Technical Support Document (TSD) 

For the Modeling Portions of the Document Entitled "North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards", dated August 2015 

TSD Prepared October 2015 

Timothy A. Leon Guerrero 

Office of Air Monitoring and Analysis, 3AP40 

U.S. Environmental Protection Agency, Region 3 

1650 Arch Street 

Philadelphia, Pennsylvania 19103 

Reviewed by Alice Chow, Associate Director, 

Office of Air Monitoring and Analysis (3AP40) 

Date Signed 
Technical Support Document for the Modeling Portion Of the Commonwealth ofPennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

Purpose of the Technical Support Document 

This Technical Support Document (TSD) describes the Environmental Protection Agency's 

(EPA's) evaluation of the air-dispersion modeling for the North Reading N onattainment Area. 

The purpose of this TSD is to provide more detailed information than can be contained in the 

official notice published in the Federal Register. Readers who need more information than we 

provide in this TSD or want to review the modeling in more detail are encouraged to review the 

final State Implementation Plan (SIP) submitted by the Commonwealth ofPennsylvania1

• 

Introduction and Regulatory Framework 

On October 15, 2008, the U.S. Environmental Protection Agency (EPA) promulgated a revised 

health-based primary and secondary National Ambient Air Quality Standards (NAAQS) for lead. 

The 2008 primary lead NAAQS, which is set at a level to protect public health from adverse 

effects, is 0.15 micrograms per cubic meter (!lg/m3

). The secondary standard, which is set at a 

level requisite to protect the public welfare from adverse effects, is identical to the primary 

standard. 

In November of2010, the US EPA designated three (3) areas in Pennsylvania as lead 

nonattainment areas based on 2007-09 air quality monitoring data. Laureldale Borough, 

Muhlenberg Township and Alsace Township in Berks County, PA were designated as the North 

Reading Nonattainment Area. Figure 1 displays the North Reading, PA Nonattainment Area 

along with lead monitor sites and significant lead sources within the nonattainment area. 

http:Uwww.portal.state.pa.us/portal/server.pt/communitv/regulations and clean air plans/21827/state imple 

mentation plan/1830622 

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Technical Support Document for the Modeling Portion Of the Commonwealth ofPennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

North Reading, PA Lead Nonattainment Area 

Legend 

Exide 

Yuasa 

£ Lead Monitors 

Nor1hR..cllnj;~tlonatlilin101..,., NU 

0 8 Kilomelers 

Figure 1. The municipal units and lead monitoring sites that are part of the North 

Reading, PA Nonattainment Area 

Lead SIP regulations found at 40 CFR 51.11 7 require states to employ atmospheric dispersion 

modeling for the demonstration of attainment for areas in the vicinity of point sources listed in 

40 CFR 51.117(a)(1 ). Meteorological and other data are needed to complete the required airdispersion modeling. EPA notes 40 CFR 51.117( a) provides that states must include, as a part of 

their attainment modeling demonstration, an analysis showing that the SIP will attain and 

maintain the standard in areas in the vicinity of certain point sources that are emitting significant 

emissions oflead and also in "any other area that has lead air concentrations in excess of the 

national ambient air quality standard concentration." In doing the analysis, required under 40 

CFR 51.11 7 (a )(2 ), EPA expects the state will take into consideration all sources of lead 

emissions within the nonattainment area that may be required to be controlled. 

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Technical Support Document for the Modeling Portion Of the Commonwealth of Pennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

Overview of Commonwealth of Pennsylvania's General Modeling Approach 

PA DEP examined meteorological data measured by an Automated Surface Observing System 

(ASOS) at the Reading Regional Airport (KRDG) along with morning upper air data from the 

Washington Dulles International Airport (KIAD) to determine model dispersion conditions in the 

North Reading Nonattainment Area. The Reading Airport is located approximately 4 kilometers 

west ofExide Technologies (Exide) and Yuasa Battery, Inc. (Yuasa); KRDG can be seen on the 

extreme left side of Figure 1. P A DEP was aware of meteorological data collected at a tower site 

near Exide. This data, however, could not be used due to the lack of proper QA/QC 

documentation. 

