1 MISSOURI EPA’s Area Designations f or the 2008 Lead National Ambient Air Quality Standard s

Introduction 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 counties or portions of counties in Missouri that EPA intends to designate “nonattainment” for the 2008 lead national ambient air qualit y standard (2008 Lead NAAQS). Table 1. Missouri Lead NAAQS Nonattainment Areas Area Missouri Recommended Nonattainment Counties EPA’s Designated Nonattainment Counties Nonattainment area for 1978 Lead NAAQS Jefferson County Jefferson County (partial) Jefferson County (partial) City L imits of Herculaneum Iron County Iron, Dent, and Rey nolds (partial) Iron, Dent, and

Rey nolds (partial) None* * Portions of western Iron County identified as Maintenance Area s Within one y ear of a new NAAQS rulemaking, Section 107(d)(1) of the Clean Air Act requires the Governor of each state to submit to the EPA a list of all areas (or portions thereof) designating those areas as nonattainment, attainment or unclassifiab le. Further, EPA is required to designate all areas (or portions thereof) no later than two y ears following the new NAAQS rulemaking. However, the period of time EPA has to promulgate the designations may be extended by

one ye ar if insufficient informati on exists to make the designations. In the Federal Register n otice for the f

inal l ead NAAQS r

ule, EPA recognized that the existing lead monitoring network is insufficient to evaluate attainment for the new NAAQS at locations consistent with EPA’s proposed new monitoring network siting criteria and data collection requirements. Man y new ambient lead monitors only began operation in January 2010. Therefore, EPA intends to designate nonattainment areas, those with existing violating monitors, in October 201 0. In the designations due in October 2011, EPA will promulgate designations for areas not designated b y this action.2 Technical Analysis Th e following technical anal ys is includes the Missouri counties of Jefferson , Iron, Dent and Rey nolds. The Doe Run Company ’s (Doe Run’s) Herculaneum primary lead smelter facilit y is the source in the Jefferson County nonattainment area, and its Buick secondary smelter and Buick mining and milling facilities are the sources in the Iron County nonattainment area which extends to portions of Dent County to the west and Rey

nolds County

to the south. Jefferson and Iron Counties in the state of Missouri both contain monitors that violate the 2008 L ead NAAQS. N earb y counties or other potential sources for contributions to lead concentrations in the nonattainment area were also considered . EPA has evaluated these counties based on the weight of evidence of the following factors recommended in previous EPA guidance :

 Air quality

in potentiall y included versus excluded areas ;
 Emissions and emissions
- related data in areas potentially included versus excluded from the nonattainment area , including population data, growth patterns, and emissions controls;
 Meteorology

(weather/transport p atter n s) ;
 Geograph y/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. Jefferson County, Missouri Nonattainment Area The Doe Run Herculaneum facility is currentl y the only operating primary lead smelter in the U.S. The facilit y has been in operation since 1892. The city of Herculaneum is currently designated nonattainment for the 1978 NAAQS. Figur e 1 is a map of the area anal yz ed depicting the location and design value of air quality monitors
. For each revision to a NAAQS EPA is required to conduct a separate designation action, which may result in the same or a different nonattainment boundary
. On December 28, 2009 , the State of Missouri recommended that a portion of Jefferson County , Missouri, identified in Figure 1 , be designated as “nonattainment” and that two other portions be designated “un classifiable” for the 2008 Lead NAAQS based on air quality data from 2007 through 2009 . The state’s recommendation 1 was based on data from Federal Reference Method (FRM) or Federal Equivalent Method (FEM) monitors located in Jefferson County and its evaluation of boundary

considerations (e.g., modeling, historic data, interpolation, etc.)
.

1 Letter from Mark Templeton, Direc tor, Missouri Department of Natural Resources, to William Rice, Acting Regional Administrator, U. S. Environmental Protection Agency, Region VII, dated December 28, 2009.3



## Figure 1. Herculaneum (Je fferso n Coun ty , MO)

Recommended boundary is the area within the Herculaneum city limits (as the city limits are defined when this document is adopted on December 3, 2009) * Sources that are not labeled emitted less than 0.05 tp y .4

Based on currently

available information and EPA's technical analy sis described below, EPA is designat ing a portion of Jefferson County as nonattainment for the 2008 Lead NAAQS. The EPA designated nonattainment area for the 2008 NAAQS depicted in Figure 1 is the same area as previousl y designated for the 1978 Lead NAAQS
. Due to uncertainties in the currentl y available information discussed in the technical anal ys is below, EPA believes there is insufficient information on which to base a designation for the remainder of the count y and intends to allow additional time to collect and evaluate data to demonstrat e that violations are not occurring in these excluded portions of Jefferson County
. Depending on the outcome of the additional data collection, EPA may in October 2011 extend the nonattainment boundary as appropriate. 1. Air Quality Data This factor considers the l ead design values (in μg/m 3 ) for air quality monitors in Jefferson County at the Herculaneum primary smelter and in the surrounding area based on data for the 2007 to 2009 period. A monitor’s design value is the highest three
- mo nth average over a three ye ar period; in this case, 2007 through 2009. The design value determines whether that monitor attains a specified air quality standard. The 2008 Lead NAAQS is met at a monitoring site when the identified design value is valid an d less than or equal to 0.15 μg/m 3 . A lead design value that meets the NAAQS is generall y considered valid if it encompasses 36 consecutive valid three
month site means (specifically , for a three
- ye ar calendar period and the two previous months). A desig n value is only

valid if data collection, quality assurance/quality

control (QA/QC), monitor siting, and minimum data completeness criteria specified in 40 CFR Part 58 are met. The 2009 Lead NAAQS design values for the Jefferson County nonattainment area are shown in Table 2
. Table 2. Air Quality Data County State

Recommended Nonattainment? Monitor Name 1 Monitor Air Quality Sy stem ID Monitor Location Lead Design Value, 2007
- 2009 (μg/m 3 ) 2 Jefferson County (Herculaneum) Yes (partial) Bluff 29
- 099
- 0011 38.26744,
- 90.37403 0.85 Broad St 29
- 099
- 0015 38.26182,
- 90.37867 2.89 Circle St 29
- 099
- 0021 38.26516,
- 90.37733 1.32 Dunklin HS 29
- 099
- 0005 38.26728,
- 90.37912 0.73 Main St 2 29
- 099
- 0004 38.26332,
- 90.37822 2.01 1 Monitors owned and operated by MDNR 2 High values in 2007 and 2008 established the design values for the MDNR monitors

