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Technical Support Document (TSD)

LOUISIANA 

Area Designations For the 

2010 SO2 Primary National Ambient Air Quality Standard 

Summary

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

either “nonattainment,” “attainment” or “unclassifiable” for the 2010 1-hour sulfur dioxide (SO2) 

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 identifies the county (parish) in Louisiana that EPA is 

initially designating “nonattainment” based on monitored violations. The EPA is not yet 

prepared to designate other areas in Louisiana.

Table 1. Nonattainment Area Designations for Louisiana 

Area 

Louisiana’s 

Recommended 

Designation of 

Area/County (Parish) 

EPA’s Designation of 

Area/County (Parish) 

St. Bernard Parish, LA Nonattainment Nonattainment 

Background

On June 2, 2010, EPA revised the primary SO2 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 99th percentile of 1-

hour daily maximum concentrations 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). The 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 SO2. 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-hour 

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 SO2 has not 

been revised, so EPA is not designating areas in this process on the basis of the secondary 

standard. 
2 

EPA’s SO2 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. For the 2010 SO2 NAAQS, 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 State Commissioner through a 

letter signed by the Regional Administrator of any intended modifications. If a state or tribe did 

not submit designation recommendations, EPA is promulgating the designations that it deems 

appropriate. If a state or tribe disagreed with EPA’s intended area designations, it had an 

opportunity to demonstrate why any proposed modification is 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 has 

evaluated in determining boundaries for areas designated nonattainment. These 5 factors 

include: 1) air quality data; 2) emissions and emissions-related data (location of sources and 

potential contribution to ambient SO2 concentrations); 3) meteorology (weather/transport 

patterns); 4) geography/topography (mountain ranges or other air basin boundaries); and 5) 

jurisdictional boundaries (e.g., counties, air districts, pre-existing nonattainment areas, 

reservations, metropolitan planning organization), among any other information deemed to be 

relevant to establishing appropriate area designations and boundaries for the 1-hour SO2 NAAQS. 

The March 24, 2011, designations guidance memo recommended that area boundaries be 

defaulted to the county boundary unless additional information justifies a larger or smaller 

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, tribes 

and/or EPA may support a different boundary than that of a default county boundary. 

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

by the State of Louisiana for designations of the 1-hour SO2 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 SO2 NAAQS, based on the most recent three years of air quality monitoring data, or 

contributes to a violation in a nearby area. 

2) Recommended nonattainment area – an area that a state or tribe 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 SO2 NAAQS - 75 ppb, national ambient air quality standard for SO2 promulgated in 

2010. Based on the 3-year average of the 99th percentile of the annual distribution of daily 

maximum1-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. 

State’s Recommendation Letter

In May 2011, Secretary Peggy Hatch, Secretary of the Louisiana Department of Environmental 

Quality (LDEQ), recommended that 20 parishes be designated as “unclassifiable” for the 2010 

SO2 NAAQS based on the absence of both monitored air quality data and of a modeling 

demonstration showing attainment of the standard.1

 Secretary Hatch also recommended that 42 

parishes be designated as “attainment” for the 2010 SO2 NAAQS. For 4 of these parishes, the 

attainment recommendation is based on monitored air quality data from regulatory and nonregulatory monitors with the absence of a modeling demonstration showing attainment of the 

standard. For 38 parishes, the attainment recommendation is based on 2009 SO2 emissions from 

sources in the respective parishes. According to the 2009 Louisiana emissions inventory, these 

38 parishes each have total emissions less than 75 SO2 tons per year (tpy). Secretary Hatch’s 

May 2011 letter also recommended that St. Bernard Parish and West Baton Rouge Parish be 

designated as “nonattainment” for the 2010 SO2 NAAQS based on monitored violations. 

Secretary Hatch’s May 2011 recommendations were based on 2008-2010 monitored air quality 

data. This is in accordance with the March 24, 2011, designations guidance memo from Stephen 

D. Page in which we stated our expectation that states and tribes would review available SO2

monitoring data from 2008-2010 in providing their recommendations to EPA. We also stated in 

the March 24, 2011, memo that we intended to consider 2011 SO2 monitoring data in 

formulating any intended modifications to the states’ and tribes’ recommendations if such data 

were to become available prior to EPA issuing the 120 day letters. Since 2011 data are currently 

available, in the analysis presented in this TSD, EPA is considering 2009-2011 monitored air 

quality data for all areas in Louisiana, with the exception of West Baton Rouge Parish. Since 

2012 data for the monitor in West Baton Rouge Parish was early certified by Louisiana, EPA is 

considering 2010-2012 monitored air quality data for this particular monitor. The 2010-2012 

data for West Baton Rouge meets the 2010 SO2 NAAQS. 

