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2007 National Monitoring Programs (UATMP
and NATTS) Volume I: Main Content
December 2008
Final Report
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EPA-454/R-08-008a
December 2008
2007 National Monitoring Programs (UATMP and NATTS) Volume I: Main Content
By:
Eastern Research Group, Inc.
Research Triangle Park, North Carolina
Prepared for:
Margaret Dougherty and Mike Jones
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
Contract No. 68-D-03-049
Delivery Orders 14 & 15
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emissions, Monitoring and Analysis Division
Research Triangle Park, NC 27711
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2007 National Monitoring Programs
(UATMP and NATTS)
Final Report
EPA Contract No. 68-D-03-049
Delivery Order 14
Delivery Order 15
Prepared for:
Margaret Dougherty and Mike Jones
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Prepared by:
Eastern Research Group, Inc.
1600 Perimeter Park
Morrisville, NC 27560
December 2008
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DISCLAIMER
Through its Office of Air Quality Planning and Standards, the U.S. Environmental Protection
Agency funded and managed the research described in this report under EPA Contract
No. 68-D-03-049 to Eastern Research Group, Inc. This report has been subjected to the
Agency=s peer and administrative review and has been approved for publication as an EPA
document. Mention of trade names or commercial products in this report does not constitute
endorsement or recommendation for their use.
11
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TABLE OF CONTENTS
age
List of Figures xxii
List of Tables xxx
List of Acronyms xlv
Abstract xlvii
1.0 Introduction 1-1
1.1 Background 1-1
1.2 The Report 1-2
2.0 The 2007 NATTS/UATMP Network 2-1
2.1 Monitoring Locations 2-1
2.2 Analytical Methods Used and Pollutants Targeted for Monitoring 2-8
2.2.1 VOC and SNMOC Concurrent Sampling and Analytical Methods 2-14
2.2.2 Carbonyl Sampling and Analytical Method 2-17
2.2.3 Semivolatile Sampling and Analytical Method 2-18
2.2.4 Metals Sampling and Analytical Method 2-19
2.2.5 Hexavalent Chromium Sampling and Analytical Method 2-20
2.3 Sample Collection Schedules 2-20
2.4 Completeness 2-26
3.0 Summary of the 2007 NATTS/UATMP Data Treatment and Methods 3-1
3.1 Data Treatment 3-1
3.2 Approach to Risk Screening and Pollutants of Interest 3-2
3.3 Risk Screening Evaluation Using Minimum Risk Levels 3-4
3.4 Pearson Correlations 3-5
3.5 Additional Program-Level Analyses of the 2007 NATTS/UATMP Dataset 3-6
3.5.1 The Impact of Mobile Source Emissions on Spatial Variations 3-6
3.5.2 Variability Analyses 3-7
3.5.3 Greenhouse Gas Assessment 3-8
3.6 Additional Site-Specific Analyses 3-9
3.6.1 Emission Tracer Analysis 3-9
iii
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TABLE OF CONTENTS (Continued)
3.6.2 Back Trajectory Analysis 3-9
3.6.3 Wind Rose Analysis 3-10
3.6.4 Site Trends Analysis 3-10
3.6.5 Cancer andNoncancer Surrogate Risk Approximations 3-12
3.6.6 Risk-Based Emissions Assessment 3-14
4.0 Summary of the 2007 NATTS/UATMP Data 4-1
4.1 Statistical Results 4-1
4.1.1 Target Pollutant Detections 4-1
4.1.2 Concentration Range 4-12
4.1.3 Summary Statistics 4-13
4.2 Risk Screening and Pollutants of Interest 4-15
4.2.1 Concentrations of the Pollutants of Interest 4-19
4.2.2 Risk Screening Assessment Using MRLs 4-23
4.2.3 Correlation Between Concentrations and Meteorological Conditions.. 4-25
4.2.3.1 Maximum and Average Temperature 4-25
4.2.3.2 Moisture 4-25
4.2.3.3 Wind and Pressure 4-27
4.3 The Impact of Mobile Sources 4-28
4.3.1 Mobile Source Emissions 4-28
4.3.2 Hydrocarbon Concentrations 4-31
4.3.3 Motor Vehicle Ownership 4-31
4.3.4 Estimated Traffic Volume 4-33
4.3.5 Vehicle Miles Traveled 4-34
4.3.6 Mobile Source Tracer Analysis 4-35
4.3.7 BTEX Concentration Profiles 4-36
4.4 Variability Analysis 4-41
4.4.1 Coefficient of Variation 4-41
4.4.2 Seasonal Variability Analysis 4-53
4.5 Greenhouse Gases 4-76
5.0 Sites in Arizona 5-1
5.1 Site Characterization 5-1
5.2 Meteorological Characterization 5-7
5.2.1 Climate Summary 5-7
5.2.2 Meteorological Conditions in 2007 5-7
IV
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TABLE OF CONTENTS (Continued)
5.2.3 Composite Back Trajectories for Sampling Days 5-9
5.2.4 Wind Roses for Sampling Days 5-9
5.3 Pollutants of Interest 5-13
5.4 Concentrations 5-15
5.4.1 2007 Concentration Averages 5-15
5.4.2 Concentration Trends 5-17
5.5 Pearson Correlations 5-17
5.6 Additional Risk Screening Evaluations 5-19
5.6.1 Risk Screening Assessment Using MRLs 5-19
5.6.2 Cancer andNoncancer Surrogate Risk Approximations 5-21
5.6.3 Risk-Based Emissions Assessment 5-24
5.7 Summary of the 2007 Monitoring Data 5-28
6.0 Sites in California 6-1
6.1 Site Characterization 6-1
6.2 Meteorological Characterization 6-8
6.2.1 Climate Summary 6-8
6.2.2 Meteorological Conditions in 2007 6-8
6.2.3 Composite Back Trajectories for Sampling Days 6-9
6.2.4 Wind Roses for Sampling Days 6-13
6.3 Pollutants of Interest 6-14
6.4 Concentrations 6-15
6.4.1 2007 Concentration Averages 6-15
6.4.2 Concentration Trends 6-16
6.5 Pearson Correlations 6-17
6.6 Additional Risk Screening Evaluations 6-17
6.6.1 Risk Screening Assessment Using MRLs 6-17
6.6.2 Cancer andNoncancer Surrogate Risk Approximations 6-19
6.6.3 Risk-Based Emissions Assessment 6-21
6.7 Summary of the 2007 Monitoring Data 6-24
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TABLE OF CONTENTS (Continued)
7.0 Site in Colorado 7-1
7.1 Site Characterization 7-1
7.2 Meteorological Characterization 7-5
7.2.1 Climate Summary 7-6
7.2.2 Meteorological Conditions in 2007 7-6
7.2.3 Composite Back Trajectories for Sampling Days 7-6
7.2.4 Wind Rose for Sampling Days 7-9
7.3 Pollutants of Interest 7-10
7.4 Concentrations 7-11
7.4.1 2007 Concentration Averages 7-11
7.4.2 Concentration Trends 7-12
7.5 Pearson Correlations 7-13
7.6 Additional Risk Screening Evaluations 7-13
7.6.1 Risk Screening Assessment Using MRLs 7-13
7.6.2 Cancer andNoncancer Surrogate Risk Approximations 7-15
7.6.3 Risk-Based Emissions Assessment 7-18
7.7 Summary of the 2007 Monitoring Data 7-21
8.0 Site in Washington, D.C 8-1
8.1 Site Characterization 8-1
8.2 Meteorological Characterization 8-5
8.2.1 Climate Summary 8-5
8.2.2 Meteorological Conditions in 2007 8-6
8.2.3 Composite Back Trajectories for Sampling Days 8-6
8.2.4 Wind Rose for Sampling Days 8-9
8.3 Pollutants of Interest 8-10
8.4 Concentrations 8-10
8.4.1 2007 Concentration Averages 8-11
8.4.2 Concentration Trends 8-12
8.5 Pearson Correlations 8-12
8.6 Additional Risk Screening Evaluations 8-12
vi
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TABLE OF CONTENTS (Continued)
8.6.1 Risk Screening Assessment Using MRLs 8-12
8.6.2 Cancer and Noncancer Surrogate Risk Approximations 8-14
8.6.3 Risk-Based Emissions Assessment 8-14
8.7 Summary of the 2007 Monitoring Data 8-18
9.0 Sites in Florida 9-1
9.1 Site Characterization 9-1
9.2 Meteorological Characterization 9-16
9.2.1 Climate Summary 9-16
9.2.2 Meteorological Conditions in 2007 9-16
9.2.3 Composite Back Trajectories for Sampling Days 9-17
9.2.4 Wind Roses for Sampling Days 9-25
9.3 Pollutants of Interest 9-30
9.4 Concentrations 9-31
9.4.1 2007 Concentration Averages 9-31
9.4.2 Concentration Trends 9-34
9.5 Pearson Correlations 9-38
9.6 Additional Risk Screening Evaluations 9-40
9.6.1 Risk Screening Assessment Using MRLs 9-40
9.6.2 Cancer and Noncancer Surrogate Risk Approximations 9-40
9.6.3 Risk-Based Emissions Assessment 9-43
9.7 Summary of the 2007 Monitoring Data 9-50
10.0 Site in Georgia 10-1
10.1 Site Characterization 10-1
10.2 Meteorological Characterization 10-5
10.2.1 Climate Summary 10-6
10.2.2 Meteorological Conditions in 2007 10-6
10.2.3 Composite Back Trajectories for Sampling Days 10-6
10.2.4 Wind Rose for Sampling Days 10-9
10.3 Pollutants of Interest 10-10
10.4 Concentrations 10-11
vii
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TABLE OF CONTENTS (Continued)
10.4.1 2007 Concentration Averages 10-11
10.4.2 Concentration Trends 10-12
10.5 Pearson Correlations 10-12
10.6 Additional Risk Screening Evaluations 10-12
10.6.1 Risk Screening Assessment Using MRLs 10-12
10.6.2 Cancer and Noncancer Surrogate Risk Approximations 10-14
10.6.3 Risk-Based Emissions Assessment 10-14
10.7 Summary of the 2007 Monitoring Data 10-19
11.0 Sites in Illinois 11-1
11.1 Site Characterization 11-1
11.2 Meteorological Characterization 11-7
11.2.1 Climate Summary 11-7
11.2.2 Meteorological Conditions in 2007 11-7
11.2.3 Composite Back Trajectories for Sampling Days 11-9
11.2.4 Wind Roses for Sampling Days 11-9
11.3 Pollutants of Interest 11-13
11.4 Concentrations 11-15
11.4.1 2007 Concentration Averages 11-15
11.4.2 Concentration Trends 11-17
11.5 Pearson Correlations 11-23
11.6 Additional Risk Screening Evaluations 11-25
11.6.1 Risk Screening Assessment Using MRLs 11-25
11.6.2 Cancer and Noncancer Surrogate Risk Approximations 11-25
11.6.3 Risk-Based Emissions Assessment 11-30
11.7 Summary of the 2007 Monitoring Data 11-33
12.0 Sites in Indiana 12-1
12.1 Site Characterization 12-1
12.2 Meteorological Characterization 12-11
12.2.1 Climate Summary 12-11
12.2.2 Meteorological Conditions in 2007 12-12
viii
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TABLE OF CONTENTS (Continued)
12.2.3 Composite Back Trajectories for Sampling Days 12-12
12.2.4 Wind Roses for Sampling Days 12-18
12.3 Pollutants of Interest 12-21
12.4 Concentrations 12-22
12.4.1 2007 Concentration Averages 12-23
12.4.2 Concentration Trends 12-24
12.5 Pearson Correlations 12-25
12.6 Additional Risk Screening Evaluations 12-25
12.6.1 Risk Screening Assessment Using MRLs 12-25
12.6.2 Cancer and Noncancer Surrogate Risk Approximations 12-30
12.6.3 Risk-Based Emissions Assessment 12-32
12.7 Summary of the 2007 Monitoring Data 12-38
13.0 Site in Kentucky 13-1
13.1 Site Characterization 13-1
13.2 Meteorological Characterization 13-6
13.2.1 Climate Summary 13-6
13.2.2 Meteorological Conditions in 2007 13-6
13.2.3 Composite Back Trajectories for Sampling Days 13-6
13.2.4 Wind Rose for Sampling Days 13-9
13.3 Pollutants of Interest 13-10
13.4 Concentrations 13-11
13.4.1 2007 Concentration Averages 13-11
13.4.2 Concentration Trends 13-12
13.5 Pearson Correlations 13-12
13.6 Additional Risk Screening Evaluations 13-12
13.6.1 Risk Screening Assessment Using MRLs 13-12
13.6.2 Cancer and Noncancer Surrogate Risk Approximations 13-14
13.6.3 Risk-Based Emissions Assessment 13-14
13.7 Summary of the 2007 Monitoring Data 13-19
IX
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TABLE OF CONTENTS (Continued)
14.0 Site in Massachusetts 14-1
14.1 Site Characterization 14-1
14.2 Meteorological Characterization 14-5
14.2.1 Climate Summary 14-6
14.2.2 Meteorological Conditions in 2007 14-6
14.2.3 Composite Back Trajectories for Sampling Days 14-6
14.2.4 Wind Rose for Sampling Days 14-9
14.3 Pollutants of Interest 14-10
14.4 Concentrations 14-11
14.4.1 2007 Concentration Averages 14-11
14.4.2 Concentration Trends 14-12
14.5 Pearson Correlations 14-14
14.6 Additional Risk Screening Evaluations 14-14
14.6.1 Risk Screening Assessment Using MRLs 14-14
14.6.2 Cancer and Noncancer Risk Approximations 14-14
14.6.3 Risk-Based Emissions Assessment 14-16
14.7 Summary of the 2007 Monitoring Data 14-20
15.0 Sites in Michigan 15-1
15.1 Site Characterization 15-1
15.2 Meteorological Characterization 15-8
15.2.1 Climate Summary 15-8
15.2.2 Meteorological Conditions in 2007 15-8
15.2.3 Composite Back Trajectories for Sampling Days 15-9
15.2.4 Wind Roses for Sampling Days 15-13
15.3 Pollutants of Interest 15-15
15.4 Concentrations 15-16
15.4.1 2007 Concentration Averages 15-16
15.4.2 Concentration Trends 15-18
15.5 Pearson Correlations 15-22
15.6 Additional Risk Screening Evaluations 15-24
x
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TABLE OF CONTENTS (Continued)
15.6.1 Risk Screening Assessment Using MRLs 15-24
15.6.2 Cancer and Noncancer Surrogate Risk Approximations 15-26
15.6.3 Risk-Based Emissions Assessment 15-28
15.7 Summary of the 2007 Monitoring Data 15-32
16.0 Sites in Mississippi 16-1
16.1 Site Characterization 16-1
16.2 Meteorological Characterization 16-8
16.2.1 Climate Summary 16-8
16.2.2 Meteorological Conditions in 2007 16-8
16.2.3 Composite Back Trajectories for Sampling Days 16-10
16.2.4 Wind Roses for Sampling Days 16-10
16.3 Pollutants of Interest 16-14
16.4 Concentrations 16-16
16.4.1 2007 Concentration Averages 16-16
16.4.2 Concentration Trends 16-18
16.5 Pearson Correlations 16-27
16.6 Additional Risk Screening Evaluations 16-29
16.6.1 Risk Screening Assessment Using MRLs 16-29
16.6.2 Cancer and Noncancer Surrogate Risk Approximations 16-29
16.6.3 Risk-Based Emissions Assessment 16-34
16.7 Summary of the 2007 Monitoring Data 16-37
17.0 Site in Missouri 17-1
17.1 Site Characterization 17-1
17.2 Meteorological Characterization 17-5
17.2.1 Climate Summary 17-6
17.2.2 Meteorological Conditions in 2007 17-6
17.2.3 Composite Back Trajectories for Sampling Days 17-6
17.2.4 Wind Rose for Sampling Days 17-9
17.3 Pollutants of Interest 17-10
XI
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TABLE OF CONTENTS (Continued)
17.4 Concentrations 17-11
17.4.1 2007 Concentration Averages 17-11
17.4.2 Concentration Trends 17-13
17.5 Pearson Correlations 17-19
17.6 Additional Risk Screening Evaluations 17-19
17.6.1 Risk Screening Assessment Using MRLs 17-19
17.6.2 Cancer and Noncancer Surrogate Risk Approximations 17-22
17.6.3 Risk-Based Emissions Assessment 17-24
17.7 Summary of the 2007 Monitoring Data 17-27
18.0 Sites in New Jersey 18-1
18.1 Site Characterization 18-1
18.2 Meteorological Characterization 18-12
18.2.1 Climate Summary 18-12
18.2.2 Meteorological Conditions in 2007 18-12
18.2.3 Composite Back Trajectories for Sampling Days 18-13
18.2.4 Wind Roses for Sampling Days 18-13
18.3 Pollutants of Interest 18-21
18.4 Concentrations 18-24
18.4.1 2007 Concentration Averages 18-24
18.4.2 Concentration Trends 18-28
18.5 Pearson Correlations 18-44
18.6 Additional Risk Screening Evaluations 18-47
18.6.1 Risk Screening Assessment Using MRLs 18-47
18.6.2 Cancer and Noncancer Surrogate Risk Approximations 18-48
18.6.3 Risk-Based Emissions Assessment 18-54
18.7 Summary of the 2007 Monitoring Data 18-60
19.0 Sites in New York 19-1
19.1 Site Characterization 19-1
19.2 Meteorological Characterization 19-8
xn
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TABLE OF CONTENTS (Continued)
19.2.1 Climate Summary 19-8
19.2.2 Meteorological Conditions in 2007 19-9
19.2.3 Composite Back Trajectories for Sampling Days 19-9
19.2.4 Wind Roses for Sampling Days 19-13
19.3 Pollutants of Interest 19-15
19.4 Concentrations 19-16
19.4.1 2007 Concentration Averages 19-16
19.4.2 Concentration Trends 19-17
19.5 Pearson Correlations 19-17
19.6 Additional Risk Screening Evaluations 19-17
19.6.1 Risk Screening Assessment Using MRLs 19-19
19.6.2 Cancer andNoncancer Surrogate Risk Approximations 19-19
19.6.3 Risk-Based Emissions Assessment 19-21
19.7 Summary of the 2007 Monitoring Data 19-24
20.0 Sites in Oklahoma 20-1
20.1 Site Characterization 20-1
20.2 Meteorological Characterization 20-11
20.2.1 Climate Summary 20-11
20.2.2 Meteorological Conditions in 2007 20-12
20.2.3 Composite Back Trajectories for Sampling Days 20-12
20.2.4 Wind Roses for Sampling Days 20-18
20.3 Pollutants of Interest 20-18
20.4 Concentrations 20-23
20.4.1 2007 Concentration Averages 20-23
20.4.2 Concentration Trends 20-26
20.5 Pearson Correlations 20-26
20.6 Additional Risk Screening Evaluations 20-29
20.6.1 Risk Screening Assessment Using MRLs 20-29
20.6.2 Cancer andNoncancer Surrogate Risk Approximations 20-31
20.6.3 Risk-Based Emissions Assessment 20-35
20.7 Summary of the 2007 Monitoring Data 20-41
xiii
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TABLE OF CONTENTS (Continued)
21.0 Sites in Puerto Rico 21-1
21.1 Site Characterization 21-1
21.2 Meteorological Characterization 21-8
21.2.1 Climate Summary 21-8
21.2.2 Meteorological Conditions in 2007 21-8
21.2.3 Composite Back Trajectories for Sampling Days 21-10
21.2.4 Wind Roses for Sampling Days 21-10
21.3 Pollutants of Interest 21-14
21.4 Concentrations 21-15
21.4.1 2007 Concentration Averages 21-16
21.4.2 Concentration Trends 21-18
21.5 Pearson Correlations 21-18
21.6 Additional Risk Screening Evaluations 21-18
21.6.1 Risk Screening Assessment Using MRLs 21-20
21.6.2 Cancer andNoncancer Surrogate Risk Approximations 21-20
21.6.3 Risk-Based Emissions Assessment 21-24
21.7 Summary of the 2007 Monitoring Data 21-28
22.0 Site in Rhode Island 22-1
22.1 Site Characterization 22-1
22.2 Meteorological Characterization 22-5
22.2.1 Climate Summary 22-5
22.2.2 Meteorological Conditions in 2007 22-6
22.2.3 Composite Back Trajectories for Sampling Days 22-6
22.2.4 Wind Rose for Sampling Days 22-9
22.3 Pollutants of Interest 22-10
22.4 Concentrations 22-10
22.4.1 2007 Concentration Averages 22-11
22.4.2 Concentration Trends 22-12
22.5 Pearson Correlations 22-12
22.6 Additional Risk Screening Evaluations 22-12
xiv
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TABLE OF CONTENTS (Continued)
22.6.1 Risk Screening Assessment Using MRLs 22-12
22.6.2 Cancer and Noncancer Surrogate Risk Approximations 22-14
22.6.3 Risk-Based Emissions Assessment 22-14
22.7 Summary of the 2007 Monitoring Data 22-19
23.0 Site in South Carolina 23-1
23.1 Site Characterization 23-1
23.2 Meteorological Characterization 23-5
23.2.1 Climate Summary 23-5
23.2.2 Meteorological Conditions in 2007 23-6
23.2.3 Composite Back Trajectories for Sampling Days 23-6
23.2.4 Wind Rose for Sampling Days 23-9
23.3 Pollutants of Interest 23-10
23.4 Concentrations 23-10
23.4.1 2007 Concentration Averages 23-11
23.4.2 Concentration Trends 23-11
23.5 Pearson Correlations 23-12
23.6 Additional Risk Screening Evaluations 23-12
23.6.1 Risk Screening Assessment Using MRLs 23-12
23.6.2 Cancer and Noncancer Surrogate Risk Approximations 23-12
23.6.3 Risk-Based Emissions Assessment 23-14
23.7 Summary of the 2007 Monitoring Data 23-18
24.0 Sites in South Dakota 24-1
24.1 Site Characterization 24-1
24.2 Meteorological Characterization 24-8
24.2.1 Climate Summary 24-8
24.2.2 Meteorological Conditions in 2007 24-8
24.2.3 Composite Back Trajectories for Sampling Days 24-9
24.2.4 Wind Roses for Sampling Days 24-13
24.3 Pollutants of Interest 24-14
xv
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TABLE OF CONTENTS (Continued)
24.4 Concentrations 24-16
24.4.1 2007 Concentration Averages 24-16
24.4.2 Concentration Trends 24-18
24.5 Pearson Correlations 24-30
24.6 Additional Risk Screening Evaluations 24-30
24.6.1 Risk Screening Assessment Using MRLs 24-30
24.6.2 Cancer and Noncancer Surrogate Risk Approximations 24-35
24.6.3 Risk-Based Emissions Assessment 24-37
24.7 Summary of the 2007 Monitoring Data 24-41
25.0 Sites in Tennessee 25-1
25.1 Site Characterization 25-1
25.2 Meteorological Characterization 25-7
25.2.1 Climate Summary 25-7
25.2.2 Meteorological Conditions in 2007 25-7
25.2.3 Composite Back Trajectories for Sampling Days 25-9
25.2.4 Wind Roses for Sampling Days 25-9
25.3 Pollutants of Interest 25-13
25.4 Concentrations 25-13
25.4.1 2007 Concentration Averages 25-14
25.4.2 Concentration Trends 25-16
25.5 Pearson Correlations 25-21
25.6 Additional Risk Screening Evaluations 25-21
25.6.1 Risk Screening Assessment Using MRLs 25-21
25.6.2 Cancer and Noncancer Surrogate Risk Approximations 25-23
25.6.3 Risk-Based Emissions Assessment 25-26
25.7 Summary of the 2007 Monitoring Data 25-30
26.0 Sites in Texas 26-1
26.1 Site Characterization 26-1
26.2 Meteorological Characterization 26-8
xvi
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TABLE OF CONTENTS (Continued)
26.2.1 Climate Summary 26-8
26.2.2 Meteorological Conditions in 2007 26-9
26.2.3 Composite Back Trajectories for Sampling Days 26-9
26.2.4 Wind Roses for Sampling Days 26-13
26.3 Pollutants of Interest 26-14
26.4 Concentrations 26-16
26.4.1 2007 Concentration Averages 26-16
26.4.2 Concentration Trends 26-18
26.5 Pearson Correlations 26-18
26.6 Additional Risk Screening Evaluations 26-20
26.6.1 Risk Screening Assessment Using MRLs 26-20
26.6.2 Cancer and Noncancer Surrogate Risk Approximations 26-20
26.6.3 Risk-Based Emissions Assessment 26-24
26.7 Summary of the 2007 Monitoring Data 26-27
27.0 Site in Utah 27-1
27.1 Site Characterization 27-1
27.2 Meteorological Characterization 27-5
27.2.1 Climate Summary 27-5
27.2.2 Meteorological Conditions in 2007 27-6
27.2.3 Composite Back Trajectories for Sampling Days 27-6
27.2.4 Wind Rose for Sampling Days 27-9
27.3 Pollutants of Interest 27-10
27.4 Concentrations 27-11
27.4.1 2007 Concentration Averages 27-11
27.4.2 Concentration Trends 27-13
27.5 Pearson Correlations 27-20
27.6 Additional Risk Screening Evaluations 27-20
27.6.1 Risk Screening Assessment Using MRLs 27-22
27.6.2 Cancer and Noncancer Surrogate Risk Approximations 27-22
27.6.3 Risk-Based Emissions Assessment 27-25
xvn
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TABLE OF CONTENTS (Continued)
27.7 Summary of the 2007 Monitoring Data 27-29
28.0 Site in Vermont 28-1
28.1 Site Characterization 28-1
28.2 Meteorological Characterization 28-5
28.2.1 Climate Summary 28-6
28.2.2 Meteorological Conditions in 2007 28-6
28.2.3 Composite Back Trajectories for Sampling Days 28-6
28.2.4 Wind Rose for Sampling Days 28-9
28.3 Pollutants of Interest 28-10
28.4 Concentrations 28-11
28.4.1 2007 Concentration Averages 28-11
28.4.2 Concentration Trends 28-12
28.5 Pearson Correlations 28-12
28.6 Additional Risk Screening Evaluations 28-12
28.6.1 Risk Screening Assessment Using MRLs 28-12
28.6.2 Cancer and Noncancer Surrogate Risk Approximations 28-14
28.6.3 Risk-Based Emissions Assessment 28-16
28.7 Summary of the 2007 Monitoring Data 28-19
29.0 Site in Washington 29-1
29.1 Site Characterization 29-1
29.2 Meteorological Characterization 29-5
29.2.1 Climate Summary 29-6
29.2.2 Meteorological Conditions in 2007 29-6
29.2.3 Composite Back Trajectories for Sampling Days 29-6
29.2.4 Wind Rose for Sampling Days 29-9
29.3 Pollutants of Interest 29-10
29.4 Concentrations 29-11
29.4.1 2007 Concentration Averages 29-11
29.4.2 Concentration Trends 29-13
xvin
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TABLE OF CONTENTS (Continued)
29.5 Pearson Correlations 29-13
29.6 Additional Risk Screening Evaluations 29-13
29.6.1 Risk Screening Assessment Using MRLs 29-13
29.6.2 Cancer and Noncancer Surrogate Risk Approximations 29-15
29.6.3 Risk-Based Emissions Assessment 29-18
29.7 Summary of the 2007 Monitoring Data 29-22
30.0 Site in Wisconsin 30-1
30.1 Site Characterization 30-1
30.2 Meteorological Characterization 30-5
30.2.1 Climate Summary 30-5
30.2.2 Meteorological Conditions in 2007 30-6
30.2.3 Composite Back Trajectories for Sampling Days 30-6
30.2.4 Wind Rose for Sampling Days 30-9
30.3 Pollutants of Interest 30-10
30.4 Concentrations 30-10
30.4.1 2007 Concentration Averages 30-11
30.4.2 Concentration Trends 30-12
30.5 Pearson Correlations 30-12
30.6 Additional Risk Screening Evaluations 30-12
30.6.1 Risk Screening Assessment Using MRLs 30-12
30.6.2 Cancer and Noncancer Surrogate Risk Approximations 30-14
30.6.3 Risk-Based Emissions Assessment 30-14
30.7 Summary of the 2007 Monitoring Data 30-19
31.0 Data Quality 31-1
31.1 Method Precision 31-1
31.1.1 VOC Method Precision 31-5
31.1.2 SNMOC Method Precision 31-34
31.1.3 Carbonyl Compounds Method Precision 31-44
31.1.4 Metals Method Precision 31-54
31.1.5 Hexavalent Chromium Method Precision 31-57
31.1.6 SVOC Method Precision 31-58
xix
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TABLE OF CONTENTS (Continued)
31.2 Analytical Precision 31-61
31.2.1 VOC Analytical Precision 31-61
31.2.2 SNMOC Analytical Precision 31-89
31.2.3 Carbonyl Compounds Analytical Precision 31-99
31.2.4 Metals Analytical Precision 31-109
31.2.5 Hexavalent Chromium Analytical Precision 31-112
31.2.6 SVOC Analytical Precision 31-113
31.3 Accuracy 31-116
32.0 Summary of Results and Recommendations 32-1
32.1 Summary of Results 32-1
32.1.1 National-level Summary 32-1
32.1.2 State-level Summary 32-3
32.1.3 Composite Site-level Summary 32-31
32.1.4 Data Quality Summary 32-32
32.2 Recommendations 32-32
33.0 References 33-1
xx
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List of Appendices
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G
Appendix H
Appendix I
Appendix J
Appendix K
Appendix L
Appendix M
Appendix N
Appendix O
Appendix P
TABLE OF CONTENTS (Continued)
AQS Site Descriptions for the 2007 NATTS and UATMP
Monitoring Sites A-l
2007 Range of Detection Limits B-l
2007 VOC Raw Data C-l
2007 SNMOC/TNMOC Raw Data D-l
2007 Carbonyl Raw Data E-l
2007 SVOC Raw Data F-l
2007 Metal Raw Data G-l
2007 Hexavalent Chromium Raw Data H-l
2007 Summary of Invalidated NATTS/UATMP Samples by Site 1-1
2007 Summary Statistics for VOC Monitoring J-l
2007 Summary Statistics for SNMOC Monitoring K-l
2007 Summary Statistics for Carbonyl Monitoring L-l
2007 Summary Statistics for SVOC Monitoring M-l
2007 Summary Statistics for Metal Monitoring N-l
2007 Summary Statistics for Hexavalent Chromium Monitoring O-l
Risk Factors Used Throughout the 2007 NATTS/UATMP Report P-l
xxi
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LIST OF FIGURES
Page
2-1 Locations of the 2007 NATTS and UATMP Monitoring Sites 2-2
4-1 Comparison of Concentration Ratios for BTEX Compounds vs. Roadside Study 4-38
4-2 Coefficient of Variation Analysis of 1,3-Butadiene Across 27 Sites 4-42
4-3 Coefficient of Variation Analysis of Acetaldehyde Across 33 Sites 4-43
4-4 Coefficient of Variation Analysis of Acrolein Across 27 Sites 4-44
4-5 Coefficient of Variation Analysis of Acrylonitrile Across 27 Sites 4-45
4-6 Coefficient of Variation Analysis of Arsenic Across 11 Sites 4-46
4-7 Coefficient of Variation Analysis of Benzene Across 27 Sites 4-47
4-8 Coefficient of Variation Analysis of Carbon Tetrachloride Across 27 Sites 4-48
4-9 Coefficient of Variation Analysis of Formaldehyde Across 33 Sites 4-49
4-10 Coefficient of Variation Analysis of Manganese Across 11 Sites 4-50
4-11 Coefficient of Variation Analysis ofp-Dichlorobenzene Across 27 Sites 4-51
4-12 Coefficient of Variation Analysis of Tetrachloroethylene Across 27 Sites 4-52
4-13 Comparison of Average Seasonal 1,3-Butadiene Concentrations by Season 4-54
4-14 Comparison of Average Seasonal Acetaldehyde Concentrations by Season 4-56
4-15 Comparison of Average Seasonal Acrolein Concentrations by Season 4-58
4-16 Comparison of Average Seasonal Acrylonitrile Concentrations by Season 4-60
4-17 Comparison of Average Seasonal Arsenic PMi0 Concentrations by Season 4-62
4-18 Comparison of Average Seasonal Arsenic TSP Concentrations by Season 4-63
4-19 Comparison of Average Seasonal Benzene Concentrations by Season 4-64
4-20 Comparison of Average Seasonal Carbon Tetrachloride Concentrations by Season ... 4-66
4-21 Comparison of Average Seasonal Formaldehyde Concentrations by Season 4-68
4-22 Comparison of Average Seasonal Manganese PMio Concentrations by Season 4-70
4-23 Comparison of Average Seasonal Manganese TSP Concentrations by Season 4-71
4-24 Comparison of Average Seasonal />-Dichlorobenzene Concentrations by Season 4-72
4-25 Comparison of Average Seasonal Tetrachloroethylene Concentrations by Season 4-74
5-1 Phoenix, Arizona (PXSS) Monitoring Site 5-2
5-2 South Phoenix, Arizona (SPAZ) Monitoring Site 5-3
5-3 NEI Point Sources Located Within 10 Miles of PXSS and SPAZ 5-4
5-4 Composite Back Trajectory Map for PXSS 5-10
5-5 Composite Back Trajectory Map for SPAZ 5-11
5-6 Wind Rose for PXSS Sampling Days 5-12
5-7 Wind Rose for SPAZ SamplingDays 5-12
6-1 Los Angeles, California (CELA) Monitoring Site 6-2
6-2 Rubidoux, California (RUCA) Monitoring Site 6-3
6-3 NEI Point Sources Located Within 10 Miles of CELA 6-4
6-4 NEI Point Sources Located Within 10 Miles of RUCA 6-5
6-5 Composite Back Trajectory Map for CELA 6-11
6-6 Composite Back Trajectory Map for RUCA 6-12
6-7 Wind Rose for CELA SamplingDays 6-13
6-8 Wind Rose for RUCA Sampling Days 6-14
xxii
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LIST OF FIGURES (Continued)
Page
7-1 Grand Junction, Colorado (GPCO) Monitoring Site 7-2
7-2 NEI Point Sources Located Within 10 Miles of GPCO 7-3
7-3 Composite Back Trajectory Map for GPCO 7-8
7-4 Wind Rose for GPCO Sampling Days 7-9
8-1 Washington, D.C. (WADC) Monitoring Site 8-2
8-2 NEI Point Sources Located Within 10 Miles of WADC 8-3
8-3 Composite Back Trajectory Map for WADC 8-8
8-4 Wind Rose for WADC SamplingDays 8-9
9-1 St. Petersburg, Florida (AZFL) Monitoring Site 9-2
9-2 Tampa, Florida (GAFL) Monitoring Site 9-3
9-3 Pinellas Park, Florida (SKFL) Monitoring Site 9-4
9-4 Plant City, Florida (SYFL) Monitoring Site 9-5
9-5 Winter Park, Florida (ORFL) Monitoring Site 9-6
9-6 Davie, Florida (FLFL) Monitoring Site 9-7
9-7 NEI Point Sources Located Within 10 Miles of the Tampa/St. Petersburg, Florida
Monitoring Sites 9-8
9-8 NEI Point Sources Located Within 10 Miles of ORFL 9-9
9-9 NEI Point Sources Located Within 10 Miles of FLFL 9-10
9-10 Composite Back Trajectory Map for AZFL 9-19
9-11 Composite Back Trajectory Map for GAFL 9-20
9-12 Composite Back Trajectory Map for SKFL 9-21
9-13 Composite Back Trajectory Map for SYFL 9-22
9-14 Composite Back Trajectory Map for ORFL 9-23
9-15 Composite Back Trajectory Map for FLFL 9-24
9-16 Wind Rose for AZFL SamplingDays 9-26
9-17 Wind Rose for FLFL Sampling Days 9-26
9-18 Wind Rose for GAFL Sampling Days 9-27
9-19 Wind Rose for ORFL Sampling Days 9-27
9-20 Wind Rose for SKFL Sampling Days 9-28
9-21 Wind Rose for SYFL Sampling Days 9-28
9-22 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at AZFL 9-35
9-23 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at GAFL 9-36
9-24 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at ORFL 9-37
10-1 Decatur, Georgia (SDGA) Monitoring Site 10-2
10-2 NEI Point Sources Located Within 10 Miles of SDGA 10-3
10-3 Composite Back Trajectory Map for SDGA 10-8
10-4 Wind Rose for SDGA Sampling Days 10-9
xxin
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LIST OF FIGURES (Continued)
Page
11-1 Northbrook, Illinois (NBIL) Monitoring Site 11-2
11-2 Schiller Park, Illinois (SPIL) Monitoring Site 11-3
11-3 NEI Point Sources Located Within 10 Miles of NBIL and SPIL 11-4
11-4 Composite Back Trajectory Map for NBIL 11-10
11-5 Composite Back Trajectory Map for SPIL 11-11
11-6 Wind Rose for NBIL Sampling Days 11-12
11-7 Wind Rose for SPIL Sampling Days 11-12
11-8 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
NBIL 11-18
11-9 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at NBIL 11-19
11-10 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
SPIL 11-20
11-11 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at SPIL 11-21
12-1 Indianapolis, Indiana (IDIN) Monitoring Site 12-2
12-2 Indianapolis, Indiana (ININ) Monitoring Site 12-3
12-3 Indianapolis, Indiana (WPIN) Monitoring Site 12-4
12-4 Gary, Indiana (INDEM) Monitoring Site 12-5
12-5 NEI Point Sources Located Within 10 Miles of IDIN, ININ, and WPIN 12-6
12-6 NEI Point Sources Located Within 10 Miles of INDEM 12-7
12-7 Composite Back Trajectory Map for IDIN 12-14
12-8 Composite Back Trajectory Map for ININ 12-15
12-9 Composite Back Trajectory Map for WPIN 12-16
12-10 Composite Back Trajectory Map for INDEM 12-17
12-11 Wind Rose for IDIN Sampling Days 12-19
12-12 Wind Rose for ININ Sampling Days 12-19
12-13 Wind Rose for WPIN Sampling Days 12-20
12-14 Wind Rose for INDEM Sampling Days 12-20
12-15 Formaldehyde Pollution Rose for INDEM 12-29
13-1 Hazard, Kentucky (HAKY) Monitoring Site 13-2
13-2 NEI Point Sources Located Within 10 Miles of HAKY 13-3
13-3 Composite Back Trajectory Map for HAKY 13-8
13-4 Wind Rose for HAKY Sampling Days 13-9
14-1 Boston, Massachusetts (BOMA) Monitoring Site 14-2
14-2 NEI Point Sources Located Within 10 Miles of BOMA 14-3
14-3 Composite Back Trajectory Map for BOMA 14-8
14-4 Wind Rose for BOMA Sampling Days 14-9
14-5 Three-Year Rolling Statistical Metrics for Arsenic (PMio) Concentrations
Measured at BOMA 14-13
xxiv
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LIST OF FIGURES (Continued)
Page
15-1 Dearborn, Michigan (DEMI) Monitoring Site 15-2
15-2 Sault Sainte Marie, Michigan (ITCMI) Monitoring Site 15-3
15-3 NEI Point Sources Located Within 10 Miles of DEMI 15-4
15-4 NEI Point Sources Located Within 10 Miles of ITCMI 15-5
15-5 Composite Back Trajectory Map for DEMI 15-11
15-6 Composite Back Trajectory Map for ITCMI 15-12
15-7 Wind Rose for DEMI Sampling Days 15-14
15-8 Wind Rose for ITCMI Sampling Days 15-14
15-9 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
DEMI 15-19
15-10 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at DEMI 15-20
15-11 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at DEMI 15-21
16-1 Gulfport, Mississippi (GPMS) Monitoring Site 16-2
16-2 Tupelo, Mississippi (TUMS) Monitoring Site 16-3
16-3 NEI Point Sources Located Within 10 Miles of GPMS 16-4
16-4 NEI Point Sources Located Within 10 Miles of TUMS 16-5
16-5 Composite Back Trajectory Map for GPMS 16-11
16-6 Composite Back Trajectory Map for TUMS 16-12
16-7 Wind Rose for GPMS Sampling Days 16-13
16-8 Wind Rose for TUMS Sampling Days 16-13
16-9 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
GPMS 16-19
16-10 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at GPMS 16-20
16-11 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at GPMS 16-21
16-12 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
TUMS 16-22
16-13 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at TUMS 16-23
16-14 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at TUMS 16-24
17-1 St. Louis, Missouri (S4MO) Monitoring Site 17-2
17-2 NEI Point Sources Located Within 10 Miles of S4MO 17-3
17-3 Composite Back Trajectory Map for S4MO 17-8
17-4 Wind Rose for S4MO Sampling Days 17-9
17-5 Three-Year Rolling Statistical Metrics for Arsenic Concentrations Measured at
S4MO 17-14
17-6 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
S4MO 17-15
XXV
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LIST OF FIGURES (Continued)
Page
17-7 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at S4MO 17-16
17-8 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at S4MO 17-17
18-1 Camden, New Jersey (CANJ) Monitoring Site 18-2
18-2 Chester, New Jersey (CHNJ) Monitoring Site 18-3
18-3 Elizabeth, New Jersey (ELNJ) Monitoring Site 18-4
18-4 New Brunswick, New Jersey (NBNJ) Monitoring Site 18-5
18-5 NEI Point Sources Located Within 10 Miles of CANJ 18-6
18-6 NEI Point Sources Located Within 10 Miles of CHNJ 18-7
18-7 NEI Point Sources Located Within 10 Miles of ELNJ and NBNJ 18-8
18-8 Composite Back Trajectory Map for CANJ 18-15
18-9 Composite Back Trajectory Map for CHNJ 18-16
18-10 Composite Back Trajectory Map for ELNJ 18-17
18-11 Composite Back Trajectory Map for NBNJ 18-18
18-12 Wind Rose for CANJ Sampling Days 18-19
18-13 Wind Rose for CHNJ Sampling Days 18-19
18-14 Wind Rose for ELNJ Sampling Days 18-20
18-15 Wind Rose for NBNJ Sampling Days 18-20
18-16 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
CANJ 18-29
18-17 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at CANJ 18-30
18-18 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at CANJ 18-31
18-19 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
CHNJ 18-32
18-20 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at CHNJ 18-33
18-21 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at CHNJ 18-34
18-22 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
ELNJ 18-35
18-23 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at ELNJ 18-36
18-24 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at ELNJ 18-37
18-25 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
NBNJ 18-38
18-26 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at NBNJ 18-39
xxvi
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LIST OF FIGURES (Continued)
Page
18-27 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at NBNJ 18-40
19-1 Bronx, New York (BXNY) Monitoring Site 19-2
19-2 Rochester, New York (ROCH) Monitoring Site 19-3
19-3 NEI Point Sources Located Within 10 Miles of BXNY 19-4
19-4 NEI Point Sources Located Within 10 Miles of ROCH 19-5
19-5 Composite Back Trajectory Map for BXNY 19-11
19-6 Composite Back Trajectory Map for ROCH 19-12
19-7 Wind Rose for BXNY Sampling Days 19-14
19-8 Wind Rose for ROCH Sampling Days 19-14
20-1 Cherokee Heights, Pryor, Oklahoma (CNEP) Monitoring Site 20-2
20-2 Tulsa, Oklahoma (TOOK) Monitoring Site 20-3
20-3 Tulsa, Oklahoma (TSOK) Monitoring Site 20-4
20-4 Tulsa, Oklahoma (TUOK) Monitoring Site 20-5
20-5 NEI Point Sources Located Within 10 Miles of CNEP 20-6
20-6 NEI Point Sources Located Within 10 Miles of TOOK, TSOK and TUOK 20-7
20-7 Composite Back Trajectory Map for CNEP 20-14
20-8 Composite Back Trajectory Map for TOOK 20-15
20-9 Composite Back Trajectory Map for TSOK 20-16
20-10 Composite Back Trajectory Map for TUOK 20-17
20-11 Wind Rose for CNEP Sampling Days 20-19
20-12 Wind Rose for TOOK Sampling Days 20-19
20-13 Wind Rose for TSOK Sampling Days 20-20
20-14 Wind Rose for TUOK Sampling Days 20-20
21-1 Barceloneta, Puerto Rico (BAPR) Monitoring Site 21-2
21-2 San Juan, Puerto Rico (SJPR) Monitoring Site 21-3
21-3 NEI Point Sources Located Within 10 Miles of BAPR 21-4
21-4 NEI Point Sources Located Within 10 Miles of SJPR 21-5
21-5 Composite Back Trajectory Map for BAPR 21-11
21-6 Composite Back Trajectory Map for SJPR 21-12
21-7 Wind Rose for BAPR Sampling Days 21-13
21-8 Wind Rose for SJPR Sampling Days 21-13
22-1 Providence, Rhode Island (PRRI) Monitoring Site 22-2
22-2 NEI Point Sources Located Within 10 Miles of PRRI 22-3
22-3 Composite Back Trajectory Map for PRRI 22-8
22-4 Wind Rose for PRRI Sampling Days 22-9
23-1 Chesterfield, South Carolina (CHSC) Monitoring Site 23-2
23-2 NEI Point Sources Located Within 10 Miles of CHSC 23-3
23-3 Composite Back Trajectory Map for CHSC 23-8
xxvii
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LIST OF FIGURES (Continued)
Page
23-4 Wind Rose for CHSC Sampling Days 23-9
24-1 Custer, South Dakota (CUSD) Monitoring Site 24-2
24-2 Sioux Falls, South Dakota (SFSD) Monitoring Site 24-3
24-3 NEI Point Sources Located Within 10 Miles of CUSD 24-4
24-4 NEI Point Sources Located Within 10 Miles of SFSD 24-5
24-5 Composite Back Trajectory Map for CUSD 24-11
24-6 Composite Back Trajectory Map for SFSD 24-12
24-7 Wind Rose for CUSD Sampling Days 24-13
24-8 Wind Rose for SFSD Sampling Days 24-14
24-9 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
CUSD(SNMOC) 24-19
24-10 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
CUSD(TO-IS) 24-20
24-11 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at CUSD 24-21
24-12 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at CUSD 24-22
24-13 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
SFSD(SNMOC) 24-23
24-14 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
SFSD(TO-IS) 24-24
24-15 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at SFSD 24-25
24-16 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at SFSD 24-26
24-17 Formaldehyde Pollution Rose for SFSD 24-34
25-1 Loudon, Tennessee (LDTN) Monitoring Site 25-2
25-2 Loudon, Tennessee (MSTN) Monitoring Site 25-3
25-3 NEI Point Sources Located Within 10 Miles of LDTN and MSTN 25-4
25-4 Composite Back Trajectory Map for LDTN 25-10
25-5 Composite Back Trajectory Map for MSTN 25-11
25-6 Wind Rose for LDTN Sampling Days 25-12
25-7 Wind Rose for MSTN Sampling Days 25-12
25-8 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
LDTN 25-18
25-9 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at LDTN 25-19
25-10 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at LDTN 25-20
26-1 Deer Park, Texas (CAMS 35) Monitoring Site 26-2
26-2 Karnack, Texas (CAMS 85) Monitoring Site 26-3
xxviii
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LIST OF FIGURES (Continued)
Page
26-3 NEI Point Sources Located Within 10 Miles of CAMS 35 26-4
26-4 NEI Point Sources Located Within 10 Miles of CAMS 85 26-5
26-5 Composite Back Trajectory Map for CAMS 35 26-11
26-6 Composite Back Trajectory Map for CAMS 85 26-12
26-7 Wind Rose for CAMS 3 5 SamplingDays 26-13
26-8 Wind Rose for CAMS 85 SamplingDays 26-14
27-1 Bountiful, Utah (BTUT) Monitoring Site 27-2
27-2 NEI Point Sources Located Within 10 Miles of BTUT 27-3
27-3 Composite Back Trajectory Map for BTUT 27-8
27-4 Wind Rose for BTUT SamplingDays 27-9
27-5 Three-Year Rolling Statistical Metrics for Arsenic (PMio) Concentrations
Measured at BTUT 27-14
27-6 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
BTUT(SNMOC) 27-15
27-7 Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at
BTUT(TO-IS) 27-16
27-8 Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations
Measured at BTUT 27-17
27-9 Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations
Measured at BTUT 27-18
28-1 Underbill, Vermont (UNVT) Monitoring Site 28-2
28-2 NEI Point Sources Located Within 10 Miles of UNVT 28-3
28-3 Composite Back Trajectory Map for UNVT 28-8
28-4 Wind Rose for UNVT Sampling Days 28-9
29-1 Seattle, Washington (SEWA) Monitoring Site 29-2
29-2 NEI Point Sources Located Within 10 Miles of SEWA 29-3
29-3 Composite Back Trajectory Map for SEWA 29-8
29-4 Wind Rose for SEWA Sampling Days 29-9
30-1 Mayville, Wisconsin (MVWI) Monitoring Site 30-2
30-2 NEI Point Sources Located Within 10 Miles of MVWI 30-3
30-3 Composite Back Trajectory Map for MVWI 30-8
30-4 Wind Rose for MVWI Sampling Days 30-9
XXIX
-------
LIST OF TABLES
1-1 Organization of the 2007 National Monitoring Programs (NATTS and UATMP)
Report 1-4
2-1 Descriptions of the 2007 NATTS and UATMP Monitoring Sites 2-4
2-2 2007 NATTS and UATMP Monitoring Sites and Past Program Participation 2-9
2-3 VOC Method Detection Limits 2-15
2-4 SNMOC Method Detection Limits 2-16
2-5 Carbonyl Method Detection Limits 2-18
2-6 SVOC Method Detection Limits 2-18
2-7 Metals Method Detection Limits 2-20
2-8 Hexavalent Chromium Method Detection Limit 2-20
2-9 Sampling Schedules and Completeness 2-22
3-1 Overview and Lay out of Data Presented 3-1
4-1 Statistical Summaries of the VOC Concentrations 4-2
4-2 Statistical Summaries of the Carbonyl Compound Concentrations 4-4
4-3 Statistical Summaries of the SVOC Concentrations 4-5
4-4 Statistical Summaries of the SNMOC Concentrations 4-6
4-5 Statistical Summaries of the Metals Concentrations 4-9
4-6 Statistical Summaries of the Hexavalent Chromium Concentrations 4-10
4-7 Program-Level Risk Screening Summary 4-16
4-8 Site-Specific Risk Screening Comparison 4-17
4-9 Daily Average Comparison of the Carbonyl Pollutants of Interest 4-20
4-10 Daily Average Comparison of the Metal Pollutants of Interest 4-21
4-11 Daily Average Comparison of the VOC Pollutants of Interest 4-22
4-12 Program-Level MRL Risk Assessment Summary 4-24
4-13 Summary of Pearson Correlations between the Pollutants of Interest and Selected
Meteorological Parameters 4-26
4-14 Summary of Mobile Source Information by Monitoring Site 4-29
4-15 Average Ethylene-to-Acetylene Ratios for Sites that Measured SNMOC 4-36
4-16 Comparison of Concentration Ratios for BTEX Compounds vs. Roadside Study 4-37
4-17 Greenhouse Gases 4-76
5-1 Geographical Information for the Arizona Monitoring Sites 5-5
5-2 Population, Motor Vehicle, and Traffic Information for the Arizona Monitoring
Sites 5-6
5-3 Average Meteorological Conditions near the Arizona Monitoring Sites 5-8
5-4 Comparison of Measured Concentrations and EPA Screening Values for the
Arizona Monitoring Sites 5-14
5-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Arizona Monitoring Sites 5-16
XXX
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LIST OF TABLES (Continued)
Page
5-6 Pearson Correlations for Selected Meteorological Parameters and the Pollutants
of Interest for the Arizona Monitoring Sites 5-18
5-7 MRL Risk Screening Assessment Summary for the Arizona Monitoring Sites 5-20
5-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Arizona 5-22
5-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Arizona 5-25
5-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Arizona 5-26
6-1 Geographical Information for the California Monitoring Sites 6-6
6-2 Population, Motor Vehicle, and Traffic Information for the California Monitoring
Sites 6-7
6-3 Average Meteorological Conditions near the California Monitoring Sites 6-10
6-4 Comparison of Measured Concentrations and EPA Screening Values for the
California Monitoring Sites 6-15
6-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the California Monitoring Sites 6-16
6-6 Pearson Correlations Between Selected Meteorological Parameters and Pollutants
of Interest for the California Monitoring Sites 6-18
6-7 Cancer and Noncancer Risk Summary for the Monitoring Sites in California 6-20
6-8 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
California 6-22
6-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
California 6-23
7-1 Geographical Information for the Colorado Monitoring Site 7-4
7-2 Population, Motor Vehicle, and Traffic Information for the Colorado Monitoring
Site 7-5
7-3 Average Meteorological Conditions near the Colorado Monitoring Site 7-7
7-4 Comparison of Measured Concentrations and EPA Screening Values for the
Colorado Monitoring Site 7-11
7-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Colorado Monitoring Site 7-12
7-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Colorado Monitoring Site 7-14
7-7 MRL Risk Screening Assessment Summary for the Colorado Monitoring Site 7-16
7-8 Cancer and Noncancer Risk Summary for the Monitoring Site in Colorado 7-17
7-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Colorado 7-19
xxxi
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LIST OF TABLES (Continued)
Page
7-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Colorado 7-20
8-1 Geographical Information for the Washington, D.C. Monitoring Site 8-4
8-2 Population, Motor Vehicle, and Traffic Information for the Washington, D.C.
Monitoring Site 8-5
8-3 Average Meteorological Conditions near the Washington, D.C. Monitoring Site 8-7
8-4 Comparison of Measured Concentrations and EPA Screening Values for the
Washington, D.C. Monitoring Site 8-10
8-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Washington, D.C. Monitoring Site 8-11
8-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Washington, D.C. Monitoring Site 8-13
8-7 Cancer and Noncancer Risk Summary for the Monitoring Site in Washington, D.C... 8-15
8-8 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Washington, D.C 8-16
8-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Washington, D.C 8-17
9-1 Geographical Information for the Florida Monitoring Sites 9-11
9-2 Population, Motor Vehicle, and Traffic Information for the Florida Monitoring
Sites 9-15
9-3 Average Meteorological Conditions near the Florida Monitoring Sites 9-18
9-4 Comparison of Measured Concentrations and EPA Screening Values for the
Florida Monitoring Sites 9-30
9-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Florida Monitoring Sites 9-32
9-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Florida Monitoring Sites 9-39
9-7 Cancer and Noncancer Risk Summary for the Monitoring Sites in Florida 9-41
9-8 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Florida 9-44
9-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Florida 9-47
10-1 Geographical Information for the Georgia Monitoring Site 10-4
10-2 Population, Motor Vehicle, and Traffic Information for the Georgia Monitoring
Site 10-5
10-3 Average Meteorological Conditions near the Georgia Monitoring Site 10-7
xxxii
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LIST OF TABLES (Continued)
Page
10-4 Comparison of Measured Concentrations and EPA Screening Values for the
Georgia Monitoring Site 10-10
10-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Georgia Monitoring Site 10-11
10-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Georgia Monitoring Site 10-13
10-7 Cancer and Noncancer Risk Summary for the Monitoring Site in Georgia 10-15
10-8 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Georgia 10-16
10-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Georgia 10-17
11-1 Geographical Information for the Illinois Monitoring Sites 11-5
11-2 Population, Motor Vehicle, and Traffic Information for the Illinois Monitoring
Sites 11-6
11-3 Average Meteorological Conditions near the Illinois Monitoring Sites 11-8
11-4 Comparison of Measured Concentrations and EPA Screening Values for the
Illinois Monitoring Sites 11-14
11-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Illinois Monitoring Sites 11-16
11-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Illinois Monitoring Sites 11-24
11-7 MRL Risk Screening Assessment Summary for the Illinois Monitoring Sites 11-26
11-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Illinois 11-28
11-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Illinois 11-31
11-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Illinois 11-32
12-1 Geographical Information for the Indiana Monitoring Sites 12-8
12-2 Population, Motor Vehicle, and Traffic Information for the Indiana Monitoring
Sites 12-11
12-3 Average Meteorological Conditions near the Indiana Monitoring Sites 12-13
12-4 Comparison of Measured Concentrations and EPA Screening Values for the
Indiana Monitoring Sites 12-22
12-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Indiana Monitoring Sites 12-24
12-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Indiana Monitoring Sites 12-26
12-7 MRL Risk Screening Assessment Summary for the Indiana Monitoring Sites 12-27
xxxiii
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LIST OF TABLES (Continued)
Page
12-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Indiana 12-31
12-9 Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Indiana 12-33
12-10 Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Indiana 12-35
13-1 Geographical Information for the Kentucky Monitoring Site 13-4
13-2 Population, Motor Vehicle, and Traffic Information for the Kentucky Monitoring
Site 13-5
13-3 Average Meteorological Conditions near the Kentucky Monitoring Site 13-7
13-4 Comparison of Measured Concentrations and EPA Screening Values for the
Kentucky Monitoring Site 13-10
13-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Kentucky Monitoring Site 13-11
13-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Kentucky Monitoring Site 13-13
13-7 Cancer and Noncancer Risk Summary for the Monitoring Site in Kentucky 13-15
13-8 Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Kentucky 13-16
13-9 Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Kentucky 13-17
14-1 Geographical Information for the Massachusetts Monitoring Site 14-4
14-2 Population, Motor Vehicle, and Traffic Information for the Massachusetts
Monitoring Site 14-5
14-3 Average Meteorological Conditions near the Massachusetts Monitoring Site 14-7
14-4 Comparison of Measured Concentrations and EPA Screening Values for the
Massachusetts Monitoring Site 14-10
14-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Massachusetts Monitoring Site 14-12
14-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Massachusetts Monitoring Site 14-15
14-7 Cancer and Noncancer Risk Summary for the Monitoring Site in Massachusetts 14-17
14-8 Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Massachusetts 14-18
14-9 Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Massachusetts 14-19
xxxiv
-------
LIST OF TABLES (Continued)
Page
15-1 Geographical Information for the Michigan Monitoring Sites 15-6
15-2 Population, Motor Vehicle, and Traffic Information for the Michigan Monitoring
Sites 15-7
15-3 Average Meteorological Conditions near the Michigan Monitoring Sites 15-10
15-4 Comparison of Measured Concentrations and EPA Screening Values for the
Michigan Monitoring Sites 15-15
15-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Michigan Monitoring Sites 15-17
15-6 Pearson Correlations Between Selected Meteorological Parameters and Pollutants
of Interest for the Michigan Monitoring Sites 15-23
15-7 MRL Risk Screening Assessment Summary for the Michigan Monitoring Sites 15-25
15-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Michigan 15-27
15-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Michigan 15-29
15-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Michigan 15-30
16-1 Geographical Information for the Mississippi Monitoring Sites 16-6
16-2 Population, Motor Vehicle, and Traffic Information for the Mississippi
Monitoring Sites 16-7
16-3 Average Meteorological Conditions near the Mississippi Monitoring Sites 16-9
16-4 Comparison of Measured Concentrations and EPA Screening Values for the
Mississippi Monitoring Sites 16-15
16-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Mississippi Monitoring Sites 16-17
16-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Mississippi Monitoring Sites 16-28
16-7 MRL Risk Screening Assessment Summary for the Mississippi Monitoring Sites .... 16-30
16-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Mississippi 16-32
16-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Mississippi 16-35
16-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Mississippi 16-36
17-1 Geographical Information for the Missouri Monitoring Site 17-4
17-2 Population, Motor Vehicle, and Traffic Information for the Missouri Monitoring
Site 17-5
17-3 Average Meteorological Conditions near the Missouri Monitoring Site 17-7
17-4 Comparison of Measured Concentrations and EPA Screening Values for the
Missouri Monitoring Site 17-11
xxxv
-------
LIST OF TABLES (Continued)
Page
17-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Missouri Monitoring Site 17-12
17-6 Pearson Correlations Between Selected Meteorological Parameters and Pollutants
of Interest for the Missouri Monitoring Site 17-20
17-7 MRL Risk Screening Assessment Summary for the Missouri Monitoring Site 17-21
17-8 Cancer and Noncancer Risk Summary for the Monitoring Site in Missouri 17-23
17-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Missouri 17-25
17-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Missouri 17-26
18-1 Geographical Information for the New Jersey Monitoring Sites 18-9
18-2 Population, Motor Vehicle, and Traffic Information for the New Jersey
Monitoring Sites 18-11
18-3 Average Meteorological Conditions near the New Jersey Monitoring Sites 18-14
18-4 Comparison of Measured Concentrations and EPA Screening Values for the New
Jersey Monitoring Sites 18-22
18-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the New Jersey Monitoring Sites 18-25
18-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the New Jersey Monitoring Sites 18-45
18-7 MRL Risk Screening Assessment Summary for the New Jersey Monitoring Sites.... 18-49
18-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in New Jersey 18-50
18-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in New
Jersey 18-55
18-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
New Jersey 18-57
19-1 Geographical Information for the New York Monitoring Sites 19-6
19-2 Population, Motor Vehicle, and Traffic Information for the New York Monitoring
Sites 19-7
19-3 Average Meteorological Conditions near the New York Monitoring Sites 19-10
19-4 Comparison of Measured Concentrations and EPA Screening Values for the New
York Monitoring Sites 19-15
19-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the New York Monitoring Sites 19-16
19-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the New York Monitoring Sites 19-18
19-7 Cancer and Noncancer Ri sk Summary for the Monitoring Sites in New York 19-20
xxxvi
-------
LIST OF TABLES (Continued)
Page
19-8 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in New
York 19-22
19-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
New York 19-23
20-1 Geographical Information for the Oklahoma Monitoring Sites 20-8
20-2 Population, Motor Vehicle, and Traffic Information for the Oklahoma Monitoring
Sites 20-11
20-3 Average Meteorological Conditions near the Oklahoma Monitoring Sites 20-13
20-4 Comparison of Measured Concentrations and EPA Screening Values for the
Oklahoma Monitoring Sites 20-21
20-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Oklahoma Monitoring Sites 20-24
20-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Oklahoma Monitoring Sites 20-27
20-7 MRL Risk Screening Assessment Summary for the Oklahoma Monitoring Sites 20-30
20-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Oklahoma 20-32
20-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Oklahoma 20-36
20-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Oklahoma 20-38
21-1 Geographical Information for the Puerto Rico Monitoring Sites 21-6
21-2 Population, Motor Vehicle, and Traffic Information for the Puerto Rico
Monitoring Sites 21-7
21-3 Average Meteorological Conditions near the Puerto Rico Monitoring Sites 21-9
21-4 Comparison of Measured Concentrations and EPA Screening Values for the
Puerto Rico Monitoring Sites 21-15
21-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Puerto Rico Monitoring Sites 21-17
21-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Puerto Rico Monitoring Sites 21-19
21-7 MRL Risk Screening Assessment Summary for the Puerto Rico Monitoring Sites ... 21-21
21-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Puerto Rico 21 -22
21-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Puerto Rico 21-25
21-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Puerto Rico 21-26
xxxvii
-------
LIST OF TABLES (Continued)
Page
22-1 Geographical Information for the Rhode Island Monitoring Site 22-4
22-2 Population, Motor Vehicle, and Traffic Information for the Rhode Island
Monitoring Site 22-5
22-3 Average Meteorological Conditions near the Rhode Island Monitoring Site 22-7
22-4 Comparison of Measured Concentrations and EPA Screening Values for the
Rhode Island Monitoring Site 22-10
22-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Rhode Island Monitoring Site 22-11
22-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Rhode Island Monitoring Site 22-13
22-7 Cancer and Noncancer Risk Summary for the Monitoring Site in Rhode Island 22-15
22-8 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Rhode Island 22-16
22-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Rhode Island 22-17
23-1 Geographical Information for the South Carolina Monitoring Site 23-4
23-2 Population, Motor Vehicle, and Traffic Information for the South Carolina
Monitoring Site 23-5
23-3 Average Meteorological Conditions near the South Carolina Monitoring Site 23-7
23-4 Comparison of Measured Concentrations and EPA Screening Values for the
South Carolina Monitoring Site 23-10
23-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the South Carolina Monitoring Site 23-11
23-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the South Carolina Monitoring Site 23-13
23-7 Cancer and Noncancer Risk Summary for the Monitoring Site in South Carolina 23-15
23-8 Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
South Carolina 23-16
23-9 Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
South Carolina 23-17
24-1 Geographical Information for the South Dakota Monitoring Sites 24-6
24-2 Population, Motor Vehicle, and Traffic Information for the South Dakota
Monitoring Sites 24-7
24-3 Average Meteorological Conditions near the South Dakota Monitoring Sites 24-10
24-4 Comparison of Measured Concentrations and EPA Screening Values for the
South Dakota Monitoring Sites 24-15
24-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the South Dakota Monitoring Sites 24-17
xxxviii
-------
LIST OF TABLES (Continued)
Page
24-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the South Dakota Monitoring Sites 24-31
24-7 MRL Risk Screening Assessment Summary for the South Dakota Monitoring
Sites 24-33
24-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in South Dakota 24-36
24-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
South Dakota 24-38
24-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
South Dakota 24-39
25-1 Geographical Information for the Tennessee Monitoring Sites 25-5
25-2 Population, Motor Vehicle, and Traffic Information for the Tennessee Monitoring
Sites 25-6
25-3 Average Meteorological Conditions near the Tennessee Monitoring Sites 25-8
25-4 Comparison of Measured Concentrations and EPA Screening Values for the
Tennessee Monitoring Sites 25-14
25-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Tennessee Monitoring Sites 25-15
25-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Tennessee Monitoring Sites 25-22
25-7 MRL Risk Screening Assessment Summary for the Tennessee Monitoring Sites 25-24
25-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Tennessee 25-25
25-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Tennessee 25-27
25-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Tennessee 25-28
26-1 Geographical Information for the Texas Monitoring Sites 26-6
26-2 Population, Motor Vehicle, and Traffic Information for the Texas Monitoring
Sites 26-7
26-3 Average Meteorological Conditions near the Texas Monitoring Sites 26-10
26-4 Comparison of Measured Concentrations and EPA Screening Values for the
Texas Monitoring Sites 26-15
26-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Texas Monitoring Sites 26-17
26-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Texas Monitoring Sites 26-19
26-7 MRL Risk Screening Assessment Summary for the Texas Monitoring Sites 26-21
26-8 Cancer and Noncancer Risk Summary for the Monitoring Sites in Texas 26-23
XXXIX
-------
LIST OF TABLES (Continued)
Page
26-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Sites in
Texas 26-25
26-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Sites in
Texas 26-26
27-1 Geographical Information for the Utah Monitoring Site 27-4
27-2 Population, Motor Vehicle, and Traffic Information for the Utah Monitoring Site 27-5
27-3 Average Meteorological Conditions near the Utah Monitoring Site 27-7
27-4 Comparison of Measured Concentrations and EPA Screening Values for the Utah
Monitoring Site 27-11
27-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Utah Monitoring Site 27-12
27-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Utah Monitoring Site 27-21
27-7 MRL Risk Screening Assessment Summary for the Utah Monitoring Site 27-23
27-8 Cancer and Noncancer Risk Summary for the Monitoring Site in Utah 27-24
27-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in Utah... 27-26
27-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Utah 27-27
28-1 Geographical Information for the Vermont Monitoring Site 28-4
28-2 Population, Motor Vehicle, and Traffic Information for the Vermont Monitoring
Site 28-5
28-3 Average Meteorological Conditions near the Vermont Monitoring Site 28-7
28-4 Comparison of Measured Concentrations and EPA Screening Values for the
Vermont Monitoring Site 28-10
28-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Vermont Monitoring Site 28-11
28-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Vermont Monitoring Site 28-13
28-7 Cancer and Noncancer Risk Summary for the Monitoring Site in Vermont 28-15
28-8 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Vermont 28-17
28-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Vermont 28-18
29-1 Geographical Information for the Washington Monitoring Site 29-4
xl
-------
LIST OF TABLES (Continued)
Page
29-2 Population, Motor Vehicle, and Traffic Information for the Washington
Monitoring Site 29-5
29-3 Average Meteorological Conditions near the Washington Monitoring Site 29-7
29-4 Comparison of Measured Concentrations and EPA Screening Values for the
Washington Monitoring Site 29-11
29-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Washington Monitoring Site 29-12
29-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Washington Monitoring Site 29-14
29-7 MRL Risk Screening Assessment Summary for the Washington Monitoring Site 29-16
29-8 Cancer and Noncancer Risk Summary for the Monitoring Site in Washington 29-17
29-9 Top 10 Emissions, Toxi city-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Washington 29-19
29-10 Top 10 Emissions, Toxi city-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Washington 29-20
30-1 Geographical Information for the Wisconsin Monitoring Site 30-4
30-2 Population, Motor Vehicle, and Traffic Information for the Wisconsin Monitoring
Site 30-5
30-3 Average Meteorological Conditions near the Wisconsin Monitoring Site 30-7
30-4 Comparison of Measured Concentrations and EPA Screening Values for the
Wisconsin Monitoring Site 30-10
30-5 Daily, Seasonal, and Annual Average Concentrations of the Pollutants of Interest
for the Wisconsin Monitoring Site 30-11
30-6 Pearson Correlations Between Selected Meteorological Parameters and the
Pollutants of Interest for the Wisconsin Monitoring Site 30-13
30-7 Cancer and Noncancer Risk Summary for the Monitoring Site in Wisconsin 30-15
30-8 Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk
Approximations for Pollutants with Cancer UREs for the Monitoring Site in
Wisconsin 30-16
30-9 Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk
Approximations for Pollutants with Noncancer RfCs for the Monitoring Site in
Wisconsin 30-17
31-1 Method Precision by Analytical Method 31-4
31-2 VOC Method Precision: 306 Duplicate and Collocated Samples 31-5
31-3 VOC Method Precision: 168 Collocated Samples 31-6
31-4 VOC Method Precision: 138 Duplicate Samples 31-8
31-5 VOC Method Precision: 12 Duplicate Samples for Bountiful, UT (BTUT) 31-10
31-6 VOC Method Precision: 48 Collocated Samples for Deer Park, TX (CAMS 35) 31-11
xli
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LIST OF TABLES (Continued)
Page
31-7 VOC Method Precision: 2 Collocated Samples for Karnack, TX (CAMS 85) 31-13
31-8 VOC Method Precision: 10 Collocated Samples for Dearborn, MI (DEMI) 31-14
31-9 VOC Method Precision: 12 Duplicate Samples for Grand Junction, CO (GPCO) 31-16
31-10 VOC Method Precision: 12 Collocated Samples for Northbrook, IL (NBIL) 31-18
31-11 VOC Method Precision: 6 Collocated Samples for Phoenix, AZ (PXSS) 31-19
31-12 VOC Method Precision: 12 Duplicate Samples for St. Louis, MO (S4MO) 31-21
31-13 VOC Method Precision: 14 Collocated Samples for Seattle, WA (SEWA) 31-22
31-14 VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated
Samples by Site 31-25
31-15 SNMOC Method Precision: 60 Duplicate and Collocated Samples 31-34
31-16 SNMOC Method Precision: 48 Duplicate Samples 31-36
31-17 SNMOC Method Precision: 12 Duplicate Samples for Bountiful, UT (BTUT) 31-38
31-18 SNMOC Method Precision: 12 Collocated Samples for Northbrook, IL (NBIL) 31-40
31-19 SNMOC Method Precision: Coefficient of Variation for all Duplicate and
Collocated Samples by Site 31-42
31-20 Carbonyl Method Precision: 352 Duplicate and Collocated Samples 31-44
31-21 Carbonyl Method Precision: 148 Collocated Samples 31-44
31-22 Carbonyl Method Precision: 204 Duplicate Samples 31-45
31-23 Carbonyl Method Precision: 12 Duplicate Samples for Bountiful, UT (BTUT) 31-46
31-24 Carbonyl Method Precision: 4 Collocated Samples for Dearborn, MI (DEMI) 31-46
31-25 Carbonyl Method Precision: 12 Duplicate Samples for Grand Junction, CO
(GPCO) 31-47
31-26 Carbonyl Method Precision: 12 Collocated Samples for Northbrook, IL (NBIL) 31-47
31-27 Carbonyl Method Precision: 6 Collocated Samples for Phoenix, AZ (PXSS) 31-48
31-28 Carbonyl Method Precision: 12 Duplicate Samples for St. Louis, MO (S4MO) 31-49
31-29 Carbonyl Method Precision: 14 Collocated Samples for Seattle, WA (SEWA) 31-49
31-30 Carbonyl Method Precision: 12 Duplicate Samples for Pinellas Park, FL (SKFL) .... 31-50
31-31 Carbonyl Method Precision: 14 Duplicate Samples for Plant City, FL (SYFL) 31-50
31-32 Carbonyl Method Precision: Coefficient of Variation for all Duplicate and
Collocated Samples by Site 31-51
31-33 Metal Method Precision: 198 Collocated Samples 31-54
31-34 Metal Method Precision: 60 Collocated Samples at Boston, MA (BOMA) 31-54
31-35 Metal Method Precision: 6 Collocated Samples at Bountiful, UT (BTUT) 31-55
31-36 Metal Method Precision: 22 Collocated Samples at St. Louis, MO (S4MO) 31-55
31-37 Metal Method Precision: 2 Collocated Samples at Seattle, WA (SEWA) 31-56
31-38 Metal Method Precision: Coefficient of Variation for all Collocated Samples by
Site 31-57
31-39 Hexavalent Chromium Method Precision: Collocated Samples 31-57
31-40 SVOC Method Precision: 50 Collocated Samples 31-58
31-41 SVOC Method Precision: 42 Collocated Samples atRubidoux, CA (RUCA) 31-59
31-42 SVOC Method Precision: 8 Collocated Samples atDecatur, GA (SDGA) 31-60
31-43 VOC Analytical Precision: 596 Replicate Analyses for all Duplicate and
Collocated Samples 31-62
31-44 VOC Analytical Precision: 316 Replicate Analyses for all Collocated Samples 31-63
xlii
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LIST OF TABLES (Continued)
Page
31-45 VOC Analytical Precision: 280 Replicate Analyses for all Duplicate Samples 31-65
31-46 VOC Analytical Precision: 24 Replicate Analyses for Duplicate Samples for
Bountiful, UT (BTUT) 31-67
31-47 VOC Analytical Precision: 80 Replicate Analyses for Collocated Samples for
Deer Park, TX (CAMS 3 5) 31-68
31-48 VOC Analytical Precision: 4 Replicate Analyses for Collocated Samples for
Karnack, TX (CAMS 85) 31-70
31-49 VOC Analytical Precision: 24 Replicate Analyses for Collocated Samples for
Dearborn, MI (DEMI) 31-71
31-50 VOC Analytical Precision: 24 Replicate Analyses for Duplicate Samples for
Grand Junction, CO (GPCO) 31-73
31-51 VOC Analytical Precision: 18 Replicate Analyses for Collocated Samples for
Northbrook, IL (NBIL) 31-74
31-52 VOC Analytical Precision: 12 Replicate Analyses for Collocated Samples for
Phoenix, AZ (PXSS) 31-76
31-53 VOC Analytical Precision: 22 Replicate Analyses for Duplicate Samples for St.
Louis, MO (S4MO) 31-77
31-54 VOC Analytical Precision: 28 Replicate Analyses for Collocated Samples for
Seattle, WA (SEWA) 31-79
31-55 VOC Analytical Precision: Coefficient of Variation for all Replicate Analyses by
Site 31-81
31-56 SNMOC Analytical Precision: 112 Replicate Analyses for all Duplicate and
Collocated Samples 31-89
31-57 SNMOC Analytical Precision: 96 Replicate Analyses for all Duplicate Samples 31-91
31-58 SNMOC Analytical Precision: 24 Replicate Analyses for Duplicate Samples for
Bountiful, UT (BTUT) 31-93
31-59 SNMOC Analytical Precision: 16 Replicate Analyses for Collocated Samples for
Northbrook, IL (NBIL) 31-95
31-60 SNMOC Analytical Precision: Coefficient of Variation for all Replicate Analyses
by Site 31-97
31-61 Carbonyl Analytical Precision: 818 Replicate Analyses for all Duplicate and
Collocated Samples 31-99
31-62 Carbonyl Analytical Precision: 408 Replicate Analyses for all Collocated
Samples 31-100
31-63 Carbonyl Analytical Precision: 410 Replicate Analyses for all Duplicate Samples . 31-100
31-64 Carbonyl Analytical Precision: 24 Replicate Analyses for Duplicate Samples for
Bountiful, UT (BTUT) 31-101
31-65 Carbonyl Analytical Precision: 120 Replicate Analyses for Collocated Samples
for Dearborn, MI (DEMI) 31-102
31-66 Carbonyl Analytical Precision: 24 Replicate Analyses for Duplicate Samples for
Grand Junction, CO (GPCO) 31-102
31-67 Carbonyl Analytical Precision: 24 Replicate Analyses for Collocated Samples for
Northbrook, IL (NBIL) 31-103
xliii
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LIST OF TABLES (Continued)
Page
31-68 Carbonyl Analytical Precision: 12 Replicate Analyses for Collocated Samples for
Phoenix, AZ (PXSS) 31-103
31-69 Carbonyl Analytical Precision: 24 Replicate Analyses for Duplicate Samples for
St. Louis, MO (S4MO) 31-104
31-70 Carbonyl Analytical Precision: 28 Replicate Analyses for Collocated Samples for
Seattle, WA (SEWA) 31-104
31-71 Carbonyl Analytical Precision: 28 Replicate Analyses for Duplicate Samples for
Pinellas Park, FL (SKFL) 31-105
31-72 Carbonyl Analytical Precision: 28 Replicate Analyses for Duplicate Samples for
Plant City, FL (SYFL) 31-105
31-73 Carbonyl Analytical Precision: Coefficient of Variation for all Replicate Analyses
by Site 31-106
31-74 Metal Analytical Precision: 384 Collocated Samples 31-109
31-75 Metal Analytical Precision: 112 Collocated Samples at Boston, MA (BOMA) 31-109
31-76 Metal Analytical Precision: 12 Collocated Samples at Bountiful, UT (BTUT) 31-110
31-77 Metal Analytical Precision: 46 Collocated Samples at St. Louis, MO (S4MO) 31-111
31-78 Metal Analytical Precision: 4 Collocated Samples at Seattle, WA (SEWA) 31-111
31-79 Metals Analytical Precision: Coefficient of Variation for all Replicate Analyses
by Site 31-112
31-80 Hexavalent Chromium Analytical Precision: Replicate Analyses for Collocated
Samples 31-113
31-81 SVOC Analytical Precision: 98 Collocated Samples 31-114
31-82 SVOC Analytical Precision: 90 Collocated Samples at Rubidoux, CA (RUCA) 31-114
31-83 SVOC Analytical Precision: 8 Collocated Samples atDecatur, GA (SDGA) 31-115
31 -84 Carbonyl NATTS PT Audit Samples - Percent Difference from True Value 31-116
31-85 Metals NATTS PT Audit Samples - Percent Difference from True Value 31-117
31-86 VOC NATTS PT Audit Samples - Percent Difference from True Value 31-117
xliv
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LIST OF ACRONYMS
AADT Annual average daily traffic
AGL Above ground level
AIRS Aerometric Information and Retrieval System
AQS Air Quality Subsystem (of the Aerometric Information and Retrieval System)
ATSDR Agency for Toxic Substances and Disease Registry
BTEX benzene, toluene, ethylbenzene, and xylenes (o-, w-, and/?-xylene)
CALEPA California EPA
CBS A Core-based statistical area(s)
CFR Code of Federal Regulations
CV coeffi ci ent of vari ati on
DNPH 2,4-dinitrophenylhydrazine
DQO Data Quality Objective(s)
EPA U.S. Environmental Protection Agency
ERG Eastern Research Group
FHWA Federal highway administration
GC gas chromatography
GC/MS-FID gas chromatography/mass spectrometry and flame ionization detection
GHG Greenhouse gas
GIS Geographic Information Systems
GWP Global warming potential
HAP hazardous air pollutant
HPLC high-performance liquid chromatography
HQ Hazard Quotient
HYSPLIT Hybrid Single-Particle Lagrangian Integrated Trajectory
1C Ion Chromatography
L liter
LOAEL Lowest observed adverse effect level
m3 Cubic meter
MDL method detection limit
MRL Minimal risk level
MSA metropolitan statistical area(s)
MTBE methyl tert-butyl ether
NATA National Air Toxics Assessment
NATTS National Air Toxics Trends Station
NA not applicable
NCore National Core Monitoring Program
ND Non-detect
NEI National Emissions Inventory
ng/m3 Nanograms per cubic meter
xlv
-------
LIST OF ACRONYMS (Continued)
NOAA National Oceanic and Atmospheric Administration
NOx Oxides of Nitrogen
NWS National Weather Station
PAMS Photochemical Assessment Monitoring Strategy
ppbC parts per billion carbon
ppbv parts per billion (by volume)
ppm parts per million
pg/m3 Picograms per cubic meter
PM particulate matter
PUF Polyurethane foam
QAPP Quality Assurance Project Plan
REL Reference exposure limit
RfC Reference Concentration
RFG Reformulated gasoline
RPD relative percent difference
SIP State Implementation Plan(s)
SNMOC Speciated Nonmethane Organic Compound
SVOC Semivolatile Organic Compounds
TAD Technical Assistance Document
TNMOC Total Nonmethane Organic Compound(s)
tpy tons per year
TSP Total Suspended Particulate
UATMP Urban Air Toxics Monitoring Program
|ig/m3 Micrograms per cubic meter
URE Unit Risk Estimate
VMT Vehicle miles traveled
VOC Volatile Organic Compound(s)
WBAN Weather Bureau/Army/Navy ID
xlvi
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Abstract
This report presents the results and conclusions from the ambient air monitoring conducted
as part of the 2007 Urban Air Toxics Monitoring Program (UATMP), a program designed to
characterize the magnitude and composition of potentially toxic air pollution in, or near, urban
locations; and the National Air Toxics Trends Stations (NATTS) network, a program designed to
generate long-term ambient air toxics concentration data in order to evaluate trends. The 2007
NATTS/UATMP programs consisted of 50 monitoring sites that collected 24-hour air samples
including:
• 27 sites that sampled for 60 volatile organic compounds (VOC),
• 33 sites that sampled for 15 carbonyl compounds,
• 5 sites that sampled for 80 speciated nonmethane organic compounds (SNMOC),
• 5 sites that sampled for 19 semivolatile compounds (SVOC),
• 11 sites that sampled for 11 metals, and
• 19 sites that sampled for hexavalent chromium.
Overall, over 190,000 ambient air concentrations were measured during the 2007
NATTS/UATMP. This report uses various graphical, numerical, and statistical analyses to put
the vast amount of ambient air monitoring data collected into perspective. Not surprisingly, the
ambient air concentrations measured during the program varied significantly from city to city and
from season to season.
The ambient air monitoring data collected during the 2007 NATTS/UATMP serve a wide
range of purposes. Not only do these data characterize the nature and extent of urban air
pollution close to the 50 monitoring sites participating in this study, but they also indicate some
trends and patterns that may be common to all urban environments. Therefore, this report
presents some results that are specific to particular monitoring locations and presents other results
that are apparently common to urban environments. The results should ultimately provide
additional insight into the complex nature of urban air pollution. The final data are also included
in the appendices to this report.
xlvii
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1.0 Introduction
Air pollution in urban locations incorporates many components that originate from a
wide range of stationary, mobile, and natural emissions sources. Because some of these
components include toxic compounds known or suspected to have the potential for negative
human health impacts, the U.S. Environmental Protection Agency (EPA) encourages state, local,
and tribal agencies to understand and appreciate the nature and extent of toxic air pollution in
urban locations. To achieve this goal, EPA sponsors the National Monitoring Programs.
Components of the National Monitoring Programs include the Photochemical Assessment
Monitoring Strategy (PAMS); Urban Air Toxics Monitoring Program (UATMP); National Air
Toxics Trends Stations (NATTS) network; and monitoring for specific pollutants such as
Hazardous Air Pollutants (HAP) and Non-methane Organic Compounds (NMOC). This report
focuses on the UATMP and NATTS programs. The purpose of the UATMP is to characterize
the composition and magnitude of urban air pollution through extensive ambient air monitoring.
The ultimate goal of the NATTS network is to obtain a statistically significant quantity of
high-quality representative air toxics measurements such that long-term trends can be identified.
1.1 Background
EPA began the NMOC program in 1984. Monitoring for selected compounds was
performed during the morning hours of the summer ozone season. NMOC data were to be used
to develop ozone control strategies. The UATMP was initiated by EPA in 1987 as an extension
of the existing NMOC program to meet the increasing need for information on air toxics. The
program was intended to allow participating agencies to screen air samples for concentrations of
air toxics that could potentially result in adverse human health effects (EPA, 2003). The
program has allowed the identification of compounds that are prevalent in ambient air and the
identification of emission sources likely contributing to existing concentration levels. Over the
years, the program has grown in both participation levels and pollutants targeted (EPA, 2007a).
The NATTS network was created to generate long-term ambient air toxics concentration
data at specific fixed sites across the country. The NATTS Pilot program was developed and
implemented during 2001 and 2002, leading to the development and initial implementation of
the NATTS network during 2003 and 2004. The goal of the program was to estimate the
1-1
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concentrations of air toxics on a national level at fixed sites that remain active over an extended
period of time. The generation of large quantities of high-quality data over an extended period
may allow concentration trends (i.e., any substantial increase or decrease over a period of time)
to be identified. The data generated are also used for validating modeling results and emission
inventories, assessing current regulatory benchmarks, and reducing the risk of developing
cancerous and noncancerous health effects. The site locations were based on results from
preliminary air toxics pilot programs such as the 1996 National Air Toxics Assessment (NATA),
which used air toxics emissions data to model ambient monitoring concentrations across the
nation. Both urban and rural locations were chosen as NATTS monitoring sites. Urban areas
were chosen to measure population exposure, while rural areas were chosen to determine
background levels of air pollution (EPA, 2007a). Twenty-five NATTS sites are strategically
placed across the country.
Many environmental and health agencies have participated in the programs to assess the
sources, the effects, and the changes in air pollution within their jurisdictions. In past reports,
measurements from both NATTS and UATMP monitoring sites have been presented together
and referred to as "UATMP sites." Beginning with this report, a distinction is made between the
two programs due to the increasing number of NATTS sites covered under the National
Monitoring Programs. As such, it is appropriate to describe both programs; to distinguish
between the purposes and scopes; and to integrate the data, which will allow the program's
objectives and goals to complement each other.
1.2 The Report
This report summarizes and interprets the 2007 NATTS and UATMP monitoring efforts,
which includes up to 12 months of l-in-6 or l-in-12 day measurements of ambient air samples at
50 monitoring sites in or near 44 urban/rural locations in 26 states, including 27 metropolitan
statistical areas (MSA). Much of the data analysis and interpretation in this report focuses on
pollutant-specific risk potential.
The contents of this report provide both a qualitative overview of air toxics pollution at
selected urban and rural locations and a quantitative data analysis of the factors that appear to
1-2
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affect urban and rural air quality most significantly. This report also focuses on data
characterization at each of the 50 different air sampling locations, a site-specific approach that
allows for much more detailed evaluation of the factors (e.g., stationary sources, mobile sources,
natural sources, meteorological influences) that affect air quality differently from one location to
the next.
The contents of this report offer participating agencies useful insights into important air
quality issues. For example, participating agencies can use trends and patterns in the NATTS
and UATMP monitoring data to determine whether levels of air pollution present public health
concerns, to identify which emission sources contribute most to air pollution, or to forecast
whether proposed pollution control initiatives might significantly improve air quality. NATTS
and UATMP monitoring data may also be compared to modeling results, such as from EPA's
NATA.
Policy-relevant questions that the NATTS and UATMP data may help answer include the
following:
• Which anthropogenic sources substantially affect air quality?
• Have pollutant concentrations decreased as a result of regulations?
• Which pollutants contribute the greatest health risk on a short-term, intermediate-
term, and long-term basis?
The data analyses contained in this report are applied to every participating NATTS or
UATMP monitoring site, depending upon pollutants sampled. Although many types of analyses
are presented, state and local environmental agencies are encouraged to perform additional
evaluations of the monitoring data so that the many factors that affect their specific ambient air
quality can be understood fully.
To facilitate examination of the 2007 NATTS and UATMP monitoring data, the
complete set of measured concentrations is presented in the appendices of this report. In
addition, these data are publicly available in electronic format from the Air Quality Subsystem
1-3
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(AQS) of EPA=s Aerometric Information Retrieval System (AIRS) at
http ://www. epa. gov/ttn/airs/airsaq s/.
The report is organized into 33 sections and 16 appendices. While each state section is
designed to be a stand-alone section to allow those interested in a particular site or state to
understand the data analyses without having to read the entire report, it is recommended that
Sections 1 through 4 (Introduction, Monitoring Network Overview, Methods, and Results) and
Sections 31 and 32 (Quality Assurance and Conclusions and Recommendations) be read as
complements to the individual state sections. Table 1-1 highlights the contents of each section.
Table 1-1. Organization of the 2007 National Monitoring Programs (NATTS and UATMP)
Report
Report
Section
1
2
3
4
5
6
Section Title
Introduction
The 2007 NATTS/UATMP
Network
Summary of the 2007
NATTS/UATMP Data
Treatments/Methods
Summary of the 2007
NATTS/UATMP Results
Sites in Arizona
Sites in California
Overview of Contents
This section serves as an introduction to the
background and scope of the National Monitoring
Programs (specifically, the NATTS and UATMP).
This section provides information on the 2007 NATTS
and UATMP programs and network:
$ Monitoring locations
$ Pollutants selected for monitoring
$ Sampling and analytical methods
$ Sampling schedules
$ Completeness of the air monitoring programs.
This section presents and discusses the data treatments
used on the 2007 NATTS/UATMP data to determine
significant trends and relationships in the data,
characterize data based on how ambient air
concentrations varied with monitoring location and
with time, present an interpretation of the significance
of the observed spatial and temporal variations, and
evaluate risk.
This section presents and discusses the results of the
data treatments from the 2007 NATTS/UATMP data.
Monitoring results for the sites in the Phoenix-Mesa-
Scottsdale, AZ MSA (PXSS and SPAZ)
Monitoring results for the sites in the Los Angeles-
Riverside-Orange County, CA CMSA (CELA and
RUCA)
1-4
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Table 1-1. Organization of the 2007 National Monitoring Programs (NATTS and UATMP)
Report (Continued)
Report
Section
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
Section Title
Site in Colorado
Site in Washington, B.C.
Sites in Florida
Site in Georgia
Sites in Illinois
Sites in Indiana
Site in Kentucky
Site in Massachusetts
Sites in Michigan
Sites in Mississippi
Site in Missouri
Sites in New Jersey
Sites in New York
Sites in Oklahoma
Sites in Puerto Rico
Site in Rhode Island
Overview of Contents
Monitoring results for the site in the Grand Junction,
CO MSA (GPCO)
Monitoring results for the site in the Washington, DC-
VA-MD-WV MSA (WADC)
Monitoring results for the sites in the Orlando-
Kissimmee, FL MSA (ORFL), Miami-Ft. Lauderdale-
Pompano Beach, FL MSA (FLFL), and Tampa-St.
Petersburg-Clearwater, FL MSA (AZFL, GAFL,
SKFL, and SYFL)
Monitoring results for the site in the Atlanta-Sandy
Springs-Marietta, GA MSA (SDGA)
Monitoring results for the sites in the Chicago-
Naperville-Joliet, IL-IN-WI MSA (NBIL and SPIL)
Monitoring results for the sites in the Chicago-
Naperville-Joliet, IL-IN-WI MSA (INDEM), and
Indianapolis-Carmel, IN MSA (IDIN, ININ, and
WPIN)
Monitoring results for the site in Hazard, KY (HAKY)
Monitoring results for the site in the Boston-
Cambridge-Quincy, MA-NH MSA (BOMA)
Monitoring results for the sites in the Detroit-Warren-
Livonia, MI MSA (DEMI) and Sault Sainte Marie, MI
(ITCMI)
Monitoring results for the sites in Tupelo, MS (TUMS)
and the Gulfport-Biloxi, MS MSA (GPMS)
Monitoring results for the site in the St. Louis, MO-IL
MSA (S4MO)
Monitoring results for the sites in the New York-
Northern New Jersey-Long Island, NY-NJ-PA MSA
(CHNJ, ELNJ, and NBNJ) and Philadelphia-Camden-
Wilmington, PA-NJ-DE-MD MSA (CANJ)
Monitoring results for the sites in the New York-
Northern New Jersey-Long Island, NY-NJ-CT-PA
CMSA (BXNY) and Rochester, NY MSA (ROCH)
Monitoring results for the sites in the Tulsa, OK MSA
(TOOK, TSOK, and TUOK) and Pryor, OK (CNEP)
Monitoring results for the sites in the San Juan-
Caguas-Guaynabo, PR MSA (BAPR and SJPR)
Monitoring results for the site in the Providence-New
Bedford-Fall River, RI-MA MSA (PRRI)
1-5
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Table 1-1. Organization of the 2007 National Monitoring Programs (NATTS and UATMP)
Report (Continued)
Report
Section
23
24
25
26
27
28
29
30
31
32
33
Section Title
Site in South Carolina
Sites in South Dakota
Sites in Tennessee
Sites in Texas
Site in Utah
Site in Vermont
Site in Washington
Site in Wisconsin
Data Quality
Summary of Results and
Recommendations
References
Overview of Contents
Monitoring results for the site in Chesterfield, SC
(CHSC)
Monitoring results for the sites in Custer, SD (CUSD)
and the Sioux Falls, SD MSA (SFSD)
Monitoring results for the sites in the Knoxville, TN
MSA (LDTN and MSTN)
Monitoring results for the sites in the Houston-
Galveston-Brazoria, TX CMSA (CAMS 35) and
Longview-Marshall, TX MSA (CAMS 85)
Monitoring results for the site in the Ogden-Clearfield,
UT MSA (BTUT)
Monitoring results for the site in the Burlington-South
Burlington, VT MSA (UNVT)
Monitoring results for the site in the Seattle-Tacoma-
Bellevue, WA MSA (SEWA)
Monitoring results for the site in Mayville, WI
(MVWI)
This section defines and discusses the concepts of
precision and accuracy. Based on quantitative and
qualitative analyses, this section comments on the
precision and accuracy of the 2007 NATTS/UATMP
ambient air monitoring data.
This section summarizes the most significant findings
of the report and makes several recommendations for
future projects that involve ambient air monitoring in
urban locations.
This section lists the references cited throughout the
report.
1-6
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2.0 The 2007 NATTS/UATMP Network
Agencies operating NATTS or UATMP sites that choose to participate in the National
Monitoring Programs have their samples analyzed by the Eastern Research Group, Inc. (ERG)
laboratory in Morrisville, NC. Data from 50 monitoring sites that collected 24-hour integrated
ambient air samples for up to 12 months, at l-in-6 or l-in-12 day sampling intervals are included
in this report. Samples were analyzed for concentrations of selected hydrocarbons, halogenated
hydrocarbons, and polar compounds from canister samples (Speciated Nonmethane Organic
Compounds (SNMOC) and TO-15), carbonyl compounds from sorbent cartridge samples
(TO-11 A), semivolatile organic compounds (SVOC) from polyurethane foam (PUF) and
XAD-2® resin samples (TO-13), hexavalent chromium from sodium bicarbonate coated filters
(EPA-approved method), and trace metals from filters (IO-3.5). Section 2.5 provides further
details on each of the sampling methodologies used to collect and analyze samples. Note that
agencies operating NATTS sites are not required to have their samples analyzed by ERG or may
not have samples for all methods analyzed by ERG, as they may have their own laboratories or
use other contractors. In these cases, the data are generated by sources outside ERG and are
therefore not included in this report.
The following sections review the monitoring locations, pollutants selected for
monitoring, collection schedules, sampling and analytical methods, and completeness of the
2007 NATTS/UATMP dataset.
2.1 Monitoring Locations
For the NATTS Program, monitor siting was based on the need to assess population
exposure and background-level concentrations. For the UATMP, representatives from the state,
local, and tribal agencies that voluntarily participate in the programs and contribute to the overall
monitoring costs select the monitoring locations based on specific siting criteria and study needs.
For both programs, some monitors were placed in urban areas near the centers of heavily
populated cities (e.g., Chicago, IL and Phoenix, AZ), while others were placed in moderately
populated rural areas (e.g., Custer, SD and Chesterfield, SC). Figure 2-1 shows the locations of
the 50 monitoring sites participating in the 2007 programs, which encompass 44 different urban
and rural areas. Outlined in Figure 2-1 are the associated core-based statistical areas (CBSA), as
2-1
-------
Figure 2-1. Locations of the 2007 NATTS and UATMP Monitoring Sites
^Seattle, V.'A
to
Boston, MA
W*
Providence, R<
lew York, NY
llzabwth, NJ
New Brunswick, NJ
Washington, DC
) *"' X- :\.NWirtter Park, FL
Plant Ctty,
Plnrtlas Park, FL-
Tampa, f\/
, P«(«sbyrg, FLf \ d Davie, FL
Legend
* Monitoring site
MetropQlitan'Mkropolitan Statistical Area
San Juan, PR
BarccloneUv.
-------
designated by the U.S. Census Bureau, where each site is located. A CBSA refers to either a
micropolitan or metropolitan statistical area (MSA) (U.S. Census Bureau, 2007).
As Figure 2-1 shows, the 2007 UATMP and NATTS monitoring sites are widely
distributed across the country. Detailed information on the surroundings near the monitoring
sites is contained in Table 2-1 and Appendix A. Monitoring sites that are designated as part the
NATTS network are indicated by bold italic type in Table 2-1 and subsequent tables throughout
this report in order to distinguish between the two programs' sites. This table shows that the
types of locations of the monitoring sites vary significantly, based on elevation, population, land
use, climatology, and topography. A more detailed look at each monitoring site's surroundings
is provided in the individual state sections. The monitoring data from these 50 sites may indicate
certain air quality trends that are common to all urban environments, but may also show distinct
geographic trends. The data analyses in this report differentiate the trends that appear to be site-
specific from those that appear to be common to most urban environments.
For record keeping and reporting purposes, each site was assigned:
• A unique four- or five-letter site code B used to track samples from the monitoring
sites to the ERG laboratory; and
• A unique nine-digit AQS site code B used to index monitoring results in the AQS
database.
This report cites the four- or five-letter site code when presenting selected monitoring
results. For reference, each site's AQS site code is provided in Table 2-1.
The proximity of the monitoring locations to different emissions sources, especially
industrial facilities and heavily traveled roadways, often explains the observed spatial variations
in ambient air quality. To provide a first approximation of the contributions of stationary and
mobile source emissions on ambient air quality at each site, Table 2-1 lists the stationary source
HAP emissions in the monitoring site's residing county, according to the 2002 National
Emissions Inventory (NEI). In addition, the number of people living within 10 miles of each
monitoring site location is also provided. Lastly, Table 2-1 contains the county-level number of
motor vehicles owned in each site's respective county, based on registration.
2-3
-------
Table 2-1. Descriptions of the 2007 NATTS and UATMP Monitoring Sites
Site
Code
AZFL
BAPR
BOMA
BTUT
BXNY
CAMS
35
CAMS
85
CANJ
CELA
CHNJ
CHSC
CNEP
CUSD
AQS
Code
12-103-0018
72-017-0003
25-025-0042
49-011-0004
36-005-0110
48-201-1039
48-203-0002
34-007-0003
06-037-1103
34-027-3001
45-025-0001
40-097-9014
46-033-0003
Location
Azalea Park, St.
Petersburg, FL
Barceloneta, PR
Boston, MA
Bountiful, UT
Bronx, NY
Deer Park, TX
Karnack, TX
Camden, NJ
Los Angeles, CA
Chester, NJ
Chesterfield, SC
Pryor, OK
Custer, SD
Land Use
Residential
Residential
Commercial
Residential
Residential
Residential
Agricultural
Residential
Residential
Agricultural
Forest
Agricultural
Residential
Location
Setting
Suburban
Rural
Urban/City
Center
Suburban
Urban/City
Center
Suburban
Rural
Suburban
Urban/City
Center
Rural
Rural
Rural
Suburban
Estimated
Daily Traffic
(# vehicles)
37,000
48,400
23,800
17,310
101,475
31,130
2,380
4,633
238,000
18,360
650
5
2,500
Traffic
Year
Estimate
2006
2004
2005
2006
2002
2001
2002
2005/2007
2005
2005
2006
2003
2006
Population
Residing Within
10 Miles of the
Monitoring Site"
917,437
23,038b
713,049
288,146
1,373,659
3,935,855
63,504
513,769
9,878,554
488,475
42,761
39,627
7,818
County-level
Vehicle
Registration
1,548,528
13,912
467,969
230,868
243,523
3,192,222
67,719
352,413
7,514,916
335,063
42,726
29,398
15,345
County-level
Stationary
Source HAP
Emissions in
the 2002 NEIC
(tpy)
2,825.17
405.85
1,636.84
937.91
4,009.77
18,845.45
1,266.61
1,396.95
36,636.15
1,263.08
488.26
343.09
22.83
to
BOLD = EPA-designated NATTS site.
a Reference: http://zipfind.net
b County population used as surrogate.
c Reference: EPA, 2006a.
dGPCO's hexavalent chromium monitor is at a separate, but adjacent location; as such, this site has two AQS codes.
-------
Table 2-1. Descriptions of the 2007 NATTS and UATMP Monitoring Sites (Continued)
Site
Code
DEMI
ELNJ
FLFL
GAFL
GPCOd
GPMS
HAKY
IDIN
INDEM
ININ
ITCMI
LDTN
MSTN
AQS
Code
26-163-0033
34-039-0004
12-011-1002
12-057-1065
08-077-00177
08-077-0018
28-047-0008
21-193-0003
18-097-0085
18-089-0022
18-097-0057
26-033-0901
47-105-0108
47-105-0109
Location
Dearborn, MI
Elizabeth, NJ
Davie, FL
Tampa, FL
Grand Junction, CO
Gulfport, MS
Hazard, KY
Stout Field,
Indianapolis, IN
Gary, IN
South Harding,
Indianapolis, IN
Sault Sainte Marie, MI
Loudon, TN
Loudon, TN
Land Use
Industrial
Industrial
Commercial
Commercial
Commercial
Commercial
Residential
Military
Reservation
Industrial
Residential
Residential
Residential
Residential
Location
Setting
Suburban
Suburban
Suburban
Suburban
Urban/City
Center
Rural
Suburban
Urban/City
Center
Urban/City
Center
Urban/City
Center
Rural
Suburban
Suburban
Estimated
Daily Traffic
(# vehicles)
20,900
200,000
14,000
41,000
12,300
27,000
21,537
77,250
40,710
97,780
5,200
12,945
7,287
Traffic
Year
Estimate
2006
Unknown
2006
2006
2006
2006
2005
2002
2002
2002
2006
2006
2006
Population
Residing Within
10 Miles of the
Monitoring Site"
1,985,101
524,658
1,759,591
1,174,727
139,082
176,105
29,213
876,804
492,104
876,804
38,922
45,448
45,448
County-level
Vehicle
Registration
1,400,461
359,882
1,541,754
1,203,440
163,539
170,041
47,549
897,388
453,146
897,388
36,768
50,519
50,519
County-level
Stationary
Source HAP
Emissions in
the 2002 NEIC
(tpy)
9,313.21
2,067.39
11,7741.91
7,251.75
553.15
3,272.37
115.24
4,328.71
3,300.47
4,328.71
193.07
1,550.05
1,550.05
to
BOLD = EPA-designated NATTS site.
a Reference: http://zipfind.net
b County population used as surrogate.
c Reference: EPA, 2006a.
dGPCO's hexavalent chromium monitor is at a separate, but adjacent location; as such, this site has two AQS codes.
-------
Table 2-1. Descriptions of the 2007 NATTS and UATMP Monitoring Sites (Continued)
Site
Code
MVWI
NBIL
NBNJ
ORFL
PRRI
PXSS
ROCH
RUCA
S4MO
SDGA
SEWA
SFSD
SJPR
AQS
Code
55-027-0007
17-031-4201
34-023-0006
12-095-2002
44-007-0022
04-013-9997
36-055-1007
06-065-8001
29-510-0085
13-089-0002
53-033-0080
46-099-0007
72-021-0006
Location
Mayville, WI
Northbrook, IL
New Brunswick, NJ
Winter Park, FL
Providence, RI
Phoenix, AZ
Rochester, NY
Rubidoux, CA
St. Louis, MO
Decatur, GA
Seattle, WA
Sioux Falls, SD
San Juan, PR
Land Use
Agricultural
Residential
Agricultural
Commercial
Residential
Residential
Residential
Residential
Residential
Residential
Industrial
Residential
Industrial
Location
Setting
Rural
Suburban
Rural
Urban/City
Center
Urban/City
Center
Urban/City
Center
Urban/City
Center
Suburban
Urban/City
Center
Suburban
Suburban
Urban/City
Center
Suburban
Estimated
Daily Traffic
(# vehicles)
3,500
35,700
63,326
35,500
212,100
206,000
111,600
17,468
84,821
9,100
232,000
4,265
139,563
Traffic
Year
Estimate
2004
2006
2005
2006
2006
2006
2003
2004
2006
2006
2006
2005
2003
Population
Residing Within
10 Miles of the
Monitoring Site"
87,786
5,285,107
788,629
1,066,113
629,435
3,880,181
729,681
2,073,571
1,345,877
737,093
1,859,284
175,272
220,574b
County-level
Vehicle
Registration
92,255
2,104,894
540,949
1,048,589
142,334
3,793,646
552,452
1,344,232
1,136,095
471,264
1,766,228
212,906
145,642
County-level
Stationary
Source HAP
Emissions in
the 2002 NEIC
(tpy)
556.02
23,488.15
2,627.52
4,820.66
1,271.23
9,644.29
6,303.94
5,367.35
2,243.81
12,101.27
5,291.45
536.15
226.52
to
BOLD = EPA-designated NATTS site.
a Reference: http://zipfind.net
b County population used as surrogate.
c Reference: EPA, 2006a.
dGPCO's hexavalent chromium monitor is at a separate, but adjacent location; as such, this site has two AQS codes.
-------
Table 2-1. Descriptions of the 2007 NATTS and UATMP Monitoring Sites (Continued)
Site
Code
SKFL
SPAZ
SPIL
SYFL
TOOK
TSOK
TUMS
TUOK
UNVT
WADC
WPIN
AQS
Code
12-103-0026
04-013-4003
17-031-3103
12-057-3002
40-143-0235
40-143-0172
28-081-0005
40-143-0191
50-007-0007
11-001-0043
18-097-0078
Location
Pinellas Park, FL
Phoenix, AZ
Schiller Park, IL
Plant City, FL
Site #1, Tulsa, OK
Site #2, Tulsa, OK
Tupelo, MS
Site #3, Tulsa, OK
Underbill, VT
Washington, D.C.
