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--------------------------------------------------------------------------------------------------------------------- Technical Support Do cument Definition of important t erms used in this document: 1) Designated “unclassifiable”

– an area where EPA could not determine if there was a violation of the 2008 Lead national ambient air quality standard (NAAQS ) or a contribution to a violation in a nearb y area, because there was insufficient air quality data for both 2006
- 2008 and 2007
- 2009 and where additional monitoring data for 2010 could not result in a different designation
. 2) Designated “attainment”

– an area which EPA has determined , base d on the most recent 3 ye ars of certified air quality data from 2006
- 2008 or 2007
- 2009 , has no violations of the 2008 Lead NAAQS during 36 consecutive valid 3
- month site means ; and which EPA has further determine d does not contribute to a violation of the 2008 Lead NAAQS in a nearb y area and that additional monitoring data from 2010 could not result in a different designation
. 3 ) 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 during the most recent three consecutive years of quality
- assured, certified air quality

data. 4 ) Prior nonattainment area

– an area that is currently designated as nonattainment or maintenance for the 1978 Le ad NAAQS (including both current nonattainment areas and maintenance areas). 5 ) Recommended nonattainment area

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

– an ambient ai r monitor whose design value exceed s 0.15 micrograms per cubic meter ( μ g/m 3 ) . As described in Appendix R of part 50, a violation can be based on either lead
- total suspended particles ( Pb
- TSP ) or Pb
- PM 10 data and only three months of data are necessary to p roduce a valid violating design value. 7 ) 19 78 Lead NAAQS

– 1
. 5 μg/m 3 , N ational Ambient Air Quality Standard for lead promulgated in 1978. Based on Pb
- TSP indicator and averaged over a calendar quarter. 8 ) 2008 Lead NAAQS - 0. 1 5 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
- PM 10 data may be used in limited instances , including to show nonattainment.2 Alabama Area Designations For the 2008 Lead National A mbient Air Quality Standard s 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 national ambient air quality standard (NAAQS ) and those nearby areas that contribute to violations. The table below identifies the counties or portions of counties (or tribal areas) in Alabama that EPA is designat ing “nonattainment” for the 200 8 lead national ambient air quality standard (2008 Lead NAAQS)
. Table 1 : Area Designation Area (listed alphabeticall y) Al a bama Recommended Nonattainment Counties EPA’s Designated Nonattainment Counties Nonattainment area for 19 78 Lead NAAQS Troy , Alabama None 1 Pike (partial) No Technical analysis for Troy Introduction Th is technical anal ys is for the Tro y Area identifies the partial county with a monitor that violate s the 2008 Lead NAAQS for contributions to lead concentrations in the area. EPA has evaluated Troy , Alabama based on the weight of evidence of the following factors recommende d 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 rates and patterns and emissions controls;

 Meteorology

(weather/transport patter 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 submitt ed to or collected b y EPA (e.g., modeling where done appropriatel y)
.

1 In Alabama’s October 26, 2009, revised letter of recommendation, the State requested a portion of Pike County, within a 0.8 mile (or 1.3 kilometers (km)) radius from a center point at latitude 31.78627106 and longitude 85.9786222 8, which fully includes the Sanders Lead Facility, be designated as “unclassifiable.” However, if EPA determines this request to be unfeasible, Alabama requests for the portion of Pike County within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Facility, be designated as “nonattainment.”3

