Draft Technical Support Document

MISSOURI

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 “unclassifiable”, “attainment”, or “nonattainment” 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 counties or 

portions of counties (or Indian Country) in Missouri that EPA intends to initially designate 

“nonattainment” based on monitored violations. 

Table 1. Nonattainment Area Designations for Missouri

Area 

Missouri’s

Recommendation of 

Areas/Counties

EPA’s Intended Designated 

Nonattainment Areas/Counties

Jackson County

 Jackson County (partial)

portion of Jackson 

County

Nonattainment

Jefferson County

 Jefferson County (partial)

portion Jefferson 

County

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 attained when 

the 3-year average of the 99th percentile of the daily maximum 1-hour average concentration at 

each monitor in an area does not exceed 75 ppb. 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.
EPA’s SO2 Designation Approach

Section 107(d) of the CAA requires that not later than 1 year after promulgation of a new or 

revised NAAQS, state Governors must submit their recommendations for designations and 

boundaries to EPA. This deadline was in June, 2011. Section 107(d) also requires EPA to 

provide a notification to states of no less than 120-days prior to promulgating an initial area 

designation that is a modification of a state’s recommendation. EPA has reviewed the State’s 

recommendations and has notified the State Commissioner through letter signed by the Regional 

Administrator of any intended modifications. [While language in section 107 specifically 

addresses states, we intend to follow the same process for tribes, pursuant to section 301(d) of 

the CAA and Tribal Authority Rule (40 CFR Part 49). Therefore, we intend to designate areas of 

Indian Country, in consultation with the tribes, on the same schedule as state designations.] If a 

State or Tribe did not submit designation recommendations, EPA will promulgate the 

designations that it deems appropriate. If a state or Tribe disagrees with EPA’s intended area 

designations, they have 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 intends to 

evaluate 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 relevant to 

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

The March 24, 2011, memo recommended that area boundaries be defaulted to the county 

boundary unless additional provided 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 a default county boundary.

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

by the states and/or tribes 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 a State or Tribe has recommended to EPA be 

designated as nonattainment.

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 

maximum 1-hour average concentrations

5) Design Value – a statistic that describes the air quality status of a given area relative to the 

level of the NAAQS.

Nonattainment Designations

Introduction

This technical analysis for the State of Missouri identifies the counties with a monitor(s) that 

violate the 2010 SO2 NAAQS based on 2009-2011 as well as 2008-2010 data, and evaluates 

nearby counties for contributions to SO2 concentrations in the area. In Missouri’s designation 

recommendation letter to EPA, dated July 11, 2011, Sara Parker Pauley, Director of the Missouri 

Department of Natural Resources (MDNR), recommended that portions of Greene, Jackson and 

Jefferson counties be designated as nonattainment for the 2010 SO2 NAAQS based on monitored 

air quality data from 2007-2009. Additionally, MDNR has recently certified the most recent 

data from the Greene County monitors for the year ending in 2012, and informed EPA Region 7 

(in a letter dated January 11, 2013) that they intend to revise their nonattainment 

recommendations to not include Greene County, MO because the monitors in Greene County are 

no longer recording a violation of the 2010 1-hr SO2 NAAQS. EPA agrees that the most recent 

certified air quality monitoring data for Greene County indicate that the monitors are no longer 

recording violations of the 2010 1-hr SO2 NAAQS, and therefore is not including Greene County 

as part of the technical analysis for areas with violating monitors for this NAAQS.

Based on EPA’s technical analysis, EPA intends to designate two areas as nonattainment 

(Table 1). 

The Jackson County, MO Nonattainment Area includes a part of Jackson County which consists 

of the area North of I-70/I-670, West of I-435, East of the state line with Kansas and South of the 

Missouri River.

The Jefferson County, MO Nonattainment Area includes a part of Jefferson County which

consists of both Herculaneum and Festus townships and those portions of Valmeyer and Selma 

townships directly to the East that separate Herculaneum and Festus townships from the 

Mississippi River.

EPA has evaluated these counties and nearby counties based on the weight of evidence of the 

factors recommended in the March 24, 2011, issued EPA guidance.

The 5 factors were used to analyze the nonattainment areas for 1-hour SO2 designations:
1. Air quality data. We reviewed SO2 air quality monitoring data from EPA’s Air Trends 

website (see http://www.epa.gov/airtrends/values.html), including the design value 

calculated for each monitor in the area for the most recent 3-year period. A monitor’s 

design value indicates whether that monitor attains a specified air quality standard. The 

2010 SO2 NAAQS is met at a monitoring site when the identified design value is valid 

and less than or equal to 75 ppb as described in Appendix T of 40 CFR part 50. An 

ambient air monitor whose valid design value exceeds 75 ppb, as described in Appendix 

T of 40 CFR part 50 is deemed a violating monitor. A design value is only valid if 

minimum data completeness criteria are met. An SO2 design value that meets the 

NAAQS is generally considered valid if it encompasses 3 years of complete data. A year 

is complete when all 4 quarters are complete. A quarter is complete when 75% of the 

days are complete. A day is complete when it has 75% of its hours. Data substitution 

tests are described in Appendix T of 40 CFR part 50. Areas where monitoring data 

indicate a violation of the 1-hour, 75 ppb primary SO2 standard will be designated as 

nonattainment. Source-oriented modeling may also be used to assess air quality in a 

particular location. Attachment 3 of the March 24, 2011 EPA memo provides further 

guidance on using refined dispersion modeling for this type of assessment.

2. Emissions and emissions-related data (location of sources and potential contribution to 

ambient SO2 concentrations). We reviewed data from the 2008 National Emissions 

Inventory (NEI), version 2 (NEI08V2), which was the most current version of the 

national inventory available in 2011 when these data were compiled for the designations 

process, (see http://www.epa.gov/ttn/chief/net/2008inventory.html) or other relevant 

sources of data, such as state inventories or inventories from other federal sources. EPA 

recognizes that there might be no new information on any changes in emissions that may 

have occurred after 2008, but would consider more recent years if available. For 

example, certain large sources of emissions in or near an area may have installed 

emission controls or otherwise significantly reduced emissions since 2008. Two source 

categories from the 2008 NEI were examined: the point source inventory and the 

nonpoint source inventory. Generally, the point source inventory represents the bulk of 

the SO2 emissions in Region 7.

