the determination of URP; 

Arkansas’s RPG consultation; the RH 

monitoring strategy and other SIP 

requirements under § 51.308(d)(4); 

Arkansas’s commitment to submit 

periodic RH SIP revisions and periodic 

progress reports describing progress 

towards the RPGs; Arkansas’s 

commitment to make a determination of 

the adequacy of the existing SIP at the 

time a progress report is submitted; and 

Arkansas’s consultation with FLMs. We 

are also largely approving those portions 

of the SIP addressing Arkansas’s 

identification of those sources that are 

BART-eligible sources and those subject 

to BART sources; some of the State’s 

BART determinations for five units; 

Arkansas’s RH Rule; and the LTS. 

We are, however, disapproving some 

of the State’s BART determinations for 

nine units. As explained in the proposal 

and the previous response to comments, 

some of the State’s BART 

determinations for the nine units are not 

approvable because Arkansas did not 

follow the requirements of section 40 

CFR 51.308(e). 76 FR at 64186, at 64187. 

As a result of EPA’s disapproval of the 

BART determinations, we are also 

partially disapproving that portion of 

the LTS affected by this disapproval. 

Similarly, EPA’s disapproval of 

Arkansas’s RPGs is based on the state’s 

failure to follow the requirements of 40 

CFR 51.308(d)(i)(A). See also CAA 

§ 169A(g). In concluding that Arkansas 

did not adhere to the requirements of 

the RHR, EPA is not substituting its 

policy judgment for that of Arkansas but 

rather exercising its authority to ensure 

that the state’s decisions are reasonable 

ones that meet statutory and regulatory 

requirements. 

Comment: The CAA gives primacy to 

the states in devising the LTS for 

making reasonable progress toward the 

national visibility goal and in making 

BART determinations and limited 

authority to EPA. In accordance with 

section 169A(a)(4), EPA promulgates 

regulations to assure progress towards 

the national goal of preventing future 

and remedying existing visibility 

impairment in Federal class I areas 

while the states are required to submit 

SIP which meets these measures. In 

1999 and 2005, EPA promulgated and 

subsequently amended the RHR which 

gives guidance to the states on how to 

develop a visibility program that meets 

the national visibility goal for their 

state. Section 169(A)(b)(2) requires 

States to direct sources subject to BART 

to comply with a BART determination. 

In accordance with section 169B, states, 

acting together through visibility 

transport commissions, are primarily 

responsible for formulating a 

coordinated response to interstate 

transport of visibility. With respect to 

the RHR and the BART Guidelines, the 

CAA only requires that states take 

measures necessary to make reasonable 

progress toward the national goal by 

engaging in the process of weighing 

statutory factors. Regarding EPA’s role, 

section 169A(g)(2) (as defined in Train 

v. Natural Res. Def. Council, 421 U.S. 

60, 79 (1975)) provides that EPA may 

disapprove a SIP only where a state’s 

SIP fails to meet the minimum CAA 

requirements. 

Response: We agree that the states are 

assigned statutory and regulatory 

authority to draft and implement the 

visibility program as well as to make 

BART determinations for sources within 

their state. Although the states generally 

have the freedom to determine the 

weight and significance of the statutory 

factors in making BART 

determinations 226, they have an 

overriding obligation to come to a 

conclusion that is based on reasoned 

analysis. Similarly, states are given 

flexibility in determining reasonable 

progress, but in making that 

determination, they are required by the 

CAA to consider certain factors. 

Whether one characterizes EPA’s role as 

limited or not limited in reviewing RH 

SIPs, EPA must determine if the state’s 

SIP meets the applicable statutory and 

regulatory requirements. The state’s 

BART determinations for some sources, 

its LTS, and RPGs were flawed for 

reasons discussed elsewhere in this 

notice and the proposed rulemaking. 

While states have the authority to 

exercise different choices in 

determining BART or setting RPGs, such 

decisions must be reasonable and 

consistent with statutory and regulatory 

requirements. Arkansas’s errors were 

significant enough that we cannot 

conclude that the state’s decision met 

this standard. Our disapproval of 

portions of the RH SIP has an 

appropriate basis in our CAA authority. 

Comment: U.S. courts agree that 

EPA’s role in reviewing visibility 

programs and determining BART is 

limited. According to American Corn 

Growers Ass’n v. EPA, 291 F.3d 1 (DC 

Circuit 2002), states play the lead role 

in designing and implementing RH 

programs. American Corn Growers 

outlined the legislative history, 

including the Conference Report on the 

1977 amendments, when the Court 

invalidated past regulatory provisions 

regarding BART for constraining state 

authority. The Court stated that the 

Conference report confirmed that 

Congress intended states to decide 

which sources impair visibility and 

what BART controls apply to those 

sources. 

Response: We agree that the CAA 

places the requirements for developing 

RH plans and determining BART for 

BART-eligible sources on states. As 

discussed above, EPA’s role is to review 

the RH SIP submittal including the 

BART determinations and determine if 

the state met the applicable statutory 

and regulatory requirements. While the 

court in American Corn Growers found 

that EPA had impermissibly constrained 

state authority, it did so because it 

found that EPA forced states to require 

BART controls without first assessing a 

source’s particular contribution to 

visibility impairment. This is not the 

case with our action. We are not forcing 

Arkansas to adopt a particular measure 

or to weigh the statutory factors in a 

particular way. Rather, we are 

disapproving portions of Arkansas’s RH 

SIP that address BART, LTS, and RPGs 

because the state omitted critical 

analyses and made flawed assumptions 

that compromise any decisions. 

Comment: The Supreme Court has 

ruled that states have primary authority 

in issues relating to the CAA. In Train 

v. Natural Res. Def. Council, 421 U.S. 60 

(1975), the court ruled that EPA had no 

authority to question the wisdom of a 

state’s choices of emissions limitations 

if they are part of a plan which satisfies 

the standards of the CAA. The EPA may 


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devise and promulgate a specific plan of 

its own only if a state fails to submit an 

implementation plan which satisfies 

those standards. 

Response: Our action does not 

contradict the Supreme Court’s decision 

in Train. States have significant 

responsibilities in implementation of 

the CAA and meeting the requirements 

of the RHR. We recognize that states 

have the primary responsibility of 

drafting an implementation plan to 

address the requirements of the CAA 

Visibility Program. We also recognize 

that we have the responsibility of 

ensuring that the state plans, including 

RH SIPs, conform to the CAA 

requirements. We cannot approve a RH 

SIP that fails to address BART, LTS, and 

RPGs with a reasoned consideration of 

the statutory and regulatory 

requirements of the CAA and the RHR. 

Comment: Because visibility 

impairment is primarily aesthetic and 

does not rise to the same level of public 

policy concern as dangers to the public 

health, Congress made the national 

visibility goal discretionary. 

Accordingly, unlike other provisions of 

the CAA, the national visibility goal is 

not considered to be a non-discretionary 

duty of the Administrator under section 

169A(f). Likewise, the court in 

American Corn Growers has recognized 

that the natural visibility goal is not a 

mandate but a goal. In addition, the 

CAA does not mandate a particular 

timeframe to meet the national goal of 

natural visibility, only that states make 

reasonable progress. The amount of 

progress that is reasonable is not 

defined according to objective criteria 

but instead involves balancing of public 

interest. 

Response: We do not agree that the 

CAA or RHR prescribes a different 

degree of authority to states based on 

the program having the goal of 

improving visibility as opposed to 

preventing adverse human health 

effects. Among other things, the CAA 

requires states to submit plans that 

satisfy NAAQS standards set to protect 

both public health and welfare. Nothing 

in the terms of the CAA or its 

implementation history directs that SIP 

submittals addressing visibility are 

subject to a different standard of 

evaluation than SIP submittals that 

directly address public health issues 

associated with air pollutants. The 

distinction is not relevant to state 

authority to develop RH SIPs and does 

not diminish our responsibility and 

authority to require that they conform to 

the RHR and the Act. 

More generally, we agree that the 

CAA does not mandate a particular 

timeframe to meet the national visibility 

goal. The comment is not relevant, 

however, as our action to partially 

disapprove Arkansas’s RH SIP is not 

based on a finding by EPA that 

Arkansas’s RH SIP fails to achieve the 

national goal. Similarly, EPA is not 

disapproving Arkansas’s RH SIP 

because we disagree per se with the 

State’s conclusions as to what 

constitutes reasonable progress for this 

time period. Our disapproval of the 

Arkansas RH SIP is based on the fact 

that critical analyses were omitted and 

that these omissions compromise 

Arkansas’s determinations as to the 

measures necessary to make reasonable 

progress. 

Comment: Although EPA can set 

national goals and guidelines for the RH 

program, individual states have the 

authority to select BART for specific 

sources of emissions and design the 

specific plans that are appropriate for 

respective populations. The RHR does 

not require a definitive dv or percent 

improvement in visibility. The only 

thing the RHR requires of each state is 

to demonstrate an improvement in 

visibility. The Arkansas RH SIP meets 

EPA’s national goals and guidelines. 

The Arkansas RH SIP establishes a firm 

foundation to meet the required RPGs 

and meets and in some cases even 

exceeds the requirements of the RHR. 

Response: We do not agree that the 

only thing that the RHR requires is for 

each state to demonstrate an 

improvement in visibility. The RHR 

outlines a process by which states are to 

evaluate and develop RH SIPs, 

including the process for making BART 

determinations. The EPA is 

disapproving portions of Arkansas’s RH 

SIP that address BART, LTS, and RPGs 

because the state omitted critical 

analyses in accordance with the 

requirements of the CAA and the RHR. 

Comment: The preamble to the RHR 

recognized that States are the primary 

decision makers in determining how to 

make BART determinations and 

determining which sources are subject 

to BART. In analyzing the applicability 

of certain executive orders to the 

proposed RHR, EPA states that states 

will ultimately determine the sources 

subject to BART and the appropriate 

level of control for such sources, and 

that states accordingly exercise 

substantial intervening discretion in 

implementing the final rule (70 FR 

39155). 

Response: We agree that states are 

assigned statutory authority to 

determine BART and that EPA has made 

statements confirming the state’s 

authority in this regard. States have the 

flexibility to determine the weight and 

significance of the statutory factors. 

However, states must make a reasoned 

determination consistent with the 

requirements of the RHR. As detailed in 

our proposal and the supporting TSD, 

Arkansas’s BART determination for nine 

units, Arkansas’s LTS, and RPGs did not 

provide reasoned determinations 

conforming to the requirements of the 

RHR. 

Comment: The EPA partially 

disapproved Arkansas’s RH SIP because 

the EPA disagreed with the State’s 

conclusions. The EPA failed to defer to 

the State’s lawful exercise of its 

discretion pursuant to the CAA’s 

provisions for visibility protection. 

Response: Our partial disapproval of 

Arkansas’s RH SIP is not based on the 

resulting Arkansas conclusions. Rather 

our decision to disapprove Arkansas’s 

BART determinations for nine units, 

LTS, and RPGs is because the state 

omitted critical analyses and made 

flawed assumptions that compromise 

the resulting determinations. The State 

could submit and EPA would approve 

RH SIP revisions that reached identical 

determinations as the current SIP 

submittal if Arkansas’s analysis in 

reaching those determinations meets the 

RHR and the Act. 

Comment: The EPA has overstepped 

its authority in proposing to reject the 

state’s BART determinations on the 

basis of EPA’s view that the state’s 

consideration of certain statutory factors 

was not ‘‘adequate.’’ The state, as the 

determining authority, has the power to 

decide how each of the BART factors 

should be taken into account and 

weighed. As long as a state considers a 

given factor, it has met its obligations in 

regards to that factor. Once the state has 

made its decision, EPA has no authority 

to ‘‘second-guess’’ the conclusions that 

the state has reached. 