Consequently, this final initial designation does not address West Baton Rouge Parish, which 

will be further addressed in a subsequent round of designations. 

 

1

 May 26, 2011, letter from Peggy M. Hatch, Secretary, Louisiana Department of Environmental Quality, to Al 

Armendariz, Regional Administrator, EPA Region 6. 
4 

Nonattainment Designations

Technical Analysis for St. Bernard Parish

Introduction 

This technical analysis identifies St. Bernard Parish as having a monitor that violates the 2010 

SO2 NAAQS, and evaluates nearby parishes for contributions to SO2 concentrations in the area. 

EPA has evaluated St. Bernard Parish and nearby parishes based on the weight of evidence of the 

factors recommended in the March 24, 2011, designations guidance memo. 

Figures 1 and 2 are maps of St. Bernard Parish, showing the location and design values of air 

quality monitors in the area, the parishes surrounding the violating air quality monitor, and the 

location of SO2 point sources with 2008 emissions greater than 100 SO2 tpy based on the 2008 

National Emissions Inventory (NEI). As shown in the legend for Figure 1, the diamonds 

represent regulatory SO2 monitors (red=violating, green=attaining) and the circles represent SO2

emissions sources. In Figure 2, the stars represent regulatory SO2 monitors (red=violating, 

blue=attaining); the green circles represent SO2 emissions sources, with the size of the circle 

proportional to the source’s 2008 NEI SO2 emissions (numbers shown are 2008 NEI SO2

emissions in tpy). As shown in the figures, only one of the three regulatory monitors in St. 

Bernard Parish has a 2009-2011 design value above the 2010 1-hour SO2 NAAQS. The 

violating monitor, shown as a red diamond in Figure 1 and a red star in Figure 2, is the 

Chalmette-Vista monitor (EPA Site ID 22-087-0007), with a 2009-2011 design value of 287 ppb. 

The other two regulatory monitors in St. Bernard Parish have design values under the 2010 1-

hour SO2 NAAQS. These monitors, shown as blue stars in Figure 2, are the Chalmette-High 

School monitor (EPA Site ID 22-087-0009), with a 2009-2011 design value of 64 ppb 

(incomplete data), and the Meraux monitor (EPA Site ID 22-087-0004), with a 2009-2011 design 

value of 26 ppb. Note that Figure 1 depicts only the Meraux monitor as having a design value 

under the standard (i.e., shown as a green diamond), as three full years of data are not available 

from the Chalmette-High School monitor. 
5 

Figure 1. St. Bernard Parish 1-hr SO2 NAAQS Nonattainment Area 
6 

Figure 2. St. Bernard Parish 1-hr SO2 NAAQS Nonattainment Area (close-up) 

Based on EPA's technical analysis described below, EPA is initially designating St. Bernard 

Parish as nonattainment for the 2010 SO2 NAAQS, based upon currently available information. 

EPA is not yet prepared to designate other areas of Louisiana. Areas and sources that we are not 

yet prepared to conclude are contributing to the monitored violation or other possible violations 

are not included in this initial nonattainment area, and will be addressed in a subsequent round of 

designations. 
7 

Detailed Assessment

Air Quality Data 

This factor considers the SO2 air quality monitoring data, including the design values (in ppb) 

calculated for all air quality monitors in St. Bernard Parish, based on data for the 2009-2011 

period. 

Secretary Hatch’s nonattainment recommendation for St. Bernard Parish was based on 2008-

2010 data2 from Federal Reference Method (FRM) or Federal Equivalent Method (FEM) 

monitors located in the state, in accordance with 40 CFR Part 53. As discussed elsewhere in this 

TSD, EPA is considering 2009-2011 air monitoring data for St. Bernard Parish in the technical 

analysis presented in this TSD. The 2009-2011 SO2 NAAQS design values for the monitors in 

St. Bernard Parish are shown in Table 2. 

Table 2. Air Quality Data for Nonattainment Designations in Louisiana 

Parish 

State 

Recommended 

Nonattainment? 

