LEAD AIR QUALITY MODEL

ARECIBO AREA
TABLE OF CONTENTS

1.0 Introduction........................................................................ 1

1.1 Model.............................................................................. 2

1.2 Meteorology...................................................................... 2

1.3 Receptors............................................................................ 3

1.4 Results.............................................................................. 4

1.5 Conclusion......................................................................... 10

APPENDIX A

A-1 INITIAL LATERAL (σzο) AND VERTICAL DIMENSIONS (σyο)

A-2 ALL SOURCES DAILY/MONTHLY RESULTS OVER 0.15 UG/M3

A-3 VOLUME/AREA SOURCES MODEL MONTHLY RESULTS OVER 0.15 

UG/M3

A-4 VOLUME/AREA SOURCES MODEL DAILY RESULTS OVER 0.15 

UG/M3

A-5 HIGH DAILY LEAD CONCENTRATIONS IMPACT AREA

A-6 LEADPOST OUTPUT FILE
LIST OF FIGURES 

 

Figure 1: Facility Stack, Volume and Area Sources................................... 3

Figure 2: Receptor Grids................................................................... 3

Figure 3: Lead Daily Modeling Concentrations, 

 Stack/Volume & Area Sources................................................ 6

Figure 4: Lead Monthly Modeling Concentrations, 

 Stack/Volume & Area Sources................................................ 6

Figure 5: Lead Daily Modeling Concentrations, 

 Volume Source..................................................................... 7

Figure 6: Lead Monthly Modeling Concentrations, 

 Volume Source.................................................................. 7

Figure 7: Lead Daily Modeling Concentrations, 

 Area Source...................................................................... 8

Figure 8: Lead Monthly Modeling Concentrations, 

 Area Source...................................................................... 8

Figure 9: Lead Daily Modeling Concentrations, Stack................................ 9

Figure 10: Lead Monthly Modeling Concentrations, Stack............................ 9
LIST OF TABLES

Table 1: Arecibo Lead Air Quality Model Results.................................... 5
1.0 Introduction

In January 2010 a new source oriented lead air quality monitor was establish at 

Arecibo as part of the new air quality standard for lead of 0.15μg/m3. On June 

2010, the new NAAQS was exceeded according with the data capture by this new 

lead monitor and in June 2011 EPA design the Arecibo area as non-attainment for 

the lead rolling 3-month average NAAQS.

As required by the new NAAQS and SIP regulation, the emissions inventory for

lead was revised and a lead air quality model was performed in the Arecibo area. 

The following document presents the results of this air modeling study.

The facilities that more emit lead in Arecibo area are Battery Recycling and 

PREPA Cambalache. A modeling study was executed with the emissions of these 

two sources trying to identify the origin of the lead standard violation. The model 

used was AERMOD and this is the current preferred EPA model for air quality 

modeling studies.

The preliminary modeling results indicate that the primary source causing the high 

lead concentration is Battery Recycling, the concentrations from PREPA 

Cambalache were below the standard or negligible. The refined modeling using 

only the lead emissions from Battery Recycling showed that the source has the 

major contribution to the high monitoring concentration. 

The lead emissions used in the modeling were submitted by Battery Recycling 

during the permit process and were reviewed by the permit personnel. A site-visit 

was done with the GPS personnel to take and revise the coordinates and 

dimensions of the facility buildings and the emission points. One year of on-site 

meteorological data was used in the study and it was captured during 1992-1993, 

in the PREPA Cambalache Station.

Three types of lead emission points were modeled in the Battery Recycling facility. 

The emission points were the stack, the fugitive emissions from the main process 

building and the fugitive emissions due to the material handling and transport

across the facility property. 
2

1.1 Model

The model used in the study was AERMOD. Battery Recycling emission points 

were divided in two categories, stack and fugitive emissions. The lead potential 

emissions emitted through the stack are 0.59 tons/yr. The stack emissions are 

those captured by the control equipment inside the main process building. The 

main process lead fugitive emissions are those that the control equipment do not 

capture during the smelting process and escape to the environment through the 

open areas of the building. The other lead fugitive emissions are outside the main 

process building from the vehicular movement during the transport and handling of 

materials. The fugitive emissions inside the main process building are 0.353

tons/yr and the fugitive emissions due to handling and transport of material are 

0.27 tons/yr.

Two types of emission sources were used to model the fugitive emissions, volume 

and area. The volume source option was used to model the fugitive emissions 

inside the main process building that the control equipment does not capture. The 

building was modeled as a volume source because is not open completely like an 

area source. The initial lateral and vertical dimensions of the building and the 

center coordinates were determined through GPS, see Appendix A-1. 

The area source was used to model the emissions generated from the vehicle 

movement between the carbon, scrap and soda ash storages. A fourteen-vertex

polygon was created covering the area that the facility vehicles transit daily

between these storages, approximately 4742 m2. This is a conservative scenario 

but it was the best modeling approximation of these fugitive emissions that could

be use at this moment, with the available data. 

The facility is under construction and some changes have been made to the main 

process building and the storage areas that are not seen in the current aerial photos. 

Figure 1 shows the facility with the property fenceline, stack, volume and area 

sources. 

1.2 Meteorology

One year of on-site meteorological data from 1992-1993 collected in the PREPA 

Cambalache station was used in the model. The data was processed using the 

AERMET new version that incorporates two surface characteristics in cases of onsite missing data. Meteorological data from San Juan station was used for the 

substitution of the on-site missing data.
3

1.3 Receptors

The terrain area that surrounds Battery Recycling is flat rural area with some 

elevated terrain at 4 km approximately to the southwest/southeast. Two receptor 

grids were used for the study, one of 250 meters and a refined grid of 100 meters. 