Response: As explained earlier, the 

states have the responsibility to draft the 

RH SIP and the EPA has the 

responsibility of ensuring State plans, 

including RH SIPs, conform to the CAA. 

As the drafter of the RH SIP, the state 

generally has the authority to decide 

how each of the BART factors are taken 

into account and weighed. EPA is not 

disapproving Arkansas’s BART 

determinations because it disagrees with 

how Arkansas weighed the relevant 

factors, such as the cost of controls or 

the degree of visibility improvement 

resulting from the use of controls. The 

EPA is disapproving certain Arkansas’s 

BART determinations because they did 

not consider these factors in their BART 

determinations in accordance with the 

RHR and the Act. 

Comment: All of the BART 

determinations made by Arkansas RH 

SIP should be disapproved because 


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227CAA section 110(c)(1). 

Arkansas did not do its own BART 

analysis in making its BART 

determinations. Instead, Arkansas RH 

SIP adopted the companies’ BART 

analysis as part of the RH SIP and 

promulgated them into State regulation. 

Given that Arkansas has not made any 

of its own BART determinations, there 

are no BART determinations for EPA to 

act on. 

Response: Arkansas submitted a RH 

SIP which provided BART 

determinations for sources that are 

subject to BART. Arkansas requested 

that sources subject to BART submit 

material including a BART analysis. 

Arkansas then reviewed the analysis 

and data provided by the sources and 

adopted its BART determinations. The 

EPA reviews RH SIP submittals from 

states that rely upon source-generated 

data and information to evaluate 

whether the State’s decisions meet the 

Act and EPA rules. In Arkansas’s case, 

after their review of the sources’ 

provided information, they reached the 

same BART determinations as was 

provided by the source. 

Comment: Arkansas improperly 

planned to make its BART 

determinations during the permitting 

process, not in the SIP submittal. In 

2009, ADEQ proposed a Title V permit 

amendment for Entergy’s White Bluff 

power plant to, among other things, 

incorporate BART emission limits and 

requirements, in which ADEQ proposed 

different pollution controls as BART 

than what was in the company’s BART 

analysis in Appendix 9.3 of the 

Arkansas RH SIP submitted to EPA. 

Response: We disagree that Arkansas 

planned to make its BART 

determinations during the permitting 

process, be it through the New Source 

Review preconstruction permitting SIP 

process or the Title V operating permit 

program. The State adopted its BART 

determinations through rulemaking and 

they are found in Chapter 15 of APCEC 

Regulation No. 19, as contained in the 

RH SIP submissions. Each of the BART 

determinations approved by EPA today 

becomes effective under Federal law. It 

also becomes an applicable requirement 

that must be included in a Title V 

permit. Any source subject to the BART 

determinations approved today must at 

a minimum meet these requirements, as 

expressed in 40 CFR 51.308(e). If 

Arkansas issues a Title V permit that 

has less stringent requirements than the 

EPA-approved BART determination, 

then the source is subject to Federal 

enforcement action. It is incumbent 

upon the source to ensure that its Title 

V permit application meets all the 

applicable Federal requirements. It also 

is incumbent upon the source to ensure 

that it meets the most stringent 

applicable Federal requirement. If the 

State wishes to impose BART emission 

limitations in a Title V permit that are 

different from what EPA is approving 

today as BART, then Arkansas must 

adopt and submit a revised RH SIP and 

submit it to EPA for approval as a SIP 

revision. 

Comment: The EPA should not act on 

any of the company’s BART analyses, 

unless it conducts its own analysis of a 

company’s submittal in the context of a 

FIP. 

Response: Under the CAA, we must, 

within 24 months following a final 

disapproval, either approve a SIP or 

promulgate a FIP.227 As stated 

elsewhere in this final rulemaking, we 

will consider, and would prefer, 

approving a SIP if the State submits a 

revised plan that we can approve before 

the expiration of the mandatory FIP 

clock for the portions of the SIP we are 

disapproving in this rulemaking action. 

In light of this, we are choosing at this 

time not to perform any BART analyses 

and not to develop and propose a FIP 

for the BART determinations we are 

disapproving. 

Comment: The EPA has no reason to 

disapprove a State BART determination 

that meets the presumptive BART level. 

The DC Circuit Court of Appeals held in 

American Corn Growers Association v. 

EPA, that there is nothing in the CAA 

that would require a State to adopt 

provisions more stringent than the 

Federal requirement. 

Response: In disapproving BART 

determinations for certain subject-toBART sources that adopted the 

presumptive limits, EPA is not requiring 

Arkansas to establish BART limits that 

are more stringent than Federal 

requirements. Under the RHR, 

presumptive limits were established to 

provide a path for States to follow when 

analyzing BART for particular EGUs. 

The RHR has presumptive limits that act 

as a starting point for the establishment 

of BART emission limits unless the 

state’s analysis indicates that an 

emission limit more or less stringent 

than the presumptive limit is required. 

The EPA’s BART Rule and the BART 

Guidelines make clear that in 

developing the presumptive emission 

limits, EPA made many design and 

technological assumptions, and that the 

presumptive limits may not be BART in 

every case. As such, the presumption in 

the BART Rule is that the controls 

reflected by the presumptive limits are 

cost-effective, not that the presumptive 

limits will be BART in every case. 

Thus, EPA’s proposed rulemaking on 

the Arkansas RH SIP did not propose to 

require Arkansas’s subject to BART 

sources to achieve an emission rate 

more stringent than the presumptive 

emission limits. Rather, EPA’s proposed 

rulemaking proposed to disapprove the 

BART emission limits for subject to 

BART sources where the State adopted 

presumptive emission limits without 

conducting a proper BART five-factor 

analysis. Only after the State conducts 

a proper evaluation of the five statutory 

factors, as required by 40 CFR 

51.308(e)(1)(ii)(A) and section 169A(g) 

of the CAA, or EPA conducts one in the 

context of a FIP, will it be demonstrated 

whether any of Arkansas’s subject to 

BART sources must achieve an emission 

rate more (or less) stringent than the 

presumptive limits. 

Comment: Because the State of 

Arkansas adopted EPA’s presumptive 

emission limits by default, the State of 

Arkansas did not fulfill its statutory 

duty under 169A of the CAA and under 

Arkansas law to determine BART. In 

addition, the State of Arkansas failed to 

determine, using the five factors 

required under section 169A of the CAA 

whether the actual costs of the proposed 

control technology justified the State’s 

determination of BART for those 

facilities. 

Response: As explained above, 

presumptive limits are the starting point 

in a BART determination unless the 

state determines that the general 

assumptions underlying EPA’s analysis 

in the RHR are not applicable to a 

particular case. Section 169A outlines 

the analysis that is required in order to 

make a BART determination. We are 

finding that the State’s BART 

determinations for certain subject-toBART sources do not comply with the 

CAA requirements by adopting the 

presumptive emissions limit without 

conducting a proper BART five factor 

analysis. Only after the State conducts 

a proper evaluation of the five statutory 

factors, as required by 40 CFR 

51.308(e)(1)(ii)(A) and section 169A(g) 

of the CAA, or EPA conducts one in the 

context of a FIP, will it be demonstrated 

whether any of Arkansas’s subject to 

BART sources must achieve an emission 

rate more (or less) stringent than the 

presumptive limits. 

Comment: The portion of the 

Arkansas RH SIP that EPA has proposed 

to approve is not separable from the 

overall Arkansas RH SIP. The EPA 

should fully disapprove the Arkansas 

RH SIP because it fails to meet the 

requirements for RH SIPs. 

Response: The Arkansas BART 

determinations for some of the units, 

LTS, and RPGs are separable portions of 


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the RH SIP submittal. The EPA can 

approve some of the SIP submittal and 

disapprove the remainder as long as the 

portions that are disapproved do not 

affect those that are approved. This is 

the case in our action partially 

disapproving Arkansas’s RH SIP for its 

BART determinations for some of the 

units, LTS, and RPGs and approving the 

remainder of the RH SIP. 

2. Comments on Interstate Transport 

and Visibility 

Comment: Arkansas’s April 2008 

Interstate Transport SIP was in 

accordance with the 2006 Guidance, 

and virtually identical to those 

submitted by Arizona, Iowa, Kansas, 

Minnesota, Nebraska, Nevada, South 

Dakota, Utah, and Wyoming. The EPA 

approved those states’ Interstate 

Transport SIPs in a timely fashion 

because they were consistent with 

EPA’s 2006 Guidance, yet ignored 

Arkansas’s Interstate Transport SIP until 

after EPA’s statutory deadline to act; 

when it evaluated the SIP, it was not by 

the criteria established in the 2006 

Guidance. In an August 2011 

rulemaking to promulgate a Federal 

implementation plan (FIP) for visibility 

improvement in New Mexico, EPA for 

the first time claimed its 2006 Guidance 

interpreting the Good Neighbor 

Provision of the CAA- on which 

Arkansas had based its 2008 Interstate 

Transport SIP- had been published ‘‘in 

error’’ (76 FR 52418). In the same 

rulemaking, EPA put forth a new 

framework for interpreting the 

requirements pursuant to the visibility 

component of the Good Neighbor 

Provision. Inconsistent with the 2006 

Guidance, EPA now holds that it is 

possible to determine whether a state is 

violating the Good Neighbor Provision, 

based on what the state ‘‘should’’ have 

in its Regional Haze SIP. EPA’s new 

criteria for evaluating Interstate 

Transport SIP submissions is based on 

the air quality modeling performed by 

regional planning organizations, and on 

whether there are differences between 

emissions reductions in a state’s RH SIP 

and emissions reductions assumptions 

derived from the air modeling 

performed by regional planning 

organizations. Although EPA has not 

issued a new guidance document to 

reflect what states ‘‘should’’ have in 

their SIPs ‘‘at this point in time,’’ EPA 

has approved the visibility component 

of several Interstate Transport SIPs 

using criteria other than the 2006 

Guidance. The EPA has not explained 

this regulatory inconsistency between 

its treatment of Arkansas’s Interstate 

Transport SIP versus Arizona, Iowa, 

Kansas, Minnesota, Nebraska, Nevada, 

South Dakota, Utah, and Wyoming’s 

Interstate Transport SIPs. The EPA 

cannot hold different states to different 

requirements pursuant to the visibility 

component of the CAA’s Good Neighbor 

Provision. 

Response: Section 110(a)(2)(D)(i)(II) 

does not explicitly define what is 

required in SIPs to prevent the 

prohibited impact on visibility in other 

states nor does it explicitly define how 

to determine if an action by a state is 

interfering with another state’s specific 

visibility measure. A RH SIP that 

provides for emissions reductions 

consistent with the assumptions used in 

the modeling of other CENRAP states is 

an appropriate way to meet a state’s 

obligations to the other regional 

planning states with regards to noninterference with another state’s 

visibility measures is consistent with 

the CAA. 

On March 28, 2008, Arkansas 

submitted revisions to its section 

110(a)(2)(D)(i) Interstate Transport SIP. 

In its March 28, 2008 SIP submission, 

Arkansas stated it is meeting the 

requirements for protection of visibility 

in section 110(a)(2)(D)(i)(II) by the 

adoption in 2007 of Chapter 15 of 

APCEC Regulation No. 19, which 

established Arkansas’s RH program 

requirements. Arkansas also stated in 

the March 28, 2008, SIP submission, 

that it was not possible at that time to 

assess whether there is interference with 

measures in the applicable SIP for 

another state until the Arkansas RH SIP 

is submitted and approved by EPA. 