Monitor 

Name* 

Monitor Air 

Quality 

System ID 

Monitor 

Location 

SO2 Design 

Value, 

2008-2010 

(ppb) 

SO2 Design 

Value, 

2009-2011 

(ppb) 

St. Bernard 

Parish, LA Yes 

Meraux 22-087-0004 4101 Mistrot 

Drive 32 26 

ChalmetteVista 22-087-0007 

24 E. 

Chalmette 

Circle 

297 287 

ChalmetteHigh 

School 

22-087-0009 

1100 E. 

Judge Perez 

Drive 

60 64** 

* The monitor in bold has the highest 2009-2011 design value in the parish. 

** Design Value based on incomplete data. 

St. Bernard Parish shows a violation of the 2010 SO2 NAAQS. Therefore, some area in the 

parish and possibly additional areas in surrounding parishes must be designated nonattainment. 

The absence of a violating monitor alone is not a sufficient reason to eliminate nearby parishes as 

candidates for nonattainment status. Each area has been evaluated based on the weight of 

evidence of the five factors and other relevant information. 

As shown in Table 2, the Chalmette-Vista monitor (Air Quality System ID 22-087-0007) in St. 

Bernard Parish has a 2009-2011 design value of 287 ppb, which exceeds the NAAQS and is 

therefore violating the standard. The Chalmette-High School monitor (Air Quality System ID 

22-087-0009) and the Meraux monitor (Air Quality System ID 22-087-0004), which are also 

located in St. Bernard Parish, have 2009-2011 design values of 64 ppb (incomplete data) and 26 

ppb, respectively. The violating Chalmette-Vista monitor is approximately 5.1 km away from 

the Chalmette-High School monitor, and 2.2 km away from the Meraux monitor. This suggests 

that the emissions source or sources causing or contributing to the recorded violation of the 

Chalmette-Vista monitor are in closer proximity to the Chalmette-Vista monitor than to the two 

 

2

 May 31, 2011, letter from Peggy M. Hatch, Secretary, Louisiana Department of Environmental Quality, to Al 

Armendariz, Regional Administrator, EPA Region 6. 
8 

other monitors in St. Bernard Parish, and/or that the Chalmette-Vista monitor is located directly 

downwind from the emissions source(s) causing the violation. There are no other regulatory SO2

monitors within 100 km of the violating Chalmette-Vista monitor. The regulatory SO2 monitor 

located nearest to the St. Bernard Parish monitors is located in East Baton Rouge Parish 

(approximately 130 km away from the Chalmette-Vista monitor). Air quality data from a 

monitor located in a nearby parish could potentially be used to indicate whether sources in that 

parish are contributing to the monitored violation at the Chalmette-Vista monitor. In this case, 

however, regulatory SO2 monitors in neighboring parishes are located too far away from the St. 

Bernard Parish violating monitor (Chalmette-Vista) for their design values to indicate whether or 

not emissions sources from these parishes may be contributing to the St. Bernard Parish violating 

monitor. 

Emissions and Emissions-Related Data

Evidence of SO2 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. In considering 

this factor, EPA evaluated county level emission data for SO2 and any growth in SO2 emitting 

activities since the date represented by those emissions data. 

Emissions 

EPA recognizes that there may be new information on any changes in emissions that may have 

occurred after 2008, and would consider more recent years if available. Louisiana did not 

provide updated emissions information, therefore EPA relied on the 2008 NEI emissions data 

(NEI08V3) to identify sources that could potentially be contributing to a violation. 

Table 3 shows total emissions of SO2 according to the 2008 NEI (in tpy) in St. Bernard Parish 

and potentially contributing surrounding parishes, as well as emissions from sources emitting 

greater than 100 tpy of SO2 in these parishes. 

Table 3. 2008 NEI SO2 Emissions (NEI08V3) in St. Bernard Parish and Surrounding 

Parishes 

Parish 

Facility 

Located in 

State 

Recommended 

Nonattainment 

Area? 

Facility Name, 

Address, Coordinates, 

and EIS (or State 

Facility ID)

Facility 

Emissions 

(tpy) 

Approximate 

Facility 

Distance from 

St. Bernard 

Parish Violating 

Monitor (km) 

Total 

Parish SO2

Emissions 

(tpy) 

St. Bernard 

Parish, LA Yes 

Rain CII Carbon LLCChalmette Coke Plant 

700 Coke Plant Rd. 

(29.9375, -89.97694) 

EIS ID 5608111 

4284 tpy 0.8 6267 
9 

Chalmette Refining 

LLC- Chalmette 

Refinery 

500 W St Bernard Hwy 

(29.9379, -89.9699) 

EIS ID 8020411 

250 tpy 1.0 

Murphy Oil USA Inc.- 

Meraux Refinery 

2500 E St Bernard Hwy 

(29.93022, -89.94492) 

EIS ID 7355411 

753 tpy 3.4 

St. Charles 

Parish, LA No 

Valero Refining Co. - 

New Orleans LLC- St. 