2 It should be noted that the Main Street monitor records the highest concentration s for the ambient monitoring locations as the Broad Street monitor is no longer an ambient monitor for purposes of determining compliance with the 2008 Lead NAAQS since it is currently within Doe Run’s fenceline.5 Figure 2. Herculaneum Ambient Air Monitor Locations6

Monitoring data from the five monitors operated by MDNR in the vicinit y of the H erculaneum primary smelter show a violation of the 2008 Lead NAAQS as shown in Table 2 above
. There are five additional air monitors operated b y Doe Run that also show violations; the Doe Run monitoring results are comparable with the MDNR sites
. Because Jefferson County contains at least one ambient monitor that has a Lead Design Value that is above 0.15 μg/m 3 , the boundary of the nonattainment area is presumed to be the county
. Figure 2 de picts all air monitoring locations from 1995 to the present in the vicinity of the Herculaneum primary

smelter. Historic air monitoring results from 1995 to the present indicate that State Implementation Plan (SI P) control strategies at the Herculaneum fa cility implemented in both 2001 and 2007 resulted in significant reducti ons in the ambient lead concentrations at these monitoring locations. The 2001 SI P plan included requirements to enclose process buildings, install ventilation sy stems that filtered g ases through high
- efficiency baghouse sy stems, work practice standards, process throughput restrictions and hours of operation limitations. The 2007 SIP 3 required extensive controls on material handling and delivery sy stems, additional process controls an d ventilation, and provides for the enforcement of the controls in the Work Practices Manual revision. Despite the controls implemented as a part of past SI P revisions, all of the existing monitors (pre
- 2010) owned and operated by MDNR within the Herculan eum cit y limits have recorded measurements exceeding the 2008 NAAQS. In accordance with the Lead NAAQS Final Rule, the presumptive boundary is the entire count y with a violating monitor. The State and/or EPA may conduct additional area
- specific anal ys es that could lead to a departure from the presumptive boundary
. Bound aries may

be recommended on the basis of one or an y combination of the following techniques in addition to the eight
- factor anal ys is :

 Qualitative anal ys is;  Spatial interpolation of air quality monitoring data; or  Air quality

simulation by dispersion modeling. MDNR elected to use spatial interpolation of adjusted ambient air quality data and dispersion modeling for making its boundary recommendation to EPA. EPA evaluated MDNR’s anal ys is and conducted independent verification and anal ys is as discussed below. In addition to the five MDNR air monitors located near the Herculaneum smelter facility , there were two ambient air monitors for lead located outside the Herculaneum city limits : Ursuline to the south; and Dow Pevely to the north
. The Thurwell monitor was previously located to the northwest and the Golf Course monitor was located to the west of the Herculaneum facil ity , but within the city

limits
. These four monitors were discontinued in late 2005 because the results met the 1978 NAAQS which is 1.5 ug/m 3 . There are no monitoring data for areas outside the existing or state
- recommended nonattainment boundary from late 2005 through the end of 2009 ; however, in January

2010, two monitors were established to replace the Dow
- Pevel y monitoring
3 “ 2007 Revision of the SIP for the Hercu laneum Lead Nonattainment Area,” adopted by the Missouri Air Conservation Commission on April 26, 2007 . EPA has proposed to approve the 2007 SIP for Herculaneum, but has not yet taken final action (FR52701)
.7

site to the north and one monitor was established to the south to replace the Ursuline monitor. Figure 3 depicts the locations of the Dow Pevel y, Ursuline, Golf Course, Thurwell and Dunklin air monitors surrounding the Herculan eum facility
. In its TSD, 4 MDNR us ed a ratio
- based method to estimate the concentrations of lead at the locations of the four monitors discontinued in 2005, two of which are located outside the existing nonattainment boundary , as a part of its technical anal ys is in support of the boundary recommendation. The MDNR calculated the ratio of every three
- month rolling average from 2000 to 2005 for each discontinued monitor to those same averages at the D unkli n High School monitor . After examining the highest, lowest and average ratios for each discontinued monitor, MDNR chose to use the average plus one standard deviation as the factor to adjust the maximum three
- month rolling average concentration from the Dunklin High School monitor after 2007 to approximate concentrations at the discontinued monitors for the same time period. More specificall y, MDNR multiplied the average ratio plus one standard deviation for each of the four discontinued monitors by the highest post
- 2007 three
- month rolling average concentration from th e Dunklin High School monitor (i.e., 0.386 ug/m 3 ) to provide approximations of the highest post
- 2007 concentrations for all four discontinued monitors. The estimation method used data from the Dunklin High School monitor to estimate post
- 2005 monitoring results for the discontinued monitors because it is the most distant monitori ng location from the source with continuous data. The results of this anal ys is are provided in Table 3 below. Table 3. Ratio - Adjusted Historic Monitoring Data for Interpolation Dow
- Pevely Golf Course Ursuline Thurwell Max conc (2001) 0.560 0.506 0.251 0.306 1 Max Ratio 0.7342 1.1078 0.4503 1.4629 Min Ratio 0.0524 0.0201 0.0185 0.2871 Avg Ratio 0.2268 0.2592 0.1290 0.8928 Std Dev 0.1319 0.2101 0.0793 0.4370 Avg + 1 Std Dev 0.3587 0.4693 0.2083 1.3298 Post
- 2007 H. S. Max 0.386 0.386 0.386 0.386 Ratio Adj 2007 Conc 0.139 0.181 0.081 0.514 Max 3
- month Rolling (post
- 2001) 0.192 (Feb

– Apr 03) 0.232

(Dec 04

– Feb 05) 0.084

(Aug
- Oct 02) 0.330

(Nov 04
- Jan 05) 1 The Thurwell monitor was only operated in 2004 and 2005; the maximum concentration was detected in 2005. The ratio
- based approximations of post
- 2007 ambient lead concentrations highlighted in bold above, subject to the uncerta inties discussed below, suggest compliance with the 2008 l ead NAAQS for the two discontinued monitors outside the existing nonattainment boundary for Herculaneum. The ratio
- based approximations of the Golf Course and Thurwell monitors

4 “T echnical Support Document for Recommenda tion of Nonattainment Boundaries in Missouri for the 2008 Lead National Ambient Air Quality Standard,” Missouri Department of Natural Resources, Division of Environmental Quality, Air Pollution Control Program, December 3, 2009.8

