1



# Technical Support Document for

North Carolina Regional Haze SIP Submittal

January 2012

U.S. EPA

– Region 4 Atlanta, GA2 

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

Table of Contents

I. Background

II. Summary of EPA’s Action

III. Evaluation of State Regional Haze Submittal

A. Identification of Areas

B. Reasonable Progress Goals 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

1. Technical Basis for Strategy

2. Identification of Sources and Factors to be Considered

3. Source or Source Category Specific Analyses for Reasonable Progress

4. Enforceability 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 Rule ( CAIR )

4. Source Specific BART Determ inations

5. Enforceability of BART

E. Coordination of Regional Haze and RAVI Requirements

F. Monitoring Strategy and Other Implementation Requirements

G. Emission Inventory

IV. Conclusion

__________________________________________________________________ Note : Italicized text in this document that appears under the “State Regional Haze Submittal” headings are excerpts from relevant portions of the North Carolin a regional haze submittal as cited. Figure and table citations under these headings reflect the actual reference s as listed in the State’s SIP submittal. Page numbers refer to the SIP Narrative, unless otherwise specified.3 

### TSD for North 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 visibility 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 wilderness 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

attributable” 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, modeling and scient ific 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 Regional Haze rules. The r egional h aze rule (RHR) that EPA 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 are 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 r egional h aze SIP to EPA

with in three years after the date of designation of areas under the National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM2.5) . EPA promulgated PM2.5 designations on December 17, 2004, and thus, regional haze SIPs were to be submitted to EPA by December 17, 2007, which is also specified at 40 CFR 51.308(b).

The RH R addressed the combined visibility effects of various pollution sources over a wide geographic region. Consequently, all 50 states , including those without Class I areas

, Wa shington, D.C., and the Virgin Islands, are required to submit Regional Haze SIPs. 40 CFR 51.300(b)(3). EPA designated five Regional Planning Organizations (RPOs) to assist with the coordination and cooperation needed to address the visibility 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

E astern B and of the Cherokee Indians , other Federally Rec ognized 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 North Carolina through the No rth Carolina Division of Air Quality ( NC DAQ) chose to participate in VISTAS to develop the technical analyses needed to fulfill the requirements of

the RH R.4 Figure 1. Geographical Areas of Regional Planning Organizations

Figure 2 . Class I Areas in the VISTAS Region5

II. Summary of Action

EPA is proposing a limited approval of a revision to the North Carolina state implementation plan (SIP) submitted by the State of North Carolina through the North Carolina Department of Environment and Natural Resources, Division of Air Quality (NCDAQ), on December 17, 2007, that addresses regional haze for the first implementation period. This revision addresses the requirements of the Clean Air Act (CAA) and EPA’ s rules that require states to prevent any future and remedy any existing anthropogenic impairment of visibility in mandatory Class I areas (national parks and wilderness areas) caused by emissions of air pollutants from numerous

sources located over a wid e geographic area (also referred to as the “regional haze program”). States are required to assure reasonable progress toward the national goal of achieving natural visibility conditions in Class I areas. EPA is proposing a limited approval of this SIP r evision to implement the regional haze requirements for North Carolina on the basis that the revision, as a whole, strengthens the North Carolina SIP. In a separate action, EPA has proposed a limited disapproval of the North Carolina regional haze SIP bec ause of deficiencies 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 State Regional Haze 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

NC SIP Narrative , Page 4:

North Carolina has five mandatory Class I Federal areas within its borders. These are Grea t Smoky Mountains National Park; Joyce Kilmer

- Slickrock Wilderness Area; Linville Gorge Wilderness Area, Shining Rock Wilderness Area; and Swanquarter Wildlife Refuge.

The North Carolina Division of Air Quality (NCDAQ) in the North Carolina Departmen t of Environment and Natural Resources is responsible for developing the Regional Haze SIP. The Great Smoky Mountains and Joyce Kilmer

- Slickrock are located in both Tennessee and North Carolina. For the Great Smoky Mountains, both states are sharing the le ad for setting goals and for Joyce Kilmer

- Slickrock, North Carolina is the lead.

Figure 3 . North Carolina’s Class I areas

EPA Findings : EPA proposes to find that N orth C arolina has adequately addressed this provision.7

III. Evaluation of Regional Haze Submittal

B

. Reas onable Progress Goals 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 impaired and least impaired days (i.e. the 20% most impaired days and 20% least imp aired 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 natu ral 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 consul tation with

EPA.

State R egional H aze Submittal

NC SIP Narrative , Page 9:

Baseline visibility conditions at each North Carolina Class I area are estimated using sampling data collected at IMPROVE monitoring sites at four of the five Class I areas in North Carolina. A five

- year average (2000 to 2004) was calculated for each of the 20% worst and 20% best visibility days in accordance with 40 CFR 51.308(d)(2) and Guidance for Tracking Progress Under the Regional Haze Rule , EPA

- 454

- 03

- 004, September, 2003

. IMPROVE data records for Great Smoky Mountains and Linville Gorge for the period 2000 to 2004 meet the USEPA requirements for data completeness (75 percent for the year and 50 percent for each quarter). Shining Rock and Swanquarter had missing data in mo re than one year from 2000 to 2004. Data records for these sites were filled using data substitution procedures outlined in Appendix B.1. IMPROVE does not operate a monitor at Joyce Kilmer Wilderness and considers the IMPROVE monitor at Great Smoky Mountains to be representative of visibility in the Joyce Kilmer area. The light extinction and deciview visibility values for the 20% worst and 20% best visibility days at the Class I areas are based on data and calculations included in Appendix B.1 of th e SIP

submittal.8

Figure 4. Baseline Visibility Conditions for North Carolina Class I Areas (2002

- 2004)

EPA Findings : EPA proposes to find that N orth C arolina has adequately addressed this provision. EPA proposes to concur that the use of data from the Great Smoky Mountains IMPROVE site is appropriate for establishing baseline conditions for the Joyce Kilmer

– Slickrock wilderness area. Class I area Average for

20% Worst Days (deciviews) Average for

20% Best Days (deciviews) Average for

20% Worst Days Bext (Mm

- 1) Average for

20% Best Days Bext (Mm

- 1) Great Smoky

Mountains 30.3 13.6 216.3 40.2

Joyce Kilmer

Slickrock 30.3 13.6 216.3 40.2

Linville Gorge 28.8 11.1 183.6 31.2 Shining Rock 28.5 7.7 182.2 22.3 Swanquarter 24.7 12.0 123.9 33.79

III. Evaluation of Regional Haze Submittal

B . Reasonable Progress Goals 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, nat ural 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 techniq ues 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 R egional H aze Submittal

NC SIP Narrative, Page 8:

Procedures for calculating natural background visibility are delineated in “ Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Program” , EPA

- 454/B

- 03

- 005, September 2003. In the 2003 guidance, the USEPA also provided that states may use a “refined approach” to e stimate 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, fa ctors to calculate extinction from a measured particular species and particle size, the extinction coefficients for certain compounds, geographical variation (by altitude) of a fixed value, and the addition of visibility pollutants.

In 2005, the IMPROVE S teering Committee made recommendations for a refined equation that modifies the terms of the original equation 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 area is made by the state in which the Class I 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. The mass multiplier for organic carbon (particulate organic matter) is increased from 1.4 to 1.8. New ter ms 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 and large size distributions of ammonium sulfate and ammonium nitrate and for sea salt. The elemental carbon (light

- absorbing carbon), fine soil, and coarse mass terms do not change between the orig inal and new IMPROVE equation.

Natural background conditions using the new IMPROVE equation are calculated separately for each Class I area. The calculation starts with the annual average values for natural background for each component of PM2.5 mass fro m the EPA 2003 guidance (default values). The annual frequency distribution of values of each PM2.5 component for current conditions (2000

- 2004) is then defined. This species

- specific frequency distribution is applied to the default annual average values f or that PM2.5 component to calculate natural conditions on the 20% worst days. The current variability in each component is retained while also retaining the same annual average10

background condition for that component as defined in the 2003 guidance. The n ew calculation of natural background allows Rayleigh scattering to vary with elevation. Current sea salt values are used for natural background levels of sea salt.

The VISTAS states chose to use the new IMPROVE equation as the basis for the conceptual

des cription because it takes into account the most recent review of the science and because it is recommended by the IMPROVE Steering Committee.

The specific values used by NCDAQ are based on a report prepared for VISTAS by: Air Resource Specialists, Inc., 1901 Sharp Point Drive, Suite E, Fort Collins, Colorado 80525 and are documented in Appendix B.1.

Class 1 area Average for

20% Worst Days (deciviews) Average for

20% Best Days (deciviews) Average for

20% Worst Days Bext (Mm

- 1) Average for

20% Best Days Bext (Mm

- 1)

Great Smoky

Mountains 11.1 4.5 30.8 15.8

Joyce Kilmer

Slickrock 11.1 4.5 30.8 15.8

Linville Gorge 11.2 4.1 30.9 15.1

Shining Rock 11.5 2.5 34.9 12.1

Swanquarter 11.5 5.5 32.6 17.3

Figure 5. Natural Background Conditions for North Carolina Class I Areas

NC SIP, Appendix L.8:

On March 19, 2007, in a letter from Keith Overcash to James I. Palmer, Regional Administrator, US EPA Region 4, NCDENR requested approval for the use of the VISTAS methodology for the new IMPROVE equation.

EPA Findings : EPA proposes to find that North Carolina has adequately addressed this provision. I n a May 11, 2007 , letter from James I. Palmer, Regional Administrator, EPA Region 4, to B. Keith Overcash, NC DAQ , EPA Region 4 approved the use of the n ew IMPROVE equation ( NC Regional Haze SIP, Appendix L.8

, page 37).11

III. Evaluation of Regional Haze 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, the 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 ta te 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. The

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 o f other requirements of the CAA during the applicable planning period (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 same period.

State Regional Haze Submittal NC SIP Narrative, Pages 16

- 18:

The SIP presents glidepaths for the 20% most impaired days for Great Smoky Mountains National Park, Joyce Kilmer

- S lickrock Wilderness Area, Linville Gorge Wilderness Area, Shining Rock Wilderness Area, and Swanquarter Wildlife Refuge, assuming uniform rate of progress toward regional haze goals (figures 3.1

- 1 to 3.1

- 5 [figures 6

- 10 below] ) with values calculated every five years starting at the 2004 base year and continuing to natural background in 2064. Natural background visibility at all four sites is predicted to be between 11 and 12 dv. The Class I areas with the steepest slope from baseline to natural background conditions are Great Smoky Mountains and Joyce Kilmer

- Slickrock, while Swanquarter currently has the shortest path from the baseline level of visibility impairment to natural conditions.12

Figure 6

. Uniform Rate of Progress Glidepath for 20% worst days at Great Smoky

Mountains National Park.

Figure 7 . Uniform Rate of Progress Glidepath for 20% worst days at Joyce Kilmer

Slickrock Wilderness Area.13

Figure 8 . Uniform Rate of Progress Glidepath for 20% worst days at Linville Gorge

Wilderness Area.

Figure 9 . Uniform Rate of Progress Glidepath for 20% worst days at Shining Rock

Wilderness Area.14

Figure 10 . Uniform Rate of Progress Glidepath for 20% worst days at Swanquarter

Wildlife Refuge.

NC SIP Narrative, Pages 51

- 56:

Using 2000

- 2004 IMPROVE monitoring data, the deciview values for the 20% best days in each year are averaged together, producing a single average deciview value for the best days. Similarly, the deciview values for the 20% worst days in each year are averaged together, producing a single average deciview value for the worst days. The average values represent the current visibility conditions.

The predicted visibility improvement is calculated by comparin g the 2002 typical year modeling results for the 12

- km grid to the 2018 12

- km modeling results to develop a relative reduction factor. This factor is then applied to the current visibility condition values to estimate the future visibility. Detailed discus sions about how the relative reduction factors are calculated can be found in Appendix G.

Visibility improvements for the 20% worst days in all five Class I areas in North Carolina, are expected to be better than the uniform rate of progress by 2018 based solely on reductions from existing and planned emissions controls (figures 7.2.4

- 1 to 7.2.4

- 10). For example, at Great Smoky Mountains, a 4.5 dv improvement in visibility would meet uniform rate of progress in 2018; expected emissions reductions by 2018 a re projected to achieve a 6.6 dv improvement. The predicted percentage of the target reduction achieved for the North Carolina Class I areas, using the new IMPROVE equation, is between 140% and 180%. This means that the amount of visibility improvement e xpected from the modeled control programs is 40% to 80% more than what the uniform rate of progress would be for 2018 (figure 7.4.2

- 11).15

In addition to improving visibility on the 20% worst visibility days, states are also required to protect visibility o n the 20% best days at the Class I areas. Visibility on the 20% best days is projected to improve in 2018 at all VISTAS Class I areas as a result of the emissions reductions expected from federal and state control programs (figures 7.2.4

- 6 to 7.2.4

- 10). Th e percentage of the target achieved for the North Carolina Class I areas is about

- 10% (figure 7.2.4

- 12). Zero percent change would mean no change in visibility;

- 10% means that visibility is better than no change, or a 10% improvement (values lower than c urrent conditions).

Class I Area Baseline Visibility for

20% Worst Days Reasonable

Progress Goal

- 20% Worst Days (Improvement) Baseline

Visibility for

20% Best Days Reasonable

Progress Goal

- 20% Best Days (Improvement) Great Smoky

Mountains National

Park 30.3 23.7 (6.6) 13.6 12.2 (1.4)

Joyce Kilmer

Slickrock Wilderness

Area 30.3 23.7 (6.6) 13.6 12.2 (1.4)

Linville Gorge

Wilderness Area 28.8 22.0 (6.8) 11.1 9.6 (1.5) Shining Rock

Wilderness Area 28.5 22.1 (6.4) 7.7 6.9 (0.8) Swanquarter Wildlife Refuge 24.7 20.4 (4.3) 12.0 11.0 (1.0)

Figure 11

. North Carolina 2018 Reasonable Progress Goals (in deciviews)16

Figure 1 2 . Reasonable progress assessment compared to Uniform Rate of Progress for 20% worst days at Great Smoky Mountains National Park.

Figure 1 3 . Reasonable progress assessment compared to Uniform Rate of Progress for 20% worst days at Joyce Kilmer

- Slickrock Wilderness Area.17

Figure 1 4

. Reasonable progress assessment compared to Uniform Rate of Progress for 20% worst days at Linville Gorge Wilderness Area.

Figure 1 5 . Reasonable progress assessment compared to Uniform Rate of Progress for 20% worst days at Shining Rock Wilderness Area

.

