1 

### BATON ROUGE, LOUISIANA

Final Area Designations f or the

20 08 Ozone National Ambient Air Q uality Standard s

Table 1 below identifies parishes in Louisiana that EPA is designating as no n attain ment for the 2008

o zone national ambient air quality standard s (20 08 ozone NAAQS) 1 as part of the Baton Rouge,

Louisiana nonattainment area

. In accordance with section 107(d) of the Clean Air Act, EPA must designate a n area “nonattainment” if it is violating the 2008 ozone NAAQS or if it is contributing to a

violation of the 2008 ozone NAAQS in a nearby area

. EPA is designating one nonattainment area within the state of Louisiana. The technical analysi s supporting the designation and boundaries fo r this

nonattainment area is prov ided below. This technical analysis includes evaluation of information submitted by the State of Louisiana and comments received from the public. The formal responses to

comments received are provided in the 2008 ozone designation response to comments docu ment which

can be found in electronic docket EPA

- HQ

- OAR

- 2008

- 0476 (www.regulations.gov)

.

Table 1. Areas in Louisiana Included in the Baton Rouge, LA Ozone Nonattainment Area

Area Name Louisiana’s Recommended

Nonattainment Parishes EPA’s Designated

Nonattainment Parishes

Baton Rouge, LA East Baton Rouge Ascension East Baton Rouge

Iberville Livingston West Baton Rouge

EPA is designating as “ unclassifiable/ attainment ” for the 2008 ozone NAAQS the remaining parishes in

Louisiana that are not listed in the table above

.

The analysis below provides the basis for the Baton Rouge, Louisiana nonattainment area boundar ies

. It relies on our analysis of monitoring data that show violations of the 20 08 o zone NAAQS

, which is based

on certified air quality monitoring data from 2008

- 2010

, and on an evaluat ion of whether nearby areas are contributing to such violations

. EPA has evaluated contribution s from nearby areas based on a weight of evidence analysis that consider s the factors identified below

. EPA issued guidance on December 4, 2008 that identified these factors as ones EPA should consider in determining

nonattainment area boundaries and recommend ed that s tates consider these factors in making their designations recommendations to EPA

. 2

1. A ir quality data ( including the design value calculated for each FRM or FEM 3 monitor in the

area ) ;

1 The primary 8

- hour ozone standard, set to protect human health, was revised on March 27, 2008 (73 FR 16436) from 0.08 parts per million (ppm) to 0.075 ppm. The secondary ozone standard, set to protect human welfare and the environment, was revised to be consistent with the primary ozone standard.

2 The December 4, 2008 guidance memorandum “Area Designations for the 2008 Revised Ozone National Ambient Air Quality Standards” refers to nine factors

. In this tech nical support document we have grouped the emissions

- related factors together under the heading of “Emissions and Emissions

- Related Data

, ” which results in five categories of factors.

3 FRM refers to Federal Reference Method, and FEM refers to Federal Equi valent Method. FRM monitors utilize a chemi

luminescent technique to measure ozone, while many FEM monitors use a technique involving ultraviolet photometry. FEM methods began t o be developed in the late 1970 s and early1980s and are now the most widely uti lized methods for2 2. Emissions and emissions

- related data ( including location of sources and population , amount of

emissions and emissions controls , and urban growth patterns) ; 3. M eteorology (weather/transport patterns) ; 4. G eography and topography (mountain ranges or other basin boundaries) ; 5. J urisdictional boundaries (e.g., parishes , air districts, existing nonattainment areas, Indian

country , metropolitan planning organizations (MPOs))

Ground

- level ozone generally is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NO x ) and volatile organic compounds (VOC) in the presence of sunlight

. 4

NO x and VOC emissions from a broad range of sources over a wide area typically contribute to

violations of the ozone standard s

. Accordingly, EPA chose to examine the five factors with respect to

the larger of the Combined Statistical Area (CSA) or Core Based Statistical Area (CBSA) associated with the violating monitor(s)

. 5 All data and information used by EPA in this evaluation are the latest available to EPA and/or provided to EPA by states or tribes.

