TECHNICAL SUPPORT DOCUMENT

Louisiana Regional Haze State Implementation Plan

August 31, 2016

Submitted August 11, 2016

No material in this submittal package was designated as Confidential Business Information.

FOR FURTHER INFORMATION CONTACT:

Jennifer Huser, United States Environmental Protection Agency Region 6, Air Planning Section 

(6MM-AA), 1445 Ross Avenue, Suite 1200, Dallas, Texas 75202-2733, (214) 665-7347
I. Louisiana Regional Haze

A. Background on Regional Haze

Regional haze is visibility impairment that is produced by a multitude of sources and 

activities which are located across a broad geographic area and emit fine particulate matter 

(PM2.5) (e.g., sulfates, nitrates, organic carbon, elemental carbon, and soil dust), and their

precursors (e.g., SO2, NOx, and in some cases, ammonia (NH3) and volatile organic compounds 

(VOCs)). Fine particle precursors react in the atmosphere to form PM2.5 that impairs visibility by 

scattering and absorbing light. Visibility impairment reduces the clarity, color, and visible 

distance that one can see. PM2.5 can also cause serious health effects and mortality in humans 

and contributes to environmental effects such as acid deposition and eutrophication. 

Data from the existing visibility monitoring network, the “Interagency Monitoring of 

Protected Visual Environments” (IMPROVE) monitoring network, show that visibility 

impairment caused by air pollution occurs virtually all the time at most national parks (NPs) and 

wilderness areas (WAs). The average visual range1in many Class I areas (i.e., NPs and memorial 

parks, WAs, and international parks meeting certain size criteria) in the western United States is 

100-150 kilometers, or about one-half to two-thirds of the visual range that would exist without 

anthropogenic air pollution. In most of the eastern Class I areas of the United States, the average 

visual range is less than 30 kilometers, or about one-fifth of the visual range that would exist 

under estimated natural conditions. 64 FR 35714, at 35715 (July 1, 1999).

B. Regional Haze Requirements

The goal of the Regional Haze Rule (RHR) is to restore natural visibility conditions2 by 

2064 at the 156 Class I areas3identified in the 1977 Clean Air Act Amendments. The regional 

haze state implementation plans (SIPs) must contain measures that make “reasonable progress” 

toward this goal by reducing anthropogenic emissions that cause haze. The RHR sets out specific 

requirements for state’s initial regional haze SIPs. In particular, each plan must establish a long 

term strategy that ensures reasonable progress toward achieving natural visibility conditions in 

each Class I area affected by the emissions from sources within the state. In addition, for each 

Class I area within the state’s boundaries, the plan must establish a reasonable progress goal 

(RPG) for the first planning period that ends on July 31, 2018. The long-term strategy must 

include enforceable emission limits and other measures as necessary to achieve the RPG. 

Regional haze plans must also give specific attention to certain stationary sources that were in 

existence on August 7, 1977, but were not in operation before August 7, 1962. These sources, 

where appropriate, are required to install Best Available Retrofit Technology (BART) controls to 

 

1 Visual range is the greatest distance, in kilometers or miles, at which a dark object can be viewed against the sky.

2 40 CFR 51.301(q) defines natural conditions: “Natural conditions include naturally occurring phenomena that 

reduce visibility as measured in terms of light extinction, visual range, contrast, or coloration.”

3 Louisiana has one Class I area within its borders, namely the Breton National Wilderness Area (Breton). 
eliminate or reduce visibility impairment. More details on regional plan requirements are 

summarized in the Regional Haze Rule. 64 FR 35714.

C. Relationship of this TSD and Our Proposed Approval of the SIP Action Submitted 

by LDEQ on August 26, 2016 to Our July 3, 2012 Final Partial Approval and Partial 

Limited Disapproval of the Louisiana Regional Haze SIP

 The Act requires each state to develop plans to meet various air quality requirements, 

including protection of visibility. (CAA sections 110(a), 169A, and 169B). The plans developed 

by a state are referred to as State Implementation Plans or SIPs. A state must submit its SIPs and 

SIP revisions to EPA for approval. Once approved, a SIP is federally enforceable, that is 

enforceable by EPA and citizens under the Act. If a state fails to make a required SIP submittal 

or if we find that a state’s required submittal is incomplete or unapprovable in whole or in part, 

then we must promulgate a Federal Implementation Plan (FIP) to fill this regulatory gap within 2 

years unless we approve a SIP revision correcting the deficiencies before promulgating a FIP. 

