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Illinois

Area Designations For the 

2008 Lead National Ambient Air Quality Standards

EPA has revised the level of the primary (health-based) standard from 1.5 micrograms per cubic 

meter (μg/m3) to 0.15 μg/m3 measured as total suspended particles (TSP). EPA has revised the 

secondary (welfare-based) standard to be identical in all respects to the primary standard.

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. 

The table below identifies the partial county in Illinois that EPA intends to designate

“nonattainment” for the 2008 lead National Ambient Air Quality Standard (2008 lead NAAQS).

Area Illinois Recommended 

Nonattainment County

EPA’s Designated 

Nonattainment County

Chicago Cook (partial) Cook (partial)

Table 1: Illinois Nonattainment Area for the 2008 Lead NAAQS

Technical Analysis for Chicago

Introduction 

This technical analysis for Chicago identifies the partial county with a monitor that violates the 

2008 lead NAAQS, and evaluates nearby counties for contributions to lead concentrations in the 

area. EPA has evaluated these counties based on the weight of evidence of the following factors 

recommended in previously issued EPA guidance: 

Air quality in potentially included versus excluded areas;

Emissions and emissions-related data in areas potentially included versus excluded from 

the nonattainment area, including population data, growth rates and patterns and 

emissions controls;

Meteorology (weather/transport patterns);

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

Jurisdictional boundaries (e.g., counties, air districts, reservations, etc.); and,

Any other relevant information submitted to or collected by EPA.
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Figure 1: Chicago, Illinois Area and Surrounding Counties

(Office of Air Quality and Planning Standards - OAQPS)

Figure 1 is a map of the area analyzed showing the locations and design values of violating air 

quality monitors in the area, and the counties surrounding any violating air quality monitors. 

Source data is also labeled in Figure 1 with the following guidelines: if the source emitted 0.50

or more tons per year (tpy), the symbol, name of the facility, and emissions are labeled; if the 

source emitted 0.10 – 0.50 tpy, only the symbol and emissions are labeled; and if the source 

emitted less than 0.05 tpy, only the symbol is shown.1 Emissions in Chicago and the surrounding 

areas will be discussed in the section addressing emissions in Cook County. The location of the 

detailed area in relation to the remainder of the State is shown in the bottom right corner of the 

figure.

 

1 Emissions greater than 0.05 tpy round up to 0.10 tpy, and they are marked with the symbol and the emissions 

value. 
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Figure 2: Chicago, IL State Recommended Nonattainment Area Local View (OAQPS)

Figure 2 shows the location and design value of air quality monitors on a localized Chicago area 

view focusing on the area where the violating monitor is located. Again, source data is labeled 

with the following guidelines: if the source emitted 0.50 or more tpy, the symbol, name of the 

facility, and emissions are labeled; if the source emitted 0.10 – 0.50 tpy, only the symbol and 

emissions are labeled; and if the source emitted less than 0.05 tpy, only the symbol is shown. In 

this figure, the State recommended nonattainment area, which EPA is adopting, is shown by the 

blue outline. 
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Figure 3: Chicago, Illinois State Recommended Nonattainment Area (Google Earth)

Figure 3 shows the State recommended nonattainment area boundary for the Chicago area. The 

boundary is shown the red outline, and is encompassed by the following roads or thoroughfares: 

Roosevelt Rd. to the north, the Dan Ryan Expressway to the east, the Stevenson Expressway to 

the south, and Damen Ave. to the west. In this map, the distance between Roosevelt Rd. (at the 

north) and the Stevenson Expressway by way of Western Ave. (at the western edge of the map) 

is 2.15 miles. The distance between Western Ave. and Halsted St. is 2.0 miles. 

In June 2011, Illinois recommended that portions of Cook County be designated as 

nonattainment for the 2008 lead NAAQS based on monitored air quality data collected between 

2008 and 2010. The State’s recommendation was based on data from Federal Reference Method 

(FRM) or Federal Equivalent Method (FEM) monitors located in Illinois. Laurel L. Kroack, 

Director of the Bureau of Air at the Illinois Environmental Protection Agency (IEPA), submitted 

the State’s recommendation to EPA in a letter dated June 10, 2011. 