In EPA’s designations guidance for the 2008 ozone NAAQS

, EPA recommend ed examining

CSA/C B SA s because certain factors used to establish CSAs and C B SAs are similar to the factors EPA is using in this technical analysis to determine if a nearby area is contributing to a violation of the 20 08

o zone NAAQS

. Congress required a similar approach in 1990 for areas classified as serious or above for

the 1

- hour ozone standard

, and EPA used the same basic approach in the designation process for the

1997 o zone NAAQS

. Where a violating monitor is not located in a CSA or C B S A, EPA ’s September 4, 2008, guidance recommend ed using the boundary of the county or parish containing the violating monitor as the starting point for considering the nonattainment area’s boundary

.

Technical Analysis for Baton Rouge , Louisiana

Figure 1 is a map of the designated Baton Rouge nonattainment area

. The map provides other relevant

information

, including the locations and design values of air quality monitors

, parish and other jurisdictional boundaries, relevant statistical area boundaries

, the nonattainment area boundary for the 1997 ozone NAAQS

, and major transportation arteries

.

monitoring ozone levels. Refer to 40 CFR Part 53 for a more detailed description of FEM and FRM methods. http://www.epa.gov/ttnamti1/fi les/ambient/criteria/reference

- equivalent

- methods

- list.pdf

4 Peak ozone concentrations generally occur downwind of source areas on relatively sunny days with high temperatures and relatively low wind speeds.

5 Lists of CBSAs and CSAs and their geographic components are provided at www.census.gov/population/www/metroareas/metrodef.html

. The lists are periodically updated by the Office of Management and Budget

. EPA used the most rece nt update, based on 2008 population estimates, issued on December 1, 2009 (OMB

Bulletin No. 10

- 02).3 Figure 1: Designated Baton Rouge nonattainment area.

For purposes of the 1997 8

- hour ozone NAAQS, this area was designated nonattainment

. The boundary

for the nonattainment area for the 1997 o zone NAAQS was a five parish area that included the entire parishes of Ascension , East Baton Rouge, Iberville, Livingston, and West Baton Rouge

.

In March 2009

, 6 Lou isi ana recommended that eleven parishes throughout the state, including East Baton Rouge P arish

, be designated as nonattainment for the 2008 ozone NAAQS b ased on air quality data

from 2006

- 2008

. In January 2011

, 7 Louisiana provided a revised recommendation that only East Baton Rouge Parish be designated nonattainment. This revised recommendation was based on air quality data

from 2008

- 2010

, which was obtained from FEM /FRM monitors sited and operated in accordance with

40 CFR Part 58

.

After considering thes e recommendation s and b ased on EPA's technical analysis described below, EPA is designating five parishes in Louisiana (identified in T able 1 above ) a s “ nonattainment ” for the 20 08

o zone NAAQS as part of the Baton Rouge nonattainment area

.

6 Initial 2008 ozone NAAQS designation recommendation letter from Secretary Leggett to then Acting Regional Administrator Larry Starfield, dated March 12, 2 009.

7 Updated ozone designation letter from Secretary Hatch to Regional Administrator Armendariz, dated January 25, 2011

.4 Factor Assessment



### Factor 1 : Air Q uality D ata

For this factor , we considered 8

- hour o zone design values (in ppm ) for air quality monitors in parishes in

the Baton Rouge

- Pierre Part CSA based on data for the 2008

- 2010 period (i.e., the 2010 design value, or DV) , which comprises the most recent years with fully

- certified air quality data for the state of

Louisiana

. A monitor’s design value is the metric or statistic that indicates whether that monitor attains a specified air quality standard

. The 2008 o zone NAAQS are met at a monitor when the annual f ourth

highest daily maximum 8

- hour average concentration, averaged over 3 years

, is 0.075 ppm or less

. A design value is only valid if minimum data completeness criteria are met ( S ee 40 CFR part 50 App endix

P )

. Where several monitors are located in a parish (or a designated nonattainment area or maintenance

area ), the design value for the parish or area is determined by the monitor with the highest individual design value

.

The 2010 design value s for the o zone NAAQS for parishes in Baton Rouge and the nearby surrounding

area are shown in Table 2

.

Table 2

. Air Quality Data

.