3. Meteorology (weather/transport patterns). We evaluated meteorological data to help 

determine how weather conditions, including wind speed and direction, affect the plume 

of sources contributing to ambient SO2 concentrations. The National Weather Service 

maintains surface and upper air monitoring sites across the United States. Automated 

Surface Observing System (ASOS) (http://www.weather.gov/asos) sites collect hourly 

averaged wind measurements including wind direction and wind speed. 

4. Geography/topography (mountain ranges or other air basin boundaries). We examined 

the physical features of the land that might affect the distribution of SO2 over an area. 

River Valleys, Escarpments, or other physical features may affect the distribution of 

emissions, and may help define boundaries. Satellite images depicting River Valleys and 

point sources were constructed and evaluated to determine the effects of the topography 

on point source emissions.
5. Jurisdictional boundaries (e.g., counties, air districts, pre-existing nonattainment areas, 

reservations, metropolitan planning organizations). Once the geographic area associated 

with the area violating the SO2 standard and the nearby area contributing to violations 

were determined, we considered existing jurisdictional boundaries for the purposes of 

providing a clearly defined legal boundary for carrying out the air quality planning and 

enforcement functions for the nonattainment area. If an existing jurisdictional boundary 

is used to help define the nonattainment area, it encompasses all of the area that has been 

identified as meeting the nonattainment definition. These existing boundaries may 

include an existing nonattainment or maintenance area boundary, a county or township 

boundary, a metropolitan area boundary, an air management district, or an urban planning 

boundary established for coordinating business development or transportation activities. 

Where existing jurisdictional boundaries are not adequate to describe the nonattainment 

area, other clearly defined and permanent landmarks or geographic coordinates are used.

MDNR recommended a partial county boundary for all their nonattainment area boundaries, 

which was not the default boundary as per EPA’s March 24, 2011 designations guidance. EPA 

evaluated MDNRs recommendations and analysis in assessing whether a partial county boundary 

was warranted considering the analysis supplied. We utilized the March 24, 2011 designation 

guidance and the five factor analysis described above to assess whether MDNRs nonattainment 

boundary recommendations met the criteria outlined in the March 2011 guidance. 
Intended Nonattainment Designation 

Technical Analysis for Jackson County, Missouri

Introduction 

This technical analysis for Jackson County, Missouri identifies the part of the county with a 

monitor that violates the 2010 SO2 NAAQS based on 2009-2011 data and evaluates sources in 

nearby counties in Missouri and the state of Kansas for contributions to the violating monitor in 

the Jackson county area. EPA has evaluated this county and nearby counties based on the weight 

of evidence of the factors recommended in the March 24, 2011, issued EPA guidance. Figure 8

depicts the nonattainment boundary and area (shaded in green) that EPA intends to finalize for 

Jackson County, MO. The figure also depicts the two monitors currently operating in the area (1 

monitor is recording design values exceeding the primary SO2 NAAQS while the other records 

design value attaining the NAAQS), as well as SO2 sources emitting greater than 1000 tons of 

SO2 per year.

Figure 8: Map of Intended Nonattainment Area for Jackson County, MO

Figure 8 below depicts The Kansas City Metro Area with the state of Kansas shaded, SO2

emitting sources in the NEI, the two monitoring locations (Troost in MO which is the violating 

monitor, and JFK on the KS side), and major highways. 
Figure 8: KC Metro Area Emission Sources and Monitoring Sites 

In July 2011, the Missouri Department of Natural Resource (MDNR) recommended that a 

portion of Jackson County, Missouri be designated as nonattainment for the 2010 SO2 NAAQS 

based on monitored air quality data from 2007-2009.

Figure 9 depicts the Kansas City Metro Area showing the major sources of SO2 emissions, 

monitoring locations, major roads, and the MDNR recommended nonattainment area for Jackson 

County, MO (shaded), which contains the violating monitor represented by a green star.
Figure 9: Missouri’s Recommended Nonattainment Area for Jackson County

Based on EPA's technical analysis described below, EPA is intending to designate a portion of 

Jackson County, Missouri as nonattainment for the 2010 SO2 NAAQS based upon currently 

available information.
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 both Jackson County, Missouri and Wyandotte County, 

Kansas (and the surrounding area) based on data for the 2009-2011 period. 

MDNR’s recommendation was based on data collected from monitor(s) located in the Kansas 

City, Missouri metropolitan area meeting the specifications of a Federal Reference Method 

(FRM) or Federal Equivalent Method (FEM) in accordance with 40 CFR Part 53 (see letter from 

Sara Parker Pauley Director of MDNR to Karl Brooks Region Administrator EPA Region 7 

dated July 19, 2011) .

The 3 year design values (’09-’11) for the monitors in Jackson County, MO and Wyandotte 

County, KS, are shown in Table 6.

Table 6: Air Quality Data for Nonattainment Designation in Jackson County, Missouri

County

State

Recommended

Nonattainment?

Monitor Name Monitor Air Quality

System ID Monitor Location

3 yr SO2 Design 

Value (ppb)

’09 thru ‘11 

Jackson, MO Yes Troost 290950034 Jackson Co, MO 159

Wyandotte, 

KS No JFK Wyandotte Co, KS 47

Jackson County, Missouri’s Troost monitor shows a violation of the 2010 SO2 primary NAAQS. 

Therefore, some area in Jackson County must be designated nonattainment. The absence of a 

violating monitor alone is not a sufficient reason to eliminate nearby counties as candidates for 

inclusion in a nonattainment area. Each area has been evaluated based on the weight of evidence 

of the five factors and other relevant information. 