Figure 1 6 . Reasonable progress assessment compared to Uniform Rate of Progress for 20% worst days at Swanquarter Wildlife Refuge.18

Figure 1 7 . Reasonable progress assessment for 20% best days at Great Smoky

Mountains National Park.

Figure 1 8

. Reasonable progress assessment for 20% best days at Joyce Kilmer

Slickrock Wilderness Area.19

Figure 1 9 . Reasonable progress assessment for 20% best days at Linville Gorge

Wilderness Area.

Figure 20. Reasonable progress assessment for 20% best days at Shining Rock

Wilderness Area.20

Figure 21. Reasonable progress assessment for 20% best days at Swanquarter Wildlife Refuge.

NC SIP, Appendix G

, P ages G

- 5 to G

- 13 :

Reasonable Progress Goals

For each Cla ss I area, there are three metrics of visibility that are part of the determination of reasonable progress:

1) Natural conditions, 2) Baseline conditions 3) Current conditions.

Each of the three metrics includes the concentration data of the visibility i mpairing pollutants as different terms in the light extinction algorithm, with respective extinction coefficients and relative humidity factors. Total light extinction is then converted to deciviews, and an average value for both the 20 percent best and 20 percent worst visibility days is calculated. After the natural, baseline, and current conditions are calculated, a uniform rate of progress, or glidepath, can be created for the 20% worst days for each Class I area. Next, an analysis of potential control measures is performed to determine what level of control would be achievable in the given timeframe and what the potential improvement to visibility would be as a result of these controls. After the potential control analysis, reasonable progress goals for the Class I areas are determined after consultation with surrounding states. The entire RPG determination for North Carolina Class I areas is described in Appendix H.

Model Application21

The purpose of a modeling assessment of uniform rate of progress is to determine if a proposed control strategy will result in uniform rate of progress being met when measured concentrations of particulate matter are used to estimate visibility impairment at some future date. The modeling is applied in a relative sense, s imilar to the fine particulate matter (PM25) attainment test. The following sections outline the process to determine 2018 projections from regional modeling, as suggested in the “Guidance on the Use of Models and Other Analyses for Demonstrating

Attainmen t of Air Quality Goals for Ozone, PM2.5, and Regional Haze”(from this point forward, referred to as “Attainment Guidance”).

3.1 Determination of 20% Best and worst Days The first step in developing model projections is to rank visibility (in deciviews) on each day with observed speciated PM2.5 data for each of the 5 years comprising the base period (2000

- 2004) for each Class I area. Day

- specific observations for mass associated with sulfate (SO4), nitrates (NO3), organic carbon (OC), elemental carbon (EC) , soil, and coarse matter (CM), should be used to calculate bext for each day using climatological relative humidity adjustment factor(s) (

f(rh) ). Total light extinction (bext) for all components should be converted to deciviews for each day to get a daily deciview value.

3.2 Determine Baseline Conditions The ranked visibility days from the first step are then used to calculate the average baseline deciviews for the 20% best and worst days. First, the mean deciview value for the identified 20%

worst

- and b est visibility days in each year is calculated (dv current). The 5 year mean deciview values reflecting mean visibility on the days with best visibility and then averaged to determine the baseline values for the best days, or the dv baseline values. Then t he 5 year mean deciview values reflecting worst visibility are averaged together. This represents the value subject to improvement to meet the glidepath for regional haze.

For each of the North Carolina Class I areas, the baseline visibility conditions we re estimated using sampling data collected at Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring sites at four of the five Class I areas in North Carolina. A five year average (2000 to 2004) was calculated for each of the 20 perce nt worst and 20 percent best visibility days in accordance with 40 CFR 51.308(d)(2) and the USEPA‟s Guidance for Tracking Progress Under the Regional Haze Rule. IMPROVE data records for Great Smoky Mountains and Linville Gorge for the period 2000 to 2004 m eet the USEPA‟s requirements for data completeness (75 percent for the year and 50 percent for each quarter). Shining Rock and Swanquarter had missing data in more than one year between 2000 and 2004. Data records for these sites were filled using data sub stitution procedures outlined in Appendix B. IMPROVE does not operate a monitor at Joyce Kilmer Wilderness Area and considers the IMPROVE monitor at Great Smoky Mountains to be representative of visibility in the Joyce Kilmer Wilderness Area. The light ext inction and deciview visibility values for the 20 percent worst and 20 percent best visibility days at the Class I areas are based on data and calculations included in Appendix B of

this SIP. Table 3.2

- 1 summarizes the mean yearly visibility conditions and the baseline visibility conditions for North Carolina Class I areas on both the 20% best and 20% worst days.22

3.3 Relative Response Factor Calculation The next step is to use base year and future year modeling results to estimate a relative response fa ctor (RRF) for each component of PM2.5 on the 20% best and worst monitoring days. Simply put, the RRF is the average future year concentration near the monitor divided by the average base year concentration or:

RRF = Average Modeled Future Year Concentrat ion/ Average Modeled Base Year Concentration

To accomplish this step, concentration for each component of PM2.5 and coarse matter (the difference between particles less than 10 micrometers in diameter (PM10) and PM2.5) are extracted from the base year and future year modeling output near IMPROVE monitoring sites for the monitored best and worst days. The component concentrations are then averaged to develop base and future year average component concentrations. The future year average component concentrati ons are then divided by their respective base year component concentrations to develop RRFs for each component of PM2.5 and coarse matter.

For a numerical example, consider Table 3.3

- 1, which has all the pertinent data for the GSMNP1

IMPROVE monitor. Look ing at the top table, the first column identifies the 20% best days identified in step 1 (Section 3.1). The next six columns have the 12km modeled base year (2002 concentration values near the monitor corresponding to the 20% best days. The next six column s have the 12km modeled future year (2018) component concentrations near the monitor for the same set of days. The final six columns contain the daily RRF values for each component species, which is simply the future concentration divided by the base year concentration. The bottom row of the table contains the average values for the base year components, the future year components, and the RRFs for each of the average component values. The bottom table contains the same data for the 20% worst days. Tables o f for each of the IMPORVE monitors of interest to North Carolina are provided, and abide by the same format.2324252627

3.4. Future Year Daily Concentration Calculation The fourth step in using model output to estimate the future visibility impairment is to multiply the relative response factors (determined in the previous step, Section 3.3) by the measured species concentration data during the base period (for the measured 20% best and worst days). This results in daily future year species concentrations data.

This is similar to the final step in the ozone attainment test, where base year concentrations, or the current year design value (DVC) is multiplied by the RRF to determine the future design value (i.e. DVF = RRF * DVC). For regional haze, this ca lculation is performed for each best and worst day for the five

- year base line period (calculated in step 2, Section 3.2) using an RRF for each PM component, for both the best days and the worst days. This produces future concentration estimates for SO4, N O3, OC, EC, Soil and CM, for each of the “worst” and “best” visibility days.

3.5. Future Year Daily bext Calculation Once future year concentrations are calculated (Section 3.4) the future daily extinction coefficients are then calculated for the 20% best and 20% worst visibility days in each of the five base years. This is achieved by applying the new IMPROVE equation (see Appendix B for a more information on the new IMPROVE equation):

bext ≈ 2.2 * fs(RH) * [Small Sulfate] + 4.8 * fL(RH) * [Large Sulfate ] + 2.4 * fs(RH) * [Small Nitrate] + 5.1 * fL(RH) * [Large Nitrate] + 2.8 * {Small Organic Mass] + 6.1 * [Large Organic Mass] + 10 * [Elemental Carbon] + 1 * [Fine Soil] + 1.7 * fss(RH) * [Sea Salt] + 0.6 * [Coarse Mass] + Rayleigh Scattering (site specifi c) + 0.33 * [NO2 (ppb)]

Model estimated daily concentrations are used with the corresponding base line daily relative humidity adjustment factor(s) ( f(rh) ) identified in step 1 (Section 3.1).

3.6. Future Mean Deciview Values Calculation The final step is to calculate daily deciview values from the total daily extinction calculated in the previous step, and then compute the future average mean deciviews for the worst and best day for each year. The 5 years are then averaged together to get the final future mean deciview value for the worst and best days.

The first step in this process is to convert the total daily bext for each day (calculated in the previous step, Section 3.5) to deciviews. This future year daily deciview value for each of the best and worst days is then averaged to determine the future deciview value for the “worst” and “best” visibility days for each year. This leads to 5 future estimated mean deciview values for the Modeling Results & Supplemental Analysis “worst” and 5 future estimated mean deciview values for the “best” visibility days. The five yearly values for the best and worst days are then averaged to produce the final future mean deciview value, or dv future. Table 3.6

- 1 displays the yearly2 8

daily deciview value for each year in the baseline period for both the 20% worst days (center column) and the 20% best days (right column). The last row in the table displays the final future mean deciview value, or dv future.

The resulting dv future values for the “worst” and “best” visibility days can be compared to the

d v baseline values calculated in step 2 (Section 3.2). If the resulting change in deciviews is a negative number (future

- base), this represents an improvement in visibility. Table 3.6

- 2
summarizes these calculation for the IMPROVE monitors associated with North Carolina Class I areas. From the table, it is apparent that all North Carolina Class I areas are showing visibility improvement on both the 20% best and 20% worst days

.

These changes in visibilit y can also be compared to the previously calculated (in Appendix B uniform rate of progress values for each Class I area (Figures 3.6

- 1 through 3.6

- 4). When plotted against the glidepath, one can see the change in deciview between the baseline and future shows an improvement that is well below the uniform rate of progress for all Class I monitoring sites in

North Carolina.

EPA Findings : EPA proposes to find that North Carolina has adequately addressed this provision. North Carolina’s r easonable p rogress goal s for Great Smoky Mountain National Park and Joyce Kilmer

- Slickrock Wilderness A rea d iffer from those submitted by Tennessee. North

Carolina confirmed in a February 16, 2010 letter from Keith Overcash

, NCDAQ

, to Stanley Meiburg , EPA Region 4 that the Tennessee values reflect the latest modeling completed after North Carolina completed its submittal and are the more appropriate targets . NCDAQ commits to revise their RPGs for these areas in the next five year submittal. EPA proposes to find this

approa ch acceptable.29

III. Evaluation of Regional Haze 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 doe s 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 tha t the emission inventory requirements under 40 CFR 51.308(d)(4)(v) are addressed in this section.

EPA Outline of Long Term Strategy C omponents :

The RHR at 51.308(d) requires states to demonstrate reasonable progress toward meeting the goal of a return to natural visibility conditions by 2064. The RHR then requires states to establish RPGs for visibility improvement at each affected Class I area c overing each approximately 10

- year period until 2064. Appendix H provides an overview of this first LTS. Appendix L includes

a discussion of the State’s strategy for assessing the BART requirements.

The N orth C arolina LTS contains the following component s:

I. Emission i nventory applying all controls required or expected under all federal and state regulations by 2009 and 2018.

II. Modeled expected visibility improvement and comparison of modeling results for 2018 to the uniform rate of progress, or “glidepath” for each Class I area. (See also

EPA TSD Section III.B.3)

III. Discussion of emissions sensitivity model runs to help determine which pollutants and source categories are contributing the most to visibility impairment at Class I areas (runs conducted by the Geo rgia Institute of Technology).

IV. Examination of sulfur dioxide (SO 2 ) area of influence (AOI) projections for each of North Carolina’s Class I areas, and also for any surrounding states’ Class I areas whose AOI includes any part of North Carolina, to determine which specific sources are most likely to be impairing visibility at specific Class I areas.

V. 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 Sect ion III.C.3)

VI. Using the results of the four factor analyses, identification of control determinations for specific sources.

VII. Identification of BART

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

VIII. BART exemption modeling for BART

- eligible sources. (See also EPA TSD Section III.D.2)30

IX. BART determinations for sources subject to BART. (See also EPA TSD Section III.D.3)

X. Modeling demonstration of visibility improvement after inclusion of BART and

reasonable control measure determinations.

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

State Regional Haze Submittal

Federal and State Control Requirements ( NC SIP Narrative, P ages 45

- 59)

CAIR

. CAIR will permanently cap emissions of SO2 and NOx from EGUs in the eastern United

States by 2015. When fully implemented, CAIR will reduce SO2 emissions from EGUs in these states by more than 70%, and NOx emissions by more than 60%, from 2003 levels.

NOx SIP Call . Phase I of the NO x SIP call applies to certain EGUs and large non

- EGUs,

incl uding large industrial boilers and turbines, and cement kilns. Those states affected by the NOx SIP call in the VISTAS region have developed rules for the control of NOx emissions that have been approved by the USEPA. The NOx SIP Call has resulted in a 6 8% reduction in summertime NOx emissions from large stationary combustion sources in North Carolina. For this analysis, we capped the emissions for NOx SIP call

- affected sources at 2007 levels, and carried forward the capped levels for the 2009 and 2018 f uture year inventories.

North Carolina Clean Smokestacks Act (CSA). Under the CSA, enacted in 2002, coal

- fired power plants in North Carolina must achieve a 77

- percent cut in NOx emissions by 2009 and a 73

- percent cut in SO2 emissions by 2013. This legi slation establishes annual caps on both SO2 and NOx emissions for the two primary utility companies in North Carolina, Duke Energy and Progress Energy. These reductions must be made in North Carolina, and allowances cannot be

sold.

Georgia Multi

-

pollutan t Bill . Georgia enacted regulations in summer 2007 to require coal fired power plants in Georgia to reduce SO2 by approximately 90%, NOx by approximately 50%, and mercury by an estimated 75

- 85% by 2015. Reductions will affect 21 units at seven facilities. The rule requires specific controls on specific units according to a specific schedule. This is not a cap and trade rule, thus there are no allowances to be banked, sold or traded.

Consent Agreements

. Under a settlement agreement, by 2008, Tampa Elect ric will install permanent 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, or sell to others, to emit additional NOx, SO2, and PM.

Virginia Electric and Power Company agreed to spend $1.2 billion by 2013 to eliminate 237,000 tons of SO2 and NOx emissions each year from eight c oal

- fired electric generating plants in Virginia and West Virginia.31

A 2002 agreement calls for Gulf Power to upgrade its operation to cut NOx emission rates by

61% at its Crist generating plant by 2007, with major reductions beginning in early 2005. The Crist plant is a significant source of NOx emissions in the Pensacola area.

In October 2007, American Electric Power agreed to spend $4.6 billion dollars to eliminate
72,000 to ns of NOx emissions each year by 2016 and 174,000 tons of SO2 emissions each year by 2018 from sixteen coal

-

fired power plants located in Indiana, Kentucky, Ohio, Virginia and West Virginia.