On June 15, 2011, EPA notified the State of Illinois of our proposed decision to accept the 

State’s recommended nonattainment designation and associated boundaries. EPA also asked that 

if the State had additional information that it wanted EPA to consider with respect to the 

proposed nonattainment area and associated boundaries, the State submit this information by 

August 15, 2011. EPA received no additional information from the State of Illinois.
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On June 21, 2011, EPA published a Federal Register notice notifying the public that we had 

posted our responses to States’ recommendations for the 2008 lead NAAQS (76 FR 36042). 

This same notice simultaneously opened a comment period inviting the public to comment on 

our responses to States’ recommendations. During the public comment period, which ended on 

July 21, 2011, we received six sets of comment pertaining to our proposed acceptance of Illinois’ 

nonattainment designation for the 2008 lead NAAQS and associated boundaries for the Chicago 

area. Summaries of these comments and our responses to them can be found in the Response to 

Comments document in the docket for this action.

Based on EPA’s technical analysis described below, EPA is designating portions of Cook 

County in Illinois as nonattainment for the 2008 lead NAAQS as part of the Chicago 

nonattainment area based upon currently available information. This county is listed above in 

Table 1.

Detailed Assessment

Air Quality Data 

This factor considers the lead design values (in μg/m3) for air quality monitors in Cook County 

in Chicago and the surrounding area based on data for the 2008 – 2010 period. A monitor’s 

design value indicates whether that monitor attains a specified air quality standard. The 2008 

lead NAAQS are met at a monitoring site when the identified design value is valid and less than 

or equal to 0.15 μg/m3. A design value is only valid if minimum data completeness criteria are 

met. A lead design value that meets the NAAQS is generally considered valid if it encompasses 

36 consecutive valid 3-month site means (specifically for a 3-year calendar period and the 2 

previous months). For this purpose, a 3-month site mean is valid if valid data were obtained for 

at least 75 percent of the scheduled monitoring days in the 3-month period. A lead design value 

that does not meet the NAAQS is considered valid if at least one 3-month mean that meets the 

same 75 percent requirement is above the NAAQS. That is, a site does not have to monitor for 3 

full calendar years in order to have a valid violating design value; a site could monitor just 3 

months and still produce a valid (violating) design value.

The 2008 lead NAAQS design values for Cook County in Chicago and the surrounding area are 

shown in Table 2 below, and a monitor in Cook County violates the 2008 lead NAAQS. 

Therefore, some area in this county and possibly additional areas in surrounding counties must 

be designated nonattainment. It should be noted there are multiple monitors in Cook County, but 

the remainder of the monitors in Cook County have recorded air quality data showing that the 

2008 lead NAAQS has not been violated. IEPA has recommended only the area surrounding the 

violating monitor as nonattainment for the 2008 lead NAAQS. This particular monitor, located 

at 1241 W. 19th St. (AQS ID 17310110), is in very close proximity to H. Kramer & Company 

(Kramer). The primary products manufactured at this facility are brass and copper ingots. The 

location of this monitor will be discussed in the section addressing emissions for Cook County. 

However, the absence of a violating monitor alone is not a sufficient reason to eliminate nearby 

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

of evidence of these factors and other relevant information. 
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County State

Recommended

Nonattainment?

Monitor Name Monitor Air 

Quality

System ID

Monitor Location Lead Design 

Value,

2008-2010

(μg/m3)

Cook, 

Illinois

Yes Perez 

Elementary

17310110 1241 W. 19th St.

(41.85577, 

-87.65793)

0.24

Cook, 

Illinois

No Alsip 170310001 4500 W. 123rd St. 

(41.67099, 

-87.73246)

0.02

Cook, 

Illinois

No 114th St. 170310022 3535 E. 114th St. 

(41.68717,

-87.53932)

0.05

Cook, 

Illinois

No Harrison 170310026 735 W. Harrison St. 

(41.87372, 

-87.64533)

0.05

Cook, 

Illinois

No Wilson 170310052 4850 Wilson Ave. 

(41.96548, 

-87.74993)

0.02

Cook, 

Illinois

No Schiller Park 170313103 4743 Manheim Rd. 

(41.96519, 

-87.87626)

0.01

Cook, 

Illinois

No Summit 170313301 Intersection of 60th 

St. and 74th Ave. 

(41.78277, 

-87.80538)

0.03

Cook, 

Illinois

No Northbrook 170314201 750 Dundee Rd. 

(41.14000, 

-87.79923)

0.01

Cook, 

Illinois

No Maywood 170316003 1500 Maybrook Dr. 

(41.87220, 

-87.82616)

0.04

The monitor in bold has the highest 2008 - 2010 design value in the respective county.