To conduct the modeling attainment demonstration, PA DEP had to compile a lead emission 

inventory for significant sources near the noncompliant air monitoring sites. During 

promulgation of the 2008 lead standard, US EPA revised the requirements in 40 CFR 51.117( e) 

for lead nonattainment area SIP inventories from a 5 tons per year (tpy) threshold associated with 

the previous standard to a 0.5 tpy threshold. This was the threshold used to identify major lead 

sources in the North Reading N onattainment Area. 

PA DEP identified one (1) facility, Exide Technologies, whose lead emissions exceeded 0.5 tpy 

in the North Reading Nonattainment Area. Exide operates a secondary lead smelter that recycles 

spent lead-acid batteries and other lead-containing materials. Additional lead emissions come 

from associated material handling and processing operations at the facility. PA DEP also 

included Yuasa in its modeling analysis. Yuasa operates a lead-acid battery assembly plant 

directly east across the street from the Exide facility. 

Lead emissions from nonpoint sources and mobile sources were also examined but found to be 

insignificant and while included in PA DEP's lead inventory they were not included in the lead 

modeling demonstration. Section 211 (n) of the Clean Air Act prohibited the use of any gasoline 

containing lead or lead additives for use as fuel in motor vehicles after December 31, 1995 ( 42 

U.S.C.A. §7545) making mobile source lead emissions much smaller than the point source 

contribution. Exide and Yuasa were the only lead sources included in the final model emission 

inventory. PA DEP noted that the Exide facility is currently in an idled state with none of its 

lead smelting processes in operation. Prior to restarting these operations, Exide will have to 

implement additional lead emission controls. 

Model emission inventories for the two (2) lead sources in the North Reading were constructed 

for 201 0 and 2015. The 2015 lead emissions were used in the model attainment demonstration 

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Technical Support Document for the Modeling Portion Of the Commonwealth ofPennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

to determine if projected (future) lead emission rates would comply with the lead NAAQS. 

Table 1 summarizes lead emissions compiled by PA DEP from both Exide and Yuasa. Lead 

emissions for other (non-point) sources in the North Reading Nonattainment Area were also 

compiled but totaled less than 0.2% ofthe 2010 Base Year (actual) lead emissions from Exide 

and Yuasa (~0.0017 tpy). 

Table 1. North Reading Lead Source Emissions Summary 

Lead Source 2010 Lead Emissions 2015 Projected Lead Emissions 

Exide 1.0417 0.8991 

Yuasa 0.1520 0.0850 

Projected 2015 lead emission reductions for Exide are based on the implementation ofthe 

control measures set forth in the.National Emissions Standards for Hazardous Air Pollutants; 

Secondary Lead Smelting, 77 FR 556 (January 5, 2012, NESHAP from Secondary Lead 

Smelting), as approved in Plan Approval No. 06-050661. Additional lead emission reductions 

and stack-specific emission limits are identified in the Exide Consent Order and Agreement 

(COA) to be incorporated into the SIP. 

PA DEP entered into a COA with Yuasa to establish lower emission limits needed for the North 

Reading Nonattainment Area to reach attainment. The COA is incorporated into the SIP 

ensuring the control measures will become permanent, federally enforceable, and creditable to 

demonstrate attainment of the 2008 Lead NAAQS. 

Dispersion Modeling for the Model Attainment Demonstration 

PA DEP performed an air-dispersion modeling analysis for the North Reading Nonattainment 

Area. The air-dispersion modeling analysis was completed for base year and future year emission 

inventories representing two (2) facilities, Exide and Yuasa, with reported lead emissions in 

2010 and projected (future) emissions for 2015. The modeling was conducted in accordance with 

40 CFR Part 51, Appendix W - Guideline on Air Quality Models. 

The American Meteorological Society/Environmental Protection Agency Regulatory Model 

(AERMOD) was utilized for the model attainment demonstration. There are two (2) input data 

preprocessors that need to be run to utilize the AERMOD modeling system; AERMET, which 

preprocesses representative meteorological data and AERMAP, which preprocesses terrain data 

from the United States Geological Survey (USGS) Digital Elevation Data. In order to diagnose 

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Technical Support Document for the Modeling Portion Of the Commonwealth of Pennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

building downwash effects, the Building Profile Input Program for Plume Rise Model 

Enhancements (BPIPPRM) was executed. Since the current regulatory version of AERMOD is 

incapable of calculating the rolling three-month average concentrations necessary for 

demonstrating lead NAAQS compliance, the EPA post-processor LEAD POST was used. In its 

three-month average calculation, LEADPOST utilizes monthly average files created by 

AERMOD. 