One

- hour ozone SIPs (Atlanta / Birmingham / Northern Kentucky ). New SIPs have been submitted to the USEPA to demonstrate attainment of the one

- hour ozone NAAQS. These SIPs require NOx reductions from specific coal fired power plants and address transportation plans in

these cities.

NOx RACT in 8

- hour Nonattainment Ar ea SIPs . The NCDAQ‟s SIP for the

Charlotte/Gastonia/Rock Hill nonattainment area includes Reasonable Achievable Control Technology (RACT) for NOx for two facilities located in the nonattainment area: Philip Morris

USA and Norandal USA. These controls were also modeled in 2018. Additional RACT controls may be realized as other companies subject to RACT complete the determination, but RACT

- level controls were assumed for just these two sources.

Heavy Duty Diesel (2007) Engine Standard (for on

- road trucks an d buses) . The USEPA set a PM emissions standard for new heavy

- duty engines of 0.01 grams per brake

- horsepower

- hour (g/bhp

hr), to take full effect for diesel engines in the 2007 model year. This rule also includes standards for NOx and non

- methane hydroca rbons (NMHC) of 0.20 g/bhp

- hr and 0.14 g/ bhp

- hr, respectively. These NOx and NMHC standards will be phased in together between 2007 and 2010, for diesel engines. Sulfur in diesel fuel must be lowered to enable modern pollution control technology to be e

ffective on these trucks and buses. The USEPA will 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 (ultra

- low sulfur diesel, or ULSD).

Tier 2 Tailpipe (On

- road vehicles) . The USEPA mobile source rules include the Tier 2 fleet averaging program, modeled after the California LEV II standards. Manufacturers can produce vehicles with emissions ranging from relatively dirty to zero e missions, but the mix of vehicles a manufacturer sells each year must have average NOx emissions below a specified value

. Tier 2 standards became effective in the 2005 model year. Large Spark Ignition and Recreational

Vehicle Rule. The USEPA has adopted new standards for emissions of NOx, hydrocarbons, and carbon monoxide from several groups of previously unregulated nonroad engines. Included in these are large industrial spark

- ignition engines and recreational vehicles. Nonroad spa rk

ignition 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, airp ort baggage transport vehicles, and a variety of farm and construction applications. Nonroad recreational vehicles include snowmobiles, off

- highway motorcycles, and all

- terrain

- vehicles. These rules were initially effective in 2004 and will be fully phase d

- in by 2012.32

Nonroad Diesel Rule . This rule sets standards that will reduce emissions by more than 90 percent from nonroad diesel equipment, and reduce sulfur levels by 99 percent from current levels in nonroad diesel fuel starting in 2007. This step w ill apply to most nonroad diesel fuel in 2010 and to fuel used in locomotives and marine vessels in 2012.

Industrial Boiler/Process Heater MACTs. The USEPA issued final rules to substantially reduce emissions of toxic air pollutants from industrial, com mercial and institutional boilers and process heaters. These rules reduce emissions of a number of toxic air pollutants, including hydrogen chloride, manganese, lead, arsenic and mercury by 2009. This rule also reduces emissions of SO2 and PM in conjuncti on with the toxic air pollutant reductions. The applied Maximum Achievable Control Technology (MACT) control efficiencies were 4 percent for SO 2 and 40 percent for PM10 and PM2.5. The USEPA‟s industrial boiler MACT rules were vacated on June 8, 2007. Th e VISTAS states decided to leave these controls in the modeling since it is believed that by 2018 the

USEPA will have re

-

promulgated a boiler MACT rule or states will have addressed the issue through state rule making.

Combustion Turbine and Reciprocating Internal Combustion Engines MACTs. The projection

inventories do not include the NOx co

- benefit effects of the MACT regulations for Gas Turbines or stationary Reciprocating Internal Combustion Engines, which the USEPA estimates to be small compared to th e overall inventory.

VOC 2

- , 4

- , 7

- , and 10

- year MACT Standards. Various point source MACTs and associated emission reductions were implemented. Reductions occurring before 2002 were assumed to be accounted for in the 2002 base year inventory.

Modeling System NC SIP Narrative, Pages 25

- 32:

Modeling for regional haze was performed by VISTAS for the ten southeastern states, including North Carolina. Chapter 5 outlines the methods and inputs used by VISTAS for the regional modeling. The modeling analysis i s a complex technical evaluation that begins by selection of the modeling system. VISTAS decided 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.

• Emissions Model: The Sparse Matrix Opera tor 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 biogenic emission sources for photochemical grid models.

• Air Quality Mo del: The USEPA‟s Models

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

- Atmosphere‟ photochemical grid model capable of addressing ozone, particulate matter (PM), visibility and acid deposition at regional scale. The33

photochemical mode l selected for this study was CMAQ version 4.5. It was modified with a module for Secondary Organics Aerosols (SOA) (Appendix F).

CMAQ modeling of regional haze in the VISTAS region for 2002 and 2018 was carried out on a grid of 12x12 km cells that cover s the VISTAS states (AL, GA, FL, MS, SC, NC, TN, KY, VA, WV) and states adjacent to them. This grid is nested within a larger national CMAQ modeling grid of 36x36 km grid cells that covers the continental United States, portions of Canada and Mexico,

and portions of the Atlantic and Pacific Oceans along the east and west coasts.

Transport of pollution from the national domain into the VISTAS modeling domain is reflected in hourly

- varying boundary conditions around the VISTAS domain, which are derived fro m the CMAQ simulations in the 36 km national domain. The national domain incorporates emissions from northern Mexico and southern Canada, and therefore explicitly calculates the effects of

these international emissions on concentrations at the boundaries of the VISTAS modeling

domain.

Effects of emissions from more distant sources that are outside of the 36 km national domain were estimated using outputs from a global air pollution model. VISTAS elected to use the outputs of the GEOS

- CHEM global air poll ution model, which also contains a detailed representation of ozone

- NO x

- VOC

- PM chemistry. The application and model performance evaluation of the GEOS

- CHEM model is described in detail in Appendix G of Appendix F on pages 1051

- 1061.

The coarse 36

- km horiz ontal grid domain was also used as the outer grid for MM5 meteorological modeling with the CMAQ domain nested within the MM5 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 d omain. Figure 5.4.1

- 2 shows the 12

- km grid, modeling domain for the VISTAS region.34

Figure 2 2 . The MM5 horizontal domain is the outer most, blue grid, with the CMAQ 36

- km

domain nested in the MM5 domain.

Figure 2 3

. A more detailed view of the 12

- km grid over the VISTAS region35

Modeling Episodes

The USEPA‟s 2007 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. Meteorol ogical inputs were developed for 2002 using the meteorological model. Emission inventories were also developed for 2002 and processed through the emissions model. These inputs were used in the air quality model to predict 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 configuration that gave the best overal l performance for the VISTAS region.

Model Performance Evaluation

NC S IP Narrative, Pages 33

- 44:

A model performance evaluation of the CMAQ and MM5 models was developed for the 2002 current year using graphical and statistical assessments. In keeping with the one

- atmosphere objective of the CMAQ modeling platform, the air quality model performance was evaluated based on measured ozone, fine particles, and acid deposition from various monitoring networks

and databases.

The model performance evaluation methodology was fully consistent with current EPA guidance and science community consensus on how fin e particulate/regional haze and ozone models should be evaluated with contemporary surface and aloft monitoring databases. Key to this evaluation is that the model was evaluated separately for each component of particulate matter (PM), including sulfate ( SO4), nitrate (NO3), elemental carbon (EC), organic carbon (OC), other fine particulate (PM2.5) and coarse particulate (PM10), as well as important gaseous species (e.g., ozone, nitrogen oxides (NOx), carbon monoxide (CO), ammonia (NH3) and nitric acid (NH 4)). The CMAQ model was evaluated using both daily averages and longer

- term (e.g., monthly, seasonal and annual) averages for SO2, SO4, NO3, EC, OC, PM2.5, and PM10.

Figure 2 4 . Model Performance Goals36

VISTAS‟s evaluation of the 2002 modeling year considered several statistical performance measures and displays (see Appendix F.2). VISTAS established model performance goals and criteria for components of fine particle mass (Table 6.1

- 1) based on previous model performance for ozone and fine particles. The USEPA‟s 2007 modeling guidance for fine particulate matter at the time noted that PM models might not be able to achieve the same level of performance as
ozone models. VISTAS‟s evaluation considered se veral statistical performance measures and displays. Fractional bias and mean fractional error were selected as the most appropriate metrics to summarize model performance; other metrics were also calculated and are included for IMPROVE monitors in the fu ll model performance evaluation. A full list of air quality model performance statistics is found in Appendix F.2.

For example, in the analyses, mean fractional bias (error) was used in lieu of mean bias (error), to prevent low observations and model pr edictions from skewing the metrics. 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. The soccer plots of monthly concentrations (Figures. 6.2

- 1 and 6.2

- 2) show that values for nitrate generally fall outside of criteria 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 soc cer plots for each season. The seasonal plots emphasize poorer nitrate performance in the summer, when observed nitrate is quite low and predicted nitrate is even lower.

Figure 6.2

- 1: Soccer plot depicting both the mean fractional error and fractional bi as for component concentration for all VISTAS sites.

Figure 2 5 . Soccer Plot for all VISTAS sites

Figure 6.2

- 2: A zoomed view of the soccer plot depicting both the mean fractional error and fractional bias for component concentration for all VISTAS site s.37

Figure 2 6 . Soccer Plot for all VISTAS sites

– zoomed view

Figure 6.2

- 3: Seasonal soccer plots for all VISTAS IMPROVE monitors.

Figure 2 7 . Soccer Plot for all VISTAS sites

– Seasonal

The model performance for North Carolina‟s Class I areas shows varied, though acceptable agreement when using a stacked bar chart of observed fine particulate matter composition and modeled fine particulate matter composition on the 20% Worst and Best days . This allows a side38

by side comparison of the each day‟s observed and modeled compositional and total light extinction. See pages 39

- 44.

Model performance for 2002 was deemed adequate and acceptable for use in modeling future predictions for ozone, PM2. 5 and regional haze. The one

- atmosphere modeling performed by the VISTAS contractors is representative of conditions in the southeastern states and is applicable for use in analyzing future strategies for regional haze for the Class I areas. The 2002 curr ent and 2018 future year emissions were processed through the SMOKE emissions model. The air quality modeling results are used in a relative manner to determine a relative reduction in future visibility impairment.

More detailed discussions of the modelin g protocol, quality assurance report, procedures, models and data used in the regional haze analysis can be found in Appendices C, E, F, and G.

There are significant control programs being implemented between the baseline period and 2018.

Emission reduc tions from these control programs are projected to achieve substantial visibility improvement by 2018 in the North Carolina Class I areas. These programs are described in more

detail below.

Sources and Pollutants relied on for LTS ( NC S IP Narrative, P ages 61

- 77)

An important step toward identifying further reasonable progress measures is to identify the key pollutants contributing to visibility impairment at each Class I area. To understand the relative benefit of further reducing emissions from dif ferent 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 poll utant 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 Bou ndary

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 point (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 s ources 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 Carbo n from all fires in each VISTAS state and other RPOs39

Results are shown in Figures 7.4

- 1 through 7.4

- 4 below for the average of the 20% worst visibility days for each of four North Carolina Class I areas. Responses for 20% worst days were calculated by ave raging the responses of the 20% worst days that were modeled in the two episodes. For the North Carolina sites, responses on five to six of the 20% worst visibility days were included in these graphics.

Figure 2 8

. - Figure 7.4

- 1. CMAQ projections of v isibility responses on 20% worst days at Great Smoky Mountains to 30 % reductions from a 2009 inventory for visibility

- reducing pollutants in different source categories and geographic areas.40

Figure 2 9

. - Figure 7.4

- 2. CMAQ projections of visibility responses on 20% worst days at Shining Rock to 30% reductions from a 2009 inventory for visibility

- reducing pollutants in different source categories and geographic areas.41

Figure 30

. Figure 7.4

- 3. CMAQ projections of visibility responses on 20% worst days at Linville Gorge to 30% reductions from a 2009 inventory for visibility

- reducing pollutants in different source categories and geographic areas.42

Figure 31

. - Figure 7.4

- 4. CMAQ projections of visibility respon ses on 20% worst days at Swanquarter to 30% reductions from a 2009 inventory for visibility

- reducing pollutants in different source categories and geographic areas.

As Figures 7.4

- 1 through 7.4

- 4 illustrate, the greatest visibility benefits on the 20% wor st days for the North Carolina Class I areas are projected to result from further reducing SO2 from EGUs. At the mountain Class I areas, benefits are projected from SO2 reductions from EGUs in several VISTAS states including Alabama, Georgia, Kentucky, Nor th Carolina, South Carolina, Tennessee, Virginia, and West Virginia. Contributions from other RPOs and from the boundary conditions are comparatively small and the greatest benefits would likely be from further EGU

reductions within the VISTAS states. In c ontrast, at Swanquarter, reductions from EGUs in North Carolina and South Carolina would have the greatest benefits and the contributions from other VISTAS states are comparatively small. MANE

- VU states also contribute, as do SO2 and SO4 coming into the mo deling domain from outside the boundary (e.g. Atlantic Ocean).

Additional, smaller benefits are projected from additional SO2 emission reductions from nonutility, industrial point sources. The pattern of relative SO2 contributions from non

- EGUs among the various VISTAS states is similar to the pattern of relative SO2 contributions from

EGUs.

Because ammonium nitrate is a small contributor to PM2.5 mass and visibility impairment on the 20% worst days at the mountain Class I areas, the benefits of reducing NOx and NH3 emissions at these sites are small. Some of the 20% worst days at Swanquarter, and other coastal sites in the VISTAS states, occur in the winter when ammonium nitrate has a somewhat larger contribution to visibility impairment. As shown in Figu re 7.4

- 4, reducing ammonia emissions would be more beneficial for reducing ammonium nitrate contributions to visibility impairment in wintertime than further reducing nitrogen oxide emissions from either ground or point sources.

For Swanquarter, the numer ous hog farms in eastern North Carolina are the likely primary emission sources for ammonia. VOC emissions do contribute to visibility impairment, but as shown in the charts above, this contribution is from biogenic sources such as vegetative

emissions. Co ntrolling anthropogenic sources of VOC emissions has little if any visibility benefit at the Class I areas. Reducing primary carbon from point sources, ground level sources or fires are projected to have small to no visibility benefit. This is consistent w ith the monitoring data that shows that most of measured organic carbon is secondary in origin and primary carbon is only a small fraction of the total measured carbon (Appendix B). The sensitivities were not useful in analyzing reductions carbon from fire s because there was little fire activity at these sites on the days modeled. However, looking at the 2000

– 2004 reconstructed extinction, using the new IMPROVE equation, for the 20% worst days it is clear that the number of days where fires played

a role in visibility impairment was approximately 2% to 3% of the days in the entire baseline period (see Appendix B). Therefore, although the emission reduction sensitivities did not include many days influenced by fires, this should not impact the ultimate re sults of the sensitivities.