Charles Refinery 

14902 River Rd 

EIS ID 7449311 

238 tpy 40.4 

7824 

Rain CII Carbon LLCNorco Coke Plant 

801 Prospect Ave 

(30.00194, -90.39694) 

EIS ID 8020911 

2350 tpy 41.0 

Shell Chemical LPNorco Chemical PlantEast Site 

15536 River Rd 

(30.00111, -90.40694) 

EIS ID 8239511 

1020 tpy 42.0 

Motiva Enterprises 

LLC- Norco Refinery 

15536 River Rd 

(29.99537, -90.41017) 

EIS ID 8020811 

769 tpy 42.2 

Union Carbide Corp.- 

St. Charles Operations 

355 Hwy 3142 Gate 28 

(29.98229, -90.45562) 

EIS ID 7202911 

416 tpy 46.4 
10 

Entergy Louisiana 

LLC- Waterford 1&2 

Generating Plant 

17705 River Rd 

(29.9994, -90.4758) 

EIS ID 5609311 

1803 tpy 48.5 

Orleans 

Parish, LA No N/A None > 100 tpy N/A 1900 

Plaquemines 

Parish, LA No 

Chevron Oronite Co. 

LLC- Oak Point Plant 

10285 Hwy 23 S 

(29.81028, -90.01139) 

EIS ID 8018711 

262 tpy 15.3 

9316 Conoco Phillips Co.- 

Alliance Refinery 

15551 Hwy 23 

(29.684887, -89.97613) 

EIS ID 7203711 

2785 tpy 29.0 

Jefferson 

Parish, LA No 

Cornerstone Chemical 

Co. 

10800 River Rd 

(29.95788, -90.26568) 

EIS ID 7228511 

863 tpy 27.9 3068 

St. Tammany 

Parish, LA No N/A None > 100 tpy N/A 154 

See also Figures 1 and 2 above for facility location in relation to air quality monitors. As shown 

in Figure 1, the emissions sources closest to the violating monitor are located in St. Bernard 

Parish. This suggests that sources in St. Bernard Parish are causing or contributing to the 

monitored violation of the 2010 SO2 NAAQS. Table 3 shows there are three sources within 30 

km from the St. Bernard Parish violating monitor, located in neighboring parishes, and with 2008 

NEI SO2 emissions greater than 100 tpy (each). One of these sources (863 SO2 tpy, 2008 NEI) is 

in Jefferson Parish, and is located approximately 27.9 km from the St. Bernard violating monitor. 

The remaining two sources (262 SO2 tpy and 2785 SO2 tpy, 2008 NEI) are in Plaquemines 

Parish, and are located approximately 15.3 km and 29 km away from the St. Bernard violating 

monitor, respectively. However, these sources each have 2008 NEI SO2 emissions that are lower 

than that of the largest point source in St. Bernard Parish, and they are all located further away 

from the violating monitor than are St. Bernard Parish’s own sources. Based on this information, 

we are not yet prepared to conclude that the emissions from these sources in Jefferson Parish and 

Plaquemines Parish contribute to the monitored violation in St. Bernard Parish. All the sources 

in St. Charles Parish are located at least 40 km from the St. Bernard Parish violating monitor, and 

each have SO2 emissions that are lower than that of the largest point source in St. Bernard Parish. 
11 

Two other nearby parishes, Orleans and St. Tammany Parishes, do not have any sources with 

emissions greater than 100 tpy. Based on this information, we are not prepared to conclude that 

sources in St. Charles, Orleans, and St. Tammany Parishes contribute to the violating monitor’s 

design values. All of these sources and areas will be further addressed in a subsequent round of 

designations. 

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 3 represents 

emissions levels taking into account any control strategies implemented on stationary sources in 

St. Bernard and surrounding parishes up to and including 2008. 

Meteorology (weather/transport patterns)

Evidence of source-receptor relationships between specific emissions sources and high SO2

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 30 years of National Weather Service data on average frequency of wind 

direction by season. The National Weather Service data for St. Bernard Parish is shown in Table 

4. EPA also considered recent hourly meteorological data to determine which wind vectors were 

associated with monitored 1-hour SO2 NAAQS violations. The meteorological data used in this 

analysis were based on 2009-2011 data co-located with the St. Bernard Parish violating site. 