A summary ofthe model versions used in PA DEP's model attainment demonstration is 

presented in Table 2. Generally, the most recent versions of the AERMOD and its related 

preprocessors at the time P A DEP prepared the lead SIP were used in the air-dispersion 

modeling analysis. 

Table 2. Summary of AERMOD Used in PA DEP's Modeling Analysis 

Model Version Description 

AERMOD 14134 Regulatory Air-Dispersion Model 

BPIPPRM 04274 Building Downwash Calculations for AERMOD 

AERMET 14134 AERMOD Meteorological Data Preprocessor 

AERMINUTE 14237 Processes sub-houri y met data for use in AERMET 

AERSURFACE 13016 Preprocessor for AERMETusing1992 Land Use/Land Cover 

AERMAP 11103 Terrain Processor, Preprocessor for AERMOD 

Lead Post 13262 Post Processor for AERMOD, Lead NAAQS Calculator 

Air-Dispersion Model Meteorological Data Development 

The North Reading modeling analysis utilized a five-year (2006-2010) meteorological dataset 

comprised of surface meteorological data from the Reading Airport (KRDG) and morning 

atmospheric soundings from Washington Dulles International Airport (KIAD). KRDG is located 

approximately four ( 4) kilometers west of the Exide and KIAD is located approximately 207 

kilometers southwest Exide. The data sets were reviewed for completeness and 

representativeness of the North Reading Nonattainment Area. The meteorological data sets were 

found to meet the completeness requirements outlined in Section 5.3.2 of EPA's Meteorological 

Monitoring Guidance for Regulatory Modeling Applications (EPA-454/R-99-005, February 

2000) and are representative of atmospheric conditions in the vicinity of Exide and the North 

Reading N onattainment Area. 

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Technical Support Document for the Modeling Portion Of the Commonwealth of Pennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

Meteorological files from KRDG and KIAD were processed using AERMET. AERMET is a 

meteorological preprocessor that organizes available meteorological data into a format suitable 

for use by the AERMOD air-quality dispersion model. One-minute ASOS wind data available 

from the National Climatic Data Center (NCDC) in the TD-6405 format was further processed 

using AERMINUTE to generate hourly averaged wind speed and wind direction to supplement 

the standard hourly ASOS observations. The final processed meteorological data also includes 

ASOS temperatures, surface pressure and sky cover as well as morning vertical sounding 

information from KIAD. 

In addition to the meteorological data, AERMET needs surface characteristic information 

including surface roughness, albedo and Bowen Ratio. This information was constructed using 

AERSURFACE, which extracts this information from the USGS National Land Cover Database 

(NLCD, 1992). AERSURF ACE was run at a seasonal resolution using a default 1-kilometer 

radius with twelve 30-degree sectors for surface roughness length. Surface moisture conditions 

were used in the Bowen Ratio calculation and were based on averaged precipitation data for 

Pennsylvania Climate Division 3. Specific seasonal surface moisture conditions were derived 

using precipitation data and comparing it to a 30-year climatological average to determine if a 

particular season was considered dry, average or wet in accordance with Section 2.2 of EPA's 

AERSURFACE User's Guide. Snow cover information was also examined to ensure there was 

no continuous snow cover occurring on a seasonal basis. 

Air-Dispersion Model Receptor Grid Development: 

P A DEP developed ground-level model receptors for areas defined as "ambient air" in 

accordance with 40 CFR §50.1(e). These model receptor points, once defined, are used by 

AERMOD to calculate air concentrations from lead emission sources. Facilities that have 

sufficient limitations on public access to their sites, a fence or other suitable physical barrier, do 

not have to establish model receptor points within their property boundary for their emissions. 