(CAA section 110(c)(1)).

To address the first implementation period, the State of Louisiana submitted a RH SIP on

June 13, 2008. EPA acted on that submittal in two separate actions: a limited disapproval (77 FR 

33641; June 7, 2012) because the SIP relied on the Clean Air Interstate Rule (CAIR) to address 

the impact of emissions from the State’s electric generating units (EGUs); and a partial limited 

approval/partial disapproval (77 FR 39425; July 3, 2012) noting deficiencies in the SIP revision 

that did not meet the applicable requirements of the CAA and EPA’s regulations as set forth in 

sections 169A and 169B of the CAA and in 40 CFR 51.300-308. On August 11, 2016, Louisiana 

submitted a SIP revision intended to cure the deficiencies noted in our partial limited 

approval/partial disapproval concerning BART for four non-EGU sources. This TSD and our 

proposed approval provide our analysis of that submittal. However, the deficiencies stemming 

from Louisiana’s reliance on CAIR for EGU BART are not addressed by this submittal or our 

proposed action. We will address EGU BART for Louisiana in a future rulemaking. 

D. Portions of the Louisiana Regional Haze SIP Addressed by EPA and Remaining 

Items Addressed by This Action

In our July 3, 2012 final partial limited approval and partial disapproval of the June 13, 

2008 Louisiana RH SIP, we found that the following elements satisfied the federal requirements 

insofar as they do not rely on the sulfur dioxide (SO2) and nitrogen oxides (NOX) reductions 

from the Clean Air Interstate Rule (CAIR): 

 Identification of affected Class I areas; 

 Establishment of baseline, natural and current visibility conditions, including the 

Uniform Rate of Progress (URP); 

 Coordination of reasonably attributable visibility impairment (RAVI) and RH 

requirements; 
 RH monitoring strategy and other SIP requirements under Title 40 of the Code of 

Federal Regulations (denoted as 40 CFR), Part 51.308(d)(4); 

 Louisiana’s commitment to submit periodic RH SIP revisions and periodic 

progress reports describing progress towards the state’s Reasonable Progress 

Goals (RPGs); 

 Louisiana’s commitment to make a determination of the adequacy of the existing 

SIP at the time a progress report is submitted and;

 Louisiana’s coordination with the Federal Land Managers (FLMs).

We also found that certain elements of the Best Available Retrofit Technology (BART) 

evaluations and determinations were not fully adequate to meet the federal regulations. For the 

BART Sources, the following deficiencies were noted in the BART analyses:

 SO2, NOX, and PM BART for Mosaic;

 SO2, NOX, and PM BART for certain BART-Subject Units at the Phillips 66 

Company Alliance Refinery (formerly ConocoPhillips);

 SO2 BART for EcoServices Units 1 and 2; and

 SO2 and NOX BART for Sid Richardson

In addition to finding the listed BART analyses deficient, we also found that the

submittal did not include enforceable emissions limitations or compliance schedules within the

SIP for those sources subject to BART. 

The purpose of this TSD and the proposed Federal Register notice associated with this 

TSD is to supersede the portions of the previous actions addressing non-EGU BART that were 

found deficient in the partial limited approval and partial disapproval action (77 FR 39425). This 

TSD contains our evaluation of the revised Louisiana RH SIP submittal provided by LDEQ on 

August 11, 2016. This TSD is not meant to be a complete rationale for our decision. It merely 

provides additional information for some of the technical aspects of the basis for this action 

when needed. In some of the non-technical areas, our Federal Register (FR) notice provides more 

detail than does the TSD. The TSD also refers the reader to the specific portions of the Louisiana 

RH SIP submittal that we relied upon for our analysis of particular portions of 40 CFR 51.308. 