Figure 1: Pike County

Area of Troy , Alabama

Figure 2: Tro y, Alabama Area and Surrounding Counties4

Figure s 1 and 2 are map s of the area anal yz ed sho wing the location and design value of the air quality monitor in the area, the counties surrounding the violating air quality monitor , and the state’s recommended area to be designated . The violating monitor in the Troy Area is located in Pike County , in close proximity to Sanders Lead Company , shown in Figure 1. The Tro y Area was not designated nonattainment for the 1978 Lead NAAQS. 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
. O n October 1, 2009 , Alabama recommended that a portion of Pike C ounty be designated as “ nonattainment ” for the 2008 Le ad NAAQS b ased on air quality data from 2006
- 2008
. Their recommendation was based on data from Federal Reference Method monitors located in the state, as well as their own anal ys es of the recommended factors and air quality modeling
. Subsequently , on October 26, 2009, EPA received a revised letter of recommendation from Alabama with a request to designate a portion of Pike County as “unclassifiable.” Based on EPA's technical analy sis described below, EPA is designating the entire portion of Pike County , Alabama, within a 0.8 mile (1.3 km) radius from a center point at latitude 31.78627106 and longitude 8 5.97862228, which fully includes the Sanders Lead Facility , a s nonattainment for the 2008 Lead NAAQS as the Tro y nonattainment area , based upon currently available information
. Th is county is listed above in Table 1
. Detailed Assessment Air Q uality D ata This factor considers the l ead design values (in μg/m 3 ) for the air quality monitor in Pike County in the Troy Area, and the surrounding area based on data for the 200 7
- 200 9 period. A monitor’s design value indicates whether that monitor attains a spec ified 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/m 3

. A design value is only valid if minimum data completeness criteria are met. A l ead design value that meets the NAAQS is generall y considered valid if it encompasses 36 consecutive valid 3
- month site means (specifically for a 3
- ye ar calendar period and the two previous months)
. For this purpose, a 3
- month site mean is valid if valid data were obtaine d for at least 75 percent of the scheduled monitoring days in the 3
- month period. A l ead 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 three full calendar ye ars in order to have a valid violating design value; a site could monitor just three months and still produce a valid (violating) design value
. The 2008 Lead NAAQS design values for Pike County in th e Tro y Area are shown in Table 2
.5

Table 2 . Air Quality

Data County State

Recommended Nonattainment Monitor Name Monitor Air Quality Sy stem ID Monitor Location Lead Design Value, 2006
- 2008 (μg/m 3 ) Lead Design

Value, 2007
- 2009 (μg/m 3 ) Pike Cou nty, AL No 2 011090003 Henderson Road 1. 35 1.35 01109000 6 Henderson Road 0.50 3 0.31 Monitors in Bold have the highest design value in the respective county. Pike County show s two monitor s violating the 2008 Le ad NAAQS
. Therefore some area in this C o unty and possibly

additional areas in surrounding counties must be designated nonattainment
. However, the absence of a violating monitor alone is not a sufficient reason to eliminate nearb y counties as candidates for nonattainment status. E ach area has b een evaluated based on the weight of evidence of the eight factors and other relevant information. The violating monitor s located in Pike County are in close proximity to Sanders Lead Company, Sanders Road, Tro y, Alabama. The monitoring objective, according to the EPA monitor locator, is to determine the highest concentration of l ead. The emissions from Sanders Lead Company and other area lead emitters will be discussed in the corresponding section. The S tate of Alabama provided similar information from these monitors in their October 2009 letter . The S tate information is consistent with the data provided by EPA , although the reported results are slightly

different because of different reporting periods used. In addition, Alabama provided data from m onitors owned b y Sanders Lead Company sited near this facility. These monitors (Anderson and Murphree) are at a slightly greater distance from the facility and located to the southwest and northwest of the facility . The reported maximum rolling three month average lead concentrations from these sites are 0.31 μ g/m 3 and 0.19 μ g/m 3 for the period from November 2005 to August 2009. These values are also in excess of the new l ead NAAQS of 0.15 μg/m 3

. Emissions and Emissions- Related Data Evidence of lead emi ssions 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
.