Note that these results from the emission sensitivity runs are consistent with the conclusions drawn from the 2000

- 2004 baseline monitoring data (see Section 2.4 of the SIP NArrative). The results indicate that sulfate is the dominant contributor to visibility impairment on the 20% worst43

days at all sites, and that ammonium nitrate may be important for sites where the 20% worst days occur in the winter. The NCDAQ concluded that reducing SO2 emissions from EGU and non

EGU poin t sources in the VISTAS states would have the greatest visibility benefits for the North Carolina Class I areas. Contributions from the Midwest RPO and MANE

- VU are greater at the Class I areas bordering these RPOs. Contributions from outside the VISTAS 12

- km modeling domain are more important for the coastal Class I areas. These results are consistent with the CMAQ model results indicating that contributions from international emissions to visibility impairment at VISTAS Class I areas are greater closer t o the boundaries of the modeling domain (see Appendix H for further discussions).

EPA Note : 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, 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), EPA proposes to find that the State of

North 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 support 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 to

determine visib ility improvement for the uniform rate of progress because the modeling system 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 North Carolina LTS and regional haze SIP.

CAIR is also an element of North Carolina ’s LTS. CAIR rule revisions were approved into the

North Carolina SIP in 2007 and 2009. See 72 FR 56914 (October 5, 2007); 74 FR 62496 (November 30, 2009). North Carolina opted to rely on CAIR emission reduction requirements to satisfy the BART requirements for SO 2 and NO X from EGUs. See 40 CFR 51.308(e)(4). Therefore, North Carolina only requ ired 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, North Carolina concluded that no additional controls beyond CAIR are

reasonab le for reasonable progress for SO 2 for its EGUs for this first implementation period.

Prior to the remand of CAIR, EPA believed the State’s reliance on CAIR for specific BART and reasonable progress provisions affecting its EGUs was adequate. The regio nal haze provisions specify that a state may not adopt a RPG that represents less visibility improvement than is expected to result from other CAA requirements during the planning period (40 CFR 51.308(d)(1)(vi)). As such, North Carolina took into account emissions reductions anticipated from the CAIR in determining its 2018 RPGs.

The RHR allows states to implement an alternative program in lieu of BART so long as the alternative program can be demonstrated 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 regulations provide that states participating in the CA IR cap

- and trade program under 4044

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 electrical generating (EGUs) to install, operate, a nd 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 , 550F.3d 1175 (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 reasonable progress towards the nation al 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 f or 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 North Carolina regional haze

SIP because of deficiencies in the State’s regional haze SIP submittal arising from the remand by

the D.C. Circuit to EPA of CAIR. See 76 FR 82219. Consequently, EPA is not taking action in this proposed rulemaking to address the State’s reliance on CAIR to meet certain regional haze requirements.

In addition , on July 30, 2007, the D.C. Circuit mandated the vacatur and remand of the In dustrial Boiler MACT Rule. Notwithstanding the vacatur of this rule, the VISTAS states, including North 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

- promulgated 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 that 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 North Carolina did not redo its modeling analysis when the rule was re

- issued. Even though North Carolina’s modeling is based on the vacated Industrial Boiler MACT limits, the State’s modeling conclusions are unlikely to be

1 See NRDC v. EPA , 489 F.3d 1250 (D.C. Cir. 2007).45

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., 0.1 to 0.4 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 North 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 North Carolina to do so in the State’s five

- year progress report.

References used in the EPA review:

1. G uidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze

, April 2007, EPA

- 454/B

- 07

- 002.
http: //www.epa.gov/scram001/guidance/guide/final

- 03

- pm

- rh

- guidance.pdf

.

2. “(Draft) Guidance for Demonstrating Attainment of Air Quality Goals for PM 2.5 and Regional Haze”, EPA, (2001), 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 to Peter Tsirigotis, November 18, 2002.

4. July 15, 2008

, e

- mail from Laura Boothe , NCDAQ, to Brenda Johnson , EPA . Subject: Fwd: Re: question about MACT reductions.

5. CAA §§112(j)(2), (3), (5), and (6).

6. CAA §505 specifies procedures for notification to the Administrator and affected s tates.46

III. Evaluation of Regional Haze Submittal

C . Long

- Term Strategy

C.2 . Identification of Sources and Factors to be Considered: (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 minimum, 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 construction activities; (C) e missions limitations and schedules for compliance to achieve the reasonable progress goal; (D) source retirem ent and replacement schedules; (E) smoke management techniques for agricultural and forestry management purposes including plans as currently exist within the State for these purposes; measures to mitigate the impacts of construction activities; (F) enforc eability of emission limitations and control measures; and the (G) anticipated net effect on visibility due to proje cted

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

State Regional Haze Submittal NC SIP Narrative, Pages 85

- 88:

The following summarizes the process for determining reasonable progress for North Carolina sources. A detailed discussion of the reasonable progress assessments for all units with a contribution of greater than one percent to visibility impairment at any Class I area in North Carolina or in neighboring states is in Appendix H.

Step 1: Determine pollutants of concern. VISTAS evaluated the species contribution on the 20% worst visibility days in the baseline period and concluded that sulfate accounted for g reater than 70% of the visibility impairing pollution. The VISTAS States concluded that controlling SO2 emissions was the appropriate step in addressing the reasonable progress assessment for 2018.

Step 2: Determine which source sectors should be evaluat ed for reasonable progress. Since the pollutant of primary concern was determined to be SO2, the emissions inventory was assessed to determine the source categories that contribute the most SO2 emissions. Point source emissions in 2018 are projected to rep resent greater than 95% of the total SO2 emissions inventory, the VISTAS States concluded that the focus should be on electric generating unit (EGU) and non

- EGU point sources of SO2 emissions.

Step 3: Determine if the Clean Air Interstate Rule is sufficie nt for reasonable progress for subject EGUs. The NCDAQ evaluated the amount of SO2 reduction from the EGU sector resulting from the implementation of the North Carolina Clean Smokestacks Act (CSA) and CAIR. The EGUs in North Carolina are expected to reduc e their SO2 emissions by greater than 80% between 2002 and 2018. Much of that reduction is the result of CSA requirements which are directly enforceable and which must be satisfied by actual emission reductions as opposed to buying

banked Title IV allowanc es to meet the system

- wide emissions caps. The NCDAQ intends to re

evaluate the IPM predictions of SO2 reductions for CAIR at the time of its next periodic report in47

2012 to ensure that the reductions are in fact taking place where they were predicted. Ba sed on the controls required by CSA, and predicted by IPM under CAIR, the NCDAQ has concluded that at this time these existing regulatory programs constitute reasonable control measures for North Carolina EGUs during this first assessment period (between b aseline and 2018).

Step 4: Determine which emission units would be evaluated based on impact. The NCDAQ calculated the fractional contribution from all emission units within the SO2 Area of Influence for a given Class I area and identified those emission units with a contribution of one percent or more to the visibility impairment at that Class I area. A full description of this process and a list of sources considered in the reasonable progress evaluation can be found in Appendix H.

The following table shows, in tabular form, the relative contributions of point source SO2 emissions from nearby states to North Carolina‟s Class I area. These percentages were estimated by multiplying the maximum residence time to the emissions over distance.

Figure 3 2

. 2018 Point Source SO2 Contribution to NC Class I Areas by State

Spreadsheets were developed for each Class I area source with Q/d > 5 or Q/d 2 > 0.03, indicating the plant name, industry description, emissions projections for 2018, current control efficiency (CE%), distance from Class I area, Q/d, Q/d 2 , RT average, RT maximum, Q/d*RT, the fraction a single source contributes to the total Q/d*RT for a Class I area. CE% is important because it gives a sense of which facilities are already controlled b y what percent and which may be controlled further. Tables 5

- 2 through 5

- 6, show the analysis for the North Carolina Class I areas for sources that met the above criteria. The full spreadsheets containing all VISTAS Class I area results can be found in Att achment H

- 1b

.48

Figure 3 3

. Linville Gorge

- Point Source SO2 Contribution to NC Class I Areas

Figure 3 4 . Shining Rock

- Point Source SO2 Contribution to NC Class I Areas49

Figure 3 5 . Swanquarter

- Point Source SO2 Contribution to NC Class I Areas

Figure 3 6 . Great Smokies

- Point Source SO2 Contribution to NC Class I Areas50

Figure 3 7 . Joyce Kilmer

- Slickrock

- Point Source SO2 Contribution to NC Class I Areas

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. If any control measure for an emission unit was found reasonable after assessing the four factors, modeling would be performed to determine if the controls would result in a visibility improvement at any Class I area. For the limited purpose of evaluating the cost for th e reasonable progress assessment in this first regional haze SIP, the NCDAQ believes it is not equitable to require non

- EGUs to bear a greater economic burden than EGUs for a given control strategy. The NCDAQ used the capital and operating costs provide by Duke Energy and Progress Energy for the CSA compliance plans to establish a cost/ton of SO2 removed threshold. During the current reasonable progress assessment, no units in North Carolina were identified for additional control since no measures were foun d to be below the cost threshold.

NC SIP Narrative, Pages 91

- 93:

Section 308(d)( 3)(v) of the regional haze rule lists several factors that must be addressed in each SIP. These factors include the role of fire at Class I areas and status of state planning for smoke management, the role of dust and fine soil at Class I areas and status of state plans to mitigate51

emissions from construction activities and the role of NH3 and potential benefits if emissions from agricultural sources were mitigated.

As discussed in Section 2.4 and demonstrated in Figures 2.4

- 1 and 2.4

- 2, elemental carbon ( sources include agricultural burning, prescribed wildland fires, and wildfires) is a relatively minor contributor to visibility impairment at the Class I areas in North Carolina. However, the NCDAQ is currently working with the North Carolina Division of F orest Resources to develop a smoke management program that utilizes basic smoke management practices and addresses the issues laid out in the USEPA‟s 1998 Interim Air Quality Policy on Wildland and Prescribed Fires. Additionally, the NCDAQ is working with the North Carolina Department of Agriculture to develop a Memorandum of Understanding regarding agricultural burning. The NCDAQ anticipates that the resulting smoke management program and Memorandum of Understanding should be sufficient to satisfy the dire ctive in 40 CFR 51.308(d)(3)(v)(E).

Also as discussed in Section 2.4 and demonstrated in Figures 2.4

- 1 and 2.4

- 2, fine soils are a relatively minor contributor to visibility impairment at the Class I areas in North Carolina. Nevertheless, in regard to con struction activities, the NCDOT Division of Highways has issued regulations addressing control of erosion, siltation, and pollution from construction activities.

Section 107

- 13(E) of the Division of Highways General Contract Specifications, Division 1

Gene ral Requirements, reads as follows:

(E) Dust Control The Contractor shall control dust throughout the life of the project within the project area and at all other areas affected by the construction of the project, including, but not specifically limited t o, unpaved secondary roads, haul roads, access roads, disposal sites, borrow and material sources, and production sites. Dust control shall not be considered effective where the amount of dust creates a potential or actual unsafe condition, public

nuisance , or condition endangering the value, utility, or appearance of any property. The Contractor will not be directed compensated for any dust control measures necessary, as this work will be considered incidental to the work covered by the various contract it ems.

In addition, the NCDAQ has recently promulgated a new rule, effective on September 1, 2007, intended to control particulates from fugitive dust emission sources generated within plant boundaries from activities such as “unloading and loading areas, p rocess areas, stockpiles, stock pile working, plant parking lots, and plant roads (including access roads and haul roads).”

Note that benefits from neither the new rule nor the NCDOT dust ordinance have been included in the VISTAS modeling runs. Copies of the dust ordinance and the NCDAQ rule are attached to Appendix H.

In regard to agricultural ammonia, the NCDAQ, as a continuation of the CSA, initiated the Climate Action Planning Advisory Group (CAPAG) to develop widespread and specific options for the reduction of greenhouse gas emissions in North Carolina. The CAPAG is comprised of leaders from agricultural, industrial, local and state governmental and environmental sectors in North Carolina. This collaborative effort developed mitigation options throu gh a consensus process to simultaneously address the goal of reducing green house gas emissions and improve52

the quality of life in North Carolina. Agriculture and waste in North Carolina is one of the major areas being developed to reduce greenhouse gases. Since North Carolina is second in the nation in production of pork, one of the options being developed promotes increased use of the energy content of hog and cattle waste through the expansion of biodigesters.

To accomplish the expanded utilization of m ethane (a greenhouse gas) from hog/cattle waste for energy, the report supports expanded research, regulatory actions, and grant guarantees as key implementation tools. Inherent to the success are improved waste management practices. With increased support and improved management a co

- benefit will be the reduction of ammonia emissions from animal waste. As less ammonia will be applied to soils, lower direct emissions of ammonia will occur and lower emissions of nitrous oxide (N2O), a potent greenhouse gas, from soils will occur. The exact benefits from the reduction in ammonia emissions have not been quantified.

In addition, the North Carolina Legislature approved a bill on July 26, 2007 that permanently bans new hog lagoons and orders state regulators to s et environmental standards for new systems. The new legislation creates a phase

- out of waste lagoons used by hog farmers, replacing them with more environmentally friendly systems paid for in part by taxpayer

- funded grants. The

bill is included as an atta chment to Appendix H.

VISTAS is working on a modeling run that will include the cumulative benefits from the emission controls discussed in Section 7.2.1, any controls resulting from BART determinations within the other VISTAS states and any controls resu lting from the other states within VISTAS to address reasonable control measures. These modeling results were not completed in time to be included with this Regional Haze SIP. Additionally, not all states within VISTAS have completed their

reasonable contr ol measures analysis and the modeling does not include controls resulting from BART determinations or reasonable control measures from states located outside the VISTAS region. Since it may take a significant amount of time to have a modeling run completed that incorporates all of these measures, the NCDAQ has decided that it will incorporate these types of results in the first periodic review in 2012.

EPA Findings : EPA proposes to find that North Carolina has adequately addressed this provision. Prior to the remand of CAIR, EPA believed the State’s reliance on CAIR for specific BART and reasonable progress provisions affecting its EGUs was adequate. The regional haze provisions specify that a state may not adopt a RPG that represents less visibil ity improvement than is expected to result from other CAA requirements during the planning period (40 CFR 51.308(d)(1)(vi)). As such, North Carolina took into account emissions reductions anticipated from the CAIR in determining its 2018 RPGs.

