Attachment 1

MISSOURI

Area Designations For the 

24-Hour Fine Particle National Ambient Air Quality Standard

The table below identifies the counties/areas in Missouri that EPA has
designated as not attaining the 2006 24-hour fine particle (PM2.5)
standard.  A county (or part thereof) is designated as nonattainment if
it has an air quality monitor that is violating the standard or if the
county is determined to be contributing to the violation of the
standard. 

 

Area 	Missouri Recommended Nonattainment Counties	EPA’s Designated
Nonattainment Counties

St. Louis, MO-IL	None 	Franklin

Jefferson

St. Charles

St. Louis

City of St. Louis 



EPA has designated the remaining counties in the state of Missouri as
“attainment/unclassifiable.”  

EPA Technical Analysis for St. Louis, MO 

Introduction  

Pursuant to section 107(d) of the Clean Air Act, EPA must designate as
nonattainment those areas that violate the NAAQS and those nearby areas
that contribute to violations.  This technical analysis for the St.
Louis area identifies the counties with monitors that violate the
24-hour PM2.5 standard and evaluates nearby counties for contributions
to fine particle concentrations in the area.  EPA has evaluated these
counties based on the weight of evidence of the following nine factors
recommended in EPA guidance and any other relevant information:  

- pollutant emissions

- air quality data

- population density and degree of urbanization

- traffic and commuting patterns

- growth

- meteorology

- geography and topography

- jurisdictional boundaries

- level of control of emissions sources

EPA also used analytical tools and data such as pollution roses, fine
particle composition monitoring data, back trajectory analyses, and the
contributing emission score (CES) to evaluate these areas. (See
additional discussion of the CES under factor 1 below.)

 

Figure A is a map of the counties in the area. The Figure includes other
relevant information such as the locations and design values of air
quality monitors, the metropolitan area boundary, and counties
recommended as nonattainment by the State.

 

Background

The St. Louis metro area was previously established by EPA as a PM2.5
nonattainment boundary for the 1997 annual PM2.5 NAAQS.  That boundary
included a total of eight full counties and one city (City of St.
Louis), with four of the counties and the city being located in
Missouri.  These same counties, and city, are being designated as
nonattainment for the 2006 24-hour PM2.5 standard.

In December 2007, Missouri recommended that all areas in the state be
designated as attainment  for the 2006 24-hour PM2.5 standard based
primarily on its analysis of air quality data from 2004-2006.  All data
submitted by Missouri related to the violations occurring in Madison
County, IL during 2004-2006, at the Granite City and VFW monitoring
sites are included in this rulemaking docket.  These data are from
Federal Reference Method (FRM) monitors.  The State based its attainment
recommendation on the argument that the two monitors were violating
because of the contributions of direct PM2.5 from one local source, US
Steel in Granite City, Illinois.  

In August 2008, EPA notified Missouri of its intended designations.  In
this letter, EPA also requested that if the State wished to provide
comments on EPA’s intended designation, it should do so by October 20,
2008.  EPA stated that it would consider any additional information
(e.g., on power plants or partial county areas) provided by the state in
making final decisions on the designations.  On October 16, 2008, the
state of Missouri provided its response to EPA’s August letter.  The
information contained in the letter is addressed in EPA’s response to
comments and in this document.

Based on EPA's technical analysis described below, EPA is designating
portions of the St Louis, Missouri area (previously designated
nonattainment for the 1997 annual PM2.5 NAAQS) as nonattainment for the
24-hour PM2.5 NAAQS, based upon currently available information.  These
areas are listed in the table below. The EPA must utilize the most
recent three years of quality assured monitoring data in making these
designations.  In this case, the most current, quality assured monitor
data is from the period 2005-2007.  During the period 2005-2007, the
violating monitors in the St. Louis metro area were both in Madison
County, IL.  These monitors are commonly referred to as the Granite City
and Alton monitors.  (It should be noted that Missouri’s analysis in
response to EPA’s 120-day letter did not include consideration of
violations at the Alton monitor.) 

The following is a technical analysis for the EPA Region 7 (Missouri)
portion of the St. Louis nonattainment area. 

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes:   “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive analytical tool used to consider data
for these factors.  A summary of the CES is included in attachment 2,
and a more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.  NOTE:  The
emissions data used to derive the CES were taken from the 2005 National
Emissions Inventory (NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the St. Louis Area.  Counties that are part of
the St. Louis nonattainment area for the 1997 PM2.5 NAAQS are shown in
boldface.  Counties are listed in descending order by CES.