Throughout this document, we often use language such as, “we find” or other similar 

phrases that on the surface would suggest a final determination has been made. However, all 

aspects of our TSD should be considered to be part of our proposal and are subject to change 

based on comments and other information we may receive during our public comment period.

II. Best Available Retrofit Technology (BART)

A. Identification of BART Eligible Sources and Subject to BART Sources

States are required to identify all the BART-eligible sources within their boundaries by 

utilizing the three eligibility criteria in the BART Guidelines (70 FR 39104, at 39157-58) and the 

Regional Haze regulations (40 CFR 51.301): (1) One or more emission units at the facility fit 
within one of the 26 categories listed in the BART Guidelines; (2) the emission unit(s) began 

operation on or after August 6, 1962, and the unit was in existence on August 6, 1977; and (3) 

the potential emissions of any visibility-impairing pollutant from subject units are 250 tons or 

more per year. Sources that meet these three criteria are considered BART-eligible. Once a list of 

the BART-eligible sources within a state has been compiled, states must determine whether to 

make BART determinations for all of them or to consider exempting some of them from BART 

because they may not reasonably be anticipated to cause or contribute to any visibility 

impairment in a Class I area. The BART Guidelines present several options that rely on 

modeling analyses and/or emissions analysis approaches to determine if a source may reasonably 

be anticipated to cause or contribute to visibility impairment in a Class I area. A source that may 

not be reasonably anticipated to cause or contribute to any visibility impairment in a Class I area 

is not “subject to BART,” and for such sources, a state need not apply the five statutory factors to 

make a BART determination.

In determining BART for sources that are subject to BART, the state must consider the 

five statutory factors in section 169A of the CAA: (1) the costs of compliance; (2) the energy and 

non-air quality environmental impacts of compliance; (3) any existing pollution control 

technology in use at the source; (4) the remaining useful life of the source; and (5) the degree of 

improvement in visibility which may reasonably be anticipated to result from the use of such 

technology. See also 40 CFR 51.308(e)(1)(ii)(A). 

The BART Guidelines (70 FR 39164, July 6, 2005) describe the BART analysis as 

consisting of the following five steps:

 Step 1: Identify All Available Retrofit Control Technologies; 

 Step 2: Eliminate Technically Infeasible Options;

 Step 3: Evaluate Control Effectiveness of Remaining Control Technologies;

 Step 4: Evaluate Impacts and Document the Results; and

 Step 5: Evaluate Visibility Impacts.

As mentioned previously, Louisiana submitted the 2008 RH SIP to address the first 

regional haze implementation period on June 13, 2008. On July 3, 2012, the EPA finalized a 

partial limited approval and partial disapproval of the Louisiana RH SIP (77 FR at 39425). This 

included a disapproval of portions of the BART determinations made by Louisiana. Following 

EPA’s partial limited approval and partial disapproval action, the Louisiana Department of 

Environmental Quality (LDEQ) worked closely with the BART facilities and with EPA Region 6 

to revise the Regional Haze SIP. LDEQ submitted a revised Louisiana RH SIP on August 11, 

2016. 

1. Mosaic Fertilizer Uncle Sam Plant 

Mosaic Fertilizer, LLC owns and operates the Uncle Sam Plant in St. James Parish, 

Louisiana and produces phosphoric acid and sulfuric acid. In the original LA RH submittal, 

Louisiana determined that Mosaic was not subject to BART based on modeling future controls

that were to be installed on the A Train Sulfuric Acid Stack.
In our July 3, 2012 final action, we approved Louisiana’s identification of BART-eligible 

sources and determination of sources subject to BART, with the exception of the State’s 

determination that the Mosaic Fertilizer Uncle Sam Plant was exempted from BART. Our basis 

and analyses for our disapproval of Louisiana’s determination that Mosaic was exempted from 

BART is found in our February 28, 2012 proposed rulemaking, July 3, 2012 final rulemaking, 

and the associated TSDs.4 LDEQ agreed that Mosaic should have been identified as subject to 

BART, and therefore required to conduct a five factor BART analysis.

Mosaic conducted and submitted an initial BART analysis to LDEQ on July 17, 2015. 