In a separate action proposing limited disapproval of the regional haze SIPs of a number of states, EPA noted that these states relied on the trading programs of CAIR to satisfy the BART requirement and the requirement for a LTS sufficient to achieve the s tate

- adopted RPGs. See 76 FR 82219 (December 30, 2011). In that action, EPA proposed a limited disapproval of North Carolina’s regional haze SIP submittal insofar as the SIP relied on CAIR. For that reason, EPA is not taking action on that aspect of Nort h Carolina’s regional haze SIP in this action.53

III. Evaluation of Regional Haze 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

NC SIP Narrati ve, Pages 84

- 85:

The regional haze rule requires that states consider the following factors and demonstrate how these factors were taken into consideration in selecting the reasonable progress goal: • the costs of compliance • the time necessary for comp liance • the energy and non

- air quality environmental impacts of compliance, and • the remaining useful life of any potentially affected sources.

Cost of Compliance: As defined in Section 7.6.5, coal

- fired electric utilities and coal

- fired industrial boilers were the largest source categories contributing to SO2 in 2018 in the Areas of Influence defined for the North Carolina Class I areas. Industrial boilers using oil and commercial and institutional

boilers using coal or oil had small contributions t o SO2 in 2018. Sulfur dioxide emissions from utility, industrial, commercial, or institutional boilers can be controlled either by switching the fuel source to a lower sulfur fuel content or by installing post

combustion controls. Costs vary by fuel source ; boiler type and boiler size and require source specific analyses for accuracy. Bituminous coal is commonly burned in boilers in the eastern US. Switching to another bituminous coal with lower sulfur content or blending bituminous coals can

reduce SO2 em issions with least impact to boiler performance. While sub

- bituminous coal has

lower sulfur content than bituminous coal, it also has lower heat content and so more coal has to

be burned to generate the same energy output. For boilers that are designed for bituminous coal, only a small fraction of the fuel can be switched to low sulfur sub

- bituminous coal without adversely affecting boiler operations. Boiler modifications to accommodate low sulfur sub

bituminous coal may not be cost

- effective. Contract init iation and termination costs, differential fuel prices and heat contents, transportation costs, and modification to boiler operations, fuel handling and waste handling systems will have to be considered specific to each source.

Flue

- gas desulfurization is the common post

- combustion control for coal

- fired boilers. F lue gas is passed through an absorbent for sulfur dioxide (generally limestone or lime) in a wet scrubber, dry scrubber, or spray dryer. A calcium sulfate by

- product is produced that may be furt her processed to produce gypsum as a commercial byproduct. Costs of flue

- gas desulphurization include initial capital costs and ongoing operational and maintenance costs for the absorber54

tower, sorbent handling, and waste product handling facilities. Costs per ton of SO2 removed vary with boiler size, type, and available space for retrofit control devices. For oil

- fired boilers, lower sulfur oil may be an option. Costs need to consider differential fuel prices and heat content, boiler modifications, fuel ha ndling costs, and maintenance costs. Conceptually, post

- combustion controls can be used for oil boilers, but there is little precedence for such installations.

Time Necessary for Compliance: For fuel switching, the time necessary to terminate existing fuel contracts and initiate new contracts needs to be considered. Generally two to three years may be required. Installation of

post

- combustion controls will require 3 or more years depending on market availability of labor and materials and utility system

- wide priorities. Time necessary for compliance will need to be refined for specific sources.

Energy and Non

-

Air Environmental Impacts: Switching to lower sulfur fuel or installing post

- combustion controls may reduce boiler heat rate and energy output. Sc rubbers and spray dryers will require additional safeguards for fuel handling and waste handling systems to avoid additional non

- air environmental impacts such as increased effluents in waste water discharges and storm water runoff. These factors will need to be considered specific to individual sources. Carbon dioxide is emitted as a by

- product of flue gas desulfurization, therefore impacts of increased carbon emissions will need to be considered,

p articularly if carbon emissions are limited in the future under climate change mitigation strategies.

Remaining Useful Life: The useful remaining life is specific to the unit for which controls are considered.

NC SIP Narrative, Pages 88

- 91:

Results of four

-

factor analysis: The following is a brief summary of the four

- factor analysis. More detail is included in Appendix H. The NCDAQ used the cost of compliance as a screening tool to determine the universe of sources to perform the full four

- factor evaluation. Therefore, the summary is focused on the cost of con trol. The dollar per ton of SO2 removed that the NCDAQ used to determine if the cost was reasonable was based on the facility

- by

- facility and system wide EGU costs for implementing CSA and are included as Attachment 2 to Appendix H. The facility

- by

- facilit y costs ranged from 912 to 1,922 dollars per ton of SO2 removed, and the average costs per system ranged from 1,231 to 1,375 dollars per ton of SO2 removed. The CSA controls will reduce SO2emissions at North Carolina EGUs by more than 80 percent between 20 02 and 2018.

For non

- EGUs, the NCDAQ found that emissions from the following facilities contributed one percent or more to visibility impairment in a Class I area, and therefore focused the reasonable progress assessments on specific units at these facili ties:

Blue Ridge Paper Products PCS Phosphate Weyerhaeuser Plymouth55

Weyerhaeuser New Bern Congentrix Kenansville

Additionally, two units at Ecusta Business Development Center contributed more than one percent to visibility impairment at Shining Rock Wilderness Area. However, this facility has since closed and therefore was not evaluated for reasonable progress.

The NCDAQ also looked at what sources in North Carolina may be im pacting Class I areas located outside of the State, as well as what sources located outside of North Carolina may be impacting the North Carolina Class I areas. Letters were sent to the states (see Appendix J) identifying which sources in North Carolina ma y impact their Class I areas and what the NCDAQ had deemed as reasonable control measures. Additionally, the letters requested information on what each state had deemed as reasonable control measures for their sources impacting North Carolina‟s Class I are as.

The only North Carolina source that was identified, outside of facilities listed above, was the Duke Power Dan River facility, which may impact James River Face Wilderness in Virginia. Since this facility is subject to CAIR, the NCDAQ had deemed no a dditional controls would be required.

Blue Ridge Paper Products Some of the units at Blue Ridge Paper Products were subject to BART. These units were analyzed for BART and are addressed in Appendix L. Since the BART a determination takes into consideration many of the same factors as for reasonable progress, the BART subject units were

not re

- evaluated in the reasonable progress review. The NCDAQ evaluated swit ching to lower sulfur content coals. Currently, the company is using 0.75% sulfur coal in one boiler regulated by NSPS. The NCDAQ did cost calculations for the following scenario: if 0.75 percent sulfur content coal was required across the mill for the bo ilers that currently use about one percent sulfur coal. This measure could result in 1400 tons SO2 per year reduced. Based on information from the company, the lower sulfur coal is $75

- 90 per ton and the other coal (one percent sulfur) on site is $65 per ton. The cost is $10

- 25 per ton difference. The company burned 277,214 tons of one percent sulfur coal in 2005; switching to lower sulfur coal (0.75%) would cost ~ $2,772,140

- $6,930,350 extra per year. If 1400 tons of SO2 were reduced, costs would be in the range of $1980

- $4950 per ton, with an average cost of $3,465per ton.

Add

- on control technology for these units cost in the range of $12,055 to $100,961 per ton of SO2 removed. The NCDAQ concludes that there are no cost

- effective controls available fo r these units at this time within the cost threshold established for this reasonable progress assessment. Although the NCDAQ has concluded that for this reasonable progress period there are no cost

effective controls, the agency acknowledges that the emiss ions from Blue Ridge Paper Products do have impacts on the Class I areas located in the mountains. The NCDAQ has notified the company that although additional controls are not being required this planning period, future

planning periods may require control s to be installed. The NCDAQ is committed to work with this company over the next review period and to encourage the company to modernize some of its processes with more efficient, less polluting equipment.

PCS Phosphate56

Some of the units at PCS Phosphate were subject to BART. These units were analyzed for BART and are addressed in Appendix L. Since the BART determination takes into consideration many of the same factors as for reasonable progress, the BART subject units were not re

evaluated in the reason able progress review. No control options were listed in the VISTAS‟s control cost spreadsheet for any of the four units at this facility. The two PCS Phosphate units not subject to BART currently utilize dual absorption systems with a vanadium catalyst. O ther technologies reviewed included sodium bisulfite scrubbing, molecular sieve, ammonia scrubbing, and dual absorption process with cesium

- promoted catalyst. The first 3 options were rejected because they have not been commercially demonstrated to reliabl y meet current NSPS and state permit limits. The fourth was found to cost $3,433/ton to $3,457/ton SO2 reduced based on a reduction of sulfur emissions from 3.8 to 3.5 lb SO2/ton sulfuric acid. Therefore, the NCDAQ

concludes that there are no cost

- effectiv e controls available for these units at this time within the cost threshold established for this reasonable progress assessment. The NCDAQ has notified the company that although additional controls are not being required this planning period, future planni ng periods may require controls to be installed. In addition, PCS Phosphate has submitted a Prevention of Significant Deterioration application to the NCDAQ. The company plans to shut down the two sulfuric acid plants subject to BART and build one new pla nt.

Weyerhaeuser Plymouth Weyerhauser Plymouth contains two boilers burning a combination of fuels. There were no controls suggested for the Boiler 1 or 2 in the VISTAS Control Cost Spreadsheet. For the Riley Boiler, the control suggested by VISTAS Contr ol Cost Spreadsheet is an FGD at a cost of $20,460 per ton of SO2 removed. Therefore, the NCDAQ concludes that there are no cost effective controls available for these units at this time within the cost threshold established for this reasonable progress as sessment.

Weyerhaeuser New Bern Weyerhaeuser New Bern contains one residual oil

- fired boiler. The control suggested by VISTAS Control Cost Spreadsheet is an FGD at a cost of $17,317 per ton of SO2 removed. Therefore, the NCDAQ concludes that there are no cost

- effective controls available for these units at this time within the cost threshold established for this reasonable progress assessment.

Cogentrix Kenansville Congentrix Kenansville is currently burning unadulterated wood (pure wood with up to 5%

im purities). The company retains coal as a permitted fuel on the permit, with no immediate plans to use it. They are currently burning wood and their new business plan is to continue just burning wood as part of the "green power" movement here in North Carol ina. The 2005 actual SO2 emissions for this unit were 23.25 tons, whereas the projected 2018 SO2 emissions were 1,833.8 tons based on using coal. The NCDAQ is sending the company a letter indicating that they are currently on the list of sources contributi ng greater than one percent contribution to visibility impairment at Swanquarter Wildlife Refuge based on the estimated emissions from burning coal. The letter will suggest that they change their permit to remove coal as a possible fuel source for

this uni t.

Summary:57

During the current reasonable progress assessment no units in North Carolina were identified for additional control since no measures were found to be below the cost threshold discussed in Step 5. In addition to costs, the statutory factors in clude time necessary for compliance, remaining useful life of the facility, and energy and non

- air environmental impacts of the control installation. However, since no cost effective control measures were identified for the specific

sources with contributi ons to North Carolina or neighboring States‟ Class I areas, the NCDAQ did not invest in an exhaustive review of the remaining three factors beyond that described in section 6.4 for control options for major SO2 source sectors.

Neither the time necessary for compliance nor the energy and non

- air quality environmental impacts of compliance appear to be out of the ordinary for any of these facilities. A likely short remaining useful life for two units was noted in one case, but a longer remaining useful life would not alter that particular determination. It should be noted that, in order to show continued progress past 2018, the criteria will likely be different in the next reasonable progress assessment in order to maintain a continuous downward glidepath to ward natural background conditions by 2064. The facilities in North Carolina that have units that contribute at least one percent to visibility impairment at any Class I area in the State, or in neighboring States, were sent letters from the NCDAQ indicati ng that while no additional controls were identified during this reasonable progress assessment, the sources should be evaluating possible SO2 reduction strategies for the next round of regional haze SIP development. Those letters are contained in Appendix H.3.

EPA Findings : NCDAQ identified 34 emission units at eight facilities in North Carolina as having a significant contribution because they fell within the sulfate AOI of any Class I area and

ha d a one percent or greater contribution to the sulfate visibility impairment to at least one Class I area. Sixteen of the 34 emission units identified for a reasonable progress control analysis are EGUs subject to CAIR. As identified in the submittal (Ca rolina Power & Light and L V Sutton are now part of the Progress Energy system), these units are:

Carolina Power & Light Asheville Steam E

- 1 and E

- 2; Duke Energy Corporation

- Buck Steam Station G

- 4 and G

- 5; Duke Energy Corporation

– Dan River Station G

- 21; Duke Energy Corporation

- Cliffside Steam G

- 86, G

- 87, and G

- 88; Duke Energy Corporation

- Marshall Steam G

- 1 and G

- 2; Duke Energy Corporation

- Riverbend Steam G

- 17, G

- 19, and G

- 20;

L V Sutton Steam Electric Plant G

- 188; Progress Energy

- F Lee Plant G

- 2 and G

- 3.

Prior to the CAIR remand by the Court, EPA believed the State’s demonstration that no additional controls beyond CAIR for SO 2 for affected EGUs for the first implementation period to be acceptable

. However, as explained in Secti on III.C.1

– EPA Findings, the State’s demonstration regarding BART and reasonable progress for its EGUs, and other provisions in this SIP revision,

are based on CAIR

. In a separate action, EPA has proposed a limited disapproval of the North Carolina region al haze SIP because of deficiencies in the State’s regional haze SIP submittal arising from the remand by the D.C. Circuit to EPA of CAIR. See 76 FR 82219. Consequently,58

EPA is not taking action in this proposed rulemaking to address the State’s reliance on CAIR to meet certain regional haze requirements.

NCDAQ identified the following 18 emission generating units at six non

- EGU facilities that fall within the sulfate AOI of any Class I area and contribute one percent or more to visibility impairment:

Blue Ridge Paper Products

- Canton Mill G

- 24, G

- 25, G

- 26, G

- 31, G

- 32, G

- 65 and G

- 66; Cogentrix Kenansville Gen1; PCS Phosphate Company Inc.

- Aurora G

- 1032, G

- 1033, G

- 1034, G

- 1035; Weyerhaeuser Company

- New Bern G

- 42; Weyerhaeuser Company

– Plymouth.

Tw o of the units at PCS Phosphate are subject to BART. These two units are being shut down and replaced by a larger unit. The Permit for the facility requires these units to shut down once the new unit is fully operating. The two units at the Ecusta Busin ess Development Center shut down prior to the SIP being submitted.