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total

(tpy)	PM2.5

emissions 

carbon

(tpy)	PM2.5

emissions 

other

(tpy)	SO2

(tpy)	NOx

(tpy)	VOCs

(tpy)	NH3

(tpy)

Madison, IL*	Yes	100	4,945	1,148	3,796	27,320	19,373	15,676	1,393

St. Louis, MO*	No	55	4,221	1,707	2,513	29,966	55,605	54,821	2,954

St. Louis City*	No	48	1,686	625	1,060	12,171	24,702	20,647	439

St. Clair, IL*	Yes	22	1,496	487	1,009	2,142	10,233	10,869	1,281

St. Charles, MO*	No	17	3,694	619	3,075	54,561	20,773	12,419	1,182

Jefferson, MO*	No	16	2,945	824	2,121	45,574	16,722	9,273	493

Randolph, IL**	Partial	9	2,505	306	2,199	24,605	9,384	2,331	993

Franklin, MO*	No	5	2,812	621	2,190	56,767	15,595	5,748	1,818

Monroe, IL*	Yes	5	744	235	508	293	3,057	2,529	654

* Counties in bold represent those in the St. Louis nonattainment area
for the 1997 PM2.5 NAAQS (This table does not include all counties
considered in the 9 factor analysis and those counties not shown had no
factors that indicated that they should be candidates for a
nonattainment status.)

** Part of Randolph County, Illinois is in the 1997 PM2.5 NAAQS
nonattainment area



Table 1.  PM2.5 24-hour Component Emissions, and CESs 

EPA notes that Franklin County, the lowest CES ranked county in Missouri
which EPA is including in the nonattainment area, has a CES score equal
to the lowest scoring Illinois county (Monroe) included in the
nonattainment area (by that State of Illinois and EPA Region 5) and more
than ten times the total PM2.5 direct and precursor emissions of Monroe
County.

By reviewing and comparing 2002 National Emissions Inventory data for
Missouri and Illinois counties, Missouri counties’ potential to
contribute to the violating monitor can be evaluated relative to other
emissions in the metro area.  A review of this data shows that
collectively the point sources in the Missouri counties under review
emit 50-74% of the primary and precursor pollutants of PM 2.5. 
Specifically, Figure 1 and Table 1.1 demonstrate that the Missouri
counties emit approximately 50% of the total tons per year (tpy) of
direct PM2.5, approximately 57% of the total tpy of NOx, and
approximately 74% of the total tpy of SO2 emitted in the nonattainment
area.  The figure and table clearly demonstrate Missouri counties have a
equal or greater PM2.5, emissions and precursors when compared to the
Illinois metro areas included within the nonattainment boundary and
therefore, have the potential to contribute air pollution emissions to
the violating monitors.  

Figure 1:  Missouri counties’ emissions from point sources in the
reviewed counties vs. Illinois counties’ emissions from point source
in the reviewed counties.  Data from the 2002 NEI. 

County	NOx	SO2	PM2.5

Franklin County	7851.837	47612.6224	1005.612776

Jefferson County	9202.056	39281.1982	979.12496

St. Charles County	14691.27	46644.8862	1377.532697

St. Louis city	2014.306	6771.233	610.0265779

St. Louis County	10438.98	16689.3744	634.9402981

Madison County	10608.49	26745.56085	2601.379465

Monroe County	3.49	0.08046	27.57737963

Randolph County	22467.41	26295.97834	1766.661372

St. Clair County	368.7823	1540.66522	271.647678

Total TPY	77646.61	211581.5991	9274.503203

Missouri Total	44198.44	156999.3	4607.237

MO % Contribution	57%	74%	50%

Table 1.1:  2002 NEI TPY by pollutant.

In summary, EPA’s analysis of Factor 1 indicates that based on
emission levels and CES values, the Missouri counties are probable
contributors to the violating monitors and should remain candidates for
a 24-hour PM2.5 nonattainment designation.

 

Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the St. Louis Area based on data for
the 2005-2007 period.  A monitor’s design value indicates whether that
monitor attains a specified air quality standard. The 24-hour PM2.5
standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met. 

The 24-hour PM2.5 design values for counties in the St. Louis Area are
shown in Table 2.

County	State 

Recommended

 Nonattainment?	Design Values

2004-06

(µg/m3)

	Design Values

2005-07

(µg/m3)



Madison, IL*(Granite City)	Yes	39	39

Madison, IL (Alton)	Yes	34	36

St. Louis, MO*	No	32	34

St. Louis City, MO*	No	34	35

St. Clair, IL*	Yes	33	34

St. Charles, MO*	No	32	33

Jefferson, MO*	No	32	34

Randolph, IL**	Partial	27	30

Franklin, MO*	No	0***	0***

Monroe, IL*	Yes	0***	0***

*   Counties in bold represent those in the St. Louis nonattainment area
for the 1997 PM2.5 NAAQS