Arkansas also submitted Chapter 15, 

Regulation 19 in its September 9, 2008 

RH SIP submittal. The Arkansas RH 

regulation established a compliance 

timeframe of October 15, 2013, six years 

after the adoption of the state regulation 

or within five years of the date of the 

approval of the RH SIP by EPA, 

whichever date comes first. Chapter 15, 

Regulation 19 outlined the BART 

determinations for sources within 

Arkansas including some sources that 

do not require a mandatory BART 

determination under the RHR. The 

emission reductions resulting from the 

State BART determinations codified in 

Chapter 15, Regulation 19 are identical 

to the emissions reductions promised by 

Arkansas to the other CENRAP member 

states and included in the CENRAP 

2018 emissions inventory modeling to 

represent Arkansas’s share of emission 

reductions for the region. The CENRAP 

member states are basing their RPGs and 

RH programs from this anticipated 

CENRAP 2018 emissions inventory 

modeling. On September 23, 2008, 

Arkansas submitted its RH SIP 

including Chapter 15, Regulation 19 to 

EPA for approval. 

The EPA could have approved 

Arkansas’s 110(a)(2)(D)(i) Interstate 

Transport SIP in 2008 when Arkansas 

originally submitted the SIP. Chapter 

15, Regulation 19 originally established 

a compliance timeframe of October 15, 

2013, six years after the adoption of the 

state regulation or within five years of 

the date of the approval of the RH SIP 

by EPA, whichever date comes first. 

This provided the necessary emission 

limits and enforceable mechanisms to 

ensure Arkansas’s apportionment of 

emissions reductions used in the 

CENRAP modeling. However, on March 

17, 2010, Arkansas granted a variance 

from the October 15, 2013 deadline 

imposed by Regulation 19.1504(B) for 

sources subject to BART listed at 

Regulation 19.1504(A). Instead, sources 

subject-to-BART are required to comply 

with BART only within five years after 

EPA approves Arkansas’s RH SIP. This 

variance was never submitted to EPA as 

a SIP revision. As explained in an 

earlier response to comments, we are 

disapproving the portion of the BART 

compliance provision found in the 2008 

submitted Chapter 15 of Regulation No. 

19 that requires compliance with BART 

requirements no later than six years 

after the effective date of the State’s 

regulation since Arkansas no longer has 

the legal authority to enforce this 

provision. We are partially approving 

and partially disapproving the portion 

of the BART compliance provision that 

requires each Arkansas subject-to-BART 

source to install and operate BART as 

expeditiously as practicable, but in no 

event later than five years after EPA 

approval of the Arkansas RH SIP 

consistent with the requirements under 

40 CFR § 51.308(e)(iv). Because of our 

disapproval of the six year compliance 

timeframe in Arkansas’s 2008 submitted 

Chapter 15 of Regulation 19, as well as 

disapproval of certain BART 

determinations, all of Arkansas’s 

promised enforceable emission 

reductions factored into CENRAP’s 2018 

emissions inventory modeling and 

relied upon by fellow CENRAP member 

states in developing their RPGs and RH 

SIPs will not be met. Thus, the 

requirements for section 

110(a)(2)(D)(i)(II) will not be met. 

If we had acted upon the Arkansas RH 

SIP earlier than 2010, it would not 

change EPA’s determination that 

Arkansas’s emissions are interfering 

with other states’ visibility programs 

because Arkansas’s subsequent adoption 

of the BART variance removing the 

guaranteed six year compliance 

requirement would have rendered the 

hypothetically-approved section 


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110(a)(2)(D)(i)(II) SIP provisions 

unenforceable. To address this, we 

would be required to issue a SIP Call 

now and Arkansas would be required to 

revise its SIP to correct the inadequacies 

by a given due date or face sanctions for 

failure to timely submit a complete SIP 

revision. The BART determinations we 

would have disapproved in our earlier 

hypothetical action would no longer be 

required to occur by October 2013 under 

the State’s law regardless of EPA’s 

disapproval action, and therefore 

Arkansas emissions would continue to 

interfere with other states’ visibility 

programs. The emissions reductions 

resulting from those BART 

determinations would not be required to 

happen at all since the variance 

conditions BART compliance upon EPA 

approval of the Arkansas RH SIP. 

The EPA’s partial disapproval of 

Arkansas’s SIP addressing section 

110(a)(2)(D)(i)(II) is consistent with 

EPA’s actions on the SIPs of Arizona, 

Iowa, Kansas, Minnesota, Nebraska, 

Nevada, South Dakota, Utah, and 

Wyoming. Section 110(a)(2)(D)(i)(II) 

does not explicitly define what is 

required in SIPs to prevent the 

prohibited impact on visibility in other 

states. However, because the RH 

program requires measures that must be 

included in SIPs specifically to protect 

visibility, EPA’s 2006 Guidance 

recommended that RH SIP submissions 

meeting the requirements of CAA 

section 110(a)(2)(D)(i)(II) with respect to 

visibility would be sufficient. We 

approved the SIPs of Arizona, Iowa, 

Kansas, Minnesota, Nebraska, Nevada, 

South Dakota, Utah and Wyoming in 

accordance with the 2006 Guidance in 

2007 and 2008. However, our 2006 

Guidance reflected our 

recommendations for how states could 

potentially meet the section 

110(a)(2)(D)(i)(II) requirement at that 

point in time. As of August 2006, we 

stated our belief that it was ‘‘currently’’ 

premature for states to make a more 

substantive SIP submission for this 

element, because of the anticipated 

imminent RH SIP submissions. We 

explicitly stated that ‘‘at this point in 

time’’ in August of 2006, it was not 

possible to assess whether emissions 

from sources in the state would interfere 

with measures in the SIPs of other 

states. As subsequent events have 

demonstrated, we were mistaken as to 

the assumption that all states would 

submit RH SIPs in December of 2007 

and mistaken as to the assumption that 

all such submissions would meet 

applicable RH program requirements 

and therefore be approved shortly 

thereafter. Thus, the premise of the 2006 

Guidance that it would be appropriate 

to await submission and approval of 

such RH SIPs before evaluating SIPs for 

compliance with section 

110(a)(2)(D)(i)(II) was in error. Our 2006 

Guidance was clearly intended to make 

recommendations that were relevant at 

that point in time, and subsequent 

events have rendered it inappropriate in 

this specific action. 

Because of the need to act 

immediately on section 110(a)(2)(D)(i), 

when some states did not make the RH 

SIP submission in whole or in part, or 

did not make an approvable RH SIP 

submission, we have evaluated whether 

states could comply with section 

110(a)(2)(D)(i)(II) by other means. Thus, 

we have elsewhere determined that 

states may also be able to satisfy the 

requirements of CAA section 

110(a)(2)(D)(i)(II) with something less 

than an approved RH SIP, see e.g. 

Colorado (76 FR 22036 (April 20, 2011)), 

Idaho (76 FR 36329 (June 22, 2011)), 

and New Mexico (76 FR 52388 (August, 

22, 2011)). In other words, an approved 

RH SIP is not the only possible means 

to satisfy the requirements of CAA 

section 110(a)(2)(D)(i)(II) with respect to 

visibility; however such a SIP could be 

sufficient. 

As stated earlier, Arkansas submitted 

revisions to its section 110(a)(2)(D)(i) 

Interstate Transport SIP that addressed 

the requirements for protection of 

Visibility in section 110(a)(2)(D)(i)(II) by 

enacting the Arkansas Pollution Control 

and Ecology Commission regulation 

Chapter 15, Regulation 19 that 

established Arkansas’s RH program 

requirements and stating that it was not 

possible at this time to assess whether 

there is interference with measures in 

the applicable SIP for another state until 

Arkansas’s RH SIP is submitted and 

approved by EPA. Since EPA was no 

longer waiting for the approval of a RH 

SIP to determine interference with 

another state’s visibility program, we 

looked at BART determinations cited in 

Chapter 15, Regulation 19 and 

submitted in their Interstate Transport 

SIP. The emission reductions resulting 

from the BART determinations in 

Chapter 15, Regulation 19 are identical 

to the emissions reductions promised by 

Arkansas to the other CENRAP member 

states and included in the 2018 

CENRAP modeling to represent 

Arkansas’s share of emission reductions 

for the region. The CENRAP member 

states are basing their RPGs and RH 

programs on this CENRAP modeling. 

As in New Mexico, we have 

determined that the analysis conducted 

by a RPO such as CENRAP provides an 

appropriate means to ensure that 

emissions from sources within the state 

are not interfering with the visibility 

programs of other states, as 

contemplated in section 

110(a)(2)(D)(i)(II). In developing their 

visibility projections using 

photochemical grid modeling, CENRAP 

states assumed a certain level of 

emissions from sources within 

Arkansas. Although we have not yet 

received all RH SIPs, we understand 

that the CENRAP states used the 

visibility projection modeling to 

establish their own respective RPGs. 

Thus, we believe that an 

implementation plan that provides for 

emissions reductions consistent with 

the assumptions used in the CENRAP 

modeling will ensure that emissions 

from Arkansas sources do not interfere 

with the measures designed to protect 

visibility in other states. 

For Arkansas, the EPA is 

disapproving certain BART 

determinations. This means that some 

sources within Arkansas do not have an 

enforceable emission reduction 

requirement to meet the emissions 

reductions promised by Arkansas to 

CENRAP member states and modeled by 

CENRAP in their anticipated 2018 

emissions inventory because, as 

explained earlier, Arkansas’s enactment 

of a variance that conditions the BART 

determinations in Chapter 15, 

Regulation 19 upon EPA’s approval of 

Arkansas RH SIP. Since Arkansas no 

longer has an enforceable requirement 

for certain Arkansas BART 

determinations that EPA is 

disapproving, their promised emissions 

reductions included in CENRAP’s 

modeling and the resulting 2018 

emissions inventory will not be realized 

even though other CENRAP member 

states are relying upon them in the 

promulgation of their RPGs and RH 

SIPs. Thus, our disapproval of some of 

Arkansas’s BART determination means 

that we have to disapprove a portion of 

the section 110(a)(2)(D)(i)(II) SIP 

submittal. 

Comment: The EPA cannot at this 

time make a determination of whether 

Arkansas RH SIP interferes with 

measures in another state’s RH SIP for 

purposes of protecting visibility since 

EPA has not yet approved any other RH 

SIP for a state with a class area that may 

be affected by Arkansas sources. 

Response: We disagree that we cannot 

make a determination of whether the 

Arkansas RH SIP interferes with 

measures in another state’s RH SIP for 

purposes of protecting visibility without 

approving other states’ RH SIPs that 

have a class I area that may be affected 

by Arkansas sources. The comment is 

inconsistent with the objectives of the 

statute to protect visibility programs in 


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other states if a state never submits an 

approvable RH SIP. Second, this 

approach is inconsistent with the time 

requirements of section 110(a)(1) which 

specifies that SIP submissions to 

address section 110(a)(2)(D)(i), 

including the visibility prong of that 

section, must be made within three 

years after the promulgation of a new or 

revised NAAQS. While there have been 

delays with both RH SIP submissions by 

states and our actions on those RH SIP 

submissions, those delays do not 

support a reading of the statute that 

overrides the timing requirements of the 

statute. At this point in time, states are 

required to have submitted RH plans to 

EPA that establish RPGs for class I areas. 