Shared property boundaries between Exide and Yuasa and the close proximity of the facilities 

complicated the modeling analysis. Separate model receptor grids were established over Exide 

and Yuasa in order to determine each facility's impact on the other's properties including 

flagpole receptors to determine model concentrations on buildings. A model receptor grid 

covering the remainder of the North Reading Nonattainment Area was also established. The 

model receptor grids were of sufficient density to determine maximum modeled concentrations 

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Technical Support Document for the Modeling Portion Of the Commonwealth of Pennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

and ensure modeled concentrations outside of the nonattainment area would not exceed the lead 

NAAQS. 

Once the model receptor grid was established, it was run through AERMAP to determine each 

receptor's elevation and terrain height scale, a parameter needed by AERMOD. These values 

were calculated from terrain data generally provided and maintained by the U.S. Geological 

Survey or USGS. PA DEP utilized the USGS National Elevation Dataset (NED) with a 

resolution of one-third arc-second (approximately 1 0-meter resolution). Flagpole (rooftop) 

receptors were used for receptors within the Exide and Yuasa ambient air boundaries that were 

located over buildings. 

Lead Emission Rates and Building Downwash Development 

Projected lead emissions from Exide and Yuasa were based on a combination ofNESHAP and 

COA limits. Modeled lead emissions from both facilities included stack emissions (point 

sources) and fugitive emissions (volume and area sources). A total of seventy-seven (77) lead 

emission sources were modeled for Exide while twenty-seven (27) lead emission sources were 

modeled for Yuasa. Road-dust emissions accounted for most of the model sources at Exide since 

the facility's paved surfaces were broken into sixty-six (66) individual volume sources that 

represented a small segment of each road surface. Road-dust emissions at Yuasa made up most 

of the emission sources but since the facility is much smaller its road segments consisted of only 

fifteen ( 15) sources. 

Projected building and stack configurations for Exide and Yuasa were run through EPA's BPIP 

program to determine building downwash parameters to be used in AERMOD. BPIP requires 

building locations and heights as well as stack height information to determine building 

downwash parameters. Downwash output from BPIP is then used as input into AERMOD. 

AERMOD Results Summary 

Two pieces of information are needed to determine if a nonattainment area will meet the lead 

NAAQS. These include a modeled lead concentration from an air-dispersion model like 

AERMOD and a representative background lead concentration. A dispersion model like 

AERMOD will estimate the ambient lead concentrations based on hourly lead emissions that are 

included as model inputs. The purpose of a representative background lead concentration is to 

account for minor ancillary sources that may not be explicitly modeled. 

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Technical Support Document for the Modeling Portion Of the Commonwealth ofPennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

PA DEP reviewed monitoring data from the two closest lead monitors to the Exide and Yuasa 

facilities. Lead emissions from both Exide and Yuasa have inevitably contributed to Laureldale 

North's and Laureldale South's monitored lead concentrations. Given that monitoring 

concentrations represent a composite 24-hr sample, it is difficult to isolate the _impacts of Exide 

and Yuasa on the monitor concentrations thus giving rise to the possibility of"double counting" 

their contributions when combining the modeled and monitored results. P A DEP decided to use 

a background lead concentration from a regional lead monitor to alleviate this possibility. The 

Ridley Park lead monitor was chosen as the background monitor after reviewing lead 

concentrations from three (3) surrounding lead monitors. The Ridley Park lead monitor is 

located in Delaware County, PA approximately 76 kilometers southeast ofExide. Background 

lead concentrations based on the 2012-14 design value at Ridley Park were 0.012 )lg/m3. 

AERMOD does not directly calculate 3-month lead concentrations. LEADPOST must be run 

using specific output files generated by AERMOD to calculate a modeled 3-month lead 

concentration in the form of the NAAQS. LEADPOST takes AERMOD output files and 

calculates a rolling 3-month average lead concentration. This modeled concentration is then 

added to the background concentration and compared with the lead NAAQS to determine 

compliance. 

The highest projected 3-month modeled lead concentration from LEADPOST was 0.129107 

)lglm3. Projected (future) modeled 3-month maximum lead concentrations over the North 

Reading Nonattainment Area are shown in Figure 2. Peak modeled concentrations occur just 

south of Yuasa. Figure 3 shows modeled concentrations surrounding Exide and Yuasa. Model 

receptors were placed within both facility's ambient-air boundary since the emissions from each 

facility cannot be excluded on the other facility's property. Thus model concentrations on 

Exide's property represent impacts from Yuasa emissions and model concentrations on Yuasa's 

property represent impacts from Exide's emissions. Model concentrations on Exide's property 

are lower since these model receptors are only impacted by emissions from Yuasa, which are 

much lower than emissions from Exide. 

