1

----------------------------------------------------------------------------------------------------------------------------- - Technical Support Document (TSD)

Florida Area Designations For the

2010 SO 2 Primary National Ambient Air Quality Standard

Summary

Pursuant to section 107(d) of the Clean Air Act (CAA), EPA must designate areas as either

“nonattainment

, ” “attainment

, ” or “unclassifiable” for the 2010 1

- hour su lfur dioxide (SO 2 ) primary national ambient air quality standard (NAAQS). The CAA defines a nonattainment area as one that does not meet the NAAQS or that contributes to poor air quality in a nearby area that does not meet the NAAQS. Table 1 below identifi es the counties or portions of counties (or areas of Indian Country ) in

Florida that EPA is initially designating “nonattainment” based on monitored violations

. EPA is not yet prepared to designate other areas in Florida.

Table 1. Nonattainment Area Designations for Florida

Area Florida Recommended Designation of Areas/Counties EPA’s Designation of

Areas/Counties

Hillsborough County Area Hillsborough County (partial) Nonattainment Nonattainment

Nassau County Area Nassau County (partial) Nonattainment Nonattainment

Background

On June 2, 2010, EPA revised the primary SO 2 NAAQS (75 FR 35520, June 22, 2010) by establishing a

new 1

- hour standard at a level of 75 parts per billion (ppb) which is met at an ambient air quality monitoring site when the 3

- year average of the annual 99 th percentile of the daily maximum 1

- hour average concentration is less than or equal to 75 ppb , as determined in accordance with Appendix T of 40 CFR part 50

. 40 CFR 50 .17(a)

- (b). EPA has determined that this is the level necessary to provide protection of public health with an adequate margin of safety, especially for children, the elderly and those with asthma. These groups are particularly susceptible to the health effects associated with breathing SO 2 . The Agency is revoking the two prior primary standards of 140 ppb evaluated over 24

- hours, and 30 ppb evaluated over an entire year because the standards will not add additional public health protection given a 1

- hou r standard at 75 ppb. Accordingly, EPA is not designating areas in this process on the basis of either of these two prior primary standards. Similarly, the secondary standard for

SO 2 has not been revised, so EPA is not designating areas in this process o n the basis of the secondary

standard.2

EPA’s SO 2 Designation Approach

Section 107(d) of the CAA provides that not later than 1 year after promulgation of a new or revised NAAQS, state Governors may submit their recommendations for designations and boundaries to EPA.

This deadline was in June 2011. Section 107(d) also requires EPA to provide a notification to states of

no less than 120

- days prior to promulgating an initial area designation that is a modification of a state’s

recommendation. EPA has reviewed the State’s recommendations and has notified the Governor through a letter signed by the Regional Administrator of any intended modifications. While language in section 107 specifically address es states, we follow ed the same process for the tribal government s
, pursuant to section 301(d) of the CAA and Tribal Authority Rule (40 CFR Part 49). Therefore, we are designat ing tribal areas , in consultation with the tribal government s , on the same sche dule as state designations

. Florida does not have any tribal areas affected by this designation. If a s tate or tribal government do es not submit designation recommendations, EPA is promulgat ing the designations that it deems appropriate. If a state or t ribal government disagree s with EPA’s intended area designations as released on February 7, 2013

, it ha d an opportunity to demonstrate why any proposed modification wa s inappropriate.

Designations guidance was issued by EPA through a March 24, 2011, memorandum from Stephen D. Page, Director, U.S. EPA, Office of Air Quality Planning and Standards, to Air Division Directors, U.S. EPA Regions I

- X. This memorandum identifies factors EPA in tends to evaluate in determining boundaries for areas designated nonattainment. These 5 factors include: 1) a ir quality data; 2)

e missions and emissions

- related data (location of sources and potential contribution to ambient SO 2 concentrations); 3) m eteorology (weather/transport patterns); 4) g eography /topography (mountain ranges or other air basin boundaries); and 5) j urisdictional boundaries (e.g., counties, air districts, pre

existing nonattainment areas, reservations), among any other information deemed relevant to establishing appropriate area designations and boundaries for the 1

- hour SO 2 NAAQS.

The March 24, 2011, memo recommended that area boundaries be defaulted to the county boundary unless additional information justifies a larger or smalle r boundary than that of the county. EPA believes it is appropriate to evaluate each potential area on a case

- by

- case basis, and to recognize that

area

- specific analyses conducted by states, tribal governments and/or EPA may support a different boundary th an a default county boundary.

In this TSD, EPA discusses its review and technical analysis of the recommendations submitted by the

state for designations of the 1

- hour SO 2 standard and any modifications from these recommendations.

Definition of important terms used in this document:

1) Designated “nonattainment” area

– an area which EPA has determined, based on a state recommendation and/or on the technical analysis included in this document, has violated the 2010 SO 2 NAAQS, based on the most recent thre e years of air quality monitoring data, or contributes to a violation in a nearby area.

2 ) Recommended nonattainment area

– an area that a s tate or tribal government has recommended to

EPA to be designated as nonattainment.3

3 ) Violating monitor

– an ambient air monitor meeting all methods, quality assurance and citing criteria and requirements whose valid design value exceeds 75 ppb, as described in Appendix T of 40 CFR part

50.