NCDAQ has concluded that, at this time, the application of BART constitutes reasonable progress for three units at Blue Ridge Paper and thus, is not requiring any additional controls for reasonable progress. As discussed in EPA’s Reasonable Progress Guida nce document, since the BART analysis is based, in part, on an assessment of many of the same factors that must be addressed in establishing the RPG, EPA believes it is reasonable to conclude that any control requirements imposed in the BART determination also satisfy the RPG

- related requirements for source review in the first RPG planning period. 2 Thus, EPA proposes to agree with the State’s conclusions that the BART control evaluations satisfy reasonable progress for the first implementation period for t hese three units. NCDAQ has concluded that there are no cost

effective controls available for the remaining units at this time, and th erefore , is not requiring any

of these non

- EGU facilities to install additional controls for reasonable progress.

In gen eral, EPA also proposes to find North Carolina’s evaluation of the four statutory factors for reasonable progress to be reasonable. EPA believes that the North Carolina SIP ensures reasonable progress. EPA notes that given the emissions reductions result ing from CAIR, North Carolina’s CSA, and the measures in nearby states, the visibility improvements projected for the affected class I areas are in excess of that needed to be on the glidepath for each of the five Class

I areas in the S tate

.

In addition, EPA proposes to find that North Carolina fully evaluated, in terms of the four reasonable progress factors, appropriate control technologies available at the time of its analysis and applicable to these facilities. EPA also proposes to find t hat North Carolina consistently applied its criteria for reasonable compliance costs, and where appropriate, the State included justification for the other factors influencing the control determination.

2 M emorandum from William L. Wehrum, Acting Assistant Administrator for Air and Radiation, to EPA Regional Administrators, EPA Regions 1

- 10, Guidance for Setting Reasonable Progress Goals under the Regional Haze Program 4.2

- 4.3 ( July 1, 2007 ).

,59

The State also adequately presented its basis for c onsidering certain CAIR sources as part of its

r easonable p rogress analysis

. However, as explained in Section III.C.1

– EPA Findings, the State’s demonstration regarding BART and reasonable progress for its EGUs, and other provisions in this SIP revision, a re based on CAIR. Prior to the CAIR remand by the Court, EPA believed the
State’s demonstration that CAIR satisfies BART for SO 2 and NOx for affected EGUs for the first implementation period to be acceptable. In a separate action, EPA has proposed a limited disapproval of the North Carolina regional haze SIP because of deficiencies in the State’s regional haze SIP submittal arising from the remand by the D.C. Circuit to EPA of CAIR. See 76 FR 82219. Consequen tly, EPA is not taking action in this proposed rulemaking to address the State’s reliance on CAIR to meet certain regional haze requirements.60

III. Evaluation of Regional Haze Submittal

C . Long

- Term Strategy

C.4. Enforceability of Reasonable Progress M easures: The SIP needs to provide enforceable emissions limitations and schedules for compliance for each newly adopted measure needed to achieve the reasonable progress goal s

.

State Regional Haze Submittal

EPA Note : No newly adopted source specific measures were required to achieve the reasonable progress goals so no new rules or permits were included in this submittal

.

EPA Findings : EPA proposes to find that N orth C arolina has adequately addressed this provision

.

The following a ttachments were i ncluded in the submittal but were not relied upon for the reasonable progress demonstration and thus, were not assessed for enforceability: Attachment H.4

- North Carolina Department of Transportation Rule to Control Particulate Matter ; and

Attachment H.5

- North Carolina Hog Waste Legislation

.61

III. Evaluation of Regional Haze 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

NC SIP Narrative, Page 77:

Section 169A of the CAA directs States to assess certain large 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 con tribute 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, the USEPA published a revised final rule, including Appendix Y to 40 CFR Part 51, the Guidelines for BART Determinations Under the Regional Haze Rule (hereinafter referred to as the “BART Guidelines”) that provides guidance to states on determining which of these sources should be subject to BART, and how to determine B ART for each source.

A BART

- eligible source is one which has the potential to emit 250 tons or more of a visibility impairing air pollutant, was put in place between August 7, 1962 and August 7, 1977, and whose operations fall within one or more of 26 spe cifically listed source categories. Under the CAA, a BART determination is required for any BART

- eligible source that a State determines „„emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of 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 factors 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 techn ology.

The following is a list of facilities with BART

- eligible sources in North Carolina. See Appendix L for a detailed description of each BART

- eligible emission unit:

• Alcoa, Inc.

- Badin Works

• Blue Ridge Paper Products

– Canton Mill

• DAK Americas

– Cape Fear

• DAK Americas

– Cedar Creek

• Duke Energy

– Belews Creek Steam Station

• Duke Energy

– Cliffside Steam Station

• Duke Energy

– Marshall Steam Station

• Elementis Chromium

• International Paper

– Riegelwood Mill

• International Paper

– Roanoke R apids62 • Invista, S.A.R.L.

• PCS Phosphate Company Inc.

– Aurora

• Progress Energy

– Asheville Plant

• Progress Energy

– Roxboro Steam Electric Plant

• Progress Energy

– Sutton Plant

• Weyerhaeuser Company

– Plymouth

• Weyerhaeuser Company

– New Bern

The BART

- eligible sources were identified using the methodology in the BART Guidelines.

• One or more emissions 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 enforceable limits from all emission units identified in the previous two bullets emission units were 250 tons or more per year of any of these

visibil ity

- impairing pollutants: SO2, NOx, and PM10.

The BART Guidelines recommend addressing these visibility

- impairing pollutants: SO2, NOx, and particulate matter, and suggest that States use their best judgment in determining whether to

address VOC or ammoni a emissions. The NCDAQ addressed SO2 and NOx, and used particulate matter less than 10 microns in diameter (PM10) as an indicator for particulate matter to identify

BART

- eligible units, as the BART Guidelines recommend. As discussed in detail in Appendix L

, VISTAS modeling demonstrated that VOCs and ammonia from point sources are not visibility

impairing pollutants. For this reason, the NCDAQ did not evaluate emissions of VOCs and

ammonia in BART determinations.

NC SIP, Appendix L, P age 6 :

The USEPA provi ded guidance for identifying BART

- eligible sources in 40 CFR Part 51 Appendix Y. North Carolina followed this guidance in identifying its BART

- eligible sources. The North Carolina 2002 air emissions inventory was reviewed to determine the population of B ART Related Documentation potential BART

- eligible sources. The data were initially queried for any sources emitting SO2, NOx, PM10, VOC, or NH3. The data set was refined based on emissions,

whether emission units fit in any of the twenty

- six listed source categories for BART, and available date information obtained through review of permit and inspection reports and discussion with the NCDAQ‟s Permits Section and Regional Office staff familiar with the facilities. An information packet on BART was sent to and additional information was collected from the remaining sources regarding potential emissions and BART eligibility from the

s tandpoint of source category and date criteria. Through this iterative review process, the list of potential BART

- eligible sour ces was pared down to the seventeen BART

- eligible sources presented below

.

The facilities are scattered throughout the state with closest facility proximity to Class I areas ranging from 9.5 kilometers (km) to 186.8 km. The facilities include one primary aluminum facility, five pulp and paper facilities, six electric utilities, four chemical manufacturers, and one63

phosphate fertilizer manufacturer. One of the utilities, Progress Energy Asheville in Buncombe County, resides under the Western North Carolina local program jurisdiction.

Figure 3 8

. Figure 3

- 1. North Carolina BART

- Eligible Sources and Class I Areas.

Note: Labels represent facility status as of the time the map was created and reflects the first round of proposed exemptions. An additional seven of the seventeen facilities, including six utilities, were proposed for exemption in a second public notice in August 2007.

Note: During this process some facility names have changed. International Paper is now KapStone and Weyerhaeuser Plymouth is now Domtar. Facilities denoted as CP&L are now Progress Energy.

EPA Findings: EPA proposes to find that N orth C arolina has adequately addressed this provision.64

III. Evaluation of Regional Haze 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 no t violate the established threshold. The established exemption threshold for determining if a BART

- eligible source contributes to regional haze cannot exceed

0.5 deciviews.

State Regional Haze Submittal

Identification of BART S ource NC SIP Narrative, Pages 67

- 70:

Under the BART Guidelines, the NCDAQ may consider exempting some sources from BART if it is determined that they do not cause or contribute to visibility impairment in a Class I area. In accordance with the BART guidelines, the NCDAQ chose to perform 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 L. In accorda nce with the Guidelines, a contribution threshold of 0.5 dv was used for determining which sources were subject to BART. Detailed discussions about how a threshold of 0.5 dv meets the USEPA‟s BART guidelines can be found in Appendix L.

All of North Caroli na‟s BART

- eligible sources submitted exemption

- modeling demonstrations. Utilities subject to the CAIR Rule were only required to model for PM10. All remaining sources were required to model for SO2, NOx and PM10. Fifteen of the seventeen

sources were ab le to demonstrate exemption

. Additional details are available in Appendix L. Facilities found to be subject to BART must complete a BART analysis. The facilities that were able to demonstrate exemption from BART based on CALPUFF modeling conducted using th e VISTAS modeling protocol and the old IMPROVE equation were:

• Alcoa, Inc.

- Badin Works

• DAK Americas

– Cape Fear

• DAK Americas

– Cedar Creek

• Elementis Chromium

• International Paper

– Riegelwood Mill

• International Paper

– Roanoke Rapids

• Invista, S.A.R.L.

• Progress Energy

– Asheville Plant

• Progress Energy

– Sutton Plant

• Weyerhaeuser Company

– Plymouth

The facilities that were able to demonstrate exemption from BART based on CALPUFF modeling conducted using the VISTAS modeling protocol and the new IMPROVE equation were:

• Duke Energy

– Belews Creek Steam Station

• Duke Energy

– Cliffside Steam Station65 • Duke Energy

– Marshall Steam Station

• Progress Energy

– Roxboro Steam Electric Plant

• Weyerhaeuser Company

– New Bern

The NCDAQ has propos ed to exempt all of the units and no significant adverse comments were received during the public comment periods. For further details about the BART exemption modeling, please refer to Appendix L.

There were two sources that failed to model below the 0.5 dv threshold for exemption.

• Blue Ridge Paper Products

– Canton Mill

• PCS Phosphate Company Inc.

– Aurora

For the exemption modeling, both sources were required to model for SO2, NOx and PM10. PCS Phosphate used the new IMPROVE equation for their modeling; whereas Blue Ridge Paper used the old IMPROVE equation.

The following table provides the exemption modeling results for the North Carolina BART

eligible sources:

Source Class I Areas Distan ce to Class I

Area (km) Impact change

(dv)

– old

IMPROVE Impact change

(dv)

– new IMPROVE

Alcoa, Inc

– Badin Works Linville Gorge

James River Face Cape Romain Great Smoky Mountains Shining Rock 164

242

265

264

241 0.260

0.175

0.135

0.113

0.109

Blue Ridge Paper

Products

- Canton Shining Rock Great Smoky Mountains Linville Gorge Joyce Kilmer

- Slickrock

Cohutta 11

22

89

99

161 2.887

0.764

0.155

0.134

0.095

DAK Americas

- Cape

Fear Swanquarter Cape Romain 187

182 0.19

0.16

DAK Americas

- Cedar

Creek Swanquarter Cape Romain Linvelle Gorge

James River Face 219

216

295

291 0.08

0.06

0.05

0.04 Duke Energy

- Belews

Creek Linville Gorge

James River Face

Shenandoah Great Smoky Mountains Shining Rock 180

140

215

290

280 0.31 0.26

0.24

0.20

0.09

0.09

Duke Energy

- Cliffside Linville Gorge Shining Rock Great Smoky Mountains

Cohutta Joyce Kilmer

- Slickrock 60

105

130

265

205 0.29 0.25

0.13

0.09

0.05

0.05 Duke Energy

- Marshall Linville Gorge 95 0.52 0.4666 James River Face Shining Rock Great Smoky Mountains Joyce Kilmer

- Slickrock 240

180

200

280 0.15

0.15

0.11

0.07

Elementis Chromium Swanquarter Cape Romain 170

200 0.185

0.129 International Paper

Riegelwood Swanquarter Cape Romain 210

150 0.112

0.109 International Paper

Roanoke Rapids Swanquarter

Shenandoah

James River Face 164

204

200 0.305

0.248

0.234
Invista, S.A.R.L Swanquarter Cape Romain 184

187 0.286

0.215 PCS Phosphate Company

- Aurora Swanquarter 32 1.319 0.976

Progress Energy

Asheville Shining Rock Great Smoky Mountains Linville Gorge Joyce Kilmer

- Slickrock

Cohutta 26

50

68

125

185 0.372

0.265

0.143

0.042

0.031 Progress Energy

Roxboro James River Face

Shenandoah Linville Gorge Swanquarter Dolly Sods 113

168

257

264

265 0.58 0.483

0.304

0.214

0.152

0.069 Progress Energy

- Sutton Swanquarter Cape Romain 185

183 0.156

0.148 Weyerhaeuser Company

Plymouth Swanquarter

Shenandoah

James River Face 73

300

300 0.336

0.087

0.068 Weyerhaeuser Company

New Bern Swanquarter Cape Romain 65

300 0.722

0.211 0.367

Figure 3 9

. BART Exemption Modeling Results

In total, fifteen of North Carolina‟s seventeen BART

- eligible sources were able to demonstrate that they did not cause or contribute to visibility impairment in any Class I area within 300 km of

the source. Six sources us ed the new IMPROVE equation in efforts to demonstrate exemption. (Additional information related to the BART modeling is presented in Appendix L.)

NC SIP, Appendix L, Page 6:
North Carolina‟s BART

- eligible sources were presumed to be subject to BART but were provided the opportunity to submit modeling demonstrations showing that they did not contribute to visibility impairment, i.e., had less than 0.5 dv impact, on any Class I area within 300 km and thus could be exempt.

Use of the New IMPROVE Algorithm and Sea Salt ( NC SIP, Appendix L, Page L

- 25) During the regional haze SIP development process, the IMPROVE Steering Committee made recommendations for a new IMPROVE equation to determine background conditions. VISTAS

contracted Dr. Ivar Tombach to develo p a post processor to allow CALPOST outputs to be used67

with the new IMPROVE equation. A discussion of the rationale for use of the new IMPROVE equation follows is included in Appendix B.

Data Access

– EPA Note : Due to the excessive size of data and mode ling 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 of the SIP submittal

.