Washington Park,
Indianapolis, IN
Land Use
Residential
Residential
Mobile
Residential
Industrial
Residential
Commercial
Residential
Forest
Commercial
Residential
Location
Setting
Suburban
Urban/City
Center
Suburban
Rural
Urban/City
Center
Suburban
Suburban
Urban/City
Center
Rural
Urban/City
Center
Suburban
Estimated
Daily Traffic
(# vehicles)
48,000
113,000
202,900
30,500
67,092
33,800
12,000
45,300
1,200
36,800
155,900
Traffic
Year
Estimate
2006
2006
2006
2006
2006
2006
2006
2006
2005
2002
2002
Population
Residing Within
10 Miles of the
Monitoring Site"
917,437
3,880,181
5,285,107
1,174,727
585,068
585,068
80,349
585,068
151,826
588,292
876,804
County-level
Vehicle
Registration
1,548,528
3,793,646
2,104,894
1,203,440
506,011
506,011
71,812
506,011
143,618
219,105
897,388
County-level
Stationary
Source HAP
Emissions in
the 2002 NEIC
(tpy)
2,825.17
9,644.29
23,488.15
7,251.75
1,877.66
1,877.66
1,016.31
1,877.66
589.60
733.24
4,328.71
to
BOLD = EPA-designated NATTS site.
a Reference: http://zipfind.net
b County population used as surrogate.
c Reference: EPA, 2006a.
dGPCO's hexavalent chromium monitor is at a separate, but adjacent location; as such, this site has two AQS codes.
-------
The 44 monitoring sites whose data have been included in the report previously are
listed in Table 2-2. In addition, six new sites that began sampling in 2007 are included in the
report for the first time.
At every NATTS or UATMP monitoring site, the sample collection equipment was
installed either in a temperature-controlled enclosure (usually a trailer or a shed) with the
sampling probe inlet exposed to the ambient air or as a stand-alone sampler. With this
common setup, every NATTS and UATMP monitoring site sampled ambient air at heights
approximately 5 to 20 feet above local ground level.
2.2 Analytical Methods Used and Pollutants Targeted for Monitoring
Urban air pollution typically contains hundreds of components, including, but not
limited to, volatile organic compounds (VOC), carbonyl compounds, metals, and particulate
matter. Because the sampling and analysis required to monitor for every component of air
pollution has been prohibitively expensive, the UATMP and NATTS programs primarily
focus on specific pollutants, as listed below. The target pollutants varied significantly from
monitoring site to monitoring site.
Compendium Method TO-15 was used concurrently with the SNMOC sampling
and analytical method to measure ambient air concentrations of 61 VOC and 80
ozone precursors.
Compendium Method TO-11A was used to measure ambient air concentrations of
15 carbonyl compounds.
Compendium Method TO-13A was used to measure ambient air concentrations of
19 SVOC.
Compendium MethodIO-3.5 was used to measure ambient air concentrations of
11 metals.
EPA-approved hexavalent chromium method was used to measure ambient air
concentrations of hexavalent chromium.
2-8
-------
Table 2-2. 2007 NATTS and UATMP Monitoring Sites and Past Program Participation
Monitoring Site
Azalea Park, St.
Petersburg, FL (AZFL)
Barceloneta, PR
(BAPR)
Boston, MA (BOMA)
Bountiful, UT (BTUT)
Bronx, NY (BXNY)
Camden, NJ (CANJ)
Chester, NJ (CHNJ)
Chesterfield, SC
(CHSQ
Custer, SD (CUSD)
Davie, FL (FLFL)
Dearborn, MI (DEMI)
Deer Park, TX
(CAMS 35)
Decatur, GA (SDGA)
Elizabeth, NJ (ELNJ)
1989
V
1990
1991
^
1992
^
^
1993
1994
-------
Table 2-2. 2007 NATTS and UATMP Monitoring Sites and Past Program Participation (Continued)
Monitoring Site
Gandy, Tampa, FL
(GAFL)
Gary, IN (INDEM)
Grand Junction, CO
(GPCO)
Gulfport, MS (GPMS)
Hazard, KY (HAKY)
Karnack, TX
(CAMS 85)
Los Angeles, CA
(CELA)
Loudon, TN (LDTN)
Loudon, TN (MSTN)
Mayville, WI (MVWI)
New Brunswick, NJ
(NBNJ)
Northbrook, IL (NBIL}
Phoenix, AZ (PXSS)
Phoenix, AZ (SPAZ)
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999/
2000a
2001
^
V
V
^
^
2002
V
v'
V
^
^
2003
^
^
^
V
^
^
^
2004
V
^
^
V
V
V
V
^
^
2005
^
^
^
^
^
V
-------
Table 2-2. 2007 NATTS and UATMP Monitoring Sites and Past Program Participation (Continued)
Monitoring Site
Providence, RI (PRRT)
Pryor, OK (CNEP)
Rochester, NY (ROCH)
Rubidoux, CA (RUCA)
San Juan, PR (SJPR)
Sault Ste. Marie, MI
(ITCMI)
Schiller Park, IL (SPIL)
Seattle, WA (SEWA)
Sioux Falls, SD (SFSD)
Skyview Elementary
School, Tampa, FL
(SKFL)
South Harding,
Indianapolis, IN (ININ)
St. Louis, MO (S4MO)
Stout Field,
Indianapolis, IL (IDIN)
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999/
2000a
'
2001
'
2002
'
'
2003
'
'
'
'
2004
'
'
'
'
'
2005
^
^
^
^
^
^
-
'
2006
^
^
^
^
^
^
^
'
^
^
^
2007
'
^
^
^
^
^
^
^
^
-
'
^
^
The time period for the 1999/2000 UATMP covers October 1999 to December 2000.
BOLD = EPA-designated NATTS site.
-------
Table 2-2. 2007 NATTS and UATMP Monitoring Sites and Past Program Participation (Continued)
Monitoring Site
Sydney, Plant City, FL
(SYFL)
Tulsa, OK (TOOK)
Tulsa, OK (TSOK)
Tulsa, OK (TUOK)
Tupelo, MS (TUMS)
Underbill, VT (VNVT)
Washington, D.C.
(WADC)
Washington Park,
Indianapolis, IN
(WPIN)
Winter Park, FL
(ORFL)
1989
1990
1991
^
1992
1993
1994
1995
1996
1997
1998
1999/
2000a
2001
'
2002
v'
'
2003
'
'
2004
'
S
<
2005
'
<
•f
<
<
2006
'
^
^
^
^
^
^
^
^
2007
'
^
^
^
^
^
^
^
^
to
I
to
The time period for the 1999/2000 UATMP covers October 1999 to December 2000.
BOLD = EPA-designated NATTS site.
-------
The detection limits of the analytical methods must be considered carefully when
interpreting the corresponding ambient air monitoring data. By definition, method detection
limits (MDLs) represent the lowest concentrations at which laboratory equipment have been
experimentally determined to reliably quantify concentrations of selected pollutants to a specific
confidence level. If a chemical concentration in ambient air does not exceed the method
sensitivity (as gauged by the detection limit), the analytical method might not differentiate the
pollutant from other pollutants in the sample or from the random Anoise@ inherent in laboratory
analyses. While quantification below the MDL is possible, the measurement reliability is lower.
Therefore, when samples contain concentrations at levels below their respective detection limits,
multiple analyses of the same sample may lead to a wide range of measurement results,
including highly variable concentrations or Anon-detect@ observations. Data analysts should
exercise caution when interpreting monitoring data with many reported concentrations at levels
near or below the corresponding detection limits.
MDLs are determined at the ERG laboratory using 40 CFR, Part 136 Appendix B
procedures (EPA, 2005a) in accordance with the specifications presented in the NATTS
Technical Assistance Document (TAD) (EPA, 2007a). This procedure involves analyzing at
least seven replicate standards prepared on/in the appropriate sampling media (per analytical
method). Instrument detection limits are not determined (replicates of standards only) because
sample contamination and preparation variability would not be considered. Tables 2-3 through
2-8 identify the specific target pollutants for each method and their corresponding MDLs. For
the VOC and SNMOC analyses, the experimentally-determined MDLs do not change unless the
sample was diluted. For the rest of the analyses, the MDLs may vary due to the actual volume
pulled through the sample. For these analyses, the range and average of each MDL is presented
for each pollutant in Appendix B.
Because non-detect results significantly limit the range of data interpretations for ambient
air monitoring programs, participating agencies should note that the approach for treating
non-detects may slightly affect the magnitude of the calculated central tendency concentrations,
especially for pollutants with a low detection rate. The non-detects were treated as valid data
2-13
-------
points. For purposes of risk analysis, non-detects were substituted with one-half of the MDL on
a target pollutant basis to calculate seasonal and annual averages.
The following discussion presents an overview of the sampling and analytical methods.
For detailed descriptions of the methods, readers should refer to EPA=s original documentation
of the Compendium Methods (EPA, 1996; EPA, 1998; EPA, 1999a; EPA, 1999b; EPA, 1999c;
EPA, 1999d; EPA, 2006b).
2.2.1 VOC and SNMOC Concurrent Sampling and Analytical Methods
VOC and SNMOC sampling and analysis can be performed concurrently in accordance
with a combination of EPA Compendium Method TO-15 and the procedure presented in EPA's
"Technical Assistance Document for Sampling and Analysis of Ozone Precursors" (EPA, 1998).
Ambient air samples for VOC analysis were collected in passivated stainless steel canisters. The
ERG laboratory distributed the prepared canisters (i.e., cleaned and evacuated) to the monitoring
sites before each scheduled sample collection event, and site operators connected the canisters to
air sampling equipment prior to each sampling day. Prior to field sampling, the passivated
canisters had internal pressures much lower than atmospheric pressure. Using this pressure
differential, ambient air naturally flowed into the canisters automatically once an associated
system solenoid valve was actuated. A mass flow controller on the sampling device inlet
ensured that ambient air entered the canister at an integrated constant rate across the collection
period. At the end of the 24-hour sampling period, the solenoid valve automatically stopped
ambient air from flowing into the canister. Site operators recovered and returned the canisters to
the ERG laboratory for analysis.
By analyzing each sample with gas chromatography incorporating mass spectrometry and
flame ionization detection (GC/MS-FID), laboratory staff determined ambient air concentrations
of 61 VOC, 80 SNMOC, and calculated the total nonmethane organic compounds (TNMOC)
concentration. TNMOC is the sum of all hydrocarbon concentrations within the sample.
Because isobutene and 1-butene elute from the GC column at the same time, the SNMOC
analytical method reports only the sum of the concentrations for these two compounds, and not
the separate concentration for each compound. The same approach applies to w-xylene andp-
2-14
-------
xylene for both the VOC and SNMOC methods. These raw data are presented in Appendices C
andD.
Laboratory analysts have indicated that acetonitrile values may be artificially high (or
nonexistent) due to site conditions and potential cross-contamination with concurrent sampling
of carbonyl compounds using Method TO-11 A. The inclusion of acetonitrile in data analysis
calculations needs to be determined on a site-specific basis by the agency responsible for the site.
As such, acetonitrile results are excluded from certain program-wide and site-specific data
analyses.
Table 2-3 presents the MDLs for the laboratory analysis of the VOC samples and
Table 2-4 presents the MDLs for the analysis of SNMOC samples. The MDL for every VOC is
lower than 0.042 parts per billion by volume (ppbv). SNMOC detection limits are expressed in
parts per billion carbon (ppbC). All of the SNMOC MDLs are less than 0.76 ppbC.
Table 2-3. VOC Method Detection Limits
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Tetrachloride
Carbon Bisulfide
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
MDL
(ppbv)
0.032
0.027
0.025
0.024
0.011
0.024
0.018
0.018
0.014
0.025
0.018
0.015
0.021
0.013
0.019
0.017
0.027
Pollutant
1 ,2-Dibromoethane
/w-Dichlorobenzene
o-Dichlorobenzene
£>-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
MDL
(ppbv)
0.013
0.015
0.016
0.015
0.018
0.016
0.021
0.022
0.017
0.016
0.015
0.019
0.015
0.015
0.021
0.015
0.008
Pollutant
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
w-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
Trichlorofluoromethane
Trichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 , 3 , 5-Trimethylbenzene
MDL
(ppbv)
0.016
0.014
0.009
0.007
0.039
0.012
0.016
0.011
0.017
0.040
0.016
0.017
0.018
0.022
0.021
0.010
0.010
2-15
-------
Table 2-3. VOC Method Detection Limits (Continued)
Pollutant
Chloromethylbenzene
Chloroprene
Dibromochloromethane
MDL
(ppbv)
0.011
0.013
0.014
Pollutant
Ethylbenzene
Hexachloro- 1 , 3 -butadiene
Methyl Ethyl Ketone
MDL
(ppbv)
0.012
0.036
0.041
Pollutant
Vinyl Chloride
/w./j-Xylene1
o-Xylene
MDL
(ppbv)
0.024
0.021
0.012
1 Because /w-xylene and^-xylene elute from the GC column at the same time, the VOC analytical method reports the sum
of ffj-xylene and^-xylene concentrations and not concentrations of the individual compounds.
Table 2-4. SNMOC Method Detection Limits1
Pollutant
Acetylene
Benzene
1,3 -Butadiene
w-Butane
c/s-2-Butene
trans-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
w-Decane
1-Decene
/w-Diethylbenzene
/>-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
w-Dodecane
1-Dodecene
Ethane
2-Ethyl-l-butene
Ethylbenzene
Ethylene
/w-Ethyltoluene
o-Ethyltoluene
/>-Ethyltoluene
MDL
(ppbC)
0.18
0.30
0.16
0.14
0.16
0.15
0.13
0.11
0.26
0.29
0.49
0.49
0.39
0.17
0.18
0.36
0.19
0.75
0.75
0.15
0.49
0.17
0.13
0.38
0.48
0.39
Pollutant
w-Heptane
1-Heptene
w-Hexane
1-Hexene
c/s-2-Hexene
/raws-2-Hexene
Isobutane
Isobutene/ 1 -Butene2
Isopentane
Isoprene
Isopropylbenzene
2-Methy 1-1 -butene
3 -Methyl- 1 -butene
2-Methyl-l-pentene
4-Methyl-l-pentene
2-Methyl-2-butene
Methylcyclohexane
Methylcyclopentane
2-Methy Iheptane
3 -Methy Iheptane
2-Methy Ihexane
3 -Methy Ihexane
2-Methylpentane
3-Methylpentane
w-Nonane
1-Nonene
MDL
(ppbC)
0.16
0.36
0.22
0.49
0.49
0.49
0.13
0.14
0.12
0.23
0.33
0.26
0.26
0.49
0.49
0.26
0.16
0.11
0.11
0.15
0.17
0.12
0.12
0.18
0.27
0.48
Pollutant
w-Octane
1-Octene
w-Pentane
1-Pentene
c/s-2-Pentene
/ra«s-2-Pentene
a-Pinene
yff-Pinene
Propane
w-Propylbenzene
Propylene
Propyne
Styrene
Toluene
w-Tridecane
1-Tridecene
1,2,3-Trimethylbenzene
1,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3,4-Trimethylpentane
w-Undecane
1-Undecene
/w-Xylene/^-Xylene2
o-Xylene
MDL
(ppbC)
0.21
0.36
0.12
0.15
0.26
0.18
0.49
0.49
0.17
0.34
0.15
0.17
0.36
0.34
0.75
0.75
0.35
0.47
0.32
0.36
0.17
0.17
0.36
0.36
0.27
0.20
1 Concentration in ppbC = concentration in ppbv x number of carbon atoms in compound.
2 Because isobutene and 1-butene elute from the GC column at the same time, the SNMOC analytical method reports the
sum of concentrations for these two compounds and not concentrations of the individual compounds. For the same
reason, the /w-xylene and^-xylene concentrations are reported as a sum.
2-16
-------
2.2.2 Carbonyl Sampling and Analytical Method
Following the specifications of EPA Compendium Method TO-11 A, ambient air samples
for carbonyl analysis were collected by passing ambient air through cartridges containing silica
gel coated with 2,4-dinitrophenylhydrazine (DNPH), a compound known to react selectively and
reversibly with many aldehydes and ketones. Carbonyl compounds in ambient air are retained in
the sampling cartridge, while other compounds pass through the cartridge without reacting with
the DNPH-coated matrix. As with the VOC sampling, the ERG laboratory distributed the DNPH
cartridges to the monitoring sites and site operators connected the cartridges to the air sampling
equipment. After each 24-hour sampling period, site operators recovered and returned the
cartridges to the ERG laboratory for chemical analysis.
To quantify concentrations of carbonyls in the sampled ambient air, laboratory analysts
eluted the exposed DNPH cartridges with acetonitrile. High-performance liquid chromatography
(HPLC) analysis and ultraviolet detection of these solutions determined the relative amounts of
individual carbonyls present in the original air sample. Because butyraldehyde and
isobutyraldehyde elute from the HPLC column at the same time, the carbonyl analytical method
reports only the sum of the concentrations for these compounds, and not the separate
concentration for each compound. For the same reason, the analytical method reports only the
sum of the concentrations for the three tolualdehydes isomers, as opposed to reporting the
separate concentration for the three individual compounds. These raw data are presented in
Appendix E.
Table 2-5 lists the MDLs reported by the ERG laboratory for measuring concentrations
of 15 carbonyl compounds. Although the sensitivity varies from pollutant-to-pollutant and from
site-to-site due to the different volumes pulled through the samples, the average detection limit
reported by the ERG laboratory for every pollutant is less than 0.013 ppbv.
2-17
-------
Table 2-5. Carbonyl Method Detection Limits
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde1
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes1
Valeraldehyde
Minimum
MDL
(ppbv)
0.0010
0.0020
0.0003
0.0007
0.0007
0.0004
0.0020
0.0004
0.0005
0.0006
0.0010
0.0006
Maximum
MDL
(ppbv)
0.0400
0.0720
0.0100
0.0200
0.0220
0.0170
0.0960
0.0130
0.0150
0.0190
0.0360
0.0220
Average
MDL
(ppbv)1
0.0052
0.0094
0.0013
0.0027
0.0028
0.0022
0.0127
0.0017
0.0019
0.0026
0.0047
0.0028
Because butyraldehyde/isobutyraldehyde elute from the HPLC column at the same time, the
carbonyl analytical method can report only the sum of concentrations for these two compounds
and not concentrations of the individual compounds. For the same reason, the analytical method
also reports only the sum of concentrations for the three tolualdehydes isomers, as opposed to
reporting separate concentrations for the three individual compounds.
2.2.3 Semivolatile Sampling and Analytical Method
Semivolatile sampling was performed in accordance with EPA Compendium Method
TO-13A. The ERG laboratory supplied prepared sampling media and received the samples from
the sites for analysis. Sample collection modules containing PUF and XAD-2® resin, petri
dishes containing filters, and Chain of Custody forms and all associated documentation, were
shipped to the ERG laboratory. Upon receipt of the collection modules, sample preparation and
analysis procedures follow Compendium Method TO-13 A. SVOC raw data are presented in
Appendix F. Table 2-6 lists the MDLs for the 19 SVOC target pollutants. MDLs for SVOC
ranged from 0.028 to 0.295 nanograms per cubic meters (ng/m3).
Table 2-6. SVOC Method Detection Limits
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Benzo (a) pyrene
Benzo (b) fluoranthene
Minimum
MDL
(ng/m3)
0.043
0.032
0.050
0.048
0.043
0.050
Maximum
MDL
(ng/m3)
0.213
0.158
0.248
0.238
0.216
0.251
Average
MDL
(ng/m3)
0.092
0.069
0.108
0.103
0.094
0.109
2-18
-------
Table 2-6. SVOC Method Detection Limits (Continued)
Pollutant
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
Indeno( 1,2,3 -cd)py rene
Naphthalene
Perylene
Phenanthrene
Pyrene
Minimum
MDL
(ng/m3)
0.049
0.044
0.051
0.044
0.039
0.049
0.028
0.044
0.047
0.057
0.050
0.059
0.035
Maximum
MDL
(ng/m3)
0.246
0.221
0.254
0.221
0.194
0.246
0.142
0.221
0.232
0.287
0.251
0.295
0.175
Average
MDL
(ng/m3)
0.107
0.096
0.110
0.096
0.084
0.107
0.062
0.096
0.101
0.124
0.109
0.128
0.076
2.2.4 Metals Sampling and Analytical Method
Sampling for the determination of metals in or on particulate matter was performed by
the sites in accordance with EPA Compendium Method IO-3.5. Filters with Chain of Custody
forms and all associated documentation were shipped to the ERG laboratory from the field.
Upon receipt, the filters were analyzed by the ERG laboratory. Metals raw data are presented in
Appendix G.
Table 2-7 lists the MDLs for the analysis of the metal samples. Two types of filters were
utilized. Sites sampled for either PMio or Total Suspended Paniculate (TSP), depending on the
site objectives, using either 47 mm Teflon® or 8 x 10" quartz filters. The different filter types
correspond to separate and distinct sampling apparatuses: the 47mm Teflon® filter is used for
low-volume samplers, where as the 8 x 10" quartz filter is used for high-volume samplers. Due
to the difference in sample volume/filter collection media, there are two sets of MDLs listed in
Table 2-7. The MDLs ranged from 0.006 to 0.948 ng/m3 for the quartz filters and from 0.06 to
3.88 ng/m3 for the Teflon® filters.
2-19
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Table 2-7. Metals Method Detection Limits
Pollutant
Minimum
MDL
(ng/m3)
Maximum
MDL
(ng/m3)
Average
MDL
(ng/m3)
8 X 10" Quartz Filters
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
0.006
0.009
0.012
0.008
0.142
0.009
0.018
0.016
0.009
0.088
0.018
0.067
0.060
0.133
0.057
0.948
0.067
0.181
0.156
0.062
0.587
0.120
0.010
0.009
0.020
0.008
0.144
0.010
0.023
0.017
0.009
0.089
0.018
Pollutant
Minimum
MDL
(ng/m3)
Maximum
MDL
(ng/m3)
Average
MDL
(ng/m3)
47mm Teflon® Filters
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
0.060
0.060
0.120
0.070
0.340
0.060
0.310
0.100
0.190
0.300
0.160
0.230
0.280
0.300
0.200
3.880
0.260
0.430
0.260
0.270
0.880
0.350
0.193
0.237
0.262
0.170
3.217
0.218
0.392
0.225
0.244
0.759
0.196
2.2.5 Hexavalent Chromium Sampling and Analytical Method
Hexavalent chromium was measured using an EPA-approved approach. For a detailed
description of the method, refer to the "Standard Operating Procedure for the Determination of
Hexavalent Chromium in Ambient Air Analyzed by Ion Chromatography (1C)" (EPA, 2006b).
The MDL is experimentally determined at the ERG laboratory for each site; the average MDL
for the program, which is presented in Table 2-8, was 0.0079 ng/m3. Raw data are presented in
Appendix H.
Table 2-8. Hexavalent Chromium Method Detection Limit
Pollutant
Hexavalent Chromium
Minimum
MDL
(ng/m3)
0.0062
Maximum
MDL
(ng/m3)
0.0118
Average
MDL
(ng/m3)
0.0079
2.3 Sample Collection Schedules
Table 2-9 presents the first and last date on which sample collection occurred for each
monitoring location. The monitoring sites started sampling in January 2007 and stopped
sampling in December 2007, with a few exceptions. Seven sites began sampling after January
2007:
• Los Angeles, CA site (CELA) started in April 2007;
2-20
-------
• Decatur, GA site (SDGA) started sampling SVOC in April 2007;
• Rubidoux, CA site (RUCA) started sampling in May 2007;
• South Phoenix, AZ site (SPAZ) started in July 2007;
• Phoenix, AZ site (PXSS) started sampling VOC, SVOC, and carbonyls in July 2007;
• Rochester, NY site (ROCH) started in October 2007; and
• Bronx, NY site (BXNY) started in October 2007.
Five sites ended sampling before December 2007:
• Davie, FL site (FLFL) ended in March 2007;
• Decatur, GA site (SDGA) stopped sampling hexavalent chromium in September
2007;
• Indianapolis, IN site (ININ) stopped sampling hexavalent chromium in October 2007;
• Puerto Rico sites (BAPR and SJPR) ended in June 2007.
According to the NATTS/UATMP schedule, 24-hour integrated samples were to be
collected at every monitoring site every l-in-6 or l-in-12 days (dependent upon location) and
each sample collection began and ended at midnight, local standard time. Table 2-9 shows the
following:
• VOC and carbonyl samples were collected concurrently at 23 sites.
• Of the 50 sites, 13 did not sample for VOC and/or carbonyls.
• Five sites sampled SVOCs.
• Five sites collected SNMOC samples.
• 11 sites collected metal samples.
• 19 sites collected hexavalent chromium samples.
2-21
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Table 2-9. Sampling Schedules and Completeness
Site
AZFL
BAPR
BOMA
BTUT
BXNY
CAMS 35
CAMS 85
CANJ
CELA
CHNJ
CHSC
CNEP
CUSD
Monitoring Period"
Starting
Date
1/6/07
1/6/07
1/6/07
1/6/07
10/4/07
1/18/07
1/6/07
1/6/07
4/30/07
1/6/07
1/6/07
1/6/07
1/6/07
Ending
Date
12/26/07
6/29/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/20/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
Carbonyl
A
60
29
60
57
55
60
B
60
29
62
59
62
60
C
100
100
97
97
89
100
voc
A
30
55
57
52
57
52
55
60
B
30
63
57
58
58
62
59
60
C
100
87
100
90
98
84
93
100
Hexavalent
Chromium
A
60
60
15
58
B
61
62
15
62
C
98
97
100
94
Metals
A
59
57
B
59
57
C
100
100
SNMOC
A
55
60
B
63
60
C
87
100
svoc
A
39
B
41
C
95
to
to
to
a Begins with 1st valid sample
A = Valid Samples
B = Total Number of Samples
C = Completeness (%)
BOLD = EPA-designated NATTS site.
Shading indicates a completeness below the DQO of 85%.
-------
Table 2-9. Sampling Schedules and Completeness (Continued)
Site
DEMI
ELNJ
FLFL
GAFL
GPCO
GPMS
HAKY
IDIN
INDEM
ININ
ITCMI
LDTN
MSTN
Monitoring Period"
Starting
Date
1/6/07
1/6/07
1/12/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
Ending
Date
12/26/07
12/26/07
3/13/07
12/26/07
12/26/07
12/25/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/27/07
12/27/07
Carbonyl
A
58
56
10
60
64
62
59
60
61
62
59
B
58
60
11
62
64
62
62
60
63
65
63
C
100
93
91
97
100
100
95
100
97
95
94
voc
A
59
61
62
61
60
60
B
60
62
64
62
64
63
C
98
98
97
98
94
95
Hexavalent
Chromium
A
61
59
60
50
B
62
61
61
51
C
98
97
98
98
Metals
A
60
60
B
60
60
C
100
100
SNMOC
A
61
B
62
C
98
svoc
A
55
B
57
C
96
to
to
a Begins with 1st valid sample
A = Valid Samples
B = Total Number of Samples
C = Completeness (%)
BOLD = EPA-designated NATTS site.
Shading indicates a completeness below the DQO of 85%.
-------
Table 2-9. Sampling Schedules and Completeness (Continued)
Site
MVWI
NBIL
NBNJ
ORFL
PRRI
PXSS
ROCH
RUCA
S4MO
SDGA
SEWA
SFSD
SJPR
Monitoring Period"
Starting
Date
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
10/3/07
5/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
Ending
Date
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
6/29/07
Carbonyl
A
58
61
58
30
60
59
59
29
B
60
65
58
30
61
60
59
29
C
97
94
100
100
98
98
100
100
voc
A
60
60
27
61
60
59
29
B
60
65
28
61
60
59
29
C
100
92
96
100
100
100
100
Hexavalent
Chromium
A
60
61
60
57
13
58
41
60
B
62
61
61
62
15
60
45
61
C
97
100
98
92
87
97
91
98
Metals
A
58
59
60
60
B
59
61
60
60
C
98
97
100
100
SNMOC
A
60
59
B
60
59
C
100
100
svoc
A
28
32
41
B
30
32
42
C
93
100
98
to
to
a Begins with 1st valid sample
A = Valid Samples
B = Total Number of Samples
C = Completeness (%)
BOLD = EPA-designated NATTS site.
Shading indicates a completeness below the DQO of 85%.
-------
Table 2-9. Sampling Schedules and Completeness (Continued)
Site
SKFL
SPAZ
SPIL
SYFL
TOOK
TSOK
TUMS
TUOK
UNVT
WADC
WPIN
Monitoring Period"
Starting
Date
1/6/07
7/5/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
1/6/07
Ending
Date
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
12/26/07
Overall
Carbonyl
A
60
60
60
61
58
58
61
56
1,820
B
62
60
60
63
59
60
63
58
1,869
C
97
100
100
97
98
97
97
97
97
voc
A
14
58
60
59
61
59
1,448
B
15
60
63
60
61
62
1,505
C
93
97
95
98
100
95
96
Hexavalent
Chromium
A
60
60
60
1,013
B
62
62
62
1,048
C
97
97
97
97
Metals
A
59
56
58
646
B
59
58
59
652
C
100
97
98
99
SNMOC
A
295
B
304
C
97
svoc
A
195
B
202
C
97
to
to
a Begins with 1st valid sample
A = Valid Samples
B = Total Number of Samples
C = Completeness (%)
BOLD = EPA-designated NATTS site.
Shading indicates a completeness below the DQO of 85%.
-------
As part of the sampling schedule, site operators were instructed to collect duplicate
samples on roughly 10 percent of the sampling days for select methods when duplicate samplers
were available. Sampling calendars were distributed to help site operators schedule the
collection of samples, duplicates, and field blanks. Field blanks were collected once a month for
carbonyl compounds, hexavalent chromium, metals, and SVOCs. In cases where monitors failed
to collect valid samples on a given scheduled sampling day, site operators were instructed to
reschedule samples for other days. This practice explains why some monitoring locations
periodically strayed from the l-in-6 or l-in-12 day sampling schedule.
The l-in-6 or l-in-12 day sampling schedule provides cost-effective approaches to data
collection for trends characterization of toxic pollutants in ambient air and ensures that sampling
days are evenly distributed among the seven days of the week to allow weekday/weekend
comparison of air quality. Because the l-in-6 day schedule yields twice the number of
measurements than the l-in-12 day schedule, data characterization based on this schedule tends
to be more representative.
2.4 Completeness
Completeness refers to the number of valid samples collected and analyzed compared to
the number of total samples attempted. Monitoring programs that consistently generate valid
results have higher completeness than programs that consistently have invalid samples. The
completeness of an air monitoring program, therefore, can be a qualitative measure of the
reliability of air sampling and laboratory analytical equipment and a measure of the efficiency
with which the program was managed. Appendix I identifies samples that were invalidated and
lists the specific reasons.
The following observations summarize the completeness of the monitoring data sets
collected during the 2007 NATTS/UATMP, as shown in Table 2-9:
• For VOC sampling, the completeness ranged from 84 to 100 percent, with an overall
completeness of 96 percent;
• For carbonyl sampling, the completeness ranged from 89 to 100 percent with an
overall completeness of 97 percent;
2-26
-------
• For SNMOC sampling, the completeness ranged from 87 to 100 percent with an
overall completeness of 97 percent;
• For SVOC sampling, the completeness ranged from 93 to 100 percent with an overall
completeness of 97 percent;
• For metals sampling, the completeness ranged from 97 to 100 percent with an overall
completeness was 99 percent; and
• For hexavalent chromium sampling, the completeness ranged from 87 to 100 percent,
with an overall completeness was 97 percent.
The data quality objective (DQO) for completeness based on the EPA-approved Quality
Assurance Project Plan (QAPP) specifies that 85-100 percent of samples collected at a given
monitoring site must be analyzed successfully to be considered sufficient for data trends analysis
(ERG, 2006/2007). The data in Table 2-9 shows that one data set (from a total of 100 data sets)
from the 2007 NATTS and UATMP monitoring sites did not meet this data quality objective
(shaded in Table 2-9). The CFDSTJ VOC data set was just below the 85 percent completeness
criteria (84 percent). This data set was lower than the 85 percent criteria because the site
experienced continual sampler malfunction. However, the sampler was exchanged mid-year,
and the sampler performance improved.
2-27
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3.0 Summary of the 2007 NATTS/UATMP Data Treatment and Methods
This section summarizes the data treatment and methods used to evaluate the data
collected during the 2007 NATTS/UATMP sampling year. These data were analyzed on a
program-wide basis as well as a site-specific basis. Results from the program-wide data analyses
are presented in Section 4.0 and results from the site-specific data analyses are presented in the
individual state sections, Sections 5.0 through 31.0.
A total of 190,745 valid urban air toxics concentrations (including non-detect, duplicate
analyses, replicate analyses, and analyses for collocated samples) were collected at 50 sites for
the 2007 NATTS/UATMP reporting year. A tabular presentation of the raw data and statistical
summary is found in Appendices C through O as follows:
Table 3-1. Overview and Layout of Data Presented
Pollutant Group
voc
SNMOC
Carbonyls
svoc
Metals
Hexavalent Chromium
# Sites
27
5
33
5
11
19
Appendix
Raw Data
C
D
E
F
G
H
Statistical Summary
J
K
L
M
N
O
3.1 Data Treatment
Section 3.0 examines the various statistical tools employed to characterize the data
collected during the 2007 sampling year. Certain data analyses were performed at the program-
level, other data analyses were performed both at a program-level and site-specific basis, and
still other approaches were reserved for site-specific data analyses only. Regardless of the data
analysis employed, it is important to understand how the concentration data were treated. The
following paragraphs describe techniques used to prepare this large quantity of data for data
analysis.
5-1
-------
All duplicate (or collocated) and replicate measurements were averaged in order to
calculate a single concentration for each pollutant for each sampling day at each site. This is
referred to as the preprocessed daily measurement.
Concentrations of m,/>-xylene and o-xylene were summed together and are henceforth
referred to as "total xylenes," "xylenes (total)," or simply "xylenes" throughout the remainder of
this report, with a few exceptions. Section 4.1 examines the results of basic statistical
calculations performed on the dataset. However, in Table 4-1 and Table 4-4, which are the
method-specific statistics for VOC and SNMOC, respectively, the xylenes results are retained as
m,p-xy\ene and o-xylene species. This is also true of the Quality Assurance section (Section
31.0).
In order to compare concentrations across multiple sampling methods, all concentrations
have also been converted to a common unit of measure: microgram per cubic meter (ug/m3).
However, whenever a particular sampling method is isolated from others, such as in Tables 4-1
through 4-6, the statistical parameters are presented in the units of measure associated with the
particular sampling method. As such, it is important to pay very close attention to the unit of
measure associated with each analysis discussed in this and subsequent sections of the report.
3.2 Approach to Risk Screening and Pollutants of Interest
Each year, a subset of pollutants is selected for further data analyses. A practical
approach to making an assessment on a large number of measurements is to focus on a subset of
pollutants based on the end-use of the dataset. In UATMP reports prior to 2003, this subset was
based on the frequency and magnitude of concentrations (previously called "prevalent
compounds"). Since the 2003 UATMP report, risk-based calculations have been used to identify
"pollutants of interest." EPA defines risk as "the probability that damage to life, health, and/or
the environment will occur as a result of a given hazard (such as exposure to a toxic chemical)"
(EPA, 2006c). For the 2007 NATTS/UATMP report, the pollutants of interest are also based on
risk potential.
5-2
-------
EPA has published a guidance document outlining a risk screening approach that utilizes
a risk-based methodology for performing an initial screen of ambient air toxics monitoring data
sets (EPA, 2006d). This screening process provides a risk-based methodology for analysts and
interested parties to identify which pollutants may pose a risk in their area. Not all
NATTS/UATMP pollutants have screening values; of the 172 pollutants sampled under these
programs, 106 pollutants have screening values. Those that have screening values are also
referred to as HAPs, since they are known or suspected to cause cancer or other serious health
effects such as reproductive effects or birth defects, or adverse environmental and ecological
effects. EPA is required to control 188 HAPs (EPA, 2007c). The screening values used in this
analysis are presented in Appendix P.
Preprocessed daily measurements of the target pollutants were compared to these risk
screening values in order to identify pollutants of interest across the program. The following risk
screening process was completed to identify pollutants of interest:
1. If a pollutant was measured by two separate methods at the same site and that yield
similar results, such as measuring benzene with VOC and SNMOC methods, then the
two concentrations were averaged together. The purpose was to have one
concentration per pollutant per day per site. Metals sampled from different sized
particulate matter yield different results. Therefore, the results were not averaged
together.
2. Each 24-hour speciated measurement was compared against the screening value.
Concentrations that were greater than the screening value are described as "failing the
screen."
3. The number of failed screens was summed for each applicable pollutant. The number
of failures for each metal was summed together to determine the total number of
failed screens for each applicable pollutant.
4. The percent contribution of the number of failed screens to the total number of failed
screens program-wide was calculated for each applicable pollutant.
5. The pollutants contributing to the top 95 percent of the total failed screens were
identified as pollutants of interest.
In regards to step 5, the actual cumulative contribution may exceed 95 percent in order to
include all pollutants contributing to the minimum 95 percent criteria (refer to Table 4-7 for an
5-3
-------
example). In addition, if the 95 percent cumulative criterion is reached, but the next pollutant
contributed equally to the number of failed screens, that pollutant was also designated as a
pollutant of interest. Results of the risk screening process are provided in Section 4.2.
3.3 Risk Screening Evaluation Using Minimum Risk Levels
In addition to the risk screening described above, a risk screening was also conducted
using the Agency for Toxic Substances and Disease Registry (ATSDR) Minimal Risk Level
(MRL) factors (ATSDR, 2007a). An MRL is a concentration of a hazardous substance that is
"without appreciable risk of adverse noncancer health effects over a specified duration of
exposure" (ATSDR, 2007b). MRLs are intended to be used as screening tools, similar to the risk
screening approach discussed above. ATSDR defines MRLs for three durations of exposure:
acute, intermediate, and chronic exposure. Acute risk results from exposures of 1 to 14 days;
intermediate risk results from exposures of 15 to 364 days; and chronic risk results from
exposures of one year or greater. For this risk screening evaluation, the preprocessed daily
measurements were compared to the acute MRLs; seasonal averages were compared to the
intermediate MRL; and annual averages were compared to the chronic MRL.
The daily average of a particular pollutant is simply the average concentration of all
measured detections. If there were at least seven measured detections within each season, then a
seasonal average was calculated. The seasonal average includes 1/2 MDL substitutions for all
non-detects. The substitution of 1/2 MDL for non-detects may have a significant impact on
pollutants that are rarely measured at or above the associated detection limit and/or have a
relatively high MDL. A seasonal average was not calculated for pollutants with less than seven
measured detections in a respective season. The spring season included concentrations from
March, April, and May; summer includes June, July, and August; autumn includes September,
October, and November; and winter includes December, January, and February. An annual
average includes all measured detections and 1/2 MDL substituted values for non-detects.
Annual averages were calculated for monitoring sites where sampling began no later than
February and ended no earlier than November, and where method completeness was greater than
or equal to 85 percent. Although this analysis was based on site-specific concentrations and
averages, the number of exceedances has been summed to the program-level.
5-4
-------
ATSDR recently published an updated acute MRL for acrolein. The previous acute MRL
was 0.11 ug/m3; the new acute MRL is 7 ug/m3, which is an order of magnitude higher than the
previous MRL. ATSDR updated the acute MRL for acrolein based on a higher Lowest
Observed Adverse Effect Level (LOAEL) of 0.3 ppm and with endpoints of decrease in
respiratory rate and nose and throat irritations, as documented in ATSDR's 2007 toxicological
profile for acrolein (ATSDR, 2007c). The basis for the former acute MRL is documented in the
1990 toxicological profile for acroelin (ATSDR, 1990). As a result of the new acute MRL,
considerably fewer exceedances of the acute MRL are expected. The intermediate MRL (0.09
ug/m3) for acrolein used in the 2006 UATMP report is still applicable. The MRLs used in this
analysis have one significant figure and are presented in Appendix P.
CAL EPA relative exposure limits (RELs) were used for acute risk assessment in
addition to the ATSDR MRLs in the 2006 UATMP report. These factors are no longer being
used because the duration of exposure is generally 1 hour, which was determined to be too
dissimilar to the 24-hour concentrations for a legitimate comparison.
3.4 Pearson Correlations
This report uses Pearson correlation coefficients to measure the degree of correlation
between two variables. By definition, Pearson correlation coefficients always lie between -1 and
+1. Three qualification statements apply:
• A correlation coefficient of -1 indicates a perfectly Anegative@ relationship,
indicating that increases in the magnitude of one variable are associated with
proportionate decreases in the magnitude of the other variable, and vice versa.
• A correlation coefficient of+1 indicates a perfectly Apositive@ relationship,
indicating that the magnitudes of two variables both increase and both decrease
proportionately.
• Data that are completely uncorrelated have Pearson correlation coefficients of 0.
Therefore, the sign (positive or negative) and magnitude of the Pearson correlation coefficient
indicate the direction and strength, respectively, of data correlations. In this report, correlation
coefficients greater than 0.50 or less than -0.50 are classified as strong, while correlation
coefficients less than 0.50 and greater than -0.50 are classified as weak.
5-5
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When calculating correlations among the NATTS/UATMP data, several measures were
taken to identify spurious correlations and to avoid introducing bias to the correlations:
• Data correlations were calculated only for the program-level pollutants of interest,
which are identified in Section 4.2, or the site-specific pollutants of interest identified
in each state section.
• Correlations were calculated from the processed NATTS/UATMP monitoring data in
which each pollutant has just one numerical concentration for each successful
sampling date, or the preprocessed daily measurements. Non-detects were not
included in this analysis.
The number of observations used in a calculation is an important factor to consider when
analyzing the correlations. A correlation using few observations may skew the correlation,
making the degree of correlation appear higher than it may actually be. In this report, five data
points must be available to present a correlation.
Pearson correlation coefficients are used in several different ways in this report,
including determining the degree of correlation between concentration data and meteorological
conditions as well as between concentration data and site-characterizing variables such as motor
vehicle activity.
3.5 Additional Program-Level Analyses of the 2007 NATTS/UATMP Dataset
This section provides a summary of additional analyses performed on the 2007
NATTS/UATMP dataset at the program level. Additional program-level analyses include an
examination of the potential impact of motor vehicles and a review of how concentrations vary
among the sites themselves and from season-to-season. The results of these analyses are
presented in Sections 4.3 and 4.4.
3.5.1 The Impact of Mobile Source Emissions on Spatial Variations
Mobile source emissions from motor vehicles contribute significantly to air pollution in
urban environments. "Mobile sources" refer to emitters of air pollutants that move, or can be
moved, from place to place and include both on-road and non-road emissions (EPA, 2008a).
Pollutants found in motor vehicle exhaust generally result from incomplete combustion of
-------
vehicle fuels. Although modern vehicles and, more recently, vehicle fuels have been engineered
to minimize air emissions, all motor vehicles with internal combustion engines emit a wide range
of chemical pollutants. The magnitude of these emissions in urban areas primarily depends on
the volume of traffic, while the chemical profile of these emissions depends more on vehicle
design and fuel formulation. This report uses a variety of parameters to quantify and evaluate
the impact of motor vehicle emissions on ambient air quality, which are discussed further in
Section 4.3:
• Emissions data from the NEI;
• Total hydrocarbon concentrations;
• Motor vehicle ownership data;
• Estimated daily traffic volume;
• Vehicle miles traveled (VMT);
• BTEX concentration profiles; and
• Ethylene-Acetylene tracer analysis.
3.5.2 Variability Analyses
Variability refers to the degree of difference among values in a data set. Two types of
variability are analyzed for this report. The first type examines the coefficient of variation for
each of the pollutants of interest across the NATTS/UATMP sites. The coefficient of variation
provides a relative measure of variability by expressing standard deviation to the magnitude of
the arithmetic mean. It is particularly useful when comparing different sets of data because it is
unitless (Taylor, et al.,1999). In this report, variability across data distributions for different sites
and different pollutants are compared. The coefficients of variation are shown in the form of a
scatter plot, where data points represent the coefficients of variation and a trend line is plotted to
show linearity. Pollutants of interest whose data points are clustered together indicate
uniformity in how the concentrations are dispersed among the sites. This suggests that
concentrations are affected by typical and consistent sources (e.g., mobile sources). Data points
that are not clustered suggest the likelihood of a stationary source not typically found in most
urban areas (e.g., coke manufacturing facility).
5-7
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Seasonal variability is the second type of variability assessed in this report. The
concentration data for each site were divided into the four seasons, as described in Section 3.3.
The measured detection criteria, also described in Section 3.3, is maintained here as well. The
site-specific calculated seasonal averages are illustrated by bar graphs for each pollutant of
interest. This analysis allows the reader to determine if there is a seasonal correlation with the
magnitude of concentrations for a specific pollutant. The seasonal analysis should agree
somewhat with the Pearson coefficient correlations calculated on the site-specific level, and are
discussed further in the state sections.
3.5.3 Greenhouse Gas Assessment
Currently, there is considerable discussion about climate change amongst atmospheric
and environmental scientists. Climate change refers to an extended period of change in
meteorological variables used to determine climate, such as temperature and precipitation.
Greenhouse gases (GHGs) are those that cause heat to be retained in the atmosphere (EPA,
2008b). Many scientists agree that the atmospheric temperature is increasing. As such, a great
deal of research on the relationship between greenhouse gases and climate change has been
conducted and continues to be investigated.
Agencies researching the effects of greenhouse gases tend to concentrate primarily on
tropospheric levels of these gases. The troposphere is the lowest level of the atmosphere, which
extends between 5 and 12 miles high, depending on season and latitude. This is also the layer in
which weather phenomenon occur (Weather Questions.com). A handful of VOCs measured with
the Method TO-15 are greenhouse gases, although these measurements reflect the concentration
at the surface, or in the breathing zone, and do not represent the entire troposphere. Section 4.5
presents the 10 GHGs currently measured with the Method TO-15, their Global Warming
Potential (GWP), and the average concentration across the program. GWP is a way to determine
a pollutant's ability to retain heat relative to carbon dioxide, which is one of the predominant
anthropogenic GHGs in the atmosphere (EPA, 2008c and NOAA, 2008). In the future,
additional GHG pollutants may be added to the Method TO-15 target pollutant list in order to
assess their surface level ambient concentrations.
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3.6 Additional Site-Specific Analyses
In addition to many of the analyses described in the preceding sections, the state-specific
sections (5.0 through 31.0) contain additional analyses that are applicable only at a local level.
This section provides an overview of these analyses but does not discuss their results. Results of
these site-specific analyses are presented in the state-specific sections.
3.6.1 Emission Tracer Analysis
Pollution roses were created for each of the site-specific pollutants of interest that
exceeded the acute risk factors to help identify the geographical area where the emission sources
of these pollutants may have originated. A pollution rose is a plot of the ambient concentration
versus the unit vector of the wind direction; high concentrations can be shown in relation to the
direction of potential emissions sources.
3.6.2 Back Trajectory Analysis
A back trajectory traces the origin of an air parcel in relation to the location where it is
currently being measured. The method of constructing a back trajectory uses the Lagrangian
frame of reference. In simplest terms, an air parcel can be traced back one hour to a new point of
reference based on the current measured wind speed and direction. At this new point of
reference (that is now one hour prior to the current observation), the wind speed and direction
are used again to determine where the air was one hour before. Back trajectory calculations are
also governed by other meteorological parameters, such as pressure and temperature. Each time
segment is referred to as a "time step." Although back trajectories may be modeled for extended
periods of time (weeks), trajectories for this report were constructed for durations of 24 hours to
match the 24-hour sampling duration.
Gridded meteorological data and the model used for back trajectory analyses were
prepared and developed by the National Oceanic and Atmospheric Administration (NOAA)
using data from the National Weather Service (NWS) and other cooperative agencies. The
model used is the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) (Draxler,
R.R. and Rolph, G.D., 2003). Back trajectories were computed for each sampling day, and a
composite back trajectory map was constructed for each monitoring site using Geographical
5-9
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Information System (GIS) software. Trajectories are modeled with an initial height of 250
meters above ground level (AGL), and each sampling day's trajectory is plotted to create a
composite back trajectory map. One value of the composite back trajectory map is the
estimation of a 24-hour air shed domain for each site. An air shed domain is the geographical
area surrounding a site from which an air parcel may typically travel within the 24-hour time
frame. Agencies can use the air shed domain to evaluate regions where long-range transport
may affect their monitoring site.
3.6.3 Wind Rose Analysis
Wind roses were constructed for each site to help identify the predominant direction from
which the wind blows. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses color or shading to represent wind speeds. Wind roses are constructed by
uploading hourly surface wind data from the nearest weather station into a wind rose software
program, WRPLOT (Lakes, 2006). A wind rose is often used in determining where to install an
ambient monitoring site when trying to capture emissions from an upwind source. A wind rose
may also be useful in determining whether high concentrations correlate with a specific wind
direction. While the composite back trajectory maps show where a parcel of air originated on a
number of days, the wind rose shows the frequency at which wind speed and direction are
measured near the monitoring site. Thus, the back trajectory analysis focuses on long range
transport, while the wind rose captures day-to-day fluctuations at the surface. Both are used to
identify potential meteorological influences on the monitoring sites.
3.6.4 Site Trends Analysis
Table 2-2 presented current monitoring sites that have participated in the
NATTS/UATMP in previous years. Site-specific trends analyses were conducted for sites with
at least five years of data analyzed under the National Monitoring Programs contract. The
approach to this trends analysis is described below and the results are presented in the individual
state sections (Sections 5.0 through 31.0).
In previous years, trends graphs were created for sites with three years of concentration
data for formaldehyde, benzene, and 1,3-butadiene. Beginning with the 2007 report, site-
3-10
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specific trends graphs for each of the NATTS core compounds are presented (EPA, 2007a),
based on the availability of data. NATTS core compounds are those that the program has chosen
to focus on due to their ability to adversely affect human health. The six NATTS core
compounds are as follows:
• acrolein (measured by Method TO-15);
• arsenic (as measured by Method IO-3.5);
• benzene (as measured by both Method TO-15 and SNMOC method);
• 1,3-butadiene (measured by Method TO-15 method);
• formaldehyde (measured by Method TO-11A method); and
• hexavalent chromium (as measured by the EPA-approved method developed by
ERG).
Trends graphs from previous UATMP reports presented all three pollutants'
concentrations on one graph. Due to the large variation in magnitude of the concentrations
among the pollutants and the sites, each figure for this year's trends analysis presents data for
one pollutant only, thus enabling the reader to better interpret the figures.
The trends figures and subsequent analysis for the 2007 report are presented as three-year
rolling statistical metrics. In previous reports, daily averages, as defined in Section 3.3, were
presented in bar graphs for each year for sites with at least three years of data analyzed under the
National Monitoring Programs contract. For 2007, the following criteria were used to calculate
valid rolling statistical metrics:
• Sampling for one or more of the NATTS core compounds;
• analysis performed under the National Monitoring Programs contract; and
• at least five years of concurrent data.
For the 2007 program year, 18 sites met the criteria for three-year rolling statistical metrics to be
calculated.
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The three-year rolling statistical metrics graphs are presented as box and whisker plots or
simply boxplots, an example of which can be seen in Figure 9-22. Boxplots show the minimum
and maximum concentration measured during the three-year period (as shown by the upper and
lower value of the lines extending from the box); the first, second, and third quartiles, or 25th,
50th (or median), and 75th percentiles, (as shown by the y-values corresponding with the bottom,
gray line, or top of the box, respectively); and the three-year rolling average concentration (as
denoted by the white diamond). Each rolling metric represents all measurements from that three
year period. The inclusion of the rolling average, which is traditionally not represented in a box
and whisker plot, allows for a smoothing of raw data in order to identify long-term trends
(Stockcharts.com).
Data used in this analysis were downloaded from EPA's AQS database (EPA, 2008d).
Non-detects are uploaded into AQS as zeros (EPA, 2007a), thus, the approach for calculating
rolling averages presented in this section is slightly different than approaches used in other data
analyses in the 2007 report. As such, zeros representing non-detects were used in these
calculations. However, samples with precision data (duplicates, collocates, and/or replicates)
were still averaged together to allow for the determination of a single concentration value per
pollutant per site per date, reflecting the data treatment described in Section 3.1.
3.6.5 Cancer and Noncancer Surrogate Risk Approximations
In February 2006, EPA released the results of its national-scale air toxics assessment,
NAT A, for base year 1999 (EPA, 2006c). NAT A uses the NEI for HAP as its starting point, but
also incorporates ambient monitoring data, geographic information, and chemical/physical
transformation information to model ambient concentrations at the census tract level. Cancer
and noncancer risk factors are then applied to the modeled concentrations to yield census tract-
level cancer and noncancer risk values.
Cancer risk is defined as the likelihood of developing cancer as a result of exposure over
a 70-year period, and is presented as the number of people at risk for cancer per million people
(EPA, 2006c). The cancer risks presented in this report estimate the cancer risk due to exposure
at the modeled concentration over a 70-year period, not the risk resulting from exposure over the
3-12
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time period covered in this report. A cancer risk greater than 1.0 in-a-million is considered
significant. Noncancer risk is presented as the Noncancer Hazard Quotient (HQ). Noncancer
health effects include conditions such as asthma. "If the HQ is calculated to be less than 1.0,
then no adverse health effects are expected as a result of exposure, if the HQ is greater than 1.0
the adverse health effects are possible" (EPA, 2006c). NATA is a useful resource that helps
federal and state/local/tribal agencies identify potential areas of air quality concern.
NATA risk factors applied to calculate cancer and noncancer risks are typically cancer
unit risk estimates (UREs) and noncancer reference concentrations (RfCs), which are developed
by EPA. However, UREs and RfCs are not available for all pollutants. In the absence of EPA
values, risk factors developed by agencies with credible methods and that are similar in scope
and definition were used (EPA, 2005b).
National pollutant drivers are those that affect more than 25 million people, whereas
regional driver pollutants affect more than 10 million people, as defined by NATA. Several of
the program-level and site-specific pollutants of interest are HAP that were identified as NATA
driver pollutants (EPA, 2006c):
• acrolein (national noncancer);
• benzene (national cancer);
• 1,3-butadiene (regional cancer and noncancer);
• carbon tetrachloride (regional cancer);
• tetrachloroethylene (regional cancer).
Chronic cancer and noncancer risk estimates were retrieved from the 1999 NATA for
each site's respective census tract (e.g., the CNEP monitoring site is located in census tract
40097040400). Using the cancer URE and noncancer RfC factors, modeled census tract-level
concentrations were back-calculated for any pollutants that failed at least one screen for each
monitoring site. NATA-modeled concentrations are assumed to be the average concentration
that a person breathed for an entire year. Census tract-level data from EPA's 1999 NATA are
presented in each state section.
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Cancer URE and noncancer RfC factors can be applied to the annual averages to
approximate surrogate chronic risk estimates based on ambient monitoring data. While these
risk approximations do not incorporate human activity patterns and therefore do not reflect true
human inhalation exposure, they may allow analysts to further refine their focus by 1)
identifying concentrations of specific pollutants that may present health risks and 2) determining
if the approximations are similar or dissimilar to the results from NATA. Cancer UREs and/or
noncancer RfCs, site-specific annual averages, and corresponding annual average-based
surrogate chronic risk approximations are presented in each state section.
It is important to note that although the most recent results from NATA were published in
2006, they are based on emissions data for the base year 1999. EPA cautions users of NATA
from making direct comparisons across different base years. Although it may be useful to see if
the concentration profiles are similar, readers must exercise caution when interpreting the results
presented in these tables and drawing conclusions, given the age of the data from NATA.
According to EPA, the results from NATA may be used to prioritize pollutants and emission
sources, identify locations of interest for further investigation, provide a starting point for local-
scale assessments, focus community efforts, and inform monitoring programs, but should not be
used as a sole means for identifying localized hotspots, as a definitive means to pinpoint specific
risk values within a census tract, to characterize or compare risks at local levels such as between
neighborhoods, as the sole basis for developing risk reduction plans or regulations, to control
specific sources or pollutants, or quantify benefits of reduced air toxic emissions (EPA, 2008f).
3.6.6 Risk-Based Emissions Assessment
A pollutant emitted in high quantities does not necessarily present a higher risk to human
health than a pollutant emitted in very low quantities. The more toxic the pollutant, the more
risk associated with its emissions in ambient air. The development of various health-based risk
factors has allowed analysts to apply weight to the emissions of pollutants based on toxicity
rather than mass emissions. This approach incorporates both a pollutant's toxicity potential and
the quantity emitted.
3-14
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This assessment compares county-level emissions to toxicity-weighted emissions based
on the EPA-approved approach described below (EPA, 2007b). The 10 pollutants with the
highest total mass emissions and the associated toxicity-weighted emissions for pollutants with
cancer and noncancer toxicity factors are presented in each state section. While the absolute
magnitude of the pollutant-specific toxicity-weighted emissions is not meaningful, the relevant
magnitude of toxicity-weighted emissions is useful in identifying the order of potential priority
for air quality managers. Higher values suggest greater priority; however, even the highest
values may not reflect potential cancer effects greater than a level of concern (1 in-a-million) or
potential noncancer effects above levels of concern (e.g., HQ = 1). The pollutants exhibiting the
10 highest annual average-based surrogate chronic cancer and noncancer risk approximations are
also presented in each state section. The results of this data analysis may help state, local, and
tribal agencies better understand which pollutants emitted, from a toxicity basis, are of the
greatest concern.
The toxicity-weighted emissions approach consists of the following steps:
1. Obtain HAP emissions data for all anthropogenic sectors from the NEI. For point
sources, sum the process-level emissions to the county-level.
2. Apply the mass extraction speciation profiles to extract metal and cyanide mass. The
only exception is for two chromium species: chromium and chromium compounds.
3. For chromium and chromium compounds, trivalent chromium (non-toxic) must be
separated from hexavalent chromium (toxic). To do this, apply the chromium
speciation profile to extract the hexavalent chromium mass by industry group.
4. Apply weight to the emissions derived from the steps above based on their toxicity.
a. To apply weight based on cancer toxicity, multiply the emissions of each
pollutant by its cancer URE.
b. To apply weight based on noncancer toxicity, divide the emissions of each
pollutant by its noncancer RfC.
3-15
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4.0 Summary of the 2007 NATTS/UATMP Data
This section summarizes the results of the data analyses performed on the dataset as
described in Section 3.0.
4.1 Statistical Results
This section examines different statistical parameters for each analytical method:
1) number of measured detections, 2) concentration ranges and data distribution, and 3) central
tendency statistics. Sections 4.1.1 through 4.1.3 review the basic findings of these statistical
calculations.
4.1.1 Target Pollutant Detections
Every pollutant has an MDL as described in Section 2.2. Quantification below the MDL
is possible, although the measurement's reliability is lower. If a concentration does not exceed
the MDL, it does not mean that the pollutant is not present in the air. If the method does not
produce a concentration, the measurement is marked as ND, or "non-detect." As explained in
Section 2.2, data analysts must exercise caution when interpreting monitoring data with many
reported concentrations at levels near or below the corresponding MDLs. Therefore, a thorough
review of the number of measured detections, the number of non-detects, and the total number of
samples is beneficial to understanding the representativeness of the interpretations made.
Tables 4-1 through 4-6 summarize the number of times the target pollutants were
detected out of the number of valid samples collected and analyzed. Approximately 52 percent
of the pollutants sampled were measured above the MDLs (including non-detect, duplicate
analyses, replicate analyses, and analyses for collocated samples). The percentages listed below
represent the percent of measurements that were above the MDLs:
• 39.5 percent of VOC;
• 84.9 percent of carbonyl compounds;
• 45.4 percent of SNMOC;
• 87.3 percent of metals;
4-1
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Table 4-1. Statistical Summaries of the VOC Concentrations
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Tetrachloride
Carbon Bisulfide
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
/w-Dichlorobenzene
o-Dichlorobenzene
£>-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
#of
Measured
Detections"
1332
1445
1433
157
30
1448
1
56
20
1415
1353
1446
1252
94
1176
1241
1446
8
27
102
1
33
30
1150
1447
18
48
9
6
34
Minimum
(ppbv)
0.010
0.015
0.030
0.006
0.001
0.005
Maximum
(ppbv)
311.928
10.800
2.950
0.911
0.007
2.430
0.004
0.005
0.001
0.004
0.004
0.007
0.005
0.001
0.005
0.004
0.014
0.002
0.003
0.001
1.020
0.031
0.895
4.580
0.175
64.100
0.115
0.808
2.290
1.390
0.008
0.079
0.335
0.003
0.002
0.002
0.002
0.008
0.003
0.004
0.004
0.040
0.003
0.099
0.017
0.586
6.710
0.024
1.290
0.060
0.200
0.092
Arithmetic
Mean
(ppbv)
2.455
0.763
0.322
0.121
0.003
0.309
Mode
(ppbv)
0.170
1.010
0.160
0.008
0.002
0.140
Median
(ppbv)
0.368
0.519
0.249
0.083
0.002
0.242
Geometric
Mean
(ppbv)
0.466
0.550
0.252
0.070
0.003
0.247
First
Quartile
(ppbv)
0.172
0.323
0.159
0.040
0.002
0.156
Third
Quartile
(ppbv)
1.033
0.913
0.400
0.123
0.004
0.382
Standard
Deviation
(ppbv)
13.724
0.807
0.268
0.153
0.002
0.238
Coefficient
of
Variation
5.590
1.058
0.830
1.263
0.529
0.772
NA
0.073
0.009
0.018
0.047
0.096
1.982
0.042
0.021
0.048
0.602
0.005
0.024
0.016
0.020
0.004
0.010
0.030
0.080
0.020
0.010
0.010
0.020
0.420
0.006
0.026
0.002
0.020
0.007
0.012
0.030
0.095
0.442
0.045
0.014
0.024
0.589
0.005
0.020
0.006
0.026
0.007
0.013
0.031
0.092
0.312
0.031
0.016
0.029
0.584
0.004
0.017
0.006
0.016
0.005
0.010
0.017
0.082
0.032
0.020
0.010
0.018
0.516
0.003
0.011
0.003
0.034
0.010
0.014
0.054
0.110
2.114
0.060
0.020
0.037
0.658
0.006
0.030
0.010
0.185
0.007
0.053
0.131
0.023
4.826
0.025
0.037
0.114
0.146
0.002
0.019
0.047
2.517
0.789
2.870
2.774
0.246
2.434
0.587
1.744
2.355
0.243
0.404
0.797
2.878
NA
0.010
0.008
0.025
0.536
0.008
0.108
0.025
0.096
0.028
0.004
0.004
0.010
0.494
0.004
0.010
0.006
NA
0.008
0.005
0.007
0.013
0.520
0.005
0.012
0.023
0.075
0.018
0.006
0.007
0.015
0.523
0.007
0.028
0.018
0.082
0.020
0.004
0.004
0.008
0.487
0.004
0.010
0.006
0.054
0.010
0.008
0.010
0.026
0.564
0.010
0.063
0.040
0.123
0.036
0.017
0.004
0.044
0.187
0.006
0.245
0.019
0.056
0.025
1.754
0.519
1.762
0.349
0.716
2.267
0.728
0.581
0.887
1 Number of measured detections out of 1,448 valid samples.
NA = Statistical parameter(s) could not be calculated.
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Table 4-1. Statistical Summaries of the VOC Concentrations (Continued)
Pollutant
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
w-Octane
Propylene
Styrene
1, 1,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
Trichlorofluoromethane
Trichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
7w,£>-Xylene
o-Xylene
#of
Measured
Detections"
1445
4
o
6
4
1445
1
1
1447
11
1425
1253
114
273
1321
1448
1301
10
1306
1448
47
1447
29
571
1440
1447
1433
1374
283
1446
1446
Minimum
(ppbv)
0.010
0.007
0.012
0.007
0.002
Maximum
(ppbv)
72.400
0.009
0.051
0.038
0.306
0.004
0.044
0.005
0.002
0.012
0.001
0.001
0.001
0.004
0.034
0.002
0.002
0.003
0.007
0.003
0.003
0.003
0.002
0.003
0.008
0.003
0.001
0.002
0.005
0.004
1.408
0.059
11.900
2.470
2.480
2.130
0.634
41.500
1.540
0.008
2.200
36.900
0.122
0.470
0.028
1.060
3.430
3.350
0.878
0.230
0.156
4.720
1.710
Arithmetic
Mean
(ppbv)
0.222
0.008
0.037
0.023
0.018
Mode
(ppbv)
0.070
0.007
NA
NA
0.016
Median
(ppbv)
0.086
0.008
0.049
0.023
0.016
Geometric
Mean
(ppbv)
0.101
0.008
0.031
0.018
0.016
First
Quartile
(ppbv)
0.062
0.007
0.031
0.009
0.015
Third
Quartile
(ppbv)
0.135
0.008
0.050
0.037
0.018
Standard
Deviation
(ppbv)
2.010
0.001
0.018
0.014
0.017
Coefficient
of
Variation
9.044
0.107
0.480
0.629
0.939
NA
NA
0.081
0.016
0.526
0.061
0.211
0.065
0.038
0.618
0.048
0.005
0.038
0.780
0.012
0.020
0.007
0.034
0.276
0.104
0.066
0.022
0.011
0.228
0.083
0.020
0.010
0.150
0.020
0.027
0.010
0.010
0.350
0.010
0.002
0.010
0.270
0.007
0.016
0.004
0.010
0.230
0.100
0.010
0.010
0.005
0.040
0.020
0.053
0.010
0.349
0.036
0.059
0.026
0.025
0.313
0.026
0.005
0.021
0.404
0.009
0.017
0.006
0.020
0.255
0.100
0.042
0.016
0.006
0.129
0.052
0.053
0.010
0.351
0.038
0.074
0.027
0.027
0.338
0.028
0.004
0.023
0.438
0.009
0.018
0.006
0.022
0.259
0.099
0.042
0.016
0.007
0.130
0.053
0.028
0.005
0.189
0.021
0.028
0.012
0.016
0.183
0.015
0.003
0.012
0.212
0.007
0.015
0.004
0.012
0.235
0.090
0.022
0.009
0.004
0.065
0.028
0.097
0.017
0.611
0.063
0.217
0.046
0.045
0.527
0.048
0.007
0.040
0.880
0.013
0.020
0.008
0.034
0.287
0.109
0.086
0.029
0.010
0.260
0.102
0.097
0.017
0.649
0.128
0.345
0.189
0.045
1.617
0.088
0.002
0.091
1.408
0.017
0.021
0.005
0.062
0.170
0.094
0.071
0.022
0.018
0.326
0.103
1.197
1.053
1.234
2.112
1.636
2.935
1.192
2.618
1.836
0.442
2.416
1.806
1.373
1.053
0.774
1.828
0.614
0.899
1.078
0.972
1.581
1.429
1.232
a Number of measured detections out of 1,448 valid samples.
NA = Statistical parameter(s) could not be calculated.
-------
Table 4-2. Statistical Summaries of the Carbonyl Compound Concentrations
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2, 5 -Dimethylbenzaldehy de
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
#of
Measured
Detections"
1820
1820
1801
1814
1803
13
1820
1773
540
1801
1771
1777
Minimum
(ppbv)
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Maximum
(ppbv)
17.70
17.10
0.51
2.43
1.80
0.06
135.00
1.52
0.65
5.54
0.78
2.52
Arithmetic
Mean
(ppbv)
1.31
1.25
0.04
0.12
0.14
0.02
3.39
0.07
0.04
0.16
0.04
0.06
Mode
(ppbv)
1.02
1.32
0.02
0.06
0.03
0.01
2.12
0.01
0.01
0.09
0.02
0.03
Median
(ppbv)
1.00
0.93
0.03
0.08
0.06
0.02
2.03
0.03
0.02
0.11
0.03
0.03
Geometric
Mean
(ppbv)
1.02
0.89
0.03
0.09
0.08
0.02
2.10
0.03
0.03
0.11
0.03
0.04
First
Quartile
(ppbv)
0.66
0.52
0.02
0.06
0.04
0.01
1.27
0.02
0.01
0.07
0.02
0.02
Third
Quartile
(ppbv)
1.59
1.64
0.05
0.14
0.16
0.02
3.34
0.05
0.05
0.17
0.05
0.05
Standard
Deviation
(ppbv)
1.13
1.12
0.05
0.14
0.18
0.02
6.48
0.14
0.05
0.24
0.05
0.10
Coefficient
of
Variation
0.86
0.89
1.16
1.20
1.34
0.74
1.91
2.15
1.29
1.55
1.11
1.82
1 Number of measured detections out of 1,820 valid samples.
-------
Table 4-3. Statistical Summaries of the SVOC Concentrations
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Benzo (a) pyrene
Benzo (b) fluoranthene
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
Indeno( 1,2,3 -cd)pyrene
Naphthalene
Perylene
Phenanthrene
Pyrene
#of
Measured
Detections"
188
125
121
168
170
161
133
169
150
188
116
28
193
194
117
195
34
195
193
Minimum
(ng/m3)
0.03
0.04
0.02
0.01
0.02
0.02
0.02
0.02
0.01
0.01
0.02
0.01
0.02
0.04
0.02
0.27
0.02
0.06
0.02
Maximum
(ng/m3)
9.48
7.98
7.13
0.98
0.85
1.32
0.92
0.91
1.03
1.80
0.36
0.19
6.77
8.30
0.93
220.00
0.23
29.50
3.76
Arithmetic
Mean
(ng/m3)
1.99
1.30
0.48
0.10
0.27
0.17
0.15
0.14
0.13
0.21
0.09
0.05
1.66
2.87
0.15
61.98
0.06
6.72
0.98
Mode
(ng/m3)
1.82
0.14
0.43
0.10
0.27
0.13
0.06
0.10
0.03
0.13
0.11
NA
1.02
3.66
0.13
75.80
NA
11.00
1.32
Median
(ng/m3)
1.78
0.54
0.26
0.04
0.25
0.09
0.09
0.08
0.06
0.13
0.06
0.04
1.24
2.81
0.09
53.00
0.06
5.43
0.81
Geometric
Mean
(ng/m3)
1.46
0.63
0.25
0.06
0.23
0.10
0.10
0.10
0.07
0.14
0.07
0.04
1.27
2.29
0.10
37.86
0.05
5.02
0.78
First
Quartile
(ng/m3)
0.93
0.26
0.12
0.03
0.17
0.05
0.05
0.05
0.03
0.08
0.04
0.03
0.89
1.65
0.05
28.55
0.03
3.57
0.54
Third
Quartile
(ng/m3)
2.67
1.60
0.45
0.10
0.34
0.20
0.18
0.16
0.15
0.24
0.11
0.06
2.05
3.66
0.16
92.40
0.07
9.01
1.32
Standard
Deviation
(ng/m3)
1.44
1.63
0.90
0.13
0.14
0.21
0.15
0.16
0.16
0.23
0.07
0.04
1.24
1.62
0.16
45.53
0.04
4.49
0.66
Coefficient
of
Variation
0.72
.25
.85
.38
0.52
.22
.00
.10
.29
.11
0.79
0.70
0.75
0.56
1.07
0.73
0.71
0.67
0.68
1 Number of measured detections out of 195 valid samples.
NA = Statistical parameter(s) could not be calculated.
-------
Table 4-4. Statistical Summaries of the SNMOC Concentrations
Pollutant
Acetylene
Benzene
1,3 -Butadiene
w-Butane
c/s-2-Butene
/rans-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
w-Decane
1-Decene
/w-Diethylbenzene
£>-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
w-Dodecane
1-Dodecene
Ethane
2-Ethyl-l-butene
Ethylbenzene
Ethylene
ffj-Ethyltoluene
o-Ethyltoluene
£>-Ethyltoluene
w-Heptane
1-Heptene
#of
Measured
Detections"
295
293
183
279
260
285
294
284
86
287
2
197
98
283
284
287
284
275
151
295
0
294
294
265
243
268
294
233
Minimum
(ppbC)
0.40
0.19
0.03
0.51
0.02
0.05
0.05
0.03
0.10
0.03
0.10
0.05
0.02
0.03
0.03
0.05
0.03
0.02
0.03
0.87
Maximum
(ppbC)
19.90
39.70
0.94
97.20
2.08
4.93
6.89
8.86
1.51
25.40
0.35
1.66
2.38
2.37
5.28
6.25
3.40
48.10
1.41
107.00
Arithmetic
Mean
(ppbC)
1.90
1.70
0.15
5.62
0.22
0.30
0.53
0.55
0.33
0.72
0.23
0.31
0.23
0.33
0.45
0.60
0.32
0.80
0.27
8.33
Mode
(ppbC)
1.34
1.41
0.08
4.56
0.12
0.14
0.10
0.35
0.12
0.42
NA
0.14
0.05
0.33
0.24
0.44
0.17
0.10
0.06
11.00
Median
(ppbC)
1.48
1.14
0.11
3.12
0.18
0.25
0.29
0.25
0.25
0.32
0.23
0.22
0.11
0.26
0.31
0.37
0.23
0.19
0.16
6.15
Geometric
Mean
(ppbC)
1.52
1.24
0.11
3.58
0.16
0.23
0.32
0.29
0.27
0.34
0.18
0.23
0.12
0.25
0.30
0.37
0.22
0.23
0.17
6.58
First
Quartile
(ppbC)
0.97
0.79
0.07
2.00
0.09
0.14
0.17
0.15
0.16
0.17
0.16
0.14
0.07
0.15
0.16
0.20
0.12
0.10
0.08
4.38
Third
Quartile
(ppbC)
2.20
1.74
0.17
6.62
0.29
0.34
0.52
0.46
0.39
0.58
0.29
0.38
0.20
0.43
0.52
0.62
0.37
0.40
0.31
9.27
Standard
Deviation
(ppbC)
1.80
2.67
0.13
8.19
0.21
0.36
0.72
1.01
0.26
2.16
0.13
0.30
0.39
0.29
0.54
0.73
0.36
3.60
0.28
8.98
Coefficient
of
Variation
0.95
1.57
0.89
1.46
0.96
1.21
1.35
1.84
0.80
3.00
0.57
0.95
1.70
0.87
1.20
1.22
1.11
4.51
1.06
1.08
NA
0.03
0.41
0.04
0.04
0.03
0.07
0.04
5.31
15.20
2.10
57.90
4.57
7.65
1.31
0.62
2.43
0.40
0.52
0.27
0.68
0.19
1.49
1.70
0.29
0.07
0.24
0.14
0.13
0.45
1.94
0.32
0.20
0.20
0.36
0.14
0.43
1.99
0.31
0.21
0.20
0.40
0.15
0.23
1.29
0.18
0.12
0.13
0.22
0.10
0.77
2.93
0.51
0.36
0.32
0.63
0.22
0.61
1.80
0.30
3.70
0.34
1.05
0.17
0.98
0.74
0.76
7.17
1.25
1.53
0.86
1 Number of measured detections out of 295 valid samples.
NA = Statistical parameter(s) could not be calculated.
-------
Table 4-4. Statistical Summaries of the SNMOC Concentrations (Continued)
Pollutant
w-Hexane
1-Hexene
c/s-2-Hexene
trans-2-tlexene
Isobutane
Isobutene/ 1 -Butene
Isopentane
Isoprene
Isopropylbenzene
2-Methyl-l-butene
3 -Methyl- 1 -butene
2-Methyl-l-pentene
4-Methyl-l-pentene
2-Methyl-2-butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3-Methylhexane
2-Methylpentane
3-Methylpentane
w-Nonane
1-Nonene
w-Octane
1-Octene
w-Pentane
1-Pentene
c/s-2-Pentene
#of
Measured
Detections"
295
266
28
26
295
192
238
265
149
261
20
47
9
230
288
294
224
248
259
287
294
294
292
119
293
136
295
293
196
Minimum
(ppbC)
0.09
0.04
0.04
0.05
0.26
0.10
0.35
0.03
0.03
0.03
0.18
0.03
0.04
0.06
0.03
0.07
0.02
0.03
0.05
0.11
0.27
0.08
0.04
0.02
0.04
0.04
0.21
0.05
0.03
Maximum
(ppbC)
53.80
0.69
0.60
0.83
126.00
23.50
132.00
9.71
5.97
11.80
3.92
0.43
0.36
2.08
9.63
8.65
2.07
1.62
8.24
11.90
17.70
10.10
5.13
2.15
4.24
3.48
339.00
175.00
0.86
Arithmetic
Mean
(ppbC)
1.67
0.21
0.21
0.16
4.87
2.45
13.43
1.06
0.16
0.58
1.18
0.11
0.09
0.30
0.57
0.68
0.21
0.21
0.78
0.84
1.68
0.89
0.33
0.21
0.39
0.19
6.82
1.74
0.17
Mode
(ppbC)
1.14
0.09
0.05
0.05
1.19
1.49
10.90
0.35
0.13
0.20
NA
0.06
NA
0.26
0.23
1.24
0.11
0.15
0.56
1.50
1.06
0.74
0.19
0.12
0.34
0.09
2.25
0.28
0.12
Median
(ppbC)
0.76
0.17
0.13
0.12
1.80
1.87
10.80
0.39
0.12
0.30
1.00
0.09
0.06
0.25
0.25
0.47
0.13
0.15
0.52
0.48
1.25
0.64
0.20
0.14
0.26
0.13
2.46
0.37
0.15
Geometric
Mean
(ppbC)
0.84
0.17
0.14
0.12
2.22
1.66
9.97
0.46
0.11
0.31
0.84
0.09
0.07
0.25
0.30
0.48
0.14
0.16
0.50
0.53
1.27
0.63
0.22
0.15
0.27
0.14
2.77
0.44
0.14
First
Quartile
(ppbC)
0.40
0.10
0.06
0.08
1.09
1.08
6.55
0.17
0.08
0.15
0.39
0.06
0.05
0.16
0.16
0.28
0.09
0.10
0.28
0.30
0.79
0.34
0.12
0.09
0.16
0.09
1.36
0.21
0.10
Third
Quartile
(ppbC)
1.37
0.31
0.30
0.19
4.04
2.66
16.15
1.46
0.15
0.73
1.67
0.14
0.08
0.35
0.53
0.78
0.27
0.26
0.83
0.81
2.07
1.06
0.35
0.24
0.41
0.22
4.88
0.63
0.22
Standard
Deviation
(ppbC)
3.88
0.14
0.18
0.15
11.07
2.72
13.29
1.40
0.48
1.09
0.97
0.07
0.09
0.23
0.91
0.77
0.22
0.19
1.01
1.37
1.60
0.95
0.45
0.26
0.48
0.31
25.60
10.64
0.11
Coefficient
of
Variation
2.33
0.66
0.87
0.96
2.27
1.11
0.99
1.32
2.98
1.87
0.82
0.66
1.05
0.76
1.60
1.12
1.07
0.90
1.30
1.63
0.95
1.06
1.36
1.24
1.22
1.60
3.75
6.12
0.64
1 Number of measured detections out of 295 valid samples.
NA = Statistical parameter(s) could not be calculated.
-------
Table 4-4. Statistical Summaries of the SNMOC Concentrations (Continued)
Pollutant
/ra«s-2-Pentene
a-Pinene
6-Pinene
Propane
w-Propylbenzene
Propylene
Propyne
Styrene
Toluene
w-Tridecane
1-Tridecene
1 ,2,3 -Trimethylbenzene
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3 ,4-Trimethyrpentane
w-Undecane
1-Undecene
/w-Xylene/^-Xylene
o-Xylene
SNMOC (Sum of Knowns)
Sum of Unknowns
TNMOC
#of
Measured
Detections"
269
230
62
295
255
295
0
115
295
57
3
229
292
225
209
294
289
288
91
295
295
295
295
295
Minimum
(ppbC)
0.03
0.06
0.01
0.77
0.03
0.29
0.05
0.39
0.04
0.09
0.03
0.04
0.03
0.04
0.08
0.05
0.03
0.02
0.10
0.04
15.60
4.22
29.70
Maximum
(ppbC)
1.43
5.64
4.75
358.50
0.76
8.99
3.89
109.00
5.95
0.35
0.86
3.68
1.42
2.13
9.58
3.21
101.00
1.19
18.90
5.25
943.00
591.00
1140.00
Arithmetic
Mean
(ppbC)
0.25
0.77
0.94
13.28
0.18
1.24
0.63
4.84
0.36
0.19
0.16
0.59
0.24
0.25
0.85
0.38
1.30
0.14
1.67
0.61
90.59
68.01
158.29
Mode
(ppbC)
0.28
1.03
1.30
10.60
0.13
1.05
0.20
1.61
0.09
NA
0.12
1.13
0.19
0.11
0.47
0.07
0.37
0.05
1.51
1.28
111.00
57.90
126.00
Median
(ppbC)
0.22
0.58
0.62
7.35
0.15
0.95
N
0.43
2.90
0.15
0.14
0.14
0.47
0.19
0.17
0.51
0.28
0.30
0.08
1.07
0.43
64.38
46.80
116.00
Geometric
Mean
(ppbC)
0.19
0.53
0.59
8.21
0.15
1.03
A
0.43
2.85
0.17
0.16
0.13
0.45
0.19
0.18
0.56
0.27
0.36
0.10
1.06
0.43
69.21
47.24
124.18
First
Quartile
(ppbC)
0.13
0.28
0.34
4.49
0.10
0.70
0.25
1.39
0.09
0.11
0.08
0.27
0.12
0.10
0.31
0.14
0.17
0.05
0.54
0.24
45.45
25.23
78.45
Third
Quartile
(ppbC)
0.32
1.02
1.30
14.45
0.23
1.43
0.76
4.96
0.26
0.24
0.21
0.72
0.31
0.28
0.97
0.48
0.61
0.16
1.95
0.73
99.56
80.00
179.00
Standard
Deviation
(ppbC)
0.19
0.72
0.89
24.66
0.12
0.99
0.66
8.10
0.86
0.11
0.12
0.51
0.20
0.25
1.08
0.37
7.25
0.16
1.94
0.62
101.65
71.45
142.33
Coefficient
of
Variation
0.77
0.93
0.95
1.86
0.66
0.80
1.04
1.67
2.38
0.60
0.73
0.86
0.83
1.02
1.28
0.96
5.59
.16
.17
.02
.12
.05
0.90
oo
1 Number of measured detections out of 295 valid samples.
NA = Statistical parameter(s) could not be calculated.
-------
Table 4-5. Statistical Summaries of the Metals Concentrations
Pollutant
Antimony (PM10)
Arsenic (PM10)
Beryllium (PM10)
Cadmium (PM10)
Chromium (PM10)
Cobalt (PM10)
Lead (PM10)
Manganese (PM10)
Mercury (PM10)
Nickel (PM10)
Selenium (PM10)
Antimony (TSP)
Arsenic (TSP)
Beryllium (TSP)
Cadmium (TSP)
Chromium (TSP)
Cobalt (TSP)
Lead (TSP)
Manganese (TSP)
Mercury (TSP)
Nickel (TSP)
Selenium (TSP)
#of
Measured
Detections3'11
473
473
461
473
472
472
473
473
458
473
471
173
173
171
173
173
173
173
173
173
173
173
Minimum
(ng/m3)
0.01
0.02
0.000
0.03
0.97
0.004
0.09
0.17
0.00
0.15
0.01
0.18
0.19
O.001
0.05
1.01
0.13
1.57
1.48
0.01
0.36
0.08
Maximum
(ng/m3)
9.68
44.10
0.07
1.93
12.20
6.53
57.30
91.70
25.50
29.00
11.90
4.48
49.10
0.09
4.84
7.93
6.29
43.30
131.00
1.43
26.90
12.43
Arithmetic
Mean
(ng/m3)
1.36
0.97
0.01
0.27
2.64
0.22
6.04
9.64
0.59
1.61
0.88
0.97
1.32
0.02
0.25
2.23
0.88
6.33
22.53
0.10
1.82
1.12
Mode
(ng/m3)
1.40
1.09
0.004
0.10
1.88
0.22
3.15
10.60
0.01
1.05
0.32
1.03
1.13
0.01
0.16
1.71
0.22
10.50
16.80
0.02
1.47
1.24
Median
(ng/m3)
0.93
0.69
0.01
0.17
2.32
0.14
4.30
6.86
0.03
1.21
0.57
0.81
0.78
0.01
0.17
1.95
0.48
5.33
18.30
0.04
1.37
0.86
Geometric
Mean
(ng/m3)
0.97
0.69
0.01
0.18
2.43
0.14
4.55
6.71
0.04
1.28
0.54
0.80
0.80
0.01
0.18
2.07
0.56
5.26
17.52
0.04
1.43
0.80
First
Quartile
(ng/m3)
0.59
0.44
0.003
0.10
1.82
0.08
2.95
3.57
0.01
0.88
0.27
0.51
0.52
0.01
0.12
1.61
0.29
3.62
10.90
0.02
0.98
0.49
Third
Quartile
(ng/m3)
1.46
1.04
0.01
0.32
3.23
0.24
6.70
12.80
0.08
1.68
1.19
1.19
1.09
0.02
0.26
2.61
0.96
7.36
28.45
0.07
1.94
1.38
Standard
Deviation
(ng/m3)
1.41
2.17
0.01
0.30
1.19
0.38
6.11
9.55
3.46
1.98
0.99
0.66
3.88
0.01
0.39
1.01
1.11
4.92
17.59
0.21
2.27
1.26
Coefficient
of
Variation
1.04
2.23
1.12
1.09
0.45
1.73
1.01
0.99
5.84
1.23
1.13
0.68
2.94
0.84
1.57
0.45
1.26
0.78
0.78
2.03
1.25
1.13
1 For PM10 number of measured detections out of 473 valid samples.
3 For TSP number of measured detections out of 173 valid samples.
-------
Table 4-6. Statistical Summaries of the Hexavalent Chromium Concentrations
Pollutant
Hexavalent Chromium
#of
Measured
Detections"
709
Minimum
(ng/m3)
0.001
Maximum
(ng/m3)
0.42
Arithmetic
Mean
(ng/m3)
0.03
Mode
(ng/m3)
0.01
Median
(ng/m3)
0.02
Geometric
Mean
(ng/m )
0.02
First
Quartile
(ng/m3)
0.01
Third
Quartile
(ng/m3)
0.04
Standard
Deviation
(ng/m3)
0.04
Coefficient
of
Variation
1.20
1 Number of measured detections out of 1,013 valid samples.
-------
• 74.4 percent of SVOC; and
• 59.7 percent of hexavalent chromium samples.
Some pollutants are always detected while others are infrequently detected. Similar to
previous years, acetaldehyde and acetone had the greatest number of measured detections
(1,820), using the preprocessed daily measurements. These pollutants were reported in every
valid sample collected (1,820). Formaldehyde was also detected in every carbonyl sample
collected in 2007. Toluene, propylene, and benzene were detected in every VOC sample
collected (1,448), although fewer VOC samples were collected compared to carbonyls.
Antimony, nickel, manganese, arsenic, lead, and cadmium were detected in every metal sample
collected (646). Nine pollutants (isobutene, ethane, xylenes, propane, propylene, toluene,
w-pentane, w-hexane, and acetylene) were detected in every SNMOC sample collected. Benzene
is also a pollutant measured by the SNMOC method. While it was detected in every VOC
sample collected in 2007, two non-detects were reported by the concurrent SNMOC method.
Further review showed that benzene was present in these samples, but co-eluted with another
compound during analysis and could not be separated to a degree to allow for individual
quantitation. According to ERG's approved procedures, the measurements were reported as
non-detects.
Naphthalene and phenanthrene were detected in every SVOC sample collected.
Hexavalent chromium was detected in approximately 70 percent of samples collected. Only two
pollutants, 2-ethyl-l-butene and propyne had zero measured detections. Both pollutants are
SNMOC.
NBIL had the greatest number of measured detections (6,403 out of a possible 9,675
valid data points). In previous years, BTUT had the greatest number of measured detections
(6,392 out of 8,997 for 2007). However, BTUT's detection rate (71 percent) is higher than
NBIL's (66 percent). Detection rates for sites that sampled pollutants that are frequently
detected tended to be higher (refer to the list of method-specific percentages of measurements
above the MDL listed above). For example, metals rarely reported as non-detects. As a result,
sites (such as BOMA) that sampled only metals would likely have higher detection rates.
4-11
-------
BOMA's detection rate is 97 percent. Conversely, VOCs had the lowest detection rate (39.5
percent). A site measuring only VOC would likely have lower detection rates, such as CNEP
(46.8 percent).
4.1.2 Concentration Range
The concentrations measured during the 2007 NATTS/UATMP show a wide range of
variability. The following observations were made in regards to the measured detections at the
program level:
• Nearly 81 percent of the measured detections had concentration values less than
1 jug/m3, while less than 3 percent had concentrations greater than 5 jug/m3.
• VOC had the highest number of samples with concentrations greater than 5 jug/m3
(900); SNMOC had the least (585); and carbonyl compounds were in the middle
(748). SVOC, metals, and hexavalent chromium had no concentrations greater than
5 //g/m3.
• A pollutant had a measurement greater than 5 jug/m3 on 85 of 124 total sampling days.
• Concentrations of 72 pollutants never exceeded 1 jug/m3.
• Six sites had maximum concentration values over 100 jug/m3.
• BTUT had the greatest number of samples with concentrations greater than 5 jug/m3
(317, out of a possible 8,997 valid data points), which is similar to previous years.
CUSD had the next highest number of samples with concentrations greater than
5 jug/m3 (161).
The minimum and maximum concentration measured for each target pollutant is also
presented in Tables 4-1 through 4-6 (in respective pollutant group units). Some pollutants, such
as acetonitrile, had a large range of concentrations measured, while other pollutants, such as
carbon tetrachloride, did not, even though they were detected frequently. The pollutant for each
method-specific pollutant group with the largest range in measured concentrations is as follows:
• For VOC, acetonitrile (0.01 to 311.93 ppbv)
• For SNMOC, propane (0.77 to 358.50 ppbC)
• For carbonyl compounds, formaldehyde (0.01 to 135.0 ppbv)
4-12
-------
• For SVOC, naphthalene (0.27 to 220.0 ng/m3)
• For metals, both sizes, manganese (0.17 to 91.7 ng/m3 forPMio and 1.48 to 131.0
ng/m3 for TSP).
On July 4, 2006, a large number of monitoring sites that sampled for hexavalent
chromium measured elevated concentrations. Hexavalent chromium is a component in fireworks
(NLM, 2008) and it is possible that Independence Day fireworks celebrations may have caused
this increased concentration level. Based on the l-in-6 sampling schedule for 2007, samples
were collected on July 5, 2007. Although a few sites experienced elevated concentrations on
July 5, 2007, most concentrations did not vary much on this date from other samples collected
throughout the year. Additional studies of this phenomena were recommended in the 2006
UATMP Report.
4.1.3 Summary Statistics
In addition to the number of measured detections and the concentration ranges,
Tables 4-1 through 4-6 also present a number of central tendency and data distribution statistics
(arithmetic mean, geometric mean, median, mode, first and third quartiles, standard deviation,
and coefficient of variation) for each of the pollutants sampled during the 2007 NATTS/UATMP
program year by respective pollutant group units. A multitude of observations can be made from
these tables. As such, the three highest average concentrations, by mass, for each pollutant
group is provided below:
The top three VOCs by average mass concentration, as presented in Table 4-1, are:
• acetonitrile (2.45 ppbv);
• carbon disulfide (1.98 ppbv); and
• toluene (0.78 ppbv).
The top three carbonyl compounds by average mass concentration, as presented in
Table 4-2, are:
• formaldehyde (3.39 ppbv);
4-13
-------
• acetaldehyde (1.31 ppbv); and
• acetone (1.2 5 ppbv).
The top three SVOC by average mass concentration, as presented in Tables 4-3, are:
• naphthalene (61.98 ng/m3);
• phenanthrene (6.72 ng/m3); and
• fluorene(2.87ng/m3).
The top three SNMOC by average mass concentration, as presented in Table 4-4, are:
• isopentane (13.43 ppbC);
• propane (13.28 ppbC); and
• ethane (8.33 ppbC).
The top three metals by average mass concentration for both PMio and TSP fractions, as
presented in Table 4-5, are;
• manganese (TSP = 22.53 ng/m3, PMIO = 9.64 ng/m3);
• lead (TSP= 6.33 ng/m3, PMIO = 6.04 ng/m3); and
• total chromium (TSP = 2.23 ng/m3, PMIO = 2.64 ng/m3).
The average mass concentration of hexavalent chromium, as presented in Table 4-6, is
0.033 ng/m3.
Appendices J through O present similar statistical calculations, but are based on each
individual sample, including duplicate, collocated, and replicate analyses, rather than the
preprocessed daily measurements (as presented here).
4-14
-------
4.2 Risk Screening and Pollutants of Interest
Section 3.2 described the process for identifying the program-wide pollutants of interest.
Table 4-7 identifies the pollutants that failed at least one screen; summarizes each pollutant's
total number of measured detections, percentage failed, and cumulative percentage of failed
screens; and highlights those pollutants designated as the program-wide "pollutants of interest."
Concentrations of 31 HAPs, of the 106 HAPs with screening values, failed at least one
screen (29 percent). Of these, a total of 11,731 of 25,207 concentrations (46.54 percent) failed
screens, as shown in Table 4-7. By comparison, for the 2006 programs, 45.55 percent of
applicable HAP measurements failed screens. If all of the pollutants with screening values are
considered (including those that did not fail any screens), the percentage of concentrations
failing screens is less (11,731 of 42,871, or 27.36 percent).
Table 4-7 shows that acetaldehyde failed the largest number of screens (1,777), and also
had the highest number of measured detections (1,820). This is equivalent to a 97.64 percent
failure rate. Although formaldehyde had the same number of measured detections as
acetaldehyde, it failed screens fewer times (1,644 failures, or a 90.33 percent failure rate).
Acrolein exhibited a 100 percent failure rate when detected (1,433 failures out of 1,433
measured detections). Pollutants bolded in Table 4-7 indicate the designation of an EPA
NATTS core compound as discussed in Section 3.6.4.
Using the approach described in Section 3.2, the program-level pollutants of interest, as
indicated by the shading in Table 4-7, were identified as follows:
• Acetaldehyde
• Acrylonitrile
• Acrolein
• Arsenic
• Benzene
• 1,3-Butadiene
4-15
-------
Table 4-7. Program-Level Risk Screening Summary
Pollutant
Acetaldehyde
Formaldehyde
Benzene
Carbon Tetrachloride
Acrolein
1,3-Butadiene
Arsenic
Tetrachloroethylene
£>-Dichlorobenzene
Manganese
Acrylonitrile
Naphthalene
Nickel
Hexavalent Chromium
Cadmium
Dichloromethane
1 ,2-Dichloroethane
Trichloroethylene
Bromomethane
Carbon Bisulfide
Vinyl chloride
1 , 1 ,2,2-Tetrachloroethane
Hexachloro- 1 ,3 -butadiene
Xylenes
Chloromethylbenzene
1,1,2-Trichloroethane
Methyl fer/-Butyl Ether
Toluene
Chloroform
w-Hexane
1 ,2-Dibromoethane
Total
# of Failed
Screens
1777
1644
1444
1443
1433
1139
624
552
487
463
155
145
112
64
57
46
41
28
16
11
11
8
8
7
5
3
2
2
2
1
1
11,731
#of
Measured
Detections
1820
1820
1448
1446
1433
1362
646
1306
1150
646
157
195
646
709
646
1445
48
571
1415
1252
283
10
11
1447
8
29
273
1448
1241
295
1
25,207
%of
Failed
Screens
97.64
90.33
99.72
99.79
100.00
83.63
96.59
42.27
42.35
71.67
98.73
74.36
17.34
9.03
8.82
3.18
85.42
4.90
1.13
0.88
3.89
80.00
72.73
0.48
62.50
10.34
0.73
0.14
0.16
0.34
100.00
46.54
%of
Total
Failures
15.15
14.01
12.31
12.30
12.22
9.71
5.32
4.71
4.15
3.95
1.32
1.24
0.95
0.55
0.49
0.39
0.35
0.24
0.14
0.09
0.09
0.07
0.07
0.06
0.04
0.03
0.02
0.02
0.02
0.01
0.01
Cumulative
%
Contribution
15.15
29.16
41.47
53.77
65.99
75.70
81.02
85.72
89.87
93.82
95.14
96.38
97.33
97.88
98.36
98.76
99.10
99.34
99.48
99.57
99.67
99.74
99.80
99.86
99.91
99.93
99.95
99.97
99.98
99.99
100.00
BOLD = EPA NATTS core compound.
4-16
-------
• Carbon Tetrachloride
• />-Dichlorobenzene
• Formaldehyde
• Manganese
• Tetrachloroethylene
The 2007 list of pollutants of interest is very similar to the 2006 list of pollutants of
interest. The 2006 and 2007 lists have 10 pollutants in common. Acrylonitrile is new for 2007,
while hexachloro-1,3-butadiene, naphthalene, and hexavalent chromium did not make the list.
As discussed in Section 3.2, there is currently some question about the reliability of the
acetonitrile data. Therefore, acetonitrile results were excluded from the risk screening process
and designation as a pollutant of interest.
Table 4-8 presents the total number of failed screens per site, in descending order, as a
means of comparing the results of the risk screening process across the sites. As shown, S4MO
had the largest number of failed screens (579), followed by TUOK (558) and TOOK (555). In
addition to the number of failed screens, Table 4-8 also shows the total number of screens
conducted (one screen per valid measured detection for each site for all pollutants with screening
values). The failure rate, as a percentage, was determined from the number of failed screens and
the total number of screens conducted (applicable measured detections) and is also provided in
Table 4-8.
Table 4-8. Site-Specific Risk Screening Comparison
Site
S4MO
TUOK
TOOK
TSOK
# of Failed
Screens
579
558
555
535
Total # of
Measured
Detections1
1996
1898
1931
1895
%of
Failed
Screens
29.01
29.40
28.74
28.23
#of
Pollutant
Groups
Analyzed
4
3
3
3
1 Total number of measured detections for all pollutants with screening values, not
just those failing screens.
BOLD = EPA-designated NATTS Site
4-17
-------
Table 4-8. Site-Specific Risk Screening Comparison (Continued)
Site
BTUT
CANJ
SEWA
ELNJ
GPCO
GPMS
SPIL
DEMI
NBIL
NBNJ
LDTN
PXSS
TUMS
CUSD
MSTN
CAMS 35
SFSD
CHNJ
SJPR
ININ
BAPR
IDIN
CNEP
CAMS 85
AZFL
INDEM
ORFL
SYFL
GAFL
WPIN
SKFL
SPAZ
BOMA
SDGA
CELA
RUCA
ITCMI
FLFL
PRRI
ROCH
# of Failed
Screens
499
453
446
437
434
433
432
425
421
397
387
386
370
361
350
318
314
302
225
218
217
210
184
170
120
120
116
116
115
110
102
88
86
39
34
26
23
16
2
1
Total # of
Measured
Detections1
1912
1366
1902
1421
1444
1470
1288
1418
1983
1364
1316
1666
1336
1295
1289
1251
1273
1092
678
767
672
715
1011
862
120
120
116
155
120
112
120
302
634
559
522
432
847
20
37
9
%of
Failed
Screens
26.10
33.16
23.45
30.75
30.06
29.46
33.54
29.97
21.23
29.11
29.41
23.17
27.69
27.88
27.15
25.42
24.67
27.66
33.19
28.42
32.29
29.37
18.20
19.72
100.00
100.00
100.00
74.84
95.83
98.21
85.00
29.14
13.56
6.98
6.51
6.02
2.72
80.00
5.41
11.11
#of
Pollutant
Groups
Analyzed
5
2
4
2
3
3
2
3
5
2
2
5
2
3
2
1
3
2
2
3
2
2
1
1
1
1
1
2
1
1
1
1
2
2
1
1
1
1
1
1
1 Total number of measured detections for all pollutants with screening values, not
just those failing screens.
BOLD = EPA-designated NATTS Site
4-18
-------
Table 4-8. Site-Specific Risk Screening Comparison (Continued)
Site
HAKY
CHSC
MVWI
BXNY
WADC
UNVT
# of Failed
Screens
1
0
0
0
0
0
Total # of
Measured
Detections1
33
17
29
12
33
11
%of
Failed
Screens
3.03
0.00
0.00
0.00
0.00
0.00
#of
Pollutant
Groups
Analyzed
1
1
1
1
1
1
1 Total number of measured detections for all pollutants with screening values, not
just those failing screens.
BOLD = EPA-designated NATTS Site
The number of total screens and the number of pollutants measured by each site must
also be considered when interpreting the results in Table 4-8. For example, sites sampling three,
four, or five pollutant groups tended to have a higher number of failed screens. Yet, AZFL,
INDEM, and ORFL had the highest failure rates (100 percent); however, each of these sites
sampled only one pollutant group (carbonyl compounds). Two pollutants measured with Method
TO-11A have screening values (acetaldehyde and formaldehyde) and these two pollutants tend
to fail all or most of the screens conducted (refer to Table 4-7). Thus, sites sampling only
carbonyls have high failure rates. Conversely, sites that sampled several pollutant groups tended
to have lower failure rates due to the larger number of HAPs screened, as is the case with NBIL,
S4MO, and SEWA. For this reason, the number of pollutant groups for which sampling was
conducted is also presented in Table 4-8. Five sites, UNVT, MVWI, BXNY, CHSC, and
WADC, did not fail any screens. These five sites sampled only hexavalent chromium within the
NATTS program, which limits the number of failed screens possible.
The following sections focus only on those pollutants designated as program-level
pollutants of interest.
4.2.1 Concentrations of the Pollutants of Interest
Concentrations of the program-level pollutants of interest vary significantly, among the
pollutants and among the sites. Tables 4-9 through 4-11 present the top 10 daily average
concentrations and 95 percent confidence intervals by site for each of the pollutants of interest
4-19
-------
(for carbonyls, metals, and VOC, respectively). As discussed in Section 3.3, a daily average is
the average concentration of all measured detections. Please note that not all sites sampled each
pollutant. Certain pollutants, such as the metals, do not have 10 sites listed because less than 10
sites sampled that pollutant group. It is also important to note that the arsenic and manganese
average concentrations in Table 4-10 are reported in ng/m3 for ease of viewing, while Tables 4-9
and 4-11 are reported in ug/m3.
Table 4-9. Daily Average Comparison of the Carbonyl Pollutants of Interest
Rank
1
2
o
J
4
5
6
7
8
9
10
Acetaldehyde
(Ug/m3)
SJPR
6.35
±1.99
ELNJ
5.84
±0.88
DEMI
5.44
±0.89
INDEM
4.56
±0.52
S4MO
4.06
±0.52
PXSS
3.32
±0.42
GPCO
2.79
±0.26
SYFL
2.73
±0.52
LDTN
2.62
±0.42
GAFL
2.54
±0.23
Formaldehyde
(Ug/m3)
INDEM
36.07
±6.34
DEMI
5.76
±0.71
PXSS
4.98
±0.45
ELNJ
4.69
±0.65
S4MO
4.57
±0.68
ININ
4.15
±0.71
WPIN
4.06
±0.58
GPCO
4.02
±0.33
CANJ
3.78
±0.52
LDTN
3.74
±0.64
BOLD = EPA-designated NATTS Site
4-20
-------
Table 4-10. Daily Average Comparison of the Metal Pollutants of Interest
Rank
1
2
3
4
5
6
7
8
Arsenic
(PM10)
(ng/m3)
S4MO
1.83
±1.40
IDIN
1.08
±0.23
BTUT
1.06
±0.44
ININ
0.98
±0.16
NBIL
0.86
±0.15
SEWA
0.76
±0.12
PXSS
0.73
±0.22
BOMA
0.46
±0.05
Arsenic
(TSP)
(ng/m3)
TUOK
2.01
±1.67
TOOK
1.02
±0.21
TSOK
0.91
±0.31
Manganese
(PM10)
(ng/m3)
PXSS
18.82
±2.71
SEWA
12.61
±4.18
S4MO
12.48
±1.73
BTUT
10.08
±1.82
NBIL
7.82
±1.71
ININ
6.18
±1.05
IDIN
5.87
±0.83
BOMA
3.29
±0.34
Manganese
(TSP)
(ng/m3)
TOOK
30.11
±5.70
TUOK
19.76
±3.61
TSOK
17.43
±3.02
BOLD = EPA-designated NATTS Site
4-21
-------
Table 4-11. Daily Average Comparison of the VOC Pollutants of Interest
to
to
Rank
1
2
o
J
4
5
6
7
8
9
10
Acrolein
(Hg/m3)
PXSS
2.27
±0.46
CNEP
1.52
±0.17
SPAZ
1.23
±0.31
TUOK
1.05
±0.19
GPMS
0.91
±0.10
TOOK
0.89
±0.14
TSOK
0.88
±0.16
BAPR
0.87
±0.23
CANJ
0.87
±0.18
S4MO
0.79
±0.12
Acrylonitrile
(Hg/m3)
SPAZ
1.07
±0.27
PXSS
0.86
±0.92
CAMS 35
0.55
±0.29
TOOK
0.33
±0.14
CAMS 85
0.31
±0.01
CUSD
0.28
±0.05
SFSD
0.23
±0.03
GPMS
0.21
±0.04
TUMS
0.21
±0.03
TSOK
0.19
±0.06
Benzene
(Hg/m3)
PXSS
2.06
±0.47
TOOK
2.05
±0.31
SPAZ
2.01
±0.68
CAMS 35
1.59
±0.32
SJPR
1.48
±0.22
GPCO
1.46
±0.20
BTUT
1.29
±0.23
TUOK
1.29
±0.14
CAMS 85
1.15
±0.15
ELNJ
1.09
±0.18
1,3-Butadiene
(Hg/m3)
CAMS 35
0.43
±0.34
PXSS
0.30
±0.08
SPAZ
0.24
±0.10
SJPR
0.17
±0.03
GPCO
0.16
±0.03
ELNJ
0.14
±0.02
SPIL
0.12
±0.02
BAPR
0.12
±0.02
BTUT
0.11
±0.03
DEMI
0.10
±0.02
Carbon
Tetrachloride
(Hg/m3)
SEWA
0.69
±0.04
SPIL
0.69
±0.04
CAMS 35
0.68
±0.04
SJPR
0.68
±0.05
CAMS 85
0.68
±0.04
NBIL
0.66
±0.03
CNEP
0.65
±0.03
DEMI
0.63
±0.03
GPMS
0.62
±0.03
BAPR
0.62
±0.04
/7-Dichlorobenzene
(Hg/m3)
SJPR
0.40
±0.08
PXSS
0.39
±0.08
NBIL
0.33
±0.19
BAPR
0.31
±0.12
SPAZ
0.31
±0.10
S4MO
0.26
±0.10
BTUT
0.25
±0.16
GPMS
0.22
±0.13
CANJ
0.19
±0.03
SPIL
0.15
±0.06
Tetrachloroethylene
(Hg/m3)
PXSS
0.77
±0.25
GPMS
0.62
±0.63
SPIL
0.39
±0.07
SPAZ
0.39
±0.19
TUOK
0.37
±0.10
BTUT
0.34
±0.15
GPCO
0.32
±0.06
ELNJ
0.32
±0.05
DEMI
0.30
±0.07
LDTN
0.29
±0.37
BOLD = EPA-designated NATTS Site.
-------
Some observations from Table 4-9 through 4-11 include the following:
• The highest daily average concentration was calculated for formaldehyde for INDEM
(36.07 ± 6.34 |ig/m3). INDEM's average formaldehyde concentration is significantly
higher than the other nine daily average formaldehyde concentrations.
• PXSS was on the top 10 list for every pollutant it sampled (TSP metals were not
sampled at PXSS) except carbon tetrachloride. In addition, SPAZ, which only
sampled for VOC, appears on seven of the eight VOC top 10 lists.
• All four Oklahoma sites appear on the acrolein top 10 list.
