1



# Technical Support Document for

South Carolina Regional Haze SIP Submittal

January 2012

U.S. EPA

– Region 4 Atlanta, GA2 

### Technical Support Document (TSD) for South Carolina Regional Haze SIP Submittal

Table of Contents

I. Background

II. Summary of EPA’s Action

III. Evaluation of Regional Haze SIP Submittal

A. Identification of Areas

B. Reasonable Progress Goals (RPGs) Development

1. Calculations of Baseline Visibility Conditions

2. Calculations of Natural Visibility Conditions

3. Uniform Rate of Progress (UROP or “Glidepath”)

for Reasonable Progress

C. Long

- Term Strategy (LTS)

1. Technical Basis for Strategy

2. Identification of Sources and Factors to be Considered for Reasonable Progress

3. Source or Source Category Specific Analyses for Reasonable Progress

4. Enforceab ility of Reasonable Progress Measures

D. Best Available Retrofit Technology (BART) Requirements

1. Identification of all BART

- Eligible Sources

2. Modeling or other Demonstrations for BART Exempt Sources

3. Identification of Sources Addressed by Clean Air

Interstate Ru le (CAIR)

4. Source Specific BART Determinations

5. Enforceability of BART

E. Coordination of Regional Haze and Reasonably Attributable Visibility Impairment (RAVI) Requirements

F. Monitoring Strategy and Other Implementation Requirements

G. Emission Inventory

IV. Conclusion s

_____________________________________________________________________ Note : Italicized text in this document that appears under the “State Regional Haze Submittal” headings are excerpts from relevant portions of the South Carolina regional

haze submitta l as cited. Figure and table citations under these headings reflect the actual references as listed in the State‟s SIP submittal. Page numbers refer to the SIP Narrative, unless otherwise specified.3 

### TSD for South Carolina Regional Haze SIP Submittal

I. Background

In Section 169A of the 1977 Amendments to the Clean Air Act (CAA), Congress set forth a program for protecting visibility in Federal Class I areas which calls for the “prevention of any future, and the remedying of any existing, impairment of v isibility in mandatory Federal Class I areas which impairment results from manmade air pollution.” Congress adopted the visibility provisions to protect visibility in 156 Federal Class I areas, which include certain national parks, memorial parks, and wild erness areas over a certain size, and all international parks. These areas are defined at 40 CFR 81.400, and listed by s tate at 40 CFR 81.401

- 81.437. On December 2, 1980, EPA promulgated regulations to address visibility impairment that is “reasonably at tributable” to a single source or small group of sources (45 FR 80084)

. These regulations represented the first phase in addressing visibility impairment and deferred action on regional haze that emanates from a variety of sources until monitoring, modeli ng and scientific knowledge about the relationships between pollutants and visibility impairment improved.

In the 1990 Amendments to the CAA, Congress added Section 169B and called on EPA

to issue r egional h aze rules. The Regional Haze Rule (RHR) that EP A promulgated on July 1, 1999 (64 FR 35713) revised the existing visibility regulations to integrate provisions addressing regional haze visibility impairment and establish a comprehensive visibility protection program for Federal Class I areas. States ar e required to submit state implementation plans (SIPs) to EPA that set out each state‟s plan for complying with the RHR, including consultation and coordination with other states and with Federal Land Managers (FLMs). States must submit a regional haze SI P to EPA within three years after the date of designation of areas under the National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM 2.5 ). EPA promulgated PM 2.5 designations on December 17, 2004, and thus, regional haze SIPs were to b e submitted to EPA by December 17, 2007, which is also specified at 40 CFR 51.308(b).

The RHR addressed the combined visibility effects of various pollution sources over a wide geographic region. Consequently, all 50 states, including those without Class I areas, Washington, D.C., and the Virgin Islands, are required to submit r egional h aze SIPs. 40 CFR 51.300(b)(3). The US EPA designated five Regional Planning Organizations (RPOs) to assist with the coordination and cooperation needed to address

the vi sibility issue. The RPO that makes up the southeastern portion of the contiguous United States is known as VISTAS (Visibility Improvement

– State and Tribal Association of the Southeast). VISTAS members include: the Eastern Band of the Cherokee Indians, other Federally Recognized Tribes and Local Air Programs within the geographic area, and the following states: Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, and West Virginia. The

State of South Caro lina through the South Carolina Department of Health and Environmental Control (SC DHEC ) chose to participate in VISTAS to develop the technical analyses needed to fulfill the requirements of the RHR

.4 Figure 1. Geographical Areas of Regional Planning O rganizations

Figure 2 . Class I Areas in the VISTAS Region5

II. Summary of Action

EPA is proposing a limited approval of a revision to the South Carolina state implementation plan (SIP) submitted by the State of South Carolina, through the South Carolina Department of Health and Environmental Control (SC DHEC), on December 17, 2007, tha t addresses regional haze for the first implementation period. This revision addresses the requirements of the Clean Air Act (CAA or Act) and EPA‟s rules that require states to prevent any future and remedy any existing anthropogenic impairment of

visibil ity in mandatory Class I areas (national parks and wilderness areas) caused by emissions of air pollutants from numerous sources located over a wide geographic area (also referred to as the “regional haze program”). States are required to assure reasonabl e progress toward the national goal of achieving natural visibility conditions in Class I areas. EPA is proposing a limited approval of this SIP revision to implement the regional haze requirements for South Carolina on the basis that the revision, as a w hole, strengthens the South Carolina SIP. Additionally, EPA is proposing to rescind the federal regulations previously approved into the South Carolina SIP on July 12, 1985, and November 24, 1987, and to rely on the provisions in South Carolina‟s December 17,

2007 , SIP submittal to meet the monitoring and long

- term strategy (LTS) requirements for reasonably attributable visibility impairment (RAVI). EPA has previously proposed a limited disapproval of the South Carolina regional haze SIP because of defici encies in the State‟s regional haze SIP submittal arising from the remand by the U.S. Court of Appeals

for the District of Columbia Circuit (D.C. Circuit ) to EPA of the Clean Air Interstate Rule (CAIR). Consequently, EPA is not proposing to take action in this rulemaking to address the State‟s reliance on CAIR to meet certain regional haze requirements.6

III. Evaluation of Regional Haze SIP Submittal

A

. Identification of Areas

The SIP must identify each mandatory Class I Federal area located within the State and in each mandatory Class I Federal area located outside the State that may be affected by emissions from within the State. Where a mandatory Class I Federal area is in multiple states, a description of how the states have assigned responsibilities for the area needs to

be included.

State Regional Haze Submittal SC SIP Narrative, Page 16:

South Carolina has one Class I Federal area within its borders: Cape Romain. The SC Department of Health and Environmental Control (SC DHEC) Bureau of Air Quality is responsible for developing the South Carolina‟s Regional Haze SIP. This SIP establishes RPGs for visibility improvement at this Class I Federal area and determines the BART

r equirements and long

- term strategy necessary to achieve those RPGs within the first regional haze planning period. In developing this SIP, SC DHEC has also considered that emission sources outside of South Carolina may affect visibility at its Class I Fede ral area, and that emission sources within South Carolina may affect visibility at Class I Federal areas in neighboring states.

Figure 1.4

- 1 South Carolina Class I Federal Area

Figure 3. South Carolina Class I Federal Area

EPA Findings : EPA proposes to find that South Carolina has adequately addressed this provision.7

III. Evaluation of Regional Haze SIP Submittal

B

. Reas onable Progress Goals (RPGs) Developmen t
B.1. Calculations of B aseline V isibility C onditions : ((40 CFR 51.308(d)(2)(i))

The period for establishing baseline visibility conditions is 2000 to 2004. For each mandatory Class I Federal area located within the State, the State must determine the average degree of visibility impairment (expressed in deciviews) for the most impair ed and least impaired days (i.e. the 20% most impaired days and 20% least impaired days) for each of these years

. Baseline conditions are the average of the se annual values

. For each mandatory Class I Federal area located within the State, the SIP needs to calculate the number of deciviews by which baseline conditions exceed natural visibility conditions for the most impaired and least impaired days.

Where onsite monitoring is not available

, the baseline visibility conditions must be

established using the most representative monitoring available for the 2000

- 2004 period

in consultation with EPA.

State Regional Haze Submittal

SC SIP Narrative , Pages 21

- 22 :

SC DHEC estimated baseline visibility conditions at Cape Romain based on sampling

data col lected at its IMPROVE monitoring site. A five

- year average (2000 to 2004) was calculated for each value (both best and worst) in accordance with 40 CFR 51.308(d)(2)

and the EPA Guidance for Tracking Progress Under the Regional Haze Rule . The light

extinct ion and dv visibility values for these worst and best days are based on data and calculations included in Appendix B.4 of this SIP. Appendix B includes a demonstration of the appropriateness of these values for each Class I area.

Baseline Visibility Condi tions

– Cape Romain SC

Class I Area Average for

20% Worst Days (deciviews) Average

for 20% Best Days (deciviews) B ext (Mm

- 1)

Average for 20% Worst Days B ext (Mm

- 1)

Average for 20% Best Days

Cape Romain 26.5 5.9 147.3 42.4 Figure 4. Baseline Visibility Conditions

– Cape Romain SC

EPA Findings : EPA proposes to find that South Carolina has adequately addressed this provision.8

III. Evaluation of Regional Haze SIP Submittal

B . Reasonable Progress Goals (RPGs) Development

B.2. Calculations of N atural V isibility C onditions: ((40 CFR 51.308(d)(2)(iii))

For each mandatory Class I Federal area located within the State, natural visibility conditions must be calculated by estimating the degree of visibility impairment existing

under natural conditions for the most impaired and least impaired days, based on available monitoring information and appropriate data analysis techniques as specified in

EPA

- 454/B

- 03

- 005

, Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Program or an approved alternative technique

.

State Regional Haze Submittal

SC SIP Narrative

, Page 21 :

Natural background visibility, as defined in Guidance for Estimating Natural Visibility Condition Under the Regional Haze Program , EPA

- 454/B

- 03

- 005, September 2003, is based on annual average concentrations of fine particle components. The same annual average natural background visibility is assumed for all Class I Federal areas in the eastern U.S. (separate values are estimated for the western U.S.). Natural background visibility for the 20 percent worst days is estimated by assuming that fine particle concentrations for natural background are normally distributed and that the 90 th percentile of the annual distribution represents na tural background visibility on the 20 percent worst days.

In the 2003 guidance, the EPA also provided 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 such a refinement would be to provide more accurate estimates with changes to the extinction algorithm that may include the concentration values, factors to calculate extinction from a measured particular species and particle size, the extinction coefficie nts for certain compounds, geographical variation (by altitude) of a fixed value, and the addition of visibility pollutants.

In 2005, the IMPROVE Steering Committee made recommendations for a refined equation that modifies the terms of the original equati on to account for the most recent data. The choice between use of the old or the new equation for calculating the visibility metrics for each Class I Federal area is made by the state in which the Class I Federal

area is located.

The new IMPROVE equation accounts for the effect of particle size distribution on light extinction efficiency of sulfate, nitrate, and organic carbon. New terms are added to the equation to account for light extinction by sea salt and light absorption by gaseous nitrogen dioxide. Site

- specific values are used for Rayleigh scattering to account for the

site

- specific effects of elevation (and temperature). Separate relative humidity enhancement factors are used for small size distribution sulfate or nitrate, large size

distribution s ulfate or nitrate, and sea salt. The elemental carbon (light

- absorbing9

carbon), fine soil, and coarse mass terms do not change between the original and new IMPROVE equations. The VISTAS states chose to use the new IMPROVE equation as the basis for the

conc eptual description because it takes into account the most recent review of the science and because it is recommended by the IMPROVE Steering Committee. For more detailed discussion of the two IMPROVE equations, see Appendix B.2.

Figure 5 presents estimated natural background conditions for Cape Romain. Natural background visibility is predicted to be between 12 and 13 dv. Appendix F, Chapter 4 clarifies how each term was derived to predict the following estimates. EPA has define d a set of default Natural Conditions (EPA, 2003b) that have been updated for the new IMPROVE equation on the VIEWS website and are used in this section.

19B

Natural Background Conditions Cape Romain SC

Class I Area Average for

20% Worst Days (deciviews) Average

for 20% Best Days (deciviews) B ext (Mm

- 1)

Average for 20% Worst Days B ext (Mm

- 1)

Average for 20% Best Days

Cape Romain 12.1 14.3 34.2 18.1 Figure 5. Natural Background Conditions

- Cape Romain SC

EPA Findings: EPA proposes to find that South Carolina has adequately addressed this provision and

that t he natural background conditions that were used in the reasonable progress assessment were developed in an acceptable manner. The State used the new IMPROVE equation and developed concentrat ions for each term of the equation consistent with the recommendations and default data from the IMPROVE Steering Committee. In EPA‟s document, “Additional Regional Haze Questions

, ” dated September 27, 2006 (under Miscellaneous #1), EPA stated that it wou ld approve a state‟s use of the new IMPROVE equation for reasonable progress. That specific answer suggested that the new equation should be applied consistently in the development of a state‟s regional haze SIP.

The State of South Carolina consistently applied the new IMPROVE equation in its regional haze analyses. Concentration data developed using chloride data was used to develop natural background data for reasonable progress and most of the BART evaluations. However, sodium ion data was used on a case

- by

- case basis in some BART evaluation modeling that used the new IMPROVE equation.

Because chloride ions react with sulfuric and nitric acid gases in the atmosphere, the concentrations of sea salt, as developed using chloride data, is lower than that developed using sodium data, providing a conservative estimate of the contribution of se a salt to visibility impairment. While the use of sodium ion data is believed to provide a more accurate estimate of sea salt concentrations, IMPROVE has not routinely collected this data. SC DHEC chose to use chloride data, which IMPROVE does collect, i n the reasonable progress assessment to be consistent with the VISTAS RPO states in their regional modeling to evaluate reasonable progress with respect to the glidepath. With the10

exception of a few facilities where the State allowed the use of the more a ccurate sodium ion data, chloride data was also used in the BART evaluation modeling. In the cases where the use of the sodium ion data was allowed, the State required supplementary data analysis using strontium data as a marker to support the use of this data.

EPA finds the general use of the chloride data to be appropriate since it is much more widely available than sodium ion data. EPA also finds the use of the sodium data for several BART evaluations to also be appropriate since the sodium ion data is generally regarded to be more accurate. Finally, EPA notes that the sea salt term in the new IMPROVE equation contributes only a few percent of the total of the natural background during best day conditions and much less under worst day conditions. H ence, there is a negligible difference resulting from South Carolina‟s use of both chloride and sodium data in the reasonable progress and BART assessments.

References use in the EPA review:

1. Additional Regional Haze Questions, EPA, September 27, 2006 Rev ision. Answers to questions that PA received from various States and Regional Planning Organizations (RPOs) related to the submission of regional haze SIPs under the program described by 40 CFR 51.308. This document provides guidance to the State air pol lution control agencies and the general public on meeting the regional haze SIP requirements.

2. January 18, 2007, email from Marc Pitchford

, NOAA

- Air Resources Laboratory

, to Brenda Johnson , EPA . Subject: “Re: December discussions.”

3. Powerpoint presentat ion of the: Natural Haze Levels II: Application of the New IMPROVE Algorithm to Natural Species Concentration Estimates. Final Report of the Natural Haze Levels II Committee to the RPO Monitoring/Data Analysis Workgroup.11

III. Evaluation of Regional Haze SIP Submittal

B . Reasonable Progress Goals Development

B.3. Uniform Rate of Progress ( UROP or “ Glidepath ” ) for Reasonable Progress : (40 CFR 51.308(d)(1) and (40 CFR 51.308(d)(1) (i)(B))

For each mandatory Class I Federal area located within the State, t he State must establish goals (expressed in deciviews) that provide for reasonable progress towards achieving natural visibility conditions. For each Class I area within the S tate, the S tate must analyze and determine the rate of progress needed to attain natural visibility conditions by the year 2064 and determine the uniform rate of visibility improvement (measured in deciviews) that would need to be maintained during each implementation period in order to attain natural visibility conditions by 2064. Th e State must show that the reasonable progress goal for each mandatory Class I Federal area represents at least as much visibility improvement as is expected to result from implementation of other requirements of the CAA during the applicable planning peri od (40 CFR 51.308(d)(1)(vi))

. The reasonable progress goals must provide for an improvement in visibility for the most impaired days over the period of the implementation plan and ensure no degradation in visibility for the least impaired days over the sa me period.

State Regional Haze Submittal

SC SIP Narrative

, Pages 27

- 28 :

3.1 Glidepath For Class I Federal Area In South Carolina The following is a glidepath for Cape Romain. Natural background visibility is predicted

to be between 12 and 13 dv.12

Table 8.Uniform Rate of Progress Glidepath for 20% worst days at Cape Romain SC

SC SIP Narrative, Page s 60

- 61 :

7.2.4 Model Results for the 2018 Base G2 Inventory Compared to the Uniform Rate of Progress Glidepath for SC Class I Federal Area Using 2000

- 2004 IMPROVE monitoring data, the dv values for the 20 percent best days in each year are averaged together, producing a single average dv value for the best days. Similarly, the dv values for the 20 percent worst days in each year are averag ed together,producing a single average dv value for the worst days.Figure 7.2.4

- 1 illustrates the predicted visibility improvement by 2018 resulting from the Base G2 inventory that represents implementation of existing federal and state regulations, compar ed to the uniform rate of progress glidepath for Cape Romain. The red lines show the target natural condition in 2064 for the 20 percent worst days, and the incremental dv changes resulting from a uniform rate of progress between current and natural condit ions in 2064, for average 20 percent worst visibility days in the 2000

- 2004 baseline period. The purple lines show the improvement expected from existing and planned emission controls during the period of the first long term strategy.