Figure 3. Location of Herculaneum Air Monitors used for Ratio - Based Estimation 5

5 The data depicted in Figure 3 represent historic (pre
- 2005) monitoring results.9

located within the EPA designated nonattainment boundary suggest possible violations of the 2008 lead NAAQS. MDNR considers its ratio
- based anal ys is to be conservative because the average plus one standard deviation and the highest recorded concentration from the Dunklin High School monitor after the 2007 state mandated controls were implement ed; this value was recorded in February

through April 2009. The EPA conducted an independent anal y sis of the correlation of the monitoring data from the Dow
- Pevel y and Urs u line sites with the data collected from the Dunklin High School monitor util izing daily

values from 2000
- 2005. The Pevely monitor was the focus of the anal ys is because it is the o nl y monitor outside the proposed nonattainment boundary reporting a violation of the 2008 NAAQS after 2001. The correlation coefficient (R) and the coefficient of determination (R2 ) were calculated to determine both how well the data correlate and how wel l the regression best fits the data. Data that correlate well will have an R value closer to 1.0, indicating unit y or perfect correlation. For the coefficient of variation, the higher the R 2 values the greater the number of data points that are close to the best fit line, e.g., 1.0 indicates 100% of the data fit the regression. It should also be noted that the data set was evaluated to eliminate void, missing and

/or extra data to ensure a valid comparison for specific dates at each s ite
. Table 4. Anal ysis of Correlation (R) and Coefficient of Determination ( R2 ) for Pevely and

Dunklin High School Lead Monitoring Results from 2000 - 2005 Year Correlation (R) Coefficient of Determination ( R2 ) 2000 0.72 0.52 2001 0.57 0.32 2002 0.35 0.12 2003 0.05 0.003 2004 0.35 0.12 2005 0.26 0.07 As the data in Table 4 above indicate, the correlation of the data from the Dow Pevely and Dunklin High School monitoring sites is not very strong . The correlation between the two data sets is most likely

affected by meteorological conditions, particularly wind speed and direction, and emissions activity
. MDNR provided further anal ys is using spatial interpolation of the ratio
- based estimation of l ead concentrations predi cted to be measured in the Dow Pevely , Ursuline, Thurwell and Golf Course monitors
. The spatial interpolation is depicted in Figure 4 below. This analy sis is subject to the uncertainties associated with the ratio
- derived data, and additional uncertainties, such as whether the monitoring data used in the spatial interpolation which are the highest three
- month concentrations since 2001 , are repre sentative of post
- 2007 ambient concentrations, and whether spatial interpolation can reasonabl y estimate air quality around the Doe Run facilit y. In particular, the large range observed between the minimum and maximum ratio at the Dow
- Pevel y site, along w ith the results of the correlation anal ys is, indicate the high degree of variability

of lead concentrations between the two sites.10 Figure 4. Interpolation of Herculaneum Monitoring Data11

As discussed above, the four peripheral air mo nitors were discontinued after 2005 because these locations consistently

monitored attainment with the 1978 NAAQS. In January 2010, MDNR resumed lead air monitoring at locations near the Pevely and Ursuli ne locations. Three new locations named “Pevel y, ” “Pevel y North,” and “Ursuline North” replace the former monitoring locations. Preliminary

data obtained from MDNR indicate that for the first three rolling calendar quarter s of 2010 (January through May) , all three of the new peripheral monitors are below the standard. T he average concentration of ambient lead measured in the Ursuline North monitor ranged from 0.033 to 0.066 ug/m 3 , the average concentrations from the Pevely North monitor ranged from 0. 0 2 3 to 0. 0 30 ug/m 3 , and the average concentrations from the Pevely monitor ranged from 0.023 to 0.046 ug/m 3

. Itshould be noted that the Pevel y, Pevely North and Ursuline North monitors are “ neighborhood scale ” monitors which monitor an area between 0.5 and 4 kilometers (km). Uncertainties associated with the use of the 2010 monitoring data include the temporal limits of the data, as onl y three rolling quarter s of data have been collected thus far. Also, the data were collected during the winter and spri ng months in which the predominant wind direction was from the north, which likely would result in lower concentrations in the Pevely and Pevel y North monitor s and higher in the Ursuline North monitor. The Agency will continue to evaluate new data as it b ecomes available. In addition to ratio
- derived estimation and spatial interpolation of the monitoring data, MDNR also conducted extensive dispersion modeling of ambient lead concentrations presented in Figure 5. The city

limits of Herculaneum, the existing nonattainment boundary for the 1978 NAAQS , are depicted in blue; the orange blocks are incorporated areas of Pevel y to the north and Festus and Cry stal Cit y to the south. The blocks represent a mixture of sections that are identified b y township, range and section, and historic land grant areas. The dots on the figure denote the receptor grid used in the model, with each receptor color
- coded according to the concentrations of lead predicted. MDNR used AERMOD, EPA’s preferred dispersion model for the analy sis conducted. The modeling was performed for the time period of 2007

– 2009 using maximum production rates for the Herculaneum sme lter . It included o n - site meteorological data for ground
- level anal ys es, and data from the airport in Lincoln, I llinois for the upper atmospheric meteorological anal ys es. All of the meteorological data we re quality
- assured. Fugitive emissions from haul route traffic and bu ildings were included in the model. EPA conducted an independent review of MDNR’s model 6 and determined that while there are some areas for improvement, the modeling effort was comprehensive and done in accordance with EPA modeling guidance. Violations o f the NAAQS were predicted in all directions from th e facility with the highest estimated concentrations adjacent t o the facility . There is a sharp decrease in the lead concentrations as the distance from the facility increases, as would be predicted base d on the phy sical properties of lead. The mode l predicts potential violations of the 2008 NAAQS outside the existing and state recommended nonattainment boundary
. While it is acceptable to use modeled lead concentrations as one component of the anal ys is to determine the boundaries of the Jefferson County

nonattainment area, one significant uncertaint y with the modeling conducted by the State is the use of maximum allowable production levels under MDNR’s 2007 SI P
6 Mem orandum from Richard Daye, EPA, to Stephanie Doolan, EPA, dated April 30, 2010, re: Modeling Review of Doe Run Herculaneum and Buick/Viburnum, Missouri Areas.12 Figure 5. Herculaneum Modeled Lead Conce ntrations13