4.2.2 Risk Screening Assessment Using MRLs
A summary of the program-level MRL risk assessment is presented in Table 4-12.
Acrolein and formaldehyde were the only pollutants with at least one exceedance of an ATSDR
risk factor. Out of 1,820 measured detections of formaldehyde, 16 exceeded the ATSDR acute
MRL (50 jug/m3). Fifteen of these exceedances were measured at INDEM; the other exceedance
was measured at SFSD. No measured detections of acrolein exceeded the new ATSDR acute
MRL (7 jug/m3). This is significantly different from 2006, when nearly all acrolein
concentrations exceeded the short-term risk factor. Exceedances of the acute risk factors are
discussed on a site-specific basis in further detail in Sections 5.0 through 31.0.
Out of 123 seasonal averages of formaldehyde, only one seasonal average exceeded the
ATSDR intermediate MRL (40 jug/m3). This seasonal average, calculated for the summer
season, was calculated for INDEM. Conversely, all 99 seasonal averages for acrolein across the
program exceeded the ATSDR intermediate MRL (0.09 jug/m3). Exceedances of the
intermediate risk factors are discussed on a site-specific basis in further detail in Sections 5.0
through 31.0. Graphical displays of the site-specific seasonal averages for the program-level
pollutants of interest are presented and discussed in Section 4.4.2.
Acrolein does not have a chronic risk factor, therefore, chronic risk cannot be evaluated
in this manner. Out of 29 valid annual averages, only one annual average exceeded the ATSDR
chronic MRL for formaldehyde (10 jug/m3). Again, this annual average was calculated for
INDEM. Exceedances of the chronic risk factors are also discussed in further detail on a site-
specific basis in Sections 5.0 through 31.0.
4-23
-------
Table 4-12. Program-Level MRL Risk Assessment Summary
Sampling
Method
TO-11A
TO-15
Pollutant
Formaldehyde
Acrolein
Acute Risk
ATSDR
MRL1
(Hg/m3)
50
7
# of Exceedances/
# of Measured
Detections
16/1820
0/1433
Intermediate Risk
ATSDR
MRL1
(Hg/m3)
40
0.09
#of
Winter
Exceedances/
# of Seasonal
Averages
0/32
25/25
#of
Spring
Exceedances/
# of Seasonal
Averages
0/31
25/25
#of
Summer
Exceedances/
# of Seasonal
Averages
1/30
24/24
#of
Autumn
Exceedances/
# of Seasonal
Averages
0/30
25/25
Chronic Risk
ATSDR
Chronic
MRL1
(Ug/m3)
10
~
#of
Exceedances/
# of Annual
Averages
1/29
~
1 Reflects the use of one significant digit for MRLs
- = an MRL risk factor is not available
to
-------
4.2.3 Correlation Between Concentrations and Meteorological Conditions
Concentrations in ambient air can be significantly influenced by meteorological
conditions. The following three sections describe select meteorological parameters and how
each may affect air quality. Pearson correlation coefficients, which were described in Section
3.4, were calculated between concentration data for the program-level pollutants of interest and
the following meteorological parameters: average maximum daily temperature; average daily
temperature; average daily dew point temperature; average daily wet bulb temperature; average
daily relative humidity; average daily sea level pressure; and average wind speed. Data from the
closest NWS station to each site are used for the correlations. Table 4-13 presents the resulting
correlations.
4.2.3.1 Maximum and Average Temperature
Temperature is often a factor associated with high ambient air concentrations for some
pollutants, such as ozone. Higher temperatures help speed up the kinetic process as pollutants
react with each other. Pearson correlations were calculated between the program-level pollutants
of interest and average maximum daily temperature and average daily temperature.
Table 4-13 shows that the program-level pollutants of interest had fairly weak
correlations with maximum temperature and average temperature. Although the correlations
shown in Table 4-13 are generally low, they are primarily positive, which indicates that an
increase in temperature is generally associated with a proportionate increase in concentration.
The poor correlations exhibited at the program-level are not surprising due to the complex and
diverse local meteorology associated with the monitoring sites. For this report, 50 sites are
spread across 48 states, the District of Columbia, and Puerto Rico. The temperature parameters
correlate better at select individual sites, as discussed in Sections 5.0 through 31.0.
4.2.3.2 Moisture
Three moisture parameters were used in this study for correlation with the pollutants of
interest. The dew point temperature is the temperature to which moist air must be cooled to
reach saturation with respect to water. The wet bulb temperature is the temperature to which
moist air must be cooled by evaporating water into it at constant pressure until saturation is
4-25
-------
Table 4-13. Summary of Pearson Correlations between the Pollutants of Interest and Selected Meteorological Parameters
Pollutant
Acetaldehyde
Acrolein
Acrylonitrile
Arsenic (PM10)
Arsenic (TSP)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
Manganese (PM10)
Manganese (TSP)
Naphthalene
£>-Dichlorobenzene
Tetrachloroethylene
#of
Measured
Detections
1,820
1,433
157
473
173
1,448
1,362
1,446
1,820
473
173
1,150
1,306
1,820
Maximum
Temperature
0.16
0.30
0.26
-0.03
0.10
0.10
0.00
0.19
-0.05
0.27
0.01
0.16
0.08
0.16
Average
Temperature
0.15
0.30
0.27
-0.05
0.06
0.08
-0.01
0.22
-0.04
0.25
-0.05
0.17
0.07
0.15
Dew Point
Temperature
0.10
0.22
-0.02
-0.01
0.06
0.04
-0.02
0.28
-0.03
0.01
-0.19
0.12
0.06
0.10
Wet Bulb
Temperature
0.10
0.24
0.10
-0.04
0.06
0.07
-0.01
0.25
-0.08
0.15
-0.12
0.15
0.07
0.10
Relative
Humidity
-0.18
-0.15
-0.39
0.07
0.04
-0.03
-0.02
0.14
-0.23
-0.35
-0.44
-0.06
-0.01
-0.18
Sea Level
Pressure
-0.21
-0.26
0.03
0.06
0.08
0.13
0.05
-0.06
-0.73
-0.12
0.17
0.05
0.06
-0.21
Scalar
Wind
Speed
-0.16
-0.06
-0.09
-0.17
-0.21
-0.23
-0.06
-0.04
-0.09
-0.26
-0.21
-0.05
-0.11
-0.16
to
-------
reached. The relative humidity is the ratio of the mixing ratio to its saturation value at the same
temperature and pressure (Rogers and Yau, 1989). All three of these parameters provide an
indication of how much moisture is presently in the air. Higher dew point and wet bulb
temperatures indicate increasing amounts of moisture in the air, while relative humidity is
expressed as a percentage with 100 percent indicating saturation. It should be noted that a high
dew point and wet bulb temperature do not necessarily equate to a relative humidity near
100 percent, nor does a relative humidity near 100 percent equate to a relatively high dew point
or wet bulb temperature.
As shown in Table 4-13, the three moisture parameters had weak correlations with the
pollutants of interest. The sites participating in the 2007 programs were located in different
climatic zones ranging from a desert climate (Phoenix, Arizona) to a very moist climate (Florida
and Puerto Rico). The moisture parameters correlate better at select individual sites, as
discussed in Sections 5.0 through 31.0.
4.2.3.3 Wind and Pressure
Wind is an important component affecting air quality. Surface wind observations include
two primary components: wind speed and wind direction. Wind speed, by itself, is a scalar value
and is usually measured in nautical miles or knots (1 knot = 0.5 meters per second =1.15 miles
per hour). Wind direction describes where the wind is coming from, and is measured in degrees
where 0/360E is from the north, 90E is from the east, 180E is from the south, and 270E is from
the west. Wind speed and direction together represent a vector quantity, but in some cases wind
speed can be quantified separately (the scalar value).
As shown in Table 4-13, the scalar wind speed had weak correlations with the pollutants
of interest at the program level, which is consistent with the temperature and moisture parameter
observations. Geographical features such as mountains or valleys influence both wind speed and
wind direction. The sites used for sampling in the 2007 programs are located in different
geographic zones ranging from a mountainous region (Colorado) to a plains region (South
Dakota). Additionally, sites located downwind of emission sources may correlate better with the
measured concentrations than sites upwind. All of the correlations with wind speed are negative,
4-27
-------
however, indicating that as wind speed decreases, concentrations of the pollutants of interest
tend to increase. The scalar wind speed correlates better at select individual sites, as discussed in
Sections 5.0 through 31.0.
Wind is created through changes in pressure. The magnitude of the pressure difference
(or pressure gradient) over an area is directly proportional to the magnitude of the wind speed.
The direction of the wind flow is governed by the direction of the pressure gradient. Sea level
pressure is the local station pressure corrected for elevation, in effect bringing all geographic
locations down to sea-level, thus making different topographical areas comparable. Overall, sea
level pressure correlated weakly with ambient concentrations. However, a strong correlation
was calculated for formaldehyde (-0.73).
4.3 The Impact of Mobile Sources
Ambient air is significantly impacted by mobile sources, as discussed in Section 3.5.1.
Table 4-14 contains several parameters that are used to assess mobile source impact on air
quality near the monitoring sites, including emission data, concentration data, and site-
characterizing data, such as vehicle ownership.
4.3.1 Mobile Source Emissions
On-road emissions come from mobile sources that use roadways such as automobiles,
buses, and construction vehicles; non-road emissions come from the remaining mobile sources
such airplanes, lawn mowers, and boats (EPA, 2008a). Table 4-14 contains county-level on-road
and non-road HAP emissions from the 2002 NEI. Mobile source emissions tended to be highest
in large urban areas and lowest in rural areas. Estimated on-road county emissions were highest
in Los Angeles County, CA, where CELA is located, followed by King County, WA, where
SEWA is located, and Wayne County, MI, where DEMI is located. Estimated non-road county
emissions were also highest in Los Angeles County, CA, followed by Harris County, TX, where
CAMS 35 is located, and Maricopa County, AZ, where SPAZ and PXSS are located. Estimated
on-road and non-road county emissions were lowest in the Barceloneta Municipio, PR, Custer
County, SD, and Hazard County, KY, where BAPR, CUSD, and HAKY are located,
respectively.
4-28
-------
Table 4-14. Summary of Mobile Source Information by Monitoring Site
Site
AZFL
BAPR
BOMA
BTUT
BXNY
CAMS 35
CAMS 85
CANJ
CELA
CHNJ
CHSC
CNEP
CUSD
DEMI
ELNJ
FLFL
GAFL
GPCO
GPMS
HAKY
IDIN
INDEM
ININ
ITCMI
LDTN
MSTN
MVWI
County
Motor
Vehicle
Registration
1,548,528
13,912
467,969
230,868
243,523
3,192,222
67,719
352,413
7,514,916
335,063
42,726
29,398
15,345
1,400,461
359,882
1,541,754
1,203,440
163,539
170,041
47,549
897,388
453,146
897,388
36,768
50,519
50,519
92,255
Estimated
10-Mile
Ownership
957,297
NA
1,040,856
201,584
1,141,304
541,414
3,233
1,374,075
2,825,650
166,661
36,525
21,627
10,891
803,365
1,497,998
1,162,795
487,353
134,661
149,717
51,859
608,497
370,693
684,270
20,596
56,136
56,136
26,067
Annual
Average
Daily
Traffic
37,000
48,400
23,800
17,310
101,475
31,130
2,380
4,633
238,000
18,360
650
5
2,500
20,900
200,000
14,000
41,000
12,300
27,000
21,537
77,250
40,710
97,780
5,200
12,945
7,287
3,500
VMTby
Urban
Area
(thousands)
63,178
NA
94,248
10,373
299,706
97,774
1,688
106,558
279,041
NA
NA
NA
NA
104,126
299,706
132,934
63,178
2,024
6,936
NA
30,572
170,934
30,572
NA
NA
NA
NA
County-Level
On-road
Emissions
(tpy)
4,825.87
7.92
1,132.35
1,063.51
1,397.33
8,667.14
387.96
1,100.36
21,963.19
1,730.09
227.87
267.98
41.94
9,889.36
1,394.87
7,621.94
5,571.31
538.18
856.42
142.23
4,091.14
1,513.09
4,091.14
177.28
361.82
361.82
349.53
County-Level
Non-road
Emissions
(tpy)
1,767.40
39.41
972.11
490.79
858.38
7,151.94
125.44
787.25
8,653.97
1,498.21
95.54
134.46
51.68
2,220.42
883.12
2,765.30
2,198.46
247.77
892.01
22.53
1,210.89
984.22
1,210.89
585.30
239.12
239.12
325.29
Hydrocarbon
Arithmetic
Mean1
(ppbv)
—
3.36
—
4.22
—
5.15
1.50
3.13
—
1.65
—
1.37
1.83
2.90
6.16
~
~
4.64
2.32
—
—
—
—
—
2.00
1.70
~
Acetylene
Arithmetic
Mean1
(ppbv)
—
0.78
—
1.03
—
0.66
0.33
1.01
—
0.42
—
0.53
0.48
1.00
1.20
—
—
1.37
0.52
—
—
—
—
—
0.56
0.50
~
to
VO
lrThis parameter is only available for monitoring sites sampling VOC.
BOLD = EPA-designated NATTS Site
NA = Data not available.
-------
Table 4-14. Summary of Mobile Source Information by Monitoring Site (Continued)
Site
NBIL
NBNJ
ORFL
PRRI
PXSS
ROCH
RUCA
S4MO
SDGA
SEWA
SFSD
SJPR
SKFL
SPAZ
SPIL
SYFL
TOOK
TSOK
TUMS
TUOK
UNVT
WADC
WPIN
County
Motor
Vehicle
Registration
2,104,894
540,949
1,048,589
142,334
3,793,646
552,452
1,344,232
1,136,095
471,264
1,766,228
212,906
145,642
1,548,528
3,793,646
2,104,894
1,203,440
506,011
506,011
71,812
506,011
143,618
219,105
897,388
Estimated
10 Mile
Ownership
346,717
541,057
991,709
151,607
1,478,227
482,248
632,436
688,893
496,466
848,783
203,000
NA
1,166,308
905,994
816,437
288,549
399,376
291,749
64,079
401,033
32,105
693,106
809,471
Annual
Average
Daily
Traffic
35,700
63,326
35,500
212,100
206,000
111,600
17,468
84,821
9,100
232,000
4,265
139,563
48,000
113,000
202,900
30,500
67,092
33,800
12,000
45,300
1,200
36,800
155,900
VMTby
Urban
Area
(thousands)
170,934
299,706
42,448
26,744
77,267
16,038
42,861
63,584
128,353
69,967
2,344
32,364
63,178
77,267
170,934
63,178
20,904
20,904
NA
20,904
3,013
97,009
30,572
County-Level
On-road
Emissions
(tpy)
8,728.23
2,335.59
5,580.22
1,990.93
9,566.18
2,739.09
4,225.82
1,373.22
2,954.13
11,744.97
542.49
490.18
4,825.87
9,566.18
8,728.23
5,571.31
3,474.89
3,474.89
433.93
3,474.89
891.46
1,273.69
4,091.14
County-Level
Non-road
Emissions
(tpy)
5,897.21
1,543.58
2,585.71
789.91
6,054.97
1,095.15
1,799.36
496.29
1,216.56
4,575.81
209.80
259.97
1,767.40
6,054.97
5,897.21
2,198.46
1,480.26
1,480.26
207.08
1,480.26
371.70
601.45
1,210.89
Hydrocarbon
Arithmetic
Mean1
(ppbv)
1.77
1.81
—
—
7.21
—
—
2.57
—
2.29
1.90
7.53
—
7.25
2.50
—
4.92
3.24
1.80
3.63
—
—
~
Acetylene
Arithmetic
Mean1
(ppbv)
0.64
0.66
—
—
1.74
—
—
0.88
—
0.82
0.45
1.07
—
1.55
0.91
—
0.72
0.65
0.52
0.79
—
—
-
-^
o
lrThis parameter is only available for monitoring sites sampling VOC.
BOLD = EPA-designated NATTS Site
NA = Data not available
-------
4.3.2 Hydrocarbon Concentrations
Hydrocarbons are organic compounds that contain only carbon and hydrogen.
Hydrocarbons are derived mostly from crude petroleum sources and are classified according to
the arrangement of atoms, as alicyclic, aliphatic, and aromatic. Hydrocarbons are of prime
economic importance because they encompass the constituents of the major fossil fuels,
petroleum and natural gas, as well as plastics, waxes, and oils. Hydrocarbons in the atmosphere
originate from natural sources and from various anthropogenic sources, such as the combustion
of fuel and biomass, petroleum refining, petrochemical manufacturing, solvent use, and gas and
oil production and use. In urban air pollution, these components, along with oxides of nitrogen
(NOx) and sunlight, contribute to the formation of tropospheric ozone. According to the EPA,
47 percent of hydrocarbon emissions are from mobile sources (both on-road and non-road)
(EPA, 2008e). As such, the concentration of hydrocarbons in ambient air may act as an indicator
of mobile source activity levels. Several hydrocarbons are sampled with Method TO-15,
including benzene, ethylbenzene, and toluene.
Table 4-14 presents the average of the sum of hydrocarbons for each site sampling VOC.
Note that only sites sampling VOC have data in this column. Table 4-14 shows that SJPR,
SPAZ, PXSS, and ELNJ had the highest hydrocarbon averages among the monitoring sites.
Each of these sites is located in a highly populated urban area and in close proximity to heavily
traveled roadways. For example, ELNJ is located near Exit 13 on 1-95. The sites with the
lowest hydrocarbon averages (CNEP, CHNJ, and CAMS 85) are located in fairly rural areas.
The average hydrocarbon concentration can be compared to other indicators of mobile source
activity, such as the ones discussed below, to determine if correlations exist.
4.3.3 Motor Vehicle Ownership
Another indicator of motor vehicle activity near the monitoring sites is the number of
vehicles owned by residents in the county where the monitoring site is located. Actual county-
level vehicle registration data were obtained from the state or local agency, where possible. If
data were not available, vehicle registration data are available at the state-level (EIA, 2007). The
county proportion of the state population was then applied to the state registration count.
4-31
-------
The county-level motor vehicle ownership data and the average of hydrocarbon
concentration are presented in Table 4-14. As previously discussed, SJPR, SPAZ, and PXSS had
the highest average hydrocarbon concentrations, respectively, while CNEP, CAMS 85, and
CHNJ had the least. Table 4-14 also shows that SPAZ, PXSS, CAMS 35, and SPIL had the
highest county-level vehicle ownership of the sites sampling VOC, while BAPR, CUSD, and
CNEP have the least. CELA, which had the highest county-level vehicle ownership of all the
sites, did not sample VOC. A Pearson correlation coefficient can be calculated between these
two data sets. The correlation is 0.47. While this correlation falls below the "strong"
classification, it does indicate a positive correlation between hydrocarbon concentrations and
vehicle registration.
The vehicle ownership at the county-level may not be completely indicative of the
ownership in a particular area. As an illustration, for a county with a large city in the middle of
its boundaries and less populated areas surrounding it, the total county-level ownership may be
more representative of areas inside the city limits than in the rural outskirts. Therefore, a vehicle
registration to population ratio was developed for each county with a monitoring site. Each ratio
was then applied to the 10-mile population surrounding the monitors (from Table 2-1) and is
presented in Table 4-14. Table 4-14 shows that ELNJ, PXSS, and CANJ have the highest
10-mile estimated vehicle ownership of the sites sampling VOC, while CAMS 85, CUSD, and
CNEP have the least. Again, CELA, which had the highest 10-mile vehicle ownership of all the
sites, did not sample VOC. Due to insufficient data availability, a 10-mile vehicle registration
estimate could not be computed for the Puerto Rico sites. The Pearson correlation coefficient
calculated between the average hydrocarbon calculations and the 10-mile vehicle registration
estimate is 0.62. This represents a strong positive correlation, indicating that as vehicle
registration inside the 10-mile radius increases, concentrations of hydrocarbons proportionally
increase.
4-32
-------
Other factors may impact the reliability of motor vehicle ownership data as an indicator
of ambient air monitoring data results:
• Estimates of higher car ownership surrounding a monitoring site do not necessarily
imply increased motor vehicle use in the immediate vicinity of a monitoring site.
Conversely, sparsely populated regions often contain heavily traveled roadways.
• Emission sources in the area other than motor vehicles may significantly affect levels
of hydrocarbons in the ambient air.
4.3.4 Estimated Traffic Volume
In previous UATMP reports, traffic data, which represents the average number of
vehicles passing the monitoring site on a daily basis, was obtained from AQS. However, much
of the populated traffic data reflected traffic conditions during site initiation, and were often five
or more years old. Therefore, updated traffic data was obtained from state and local agencies,
primarily Departments of Transportation. Most of the numbers in this report reflect annual
average daily traffic (AADT), which is "the total volume of traffic on a highway segment for one
year, divided by the number of days in the year," and incorporates both directions of traffic
(FLDOT, 2007). AADT counts obtained were based on data from 2001 to 2007. The updated
traffic values are presented in Table 4-14.
Several limitations exist to obtaining the AADT near each monitoring site. AADT
statistics are developed for roadways managed by different municipalities or government
agencies, such as interstates, state highways, or local roadways. AADT is not always available
in rural areas or for secondary roadways. For monitoring sites located near interstates, the
AADT for the interstate segment closest to the site was obtained. For other monitoring sites, the
highway or secondary road closest to the monitoring site was used. Only one AADT value was
obtained for each monitoring site, which is different from the approach for previous UATMP
reports. The intersection or roadway chosen for each monitoring site is discussed in each state
section.
Table 4-14 shows that SEW A, PXSS, and SPIL have the highest daily traffic volume of
the sites sampling VOC, while CAMS 85, CUSD, and CNEP have the lowest. Of all the
monitoring sites, the highest daily traffic volume occurs near CELA, SEW A, and PRRI. CELA
4-33
-------
is located in downtown Los Angeles; SEWA is located in Seattle near the intersection of 1-5 and
1-9; and PRRI is located near 1-95 just south of Providence. The average hydrocarbon
concentration at SEWA was 2.29 ppbv, which ranked 17th among sites that measured VOC.
CELA and PRRI did not measure VOC. A Pearson correlation coefficient calculated between
the average hydrocarbon calculations and the traffic counts is 0.51. This represents a strong
positive correlation, indicating that as traffic volume increases, concentrations of hydrocarbons
proportionally increase. Previous reports showed very little correlation between these two
parameters, supporting the recommendation to update the traffic values, both in the report and in
AQS.
4.3.5 Vehicle Miles Traveled
Another approach to determining how mobile sources affect urban air quality is to review
OK vehicle miles traveled (VMT). This approach was not included in previous UATMP reports.
VMT is the sum of distances traveled by all motor vehicles in a specified system of
highways for a given period of time (ODOT, 2007). As such, VMT values tend to be rather
large (in the millions). County-level data is not available for all states. However, daily VMT
data are available from the Federal Highway Administration (FHWA) by urban area (FHWA,
2006). The MSA designations are used to designate in which urban area each monitoring site
resides. For example, CAMS 35 is located in Deer Park, Texas. This city is located near
Houston and is part of the Houston-Galveston-Brazoria, TX MSA. Therefore, VMT for CAMS
35 is for the value reported for Houston. VMT are presented in Table 4-14, where available.
The urban areas with UATMP or NATTS sites with the highest VMT are New York, Los
Angeles, and Chicago. A Pearson correlation coefficient calculated between the average
hydrocarbon calculations and VMT is almost zero (-0.02), indicating virtually no relationship
between the two. However, many of the sites with the largest VMT did not measure VOC (such
as CELA, RUCA, BXNY, and INDEM). In addition, VMT was not available for sites not in
"urban areas," as defined by the FHWA. Seven sites that measured VOC (almost one-third) are
not in urban areas.
4-34
-------
4.3.6 Mobile Source Tracer Analysis
Research has shown that acetylene can be used as a signature compound (or tracer) for
automotive emissions (Warneck, 1988; NRC, 1991) because this VOC is not typically emitted
from biogenic or stationary sources. Table 4-14 presents average acetylene concentrations for
each monitoring site that sampled VOC. As shown, PXSS, SPAZ, and GPCO have the highest
average acetylene concentrations, respectively.
Pearson correlation coefficients were calculated between the average acetylene
concentrations and each of the parameters discussed above (vehicle ownership, traffic data, and
VMT). The Pearson correlations were generally stronger for the average acetylene
concentrations than for the average hydrocarbon concentrations:
• Between county-level vehicle ownership and acetylene: 0.56
• Between 10-mile vehicle ownership and acetylene: 0.72
• Between traffic volume and acetylene: 0.57
• Between VMT and acetylene: 0.12.
Nearly all emissions of ethylene are due to automotive sources, with the exception of
activities related to natural gas production and transmission. Ethylene is not detected as a VOC
by the TO-15 sampling method, but is detected using the SNMOC method. According to tunnel
studies, an ethylene to acetylene ratio of 1.7 to 1 is indicative of mobile sources (TCEQ, 2002).
For the five sites that chose the SNMOC option, ethylene to acetylene concentration ratios were
computed and compared to the 1.7 to 1 ratio in Table 4-15.
All of the calculated ratios are less than the expected ratio of 1.7. This indicates that
there is likely an ethylene sink or an acetylene source affecting the concentrations of these
pollutants. Of the sites that sampled SNMOC, NBIL=s ethylene to acetylene ratio was the
closest to the expected 1.7 ratio (1.52), while SFSD's ratio was least like the expected ratio
(1.24). These results are very similar to those in the 2006 UATMP report.
4-35
-------
Table 4-15. Average Ethylene-to-Acetylene
Ratios for Sites that Measured SNMOC
Site
BTUT
CUSD
GPMS
NBIL
SFSD
Average Ethylene to
Acetylene Ratio
1.29
1.33
1.42
1.52
1.24
% Difference from
1.70 Ratio
-24.14
-22.01
-16.73
-10.65
-27.15
BOLD = EPA-designated NATTS Site.
4.3.7 BTEX Concentration Profiles
The magnitude of emissions from motor vehicles generally depends on the volume of
traffic in urban areas, but the composition of these emissions depends more on vehicle design.
Because the distribution of vehicle designs (i.e., the relative number of motor vehicles of
different styles) is probably quite similar from one urban area to the next, the composition of air
pollution resulting from motor vehicle emissions is not expected to exhibit significant spatial
variations. In support of this hypothesis, previous air monitoring studies have observed
relatively constant composition of ambient air samples collected along heavily traveled urban
roadways (Conner et al., 1995). Roadside studies have found particularly consistent proportions
of four hydrocarbons (benzene, toluene, ethylbenzene, and the xylene isomers - the ABTEX@
compounds) both in motor vehicle exhaust and in ambient air near roadways.
To examine the impact of motor vehicle emissions on air quality at the 2007 UATMP and
NATTS monitoring sites, Table 4-16 and Figure 4-1 compare average concentration ratios for
the BTEX compounds measured during the 2007 program year to the ratios reported in the
roadside study. Table 4-16 contains the 95 percent confidence interval for each average BTEX
ratio. This comparison provides a qualitative depiction of how greatly motor vehicle emissions
affect air quality at the UATMP and NATTS monitoring sites: the more similar the concentration
ratios at a particular monitoring site are to those of the roadside study, the more likely that motor
vehicle emissions impact ambient levels of hydrocarbons at that location.
4-36
-------
Table 4-16. Comparison of Concentration Ratios for BTEX Compounds
vs. Roadside Study
Site
Roadside Study
BAPR
BTUT
CAMS 35
CAMS 85
CANJ
CHNJ
CNEP
CUSD
DEMI
ELNJ
GPCO
GPMS
LDTN
MSTN
NBIL
NBNJ
PXSS
S4MO
SEWA
SFSD
SJPR
SPAZ
SPIL
TOOK
TSOK
TUMS
TUOK
Benzene-
Ethylbenzene Ratio
2.85
3. 17 ±0.40
4.59 ±0.36
7.26 ±0.82
18.13 ±2.06
4.88 ±0.42
6.57 ±1.19
8.05 ± 0.93
7.87 ±1.00
5. 16 ±0.56
3.94 ±0.32
3.37 ±0.24
3.24 ±0.34
6.69 ±0.67
7.87 ± 1.09
5.26 ± 0.67
4.62 ±0.55
3.35 ±0.41
3.91 ±0.37
4.51 ±0.32
5. 85 ±0.86
1.45 ±0.22
2. 12 ±0.67
5. 13 ±0.46
5. 14 ±0.58
3.65 ±0.38
5.75 ±0.67
4.78 ±0.35
Toluene-
Ethylbenzene Ratio
5.85
9.35 ±3. 18
15.44 ±10.21
8.97 ± 1.46
10.56 ±0.89
7.65 ±0.77
44.53 ± 52.46
7.65 ±0.99
8.00 ±0.94
6.91 ±0.48
7.67 ±1.40
8.27 ± 1.98
6.94 ±0.97
8.14 ±1.06
9.75 ± 1.22
7.76 ±0.83
6.80 ±0.34
11.79 ±1.87
6.82 ±0.68
6.75 ±0.22
21.37 ±5.00
8.06 ±0.80
5.45 ±0.82
6.71 ±0.41
12.69 ±2.28
14.33 ±3.20
10.45 ±1.69
12.44 ±1.72
Xylenes-
Ethylbenzene Ratio
4.55
3.88 ±0.13
4.22 ±0.17
3.10±0.14
3.48 ±0.17
3.59 ±0.09
3.02 ±0.19
2.89 ±0.14
3.32 ±0.16
3.59 ±0.10
3. 54 ±0.08
4.46 ± 0.07
3. 33 ±0.15
3.42 ±0.20
3.26 ±0.09
3.26 ±0.13
3. 31 ±0.08
3.62 ±0.11
3. 12 ±0.08
3. 80 ±0.09
2.89 ±0.19
4.20 ±0.08
3.97 ±0.21
3.33±0.11
4.15±0.10
3.51 ±0.23
3.52±0.11
3.99±0.11
BOLD = EPA-designated NATTS Site.
4-37
-------
Figure 4-1. Comparison of Concentration Ratios for BTEX Compounds vs. Roadside Study
-^
oo
Actual CHNJ toluene-
ethylbenzene ratio is 44.53
-rft
Roadside
Study
BAPR BTUT CAMS 35 CAMS 85 CANJ
Monitoring Site
CHNJ
CNEP CUSD
DEMI
DBenzene-Ethylbenzene Ratio •Toluene-Ethylbenzene Ratio DXylenes-Ethylbenzene Ratio
-------
-^
VO
Figure 4-1. Comparison of Concentration Ratios for BTEX Compounds vs. Roadside Study (Continued)
Roadside
Study
ELNJ
GPCO
GPMS
LDTN
MSTN
NBIL
NBNJ
PXSS
S4MO
Monitoring Site
DBenzene-Ethylbenzene Ratio •Toluene-Ethylbenzene Ratio DXylenes-Ethylbenzene Ratio
-------
-^
o
Figure 4-1. Comparison of Concentration Ratios for BTEX Compounds vs. Roadside Study (Continued)
Roadside
Study
SEWA
SFSD
SJPR
SPAZ
SPIL
TOOK
TSOK
TUMS
TUOK
Monitoring Site
DBenzene-Ethylbenzene Ratio •Toluene-Ethylbenzene Ratio DXylenes-Ethylbenzene Ratio
-------
As presented in Figure 4-1, the concentration ratios for BTEX compounds measured at
most of the monitoring sites bear some resemblance to the ratios reported in the roadside study.
The BTEX ratios at the BAPR and GPCO monitoring sites appear to be the most similar to the
roadside study profile. For all monitoring sites, the toluene-ethylbenzene ratio is the largest of
the three ratios, with the exceptions of CAMS 85 and CNEP. The benzene-ethylbenzene ratio is
the smallest of the three ratios at six sites, while the xylenes-ethylbenzene ratio is the smallest at
21 sites. These observations suggest that emissions from motor vehicles have an impact on the
levels of hydrocarbons in urban ambient air, although they are not the only contributing factor.
4.4 Variability Analysis
This section presents the results of the two variability analyses described in Section 3.5.2.
4.4.1 Coefficient of Variation
Figures 4-2 through 4-12 are graphical displays of site-specific coefficient of variations
(standard deviation versus average concentration). The figures show that several of the
compounds appear to exhibit the "clustering" discussed in Section 3.5.2. Formaldehyde appears
to exhibit clustering in Figure 4-9; however, the data point representing INDEM's average and
standard deviation is significantly higher than the others. INDEM resides in a heavily
industrialized area, and this may be the result of emissions from nearby petroleum refinery and
steel manufacturing facilities. If this data point was removed and the scales adjusted, the
formaldehyde concentrations would show more variability. This example demonstrates that the
range of concentrations must be considered when interpreting the graphs.
Carbon tetrachloride and 1,3-butadiene exhibit clustering, or uniformity in
concentrations. Carbon tetrachloride is a pollutant that was used world wide as a refrigerant.
However, it was identified as an ozone-depleting substance in the stratosphere and its use was
banned at the Kyoto Accords. This pollutant has a long lifetime in the atmosphere, but slowly
degrades over time. Since being banned, its concentration in ambient air is fairly ubiquitous
regardless of where it is measured. The compressed range of associated coefficients of
variations shown in Figure 4-8 not only supports this expected uniformity (i.e., lack of
4-41
-------
1.4
1.2
Figure 4-2. Coefficient of Variation Analysis of 1,3-Butadiene Across 27 Sites
-^
to
o
0)
Q
"E
TO
w
0.4
0.2
0.2
0.4
0.6
0.8
1.2
1.4
Average Concentration (|jg/m )
-------
Figure 4-3. Coefficient of Variation Analysis of Acetaldehyde Across 33 Sites
Average Concentration ([iglm )
-------
Figure 4-4. Coefficient of Variation Analysis of Acrolein Across 27 Sites
2.5 n
I 1-5
+j
.2
0)
Q
"E
TO
•o
I 1
0.5
1
1.5
2.5
Average Concentration (|jg/m )
-------
1.5 T
1.25
Figure 4-5. Coefficient of Variation Analysis of Acrylonitrile Across 27 Sites
.2
0)
Q
"E
TO
•o
I
w
0.75
0.5
0.25
0.25
0.5 0.75
Average Concentration (|jg/m3)
1.25
1.5
-------
Figure 4-6. Coefficient of Variation Analysis of Arsenic Across 11 Sites
O
i 4
0)
0
"E
TO
CO
Average Concentration (ng/m )
PM10 • TSP Linear (PM10) Linear (TSP)
-------
Figure 4-7. Coefficient of Variation Analysis of Benzene Across 27 Sites
0.5
1
1.5
2.5
Average Concentration (|jg/m )
-------
0.8
Figure 4-8. Coefficient of Variation Analysis of Carbon Tetrachloride Across 27 Sites
-^
oo
0.6
.2
0)
Q
"E
TO
•o
I
w
0.4
0.2
0.2
0.4
0.6
0.8
Average Concentration (|jg/m )
-------
Figure 4-9. Coefficient of Variation Analysis of Formaldehyde Across 33 Sites
10
15
20
25
30
35
40
Average Concentration (|jg/m )
-------
35 T-
30
Figure 4-10. Coefficient of Variation Analysis of Manganese Across 11 Sites
25
-j^
o
o
'•§ 20
10
10
15
20
Average Concentration (ng/m )
25
PM10 • TSP Linear (PM10) Linear (TSP)
30
35
-------
Figure 4-11. Coefficient of Variation Analysis of/J-Dichlorobenzene Across 27 Sites
0.8
I °'6
'^
.2
0)
Q
"E
TO
•o
I 0.4
0.2
0.2
0.4
0.6
0.8
Average Concentration ([iglm )
-------
Figure 4-12. Coefficient of Variation Analysis of Tetrachloroethylene Across 27 Sites
2.5 n
-^
to
11-5
+J
.2
0)
Q
"E
TO
•o
I 1
0.5
0.5
1
1.5
2.5
Average Concentration (|jg/m )
-------
variability) in "background" concentrations of carbon tetrachloride, but is also a testament to the
representativeness of the data produced under the EPA National Monitoring Programs.
Although many of the other pollutants do not exhibit easily classifiable clustering, or
even appear to follow a linear pattern, many of them are thrown off by one or two data points
that do not fall in line with the others. For example, the larger standard deviations exhibited for
tetrachloroethylene indicate that these averages were influenced by outliers. Excluding this data
point would allow the rest to follow a linear trend line.
4.4.2 Seasonal Variability Analysis
Figures 4-13 through 4-25 provide a graphical display of the average concentrations by
season for the program-level pollutants of interest. Seasonal averages are calculated based on
criteria specified in Section 3.3. If the pollutant of interest has a corresponding ATSDR
Intermediate MRL, then this value is indicated on the graph and is plotted where applicable.
Some of the program-wide pollutants of interest, such as/>-dichlorobenzene, were
measured frequently in some seasons but not in others. As a result of the seasonal average
criteria, there are gaps in the figures for these pollutants for certain seasons. For example,
Figure 4-24 shows that/>-dichlorobenzene had fewer winter averages, even though many of the
sites sampled year-round. Figure 4-16 for acrylonitrile has only spring and summer averages for
only three sites. This indicates that this pollutant is infrequently detected. But given its
pollutant of interest classification, most detects failed the screening process. The start and stop
dates of each site must be considered when interpreting the seasonal graphs.
Some pollutants of interest, such as formaldehyde, benzene, and acetaldehyde, were
detected year-round. Comparing the seasonal averages for the sites with four valid seasonal
averages often reveals a trend for these pollutants. For example, formaldehyde averages tended
to be higher in the summer, as shown in Figure 4-21, while 1,3-butadiene and benzene averages
tended to be higher in the autumn and winter, as shown in Figure 4-13 and Figure 4-19. The
seasonal behavior of benzene and formaldehyde suggests the influence of reformulated gasoline
(RFG), as the benzene content is typically lowered during the warmer periods (i.e., summer and
4-53
-------
Figure 4-13. Comparison of Average Seasonal 1,3-Butadiene Concentrations by Season
0.9
0.8
rf-0.7
"3)
1,3-Butadiene has no AT SDR Intermediate MRL
0.6
o
'•§
u
o
o
a) 0.4
O)
2
0)
< 0.3
BAPR BTUT CAMS CAMS CANJ CHNJ CNEP CUSD DEMI ELNJ GPCO GPMS LDTN MSTN
35 85
Monitoring Site
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-13. Comparison of Average Seasonal 1,3-Butadiene Concentrations by Season (Continued)
1
n Q
n R
0 7
"3)
"* n K
ntration
D C
Jl C
fl) v-^
U
Ǥ
2
0)
< 03
n 9
n 1
n
r-i
^^1 1 1 ^^1
Ctd LLhil
1,3-Butadiene has no ATSDR Intermediate MRL
HnH Hi ^n nJl
n_r -i- n^-n n-
H n ~ n— i n
In Rm\\] \ \ n 1
NBIL NBNJ PXSS S4MO SEWA
SFSD SJPR SPAZ
Monitoring Site
SPIL TOOK TSOK TUMS TUOK
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-14. Comparison of Average Seasonal Acetaldehyde Concentrations by Season
1 U
Q
7 _
1
"3)
.0
1
"£ K
0) °
u
Ǥ
Q) 4
0)
2
0)
< 3
0
•1
n
Acetaldehyde has no AT SDR
-i
-
p
-
_
r-i
p.
u
-
PI
-
-
-
-
_
-
-
Intermediate MRL
-
-
-
-
-
p
-i
p
pi
1
-
-
_
p
pi
i-T
AZFL BAPR BTUT CANJ CHNJ CUSD DEMI ELNJ FLFL GAFL GPCO GPMS IDIN INDEM ININ LDTN MSTN
Monitoring Site
D Winter
I Spring
D Summer
D Autumn
-------
10
Figure 4-14. Comparison of Average Seasonal Acetaldehyde Concentrations by Season (Continued)
Acetaldehyde has no AT SDR Intermediate MRL
"I 7
"3)
t 6
o
u
Ǥ
a>
ro
2
0)
jr
NBIL NBNJ ORFL PXSS S4MO SEWA SFSD SJPR SKFL SPIL SYFL TOOK TSOK TUMS TUOK WPIN
Monitoring Site
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-15. Comparison of Average Seasonal Acrolein Concentrations by Season
T _
9 5
CO
*s
O 9
2
+-
0)
u
c
-^ 0 1 5 _
i Q l .0
U\ fl)
oo o)
2
0)
< !
Oc
n
-,
r-
:
^_^
r-
—
—
r-i
-
-
-
-
ATSDR Intermediate MRL for acrolein = 0.09 ug/m3
~i H~ ~i ~i ri-i
.— r~
_. — |
f (I
"1
BAPR BTUT CAMS CAMS CANJ CHNJ CNEP CUSD
35 85
Monitoring Site
DEMI
ELNJ GPCO GPMS LDTN MSTN
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-15. Comparison of Average Seasonal Acrolein Concentrations by Season (Continued)
3.5
3
2.5
ATSDR Intermediate MRL for acrolein = 0.09
E
"3)
I 2
0)
u
O 1.5
o>
01
£
a>
0.5
NBIL NBNJ PXSS S4MO SEWA
SFSD SJPR SPAZ
Monitoring Site
SPIL TOOK TSOK TUMS TUOK
D Winter
I Spring
D Summer
D Autumn
-------
-^
o
Figure 4-16. Comparison of Average Seasonal Acrylonitrile Concentrations by Season
0.25
0.2
"3)
0.15
0)
o
o
o
a) 0.1
O)
2
0)
0.05
Acrylonitrile has no AT SDR Intermediate MRL
BAPR BTUT CAMS CAMS CANJ CHNJ CNEP CUSD DEMI ELNJ GPCO GPMS LDTN MSTN
35 85
Monitoring Site
D Winter
I Spring
DSummer
D Autumn
-------
Figure 4-16. Comparison of Average Seasonal Acrylonitrile Concentrations by Season (Continued)
0.25
0.2
Acrylonitrile has no AT SDR Intermediate MRL
E
"3)
0.15
0)
u
Ǥ
a) 0.1
O)
£
0)
0.05
NBIL NBNJ PXSS S4MO SEWA
SFSD SJPR SPAZ
Monitoring Site
SPIL TOOK TSOK TUMS TUOK
D Winter
I Spring
DSummer
D Autumn
-------
Figure 4-17. Comparison of Average Seasonal Arsenic PMio Concentrations by Season
-^
to
4.5
3.5
E
"3)
"
+-
0)
u
§ 2
o
0)
O)
1.5
0.5
BOMA
Arsenic has no AT SDR Intermediate MRL
BTUT
IDIN
ININ NBIL
Monitoring Site
PXSS
S4MO
SEWA
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-18. Comparison of Average Seasonal Arsenic TSP Concentrations by Season
£ 4
"3)
o
C -5
0) J
o
o
o
a)
O)
2
g 2
Arsenic has no AT SDR Intermediate MRL
TOOK
TSOK
Monitoring Site
TUOK
D Winter
Spring
D Summer
D Autumn
-------
3.5
Figure 4-19. Comparison of Average Seasonal Benzene Concentrations by Season
3
_ 2.5
CO
"3)
I 2
a)
u
<§ 1.5
0)
O)
2
0)
AT SDR Intermediate MRL for benzene = 20 (ig/m
0.5
BAPR BTUT CAMS CAMS CANJ CHNJ CNEP CUSD DEMI ELNJ GPCO GPMS LDTN MSTN
35 85
Monitoring Site
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-19. Comparison of Average Seasonal Benzene Concentrations by Season (Continued)
3.5
3
2.5
AT SDR Intermediate MRL for benzene = 20 ug/rn
E
"3)
I 2
0)
u
O 1.5
o>
01
£
a>
0.5
NBIL NBNJ PXSS S4MO SEWA
SFSD SJPR SPAZ
Monitoring Site
SPIL TOOK TSOK TUMS TUOK
D Winter
I Spring
D Summer
D Autumn
-------
Oi
1.25
"3)
0.75
a)
u
o
o
a) 0.5
O)
2
0)
0.25
Figure 4-20. Comparison of Average Seasonal Carbon Tetrachloride Concentrations by Season
AT SDR Intermediate MRL for carbon tetrachloride = 200 j-ig/m
BAPR BTUT CAMS CAMS CANJ CHNJ CNEP CUSD DEMI ELNJ GPCO GPMS LDTN MSTN
35 85
Monitoring Site
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-20. Comparison of Average Seasonal Carbon Tetrachloride Concentrations by Season (Continued)
1.25
AT SDR Intermediate MRL for carbon tetrachloride = 200 j-ig/m
E
"3)
0.75
0)
u
Ǥ
a) 0.5
ro
£
0)
0.25
[fl
NBIL
NBNJ
PXSS S4MO SEWA
SFSD SJPR SPAZ
Monitoring Site
SPIL
TOOK TSOK TUMS TUOK
D Winter
I Spring
DSummer
D Autumn
-------
-^
oo
Figure 4-21. Comparison of Average Seasonal Formaldehyde Concentrations by Season
50
45
40
~ 35
)
30
u
Ǥ
a) 20
ro
2
0)
< 15
10
AT SDR Intermediate MRL for formaldehyde = 40
Actual INDEM summer concentration = 64.23 (ug/m3)
.n rrlrfll
I
n
JH
AZFL BAPR BTUT CANJ CHNJ CUSD DEMI ELNJ FLFL GAFL GPCO GPMS IDIN INDEM ININ LDTN MSTN
Monitoring Site
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-21. Comparison of Average Seasonal Formaldehyde Concentrations by Season (Continued)
50
45
40
~ 35
AT SDR Intermediate MRL for formaldehyde = 40
)
30
u
Ǥ
a) 20
ro
2
0)
< 15
10
n-n-i
n-ITl
Ulrfldlh
Iff]
NBIL NBNJ ORFL PXSS S4MO SEWA SFSD SJPR SKFL SPIL SYFL TOOK TSOK TUMS TUOK WPIN
Monitoring Site
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-22. Comparison of Average Seasonal Manganese PMio Concentrations by Season
-^
o
50
45
40
~ 35
CO
*s
fso
o
'1
+J
s ?z
a) ^a
o
o
O
a) 20
O)
2
o
< 15
10
Manganese has no ATSDR Intermediate MRL
BOMA
BTUT
IDIN
ININ NBIL
Monitoring Site
PXSS
S4MO
SEWA
D Winter
I Spring
DSummer
D Autumn
-------
Figure 4-23. Comparison of Average Seasonal Manganese TSP Concentrations by Season
50
45
40
~ 35
CO
"3)
~ 30
I
+-
s ?z
0 ^a
o
o
O
a) 20
O)
2
a)
< 15
10
5
Manganese has no AT SDR Intermediate MRL
TOOK
TSOK
Monitoring Site
TUOK
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-24. Comparison of Average Seasonal /7-Dichlorobenzene Concentrations by Season
-^
to
0.6
0.5
E 0.4
O)
o
0) u.o
U
O
o
0)
O)
2
0.2
0.1
AT SDR Intermediate MRL forp -dichlorobenzene = 1000 (ig/m
ttfll
BAPR BTUT CAMS CAMS CANJ CHNJ CNEP CUSD DEMI
35 85
Monitoring Site
ELNJ GPCO GPMS LDTN MSTN
D Winter
I Spring
D Summer
D Autumn
-------
Figure 4-24. Comparison of Average Seasonal /7-Dichlorobenzene Concentrations by Season (Continued)
0.6
0.5
AT SDR Intermediate MRL for/) -dichlorobenzene = 1000
E 0.4
"3)
o
§ 0.3
u
o
o
o
0.2
0.1
11
rrfl m
NBIL NBNJ PXSS S4MO SEWA
SFSD SJPR SPAZ
Monitoring Site
SPIL TOOK TSOK TUMS TUOK
D Winter
1 Spring
D Summer
D Autumn
-------
Figure 4-25. Comparison of Average Seasonal Tetrachloroethylene Concentrations by Season
1.8
1.6
1.4
E 1.2
01
1 <
+j
0)
u
§0.8
Tetrachloroethylene has no AT SDR Intermediate MRL
O)
0.6
0.4
0.2
m
rrm HI
BAPR BTUT CAMS CAMS CANJ CHNJ CNEP CUSD DEMI
35 85
Monitoring Site
ELNJ GPCO GPMS LDTN MSTN
D Winter
1 Spring
D Summer
D Autumn
-------
Figure 4-25. Comparison of Average Seasonal Tetrachloroethylene Concentrations by Season (Continued)
1.8
1.6
1.4
jE 1.2
"3)
1 '
+J
0)
Tetrachloroethylene has no AT SDR Intermediate MRL
0.8
a)
01
0.6
0.4
0.2
I
NBIL NBNJ PXSS S4MO SEWA
SFSD SJPR SPAZ
Monitoring Site
SPIL TOOK TSOK TUMS TUOK
D Winter
I Spring
D Summer
D Autumn
-------
spring). Refineries typically begin production of RFG during the spring and end in the autumn.
Additionally, methyl-fert-butyl ether (MTBE) is often used as an RFG additive in fuels to
replace the lowered benzene content. Research has shown that the combustion of fuels
containing MTBE leads to the secondary production of formaldehyde. Thus, while benzene
concentrations decrease during the summer months, formaldehyde concentrations may increase
if MTBE is used in the gasoline blend. Other pollutants may not exhibit such a trend.
The seasonal average comparison also allows for the identification of sites with unusually
high concentrations of the pollutants of interest compared to other sites and when those high
concentrations were measured. For example, Figure 4-23 shows that INDEM's formaldehyde
concentrations are significantly higher than other sites, and that they are elevated year-round.
4.5 Greenhouse Gases
Table 4-17 presents the program-level daily average concentration of the ten GHGs
measured by Method TO-15, in descending order by GWP. As shown, each of the GHGs is
detected in nearly every sample collected (there were a total 1448 VOC samples collected). The
one exception is chloroform, although it was detected in over 85 percent of samples.
Dichlorodifluoromethane has the highest GWP, as well as the highest program-level daily
average. Dichlorodifluoromethane's GWP (10,600) is almost twice the next highest GWP, and
its program-level daily average (2.65 ± 0.05 |ig/m3) is an order of magnitude higher than most of
the other GHGs. Bromomethane has both the lowest GWP (5) and the lowest program-level
daily average (0.07 ± 0.01 jig/m3).
Table 4-17. Greenhouse Gases
Pollutant
Dichlorodifluoromethane
Trichlorotrifluoroethane
Trichlorofluoromethane
Global
Warming
Potential
(100 yrs)
10,600
6,000
4,600
#of
Measured
Detections
1,447
1,447
1,440
Program
Daily Average
(Mg/m3)
2.65
±0.05
0.80
±0.04
1.55
±0.05
4-76
-------
Table 4-17. Greenhouse Gases (Continued)
Pollutant
Carbon Tetrachloride
Dichlorotetrafluoroethane
1,1,1 -Trichloroethane
Chloroform
Chloromethane
Dichloromethane
Bromomethane
Global
Warming
Potential
(100 yrs)
1,800
1,800
1,400
30
16
10
5
#of
Measured
Detections
1,446
1,445
1,447
1,241
1,446
1,445
1,415
Program
Daily Average
(Mg/m3)
0.60
±0.01
0.13
±0.01
0.11
±0.01
0.24
±0.03
1.24
±0.02
0.77
±0.36
0.07
±0.01
4-77
-------
5.0 Sites in Arizona
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS and UATMP sites in Arizona, and integrates these
concentrations with emissions, meteorological, and risk information.
5.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. The Arizona sites are
located in the Phoenix-Mesa-Scottsdale, AZ MSA. PXSS is located in central Phoenix and
SPAZ is located further south. Figures 5-1 and 5-2 are composite satellite images retrieved from
Google™ Maps showing the monitoring sites in their urban locations. Figure 5-3 identifies point
source emission locations within 10 miles of each site as reported in the 2002 NEI for point
sources. Table 5-1 describes the area surrounding each monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
Figure 5-1 shows that PXSS is located in a highly residential area on North 17th Avenue
in central Phoenix. The site is approximately three quarters of a mile east of 1-17 and two miles
north of 1-10. SPAZ is located in South Phoenix. Figure 5-2 shows that SPAZ is located to the
southeast of Hay den Park and is surrounded on the west side by residential properties, and
commercial properties to the east. SPAZ is located approximately one mile south of 1-17.
As Figure 5-3 shows, SPAZ and PXSS are located within 10 miles of each other. The
majority of emission sources are located to the south of PXSS and north of SPAZ. Fewer point
sources are located within a mile or two of PXSS than SPAZ. Facilities engaged in fuel
combustion processes are the most numerous sources near these monitoring sites. The emission
sources nearest PXSS primarily reflect the manufacture of industrial machinery; the manufacture
of stone, clay, and concrete products; and processes involving fuel combustion. Facilities
engaged in surface coating processes are the point sources closest to SPAZ.
5-1
-------
Figure 5-1. Phoenix, Arizona (PXSS) Monitoring Site
©2008 Google/ONAVTECH
Scale 3cm = 100m
-------
Figure 5-2. South Phoenix, Arizona (SPAZ) Monitoring Site
•••- •-- ""
/.Corena'Avs;
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 5-3. NEI Point Sources Located Within 10 Miles of PXSS and SPAZ
• .
itynirw in-
Mote DIM to fftdlly d**i*Hj *nd cotoctfton tht 1rtil **c*M*«
d may rid rtfireawil at 1ncilfli«% AIHMI Hi* w*a ol merest
Legend
•& PXSS NATTS sile * SPAZ UATMP sile
Source Category Group (No. of Facilities)
c Chemicals & Allied Products Facility (3)
2 Electrical 8 Electronic Equipment Facility (5)
D Fabricated M
-------
Table 5-1. Geographical Information for the Arizona Monitoring Sites
Site
Code
PXSS
SPAZ
AQS Code
04-013-9997
04-013-4003
Location
Phoenix
Phoenix
County
Maricopa
Maricopa
]Micro- or
Metropolitan
Statistical Area
Phoenix-Mesa-
Scottsdale, AZ
Metropolitan
Statistical Area
Phoenix-Mesa-
Scottsdale, AZ
Metropolitan
Statistical Area
Latitude
and
Longitude
33.503667,
-112.095139
33.40316,
-112.07533
Land Use
Residential
Residential
Location
Setting
Urban/City
Center
Urban/City
Center
Description of the
Immediate Surroundings
The JLG Supersite (Phoenix) was established by the
Arizona Department of Environmental Quality
(ADEQ) to represent air quality in the central core of
the Phoenix metropolitan area. The site was
designated a PAMS site in 1999. In 2007, ADEQ
operated an automated GC/MS monitoring system for
PAMS data collection. Monitors operated during the
ozone season (April through October) included trace
level oxides of nitrogen (NOn,), total reactive oxides
of nitrogen (NOy), multi-canister samplers for VOCs,
and multiport carbonyl samplers. Monitors operated
year round include toxics and carbonyls samplers, CO,
O3, SO2, NOX, wind speed and direction, temperature,
relative humidity, visibility equipment, PM10, PM25,
CSN sampler, and aethalometer (black carbon). The
area surrounding the site is primarily residential
neighborhoods. An interstate highway is located
approximately one mile west of the site. Commercial
and industrial areas are within five miles of the site.
Maricopa County Air Quality Department established
the South Phoenix site at its current location in 1999
and operates the CO, O3, PM10, and PM25 monitors
located there. Arizona Department of Environmental
Quality operates the air toxics monitors located there.
The site is at the edge of a residential area, but also
borders on a mixture of commercial properties (retail
stores, restaurants, and offices). Industrial areas are
located approximately one mile north of the site. Two
high population areas (greater than 5000 people per
square mile) are located to the north and west of the
site. In 2007, TO-15 toxics sampling occurred every
12th day. PAMS VOC and carbonyl sampling were
discontinued.
BOLD = EPA-designated NATTS Site
-------
Table 5-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Arizona
monitoring sites. County-level vehicle registration and population data for Maricopa County,
Arizona were obtained from the Arizona Department of Transportation and the U.S. Census
Bureau. Table 5-2 also includes a vehicle registration to county population ratio (vehicles per
person). In addition, the population within 10 miles of each site is presented. An estimate of
10-mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 5-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. For both sites, traffic data for locations along 1-17
were gathered. Finally, Table 5-2 presents the daily VMT for each urban area.
Table 5-2. Population, Motor Vehicle, and Traffic Information for the Arizona Monitoring
Sites
Site
PXSS
SPAZ
2007
Estimated
County
Population
3,880,181
3,880,181
Number
of
Vehicles
Registered
3,793,646
3,793,646
Vehicles
per Person
(Registration:
Population)
0.98
0.98
Population
Within
10 Miles
1,511,946
926,660
Estimated
10-mile
Vehicle
Ownership
1,478,227
905,994
Annual
Average
Traffic
Data1
206,000
113,000
VMT
(thousands)
77,267
77,267
BOLD = EPA-designated NATTS Site
Observations from Table 5-2 include the following:
• Maricopa County had the fourth highest county population and second highest
county-level vehicle registration compared to all counties with NATTS or UATMP
sites.
• The vehicle per person ratio was nearly one vehicle per person.
• The 10-mile radius population and estimated vehicle ownership was higher near
PXSS than SPAZ.
• PXSS experienced a higher annual average traffic volume than SPAZ, based on
locations along 1-17. The PXSS traffic volume was the fourth highest of all UATMP
and NATTS sites, behind CELA, SEW A, and PRRI.
5-6
-------
• The Phoenix area VMT ranked eleventh among urban areas with UATMP or NATTS
sites.
5.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Arizona on sampling days, as well as over the course of the year.
5.2.1 Climate Summary
The Phoenix area is located in the Salt River Valley, which is part of the Sonora Desert.
The area experiences mild winters and extremely hot and dry summers. Differences between the
daytime maximum temperature and overnight minimum temperature can be as high as 50°F. A
summer "monsoon" period brings precipitation to the area for part of the summer, while storms
originating off the Pacific Coast bring rain in the winter and early spring. Winds are generally
light. (Ruffner and Bair, 1987, and WRCC, 2006).
5.2.2 Meteorological Conditions in 2007
Hourly meteorological data from weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at Phoenix Sky Harbor International Airport (near PXSS) and
Phoenix Deer Valley Airport (near SPAZ) WBAN 23183 and 03184, respectively.
Table 5-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 5-3 is the 95 percent
confidence interval for each parameter. As shown in Table 5-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year. Table 5-3 also shows that these sites experience some of the lowest relative humidity
levels among all of the NATTS and UATMP monitoring sites.
5-7
-------
Table 5-3. Average Meteorological Conditions near the Arizona Monitoring Sites
Site
PXSS
SPAZ
Closest NWS
Station and
WBAN
Phoenix Sky
Harbor Intl
Airport
23183
Phoenix Deer
Valley Airport
03184
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
88.41
±3.96
86.95
±1.73
88.60
±9.14
84.63
±1.69
Average
Temperature
(op)
77.48
±3.84
76.30
± 1.69
78.94
±8.85
74.17
±1.65
Average
Dew Point
Temperature
(°F)
36.77
±3.10
37.19
±1.44
38.51
±8.58
35.44
±1.48
Average
Wet Bulb
Temperature
(»F)
56.18
±2.36
55.93
±1.07
57.40
±6.11
54.37
±1.07
Average
Relative
Humidity
(%)
28.09
±3.26
29.92
± 1.62
27.53
±7.36
29.70
±1.70
Average
Sea Level
Pressure
(mb)
1011.35
±1.21
1011.59
±0.54
1010.60
±2.08
1011.48
±0.52
Average
Scalar Wind
Speed
(kt)
5.60
±0.52
5.40
±0.21
4.67
±1.35
4.67
±0.21
BOLD = EPA-designated NATTS Site
oo
-------
5.2.3 Composite Back Trajectories for Sampling Days
Figures 5-4 and 5-5 are composite back trajectory maps for the Arizona monitoring sites
for days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the sites in Figures 5-4 and 5-5 represents 100 miles.
Observations from Figures 5-4 and 5-5 include the following:
• Back trajectories originated from a variety of directions at PXSS. However, a cluster
of the trajectories originated from the southwest and west.
• The 24-hour air shed domain was smaller for PXSS than for most other monitoring
sites. The furthest away a trajectory originated was off the California coast, or
approximately 400 miles away. However, most trajectories originated within 300
miles of PXSS.
• Sampling was conducted at SPAZ for the second half of the calendar year. In
addition, samples were collected every 12 days at SPAZ, which is half the frequency
of sample collection at PXSS. As a result, fewer trajectories are shown in Figure 5-5.
• Trajectories from SPAZ seem to follow a similar pattern as those from PXSS.
• Most trajectories originated within 300 miles of SPAZ.
5.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations at Phoenix Sky Harbor International Airport
(for PXSS) and Phoenix Deer Valley Airport (for SPAZ) were uploaded into a wind rose
software program, WRPLOT (Lakes, 2006) to produce customized wind roses. A wind rose
shows the frequency of wind directions on a 16-point compass, and uses different shading to
represent wind speeds. Figures 5-6 and 5-7 are the wind roses for the Arizona monitoring sites
on days that samples were collected.
Observations from Figure 5-6 for PXSS include the following:
• Easterly winds were most prevalent (19 percent of wind observations), followed by
westerly winds (11 percent).
5-9
-------
Figure 5-4. Composite Back Trajectory Map for PXSS
o
-------
Figure 5-5. Composite Back Trajectory Map for SPAZ
-------
Figure 5-6. Wind Rose for PXSS Sampling Days
NORTH"---.
SOUTH .--
WIND SPEED
(Knots)
O :=22
• 17 • 21
• 1-1 - 17
• 7- 11
CH 1-7
Calms: 16.81*
Figure 5-7. Wind Rose for SPAZ Sampling Days
NORTH"---.
1 5%
SOUTH .--
WIND SPEED
(Knots)
O i=22
^| 17 - 21
^| 11 - 17
^| 7- 11
CH 1-7
• 2- 4
Calms: 29.97%
5-12
-------
• Calm winds were observed for nearly 17 percent of the hourly measurements. Winds
exceeding 11 knots made up less than 9 percent of observations.
Observations from Figure 5-7 for SPAZ include the following:
• Wind direction fluctuated more near SPAZ than PXSS.
• Calm winds were observed more frequently near SPAZ than PXSS (nearly 30
percent). Winds exceeding 11 knots made up less than 8 percent of observations.
• For wind speeds greater than two knots, north-northeasterly winds were most often
observed (11 percent of wind observations), followed by southwesterly winds (10
percent).
5.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Arizona
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 5-4 presents the pollutants that failed at least one screen for each Arizona monitoring site
and highlights each site's pollutants of interest (shaded). PXSS sampled for VOC, carbonyls,
SVOC, metals (PMio), and hexavalent chromium; SPAZ sampled for VOC only.
Observations from Table 5-4 include the following:
• The number of pollutants failing screens varied significantly between the two
monitoring sites.
• Sixteen pollutants with a total of 386 measured concentrations failed at least one
screen for PXSS.
• Ten pollutants with a total of 88 measured concentrations failed screens for SPAZ.
• Six pollutants of interest were common to both sites: acrolein, benzene, 1,3-
butadiene, carbon tetrachloride, />-dichlorobenzene, and tetrachloroethylene.
5-13
-------
Table 5-4. Comparison of Measured Concentrations and EPA Screening Values for
the Arizona Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Phoenix, Arizona - PXSS
Manganese (PM10)
Arsenic (PM10)
Acetaldehyde
Formaldehyde
Acrolein
Benzene
Carbon Tetrachloride
1,3 -Butadiene
£>-Dichlorobenzene
Naphthalene
Tetrachloroethylene
Hexavalent Chromium
Nickel (PM10)
Acrylonitrile
Cadmium (PM10)
Hexachloro- 1 , 3 -butadiene
Total
58
54
30
30
27
27
27
25
25
23
22
20
13
3
1
1
386
59
59
30
30
27
27
27
26
26
28
26
57
59
3
59
1
544
98.31
91.53
100.00
100.00
100.00
100.00
100.00
96.15
96.15
82.14
84.62
35.09
22.03
100.00
1.69
100.00
70.96
15.03
13.99
7.77
7.77
6.99
6.99
6.99
6.48
6.48
5.96
5.70
5.18
3.37
0.78
0.26
0.26
15.03
29.02
36.79
44.56
51.55
58.55
65.54
72.02
78.50
84.46
90.16
95.34
98.70
99.48
99.74
100.00
South Phoenix, Arizona - SPAZ
Carbon Tetrachloride
Acrolein
1,3 -Butadiene
Benzene
£>-Dichlorobenzene
Acrylonitrile
Tetrachloroethylene
Xylenes
Carbon Bisulfide
1 , 1 ,2,2-Tetrachloroethane
Total
14
14
13
13
12
10
8
2
1
1
88
14
14
13
14
13
10
12
14
14
1
119
100.00
100.00
100.00
92.86
92.31
100.00
66.67
14.29
7.14
100.00
73.95
15.91
15.91
14.77
14.77
13.64
11.36
9.09
2.27
1.14
1.14
15.91
31.82
46.59
61.36
75.00
86.36
95.45
97.73
98.86
100.00
Of the six common pollutants of interest, 100 percent of the measured detections of
acrolein and carbon tetrachloride failed screens for PXSS and SPAZ.
Of the pollutants with at least one failed screen, 71 percent of measurements failed
screens for PXSS, while 74 percent failed screens for SPAZ.
5-14
-------
5.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Arizona monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
5.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 5-5, where applicable.
Observations for PXSS from Table 5-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (4.98 ± 0.45 |ig/m3), acetaldehyde (3.32 ± 0.42 |ig/m3), and acrolein
(2.27 ± 0.46 |ig/m3).
• As shown in Tables 4-9 through 4-11, of the program-level pollutants of interest,
PXSS had the highest daily average concentration of acrolein, benzene, manganese
(PMio), and tetrachloroethylene. In addition, daily average concentration of the
following pollutants for PXSS were among the 10 highest average concentration for
all NATTS and UATMP sites: acetaldehyde, acrylonitrile, arsenic (PMio), 1,3-
butadiene, formaldehyde, and/?-dichlorobenzene.
• Winter and spring averages could only be calculated for metals and hexavalent
chromium because sampling for SVOC, VOC, and carbonyls began in July.
• Based on the available seasonal averages, concentrations of the pollutants of interest
tended to be higher in autumn than the summer, with a few exceptions.
5-15
-------
Table 5-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Arizona Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(jig/m3)
Annual
Average1
(Ug/m3)
Phoenix, Arizona - PXSS
1,3 -Butadiene
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
Carbon Tetrachloride
Formaldehyde
Hexavalent Chromium
Manganese (PM10)
Naphthalene
£>-Dichlorobenzene
Tetrachloroethylene
26
30
27
59
27
27
30
57
59
28
26
26
27
30
27
59
27
27
30
57
59
28
27
27
0.30
±0.08
3.32
±0.42
2.27
±0.46
O.01
2.06
±0.47
0.60
±0.04
4.98
±0.45
O.01
0.02
±0.01
0.09
±0.02
0.39
±0.08
0.77
±0.25
NA
NA
NA
O.01
NA
NA
NA
O.01
0.01
±0.01
NA
NA
NA
NA
NA
NA
<0.01
NA
NA
NA
<0.01
0.02
±0.01
NA
NA
NA
0.10
±0.02
2.68
±0.33
3.15
±1.00
O.01
1.03
±0.25
0.56
±0.11
4.67
±0.47
O.01
0.02 ±
0.01
0.04
±0.01
0.25
±0.06
0.25
±0.09
0.39
±0.13
3.85
±0.65
1.92
±0.43
O.01
2.73
±0.71
0.62
±0.04
5.51
±0.69
O.01
0.03
±0.01
0.11
±0.02
0.49
±0.13
1.13
±0.39
NA
NA
NA
O.01
NA
NA
NA
O.01
NA
NA
NA
NA
South Phoenix, Arizona - SPAZ
1,3 -Butadiene
Acrolein
Acrylonitrile
Benzene
Carbon Tetrachloride
/>-Dichlorobenzene
Tetrachloroethylene
13
14
10
14
14
13
12
14
14
14
14
14
14
14
0.24 ±
0.10
1.23 ±
0.31
1.07 ±
0.27
2.01 ±
0.68
0.60 ±
0.05
0.31 ±
0.10
0.39 ±
0.19
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NR
NR
NR
NR
NR
NR
NR
0.32 ±
0.14
1.06±
0.29
NR
2.87 ±
0.70
0.62 ±
0.06
0.31 ±
0.10
0.49 ±
0.26
NA
NA
NA
NA
NA
NA
NA
NR = Not reportable due to the detection criteria for calculating a seasonal average.
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average.
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
5-16
-------
Observations for SPAZ from Table 5-5 include the following:
• The pollutants with the highest daily average concentrations by mass were benzene
(2.01 ± 0.68 |ig/m3), acrolein (1.23 ± 0.31 |ig/m3), and acrylonitrile (1.07 ± 0.27
|ig/m3).
• As shown in Table 4-11, of the program-level pollutants of interest, SPAZ had the
highest daily average concentration of acrylonitrile. In addition, the daily average
concentrations of the following pollutants for SPAZ were among the 10 highest
average concentration for all NATTS and UATMP sites: acrolein, benzene, 1,3-
butadiene, />-dichlorobenzene, and tetrachloroethylene.
• Seasonal averages could only be calculated for autumn. Summer averages could not
be calculated because sampling began in July and the l-in-12 sampling schedule did
not yield enough samples in July and August for a valid seasonal average calculation.
• Annual averages were not calculated for this site due to the short sampling duration.
5.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. Neither PXSS nor SPAZ have sampled continuously for five years as
part of the National Monitoring Program; therefore, the trends analysis was not conducted.
5.5 Pearson Correlations
Table 5-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for PXSS from Table 5-6 include the following:
• Strong negative correlations were calculated between 1,3-butadiene and the
temperature variables, indicating that as temperature increase, concentrations of 1,3-
butadiene decrease. Although the remaining correlations were generally weak, they
were mostly negative, supporting this inverse tendency.
5-17
-------
Table 5-6. Pearson Correlations for Selected Meteorological Parameters and the Pollutants of Interest for the Arizona
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar
Wind
Speed
Phoenix, Arizona - PXSS
1,3 -Butadiene
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
Carbon Tetrachloride
Formaldehyde
Hexavalent Chromium
Manganese (PM10)
Naphthalene
£>-Dichlorobenzene
Tetrachloroethylene
26
30
27
59
27
27
30
57
59
28
26
26
-0.56
-0.10
0.41
-0.26
-0.39
-0.14
0.20
-0.13
0.02
-0.38
-0.14
-0.27
-0.65
-0.20
0.39
-0.29
-0.48
-0.18
0.12
-0.18
0.00
-0.46
-0.23
-0.37
-0.57
-0.33
0.21
-0.15
-0.50
0.05
-0.05
-0.18
-0.13
-0.53
-0.30
-0.41
-0.68
-0.30
0.33
-0.28
-0.54
-0.08
0.02
-0.21
-0.05
-0.56
-0.29
-0.43
0.06
-0.27
-0.21
0.11
-0.08
0.21
-0.35
-0.02
-0.19
-0.08
-0.18
-0.14
0.61
0.25
-0.29
0.21
0.49
0.12
-0.06
0.24
0.01
0.51
0.27
0.31
-0.70
-0.66
0.15
-0.24
-0.69
-0.21
-0.55
-0.30
0.12
-0.57
-0.52
-0.57
South Phoenix, Arizona - SPAZ
1,3 -Butadiene
Acrolein
Acrylonitrile
Benzene
Carbon Tetrachloride
£>-Dichlorobenzene
Tetrachloroethylene
13
14
10
14
14
13
12
-0.54
0.39
0.24
-0.37
-0.02
0.03
-0.18
-0.60
0.35
0.21
-0.43
0.04
-0.02
-0.26
-0.54
0.12
-0.09
-0.49
-0.10
-0.17
-0.40
-0.67
0.26
0.08
-0.53
-0.04
-0.14
-0.40
-0.16
-0.18
-0.23
-0.29
-0.13
-0.34
-0.33
0.77
-0.29
-0.35
0.62
0.09
0.07
0.45
-0.41
-0.17
0.23
-0.35
0.53
-0.30
-0.46
oo
-------
• Strong negative correlations were calculated between 1,3-butadiene, benzene, and
naphthalene and the dew point and wet bulb temperatures. This indicates that as
moisture content increases, concentrations of these pollutants decrease. Although the
remaining correlations were generally weak, they were mostly negative, supporting
this inverse tendency. This trend was not reflected in the relative humidity
correlations.
• These same three pollutants also had strong positive correlations with sea level
pressure.
• Most of the pollutants of interest exhibited strong negative correlations with wind
speed, indicating that concentrations of the pollutants of interest increase as wind
speeds decrease.
Observations for SPAZ from Table 5-6 include the following:
• Benzene and 1,3-butadiene exhibited strong negative correlations with certain
temperature and moisture variables, similar to PXSS.
• Although fewer pollutants of interest exhibited strong negative correlations with wind
speed, most of the correlations were still negative.
5.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
5.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Arizona
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 5-7. Where a seasonal or annual average exceeds the
5-19
-------
Table 5-7. MRL Risk Screening Assessment Summary for the Arizona Monitoring Sites
Site
PXSS
SPAZ
Method
TO-15
TO-15
Pollutant
Acrolein
Acrolein
ATSDR
Acute
MRL
(Hg/m3)
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/27
0/14
ATSDR
Intermediate
MRL
(Hg/m3)
0.09
0.09
Winter
Average
(Hg/m3)
NA
NA
Spring
Average
(Hg/m3)
NA
NA
Summer
Average
(Hg/m3)
3.15
±1.00
NR
Autumn
Average
(Hg/m3)
1.92
±0.43
1.06
±0.29
ATSDR
Chronic
MRL
(Hg/m3)
—
-
Annual
Average
(Hg/m3)
NA
NA
~ = an MRL risk factor is not available
BOLD = EPA-designated NATTS Site
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
NR = Not reportable due to the detection criteria for calculating a seasonal average
BOLD = exceedance of the intermediate or chronic MRL
to
o
-------
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 5-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL
for either site.
• For PXSS, the summer and autumn seasonal averages of acrolein exceeded the
intermediate MRL. Winter and spring averages could not be calculated because
sampling for VOC did not begin until July.
• For SPAZ, the autumn seasonal average of acrolein exceeded the intermediate MRL.
Winter and spring averages could not be calculated because sampling did not begin
until July. A summer average could not be calculated because there were less than
seven detects of this pollutant.
• Acrolein has no chronic MRL. In addition, annual averages could not be calculated
for these two sites because they did not begin sampling VOC until July. Therefore, a
chronic risk comparison could not be conducted.
5.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Arizona monitoring sites and where
the annual average concentrations could be calculated, risk was further examined by reviewing
cancer and noncancer risk estimates from NATA and calculating cancer and noncancer surrogate
risk approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
noncancer surrogate risk approximations are presented in Table 5-8. The data from NATA are
presented for the census tract where each monitoring site is located. The pollutants of interest
for each site are bolded.
The census tract information for the Arizona monitoring sites is as follows:
• The census tract for PXSS is 04013108902, which had a population of 5,222, and
represented less than one percent of the Maricopa County population in 2000.
• The census tract for SPAZ is 04013115802, which had a population of 2,938, and
represented less than one percent of the Maricopa County population in 2000.
5-21
-------
Table 5-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Arizona
Pollutant
Cancer
URE
(Hg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Phoenix, Arizona (PXSS) - Census Tract ID 04013108902
Acetaldehyde
Acrolein
Acrylonitrile
Arsenic (PM10)
Benzene
1,3-Butadiene
Cadmium (PM10)
Carbon Tetrachloride
Formaldehyde
Hexachloro- 1 ,3 -butadiene
Hexavalent Chromium
Manganese (PM10)
Naphthalene
Nickel (PM10)
p-Dichlorobenzene
Tetrachloroethylene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.0018
0.000015
5.5E-09
0.000022
0.012
—
0.000034
0.00016
0.000011
0.000005
0.009
0.00002
0.002
0.00003
0.03
0.002
0.00002
0.04
0.0098
0.09
0.0001
0.00005
0.003
0.000065
0.8
0.27
2.07
0.19
0.01
0.01
1.69
0.16
O.01
0.21
2.07
0.01
0.01
0.01
0.08
O.01
0.08
0.36
4.58
—
0.33
0.05
13.22
4.87
0.02
3.15
0.01
0.03
0.36
—
2.85
0.02
0.90
2.15
0.23
9.67
0.01
0.01
0.05
0.08
O.01
0.01
0.21
0.01
0.01
0.01
0.02
O.01
O.01
O.01
NA
NA
NA
0.01 ±0.01
NA
NA
O.OliO.Ol
NA
NA
NA
0.01 ±0.01
0.02 ±0.01
NA
O.01±O.01
NA
NA
NA
NA
NA
3.15
NA
NA
0.28
NA
NA
NA
1.03
—
NA
0.26
NA
NA
NA
NA
NA
0.02
NA
NA
0.01
NA
NA
NA
0.01
0.38
NA
0.03
NA
NA
to
to
— = a URE or RfC is not available
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 5-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Arizona (Continued)
Pollutant
Cancer
URE
(Hg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
South Phoenix, Arizona (SPAZ) - Census Tract ID 04013115802
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Bisulfide
Carbon Tetrachloride
p-Dichlorobenzene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Xylenes
—
0.000068
0.000007
0.00003
~
0.000015
0.000011
0.000058
0.000005
-
0.00002
0.002
0.03
0.002
0.7
0.04
0.8
~
0.27
0.1
0.19
0.01
1.67
0.15
0.05
0.21
0.07
0.07
0.23
2.29
—
0.62
13.05
4.62
~
3.16
0.79
3.92
1.36
-
9.63
0.01
0.05
0.07
O.01
0.01
O.01
~
0.01
0.02
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
fj\
to
— = a URE or RfC is not available
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Observations for PXSS from Table 5-8 include the following:
• The pollutants with the highest concentrations according to NATA were
formaldehyde, acetaldehyde, and benzene.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadidne, and acetaldehyde.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (9.67).
• Annual averages (and therefore cancer and noncancer surrogate risk approximations)
could only be calculated for metals and hexavalent chromium due to the sampling
duration criteria. Of those, only manganese had an annual average greater than 0.01
|ig/m3.
• Arsenic had the highest cancer risk approximation at 3.15 in-a-million. None of the
noncancer risk approximations were greater than 1.0.
Observations for SPAZ from Table 5-8 include the following:
• The pollutants with the highest concentrations according to NATA were xylenes,
benzene, and tetrachloroethylene.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadidne, and 1,1,2,2-tetrachloroethane.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (9.63).
• Annual averages (and therefore cancer and noncancer surrogate risks approximations)
could not be calculated due to the sampling duration criteria.
5.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 5-9 and 5-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 5-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
surrogate cancer risk approximations (in-a-million), as calculated from the annual averages.
Table 5-10 presents similar information, but identifies the 10 pollutants with the highest
surrogate noncancer risk approximations (HQ), as calculated from the annual averages. The
5-24
-------
Table 5-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Arizona
fj\
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Phoenix, Arizona (PXSS) - Maricopa County
Benzene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
1 ,3 -Dichloropropene
1,3 -Butadiene
Dichloromethane
/>-Dichlorobenzene
Naphthalene
POM, Group 2
1,928.24
1,054.10
392.41
280.26
238.48
229.90
162.00
123.55
119.63
11.58
Benzene
1,3 -Butadiene
Naphthalene
Hexavalent Chromium
Arsenic, PM
Tetrachloroethylene
£>-Dichlorobenzene
1 ,3 -Dichloropropene
Acetaldehyde
Cadmium, PM
1.50E-02
6.90E-03
4.07E-03
2.54E-03
2.06E-03
1.65E-03
1.36E-03
9.54E-04
8.63E-04
7.52E-04
Arsenic (PM10) 3.15
Hexavalent Chromium 1.03
Cadmium (PM10) 0.28
Nickel (PM10) 0.26
South Phoenix, Arizona (SPAZ) - Maricopa County
Benzene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
1 ,3 -Dichloropropene
1,3 -Butadiene
Dichloromethane
£>-Dichlorobenzene
Naphthalene
POM, Group 2
1,928.24
1,054.10
392.41
280.26
238.48
229.90
162.00
123.55
119.63
11.58
Benzene
1,3 -Butadiene
Naphthalene
Hexavalent Chromium
Arsenic, PM
Tetrachloroethylene
/>-Dichlorobenzene
1 ,3 -Dichloropropene
Acetaldehyde
Cadmium, PM
1.50E-02
6.90E-03
4.07E-03
2.54E-03
2.06E-03
1.65E-03
1.36E-03
9.54E-04
8.63E-04
7.52E-04
-------
Table 5-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Arizona
fj\
to
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentration
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Phoenix, Arizona (PXSS) - Maricopa County
Toluene
Xylenes
Benzene
Methyl fer/-butyl ether
Methanol
Hexane
Formaldehyde
Ethylbenzene
1,1,1 -Trichloroethane
Ethylene glycol
5,912.44
4,253.08
1,928.24
1,629.16
1,263.81
1,117.09
1,054.10
941.78
634.01
507.41
Acrolein
1,3 -Butadiene
Formaldehyde
Bromomethane
Benzene
Acetaldehyde
Xylenes
Naphthalene
Cyanide Compounds, gas
Cadmium, PM
2,746,685.59
114,950.11
107,561.49
66,526.00
64,274.54
43,601.40
42,530.81
39,876.97
38,834.32
20,885.36
Manganese (PM10) 0.38
Nickel (PM10) 0.03
Arsenic (PM10) 0.02
Cadmium (PM10) 0.01
Hexavalent Chromium O.01
South Phoenix, Arizona (SPAZ) - Maricopa County
Toluene
Xylenes
Benzene
Methyl tert-butyl ether
Methanol
Hexane
Formaldehyde
Ethylbenzene
1,1,1 -Trichloroethane
Ethylene glycol
5,912.44
4,253.08
1,928.24
1,629.16
1,263.81
1,117.09
1,054.10
941.78
634.01
507.41
Acrolein
1,3 -Butadiene
Formaldehyde
Bromomethane
Benzene
Acetaldehyde
Xylenes
Naphthalene
Cyanide Compounds, gas
Cadmium, PM
2,746,685.59
114,950.11
107,561.49
66,526.00
64,274.54
43,601.40
42,530.81
39,876.97
38,834.32
20,885.36
-------
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 5.3, PXSS sampled for VOC,
carbonyls, SVOC, metals (PMio), and hexavalent chromium; SPAZ sampled for VOC only. In
addition, the cancer and noncancer surrogate risk approximations are limited to those sites
sampling for a long enough period for annual averages to be calculated. Only metals and
hexavalent chromium were sampled long enough at PXSS for annual averages to be calculated.
Observations from Table 5-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Maricopa County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) were benzene, 1,3-butadiene, and naphthalene.
• Seven of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• For PXSS, arsenic, cadmium, and hexavalent chromium, for which cancer risk
approximations could be calculated, had high toxicity-weighted emissions; yet none
of the pollutants were among the 10 highest emitted pollutants.
Observations from Table 5-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Maricopa County.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, 1,3-butadiene, and formaldehyde.
• Three of the highest emitted pollutants also had the highest toxicity-weighted
emissions.
5-27
-------
• With the exception of cadmium, none of the pollutants for which noncancer risk
approximations could be calculated for PXSS appeared on the list of highest emitted
pollutants or the list of highest toxicity weighted emissions.
5.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Arizona monitoring site were acrolein,
benzene, 1,3-butadiene, carbon tetrachloride, p-dichlorobenzene, and
tetrachloroethylene.
»«» Formaldehyde had the highest daily average concentration for PXSS, while benzene
had the highest daily average concentration for SPAZ.
»«» The summer and autumn seasonal average concentrations of acrolein exceeded the
intermediate MRL health benchmark for PXSS. The autumn seasonal average
concentration of acrolein exceeded the intermediate health benchmark MRL for
SPAZ.
5-28
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6.0 Sites in California
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at NATTS sites in California, and integrates these concentrations with
emissions, meteorological, and risk information.
6.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the locations of the sites and the surrounding areas. The California sites are
located in the Los Angeles-Riverside-Orange County, CA MSA. CELA is located near
downtown Los Angeles and RUCA is located in Rubidoux, near Riverside. Figures 6-1 and 6-2
are composite satellite images retrieved from Google™ Maps showing the monitoring sites in
their urban locations. Figures 6-3 and 6-4 identify point source emission locations within 10
miles of each site as reported in the 2002 NEI for point sources. Table 6-1 describes the area
surrounding each monitoring site and provides supplemental geographical information such as
land, location setting, and locational coordinates.
CELA is located on the rooftop of a two-story building just northeast of downtown Los
Angeles, near Dodgers' Stadium. Figure 6-1 shows that CELA is surrounded by major freeways,
including 1-5, Rt. 110, and Hwy 101. Although the area is classified as residential, a freight yard
is located to the south of the site. The Los Angeles River runs north-south just east of the site.
This monitoring site was originally set up as an emergency response monitor. RUCA is located
just outside of Riverside, in a residential area of the suburban town of Rubidoux. Highway 60
runs east-west to the north of the site. Flabob Airport is located about % of a mile to the
southeast of the site. Figure 6-2 shows that RUCA is adjacent to a power substation near the
intersection of Mission Boulevard and Riverview Drive.
As Figure 6-3 shows, CELA is situated among numerous point sources. Point sources
located in very close proximity to CELA are involved in food product industries, iron and steel
manufacturing, and processes involving fuel combustion. A large number of emission sources
are near CELA are involved in surface coating or utilize fuel combustion processes. Figure 6-4
shows that fewer emission sources surround RUCA. Most of these emission sources are located
6-1
-------
Figure 6-1. Los Angeles, California (CELA) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 6-2. Rubidoux, California (RUCA) Monitoring Site
CVW
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 6-3. NEI Point Sources Located Within 10 Miles of CELA
> Ds
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6-4
-------
Figure 6-4. NEI Point Sources Located Within 10 Miles of RUCA
tii^ifrtrw
Legend
RUCA NATTS site 10 mite radius County boundary
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6-5
-------
Table 6-1. Geographical Information for the California Monitoring Sites
Site
Code
CELA
RUCA
AQS Code
06-037-1103
06-065-8001
Location
Los
Angeles
Rubidoux
County
Los
Angeles
Riverside
]Micro- or
Metropolitan
Statistical Area
Los Angeles-
Riverside-Orange
County, CA CMSA
Los Angeles-
Riverside-Orange
County, CA CMSA
Latitude
and
Longitude
34.06659,
-118.22688
33.999167,
-117.415833
Land Use
Residential
Residential
Location
Setting
Urban/City
Center
Urban/City
Center
Description of the
Immediate Surroundings
CELA is located on the rooftop of a two-story building
just northeast of downtown Los Angeles, near
Dodgers' Stadium. The location is surrounded by
major freeways, including 1-5, Rt. 1 10, and Hwy 101.
A freight yard is located to the south of the site and the
Los Angeles River runs north-south near the site.
Pollutants monitored for include CO, SO2, NO2, O3,
PMio, PM25, and hexavalent chromium.
Meteorological observations are also recorded. West
winds are predominant at the site.
RUCA is located just outside of Riverside, in a
residential area of the suburban town of Rubidoux.
The shelter is located in an enclosed, secure area that
is adjacent to a power substation with unimproved lots
directly to the east of the site. Highway 60 runs east-
west to the north of the site. Flabob Airport is located
about 3/4 of a mile to the southeast of the site.
Pollutants monitored for include CO, SO2, NO2, O3,
PMio, PM25, and hexavalent chromium.
Meteorological observations are also recorded. West
winds are predominant at the site.
o\
BOLD = EPA-designated NATTS Site
-------
to the north of the site. Point sources located in very close proximity to RUCA are involved in
environmental quality and wastewater treatment and disposal. Similar to CELA, the most
common emission source categories for point sources near RUCA are surface coating and fuel
combustion.
Table 6-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
California monitoring sites. County-level vehicle registration and population data for Riverside
and Los Angeles Counties were obtained from the LA Almanac and UC Libraries and the U.S.
Census Bureau. Table 6-2 also includes a vehicle registration to county population ratio
(vehicles per person). In addition, the population within 10 miles of each site is presented. An
estimate of 10-mile vehicle registration was calculated by applying the county-level vehicle
registration to population ratio to the 10-mile population surrounding the monitoring site. Table
6-2 also contains annual average daily traffic information, as well as the year of the traffic data
estimate and the source from which it was obtained. Finally, Table 6-2 presents the daily VMT
for each urban area.
Table 6-2. Population, Motor Vehicle, and Traffic Information for the California
Monitoring Sites
Site
CELA
RUCA
2007
Estimated
County
Population
9,878,554
2,073,571
Number
of
Vehicles
Registered
7,514,916
1,344,232
Vehicles
per Person
(Registration:
Population)
0.76
0.65
Population
Within
10 Miles
3,714,391
975,577
Estimated
10 mile Vehicle
Ownership
2,825,650
632,436
Annual
Average
Traffic
Data1
238,000
17,468
VMT
(thousands)
279,041
42,861
1 Daily Average Traffic Data reflects 2005 data from the LA Almanac (CELA) and 2002 data from the Counting
California, UC Libraries (RUCA)
BOLD = EPA-designated NATTS Site
Observations from Table 6-2 include the following:
• Los Angeles County had the highest county population, county-level vehicle
registration, and 10-mile estimated vehicle ownership compared to all counties with
NATTS or UATMP sites. However, the 10-mile population near this site ranked
second behind BXNY, which is located in the Bronx Borough of New York City.
6-7
-------
• Riverside County had the fifth highest county population and ninth highest county-
level vehicle registration.
• The vehicle per person ratio was somewhat higher for Los Angeles County than
Riverside County.
• CELA experiences the highest average daily traffic volume of any UATMP or
NATTS site and has a substantially higher traffic volume than RUCA. The traffic
data for CELA was based on data from exit 136 off 1-5 at Main Street. The traffic
data for RUCA was based on data from Mission Boulevard, west of Riverview Drive.
• The Los Angeles area's VMT ranked second among urban areas with UATMP or
NATTS sites, while the Riverside area ranked fifteenth.
6.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in California on sampling days, as well as over the course of the year.
6.2.1 Climate Summary
While the proximity to the Pacific Ocean acts as a moderating influence on the city, the
elevation changes between the mountains and valleys allow the distance from the ocean to create
substantial differences in temperature, rainfall, and wind over a relatively short distance.
Overall, the climate of Los Angeles is mild. Precipitation falls primarily in winter months, while
summers tend to be dry. Stagnant wind conditions in the summer can result in air pollution
episodes, while breezy Santa Ana winds can create hot, dusty conditions. Fog and cloudy
conditions are more prevalent near the coast than further inland (Ruffner and Bair, 1987 and
WRCC).
6.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
6-8
-------
NWS weather stations are located at Downtown Los Angeles/USC Campus (near CELA) and
Riverside Municipal Airport (near RUCA) WBAN 93134 and 03171.
Table 6-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 6-3 is the 95 percent
confidence interval for each parameter. As shown in Table 6-3, average meteorological
conditions on sampling days near CELA were fairly representative of average weather conditions
throughout the year. Average meteorological conditions near RUCA were warmer on sampling
days. Both sites began sampling in the spring, thus missing the coldest months of the year. This
seemed to have a larger impact on RUCA's sample day averages than CELA's averages.
6.2.3 Composite Back Trajectories for Sampling Days
Figures 6-5 and 6-6 are composite back trajectory maps for the California monitoring
sites for the days on which samples were collected. Each line represents the 24-hour trajectory
along which a parcel of air traveled toward the monitoring site on a sampling day. Each
concentric circle around the sites in Figures 6-5 and 6-6 represents 100 miles.
Observations from Figures 6-5 and 6-6 include the following:
• Back trajectories originated primarily from the northwest at CELA and RUCA. A
secondary group of trajectories originated from the northeast.
• The 24-hour air shed domains were smaller for these sites than for other monitoring
sites. The furthest away a trajectory originated was northern California or Utah, both
over 500 miles away. However, over 90 percent of trajectories originated within 300
miles of the sites.
• Sampling began in late April or early May at these sites. The composite back
trajectory maps for these sites with a full year's worth of sample days may look much
different.
6-9
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Table 6-3. Average Meteorological Conditions near the California Monitoring Sites
Site
CELA
RUCA
Closest NWS
Station and
WBAN
Downtown
L.A./USC
Campus
93134
Riverside
Municipal
Airport
03171
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
76.02
±2.65
74.16
±0.91
84.80
±5.90
75.01
±1.65
Average
Temperature
(op)
66.17
±2.16
64.11
±0.71
69.12
±4.23
60.85
±1.21
Average
Dew Point
Temperature
(°F)
51.07
±2.97
47.84
±1.13
45.07
± 12.34
39.45
±1.93
Average
Wet Bulb
Temperature
(»F)
57.98
±1.95
55.67
±0.70
53.79
±4.11
50.65
±1.06
Average
Relative
Humidity
(%)
62.25
±4.24
60.01
± 1.51
51.77
±18.55
53.40
±2.55
Average
Sea Level
Pressure
(mb)
1013.70
±1.02
1015.09
±0.39
1011.43
±0.50
1014.85
±0.54
Average
Scalar Wind
Speed
(kt)
1.32
±0.17
1.40
±0.08
6.75
± 1.01
6.18
±0.29
BOLD = EPA-designated NATTS Site
-------
Figure 6-5. Composite Back Trajectory Map for CELA
-------
Figure 6-6. Composite Back Trajectory Map for RUCA
to
0 28 M 100 ISO 100
UrfM
-------
6.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations at the Downtown Los Angeles/USC Campus
(for CELA) and Riverside Municipal Airport near (for RUCA) were uploaded into a wind rose
software program, WRPLOT (Lakes, 2006) to produce customized wind roses. A wind rose
shows the frequency of wind directions on a 16-point compass, and uses different shading to
represent wind speeds. Figures 6-7 and 6-8 are the wind roses for the California monitoring sites
on days that samples were collected.
Observations from Figure 6-7 for CELA include the following:
• Winds were generally light near the site, with calm winds observed for 84 percent of
the observations. Wind speeds greater than 11 knots were not measured at this
weather station.
• For winds greater than two knots, westerly winds were predominant.
Figure 6-7. Wind Rose for CELA Sampling Days
NORTH"---.
10%
8%,
6%..
SOUTH ,-•
WIND SPEED
(Knots)
O K22
• 17 - 21
• 11 . 17
H 7- 11
CH 4-7
6-13
-------
Figure 6-8. Wind Rose for RUCA Sampling Days
vi;:;
35%
21%
14%
SOUTH,-'
EAST
WINDSPEED
(Knots)
^| 17 - 21
^| 11 - 17
cn 4-7
• 2- 4
Calms: 28.75%
Observations from Figure 6-8 for RUCA include the following:
• Both wind speed and direction fluctuated more near RUCA than CELA, although
westerly winds were still the predominant wind direction (31 percent of
observations). West-northwesterly winds were observed for 23 percent of
observations.
• Calm winds were observed for one-third of the observations near RUCA. However,
winds exceeding 11 knots made up nearly 23 percent of observations.
6.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the California
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
6-14
-------
Table 6-4 presents the pollutants that failed at least one screen for each California monitoring
site and highlights each site's pollutants of interest (shaded). CELA and RUCA sampled for
SVOC only.
Observations from Table 6-4 include the following:
• Naphthalene was the only pollutant to fail screens for both sites, making it the only
pollutant of interest for both sites.
• Naphthalene failed 87 percent of screens for CELA and 81 percent of screens for
RUCA.
Table 6-4. Comparison of Measured Concentrations and EPA Screening Values for the
California Monitoring Sites
Pollutant
# of Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Los Angeles, California - CELA
Naphthalene
Total
34
34
39
39
87.18
87.18
100.00
100.00
Rubidoux, California - RUCA
Naphthalene
Total
26
26
32
32
81.25
81.25
100.00
100.00
6.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the California monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
6.4.1 2007 Concentration Averages
Daily, seasonal, and annual averages were calculated for the pollutants of interest, as
described in Section 3.3. The daily average of a particular pollutant is simply the average
concentration of all measured detections. If there were at least seven measured detections within
each season, then a seasonal average was calculated. The seasonal average includes 1/2 MDLs
6-15
-------
substituted for all non-detects. Finally, the annual average is the average concentration of all
measured detections and 1/2 MDLs substituted for non-detects. Annual averages were
calculated for monitoring sites where sampling began no later than February and ended no earlier
than November and where the completeness was greater than or equal to 85 percent. Daily,
seasonal, and annual averages are presented in Table 6-5, where applicable.
Table 6-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the California Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Ug/m3)
Winter
Average
(Ug/m3)
Spring
Average
(Ug/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Ug/m3)
Annual
Average
(Ug/m3)
Los Angeles, California - CELA
Naphthalene
39
39
0.07
±0.01
NA
NR
0.05
±0.01
0.08
±0.02
NA
Rubidoux, California - RUCA
Naphthalene
32
32
0.06
±0.01
NA
NR
0.05
±0.01
0.07
±0.02
NA
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
NR = Not reportable due to the detection criteria for calculating a seasonal average
Observations for the California monitoring sites from Table 6-5 include the following:
• The daily averages of naphthalene were similar for both sites.
• Because sampling did not begin until late spring at CELA and RUCA, winter and
spring averages could not be calculated. The summer and autumn averages varied
little.
• Annual averages were not calculated due to the short sampling duration.
6.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. Neither CELA nor RUCA have sampled continuously for five years
as part of the National Monitoring Program; therefore, the trends analysis was not conducted.
6-16
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6.5 Pearson Correlations
Table 6-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for the California sites from Table 6-6 include the following:
• The correlations with naphthalene were generally weak at the California sites.
• However, the strongest correlation for CELA was calculated for relative humidity
(-0.44) and the strongest correlation for RUCA was calculated for wind speed (-0.49).
6.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
6.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the California
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. None of the pollutants
measured at the California sites exceeded any of the MRL risk values.
6-17
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Table 6-6. Pearson Correlations Between Selected Meteorological Parameters and Pollutants of Interest for the California
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Los Angeles, California - CELA
Naphthalene
39
0.12
-0.09
-0.41
-0.33
-0.44
0.22
-0.43
Rubidoux, California - RUCA
Naphthalene
32
-0.17
-0.18
-0.15
-0.18
-0.17
-0.19
-0.49
oo
-------
6.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the California monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 6-7. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the California sites is as follows:
• The census tract for CELA is 06037463500, which had a population of 5,396, and
represented less than one percent of the Los Angeles County population in 2000.
• The census tract for RUCA is 06065040301, which had a population of 6,634, and
represented less than one percent of the Riverside County population in 2000.
Observations for California sites from Table 6-7 include the following:
• Naphthalene was the only pollutant to fail screens for the California sites.
• The NATA modeled concentration of naphthalene is slightly higher for CELA than
RUCA, which translated into slightly higher cancer and noncancer risks.
• Annual averages (and therefore cancer and noncancer surrogate risk approximations)
could not be calculated for naphthalene due to the sampling duration criteria.
6-19
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Table 6-7. Cancer and Noncancer Risk Summary for the Monitoring Sites in California
Pollutant
Cancer
URE
(Hg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Los Angeles, California (CELA) - Census Tract ID 06037463500
Naphthalene
0.000034
0.003
0.13
4.51
0.04
NA
NA
NA
Rubidoux, California (RUCA) - Census Tract ID 06065040301
Naphthalene
0.000034
0.003
0.09
3.03
0.02
NA
NA
NA
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
to
o
-------
6.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 6-8 and 6-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 6-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
surrogate cancer risk approximations (in-a-million), as calculated from the annual averages.
Table 6-9 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual average are limited to those pollutants
for which each respective site sampled. As discussed in Section 6.3, the California monitoring
sites sampled only for SVOC. In addition, the cancer and noncancer surrogate risk
approximations are limited to those sites sampling for a long enough period for annual averages
to be calculated. Because sampling did not begin until late spring, cancer and noncancer risk
approximations were not calculated for the California monitoring sites.
Observations from Table 6-8 include the following:
• Formaldehyde, benzene, and dichloromethane were the highest emitted pollutants
with cancer UREs in both Los Angeles and Riverside County, although the quantity
emitted was much higher for Los Angeles County.
• The two pollutants with the highest toxicity-weighted emissions (of the pollutants
with cancer UREs) were benzene and 1,3-butadiene for both counties.
• Six of the highest emitted pollutants also have the highest toxicity-weighted
emissions for both counties.
• Naphthalene, which was the only pollutant to fail screens for either site, appears on
both top 10 lists for both counties. Naphthalene had the third highest toxicity-
weighted emissions for Los Angeles County and fourth highest toxicity-weighted
emissions for Riverside County.
6-21
-------
Table 6-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in California
to
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Los Angeles, California (CELA) - Los Angeles County
Formaldehyde
Benzene
Dichloromethane
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
£>-Dichlorobenzene
Naphthalene
Trichloroethylene
1 ,3 -Dichloropropene
3,761.00
3,358.23
2,821.10
1,973.72
1,156.58
553.78
511.02
344.62
205.49
73.69
Benzene
1,3 -Butadiene
Naphthalene
Tetrachloroethylene
Hexavalent Chromium
/>-Dichlorobenzene
Arsenic, PM
Acrylonitrile
Hydrazine
Acetaldehyde
2.62E-02
1.66E-02
1.17E-02
1.16E-02
8.60E-03
5.62E-03
3.29E-03
3.23E-03
3.06E-03
2.54E-03
Rubidoux, California (RUCA) - Riverside County
Formaldehyde
Benzene
Dichloromethane
Acetaldehyde
Tetrachloroethylene
1,3 -Butadiene
£>-Dichlorobenzene
1 ,3 -Dichloropropene
Naphthalene
Trichloroethylene
775.04
744.15
357.00
261.24
236.94
105.53
84.46
65.85
60.11
27.54
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Tetrachloroethylene
Arsenic, PM
£>-Dichlorobenzene
Acrylonitrile
Acetaldehyde
Cadmium, PM
5.80E-03
3.17E-03
2.59E-03
2.04E-03
1.40E-03
9.87E-04
9.29E-04
6.97E-04
5.75E-04
5.53E-04
-------
Table 6-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in California
to
oo
Top 10 Total Emissions for Pollutants
with Nonancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentration
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Los Angeles, California (CELA) - Los Angeles County
1,1,1 -Trichloroethane
Toluene
Methyl tert- butyl ether
Xylenes
Formaldehyde
Methanol
Benzene
Dichloromethane
Hexane
Tetrachloroethylene
11,143.75
10,867.59
7,231.31
6,551.48
3,761.00
3,728.19
3,358.23
2,821.10
2,732.53
1,973.72
Acrolein
Chlorine
Formaldehyde
1,3 -Butadiene
Acetaldehyde
Naphthalene
Nickel, PM
Benzene
Manganese, PM
Xylenes
9,822,537.40
757,779.08
383,775.50
276,889.19
128,508.79
114,873.21
113,809.87
111,941.11
110,563.54
65,514.80
Rubidoux, California (RUCA) - Riverside County
Toluene
Xylenes
Methyl ter/-butyl ether
1,1,1 -Trichloroethane
Formaldehyde
Benzene
Methanol
Hexane
Dichloromethane
Ethylbenzene
1,964.44
1,355.80
1,296.42
1,122.24
775.04
744.15
573.39
454.07
357.00
264.61
Acrolein
Chlorine
Formaldehyde
1,3 -Butadiene
Manganese, PM
2,4-Toluene diisocyanate
Bromomethane
Acetaldehyde
Benzene
Naphthalene
2,142,512.31
154,853.27
79,085.43
52,763.78
41,359.46
37,029.00
29,494.00
29,026.13
24,805.07
20,035.08
-------
Observations from Table 6-9 include the following:
• 1,1,1-Trichloroethylene, toluene, methyl tert butyl ether, and xylenes were the highest
emitted pollutants with noncancer RfCs in both counties, although not necessarily in
that order.
• Similar to pollutants with cancer UREs, emissions were higher in Los Angeles
County than Riverside County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, chlorine, and formaldehyde for both counties.
• Three of the highest emitted pollutants in Los Angeles County also have the highest
toxi city-weighted emissions and only two of the highest emitted pollutants in
Riverside County also have the highest toxicity-weighted emissions
• Naphthalene had the sixth and tenth highest toxicity-weighted emissions for Los
Angeles and Riverside Counties, respectively, but is not one of the highest emitted
pollutants with a noncancer toxicity factor in either county.
6.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Naphthalene was the only pollutant to fail screens for both California monitoring
sites.
»«» The daily and seasonal average concentrations of naphthalene, where they could be
calculated, were similar for both sites.
»«» Naphthalene did not exceed any of the MRL health benchmarks.
6-24
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7.0 Site in Colorado
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Colorado, and integrates these concentrations with
emissions, meteorological, and risk information.
7.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Colorado site is located
in the Grand Junction, CO MSA. Figure 7-1 is a composite satellite image retrieved from
Google™ Maps showing the monitoring site in its urban location. Figure 7-2 identifies point
source emission locations within 10 miles of the site as reported in the 2002 NEI for point
sources. Table 7-1 describes the area surrounding the monitoring site and provides supplemental
geographical information such as land use, location setting, and locational coordinates.
The GPCO monitoring site is comprised of two locations. The first is a small 1-story
shelter that houses the VOC/carbonyl sampler. The second location is on an adjacent 2-story
building that has the filter-based PMio and hexavalent chromium samplers on the roof. As a
result, two AQS codes are provided in Table 7-1. Figure 7-1 shows that the area surrounding
GPCO is very mixed usage, with commercial businesses to the west, northwest and north,
residential areas to the northeast and east, and industrial areas to the southeast, south and
southwest. The site's location is next to one of the major east-west roads in Grand Junction. A
railroad runs east-west to the south of the GPCO monitoring site, and merges with another
railroad to the southwest of the site. As Figure 7-2 shows, GPCO is located within 10 miles of
numerous emission sources, many of which are located in close proximity of the site. A large
number of point sources near GPCO fall into the liquids distribution source category.
Table 7-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Colorado monitoring site. County-level vehicle registration and population data for Mesa
County, Colorado were obtained from the Colorado Department of Revenue and the U.S. Census
7-1
-------
Figure 7-1. Grand Junction, Colorado (GPCO) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 200
-------
Figure 7-2. NEI Point Sources Located Within 10 Miles of GPCO
Hoi*: DIM (»fKUly dwiwtj and «*M*txxi m* lettl lnOllMt
tftsp-liyed may nol r*|)r*-i«il al facjWw* Attwi Dw ai*a at citw«t.