Of the two monitors in Kansas City Metro Area, only the Troost monitor has a design value in 

excess of the 1-hr SO2 primary NAAQS. Due to the comparatively lower concentrations of 

ambient SO2 recorded at the JFK monitor in KS (and the proximity of the JFK monitor to the two 

highest emitting sources in Wyandotte Co, KS, as well as the alignment of these sources with the 

Veolia/Trigen source in MO, and the Troost monitor) it is believed that the source responsible 

for the monitored reading in excess of the NAAQS at the Troost monitor is the Veolia/Trigen 

source located in Jackson County, Missouri, and is encompassed by the nonattainment boundary 

recommended by MDNR. Veolia/Trigen provides steam and heat to the downtown area of 

Kansas City, Missouri, and currently operates with no pollution control equipment to capture or 

reduce its SO2 emissions. Based on the information submitted to EPA by MDNR, and a careful 

evaluation of: 1) the location of monitors recording exceedances in the area; 2) the weather 

conditions during the times the area monitor[s] recorded exceedances (and/or high recorded 

measurements); and, 3) the location and size of sources emitting SO2 in and around the Kansas 

City Metro Area monitors for the years 2007 thru 2011, EPA believes the boundary 

recommended by MDNR for Jackson County, MO properly bounds the area of the county (and 

the source primarily responsible for the area) not attaining the 2010 SO2 primary NAAQS. 
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. For this factor, 

EPA evaluated county level emissions data for SO2 and any growth in SO2 emitting activities 

since the date represented by those emissions data.

Emissions 

The Kansas City Metropolitan Area (KC Metro Area) is composed of five counties in two states. 

The predominant counties of the metro area are Jackson County, MO and Wyandotte County, KS 

which lie in the heart of the area. In Jackson County, MO there are 66 NEI listed point sources 

of SO2. In Wyandotte County, KS there are 21 NEI listed point sources of SO2. The majority of 

the NEI listed sources in both counties emit much less than 100 tons of SO2 per year. The largest 

sources of SO2 in Wyandotte, KS are the Nearman and Quindaro Power Plants operated by the 

Board of Public Utilities. In the entire KC Metro Area there are 8 sources of SO2 that emit over 

1000 tons of per year, and are the focus of the analysis of Jackson County, MO. Of all the 

sources in KC Metro Area emitting over 1000 tons per year all but one are located on the 

Missouri River, with the remaining facility being located on the Kansas River.

It is important to note the location of the 2nd largest source of SO2 emissions in the KC Metro 

Area which is the Grand Avenue (Veolia/Trigen) steam plant located approximately 3.2 miles

upwind from the violating Troost monitor in Jackson County, MO, and the two largest sources of 

SO2 emissions in Wyandotte County, KS, which are closer to the JFK monitor located in 

Wyandotte County, KS. BPU-Quindaro is approximately 1.3 miles from the non-violating 

Wyandotte County, KS monitor and 4.9 miles from the violating Jackson County, MO monitor.

BPU-Nearman is approximately 4.8 miles from the non-violating Wyandotte County, KS 

monitor, and 8.2 miles from the violating Jackson County, MO monitor. Additionally, the two 

sources in Kansas and the Veolia/Trigen source in MO are fairly well aligned with the Troost 

monitor. This alignment of the KS sources, the Veolia/Trigen source in MO and Troost monitor 

obfuscates the limited contribution from the KS sources on the violating monitor in Jackson 

County, MO from the overwhelming contribution of the Trigen source on the monitor in MO. 

To assess the contribution of the KS sources on the violating monitor in MO, we prepared and 

analyzed back trajectories for the times in which both monitors (the MO Troost monitor and the 

KS JFK monitor) violated the standard or recorded high measurements. We found that both 

monitor’s design values are being driven by the emissions from the Veolia/Trigen source in 

Jackson County, MO. The trajectories for the JFK monitor in KS show that when the monitor 

recorded its highest readings the winds are out of the east carrying emissions from the 

Veolia/Trigen to the monitor. Similarly, when the Troost monitor in MO records violations, the 

winds are out of the northwest carrying emissions from the Veolia/Trigen source to the monitor 

driving the design value. Figure 10 shows the back trajectories analyzed for the 1-hr violations 

recorded at both the Troost and JFK monitors. The blue lines represent individual trajectories 

over an 8 hr period prior to the violation being recorded, and the red lines represent composites 

of all the blue lines for each monitor. These trajectories demonstrate that the Grand Avenue -

Veolia/Trigen source is consistently the source most responsible for the 1-hr violations recorded 
at both the Troost monitor in MO, and the highest hourly readings recorded at the JFK monitor in 

KS. 

Figure 10: Backtrajectories for the both the Troost and JFK monitors

Overall SO2 emissions in Kansas City Metro Area were down about 35% in the year 2009 from 

2007. This reduction was primarily due to scrubber controls installed at Kansas City Power & 

Light’s (KCP&L) Iatan Plant in Platte County, MO and to a lesser degree related to reductions in 

electricity demand that was a result of a mild winter and summer seasons between the years 2008 

and 2009. The largest source of SO2 emissions in Jackson County, MO is the Sibley power plant 

operated by KCP&L, however our analysis described above demonstrates the lack of significant 

impact in the direction of the Sibley source, likely due to the fact that the prevailing winds rarely 

blow from east to west and the plant is located approximately 20 miles east of the Troost 

monitor. The same rational holds for the other sources of SO2 in the area (Hawthorn, Blue 

Valley and Clay County Power plants) these sources are east of the violating Troost monitor (i.e., 
against the prevailing winds) and at a distance that limits their impact on the concentrations 

being detected at the Troost monitor. There are also a significant number of minor sources 

scattered throughout the city limits of Kansas City and Independence, Missouri; however these 

sources have emissions below 10tpy.