This data is presented in Table 5. This meteorological data may provide evidence of the 

potential for SO2 emissions sources located upwind of a violating monitor to contribute to 

ambient SO2 levels at the violation location. 

Table 4. National Weather Service 30-Year Average Frequency (%) of Wind Direction by 

Season for St. Bernard Parish 

 Season1

Wind Direction Winter Spring Summer Autumn 

North-northeast 21.1 13.7 12.3 23.3 

East-northeast 15.0 9.5 11.1 21.7 

East-southeast 11.7 13.9 10.5 15.3 

South-southeast 11.7 19.2 11.0 10.7 

South-southwest 11.5 18.5 19.1 7.6 

West-southwest 7.0 8.0 14.2 4.4 

West-northwest 8.1 7.9 13.3 6.4 

North-northwest 14.0 9.4 8.4 10.6 
12 

 1 For purposes of this table, winter is defined as the months of December, January, 

 and February; spring is March, April, and May; summer is June, July, and August; 

 and autumn is September, October, and November. 

The 30-year average frequency of wind direction data for St. Bernard Parish shows that in 

general, the prevailing surface winds blow into St. Bernard Parish primarily from the northnortheast, east-northeast, south-southwest, south-southeast, and east-southeast. As shown in 

Table 5, monitored 1-hour SO2 NAAQS exceedance events during 2009-2011 occurred 

throughout all seasons, but primarily took place in the spring and summer months in 2009 and 

2010 and in the spring months in 2011. Table 4 shows that in winter, the wind has historically 

blown into St. Bernard Parish to a greater extent from the north-northeast (21.1% of time). In 

spring, the wind has historically blown into St. Bernard Parish to a greater extent from the southsoutheast (19.2%) and south-southwest (18.5%). In summer, the wind has historically blown 

into St. Bernard Parish to a greater extent from the south-southwest (19.1%). The data suggest 

that on months with the highest observed SO2 levels in 2009-2011 (i.e., winter, spring, and 

summer), the prevailing surface winds were to a greater extent from directions that correspond to 

the location of sources in St. Bernard Parish (see Figures 1 and 2) and not to those of sources in 

surrounding parishes. 

As stated above, EPA also analyzed wind direction as measured by the Chalmette-Vista monitor 

specifically during days with monitored 1-hr SO2 NAAQS hourly exceedances (i.e., violation 

days) in 2009-2011 (see Table 5). Although some violation days had multiple hourly SO2

exceedances, only the maximum 1-hour SO2 concentration and the corresponding wind direction 

during that hour are shown for each violation day. 

Table 5. Wind Direction during 1-hour SO2 NAAQS Exceedances at Chalmette-Vista 

Monitor in St. Bernard Parish- AQS Site ID 22-087-0007 

2009 1-hour SO2 NAAQS Hourly Exceedances 

Date1 Time2 1-hr SO2

Concentration (ppb) 

Wind Direction3

(Compass °) 

Wind Direction3 

(Compass Point) 