Legend
•^ GPCO NATTS site 10 irtte radius J County boundary
Source Category Group (No. of Facilities)
A Agricultural Services Facilrty (1)
i Automobile Dealers (1)
» Automotive Repair. Services. & Parking (3)
c Chemicals & Allied Products Facility (2)
D Fabricated Metal Products Facility (1)
F Fuel Combustion industrial Facility (4)
•*• Heallh Services Facility (1)
i Uquds Distribution Industrial Facility (52)
B Mineral Products Processing hvlustnal Facility |1)
P Miscellaneous Rocesses Induslrial Facilrty (7)
P PetfcJeunvtslat GasProct & Refining Indifitrlal Facility (1)
Y Rubber & H isoelfa neous Raslre ProdiKts Facility (1)
s Surface Coating Processes Induslrial Facility (6)
+ Transportation I?/ Alt (3)
! V\teste Treatment & Disposal Industrial Facility (3)
Water Transportation Facility (1)
r Wholesale Trade (1}
7-3
-------
Table 7-1. Geographical Information for the Colorado Monitoring Site
Site
Code
GPCO
AQS Code
08-077-0017
&
08-077-0018
Location
Grand
Junction
County
Mesa
Micro- or
Metropolitan
Statistical Area
Grand Junction,
CO
Latitude
and
Longitude
39.064295,
-108.561545
Land Use
Commercial
Location
Setting
Urban/City
Center
Description of the
Immediate Surroundings
The GPCO site is comprised of two locations. The
first is a small 1 -story shelter that houses the
VOC/carbonyl sampler (08-077-0018, 645 ^Pitkin
Avenue). The inlet for this sampler is 13' above the
ground and 35' south of Pitkin Avenue. This location
also has meteorological sensors (WS, WD, T, RH) on
a 10 meter tower, a carbon monoxide sampler and a
continuous PM10 sampler. The second location is on
an adjacent 2-story building that has the filter-based
PM10 and hexavalent chromium samplers on the roof
(08-077-0017, 650 South Avenue). This location also
has a filter-based PM2 5 sampler, a PM2 5 speciation
sampler and a continuous PM2 5 sampler. Monitoring
is being conducted on the southeast side of the
downtown area. The area is very mixed usage, with
commercial businesses to the west, northwest and
north, residential to the northeast and east, and
industrial to the southeast, south and southwest. The
location is next to one of the major east-west roads in
Grand Junction.
BOLD = EPA-designated NATTS Site
-------
Table 7-2. Population, Motor Vehicle, and Traffic Information for the Colorado
Monitoring Site
Site
GPCO
2007
Estimated
County
Population
139,082
Number
of
Vehicles
Registered
163,539
Vehicles
per Person
(Registration:
Population)
1.18
Population
Within
10 Miles
114,523
Estimated
10 mile Vehicle
Ownership
134,661
Annual
Average
Traffic
Data1
12,300
VMT
(thousands)
2,024
1 Daily Average Traffic Data reflects 2006 data from the Colorado DOT
BOLD = EPA-designated NATTS Site
Bureau. Table 7-2 also includes a vehicle registration to county population ratio (vehicles per
person). In addition, the population within 10 miles of the site is presented. An estimate of
10-mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 7-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 7-2 presents the daily VMT for the
urban area.
Observations from Table 7-2 include the following:
• GPCO's county and 10-mile populations were in the low to mid-range compared to
all counties with NATTS or UATMP sites. This is also true for its county-level and
10-mile vehicle ownership.
• The vehicle per person ratio was the fifth highest compared to other NATTS or
UATMP sites.
• The traffic volume experienced near GPCO also ranked in the low to mid-range
compared to other monitoring sites. The traffic estimate used came from Business-70
between 5th and 7th Streets.
• The Grand Junction area VMT was the second lowest among urban areas with
UATMP or NATTS sites.
7.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Colorado on sampling days, as well as over the course of the year.
7-5
-------
7.2.1 Climate Summary
Grand Junction is located in a mountain valley on the west side of the Rockies. This
location can help protect the area from dramatic weather changes. The area tends to be rather
dry and winds tend to flow out of the east-southeast on average, due to the valley breeze effect.
Valley breezes occur as the sun heats up the side of a mountain. The warm air rises, creating a
current that will move up the valley walls (Ruffner and Bair, 1987).
7.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Walker Field Airport (WBAN 23066).
Table 7-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 7-3 is the 95 percent
confidence interval for each parameter. As shown in Table 7-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
7.2.3 Composite Back Trajectories for Sampling Days
Figure 7-3 is a composite back trajectory map for the Colorado monitoring site for the
days on which samples were collected. Each line represents the 24-hour trajectory along which a
parcel of air traveled toward the monitoring site on a sampling day. Each concentric circle
around the site in Figures 7-3 represents 100 miles.
7-6
-------
Table 7-3. Average Meteorological Conditions near the Colorado Monitoring Site
Site
GPCO
Closest NWS
Station and
WBAN
Walker Field
Airport
23066
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
68.49
±5.01
66.15
±2.30
Average
Temperature
(»F)
55.75
±4.65
53.79
±2.11
Average
Dew Point
Temperature
(°F)
29.25
±2.71
28.27
±1.28
Average
Wet Bulb
Temperature
(OF)
42.74
±3.07
41.41
±1.42
Average
Relative
Humidity
(%)
43.88
±4.36
45.38
±1.97
Average
Sea Level
Pressure
(mb)
1014.24
± 1.84
1015.01
±0.85
Average
Scalar Wind
Speed
(kt)
6.92
±0.71
6.45
±0.29
BOLD = EPA-designated NATTS Site
-------
Figure 7-3. Composite Back Trajectory Map for GPCO
00
-------
Observations from Figure 7-3 include the following:
• Back trajectories originated from a variety of directions at GPCO. However,
trajectories originated from a direction with an easterly component less frequently
than other directions.
• The 24-hour air shed domain for GPCO was somewhat smaller in size than other
monitoring sites. The furthest away a trajectory originated was central Idaho, or
nearly 500 miles away. However, most trajectories originated within 300 miles of the
site.
7.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at Walker Field near GPCO were uploaded
into a wind rose software program, WRPLOT (Lakes, 2006) to produce customized wind roses.
A wind rose shows the frequency of wind directions on a 16-point compass, and uses different
shading to represent wind speeds. Figure 7-4 is the wind rose for the Colorado monitoring site
on days that samples were collected.
Figure 7-4. Wind Rose for GPCO Sampling Days
15%
7-9
-------
Observations from Figure 7-4 for GPCO include the following:
• Easterly, east-southeasterly, and southeasterly winds were prevalent near GPCO.
• Calm winds were observed for approximately 14 percent of the hourly wind
measurements.
• Winds exceeding 11 knots made up approximately 17 percent of observations.
7.3 Pollutants of Interest
"Pollutants of interest" were determined for the monitoring site in order to allow analysts
and readers to focus on a risk-based subset of pollutants. The pollutants of interest for the
Colorado monitoring site were identified using the EPA risk screening process described in
Section 3.2. In brief, each pollutant's measured concentration was compared to its associated
risk screening value. If the daily concentration was greater than the risk screening value, then
the measured concentration "failed the screen." Pollutants of interest are those for which the
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 7-4 presents the pollutants that failed at least one screen at the Colorado
monitoring site and highlights the site's pollutants of interest (shaded). GPCO sampled for
VOC, carbonyls, and hexavalent chromium.
Observations from Table 7-4 include the following:
• Thirteen pollutants with a total of 434 measured concentrations failed at least one
screen for GPCO.
• The following pollutants were identified as pollutants of interest for GPCO:
acetaldehyde, acrolein, benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde,
and tetrachloroethylene.
• Of the seven pollutants of interest, acetaldehyde, acrolein, benzene, 1,3-butadiene,
and carbon tetrachloride failed 100 percent of screens for GPCO.
• Seventy nine percent of measured detections failed screens (of the pollutants that
failed at least one screen) for GPCO.
7-10
-------
Table 7-4. Comparison of Measured Concentrations and EPA Screening Values for the
Colorado Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Grand Junction, Colorado - GPCO
Acetaldehyde
Benzene
Carbon Tetrachloride
Formaldehyde
1,3 -Butadiene
Acrolein
Tetrachloroethylene
/>-Dichlorobenzene
Acrylonitrile
1 ,2-Dichloroethane
1 ,2-Dibromoethane
Hexachloro- 1 , 3 -butadiene
Hexavalent Chromium
Total
64
62
62
62
62
61
40
10
6
2
1
1
1
434
64
62
62
64
62
61
61
57
6
2
1
1
43
546
100.00
100.00
100.00
96.88
100.00
100.00
65.57
17.54
100.00
100.00
100.00
100.00
2.33
79.49
14.75
14.29
14.29
14.29
14.29
14.06
9.22
2.30
1.38
0.46
0.23
0.23
0.23
14.75
29.03
43.32
57.60
71.89
85.94
95.16
97.47
98.85
99.31
99.54
99.77
100.00
7.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Colorado monitoring site. The averages presented are provided for the pollutants of
interest for the monitoring site. Complete site-specific statistical summaries are provided in
Appendices J through O. In addition, concentration averages for select pollutants are presented
from previous sampling years in order to characterize concentration trends at the site, where
applicable.
7.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
7-11
-------
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 7-5, where applicable.
Observations for GPCO from Table 7-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (4.02 ± 0.33 |ig/m3), acetaldehyde (2.79 ± 0.26 |ig/m3), and benzene
(1.46 ± 0.20 jig/m3). The annual averages for these pollutants were the same as their
respective daily averages.
• As shown in Tables 4-9 and 4-11, of the program-level pollutants of interest, the daily
average concentration of the following pollutants for GPCO were among the 10
highest average concentrations for all NATTS and UATMP sites: acetaldehyde,
benzene, 1,3-butadiene, formaldehyde, and tetrachloroethylene.
• Benzene and 1,3-butadiene concentrations were higher in the autumn and winter at
GPCO.
Table 7-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Colorado Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(Hg/m3)
Spring
Average
(jig/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Ug/m3)
Annual
Average1
(Ug/m3)
Grand Junction, Colorado - GPCO
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
Tetrachloroethylene
64
61
62
62
62
64
61
64
62
62
62
62
64
62
2.79
±0.26
0.65
±0.10
1.46
±0.20
0.16
±0.03
0.53
±0.03
4.02
±0.33
0.32
±0.06
2.13
±0.41
0.58
±0.24
1.89
±0.53
0.24
±0.07
0.49
±0.05
3.90
±0.44
0.40
±0.11
2.62
±0.57
0.59
±0.26
1.03
±0.19
0.11
±0.02
0.56
±0.07
2.91
±0.67
0.25
±0.09
3.48
±0.44
0.70
±0.11
1.13
±0.20
0.10
±0.02
0.53
±0.06
4.25
±0.53
0.18
±0.05
2.78
±0.43
0.71
±0.14
1.88
±0.40
0.20
±0.06
0.53
±0.07
4.98
±0.47
0.47
±0.18
2.79
±0.26
0.64
±0.10
1.46
±0.20
0.16
±0.03
0.53
±0.03
4.02
±0.33
0.32
±0.06
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
7.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
7-12
-------
described in Section 3.6.4. GPCO has not sampled continuously for five years as part of the
National Monitoring Program; therefore, the trends analysis was not conducted.
7.5 Pearson Correlations
Table 7-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for GPCO from Table 7-6 include the following:
• A strong negative correlation was calculated between 1,3-butadiene and the average
temperature and wet bulb temperature, indicating that as temperature and moisture
content increase, concentrations of 1,3-butadiene decrease. This supports the
seasonal average trends discussed in Section 7.4.1.
• Strong positive correlations were calculated between 1,3-butadiene and benzene and
sea level pressure. This indicates that as pressure increases, concentrations of these
pollutants increase.
• Most of the pollutants of interest exhibited weak negative correlations with wind
speed, suggesting that concentrations of the pollutants of interest may increase as
wind speeds decrease.
7.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
7.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Colorado
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
7-13
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Table 7-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Colorado
Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Grand Junction, Colorado - GPCO
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
Tetrachloroethylene
64
61
62
62
62
64
61
0.47
0.17
-0.37
-0.48
0.09
0.12
-0.24
0.45
0.13
-0.42
-0.52
0.11
0.07
-0.26
0.11
0.14
-0.34
-0.48
0.16
0.19
-0.28
0.35
0.14
-0.43
-0.55
0.15
0.10
-0.27
-0.55
-0.11
0.30
0.33
-0.03
0.03
0.08
0.00
0.18
0.55
0.60
-0.06
0.23
0.35
-0.25
-0.01
-0.43
-0.44
-0.05
-0.25
-0.32
-------
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 7-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 7-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• All of the seasonal averages of acrolein exceeded the intermediate MRL.
• Acrolein has no chronic MRL. Therefore, a chronic risk comparison could not be
conducted.
7.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Colorado monitoring site and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk from NATA and calculating cancer and noncancer
surrogate risk estimates approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 7-8. Data
from NATA are presented for the census tract where the monitoring site is located. GPCO is
located in census tract ID 08077000800, for which the population was 5,845, and represented
about five percent of the 2000 county population. The pollutants of interest for GPCO are
bolded.
Observations for GPCO from Table 7-8 include the following:
• The pollutants with the highest concentrations according to NATA were
formaldehyde, acetaldehyde, and benzene
• The pollutants with the highest cancer risks according to NATA were benzene,
carbon tetrachloride, and 1,2-dibromoethane.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (1.04).
7-15
-------
Table 7-7. MRL Risk Screening Assessment Summary for the Colorado Monitoring Site
Site
GPCO
Method
TO-15
Pollutant
Acrolein
ATSDR
Acute
MRL
(Hg/m3)
7.00
#of
Exceedances/
#of
Measured
Detections
0/61
ATSDR
Intermediate
MRL
(Hg/m3)
0.09
Winter
Average
(jig/m3)
0.58
±0.24
Spring
Average
(Hg/m3)
0.59
±0.26
Summer
Average
(jig/m3)
0.70
±0.11
Autumn
Average
(Hg/m3)
0.71
±0.14
ATSDR
Chronic
MRL
(Hg/m3)
-
Annual
Average1
(Hg/m3)
0.64
±0.10
~ = an MRL risk factor is not available
BOLD = EPA-designated NATTS Site
BOLD = exceedance of the intermediate or chronic MRL
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 7-8. Cancer and Noncancer Risk Summary for the Monitoring Site in Colorado
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Hg/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Hg/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Grand Junction, Colorado (GPCO) - Census Tract ID 08077000800
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
1 ,2-Dibromoethane
£>-Dichlorobenzene
1 ,2-Dichloroethane
Formaldehyde
Hexachloro- 1 ,3 -butadiene
Hexavalent Chromium
Tetrachloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.00022
0.000011
0.000026
5.5E-09
0.000022
0.012
0.000005
0.009
0.00002
0.002
0.03
0.002
0.04
0.0008
0.8
2.4
0.0098
0.09
0.0001
0.27
0.57
0.02
<0.01
0.56
0.04
0.21
0.01
0.01
0.02
0.73
<0.01
<0.01
0.07
1.27
—
0.15
4.38
1.25
3.18
2.92
0.13
0.63
0.01
0.03
0.03
0.42
0.06
1.04
<0.01
0.01
0.02
0.01
0.01
0.01
0.01
0.07
O.01
O.01
O.01
2.79 ±0.26
0.64 ±0.10
0.04 ±0.01
1.46 ±0.20
0.16 ±0.03
0.53 ±0.03
0.05 ±0.01
0.07 ±0.01
0.04 ±0.01
4.02 ±0.33
0.19 ±O.01
O.01±O.01
0.32 ±0.06
5.59
—
2.43
10.21
4.77
7.94
11.30
0.74
1.11
0.02
4.26
0.19
1.58
0.31
32.22
0.02
0.05
0.08
0.01
0.06
0.01
0.01
0.41
O.01
O.01
O.01
— = a URE or RfC is not available
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
• The pollutants with the highest annual averages were formaldehyde, acetaldehyde,
and benzene, which were all an order of magnitude higher than the NATA-modeled
concentrations.
• The pollutants with the highest cancer risk approximations were 1,2-dibromoethane,
benzene, and carbon tetrachloride. 1,2-Dibromoethane was detected once at GPCO.
• Similar to the NATA results, acrolein was the only pollutant with a noncancer risk
approximation greater than 1.0. However, the noncancer risk approximation (32.22)
was an order of magnitude higher than NATA.
7.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 7-9 and 7-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 7-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer surrogate risk approximations (in-a-million), as calculated from the annual averages.
Table 7-10 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on the site's annual averages are limited to those pollutants
for which the monitoring site sampled. As discussed in Section 7.3, GPCO sampled for VOC,
carbonyl compounds, and hexavalent chromium. In addition, the cancer and noncancer surrogate
risk approximations are limited to those sites sampling for a long enough period for annual
averages to be calculated.
Observations from Table 7-9 include the following:
• Benzene, formaldehyde, and dichloromethane were the highest emitted pollutants
with cancer UREs in Mesa County.
7-18
-------
Table 7-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Colorado
VO
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Grand Junction, Colorado (GPCO) - Mesa County
Benzene
Formaldehyde
Dichloromethane
Acetaldehyde
1,3 -Butadiene
Naphthalene
POM, Group 2
Tetrachloroethylene
Trichloroethylene
Vinyl chloride
155.92
59.09
20.67
19.25
15.26
3.80
2.95
2.91
1.49
1.19
Benzene
1,3 -Butadiene
Arsenic, PM
Hexavalent Chromium
POM, Group 2
Naphthalene
Acrylonitrile
Acetaldehyde
1 , 1 ,2,2-Tetrachloroethane
POM, Group 5
1.22E-03
4.58E-04
2.01E-04
1.62E-04
1.62E-04
1.29E-04
5.94E-05
4.23E-05
2.81E-05
2.44E-05
1,2-Dibromoethane
Benzene
Carbon Tetrachloride
Acetaldehyde
1,3 -Butadiene
Hexachloro- 1 ,3 -butadiene
Acrylonitrile
Tetrachloroethylene
1,2-Dichloroethane
/>-Dichlorobenzene
11.30
10.21
7.94
5.59
4.77
4.26
2.43
1.58
1.11
0.74
-------
Table 7-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Colorado
to
o
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Grand Junction, Colorado (GPCO) - Mesa County
Toluene
Xylenes
Benzene
Hexane
Formaldehyde
Methanol
Ethylbenzene
Hydrogen fluoride
Dichloromethane
Acetaldehyde
390.17
233.73
155.92
60.09
59.09
55.34
53.93
36.34
20.67
19.25
Acrolein
1,3 -Butadiene
Manganese, PM
Formaldehyde
Benzene
Xylenes
Acetaldehyde
Arsenic, PM
Cyanide Compounds, gas
Naphthalene
14,2376.52
7,630.08
6,088.13
6,029.49
5,197.47
2,337.29
2,138.62
1,560.78
1,466.67
1,265.16
Acrolein
Formaldehyde
Acetaldehyde
1,3 -Butadiene
1 ,2-Dibromoethane
Benzene
Acrylonitrile
Carbon Tetrachloride
Hexachloro- 1 ,3 -butadiene
Tetrachloroethylene
32.22
0.41
0.31
0.08
0.06
0.05
0.02
0.01
<0.01
0.01
-------
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) were benzene, 1,3-butadiene, and arsenic.
• Five of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• 1,2-Dibromoethane was the pollutant with the highest cancer surrogate risk
approximation, yet appeared on neither emissions-based list. However, the low
detection rate indicates that this pollutant is rarely detected in ambient air near GPCO.
• Benzene, which ranked highest on both emissions-based lists, had the second highest
cancer surrogate risk approximation.
Observations from Table 7-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Mesa County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, 1,3-butadiene, and manganese.
• Three of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Acrolein, which had the highest noncancer risk approximation, also had the highest
toxicity-weighted emissions.
7.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest for GPCO were acetaldehyde, acrolein, benzene, 1,3-
butadiene, carbon tetrachloride, formaldehyde, and tetrachloroethylene.
»«» Formaldehyde had the highest daily average concentration for GPCO.
»«» All four seasonal averages of acrolein exceeded the intermediate MRL health
benchmark.
7-21
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8.0 Site in Washington, B.C.
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Washington, D.C., and integrates these
concentrations with emissions, meteorological, and risk information.
8.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The WADC site is located in
the Washington-Arlington-Alexandria, DC-VA-MD-WV MSA. Figure 8-1 is a composite
satellite image retrieved from Google™ Maps showing the monitoring site in its urban location.
Figure 8-2 identifies point source emission locations within 10 miles of the site as reported in the
2002 NEI for point sources. Table 8-1 describes the area surrounding each monitoring site and
provides supplemental geographical information such as land use, location setting, and locational
coordinates.
Figure 8-1 shows that the WADC monitoring site is located in an open field at the
southeast of end of the McMillian Water Reservoir in Washington, D.C. It is also located near
several heavily traveled roadways. The site is located in a commercial area, and is surrounded
by a hospital, a cemetery, and a university. As Figure 8-2 shows, WADC is surrounded by a
handful of point sources, with very few actually residing in the District itself. Several of these
emission sources have processes utilizing fuel combustion or utility boilers, although an electric,
gas, and sanitary service facility resides fairly close to the WADC monitoring site.
Table 8-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Washington, D.C. monitoring site. District-level vehicle registration and population data were
obtained from the Federal Highway Administration and the U.S. Census Bureau. Table 8-2 also
includes a vehicle registration to county population ratio (vehicles per person). In addition, the
population within 10 miles of the site is presented. An estimate of 10-mile vehicle registration
3-1
-------
Figure 8-1. Washington, B.C. (WADC) Monitoring Site
oo
to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 8-2. NEI Point Sources Located Within 10 Miles of WADC
Ou* la fKtlty dtfiwtj and w*oct»oo tht icttl tadMxt
may ntf rtprfl^eoH afl (acilflw* • Liquids Distribution Industrial Facilrty (1)
County boundary
P Miscellaneous Processes Industrial Facility (2)
« Paper & All led Products (1)
ft Printing & Publtshing Facilrty (1)
5 Surface Coating Processes Industrial Facility (2)
» Utility Boilers (3)
Vfeste Tfeatment a Disposal Industrial Facility (1)
8-3
-------
Table 8-1. Geographical Information for the Washington, D.C. Monitoring Site
Site
Code
WADC
AQS Code
11-001-0043
Location
Washington
D.C.
County
Flictrirt
Of
Columbia
]Micro- or
Metropolitan
Statistical Area
Washington-
Arlington-
Alexandria, DC-
VA-MD-WV
Latitude
and
Longitude
38.921847,
77.013178
Land Use
Commercial
Location
Setting
Urban/City
Center
Description of the
Immediate Surroundings
WADC is located in an open field at the southeast of
end of the McMillian Water Reservoir in
Washington, D.C. It is also located near several
heavily traveled roadways. The site is surrounded by
a hospital, a cemetery, and a university. WADC is a
PAMS site.
BOLD = EPA-designated NATTS Site
oo
-------
Table 8-2. Population, Motor Vehicle, and Traffic Information for the Washington, D.C.
Monitoring Site
Site
WADC
2007
Estimated
County
Population
588,292
Number
of
Vehicles
Registered
230,000
Vehicles
per Person
(Registration:
Population)
0.37
Population
Within
10 Miles
1,860,974
Estimated
10 mile Vehicle
Ownership
693,106
Annual
Average
Traffic
Data1
36,800
VMT
(thousands)
97,009
1 Daily Average Traffic Data reflects 2002 data from District DOT
BOLD = EPA-designated NATTS Site
was calculated by applying the county-level vehicle registration to population ratio to the 10-
mile population surrounding the monitoring site. Table 8-2 also contains annual average daily
traffic information, as well as the year of the traffic data estimate and the source from which it
was obtained. Finally, Table 8-2 presents the daily VMT for the urban area.
Observations from Table 8-2 include the following:
• Washington, D.C.'s population ranked 20th compared to all counties with NATTS or
UATMP sites. However, its 10-mile population ranked sixth.
• The District-level vehicle registration ranked 25th compared to all counties with
NATTS or UATMP sites, while its 10-mile ownership estimated ranked 16th.
• The vehicle per person ratio was the third lowest compared to other NATTS or
UATMP sites.
• The traffic volume experienced near WADC ranked mid-range compared to other
monitoring sites. The traffic estimate used came from the intersection of Michigan
Avenue and North Capital Street.
• The District area VMT ranked ninth among urban areas with UATMP or NATTS
sites.
8.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Washington, D.C. on sampling days, as well as over the course of the year.
8.2.1 Climate Summary
Located on the Potomac River that divides Virginia and Maryland, the capital enjoys all
four seasons, although its weather is somewhat variable. Summers are warm and often humid, as
8-5
-------
southerly winds prevail, which can be accentuated by the urban heat island effect. Winters are
typical of the Mid-Atlantic region, where cool, blustery air masses are common followed by a
fairly quick return to mild temperatures. Precipitation is evenly distributed across the seasons
(Ruffner and Bair, 1987).
8.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Ronald Reagan Washington National Airport (WBAN 13743).
Table 8-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 8-3 is the 95 percent
confidence interval for each parameter. As shown in Table 8-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
8.2.3 Composite Back Trajectories for Sampling Days
Figure 8-3 is a composite back trajectory map for the Washington, D.C. monitoring site
for the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the site in Figure 8-3 represents 100 miles.
Observations from Figure 8-3 include the following:
• Back trajectories originated from a variety of directions at WADC. However, there
was a lack of trajectories originating from the south.
-------
Table 8-3. Average Meteorological Conditions near the Washington, D.C. Monitoring Site
Site
WADC
Closest NWS
Station and
WBAN
Ronald Reagan
Washington
National
Airport
13743
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
66.56
±4.71
66.99
±1.96
Average
Temperature
(op)
58.62
±4.37
58.87
±1.80
Average
Dew Point
Temperature
(°F)
44.72
±4.63
44.11
±1.91
Average
Wet Bulb
Temperature
(»F)
51.68
±3.99
51.55
±1.63
Average
Relative
Humidity
(%)
62.89
±3.15
61.25
±1.43
Average
Sea Level
Pressure
(mb)
1018.44
± 1.60
1018.10
±0.69
Average
Scalar Wind
Speed
(kt)
6.89
±0.72
7.26
±0.29
BOLD = EPA-designated NATTS Site
oo
-------
Figure 8-3. Composite Back Trajectory Map for WADC
00
-------
• The 24-hour air shed domain for WADC was similar in size to other monitoring sites.
The furthest away a trajectory originated was northern Maine, or nearly 700 miles
away. However, most trajectories originated within 400 miles of the site.
8.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at Ronald Reagan Washington National
Airport near WADC were uploaded into a wind rose software program, WRPLOT (Lakes, 2006)
to produce customized wind roses. A wind rose shows the frequency of wind directions on a
16-point compass, and uses different shading to represent wind speeds. Figure 8-4 is the wind
rose for the Washington, D.C. monitoring site on days that samples were collected.
Figure 8-4. Wind Rose for WADC Sampling Days
NORTH"'--.
20%
WEST I
WIND SPEED
(Knots)
n -22
• 17 - 21
^| 11 • 17
^| 7- 11
n 4.7
• 2- 4
Calms: 10.14%
Observations from Figure 8-4 for WADC include the following:
• Southerly winds were prevalent (19 percent of wind observations), followed by
southwesterly winds (11 percent).
• Calm winds were observed for approximately 10 percent of the hourly measurements.
8-9
-------
• Winds exceeding 11 knots made up 13 percent of observations. The strongest winds
originated from the northwest.
8.3 Pollutants of Interest
"Pollutants of interest" were determined for the monitoring site in order to allow analysts
and readers to focus on a risk-based subset of pollutants. The pollutants of interest for the
Washington, D.C. monitoring site were identified using the EPA risk screening process
described in Section 3.2. In brief, each pollutant's measured concentration was compared to its
associated risk screening value. If the daily concentration was greater than the risk screening
value, then the measured concentration "failed the screen." Pollutants of interest are those for
which the individual pollutant's total failed screens contribute to the top 95 percent of the site's
total failed screens. Table 8-4 presents the results of the risk screening process and highlights
the site's pollutants of interest (shaded).
Table 8-4. Comparison of Measured Concentrations and EPA Screening Values for the
Washington, D.C. Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Washington, D.C. - WADC
Hexavalent Chromium
Total
0
0
33
33
0.00
0.00
0.00
0.00
Observations from Table 8-4 include the following:
• WADC sampled for hexavalent chromium only.
• Hexavalent chromium was detected in 33 samples and did not fail any screens.
• In order to facilitate analysis, hexavalent chromium is considered WADC's pollutant
of interest.
8.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Washington, D.C. monitoring site. The averages presented are provided for the pollutants
of interest for the monitoring site. Complete site-specific statistical summaries are provided in
8-10
-------
Appendices J through O. In addition, concentration averages for select pollutants are presented
from previous sampling years in order to characterize concentration trends at the site, where
applicable.
8.4.1 2007 Concentration Averages
Daily, seasonal, and annual averages were calculated for the pollutants of interest, as
described in Section 3.3. The daily average of a particular pollutant is simply the average
concentration of all measured detections. If there were at least seven measured detections within
each season, then a seasonal average was calculated. The seasonal average includes 1/2 MDLs
substituted for all non-detects. Finally, the annual average is the average concentration of all
measured detections and 1/2 MDLs substituted for non-detects. Annual averages were
calculated for monitoring sites where sampling began no later than February and ended no earlier
than November, and where the completeness was greater than or equal to 85 percent. Daily,
seasonal, and annual averages are presented in Table 8-5, where applicable. The averages
presented in Table 8-5 are shown in ng/m3 for ease of viewing.
Table 8-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Washington, D.C. Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average1
(ng/m3)
Washington, D.C. - WADC
Hexavalent Chromium
33
60
0.012
± 0.003
NR
0.008
± 0.003
0.010
± 0.004
0.010
± 0.004
0.008
± 0.002
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for WADC from Table 8-5 include the following:
• The daily average concentration of hexavalent chromium was slightly higher than the
annual average concentration(0.012 ± 0.003 ng/m3 vs. 0.008 ± 0.002 ng/m3), which
illustrates the effect of the substitution of !/2 MDL.
• Seasonal averages of hexavalent chromium were fairly similar to each other. A
winter average could not be calculated due to the low number of detections.
8-11
-------
8.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. WADC has not sampled continuously for five years as part of the
National Monitoring Program; therefore, the trends analysis was not conducted.
8.5 Pearson Correlations
Table 8-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for WADC from Table 8-6 include the following:
• All of the correlations for WADC were weak.
8.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
8.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the
Washington, D.C monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where
available. As described in Section 3.3, acute risk results from exposures of 1 to 14 days;
intermediate risk results from exposures of 15 to 364 days; and chronic risk results from
exposures of one year or greater. The preprocessed daily measurements of the pollutants of
interest were compared to the acute MRL; the seasonal averages were compared to the
intermediate MRL; and the annual averages were compared to the chronic MRL. None of the
measured detections or average concentrations of hexavalent chromium at the WADC
monitoring site exceeded any of the MRL risk values.
8-12
-------
Table 8-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
Washington, D.C. Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Washington, D.C. - WADC
Hexavalent Chromium
33
0.07
0.11
0.16
0.14
0.14
-0.19
-0.18
oo
-------
8.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants of interest and where the annual average concentrations could be
calculated, risk was further examined by reviewing cancer and noncancer risk estimates from
NATA and calculating cancer and noncancer surrogate risk approximations (refer to
Section 3.6.5 regarding the criteria for an annual average and how cancer and noncancer
surrogate risk approximations are calculated). Concentration and risk estimates from NATA,
annual averages, cancer UREs and/or noncancer RfCs, and cancer and noncancer surrogate risk
approximations are presented in Table 8-7. The data from NATA are presented for the census
tract where the monitoring site is located. The census tract ID for WADC is 11001003400, for
which the population was 2,707, and represented less than one percent of the District population
in 2000. The pollutants of interest are bolded.
Observations for WADC from Table 8-7 include the following:
• The modeled concentration for hexavalent chromium from NATA was less than
0.01 |ig/m3, as was the annual average.
• Cancer and noncancer risks for hexavalent chromium according to NATA were low.
This was also true of the cancer and noncancer surrogate risk approximations.
8.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 8-8 and 8-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 8-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer surrogate risk approximations (in-a-million,) as calculated from the annual averages.
Table 8-9 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
8-14
-------
Table 8-7. Cancer and Noncancer Risk Summary for the Monitoring Site in Washington, D.C.
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Washington, B.C. (WADC) - Census Tract ID 11001003400
Hexavalent Chromium
0.012
0.0001
<0.01
0.34
<0.01
<0.01
±<0.01
0.10
<0.01
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
oo
-------
oo
Table 8-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Washington, D.C.
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Washington, B.C. (WADC)
Benzene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
1,3 -Butadiene
Trichloroethylene
£>-Dichlorobenzene
Dichloromethane
Naphthalene
POM, Group 2
219.82
124.36
43.67
35.16
26.54
16.03
12.17
8.85
5.70
1.43
Benzene
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
Hexavalent Chromium
£>-Dichlorobenzene
Arsenic, PM
Acetaldehyde
POM, Group 2
Ethylene oxide
1.71E-03
7.96E-04
2.07E-04
1.94E-04
1.58E-04
1.34E-04
1.12E-04
9.61E-05
7.87E-05
4.87E-05
Hexavalent Chromium 0.10
-------
oo
Table 8-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Washington, D.C.
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Washington, B.C. (WADC)
Toluene
Methyl tert- butyl ether
Xylenes
Benzene
Methanol
Formaldehyde
Ethylbenzene
Hexane
1,1,1 -Trichloroethane
Ethylene glycol
494.98
437.77
344.77
219.82
198.96
124.36
75.64
63.93
60.44
48.22
Acrolein
1,3 -Butadiene
Formaldehyde
Chlorine
Benzene
Cyanide Compounds, gas
Acetaldehyde
Xylenes
Naphthalene
Toluene
335,237.81
13,271.78
12,690.12
8,575.00
7,327.25
7,313.33
4,851.97
3,447.74
1,900.71
1,237.45
Hexavalent Chromium <0.01
-------
for which each respective site sampled. As discussed in Section 8.3, WADC sampled for
hexavalent chromium only. In addition, the cancer and noncancer surrogate risk approximations
are limited to those sites sampling for a long enough period for annual averages to be calculated.
Observations from Table 8-8 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in the District of Columbia.
• Benzene was also the pollutant with the highest toxi city-weighted emissions (of the
pollutants with cancer UREs), followed by 1,3-butadiene and tetrachloroethylene.
• Seven of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Hexavalent chromium, which was the only pollutant sampled for at WADC, had the
fifth highest toxicity-weighted emissions for the District of Columbia. This pollutant
did not appear on the list of highest emitted pollutants.
Observations from Table 8-9 include the following:
• Toluene, methyl fert-butyl ether, and xylenes were the highest emitted pollutants with
noncancer RfCs in the District of Columbia.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, 1,3-butadiene, and formaldehyde.
• Four of the highest emitted pollutants in the District of Columbia also had the highest
toxicity-weighted emissions.
• Hexavalent chromium did not appear on the list of highest emitted pollutants or the
list of highest toxicity-weighted emissions for pollutants with a noncancer toxicity
factor.
8.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Hexavalent chromium did not fail any screens for WADC. However, it was
considered a pollutant of interest in order to allow data analyses to be conducted.
»«» Hexavalent chromium did not exceed any of the MRL health benchmarks.
8-18
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9.0 Sites in Florida
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS and UATMP sites in Florida, and integrates these
concentrations with emissions, meteorological, and risk information.
9.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. The Florida sites are
located in several different urban areas. Sites located in the Tampa-St. Petersburg-Clearwater,
FL MSA include AZFL, GAFL, SKFL, and SYFL. FLFL is located in the Miami-Fort
Lauderdale-Pompano Beach, FL MSA. ORFL is located in the Orlando-Kissimmee, FL MSA.
Figures 9-1 through 9-6 are composite satellite images retrieved from Google™ Maps showing
the monitoring sites in their urban and rural locations. Figures 9-7 through 9-9 identify point
source emission locations within 10 miles of each site as reported in the 2002 NEI for point
sources. Table 9-1 describes the area surrounding each monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
AZFL is located in Azalea Park, in St. Petersburg. Figure 9-1 shows that the area
surrounding AZFL consists of mixed land use, including residential, commercial, and industrial
properties. Heavily traveled roadways are located less than a mile from the monitoring site.
AZFL is just over a mile east of Boca Ciega Bay.
GAFL is located near the east side of the Gandy Bridge on Highway 92 in Tampa.
Figure 9-2 shows that GAFL is located on a small peninsula on old Tampa Bay. The setting is
suburban and the surrounding area has mixed land use.
SKFL is located in Pinellas Park, north of St. Petersburg. This site is on the property of
Skyview Elementary School near 86th Avenue North. Figure 9-3 shows that SKFL is located in a
residential area. Population exposure is the purpose behind monitoring in this location.
9-1
-------
to
Figure 9-1. St. Petersburg, Florida (AZFL) Monitoring Site
' I
« i
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 9-2. Tampa, Florida (GAFL) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 9-3. Pinellas Park, Florida (SKFL) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 9-4. Plant City, Florida (SYFL) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 9-5. Winter Park, Florida (ORFL) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 9-6. Davie, Florida (FLFL) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 9-7. NEI Point Sources Located Within 10 Miles of the Tampa/
St. Petersburg, Florida Monitoring Sites
Hat. Due ID f»nl« j derrefl j irid ajUocalicn. Bic
AZFL UATMP site
GAFL UATMP site
SKFL NATTS site
SYFL WATTS srte
Source Category Group {No. of Facilities)
« Automotive Repair, Services, & Parking ft)
Business Services Facility (1)
c Chemicals & AWied Products Facility (10)
2 Electrical 5 Electronic Equipment Facility (51
F Fuel Combustion Industrial Facility (27)
i Incineration Industrial Facility (6)
J Industrial Machinery & Equipment Facility (1)
- instruments & Related Products Facility (2)
L Liquids Retribution Industrial Facility (It)
s Lumber & Wood Products Facility (3)
,-- Medical Dental & Hospital Equipment and Supplies
6 Mineral Products Processing industrial Facility (9)
P Miscellaneous Processes Industrial Facility (3)
* Miscellaneous Repair Services (1)
County boundary
• National security & international Affairs (1 ;<
i Non-ferrous Metals Processing Industrial Facility (2)
a Papers Allied Products (1)
> Pharmaceutical Production Processes Industrial Facility ( 1 )
v Potynws & Restns Production Industrial Facility (6)
n Printing & Publishing Facility (1>
• Production ol Inomanic Chemicals Industrial Facility ( 1 }
y Rubber 5 Miscellanedus Plastic Products Facility (1)
U Stone, Clay, Glass, & Concrete Products (2)
s Surface Coahng Processes Industrial Facility (31)
+ Transportation by Air ( 1 )
(2) 8 UWity Boners (4)
•• V\flste Treatment & Disposal Industrial Facility (14)
r YMiolesale Trade (3)
9-8
-------
Figure 9-8. NEI Point Sources Located Within 10 Miles of ORFL
<• i »
\ ' i—"/""
7F
i rt
Legend
•ff ORFL UATMP site
10 mile radius
Count,' boundary
Source Category Group (No. of Facilities)
Z Bedrical & Electronic EciuipmerU Facility (1)
D Fat* icated Metal Products Facility (2)
f Fuel Combustion Industrial Facility (6)
j Industrial Machinery & Equipment Facility (1)
x Miscellaneous Manufacturing lndus(nes(1}
V .Polymers & Resins Production Industrial Facility (3)
t Rubber & M Iscellarwous Plastic PiocRels Facility (2)
S Surface Coaling Processes Industrial Facility (1)
T Transportation Equipment (1)
T Waste Trealment & Disposal Industrial Facility ("}
7 Unknown (2)
I'-^.i Vi 81*30TO^V WIVM
Hot« Due 10 raaKy domity and coUocallcn. Ui» loUl buUiln
ilw «r»i ol rti*i*-sl
9-9
-------
Figure 9-9. NEI Point Sources Located Within 10 Miles of FLFL
•
KTItnrw
Hot« Due 10 raaKy domity and coiiocallcn. Ui» loUl buUiln
ih* ai» • ol ini*i*-(l
4 tnf/nt* rtpttW *l ttettaet
Legend
•& FLFL UATMP site
10 mite radius
_j County toundary
Source Category Group {No. of Facilities)
* Automotive Repaw, Service*. & Parking (4)
Ctemicate & Aided Products Facility (3)
Electrical & Electronic Equipment Facility (1 )
Incineralion Industrial Facility (1 )
Liquids Distribution Industrial Facility (8)
PtwmaceuUcal Produclkwi Processes Industrial Facility (1 )
Polymers & Resins Producton Industrial Facility (2)
Surface Coating Processes I rtdustnal Facility (8)
Utility Boilers | ?•)
C
I
9-10
-------
Table 9-1. Geographical Information for the Florida Monitoring Sites
Site
Code
AZFL
FLFL
AQS Code
12-103-0018
12-011-1002
Location
Ct
OL.
Petersburg
Davie
County
Pinellas
Broward
Micro- or
Metropolitan
Statistical Area
Tampa-St.
Petersburg-
Clearwater, FL
Lauderdale-
Pompano Beach,
Latitude
and
Longitude
97 7XSSS6
^ I . I O J J JU,
-82.74
26.08534,
-80.24104
Land Use
Residential
Commercial
Location
Setting
Suburban
Suburban
Description of the
Immediate Surroundings
A neighborhood spatial scale of representativeness
characterizes this monitoring site selected for the
Tampa Bay pilot project. This monitor is sited in an
area of high population density with uniform mixed
land use, consisting of residential, commercial, and
industrial properties. Major point sources are located
approximately 2 to 10 miles from the monitoring site.
In addition, this site is at least 150 meters from major
roadways. However, given the proximity of motor
vehicle traffic it is expected that mobile sources will
contribute appreciably to the measured samples.
The site is located on the campus of the University of
Florida, Agricultural Research Center in Davie,
Florida. It is located in a generally residential area
that is surrounded by 4 major thoroughfares in the
county (~1 mile from 1-595, ~2 miles from the Florida
Turnpike, ~6 miles from 1-95, and ~6 miles from I-
75). It is located ~ 6 miles from the Ft. Lauderdale-
Hollywood International Airport and ~9 miles from
Port Everglades. It is in an area generally
representative of the ambient air conditions
experienced throughout the county. It is expected that
this site will become an NCore type II site in the near
future.
BOLD = EPA-designated NATTS Site
-------
Table 9-1. Geographical Information for the Florida Monitoring Sites (Continued)
Site
Code
GAFL
ORFL
SKFL
AQS Code
12-057-1065
12-095-2002
12-103-0026
Location
Tampa
Winter Park
Pinellas
Park
County
Hills-
borough
Orange
Pinellas
Micro- or
Metropolitan
Statistical Area
Tampa-St.
Petersburg-
Clearwater, FL
Orlando-
Kissimmee, FL
Tampa-St.
Petersburg-
Clearwater, FL
Latitude
and
Longitude
27.892222,
-82.538611
28.596444,
-81.362444
27.850041,
-82.714590
Land Use
Commercial
Commercial
Residential
Location
Setting
Suburban
Urban/City
Center
Suburban
Description of the
Immediate Surroundings
A neighborhood spatial scale of representativeness
characterizes this monitoring site selected for the
Tampa Bay Region Air Toxics Study Monitoring
Stations (TBRATS) pilot project. This monitor is
sited in an area of high population density with
uniform mixed land use, consisting of residential,
commercial, and industrial properties. Major point
sources are located greater than one mile from the
monitoring site. Since the emission points from these
sources are elevated and not proximate to the monitor,
concentrations measured during this study should not
be dominated by a single source. In addition, this site
is at least 150 meters from major roadways. However,
given the proximity of motor vehicle traffic, mobile
sources are expected to contribute appreciably to the
measured samples.
The site is an Urban/Neighborhood spatial scale site to
determine the concentrations of the EPA Criteria
pollutants (and now Air Toxics) to which the area
population may be exposed. The primary emission
source is motor vehicles, with many commercial
businesses also in the area.
This air monitoring site is located in south central
Pinellas County at Skyview Elementary School, 8601
60th St. N., Pinellas Park, Florida. This site is a
NATTS and samples for all pollutants/parameters
required by NATTS, including VOCs, carbonyls,
metals, PM2 5 speciation, and black carbon. In
addition, measurements are made for wind speed,
wind direction, ambient pressure, and ambient
temperature. Site spatial scale is neighborhood. This
is a population-oriented site.
VO
to
BOLD = EPA-designated NATTS Site
-------
Table 9-1. Geographical Information for the Florida Monitoring Sites (Continued)
Site
Code
SYFL
AQS Code
12-057-3002
Location
Plant City
County
Hills-
borough
Micro- or
Metropolitan
Statistical Area
Tampa-St.
Petersburg-
Clearwater, FL
Latitude
and
Longitude
27.96565,
-82.2304
Land Use
Residential
Location
Setting
Rural
Description of the
Immediate Surroundings
The site in Sydney is a NATTS neighborhood/rural
site. Monitoring has been occurring at Sydney for 5
years as a background site. Current development in
the area warranted it becoming a NATTS site. The
Sydney site is also being used for an intercomparison
of the port of Tampa as compared to a neighbor/rural
site.
BOLD = EPA-designated NATTS Site
-------
SYFL is located in Plant City, which is also part of the Tampa-St. Petersburg-Clearwater,
FL MSA, although it is on the eastern outskirts of the area. Unlike the other program, the SYFL
monitoring site is in a rural area although, as Figure 9-4 shows, a residential community lies to
the west of the site. This site serves as a background site, although the impact of increased
development in the area is likely being captured by the monitor.
Figure 9-7 shows the location of Tampa/St. Petersburg sites in relation to each other.
SYFL is located the furthest east and AZFL is the furthest west. The majority of the point
sources are located just north of SKFL. Another cluster of emission sources is located about
halfway between SYFL and GAFL. There are also several emission sources just east of GAFL.
Surface coating and processes involving fuel combustion are the most numerous source
categories in the Tampa/St. Petersburg area (based on the areas covered by the 10-mile radii).
ORFL is located in Winter Park, north of Orlando. Figure 9-5 shows that ORFL is
located near Lake Mendsen, east of Lake Killarney and south of Winter Park Village. This site
lies in a commercial area and serves as a population exposure monitor. Several emission sources
surround ORFL, as shown in Figure 9-8, most of which are involved in waste treatment and
disposal or processes utilizing fuel combustion.
FLFL is located on Florida's east coast in Davie, near Ft. Lauderdale. The site is located
at the Agricultural Research Center on the University of Florida campus. Figure 9-6 shows that
the surrounding area is suburban and commercial. The site is less than a mile south of 1-595 and
other major highways are also within a few miles. Nearby point sources are located mostly to
the northeast and east of the monitoring site, as shown in Figure 9-9. A majority of the point
sources are involved in liquids distribution or surface coating.
Table 9-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Florida
monitoring sites. County-level vehicle registration and population data for Pinellas, Broward,
Hillsborough, and Orange Counties were obtained from the Florida Department of Highway
9-14
-------
Table 9-2. Population, Motor Vehicle, and Traffic Information for the Florida Monitoring
Sites
Site
AZFL
FLFL
GAFL
ORFL
SKFL
SYFL
2007
Estimated
County
Population
917,437
1,759,591
1,174,727
1,066,113
917,437
1,174,727
Number
of
Vehicles
Registered
1,548,528
1,541,754
1,203,440
1,048,589
1,548,528
1,203,440
Vehicles
per Person
(Registration:
Population)
1.69
0.88
1.02
0.98
1.69
1.02
Population
Within
10 Miles
567,158
1,327,088
475,725
1,008,282
690,988
281,664
Estimated
10 mile Vehicle
Ownership
957,297
1,162,795
487,353
991,709
1,166,308
288,549
Annual
Average
Traffic
Data1
37,000
14,000
41,000
35,500
48,000
30,500
VMT
(thousands)
63,178
132,934
63,178
42,448
63,178
63,178
BOLD = EPA-designated NATTS Site
Safety and Motor Vehicles and the U.S. Census Bureau. Table 9-2 also includes a vehicle
registration to county population ratio (vehicles per person). In addition, the population within
10 miles of each site is presented. An estimate of 10-mile vehicle registration was calculated by
applying the county-level vehicle registration to population ratio to the 10-mile population
surrounding the monitoring site. Table 9-2 also contains annual average daily traffic
information, as well as the year of the traffic data estimate and the source from which it was
obtained. Finally, Table 9-2 presents the daily VMT for each urban area.
Observations from Table 9-2 include the following:
• Broward County, where FLFL is located, is the most populous of the Florida counties
with monitoring sites, although Hillsborough and Orange Counties both have over a
million people. Broward County is the eighth most populous county of all the
NATTS and UATMP counties covered in this report.
• The FLFL and ORFL monitoring sites have the highest population within 10 miles of
all the Florida sites.
• Vehicle registration counts for the Florida sites are all over one million, with Pinellas
County having the most. The 10-mile ownership estimates are more variable.
• The vehicles per person ratios ranged from 0.88 (FLFL) to 1.69 (AZFL and SKFL).
• VMT was highest for the Miami/Ft. Lauderdale urban area and lowest for the Orlando
urban area. The Miami/Ft. Lauderdale VMT ranked fourth highest among urban
areas with NATTS and UATMP monitoring sites.
9-15
-------
• Traffic volumes near the Florida monitoring sites were mid-range among NATTS and
UATMP monitoring sites. The following list provides the roadways or intersections
from which the traffic data was obtained:
• AZFL - Tyrone Boulevard, west of 66th Street North
• FLFL - College Avenue, south of Nova Drive
• GAFL - Gandy Boulevard, east of Westshore Boulevard
• ORFL - intersection of Lee Road and Orlando Avenue
• SKFL - Park Boulevard, east of 66th Street North
• S YFL - East of Dover Road
9.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Florida on sampling days, as well as over the course of the year.
9.2.1 Climate Summary
Florida=s climate is subtropical, with very mild winters and warm, humid summers. The
annual average maximum temperature is around 80EF for all locations and average relative
humidity is near 70 percent. Although land and sea breezes affect each of the locations, wind
generally blows from an easterly direction due to high pressure offshore (Ruffner and Bair,
1987).
9.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The weather
station closest to the AZFL monitoring site is located at St. Petersburg/Whitted Airport (WBAN
92806); closest to GAFL is at Tampa International Airport (WBAN 12842); closest to SKFL is
at St. Petersburg/Clearwater International Airport (WBAN 12873); closest to SYFL is at Winter
Haven=s Gilbert Airport (WBAN 12876); closest to ORFL is at Orlando Executive Airport
(WBAN 12841); and closest to FLFL is at Ft. Lauderdale/Hollywood International Airport
(WBAN 12849).
9-16
-------
Table 9-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 9-3 is the 95 percent
confidence interval for each parameter. As shown in Table 9-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year, with the exception of FLFL. Temperatures and humidity appear much lower during
sample days for this site. FLFL stopped sampling in March 2007, thereby capturing only the
coolest months of the year.
9.2.3 Composite Back Trajectories for Sampling Days
Figures 9-10 through 9-15 are composite back trajectory maps for the Florida monitoring
sites for the days on which samples were collected. Each line represents the 24-hour trajectory
along which a parcel of air traveled toward the monitoring site on a sampling day. Each
concentric circle around the sites in Figures 9-10 through 9-15 represents 100 miles.
Observations from Figures 9-10 through 9-13 for the Tampa/St. Petersburg sites include
the following:
• The composite back trajectory maps for the Tampa/St. Petersburg sites are very
similar to each other.
• Back trajectories originated from a variety of directions at the Tampa/St. Petersburg
sites. However, the bulk of the trajectories originated from the east.
• The 24-hour air shed domain was comparable in size to other monitoring sites. The
furthest away a trajectory originated was over the Atlantic Ocean, or just over 600
miles away.
• Most trajectories originated within 400 miles of the Tampa/St. Petersburg monitoring
sites.
Observations from Figure 9-14 for ORFL include the following:
• The composite back trajectory map for ORFL is fairly similar to the Tampa/St.
Petersburg sites.
9-17
-------
Table 9-3. Average Meteorological Conditions near the Florida Monitoring Sites
Site
AZFL
FLFL
GAFL
ORFL
SKFL
SYFL
Closest NWS
Station and
WBAN
St. Petersburg/
Whitted
Airport
92806
Ft Lauderdale/
Hollywood Intl
Airport
12849
Tampa/
International
12842
Orlando
Executive
Airport
12841
St Petersburg-
Clearwater Intl
Airport
12873
Winter
Haven's
Gilbert Airport
12876
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
81.07
±2.30
80.75
±0.88
75.82
±2.90
83.70
±0.58
83.02
±2.19
82.29
±0.88
82.62
±2.46
82.47
±0.92
82.79
±2.21
82.36
±0.87
83.95
±2.39
82.88
±0.95
Average
Temperature
(op)
71.43
±2.23
74.12
±0.88
69.56
±4.05
77.98
±0.63
74.38
±2.24
73.78
±0.92
73.44
±2.36
73.18
±0.89
74.78
±2.19
74.29
±0.88
73.38
±2.26
72.58
±0.91
Average
Dew Point
Temperature
(°F)
63.84
±2.57
63.61
±1.00
54.61
±5.56
64.63
±0.83
62.17
±2.83
61.85
±1.13
60.90
±2.80
60.59
±1.12
63.87
±2.80
63.54
±1.11
62.17
±2.58
61.72
±1.09
Average
Wet Bulb
Temperature
(»F)
67.81
±2.19
67.59
±0.86
61.08
±4.26
69.51
±0.66
66.93
±2.30
66.52
±0.92
65.83
±2.31
65.62
±0.90
68.06
±2.28
67.69
±0.91
66.49
±2.19
65.98
±0.91
Average
Relative
Humidity
(%)
70.92
±2.16
71.15
±0.93
60.81
±6.16
64.82
±0.81
67.91
±2.41
68.50
± 1.03
67.24
±2.27
67.18
± 1.01
70.67
±2.49
71.03
±1.05
70.93
±2.04
71.63
±0.94
Average
Sea Level
Pressure
(mb)
1017.28
±1.10
1017.01
±0.41
1020.52
±2.20
1016.52
±0.37
1017.92
± 1.03
1017.52
±0.41
1018.56
±1.15
1018.30
±0.43
1017.61
± 1.10
1017.48
±0.41
1018.08
±1.06
1017.85
±0.41
Average
Scalar Wind
Speed
(kt)
7.48
±0.72
7.86
±0.31
9.11
±1.93
8.53
±0.33
5.55
±0.39
5.74
±0.20
5.76
±0.50
6.17
±0.25
6.84
±0.64
6.92
±0.27
6.23
±0.52
6.43
±0.25
VO
oo
BOLD = EPA-designated NATTS Site
-------
Figure 9-10. Composite Back Trajectory Map for AZFL
-------
Figure 9-11. Composite Back Trajectory Map for GAFL
to
o
-------
Figure 9-12. Composite Back Trajectory Map for SKFL
to
-------
Figure 9-13. Composite Back Trajectory Map for SYFL
to
to
-------
Figure 9-14. Composite Back Trajectory Map for ORFL
to
-------
Figure 9-15. Composite Back Trajectory Map for FLFL
to
-------
Back trajectories originated from a variety of directions at ORFL. However, the bulk
of the trajectories originate from the east.
The 24-hour air shed domain was comparable in size to the other Florida monitoring
sites. The furthest away a trajectory originated was north-central Tennessee, or
nearly 600 miles away.
Similar to the Tampa/St. Petersburg sites, most trajectories originated with 400 miles
of ORFL.
Observations from Figure 9-15 for FLFL include the following:
• Sampling was conducted at FLFL for the first quarter of the calendar year only. As a
result, fewer trajectories are shown in Figure 9-15.
• Back trajectories primarily originated from the east and north-northeast.
• The 24-hour air shed domain appears slightly smaller for FLFL than for the other
Florida monitoring sites. The furthest away a trajectory originated was over the
Atlantic, or less than 600 miles away.
9.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations near the Florida sites, as presented in Section
9.2.2, were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce
customized wind roses. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figures 9-16 through 9-21 are the
wind roses for the Florida monitoring sites on days that samples were collected.
Observations from Figure 9-16 for AZFL include the following:
• Easterly, northeasterly, and northerly winds were prevalent near AZFL.
• Calm winds were observed infrequently near AZFL (less than eight percent).
• Winds exceeding 11 knots made up less than 17 percent of observations. Stronger
wind speeds were observed with easterly and northeasterly winds.
Observations from Figure 9-17 for FLFL include the following:
• Easterly winds prevailed near FLFL (nearly 27 percent of observations).
9-25
-------
Figure 9-16. Wind Rose for AZFL Sampling Days
NORTH"---.
WEST I
1 5%
WIND SPEED
(Knots)
n -22
• 17 - 21
^| 11 • 17
^| 7- 11
2- 4
Calms: 7.93%
Figure 9-17. Wind Rose for FLFL Sampling Days
•WEST:
9-26
-------
Figure 9-18. Wind Rose for GAFL Sampling Days
5%
Figure 9-19. Wind Rose for ORFL Sampling Days
15%
"- 1 '
.-'' / / WIND
(Knot
,--'"'" -''' ^
SOUTH--""'' ' '
--..u. —
n
Calms
SPEED
0
>=22
17-21
11 - 17
7- 11
•q- 7
2- 4
14.40%
9-27
-------
Figure 9-20. Wind Rose for SKFL Sampling Days
WEST
SOUTH ,-'
EAST
WIND SPEED
(Knots)
CH = 22
• 17 - 21
• 11 - 17
EH 1-7
^| 2- 4
Calms: 7.35%
Figure 9-21. Wind Rose for SYFL Sampling Days
NORTH*---.
•WEST:
20%
9-28
-------
• Calm winds were observed very infrequently near FLFL (less than three percent).
• Winds exceeding 11 knots madeup nearly 28 percent of observations. Stronger wind
speeds were observed with easterly and northeasterly winds.
• The observations contained in the wind rose for FLFL include the first quarter of the
year only. A wind rose with a full year's worth of observations may look differently.
Observations from Figure 9-18 for GAFL include the following:
• Northeasterly and east-northeasterly winds prevailed near GAFL.
• Calm winds were observed for less than 13 percent of the measurements.
• Winds exceeding 11 knots were less frequently observed, with less than three percent
of observations.
Observations from Figure 9-19 for ORFL include the following:
• Easterly, northeasterly, and northerly winds were prevalent near ORFL.
• Calm winds were observed for less than 15 percent of the measurements.
• Winds exceeding 11 knots were observed for just over eight percent of observations.
Stronger wind speeds were observed most frequently with easterly and northeasterly
winds.
Observations from Figure 9-20 for SKFL include the following:
• Easterly and northeasterly winds were prevalent near SKFL.
• Calm winds were observed for less than eight percent of the measurements.
• Winds exceeding 11 knots were observed for less than eight percent of observations.
The strongest wind speeds were observed with southerly and southwesterly winds.
Observations from Figure 9-21 for SYFL include the following:
• Easterly winds were prevalent near SYFL.
• Calm winds were observed for nine percent of the measurements.
• Winds exceeding 11 knots were observed for less than eight percent of observations.
9-29
-------
9.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Florida
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 9-4 presents the pollutants that failed at least one screen for the Florida monitoring sites
and highlights each site's pollutants of interest (shaded). All of the Florida sites sampled for
carbonyl compounds. Additionally, SYFL sampled hexavalent chromium.
Observations from Table 9-4 include the following:
• Acetaldehyde and formaldehyde are the only two carbonyls with screening values.
• Acetaldehyde and formaldehyde failed at least one screen for all six Florida
monitoring sites. Most, if not all, of the measured detections of these pollutants failed
screens.
• Acetaldehyde and formaldehyde contributed equally to the number of failed screens
for AZFL and ORFL, while acetaldehyde contributed more to the number of failed
screens for the remaining sites.
• Hexavalent chromium did not fail any screens for SYFL.
Table 9-4. Comparison of Measured Concentrations and EPA Screening Values for the
Florida Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
St. Petersburg, Florida - AZFL
Acetaldehyde
Formaldehyde
Total
60
60
120
60
60
120
100.00
100.00
100.00
50.00
50.00
50.00
100.00
9-30
-------
Table 9-4. Comparison of Measured Concentrations and EPA Screening Values for
Florida Monitoring Sites (Continued)
the
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Davie, Florida - FLFL
Acetaldehyde
Formaldehyde
Total
10
6
16
10
10
20
100.00
60.00
80.00
62.50
37.50
62.50
100.00
Tampa, Florida - GAFL
Acetaldehyde
Formaldehyde
Total
59
56
115
60
60
120
98.33
93.33
95.83
51.30
48.70
51.30
100.00
Winter Park, Florida - ORFL
Formaldehyde
Acetaldehyde
Total
58
58
116
58
58
116
100.00
100.00
100.00
50.00
50.00
50.00
100.00
Pinellas Park, Florida - SKFL
Acetaldehyde
Formaldehyde
Total
60
42
102
60
60
120
100.00
70.00
85.00
58.82
41.18
58.82
100.00
Plant City, Florida - SYFL
Acetaldehyde
Formaldehyde
Total
60
56
116
60
60
120
100.00
93.33
96.67
51.72
48.28
51.72
100.00
9.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Florida monitoring sites. The averages presented are provided for the pollutants of interest
for each site. Complete site-specific statistical summaries are provided in Appendices J through
O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
9.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
9-31
-------
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 9-5, where applicable.
Table 9-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Florida Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Hg/m3)
Winter
Average
(Hg/m3)
Spring
Average
(Hg/m3)
Summer
Average
(Hg/m3)
Autumn
Average
(Hg/m3)
Annual
Average1
(Hg/m3)
St. Petersburg, Florida - AZFL
Acetaldehyde
Formaldehyde
60
60
60
60
1.42
±0.19
2.95
±0.20
2.23
±0.53
2.28
±0.34
1.36
±0.20
3.35
±0.36
1.03
±0.15
3.26
±0.42
1.12
±0.15
2.82
±0.23
1.42
±0.19
2.95
±0.20
Davie, Florida - FLFL
Acetaldehyde
Formaldehyde
10
10
10
10
2.47
±0.50
1.14
±0.19
2.74
±0.56
1.15
±0.27
NA
NA
NA
NA
NA
NA
NA
NA
Tampa, Florida - GAFL
Acetaldehyde
Formaldehyde
60
60
60
60
2.54
±0.23
2.45
±0.54
3.18
±0.29
3.45
±2.45
2.68
±0.57
2.12
±0.42
2.26
±0.28
2.44
±0.26
2.19
±0.42
2.03
±0.40
2.54
±0.23
2.45
±0.54
Winter Park, Florida - ORFL
Acetaldehyde
Formaldehyde
58
58
58
58
1.62
±0.29
2.59
±0.53
2.47
±0.59
1.67
±0.26
1.16
±0.28
2.28
±0.53
1.25
±0.19
3.37
±0.49
1.55
±0.80
3.12
±1.90
1.62
±0.29
2.59
±0.53
Pinellas Park, Florida - SKFL
Acetaldehyde
Formaldehyde
60
60
60
60
1.98
±0.22
1.66
±0.24
2.53
±0.42
1.59
±0.20
1.38
±0.22
2.50
±0.40
1.86
±0.55
1.56
±0.58
2.29
±0.26
0.88
±0.11
1.98
±0.22
1.66
±0.24
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
9-32
-------
Table 9-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Florida Monitoring Sites (Continued)
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(Hg/m3)
Annual
Average1
(jig/m3)
Plant City, Florida - SYFL
Acetaldehyde
Formaldehyde
60
60
60
60
2.73
±0.52
3.18
±0.93
3.60
±1.98
5.39
±2.80
3.38
±0.49
1.93
±0.37
2.13
±0.19
2.38
±0.58
1.91
±0.27
3.24
±2.16
2.73
±0.52
3.18
±0.93
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations about acetaldehyde from Table 9-5 include the following:
• The sites with the highest daily average concentration of acetaldehyde were SYFL
(2.73 ± 0.52 |ig/m3), GAFL (2.54 ± 0.23 |ig/m3), and FLFL (2.47 ± 0.50 |ig/m3).
• The winter average concentrations of acetaldehyde tended to be higher than other
seasons. However, the confidence intervals suggest that only the winter average for
AZFL is significantly higher than other seasons.
• The large confidence interval for SYFL indicates that the winter average was
influenced by outliers.
• As shown in Table 4-9, SYFL and GAFL had the eighth and tenth highest daily
average concentrations of acetaldehyde among all NATTS and UATMP sites.
Observations about formaldehyde from Table 9-5 include the following:
• The sites with the highest daily average concentration of formaldehyde were SYFL
(3.18 ± 0.93 |ig/m3), AZFL (2.95 ± 0.20 |ig/m3), and ORFL (2.59 ± 0.53 |ig/m3).
• The large confidence intervals for the winter averages for GAFL and SYFL indicate
that these averages were influenced by outliers. The same can be said for the autumn
averages for SYFL and ORFL.
• The Florida sites did not have any of the 10 highest daily averages of formaldehyde,
according to Table 4-9.
9-33
-------
9.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. AZFL, GAFL, and ORFL have sampled as part of the UATMP or
NATTS for at least five years. Figures 9-22 through 9-24 present the three-year rolling statistical
metrics graphically for formaldehyde for each of these sites. The statistical metrics presented for
calculating trends include the substitution of zeros for non-detects.
Observations from Figure 9-22 for formaldehyde measurements at AZFL include the
following:
• Sampling for carbonyl compounds under the UATMP at AZFL began in 2001.
• The maximum formaldehyde concentration shown was measured during the 2001-
2003 time frame. The maximum concentrations measured in subsequent time periods
were less than half the maximum concentration from the 2001-2003 time frame.
• The rolling average concentrations have a decreasing trend from 2001-2003 through
the 2003-2005 time periods. Although an increase is observed for the 2004-2006
through 2005-2007 periods, the range of values measured from the 2002-2004 time
period forward changed little over time.
• The central tendency of the rolling averages and the median values were observed to
be similar for each time period. The "closeness" in these metrics indicates little
variability in the central tendency.
• All formaldehyde concentrations reported to AQS over the seven years of sampling
were measured detections.
Observations from Figure 9-23 for formaldehyde measurements at GAFL include the
following:
• Sampling for carbonyl compounds under the UATMP at GAFL began in 2001.
• The maximum formaldehyde concentration shown was measured during 2005. The
average concentration is greater than the third quartile for the last three time frames,
indicating the presence of outliers.
9-34
-------
Figure 9-22. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at AZFL
14.00
12.00 -
10.00 -
J; s.oo
=
_o
6.00 -
4.00 -
2.00 -
0.00
o
U
O
mmm
2001-2003
2002-2004
2003-2005
Three-Year Period
2004-2006
2005-2007
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 9-23. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at GAFL
120.00
100.00
.o
o.
a
=
I 60.00
I
o
U
40.00
20.00
0.00
2001-2003
2002-2004
2003-2005
Three-Year Period
2004-2006
2005-2007
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 9-24. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at ORFL
14.00 -i
12.00
10.00
3.00
on
=
| 6.00
o
U
4.00
0.00
2003-2005
2004-2006
Three- Year Period
2005-2007
1st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
• The first and third quartiles are very similar for each time period, as are the median
and rolling average concentrations. The "closeness" in these metrics indicates little
variability in the central tendency.
• All formaldehyde concentrations reported to AQS over the seven years of sampling
were measured detections.
Observations from Figure 9-24 for formaldehyde measurements at ORFL include the
following:
• Sampling for carbonyl compounds under the UATMP at ORFL began in 2003.
• The rolling average concentrations appeared to have decreased slightly over the
period shown, although the maximum formaldehyde concentration shown was
measured during the 2005-2007 time frame. However, the calculation of confidence
intervals indicates the decrease is not statistically significant.
• The central tendency of the rolling averages and the median values were observed to
be similar for each time period. This indicates little variability in the central
tendency.
• Similar to AZFL and GAFL, all formaldehyde concentrations reported to AQS over
the five years of sampling were measured detections.
9.5 Pearson Correlations
Table 9-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for acetaldehyde from Table 9-6 include the following:
• AZFL exhibited strong negative correlations with the temperature and moisture
variables. With the exception of FLFL and SKFL, all of the correlations with these
variables were negative. This indicates that as temperature and moisture content
decrease, concentrations of acetaldehyde increase.
• All of the sites exhibited negative correlations with wind speed, indicating that
concentrations of acetaldehyde increase as wind speeds decrease.
• The FLFL monitoring site exhibited the strongest negative correlation with wind
speed. However, the low number of measurements may skew this correlation.
9-38
-------
Table 9-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Florida
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
St. Petersburg, Florida - AZFL
Acetaldehyde
Formaldehyde
60
60
-0.61
0.58
-0.65
0.49
-0.70
0.35
-0.69
0.39
-0.40
-0.17
0.47
-0.11
-0.15
0.05
Davie, Florida - FLFL
Acetaldehyde
Formaldehyde
10
10
0.03
0.13
-0.20
-0.07
-0.20
-0.01
-0.21
-0.04
-0.12
0.08
0.03
-0.49
-0.69
-0.53
Tampa, Florida - GAFL
Acetaldehyde
Formaldehyde
60
60
-0.28
0.02
-0.32
0.07
-0.29
0.10
-0.31
0.09
-0.16
0.15
0.33
0.15
-0.38
-0.16
Winter Park, Florida - ORFL
Acetaldehyde
Formaldehyde
58
58
-0.45
0.36
-0.46
0.35
-0.52
0.27
-0.50
0.30
-0.39
-0.02
0.13
-0.35
-0.04
-0.04
Pinellas Park, Florida - SKFL
Acetaldehyde
Formaldehyde
60
60
-0.12
-0.01
-0.13
-0.09
-0.06
-0.22
-0.09
-0.18
0.11
-0.35
0.11
0.10
-0.46
0.01
Plant City, Florida - SYFL
Acetaldehyde
Formaldehyde
60
60
-0.41
-0.38
-0.39
-0.34
-0.35
-0.24
-0.37
-0.29
-0.02
0.14
0.31
0.21
-0.03
-0.31
VO
OJ
VO
-------
Observations for formaldehyde from Table 9-6 include the following:
• AZFL exhibited strong positive correlations with the temperature variables. This
tendency was not observed for the other Florida sites.
• The FLFL site exhibited the strongest negative correlation with wind speed.
However, the low number of measurements may skew this correlation.
• The remaining correlations were weak.
9.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
9.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Florida
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. None of the pollutants
measured at the Florida sites exceeded any of the MRL risk values.
9.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Florida sites and where the annual
average concentrations could be calculated, risk was further examined by reviewing cancer and
noncancer risk estimates from NATA and calculating cancer and noncancer surrogate risk
approximations (refer to Section 3.6.5 of this report regarding the criteria for an annual average
and how cancer and noncancer surrogate risk approximations are calculated). Concentration and
risk estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer
and noncancer surrogate risk approximations are presented in Table 9-7. The data from NATA
9-40
-------
Table 9-7. Cancer and Noncancer Risk Summary for the Monitoring Sites in Florida
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
St. Petersburg, Florida (AZFL) - Census Tract ID 12103022402
Acetaldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.20
1.31
2.66
0.01
0.13
0.13
1.42 ±0.19
2.95 ±0.20
2.85
0.02
0.16
0.30
Davie, Florida (FLFL) - Census Tract ID 12011070204
Acetaldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.66
2.30
3.70
0.01
0.18
0.23
NA
NA
NA
NA
NA
NA
Tampa, Florida (GAFL) - Census Tract ID 12057006500
Acetaldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.71
1.72
3.80
0.01
0.19
0.17
2.54 ±0.23
2.45 ±0.54
5.07
0.01
0.28
0.25
Winter Park, Florida (ORFL) - Census Tract ID 12095015901
Acetaldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.98
1.99
4.37
0.01
0.22
0.2
1.62 ±0.29
2.59 ±0.53
3.23
0.01
0.18
0.26
Pinellas Park, Florida (SKFL) - Census Tract ID 12103024905
Acetaldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.64
1.73
3.62
0.01
0.18
0.17
1.98 ±0.22
1.66 ±0.24
3.96
0.01
0.22
0.17
Plant City, Florida (SYFL) - Census Tract ID 12057012204
Acetaldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.24
1.42
2.74
0.01
0.13
0.14
2.73 ±0.52
3. 18 ±0.93
5.46
0.02
0.30
0.32
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
-------
are presented for the census tract where each monitoring site is located. The pollutants of
interest for each site are bolded.
The census tract information for the Florida sites is as follows, grouped by county:
• 12103022402 for AZFL and!2103024905 for SKFL; the 5,456 people residing in the
AZFL census tract represented 0.6 percent of the 2000 Pinellas County population,
while the 6,522 residents of the SKFL census tract represented 0.7 percent of the
2000 Pinellas County population.
• 12011070204 for FLFL; the 4,301 residents of the FLFL census tract represented 0.3
percent of the 2000 Broward County population.
• 12057006500 for GAFL, 12057012204 for SYFL; the 5,913 people residing in the
GAFL census tract represented 0.6 percent of the 2000 Hillsborough County
population; the 4,362 residents of the SYFL census tract represented 0.4 percent of
the 2000 Hillsborough County population.
• 12095015901 for ORFL; the 2,083 people residing in the ORFL census tract
represented 0.2 percent of the 2000 Orange County population.
Observations for the Florida sites from Table 9-7 include the following:
• The NATA modeled concentrations of acetaldehyde and formaldehyde were fairly
similar to the annual averages.
• The cancer risk for acetaldehyde from NATA ranged from 2.66 in-a-million (AZFL)
to 4.37 in-a-million (ORFL). Cancer risk from formaldehyde was 0.01 in-a-million
for all six Florida sites, according to NATA.
• The cancer surrogate risk approximations from acetaldehyde ranged from 2.85 in-a-
million (AZFL) to 5.46 in-a-million (SYFL). The surrogate cancer risk
approximations for formaldehyde were 0.02 in-a-million or less for all six Florida
sites, according to NATA.
• Both the noncancer risk from NATA and the noncancer surrogate risk approximations
were less than 1.0 (HQ) for all of the Florida sites for formaldehyde and
acetaldehyde.
• Annual averages were not calculated for FLFL; therefore, this site has no surrogate
risk approximations in Table 9-7.
9-42
-------
9.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 9-8 and 9-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 9-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
surrogate cancer risk approximations (in-a-million), as calculated from the annual averages.
Table 9-9 presents similar information, but identifies the 10 pollutants with the highest surrogate
noncancer risk approximations (HQ), as calculated from the annual averages. The pollutants in
these tables are limited to those that have cancer and noncancer risk factors, respectively. As a
result, although the actual value of the emissions are the same, the highest emitted pollutants in
the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 9.3, each Florida site sampled
for carbonyl compounds. SYFL also sampled hexavalent chromium. In addition, the cancer and
noncancer surrogate risk approximations are limited to those sites sampling for a long enough
period for annual averages to be calculated; therefore, cancer and noncancer risk approximations
are not presented for FLFL.
Observations from Table 9-8 include the following:
• Benzene was the highest emitted pollutant with a cancer URE in all four Florida
counties (Pinellas, Hillsborough, Orange, and Broward).
• With the exception of Broward County, benzene was also had the highest toxicity-
weighted emissions. Benzene ranked 2nd behind naphthalene for Broward County.
• For Pinellas County, six of the highest emitted pollutants also had the highest
toxicity-weighted emissions; seven for Hillsborough County; six for Orange County;
and seven for Broward County. Four pollutants, acetaldehyde, benzene, naphthalene,
and 1,3-butadiene appeared on both lists for each county.
• Acetaldehyde, which appeared on both lists for each county, topped the cancer risk
approximations for each site. Formaldehyde, which was one of the highest emitted
pollutants in each county, had very low cancer risk approximations
9-43
-------
Table 9-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Florida
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
St. Petersburg, FL (AZFL) - Pinellas County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Naphthalene
Trichloroethylene
Nickel,PM
Tetrachloroethylene
POM, Group 2
867.42
294.04
105.52
97.04
64.63
22.10
20.61
14.49
10.28
2.56
Benzene
1,3 -Butadiene
Nickel, PM
Hexavalent Chromium
Arsenic, PM
Naphthalene
Acetaldehyde
POM, Group 2
Cadmium, PM
Ethylene oxide
6.77E-03
2.91E-03
2.32E-03
1.20E-03
8.50E-04
7.51E-04
2.32E-04
1.41E-04
9.21E-05
6.22E-05
Acetaldehyde 2.85
Formaldehyde 0.02
Pinellas Park, FL (SKFL) - Pinellas County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Naphthalene
Trichloroethylene
Nickel, PM
Tetrachloroethylene
POM, Group 2
867.42
294.04
105.52
97.04
64.63
22.10
20.61
14.49
10.28
2.56
Benzene
1,3 -Butadiene
Nickel, PM
Hexavalent Chromium
Arsenic, PM
Naphthalene
Acetaldehyde
POM, Group 2
Cadmium, PM
Ethylene oxide
6.77E-03
2.91E-03
2.32E-03
1.20E-03
8.50E-04
7.51E-04
2.32E-04
1.41E-04
9.21E-05
6.22E-05
Acetaldehyde 3.96
Formaldehyde 0.01
-------
Table 9-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Florida (Continued)
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Tampa, FL (GAFL) - Hillsborough County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
Dichloromethane
Trichloroethylene
POM, Group 2
Nickel, PM
2,067.73
913.70
350.13
233.70
58.96
52.68
32.73
21.10
7.76
2.98
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Acetaldehyde
Cadmium, PM
Arsenic, PM
Nickel, PM
POM, Group 2
Tetrachloroethylene
1.61E-02
7.01E-03
4.58E-03
1.79E-03
7.70E-04
7.28E-04
6.45E-04
4.76E-04
4.27E-04
3.48E-04
Acetaldehyde 5.07
Formaldehyde 0.01
Plant City, FL (SYFL) - Hillsborough County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
Dichloromethane
Trichloroethylene
POM, Group 2
Nickel, PM
2,067.73
913.70
350.13
233.70
58.96
52.68
32.73
21.10
7.76
2.98
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Acetaldehyde
Cadmium, PM
Arsenic, PM
Nickel, PM
POM, Group 2
Tetrachloroethylene
1.61E-02
7.01E-03
4.58E-03
1.79E-03
7.70E-04
7.28E-04
6.45E-04
4.76E-04
4.27E-04
3.48E-04
Acetaldehyde 5.46
Formaldehyde 0.02
-------
Table 9-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Florida (Continued)
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Winter Park, FL (ORFL) - Orange County
Benzene
Formaldehyde
Dichloromethane
Acetaldehyde
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
Trichloroethylene
POM, Group 2
POM, Group 1
1,098.33
387.81
157.30
138.94
122.49
61.86
27.07
24.14
4.27
0.86
Benzene
1,3 -Butadiene
Arsenic, PM
Hexavalent Chromium
Naphthalene
Tetrachloroethylene
Acetaldehyde
POM, Group 2
Nickel, PM
Ethylene oxide
8.57E-03
3.67E-03
2.27E-03
1.10E-03
9.20E-04
3.65E-04
3.06E-04
2.35E-04
1.04E-04
7.48E-05
Acetaldehyde 3.23
Formaldehyde 0.01
Davie, FL (FLFL) - Broward County
Benzene
Naphthalene
Dichloromethane
Formaldehyde
Acetaldehyde
1,3 -Butadiene
1 ,3 -Dichloropropene
Tetrachloroethylene
£>-Dichlorobenzene
Trichloroethylene
1,394.39
820.97
530.06
528.26
193.44
162.88
116.00
92.69
59.41
34.748
Naphthalene
Benzene
1,3 -Butadiene
Nickel, PM
Hexavalent Chromium
Arsenic, PM
/>-Dichlorobenzene
Tetrachloroethylene
1 ,3 -Dichloropropene
Acetaldehyde
2.79E-02
1.09E-02
4.89E-03
1.83E-03
1.01E-03
1.01E-03
6.54E-04
5.47E-04
4.64E-04
4.26E-04
-------
Table 9-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Florida
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
St. Petersburg, FL (AZFL) - Pinellas County
Toluene
Xylenes
Methanol
Benzene
Hexane
Hydrochloric acid
Ethylbenzene
Formaldehyde
Styrene
Methyl fer/-butyl ether
2,360.70
1,502.26
1,169.63
867.42
444.08
435.32
384.26
294.04
293.54
185.54
Acrolein
Nickel, PM
1,3 -Butadiene
Formaldehyde
Benzene
Manganese, PM
Hydrochloric acid
Xylenes
Acetaldehyde
Naphthalene
691,264.22
222,915.40
48,519.24
30,004.46
28,914.03
22,103.35
21,765.98
15,022.64
11,724.95
7,367.29
Formaldehyde 0.30
Acetaldehyde 0.16
Pinellas Park, FL (SKFL) - Pinellas County
Toluene
Xylenes
Methanol
Benzene
Hexane
Hydrochloric acid
Ethylbenzene
Formaldehyde
Styrene
Methyl fer/-butyl ether
2,360.70
1,502.26
1,169.63
867.42
444.08
435.32
384.26
294.04
293.54
185.54
Acrolein
Nickel, PM
1,3 -Butadiene
Formaldehyde
Benzene
Manganese, PM
Hydrochloric acid
Xylenes
Acetaldehyde
Naphthalene
691,264.22
222,915.40
48,519.24
30,004.46
28,914.03
22,103.35
21,765.98
15,022.64
11,724.95
7,367.29
Acetaldehyde 0.22
Formaldehyde 0.17
-------
Table 9-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Florida (Continued)
oo
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Tampa, FL (GAFL) - Hillsborough County
Toluene
Xylenes
Hydrochloric acid
Benzene
Methanol
Hexane
Formaldehyde
Ethylbenzene
Hydrofluoric acid
Methyl fer/-butyl ether
5,324.13
3,622.30
3,106.46
2,067.73
1,171.85
981.04
913.70
895.02
403.65
371.15
Acrolein
Hydrochloric acid
1,3 -Butadiene
Formaldehyde
Benzene
Nickel, PM
Manganese, PM
Acetaldehyde
Xylenes
Cadmium, PM
2,220,358.79
155,323.16
116,850.75
93,235.15
68,924.48
45,774.78
44,427.07
38,903.12
36,223.00
20,209.11
Acetaldehyde 0.28
Formaldehyde 0.25
Plant City, FL (SYFL) - Hillsborough County
Toluene
Xylenes
Hydrochloric acid
Benzene
Methanol
Hexane
Formaldehyde
Ethylbenzene
Hydrofluoric acid
Methyl fer/-butyl ether
5,324.13
3,622.30
3,106.46
2,067.73
1,171.85
981.04
913.70
895.02
403.65
371.15
Acrolein
Hydrochloric acid
1,3 -Butadiene
Formaldehyde
Benzene
Nickel, PM
Manganese, PM
Acetaldehyde
Xylenes
Cadmium, PM
2,220,358.79
155,323.16
116,850.75
93,235.15
68,924.48
45,774.78
44,427.07
38,903.12
36,223.00
20,209.11
Formaldehyde 0.32
Acetaldehyde 0.30
-------
Table 9-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Florida (Continued)
VO
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Winter Park, FL (ORFL) - Orange County
Toluene
Xylenes
Hydrochloric acid
Benzene
Methanol
Hexane
Ethylbenzene
Formaldehyde
Methyl isobutyl ketone
Styrene
2,962.97
2,022.98
1,434.26
1,098.33
979.18
533.36
485.48
387.81
340.49
245.46
Acrolein
Hydrochloric acid
1,3 -Butadiene
Formaldehyde
Benzene
Xylenes
Arsenic, PM
Acetaldehyde
Cyanide Compounds, gas
Nickel, PM
1,127,315.05
71,713.15
61,246.00
39,572.83
36,610.86
20,229.81
17,596.94
15,437.99
11,327.06
10,021.61
Formaldehyde 0.26
Acetaldehyde 0.18
Davie, FL (FLFL) - Broward County
Xylenes
Toluene
Ethylbenzene
Chloroform
Methanol
Benzene
Naphthalene
Hexane
Dichloromethane
Formaldehyde
56,145.14
31,910.88
13,721.63
9,751.73
7,845.07
1,394.39
820.97
666.85
530.06
528.26
Acrolein
Xylenes
Naphthalene
Nickel, PM
Chloroform
1,3 -Butadiene
Toluene
Formaldehyde
Benzene
Bromomethane
1,581,166.23
561,451.39
273,658.20
176,064.68
99,507.48
81,441.74
79,777.19
53,903.66
46,479.65
32,400.00
-------
Observations from Table 9-9 include the following:
• Toluene and xylenes were the highest emitted pollutants with noncancer RfCs in all
four Florida counties.
• Acrolein had the highest toxi city-weighted emissions of the pollutants with noncancer
RfCs.
• For Pinellas County, four of the highest emitted pollutants also had the highest
toxicity-weighted emissions; four for Hillsborough County; four for Orange County;
and five for Broward County. Three pollutants, benzene, xylenes, and formaldehyde
appeared on both lists for each county.
• Formaldehyde, which appeared on both lists for each county, had low noncancer risk
approximations for each site.
• Acetaldehyde, which was one of the highest emitted pollutants with a cancer URE in
each county, did not appear on the list of highest emitted pollutants with a noncancer
RfC. However, this pollutant did have one of the 10 highest toxicity-weighted
emissions for pollutants with noncancer RfCs. Acetaldehyde also had low noncancer
risk approximations for each site.
9.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Florida monitoring site were acetaldehyde
and formaldehyde.
*»* SYFL had the highest daily average concentrations of both acetaldehyde and
formaldehyde among the monitoring sites, even though this site was intended to serve
as a background site.
»«» None of the pollutants of interest for the Florida sites exceeded any of the MRL health
benchmarks.
9-50
-------
10.0 Site in Georgia
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Georgia, and integrates these concentrations with
emissions, meteorological, and risk information.
10.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Georgia site is located in
the Atlanta-Sandy Springs-Marietta, GAMS A. Figure 10-1 is a composite satellite image
retrieved from Google™ Maps showing the monitoring site in its urban location. Figure 10-2
identifies point source emission locations within 10 miles of the site as reported in the 2002 NEI
for point sources. Table 10-1 describes the area surrounding each monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
The SDGA monitoring is located in Decatur, Georgia, southeast of Atlanta. The site is
located on the DeKalb County Schools Environmental Education property off Wildcat Road.
Figure 10-1 shows that residential subdivisions, a greenhouse and horse barn, an athletic field,
and a high school surround the monitoring site. A golf course backs up against the school
property. 1-285 is located less than a mile north of the site. As Figure 10-2 shows, SDGA is
located near several point sources, most of which are located to the west of the site. These
emission sourcess are involved in a wide variety of industries, including waste treatment and
disposal, the manufacture of chemicals and allied products, and processes involving fuel
combustion.
Table 10-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Georgia
monitoring site. County-level vehicle registration and population data for DeKalb County were
obtained from the Georgia Department of Revenue and the U.S. Census Bureau. Table 10-2 also
10-1
-------
Figure 10-1. Decatur, Georgia (SDGA) Monitoring Site
o
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 10-2. NEI Point Sources Located Within 10 Miles of SDGA
-
: •
Met* Out to T«al«j dwiM j tixj «*xat>on m»
-------
Table 10-1. Geographical Information for the Georgia Monitoring Site
Site
Code
SDGA
AQS Code
13-089-0002
Location
Decatur
County
DeKalb
Micro- or
Metropolitan
Statistical Area
Atlanta-Sandy
Springs-Marietta,
GA
Latitude
and
Longitude
33.6875,
QA TQfmS
-OT-.-iJ/U-i / O
Land Use
Residential
Location
Setting
Suburban
Description of the
Immediate Surroundings
Northwesterly winds predominate making this site a
short-range downwind location from Atlanta's urban
core. Undeveloped land surrounds the site but within
1/8 of a mile there is a residential subdivision, a
greenhouse/horse barn, an athletic field, and a high
school. Traffic on Wildcat Road (a dead end, 2-lane
blacktop) has considerable vehicular and diesel traffic
during school hours. Three shelters comprise the dry
structures at the site. One houses the PAMS GC,
carbonyls and VOC equipment, another the
continuous monitors, and the third one belongs to
Georgia Tech. Paniculate matter, IMPROVE and
PM10 metals reside on exposed structures.
BOLD = EPA-designated NATTS Site
-------
Table 10-2. Population, Motor Vehicle, and Traffic Information for the Georgia
Monitoring Site
Site
SDGA
2007
Estimated
County
Population
737,093
Number
of
Vehicles
Registered
471,264
Vehicles
per Person
(Registration:
Population)
0.64
Population
Within
10 Miles
776,511
Estimated
10 mile Vehicle
Ownership
496,466
Annual
Average
Traffic
Data1
9,100
VMT
(thousands)
128,353
1 Daily Average Traffic Data reflects 2006 data from the Georgia DOT
BOLD = EPA-designated NATTS Site
includes a vehicle registration to county population ratio (vehicles per person). In addition, the
population within 10 miles of the site is presented. An estimate of 10-mile vehicle registration
was calculated by applying the county-level vehicle registration to population ratio to the
10-mile population surrounding the monitoring site. Table 10-2 also contains annual average
daily traffic information, as well as the year of the traffic data estimate and the source from
which it was obtained. Finally, Table 10-2 presents the daily VMT for each urban area.
Observations from Table 10-2 include the following:
• SDGA's county and 10-mile populations were in the middle of the range compared to
all counties with NATTS or UATMP sites. This is also true for its county-level and
10-mile vehicle ownership.
• The vehicle per person ratio was the sixth lowest compared to other NATTS or
UATMP sites.
• The traffic volume experienced near SDGA also ranked in the low to mid-range
compared to other monitoring sites. The traffic estimate used came from Clifton
Spring Road between Wildcat Road and Clifton Church Road.
• The Atlanta area VMT was the fifth highest among urban areas with UATMP or
NATTS sites.
10.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Georgia on sampling days, as well as over the course of the year.
10-5
-------
10.2.1 Climate Summary
Atlanta is the largest city in Georgia, and is located at the base of the Blue Ridge
Mountains. The Gulf of Mexico to the south is the major moisture source for weather systems
that move across the region. Both topographical features, in addition to the Atlantic Ocean to the
east, exert moderating influences on the area's climate (Ruffner and Bair, 1987).
10.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at W. B. Hartsfield/Atlanta International Airport (WBAN
13874).
Table 10-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 10-3 is the 95 percent
confidence interval for each parameter. As shown in Table 10-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
10.2.3 Composite Back Trajectories for Sampling Days
Figure 10-3 is the composite back trajectory map for the Georgia monitoring site for the
days on which samples were collected. Each line represents the 24-hour trajectory along which a
parcel of air traveled toward the monitoring site on a sampling day. Each concentric circle
around the site in Figure 10-3 represents 100 miles.
Observations from Figure 10-3 include the following:
• Back trajectories originated from a variety of directions at SDGA.
10-6
-------
Table 10-3. Average Meteorological Conditions near the Georgia Monitoring Site
Site
SDGA
Closest NWS
Station and
WBAN
W.B.
Hartsfield/ Atlanta
Intl Airport
13874
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
75.48
±3.62
73.60
± 1.54
Average
Temperature
(»F)
65.61
±3.61
64.04
±1.52
Average
Dew Point
Temperature
(°F)
49.30
±3.98
48.19
± 1.70
Average
Wet Bulb
Temperature
(°F)
56.77
±3.25
55.63
±1.39
Average
Relative
Humidity
(%)
59.30
±3.73
59.99
±1.52
Average
Sea Level
Pressure
(mb)
1018.65
±1.28
1018.58
±0.51
Average
Scalar Wind
Speed
(kt)
6.18
±0.60
6.82
±0.28
BOLD = EPA-designated NATTS Site
-------
Figure 10-3. Composite Back Trajectory Map for SDGA
o
oo
-------
• The 24-hour air shed domain for SDGA was fairly large in size compared to other
monitoring sites. The furthest away a trajectory originated was the Upper Peninsula
of Michigan, or nearly 900 miles away.
• The longest trajectories originated from westerly, northwesterly, and northerly
directions.
• However, most trajectories originated within 300 miles of the site.
10.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at Hartsfield International Airport near SDGA
were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce
customized wind roses. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figure 10-4 is the wind rose for
the Georgia monitoring site on days that samples were collected.
Figure 10-4. Wind Rose for SDGA Sampling Days
NORTH*---.
15%
SOUTH .-•
:AST
WIND SPEED
(Knots)
CH >=22
^| 17 - 21
^| 11 - 17
EH 4-7
• 2- 4
Calms: 12.35%
10-9
-------
Observations from Figure 10-4 for SDGA include the following:
• Easterly winds were the most frequently observed wind direction near SDGA (12
percent of observations), although southwesterly, westerly, and northwesterly winds
were also common.
• Calm winds were observed for over 12 percent of the hourly wind measurements.
• Winds exceeding 11 knots made up approximately 10 percent of observations.
10.3 Pollutants of Interest
"Pollutants of interest" were determined for the monitoring site in order to allow analysts
and readers to focus on a risk-based subset of pollutants. The pollutants of interest for the
Georgia monitoring site were identified using the EPA risk screening process described in
Section 3.2. In brief, each pollutant's measured concentration was compared to its associated
risk screening value. If the daily concentration was greater than the risk screening value, then
the measured concentration "failed the screen." Pollutants of interest are those for which the
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 10-4 presents the pollutants that failed at least one screen at the SDGA
monitoring site and highlights the pollutants of interest (shaded). SDGA sampled for SVOC and
hexavalent chromium.
Table 10-4. Comparison of Measured Concentrations and EPA Screening Values for the
Georgia Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Decatur, Georgia - SDGA
Naphthalene
Total
39
39
41
41
95.12
95.12
100.00
100.00
Observations from Table 10-4 include the following:
• Naphthalene was the only pollutant to fail at least one screen for SDGA, making it
SDGA's only pollutant of interest.
• Of the 41 measured detections of naphthalene, 39 failed screens, which translates into
a 95 percent failure rate.
10-10
-------
10.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Georgia monitoring site. The averages presented are provided for the pollutants of interest
for the monitoring site. Complete site-specific statistical summaries are provided in Appendices
J through O. In addition, concentration averages for select pollutants are presented from
previous sampling years in order to characterize concentration trends at the sites, where
applicable.
10.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 10-5, where applicable.
Table 10-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Georgia Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Ug/m3)
Winter
Average
(Ug/m3)
Spring
Average
(Ug/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Ug/m3)
Annual
Average
(Ug/m3)
Decatur, Georgia - SDGA
Naphthalene
41
41
0.08
±0.01
NA
NR
0.09
±0.02
0.09
±0.02
NA
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
NR = Not reportable due to the detection criteria for calculating a seasonal average
Observations for SDGA from Table 10-5 include the following:
• Because sampling of SVOC did not begin until the end of April, SDGA does not have
a winter, spring, or annual average for naphthalene.
• The summer and autumn averages of naphthalene were similar to the daily average.
10-11
-------
10.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. SDGA has not sampled continuously for five years as part of the
National Monitoring Program; therefore, the trends analysis was not conducted.
10.5 Pearson Correlations
Table 10-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for SDGA from Table 10-6 include the following:
• Naphthalene exhibited a strong negative correlation with scalar wind speed (-0.69).
This indicates that concentrations of naphthalene increase with decreasing wind
speed.
• The remaining correlations were relatively weak.
10.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
10.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Georgia
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. None of the pollutants
measured at the Georgia monitoring site exceeded any of the MRL risk values.
10-12
-------
Table 10-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Georgia
Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Decatur, Georgia - SDGA
Naphthalene
41
0.29
0.26
0.06
0.15
-0.32
-0.13
-0.69
-------
10.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Georgia monitoring site and where
the annual average concentrations could be calculated, risk was further examined by reviewing
cancer and noncaner risk estimates from NATA and calculating cancer and noncancer surrogate
risk approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
noncancer surrogate risk approximations are presented in Table 10-7. The data from NATA are
presented for the census tract where the monitoring site is located. The pollutants of interest for
the monitoring site are bolded.
Observations for SDGA from Table 10-7 include the following:
• The census tract for SDGA is 13089023404. The census tract had a population of
9,033, which represented less than two percent of DeKalb County's population in
2000.
• Naphthalene was the only pollutant to fail screens for the Georgia site.
• Annual averages (and therefore cancer and noncancer surrogate risk approximations)
could not be calculated for naphthalene due to the sampling duration criteria.
• The NATA modeled concentration of naphthalene is similar to the daily average of
naphthalene (which was presented in Table 10-5).
10.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 10-8 and 10-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 10-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer surrogate risk approximations (in-a-million), as calculated from the annual averages.
Table 10-9 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
10-14
-------
Table 10-7. Cancer and Noncancer Risk Summary for the Monitoring Site in Georgia
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Decatur, Georgia (SDGA) - Census Tract ID 13089023404
Naphthalene
0.000034
0.003
0.09
3.06
0.03
NA
NA
NA
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
-------
Table 10-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Georgia
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Decatur, Georgia (SDGA) - DeKalb County
Benzene
Formaldehyde
Dichloromethane
Acetaldehyde
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
Trichloroethylene
POM, Group 2
Bis(2-ethylhexyl)phthalate
716.38
227.52
118.49
81.97
69.56
52.60
16.89
11.94
3.68
1.57
Benzene
Arsenic, PM
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Tetrachloroethylene
POM, Group 2
Acetaldehyde
Cadmium, PM
Nickel, PM
5.59E-03
2.66E-03
2.09E-03
1.39E-03
5.74E-04
3.10E-04
2.02E-04
1.80E-04
1.18E-04
7.68E-05
-------
Table 10-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Georgia
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Decatur, Georgia (SDGA) - DeKalb County
Methyl isobutyl ketone
Toluene
Xylenes
Hydrochloric acid
Benzene
Glycol ethers, gas
Ethylene glycol
1,1,1 -Trichloroethane
Ethylbenzene
Methanol
3,454.02
2,787.11
2,301.23
1,629.75
716.38
686.52
360.80
357.79
305.95
273.76
Acrolein
Hydrochloric acid
1,3 -Butadiene
Glycol ethers, gas
Benzene
Formaldehyde
Xylenes
Arsenic, PM
Acetaldehyde
Cyanide Compounds, gas
711,105.67
81,487.50
34,782.15
34,325.85
23,879.28
23,216.21
23,012.26
20,589.96
9,107.72
8,416.67
-------
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual average are limited to those pollutants
for which each respective site sampled. As discussed in Section 10.3, SDGA sampled for SVOC
and hexavalent chromium. In addition, the cancer and noncancer surrogate risk approximations
are limited to those sites sampling for a long enough period for annual averages to be calculated.
Because SVOC sampling did not begin until late spring, cancer and noncancer surrogate risk
approximations were not calculated.
Observations from Table 10-8 include the following:
• Benzene, formaldehyde, and dichloromethane were the highest emitted pollutants
with cancer UREs in DeKalb County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) were benzene, arsenic, and 1,3-butadiene.
• Six of the highest emitted pollutants also have the highest toxi city-weighted
emissions for DeKalb County.
• Naphthalene, which was the only pollutant to fail screens at SDGA, has the fifth
highest toxicity-weighted emissions for DeKalb County.
• Hexavalent chromium, the only other pollutant sampled by SDGA to be included in
either list, has the fourth highest toxicity-weighted emissions for DeKalb County.
Observations from Table 10-9 include the following:
• Methyl isobutyl ketone, toluene, xylenes were the highest emitted pollutants with
noncancer RfCs in DeKalb County.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, hydrochloric acid, and 1,3-butadiene.
• Four of the highest emitted pollutants in DeKalb County also have the highest
toxicity-weighted emissions.
10-18
-------
• Naphthalene is not one of the highest emitted pollutants with a noncancer toxicity
factor, nor does it have one of the highest toxicity-weighted emissions.
10.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Naphthalene was the only pollutant to fail screens for SDGA.
»«» Naphthalene did not exceed any of the MRL health benchmarks.
10-19
-------
11.0 Sites in Illinois
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS and UATMP sites in Illinois, and integrates these
concentrations with emissions, meteorological, and risk information.
11.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. The Illinois sites are
located in the Chicago-Naperville-Joliet, IL-IN-WI MSA. Both sites are located in northwestern
suburbs of Greater Chicago. More specifically, NBIL is located in Northbrook and SPIL is
located in Schiller Park. Figures 11-1 and 11-2 are composite satellite images retrieved from
Google™ Maps showing the monitoring sites in their urban locations. Figure 11-3 identifies
point source emission locations within 10 miles of each site as reported in the 2002 NEI for point
sources. Table 11-1 describes the area surrounding each monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
NBIL is located on the property of the Northbrook Water Filtration Station. Figure 11-1
shows that NBIL is located on State Highway 68, Dundee Road, near exit 29 on 1-94. A railway
intersects Dundee Road close to the site. The surrounding area is classified as suburban and
residential. Commercial, residential, and forested areas are nearby.
SPIL is located on the eastern edge of the Chicago-O'Hare International Airport on
Mannheim Road. The nearest runway is less than a half mile away from the site. Figure 11-2
shows that SPIL is located near the Irving Park Road exit on 1-294. The surrounding area is
classified as suburban and mobile. Commercial and residential areas are nearby.
Figure 11-3 shows that NBIL and SPIL are located within 10 miles of each other. The
sites are also located within 10 miles of numerous point sources. The most numerous emission
sources are involved in surface coating and fuel combustion processes. Few point sources are
11-1
-------
Figure 11-1. Northbrook, Illinois (NBIL) Monitoring Site
PV^PHPMZI
.Expy.Spur.VV
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 11-2. Schiller Park, Illinois (SPIL) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 11-3. NEI Point Sources Located Within 10 Miles of NBIL and SPIL
Legend
~fr NEIL NATTS site "jf SPIlUATMPsile
Source Category Group (No. of Facilities)
A Agncultual S«w« Facility 1 5i
* Automotvw Repwr Services 4 Parking (It
Business Services Facility • l <
C Cherwcals 4 Allied Products Faeily 1 11 1
2 Electrical & Electronic EqufHnent Facility < 16t
0 Fabricated MM* Products Facility (21)
<3 Food 4 Kindred Products Factor/ (4|
Not*. DVM to t«ai«j dwiwij *o4 mVtKMon m* Services Faality ( 1 »
I Ktar*f anon industrial Faalily (3 1(
J kMtuslriai Madwery & Eqiipnwnt Fadllly (21)
- kntrumenls A Related FToducts F»c*t', 1 2 1
• hlsgrated Inn J $t»«l M*nur«clurlng FscHity <4i
L uqwtf* atnuten mawtnai Fwiny <2S>
LK Medcd Dental, £ Hospital Equipment and SuppJIes 0»
fl Wn«ral ProOuel* P»«essng IndgsTW F«*t/ r f Oi
X Mscellaneout MmufKUng Industries < 19)
O Personal Services 1 12>
P Petdemn,tJat Gas Prod £ Reflnng IndustHal FaoMy 12 1
> FnaintKeuticai Production Processes Industrial Fadliry &i
V Pttyners 4 Rssns Produdlon Industtal Factlily (2i
Q Fnmary Metal IndusJnes Facility ( Jj
R Printing 4 FubllSung Foolllyjfflf
4 Production at Organic ChemlcaJs hflustnal Facility M)
: : PU|I J Papef Pioducfccn Fec*ty 1 1 1
V Rubber & MisceSaneous PlastK Products Faallly 461
D sped*! Trade Ccntacten Facility 1. 1 \
U Stone. Qay. Gtass & Cavcrete Products 1 3 1
S salaw CMting process** HftdwUrlaJ F«ll«y
-------
Table 11-1. Geographical Information for the Illinois Monitoring Sites
Site
Code
NBIL
SPIL
AQS Code
17-031-4201
17-031-3103
Location
Northbrook
Schiller
Park
County
Cnnk
V^-LHJJ\.
County
Cook
County
]Micro- or
Metropolitan
Statistical Area
Chicago-
Naperville-Joliet,
IL-IN-WI MSA
Chicago-
Naperville-Joliet,
IL-IN-WI MSA
Latitude
and
Longitude
49 14
T-^. H",
-87.799167
41.965278,
-87.876389
Land Use
Residential
Mobile
Location
Setting
Suburban
Suburban
Description of the
Immediate Surroundings
The village of Northbrook is located in northeast Cook
County. This monitoring site is located at the
Northbrook Water Filtration Station at 750 Dundee
Road. A forest preserve is located immediately south
with residential areas farther south (southeast to
southwest). Residential areas are also immediately to
the west. Commercial areas are located along Dundee
Road and to the east. A major expressway (1-94) is
located 1 km to the east and north. O'Hare Airport is
located 18 km to the southwest and the Chicago Loop
is located 32 km to the southeast.
This monitoring site is located on a trailer at 4743
Mannheim Road just south of Lawrence Ave. and
between Mannheim Road and 1-294. The closest
runway at O'Hare Airport is 0.5 km to the northwest.
The immediate vicinity is mostly commercial.
Residential areas are located east across 1-294.
BOLD = EPA-designated NATTS Site
-------
located within two miles of NBIL, with most of the sources located further west or south. The
closest sources to NBIL are involved in processes using utility boilers or fuel combustion, or the
manufacture of industrial machinery and equipment. Numerous sources are located in close
proximity of SPIL. The closest sources to SPIL are involved in fuel combustion processes,
surface coating processes, automotive repair and services, and liquids distribution.
Table 11-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Illinois
monitoring sites. County-level vehicle registration and population data for Cook County, Illinois
were obtained from the Illinois Secretary of State and the U.S. Census Bureau. Table 11-2 also
includes a vehicle registration to county population ratio (vehicles per person). In addition, the
population within 10 miles of each site is presented. An estimate of 10-mile vehicle registration
was calculated by applying the county-level vehicle registration to population ratio to the
10-mile population surrounding the monitoring site. Table 11-2 also contains annual average
daily traffic information, as well as the year of the traffic data estimate and the source from
which it was obtained. Traffic data for NBIL is for Dundee Road near the railroad crossing;
traffic data for SPIL is from 1-294 and the intersection of Mannheim and Lawrence. Finally,
Table 11-2 presents the daily VMT for the urban area.
Table 11-2. Population, Motor Vehicle, and Traffic Information for the Illinois Monitoring
Sites
Site
NBIL
SPIL
2007
Estimated
County
Population
5,285,107
5,285,107
Number
of
Vehicles
Registered
2,104,894
2,104,894
Vehicles
per Person
(Registration:
Population)
0.40
0.40
Population
Within
10 Miles
870,561
2,049,963
Estimated
10-mile
Vehicle
Ownership
346,717
816,437
Annual
Average
Traffic
Data1
35,700
202,900
VMT
(thousands)
170,934
170,934
1 Daily Average Traffic Data reflects 2006 data from the Illinois DOT
BOLD = EPA-designated NATTS Site
Observations from Table 11-2 include the following:
• Cook County had the second highest county population and fourth highest county-
level vehicle registration compared to all counties with NATTS or UATMP sites.
• The 10-mile radius population and estimated vehicle ownership were higher near
SPIL than NBIL.
11-6
-------
• The vehicle per person ratio for these sites was the fourth lowest compared to other
NATTS or UATMP sites.
• SPIL experienced a higher annual average traffic volume than NBIL. SPIL's traffic
volume was the fifth highest of all UATMP and NATTS sites, behind CELA, SEW A,
PRRI, and PXSS.
• The Chicago area VMT ranked third among urban areas with UATMP or NATTS
sites.
11.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Illinois on sampling days, as well as over the course of the year.
11.2.1 Climate Summary
Daily weather fluctuations are common for the Chicago area. The proximity of Chicago
to Lake Michigan offers moderating effects from the continental climate of the region. In the
summertime, afternoon lake breezes can cool the city when winds from the south and southwest
push temperatures upward. The origin of an air mass determines the amount and type of winter
precipitation. The largest snowfalls tend to occur when cold air masses flow southward over
Lake Michigan. Wind speeds average around 10 mph, but can be greater due to the winds
channeling between tall buildings downtown (Ruffner and Bair, 1987).