EPA Findings : EPA proposes to find that N orth C ar olina has adequately addressed the development of technical analyses to support the BART assessment provision. North Carolina requested that its sources follow the VISTAS modeling protocol in development of their site specific protocols and explain any de viations that they proposed to use. In the site

- specific modeling demonstrations submitted by N orth C arolina ’s BART

- eligible sources, the CALPUFF model incorporating three years of pre

- processed MM5 meteorological data was used to evaluate

the deciview change compared to natural background conditions at each of the Class I areas within 300 km of the source. Both the 4 km and 12 km MM5 datasets prepared by VISTAS were

used. Facilities submitted site

- specific modeling protocols and subsequent modeling

d emonstrations based upon the VISTAS modeling protocol. The site

- specific protocols are found

in Attachment H

- 5 and the demonstrations are found in Attachment L

- 4 of the SIP submittal

. The protocols and demonstrations were reviewed by the State of North C arolina. The individual facility modeling demonstrations were shared with both EPA and FLMs for their review and comment. The resulting comments were in turn shared with the facilities. The S tate worked throughout the process to resolve many of the issue s and concerns reflected in their comments. Sources demonstrating less than a 0.5 deciview impact were considered exempt. Sources contributing 0.5 deciview impact or greater were considered subject to BART and were required to proceed to an analysis of w hat control measures, if any, constitute BART for the source.

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

- eligible sources and those sources subject to BART controls. EPA proposes to find that the State successfully developed and p rovided the technical analyses to support the BART assessment provi sion for the non

- CAIR sources, and that t he State appropriately identified the BART

- eligible sources and those sources subject to BART controls. The State developed and provided the techni cal analyses to support the BART assessment provision for the non

- CAIR sources. However, North Carolina opted 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 its EGUs, and other provisions in this SIP revision, are based on CAIR

. In a separate action proposing limited disapproval of the regional haze SIPs of a number of states, EPA noted that these states relied on the trading programs of CAIR to satisfy the BART requirement and the requirement for a LTS sufficient to

achieve the state

- adopted RPGs. See 76 FR 82219 (December 30, 2011). In that action, EPA proposed a limit ed disapproval of North Carolina’ s regional haze SIP submittal insofar as the SIP relied on CAIR. For that reason, EPA is not taking action on that aspect of North Carolina’s regional haze SIP in this action.

CALPUFF MODELING68

EPA proposes to find that t he CALPUFF 3 modeling system was appropriately applied by NCDAQ in the assessment of visibility impairment in Class I areas for specific sources 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 regulatory niche for the CALPUFF modeling system in 40 CFR, p art 51, Appendix W: Guideline on Air Quality Models (Ap pendix W) is for compliance with non

- attainment New Source Review (NNSR)/ and Prevention of Significant Deterioration (PSD) permitting requirements for long range transport (i.e., greater than 50 KM) applications at Class I areas. There is no preferred mo del for assessing visibility impact under BART. However, it is appropriate for the State of North Carolina 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) states 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 vers ion (either ver. 5.754 or 5.756) has been made by

EPA Region 4. However, there has been an implied acceptance of the VISTAS CALPUFF

version as EPA Region 4 has reviewed and commented on the VISTAS BART Modeling

Protocol and the source

- specific modeling pr otocols and reports that were developed by the North

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, trad e groups, lawyers and other interested parties, before 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

- specific protocols and their subsequent ex emption 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 Modeling 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. EPA Headquarters and other EPA r egional o ff ices 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 c hange 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

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

corre sponding versions of CALMET, CALPOST, 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 a re available from the model developer on the following website: http://www.src.com/verio/download/download.htm

.69

position on the new methodology. Use of the methodology by BART sources in s tates located in

other EPA Regions would require consultation with the appropriate regional office. EPA required the State of North Carolina to submit a request to the EPA Region 4 Regional Administrator requesting the use of this new methodology for the BART CALPUFF

- based

mode ling. A March 19, 2007

, l e tter justifying the need for this approach was sent to EPA

, and approval from the Regional Administrator was provided to the S tate on May 11, 2007 . The methodology and S tate and Region 4 letters are located in the S tate’s submittal (Appendix L.8)

.

The new methodology uses a spreadsheet developed by VISTAS to post

- process the visibility modeling output from the CALPUFF and CALPOST models. The spreadsheet implements the new IMPROVE equation for calculating visibility impact s 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 modeling approach and should meet the requirements in Section 3.2 of Appendix W, Guideli ne 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 need 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 the equation. Based on the demonstration provided in North Carolina’s letter of

Marc h 7, 2007

, EPA approved the State’s request.

Contribution Threshold With respect to the contribution threshold used in the CALPUFF modeling, the S tate was also required to justify its choice of the 0.5 deciview contribution threshold for exempting sources from BART eligibility. North Carolina used a contribution threshold of 0.5 deciview for determining which sources are subject to BART. NCDAQ concluded that, considering the results of the visibility impacts mo deling conducted, a 0.5 deciview threshold was appropriate in this situation and a lower threshold was not warranted for the following reasons. The State demonstrated that there are a limited number of in and out of state sources that impact the Class I

a reas in the State, and that there are a limited number of sources in close proximity to each of the affected Class I areas. Additionally, the majority of the visibility impacts were well below 0.5 deciview. Also, even though several sources impacted each Class I area, the overall impacts were low from the sources. EPA is proposing to agree with North Carolina that the overall impacts of

these sources are not sufficient to warrant a lower contribution threshold and that a 0.5 deciview threshold was approp riate in this instance.

References used in the EPA review:

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

.

2. May 11, 2007

, letter from James I. Palmer, Regional Administrator, EPA Region 4, to B.
Keith Overcash, P.E. Director , North Carolina Department of Environmental and Natural

Resources

, re: “ Approval for the use of the VISTAS methodology 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.70

4. IWAQM. 1998. Interagency Workgroup on Air Quality Modeling (IWAQM) Phase 2 Summary Report 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 memorandum from Dennis Atkinson to Kay T. Prince on Dispersion C oefficients for Regulatory Air Quality Modeling in CALPUFF.

7. Additional Regional Haze Questions, EPA, September 27, 2006 Revision. Answers to questions that E PA received from various States and Regional Planning Organizations (RPOs) related to the submiss ion of regional haze SIPs under the program described 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.71

III. Evaluation of Regional Haze 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 NC SIP Narrative, Pag e 70:

Six of North Carolina‟s BART

- eligible sources are EGUs subject to the North Carolina C lean

S mokestacks A ct

.

• Duke Energy

– Belews Creek Steam Station

• Duke Energy

– Cliffside Steam Station

• Duke Energy

– Marshall Steam Station

• Progress Energy

– Asheville Plant

• Progress Energy

– Roxboro Steam Electric Plant

• Progress Energy

– Sutton Plant

Under the Act, Duke Energy and Progress Energy must reduce their NOx emissions by 77 percent by 2009 and SO2 emissions by 73 percent by 201 3. These sources have already installed or are installing scrubbers to reduce SO2 emissions and to reduce NOx emissions Selective Catalytic Reduction (SCR) and Selective Non

- Catalytic Reduction (SNCR). The EGUs are required by the

statute to submit annual update to their compliance plans to meet these requirements. The Duke Energy and Progress Energy compliance plans from the June 1, 2007 report Implementation of

the Clean Smokestacks Act summarize the status of control on these EGUs and are attached to App endix L.

The USEPA has determined that, as a whole, the CAIR cap

- and

- trade program improves visibility more than implementing BART for individual sources in states affected by CAIR. A State that opts to participate in the CAIR program under 40 CFR 96.201

- .224 (Subpart AAA through EEE) need not require BART

- eligible EGUs subject to CAIR to install, operate, and maintain BART for SO2 or NOx emissions. Given that all BART

- eligible units are installing scrubbers and NOx controls, and since North Carolina is pa rticipating in CAIR and accepts the US EPA‟s overall finding that CAIR “substitutes” for BART for NOx and SO2, North Carolina‟s EGUs were allowed to submit BART exemption modeling demonstrations for PM emissions only. All six EGUs demonstrated that they do not contribute to visibility impairment in any Class I area.

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

- eligible sources

and those so urces subject to BART controls. However, North 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 regarding

BART and reasonable progress for its EGUs, and other provisions in this SIP revision, are based

on CAIR

. In a separate action, EPA has proposed a limited disapproval of the N orth Carolina72

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 not proposing to take act ion in this rulemaking on issues associated with North Carolina’s reliance on CAIR in its regional haze SIP.73

III. Evaluation of Regional Haze Submittal

D . Best Available Retrofit Technology (BART) Requirements

D.4. Source Specific 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 (unless 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 t he technolo gy available, t he costs of compliance, t he energy and non

- air quality environmental impacts of compliance, a ny pollution control equipment in use at the source, t he remaining useful life of the source, and t he degree of improvement in visibility that may r easonably be anticipated to result from the use of such technology.

State Regional Haze Submittal NC SIP Narrative, Page 70:

Two sources, PCS Phosphate in Aurora, North Carolina and Blue Ridge Paper in Canton, North Carolina, were unable to demonstrate a contribution of less than 0.5 dv at all Class I areas within 300 km from their BART

- eligible sources. These two facilities are considered to be “subject to BART” and were required to submit permit applications containing their evaluation of potential BAR T options and proposed BART determinations. These facilities submitted permit applications including their proposed BART determinations in the Fall of 2006. The proposed BART determinations have been reviewed by the NCDAQ (pages L.10

- 280

- 697) and it was

d etermined that BART is no additional controls at either facility. For a more detailed discussion of the BART determinations, please see Appendix L.10.

EPA Findings : Two BART

- eligible sources (i.e., PCS Phosphate and Blue Ridge Paper) failed to

model below the 0.5 deciview threshold for BART exemption. These two facilities are considered to be subject to BART and submitted permit applications including their proposed BART determinations in the Fall of 2006. The proposed BART determinations were reviewed by the NCDAQ

, and the State determined that BART is no additional control at either facility. The BART determinations resulted in a new Title V permit with no additional control measures for Blue Ridge Paper and a new Title V permit with a Prevention of Significant De terioration (PSD) netting analysis for SO 2 for PCS Phosphate.

EPA proposes to find that N orth C arolina has appropriately addressed this provision for Blue Ridge Paper. Subsequent to this submittal

, PCS Phosphate submitted a permit request to replace

the two BART eligible units with a new, larger unit. The facility netted out of PSD review for

SO 2

. NCDAQ has modified the PCS Phosphate operating permit allowing them to replace the

two BART

- subject sulfuric acid plants, units 3 and 4, with a new, larger u nit, Unit #7. Appendix

Y of 40 CFR p art 51 indicates the shutdown of a source subject to a BART determination should be assured by an enforceable restriction preventing further operation. The permit requires PCS Phosphate to shut down units 3 and 4 when unit 7 is fully operational. Construction is complete

on new unit 7 and the two units have been taken out of operation. N orth C arolina has issued a new permit for PCS Phosphate that replaces the BART eligible units. Since the BART eligible

units will be eliminated and the new unit is not subject to BART, no additional analysis is required for BART.74

III. Evaluation of Regional Haze 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 opera te 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 pr ocedures to ensure such equipment is properly operated and maintained.

State Regional Haze Submittal

EPA Note : No new limitations were adopted for BART so no new limits were included for

review.

EPA Findings : The State determined that for Blue Ridge P aper, BART is no control based on its

evaluation of the five CAA factors. Consequently, the BART process will result in no new applicable requirements for the source, and this determination does not need to be reflected in the title V permit. EPA proposes to find that t he determination is appropriately described in the SIP.

For PCS Phosphate, t he shutdown of units 3 and 4 is enforceable through provisions added to the facility’s operating permit.75

III. Evaluation of Regional Haze Submittal E. Coordination of Regional Haze and RAVI Requirements

The State must revise its SIP to provide for review and revision of a coordinated long

- term strategy for addressing reasonably attributable and regional haze visibility impairment.

State Regional Haz e Submittal

North Carolina did not explicitly address this requirement regarding a coordinated RAVI and regional haze long

- term strategy . However, NCDAQ has included provisions in this SIP submittal that updated the elements subject to the RAVI long

- term strategy requirements (including monitoring and new source review (NSR)):

NC SIP Narrative, Pages 95

- 97 :

Monitoring Strategy The primary monitoring network for regional haze, both nationwide and in North Carolina, is the

IMPROVE network. Given that IMPROVE monitoring data from 2000

- 2004 serves 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 North Carolina intends to rely on the IMPROVE network for complying with the regional haze monitoring requirement in the Regional Haze Rule.

There are currently 3 IMPROVE s ites in North Carolina (2 at distinctly different locations in the mountains and one on the coast). In addition, as Table 9.0

- 1 shows, an IMPROVE site just across the border in Tennessee serves as the monitoring site for both the Great Smoky Mountains

Nati onal Park and Joyce Kilmer

- Slickrock Wilderness Area, both of which lie partly in Tennessee and partly in North Carolina.

In addition to the IMPROVE measurements, some ongoing long

- term limited monitoring supported by Federal Land Managers provides additi onal insight into progress toward regional haze goals. North Carolina benefits from the data from these measurements, but is not responsible for the funding decisions to maintain these measurements into the future. Such

measurements include:

• Web cameras operated by the National Park Service at Look Rock, Tennessee and Purchase Knob, North Carolina in Great Smoky Mountains National Park and by the United States Forest Service at Frying Pan Mountain in the Shining Rock Wilderness Area.

• An integrating nep helometer for continuously measuring light scattering, operated by the National Park Service at Look Rock, Tennessee.

• A Tapered Element Oscillating Microbalance (TEOM) for continuously measuring PM2.5 mass concentration, operated by the National Park Service at Look Rock, Tennessee.

Additional haze

- related measurements were made in North Carolina in 2002

- 2005 as part of special monitoring studies by the VISTAS regional planning organization. These studies were

intended to better understand source cont ributions to PM2.5 mass and visibility. They included76

continuous monitoring of sulfate, nitrate, and carbon to better understand daily trends in PM2.5, detailed analyses of carbon collected on filters to identify source contributions to carbon, and

additio nal 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 the NCDAQ.

The continuous nitrate monitor continues to operate at the Millbrook site in Raleigh and the NCDAQ intends to operate this monitor as long as funds allow. Additionally, a second continuous nitrate monitor is in operation at the Rockwell monitoring site in Rowan County. Again, the NCDAQ plans to operate this monitor indefinitely as long as funds allow. The NCDAQ began operating a continuous sulfate monitor at the Millbrook in August 2007, and expect to have one at the Rockwell sites in January 2008. The NCDAQ is also operating a 5400 R&P monitor for organic, total, and elemental car bon at the Millbrook site. The 5400 R&P monitor is near the end of its lifecycle, but the NCDAQ plans to operate it as long as it can be kept functional or until money is available to purchase a better technology should such a technology become available. VISTAS also transferred a 5400 R&P monitor from the Look Rock special studies location, but the unit is inoperable. The NCDAQ used it for parts for the Millbrook unit, thus, a 5400 R&P unit is not available for the Rockwell site. At this time, the NCDAQ do es intend to purchase one to place there due to the short lifecycle of the unit and the various operating issues.

