RECElVEU -- &;'EL 

AIR PLANNING SEC. 

08SEP23 PW l: 26 

STATE OF ARKANSAS 

MIKE BEEHI: 

(;OVFRNOR 

July 29,2008 

Richard Greene, Regional Administrator 

United States Environmental Protection Agency- Region 6 

1445 Ross Avenue, Suite 1200 

Mail Code 6RA 

Dallas, TX 75202-2733 

Dear Mr. Greene: 

The State of Arkansas is hereby submitting a State Implementation Plan (SIR$ to? 

address requirements for regional haze visibility protection in mandatory federal Clm I 

areas. This SIP contains the necessary measures to ensure that the tate of ~rkanss is

working toward the national goal for visibility contained in 42 U. C .C. 7491-Visibility 

protection for federal Class I areas. It fulfills requirements under 40 C.F.R. Part 51, 

Requirements for Preparation, Adoption, and Submittal of Implementation Plans, Subpart 

P- Protection of Visibility. 

The Clean Air Act (CAA) and the United States Environmental Protection 

Agency (EPA) regulations require states to submit SIPs to make "reasonable progress" in 

reducing visibility impairment in federal Class I areas resulting from anthropogenic 

pollution. The CAA, 169A(a)(l), "declares as a national goal the prevention of any 

future, and the remedying of any existing, impairment of visibility in mandatory federal 

Class I areas, where impairment results from man-made air pollution." Class I areas are 

national parks, containing more than 6,000 acres, and wilderness areas, containing more 

than 5,000 acres, which Congress has recognized as significant sites. Arkansas has two 

such areas: the Upper Buffalo Wilderness Area in the Ozark National Forest and the 

Caney Creek Wilderness Area in the Ouachita National Forest. 

The Regional Haze Rule focuses on older emission sources that have not been 

regulated under other provisions of the Clean Air Act. Such older sources that could 

contribute to visibility impairment in Class I areas may be required to install Best 

Available Retrofit Technology (BART). Regional Haze SIPs must contain such emission 

limits, schedules of compliance, and other measures as may be necessary to make 

reasonable progress toward meeting the national goal, including requiring installation, 

operation, and maintenance of BART, as determined by the State on certain existing 

stationary sources. 
The EPA Regional Haze Rule strongly encourages states to work together in 

regional partnerships to reduce haze. As a member of the Central Regional Air Planning 

Association (CENRAP), Arkansas has worked closely with Kansas, Louisiana, Iowa, 

Missouri, Nebraska, Minnesota, Oklahoma, and Texas, as well as with federal agencies, 

tribal areas, and other interested parties to improve air quality in our region and the 

country. 

The State of Arkansas hereby submits to the EPA that it has met the requirements 

for regional haze visibility protection in mandatory federal Class I areas under 40 C.F.R. 

551.308. We are enclosing two hard copies and one electronic copy of the State 

Implementation Plan for your review. 

We look forward to your prompt review of this SIP submission. If you have any 

questions, please contact Mike Bates, Air Division Chief of the Arkansas Department of 

Environmental Quality, at 5301 Northshore Drive, North Little Rock, AR 7221 8-53 17, 

or by phone at (501) 682-0750. Thank you for your attention to this matter. 

Sincerely, 

ike Beebe 

cc: Mike Bates, Chief - Air Division, Arkansas Department of Environmental Quality 

Enclosure 
Arkansas Regional Haze SIP 

 

Arkansas Department of Environmental Quality 

State of Arkansas 

Regional Haze Rule 

State Implementation Plan 

Air Division 

Planning and Air Quality Analysis Branch 

5301 Northshore Drive 

North Little Rock, Arkansas 72218-5317 

A Member of Central Regional Air Planning Association 

(CENRAP) 

September 09,2008 
Table of Contents 

i Submittal letter – Governor Approval 

1. Background and Overview of the Federal Regional Haze Regulation 7

2. General Planning Provisions 11

3. Regional Planning 12

4. State/Tribe and Federal Land Manager Coordination 14

5. Assessment of Baseline, Current Conditions and Estimate of Natural Conditions 15

6. Monitoring Strategy 21

7. Emissions Inventory 24

8. Modeling Assessment 32

9. Best Available Retrofit Technology 43

10 Reasonable Progress Goals 58

11. Long Term Strategy to Reach Reasonable Progress Goals 68

12. Comprehensive Periodic Implementation Plan Revisions 76

13. Determination of the Adequacy of the Existing Plan 77

Guidance Documents 78

2
List of Tables

Table 3.1 CENRAP Geographical Area 12

Table 5.1 Visibility Metrics for the Class I Areas in Arkansas 19

Table 7.1 2002 Emissions Inventory Summary 24

Table 7.2 2018 Emissions Inventory Summary 27

Table 8.1 Ambient Data Used in Model Performance Evaluation 36

Table 9.1 Facilities With BART-Eligible Units in the State of Arkansas 45

Table 9.2 Subject-to-BART Sources in the State of Arkansas 47

Table 9.3a BART-Level Emissions Reductions from the 2002 Baseline, Sulfur 

Dioxide (SO2) 52

Table 9.3b BART-Level Emissions Reductions from the 2002 Baseline, 

Oxides of Nitrogen (NOx) 53

Table 9.3c BART-Level Emissions Reductions from the 2002 Baseline, 

Particulate Matter 10 micrometers (PM10) 54

Table 9.3d BART-Level Emissions Reductions from the 2002 Baseline, 

Particulate Matter 2.5 micrometers (PM2.5) 54

Table 9.4a American Electric Power Control Results 55

Table 9.4b Arkansas Electric Coop – Carl E. Bailey Control Results 55

Table 9.4c BART Arkansas Electric Coop – McClellan Control Results 55

Table 9.4d Domtar Control Results 56

Table 9.4e Entergy – Lake Catherine Natural Gas Control Results 56

Table 9.4f Entergy – Lake Catherine Fuel Oil Control Results 56

Table 9.4g Entergy – White Bluff Control Results 56

Table 10.1 Uniform Rate of Progress for Arkansas Class I Areas 59

3
Table 10.2 Reasonable Progress Goals for Arkansas Class I Areas 63

List of Figures 

Figure 1.1 Regional Planning Organizations 8

Figure 1.2 Mandatory Federal Class I Areas 9

Figure 3.1 CENRAP Geographical Areas of Regional Planning Organizations 12

Figure 5.1 Determination of Natural Background 16

Figure 6.1 CENRAP IMPROVE and IMPROVE Protocol Sites 22

Figure 6.2 Class I Areas in Arkansas 23

Figure 7.1 2002/2018 Arkansas Emission Summary Comparison Excluding 

Biogenics 30

Figure 7.2 2002/2018 Arkansas Emission Summary Comparison Including

Biogenics 31

Figure 8.1 Modeling Domain Used for CENRAP 2002 Modeling 35

Figure 8.2 Caney Creek 2002 Daily Extinction Model Performance 39

Figure 8.3 Upper Buffalo 2002 Daily Extinction Model Performance 40

Figure 8.4 Comparison of RPO Visibility Projections 42

Figure 9.1 Map Showing Arkansas’s Bart-Eligible Sources 44

Figure 9.2 Map Showing Arkansas’s Subject-to-Bart Sources 49

Figure 10.1 Uniform Rate of Progress for Caney Creek’s 20% Worst Days 60

Figure 10.2 Uniform Rate of Progress for Caney Creek’s 20% Best Days 61

Figure 10.3 Uniform Rate of Progress for Upper Buffalo’s 20% Worst Days 63

Figure 10.4 Uniform Rate of Progress for Upper Buffalo’s 20% Best Days 64

4
Figure 10.5 Uniform Rate of Progress and Reasonable Progress Goal for Caney Creek’s 20% 

Worst Days 65

Figure 10.6 Uniform Rate of Progress and Reasonable Progress Goal for Caney Creek’s 20% 

Best Days 66

List of Appendices 

Appendices are listed at the end of each chapter. 

5
This page intentionally left blank. 

6
1. Background and Overview of the Federal Regional Haze Regulation 

1.1. General Background / History of Federal Regional Haze Rule

In amendments to the Clean Air Act (CAA) in 1977, Congress added Section 169 (42 U.S.C. 

7491) setting forth the following national visibility goal of restoring pristine conditions in 

national parks and wilderness areas: 

“Congress hereby declares as a national goal the prevention of any future, and the 

remedying of any existing, impairment of visibility in mandatory Class I Federal 

areas which impairment results from man-made air pollution.” 

Over the following years modest steps were taken to address the visibility problems in Class I 

areas. The control measures taken mainly addressed “Plume Blight” from specific pollution 

sources, and did little to address regional haze issues in the Eastern United States. Plume blight 

is the visual impairment of air quality that manifests itself as a coherent plume. This results from 

specific sources, such as a power plant smoke stack, emitting pollutants into a stable atmosphere. 

The pollutants are then transported in some direction with little or no vertical mixing. 

When the CAA was amended in 1990, Congress added Section 169B (42 U.S.C. 7492), 

authorizing further research and regular assessments of the progress made so far. In 1993, the 

National Academy of Sciences concluded that “current scientific knowledge is adequate and 

control technologies are available for taking regulatory action to improve and protect visibility.” 

In addition to authorizing creation of visibility transport commissions and setting forth their 

duties, Section 169B(f) of the CAA specifically mandated creation of the Grand Canyon 

Visibility Transport Commission (GCVTC) to make recommendations to the U.S. 

Environmental Protection Agency (EPA) for the region affecting the visibility of the Grand 

Canyon National Park. In June 1996, following four years of research and policy development, 

the GCVTC submitted its report to EPA. This report, as well as the many research reports 

prepared by the Commission, contributed invaluable information to EPA in its development of 

the federal regional haze rule. 

EPA’s Regional Haze Rule was adopted July 1, 1999, and went into effect on August 30, 1999, 

see Appendix 1.1 Regional Haze Regulations –Final Rule. The Regional Haze Rule aimed at 

achieving national visibility goals by 2064. This rulemaking addressed the combined visibility 

effects of various pollution sources over a wide geographic region. EPA concluded that this 

meant that many states – even those without Class I Areas – would be required to participate in 

haze reduction efforts. EPA designated five Regional Planning Organizations (RPOs) to assist 

with the coordination and cooperation needed to address the visibility issues that states in the 

five regions share or have in common. Those states that make up the midsection of the 

contiguous United States were designated as the Central Regional Air Planning Association 

(CENRAP). Figure 1.1 is a map depicting the five RPO regions. 

7
Fig. 1.1 – Regional Planning Organizations 

On May 24, 2002 the US Court of Appeals, DC District Court ruled on the challenge brought by 

the American Corn Growers Association against EPA’s Regional Haze Rule of 1999. The Court 

remanded to EPA the Best Available Retrofit Technology (BART) provisions of the rule, and 

denied industry’s challenge to the haze rule goals of natural visibility and no degradation 

requirements. On July 6, 2005, EPA issued a revised BART rule. 

The federal requirements for visibility protection are contained in 40 CFR Chapter 51 Subpart P 

– Visibility Protection. The regional haze program requirements are located at 40 CFR 51.308. 

Arkansas submitted a Part I Visibility Plan on March 25, 1985 that was subsequently approved 

by EPA. The approved SIP meets the currently applicable requirements of 40 CFR § 51.302 and 

51.306. 

To facilitate the review of this State Implementation Plan (SIP) by the Environmental Protection 

Agency (EPA), Federal Land Managers (FLM), stakeholders and the public, ADEQ has prepared 

a cross-referenced “Guide to Locating Section 308 Requirements” that is included as Appendix 

1.2 herein. Appendix 1.2 is based on a checklist that was prepared by EPA for its use in review 

of regional haze SIP submittals that includes references and citations for specific Section 51.308 

requirements. ADEQ updated this checklist by inserting references to locations where these 

requirements are address in this SIP. 

1.2 Identification of Class I Areas

In accordance with the requirements of 40 CFR 51.308, CENRAP and ADEQ have conducted 

assessments of emissions and modeled visibility impacts on a regional scale. These assessments, 

further described herein, indicate that various emissions sources located within the State of 

8
Arkansas are likely to cause, or contribute to, regional haze in Class I Areas located both within 

and outside of the boundaries of the State. 

The State of Arkansas has two federal Class I areas within its borders. ADEQ has determined 

that sources located in Arkansas also contribute to regional haze in two additional Class I Areas 

that are located in the State of Missouri. Both of Arkansas’s Class I Areas are designated as 

federally protected wilderness areas for which the United States Department of Agriculture 

(USDA) Forest Service is the FLM. 

In Arkansas, mandatory Class I Federal areas include the 14,460 acre Caney Creek 

Wilderness in Ouachita National Forest at Polk County (CACR) and the 11,801 acre Upper 

Buffalo Wilderness in the Ozark National Forest at Newton County (UPBU). The Upper Buffalo 

Class I Area includes the original wilderness area and the additions to it, but does not include the 

Buffalo National River. 

Potentially affected areas in other states are the two Class I areas in Missouri. These are the 

12,315 acre Hercules Glades Wilderness in the Mark Twain National Forest, located in Taney 

County Missouri (HEGL), approximately 25 miles (40 km) north of Boone County Arkansas; 

and the 8,000 acre Mingo National Wildlife Refuge located in Wayne and Stoddard Counties 

(MING), approximately 30 miles (48 km) north of Clay County, Arkansas. The respective FLMs 

are the USDA Forest Service and the U.S. Fish and Wildlife Service under the U.S. Department 

of Interior. Figure 1.2 depicts the mandatory federal Class I areas throughout the country. 

The emission reductions achieved through implementation of this SIP and other federal, state and 

local measures will result in visibility improvements at Class I areas both within, and outside of, 

the State of Arkansas. These measures will also improve visibility throughout the region. 

Fig. 1.2 – Mandatory Federal Class I Areas 

9
List of Chapter 1 Appendices

1.1 Regional Haze Regulations –Final Rule 

1.2 Guide to Locating Section 308 Requirements

10
2. General Planning Provisions

Pursuant to the requirements of 51.308(a) and (b), Arkansas submits this SIP submission as 

adopted to meet the requirements of EPA’s Regional Haze Rules that were adopted to comply 

with requirements set forth in the CAA. Elements of this plan address the core requirements 

pursuant to CFR 40 51.308(d) and the Best Available Retrofit Technology (BART) components 

of 40 CFR 51.308(e). In addition, this SIP addresses Regional Planning, State and FLMs 

coordination, and contains a commitment to provide plan revisions and adequacy determinations. 

Arkansas has adopted this SIP in accordance with State laws and rules. Arkansas has the 

authority to adopt the SIP in accordance with local laws and rules, see Appendix 2.1(a). 

As required in Section 2.1(f) of Appendix V to 40 CFR Part 51, Arkansas provided public notice 

of the opportunity to comment on the SIP on June 7, 2008 in a statewide newspaper, the 

Arkansas Democrat Gazette. Included in the notice to the public was announcement that a public 

hearing had been scheduled for on July 7, 2008. A copy of the draft Regional Haze SIP was 

made available at the ADEQ Headquarters, Public Records Center, Room 127, 5301 Northshore 

Drive, North Little Rock, Arkansas 72218. 

Arkansas provided the FLMs a draft copy of the Regional Haze SIP and solicited comments 

comment on the draft SIP on February 22, 2008, see Appendix 2.1(b). 

Arkansas held public hearings regarding the SIP on July 7, 2008. Public comments, inclusive of 

those made by the FLMS are addressed and are summarized in Appendix 2.1c. A responsive 

summary of all comments is provided in the final SIP document Appendix 2.1. 

List of Chapter 2 Appendices

2.1 Summary of (a) legal authority; (b) public participation process; and, (c) public 

comments and responses (inclusive of FLMS comments and responses). 

11
3. Regional Planning 

In 1999, EPA and affected States/Tribes agreed to create five RPOs to facilitate interagency 

coordination on Regional Haze SIPs. The State of Arkansas is a member of the Central Regional 

Air Planning Association (CENRAP) RPO. Members of CENRAP are in the geographical areas 

listed in Table 3.1. Figure 3.1 shows a map of all five regional planning organizations. 

Table 3.1 CENRAP Geographical Area* 

Arkansas Iowa 

Kansas Louisiana 

Minnesota Missouri 

Nebraska Oklahoma 

Texas 

*Includes both state and tribal areas 

Figure 3.1 - Geographical Areas of Regional Planning Organizations

12
The governing body of CENRAP is the Policy Oversight Group (POG). The POG is made up of 

eighteen (18) voting members representing the states and tribes within the CENRAP region and 

non-voting members representing local agencies, the EPA, the Fish and Wildlife Service, Forest 

Service, and National Park Service. The POG facilitates communication with FLMs, 

stakeholders, the public, and with CENRAP staff. 

Since its inception, CENRAP has established an active committee structure to address both 

technical and non-technical issues related to regional haze. The work of CENRAP is 

accomplished through five standing workgroups: Data Analysis and Monitoring; Emission 

Inventory; Modeling; Communications; and Implementation and Control Strategies. 