AERMOD model uses AERMAP to process the terrain data and the receptor 

elevations are subtracted from the DEM maps. The UTM coordinates for the grids 

were southwest corner 739500 East/2038000 North and northeast corner 746500 

East/2045750 North for the 250 meters and southwest corner 742750 East/2042000 

North and northeast corner 742950 East/2043000 North for the 100 meters. Figure 

2 shows the receptor grids.

Figure 1: Facility Stack, Volume and Area Sources

Figure 2: Receptor Grids
4

1.4 Results

The modeling results showed violations of the rolling 3-month average lead 

standard caused by the emissions of the area and the volume sources. The volume 

source emissions have the major contribution to the rolling 3-month average. The 

emissions of the volume and area sources caused high daily and monthly lead 

concentration results, see Appendixes A-3 and 4. The stack lead emissions do not 

caused any violation of the standard, see Figures 9 and 10. The highest first 

highest value was used to have a conservative scenario. 

Two periods were evaluated, daily and monthly. The model daily value was used

because the EQB lead monitoring station registers the concentrations daily and it is 

a way to determine how close the model predictions are to the monitored value. 

Leadpost processor was used for the calculation of the rolling 3-month average

using the monthly modeling results. 

Background concentration was omitted because EQB does not have another nearby 

lead air quality monitor that could be representative of the area and background 

emissions are presumed negligible because besides PREPA Cambalache, there are 

no other lead emissions sources nearby Battery Recycling. The model results are 

presented in Table 1.

The results show that the highest lead concentration comes from the emissions of 

the volume source in both periods. These values were registered inside the facility 

property, at the same receptor as the rolling 3-month average. The area source has 

high daily and monthly lead concentrations but the contribution to the rolling 3-

month average was minor. 

Other high lead concentrations were registered nearby the facility. Figures 3 and 4 

show the modeling concentration isopleths with the contribution of all the facility 

lead emissions, for the daily and monthly results, respectively. Appendix A-3

shows the rolling 3-month average of 3.32 ug/m3at 743500 East/2042000 North. 

The rolling 3-month average of the volume source at this location was 3.088 ug/m3

and the area source rolling 3-month average was 0.232 ug/m3. A copy of the 

leadpost output file is in Appendix A-6.
5

Table 1: Arecibo Lead Air Quality Model Results

Emission 

Point

Model 

Group Id

Daily Model 

Result ug/m3

Monthly 

Model Result 

ug/m3

Rolling 3-

Month Average 

ug/m3

Coordinates

East North

Stack BR 0.090 - - 743150 2042100

Volume 

Source

Fugitive 8.89 - - 743500 2042000

Area 

Source 

Handling 8.19 - - 743450 2042100

All All 9.31 - - 743450 2042100

Emission 

Point

Model 

Group Id

Daily Model 

Result ug/m3

Monthly 

Model Result 

ug/m3

Rolling 3-

Month Average 

ug/m3

Coordinates

East North

Stack BR - 0.031 - 743250 2042000

Volume 

Source

Fugitive - 3.70 - 743500 2042000

Area 

Source 

Handling - 2.33 - 743450 2042100

All All - 3.87 - 743500 2042000

Emission 

Point

Model 

Group Id

Daily Model 

Result ug/m3

Monthly 

Model Result 

ug/m3

Rolling 3-

Month Average 

ug/m3

Coordinates

East North

Stack BR - - 0.000 743500 2042000

Volume 

Source

Fugitive - - 3.088 743500 2042000

Area 

Source 

Handling - - 0.232 743500 2042000

All All - - 3.32 743500 2042000
6

Figure 3: Lead Daily Modeling Concentrations, Stack/Volume & Area Sources

Figure 4: Lead Monthly Modeling Concentrations, Stack/Volume & Area Sources
7

Figure 5: Lead Daily Modeling Concentrations, Volume Source

Figure 6: Lead Monthly Modeling Concentrations, Volume Source
8

Figure 7: Lead Daily Modeling Concentrations, Area Source

Figure 8: Lead Monthly Modeling Concentrations, Area Source
9

Figure 9: Lead Daily Modeling Concentrations, Stack

Figure 10: Lead Monthly Modeling Concentrations, Stack
10

1.5 Conclusion

The model results showed high daily lead concentrations up to 4 km from the 

source, see Appendix A-2. The Appendix A-5 shows a 4 km radio that includes 

the areas of the wards in Arecibo municipality that could be impacted with these

daily high lead concentrations. The monthly violations extend up to 2 km from the 

source, see Appendix A-2. 

According to the modeling study, the Battery Recycling fugitive emissions were 

the major contributors to the high lead concentrations in the area. The major 

contribution to the rolling 3-month average is from the emissions of the main 

process building but the emissions from the handling and transport of material by 

itself, cause a violation of the lead rolling 3-month average.

 
APPENDIX A
A-1

INITIAL LATERAL (σzο) AND VERTICAL DIMENSIONS (σyο)

σzο= 68.57 meters/4.3 = 15.94 m

σyο= 14.5 meters/2.15 = 6.74 m 
A-2

ALL SOURCES DAILY/MONTHLY RESULTS OVER 0.15 UG/M3
A-3

VOLUME/AREA SOURCES MODEL MONTHLY RESULTS OVER 0.15 

UG/M3
A-4

VOLUME/AREA SOURCES MODEL DAILY RESULTS OVER 0.15 UG/M3
A-5

HIGH DAILY LEAD CONCENTRATIONS IMPACT AREA
A-6

LEADPOST OUTPUT FILE