revision 3 rather than actual operating conditions. T he m odeled emissions were 158.66 TPY; whereas, the average actual emissions from 2007
- 2009 are 18.33 TPY (see Table 6 below)
. 2. Emissions and Emissions - Related Data Evidence of lead emissions sources surrounding a violating monitor are an important factor for determining whether a nearb y area is contributing to a monitored violation. For this factor, EPA evaluated county

level emission dat a for lead and population data
. Emissions data that appear on Figure 1 and in Table 5 below were der ived from the 2002 National Air Toxics Assessment ( http://www.epa.gov/ttn/atw/natamain/ )
. EPA recognize s that for certain sources , emiss ions may have changed significantl y since 2002 . For example, certain large sources of emissions in or near this area may have installed emission controls or otherwise significan tly

reduced emissions since 2002
. F igure 1 indicates two facilities in Pevely , Missouri, reporting lead emissions. The facility to the northwest of Herculaneum reporting lead emissions of 0.2 TPY is Saint Gobain Container, and the facility to the east of it identified in the legend on Figu re 1 as reporting less than 0.2 tons per year (TPY) lead emissions is Alcoa Composition. EPA verified emissions reported for these facilities with the 2007
- 2009 state emissions inventory (MoEIS). These facilities are approximately 1.5 miles from the vio lating monitor in Jefferson County . Neither of these facilities is believed to be influencing the monitors due to their distance and the quantity of emissions reported relative to the quantit y of the emissions from and the proximity

of the Herculaneum fac ility to the monitor . As a result, neither Alcoa nor S aint Gobain were considered further in this technical analy sis. There are approximately

20,000 airport facilities in the U.S. at which leaded aviation gasoline is consumed. Piston
- engine propeller ty pe airplanes use the lead aviation gasoline, so EPA and MDNR considered the potential for the Festus Memorial Airport to impact the Herculaneum nonattainment area. Based on the airport’s distance, 4 miles to the south, and the reported emissions, 40 pounds (lbs) of lead for 2008, EPA does not believe that Festus Memorial Airport contributes to the nonattainment area . Note that there are two airplane s ymbols on Figure 1; one is for Festus Memorial Airport and the second is for an associated heliport. T able 5 shows total emissions of lead (given in TPY ) for violating and potentially contributing counties in and around the Herculaneum nonattainment area and sources emitting greater than 0.5 ton per year of lead according t o the 2002 NATA and 2007
- 2009 MoE IS
. Based on the 2002 NATA and MoEIS, there are no other sources of lead emissions either within or outside Jefferson County

that are contributing to the nonattainment area for the 2008 L ead NAAQS.14 Table 5 . Lead Emissions County Facility in State

Recommended Nonattainment Area? Facility

– Total

Air Emissions 1 (tons per year) Facility Total County Lead Emissions (tons per year) Jefferson County Yes 41.1 1 Herculaneum Primary Smelter 41.3

Jefferson County No 0.2 Saint Gobain Container 41.3

Jefferson County No <0.2 Alcoa Composition 41.3

1

– National Air Toxics Assessment (NATA ) 2002 For comparison, EPA reviewed the emissions inventory information reported by

Doe Run for ye ars 2000

– 2002 in its responses to the State’s Emission Inventory Questionnaires. In formation for 2003

– 2009 is from MDNR’s MoEI S database. The emissions data ar e presented to examine the tre nds in emissions in compari son with the historic monitoring data discussed above. As Table 6 indicates, the lead emissions from the Herculaneum smelter have decreased significantly

from 2000

– 2009, corresponding with but proportionately larger than the significant decrease in lead pro duction. Table 6. Herculan eu m Smelter Production Year Lead Production (TPY) Lead Emissions TPY 1,2 2000 243,516 125.8 1 2001 203,262 110. 4 1 2002 143,265 58. 1 8 2003 150,550 25.1 2 2004 163,736 26.0 2 2005 154,969 28.1 2 2006 168,301 26.4 2 2007 136,573 21.81 2 2008 144,799 19.19 2 2009 114,298 13.99 2 1

- Emission Inventory Questionn aire reported by Doe Run Company 2 - Emissions reported from MoEIS database15

As a part of MDNR’s 2007 SI P revision 3 , modeling was conducted which forms the basis for the modeling used b y MDNR in its TSD 4 for its boundary recom m endation. In its modeling, MDNR used hourly

emissions by department developed by Doe Run 7 . The hourl y emissions study calculated emissions originating from the facilit y’ s lead concentrate unloa ding department, sinter plant, blast furnace (including main stack), drossing plant, and refinery strip rolling mill, including fugitive emissions from each of these departments. Fugitives from wind
- blown erosion from storage piles and re
- entrainment of dust from paved and unpaved haul routes were calculated as a separate category . Fugitive emissions from wind
- blown erosion from storage piles and deposition/re
- entrainment of lead
- contaminated dust along haul routes represents approximately

7% of the total facility

e missions . Due to the significance of this source of lead to the ambient air, it is important to note that the Jefferson County nonattainment area designation includes the main haul route s from the Herculaneum smelter facility to the city bounda ry . 3. Population Data Table 7 shows the 2008 pop ulation for Jefferson County , Missouri , which includes the proposed Herculaneum nonattainment area
. These data help assess the extent to which the concentration of human activities in the area and concentrat ion of population
- oriented commercial development may

indicate emissions
- based activity contributing to elevated ambient lead levels. This may include ambient lead contributions from activities that would resuspend lead that has been deposited on the ground or on other surfaces, such as fugitive emissions from the lead concentrate haul routes. Table 7 . Population Data County State Recommended

Nonattainment? 2008

Population 2008

Population Density (pop/sq mi) Population

Change 2000
- 2008 Population

% Change 2000
- 2008 Jefferson Co., Missouri Yes, partial 217,679 328 18,941 10 Source: U.S. Census Bureau estimates for 2008 ( http://www.census.gov/popest/datasets.html ) The areas surrounding the Herculaneum smelter are not more densely populated that surrounding areas such as Pevel y, Cr ystal City and Festus. The area may be characterized as predominantl y residential or light commercial/industrial. EPA does not believe that the po pulation data provided in the anal ys is of this factor affect the boundary recommendation.