2 In Alabama’s October 26, 2009, revised letter of recommendation, the State requested a portion of Pike County, within a 0.8 mi le (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Facility, be designated as “unclassifiable.” However, Alabama mentioned in their letter that if EPA determines this request to be unfeasible, Alabama requests for the portion of Pike County within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Facility, be designated as “nonattainment.” Both monitors are within the state’s recommended boundaries. 3 This monitor ceased operation in August of 2007. The maximum 3
- mo nth rolling average was calculated using data for the three month periods ending from January 2006 through August 2007.6

Emissions E missions data were derived from the 2005 National Emissions Inventory (NEI), version 2 , which is the most up
- to - date version of the national inventory available when these data were compiled for the designations process in 2009. See http://www.epa.gov/ttnchie1/net/2005inventory .html
. EPA recognize s that for certain counties, emissions may

have changed since 2005. For example, certain large sources of emissions in or near this area may

hav e installed emission controls or otherwise significantly reduced emissions since 2005. Some States provided updated information on emissions and emission controls in their comments to EPA. Alabama provide d emissions information for the Troy Area from the 2005 NEI , therefore EPA relied on the 2005 NEI emissions data. These data are provided in Table 3
. Table 3 shows total emissions of l ead (given in tons per year (tp y) ) for violating and potentially contributing counties in the Tro y Area with s ources emi tting (or anticipate to contribute) greater than 0. 1 t py of lead according to the 2005 NEI. There are approximately

20,000 airport facilities in the U.S. at which leaded aviation gasoline is consumed. To evaluate the potential impact of emissions at an d near these facilities, EPA recommends that States use the draft 2008 NEI. Table 3
. Lead Emissions County Facility in State

Recommended Nonattainment Area ? Facil i ty

Name Facility

Location Total Lead Emissions

( tpy) Pike County No* Sanders Lead Com p any 100 Sanders

Road, Troy 4. 44
* InAlabama’s October 26, 2009, revised letter of recommendation, the State requested a portion of Pike County , within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, wh ich fully includes the Sanders L ead Facility , be designated as “unclassifiable.” However, Alabama mentioned in their letter that if EPA determines this request to be unfeasible, Alabama requests for the portion of Pike County within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Facility , be designated as “nonattainment.” The facility

is within the state’s recommended boundary
. A ccording to the 2005 NEIdata, Pike County has one source (Sanders Lead Company) emitting at or above 0 .1 ton per year. There are no other stationary sources emitting greater than 0.1 tpy located within Pike County , nor any m ajor sources of lead in the counties surrounding Pike County
.7

T abl e 4: Airport Facilities Using Leaded Aviation Gas in Pike County City Facility Name Ty pe 2008 draft

NEI (tpy) Distance to Violating

Monitor (km) Pike County Troy Muni cipal Airport 0.1 8.83 There is one airport facility with aircraft using leaded av iation gas in Pike County that emits at or above 0.1 ton per ye ar. Troy Municipal Airport is located approximately 8.83 km from Sanders Lead Company. Population Data Table 5 shows the 200 8 population for each county in the area that was evaluated, as well as the population density

for each county in that area. These data help assess the extent to which the concentration of human activities in the area and concentration of population
- oriented commercial development may indicate emissions
- based activ ity contributing to elevated ambient l ead levels. This may

include ambient lead contributions from activities that would disturb lead that has been deposited on the ground or on other surfaces. Reentrainment of historically deposited l ead is not reflecte d in the emissions inventory
. Table 5: Population Data County State

Recommended Nonattainment? 2008

Population 2008

Population Density (pop/sq mi) Population

Change 2000
- 2008 Population

% Change 2000
- 2008 Pike County No 4 30.381 45 647 2 [Source of dat a: U.S. Census Bureau estimates for 200 8 (http://www.census.gov/popest/datasets.html ) and estimation of the area of U.S. Counties] Growth rates and patterns Pike County

shows a population chan ge of two percent betw een 2000 and 2008. EPA has considered the population growth rate for this area and does not believe that it affects the boundary recommendation.