Participation in workgroups is open to all interested parties. Ad hoc workgroups may be formed 

by the POG to address specific issues. Ultimately, policy decisions are made by the CENRAP 

POG. 

CENRAP has adopted the approach that the Regional Haze Rule requires the “States to 

establish goals and emission reduction strategies for improving visibility in all 156 mandatory 

Class I parks and wilderness areas.” The rule also encouraged states and tribes to work together 

in regional partnerships. 

This SIP utilizes data analysis, modeling results and other technical support documents prepared 

for CENRAP members. By coordinating with CENRAP and other RPOs, the State of Arkansas 

has worked to ensure that its long-term strategy and BART determinations provide sufficient 

reductions to mitigate visibility impacts on affected Class I areas. Data analyses, modeling 

results and other technical support documents are provided to CENRAP members through either 

the CENRAP website (cenrap.org) or through a protocol (ftp) that allows users to copy files 

between their local system and the CENRAP network. 

List of Chapter 3 Appendices

There are no Appendices in Chapter 3. 

13
14

4. Arkansas and Federal Land Manager Coordination 

The 40 CFR 51.308(i) require coordination between the State of Arkansas and the Federal Land 

Managers (FLMs). FLMs are an integral part of CENRAP’s POG and the membership on 

standing committees. FLMs have contributed to the development of technical and non technical 

work as a result of that participation. In addition, opportunities have been provided by CENRAP 

for FLMs to review and comment on each of the technical documents developed by CENRAP 

and included in this SIP. The Arkansas Department of Environmental Quality (ADEQ) has 

provided agency contacts to the FLMs as required. In development of this plan, the FLMs were 

consulted in accordance with the provisions of 40 CFR 51.308(i)(2). 

ADEQ provided FLMs an opportunity for consultation, in person and at least 60 days prior to 

holding any public hearing on an implementation plan or plan revision. The FLMs comments can 

be found in Appendix 2.1(c). 

During the consultation process, the FLMs reviewed the SIP to evaluate: 

• Assessment of the impairment of visibility in any Class I areas 

• Recommendations on the development of reasonable progress goals 

• Recommendations on the development and implementation of strategies to address 

visibility impairment. 

ADEQ sent the draft SIP to the FLMs on February 22, 2008. ADEQ notified the FLMs of public 

hearings held on July 7, 2008. ADEQ considered/incorporated the FLMs comments on the SIP 

draft as noted in Appendix 2.1(c). 

ADEQ will continue to coordinate and consult with the FLMs during the development of future 

progress reports and plan revisions, as well as during the implementation of programs having the 

potential to contribute to visibility impairment in the mandatory Class I areas. The FLMs must 

be consulted in the following instances: 

• Development and review of implementation plan revisions 

• Review of 5-year progress reports 

• Development and implementation of other programs that may contribute to impairment 

of visibility in Class I areas. 

Arkansas has consulted in person with FLMs during CENRAP meetings, and commits to 

continued consultation with them during the implementation of other programs having the 

potential to contribute to visibility impairment in the mandatory Class I areas. 

List of Chapter 4 Appendices

4.1 Updated ADEQ Contact for FLMs 
15

5. Assessment of Baseline and Current Conditions and Estimate of Natural Conditions in 

Class I Areas 

The goal of the Regional Haze Rule is to restore natural visibility conditions to the 156 Class I 

areas identified in the 1977 Clean Air Act Amendments. Sec. 51.301(q) defines natural 

conditions: “Natural conditions includes naturally occurring phenomena that reduce visibility as 

measured in terms of light extinction, visual range, contrast, or coloration.” The Regional Haze 

SIPs must contain measures that make “reasonable progress” toward this goal by reducing 

anthropogenic emissions that cause haze. For each Class I area, there are three metrics of 

visibility that are part of the determination of reasonable progress: 

1) baseline conditions 

2) natural conditions 

3) current conditions 

Each of the three metrics includes the concentration data of the visibility pollutants as different 

terms in the light extinction algorithm, with respective extinction coefficients and relative 

humidity factors. Total light extinction when converted to deciviews (dv) is calculated for the 

average of the 20 percent best and 20 percent worst visibility days. 

“Baseline” visibility is the starting point for the improvement of visibility conditions. It is the 

average of the Interagency Monitoring of Protected Visual Environments (IMPROVE) 

monitoring data for 2000 through 2004 and can be thought of as “current” visibility conditions 

for this initial period. The comparison of initial baseline conditions to natural visibility 

conditions indicates the amount of improvement necessary to attain natural visibility by 2064. 

Natural visibility is determined by estimating the natural concentrations of visibility pollutants 

and then calculating total light extinction with the light extinction algorithm. (See Figure 5.1 as 

an example.) Each state must estimate natural visibility levels for Class I areas within its borders 

in consultation with FLMs and other states (51.308(d)(2)). “Current conditions” are assessed 

every five years as part of the SIP review where actual progress in reducing visibility impairment 

is compared to the reductions committed to in the SIP. 

Default and refined values for natural visibility conditions

EPA’s “Guidance for Estimating Natural Visibility Conditions Under the Regional Haze 

Program” (Sept 2003) provides states a “default” estimate of natural visibility. The default 

values of concentrations of visibility pollutants are based on a 1990 National Acid Precipitation 

Assessment Program report (Trijonis, J.C. (1990) NAPAP State of Science & Technology, vol. 

III). In the guidance, the United States is divided into “East” and “West” along the western 

boundary of the states one tier west of the Mississippi River. This division divides the CENRAP 

states into “East” which includes Arkansas (AR), Iowa (IA), Louisiana (LA), Minnesota (MN), 

and Missouri (MO) with seven Class I areas, and “West” which includes Kansas (KS), Nebraska 

(NE), Oklahoma (OK), and Texas (TX) with three Class I areas. In the two equations, only 

sulfate and organic carbon have different values, but the calculated deciview difference is 

significant. (See Appendix 5.2 for further discussion of the default equation.) 
16

Figure 5.1 Determination of Natural Background 

In the guidance, EPA also provides that states may use a “refined approach” to estimate the 

values that characterize the natural visibility conditions of the Class I areas. The purpose of 

refinement would be to provide more accurate estimates with changes to the extinction algorithm 

that may include the following: the concentration values; factors to calculate extinction from a 

measured particular species and particle size; the extinction coefficients for certain compounds; 

geographical variation (by altitude) of a fixed value; and/or the addition of visibility pollutants. 

States can choose between the default and refined equations. One equation is used to calculate 

baseline and current conditions of visibility due to haze-causing pollutants and, with natural 

concentrations of the same pollutants the same equation is used to calculate natural visibility. 
17

Equation 1: The old (default) algorithm 

[ ]

[ ]

[ ]

[ ]

[ ]

[ ]

10

6.0

1

10

4

)(3

)(3

+

×+

×+

×+

×+

××+

××≈

Coarse Mass

Fine Soil

Elemental Carbon

Organic Carbon

f RH Nitrate

fb RH Sulfate ext

Equation 2: The new (refined) algorithm: 

Differences from the default are in bold. 

[ ] [ ]

[] [

[ ] [

[ ]

[ ]

[ ]

[ ]

[ ] 0. 3 3 N O p p b

S p e cifi c

)

S it e (R a yl ei g h S c a t t e ri n g

R H S e a S al t ) (

1 . 7 f

2 . 8 S m al l O r g a ni c C a r b o n 6. 1 L a r g e O r g a ni c C a r b o n

R H L a r g e Ni tr a t e ) (

R H S m al l Nitr at e 5. 1 f ) (2. 4 f

R H L a r g e S ulf at e )

The choice between use of the default or the refined equation for calculating the visibility 

metrics for each Class I area is made by the state in which the Class I area is located. According 

to 40 CFR 51.308(d)(2), the state will make the determinations of baseline and natural visibility 

conditions. It is with these calculations and in consultation with other states whose emissions 

affect visibility in that park or wilderness area (40 CFR 51.308(d)(1)(iv)) that the state has 

developed a “reasonable progress goal” for each Class I area. 

]

]

) (

(

R H S m al l S ul f a t e 4. 8 f (

)

2 . 2 f

2

S S

S L

S L

×+

+

×+

×+ ×

×+

×+

×+ ×+

××+ ××+

××≈ + × ×

Coarse Mass

SoilFine

Elemental Carbon

bext

6.0

1

10

 

The refined equation was used by ADEQ to calculate visibility metrics for the purpose of 

developing its reasonable progress goal. Please refer to Appendix 5.2 for the IMPROVE 

Steering Committee’s report on the justification for the use of the “refined” IMPROVE 

algorithm. 

 The IMPROVE Steering Committee recommended to EPA a change to the light extinction 

equation. With this revision, a second set of “refined” numbers is being added to the IMPROVE 

and VIEWS websites for baseline and current condition values for each Class I area. States that 

choose the “corrected” algorithm that incorporate recent visibility research and analysis can also 

adopt new natural conditions values and document the reasonableness of these changes to EPA. 
18

Consultation Regarding the Visibility Metrics

Consultation among states is a requirement that is repeated in the Regional Haze Rule. As part 

of a “long-term strategy” for regional haze, a state whose emissions are “reasonably anticipated” 

to contribute to impairment in other states’ Class I area(s) must consult with those states; 

likewise, the state must consult with any states whose emissions affect its own Class I area(s) (40 

CFR 51.308(d)(3)). 

A chief purpose of the RPO is to provide a means for states to confer on all aspects of the 

regional haze issue, including consultation on reasonable progress goals and long-term strategies 

based on the current (baseline) and natural visibility determinations. (This process is described 

in Chapter 3 “Regional Planning”). CENRAP has provided a forum for the member States and 

Tribes to consult on the determination of baseline and natural visibility conditions in each of the 

Class I areas. 

In addition, states in CENRAP have conferred with neighboring Class I area states outside 

CENRAP, both individually and by way of the states’ RPO. Description of Arkansas’s 

consultation process is located in Chapter 10 Section 3. 

The 40 CFR 51.308(i) requires Class I area states’ coordination with FLMs which includes 

consultation on implementation, the assessment of visibility impairment, and recommendations 

regarding the reasonable progress goal and strategies for improvement. This consultation 

requirement is treated in Chapter 4. 

Through participation in CENRAP and as a state, Arkansas has completed this regulatory 

requirement. Chapter 4 provides details of actions taken to meet this requirement. 

5.1 Baseline Visibility Conditions 

 Caney Creek WA has an established baseline visibility of 11.24 deciviews for the cleanest 20 

percent of the sample days and 26.36 deciviews for the 20 percent worst visibility days. This is 

based on sampling data collected at the IMPROVE monitoring site located on Eagle Mountain, 

Polk County, Arkansas. A three year average (2002 to 2004) was calculated for each value (both 

best and worst) in accordance with 40 CFR 51.308(d)(2). The light extinction and deciview 

visibility values for these worst and best days are based on data and calculations included in 

Appendix 5.1 of this SIP. The summary data with the concentration values, light extinction 

calculations, and deciview values are presented in tables in Appendix 5.1 

Upper Buffalo Wilderness Area (WA) has an established baseline visibility of 11.71 deciviews 

for the cleanest 20 percent of the sample days and 26.27 deciviews for the 20 percent worst 

visibility days. This is based on sampling data collected at the IMPROVE monitoring site 

located in Deer, Newton County, Arkansas. A five year average (2000 to 2004) was calculated 
19

for each value (both best and worst) in accordance with 40 CFR 51.308(d)(2). The light 

extinction and deciview visibility values for these worst and best days are based on data and 

calculations included in Appendix 5.1 of this SIP. The summary data with the concentration 

values, light extinction calculations, and deciview values are presented in tables in Appendix 5.1. 

5.2 Natural Visibility Conditions 

The state of Arkansas has within her boundary two mandatory Class I federal areas (Class I 

area), Upper Buffalo WA and Caney Creek WA which are managed by the United States Forest 

Service. Table 5.2 contains the natural conditions for the 20 percent (%) best days and the 20% 

worst days as well as the baseline visibility conditions for the 20% best and 20% worst days for 

each Class I area in Arkansas. Appendix 5.3 provides calculations and methodologies for 

estimating natural visibility conditions. 

5.1 Visibility Metrics for the Class I Areas in Arkansas

Natural Background Conditions 

Class I Area Average for the 

20% Worst 

Days 

(deciview) 

Average for the 

20% Best Days 

(deciview) 

Average for the 

20% Worst 

Days Bext 

(Mm-1) 

Average for the 

20% Best 

 Days Bext

(Mm-1) 

Caney Creek 11.58 4.23 21.16 4.33 

Upper Buffalo 11.57 4.18 21.54 4.23 

Baseline Visibility Conditions 2000 - 2004 

Class I Area Average for the 

20% Worst 

Days 

(deciview) 

Average for the 

20% Best Days 

(deciview) 

Average for the 

20% Worst 

Days Bext 

(Mm-1) 

Average for the 

20% Best 

 Days Bext

(Mm-1) 

Caney Creek 26.36 11.24 134.1 20.61 

Upper Buffalo 26.27 11.71 131.95 22.19 
20

List of Chapter 5 Appendices

5.1 Revised Algorithm for Estimating Light Extinction from IMPROVE Particle Speciation 

Data 

5.2 Determination of Baseline Visibility Conditions 

5.3 Estimate of Natural Visibility Conditions 
21

6. Monitoring Strategy 

Section 51.308(d)(4) of the federal regional haze rule requires a monitoring strategy for 

measuring, characterizing, and reporting regional haze visibility impairment that is representative 

of all mandatory Class I areas within the State of Arkansas. The monitoring strategy relies upon 

participation in the Interagency Monitoring of Protected Visual Environments (IMPROVE) 

network. 

Current Monitoring Strategy

Upon the creation of CENRAP, the newly formed Monitoring Workgroup identified that there 

were large visibility data voids in Southern Arkansas, Iowa, Kansas, Southern Minnesota, 

Nebraska, and Oklahoma. Only five (5) IMPROVE sites were located in the CENRAP region. 

Between 2000 and 2003, five (5) more IMPROVE sites and 15 IMPROVE Protocol Sites were 

installed (see Figure 6.1). In Arkansas, IMPROVE sites are located at the 14,460 acre Caney 

Creek Wilderness area in the Ouachita National Forest in Polk County, and the 11,801 acre 

Upper Buffalo Wilderness area in the Ozark National Forest in Newton County. The Upper 

Buffalo Class I area includes the original wilderness and the additions to it. It does not include 

the Buffalo National River (see Figure 6.2). In addition to the IMPROVE monitor, the Upper 

Buffalo Wilderness area site also includes a National Parks Service maintained nephelometer, 

and a meteorological monitor. Arkansas commits to meeting the requirements under 40 CFR 

51.308(d)(4)(iv) to report to EPA visibility data for each of the Arkansas Class I areas annually. 

The filter samples from the IMPROVE modules are sent for analysis to the Crocker Nuclear 

Laboratory of the University of California in Davis and the data is posted to the IMPROVE 

website [http://vista.cira.colostate.edu/improve/] and the Visibility Information Exchange 

Websystem (VIEWS) website [http://vista.cira.colostate.edu/views/]. This fulfills Arkansas’s 

reporting requirement of visibility data (electronic) under subsection (iv). Details regarding the 

monitors (location, date of installation etc.) and monitoring data are found in Appendices 6.1, 

and 6.2. 
22

Figure 6.1 CENRAP IMPROVE and IMPROVE Protocol Sites 
23

Figure 6.2 Class I areas in Arkansas 

Future Monitoring Strategy

In order to assess progress in reducing visibility impairment in Class I areas, the existing 

IMPROVE and IMPROVE Protocol sites will be maintained contingent upon continued national 

funding to measure, characterize and report regional haze visibility impairment to satisfy 

requirements of subsection (i). The State will evaluate the monitoring network periodically 

including evaluation technology changes and the need for new monitors. Where economically 

feasible or with national funds, the State anticipates making those changes needed to be able to 

assess whether reasonable progress goals are being achieved in each of Arkansas’s mandatory 

Class I areas. 

Special Monitoring Studies

As funding permits, CENRAP, in cooperation with states and tribes, intends to study impacts of 

ammonia and carbon on visibility impairment in the CENRAP region. Preliminary monitoring 

studies and monitoring data analysis suggests that these two air constituents contribute to a large 

portion of visibility impairment in the CENRAP geographical area. 

List of Chapter 6 Appendices

 

6.1 Monitoring and Data Analysis to Support the Regional Haze Rule 

6.2 CENRAP Regional Haze Monitoring Strategy 
24

7.0 Emission Inventory 

The 40 CFR 51.308(d)(4)(v) requires a statewide emission inventory of pollutants that are 

reasonably anticipated to cause, or contribute, to visibility impairment in any mandatory Class I 

area. As specified in the applicable EPA guidance, the pollutants inventoried by Arkansas 

include volatile organic compounds (VOCs), nitrogen oxides (NOX), fine particulate (PM2.5), 

coarse particulate (PM10), ammonia (NH3), carbon monoxide (CO), and sulfur dioxide (SO2). 