In February 2008, the NCDAQ will finish a year

- long black carbon study in Hickory with the

aethalometer that was used at the Millbrook site. Depending on the results of the study, this monitor may remain at the Hickory site, return to the Millbrook site, or go to the Rockwell site. The NCDAQ will use the continuous speciation data from the sites discussed above to further the understanding of b oth PM2.5 and visibility formation and trends in North Carolina. The NCDAQ will operate the units discussed above as long as funds allow.

In addition, the NCDAQ and the local air agencies in the State operate a fairly comprehensive PM2.5 network of the fi lter based Federal reference method monitors, continuous mass monitors (TEOMs), filter based speciated monitors and the continuous speciated monitors described above. A map of the various locations around the State is included in Figure 9.0

- 1. These PM2.5 measurements help the NCDAQ 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.

NC SIP Narrative, Page s 100

- 101 :

Ten Year Plan and Five Year Plan Update 40 CFR 51.308(f) requires the NCDAQ to revise its regional haze implementation plan and submit a plan revision to the USEPA by July 31, 2018 and every ten years thereafter. In accordance with the requirements listed in Section 51.308(f) of the federal rule for regional haze, North Carolina commits to revising and submitting this regional haze implementation plan by July 31, 2018 and every ten years thereafter.

In addition, 51.308(g) requires periodic reports evaluating progress towards the reasonable

progr ess goals established for each mandatory Class I area. In accordance with the requirements77

listed in 51.308(g) of the federal rule for regional haze, the NCDAQ commits to submitting a

report on reasonable progress to the USEPA every five years following th e 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 reasonable progress goal for each mandatory Class I

area located within North Carolina and in each mandatory Class I area located outside North

Carolina which may be affected by emissions from within North Carolina

.

The requirements listed in 51.308(g) include the following:

1. Description of the status of implementation; 2. Summary of emission reduct ions achieved thus far, including especially the status of implementation of the CAIR compliance plans for EGUs compared to the control assumed in the modeling. 3. Assessment of changes in visibility conditions at each Class I area (current vs. baseline)

, expressed as 5

- year averages of annual values for 20% best and worst days; 4. Analysis of emission changes over the 5

- year period, identified by source or activity, 5. Analysis of any significant changes in or out of the State which have impeded progress ; 6. Assessment of the sufficiency of the implementation plan to meet Reasonable progress goals; 7. Review and any modifications to our visibility monitoring plan.

All requirements listed in 51.308(g) shall be addressed in the SIP revision for reasonable progress. In particular, the NCDAQ recognizes that the 2018 projections of EGU controls from the IPM runs represent one solution to how the CAIR requirements will be met. By the time of the first periodic report, the NCDAQ anticipates that the actual compl iance strategy for the various utility companies will be much more defined. An assessment of those actual compliance plans will be done for the first periodic report.

NC SIP Narrative, Page 101 :

NSR/PSD The NCDAQ believes that its New Source Review regul ations for both nonattainment areas as well as the prevention of significant deterioration will address emissions from new sources that may located near a Class I area, or increased emissions from major modifications to existing

sources. In addition to the NCDAQ regulations that would govern these sources, consultation with the FLMs is also required for sources that are subject to the new source review regulations. Page 101

Consultation The NCDAQ also commits to ongoing consultation with the FLMs throughout the implementation process, including annual discussion of the implementation process and the most recent IMPROVE monitoring data and VIEWS data

. .

EPA Findings : EPA proposes to find that this regional haze submittal adequately supplements

and augments North Carolina’s RAVI visibility provisions to address regional haze, updating the monitoring and LTS provisions as summarized below in this section. Under EPA’s RAVI regulations, the RAVI portion of a state SIP must address any integral vistas i dentified by the FLMs pursuant to 40 CFR 51.304. See 40 CFR 51.302. An integral vista is defined in 40 CFR78

51.301 as a “view perceived from within the mandatory Class I Federal area of a specific landmark or panorama located outside the boundary of the m andatory 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 North Carolina. In addition, the Class I areas in

North Carolina are neither experiencing RAVI nor are any of its sources affected by the RAVI provisions. Thus, the December 17, 2007, North Carolina regional haze SIP submittal does not explicitly address the two requirements regarding coordination of the regional haze with the

RA VI LTS and monitoring provisions. North Carolina has, however, previously made a commitment to address RAVI should the FLMs certify visibility impairment from an individual

source. 4 EPA proposes to find that this regional haze submittal appropriately sup plements and augments North Carolina’s RAVI visibility provisions to address regional haze by updating the monitoring and LTS provisions as summarized below.

In its December 17, 2007, submittal, NCDAQ updated its visibility monitoring program and develope d a LTS to address regional haze. Also in this submittal, NCDAQ affirmed its commitment to complete items required in the future under EPA’s RHR. Specifically, NCDAQ 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 LTS regulations, NCDAQ commit ted to submitting a report to EPA on progress towards the RPGs for each mandatory Class I area located within North Carolina and for each mandatory Class I area located outside North Carolina that may be affected by emissions from within North Carolina. T he 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 regional haze SIP.

See 40 CFR 51.308(g). Co nsistent with EPA’s monitoring regulations for RAVI and regional haze, North 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 North Carolina new source review (NSR) rules, previously approved in the State’s SIP, continue to provide a framework for review and coordination with the FLMs on new sources and major modifications to existing sources subject to the NSR regulations which may have an adverse impact on visibility in either form (i.e., RAVI and/or regional haze) in any

Class I area.

4 North Carolina submitted its visibility SIP revision s address ing RAVI on April 15, 1985, which EPA approved on January 21, 1986 (51 FR 2695).79

III. Evaluation of Regional Haze Submittal

F

. Monitoring Strategy and Other Implementation Requirements Monitoring Strategy: The SIP must include 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 affect ed 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 following:

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 monito ring 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 encou raged.

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

State Regional Haze Submittal NC SIP Narrative, Pages 95

- 97:

Such monitoring is intended to provide the data needed to satisfy four objectives: 1. Track the expected visibility improvements resulting from emissions reductions identified in this SIP. 2. Better understand the atmospheric processes of importance to haze 3. Identify chemical species in the ambient particulate matter a nd relate them to emissions from sources 4. Evaluate regional air quality models for haze and construct relative response factors for using those models

The primary monitoring network for regional haze, both nationwide and in North Carolina, is the

IMPROV E network. Given that IMPROVE monitoring data from 2000

- 2004 serves 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 provi de the only long

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

There are c urrently 3 IMPROVE sites in North Carolina (2 at distinctly different locations in the mountains and one on the coast). In addition, as Table 9.0

- 1 shows, an IMPROVE site just across the border in Tennessee serves as the monitoring site for both the Great Smoky Mountains80

National Park and Joyce Kilmer

- Slickrock Wilderness Area, both of which lie partly in Tennessee and partly in North Carolina.

In addition to the IMPROVE measurements, some ongoing long

- term limited monitoring supported by Federal Land Mana gers provides additional insight into progress toward regional haze goals. North Carolina benefits from the data from these measurements, but is not responsible for the funding decisions to maintain these measurements into the future. Such

measurements inc lude:

• Web cameras operated by the National Park Service at Look Rock, Tennessee and Purchase Knob, North Carolina in Great Smoky Mountains National Park and by the United States Forest Service at Frying Pan Mountain, in the Shining Rock Wilderness Area.

• An integrating nephelometer for continuously measuring light scattering, operated by the National Park Service at Look Rock, Tennessee.

• A Tapered Element Oscillating Microbalance (TEOM) for continuously measuring PM2.5 mass concentration, operated by t he National Park Service at Look Rock,

Tennessee.

Additional haze

- related measurements were made in North Carolina in 2002

- 2005 as part of special monitoring studies by the VISTAS regional planning organization. These studies were

intended to better under

stand source contributions to PM2.5 mass and visibility. They included continuous monitoring of sulfate, nitrate, and carbon to better understand daily trends in PM2.5, detailed analyses of carbon collected on filters to identify source contributions to ca rbon, 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 the NCDAQ.

The continuous nitrate monitor continues to operate at the Millbrook site in Raleigh and the NCDAQ intends to operate this monitor as long as funds allow. Additionally, a second continuous nitrate monitor is in operation at the Rockwell monitoring site in Rowan County. Again, the NCDAQ plans to operate this monitor indefinitely as long as funds allow. The NCDAQ began operating a continuous sulfate monitor at the Millbrook in August 2007, and expect to have one at the Rockwell sites in January 2008. The NCDA Q is also operating a 5400 R&P monitor for organic, total, and elemental carbon at the Millbrook site. The 5400 R&P monitor is near the end of its lifecycle, but the NCDAQ plans to operate it as long as it can be kept functional or until money is available to purchase a better technology should such a technology become available. VISTAS also transferred a 5400 R&P monitor from the Look Rock special studies location, but the unit is inoperable. The NCDAQ used it for parts for the Millbrook unit, thus, a 5400 R&P unit is not available for the Rockwell site. At this time, the NCDAQ does intend to purchase one to place there due to the short lifecycle of the unit and the various operating issues.

In February 2008, the NCDAQ will finish a year

- long black carbon study in Hickory with the aethalometer that was used at the Millbrook site. Depending on the results of the study, this monitor may remain at the Hickory site, return to the Millbrook site, or go to the Rockwell site.81

The NCDAQ will use the continuous spec iation data from the sites discussed above to further the understanding of both PM2.5 and visibility formation and trends in North Carolina. The NCDAQ will operate the units discussed above as long as funds allow.

In addition, the NCDAQ and the local air agencies in the State operate a fairly comprehensive PM2.5 network of the filter based Federal reference method monitors, continuous mass monitors (TEOMs), filter based speciated monitors and the continuous speciated monitors described above. A map of the various locations around the State is included in Figure 9.0

- 1. These PM2.5 measurements help the NCDAQ 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.

Figure 40 . PM2.5 Monitoring Sites in NC

The IMPROVE measurements are central to North Carolina‟s regional haze monitoring 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 North Carolina would jeopardize the State‟s ability to demonstrate reasonable progress toward visibility improvement in some of its Class I areas. In particular, North Car olina‟s regional haze strategy relies on emission reductions that will result from the CAIR and the CSA, which occur on different time scales and will most likely not be spatially uniform. Monitoring at every Class I area is important to document the diffe rent air quality responses to the emissions reductions. Because each of the current IMPROVE monitors in North Carolina represents a different airshed, reduction of the IMPROVE network by shutting down one of these monitoring sites impedes tracking progress at reducing haze at the affected Class I area. In the event this occurs,82

North Carolina, in consultation with the USEPA and relevant Federal Land Managers, will develop 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 IMPROVE monitoring network will be used nearly continuously for preparing the 5

- year progr ess 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 sites needs to be readily accessible and to be kept up to date. Presumably, IMPROVE

will con tinue 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 provi de ready access to the IMPROVE data and data analysis tools. North Carolina is encouraging VISTAS and the other RPOs to maintain VIEWS or a similar data management system to facilitate analysis of the

IMPROVE data.

EPA Findings : EPA proposes to find that N orth C arolina has adequately addressed this provision.83

III. Evaluation of Regional Haze Submittal

G

. Emission Inventory (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 NC SIP Narrative, Pages 18

- 24:

Emission Inventory Chapter 4 discusses the emission inventory. An inventory was developed for the baseline year 2002 and projected to 2018. The pollutants inventoried include VOCs, NOx, PM2.5, coarse particulate (PM10), NH3 and SO2. The baseline emissions inventory for 2002 was developed for North Carolina following the methods described in Appendix D.

There are five different emission inventory source classifications: stationary point and area sources, off

- road and on

- road mobile sources, and biogenic sources

. EPA‟s MO BILE6.2 and NONROAD2005 emissions models were used to develop the onroad and nonroad emissions and the Carnegie Mellon University ammonia models was used in the development of ammonia

emissions. Stationary point sources are those sources that emit greater than a specified tonnage per year, with data provided at the facility level. Electric generating utilities and industrial sources are the major categories for stationary point sources. Stationary area sources are those

sources whose individual emissions a re relatively small, but due to the large number of these sources, the collective emissions from the source category could be significant (i.e., dry cleaners, service stations, agricultural sources, fire emissions, etc.). These types of emissions are estim ated on a countywide level. Off

- road (or non

- road) mobile sources are equipment that can move but do not use the roadways, i.e., lawnmowers, construction equipment, railroad locomotives, aircraft, etc. The emissions from these sources, like stationary area sources, are estimated on a countywide level. On

- road 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 countywide level. Biogenic sources are the natural sources like trees, crops, grasses and natural decay of plants. The emissions from these sources are estimated on a countywide level. In addition to the various source classifications, there are also various types of

emiss ion inventories. The first is the actual base year inventory. This inventory is the base year emissions that correspond to the meteorological data used, which for this modeling effort is data from 2002. These emissions are used for evaluating the air quali ty model performance. The second type of inventory is the typical base year inventory. This inventory is similar to the actual base year inventory, except that for sources whose emissions change significantly from year to year, a more typical emission val ue is used. In this modeling effort, typical emissions were developed for the electric generating units (EGUs) and the wildland fire emissions. The air quality modeling is run using the typical base year inventory and the future year inventory. The

results from these two runs are then used to calculate relative reduction factors. These relative84

reduction factors are used to estimate the future year visibility estimates that are used to demonstrate reasonable progress toward visibility goals.

The North Ca rolina state emissions inventory data used in the modeling for 2002 and 2018 are presented in the following tables. Reductions related to the BART and reasonable progress analyses were not included in the photochemical grid modeling and are not represented in the tables. More detailed discussion of the emissions inventory development is contained in Appendices D and H.

Figures 41 and 4 2 . North Carolina state emissions inventory data used in the modeling for

2002 and 2018

NC SIP Narrative, Page 101:

All requirements listed in 51.308(g) shall be addressed in the SIP revision for reasonable progress. In particular, the NCDAQ recognizes that the 2018 projections of EGU controls from the IPM runs represent one solution to how the CAIR requirements will be met. By the time of the first periodic report, the NCDAQ anticipates that the actual compliance strategy for the various utility companies will be much more defined. An assessment of those actual compliance plans will be done for the first periodic report.

EPA Findings : EPA proposes to find that N orth C arolina has adequately addressed this provision.85

I V. Conclusion

EPA is proposing a limited approval of a revision to the North Carolina SIP submitted by the State of North 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.