4 ) 2010 SO 2 NAAQS

- 75 ppb, national ambient air quality standard for SO 2 promulgated in 2010.

Based on the 3

- year average of the 99 th percentile of the annual distribution of daily maximum 1

- hour average concentrations

5 ) Design Value

– a statistic that describes the air quality status of a given area relative to the level of the NAAQS.4 Nonattainment Designations

Technical A nalysis for Hillsborough County Area

Introduction

This technical analysis for Hillsborough County Area identifies the partial county with a monitor that

violates the 2010 SO 2 NAAQS based on 2009

- 2011 data, and evaluates nearby counties for

contributions to SO 2 concentrations in the a rea. EPA has evaluated this county and nearby counties based on the weight of evidence of the factors recommended in the March 24, 2011, issued E PA guidance.

Figure 1 is a map of the area analyzed showing the locations and design values of air quality monitors in the area, and the counties surrounding any violating air quality monitors.

Figure 1. Hillsborough Nonattainment Area

In June 2011

, Florida Department of Environmental Protection (FDEP) Secretary Herschel T. Vinyard

Jr. recommended that a partial boundary in Hillsborough County be designated as “nonattainment” for

the 2010 SO 2 NAAQS based on monitored air quality data from 2008

- 2010. The State of Florida recommendation is for a nonattainment area boundary encompassing the area that, based upon air dispersion modeling, may be experiencing violations of the standard caused by an identified source.5

Based on EPA’ s technical analysis desc ribed below, EPA is initially designating a portion of Hillsborough County, Florida as nonattainment for the 2010 SO 2 NAAQS as part of the Hillsborough County nonattainment area, based upon currently available information. Th is county is listed above in

Table 1

. EPA is not yet prepared to designate other areas in Florida, apart from the Nassau County Area

discussed later.

Detailed Assessment

Air Quality Data

This factor considers the SO 2 air quality monitoring data, including the design values (in ppb) calculated for all air quality monitors in Hillsborough County and the surrounding area based on data for the 2009

- 2011 period.

Secretary Vinyard ’s recommend ation was based on data from a Federal Eq uivalent Method (FEM)

monitor located in the S tate (Florida Nonattainment Designation Recommendation Letter, June 13, 2011), i n accordance with 40 CFR Part 53

.

The 2011 SO 2 NAAQS design values for all monitors in the Hillsborough Area and su rrounding area are

shown in Table 2.

Table 2. Air Quality Data for Nonattainment Designations in Hillsborough County, FL

County State

Recommended

Nonattainment? Monitor Name Monitor Air Quality System ID Monitor Location SO 2 Design Value,

2009

- 2011 (ppb) Hillsborough County Yes East Bay (Gibsonton) 12

- 057

- 0109 27.856389

,

- 82.383667 103

No E.G. Simmons

Park 12

- 057

- 0081 27.740032,

- 82.465145 22

No Coast Guard

Station

– Davis

Island 12

- 057

- 1035 27.928056

- 82.454722 43

No Sydney 12

- 057

- 3002 27.965650

,

- 82.2304 15

Hillsborough County shows a violation of the 2010 SO 2 NAAQS. Therefore, some area in Hillsborough County and possibly additional areas in surrounding counties must be designated nonattainment. The violating monitor ( 12

- 057

- 0109 ) near Gibsonton is located approximately 1 kilometer to the southeast of the Mosaic Riverview phosphate fertilizer plant, a major source of SO 2 emissions. The primary emissions units at this facility are three sulfuric acid plants

. The absence of a violati ng monitor alone is not a sufficient reason to eliminate nearby counties as candidates for inclusion in a nonattainment area. Each area has been evaluated based on the weight of evidence of the five factors and other relevant

information.6

Emissions a nd Emissions

- Related Data

Evidence of SO 2 emissions sources in the vicinity of a violating monitor is an important factor for determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluated county level emissions data for SO 2 and any growth in SO 2 emitt ing activities since the date represented by those emissions data.

Emissions

EPA recognizes that there may be important new information on emissions levels for the period after 2008, and would consider more recent information if available. Florida did not provide updated emissions information, therefore EPA relied on the 2008 National Emissions Inventory (NEI) emissions data ( NEI08V 3 ).

Table 3 shows total emissions of SO 2 (given in tons per year (tpy) ) for violating and potentially contributing count ies in and around the Hillsborough nonattainment area, including sources emitting greater than 100 tpy of SO 2 according to the 2008 NEI

. The c ounty that contain s the Hillsborough

nonattainment area for the 2010 SO 2 NAAQS is shown in bold

.

Table 3. Annual SO 2 Emissions ( NEI08V 3 )

County Facility >100 tpy (EIS or State Facility ID) Facility Emissions (tpy) Total County SO 2

Emissions ( tpy )

Hillsborough County, FL TAMPA ELECTRIC

COMPANY

- Big Bend 9,615

18512 CF INDUSTRIES, INC.,

PLANT CITY PHOS 3,430

MOSAIC FERTILIZER, LLC 3,037

ENVIROFOCUS
TECHNOLOGIES, LLC 1,108

Tampa International Airport 119

Figure 2 shows the above facility locations in relation to the violating monitor.7

Figure 2: Facility Locations in the Hillsborough County Area

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 3 represent emissions levels taking into account any control strategies implemented on stationary sources in the Hillsborough County Area up to and including the year 2008. EP A has not received any additional information on emissions reductions resulting from federally enforceable controls put into place after 2008.