An inventory was developed for the baseline year 2002, and ADEQ will update the emission 

inventory according to the policy issued by the EPA. A summary of those inventory results 

follows; the 2002 emission inventory developed by Environ International Corporation has been 

submitted as Appendix 7.1 A. 

 

Table 7.1 2002 Emissions Inventory Summary 

VOC NOx PM2.5 PM10 NH3 CO SO2 

Point 44,329 72,419 7,837 12,406 1 56,366 92,205

Nonpoint 93,548 27,450 68,000 148,433 152,436 436,525 29,889

Nonroad 

Mobile 

 

54,785 62,472 5,220 5,673 49 272,627 5,490

On-Road 

Mobile 48,599 141,894 3,021 3,784 2,480 669,214 3,902

Biogenics 1,385,666 18,960 136,688 

TOTAL 1,626,927 323,195 84,078 170,296 154,967 1,571,419 131,485

Overview of the 2002 Emission Inventory 

The 2002 point source inventory was completed in-house with Emission Inventory 

Questionnaires (EIQs). We contracted with Environ to prepare our on-road, nonroad, and 

nonpoint sources 2002 emission inventory (see enclosed document in Appendix 7.1 A). We 

accepted the EPA’s biogenic source inventory. The nonpoint source inventory included emitters 

of ozone pollutants (i.e., VOC, NOx and CO) such devices that combust fuel (e.g., wood stoves, 

commercial and industrial boilers), disperse industrial and commercial VOC sources (e.g., dry 

cleaners, degreasing and industrial surfaces coating), gasoline distribution, asphalt paving and 

fires and open burning (e.g., agricultural burning, structural fires wildfires, prescribed burning). 

For some source categories, the methodologies actually used in the Arkansas nonpoint source 

inventory are different than those originally proposed due to newly developed methodologies. 

Also, because some data were not available, alternate sources of data for some source categories 

were used. The industrial fuel combustion categories in the Arkansas nonpoint inventory were 

reconciled with industrial nonpoint fuel data in order to prevent potential double counting of 

emissions. The industrial point source fuel data were obtained from ADEQ’s Emission 

Inventory Questionnaire (ADEQ 2004). The 2002 EIQs were being processed and could not be 

used; The 2001 EIQ were used instead. All EIQ fuel use data were being processed and could 

not be used; The 2001 EIQ were used instead. All EIQ fuel use data were directly input “as is” 

into a spread sheet form the EIQ forms. The only adjustments made were to the EIQ data were 
25

conversions units (i.e., natural gas to 106 ft3

, distillate and residual fuel oil to 103 gallons, and 

coal to tons) and corrections of obvious inconsistencies (e.g., wood combustion reported in units 

of 106

 ft3 for a natural gas boiler was switched to natural gas combustion, etc.). Facilities with 

ambiguous fuel types, quantities or units were omitted from the reconciliation. The 

reconciliation was performed by subtracting state level EIQ industrial nonpoint fuel use from the 

nonpoint inventory’s state level industrial combustion fuel use. Fuel use from utility facilities 

listed in the EIQ was not included in the EIQ fuel use totals. Distillate fuel oil, residual fuel oil, 

natural gas and coal were included in the reconciliation; LPG use was not identified in the EIQ 

fuel use data. As a result of the reconciliation, state level industrial fuel use in the nonpoint 

inventory was adjusted (i.e., distillate fuel oil reduced by 4.3 percent, natural gas reduced by 45.0 

percent and coal reduced by 16.8 percent). For residual fuel oil, the EIQ fuel use data exceeded 

the industrial fuel combustion nonpoint fuel use estimate. Therefore, industrial fuel combustion 

or residual fuel oil in the nonpoint inventory was adjusted to zero. Reconciliation for other area 

source categories (i.e., industrial surface coating or degreasing) was not preformed because data 

were unavailable on the EIQ forms. 

On-road Source Inventory 

The on-road mobile source emissions included emissions from vehicles certified for highway use 

– cars, trucks, and motorcycles. Emissions from these sources were estimated by combining 

EPA emission factors from the MOBILE6 model, expressed in grams per mile (g/mile), with 

vehicle miles traveled (VMT) activity data. For all of the Arkansas counties, county-level 

Highway Performance Monitoring System (HPMS) VMT data were used. The data collected as 

part of the on-road inventory were reviewed prior to use in emission calculations. All modeling 

inputs, data processing and calculation spreadsheets were checked by a technical supervisor. 

Annual average daily HPMS VMT data were provided by the Arkansas Highway and 

Transportation Department (AHTD). These data were reported separately for urban and rural 

areas and within those categories, by county and HPMS facility class. The AHTD provided data 

for 2007 and 2010 and these were exponentially extrapolated back to 2002. To arrive at monthspecific estimates, the annual average was adjusted using seasonal factors derived based upon 

data provided by AHTD. Finally, to obtain weekday VMT (for the summer and winter reporting 

requirements) the monthly values were corrected using Texas statewide average weekday/annual 

average daily factors: there were no default factors from EPA and these were considered to be 

the best, given the limited data available from only a few states. For each county, MOBILE6 

emission was used in combination with the VMT data to estimate emissions by roadway type 

and vehicle type and vehicle class. National average speeds derived from HMPS data for each 

facility class were utilized. Monthly emissions were first estimated from which annual total, 

summer weekday and winter weekday emissions were derived. 

 

Nonroad Emission Inventory

Nonroad mobile sources encompass a wide variety of equipment types that either move under 

their own power or are capable of being moved from site-to-site. More specifically, these 

sources, which are not licensed or certified as highway vehicles, are defined as those that move 
26

or are moved within a 12-month period and are convered under the EPA’s emissions regulations 

as nonroad mobile sources. Where feasible and appropriate, local activity data for specific 

source categories were gathered and used to develop the inventory. 

US EPA’s draft NONROAD2002 model (June 2003 version) was used to estimate emissions for 

most nonroad sources. The NONROAD model estimates emissions from non-road equipment in 

the following categories: 

▪ Agricultural equipment, such as tractors, combines and balers 

▪ Airport ground support, such as terminal tractors 

▪ Construction equipment, such as graders and back hoes 

▪ Industrial and commercial equipment, such as fork lifts and sweepers 

▪ Residential and commercial lawn and garden equipment, such as leaf and snow blowers 

▪ Logging equipment, such as shredders and large chain saws 

▪ Recreational equipment, such as off-road motorbikes and snowmobiles and 

▪ Recreational marine vessels, such as power boats 

Aircraft, commercial marine and locomotive emissions were also included in the non-road 

inventory, but these sources were estimated separately since they were not included in the 

NONROAD model. General EPA methodologies were followed to estimate emissions for these 

three categories. For all source categories, annual average emissions have been estimated in tons 

per year and ozone season and winter season daily emissions are estimated in tons per day. All 

data collected as part of nonroad sources emission inventory were thoroughly reviewed to ensure 

that they were the most appropriate and up-to-date emission factors available. 

Point Source Inventory

ADEQ is responsible for compiling the point source inventory. The Air Division Emission 

Inventories and Data Management Section is accountable for identifying point sources meeting 

the threshold criteria, collecting facility emissions data, processing, managing data, compilation 

and displaying the results. Emissions data provided by the facilities are estimates of actual 

emissions for the facility during the previous year. Estimations methodologies are required to 

follow state and federal guidelines. Point Sources are large, stationary, emissions sources that 

release pollutants into the atmosphere. According to the Consolidated Emissions Reporting Rule 

(CERR), States are required to report data for larger point sources, or Type A point sources, on 

an annual basis, starting with 2001 inventory. Type B sources refer to all point sources, 
27

including Type A sources. The reporting frequency for Type B sources has been established as 

once every 3 years, starting with the 2002 base year inventory. 

Actual measurement with continuous emissions monitoring systems (CEMS) is the desired 

method of calculation emissions from a point source. In lieu of CEMS data, emissions may be 

calculated using other stack test data, material balance or emissions factors from AP-42 or 

approved engineering journals. Since the data are used for modeling and other purposes, data 

elements include parameters and coordinates, control devices and efficiencies, actual emissions, 

emission factors, process codes and parameters. All data are processed into the i-STEPS 

database which automatically applies minimum quality assurance and quality control checks. 

Further, the data is processed for inaccuracies those that cannot be readily resolved are referred 

back to the facility for clarification/correction. 

Following the submission of our 2002 Emission Inventory to the CDX, additional quality 

assurance, and revision of the data was completed through CENRAP. E. H. Pechan & 

Associates (Pechan) was contracted to QC the data and fill in the gaps where needed. Pechan 

would call us with errors they detected in the 2002 inventory and we would make corrections 

over the phone and sometimes via email. Pechan’s work is included in (Appendix 7.1 B and C): 

The Consolidation of Emissions Inventories (April 28, 2005) and Refinement of CENRAP’s 2002 

Emissions Inventories (August 31, 2005). 

The majority of the nonroad mobile inventory was developed by Sonoma Technology under a 

contract with CENRAP. The methods and data used by Sonoma are described in the report 

(Appendix 7.1 D) Emission Inventory Development for Mobile Sources and Agricultural Dust 

Sources for the Central States (October 28, 2004). 

Table 7.2 2018 Emissions Inventory Summary 

VOC NOx PM2.5 PM10 NH3 CO SO2 

Point 55,603 71,107 13,775 19,799 2,575 75,708 106,461

Nonpoint 107,387 31,531 69,585 148,592 201,722 448,760 31,169

Nonroad 

Mobile 31,475 34,305 3,387 3,678 49 293,734 211

On-Road 

Mobile 19,924 33,640 949 949 3,412 367,152 443

Biogenics 1,385,666 18,960 136,688 

TOTAL 1,600,055 189,542 87,695 173,019 207,758 1,322,043 138,283

Overview of the 2018 Emission Inventory 

The 2002 emissions were grown to 2018 by using growth and control factors derived from the 

EGAS6, MOBILE6, and NONROAD models. The Integrated Planning Model (IPM) was used 

to forecast 2018 electric generating unit (EGU) emissions. Table 7.2 provides a summary of the 

2018 BaseG emissions inventory. The summary data provided in Table 7.2 was compiled 

through a contract with E. H. Pechan. 
28

The 2018 point source emission inventory was prepared by CENRAP. For the non-EGUs, the 

2002 emission were projected by applying growth and control factors using the SMOKE model. 

The growth and control factors were prepared by Pechan and are documented in the report 

(Appendix 7.2 E): Development of Growth and Control Inputs for CENRAP 2018 Emissions 

Draft Technical Support Document (May 2005). The control factors for non-EGU point sources 

account for Maximum Achievable Control Technology (MACT) standards and the NOx SIP Call 

for industrial boilers. 

The Integrated Planning Model (IPM) version 2.1.9 model out put for 2018 was used for 2018 

EGU point source emissions. The SMOKE IDA formatted version of the 2018 Integrated 

Planning Model (IPM) was prepared by Pechan for CENRAP. See the Pechan report, 

Refinement of CENRAP’s 2002 Emissions Inventories (August 31, 2005), in Appendix 7.1 C for 

additional information. The IPM conducted by ICF specifically address the emission reductions 

to be realized through implementation of CAIR assuming all states participated in the EPA’s 

trading program, Acid Rain Program (Title IV-Phases I and II), NOx SIP Call, State and local 

regulations, while incorporating unit-level updates provided by power company stakeholders. 

The University of California-Riverside (UCR) ran the smoke Model for the 2018 point sources. 

The edited IPM file for EGUs was processed in SMOKE without adjustments. The growth and 

control factors for non-EGUs were applied using the SMOKE model. The technical support 

document in Appendix 8.1 describes UCR’s work on the 2018 point source inventory. 

To prepare the nonpoint inventories for modeling, UCR made several modifications to the IDA 

files by removing selected sources either to model them as separate source categories or to omit 

them from simulations completely. Fugitive and road dust sources were extracted from all 

stationary nonpoint inventories and adjusted by transport factors following Methodology to 

Estimate the Transportable Fraction (TF) of Fugitive Dust Emissions for Regional and Urban 

Scale Air Quality Analyses (Pace 2005). 

The 2018 nonpoint source emissions inventory was based on data provided by CENRAP states. 

Nonpoint source growth and control factors were prepared by Pechan and are documented in the 

following report in Appendix 7.2 E: Development of Growth and Control and Control Inputs for 

CENRAP 2018 Emission Draft Technical Support Document (May 2005). The control factors 

reflect New Source Performance Standards (NSPS) for residential wood combustion and Stage I 

vapor recovery controls, including onboard vapor recovery. UCR ran the SMOKE model for the 

2018 area source emissions. The growth and control factors for nonpoint sources were applied 

within SMOKE. The technical support document in Appendix 8.1describes UCR’s work on the 

2018 nonpoint inventory. Windblown dust from non-agricultural land use categories and fire 

emissions were held constant from 2002 to 2018. 

The 2018 nonroad mobile inventory was based on inputs from CENRAP states. Growth and 

control factors for locomotives, aircraft, and commercial marine vessels were prepared by 

Pechan. The control factors accounted for federal standards for commercial marine vessels and 

locomotives. For the remaining nonroad mobile categories, Pechan ran the EPA’s 
29

NONROAD2004 model for 2018. EPA’s NONROAD2004 model accounts for growth in 

equipment population and incorporates the effects of most final federal standards, including the 

Tier 4 diesel engine standards and the exhaust emission standards for large spark-ignition 

engines, diesel marine, and land-based recreational engines. Pechan’s methods are described in 

detail in Appendix 7.2 E: Development of Growth and Control inputs for CENRAP 2018 

Emissions Draft Technical Support Document (May 2005). UCR applied the growth and control 

factors to NONROAD categories using the SMOKE model. In addition, UCR processed 

NONROAD-model categories in SMOKE without adjustments. The technical support document 

Appendix 8.1 describes UCR’s work on the 2018 nonroad inventory. 

Pechan prepared the VMT and MOBILE inputs for the 2018 on-road mobile source emissions 

inventory. The VMT growth factors and MOBILE6 input files were provided in SMOKE 

format. The MOBILE6 model accounts for motor vehicle controls, including light duty diesel 

engine standards and low-sulfur diesel. The technical support document in Appendix 8.1 

describes UCR’s onroad mobile emissions inventory processing. 

UCR generated biogenic emissions by running the BEIS3 model within the SMOKE framework. 

BEIS3 is a system integrated into SMOKE for deriving emissions estimates of biogenic gasphase pollutants from land use information, emissions factors for different plant species, and 

hourly, gridded meteorology data. Biogenic emissions were held constant from 2002 to 2018. 

The technical support document in Appendix 8.1 describes the development of the biogenic 

emission inventory. 

The increase in SO2 from 127,290 in 2002 to 138,284 in 2018 is attributed to growth in 

Electrical Generating Units (EGU) use in Arkansas. We anticipate additional coal fired plants 

being built between 2002 and 2018. See figures 7.1 and 7.2 for a comparison of the 2002 and 

2018 inventory by source category. 

The point source inventories will be updated on an annual basis and the nonpoint, on-road, 

nonroad mobile inventories will be updated every three years according to the Consolidated 

Emissions Reporting Rule. 
30

2002/2018 Arkansas Emission Summary Comparison (Excluding Biogenics)

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

20022018200220182002201820022018200220182002201820022018

Tons Per Year

On-Road

Off-Road

Area

Point

 VOC NOx PM 2.5 PM 10 NH3 CO SO2 

Figure 7.1. 2002/2018 Arkansas Emission Summary Comparison (Excluding Biogenics) 
31

2002/2018 Arkansas Emission Summary Comparison (Including Biogenics)

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

1800000

20022018200220182002201820022018200220182002201820022018

Tons Per Year

Biogenics

On-Road

Off-Road

Area

Point

 VOC NOx PM 2.5 PM 10 NH3 CO SO2 

Figure 7.2. 2002/2018 Arkansas Emission Summary Comparison (Including Biogenics) 

List of Chapter 7 Appendices

7.1 Statewide/Tribal 2002 Emissions Inventory – Parts A-D 

7.2 2002 Emissions Inventory Short Summary (Chapter 8 Appendix 8.1 TSD includes all 

CENRAP contractor work) 
32

8. Modeling Assessment 

The 40 CFR Part 51, Appendix W provides modeling guidelines for conducting regional-scale 

modeling for particulate matter and visibility. The U.S. EPA recommends the use of one of the 

three following models to simulate pollutants impairing visibility: Community Multiscale Air

Quality (CMAQ), the Comprehensive Air quality Model (CAMx), and Regional Modeling 

System for Aerosols and Deposition (REMSAD). CENRAP contractors performed regional 

modeling using CMAQ and CAMx. 

The CMAQ model is an Eulerian model that simulates the atmospheric and surface processes 

affecting the transport, transformation and deposition of air pollutants and their precursors. A 

Eulerian model computes the numerical solution of partial differential equations of plumes on a 

fixed grid; other models may lose accuracy or need regridding as the plumes expand. 