7 “2005 Hourly Lead Emission Inventory for Doe Run’s Herculaneum, Missouri Smelter,” Shell Engineering and Associates, Inc., February 1, 2007.16

4. Growth Rates and P

atterns This factor considers population growth for 2000
- 200 8 in the area considered for the nonattainment designation. Table 8 below shows population, and population growth for Jefferson County , Missouri . All population data is from the U
. S
. Census Bureau http://www.census.gov/popest/counties/CO
- EST2008
- popchg2000_2008.html
. Table 8. Population and Percent Change
Location 2008 Population 2008 Population Density ( pop/sq mi ) Population

% change (2000
- 2008) Absolute change in

population Jefferson County, Missouri 217,679 328 10 10%

Jefferson County , Missouri had a moderate population growth between 2000 and 2008. Growth in new residential housing and commercial/light industrial facilities is evident, particularl y along the I
- 55 highway

corridor. This is most likely due to proximity

to St. Louis, Missouri. EPA has considered the population growth rate for this are a and does not believe that it affects the boundary determin ation. 5. 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 anal ys is and provided in Tables 5 and 6 above represent emissi ons levels taking into account an y control strategies implemented for the existing Herculaneum nonattainment area for the 1978 NAAQS
. As discussed above, there were SI P mandated controls place d on the facility in 2001 and state
- mandated controls in 2007 resulting in significant reductions in the Herculaneum smelter emissions, as demonstrated in Figure 6 below. Lead concentrations at the monitors are affected by the amount of lead produced and subsequent emissions from the Herculaneum smelter facility . While the 2001 (implemented in 2002) and 2007 controls do not bring Jefferson County in attainment with the 2008 NAAQS, it is apparent that lead concentrations measured in the monitors close to the smelter facility are greatly reduced. The other small lead sources in the area do not have regulatory controls for lead, but are not expected to be contributing to nonattainment in the area.17 Figure 6. Ambient Lead Concentrations at Herculaneum, 1995

– 2009

6. Meteorol

ogy For this factor, EPA considered data from National Weather Service instruments and other meteorological monitoring sites in the area. W ind direction data for the area are depicted in Figure 7 below. The three
- dimensional bar chart below shows the wind frequencies in eight dire ctions for the four seasons. The chart frequencies reflect the directions from which the winds come. Based on Figure 7, it may

be concluded that the wind originates predominatel y from the WNW in the winter months and from the SSW during summer months. These meteorological conditions are ty pical of areas along the Mississippi River valley . As discussed above, on
- site surface meteorological data were used in the lead concentration modeling analy sis. There are lead air monitors located both north and south of the smelter facility , so regardless of the season, monitoring is expected to detect lead in the ambient air. The Jefferson County nonattainment boundary recommendation is supp orted by the meteorological data. 0. 000 2. 000 4. 000 6. 000 8. 000 10. 000 12. 000 14. 000 16. 000Mar-95Sep-95Mar-96Sep-96Mar-97Sep-97Mar-98Sep-98Mar-99Sep-99Mar-00Sep-00Mar-01Sep-01Mar-02Sep-02Mar-03Sep-03Mar-04Sep-04Mar-05Sep-05Mar-06Sep-06Mar-07Sep-07Mar-08Sep-08Mar-09ug/m^3

End Month Lead Concent ration D ata in H erculaneum, M issouri

(3 - mo nt h Rol ling A

verage)

Bluf f High School Broad St. 2008 Standard 2001 SIP C ontrols Co mp le ted 2007 SIP C ontrol s Com pleted18

Figure 7. Herculaneum Historic Meteorological Data

Source: 1960
- 1992 Solar and Meteorological Surface Observation Netw ork information issued jointly by the U.S. Department of Commerce: National Climatic Data Center and the U.S. Department of Energy: National Rene wable Energy Laboratory 7. Geo graphy/Topography The geograph y/topography anal ys is evaluates the phy sical features of the land that might have an e ffect on the air shed and, therefore, on the distribution of lead over the proposed Herculaneum nonattainment area
. The Jefferson Count y nonattainment area lies in the Mississippi River valley which affects meteorological conditions, as discussed in Secti on 6 above. The area is characterized by wooded bluffs to the north and south of the facilit y, while the area west of the facility is residential with less topographic relief. To the east across the Mississippi River, the area is largel y crop land with f ew houses. EPA believes that the geographical or to pographical features of the area do not significantl y limit air
- pollution transport within its air shed , but rather that it creates a mild tunnel effect for winds originating from the north in winter and from the south in summer months . Therefore, this factor did not play a significant role in determining the nonattainment boundary
.19

8. Jurisdictional boundaries Existing jurisdictional boundaries may be helpful in articulating a boundary for purposes of nonattainment designations, and for purposes of carry ing 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. The c ity limits of Herculaneum, Missouri, is the jurisdictional boundary which defines the nonattainment area. Areas to the north include the incorporated limits of Pevel y, and areas to the south include Festus and Cry stal City . The orange lines on Figure 2 indicate a number of jurisdictional bo undaries for the areas to the north and south of Herculaneum. These areas include townships, sections, and land grant designations. These jurisdictional boundaries were considered in determining the appropriate boundary
. 9. Other Relevant Information EPA received additional information from the State relevant to establishing a nonattainment area boundary for this area. As discussed in Section 1, Air Quality , above, MDNR submit ted modeling analy sis and spatial interpolation of air monitoring data in support of its boundary recommendation. EPA considered this information and conducted an independent anal ys is in making its boundary determin ation for the Herculaneum lead nonattainment area. Summary EPA i s designat ing as nonattainment that portion of Jefferson County Missouri which coincides with the Herculaneum city limits as identified in Figures 1 and 2 as the nonattainment area for the 2008 Lead NAAQS . Th e Herculaneum city limits include the same area previousl y designated as non attainment for the 1978 Lead NAAQS. Five air quality

monitors operated by

MDNR in Jefferson Count y surrounding Doe Run’s Herculaneum smelter facility show violation s of the 2008 Lead NAAQS based on 2007
- 2009 air quality

data. Therefore, a nonattainment designation is required for all or some of Jefferson County . EPA has considered all eight factors and other relevant information submitted by MDNR to help determine an appropriate boundary. Other relevant information considered includes ratio
- derived e stimation and spatial interpolation of historic monitoring values at locations of discontinued monitors north and south of the existing lead nonattainment area for the 1978 NAAQS and dispersion modeling conducted by MDNR. In addition to the historic moni t oring data, EPA considered preliminary data from January

through March 2010 for three new monitors placed at the locations of the historic Dow Pevel y monitor to the north and the Ursuline monitor to the south. T he available monitoring data indicate that the existing nonattainment boundary for the 1978 NAAQS captures the existing monitored violations . It also includes all the significant lead emitting facilities and activities within the county : the Doe Run primary smelting facilities and20