Meteorology (weather/transport patterns)

Evidence of source

- receptor relationships between specific emissions sources and high SO 2 values at violating monitors is another important factor in determining the appropriate contributing areas and the appropriate extent of the nonattainment area boundary. For this factor, EPA considered recent hourly

mete orological data from the National Weather Service (NWS) site neares t to the violating monitor to
determine which wind vectors were associated with 1

- hour SO 2 exceedances. For the Hillsborough County Area

, the meteorological data used in this analysis is f or 2009

- 2011 from the Tampa International Airport (ID # 722110

- 12842). Figure 2 shows a map of the SO 2 monitor location, meteorological data location, and the major emissions sources in the area. The Tampa International8

Airport is approximately 19 k ilome ter west of the violating monitor. The primary SO 2 emissions source

is the Mosa i c Riverview facility, which is located less than one k ilometer from the violating monitor.

Figure 3 shows a wind rose of the hours exceeding the 1

- hr SO 2 NAAQS (75 ppb) at the violating monitor. The wind rose was developed using wind data from the Tampa International Airport.

Figure 3 shows that the majority of the exceeding hours have winds blowing from the northwest with moderate to high wind speeds. As can be seen in Figure 2, the Mosaic Riverview facility is located less than 1 km to the northwest of the monitor. No other major sources are located near the violating monitor in the northwest direction. Therefore, the Mosa i c Riverview facility is likely the major

contributor to the monitor’s design value

.

FDEP performed an in

- depth analysis of wind direction data to identify the wind dir ections associated

with elevated SO 2 monitored concentrations. This information is based on “on

- site” wind data collected

Figure 3 . Wind Rose of 2009

- 2011 hours exceeding the 1

- hr

SO 2 NAAQS at the violating monitor.9

at the violating SO 2 monitor location and is provided in the “Meteorology” section of Appendix A of

this TSD . The result of this ana lysis agrees with EPA’s analysis and indicates that winds blow from the northwest during times of high SO 2 concentrations recorded at the violating monitor. This analysis

shows that the Mos ai c Riverview Facility is upwind of the monitor and is the most li kely contributor to

the monitor’s design value . This hypothesis was further evaluated by the State using dispersion modeling , although we are not at this time prepared to rely upon such modeling for this initial designation based on monitoring data . See the discussion in the “Modeling Analysis” section for further information about the modeling.

Geography/Topography (mountain ranges or other air basin boundaries)

The Hillsborough County Area does not have any geographical or topographical barriers sign ificantly limiting air

- pollution transport within its air shed. Therefore, this factor did not play a significant role in determining the nonattainment boundary.

Jurisdictional Boundaries

O nce EPA identified the general areas that the Agency anticipated would be included in the nonattainment area, EPA then consider ed existing jurisdictional boundaries for the purposes of providing a clearly defined legal boundary and to help identify the areas appropriate for carrying out the air quality planning and enforcement functions for nonattainment areas. With regard to the 2010 SO 2 NAAQS, EPA believes that the appropriate j urisdictional boundaries to be considered to include counties, air districts, pre

- existing nonat tainment areas, reservations, among any other information deemed relevant to establishing appropriate area designations and boundaries for the 1

- hour SO 2 NAAQS.

No area in Hillsborough County has been or is currently nonattainment for a prior SO 2 NAAQS, s o EPA had no boundary related to a previous nonattainment designat ion to consider for this area. Additionally, this area does not include Indian Country. Therefore, this factor did not play a significant role in determining the nonattainment boundary.

M odeling Analysis for Nonattainment Area Boundaries

The violating monitor is located within Hillsborough County, roughly in the center of the county

, approximately one kilometer to the southeast of the Mosaic Riverview phosphate fertilizer plant

. The

viol ating area associated with the primary source of SO 2 at this monitor is well within the county boundary. The State’s recommended nonattainment boundary encompasses this violating area as informed by air dispersion modeling. Although EPA is not prepared at this time to rely upon modeling for the initial nonattainment designations based on monitoring, we note that the State’s modeling

- based boundary recommendation is consistent with the boundary supported by the wind rose ana lysis

discussed above. See Appendix A of this document for modeling results for nonattainment area

boundaries. FDEP used air dispersion modeling to help delineate the boundary of the recommended nonattainment area. In completing this modeling, the Depar tment generally followed the guidance provided in the March 24, 2011, EPA memorandum, “Area Designations for the 2010 Revised Primary Sulfur Dioxide National Ambient Air Quality Standards.”10

Specifically, t he State’s recommendation letter provides modeling results to inform a nonattainment area boundary for this area. The AERMOD model results were used to determine the areal extent with which the Mosaic Riverview facility would be potentially violating the standard. The recommended nonattainment area encompasses the receptors having modeled violations of the ambient standard associated with the Mosaic Riverview facility (see Figure 4 ). Florida used its model results in an exacting manner to describe the re commended nonattainment boundaries. The nonattainment area is defined as the area where the model predicts that the SO 2 concentration (using the five

- year average of

the 4 th high value as the metric) is greater than the ambient SO 2 standard. A polygon wi th six vertices is used to define the areal extent of the nonattainment area ( s ee the discussion and figure below ).