** Part of Randolph County, Illinois is in the 1997 PM2.5 NAAQS
nonattainment area 

*** There are no PM2.5 monitors in this county; therefore there are no
monitoring values for this county. 



Table 2.  Air Quality Data

Two locations in Madison County, Illinois have recent monitored
violations of the 24-hour PM2.5 standard as outlined in Table 2. Those
three locations are the Alton, Granite City Steel and VFW monitors. 
Therefore, Madison County, Illinois is included in the St. Louis
nonattainment area.  However, the absence of a violating monitor alone
is not a sufficient reason to eliminate counties as candidates for
nonattainment status.  Each county has been evaluated based on the
weight of evidence of the nine factors and other relevant information.

g/m3)	Nitrate (g/m3)	Carbon (g/m3)	Crustal (g/m3)	Total
(g/m3)	Sulfate Percent	Nitrate Percent	Carbon Percent	Crustal Percent

Total Concentration (Cold)	5.2	0	11.6	2.1	18.9	28	0	61	11

Regional Concentration (Cold)	3	0	2.5	1.3	6.8	44	0	37	19

Urban Increment (Cold)	2.2	0	9.1	0.8	12.1	18	0	75	7

Total Concentration (Warm)	28.4	0	8.2	1	37.7	75	0	22	3

Regional Concentration (Warm)	25.1	0	4.4	1.2	30.7	82	0	14	4

Urban Increment (Warm)	3.3	0	3.8	0	7.1	46	0	54	0

Total Concentration (Ann Avg)	3	2.7	9.2	1.1	16	19	17	58	7

Regional Concentration (Ann Avg)	2.1	0.8	2.8	0.8	6.5	32	12	43	12

Urban Increment (Ann Avg)	0.9	1.9	6.4	0.3	9.5	9	20	67	3

Table 2.1 Speciation data from the Chemical Speciation Network and the
IMPROVE monitoring network. 

Analysis of data in Table 2.1 indicates that the days with the highest
fine particle concentrations occur in both cool and warm seasons, and
the average chemical composition of the highest days is typically
characterized by high levels of carbon in the cold season, and high
levels of sulfates in the warm season.  Table 2.2 denotes all design
values in the St. Louis area for 2005-2007.  An evaluation of Table 2.2
indicates that 75% of the violations at the Alton monitor and 73% of the
violations at the Granite City monitor occur during the warm season.   

 	2nd&Mound	Margaretta	Blair	S. Broadway	Hunter	Sunset Hills	W. Alton
Arnold	Ste Genevieve	Swansea	13th&Tudor	Wood River	Alton	Granite City
VFW	Jerseyville	Houston- Bkgd	Season

1/28/2005	19.5	18.3	20.8	18.9	20.1	18.8	19.9	17.4	15.6	17.6	17.8	15.7	 
19.2	35.1	 	13.2	Cold

1/31/2005	45	41.5	46.1	46.9	43.6	43.8	38.5	41.3	38.3	37.9	 	18.6	 
39.6	 	 	 	Cold

2/1/2005	40.8	37.5	43	41.6	36.8	 	 	40.5	 	 	 	 	 	 	 	 	 
Cold

2/2/2005	46.7	43.4	47.5	48.3	44.2	 	 	46.3	 	 	 	 	 	 	 	10.1
 	Cold

2/3/2005	44.8	38.8	41.6	38.1	43.5	37.3	31.6	33.5	26	44.7	 	41.7	 	41.8
23	 	29.3	Cold

2/27/2005	39.2	38.1	39.7	38.4	36.9	37	32.7	36.7	33.2	35.3	39.5	 	35.5
37.9	36.3	32.8	31.1	Cold

3/17/2005	 	 	 	 	 	 	 	 	 	 	 	 	 	 	37	 	 	Cold

4/4/2005	 	24.8	 	29	24.3	 	 	23.9	 	 	 	 	 	 	38.2	 	 	Cold

6/24/2005	32.4	31.8	33.7	36.9	31.7	29.3	34.2	31.8	32.1	32.4	 	34.7	 
36	41.1	 	 	Warm

6/26/2005	40.8	 	40.3	39.5	 	 	 	40.5	 	 	 	 	 	 	 	 	 
Warm

6/27/2005	39.4	40	38.6	38.6	38.9	 	41.4	39.1	32.4	37.9	39.6	44.1	45.1
44.1	46.1	43.7	32.4	Warm

6/29/2005	39	 	37.4	38	 	 	 	39.6	 	 	 	 	 	 	 	 	 	Warm

7/23/2005	33.4	 	31.5	31.4	 	 	 	36.6	 	 	 	 	 	 	 	 	 
Warm

8/1/2005	45.3	 	41.9	41.5	 	 	 	45.8	 	 	 	 	 	 	 	 	 	Warm

8/2/2005	37.6	40.4	39.3	37	36.9	38.3	37.9	41.6	32.5	35.9	38.6	39.2	38.3
41.2	41.2	40.9	31.3	Warm

8/8/2005	41.6	38.4	38.7	38.4	39.7	36.2	38.2	37	33.2	 	40.4	41.2	39.4
44.7	41	37.2	34.3	Warm