The final modeled lead concentration is the maximum projected 3-month lead concentration 

from LEADPOST plus the background monitored concentration from the Ridley Park monitor. 

This yields a projected lead concentration of0.129107 )lg/m3 plus 0.012 )lg/m3, or 0.141107 

)lg/m3

, which is below the 2008 lead NAAQS of 0.15 )lg/m3. This indicates that projected lead 

concentrations based on projected operations at Exide and Yuasa (plus a representative 

background concentration) will meet the 2008 Lead NAAQS. 

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Technical Support Document for the Modeling Portion Of the Commonwealth of Pennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

North Reading, PA Lead Nonattainment Area 

Legend 

< O.OtO uglm1 

0.011 - 0.02 5 ugtml 

0.015 . 0015 uglmJ 

0.075 · 0.100 IJ9Iml 

,0.100 ugl~ 

Max Rec eptor (0. 129107 ug.!nll 

Figure 2. Projected (future) maximum 3-month lead concentrations from PA DEP's 

AERMOD analysis. 

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Technical Support Document for the Modeling Portion Of the Commonwealth of Pennsylvania's 

. Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

North Reading, PA Lead Nonattainment Area 

Legend 

< 0010 u9}ml 

0010 - 0 025 l)Qiml 

0025-0.015 U9"n1l 

0.075-0.110 ugtml 

-" 0.100 uglm3 

MaxRec.eptor(0.129107 u!)hn) 

0 015 0.3 

Figure 3. Close up of projected (future) maximum 3-month lead concentrations from PA 

DEP's AERMOD analysis. 

Summa•y of EPA's Technical Findings 

EPA has reviewed PA DEP's modeling analysis for the North Reading Nonattainment Area. PA 

DEP conducted air-dispersion modeling using EPA's AERMOD modeling system. In general, 

PA DEP followed procedures outlined in 40 CFR Part 51, Appendix W- Guideline on Air 

Quality Models. Meteorological data met data completeness requirements, was representative of 

atmospheric conditions in the North Reading Nonattainment Area and was properly processed 

using AERMOD's preprocessors AERMET and AERSURFACE. The model receptor grid was 

designed to capture the maximum projected (future) modeled concentrations and properly 

processed using appropriate terrain information via AERMAP. Projected (future) lead emission 

inventories were developed for use in AERMOD along with source building and stack 

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Technical Support Document for the Modeling Portion Of the Commonwealth of Pennsylvania's 

Lead State Implementation Plan (SIP) entitled North Reading Nonattainment Area, 

Berks County for the 2008 Lead National Ambient Air Quality Standards August 2015 

configurations to calculate building downwash conditions. An appropriate regionally 

representative background lead concentration was determined using monitoring data from the 

Ridley Park lead monitor. A regional lead monitor was chosen instead of using local monitors to 

remove any impacts ofExide's or Yuasa's lead emissions on the monitoring data. This removes 

the possibility of "double counting" source impacts in the modeling analysis and the background 

monitoring data. 

PA DEP's projected maximum 3-month modeled lead concentration was added to Ridley Park's 

3-month background 2012-14 design value concentration. The final projected modeled lead 

concentration was 0.129107 j.Lg/m3. This concentrations was added to the background lead 

concentration of0.0121J.g/m3 and yielded a total projected (future) 3-month lead concentration of 

0.141107 j.Lg/m3. This projected (future) lead concentration is below the 2008 Lead NAAQS 

(0.15 j.Lg/m3

) and demonstrates that North Reading Nonattainment Area will reach attainment 

with the lead standards established by the US EPA. 

Recommendation of Approval ofPA DEP's Model Attainment Demonstration 

EPA has evaluated the information provided in PA DEP's lead SIP for the North Reading 

Nonattainment Area and concludes that the Commonwealth's model attainment demonstration 

shows current lead control and emission limits will provide for attainment of the 2008 Lead 

NAAQS. 

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