Parish State Recommended

Nonattainment? 2008

- 2010 D esign V alue ( ppm ) Ascension, LA No 0.0 75 Assumption, LA No

-- East Baton Rouge, LA Yes 0.0 78 East Feliciano, LA No

-- Iberville, LA No 0.0 73 Livingston, LA No 0.0 75 Pointe Coupee, LA No 0.0 75 St. Helena, LA No

-- West Baton Rouge, LA No 0.0 71 West Feliciano, LA No

--

Ambient monitor ing in East Baton Rouge Parish indicate s a violation of the 2008 o zone NAAQS ;

t herefore this parish is inclu ded in the nonattainment area

. A parish (or partial parish ) must also be designated nonattainment if it contributes to a violation in a nearby area

. E ach parish without a violating

monitor that is located near a parish with a violating monitor has been evaluated , as discussed below,

based on the five factors and other relevant information to determine whether it contributes to the nearby

violation

. EPA also notes that, in addition to the violating monitor in East Baton Rouge Parish, ambient monitors in three parishes in the Baton Rouge area, Ascension Parish, Livingston Parish, and Pointe Coupee Parish, indicate design values just under the nonattainment threshold. Assumption, East Feliciano, St. Helena, and West Feliciano parishes do not have ozone monitoring sites.



### Factor 2: Emissions and Emissions

- Related Data

EPA evaluated emissions of ozone precursors ( NO x and VOC ) and other emissions

- related data that provide information on areas contributing to measured violations of the 2008 ozone NAAQS in East Baton Rouge Parish

.5 Emissions Data

EPA evaluated parish

- level emission data for anthropogenic NO x and VOC derived from the 200 8 National Emissions Inventory (NEI), version 1.5

. This is the most recently available emissions data in

the NEI. (See http://www.epa.gov/ttn/chief/net/2008inventory.html )

. Significant emissions levels in a nearby area indicate the potential for the area to contribute to observed violations.

Table 3 shows emissions of NO x and VOC (given in tons per year or tpy ) for violating and nearby parishes that we considered for inclusion in the Baton Rouge nonattainment area

.

Table 3

. Total 2008 NO x and VOC Emissions.

Parish State Recommended

Nonattainment ? NO x (tpy) VOC (tpy)

Ascension , LA No 14,128 13, 524 Assumption, LA No 1,654 2,008 East Baton Rouge , LA Yes 21, 863 24, 473

East Feliciana , LA No 1,142 1, 631

Iberville , LA No 14, 818 10,152 Livingston , LA No 3, 087 4, 780 Pointe Coupee , LA No 15, 733 2, 560

St. Helena , LA No 1,154 1,001 West Baton Rouge , LA No 9, 268 3, 467

West Feliciana , LA No 1,107 793

Area

- wide : 83,954 64,389

Five parishes in the CSA are characterized by comparatively high emissions of anthropogenic NO x
, which exceed 9,000 tpy , and three parishes have comparatively high anthropogenic VOC emissions in excess of 10,000 tpy

. Collectively, the parishes of Ascension, East Baton Rouge, Iberville, Pointe Coupee, and West Baton Rouge contribute 90 percent of the anthropogenic NO x emissions for the ten

parish area. Similarly, Ascension, East Ba ton Rouge, and Iberville Parishes collectively contribute 75 percent of the ten

- parish area’s VOC emissions

. The relatively high emissions of ozone precursors in these parishes are a factor that EPA considered in evaluating their possible inclusion in the Baton Rouge

nonattainment area.

In our analysis of the emissions data for the area, we took note that the NO x emissions from Pointe Coupee originate primarily from a single point source facility (Big Cajun Power Plant) in the northeast

part of the parish

. If the NOx emissions from the emission uni ts at this facility are removed (12,119 tpy in 2008), the rest of anthropogenic NOx emissions sources in the parish total to 3,614 tpy in 2008

.

The remaining parishes are characterized by comparatively low anth ropogenic NO x and VOC emissions, in the range of 1,000 to 5,000 tpy

.6 Population density and degree of urbanization

EPA evaluated the population and vehicle use characteristics and trends of the area as indicators of the probable location and magnitude of non

- point source emissions

. These include ozone

- generating

emissions from on

- road and off

- road vehicles and engines, consumer products, residential fuel

combusti on, and consumer services

. Areas of dense population or commercial development are an indicator of area source and mobile source NO

x and VOC emissions that may contribute to ozone

formation that in turn contributes to nonattainment of the NAAQS in the area

. Rapid population or VMT growth (see below) in a parish on the urban perimeter signifies increasing integration with the core urban area, and indicates that it may be appropriate to include the area associated with area source and

mobile source emissions as part of the nonattainment area. Table 4 shows the population , population density, and population growth information for each of the evaluated parish es in the area.