... Note that for the Class I Federal area in SC, visibility is expected to improve to levels better than the glidepath by 2018 based solely on reductions from existing and planned emission controls from other CAA programs.

SC SIP Narrative , Pages 95

- 96:13

7.9 Post

- BART Visi bility Improvement Expected at Cape Romain by 2018, Compared to the Glidepath As discussed earlier in Chapter 7, visibility on the 20 percent worst visibility days is expected to improve to levels better than the glidepath by 2018 based solely on reductions from existing and planned emission controls. Figure 7.9

- 1 reveals the predicted visibility (dv) in 2018 on the worst days at Cape Romain.

... In addition to improvement in visibility on the 20 percent worst visibility days, visibility on the 20 pe rcent best days is also projected to improve in 2018 at Cape Romain. Figure

7.9

- 2 reveals the predicted visibility (dv) in 2018 on the best days at Cape Romain.

Table 9. Uniform Rate of Progress Glidepath for 20% best days at Cape Romain SC

EPA Finding s : EPA proposes to find that South Carolina has a dequately addressed this provision. South Carolina provided sound technical documentation to support the State‟s RPGs (labeled “Method 1 Prediction” in Tables 8 and 9) for the best and worst days at Cape Ro main.14

III. Evaluation of Regional Haze SIP Submittal

C . Long

- Term Strategy

C.1. Technical Basis for Strategy (40 CFR 51.308(d )( 3)(iii))

The SIP must document the technical basis, including modeling, monitoring and emissions information, on which the State is relying to determine its apportionment of emission reduction obligations necessary for achieving reasonable progress in each mandatory Class I Federal area it affects. The State may meet this requirement by relying on technical analyses developed by the regional planning organization and approved by

a ll State participants

.

Modeling is not used to determine reasonable progress goals and does not determine whether reasonable progress has been met. Modeling is one part of the reasonable progress analysis. The modeling results are used to compare progress made through emission reductions with future year visibility at Class I areas

. Note that the emission inventory requirements under 40 CFR 51.308(d)(4)(v) are addressed in this section

.

State Regional Haze Submittal

The RHR requires states to establish RPGs for visibility improvement at each affected Class I area covering each approximately ten

- year period until 2064. The first set of RPGs will comprise South Carolina‟s Long Term Strategy (LTS) covering the period

fro m the present until 2018. The LTS contains the following components:

SC SIP, Appendix H, p.H

- 5:

1. Inventory of all controls required or expected under all federal and state regulations by 2009 and 2018.

2. Modeled expected visibility improvement from planned or existing (Base G) controls and Comparison of Base G results for 2018 to the uniform rate of progress, or “glidepath,” for Cape Romain. (See also EPA TSD Section III.B.3)

3. Discussion of emissions sensitivity model runs to help determine which pollutants and source categories are contributing the most to visibility impairment at Cape Romain (runs conducted by the Georgia Institute of Technology).

4. Examination of SO 2 Area of Influence (AOI) projections for Cape Romain, and also for any surrou nding states‟ Class I areas whose AOI includes South Carolina counties, to determine which specific sources are most likely to be impairing visibility at specific

Class I areas.

5. Application of the four “statutory factors,” listed in 40 CFR 51.308(d)(1) (i)(A) to those sources identified in the previous step. ( See also EPA TSD Section III.C.3)15

6. Identify control determination (based on the results of the four factor analyses) for specific sources.

7. Identify of BART

- eligible sources. (See also EPA TS D Section III.D.1)

8. Examine BART

- exemption modeling for BART

- eligible sources to include modeling demonstration of visibility improvement after inclusion of BART and reasonable progress

control determinations. (See also EPA TSD Section III.D.2)

9. Determination of RPGs based on the visibility improvement expected by 2018.

SC SIP Narrative starting at page 35:

Modeling for regional haze was performed by VISTAS for the ten southeastern states, including South Carolina . The sections below outline th e methods and inputs used by VISTAS for the regional modeling. Additional details are provided in Appendices C, D, E, F, G, I, M and O. The modeling analysis is a complex technical evaluation that begins by selection of the modeling system. VISTAS decide d to use the following modeling

system:

Meteorological Model: The Pennsylvania State University/National Center for Atmospheric Research ( PSU/NCAR ) Mesoscale Meteorological Model ( MM5 ) is a nonhydrostatic , prognostic meteorological model routinely used for urban

- and regional

- scale photochemical, fine particulate matter, and regional haze regulatory modeling studies. A coarse 36

- km horizontal grid domain covering the

continental United States was used as the grid domain for MM5.

Emissions Model: The Sparse Matrix Operator Kernel Emissions ( SMOKE ) modeling system is an emissions modeling system that generates hourly gridded speciated emission inputs of mobile, nonroad mobile, area, point, fire and biogen ic emission sources for photochemical grid models.

Air Quality Model: USEPA‟s Models

- 3/ Community Multiscale Air Quality (CMAQ) modeling system is an „One

- Atmosphere‟ photochemical grid model capable of addressing ozone, particulate matter (PM), and visib ility and acid deposition at regional scale. For the VISTAS modeling, a coarse 36

- km grid resolution was used for modeling the entire United States and a finer 12

- km grid was used to model the eastern United States. The CMAQ model was run in the

one

- way n ested grid mode. This allowed the larger outer domains to feed

concentration data to the inner nested domain.

Figure 5.4.1

- 1 shows the MM5 horizontal domain as the outer most, blue grid with the CMAQ 36

- km domain nested in the MM5 domain. Figure 5.4.1

- 2 shows the 12

- km grid, modeling domain for the VISTAS region.16

Figure 5.4.1

- 1. The MM5 horizontal domain is the outer most, blue grid, with the CMAQ 36

- km domain nested in the MM5 domain.

Figure 5.4.1

- 2. A more detailed view of the 12

- km grid over the VISTAS region.

Care was taken in the selection of the modeling system used to develop the long

- term strategy. The VISTAS states tried to ensure that the models selected were scientifically appropriate for the intended application and be freely accessible to all stakeholders. Scientifically appropriate means that the models address important physical and chemical phenomena in sufficient detail, using peer

- reviewed methods. Freely accessible means that model formulations and coding are freely av ailable for review and that the models are available to stakeholders, and their consultants, for execution and verification at no or low cost. These criteria were used in selecting the modeling system are documented on pages 26

- 30 of the SIP Narrative.17

E PA Modeling Guidance recommends modeling an entire year or, at a minimum, several days in each quarter of a year to adequately represent the range of meteorological conditions that contribute to elevated levels of fine particulate matter. The year 2002 was selected by VISTAS as the modeling year for this demonstration. Meteorological inputs were developed for 2002 using MM5. Emission inventories were also developed for 2002 and processed through SMOKE. These inputs were used in the air quality model to pred ict fine particle mass and visibility. The model results for 2002 were compared with observed meteorological and air quality data to evaluate model performance. Several configurations of the meteorological and air quality model were evaluated to select a

c onfiguration that gave the best overall performance for the VISTAS region.

Sources and Pollutants R elied on for LTS ( SC SIP Narrative, P ages 67

- 69) :

An important step toward identifying further reasonable progress measures is to identify the key pollutants contributing to visibility impairment at the Cape Romain Class I area. To understand the relative benefit of further reducing emissions from differ ent pollutants, source sectors, and geographic areas, VISTAS engaged the Georgia Institute of Technology to perform emission sensitivity model runs using CMAQ. Emissions in 2009 were reduced by 30 percent for each pollutant sensitivity run. The pollutan t
contributions that were evaluated were:

SO2 from EGU sources in each VISTAS state, other RPOs in the VISTAS 12 km grid, and Boundary Conditions from outside the 12 km domain. SO2 from non

- EGU point sources in each VISTAS state, other RPOs, and Boundary Conditions NOx from ground level sources (on

- road plus off

- road plus area) in each VISTAS state and other RPOs. In the VISTAS states, these reductions were only applied to specific counties that were of concern for 8

- hour ozone nonattainment. NOx from poi nt (EGU plus non

- EGU) sources in each VISTAS state and other

RPOs NH3 from all sources in VISTAS and other RPOs Volatile Organic Compounds from anthropogenic and biogenic sources in the 12 km modeling domain Primary Carbon from all ground level sources in each VISTAS state and other RPOs. In the VISTAS states, these reductions were only applied to specific counties that were of concern for PM2.5 nonattainment. Primary Carbon from all point sources in each VISTAS state and other RPOs Primary Carbon from all fires in each VISTAS state and other RPOs

Figure 7.4

- 1 shows, the greatest benefits on the 20 percent worst days for Cape Romain are projected to result from further reducing SO 2 from EGUs. Reductions from EGUs in SC would have the greatest benefits; the contribution from other VISTAS states is relatively small. Additional, smaller benefits would come from additional SO 2 emission reductions from non

- utility, industrial point sources. While determined not to be necessary at this time, SC DHEC will re

- exami ne the need for additional non

- EGU controls during the state‟s five

- year progress report.18

Figure 7.4

- 1 CMAQ Projections of Visibility Responses on 20% Worst Days at Cape

Romain to 30% Reductions from the 2009 Base D Inventory for Visibility

- Reducing Pollutants in Different Source Categories and Geographic Areas

As shown in Figure 7.4

- 1, ammonia (NH 3 ) is a large contributor to visibility impairment on the 20 percent worst days i n Cape Romain. As such, some of the worst days at Cape

Romain and at other coastal sites in VISTAS states occur in the winter when ammonium nitrate has a somewhat larger contribution to visibility impairment. Therefore, reducing

ammonia emissions would be more beneficial for reducing ammonium nitrate contributions to visibility impairment in wintertime than further reducing NO X emissions from either ground or point sources.

VOCs in South Carolina originate primarily from biogenic sources (such as vegetativ e emissions) and also contribute to visibility impairment. Controlling anthropogenic sources of VOCs has little, if any, visibility benefit at Cape Romain. Reducing primary carbon from point sources, ground level sources, and fires is projected to have alm ost no visibility benefit at Cape Romain.

As Figure 7.4

- 1 also shows, Cape Romain experiences a high degree of impact from boundary conditions coming from the east. This is primarily due to atmospheric

conditions that cause SO 2 originating from the easter n coast of the U.S. to be blown out

over the Atlantic Ocean and then re

- enter the model domain. Rather than classify these emissions as unique to South Carolina, the model attributes these emissions as a boundary condition. Note that these results from em ission sensitivity runs are consistent with the conclusions drawn from the 2000

- 2004 baseline monitoring data. Again, sulfate was found to be the dominant contributor to visibility impairment on peak summertime days. Wintertime ammonia is an important cont ributor for sites near the coast. SC DHEC concludes that reducing SO 2 emissions from EGU and non

- EGU point sources in the VISTAS states would have the greatest visibility benefits for Cape Romain. Contributions from outside the VISTAS 12

- km modeling domain are particularly important to determining contributions to coastal Class I Federal areas like Cape Romain. These19

results are consistent with CMAQ model results, in that contributions from international emissions to visibility at VISTAS Class I Federal are as are closer to the boundaries

Emissions Controls Modeled ( SC SIP Narrative, P ages 53

- 60) :

Significant CAA emission control programs and consent decrees are being implemented, or will be implemented between the baseline period and 2018. These programs and decrees are described in more detail below and are projected to result in substantial

visib ility improvement at Cape Romain.

Federal and State Control Requirements

Clean Air Interstate Rule (CAIR)

-

U CAIR will permanently cap emissions of sulfur dioxide (SO 2 ) and nitrogen oxides (NO X ) in the eastern U.S. When fully implemented, CAIR will

reduce SO 2 emissions in these states by over 70 percent and NO X emissions by over 60 percent from 2003 levels. Appendix M illustrates what sources within South Carolina‟s AOI are subject to CAIR and those identified sour ce‟s planned emission reductions.

The following table indicated the EGU controls considered for South Carolina sources in assessing the LTS.

EGU Controls for South Carolina Used in Base G 2018 Emission Inventory

Plant name & ID Unit NOx 2018 Controls SO2 2018 SO2 Controls Jefferies ORISID = 3319 3

4 none

none None

None

Wateree ORISID=3297 WAT1

WAT2 SCR

SCR Scrubber

Scrubber Canadys ORISID=3280 CAN1

CAN2

CAN3 None

None

None None

None

Scrubber Rainey ORISID=3407 CT1A

CT1B SCR

SCR None

None

Taken from Appendix H table on page Appendix H

- 13

U NO X SIP Call

U . Phase I of the NO X SIP call applies to certain EGUs and large non

- EGUs, including large industrial boilers/turbines and cement kilns. States in the VISTAS region affected by the NO X SIP call hav e developed rules for the control of NO X emissions that have been approved by the EPA. This rule results in a 68 percent reduction in NO X emissions from large stationary combustion sources by 2006. For this analysis, the emissions for NO X SIP call

- were c apped for affected sources at 2007 levels and carried forward the capped levels for the 2009/2018 future year inventories.

U NC Clean Smokestacks Act

U . Under the act, which was enacted in 2002, coal

- fired power plants in North Carolina must achieve a 77

- percent cut in nitrogen oxide (NO X ) emissions by 2009 and a 73

- percent cut in sulfur dioxide (SO 2 ) emissions by 2013.

U Consent Agreements (Santee Coope r, TECO, VEPCO, Gulf Power Crist 7, and EKPC)

U .20

• A 2004 EPA consent decree calls for Santee Cooper to install and commence operation of continuous emission control equipment for PM/SO 2 /NO X emissions; comply with

system

- wide annual PM/SO 2 /NO X emissions limits; agree not to buy, sell, or trade

PM/SO 2 /NO X allowances allocated to Santee Cooper System as 55 a result of said agreement; and to comply with emission unit limits of said agreement.

• Under a settlement agreement, Tampa Electric will install perma nent emissions control equipment to meet stringent pollution limits; implement a series of interim pollution

reduction measures to reduce emissions while the permanent controls are designed and installed; and retire pollution emission allowances that Tampa Electric or others could use/sell to others to emit additional pollution into the environment.

• Virginia Electric and Power Co. (VEPCO) agreed to eliminate 237,000 tons of sulfur dioxide (SO 2 ) and nitrogen oxides (NO X ) emissions each year from eight coa l

- fired electricity generating plants in Virginia and West Virginia between now and 2013.

• A 2002 agreement calls for Gulf Power to upgrade its operation to cut NO X emission rates by 61 percent at its Crist generating plant by 2007, with major reductions beginning in early 2005. The Crist plant is a significant source of NO X emissions in the

Pensacola area.

• A July 2, 2007, consent decree between the EPA and East Kentucky Power Cooperative (EKPC) requires the utility to reduce its NO X and SO 2 emissions by installing/continuously operating selective catalytic reduction (SCR) technology and flue gas desulfurization equipment (FGD). According to the EPA, the plant‟s total emissions will drop from between 50 and 75 percent from 2005 levels. As with all fe deral consent decrees, EKPC is precluded from using reductions required under other programs, such

as the Clean Air Interstate Rule.

One

- hour ozone SIPs (Atlanta / Birmingham / Northern Kentucky).

U The purpose of these respective SIPs is to grant fi nal approval to the request for redesignation of the 1

- hour ozone NAAQS nonattainment area to attainment. New SIPs have been submitted to the EPA for public comment and approval. These SIPs require NO X reductions from specific

coal

- fired power and address transportation plans in these cities.

NO x RACT in 8

- hour Nonattainment Area SIPs

- NC DENR applied NO X RACT to two facilities located in the Charlotte nonattainment area: Philip Morris USA and Norandal

USA.

Heavy Duty Diesel (2007) Engi ne Standard

- - A PM emissions standard for new heavy

duty engines of 0.01 grams per brake

- horsepower

- hour (g/bhp

- hr) is to take full effect for 2007 model year diesel engines. This standard also requires reductions in NO X and non

methan e hydrocarbons (NMHC) of 0.20 g/bhp

- hr and 0.14 g/ bhp

- hr, respectively. These

NO X and NMHC standards for diesel engines will be phased in together between 2007 and 2010. Also, sulfur in diesel fuel must be lowered to enable modern pollution

- control

techn ology to be effective on these diesel

- powered trucks and buses. The EPA will21

require a 97 percent reduction in the sulfur content of highway diesel fuel from its current level of 500 parts per million (low sulfur diesel, or LSD) to 15 parts per million (u ltra

- low sulfur diesel, or ULSD).

Tier 2 Tailpipe

-

U . Tier 2 is a fleet averaging program, modeled after the California LEV II standards. Manufacturers can produce vehicles with emissions ranging from relatively dirty to zero, but the mix of vehicles a manufacturer sells each year must have average

NO X emissions below a specified value

.