CAMx is a computer modeling system for the integrated assessment of photochemical and 

particulate air pollution. CAMx incorporates all of the technical attributes demanded of stateof-the-art photochemical grid models, including two-way grid nesting, a subgrid-scale Plume-inGrid module to treat the early dispersion and chemistry of point source NOx plumes, and a fast 

chemistry solver. 

Particulate Matter (PM) Modeling: CAMx Mechanism 4 (M4) provides "1-atmosphere" 

modeling for fine and coarse PM and ozone. Aqueous phase chemistry is modeled using the 

RADM mechanism. Inorganic sulfate/nitrate/ammonium chemistry is modeled with 

ISORROPIA. ISORROPIA is a model that calculates the composition and phase state of an 

ammonia-sulfate-nitrate-chloride-sodium-water inorganic aerosol in thermodynamic equilibrium 

with gas phase precursors. Secondary organic aerosols are modeled using a semi-volatile scheme 

called Simple Object Access Protocol (SOAP). Wet and dry deposition processes are included 

for gasses and particles. Gridded deposition information is output along with the concentrations. 

In the July 1, 1999 publication of the Regional Haze Rule in the Federal Register, EPA defined 

the uses of regional modeling as follows: 

• Analyses and determination of the extent of emissions reductions needed from individual 

states 

• Analyses and determination of emissions needed to meet the progress goal for the Class I 

area 

• Analyses to support conclusion that the Long-Term Strategy provides for reasonable 

progress 

• Analyses to calculate the resulting degree of visibility improvement that would be 

achieved at each Class I area 

• Analyses to compare visibility improvement between proposed control strategies 
33

8.1 Model Inputs 

8.1.1. Selection of Episodes 

The calendar year 2002 was selected for the base year for CENRAP regional haze 

annual modeling consistent with EPA guidance. The Technical Support 

Document provides additional information on the selection of 2002 as the base 

year for regional haze modeling and is found at Appendix 8.1. 

8.1.2. Selection of Modeling Domain 

CENRAP conducted emissions and air quality modeling on the 36 km national 

RPO domain. This domain consists of a 148 by 112 array of 36 km by 36 km grid 

cells and covers the continental United States, see Figure 8.1. The Technical 

Support Document provides additional information on 

the modeling domain and is found at Appendix 8.1. 

8.1.3 Emission Inventories - The emissions inventory includes VOC, NOX, CO, SO2, 

PM10, PM2.5, and NH3 emissions from all anthropogenic and biogenic sources. 

The emissions inventory information submitted by state, tribal, and local agencies 

to the 2002 NEI formed the basis of the 2002 CENRAP emissions inventory. The 

NEI data was supplemented with non-point source emissions inventories 

developed for CENRAP by Sonoma Technology. These CENRAP-specific 

inventories addressed agricultural and prescribed burning, onroad and offroad 

mobile sources, agricultural tilling and livestock dust, and agricultural ammonia. 

In addition, Pechan assisted CENRAP by quality-assuring the emissions inventory 

and preparing day- and hour-specific emissions for EGUs based on Continuous 

Emissions Monitor (CEM) data for the model performance evaluation. Emissions 

inputs for the air quality model were prepared using the SMOKE emissions 

modeling system. The CENRAP modeling emissions inventory consists of several 

distinct datasets: the 2002 base case for model performance evaluation, 2002 

typical, 2018 base case, and the 2018 control strategy scenario. Its spatial extent is 

the RPO 36 km modeling domain, which covers. The Technical Support 

Document (TSD) provides the methodologies for this process and is found in

Appendix 8.1. Emission inventory information can be found in Chapter 7. 

8.1.3. Meteorology - The Fifth-Generation NCAR / Penn State Mesoscale Model 

(MM5) is the latest in a series that developed from a mesoscale model used by 

Anthes at Penn State in the early 70's that was later documented by Anthes and 

Warner (1978). Since that time, it has undergone many changes designed to 

broaden its usage. These changes include: a multiple-nest capability; 

nonhydrostatic dynamics, which allows the model to be used at a few-kilometer 

scale; multitasking capability on shared- and distributed-memory machines; a 

four-dimensional data-assimilation capability; and more physics options. The 

model (known as MM5) is supported by several auxiliary programs, which are 

referred to collectively as the MM5 modeling system. Since MM5 is a regional 

model, it requires an initial condition as well as a lateral boundary condition to 

run. To produce a lateral boundary condition for a model run, gridded data to 
34

cover the entire time period that the model is integrated is needed The TSD 

provides the methodologies for this process and is found at Appendix 8.1. 

8.2 2002 Model Year 

8.2.1 Model Year Selection 

The calendar year 2002 was selected for CENRAP regional haze annual modeling as described 

in the CENRAP Modeling Protocol prepared at the end of 2004. EPA’s applicable guidance on 

PM2.5/Regional Haze modeling at that time (EPA, 2001) identifies specific goals to consider 

when selecting modeling periods for use in demonstrating reasonable progress in attaining the 

regional haze goals. Due to limited available resources CENRAP was restricted to modeling a 

single Calendar Year (CY). The RHR uses the five-year baseline of 2000-2004 period as the 

starting point for projecting future-year visibility. Thus, the modeling year should be selected 

from this five-year baseline period. The 2002 calendar year, which lies in the middle of the 

2000-2004 Baseline, was selected for the following reasons: 

3⁄4 Based on available information, 2002 appears to be a fairly typical year in terms of 

meteorology for the 5-year Baseline period of 2000-2004; 

3⁄4 2003 and 2004 appeared to be colder and wetter than typical in the eastern US; 

3⁄4 The enhanced IMPROVE and IMPROVE Protocol and Supersites PM monitoring data 

were fully operational by 2002. Much less IMPROVE monitoring data was available 

during 2000-2001, especially in the CENRAP region; 

3⁄4 IMPROVE data for 2003 and 2004 were not yet available at the time the CENRAP 

modeling was initiated; and 

3⁄4 2002 is being used by the other RPOs. 

The CMAQ and CAMx models were operated separately for each of four quarters of the 2002 

year using a ~15 day spin up period (i.e., the models were started approximately 15 days before 

the first day of interest in each quarter in order to limit the influence of the assumed initial 

concentrations, e.g., start June 15 for quarter 3 whose first day of interest is July 1). Boundary 

Conditions (BCs) (i.e., the assumed concentrations along the later edges of the 36 km modeling 

domain, see Figure 8.1) were based on a 2002 simulation by the GEOS-CHEM global 

circulation/chemistry model. GEOS-CHEM is a three-dimensional global chemistry model 

driven by assimilated meteorological observations from the Goddard Earth Observing System 

(GEOS) of the NASA Global Modeling and Assimilation Office. It is applied by research groups 

around the world to a wide range of atmospheric composition problems, including future 

climates and planetary atmospheres using general circulation model meteorology to drive the 

model. Central management and support of the model is provided by the Atmospheric Chemistry 

Modeling Group at Harvard University 
35

-2736 -2304 -1872 -1440 -1008 -576 -144 288 720 1152 1584 2016 2448

-2088

-1872

-1656

-1440

-1224

-1008

-792

-576

-360

-144

72

288

504

720

936

1152

1368

1584

1800

Figure 8.1. National Inter-RPO 36 km modeling domain used for the CENRAP 2002 annual 

SMOKE, CMAQ and CAMx modeling. 

8.2.2 Emissions Input Preparation 

The CENRAP SMOKE emissions modeling was based on an updated 2002 emissions data for 

the U.S. (Pechan, 2005c,e; Reid et al., 2004a,b), 1999 emissions data for Mexico (ERG, 2006), 

and 2000 emissions data for Canada. These data were used to generate a final base 2002 Base G 

Typical (Typ02G) annual emissions database. Numerous iterations of the emissions modeling 

were conducted using interim databases before arriving at the final Base G emission inventories 

(e.g., Morris et al., 2005). The 2018 Base G base case emissions (Base18G) for most source 

categories in the U.S. were based on projections of the 2002 inventory assuming growth and 

control (Pechan, 2005d). 

8.2.3 Meteorological Input Preparation 

The 2002 36 km MM5 meteorological modeling was conducted by the Iowa Department of 

Natural Resources (IDNR) who also performed a preliminary model performance evaluation 

(Johnson, 2004). CENRAP performed an additional MM5 evaluation of the CENRAP 2002 36 
36

km MM5 evaluation that included a comparative evaluation against the final VISTAS 2002 36 

km MM5 and an interim WRAP 2002 36 km simulation (Kemball-Cook et al., 2004). 

8.2.4 Photolysis Rates Model Inputs 

Several chemical reactions in the atmosphere are initiated by the photodissociation of various 

trace gases. To accurately represent the complex chemical transformations in the atmosphere, 

accurate estimates of these photodissociation rates must be made. The Models-3 CMAQ system 

includes the JPROC processor, which calculates a table of clear-sky photolysis rates (or J-values) 

for a specific date. 

8.2.5 Air Quality Input Preparation 

Air quality data used with the CMAQ and CAMx modeling systems include: (1) Initial 

Concentrations (ICs) that are the assumed three-dimensional concentrations through the 

modeling domain at the very start of the simulation; (2) the Boundary Conditions (BCs) that are 

the concentrations assumed along the lateral edges of the RPO national 36 km modeling domain; 

and (3) air quality observations that are used in the model performance evaluation are discussed 

in Section 3 and Appendix C of Appendix 8.1. 

8.2.6 Model Performance Evaluation 

The CMAQ and CAMx models were evaluated against ambient measurements of PM species, 

gas-phase species and wet deposition. Table 8.1 summarizes the networks used in the model 

evaluation, the species measured and the averaging times and frequency of the measurements. 

Table 8.1. Ground-level ambient data monitoring networks and stations available in the 

CENRAP states for calendar year 2002 use in the model performance evaluation. 

Monitoring 

Network Chemical Species Measured 

Sampling 

Frequency; 

Duration 

Approximate 

Number of 

Monitors 

IMPROVE Speciated PM2.5 and PM10 1 in 3 days; 24 hr 11 

CASTNET Speciated PM2.5, Ozone Hourly, Weekly; 

1 hr, 1 Week 

3 

NADP WSO4, WNO3, WNH4 Weekly 23 

EPA-STN Speciated PM2.5 Varies; Varies 12 

AIRS/AQS CO, NO, NO2, NOx, O3 Hourly; Hourly 25 

Numerous iterations of CMAQ and CAMx 2002 base case simulations and model performance 

evaluations were conducted during the course of the CENRAP modeling study, most of which 

have been posted on the CENRAP modeling website 

(http://pah.cert.ucr.edu/aqm/cenrap/cmaq.shtml) and presented in previous reports and 
37

presentations for CENRAP (e.g., Morris et al., 2005; 2006a,b). Details on the final 2002 Base F 

36 km CMAQ base case modeling performance evaluation are provided in Chapter 3 and 

Appendix C of Appendix 8.1, (because of the similarity between 2002 Base F and 2002 Base G 

and resource constraints the model evaluation was not re-conducted for Base G). In general, the 

model performance of the CMAQ and CAMx models for sulfate (SO4) and elemental carbon 

(EC) was good. Model performance for nitrate (NO3) was variable, with a summer 

underestimation and winter overestimation bias. Performance for organic mass carbon (OMC) 

was also variable, with the inclusion of the SOAmods enhancement in CMAQ Version 4.5 

greatly improving the CMAQ summer OMC model performance (Morris et al., 2006c). Model 

performance for Soil and coarse mass (CM) was generally poor. Part of the poor performance for 

Soil and CM is believed to be due to measurement-model incommensurability. The IMPROVE 

measured values are due, in part, to local fugitive dust sources that are not captured in the 

model’s emission inputs and the 36 km grid resolution is not conducive to modeling localized 

events. 

8.3 2018 Base G Model Year 

8.3.1 2018 Emissions Inventory 

The 2018 Base G modeling run reflects emissions growth and “on the books” controls, which are 

state and federal controls that will be implemented between the 2002 base year and the 2018 

future year.2018 emissions for Electrical Generating Units (EGUs) were based on simulations of 

the Integrated Planning Model (IPM) that took into the account the effects of the Clean Air 

Interstate Rule (CAIR) on emissions from EGUs in CAIR states using an IPM realization of a 

CAIR cap-and-trade program. Thus the Emissions for on-road and non-road mobile sources were 

based on activity growth and emissions factors from the EPA MOBILE6 and NONROAD 

models, respectively. Area sources and non-EGU point sources were grown to 2018 levels. 

The following sources were assumed to remain constant between the 2002 and 2018 base case 

simulations: 

• Biogenic VOC and NOx emissions from the BEIS3 biogenic emissions model; 

• Wind blown dust associated with non-agricultural sources (i.e., natural wind blown 

fugitive dust); 

• Off-shore emissions associated with off-shore marine and oil and gas production 

activities; 

• Emissions from wildfires; 

• Emissions from Mexico; and 

• Global transport (i.e., emissions due to BCs from the 2002 GEOS-CHEM global 

chemistry model. 
38

8.3.2 Model Performance Evaluation 

In this section, and in section 3 of Appendix 8.1, the results of the model performance evaluation 

at each of Arkansas’s Class I areas for the worst and best 20 percent days are presented. 

Performance on these days is critical since they are the days used in the 2018 visibility 

projections discussed in Chapter 8.6. The 2002 and 2018 modeling results were used in a relative 

sense to scale the observed PM concentrations from the 2000-2004 Baseline and the IMPROVE 

monitoring network to obtain the 2018 PM projections. The 2018/2002 modeled scaling factors 

are called Relative Response Factors (RRFs) and are constructed as the ratio of modeling results 

for the 2018 model simulation to the 2002 model simulation. Two important regional haze 

metrics are the average visibility for the worst 20 percent and best 20 percent days from the 

2000-2004 five-year Baseline. For the 2018 visibility projections, EPA guidance recommends 

developing Class I area and PM species specific RRFs using the average modeling results for the 

worst 20 percent days during the 2002 modeling period and the 2002 and 2018 emission 

scenarios. For each Class I area we compared the predicted and observed extinction of the worst 

and best 20 percent days below. In Appendix C of Appendix 8.1 the PM species specific 

extinction is also compared for the worst 20 percent days. 

EPA guidance recommends using the model in a relative sense to project future-year visibility 

conditions (EPA, 2007a). This projection is made using Relative Response Factors (RRFs) that 

are defined as the ratio of the future-year modeling results to the base-year modeling results. The 

RRFs are applied to the baseline visibility conditions to project future-year visibility. The major 

features of EPA’s recommended visibility projection approach are as follows : 

• Monitored data are used to define current visibility Baseline Conditions using 

IMPROVE monitoring data from the 2000-2004 five-year base period. 

• Monitored concentrations of PM10 are divided into six major components, the first five 

of which are assumed to be PM2.5 and the sixth is coarse mass (CM or PM2.5-10). 

• SO4 (sulfate) that is assumed to be ammonium sulfate [(NH4)2SO4]; 

• NO3 (particulate nitrate) that is assumed to be ammonium nitrate [NH4NO3]; 

• OC (organic carbon) that is assumed to be total organic mass carbon (OMC) 

• EC (elemental carbon); 

• IP (other fine inorganic particulate or Soil); and 

• CM (coarse mass). 

Models are then used in a relative sense to develop RRFs between baseline and future 

predicted concentrations of each component. Final projections were based on these RRFs, and 

indicate that while the model results may be off in absolute terms, the model still responds to 

increases or decreases in pollutants responsible for visibility impairment. This can lead to over or 

underestimation of light extinction for the various pollutants while still showing model 

applicability. 

8.3.2.1 Caney Creek Wilderness Area Modeling 

The ability of the CMAQ model to estimate visibility extinction at the CACR Class I area on the 

2002 worst and best 20 percent days is provide in Figure 8.2. On most of the worst 20 percent 
39

days at CACR total extinction is dominated by SO4 extinction with some extinction due to 

OMC. On four of the worst 20 percent days extinction is dominated by NO3. The average 

extinction across the worst 20 percent days is underestimated by -33% (Figure 8.2), which is 

primarily due to a -51% underestimation of SO4 extinction combined with a 6% overestimation 

of NO3 extinction. Performance for OMC extinction at CACR on the worst 20 percent days is 

pretty good with a -20% bias and 36% error. EC extinction is systematically underestimated. Soil 

extinction has low bias (-19%) buts lots of scatter and high error (74%), while CM extinction is 

greatly underestimated (bias of -153%). 

On the best 20 percent days at CACR the observed extinction ranges from 20 to 40 Mm-1, 

whereas, the modeled extinction has a much larger range from 15 to 120 Mm-1. Much of the 

modeled overestimation of total extinction on the best 20% days (+44% bias) is due to NO3 

overestimation (+94% bias).