1/2/2009 06:00 109 191 South 

1/3/2009 12:00 159 186 South 

1/5/2009 18:00 200 188 South 

1/6/2009 07:00 96 192 South-southwest 

1/18/2009 02:00 87 194 South-southwest 

1/21/2009 22:00 120 189 South 

1/22/2009 19:00 95 175 South 

1/23/2009 00:00 88 176 South 

2/2/2009 07:00 120 238 West-southwest 

2/10/2009 05:00 89 190 South 

2/11/2009 05:00 316 177 South 

2/13/2009 14:00 101 192 South-southwest 

2/17/2009 23:00 81 185 South 

2/20/2009 20:00 111 189 South 

2/21/2009 20:00 126 185 South 

2/27/2009 03:00 194 177 South 
13 

3/8/2009 10:00 85 194 South-southwest 

3/10/2009 14:00 108 181 South 

3/11/2009 20:00 147 187 South 

3/14/2009 07:00 206 179 South 

3/25/2009 23:00 245 183 South 

3/26/2009 00:00 285 182 South 

3/27/2009 23:00 152 193 South-southwest 

3/31/2009 09:00 83 195 South-southwest 

4/5/2009 04:00 166 182 South 

4/9/2009 06:00 311 181 South 

4/10/2009 03:00 314 184 South 

4/12/2009 21:00 279 181 South 

4/19/2009 10:00 192 184 South 

4/23/2009 12:00 148 185 South 

4/24/2009 14:00 114 176 South 

5/1/2009 19:00 249 185 South 

5/2/2009 23:00 298 186 South 

5/3/2009 21:00 239 182 South 

5/4/2009 00:00 291 181 South 

5/5/2009 23:00 104 184 South 

5/6/2009 21:00 350 186 South 

5/7/2009 15:00 83 198 South-southwest 

5/8/2009 23:00 373 183 South 

5/9/2009 20:00 281 184 South 

5/10/2009 17:00 275 182 South 

5/11/2009 18:00 88 178 South 

5/12/2009 17:00 214 181 South 

5/14/2009 10:00 83 171 South 

5/24/2009 20:00 272 182 South 

5/25/2009 00:00 147 203 South-southwest 

5/26/2009 06:00 107 201 South-southwest 

6/1/2009 20:00 232 194 South-southwest 

6/7/2009 20:00 187 189 South 

6/8/2009 02:00 99 190 South 

6/9/2009 16:00 85 194 South-southwest 

6/10/2009 16:00 225 179 South 

6/19/2009 20:00 150 187 South 

6/24/2009 16:00 86 319 Northwest 

6/26/2009 18:00 188 189 South 

6/27/2009 20:00 130 196 South-southwest 

7/1/2009 21:00 79 191 South 

7/3/2009 16:00 168 179 South 

7/5/2009 16:00 115 195 South-southwest 

7/6/2009 19:00 238 188 South 

7/10/2009 17:00 123 185 South 

7/16/2009 15:00 81 180 South 

7/20/2009 18:00 78 184 South 

7/21/2009 17:00 94 187 South 

7/22/2009 02:00 110 187 South 

7/25/2009 15:00 131 181 South 

7/27/2009 10:00 95 184 South 

7/28/2009 06:00 314 186 South 
14 

7/30/2009 07:00 217 178 South 

7/31/2009 17:00 86 194 South-southwest 

8/1/2009 15:00 84 223 Southwest 

8/6/2009 02:00 123 197 South-southwest 

8/30/2009 18:00 187 190 South 

9/14/2009 08:00 139 190 South 

9/15/2009 02:00 124 184 South 

9/16/2009 19:00 104 191 South 

9/18/2009 12:00 97 189 South 

9/20/2009 18:00 114 187 South 

10/1/2009 08:00 177 191 South 

10/4/2009 14:00 155 179 South 