Large Spark Ignition and Recreational Vehicle Rule

- EPA has adopted new standards for emission of oxides of nitrogen (NO X ), hydrocarbons (HC), and carbon monoxide (CO) from several groups of previously unregulated non

- road engines. Included in these sources are the Large Industrial Spark

- Ignition Engines and Recreational Vehicles. Spark

- ignition non

- road engines are those powered by gasoline, liquid propane gas, or compressed natural gas rated over 19 kilowatts (kW) (25 horsepower). These engines are used in commercial and industrial applications, including forklifts, electric generators, airport baggage transport vehicles, and a variety of farm and construction appl ications. Recreational Vehicles include snowmobiles, off

- highway motorcycles, and all

- terrain

vehicles. Rules were initiated in 2004 and are fully phased in by 2012.

Non

- road Diesel Rule

- This rule sets standards that will dramatically reduce emissions by over 90 percent from non

- road diesel equipment and dramatically reduce sulfur levels by 99 percent from current levels in non

- road diesel fuel starting in 2007. This rule will apply to most non

- road diesel fuel in 2010 and to fuel in locomotives and marine vessels

in 2012.

Industrial Boiler/Process Heater MACT standards

- The applied MACT control efficiencies were four percent for SO 2 and 40 percent for PM 10 and PM

2.5 . However, as of

J une 08, 2007, the Industrial Boiler/Process Heater MACT standard was vacated. A mandate without a stay was issued July 30, 2007. As a result, sources that were subject to the rule may need to file applications for permits containing MACT limits derived on a

case

- by

- case basis within a time specified by the EPA or SC DHEC.

Combustion Turbine MACT

- The projection inventories do not include the NO X co

benefit effects of the MACT regulations for Gas Turbines or stationary Reciprocating

Internal Combustion Engines, which the EPA estimates to be small compared to the overall inventory.

VOC 2

- , 4

- , 7

- , and 10

- year MACT Standards

- Various point source MACTs and associated emission reductions were implemented. We did not count reductions occurring before 2002.

M odel P erformance E valuation ( SC SIP Narrative, P ages 44

- 52) :22

The initial modeling effort focused on evaluating previous regional air quality modeling applications and testing candidate model configurations for the SMOKE emissions and CMAQ model for the VISTAS 36

- km and 12

- km modeling domains. This effort resulted in a report recommending the model configuration for the annual emissions and air quality modeling, which is included as part of the VISTAS Emissions and Air Quality Modeling Protocol. (See Appendix C) The evaluation of the meteorological modeling configuration can be found in Appendix F, with a summary of the final meteorological and air quality modeling configuration in the modeling protocol contained in Appendix E and Appendix C, respect ively.

Air quality model performance for the 2002 modeling year was initially tested in 2004 using an early version of the VISTAS emissions inventory. In keeping with the one

atmosphere objective of the CMAQ modeling platform, model performance was

evalu ated based on measured ozone, fine particles, and acid deposition in the Air Quality System (AQS), IMPROVE, Speciated Trends Network (STN), Southeastern Aerosol Research and Characterization (SEARCH), National Acid Deposition Program (NADP)

and Clean Air S tatus and Trends Network (CASTNet) monitoring networks

The air quality model‟s performance was evaluated with respect to individual components of fine particulate matter (PM 2.5 ), as good model performance of the component species will dictate good model p erformance of total or reconstituted fine particulate matter. Model performance of the total fine particulate matter and the resulting total light extinction was also provided as a means to discuss the overall model performance for the SIP.

The soccer and bugle plots for the all of the VISTAS IMPROVE monitors are included here for summary purposes. The goal and criteria levels used for regional haze model performance were 30% and 60%, respectively, for mean fractional bias and 50% and 75%, respectively , for mean fractional error. Plots were presented for the average monthly concentrations and the performance statistics for all of the most significant light scattering component species (Sulfate, Nitrate, and Organic Carbon) for the 20% best days and 20% worst days. Plots for individual IMPROVE monitors associated with the South Carolina Class I area are included in Appendix F.

The soccer plots of monthly concentrations (Figures. 6.2

- 1 and 6.2

- 2) show that values for nitrate generally fall outside of cr iteria performance thresholds (red box). Sulfates and organic carbon generally fall within goal thresholds (green box), with a couple of months falling just outside the goal thresholds but well within the criteria thresholds. In these figures, each point represents a month. Figure 6.2

- 3 contains separate soccer plots for each season. The seasonal plots emphasize poorer nitrate performance in the summer (does not even appear on the plots provided because performance is off scale with other constituents), when observed nitrate is quite low and predicted nitrate is even lower. When concentration is factored into performance criteria, nitrate performance improves with respect to mean fractional bias and mean fractional error (Figures 6.2

- 4

and 6.2

- 5)23

Addi tionally, performance assessed at the “one atmosphere” level was also deemed acceptable for ozone and particulate matter at various monitoring sites (STN, FRM, CASTNet, etc.). Overall, VISTAS found the Base G2 modeling results to be representative and acc eptable for use in modeling projection for ozone, particulate matter, and regional haze.2425

South Carolina Class I Area Performance

The following section provides stacked bar charts comparing observed fine particulate matter composition and modeled fine particulate matter composition. The charts display both the 20 percent best days and the 20 percent worst days. The stacked bar chart allows a side by side comparison of the day observed and modeled compositional and total light extinction. Within each bar the color codes are:

• Yellow = light extinction due to sulfates (b ext SO4)

• Red = light extinction due to nitrates (b ext NO3)

• Gr een = light extinction due to organic carbon (b ext OC)

• Black = light extinction due to elemental (b ext EC)

• Brown = light extinction due to soil (b ext Soil)

• Grey = light extinction due to coarse mass (b ext CM)

The components are presented in the same ord er for both the observed (left hand bar) and modeled bar (right hand bar), so it easy to identify days when the prediction light extinction for the component differs from the observed. The total height of the bar provides the total reconstructed particulat e matter light extinction value. A cursory view of the stacked bar charts reiterates that sulfates are a large contributor to light extinction at Cape Romain on both the 20 percent best days and the 20 percent worst days.

Comparing the 20 percent best da y chart to the 20 percent worst days chart, illustrates that the various components of particle pollution play a more prominent role in the 20 percent best days than with the 20 percent worst days. Also, the species make

- up on the 20 percent best days vari es more widely compared to the 20 percent worst days. This suggests accurately modeling each species is especially important on the 20 percent best days.26

With the bar chart for the 20 percent worst days, you can see model performance does improve across t he sites. Light extinction due to sulfate prediction is better, but it still falls short on some days. Light extinction due to organic carbon also becomes more important to total light extinction. Much like the sulfate component, the organic carbon

compone nt accuracy has improved performance over the 20 percent best day series, though some days are still under predicted.

Overall, SC DHEC found model performance to fall within acceptable limits for model performance. SC DHEC further asserts the one atmosphe re modeling performed by the VISTAS contractors is representative of conditions in the southeastern states and is applicable for use in attainment demonstrations.27

Once model performance was deemed adequate, the current and future year emissions were processed through the emissions model. The air quality modeling results are used to determine a relative reduction in future visibility impairment, which is used to determine reasonable progress.

More detailed discussions of the modeling protocol, quality assurance report, procedures, models and data used in the regional haze analysis can be found in Appendices C, D, E, F and G. The archival and acquisition of data and modeling input and output files are discussed in Appendix I.

EPA Findings : In accordance with 40 CFR 51.308(d)(3), the State of South Carolina provided the appropriate supporting documentation for all required analyses used to determine the State‟s LTS. The technical analyses and modeling used to develop the glidepath and to

suppo rt the LTS are consistent with EPA‟s RHR, and interim and final EPA Modeling Guidance. EPA proposes to accept the VISTAS technical modeling to support the LTS and determine visibility improvement for the uniform rate of progress because the modeling syste m was chosen and simulated according to EPA Modeling Guidance. EPA proposes to agree with the VISTAS model performance procedures and results, and that the CMAQ is an appropriate tool for the regional haze assessments for the South Carolina LTS and region al haze SIP.

CAIR is also an element of South Carolina‟s LTS. CAIR rule revisions were approved

into the South Carolina SIP in 2007 and 2009. See 72 FR 57209 (October 9, 2007); 74 FR 53167 (October 16, 2009). South Carolina opted to rely on CAIR emis sion reduction28

requirements to satisfy the BART requirements for SO 2 and NO X from EGUs. See 40 CFR 51.308(e)( 4). Therefore, South Carolina only required its BART

- eligible EGUs to evaluate PM emissions for determining whether they are subject to BART, and if applicable, for performing a BART control assessment. Additionally, South Carolina

concluded that no addi tional controls beyond CAIR are reasonable for reasonable

progress for SO 2 for its EGUs for this first implementation period.

The RHR allows states to implement an alternative program in lieu of BART so long as the alternative program can be demonstrate d to achieve greater reasonable progress toward the national visibility goal than would BART. Under regulations issued in 2005 revising the regional haze program, EPA made just such a demonstration for CAIR. See 70 FR 39104 (July 6, 2005). EPA‟s regulat ions provide that states participating in the CAIR cap

- and trade program under 40 CFR part 96 pursuant to an EPA

- approved CAIR SIP or which remain subject to the CAIR federal implementation plan in 40 CFR part 97

need not require affected BART

- eligible ele ctrical generating unit (EGUs) to install, operate, and maintain BART for emissions of SO 2 and NOx. See 40 CFR 51.308(e)(4). Because CAIR did not address direct emissions of PM, states were still required to conduct a BART analysis for PM emissions from EGUs subject to BART for that pollutant. Challenges to CAIR, however, resulted in the remand of the rule to EPA. See

North Carolina v. EPA , 550 F.3d 1176 (D.C. Cir. 2008).

EPA issued a new rule in 2011 to address the interstate transport of NOx and SO 2 in the

eastern United States. See 76 FR 48208 (August 8, 2011) (“the Transport Rule,” also

known as the Cross

- State Air Pollution Rule). On December 30, 2011, EPA proposed to find that the trading programs in the Transport Rule would achieve greater re asonable progress towards the national goal than would BART in the states in which the Transport Rule applies. See 76 FR 82219. Based on this proposed finding, EPA also proposed to revise the RHR to allow states to substitute participation in the trading programs under the Transport Rule for source

- specific BART. EPA has not yet taken final action on that rule. Also on December 30, 2011, the D.C. Circuit issued an order addressing the status of the Transport Rule and CAIR in response to motions filed by numerous parties seeking a stay of the Transport Rule pending judicial review. In that order, the D.C. Circuit stayed the Transport Rule pending the court‟s resolutions of the petitions for review of

that rule in EME Homer Generation, L.P. v. EPA (No. 11

- 1302 and consolidated cases). The court also indicated that EPA is expected to continue to administer CAIR in the interim until the court rules on the petitions for review of the Transport Rule.

In a separate action, EPA has proposed a limited disapproval of the South Carolina regional haze SIP because of deficiencies in the State‟s regional haze SIP submittal arising from the State‟s reliance on CAIR to meet certain regional haze requirements.

S ee 76 FR 82219 (December 30, 2011). EPA is not proposing to take action in this rulemaking on issues associated with South Carolina‟s reliance on CAIR in its regional

haze SIP.

Also, on July 30, 2007, the D.C. Circuit mandated the vacatur and remand of t he Industrial Boiler MACT Rule. Notwithstanding the vacatur of this rule, the VISTAS29

states, including South Carolina, decided to leave these controls in the modeling for their regional haze SIPs since it is believed that by 2018, EPA will have re

- promulg ated an industrial boiler MACT rule or the states will have addressed the issue through state

- level

case

- by

- case MACT reviews in accordance with section 112(j) of the CAA.

EPA proposes to find this approach acceptable for the following reasons. Effecti ve July 30, 2007, the D.C. Circuit mandated the vacatur and remand of the Industrial Boiler

MACT Rule. 1 This MACT was vacated since it was directly affected by the vacatur and

remand of the Commercial and Industrial Solid Waste Incinerator Definition Rule . EPA proposed a new Industrial Boiler MACT rule to address the vacatur on June 4, 2010, (75 FR 32006) and issued a final rule on March 21, 2011 (76 FR 15608). The VISTAS modeling included emissions reductions from the vacated Industrial Boiler MACT rule

, and South Carolina did not redo its modeling analysis when the rule was re

- issued. Even though South Carolina‟s modeling is based on the vacated Industrial Boiler MACT limits, the State‟s modeling conclusions are unlikely to be affected because the expe cted reductions due to the vacated rule were relatively small compared to the State‟s total SO 2 , PM 2.5 , and coarse particulate matter (PM 10 ) emissions in 2018 (i.e., 0.2 to 0.5 percent, depending on the pollutant, of the projected 2018 SO 2 , PM 2.5 , and PM 10 inventory). Thus, EPA does not expect that differences between the vacated and final Industrial Boiler MACT emissions limits would affect the adequacy of the existing South Carolina regional haze SIP. If there is a need to address discrepancies between projected

emissions reductions from the vacated Industrial Boiler MACT and the Industrial Boiler MACT issued March 21, 2011 (76 FR 15608), EPA expects South Carolina to do so in
the State‟s five

- year progress report.

References used in the EPA review:

1. EPA‟s Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze . Located at
http://www.epa.gov /scram001/guidance/guide/final

- 03

- pm

- rh

- guidance.pdf ( EPA

- 454/B

07

- 002 ), April 2007.

2. “(Draft) Guidance for Demonstrating Attainment of Air Quality Goals for PM 2.5 and Regional Haze”, (2001), EPA, http://www.epa .gov/ttn/scram/guidance_sip.htm.

3. 2002 Base Year Emission Inventory SIP Planning: 8

- hr Ozone , PM2.5 and Regional

Haze

, EPA memorandum from Lydia Wegman , EPA, to Peter Tsirigotis, EPA, November 18, 2002.

4. Clean Air Act (CAA) §§112(j)(2), (3), (5), and (6).

5. CAA §505 specifies procedures for notification to the Administrator and affected

s tates.

1 See NRDC v. EPA , 489 F.3d 1250 (D.C. Cir. 2007).30

III. Evaluation of Regional Haze SIP Submittal

C . Long

- Term Strategy

C.2 . Identification of Sources and Factors to be Considered for Reasonable Progress : (40 CFR 51.308(d)(3)( iv

- v))

The State must identify all anthropogenic sources of visibility impairment considered by the State in developing its long

- term strategy. The State should consider major and minor stationary sources, mobile sources, and area sources. The State must consider , at a
min imum, the following factors in developing its long

- term strategy : (A) emission reductions due to ongoing air pollution control programs, including measures to address reasonably attributable visibility impairment; (B) m easures to mitigate the impacts of

co nstruction activities; (C) e missions limitations and schedules for compliance to achieve the reasonable progress goal; (D) source retirement and replacement schedules; (E) smoke management techniques for agricultural and forestry management purposes

includ ing plans as currently exist within the State for these purposes; measures to mitigate the impacts of construction activities; (F) enforceability of emission limitations and control measures; and the (G) anticipated net effect on visibility due to projecte d

c hanges in point, area, and mobile source emissions over the period.

State Regional Haze Submittal:

SC SIP Narrative

, Pages 79

- 82 :

U SC DHEC Process on Reasonable Progress Assessment

U : Step 1: Determine pollutants of concern.

VISTAS evaluated the species contribution on the 20 percent worst days and concluded that sulfate accounted for more than 70 percent of the visibility

- impairing pollution. VISTAS States concluded that controlling SO 2 emissions was the appropriate step in addressing the reason able progress assessment for 2018. Step 2: Determine which source categories should be evaluated for reasonable progress.