EPA recognizes that there may be important new information on emissions levels for the period 

after 2009, and would consider more recent information if available. MDNR provided emissions 

information for large sources of SO2 in an around the three counties recommended for

nonattainment for the years 2007 through 2009. During our review of MDNR’s boundary 

recommendation, we relied on the 2008 National Emissions Inventory (NEI) as well as the 

emissions data supplied by the Missouri for the year 2009. The NEI is updated every three years 

(e.g., 2008, 2011, etc.) and provides a snapshot of the emissions from the identified sources for 

the update year. Additional emissions information was provided by the state of Missouri from 

state emission databases. We do not have emissions data on Quindaro and Nearman for the year 

2007. The emission data for Jackson County and the KC area we relied on during our review is 

included in table 7 below. Table 7 shows total emissions of SO2 (given in tons per year) for 

violating and potentially contributing counties in and around Jackson County, including 

Wyandotte County, KS for all sources emitting greater than 1000 tons of SO2 per year. 

Emissions Controls

The emissions data used by EPA in this technical analysis and provided below represent real 

emissions levels occurring at the sources and thus take into account any control strategies 

implemented on the stationary sources in Jackson County up to and including the year 2009. 

EPA received additional information on emissions reductions resulting from state and federally 

enforceable controls put into place up to 2010.
Table 7: Large Sources of SO2 Emissions in and around Jackson County, Missouri

SO2 emissions (tpy)

Facility 2007 2008 2009

Jackson County, MO

KCP&L –

Sibley 11,796 9,181 11,787

Veolia –

Grand Ave 6,077 6,295 7,201

IP&L – Blue 

Valley 9,185 10,658 6,177

KCP&L –

Hawthorn 1,923 1,725 2,017

Platte County, MO

KCP&LIataan 14,290 15,077 1,923

Clay County, MO

IP&LMissouri City 5,040 2,952 920

MO Total 48,311 45,528 30,569

Wyandotte County, KS

BPU –

Nearman NA 5,992 5,923

BPUQuindaro NA 3,901 3,612

KS Total NA 9,893 9,535

Area Total 48,311* 55,421 39,569

*The total emissions in 2007 for the KC area does not include sources in Wyandotte, County 

KS and does not represent an increase in emissions between 2007 and 2008.

Also included in MDNR’s boundary recommendation technical support document is an 

assessment of the impact of federal regulations scheduled to become enforceable in the future. 

This information is not relevant to EPA’s nonattainment boundary analysis. MDNR believes 

that a significant reduction of regional emissions of SO2 will be realized as a result of particular 

federal regulatory actions, and may result in emission reductions at sources impacting the areas 

currently not attaining the 2010 1 hr primary SO2 NAAQS. These regulations are not limited to,

but may include: 1) the Transport Rule (aka: Cross-State Air Pollution Rule (CSAPR)) finalized 

on June 6, 2011; 2) the National Emission Standards for Hazardous Air Pollutants (NESHAPs) 

for Area Sources: Commercial Industrial and Institutional Boilers (finalized December 2, 2011); 

and, 3) the Utility MATS (finalized December 21, 2011). Specific reductions associated with 

these rules are unknown as the compliance dates have not passed and some of these rules are 

subject to litigation. In addition, EPA notes that on Thursday, January 24, the DC Circuit Court 

of Appeals denied the EPA’s request for an en banc rehearing of its August Homer City decision 

vacating the Cross-State Air Pollution Rule. Currently, the 2005 Clean Air Interstate Rule 

remains in effect in states. Emissions reductions from the Clean Air Interstates Rule will assist 

many areas in attaining the SO2 NAAQS. For those areas where more work is needed, state and 
local governments will develop and implement plans to reduce emissions from sources of 

significant SO2 emissions through enforceable emissions limits.

 

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 sources and the appropriate extent of the nonattainment area boundary. For this 

factor, EPA considered recent hourly or sub-hourly meteorological data from the metrological 

site(s) nearest to the violating monitor to determine which wind vectors were associated with 1-

hour SO2 exceedances. For the nonattainment areas recommended by MDNR, the general 

meteorological data used in MDNR’s analysis were from the years 2005 and 2007. Additionally, 

MDNR utilized highly specific meteorological data for the days and hours proceeding high 

monitored readings recorded by the violating monitor in Jackson County (this data used for 

HYSPLIT modeling and analysis discussed more fully in a later section). The meteorological 

stations this data was collected from are operated by National Weather Service (NWS) for the 

purposes of cataloging representative weather conditions in the area. The NWS metrological 

stations used in both EPA’s and MDNR’s analysis are the stations in closest proximity to the 

violating monitor. In the case of Jackson County, Missouri, the metrological station is 2.8 km 

(1.74 miles) from the Troost monitor. EPA believes that the meteorological analysis and data 

used by MDNR properly represents the meteorological conditions that impact SO2

concentrations in the area of the violating monitor. In our review of MDNR’s analysis, EPA 

used the same meteorological station as MDNR for each of the monitors, but considered 

differing years to assess the general conditions that exist in Jackson County. In this analysis, we 

reviewed MDNR’s conclusions:

MDNR’s Assessment of wind conditions in Missouri and Jackson County concludes that winds 

in the state of Missouri predominantly come from the Southeast and Northwest, and that, in 

general, winds from the Northeast are rare throughout the year. MDNR concludes that the 

greatest wind direction deviation in the county from the predominant wind pattern in the state 

routinely occurs in the 3rd quarter of the year and is representative when the winds predominantly 

come out of the Southwest.

Figure 11 shows a map of the meteorological data location with respect to the SO2 monitors

(small purple balloons), large SO2 sources (large blue balloons) in the Jackson County, Missouri 

area, as well as the MDNR recommended nonattainment boundary outlined in red. Additionally. 

the metrological station is located on the map and represented as small white balloon.
Figure 11: Metrological Station, Monitor and Large Sources of SO2

EPA’s qualitative assessment of the quarterly wind rose analysis supplied by MDNR concludes 

that winds, monitored in Jackson Co, MO, blow with the greatest velocity and frequency out of 

the East - Northeast and to a lesser extent from the South, Southeast and Southwest. Please see 

the docket to review MDNR’s wind rose analysis submitted to EPA. Due to this wind pattern 

sources North and South of the monitor (and within a distance that the source could impact the 

monitor) would have the greatest effect on the SO2 concentrations recorded by the monitor on a

regular basis. In the case of the Jackson County monitor this would suggest that the Veolia 

steam plant is the SO2 source in the area that is responsible for the SO2 concentrations recorded 

at the Troost monitor and ambient SO2 conditions existing in west central Jackson County, 

Missouri. As a result of the variation in elevations surrounding the confluence of the Kansas and

Missouri River channels and the location of the Troost monitor in close proximity to the 

confluence, sources not in the immediate vicinity of the violating monitor may have a reduced 

impact due to the effects of wind channeling. 