8/9/2005	 	 	36.5	 	 	 	 	39.5	 	 	 	 	 	 	 	 	 	Warm

9/7/2005	39.8	36.4	36.4	36.3	34.5	36.2	34	37.8	36.1	33	 	38.8	35.4	45.8
42.1	33.1	32.1	Warm

9/10/2005	39.4	38.4	39.7	38	38.9	37.7	41.5	39.9	37.7	37	 	40.8	 	42.7
39.1	 	 	Warm

9/11/2005	41.8	 	41.5	39.3	 	 	 	41.7	 	 	 	 	 	 	 	 	 
Warm

9/13/2005	 	23.1	 	21.8	22.4	20.6	24.4	22.9	26	24.9	22	27.3	28.6	30.4
36	26.4	28	Warm

2/28/2006	31.8	30.5	32.8	29.3	27.7	23.3	27.2	22.6	15.3	19	29.2	28.3	25.8
40	27	29.5	13	Cold

4/29/2006	17.6	17.7	18	17.6	 	 	19.3	26.1	 	18.7	18.4	17.3	20.2	36.3
28	18.6	19.3	Warm

5/8/2006	20	19.5	20	18.1	19.2	16.6	20.7	18.2	17	 	 	21.9	 	25.1	37.2
 	 	Warm

7/20/2006	35.8	 	 	32.5	 	 	 	30.7	 	 	 	 	 	 	 	 	 	Warm

8/12/2006	29.6	30.8	29.2	31.7	31.6	 	28.1	32.4	34.4	28.1	 	25.1	 
39.9	32.9	 	 	Warm

8/13/2006	34.2	 	34.2	35.4	 	 	 	39.1	 	 	 	 	 	 	 	 	 
Warm

2/21/2007	37.9	0	33.8	30.7	21.2	 	24.5	22.3	 	26.8	 	 	 	 	 	 
 	Cold

5/24/2007	32.5	32.5	32.1	31.7	28.5	 	32.2	 	 	33.8	34.9	34.3	35.4
38.4	 	 	 	Warm

6/14/2007	36.3	36.3	 	35.8	36.1	 	34.1	35.2	 	32.9	 	31	 	 	 	 
 	Warm

6/17/2007	34.6	34.2	34.2	34.2	32.7	 	35	34.9	 	30.8	32.7	33.8	34.7
35.3	 	 	 	Warm

7/4/2007	20	 	21.7	22.5	16.8	 	17.5	45.7	 	9.6	 	 	 	 	 	 	 
Warm

8/1/2007	25.8	 	26.3	29.2	27	 	25.7	30.4	 	22	 	35	 	24.3	 	 	 
Warm

8/2/2007	47.9	 	47.1	41.3	41.9	 	39.4	41.1	 	 	 	 	 	 	 	 	 
Warm

8/3/2007	47.9	 	50.4	45	45.8	 	49.7	42.5	 	 	 	 	 	 	 	 	 
Warm

8/4/2007	33.8	 	34.2	32.9	29.3	 	33.9	32.6	 	28.4	32.5	38.4	33.4	36
 	 	 	Warm

9/21/2007	32.1	 	33.3	33.3	31.7	 	30.5	30.8	 	29.5	 	34.5	35	38.4	 
 	 	Warm

Table 2.3.  Air Quality Monitoring Data on Exceedance Days.

Note: Eligible monitors for providing design value data generally
include State and Local Air Monitoring Stations (SLAMS) at
population-oriented locations with an FRM monitor.  All data from
Special Purpose Monitors (SPM) using is eligible for comparison to the
relevant NAAQS, subject to the requirements given in the October 17,
2006 Revision to Ambient Air Monitoring Regulations (71 FR 61236).  All
monitors used to provide data must meet the monitor siting and
eligibility requirements given in 71 FR 61236 to 61328 in order to be
acceptable for comparison to the 24-hr PM2.5 NAAQS for designation
purposes.

In summary, EPA’s review of Factor 2 indicates that both local and
regional contributions to the violating monitors are likely.  Due to the
spatial separation of the Granite City monitor from the Alton monitor,
it is not likely that one source or a small group of localized sources
is exclusively impacting both monitors.  The speciation data also
indicates that sulfur and organic carbon sources are likely significant
contributors to the total mass on the filters.  Both of these PM2.5
precursor emissions are emitted in substantial quantities in upwind
Missouri areas.  Consequently, Factor 2 supports broader non-attainment
boundaries including all four of the nearby Missouri counties and St.
Louis City.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 3 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards.