Since SO 2 point source emissions in 2018 represent more than 95 percent of the total SO 2 emissions inventory, VISTAS States concluded that the focus should be on EGU and non

EGU SO 2 emissions. Step 3: Determine if CAIR is sufficient for reasonable progress. “In determining the emissions and visibility improvement achieved during each implementation period, States should include all air q uality improvements that will be achieved by other programs and activities under the CAA and any State air pollution control requirements” (64 FR 35733). In keeping with this recommendation, South Carolina, as part of its long

- term reasonable progress anal ysis to consider potential sources contributing to visibility impairment, examined other CAA requirements such as CAIR. SC DHEC evaluated the amount of SO 2 reduction from EGU‟s due to CAIR. Since the EGUs will be reducing their SO 2 emissions by approximate ly 78 percent through these programs, SC DHEC concluded that additional EGU control during this time period (between 2007 and 2018) was not reasonable. Under the RHR, each “state must identify the uniform rate of progress over the 60 year period that would be needed to attain natural background conditions by the year 2064” (64 FR 35732). To calculate the rate of progress represented by each reasonable31

p rogress goal, South Carolina compared baseline visibility conditions to natural visibility conditions in i ts Class I Federal area and determined the uniform rate of visibility improvement (measured in dv) that would need to be maintained during each implementation period in order to attain natural visibility conditions by 2064. SO 2 emission reductions that are predicted by the IPM to meet the CAIR requirements are not certain due to the current rule‟s provisions for regional emissions trading and the use of banked Title IV allowances. However, “SIP approvability criteria [under CAIR] are intended to provide as much certainty as possible that, whichever sources a State chooses to control, the controls will result in the required amount of emissions reductions” (91

FR 25256). Furthermore, for EGUs subject to CAIR, the EPA evaluated a number of factors including th e cost of compliance and the time necessary for compliance. Within

the CAIR rule, EPA determined “that the earliest reasonable deadline for compliance

with the final highly

- cost effective control levels for reducing emissions was 2015...” (70

FR 25197

- 25198) . Based on this analysis, SC DHEC has determined that CAIR controls satisfy reasonable progress for the initial planning period. These criteria along with the success of NO X SIP call reductions and SC DHEC‟s ongoing review of Prevention of Significant Det erioration/New Source Review permits serve to address this uncertainty and promote confidence in projected reasonable progress. Continued collaboration

between SC DHEC and the FLM will ensure that trends in growth are addressed. SC

DHEC also intends to re

- evaluate the IPM predictions of SO 2 reductions for CAIR at the time of the next periodic report in 2012 to ensure that the individual unit‟s reductions currently predicted by IPM for CAIR are in fact taking place. Based on the visibility improvements expec ted from SO 2 emission reductions predicted by IPM and required by CAIR, SC DHEC concludes that additional SO 2 control measures for South Carolina‟s EGUs would not achieve reasonable progress during this first assessment period (between baseline and 2018). Step 4: Determine which emission units would be evaluated based on impact. SC DHEC calculated the fractional contribution from all emission units within the SO 2 AOI for Cape Romain and identified those emission units with a contribution of 0.01 or above (o r greater than or equal to one percent contribution) to the visibility impairment

at Cape Romain. SC DHEC chose to adopt one percent as the contribution threshold

used to consider a source for four factor analysis of reasonable further controls based on

p recedence established in other Federal programs. While SC DHEC recognizes the important difference between significant impact levels of human health standards and visibility standards, the Department contends that its approach to establishing a visibility contribution threshold based in part on impact levels related to the precedence established by human health standards is appropriate and serves to further protect visibility. Step 5: Evaluate the four factors. Each emission unit identified in Step 4 above was evaluated using the statutory and regulatory factors of: (1) cost of compliance, (2) time necessary for compliance, (3) the energy and non

- air quality environmental impacts of compliance, and (4) the remaining useful life of the emissions unit. For th e limited purpose of evaluating the cost for the reasonable progress assessment in this first regional haze SIP, SC DHEC believes it is

not equitable to require non

- EGUs to bear a greater economic burden than EGUs for a given control strategy. In determin ing reasonable costs of controls for the EGU sector,32

SC DHEC determined that the cost of S0 2 controls (the primary contributor to visibility impairment in the state) beyond those required by CSA and CAIR are not reasonable. The capital and operating costs to implement CSA were converted to the same 15

- year time period as the costs from AirControlNet. The unit

- by

- unit costs ranged from about $912 to $1,922 dollars per ton of SO 2 removed; with an average cost per system ranging from $1,231 to $1,375 dollars per ton of SO 2 removed (Appendix H.2.a). Therefore, $2,000.00 per ton was selected as the threshold for costs for non

- EGU sources. This limit

acts as an inherent barrier to non

- EGUs considering additional controls. The cost of controls is significant

-- not just in terms of capital cost, but also the cost of labor needed to efficiently and effectively maintain the equipment. “The availability of skilled labor

-- specifically, boilermakers

-- is an important constraint for the installation of significant

amounts of emission controls. Boilermakers are skilled steel workers who are specially

trained to install both NO X controls, such as SCR, and SO 2 controls, such as scrubbers” (69 FR 4617).

SC SIP Narrative

, Pages 56

- 57:

The SC Forestry Commission (“SCFC”) has developed (and recently revised as of August 2006) the Smoke Management Guideline for Vegetative Debris Burning Operations , which serves to regulate vegetative debris burning for forestry, agriculture, and wildlife purposes in the State of SC. SC DHEC‟ s Bureau of Air Quality has developed a state air pollution control regulation (R. 61

- 62.2, Prohibition of Open Burning ) that prohibits: open burning of any/all household garbage, open burning for the purpose of land clearing or right of way maintenance in areas other than predominantly residential, and open burning of residential construction waste from building and construction operations unless specific conditions are met. When weighed together, these documents address all sources of fire used for land

m anagement purposes within South Carolina and effectively minimize visibility impacts while recognizing the important ecological role that fires can and do play. Appendix H.1 includes a memorandum of understanding between the SCFC and SC DHEC and

represent s the State‟s collective commitment to develop a comprehensive approach to establish and maintain a smoke management plan. In addition to considering emission reductions due to ongoing air pollution programs as required under the RHR Section 308(d)(3)(v)(A ), states are also required to consider the measures to mitigate the impacts of construction activities [40 CFR 51.308(d)(3)(v)(B) and agricultural and forestry smoke management [40 CFR 51.308(d)(3)(v)(E)]. These measures are discussed in more detail in Ap pendix H.

SC SIP Narrative

, Pages 33, 59 and 60:

Table 4.1 is a summary of the 2002 baseline emission inventory for SC. The complete inventory and discussion of the methodology is contained in Appendix D. The emissions

summaries for other VISTAS states can also be found in Appendix D.4.b.33 56B Table 7.2.3

- 1 is a summary of the 2009 Base G2emission inventory. The complete inventory and discussion of the methodology is contained in Appendix D.2 (a, b, and c).

Table 7.2.3

- 2 is a summary of the 2018 Base G2 emission inventory. The complete inventory and discussion of the methodology is contained in Appendix D. 2 (a, b, and c).

EPA Findings : EPA proposes to find that S outh C arolina has adequately addressed this provision.

.34

III. Evaluation of Regional Haze SIP Submittal

C . Long

- Term Strategy

C.3 . Source or Source Category Specific Analyses for Reasonable Progress : (40 CFR 51.308(d)(1)(i)(A)

For the significant sources and source categories located within the State and determined to be significantly impacting a mandatory Class I Federal area, the S tate must document

that it considered the costs of compliance, the time necessary for compliance, the energy

and non

- air quality environmental impacts of compliance, the remaining useful life of any potentially affected sources, and how these factors were taken into consideration in establishing the reasonable progress goal.

State Regional Haze Submittal

38B SC SIP Narrative

, Pages 98

- 101 :

Section 51.308(d)(1) of the final RHR requires that a State establish “reasonable progress goals” for each Class I Federal area within the state. In establishing reasonable progress goals, the CAA provided analytical requirements for setting these goals (know as the four factors) which include: the cost of compliance, the time necessary for compliance, the energy and non

- air quality environmental impacts of compliance, and the remaining useful life of any existing source subject to such requirements. In developing South Carolina‟s reasonable progress goals, VISTAS, in November 2006, contracted with Alpine Geophysics to develop a cost control analysis that showed various control options for sources within an area of influence for Ca pe Romain and other Class

I areas. Since sulfate is the predominant cause of visibility impairment in the VISTAS region, South Carolina and the other VISTAS states decided to concentrate on reduction of SO 2
, the precursor to sulfate formation, during this first planning period. As such, the cost control list was sorted for the SO 2 emissions (Q) of each source divided by the distance (d) in kilometers to each class one area, or Q/d, and maximum residence time, RTmax. All sources with a Q/d greater than or eq ual to five and an RTmax greater than or equal to 10 percent were added to the list for further consideration because it has been determined that these sources may contribute to visibility impairment on the 20 percent worst days. Sources meeting these crit eria include:

• Santee Cooper

– Jefferies, South Carolina

• Santee Cooper

– Cross, South Carolina

• SCE&G

– Canadys, South Carolina

• International Paper

– Georgetown, South Carolina

• Giant Cement, South Carolina

• Holcim Holly Hill, South Carolina

• Mead Westvaco, South Carolina

• DAK Americas, South Carolina

• International Pa Savannah Electric

– McIntosh, Georgia

• International Paper

– Savannah, Georgia35

A cost threshold of $2,000.00 per ton for controls was then applied. Of the remaining facilities, all EGUs subject to CAIR were not considered as part of South Carolina‟s control strategy because CAIR makes substantial SO 2 emission reductions and SO 2 is the leading pollutant that contributes to visibility impairment at Cape Romain. As Table

7.8.2

- 3 illu strates, only two BART

- eligible EGU sources in South Carolina emit any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any Class I area. The two facilities, SCE&G Williams and SCE&G
Wateree, were unable to demonstrate less than a 0.5 dv impact at Cape Romain. However, as stated earlier in the narrative of this appendix, these two BART

- eligible EGU sources are subject to CAIR, and South Carolina has determined that implementation of CAIR is equivale nt to BART. As such no formal BART determinations were made for either of these two South Carolina sources. SC DHEC multiplied the Q/d factors and the RTmax factors for all sources within a sulfate AOI for a given Class I area, then calculated a total and divided each product by that total to estimate the fractional contribution of each unit. Only the units with fractions of 0.01 or above (or greater than or equal to one percent contribution) were then evaluated using the four factor analysis.

Table 8.0

- 2 i llustrates South Carolina‟s approach to establishing reasonable progress goals by ranking the non

- EGU sources that were evaluated using the four factors. This list of sources was generated by evaluating each facility‟s relative cost of compliance.

The cos t of compliance (cost per ton) was calculated by dividing the total cost of the control strategy application by the amount of tons of SO 2 reduced by the application of the control strategy. Under South Carolina‟s approach, facilities whose costs fall belo w the $2,000.00 threshold amount established were asked to conduct a four factor analysis. These facilities include:

• MeadWestvaco, SC

• International Paper, Georgetown, SC

• Giant Cement, SC

• International Paper, Savannah, GA

• Holcim: Holly Hill, SC

• DAK Americas, SC The final four

-

factor analysis for the remaining non

- EGU sources was performed by the facilities and reviewed by the Department. The reasonable progress goals established by SC DHEC for this first planning period take into account the con trols identified as reasonable within the four factor analyses.

State County Plant (2002) (2018 ) Distance (km) Q/d Q/d^2 RT
Max** RTM*(Q/d) Fraction

South Carolina Berkeley Co SANTEE COOPER
JEFFERIES 11,315 6,761 45.80 147.61 3.22 72.76 10740.1 0.102423

South Carolina Berkeley Co SANTEE COOPER
JEFFERIES 11,789 6,609 45.80 144.30 3.15 72.76 10499.27 0.100127

South Carolina Charleston Co MEADWESTVACO
CORPORATION INC 2,315 2,706 29.58 91.47 3.09 72.76 6655.357 0.063469

South Carolina Georgetown Co INTERNATIONAL

PAPER
:GEORGETOWN 3,152 3,655 56.05 65.21 1.16 69.84 4554.266 0.043432

South Carolina Berkeley Co SANTEE COOPER
CROSS 0 3,835 63.26 60.62 0.96 72.76 4410.711 0.04206336

South Carolina Colleton Co SCE&G:CANADYS 6,214 5,203 91.25 57.02 0.62 72.55 4136.801 0.039451

South Carolina Colleton Co SCE&G:CANADYS 6,585 5,144 91.12 56.45 0.62 72.55 4095.448 0.039056

South Carolina Berkeley Co SANTEE COOPER
CROSS 10,260 3,380 63.26 53.43 0.84 72.76 3887.567 0.037074

South Carolina Dorchester Co GIANT CEMENT CO 2,825 3,893 79.80 48.79 0.61 72.76 3549.96 0.033854

South Carolina Berkeley Co SCE&G:WILLIAMS 22,698 1,280 26.88 47.62 1.77 72.76 3464.831 0.033043

South Carolina Orangeburg Co HOLCIM:HOLLY HILL 2,957 4,074 82.56 49.35 0.60 54.08 2668.848 0.025452

South Carolina Charleston Co COGEN SOUTH 843 872 29.79 29.26 0.98 72.76 2128.958 0.020303

South Carolina Berkeley Co ALUMAX OF SOUTH
CAROLINA 749 957 39.06 24.50 0.63 72.76 1782.62 0.017

South Carolina Berkeley Co ALUMAX OF SOUTH
CAROLINA 749 957 39.17 24.43 0.62 72.76 1777.527 0.016951

South Carolina Berkeley Co ALUMAX OF SOUTH
CAROLINA 749 957 39.22 24.40 0.62 72.76 1775.344 0.016931

Georgia Chatham Co INTERNATIONAL

PAPER

- SAVANNAH

MILL 7,643 8,578 165.98 51.68 0.31 31.04 1604.147 0.015298

South Carolina Berkeley Co ALUMAX OF SOUTH
CAROLINA 749 957 44.04 21.73 0.49 72.76 1581.075 0.015078

South Carolina Dorchester Co SHOWA DENKO
CARBON 618 1,291 63.24 20.42 0.32 72.76 1485.759 0.014169

Georgia Effingham Co SAVANNAH
ELECTRIC:
MCINTOSH STEAM

- ELEC 7,089 7,015 155.93 44.99 0.29 31.04 1396.49 0.013318

South Carolina Orangeburg Co HOLCIM:HOLLY HILL 1,336 1,841 82.56 22.29 0.27 54.08 1205.443 0.011496

Edited from SC SIP, Appendix H.2.b :

SC SIP Narrative , Pages 104

– 106:37

MeadWestvaco: MeadWestvaco Corporation operates an unbleached paper mill in North Charleston, South Carolina. MeadWestvaco‟s primary source of SO 2 emissions are from its two recovery boilers: Recovery Boiler No. 1 and Recover Boiler No. 9. The units were installed in 1984 and 1966 respectively. Emissions from Recovery Boiler No. 1 are

c ontrolled by an ESP installed in 1984. Emissions from Recovery Boiler No. 9 are also controlled by an ESP, installed in 1977. The No.1 and No.9 recovery boilers are permitted to burn No.6 fuel oil, black liquor solids, spec oil and pitch as fuel. However, on August 25, 2006, MeadWestvaco submitted a Title V permit renewal application that included a 0.5 percent sulfur limit for fuel oil burned in the No. 9 Recovery Bo iler. The No. 1 Recovery Boiler has a SO 2 PSD limit that requires the boiler to limit the amount of high sulfur No. 6 fuel oil burned. International Paper, Georgetown: The International Paper Georgetown, South Carolina Pulp and Paper Mill is located in Geo rgetown, South Carolina. The Mill began operations in 1937. Primary operations at the mill include multiple fuel

- fired boilers,

chemical r ecovery operations, wood pulping operations, bleached papermaking, and additional operations and equipment necessary t o support these operations. Unit ID 01 includes equipment that supports the Power and Recovery Operations at the Mill and consists of: No. 1 Power Boiler, No. 2 Power Boiler, No. 1 Recovery Boiler, and No. 2 Recovery Boiler.

• No. 1 Power Boiler: The No. 1 Power Boiler is capable of burning bark, coal/synfuel, No. 6 fuel oil, natural gas, and propane. In addition, the boilers are capable of burning the following alternative fuels: wood

- waste (including pulping rejects and peat), used oil, cleanup media mate rials from virgin No. 6 fuel oil spills/leaks, wastewater sludge, containerboard clippings/pellets, paper waste, and tire

- derived fuel (TDF) and other rubber products. Emissions from this unit are controlled by a cyclone and electrostatic precipitator.

• N o. 2 Power Boiler: The No. 2 Power Boiler is capable of burning bark, coal/synfuel, No. 6 fuel oil, natural gas, and propane. In addition, the boilers are capable of burning the following alternative fuels: wood

- waste (including pulping rejects and peat), used oil, cleanup media materials from virgin No. 6 fuel oil spills/leaks, wastewater sludge, containerboard clippings/pellets, paper waste, and tire

- derived fuel (TDF) and other rubber products. Emissions from this unit are controlled by a cyclone and ele ctrostatic precipitator.

• No. 1 Recovery Boiler: This recovery boiler fires black liquor solids and No. 6 fuel oil, natural gas, and/or propane as auxiliary fuels. The No. 1 Recovery Boiler nominal throughput is 3.2 million pounds of black liquor solids per day, 494 MMBtu/hr from firing fuel oil, 24,000 scf/hr of natural gas, and 60 MMBtu/hr of propane. The unit is controlled by an electrostatic precipitator.

• No. 2 Recovery Boiler: This recovery boiler fires black liquor solids and No. 6 fuel oil,

natur al gas, and/or propane as auxiliary fuels. The No. 2 Recovery Boiler nominal throughput is 4.1 million pounds of black liquor solids per day, 494 MMBtu/hr from firing fuel oil, 24,000 scf/hr of natural gas, and 60 MMBtu/hr of propane . The unit is

controlle d by an electrostatic precipitator followed by a wet scrubber. International Paper, Savannah: The Savannah Mill is located in Chatham County, Georgia, across the Savannah River from South Carolina. It occupies a 450

- acre site,38

and produces unbleached kraft linerboard, corrugating medium, and saturating kraft

paper. The Savannah Mill‟s primary source of process steam used in its pulp and papermaking operations is the No. 13 Power Boiler unit with a maximum firing rate of up to 1,280

MMBtu/hour. The boiler is equipped with an electrostatic precipitator (ESP) for controlling particulate emissions. The service life of the No. 13 Boiler is estimated to be at least 40 years from installation, or until approximately 2022.