10/6/2009 07:00 178 185 South 

10/13/2009 23:00 116 205 South-southwest 

10/14/2009 05:00 83 198 South-southwest 

10/22/2009 22:00 93 194 South-southwest 

10/30/2009 16:00 161 187 South 

11/14/2009 22:00 119 193 South-southwest 

11/15/2009 22:00 90 189 South 

11/16/2009 16:00 122 182 South 

11/29/2009 11:00 118 177 South 

11/30/2009 06:00 260 180 South 

12/8/2009 14:00 238 178 South 

12/14/2009 03:00 135 176 South 

2010 1- hour SO2 NAAQS Hourly Exceedances 

Date1 Time2 1-hr SO2 Wind Direction3 Wind Direction3

1/20/2010 17:00 158 178 South 

1/24/2010 04:00 181 178 South 

2/14/2010 18:00 217 181 South 

2/25/2010 20:00 125 192 South-southwest 

2/28/2010 23:00 112 191 South-southwest 

3/10/2010 15:00 147 178 South 

3/23/2010 21:00 107 181 South 

3/31/2010 22:00 117 186 South 

4/1/2010 18:00 90 181 South 

4/3/2010 06:00 103 185 South 

4/6/2010 16:00 119 180 South 

4/7/2010 19:00 246 186 South 

4/8/2010 12:00 80 184 South 

5/20/2010 16:00 151 185 South 

5/21/2010 19:00 137 191 South 

5/22/2010 20:00 160 186 South 

5/23/2010 00:00 100 194 South-southwest 

5/29/2010 16:00 131 195 South-southwest 

5/30/2010 17:00 135 184 South 

5/31/2010 14:00 213 175 South 

6/1/2010 16:00 98 197 South-southwest 

6/2/2010 15:00 143 185 South 

6/3/2010 15:00 105 203 South-southwest 

6/4/2010 18:00 230 189 South 

6/5/2010 18:00 254 193 South-southwest 
15 

6/6/2010 15:00 112 190 South 

6/10/2010 18:00 111 194 South-southwest 

6/11/2010 08:00 110 182 South 

6/12/2010 20:00 135 190 South 

6/26/2010 00:00 115 195 South-southwest 

7/5/2010 08:00 153 191 South 

7/9/2010 14:00 83 198 South-southwest 

7/17/2010 18:00 77 191 South-southwest 

7/25/2010 20:00 230 181 South 

7/26/2010 18:00 127 183 South 

7/27/2010 15:00 143 197 South-southwest 

8/2/2010 19:00 106 184 South 

8/17/2010 23:00 230 182 South 

8/18/2010 00:00 176 188 South 

8/19/2010 10:00 83 176 South 

10/24/2010 19:00 153 175 South 

10/25/2010 21:00 244 180 South 

10/26/2010 20:00 242 180 South 

10/27/2010 13:00 163 177 South 

10/31/2010 22:00 125 183 South 

11/1/2010 01:00 83 185 South 

11/8/2010 21:00 95 198 South-southwest 

11/22/2010 13:00 106 171 South 

11/23/2010 07:00 242 182 South 

11/24/2010 12:00 136 180 South 

11/25/2010 15:00 208 180 South 

11/29/2010 23:00 378 180 South 

11/30/2010 03:00 149 185 South 

12/11/2010 12:00 248 181 South 

12/15/2010 23:00 266 181 South 

12/16/2010 01:00 243 177 South 

12/21/2010 09:00 235 192 South-southwest 

12/30/2010 14:00 247 178 South 

2011 1- hour SO2 NAAQS Hourly Exceedances

Date1 Time2 1-hr SO2

Concentration (ppb)

Wind Direction3 

(Compass °)

Wind Direction3 

(Compass Point)