related operatio ns. EPA has considered MDNR’s spatial interpolation and concludes that the uncertainties associated with this analy sis are so significant that the interpolation does not provide a reliable basis for designations
. EPA has a high degree of confidence in th e use of the dispersion model to characterize lead concentrations in ambient air . However, because the model inputs utilized maximum emissions estimates at this facility , EPA believes the model ing results likely overestimate the extent of the 2008 NAAQS v iolations, al though EPA has very little information with which to judge the degree of overestimation . Also, as discussed in the text, EPA notes that there are uncertainties associated with the use and interpolation of the historic monitoring data from the peripheral monitoring sites. Given the uncertainty in the modeling results , EPA is relying more upon the monitoring data than the modeling to inform the boundary
. In summary , considering all of the technical information presented, and placing gr eater emphasis on the monitoring data, EPA is designating as nonattainment the portion of Jefferson County consistent with the Herculaneum city limits as the 2008 NAAQS nonattainment boundary
. Based on its consideration of all the relevant, available info rmation, 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 nearb y area that does not meet) the 2008 Pb NAAQS. As discussed above, due to the uncertaint y in the interpolated monitoring and modeling data for the areas outside the Herculaneum cit y limits, EPA intends to allow time to collect and evaluate additional data from the new monitoring sites, and conduct additional analy ses , as appropriate
. The area will be re
- evaluated in the second round of designations taking into consideration all newly available data and information.21

Iron, Dent and Reynolds Counties, Missouri Nonattainment Area As discussed in the Introduction, Doe Run also owns and operates the Buick secondary smelter facility near Bixby , Missouri in Iron County . The Buick facility initially began ope ration as a primary smelter in 1968. Since 1991, the Buick facility has operated as a secondary smelter for recy cling lead, prim aril y from lead
- acid storage batteries. Buick is also the only location in the U.S. for recy cling lead from cathode ray tubes from televisions and computer monitors. In 1991, western Iron County was designated nonattainment, effective in 1992. In Octo ber 2000, western Iron County

was redesignated as attaining the 1978 Lead NAAQS. In August 2004, the Buick facility ’s maintenance plan was approved by EPA by final rulemaking. Iron County has been in attainment of the 1978 NAAQS until the fourth quarter of 2008. Following the 2008 exceedences of the 1978 Lead NAAQS, contingency measures identified in the facility ’s approved maintenance plan have been implemented. Doe Run also operates a number of mining and milling facilities in the vicinity of the Bui ck facility including the Buick, Brushy Creek, Fletcher and Sweetwater mines and mills. Figure 8 is a map of the area anal yzed showing the location and design value of air quality monitors
. T hese operations extend in to portions of Iron, Dent and Reynol ds C ounties in Missouri. An additional source of lead emissions in Iron County is Doe Run’s Glover facilit y , a former primary smelter , where lead ore and zinc and copper concentrate handling activities are currentl y conducted. The Glover facility began operations in the 1970’s and is located in the southeastern portion of Iron County . It was designated nonattainment for the 1978 lead NAAQS in 1992 and ceased smelting operations in 2003, after which it has been in care and maintenance. Doe Run no longe r has an operating permit to conduct py ro - processing at this facilit y. EPA designated eastern Iron County , the portion including the Glover facility , in October 2004 as attaining the 1978 L ead NAAQS. Current monitoring data in the vicinity of Glover are below the new standard. The State has recommended the area surrounding the Glover facility for attainment of the 2008 Lead NAAQS. EPA is o nly designating areas with monitored violations, and will address all other areas in a second phase, scheduled to be completed in October 2011. The anal ys is below includes a discussion of the Glover facility ’s lack of contribution to the violating monitors elsewhere in Iron County
. On December 28, 2009 , the State of Missouri recommended that portions of western Iron, Dent and Rey nolds Counties in Missouri, identified in Figures 8 and 9, be designated as “nonattainment” and “un classifiable” for the 2008 L ead NAAQS based on air quality data from 2007 through 2009 . The state’s recommendation 1 was based on anal ys is of monitoring and modeling data
. Based on EPA's technical analy sis described below, EPA is designat ing portions of Iron, Dent and Rey nolds Counties as nonattainment for the 2008 L ead NAAQS , based upon currentl y available informatio n. The area recommended b y MDNR as “unclassifiable” on Figure 9 will be considered b y EPA in its October 2011 designations.22



### Figure 8. Buick/ Viburnum Tr end (Dent, Ir on & Reynolds Counties, MO)

* Sources that are not labeled emitted less than 0.05 tpy
.23

Figure 9. Iron, Dent & Reynolds County Lead Nonattainment Recommendation24

1. Air Quality Data This factor considers the Lead Design V alues (in μg/m 3 ) for air qualit y monitors in western Iron County at the Buick secondary

smelter and in the surrounding area, and southeastern Iron County around the Glover facilit y, based on data from 2007
- 2009. The monitors used for determining compliance with the regulatory standard are FRM or FEM monitors located in Iron County
. A s discussed above, a monitor’s design value indi cates whether that monitor attains a specified air quality

standard ; in this case the 2008 lead NAAQS
. The 2009 Lead NAAQS Design V alues for the monitors in Iron Count y and s urrounding area are shown in Table 9
.

Table 9 . Iron, Dent and Reynolds Counti es Air Quality Data County State Recommended Nonattainment? Monitor Name Lead Design Value, 2007
- 2009 (μg/m 3 ) Iron, Dent & Reynolds Yes (partial) Buick South 2.46 Iron No Post Office 0.13 Iron County , Missouri shows a violation of the 2008 L ead NAAQS for the monitor listed in Table 9 above in the vicinity of the Buick smelter, mine and milling operations
. Because the county contains at least one ambient monitor that has a Lead Design Value that is above 0.15 μg/m 3 , the boundary

of the nonattainment area is presumed to be the county
. The highest measured design value for monitors in the vicinity of the Glover facility

is also included in Table 9 above. The air monitoring data from monitors in the vicinity of the Glover facility show attainment with the 2008 NAAQS for 2007
- 2009. Fi gure 10 depicts the active air monitors, Buick North and South, that currently exceed the 2008 NAAQS, as well as the new monitors for the mining and milling operations that began operating in January

2010. Historically , there were two additional air monit ors located to the northwest of Buick that also monitored violations of the 2008 NAAQS. These monitoring locations were discontinued in 2001. The Buick North and South monitor s recorded about the same concentrations of lead for the 2007