EPA performed a wind rose analysis for the years 2009 through 2011 (Figure 13) the results 

show that winds in Jackson County predominantly blow out of the South-Southwest with the 

greatest frequency and intensity. However, winds also blow regularly out of the Northwest with
sufficient frequency and intensity to impact the monitor on a regular basis. This is not 

inconsistent with the results of MDNR’s analysis for the year 2005. The result suggest that 

sources to the South would have a greater impact on the monitor, but there are no sources to the 

South of the violating monitor with sufficient size or within a sufficient range to impact the 

concentrations being recorded at the monitor. This leaves only the Veolia source which is located 

northwest of the monitor as the source impacting the monitor. The winds out of the Northwest 

(i.e., Veolia) would blow emissions from this source in a direct line to the monitor and 

considering the source’s size and proximity to the monitor, the impact would be substantial.

Figure 13: EPA Wind Rose Analysis 2009-2011
MDNR submitted back trajectory analysis derived from the Hybrid Single Particle Lagrangian 

Integrated Trajectory (HYSPLIT) model. Back trajectory modeling assesses the path an air 

parcel travels during the previous 24 hours to arrive at particular time and location. For this 

modeling MDNR used meteorological data corresponding to the 4 highest monitored readings at 

the violating monitors in Jackson County, MO. MDNR submitted to EPA back trajectory 

analysis derived from the HYSPLIT model. Back trajectory modeling assesses the path an air 

parcel travels during the previous 24 hours to arrive at particular time and location. For this 

modeling MDNR used meteorological data corresponding to the 4 highest hourly monitored 

readings recorded at the violating monitor in Jackson County, MO. A summary of the analysis 

results from MDNR is discussed below. Please see the docket to review MDNR’s HYPLIT plots 

for Jackson County, MO which is summarized below. 

– Jackson County, Missouri HYSPLIT Analysis Summary

MDNR performed 12 composite trajectory analyses on days of recorded violations at the 

violating Troost Monitor. Eight of these trajectories come out of the northwest from the 

direction of the predominate source in the area (Grand Avenue/Veolia/Trigen). Those eight 

trajectories also align with two additional sources in Kansas (Nearman, and Quindaro plants) but 

due to the distance of these plants from the violating monitor, we are uncertain what contribution 

they make to the concentrations observed at the Troost monitor. We note that the four remaining 

trajectories originate from vectors which would not be conducive to KS emission contributions 

to the violating Troost monitor. In analyzing these trajectories, the Veolia/Trigen source remains 

the primary source of the violations based on the MO HYSPLIT analysis. 

In addition to the above information, EPA notes two important points. First, EPA conducted a 

site-specific SO2 source spatial observation analysis (found in the docket) that indicates the 

Veolia/Trigen plant is most likely to have the predominant impact on the violating Troost 

monitor due to its close proximity. Second, a review of the back trajectories for the high 

recorded concentration days at the Wyandotte County, KS monitor shows that on these “high” 

SO2 days, the back trajectory most frequently implicates the MO Veolia/Trigen plant as the 

culpable, predominant contributor to these concentrations. Therefore, we conclude that (based 

on the MO HYSPLIT and EPA observations) the contribution of the Veolia/Trigen plant’s 

emissions on the “high” value days at the nonviolating JFK monitor in KS, and the contribution 

of the Veolia/Trigen plant’s emissions on the exceedance days at the violating Troost monitor are 

the predominant contributions compared to all other SO2 sources in the area.

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

In general, the Northern part of Missouri consists of open plains and contains few features that 

impede, restrict, or channel air speed and direction. The major geological features that can have 

small localized effects on wind direction and inversion are the Mississippi and Missouri River 

valleys. Generally, the effects of the river valleys are to channel localized air movement in a 

North-South (Mississippi) or East-West (Missouri) wind direction. The effect is not expected to 

affect the concentrations of SO2 observed at Jackson County monitoring location directly, but 
may result in limiting a sources impact on the Troost monitor. This is because of the location of 

the river valley relative to the location of the violating monitor in Jackson County, MO.

Figure 14 is a satellite image of the KC metro Area showing a 12 mile radius around the 

violating monitor, major SO2 sources in the area, the MDNR recommended nonattainment area 

boundary (in red) and the land use and rivers surrounding the area.

Figure 14: Satellite Image Missouri’s Recommended Nonattainment Boundary Jackson 

County

Jurisdictional Boundaries 

The recommended nonattainment area includes the portion of Jackson County North of I-70/I670 and West of I-435 bounded on the West by the state line with Kansas and on the North by 

the Missouri River. The boundaries of the nonattainment area contain the violating monitor in 

the county (the Troost Monitor) and the 2nd largest source of SO2 emissions in the county –

Veolia’s Grand Avenue facility. 
The nonattainment boundaries recommended by MDNR include the following easily defined 

features – state, county or township boundaries, and large immovable features (rivers and 

highways). They are reasonable as they include the area surrounding the violating monitor, the 

source most likely contributing to the violating monitor, and are easily recognizable by the 

public.

Other Relevant Information

The existing information reviewed by EPA can be used to satisfactorily establish a 

nonattainment area boundary for the area.

Conclusion

After considering the 5 factors summarized below, EPA intends to find that it is appropriate to 

include the portions of Jackson County identified by MDNR as a nonattainment areas for the 

state of Missouri for the 2010 SO2 NAAQS. 