Giant Cement: Giant Cement Company owns and operates a Portland cement manufacturing facility located in Harleyville, South Carolina. Giant‟s operations at this facility include limestone (marl) quarrying, stone crushing, cement manufacturing, packaging, and shipping. The facility operates one dry process cement kiln system to produce cement clinker. The cement kiln system is equipped with fabric filters to control PM emissions. In 2005, Giant completed the modernization of its cement manufacturing facility at this site, which replaced four wet

- proc ess cement kilns with the newer single dry

- process kiln. In order to generate enough heat necessary to produce clinker, the facility is permitted (Part 70 Title V/PSD Permit issued in 2003) to combust a multitude of fuels consisting of more conventional fuels (e.g., oil, coal, natural gas) as well as

waste derived fuels (e.g., liquid and solid hazardous waste

- derived fuels). Giant‟s PSD permit application utilized an emission factor of 3.5 pounds of SO 2 per ton of clinker produced, substantially lowering emissions reported from its previous wet

- process kiln

system. Holcim: Holcim

, Inc. operates a cement plant near Holly Hill, SC. This process consists of two wet process kilns and associated process equipment that were replaced in 2003 by a new preheater/pr ecalciner kiln with associated process equipment. The kiln system consists of a preheater/precalciner kiln with an in

- line raw mill. The kiln progressively heats the raw materials to over 2600 degrees Fahrenheit, producing clinker from the raw

materials. T

he kiln is permitted to burn coal, carbon based materials such as coke, No. 6 fuel oil, natural gas, hazardous waste derived fuel (HWDF), tire derived fuel (TDF), and

non

- hazardous waste derived fuel. Emissions from the kiln are controlled by an ESP and fa bric filters.

DAK Americas: DAK operates a facility (known as the Cooper River Facility) in Moncks Corner, South Carolina, just north of Charleston. The Cooper River Facility (formerly operated by Dupont) has three main process areas consisting of: 1) a co ntinuous polymerization area for polyethylene terephthalate (PET) production, 2) a PET finishing area to produce fiber products, and 3) a PET finishing are to produce bottle resin products. The Cooper River Facility‟s primary source of SO 2 emissions are fr om its coal

fired boiler (Boiler No. 2). Boiler No. 2 is a 206 MMBtu/hr bituminous coal

- fired boiler. Boiler No. 2 is equipped with a baghouse to control PM emissions and a one percent sulfur limit on the coal used in Boiler No. 2 controls sulfur emissions

. Compliance with this limit is demonstrated through calculations based on 12

- month rolling sum averages from supplier certifications as stated in the facility‟s Part 70 Title V p ermit. The service life of Boiler No. 2 is estimated to be at least 50 years from i nstallation, or at least 31 additional years.

U 8.1.1.3 Source Specific Control Technology Options

MeadWestvaco: Since Recovery Boiler No. 9 currently operates using low sulfur No. 6 fuel oil,39

MeadWestvaco conducted an abbreviated four factor analysis focused on evaluating the feasibility of burning alternative low

- sulfur fuels for Recovery Boiler No. 1. This analysis is summarized in Appendix N. The cost alternatives to switching from high sulfur (2.1 percent sulfur content) No. 6 fuel oil to low sulf ur No. 6 fuel oil (0.5 percent sulfur content) for Recovery Boiler No. 1 range from $3,359.00 per ton to $7,463.00 per ton of

SO 2 removed; above the $2,000.00 cost per ton threshold. Switching to lower sulfur fuel oil (e.g., No. 2 Fuel oil) and natural gas would also require equipment and operating modifications that would further increase costs and require significant time to implement. Switching to lower sulfur fuels would also result in non

- air quality impacts related to additional environmental and safe ty issues associated with increased truck traffic and additional manpower and costs for monitoring and maintaining systems. IP Georgetown: In conducting a four factor analysis, IP Georgetown focused its evaluation on the feasibility of burning alternative low

- sulfur fuels (the costs of which were identifies as below the cost threshold of $2,000.00 per ton). This analysis is summarized in Appendix N. The cost alternatives associated with switching to lower sulfur fuel range from $6,417.00 per ton to $10,012.00 per ton of SO 2 removed. In addition, the changes

r equired to modify the fuel tanks, piping systems, delivery systems, and burners would also require considerable time to implement. The additional non

- air quality impacts of switching to lower sul

fur fuels would also limit the IP Georgetown Mill‟s ability to engage in burning tire

- derived fuels, create additional environmental and safety issues associated with increased truck traffic, and require secondary containment associated

with increased tank storage. IP Savannah: In conducting a four factor analysis, IP Savannah focused its evaluat ion on the feasibility of several SO 2 control technologies, including: 1) a wet caustic packed scrubber (FGD), 2) a wet limestone spray tower (FGD), 3) a semi

- dry l ime spray dryer, 4) dry sorbent injection (DSI), and 5) lower sulfur fuels. These technologies were chosen because they have been demonstrated and are commercially available for coal

- fired utility boilers. All of the control options have been demonstrated and are considered technologically feasible. The cost associated with each of these alternatives was calculated using the Coal Utility Environmental Cost (CUECost) software tool and determined to be above the $2,000.00 cost per ton threshold (with costs ra nging from $2,950.00 to $34,927.00 per ton of SO 2 removed). These alternatives would take from 2010 to 2012 to implement and result in significant non

- air quality impacts to include: substantial increased use of fresh water, the generation of industrial wa stewater, potentially substantial increases in solid waste generated, additional environmental and safety issues associated with increased truck traffic, and require additional manpower and costs for monitoring and maintaining systems.

Giant: In conducting a four factor analysis, Giant focused its e valuation on the feasibility of burning lower sulfur fuels (the costs of which were ident ified by the Department as below the cost threshold of $2,000.00 per ton). This analysis is summarized in Appendix N.

Giant determined that its costs associated with switching to lower sulfur fuel would range f rom $7,801.00 per ton to $11,152.00 per ton of SO 2 removed. The time required to install fuel tanks, piping systems, and delivery systems capable of being used with lowe r40

sulfur fuel oils would also require considerable time to implement. The modernized cement kiln system (completed in 2005) provides Giant the option to operate with up to 100 percent substitution rates of conventional fuels. The additional non

- air quality impacts of switching to lower sulfur fuels would also limit the facility‟s ability to e ngage in burning liquid and solid waste

- derived fuels, effectively adding to the non

- air quality impacts of finding alternate means of disposing and storing this waste.

Holcim: In conducting a four factor analysis, Holcim also focused its evaluation on the feasibility of burning lower sulfur fuels (the costs of which were identified by the Department as below the cost threshold of $2,000.00 per ton). This analysis is sum marized in Appendix N. Holcim‟s analysis determined that the cost to switch to fuel oil with a sulfur content of 0.9 percent would cost $41,039.00 per ton of SO 2 removed. Moreover, the additional non

air quality impacts of switching to lower sulfur fuels w ould also limit the facility‟s ability to engage in burning hazardous waste and tire derived fuel, thereby potentially increasing the non

- air quality impacts associated with disposing and storing this waste. Holcim also contends that up to 95 percent of SO 2 emission produced at its Holly Hill plant can be absorbed in the process. This is because the raw materials used to produce “kiln feed” at the Holly Hill plant consists primarily of limestone (or other forms of calcium carbonate) and its new kiln system uses a highly alkaline feed material. Holcim‟s analysis indicates that the new process could result in potential SO 2 reductions of 160 tons per year.

DAK Americas: In conducting a four factor analysis, DAK Americas focused its evaluation on the feasibility of several SO 2 control technologies, including: (1) low sulfur coal, (2) wet flue gas desulfurization (FGD), (3) spray dryer absorber (SDA), (4) fluidized

- bed combustion (FBC) with limestone, and (5) dry sorbent injection (DSI). These technolog ies were chosen because they have been demonstrated and are commercially available for coalfired utility boilers. Of the aforementioned control technologies all but the FBC were

deemed t o be technologically feasible. Of the remaining four options, all were determined to be above the cost threshold of $2,000.00 per ton (see Appendix N). In addition each of the control technologies would take from one to three years to implement and (with the exception of fuel switching) result in significant non

- air quality impacts to include: substantial increased use of fresh water, the generation of industrial wastewater, and potentially substantial increases in solid waste generated. The results of the four factor analyses (contained in Appendix N) indicate that no addit ional controls are reasonable at this time. However, further future reductions by way of additional controls have been discussed and will be evaluated during the next planning stage.

EPA Findings : EPA proposes to find that South Carolina has adequately a ddressed this provision. After reviewing SC DHEC‟s methodology and analyses, EPA proposes to find

that South Carolina‟s conclusion that no further controls are reasonable at this time acceptable. EPA determined that South Carolina adequately evaluated th e control technologies available at the time of its analysis and applicable to these types of facilities and consistently applied its criteria for reasonable compliance costs. The State also included appropriate documentation in its SIP of the technical a nalysis it used to assess the need for and implementation of reasonable progress controls. Although the use of a41

specific threshold for assessing costs means that a state may not fully consider available

emissions reduction measures above its threshold th at would result in meaningful visibility improvement, EPA believes that the South Carolina SIP still ensures reasonable progress. In proposing to approve South Carolina‟s reasonable progress analysis, EPA is placing great weight on the fact that there is no indication in the SIP submittal that South Carolina, as a result of using a specific cost effectiveness threshold, rejected potential reasonable progress measures that would have had a meaningful impact on visibility in its

Class I area. EPA notes that given the emissions reductions resulting from CAIR and the measures in nearby states, the visibility improvements projected for the affected Class I area are in excess of that needed to be on the uniform rate of progress.42

III. Evaluation of Regional Haze SIP Submittal

C . Long

- Term Strategy

C.4. Enforceability of Reasonable Progress Measures [40CFR51.308(d)(3)]: The plan needs to provide enforceable emissions limitations and schedules for compliance for each newly adopted measure needed to achieve t he reasonable progress goal s

.

State Regional Haze Submittal SC SIP Narrative, Page s 98

- 108 :

No newly adopted source specific measures were required to achieve the reasonable progress goals.

EPA Findings : EPA proposes to find that S outh C arolina has adequately addressed this provision

.43

III. Evaluation of Regional Haze SIP Submittal

D

. Best Available Retrofit Technology (BART) Requirements

D.1 Identification of all BART Eligible Sources: The SIP should include a list of all

BART

- eligible sources within the State

.

State Regional Haze Submittal

SC SIP Narrative

, Starting at Page 82 :

Section 169A of the CAA directs States to assess certain large, older emission sources for

additional controls in order to address visibility impacts. States are directed to conduct BART determinations for such sources in specific source categories, and which contribute to visibility impairment in Class I areas. The 1999 regional haze rule includes 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 Gu idelines”) 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 tons or more of a visibility

- impairi ng 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 „„e mits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any such area.‟‟

For those sources subject to BART, Section 169A(g)(7) of the CAA requires that States must consider the following facto rs in making BART determinations: (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.

SC SIP Narrative, Pages 82

- 84 :

The following is a list of facilities with BART

- eligible sources in South Carolina . TRC Environmental Corporation was retained by VISTAS to conduct BART exemption modeling for several sources in South Carolina. A list of these ten facilities is included in Appendix H.6. Three of the ten facilities (Shaw Industries: Anderson; Solutia, In c.; and Honeywell: Clemson) were later determined to be exempt form BART exemption modeling due to boiler size. Appendix H.7 contains a detailed description of each BART

- eligible emission unit at the following facilities identified as having BART

- eligible sources in South Carolina.

U FACILITY NAME ALBEMARLE, CORP.44

BOWATER INC. PAPER/PULP

BP AMOCO CHEMICAL

- COOPER RIVER PLANT

DAK AMERICA

EASTMAN CHEMICAL

INTERNATIONAL PAPER GEORGETOWN MILL

INVISTA MAY PLANT INVISTA SARL SPARTANBURG (FORMERLY KOSA:ARTEVA)

ISG GEORGETOWN

MEADWESTVACO KRAFT MILL

MILLIKEN CHEMICAL: DEWEY PLANT

OWENS CORNING: ANDERSON

RHODIA CHARLESTON

SANTEE COOPER GRAINGER

SANTEE COOPER JEFFERIES

SANTEE COOPER WINYAH

SCE&G CANADYS

SCE&G WATEREE

SCE&G WILLIAMS

STONE CONTAINER FLORENCE

WELLMAN INC PALMETTO PLANT

These BART

- eligible sources were identified using the following methodology in the

BART Guidelines 2 :

• One or more emission units at the facility fit within one of the 26 categories listed in the BART 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 potential emissions, considering federally enforceable permit limits, from all emission units identified in the previous two bullets were greater t han 250 tons or more per year of any of these visibility

- impairing pollutants: SO 2 , NO X , and PM

10

.

The BART Guidelines recommend addressing these visibility

- impairing pollutants (SO 2
, NO X , and PM) and suggest that states use their best judgment in determi ning whether to address VOC and/or ammonia (NH 3 ) emissions. As the BART Guidelines recommend,

2 List of BART Source Categories. The BART requirement only applies to sources in specific categories listed in the Clean Air Act. These categories are: (1) Fossil

- fuel fired steam electric plants of more th an 250 million British thermal units (BTU) per hour heat input, (2) Coal cleaning plants (thermal dryers), (3) Kraft pulp mills, (4) Portland cement plants, (5) Primary zinc smelters, (6) Iron and steel mill plants, (7) Primary aluminum ore reduction plant s, (8) Primary copper smelters, (9) Municipal incinerators capable of charging more than 250 tons of refuse per day, (10) Hydrofluoric, sulfuric, and nitric acid plants, (11) Petroleum refineries, (12) Lime plants, (13) Phosphate rock processing plants, (1 4) Coke oven batteries, (15) Sulfur recovery plants, (16) Carbon black plants (furnace process), (17) Primary lead smelters, (18) Fuel conversion plants, (19) Sintering plants, (20) Secondary metal production facilities, (21) Chemical process plants, (22) Fossil

- fuel boilers of more than 250 million BTUs per hour heat input, (23) Petroleum storage and transfer facilities with a capacity exceeding 300,000 barrels, (24) Taconite ore processing facilities, (25) Glass fiber processing plants, and (26) Charcoal production facilities.45

South Carolina addressed SO 2 and NO X , and used PM

10 as an indicator for PM to identify BART

- eligible units. As discussed in detail in Appendix H.5, VISTAS modelin g demonstrates that neither VOCs nor NH 3 form point sources in the Southeast can reasonably be anticipated to contribute to visibility impairment in any Class I Federal area. For this reason, South Carolina did not evaluate emissions of VOC and NH 3 in its

BART determinations.

EPA Findings : EPA proposes to find that S outh C arolina has adequately addressed this provision.46

III. Evaluation of Regional Haze SIP Submittal

D . Best Available Retrofit Technology (BART) Requirements

D

. 2. Modeling or O ther Demonstrations for BART Exempt Sources: For each

BART

- eligible source in the State exempted from BART a demonstration, using an acceptable approach, that the source or group of sources does not violate the established threshold. The established exemption t hreshold for determining if a BART

- eligible source contributes to regional haze cannot exceed 0.5 deciviews.

State Regional Haze Submittal

SC SIP Narrative

, Pages 84

- 86 :

Under the BART Guidelines, states should exempt sources from BART if it is found that they do not contribute to visibility impairment in a Class I Federal area. In accordance with the BART guidelines, South Carolina chose to perform source

- specific analysis to determine which sources cause or contribute to visibility impairment using t he CALPUFF model. The CALPUFF modeling protocol used for determining which facilities are subject to BART is included in Appendix H. In accordance with the BART Guidelines and as justified in Appendix H (Section 7.4), a contribution threshold of 0.5

dv was used to determine which sources in South Carolina were subject to BART. Nineteen of 21 sources were able to demonstrate exemption. Facilities found to be subject to BART were asked to complete a BART analysis. Results of these demonstrations are

summarize d below in Table 7.8.2

- 1. Additional details are available in Appendix H.7.

As approved by EPA (Appendix O.1), SC DHEC is also using the chloride derived IMPROVE default sea salt estimate as the default value for use in the BART assessment for this first planning period. The Regional Haze rule, however, gives the state significant flexibility in making decisions concerning the BART analysis as part of the regional haze

process.

VISTAS along with other consultants have examined the effects of sea salt and proposed a hierarchy of methods for sea salt estimation based on a consideration of different factors impinging on how technically reliable each method is for estimating sea salt in the atmosphere. After taking into account the various method variables as presented in Appendix O.3 (including chlorine depletion and blank problems) SC DHEC is convinced that the use of the VISTAS sodium ion data is justified and provides the most rea listic, technically sound, yet reasonably conservative, estimate of sea salt in the Cape Romain Class I Federal area. This September 2002 through December 2004 sodium ion dataset results in a 0.77 ug/m 3 sea salt estimate for the Cape Romain Class I Federal area. As a result, SC DHEC has chosen to accept additional information on a case

- by

- case basis for several BART facilities that have requested a more refined approach to their BART exemption modeling. While SC DHEC believes that the use of the sodium ion derived alternative sea salt estimate would be justified for any facility modeling visibility impairment at Cape Romain, that refinement is not necessary if a facility exempts with a less refined method.47

Table 7.8.2

- 1 BART Modeling Results48

* Class I Federal areas within 300 km of the source ** Screening modeling max impact

In total, 19 of SC‟s 21 BART

- eligible sources were able to demonstrate that they did not cause or contribute to visibility impairment in any Class I Federal area within 300 km of the sources. At least 10 sources used the new IMPROVE equation in efforts to demonstrate exemption, including: all three SCE&G facilities (Canadys, Williams, and

W ateree); all three Santee Cooper facilities (Winyah, Jefferies, and Grainger); DAK; IP Georg etown; MeadWestvaco; and INVISTA.