11.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at Palwaukee Municipal Airport (near NBIL) and O'Hare
International Airport (near SPIL), WBAN 04838 and 94846, respectively.
Table 11-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
11-7
-------
Table 11-3. Average Meteorological Conditions near the Illinois Monitoring Sites
Site
NBIL
SPIL
Closest NWS
Station and
WBAN
Palwaukee
Municipal
Airport
04838
O'Hare
International
Airport
94846
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
59.89
±5.42
59.13
±2.30
60.47
±5.62
59.52
±2.32
Average
Temperature
(op)
52.00
±4.98
51.09
±2.13
52.46
±5.18
51.58
±2.15
Average
Dew Point
Temperature
(°F)
40.50
±4.66
39.64
±2.00
40.01
±4.78
39.39
±1.98
Average
Wet Bulb
Temperature
(»F)
46.31
±4.42
45.48
± 1.09
46.30
±4.54
45.58
±1.89
Average
Relative
Humidity
(%)
68.03
±3.07
67.77
± 1.23
65.79
±3.30
66.16
±1.31
Average
Sea Level
Pressure
(mb)
1017.08
±1.60
1017.42
±0.67
1016.87
± 1.61
1016.97
±0.66
Average
Scalar Wind
Speed
(kt)
6.89
±0.72
7.01
±0.33
8.54
±0.73
8.63
±0.33
BOLD = EPA-designated NATTS Site
oo
-------
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 11-3 is the 95 percent
confidence interval for each parameter. As shown in Table 11-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
11.2.3 Composite Back Trajectories for Sampling Days
Figures 11-4 and 11-5 are composite back trajectory maps for the Illinois monitoring sites
for the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the sites in Figures 11-4 and 11-5 represents 100 miles.
Observations from Figures 11-4 and 11-5 include the following:
• Back trajectories originated from a variety of directions at the sites, although less
frequently from the east and southeast. The predominant direction of trajectory origin
is from the southwest and northwest.
• The 24-hour air shed domains were larger for these sites than for most other
monitoring sites. The furthest away a trajectory originated was north-central
Montana, approximately 1,000 miles away. However, nearly 80 percent of
trajectories originated within 500 miles of the sites.
11.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations at Palwaukee Municipal Airport (for NBIL)
and O'Hare International Airport (for SPIL) were uploaded into a wind rose software program,
WRPLOT (Lakes, 2006) to produce customized wind roses. A wind rose shows the frequency of
wind directions on a 16-point compass, and uses different shading to represent wind speeds.
Figures 11-6 and 11-7 are the wind roses for the Illinois monitoring sites on days that samples
were collected.
Observations from Figure 11-6 for NBIL include the following:
• Winds from a variety of directions were observed near NBIL, although southeasterly
winds were observed the least.
11-9
-------
Figure 11-4. Composite Back Trajectory Map for NBIL
-------
Figure 11-5. Composite Back Trajectory Map for SPIL
-------
Figure 11-6. Wind Rose for NBIL Sampling Days
10%
vi ;s
| 2- 4
Calms: 15.51%
Figure 11-7. Wind Rose for SPIL Sampling Days
11-12
-------
• Calm winds were observed for nearly 16 percent of the hourly measurements. Winds
exceeding 11 knots made up approximately 14 percent of observations and were most
often out of the south or southwest.
Observations from Figure 11-7 for SPIL include the following:
• The wind rose for SPIL is similar to the wind rose for NBIL, in regards to the wind
direction observations.
• Calm winds were observed for five percent of the hourly measurements. Winds
exceeding 11 knots made up approximately 24 percent of observations and were most
often out of the south or southwest.
11.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Illinois
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 11-4 presents the pollutants that failed at least one screen for each Illinois monitoring site
and highlights each site's pollutants of interest (shaded). NBIL sampled for VOC, carbonyls,
SNMOC, metals (PMio), and hexavalent chromium; SPIL sampled for VOC and carbonyls only.
Observations from Table 11-4 include the following:
• Although NBIL sampled more pollutants groups than SPIL, the total number of failed
screens and pollutants failing screens was higher for SPIL.
• Eighteen pollutants with a total of 421 measured concentrations failed screen for
NBIL.
• Twelve pollutants with a total of 432 measured concentrations failed screens for
SPIL.
• Eight pollutants of interest were common to both sites: acetaldehyde, acrolein,
benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde, /?-dichlorobenzene, and
tetrachl oroethy 1 ene.
11-13
-------
Table 11-4. Comparison of Measured Concentrations and EPA Screening Values for the
Illinois Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Northbrook, Illinois - NBIL
Carbon Tetrachloride
Benzene
Arsenic (PM10)
Acrolein
Acetaldehyde
1,3 -Butadiene
Manganese (PM10)
Tetrachloroethylene
£>-Dichlorobenzene
Formaldehyde
Dichloromethane
Nickel (PM10)
Chloroform
Acrylonitrile
1 ,2-Dichloroethane
Hexachloro- 1 ,3 -butadiene
Trichloroethylene
Hexavalent Chromium
Total
60
60
56
55
42
38
33
29
17
15
4
3
2
2
2
1
1
1
421
60
60
58
55
58
56
58
59
44
58
60
58
60
2
3
1
39
45
834
100.00
100.00
96.55
100.00
72.41
67.86
56.90
49.15
38.64
25.86
6.67
5.17
3.33
100.00
66.67
100.00
2.56
2.22
50.48
14.25
14.25
13.30
13.06
9.98
9.03
7.84
6.89
4.04
3.56
0.95
0.71
0.48
0.48
0.48
0.24
0.24
0.24
14.25
28.50
41.81
54.87
64.85
73.87
81.71
88.60
92.64
96.20
97.15
97.86
98.34
98.81
99.29
99.52
99.76
100.00
Schiller Park, Illinois - SPIL
Acetaldehyde
Benzene
Formaldehyde
Acrolein
Carbon Tetrachloride
1,3 -Butadiene
Tetrachloroethylene
£>-Dichlorobenzene
Trichloroethylene
Acrylonitrile
Dichloromethane
Chloromethylbenzene
Total
59
58
57
57
57
54
46
20
17
4
2
1
432
60
58
60
57
58
57
58
49
50
4
57
1
569
98.33
100.00
95.00
100.00
98.28
94.74
79.31
40.82
34.00
100.00
3.51
100.00
75.92
13.66
13.43
13.19
13.19
13.19
12.50
10.65
4.63
3.94
0.93
0.46
0.23
13.66
27.08
40.28
53.47
66.67
79.17
89.81
94.44
98.38
99.31
99.77
100.00
11-14
-------
• Of the eight common pollutants of interest, 100 percent of the measured detections of
acrolein and benzene failed screens for NBIL and SPIL.
• Of the pollutants with at least one failed screen, 50 percent of measurements failed
screens for NBIL, while 76 percent failed screens for SPIL.
11.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Illinois monitoring sites. The averages presented are provided for the pollutants of interest
for each site. Complete site-specific statistical summaries are provided in Appendices J through
O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
11.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 11-5, where applicable.
Observations for NBIL from Table 11-5 include the following:
• The pollutants with the highest daily average concentrations by mass were benzene
(0.82 ± 0.38 (ig/m3), formaldehyde (0.79 ± 0.12 |ig/m3), and acetaldehyde (0.73 ±
0.11 |ig/m3).
• As shown in Tables 4-9 through 4-11, of the program-level pollutants of interest,
NBIL had the fifth highest daily average concentration of arsenic (PMio) and third
highest daily average concentration of />-dichlorobenzene. In addition, the NBIL
daily average concentration of carbon tetrachloride was among the 10 highest average
concentrations for all NATTS and UATMP sites. However, concentrations of carbon
tetrachloride were fairly uniform across the sites.
11-15
-------
Table 11-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Illinois Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(Hg/m3)
Summer
Average
(jig/m3)
Autumn
Average
(jig/m3)
Annual
Average1
(jig/m3)
Northbrook, Illinois - NBIL
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Manganese (PM10)
Tetrachloroethylene
58
55
58
60
56
60
44
58
58
59
58
60
58
60
60
60
60
58
58
60
0.73
±0.11
0.54
±0.22
0.01
±0.01
0.82
±0.38
0.05
±0.01
0.66
±0.03
0.33
±0.19
0.79
±0.12
0.01
±O.01
0.25
±0.07
0.83
±0.23
0.42
±0.31
0.01
±0.01
0.75
±0.42
0.05
±0.01
0.63
±0.07
0.30
±0.31
1.01
±0.24
0.01
±O.01
0.18
±0.05
0.37
±0.17
0.68
±0.62
0.01
±0.01
0.50
±0.15
0.04
±0.01
0.69
±0.07
0.31
±0.36
0.47
±0.14
0.01
±O.01
0.17
±0.06
0.80
±0.11
0.53
±0.34
0.01
±0.01
0.77
±0.46
0.05
±0.01
0.62
±0.06
0.24
±0.29
1.00
±0.29
0.01
± O.01
0.33
±0.20
0.93
±0.24
0.35
±0.07
0.01
±0.01
1.27
± 1.34
0.06
±0.02
0.69
±0.04
0.18
±0.13
0.72
±0.15
0.01
±O.01
0.33
±0.14
0.73
±0.11
0.50
±0.20
0.01
±0.01
0.82
±0.38
0.05
±0.01
0.66
±0.03
0.26
±0.15
0.79
±0.12
0.01
±O.01
0.25
±0.07
Schiller Park, Illinois - SPIL
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
Trichloroethylene
60
57
58
57
58
49
60
58
50
60
58
58
58
58
58
60
58
58
1.40
±0.14
0.41
±0.06
0.84
±0.12
0.12
±0.02
0.69
±0.04
0.15
±0.06
2.40
±0.28
0.39
±0.07
0.60
±0.25
1.35
±0.35
0.26
±0.07
0.72
±0.17
0.12
±0.03
0.65
±0.07
0.04
±0.01
1.55
±0.43
0.30
±0.10
0.29
±0.22
1.25
±0.17
0.33
±0.07
0.62
±0.13
0.09
±0.03
0.71
±0.06
0.16
±0.15
2.17
±0.49
0.25
±0.05
0.27
±0.10
1.22
±0.23
0.61
±0.19
0.92
±0.25
0.13
±0.03
0.65
±0.11
0.21
±0.13
3.16
±0.50
0.51
±0.19
0.59
±0.26
1.79
±0.28
0.42
±0.06
1.15
±0.29
0.15
±0.04
0.73
±0.06
0.12
±0.05
2.69
±0.44
0.52
±0.17
1.00
±0.79
1.40
±0.14
0.40
±0.06
0.84
±0.12
0.12
±0.02
0.69
±0.04
0.13
±0.06
2.40
±0.28
0.39
±0.07
0.53
±0.22
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
11-16
-------
• Concentrations of most of the pollutants of interest for NBIL did not vary
significantly from season to season, although concentrations of formaldehyde and
acetaldehyde were lowest during the spring.
Observations for SPIL from Table 11-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (2.40 ± 0.28 |ig/m3), acetaldehyde (1.40 ± 0.14 |ig/m3), and benzene
(0.84 ± 0.12 |ig/m3). The acetaldehyde and formaldehyde concentrations were
significantly higher for SPIL than for NBIL.
• As shown in Table 4-11, of the program-level pollutants of interest, SPIL had the
third highest daily average concentration of tetrachloroethylene, the seventh highest
daily average concentration of 1,3-butadiene, and tenth highest daily average
concentration of />-dichlorobenzene. In addition, the daily average concentration of
carbon tetrachloride was among the 10 highest average concentrations for all NATTS
and UATMP sites. However, concentrations of carbon tetrachloride were fairly
uniform across the sites.
• Concentrations of most of the pollutants of interest for SPIL did not vary significantly
from season to season, although concentrations of formaldehyde were higher during
the warmer seasons.
• Trichloroethylene appeared to be considerably higher during autumn. However, the
large confidence interval indicates that outlier(s) were affecting the average.
11.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. NBIL and SPIL have sampled VOC under the UATMP and/or
NATTS since 2003. Figures 11-8 through 11-11 present the three-year rolling statistical metrics
graphically for benzene and 1,3-butadiene for both sites. The statistical metrics presented for
assessing trends include the substitution of zeros for non-detects.
Observations from Figure 11-8 for benzene measurements at NBIL include the following:
• The maximum benzene concentration shown was measured in 2004.
• The rolling median and average concentrations have a decreasing trend over the time
periods shown.
11-17
-------
Figure 11-8. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at NBIL
oo
1.20
1.00
.o
o.
&
=
o
'•3 o.e
=
01
u
=
o
U
0.40
0.00
2003-2005
2004-2006
Three- Year Period
2005-2007
IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 11-9. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at NBIL
0.16 -1
0.14
0.12
^ 0.10
.Q
o.
a
a
I 0.08
"a
01
tj
a
o
VO
0.04
0.02
2003-2005
2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 11-10. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at SPIL
to
o
1.80 -i
1.60 -
1.40 -
1.00 -
=
_o
"S
§ 0.80
=
o
U
o.e
0.40 -
2003-2005
2004-2006
Three-Year Period
2005-2007
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 11-11. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at SPIL
o
U
n j^n
n so
n zin
n in
n 90
n i n
n on
1 liilS
'
>
2003-2005 2004-2006 2005-2007
Three-Year Period
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
• All benzene concentrations reported to AQS over the five years of sampling were
measured detections.
Observations from Figure 11-9 for 1,3-butadiene measurements at NBIL include the
following:
• The rolling metrics for 1,3-butadiene look very different than the rolling metrics for
benzene due to the impact of the frequency of detection. The minimum, first quartile,
and median concentrations for 1,3-butadiene during the 2003-2005 and 2004-2006
time frames were zero.
• As the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for this
pollutant increased. This pollutant was detected in 31 percent of samples during the
2003-2005 time frame; 49 percent of samples during 2004-2006; and 75 percent of
samples during 2005-2007.
• As the detection rate increased, the median value increased as well. The rolling
median and average concentrations shown for the 2005-2007 time frames are the
most similar of the periods, which indicates less variability in the central tendency
during 2005-2007.
Observations from Figure 11-10 for benzene measurements at SPIL include the
following:
• The maximum benzene concentration shown was measured in 2005, which explains
why the maximum concentration for each time period was the same.
• Similar to NBIL, the median and average rolling concentrations have a decreasing
trend over the time periods shown.
• All benzene concentrations reported to AQS over the five years of sampling were
measured detections.
Observations from Figure 11-11 for 1,3-butadiene measurements at SPIL include the
following:
• The minimum and first quartile for 1,3-butadiene during the 2003-2005 and 2004-
2006 time frames were zero, similar to NBIL. However, the rolling average and
median concentrations were close together for each time frame for SPIL, which
indicates less variability in the central tendency for this site.
• The detection rate for 1,3-butadiene also increased over the period. But the detection
rate for SPIL was higher than NBIL during each time frame. This pollutant was
11-22
-------
detected in 59 percent of samples during the 2003-2005 time frame; 73 percent of
samples during 2004-2006; and 87 percent of samples during 2005-2007.
• The rolling average and median concentrations changed little across the time frames
shown.
11.5 Pearson Correlations
Table 11-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for NBIL from Table 11-6 include the following:
• Most of the correlations between the pollutants of interest and the meteorological
parameters were less than 0.50 or greater than -0.50, which indicates that these
meteorological parameters have little influence on the concentrations of these
pollutants.
• However, the majority of the correlations with the temperature and moisture
parameters were positive, indicating that as the temperature and moisture content
increase, concentrations of the pollutants of interest may proportionally increase at
NBIL.
• In addition, most of the correlations with scalar wind speed were negative, indicating
that as wind speed decreases, concentrations of the pollutants of interest may increase
at NBIL.
Observations for SPIL from Table 11-6 include the following:
• Formaldehyde and acrolein exhibited strong positive correlations with the
temperature and moisture parameters, indicating that as the temperature and moisture
content increase, concentrations of these pollutants proportionally increase at SPIL.
• Although most of the correlations between the pollutants of interest and the
temperature and moisture parameters were less than 0.50 or greater than -0.50, they
were mostly positive, indicating that as the temperature and moisture content
increase, concentrations of the pollutants of interest may proportionally increase at
SPIL.
• All of the correlations with scalar wind speed were negative, indicating that as wind
speed decreases, concentrations of the pollutants of interest may increase at SPIL.
11-23
-------
Table 11-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Illinois
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Northbrook, Illinois - NBIL
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (PM10)
Tetrachloroethylene
58
55
58
60
56
60
44
58
58
59
0.01
0.19
0.34
0.21
0.10
-0.07
0.09
-0.02
0.32
0.35
-0.03
0.21
0.36
0.21
0.07
-0.05
0.11
-0.04
0.30
0.34
0.03
0.16
0.40
0.20
0.06
-0.06
0.04
-0.02
0.21
0.33
0.00
0.17
0.38
0.20
0.06
-0.07
0.07
-0.03
0.25
0.34
0.21
-0.15
0.13
-0.04
0.01
0.02
-0.24
0.04
-0.30
-0.06
-0.01
0.06
-0.10
-0.11
0.09
0.11
0.06
0.12
-0.02
-0.07
-0.46
0.19
-0.43
-0.04
-0.34
0.01
0.32
-0.24
-0.16
-0.33
Schiller Park, Illinois - SPIL
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
Trichloroethylene
60
57
58
57
58
49
60
58
50
0.00
0.49
0.25
-0.05
0.08
0.31
0.62
0.21
0.27
-0.03
0.50
0.24
-0.05
0.08
0.32
0.61
0.20
0.23
-0.03
0.48
0.26
-0.02
0.02
0.29
0.56
0.20
0.25
-0.03
0.50
0.24
-0.04
0.06
0.31
0.59
0.20
0.24
-0.05
-0.11
0.04
0.11
-0.19
-0.13
-0.24
-0.05
0.01
0.13
-0.04
0.02
0.05
-0.05
-0.03
0.00
-0.02
0.00
-0.30
-0.27
-0.47
-0.45
-0.09
-0.22
-0.35
-0.41
-0.42
to
-------
11.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
11.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Illinois
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 11-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 11-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• For both sites, all of the seasonal averages of acrolein exceeded the intermediate
MRL.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
11.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Illinois monitoring sites and where
the annual average concentrations could be calculated, risk was further examined by reviewing
cancer and noncancer risk estimates from NATA and calculating cancer and noncancer surrogate
risk approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
11-25
-------
Table 11-7. MRL Risk Screening Assessment Summary for the Illinois Monitoring Sites
Site
NBIL
SPIL
Method
TO-15
TO-15
Pollutant
Acrolein
Acrolein
ATSDR
Acute
MRL
(Hg/m3)
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/55
0/57
ATSDR
Intermediate
MRL
(Hg/m3)
0.09
0.09
Winter
Average
(Hg/m3)
0.42
±0.31
0.26
±0.07
Spring
Average
(Hg/m3)
0.68
±0.62
0.33
±0.07
Summer
Average
(Hg/m3)
0.53
±0.34
0.61
±0.19
Autumn
Average
(Hg/m3)
0.35
±0.07
0.42
±0.06
ATSDR
Chronic
MRL
(Hg/m3)
—
-
Annual
Average1
(Hg/m3)
0.50
±0.20
0.40
±0.06
BOLD = EPA-designated NATTS Site
~ = an MRL risk factor is not available
BOLD = exceedance of the intermediate or chronic MRL
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
-------
noncancer surrogate risk approximations are presented in Table 11-8. The data from NATA are
presented for the census tract where each monitoring site is located. The pollutants of interest
for each site are bolded.
The census tract information for the Illinois monitoring sites is as follows:
• The census tract for NBIL is 17031801500, which had a population of 6,227, and
represented approximately 0.1 percent of the Cook County population in 2000.
• The census tract for SPIL is 17031811600, which had a population of 6,372, and also
represented approximately 0.1 percent of the county population in 2000.
Observations for NBIL from Table 11-8 include the following:
• The pollutants with the highest concentrations according to NATA were
formaldehyde, acetaldehyde, and benzene.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadiene, and acetaldehyde.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (8.98).
• The pollutants with the highest 2007 annual averages were chloroform, benzene, and
formaldehyde, which were all lower than the modeled concentrations from NATA.
• The pollutants with the highest surrogate cancer risk approximations were carbon
tetrachloride, benzene, and hexachloro-l,3-butadidne.
• Acrolein was the only pollutant with a surrogate noncancer risk approximation
greater than 1.0 (24.84), although this approximation was three times the NATA-
modeled noncancer risk.
Observations for SPIL from Table 11-8 include the following:
• The pollutants with the highest concentrations according to NATA were
acetaldehyde, formaldehyde, and benzene, similar to NBIL.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadiene, and acetaldehyde, similar to NBIL.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (11.07).
11-27
-------
Table 11-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Illinois
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Northbrook, Illinois (NBIL) - Census Tract ID 17031801500
Acet aldehyde
Acrolein
Acrylonitrile
Arsenic (PM10)
Benzene
1,3-Butadiene
Carbon Tetrachloride
Chloroform
p-Dichlorobenzene
1 ,2-Dichloroethane
Dichloromethane
Formaldehyde
Hexachloro- 1 ,3 -butadiene
Hexavalent Chromium
Manganese (PM10)
Nickel (PM10)
Tetrachloroethylene
Trichloroethylene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.000015
~
0.000011
0.000026
0.00000047
5.5E-09
0.000022
0.012
~
0.00016
0.000005
0.000002
0.009
0.00002
0.002
0.00003
0.03
0.002
0.04
0.098
0.8
2.4
1
0.0098
0.09
0.0001
0.00005
0.000065
0.27
0.6
2.71
0.18
0.01
0.01
2.63
0.32
0.21
0.11
0.04
0.05
0.62
2.73
O.01
O.01
O.01
O.01
0.24
0.25
5.98
—
0.06
0.06
20.55
9.59
3.22
~
0.43
1.24
0.29
0.01
0.03
0.73
~
0.05
1.43
0.51
0.30
8.98
0.01
0.01
0.08
0.15
0.01
O.01
0.01
0.01
0.01
0.27
O.01
O.01
0.01
0.01
0.01
0.01
0.73 ±0.11
0.50 ±0.20
0.03 ± 0.01
0.01 ±0.01
0.82 ±0.38
0.05 ±0.01
0.66 ±0.03
0.83 ±0.51
0.26 ±0.15
0.04 ±0.01
0.62 ±0.17
0.79 ±0.12
0.19 ±O.01
O.01±O.01
0.01 ±O.01
O.01±O.01
0.25 ±0.07
0.14 ±0.04
1.46
—
1.74
3.71
5.73
1.50
9.87
~
2.82
1.11
0.29
0.01
4.23
0.26
~
0.18
1.25
0.28
0.08
24.84
0.01
0.03
0.03
0.02
0.02
0.01
0.01
0.01
0.01
0.08
O.01
O.01
0.16
0.02
0.01
0.01
to
oo
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 11-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Illinois (Continued)
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Schiller Park, Illinois (SPIL) - Census Tract ID 17031811600
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
Chloromethylbenzene
p-Dichlorobenzene
Dichloromethane
Formaldehyde
Tetrachloroethylene
Trichloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000049
0.000011
0.00000047
5.5E-09
0.000005
0.000002
0.009
0.00002
0.002
0.03
0.002
0.04
~
0.8
1
0.0098
0.27
0.6
3.31
0.22
0.01
2.79
0.31
0.21
O.01
0.06
1.11
2.99
0.41
1.72
7.32
—
0.05
21.78
9.21
3.16
<0.01
0.64
0.54
0.01
2.41
3.45
0.36
11.07
0.01
0.09
0.15
0.01
~
O.01
0.01
0.30
0.01
0.01
1.40 ±0.14
0.40 ± 0.06
0.03 ± 0.01
0.84 ±0.12
0.12 ±0.02
0.69 ±0.04
0.03 ± O.01
0.13 ±0.06
0.59 ±0.14
2.40 ±0.28
0.39 ±0.07
0.53 ±0.22
2.80
—
1.76
5.91
3.69
10.29
1.36
1.45
0.28
0.01
1.96
1.05
0.16
20.22
0.01
0.03
0.06
0.02
~
O.01
0.01
0.25
0.01
0.01
to
VO
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
• The pollutants with the highest 2007 annual averages were formaldehyde,
acetaldehyde, and benzene.
• The pollutants with the highest surrogate cancer risk approximations were carbon
tetrachloride, 1,3-butadiene, and acetaldehyde.
• Acrolein was the only pollutant with a noncancer risk approximation greater than 1.0
(20.22), which was twice the modeled risk from NATA.
11.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 11-9 and 11-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 11-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
surrogate cancer risk approximations (in-a-million), as calculated from the annual averages.
Table 11-10 presents similar information, but identifies the 10 pollutants with the highest
surrogate noncancer risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 11.3, SPIL sampled for VOC
and carbonyl compounds. NBIL sampled for these pollutants as well, but also sampled for
SNMOC, metals, and hexavalent chromium. In addition, the cancer and noncancer risk
approximations are limited to those sites sampling for a long enough period for annual averages
to be calculated. NBIL and SPIL sampled year-round for each pollutant group mentioned above.
Observations from Table 11-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Cook County.
11-30
-------
Table 11-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Illinois
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentrations
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Northbrook, Illinois (NBIL) - Cook County
Benzene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
£>-Dichlorobenzene
1,3 -Butadiene
Trichloroethylene
Dichloromethane
Naphthalene
1 ,3 -Dichloropropene
3,598.91
2,321.18
1,270.31
1,167.17
523.43
470.95
420.80
316.75
256.74
89.83
Benzene
1,3 -Butadiene
Arsenic, PM
Hexavalent Chromium
Coke Oven Emissions
Naphthalene
Tetrachloroethylene
/>-Dichlorobenzene
Acetaldehyde
Cadmium, PM
2.81E-02
1.41E-02
1.32E-02
1.05E-02
1.04E-02
8.73E-03
6.89E-03
5.76E-03
2.79E-03
2.52E-03
Carbon Tetrachloride
Benzene
Hexachloro- 1 ,3 -butadiene
Arsenic
£>-Dichlorobenzene
Acrylonitrile
1,3 -Butadiene
Acetaldehyde
Tetrachloroethylene
1 ,2-Dichloroethane
9.87
5.73
4.23
3.71
2.82
.74
.50
.46
.25
.11
Schiller Park, Illinois (SPIL) - Cook County
Benzene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
£>-Dichlorobenzene
1,3 -Butadiene
Trichloroethylene
Dichloromethane
Naphthalene
1 ,3 -Dichloropropene
3,598.91
2,321.18
1,270.31
1,167.17
523.43
470.95
420.80
316.75
256.74
89.83
Benzene
1,3 -Butadiene
Arsenic, PM
Hexavalent Chromium
Coke Oven Emissions
Naphthalene
Tetrachloroethylene
/>-Dichlorobenzene
Acetaldehyde
Cadmium, PM
2.81E-02
1.41E-02
1.32E-02
1.05E-02
1.04E-02
8.73E-03
6.89E-03
5.76E-03
2.79E-03
2.52E-03
Carbon Tetrachloride
Benzene
1,3 -Butadiene
Acetaldehyde
Tetrachloroethylene
Acrylonitrile
/>-Dichlorobenzene
Chloromethylbenzene
Trichloroethylene
Dichloromethane
10.29
5.91
3.69
2.80
1.96
1.76
1.45
1.36
1.05
0.28
-------
Table 11-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Illinois
to
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Northbrook, Illinois (NBIL) - Cook County
Toluene
Xylenes
Benzene
Methanol
Formaldehyde
Hexane
Ethylbenzene
Methyl isobutyl ketone
Acetaldehyde
Tetrachloroethylene
12,266.89
8,434.64
3,598.91
3,403.96
2,321.18
1,950.17
1,559.68
1,483.65
1,270.31
1,167.17
Acrolein
Formaldehyde
1,3 -Butadiene
Manganese, PM
Acetaldehyde
Benzene
Bromomethane
Nickel, PM
Arsenic, PM
Naphthalene
5,378,964.91
236,855.60
235,474.70
155,030.41
141,145.03
119,963.72
113,355.88
105,702.86
101,996.12
85,581.25
Acrolein
Manganese
Acetaldehyde
Formaldehyde
Arsenic
Benzene
1,3 -Butadiene
Nickel
Carbon Tetrachloride
Acrylonitrile
24.84
0.16
0.08
0.08
0.03
0.03
0.02
0.02
0.02
0.01
Schiller Park, Illinois (SPIL) - Cook County
Toluene
Xylenes
Benzene
Methanol
Formaldehyde
Hexane
Ethylbenzene
Methyl isobutyl ketone
Acetaldehyde
Tetrachloroethylene
12,266.89
8,434.64
3,598.91
3,403.96
2,321.18
1,950.17
1,559.68
1,483.65
1,270.31
1,167.17
Acrolein
Formaldehyde
1,3 -Butadiene
Manganese, PM
Acetaldehyde
Benzene
Bromomethane
Nickel, PM
Arsenic, PM
Naphthalene
5,378,964.91
236,855.60
235,474.70
155,030.41
141,145.03
119,963.72
113,355.88
105,702.86
101,996.12
85,581.25
Acrolein
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Benzene
Carbon Tetrachloride
Acrylonitrile
Tetrachloroethylene
Trichloroethylene
Dichloromethane
20.22
0.25
0.16
0.06
0.03
0.02
0.01
0.01
0.01
O.01
-------
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) for Cook County were benzene, 1,3-butadiene, and arsenic.
• Six of the highest emitted pollutants in Cook County also had the highest toxicity-
weighted emissions.
• For both monitoring sites, carbon tetrachloride and benzene had the highest surrogate
cancer risk approximations. Carbon tetrachloride did not appear on either emissions-
based list, while benzene ranked highest on both.
Observations from Table 11-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Cook County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) for Cook County were acrolein, formaldehyde, and 1,3-butadiene.
• Three of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• The pollutant with the highest noncancer risk approximation was acrolein. Acrolein
was also the pollutant with the highest toxicity-weighted emissions, yet this
pollutant's emissions ranked 26th for Cook County.
11.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Illinois monitoring site were acetaldehyde,
acrolein, benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde,
p-dichlorobenzene, and tetrachloroethylene.
»«» Formaldehyde, benzene, and acetaldehyde had the highest daily average
concentration for both of the monitoring sites.
»«» Seasonal averages of acrolein exceeded the A TSDR intermediate MRL health
benchmark for both sites.
11-33
-------
12.0 Sites in Indiana
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the UATMP sites in Indiana, and integrates these concentrations with
emissions, meteorological, and risk information.
12.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. Three Indiana sites (ININ,
IDIN, and WPIN) are located in the Indianapolis-Carmel, IN MSA. INDEM is located in the
Chicago-Naperville-Joliet, IL-IN-WI MSA. Figures 12-1 through 12-4 are composite satellite
images retrieved from Google™ Maps showing the monitoring sites in their urban locations.
Figures 12-5 through 12-7 identify point source emission locations within 10 miles of each site
as reported in the 2002 NEI for point sources. Table 12-1 describes the area surrounding each
monitoring site and provides supplemental geographical information such as land use, location
setting, and locational coordinates.
IDIN is located in southwest Indianapolis at Stout Field, a National Guard Armory and
former airfield. Figure 12-1 shows that the area surrounding IDIN is fairly industrialized, with
Olin Brass and Reilly Tar and Chemical just to the east of the monitoring site. The placement of
this site is based on results from NATA. Heavily traveled roadways, including 1-70, are located
less than a mile from the monitoring site.
ININ is located in central Indianapolis, about a half-mile south of 1-70. Residential areas
are located to the west of the site, while industrial areas are located to the east, as shown in
Figure 12-2. The placement of this site is also based on results from NATA.
WPIN is located in northeast Indianapolis, at Washington Park near East 30th Street.
Figure 12-3 shows that the area surrounding WPIN is suburban and residential, with little
industry in close proximity.
12-1
-------
Figure 12-1. Indianapolis, Indiana (IDIN) Monitoring Site
to
to
,^i™r;r -
. • ii tyfoMifl
!:;
• v1" "»-^B«'rji^^5^.-i; T
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If. JJJ^^gHgfiEgj . £r-_ jl
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©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 12-2. Indianapolis, Indiana (ININ) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 12-3. Indianapolis, Indiana (WPIN) Monitoring Site
to
w. TTBM5W *
—» —T f i- , ...
©2008 Google/ONAVTECH
-------
Figure 12-4. Gary, Indiana (INDEM) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 12-5. NEI Point Sources Located Within 10 Miles of IDIN, ININ, and WPIN
WPIN UATMP site
Legend
•fr IDIN UATMP site
* ININ UATMP srle
Source Category Group (No, of Facilities)
C Chemicals & Allied Products Facility (8)
z Electrical & Electronic Equipment Facilrty (2)
D Fabricated Metal Products Facility {9J
F Fuel Combustion Industrial Facility (61)
I Incineration Industrial Facility (3)
J Industrial Machinery S Equipmenl Facility (1)
> Integrated lion & Steel Manufacturing Facility (3)
l Liquids Distribution Industrial Facility (5)
* Lumber & Wood Products Facility (1)
B Mircfaf Products Processing industrial Facility ($}
>; Miscetlaneous Manufacturing Industries (2>
P Miscellaneous Processes Industnal Facility (6)
\ Non-ferrous Metals Processing Industrial Facility (1)
•lot* Ou* (o fKilly dtmili «vd w»«a«K)n Iti* Ittal todUxt
dlspiaytd nay nol r«pres*ot al fadlnie* wdtm ttv* ««a o* n!er«it
10 mile radius
| I County boundary
» Ptiarmaceubcal Production Processes Industiial Facility (3)
v Polyniers & Resins Production Industrial Facility (2)
ft Printing & Publishing Facility (5)
4 Production of Organic Chemicals Industrial Facility (6)
1 Pail road Transportation (1)
¥ Rubber & Miscellaneous Plastic Products Facility (2)
u Stone. Clay, Glass, & Concrete Products (1)
S Surface Coaling Processes Industrial Facility (8)
* Unknown (2)
8 Utility Boilers (3)
Waste Treatment & Disposal Industrial Facility (3)
r Wholesale Trade (2)
t Wholesale Trade • Durable Goods ( 1 }
* Wood Furniture Facility (1)
12-6
-------
Figure 12-6. NEI Point Sources Located Within 10 Miles of INDEM
•
tlot«. Due EotKiUiy de*i*flj wvd eofcocKwn.mnertil fitiHM*
*y not r«$ir
*ittw th* M«a cl rrt*f*st
Legend
tSr iNOEMUATMPslte
10 mile radius
Source Category Group (No. of Facilities)
-- Business Services Facility (1)
C Chemicals & Allied Products Facility (2)
D Fabricated Metal Products Facility (3)
K Ferrous Metals Processing Industrial Facility (3)
F Fuel Combustion Industrial Facility (38)
J Industrial Machinery & Equipment Facility (2)
f Integrated Iron & Steel Manufacturing Facility (1)
L Liquids Distribution Industrial Facility (12)
B Mineral Products Processing Industrial Facility (8)
x Miscellaneous Manufacturing Industries (1)
County boundary
P Miscellaneous Processes Industrial Facility (3)
\ Non-ferrous Metals Processing Industrial Facility (3)
2 Nonmetallic Minerals, Except Fuels (1)
P Petroleum/Nat. Gas Prod. & Refining Industrial Facility (2)
Q Primary Metal Industries Facility (3)
# Production of Inorganic Chemicals Industrial Facility (2)
i Railroad Transportation (1)
s Surface Coating Processes Industrial Facility (3)
8 Utility Boilers (4)
''. Waste Treatment & Disposal Industrial Facility (2)
t Wholesale Trade (1)
12-7
-------
Table 12-1. Geographical Information for the Indiana Monitoring Sites
Site
Code
IDIN
INDEM
ININ
AQS Code
18-097-0085
18-089-0022
18-097-0057
Location
Indianapolis
Gary
Indianapolis
County
Marion
Lake
Marion
Micro- or
Metropolitan
Statistical Area
Indianapolis-
Carmel, IN
Chicago-
Naperville-Joliet,
IL-IN-WI
Indianapolis-
Carmel, IN
Latitude
and
Longitude
39.740383,
-86.225950
41.606667,
-87.304722
39.748889,
-86.186243
Land Use
Military
Reservation
Industrial
Residential
Location
Setting
Urban/City
Center
Urban/City
Center
Urban/City
Center
Description of the
Immediate Surroundings
This site is located at Stout Field National Guard
Armory. This monitor is strategically located based
on an evaluation of U.S. EPA's 1996 and 1999
NATA; its proximity to major sources for HAP
emissions; its proximity to areas where the public
lives and congregates; and its history of housing
operating monitors. This site monitors for metals,
carbonyls, and VOC.
This site is located on property now owned by the
Dunes National Lakeshore. It is approximately one-
half to three-quarters of a mile south west of the USX
coking battery for their mill. The site is part of the
Chicago PAMS network. It is considered a Type 2 or
source site. Monitoring for ozone, NO/NOX, ozone
precursors, and carbonyls began in 1995 as the
network was deployed in Wisconsin, Illinois, Indiana,
and Michigan. Other parameters monitored at this
location are SO2, PM10, PM2 5, speciated PM2 5, and
several meteorological parameters.
This site is located on South Harding Street. This
monitor is strategically located based on an
evaluation of U.S. EPA's 1996 and 1999 NATA; its
proximity to major sources for HAP emissions; its
proximity to areas where the public lives and
congregates; and its history of housing operating
monitors. This site monitors for metals, carbonyls,
VOC, and hexavalent chromium.
to
oo
-------
Table 12-1. Geographical Information for the Indiana Monitoring Sites (Continued)
Site
Code
WPIN
AQS Code
18-097-0078
Location
Indianapolis
County
Marion
Micro- or
Metropolitan
Statistical Area
Indianapolis-
Carmel, IN
Latitude
and
Longitude
39.811097,
-86.114469
Land Use
Residential
Location
Setting
Suburban
Description of the
Immediate Surroundings
The Washington Park Monitoring Site is located
approximately 3.75 miles from the center of the city
in the northeast part of Indianapolis. The nearest
main roads are 30th St. (40 meters to the south) and
Keystone Ave. (600 meters to the west). The site is
located on the south end of Washington Park in a
mostly residential neighborhood. No significant
industry is located near the site. Washington Park
was established in 1999 as a PM25 and toxics
monitoring location. It collects PM2 5 mass for
compliance purposes, along with PM2 5 speciation
and continuous PM25. Air toxics monitoring began
as one of the sites in the four-city Children's Health
Initiative. Currently, samples collected at the site are
analyzed for sixty -two VOC/HAPS. Carbonyl
compounds and metals are also monitored. It is
considered a long term trends site for Indianapolis.
Future plans include possible designation as an
NCore Site.
to
-------
Figure 12-5 shows that IDIN, ININ, and WPIN are located within 10 miles of many point
sources, most of which are located towards the center of Marion County. Facilities involved in
processes utilizing fuel combustion are the most numerous emission sources in the area.
INDEM is located in Gary, Indiana, a few miles east of the Indiana-Illinois border and
southeast of Chicago. Gary is located on the southernmost bank of Lake Michigan. The site is
just north of 1-90 and 1-65. Although INDEM resides on the Indiana Dunes National Lakeshore,
the surrounding area is highly industrialized, as shown in Figure 12-4. Figure 12-6 shows that
the majority of point sources are located to the west of INDEM. The sources closest to INDEM
are involved in ferrous metals processing or processes utilizing fuel combustion. Similar to
Indianapolis, facilities involved in processes utilizing fuel combustion are the most numerous
sources within the 10-mile radius.
Table 12-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Indiana
monitoring sites. County-level vehicle registration and population data for Marion and Lake
Counties were obtained from the Indiana Bureau of Motor Vehicles and the U.S. Census Bureau.
Table 12-2 also includes a vehicle registration to county population ratio (vehicles per person).
In addition, the population within 10 miles of each site is presented. An estimate of 10-mile
vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 12-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. For the Indianapolis sites, data from 1-70 was
obtained; for INDEM, data for 1-90 was obtained. Finally, Table 12-2 presents the daily VMT
for each urban area.
Observations from Table 12-2 include the following:
• Marion County had almost twice the county population and vehicle registration than
Lake County. The difference between the two counties decreases somewhat when
focusing on the 10-mile population and ownership estimates.
12-10
-------
Table 12-2. Population, Motor Vehicle, and Traffic Information for the Indiana Monitoring
Sites
Site
IDIN
INDEM
ININ
WPIN
2007
Estimated
County
Population
876,804
492,104
876,804
876,804
Number
of
Vehicles
Registered
897,388
453,146
897,388
897,388
Vehicles
per Person
(Registration:
Population)
1.02
0.92
1.02
1.02
Population
Within
10 Miles
594,540
402,562
668,574
790,904
Estimated
10 mile Vehicle
Ownership
608,497
370,693
684,270
809,471
Annual
Average
Traffic
Data1
77,250
40,710
97,780
155,900
VMT
(thousands)
30,572
170,934
30,572
30,572
1 Daily Average Traffic Data reflects 2002 data from the Indiana DOT
• The vehicle per person ratio for the Indianapolis sites was greater than one vehicle per
person and ranked tenth highest compared to other NATTS or UATMP sites.
• WPIN experienced a significantly higher traffic volume than the other Indianapolis
sites, although traffic estimates for all three sites was based on data from 1-70. The
traffic volume near WPIN is the seventh highest among NATTS and UATMP sites.
• Traffic volume for INDEM is nearly half of the lowest traffic volume for Indianapolis
sites with the least traffic.
• The VMT shown for INDEM is based on the urban area of Chicago. The Chicago
area VMT ranked third among urban areas with UATMP or NATTS sites, while the
VMT for the Indianapolis area ranked eighteenth.
12.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Indiana on sampling days, as well as over the course of the year.
12.2.1 Climate Summary
The city of Indianapolis is located in the center of Indiana, and experiences a temperate
continental climate. Summers are warm and often humid, winters are chilly with occasional
Arctic outbreaks, and precipitation is spread rather evenly throughout the year. The prevailing
wind direction is southwesterly. Gary is located to the southeast of Chicago, and at the southern-
most tip of Lake Michigan. Gary's proximity to Lake Michigan is an important factor
controlling the weather of the area. In the summer, warm temperatures can be suppressed, while
cold winter temperatures are often moderated. Winds that blow across Lake Michigan and over
12-11
-------
Gary in the winter can provide abundant amounts of lake-effect snow (Ruffner and Bair, 1987
and Gary, 2007).
12.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at Indianapolis International Airport (near the Indianapolis
monitoring sites) and Lansing Municipal Airport (near INDEM), WBAN 93819 and 04879,
respectively.
Table 12-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 12-3 is the 95 percent
confidence interval for each parameter. As shown in Table 12-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
12.2.3 Composite Back Trajectories for Sampling Days
Figures 12-7 through 12-10 are composite back trajectory maps for the Indiana
monitoring sites for the days on which samples were collected. Each line represents the 24-hour
trajectory along which a parcel of air traveled toward the monitoring site on a sampling day.
Each concentric circle around the sites in Figures 12-7 through 12-10 represents 100 miles.
Observations from Figures 12-7 through 12-9 for the Indianapolis sites include the
following:
• Back trajectories originated from a variety of directions at the Indianapolis sites,
although less frequently from the southeast. The predominant direction of trajectory
origin is from the southwest and northwest.
12-12
-------
Table 12-3. Average Meteorological Conditions near the Indiana Monitoring Sites
Site
IDIN
INDEM
ININ
WPIN
Closest NWS
Station and
WBAN
Indianapolis
Intl Airport
93819
Lansing
Municipal
Airport
04879
Indianapolis
Intl Airport
93819
Indianapolis
Intl Airport
93819
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
65.35
±5.20
64.00
±2.25
58.71
±5.88
57.59
±2.45
64.95
±5.20
64.00
±2.25
64.90
±5.47
64.00
±2.25
Average
Temperature
(°F)
56.96
±4.87
55.16
±2.10
50.56
±5.29
49.28
±2.23
56.47
±4.87
55.16
±2.10
56.35
±5.14
55.16
±2.10
Average
Dew Point
Temperature
(°F)
43.61
±4.27
42.40
±1.86
39.45
±5.03
38.69
±2.12
42.88
±4.20
42.40
±1.86
42.69
±4.45
42.40
±1.86
Average
Wet Bulb
Temperature
(°F)
49.95
±4.15
48.52
±1.81
45.51
±5.09
44.73
±2.17
49.36
±4.12
48.52
±1.81
49.22
±4.36
48.52
±1.81
Average
Relative
Humidity
(%)
64.73
±3.36
65.68
± 1.36
68.69
±3.95
69.96
±1.56
64.28
±3.41
65.68
± 1.36
64.01
±3.45
65.68
± 1.36
Average
Sea Level
Pressure
(mb)
1017.18
±1.46
1017.45
±0.60
NA
NA
1017.18
± 1.41
1017.45
±0.60
1017.43
±1.53
1017.45
±0.60
Average
Scalar Wind
Speed
(kt)
8.28
±0.76
8.13
±0.36
6.58
±0.89
6.98
±0.39
8.25
±0.76
8.13
±0.36
8.14
±0.74
8.13
±0.36
to
NA= Sea level pressure was not recorded at the Lansing Municipal Airport
-------
Figure 12-7. Composite Back Trajectory Map for IDIN
0 50 100 200 300 4&Q
I.I, . -
-------
Figure 12-8. Composite Back Trajectory Map for ININ
o 50 100 200 300 ••.:••:
-------
Figure 12-9 Composite Back Trajectory Map for WPIN
-------
Figure 12-10. Composite Back Trajectory Map for INDEM
-------
• The 24-hour air shed domains were comparable to other monitoring sites. The
furthest away a trajectory originated was west-central Minnesota, or greater than 600
miles away. However, most trajectories originated within 400 miles.
Observations from Figure 12-10 for INDEM include the following:
• Back trajectories originated from a variety of directions at the INDEM site, although
less frequently from the east. Similar to the Indianapolis sites, the predominant
direction of trajectory origin is from the southwest and northwest.
• The 24-hour air shed domain was somewhat larger than the other Indiana monitoring
sites. The furthest away a trajectory originated was western North Dakota, or greater
than 800 miles away. However, most trajectories originated within 500 miles.
12.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations near the Indiana sites, as presented in
Section 12.2.2, were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to
produce customized wind roses. A wind rose shows the frequency of wind directions on a 16-
point compass, and uses different shading to represent wind speeds. Figures 12-11 through 12-
14 are the wind roses for the Indiana monitoring sites on days that samples were collected.
Observations from Figures 12-11 through 12-13 for ID IN, ININ, and WPIN, respectively,
include the following:
• The wind roses for the Indianapolis sites are very similar to each other.
• Winds from a variety of directions were observed near the Indianapolis sites,
although winds with a westerly component were observed more frequently.
• Calm winds were observed for approximately six percent of the hourly
measurements.
• Winds exceeding 11 knots made up approximately 22 percent of observations and
most often had a westerly component.
Observations from Figure 12-14 for INDEM include the following:
• The wind rose for INDEM looks different from the wind roses for the Indianapolis
sites.
12-18
-------
Figure 12-11. Wind Rose for IDIN Sampling Days
Figure 12-12. Wind Rose for ININ Sampling Days
WES
12-19
-------
Figure 12-13. Wind Rose for WPIN Sampling Days
•WEST
10%
•SOUTH .-'
EAST
WIND SPEED
(Knots)
CH >=22
^| 17 - 21
• 11 - 17
• 7- 11
2- 4
Calms: 6.44%
Figure 12-14. Wind Rose for INDEM Sampling Days
NORTH"'--.
15%
SOUTH ,-'
EAST
WIND SPEED
(Knots)
O >=22
• 17 • 21
• 11 - 17
CH 4-7
• 2- 4
Calms: 19.59%
12-20
-------
• Although winds from a variety of directions were observed near INDEM, westerly,
south-southwesterly, and southerly winds were observed most frequently.
• Calm winds were observed for nearly 20 percent of the hourly measurements, more
than twice the frequency of the Indianapolis sites.
• Winds exceeding 11 knots made up approximately 14 percent of observations and
were mostly frequently out of the south or southwest.
12.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Indiana
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 12-4 presents the pollutants that failed at least one screen for each Indiana monitoring site
and highlights each site's pollutants of interest (shaded). ININ sampled for carbonyls, metals
(PMio), and hexavalent chromium; IDIN sampled for carbonyls and metals (PMio); WPIN and
INDEM sampled for carbonyls only.
Observations from Table 12-4 include the following:
• Six pollutants failed screens for IDIN and seven failed screens for ININ. More than
half of the measured concentrations of these pollutants failed screens at these sites.
• Formaldehyde and acetaldehyde are the only carbonyls with risk screening values.
Both pollutants failed screens for INDEM and WPIN. All of the measured
concentrations of these two pollutants failed screens for INDEM and nearly 99
percent failed screens for WPIN.
• Formaldehyde and acetaldehyde were also pollutants of interest for ININ and IDIN.
Manganese and arsenic were the other two pollutants of interest for these sites.
12-21
-------
Table 12-4. Comparison of Measured Concentrations and EPA Screening Values for the
Indiana Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
South Holt, Indianapolis, Indiana - IDIN
Arsenic (PM10)
Acetaldehyde
Formaldehyde
Manganese (PM10)
Nickel (PM10)
Cadmium (PM10)
Total
60
58
58
31
2
1
210
60
59
59
60
60
60
358
100.00
98.31
98.31
51.67
3.33
1.67
58.66
28.57
27.62
27.62
14.76
0.95
0.48
28.57
56.19
83.81
98.57
99.52
100.00
Gary, Indiana - INDEM
Acetaldehyde
Formaldehyde
Total
60
60
120
60
60
120
100.00
100.00
100.00
50.00
50.00
50.00
100.00
South Harding, Indianapolis, Indiana - ININ
Acetaldehyde
Formaldehyde
Arsenic (PM10)
Manganese (PM10)
Cadmium (PM10)
Hexavalent Chromium
Nickel (PM10)
Total
60
60
58
32
5
2
1
218
61
61
60
60
60
47
60
409
98.36
98.36
96.67
53.33
8.33
4.26
1.67
53.30
27.52
27.52
26.61
14.68
2.29
0.92
0.46
27.52
55.05
81.65
96.33
98.62
99.54
100.00
Washington Park, Indianapolis, Indiana - WPIN
Acetaldehyde
Formaldehyde
Total
55
55
110
56
56
112
98.21
98.21
98.21
50.00
50.00
50.00
100.00
12.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Indiana monitoring sites. The averages presented are provided for the pollutants of interest
for each site. Complete site-specific statistical parameters are provided in Appendices J through
O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
12-22
-------
12.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages for the Indiana sites are presented in Table 12-5,
where applicable.
Observations for the Indiana sites from Table 12-5 include the following:
• Formaldehyde exhibited the highest daily average concentration by mass for all four
sites. The daily average concentration of formaldehyde for INDEM was an order of
magnitude higher than the daily averages for the other three sites.
• Formaldehyde concentrations were lowest in the winter at all four sites.
Acetaldehyde concentrations were also lowest in the winter at INDEM and WPIN.
• As shown in Table 4-9, INDEM had the highest daily average concentration of
formaldehyde among all NATTS and UATMP sites, which was an order of
magnitude higher than the next highest daily average of formaldehyde. ININ and
WPIN also had the sixth and seventh highest daily averages of formaldehyde,
respectively.
• INDEM also had the fourth highest daily average concentration of acetaldehyde, as
shown in Table 4-9. IDIN had the second highest daily average concentration of
arsenic, behind only S4MO, among sites sampling arsenic (PMi0), as shown in
Table 4-10.
• The average concentrations of the arsenic and manganese for ININ and IDIN were
generally 0.01 |ig/m3 or less.
12-23
-------
Table 12-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Indiana Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(Hg/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(jig/m3)
Annual
Average1
(Hg/m3)
South Holt, Indianapolis, Indiana - IDIN
Acetaldehyde
Arsenic (PM10)
Formaldehyde
Manganese (PM10)
59
60
59
60
59
60
59
60
2.19
±0.25
O.01
±<0.01
3.67
±0.50
0.01
± 0.01
1.62
±0.43
O.01
±0.01
1.78
±0.40
0.01
±0.01
2.25
±0.35
O.01
±0.01
3.66
±0.82
0.01
±0.01
2.61
±0.60
O.01
±O.01
5.17
±0.83
0.01
±0.01
2.24
±0.45
O.01
±O.01
3.95
±0.95
0.01
±0.01
2.19
±0.25
O.01
±0.01
3.67
±0.50
0.01
±0.01
Gary, Indiana - INDEM
Acetaldehyde
Formaldehyde
60
60
60
60
4.56
±0.52
36.07
±6.34
2.58
±0.24
14.12
±3.15
4.88
± 1.16
34.94
±9.19
6.80
±0.64
64.23
± 14.44
3.89
±0.43
29.92
±3.23
4.56
±0.52
36.07
±6.34
South Harding, Indianapolis, Indiana - ININ
Acetaldehyde
Arsenic (PM10)
Formaldehyde
Manganese (PM10)
61
60
61
60
61
60
61
60
2.02
±0.23
O.01
±<0.01
4.15
±0.71
0.01
± 0.01
1.56
±0.23
O.01
±0.01
2.17
±0.39
0.01
±0.01
2.04
±0.38
O.01
±O.01
3.36
±0.95
0.01
±0.01
2.28
±0.4
O.01
±O.01
5.66
±1.69
0.01
±0.01
2.21
±0.66
O.01
±O.01
5.46
±1.44
0.01
±0.01
2.02
±0.23
O.01
±O.01
4.15
±0.71
0.01
±0.01
Washington Park, Indianapolis, Indiana - WPIN
Acetaldehyde
Formaldehyde
56
56
56
56
2.52
±0.3
4.06
±0.58
1.56
±0.19
1.93
±0.31
2.58
±0.5
3.81
±0.95
3.19
±0.62
5.77
±1.06
2.88
±0.64
5.01
±1.03
2.52
±0.3
4.06
±0.58
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
12.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. None of the Indiana sites have sampled continuously for five years as
part of the National Monitoring Program; therefore, the trends analysis was not conducted.
12-24
-------
12.5 Pearson Correlations
Table 12-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for the Indiana sites from Table 12-6 include the following:
• The correlations for INDEM were weak.
• All of the correlations between the pollutants of interest for the Indianapolis sites and
the maximum, average, dew point, and wet bulb temperatures were positive. The
correlations with formaldehyde and these parameters were strong. In addition,
acetaldehyde exhibited strong positive correlations with these parameters for WPIN.
This indicates that concentrations of the pollutants of interest, especially the
carbonyls, tend to increase with increasing dry bulb, dew point, and wet bulb
temperatures.
• Conversely, the correlations between the pollutants of interest for all four sites and
the relative humidity and scalar wind speed were negative, many of which were
strong. This indicates that concentrations of the pollutants of interest, especially the
carbonyls, tend to increase with decreasing relative humidity and wind speed.
12.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
12.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Indiana
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 12-7. Where a seasonal or annual average exceeds the
12-25
-------
Table 12-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Indiana
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
South Holt, Indianapolis, Indiana - IDIN
Acetaldehyde
Arsenic (PM10)
Formaldehyde
Manganese (PM10)
59
60
59
60
0.48
0.25
0.83
0.42
0.45
0.25
0.81
0.37
0.30
0.22
0.70
0.19
0.37
0.24
0.76
0.28
-0.53
-0.10
-0.54
-0.60
0.09
-0.06
-0.16
0.02
-0.56
-0.31
-0.45
-0.40
Gary, Indiana - INDEM
Acetaldehyde
Formaldehyde
60
60
0.12
0.01
0.14
0.04
0.21
0.11
0.00
-0.01
-0.47
-0.42
—
—
-0.40
-0.39
South Harding, Indianapolis, Indiana - ININ
Acetaldehyde
Arsenic (PM10)
Formaldehyde
Manganese (PM10)
61
60
61
60
0.48
0.34
0.63
0.38
0.44
0.30
0.63
0.33
0.37
0.19
0.63
0.19
0.41
0.25
0.63
0.26
-0.30
-0.32
-0.16
-0.49
0.03
0.18
-0.13
0.02
-0.57
-0.47
-0.43
-0.25
Washington Park, Indianapolis, Indiana - WPIN
Acetaldehyde
Formaldehyde
56
56
0.68
0.81
0.65
0.80
0.53
0.69
0.59
0.75
-0.50
-0.51
-0.23
-0.16
-0.43
-0.43
to
~ = Sea level pressure was not recorded at the Lansing Municipal Airport
-------
Table 12-7. MRL Risk Screening Assessment Summary for the Indiana Monitoring Sites
Site
INDEM
Method
TO-11A
Pollutant
Formaldehyde
ATSDR
Acute
MRL
(Hg/m3)
50
#of
Exceedances/
#of
Measured
Detections
15/60
ATSDR
Intermediate
MRL
(Hg/m3)
40
Winter
Average
(jig/m3)
14.12
±3.15
Spring
Average
(jig/m3)
34.94
±9.19
Summer
Average
(jig/m3)
64.23
± 14.44
Autumn
Average
(jig/m3)
29.92
±3.23
ATSDR
Chronic
MRL
(Hg/m3)
10
Annual
Average1
(jig/m3)
36.07
±6.34
BOLD = exceedance of the intermediate or chronic MRL
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
to
-------
applicable MRL, the concentration is bolded. Formaldehyde measurements from INDEM
exceeded one or more of the MRL risk values.
Observations about formaldehyde in Table 12-7 include the following:
• Fifteen out of 60 (or one-fourth) measured detections exceeded the ATSDR acute
MRL for formaldehyde (50 |ig/m3).
• Only one other site (SFSD) exceeded the ATSDR acute MRL for formaldehyde;
however, 15 out of the 16 exceedances occurred at INDEM.
• Although INDEM has the highest seasonal averages of formaldehyde for each season
among NATTS and UATMP sites, only the summer average exceeded the ATSDR
intermediate MRL (40 |ig/m3).
• The annual average of formaldehyde for INDEM also exceeded the ATSDR chronic
MRL for formaldehyde (10 |ig/m3). This is the only annual average to exceed a
chronic risk value. The annual average of formaldehyde for INDEM was more than
three times the ATSDR chronic MRL (36.07 ± 6.34 |ig/m3).
For the pollutants that exceeded the acute risk factors, the concentrations were further
examined by developing pollution roses for these pollutants. A pollution rose is a plot of
concentration and wind direction, as described in Section 3.6.1. Figure 12-15 is the
formaldehyde pollution rose for INDEM, where the acute risk factor for formaldehyde was
exceeded.
Observations from the pollution rose include the following:
• Exceedances of the ATSDR acute MRL for formaldehyde occurred with winds
blowing from a variety of directions, although fewer exceedances occurred with
northwesterly winds.
• The highest concentration occurred on a day where wind observations were
designated as "missing" by the NWS.
• On days with available wind observations, the two highest concentrations were
measured on days with a mean wind direction of south and east.
12-28
-------
Figure 12-15. Formaldehyde Pollution Rose for INDEM
200.0
to
to
VO
200.0
200.0 180.0 160.0 140.0 120.0 100.0 80.0 60.0 40.0 20.0 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0
Pollutant Concentration ([jg/m )
-------
12.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Indiana monitoring sites and where
the annual average concentrations could be calculated, risk was further examined by reviewing
cancer and noncancer risk estimates from NATA and calculating cancer and noncancer surrogate
risk approximations (refer to Section 3.6.5 of this report regarding the criteria for an annual
average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 12-8. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the Indiana monitoring sites is as follows:
• The census tract for IDIN is 18097342300, which had a population of 6,536 and
represented approximately 0.8 percent of the Marion County population in 2000.
• The census tract for ININ is 18097358100, which had a population of 3,374 and
represented approximately 0.4 percent of the Marion County population in 2000.
• The census tract for WPIN is 18097350700, which had a population of 2,058 and
represented approximately 0.2 percent of the Marion County population in 2000.
• The census tract for INDEM is 18089010202, which had a population of 1,689 and
represented approximately 0.3 percent of the Lake County population in 2000.
Observations for the Indiana sites from Table 12-8 include the following:
• The pollutants with the highest concentrations according to NATA were
formaldehyde and acetaldehyde for all four Indiana sites.
• The pollutant with the highest cancer risk according to NATA for WPIN and INDEM
was acetaldehyde.
• The pollutant with the highest cancer risk according to NATA for ININ and IDIN was
arsenic. The cancer risk estimate for arsenic for ININ was 208 in-a-million, which
was the highest cancer risk estimate among all counties with UATMP or NATTS
sites from NATA for any given air toxic pollutant.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
arsenic for ININ (1.61).
12-30
-------
Table 12-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Indiana
Pollutant
Cancer
URE
(Hg/rn3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer Risk
(in-a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
South Holt Road, Indianapolis, Indiana (IDIN) - Census Tract ID 18097342300
Acet aldehyde
Arsenic (PM10)
Cadmium (PM10)
Formaldehyde
Manganese (PM10)
Nickel (PM10)
0.000002
0.0043
0.0018
5.5E-09
~
0.00016
0.009
0.00003
0.00002
0.0098
0.00005
0.000065
1.40
0.01
0.01
1.74
O.01
O.01
3.10
4.73
0.05
0.01
~
0.05
0.15
0.03
0.01
0.17
0.08
0.01
2.19 ±0.25
0.01 ±0.01
0.01 ±0.01
3.67 ±0.50
0.01 ±O.01
O.01±O.01
4.38
4.65
0.42
0.02
~
0.21
0.24
0.04
0.01
0.37
0.12
0.02
Gary, Indiana (INDEM) - Census Tract ID 18089010202
Acet aldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.95
1.86
4.32
0.01
0.21
0.19
4.56 ±0.52
36.07 ±6.34
9.12
0.20
0.51
3.68
South Harding Road, Indianapolis, Indiana (EVEN) - Census Tract ID 18097358100
Acet aldehyde
Arsenic (PM10)
Cadmium (PM10)
Formaldehyde
Hexavalent Chromium
Manganese (PM10)
Nickel (PM10)
0.000002
0.0043
0.0018
5.5E-09
0.012
~
0.00016
0.009
0.00003
0.00002
0.0098
0.0001
0.00005
0.000065
1.63
0.05
O.01
1.92
O.01
0.01
0.01
3.60
208.16
0.08
0.01
3.18
~
0.04
0.18
1.61
O.01
0.19
O.01
0.13
0.01
2.02 ±0.23
0.01 ±0.01
O.01±O.01
4.15 ±0.71
NA
0.01 ±O.01
0.01 ±0.01
4.04
4.19
0.50
0.02
NA
~
0.16
0.22
0.03
0.01
0.42
NA
0.12
0.02
Washington Park, Indianapolis, Indiana (WPIN) - Census Tract ID 18097350700
Acet aldehyde
Formaldehyde
0.000002
5.5E-09
0.009
0.0098
1.46
1.47
3.24
0.01
0.16
0.14
2.52 ±0.30
4.06 ±0.58
5.05
0.02
0.28
0.41
to
— = a URE or RfC is not available
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
• The pollutant with the highest 2007 annual average was formaldehyde for every
Indiana site, which were all higher than the modeled concentrations from NATA,
especially for INDEM.
• The pollutants with the highest surrogate cancer risk approximations were
acetaldehyde and arsenic (for ININ and IDIN only).
• Formaldehyde was the only pollutant with a noncancer risk approximation greater
than 1.0 (3.68 for INDEM).
• An annual average and risk approximations were not provided for hexavalent
chromium for ININ because the site did not sample this pollutant for a long enough
duration.
12.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 12-9 and 12-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 12-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer surrogate risk approximations (in-a-million), as calculated from the annual averages.
Table 12-10 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 12.3, ININ sampled for
carbonyls, metals (PMio), and hexavalent chromium; IDIN sampled for carbonyls and metals
(PMio); WPIN and INDEM sampled for carbonyls only. In addition, the cancer and noncancer
surrogate risk approximations are limited to those sites sampling for a long enough period for
annual averages to be calculated.
12-32
-------
Table 12-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Indiana
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
South Holt Road, Indianapolis, Indiana (ID IN) - Marion County
Benzene
Formaldehyde
Acetaldehyde
Dichloromethane
1,3 -Butadiene
1 ,3 -Dichloropropene
Naphthalene
Coke Oven Emissions
Trichloroethylene
£>-Dichlorobenzene
769.55
315.72
130.46
123.11
101.98
62.41
45.44
30.48
21.22
13.79
Coke Oven Emissions
Benzene
Hexavalent Chromium
1,3 -Butadiene
Arsenic, PM
Naphthalene
Cadmium, PM
Acetaldehyde
POM, Group 2
1 ,3 -Dichloropropene
1.89E-02
6.00E-03
3.66E-03
3.06E-03
2.75E-03
1.55E-03
6.48E-04
2.87E-04
2.85E-04
2.50E-04
Arsenic
Acetaldehyde
Cadmium
Nickel
Formaldehyde
4.65
4.38
0.42
0.21
0.02
South Harding Road, Indianapolis, Indiana (ININ) - Marion County
Benzene
Formaldehyde
Acetaldehyde
Dichloromethane
1,3 -Butadiene
1 ,3 -Dichloropropene
Naphthalene
Coke Oven Emissions
Trichloroethylene
/>-Dichlorobenzene
769.55
315.72
130.46
123.11
101.98
62.41
45.44
30.48
21.22
13.79
Coke Oven Emissions
Benzene
Hexavalent Chromium
1,3 -Butadiene
Arsenic, PM
Naphthalene
Cadmium, PM
Acetaldehyde
POM, Group 2
1 ,3 -Dichloropropene
1.89E-02
6.00E-03
3.66E-03
3.06E-03
2.75E-03
1.55E-03
6.48E-04
2.87E-04
2.85E-04
2.50E-04
Arsenic
Acetaldehyde
Cadmium
Nickel
Formaldehyde
4.19
4.04
0.50
0.16
0.02
-------
Table 12-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Indiana (Continued)
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Washington Park, Indianapolis, Indiana (WPIN) - Marion County
Benzene
Formaldehyde
Acetaldehyde
Dichloromethane
1,3 -Butadiene
1 ,3 -Dichloropropene
Naphthalene
Coke Oven Emissions
Trichloroethylene
£>-Dichlorobenzene
769.55
315.72
130.46
123.11
101.98
62.41
45.44
30.48
21.22
13.79
Coke Oven Emissions
Benzene
Hexavalent Chromium
1,3 -Butadiene
Arsenic, PM
Naphthalene
Cadmium, PM
Acetaldehyde
POM, Group 2
1 ,3 -Dichloropropene
1.89E-02
6.00E-03
3.66E-03
3.06E-03
2.75E-03
1.55E-03
6.48E-04
2.87E-04
2.85E-04
2.50E-04
Acetaldehyde 5.05
Formaldehyde 0.02
Gary, Indiana (INDEM) - Lake County
Benzene
Formaldehyde
Acetaldehyde
Coke Oven Emissions
Naphthalene
Dichloromethane
1,3 -Butadiene
1 ,3 -Dichloropropene
£>-Dichlorobenzene
POM, Group 2
409.17
185.18
144.55
104.05
50.39
47.35
40.56
35.15
7.77
6.40
Coke Oven Emissions
Arsenic, PM
Benzene
Hexavalent Chromium
Naphthalene
1,3 -Butadiene
POM, Group 2
Acetaldehyde
Cadmium, PM
Nickel, PM
6.45E-02
4.00E-03
3.19E-03
1.77E-03
1.71E-03
1.22E-03
3.52E-04
3.18E-04
2.67E-04
2.67E-04
Acetaldehyde 9.12
Formaldehyde 0.20
-------
Table 12-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Indiana
to
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
South Holt Road, Indianapolis, Indiana (ID IN) - Marion County
Toluene
Xylenes
Hydrochloric acid
Benzene
Methanol
Hexane
Formaldehyde
Ethylbenzene
Methyl isobutyl ketone
Methyl fer/-butyl ether
2,163.40
1,366.15
1,062.54
769.55
403.44
337.93
315.72
300.19
253.94
157.32
Acrolein
Manganese, PM
Hydrochloric acid
1,3 -Butadiene
Formaldehyde
Benzene
Arsenic, PM
Bromomethane
Cadmium, PM
Nickel, PM
1,036,753.79
112,061.79
53,126.94
50,989.24
32,216.23
25,651.62
21,302.11
18,964.01
17,988.33
16,907.60
Formaldehyde
Acetaldehyde
Manganese
Arsenic
Nickel
Cadmium
0.37
0.24
0.12
0.04
0.02
0.01
South Harding Road, Indianapolis, Indiana (ININ) - Marion County
Toluene
Xylenes
Hydrochloric acid
Benzene
Methanol
Hexane
Formaldehyde
Ethylbenzene
Methyl isobutyl ketone
Methyl ter/-butyl ether
2,163.40
1,366.15
1,062.54
769.55
403.44
337.93
315.72
300.19
253.94
157.32
Acrolein
Manganese, PM
Hydrochloric acid
1,3 -Butadiene
Formaldehyde
Benzene
Arsenic, PM
Bromomethane
Cadmium, PM
Nickel, PM
1,036,753.79
112,061.79
53,126.94
50,989.24
32,216.23
25,651.62
21,302.11
18,964.01
17,988.33
16,907.60
Formaldehyde
Acetaldehyde
Manganese
Arsenic
Nickel
Cadmium
0.42
0.22
0.12
0.03
0.02
0.01
-------
Table 12-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Indiana (Continued)
to
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Washington Park, Indianapolis, Indiana (WPIN) - Marion County
Toluene
Xylenes
Hydrochloric acid
Benzene
Methanol
Hexane
Formaldehyde
Ethylbenzene
Methyl isobutyl ketone
Methyl fer/-butyl ether
2,163.40
1,366.15
1,062.54
769.55
403.44
337.93
315.72
300.19
253.94
157.32
Acrolein
Manganese, PM
Hydrochloric acid
1,3 -Butadiene
Formaldehyde
Benzene
Arsenic, PM
Bromomethane
Cadmium, PM
Nickel, PM
1,036,753.79
112,061.79
53,126.94
50,989.24
32,216.23
25,651.62
21,302.11
18,964.01
17,988.33
16,907.60
Formaldehyde
Acetaldehyde
0.41
0.28
Gary, Indiana (INDEM) - Lake County
Hydrochloric acid
Toluene
Xylenes
Benzene
Methanol
Hexane
Formaldehyde
Acetaldehyde
Ethylbenzene
Hydrofluoric acid
1,133.23
1,007.99
714.90
409.17
243.54
233.90
185.18
144.55
117.17
104.37
Manganese, PM
Acrolein
Hydrochloric acid
Arsenic, PM
Nickel, PM
1,3 -Butadiene
Chlorine
Formaldehyde
Naphthalene
Acetaldehyde
813,671.59
461,981.86
56,661.27
31,017.17
25,633.60
20,279.67
19,571.26
18,895.60
16,797.39
16,061.30
Formaldehyde
Acetaldehyde
3.68
0.51
-------
Observations from Table 12-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in both Marion and Lake County.
• The pollutant with the highest toxicity-weighted emissions (of the pollutants with
cancer UREs) for both counties was coke oven emissions. Benzene and hexavalent
chromium had the second and third highest toxicity-weighted emissions in Marion
County, while arsenic and benzene ranked second and third in Lake County.
• Six of the highest emitted pollutants in Marion and Lake County also had the highest
toxicity-weighted emissions (although the actual pollutants varied in each county).
• Arsenic, which had the fifth highest toxicity-weighted emissions in Marion County,
had the highest surrogate cancer risk approximations for ININ and IDIN.
• Acetaldehyde, which was the third highest emitted pollutant and had the eighth
highest toxicity-weighted emissions in both Lake and Marion Counties, had the
highest surrogate cancer risk approximation for WPIN and INDEM, and the second
highest for ININ and IDIN.
• Although formaldehyde was the second highest emitted pollutant in both Lake and
Marion Counties, it did not appear on the list of highest toxicity-weighted emissions
and its cancer risk approximations for all sites were low.
Observations from Table 12-10 include the following:
• Toluene, xylenes, and hydrochloric acid were the highest emitted pollutants with
noncancer RfCs in both Marion and Lake County, although not necessarily in that
order.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) for both counties were acrolein, manganese, and hydrochloric acid,
although not necessarily in that order.
• Three of the highest emitted pollutants in both counties also had the highest toxicity-
weighted emissions (although the actual pollutants varied in each county).
• The pollutant with the highest noncancer risk approximation was formaldehyde for all
four sites. Formaldehyde also ranked among the pollutants with the highest
emissions and toxicity-weighted emissions.
12-37
-------
12.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Acetaldehyde and formaldehyde were the pollutants of interest common to each
Indiana monitoring site. For the two monitoring sites sampling metals, arsenic and
manganese were also pollutants of interest.
»«» Concentrations and averages of formaldehyde had the highest daily average
concentration for each of the monitoring sites. The daily average concentration for
INDEMwas the highest among all participating monitoring sites.
»«» Concentrations and averages of formaldehyde exceeded the acute, intermediate, and
chronic MRL health benchmarks for INDEM.
12-38
-------
13.0 Site in Kentucky
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Kentucky, and integrates these concentrations
with emissions, meteorological, and risk information.
13.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. Figure 13-1 is a composite
satellite image retrieved from Google™ Maps showing the monitoring site in its rural location.
Figure 13-2 identifies point source emission locations within 10 miles of the site as reported in
the 2002 NEI for point sources. Table 13-1 describes the area surrounding the monitoring site
and provides supplemental geographical information such as land use, location setting, and
locational coordinates.
The HAKY monitoring site is located in southeastern Kentucky, between the towns of
Hazard and Bonnyman, just on the outskirts of the Daniel Boone National Forest. The site is
located on the property of the Perry County Horse Park. Due to the rural nature of the area, a
close-in satellite map is not available. However, Figure 13-1 does show the rolling topography
of the region as well as the major highways near the site. The Hal Rogers Parkway and State
Highways 15 and 80 merge just to the north of the monitoring site. As Figure 13-2 shows,
HAKY is located near a small number of point sources, which are located mainly to the north
and southeast of the monitoring site. A wood furniture manufacturer, a lumber and food
products manufacturer, a waste treatment disposal facility, and a facility utilizing fuel
combustion processes are within a 10-mile radius of HAKY.
Table 13-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Kentucky monitoring site. County-level vehicle registration and population data for Perry
County were obtained from the Kentucky Transportation Cabinet and the U.S. Census Bureau.
Table 13-2 also includes a vehicle registration to county population ratio (vehicles per person).
13-1
-------
Figure 13-1. Hazard, Kentucky (HAKY) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 1 mile
-------
Figure 13-2. NEI Point Sources Located Within 10 Miles of HAKY
County
4
i
Peiry
Legend
-^- HAKVMATTSsite
10 mile radii*
County boundary
Source Category Groyp
-------
Table 13-1. Geographical Information for the Kentucky Monitoring Site
Site
Code
HAKY
AQS Code
21-193-0003
Location
Hazard
County
Perry
Micro- or
Metropolitan
Statistical Area
Not in an MSA
Latitude
and
Longitude
/I 1 'JIQ/l /I
4Z. JZV44,
71 089778
- / 1 .uo^ / / o
Land Use
Residential
Location
Setting
Suburban
Description of the
Immediate Surroundings
The Perry County Horse Park monitoring station was
established in April 2000 and is designated as a
SLAMS site for PM10 and a Special Purpose
Monitoring site for ozone and PM2 5. In October
2001, PM2 5 Speciation sampling was added as part of
the national speciation program. The site is located
on the grounds of the Perry County Horse Park and is
approximately 2.5 miles north/northeast of Hazard.
The monitoring station is an 8' x 10' aluminum clad
shelter with a wooden deck covering the roof. The
closest structure to the site is Perry Central High
School, which is about 600 feet northwest of the site.
The elevation is at 912 feet.
BOLD = EPA-designated NATTS Site
-------
Table 13-2. Population, Motor Vehicle, and Traffic Information for the Kentucky
Monitoring Site
Site
HAKY
2007
Estimated
County
Population
29,213
Number
of
Vehicles
Registered
47,549
Vehicles
per Person
(Registration:
Population)
1.63
Population
Within
10 Miles
31,861
Estimated
10-mile
Vehicle
Ownership
51,859
Annual
Average
Traffic
Data1
21,537
VMT
(thousands)
NA
1 Daily Average Traffic Data reflects 2005 data from the Kentucky Transportation Cabinet
BOLD = EPA-designated NATTS Site
In addition, the population within 10 miles of the site is presented. An estimate of 10-mile
vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 13-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 13-2 presents the daily VMT for each
urban area.
Observations from Table 13-2 include the following:
• The Perry County population was the third lowest compared to all counties with
NATTS or UATMP sites, while HAKY's 10-mile population ranked sixth lowest.
• The Perry County vehicle registration was the sixth lowest compared to all counties
with NATTS or UATMP sites, while its 10-mile estimated ownership was eighth
lowest.
• The rather low population and vehicle ownership compared to other NATTS or
UATMP sites is not surprising given the rural nature of the surrounding area.
• The vehicle per person ratio was the third highest compared to other NATTS or
UATMP sites.
• The traffic volume experienced near HAKY ranked in the middle of the range
compared to other monitoring sites. The traffic estimate used came from the Daniel
Boone Parkway, a major thoroughfare across southeast Kentucky.
• VMT was unavailable for this area.
13-5
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13.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Kentucky on sampling days, as well as over the course of the year.
13.2.1 Climate Summary
The town of Hazard is located in southeast Kentucky, just on the outskirts of Daniel
Boone National Forest. The area experiences all four seasons, and precipitation is fairly evenly
distributed throughout the year (Wildernet, 2007).
13.2.2 Meteorological Conditions in 2007
Hourly meteorological data at the weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Julian Carroll Airport, Jackson, Kentucky (WBAN 03889).
Table 13-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 13-3 is the 95 percent
confidence interval for each parameter. As shown in Table 13-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
13.2.3 Composite Back Trajectories for Sampling Days
Figure 13-3 is a composite back trajectory map for the Kentucky monitoring site for the
days on which samples were collected. Each line represents the 24-hour trajectory along which a
parcel of air traveled toward the monitoring site on a sampling day. Each concentric circle
around the site in Figure 13-3 represents 100 miles.
13-6
-------
Table 13-3. Average Meteorological Conditions near the Kentucky Monitoring Site
Site
HAKY
Closest NWS
Station and
WBAN
Julian Carroll
Airport,
Jackson, KY
03889
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
68.23
±4.74
67.35
±1.91
Average
Temperature
(op)
59.35
±4.29
57.93
±1.81
Average
Dew Point
Temperature
(°F)
44.90
±4.39
43.36
±1.81
Average
Wet Bulb
Temperature
(»F)
51.93
±3.85
50.51
±1.61
Average
Relative
Humidity
(%)
62.44
±3.73
61.96
± 1.47
Average
Sea Level
Pressure
(mb)
1018.03
±1.34
1018.28
±0.54
Average
Scalar Wind
Speed
(kt)
2.76
±0.47
2.78
±0.20
BOLD = EPA-designated NATTS Site
-------
Figure 13-3. Composite Back Trajectory Map for HAKY
UJ
oo
-------
Observations from Figure 13-3 include the following:
• Back trajectories originated from a variety of directions at HAKY. However,
trajectories originated primarily from the south and southwest.
• The 24-hour air shed domain for HAKY was similar in size to other monitoring sites.
The furthest away a trajectory originated was Lake Superior, or greater than 700
miles away. However, 90 percent of trajectories originated within 400 miles of the
monitoring site.
13.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at Julian Carroll Airport near HAKY were
uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce customized
wind roses. A wind rose shows the frequency of wind directions on a 16-point compass, and
uses different shading to represent wind speeds. Figure 13-4 is the wind rose for the Kentucky
monitoring site on days that samples were collected.
Figure 13-4. Wind Rose for HAKY Sampling Days
1 0%
13-9
-------
Observations from Figure 13-4 for HAKY include the following:
• Calm winds were prevalent near HAKY, as calm winds were observed for more than
half of the hourly measurements.
• For winds greater than two knots, southwesterly and westerly winds were observed
most frequently.
• Winds exceeding 11 knots made up only one percent of observations.
13.3 Pollutants of Interest
"Pollutants of interest" were determined for the monitoring site in order to allow analysts
and readers to focus on a risk-based subset of pollutants. The pollutants of interest for the
Kentucky monitoring site were identified using the EPA risk screening process described in
Section 3.2. In brief, each pollutant's measured concentration was compared to its associated
risk screening value. If the daily concentration was greater than the risk screening value, then
the measured concentration "failed the screen." Pollutants of interest are those for which the
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 13-4 presents the pollutants that failed at least one screen for the Kentucky
monitoring site and highlights the site's pollutants of interest (shaded).
Observations from Table 13-4 include the following:
• HAKY sampled for hexavalent chromium only.
• One measured detection of hexavalent chromium failed a screen for HAKY. This
represents a three percent failure rate.
Table 13-4. Comparison of Measured Concentrations and EPA Screening Values for the
Kentucky Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Hazard, Kentucky - HAKY
Hexavalent Chromium
Total
1
1
33
33
3.03
3.03
100.00
100.00
13-10
-------
13.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Kentucky monitoring site. The averages presented are provided for the pollutants of
interest for the site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the site, where applicable.
13.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 13-5, where applicable.
The averages presented in Table 13-5 are shown in ng/m3 for ease of viewing.
Table 13-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Kentucky Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average1
(ng/m3)
Hazard, Kentucky - HAKY
Hexavalent Chromium
33
60
0.018
± 0.006
NR
0.014
± 0.008
0.017
±0.010
0.011
± 0.004
0.012
± 0.004
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for HAKY from Table 13-5 include the following:
• The daily average concentration of hexavalent chromium was somewhat higher than
the annual average (0.018 ± 0.006 ng/m3 vs. 0.012 ± 0.004 ng/m3), which illustrates
the effect of the substitution of 1/2 MDL.
13-11
-------
• Seasonal averages of hexavalent chromium were fairly similar to each other when the
confidence interval is considered. A winter average could not be calculated due to
the low number of detections.
13.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. HAKY has not sampled continuously for five years as part of the
National Monitoring Program; therefore, the trends analysis was not conducted.
13.5 Pearson Correlations
Table 13-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations from Table 13-6 include the following:
• All of the correlations for HAKY were weak.
13.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
13.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Kentucky
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. None of the concentrations
13-12
-------
Table 13-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Kentucky
Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Hazard, Kentucky - HAKY
Hexavalent Chromium
33
-0.09
-0.02
0.06
0.04
0.17
-0.24
0.19
-------
of hexavalent chromium measured at the HAKY monitoring site exceeded any of the MRL risk
values.
13.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Kentucky monitoring site and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 13-7. The
data from NATA are presented for the census tract where the monitoring site is located. The
census tract ID for HAKY is 21193970400, for which the population was 4,359, and represented
15 percent of the 2000 county population. The pollutants of interest for the site are bolded.
Observations for HAKY from Table 13-7 include the following:
• The modeled concentration for hexavalent chromium from NATA was less than 0.01
|ig/m3, as was the annual average.
• Cancer and noncancer risks from hexavalent chromium according to NATA were
relatively low. This was also true of the cancer and noncancer surrogate risk
approximations.
13.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 13-8 and 13-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 13-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 13-9
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
13-14
-------
Table 13-7. Cancer and Noncancer Risk Summary for the Monitoring Site in Kentucky
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Hazard, Kentucky (HAKY) - Census Tract ID 21193970400
Hexavalent Chromium
0.012
0.0001
<0.01
0.02
<0.01
<0.01
±<0.01
0.15
<0.01
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 13-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Kentucky
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Hazard, Kentucky (HAKY) - Perry County
Benzene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
Dichloromethane
1,3 -Butadiene
Naphthalene
POM, Group 2
£>-Dichlorobenzene
Trichloroethylene
38.80
12.01
4.06
3.86
2.40
2.39
1.13
0.79
0.62
0.09
Benzene
1,3 -Butadiene
POM, Group 2
Naphthalene
POM, Group 3
Tetrachloroethylene
POM, Group 5
Hexavalent Chromium
Acetaldehyde
Arsenic, PM
3.03E-04
7.17E-05
4.34E-05
3.83E-05
2.52E-05
2.28E-05
1.74E-05
1.02E-05
8.93E-06
7.89E-06
Hexavalent Chromium 0.15
-------
Table 13-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Kentucky
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Hazard, Kentucky (HAKY) - Perry County
Toluene
Xylenes
Benzene
Methanol
Formaldehyde
Methyl fer/-butyl ether
Ethylbenzene
Hexane
Methyl isobutyl ketone
Styrene
68.56
46.03
38.80
14.77
12.01
11.32
10.42
10.34
5.03
4.49
Acrolein
Benzene
4,4'-Methylenediphenyl
diisocyanate, gas
Formaldehyde
1,3 -Butadiene
Cyanide Compounds, gas
Xylenes
Acetaldehyde
Naphthalene
Toluene
41,819.77
1,293.21
1,255.09
1,225.33
1,194.22
983.33
460.25
450.84
375.62
171.40
Hexavalent Chromium <0.01
-------
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
risk approximations based on each site's annual averages are limited to those pollutants for
which each respective site sampled. As discussed in Section 13.3, HAKY sampled forhexavalent
chromium only. In addition, the cancer and noncancer surrogate risk approximations are limited
to those sites sampling for a long enough period for annual averages to be calculated.
Observations from Table 13-8 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Perry County. The overall emissions for this county were low
compared to other counties with NATTS or UATMP sites.
• Benzene was also the pollutant with the highest toxi city-weighted emissions (of the
pollutants with cancer UREs), followed by 1,3-butadiene and POM group 2.
• Six of the highest emitted pollutants also had the highest toxicity-weighted emissions
for Perry County.
• Hexavalent chromium, which was the only pollutant sampled for at HAKY, had the
eighth highest toxicity-weighted emissions for Perry County. This pollutant did not
appear on the list of highest emitted pollutants.
Observations from Table 13-9 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Perry County. The overall emissions for this county were low compared to
other counties with NATTS or UATMP sites.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, benzene, and gaseous 4,4'-methylenediphenyl
diisocyanate.
• Four of the highest emitted pollutants in Perry County also had the highest toxicity-
weighted emissions.
• Hexavalent chromium did not appear on the list of highest emitted pollutants or the
list of highest toxicity-weighted emissions for pollutants with a noncancer toxi city
factor.
13-18
-------
13.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Hexavalent chromium failed one screen for HAKY.
»«» Hexavalent chromium did not exceed any of the MRL health benchmarks.
13-19
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14.0 Site in Massachusetts
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Massachusetts, and integrates these concentrations
with emissions, meteorological, and risk information.
14.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Massachusetts site is
located in the Boston-Cambridge-Quincy, MA-NH MSA. Figure 14-1 is a composite satellite
image retrieved from Google™ Maps showing the monitoring site in its urban location. Figure
14-2 identifies point source emission locations within 10 miles of the site as reported in the 2002
NEI for point sources. Table 14-1 describes the area surrounding the monitoring site and
provides supplemental geographical information such as land use, location setting, and locational
coordinates.
The BOMA monitoring is located at Dudley Square in Roxbury, southwest of Boston.
The surrounding area is commercial as well as residential, as shown in Figure 14-1. The
monitoring site is approximately one mile south of 1-90 and one mile west of 1-93. The original
purpose for the location of this site was to measure population exposure to a city bus terminal
located across the street from the monitoring site. In recent years, the buses servicing the area
were converted to compressed natural gas (CNG). As Figure 14-2 shows, BOMA is located near
a number of emission sources, which are primarily located to the north and west of the site. The
majority of the emission sources surrounding BOMA employ fuel combustion processes.
Table 14-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Massachusetts monitoring site. County-level vehicle registration and population data for Suffolk
County were obtained from the Massachusetts Registry of Motor Vehicles and the U.S. Census
Bureau. Table 14-2 also includes a vehicle registration to county population ratio (vehicles per
person). In addition, the population within 10 miles of each site is presented. An estimate of
14-1
-------
Figure 14-1. Boston, Massachusetts (BOMA) Monitoring Site
to
'.'«y7~
• e»'' •- f •
•r;"***} .-" 'A
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 14-2. NEI Point Sources Located Within 10 Miles of BOMA
.'
' ..
F F' ff PFi U*
•
NOT*: DIM t» TKJII) d«nM» Mid sc»oct*g> Ih* Wil ttclttMt
may not rifiresenl al
-------
Table 14-1. Geographical Information for the Massachusetts Monitoring Site
Site
Code
BOMA
AQS Code
25-025-0042
Location
Boston
County
Suffolk
]Micro- or
Metropolitan
Statistical Area
Boston-
Cambridge-
Quincy, MA-NH
Latitude
and
Longitude
42.32944,
-71.082778
Land Use
Commercial
Location
Setting
Urban/City
Center
Description of the
Immediate Surroundings
The Boston site is located in a mixed
commercial/residential neighborhood on Harrison
Avenue in Dudley Square. The site is a core urban
background/environmental justice site. A city bus
terminal is located across the street from the monitor.
The buses have been converted to compressed natural
gas (CNG).
BOLD = EPA-designated NATTS Site
-------
Table 14-2. Population, Motor Vehicle, and Traffic Information for the Massachusetts
Monitoring Site
Site
BOMA
2007
Estimated
County
Population
713,049
Number
of
Vehicles
Registered
467,969
Vehicles
per Person
(Registration:
Population)
0.66
Population
Within
10 Miles
1,585,962
Estimated
10 mile Vehicle
Ownership
1,040,856
Annual
Average
Traffic
Data1
23,800
VMT
(thousands)
94,248
1 Daily Average Traffic Data reflects 2005 data from the Mass Highway Department
BOLD = EPA-designated NATTS Site
10-mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 14-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 14-2 presents the daily VMT for each
urban area.
Observations from Table 14-2 include the following:
• The Suffolk County population was in the middle of the range compared to all
counties with NATTS or UATMP sites, while BOMA's 10-mile population ranked
seventh highest.
• The Suffolk County vehicle registration was in the middle of the range compared to
all counties with NATTS or UATMP sites, while its 10-mile estimated ownership
was eighth highest.
• The vehicle per person ratio was the eighth lowest compared to other NATTS or
UATMP sites.
• The traffic volume experienced near BOMA ranked in the middle of the range
compared to other monitoring sites. The traffic estimate used came from Melnea
Cass Boulevard between Washington Street and Harrison Avenue.
• VMT for the Boston area ranked tenth among urban areas with available data.
14.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Massachusetts on sampling days, as well as over the course of the year.
14-5
-------
14.2.1 Climate Summary
Boston's location on the East Coast ensures that the city experiences a fairly active
weather pattern. Most storm systems track across the Northeast, bringing ample precipitation to
the area. The proximity to the Atlantic Ocean helps moderate temperature, both in the summer
and the winter, while at the same time allowing winds to gust higher than they would farther
inland. Winds generally flow from the northwest in the winter and southwest in the summer
(Ruffner and Bair, 1987).
14.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Logan International Airport (WBAN14739).
Table 14-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 14-3 is the 95 percent
confidence interval for each parameter. As shown in Table 14-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
14.2.3 Composite Back Trajectories for Sampling Days
Figure 14-3 is a composite back trajectory map for the Massachusetts monitoring site for
the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the site in Figure 14-3 represents 100 miles.
14-6
-------
Table 14-3. Average Meteorological Conditions near the Massachusetts Monitoring Site
Site
BOMA
Closest NWS
Station and
WBAN
Logan
International
Airport
14739
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
58.16
±4.71
58.80
±1.99
Average
Temperature
(op)
51.15
±4.40
51.57
± 1.85
Average
Dew Point
Temperature
(°F)
38.56
±4.95
38.02
±2.00
Average
Wet Bulb
Temperature
(»F)
45.64
±4.11
45.55
±1.68
Average
Relative
Humidity
(%)
64.89
±3.87
63.11
± 1.69
Average
Sea Level
Pressure
(mb)
1017.17
±1.73
1015.88
±0.80
Average
Scalar Wind
Speed
(kt)
9.30
±074
9.39
±0.35
BOLD = EPA-designated NATTS Site
-------
Figure 14-3. Composite Back Trajectory Map for BOMA
00
-------
Observations from Figure 14-3 include the following:
• Back trajectories originated from a variety of directions at BOMA. However,
trajectories originated less frequently from the southeast and east than other
directions.
• The 24-hour air shed domain for BOMA was comparable in size to other monitoring
sites. The furthest away a trajectory originated was central Quebec, Canada, or nearly
800 miles away. However, most trajectories originated within 600 miles of the
monitoring site.
14.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at Logan International Airport near BOMA
were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce
customized wind roses. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figure 14-4 is the wind rose for
the Massachusetts monitoring site on days that samples were collected.
Figure 14-4. Wind Rose for BOMA Sampling Days
15%
14-9
-------
Observations from Figure 14-4 for BOMA include the following:
• Southwesterly and westerly winds were prevalent near BOMA.
• Calm winds were observed for less than four percent of the hourly wind
measurements.
• Winds exceeding 11 knots made up nearly 30 percent of observations, making this
one of the windier locations.
14.3 Pollutants of Interest
"Pollutants of interest" were determined for the site in order to allow analysts and readers
to focus on a risk-based subset of pollutants. The pollutants of interest for the Massachusetts
monitoring site were identified using the EPA risk screening process described in Section 3.2. In
brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 14-4 presents the pollutants that failed at least one screen for the Massachusetts monitoring
site and highlights the site's pollutants of interest (shaded). BOMA sampled for metals (PMio)
and hexavalent chromium.
Table 14-4. Comparison of Measured Concentrations and EPA Screening Values for the
Massachusetts Monitoring Site
Pollutant
# of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Boston, Massachusetts - BOMA
Arsenic (PM10)
Nickel (PM10)
Manganese (PM10)
Hexavalent Chromium
Total
53
23
7
3
86
59
59
59
44
221
89.83
38.98
11.86
6.82
38.91
61.63
26.74
8.14
3.49
61.63
88.37
96.51
100.00
Observations from Table 14-4 include the following:
• Four pollutants with a total of 221 measured concentrations failed at least one screen
for BOMA.
14-10
-------
• Arsenic, nickel, and manganese were identified as the pollutants of interest for
BOMA.
• Less than 40 percent of measured detections failed screens (of the pollutants that
failed at least one screen) for BOMA.
14.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Massachusetts monitoring site. The averages presented are provided for the pollutants of
interest for the site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the site, where applicable.
14.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 14-5, where applicable.
The concentration averages in Table 14-5 are presented in ng/m3 for ease of viewing.
Observations for BOMA from Table 14-5 include the following:
• The pollutants with the highest daily average concentration by mass were manganese
(3.29 ± 0.34 ng/m3), nickel (2.28 ± 0.35 ng/m3), and arsenic (0.46 ± 0.05 ng/m3). The
annual averages for these pollutants were the same as their respective daily averages.
• As shown in Table 4-10, the daily average concentration of arsenic and manganese
for BOMA was the lowest among sites sampling PMio metals.
• The average concentrations of the pollutants of interest for BOMA did not differ
significantly from season to season.
14-11
-------
Table 14-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Massachusetts Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average1
(ng/m3)
Boston, Massachusetts - BOMA
Arsenic (PM10)
Manganese (PM10)
Nickel (PM10)
59
59
59
59
59
59
0.46
±0.05
3.29
±0.34
2.28
±0.35
0.45
±0.07
2.92
±0.49
3.25
±0.62
0.41
±0.10
3.14
±0.74
2.04
±0.38
0.45
±0.12
3.60
±0.69
1.73
±0.63
0.52
±0.13
3.50
±0.71
2.18
±0.82
0.46
±0.05
3.29
±0.34
2.28
±0.35
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
14.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. BOMA has participated in the UATMP and/or NATTS for at least
five years. Figure 14-5 presents the three-year rolling statistical metrics graphically for arsenic.
The statistical metrics presented for calculating trends include the substitution of zeros for non-
detects.
Observations from Figure 14-5 for arsenic measurements at BOMA include the
following:
• Sampling for metals under the UATMP and/or NATTS at BOMA began in 2003.
• The maximum arsenic concentration shown was measured during the 2003-2005 time
frame. The maximum concentrations measured in subsequent time periods were
nearly half the maximum concentration from the 2003-2005 time frame.
• The rolling average concentrations have a decreasing trend over the time periods
shown.
• The rolling averages and the median values became more similar over the periods.
The increasing "closeness" of these metrics indicates decreasing variability in the
central tendency.
• All arsenic concentrations reported to AQS over the five years of sampling were
measured detections.
14-12
-------
Figure 14-5. Three-Year Rolling Statistical Metrics for Arsenic (PMio) Concentrations Measured at BOMA
5.00
4.f
4.00
3.50
3.00
M
I 2.f
e
01
I 2.00
1.00
0.00
2003-2005
2004-2006
Three- Year Period
2005-2007
• 1 st Quartile — Minimum Median — Maximum O Average • 3rd Quartile
-------
14.5 Pearson Correlations
Table 14-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for BOMA from Table 14-6 include the following:
• The pollutants of interest exhibited weak correlations with the meteorological
parameters.
14.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
14.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the
Massachusetts monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where
available. As described in Section 3.3, acute risk results from exposures of 1 to 14 days;
intermediate risk results from exposures of 15 to 364 days; and chronic risk results from
exposures of one year or greater. The preprocessed daily measurements of the pollutants that
failed at least one screen were compared to the acute MRL; the seasonal averages were
compared to the intermediate MRL; and the annual averages were compared to the chronic
MRL. None of the concentrations measured at the BOMA site exceeded any of the MRL risk
values.
14.6.2 Cancer and Noncancer Risk Approximations
For the pollutants that failed at least one screen at the Massachusetts monitoring site and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
14-14
-------
Table 14-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
Massachusetts Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Boston, Massachusetts - BOMA
Arsenic (PM10)
Manganese (PM10)
Nickel (PM10)
59
59
59
0.19
0.25
-0.41
0.12
0.22
-0.41
0.11
0.11
-0.33
0.11
0.17
-0.38
0.04
-0.24
0.07
0.07
0.10
0.30
-0.27
-0.38
-0.20
-------
Concentration and risk estimates from NAT A, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 14-7. The
data from NATA are presented for the census tract where the monitoring site is located. BOMA
is located in census tract ID 25025080400, for which the population was 723, and represented
0.1 percent of the county population in 2000. The pollutants of interest are bolded.
Observations for BOMA from Table 14-7 include the following:
• According to NATA, the concentrations of the pollutants that failed at least one
screen for BOMA were less than 0.01 |ig/m3.
• Cancer and noncancer risk attributable to the pollutants that failed at least one screen
for BOMA were low, according to NATA.
• The annual averages of the pollutants that failed at least one screen for BOMA were
also less than 0.01 |ig/m3.
• Cancer risk approximations based on the annual averages for arsenic and nickel were
an order of magnitude higher than the NATA cancer risk estimates.
• Similar to the NATA results, noncancer risk approximations based on the annual
averages were low.
14.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 14-8 and 14-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 14-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer surrogate risk approximations (in-a-million), as calculated from the annual averages.
Table 14-9 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
14-16
-------
Table 14-7. Cancer and Noncancer Risk Summary for the Monitoring Site in Massachusetts
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Boston, Massachusetts (BOMA) - Census Tract ID 25025080400
Arsenic (PM10)
Hexavalent Chromium
Manganese (PM10)
Nickel (PM10)
0.0043
0.012
0.00016
0.00003
0.0001
0.00005
0.000065
0.01
<0.01
0.01
O.01
0.28
0.53
0.09
0.01
O.01
0.01
0.01
O.01
±0.01
O.01
±0.01
0.01
±0.01
O.01
±0.01
1.97
0.29
0.37
0.02
O.01
0.07
0.04
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
-------
Table 14-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Massachusetts
oo
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Boston, Massachusetts (BOMA) - Suffolk County
Benzene
Formaldehyde
Acetaldehyde
Dichloromethane
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
POM, Group 1
Trichloroethylene
POM, Group 2
232.26
176.23
68.00
57.42
31.39
24.90
11.23
7.90
6.93
4.94
Benzene
1,3 -Butadiene
POM, Group 1
Naphthalene
Hexavalent Chromium
POM, Group 2
POM, Group 5
Arsenic, PM
Acetaldehyde
Tetrachloroethylene
1.81E-03
9.42E-04
4.34E-04
3.82E-04
2.81E-04
2.72E-04
1.82E-04
1.59E-04
1.50E-04
1.47E-04
Arsenic
Nickel
Hexavalent Chromium
1.97
0.37
0.29
-------
Table 14-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Massachusetts
VO
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Boston, Massachusetts (BOMA) - Suffolk County
Toluene
Methyl tert-butyl ether
Xylenes
Methanol
Benzene
Formaldehyde
Methyl isobutyl ketone
Ethylene glycol
Ethylbenzene
Hexane
636.32
504.90
483.17
401.01
232.26
176.23
146.05
123.01
85.88
81.15
Acrolein
Formaldehyde
1,3 -Butadiene
Nickel, PM
Cyanide Compounds, gas
Benzene
Acetaldehyde
Xylenes
Naphthalene
Glycol ethers, gas
507,083.33
17,982.94
15,692.84
13,832.64
8,716.67
7,741.84
7,555.62
4,831.74
3,744.26
2,620.25
Manganese
Nickel
Arsenic
Hexavalent Chromium
0.07
0.04
0.02
0.00
-------
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
risk approximations based on each site's annual averages are limited to those pollutants for
which each respective site sampled. As discussed in Section 14.3, BOMA sampled for metals
and hexavalent chromium. In addition, the cancer and noncancer risk approximations are limited
to those sites sampling for a long enough period for an annual average to be calculated.
Observations from Table 14-8 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Suffolk County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) were benzene, 1,3-butadiene, and POM Group 1.
• Seven of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Arsenic was the pollutant with the highest cancer surrogate risk approximation for
BOMA. This pollutant also appeared on the list of highest toxi city-weighted
emissions. Hexavalent chromium, which had the third highest cancer surrogate risk
approximation, also appeared on the list of highest toxicity-weighted emissions.
Observations from Table 14-9 include the following:
• Toluene, methyl fert-butyl ether, and xylenes were the highest emitted pollutants with
noncancer RfCs in Suffolk County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, formaldehyde, and 1,3-butadiene.
• Three of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Nickel, which had the second highest noncancer risk approximation, also had the
fourth highest toxi city-weighted emissions. The remaining pollutants of interest did
not appear on the list of highest toxi city-weighted emissions.
14.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest for BOMA were arsenic, manganese, and nickel.
14-20
-------
»«» Manganese had the highest daily average concentration among the pollutants of
interest for BOMA.
»«» There were no exceedances of the MRL health benchmarks at BOMA.
14-21
-------
15.0 Sites in Michigan
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS and UATMP sites in Michigan, and integrates these
concentrations with emissions, meteorological, and risk information.
15.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. The DEMI monitoring site
is located in the Detroit-Warren-Livonia, MI MSA. ITCMI is located in Sault Sainte Marie on
the Upper Peninsula. Figures 15-1 and 15-2 are composite satellite images retrieved from
Google™ Maps showing the monitoring sites in their urban locations. Figures
15-3 and 15-4 identify point source emission locations within 10 miles of each site as reported in
the 2002 NEI for point sources. Table 15-1 describes the area surrounding each monitoring site
and provides supplemental geographical information such as land use, location setting, and
locational coordinates.
DEMI is located at Paul Costea Park in Dearborn, just southwest of Detroit. The
surrounding area is both suburban and industrial in nature. Figure 15-1 shows that a freight yard
is located to the west of the site and a residential neighborhood is located to the east. Industrial
sources such as an auto and steel manufacturing facility are also located in the vicinity. Heavily
traveled roadways surround the monitoring site, as the site lies between 1-75 and 1-94. As
Figure 15-3 shows, a number of point sources surround DEMI, several of which are located just
south of the site. Many of the point sources within 10 miles of DEMI are engaged in processes
involving fuel combustion or waste treatment and disposal processes. Five point sources are
shown in very close proximity of DEMI, including emission sources involved in iron and steel
manufacturing, ferrous metal processing, and the use of utility boilers.
ITCMI is located on the property of Lake Superior State University in Sault Sainte Marie
and is operated by the Intertribal Council of Michigan. Monitoring was initiated at this location
because tribal members were concerned about industrial emission sources across the St. Mary's
15-1
-------
Figure 15-1. Dearborn, Michigan (DEMI) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 15-2. Sault Sainte Marie, Michigan (ITCMI) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 15-3. NEI Point Sources Located Within 10 Miles of DEMI
Not*. Out lo tmil j d«n«l» *nd wBwaMn m» «
nay not rifiresenl al Incilnies AIWWI th« MVB ol merest
Legend
DEMI WATTS site
10 mile radius | ~J County boundary
Source Category Group (No. of Facilities)
* Automotive Repair; Services. & Peking (1)
c Chemicais & Allied Products Facility (2)
2 Electrical & Electronic Equipment Facility (1)
Fabricated M«tal Products Facitrty (5)
Ferrous Metals Processing Incfcjstrial Facility (1)
Fuel Combustion Industrial Facility (33)
incineration Industrial Facility (5)
Integrated Iron S. Steel Manufacturing Facility (2)
Uqmds Dislntxjton lixlustnal Facility (8)
Mineral Roducts Recessing Industrial Facility (6)
Miscellaneous Processes Industrial Facility (5)
Non-ferrate Metete Frocessing Industnal Facflity (1)
2 Nonrnetallrc Minerals. Except Fuels (2)
P PelroleurrVNal Gas Prod. & Retiring Industrial Facility (2)
> Ftiarmaceutical Proikietion Processes Industrial Facility (1)
V Polymers & Resins Production Industrial Facility (1)
* Reduction of Organic ChemKals ln(*jstrial Facility (2)
v Rubber & Miscellaneous Plastic Products Facility (11
u Stone. Clay. Glass. & Concrete Roducts (2)
s Surface Coating Processes Industrial Facility (3)
T Transportation Eqwpment (1)
8 Utility Balers (7J
• Waste Treatment & Disfwsal Induslrial Facility (14)
f WhotesaleTrada(l)
15-4
-------
Figure 15-4. NEI Point Sources Located Within 10 Miles of ITCMI
.
fcfjotiv* M'lifovr
)tot« Out l» rtslnj
-------
Table 15-1. Geographical Information for the Michigan Monitoring Sites
Site
Code
DEMI
ITCMI
AQS Code
26-163-0033
26-033-0901
Location
Dearborn
Sault Ste.
Marie
County
Wayne
Chippewa
Micro- or
Metropolitan
Statistical Area
Detroit-Warren-
Livonia, MI
Sault Ste. Marie,
MI
Latitude
and
Longitude
42.30754,
-83.14961
46.493611,
-84.364167
Land Use
Industrial
Residential
Location
Setting
Suburban
Rural
Description of the
Immediate Surroundings
The Dearborn, MI site is located in a residential
neighborhood with industrial impacts. Auto and
steel manufacturing plants, in addition to other
sources, are located in close proximity to the
monitoring site. Previous violations of the PM10
standard have also occurred at this site. The site lies
between 1-75 and 1-94. This site is expected to show
some of the highest levels of air toxics in the Detroit
Pilot program area. Continuous EC/OC,
aethalometry and the suite of NATTS analytes are
monitored for at this location, as are TSP trace
metals, co-located PM10 trace metals, and a l-in-6
day PM2 5 speciation site. This site is often used for
special studies.