Table 2: Chicago, Illinois and Surrounding Area Air Quality Data

Emissions and Emissions-Related Data

Evidence of lead emissions sources in the vicinity of a violating monitor are an important factor 

for determining whether a nearby area is contributing to a monitored violation. For this factor, 

EPA evaluated county level emission data for lead and any growth in lead emitting activities

since the date represented by those emissions data.

Emissions

Emissions data for industrial sources were derived from the 2008 National Emissions Inventory, 

version 1.5 (NEI08V1.5), which was the most current version of the national inventory available 

in 2011 when these data were compiled for the designations process.2 See 

 

2 There are approximately 20,000 airport facilities in the U.S. at which leaded aviation gasoline is consumed; this 

fuel is used almost exclusively in piston-engine aircraft. Emissions data from the 2008 National Emissions 
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http://www.epa.gov/ttn/chief/net/2008nei_v1/lead_facility_v1_5_final.xls. EPA recognizes that

for certain counties, we have no information on any emissions increases or decreases that may 

have occurred since 2008. For example, certain large sources of emissions in or near this area 

may have installed emission controls or otherwise significantly reduced emissions since 2008. 

Some States provided updated information on emissions and emission controls in their comments 

to EPA. Illinois did not provide emissions data for Cook County in its June 2011 submittal.

Table 3 shows total emissions of lead for violating and potentially contributing counties in and 

around the Chicago area. Specifically, sources in Cook County that emit 0.1 tpy or greater of 

lead (or sources that EPA anticipates as contributing at least 0.1 tpy) according to the NEI08V1.5

and NEI08V1 have been identified in Table 3. 

County

Facility in State 

Recommended 

Nonattainment 

Area? Facility Name

NEI08V1.5

(tpy) Address City

Cook County, 

Illinois No Signode Corp. 0.6 7701 W. 71st St. Bridgeview

Cook County, 

Illinois No

Mittal Steel USA -

Riverdale Inc. 0.4 13500 S. Perry Ave. Riverdale

Cook County, 

Illinois No

Saint-Gobain 

Containers Inc. 0.3

13850 Cottage Grove 

Ave. Dolton

Cook County, 

Illinois No Sipi Metals Corp. 0.3 1720 N. Elston Ave. Chicago

Cook County, 

Illinois No Hoist Lift Truck 0.2 6499 W. 65th St. Chicago

Cook County, 

Illinois No Horsehead Corp. 0.2 2701 E. 114th St. Chicago

Cook County, 

Illinois No C.E. Niehoff & Co. 0.2 2021 Lee St. Evanston

Cook County, 

Illinois Yes H. Kramer & Co. 0.1 1339 W. 21st St. Chicago

Cook County, 

Illinois No

Corn Products 

International Inc. 0.1 6400 S. Archer Ave.

Bedford 

Park

Cook County, 

Illinois No

Plastics Color Corp.

of Illinois 0.1 14201 Paxton Ave.

Calumet 

City

Cook County, 

Illinois No

Crawford Electric 

Generating Station 0.1 3501 S. Pulaski Ave. Chicago

Cook County, 

Illinois Yes

Fisk Electric 

Generating Station 0.1 1111 W. Cermak Rd. Chicago

Cook County, 

Illinois No

Chicago Extruded 

Metals Co. 0.1 1601 S. 54th Ave. Chicago

Cook County Total 

Lead Emissions* 4.3

Table 3: Cook County Lead Emissions for Stationary Sources

*Total emissions for Cook County included emissions from airport facilities using leaded aviation fuel. 

The total emissions also include emissions from sources that emit less than 0.1 tpy.

 

Inventory version 1 (NEI08V1) is the most accurate depiction for the airport facilities in the United States, and 

NEI08V1 data was used in evaluating emissions from these facilities in Cook County. 
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The monitor located at 1241 W. 19th St. was deployed in January 2010 as part of Illinois’ 

expanded ambient monitoring network for lead,3and as discussed previously is in very close 

proximity to Kramer. As reflected in Table 3, there are two facilities in the State recommended 

nonattainment area that emit at, or above, 0.1 tpy of lead. Kramer is one of these facilities, as is 

the Fisk Electric Generating Station. Analysis performed by IEPA indicates that the Kramer 

facility is primarily responsible for the elevated levels of lead in the State recommended 

nonattainment area. This analysis will be discussed in the section addressing other relevant 

information. 