This requirement applies whether or not 

states have, in fact, submitted such 

plans. We believe that there are means 

available now to evaluate whether a 

state’s section 110(a)(2)(D)(i)(II) SIP 

submission meets the substantive 

requirement that it contain provisions to 

prohibit interference with the visibility 

programs of other states, and therefore 

that further delay, until all RH SIPs are 

submitted and fully approved, is 

unwarranted and inconsistent with the 

key objective to protect visibility. 

Comment: There is nothing in the 

record to demonstrate that Arkansas RH 

SIP interferes with any measure 

included in any other state’s SIP for the 

purpose of protecting visibility. 

Missouri is the only state with Federal 

Class I areas where visibility is 

impacted by the interstate transport of 

haze-causing emissions originating in 

Arkansas, and per a consent decree, 

EPA is not required to act on Missouri’s 

Regional Haze SIP submission until 

June 15, 2012 (76 FR 75544). 

Response: As explained in an earlier 

response, the EPA does not have to wait 

to make a determination of interference 

with another state’s visibility program 

until EPA approves Arkansas’s RH SIP 

or the surrounding states’ RH SIPs that 

have a class I area affected by Arkansas 

emissions because EPA has a duty to act 

and an ability to make a section 

110(a)(2)(D)(i)(II) determination through 

means other than an approvable RH SIP. 

Arkansas is a member state of CENRAP, 

the regional planning committee on 

regional haze. Each state based its RH 

Plans and RPGs based on CENRAP 

modeling. The CENRAP modeling was 

based in part on the emissions 

reductions each state intended to 

achieve by 2018. In the case of 

Arkansas, some of the emissions 

reductions included in the modeling, 

and thus relied upon by other states, 

were from BART controls on Arkansas 

subject to BART sources. Since, as 

discussed in a previous response, 

compliance of Arkansas’s subject to 

BART sources with BART requirements 

is dependent upon our approval of the 

RH SIP, and since we are proposing to 

disapprove the portion of the RH SIP 

which includes some of Arkansas’s 

BART determinations, a portion of the 

emission reductions committed to by 

Arkansas and relied upon by other 

states including Missouri will not be 

realized. As a consequence, Arkansas’s 

emissions will interfere with other 

states’ SIPs to protect visibility. 

Therefore, we are partially approving 

and partially disapproving the portion 

of the Arkansas Interstate Transport SIP 

submittal that addresses the visibility 

requirement of section 110(a)(2)(D)(i)(ii) 

that emissions from Arkansas sources 

not interfere with measures required in 

the SIP of any other state under part C 

of the CAA to protect visibility. 

Comment: To the extent that EPA’s 

disapproval of the Arkansas RH SIP is 

premised on the language in section 

110(a)(2)(D)(i)(II), but is not based on 

direct interference with a specific 

measure in another state’s RH SIP, as 

opposed to interference with a RH 

related goal in or underlying another 

state’s SIP as required by statute, EPA’s 

interpretation is contrary to the clear 

and express language of section 110 of 

the CAA. 

Response: Section 110(a)(2)(D)(i)(II) 

does not explicitly define what is 

required in SIPs to prevent the 

prohibited impact on visibility in other 

states nor does it explicitly define how 

to determine if an action by a state is 

interfering with another state’s specific 

visibility measure. A RH SIP that 

provides for emissions reductions 

consistent with the assumptions used in 

the modeling of other CENRAP states is 

appropriate to meet a state’s obligations 

to the other regional planning states 

with regards to non-interference with 

another state’s visibility measures and is 

consistent with the CAA. The ‘‘2006 

Guidance for SIP Submissions to Meet 

Current Outstanding Obligations Under 

Section 110(a)(2)(D)(i) for the 8-Hour 

Ozone and PM2.5 NAAQS’’ defined that 

a RH SIP submittal can determine 

whether or not a state SIP for 8 hour 

ozone or PM2.5 contain adequate 

provisions to prohibit emissions that 

interfere with measure in other states. 

As explained earlier, Arkansas chose to 

meet their section 110(a)(2)(D)(i)(II) 

requirements through their BART 

determinations. These emissions 

reductions were promised to other 

CENRAP states and included in the 

CENRAP modeling used by other states 

to develop their RPGs. As discussed 

previously, by Arkansas having some of 

its BART determinations disapproved 

today by EPA, Arkansas will no longer 

meet its committed-to emission 

reductions that the other states are 

relying on in order to meet their RH 

SIPs and RPGs. 

Comment: The EPA’s interpretation of 

section 110(a)(2)(D)(i)(II) is contrary to 

the CAA’s clear direction that each state 

is to determine its own emission limits, 

schedules of compliance, and other 

measures for sources in that state for 

purposes of visibility protection under 

169A. The EPA’s interpretation would 

effectively give one state the power to 

control another state’s RH SIP decisions 

including its BART determinations. 

Response: As explained earlier, 

Arkansas elected to have its promised 

emission reductions used in the 

CENRAP modeling and relied upon by 

other CENRAP member states. These 

emission reductions Arkansas 

committed to are reflected in the 

Arkansas RH SIP submittal from BART 

controls on Arkansas subject to BART 

sources. An approved RH SIP that 

includes emissions limits, schedules of 

compliance, and other measures for 

sources in that state for purposes of 

visibility protection under 169A is not 

the only possible means to satisfy the 

requirements of CAA section 

110(a)(2)(D)(i)(II). States can meet 

section 110(a)(2)(D)(i)(II) by adopting 

emissions limits that were promised as 

part of the regional planning process. A 

RH SIP submittal including BART 

controls on subject to BART sources can 

also meet the requirements of section 

110(a)(2)(D)(i)(II). Arkansas chose to 

take both of these approaches by 

adoption of their promised CENRAP 

emissions reductions in their BART 

determinations as submitted in their RH 

SIP under Arkansas Chapter 15, 

Regulation 19. 

This approach does not give one state 

the power to control another state’s RH 

SIP decisions including its BART 

determinations. Each individual state 

member of the regional planning 

committee has the autonomy to make 

their own decisions on how they are 

going to reduce their state’s emissions 

and contribute to the overall group’s 

effort to reduce RH in the region. We are 

abiding by Arkansas’s decision to have 

its BART determinations be 

representative of promised emission 

reductions relied upon by other states. 

As discussed previously, by us 

disapproving some of Arkansas’s BART 

determinations, the relied-upon 

emissions reductions used in the 

development of other CENRAP member 

state RPGs and RH SIPs will not occur. 

Therefore, we are partially approving 

and partially disapproving the portion 

of the Arkansas Interstate Transport SIP 


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submittal that addresses the visibility 

requirement of section 110(a)(2)(D)(i)(ii) 

that emissions from Arkansas sources 

not interfere with measures required in 

the SIP of any other state under part C 

of the CAA to protect visibility. 

Comment: Based upon EPA’s 2006 

Interstate Transport Guidance, 

conclusions regarding whether 

emissions from any one state could 

interfere with measures of neighboring 

states to protect visibility can only be 

reached when a neighboring state’s RH 

SIP has been approved. This has not 

occurred. In addition, the 2006 

Interstate Transport Guidance provides 

that a state satisfies the requirements of 

the visibility component of the 

interstate transport SIPs by submitting 

an Interstate Transport SIP confirming 

that it is not possible at the time of that 

submission to assess whether a state’s 

emissions would interfere with 

measures required to protect visibility 

in the applicable SIP for another state 

and submit a RH SIP at a later date and 

approved by EPA. This is what 

Arkansas did. In keeping with the 2006 

Guidance, EPA should instead approve 

Arkansas’s 2007 Interstate Transport SIP 

and confine its action on visibility 

impairment to proceeding on the state’s 

RH SIP and not act on section 

110(a)(2)(D)(i)(II) until the state’s RH SIP 

is approved. 

Response: Our guidance on 

submissions in August of 2006 states 

that ‘‘at this time point and time,’’ it is 

not possible to assess whether emissions 

from sources in the state would interfere 

with measures in the SIPs of other states 

until RH SIPs are submitted and 

approved. At the time of the writing of 

the 2006 Guidance, we mistakenly 

assumed that all states would submit 

RH SIPs in December of 2007, as 

required by the RHR, and mistakenly 

assumed that all such submissions 

would meet applicable RH program 

requirements and therefore be approved 

shortly thereafter. This did not happen. 

Thus, our premise, as stated in the 2006 

Guidance, that it would be appropriate 

to await submission and approval of 

such RH SIPs before evaluating SIPs for 

compliance with section 

110(a)(2)(D)(i)(II), was in error. This is 

especially true in light of the timing 

requirements of section 110(a)(1) which 

specifies that SIP submissions to 

address section 110(a)(2)(D)(i), 

including the visibility prong of that 

section, must be made within three 

years after the promulgation of a new or 

revised NAAQS. Our 2006 Guidance 

was clearly intended to make 

recommendations that were relevant at 

that point in time, and subsequent 

events have made it unsuitable to delay 

this action regarding Arkansas’s 

emissions interfering with other state’s 

visibility measures before all RH SIPs 

affected by Arkansas emissions are 

approved. We must therefore act upon 

Arkansas’s submission in light of the 

actual facts, and in light of the statutory 

requirements of section 110(a)(2)(D)(i). 

In order to evaluate whether the state’s 

SIP currently in fact contains provisions 

sufficient to prevent the prohibited 

impacts on the required programs of 

other states, we are obligated to consider 

the current circumstances and 

investigate the levels of controls at 

Arkansas sources and whether those 

controls are or are not sufficient to 

prevent such impacts. Here, as 

explained earlier, Arkansas promised 

emission reductions from BART eligible 

sources and had those emissions 

reductions included in the CENRAP 

modeling that other states are relying on 

in developing their RPGs and RH SIPs. 

Because we are disapproving some of 

Arkansas’s BART determinations, as 

previously discussed, Arkansas will not 

meet its CENRAP emission reduction 

commitments relied upon by other 

states. Thus, Arkansas’s sources will 

interfere with other state’s visibility 

measures. 

Comment: The EPA’s proposed rule is 

incorrect in its conclusion that the 1997 

promulgation of new or revised NAAQS 

for PM2.5 and ozone created an 

obligation in the part of Arkansas (or 

any other state) to submit a section 

110(a)(2)(D)(i)(II) SIP revision with 

respect to visibility protection. 

Promulgation or revision of any NAAQS 

is entirely unrelated to the Part C 

visibility SIP requirements. The only 

additional SIP obligations with respect 

to section 110(a)(2)(D)(i)(II) and new or 

revised NAAQS are NAAQS attainment 

and maintenance. No obligation to 

address Part C visibility components of 

a SIP arises merely as a result of 

NAAQS promulgation or revision. The 

EPA should conclude that the 

promulgation of revised ozone and 

PM2.5 NAAQS creates no obligation on 

the part of any state to submit any 

section 110(a)(2)(D)(i)(II) SIP revision 

with respect to visibility protection. 

Response: We disagree. Reduced 

visibility is an effect of air pollution, 

and the emissions of PM2.5 and ozone 

and its precursors can contribute to 

visibility impairment. SIP planning for 

the control of these pollutants on the 

promulgation of a new NAAQS will 

therefore implicate control measures 

and issues relating to visibility. CAA 

section 110(a)(1) therefore requires 

implementation plans submitted in the 

wake of a newly promulgated NAAQS 

to address whether the state has 

adequate provisions to prevent 

interference with the efforts of other 

states to protect visibility. The 

obligation to address Part C visibility 

components expressly follows from the 

language of section 110(a) concerning 

when plans must be submitted and what 

each implementation plan must contain. 