Tribal members had issued complaints arising from
the smell and clouds being produced from a steel
plant and paper mill located on the other side of the
Saint Mary's River. The monitoring site is located on
Lake Superior State University campus, which is a
residential area. This site includes a sequential PM2 5
filter based FRM monitors, a PM2 5 TEOM monitor,
an AVOCS monitor, a PAH monitor, and a
meteorological station.
BOLD = EPA-designated NATTS Site
-------
River in Ontario, Canada. Figure 15-2 shows that ITCMI is east of 1-75 and north of
Business-75. The area surrounding ITCMI is primarily residential. As Figure 15-4 shows, all of
the point sources in the U.S. within 10 miles of ITCMI are involved in waste treatment and
disposal. Any possible emissions sources located in Canada are not provided in Figure 15-4.
Table 15-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Michigan monitoring sites. County-level vehicle registration and population data for Wayne and
Chippewa Counties were obtained from the Michigan Department of State and the U.S. Census
Bureau. Table 15-2 also includes a vehicle registration to county population ratio (vehicles per
person). In addition, the population within 10 miles of each site is presented. An estimate of 10-
mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 15-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 15-2 presents the daily VMT for each
urban area (where applicable).
Table 15-2. Population, Motor Vehicle, and Traffic Information for the Michigan
Monitoring Sites
Site
DEMI
ITCMI
2007
Estimated
County
Population
1,985,101
38,922
Number
of
Vehicles
Registered
1,400,461
36,768
Vehicles
per Person
(Registration:
Population)
0.71
0.94
Population
Within
10 Miles
1,138,740
21,803
Estimated
10 mile Vehicle
Ownership
803,365
20,596
Annual
Average
Traffic
Data1
20,900
5,200
VMT
(thousands)
104,126
NA
Daily Average Traffic Data reflects 2006 data from the Michigan DOT
BOLD = EPA-designated NATTS Site
Observations from Table 15-2 include the following:
• Wayne County had the sixth highest county population and eighth highest county-
level vehicle registration compared to all counties with NATTS or UATMP sites.
Conversely, Chippewa County had the fourth lowest county population and county-
level vehicle registration compared to all counties with NATTS or UATMP sites.
This difference among the two Michigan sites is also reflected in the population and
ownership estimates within 10 miles.
15-7
-------
• The vehicle per person ratio for ITCMI was nearly one vehicle per person, which is
higher than the vehicle per person ratio for DEMI.
• DEMI experienced a higher average daily traffic volume than ITCMI, although both
were relatively low compared to other program sites. Traffic for ITCMI was obtained
from 1-75 near the intersection of West Spruce Street and Portage Avenue; traffic for
DEMI was obtained from 1-94, near Michigan Avenue and Loyno Street.
• The Detroit area VMT ranked seventh among urban areas with UATMP or NATTS
sites. VMT for the Sault Sainte Marie area was not available.
15.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Michigan on sampling days, as well as over the course of the year.
15.2.1 Climate Summary
The Detroit area is located in the Great Lakes region, where storm systems frequently
track across the region. Winters tend to be cold and wet, while summers are generally mild. The
urbanization of the area along with Lake St. Clair to the east are two major influences on the
city's weather. The lake tends to keep the Detroit area warmer in the winter and cooler in the
summer than more inland areas. The urban heat island keeps the city warmer than outlying
areas. Winds are often breezy and generally flow from the southwest on average (Ruffner and
Bair, 1987).
Sault Sainte Marie is located on the northeast edge of Michigan's Upper Peninsula.
While this area also experiences an active weather pattern, its climate is somewhat tempered by
the surrounding waters of Lakes Superior and Huron, as the city resides on the channel between
the two lakes. This location experiences ample precipitation, especially during lake-effect snow
events (Ruffner and Bair, 1987).
15.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
15-8
-------
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at Detroit-Metropolitan Airport (near DEMI) and Sault Ste.
Marie Municipal Airport (near ITCMI), WBAN 94847 and 14847, respectively.
Table 15-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 15-3 is the 95 percent
confidence interval for each parameter. As shown in Table 15-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
15.2.3 Composite Back Trajectories for Sampling Days
Figures 15-5 and 15-6 are composite back trajectory maps for the Michigan monitoring
sites for the days on which samples were collected. Each line represents the 24-hour trajectory
along which a parcel of air traveled toward the monitoring site on a sampling day. Each
concentric circle around the sites in Figures 15-5 and 15-6 represents 100 miles.
Observations from Figure 15-5 for DEMI include the following:
• Back trajectories originated from a variety of directions at the DEMI site, although
there were fewer trajectories from the southeast. The predominant direction of
trajectory origin was from the south and northwest.
• The 24-hour air shed domain for DEMI was comparable to other monitoring sites.
The furthest away a trajectory originated was northern Alabama, or less than 700
miles away. However, most trajectories originated within 500 miles of the site.
Observations from Figure 15-6 for ITCMI include the following:
• Back trajectories originated from a variety of directions at the ITCMI site, although
there were fewer trajectories from the northeast and southeast. The predominant
direction of trajectory origin was from the northwest. A secondary cluster of
trajectories originated from the southwest.
15-9
-------
Table 15-3. Average Meteorological Conditions near the Michigan Monitoring Sites
Site
DEMI
ITCMI
Closest NWS
Station and
WBAN
Detroit/
Metropolitan
Airport
94847
Sault Ste.
Marie
Municipal
Airport
14847
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
60.47
±5.35
59.20
±2.22
52.30
±6.11
50.97
±2.27
Average
Temperature
(op)
52.35
±4.93
51.19
±2.04
44.01
±5.48
42.78
±2.07
Average
Dew Point
Temperature
(°F)
40.11
±4.47
39.20
±1.88
34.74
±5.04
33.93
±1.97
Average
Wet Bulb
Temperature
(»F)
46.27
±4.32
45.34
±1.80
39.72
±4.92
38.83
±1.89
Average
Relative
Humidity
(%)
66.11
±3.03
66.42
± 1.23
73.08
±3.30
73.78
± 1.25
Average
Sea Level
Pressure
(mb)
1017.08
±1.60
1017.35
±0.67
1015.55
±1.71
1015.35
±0.77
Average
Scalar Wind
Speed
(kt)
7.10
±0.78
7.43
±0.36
6.62
±0.74
6.32
±0.26
BOLD = EPA-designated NATTS Site
-------
Figure 15-5. Composite Back Trajectory Map for DEMI
0 50 100 200 300
-------
Figure 15-6. Composite Back Trajectory Map for ITCMI
X
S
0 50 100 200 300 -400
Mites
-------
• The 24-hour air shed domain for ITCMI was larger than DEMI and many other
monitoring sites. The furthest away a trajectory originated was north-central
Montana, or nearly 1,000 miles away. However, nearly 90 percent of trajectories
originated within 600 miles of the site.
15.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations at the Detroit-Metropolitan (for DEMI) and
Sault Ste. Marie International (for ITCMI) Airports were uploaded into a wind rose software
program, WRPLOT (Lakes, 2006) to produce customized wind roses. A wind rose shows the
frequency of wind directions on a 16-point compass, and uses different shading to represent wind
speeds. Figures 15-7 and 15-8 are the wind roses for the Michigan monitoring sites on days that
samples were collected.
Observations from Figure 15-7 for DEMI include the following:
• Winds from a variety of directions were observed near DEMI, although southeasterly
winds were observed less frequently than winds from other directions.
• Calm winds were observed for approximately 12 percent of the hourly measurements.
• Winds exceeding 11 knots made up approximately 17.5 percent of observations. The
strongest winds often originated from the south, southwest, and west.
Observations from Figure 15-8 for ITCMI include the following:
• Winds from a variety of directions were observed near ITCMI, although easterly and
northwesterly winds were observed more frequently than winds from other directions.
• Calm winds were observed for approximately 14 percent of the hourly measurements.
• Winds exceeding 11 knots made up approximately 16 percent of observations. The
strongest winds often originated from the southwest and northwest.
15-13
-------
Figure 15-7. Wind Rose for DEMI Sampling Days
NORTH"---.
WES
SOUTH ,-'
EAST
WIND SPEED
(Knots)
CH = 22
• 17 - 21
• 11 - 17
EH 1-7
^| 2- 4
Calms: 12.13%
Figure 15-8. Wind Rose for ITCMI Sampling Days
15-14
-------
15.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Michigan
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 15-4 presents the pollutants that failed at least one screen for each Michigan monitoring
site and highlights each site's pollutants of interest (shaded). DEMI sampled for VOC,
carbonyls, and hexavalent chromium; ITCMI sampled for SVOC only.
Table 15-4. Comparison of Measured Concentrations and EPA Screening Values for the
Michigan Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Dearborn, Michigan - DEMI
Benzene
Carbon Tetrachloride
Acrolein
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Tetrachloroethylene
£>-Dichlorobenzene
Hexavalent Chromium
Chloromethylbenzene
Acrylonitrile
Total
59
59
59
58
58
55
41
21
10
3
2
425
59
59
59
58
58
57
59
55
60
4
3
531
100.00
100.00
100.00
100.00
100.00
96.49
69.49
38.18
16.67
75.00
66.67
80.04
13.88
13.88
13.88
13.65
13.65
12.94
9.65
4.94
2.35
0.71
0.47
13.88
27.76
41.65
55.29
68.94
81.88
91.53
96.47
98.82
99.53
100.00
Sault Ste. Marie, Michigan - ITCMI
Naphthalene
Total
23
23
55
55
41.82
41.82
100.00
100.00
15-15
-------
Observations from Table 15-4 include the following:
• Eleven pollutants with a total of 425 measured concentrations failed at least one
screen for DEMI.
• Eight pollutants contributed to 95 percent of all failed screens for DEMI:
acetaldehyde, acrolein, benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde,
/>-dichlorobenzene, and tetrachloroethylene.
• Five of the eight pollutants of interest failed 100 percent of the screens for DEMI.
• Of the pollutants with at least one failed screen, 80 percent of measurements failed
screens for DEMI.
• Of the SVOC measured at ITCMI, only naphthalene failed screens. Less than half of
the measured detections of naphthalene exceeded the screening value.
15.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Michigan monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical parameters are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
15.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 15-5, where applicable.
15-16
-------
Table 15-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Michigan Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Hg/m3)
Winter
Average
(Hg/m3)
Spring
Average
(Hg/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Hg/m3)
Annual
Average1
(Hg/m3)
Dearborn, Michigan - DEMI
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
58
59
59
57
59
55
58
59
58
59
59
59
59
59
58
59
5.44
±0.89
0.52
±0.12
1.06
±0.18
0.10
±0.02
0.63
±0.03
0.13
±0.04
5.76
±0.71
0.30
±0.07
2.23
±0.59
0.32
±0.08
0.87
±0.25
0.11
±0.04
0.57
±0.06
0.07
±0.02
2.67
±0.67
0.20
±0.04
4.56
±1.36
0.69
±0.42
0.81
±0.19
0.08
±0.02
0.64
±0.04
0.07
±0.02
5.45
±1.30
0.23
±0.07
8.35
±1.73
0.52
±0.09
1.17
±0.24
0.08
±0.02
0.66
±0.06
0.22
±0.13
7.43
±1.14
0.46
±0.21
6.18
±1.49
0.53
±0.09
1.41
±0.52
0.13
±0.06
0.65
±0.04
0.16
±0.09
6.91
±1.01
0.34
±0.11
5.44
±0.89
0.52
±0.12
1.06
±0.18
0.10
±0.02
0.63
±0.03
0.13
±0.04
5.76
±0.71
0.30
±0.07
Sault Ste. Marie, Michigan - ITCMI
Naphthalene
55
55
0.03
±0.01
0.02
±0.02
0.01
±0.01
0.04
±0.01
0.03
±0.01
0.03
±0.01
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for DEMI from Table 15-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (5.76 ± 0.71 |ig/m3), acetaldehyde (5.44 ± 0.89 |ig/m3), and benzene
(1.06 ±0.18 |ig/m3).
• As shown in Table 4-9, of the program-level pollutants of interest, DEMI had the
second highest daily average concentration of formaldehyde and third highest daily
average concentration of acetaldehyde.
• Concentrations of both formaldehyde and acetaldehyde were higher during the
warmer months and lower during the cooler months.
• The annual average concentrations for DEMFs pollutants of interest were the same as
the daily averages.
15-17
-------
Observations for ITCMI from Table 15-5 include the following:
• The averages of naphthalene were relatively similar to each other.
15.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. DEMI has sampled VOC and carbonyls under the UATMP and/or
NATTS since 2003. Figures 15-9 through 15-11 present the three-year rolling statistical metrics
graphically for benzene, 1,3-butadiene, and formaldehyde for DEMI. The statistical metrics
presented for calculating trends include the substitution of zeros for non-detects.
Observations from Figure 15-9 for benzene measurements at DEMI include the
following:
• The maximum benzene concentration shown was measured in 2004, and appears in
Figure 15-9 for both the 2003-2005 and 2004-2006 time frames.
• The median and rolling average concentrations have a decreasing trend over the time
periods shown.
• All benzene concentrations reported to AQS over the five years of sampling were
measured detections.
Observations from Figure 15-10 for 1,3-butadiene measurements at DEMI include the
following:
• The minimum and first quartile for 1,3-butadiene were both zero for the 2003-2005
and 2004-2006 time frames. This is due to the low detection rate of this pollutant at
the onset of sampling. As the MDL for 1,3-butadiene improved (i.e, decreased), the
detection rate for this pollutant increased. This pollutant was detected in 52 percent
of samples during the 2003-2005 time frame; 66 percent of samples during 2004-
2006; and 85 percent of samples during 2006-2007.
• The median and average rolling concentrations shown for all time frames changed
little across each period, indicating little variability in the central tendency.
15-18
-------
Figure 15-9. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at DEMI
2.50 -r
2.00
.o
o.
o.
=
o
1.50
1.00
0.50
2003-2005
2004-2006
Three-Year Period
2005-2007
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 15-10. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at DEMI
n zis
n 40
n "?^
> n "?n
_Q U.JU
&
s
o
1 °'25
"S
0)
CJ
rr! o n 90
to
o
n i ^
n in
n ns
n nn
_ I
2003-2005 2004-2006 2005-2007
Three-Year Period
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 15-11. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at DEMI
o-c nn
9n nn
^-N
.0
a.
o.
o
O
3 i <; nn
Concentra
3 C
3 C
3 C
s nn
n nn
•
1
J
• •
> 1 <
, ;; <
..«-,.«-,.
•
•
• •
> t H
>— -^ ,
.
•
>
2003-2005
2004-2006
Three-Year Period
2005-2007
IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Observations from Figure 15-11 for formaldehyde measurements at DEMI include the
following:
• The maximum formaldehyde concentration shown was measured in 2005, and
appears for all the time frames shown. The five highest measurements of
formaldehyde were all measured in 2005.
• A decrease in the rolling average and median concentration is shown in Figure 15-11.
However, the calculation of confidence intervals indicates that the decrease is not
significant.
• The rolling median and average concentrations were fairly similar for each period,
indicating rather low variabilities in central tendency since sampling began in 2003.
• All formaldehyde concentrations reported to AQS over the five years of sampling
were measured detections.
15.5 Pearson Correlations
Table 15-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for DEMI from Table 15-6 include the following:
• Formaldehyde and acetaldehyde exhibited strong positive correlations with the
temperature and moisture parameters (except relative humidity). This indicates that
concentrations of these pollutants tend to increase as temperature and moisture
content increase.
• While the majority of the correlations with the temperature and moisture parameters
were low, most of them were positive, indicating that as the temperature and moisture
content increase, concentrations of the pollutants of interest may proportionally
increase at DEMI.
• The correlations with scalar wind speed were all negative, most of which were
moderate to strong, indicating that as wind speed decreases, concentrations of the
pollutants of interest may increase at DEMI.
15-22
-------
Table 15-6. Pearson Correlations Between Selected Meteorological Parameters and Pollutants of Interest for the Michigan
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Dearborn, Michigan - DEMI
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
58
59
59
57
59
55
58
59
0.77
0.27
0.21
-0.07
0.29
0.32
0.78
0.38
0.76
0.26
0.19
-0.09
0.31
0.31
0.77
0.38
0.75
0.22
0.23
-0.02
0.26
0.32
0.75
0.42
0.76
0.25
0.21
-0.06
0.29
0.31
0.77
0.40
-0.15
-0.17
0.11
0.26
-0.18
-0.02
-0.17
0.06
-0.02
-0.11
0.15
0.19
0.04
0.06
-0.08
-0.02
-0.61
-0.05
-0.58
-0.54
-0.29
-0.34
-0.49
-0.43
Sault Ste. Marie, Michigan - ITCMI
Naphthalene
55
0.40
0.37
0.36
0.36
-0.07
0.15
-0.47
to
-------
Observations for ITCMI from Table 15-6 include the following:
• Similar to DEMI, correlations with the temperature and moisture parameters were
positive (except relative humidity), indicating that as the temperature and moisture
content increase, concentrations of naphthalene may proportionally increase.
• The correlation between naphthalene and scalar wind speed was negative. This is
similar to the trends exhibited by the pollutants of interest for DEMI.
15.6 Additional Risk Screening Evaluations
The following risk screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
15.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Michigan
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 15-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 15-7 include the following:
• None of the preprocessed daily measurements of acrolein at DEMI exceeded the
acute MRL.
• All four seasonal averages of acrolein exceeded the intermediate MRL.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
15-24
-------
Table 15-7. MRL Risk Screening Assessment Summary for the Michigan Monitoring Sites
Site
DEMI
Method
TO-15
Pollutant
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
#of
Exceedances/
#of
Measured
Detections
0/59
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
Winter
Average
(Ug/m3)
0.32
±0.08
Spring
Average
(Ug/m3)
0.69
±0.42
Summer
Average
(Ug/m3)
0.52
±0.09
Autumn
Average
(Ug/m3)
0.53
±0.09
ATSDR
Chronic
MRL
(Ug/m3)
-
Annual
Average1
(Ug/m3)
0.52
±0.12
~ = an MRL risk factor is not available
BOLD = EPA-designated NATTS Site
BOLD = exceedance of the intermediate or chronic MRL
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
-------
15.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Michigan monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 15-8. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the Michigan sites is as follows:
• The census tract for DEMI is 26163573500, which had a population of 5,214 and
represented approximately 0.3 percent of the Wayne County population in 2000.
• The census tract for ITCMI is 26033970300, which had a population of 3,744, and
represented approximately 10 percent of the county population in 2000.
Observations for DEMI from Table 15-8 include the following:
• The pollutants with the highest concentrations according to NATA were benzene,
acetaldehyde, and formaldehyde.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadidne, and acetaldehyde.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (9.51).
• The pollutants with the highest 2007 annual average concentrations were
formaldehyde, acetaldehyde, and benzene, which were all within an order of
magnitude of the modeled concentrations from NATA.
• The pollutants with the highest surrogate cancer risk approximations were
acetaldehyde, carbon tetrachloride, and benzene.
• Acrolein was the only pollutant with a noncancer risk approximation greater than 1.0
(26.21).
15-26
-------
Table 15-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Michigan
Pollutant
Cancer
URE
(Hg/rn3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Dearborn, Michigan (DEMI) - Census Tract ID 26163573500
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
Chloromethylbenzene
p-Dichlorobenzene
Formaldehyde
Hexavalent Chromium
Tetrachloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000049
0.000011
5.5E-09
0.012
0.000005
0.009
0.00002
0.002
0.03
0.002
0.04
~
0.8
0.0098
0.0001
0.27
2.59
0.19
0.01
3.79
0.33
0.21
O.01
0.08
2.58
0.01
0.36
5.71
—
0.25
29.55
10.05
3.14
O.01
0.92
0.01
1.65
2.16
0.28
9.51
0.01
0.12
0.16
0.01
~
O.01
0.26
0.01
0.01
5.44 ±0.89
0.52 ±0.12
0.03 ±0.01
1.06 ±0.18
0.10 ±0.02
0.63 ± 0.03
0.03 ±O.01
0.13 ±0.04
5.76 ±0.71
0.01 ±0.01
0.30 ±0.07
10.88
—
1.90
7.44
3.03
9.50
1.37
1.39
0.03
0.50
1.52
0.60
26.21
0.01
0.04
0.05
0.02
~
O.01
0.59
0.01
0.01
Sault Sainte Marie, Michigan (ITCMI) - Census Tract ID 26033970300
Naphthalene
0.000034
0.003
0.02
0.64
0.01
0.03 ±0.01
1.01
0.01
to
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Observations for ITCMI from Table 15-8 include the following:
• Naphthalene was the only pollutant to fail screens for ITCMI. The modeled
concentration from NATA and the annual average were similar.
• The surrogate cancer risk approximation for naphthalene was greater than 1-in-a-
million, the threshold value of concern, while the cancer risk estimate from NATA
was just slightly less (0.64).
• The noncancer risk estimate from NATA and the surrogate noncancer risk
approximation for naphthalene were both 0.01.
15.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 15-9 and 15-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 15-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
surrogate cancer risk approximations (in-a-million), as calculated from the annual averages.
Table 15-10 presents similar information, but identifies the 10 pollutants with the highest
surrogate noncancer risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
risk approximations based on each site's annual averages are limited to those pollutants for
which each respective site sampled. As discussed in Section 15.3, DEMI sampled for VOC,
carbonyls, and hexavalent chromium, while ITCMI sampled for SVOC only. In addition, the
cancer and noncancer risk approximations are limited to those sites sampling for a long enough
period for annual averages to be calculated.
15-28
-------
Table 15-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Michigan
to
VO
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations
Based on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Dearborn, Michigan (DEMI) - Wayne County
Benzene
Formaldehyde
Tetrachloroethylene
Dichloromethane
Acetaldehyde
1,3 -Butadiene
1 ,3 -Dichloropropene
Naphthalene
£>-Dichlorobenzene
Trichloroethylene
1,955.25
736.84
388.01
290.34
270.56
196.76
147.65
112.11
76.62
47.76
Coke Oven Emissions
Benzene
1,3 -Butadiene
Quinoline
Naphthalene
POM, Group 5
Cadmium, PM
Tetrachloroethylene
Hexavalent Chromium
POM, Group 2
2.50E-02
1.53E-02
5.90E-03
4.83E-03
3.81E-03
3.66E-03
3.16E-03
2.29E-03
2.20E-03
9.96E-04
Acetaldehyde
Carbon Tetrachloride
Benzene
1,3 -Butadiene
Acrylonitrile
Tetrachloroethylene
£>-Dichlorobenzene
Chloromethylbenzene
Hexavalent Chromium
Formaldehyde
10.88
9.50
7.44
3.03
1.88
1.52
1.39
1.33
0.50
0.03
Sault Sainte Marie, Michigan (ITCMI) - Chippewa County
Benzene
Formaldehyde
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Naphthalene
1 ,3 -Dichloropropene
/>-Dichlorobenzene
Trichloroethylene
83.87
23.23
18.21
9.74
7.76
6.10
2.81
2.80
1.49
1.42
Benzene
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
POM, Group 2
Arsenic, PM
Acrylonitrile
POM, Group 3
POM, Group 5
Acetaldehyde
6.54E-04
2.33E-04
1.07E-04
9.54E-05
7.26E-05
6.23E-05
4.51E-05
4.25E-05
2.20E-05
2.14E-05
Naphthalene
1.01
-------
Table 15-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Michigan
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Dearborn, Michigan (DEMI) - Wayne County
Toluene
Xylenes
Benzene
Hydrochloric acid
Methanol
Ethylbenzene
Hexane
Formaldehyde
Glycol ethers, gas
Methyl isobutyl ketone
5,059.56
3,410.03
1,955.25
1,627.76
907.48
768.20
749.98
736.84
476.41
469.79
Acrolein
Manganese, PM
1,3 -Butadiene
Cadmium, PM
Hydrochloric acid
Formaldehyde
Benzene
Bromomethane
Nickel, PM
Naphthalene
2,034,637.64
330,597.75
98,379.67
87,737.35
81,388.20
75,188.18
65,175.08
41,215.39
40,479.09
37,369.07
Acrolein
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Benzene
Carbon Tetrachloride
Acrylonitrile
Tetrachloroethylene
Hexavalent Chromium
/>-Dichlorobenzene
26.21
0.60
0.59
0.05
0.04
0.02
0.01
<0.01
<0.01
0.01
Sault Sainte Marie, Michigan (ITCMI) - Chippewa County
Toluene
Xylenes
Benzene
Ethylbenzene
Hexane
Formaldehyde
Tetrachloroethylene
Methanol
Acetaldehyde
Hydrochloric acid
317.92
192.77
83.87
43.41
34.64
23.23
18.21
15.62
9.74
9.45
Acrolein
1,3 -Butadiene
Benzene
Formaldehyde
Xylenes
Acetaldehyde
Cyanide Compounds, gas
Naphthalene
Toluene
Bromomethane
65,430.36
3,877.68
2,795.66
2,370.13
1,927.73
1,082.21
950.00
935.41
794.80
782.00
Naphthalene
0.01
-------
Observations from Table 15-9 include the following:
• Benzene, formaldehyde, and tetrachloroethylene were the highest emitted pollutants
with cancer UREs in both Wayne and Chippewa Counties, although the magnitude of
the emissions were very different.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) for Wayne County were coke oven emissions, benzene, and 1,3-
butadiene. The pollutants with the highest toxicity-weighted emissions for Chippewa
County were benzene, 1,3-butadiene, and tetrachloroethylene.
• Four of the highest emitted pollutants in Wayne County also had the highest toxicity-
weighted emissions. Five of the highest emitted pollutants in Chippewa County also
had the highest toxicity-weighted emissions.
• For DEMI, acetaldehyde, carbon tetrachloride, and benzene had the highest surrogate
cancer risk approximations. Carbon tetrachloride did not appear on either emissions-
based list. Acetaldehyde was one of the highest emitted pollutants, but did not appear
on the list of highest toxicity-weighted emissions.
• Benzene, 1,3-butadiene, and tetrachloroethylene appeared on all three lists for DEMI.
• For ITCMI, naphthalene appeared on all three lists.
Observations from Table 15-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in both Wayne and Chippewa Counties, although the magnitude of the
emissions were different.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) for Wayne County were acrolein, manganese, and 1,3-butadiene.
The pollutants with the highest toxicity-weighted emissions for Chippewa County
were acrolein, 1,3-butadiene, and benzene.
• Three of the highest emitted pollutants in Wayne County also had the highest
toxicity-weighted emissions. Five of the highest emitted pollutants in Chippewa
County also had the highest toxicity-weighted emissions.
• The pollutant with the highest noncancer risk approximation for DEMI was acrolein.
Acrolein was also the pollutant with the highest toxicity-weighted emissions, yet this
pollutant's emissions ranked 26th.
• For ITCMI, naphthalene was not one of the highest emitted pollutants, but appeared
on the list of highest toxicity-weighted emissions.
15-31
-------
15.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest for DEMI were ace taldehyde, acrolein, benzene, 1,3-
butadiene, carbon tetrachloride, p-dichlorobenzene, formaldehyde, and
tetrachloroethylene. Naphthalene was the only pollutant to failed screens for ITCMI.
»«» Formaldehyde had the highest daily average concentration for DEMI.
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmark for
DEMI.
15-32
-------
16.0 Sites in Mississippi
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at UATMP sites in Mississippi, and integrates these concentrations with
emissions, meteorological, and risk information.
16.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the locations of the sites and the surrounding areas. The GPMS monitoring
site is located in the Gulfport-Biloxi, MS MSA. TUMS is located in Tupelo, Mississippi.
Figures 16-1 and 16-2 are composite satellite images retrieved from Google™ Maps showing the
monitoring sites in their urban and rural locations. Figures 16-3 and 16-4 identify point source
emission locations within 10 miles of each site as reported in the 2002 NEI for point sources.
Table 16-1 describes the area surrounding each monitoring site and provides supplemental
geographical information such as land use, location setting, and locational coordinates.
GPMS is located in the coastal city of Gulfport, less than one mile from the shore and
approximately one half-mile from the Gulfport-Biloxi International Airport. The surrounding
area is lightly commercial as well as residential. The monitoring site is located behind the
Harrison County Youth Court building, as shown in Figure 16-1. The site is positioned between
several major thoroughfares through Gulfport, including Business 90, Pass Road, and 1-10.
Keesler Air Force Base and a U.S. Naval Reserve Station are within a few miles of the
monitoring site. As Figure 16-3 shows, few point sources are located near GPMS. Most of the
emission sources are located to the north of the site and are predominantly involved in surface
coating processes.
TUMS is located on the west side of Tupelo, a town in the northeast corner of the state.
Figure 16-2 shows that TUMS is located on the property of the Tupelo Regional Airport.
Residential and light commercial areas surround the airport. Busy roadways such as Natchez
Trace Parkway are located within a mile of the monitoring site. As Figure 16-4 shows, point
16-1
-------
Figure 16-1. Gulfport, Mississippi (GPMS) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 16-2. Tupelo, Mississippi (TUMS) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 16-3. NEI Point Sources Located Within 10 Miles of GPMS
Note: Due to facility density and collocation, the total facilities
displayed may not represent all facilities within the area of interest.
Legend
•&• GPMS UATMP Site
0 10 mile radius
| County boundary
Source Category Group (No. of Facilities)
D Fabricated Metal Products Facility (1)
L Liquids Distribution Industrial Facility (1)
& Lumber & Wood Products Facility (1}
National Security & International Affairs (1)
\ Non-ferrous Metals Processing Industrial Facility (1)
u Stone. Clay, Glass. & Concrete Products (1)
s Surface Coating Processes Industrial Facility (5)
a Utility Boilers (1)
i Waste Treatment & Disposal Industrial Facility (1)
16-4
-------
Figure 16-4. NEI Point Sources Located Within 10 Miles of TUMS
Mole: Due to facility density and collocation, the total facilities
displayed may not represent all facilities within the area of interest.
Legend
"& TUMS UATMP site
10 mile radius
_| County boundary
Source Category Group (No. of Facilities)
Chemicals & Allied Products Facility (3}
Fabricated Metal Products Facility (1)
Fuel Combustion Industrial Facility (1 )
Health Services Facility (1)
Miscellaneous Processes Industrial Facility (1)
Polymers & Resins Production Industrial Facility (4)
Stone, Clay, Glass, & Concrete Products (1 )
Surface Coating Processes Industrial Facility (5)
Waste Treatment & Disposal Industrial Facility (1)
c
D
F
+
P
v
u
s
*-
16-5
-------
Table 16-1. Geographical Information for the Mississippi Monitoring Sites
Site
Code
GPMS
TUMS
AQS Code
28-047-0008
28-081-0005
Location
Gulfport
Tupelo
County
Harrison
Lee
Micro- or
Metropolitan
Statistical Area
Gulfport-Biloxi,
MS
Tupelo, MS
Latitude
and
Longitude
30.390139,
-89.049722
34.264917,
-88.766222
Land Use
Commercial
Commercial
Location
Setting
Rural
Suburban
Description of the
Immediate Surroundings
The Gulfport site is in a light commercial and
residential area. This site was selected because this
area is believed to have high ambient air toxic
concentrations based upon information from the
NATA study and Mississippi's major source
emission inventories.
The Tupelo site is in a light commercial and
residential area. This site was selected because this
area is believed to have high ambient air toxic
concentrations based upon information from the
NATA study and Mississippi's major source
emission inventories.
Oi
-------
sources within a 10 mile radius of TUMS are primarily located to the east and southeast of the
site. A number of the emission sources near TUMS are involved in surface coating processes,
polymer and resin production, and chemical and allied products production.
Table 16-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Mississippi monitoring sites. County-level vehicle registration and population data for Harrison
and Lee Counties were obtained from the Mississippi State Tax Commission and the U.S.
Census Bureau. Table 16-2 also includes a vehicle registration to county population ratio
(vehicles per person). In addition, the population within 10 miles of each site is presented. An
estimate of 10-mile vehicle registration was calculated by applying the county-level vehicle
registration to population ratio to the 10-mile population surrounding each monitoring site.
Table 16-2 also contains annual average daily traffic information, as well as the year of the
traffic data estimate and the source from which it was obtained. Finally, Table 16-2 presents the
daily VMT for each urban area (where applicable).
Table 16-2. Population, Motor Vehicle, and Traffic Information for the Mississippi
Monitoring Sites
Site
GPMS
TUMS
2007
Estimated
County
Population
176,105
80,349
Number
of
Vehicles
Registered
170,041
71,812
Vehicles
per Person
(Registration:
Population)
0.97
0.89
Population
Within
10 Miles
155,056
71,697
Estimated
10 mile Vehicle
Ownership
149,717
64,079
Annual
Average
Traffic
Data1
27,000
12,000
VMT
(thousands)
6,936
NA
Daily Average Traffic Data reflects 2006 data from the Mississippi DOT
Observations from Table 16-2 include the following:
• The Harrison County population is more than twice the Lee County population,
although both relatively low compared to other counties with monitoring sites. The
same is true of the 10-mile populations.
• The county-level and 10-mile vehicle ownership estimates for GPMS and TUMS
reflect the same trends as the populations.
• The vehicle per person ratio for GPMS was nearly one vehicle per person, which falls
in the middle of the range compared to other program sites. The ratio for TUMS was
slightly lower than GPMS.
16-7
-------
GPMS experienced a higher annual average daily traffic volume than TUMS.
Compared to other program sites, the traffic near TUMS was rather low while the
traffic volume was in the middle of the range for GPMS. Traffic for GPMS was
obtained from Pass Road; traffic for TUMS was obtained from Coley Road, north of
State Road 6.
The Gulfport area VMT ranked fifth lowest among urban areas with UATMP or
NATTS sites. VMT was not available for the Tupelo area.
16.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Mississippi on sampling days, as well as over the course of the year.
16.2.1 Climate Summary
Climatologically, both of the Mississippi cities are warm and humid, especially Gulfport,
the site nearest the coast. High temperatures and humidity, due to proximity to the Gulf of
Mexico, can make this region feel uncomfortable. Precipitation is distributed fairly evenly
throughout the year, and thunderstorms are fairly common, especially in the summer and nearer
to the coast (Ruffner and Bair, 1987).
16.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at Gulfport-Biloxi Regional Airport (near GPMS) and Tupelo
Municipal Airport (near TUMS), WBAN 93874 and 93862, respectively.
Table 16-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 16-3 is the 95 percent
confidence interval for each parameter. As shown in Table 16-3, average meteorological
16-8
-------
Table 16-3. Average Meteorological Conditions near the Mississippi Monitoring Sites
Site
GPMS
TUMS
Closest NWS
Station and
WBAN
Gulfport,
MS/Biloxi
Regional Airport
93874
Tupelo
Municipal
Airport
93862
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
78.06
±2.91
76.79
±1.24
77.56
±3.94
75.77
±1.72
Average
Temperature
(op)
69.86
±2.97
68.13
± 1.29
66.62
±3.80
64.70
±1.64
Average
Dew Point
Temperature
(°F)
60.50
±3.34
58.60
±1.49
52.20
±3.94
50.63
±1.70
Average
Wet Bulb
Temperature
(°F)
64.31
±2.91
62.65
±1.28
58.53
±3.39
56.96
±1.49
Average
Relative
Humidity
(%)
74.52
±2.53
73.99
± 1.11
63.34
±3.04
63.88
±1.16
Average
Sea Level
Pressure
(mb)
1017.66
±1.19
1017.89
±0.48
1017.90
± 1.31
1018.27
±0.53
Average
Scalar Wind
Speed
(kt)
5.20
±0.67
5.37
±0.27
5.29
±0.59
5.22
±0.23
-------
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
16.2.3 Composite Back Trajectories for Sampling Days
Figures 16-5 and 16-6 are composite back trajectory maps for the Mississippi monitoring
sites for the days on which samples were collected. Each line represents the 24-hour trajectory
along which a parcel of air traveled toward the monitoring site on a sampling day. Each
concentric circle around the sites in Figures 16-5 and 16-6 represents 100 miles.
Observations from Figure 16-5 for GPMS include the following:
• Back trajectories originated from a variety of directions at the GPMS site. The
predominant direction of trajectory origin was from offshore, particularly from the
southeast.
• The 24-hour air shed domain for GPMS was somewhat smaller in size than TUMS
and other monitoring sites. The furthest away a trajectory originated was the central
Gulf of Mexico, or just over 500 miles away. However, most trajectories originated
within 300 miles.
Observations from Figure 16-6 for TUMS include the following:
• Back trajectories originated from a variety of directions at the TUMS site. The
predominant direction of trajectory origin was from the southeast, south, and
southwest.
• The 24-hour air shed domain for TUMS was comparable in size to other monitoring
sites. The furthest away a trajectory originated was Wisconsin, or greater than 600
miles away. However, most trajectories originated within 300 miles.
16.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations near the Mississippi sites, as presented in
Section 16.2.2, were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to
produce customized wind roses. A wind rose shows the frequency of wind directions on a 16-
point compass, and uses different shading to represent wind speeds. Figure 16-7 and 16-8 are the
wind roses for the Mississippi monitoring sites on days that samples were collected.
16-10
-------
Figure 16-5. Composite Back Trajectory Map for GPMS
0 37.5 75 150 225 300
Miles
-------
Figure 16-6. Composite Back Trajectory Map for TUMS
~y
c
.' * s .*•
0 50 100 200 300 400
ion
-------
Figure 16-7. Wind Rose for GPMS Sampling Days
WEST;
Figure 16-8. Wind Rose for TUMS Sampling Days
WEST 1
20%
16-13
-------
Observations from Figure 16-7 for GPMS include the following:
• Calm winds were prevailed near GPMS. They were observed for approximately 25
percent of the hourly measurements.
• Northerly and southeasterly winds were also observed frequently.
• Winds exceeding 11 knots made up approximately eight percent of observations. The
strongest winds often originated from the southeast.
Observations from Figure 16-8 for TUMS include the following:
• Similar to GPMS, calm winds were prevalent near TUMS. They were observed for
approximately 21 percent of the hourly measurements.
• For wind speeds greater than two knots, southerly winds were observed most
frequently, followed by northerly winds.
• Winds exceeding 11 knots made up six percent of observations. The strongest winds
often originated from the south.
16.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the
Mississippi monitoring sites were identified using the EPA risk screening process described in
Section 3.2. In brief, each pollutant's measured concentration was compared to its associated
risk screening value. If the daily concentration was greater than the risk screening value, then
the measured concentration "failed the screen." Pollutants of interest are those for which the
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 16-4 presents the pollutants that failed at least one screen for each Mississippi
monitoring sites and highlights each site's pollutants of interest (shaded). GPMS and TUMS
both sampled for VOC and carbonyls. In addition, SNMOC were also sampled at GPMS.
Observations from Table 16-4 include the following:
• Thirteen pollutants with a total of 433 measured concentrations failed at least one
screen for GPMS. Thirteen pollutants with a total of 370 measured concentrations
failed at least one screen for TUMS.
16-14
-------
Table 16-4. Comparison of Measured Concentrations and EPA Screening Values for the
Mississippi Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Gulfport, Mississippi - GPMS
Acetaldehyde
Acrolein
Carbon Tetrachloride
Benzene
Formaldehyde
1,3 -Butadiene
p-Dichlorobenzene
Acrylonitrile
Tetrachloroethylene
1 , 1 ,2,2-Tetrachloroethane
1 ,2-Dichloroethane
Dichloromethane
Xylenes
Total
62
61
61
61
60
53
39
17
14
2
1
1
1
433
62
61
61
61
62
60
61
17
53
2
1
61
61
623
100.00
100.00
100.00
100.00
96.77
88.33
63.93
100.00
26.42
100.00
100.00
1.64
1.64
69.50
14.32
14.09
14.09
14.09
13.86
12.24
9.01
3.93
3.23
0.46
0.23
0.23
0.23
14.32
28.41
42.49
56.58
70.44
82.68
91.69
95.61
98.85
99.31
99.54
99.77
100.00
Tupelo, Mississippi - TUMS
Carbon Tetrachloride
Acrolein
Benzene
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Acrylonitrile
£>-Dichlorobenzene
Tetrachloroethylene
Vinyl chloride
1 , 1 ,2-Trichloroethane
1 , 1 ,2,2-Tetrachloroethane
Hexachloro- 1 ,3 -butadiene
Total
61
60
60
58
51
48
17
6
5
1
1
1
1
370
61
60
61
58
58
59
17
45
52
28
3
1
1
504
100.00
100.00
98.36
100.00
87.93
81.36
100.00
13.33
9.62
3.57
33.33
100.00
100.00
73.41
16.49
16.22
16.22
15.68
13.78
12.97
4.59
1.62
1.35
0.27
0.27
0.27
0.27
16.49
32.7
48.92
64.59
78.38
91.35
95.95
97.57
98.92
99.19
99.46
99.73
100.00
16-15
-------
• The following seven pollutants of interest were common to both sites: acetaldehyde,
acrolein, acrylonitrile, benzene, 1,3-butadiene, carbon tetrachloride, and
formaldehyde.
• Of the seven common pollutants of interest, 100 percent of the measured detections of
acrolein, acrylonitrile, acetaldehyde, and carbon tetrachloride failed screens for both
sites.
• Of the pollutants with at least one failed screen, nearly 70 percent of measurements
failed screens for both sites.
16.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Mississippi monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
16.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where completeness was greater than or equal to 85 percent.
Daily, seasonal, and annual averages are presented in Table 16-5, where applicable.
Observations for GPMS from Table 16-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (2.55 ± 0.29 |ig/m3), acetaldehyde (1.55 ± 0.16 |ig/m3), and acrolein
(0.91±0.10|ig/m3).
16-16
-------
Table 16-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Mississippi Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(Hg/m3)
Summer
Average
(Hg/m3)
Autumn
Average
(jig/m3)
Annual
Average1
(jig/m3)
Gulfport, Mississippi - GPMS
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
62
61
17
61
60
61
61
62
62
61
61
61
61
61
61
62
1.55
±0.16
0.91
±0.10
0.21
±0.04
0.80
±0.08
0.07
±0.01
0.62
±0.03
0.22
±0.13
2.55
±0.29
1.47
±0.39
0.86
±0.27
NR
0.85
±0.13
0.09
±0.03
0.59
±0.07
0.09
±0.02
1.55
±0.26
1.84
±0.39
0.91
±0.17
0.12
±0.05
0.70
±0.13
0.05
±0.01
0.67
±0.07
0.11
±0.04
2.34
±0.54
1.59
±0.25
0.96
±0.18
0.11
±0.05
0.76
±0.18
0.06
±0.01
0.63
±0.08
0.47
±0.43
3.47
±0.57
1.25
±0.11
0.88
±0.16
NR
0.87
±0.19
0.07
±0.03
0.59
±0.04
0.16
±0.04
2.65
±0.34
1.55
±0.16
0.91
±0.10
0.08
±0.02
0.79
±0.08
0.07
±0.01
0.62
±0.03
0.22
±0.13
2.55
±0.29
Tupelo, Mississippi - TUMS
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
58
60
17
61
59
61
58
58
61
61
61
61
61
58
1.78
±0.24
0.59
±0.08
0.21
±0.03
0.65
±0.06
0.06
±0.01
0.58
±0.04
3.20
±0.59
1.99
±0.67
0.42
±0.17
NR
0.66
±0.12
0.06
±0.02
0.50
±0.09
1.33
±0.29
2.28
±0.51
0.56
±0.15
0.11
±0.05
0.64
±0.13
0.05
±0.01
0.62
±0.06
2.23
±0.64
1.64
±0.29
0.65
±0.16
0.12
±0.05
0.57
±0.10
0.05
±0.01
0.60
±0.08
5.95
±1.12
1.19
±0.17
0.68
±0.16
NR
0.72
±0.14
0.06
±0.03
0.57
±0.05
2.79
±0.49
1.78
±0.24
0.58
±0.08
0.08
±0.02
0.65
±0.06
0.05
±0.01
0.58
±0.04
3.20
±0.59
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
• As shown in Table 4-11, of the program-level pollutants of interest, GPMS had the
fifth highest daily average concentration of acrolein and second highest daily average
concentration of tetrachloroethylene. Tetrachloroethylene was not a pollutant of
interest for GPMS and is therefore not shown in Table 16-5.
• Concentrations of most of the pollutants of interest for GPMS did not vary
significantly from season to season. However, concentrations of formaldehyde were
highest during the summer.
16-17
-------
• The summer average concentration ofp-dichlorobenzene is significantly higher than
its other averages. However, the confidence interval is very high, indicating that this
average is influenced by outliers.
Observations for TUMS in Table 16-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (3.20 ± 0.59 |ig/m3), acetaldehyde (1.78 ± 0.24 |ig/m3), and benzene
(0.65 ± 0.06 |ig/m3).
• As shown in Table 4-11, of the program-level pollutants of interest, TUMS and
GPMS both had the eighth highest daily average concentration of acrylonitrile.
• Concentrations of most of the pollutants of interest for TUMS did not vary
significantly from season to season. However, concentrations of formaldehyde were
highest during the summer, similar to GPMS.
16.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. GPMS and TUMS have sampled VOC and carbonyls under the
UATMP since 2003. Figures 16-9 through 16-14 present the three-year rolling statistical metrics
graphically for benzene, 1,3-butadiene, and formaldehyde for each site. Both sites have sampled
since 2001. GPMS, however, stopped sampling briefly in 2005 until the post-Hurricane Katrina
monitoring effort began. Metrics incorporating data collected as part of that effort are denoted in
the Figures by an asterisk (*). The statistical metrics presented for calculating trends include the
substitution of zeros for non-detects.
Observations from Figure 16-9 for benzene measurements at GPMS include the
following:
• The maximum benzene concentration shown was measured in 2005.
• The rolling average concentrations vary between 0.3 and 0.4 ppbv, but were highest
during the 2001-2003 time frame and lowest during the 2005-2007 time frame.
• Two non-detects were recorded during the first two years of sampling. After 2002,
all benzene concentrations reported to AQS were measured detections.
16-18
-------
Figure 16-9. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at GPMS
2.50 i
2.00 -
£ 1.50 -
c.
c.
a
_0
"S
"S
a
o
y
1.00
o.oo
T
T
2001-2003
2002-2004
2003-2005*
Three-Year Period
2004-2006* 2005-2007*
* includes data from post-Hurricane Katrina monitoring
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 16-10. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at GPMS
to
o
0.35 -,
0.20
o
U
0.10
0.05 -
2001-2003
2002-2004
2003-2005*
Three-Year Period
2004-2006* 2005-2007*
' includes data from post-Hurricane Katrina monitoring
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 16-11. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at GPMS
12.00
10.00
3.00
o.
o.
1
o
(J
4.00
0.00
T
2001-2003
2002-2004
2003-2005*
Three-Year Period
2004-2006* 2005-2007*
* includes data from post-Hurricane Katrina monitoring
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 16-12. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at TUMS
2.00
to
to
1.60
1.40
r* 1 .Z.U
o.
a
=
I i.oo
I—> a
0.60
OA
0.2
0.00
2001-2003
T
T
2002-2004
2003-2005
Three-Year Period
2004-2006
2005-2007
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 16-13. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at TUMS
to
n 90
> n i ^
1 C
3 C
qdd) uoije-ijuaauc
y u-iu
n ns
n nn
<
>
2001-2003
.<
:
>
o
2002-2004 2003-2005 2004-2006
Three- Year Period
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
••II
2005-2007
-------
Figure 16-14. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at TUMS
to
12.00
10.00
3.00 -
c.
&
a
1 6.00
"3
o
CJ
I
4.C
2.00
0.00
2001-2003
T
2002-2004
2003-2005
Three-Year Period
2004-2006
T
2005-2007
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Observations from Figure 16-10 for 1,3-butadiene measurements at GPMS include the
following:
• The rolling metrics for 1,3-butadiene look very different than the rolling metrics for
benzene, primarily due to the impact of the frequency of detection rather than the
magnitude of the measurements.
• The minimum and first quartile were both zero for the 2001-2003 time frame, and
minimum, first quartile, and median concentrations for the 2002-2004 time frame
were zero. The detection rate actually decreased between the time frames, from 33
percent to 20 percent.
• As the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for this
pollutant increased. This pollutant was detected in 67 percent of samples during the
2003-2005 time frame; 80 percent of samples during 2004-2006; and 94 percent of
samples during 2005-2007.
• As the detection rate increased, the median value increased as well. The median and
rolling average concentrations shown became more similar over the last three periods,
which indicates decreasing variability in the central tendency.
• The highest concentration of 1,3-butadiene was measured in 2005, on the same day
that the highest concentration of benzene was measured.
Observations from Figure 16-11 for formaldehyde measurements at GPMS include the
following:
• The maximum formaldehyde concentration shown was measured in 2005, but not the
same day as benzene and 1,3-butadiene.
• There is a slight decrease in the average concentration from 2001-2003 to 2002-2004,
then a slight increase for each additional period shown.
• The central tendency of the rolling averages and the median values were similar to
each other for each time period. The "closeness" in these metrics indicates relatively
little variability in the central tendency.
• All formaldehyde concentrations reported to AQS over the seven years of sampling
were measured detections.
16-25
-------
Observations from Figure 16-12 for benzene measurements at TUMS include the
following:
• The maximum benzene concentration shown was measured in 2006.
• Although the range of concentrations measured has increased, the rolling average and
median concentrations have decreased slightly since the onset of sampling.
• A single non-detect was recorded during the second year of sampling. After 2002, all
benzene concentrations reported to AQS were measured detections.
Observations from Figure 16-13 for 1,3-butadiene measurements at TUMS include the
following:
• The rolling metrics for the first five years of 1,3-butadiene sampling look very similar
to the rolling metrics from GPMS for the 2002-2004 time frame. The minimum, first
quartile, and median concentrations for the first three time frames were all zero.
• The minimum, first quartile, and median concentrations for both the 2001-2003 and
the 2002-2004 time frames were zero. The detection rate decreased between the first
two time frames, then increased during the third (21, 8, and 22 percent, respectively)
• As the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for this
pollutant increased. The detection rate for the final time frame (2005-2007) was
nearly 80 percent.
• As the detection rate increased, the median value increased as well. The median and
rolling average concentrations shown became more similar over the last three periods,
which indicates decreasing variability in the central tendency.
• The highest concentration of 1,3-butadiene was measured in 2001.
Observations from Figure 16-14 for formaldehyde measurements at TUMS include the
following:
• The average concentrations show a decreasing trend from the 2001-2003 time frame
until the 2004-2006 time frame. An increase is shown for 2005-2007.
• The rolling averages and the median values became more similar for each time period
through 2004-2006. The increasing "closeness" in these metrics indicates decreasing
variability in the central tendency. The difference widens between the two metrics in
the final time frame.
16-26
-------
• The maximum formaldehyde concentration shown was measured in 2007. However,
the maximum concentration measured in 2001 was just slightly lower.
• All formaldehyde concentrations reported to AQS over the seven years of sampling
were measured detections.
16.5 Pearson Correlations
Table 16-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for GPMS from Table 16-6 include the following:
• Formaldehyde exhibited strong positive correlations with the temperature parameters,
indicating that an increase in temperature results in a proportionate increase in
concentration. This supports the observations from Table 16-5.
• 1,3-Butadiene exhibited strong negative correlations with the maximum, dew point,
and wet bulb temperatures, indicating that an increase in temperature and moisture
content results in a proportionate decrease in concentration.
• Acetaldehyde exhibited a strong negative correlation with relative humidity,
indicating that an increase in moisture content results in a proportionate decrease in
concentration. The correlations with wet bulb and dew point temperatures were also
negative, but did not show the same strength in correlation.
• All but one of the correlations with scalar wind speed were negative, indicating that
as wind speed decreases, concentrations of the pollutants of interest may increase at
GPMS.
Observations for TUMS from Table 16-6 include the following:
• Similar to TUMS, formaldehyde exhibited strong positive correlations with the
temperature parameters. In addition, this pollutant also exhibited strong positive
correlations with the dew point and wet bulb temperatures. This supports the
observations from Table 16-5.
• Acrylonitrile also exhibited strong positive correlations with the temperature and
moisture parameters.
• All of the correlations with scalar wind speed were negative, indicating that as wind
speed decreases, concentrations of the pollutants of interest may increase at TUMS.
16-27
-------
Table 16-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
Mississippi Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Gulf port, Mississippi - GPMS
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
62
61
17
61
60
61
61
62
-0.02
0.18
0.03
-0.12
-0.47
0.18
0.16
0.63
-0.15
0.20
0.10
-0.15
-0.52
0.25
0.14
0.54
-0.32
0.19
0.13
-0.13
-0.50
0.29
0.18
0.38
-0.26
0.19
0.13
-0.13
-0.51
0.29
0.17
0.45
-0.54
0.06
0.05
-0.01
-0.15
0.23
0.18
-0.29
0.02
-0.25
-0.12
0.12
0.29
-0.09
-0.16
-0.39
-0.36
-0.08
-0.16
-0.42
-0.44
0.08
-0.14
-0.36
Tupelo, Mississippi - TUMS
1,3 -Butadiene
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
Carbon Tetrachloride
Formaldehyde
59
58
60
17
61
61
58
-0.14
-0.10
0.26
0.45
-0.02
0.27
0.77
-0.22
-0.16
0.24
0.51
-0.04
0.29
0.73
-0.21
-0.29
0.19
0.54
0.01
0.39
0.58
-0.23
-0.25
0.20
0.55
-0.03
0.34
0.65
0.01
-0.39
-0.06
0.16
0.15
0.34
-0.21
0.17
0.34
-0.15
0.53
0.06
-0.16
-0.28
-0.42
-0.31
-0.10
-0.31
-0.39
-0.14
-0.39
to
oo
-------
16.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
16.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the
Mississippi monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where
available. As described in Section 3.3, acute risk results from exposures of 1 to 14 days;
intermediate risk results from exposures of 15 to 364 days; and chronic risk results from
exposures of one year or greater. The preprocessed daily measurements of the pollutants that
failed at least one screen were compared to the acute MRL; the seasonal averages were
compared to the intermediate MRL; and the annual averages were compared to the chronic
MRL. The results of these comparisons are summarized in Table 16-7. Where a seasonal or
annual average exceeds the applicable MRL, the concentration is bolded. Acrolein exceeded one
or more of the MRL risk factors for both sites.
Observations about acrolein from Table 16-7 include the following:
• None of the preprocessed daily measurements of acrolein from the Mississippi sites
exceeded the acute MRL.
• All four seasonal averages of acrolein exceeded the intermediate MRL for both sites.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
16.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Mississippi monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
16-29
-------
Table 16-7. MRL Risk Screening Assessment Summary for the Mississippi Monitoring Sites
Site
GPMS
TUMS
Method
TO-15
TO-15
Pollutant
Acrolein
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/61
0/60
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
0.09
Winter
Average
(Ug/m3)
0.86
±0.27
0.42
±0.17
Spring
Average
(Ug/m3)
0.91
±0.17
0.56
±0.15
Summer
Average
(Ug/m3)
0.96
±0.18
0.65
±0.16
Autumn
Average
(Ug/m3)
0.88
±0.16
0.68
±0.16
ATSDR
Chronic
MRL
(Ug/m3)
~
-
Annual
Average1
(Ug/m3)
0.91
±0.10
0.58
±0.08
BOLD = exceedance of the intermediate or chronic MRL
~ = an MRL risk factor is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
oo
O
-------
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 16-8. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the Mississippi monitoring sites is as follows:
• The census tract for GPMS is 28047001700, which had a population of 6,200 and
represented approximately 3.3 percent of the Harrison County population in 2000.
• The census tract for TUMS is 280081950600, which had a population of 7,862, and
represented approximately 10 percent of the Lee County population in 2000.
Observations for GPMS from Table 16-8 include the following:
• The pollutants with the highest concentrations according to NATA were xylenes,
acetaldehyde, and formaldehyde.
• The pollutants with the highest cancer risks according to NATA were benzene,
carbon tetrachloride, and 1,1,2,2-tetrachloroethane.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (2.96).
• The pollutants with the highest 2007 annual averages were xylenes, formaldehyde,
and acetaldehyde.
• The pollutants with the highest surrogate cancer risk approximations were carbon
tetrachloride, benzene, and acrylonitrile.
• Acrolein was the only pollutant with a noncancer risk approximation greater than 1.0.
(45.31).
Observations for TUMS from Table 16-8 include the following:
• The pollutants with the highest concentrations according to NATA were benzene,
acetaldehyde, and formaldehyde.
• The pollutants with the highest cancer risks according to NATA were benzene,
carbon tetrachloride, and 1,1,2-trichloroethane.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (2.05).
16-31
-------
Table 16-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Mississippi
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Hg/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Hg/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Gulfport, Mississippi (GPMS) - Census Tract ID 28047001700
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
1 ,2-Dichloroethane
Dichloromethane
Formaldehyde
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Xylenes
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000011
0.000026
0.00000047
5.5E-09
0.000058
0.000005
-
0.009
0.00002
0.002
0.03
0.002
0.04
0.8
2.4
1
0.0098
—
0.27
0.1
0.97
0.06
0.01
0.90
0.07
0.21
0.02
0.03
0.28
0.97
0.04
0.12
1.72
2.16
—
0.01
7.02
1.99
3.17
0.22
0.67
0.13
0.01
2.23
0.70
-
0.10
2.96
0.01
0.03
0.03
0.01
O.01
0.01
0.01
0.09
—
O.01
0.01
1.55 ±0.16
0.91 ±0.10
0.08 ±0.02
0.79 ±0.08
0.07 ±0.01
0.62 ±0.03
0.22 ±0.13
0.04 ±0.01
0.39 ±0.08
2.55 ±0.29
0.05 ± 0.01
0.54 ±0.55
1.68 ±0.45
3.10
—
5.24
5.53
1.97
9.33
2.40
1.10
0.18
0.01
3.18
2.71
-
0.17
45.31
0.04
0.03
0.03
0.02
O.01
0.01
0.01
0.26
—
O.01
0.02
to
- = a URE or RfC is not available
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 16-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Mississippi (Continued)
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Hg/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Hg/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Tupelo, Mississippi (TUMS) - Census Tract ID 28081950600
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Hexachloro- 1 ,3 -butadiene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
1 , 1 ,2-Trichloroethane
Vinyl chloride
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000011
5.5E-09
0.000022
0.000058
0.000005
0.000016
0.000008
0.009
0.00002
0.002
0.03
0.002
0.04
0.8
0.0098
0.09
~
0.27
0.4
0.1
0.81
0.04
0.01
0.90
0.05
0.21
0.02
0.76
0.01
0.02
0.06
0.12
0.01
1.80
—
0.01
7.05
1.55
3.13
0.22
0.01
0.03
1.26
0.38
1.93
0.11
0.09
2.05
0.01
0.03
0.02
0.01
O.01
0.07
0.01
~
O.01
O.01
0.01
1.78 ±0.24
0.58 ±0.08
0.08 ±0.02
0.65 ±0.06
0.05 ±0.01
0.58 ±0.04
0.06 ±0.01
3.20 ±0.59
0.20 ± 0.02
0.06 ±O.01
0.12 ±0.06
0.05 ± O.01
0.03 ±0.01
3.56
—
5.23
4.55
1.65
8.63
0.65
0.02
4.45
3.22
0.60
0.76
0.26
0.20
28.92
0.04
0.02
0.03
0.01
O.01
0.33
0.01
~
O.01
O.01
0.01
- = a URE or RfC is not available
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
• The pollutants with the highest 2007 annual averages were formaldehyde,
acetaldehyde, benzene, and acrolein.
• The pollutants with the highest surrogate cancer risk approximations were carbon
tetrachloride, acrylonitrile, and benzene, which was similar to GPMS.
• Acrolein was the only pollutant with a noncancer risk approximation greater than 1.0.
(28.92).
16.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 16-9 and 16-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 16-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
surrogate cancer risk approximations (in-a-million), as calculated from the annual averages.
Table 16-10 presents similar information, but identifies the 10 pollutants with the highest
noncancer risk approximations (HQ), as calculated from the annual averages. The pollutants in
these tables are limited to those that have cancer and noncancer risk factors, respectively. As a
result, although the actual value of the emissions are the same, the highest emitted pollutants in
the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
risk approximations based on each site's annual averages are limited to those pollutants for
which each respective site sampled. As discussed in Section 16.3, GPMS and TUMS both
sampled for VOC and carbonyl compounds; GPMS also sampled for SNMOC. In addition, the
cancer and noncancer surrogate risk approximations are limited to those sites sampling for a long
enough period for annual averages to be calculated.
Observations from Table 16-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Harrison County. Dichloromethane was the highest emitted pollutant
in Lee County, followed by benzene, formaldehyde, and acetaldehyde.
16-34
-------
Table 16-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Mississippi
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Gulfport, Mississippi (GPMS) - Harrison County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Tetrachloroethylene
Naphthalene
/>-Dichlorobenzene
Trichloroethylene
POM, Group 2
221.28
70.95
27.85
20.97
16.45
16.04
4.84
4.09
1.21
1.16
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Arsenic, PM
Tetrachloroethylene
POM, Group 2
Acetaldehyde
Nickel, PM
£>-Dichlorobenzene
1.73E-03
6.29E-04
1.89E-04
1.64E-04
1.22E-04
9.46E-05
6.40E-05
6.13E-05
4.53E-05
4.50E-05
Carbon Tetrachloride
Benzene
Acrylonitrile
1, 1,2,2-Tetrachloroethane
Acetaldehyde
Tetrachloroethylene
£>-Dichlorobenzene
1,3 -Butadiene
1 ,2-Dichloroethane
Dichloromethane
9.33
5.53
5.23
3.19
3.10
2.71
2.40
1.97
1.11
0.18
Tupelo, Mississippi (TUMS) - Lee County
Dichloromethane
Benzene
Formaldehyde
Acetaldehyde
Naphthalene
1,3 -Butadiene
Tetrachloroethylene
Trichloroethylene
£>-Dichlorobenzene
Nickel, PM
213.35
128.71
31.20
11.19
9.89
9.44
6.29
2.39
1.65
0.88
Hexavalent Chromium
Benzene
Naphthalene
1,3 -Butadiene
Nickel, PM
Arsenic, PM
Dichloromethane
Cadmium, PM
POM, Group 2
Tetrachloroethylene
2.45E-03
l.OOE-03
3.36E-04
2.83E-04
1.40E-04
1.23E-04
l.OOE-04
9.86E-05
4.00E-05
3.71E-05
Carbon Tetrachloride
Acrylonitrile
Benzene
Hexachloro- 1 ,3 -butadiene
Acetaldehyde
1 , 1 ,2,2-Tetrachloroethane
1,3 -Butadiene
1,1,2-Trichloroethane
£>-Dichlorobenzene
Tetrachloroethylene
8.63
5.21
4.55
4.48
3.56
3.22
1.65
0.77
0.65
0.60
-------
Table 16-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Mississippi
Oi
OJ
Oi
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Gulfport, Mississippi (GPMS) - Harrison County
Hydrochloric acid
Xylenes
Toluene
Benzene
Ethylbenzene
Hexane
Methanol
Hydrofluoric acid
Formaldehyde
Methyl isobutyl ketone
1,034.41
913.82
681.78
221.28
195.13
173.04
123.31
78.09
70.95
70.81
Acrolein
Hydrochloric acid
Chlorine
1,3 -Butadiene
Manganese, PM
Xylenes
Benzene
Formaldehyde
Nickel, PM
Cyanide Compounds, gas
228,271.03
5,1720.73
16,950.00
10,485.95
9950.47
9138.24
7376.01
7239.59
4355.41
3493.33
Acrolein
Formaldehyde
Acetaldehyde
Acrylonitrile
1,3 -Butadiene
Benzene
Carbon Tetrachloride
Xylenes
Tetrachloroethylene
Dichloromethane
45.31
0.26
0.17
0.04
0.03
0.03
0.02
0.01
0.01
<0.01
Tupelo, Mississippi (TUMS) - Lee County
Toluene
Xylenes
Dichloromethane
Methyl isobutyl ketone
Benzene
Glycol ethers, gas
Methanol
Hexane
Ethylbenzene
Formaldehyde
315.99
223.51
213.35
199.37
128.71
63.75
55.58
50.67
40.92
31.20
Acrolein
Nickel, PM
1,3 -Butadiene
Benzene
2,4-Toluene diisocyanate
Naphthalene
Manganese, PM
Glycol ethers, gas
Formaldehyde
Cadmium, PM
90,138.26
13,509.21
4,718.07
4,290.41
4,091.84
3,296.01
3,193.94
3,187.32
3,183.87
2,739.45
Acrolein
Formaldehyde
Acetaldehyde
Acrylonitrile
1,3 -Butadiene
Benzene
Carbon Tetrachloride
Hexachloro- 1 ,3 -butadiene
Tetrachloroethylene
Vinyl chloride
28.92
0.33
0.20
0.04
0.03
0.02
0.01
0.01
0.01
O.01
-------
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) for Harrison County were benzene, 1,3-butadiene, and hexavalent
chromium. Hexavalent chromium was the pollutant with the highest toxicity-
weighted emissions for Lee County, followed by benzene and naphthalene.
• Seven of the highest emitted pollutants in Harrison County also had the highest
toxi city-weighted emissions. Six of the highest emitted pollutants in Lee County also
had the highest toxicity-weighted emissions.
• For GPMS, carbon tetrachloride, benzene, and acrylonitrile had the highest surrogate
cancer risk approximations. These pollutants also topped the list for TUMS, although
in a different order. Neither carbon tetrachloride nor acrylonitrile appeared on either
emissions-based list, while benzene appeared on all three lists.
Observations from Table 16-10 include the following:
• Hydrochloric acid, toluene, and xylenes were the highest emitted pollutants with
noncancer RfCs in Harrison County. Toluene, xylenes, and dichloromethane were
the highest emitted pollutants in Lee County.
• The pollutant with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) for both counties was acrolein.
• Four of the highest emitted pollutants in Harrison County also had the highest
toxicity-weighted emissions. Three of the highest emitted pollutants in Lee County
also had the highest toxicity-weighted emissions.
• The pollutant with the highest noncancer risk approximation for both sites was
acrolein. Acrolein was also the pollutant with the highest toxicity-weighted
emissions, yet this pollutant's county-level emissions ranked 22nd for GPMS and 23rd
for TUMS.
16.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Mississippi monitoring site were
acetaldehyde, acrolein, acrylonitrile, benzene, 1,3-butadiene, carbon tetrachloride,
and formaldehyde.
»«» Formaldehyde had the highest daily average concentration for each of the monitoring
sites.
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmark for
both monitoring sites.
16-37
-------
17.0 Site in Missouri
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Missouri, and integrates these concentrations with
emissions, meteorological, and risk information.
17.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The S4MO site is located in
the St. Louis, MO-IL MSA. Figure 17-1 is a composite satellite image retrieved from Google™
Maps showing the monitoring site in its urban location. Figure 17-2 identifies point source
emission locations within 10 miles of the site as reported in the 2002 NEI for point sources.
Table 17-1 describes the area surrounding the monitoring site and provides supplemental
geographical information such as land use, location setting, and locational coordinates.
S4MO is located in central St. Louis. Figure 17-1 shows that the S4MO monitoring site
is located less than a quarter-mile from 1-70. The Mississippi River, which separates Missouri
from Illinois, is less than a mile east of the site. Although the area directly around the
monitoring site is residential, industrial facilities are located just on the other side of 1-70. Figure
17-2 shows a large number of point sources are located within 10 miles of S4MO. Some of the
most numerous emission sources are involved in fuel combustion processes, chemical and allied
product production, liquids distribution, and surface coating processes. In the immediate vicinity
of S4MO are an organic chemical production facility to the east and a wood furniture production
facility to the west.
Table 17-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Missouri monitoring site. County-level vehicle registration and population data for St Louis City
and County were obtained from the Missouri Department of Revenue and the U.S. Census
Bureau. Table 17-2 also includes a vehicle registration to county population ratio (vehicles per
17-1
-------
Figure 17-1. St. Louis, Missouri (S4MO) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 17-2. NEI Point Sources Located Within 10 Miles of S4MO
Legend
•& S4MO NATTS site 10 mile radius
Source Category Group (No, of Facilities)
* Agricultural Chemicals Production Industrial Facility (1)
* Automotive Repair Services, & Parting (1 >
Business Services Facility (2)
C Chemicals 5 Allied Products Facility 11 D|
Z Electrical & Electronc Equipment Facdrty |11
• Engineering S Management Services Facility (1 >
0 Fabricated Metal Products Facitty (3)
8 Fowl & Kindred Products Facifcty (1)
F Fuel Consbuston Industrial Faciity (51)
•i- Hearth Services Facility < I)
< I ncineration Industrial Facility (1)
•l Industrial Machinery & Equipment Facility (2)
• Integrated Iron & Stetl Manufacturing Faciity (2)
L Ltquxfe Distribution Industrial Facility (10)
B Mineral Products Processing Industrial Facility {2}
industrial
i W*"-0-Vi
nenan rh* Pharmaceutical Production Processes Industrial Facility (3|
Primary Metal Industrie's. FaciWy (2)
Printing & Publishing Facility (3)
Producton of Organic Clwmicate Industral Facftty (7)
Railroad Transportation { 1 1
Rubber & Miscellaneous Plastic Products Facility 12)
Stone, Clay. Glass, & Concrete Products (5>
Surface Coating Processes Industrial Facility (12)
Utility Boilers (2)
Waste Treatment * Disposa I Industrial Facility (4)
Q
R
$ Wfhotesa le Trade - Durable Goods (2)
* Wood Furniture Facility (1 )
17-3
-------
Table 17-1. Geographical Information for the Missouri Monitoring Site
Site
Code
S4MO
AQS Code
29-510-0085
Location
St. Louis
County
St. Louis
Micro- or
Metropolitan
Statistical Area
St. Louis, MO-IL
Latitude
and
Longitude
38.656436,
-90.198661
Land Use
Residential
Location
Setting
Urban/City
Center
Description of the
Immediate Surroundings
Blair Street has some industry around it and a fair
amount of industry to the east. The site is also only
about 220 meters from 1-70 (at its closest point).
BOLD = EPA-designated NATTS Site
-------
Table 17-2. Population, Motor Vehicle, and Traffic Information for the Missouri
Monitoring Site
Site
S4MO
2007
Estimated
County
Population
1,345,877
Number
of
Vehicles
Registered
1,136,095
Vehicles
per Person
(Registration:
Population)
0.84
Population
Within
10 Miles
816,098
Estimated
10 mile Vehicle
Ownership
688,893
Annual
Average
Traffic
Data1
84,821
VMT
(thousands)
63,584
1 Daily Average Traffic Data reflects 2006 data from the Missouri DOT
BOLD = EPA-designated NATTS Site
person). In addition, the population within 10 miles of each site is presented. An estimate of
10-mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 17-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 17-2 presents the daily VMT for the
urban area.
Observations from Table 17-2 include the following:
• S4MO's county and 10-mile populations were in the upper to mid-range compared to
all counties with NATTS or UATMP sites. This is also true for its county-level and
10-mile vehicle ownership.
• The vehicle per person ratio was in the middle of the range compared to other
NATTS or UATMP sites.
• The traffic volume experienced near S4MO ranked thirteenth highest compared to
other monitoring sites. The traffic estimate used came from 1-70 near exit 250.
• The St. Louis area VMT was the thirteenth highest among urban areas with UATMP
or NATTS sites. The St. Louis VMT was very similar to the Tampa area VMT.
17.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Missouri on sampling days, as well as over the course of the year.
17-5
-------
17.2.1 Climate Summary
St. Louis has a climate that is continental in nature, with cold, dry winters; warm,
somewhat wetter summers; and significant seasonal variability. Warm, moist air flowing
northward from the Gulf of Mexico alternating with cold, dry air marching southward from
Canada and the northern U.S. results in weather patterns that do not persist for very long
(Ruffner and Bair, 1987).
17.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at St. Louis Downtown Airport (WBAN 03960).
Table 17-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 17-3 is the 95 percent
confidence interval for each parameter. As shown in Table 17-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
17.2.3 Composite Back Trajectories for Sampling Days
Figure 17-3 is a composite back trajectory map for the Missouri monitoring site for the
days on which samples were collected. Each line represents the 24-hour trajectory along which a
parcel of air traveled toward the monitoring site on a sampling day. Each concentric circle
around the site in Figure 17-3 represents 100 miles.
17-6
-------
Table 17-3. Average Meteorological Conditions near the Missouri Monitoring Site
Site
S4MO
Closest NWS
Station and
WBAN
St. Louis
Downtown
Airport
03960
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
70.05
±4.91
67.68
±2.15
Average
Temperature
(op)
59.85
±4.44
57.50
±1.97
Average
Dew Point
Temperature
(°F)
47.20
±4.23
45.23
±1.92
Average
Wet Bulb
Temperature
(»F)
53.08
±3.93
51.11
±1.76
Average
Relative
Humidity
(%)
66.35
±2.65
66.96
± 1.20
Average
Sea Level
Pressure
(mb)
1017.70
±1.46
1018.04
±0.62
Average
Scalar Wind
Speed
(kt)
6.21
±0.83
5.98
±0.32
BOLD = EPA-designated NATTS Site
-------
Figure 17-3. Composite Back Trajectory Map for S4MO
00
- - - - -~^- Jg fi
A
•\ v
\ \
.
'- • • 3» 300 400
^ • ^^^^m ^^^^•ni
-------
Observations from Figure 17-3 include the following:
• Back trajectories originated from a variety of directions at S4MO. The bulk of the
trajectories originated from the southwest and northwest.
• The 24-hour air shed domain for S4MO was comparable in size to other monitoring
sites. The furthest away a trajectory originated was North Dakota, or more than 700
miles away. However, 90 percent of trajectories originated within 500 miles of the
site.
17.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at the St. Louis Downtown Airport near
S4MO were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce
customized wind roses. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figure 17-4 is the wind rose for
the Missouri monitoring site on days that samples were collected.
Figure 17-4. Wind Rose for S4MO Sampling Days
15%
17-9
-------
Observations from Figure 17-4 for S4MO include the following:
• Calm winds were prevalent near S4MO and were observed for approximately 22
percent of the hourly wind measurements.
• Southerly and south-southeasterly winds were frequently observed near S4MO.
• Winds exceeding 11 knots made up approximately 14 percent of observations and
were most frequently measured for winds with a westerly component.
17.3 Pollutants of Interest
"Pollutants of interest" were determined for the site in order to allow analysts and readers
to focus on a risk-based subset of pollutants. The pollutants of interest for the Missouri
monitoring site were identified using the EPA risk screening process described in Section 3.2. In
brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 17-4 presents the pollutants that failed at least one screen for the Missouri monitoring site
and highlights the site's pollutants of interest (shaded). S4MO sampled for VOC, carbonyls,
metals (PMi0), and hexavalent chromium.
Observations from Table 17-4 include the following:
• Seventeen pollutants with a total of 579 measured concentrations failed at least one
screen for S4MO.
• The following eleven pollutants were identified as pollutants of interest for S4MO:
acetaldehyde, acrolein, arsenic, benzene, 1,3-butadiene, cadmium, carbon
tetrachloride, formaldehyde, manganese, />-dichlorobenzene, and tetrachloroethylene.
• Of the eleven pollutants of interest, six failed 100 percent of screens for S4MO.
• Nearly 67 percent of measured detections failed screens (of the pollutants that failed
at least one screen) for S4MO.
17-10
-------
Table 17-4. Comparison of Measured Concentrations and EPA Screening Values for
Missouri Monitoring Site
the
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
St. Louis, Missouri - S4MO
Carbon Tetrachloride
Benzene
Arsenic (PM10)
Acetaldehyde
Acrolein
Formaldehyde
Manganese (PM10)
1,3 -Butadiene
Cadmium (PM10)
£>-Dichlorobenzene
Tetrachloroethylene
Hexavalent Chromium
Acrylonitrile
Nickel (PM10)
Dichloromethane
Trichloroethylene
1 , 1 ,2,2-Tetrachloroethane
Total
61
61
60
60
60
60
57
56
33
30
24
7
4
3
1
1
1
579
61
61
60
60
60
60
60
59
60
57
60
49
4
60
61
32
1
865
100.00
100.00
100.00
100.00
100.00
100.00
95.00
94.92
55.00
52.63
40.00
14.29
100.00
5.00
1.64
3.13
100.00
66.94
10.54
10.54
10.36
10.36
10.36
10.36
9.84
9.67
5.70
5.18
4.15
1.21
0.69
0.52
0.17
0.17
0.17
10.54
21.07
31.43
41.80
52.16
62.52
72.37
82.04
87.74
92.92
97.06
98.27
98.96
99.48
99.65
99.83
100.00
17.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Missouri monitoring site. The averages presented are provided for the pollutants of
interest for the site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the site, where applicable.
17.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
17-11
-------
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 17-5, where applicable.
Table 17-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Missouri Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(Hg/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(jig/m3)
Annual
Average1
(Ug/m3)
St. Louis, Missouri - S4MO
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Cadmium (PM10)
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Manganese (PM10)
Tetrachloroethylene
60
60
60
61
59
60
61
57
60
60
60
60
61
60
61
61
60
61
61
60
60
61
4.06
±0.52
0.79
±0.12
O.01
±<0.01
0.83
±0.14
0.09
±0.02
0.01
±0.01
0.58
±0.03
0.26
±0.10
4.57
±0.68
0.01
±0.01
0.20
±0.05
2.86
±0.41
0.49
±0.13
O.01
±0.01
0.77
±0.19
0.09
±0.03
0.01
± 0.01
0.54
±0.08
0.07
±0.02
2.20
±0.37
0.01
±0.01
0.13
±0.04
3.44
±0.43
0.86
±0.27
O.01
±0.01
0.65
±0.11
0.06
±0.01
0.01
±0.01
0.61
±0.05
0.26
±0.21
4.16
±0.92
0.01
±0.01
0.17
±0.04
4.68
±0.64
0.99
±0.26
O.01
±O.01
0.75
±0.22
0.08
±0.01
0.01
±0.01
0.56
±0.06
0.46
±0.25
7.70
±1.21
0.01
±0.01
0.18
±0.04
5.24
± 1.73
0.73
±0.20
O.01
±O.01
1.17
±0.44
0.15
±0.08
0.01
± 0.01
0.59
±0.06
0.17
±0.09
3.81
±0.70
0.01
±0.01
0.31
±0.15
4.06
±0.52
0.78
±0.12
O.01
±O.01
0.83
±0.14
0.09
±0.02
0.01
±0.01
0.58
±0.03
0.25
±0.10
4.57
±0.68
0.01
±0.01
0.20
±0.04
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for S4MO from Table 17-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (4.57 ± 0.68 |ig/m3), acetaldehyde (4.06 ± 0.52 |ig/m3), and benzene
(0.83 ± 0.14 jig/m3). The annual averages for these pollutants were the same as their
respective daily averages.
17-12
-------
• As shown in Table 4-10, of the program-level pollutants of interest, S4MO had the
highest daily average concentration of arsenic (PMi0) and the third highest
concentration of manganese (PMio). In addition, the following pollutants for S4MO
were among the 10 highest average concentrations for all NATTS and UATMP sites,
as shown in Tables 4-9 and 4-11: acetaldehyde, acrolein, formaldehyde, and
p-di chl orob enzene.
• Most of the concentrations of the pollutants of interest for S4MO did not vary
significantly by season. However, formaldehyde concentrations were highest in the
summer and lowest in the winter. Also, acetaldehyde concentrations were lowest in
the winter and highest in the summer and fall.
17.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one ore more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. S4MO has sampled carbonyls under the UATMP and/or NATTS
since 2002 and VOC and metals since 2003. Figures 17-5 through 17-8 present the three-year
rolling statistical metrics graphically for arsenic, benzene, 1,3-butadiene, and formaldehyde for
S4MO, respectively. The statistical metrics presented for calculating trends include the
substitution of zeros for non-detects.
Observations from Figure 17-5 for arsenic include the following:
• The maximum arsenic concentration was measured in 2007, as shown for the 2005-
2007 time frame.
• The central tendency shows little variability, as indicated by the closeness of the first
and third quartiles, the median, and the average concentrations.
• The average concentration is very similar to the third quartile for each time period
shown. Given that the third quartile represents the value below which 75 percent of
concentrations fall below, the average concentration shown for each period was
influenced by the outliers, such as the maximum concentrations shown for each
period.
• The rolling average concentrations of arsenic have changed little over the time
periods shown.
• All arsenic concentrations reported to AQS over the five years of sampling were
measured detections.
17-13
-------
Figure 17-5. Three-Year Rolling Statistical Metrics for Arsenic Concentrations Measured at S4MO
50.00 -i
5.00 -
D.OO -
g 30.00
I1
a
| 25.00
a
01
CJ
a
o
U
15.00 -
10.00 -
5.00 -
2003-2005
2004-2006
Three- Year Period
2005-2007
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 17-6. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at S4MO
3.00 i
2.50 -
2.00 -
.o
o.
o.
=
o
'•§ 1.50 -
=
01
-------
Figure 17-7. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at S4MO
n AS.
n zin
n Q^
st n in
c.
c.
^^
=
o
'£ 0 9S
1
"3
0>
o n 9n
y u-zu
n i s
n in
n PK
n nn
•
<
ffifflffi
•
ml
*
•
2003-2005
2004-2006
Three-Year Period
2005-2007
IstQuartile —Minimum "Median —Maximum O Average • 3rd Quartile
-------
Figure 17-8. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at S4MO
40.00 i
35.00
3.00
25.00
c.
a.
a
o
•-g 20.00
15.00
10.00
5.00
0.00
T
ft
2002-2004 2003-2005 2004-2006
Three-Year Period
2005-2007
IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Observations from Figure 17-6 for benzene include the following:
• The maximum benzene concentration shown was measured in 2003, as shown by the
2003-2005 time frame. The maximum concentrations for the remaining time frames
were nearly half of the maximum concentration from 2003-2005.
• The median and rolling average concentrations have a decreasing trend over the time
periods shown.
• All benzene concentrations reported to AQS over the five years of sampling were
measured detections. The decreasing MDL is shown by the decreasing minimum
concentration over the periods.
Observations from Figure 17-7 for 1,3-butadiene include the following:
• Figure 17-7 for 1,3-butadiene is similar to plots of 1,3-butadiene for other program
sites.
• The minimum, first quartile, and median concentrations for 1,3-butadiene were all
zero for the 2003-2005 time frame. As the MDL for 1,3-butadiene improved (i.e,
decreased), the detection rate for this pollutant increased, and a larger spread between
these metrics is observed. This pollutant was detected in 44 percent of samples
during the 2003-2005 time frame; 61 percent of samples during 2004-2006; and 82
percent of samples during 2005-2007.
• The rolling average concentrations shown for all time frames changed little across
each period.
Observations from Figure 17-8 for formaldehyde include the following:
• The maximum formaldehyde concentration shown was measured in 2004, and
appears in Figure 17-8 for the all time frames shown, except the most recent (2005-
2007).
• The median and rolling average concentrations were fairly similar to each other for
each period, indicating rather low variability in central tendency since sampling
began in 2002.
• Both the median and average concentrations exhibited a slight decreasing trend.
• All formaldehyde concentrations reported to AQS over the six years of sampling were
measured detections.
17-18
-------
17.5 Pearson Correlations
Table 17-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for S4MO from Table 17-6 include the following:
• Most of the correlations between the pollutants of interest for S4MO were weak.
• The exceptions include the strong positive correlations calculated between
formaldehyde and the temperature and moisture parameters (except relative
humidity). This indicates that as temperature and moisture content increase,
concentrations of formaldehyde also increase.
• Formaldehyde and acetaldehyde both exhibited strong negative correlations with
wind speed. In addition, all but one of the pollutants of interest exhibited negative
correlations with wind speed, suggesting that concentrations of the pollutants of
interest may increase as wind speeds decrease.
17.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
17.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Missouri
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 17-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk factors.
17-19
-------
Table 17-6. Pearson Correlations Between Selected Meteorological Parameters and Pollutants of Interest for the Missouri
Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
St. Louis, Missouri - S4MO
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Cadmium (PM10)
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (PM10)
Tetrachloroethylene
60
60
60
61
59
60
61
57
60
60
60
0.37
0.29
-0.14
0.11
0.02
0.14
0.20
0.40
0.79
-0.08
0.21
0.29
0.28
-0.17
0.04
-0.06
0.09
0.24
0.38
0.78
-0.17
0.14
0.24
0.25
-0.14
0.01
-0.09
0.05
0.28
0.29
0.73
-0.25
0.10
0.27
0.28
-0.16
0.02
-0.08
0.07
0.26
0.33
0.76
-0.21
0.12
-0.13
-0.17
0.12
-0.03
-0.03
-0.10
0.22
-0.24
-0.14
-0.29
-0.08
-0.02
-0.34
-0.02
0.01
0.08
-0.14
-0.21
-0.20
-0.27
0.29
-0.06
-0.56
-0.09
-0.16
-0.41
-0.45
-0.16
0.01
-0.31
-0.58
-0.24
-0.42
to
o
-------
Table 17-7. MRL Risk Screening Assessment Summary for the Missouri Monitoring Site
Site
S4MO
Method
TO-15
Pollutant
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
#of
Exceedances/
#of
Measured
Detections
0/60
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
Winter
Average
(Ug/m3)
0.49
±0.13
Spring
Average
(Ug/m3)
0.86
±0.27
Summer
Average
(Ug/m3)
0.99
±0.26
Autumn
Average
(Ug/m3)
0.73
±0.20
ATSDR
Chronic
MRL
(Ug/m3)
-
Annual
Average1
(Ug/m3)
0.78
±0.12
BOLD = EPA-designated NATTS Site
BOLD = exceedance of the intermediate or chronic MRL
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
-------
Observations about acrolein in Table 17-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• Each of the seasonal averages of acrolein exceeded the intermediate MRL.
• Acrolein has no chronic MRL. Therefore, a chronic risk comparison could not be
conducted.
17.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen for the Missouri monitoring site and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 17-8. The
data from NATA are presented for the census tract where the monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for S4MO is as follows:
• The census tract for S4MO is 29510126700.
• The population for this census tract was 1,997, which represented less than 0.1
percent of the St. Louis City/County population in 2000.
Observations for S4MO from Table 17-8 include the following:
• The pollutants with the highest concentrations according to NATA were
dichloromethane, benzene, and acetaldehyde.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadiene, and acetaldehyde.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (12.81).
17-22
-------
Table 17-8. Cancer and Noncancer Risk Summary for the Monitoring Site in Missouri
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk (HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
St. Louis, Missouri (S4MO) - Census Tract ID 29510126700
Acetaldehyde
Acrolein
Acrylonitrile
Arsenic (PM10)
Benzene
1,3-Butadiene
Cadmium (PM10)
Carbon Tetrachloride
p-Dichlorobenzene
Dichloromethane
Formaldehyde
Hexavalent Chromium
Manganese (PM10)
Nickel (PM10)
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Trichloroethylene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.0018
0.000015
0.000011
0.00000047
5.5E-09
0.012
~
0.00016
0.000058
0.000005
0.000002
0.009
0.00002
0.002
0.00003
0.03
0.002
0.00002
0.04
0.8
1
0.0098
0.0001
0.00005
0.000065
~
0.27
0.6
2.42
0.26
0.01
0.01
2.61
0.25
O.01
0.21
0.29
4.53
2.29
0.01
0.03
O.01
0.05
0.26
0.31
5.35
—
0.31
0.48
20.38
7.55
3.61
3.16
3.24
2.14
0.01
3.16
~
0.25
3.14
1.54
0.62
0.27
12.81
0.01
0.01
0.08
0.12
0.10
0.01
0.01
0.01
0.23
0.01
0.51
0.02
~
O.01
0.01
4.06 ±0.52
0.78 ±0.12
0.03 ±0.01
0.01 ±0.01
0.83 ±0.14
0.09 ±0.02
O.01±O.01
0.58 ±0.03
0.25 ±0.10
0.50 ±0.12
4.57 ±0.68
0.01 ±0.01
0.01 ±O.01
O.01±O.01
0.06 ±O.01
0.20 ±0.04
0.10 ±0.02
8.11
—
2.29
7.86
5.83
2.78
1.31
8.65
2.70
0.24
0.03
0.41
~
0.23
3.21
0.99
0.21
0.45
38.80
0.02
0.06
0.03
0.05
0.04
0.01
0.01
0.01
0.47
0.01
0.25
0.02
~
O.01
0.01
to
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
• The pollutants with the highest annual averages were formaldehyde, acetaldehyde,
and benzene.
• The pollutants with the highest cancer risk approximations were carbon tetrachloride,
acetaldehyde, and arsenic.
• Similar to the NATA results, acrolein was the only pollutant with a noncancer risk
approximation greater than 1.0 (38.80).
17.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 17-9 and 17-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 17-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 17-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on the site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 17.3, S4MO sampled for VOC,
carbonyls, metals (PMio), and hexavalent chromium. In addition, the cancer and noncancer
surrogate risk approximations are limited to those sites sampling for a long enough period for
annual averages to be calculated.
Observations from Table 17-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in St. Louis.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
cancer UREs) were benzene, 1,3-butadiene, and hexavalent chromium..
17-24
-------
Table 17-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Missouri
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
St. Louis, Missouri (S4MO) - St. Louis City
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Trichloroethylene
Tetrachloroethylene
Dichloromethane
Naphthalene
POM, Group 2
Nickel, PM
253.77
158.58
62.08
29.85
27.59
18.27
13.23
7.49
1.02
0.70
Benzene
1,3 -Butadiene
Hexavalent Chromium
Arsenic, PM
Hydrazine
Naphthalene
Acetaldehyde
Nickel, PM
Tetrachloroethylene
POM, Group 2
1.98E-03
8.96E-04
3.70E-04
3.69E-04
3.19E-04
2.55E-04
1.37E-04
1.12E-04
1.08E-04
5.62E-05
Carbon Tetrachloride
Acetaldehyde
Arsenic
Benzene
1 , 1 ,2,2-Tetrachloroethane
1,3 -Butadiene
£>-Dichlorobenzene
Acrylonitrile
Cadmium
Tetrachloroethylene
8.65
8.11
7.86
5.83
3.22
2.78
2.70
2.27
1.31
0.99
-------
Table 17-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Missouri
to
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximation
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
St. Louis, Missouri (S4MO) - St. Louis City
Toluene
Xylenes
Methanol
Hydrochloric acid
Methyl fer/-butyl ether
Ethylene glycol
Benzene
Formaldehyde
Methyl isobutyl ketone
Ethylbenzene
688.47
452.54
445.38
348.66
320.40
254.80
253.77
158.58
142.85
92.04
Acrolein
Chlorine
Hydrochloric acid
Formaldehyde
1,3 -Butadiene
Nickel, PM
Maleic anhydride
Benzene
Acetaldehyde
Manganese, PM
375,570.89
23,771.26
17,432.98
16,181.60
14,925.25
10,794.77
9,645.64
8,459.05
6,898.31
5,314.87
Acrolein
Formaldehyde
Acetaldehyde
Manganese
Arsenic
1,3 -Butadiene
Cadmium
Benzene
Nickel
Acrylonitrile
38.80
0.47
0.45
0.25
0.06
0.05
0.04
0.03
0.02
0.02
-------
• Seven of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Carbon tetrachloride was the pollutant with the highest cancer surrogate risk
approximation, yet appeared on neither emissions-based list.
• Four of the 10 pollutants with the highest cancer risk approximations, also appear on
both emissions-based lists (acetaldehyde, benzene, 1,3-butadiene, and
tetrachl oroethy 1 ene).
Observations from Table 17-10 include the following:
• Toluene, xylenes, and methanol were the highest emitted pollutants with noncancer
RfCs in St. Louis.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, chlorine, and hydrochloric acid.
• Three of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Acrolein, which had the highest noncancer risk approximation, also had the highest
toxicity-weighted emissions.
• Formaldehyde and benzene appeared on all three lists.
17.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest for S4MO were acetaldehyde, acrolein, arsenic, benzene,
1,3-butadiene, cadmium, carbon tetrachloride, formaldehyde, manganese,
p-dichlorobenzene, and tetrachloroethylene.
»«» Formaldehyde had the highest daily average concentration for S4MO.
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmark.
17-27
-------
18.0 Sites in New Jersey
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at UATMP sites in New Jersey, and integrates these concentrations
with emissions, meteorological, and risk information.
18.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. The New Jersey sites are
located in several different urban areas. CFINJ, ELNJ, and NBNJ are located in the New York-
Northern New Jersey-Long Island, NY-NJ-PA MSA. CANJ is located in the Philadelphia-
Camden-Wilmington, PA-NJ-DE-MD MSA. Figures 18-1 through 18-4 are composite satellite
images retrieved from Google™ Maps showing the monitoring sites in their urban and rural
locations. Figures 18-5 through 18-7 identify point source emission locations within 10 miles of
each site as reported in the 2002 NEI for point sources. Table 18-1 describes the area
surrounding each monitoring site and provides supplemental geographical information such as
land use, location setting, and locational coordinates.
CANJ is located in Camden, which lies just across the Pennsylvania/New Jersey border
and Delaware River, east of Philadelphia. Figure 18-1 shows that the monitoring site is located
at Whitman Park Field, near the intersection of Davis Street and Copewood Street. The areas
west and south of CANJ are residential, while commercial areas are located to the north and east.
Heavily traveled roadways, including 1-676, are located less than a mile from the monitoring site
and a railroad lies less than a half mile from the site. As Figure 18-5 shows, CANJ is located
within 10 miles of a number of point sources. Most of the emission sources are located across
the border in Pennsylvania. The source category with the largest number of emission sources
surrounding CANJ is fuel combustion processes, although there are a number of liquids
distribution and surface coating facilities nearby as well.
CFINJ is located in northern New Jersey, west of the New York City metropolitan area.
Figure 18-2 shows that CFINJ is located in an open area near Building 1 on the property of Bell
18-1
-------
Figure 18-1. Camden, New Jersey (CANJ) Monitoring Site
oo
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 18-2. Chester, New Jersey (CHNJ) Monitoring Site
oo
•Biti
F'
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 18-3. Elizabeth, New Jersey (ELNJ) Monitoring Site
oo
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 18-4. New Brunswick, New Jersey (NBNJ) Monitoring Site
oo
Rutgers
ook-Douglass
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 18-5. NEI Point Sources Located Within 10 Miles of CANJ
Montgomery \
' County \
'
Note: Due to facility density and collocation, the total facilities
displayed may not represent all facilities within the area of interest.
Legend
"fr CANJ UATMP site •".' 10 mile radius ~] County boundary
Source Category Group {No. Of Facilities) Motor Freight Transportation & Warehousing (1)
* Agricultural Chemicals Production Industrial Facility (1) * Non-ferrous Metals Processing Industrial Facility (4)
¥ Automotive Repair, Services, & Parking (1)
: Business Services Facility (1)
c Chemicals & Allied Products Facility (7)
z Electrical & Electronic Equipment Facility (1)
D Fabricated Metal Products Facility (3)
F Fuel Combustion Industrial Facility (64)
I Incineration Industrial Facility (3)
• • Instruments & Related Products Facility (1)
L Liquids Distribution Industrial Facility (11)
X Miscellaneous Manufacturing Industries (3)
P Miscellaneous Processes Industrial Facility (12)
2 Nonmetallic Minerals, Except Fuels (1)
P Petroleum/Nat. Gas Prod. & Refining Industrial Facility (3)
v Polymers & Resins Production Industrial Facility (1)
Q Primary Metal Industries Facility (2)
# Production of Inorganic Chemicals Industrial Facility (1)
4 Production of Organic Chemicals Industrial Facility (6)
:: Pulp & Paper Production Facility (1)
S Surface Coating Processes Industrial Facility (9)
s Utility Boilers (7)
i Vtoste Treatment S Disposal Industrial Facility (2)
r Wholesale Trade (1)
18-6
-------
Figure 18-6. NEI Point Sources Located Within 10 Miles of CHNJ
74°35'Q-W . 4'J j, i rw
Note: Due to facility density and collocation, the total facilities
displayed may not represent all facilities within the area of interest.
Legend
"& CHNJ UATMP site
O 10 mile radius
~~\ County boundary
Source Category Group (No. of Facilities)
c Chemicals & Allied Products Facility (1)
F Fuel Combustion Industrial Facility (1)
•J Industrial Machinery & Equipment Facility (1)
P Miscellaneous Processes Industrial Facility (1)
•' National Security & International Affairs (1)
Q Primary Metal Industries Facility (1)
4 Production of Organic Chemicals Industrial Facility (1)
:r Waste Treatment & Disposal Industrial Facility (1)
18-7
-------
Figure 18-7. NEI Point Sources Located Within 10 Miles of ELNJ and NBNJ
Legend
•& ELNJ UATMP site
-
NENJUATMP site
Source Category Group (No, of Facilities)
t Agricultural Chemicals Production Industrial Facility (2)
- Business Services Facility (2)
C Chemicals & Allied Products Facility (31)
E Electric, Gas, & Sanitary Services (1)
D Fabricated Metal Products Facility (10)
K Ferrous Metals Processing industrial Facility (2)
F Fuel Combustion Industrial Facility (45)
I Incineration Industrial Facility {3}
J Industrial Machinery & Equipment Facility (3)
•= Instruments & Related Products Facility (1)
i- Integrated Iron & Steel Manufacturing Facility (1)
Leather & Leather Products Facility (2)
L Liquids Distribution Industrial Facility (22)
x Metal Mining (1)
B Mineral Products Processing Industrial Facility (6)
X Miscellaneous Manufacturing Industries (1)
irw ' • i A '
tote. DIM to f*0M» denWj «vd colocttkin. rh* tctil liciMwi
ipbytd may not itfinHt ai hdliiin «tnin DM ma at nt«it
10 rnUe radius j County boundary
P Miscellaneous Fr&cesses Industrial Facifciy (29)
\ Mon-fsirous Meiahs Processing Industrial Facility (1)
P PstroteumVNat Gas Plod. 6 Refining (nrtetnal Facility (3)
> Pharmaceutical Production Processes Industrial Facility (8)
v Polymers S Resins Production Industrial Facility (5)
Q Primary Metal Industries Facility (6)
4 Production of Organic Chemicals Industrial Facility (8)
;: Pulp S Paper Production Facility (2)
Y Rubber & Miscellaneous Plastic Products Facility (5)
u Stone. Clay, Glass, S Concrete Products (1)
s Surface Coating Processes Industrial Facility (15)
T Transportation Equipment (1)
41 Transportation by Air (1)
S Utility Boilers (6)
1 Waste Treatment & Disposal Industrial Facility (8)
r Wholesale Trade (3)
18-8
-------
Table 18-1. Geographical Information for the New Jersey Monitoring Sites
Site
Code
CANJ
CHNJ
ELNJ
NBNJ
AQS Code
34-007-0003
34-027-3001
34-039-0004
34-023-0006
Location
Camden
Chester
Elizabeth
New
Brunswick
County
Camden
Morris
Union
Middlesex
Micro- or
Metropolitan
Statistical Area
Philadelphia-
Camden-
Wilmington, PA-
NJ-DE-MD
New York-
Northern New
Jersey -Long
Island, NY-NJ-PA
New York-
Northern New
Jersey-Long
Island, NY-NJ-PA
New York-
Northern New
Jersey-Long
Island, NY-NJ-PA
Latitude
and
Longitude
39.92304,
-75.09762
40.78763,
-74 6763
40.64144,
-74.20836
40.47279,
-74.42251
Land Use
Residential
Agricultural
Industrial
Agricultural
Location
Setting
Suburban
Rural
Suburban
Rural
Description of the
Immediate Surroundings
Although this monitoring site in Camden, NJ, is in a
residential area, numerous industrial facilities and
busy roadways are located within a 10 mile radius.
The monitors are situated in a parking lot of a
business complex.
The Chester, NJ, site is located in a rural-agricultural,
residential section and is topographically rolling.
The site is located near Lucent Laboratory Building
#1. There is potential population exposure to ozone,
NO2, and SO2.
The Elizabeth site is located in Union County, NJ, at
an urban-industrial site where the topography is
relatively smooth. The monitoring site is located
75 yards away from the Toll Plaza and about one
mile from Bay way Refinery. The neighborhood
scale is at maximum concentration. The location has
a PM10 filter analyzer for sulfates and nitrates as well
as the UATMP site.
The New Brunswick site is located in a suburban-
agricultural, residential area and is topographically
smooth. The actual site location is in Rutgers
University's Horticultural Farm.
oo
-------
Labs, which is owned by Alcatel-Lucent. The surrounding area is rural and agricultural with a
rolling topography, but surrounded by small neighborhoods. Although the location is considered
part of the New York City MSA, the site's location is clearly outside most of the urbanized
areas. As Figure 18-6 shows, only eight emission sources are located nearby, most of which lie
just within the 10 mile radius from the site.
ELNJ is located in the city of Elizabeth, New Jersey, which lies just south of Newark and
west of Newark Bay and Staten Island, New York. As Figure 18-3 shows, the monitoring site is
located just off Exit 13 of the New Jersey Turnpike (1-95), near the toll plaza. Interstate 278
intersects the Turnpike here as well. The surrounding area is highly industrialized, with the
Bayway oil refinery located just southwest of the site. However, residential neighborhoods are
located to the northwest of the site. As Figure 18-7 shows, the majority of emission sources in
the vicinity are involved in fuel combustion processes, chemical and allied products production,
and liquid distribution. The emission sources closest to the site, which are partially covered by
the star marker for ELNJ, are involved in organic chemical production, petroleum and natural
gas production and refining, and liquids distribution.
NBNJ is located in New Brunswick, about 20 miles southwest of Elizabeth. The
monitoring site is located on the property of Rutgers University's Cook-Douglass campus, on a
horticultural farm. The surrounding area is agricultural and rural, although residential
neighborhoods are located to the east, across a branch of the Raritan River, as shown in
Figure 18-4. US-1 and State Highway 617 intersect just west of the site. Figure 18-7 shows that
the outer portions of NBNJ and ELNJ's 10 mile radii intersect. The emission source in closest
proximity to the NBNJ monitoring site is involved in pharmaceutical production processes.
Table 18-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the New
Jersey monitoring sites. County-level vehicle registration data for Union, Morris, Camden, and
Middlesex Counties were not available from the State of New Jersey. Thus, state-level vehicle
registration, which was obtained from the Energy Information Administration (EIA), was
18-10
-------
Table 18-2. Population, Motor Vehicle, and Traffic Information for the New Jersey
Monitoring Sites
Site
CANJ
CHNJ
ELNJ
NBNJ
2007
Estimated
County
Population
513,769
488,475
524,658
788,629
Number
of
Vehicles
Registered
371,045
353,934
381,155
564,799
Vehicles
per Person
(Registration:
Population)
0.69
0.69
0.69
0.69
Population
Within
10 Miles
2,003,209
242,969
2,183,873
788,786
Estimated
10-mile
Vehicle
Ownership
1,374,075
166,661
1,497,998
541,057
Annual
Average
Traffic
Data1
4,633
18,360
200,000
63,326
VMT
(thousands)
106,558
299,706
299,706
299,706
1 Daily Average Traffic Data reflects 2005/2007 data from the New Jersey DOT (CANJ), 2005 data from the New
Jersey DOT (CHNJ), data from the New Jersey Turnpike webpage (ELNJ), and 2005 data from the New Jersey
DOT (NBNJ)
allocated to the county level using the county-level proportion of the state population. County-
level population information in these counties was obtained from the U.S. Census Bureau. Table
18-2 also includes a vehicle registration to county population ratio (vehicles per person). In
addition, the population within 10 miles of each site is presented. An estimate of 10-mile vehicle
registration was calculated by applying the county-level vehicle registration to population ratio to
the 10-mile population surrounding the monitoring site. Table 18-2 also contains annual average
daily traffic information, as well as the year of the traffic data estimate and the source from
which it was obtained. Finally, Table 18-2 presents the daily VMT for each urban area.
Observations from Table 18-2 include the following:
• Middlesex County, where NBNJ is located, had the highest county population of the
New Jersey sites. But ELNJ had the highest 10-mile population among the New
Jersey sites.
• Compared to monitoring sites in other locations, the county-level populations were in
the middle of the range. However, ELNJ had the third highest 10-mile population,
behind only BXNY and CELA. CANJ had the fifth highest 10-mile population. The
other program sites' 10-mile populations were in the middle of the range.
• The estimated county-level vehicle ownership values were fairly similar across the
New Jersey sites. The registration estimates were in the middle of the range
compared to other program sites.
• Compared to other program sites, ELNJ had the second highest 10-mile vehicle
ownership estimate, behind only CELA, while CANJ had the fourth highest 10-mile
population.
18-11
-------
• Of the New Jersey sites, ELNJ experienced a significantly higher average traffic
volume than the other program sites, while CANJ experienced the least. Traffic data
for ELNJ were obtained from 1-95, between Exit 11 and 14; traffic data for CANJ
were obtained from Sheridan Street between Norris Street and Pershing Street; traffic
data for CHNJ were obtained from Main Street between Collis Lane and Oakdale
Road; and traffic data for NBNJ were obtained from US-1 near State Road 617
(Ryders Lane).
• VMT for the New York City metropolis ranked first among all urban areas with
UATMP or NATTS sites (and among all U.S. urban areas). The VMT for the
Philadelphia area ranked sixth.
18.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in New Jersey on sampling days, as well as over the course of the year.
18.2.1 Climate Summary
Frontal systems push across New Jersey fairly regularly, producing variable weather.
However, the state's proximity to the Atlantic Ocean has a moderating effect on temperature.
Summers along the coast tend to be cooler than areas farther inland, while winters tend to be
warmer. New Jersey's mid-Atlantic location also allows for ample annual precipitation and high
humidity. A southwesterly wind is most common in the summer and a northwesterly wind is
typical in the winter (Ruffner and Bair, 1987).
18.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The three
closest NWS weather stations are located at Philadelphia International (near CANJ), Somerville-
Somerset Airport (near CHNJ and NBNJ), and Newark International Airport (near ELNJ),
WBAN 13739, 54785, and 14734, respectively.
18-12
-------
Table 18-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 18-3 is the 95 percent
confidence interval for each parameter. As shown in Table 18-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
18.2.3 Composite Back Trajectories for Sampling Days
Figures 18-8 through 18-11 are composite back trajectory maps for the New Jersey
monitoring sites for the days on which samples were collected. Each line represents the 24-hour
trajectory along which a parcel of air traveled toward the monitoring site on a sampling day.
Each concentric circle around the sites in Figures 18-8 through 18-11 represents 100 miles.
Observations from Figures 18-8 through 18-11 include the following:
• Due to their fairly close proximity to each other and standardization of sampling days,
the composite trajectories for the New Jersey sites are fairly similar to each other.
• Back trajectories originated from a variety of directions at the sites, although less
frequently from the east and southeast. The predominant direction of trajectory origin
was from the southwest and northwest.
• The 24-hour air shed domains were somewhat larger for these sites than for other
monitoring sites. The furthest away a trajectory originated was the Gulf of St.
Lawrence, north of New Brunswick, Canada, or nearly 800 miles away. However,
most trajectories originated within 500 miles of the sites.
18.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations at the Philadelphia International (for CANJ),
Somerville-Somerset (for CHNJ and NBNJ), and Newark International Airports (for ELNJ) were
uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce customized
wind roses. A wind rose shows the frequency of wind directions on a 16-point compass, and
uses different shading to represent wind speeds. Figures 18-12 through 18-15 are the wind roses
for the New Jersey monitoring sites on days that samples were collected.