Worst 20% Obs (left) vs Typ02g (right) at CACR1

0

50

100

150

200

250

300

350

400

80 128 143 155 170 173 188 191 200 203 215 218 221 239 242 248 251 254 257 260 296 320 341 _ _ Avg

Julian Day in Worst 20% group

bEXT (1/Mm)

bCM

bSOIL

bEC

bOC

bNO3

bSO4

Best 20% Obs (left) vs Typ02g (right) at CACR1

0

20

40

60

80

100

120

140

11 14 26 89 98 116 197 266 278 284 287 293 299 302 311 323 329 335 338 353 356 359 _ _ Av

Julian Day in Best 20% group

bEXT (1/Mm)

bCM

bSOIL

bEC

bOC

bNO3

bSO4

Figure 8.2. Daily extinction model performance at Caney Creek (CACR), Arkansas for the 

worst (top) and best (bottom) 20 percent days during 2002.
40

8.3.2.2 Upper Buffalo Wilderness Area Modeling 

Model performance at the UPBU Class I area for the worst and best 20 percent days is shown in 

Figure 8.3. On most of the worst 20 percent days at UPBU, visibility impairment is dominated 

by SO4, although there are also two high NO3 days. The model underestimates the average of 

the total extinction on the worst 20 percent days at UPBU by -40% (Figure 8.3), which is due to 

an underestimation of extinction due to SO4, OMC and CM by -46%, -33% and - 179%, 

respectively. 

 

On the best 20 percent days at UPBU, the model performs reasonably well with a low bias (2%) 

and error (42%). But again, the model has a much wider range in extinction values across the 

best 20 percent days (15 to 120 Mm-1) than observed (20 to 45 Mm-1). There are five days in 

which the modeled NO3 overprediction is quite severe and when those days are removed the 

range in the modeled and observed extinction on the best 20 percent days is quite similar to the 

observed, although the model gets much cleaner on the very cleanest modeled days. 

Worst 20% Obs (left) vs Typ02g (right) at UPBU1

0

50

100

150

200

250

300

350

128 143 158 170 173 179 191 197 203 206 215 218 221 224 239 242 248 251 254 257 269 296 320 332 _ Avg

Julian Day in Worst 20% group

bEXT (1/Mm)

bCM

bSOIL

bEC

bOC

bNO3

bSO4

Best 20% Obs (left) vs Typ02g (right) at UPBU1

0

20

40

60

80

100

120

14 26 47 68 89 98 116 119 164 167 176 227 266 278 281 287 290 302 311 323 335 353 _ _ Av

Julian Day in Best 20% group

bEXT (1/Mm)

bCM

bSOIL

bEC

bOC

bNO3

bSO4

Figure 8.3. Daily extinction model performance at Upper Buffalo (UPBU), Arkansas for the 

worst (top) and best (bottom) 20 percent days during 2002.
41

8.4 Information from Modeling Performed by Other RPOs 

2018 visibility projections for CENRAP and nearby Class I area have also been performed by the 

other RPOs. Thus, it is useful to compare the CENRAP 2018 visibility projections with those 

from the other RPOs as a quality assurance (QA) check and to foster confidence in the CENRAP 

modeling results. Detailed information concerning other RPOs modeling is found in Appendix 

8.1. 

The CENRAP 2018 Base G visibility projections were compared to the following other RPO 

visibility projections: 

• VISTAS 2018 visibility projections based on their CMAQ 12 km 2002 annual modeling results 

for the 2002 Base G and 2018 Base G2a emissions scenarios. 

• MRPO 2018 visibility projections based on their CAMx 36 km 2002 annual modeling for the 

Run 4 Scenario 1a (R4S1a) emissions scenario. 

• WRAP 2018 visibility results based on their Plan02b and Base18b CMAQ 36 km 

modeling of the 2002 calendar year. 

Figure 8.4 displays a DotPlot comparison of the four RPO visibility projections expressed as a 

percentage of achieving the 2018 URP point at CENRAP and nearby Class I areas. For the four 

CENRAP Class I areas just west of the Mississippi River in Arkansas and Missouri (CACR, 

UPBU, HEGL and MING), 2018 visibility projections are available from the CENRAP, VISTAS 

and MRPO RPOs. At HEGL, the three RPOs 2018 visibility projections are in close agreement 

with each other (estimated to achieve 99%, 101% and 95% of the 2018 URP point). The 

CENRAP and VISTAS 2018 visibility projections are also very close at the other three 

Arkansas-Missouri CENRAP Class I areas: CACR (112% and 116%), UPBU (109% and 112%) 

and MING (118% and 114%). But the MRPO 2018 visibility projections are approximately 12 to 

25 percentage points lower than the CENRAP and VISTAS projections at these three Class I 

areas, with values of 97% to 100%. The reasons why the MRPO 2018 visibility projections are 

less optimistic than CENRAP and VISTAS are unclear. However, the MRPO focused on 

visibility projections at their northern Class I areas and likely did not use the latest CENRAP 

emission estimates. In addition, the CENRAP 2018 visibility projections included BART 

controls on several sources in CENRAP states not included in the MRPO projections. Such 

BART controls are even more important in those states not covered by CAIR. 
42

CMAQ Method 1 predictions with new IMPROVE algorithm at CENRAP+ sites Across RPOs

0%

20%

40%

60%

80%

100%

120%

140%

BIBE1

GUMO1

WIMO1

CACR1

UPBU1

HEGL1

MING1

BRET1

VOYA2

BOWA1

MACA1

SIPS1

ISLE1

SACR1

WHIT1

WHPE1

GRSA1

ROMO1

WICA1

BADL1

THRO1

LOST1

Percent of target reduction achieved

CENRAP 36k Base18g/Typ02g

VISTAS 12k 2018g2b/2002gt2a

WRAP 36k Base18b/Plan02b corrected

MwRPO 2018 R4S1a

CENRAP non-CENRAP

Figure 8.4. DotPlot comparing the CENRAP, VISTAS, MRPO and WRAP 2018 visibility 

projections expressed as a percentage of achieving the 2018 URP goal. 

List of Chapter 8 Appendices

8.1 Technical Support Documentation for CENRAP Emissions and Air Quality Modeling to 

Support Regional Haze State Implementation. 
43

9. Best Available Retrofit Technology 

The U.S. EPA’s 1999 Regional Haze Rule (RHR) requires certain emission sources “that may 

reasonably be anticipated to cause or contribute” to visibility impairment in downwind Class I 

areas to install Best Available Retrofit Technology (BART) controls. States are required to 

determine the “degree of improvement in visibility which may reasonably result from the use of 

such technology.” On July 6, 2005, EPA published final amendments to its 1999 RHR in the 

Federal Register, including Appendix Y, “Guidelines for BART Determinations Under the 

Regional Haze Rule” (“Guidelines”), the final guidance for Best Available Retrofit Technology 

(BART) determinations (70 FR 39104-39172). 

The Arkansas Department of Environmental Quality (ADEQ) is requiring sources subject to 

BART to install, operate, and maintain BART rather than implement an emission trading 

program, or other alternative measure, in place of BART. 

 

9.1 BART – Eligible Sources in the State of Arkansas 

The facilities with BART-eligible units in Arkansas are shown in Figure 9.1 and Table 9.1. A 

detailed description of each BART-eligible emission units is included in Appendix 9.1A. 
44

RS BART-eligible Sources

Hercules-Glade Wilderness Area, MO

Upper Buffalo Wilderness Area, AR

Caney Creek Wilderness Area, AR

Mingo Wilderness Area, MO

Sipsey Wilderness Area, AL

Figure 9.1 Map showing Arkansas’s BART-eligible sources and the 300 km radius buffer zones 

around five separate receptors (north, south, east, west, and center) located in the following Class 

I areas: Upper Buffalo, Caney Creek, Hercules Glade, Mingo, and Sipsey. This map was 

developed to determine which Class I areas will be assessed during the BART determination 

modeling. 
Table 9.1 Facilities with BART-eligible Units in the State of Arkansas BART Sources Category Number and Name 

Facility Name/Location SIC Facility ID AFIN Unit ID Unit Description American Electric Power/Gentry (SWEPCO)* 

49 05-007-00107 04-0017 SN-01 Boiler 

AR Electric Cooperative/Augusta* 49 05-147-00024 74-00024 SN-01 Boiler 1350 mm AR Electric Cooperative/Camden* 49 05-103-00055 52-00055 SN-01 Boiler Entergy-Lake Catherine/Jones Mills 49 05-059-00011 30-00011 SN-02 Unit 4 Boiler Entergy-Ritchie Plant/Helena 49 05-107-00017 54-00017 SN-02 Unit2 Entergy-White Bluff/Redfield 49 05-069-00110 35-00110 SN-01 Unit 1 Entergy-White Bluff/Redfield 49 05-069-00110 35-00110 SN-02 Unit 2 

1. Fossil fuel-fired Electric Plants > 250 MMbtu/hour-Electric Generating Units (EGUs) 

Entergy-White Bluff/Redfield 49 05-069-00110 35-00110 SN-05 Auxiliary Boiler 

Domtar, Inc./Ashdown 26 05-081-00002 41-00002 SN-03 #1 Power Boiler Domtar, Inc./Ashdown 26 05-081-00002 41-00002 SN-05 #2 Power Boiler Delta Natural Kraft/Pine Bluff 26 05-069-00017 35-00017 SN-02 Recovery Boiler Evergreen Packaging/Pine Bluff 26 05-069-00016 35-00016 SN-04 # 4 Recovery BoileGeorgia-Pacific Paper/Crossett 26 05-003-00013 02-00013 SN-22 9A Boiler Green Bay Packaging/Morrilton 26 05-029-00001 15-00001 SN-05A Recover Boiler 

3. Kraft Pulp Mills 

Potlatch/McGehee 26 05-041-00036 21-00036 SN-04 Power Boiler 

11. Petroleum Refineries 

Lion Oil/El Dorado 29 05-139-00016 70-00016 SN-809 #7 Catalyst Regene

15. Sulfur Recovery Plant 

Albermarle-South Plant/Magnolia 28 05-027-00028 14-00028 SR-01 Tail Gas Incinerato

19. Sintering Plants Big River Industries/West Memphis 32 05-035-00082 18-00082 SN-01 Kiln A 

Albermarle-South Plant/Magnolia 28 05-027-00028 14-00028 BH-01 Boiler #1 Albermarle-South Plant/Magnolia 28 05-027-00028 14-00028 BH-02 Boiler #2 FutureFuels Chemical/Batesville 28 05-063-00036 31-00036 6M01-01 3 Coal Boiler El Dorado Chemical/El Dorado 28 05-139-00040 70-00040 SN-08 West Nitric Acid PEl Dorado Chemical/El Dorado 28 05-139-00040 70-00040 SN-09 East Nitric Acid Pl

21. Chemical Processing Plants 

El Dorado Chemical/El Dorado 28 05-139-00040 70-00040 SN-10 Nitric Acid Concen

* Please note: American Electric Power/Gentry (SWEPC) is permitted as Flint Creek Power Plant; AR Electric Cooperation/Augusta is permitted as ACarl E. Bailey Plant; and AR Electric Cooperation/Camden is permitted as AR Electric Cooperation Corporation – John L. McClellan Generating Stat
46

The BART-eligible sources were identified using the methodology in the “Guidelines”. (40 CFR 

Part 51, Appendix Y) To identify as BART-eligible emission units, ADEQ used the following 

“Guidelines” criteria: 

• One, or more, emission(s) units at the facility fit within one of the twenty-six (26) 

categories listed in the “Guidelines”; 

• The emission unit(s) were in existence on August 7, 1977 and began operation at some 

point on, or after, August 7, 1962; and 

• The sum of the potential emissions from all emission unit(s) identified using the previous 

two criteria were greater than 250 tons, or more, per year of the visibility-impairing 

pollutants: sulfur dioxide (SO2), nitrogen oxide (NOx), and PM10. 

The “Guidelines” recommend addressing the visibility-impairing pollutants: SO2, NOx, and 

Particulate Matter (PM). ADEQ addressed these three pollutants and used PM less than ten (10) 

micrometers (μm) in diameter (PM10) as an indicator for PM in the initial step of identifying 

BART-eligible units. Consistent with the “Guidelines”, ADEQ did not evaluate emissions of 

Volatile Organic Compounds (VOCs) and ammonia (NH3) in BART determinations, because 

only specific VOCs form secondary organic aerosols that affect visibility. These compounds are 

a fraction of the total VOCs reported in the emissions inventory, and ADEQ does not have the 

breakdown of VOC emissions necessary to model those that only impair visibility. Further, the 

prescribed screening model (CALPUFF) cannot simulate formation of particles from 

anthropogenic VOCs, nor their visibility impacts. Ammonia from specific sources will not be 

evaluated in this process, although ammonia is included in the modeling as a background 

concentration. The appropriate VOCs and ammonia emission data can, and will be, included in 

regional scale modeling used for the Regional Haze SIP. 

BART-eligible sources were determined by a review of ADEQ’s emission inventory database 

and a review of the permits and permit applications. A detailed description of the process is 

located in Appendix 9.1B. As shown in Table 9.1, this analysis indicated there were 27 facilities 

in Arkansas with BART-eligible units. 

9.2 Determination of Sources Subject-to-BART 

Under the “Guidelines”, ADEQ has the following options regarding its BART-eligible sources: 

a) make BART determinations for all sources or b) consider exempting some sources from 

BART because they do not cause or contribute to visibility impairment in a Class I area. ADEQ 

has chosen option b. If a State chooses option b, the “Guidelines” suggest the following three 

modeling options for determining which sources may be exempt: 

(1) Individual source attribution approach (dispersion modeling). 

(2) Use of model plants to exempt sources with common characteristics. 

(3) Cumulative modeling to show that no sources in a state are subject to BART. 
47

ADEQ has chosen sub-option 1 above to determine which sources are subject to BART. ADEQ 

performed a source-specific analysis to determine which sources cause or contribute to visibility 

impairment using the CALPUFF model. The CALPUFF modeling protocol used for 

determining which facilities are subject-to-BART is included in Appendix 9.2A. In accordance 

with the “Guidelines”, a contribution threshold of a 0.5 change (delta Δ) in deciview (dv) was 

used for determining which sources were subject to BART. The “Guidelines” provide States the 

discretion to set a lower dv threshold than 0.5 dv if “the location of a large number of BARTeligible sources within the State and in proximity to a Class I area justifies this approach.” The 

0.5 dv threshold was selected because ADEQ followed EPA’s BART Modeling Guidance (p 42) 

in sitting a threshold limit in determining whether a BART-eligible source is either subject-toBART or exempt. According to the aforementioned modeling guidance, an individual source will 

be considered to “cause visibility impairment” if the emissions results in a Δ dv that is greater 

than or equal to 1.0 dv on the visibility in a Class I area. Additionally, if the emissions from a 

source results in a Δ in visibility that is greater than or equal to 0.5 dv in a Class I area the source 

will be considered to “contribute to visibility impairment” (BART Final Rule, 40 CFR 51 p 

39113). Thus, ADEQ has set the threshold limit at 0.5 dv. 

Please note that ADEQ used the original (default) IMPROVE algorithm (Equation 1) in the 

BART determination modeling because the CALPUFF model was developed using Equation 1. 

Equation 1 

[ ]

[ ]

[ ]

[ ]

[ ]

[ ]

10

6.0

1

10

4

)(3

)(3

+

×+

×+

×+

×+

××+

≈ × ×

Coarse Mass

Fine Soil

Elemental Carbon

Organic Carbon

f RH Nitrate

fb RH Sulfate ext

The facilities with BART-eligible units found to be subject-to-BART by ADEQ are shown in 

Table 9.2 and Figure 9.2. Appendix 9.2B contains the CALPUFF modeling input and output 

files for each BART-eligible source. Facilities found to be subject-to-BART must complete a 

BART analysis. However, ADEQ worked closely with the facilities in their preparation of the 

BART engineering analyses. Additionally, it is ultimately the responsibility of ADEQ to either 

approve or reject the BART sources’ engineering analysis during the permitting process. 