Figure 4 . Aerial photo with nonattainment area boundary.

As indicated above, t he June 13, 2011, Florida submittal recommends a nonattainment area boundary encompassing the area that, based upon air dispersion modeling, is experiencing violations of the SO 2 standard caused by the identified source. The State’s recommended nonattainment boundary is described by a polygon encompassi ng the predicted area having a design value greater than the 1

- hour

ambient SO 2 standard of 75 ppb (see Figure 4 ). The following aerial photo below shows the bounds of the area having modeled concentrations greater than the ambient air quality standard. The annotated polygon (white line) outlines the area recommended for nonattainment classification. The red shaded area outlines the modeled area greater than the ambient standard. T he whited

- out area describes the property boundary of the Mosaic Rivervie w facility, with buildings and structures in blue. The A rea includes the location of the violating monitor. In summary, t he State’s recommendation letter provides11

the following vertices of the polygon using Universal Transverse Mercator (UTM) coordinates in UTM zone 17 with datum NAD83 (see Table 4) :

Table 4 . Unive rsal Transverse Mercator (UTM) C oordinates

Vertices UTM Easting (m) UTM Northing (m)

1 358581 3076066

2 355673 3079275

3 360300 3086380

4 366850 3086692

5 368364 3083760

6 365708 3079121

Other Relevant Information

EPA did not receive additional information relevant to establishing a nonattainm ent area boundary for

this A rea.

Conclusion

After considering the factors described above, EPA find s that it is appropriate to agree with the State of Florida’s partial boundary recommendation for the Hillsborough County Nonattainment Area . EPA’s conclusion is premised on that fact that the air quality monitor in Hillsborough County shows a violation

of the 2010 SO 2 NAAQS, based on 2009

- 2011 air quality data. Additionally, the boundary captures the violating monitor, the source contributing to the violation, and e ncompass es the appropriate initial area that does not meet (or that contributes to ambient air quality in a nearby are a that does not meet) the

2010 SO 2 NAAQS. Areas and sources that we are not yet prepared to conclude are contributing to the monitored violation are not included in this initial nonattainment area. In a subsequent round of designations we will further ad dress such areas and sources and make final designations decisions for areas that are not currently included in the nonattainment area designation addressed in this TSD.

Technical analysis for Nassau County

Introduction

This technical analysis for Na ssau County identifies the partial county with a monitor that violates the

2010 SO 2 NAAQS based on 2009

- 2011 data, and evaluates nearby counties for contributions to SO 2 concentrations in the area. EPA has evaluated this county and nearby counties based on the weight of evidence of the factors recommended in the March 24, 2011, issued EPA guidance.

Figure 5 is a map of the area analyzed showing the locations and design values of air quality monitors in the area, and the counties surrounding any violating air quality monitors.12

Figure 5. Nassau Nonattainment Area

In June 2011

, FDEP Secretary Herschel T. Vinyard Jr . recommended that most of the S tate, as a whole, be designated “unclassifiable” or “unclassifiable/attainment” for the 75 ppb 1

- hour SO 2 standard. This was intended to include the area surrounding the monitoring site in Nassau County. The State submitted a revised recommendation letter on November 28, 2011. In that letter, FDEP recommended that a portion of Nassau County also be designated “nonattainment.” The State of Florida recommendation is for a nonattainment area boundary encompassing the area that, based upon air dispersion modeling, may be exp eriencing violations of the standard caused by the identified source.

Based on EPA ’ s technical analysis described below, EPA is designating a p ortion of Nassau County,

Florida as nonattainment for the 2010 SO 2 NAAQS as part of the Nassau County nonattainment area, based upon currently available information. Th is county is listed above in Table 1

. EPA is not prepared to designate other areas in Florida, apart from the Hillsborough County Area discussed previously.

Detailed Assessment

Air Quali ty Data

This factor considers the SO 2 air quality monitoring data, including the design values (in ppb) calculated for all air quality monitors in Nassau County and the surrounding area based on data for the 2009

- 2011 period.13

Florida’s recommendation was based o n data from a FEM monitor located in the S tate (Florida Nonattainment Designation Recommendation Letter, November 28, 2011), i n accordance with 40 CFR

Part 53

.

The 2011 SO 2 NAAQS design values for all monitors in the Nassau County and surround ing area are

shown in Table 5

.

Table 5 . Air Quality Data for Nonattainment Designations in Nassau County, Florida

County State

Recommended

Nonattainment? Monitor Name Monitor Air Quality System ID Monitor Location SO 2 Design Value,

2009

- 2011 (ppb) Nassau County,

FL Y es FBHWWTP 12

- 089

- 0005 30.3583,

- 81.4633 129

Nassau County shows a violation of the 2010 SO 2 NAAQS. T herefore, some area in this county and possibly additional areas in surrounding counties must be designated nonattainment. The absence of a violating monitor alone is not a sufficient reason to eliminate nearby counties as candidates for inclusion in a nonattainment area. Each area has been evaluated based on the weight of evidence of the five

factors and other relevant informati on

.