– 2009 time perio d , with the highest concentration of 2.46 ug/m 3 detected in the October

– December calendar quarter of 2008 at the Buick South monitor
. This exceedence set the design value.25 Figure 10. Iron, Dent, and Reynolds County Air Monitor Locations26

MDNR used AERMOD to conduct a dispersion model anal ys is to predict lead concentrations in the vicinity

of the Buick smelter, mine and mill and for the other mining and milling operations in the Viburnum Trend area. The maximum permitted emissions were used to model the Buick smelter emissions. Fugitive emissions from haul route traffic and buildings were included in the model. In addition, MDNR observed a “stack” test conducted by Doe Run’s contractor at one of the mine sha ft vents to gather data to represent emissions from the mines for use in the model. The Buick/Viburnum Trend modeling results are depicted on Figures 11 and 12 below. The Buick/Viburnum Trend modeling indicates that predicted violations of the 2008 NAAQS are within the propert y boundaries for the mining and milling operations, with the exception of the Buick mine and mill and one receptor north of the Fletcher mine and mill. The model predicts 2008 NAAQS exceedences between the Buick smelter and the Bu ick mining and milling operations. MDNR conducted further anal ys is of the potential for contribution from these sources of lead emissions to one another. The anal ys is indicates that the Buick smelter, mine and mill (modeled together) contributes 2.5% to the predicted concentrations in the vicinity of the other mine and milling operations (Brushy Creek, Fletcher, and Sweetwater). The anal ys is also indicates that the other mine and milling operations contribute less than 1% to the predicted concentratio n for the Buick smelter, mine and mill. EPA also conducted an independent review of the Buick/Viburnum Trend modeling results and the review is discussed in the Memorandum dated April 30, 2010, previously referenced. 6 The modeling performed for the Buick /Viburnum used meteorological data obtained from Fort Leonard Wood, which is about 35 miles west of the Buick smelter facility
. The upper air data were obtained from the NWS radiosonde site located near Springfield, Missouri. The modeled period extended from August 1, 2005 to December 31, 2007 . Fugitive emissions for the mining and milling operations represented a large portion of the source characterization. 2. Emissions and Emissions - Related Data Evidence of lead emissions sources surrounding a violating monitor are an important factor for determining whether a nearb y area is contributing to a monitored violation. For this factor, EPA evaluated county

level emission data for lead and population data . Emissions data that appear on Figure 8 were der ived from the 2002 National Air Toxics Assessment, which is the most up
- to - date version of the national inventory available to the public when these data were compiled for the designations process in 2009
. See http://www.epa.gov/ttn/atw/natamain/
.27 Figure 11. Iron, Dent & Reynolds Counties Modeling Results

– North28 Figure 12 . Iron, Dent & Reynolds Counties Mode ling Results

– South

2.29

Table 10 shows total emissions of lead (given in TPY ) for violating and potentially contributing counties in and around the recommended Iron, Dent and Rey nolds Counties nonattainment area and source s emitting greater than 0.5 ton per y ear of lead according t o NATA , cross
- referenced with the 2007
- 2009 state emissions inventory , MoEI S
. Based on the 2002 NATA and MoEIS, there are no other sources of lead emissions either within or outside Iron, Dent and Rey nolds Counties that are contributing to the recommended nonattainment area for the 2008 Lead NAAQ S. Table 10. Lead Em issions for Iron, Dent and Reynolds Counties County Facility in State

Recommended Nonattainment Area ? Facility

– Total Ai r

Em issions (tons per year) Facility Total County Lead Em issions (TPY) ) Iron, Dent & Reynolds Yes 12.4 1 Buick secondary Sm elter, Mine/Mill 12.5 1

Iron No 0.12 1 Glover former primary smelter 12.5 1

Dent Yes 0.018 2 Buick secondary Sm elter 0.018 2
Reynolds No 2.9 2 Fletcher Mine/Mill 5.4 2
Reynolds No 1.9 2 Brushy Creek Mine/Mill 5.4 2
Reynolds No 0.6 2 Sweetwater Mine/Mill 5.4 2

1

– National Air Toxics Assessment (NATA ) 2002 2

– MoEIS, 2008 3. Population Data Table 11 shows the 2008 pop ulation for Iron, Dent and Rey nolds Counties in Missouri , which includes the Iron, Dent and Rey nolds Counties nonattainment area
. These data help assess the extent to which the concentration of human activities in the area and concentra tion of population
oriented commercial development may indicate emissions
- based activity contributing to elevated30

ambient lead levels. This may include ambient lead contributions fr om activities that would resuspend lead that has been deposited on the gro und or on other surfaces, such as fugitive emissions from the lead concentrate haul routes and lead ore and zinc and copper concentrate handling. Table 11 . Population Data County State Recommended

Nonattainment? 2008

Population 2008

Population Density (pop/sq mi) Population

Change 2000
- 2008 Population %

Change 2000
- 2008 Iron Co., Missouri Yes, partial 9,918 18
- 714
- 7 Dent Co., Missouri Yes, partial 15,199 20 265 2 Reynolds Co., Missouri Yes, partial 6,388 8
- 329
- 5 Source: U.S. Census Bureau estimates for 2008 ( http://www.census.gov/popest/datasets.html ) The areas surrounding the Buick secondary smelter and Viburnum Trend are not densel y populated and is con sidered rural. EPA does not believe that the population data provided in the anal ys is of this factor a ffects the boundary determin ation. 4. Growth Rates and Patterns This factor considers population growth for 2000
- 200 8 in the area considered for the nonattainment designation. Table 12 below shows population, and population growth for Iron, Dent and Rey

nolds Counties in Missouri . All population data is from the U
. S
. Census Bureau http://www.census.gov/popest/counties/CO
- EST2008
- popchg2000_2008.html
. Population declines were observed for Iron and Reynolds Counties from 2000

– 2008, while Dent County grew a modest 2%. As stated above, this area of Missouri is rural and so little population growth or decline is ty pical
. EPA has considered the population growth rate for this area and does not believe that it affects the boundary determin ation. 5. Emiss ions 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 anal ys is and provided in Table 10 above represent emissi ons levels taking into account an y co ntrol strategies implemented which previously

brought the western Iron Count y nonattainment area into attainment in 2000, and as a part of the 2004 maintenance plan for the Buick facility
.31