Comment: The EPA mistakenly refers 

to the ‘‘Interstate Transport SIP’’ in its 

proposed disapproval of a portion of the 

Arkansas Interstate Transport SIP that 

addresses the visibility requirement of 

section 110(a)(2)(D)(i)(II) that emissions 

from Arkansas sources not interfere 

with other state’s visibility protection 

programs, but it is more accurately 

referred to as an ‘‘Infrastructure SIP.’’ In 

addition, the EPA failed to include in its 

proposed disapproval that it did not 

immediately require the state to make 

these SIP submittals. When EPA was 

sued for not having these submittals, the 

EPA issued its finding of failure notices 

to all states. If these SIPs had been 

required and submitted upon 

promulgation of the 1997 revision to the 

NAAQS for 8-hour ozone, it is unlikely 

that the RH program would have been 

considered an element of a typical 

‘‘Infrastructure SIP.’’ 

Response: Interstate Transport SIPs 

and Infrastructure SIPs address SIP 

requirements under section 110 under 

the CAA which requires states to adopt 

and submit to EPA a SIP that includes 

elements 110(a)(2)(A) through (M) 

within three years after the 

promulgation or revision of a NAAQS. 

The EPA has requested states to submit 

their SIP separately addressing Section 

110 Infrastructure requirements and 

Section 110 Interstate Transport 

requirements. However, this does not 

have a legal effect on the contents of the 

SIP submittal. Section 110(a)(2)(D)(i) 

elements are reviewed at the same legal 

standard whether the section 

110(a)(2)(D)(i) elements are submitted as 

part of an Interstate Transport SIP or an 

Infrastructure SIP submittal. 

At issue is Arkansas’s requirement to 

submit a SIP that addresses the 1997 

revision to the NAAQS for 8-hour ozone 

and PM2.5. On July 18, 1997, the EPA 

promulgated new NAAQS for eight-hour 

ozone and for PM2.5. Section 110(a)(1) of 

the CAA requires states to submit new 

SIPs to provide for the implementation, 

maintenance, and enforcement of new 

or revised NAAQS. SIPs for a new or 

revised NAAQS must contain adequate 

provisions to address interstate 

transport of air pollution, pursuant to 

section 110(a)(2)(D)(i). The Clean Air 

Act requires states to submit SIPs within 

three years of promulgation of a new or 

revised NAAQS. This duty to submit a 

SIP that addresses NAAQS revisions 


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14670 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

228H.R. Rep. No. 95–294 at 204 (1977). 

pursuant to section 110(a)(2)(D)(i) is an 

affirmative obligation under the CAA 

and is not dependent upon whether a 

state is notified of its obligation or 

issued a finding of failure to act as EPA 

did in 2005. 

If Arkansas had acted promptly in 

1997 to address section 110(a)(2)(D)(i) 

for ozone and PM2.5, Arkansas would 

still have had to consider RH in its SIP 

submittal. The visibility provisions of 

the CAA gave notice to the States that 

they needed to address interstate 

transport of visibility impairing 

pollutants through RH. Back in 1977 

when Congress enacted the visibility 

provisions of the CAA, Congress 

expressed concern with ‘‘haze’’ from 

‘‘regionally distributed sources 228 ’’ and 

concluded that additional provisions 

were needed to ‘‘remedy the visibility 

problem.’’ Congress amended the 

visibility provisions in 1990 to more 

specifically address interstate transport 

of air pollutants and RH. Section 169B 

created visibility transport regions to 

address the interstate transport of air 

pollutants from one or more states that 

contribute significantly to visibility 

impairment in class I areas. Under CAA 

169B, each visibility transport region 

would have a visibility transport 

commission that was required to study 

adverse impacts on visibility and 

recommend regulations to address long 

range strategies for addressing regional 

haze. In keeping with the visibility 

provisions of the CAA, EPA has 

determined that states may be able to 

satisfy the requirements of CAA section 

110(a)(2)(D)(i)(II) with a state relying on 

the analysis conducted by a visibility 

transport commission to ensure that 

emissions from sources within the state 

are not interfering with the visibility 

programs of other states, as 

contemplated in section 

110(a)(2)(D)(i)(II) or an approved RH 

SIP. 

Comment: It is an abuse of 

administrative procedures for EPA to 

use its proposed disapproval of the 

BART elements of the Arkansas RH SIP 

as the basis for not approving a previous 

SIP submittal upon which it should 

have already acted. There is no reason 

to disapprove any portion of the 

previous submittal as the language 

stating that Arkansas would rely on the 

RH regulations to satisfy the section 

110(a)(2)(D)(i)(II) is still valid. 

Therefore, EPA should approve the 

Arkansas Interstate Transport SIP. 

Response: As previously discussed, 

we are acting on section 

110(a)(2)(D)(i)(II) based on our 

disapproval of some of the BART 

determinations of the RH SIP submittal 

since it was Arkansas that represented 

to other CENRAP member states, and 

included in the CENRAP modeling, 

emissions reductions from BART 

controls on Arkansas sources subject to 

BART. CENRAP states have relied on 

those representations in developing 

their RH SIPs and RPGs. If Arkansas 

cannot deliver those emission 

reductions relied on by other states, 

those emission reductions will interfere 

with the CENRAP member state 

visibility programs. While the Arkansas 

Interstate Transport SIP statement that it 

relies on the RH regulations to satisfy 

the section 110(a)(2)(D)(i)(II) is still true, 

we are obligated to disapprove a portion 

of the Interstate Transport SIP because 

we are finding that Arkansas is not 

satisfying its obligations under the RH 

regulations and causing emissions from 

Arkansas to interfere with other states’ 

visibility programs. 

Comment: The EPA should approve 

the Arkansas Interstate Transport SIP. In 

developing their RH SIPs and RPGs, 

Arkansas and potentially impacted 

states collaborated through the 

CENRAP. Emission reductions for the 

CENRAP states are scheduled to be fully 

realized by 2018. Presumably, EPA will 

have approved some version of an 

Arkansas SIP by 2013, and any such 

submittal would have at least the 

amount of BART reductions provided 

for in current SIP submittals. With a 

compliance schedule of no more than 5 

years after EPA approval, these 

reductions would still be realized by 

2018. 

Response: Arkansas is assuming that 

EPA will have approved Arkansas’s SIP 

provisions by 2013 that address the 

promised BART emissions reductions to 

the CENRAP. The EPA cannot base 

decisions on potential future actions. 

Our rulemaking is limited to the events 

that have occurred at the time of 

rulemaking. It is not a foregone 

conclusion that Arkansas will submit 

and EPA will have approved SIP 

provisions with the promised emissions 

reductions by 2013, much less that 

those emissions reductions would be 

realized by 2018. 

Comment: In April 2008, Arkansas 

submitted an Interstate Transport SIP 

revision to address its Good Neighbor 

CAA obligations triggered by the 1997 

8-hour ozone and PM2.5 NAAQS. 

Section 110(k)(1)(B) of the CAA requires 

EPA to act on a SIP revision within 18 

months. EPA’s proposal does not 

address why EPA violated the statutory 

deadline by waiting nearly two years 

after the deadline in the CAA to take 

action on Arkansas’s April 2008 

Interstate Transport SIP submission. 

Response: We acknowledge that we 

are late in acting on Arkansas’s 

Interstate Transport SIP revisions 

regarding its ‘‘Good Neighbor’’ CAA 

obligations triggered by the 1997 8-hour 

ozone and PM2.5 NAAQS. We are 

working diligently to address all of 

these SIP submittals as quickly and 

expeditiously as possible. With this 

action today finalizing our partial 

approval and partial disapproval of 

Arkansas’s Interstate Transport SIP 

addressing impairment of other states’ 

visibility measures, we are fulfilling our 

statutory obligation under section 

110(a)(2)(D)(i)(II) of the CAA. 

Comment: Like Oregon and Colorado, 

Arkansas submitted an Interstate 

Transport SIP predicated on a RH SIP to 

address section 110(a)(2)(D)(i)(II). 

However, EPA has treated Arkansas 

differently that Oregon and Colorado in 

meeting the requirements of section 

110(a)(2)(D)(i)(II). For Oregon, despite 

the discrepancies between what was 

assumed by the RPO and the emission 

reductions included in Oregon’s RH SIP, 

EPA approved the visibility component 

of Oregon’s Interstate Transport SIP 

after reviewing the RPO’s 

photochemical modeling emissions 

projections finding that the emissions 

reductions included in Oregon’s RH SIP 

are ‘‘approximately equal’’ to those 

assumed by neighboring states. For 

Colorado, in evaluating the visibility 

component of Colorado’s Interstate 

Transport SIP, EPA did not consider 

Colorado’s RH SIP because it had not 

been approved. Instead, EPA conducted 

a ‘‘weight-of-evidence’’ evaluation to 

assess the increase in Colorado sulfates 

and nitrates emissions above what 

neighboring states assumed, and 

concluded that ‘‘Colorado has a minimal 

impact on visibility’’ at Class I areas in 

neighboring states. There is no 

indication that EPA performed such 

analyses in its evaluation of the 

visibility component of the Arkansas 

Interstate Transport SIP, and instead 

held that any discrepancy between the 

emissions reductions included in a 

state’s RH SIP and the emissions 

reductions assumed by neighboring 

states is equivalent to ‘‘interfering’’ with 

the measures of other states to protect 

visibility. This is similar to EPA’s 

interpretation of the visibility 

component of the Good Neighbor 

Provision in its evaluations of the 

Interstate Transport SIPs for New 

Mexico, Oklahoma, and North Dakota. 

The EPA has failed to identify a 

threshold of deviation from the 

CENRAP assumptions in a state’s RH 

SIP in order to trigger disapproval of 

visibility provisions of a state’s 


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229See letter from Mike Bates, Air Division 

Director, Arkansas Department of Environmental 

Quality, to Eddie Terrill, Air Division Director, 

Oklahoma Department of Environmental Quality, 

dated August 17, 2007. This letter is found in 

Appendix 10.3 of the Arkansas RH SIP. 

Interstate Transport SIP. In addition, the 

EPA has also failed to address why the 

criteria EPA used to evaluate the 

visibility component of Arkansas’s 

Interstate Transport SIP is different from 

that used to evaluate the Interstate 

Transport SIPs of other states, in 

particular those of Oregon and 

Colorado. 

Response: The EPA disagrees that our 

proposed action on the visibility 

component of Arkansas’s Interstate 

Transport SIP is inconsistent with our 

actions on the Interstate Transport SIPs 

of Oregon and Colorado. As described in 

the comment, EPA approved the 

visibility component of Oregon’s 

Interstate Transport SIP after reviewing 

the RPO’s photochemical modeling 

emissions projections and finding that 

the emissions reductions included in 

Oregon’s RH SIP are ‘‘approximately 

equal’’ to those assumed by neighboring 

states. In the case of Arkansas, we are 

disapproving nearly all of the State’s 

BART determinations for SO2 and NOX

(and some PM) emissions limits that 

Arkansas promised as part of its 

membership to the CENRAP. Those 

emissions limits have been included in 

the 2018 CENRAP modeling, and other 

states are relying on this modeling in 

developing their RPGs and RH SIPs. 

However, as discussed previously, with 

our disapproval, these anticipated 

reductions will not be taking place and 

thus the emissions of SO2, NOX and PM 

from Arkansas will interfere with other 

states’ visibility programs. With the 

disapproval of certain BART 

determinations and Arkansas’s 

promised BART emissions reductions 

included in the CENRAP process, there 

is a large discrepancy between the 

RPO’s photochemical modeling 

emissions projections (which is 

reflective of the emissions reductions 

other states relied on in their RH SIPs) 

and the emissions reductions that will 

actually be taking place (i.e. the State’s 

BART determinations that we find 

satisfy the RH requirements). 