18-13
-------
Table 18-3. Average Meteorological Conditions near the New Jersey Monitoring Sites
Site
CANJ
CHNJ
ELNJ
NBNJ
Closest NWS
Station and
WBAN
Philadelphia
Intl Airport
13739
Somerville,
New Jersey/
Somerset
Airport
54785
Newark
International
Airport
14734
Somerville,
New Jersey/
Somerset
Airport
54785
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
64.75
±4.93
64.25
±2.02
63.15
±4.93
62.95
±2.02
63.34
±4.92
62.98
±1.99
64.46
±4.67
62.95
±2.02
Average
Temperature
(op)
57.11
±4.63
56.31
± 1.85
53.24
±4.56
52.73
± 1.81
55.85
±4.66
55.30
±1.86
54.49
±4.33
52.73
±1.81
Average
Dew Point
Temperature
(°F)
43.56
±5.06
42.00
±2.00
42.07
±4.88
41.01
±2.00
41.66
±4.89
39.99
±1.97
43.46
±4.68
41.01
±2.00
Average
Wet Bulb
Temperature
(°F)
50.61
±4.30
49.51
±1.69
47.95
±4.28
47.30
±1.71
49.09
±4.22
48.12
±1.67
49.18
±4.09
47.30
±1.71
Average
Relative
Humidity
(%)
63.74
±3.62
62.15
± 1.52
69.55
±3.45
68.26
± 1.41
61.82
±3.47
59.55
±1.46
70.00
±3.35
68.26
±1.41
Average
Sea Level
Pressure
(mb)
1017.93
±1.70
1017.60
±0.74
1017.59
±1.61
1016.73
±0.75
1017.47
± 1.64
1016.90
±0.76
1017.15
±1.55
1016.73
±0.75
Average
Scalar Wind
Speed
(kt)
7.77
±0.82
8.15
±0.33
3.00
±0.56
3.38
±0.24
8.13
±0.82
8.51
±0.33
3.00
±0.54
3.38
±0.24
oo
-------
Figure 18-8. Composite Back Trajectory Map for CANJ
00
-------
Figure 18-9. Composite Back Trajectory Map for CHNJ
00
-------
Figure 18-10. Composite Back Trajectory Map for ELNJ
00
0 50 100 200 300 400
Mites
-------
Figure 18-11. Composite Back Trajectory Map for NBNJ
00
00
0 50 100 200 300 400
Miles
-------
Figure 18-12. Wind Rose for CANJ Sampling Days
WEST
Figure 18-13. Wind Rose for CHNJ Sampling Days
1 0%
8%,
6%.
SOUTH--'
EAST
WIND SPEED
(Knots)
^| 17 - 21
^| 11 - 17
i : <-71
• 2- 4
Calms: 57.79%
18-19
-------
Figure 18-14. Wind Rose for ELNJ Sampling Days
NORTH"---.
1 5%
Figure 18-15. Wind Rose for NBNJ Sampling Days
'WEST
18-20
-------
Observations from Figure 18-12 for CANJ include the following:
• Winds from a variety of directions were observed near CANJ, although infrequently
from the southeast. Southerly, southwesterly, and westerly winds were frequently
recorded.
• The wind rose shows that calm winds were observed for less than seven percent of
observations.
• Wind speeds greater than 11 knots were observed for nearly 20 percent of
observations, and were most frequently observed with westerly and northwesterly
winds.
Observations from Figures 18-13 and 18-15 for CFDSTJ and NBNJ include the following:
• The wind roses for CFDSTJ and NBNJ are fairly similar. This is expected given that
the wind data is from the same weather station and the similarity in sampling days
between the sites.
• The wind roses for these sites show that calm winds were observed for nearly 60
percent of observations.
• Northerly and southerly winds were observed more frequently than winds from other
directions.
• Wind speeds greater than 11 knots were observed for less than three percent of
observations.
Observations from Figure 18-14 for ELNJ include the following:
• The wind rose for ELNJ is somewhat similar to the wind rose for CANJ.
• Winds from a variety of directions were observed near ELNJ, although infrequently
from the southeast. Westerly and southwesterly winds were frequently observed near
ELNJ, as were northeasterly winds.
• Calm winds were observed for less than seven percent of observations.
• Wind speeds greater than 11 knots were observed for 21 percent of observations, and
were most frequently observed with westerly and northwesterly winds.
18.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the New
18-21
-------
Jersey monitoring sites were identified using the EPA risk screening process described in
Section 3.2. In brief, each pollutant's measured concentration was compared to its associated
risk screening value. If the daily concentration was greater than the risk screening value, then
the measured concentration "failed the screen." Pollutants of interest are those for which the
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 18-4 presents the pollutants that failed at least one screen for each New Jersey
monitoring site and highlights each site's pollutants of interest (shaded). All four New Jersey
monitoring sites sampled for VOC and carbonyl compounds.
Table 18-4. Comparison of Measured Concentrations and EPA Screening Values for the
New Jersey Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Camden, New Jersey - CANJ
Acetaldehyde
Carbon Tetrachloride
Benzene
Formaldehyde
Acrolein
1,3 -Butadiene
Tetrachloroethylene
p-Dichlorobenzene
Bromomethane
Trichloroethylene
Dichloromethane
Acrylonitrile
1 ,2-Dichloroethane
1 , 1 ,2,2-Tetrachloroethane
Hexachloro- 1 ,3 -butadiene
Total
57
57
57
57
57
55
45
42
14
4
3
2
1
1
1
453
57
57
57
57
57
57
57
57
57
47
57
2
1
1
1
622
100.00
100.00
100.00
100.00
100.00
96.49
78.95
73.68
24.56
8.51
5.26
100.00
100.00
100.00
100.00
72.83
12.58
12.58
12.58
12.58
12.58
12.14
9.93
9.27
3.09
0.88
0.66
0.44
0.22
0.22
0.22
12.58
25.17
37.75
50.33
62.91
75.06
84.99
94.26
97.35
98.23
98.90
99.34
99.56
99.78
100.00
Chester, New Jersey - CHNJ
Acetaldehyde
Formaldehyde
Benzene
Acrolein
Carbon Tetrachloride
1,3 -Butadiene
Tetrachloroethylene
Acrylonitrile
£>-Dichlorobenzene
Hexachloro- 1 ,3 -butadiene
Dichloromethane
Total
54
52
51
51
50
17
14
7
o
6
i
i
302
55
55
52
51
51
38
49
8
30
2
51
442
98.18
94.55
98.08
100.00
98.04
44.74
28.57
87.50
10.00
100.00
1.96
68.33
17.88
17.22
16.89
16.89
16.56
5.63
4.64
2.32
0.99
0.66
0.33
17.88
35.10
51.99
68.87
85.43
91.06
95.70
98.01
99.01
99.67
100.00
18-22
-------
Table 18-4. Comparison of Measured Concentrations and EPA Screening Values for the
New Jersey Monitoring Sites (Continued)
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Elizabeth, New Jersey - ELNJ
Acrolein
Carbon Tetrachloride
Benzene
1,3 -Butadiene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
£>-Dichlorobenzene
Dichloromethane
Acrylonitrile
1 ,2-Dichloroethane
Trichloroethylene
Total
61
61
61
59
56
56
45
32
o
6
i
i
i
437
61
61
61
61
56
56
60
54
61
1
1
38
571
100.00
100.00
100.00
96.72
100.00
100.00
75.00
59.26
4.92
100.00
100.00
2.63
76.53
13.96
13.96
13.96
13.50
12.81
12.81
10.30
7.32
0.69
0.23
0.23
0.23
13.96
27.92
41.88
55.38
68.19
81.01
91.30
98.63
99.31
99.54
99.77
100.00
New Brunswick, New Jersey - NBNJ
Acetaldehyde
Carbon Tetrachloride
Benzene
Acrolein
Formaldehyde
1,3 -Butadiene
Tetrachloroethylene
£>-Dichlorobenzene
Acrylonitrile
Dichloromethane
1 ,2-Dichloroethane
Bromomethane
Total
61
60
60
60
57
40
32
18
4
2
2
1
397
61
60
60
60
61
54
58
51
4
60
4
60
593
100.00
100.00
100.00
100.00
93.44
74.07
55.17
35.29
100.00
3.33
50.00
1.67
66.95
15.37
15.11
15.11
15.11
14.36
10.08
8.06
4.53
1.01
0.50
0.50
0.25
15.37
30.48
45.59
60.71
75.06
85.14
93.20
97.73
98.74
99.24
99.75
100.00
Observations from Table 18-4 include the following:
• Fifteen pollutants failed at least one screen for CANJ; 11 failed screens for CHNJ;
and 12 failed screens for ELNJ and NBNJ.
• The following seven pollutants of interest were common to all sites: acetaldehyde,
acrolein, benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde, and
tetrachl oroethy 1 ene.
• Of the seven common pollutants of interest, 100 percent of the measured detections of
acrolein failed screens for all four sites. If CJTNJ is excluded, benzene, carbon
tetrachloride, and acetaldehyde also failed 100 percent of the screens for the
remaining three sites.
18-23
-------
• The total failure rate ranged from 66.95 percent for NBNJ to 76.53 percent for ELNJ
(of the pollutants with at least one failed screen).
18.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the New Jersey monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the sites, where applicable.
18.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 18-5, where applicable.
Observations for CANJ from Table 18-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (3.78 ± 0.52 |ig/m3), acetaldehyde (2.19 ± 0.22 |ig/m3), and benzene
(1.04±0.14|ig/m3).
• As shown in Tables 4-9 and 4-11, of the program-level pollutants of interest, CANJ
had the ninth highest daily average concentration of formaldehyde, acrolein, and/?-
dichlorobenzene.
• Concentrations of most of the pollutants of interest for CANJ did not vary
significantly from season to season. However, concentrations of formaldehyde were
highest during the summer.
18-24
-------
Table 18-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the New Jersey Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Hg/m3)
Winter
Average
(Hg/m3)
Spring
Average
(Hg/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Ug/m3)
Annual
Average1
(Hg/m3)
Camden, New Jersey - CANJ
Acetaldehyde
Acrolein
Benzene
Bromomethane
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
57
57
57
57
57
57
57
57
57
57
57
57
57
57
57
57
57
57
2.19
±0.22
0.87
±0.18
1.04
±0.14
0.52
±0.22
0.10
±0.02
0.55
±0.04
0.19
±0.03
3.78
±0.52
0.29
±0.04
1.70
±0.29
0.58
±0.25
1.08
±0.31
0.75
±0.62
0.11
±0.02
0.45
±0.10
0.11
±0.03
2.33
±0.28
0.27
±0.08
2.27
±0.40
0.63
±0.17
0.84
±0.16
0.83
±0.53
0.08
±0.01
0.56
±0.09
0.16
±0.05
3.56
±0.66
0.24
±0.05
2.62
±0.42
0.99
±0.20
0.87
±0.15
0.14
±0.06
0.08
±0.02
0.58
±0.08
0.22
±0.05
5.60
±1.18
0.28
±0.06
2.04
±0.48
1.27
±0.60
1.42
±0.36
0.40
±0.26
0.14
±0.06
0.59
±0.05
0.24
±0.07
3.19
±0.70
0.37
±0.10
2.19
±0.22
0.87
±0.18
1.04
±0.14
0.52
±0.22
0.10
±0.02
0.55
±0.04
0.19
±0.03
3.78
±0.52
0.29
±0.04
Chester, New Jersey - CHNJ
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
Tetrachloroethylene
55
51
52
38
51
55
49
55
52
52
52
52
55
52
1.28
±0.12
0.66
±0.17
0.47
±0.06
0.03
±0.01
0.55
±0.05
2.32
±0.51
0.15
±0.03
1.16
±0.15
0.37
±0.14
0.54
±0.14
0.04
±0.02
0.48
±0.08
1.39
±0.20
0.12
±0.02
1.30
±0.24
0.48
±0.12
0.45
±0.12
0.02
±<0.01
0.51
±0.11
1.83
±0.51
0.17
±0.09
1.24
±0.23
1.04
±0.35
0.40
±0.11
0.02
±0.01
0.62
±0.07
2.59
±0.44
0.15
±0.06
1.40
±0.28
0.66
±0.42
0.50
±0.10
0.04
±0.01
0.54
±0.10
3.35
±1.58
0.15
±0.04
1.28
±0.12
NA
NA
NA
NA
2.32
±0.51
NA
NA = completeness was less than 85 percent for VOC for CHNJ
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
18-25
-------
Table 18-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the New Jersey Monitoring Sites (Continued)
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Hg/m3)
Winter
Average
(Hg/m3)
Spring
Average
(Hg/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Ug/m3)
Annual
Average1
(Hg/m3)
Elizabeth, New Jersey - ELNJ
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
56
61
61
61
61
54
56
60
56
61
61
61
61
61
56
61
5.84
±0.88
0.76
±0.13
1.09
±0.18
0.14
±0.02
0.53
±0.04
0.14
±0.03
4.69
±0.65
0.32
±0.05
3.26
±1.04
0.59
±0.19
1.23
±0.23
0.19
±0.06
0.44
±0.10
0.09
±0.03
3.76
±0.76
0.29
±0.09
4.35
±1.03
0.50
±0.13
0.87
±0.20
0.10
±0.02
0.54
±0.10
0.10
±0.04
5.61
±1.17
0.28
±0.08
8.70
±1.41
1.03
±0.35
0.84
±0.17
0.10
±0.02
0.56
±0.08
0.16
±0.06
5.87
± 1.17
0.31
±0.09
6.72
±1.97
0.85
±0.17
1.50
±0.56
0.17
±0.06
0.57
±0.05
0.15
±0.04
2.39
±0.94
0.39
±0.16
5.84
±0.88
0.76
±0.13
1.09
±0.18
0.14
±0.02
0.53
±0.04
0.12
±0.02
4.69
±0.65
0.31
±0.05
New Brunswick, New Jersey - NBNJ
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
61
60
60
54
60
51
61
58
61
60
60
60
60
60
61
60
1.55
±0.18
0.53
±0.09
0.56
±0.08
0.06
±0.01
0.58
±0.04
0.08
±0.01
2.13
±0.30
0.23
±0.04
1.36
±0.22
0.39
±0.09
0.73
±0.26
0.09
±0.05
0.43
±0.09
NR
1.92
±0.34
0.21
±0.09
1.19
±0.28
0.43
±0.16
0.44
±0.07
0.04
±0.01
0.59
±0.05
0.06
±0.02
1.50
±0.29
0.17
±0.04
2.03
±0.37
0.54
±0.09
0.47
±0.07
0.04
±0.01
0.66
±0.06
0.10
±0.02
3.14
±0.69
0.24
±0.06
1.46
±0.28
0.73
±0.26
0.64
±0.16
0.06
±0.02
0.59
±0.07
0.08
±0.02
1.62
±0.29
0.26
±0.11
1.55
±0.18
0.53
±0.09
0.56
±0.08
0.06
±0.01
0.58
±0.04
0.08
±0.01
2.13
±0.30
0.22
±0.04
NA = completeness was less than 85 percent for VOC for CHNJ
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for CHNJ from Table 18-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (2.32 ± 0.51 |ig/m3), acetaldehyde (1.28 ± 0.12 |ig/m3), and acrolein
(0.66±0.17|ig/m3).
18-26
-------
• None of the pollutants of interest for CHNJ appeared in Table 4-9 or Table 4-11,
indicating that the daily averages of these pollutants were not among the 10 highest
concentrations.
• Annual averages were not calculated for VOC at CHNJ. This is because this site did
not meet the 85 percent completeness criteria discussed in Section 2.4.
• Concentrations of most of the pollutants of interest for CHNJ did not vary
significantly from season to season. Concentrations of formaldehyde appear higher
during the summer and fall, but the confidence intervals indicate that the difference
was not significant.
Observations for ELNJ from Table 18-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
acetaldehyde (5.84 ± 0.88 |ig/m3), formaldehyde (4.69 ± 0.65 |ig/m3), and benzene
(1.09 ±0.18 |ig/m3). These averages were the highest among the New Jersey sites.
• As shown in Tables 4-9 and 4-11, of the program-level pollutants of interest, ELNJ
had the second highest daily average concentration of acetaldehyde; the fourth
highest daily average concentration of formaldehyde; and the tenth highest daily
average concentration of benzene.
• Concentrations of most of the pollutants of interest for ELNJ did not vary
significantly from season to season. However, concentrations of acetaldehyde were
highest during the summer and autumn and concentrations of 1,3-butadiene were
highest in autumn and winter.
Observations for NBNJ from Table 18-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (2.13 ± 0.30 |ig/m3), acetaldehyde (1.55 ± 0.18 |ig/m3), and carbon
tetrachloride (0.58 ± 0.04 |ig/m3).
• Similar to CHNJ, none of the pollutants of interest for NBNJ appeared in Table 4-9 or
Table 4-11, indicating that the daily averages of these pollutants were not among the
10 highest concentrations.
• Concentrations of most of the pollutants of interest for NBNJ did not vary
significantly from season to season. However, concentrations of formaldehyde were
highest during the summer.
18-27
-------
18.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. The New Jersey sites have sampled VOC and carbonyls under the
UATMP for many years. CHNJ and NBNJ have sampled since 2001; ELNJ since 2000; and
CANJ since 1994. Figures 18-16 through 18-30 present the three-year rolling statistical metrics
graphically for benzene, 1,3-butadiene, and formaldehyde for each monitoring site. The
statistical metrics presented for calculating trends include the substitution of zeros for non-
detects.
Observations from Figure 18-16 for benzene measurements at CANJ include the
following:
• The maximum benzene concentration shown was measured in 1996 and was more
than twice the next highest maximum concentration (measured in 2001).
• Although the range of concentrations measured varies, the rolling average
concentrations vary between 0.35 and 0.70 ppbv. A slight decreasing trend in the
average and median concentrations is evident beginning around the 1997-1999 time
frame through the last time period.
• One non-detect was recorded in 2002, which explains why the minimum
concentration decreased to zero for three of the time frames shown.
Observations from Figure 18-17 for 1,3-butadiene measurements at CANJ include the
following:
• The highest concentration of 1,3-butadiene was measured in 1994.
• The minimum and first quartile were both zero for all time frames except 2005-2007,
which explains why the "box" rests on the x-axis for most of the plot. The median
decreased to zero for the 2002-2004 and 2003-2005 time frames.
• Even as the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for
this pollutant hovered around 60 percent until 2000-2002, when it decreased for a few
time periods. The detection rate began to increase again in 2004-2006 and was up to
87 percent for the final time frame (2005-2007).
• The median and rolling average concentrations shown became more similar over the
final two periods, which indicates decreasing variability in the central tendency.
18-28
-------
Figure 18-16. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at CANJ
oo
to
VO
3.000
7.000
6.000
5.000
o.
o.
=
I 4.000
=
01
CJ
=
o
u 3.000
2.000
1.000
1994-1996 1995-1997 1996-1998 1997-1999 1998-2000 1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006 2005-2007
Three-Year Period
• IstQuartile —Minimum —Median —Maximum O Average • SrdQuartile
-------
Figure 18-17. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at CANJ
oo
oo
o
0.900 i
0.800 -
0.600 -
O.f
| 0.400
=
o
U
0.2
0.200 -
0.100
0.000
1994-1996 1995-1997 1996-1998 1997-1999 1998-2000 1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006 2005-2007
Three-Year Period
IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 18-18. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at CANJ
45.00
40.00
5.00
5.00
=
.0
*
§ 20.00
CJ
=
o
U
15.00
10.00
0.00
I
1995-1997 1996-1998 1997-1999 1998-2000 1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006 2005-2007
Three- Year Period
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 18-19. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at CHNJ
0.700
oo
oo
to
0.500 -
0.400 -
0.300
0.200 -
0.100
2001-2003
2002-2004
2003-2005
Three-Year Period
2004-2006
2005-2007
IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 18-20. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at CHNJ
u.^uu -
n "} ^n
n ?nn
c.
o.
a
O
*n n i so
JS U.13U
^^
=
01
u
i— > a
00 (j
oo
(>J n i nn -
n nsn -
n nnn -
.,,1
^, , 1
fc,,
•
L: , ^
• •
5n «
•
mi
2001-2003
2002-2004
2003-2005
Three-Year Period
2004-2006
2005-2007
• IstQuartile —Minimum —Median —Maximum O Average • SrdQuartile
-------
Figure 18-21. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at CHNJ
50.00
40.00
oo
oo
ja ju.uu
o.
&
o
o
'•S 25.00
=
01
J 20.00
5.00
10.00
5.00
0.00
2001-2003
2002-2004
2003-2005
Three-Year Period
2004-2006
2005-2007
1 st Quartile — Minimum • - Median — Maximum O Average • 3rd Quartile
-------
Figure 18-22. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at ELNJ
oo
oo
1.80
1.60
1.4(
.o
o.
1.00
§ 0.80
o
U
0.40
0.20
2000-2002 2001-2003 2002-2004 2003-2005
Three-Year Period
2004-2006
2005-2007
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 18-23. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at ELNJ
oo
oo
0.50
0.45 -
0.40 -
0.3
£ 0.30
o.
o.
0.15 -
0.10 -
O.C
0.00
2000-2002 2001-2003 2002-2004 2003-2005
Three-Year Period
2004-2006
2005-2007
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 18-24. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at ELNJ
oo
oo
14.00 -i
12.00
10.00
o.
o.
=
o
3.00
a 6.00
4.00
2.00
2000-2002 2001-2003 2002-2004 2003-2005
Three-Year Period
2004-2006
2005-2007
IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 18-25. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at NBNJ
oo
oo
oo
1.40
1.00 -
=
.o
**^
03
"a
| 0.60 H
o
U
0.4
120 -
0.00
2001-2003
T
2002-2004
2003-2005
Three-Year Period
2004-2006
2005-2007
» 1st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 18-26. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at NBNJ
oo
oo
VO
n 90
> n i <; _
mcentration (ppb
3 C
3 <-
(J U-1>J
n n-^
n nn
•
O
<
• •
0 <
• •
•
1
1
.
> .
1
• '
S. s
2001-2003 2002-2004 2003-2005 2004-2006 2005-2007
Three-Year Period
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 18-27. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at NBNJ
oo
-U
o
90.00 1
80.00
70.00
3.00
=
.0
§ 40.00
=
o
U
10.00
2001-2003
L-tJ
2002-2004
2003-2005
Three- Year Period
2004-2006
2005-2007
• IstQuartile —Minimum —Median —Maximum O Average • SrdQuartile
-------
Observations from Figure 18-18 for formaldehyde measurements at CANJ include the
following:
• The maximum formaldehyde concentration shown was measured in 2004. The seven
highest concentrations of formaldehyde since the onset of sampling were measured in
2004, which explains the increasing difference in the central tendency statistics
(median and average concentrations) during the time periods incorporating
measurements for 2004. The average and median concentration were fairly similar
again for the 2005-2007 time frame.
• Beginning with the 1998-2000 period, a decreasing trend in the average
concentrations was apparent, until the 2002-2004 time frame.
• All formaldehyde concentrations reported to AQS over the thirteen years of sampling
were measured detections.
Observations from Figure 18-19 for benzene measurements at CFDSTJ include the
following:
• The maximum benzene concentration shown was measured in 2001.
• The central tendency of the rolling averages and the median values were similar to
each other for each time period. The "closeness" in these metrics indicates relatively
little variability in the central tendency.
• A slight decreasing trend in the average and median concentrations is evident across
the sampling periods.
• With the exception of the 2001-2003 time frame, a few non-detects were recorded in
each time frame, which may be attributable to co-elution with another pollutant.
Observations from Figure 18-20 for 1,3-butadiene measurements at CHNJ include the
following:
• The maximum 1,3-butadiene concentration shown was measured in 2003.
• However, the minimum, first quartile, third quartile, and median concentrations for
the first three periods were all zero. The averages for these periods were also very
low. This is due to the large number of non-detects.
• As the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for this
pollutant increased. The detection rate increased from eight percent during the first
time frame to 57 percent for the final time frame. This detection rate is still rather
low compared to other monitoring sites.
18-41
-------
• As the detection rate increased, the values for the rolling metrics increased as well.
Observations from Figure 18-21 for formaldehyde measurements at CHNJ include the
following:
• Similar to CANJ, the maximum formaldehyde concentration shown was measured in
2004. This concentration of formaldehyde was nearly four times the maximum
concentrations shown for other periods not including 2004. The second highest
concentration was also measured in 2004, but was nearly half the magnitude.
• However, a slight decrease is shown across the periods for both the rolling average
and median concentrations.
• All formaldehyde concentrations reported to AQS over the seven years of sampling
were measured detections.
Observations from Figure 18-22 for benzene measurements at ELNJ include the
following:
• The maximum benzene concentration shown was measured in 2007. However, this
value is very similar to the highest concentration measured in 2002. As such, the
maximum concentration shown in Figure 18-22 appears the same for the first three
and final time periods.
• The rolling averages and the median values were similar to each other for each time
period. The "closeness" in these metrics indicates relatively little variability in the
central tendency.
• A decreasing trend in the rolling average and median concentrations is evident across
the sampling periods, even though the maximum concentration increased over the
2004-2006 and 2005-2007 time frames.
• With the exception of the first two periods, one non-detect was recorded in each
period.
Observations from Figure 18-23 for 1,3-butadiene measurements at ELNJ include the
following:
• The first quartile decreased to zero over the first three periods, then remained at zero
for the next two periods.
18-42
-------
• Even as the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for
this pollutant decreased for a few periods. The detection rate began to increase in
2004-2006 and was up to 88 percent for the final time frame (2005-2007).
• The rolling average and the median concentrations were similar to each other for each
time period. The "closeness" in these metrics indicates relatively little variability in
the central tendency. In addition, these metrics show a decreasing trend across most
of the periods.
• The highest concentration of 1,3-butadiene was measured in 2001.
Observations from Figure 18-24 for formaldehyde measurements at ELNJ include the
following:
• Although the maximum formaldehyde concentration shown was measured in 2000,
the other metrics, including the rolling average and median concentrations, increased
for each three-year period shown.
• The rolling average and the median values became more similar to each other for
each time period. The improving "closeness" in these metrics indicates decreasing
variability in the central tendency.
• All formaldehyde concentrations reported to AQS over the seven years of sampling
were measured detections.
Observations from Figure 18-25 for benzene measurements at NBNJ include the
following:
• The maximum benzene concentration shown was measured in 2002.
• The rolling averages and the median values were similar to each other for each time
period. The "closeness" in these metrics indicates relatively little variability in the
central tendency.
• A decreasing trend in the average and median concentrations is shown across the
sampling periods.
• A single non-detect was recorded in 2002.
18-43
-------
Observations from Figure 18-26 for 1,3-butadiene measurements atNBNJ include the
following:
• The minimum, first quartile, and median concentrations were zero for 2001-2003,
2003-2005, and 2004-2006 time frames. These metrics as well as the third quartile
were zero for the 2002-2004 time frame. This demonstrates the impact of the zero
substitution for non-detects.
• The detection rate decreased over the 2002-2004 time frame, from 35 percent to 21
percent, then increased during each period following as the MDL for 1,3-butadiene
improved (i.e, decreased).
• The median and rolling average concentrations became more similar to each other
during the final time period, which indicates decreasing variability in the central
tendency.
• The highest concentration of 1,3-butadiene was measured in 2005.
Observations from Figure 18-27 for formaldehyde measurements at NBNJ include the
following:
• Similar to CANJ and CFDSTJ, the maximum formaldehyde concentration shown was
measured in 2004. This concentration of formaldehyde was nearly four times the
maximum concentrations shown for other periods not including 2004.
• For each period shown, the average concentration is more similar to the third quartile
than the median concentration, even for periods not affected by the 2004 maximum
concentration.
• A single non-detect was recorded in 2006.
18.5 Pearson Correlations
Table 18-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
18-44
-------
Table 18-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
New Jersey Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Camden, New Jersey - CANJ
Acetaldehyde
Acrolein
Benzene
Bromomethane
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
57
57
57
57
57
57
57
57
57
0.57
0.29
0.15
-0.09
-0.12
0.33
0.54
0.69
0.09
0.52
0.29
0.14
-0.11
-0.12
0.36
0.52
0.67
0.12
0.40
0.29
0.17
-0.18
-0.04
0.38
0.46
0.54
0.19
0.46
0.29
0.15
-0.15
-0.09
0.37
0.49
0.60
0.15
-0.16
0.11
0.17
-0.26
0.22
0.25
0.08
-0.11
0.30
-0.19
-0.03
-0.16
0.24
-0.06
-0.14
-0.25
-0.29
-0.02
-0.36
0.03
-0.19
0.29
-0.26
-0.01
-0.36
-0.30
-0.44
Chester, New Jersey - CHNJ
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
Tetrachloroethylene
55
51
52
38
51
55
49
0.17
0.39
-0.33
-0.49
0.21
0.29
-0.17
0.11
0.43
-0.33
-0.49
0.24
0.29
-0.18
0.17
0.41
-0.23
-0.32
0.29
0.36
-0.10
0.14
0.43
-0.30
-0.42
0.27
0.33
-0.14
0.25
0.06
0.23
0.46
0.27
0.35
0.19
0.18
-0.29
0.15
0.27
-0.09
-0.07
0.04
-0.45
0.04
-0.37
-0.43
-0.11
-0.29
-0.35
Elizabeth, New Jersey - ELNJ
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
56
61
61
61
61
54
56
60
0.71
0.34
-0.05
-0.26
0.22
0.22
0.36
0.03
0.72
0.36
-0.07
-0.27
0.25
0.25
0.35
0.04
0.67
0.40
0.03
-0.12
0.29
0.35
0.20
0.16
0.70
0.39
-0.02
-0.21
0.27
0.30
0.27
0.09
0.04
0.22
0.29
0.40
0.19
0.32
-0.36
0.37
-0.15
0.00
0.01
0.28
0.06
0.09
-0.16
0.15
-0.39
-0.26
-0.43
-0.46
-0.24
-0.55
-0.11
-0.54
oo
-------
Table 18-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
New Jersey Monitoring Sites (Continued)
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
New Brunswick, New Jersey - NBNJ
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
61
60
60
54
60
51
61
58
0.48
0.19
-0.32
-0.47
0.54
0.19
0.41
-0.07
0.42
0.16
-0.33
-0.46
0.58
0.21
0.40
-0.06
0.42
0.22
-0.17
-0.29
0.62
0.31
0.41
0.10
0.41
0.19
-0.27
-0.40
0.61
0.26
0.41
0.01
0.17
0.23
0.41
0.40
0.39
0.35
0.18
0.48
0.12
-0.09
0.18
0.31
-0.18
0.09
0.00
0.21
-0.51
-0.21
-0.45
-0.42
-0.18
-0.44
-0.37
-0.55
oo
-------
Observations from Table 18-6 include the following:
• The majority of the correlations for the pollutants of interest for the New Jersey sites
and the selected meteorological parameters were weak. There were, however, a few
notable exceptions. Acetaldehyde exhibited strong positive correlations with the
temperature and moisture variables (except relative humidity) for ELNJ, indicating
that concentrations of this pollutant tend to increase as temperature and moisture
content increase. This supports the seasonal average observations from 18.4.1. This
is also true for acetaldehyde and the temperature parameters for CANJ, although the
correlations were not as strong.
• Formaldehyde exhibited strong positive correlations with the temperature and
moisture variables (except relative humidity) for CANJ, indicating that concentrations
of this pollutant tend to increase as temperature and moisture content increase. This
supports the seasonal average observations from 18.4.1. This is also true forp-
dichlorobenzene and the temperature parameters for CANJ, although the correlations
were not as strong.
• Carbon tetrachloride exhibited strong positive correlations with the temperature and
moisture variables for NBNJ, indicating that concentrations of this pollutant tend to
increase as temperature and moisture content increase.
• Weak, moderate, and strong correlations were calculated for the pollutants of interest
and wind speed. However, all but two were negative, indicating a tendency for
increased concentrations with lower wind speeds.
18.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
18.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the New
Jersey monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available.
As described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
18-47
-------
comparisons are summarized in Table 18-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 18-7 include the following:
• None of the preprocessed daily measurements of acrolein from the New Jersey sites
exceeded the acute MRL.
• All four seasonal averages of acrolein exceeded the intermediate MRL for all four
New Jersey sites.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
18.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the New Jersey monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 18-8. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the New Jersey sites is as follows:
• The CANJ monitoring site is located in census tract 34007601500, which had a
population of 6,424, and represented 1.3 percent of the Camden County population in
2000.
• The CJrDSTJ monitoring site is located in census tract 34027045901, which had a
population of 1,635, and represented 0.3 percent of Morris County's 2000 population.
• ELNJ is located in census tract 34039030100. The population in that census tract in
2000 was 334, or less than 0.1 percent of Union County's population.
18-48
-------
Table 18-7. MRL Risk Screening Assessment Summary for the New Jersey Monitoring Sites
Site
CANJ
CHNJ
ELNJ
NBNJ
Method
TO-15
TO-15
TO-15
TO-15
Pollutant
Acrolein
Acrolein
Acrolein
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
7.00
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/57
0/51
0/61
0/60
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
0.09
0.09
0.09
Winter
Average
(Ug/m3)
0.58
±0.25
0.37
±0.14
0.59
±0.19
0.39
±0.09
Spring
Average
(Ug/m3)
0.63
±0.17
0.48
±0.12
0.50
±0.13
0.43
±0.16
Summer
Average
(Ug/m3)
0.99
±0.2
1.04
±0.35
1.03
±0.35
0.54
±0.09
Autumn
Average
(Ug/m3)
1.27
±0.60
0.66
±0.42
0.85
±0.17
0.73
±0.26
ATSDR
Chronic
MRL
(Ug/m3)
—
~
—
~
Annual
Average1
(Ug/m3)
0.87
±0.18
NA
0.76
±0.13
0.53
±0.09
BOLD = exceedance of the intermediate or chronic MRL
~ = an MRL risk factor is not available
NA = completeness was less than 85 percent for VOC for CHNJ
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
^ Program completeness and sampling duration criteria were applied.
VO
-------
Table 18-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in New Jersey
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk (HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Camden, New Jersey (CANJ) - Census Tract ID 34007601500
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
Bromomethane
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
1 ,2-Dichloroethane
Dichloromethane
Formaldehyde
Hexachloro- 1 ,3 -butadiene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Trichloroethylene
0.000002
—
0.000068
0.000007
~
0.00003
0.000015
0.000011
0.000026
0.00000047
5.5E-09
0.000022
0.000058
0.000005
0.000002
0.009
0.00002
0.002
0.03
0.005
0.002
0.04
0.8
2.4
1
0.0098
0.09
~
0.27
0.6
2.49
0.19
0.01
1.90
0.28
0.18
0.22
0.09
0.04
0.77
2.45
0.01
0.05
0.23
0.15
5.50
—
0.06
14.86
~
5.36
3.29
1.00
1.05
0.37
0.01
0.03
3.11
1.38
0.30
0.27
9.63
0.01
0.06
0.05
0.08
0.01
O.01
0.01
0.01
0.24
0.01
~
O.01
O.01
2.19 ±0.22
0.87 ±0.18
0.03 ±0.01
1.04 ±0.14
0.52 ±0.22
0.10 ±0.02
0.55 ±0.04
0.19 ±0.03
0.05 ±0.01
0.61 ±0.23
3.78 ±0.52
0.20 ±0.01
0.05 ± O.01
0.29 ±0.04
0.22 ± 0.06
4.38
—
1.80
7.26
~
3.02
8.20
2.04
1.17
0.29
0.02
4.32
3.17
1.44
0.44
0.24
43.25
0.01
0.03
0.10
0.05
0.01
O.01
0.01
0.01
0.39
0.01
~
O.01
O.01
oo
(!/i
o
Bold = pollutant of interest
NA = completeness was less than 85 percent for VOC for CHNJ
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 18-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in New Jersey (Continued)
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk (HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Chester, New Jersey (CHNJ) - Census Tract ID 34027045901
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Dichloromethane
Formaldehyde
Hexachloro- 1 ,3 -butadiene
Tetrachloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000011
0.00000047
5.5E-09
0.000022
0.000005
0.009
0.00002
0.002
0.03
0.002
0.04
0.8
1
0.0098
0.09
0.27
1.09
0.07
0.01
1.03
0.11
0.21
0.02
0.36
1.29
0.01
0.12
2.42
—
0.02
8.08
3.42
3.11
0.24
0.18
0.01
0.03
0.71
0.12
3.33
0.01
0.03
0.05
0.01
O.01
O.01
0.13
0.01
0.01
1.28 ±0.12
NA
NA
NA
NA
NA
NA
NA
2.32 ±0.51
NA
NA
2.56
NA
NA
NA
NA
NA
NA
NA
0.01
NA
NA
0.14
NA
NA
NA
NA
NA
NA
NA
0.24
NA
NA
oo
Bold = pollutant of interest
NA = completeness was less than 85 percent for VOC for CHNJ
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 18-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in New Jersey (Continued)
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk (HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Elizabeth, New Jersey (ELNJ) - Census Tract ID 34039030100
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
1 ,2-Dichloroethane
Dichloromethane
Formaldehyde
Tetrachloroethylene
Trichloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000011
0.000026
0.00000047
5.5E-09
0.000005
0.000002
0.009
0.00002
0.002
0.03
0.002
0.04
0.8
2.4
1
0.0098
0.27
0.6
4.35
0.71
0.01
3.37
0.54
0.21
0.07
0.03
0.68
4.49
0.31
0.12
9.59
—
0.07
26.33
16.09
3.16
0.72
0.91
0.33
0.03
1.81
0.23
0.48
35.46
0.01
0.11
0.26
0.01
O.01
O.01
0.01
0.57
0.01
0.01
5. 84 ±0.88
0.76 ±0.13
0.03 ±0.01
1.09 ±0.18
0.14 ±0.02
0.53 ±0.04
0.12 ±0.02
0.04 ±O.01
1.04 ±0.45
4.69 ±0.65
0.31 ±0.05
0.10 ±0.02
11.68
—
1.77
7.66
4.18
7.96
1.37
1.10
0.49
0.03
1.57
0.20
0.65
37.80
0.01
0.04
0.07
0.01
O.01
O.01
0.01
0.48
0.01
0.01
oo
(!/i
to
Bold = pollutant of interest
NA = completeness was less than 85 percent for VOC for CHNJ
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 18-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in New Jersey (Continued)
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk (HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
New Brunswick, New Jersey (NBNJ) - Census Tract ID 34023006206
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
Bromomethane
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
1 ,2-Dichloroethane
Dichloromethane
Formaldehyde
Tetrachloroethylene
0.000002
—
0.000068
0.000007
~
0.00003
0.000015
0.000011
0.000026
0.00000047
5.5E-09
0.000005
0.009
0.00002
0.002
0.03
0.005
0.002
0.04
0.8
2.4
1
0.0098
0.27
1.97
0.15
0.01
2.25
0.13
0.28
0.21
0.04
0.04
0.49
2.29
0.20
4.36
—
0.07
17.62
~
8.32
3.17
0.44
0.92
0.23
0.01
1.20
0.22
7.61
0.01
0.07
0.02
0.13
0.01
O.01
0.01
0.01
0.23
0.01
1.55 ±0.18
0.53 ±0.09
0.04 ±0.01
0.56 ±0.08
0.08 ±0.05
0.06 ±0.01
0.58 ±0.04
0.08 ±0.01
0.04 ±0.01
0.59 ±0.19
2.13 ±0.30
0.22 ±0.04
3.11
—
2.40
3.92
~
1.68
8.70
0.84
1.10
0.28
0.01
1.12
0.17
26.51
0.02
0.02
0.02
0.03
0.01
O.01
0.01
0.01
0.22
0.01
oo
Bold = pollutant of interest
NA = completeness was less than 85 percent for VOC for CHNJ
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
• Finally, NBNJ is located in census tract 34023006206. In 2000, the population in this
census tract was 1,794, or 0.2 percent of the Middlesex County population.
Observations from Table 18-8 include the following:
• The pollutants with the highest concentrations for each site according to NATA were
acetaldehyde, formaldehyde, and benzene (although not necessarily in that order).
• The pollutants with the highest cancer risks for each site according to NATA were
benzene, 1,3-butadiene, and acetaldehyde (although not necessarily in that order),
except CHNJ. Benzene, 1,3-butadiene, and carbon tetrachloride were the pollutants
with the highest cancer risk for CHNJ.
• Benzene had the highest cancer risks for each site according to NATA, and ranged
from 8.08 in-a-million (for CHNJ) to 26.33 in-a-million (for ELNJ).
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (ranging from 3.33 for CHNJ to 35.46 for ELNJ).
• The pollutants with the highest 2007 annual averages for CANJ and ELNJ were
benzene, formaldehyde, and acetaldehyde (although not necessarily in that order).
The pollutants with the highest 2007 annual averages for NBNJ were formaldehyde,
acetaldehyde, and carbon tetrachloride.
• Annual averages were not calculated for VOC for CHNJ. This is because this site did
not meet the 85 percent completeness criteria discussed in Section 2.4. Therefore,
cancer and noncancer risk estimates could only be calculated for acetaldehyde and
formaldehyde. The annual average for formaldehyde was nearly twice the annual
average for acetaldehyde.
• The pollutants with the highest surrogate cancer risk approximations were carbon
tetrachloride, benzene, and acetaldehyde for CANJ, ELNJ, and NBNJ (although not
necessarily in that order).
• The only pollutant with a surrogate noncancer risk approximation greater than 1.0
was acrolein (ranging from 26.51 for NBNJ to 43.25 for CANJ).
18.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 18-9 and 18-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 18-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
18-54
-------
Table 18-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in New Jersey
oo
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Camden, New Jersey (CANJ) - Camden County
Benzene
Formaldehyde
Dichloromethane
Tetrachloroethylene
1 ,3 -Dichloropropene
Acetaldehyde
1,3 -Butadiene
/>-Dichlorobenzene
Naphthalene
POM, Group 2
202.20
129.48
54.82
38.54
36.95
33.68
25.38
19.07
18.69
2.86
Benzene
1,3 -Butadiene
Naphthalene
Hexavalent Chromium
Tetrachloroethylene
£>-Dichlorobenzene
POM, Group 2
1 ,3 -Dichloropropene
POM, Group 3
Cadmium, PM
1.58E-03
7.61E-04
6.35E-04
3.32E-04
2.27E-04
2.10E-04
1.57E-04
1.48E-04
8.27E-05
8.20E-05
Carbon Tetrachloride
Benzene
Acetaldehyde
Hexachloro- 1 ,3 -butadiene
1, 1,2,2-Tetrachloroethane
1,3 -Butadiene
£>-Dichlorobenzene
Acrylonitrile
Tetrachloroethylene
1 ,2-Dichloroethane
8.20
7.26
4.38
4.34
3.18
3.02
2.04
1.78
1.44
1.18
Chester, New Jersey (CHNJ) - Morris County
Benzene
Formaldehyde
Dichloromethane
Acetaldehyde
1,3 -Butadiene
1 ,3 -Dichloropropene
Tetrachloroethylene
Naphthalene
£>-Dichlorobenzene
Trichloroethylene
320.42
145.06
55.35
45.85
45.10
34.55
30.12
19.50
17.84
17.27
Benzene
1,3 -Butadiene
Naphthalene
Hexavalent Chromium
Nickel, PM
£>-Dichlorobenzene
Tetrachloroethylene
1 ,3 -Dichloropropene
POM, Group 2
Arsenic, PM
2.50E-03
1.35E-03
6.63E-04
4.47E-04
2.53E-04
.96E-04
.78E-04
.38E-04
.33E-04
.10E-04
Acetaldehyde
Formaldehyde
2.56
0.01
-------
Table 18-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in New Jersey (Continued)
oo
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Elizabeth, New Jersey (ELNJ) - Union County
Benzene
Formaldehyde
Dichloromethane
Tetrachloroethylene
Acetaldehyde
1 ,3 -Dichloropropene
1,3 -Butadiene
Naphthalene
£>-Dichlorobenzene
Trichloroethylene
255.56
120.42
76.41
42.40
40.12
38.31
33.14
20.92
19.80
4.55
Benzene
1,3 -Butadiene
Naphthalene
Nickel, PM
Hexavalent Chromium
Tetrachloroethylene
£>-Dichlorobenzene
Arsenic, PM
Hexavalent Chromium
POM, Group 2
1.99E-03
9.94E-04
7.11E-04
3.56E-04
2.78E-04
2.50E-04
2.18E-04
2.01E-04
1.53E-04
1.49E-04
Acetaldehyde
Carbon Tetrachloride
Benzene
1,3 -Butadiene
Acrylonitrile
Tetrachloroethylene
£>-Dichlorobenzene
1,2-Dichloroethane
Dichloromethane
Trichloroethylene
11.68
7.96
7.66
4.18
1.75
1.57
1.37
1.11
0.49
0.19
New Brunswick, New Jersey (NBNJ) - Middlesex County
Benzene
Formaldehyde
Dichloromethane
Acetaldehyde
Tetrachloroethylene
1,3 -Butadiene
1 ,3 -Dichloropropene
Naphthalene
£>-Dichlorobenzene
Trichloroethylene
414.77
221.09
108.90
75.01
59.93
56.56
55.98
32.23
28.93
7.53
Benzene
1,3 -Butadiene
Naphthalene
Hexavalent Chromium
Tetrachloroethylene
£>-Dichlorobenzene
POM, Group 2
1 ,3 -Dichloropropene
Acetaldehyde
Arsenic, PM
3.24E-03
1.70E-03
1.10E-03
4.57E-04
3.54E-04
3.18E-04
2.29E-04
2.24E-04
1.65E-04
1.40E-04
Carbon Tetrachloride
Benzene
Acetaldehyde
Acrylonitrile
1,3 -Butadiene
Tetrachloroethylene
1 ,2-Dichloroethane
/>-Dichlorobenzene
Dichloromethane
Formaldehyde
8.70
3.92
3.11
2.38
1.68
1.12
1.11
0.84
0.28
0.01
-------
Table 18-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in New Jersey
oo
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Camden, New Jersey (CANJ) - Camden County
Toluene
Methyl tert-butyl ether
Xylenes
Benzene
Methyl isobutyl ketone
Formaldehyde
1,1,1 -Trichloroethane
Hexane
Ethylbenzene
Methanol
655.16
529.03
453.12
202.20
135.59
129.48
120.65
89.32
81.35
59.09
Acrolein
Formaldehyde
1,3 -Butadiene
Bromomethane
Manganese, PM
Benzene
Cyanide Compounds, gas
Naphthalene
Xylenes
Nickel, PM
301,014.59
13,212.64
12,687.52
10,308.00
9,357.78
6,740.12
6,430.71
6,229.86
4,531.17
3,981.65
Acrolein
Formaldehyde
Acetaldehyde
Bromomethane
1,3 -Butadiene
Benzene
Carbon Tetrachloride
Acrylonitrile
Hexachloro- 1 ,3 -butadiene
Tetrachloroethylene
43.25
0.39
0.24
0.10
0.05
0.03
0.01
0.01
0.01
O.01
Chester, New Jersey (CHNJ) - Morris County
Toluene
Methyl fer/-butyl ether
Xylenes
Benzene
Formaldehyde
Ethylbenzene
Hexane
Methyl isobutyl ketone
1,1,1 -Trichloroethane
Methanol
945.16
837.21
690.78
320.42
145.06
136.16
134.66
115.78
109.08
59.57
Acrolein
Nickel, PM
1,3 -Butadiene
Formaldehyde
Benzene
Bromomethane
Xylenes
Naphthalene
Cyanide Compounds, gas
Acetaldehyde
381,629.55
24,324.58
22,551.13
14,801.90
10,680.64
9,638.01
6,907.84
6,499.09
5,943.73
5,094.05
Formaldehyde
Acetaldehyde
0.24
0.14
-------
Table 18-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in New Jersey (Continued)
oo
(!/i
oo
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Elizabeth, New Jersey (ELNJ) - Union County
Toluene
Methyl tert-butyl ether
Xylenes
Hexane
Benzene
Methyl isobutyl ketone
1,1,1 -Trichloroethane
Formaldehyde
Ethylbenzene
Methanol
836.78
626.69
607.19
332.31
255.56
182.87
122.48
120.42
119.06
81.55
Acrolein
Nickel, PM
1,3 -Butadiene
Formaldehyde
Bromomethane
Benzene
Naphthalene
Cyanide Compounds, gas
Xylenes
Chlorine
339,633.20
34,213.95
16,571.17
12,287.61
10,686.00
8,518.80
6,973.06
6,604.11
6,071.91
5,812.50
Acrolein
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Benzene
Carbon Tetrachloride
Acrylonitrile
Tetrachloroethylene
Dichloromethane
Trichloroethylene
37.80
0.65
0.48
0.07
0.04
0.01
0.01
O.01
0.01
O.01
New Brunswick, New Jersey (NBNJ) - Middlesex County
Toluene
Xylenes
Methyl tert-butyl ether
Benzene
Methyl isobutyl ketone
Hexane
Formaldehyde
Ethylbenzene
1,1,1 -Trichloroethane
Glycol ethers, gas
1,326.75
1,092.74
1,041.45
414.77
255.79
228.73
221.09
199.28
177.07
126.68
Acrolein
1,3 -Butadiene
Formaldehyde
Manganese, PM
Bromomethane
Benzene
Xylenes
Naphthalene
Cyanide Compounds, gas
Acetaldehyde
577,997.45
28,277.57
22,560.33
18,349.98
15,616.01
13,825.76
10,927.38
10,741.99
9,482.11
8,333.90
Acrolein
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Benzene
Acrylonitrile
Bromomethane
Carbon Tetrachloride
Tetrachloroethylene
Dichloromethane
26.51
0.22
0.17
0.03
0.02
0.02
0.02
0.01
0.01
O.01
-------
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 18-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ,) as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
risk approximations based on each site's annual averages are limited to those pollutants for
which each respective site sampled. As discussed in Section 18.3, all four New Jersey
monitoring sites sampled for VOC and carbonyl compounds. In addition, the cancer and
noncancer surrogate risk approximations are limited to those sites sampling for a long enough
period for annual averages to be calculated. Although CHNJ sampled for the entire calendar
year, the completeness criteria was not met, so annual averages, and thus, cancer and noncancer
risk approximations, were not calculated for VOC.
Observations from Table 18-9 include the following:
• Benzene was the highest emitted pollutant with cancer UREs in Union, Middlesex,
Morris, and Camden Counties.
• In addition, benzene was the pollutant with the highest toxicity-weighted emissions
(of the pollutants with cancer UREs) for all four counties.
• Seven of the 10 highest emitted pollutants in Camden County also had the highest
toxicity-weighted emissions; six of the highest emitted pollutants in Morris County
also had the highest toxicity-weighted emissions; five of the highest emitted
pollutants in Union County also had the highest toxicity-weighted emissions; and
seven of the highest emitted pollutants in Middlesex County also had the highest
toxicity-weighted emissions.
• As mentioned in the previous section, carbon tetrachloride, benzene, and
acetaldehyde had the highest cancer risk approximations for CANJ, ELNJ, and
NBNJ. Benzene appeared on all three lists for all four New Jersey sites.
Acetaldehyde appeared on the list of 10 highest emitted pollutants for all four sites
(and the list of highest toxicity-weighted emissions for NBNJ). Carbon tetrachloride
did not appear on either emissions-based list for any site.
18-59
-------
Observations from Table 18-10 include the following:
• Toluene was the highest emitted pollutant with cancer UREs in Union, Middlesex,
Morris, and Camden Counties. However, this pollutant did not appear on any list for
highest toxicity-weighted emissions.
• Acrolein was the pollutant with the highest toxicity-weighted emissions (of the
pollutants with cancer RfCs) for all four counties. In addition, this pollutant had the
highest noncancer risk approximation for the three sites where valid annual averages
could be calculated.
• Three of the 10 highest emitted pollutants for all four counties (xylenes, benzene, and
formaldehyde) also had the highest toxicity-weighted emissions.
18.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each New Jersey site were acetaldehyde,
acrolein, benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde, and
tetrachloroethylene.
»«» Formaldehyde had the highest daily average concentration for three of the four sites,
while acetaldehyde had the highest daily average concentration for the fourth
(ELNJ).
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmarks for
all four sites.
18-60
-------
19.0 Sites in New York
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations collected at the NATTS sites in New York, and integrates these concentrations
with emissions, meteorological, and risk information.
19.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the locations of the sites and the surrounding areas. The BXNY monitoring
site is located in the New York-Northern New Jersey-Long Island, NY-NJ-CT-PA CMSA.
ROCH is located in the Rochester, NY MSA. Figures 19-1 and 19-2 are composite satellite
images retrieved from Google™ Maps showing the monitoring sites in their urban locations.
Figures 19-3 and 19-4 identify point source emission locations within 10 miles of each site as
reported in the 2002 NEI for point sources. Table 19-1 describes the area surrounding each
monitoring site and provides supplemental geographical information such as land use, location
setting, and locational coordinates.
BXNY is located on the property of Public School 52 (PS 52) in the Bronx Borough of
New York City, northeast of Manhattan. The site was established in 1999 and is considered one
of the premier parti culate sampling sites in New York City. The surrounding area is urban and
residential, as shown in Figure 19-1. The Bruckner Expressway (1-278) is located a few blocks
east of the monitoring site and other heavily traveled roadways are located within a few miles of
the site. BXNY is less than a half mile from the East River. As Figure 19-3 shows, numerous
point sources are located within 10 miles of the BXNY site. The bulk of the emission sources
are located to the southwest of the site, with another cluster to the west. Many of the emission
sources surrounding BXNY employ fuel combustion processes, use utility boilers, or are
involved in liquids distribution. The point source closest to BXNY uses fuel combustion
processes.
ROCH is located on the east side of Rochester, in western New York, at a power
substation. Rochester is approximately halfway between Syracuse and Buffalo, and Lake
19-1
-------
Figure 19-1. Bronx, New York (BXNY) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 19-2. Rochester, New York (ROCH) Monitoring Site
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 19-3. NEI Point Sources Located Within 10 Miles of BXNY
Not* Dm tafftdlRy dwwij and cofeeatan thtiotil **c*w*«
d may rid rtfir«*nll al Inciinien AIBWI Hi* w*a
Legend
iV BXNYNATTSsile 10 mite radius Q
Source Category Group (No. of Facilities)
* Agricultural Chemicals Production Industrial FaciMy (1)
C Chemicals S Allied Products Facility (3)
E Electric. Gas. & Sanitary Services (1)
Z Electrical S Electronic Equipment Facility (3)
D Fabricated Metal Products Facility (9)
G Food & Kindred Products Facility {1 >
F Furt Combustion Industrial Facility (70)
J Incfustnal Machnwy t Equipment Facility (1)
Instruments 5 Related Products FaciUy (1)
L Liquids Qislnbutton Industrial Facility (11)
a Mineral Produce Processing Industrial Facility \ 1)
County boundary
x Miscellaneous Man ufactyring Industrie* (31
P Miscellaneous Processes Industrial Facility (22)
i l-Jon-ferro-us Metals Processing Industrial Facility (1)
» Pharmaceulical Pfoduclron Proces.sesi Industrial Facility 1.1 j
v Polymws £ Resins Production Industrial Facility (2)
0 Primary Metal Industries Facility lit
* Production of Organic Chemicals I ndustiial Facility (4)
v Rubber S M iscflllsneous Plastic Products FacHrty (3)
U Stone; Clay, Glass, a Contfele Products (1)
3 Surface Coating Processes Industrial Facility (B)
Waste T(eatm>D«! & Disposal indu«Uial FacAty {7}
19-4
-------
Figure 19-4. NEI Point Sources Located Within 10 Miles of ROCH
Legend
fr ROCH NATTS site 10 mite radius
Source Category Group (No. of Facilities)
* Automotive Repair Services, & Parking (1)
C Chemicals & Ailed Products Facility (2)
Z Electrical a Electronic Equipment FaciMy (1)
D Fabricated Metal Products Facility (1)
F Fuel Combustion Industrial Facility (7)
I InciDeration Industrial FaciMy (2)
J Industrial Machinery S Equipment Facility {2)
InstrumentsS Related Products Facility (1)
L Liquids Dtstf i button Industna I Facility (4)
-irw imaavt trtmvi
Hot*. Out t» t*3H j dwM j *nd «•«*«« m» 0 Ifidustrial Facility (1)
> PharmacetJiical Produdion Processes Industrial Facility (2)
Q Primary Metal Industries Facility (1)
4 Production of Organic Cnem Icats Industrial Faaltty (1)
u Stwie Clay Glass. £ Concrete Products (1|
6 Surface Coaling Processes Industrial Facility (9)
a Utility Boilers (1)
• Vtesle Treatment & Disposal Industrial Facility (24>
19-5
-------
Table 19-1. Geographical Information for the New York Monitoring Sites
Site
Code
BXNY
ROCH
AQS Code
36-005-0110
36-055-1007
Location
New York
Rochester
County
Bronx
Monroe
Micro- or
Metropolitan
Statistical Area
New York-
Northern New
Jersey-Long
Island, NY-NJ-
CT-PA CMSA
Rochester, NY
MSA
Latitude
and
Longitude
40.81616,
-73.90207
43.146198,
-77.54813
Land Use
Residential
Residential
Location
Setting
Urban/City
Center
Urban/City
Center
Description of the
Immediate Surroundings
This site was established in 1999 as a replacement
site for Public School 155. Initially the site
contained ozone, oxides of nitrogen, sulfur dioxide,
continuous PM25 and continuous PM10. Following
an upgrade of the electricity, additional monitoring
parameters were added, creating one of the premier
paniculate sampling sites in New York City. The
site contains criteria parameters and methods along
with many experimental methods. This site is
routinely utilized by outside entities for research and
data comparison. Currently the Bureau is assisting
Columbia University with the Multi-Ethnic Study of
Atherosclerosis (MESA). The continuous fine
paniculate (PM2 5) monitoring data from this site are
reported to AirNow.
This site was established in 2004 to consolidate
monitoring operations in the Rochester area. This is
the major site in upstate New York and has been
selected as a PM2 5 Speciation Trends site, a NATTS
site and an NCORE site. The Ozone and continuous
PM2 5 readings from this site are reported to AirNow.
The site is also used by researchers from several
universities for short term monitoring studies.
Current research monitoring includes Mercury
speciation and ultra-fine particle counting. Data
from this site is often integrated in the work from the
PM Health Center which is located at the University
of Rochester Medical Center. The Rochester PM
Center is one of five in the country.
VO
BOLD = EPA-designated NATTS Site
-------
Ontario lies further north. Although the area north and west of the site is primarily residential, as
Figure 19-2 shows, a rail road transverses the area just south of the site, and 1-590 and 1-490
intersect further south. The site is used by researchers from several universities for short-term
monitoring studies. As Figure 19-4 shows, point sources within a 10 mile radius of ROCH are
located primarily to the west and northwest of the site. A number of the emission sources near
the ROCH site are involved in waste treatment and disposal. The emission sources in closest
proximity to ROCH are involved in mineral product processing and utilize electrical equipment.
Table 19-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the New
York monitoring sites. County-level vehicle registration and population data for the Bronx and
Monroe County were obtained from the New York State Department of Motor Vehicles and the
U.S. Census Bureau. Table 19-2 also includes a vehicle registration to county population ratio
(vehicles per person). In addition, the population within 10 miles of each site is presented. An
estimate of 10-mile vehicle registration was calculated by applying the county-level vehicle
registration to population ratio to the 10-mile population surrounding the monitoring site. Table
19-2 also contains annual average daily traffic information, as well as the year of the traffic data
estimate and the source from which it was obtained. Finally, Table 19-2 presents the daily VMT
for each urban area.
Table 19-2. Population, Motor Vehicle, and Traffic Information for the New York
Monitoring Sites
Site
BXNY
ROCH
2007
Estimated
County
Population
1,373,659
729,681
Number
of
Vehicles
Registered
243,523
552,452
Vehicles
per Person
(Registration:
Population)
0.18
0.76
Population
Within
10 Miles
6,437,842
636,955
Estimated
lOmile Vehicle
Ownership
1,141,304
482,248
Annual
Average
Traffic
Data1
101,475
111,600
VMT
(thousands)
299,706
16,038
1 Daily Average Traffic Data reflects 2002 data from the New York State DOT (BXNY) and 2003 data from the New
York State DOT (ROCH)
BOLD = EPA-designated NATTS Site
Observations from Table 19-2 include the following:
• The Bronx had the ninth highest county population but the highest 10-mile radius
population of all NATTS and UATMP sites.
19-7
-------
• The Bronx had the 31st highest county-level vehicle ownership. Although the 10-mile
ownership estimate ranked seventh, given the large population within 10 miles, the
vehicle per person ratio is very low (0.18), which was the lowest vehicle per person
ratio. This might seem surprising given its high population, but may be explained by
the use of mass transportation systems.
• The population surrounding ROCH is significantly lower than BXNY. However, the
county-level vehicle ownership is higher near ROCH. The same is not true of the 10-
mile ownership estimate.
• The population and vehicle ownership data were in the middle of the range of sites
for ROCH.
• The traffic flow near both New York sites is fairly similar and ranked 10th and 11th
among the NATTS and UATMP monitoring sites. The traffic data for BXNY was
obtained from 1-278 between 1-87 & 1-895; the traffic data for ROCH was obtained
from 1-490 between 1-590 & Route 590.
• The New York City area VMT was the highest among urban areas with UATMP or
NATTS sites. By comparison, VMT for the Rochester area ranked 21st.
19.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in New York on sampling days, as well as over the course of the year.
19.2.1 Climate Summary
Weather is somewhat variable in New York City as most frontal systems track across the
area. Precipitation is spread fairly evenly throughout the year, with thunderstorms in the summer
and fall and more significant rain or snow events in the winter and spring. The proximity to the
Atlantic Ocean offers a moderating influence from cold outbreaks; the summer heat and the
urban heat island effect also tend to keep the city warmer than outlying areas. In addition, air
sinking down from the mountains from the west can help drive temperatures higher during warm
spells (Ruffner and Bair, 1987).
Rochester is located in western New York and borders Lake Ontario's south side.
Elevation increases significantly from the shore to the southern most parts of the city, rising over
800 feet. While the lake acts as a moderating influence on the city's temperatures, it also plays a
19-8
-------
major factor in the city's precipitation patterns. Lake effect snow enhances the area's snowfall
totals, although snowfall rates tend to be higher near Lake Ontario than further inland (Ruffner
andBair, 1987).
19.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at La Guardia International Airport (near BXNY) and Greater
Rochester International Airport (near ROCH), WBAN 14732 and 14768, respectively.
Table 19-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 19-3 is the 95 percent
confidence interval for each parameter. As shown in Table 19-3, average meteorological
conditions on sampling days appear cooler than for the entire year. Both New York sites began
sampling October. Therefore, the sample day averages represent only the final three months of
the year, which likely explains the differences seen in Table 19-3.
19.2.3 Composite Back Trajectories for Sampling Days
Figures 19-5 and 19-6 are composite back trajectory maps for the New York monitoring
sites for the days on which samples were collected. Each line represents the 24-hour trajectory
along which a parcel of air traveled toward the monitoring site on a sampling day. Each
concentric circle around the sites in Figures 19-5 and 19-6 represents 100 miles.
Observations from Figures 19-5 and 19-6 include the following:
• The back trajectory maps for BXNY and ROCH include approximately a quarter of
the back trajectories that would be shown for a site sampling for the entire year. As
such, the maps might look much different if an entire year's worth of trajectories
were shown.
19-9
-------
Table 19-3. Average Meteorological Conditions near the New York Monitoring Sites
Site
BXNY
ROCH
Closest NWS
Station and
WBAN
La Guardia
Airport
14732
Greater
Rochester Intl
Airport
14768
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
57.80
±4.86
63.28
±1.95
52.07
±7.58
57.88
±2.22
Average
Temperature
(op)
51.26
±7.12
56.71
± 1.84
44.70
±6.58
49.61
±1.97
Average
Dew Point
Temperature
(°F)
40.06
±7.40
40.26
±1.93
36.27
±6.36
37.92
±1.83
Average
Wet Bulb
Temperature
(»F)
46.10
±6.62
48.91
±1.64
40.93
±6.06
44.02
±1.74
Average
Relative
Humidity
(%)
67.21
±5.19
56.85
± 1.41
73.73
±4.45
67.07
±1.13
Average
Sea Level
Pressure
(mb)
1019.57
±2.57
1016.75
±0.77
1018.11
±2.96
1016.82
±0.73
Average
Scalar Wind
Speed
(kt)
7.85
±1.18
9.27
±0.36
7.60
±1.57
7.99
±0.35
BOLD = EPA-designated NATTS Site
-------
Figure 19-5. Composite Back Trajectory Map for BXNY
-------
Figure 19-6. Composite Back Trajectory Map for ROCH
-------
• Back trajectories originated from a variety of directions at BXNY, although rarely
from the east and southeast. Trajectories primarily originated from the southwest and
west at ROCH.
• The 24-hour air shed domains for BXNY and ROCH were comparable in size to each
other, as well as other NATTS and UATMP sites. The longest trajectory for both
sites was for the same day, December 14, 2007, where the trajectory originated due
west of the sites (near Lake Michigan for BXNY and southeast Minnesota for
ROCH). However, most trajectories originated within 500 miles of the sites.
19.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations near BXNY and ROCH were uploaded into a
wind rose software program, WRPLOT (Lakes, 2006) to produce customized wind roses. A
wind rose shows the frequency of wind directions on a 16-point compass, and uses different
shading to represent wind speeds. Figures 19-7 and 19-8 are the wind roses for the New York
monitoring sites on days that samples were collected. Similar to the back trajectory maps, the
wind roses might look much different if an entire year's worth of observations were shown.
Observations from Figure 19-7 for BXNY include the following:
• Winds from a variety of directions were observed near BXNY, although southerly
and northwesterly winds were observed the most.
• Calm winds were observed for approximately eight percent of the hourly
measurements. Winds exceeding 11 knots made up approximately 18 percent of
observations.
Observations from Figure 19-8 for ROCH include the following:
• The wind rose for ROCH is very different than the wind rose for BXNY.
• Winds from the south, southwest, and west were observed more frequently than
winds from other directions.
• Calm winds were observed for nearly 11 percent of the hourly measurements. Winds
exceeding 11 knots made up approximately 21 percent of observations. These
stronger winds also tended to be from the south, southwest, and west.
19-13
-------
Figure 19-7. Wind Rose for BXNY Sampling Days
WEST;
•SOUTH .--
Figure 19-8. Wind Rose for ROCH Sampling Days
WEST?
19-14
-------
19.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the New York
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
Each pollutant's measured concentration was compared to its associated risk screening value. If
the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 19-4 presents the pollutants that failed at least one screen for each New York monitoring
site and highlights each site's pollutants of interest (shaded). Both New York sites sampled
hexavalent chromium.
Observations from Table 19-4 include the following:
• There were no exceedances of the screening value for hexavalent chromium
concentrations measured at BXNY. This pollutant is considered a pollutant of
interest in order to facilitate analysis for BXNY.
• One measured detection of hexavalent chromium failed a screen for ROCH. This
represents an 11 percent failure rate.
Table 19-4. Comparison of Measured Concentrations and EPA Screening Values for the
New York Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Bronx, New York - BXNY
Hexavalent Chromium
Total
0
0
12
12
0.00
0.00
0.00
0.00
Rochester, New York - ROCH
Hexavalent Chromium
Total
1
1
9
9
11.11
11.11
100.00
100.00
19-15
-------
19.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the New York monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
19.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and whee the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 19-5, where applicable.
Please note that concentration averages have been converted to ng/m3 in Table 19-5 for ease of
viewing.
Table 19-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the New York Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average
(ng/m3)
Bronx, New York - BXNY
Hexavalent Chromium
12
15
0.029
± 0.009
NR
NA
NA
0.028
±0.011
NA
Rochester, New York - ROCH
Hexavalent Chromium
9
13
0.032
±0.015
NR
NA
NA
0.029
±0.016
NA
NR = Not reportable due to the detection criteria for calculating a seasonal average
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
19-16
-------
Observations for BXNY and ROCH from Table 19-5 include the following:
• The daily average concentration of hexavalent chromium was somewhat higher at
ROCH than BXNY. However, the confidence intervals indicate that the difference is
not significant.
• Seasonal averages of hexavalent chromium could only be calculated for autumn, due
to the start date of sampling.
19.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one ore more
the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as described
in Section 3.6.4. The New York sites have not sampled continuously for five years as part of the
National Monitoring Program; therefore, the trends analysis was not conducted.
19.5 Pearson Correlations
Table 19-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations from Table 19-6 include the following:
• All of the correlations for BXNY were weak.
• The correlations between hexavalent chromium concentrations from ROCH and the
temperature and moisture variables were strong and positive. This suggests that as
temperature and moisture content increase, concentration of hexavalent chromium
tend to increase at ROCH. However, the number of measured detections was low (9).
Basing correlations on a low number of samples may skew the correlations.
19.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
19-17
-------
Table 19-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the New York
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Bronx, New York - BXNY
Hexavalent Chromium
12
0.10
0.11
0.03
0.08
-0.21
-0.35
0.23
Rochester, New York - ROCH
Hexavalent Chromium
9
0.51
0.56
0.68
0.62
0.31
-0.27
-0.20
VO
oo
-------
19.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the New York
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. None of the concentrations
of hexavalent chromium measured at the BXNY and ROCH sites exceeded any of the MRL risk
values.
19.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants of interest for the New York monitoring sites and where the annual
average concentrations could be calculated, risk was further examined by reviewing cancer and
noncancer risk estimates from NATA and calculating cancer and noncancer surrogate risk
approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
noncancer surrogate risk approximations are presented in Table 19-7. The data from NATA are
presented for the census tract where the monitoring site is located. The pollutants of interest for
each site are bolded.
The census tract information for the New York sites is as follows:
• The census tract for BXNY is 36005008500, which had a population of 5,428, and
represented less than one percent of the Bronx population in 2000.
• The census tract for ROCH is 36055007700, which had a population of 2,952, and
represented less than one percent of the Monroe County population in 2000.
19-19
-------
Table 19-7. Cancer and Noncancer Risk Summary for the Monitoring Sites in New York
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Hg/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average
(jig/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Bronx, New York (BXNY) - Census Tract ID 36005008500
Hexavalent Chromium
0.012
0.0001
<0.01
0.81
<0.01
NA
NA
NA
Rochester, New York (ROCH) - Census Tract ID 36055007700
Hexavalent Chromium
0.012
0.0001
0.01
0.85
<0.01
NA
NA
NA
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
to
o
-------
Observations for New York sites from Table 19-7 include the following:
• Hexavalent chromium was the only pollutant for which samples were collected at the
New York sites.
• The NATA modeled concentration and risk estimates for hexavalent chromium were
similar for the New York sites. Both estimates were below the level of concern.
• Annual averages (and therefore cancer and noncancer surrogate risk approximations)
could not be calculated for hexavalent chromium due to the sampling duration
criteria.
19.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 19-8 and 19-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 19-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 19-9
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for hexavalent chromium. Therefore, the cancer and noncaner
surrogate risk approximations based on each site's annual averages are limited to that pollutant.
The cancer and noncancer risk approximations are limited to those sites sampling for a long
enough period for annual averages to be calculated. Because sampling did not begin at the New
York sites until October, cancer and noncancer risk approximations were not calculated.
Observations from Table 19-8 include the following:
• Tetrachloroethylene, benzene, and formaldehyde were the highest emitted pollutants
with cancer UREs in the Bronx; benzene, dichloromethane, and formaldehyde were
the highest emitted pollutants with cancer UREs in Monroe County.
19-21
-------
Table 19-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in New York
to
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Bronx, New York (BXNY) - Bronx County
Tetrachloroethylene
Benzene
Formaldehyde
Dichloromethane
1 ,3 -Dichloropropene
Naphthalene
Acetaldehyde
1,3 -Butadiene
£>-Dichlorobenzene
Vinyl chloride
304.00
271.05
139.54
134.42
108.32
66.14
46.15
32.41
23.90
7.72
Naphthalene
Benzene
Tetrachloroethylene
1,3 -Butadiene
Hexavalent Chromium
1 ,3 -Dichloropropene
Arsenic, PM
/>-Dichlorobenzene
Nickel, PM
Acetaldehyde
2.25E-03
2.11E-03
1.79E-03
9.72E-04
8.60E-04
4.33E-04
2.95E-04
2.63E-04
1.80E-04
1.02E-04
Rochester, New York (ROCH) - Monroe County
Benzene
Dichloromethane
Formaldehyde
Tetrachloroethylene
Acetaldehyde
Naphthalene
1,3 -Butadiene
1 ,3 -Dichloropropene
Trichloroethylene
POM, Group 2
683.49
569.66
190.12
149.57
70.79
69.26
61.73
59.07
37.57
14.94
Benzene
Naphthalene
1,3 -Butadiene
Hexavalent Chromium
Tetrachloroethylene
POM, Group 2
Arsenic, PM
POM, Group 5
Dichloromethane
1 ,3 -Dichloropropene
5.33E-03
2.35E-03
1.85E-03
1.14E-03
8.82E-04
8.21E-04
7.15E-04
2.96E-04
2.68E-04
2.36E-04
-------
Table 19-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in New York
to
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Bronx, New York (BXNY) - Bronx County
Methanol
Toluene
Xylenes
Methyl tert-butyl ether
Hexane
1,1,1 -Trichloroethane
Tetrachloroethylene
Benzene
Ethylene glycol
Bromomethane
824.37
820.92
729.47
587.40
478.12
322.20
304.00
271.05
164.83
150.30
Acrolein
Bromomethane
Naphthalene
Nickel, PM
Cyanide Compounds, gas
1,3 -Butadiene
Formaldehyde
Manganese, PM
Benzene
Xylenes
978,214.02
30,060.01
22,046.79
17,335.76
16,843.33
16,204.46
14,238.47
10,131.93
9,034.93
7,294.71
Rochester, New York (ROCH) - Monroe County
Toluene
Xylenes
Methanol
Benzene
Dichloromethane
Hexane
Hydrochloric acid
Methyl isobutyl ketone
Ethylene glycol
1,1,1 -Trichloroethane
1,828.38
1,272.49
877.96
683.49
569.66
553.87
547.42
522.58
418.54
307.27
Acrolein
1,3 -Butadiene
Hydrochloric acid
Naphthalene
Benzene
Formaldehyde
Nickel, PM
Bromomethane
Xylenes
Cyanide Compounds, gas
592,660.55
30,864.96
27,370.91
23,086.30
22,782.84
19,399.94
19,031.82
16,401.62
12,724.95
9,295.79
-------
• The two pollutants with the highest toxi city-weighted emissions (of the pollutants
with cancer UREs) were benzene and naphthalene for both counties, although not
necessarily in that order.
• Six of the highest emitted pollutants also had the highest toxicity-weighted emissions
for the Bronx; seven of the highest emitted pollutants also had the highest toxicity-
weighted emissions for Monroe County.
• Hexavalent chromium, which was the only pollutant sampled at either site, appeared
on the list of highest toxicity-weighted emissions for both counties.
Observations from Table 19-9 include the following:
• Methanol, xylenes, and toluene were the highest emitted pollutants with noncancer
RfCs in both counties, although not necessarily in that order.
• The pollutant with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) was acrolein for both counties.
• Three of the highest emitted pollutants in both counties also had the highest toxicity-
weighted emissions.
• Hexavalent chromium did not appear on either emissions-based noncancer list.
19.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Hexavalent chromium failed one screen for ROCH and did not fail any screens for
BXNY.
»«» Hexavalent chromium did not exceed any of the MRL health benchmarks for either
site.
19-24
-------
20.0 Sites in Oklahoma
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the UATMP sites in Oklahoma, and integrates these concentrations
with emissions, meteorological, and risk information.
20.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. Three Oklahoma sites
(TOOK, TSOK, and TUOK) are located in the Tulsa, OK MSA. The fourth site, CNEP, is
located south of Pry or, Oklahoma. Figures 20-1 through 20-4 are composite satellite images
retrieved from Google™ Maps showing the monitoring sites in their urban and rural locations.
Additionally, Figures 20-5 and 20-6 identify point source emission locations within 10 miles of
each site as reported in the 2002 NEI for point sources. Table 20-1 describes the area
surrounding each monitoring site and provides supplemental geographical information such as
land use, location setting, and locational coordinates.
The CNEP monitoring site was established by the Cherokee Nation Environmental
Program in the tribal community of Cherokee Heights, about halfway between the towns of
Pry or and Locust Grove, in northeastern Oklahoma. Due to the rural nature of the area, a close-
in satellite map is not available. However, Figure 20-1 does show major topographic features of
the area, including a branch of the Grand River from Lake Hudson. The immediate area is rural
and agricultural. An industrial park is located to the west of the community. Figure 20-5 shows
that eleven point sources are located within 10 miles of CNEP. The emission sources are
involved in varying processes, including source categories such as pulp and paper production,
fuel combustion, and chemical product production.
TOOK is located in West Tulsa, on the southwest side of the Arkansas River. The site is
located in the parking lot of the Public Works building. The surrounding area is primarily
industrial. As shown in Figure 20-2, an oil refinery is located just south of the site. Another
refinery is located to the northwest of the site. The monitoring site is positioned between the
20-1
-------
Figure 20-1. Cherokee Heights, Pryor, Oklahoma (CNEP) Monitoring Site
to
o
to
©2008 Google/ONAVTECH
Scale: 3cm = 1 mile
-------
Figure 20-2. Tulsa, Oklahoma (TOOK) Monitoring Site
to
o
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 20-3. Tulsa, Oklahoma (TSOK) Monitoring Site
to
o
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 20-4. Tulsa, Oklahoma (TUOK) Monitoring Site
to
o
mrnm-M ••
"*W. \\
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 20-5. NEI Point Sources Located Within 10 Miles of CNEP
••
"r
twt*. DIM to t*al«j denMj «vd o*o«(too m* Mil lidlmt
«spUy«l may not r«pt««U H tidlilm wtttwi MM in* ol nrt
-------
Figure 20-6. NEI Point Sources Located Within 10 Miles of TOOK, TSOK and TUOK
•
i^**£ni-w
tlow. DIM to t*al«j denMj «vd ol nrt
-------
Table 20-1. Geographical Information for the Oklahoma Monitoring Sites
Site
Code
CNEP
TOOK
AQS Code
40-097-9014
40-143-0235
Location
Pryor
Tulsa
County
Mayes
Tulsa
Micro- or
Metropolitan
Statistical Area
Not in an MSA
Tulsa, OK
Latitude
and
Longitude
36.2284,
-95.25
36.126945,
-95.998941
Land Use
Agricultural
Industrial
Location
Setting
Rural
Urban/City
Center
Description of the
Immediate Surroundings
The CNEP established this ambient air monitoring
site on tribal trust land at the Cherokee Heights
community in 2004. The purpose of this sampling
project is to obtain additional data about the
concentrations of VOCs in ambient air at the Pryor
site and in the adjacent Cherokee Heights tribal
community. This site is approximately 3.8 miles
from the coal -fired power plant, 1.5 miles from the
gas-fired power plant, and 0.75 mile from the sewage
lagoon of the industrial park. Current
instrumentation at the site includes the following: R
& P TEOM for continuous PM10 measurement
(Federal Equivalent Method), R & P TEOM with
FDMS for continuous PM2 5 measurement (the
FDMS includes reference flow to account for volatile
loss), R & P 2025 sequential sampler for PM2 5
(Federal Reference Method), API gaseous monitors
for NOX, NOy, ozone, and SO2, and MetOne
meteorological instruments for wind speed, wind
direction, ambient temperature, and relative humidity.
This site is located approximately 3A mile east of I-
244. It is primarily located in an industrial area with
Sun Refinery approximately 2 miles NW and Sinclair
Refinery approximately YA mile South of site. It
contains SO2, H2S, TSP Metals, and Toxics (VOC
and Carbonyl).
to
o
oo
-------
Table 20-1. Geographical Information for the Oklahoma Monitoring Sites (Continued)
Site
Code
TSOK
TUOK
AQS Code
40-143-0172
40-143-0191
Location
Tulsa
Tulsa
County
Tulsa
Tulsa
]Micro- or
Metropolitan
Statistical Area
Tulsa, OK
Tulsa, OK
Latitude
and
Longitude
36.164435,
-95.985204
36.141697,
-95.983793
Land Use
Residential
Residential
Location
Setting
Suburban
Urban/City
Center
Description of the
Immediate Surroundings
The Greenwood site is located approximately 200
yards N-NE of 1-244 on the Oklahoma State
University at Tulsa Campus. It is primarily
neighborhood scale with no major industry nearby. A
railroad track switching site is located approximately
50 ft. SE of the site. It contains TSP Metals and
Toxics (VOC and Carbonyl).
This site is located approximately 50 ft. south of
Highway 5 1, a major crosstown expressway. It is
primarily neighborhood scale with no major industry
nearby and influenced primarily by downtown traffic.
It contains CO, PM10, TSP Metals, and Toxics (VOC
and Carbonyl).
to
o
-------
Arkansas River and 1-244, which runs parallel to Southwest Boulevard (which is pictured in
Figure 20-2). A rail yard is located on the opposite side of 1-244.
TSOK is located in central Tulsa, north of Exit 6 on 1-244 and west of US-75. The site is
located on the property of Oklahoma State University's Tulsa campus, as shown in Figure 20-3.
Roberts Park is located to the north of the site and a railroad switching station is located very
close the monitoring site. Much of the surrounding area is residential.
TUOK is located just on the other side of the Arkansas River from TOOK, in downtown
Tulsa. The site is located just south of the US-64/US-75/Highway 51 interchange, as shown in
Figure 20-4. Although commercial areas are located immediately to the west, the surrounding
areas are primarily residential.
Figure 20-6 shows that the three Tulsa sites are within 5 miles of each other, and are
surrounded by more point sources than CNEP. Most of the emission sources are located along a
line running northeast-southwest across Tulsa County. Fabricated metal production and surface
coating processes are the most numerous emission sources surrounding the Tulsa sites.
Table 20-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Oklahoma monitoring sites. County-level vehicle registration and population data for Tulsa and
Mayes County were obtained from the Oklahoma Tax Commission and the U.S. Census Bureau.
Table 20-2 also includes a vehicle registration to county population ratio (vehicles per person).
In addition, the population within 10 miles of each site is presented. An estimate of 10-mile
vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 20-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 20-2 presents the daily VMT for each
urban area (where applicable).
20-10
-------
Table 20-2. Population, Motor Vehicle, and Traffic Information for the Oklahoma
Monitoring Sites
Site
CNEP
TOOK
TSOK
TUOK
2007
Estimated
County
Population
39,627
585,068
585,068
585,068
Number
of
Vehicles
Registered
29,398
506,011
506,011
506,011
Vehicles
per Person
(Registration:
Population)
0.74
0.86
0.86
0.86
Population
Within
10 Miles
29,152
461,773
337,331
463,689
Estimated
10-mile
Vehicle
Ownership
21,627
399,376
291,749
401,033
Annual
Average
Traffic
Data1
5
67,092
33,800
45,300
VMT
(thousands)
NA
20,904
20,904
20,904
1 Daily Average Traffic Data reflects data from the AIRS/AQS (CNEP) and 2006 data from the Oklahoma DOT
(TOOK, TSOK, TUOK)
Observations from Table 20-2 include the following:
• The Mayes County (CNEP) population is significantly lower than the Tulsa County
population. This is also true of the 10-mile population. Compared to other
monitoring sites, the Tulsa populations were in the middle of the range, while
CNEP's populations were on the low end.
• The Mayes County vehicle registration and 10-mile estimated vehicle registration
data are also significantly lower than similar information in Tulsa County. These
observations are expected given the rural nature of the area surrounding CNEP
compared to the urban location of the Tulsa sites. Compared to other monitoring
sites, the ownership estimates followed a similar pattern as the populations.
• The average daily traffic volume passing the CNEP site is considerably lower than
each of the Tulsa sites, and is the lowest compared to all other monitoring sites. Of
the three Tulsa sites, TOOK experiences the highest daily traffic, while TSOK
experiences the least.
• VMT for the Tulsa MSA is approximately 21 million miles, which is relatively low
compared to other urban areas. For comparison purposes, VMT for the New York
City area is 300 million miles. VMT was not available for CNEP.
20.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Oklahoma on sampling days, as well as over the course of the year.
20.2.1 Climate Summary
Tulsa is located in northeast Oklahoma, just southeast of the Osage Indian Reservation,
and along the Arkansas River. The area is characterized by a continental climate, with warm and
20-11
-------
humid summers and cool winters. The region experiences ample rainfall, with spring as the
wettest season. A southerly wind prevails, bringing warm, moist air northward from the Gulf of
Mexico. Pryor is also in northeast Oklahoma, approximately 30 miles east of Tulsa, so the
climate is much like that of Tulsa. Oklahoma is part of "Tornado Alley", where severe
thunderstorms are capable of producing strong winds, hail, and tornadoes. Tornadoes are more
prevalent here than any other region in the U.S. (Ruffner and Bair, 1987).
20.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The three
closest NWS weather stations are located at Claremore Regional Airport (near CNEP), Richard
Lloyd Jones Jr. Airport (near TOOK and TUOK), and Tulsa International Airport (near TSOK),
WBAN 53940, 53908, and 13968, respectively.
Table 20-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 20-3 is the 95 percent
confidence interval for each parameter. As shown in Table 20-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
20.2.3 Composite Back Trajectories for Sampling Days
Figures 20-7 through 20-10 are composite back trajectory maps for the Oklahoma
monitoring sites for the days on which samples were collected. Each line represents the 24-hour
trajectory along which a parcel of air traveled toward the monitoring site on a sampling day.
Each concentric circle around the sites in Figures 20-7 through 20-10 represents 100 miles.
20-12
-------
Table 20-3. Average Meteorological Conditions near the Oklahoma Monitoring Sites
Site
CNEP
TOOK
TSOK
TUOK
Closest NWS
Station and
WBAN
Claremore
Regional
Airport
53940
Richard Lloyd
Jones Jr.
Airport
53908
Tulsa
International
Airport
13968
Richard Lloyd
Jones Jr.
Airport
53908
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
70.68
±4.40
70.03
±1.85
73.52
±4.11
71.45
±1.88
73.08
±4.30
71.23
±1.88
73.43
±4.17
71.45
±1.88
Average
Temperature
(op)
60.81
±4.17
59.79
± 1.78
63.12
±3.99
60.91
±1.82
63.32
±4.23
61.65
± 1.84
62.94
±4.04
60.91
±1.82
Average
Dew Point
Temperature
(°F)
48.93
±4.26
47.74
±1.88
51.93
±4.08
49.23
±1.91
50.66
±4.17
48.86
±1.90
51.64
±4.11
49.23
±1.91
Average
Wet Bulb
Temperature
(°F)
54.73
±4.17
53.73
±1.78
56.92
±3.70
54.68
±1.71
56.32
±3.79
54.80
± 1.69
56.69
±3.73
54.68
±1.71
Average
Relative
Humidity
(%)
68.71
±2.96
68.20
± 1.17
69.84
±2.52
68.61
±1.15
66.39
±2.89
65.96
± 1.29
69.61
±2.52
68.61
± 1.15
Average
Sea Level
Pressure
(mb)
NA
NA
1017.64
± 1.38
1017.81
±0.64
1016.35
± 1.49
1016.59
±0.66
1017.62
±1.40
1017.81
±0.64
Average
Scalar Wind
Speed
(kt)
6.22
±0.85
6.29
±0.33
5.37
±0.68
5.41
±0.28
7.57
±0.82
7.71
±0.34
5.34
±0.68
5.41
±0.28
to
o
NA = Sea level pressure was not recorded at the Claremore Regional Airport
-------
Figure 20-7. Composite Back Trajectory Map for CNEP
to
o
>
5 SO 100 330 3DQ «M
-------
Figure 20-8. Composite Back Trajectory Map for TOOK
to
o
-------
Figure 20-9. Composite Back Trajectory Map for TSOK
to
o
£T^~ /V
-------
Figure 20-10. Composite Back Trajectory Map for TUOK
to
o
\N
/-»•——•—>, V
v
\
\ "\ \
\ v V 1 >
I / V V *
\ \
-------
Observations from Figures 20-7 through 20-10 include the following:
• The back trajectory maps are very similar to each other. This is expected, given their
close proximity to each other and the similarity in sampling days.
• Back trajectories originated from a variety of directions at the Oklahoma sites. The
bulk of the trajectories originated from the south. There is a second cluster of
trajectories originating from the northwest.
• The 24-hour air shed domains for these four sites were somewhat larger in size than
other monitoring sites. The furthest away a trajectory originated was southern
Manitoba, Canada, or greater than 900 miles away. However, most trajectories
originated within 500 miles of the sites.
20.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations near the Oklahoma sites, as presented in
Section 20.2.2, were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to
produce customized wind roses. A wind rose shows the frequency of wind directions on a 16-
point compass, and uses different shading to represent wind speeds. Figures 20-11 through 20-
14 are the wind roses for the Oklahoma monitoring sites on days that samples were collected.
Observations from Figures 20-11 through 20-14 include the following:
• The wind roses for the Oklahoma sites are fairly similar to each other.
• Southerly winds prevailed near each monitoring site.
• The percentage of calm winds varied among the sites, ranging from nine percent near
TSOK to 28 percent near TUOK.
• The percentage of winds exceeding 11 knots also varied among the sites, ranging
from eight percent near TOOK and TUOK to 19 percent near TSOK. The strongest
winds were most frequently from the south and south-southwest.
20.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Oklahoma
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
20-18
-------
Figure 20-11. Wind Rose for CNEP Sampling Days
NORTH"--
/'•J'LS I
25%
" X 20%
~ - N 15%
10%
% ': ': I
•SOUTH ,--
\ EAST
WIND SPEED
(Knots)
CH = 22
• 17 - 21
• 11 - 17
• 7- 11
CH 4-7
• 2- 4
Cdlms: 18.75%
Figure 20-12. Wind Rose for TOOK Sampling Days
20%
UTH .--
WIND SPEED
(Knots)
n *a
• 17 - 21
• 11 - 17
• 7- 11
CH 1-7
H 2- 4
Calms: 27.40%
20-19
-------
Figure 20-13. Wind Rose for TSOK Sampling Days
NORTH"---.
WEST I
30%
24%
18%
1 2%
: EAST
WIND SPEED
(Knots)
n -22
• 17 - 21
^| 11 • 17
^| 7- 11
2- 4
Calms: 8.85H
Figure 20-14. Wind Rose for TUOK Sampling Days
•SOUTH .--
WND SPEED
(Knots)
n -=2
H 17 - 21
• 11 - 17
• 7- 11
EH
2- 4
Calms: 27.35%
20-20
-------
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of each site's total failed screens.
Table 20-4 presents the pollutants that failed at least one screen for each Oklahoma monitoring
site and highlights each site's pollutants of interest (shaded). The three Tulsa sites sampled for
VOC, carbonyls, and metals (TSP); CNEP sampled for VOC only.
Table 20-4. Comparison of Measured Concentrations and EPA Screening Values for the
Oklahoma Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Pryor, Oklahoma - CNEP
Benzene
Acrolein
Carbon Tetrachloride
1,3 -Butadiene
Acrylonitrile
1 ,2-Dichloroethane
Total
55
55
55
16
2
1
184
55
55
55
41
2
1
209
100.00
100.00
100.00
39.02
100.00
100.00
88.04
29.89
29.89
29.89
8.70
1.09
0.54
29.89
59.78
89.67
98.37
99.46
100.00
Tulsa, Oklahoma, Site #1 - TOOK
Acetaldehyde
Acrolein
Benzene
Carbon Tetrachloride
Arsenic (TSP)
1,3 -Butadiene
Manganese (TSP)
Formaldehyde
£>-Dichlorobenzene
Tetrachloroethylene
Nickel (TSP)
Cadmium (TSP)
Acrylonitrile
Total
61
60
60
60
59
59
58
58
30
25
16
7
2
555
61
60
60
60
59
60
59
61
60
58
59
59
2
718
100.00
100.00
100.00
100.00
100.00
98.33
98.31
95.08
50.00
43.10
27.12
11.86
100.00
77.30
10.99
10.81
10.81
10.81
10.63
10.63
10.45
10.45
5.41
4.50
2.88
1.26
0.36
10.99
21.80
32.61
43.42
54.05
64.68
75.14
85.59
90.99
95.50
98.38
99.64
100.00
20-21
-------
Table 20-4. Comparison of Measured Concentrations and EPA Screening Values for the
Oklahoma Monitoring Sites (Continued)
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Tulsa, Oklahoma, Site #2 - TSOK
Benzene
Carbon Tetrachloride
Acrolein
Acetaldehyde
1,3 -Butadiene
Formaldehyde
Arsenic (TSP)
Manganese (TSP)
£>-Dichlorobenzene
Tetrachloroethylene
Nickel (TSP)
Acrylonitrile
1 ,2-Dichloroethane
Cadmium (TSP)
1,1,2-Trichloroethane
Trichloroethylene
Total
59
59
59
58
56
55
54
52
34
23
12
8
2
2
1
1
535
59
59
59
58
58
58
56
56
58
53
56
8
2
56
2
41
739
100.00
100.00
100.00
100.00
96.55
94.83
96.43
92.86
58.62
43.40
21.43
100.00
100.00
3.57
50.00
2.44
72.40
11.03
11.03
11.03
10.84
10.47
10.28
10.09
9.72
6.36
4.30
2.24
1.50
0.37
0.37
0.19
0.19
11.03
22.06
33.08
43.93
54.39
64.67
74.77
84.49
90.84
95.14
97.38
98.88
99.25
99.63
99.81
100.00
Tulsa, Oklahoma, Site #3 - TUOK
Acetaldehyde
Formaldehyde
Acrolein
Benzene
Carbon Tetrachloride
Arsenic (TSP)
1,3 -Butadiene
Manganese (TSP)
Tetrachloroethylene
£>-Dichlorobenzene
Nickel (TSP)
Acrylonitrile
Trichloroethylene
Total
61
60
59
59
59
58
56
56
42
29
11
7
1
558
61
61
59
59
59
58
58
58
59
58
58
7
35
690
100.00
98.36
100.00
100.00
100.00
100.00
96.55
96.55
71.19
50.00
18.97
100.00
2.86
80.87
10.93
10.75
10.57
10.57
10.57
10.39
10.04
10.04
7.53
5.20
1.97
1.25
0.18
10.93
21.68
32.26
42.83
53.41
63.80
73.84
83.87
91.40
96.59
98.57
99.82
100.00
20-22
-------
Observations from Table 20-4 include the following:
• Six pollutants with a total of 184 measured concentrations failed at least one screen
for CNEP; 13 pollutants with a total of 555 measured concentrations failed screens
for TOOK; 16 pollutants with a total of 535 measured concentrations failed screens
for TSOK; and 13 pollutants with a total of 558 measured concentrations failed
screens for TUOK.
• The following four pollutants were identified as pollutants of interest for all four
sites: acrolein, benzene, 1,3-butadiene, and carbon tetrachloride. If only the Tulsa
sites are considered, the list of common pollutants also includes acetaldehyde,
formaldehyde, />-dichlorobenzene, tetrachloroethylene, arsenic, and manganese.
• All of the four common pollutants of interest failed 100 percent of screens for each
site.
• The percentage of measured detections failing screens (of the pollutants that failed at
least one screen) ranged from 72 percent (TSOK) to 88 percent (CNEP).
20.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Oklahoma monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific summaries are provided in Appendices J through O.
In addition, concentration averages for select pollutants are presented from previous sampling
years in order to characterize concentration trends at each site, where applicable.
20.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 20-5, where applicable.
20-23
-------
Table 20-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Oklahoma Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(Hg/m3)
Annual
Average1
(jig/m3)
Pryor, Oklahoma - CNEP
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
55
55
41
55
55
55
55
55
1.52
±0.17
0.47
±0.05
0.03
±0.01
0.65
±0.03
1.24
±0.14
0.59
±0.13
0.04
±0.01
0.59
±0.06
1.85
±0.35
0.42
±0.07
0.03
±0.01
0.64
±0.04
1.52
±0.35
0.42
±0.05
0.02
±0.01
0.67
±0.09
1.40
±0.32
0.48
±0.06
NR
0.69
±0.07
1.52
±0.17
0.47
±0.05
0.03
±0.01
0.65
±0.03
Tulsa, Oklahoma, Site #1 - TOOK
Acetaldehyde
Acrolein
Arsenic (TSP)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Tetrachloroethylene
61
60
59
60
60
60
60
61
59
58
61
60
59
60
60
60
60
61
59
60
1.91
±0.23
0.89
±0.14
0.01
±0.01
2.05
±0.31
0.09
±0.01
0.57
±0.03
0.12
±0.02
3.00
±0.42
0.03
±0.01
0.22
±0.05
1.26
±0.30
0.57
±0.15
0.01
±0.01
1.68
±0.50
0.11
±0.04
0.47
±0.07
0.07
±0.01
1.62
±0.33
0.03
±0.01
0.17
±0.07
1.72
±0.43
1.08
±0.41
0.01
±0.01
1.73
±0.41
0.07
±0.02
0.59
±0.06
0.17
±0.05
2.41
±0.42
0.03
±0.01
0.22
±0.06
2.61
±0.39
1.11
±0.24
0.01
±0.01
2.07
±0.33
0.07
±0.01
0.61
±0.04
0.12
±0.02
4.90
±0.76
0.03
±0.01
0.15
±0.03
1.90
±0.37
0.72
±0.15
0.01
±0.01
2.65
±0.92
0.10
±0.03
0.59
±0.05
0.09
±0.03
2.75
±0.55
0.04
±0.01
0.31
±0.15
1.91
±0.23
0.89
±0.14
0.01
±0.01
2.05
±0.31
0.09
±0.01
0.57
±0.03
0.12
±0.02
3.00
±0.42
0.03
±0.01
0.21
±0.05
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
20-24
-------
Table 20-5. Daily, Seasonal, and Annual Average Concentrations for the Pollutants of
Interest for the Oklahoma Monitoring Sites (Continued)
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(Hg/m3)
Annual
Average1
(jig/m3)
Tulsa, Oklahoma, Site #2 - TSOK
Acetaldehyde
Acrolein
Arsenic (TSP)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Tetrachloroethylene
58
59
56
59
58
59
58
58
56
53
58
59
56
59
59
59
59
58
56
59
1.57
±0.18
0.88
±0.16
0.01
±0.01
0.99
±0.11
0.07
±0.01
0.60
±0.03
0.11
±0.02
3.03
±0.46
0.02
±0.01
0.19
±0.04
1.11
±0.23
0.63
±0.15
0.01
±0.01
0.83
±0.25
0.07
±0.03
0.54
±0.07
0.06
±0.01
1.62
±0.33
0.01
±0.01
0.11
±0.05
1.45
±0.28
1.20
±0.42
0.01
±0.01
0.97
±0.19
0.06
±0.01
0.62
±0.06
0.16
±0.05
2.50
±0.39
0.01
±0.01
0.19
±0.10
2.13
±0.34
0.82
±0.13
0.01
±0.01
1.03
±0.16
0.07
±0.01
0.63
±0.05
0.12
±0.01
5.10
±0.92
0.02
±0.01
0.21
±0.09
1.56
±0.33
0.82
±0.41
0.01
±0.01
1.15
±0.29
0.08
±0.03
0.61
±0.06
0.10
±0.03
2.83
±0.68
0.02
±0.01
0.18
±0.05
1.57
±0.18
0.88
±0.16
0.01
±0.01
0.99
±0.11
0.07
±0.01
0.60
±0.03
0.11
±0.02
3.03
±0.46
0.02
±0.01
0.17
±0.04
Tulsa, Oklahoma, Site #3 - TUOK
Acetaldehyde
Acrolein
Arsenic (TSP)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Tetrachloroethylene
61
59
58
59
58
59
58
61
58
59
61
59
58
59
59
59
59
61
58
59
2.15
±0.24
1.05
±0.19
0.01
±O.01
1.29
±0.14
0.10
±0.02
0.57
±0.03
0.13
±0.02
3.27
±0.40
0.02
±O.01
0.37
±0.10
1.33
±0.29
0.68
±0.14
0.01
±O.01
1.11
±0.24
0.11
±0.03
0.44
±0.09
0.13
±0.07
1.88
±0.35
0.02
±0.01
0.18
±0.10
2.03
±0.44
0.95
±0.20
0.01
±O.01
1.24
±0.30
0.09
±0.03
0.62
±0.05
0.16
±0.05
2.93
±0.45
0.02
±0.01
0.36
±0.12
2.93
±0.37
1.41
±0.49
0.01
±O.01
1.30
±0.18
0.08
±0.02
0.61
±0.05
0.13
±0.02
4.88
±0.70
0.02
±0.01
0.61
±0.28
2.05
±0.39
1.09
±0.43
0.01
±0.01
1.47
±0.32
0.13
±0.04
0.59
±0.03
0.09
±0.02
2.87
±0.63
0.02
±O.01
0.28
±0.07
2.15
±0.24
1.05
±0.19
0.01
±O.01
1.29
±0.14
0.10
±0.02
0.57
±0.03
0.13
±0.02
3.27
±0.40
0.02
±O.01
0.37
±0.10
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
20-25
-------
Observations for CNEP from Table 20-5 include the following:
• Acrolein exhibited the highest daily average concentration by mass. This
concentration (1.52 ± 0.17 |ig/m3) was more than twice the next highest daily average
concentration (carbon tetrachloride, 0.65 ± 0.03 |ig/m3).
• As shown in Table 4-11, CNEP had the second highest daily average concentration of
acrolein among all NATTS and UATMP sites.
• The seasonal concentrations of the pollutants of interest for CNEP did not vary much
across the seasons. Although benzene appears to be higher during the winter, the
confidence interval shows that the difference is not significant. A seasonal average
could not be calculated for 1,3-butadiene for autumn due to the low number of
measured detections.
Observations for the Tulsa sites from Table 20-5 include the following:
• Formaldehyde, benzene, and acetaldehyde exhibited the highest daily average
concentrations by mass for each site (although not necessarily in that order).
• As shown in Table 4-11, the Tulsa sites had the fourth, sixth, and seventh highest
daily average concentrations of acrolein among all NATTS and UATMP sites.
TOOK and TUOK also had the second and eighth highest daily average of
concentrations of benzene.
• The Tulsa sites were the only sites to monitor for TSP metals, so they are the only
sites that appear in Table 4-10.
• The average summer concentrations of acetaldehyde and formaldehyde were higher
than other seasons for the Tulsa sites.
20.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one ore more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. None of the Oklahoma site have sampled continuously for five years
as part of the National Monitoring Program; therefore, the trends analysis was not conducted.
20.5 Pearson Correlations
Table 20-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
20-26
-------
Table 20-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
Oklahoma Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Pryor, Oklahoma - CNEP
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
55
55
41
55
0.03
-0.32
-0.55
0.15
0.07
-0.39
-0.54
0.19
0.02
-0.31
-0.50
0.20
-0.10
-0.10
-0.27
0.22
-0.23
0.25
0.12
0.14
NA
NA
NA
NA
0.27
-0.20
-0.16
0.07
Tulsa, Oklahoma, Site #1 - TOOK
Acetaldehyde
Acrolein
Arsenic (TSP)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Tetrachloroethylene
61
60
59
60
60
60
60
61
59
58
0.59
0.28
0.28
0.22
-0.25
0.42
0.16
0.77
-0.01
-0.11
0.50
0.31
0.24
0.11
-0.35
0.46
0.15
0.73
-0.07
-0.18
0.47
0.30
0.22
0.09
-0.31
0.48
0.13
0.67
-0.22
-0.16
0.48
0.30
0.23
0.10
-0.34
0.47
0.14
0.70
-0.15
-0.17
0.00
0.02
-0.01
0.00
0.08
0.18
-0.05
-0.06
-0.55
0.06
-0.17
-0.05
0.10
0.06
0.25
-0.30
0.07
-0.28
0.18
0.15
-0.58
-0.09
-0.36
-0.58
-0.56
0.13
-0.14
-0.37
-0.06
-0.32
Tulsa, Oklahoma, Site #2 - TSOK
Acetaldehyde
Acrolein
Arsenic (TSP)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Tetrachloroethylene
58
59
56
59
58
59
58
58
56
53
0.57
0.21
0.21
0.21
-0.03
0.27
0.25
0.74
0.22
0.11
0.54
0.23
0.15
0.18
-0.06
0.32
0.24
0.75
0.18
0.10
0.45
0.21
0.13
0.15
-0.08
0.35
0.24
0.63
-0.01
0.13
0.49
0.22
0.14
0.15
-0.08
0.33
0.24
0.68
0.08
0.12
-0.27
-0.08
-0.01
-0.07
-0.06
0.12
0.00
-0.30
-0.53
0.13
-0.16
-0.07
0.10
0.07
0.19
-0.24
-0.04
-0.30
0.03
-0.11
-0.40
-0.01
-0.41
-0.54
-0.60
0.03
-0.12
-0.20
-0.31
-0.39
to
o
to
NA = Sea level pressure was not recorded at the Claremore Regional Airport
-------
Table 20-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
Oklahoma Monitoring Sites (Continued)
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Tulsa, Oklahoma, Site #3 - TUOK
Acetaldehyde
Acrolein
Arsenic (TSP)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Tetrachloroethylene
61
59
58
59
58
59
58
61
58
59
0.68
0.35
0.10
0.07
-0.24
0.42
-0.09
0.74
-0.12
0.39
0.61
0.37
0.05
0.01
-0.30
0.44
-0.03
0.70
-0.20
0.34
0.59
0.35
0.06
0.05
-0.26
0.48
0.03
0.64
-0.33
0.32
0.60
0.36
0.05
0.02
-0.29
0.46
-0.01
0.67
-0.26
0.33
0.12
0.01
0.06
0.19
0.11
0.30
0.21
-0.02
-0.48
0.04
-0.18
-0.10
0.11
0.13
0.38
-0.23
-0.08
-0.24
0.25
-0.03
-0.59
-0.13
-0.24
-0.68
-0.57
-0.06
-0.08
-0.42
-0.21
-0.33
NA = Sea level pressure was not recorded at the Claremore Regional Airport
to
o
to
oo
-------
Observations for CNEP from Table 20-6 include the following:
• 1,3-Butadiene exhibited strong negative correlations with the maximum, average, and
dew point temperatures. This indicates than an increase in these parameters
correlates with a decrease in concentration.
• The remaining correlations were weak.
Observations for the Tulsa sites from Table 20-6 include the following:
• Formaldehyde and acetaldehyde exhibited strong positive correlations with the
maximum, average, dew point, and wet bulb temperatures. This indicates than an
increase in these parameters correlates with an increase in the concentrations of these
pollutants. These correlations support the observations in seasonal averages
discussed in Section 20.4.1.
• Manganese exhibited strong negative correlations with the relative humidity for all
three sites. This indicates that decreases in relative humidity lead to increases in
manganese concentrations.
• All but two (carbon tetrachloride for TOOK and TSOK) of the correlations with wind
speed were negative, although of varying magnitude. This indicates that decreasing
wind speed correlates with increasing concentrations of the pollutants of interest.