4 In A labama’s October 26, 2009, revised letter of recommendation, the State requested a portion of Pike County, within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Fac ility, be designated as “unclassifiable.” However, Alabama mentioned in their letter that if EPA determines this request to be unfeasible, Alabama requests for the portion of Pike County within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Facility, be designated as “nonattainment.”8

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 Table 3 represent emissi ons levels taking into account an y control strategies implemented in the Tro y area before 2005 on stationary

sources. As me ntioned above, o n October 26, 2009, EPA received a revised letter of recommendation from Alabama with a request to designate a portion of Pike County as “unclassifiable.” This letter stated that the Alabama Department of Environmental Management (ADEM) ha s met with the source in Pike County to discuss potential mitigation measures for achieving compliance with the new l ead standard. According to Alabama’s letter, the source has shown willingness to enclose the processes at the facility in order to abate l ead emissions. This method has proven successful when used at other similar facilities, and should greatly reduce ambient l ead concentrations if implemented at Sanders Lead in Pike County, Alabama. Meteorology (weather/transport patterns) For this fac tor, EPA considered data from National Weather Service (NWS) instruments and other meteorological monitoring sites in the area , usually associated with major airport operation
. A three
- dimensional bar chart shows the wind frequencies in eight directions, for the four seasons, based on thirty two years of historical data 5 for the Troy Area . These historical 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 violating monitor location, in the season of the violation.

5 This data was 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.9

Figure 3: Pike County

Historical Wind Direction Frequency

As seen in Figure 3 above, the predominant wind direction in the Winter season is originating from th e West/Northwest ( WNW ) , while in the Spring season it is from the South/Southwest ( SSW ) , in the Summer it is from the East/Southeast ( ESE ) , and in the Autumn it is from the East/Northeast ( ENE ) , indicating that lead sources located in any direction from th e monitoring site in Troy

could influence the monitored ambient air concentrations during different time periods. For each air quality

monitoring site, EPA also developed a “ wind rose,” which provides information about how wind speed and direction are distributed at the NWS monitoring station during the 30
- year time period. The “spokes” on the diagram indicate the frequency of winds blowing FROM a particular direction. The length of a spoke shows the amount of time (in percentage) that the wind blows f rom that direction. Each concentric doted
- line circle on the diagram represents increasing frequencies as you move out from the center. The spokes also provide information about the speed of the winds blowing from that direction. Each spoke is broken into discrete frequency categories that are color
- coded to indicate the percentage of time that wind speeds are within that category (e.g., for winds blowing from the East, approximately three percent of the time the wind speeds are between 2.1

– 3.6 meters/ second (m/s) ).10

Figure 4: Tro y Wind Rose; Montgomery Airport

Annual Wind Rose

– 30 years (1961
- 1990) Figure 4 provides an annual wind rose diagram for the Tro y Area
. The wind rose was generated from 30 years (1961
- 1990) of wind speed and wind dire ction data collected at the NWS meteorological monitoring station located at the Montgomery Airport (NWS Station No. 13895). This station has the most representative long
- term record of wind data for area near Montgomery , including the lead monitoring sit e located in the Tro y Area
. The Tro y Area wind rose is consistent with the wind direction bar chart in Figure 3 above and indicates that the wind does not blow from a strongl y predominant wind direction. The winds blow from each direction at least three percent of the time , and from most directions more than five percent of the time . The highest frequencies of winds are from due East (approx eight percent), due North (approx seven percent), and due South (approximately seven percent). The wind speeds al so vary

with no strongl y predominate speed category either. However, more than 50 percent of the time, the wind speeds are less than 3.6 m/s. It is also important to note that winds are classified as calm (less than 0.5 m/s) approximately 15 percent of the time. The wind rose indicates that lead sources located in any direction from the monitoring site in the Tro y Area11

could influence the monitored ambient air concentrations during different time periods. Also, the higher frequency

of low to moderate wi nd speeds would indicate that air emissions sources located closer to the monitor have a larger influence than those located more distant from the monitor. EPA considered this historical wind direction and wind speed data to show evidence of the potenti al transport patterns for lead emissions sources located upwind and/or in close proximity to that of a violating mo nitor to contribute to ambient l ead levels at the violating monitor. Additionally , i n evaluating the Alabama climatological data for 2007, the statewide temperatures for the ye ar were above normal and the statewide precipitation for the ye ar was much below normal (see attached charts). In fact, Alabama was ranked as the 3 rd driest state for 2007 according to the rankings from the National Oce anic and Atm ospheric Administration
. See the follow ing figures for more detail. Alabama attributes the prolonged warm and dry weather that lasted throughout the ye ar as a factor in elevating emissions from soils in 2007 and resulting in monitored l ead co ncentrations for that time period that were higher than other years.12