Figure 4 below shows the location of Kramer (red star) and the monitor associated with this 

facility (yellow pin). The distance between the center of the facility and the monitor is 

approximately 964’, or 0.18 miles. Additional discussion about the characteristics of this area 

follows below.

Figure 4: Perez Elementary School Monitor Location (Google Earth)

Population Data, Growth Rates, and Patterns 

Table 4 shows the 2008 population for each county in the area being evaluated, as well as the 

population density (people/square mile) for each county in that area. These data help assess the 

 

3 Counties in Illinois with lead monitors deployed prior to January 2010 include: Macoupin, Madison, Peoria, St. 

Clair, and elsewhere in Cook. In addition to the monitor located at 1241 W. 19th St., monitors were also deployed in 

January 2010 in the following locales in Illinois: Rockford, Decatur, Bartonville, Mapleton, and Sterling.
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extent to which the concentration of human activities in the area and concentration of populationoriented commercial development may indicate emissions-based activity contributing to elevated 

ambient lead levels. This may include ambient lead contributions from activities that would 

disturb lead that has been deposited on the ground or on other surfaces. Re-entrainment of 

historically deposited lead typically is not reflected in the emissions inventory.

County State 

Recommended 

Nonattainment?

2008 

Population

2008

Population 

Density 

(pop/sq mi)

Population 

Change 

2000-2008

Population % 

Change 

2000-2008

Cook, Illinois No (partial) 5,294,664 5,535 -82,428 -2

Table 4: Population Data for Cook County, Illinois

(U.S. Census Bureau estimates for 2008 and estimation of the area of U.S. Counties)

http://www.census.gov/popest/datasets.html

Specific to the immediate area surrounding the Kramer facility are the following traits: a 

population density of greater than 7,500 persons per square mile (the 2000 Census reports that 

the area actually has a population density of approximately 15,000 persons per square mile); a 

significant representation of children under 18 years of age; a significant representation of those 

that do not speak English well; a significant representation of those that have less than a 12th

grade education; and, a significant representation of families that live at or below the poverty 

level. 

Emissions Controls

Under this factor, the existing level of control of emission sources is taken into consideration. 

The emissions data used by EPA in this technical analysis and provided in Table 2 represent 

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

Chicago before 2008. As part of its June 2011 submittal, Illinois EPA did not include additional 

information on controls put into place since 2008 at the Kramer facility.

Meteorology (weather/transport patterns)

For this factor, EPA considered 32 years of data from National Weather Service instruments and 

other meteorological monitoring sites in the area. Historical wind direction frequencies are 

included in Figure 5 and Table 6. These data may provide evidence of the potential for lead 

emissions sources located upwind of a violating monitor to contribute to ambient lead levels at 

the violation location. 
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Figure 5: Historical Wind Direction Frequencies for Cook County, Illinois

Figure 5 is a 3-dimensional bar chart that shows the wind frequencies in 8 directions for the 4 

seasons. These data are taken from 1960-1992 Solar and Meteorological Surface Observation 

Network information issued jointly by the U.S. Department of Commerce: National Climatic 

Data Center and the U.S. Department of Energy: National Renewable Energy Laboratory. The 

chart frequencies reflect the directions from which the winds come. 

Cook County

Wind Frequencies

Frequency as a %

Seasonal Wind 

Directions

8.20 WINWINDFNNE

5.40 WINWINDFENE

5.30 WINWINDFESE

7.40 WINWINDFSSE

20.40 WINWINDFSSW

17.90 WINWINDFWSW

23.40 WINWINDFWNW

12.00 WINWINDFNNW

17.30 SPRWINDFNNE

11.40 SPRWINDFENE

9.90 SPRWINDFESE

9.10 SPRWINDFSSE

17.90 SPRWINDFSSW

12.50 SPRWINDFWSW

14.10 SPRWINDFWNW
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7.90 SPRWINDFNNW

15.50 SUMWINDFNNE

8.70 SUMWINDFENE

7.70 SUMWINDFESE

9.30 SUMWINDFSSE

24.10 SUMWINDFSSW

15.90 SUMWINDFWSW

12.70 SUMWINDFWNW

6.00 SUMWINDFNNW

10.20 AUTWINDFNNE

5.60 AUTWINDFENE

5.90 AUTWINDFESE

11.10 AUTWINDFSSE

25.70 AUTWINDFSSW

15.00 AUTWINDFWSW

16.80 AUTWINDFWNW

9.80 AUTWINDFNNW

Table 5: Historical Wind Frequency Data as Percents for Cook County, Illinois

As shown in Figure 5 and Table 5, winds blowing from a variation of the southwest are prevalent 

in all seasons; therefore, special care must be made when determining the nonattainment 

boundary to the east and northeast of the violating monitor. 