During our review of the initial BART analysis, several items were noted as failing to follow the 

BART Guidelines. In response to an EPA issued CAA Section 114 Information Request5, 

Mosaic corrected the deficiencies and submitted to EPA and LDEQ a revised BART analysis.6 

Mosaic used the three step process in the Regional Haze Rule to determine if the units are 

BART-eligible. A stationary source is evaluated to determine whether it contains any emissions 

units in one or more of the 26 relevant source categories. If the stationary source includes an 

emissions unit in one or more of these source categories, then the next step requires the source to 

determine whether each of these emissions units began operation after August 7, 1962 and was in 

existence on August 7, 1977. The last step is to evaluate the current potential to emit emission 

rate of each visibility-impairing pollutant (NOx, PM, and SO2) separately to determine whether 

the total potential to emit emission rate from these emissions units equals 250 tpy or more for 

any visibility-impairing pollutant. Using this process, Mosaic identified the following units as 

subject to BART:

 A Train Single Absorption H2SO4 Plant

 A Train Startup Burner

 A Train Fugitive Emissions

 D Train Double Absorption H2SO4 Plant

 D Train Startup Burner

 D Train Fugitive Emissions

 Phosphate Rock Transfer, Storage, and Handling Operations

 Sulfur Unloading Pit

 Sulfur Storage Tank A

 Sulfur Storage Tank B

 Dock Fugitive Emissions

 No. 1 Packaged Steam Boiler

 No. 2 Packaged Steam Boiler

Mosaic also concluded that the emissions units comprising the plant’s E Train are not BARTeligible because they were not “in existence” on August 7, 1977. Construction of the E Train 

began in 1991, as indicated by the January 14, 1991 preconstruction air permit application 

 

4 77 FR 11839 and 77 FR 39425.

5 CAA Section 114 Letter from Ms. Wren Stenger to Mr. David Oubre dated September 1, 2015. A copy of this 

letter and its attachments can be found in the docket for this proposed rulemaking.

6 CAA Section 114 Response letter from Mr. David Oubre to Ms. Wren Stenger dated September 30, 2015. A copy 

of this letter and its attachments can be found in the docket for this proposed rulemaking.
submitted to LDEQ, along with the August 16, 1991 air permit (Permit No. 2091) issued by 

LDEQ authorizing its construction.7

On October 5, 2009, Mosaic entered into a Consent Decree with the United States and 

Louisiana Department of Environmental Quality to address alleged violations of the Clean Air 

Act.8 Requirements of the settlement included the installation of controls at the Uncle Sam plant. 

Those controls included:

 A scrubber system installed on the A Train in February 2011 reducing SO2

emissions by 9,460 tons per year; and

 Improving the dual absorption system on the D Train in July-September 2001 

resulting in 576 tons per year reduction of SO2 emissions.

In conducting the five factor BART analysis, Mosaic concluded and LDEQ agreed that 

the existing operations and emissions control technologies are consistent with the future case 

modeled in the BART analysis. LDEQ further concluded that additional emission controls would 

not be cost effective and would not provide sufficient visibility benefits to be warranted. Based 

on these conclusions, LDEQ concluded that the current controls, operating conditions, and 

emissions limits satisfy BART. LDEQ’s review is in Section II of the SIP submittal. EPA has 

reviewed and agrees with LDEQ’s conclusion that the current controls and emissions limits 

represent BART for SO2, NOx, and PM. 

Section 51.308(e) requires that Louisiana’s Regional Haze SIP include emissions 

limitations representing BART. Louisiana incorporated the emission limits that constitute BART

for SO2, NOx, and PM in an Administrative Order on Consent (AOC) No. AE-AOC-14-00274A. 

The revised determination and AOC establish enforceable and permanent emission limits and 

operating conditions.

2. Phillips 66 Alliance Refinery (formerly ConocoPhillips Co.)

The Phillips 66 Company (Phillips 66) operates a refinery near Belle Chasse, Louisiana 

and is a subject to BART source. Phillips 66 entered into a Consent Decree (CD) with the United 

States of America and the State of Louisiana on December 5, 2005, as part of the National 

Refinery Initiative.9 As a part of the settlement, Phillips 66 installed controls on the fluidized 

catalytic cracker, the process refinery flares, and the crude unit heater.