As discussed above, the Glover facility is no longer permitted f

or py ro - processing operations; the emissions from the facility from 2003 to the present are fugitive emissions from handling lead ore and zinc and copper concentrate. 6. Meteorol

ogy For this factor, EPA considered data from NWS instruments and other meteorological monitoring sites in the area. W ind direction data for the area are depicted in Figure 13 below. The three
- dimensional bar chart above shows the wind frequencies in eight dire ctions for the four seasons. The chart frequencies reflect the directions from which the winds come. Based on Figure 13, it may

be concluded that the wind originates predominatel y from the WNW in the winter months and from the SSW during summer months. These meteorological conditio ns are similar to that found at Herculaneum (Figure 7), with the exception of the influence of the river valley observed in the on
- site monitors at Herculaneum. As discussed above, meteorological data from Fort Leonard Wood which is approximately 35 miles west of Buick smelter facility were used in the lead concentration modeling analy sis. There are lead air monitors located both north and south of the Buick smelter facility , and new monitoring locations at Buick, Brush y Creek, Fletcher and Sweetwater min e and milling operations to the south of Buick. The additional new monitors should provide sufficient information to determine NAAQS compliance in areas for which there is little or no historic data. The Iron, Dent and Reynolds Counties nonattainment boundary determin ation is supported by the meteorological data.32

Figure 13 . Buick/Viburnum Trend Meteorological Data

Source: 1960
- 1992 Solar and Meteorological Surface Observation Netw ork information issued jointly by the U.S. Department of Commerce : National Climatic Data Center and the U.S. Department of Energy: National Rene wable Energy Laboratory 7. Geo graphy/Topography The geograph y/topography anal ys is evaluates the phy sical features of the land that might have an a ffect on the air shed and, therefore, on the distribution of lead over the proposed Iron, Dent and Rey nolds Counties nonattainment area
. The Iron, Dent and Rey

nolds Counties nonattainment area is in a rural portion of southeastern Missouri in the Ozarks region . The area is characteristically wooded and has significant topographic relief. USGS topographic maps indicate as much as 200 feet of relief in this area. Topograph y most likely influences ambient air transport and weather patterns. Topograph y and regi onal weather patterns are accounted for in the dispersion modeling conducted by MDNR; therefore, this factor played an indirect role in establishing the nonattainment boundary in western Iron, Dent and Rey nolds Counties. The Glover facility

in eastern I ron Count y lies in a valley and is located approximately 40 miles to the east of the Buick smelter, mine and mill. Due to the geographic distance of the Glover facility from the nonattainment area, and because the Glover facility lies within a valley , EPA believes that the emissions from lead handling activities at the Glov er facility do not contribute to the Iron, Dent and Reynolds Counties nonattainment area.33

8. Jurisdictional boundaries Existing jurisdictional boundaries may be helpful in determining a boundary for purposes of nonattainment designations, and for purposes of carry ing 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 the area surr ounding the Buick smelter, there is no clear jurisdictional boundary which defines the nonattainment boundary . The Buick smelter lies in Iron County ; however, the proposed nonattainment area extends to a small portion of Dent County to the east and Rey

nol ds County

to the south. The Buick mine and milling operations extend into Rey nolds County , Missouri. The air monitoring data from the Buick South monitor and the modeling indicate that it is appropriate to include portions of Reynolds County in the lead nonattainment area. The nonattainment area therefore must be described officiall y b y township, section and range, consistent with the State’s designation recommendation. 1 9. Other Relevant Information EPA received additional information from the State relevant to establish a nonattainment area boundary for portions of Iron, Dent and Rey nolds Counties in Missouri. As discussed in Section 1 above, MDNR submitted the results of a dispersion model analy sis in support of its boundary determin ation. EPA considered this information and conducted an independent anal ys is in making its boundary determin ation for the Iron, Dent and Rey nolds Counties nonattainment area. Summary EPA is designating portions of Iron, Dent and Reynolds Counties in Missouri which include Doe Run’s Buick smelter and Buick mining and milling operation as identified in Figures 8 and 9 as the nonattainment area for the 2008 Lead NAAQS
. Two air qualit y monitors in Iron Count y one no rth and one south of Doe Run’s Buick secondary smelter facilit y show violation s of the 2008 Lead NAAQS based on 2007
- 2009 air quality data. Therefore, a nonattainment designation is required for all or some of Iron County . The relevant information , in cluding monitoring and modeling results, supports a partial county designation for Iron County

and the expansion of the boundary into portions of Dent and Rey nolds Counties. Based on its consideration of all the relevant, available information, as describ ed 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 nearb y area that does not meet) the 2008 Pb NAAQS. This area will be re
- evaluated in the second roun d of designations, taking into consideration all newly available data and information.34

Definition of important terms used in this document: Designated “unclassifiable”

– an area where EPA could not determine if there was a violation of the 2008 Lead NA AQS because there was incomplete air quality data for a three year period either in 2006
- 2008 or 2007
- 2009. Designated “attainment”

– an area which EPA has determined that based on the most recent three ye ars of certified air quality data from 2006
- 2008 or 2007
- 2009 has no violations of the 2008 L ead NAAQS during 36 consecutive valid three
- month rolling site averages ; and EPA does not believe that the area contributes to a violation of the 2008 Lead NAAQS in a nearb y area. Designated nonattainment area

– an area which EPA has determined, based on a State recommendation and/ or on the technical anal ys is included in this document, has a violation of the 2008 Lead NAAQS for the most recent three consecutive y ears of quality
- assured, certified air quality

data
. Further, a site does not have to monitor for three full calendar y ears in order to have a valid violating design value; a site could monitor just three months and still produce a valid (violating) design value. Prior nonattainment area

– an area that is currently designated as nonattainment or maintenance for the 1978 L ead Standard (including both current nonattainment areas and maintenance areas). Recommended nonattainment area

– an area a State or Tribe has recommended to EPA be designated as nonattainment. Violating monitor

– an ambient air monitor whose design value exceed s 0.15 micrograms per cubic meter (ug/m3) . As described in Appendix R of part 50, a violation can be based on either Pb
- TSP or Pb
- PM10 data and onl y three months of data are necessary to produce a valid violating design value. 1978 Lead NAAQS

– 1.5 μg/m 3 , National Ambient Air Quality Standard for lead promulgated in 1978. Based on Pb
- TSP indicator and averaged over a calendar quarter. 2008 Lead NAAQS - 0.15 μg/m 3 , 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.