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/sq mi)

Madison, IL*	Yes	   263,975 	357

St. Louis, MO*	No	1,002,258 	1914

St. Louis City, MO*	No	  352,572 	5334

St. Clair, IL*	Yes	   259,388 	385

St. Charles, MO*	No	   329,606 	557

Jefferson, MO*	No	   213,011 	321

Randolph, IL**	Partial	     33,116 	55

Franklin, MO*	No	     98,987 	107

Monroe, IL*	Yes	     31,289 	79

*   Counties in bold represent those in the St. Louis nonattainment area
for the 1997 PM2.5 NAAQS

** Part of Randolph County, Illinois is in the 1997 PM2.5 NAAQS
nonattainment area 



Table 3.  Population

A review of the population data for the bi-state metro area indicates
that Missouri counties/areas were consistently in the top three rankings
for both total population numbers and population density.  All Missouri
counties in the ranking for non-attainment consideration have
populations of over 90,000 people.  (Of the counties in Missouri,
Franklin County is the least populated with 98,987 people).  The total
population for Franklin County is approximately 3 times greater than
that of Monroe County, IL, which is the lowest population-ranked
Illinois County that was recommended for non-attainment by both EPA and
the state of Illinois.     

In summary, EPA’s review of Factor 3 indicates that 78% of the total
population in the bi-state area lives on the Missouri side of the St.
Louis area.  While, population and population density alone do not
provide absolute justification for determining nonattainment boundaries,
this data is indicative of population-based emissions.  Since these
highly populated Missouri areas are commonly upwind of the monitors on
high PM2.5 monitored days, these Missouri counties/areas remain
candidates for consideration in the nonattainment area designation.  

Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the St. Louis area the percent of total
commuters in each county who commute to other counties within the area
as well as the total Vehicle Miles Traveled (VMT) for each county in
millions of miles (see Table 4). A county with numerous commuters is
generally an integral part of an urban area and is likely contributing
to fine particle concentrations in the area.   The listing of counties
on Table 4 reflects a ranking based on the number of people commuting to
other counties. The counties that are in the nonattainment area for the
1997 PM2.5 NAAQS are shown in boldface.

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating counties

	Percent

Commuting to any violating counties

	Number Commuting into statistical area	Percent

Commuting into statistical area

St. Louis, MO*	No	14,165	3,800	1	493,070	99

St. Charles, MO*	No	3,185	740	0	147,420	99

St. Louis City*	No	3,638	1,250	1	139,280	99

Madison, IL*	Yes	2,318	75,490	62	119,590	98

St. Clair, IL*	Yes	3,019	7,040	6	110,870	98

Jefferson, MO*	No	2,241	490	1	96,860	99

Franklin, MO*	No	1,436	150	0	43,600	97

Monroe, IL*	Yes	359	420	3	13,560	95

Randolph, IL**	Partial	261	180	1	2,790	21

*   Counties in bold represent those in the St. Louis nonattainment area
for the 1997 PM2.5 NAAQS

** Part of Randolph County, Illinois is in the 1997 PM2.5 NAAQS
nonattainment area



Table 4.  Traffic and Commuting Patterns

Although the majority of the populous does not regularly travel directly
to/from the county monitoring violations (Madison County), the
population does routinely travel to/from and within the MSA as a whole. 
Specifically, the information in the table suggests a typical pattern of
high urban core traffic with the major interstate highways such as
Interstates 70, 270, 44, and 55 located in the Missouri portion of the
bi-state area.  The interstate highways outside the core urban area are
responsible for the majority of the VMT in those particular counties.  

Table 4 also reveals that Missouri counties account for 78% of the total
number of commuting miles into the MSA.  Of the Missouri areas: St.
Louis County and City of St. Louis and St. Charles rank as the top three
commuting areas in the bi-state metro area.  

In summary, EPA’s review of Factor 4 indicates that all of the
Missouri counties/areas rank high in terms of total VMT and are
therefore logical candidates for consideration in the nonattainment area
designation

Note:  The 2005 VMT data used for table 4 and 5 of the 9-factor analysis
have been derived using methodology such as that described in
"Documentation for the  2005 Mobile National Emissions Inventory,
Version 2," December 2008, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
ftp://ftp.epa.gov/EmisInventory/2005_nei/mobile_sector/documentation/200
5_mobile_nei_version_2_report.pdf

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in the St. Louis Area
as well as patterns of population and VMT growth.  A county with rapid
population or VMT growth is generally an integral part of an urban area
and likely to be contributing to fine particle concentrations in the
area.  

Table 5 below shows population, population growth, VMT and VMT growth
for counties that are included in the area.  Counties are listed in
descending order based on VMT growth between 1996 and 2005.