65B

Determination of BART emissions to evaluate (from Appendix H

, P ages H

- 54

- 56 ) :

The guidelines required the States to include SO 2 , NOx, and direct particulate matter (PM) emissions, including both PM 10 and PM 2.5, in determining whether sources cause or contribute to visibility impairment. South Carolina and the VISTAS states used their best judgment and CMAQ sensitivity modeling to determine that VOC and ammonia emissions did not have an impact on visibility in th eir Class I areas and state. The results show that the maximum impact from eliminating all point source VOC emissions in the

VISTAS 12

- km domain is less than a 0.5 dv for all Class I areas in the VISTAS domain. VISTAS and the State of South Carolina conclu de that VOCs from point sources are not a visibility impairing pollutant for BART purposes and that BART

- eligible sources do not

need to consider VOC emissions.49

The State of South Carolina determined through modeling that ammonia emissions from point sources are not anticipated to cause or contribute significantly to any impairment of visibility at Cape Romain with the exception of one large point source (i.e.,

Me adwestvaco, 130 tpy NH3 and 29 km to nearest Class I area). VISTAS contracted with Georgia Institute of Technology to perform model sensitivity runs to determine the impact of point source ammonia on visibility in Class I areas. Removal of the large NH 3

e mission sources results in minimal impact on visibility at Class I areas in the VISTAS region. At their discretion, states may ask those few large sources to evaluate NH 3 impacts and potential controls for NH 3 . Based on annual CMAQ sensitivity analyses of the impacts of ammonia emissions as well as current emission rates, South Carolina determined that requiring to model ammonia impacts is not necessary at this time.

CALPUFF MODELING

South Carolina chose to use source

- specific analyses 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 H

. The source

- specific CALPUFF modeling protocols, which were supposed to be consistent with the VISTAS protocol, are also presented in Appendix H. SC DHEC also examined the appropriateness of the 0.5 deciview threshold for potential “clusters” of BART s ources that might be impacting a Class I area in a cumulative manner, and did not find evidence that an exemption threshold less than the 0.5 deciview threshold should be used. Appendix H‟s main document describing reasonable progress has additional infor

mation in Section 5.0 regarding individual source impacts upon Class I areas. In accordance with the BART Guidelines, a contribution threshold of 0.5 deciviews was used for determining which sources were subject to BART.

Justification of 0.5 dv contrib ution threshold for CALPUFF BART modeling (from SC SIP, Appendix H

, P ages H

- 52 and 53 ):

The Regional Haze rule gives the states considerable flexibility in determining a BART exemption threshold, stating only that a state should not set a threshold high er than 0.5 dv, while indicating that the state should consider the number of emission sources affecting the Class I Federal area, the magnitude of the sources‟ impacts, and the location of the sources. The number of BART sources and the different methods available for exemption by a source makes a straightforward, apples

- to

- apples determination of a proper threshold problematic. In fact, given the state‟s limited resources, it would be impossible to consider every source and every situation in a comprehe nsive manner. SC DHEC decided that a stepwise, common

- sense approach would satisfy the requirements of the rule while at the same time making the decision making process manageable.

For the eight facilities impacting the Wolf Island Class I Federal area, SC DHEC concluded that the EPA suggested contribution threshold of 0.5 dv was appropriate in this situation based on a qualitative analysis of these facilities and their predicted visibility impacts. None of the eight facilities in question are in close proximity to Wolf50

Island, with the closest being just over 200 km away. Considering results of the visibility impacts modeling conducted, with four of the facilities reporting a 12 km screening (maximum) impact well below 0.5 dv and the other four reportin g 4 km refined modeling impacts (98th percentile) below 0.3 dv, SC DHEC agrees with the state of Georgia that a 0.5 dv threshold is appropriate for the Wolf Island Class I Federal area and a lower

threshold was not warranted.

For the fourteen facilities impacting the Cape Romain Class I Federal area, a more detailed analysis was performed. Of the fourteen facilities, two (SCE&G Williams and Wateree) performed a four

- factor analysis and did not exempt. Of the remaining twelve facilities, only six (MeadW estvaco, DAK Americas, Santee Cooper Jeffries, Santee Cooper Winyah, International Paper Georgetown, and ISG Georgetown) were in close proximity to Cape Romain. For these six facilities, SC DHEC performed an analysis of the overlap in modeling impacts at Cape Romain. For this analysis, SC DHEC compiled the 8th highest impacts for each of the modeled years (2001, 2002, and 2003) to see what kind of overlap there was predicted on these days. It is important to note that, for this modeling, maximum predicte d 24

- hour emission rates were used. In actual operation, it is highly unlikely that each facility would be operating such that the maximum 24

- hr emissions occurred at the same time. Thus, it is very likely that the actual combined impact at the class I ar ea would be less than the sum of combined impacts from these facilities. Nevertheless, these 8th highest modeling days resulted in a total of 132 modeled days. Of the 132 days, there were only a total of 12 days were two or more facilities overlapped (fi ve days in 2001, four in 2002, and three in 2003) and only one day over the three years where three facilities overlapped. Thus, the overall impact from these facilities is relatively spread out, with very little overlap and certainly much fewer days of o verlap than the 100 days used by EPA in the BART rule. In addition, a 0.5 dv threshold is consistent with the 0.5 dv threshold that all of the other VISTAS states intend to adopt for the Class I Federal areas in their states. In view of all this, a 0.5 d v threshold is appropriate and a lower threshold is not warranted.

As a result, SC DHEC concluded that the EPA

- suggested contribution threshold of 0.5 dv was appropriate in this situation since there are a limited number of out of state sources that impa ct Cape Romain.

Use of the New IMPROVE Algorithm and Sea Salt ( from SC SIP, Appendix H, P ages H

- 62 to H

- 64

, and SC SIP Narrative, P age 86) :

Appendix H:

During the regional haze SIP development process, the IMPROVE Steering Committee

made recommendation s for a new IMPROVE equation. Among other things, the new equation includes components that take into account the effects of sea salt and site specific Rayleigh scattering with the new IMPROVE equation to determine background

concentrations at the Class I areas. These terms are important components to appropriately consider for South Carolina‟s coastal and several other facilities. Additional discussion of the new IMPROVE equation can be found in Appendix O.51

VISTAS contracted Dr. Ivar Tombach to develo p a post processor to allow CALPOST outputs to be used with the new IMPROVE equation. SC DHEC submitted to U.S. EPA Region 4, a request for approval to use the new IMPROVE equation and postprocessor developed by Dr. Tombach in BART modeling. A discussion o f the rationale for use of the new IMPROVE equation follows. The new IMPROVE postprocessor and instructions are included in the request to EPA for approval of its use in Attachment O.

Rationale for Need for Use of New IMPROVE Equation . The new IMPROVE equation is a much better representation of the effects of particulate matter on light extinction than the old equation and takes into account the latest scientific understanding of several

parameters.

1. The new algorithm overcomes biases of the old algorithm on the haziest days and the clearest days as demonstrated by comparing the measured light extinction from nephelometers at Class I areas to light extinction calculated using each of the equations.

2. The new algorithm recognizes spatial and temporal variation in light extinction as size distribution of the aerosol changes by increasing extinction efficiency as sulfate, nitrate and organics concentrations increase.

3. The new algorithm incorporates a term to reflect the contribution of fine sea salt and its hygroscopic growth with increasing relative humidity recognizing research findings showing that fine sea salt can be an important contributor to light extinction in coastal

areas.

4. The new alg orithm reflects research finding that the mass concentration of particulate organic matter in rural areas is greater than represented by the old equation.

5. The new algorithm includes a NO 2 term to represent times when light absorption by

NO 2 is a meanin gful contributor to light extinction.

6. The new algorithm incorporates site

- specific Rayleigh scattering values to better represent sites close to sea level or with very hot or cold climates.

With this combination of revisions to the IMPROVE equation, t he resulting apportionment of extinction to various components is more accurate on the haziest and clearest days. This is important for the development of emission control strategies since the benefits of control of concentrations of each species will be represented more correctly with the new algorithm.

A majority of South Carolina‟s BART eligible sources are located in coastal areas. The ability to appropriately represent the contribution of sea salt for these sources is important in determining their contribution to haze and evaluating the benefit of potential control strategies. U.S. EPA Region 4, the National Park Service, and the US Fish & Wildlife Service determined that adding site

- specific data to account for the impact of sea52

salt and Rayleigh scattering to the old IMPROVE equation is not appropriate, but rather the entire new IMPROVE equation should be used. The spreadsheet developed by Dr. Tombach to implement the entire new IMPROVE equation for use with CALPUFF contains a modification of CA LPOST that calculates the light extinction from the CALPUFF output. In their review of the spreadsheet and supporting documentation, EPA Region 4 staff commented that the VISTAS methodology contained in the spreadsheet developed by Dr. Tombach appropriatel y implements the features of the new IMPROVE equation, with the exception of the nitrogen dioxide term. EPA Region 4 further stated that with the addition of their recommendation for addressing the NO 2 term, the VISTAS methodology to incorporate the new IM PROVE equation is acceptable on a case

- by

- case basis upon consultation with the EPA Regional Office.

South Carolina‟s request and approval to use the new IMPROVE equation for BART purposes are found in Attachment O

.

From SC SIP Narrative , P age 86:

Sea S alt Term for New IMPROVE equation

7.8.2 Determination of Sources Subject to BART in South Carolina

--
... As approved by EPA (Appendix O.1), SC DHEC is also using the chloride derived IMPROVE default sea salt estimate as the default value for use in the BART assessment for this first planning period. The Regional Haze rule, however, gives the state significant flexibility in making decisions concerning the BART analysis as part of the regional haze process.

VISTAS along with other consultants have examined the effects of sea salt and proposed a hierarchy of methods for sea salt estimation based on a considerati on of different factors impinging on how technically reliable each method is for estimating sea salt in the atmosphere. After taking into account the various method variables as presented in Appendix O.3 (including chlorine depletion and blank problems) S C DHEC is convinced that the use of the VISTAS sodium ion data is justified and provides the most realistic, technically sound, yet reasonably conservative, estimate of sea salt in the Cape Romain Class I Federal area. This September 2002 through December 2004 sodium ion dataset results in a 0.77 ug/m 3 sea salt estimate for the Cape Romain Class I Federal area. As a result, SC DHEC has chosen to accept additional information on a case

- by

- case basis for several BART facilities that have requested a more re fined approach to their BART exemption modeling. While SC DHEC believes that the use of the sodium ion derived alternative sea salt estimate would be justified for any facility modeling visibility impairment at Cape Romain, that refinement is not necessary if a facility exempts with a less refined method.

Table 7.8.2

- 2 presents the facilities who requested an alternative to the default sea salt estimation. Note that some facilities presented data calculated with sea salt estimated by

elemental sodium and that data is included for those facilities.

Table 7.8.2

- 2 New IMPROVE Sea Salt Estimation Methods & BART Visibility53

Impacts

Data Access

– EPA Note: Due to the size of data and modeling files that constitute the BART modeling developed by the sources, the archival and access of this data is made available to the public upon request and is discussed in Appendix I.

EPA Findings: EPA proposes to find that t he State has adequately identified the BART

eligible sources and those sources subject to BART controls. EPA believes that t he State successfully developed and provided the technical analyses to support the BART assessment provision for the non

- CAIR sources. South Carolina opt ed to have CAIR satisfy BART for SO 2 and NO

x for affected CAIR EGUs, as allowed under the Regional Haze regulations. As explained in Section III.C.1

– EPA Findings, the State‟s demonstration regarding CAIR and reasonable progress for EGUs, and other provisi ons in this SIP revision, are based on CAIR and thus, the Agency proposes to issue a limited approval of the State‟s regional haze SIP revision. In a separate action, EPA has proposed a limited disapproval of the South Carolina regional haze SIP because o f deficiencies in the State‟s regional haze SIP submittal arising from the State‟s reliance on CAIR to meet certain regional haze requirements. See 76 FR 82219 (December 30, 2011). EPA is not proposing to take action in this rulemaking on issues associat ed with
South Carolina‟s reliance on CAIR in its regional haze SIP.

CALPUFF MODELING EPA proposes to find that t he CALPUFF 3 modeling system was appropriately applied by SC DHEC in the assessment of visibility impairment in Class I areas for specific sour ces subject to the BART regulations . The BART regulations indicate that CALPUFF or other appropriate models can be used to determine if an individual source is anticipated to cause or contribute to impairment of visibility in Class I areas. T he current r egulatory niche for the CALPUFF modeling system in 40 CFR, p art 51, Appendix W: Guideline on Air Quality Models (Appendix W) is for compliance with non

- attainment New Source Review (N NSR ) / and Prevention of Significant Deterioration ( PSD ) permitting requirements for long range transport (i.e., greater than 50 KM) applications at Class I

3 Note that EPA‟s reference to CALPUFF encompasses the whole CALPUFF modeling system, including CALMET/CALPUFF/CALPOST and other pre and post processors. The different versions of CALPUFF have corresponding versions of CALMET, CALP OST, etc. which may not be compatible with previous versions (e.g., the output from a newer version of CALMET may not be compatible with an older version of CALPUFF). The different versions of the CALPUFF modeling system are available from the model

devel oper on the following website: http://www.src.com/verio/download/download.htm54

areas. There is no preferred model for assessing visibility impact under BART.
However, EPA believes that it is appropriate for the State of South Caroli na to use the CALPUFF modeling system for its BART exemption and control determination modeling.

VISTAS developed a “Protocol for the Application of CALPUFF for BART Analyses.” The final VISTAS BART Modeling Protocol (Revision 3.2, dated Aug. 6, 2006) s tates that VISTAS will use CALPUFF ver. 5.754 and CALMET ver. 5.7 ( i.e. , the VISTAS version of CALPUFF). No formal approval of the CALPUFF VISTAS version (either ver. 5.754 or 5.756) has been made by EPA Region 4. However, there has been an implied accep tance of the VISTAS CALPUFF version as EPA Region 4 has reviewed and commented on the VISTAS BART Modeling Protocol and the source

- specific modeling protocols and reports that were developed by the South Carolina specific sources performing BART modeling. The VISTAS BART modeling protocol underwent an extensive stakeholder development and review process, that involved EPA, FLMs, industrial sources, trade groups, lawyers and other interested parties, be fore the S tate decided to require CALPUFF modeling to evaluate the BART requirements.

The S tate required all BART

- eligible sources to perform BART exemption modeling and to develop source

- specific protocols that complied with the VISTAS protocol. EPA Region 4 provided reviews and comments on the source

- sp ecific protocols and their subsequent exemption modeling reports.

New IMPROVE Equation The CALPUFF model was simulated with the default inputs as recommended in the March 16, 2006 EPA memorandum, “Dispersion Coefficients for Regulatory Air Quality

Model ing in CALPUFF. ” A new methodology was used by the VISTAS s tates to process the mass concentrations from CALPOST (post

- CALPUFF processor) using the new IMPROVE equation so that the BART analyses could consider both the old and new IMPROVE equations. The E PA Headquarters and other EPA r egional o ffices and the Federal Land Managers (FLMs) from the National Park Service and the U.S. Fish and Wildlife Service consulted on the VISTAS innovative approach that was developed to utilize the new IMPROVE equation in the BART assessment and to determine the change in visibility impacts. W hile these other parties were consulted in preparation of EPA Region 4‟s response, the response represented the EPA Region 4 position on the new methodology. Use of the methodology b y BART sources in States located in other EPA Regions would require consultation with the appropriate regional office. EPA required

the State of South Carolina to submit a request to the EPA Region 4 Regional Administrator requesting the use of this new m ethodology for the BART CALPUFF

based modeling. The State submitted a letter dated September 13, 2007, justifying the need for this approach and approval from the Regional Administrator was provided to the

S tate in a letter dated October 5, 2007. The methodology and S tate and Region 4 letters

are located in the S tate‟s SIP submittal

.

The new methodology uses a spreadsheet developed by VISTAS to post

- process the visibility modeling output from the CALPUFF and CALPOST models. The spreadsheet55

implements the new IMPROVE equation for calculating visibility impacts that was adopted by the IMPROVE Steering Committee in December 2005. EPA Region 4 has previously provided comments indicating that new methodology is an alternative

modeli ng approach and should meet the requirements in s ection 3.2 of Appendix W, Guideline on Air Quality Models

, contained in 40 CFR p art 51. EPA reviewed the

S tate‟s rationale for using the new methodology. This demonstration included a rationale

for the nee d to use the new IMPROVE equation, a discussion of the performance of the equation versus measured values, a submittal of the modified post

- processing methodology

, and documentation to support the development of concentrations for the

different terms in th e equation. Based on the demonstration provided in South Carolina‟s September 13, 2007, letter, EPA approved the State‟s request.

Sea Salt and New IMPROVE E quation for BART

EPA proposes to agree with the use of sodium ion (Na + ) concentration data in the new IMPROVE equation for estimating background concentrations in the BART CALPUFF

based modeling. EPA continues to endorse the recommendations made by the IMPROVE Committee for the use of chloride ion data as the default proced ure to estimate sea salt concentration. However, EPA believe s that alternative approaches could

be consi dered on a case

- by

- case basis, which is why EPA agree s with the alternative approach presented by South Carolina for the use of Na + in the BART modelin g. EPA recognize s that a goal of modeling is to find the best method for estimating natural background levels for assessing visibility impacts.