In our July 3, 2012 final action, we determined that LDEQ did not provide a complete 

BART evaluation for the units covered by the CD. LDEQ did not analyze the controls using the 

five step process required by 40 CFR 51.308(e). Also, no emission limits for BART for these 

units were included in the LA RH SIP. Several other units were determined to be subject to 

BART at the Phillips 66 Alliance Refinery. For the cooling water tower and gas-fired heaters, 

 

7 Permit Application submitted by Agrico to LDEQ on January 14, 1991, and Permit No. 2091 issued to Agrico on 

August 16, 1991. Agrico was the predecessor in ownership to Mosaic Fertilizer, LLC of the Uncle Sam Plant. A 

copy of these documents is provided in the LDEQ SIP submittal, Exhibit 1 of Attachment 1 (BART Analysis)

8 Civil Action No. 09-6662. A copy of this CD is available in the docket for this proposed rulemaking. 

9 Civil Action No. H-05-0285. A copy of this CD is available in the docket for this rulemaking.
we approved the BART analysis provided for PM (cooling water tower), and NOX (gas-fired 

heaters) and agreed that no additional controls were necessary. We also approved the BART 

analysis and conclusions for emissions of PM, SO2, and NOX for the Product Dock No. 1 MVR 

Loading, the Product Dock No. 2 MVR Loading, and Coke Transfer and Storage. 

On January 27, 2014, Phillips 66 provided a revised BART analysis to LDEQ to include 

the five step analysis of for the fluidized catalytic cracker (FCCU), the process refinery flares, 

and the crude unit heater. In this BART analysis, Phillips 66 provided information including 

emission reductions resulting from the installation of controls mandated in the Consent Decree. 

Controls installed include:

 A wet gas scrubber (WGS) installed on the FCCU in 2009 that reduced SO2

emissions by 2500 tpy and PM emissions by 220 tpy. Selective Catalytic 

Reduction (SCR) installed in February 2015 that reduced NOx emissions by 760 

tpy.

 SCR was installed on the crude unit heater in 2009 that reduced NOx emissions 

by 700 tpy; NOx Continuous Emissions Monitoring was also installed on this 

unit;

 Flare gas recovery was installed for the process refinery flares in 2011 that 

reduced NOx emissions by 16 tpy and SO2 emissions by 330 tpy;

 The low pressure and high pressure flares meet New Source Performance 

Standards (NSPS) Subpart J requirements (EQT 308F-D-1 and 309-D-2);

 The CO Boilers meet NSPS J requirements (EQT 301-B-2A and 301-B-2B);

 Crude Charge Heater meets NSPS Subpart J requirements (EQT 191-H-1).

In addition to controls required by the CD, the Crude Charge Heater is controlled by SCR 

and amine scrubbing for NOx and SO2. In a review of controls found at refineries around the 

United States, Phillips 66 concluded that there are no appropriate add-on controls to reduce PM 

emissions, and therefore good combustion techniques employed by Phillips 66 constitute BART. 

With respect to SO2, the refinery is required by CD to comply with fuel gas H2S limits mandated 

by NSPS Subpart J for Petroleum Refineries through the use of a fuel gas amine scrubbing 

system that applies to all heaters in the refinery, and represents the most stringent available SO2

control system. Therefore, for SO2 and PM, the controls implemented as required by the CD, 

represent the top level of control and therefore a detailed BART analysis was not necessary. The 

Crude Charge Heater pollutants are controlled to the following levels:

 SO2: <=0.1 grains H2S/dscf (or 162 ppmvd H2S) in refinery fuel on a 3-hr rolling 

average basis. This control level is achieved by amine scrubbing of the Phillips 66 

refinery fuel gas on a facility-wide basis for all process heaters;

 PM: 0.00745 lb PM/MMBtu of refinery fuel gas fired on an annual average basis 

using good combustion techniques based on AP-42 Table 1.4.2 (1998). Consistent 

with all other refinery fuel gas heaters operated in the U.S., there are no add-on 

controls for PM emissions; and

 NOx: 0.0185 lb NOx/MMBtu of refinery fuel gas fired on a 365 day rolling 

average basis, controlled using a SCR control system.