County	Population (2005)	Population % change (2000-05)	2005 VMT

(106 mi)	VMT

% change

(1996-2005)

Monroe, IL*	     31,289 	13 	        359 	          47 

St. Louis, MO*	 1,002,258 	-1	    14,165 	          33 

St. Charles, MO*	    329,606 	15 	     3,185 	          28 

Franklin, MO*	     98,987 	5 	     1,436 	          19 

St. Clair, IL*	    259,388 	1 	     3,019 	          13

Randolph, IL**	     33,116 	-2	        261 	            2 

Jefferson, MO*	    213,011 	7 	     2,241 	            1

St. Louis City, MO*	    352,572 	2 	     3,638 	          -8

Madison, IL*	    263,975 	2 	     2,318 	          -12 

*   Counties in bold represent those in the St. Louis nonattainment area
for the 1997 PM2.5 NAAQS

** Part of Randolph County, Illinois is in the 1997 PM2.5 NAAQS
nonattainment area 



Table 5.  Population and VMT Growth and Percent Change.

Data from Table 5 indicate that Missouri counties/areas occupied 4 of
the top 5 rankings in terms of total population and population growth
between the years 2000-2005.  In addition, Missouri counties/areas,
ranked in 3 out of the top 5 rankings in terms of VMT growth.   

As listed in Table 5, population growth above 5% occurred in the
following counties between 2000 and 2005:  St. Charles, Franklin, and
Jefferson counties in Missouri and Monroe County in Illinois. Only two
counties had a decline in population from 2000-2005 and those were St.
Louis County, Missouri and Randolph County, Illinois.  Madison County,
which is the county with the violating monitors, experienced a 12%
reduction in VMT between the years 2000 and 2005.  Also, it is notable
from Table 5 that no area had a concurrent drop in population and VMT. 
In other words, each area has experienced recent growth in at least one
or the other indices.  

In summary, EPA’s review of Factor 5 indicates that all areas in the
bi-state metro area experienced growth in either population or VMT and
sometimes both.  All of the Missouri areas consistently rank high in
terms of growth rates and growth patterns thereby supporting their
candidacy for non-attainment designations.

Factor 6:  Meteorology (weather/transport patterns)

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons (an
October-April “cold” season and a May-September “warm” season). 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values.

Table 6 shows the average prevailing surface wind directions for high
PM2.5 days by quadrant for each county in the St. Louis area.  These
data show that 24-hour PM2.5 concentrations are influenced by emissions
in all directions at various times, but these data also suggest that
emissions southeast and southwest of the violating monitor are more
likely to contribute to high PM2.5 concentrations than emissions from
other directions.

High days

	Prevailing Wind Direction (%)

	NW	SW	SE	NE

Days when only 1 monitor in St. Louis Area violated

2/18/04	0	76	4	4

1/28/05	0	0	96	4

9/13/05	0	59	16	4

2/28/06	0	0	13	42

4/29/06	0	0	96	0

5/8/06	0	29	44	0

8/12/06	0	0	48	28

Days when more than 1 monitor in St. Louis Area violated

9/3/04	4	12	50	8

9/12/04	14	0	41	0

1/31/05	9	0	4	40

2/3/05	17	55	0	0

2/27/05	4	0	58	12

6/24/05	0	54	24	10

6/27/05	0	60	12	0

8/2/05	0	8	54	0

8/8/05	0	12	55	0

9/10/05	0	36	32	0

Data based on EPA Wind Roses for St. Louis International Airport 

All percentages approximate. Due N, S, E, and W winds not included



Table 6.  Prevailing Wind Directions for High PM2.5 Days

For each air quality monitoring site, EPA developed a “pollution
rose” to understand the prevailing wind direction and wind speed on
the days with highest fine particle concentrations.  Figure 3 identifies
24-hour PM2.5 values by color; days exceeding 35 ug/m3 are denoted with
a red or black icon.  A dot indicates the day occurred in the warm
season; a triangle indicates the day occurred during the cool season. 
The center of the figure indicates the location of the air quality
monitoring site, and the location of the icon in relation to the center
indicates the direction from which the wind was blowing on that day.  An
icon that is close to the center indicates a low average wind speed on
that day.  Higher wind speeds are indicated when the icon is further
away from the center.  

Figure 3 Pollution Rose for Madison County, Illinois (County with
violating monitor in 2004-2006) 

As shown in the pollution rose in Figure 3, the average prevailing
surface wind direction for high PM2.5 days in Madison County, Illinois
(which is the county with the violating monitors) are from the southeast
and southwest.  However, the pollution rose shows that 24-hour PM2.5
concentrations can be influenced by emissions from any direction at
various times.  

In summary, EPA notes that the bulk of the Missouri portion of the St.
Louis bi-state area is located to the south-southwest of the two
violating monitors.  A review of the Factor 6 analysis indicates that
prevailing winds during PM2.5 episode are commonly from the southeast
and southwest.  Under these conditions, the majority of the Missouri
emissions for PM2.5 and precursors are upwind of the monitors during
these times and thus likely contributors to the total mass on the
filters.  Consequently, Factor 6 supports the position that Missouri
counties/areas are candidates for consideration in the nonattainment
area designation.  