The violating monitor ( 12

- 089

- 0005) in Fernandina Beach is located less than one k ilo m eter to the southeast of the Rayonier Performance Fibers plant, a major source of SO 2

. No other SO 2 monitors in

the northeast Florida area have recorded violations of the ambient standard.

Emissions and Emissions

- Related Data

Evidence of SO 2 emissions sources in the vicinity of a violating monitor is an important factor for determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluated county level emissions data for SO 2 and any growth in SO 2 emitt ing activities since the date represented by those emissions data.

Emissions

EPA recognizes that there may be important new information on emissions levels for the period after 2008, and would consider more rece nt information if available. Florida did not provide updated emissions information, therefore EPA relied on the 2008 NEI emissions data ( NEI08 V3 ).

Table 6 shows total emissions of SO 2 (given in tpy ) for violating and potentially contrib uting counties in and around Nassau County , including sour ces emitting greater than 100 tpy of SO 2 according to the 2008 NEI. The County that contain s all or part of the Nassau County nonattainment area for the 2010

SO 2 NAAQS is shown in bold

.14

Table 6 . Annual SO 2 Emissions ( NEI08V3 )

County Facility > 100 tpy

(EIS or State Facility ID) Facility Emissions (tpy) Total County SO 2 Emissions ( tpy )

Nassau County, FL SMURFIT

- STONE

CONTAINER

CORPORATION 4,340

5,288 RAYONIER

PERFORMANCE FIBERS

LLC 887

Figure 6 : Facility Locations in the Nassau County Area

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 6 represent emissions levels taking into account any control strategies implemented on stationary sources in Nassau County up to and including the year 2008. EPA has not received any additional information on emissions reductions resulting from federally e nforceable controls put into place after 2008.15

Meteorology (weather/transport patterns)

Evidence of source

- receptor relationships between specific emissions sources and high SO 2 values at violating monitors is another important factor in determining the appropriate contributing areas and the appropriate extent of the nonattainment area boundary. For this factor, EPA considered recent hourly

mete orological data from the NWS site neares t to the violating monitor to determine which wind vectors

were associa ted with 1

- hour SO 2 exceedances. For the Nassau Area

, the meteorological data used in this analysis is for 2009

- 2011 from the Fernandina Beach site (ID # 997347

- 99999). Figure 6 shows a map

of the SO 2 monitor location, meteorological data location, and t he major emissions sources in the area.

The Fernandina Beach site is less that one k ilometer northeast of the violating monitor. The primary SO 2 emissions sources nearby are the Rayonier Performance Fibers facility, located approximately one k ilometer northwest from the violating monitor, and the Smurfit

- Stone Container Corporation facility, located approximately 2.5 k ilometer north

- northeast from the violating monitor.

Figure 7 shows a wind rose of the hours exceeding the 1

- hr SO 2 NAAQS (75 ppb) at the violating monitor. The wind rose was developed using wind data from the Fernandina Beach site.

Figure 7 . Wind Rose of 2009

- 2011 hours exceeding the 1

- hr

SO 2 NAAQS at the vio lating monitor.16

Figure 7 shows that the majority of the exceeding hours have winds blowing from the west

- northwest direction with low to moderate wind speeds. As can be seen in Figure 6, the Rayonier Performance Fibers facility is located approximately 1 k ilometer northwest of the monitor. No other major sources are located near the violating monitor in the west

- northwest direction. Therefore, the Rayonier Performance Fibers facility is likely the major contributor to the violating monitor’s design value

.

FDEP performed an in

- depth analysis o f wind direction data to identify the wind directions associated

with elevated SO 2 monitored concentrations. This information is provided in the “Meteorology” section of Appendix B of this TSD . The result s of this analysis agree with EPA’s analysis above which indicates that winds blow from the northwest during times of high SO 2 concentrations at the violating monitor. This analysis shows that the Rayonier Facility is upwind of the monitor and is the most likely

contributor to the monitor’s design value

. Although we are not yet prepared to rely upon modeling for these initial designations based on monitored violations, t his hypothesis was further evaluated by the State using dispersion modeling. See the discussion in the “Modeling Analysis” section for further information about the modeling.

Geography/Topography (mountain ranges or other air basin boundaries)

Nassau County does not have any geographical or topographical barriers significantly limiting air

pollution transport within its air shed. Therefore, this factor did not play a significant role in determining the nonattainment boundary.

Jurisdictional Boundaries

O nce EPA identified the general areas that the Agency anticipated would be included in the nonattainment area, EPA then consider e d existing jurisdictional boundaries for the purposes of providing a clearly defined legal boundary and to help identify the areas appropriate for carrying out the air quality planning and enforcement functions for nonattainment areas. With regard to the 2010 SO 2 NAAQS, EPA has determined that the appropriate j urisdictional boundaries to be considered to include counties, air districts, pre

- existing nonattainment areas, reservations, among any other information deemed relevant to establishing appropriate a rea designations and boundaries for the 1

- hour SO 2 NAAQS.