In evaluating BART at the FCCU Regenerator Vent, Phillips 66 determined that SO2 was 

the major contributor to visibility impairment. In 2003, SO2 emissions from the FCCU 

Regenerator Vent were 2,678.6 tpy. In 2011, SO2 emissions from FCCU Regenerator Vent were 
103 tpy. This represents an actual pre-BART-to-post-BART SO2 annual emission reduction of 

2,575.6 tpy. It also reflects a greater than 96% reduction in SO2 emissions, based on an analysis 

of two years of data. Upon review of the RACT/BACT/LAER Clearinghouse for controls 

available on an FCCU, Phillips 66 determined, and LDEQ agreed, that the SCR and WGS 

controls for NOx, SO2, and PM are among the most stringent controls available for the FCCU 

Regeneration Vent Controls implemented as requirements of the CD represent BART and will 

control emissions of the BART pollutants to the following levels:

 SO2: <=25 ppmvd SO2 on a 365-day rolling average basis @ 0% O2; also, <= 50 

ppmvd SO2 on a 7 day rolling average basis @ 0% O2;

 PM: <=0.5 lb PM/1000 lb of coke burn on a 3-hr average basis; and 

 NOx: <=20 ppmvd NOx on a 365-day rolling average basis @ 0% O2; also, <=40 

ppmvd NOx on a 7-day rolling average basis @ 0% O2.

In evaluating BART for the Low Pressure and High Pressure Flares, Phillips 66 

determined that there are currently no technically feasible add-on air emission controls systems 

for elevated candle-type flares. Current control technology incorporates the following work 

practices to reduce flare emissions and represents BART: 

 Flare Gas Recovery System used to reduce the amount of flare gas combusted in 

the flare; and

 Amine scrubbing of the recovered flare gas to reduce the concentration of H2S 

prior to the gas stream being routed to the refinery fuel gas system.

LDEQ’s review is in Section II of the SIP. EPA has reviewed and agrees with LDEQ’s 

conclusion that these controls represent BART for SO2, NOx and PM. Further, EPA agrees that 

with the control strategies selected, the subject-to-BART units at Phillips 66 represent among the 

most stringent or “top level” controls available and meet the BART requirements at 40 CFR 51 

Appendix Y.OV.D.1.9.

Section 51.308(e) requires that Louisiana’s Regional Haze SIP include emissions 

limitations representing BART. Louisiana included the revised BART determination and an 

Administrative Order on Consent (AOC) No. AE-AOC-14-00211A. The revised determination 

and AOC establish enforceable and permanent emission limits and operating conditions.

3. Eco-Services Operations, LLC

The Eco-Services Operations, LLC facility is a sulfuric acid plant located in Baton 

Rouge, Louisiana. Eco-Services was previously known as Rhodia and Solvay. The plant 

produces sulfuric acid by using two sulfuric acid production trains, Unit 1 and Unit 2. On April 

27, 2007, Eco-Services entered into a Consent Decree with the United States of America and the 

State of Louisiana to resolve alleged violations of the Clean Air Act, including New Source 

Review, Prevention of Significant Deterioration, and the New Source Performance Standard for 

Sulfuric Acid Plants.

10

 

10Civil Action No. 2:07CV134WL. A copy of this CD is available in the docket for this proposed rulemaking.
In our July 3, 2013 final action, we approved Louisiana’s BART evaluation. Our basis 

and analyses for our approval of Louisiana’s BART determination for Eco-Services is found in 

our February 28, 2012 proposed rulemaking, July 3, 2012 final rulemaking, and the associated 

TSDs.11 However, we determined that the SIP failed to include the SO2 emission limits for the 

subject-to-BART unit into the SIP. Section 51.308(e) requires that Louisiana’s Regional Haze 

SIP include emissions limitations representing BART. Louisiana included an Administrative 

Order on Consent (AOC) No. AE-AOC-14- 00957, which contained the applicable emissions 

limitations for BART. The revised determination and AOC establish enforceable and permanent 

emission limits and operating conditions.