The air quality monitor in Jackson County, Missouri shows a violation of the 2010 SO2 NAAQS, 

based on 2009-2011 air quality data. Based on the consideration of all the relevant and available 

information, as described above, EPA believes that the boundaries described herein encompass 

the appropriate initial nonattainment area for the 2010 SO2 NAAQS.

.
Nonattainment Designations

Technical analysis for Jefferson County, Missouri

Introduction 

This technical analysis for Jefferson County, Missouri identifies the parts of the county with a 

monitor that violates the 2010 SO2 NAAQS based on 2008-2010 data, and evaluates nearby 

counties for contributions to SO2 concentrations in the area. EPA has evaluated the remainder of 

the county and nearby counties based on the weight of evidence of the factors recommended in 

the March 24, 2011, issued EPA guidance. Figure 15 depicts the nonattainment boundary and 

area (shaded in green) that EPA intends to finalize for Jefferson County, MO. The figure also 

depicts the two monitors currently recording design values exceeding the primary SO2 NAAQS, 

as well as SO2 sources emitting greater than 1000 tons of SO2 per year.

Figure 15: Jefferson County, MO Intended Nonattainment Boundary
Figure 16 below depicts the Jefferson County area and includes sources of SO2 emissions in 

Jefferson and surrounding counties, the violating monitor, as well as major highways. It is 

valuable to note that the largest single source of SO2 emissions in the area consists of Doe Run 

Lead Smelter and it is located in East-Central Jefferson County in the township of Herculaneum. 

The Doe Run Lead Smelter is also the single largest source of SO2 emissions in the state 

Missouri. 

Figure 16: Jefferson Co, Missouri Emission Sources and Monitoring Sites

In July 2011, the Missouri Department of Natural Resource (MDNR) recommended that part of 

Jefferson county be designated as nonattainment for the 2010 SO2 NAAQS based on monitored 

air quality data from 2007-2009.

Figure 17 depicts the area of nonattainment recommended by MDNR, the location of the 

significant sources in the nonattainment area, the violating monitor, and the township boundaries 

in Jefferson County included in the area of nonattainment. 
Figure 17: Missouri’s Recommended Nonattainment Boundary for Jefferson County

Based on EPA's technical analysis described below, EPA is intending to designate portion of 

Jefferson County, Missouri as nonattainment for the 2010 SO2 NAAQS based upon currently 

available information.
Detailed Assessment

Air Quality Data 

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

calculated for all air quality monitors in Jefferson Counties Missouri, and the surrounding area 

based on data for the 2008-2010 period. 

MDNR’s recommendation was based on data collected from monitor(s) located in the state

meeting the specifications of a Federal Reference Method (FRM) or Federal Equivalent Method 

(FEM) in accordance with 40 CFR Part 53 (see letter from Sara Parker Pauley Director of 

MDNR to Karl Brooks Region Administrator EPA Region 7 dated July 19, 2011) .

The 3-year design values for 2007-2009, 2008-2010, and 2009-2011 for the SO2 NAAQS for 

Jefferson County, MO are shown below in table 8.

Table 8: Air Quality Data for Nonattainment Designations in Missouri

County

State

Recommended

Nonattainment?

Monitor Name Monitor Air Quality

System ID Monitor Location

3 yr SO2 Design 

Value (ppb)

’08 thru‘10 

Jefferson, MO Yes Herculaneum 

Main Street 290990004 Jefferson Co, MO 289

Jefferson, MO Yes Herculaneum 

Mott Street* 290990027 Jefferson Co, MO NA

*Mott Street monitor was relocated from Main Street in 2011

** Data for Mott and Main Street monitor locations is incomplete in 2011. The monitor was shutdown during for an 

extended period. 

EPA was unable to establish a valid design for Jefferson County, Missouri for years 2009 to 

2011 due to incomplete monitoring data for 2011. However, the valid design value for Jefferson 

County, Missouri for the years 2008 to 2010 shows a violation of the 2010 SO2 primary 

NAAQS. In response to the incomplete data for 2011, EPA elected to use the 2008 through 2010 

data to establish a valid design value because the monitored results are representative of the 

ambient conditions that exist in the area. As a result of the violating design value for 2008 

through 2010, some area in this county must be designated nonattainment. The absence of a 

violating monitor alone is not a sufficient reason to eliminate nearby counties as candidates for 

inclusion in a nonattainment area. Each area has been evaluated based on the weight of evidence 

of the five factors and other relevant information. 

The monitor in Jefferson Co, MO recording ambient air concentrations of SO2 is showing a 

concentration substantially in excess of the 1-hr SO2 primary NAAQS. The location of the 

monitor, the surrounding terrain, and the meteorological conditions that exist during the recorded 

violations suggest that the source of the SO2 in the area is the Doe Run Lead Smelter. The 

nonattainment boundary recommended by MDNR, appropriately captures the Doe Run sources 

and properly bounds the area of nonattainment considering these factors. 

The design value establishing Jefferson County, Missouri as nonattainment for the 2010 1-hr 

primary SO2 NAAQS is based on data collected between 2008 – 2010 rather than 2009 – 2011. 
This is because the original monitor, the Herculaneum Main Street Monitor (AQS ID 

290990004) was shutdown and moved to a new location less than 1 block from the previous 

location on May 23, 2011. The monitor was restarted on June 15, 2011 in its new location on 

Mott Street (AQS ID 290990027), but the due to the period of shutdown, the data set for 2011 

was no longer complete for purposes of establishing a design value for the 2010 1-hr primary 

SO2 NAAQS. 

The monitor was relocated because the property where it was located on Main Street (previously 

owned by the City of Herculaneum) was purchased by the ownership of the Doe Run Lead 

Smelter, and MDNR no longer had access to operate the monitor by the new property owner.