EPA believes that based on our review of the materials presented by SC DHEC and

consultations with Dr. Marc Pi tchford, of the NOAA

- Air Resources Laboratory, that there is a technical basis to support the use of other methods for determining the sea salt concentration for use in the new IMPROVE algorithm. This would be allowable on a

case

- by

- case basis for those coastal Class I areas subject to BART analysis by the South

Carolina sources.

Three of the four facilities that are exempt from BART only if the alternative sodium method is used (i.e., DAK

- Cooper River, MeadWestvaco, and International Paper

Georgetow n), were requested to submit a reasonable progress control analysis so that SC

DHEC c ould assess whether or not controls are reasonable under the r egional h aze regulations . The only facility that has not been requested to submit a reasonable progress

cont rol analysis is an electric generating facility (i.e., Santee Cooper

- Jefferies) covered

under CAIR.

SC DHEC has demonstrated that compliance with CAIR satisfies sources‟ requirements

under the r egional h aze regulations for this first implementation period . In summary, SC

DHEC concluded that additional SO 2 control measures for South Carolina‟s EGUs would not be reasonable to achieve reasonable progress during this first implementation period

. In reaching this decision, SC DHEC considered the four r easonable progress factors set forth in EPA‟s RHR as they apply to the State‟s entire EGU sector. In particular, the State took into account the factors of cost and time necessary for compliance in view of EPA‟s analysis supporting CAIR. Based on the ana lysis, SC DHEC concluded that additional SO 2 control56

measures, beyond those needed to meet CAIR requirements, for South Carolina‟s EGUs would not be reasonable during this first implementation period based on a consideration of the reasonable progress stat utory factors. This conclusion is bolstered by the fact that visibility improvement at the Cape Romain Wilderness Area is projected to exceed the uniform rate of progress in this first implementation period. EPA proposes to find acceptable

South Carolina ‟s methodology and determination that no additional controls beyond CAIR

are reasonable for SO 2 for affected South Carolina EGUs for the first implementation period.

Contribution Threshold With respect to the contribution threshold used in the CALPUFF m odeling, the S tate was also required to justify its choice of the 0.5 dv contribution threshold for exempting sources from BART eligibility. The BART Guidelines state that “the appropriate threshold for determining whether a source „contributes to visibil ity impairment‟ may reasonably differ across states,” but, “[a]s a general matter, any threshold that you use for determining whether a source „contributes‟ to visibility impairment should not be higher

than 0.5 deciviews.” The Guidelines affirm that stat es are free to use a lower threshold if they conclude that the location of a large number of BART

- eligible sources in proximity of a Class I area justifies this approach.

South Carolina used a contribution threshold of 0.5 deciview for determining which sources are subject to BART. SC DHEC concluded that, considering the results of the visibility impacts modeling conducted, a 0.5 deciview threshold was appropriate and a lower threshold was not warranted. South Carolina demonstrated that it is unlikely t hat multiple BART

- eligible sources would simultaneously adversely impact visibility at Cape Romain at a level that would warrant a lower threshold value. For the South Carolina sources that were shown to be impacting the Wolf Island Class I Federal area i n Georgia, South Carolina demonstrated that they were located far from Wolf Island and that the majority of the individual BART

- eligible sources had visibility impacts well

below 0.5 deciview.

EPA proposes to agree with the S tate‟s rationale for choosin g this threshold value since there are a limited number of in and out of state sources that impact the various Class I areas in the State. In addition there are a limited number of sources in close proximity to each of the Class I areas. Considering resu lts of the visibility impacts modeling conducted (see SC SIP, Appendix H.6), a 0.5 dv threshold was appropriate and a lower threshold was not warranted since the majority of the visibility impacts were well below 0.5 deciview. Also, even though several so urces impacted each Class I area, the overall impacts were low from the BART sources, and EPA has not made any adverse comments

on the use of the CALPUFF VISTAS versions.

References used in the EPA review:

1. 40 CFR p art 5 1 , Appendix W: Guideline on Air Quality Model s.

2. October 5, 2007

, letter from James I. Palmer, Regional Administrator, US EPA Region 4, to Robert W. King, Jr., P.E

, Deputy Commissioner, South Carolina5 7 Department of Health and Environmental Control , Approval for the use of the

VISTAS met hodology for use of the New IMPROVE equation with CALPUFF

model results.

3. 40 CFR part 51, Appendix Y : Guidelines for BART Determinations Under the Regional Haze Rule

4. IWAQM. 1998. Interagency Workgroup on Air Quality Modeling (IWAQM) Phase 2 Summary Rep ort and Recommendations for Modeling Long

- Range Transport and Impacts on Regional Visibility. EPA

- 454/R

- 98

- 019. U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC.

5. VISTAS, 2006. Tombach, I., P. Brewer, T. Rogers, and C. Arrington, Protocol for the Application of the CALPUFF Model for Analysis of Best Available Retrofit Technology (BART) Revision 2

– 3/9/06 developed through consultation with EPA, the FLMs, VISTAS state and local Agencies and industry stakeholders VISTAS, 2006. Tombach, I., P. Brewer, T. Rogers, and C. Arrington

. Located at http://www.vistas

sesarm.org/documents/BARTModelingProtocol_rev3.2_31Aug06.pdf

.

6. March 16, 2006

, EPA memo randum from Dennis Atkinson to Kay T. Prince on Dispersion Coefficients for Regulatory Air Quality Modeling in CALPUFF

.

7. Additional Regional Haze Questions, EPA, September 27, 2006 Revision. Answers to questions that PA received from various States and Regional Planning Organizations (RPOs) related to the submission of regional haze SIPs under the program describe d by 40 CFR 51.308. This document provides guidance to the State air pollution control agencies and the general public on meeting the regional haze SIP requirements.58

III. Evaluation of Regional Haze SIP Submittal

D . Best Available Retrofit Technology (BART) Requirements

D.3. Identification of Sources Addressed by CAIR : States which adopt the CAIR cap and trade program for SO 2 and NOx are allowed to apply CAIR controls as a substitute for controls required under BART. The SIP should include a list of all BART

- eligible sources within the State for which the CAIR rule is being applied.

State Regional Haze Submittal

SC SIP Narrative , Page 86:

Six of South Carolina‟s BART

- eligible sources are EGUs. EPA has determined that, as a whole, the CAIR cap

- and

- t rade program will improve visibility more than implementing BART for individual sources in states which participate in the federal CAIR program. A state that opts to participate in the CAIR program need not require affected BART eligible EGUs to install BA RT for SO 2 or NO X emissions. Given that South Carolina is participating in CAIR and accepts EPA‟s overall finding that CAIR “substitutes” for BART for SO 2 and NO X , SC ‟s EGUs were allowed to submit BART exemption modeling demonstrations for PM emissions only. Four of the six EGUs demonstrated that they do not contribute to visibility impairment in South Carolina‟s Class I Federal area. These facilities were SCE&G

– Cana dys plant and Santee Cooper‟s

– Jefferies, Winyah, and Grainger facilities.

EPA Findings : EPA proposes to find that South Carolina has adequately addressed this provision . EPA believes that t he State has appropriately identified the BART

- eligible

sources and those sources subject to BART controls. South Carolina opted to have CAIR satisfy BART for SO 2 and NO

x for affected CAIR EGUs, as allowed under the Regional Haze regulations. A s explained in Section III.C.1

– EPA Findings, the State‟s

demonstration re garding CAIR and reasonable progress for EGUs, and other provisions in this SIP revision, are based on CAIR and thus, the Agency proposes to issue a limited approval of the State‟s regional haze SIP revision. In a separate action, EPA has proposed a limit ed disapproval of the South Carolina regional haze SIP because of deficiencies in the State‟s regional haze SIP submittal arising from the State‟s reliance on CAIR to meet certain regional haze requirements. See 76 FR 82219 (December 30, 2011). EPA is no t proposing to take action in thi s rulemaking on issues associated with
South Carolina‟s reliance on CAIR in its regional haze SIP.59

III. Evaluation of Regional Haze SIP Submittal

D . Best Available Retrofit Technology (BART) Requirements

D.4. Source Sp ecific BART Determinations: For each BART

- eligible source in the State subject to BART, a determination of BART based on an analysis of the best system of continuous emission control technology available and associated emission reductions

achievable (unle ss the State demonstrates that an emissions trading program or other alternative will achieve greater reasonable progress toward natural visibility conditions). To address the requirements for BART, the State must take into consideration the “Five

Factors” from 51.308(e)(1)(ii)(A): (1) the technology available, (2) the costs of compliance, (3) the energy and non

- air quality environmental impacts of compliance, any pollution control equipment in use at the source, (4) the remaining useful life of the

source , and (5) the degree of improvement in visibility that may reasonably be anticipated to result from the use of such technology.

State Regional Haze Submittal

SC SIP Narrative , Pages 86

- 88:

SCE&G Wateree: SCE&G Wateree Station is located in Eastover, South Carolina. The station consists of two identical pulverized coal

- fired, wet bottom boilers. The two boilers produce superheated steam, which is used in the two dedicated turbine generators Units 1 and 2 are equipped with fabric filter baghouses to con trol PM emissions, and low

- NO X burners and SCR to control NO X emissions. Although Units 1 and 2 commenced commercial operation in the early „70s, there is no near

- term limitation on the useful life of this unit.

SCE&G also plans to install two wet limest one scrubbers to control SO 2 emissions in the summer (July/August) of 2009. Wateree Station Units 1 and 2 will be retrofitted with a flue gas desulfurization (FGD) system using a limestone slurry in a spray tower to

remove SO 2 from the gas stream. Although designed to control SO 2 emissions, the FGD system will provide the added benefit of removing sulfates, a principal constituent of

condensable PM

10 . Installing a FGD system will result in added improvements in visibility impairment attributable to Units 1 and 2.

The installation of the FGD systems will result in a visibility improvement of about 59 percent, in terms of delta dv relative to natural conditions, on the worst

- case visibility day. Furthermore, as shown in Table 7.8.2

- 1 above, the 98 th percentile delta dv resulting from the installation of the FGD systems is well below the 0.5 delta dv threshold, used to determine whether a source contributes to visibility impairment as stated in the BART Guidelines. In addition, an analysis of annualize d costs associated with additional PM 10 control options determined that any additional control measure is not cost effective in terms of visibility improvements.

SCE&G Williams: South Carolina Electric & Gas (SCE&G) Williams Station is located

in Goose Cr eek, South Carolina. The station consists of a single pulverized coal

- fired, dry bottom boiler. The boiler produce superheated steam, which is used in a turbine generator. Although Unit 1 commenced commercial operation in 1973, there is no near60

term limitation on the useful life of this unit

. Unit 1 is currently equipped with low

- NO X burners and SCR to control NO X emissions and an electrostatic precipitator (ESP) to

control PM

10 emissions, the later of which has been demonstrated to achieve performance levels comparable to those being specified as BACT for new coal

- fired boilers. The existing control device, therefore, is considered representative of BART for PM 10.

In October 2009, SCE&G plans to retrofit Williams Station Unit 1 with a FGD system using a limestone slurry in a spray tower to remove SO 2 from the gas stream. Although designed to control SO 2 emissions, the FGD system will provide the added benefit of removing sulfates, a principal constituent of condensable PM 10 . PM 10 emissions will be reduced from 925 tpy to 464 tpy following the installation of the FGD system. This 50 percent reduction is attributable to the removal of condensable PM 10 , principally sulfates, in the FGD system. The installation o f the FGD system will result in a visibility improvement of about 35 percent, in terms of delta dv relative to natural conditions, on

the worst

- case visibility day. Furthermore, the 98 th percentile delta dv resulting from the installation of the FGD system is only slightly above the 1.0 delta dv threshold (2 occurrences in 3 years), used to determine whether a source could causes visibility impairment as stated in the BART Guidelines. The installation of any of the PM 10 control options will only result in a n additional visibility improvement of less than 1 percent on

the worst

- case visibility day. Furthermore, the annual costs associated with the PM 10 control options are not cost effective in terms of visibility improvements.

76BU EPA Findings : EPA propos es to find that South Carolina has adequately addressed this provision . EPA believes that t he State appropriately documented the technical analysis to

assess the need for and implementation of BART controls as applicable for those non

CAIR EGU emission units of PM 10
, SO 2 and NOx precursor emissions. This involved identification of existing controls on applicable emission units, potential control options for applicable emission precursors, and the successful application of the f ive f actors to
determine t he feasibility of controls that constituted BART.61

III. Evaluation of Regional Haze SIP Submittal

D . Best Available Retrofit Technology (BART) Requirements

D.5. Enforceability of BART: For each BART

- eligible source in the State subject to BART, the SIP should include emission limitations representing BART and schedules for compliance with BART. For each BART

- eligible source in the State subject to BART,

the SIP must include a requirement that each source subject to BART be required to install and op erate BART as expeditiously as practicable, but in no event later than five years after approval of the implementation plan revision and a requirement that each source subject to BART maintains the control equipment required by this subpart and

establishes procedures to ensure such equipment is properly operated and maintained.

State Regional Haze Submittal SC SIP Appendix H , Page H

- 65:

EPA Findings : EPA proposes to find that South Carolina has adequately addressed this provision. SC DHEC determined that two SCE&G facilities, Williams and Wateree

, did

not model out of BART. Both these facilities installed fluidized gas desulphurization

SO 2 controls in order to comply with CAIR . These additional SO 2 controls will also provide PM 10 reductions. SC DHE C has included these controls in the applicable t itle V permits.62

III. Evaluation of Regional Haze SIP Submittal

E

. Coordination of Regional Haze and RAVI Requirements The State must revise its plan to provide for review and revision of a coordinated lon g

term strategy for addressing reasonably attributable and regional haze visibility impairment

.

State Regional Haze Submittal

South Carolina did not explicitly address this provision but it has updated and addressed

all relevant provisions:

Monitoring ( SC SIP Narrative , P ages 109

- 111) : The primary monitoring network for regional haze, both nationwide and in South Carolina, is the IMPROVE network. Given that IMPROVE monitoring data from 2000

- 2004 serve as the baseline for the regional haze program, the f uture regional haze monitoring strategy must necessarily be based on, or directly comparable to, IMPROVE. The IMPROVE measurements provide the only long

- term record available for tracking visibility improvement or degradation and therefore South Carolina i ntends to rely on the IMPROVE network for complying with the regional haze monitoring requirement in the Regional Haze Rule.

There is currently one IMPROVE site in the South Carolina, representing the Cape Romain National Wildlife Refuge Class I Federal a re a (ROMA1). The State supplement the IMPROVE sampling by operating additional co

- located monitoring. Monitoring at Cape Romain includes:

• A Tapered Element Oscillating Microbalance (TEOM) for continuously measuring

PM 2.5 mass concentration;

• An Aethalom eter for continuously measuring Black Carbon;

• An integrating nephelometer, supported by VISTAS, for continuously measuring light scattering; and

• Continuous monitoring of NO2 and SO2 precursor gasses. The Optec NGN

- 2 Nephalometer has been transferred to South Carolina. The operation and data reporting is supported by VISTAS through 2008. Funding will be sought to continue operation but is not assured

. Additional haze

- related measurements were made in South Carolina in 2002

- 2005 a s part of special monitoring studies by the VISTAS regional planning organization. These

studies were intended to better understand source contributions to PM 2.5 mass and visibility. They included continuous monitoring of sulfat e, nitrate, and carbon to be tter understand daily trends in PM 2.5 , detailed analyses of carbon collected on high volume filters to identify source contributions to carbon, and additional analyses of sodium and ammonium on IMPROVE filter samples. Funding does not exist to continue the se special studies; however, the equipment has been transferred to SC DHEC.

South Carolina has acquired several continuous sulfate monitors and expects to operate

t them at urban and rural sites to further the understanding of both PM 2.5 and visibility63

for mation and trends in South Carolina. SC DHEC will operate the units discussed above as long as funds allow.

In addition, SC DHEC operates a fairly comprehensive PM 2.5 network of the filter based Federal Reference Method samplers, continuous mass monitors (TEOMs), STN protocol filter based speciated samplers and the continuous speciated particulate monitors

described above. These PM 2.5 measurements help SC DHEC characterize air pollution levels in areas across the state, and therefore aid in the analysis of visibility improvement

in and near the Class I areas.

The IMPROVE measurements are central to South Carolina‟s regional haze monitoring strategy, and it is difficult to visualize how the objectives listed above could be met without the monitoring provide d by IMPROVE. Any reduction in the scope of the IMPROVE network in South Carolina and neighboring Class I Federal areas would jeopardize the State‟s ability to demonstrate reasonable progress toward visibility improvement in its Class I areas and plan for appropriate future progress. In particular, South Carolina‟s regional haze strategy relies on emission reductions that will result from the CAIR and reductions in neighboring States, which occur on different time scales

and will most likely not be spatiall y uniform. Monitoring a t representative Class I area is important to document the different air quality responses to the emissions reductions.

Because the current IMPROVE monitor at Cape Romain represents a unique Class I Federal area, and a significant component of the contributions are regional, the

reduction of the IMPROVE network by shutting down the existing IMPROVE site or any

the closer IMPROVE monitoring sites impedes tracking the progress or planning improvements at Cape Romain. In the event the Cape Romain monitoring is scheduled for elimination, South Carolina, in consultation with the US EPA and relevant FLMs, will develop an alternative approach for meeting the tracking goal, perhaps by seeking contingency funding to carry out limited monitori ng or by relying on data from nearby

urban monitoring sites to demonstrate trends in speciated PM 2.5 mass.