The comment points out that EPA did 

not consider Colorado’s RH SIP in 

evaluating the visibility component of 

Colorado’s Interstate Transport SIP 

because it had not been approved yet. 

EPA points out that at the time we 

approved Colorado’s Interstate 

Transport SIP, we had not taken any 

kind of action on the Colorado RH SIP. 

In fact, we haven’t taken any kind of 

action on the Colorado RH SIP to date. 

Therefore, in order to take an informed 

and appropriate action on the Colorado 

Interstate Transport SIP, EPA conducted 

a ‘‘weight-of-evidence’’ evaluation to 

assess the increase in Colorado sulfates 

and nitrates emissions above what 

neighboring states assumed. Based on 

the results of that evaluation, we 

concluded that Colorado has a minimal 

impact on visibility at Class I areas in 

neighboring states. This is not the case 

with Arkansas. As explained in 

Appendix A to the TSD for our 

proposed rulemaking on the Arkansas 

RH SIP, the CENRAP’s photochemical 

modeling clearly shows that Arkansas 

emissions are causing visibility 

impairment at the Hercules Glades and 

Mingo Class I areas in Missouri. As 

explained above, we proposed to 

disapprove nearly all of Arkansas’s SO2

and NOX (and some PM) BART 

determinations. In light of the large 

number (and percentage) of SO2 and 

NOX emissions reductions that other 

states relied on, we do not believe that 

it is necessary at this time to do any 

other analysis to further support our 

partial disapproval of the visibility 

component of Arkansas’s Interstate 

Transport SIP since Arkansas has 

promised emissions reductions for 

subject to BART sources, and included 

them in the CENRAP modeling that 

other states are relying on in developing 

their RPGs and RH SIPs, but the 

emissions reductions for the 

disapproved BART determinations will 

not occur. 

Comment: None of the BART 

determinations in the Arkansas RH SIP 

should be approved by EPA, and 

accordingly EPA should fully 

disapprove the Arkansas Interstate 

Transport SIP for visibility protection. 

In 2018, the contribution from Arkansas 

sources to visibility impairment in other 

states (including Missouri and 

Oklahoma) are projected to increase 

from 2002 levels. In recognition of this, 

the State of Oklahoma asked for 

additional emission reductions from 

Arkansas sources, but Arkansas did not 

agree that any further emissions 

reductions were necessary (2007 Letter 

from ADEQ to ODEQ, Appendix 11.2 of 

Arkansas RH SIP). Therefore, it is 

unlikely that the BART emission limits 

adopted by Arkansas are sufficient to 

ensure that sources in Arkansas will not 

interfere with Oklahoma’s ability to 

ensure reasonable progress toward 

attaining the national visibility goal at 

the Wichita Mountains Class I area. 

Response: Arkansas proposed to 

comply with the requirements of the 

Interstate Transport SIP for visibility 

protection through reductions in 

emissions from BART eligible sources. 

This is in keeping with the CAA and is 

acceptable to EPA. As explained above, 

we are partially disapproving 

Arkansas’s Interstate Transport SIP for 

visibility protection because Arkansas 

proposed to meet these requirements 

through the BART determinations that 

we are disapproving and therefore the 

relied-upon emissions reductions will 

not occur. The comment is right that in 

2018, the contribution from Arkansas 

sources to visibility impairment in other 

states (including Oklahoma and 

Missouri) is projected to increase from 

2002 levels though minimally. However, 

those projected emissions increases are 

due to Arkansas’s planned building of 

new facilities which will emit visibility 

impairing pollutants. The EPA does 

note that one of the proposed plants 

included in this projection has recently 

been cancelled and thus Arkansas 

projected emissions increases for 2018 

will be less than projected in their RH 

SIP. 

For purposes of noninterference with 

other states’ visibility programs, 

Arkansas met with other regional states 

and promised that it would contribute a 

certain portion of the emissions 

reductions to address RH for the region. 

Although Oklahoma initially believed 

that emissions from Arkansas sources 

are impacting visibility at Wichita 

Mountains and that it might be 

necessary for Arkansas to commit to 

additional emissions reductions, 

Arkansas responded to ODEQ’s 

concerns with a letter dated August 17, 

2007, explaining that based on 

photochemical modeling, ADEQ had 

calculated that the total visibility impact 

from all sources in Arkansas at Wichita 

Mountains is 0.2 dv.229 Furthermore, in 

section X.A. of the Oklahoma RH SIP 

submitted to EPA, ODEQ references the 

August 17, 2007 letter sent by ADEQ 

and states that it is in agreement with 

the projected emissions reductions from 

Arkansas and all other states with 

which it consulted with regard to 

visibility impairment at Wichita 

Mountains. For Missouri’s consultation 

with Arkansas regarding emissions 

reductions, Arkansas and Missouri met 

in a joint consultation (see our TSD and 

Arkansas RH SIP), where both states 

agreed upon the amount of emission 

reductions each state would provide in 

order for both states to meet the 

visibility requirements of the CAA. All 

the states Arkansas consulted with 

accepted Arkansas’s committed 

emissions reductions and have based 

their RPGs and RH SIPs accordingly 

with the idea that regional states can 

attain natural visibility conditions for 

class I areas within their boundaries by 

2064 based off of this information. This 


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is consistent with the intent of the 

visibility program under the CAA to 

allow the states under a regional 

planning committee to determine the 

best way to address visibility 

impairment for the region. Therefore, 

we find that partially approving and 

partially disapproving Arkansas’s 

Interstate Transport SIP with regards to 

interference with other states’ visibility 

measures is appropriate since Arkansas, 

working in conjunction with other states 

in the regional planning organization, 

committed to certain emissions 

reductions of subject to BART sources 

which Arkansas can no longer meet 

because we are disapproving a portion 

of Arkansas’s BART determinations, and 

therefore the relied-upon emissions 

reductions will not occur. 

H. Other Comments 

Comment: EPA did not propose a FIP 

concurrently with its proposal to 

partially disapprove the Arkansas RH 

SIP, thus being inconsistent with what 

EPA has recently proposed for other 

states. When EPA proposed to partially 

approve and partially disapprove the 

RH SIPs of North Dakota and Oklahoma, 

at the same time EPA proposed FIP 

requirements for the components of the 

RH SIP that EPA proposed to 

disapprove (see 76 FR 58570 and 76 FR 

16168). Arkansas submitted its RH SIP 

earlier than most other states, including 

at least 18 months before North Dakota 

and Oklahoma, yet EPA did not propose 

a FIP concurrently with its proposed 

partial disapproval of the Arkansas RH 

SIP and it appears it will be several 

years before the facilities in the State 

that are contributing to regional haze 

install pollution controls and reduce 

emissions. The residents and visitors to 

the State of Arkansas are getting the 

short shrift from EPA compared to the 

residents and visitors of these other 

states. This is very important 

considering that the majority of 

Arkansas’s coal-fired power plants have 

absolutely no SO2 controls, and at this 

point it is not clear that the units will 

be subject to any regulations other than 

BART that would require the 

installation of scrubbers. EPA should 

not delay any longer in proposing a FIP 

to address RH in Arkansas. 

Response: While we appreciate the 

concerns described in the comment 

regarding visibility impairment in 

Arkansas’s Class I areas, we note that 

the CAA section 110(c) requires that 

EPA promulgate a FIP at any time 

within 2 years after EPA disapproves a 

SIP in whole or in part. As explained in 

our proposed rulemaking, at this time 

we are not promulgating a FIP for the 

portions of the Arkansas RH SIP we are 

disapproving because ADEQ has 

expressed its intent to revise the 

Arkansas RH SIP by correcting the 

deficiencies in the SIP. We are electing 

to not promulgate a FIP at this time in 

order to provide Arkansas time to 

correct these deficiencies. While EPA 

has promulgated FIPs concurrently to 

address the deficiencies of states’ RH 

SIPs, there is no statutory requirement 

for EPA to do so. Unless we receive a 

SIP revision from the State that 

addresses the flaws we identified in our 

proposed rulemaking and in this final 

action and satisfies all the regulatory 

and statutory requirements and we 

approve it within 2 years of our final 

partial disapproval of the Arkansas RH 

SIP, EPA is required to promulgate a FIP 

within 2 years of our final partial 

disapproval of the SIP to address the 

components of the SIP we disapproved. 

Comment: The State is required to 

document the technical basis, including 

modeling, monitoring, and emissions 

information, on which the State is 

relying to determine its apportionment 

of emission reduction obligations 

necessary for achieving reasonable 

progress in each mandatory Class I 

Federal area it affects (see 40 CFR 

51.308(d)(3)(iii)). Arkansas relied on the 

CENRAP modeling and emission 

inventories to meet this requirement, 

and therefore Arkansas itself did not 

provide much of the technical basis for 

the modeling and emission inventories. 

EPA has posted some of the relevant 

CENRAP documents to its docket for the 

Arkansas RH rulemaking, but not all 

relevant documents have been provided. 

There is one document of facilityspecific emission projections for 2018 

we wanted to evaluate but were unable 

to locate. Only graphical representations 

of each state’s emissions by source 

category are provided in the Technical 

Support Document for the CENRAP 

modeling. The CENRAP Web site is no 

longer being maintained and no 

emission inventory documents are 

available on that site. We contacted EPA 

Region 6 to obtain this document, but 

EPA was unable to locate it. A review 

of the 2018 facility-specific emission 

inventory is imperative in reviewing the 

2018 modeling projections and the LTS 

for Arkansas as well as the LTS of other 

CENRAP states to determine if the LTS 

for those states include enforceable 

emission limitations that correspond to 

the 2018 emissions projections for each 

facility. A review of the 2018 facilityspecific emissions inventory is also 

necessary to determine whether all 

visibility-impairing sources were 

modeled and whether the emissions 

modeled for all sources were reasonable 

given the emission reduction 

requirements on the books and 

forthcoming by 2018. EPA should not 

approve the Arkansas RH SIP because it 

does not include the technical basis that 

Arkansas is relying on to show that it 

will achieve reasonable progress 

towards reaching natural background 

visibility conditions at its Class I areas. 

Also, EPA should not be proposing to 

find the 2018 emissions inventory 

‘‘acceptable,’’ when it does not have the 

facility-specific emission projections for 

2018. 

Response: The full reference to 40 

CFR 51.308(d)(3)(iii) is the following: 

‘‘The State must document the technical 

basis, including modeling, monitoring and 

emissions information, on which the State is 

relying to determine its apportionment of 

emission reduction obligations necessary for 

achieving reasonable progress in each 

mandatory Class I Federal area it affects. The 

State may meet this requirement by relying 

on technical analyses developed by the 

regional planning organization and approved 

by all State participants. The State must 

identify the baseline emissions inventory on 

which its strategies are based. The baseline 

emissions inventory year is presumed to be 

the most recent year of the consolidated 

periodic emissions inventory.’’ 

A full reading of 40 CFR 

51.308(d)(3)(iii) demonstrates that the 

requirement for the State to document 

the technical basis on which it is relying 

to determine its apportionment of 

emission reduction obligations 

necessary for achieving reasonable 

progress in each mandatory Class I 

Federal area it affects is to ensure that 

potentially affected states have all the 

technical information they need to be 

able to determine whether they agree 

with the State’s apportionment of 

emission reduction obligations. As 

pointed out in the comment, Arkansas 

elected to meet the requirement under 

40 CFR 51.308(d)(3)(iii) to document the 

technical basis for its RH SIP by relying 

on technical analyses developed by the 

CENRAP and approved by all State 

participants. Through the CENRAP 

process, all affected states agreed with 

Arkansas’s apportionment of emission 

reduction obligations and these were 

included in the CENRAP 2018 

emissions inventory modeling on which 

all the CENRAP member states are 

relying on to develop their RPGs and 

LTS. Since the technical analyses 

developed by the RPOs are often very 

extensive, it would be unreasonable to 

expect states to include all these 

documents as part of their RH SIPs. 