EPA believes that the new monitoring location (on Mott Street) is in close enough proximity to 

the previous (main Street) location that the data for ambient concentrations of SO2 could be 

combined (and a review of the data show consistent SO2 concentration measurements before and 

after the move); however, the lack of data collection between May 23, 2011, and June 15, 2011 

caused the data to be incomplete under the provisions of 40 CFR Part 50 Appendix T, and 

therefore could not be used to establish a design value directly. Using data from both monitor 

locations and combining for the years 2009-2011, and using a conservative method of replacing 

missing data with zeros, the design value would be 164ppb, which is a violation of the 2010 SO2

primary NAAQS. In response to this situation, EPA elected to establish the design value in 

support of the nonattainment boundary designation based on 2008 – 2010 data, as that data is 

complete and continues to represent the ambient concentrations of SO2 that exist in the area at 

the present time. 

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. For this factor, 

EPA evaluated county level emissions data for SO2 and any growth in SO2 emitting activities 

since the date represented by those emissions data.

Emissions 

There are 14 sources of SO2 listed in the NEI in operation in Jefferson County. Of these sources 

only 4 have emissions of greater than 100 tons per year and 3 that emit over 100 tons of SO2 per 

year and are considered significant sources of SO2 in the Jefferson County area. All major SO2 

sources in Jefferson County are located along the Mississippi River. Overall SO2 emissions were 

down about 24% from 2007-08. This was due to a new, more accurate method of measurement at 

the Doe Run’s Herculaneum smelter which resulted in a correction of almost minus 50%, and 

reductions in electricity demand due to the recession and a mild summer. There are no significant 

sources west of Interstate 55 in the Jefferson County area.

EPA recognizes that there may be important new information on emissions levels for the period 

after 2008, and would consider more recent information if available. MDNR provided emissions 

information for large sources of SO2 in an around the three counties recommended for 

nonattainment for the years 2007 through 2009 as shown in Table 9. During our review of 
MDNR’s boundary recommendation, we relied on the 2008 National Emissions Inventory (NEI) 

as well as the emissions data supplied by the Missouri for the year 2009. The emission data for 

each county we relied on during our review is included in table 9 below. The tables shows total 

emissions of SO2 (given in tons per year) for violating and potentially contributing counties in 

and around Jefferson County, including all sources emitting greater than 100 tons per year of

SO2. 

Emissions Controls

The emissions data used by EPA in this technical analysis and provided below represent real 

emissions levels occurring at the sources and thus take into account any control strategies 

implemented on the stationary sources in Jefferson County up to and including the year 2009. 

Table 9: Large Sources of SO2 Emissions in and around Jefferson County. Missouri

SO2 emissions (tpy)

Facility 2007 2008 2009

Jefferson 

County

Ameren MO -

Rush Island 22,058 29,593 28,327

Doe Run –

Herculaneum 32,904 35,998 18,842

River Cement 

– Selma 3,018 2,758 1,069

St. Louis 

County

Ameren MO –

Meramec 22,769 20,827 16,856

Total 80,749 89,176 65,094

EPA received additional information on emissions reductions resulting from state and federally 

enforceable controls put into place up to 2010.

Also included in MDNR’s boundary recommendation technical support document is an 

assessment of the impact of federal regulations scheduled to become enforceable in the future. 

This information is not relevant to EPA’s nonattainment boundary analysis. MDNR believes 

that a significant reduction of regional emissions of SO2 will be realized as a result of these 

federal regulatory actions, and will specifically result in emission reductions at sources

impacting the areas currently not attaining the 2010 1 hr primary SO2 NAAQS. These 

regulations are not limited to, but may include: 1) the Transport Rule (aka: Cross-State Air 

Pollution Rule (CSAPR)) finalized on June 6, 2011; 2) the National Emission Standards for 

Hazardous Air Pollutants (NESHAPs) for Area Sources: Commercial Industrial and Institutional 

Boilers (finalized December 2, 2011); and, 3) the Utility MATS (finalized December 21, 2011).

Specific reductions associated with these rules are unknown as the compliance dates have not 

passed and some of these rules are subject to litigation. In addition, EPA notes that on Thursday, 

January 24, the DC Circuit Court of Appeals denied the EPA’s request for an en banc rehearing 
of its August Homer City decision vacating the Cross-State Air Pollution Rule. Currently, the 

2005 Clean Air Interstate Rule remains in effect in states. Emissions reductions from the Clean 

Air Interstates Rule will assist many areas in attaining the SO2 NAAQS. For those areas where 

more work is needed, state and local governments will develop and implement plans to reduce 

emissions from sources of significant SO2 emissions through enforceable emissions limits.

 

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 recent hourly or sub-hourly meteorological data from the metrological site(s) 

nearest to the violating monitor(s) to determine which wind vectors were associated with 1-hour 

SO2 exceedances. For the nonattainment areas recommended by MDNR, the general 

meteorological data used in MDNR’s analysis were from the years 2005 and 2007. Additionally, 

MDNR utilized highly specific meteorological data for the days and hours proceeding high 

monitored readings recorded by the violating monitors in Jefferson County (this data used for 

HYSPLIT modeling and analysis discussed more fully in a later section). The meteorological 

stations this data was collected from are operated by National Weather Service (NWS) for the 

purposes of cataloging representative weather conditions in the area. The NWS metrological 

stations used in both EPA’s and MDNR’s analysis are the stations in closest proximity to the 

violating monitor – in the case of Jefferson County analysis the nearest MWS station is located 

in St Louis, MO at the Spirit of St. Louis Airport approximately 50.0 km (32 miles) away from 

the violating monitor in Jefferson County . EPA believes that the meteorological analysis and 

data used by MDNR properly represents the meteorological conditions that impact SO2

concentrations in the area of the violating monitor. In our review of MDNR’s analysis, EPA 

used the same meteorological station as MDNR for each of the monitors, but considered 

differing years to assess the general conditions that exist in Jefferson County. In this analysis we 

confirmed MDNR’s conclusions for Jefferson County, MO: Winds in the state of Missouri 

predominantly come from the Southeast and Northwest. Winds from the Northeast are rare 

throughout the year. The greatest wind direction deviation in Jefferson County from the 

predominant wind patter in the state routinely occurs in the 2nd quarter of the year and is 

representative when the wind predominantly comes out of an area that varies equally from 

Southeast to Northwest.