Note:  The meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The St. Louis area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  

In summary, there are no physical barriers that would prevent Missouri
emissions from traveling downwind to the monitors on high PM2.5 episode
days.  Consequently, our review of Factor 7 supports the position that
all of the Missouri counties/areas are candidates for consideration in
the non-attainment area designation.  

Factor 8:  Jurisdictional boundaries (e.g., existing PM2.5 areas) 

In evaluating the jurisdictional boundary factor, EPA gave consideration
to areas that were already designated nonattainment in 2005 for
violating the 1997 fine particle standards.  Analysis of chemical
composition data in these areas indicates that the same components that
make up most of the PM2.5 mass in the area on an annual average basis
(such as sulfate and direct PM2.5 carbon)  also are key contributors to
the PM2.5 mass on many days exceeding the 24-hour PM2.5 standard in St.
Louis.  These data indicate that in metropolitan areas like St. Louis,
the same source categories that contribute to violations of the annual
standard also contribute to exceedances of the 24-hour standard.  

Most areas that were originally designated nonattainment for the PM2.5
standards still have not attained the standards this is true with the
St. Louis metro area, as well.  Thus, EPA has generally concluded that
counties that were designated as having emissions sources contributing
to fine particle concentrations which continue to exceed the 1997
standards also contribute to fine particle concentrations on the highest
days.  For this reason, EPA believes that for most existing
nonattainment areas, the nonattainment area for the 2006 24-hour
standard should be the same.  Consideration also should be given to
existing boundaries and organizations as they may facilitate air quality
planning and the implementation of control measures to attain the
standard.  Areas already designated as nonattainment represent important
boundaries for state air quality planning.

The existing nonattainment area for the 1997 PM2.5   NAAQS is as
follows:  

In Missouri- St. Charles, Franklin, Jefferson, St. Louis counties and
the City of St. Louis.

In Illinois- Madison, Monroe, St. Clair Counties and Baldwin Township,
Randolph County

The existing nonattainment area for the 1997 8-hour ozone NAAQS is as
follows:  

In  Missouri -St. Charles, Franklin, Jefferson, St. Louis counties and
the City of St. Louis.

In  Illinois -  Jersey, Madison, Monroe, and St. Clair Counties

In summary, EPA’s review of Factor 8 indicates that the St. Louis
metro area has yet to attain the annual PM2.5 standard.   Since, many of
the same pollutants and pollutant sources could be implicated in the 24
hour violations as they were for the annual violations, Factor 8
supports including all of the  Missouri counties/areas in the
non-attainment designation for the 24-hour standard and including those
relevant jurisdictional authorities in the development of the air
quality solution.

Factor 9:  Level of control of emission sources 

The emission estimates on Table 1 include any control strategies
implemented by the States in the St. Louis area before 2002 that may
influence emissions of any component of PM2.5 emissions (i.e., total
carbon, SO2, NOx, and crustal PM2.5).  In considering county-level
emissions, EPA considered 2002 emissions data from the National
Emissions Inventory.  

EPA recognizes that certain power plants or large sources of emissions
in this potential non-attainment area may have installed emission
controls or otherwise significantly reduced emissions since 2002 and
that this information may not be reflected in this analysis.  However,
EPA also notes that many of the controls that Missouri and Illinois will
likely rely upon to bring the St. Louis metro area back into attainment
with the annual PM2.5 standard have not yet been implemented and thus it
is difficult to determine what impact those reductions will have on the
monitors measuring violations of the 24 hour standard.

In summary, EPA’s review of Factor 9 is inconclusive.  In other words,
no clear conclusions can be drawn regarding the limitation of the
non-attainment boundaries for the St. Louis metro area based on these
data.  

Conclusion

After review of the nine factors for the four counties and the City of
St. Louis (including five counties in Illinois) EPA is designating the
City of St. Louis, St. Louis County, Franklin County, Jefferson County
and St. Charles County in Missouri as nonattainment for the 2006 24-hour
PM2.5 standard.  Although the violating monitors are located in Madison
County, Illinois, the four Missouri counties and city described above
are probable contributors of PM2.5 to the violating monitors based on
analysis of all the factors and analytic tools.  Information for each of
these Missouri entities is contained in the above discussion of the nine
factors.  Conclusions with respect to the entire area in Missouri which
we are designating nonattainment are as follows:

Surface wind direction for monitored days with high PM2.5 concentrations
in Madison County, Illinois is from the southeast-southwest.  This means
that the majority of the Missouri portion of the bi-state area is
located upwind of the violating monitors on a significant number of high
PM2.5, concentration days.

Missouri counties/areas contribute the majority of PM2.5 and PM2.5
precursor emissions to the bi-state metro area.  Specifically,
approximately 50% of the total tons per year (tpy) of direct PM2.5,
approximately 57% of the total tpy of NOx, and approximately 74% of the
total tpy of SO2 emitted in the bi-state area.