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

The geography/topography analysis evaluates the physical features of the land that might have an 

effect on the air shed and, therefore, on the distribution of lead over Chicago and the surrounding 

area. 

The Chicago area does not have any geographical or topographical barriers significantly limiting 

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

determining the nonattainment boundary.

Jurisdictional boundaries 

Existing jurisdictional boundaries may be helpful in articulating a boundary for purposes of 

nonattainment designations, and for purposes of carrying out the governmental responsibilities of 

planning for attainment of the lead NAAQS and implementing control measures. 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.

In EPA’s August 21, 2009 guidance memorandum, “Area Designations for the 2008 revised 

Lead National Ambient Air Quality Standard,” EPA reiterated that the presumptive boundary for 

each nonattainment area should be the county containing the violating monitor. This concept 

was first introduced in the guidance for the 1978 lead NAAQS designations, and is described in 

the 1992 General Preamble (57 FR 13549). This same presumptive boundary guidance was 
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addressed most recently in the final rulemaking for the 2008 lead NAAQS (73 FR 66964). EPA 

observed, however, that States have the flexibility in their recommendations to deviate from the 

presumptive county boundary to portions of the county containing the violating monitor, stating 

that any “nonattainment area boundaries that deviate from presumptive county boundaries should 

be supported by an assessment of several factors...,” all of which have been discussed already in 

this document, except for jurisdictional boundaries.

The State recommended nonattainment area is completely enclosed by the city of Chicago and 

Cook County. The Chicago Metropolitan Agency for Planning is responsible for transportation 

infrastructure, land use, and long term economical development for Cook County, and IEPA is 

responsible for all air quality regulatory programs in every county in the State.. As a result, air 

quality planning efforts to address the impending lead nonattainment area in Chicago should not 

be problematic. It should be noted that the final rulemaking for the 2008 lead NAAQS (73 FR 

66964) specifically addressed transportation conformity by stating, “In light of the elimination of 

lead additives from gasoline, transportation conformity does not apply to the Lead NAAQS.” 

The State recommended boundaries for the Chicago nonattainment area are comprised of wellknown streets and thoroughfares. 

Other Relevant Information

EPA received additional relevant information from Illinois for establishing the nonattainment 

area boundary for Chicago. This information will be discussed below.

As reflected in Table 3, there are two sources in the State recommended nonattainment area that 

have reported emissions of approximately 0.1 tpy. Previous discussion of meteorological data 

indicates that there is a very strong representation of winds that blow from the southwesterly 

direction. Through its own analysis, IEPA has determined that the highest concentrations of lead 

have been recorded at the Perez Elementary School monitor when the wind has come from the 

southwest. IEPA provided the following information to EPA February 22, 2011:

Date

Monitored Value

(μg/m3) Wind Direction

12/10/2010 1.53 SW

4/2/2010 1.40 SW

8/30/2010 0.90 S

12/28/2010 0.77 SW

9/23/2010 0.62 SW

5/2/2010 0.26 SW

11/22/2010 0.23 SW

7/19/2010 0.21 SW

10/29/2010 0.21 SW

6/25/2010 0.17 S

6/1/2010 0.16 SE

Table 6: Wind Direction on Dates with Highest Monitored Values

Table 6 displays data that is sorted by the highest monitored values recorded at the Perez 

Elementary School monitor. As reflected in the table, the highest values monitored values 
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generally occurred on days when the wind was blowing from the southwest. This trend is 

consistent with the relationship between the location of the monitor and the Kramer facility. 

Based on the location of Kramer in relationship to the monitor, IEPA preliminarily determined 

that Kramer is responsible for the elevated lead levels in the State recommended nonattainment 

area.

In order to confirm this finding, IEPA installed a temporary second monitor located at Benito 

Juarez High School on March 11, 2011. The locations of the temporary monitor, the Perez 

Elementary School monitor, as well as the Kramer facility are contained in Figure 6 below. 

Figure 6: Location of Monitors in Relation to H. Kramer & Company

Based on the data collected at the temporary monitor in conjunction with their initial analysis of 

wind direction and monitored values at the Perez Elementary School monitor, IEPA has 

concluded the Kramer facility is the source responsible for the elevated lead levels in the State 

recommended nonattainment area.