No area in Nassau County has been or is currently designated nonattainment for a prior SO 2 NAAQS, so EPA had no boundary related to a previous nonattainment designatio n to consider for this area. Additionally, this area does not include Indian Country. Therefore, this factor did not play a significant role in determining the nonattainment boundary.

Modeling Analysis for Nonattainment Area Boundaries

The violating monitor is located in the northeastern part of Nassau County

, less than 1 kilometer to the southeast of the Rayonier Performance Fibers plant . The violating area associated with the primary

source of SO 2 at this monitor is well within the county boundary. The State’s recommended

no nattainment boundary encompasses this violating monitor as informed by air dispersion modeling. Although EPA is not prepared at this time to rely upon modeling for the initial nonattainment designations based on monitoring, we note that the State’s modelin g

- based boundary recommendation is17

consistent with the boundary supported by the wind rose analysis discussed above. See Appendix B of this document for modeling results for nonattainment area boundaries. FDEP used air dispersion modeling to help delinea te the boundary of the recommended nonattainment area. In completing this modeling, the Department generally followed the guidance provided in the March 24, 2011, EPA memorandum, “Area Designations for the 2010 Revised Primary Sulfur Dioxide National Ambi ent Air Quality Standards.”

Specifically, the State’s updated recommendation letter dated November 28, 2011, (in Appendix B) provides modeling results to inform a nonattainment area boundary for this area. The AERMOD model

results were used to determine the areal extent with which the Rayonier facility would be potentially violating the standard. The recommended nonattainm ent area encompasses the receptors having modeled violations of the ambient standard associated with the Rayonier facility . Florida used its model results in an exacting manner to describe the recommended nonattainment boundaries. The

nonattainment area is defined as the area where the model predicts that the SO 2 concentration (using the

five

- year average of the 4 th high value as the metric) is greater than the ambient SO 2 standard. A

circular area is used to define the areal extent of the nonattainment area ( s ee the discussion and figure below).

Figure 8 . Aerial photo with nonattainment area boundary.

As indicated above, the November 28, 2011, Florida submittal recommends a nonattainment area boundary encompassing the area that, based upon air dispersion modeling, is experiencing violations of

the SO 2 standard caused by the identified source. The State’s recommended nona ttainment boundary is centered on the violating monitor and encompasses the area having a modeled violation of the ambient standard associated with the Rayonier facility. The State’s recommendation letter ( in Appendix B ) provides a circular boundary of th e area recommended for nonattainment classification, with the center being the location of the violating ambient monitor and the radius being 2.4 kilometer s

. Figure 8

illustrates an aerial photo of the modeled nonattainment area boundary.18

Other Relevant Information

EPA did not receive additional information relevant to establishing a nonattainment area boundary for

this A rea.

Conclusion

After considering the factors described above, EPA find s that it is appropriate to agree with the State of Florida’s partial boundary recommendation for the Nassau County Nonattainment Area . EPA’s conclusion is premised on that fact that the air quality monitor in Nassau County shows a violation of

the 2010 SO 2 NAAQS, based on 2009

- 2011 air quality data. Additionally, the boundary captures the violating monitor, the source contributing to the violation, and e ncompass es the appropriate initial area that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the

2010 SO 2 NAAQS. Areas and sources that we are not yet prepared to conclude are contributing to the monitored violation are not included in this initial nonattainment area. In a subsequent round of designations we will further address such a reas and sources and make final designations decisions for areas that are not currently included in the nonattainment area designation addressed in this TSD.19 Appendix A

Modeling Results Used to Inform Florida’s Recommended Area Boundaries Hillsborough County Area Modeling Discussion (Appendix 2 of the 6/13/11 submittal)

Meteorology A review of the monitoring data in relation to the wind direction at the time of maximum concentrations

revealed that all recorded occurrences of SO 2 above the level of the standard (75 ppb) were associated with winds coming from the Mosaic Riverview facility. The following aerial photo shows the direction of the Mosaic Riverview facility from the SO 2 monitor. The distance from the primary SO 2 source s (three sulfuric acid plants) to the monitor is 1 kilometer, with the direction of the entire facility ranging

from 295 o to 350 o

. The following tables list each of the hours in which a concentration was greater than

the ambient SO 2 standard (75 ppb) alon g with its associated wind direction. The wind direction data come from the wind instrument located at the monitoring site (wind data from the nearby Simmons Park monitoring site are substituted when data at the Gibsonton site are missing). The tables sh ow that for some hours of high SO 2 concentration the wind appears to be coming from a direction of about 56 o

. There are no SO 2 sources from that direction, so the department reviewed the wind direction data for regional consistency. A review of these data shows that winds measured at other wind instruments in the area during these hours are consistent with a wind flow from the Mosaic Riverview facility. The wind direction data from the nearby Simmons Park site, located to the south of the Gibsonton monitor , are shown as a truer representation of the winds during these hours. Florida has not identified the reason why the Gibsonton wind instrument displays this behavior; however, it appears to be confined to the period from November 19, 2009, through Februar y 17, 2010. Both before and after this period, SO 2 concentrations remain near zero when the winds are out of this direction.20

SO 2 Concentration and Associated Wind Direction (2008) (for hours greater than 75 ppb)21

SO 2 Concentration and A ssociated Wind Direction (2009) (for hours greater than 75 ppb)22