Since Arkansas relied on technical 

analyses developed by the CENRAP and 

approved by all State participants and 

properly identified the baseline 


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230Sierra Club v. Lisa Jackson, Case No. 1:10–CV– 

02112–JEB. 

emissions inventory on which its 

strategies are based, the State satisfied 

the requirements under 40 CFR 

51.308(d)(3)(iii). This is supported by 

2018 CENRAP modeling data results 

indicating that two Class I areas outside 

of Arkansas (Missouri Class I areas— 

Mingo Wilderness Area and Hercules 

Glades Wilderness Area), where 

Arkansas sources have a significant 

impact, are projected to achieve the 

RPGs in 2018. 

During the comment period, we 

provided the commenter with most of 

the information requested (including all 

the emission summary spreadsheet files 

we had), with the exception of two 

emission inventory summary files. 

Unfortunately, the document of facilityspecific emission projections for 2018 

referenced in the comment consists of 

two SMOKE electronic emissions 

processing reports that can be viewed in 

a very large electronic database using 

database software. However, these 

reports are too large to export to a 

spreadsheet, as had been done to 

generate other reports within the 

database, because it includes the daily 

point emissions by facility projected in 

2018 for all the facilities in the CENRAP 

states. We had most of the SMOKE 

emission reports, which we did provide 

to the commenter’s contractor. We did 

not consider these few missing emission 

reports to be critical or necessary to our 

review because we realized for reasons 

outside of the data contained in the 

missing reports that we would have to 

propose partial disapproval of the 

Arkansas RH SIP (including LTS and 

BART determinations). It is not practical 

to require that the State submit or 

include every possible electronic file 

that supports the RPO modeling as this 

is several Terabytes of data and most of 

the data has been submitted or is posted 

on Web sites or ftp sites or available on 

request. We believe this is the only 

practical way to address the large 

volumes of data necessary for the 

development of multistate regional haze 

modeling analysis. Unfortunately, as 

noted in the comment, the CENRAP 

Web site is no longer being maintained 

and no emission inventory documents 

are available on that site. In general, the 

former CENRAP members have been 

very supportive in providing 

information when requested. It was only 

due to specific issues that we were not 

able to provide the information for these 

two SMOKE emission reports when 

requested. We will continue to work to 

address this issue as we work with 

Arkansas on development of an 

approvable Regional Haze SIP. Again we 

do not believe that these particular files 

were critical or necessary to our 

conclusion that the Arkansas SIP should 

be partially approved and partially 

disapproved. 

I. Comments Requesting an Extension to 

the Public Comment Period 

We received several comments 

requesting that the comment period be 

extended by an additional 60 days. 

Response: Originally the comment 

period for our proposal was scheduled 

to close on November 16, 2011. In 

response to requests we extended the 

public comment period to December 22, 

2011. In doing so, we took into 

consideration how an extension might 

affect our ability to consider comments 

received on the proposed action and 

still comply with the terms of a consent 

decree we have with Sierra Club.230

IV. Statutory and Executive Order 

Reviews 

Under the Clean Air Act, the 

Administrator is required to approve a 

SIP submission that complies with the 

provisions of the Act and applicable 

Federal regulations. 42 U.S.C. 7410(k); 

40 CFR 52.02(a). Thus, in reviewing SIP 

submissions, EPA’s role is to act on state 

law as meeting Federal requirements 

and does not impose additional 

requirements beyond those imposed by 

state law. 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

This action is not a ‘‘significant 

regulatory action’’ under the terms of 

Executive Order 12866 (58 FR 51735, 

October 4, 1993) and is therefore not 

subject to review under Executive 

Orders 12866 and 13563 (76 FR 3821, 

January 21, 2011). 

B. Paperwork Reduction Act 

This action does not impose an 

information collection burden under the 

provisions of the Paperwork Reduction 

Act, 44 U.S.C. 3501 et seq, because this 

SIP action under section 110 of the CAA 

will not in-and-of itself create any new 

information collection burdens but 

simply approves or disapproves certain 

State requirements for inclusion into the 

SIP. Burden is defined at 5 CFR 

1320.3(b). 

C. Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) 

generally requires an agency to conduct 

a regulatory flexibility analysis of any 

rule subject to notice and comment 

rulemaking requirements unless the 

agency certifies that the rule will not 

have a significant economic impact on 

a substantial number of small entities. 

Small entities include small businesses, 

small not-for-profit enterprises, and 

small governmental jurisdictions. For 

purposes of assessing the impacts of 

today’s rule on small entities, small 

entity is defined as: (1) A small business 

as defined by the Small Business 

Administration’s (SBA) regulations at 13 

CFR 121.201; (2) a small governmental 

jurisdiction that is a government of a 

city, county, town, school district or 

special district with a population of less 

than 50,000; and (3) a small 

organization that is any not-for-profit 

enterprise which is independently 

owned and operated and is not 

dominant in its field. 

After considering the economic 

impacts of today’s rule on small entities, 

I certify that this action will not have a 

significant impact on a substantial 

number of small entities. This rule does 

not impose any requirements or create 

impacts on small entities. This SIP 

action under section 110 of the CAA 

will not in-and-of itself create any new 

requirements but simply approves or 

disapproves certain State requirements 

for inclusion into the SIP. Accordingly, 

it affords no opportunity for EPA to 

fashion for small entities less 

burdensome compliance or reporting 

requirements or timetables or 

exemptions from all or part of the rule. 

The fact that the CAA prescribes that 

various consequences (e.i. emission 

limitations) may or will flow from this 

action does not mean that EPA either 

can or must conduct a regulatory 

flexibility analysis for this action. 

Therefore, this action will not have a 

significant economic impact on a 

substantial number of small entities. 

D. Unfunded Mandates Reform Act 

This action contains no Federal 

mandates under the provisions of Title 

II of the Unfunded Mandates Reform 

Act of 1995 (UMRA), 2 U.S.C. 1531– 

1538 for State, local, or tribal 

governments or the private sector. EPA 

has determined that the disapproval 

action does not include a Federal 

mandate that may result in estimated 

costs of $100 million or more to either 

State, local, or tribal governments in the 

aggregate, or to the private sector. This 

action merely approves or disapproves 

pre-existing requirements under State or 

local law, and imposes no new 

requirements. Accordingly, no 

additional costs to State, local, or tribal 

governments, or to the private sector, 

result from this action. 


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E. Executive Order 13132, Federalism 

Executive Order 13132, entitled 

‘‘Federalism’’ (64 FR 43255, August 10, 

1999), requires EPA to develop an 

accountable process to ensure 

‘‘meaningful and timely input by State 

and local officials in the development of 

regulatory policies that have federalism 

implications.’’ ‘‘Policies that have 

federalism implications’’ is defined in 

the Executive Order to include 

regulations that 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.’’ 

This action does not have federalism 

implications. It will not have substantial 

direct effects on the States, on the 

relationship between the national 

government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government, as specified in 

Executive Order 13132, because it 

merely approves or disapproves certain 

State requirements for inclusion into the 

SIP and does not alter the relationship 

or the distribution of power and 

responsibilities established in the CAA. 

Thus, Executive Order 13132 does not 

apply to this action. 

F. Executive Order 13175, Coordination 

With Indian Tribal Governments 

This action does not have tribal 

implications, as specified in Executive 

Order 13175 (65 FR 67249, November 9, 

2000), because the SIP submittals EPA 

is approving or disapproving would not 

apply in Indian country located in the 

state, and EPA notes that it will not 

impose substantial direct costs on tribal 

governments or preempt tribal law. 

Thus, Executive Order 13175 does not 

apply to this action. 

G. Executive Order 13045, Protection of 

Children From Environmental Health 

Risks and Safety Risks 

EPA interprets Executive Order 13045 

(62 FR 19885, April 23, 1997) as 

applying only to those regulatory 

actions that concern health or safety 

risks, such that the analysis required 

under section 5–501 of the Executive 

Order has the potential to influence the 

regulation. This action is not subject to 

Executive Order 13045 because it 

because it is not an economically 

significant regulatory action based on 

health or safety risks subject to 

Executive Order 13045 (62 FR 19885, 

April 23, 1997). This SIP action under 

section 110 of the CAA will not in-andof itself create any new regulations but 

simply approves or disapproves certain 

State requirements for inclusion into the 

SIP. 

H. Executive Order 13211, Actions 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 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (‘‘NTTAA’’), Public Law 

104–113, section 12(d) (15 U.S.C. 272 

note) directs EPA to use voluntary 

consensus standards in its regulatory 

activities unless to do so would be 

inconsistent with applicable law or 

otherwise impractical. Voluntary 

consensus standards are technical 

standards (e.g., materials specifications, 

test methods, sampling procedures, and 

business practices) that are developed or 

adopted by voluntary consensus 

standards bodies. NTTAA directs EPA 

to provide Congress, through OMB, 

explanations when the Agency decides 

not to use available and applicable 

voluntary consensus standards. 

The EPA believes that this action is 

not subject to requirements of section 

12(d) of NTTAA because application of 

those requirements would be 

inconsistent with the CAA. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations 

Executive Order 12898 (59 FR 7629 

(Feb. 16, 1994)) establishes Federal 

executive policy on environmental 

justice. Its main provision directs 

Federal agencies, to the greatest extent 

practicable and permitted by law, to 

make environmental justice 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 minority 

populations and low-income 

populations in the United States. 

EPA lacks the discretionary authority 

to address environmental justice in this 

action. In reviewing SIP submissions, 

EPA’s role is to approve or disapprove 

state choices, based on the criteria of the 

CAA. Accordingly, this action merely 

approves or disapproves certain State 

requirements for inclusion into the SIP 

under section 110 of the CAA and will 

not in-and-of itself create any new 

requirements. Accordingly, it does not 

provide EPA with the discretionary 

authority to address, as appropriate, 

disproportionate human health or 

environmental effects, using practicable 

and legally permissible methods, under 

Executive Order 12898. 

K. Congressional Review Act 

The Congressional Review Act, 5 

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

Business Regulatory Enforcement 

Fairness Act of 1996, generally provides 

that before a rule may take effect, the 

agency promulgating the rule must 

submit a rule report, which includes a 

copy of the rule, to each House of the 

Congress and to the Comptroller General 

of the United States. EPA will submit a 

report containing this action and other 

required information to the U.S. Senate, 

the U.S. House of Representatives, and 

the Comptroller General of the United 

States prior to publication of the rule in 

the Federal Register. A major rule 

cannot take effect until 60 days after it 

is published in the Federal Register. 

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

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

will be effective on April 11, 2012. 

L. Judicial Review 

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

petitions for judicial review of this 

action must be filed in the United States 

Court of Appeals for the appropriate 

circuit by May 11, 2012. Filing a 

petition for reconsideration by the 

Administrator of this final rule does not 

affect the finality of this action for the 

purposes of judicial review nor does it 

extend the time within which a petition 

for judicial review may be filed, and 

shall not postpone the effectiveness of 

such rule or action. This action may not 

be challenged later in proceedings to 

enforce its requirements. See CAA 

section 307(b)(2). 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Incorporation by 

reference, Intergovernmental relations, 

Nitrogen dioxide, Ozone, Particulate 

matter, Reporting and recordkeeping 

requirements, Sulfur dioxides, 

Visibility, Interstate transport of 

pollution, Regional haze, Best available 

retrofit technology. 