Alabama attributes the prolonged warm and dry weather that lasted throughout the year to exacerbate l ead concentrations in th e soil. As a result, monitored l ead concentrations for that time period were higher than previous ye ars. EPA’s evaluation of the monitoring data during and just after this period of time , revealed the highest level of monitored values. Th e highest value of all of the 3
- month rolling average for the 2007
- 2009 period occurs in December of 2007 at a level of 1.35 μg/m 3 . Other monitoring values in that time period include 1.07 μg/m 3 for the November 2007 3
- month rolling average; 1.18 μg/m 3 for January 2008; 1.15 μg/m 3 for February 2008; 1.02 μg/m 3 for March 2008; and 1.05 μg/m 3 for April 2008. The 3
- month rolling averages , excluding the period of November 2007 through April 2008 , range from 0.10 μg/m 3 to 0.78 μg/m 3

. Geography/topography (mountain ranges or other air basin boundaries) The geograph y/topography anal ys is evaluates the phy sical features of the land that might have an effect on the air shed and, therefore, on the distribution of l ead over the Troy Area. The Tro y Area does not have any geograp hical 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
.13

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 tran sportation activities. The T roy Area does not have any jurisdictional boundaries that affect this anal ys is . Therefore, this factor did not play

a significant role in determining the nonattainment boundary
. Other Relevant Information EPA received additi onal information relevant to designating this area pertaining to modeling that was performed b y the State of Alabama. The American Meteorological Society /Enviro nmental Protection Agency

Regulatory

Model (AERMOD) modeling s ys tem was used in the lead design ation boundary

modeling. The AERSURFACE tool was also used to generate the surface characteristics. Onl y emission sources from Sanders Lead were modeled using Title V permit and facility data. However, other sources that may locally impact the state mon itors were not modeled. These less than 0.1 tpy sources , which are all well within the State’s recommended boundary , include K W Plastic s (a recycling facility) , and re e ntrained lead emissions from a railroad and major roadway that borde rs the Sanders Lea d facility
. Downwash was considered for all Sanders Lead stacks in the modeling. The AERMOD s ys tem was simulated twice , using both Montgomery NWS Airport site and the Sanders Lead facility surface characteristics , since site specific meteorological data at Sanders Lead was unavailable. The model was simu lated twice in this mann er because the S tate conservatively decided to utilize the surface characteristics around both sites in all modeling and reported the highest concentr ations between the two. As required b y EPA modeling guidance in 40 CFR Part 51 Appendix W: Guideline on Air Quality Models , the State included fi ve ye ars (i.e., 2001
- 2005) of meteorological data. The AMS/EPA Regulatory

Model Terrain Pre
- processor program inputs were developed with National Elevation Data. AERMOD was simulated using default modeling inputs. A 10 km by 10 km discrete Cartesian receptor grid was used in the modeling anal ys is with grid spacings of 100 meters. The maximum 3
- month rolling concentration of 0.779 μg/m 3 w as modeled near the location of the Sanders Lead stacks. As mentioned above, excluding the November 2007 through April 2008 time period, the monitored 3
- month rolling concentrations ranged from from 0.10 μg/m 3 to 0.78 μg/m 3 , which is in line with the mode led values. As noted above, Alabama attributes the highest design values to a period of time where there was unusually dry weather and many areas in the state were under drought conditions. Despite the fact that these sources were not modeled from the fa cility, the southwest yellow contours shown in the following plots from the State modeling agree with design value of 0.19 μg/m 3 from the Sanders Lead
- owned Murphee monitor. T he modeling contours and the data from the second state monitor indicate that th e l ead concentrations rapidly decrease with distance from the industrial area, railroad and14

roadway such that predicted quarterl y l ead concentrations would be below the NAAQS (i.e., >0.15 μ g/m 3 ) well within the recommended boundary of 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Facility
. The maximum predicted concentration at the outer edge of the S tate’s recommended nonattainment boundary is less than 50 percent o f the NAAQS (0.072 μg/m 3

