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Technical Support Document

Pennsylvania

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 portion of Beaver County in Pennsylvania that EPA intends to 

designate “nonattainment” for the 2008 lead national ambient air quality standard (2008 Lead

NAAQS).

Table 1. Proposed Nonattainment Area for 2011 Designations

Area

Pennsylvania 

Recommended 

Nonattainment 

Counties

Pennsylvania’s 

Recommended 

Nonattainment 

Townships/

Boroughs

EPA’s 

Proposed

Nonattainment 

Counties

EPA’s 

Proposed 

Nonattainment 

Townships/

Boroughs 

Lower Beaver 

Valley

Beaver County

(partial) 

Potter and 

Vanport

Beaver County

(partial)

Potter, Vanport 

and Center

Figure 1. Map of Beaver County containing the Lower Beaver Valley Area in relation to 

the rest of the Commonwealth of Pennsylvania.
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Technical Analysis for The Lower Beaver Valley Area

Introduction 

This technical analysis for The Lower Beaver Valley Area 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.

Figure 2 is a map of the area analyzed showing the locations of air quality monitors in the area

and the proposed nonattainment area. 

Figure 2. Lower Beaver Valley Proposed Nonattainment Area and Air Quality Monitor 

Locations
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On December 17, 2009, Pennsylvania recommended that part of Beaver County be designated as 

nonattainment for the 2008 Lead NAAQS based on air quality data from 2006 - 2008. Their 

recommendation was based on data from FRM or FEM monitors located in the state. In 2010, 

EPA designated part of Beaver County nonattainment, consistent with Pennsylvania’s 

recommendation (75 FR 71033, November 22, 2010).

Pursuant to the revised network design requirements adopted in the Lead NAAQS final rule (73 

FR 66964, November 12, 2008), Pennsylvania established new lead monitors, including one in 

Center Township. Based on EPA's technical analysis described below (including data from the 

new monitors), EPA is intending to revise the 2010 Nonattainment Designation for parts of 

Beaver County in Pennsylvania. This county and the townships/boroughs included in the revised 

proposed nonattainment area 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 Beaver County

in the Lower Beaver Valley Area 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 two 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 three full calendar years 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 Beaver County in the Lower Beaver Valley Area and 

surrounding area are shown in Table 2 and illustrated in Figure 2.
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Table 2. Air Quality Data

County State 

Recommended

Nonattainment?

Monitor Name Monitor Air 

Quality 

System ID

Monitor 

Location

Lead Design 

Value, 

2007 - 2009

(μg/m3)

Lead Design 

Value, 

2008-2010

(μg/m3)

Beaver 

County

Yes (partial) Monaca 

(Horsehead 

Corp.)

42-007-

0007

Beaver Valley 

Mall, Monaca, 

PA 15071

N/A 0.21

Vanport 

(Horsehead 

Corp.)

42-007-

0505

265 River Ave., 

Beaver, PA 

15009

0.17 0.17

Potter (Bruce 

Mansfield)

42-007-

0006

206 Mowry 

Rd., Monaca, 

PA 15071

N/A Incomplete

Monitors in Bold have the highest 2008-2010 design value in the respective county.

Beaver County shows a violation of the 2008 Lead NAAQS. Therefore, some area in this county 

must be designated nonattainment. The absence of a violating monitor alone is not a sufficient 

reason to eliminate nearby counties as candidates for nonattainment status. Each area has been 

evaluated based on the weight of evidence of the eight factors collectively combined into five 

like groupings and other relevant information

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 and airport sources (there are approximately 20,000 airport 

facilities in the U.S. at which leaded aviation gasoline is consumed) were derived from the 2008

National Emissions Inventory, version1.5 (NEI08V1.5), which was the most current version of 

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

process. See http://www.epa.gov/ttn/chief/net/2008inventory.html#inventorydoc. EPA 

recognizes that we have no information on any emissions increases 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. 

Pennsylvania provided updated emissions information, provided in Table 3. The data provided 

by Pennsylvania was the most current emission information available at the time of their 

submittal. For 2008 emissions from Pennsylvania and the 2008 NEI are the same for the lead 

sources in Table 3. 

Table 3 shows total emissions of lead (given in tons per year) for violating and potentially 

contributing townships/boroughs in and around the Lower Beaver Valley Area and sources 

emitting (or anticipate to contribute) greater than 0.1 ton per year of lead according to the state 
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emission inventory (eF.A.C.T.S.) for the years 2007, 2008, and 2009. See 

http://www.dep.state.pa.us/dep/efacts/. Facilities that are part of the Lower Beaver Valley 

Nonattainment Area for the 2008 Lead NAAQS are shown in boldface. The EPA has chosen to 

accept Pennsylvania’s use of the inventory. Figure 3 and 4 below shows the distance between the 

First Energy Generation Corp/Bruce Mansfield Plant and the Lower Beaver Valley 

Nonattainment Area. During this second round of designations in 2011, Beaver has been 

reevaluated based on new monitoring data to expand the area as discussed in the 2010 

Designation TSD for the 2008 Lead NAAQS. 

