# Appendix L

Mississippi BART DeterminationsAppendix L – Mississippi BART Determinations

• Introduction to Appendix L

• Contribution Threshold

• Tabular Summary of Appendix

• L.1 – Entergy Mississippi Incorporated

• L.2 – Georgia Pacific Corporation – Monticello

• L.3 – Greenwood Utilities – Henderson

• L.4 – Holcim (US) Incorporated

• L.5 – International Paper Company – Vicksburg

• L.6 – Mississippi Power Company

• L.7 – Pursue Energy Corporation – Thomasville

• L.8 – South Mississippi El ectric Power Association

• L.9 – Terra Mississi ppi Nitrogen, Inc.

• L.10 – Chevron Pascagoula Refinery

• L.11 – Mississippi Phosphates Corporation

• L.12 – IMPROVE Equation Rationale

• L.13 – BART Modeling ProtocolAppendix L: Mississippi BART Determinations

The 1999 regional haze rule include s the BART requirement, and directs States to include BART in their regional haze SIPs. On July 6, 2005, USEPA published a revised final rule, including Appendix Y to 40 CFR Part 51, the Guidelines for BART Determinations Under the Regional Haze Rule (hereinafter referred to as the “BART Guidelines”) that provides direction to states on determining which of these sources should be subject to BART, and how to determine BART for each source.

A BART-eligible source is one which has the potential to emit 250 t ons or more of a visibility-impairing air pollutant, was put in place between August 7, 1962 and August 7, 1977, and whose operations fall within one or more of 26 specifically listed source categories. Under the CAA, BART is required for any BART-eligible source that a State determines ‘‘emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of vi sibility in any such area.’’

For those sources subject to BART, Section 169A(g)(7) of the CAA requires that States must consider the following factors in ma king BART determinati ons: (1) the costs of compliance, (2) the energy and non-air quality environmental impacts of compliance, (3) any existing pollution control t echnology in use at the source , (4) the remaining useful life of the source, and (5) th e degree of improvement in vi sibility which may reasonably be anticipated to result from th e use of such technology.

Appendix L follows the BART determination pr ocess for all BART eligible sources in Mississippi. Although Missi ssippi does not have a Class I area, some of its sources affect Class I areas in neighboring states. The follo wing table lists the BA RT eligible sources, the Class I area they affected, their visibility impact and the emissions modeled. As seen in this table Mississippi had fifteen BART -eligible sources, but only two, Chevron Refinery and Mississippi Phosphates had a vi sibility impact great enough to be BART subject.

BART Eligible Source City Class I area SO2 tpy NOx tpy PM10 tpy

Holcim Artesia 148 Sipsey 5593 3390 95 0.34 Pursue Energy Thomasville 257 Breton 7761 0 0 0.17 Entergy MS -

Baxter Wilson Vicksburg 320 Breton 0 0 10805 0.35 Entergy MS -

Gerald Andrus Greenville 290 Caney Creek 0 0 6868 0.27

MS Power - Chevron Pascagoula 48 Breton 0 0 39 0.02

MS Power - Daniel Escatawpa 61 Breton 0 0 540 0.23

MS Power - Watson Gulfport 45 Breton 0 0 1834 0.42 International Paper Co - Vicksburg Redwood 328 Breton 1798 1270 1634 0.32 Georgia-Pacific Corp. Monticello 209 Breton 3932 3577 2412 0.33

SMEPA - Moselle Moselle 169 Breton n/a n/a n/a n/a

SMEPA - R D Morrow Purvis 138 Breton n/a n/a n/a n/a Terra MS Nitrogen Inc Yazoo City 308 Sipsey 1 617 25 n/a

Greenwood Utilities Henderson 281 Sipsey 2030 260 254 0.22 Mississippi Phosphates Pascagoula 52 Breton 2409 22 196 0.81 Chevron Refinery Pascagoula 48 Breton 13815 6482 819 3.89 Modeled Emissions: 24hr Average Maximum Actual Dist. from