SO 2 Concentration and A ssociated Wind Direction (2010) (for hours greater than 75 ppb)

Air Dispersion Modeling

Florida used air dispersion modeling to help delineate the boundary of the State’s recommended

nonattainment area. In completing this modeling, Florida generally followed the guidance provided in the March 24, 2011, EPA memorandum, “Area Designations for the 201 0 Revised Primary Sulfur Dioxide National Ambient Air Quality Standards.”

a) Model Selection

– The department used the AERMOD modeling system.

a. AERMOD ver11103

b. AERMAP ver11103

c. AERMET ver06341

d. AERSURFACE ver08009

b) Modeling Domain

– The focus of the nonattainment designation is on the monitor having the

violation. As noted above, wind data at the monitoring site indicate that all of the monitored high concentrations (greater than the standard of 75 ppb) occur within a small wind direction sector that implicates the nearby Mosaic Riverview phosphate processing facility. Modeling of this source alone

suggests that the predicated concentrations at the location of the monitor are almost completely explained by this single source. As a result, the modeling domain is centered on the Mosaic Riverview facility, which is located only 1000 meters from the monitoring location and the domain extends to a 15 by 15 kilometer area around this facility.23

c) Determining the Sources to Model

– Because the M osaic Riverside facility is the overwhelming

source of the monitored violation, it is the only source that Florida modeled for the purpose of informing

the extent of the recommended nonattainment area. Florida recognizes that other SO 2 sources in the

mult i

- county area could interact with the Mosaic facility for certain wind directions. Florida believes for the purpose of simply determining the initial area of nonattainment encompassing the violating monitor,

it is sufficient to focus on the Mosaic Riversi de facility.

d) Receptor Grid

– The receptor grid follows EPA ’s March 2011 guidance: a nested grid with 50 meter spacing within one kilometer of the source, 100 meter spacing from one to two kilometers, 250 meters from two to ten kilometers, and 500 kil ometers outside of ten kilometers.

e) Source Inputs

– Maximum allowable short

- term limits on SO 2 emissions or potential

- to

- emit levels

were used for all sources. Stack and emission information were obtained from the Florida’s Air Resource Management Syste m, Title V operating permits, and previous air construction permit applications. These data were reviewed by Mosaic, resulting in changes in refinement of the inputs related to geographic location of buildings and stacks. Where stack heights are less tha n good engineering practices ( GEP ) , building downwash effects are included. No stacks at this facility exceed GEP limits. The ground surface characteristic of the area is rural as determined through land

- use data consistent with the guidance.

f) Meteorological Data

– Five years (2005

- 2009) of meteorological data from the National Weather Service site at Tampa International Airport were used in this analysis. These data were processed through AERMET version 06341. The Tampa airport is located appro ximately 20 k ilometer from the Mosaic facility, also along Tampa Bay. These data are deemed representative of the area in which

Mosaic Riverview is located.

g) Background Concentration

– The background concentration at the Gibsonton monitor was determined based on the 99th percentile maximum daily 1

- hour value on hours that were not impacted by the Mosaic Riverview facility. A 90

- degree sector of wind directions centered on the Mosaic facility was excluded from the calculation to avoid double counting. T he 99 th percentile of the remaining

concentrations associated with winds not from the direction of the Mosaic facility was calculated for each year and averaged. Based on this calculation, the background concentration is 25.8 ppb.

Modeling Results

The AE RMOD model results were used to determine the areal extent with which this facility would be potentially violating the standard. The State’s recommended nonattainment area encompasses the

receptors having modeled violations of the ambient standard associa ted with the Mosaic Riverview facility. A review of the modeled impact at the location of the monitor provides an indication of the general performance of the model in describing the SO 2 concentrations. The table below compares the

model results with tho se at the monitor.24

Year Modeled

Maximum at

Monitor Location (ppb) Actual 1 st High

Maximum 1 hour

value at Monitor (ppb) Modeled 4 th High at

Monitor Location (ppb) Actual 4 th High

(99 th Percentile) at Monitor (ppb)

2005 163.0 151 133.5 135

2006 166.7 130 130.5 96

2007 163.3 143 137.6 126

2008 187.3 189 140.1 123

2009 153.7 136 130.1 104

These results indicate that the model is performing very well in replicating the SO 2 concentration at the monitoring location, and that the Mosaic Riverview facility explains virtually all of the elevated

concentrations that occur at this monitor. The design value concentrations in the area due to the Mosaic Riverview facility show that there are potentially higher concentrations in other locations.

The maximum modeled design values associated with the Mosaic facility for 2005

- 2009 are as follows.