Appendix 9.2C contains the post-control CALPUFF modeling input and output files for each 

subject-to-BART source. 
48

Table 9.2 Subject-to-BART sources in Arkansas 

BART Source 

Category 

Name 

Facility Name Facility ID Emission Units 

Subject-to-BART 

Pollutants Evaluated 

in BART 

Determination 

Contribution to 

Visibility 

Impairment 

 (Δ dv) 

American 

Electric 

Power/SWEPCO 

05-007-

00107 

Boiler SN-01 SO2, NOx, PM10, and 

PM2.5

See Appendix 

9.2B 

AR Electric 

Coop Bailey 

Plant 

05-147-

00024 

Boiler 1350 mm SN01 SO2, NOx, PM10, and 

PM2.5

See Appendix 

9.2B 

AR Electric 

Coop McClellan 

Plant 

05-103-

00055 

Boiler SN-01 SO2, NOx, PM10, and 

PM2.5

See Appendix 

9.2B 

Entergy Lake 

Catherine Plant 

05-059-

00011 

Unit 4 Boiler SN-03 SO2, NOx, PM10, and 

PM2.5

See Appendix 

9.2B 

Unit 1 SN-01 SO2, NOx, PM10, and 

PM2.5

See Appendix 

9.2B 

Unit 2 SN-02 SO2, NOx, PM10, and 

PM2.5

See Appendix 

9.2B 

1. Fossil fuelfired Electric 

Plants > 250 

MMbtu/hour 

– Electric 

Generating 

Units (EGUs) 

Entergy White 

Bluff Plant 

05-069-

00110 

Auxiliary Boiler SN05 SO2, NOx, PM10, and 

PM2.5

See Appendix 

9.2B 

# 1 Power Boiler 

SN-03 

SO2, NOx, and PM2.5 See Appendix 

9.2B 

3. Kraft Pulp 

Mills Domtar 05-081-

00002 # 2 Power Boiler 

SN-05 

SO2, NOx, and PM2.5 See Appendix 

9.2B 
49

RS Subject to BART Sources

Hercules-Glade Wilderness Area, MO

Upper Buffalo Wilderness Area, AR

Caney Creek Wilderness Area, AR

Mingo Wilderness Area, MO

Sipsey Wilderness Area, AL

Figure 9.2 Map showing Arkansas’ subject to BART sources and the 300 km buffers around 

Caney Creek Wilderness Area, Arkansas, Upper Buffalo Wilderness Area, Arkansas, HerculesGlade Wilderness Area, Missouri, Mingo Wilderness Area, Missouri, and Sipsey Wilderness 

Area, Alabama 

Cumulative Impact of Subject-to-BART Sources on Visibility

Additionally, in accordance to Federal Register (FR 39105) notice promulgating the 

“Guidelines”, ADEQ contracted with ENVIRON International Corporation and Alpine 

Geophysics, LLC to perform a cumulative BART modeling analysis of the 6 subject-to-BART 

facilities in Arkansas to evaluate the cumulative visibility impacts due to the aforementioned 
50

facilities at nearby Class I areas. Please refer to Appendix 9.2C for a detailed description of 

ENVIRON and Alpine Geophysics’ methodology and the Class I areas studied. 

Clean Air Interstate Rule and BART

The Clean Air Interstate Rule was finalized in May 2005 by EPA and applies to states in the 

eastern U.S. Reconsiderations were finalized March 2006. This rule addresses air pollution 

transport across state borders. EPA determined which states must reduce which pollutants based 

on modeling which showed how the travel of pollution affects non-attainment in other states. 

CAIR requires states to reduce NOx and/or SO2 emissions. Of the three programs in CAIR, 

Arkansas is required to participate in only the Ozone-Season NOx reductions program. Although 

EPA’s BART Modeling Guidance allows CAIR states to participate in the CAIR cap and trade 

program, the state of Arkansas is not eligible for the aforementioned trading program because 

Arkansas is in CAIR only for NOx during the ozone season. Therefore, in Arkansas CAIR is not

better than BART. Thus BART-eligible EGUs will be modeled for BART 

determination/exemption by ADEQ. 

9.3 Determination of BART Requirements for Subject-to-BART Sources 

BART-level emissions reductions for the subject to BART sources in Arkansas are shown in 

Tables 9.3a through 9.3d for each visibility impairing pollutant. The BART requirements in the 

RHR are intended to reduce emissions specifically from large emission units that, due to age, 

were exempted from other control requirements of the CAAA. BART emission limits for each 

pollutant are based on the following: the degree of reduction achievable through the application 

of the best system of continuous emission reduction, taking into consideration the technology 

available; the costs of compliance; the energy and the non-air quality environmental impacts of 

compliance; any pollution control equipment in use or in existence 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. However, a State is not required to make 

a determination of BART for SO2 or NOx if a BART-eligible source has the potential to emit less 

than forty (40) tons per year of such pollutant(s), or less than fifteen (15) tons per year for PM10. 

The BART analysis conducted by the facility for each subject-to-BART source is included in 

Appendix 9.3A. BART for each subject-to-BART source was determined by ADEQ using the 

methodology in the “Guidelines.” These BART emission standards will be included in the Title 

V operating permit for each source after this implementation plan is approved by EPA. A copy 

of Regulation 19 which contains these BART limits is included in Appendix 9.3C. Additionally, 

response to EPA comments concerning the BART analyses performed by the subject-to-BART 

facilities is included in Appendix 9.3B. All correspondence between ADEQ, subject-to-BART 

sources, and EPA is located in Appendix 9.4B. 

ADEQ is requiring that each subject-to-BART source install and operate BART as expeditiously 

as practicable, but in no event later than six years after the effective day of Arkansas Regulation 
51

19, Chapter 15 or five years after approval of the SIP or plan revision by EPA, whichever comes 

first. 
Table 9.3a BART-Level Emissions Reductions from the 2002 Baseline, Sulfur Dioxide (SO2) 

Source and 

Unit

Maximum 24-Hour 

Actual Emissions 

(lb/day)

Baseline Peak 24-

hour Emissions 

(lb/hr) 

BART Level of 

Control % 

Removal1

Future Peak 24-

hour Emission Rate 

(lb/hr) 

Emission 

Limit2

04-00107 

276-AOP-R1 

American Electric 

Power/SWEPCO 

SN-01 

113483.81 4728.49 78.3% 1026.08 0.15 lb/MMBtu 

74-00024 

154-AOP-R0 

AR Electric Coop 

Bailey Plant 

SN-01 

57018.10 2375.75 55% 1069.09 1034.17 lb/hr 

(1% S fuel oil) 

52-00055 

181-AOP-R1 

AR Electric Coop 

McClellan Plant 

SN-01 

65942.06 2747.59 65% 961.66 982.47 lb/hr 

(1% S fuel oil) 

41-00002 

287-AOP-R2 

Domtar 

SN-03 

10620 442.5 0% 442.5 1.12 lb/MMBtu 

41-00002 

287-AOP-R2 

Domtar 

SN-05 

18916.8 788.2 

0% 

(using existing 

scrubber) 

788.2 1.20 lb/MMBtu 

30-30-00011 

1717-AOP-R1 

Entergy Lake 

Catherine Plant 

SN-03 oil

126647.84 5276.99 46% 2860.4 0.562 lb/MMBtu 

(0.5% S fuel oil) 

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-01 

186319.32 7763.3 82% 1400.8 

0.15 lb/MMBtu 

(Bituminous & subbituminous coal) 

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-02 

187799.35 7825.0 80% 1533.2 

0.15 lb/MMBtu 

(Bituminous & subbituminous coal) 

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-05 

No emission standards have been established for this source. Rather the state has established work practice 

standards for this source pursuant to 40 CFR 51.308(e)(1)(iii). 

1. Only listed if facility is adding controls or taking limits that will reduce emission per BART requirements. 

Facilities which are not adding controls or using controls which are already installed have a 0% BART control 

efficiency. 

2. 30-day rolling average 

52
Table 9.3b BART-Level Emissions Reductions from the 2002 Baseline, Oxides of Nitrogen 

(NOx) 

Source and 

Unit

Maximum 24-Hour 

Actual Emissions 

(lb/day)

Baseline Peak 24-

hour Emissions 

(lb/hr) 

BART Level of 

Control % 

Removal1

Future Peak 24-

hour Emission Rate 

(lb/hr) 

Emission 

Limit2

04-00107 

276-AOP-R1 

American Electric 

Power/SWEPCO 

SN-01 

46680.0 1945 16.8% 1618.24 0.23 lb/MMBtu 

41-00002 

287-AOP-R2 

Domtar 

SN-03 

4309.0 179.54 0% 179.54 0.46 lb/MMBtu 

41-00002 

287-AOP-R2 

Domtar 

SN-05 

12643.2 526.8 30% 368.76 0.450 lb/MMBtu 

30-00011 

1717-AOP-R1 

Entergy Lake 

Catherine Plant 

SN-03 gas

58960.0 2456.67 69.6% 746.82 0.15 lb/MMBtu 

30-00011 

1717-AOP-R1 

Entergy Lake 

Catherine Plant 

SN-03 oil

60273.0 2511.38 47.6% 1315.96 0.25 lb/MMBtu 

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-01 

104920.0 4371.7 69% 1355.23 0.28 lb/MMBtu 

(bituminous coal) 

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-01 

104920.0 4371.7 69% 1355.22 0.15 lb/MMBtu 

(sub-bituminous coal)

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-02 

113540.0 4730.8 69% 1466.56 0.28 lb/MMBtu 

(bituminous coal) 

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-02 

113540.0 4730.8 69% 1466.56 0.15 lb/MMBtu 

(sub-bituminous coal)

35-00110 

263-AOP-R1 

Entergy White 

Bluff Plant 

SN-05 

No emission standards have been established for this source. Rather the state has established work practice 

standards for this source pursuant to 40 CFR 51.308(e)(1)(iii). 

1. Only listed if facility is adding controls or taking limits that will reduce emission per BART requirements. 

Facilities which are not adding controls or using controls which are already installed have a 0% BART control 

efficiency. 

2. 30-day rolling average 

53
Table 9.3c BART-Level Emissions Reductions from the 2002 Baseline, Particulate Matter 10 

micrometers (PM10) 

Source and 

Unit

Maximum 24-Hour 

Actual Emissions 

(lb/day)

Baseline Peak 24-

hour Emissions 

(lb/hr) 

BART Level of 

Control % 

Removal1

Future Peak 24-

hour Emission Rate 

(lb/hr) 

Emission 

Limit2

41-00002 

287-AOP-R2 

Domtar 

SN-03 

4068.0 169.5 

(filterable) 76% 40.6 0.07 lb/MMBtu 

41-00002 

287-AOP-R2 

Domtar 

SN-05 

1958.4 81.6 

(filterable) 

29.7% 

(using existing 

scrubber) 

57.4 0.10 lb/MMBtu 

1. Only listed if facility is adding controls or taking limits that will reduce emission per BART requirements. 

Facilities which are not adding controls or using controls which are already installed have a 0% BART control 

efficiency. 

2. 30-day rolling average 

Table 9.3d BART-Level Emissions Reductions from the 2002 Baseline, Particulate Matter 2.5 

micrometers (PM2.5) 

Source and 

Unit

Maximum 24-Hour 

Actual Emissions 

(lb/day)

Baseline Peak 24-

hour Emissions 

(lb/hr) 

BART Level of 

Control % 

Removal1

Future Peak 24-

hour Emission Rate 

(lb/hr) 

Emission 

Limit2

30-00011 

1717-AOP-R1 

Entergy Lake 

Catherine Plant 

SN-03 oil

6810.0 283.75 69.4% 86.83 

0.037lb/MMBtu 

(filterable & 

condensable) 0.5% S 

fuel oil 

1. Only listed if facility is adding controls or taking limits that will reduce emission per BART requirements. 

Facilities which are not adding controls or using controls which are already installed have a 0% BART control 

efficiency. 

2. 30-day rolling average 

54
55

9.4 Results and Conclusions 

To determine if there was a statistical significant improvement to visibility from the post-control 

emissions of Arkansas’ subject-to-BART sources, a student t (TTEST function in Excel) was 

performed. Tables 9.4a through 9.4g contain the maximum change (delta Δ) in deciview (dv) 

from the pre-control emissions, the maximum Δ dv from the post-control emissions, the percent 

decrease, the P value, and the number of days the Δ dv from the pre-control emissions were 

greater than or equal to (>) a Δ dv of 0.5. 

Table 9.4a American Electric Power results comparing the pre-control emissions and the postcontrol emissions to Caney Creek Wilderness Area (CACR) and Upper Buffalo Wilderness Area 

(UPBU), Arkansas and Hercules-Glade Wilderness Area (HEGL), Missouri 

Class I area Pre-control 

Maximum Δ

dv 

Post-control 

Δ dv 

Percent 

Change 

Is P < 0.05 Number of Days 

Pre-control Δ dv >

0.5 

CACR 3.970 1.573 60.38 Yes 106 

UPBU 3.781 2.089 44.75 Yes 139 

HEGL 3.983 1.541 61.31 Yes 117 

Table 9.4b Arkansas Electric Coop – Carl E. Bailey results comparing the pre-control emissions 

and the post-control emissions to Caney Creek Wilderness Area (CACR) and Upper Buffalo 

Wilderness Area (UPBU), Arkansas and Hercules-Glade Wilderness Area (HEGL) and Mingo 

Wilderness Area (MING), Missouri 

Class I area Pre-control 

Maximum Δ

dv 

Post-control 

Δ dv 

Percent 

Change 

Is P < 0.05 Number of Days 

Pre-control Δ dv >

0.5 

CACR 1.841 0.897 51.28 Yes 28 

UPBU 1.232 0.574 53.41 Yes 23 

HEGL 1.594 0.809 49.25 Yes 30 

MING 1.660 0.766 53.86 Yes 45 

Table 9.4c Arkansas Electric Coop – McClellan results comparing the pre-control emissions and 

the post-control emissions to Caney Creek Wilderness Area (CACR) and Upper Buffalo 

Wilderness Area (UPBU), Arkansas 

Class I area Pre-control 

Maximum Δ

dv 

Post-control 

Δ dv 

Percent 

Change 

Is P < 0.05 Number of Days 

Pre-control Δ dv >

0.5 

CACR 2.197 1.011 53.98 Yes 58 

UPBU 1.196 0.487 59.28 Yes 23 
56

Table 9.4d Domtar results comparing the pre-control emissions and the post-control emissions to 

Caney Creek Wilderness Area (CACR) and Upper Buffalo Wilderness Area (UPBU), Arkansas 

Class I area Pre-control 

Maximum Δ

dv 

Post-control 

Δ dv 

Percent 

Change 

Is P < 0.05 Number of Days 

Pre-control Δ dv >

0.5 

CACR 2.262 2.038 9.90 Yes 149 

UPBU 1.181 1.029 12.87 No 18 

Table 9.4e Entergy – Lake Catherine results comparing the pre-control emissions from natural 

gas and the post-control emissions from natural gas to Caney Creek Wilderness Area (CACR) 

and Upper Buffalo Wilderness Area (UPBU), Arkansas and Hercules-Glade Wilderness Area 

(HEGL), Missouri 

Class I area Pre-control 

Maximum Δ

dv 

Post-control 

Δ dv 

Percent 

Change 

Is P < 0.05 Number of Days 

Pre-control Δ dv >

0.5 

CACR 3.209 1.111 63.48 Yes 87 

UPBU 2.186 0.753 66.55 Yes 54 

HEGL 1.663 0.558 66.45 Yes 23 

Table 9.4f Entergy – Lake Catherine results comparing the pre-control emissions from fuel oil 

and the post-control emissions from fuel oil to Caney Creek Wilderness Area (CACR) and Upper 

Buffalo Wilderness Area (UPBU), Arkansas and Hercules-Glade Wilderness Area (HEGL), 

Missouri 

Class I area Pre-control 

Maximum Δ

dv 

Post-control 

Δ dv 

Percent 

Change 

Is P < 0.05 Number of Days 

Pre-control Δ dv >

0.5 

CACR 6.607 3.671 36.49 Yes 201 

UPBU 2.953 1.636 44.60 Yes 188 

HEGL 4.129 2.397 41.95 Yes 134 

Table 9.4g Entergy – White Bluff results comparing the pre-control emissions and the postcontrol emissions from to Caney Creek Wilderness Area (CACR) and Upper Buffalo Wilderness 

Area (UPBU), Arkansas and Hercules-Glade Wilderness Area (HEGL), Missouri 

Class I area Pre-control 

Maximum Δ

dv 

Post-control 

Δ dv 

Percent 

Change 

Is P < 0.05 Number of Days 

Pre-control Δ dv >

0.5 

CACR 8.677 2.665 69.29 Yes 245 

UPBU 7.948 2.167 72.74 Yes 242 

HEGL 6.631 2.030 97.97 Yes 234 

The results from the ENVIRON cumulative modeling using Comprehensive Air-quality Model 

with extensions (CAMx) PM Source Apportionment Technology (PSAT) is estimated to result in 

substantial improvements in visibility to all 10 Class I areas studied, with the largest visibility 

improvement of 5 Δ dv at Mingo Wilderness Area, Missouri. (Please refer to Appendix 9.2C for 

ENVIRON and Alpine Geophysics’ final report.) The highest cumulative visibility impacts due 
57

to all PM species in the pre-control base case ranged from 4 to 11 Δ dv across the Class I areas, 

whereas the highest visibility impacts in the post-control case ranged from 1 to 7 Δ dv. Despite 

these apparent visibility improvements, the cumulative visibility impacts due to all Arkansas 

BART sources in the post-control case still exceed 1 Δ dv at most Class I areas of interest. 

During the modeling process, ADEQ was informed that the emissions provided for the Domtar 

Arkansas subject-to-BART source were understated. To address this issue, a sensitivity analysis 

was performed by ENVIRON using the corrected Domtar emissions for both the pre- and postcontrol scenarios was conducted. The analysis suggested that the revised (higher) Domtar 

emissions worsen the visibility improvement in the post-control case, specifically by 2 Δ dv at 

Caney Creek Wilderness Area, Arkansas. 

In summary, there is an improvement in visibility from the post-control emissions of the State of 

Arkansas’s subject-to-BART sources at all Class I areas assessed by ADEQ. Appendix 9.4A 

contains charts comparing the pre- and post-control emissions of Arkansas’ subject-to-BART 

sources. These charts also indicate there is a considerable improvement to visibility from the 

post-control emissions of Arkansas’s subject-to-BART sources. 