Table 4

. Population and Growth.

Parish State

Recommended

Nonattainment? 2010 Population 2010 Population Density (1

, 000 pop/sq mi) Absolute change in population

(2000

- 2010) Population % change (2000

- 2010)

Ascension , LA No 107,215 0.35 29,937 39 Assumption , LA No 23,421 0.06 42 0

East Baton Rouge , LA Yes 440,171 0.93 27,281 7

East Feliciana

, LA No 20,267 0.04 (1,098) (5)

Iberville , LA No 33,387 0.05 72 0 Livingston , LA No 128,026 0.18 35,496 38 Pointe Coupee

, LA No 22,802 0.04 46 0

St. Helena , LA No 11,203 0.03 695 7

West Baton Rouge , LA No 23,788 0.12 2,224 10

West Feliciana

, LA No 15,625 0.04 488 3

Area

- wide : 825,905 0.18 95,183 13
Source s : U.S. Census Bureau population estimates for 20 10 as of August 4, 2011 ( http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=DEC_10_PL_GCTP L2.STO5&prodType=table )

The 2010 Census data indicates that the majority of the population of the Baton Rouge

- Pierre Part CSA

resides in the parishes of Ascension, East Baton Rouge, and Livingston; each of these parishes is characterized by population counts in excess of 100,000 peop le and population densities greater than 150 people per square mile. Although West Baton Rouge has a lower population than Ascension, East Baton Rouge, and Livingston, it does have a population density of 120 people per square mile, which is

similar to tha t of the larger parishes.

Three of the parishes, Ascension, Livingston, and West Baton Rouge, have undergone increases in population of 10 percent or more since the 2000 Census was taken. The growth in population in these three parishes accounts for almo st all the total population growth for the area.

The presence of large populations and high population density is an indicator of high area and mobile source emissions of ozone precursors that may contribute to observed violations of the 2008 ozone NAAQS in this area, which supports inclusion of these parishes in the nonattainment area. The remaining parishes are mostly rural with little urbanization.7 The attachment to this document contains Figure 2, Baton Rouge Ozone and Ozone Precursor Monitoring Network, and Figure 3, Population Density Change Percentage Between 2000 and 2010

Census for Baton Rouge Ozone and Ozone Precursor Monitoring Network, which present graphical information on population density and growt h for the Baton Rouge area

.

Traffic data

EPA evaluated the total Vehicle Miles Traveled (VMT) for each parish in the Baton Rouge area

. In

combination with the population/ population density data and the location of main transportation arteries (see above) , this information helps identify the probable location of non

- point (mobile) source emissions. A parish with high VMT is generally an integral part of an urban area and indicates the presence of motor vehicle emissions that may contribute to ozone formation that in turn contributes to

nonattainment with the NAAQS in the area

. Rapid population or VMT growth in a parish on the urban perimeter signifies increasing integration with the core urban area, and indicates that the associated area

source and m obile source emissions may be appropriate to consider as contributors to the nonattainment

area

. Table 5 shows traffic data for each parish , including the total VMT in 2008 and VMT growth for the period from 2002 to 2008

.

Table 5 . Traffic D ata (As Indicated by VMT)

.

Parish State Recommended

Nonattainment? 2008 VMT* (million miles) % Change in VMT (2002

– 2008)

Ascension , LA No 1,141 +28 Assumption , LA No 261 +54

East Baton Rouge , LA Yes 3,572 +19
East Feliciana, LA No 225

- 19
Iberville, LA No 516 +28 Livingston, L A No 1,287 +12 Pointe Coupee , LA No 289 +25

St. Helena , LA No 136 +8 West Baton Rouge, LA No 596 +102

West Feliciana , LA No 160

- 33

Area

- wide: 8,183

--- * MOBILE model VMTs are those inputs into the NEI version 1.5

.