Year Date (MMDDHH) 4 th High Concentration (ppb)

2005 010411 506.7

2006 031211 494.8

2007 120811 486.7

2008 090110 462.6

2009 022617 442.1

5

- Year Average 478.5

It should be noted that the location of the design value concentration is on the Mosaic plant property. Because the model performance is very good, the department has used the model results in an exacting

manner to describe the State’s recommended nonattainment boundaries

. The State’s recommended

nonattainment area is defined as the area where the model predicts that the SO 2 concentration (using the

five

- year average of the 4 th high value as the metric) is greater than the ambient SO 2 standard. A polygon with six vertices is used to define the areal extent of the nonattainment area. The following aerial photo below shows the bounds of the area having modeled concentrations greater than the ambient air quality standard. The annotated polygon (white line) outlines the State’s recommended area for

nonattainment classification. The red shaded area outlines the modeled area greater than the ambient

standard. T he whited

- out area describes the property boundary of the Mosaic Riverview faci lity, with buildings and structures in blue.2526 Appendix B

Nassau County Area Modeling Discussion (Appendix of the 11/28/11 submittal)

Meteorology A review of the monitoring data in relation to the wind direction at the time of maximum concentrations

revealed that all monitored occurrences of SO 2 above the level of the standard (75 ppb) were associated with winds coming from the Rayonier facility. T he following aerial photo shows the direction of the Rayonier facility from the SO 2 monitor. The distance from the facility t o the monitor is 1 kilometer, with the direction of the entire facility ranging from 290 o to 320 o

. The following tables list all o f the hours in which a concentration was greater than the ambient SO 2 standard (75 ppb) along with its associated

wind direction. The wind direction data come from the wind instrument located at the monitoring site.

When the winds come from the direction of the nearby Rock Tenn pulp mill, the monitor typically registers single digit SO 2 concentrations with highest value in the upper 30’s ppb. It is clear that the Rayonier facility is contributing to the violation

.27

SO 2 Concentration and Associated Wind Direction (2008) (for hours greater than 75 ppb)

SO 2 Concentration and Associated Wind Direction (2009) (for hours greater than 75 ppb)28

SO 2 Concentration and Associated Wind Direction (2010) (for hours greater than 75 ppb)29

Air Dispersion Modeling

Florida used air dispersion modeling to help delineate the boundary of the State’s recommended

nonattainment area. In completing this modeling, Florida generally followed the guidance provided in the March 24, 2011, EPA memorandum, “Area Designations for the 2010 Revised Primary Sulfur Dioxide National Ambient Air Quality Standards.”

a) Model Selection

– The departme nt used the AERMOD modeling system.

a. AERMOD ver11103

b. AERMAP ver11103

c. AERMET ver11059

d. AERMINUTE ver11059

e. AERSURFACE ver08009

b) Modeling Domain

– The focus of the nonattainment designation is on the monitor having the

violation. As note d above, wind data at the monitoring site indicate that all of the monitored high concentrations (greater than the standard of 75 ppb) occur within a small wind direction sector that implicates the nearby Rayonier facility. As a result, the modeling domai n is centered on the Rayonier facility, which is located only 1 kilometer from the monitoring location and the domain extends to a 10 by 10 kilometer area around this facility.

c) Determining the Sources to Model

– Because the Rayonier facility is the ov erwhelming source for the violation, this is the only source modeled for the purpose of determining the extent of the initial

nonattainment area.

d) Receptor Grid

– The receptor grid used follows the March 2011 EPA guidance. A nested grid with

50 meter spacing within one kilometer of the source, 100 meter spacing from one to two kilometers, and

250 meters from two to ten kilometers.

e) Source Inputs

– Maximum allowable short

- term limits on SO 2 emissions or potential to emit levels were used for all sources. Stack and emission information were obtained from the department’s Air Resource Management System, Title V operating permit, and previous air construction permit applications. These data we re reviewed by Rayonier to verify the correct geographic location of buildings and stacks. Where stack heights are less than GEP, building downwash effects are included. No stacks at this facility exceed GEP limits. The Rayonier facility is rural as dete rmined through land

use data consistent with the guidance.

f) Meteorological Data

– Five years (2006

- 2010) of meteorological data from the NWS site at Jacksonville International Airport were used in this analysis. These data were processed through

AERME T version 11059, using 1

- minute data from the same site processed through AERMINUTE

version 11059. The Jacksonville airport is located approximately 28.5 kilometers to the south of the violating monitor.

g) Background concentration

– The background conc entration at the Fernandina Beach monitor was determined based on the 99th percentile maximum daily 1

- hour value on hours that were not impacted by the Rayonier facility. A 90

- degree sector of wind directions centered on the Rayonier facility was30

excluded from the calculation to avoid contribution from the Rayonier facility. The 99th percentile of the remaining concentrations associated with winds not from the direction of the Rayonier facility were calculated for each year and averaged. Based on this ca lculation, the background concentration is 26.0 ppb.

Modeling Results The AERMOD model results were used to determine the areal extent to which this facility would be potentially violating the standard. The State’s recommended nonattainment area is cen tered on the violating monitor and encompasses the area having a modeled violation of the ambient standard associated with the Rayonier facility.

The maximum modeled design values associated with the Rayonier facility for the 2006

– 2010 are as

follows.

Year Date (MMDDHH) 4 th High Concentration (ppb)

200 6 082909 230.7

2007 081709 267.0

2008 072214 274.7

2009 072812 276.6

2010 071812 284.5

5

- Year Average 266.7

The aerial photo below shows the bounds of the area having modeled concentrations greater than the ambient air quality standard. The red annotation circle outlines the area recommended for nonattainment classification, with the center being the location of the violating ambient monitor and the radius being 2.4 kilometers. Inside the sh aded pink area outlines the modeled area greater than the

ambient standard.