Data produced by the IMPROVE monitoring network will be used nearly continuously for preparing the five

- year progress reports and the 10

- year SIP re visions, each of which relies on analysis of the preceding five years of data. Consequently, the monitoring data from the IMPROVE sites needs to be readily accessible and to be kept up to date. Presumably, IMPROVE will continue to process information from its own measurements at about the same pace and with the same attention to quality as it has shown in the

recent past. The VIEWS web site has been maintained by VISTAS and the other Regional Planning Organizations to provide ready access to the IMPROVE dat a and data analysis tools. South Carolina is encouraging VISTAS and the other RPOs to maintain VIEWS or a similar data management system to facilitate availability analysis of the IMPROVE and visibility related data.

Periodic Submittals ( SC SIP Narrative

, P age 116) : 40 CFR Section 51.308(f) requires South Carolina to revise its regional haze SIP and submit a plan revision to EPA by July 31, 2018, and every ten years thereafter. In64

accordance with the requirements listed in Section 51.308(f) of the RHR, Sou th Carolina commits to revising and submitting this regional haze SIP by July 31, 2018, and every ten years thereafter.

In addition, Section 51.308(g) requires periodic reports evaluating progress towards the RPGs established for each mandatory Class I ar ea. “The EPA believes that a requirement for regular SIP revisions will result in a more effective program over time and provide a focus for demonstrating ongoing progress and making mid

- course corrections in emission strategies” (62 FR 41151).

In accorda nce with the requirements listed in Section 51.308(g) of the RHR, South Carolina commits to submitting a report on reasonable progress to EPA every five years following the initial submittal of the SIP. The report will be in the form of a SIP revision.

The reasonable progress report will evaluate the progress made towards the RPG for each mandatory Class I Federal area located within South Carolina and in each mandatory Class I Federal area located outside South Carolina that may be affected by emissions fr om South Carolina sources

.

EPA Findings : EPA proposes to find that South Carolina has adequately addressed this provision. Under EPA‟s RAVI regulations, the RAVI portion of a state SIP must address any integral vistas identified by the FLMs pursuant to 40 CFR 51.304. See 40 CFR

51.302. An integral vista is defined in 40 CFR 51.301 as a “view perceived from within

the mandato ry Class I federal area of a specific landmark or panorama located outside the boundary of the mandatory Class I federal area.” Visibility in any mandatory Class I area includes any integral vista associated with that area. The FLMs did not identify any integral vistas in South Carolina. In addition, the Class I area in South Carolina is not experiencing RAVI, nor are any of its sources affected by the RAVI provisions. Thus, the December 17, 2007, South Carolina regional haze SIP submittal does not expl icitly address the two requirements regarding coordination of the regional haze with the RAVI LTS and monitoring provisions. South Carolina has, however, previously made a commitment to address RAVI should the FLM certify visibility impairment from an

ind ividual source. 4 EPA proposes to find that this regional haze submittal appropriately supplements and augments South Carolina‟s RAVI visibility provisions to address regional haze by updating the monitoring and LTS provisions as summarized below in

this s ection.

In the December 17, 2007, submittal, SC DHEC updated its visibility monitoring program and developed a LTS to address regional haze. Also in this submittal, SC DHEC affirmed its commitment to complete items required in the future under EPA‟s

RHR. Specifically, SC DHEC made a commitment to review and revise its regional haze implementation plan and submit a plan revision to EPA by July 31, 2018, and every 10 years thereafter. See 40 CFR 51.308(f). In accordance with the requirements listed in 40 CFR 51.308(g) of EPA‟s regional haze regulations and 40 CFR 51.306(c) of the RAVI

4 South Carolina submitted its visibility SIP revision s address ing RAVI on June 3, 1985, which EPA approved on January 21, 1986 (51 FR 2698).65

LTS regulations, SC DHEC made a commitment to submitting a report to EPA on progress towards the RPGs the mandatory Class I area located within South Carolina and

in each ma ndatory Class I area located outside South Carolina which may be affected by emissions from within South Carolina. The progress report is required to be in the form of a SIP revision and is due every five years following the initial submittal of the regio nal

haze SIP. See 40 CFR 51.308(g). Co nsistent with EPA‟s monitoring regulations for RAVI and regional haze, South Carolina will rely on the IMPROVE network for compliance purposes, in addition to any RAVI monitoring that may be needed in the

future. See 40 CFR 51.305, 40 CFR 51.308(d)(4). Also, the South Carolina new source review rules, previously approved in the State‟s SIP, continue to provide a framework for review and coordination with the FLMs on new sources which may have an adverse impact on visibility in either form (i.e., RAVI and/or regional haze) in any Class I area. The original South Carolina visibility SIP submitted to EPA June 3, 1985, addressing the monitoring and LTS requirements in 40 CFR 51.305 and 40 CFR 51.306, respectively,

wa s supplemented by an EPA regulation, 40 CFR 52.2132, on July 12, 1985 (50 FR 28544), as amended on November 24, 1987 (52 FR 45132). The 1985 and 1987 EPA actions incorporate 40 CFR 52.26 and 40 CFR 52.29 into the South Carolina SIP and

continue to be in e ffect. Because the December 17, 2007, regional haze submittal appropriately addresses the monitoring and LTS requirements in 40 CFR 51.305 and 40 CFR 51.306, and supersedes these previous requirements, EPA is proposing to rescind the federal regulations i n 40 CFR 52.2132 and rely on the provisions in this December 17, 2007, submittal to meet these requirements.66

III. Evaluation of Regional Haze SIP Submittal

F

. Monitoring Strategy and Other Implementation Requirements

Monitoring Strategy: The SIP must i nclude a monitoring strategy for measuring, characterizing, and reporting of regional haze visibility impairment that is representative of all mandatory Class I Federal areas within the State and/or summarize monitoring strategy of s tates with affected mandatory Class I Federal areas . Compliance with this requirement may be met through participation in the Interagency Monitoring of Protected Visual Environments (IMPROVE) network.

Other Requirements: The implementation plan must also provide for the fol lowing:

A. The establishment of any additional monitoring sites or equipment needed to assess whether reasonable progress goals to address regional haze for all mandatory Class I Federal areas within the State are being achieved.

B. Procedures by which monitorin g data and other information are used in determining the contribution of emissions from within the State to regional haze visibility impairment at mandatory Class I Federal areas both within and outside

the State.

C. The reporting of all visibility monitoring data at least annually for each mandatory Class I Federal area in the State. To the extent possible, the State should report monitoring data for visibility electronically and use of the Visibility Information Exchange Web System (VIEWS) is encouraged.

D. Oth er elements, including reporting, recordkeeping, and other measures, necessary to assess and report on visibility.

State Regional Haze Submittal SC SIP Narrative, Pages 109

- 111 :

The primary monitoring network for regional haze, both nationwide and in So uth Carolina, is the IMPROVE network. Given that IMPROVE monitoring data from 2000

- 2004 serve as the baseline for the regional haze program, the future regional haze monitoring strategy must necessarily be based on, or directly comparable to, IMPROVE.

The IMPROVE measurements provide the only long

- term record available for tracking visibility improvement or degradation and therefore South Carolina intends to rely on the IMPROVE network for complying with the regional haze monitoring requirement in the Regional Haze Rule. There is currently one IMPROVE site in the South Carolina, representing the Cape Romain National Wildlife Refuge Class I Federal area (ROMA1). The State supplements the IMPROVE sampling by operating additional co

- located monitoring. Mon itoring at Cape Romain includes:

• A Tapered Element Oscillating Microbalance (TEOM) for continuously measuring

PM 2.5 mass concentration;

• An Aethalometer for continuously measuring Black Carbon;

• An integrating nephelometer, supported by VISTAS, for co ntinuously measuring light scattering; and

• Continuous monitoring of NO2 and SO2 precursor gasses.67

The Optec NGN

- 2 Nephalometer has been transferred to South Carolina. The operation and data reporting is supported by VISTAS through 2008. Funding will be s ought to continue operation but is not assured.
Additional haze

- related measurements were made in South Carolina in 2002

- 2005 as

part of special monitoring studies by the VISTAS regional planning organization. These

studies were intended to better understa nd source contributions to PM 2.5 mass and visibility. They included continuous monitoring of sulfate, nitrate, and carbon to better understand daily trends in PM 2.5 , detailed analyses of carbon collected on high volume filters to identify source contributi ons to carbon, and additional analyses of sodium and ammonium on IMPROVE filter samples. Funding does not exist to continue these special studies; however, the equipment has been transferred to SC DHEC. South Carolina has acquired several continuous sulfa te monitors and expects to operate them at urban and rural sites to further the understanding of both PM 2.5 and visibility formation and trends in South Carolina. SC DHEC will operate the units discussed above as long as funds

allow. In addition, SC DHEC operates a fairly comprehensive PM 2.5 network of the filter based Federal Reference Method samplers, continuous mass monitors (TEOMs), STN protocol filter based speciated samplers and the continuous speciated particulate monitors

described above. These PM 2.5 measurements help SC DHEC characterize air pollution levels in areas across the state, and therefore aid in the analysis of visibility improvement

in and near the Class I areas. The IMPROVE measurements are central to South Carolina‟s regional haze mon itoring strategy, and it is difficult to visualize how the objectives listed above could be met without the monitoring provided by IMPROVE. Any reduction in the scope of the IMPROVE network in South Carolina and neighboring Class I Federal areas would jeo pardize the State‟s ability to demonstrate reasonable progress toward visibility improvement in its Class I areas and plan for appropriate future progress. In particular, South Carolina‟s regional haze strategy relies on emission reductions that will resu lt from the CAIR and reductions in neighboring States, which occur on different time scales

and will most likely not be spatially uniform. Monitoring at representative Class I area is important to document the different air quality responses to the emissio ns reductions. Because the current IMPROVE monitor at Cape Romain represents a unique Class I Federal area, and a significant component of the contributions are regional, the

reduction of the IMPROVE network by shutting down the existing IMPROVE site or an y the closer IMPROVE monitoring sites impedes tracking the progress or planning improvements at Cape Romain. In the event the Cape Romain monitoring is scheduled for elimination, South Carolina, in consultation with the US EPA and relevant FLMs, will devel op an alternative approach for meeting the tracking goal, perhaps by seeking contingency funding to carry out limited monitoring or by relying on data from nearby urban monitoring sites to demonstrate trends in speciated PM 2.5 mass. Data produced by the IM PROVE monitoring network will be used nearly continuously for preparing the five

- year progress reports and the 10

- year SIP revisions, each of which relies on analysis of the preceding five years of data. Consequently, the monitoring data from the IMPROVE s ites needs to be readily accessible and to be kept up to date. Presumably, IMPROVE will continue to process information from its own measurements68

at about the same pace and with the same attention to quality as it has shown in the

recent past. The VIEWS web site has been maintained by VISTAS and the other Regional Planning Organizations to provide ready access to the IMPROVE data and data analysis tools. South Carolina is encouraging VISTAS and the other RPOs to maintain VIEWS or a similar data management system to facilitate availability analysis of the IMPROVE and visibility related data.

EPA Findings : EPA proposes to find that S outh C arolina has adequately addressed this provision.69

III. Evaluation of Regional Haze SIP Submittal

G

. Emission Inventor y (40 CFR 51.308(d)(4)(v) (See also TSD Section III.C.) )

The SIP must include a statewide inventory of emissions of pollutants that are reasonably anticipated to cause or contribute to visibility impairment in any mandatory Class I

Federal area within the S tate . The inventory must include emissions for a baseline year, emissions for the most recent year for which data are available, and estimates of future projected emissions

, and a commitment to update the inventory periodically.

State Regional Haze Submittal SC SIP Narrative, Pages 29

- 30:

Section 51.308(d)(4)(v) of the RHR requires a statewide emissions inventory of pollutants that are reasonably anticipated to cause or contribute to visibility impairment in any mandatory Class I Federal area. An in ventory was developed for the baseline year 2002 and estimated for 2009 and 2018. The pollutants inventoried include VOCs, nitrogen oxides (NO X

), fine particulate (PM 2.5 ), coarse particulate (PM 10 ), ammonia, and SO 2 . In general, the baseline emissions inventory for 2002 was developed using control information for South Carolina. A complete detailed discussion of the baseline emissions inventory is contained in Appendix D.3. There are five different emission inventory source classifications, stationary p oint and area sources, off

- road and on

- road mobile sources, and biogenic sources. Stationary point sources are those sources that emit greater than a specified tonnage per year and

the data is provided at the facility level. Stationary area sources are tho se sources whose emissions are relatively small but due to the large number of these sources, the collective emissions could be significant (e.g., dry cleaners, service stations, etc.) These types of emissions are estimated on the county level. Off

- road mo bile sources are equipment that can move but do not use the roadways (e.g., lawn mowers, construction equipment, railroad locomotives, aircraft, etc.). The emissions from these sources, like stationary area sources, are estimated on the county level. On

- ro ad mobile sources are automobiles, trucks, and motorcycles that use the roadway system. The emissions from

these sources are estimated by vehicle type and road type and are summed to the county

level. Biogenic sources are natural sources like trees, crops , grasses, and natural decay of plants. The emissions from these sources are estimated on a county level. In addition to the various source classifications, there are also various types of emission inventories. The first is the actual base year inventory. This inventory is the base year emissions that correspond to the meteorological data; for this modeling effort it is 2002. These emissions are used for evaluating the air quality model performance. The second type of inventory is the typical base year inve ntory. This inventory is similar to the actual base year; however, for sources that may have significant changes from

year to year, a more typical emission value is used. In this modeling effort, typical

emissions were developed for the EGUs and the wildla nd fire emissions. The air quality modeling results using these emissions are used in calculating the relative reduction factors used in the attainment demonstration test. The detailed discussions of the emissions inventory development can be found in Appe ndices D.1 and D.4.c.70

SC SIP Narrative , Page 33:

SC SIP Narrative , Pages 57

- 59:

The Base G inventories for 2009 and 2018 account for (post

- 2002) emission reductions from promulgated and proposed federal, state, local, and site

- specific control programs

as of July 1, 2004. In general, emissions inventories were developed for 2009 and 2018

u sing current control information in South Carolina: the 2002 inventory was grown using EGAS6, MOBILE6, and IPM for EGUs. For EGUs, IPM results were adjusted ba sed on State and local (S/L) agency knowledge of planned emission controls at specific EGUs. For non

- EGUs, we used recently updated growth and control data consistent with the data used in EPA‟s CAIR analyses supplemented by S/L agency data and updated for ecasts from the Department of Energy (DOE). Area source controls were estimated using known state

- level Stage I controls on gasoline dispensing facilities and open burning estimates, as well as controls used to project emissions for EPA‟s Heavy Duty Diesel rulemaking and for the CAIR rulemaking. Mobile source controls included local controls underlying the 2002 baseline inventory (vehicle emission inspection, Stage II vapor recovery, anti

- tampering, etc.) with changes based on specific State input. Non

- road control data and projections for 1996, 2010, 2015, and 2020 were obtained from the EPA's CAIR Technical Support Document, and straight line projections were used to estimate 2009 and 2018 levels. The following bar charts show expected decreases in emissio ns of SO 2 and NO X across the VISTAS states from 2002 through 2018. (Similar charts for other visibility impairing pollutants are contained in Appendix H.5). Note that for SO 2 in particular, which is the largest contributor to haze in the VISTAS region, emi ssions are expected to decrease dramatically between 2002 and 2018. However, EGU emissions will remain the largest contributor, comprising more than half of remaining SO 2 emissions in every state.

56B Table 7.2.3

- 1 is a summary of the 2009 Base G2emission inventory. The complete inventory and discussion of the methodology is contained in Appendix D.2 (a, b, and c).71

Table 7.2.3

- 2 is a summary of the 2018 Base G2 emission inventory. The complete inventory and discussion of the methodology is contained in Appendix D. 2 (a, b, and c).

SC SIP Narrative, Page 117:

All requirements listed in 51.308(g) shall be addressed in the SIP revision for reasonable

progress. More specifically, the initial 5

- year Progress Report (due in 2013) will examine the effect of emission reductions as well as seek to evaluate the effectiveness of emission management measures implemented. Therefore this Report will provide for a comparison of emission inventories, ultimately expressing the change in visibility for the most impaire d and least impaired days over the past five years. Appendix K references recommendations to consider when performing mid

- course reviews. Moreover, due to the uncertainty of some measures, this Progress Report will also provide SC DHEC the opportunity to e valuate the overall effectiveness of proposed measures to reduce visibility impairment to include the effect of state and federal measures such as CAIR.

EPA Findings : EPA proposes to find that South Carolina has adequately addressed this provision.72

I V. Conclusion

EPA is proposing a limited approval of a revision to the South Carolina SIP submitted by the State of South Carolina on December 17, 2007 , as meeting some of the applicable regional haze requirements as set forth in sections 169A and 169B of the CAA and in 40

CFR 51.300

- 308, as described previously in this action. Also in this action, EPA is proposing to rescind the federal regulations in 40 CFR 52.2132 that were approved into the South Carolina SIP on July 12, 1985, and November 24, 1987, a nd to rely on the provisions in South Carolina‟s December 17, 2007 , SIP revision to meet the monitoring and LTS requirements for RAVI.