EPA observes that the State and/or EPA may conduct additional area-specific analyses that could 

lead to a departure from the presumptive boundary of the entire county. Specifically, boundaries 

may be recommended based on the preceding factors analysis and one or more of the following 
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techniques: qualitative analysis, spatial interpolation of air quality monitoring data, and air 

quality dispersion modeling. 

EPA’s own additional analysis includes a conservative approach to interpolating the dispersion 

of lead emissions from the Kramer facility in a linear fashion. Due to the physical properties of 

lead, the greatest impact of lead emissions is generally closest to the source, but EPA is assuming 

through a linear interpolation that if the monitored value at Perez Elementary School is 0.24 

μg/m3at a distance of approximately 0.20 miles away from the facility in the downwind 

direction, a distance of 0.40 miles from the facility should capture likely impacts of 

approximately 0.12 μg/m3. The distance from the Kramer facility to the northeast edge of the 

State recommended nonattainment area is approximate 1.2 miles. Based on the information

provided by IEPA, EPA’s spatial interpolation and historical experience with other lead 

designations, and further taking into consideration the emissions from Fisk Generating Station 

and its location relative to the monitor and the boundaries, EPA believes that the State 

recommended nonattainment area is a sufficient and conservative approach to capture all areas 

with ambient concentrations of lead equal to, or greater than, the 2008 lead NAAQS. 

Conclusion

After considering the factors described above, EPA has determined that it is appropriate to 

designate portions of Cook County as nonattainment for the 2008 lead NAAQS.

The air quality monitor in Cook County shows a violation of the 2008 lead NAAQS, based on 

2008-2010 air quality data. The cumulative process of the multi-factor analysis in conjunction 

with the additional information provided by the State and a conservative approach to spatial 

interpolation of lead concentrations supports the final nonattainment area. EPA finds it 

appropriate to designate the portions of Cook County that are encompassed by Damen Ave. on 

the west, Roosevelt Rd. on the north, the Dan Ryan Expressway on the east, and the Stevenson

Expressway on the south, as nonattainment for the 2008 lead NAAQS. This area is depicted 

below in Figure 7. 

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

EPA believes that the boundaries described herein encompass the entire area that does not meet 

(or that contributes to ambient air quality in a nearby area that does not meet) the 2008 lead 

NAAQS. 
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Figure 7: Chicago, Illinois Nonattainment Area Boundaries
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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 

2008 lead NAAQS, based on the most recent 3 years of quality assured air quality monitoring 

data from 2008-2010 including at least a singular valid 3-month site mean above the level of the 

2008 lead NAAQS, or that contributes to a violation in a nearby area. 

2) Designated “unclassifiable/attainment” area – an area which EPA has determined does not 

contribute to a violation of the 2008 lead NAAQS in a nearby area and either: (1) meets the 2008 

lead NAAQS, based on the most recent 3 years of quality assured air quality monitoring data 

from 2008-2010 including 36 consecutive valid 3-month site means (including the last 2 months 

of 2007), or (2) has no monitors or has incomplete air quality monitoring data for 2008-2010 but

has no violations of the 2008 lead NAAQS.

3) Designated “unclassifiable” area – an area which EPA has determined cannot be classified 

on the basis of available information as meeting or violating the 2008 lead NAAQS, based on the 

most recent 3 years of quality assured air quality monitoring data from 2008-2010, but for which 

available monitoring data from the same or a recent period indicate a significant likelihood that 

the area may be violating the 2008 lead NAAQS.

4) Recommended nonattainment area – an area a State or Tribe has recommended to EPA be 

designated as nonattainment.

5) Violating monitor – an ambient air monitor whose valid design value exceeds 0.15 

micrograms per cubic meter (ug/m3). As described in Appendix R of 40 CFR part 50, a violation 

can be based on either Pb-TSP or Pb-PM10 data and only three months of data are necessary to

produce a valid violating design value. 

6) 1978 lead NAAQS – 1.5 μg/m3, National Ambient Air Quality Standard for lead promulgated 

in 1978. Based on Pb-TSP indicator and averaged over a calendar quarter.

7) 2008 lead NAAQS – 0.15 μg/m3, National Ambient Air Quality Standard for lead 

promulgated in 2008. Based on Pb-TSP indicator and a three-month rolling average. Pb-PM10 

data may be used in limited instances, including to show nonattainment.