List of Chapter 9 Appendices

 

9.1A Detailed Description of BART-eligible Emission Units 

9.1B Method of Identifying BART-Eligible Sources in the State of Arkansas 

9.2A Modeling Protocol Used to Determine Subject-to-BART Sources 

9.2B BART-exemption CALPUFF Modeling Input and Output Files 

9.2C Subject-to-BART CALPUFF Post-control Modeling Input and Output Files 

9.2D ENVIRON Final Report 

9.3A BART Analyses for the Subject-to-BART Sources 

9.3B Response to EPA Comments on BART Engineering Analyses 

9.3C Copy of Regulation 19 

9.3D Regulation 19 Supporting Documents 

9.4A Charts Comparing Arkansas’s subject-to-BART Sources’ Pre- and Post-control 

9.4B Correspondence 
58

 

10. Reasonable Progress Goals 

Federal regulations at 40 CFR 51.308(d)(1) require the State of Arkansas to establish Reasonable 

Progress Goals (RPGs) for achieving natural visibility for each Class I area within the state. The 

State is required to develop RPGs that provide for visibility improvement for the most impaired 

days and ensure no degradation in visibility for the least impaired days throughout the year. 

These goals are expressed in units of deciviews (dv). A deciview is a measurement of haze, 

implemented in a Haze Index (HI), derived from calculated light extinction. The RPGs are 

established in the State Implementation Plan (SIP) and are used to track progress towards the 

ultimate goal of achieving natural visibility conditions by 2064. 

In September 2003, EPA released a technical guidance document describing the techniques used 

to determine baseline and natural visibility conditions1

. The EPA has also released guidance 

describing various procedures that might be used to establish RPGs2

. The goals must provide 

improvement in visibility for the most impaired days, and ensure no degradation in visibility for 

the least impaired days for the duration of the SIP. The State must also provide an assessment of 

the number of years it would take to attain natural visibility conditions if improvement continues 

at the rate represented by the RPG. The above-referenced EPA guidance describes the meaning 

of the term Reasonable Progress Goal:

States must establish RPGs, measured in deciviews (dv) for each Class I area for 

the purpose of improving visibility on the haziest days and ensuring no 

degradation in visibility on the clearest days over the period of each 

implementation plan. RPGs are interim goals that represent incremental visibility 

improvement over time toward the goal of natural background conditions and are 

developed in consultation with other affected States and Federal Land Managers 

(FLMs). 

In determining what would constitute reasonable progress, Section 169A(g) of 

the CAA requires States to consider the following four factors: 

• 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 existing sources that contribute to visibility 

impairment. 

States must demonstrate in their SIPs how these factors are taken into consideration in 

selecting the RPG for each Class I area in the State. 

1 Guidance for Tracking Progress Under the Regional Haze Rule, EPA – 09/03. 

2 Guidance for Setting Reasonable Progress Goals Under the Regional Haze Program, EPA – 06/01/07 
59

The “Uniform Rate of Progress” (URP) described in the EPA guidance, described as “uniform 

rate of improvement” in 40 CFR 51.308(d)(1)(i)(B), is graphed on a timeline as a line between 

the “baseline conditions” representing visibility for the best and worst days at the time the 

regional haze program is established and natural background levels in 2064. Table 10.1 provides 

the URP for Class I Areas in the State of Arkansas. Figures 10.1 and 10.2 depict the URP for 

each Class I area in Arkansas as a “glide path.” 

Table 10.1 - Uniform Rate of Progress for Arkansas Class I Areas 

Class I Area Deciview 

Improvement 

Needed by 2018 

assuming URP 

(dv) 

Progress 

Annually to 

2018 assuming 

URP 

(dv/yr) 

Deciview 

Improvement 

Needed by 2064 

(dv) 

Caney Creek 3.45 - 0.25 14.78 

Upper Buffalo 3.43 - 0.25 14.70 
60

Fig.10.1 

Year

0.00

5.00

10.00

15.00

20.00

25.00

30.00

2004 2014 2024 2034 2044 2054

Haze Index

(deciviews)

Uniform Rate

of Progress = 14.78 dv X 14 yr

 60 yr

 = 3.45 dv Over First Planning Period

Natural 

Conditions for 

the 20% 

Worst Days

Baseline

First Planning 

Period

2064

Uniform Rate of Progress for the Caney Creek Wilderness Area, Arkansas
61

Uniform Rate of Progress for the Upper Buffalo Wilderness Area, Arkansas

30

Fig. 10.2 

0

5

10

15

20

25

2004 2014 2024 2034 2044 2054 2064

Year

Baseline

Haze Index

(deciview)

Natural 

Conditions 

for the 20% 

Worst Days

Uniform Rate

of Progress =14.70 dv X 14 yr

 60 yr

 = 3.43 dv Over First Planning Period First Planning

Period
62

10.2 Determination of Reasonable Progress Goals 

The State of Arkansas has determined that the rates of visibility improvement by 2018 that are 

expressed in Table 10.2 are reasonable and hereby adopts them as the Reasonable Progress Goals 

for the listed Class I areas. An analysis showing that these goals are reasonable is provided in 

Appendix 10.1, - Analysis of Control Strategies and Determination of Reasonable Progress 

Goals. Figures 10.3 - 10.6 show comparisons of URP, RFP and anticipated improvement in 

visibility on best days for each Class I Area. The established RPGs show that Caney Creek 

Wilderness Area can attain the goal of background conditions by CY 2062 and the Upper 

Buffalo Wilderness Area can achieve background conditions by CY 2063. These RPGs exceed 

the URPs established for these areas and would result in a return to natural background 

conditions prior to CY 2064. 

Table 10.2 - Reasonable Progress Goals for Arkansas Class I Areas

Class I 

Area 

Deciview 

Improvement 

Projected by 

CY 2018 

using RPG 

(dv) 

Deciview 

Improvement by 

CY 2018 at URP 

(dv) 

Projected 

Annual Rate 

of 

Improvement 

2008-2018 

(dv/yr) 

Projected Deciview 

Improvement by 

CY 2064 

(dv) 

Caney 

Creek 3.88 3.45 - 0.32 15.38 

Upper 

Buffalo 3.75 3.43 - 0.28 15.02 
63

Uniform Rate of Progress and Reasonable Progress Goal for the Twenty Percent 

(20%) Worst Days at Caney Creek Wilderness Area, Arkansas

30

Fig. 10.3 

0

5

10

15

20

25

2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 2044 2048 2052 2056 2060 2064

Year

Haze Index (Deciviews)

Baseline

Natural

Conditions

Uniform Rate

 of Progress = 14.78 dv X 14 yr

 60 yr

 = 3.45 dv Over First Planning Period

22.86

22.4 First Planning 

Period
64

Uniform Rate of Progress and Demonstration of "No Degradation" for the Twenty Percent 

(20%) Best Days at Caney Creek Wilderness Area, Arkansas

0

2

4

6

8

10

12

2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 2044 2048 2052 2056 2060 2064

Year

Haze Index (Deciviews)

10.35

11.24 11.24 11.24 11.24 11.24 11.24

First Planning

Period

Baseline

Fig. 10.4 
65

Uniform Rate of Progress and Reasonable Progress Goal for the Twenty Percent (20%) 

Worst Days for Upper Buffalo Wilderness Area, Arkansas

0

5

10

15

20

25

30

2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 2044 2048 2052 2056 2060 2064

Year

Uniform Rate

of Progress = 14.70 dv X 14 yr

 60 yr

 = 3.43 dv Over First Planning Period

First Planning

Period

Baseline

Natural

Conditions

Haze Index

(Deciviews)

22.84

22.52

Fig. 10.5 
66

Uniform Rate of Progress and Demonstration of "No Degradation" for the Twenty 

Percent (20%) Best Days at Upper Buffalo Wilderness Area, Arkansas

0

2

4

6

8

10

12

14

2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 2044 2048 2052 2056 2060 2064

Year

Haze Index (Deciviews) 11.71 11.71 11.71 11.71 11.71 11.71 11.71

10.80

Baseline

First Planning

Period

Fig. 10.6 
67

10.3 Consultation 

In determining a reasonable progress rate for each Class I area, the State of Arkansas has 

consulted with the other states and Tribes which are reasonably anticipated to cause or contribute 

to visibility impairment in each of these Class I areas. A description of the consultations that 

were hosted by Arkansas and Missouri is provided in Appendix 10.2., Interagency Consultation 

Process in Establishing Reasonable Progress Goals. 

On February 26, 2007, an invitation letter was sent to 12 States and tribes in the region. The 

invitation included a consultation plan that detailed the procedures and timelines for identifying 

possible contributors to regional haze in Arkansas and Missouri Class I Areas. These 

consultations were accomplished through a series of conference calls and letters. Calls were held 

on April 3, May 11 and June 7, 2007. Participants included States and tribes, EPA personnel, 

FLMs and other Regional Planning Organizations. A summary of these conference calls can be 

found on the CENRAP website. Correspondence between Arkansas, FLMs, Oklahoma, 

Kentucky, Tennessee, Missouri and Texas is included in Appendix 10.3 – Arkansas Consultation 

Letters. 

10.4 Reporting 

Progress will be reported to the EPA every five years in accordance with the requirements of 

51.308 (g). 

List of Chapter 10 Appendices

10.1 Analysis of Control Strategies and Determination of Reasonable Progress Goals 

10.2 Interagency Consultation Process in Establishing Reasonable Progress Goals 

10.3 Arkansas Consultation Letters 
68

11. Long-term Strategy to Reach Reasonable Progress Goals 

11.1 Federal Requirements 

40 CFR 51.308(d)(3) requires the State of Arkansas to submit a long-term strategy that addresses 

regional haze visibility impairment for each mandatory Class I federal area within and outside 

the State which may be affected by emissions from within the State. The long-term strategy 

must include any enforceable emissions limitations, compliance schedules and other measures 

considered necessary to achieve the RPGs described in Chapter 10. This chapter describes the 

long-term strategy of the State of Arkansas. 

11.2 Consultation 

40 CFR 51.308(d)(3)(i) requires Arkansas to consult with other states and tribes to develop 

coordinated emission strategies. This requirement applies both where emissions from the State 

are reasonably anticipated to contribute to visibility impairment in Class I areas outside the State 

and when emissions from other states or tribes are reasonably anticipated to contribute to 

visibility impairment in Class I areas within the State. 

The State of Arkansas has consulted with other states and tribes by its on-going participation in 

CENRAP. The monitoring analysis, emission inventory, modeling assessments and control 

strategy assessments that have been conducted by CENRAP on behalf of its member states and 

tribes have all been done through a collaborative process that is inherently consultative in nature. 

In addition, the State of Arkansas has participated in discussions focused on Class I areas 

through-out the CENRAP region and in neighboring states which involved the states and tribes 

listed in Appendix 10.2 – Interstate Consultations. Strategy development considered the 

impacts of the State’s emissions on Class I areas within and outside the State.

The manner in which the State of Arkansas has coordinated with FLMs on long-term strategy 

development is described in Chapter 4. 

Arkansas will continue to consult with states, tribes, FLMs, EPA and other stakeholders to the 

extent necessary to assure that RPGs are achieved. Progress reports and plan updates will be 

communicated to stakeholders as they become available. On-going consultations will be in the 

form of written communications, conference calls and meetings on an as-needed basis. 

In addition to the consultations held jointly by Arkansas and Missouri, Arkansas participated in 

consultations hosted by Oklahoma. No other states or Tribes have indicated that Arkansas was 

potentially contributing to visibility impairment in their Class 1 areas. 
69

11.3 Share of Emission Reductions

40 CFR 51.308(d)(3)(ii) requires the State of Arkansas to demonstrate that its implementation 

plan includes all measures necessary to obtain its fair share of emission reductions needed to 

meet RPGs in other Class 1 areas. 

Arkansas and Missouri relied on technical analyses developed by CENRAP, additional weight of 

evidence analyses prepared by Missouri as part of the Central Class 1 Areas Consultation Plan 

and in-house screening of BART-eligible sources to determine which states might reasonably 

cause or contribute to haze in its Class 1 areas. In addition to its own sources, states with 

emissions that were determined to have potential impacts on Arkansas’s Class 1 areas included 

Iowa, Nebraska, Missouri, Illinois, Indiana, Ohio, Kentucky, Tennessee, Oklahoma and Texas. 

These states and tribal representatives from these states were included in the consultation process 

described in the Consultation Plan. CENRAP-modeled visibility projections indicate that the 

emission reductions planned for these states are sufficient to achieve the RPGs for all Class 1 

areas located in Arkansas and Missouri. 

CENRAP and ADEQ analyses indicate that the impact of anthropogenic emissions from 

Arkansas sources have not been shown to appreciably affect visibility in Class 1 areas other than 

the four located in Arkansas and Missouri. Visibility projections for each of these areas show 

that they will all be able to demonstrate a better than uniform rate of progress through the 

implementation of existing and forthcoming State and federal emission reduction programs. The 

emission reductions described elsewhere herein are sufficient to constitute a fair share of 

emission reductions needed to meet RPGs in affected Class I areas. 

The demonstration of attainment of RPGs relies on the analysis of monitored and modeled data 

in a weight of evidence analysis to determine whether visibility is improved on days when it is 

usually poor and does not deteriorate on days when it is usually good. Current visibility is 

estimated from monitored components of PM2.5 and coarse mass. Models are used in a relative 

sense to estimate how current concentrations respond to emission reduction measures. Data 

analysis is used to identify source categories and regions. Current concentrations of particulate 

matter components are adjusted by the relative modeled response to estimate concentrations at 

the end the first implementation period in 2018. Future visibility is estimated from estimated 

component concentrations of PM2.5 and coarse particulate matter at the end of the first 

implementation period. The difference between present visibility and future estimated visibility 

is compared with the reasonable progress goal to determine if the goal is met. 

The CENRAP technical report on current visibility conditions is found in Appendix 5.1, 

Determination of Baseline Visibility Conditions. CENRAP technical reports on current and 

projected inventories and regional modeling are found in Chapters 7 and 8 respectively. All 

applicable measures reflected in the modeling demonstration and weight-of-evidence analyses 

have been incorporated in the State’s long-term strategy. 
70

11.4 Long-term Strategy Elements 

40 CFR 51.308(d)(3)(v) requires the State of Arkansas to consider several factors in developing 

its long-term strategy. These are discussed below.

11.4.1 Emission Reductions due to On-going Air Pollution Programs. 

40 CFR 51.308(d)(3)(v)(A) requires the State of Arkansas to consider emission reductions from 

ongoing pollution control programs in the development of its long-term strategy. 

The State of Arkansas considered the following ongoing programs in developing its long-term 

strategy: 

11.4.1.1 Clean Air Interstate Rule (CAIR) 

40 CFR 96 Subparts AAAA-HHHH (with the exception of Subpart EEEE) for the CAIR NOx

Ozone Season Trading Program, as finalized by the U.S. EPA on May 12, 2005, and further 

revised by EPA on April 28, 2006, with correcting amendments on December 13, 2006, were 

incorporated by reference as Chapter 14 of Arkansas Pollution Control and Ecology Commission 

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

Control on September 28, 2007. 

By 2015, the State ozone season trading budget for annual NOx allocations will be capped at 

9,596 tons. This represents a reduction of 1,919 tons NOx per period from 2009’s budget of 

11,515 tons NOx per period. 

11.4.1.2 Best Available Retrofit Technology (BART Rule) 

Chapter 15 of Arkansas Pollution Control and Ecology Commission Regulation No. 19 – 

Regulations of the Arkansas Plan of Implementation for Air Pollution Control identifies BART 

eligible sources, subject to BART sources, numeric emissions limits for NOx, SO2 and particulate 

matter and other requirements applicable to BART sources. These controls are required to be in 

place by no later than CY 2013. 

 

11.4.1.3 Tier 2 Vehicle Emission Standards 

Federal Tier 2 Vehicle Emission standards for passenger cars and light trucks have been in effect 

since 2004 and were fully implemented in 2007. Similar rules for heavy trucks are scheduled to 

be fully implemented by 2009. These rules will result in reductions of emissions of particulate 

matter, ozone precursor pollutants and non-methane organic compounds. Reductions in these 
71

 

pollutants will contribute to improvements in visibility in Class I areas and throughout the 

country. 

11.4.1.4 Ultra Low Sulfur Diesel, Clean Air Highway and Nonroad Diesel Rules 

These federal rules will result in significant reductions in visibility-related pollutants emitted 

from diesel engines. The low sulfur content mandated by the Ultra Low Sulfur Diesel Rule will 

result in being able to better control particulate emissions from diesel engines by allowing 

installation of control devices that were technically infeasible for fuels with higher sulfur 

content. 

11.4.1.5 Measures to mitigate the impacts of construction activities.

40 CFR 51.308(d)(3)(v)(B) requires the State of Arkansas to consider measures to mitigate the 

impacts of construction activities. 

In Arkansas, ADEQ is responsible for all air pollution control programs. Due to certain 

limitations on regulatory authorities that are included in the Arkansas Water and Air Quality 

Control Act, the opportunities to mitigate air emissions from construction activities are limited3.