Class I area Visibility Impact

Delta DeciviewAlso included in this appendix in secti on L.12 is the methodology and rationale behind the new IMPROVE equation which was develope d to include the effects of coastal sea salt and site-specific Rayleigh scattering on light extinction. The BART modeling protocol used by VISTAS’ BART eligible sources to configure CALPUFF and its post processors can be found in section L.13. The tabular summary of Appendix L that includes the version(s) of the IMPROVE e quation used, the resulting difference in visibility impact, whether a BART determin ation was required, the version of CALPUFF and its components used and who conducted the modeling is f ound at the end of Appendix L.Contribution Threshold

Determining whether a source causes or contributes to visibility impairment is one step in the BART review process. The Guidelines for BART Determinations Under the Regional

Haze Rule 1 state that “A single source that is re sponsible for a 1.0 deciview change or

more should be considered to ‘cause’ visi bility impairment.” The guideline document also states that “the appropr iate threshold for determining whether a source ‘contributes to visibility impairment’ ma y reasonably differ across states,” but, “As a general matter, any threshold that you use for determining wh ether a source ‘contributes’ to visibility impairment should not be higher than 0.5 decivi ews.” The rationale for these instructions is provided in the preamble to the BART guidance in the statement, “If ‘causing’ visibility impairment means causing a humanly perceptible change in visibility in virtually all situations ( i.e. a 1.0 deciview change), then ‘contributing’ to visibility impairment must mean having some lesser im pact on the conditions affecting visibility

that need not rise to th e level of human perception.” 2 The guidance document itself also states that, “States remain free to use a th reshold lower than 0.5 deciviews if they

conclude that the location of a large number of BART-eligib le sources within the State and in proximity to a Class I area justify this approach.”

The EPA’s documents strive to set these thresholds in the context of the human perception of visibility change. As noted above, the EPA considers a 1.0-deciview change in visibility to be humanly perceptible “in virtually all situations.” Also, the preamble to the BART guidance 3 cites an analysis in an a ppendix of a NAPAP (National Acid Precipitation Assessment Program) repor t, which asserts that “changes in light extinction of 5 percent will evoke just noticeable changes in most landscapes.” 4 (A 5% change is approximately 0.5 dv.) But, as not ed above, the preamble also states that perceptibility is not a prerequisite for choos ing a contribution threshold. Putting all this together, it appears that “causing” visi bility impairment me ans having a humanly perceptible impact (for which EPA considers the practical threshold to be 1.0 dv) while “contributing” to visibility impairment m eans having a smaller impact (for which EPA

considers the threshold to be 0.5 dv or some smaller value) that may or may not be perceptible.

The EPA states that a contri bution threshold of less than 0.5 dv impact per source is appropriate when multiple sources contribute, in order to limit the combined effect of these sources. As an example, EPA makes the point that if there were 100 sources, each affecting visibility by 0.1 dv (presumably an imperceptible amount), their total impact would be 10 dv (which can be expected to be quite perceptible). 5 The point remains that

1 40 CFR 51, Appendix Y, Section III.A.1

2 70 FR 39120. Footnote 31

3 70 FR 39119. Footnote 28

4 “The Quadratic Detection Model” by W. Ma lm. Appendix D in Acidic Deposition: State of Science and Technology, Report 24, Visibility: Existing and Historical Conditions -- Causes and Effects. National Acid Precipitation A ssessment Program, Washington, DC. 1990.

5 70 FR 39121. 1st columnmultiple sources can cause a larger impact than a single one. For BART purposes, visibility impacts are calculated as 24-hr averag es of 1-hr plume impacts, so if the plumes from the various sources each impact the point of interest at some time during a 24-hr period (not necessarily all at the same hou r) then the 24-hr average will reflect their combined impact.