Five of the parishes in the Baton Rouge area are characterized by comparatively high VMT

. These parishes are: Ascension, East Baton Rouge, Iberville , Livingston, and West Baton Rouge

. Collectively these five parishes account for 87 percent of the total VMT for the area

. Because motor vehicle

emissions usually contribute significantly to an urban area’s NO x emissions inventory, indicators such as high VMT and growth in VMT support inclusion of these parishes in the nonattainment area designat ion. The remaining parishes, including East Feliciana and Pointe Coupee

, are characterized by low total VMT relative to the core parishes discussed above.8 

### Factor 3 : Meteorology (weather/transport patterns)

EPA evaluate d available meteorological data to help determine how meteorological conditions, such as weather, transport patterns and stagnation conditions, would affect the fate and transport of precursor emissions contributing to ozone formation. Normally when we are developing a conceptual model understanding of the meteorology that yields ozone exceedances in an area

, we will evaluate five to ten years worth of meteorological data. R eductions were done regionall y and locally prior to 2006. To better

reflect current emission and meteor o logical conditions that yield ozone exceedances we evaluate d the

2006

- 2010 period (the time period after the reductions) for all days that had ozone exceedances at the design value monitor t o give a representative met eorological data set analysis.

We conducted an analysis of back trajectories to assess where air masses originated for the 24 hours leading up to observed ozone exceedances (greater than 0.075 ppm ) that occurred at the LSU monitor

. This monitor has consistently set the design value for the last five years in the Baton Rouge area. We

used the National Oceanic and Atmospheric Administration Hybrid Single Particle Lagrangian Integrated Trajectory Model ( HYSPLIT ) model to assess all exceedances at the design v alue monitor for the area, the LSU monitor, for the years 2006 to 2010. HYSPLIT trajectories alone do not determine inclusion or exclusion of an area with regard to ozone designations. Rather, HYSPLIT trajectories are supporting information that complements other meteorological info rmation

, as well as information concerning the other factors. For this reason, one cannot set any interpretative thresholds, such as the percentage of trajectories that must traverse an area for that area to be considered contributing. In considering wheth er a parish may contribute to monitored ozone exceedances

, we consider both the frequency of trajectories and the emissions of ozone pre cursors from a parish. HYSPLIT analysis was conducted using the available EDAS meteorological databases and run for the 24 hours preceding the

afternoon of the monitored violation

. We used a standard 100 meter start height at the monitor location.

The attachments to this document contain Figures 2 and 3, which provide graphical information concerning the ambient monitoring network in the Baton Rouge area and meteorological data. Figure 2, Baton Rouge Ozone and Ozone Precursor Monitoring Network, present s locations of major stationary sources, and locations of ambient monitors with their design values. Figure 3

, Baton Rouge Ozone and

Ozo ne Precursor Monitoring Network with Wind Trajectories, includes an overlay of the back trajectories characterizing where the centerline of the air mass originated for the 24 hours preceding the

afternoon of the violation. An examination of t he 24

- hour back trajectories for the recent five years of

violations of the 0.075 ppm standard at the LSU monitor indicates that emissions from Pointe Coupee Parish do not appear to contribute to observed violations of the 2008 ozone NAAQS in East Baton

Ro uge Parish. For the three

- year period 2008

- 2010, n o wind back trajectories traverse through Pointe Coupee Parish for days with ozone concentrations above 0.075 ppm at the LSU site. Looking back a

little further to the 2006

- 2007 period, there were two days out of 25 with back trajectories that traversed Pointe Coupee Parish . One of these centerline trajectories barely went through the southwest corner of Pointe Coupee parish

, and the main point source (Big Cajun) is located in the northeast part of the paris h. So it is unlikely emissions the largest source in the parish contributed to the violating monitor on this day

. F or the five

- year 2006

- 2010 time period the two trajectories through Pointe Coupee parish are

less than five percent of all days with ozone co ncentrations greater than 0.075 ppm at the LSU site

.

Conversely, examination of the back trajectory data depicted in Figure 3 indicates that emissions from Ascension, Iberville, Livingston, and West Baton Rouge Parishes could contribute at times to nonattainment in East Baton Rouge Parish.9 

### Factor 4 : Geography/topography (mountain ranges or other air basin boundaries)

The geography/topography analysis evaluates the physical features of the land that might affect the airshed and, therefore, the distribution of ozone over the area

. The Baton Rouge area does not have any geographical or topographical barriers significantly limiting air pollution transport within its ai r shed

. Therefore, this factor did not play a significant role in this evaluation

.