 

ADEQ does anticipate that current and future federal programs will result in some mitigation and 

has undertaken efforts to provide incentives for voluntary measures that can result in emission 

reductions. 

The federal General Conformity program requires assessments of the potential impacts of any 

construction activity-related emissions of criteria air pollutants from federal projects in areas that 

have been designated as not attaining the National Ambient Air Quality Standard (NAAQS) for 

that pollutant. These criteria pollutants include, among others, PM 2.5 and ozone (some ozone 

precursor compounds contribute to visibility conditions). At the current time, there is only one 

county in Arkansas in non-attainment for the ozone standard and no counties in non-attainment 

for other criteria pollutants. 

ADEQ has undertaken several initiatives to obtain reductions from on-road and off-road engines, 

including construction equipment throughout the State. Grant funds have been directed to fleet 

managers and equipment suppliers as a means of subsidizing diesel retrofits and the biodiesel 

market. ADEQ participates in a regional “Blue Skyways” group that works collaboratively on 

3 Section 8-4-305 of The Arkansas Water and Air Pollution Control Act states that “The 

provisions of this subchapter do not apply to: ---; (4) Land clearing operations or land 

grading; (5) Road construction operations and the use of mobile and portable equipment and 

machinery incident thereto; ---.” It would require legislative action for these exceptions to be 

removed from the Act and to give ADEQ explicit regulatory authority over these activities. 
72

the introduction of innovative, regional-scale, transportation-related programs and projects. 

These efforts are on-going. 

 

11.4.1.6 Source retirement and replacement schedules 

40 CFR 51.308(d)(3)(v)(D) requires the State of Arkansas to consider source retirement and 

replacement schedules in developing reasonable progress goals. Retirement and replacement 

will be managed in conformance with existing SIP requirements pertaining to PSD and New 

Source Review. Source retirement and replacement will be tracked through on-going point 

source inventories. 

Emission limitations and schedules of compliance. 

40 CFR 51.308(d)(3)(v)(C) requires the State of Arkansas to identify additional measures to 

meet RPGs when on-going programs alone are not sufficient to meet the RPGs. The State of 

Arkansas has determined that on-going State and federal air pollution control programs are

sufficient to meet RPGs through 2018. Emissions reductions at non-BART facilities or new 

control programs for other anthropogenic source categories will not be required at this time. 

11.4.1.7 Agricultural and Forestry Smoke Management 

40 CFR 51.308(d)(3)(v)(E) requires Arkansas to consider smoke management techniques for the 

purposes of agricultural and forestry management. In 2007, the Arkansas Forestry Commission, 

approved revisions to the Arkansas Smoke Management Plan (SMP). The Arkansas Smoke 

Management Plan is designed to assure that prescribed fires are planned and executed in a 

manner designed to minimize impacts associated with the smoke produced by prescribed fires. 

Arkansas has adopted a basic Smoke Management Program (SMP), in which owners/managers 

voluntarily notify state officials of fire plans. Documentation of this program is in Appendix 

11.1. 

Arkansas’s SMP recommends a written fire plan that includes measures that can be taken to 

reduce residual smoke from burning activities. Arkansas’s SMP recommends these actions to 

reduce smoke impacts where applicable: 

• Reduce the fuel loading in the area to be burned by mechanical means or by using 

frequent, low-intensity burns to gradually reduce fuels. 

• Reduce the amount of fuel consumed by the fire by burning when fuel moistures 

for larger fuels and duff moistures are high. 
73

• Rapid and complete mop-up after the burn or mop-up of certain fuels. 

• Reference “Smoke Management Guide for Prescribed Fire and Wildland Fire” by 

National Wildfire Coordinating Group Fire Use Working Team, publication 

NFES 1279. 

In addition, the Arkansas SMP has a process to evaluate potential smoke impacts at sensitive 

receptors and schedule fires to minimize exposure of sensitive populations and avoid visibility 

impacts in Class I areas. Arkansas’s SMP details procedures for the identification of smokesensitive targets and minimization of their exposure to smoke. Methodologies to reduce smoke 

exposure include smoke emissions estimates using determination of available fuels and 

identification of the category day based on local weather conditions forecast. 

Arkansas’s SMP details the AFC Dispatch Center’s role in locating each prescribed fire in the 

center of an airshed. This system estimates the range in tons of fuel that can be allocated to an 

airshed based upon downwind distance to the nearest smoke sensitive target and monitors the 

total fuel loading tonnage burned within each air shed, each day, in order to ensure compliance 

with permissible limits. If the AFC Dispatch center determines that the fuel tonnage for a single 

prescribed fire causes the air pollution tonnage for a given airshed to exceed these limits, the 

AFC Dispatch Center will recommend to the prescribed fire manager that the plan should be 

altered by measures such as delaying the burn and reducing the acreage to be burned. 

Arkansas has a public notification process and exposure reduction process in place to reduce the 

impacts of burning. The AFC, in cooperation with the Arkansas Prescribed Fire Committee, will 

explain the use and importance of fire for ecosystem management, the implications of smoke to 

public health and safety, and the goals of the SMP. This public awareness effort will use posters, 

pamphlets, news releases, and public presentations. Prescribed fire managers are encouraged to 

train on-the-ground personnel to understand the SMP. AFC will cooperate with organizations 

and government agencies such as Arkansas Lung Association or ADEQ to make the public 

aware of planned prescribed fires. 

Arkansas’s SMP states monitoring of the smoke from the prescribed fire should match the size of 

the fire. For small or short duration fires (such as those in grass or leaf litter), visual monitoring 

of the directions of the smoke plume and monitoring nuisance complaints by the public may be 

sufficient. Other monitoring techniques include posting personnel on vulnerable roadways to 

look for visibility impairment and to initiate safety measures for motorists; posting personnel at 

other smoke sensitive areas to look for smoke intrusions; using aircraft to track the progress of 

smoke plumes; and continued tracking of meteorological conditions during the fire. For 

prescribed fires in fuels with longer duration burning (such as timber litter or slash), and which 

are expected to last more than one day, locating real-time particulate matter (PM) monitors at 

smoke- sensitive areas may be warranted to facilitate timely response to smoke problems. 
74

The AFC has established a policy to issue health advisories when necessary. State and federal 

prescribed fire managers routinely notify landowners adjacent to prescribed burns of the 

potential for exposure to smoke. AFC Dispatch is currently developing a daily listing of planned 

prescribed fires on the AFC website (www.forestry.state.ar.us). The planned prescribed burn 

listing will have the county, nearest community, legal description, planned ignition time and 

acres of the prescribed burn. 

Arkansas’s SMP has provisions for an annual review by the Arkansas Forestry Commission that 

will include the following activities: 

• Collect and review information on acres burned by prescribed fire and wildfire 

• Review the reference, continuous, and IMPROVE monitoring station data 

maintained by ADEQ 

• Use information from reports of nuisance complaints or significant smoke 

intrusions to measure the effectiveness of the SMP 

• Provide recommendations to ADEQ and Arkansas Prescribed Fire Committee 

concerning the SMP 

Pursuant to the EPA’s Interim guidance cited above, Arkansas has adopted a program that should 

help prevent NAAQS violations and addresses visibility impairment due to fires. This program 

established the documentation of basic parameters: contact information of person in charge, 

purpose of prescribed burn, fuel type and tonnage, ignition time and duration of fire, wind speed, 

direction, location, and distance to sensitive receptors. Prescribed fire managers are required 

under Arkansas law to notify the AFC Dispatch Center on the morning of the prescribed fire by 

calling 1-800-830-8015. See Arkansas Code Annotated §20-22-302. 

11.4.1.8 Additional Control Measures 

The CENRAP modeling shows that Arkansas’s Class 1 areas can achieve the 2018 RPGs without 

additional control measures beyond those described above. In the situation where anticipated 

emission reductions produce a 2018 outcome that meets the goal of natural background 

conditions, it is not immediately necessary to evaluate the need for additional control measures. 

A four-factor analysis was included as part of the engineering analysis for all BART eligible 

sources in Arkansas. Since Arkansas has demonstrated that it can meet or exceed established 

URPs, it is not necessary to evaluate the emission reductions potential of point sources other than 

those BART-eligible sources that are specifically regulated in accordance with the requirements 

of the Regional Haze Rule. 
75

The Regional Haze Rule requires states to review progress in reaching their established RPGs 

every five years. If, in the future, it is demonstrated that the actual rate of progress is not 

meeting the established goals, Arkansas will reevaluate the need for additional control measures. 

This would require a four-factor analysis to be conducted as a means of determining which 

facilities, in addition to those already regulated under the BART Rule, would be potentially 

subject to additional control measures. 

11.4.6 Enforceability of emission limitations and control measures 

40 CFR 51.308(d)(3)(v)(F) requires the State of Arkansas to ensure that emission limitations and 

control measures used to meet RPGs are enforceable. 

The State of Arkansas has ensured that all emission limitations and control measures used to 

meet RPGs are enforceable by embodying these in State-adopted rules. Arkansas has determined 

that emission limitations or control measures other than BART are not currently required in order 

to meet the established RPGs. Appendix 11.2 is a copy of these regulations. 

List of Chapter 11 Appendices

11.1 Agricultural and Forestry Smoke Management 

11.2 Arkansas Pollution Control and Ecology Commission Regulation No. 19 – Regulations 

of the Arkansas Plan of Implementation for Air Pollution Control 
76

12. Comprehensive Periodic Implementation Plan Revisions 

The 40 CFR 51.308(f) requires a State to revise its regional haze implementation plan and submit 

a plan revision to EPA by July 31, 2018, and every ten (10) years thereafter. In accordance with 

the requirements listed in 40 CFR 51.308(f) of the federal rule for regional haze, Arkansas 

commits to revising and submitting this regional haze implementation plan by July 31, 2018, and 

every ten (10) years thereafter. 

In addition, 40 CFR 51.308(g) requires periodic reports evaluating progress towards the RPG 

established for each mandatory Class I area. In accordance with the requirements listed in 40 

CFR 51.308(g) of the federal rule for regional haze, Arkansas commits to submitting a report on 

reasonable progress to EPA every five years following the initial submittal of the SIP. The 

reasonable progress report will evaluate the progress made towards the RPG for each mandatory 

Class I area located within Arkansas and in each mandatory Class I area located outside 

Arkansas, which may be affected by emissions from within Arkansas. All requirements listed in 

51.308(g) shall be addressed in any SIP revision for reasonable progress. 

List of Chapter 12 Appendices

There are no Appendices in Chapter 12. 
77

13. Determination of the Adequacy of the Existing Plan 

Depending on the findings of the five-year progress report, Arkansas commits to taking one of 

the actions listed in 40 CFR 51.308(h). The findings of the five-year progress report will 

determine which action is appropriate and necessary. 

List of Possible Actions – 40 CFR 51.308(h) 

1) Arkansas determined that the existing SIP required no further substantive revision in 

order to achieve established goals. Arkansas provided to the Administrator a negative 

declaration that further revision of the SIP is not needed at this time> 

2) Arkansas determined that the existing SIP may be inadequate to ensure reasonable 

progress due to emissions from other states which participated in the regional planning 

process. Arkansas provided notification to the Administrator and the states that 

participated in regional planning. Arkansas collaborated with states through the regional 

planning process to address the SIP’s deficiencies. 

3) Arkansas determined that the current SIP may be inadequate to ensure reasonable 

progress due to emissions from another country. Arkansas provided notification, along 

with available information, to the Administrator. 

4) Arkansas determined that the existing SIP is inadequate to ensure reasonable progress 

due to emissions within the Arkansas, Arkansas will revise/has revised its SIP to address 

the plan’s deficiencies (State must address the deficiencies within one year.) 

List of Chapter 13 Appendices

There are no Appendices in Chapter 13. 
78

Guidance Documents

Assessment of Baseline, Natural and Current Conditions 

EPA is to develop guidance on calculating baseline and current visibility. EPA is to develop 

guidance on calculating baseline in the absence of on-site data. EPA is to develop technical 

guidance on estimating natural visibility conditions. EPA to revise the Interim Air Quality 

Policy on Wildland and Prescribed Fires which includes guidance on determining the 

contribution of fire to natural visibility conditions. States should include in the SIP “appropriate 

methods for estimating natural conditions. It is assumed that the States procedures will use these 

guidance documents to establish the Baseline, Background and Current conditions in each Class 

I Area. 

Best Available Retrofit Technology 

Controlling SO2 Emissions: A Review of Technologies, EPA Office of Research and 

Development, EPA-600/R-00-093 

Guidelines for Determining Best Available Retrofit Technology for Coal-fired Power Plants and 

Other Existing Stationary Facilities. EPA-450/3-80-009b. November 1980. This document 

addresses reasonably attributable BART not regional haze BART. However, it will be the basis 

for regional haze BART guidance being developed by EPA. The RH BART engineering 

analysis will be similar to the RA BART guidance of 1980. 

40 CFR part 51 Regional Haze Regulations; Final Rule. EPA. Federal Register Vol. 64, No 126/ 

Thursday, July 1, 1999. The preamble discusses RH BART in detail. 

Guidance for Demonstrating Attainment of Air Quality Goals for PM2.5 and Regional Haze. EPA. 

Draft 2.1, January 2, 2001. 

This document provides guidance on how to use modeled and monitored data to estimate if 

visibility goals for regional haze will be met by a proposed control strategy. 

Voluntary Emissions Reduction Program for Major Industrial Sources of Sulfur Dioxide in Nine 

Western States and a Backstop Market Trading Program. An Annex to the Report of the Grand 

Canyon Visibility Transport Commission. Western Regional Air Partnership. October 1, 2000. 

This document describes an emissions trading program and provides a model rule and draft 

memorandum of understanding between states and tribes for implementing an interagency 

emissions trading program. 

Proposed Guidelines for Best Available Retrofit Technology (BART) Determinations Under the 

Regional Haze Regulations. EPA. Draft January 12, 2001. This document, when finalized in 

2001, will provide the guidance on RH BART. It was recently proposed in the Federal Register. 

The final document will be Appendix Y of Part 51. It will address the RH BART engineering 

analysis, cumulative visibility assessment, and emission trading alternatives. 
79

Improving Air Quality with Economic Incentive Programs. EPA - 452/R-01-001. January 2001. 

This document provides guidance for economic incentive programs including emission trading 

programs that states may incorporate in their strategies for meeting air quality standards and 

addressing visibility impairment in national parks and wilderness areas. 

Long Term Strategy 

Guidance for Demonstrating Attainment of Air Quality Goals for PM2.5 and Regional Haze

(EPA, OAQPS, draft 2.1, January 2, 2001) 

Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National 

Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations (EPA-454/R-99-006, 

April 1999) 

Proposed Guidelines for Best Available Retrofit Technology (BART) Determinations Under the 

Regional Haze Regulations. This proposal will be published in the Federal Register soon. 

Monitoring Strategy and Emissions Inventory 

Visibility Monitoring Guidance document, (EPA-454/R-99-003, June 1999) 

 http://www.epa.gov/ttn/amtic/files/ambient/visible/r-99-003.pdf 

IMPROVE Particulate Monitoring Network - Procedures for Site Selection, (Crocker Nuclear 

Laboratory, University of California, February 24, 1999) 

http://www.epa.gov/ttn/amtic/files/ambient/visible/select22.pdf 

IMPROVE Particulate Monitoring Network – Standard Operating Procedures Air Quality, 

(Crocker Nuclear Laboratory, University of California, October 15, 1998) 

http://www2.nature.nps.gov/ard/vis/sop/index.html 

National Park Service Visibility Monitoring internet site, 

http://www2.nature.nps.gov/ard/vis/vishp.html

EPA Consolidated Emission Reporting Rule, (Federal Register: May 23, 2000, Volume 65, 

Number 100, Proposed Rules, Page 33268-33280.) 

http://www.epa.gov/ttn/chief/cerr/CERR_FR.pdf

Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National 

Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations (EPA-454/R-99-006, 

April 1999). http://www.epa.gov/ttn/chief/eidocs/eidocfnl.pdf

Reasonable Progress Goals 

Controlling SO2 Emissions: A Review of Technologies, EPA Office of Research and 

Development, EPA-600/R-00-093 
80

EPA Clean Air Technology Center - Control Cost Manual (5th edition) - 

http://www.epa.gov/ttn/catc/products.html

 

EPA BART guidelines (soon to be proposed) - 

http://www.epa.gov/ttn/oarpg/t1pfpr.html

EPA Guidelines for Preparing Economic Analyses - 

http://www.epa.gov/economics/ 

Guidelines for Determining Natural Background, to be developed by EPA. 

Guidelines for interpreting statutory factors, to be developed by EPA. 

Regional Haze Regulations, Final Rule, 40 CFR, Part 51, July 1, 1999. 

Weight of Evidence

Guidance for Improving Weight of Evidence Through Identification of Additional Emission 

Reductions, Not Modeled. http://www.epa.gov/scram001/guidance/guide/addwoe1h.wpd