Mississippi has a limited number (fifteen total) of sources that are BART eligible which are distributed throughout the state and impact different Class 1 areas. Therefore, MS DEQ has concluded that the EPA suggest ed contribution threshold of 0.5 dv is appropriate in this situation since there are a limited number of sources that impact the various Class I areas. Surrounding states with Class 1 areas have also adopted the 0.5 dv

threshold.Tabular Summary of Appendix LBART Source Mill/Plant City County StateBart CategorydescriptionBARTcategoryClass I areasimpactedDist. fromClass Iarea (km)IMPROVE Eqnusedold v new@Maximpact% diffinIMPROBARTDeterminationSO2 tpy NOx tpy PM10 tpyCALMETver/dateCALPOSTver/dateCALPUFFver/datePOSTUTILver/dateVisibility ImpactDelta DeciviewModeler:VISTAS/Consultant/companyHolcim FacilityArtesia Lowndes MSPortland cementplant 4SipseyWilderness Area 148old n/a n/a Eligible 5593 3390 95 5.726 5.6393 5.756 not used 0.34 RTPPursue EnergyThomasvilleThomasville Rankin MS Gas sulfur recovery 15Breton NationalWildlife Refuge 257old n/a n/a Eligible 7761 0 05.724(04/14/06)5.6393(02/02/06)5.754(02/02/06)1.52(02/06/06)0.17 TrinityEntergy MS Inc.BaxterWilson Vicksburg Warren MSFossil fuel firedsteam electric plant1Breton NationalWildlife Refuge 320old n/a n/a Eligible 0 0 10805 5.726 5.6393 5.756 1.52 0.4 ENSREntergy MS Inc.GeraldAndrus Greeneville Washington MSFossil fuel firedsteam electric plant1Caney CreekWilderness Area 290old n/a n/a Eligible 0 0 6868 5.726 5.6393 5.756 1.52 0.3 ENSRMS PowerChevron Pascagoula Jackson MSFossil fuel firedsteam electric plant1Breton NationalWildlife Refuge 48new 0.03 to 0.02 33.33% Eligible 0 0 39 5.7 5.6393 5.754 1.52 0.02SCS/ENSRMS PowerDaniel Escatawpa Jackson MSFossil fuel firedsteam electric plant1Breton NationalWildlife Refuge 61new 0.29 to 0.23 21.69% Eligible 0 0 540 5.7 5.6393 5.754 1.52 0.23SCS/ENSRMS PowerWatson Gulfport HarrisonMSFossil fuel firedsteam electric plant1Breton NationalWildlife Refuge 45new 0.52 to 0.42 19.23% Eligible 0 0 1834 5.7 5.6393 5.754 1.52 0.42SCS/ENSRInternational PaperVicksburg Redwood Warren MSKraft pulp mill3Breton NationalWildlife Refuge328 old n/a n/a Eligible 1798 1270 1634 5.723 5.6393 5.754 1.52 0.32 TRCGeorgia-PacificMonticello LawrenceMS Kraft pulp mill3Breton NationalWildlife Refuge209 old n/a n/a Eligible 3932 3577 2412 5.7265.63935.756 not used 0.33 GA PacificSouth MS ElectricPowerMoselleMoselle Jones MSFossil fuel firedsteam electric plant1Breton NationalWildlife Refuge 169old n/a n/a Eligible n/a n/a 84* n/a n/a n/a n/a n/a n/aSouth MS ElectricPowerR D MorrowPurvis Lamar MSFossil fuel firedsteam electric plant1Breton NationalWildlife Refuge 138old n/a n/a Eligible n/a n/a 64* n/a n/a n/a n/a n/a n/aTerra MS Nitrogen IncYazoo City Yazoo MSFossil fuel firedsteam electric plant1SipseyWilderness Area 308old n/a n/a Eligible 1* 617* 25* n/a n/a n/a n/a n/a n/aGreenwood UtilitiesHendersonGreenwood Henderson MSFossil fuel firedsteam electric plant1SipseyWilderness Area 281old n/a n/a Eligible 2030 260 254 5.723 5.6393 5.754 1.52 0.22 TRCMississippiPhosphatesPascagoula Jackson MSChemical processplant 21Breton NationalWildlife Refuge 52old n/a n/a Subject 2409 22 1965.724(04/14/06)5.6393(02/02/06)5.756(07/25/06)1.52(04/12/06)0.81 TrinityChevronPascagoula Jackson MS Petroleum Refinery11Breton NationalWildlife Refuge 48old n/a n/a Subject 13815 6482 819 5.726 5.6393 5.756 1.52 3.89 ENSR* - Represent potential emissions of BART eligible units.Models used in BART modelingModeled Emissions: 24hrAverage Maximum Actual