1/1/2011 04:00 180 176 South 

1/5/2011 04:00 245 176 South 

1/15/2011 21:00 186 195 South-southwest 

1/16/2011 00:00 78 202 South-southwest 

1/29/2011 23:00 127 178 South 

1/30/2011 03:00 89 173 South 

2/1/2011 12:00 214 179 South 

2/15/2011 18:00 135 181 South 

2/20/2011 03:00 230 174 South 

2/21/2011 01:00 96 178 South 

2/24/2011 18:00 238 178 South 

2/27/2011 09:00 145 177 South 

3/12/2011 18:00 213 175 South 
16 

3/14/2011 13:00 162 180 South 

3/16/2011 23:00 92 186 South 

3/17/2011 00:00 83 189 South 

3/18/2011 07:00 143 176 South 

3/19/2011 19:00 117 192 South-southwest 

4/2/2011 21:00 185 184 South 

4/3/2011 16:00 178 187 South 

4/4/2011 01:00 243 178 South 

4/7/2011 15:00 153 188 South 

4/8/2011 18:00 180 179 South 

4/9/2011 02:00 127 176 South 

4/10/2011 02:00 168 188 South 

4/11/2011 03:00 190 179 South 

4/15/2011 07:00 237 184 South 

4/18/2011 17:00 300 182 South 

4/19/2011 05:00 159 177 South 

4/20/2011 02:00 128 178 South 

4/23/2011 12:00 121 188 South 

4/25/2011 23;00 204 180 South 

4/26/2011 00:00 202 178 South 

4/27/2011 07:00 255 186 South 

5/6/2011 19:00 170 188 South 

5/9/2011 18:00 218 178 South 

5/10/2011 16:00 137 179 South 

5/11/2011 17:00 133 179 South 

5/13/2011 04:00 126 171 South 

5/21/2011 17:00 149 180 South 

5/22/2011 17:00 224 178 South 

5/23/2011 12:00 153 181 South 

5/24/2011 16:00 198 179 South 

5/25/2011 15:00 173 184 South 

5/26/2011 02:00 129 199 South-southwest 

5/28/2011 01:00 76 192 South-southwest 

6/14/2011 17:00 85 137 Southeast 

6/19/2011 20:00 111 144 Southeast 

6/20/2011 16:00 86 170 South 

6/21/2011 03:00 131 190 South 

6/22/2011 16:00 198 182 South 

6/24/2011 16:00 165 168 South-southeast 

6/26/2011 20:00 228 142 Southeast 

6/27/2011 19:00 165 135 Southeast 

7/3/2011 17:00 91 359 North 

8/6/2011 19:00 358 186 South 

8/20/2011 11:00 90 191 South 

8/23/2011 16:00 86 215 Southwest 

9/4/2011 09:00 223 171 South 

9/5/2011 02:00 296 169 South 

9/13/2011 17:00 196 202 South-southwest 

9/19/2011 11:00 115 357 North 

9/25/2011 23:00 177 183 South 

9/26/2011 02:00 226 189 South 
17 

10/23/2011 21:00 189 197 South-southwest 

10/27/2011 23:00 82 188 South 

11/9/2011 08:00 139 187 South 

11/11/2011 20:00 80 186 South 

11/13/2011 13:00 127 180 South 

11/14/2011 15:00 218 181 South 

11/15/2011 23:00 350 182 South 

11/16/2011 04:00 375 184 South 

11/26/2011 23:00 299 189 South 

12/5/2011 11:00 256 180 South 

12/16/2011 04;00 122 193 South-southwest 

12/20/2011 12:00 159 194 South-southwest 

1

 In some cases, there was more than one hourly exceedance on a given day. However, only the maximum 1-hour 

SO2 concentration and corresponding wind direction during that hour are shown for each violation day. 2

 Based on Local Standard Time. 

3

 Wind Direction corresponds to the specific time interval during which the 1-hour SO2 NAAQS hourly exceedance 

took place. 

As shown in Table 5, there were a total of 92 violation days in 2009, 58 violation days in 2010, 

and 76 violation days in 2011 at the Chalmette-Vista monitor in St. Bernard Parish. The data 

shows that from 2009-2011, the prevailing surface winds were predominantly from the south 

during 1-hour SO2 NAAQS hourly exceedances. The data shows that prevailing surface winds 

were also often from the south-southwest during 1-hour SO2 NAAQS hourly exceedances 

(although to a much lesser extent than from the south). The direction from which wind blew into 

St. Bernard Parish during 1-hour SO2 NAAQS hourly exceedances corresponds to the location of 

the Rain CII Carbon coke plant (depicted in Figures 1 and 2 as a green circle labeled “4284”) and 

the ExxonMobil Refinery Complex (depicted in Figures 1 and 2 as a green circle labeled “250”), 

both located in St. Bernard Parish. Taken together, the wind data in Tables 4 and 5 suggest that 

the Chalmette-Vista monitor in St. Bernard Parish is located downwind from the Rain CII 

Carbon coke plant and the ExxonMobil Refinery in St. Bernard Parish, and that these sources are 

causing the violation of the 1-hour SO2 NAAQS at the Chalmette-Vista monitor. 

 

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

St. Bernard Parish 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 for St. Bernard Parish. 

Jurisdictional boundaries 

As discussed above, our evaluation of the factors indicate that St. Bernard Parish’s own sources 

are causing the violation of the Chalmette-Vista monitor. The State recommended St. Bernard 

Parish to be the area designated nonattainment. Since there are no other data available to support 

a nonattainment boundary smaller than the St. Bernard Parish boundary, the only jurisdictional 

boundary we considered in our evaluation is the parish boundary. 
18 

Other Relevant Information

EPA did not receive additional information from the state relevant to establishing the initial 

nonattainment area boundary for St. Bernard Parish. 

 

EPA’s Area Designations Conclusion for Louisiana

After considering the factors described above and considering and responding to comments 

submitted by the state and the public (see our Response to Comments Document), EPA is 

initially designating St. Bernard Parish as nonattainment (see Table 1). 

An air quality monitor in St. Bernard Parish shows a violation of the 2010 SO2 NAAQS based on 

2009-2011 air quality data. The nonattainment area boundary that EPA describes above is based 

on the following five factors: air quality data, emissions-related data, meteorology, 

geography/topography, and jurisdictional boundaries. Based on the consideration of all the 

relevant and available information, as described above, EPA believes that the boundary 

described herein encompasses the appropriate initial area that does not meet the 2010 SO2

NAAQS, based on monitoring, and the sources that contribute to the monitored violation. 

Based on the consideration of all the relevant and available information, as described above, 

EPA is initially designating St. Bernard Parish as nonattainment for the 2010 SO2 NAAQS. EPA 

is not yet prepared to conclude that the emissions from sources located outside the initial 

nonattainment boundary contribute to the monitored violation or to other possible violations. In a 

subsequent round of designations, we will further address these areas and sources and make final 

initial designation decisions for areas in Louisiana not included in the nonattainment area 

designation addressed in this TSD.