. EPA reviewed the modeling analy sis included in Alabama’s demonstration. The results of that review are summarized below: San ders Lead, Troy , Alabama

– Pike County AERMOD Modeling 1. Source characterization a. If an y fugitives, how w ere they characterized? N o b. Did stacks use defaults or actual parameters? Used data from Sanders Lead and considered downwash c. What is the emissions year? There is no emissions year. The emissions used in the Sanders Lead Designation modeling performe d by ADEM represent the allowable emissions for the units, not the actuals. This allows for additional conservatism in the modeling. d. What is the source of the emissions (NEIor other)? Title V permit emissions

Emission rate (g/s) X (meters) Y (meters) Base elev (meters) Stack

height (meters) Stack

Temp (K) Stack

exit vel (m/s) Stack

diameter (m) STACK22 0.60000E
- 01 596668.6 3517149.0 162.0 54.86 366 36.27 1.20 STACK22 0.60000E
- 01 596701.9 3517158.2 161.2 54.86 366 36.27 1.20 STACK24A 0.30000E
- 01 596744.4 3517284.0 161.7 27.43 339 32.31 0.90 Stack24B 0.30000E
- 01 596648.4 3517188.2 161.2 27.43 339. 32.31 0.90 STACK27 0.20000E
- 01 596754.1 3517148.0 156.4 9.14 294. 18.29 1.10

e. Were actual emissions used or potential emissions
- assumed potential emissions f. Were multiple sources modeled or single source modeling done? Only emission sources from Sanders Lead were modeled. 2. Meterology a. Years and stations used
- 2001 - 2005 Montgomery (MGM) AL NWS ( 72226 )(sfc); Alabaster ( 53823 ) (upp er air) b. Was meteorological data representative of source(s), temporally and spatially (surface characteristics) - The AERMOD system was simulated twice using both Montgomery NWS Airport site and the Sanders Lead facility surface characteristics since site specific meteorological data at Sanders Lead was unavailable. 3. Receptor network15 a. Adequate spatial coverage and adequate receptor spacing? A 10 km by 10 km discrete Cartesian receptor grid was used in the modeling analysis with grid spacing of 100 meters. b. Receptors placed in ambient air locations c. Terrain included in modeling

– Yes, terrain elevations generated using National Elevation Data. 4. Output a. 3
- month rolling average contours. Highest concentration located at on the facility property. b. 1 st highest m odeled concentrations ( μ g/m 3 ) Year Facility surface

characteristics MGM NWS surface

characteristics 2001 0.835 0.365 2002 0.705 0.416 2003 0.777 0.411 2004 1.079 0.5238 2005 0.976 0.39616

Conclusion After considering the factors described above, E PA has determined that it is appropriate to include the portion of Pike C ounty as the Troy nonattainment area for the 2008 L ead NAAQS
. This area is located within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.9 7862228, which fully includes the S anders L ead Facility
. EPA is basing this nonattainment designation determination and boundary on the fact that Pike County contains two air quality monitors that show violation s of the 2008 Lead NAAQS, based on 2007
- 2009 air quality data. Additionally , the Sanders Lead facility emits relativel y large quantities of lead that EPA believes cause d the violati ons of the l ead NAAQS at those air quality monitor for this period
. Available modeling and monitoring data indicates that a boundary within a 0.8 mile (or 1.3 km) radius from a center point at latitude 31.78627106 and longitude 85.97862228, which fully includes the Sanders Lead Facility , is a sufficient distance to encompass the area that exceeds the l ead NAAQS.17

Based o n its consideration of all the relevant, 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 nearb y area that does not me et) the 2008 Lead NAAQS.