70% or greater of the exceedance days occur during the warm season and
are influenced by SO2.  Missouri counties account for 74% of the SO2
emissions in the bi-state area.   

78% of the total population and their associated emissions in the
bi-state area are located on the Missouri side of the St. Louis bi-state
area. While, population and population density alone do not provide
absolute justification for determining non-attainment boundaries, this
data is indicative of population-based emissions.  

Due to the spatial separation of the Granite city monitor from the Alton
monitor, it is not likely that one source or a small group of localized
sources is exclusively impacting both monitors.  The speciation data
also indicates that sulfur and organic carbon sources are likely
significant contributors to the total mass on the filters.  Both of
these PM2.5 precursor emissions are emitted in substantial quantities in
upwind Missouri areas. 

All areas in the bi-state metro area experienced growth in either
population or VMT and sometimes both in recent years.  However, Missouri
areas consistently ranked among the highest in terms of growth rates.  

There are no physical barriers that would prevent Missouri emissions
from traveling downwind to the Madison County monitors on high PM2.5
episode days.

The St. Louis metro area has yet to attain the annual PM PM2.5standard. 
Speciation data and pollution rose data indicate that many of the same
pollutants and pollutant sources and source regions that were implicated
in the violations of the annual standard could be implicated in the 24
hour violations, as well

The area in Missouri which EPA is including as non-attainment is already
part of a nonattainment area for existing Ozone and annual
PM2.5standards.  Therefore, the boundary established by EPA is
consistent with established jurisdictional boundaries for air quality
and transportation planning for the previously mentioned ambient air
quality standards.

In conclusion, the above analysis shows that Missouri counties/areas
have significant PM2.5 and precursor emissions and substantial growth
rates when compared to the rest of the metro area.  Data also show that
Missouri areas are commonly upwind of the violating monitors on high
PM2.5 episode days.  The air quality monitoring, including the
speciation data analysis, the level of control analysis, and the
geographic/topographic analysis, indicate that emissions contributions
from Missouri counties/areas cannot be ruled out.  

None of the analyses conducted by Missouri or EPA under the 9 Factor
approach led to a conclusive determination that Missouri counties/areas
were not contributing to the filter mass at any of the Monroe County,
Illinois violating monitors contribute to the violating monitors.

Based on this review, EPA is designating the Missouri Counties of
Franklin, Jefferson, St. Charles and St. Louis, and the City of St.
Louis as non-attainment for the 24 hour PM2.5 standard.

Additional information regarding responses to specific State comments
can be found in EPA's Response to State Comments document at   HYPERLINK
"http://www.epa.gov/pmdesignations/2006standards/tech.htm" 
http://www.epa.gov/pmdesignations/2006standards/tech.htm .  

Attachment 2

Description of the Contributing Emissions Score

The CES is a metric that takes into consideration emissions data,
meteorological data, and air quality monitoring information to provide a
relative ranking of counties in and near an area.  Using this
methodology, scores were developed for each county in and around the
relevant metro area.  The county with the highest contribution potential
was assigned a score of 100, and other county scores were adjusted in
relation to the highest county.  The CES represents the relative maximum
influence that emissions in that county have on a violating county.  The
CES, which reflects consideration of multiple factors, should be
considered in evaluating the weight of evidence supporting designation
decisions for each area.

The CES for each county was derived by incorporating the following
significant information and variables that impact PM2.5 transport:

	Major PM2.5 components:  total carbon (organic carbon (OC) and
elemental carbon (EC)), SO2, NOx, and inorganic particles (crustal).

	PM2.5 emissions for the highest (generally top 5%) PM2.5 emission
days (herein called “high days”) for each of two seasons, cold
(Oct-Apr) and warm (May-Sept)

	Meteorology on high days using the NOAA HYSPLIT model for
determining trajectories of air masses for specified days

	The “urban increment” of a violating monitor, which is the urban
PM2.5 concentration that is in addition to a regional background PM2.5
concentration, determined for each PM2.5 component

	Distance from each potentially contributing county to a violating
county or counties

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CES can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

 EPA designated nonattainment areas for the 1997 fine particle standards
in 2005.  In 2006, the 24-hour PM2.5 standard was revised from 65
micrograms per cubic meter (average of 98th percentile values for 3
consecutive years) to 35 micrograms per cubic meter; the level of the
annual standard for PM2.5 remained unchanged at 15 micrograms per cubic
meter (average of annual averages for 3 consecutive years).  

 Under Missouri law, the City of St. Louis is not contained within any
county and is therefore not a portion of a county. 

 As stated previously, the VFW monitor recorded violations for
2004-2006, but not for 2005-2007.

 PAGE   

 PAGE   11 

Counties labeled in bold reflect NAAs under 1997 NAAQS

St. Louis, MO-IL