4. Sid Richardson Carbon Company

The Sid Richardson Carbon Company Addis Plant was determined to be a subject to 

BART source in Louisiana’s original Regional Haze SIP revision.12 It is located in West Baton 

Rouge Parish, Louisiana. In our July 3, 2013 final action, we approved Louisiana’s 

determination that the high efficiency fabric filters already in use at the facility are BART for 

PM. However, we determined that there was not sufficient information in the record to support 

the BART analysis conclusions for NOx and SO2.

In response to our action, Sid Richardson conducted updated modeling using the same 

emission parameters and approved updated EPA modeling guidance. The revised protocol was 

submitted via email to EPA in July 2013, and was approved by EPA on October 17, 2013.

13 The 

modeling conducted in 2013 in response to our action used the methods and guidance of FLAG 

2010 and the 8/31/2009 Memorandum “Clarification on EPA-FLM Recommended Settings for 

CALMET”, along with the most recent versions of the CALPUFF system of programs. The 

2007 analysis modeling used methods and guidance from FLAG 2000, along with older versions 

of the CALPUFF system of programs that were current in 2007. The FLAG 2010 guidance 

document includes new IMPROVE equations to calculate visibility impacts. The FLAG 

2010/IMPROVE equations include new higher background concentrations and relative humidity 

adjustment factors for the hygroscopic effects for each of the major species that account for most 

of the visibility effects. Higher natural background concentrations and higher relative humidity 

adjustment factors for the 2013 analysis resulted in higher background visibility than the data 

and methods used in the 2007 analysis. The visibility impacts from the Addis Plant, when 

included with the updated natural background visibility, results in a lower delta-deciview impact 

because of the higher natural background visibility. 

There were also significant changes in the CALMET parameters that impacted the 

modeling results. While the 2007 analysis relied on values determined by the modeler and 

approved in the protocol, the 2013 analysis followed the 8/31/2009 Memorandum for CALMET 

 

11 77 FR 11839 and 77 FR 39425.

12 The State’s revised SIP submittal indicates that Sid Richardson’s Addis Plant is a subject-to-BART source, but 

this is an error. This section of the SIP submittal also refers to Louisiana’s BART threshold as 0.05dv, but this is a 

typo. Louisiana’s SIP approved BART threshold is 0.5dv. Both of these errors are harmless because, as explained, 

Louisiana’s SIP revision adequately demonstrates that the Addis Plant is not subject to BART based on updated 

modeling information. 

13 Emails to and from Ellen Belk and Sid Richardson re modeling protocol
settings. For example, the value RMAX1, which sets the distance that surface observations 

modify the Step 1 Wind Fields to develop the Step 2 Wind Fields, for 2007 was set at 30 km 

while the 2013 protocol set the RMAX1 at 100 km. The smaller value used in the 2007 analysis 

means that the surface observations did not influence the wind fields beyond 30 km, whereas the 

2013 analysis influenced the wind fields out to a much greater distance. The change in the 

CALMET three-dimensional Meteorological Grid changed the overall visibility impact results.

The emission rates used in the 2007 modeling analysis were based on the highest annual 

emission rates from the period of 2001-2003, which occurred in 2002. The daily emission rates 

were back-calculated from these annual emission rates. These daily rates did not necessarily 

represent the worst-case scenario emission rates because they were based on annual averages. 

The emission rates used in the 2013 modeling analysis represented the worst-case scenario 

emission rates because they were derived from the permitted lbs/hr limits. The emission rates 

used in the 2013 modeling analysis were greater than those used in the 2007 modeling analysis.

EPA reviewed and approved the revised modeling protocol and results. The highest 98th

percentile for the 2001-2003 period was 0.344 delta-deciviews and the highest 98th percentile for 

the highest year was 0.397 delta-deciviews for the year 2002. These modeling results 

demonstrate that the Sid Richardson Carbon Company Addis Plant has less than a 0.5 deciview 

impact on Breton island and therefore EPA agrees with LDEQ’s conclusion that this source is 

not subject to BART.