Dated: February 13, 2012. 

Al Armendariz, 

Regional Administrator, Region 6. 

40 CFR part 52 is amended as follows: 

PART 52—[AMENDED] 

■ 1. The authority citation for part 52 

continues to read as follows: 

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


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Subpart E—[Amended] 

■ 2. Section 52.170 is amended: 

■ a. In paragraph (c), under the first 

table entitled ‘‘EPA-Approved 

Regulations in the Arkansas SIP,’’ by 

revising the heading for Chapter 15 

under Regulation No. 19 to read 

‘‘Regional Haze’’; by revising the entry 

for Reg. 19.1501; and by adding new 

entries in numerical order for Reg. 

19.1502, Reg. 19.1503, Reg. 19.1504, 

Reg. 19.1505, Reg. 19.1506, and Reg. 

19.1507. 

■ b. In paragraph (e), under the third 

table entitled ‘‘EPA-Approved NonRegulatory Provisions and QuasiRegulatory Measures in the Arkansas 

SIP’’, by adding at the end of the table 

a new entry for ‘‘Interstate Transport for 

the 1997 ozone and PM2.5 NAAQS’’ 

immediately followed by a new entry 

for ‘‘Regional Haze SIP’’. 

The amendments read as follows: 

§ 52.170 Identification of plan. 

* * * * * 

(c) * * * 

EPA-APPROVED REGULATIONS IN THE ARKANSAS SIP 

State citation Title/subject 

State 

approval/ 

effective 

date 

EPA approval date Explanation 

Regulation No. 19: Regulations of the Arkansas Plan of Implementation for Air Pollution Control 

*******

Chapter 15: Regional Haze 

Reg. 19.1501 ........ Purpose ..................... 1/25/2009 3/12/2012 [Insert FR 

page number where 

document begins].

Reg, 19.1502 ........ Definitions .................. 1/25/2009 3/12/2012 [Insert FR 

page number where 

document begins].

Reg. 19.1503 ........ BART Eligible 

Sources.

1/25/2009 3/12/2012 [Insert FR 

page number where 

document begins].

Reg. 19.1504 ........ Facilities Subject-toBART.1/25/2009 3/12/2012 [Insert FR 

page number where 

document begins].

Under (A): The identification of sources subject to BART is 

approved, except for not identifying the 6A and 9A Boilers 

at the Georgia Pacific Crossett Mill, which we find are 

subject to BART. 

Under (B): The requirement for BART installation and operation as expeditiously as practicable, but no later than 5 

years after EPA approval is partially approved and partially disapproved, such that the partial approval is for the 

BART determinations we are approving and the partial 

disapproval is for the BART determinations we are disapproving; and the requirement for BART installation and 

operation no later than 6 years after the effective date of 

the State regulation is disapproved. 

Reg. 19.1505 ........ BART Requirements .. 1/25/2009 3/12/2012 [Insert FR 

page number where 

document begins].

The following portions of Reg. 19.1505 are disapproved: 

(A)(1) and (2), (B), (C), (D)(1) and (2), (E), (F)(1) and (2), 

(G)(1) and (2), (H), (I)(1) and (2), (J)(1) and (2), (K), (L), 

(M)(1), and (N). 

Reg. 19.1506 ........ Compliance Provisions.1/25/2009 3/12/2012 [Insert FR 

page number where 

document begins].

The requirement to demonstrate compliance with the BART 

limits listed in Reg. 19.1505 (A)(1) and (2), (B), (C), 

(D)(1) and (2), (E), (F)(1) and (2), (G)(1) and (2), (H), 

(I)(1) and (2), (J)(1) and (2), (K), (L), (M)(1), and (N) is 

disapproved. 

Reg. 19.1507 ........ Permit Reopening ...... 1/25/2009 3/12/2012 [Insert FR 

page number where 

document begins].

*******

* * * * * 

(e) * * * 

* * * * * 


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14676 Federal Register / Vol. 77, No. 48 / Monday, March 12, 2012 / Rules and Regulations 

EPA-APPROVED NON-REGULATORY PROVISIONS AND QUASI-REGULATORY MEASURES IN THE ARKANSAS SIP 

Name of SIP provision 

Applicable 

geographic or 

nonattainment 

area 

State 

submittal/ 

effective 

date 

EPA approval 

date Explanation 

*******

Interstate Transport for the 1997 

ozone and PM2.5 NAAQS (Noninterference with measures required to protect visibility in any 

other State).

Statewide ...................... 3/28/2008 3/12/2012 [Insert FR 

page number where 

document begins].

Noninterference with measures required to protect visibility in any 

other State partially approved 3/ 

12/12. 

Regional Haze SIP ............................ Statewide ...................... 9/23/2008, 

8/3/2010 

3/12/2012 [Insert FR 

page number where 

document begins].

The following portions are partially 

approved and partially disapproved: 

(a) Identification of affected 

Class I areas.

(a) Identification of best available 

retrofit technology (BART) eligible 

sources and subject to BART 

sources; 

(b) Determination of baseline 

and natural visibility conditions.

(b) requirements for best available 

retrofit technology (BART); 

(c) Determination of the Uniform 

Rate of Progress.

(c) the Arkansas Regional Haze 

Rule; and 

(d) Reasonable progress goal 

consultation and long term 

strategy consultation.

(d) Long Term Strategy. (See 

§ 52.173(a)). 

(e) Coordination regional haze 

and reasonably attributable 

visibility impairment.

(f) Monitoring Strategy and other 

implementation requirements.

(g) Commitment to submit periodic Regional Haze SIP revisions and periodic progress 

reports describing progress towards the reasonable progress 

goals.

(h) Commitment to make a determination of the adequacy of 

the existing SIP at the time a 

progress report is submitted.

(i) Coordination with States and 

Federal Land Managers.

(j) The following best available 

retrofit technology (BART) determinations: PM BART determination for the AEP Flint 

Creek Plant Boiler No. 1; SO2

and PM BART determinations 

for the natural gas firing scenario for the Entergy Lake 

Catherine Plant Unit 4; PM 

BART determinations for both 

the bituminous and sub-bituminous coal firing scenarios 

for the Entergy White Bluff 

Plant Units 1 and 2; and PM 

BART determination for the 

Domtar Ashdown Mill Power 

Boiler No. 1.

■ 3. Section 52.173 is added to read as 

follows: 

§ 52.173 Visibility protection. 

(a) Regional haze. The regional haze 

State Implementation Plan (SIP) 

revisions submitted on September 23, 

2008 and August 3, 2010, and 

supplemented on September 27, 2011 

are partially approved and partially 

disapproved. 

(1) The identification of sources that 

are eligible for Best Available Retrofit 

Technology (BART) is approved, with 

the exception of the 6A Boiler at the 

Georgia-Pacific Crossett Mill, which is 

BART eligible. 

(2) The identification of sources 

subject to BART is approved, with the 

exception of the 6A and 9A Boilers at 

the Georgia-Pacific Crossett Mill, which 

are both subject to BART. 

(3) The following BART 

determinations are disapproved: 

(i) The sulfur dioxide (SO2), nitrogen 

dioxide (NOX), and particulate matter 


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(PM) BART determinations for the 

Arkansas Electric Cooperative 

Corporation Bailey Plant Unit 1 and the 

AECC McClellan Plant Unit 1; 

(ii) The SO2 and NOX BART 

determinations for the American 

Electric Power Flint Creek Plant Boiler 

No. 1; 

(iii) The NOX BART determination for 

the natural gas firing scenario and the 

SO2, NOX, and PM BART 

determinations for the fuel oil firing 

scenario for the Entergy Lake Catherine 

Plant Unit 4; 

(iv) The SO2 and NOX BART 

determinations for both the bituminous 

and sub-bituminous coal firing 

scenarios for the Entergy White Bluff 

Plant Units 1 and 2; 

(v) The BART determination for the 

Entergy White Bluff Plant Auxiliary 

Boiler; 

(vi) The SO2 and NOX BART 

determinations for the Domtar Ashdown 

Mill Power Boiler No. 1; and 

(vii) The SO2, NOX and PM BART 

determinations for the Domtar Ashdown 

Mill Power Boiler No. 2. 

(4) The Arkansas Regional Haze Rule, 

(APCEC Regulation 19, Chapter 15), is 

partially approved and partially 

disapproved such that: 

(i) The requirement under Reg. 

19.104(B) for BART installation and 

operation as expeditiously as 

practicable, but no later than 5 years 

after EPA approval of the Arkansas 

Regional Haze State Implementation 

Plan is partially approved and partially 

disapproved, such that the partial 

approval is for the BART determinations 

we are approving and the partial 

disapproval is for the BART 

determinations we are disapproving; 

(ii) The requirement under Reg. 

19.1504(B) for BART installation and 

operation no later than 6 years after the 

effective date of the State regulation is 

disapproved; 

(iii) Reg. 19.1505 (A)(1) and (2), (B), 

(C), (D)(1) and (2), (E), (F)(1) and (2), 

(G)(1) and (2), (H), (I)(1) and (2), (J)(1) 

and (2), (K), (L), (M)(1), and (N) are 

disapproved; 

(iv) the Reg. 19.1506 requirement to 

demonstrate compliance with the BART 

limits listed in Reg. 19.1505 (A)(1) and 

(2), (B), (C), (D)(1) and (2), (E), (F)(1) and 

(2), (G)(1) and (2), (H), (I)(1) and (2), 

(J)(1) and (2), (K), (L), (M)(1), and (N) is 

disapproved; and 

(v) The remaining portions are 

approved. 

(5) The regional haze long term 

strategy under 40 CFR 51.308(d)(3) is 

partially approved and partially 

disapproved. 

(6) The reasonable progress goals are 

disapproved. 

(b) Interstate Transport. The portion 

of the SIP pertaining to adequate 

provisions to prohibit emissions from 

interfering with measures required in 

another state to protect visibility, 

submitted on March 28, 2008, and 

supplemented on September 27, 2011, is 

partially approved and partially 

disapproved. 

(1) The Arkansas Regional Haze Rule, 

(APCEC Regulation 19, Chapter 15), is 

partially approved and partially 

disapproved such that: 

(i) The requirement under Reg. 

19.104(B) for BART installation and 

operation as expeditiously as 

practicable, but no later than 5 years 

after EPA approval of the Arkansas 

Regional Haze State Implementation 

Plan is partially approved and partially 

disapproved, such that the partial 

approval is for the BART determinations 

we are approving and the partial 

disapproval is for the BART 

determinations we are disapproving; 

(ii) The requirement under Reg. 

19.1504(B) for BART installation and 

operation no later than 6 years after the 

effective date of the State regulation is 

disapproved; 

(iii) Reg. 19.1505 (A)(1) and (2), (B), 

(C), (D)(1) and (2), (E), (F)(1) and (2), 

(G)(1) and (2), (H), (I)(1) and (2), (J)(1) 

and (2), (K), (L), (M)(1), and (N) are 

disapproved; 

(iv) The Reg. 19.1506 requirement to 

demonstrate compliance with the BART 

limits listed in Reg. 19.1505 (A)(1) and 

(2), (B), (C), (D)(1) and (2), (E), (F)(1) and 

(2), (G)(1) and (2), (H), (I)(1) and (2), 

(J)(1) and (2), (K), (L), (M)(1), and (N) is 

disapproved; and 

(v) The remaining portions are 

approved. 

[FR Doc. 2012–4493 Filed 3–9–12; 8:45 am] 

BILLING CODE 6560–50–P 


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