### Factor 5 : Jurisdictional boundaries

Once we identified the general areas we anticipated we would recommend should be included in the

nonattainment area , we 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

. Examples of jurisdi ctional boundaries include existing or prior nonattainment area boundarie s for ozone or other urban

- scale pollutants, parish

lines , air district boundaries , township boundarie s, areas covered by a metropolitan planning organization, state lines, Reservation boundarie s, and urban growth boundar ies

. Where existing jurisdictional boundaries were not adequate or appropriate to describe the nonattainment area, other clearly defined and permanent landmarks or geographic c oordinates were considered.

The Baton Rouge area has previously established nonattainment boundaries associated with the 1

- hour

and 1997 8

- hour ozone N AAQS

, the latter of which encompassed all of Ascension, East Baton Rouge, Iberville, Livingston, and West Baton Rouge Parishes

. Louis iana has recommended a different boundary for the 2008 ozone NAAQS , limiting their recommended nonattainment area to East Baton Rouge Parish, which has the only ambient monitor indicating a violation of the 2008 ozone standard

. For

evaluation of the boundary for the 2008 ozone nonattainment area, EPA gave strong consideration to the nonattainment area boundary for the 1997 ozone standard.



### Conclusio n

Based on the assessment of the factor s described above

, EPA has concluded that the following parishes should be included as part of the Baton Rouge nonattainment area because they are either violating the

2008 ozone NAAQS or contributing to a violation in a nearby area : Ascension, East Baton Rouge, Iberville, Livingston, and West Baton Rouge Parishes. The se are the same parishes that were included in the Baton Rouge nonattainment area for the 1997 ozone NAAQS

. The air quality monitors in East Baton Rouge Parish indicate a violation of the 2008 ozone NAAQS based on the 2010 design value ; therefore

this parish is included in the nonattainment area

.

Ascension, Iberville, Livingston, and West Baton Rouge are nearby parishes that do not have monitors indicating a violation of the NAAQS based on 2008

- 2010 data. Based on the five factors discussed previously and the interrelation of these factors, EPA has concluded that these parishes contribute

, through emissions from point sources and non

- point sources (e.g., vehicles and other small area sources)

, to the ozone concentrations in violation of the 2008 ozone NAAQS in East Baton Rouge

Parish

.

Ascension, East Baton Rouge, Iberville, Livingston, Pointe Coupee, and West Baton Rouge Parishes have among the highest NO x and VOC emissions in the area. Pointe Coupee Parish is not being

included in the 2008 ozone nona ttainment area because analysis of back trajectory meteorological data

and locations of emission sources indicate s that the emissions from Pointe Coupee did not likely10 contribute to more than one observed violation of 2008 ozone NAAQS in East Baton Rouge Parish in a five year period . We also note that most of the emissions of NO x from Pointe Coupee are emitted by a single point source in the northeast corner of the parish. Additionally, this rural parish did not have a significant growth in population or V MT over the 2000 to 2010 period

.

Finally, the parishes of Ascension, East Baton Rouge, Iberville , Livingston, and West Baton Rouge are the most densely populated in the Baton Rouge area , and some of these parishes are having large increases in population

. Collectively, these five parishes account for almost all of the VMT and population growth (2000

- 2010) within Baton Rouge

- Pierre Part CSA

.

Therefore, in conclusion of our review/analyses of the five factors for the parishes in the Baton Rouge

Pierre Part CSA

, we are designating the Baton Rouge 2008 8

- hour Ozone nonattainment area be comprised of the following five parishes: Ascension, East Baton Rouge, Iberville, Livingston, and West Baton Rouge.11 

### ATTACHMENTS

Figure 2

. Baton Rouge Ozone and Ozone Precursor Monitoring Network, with Population Density.

Figure 3

. Overlay of 24

- hour HYSPLIT back trajectories of all 75 ppb exceedances at the LSU monitor

for the 2006

- 2010 period

.

Figure 4

. Population Density Change Percentage Between 2000 and 201 0 Census for Baton Rouge Ozone and Ozone Precursor Monitoring Network.12 Figure 2

- Baton Rouge Ozone and Ozo ne Precursor Monitoring Network, with Population Density13 Figure 3

– Overlay of 24

- hour HYSPLIT back trajectories of all 75 ppb exceedances at the LSU monitor for the 200 8

- 2010 period.14 Figure 4

- Population Density Change Percentage Between 2000 and 2010 Census

for Baton Rouge Ozone and Ozone Precursor Monitoring Network

.