MDNR supplied Wind Rose Data for Jefferson County, Missouri. Please see the docket to 

review MDNR’s wind rose analysis submitted to EPA. EPA’s qualitative assessment of the of 

the quarterly wind rose data for Jefferson county concludes that winds in the area blow 

consistently from all directions, but more consistently from headings that fall within an arc from 

the North through the West to the East. This pattern suggests that sources both North and South 

of the violating monitor may influence the concentrations detected at the monitor. However, 

because the source’s – north and south of the violating monitor - location on the Mississippi

River and the violating monitor’s location higher in elevation East of the Mississippi river, and 

the propensity of the localized topography of the river valley to disperse the emission along the 

river valley, EPA is not prepared to conclude that the sources North of the violating monitor are 
having an impact on the violating monitor. This leaves the Doe Run Lead Smelter in closest 

proximity to the violating monitor and Rush Island South of the violating as having the most 

significant impact. 

EPA performed a wind rose analysis for the years 2009 through 2011 (Figure 19) the results 

show that winds in Jefferson County predominantly blow out of the West-Southwest with the 

greatest frequency and intensity. However, winds also blow regularly out of the West-Northwest 

and South with sufficient frequency and intensity to impact the monitor on a regular basis. This 

is not inconsistent with the results of MDNR’s analysis for the year 2005. The result suggest that 

sources to the South and North-Northwest would have a greater impact on the monitor, which 

would include both the Rush Island Power Plant and the Doe Run Lead Smelter. 

Figure 19: EPA Wind Rose Analysis 2009-2011 
In addition to the meteorological wind rose analysis MDNR submitted back trajectory analysis 

derived from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. 

Back trajectory modeling assesses the path an air parcel travels during the previous 24 hours to 

arrive at particular time and location. For this modeling MDNR used meteorological data 

corresponding to the 4 highest monitored readings at each of the violating monitors in the state 

(i.e., in Jackson and Jefferson Counties, MO) The results of this analysis for can be found in the 

final recommendations submitted by MDNR to EPA in the Docket for this action.
– Jefferson County, Missouri Summary of HYSPLIT Analysis

MDNR performed 12 composite trajectory analyses on days of recorded violations, eleven of the 

trajectories come from the South moving up the Mississippi River Valley. The 12th trajectory 

comes from the West. The result of these trajectories suggest the primary source of SO2

concentrations observed at the Herculaneum Main Street monitor is from a heading slightly 

South from the direction of the Mississippi River Valley. This would strongly suggest that most 

significant source of SO2 emissions in the area of the violating monitor in Herculaneum is Doe 

Run Smelter. The nonattainment boundary recommended by MDNR properly includes the 

sources of SO2 emissions and the area where the SO2 concentration in the ambient air violates 

the NAAQS. 

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

In general, the Northern part of Missouri consists of open plains and contains few features that 

impede, restrict, or channel air speed and direction. The major geological features that can have 

small localized effects on wind direction and inversion are the Mississippi and Missouri River 

valleys. Generally, the effects of the river valleys are to channel localized air movement in a 

North-South (Mississippi) or East-West (Missouri) wind direction. The effect is not expected to 

affect the concentrations of SO2 observed at the monitoring locations (because there are no SO2

sources directly East or west of the violating monitor), but could result in limiting the sources 

that impact a particular monitor. The channeling effect of the Mississippi River valley is 

expected to be limiting the affect that both the Meramec and Rush Island power plants have on 

the violating monitor in Herculaneum township. The monitors location adjacent to the Doe Run 

Lead Smelter (the largest source of SO2 emissions in Missouri) as well as the consistently high 

concentrations recorded by the monitor on days of varying wind direction leads EPA to conclude 

that the Doe Run Smelter is the primary contributor of ambient SO2 concentrations recorded at 

the Herculaneum monitor and that one of the two power plants in closest proximity is having a 

measureable impact on the monitor. 

Figure 20 shows the Jefferson County Area including the location of the violating monitor

(purple balloon), a 12 mile radius around the violating monitor (white balloon) and major 

sources of SO2 in the area (blue balloons), as well as the MDNR recommended nonattainment 

area (outlined in red).

Figure 20: Satellite Image Missouri’s Recommended Nonattainment Boundary Jefferson 

County
Jurisdictional Boundaries 

The Jefferson County, MO Nonattainment Area includes a part of Jefferson County which 

consists of both Herculaneum and Festus townships as the Western, Northern, and Southern 

boundary of the nonattainment area, and those portions of Valmeyer and Selma townships 

directly to the East that separate Herculaneum and Festus townships from the Mississippi River 

as the Eastern boundary of the nonattainment area. This area includes the Doe Run Lead Smelter 

nearly at its center and includes the Ameren power plant (approximately 15 km) South of the 

violating monitor (Rush Island Power Plant), but does not include the Ameren plant to the North

The nonattainment boundaries recommended by MDNR include the easily defined features – the 

township boundaries, as well as a large immovable feature (the Mississippi Rivers). They are 

reasonable as they include the area surrounding the violating monitor, the source(s) most likely 

contributing to the violating monitor, and are easily recognizable by the public.

Other Relevant Information
The existing information reviewed by EPA can be used to satisfactorily establish a 

nonattainment area boundary for the area.

Conclusion

After considering the 5 factors summarized below, EPA intends to find that it is appropriate to 

include the portions of Jefferson County identified by MDNR as a nonattainment area for the 

state of Missouri for the 2010 SO2 NAAQS. 

The air quality monitor in Jefferson County shows a violation of the 2010 SO2 NAAQS, based 

on 2008-2010 air quality data. Based upon the consideration of all relevant and available 

information, as described above, EPA believes that the boundaries described herein encompass 

the appropriate initial nonattainment area for the 2010 SO2 NAAQS.