Table 3. Facility lead emissions greater than 0.1 tons per year

County Facility in State 

Recommended 

Nonattainment

Area

Facility Name and 

Location

Facility – Total 

Air Emissions 

2007-eFacts 

Pennsylvania’s 

State inventory 

(tons per year)

Facility – Total 

Air Emissions 

2008-eFacts 

Pennsylvania’s 

State inventory 

(tons per year)

Facility – Total 

Air Emissions 

2009-eFacts 

Pennsylvania’s 

State inventory 

(tons per year)

Beaver

County, PA Yes 

Horsehead 

Corp./Monaca 

Smelter

5.64 5.38 3.825.

300 Frankfort Rd.

Beaver 

County, PA

No First Energy Gen. 

Corp/ Bruce 

Mansfield Plant

State Route 168 

South

1.20 0.70 0.70

Beaver 

County, PA

No Jewel Acquisition/ 

Midland Factory

12th St. & Midland 

Ave.

0.30 0.10 0.10
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Figure 3. Lower Beaver Valley Nonattainment Area with facility locations within Beaver 

County, Pennsylvania.
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Figure 4. Lower Beaver Valley Nonattainment Area and Surrounding Sources

Population Data, Growth Rates, and Patterns 

Table 4 shows the 2008 population for Beaver County being 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 activity contributing to elevated ambient lead levels. 

This may include ambient lead contributions from activities that would disturb lead that has been 
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deposited on the ground or on other surfaces. Re-entrainment of historically deposited lead is 

not reflected in the emissions inventory.

Table 4. Population Data

County State 

Recommended 

Nonattainment?

2008 

Population

2008

Population 

Density 

(pop/sq mi)

Population 

Change 

2000-2008

Population 

% Change 

2000-2008

Beaver 

County, 

PA

Yes (partial)

172,476 389 -8,639 -5%

Source of data: U.S. Census Bureau estimates for 2008 (http://www.census.gov/popest/datasets.html) and estimation 

of the area of U.S. Counties

Beaver County has a declining population trend between 2000 and 2008. EPA has considered 

the growth rate of population density and related commercial development for this area and does 

not believe that it affects EPA’s proposed final decision.

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 Tables 3 represent 

emissions levels taking into account any control strategies implemented in the Lower Beaver 

Valley Nonattainment Area before 2007 on stationary sources. 

Horsehead Corporation is a zinc processing facility which produces high purity zinc oxide and

high grade zinc metal using a two step distillation process. There are two sources responsible for 

the majority of the lead emissions from the facility: the sintering line and the electrothermic 

furnace line. Raw materials consisting of crude zinc oxide and other secondary materials are fed 

to a sintering machine. Under high temperatures, air is drawn through the materials, resulting in 

fused chunks that become feedstock for the electrothermic furnaces. Various impurities (such as 

lead) are volatilized during the processing. Emissions from this process are controlled by a 

baghouse. According to the company, 95 % of the lead emissions from the furnaces are emitted 

through baghouses, and only 5% escapes as fugitive emissions.

Meteorology (weather/transport patterns)

For this factor, EPA considered data from National Weather Service instruments and other 

meteorological monitoring sites in the area. Wind direction and wind speed data is 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. This data is summarized in Figure 5 and Table 

5, below. This 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. Wind directions summarized by season for Beaver County, PA

Table 5. Top two prevailing wind directions by season for Beaver County, PA

Season Wind direction 

Percent of 

wind at that 

direction

Winter West, Southwest 25

Winter West, Northwest 22

Spring West, Northwest 20

Spring West, Southwest 16

Summer West, Southwest 20

Summer South, Southwest 18

Autumn West, Southwest 19

Autumn West, Northwest 18

As shown in the graph in Figure 4 and Table 5, the prevailing surface winds were predominantly 

from the west, northwest and west, southwest for all four seasons.

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 the Lower Beaver Valley 

Nonattainment Area. 
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The Lower Beaver Valley Nonattainment 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.

The proposed Lower Beaver Valley Nonattainment Area is constructed using the township 

boundaries within Beaver County. 

Conclusion

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

appropriate to include the portion of Beaver County, PA listed in Table 1 in the Lower Beaver 

Valley Nonattainment Area for the 2008 Lead NAAQS. 

The air quality monitors in Beaver County show a violation of the 2008 Lead NAAQS, based on 

2008 - 2010 air quality data and support the expansion of the previously designated Lower 

Beaver Valley Nonattainment Area to include Center Township. EPA is modifying 

Pennsylvania’s recommendation by adding Center Township to the Lower Beaver Valley 

Nonattainment Area. EPA’s nonattainment area includes Center Township, Potter Township,

and Vanport Township located within Beaver County. Center Township has been added to 

Pennsylvania’s recommended Lower Beaver Valley Area because of the violating new monitor 

located within this township. 

Based on 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 nearby area that does not meet) the 2008 Lead 

NAAQS.
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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 three years of quality assured air quality 

monitoring data from 2008-2010 including at least one valid three-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 three years of quality assured air quality 

monitoring data from 2008-2010 including 36 consecutive valid three-month site means 

(including the last two 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 three 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.