20.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
20.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Oklahoma
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 20-7. Where a seasonal or annual average exceeds the
20-29
-------
Table 20-7. MRL Risk Screening Assessment Summary for the Oklahoma Monitoring Sites
Site
CNEP
TOOK
TSOK
TUOK
Method
TO-15
TO-15
TO-15
TO-15
Pollutant
Acrolein
Acrolein
Acrolein
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
7.00
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/55
0/60
0/59
0/59
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
0.09
0.09
0.09
Winter
Average
(Ug/m3)
1.24
±0.14
0.57
±0.15
0.63
±0.15
0.68
±0.14
Spring
Average
(Ug/m3)
1.85
±0.35
1.08
±0.41
1.20
±0.42
0.95
±0.20
Summer
Average
(Ug/m3)
1.52
±0.35
1.11
±0.24
0.82
±0.13
1.41
±0.49
Autumn
Average
(Ug/m3)
1.40
±0.32
0.72
±0.15
0.82
±0.41
1.09
±0.43
ATSDR
Chronic
MRL
(Ug/m3)
—
~
~
~
Annual
Average1
(Ug/m3)
1.52
±0.17
0.89
±0.14
0.88
±0.16
1.05
±0.19
to
o
BOLD = exceedance of the intermediate or chronic MRL
~ = an MRL risk factor is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 20-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• All four seasonal averages of acrolein exceeded the intermediate MRL for all four
sites.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
20.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Oklahoma monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 20-8. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the Oklahoma monitoring sites is as follows:
• The census tract for CNEP is 40097040400, which had a population of 5,307 and
represented approximately 14 percent of the Mayes County population in 2000.
• The census tract for TOOK is 40143004600, which had a population of 3,147 and
represented approximately 0.6 percent of the Tulsa County population in 2000.
• The census tract for TSOK is 40143001000, which had a population of 1,494 and
represented less than 0.3 percent of the Tulsa County population in 2000.
• The census tract for TUOK is 40143003200, which had a population of 1,677, and
represented approximately 0.3 percent of the Tulsa County population in 2000.
20-31
-------
Table 20-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Oklahoma
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Pryor, Oklahoma (CNEP) - Census Tract ID 40097040400
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
1 ,2-Dichloroethane
—
0.000068
0.000007
0.00003
0.000015
0.000026
0.00002
0.002
0.03
0.002
0.04
2.4
0.02
0.01
0.43
0.01
0.21
0.01
—
0.01
3.36
0.30
3.19
0.32
0.94
0.01
0.01
0.01
0.01
O.01
1.52 ±0.17
0.03 ±0.01
0.47 ±0.05
0.03 ±0.01
0.65 ±0.03
0.04 ±O.01
—
1.79
3.32
0.83
9.69
1.11
75.85
0.01
0.02
0.01
0.02
O.01
Tulsa, Oklahoma (TOOK) Site #1 - Census Tract ID 40143004600
Acetaldehyde
Acrolein
Acrylonitrile
Arsenic (TSP)
Benzene
1,3-Butadiene
Cadmium (TSP)
Carbon Tetrachloride
p-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Nickel (TSP)
Tetrachloroethylene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.0018
0.000015
0.000011
5.5E-09
—
0.00016
0.000005
0.009
0.00002
0.002
0.00003
0.03
0.002
0.00002
0.04
0.8
0.0098
0.00005
0.000065
0.27
1.90
0.13
0.01
0.01
3.89
0.24
O.01
0.21
0.03
1.74
0.01
0.01
0.17
4.20
—
0.01
0.12
30.34
7.34
0.14
3.20
0.35
0.01
—
0.44
0.99
0.21
6.59
0.01
0.01
0.12
0.12
O.01
0.01
O.01
0.17
0.03
0.04
0.01
1.91 ±0.23
0.89 ±0.14
0.04 ±0.01
0.01 ±0.01
2.05 ±0.31
0.09 ±0.01
O.01±O.01
0.57 ±0.03
0.12 ±0.02
3.00 ±0.42
0.03 ±0.01
0.01 ±0.01
0.21 ±0.05
3.81
—
2.51
4.40
14.33
2.61
0.53
8.54
1.29
0.02
—
0.30
1.06
0.21
44.30
0.02
0.03
0.07
0.04
0.01
0.01
O.01
0.31
0.60
0.03
0.01
to
o
to
Bold = pollutant of interest
- = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 20-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Oklahoma (Continued)
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Hg/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Hg/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Tulsa, Oklahoma (TSOK) Site #2 - Census Tract ID 40143001000
Acetaldehyde
Acrolein
Acrylonitrile
Arsenic (TSP)
Benzene
1,3-Butadiene
Cadmium (TSP)
Carbon Tetrachloride
p-Dichlorobenzene
1 ,2-Dichloroethane
Formaldehyde
Manganese (TSP)
Nickel (TSP)
Tetrachloroethylene
1 , 1 ,2-Trichloroethane
Trichloroethylene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.0018
0.000015
0.000011
0.000026
5.5E-09
—
0.00016
0.000005
0.000016
0.000002
0.009
0.00002
0.002
0.00003
0.03
0.002
0.00002
0.04
0.8
2.4
0.0098
0.00005
0.000065
0.27
0.4
0.6
1.69
0.11
0.01
0.01
1.66
0.15
O.01
0.21
0.03
0.03
1.44
0.01
O.01
0.18
O.01
0.08
3.74
—
0.01
0.07
12.94
4.48
0.08
3.16
0.30
0.85
0.01
—
0.17
1.05
O.01
0.17
0.18
5.51
0.01
0.01
0.05
0.07
O.01
0.01
0.01
0.01
0.14
0.02
0.01
O.01
O.01
O.01
1.57 ±0.18
0.88 ±0.16
0.05 ±0.02
0.01 ±0.01
0.99±0.11
0.07 ±0.01
O.01±O.01
0.60 ±0.03
0.11 ±0.02
0.04 ±0.01
3.03 ±0.46
0.02 ±0.01
O.01±O.01
0.17 ±0.04
0.05 ±O.01
0.16 ±0.03
3.14
—
3.37
3.92
6.95
2.10
0.46
9.04
1.25
1.13
0.02
—
0.34
0.87
0.78
0.32
0.17
43.92
0.02
0.03
0.03
0.04
0.01
0.02
0.01
0.01
0.31
0.35
0.03
O.01
O.01
O.01
to
o
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 20-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Oklahoma (Continued)
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Tulsa, Oklahoma (TUOK) Site #3 - Census Tract ID 40143003200
Acetaldehyde
Acrolein
Acrylonitrile
Arsenic (TSP)
Benzene
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
Formaldehyde
Manganese (TSP)
Nickel (TSP)
Tetrachloroethylene
Trichloroethylene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.000015
0.000011
5.5E-09
—
0.00016
0.000005
0.000002
0.009
0.00002
0.002
0.00003
0.03
0.002
0.04
0.8
0.0098
0.00005
0.000065
0.27
0.6
1.58
0.11
0.01
0.01
1.79
0.18
0.21
0.03
1.47
0.01
0.01
0.21
0.10
3.50
—
0.02
0.08
13.94
5.27
3.13
0.32
0.01
—
0.18
1.26
0.19
0.17
5.43
0.01
0.01
0.05
0.08
0.01
O.01
0.15
0.02
0.01
0.01
O.01
2.15 ±0.24
1.05 ±0.19
0.05 ±0.01
0.01 ±0.01
1.29 ±0.14
0.10 ±0.02
0.57 ±0.03
0.13 ±0.02
3.27 ±0.40
0.02 ±0.01
0.01 ±0.01
0.37 ±0.10
0.10 ±0.03
4.30
—
3.12
8.64
9.02
2.97
8.54
1.38
0.02
—
0.24
1.84
0.21
0.24
52.49
0.02
0.07
0.04
0.05
0.01
O.01
0.33
0.40
0.02
0.01
O.01
to
o
Bold = pollutant of interest
- = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Observations for CNEP from Table 20-8 include the following:
• With the exception of acrolein and acrylonitrile, the modeled concentrations of the
pollutants of interest were fairly similar to the annual averages. The annual average
of acrolein was higher by two orders of magnitude. The annual average of
acrylonitrile was higher by three orders of magnitude.
• The cancer risk estimates from NATA for some pollutants, such as benzene, were
very similar to the cancer risk approximations, but very different for others, such as
acrylonitrile.
• None of the pollutants had noncancer HQs greater than 1.0 according to NATA,
although acrolein was close (0.94). By contrast, acrolein's noncancer risk
approximation was 75.85. This is the second highest noncancer risk approximation
among program sites sampling acrolein (PXSS had the highest noncancer risk
approximation for acrolein).
Observations for the Tulsa sites from Table 20-8 include the following:
• Benzene, formaldehyde, and acetaldehyde had the highest modeled concentrations
and annual averages of all the pollutants failing at least one screen at the Tulsa sites.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadiene and acetaldehyde, while benzene, carbon tetrachloride, and arsenic had the
highest cancer risk approximations.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein. The same is true for the noncancer risk approximations, although the cancer
risk approximations were higher by an order of magnitude.
20.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 20-9 and 20-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 20-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million,) as calculated from the annual averages. Table 20-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
20-35
-------
Table 20-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Oklahoma
to
o
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Pryor, Oklahoma (CNEP) - Mayes County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Naphthalene
Dichloromethane
Hexavalent Chromium
POM, Group 1
Trichloroethylene
Chloromethylbenzene
72.35
57.48
9.36
5.71
5.19
3.46
2.05
1.99
1.85
1.40
Arsenic, PM
Hexavalent Chromium
Benzene
Cadmium, PM
Naphthalene
1,3 -Butadiene
POM, Group 1
Nickel, PM
Chloromethylbenzene
POM, Group 2
3.88E-03
2.81E-03
5.64E-04
1.94E-04
1.76E-04
1.71E-04
1.10E-04
9.64E-05
6.86E-05
5.81E-05
Carbon Tetrachloride
Benzene
Acrylonitrile
1 ,2-Dichloroethane
1,3 -Butadiene
9.69
3.32
1.78
1.12
0.83
Tulsa, Oklahoma, Site #1 (TOOK) - Tulsa County
Benzene
Formaldehyde
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Trichloroethylene
Naphthalene
£>-Dichlorobenzene
POM, Group 2
725.16
244.82
95.56
85.75
84.18
24.18
22.29
18.52
12.21
3.04
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Tetrachloroethylene
Acetaldehyde
Arsenic, PM
POM, Group 2
£>-Dichlorobenzene
Ethylene oxide
5.66E-03
2.53E-03
2.19E-03
6.30E-04
5.64E-04
.89E-04
.79E-04
.67E-04
.34E-04
.22E-04
Benzene
Carbon Tetrachloride
Arsenic
Acetaldehyde
1,3 -Butadiene
Acrylonitrile
/>-Dichlorobenzene
Tetrachloroethylene
Cadmium
Nickel
14.33
8.54
4.40
3.81
2.61
2.49
1.29
1.06
0.53
0.30
-------
Table 20-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Oklahoma (Continued)
to
o
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Tulsa, Oklahoma, Site #2 (TSOK) - Tulsa County
Benzene
Formaldehyde
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Trichloroethylene
Naphthalene
£>-Dichlorobenzene
POM, Group 2
725.16
244.82
95.56
85.75
84.18
24.18
22.29
18.52
12.21
3.04
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Tetrachloroethylene
Acetaldehyde
Arsenic, PM
POM, Group 2
£>-Dichlorobenzene
Ethylene oxide
5.66E-03
2.53E-03
2.19E-03
6.30E-04
5.64E-04
.89E-04
.79E-04
.67E-04
.34E-04
.22E-04
Carbon Tetrachloride
Benzene
Arsenic
Acrylonitrile
Acetaldehyde
1,3 -Butadiene
£>-Dichlorobenzene
1 ,2-Dichloroethane
Tetrachloroethylene
1,1,2-Trichloroethane
9.04
6.95
3.92
3.35
3.14
2.10
1.25
1.14
0.87
0.78
Tulsa, Oklahoma, Site #3 (TUOK) - Tulsa County
Benzene
Formaldehyde
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Trichloroethylene
Naphthalene
£>-Dichlorobenzene
POM, Group 2
725.16
244.82
95.56
85.75
84.18
24.18
22.29
18.52
12.21
3.04
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Tetrachloroethylene
Acetaldehyde
Arsenic, PM
POM, Group 2
£>-Dichlorobenzene
Ethylene oxide
5.66E-03
2.53E-03
2.19E-03
6.30E-04
5.64E-04
.89E-04
.79E-04
.67E-04
.34E-04
.22E-04
Benzene
Arsenic
Carbon Tetrachloride
Acetaldehyde
Acrylonitrile
1,3 -Butadiene
Tetrachloroethylene
/>-Dichlorobenzene
Nickel
Trichloroethylene
9.02
8.64
8.54
4.30
3.10
2.97
1.84
1.38
0.24
0.21
-------
Table 20-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Oklahoma
to
o
oo
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Pryor, Oklahoma (CNEP) - Mayes County
Toluene
Xylenes
Benzene
Hydrochloric acid
Methanol
Formaldehyde
Ethylene glycol
Hexane
Ethylbenzene
Styrene
148.70
99.56
72.35
61.44
58.81
57.48
25.75
23.69
23.49
12.98
Acrolein
Arsenic, PM
Manganese, PM
Nickel, PM
Formaldehyde
Cadmium, PM
Hydrochloric acid
1,3 -Butadiene
Mercury, PM
Benzene
82,589.42
30,049.69
20,652.70
9,274.01
5,865.21
5,391.68
3,072.04
2,856.93
2,650.63
2,411.52
Acrolein
Carbon Tetrachloride
Benzene
1,3 -Butadiene
Acrylonitrile
1 ,2-Dichloroethane
75.85
0.02
0.02
0.01
0.01
<0.01
Tulsa, Oklahoma, Site #1 (TOOK) - Tulsa County
Toluene
Xylenes
Benzene
Hexane
Methanol
Ethylbenzene
Formaldehyde
Methyl isobutyl ketone
Tetrachloroethylene
Ethylene glycol
1,860.89
1,246.17
725.16
319.06
315.40
304.55
244.82
132.35
95.56
91.93
Acrolein
Manganese, PM
1,3 -Butadiene
Formaldehyde
Benzene
Xylenes
Nickel, PM
Acetaldehyde
Cyanide Compounds, gas
Naphthalene
697,881.56
44,623.75
42,091.36
24,981.83
24,172.15
12,461.74
10,466.38
9,528.27
7,120.10
6,172.03
Acrolein
Manganese
Formaldehyde
Acetaldehyde
Benzene
1,3 -Butadiene
Arsenic
Nickel
Acrylonitrile
Cadmium
44.30
0.60
0.31
0.21
0.07
0.04
0.03
0.03
0.02
0.01
-------
Table 20-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Oklahoma (Continued)
to
o
vo
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Tulsa, Oklahoma, Site #2 (TSOK) - Tulsa County
Toluene
Xylenes
Benzene
Hexane
Methanol
Ethylbenzene
Formaldehyde
Methyl isobutyl ketone
Tetrachloroethylene
Ethylene glycol
1,860.89
1,246.17
725.16
319.06
315.40
304.55
244.82
132.35
95.56
91.93
Acrolein
Manganese, PM
1,3 -Butadiene
Formaldehyde
Benzene
Xylenes
Nickel, PM
Acetaldehyde
Cyanide Compounds, gas
Naphthalene
697,881.56
44,623.75
42,091.36
24,981.83
24,172.15
12,461.74
10,466.38
9,528.27
7,120.10
6,172.03
Acrolein
Manganese
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Benzene
Nickel
Arsenic
Acrylonitrile
Carbon Tetrachloride
43.92
0.35
0.31
0.17
0.04
0.03
0.03
0.03
0.02
0.02
Tulsa, Oklahoma, Site #3 (TUOK) - Tulsa County
Toluene
Xylenes
Benzene
Hexane
Methanol
Ethylbenzene
Formaldehyde
Methyl isobutyl ketone
Tetrachloroethylene
Ethylene glycol
1,860.89
1,246.17
725.16
319.06
315.40
304.55
244.82
132.35
95.56
91.93
Acrolein
Manganese, PM
1,3 -Butadiene
Formaldehyde
Benzene
Xylenes
Nickel, PM
Acetaldehyde
Cyanide Compounds, gas
Naphthalene
697,881.56
44,623.75
42,091.36
24,981.83
24,172.15
12,461.74
10,466.38
9,528.27
7,120.10
6,172.03
Acrolein
Manganese
Formaldehyde
Acetaldehyde
Arsenic
1,3 -Butadiene
Benzene
Acrylonitrile
Nickel
Carbon Tetrachloride
52.49
0.40
0.33
0.24
0.07
0.05
0.04
0.02
0.02
0.01
-------
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 20.3, TOOK, TSOK, and
TUOK sampled for VOC, carbonyls, and metals (TSP), while CNEP sampled for VOC only. In
addition, the cancer and noncancer risk approximations are limited to those sites sampling for a
long enough period for annual averages to be calculated. The Oklahoma sites sampled year-
round for each pollutant group mentioned above.
Observations from Table 20-9 include the following:
• Benzene and formaldehyde were the highest emitted pollutants with cancer UREs in
both Mayes and Tulsa County. The benzene emissions for Tulsa County were almost
exactly 10 times higher than the benzene emissions for Mayes County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) for Mayes County were arsenic and hexavalent chromium, while the
pollutants with the highest toxicity-weighted emissions for Tulsa County were
benzene and 1,3-butadiene.
• Six of the highest emitted pollutants in Mayes County also had the highest toxicity-
weighted emissions. Hexavalent chromium was the pollutant with the seventh
highest emissions in Mayes County. For no other county with a monitoring site did
hexavalent chromium appear on the list of highest emissions. This suggests that the
overall emissions may be rather low in Mayes County. Conversely, of the 41
counties with monitoring sites with hexavalent chromium emissions reported to the
NEI, the Mayes County emissions ranked seventh highest.
• Seven of the highest emitted pollutants in Tulsa County also had the highest toxicity-
weighted emissions.
• Carbon tetrachloride had the highest surrogate cancer risk approximation for CNEP.
This pollutant did not appear on either emissions-based list. However, benzene and
1,3-butadiene appear on all three lists.
• Benzene, arsenic, and carbon tetrachloride had the highest surrogate cancer risk
approximations for the Tulsa sites. Similar to CNEP, carbon tetrachloride did not
appear on either emissions-based list.
• Six pollutants (benzene, 1,3-butadiene, acetaldehyde, arsenic,/?-dichlorobenzene, and
tetrachloroethylene) were among the highest cancer risk approximations for all three
Tulsa sites and appear on the list of highest toxicity-weighted emissions. Five
pollutants (benzene, 1,3-butadiene, acetaldehyde,/>-dichlorobenzene, and
20-40
-------
tetrachloroethylene) were among the highest cancer risk approximations for all three
Tulsa sites and appear on the list of highest emitted pollutants.
Observations from Table 20-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Mayes and Tulsa County, although the magnitude of the emissions is much
higher in Tulsa County.
• The pollutant with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) for both counties was acrolein.
• Three of the highest emitted pollutants in both counties also have the highest toxicity-
weighted emissions (although the actual pollutants varied in each county).
• The pollutant with the highest noncancer risk approximation was acrolein for all four
sites. Acrolein was also the pollutant with the highest toxicity-weighted emissions,
but ranked 14th for total emissions for Tulsa County and 35th for Mayes County.
20.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Oklahoma monitoring site were acrolein,
benzene, 1,3-butadiene, and carbon tetrachloride.
»«» Acrolein had the highest daily average concentration for CNEP, while formaldehyde
had the highest daily average concentration for the Tulsa sites.
»«» The seasonal average concentrations of acrolein exceeded the intermediate MRL
health benchmark for all four sites.
20-41
-------
21.0 Sites in Puerto Rico
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the UATMP sites in Puerto Rico, and integrates these concentrations
with emissions, meteorological, and risk information.
21.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. The BAPR and SJPR
monitoring sites are located in the San Juan-Caguas-Guaynabo, PR MSA. Figures 21-1 and 21-2
are composite satellite images retrieved from Google™ Maps showing the monitoring sites in
their rural and urban locations. Figures 21-3 and 21-4 identify point source emission locations
within 10 miles of each site as reported in the 2002 NEI for point sources. Table 21-1 describes
the area surrounding each monitoring site and provides supplemental geographical information
such as land use, location setting, and locational coordinates.
BAPR is located on the west side of the Barceloneta Municipio, west of San Juan. This
location is only two miles from the north coast of Puerto Rico. The site is located in a residential
neighborhood, although the surrounding area is primarily rural, as shown in Figure 21-1. Major
roadways through the area lie on either side of the monitoring site, with Highway 22 (Autopisto
Jose de Diego) to the north and State Road 2 to the south. The point sources within 10 miles of
BAPR are located roughly within two miles of the coast, with most of them located along a line
running east-west along State Road 2 and Highway 22. Several pharmaceutical plants are
located just east of the monitoring site, as indicated in Figure 21-3.
SJPR is located in the southeast corner of the Regional Jail of Bayamon property. This
location is southwest of the city of San Juan and the Bay of San Juan (Bahia de San Juan).
According to officials for Puerto Rico, the San Juan metro area is one of the most polluted areas
on the island, and there is a concern about the respiratory disease incidence in the area. As
Figure 21-2 shows, the surrounding area is industrial and suburban, with residential areas nearby.
Highway 22 to the north and Highway 5 to the east intersect about a half mile northeast of the
21-1
-------
Figure 21-1. Barceloneta, Puerto Rico (BAPR) Monitoring Site
to
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 21-2. San Juan, Puerto Rico (SJPR) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 21-3. NEI Point Sources Located Within 10 Miles of BAPR
Note: Due to facility density and collocation, the total facilities
displayed may not represent all facilities within the area of interest.
Legend
"fa BAPR UATMP site
Q 10 mile radius
~~| County boundary
Source Category Group (No. of Facilities)
* Agricultural Chemicals Production Industrial Facility (1)
; Business Services Facility (1)
c Chemicals & Allied Products Facility (2)
F Fuel Combustion Industrial Facility (1)
> Pharmaceutical Production Processes Industrial Facility (10)
Q Primary Metal Industries Facility (1)
21-4
-------
Figure 21-4. NEI Point Sources Located Within 10 Miles of SJPR
San Juan
County ,Tr«j*j
.; AN* I
Coin
Legend
& SJPR UATMP site
•" • 10 mile radius
~] County boundary
Source Category Group (No. of Facilities)
C Chemicals & Allied Products Facility (1)
D Fabricated Metal Products Facility (3)
F Fuel Combustion Industrial Facility (2)
L Liquids Distribution Industrial Facility (5)
P Miscellaneous Processes Industrial Facility (1)
P Petroleum/Nat. Gas Prod. & Refining Industrial Facility (1)
4 Production of Organic Chemicals Industrial Facility (1)
U Stone, Clay. Glass, 8 Concrete Products (1)
Note: Due to facility density and collocation, the total facilities
displayed may not represent all facilities within the area of interest.
21-5
-------
Table 21-1. Geographical Information for the Puerto Rico Monitoring Sites
Site
Code
BAPR
SJPR
AQS Code
72-017-0003
72-021-0006
Location
Barceloneta
San Juan
County
Barceloneta
Bayamon
Micro- or
Metropolitan
Statistical Area
San Juan-Caguas-
Guaynabo, PR
San Juan-Caguas-
Guaynabo, PR
Latitude
and
Longitude
18.434444,
-66.579444
18.416944,
-66.148056
Land Use
Residential
Industrial
Location
Setting
Rural
Suburban
Description of the
Immediate Surroundings
The Barceloneta site is a residential area surrounded
by 5 pharmaceutical plants. The greater area outside
the city is rural in character and the city itself is
within 2 miles of the Atlantic Ocean.
The San Juan site is located at Bayamon Municipio,
in the Regional Jail. The San Juan Metropolitan
Area (S JMA) is affected by the emissions from
stationary sources and by the heavy daily traffic.
This geographical area is one of the Island's most
polluted areas. The selected location is an open area
representing a neighborhood scale in which the
industrial area merges with the residential areas.
The incidence of respiratory diseases is one of the
general concerns (for the community and for the
government). In general, the concentrations for the
criteria pollutants are under the standards. But air
toxics were not sampled for previously.
to
-------
site. An industrial park and Fort Buchanan reside to the east of Highway 5. Of the fifteen point
sources located within 10 miles of SJPR, liquids distribution facilities are the most numerous.
However, facilities involved in fabricated metal production are located in closest proximity to the
monitoring site, as Figure 21-4 shows.
Table 21-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Puerto
Rico monitoring sites. County-level vehicle registration and population data for the municipios
of Barceloneta and Bayamon were obtained from Air Monitoring Division of Puerto Rico's Air
Quality Program and the U.S. Census Bureau. Table 21-2 also includes a vehicle registration to
county population ratio (vehicles per person). In addition, the population within 10 miles of each
site is presented. An estimate of 10-mile vehicle registration was calculated by applying the
county-level vehicle registration to population ratio to the 10-mile population surrounding the
monitoring site. Table 21-2 also contains annual average daily traffic information, as well as the
year of the traffic data estimate and the source from which it was obtained. Finally, Table 21-2
presents the daily VMT for each urban area.
Table 21-2. Population, Motor Vehicle, and Traffic Information for the Puerto Rico
Monitoring Sites
Site
BAPR
SJPR
2007
Estimated
County
Population
23,038
220,574
Number
of
Vehicles
Registered
13,912
145,642
Vehicles
per Person
(Registration:
Population)
0.60
0.66
Population
Within
10 Miles
NA
NA
Estimated
10 mile Vehicle
Ownership
—
-
Annual
Average
Traffic
Data1
48,400
139,563
VMT
(thousands)
32,364
32,364
Daily Average Traffic Data reflects 2004 data from the Puerto Rico Highway & Transportation Authority (BAPR)
and 2003 data from the Puerto Rico Highway & Transportation Authority (SJPR)
Observations from Table 21-2 include the following:
• The county-level population and vehicle ownership were an order of magnitude
higher for SJPR compared to BAPR. The county-level population for BAPR was the
second lowest compared to data for other monitoring sites and the vehicle ownership
for BAPR was the lowest of all other monitoring sites. The county-level population
and vehicle ownership for SJPR were also on the low side compared to other
monitoring sites.
21-7
-------
• The vehicle registration to population ratios were fairly similar and on the low side
compared to other monitoring sites.
• The population within 10 miles was not available for the Puerto Rico sites. As such,
a 10-mile vehicle ownership estimate could be not calculated.
• Traffic values were on the high end of the range for these sites. Traffic for SJPR
ranked eighth and traffic for BAPR ranked 17th highest among other monitoring sites.
Traffic for BAPR was obtained from Highway 22 at State Road 140; traffic for SJPR
was obtained from Highway 22 between State Roads 869 and 5.
21.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Puerto Rico on sampling days, as well as over the course of the year.
21.2.1 Climate Summary
The island of Puerto Rico is located in the northern Caribbean and experiences a tropical
climate, where the air is warm and humid year-round and rainfall is abundant. Breezy winds
flow from the northeast to east on average with the aid of the sub-tropical high pressure that
resides over the tropical Atlantic Ocean. However, the sea-breeze is a daily occurrence (Ruffner
andBair, 1987).
21.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station to BAPR and SJPR is located at Luis Munoz Marin International Airport
(WB AN 11641).
Table 21-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 21-3 is the 95 percent
21-8
-------
Table 21-3. Average Meteorological Conditions near the Puerto Rico Monitoring Sites
Site
BAPR
SJPR
Closest NWS
Station and
WBAN
San Juan, PR
Luis Munoz
Marin Intl
Airport
11641
San Juan, PR
Luis Munoz
Marin Intl
Airport
11641
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
85.87
±1.35
86.27
±0.35
85.86
±1.39
86.27
±0.35
Average
Temperature
(op)
79.35
±0.97
80.26
±0.27
79.38
±1.01
80.26
±0.27
Average
Dew Point
Temperature
(°F)
69.82
±0.88
70.98
±0.27
69.87
±0.91
70.98
±0.27
Average
Wet Bulb
Temperature
(»F)
72.94
±0.78
73.96
±0.23
72.98
±0.80
73.96
±0.23
Average
Relative
Humidity
(%)
73.54
± 1.89
74.20
±0.51
73.61
±1.96
74.20
±0.51
Average
Sea Level
Pressure
(mb)
1015.82
±0.75
1015.12
±0.22
1015.86
±0.77
1015.12
±0.22
Average
Scalar Wind
Speed
(kt)
6.54
±0.78
6.70
±0.24
6.58
±0.80
6.70
±0.24
to
-------
confidence interval for each parameter. As shown in Table 21-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year. Even though the sites stopped sampling in June, the weather conditions on sampling
days during the first half of the year were likely similar to weather conditions experienced during
the second half of the year, which is reflected in the similarity of the averages in Table 21-3.
21.2.3 Composite Back Trajectories for Sampling Days
Figures 21-5 and 21-6 are composite back trajectory maps for the Puerto Rico monitoring
sites for the days on which samples were collected. Each line represents the 24-hour trajectory
along which a parcel of air traveled toward the monitoring site on a sampling day. Each
concentric circle around the sites in Figures 21-5 and 21-6 represents 100 miles.
Observations from Figures 21-5 and 21-6 include the following:
• The back trajectory maps for BAPR and SJPR are similar to each other.
• Back trajectories originated from the northeast, east, and southeast. Back trajectories
did not originate from any other direction.
• The 24-hour air shed domains were somewhat smaller for these sites than for other
monitoring sites. The furthest away a trajectory originated was nearly 500 miles
away. However, most trajectories originated within 400 miles of the sites.
21.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather station closest to BAPR and SJPR were uploaded into
a wind rose software program, WRPLOT (Lakes, 2006) to produce customized wind roses. A
wind rose shows the frequency of wind directions on a 16-point compass, and uses different
shading to represent wind speeds. Figures 21-7 and 21-8 are the wind roses for the Puerto Rico
monitoring sites on days that samples were collected.
Observations from Figures 21-7 and 21-8 include the following:
• The wind roses for BAPR and SJPR are very similar to each other. This is expected
because the same weather station was used for both sites and because the dates of
sampling were very similar.
21-10
-------
Figure 21-5. Composite Back Trajectory Map for BAPR
to
-^
I
\
0 25 50 100 150 200
I Miles
-------
Figure 21-6. Composite Back Trajectory Map for SJPR
to
—1
I
K^
to
200
Miles
-------
Figure 21-7. Wind Rose for BAPR Sampling Days
Figure 21-8. Wind Rose for SJPR Sampling Days
WEST:
21-13
-------
• Easterly and southeasterly winds were prevalent near these sites. Winds with a
westerly component were not observed on sampling days.
• Calm winds were observed for nearly 20 percent of the hourly measurements.
21.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Puerto
Rico monitoring sites were identified using the EPA risk screening process described in Section
3.2. In brief, each pollutant's measured concentration was compared to its associated risk
screening value. If the daily concentration was greater than the risk screening value, then the
measured concentration "failed the screen." Pollutants of interest are those for which the
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 21-4 presents the pollutants that failed at least one screen for each Puerto Rico
monitoring site and highlights each site's pollutants of interest (shaded). Both sites sampled for
VOC and carbonyl compounds.
Observations from Table 21-4 include the following:
• Eleven pollutants with a total of 217 measured concentrations failed at least one
screen for BAPR; thirteen pollutants with a total of 225 measured concentrations
failed screens for SJPR.
• The pollutants of interest were very similar for both sites. The following pollutants of
interest were common to both sites: acetaldehyde, acrolein, benzene, 1,3-butadiene,
carbon tetrachloride, formaldehyde, and/>-dichlorobenzene. Only one pollutant of
interest was different between the sites. Dichloromethane was a pollutant of interest
for BAPR while tetrachloroethylene was a pollutant of interest for SJPR. BAPR was
the only monitoring site for which dichloromethane was a pollutant of interest.
• Of the seven common pollutants of interest, 100 percent of the measured detections of
acrolein, benzene, 1,3-butadiene, and carbon tetrachloride failed screens for BAPR
and SJPR.
• Of the pollutants with at least one failed screen, 83 percent of measurements failed
screens for BAPR, while 64 percent failed screens for SJPR.
21-14
-------
Table 21-4. Comparison of Measured Concentrations and EPA Screening Values for the
Puerto Rico Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Barceloneta, Puerto Rico - BAPR
Acrolein
Carbon Tetrachloride
Benzene
1,3 -Butadiene
Acetaldehyde
£>-Dichlorobenzene
Dichloromethane
Formaldehyde
Acrylonitrile
Hexachloro- 1 ,3 -butadiene
Tetrachloroethylene
Total
30
30
30
30
28
27
23
13
4
1
1
217
30
30
30
30
29
30
30
29
4
1
17
260
100.00
100.00
100.00
100.00
96.55
90.00
76.67
44.83
100.00
100.00
5.88
83.46
13.82
13.82
13.82
13.82
12.90
12.44
10.60
5.99
1.84
0.46
0.46
13.82
27.65
41.47
55.30
68.20
80.65
91.24
97.24
99.08
99.54
100.00
San Juan, Puerto Rico - SJPR
1,3 -Butadiene
Acetaldehyde
Acrolein
Benzene
Carbon Tetrachloride
Formaldehyde
£>-Dichlorobenzene
Tetrachloroethylene
Dichloromethane
Xylenes
Acrylonitrile
Bromomethane
Toluene
Total
29
29
29
29
29
29
28
13
4
2
2
1
1
225
29
29
29
29
29
29
29
29
29
29
2
29
29
350
100.00
100.00
100.00
100.00
100.00
100.00
96.55
44.83
13.79
6.90
100.00
3.45
3.45
64.29
12.89
12.89
12.89
12.89
12.89
12.89
12.44
5.78
1.78
0.89
0.89
0.44
0.44
12.89
25.78
38.67
51.56
64.44
77.33
89.78
95.56
97.33
98.22
99.11
99.56
100.00
21.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Puerto Rico monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
21-15
-------
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
21.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 21-5.
Observations for BAPR from Table 21-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
dichloromethane (7.53 ± 4.77 |ig/m3), acetaldehyde (1.95 ± 0.35 |ig/m3), and
formaldehyde (0.97 ± 0.10 |ig/m3). The concentrations of dichloromethane were
significantly higher than any other pollutant of interest.
• As shown in Table 4-11, of the program-level pollutants of interest, BAPR had the
fourth highest daily average concentration ofp-dichlorobenzene. In addition, the
BAPR daily average concentrations of 1,3-butadiene and carbon tetrachloride were
among the 10 highest average concentrations for all NATTS and UATMP sites.
However, concentrations of carbon tetrachloride are fairly uniform across the sites
and the value for 1,3-butadiene is relatively low.
• Seasonal averages could only be calculated for winter and spring and annual averages
were not calculated because BAPR stopped sampling in June.
Observations for SJPR from Table 21-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
acetaldehyde (6.35 ± 1.99 |ig/m3), formaldehyde (2.29 ± 0.21 |ig/m3), and benzene
(1.48 ± 0.22 |ig/m3). The daily average concentrations of these pollutants were all
higher than the daily average concentrations for BAPR.
21-16
-------
Table 21-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Puerto Rico Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Hg/m3)
Winter
Average
(jig/m3)
Spring
Average
(jig/m3)
Summer
Average
(Hg/m3)
Autumn
Average
(jig/m3)
Annual
Average
(jig/m3)
Barceloneta, Puerto Rico - BAPR
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Dichloromethane
Formaldehyde
29
30
30
30
30
30
30
29
29
30
30
30
30
30
30
29
1.95
±0.35
0.87
±0.23
0.93
±0.14
0.12
±0.02
0.62
±0.04
0.31
±0.12
7.53
±4.77
0.97
±0.10
1.81
±0.58
1.06
±0.53
1.15
±0.32
0.14
±0.03
0.55
±0.05
0.41
±0.31
6.96
±6.14
0.76
±0.12
2.28
±0.51
0.80
±0.26
0.83
±0.13
0.12
±0.02
0.66
±0.06
0.27
±0.12
8.77
±8.17
1.10
±0.14
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
San Juan, Puerto Rico - SJPR
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
29
29
29
29
29
29
29
29
29
29
29
29
29
29
29
29
6.35
±1.99
0.72
±0.16
1.48
±0.22
0.17
±0.03
0.68
±0.05
0.40
±0.08
2.29
±0.21
0.21
±0.06
8.64
±5.89
0.71
±0.19
1.49
±0.55
0.19
±0.07
0.57
±0.04
0.46
±0.22
1.81
±0.36
0.28
±0.13
5.41
±0.90
0.67
±0.20
1.48
±0.23
0.17
±0.03
0.75
±0.07
0.39
±0.07
2.59
±0.19
0.19
±0.07
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
• As shown in Tables 4-9 and 4-11, of the program-level pollutants of interest, SJPR
had the highest daily average concentration of acetaldehyde and/>-dichlorobenzene.
In addition, the SJPR daily average concentrations of 1,3-butadiene and benzene were
among the 10 highest average concentrations for all NATTS and UATMP sites.
• Seasonal averages could only be calculated for winter and spring and annual averages
were not calculated because SJPR stopped sampling in June.
21-17
-------
21.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. Although BAPR has sampled under the National Monitoring
Program since 2001, a lapse in sampling occurred in 2004. SJPR began sampling in 2005 as part
of the National Monitoring Program. Therefore, the trends analysis was not conducted for these
sites.
21.5 Pearson Correlations
Table 21-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations from Table 21-6 include the following:
• Nearly all of the correlations between the pollutants of interest for BAPR and SJPR
and the meteorological parameters were weak.
• However, strong positive correlations were calculated between formaldehyde and
maximum temperature for both sites, indicating that as temperatures increase,
concentrations of formaldehyde increase. Although this was also true for average
temperature for BAPR, the correlation between average temperature and
formaldehyde for SJPR was weaker than for BAPR.
• While the pollutants of interest exhibited weak correlations with wind speed, nearly
all were negative, suggesting that concentrations of the pollutants of interest may
increase as wind speeds decrease.
21.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
21-18
-------
Table 21-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Puerto
Rico Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Barceloneta, Puerto Rico - BAPR
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
Dichloromethane
Formaldehyde
29
30
30
30
30
30
30
29
0.15
-0.13
-0.04
-0.06
0.25
-0.25
-0.02
0.58
-0.07
-0.12
-0.09
-0.13
0.24
-0.19
-0.08
0.51
-0.33
0.05
-0.01
-0.05
0.15
-0.18
-0.06
0.12
-0.26
0.00
-0.05
-0.09
0.20
-0.19
-0.07
0.28
-0.27
0.20
0.11
0.11
-0.11
0.03
0.02
-0.45
0.01
-0.01
-0.03
-0.07
-0.12
0.04
-0.06
-0.24
-0.24
0.12
-0.24
-0.18
-0.03
0.17
-0.03
-0.25
San Juan, Puerto Rico - SJPR
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
29
29
29
29
29
29
29
29
-0.05
-0.01
-0.02
-0.03
0.29
-0.17
0.51
-0.18
-0.17
0.06
-0.08
-0.15
0.25
-0.22
0.33
-0.28
-0.14
-0.11
0.11
0.07
-0.13
-0.18
0.01
-0.04
-0.18
-0.06
0.04
-0.01
0.01
-0.22
0.14
-0.14
0.03
-0.22
0.21
0.27
-0.42
0.05
-0.36
0.29
-0.06
0.25
-0.14
-0.10
-0.22
-0.11
-0.22
-0.04
-0.39
0.17
-0.35
-0.42
-0.09
-0.36
-0.28
-0.40
-------
21.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data for the Puerto Rico
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 21-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 21-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• The winter and spring seasonal averages of acrolein exceeded the intermediate MRL
for both sites.
• Acrolein has no chronic MRL. In addition, annual averages could not be calculated
for these two sites because they stopped sampling in June. Therefore, a chronic risk
comparison could not be conducted.
21.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Puerto Rico monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncaner risk estimates from NATA and calculating cancer and noncancer
surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an annual average
and how cancer and noncancer surrogate risk approximations are calculated). Concentration and
risk estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer
and noncancer surrogate risk approximations are presented in Table 21-8. The NATA data are
presented for the census tract where each monitoring site is located. The pollutants of interest
for each site are bolded.
21-20
-------
Table 21-7. MRL Risk Screening Assessment Summary for the Puerto Rico Monitoring Sites
Site
BAPR
SJPR
Method
TO-15
TO- 15
Pollutant
Acrolein
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/30
0/29
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
0.09
Winter
Average
(Ug/m3)
1.06
±0.53
0.71
±0.19
Spring
Average
(Ug/m3)
0.80
±0.26
0.67
±0.20
Summer
Average
(Ug/m3)
NA
NA
Autumn
Average
(Ug/m3)
NA
NA
ATSDR
Chronic
MRL
(Ug/m3)
—
-
Annual
Average
(Ug/m3)
NA
NA
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
BOLD = exceedance of the intermediate or chronic MRL
- = an MRL risk factor is not available
to
to
-------
Table 21-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Puerto Rico
Pollutant
Cancer
URE
(Hg/rn3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Barceloneta, Puerto Rico (BAPR) - Census Tract ID 72017590300
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
Dichloromethane
Formaldehyde
Hexachloro- 1 ,3 -butadiene
Tetrachloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000011
0.00000047
5.5E-09
0.000022
0.000005
0.009
0.00002
0.002
0.03
0.002
0.04
0.8
1
0.0098
0.09
0.27
0.26
0.13
0.01
2.10
0.13
0.69
0.06
151.02
1.01
0.01
0.24
0.59
—
0.01
16.40
3.78
10.34
0.61
70.99
0.01
0.03
1.44
0.03
6.41
0.01
0.07
0.06
0.01
O.01
0.15
0.10
0.01
0.01
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
to
to
- = a URE or RfC is not available
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
-------
Table 21-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Puerto Rico (Continued)
Pollutant
Cancer
URE
(Hg/rn3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
San Juan, Puerto Rico (SJPR) - Census Tract ID 72021030101
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
Bromomethane
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
Dichloromethane
Formaldehyde
Tetrachloroethylene
Toluene
Xylenes
0.000002
—
0.000068
0.000007
~
0.00003
0.000015
0.000011
0.00000047
5.5E-09
0.000005
—
-
0.009
0.00002
0.002
0.03
0.005
0.002
0.04
0.8
1
0.0098
0.27
0.4
0.1
0.35
0.19
0.01
3.38
0.23
0.19
0.69
0.07
1.11
1.20
0.40
7.51
5.06
0.78
—
0.02
26.38
~
5.64
10.37
0.81
0.54
0.01
2.36
—
-
0.03
9.50
0.01
0.11
0.04
0.09
0.01
O.01
0.01
0.12
0.01
0.02
0.05
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
to
- = a URE or RfC is not available
Bold = pollutant of interest
NA = Not available due to the duration criteria for calculating a seasonal and/or annual average
-------
The census tract information for the Puerto Rico monitoring sites is as follows:
• The census tract for BAPR is 72017590300, which had a population of 6,625, and
represented approximately 30 percent of the Barceloneta Municipio population in
2000.
• The census tract for SJPR is 72021030101, which had a population of 6,628, and
represented approximately 3 percent of the Bayamon Municipio population in 2000.
Observations for BAPR from Table 21-8 include the following:
• Dichloromethane had the highest modeled concentration and cancer risk, according to
NATA. The cancer risk for this pollutant (70.99 in-a-million) was the second highest
of all cancer risk estimates for any pollutant that failed a screen in a census tract with
a UATMP or NATTS monitoring site.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (6.41).
• Because annual averages could not be calculated, cancer and noncancer surrogate risk
approximations could not be calculated. Therefore, no additional comparisons can be
made.
Observations for SJPR from Table 21-8 include the following:
• The pollutants with the highest modeled concentrations according to NATA were
toluene, xylenes, and benzene. Of these, only benzene was a pollutant of interest.
• The pollutants with the highest cancer risks according to NATA were benzene,
carbon tetrachloride, and 1,3-butadiene.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (1.04).
• Because annual averages could not be calculated, cancer and noncancer surrogate risk
approximations could not be calculated. Therefore, no additional comparisons can be
made.
21.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 21-9 and 21-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 21-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
21-24
-------
Table 21-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Puerto Rico
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Barceloneta, Puerto Rico (BAPR) - Barceloneta Municipio
Dichloromethane
Benzene
Formaldehyde
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
Naphthalene
Hexavalent Chromium
Ethylene oxide
POM, Group 2
346.70
5.66
1.89
1.86
0.77
0.64
0.10
0.06
0.03
0.01
Hexavalent Chromium
Dichloromethane
Benzene
Arsenic, PM
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
Ethylene oxide
Cadmium, PM
Acetaldehyde
3.04E-04
1.63E-04
4.41E-05
4.30E-05
1.92E-05
1.10E-05
3.29E-06
2.69E-06
2.16E-06
1.70E-06
San Juan, Puerto Rico (SJPR) - Bayamon Municipio
Benzene
Formaldehyde
Tetrachloroethylene
Dichloromethane
1,3 -Butadiene
Acetaldehyde
Naphthalene
Hexavalent Chromium
Ethylene oxide
POM, Group 2
103.56
30.81
22.09
16.97
11.22
10.88
2.17
0.65
0.27
0.25
Hexavalent Chromium
Benzene
Arsenic, PM
1,3 -Butadiene
Tetrachloroethylene
Naphthalene
Acetaldehyde
Ethylene oxide
POM, Group 2
Cadmium, PM
2.81E-03
8.08E-04
3.37E-04
3.37E-04
1.30E-04
7.39E-05
2.39E-05
2.34E-05
1.39E-05
1.33E-05
-------
Table 21-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Puerto Rico
to
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risks Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Barceloneta, Puerto Rico (BAPR) - Barceloneta Municipio
Dichloromethane
Acetonitrile
Toluene
Xylenes
Methanol
Benzene
Hexane
Ethylbenzene
Hydrochloric acid
Formaldehyde
346.70
29.95
21.40
13.29
12.28
5.66
3.53
3.32
2.00
1.89
Acrolein
Chlorine
Acetonitrile
Dichloromethane
Arsenic, PM
1,3 -Butadiene
Hexavalent Chromium
Formaldehyde
Benzene
Xylenes
4,637.93
2,150.02
499.09
346.70
333.56
319.29
253.27
192.87
188.55
132.89
San Juan, Puerto Rico (SJPR) - Bayamon Municipio
Toluene
Xylenes
Benzene
Hexane
Ethylbenzene
Formaldehyde
Methyl tert-butyl ether
Tetrachloroethylene
Dichloromethane
1,3 -Butadiene
310.52
177.15
103.56
91.70
46.08
30.81
30.12
22.09
16.97
11.22
Acrolein
1,3 -Butadiene
Benzene
Formaldehyde
Arsenic, PM
Hexavalent Chromium
Xylenes
Acetaldehyde
Nickel, PM
Toluene
70,207.29
5,609.11
3,451.96
3,143.77
2,613.70
2,344.77
1,771.47
1,208.41
1,012.43
776.30
-------
cancer surrogate risk approximations (in-a-million), as calculated from the annual averages.
Table 21-10 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 21.3, SJPR and BAPR sampled
for VOC and carbonyl compounds. In addition, the cancer and noncancer surrogate risk
approximations are limited to those sites sampling for a long enough period for an annual
averages to be calculated.
Observations from Table 21-9 include the following:
• Dichloromethane was the highest emitted pollutant with a cancer URE in Barceloneta
Municipio, followed by benzene and formaldehyde. Dichloromethane emissions
were higher than any other pollutant emitted in Barceloneta Municipio two orders of
magnitude.
• Benzene, formaldehyde, and tetrachloroethylene were the highest emitted pollutants
with cancer UREs in Bayamon Municipio.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) were hexavalent chromium, dichloromethane, and benzene in
Barceloneta Municipio. The pollutants with the highest toxicity-weighted emissions
(of the pollutants with cancer UREs) were hexavalent chromium, benzene, and
arsenic in Bayamon Municipio.
• Seven of the highest emitted pollutants also had the highest toxicity-weighted
emissions in Barceloneta Municipio and Bayamon Municipios.
• Because annual averages could not be calculated, cancer risk approximations could
not be calculated. Therefore, no additional comparisons can be made.
21-27
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Observations from Table 21-10 include the following:
• Dichloromethane was the highest emitted pollutant with a noncancer RfC in
Barceloneta Municipio, followed by acetonitrile and toluene. Again,
dichloromethane emissions were higher than any other pollutant emitted in
Barceloneta Municipio by an order of magnitude.
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Bayamon Municipio.
• The pollutant with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) in Barceloneta and Bayamon Municipios was acrolein.
• Five of the highest emitted pollutants also had the highest toxicity-weighted
emissions in Barceloneta Municipio and Bayamon Municipio.
• Because annual averages could not be calculated, cancer risk approximations could
not be calculated. Therefore, no additional comparisons can be made.
21.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Puerto Rico site were acetaldehyde,
acrolein, benzene, 1,3-butadiene, carbon tetrachloride, p-dichlorobenzene, and
formaldehyde.
»«» Acetaldehyde had the highest daily average concentration for SJPR, while
dichloromethane had the highest daily average concentration for BAPR.
»«» The winter and spring average concentrations of acrolein exceeded the intermediate
MRL health benchmark for both sites.
»«» Average concentrations of dichloromethane for BAPR were higher than other
program sites. However, an annual average concentration could not be calculated,
due to the short sampling duration, to provide a cancer risk approximation.
21-28
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22.0 Site in Rhode Island
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Rhode Island, and integrates these concentrations
with emissions, meteorological, and risk information.
22.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Rhode Island site is
located in the Providence-New Bedford-Fall River, RI-MA MSA. Figure 22-1 is a composite
satellite image retrieved from Google™ Maps showing the monitoring site in its urban location.
Figure 22-2 identifies point source emission locations within 10 miles of the site as reported in
the 2002 NEI for point sources. Table 22-1 describes the area surrounding the monitoring site
and provides supplemental geographical information such as land use, location setting, and
locational coordinates.
The PRRI monitoring site is located in south Providence. Figure 22-1 shows that the area
to the west and south is residential, but areas to the north and east are more commercial. A
hospital lies to the northeast, just north of Dudley Street. About a half-mile to the east, 1-95 runs
north-south, then turns northwestward, entering downtown Providence. Narragansett Bay and
the Port of Providence are just a few tenths of a mile further to the east, on the other side of 1-95.
Figure 22-2 shows that a large number of point sources are located within 10 miles of PRRI.
Some of the more numerous source categories include fuel combustion and surface coating
processing.
Table 22-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Rhode
Island monitoring site. County-level vehicle registration and population data for Providence
County were obtained from Rhode Island Data Control and the U.S. Census Bureau. Table 22-2
also includes a vehicle registration to county population ratio (vehicles per person). In addition,
the population within 10 miles of the site is presented. An estimate of 10-mile vehicle
22-1
-------
to
to
to
Figure 22-1. Providence, Rhode Island (PRRI) Monitoring Site
. -'
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 22-2. NEI Point Sources Located Within 10 Miles of PRRI
• '• *-Ti Pharmaceutical Production Processes Industrial Facility (2)
v Polymers S Ressns Production Industrial Facility {5)
o Primary Metal industries Facilrty (3)
* Produclion of Organic Chemicals Industrial Facility (2)
v Rubber & MisceHaneois Plastic Products Facility (4)
u Stone, Clay, Glass. S Concrete Products (2)
S Surface Coating Processes Industrial Facility (54)
8 Uftlrty Bailers (2)
'.-vsste Treatment a Disposal Industrial Facility (3)
' Wholesale Trade (2)
22-3
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Table 22-1. Geographical Information for the Rhode Island Monitoring Site
Site
Code
PRRI
AQS Code
44-007-0022
Location
Providence
County
Providence
Micro- or
Metropolitan
Statistical Area
Providence-New
Bedford-Fall
River, RI-MA
Latitude
and
Longitude
41.807949,
-71.415
Land Use
Residential
Location
Setting
Urban/City
Center
Description of the
Immediate Surroundings
The site is on the southern end of the roof of a rather
spread-out, 1 -story building in a fairly low-income
neighborhood of south-Providence. It's
approximately a half-mile from 1-95 where it makes a
sharp curve as it enters the city, where traffic
congestion is common. Narragansett Bay and the
Port of Providence are just a few tenths of a mile
further to the east, on the other side of the highway.
There is some industry along the Bay, including an
asphalt plant right next to the curve in the highway.
There is also a highway relocation project that's been
under way for a couple of years.
BOLD = EPA-designated NATTS Site
to
to
-------
Table 22-2. Population, Motor Vehicle, and Traffic Information for the Rhode Island
Monitoring Site
Site
PRRI
2007
Estimated
County
Population
629,435
Number
of
Vehicles
Registered
142,334
Vehicles
per Person
(Registration:
Population)
0.23
Population
Within
10 Miles
670,441
Estimated
10-mile
Vehicle
Ownership
151,607
Annual
Average
Traffic
Data1
212,100
VMT
(thousands)
26,744
1 Daily Average Traffic Data reflects 2006 data from the Rhode Island DOT
BOLD = EPA-designated NATTS Site
registration was calculated by applying the county-level vehicle registration to population ratio to
the 10-mile population surrounding the monitoring site. Table 22-2 also contains annual average
daily traffic information, as well as the year of the traffic data estimate and the source from
which it was obtained. Finally, Table 22-2 presents the daily VMT for the urban area.
Observations from Table 22-2 include the following:
• Providence County's population ranked 19th compared to all counties with NATTS
or UATMP sites and its 10-mile population ranked 21st.
• The county-level vehicle registration ranked 29th compared to all counties with
NATTS or UATMP sites, while its 10-mile ownership estimated ranked even lower.
• The vehicle per person ratio was the second lowest compared to other NATTS or
UATMP sites, second only to BXNY.
• The traffic volume experienced near PRRI ranked third highest compared to other
monitoring sites. The traffic estimate used came from 1-95 near exit 18.
• The Providence area VMT was in the middle of the range among urban areas with
UATMP or NATTS sites.
22.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Rhode Island on sampling days, as well as over the course of the year.
22.2.1 Climate Summary
Providence is a coastal city on the Narragansett Bay, which opens to the Rhode Island
Sound and the Atlantic Ocean. The city's proximity to the Sound and the Atlantic Ocean temper
cold air outbreaks, and breezes off the ocean moderate summertime heat. On average, southerly
22-5
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and southwesterly winds in the summer become northwesterly in the winter. Weather is fairly
variable in the region as frequent storm systems affect New England (Ruffner and Bair, 1987).
22.2.2 Meteorological Conditions in 2007
Hourly meteorological data at the weather station near the site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Theodore F. Green State Airport (WBAN 14765).
Table 22-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 22-3 is the 95 percent
confidence interval for each parameter. As shown in Table 22-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
22.2.3 Composite Back Trajectories for Sampling Days
Figure 22-3 is the composite back trajectory map for the Rhode Island monitoring site
for the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the site in Figure 22-3 represents 100 miles.
Observations from Figure 22-3 include the following:
• Back trajectories originated from a variety of directions at PRRI, although fewer
trajectories originated from the southeast.
• The 24-hour air shed domain for PRRI was similar in size to other monitoring sites.
The furthest away a trajectory originated was Newfoundland, Canada, or nearly 800
miles away. However, most trajectories originated within 500 miles of the site.
22-6
-------
Table 22-3. Average Meteorological Conditions near the Rhode Island Monitoring Site
Site
PRRI
Closest NWS
Station and
WBAN
Theodore F.
Green State
Airport
14765
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
59.89
±4.72
60.63
±1.96
Average
Temperature
(op)
51.91
±4.48
52.18
±1.82
Average
Dew Point
Temperature
(°F)
39.40
±5.07
38.59
±2.03
Average
Wet Bulb
Temperature
(»F)
46.35
±4.24
46.12
±1.69
Average
Relative
Humidity
(%)
65.11
±3.61
63.16
± 1.55
Average
Sea Level
Pressure
(mb)
1017.43
±1.75
1016.31
±0.79
Average
Scalar Wind
Speed
(kt)
7.59
±0.67
7.80
±0.29
BOLD = EPA-designated NATTS Site
to
to
-------
Figure 22-3. Composite Back Trajectory Map for PRRI
to
to
oo
-------
22.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at T. F. Green Airport near PRRI were
uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce customized
wind roses. A wind rose shows the frequency of wind directions on a 16-point compass, and
uses different shading to represent wind speeds. Figure 22-4 is the wind roses for the Rhode
Island monitoring site on days that samples were collected.
Observations from Figure 22-4 for PRRI include the following:
• Although winds from a variety of directions were observed near PRRI, westerly
winds were prevalent (15 percent of wind observations).
• Calm winds were observed for nearly eight percent of the hourly measurements.
• Winds exceeding 11 knots made up nearly 18 percent of observations. The strongest
winds originated from the west, northwest, and north.
Figure 22-4. Wind Rose for PRRI Sampling Days
I 2%
SOUTH .-'
EAST
WIND SPEED
(Knots)
• =22
^| 17 - 21
^| 11 - 17
^| 7- 11
n 1-7
• 2- 4
Calms: 7.70%
22-9
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22.3 Pollutants of Interest
"Pollutants of interest" were determined for the site in order to allow analysts and readers
to focus on a risk-based subset of pollutants. The pollutants of interest for the Rhode Island
monitoring site were identified using the EPA risk screening process described in Section 3.2. In
brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 22-4 presents the pollutants that failed at least one screen for the Rhode Island monitoring
site and highlights the site's pollutants of interest (shaded).
Observations from Table 22-4 include the following:
• PRRI sampled for hexavalent chromium only.
• Hexavalent chromium was detected in 37 samples and failed two screens. This
represents a five percent failure rate.
Table 22-4. Comparison of Measured Concentrations and EPA Screening Values for the
Rhode Island Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Providence, Rhode Island - PRRI
Hexavalent Chromium
Total
2
2
37
37
5.41
5.41
100.00
100.00
22.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Rhode Island monitoring site. The averages presented are provided for the pollutant of
interest for the site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the site, where applicable.
22-10
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22.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for hexavalent
chromium, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 22-5. The averages
presented in Table 22-5 are shown in ng/m3 for ease of viewing.
Observations for PRRI from Table 22-5 include the following:
• The daily average concentration of hexavalent chromium was higher than the annual
average (0.022 ± 0.011 ng/m3 vs. 0.015 ± 0.007 ng/m3), which illustrates the effect of
the substitution of 1/2 MDL. However, the confidence interval indicates that the
difference is not statistically significant.
• The summer average concentration of hexavalent chromium was higher than the
spring and autumn averages. However, the confidence interval indicates that the
summer average is affected by outliers.
• A winter average could not be calculated due to the low number of detections (less
than seven).
Table 22-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Rhode Island Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average1
(ng/m3)
Providence, Rhode Island -PRRI
Hexavalent Chromium
37
60
0.022
±0.011
NR
0.015
±0.012
0.028
± 0.025
0.012
± 0.004
0.015
± 0.007
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
22-11
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22.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. PRRI has not sampled continuously for five years as part of the
National Monitoring Programs; therefore, the trends analysis was not conducted.
22.5 Pearson Correlations
Table 22-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between the concentrations of hexavalent chromium and
select meteorological parameters. (Refer to Section 3.4 for more information on Pearson
correlations.)
Observations for PRRI from Table 22-6 include the following:
• All of the correlations for PRRI were weak.
22.6 Additional Risk Screening Evaluations
The following evaluations were conducted to characterize risk at the monitoring site.
Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the various risk factors,
time frames, and calculations associated with risk.
22.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Rhode
Island monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available.
As described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of hexavalent chromium were compared to the
acute MRL; the seasonal averages were compared to the intermediate MRL; and the annual
averages were compared to the chronic MRL. None of the concentrations measured or
calculated averages of hexavalent chromium for the PRRI monitoring site exceeded any of the
MRL risk values.
22-12
-------
Table 22-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Rhode
Island Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Providence, Rhode Island - PRRI
Hexavalent Chromium
37
0.11
0.12
0.14
0.12
0.11
0.13
-0.17
to
to
-------
22.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutant that failed at least one screen at the Rhode Island monitoring site and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 22-7. The
data from NATA are presented for the census tract where the monitoring site is located. The
census tract ID for PRRI is 44007000400, for which the population was 3,660 and represented
0.5 percent of the 2000 county population. The pollutant of interest for the PRRI monitoring site
is bolded.
Observations for PRRI from Table 22-7 include the following:
• The modeled concentration for hexavalent chromium from NATA was less than 0.01
|ig/m3, as is the annual average.
• The cancer risk from hexavalent chromium according to NATA (1.40 in-a-million)
was an order of magnitude higher than the cancer surrogate risk approximation (0.18
in-a-million).
• The noncancer risk according to NATA and the noncancer risk approximation for
hexavalent chromium were both less than 0.01.
22.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 22-8 and 22-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 22-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer surrogate risk approximations (in-a-million), as calculated from the annual averages.
Table 22-9 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
22-14
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Table 22-7. Cancer and Noncancer Risk Summary for the Monitoring Site in Rhode Island
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Providence, Rhode Island (PRRI) - Census Tract ID 44007000400
Hexavalent Chromium
0.012
0.0001
0.01
1.40
0.01
O.01
±0.01
0.18
0.01
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
to
to
-------
Table 22-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Rhode Island
to
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Providence, Rhode Island (PRRI) - Providence County
Benzene
Formaldehyde
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
Trichloroethylene
Dichloromethane
/>-Dichlorobenzene
Naphthalene
Nickel, PM
314.40
176.20
93.12
51.63
42.14
41.72
30.22
13.64
8.07
4.58
Benzene
Hexavalent Chromium
1,3 -Butadiene
Nickel, PM
Tetrachloroethylene
Cadmium, PM
Naphthalene
Arsenic, PM
£>-Dichlorobenzene
Acetaldehyde
2.45E-03
1.98E-03
1.26E-03
7.32E-04
5.49E-04
2.91E-04
2.74E-04
1.76E-04
1.50E-04
1.14E-04
Hexavalent Chromium 0.18
-------
to
to
Table 22-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Rhode Island
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximation
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Providence, Rhode Island (PRRI) - Providence County
Toluene
Methyl tert-butyl ether
Xylenes
Methanol
Benzene
Formaldehyde
Ethylbenzene
Hexane
Tetrachloroethylene
Acetaldehyde
829.38
635.64
567.30
328.61
314.40
176.20
129.33
112.71
93.12
51.63
Acrolein
Nickel, PM
1,3 -Butadiene
Formaldehyde
Benzene
Cadmium, PM
Cyanide Compounds, gas
Acetaldehyde
Xylenes
Chlorine
415,493.94
70,408.65
21,071.44
17,979.35
10,479.85
8,096.02
7,867.00
5,736.72
5,672.97
4,567.50
Hexavalent Chromium <0.01
-------
respectively. As a result, although the actual value of the emissions will be the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on the site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 22.3, PRRI sampled for
hexavalent chromium only. In addition, the cancer and noncancer surrogate risk approximations
are limited to those sites sampling for a long enough period for annual averages to be calculated.
Observations from Table 22-8 include the following:
• Benzene, formaldehyde, and tetrachloroethylene were the highest emitted pollutants
with cancer UREs in Providence County.
• Benzene was also the pollutant with the highest toxi city-weighted emissions (of the
pollutants with cancer UREs), followed by hexavalent chromium and 1,3-butadiene.
• Seven of the highest emitted pollutants also had the highest toxi city-weighted
emissions for Providence County.
• Hexavalent chromium, which was the only pollutant sampled at PRRI, had the second
highest toxicity-weighted emissions for Providence County. This pollutant did not
appear on the list of highest emitted pollutants.
Observations from Table 22-9 include the following:
• Toluene, methyl fert-butyl ether, and xylenes were the highest emitted pollutants with
noncancer RfCs in Providence County.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, nickel, and 1,3-butadiene.
• Four of the highest emitted pollutants in Providence County also had the highest
toxicity-weighted emissions.
• Hexavalent chromium did not appear on the list of highest emitted pollutants or the
list of highest toxicity-weighted emissions for pollutants with noncancer toxi city
factors.
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22.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Hexavalent chromium failed two screens for PRRI.
»«» Hexavalent chromium did not exceed any of the MRL health benchmarks.
22-19
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23.0 Site in South Carolina
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in South Carolina, and integrates these
concentrations with emissions, meteorological, and risk information.
23.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The South Carolina site is
located in Chesterfield County. Figure 23-1 is a composite satellite image retrieved from
Google™ Maps showing the monitoring site in its rural location. Figure 23-2 identifies point
source emission locations within 10 miles of the site as reported in the 2002 NEI for point
sources. Table 23-1 describes the area surrounding the monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
CHSC is located in central Chesterfield County, about 10 miles south of the North and
South Carolina border, between the towns of McBee and Chesterfield. The monitoring site is
located near the Ruby fire tower and, as Figure 23-1 shows, is located just off Highway 145.
The surrounding area is rural in nature and is part of the Carolina Sandhills Wildlife Refuge.
Figure 23-2 shows that few point sources are located within 10 miles of CHSC.
Table 23-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the South
Carolina monitoring site. County-level vehicle registration and population data for Chesterfield
County were obtained from the South Carolina Department of Motor Vehicles and the U.S.
Census Bureau. Table 23-2 also includes a vehicle registration to county population ratio
(vehicles per person). In addition, the population within 10 miles of the site is presented. An
estimate of 10-mile vehicle registration was calculated by applying the county-level vehicle
registration to population ratio to the 10-mile population surrounding the monitoring site.
23-1
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Figure 23-1. Chesterfield, South Carolina (CHSC) Monitoring Site
to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 23-2. NEI Point Sources Located Within 10 Miles of CHSC
.
•
Si'rtTl'W
Hot* Out tattail) dwiwlj *nd
ifi5pl»ye-d may not
Ihnctil tuait**
aiva ol merest
Legend
T^T CHSC NATTS site
10 mile radius
J County bowidary
Source Category Group (No. of Facilities)
F Fuel Combustion Industrial Facility (1)
S Surface Coaling Processes Industrial Facility (1)
23-3
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Table 23-1. Geographical Information for the South Carolina Monitoring Site
Site
Code
CHSC
AQS Code
45-025-0001
Location
Not in a
city
County
Chesterfield
Micro- or
Metropolitan
Statistical Area
Not in an MSA
Latitude
and
Longitude
34.617119,
-80.198789
Land Use
Forest
Location
Setting
Rural
Description of the
Immediate Surroundings
The site was chosen as a background site. It is very
rural and in the middle of Carolina Sandhills Wildlife
Refuge. The site is located on secondary road SC 145
between McBee and Chesterfield. Traffic on 145 is
light. The nearest industry (AO Smith Water
Heaters) is approximately 9 miles away. Elevation is
-450'.
BOLD = EPA-designated NATTS Site
to
-k
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Table 23-2. Population, Motor Vehicle, and Traffic Information for the South Carolina
Monitoring Site
Site
CHSC
2007
Estimated
County
Population
42,761
Number
of
Vehicles
Registered
42,726
Vehicles
per Person
(Registration:
Population)
1.00
Population
Within
10 Miles
36,555
Estimated
10-mile
Vehicle
Ownership
36,525
Annual
Average
Traffic
Data1
650
VMT
(thousands)
NA
1 Daily Average Traffic Data reflects 2006 data from the South Carolina DOT
BOLD = EPA-designated NATTS Site
Table 23-2 also contains annual average daily traffic information, as well as the year of the
traffic data estimate and the source from which it was obtained. Finally, Table 23-2 presents the
daily VMT for each urban area (where applicable).
Observations from Table 23-2 include the following:
• Chesterfield County's population was rather low compared to all counties with
NATTS or UATMP sites. This is also true of its 10-mile population.
• Both the county-level and 10-mile radius vehicle registration were low compared to
all counties with NATTS or UATMP sites.
• The vehicle per person ratio was one vehicle per person. While this may seem high,
it ranked 16* among all NATTS and UATMP sites.
• The traffic volume experienced near CHSC ranked second lowest compared to other
monitoring sites. The traffic estimate used came from State Road 145 between State
Roadl09&US-l.
• VMT was unavailable for this area.
23.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in South Carolina on sampling days, as well as over the course of the year.
23.2.1 Climate Summary
The town of Chesterfield is located on the NC/SC border, north of Florence. The area
boasts a temperate climate, typical of its southeast location. Winters tend to be mild and
23-5
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snowfall is rare, while summers are typically hot and humid, due in part to its proximity to the
Atlantic Ocean (SC SCO, 2008).
23.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Monroe Airport, Monroe, North Carolina (WBAN 53872).
Table 23-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 23-3 is the 95 percent
confidence interval for each parameter. As shown in Table 23-3, average meteorological
conditions on sampling days were representative of average weather conditions throughout the
year.
23.2.3 Composite Back Trajectories for Sampling Days
Figure 23-3 is the composite back trajectory map for the South Carolina monitoring site
for the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the site in Figure 23-3 represents 100 miles.
Observations from Figure 23-3 include the following:
• Back trajectories originated from a variety of directions at CHSC.
• The 24-hour air shed domain for CHSC was similar in size to other monitoring sites.
The furthest away a trajectory originated was central Illinois, or nearly 600 miles
away. However, most trajectories originated within 400 miles of the site.
23-6
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Table 23-3. Average Meteorological Conditions near the South Carolina Monitoring Site
Site
CHSC
Closest NWS
Station and
WBAN
Monroe
Airport,
Monroe, NC
53872
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
74.82
±4.00
73.76
±1.63
Average
Temperature
(op)
63.02
±3.73
62.57
±1.54
Average
Dew Point
Temperature
(°F)
46.40
±4.10
46.32
±1.72
Average
Wet Bulb
Temperature
(»F)
54.32
±3.34
54.14
±1.40
Average
Relative
Humidity
(%)
59.23
±3.45
59.56
± 1.40
Average
Sea Level
Pressure
(mb)
1019.36
±1.44
1019.08
±0.60
Average
Scalar Wind
Speed
(kt)
4.68
±0.59
4.97
±0.27
BOLD = EPA-designated NATTS Site
to
oo
-------
Figure 23-3. Composite Back Trajectory Map for CHSC
to
OJ
oo
-------
23.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at Monroe Airport near CHSC were uploaded
into a wind rose software program, WRPLOT (Lakes, 2006) to produce customized wind roses.
A wind rose shows the frequency of wind directions on a 16-point compass, and uses different
shading to represent wind speeds. Figure 23-4 is the wind rose for the CHSC monitoring site on
days that samples were collected.
Observations from Figure 23-4 for CHSC include the following:
• Calm winds were prevalent near CHSC, as calm winds were observed for over one-
third of the hourly measurements.
• For winds greater than 2 knots, southwesterly winds were observed most frequently.
• Winds exceeding 11 knots made up only 7 percent of observations.
Figure 23-4. Wind Rose for CHSC Sampling Days
23-9
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23.3 Pollutants of Interest
"Pollutants of interest" were determined for the site in order to allow analysts and readers
to focus on a risk-based subset of pollutants. The pollutants of interest for the South Carolina
monitoring site were identified using the EPA risk screening process described in Section 3.2.
Each pollutant's measured concentration was compared to its associated risk screening value. If
the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 23-4 presents the pollutants that failed at least one screen for the South Carolina
monitoring site and highlights the site's pollutants of interest (shaded). CHSC sampled
hexavalent chromium only.
Table 23-4. Comparison of Measured Concentrations and EPA Screening Values for the
South Carolina Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Chesterfield, South Carolina - CHSC
Hexavalent Chromium
Total
0
0
17
17
0.00
0.00
0.00
0.00
Observations from Table 23-4 include the following:
• Hexavalent chromium was detected in 17 samples and did not fail any screens.
• In order to facilitate analysis, hexavalent chromium is considered CHSC's pollutant
of interest.
23.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the South Carolina monitoring site. The averages presented are provided for the pollutants of
interest for each monitoring site. Complete site-specific statistical summaries are provided in
Appendices J through O. In addition, concentration averages for select pollutants are presented
from previous sampling years in order to characterize concentration trends at the site, where
applicable.
23-10
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23.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 23-5. The averages
presented in Table 23-5 are shown in ng/m3 for ease of viewing.
Table 23-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the South Carolina Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average1
(ng/m3)
Chesterfield, South Carolina - CHSC
Hexavalent Chromium
17
58
0.007
±0.001
NR
NR
0.005
±0.001
NR
0.005
±0.001
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for CHSC from Table 23-5 include the following:
• The daily average concentration of hexavalent chromium was slightly higher than the
annual average (0.007 ± 0.001 ng/m3 vs. 0.005 ± 0.001 ng/m3), which illustrates the
effect of the substitution of 1/2 MDL.
• Only one seasonal average (summer) of hexavalent chromium could be calculated
due to the overall low number of detections.
23.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one ore more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
23-11
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described in Section 3.6.4. CHSC has not sampled continuously for five years as part of the
National Monitoring Programs; therefore, the trends analysis was not conducted.
23.5 Pearson Correlations
Table 23-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of hexavalent chromium and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for CHSC from Table 23-6 include the following:
• All of the correlations for CHSC were relatively weak.
23.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
23.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the South
Carolina monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available.
As described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of hexavalent chromium were compared to the
acute MRL; the seasonal averages were compared to the intermediate MRL; and the annual
averages were compared to the chronic MRL. None of the measured concentrations or
calculated averages of hexavalent chromium exceeded any of the MRL risk values for CHSC.
23.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants of interest for the South Carolina monitoring site and where the annual
average concentrations could be calculated, risk was further examined by reviewing cancer and
noncancer risk estimates from NATA and calculating cancer and noncancer surrogate risk
approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
23-12
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Table 23-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the South
Carolina Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Chesterfield, South Carolina - CHSC
Hexavalent Chromium
17
0.12
0.12
0.25
0.20
0.42
-0.10
0.18
to
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cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
noncancer surrogate risk approximations are presented in Table 23-7. The data from NATA are
presented for the census tract where the monitoring site is located. The census tract ID for
CHSC is 45025950800, for which the population was 2,492, and represented 5 percent of the
2000 county population. The pollutants of interest for the monitoring site are bolded.
Observations for CHSC from Table 23-7 include the following:
• The modeled concentration for hexavalent chromium from NATA was less than 0.01
|ig/m3, as was the annual average.
• The cancer risk from hexavalent chromium according to NATA (0.22 in-a-million)
was an order of magnitude higher than the cancer risk approximation (0.05 in-a-
million), although both were fairly low.
• The noncancer risk according to NATA and the noncancer risk approximation for
hexavalent chromium were both less than 0.01.
23.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 23-8 and 23-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 23-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer surrogate risk approximations (in-a-million), as calculated from the annual averages.
Table 23-9 presents similar information, but identifies the 10 pollutants with the highest
noncancer surrogate risk approximations (HQ), as calculated from the annual averages. The
pollutants in these tables are limited to those that have cancer and noncancer risk factors,
respectively. As a result, although the actual value of the emissions are the same, the highest
emitted pollutants in the cancer table may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
risk surrogate approximations based on the site's annual averages are limited to those pollutants
for which the site sampled. As discussed in Section 23.3, CHSC sampled for hexavalent.
23-14
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Table 23-7. Cancer and Noncancer Risk Summary for the Monitoring Site in South Carolina
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Chesterfield, South Carolina (CHSC) - Census Tract ID 45025950800
Hexavalent Chromium
0.012
0.0001
0.01
0.22
0.01
0.01
±0.01
0.05
0.01
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
to
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Table 23-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in South Carolina
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximations
Pollutant (in-a-million)
Chesterfield, South Carolina (CHSC) - Chesterfield County
Benzene
Formaldehyde
Dichloromethane
Acetaldehyde
1,3 -Butadiene
Trichloroethylene
Naphthalene
Tetrachloroethylene
POM, Group 2
/>-Dichlorobenzene
56.07
14.57
7.23
5.21
4.45
2.86
1.82
1.66
0.97
0.92
Benzene
1,3 -Butadiene
Naphthalene
POM, Group 2
POM, Group 3
Hexavalent Chromium
POM, Group 5
Arsenic, PM
Nickel, PM
Acetaldehyde
4.37E-04
1.33E-04
6.18E-05
5.34E-05
2.90E-05
2.63E-05
2.12E-05
1.99E-05
1.23E-05
1.15E-05
Hexavalent Chromium 0.05
-------
to
Table 23-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in South Carolina
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Chesterfield, South Carolina (CHSC) - Chesterfield County
Toluene
Xylenes
Benzene
Methanol
Ethylene glycol
Ethylbenzene
Hexane
Methyl isobutyl ketone
Glycol ethers, gas
Formaldehyde
152.24
131.39
56.07
33.91
31.98
27.55
21.50
19.98
18.08
14.57
Acrolein
1,3 -Butadiene
Benzene
Formaldehyde
Cyanide Compounds, gas
Xylenes
Nickel, PM
Glycol ethers, gas
Naphthalene
Acetaldehyde
40,795.44
2,224.64
1,868.85
1,487.10
1,388.57
1,313.89
1,180.28
903.80
605.84
578.49
Hexavalent Chromium <0.01
-------
chromium only. In addition, the cancer and noncancer surrogate risk approximations are limited
to those sites sampling for a long enough period for annual averages to be calculated
Observations from Table 23-8 include the following:
• Benzene, formaldehyde, and dichloromethane were the highest emitted pollutants
with cancer UREs in Chesterfield County.
• Benzene was also the pollutant with the highest toxi city-weighted emissions (of the
pollutants with cancer UREs), followed by 1,3-butadiene and naphthalene.
• Five of the highest emitted pollutants also had the highest toxi city-weighted
emissions for Chesterfield County.
• Hexavalent chromium, which was the only pollutant sampled at CHSC, had the sixth
highest toxicity-weighted emissions for Chesterfield County. This pollutant did not
appear on the list of highest emitted pollutants.
Observations from Table 23-9 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Chesterfield County.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, 1,3-butadiene, and benzene.
• Four of the highest emitted pollutants in Chesterfield County also had the highest
toxicity-weighted emissions.
• Hexavalent chromium did not appear on the list of highest emitted pollutants on the
list of highest toxicity-weighted emissions for pollutants with a noncancer toxi city
factors. Its noncancer risk approximation was very low.
23.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Hexavalent chromium did not fail any screens for CHSC; it was, however, considered
a pollutant of interest in order to allow data analyses to be conducted.
»«» Hexavalent chromium did not exceed any of the MRL health benchmarks.
23-18
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24.0 Sites in South Dakota
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the UATMP sites in South Dakota, and integrates these
concentrations with emissions, meteorological, and risk information.
24.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. CUSD is located in the
town of Custer. The SFSD monitoring site is located in the Sioux Falls, SD MSA. Figures 24-1
and 24-2 are composite satellite images retrieved from Google™ Maps showing the monitoring
sites in their rural and urban locations. Figures 24-3 and 24-4 identify point source emission
locations within 10 miles of each site as reported in the 2002 NEI for point sources. Table 24-1
describes the area surrounding each monitoring site and provides supplemental geographical
information such as land use, location setting, and locational coordinates.
CUSD is located in the town of Custer on the west side of the state, south of Rapid City.
The town is located in the Black Hills and lies west of Custer State Park. The monitoring site is
located just south of the Highway 89 and Highway 16 intersection, on the property of a sports
complex on the outskirts of town. A residential subdivision is located just south and west of the
site, as shown in Figure 24-1. Mobile sources and burning (wildfires and residential heating) are
the primary emission sources in the area. As Figure 24-3 shows, no point source emission
sources are located within 10 miles of the CUSD monitoring site.
SFSD is located on the east side of Sioux Falls, in eastern South Dakota. The monitoring
site is located between two elementary schools in the center of a large residential area, as shown
in Figure 24-2. The Hilltop water tower is just south of the site. The location of the monitoring
site was selected to capture emissions from upwind sources west and northwest of the monitoring
site. SFSD is approximately one half-mile from the intersection of Highway 42 and 1-229. As
Figure 24-4 shows, the few emission sources within 10 miles of SFSD are primarily located to
24-1
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Figure 24-1. Custer, South Dakota (CUSD) Monitoring Site
to
-^
to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 24-2. Sioux Falls, South Dakota (SFSD) Monitoring Site
to
OJ
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 24-3. NEI Point Sources Located Within 10 Miles of CUSD
•
Now Dwlo tadlly domity and coOocation lh» tt*al f»alli«
Legend
•^- CUSD UATMP site
10 mile radius
_] County boundary
*There were no facilities in the 2002 NEI within 10 miles of CUSD.
24-4
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Figure 24-4. NEI Point Sources Located Within 10 Miles of SFSD
Note: Due to facility density and collocation, the total facilities
displayed may not represent all facilities within the area of interest.
Legend
••&• SFSD UATMP site
Q 10 mile radius
J Count/ boundary
Source Category Group (No. of Facilities)
* Automotive Repair, Services, & Parking (1)
c Chemicals & Allied Products Facility (1)
F Fuel Combustion Industrial Facility (1)
J Industrial Machinery & Equipment Facility (3)
s Surface Coating Processes Industrial Facility (1)
24-5
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Table 24-1. Geographical Information for the South Dakota Monitoring Sites
Site
Code
CUSD
SFSD
AQS Code
46-033-0003
46-099-0007
Location
Custer
Sioux Falls
County
Custer
Minnehaha
Micro- or
Metropolitan
Statistical
Area
Not in an MSA
Sioux Falls, SD
Latitude and
Longitude
43.766798,
-103.584695
43.537626,
-96.682001
Land Use
Residential
Residential
Location
Setting
Suburban
Urban/City
Center
Description of the
Immediate Surroundings
The site is located on the edge of an urban area, in a
pasture across the road from the last housing
development on the east side of the City of Custer.
The city has a population of 1,860 and is the largest
city in the county. The city is located in a river
valley in the Black Hills with pine covered hills on
the north and south sides of the valley. The site is
located in the center of the valley on the east side of
the city. Major sources near the site include
vehicles (highest traffic counts from May through
September), forest fires (mainly during July through
September), wood burning for heat, and wildland
heath fires (during the winter months). The main
industries in the area include tourism, logging, and
mining of feldspar/quartz.
The SFSD monitoring site is located in Sioux Falls,
SD, the largest city in the state. Two grade schools
are north of the site and residential areas are to the
west, east, and south. The area within 1 mile of the
site is mostly residential with a few retail
businesses. The main industrial area of the city is
about 3 miles northwest and 2 miles to the west of
the site. The site was selected because it represents
population exposure to chemical and paniculate
emissions from the industrial parts of the city. The
predominant wind direction is northwest for most of
the year with southeast winds during the summer
months.
to
-------
the northwest of the site. The industrial machinery and equipment source category is the most
numerous category of point sources within 10 miles of SFSD.
Table 24-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the South
Dakota monitoring sites. County-level vehicle registration and population data for Custer and
Minnehaha Counties were obtained from the South Dakota Motor Vehicle Division and the U.S.
Census Bureau. Table 24-2 also includes a vehicle registration to county population ratio
(vehicles per person). In addition, the population within 10 miles of each site is presented. An
estimate of 10-mile vehicle registration was calculated by applying the county-level vehicle
registration to population ratio to the 10-mile population surrounding the monitoring sites. Table
24-2 also contains annual average daily traffic information, as well as the year of the traffic data
estimate and the source from which it was obtained. Finally, Table 24-2 presents the daily VMT
for each urban area (where applicable).
Table 24-2. Population, Motor Vehicle, and Traffic Information for the South Dakota
Monitoring Sites
Site
CUSD
SFSD
2007
Estimated
County
Population
7,818
175,272
Number
of
Vehicles
Registered
15,345
212,906
Vehicles
per Person
(Registration:
Population)
1.96
1.21
Population
Within
10 Miles
5,549
167,117
Estimated
10-mile
Vehicle
Ownership
10,891
203,000
Annual
Average
Traffic
Data1
2,500
4,265
VMT
(thousands)
NA
2,344
1 Daily Average Traffic Data reflects 2006 data from the South Dakota DOT (CUSD) and 2005 data from the South
Dakota DOT (SFSD)
Observations from Table 24-2 include the following:
• Both county-level populations were on the low side compared to counties with
NATTS or UATMP sites. Custer County's population was the lowest of all sites,
while Minnehaha County was 13th lowest. CUSD's 10-mile population was second
lowest (behind CAMS 85), while SFSD's 10-mile population was 14th lowest.
• Both county-level vehicle registrations were on the low side compared to counties
with NATTS or UATMP sites. Custer County's registration was the second lowest of
all sites, while Minnehaha County was 16th lowest. CUSD's 10-mile vehicle
ownership estimate was second lowest (behind CAMS 85), while SFSD's 10-mile
vehicle ownership estimate was 17th lowest.
24-7
-------
• The vehicle-per-person ratios for these sites were fairly high, indicating that each
person likely owns multiple vehicles. The ratio for CUSD is the highest among all
sites, while SFSD's ratio is the fifth highest.
• The traffic volumes for the South Dakota sites ranked 5th and 7th lowest compared to
other program sites. Traffic for CUSD was obtained near the intersection of Highway
16 and 89; traffic for SFSD was obtained from Bahnson Avenue near Cleveland
School.
• The Sioux Falls area VMT was the third lowest among urban areas with UATMP or
NATTS sites. VMT was not available for Custer.
24.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in South Dakota on sampling days, as well as over the course of the year.
24.2.1 Climate Summary
The Sioux Falls area has a continental climate, with cold winters, warm summers, and
often drastic day to day variations. Precipitation varies throughout the year, but is typically
sufficient for the springtime growing season. On average, a south wind blows in the summer and
a northwesterly wind blows in the winter. The weather in Custer is considered semi-arid
continental; annual precipitation is light. Warm summers and relatively mild winters are
characteristic of this area, due to the Black Hills to the west, which allow winters to be milder in
comparison to the rest of the state (Ruffner and Bair, 1987).
24.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at Custer County Airport (near CUSD) and Joe Foss Field
Airport (near SFSD), WBAN 94032 and 14944, respectively.
24-8
-------
Table 24-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 24-3 is the 95 percent
confidence interval for each parameter. As shown in Table 24-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
24.2.3 Composite Back Trajectories for Sampling Days
Figures 24-5 and 24-6 are composite back trajectory maps for the South Dakota
monitoring sites for the days on which samples were collected. Each line represents the 24-hour
trajectory along which a parcel of air traveled toward the monitoring site on a sampling day.
Each concentric circle around the sites in Figures 24-5 and 24-6 represents 100 miles.
Observations from Figure 24-5 for CUSD include the following:
• Back trajectories originated from a variety of directions at the CUSD monitoring site,
although most trajectories originated from the west or northwest.
• The 24-hour air shed domain for CUSD was somewhat larger in size than other
monitoring sites. The furthest away a trajectory originated was British Columbia,
Canada, or 800 miles away. However, 75 percent of the trajectories originated within
400 miles.
Observations from Figure 24-6 for SFSD include the following:
• Back trajectories originated from a variety of directions at the SFSD site, although
primarily from the northwest and southwest.
• The 24-hour air shed domain for SFSD was the largest of all the monitoring sites.
The furthest away a trajectory originated was Alberta, Canada, or nearly 1,100 miles
away. However, 95 percent of the trajectories originated within 700 miles of the site.
24-9
-------
Table 24-3. Average Meteorological Conditions near the South Dakota Monitoring Sites
Site
CUSD
SFSD
Closest NWS
Station and
WBAN
Custer County
Airport
94032
Joe Foss Field
Airport
14944
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
53.77
±5.80
54.38
±2.18
55.82
±6.41
57.28
±2.54
Average
Temperature
(op)
44.17
±5.20
44.06
± 1.99
47.52
±5.82
47.90
±2.40
Average
Dew Point
Temperature
(°F)
27.07
±3.96
27.64
±1.68
36.72
±5.36
37.28
±2.25
Average
Wet Bulb
Temperature
(»F)
36.18
±4.05
36.35
±1.63
42.26
±5.21
42.71
±2.17
Average
Relative
Humidity
(%)
57.11
±4.32
57.52
± 1.59
68.96
±3.02
69.35
±1.14
Average
Sea Level
Pressure
(mb)
1015.79
±1.95
1014.60
±0.72
1017.28
± 1.97
1016.22
±0.79
Average
Scalar Wind
Speed
(kt)
5.74
±0.53
5.73
±0.22
8.70
±1.03
8.45
±0.39
to
o
-------
Figure 24-5. Composite Back Trajectory Map for CUSD
0 25 50 100 150 200
mat
-------
Figure 24-6. Composite Back Trajectory Map for SFSD
to
-------
24.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations at Custer County (for CUSD) and Joe Foss
Field Airports (for SFSD) were uploaded into a wind rose software program, WRPLOT (Lakes,
2006) to produce customized wind roses. A wind rose shows the frequency of wind directions
on a 16-point compass, and uses different shading to represent wind speeds. Figures 24-7 and
24-8 are the wind roses for the South Dakota monitoring sites on days that samples were
collected.
Observations from Figure 24-7 for CUSD include the following:
• Westerly winds prevailed near CUSD. Northwesterly and southwesterly winds were
also observed frequently.
• Calm winds were observed for nearly 16 percent of the observations.
• Winds exceeding 11 knots made up 10 percent of observations. The strongest winds
most often had a westerly component.
Figure 24-7. Wind Rose for CUSD Sampling Days
NORTH"---.
WEST
SOUTH .--
WIND SPEED
(Knots)
EH >=22
• 17 - 21
• 11 - 17
EH 1-7
• 2- 4
Calms: 15.72%
24-13
-------
Figure 24-8. Wind Rose for SFSD Sampling Days
NORTH"---.
15%
•WEST
•SOUTH ,-
| 2- 4
Calms: 11.00%
Observations from Figure 24-8 for SFSD include the following:
• Southerly winds prevailed near SFSD. Northwesterly winds were also observed
frequently.
• Calm winds were observed for 11 percent of the observations.
• Winds exceeding 11 knots made up 31 percent of observations, the largest percentage
among all UATMP and NATTS sites. Wind speeds greater than 22 knots were
frequently observed with northwesterly, southeasterly, and southerly winds.
24.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the South
Dakota monitoring sites were identified using the EPA risk screening process described in
Section 3.2. In brief, each pollutant's measured concentration was compared to its associated
risk screening value. If the daily concentration was greater than the risk screening value, then
the measured concentration "failed the screen." Pollutants of interest are those for which the
24-14
-------
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 24-4 presents the pollutants that failed at least one screen for each South Dakota
monitoring site and highlights each site's pollutants of interest (shaded). CUSD and SFSD
sampled for VOC, SNMOC, and carbonyl compounds.
Table 24-4. Comparison of Measured Concentrations and EPA Screening Values for
South Dakota Monitoring Sites
the
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Custer, South Dakota - CUSD
Acrolein
Benzene
Carbon Tetrachloride
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Acrylonitrile
Tetrachloroethylene
Trichloroethylene
£>-Dichlorobenzene
Dichloromethane
1 , 1 ,2,2-Tetrachloroethane
w-Hexane
1 ,2-Dichloroethane
Total
60
60
60
58
57
35
20
3
2
2
1
1
1
1
361
60
60
60
60
60
56
20
32
4
13
60
1
60
1
547
100.00
100.00
100.00
96.67
95.00
62.50
100.00
9.38
50.00
15.38
1.67
100.00
1.67
100.00
66.00
16.62
16.62
16.62
16.07
15.79
9.70
5.54
0.83
0.55
0.55
0.28
0.28
0.28
0.28
16.62
33.24
49.86
65.93
81.72
91.41
96.95
97.78
98.34
98.89
99.17
99.45
99.72
100.00
Sioux Falls, South Dakota - SFSD
Carbon Tetrachloride
Acetaldehyde
Acrolein
Benzene
Formaldehyde
1,3 -Butadiene
Acrylonitrile
1 ,2-Dichloroethane
Tetrachloroethylene
Total
59
59
58
58
56
18
3
2
1
314
59
59
58
59
59
51
3
2
48
398
100.00
100.00
100.00
98.31
94.92
35.29
100.00
100.00
2.08
78.89
18.79
18.79
18.47
18.47
17.83
5.73
0.96
0.64
0.32
18.79
37.58
56.05
74.52
92.36
98.09
99.04
99.68
100.00
24-15
-------
Observations from Table 24-4 include the following:
• Fourteen pollutants with a total of 361 measured concentrations failed at least one
screen for CUSD. Nine pollutants with a total of 314 measured concentrations failed
screens for SFSD.
• The following six pollutants of interest were common to both sites: acetaldehyde,
acrolein, benzene, 1,3-butadiene, carbon tetrachloride, and formaldehyde.
• Of the six common pollutants of interest, 100 percent of the measured detections of
acrolein and carbon tetrachloride failed screens for both sites.
• Of the pollutants with at least one failed screen, nearly 79 percent of measurements
failed screens for SFSD, while 66 percent failed screens for CUSD. While the failure
rate appears higher for SFSD, several frequently detected pollutants only failed one
screen at CUSD, increasing the number of measured detections but contributing few
to the total number of failed screens.
24.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the South Dakota monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the sites, where applicable.
24.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and when the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages for the South Dakota monitoring sites are
presented in Table 24-5, where applicable.
24-16
-------
Table 24-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the South Dakota Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(jig/m3)
Annual
Average1
(jig/m3)
Custer, South Dakota - CUSD
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
60
60
20
60
56
60
60
60
60
60
60
60
60
60
1.91
±0.32
0.59
±0.10
0.28
±0.05
0.66
±0.13
0.07
±0.02
0.55
±0.04
2.03
±0.31
1.58
±0.36
0.49
±0.16
NR
0.81
±0.29
0.09
±0.04
0.46
±0.09
1.41
±0.39
1.32
±0.21
0.42
±0.09
0.14
±0.08
0.48
±0.13
0.05
±0.02
0.61
±0.07
1.35
±0.13
3.04
±0.93
0.72
±0.19
0.20
±0.08
0.58
±0.16
0.04
±0.01
0.58
±0.07
3.15
±0.79
1.73
±0.43
0.71
±0.30
NR
0.81
±0.37
0.09
±0.04
0.55
±0.06
2.20
±0.43
1.91
±0.32
0.59
±0.10
0.11
±0.03
0.66
±0.13
0.07
±0.02
0.55
±0.04
2.03
±0.31
Sioux Falls, South Dakota - SFSD
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
59
58
59
51
59
59
59
59
59
59
59
59
1.55
±0.23
0.56
±0.09
0.56
±0.07
0.04
±0.01
0.57
±0.04
3.57
±2.52
2.09
±0.57
0.34
±0.09
0.66
±0.13
0.05
±0.02
0.47
±0.08
7.19
± 10.38
1.02
±0.15
0.55
±0.15
0.51
±0.06
0.04
±0.01
0.63
±0.07
2.28
±0.34
1.55
±0.33
0.79
±0.21
0.61
±0.22
0.04
±0.01
0.57
±0.08
3.09
±0.39
1.63
±0.51
0.53
±0.14
0.44
±0.07
0.03
±0.01
0.59
±0.05
2.01
±0.33
1.55
±0.23
0.55
±0.09
0.55
±0.07
0.04
±0.01
0.57
±0.04
3.57
±2.52
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for CUSD from Table 24-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (2.03 ± 0.31 |ig/m3), acetaldehyde (1.91 ± 0.32 |ig/m3), and benzene
(0.66 ±0.13 |ig/m3).
• As shown in Table 4-11, of the program-level pollutants of interest, CUSD had the
sixth highest daily average concentration of acrylonitrile. None of the remaining
daily average concentrations of the pollutants of interest for CUSD appeared in
Tables 4-9 and 4-11.
24-17
-------
• Concentrations of acetaldehyde and formaldehyde were highest during the summer.
The concentrations of the other pollutants of interest did not vary significantly from
season to season.
Observations for SFSD from Table 24-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (3.57 ± 2.52 |ig/m3), acetaldehyde (1.55 ± 0.23 |ig/m3), and carbon
tetrachloride (0.57 ± 0.04 |ig/m3).
• As shown in Table 4-11, of the program-level pollutants of interest, CUSD had the
seventh (behind CUSD) highest daily average concentration of acrylonitrile. None of
the remaining daily average concentrations of the pollutants of interest for SFSD
appeared in Tables 4-9 and 4-11.
• The confidence interval for the daily average concentration of formaldehyde was
rather large, indicating the influence of outliers. The winter average concentration of
formaldehyde was much higher than other seasons with a very large confidence
interval, indicating that the outliers were measured during this season.
• The concentrations of the other pollutants of interest did not vary significantly from
season to season.
24.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. CUSD has sampled VOC, SNMOC, and carbonyls since 2002.
SFSD has sampled VOC since 2000, SNMOC since 2001, and carbonyls since 2002.
Figures 24-9 through 24-16 present the three-year rolling statistical metrics graphically for
benzene (both methods), 1,3-butadiene, and formaldehyde for each monitoring site. The
statistical metrics presented for calculating trends include the substitution of zeros for non-
detects.
Observations from Figures 24-9 and 24-10 for benzene measurements at CUSD include
the following:
• Although the magnitude of the concentrations in Figures 24-9 and 24-10 are different,
the plots are very similar, reflecting the ability of the methods to report similar
tendencies.
24-18
-------
Figure 24-9. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at CUSD (SNMOC)
to
VO
25.00 i
20.00
15.00
o.
a
=
o
=
01
tj
o 10.00
5.00
0.00
2002-2004
2003-2005 2004-2006
Three-Year Period
2005-2007
1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 24-10. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at CUSD (TO-15)
to
to
o
6.00 i
5.00
4.00
o.
&
o
'•I 3.00
=
01
tj
a
o
U
2.00 -
1.00 -
0.00
2002-2004 2003-2005 2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 24-11. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at CUSD
1.60
1.40
1.20
1.00
o.
o.
=
1 0.80
=
01
to
-^
to
0.60
0.40
0.20
2002-2004 2003-2005 2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 24-12. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at CUSD
to
to
to
50.00 i
45.00
40.00
5.00
.£ 30.00
o.
=
o
•
=
01
CJ
o 20.00
15.00
10.00
2002-2004 2003-2005 2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum • Median — Maximum O Average • 3rd Quartile
-------
Figure 24-13. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at SFSD (SNMOC)
to
-^
to
40 on
is on
in on
cr
.Q
o.
o. TS nn
=
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=
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s nn
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•
sss
• •
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•
y
^ 1' g*!lil M^|M Siffiji
2001-2003 2002-2004 2003-2005 2004-2006 2005-2007
Three- Year Period
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 24-14. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at SFSD (TO-15)
to
-^
to
10.00 -i
Q nn
s nn
7 nn
** f, nn
o.
&
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2000-2002 2001-2003 2002-2004 2003-2005 2004-2006 2005-2007
Three- Year Period
• 1st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 24-15. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at SFSD
9 DO
•** 1 SO
o.
o.
=
_o
^
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01
to § i nn
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2000-2002
2001-2003 2002-2004 2003-2005
Three- Year Period
2004-2006
2005-2007
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 24-16. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at SFSD
to
-^
to
70.00 T
60.00
50.00
30.00 -
o
U
20.00 -
10.00 -
0.00
2002-2004 2003-2005 2004-2006
Three-Year Period
2005-2007
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
• In both plots, the maximum concentration was measured between 2004 and 2007,
specifically 2006.
• For each time period shown for both plots, the first quartile, the median, the average,
and the 3rd quartile are very similar in value, reflecting relatively little variability in
the central tendency.
• The rolling average concentrations appeared to have a slight decreasing trend over the
time periods shown, although the difference is not significant, based on the
calculation of confidence intervals.
• All benzene concentrations reported to AQS from the SNMOC method over the six
years of sampling were measured detections. One non-detect was reported for the
TO-15 method.
Observations from Figure 24-11 for 1,3-butadiene measurements at CUSD include the
following:
• The rolling metrics for 1,3-butadiene look different than the rolling metrics for
benzene, primarily due to the impact of the frequency of detection rather than the
magnitude of the measurements.
• The minimum, first and third quartiles, and the median were all zero for the 2002-
2004 time frame; the minimum, first quartile, and median were all zero for the 2003-
2005 and 2004-2006 time frames; and the minimum and first quartile were zero for
the 2005-2007 time frame. In addition, the average concentration was just greater
than the third quartile for each three-year period.
• As the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for this
pollutant increased. The detection rate increased from 11 percent during the 2002-
2004 time frame to 75 percent by the 2005-2007 time frame.
• As the detection rate increased, the average concentration increased as well. This is
more likely an indication of the improvement of the method as opposed to an increase
in overall concentrations. However, because the maximum concentration of 1,3-
butadiene was measured in 2006, further sampling is required to confirm this
conclusion.
• The maximum concentration of 1,3-butadiene was measured on the same day that the
highest concentrations of benzene were measured.
24-27
-------
Observations from Figure 24-12 for formaldehyde measurements at CUSD include the
following:
• The maximum formaldehyde concentration shown was measured in 2004 and was
more than six times the next highest concentration (measured in 2002).
• The difference between the rolling averages and the median values decreased for each
time period. The increasing "closeness" in these metrics indicates decreasing
variability in the central tendency.
• Although difficult to discern, a decrease is shown in the rolling average
concentrations across the periods of sampling.
• All formaldehyde concentrations reported to AQS over the six years of sampling were
measured detections.
Observations from Figures 24-13 and 24-14 for benzene measurements at SFSD include
the following:
• Similar to the benzene plots for CUSD, the benzene plots for both methods for SFSD
are similar, reflecting the ability of the methods to report similar values. This can be
deceiving though, since VOC sampling began a year before SNMOC sampling.
• One difference in the Figures is that the maximum concentration measured by the
TO-15 method was measured in 2003, while the maximum concentration measured
by the SNMOC method was measured in 2002. This difference can be seen by
comparing the two 2003-2005 time frames. However, the day the highest benzene
concentration was measured by the SNMOC method, was the day the second highest
benzene concentration was measured by the TO-15 method.
• For each time period shown in each plot, the first quartile, the median, the average
concentration, and the third quartile were very similar to each other, reflecting
relatively little variability in the central tendency.
• The rolling average concentrations have a decreasing trend since the 2002-2004 time
frame.
• Nearly all benzene concentrations reported to AQS from the TO-15 and SNMOC
methods were measured detections. Two non-detects were reported for each method
since the onset of sampling.
24-28
-------
Observations from Figure 24-15 for 1,3-butadiene measurements at SFSD include the
following:
• The rolling metrics for 1,3-butadiene look different than the rolling metrics for
benzene, primarily due to the impact of the frequency of detection rather than the
magnitude of the measurements.
• Although difficult to discern, the minimum, first and third quartiles, and the median
were all zero for the first four three-year periods; the minimum, first quartile, and
median were all zero for the 2004-2006 time frame; and the minimum and first
quartile were zero for the 2005-2007 time frame. In addition, the average
concentration was greater than the third quartile until the 2004-2006 time frame.
• As the MDL for 1,3-butadiene improved (i.e, decreased), the detection rate for this
pollutant increased. The detection rate increased from 15 percent during the 2000-
2002 and 2001-2003 time frames to 64 percent during the 2005-2007 time frame.
However, the detection rate decreased to five percent during the 2002-2004 time
frame.
• Although difficult to discern in Figure 24-15, the average concentration decreased
across the periods until the 2004-2006 period, where slight increases were observed
for each period.
• The maximum concentration of 1,3-butadiene was measured on the same day in 2002
that the highest and second highest concentrations of benzene, as measured by the
SNMOC and TO-15 methods (respectively) were measured.
Observations from Figure 24-16 for formaldehyde measurements at SFSD include the
following:
• The maximum formaldehyde concentration shown was measured in 2007.
• The rolling average and the median values were similar to each other for each time
period. This "closeness" in these metrics indicates little variability in the central
tendency.
• The rolling average concentrations changed little across the periods, ranging from
2.75 ppbv during the 2003-2005 time frame to 3.03 ppbv during the 2005-2007 time
frame. This is also true of the median concentrations.
• All formaldehyde concentrations reported to AQS over the six years of sampling were
measured detections.
24-29
-------
24.5 Pearson Correlations
Table 24-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for CUSD from Table 24-6 include the following:
• Acrylonitrile exhibited very strong positive correlations with the temperature
parameters, indicating that an increase in temperature results in a proportionate
increase in concentrations of this pollutant. However, this pollutant was detected in
less than half of the sampling collected, which can skew the correlations.
Acrylonitrile also exhibited strong positive correlations with the dew point and wet
bulb temperature and a strong negative correlation with relative humidity.
• 1,3-Butadiene exhibited strong negative correlations with the temperature and
moisture parameters (except relative humidity), indicating that an increase in
temperature and moisture content results in a proportionate decrease in concentration.
• Acetaldehyde exhibited a strong negative correlation with sea level pressure,
indicating that an increase in pressure results in a proportionate decrease in
concentration.
Observations for SFSD from Table 24-6 include the following:
• Most of the correlations for the pollutants of interest for SFSD were weak.
• However, acrolein exhibited strong positive correlations with the temperature and
moisture parameters (except relative humidity), indicating that an increase in
temperature and moisture content results in a proportionate increase in concentration.
24.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
24.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the South
Dakota monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available.
As described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
24-30
-------
Table 24-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the South
Dakota Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Custer, South Dakota - CUSD
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
60
60
20
60
56
60
60
0.33
0.12
0.82
-0.37
-0.50
0.12
0.40
0.37
0.15
0.82
-0.35
-0.49
0.13
0.45
0.25
0.09
0.69
-0.29
-0.43
0.12
0.32
0.32
0.12
0.79
-0.35
-0.49
0.12
0.40
-0.30
-0.19
-0.50
0.24
0.30
-0.04
-0.35
-0.63
-0.16
-0.27
0.02
0.11
0.07
-0.49
-0.12
-0.06
0.05
-0.15
-0.19
-0.15
-0.07
Sioux Falls, South Dakota - SFSD
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
59
58
59
51
59
59
-0.24
0.50
-0.06
-0.18
0.31
-0.20
-0.28
0.52
-0.06
-0.20
0.32
-0.21
-0.30
0.54
0.01
-0.14
0.33
-0.22
-0.30
0.54
-0.03
-0.18
0.33
-0.22
-0.06
-0.02
0.32
0.33
-0.01
-0.03
0.19
-0.26
-0.05
0.03
-0.21
0.16
-0.28
-0.15
-0.36
-0.10
0.05
-0.01
to
oo
-------
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 24-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Acrolein and formaldehyde exceeded one or more
of the MRL risk values.
Observations about acrolein in Table 24-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• For both sites, all of the seasonal averages of acrolein exceeded the intermediate
MRL.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
Observations about formaldehyde from Table 24-7 include the following:
• One measured detection (out of 59) from SFSD (78.61ug/m3) exceeded the ATSDR
acute MRL for formaldehyde (50 |ig/m3).
• One other site (INDEM) exceeded the ATSDR acute MRL for formaldehyde;
however, only one of the 16 total program exceedances occurred at SFSD.
• None of the seasonal averages of formaldehyde for SFSD exceeded the ATSDR
intermediate MRL for formaldehyde (40 |ig/m3). However, it is easy to see from the
confidence interval of the winter average that the concentration that exceeded the
acute MRL was measured during winter.
• The annual average of formaldehyde for SFSD did not exceed the ATSDR
intermediate MRL for formaldehyde (10 |ig/m3).
For the pollutants that exceeded the acute risk factors, the concentrations were further
examined by developing pollution roses for these pollutants. A pollution rose is a plot of
concentration and wind direction, as described in Section 3.6.1. Figure 24-17 is the pollution
rose for formaldehyde for SFSD, where the acute risk factor for formaldehyde was exceeded.
24-32
-------
Table 24-7. MRL Risk Screening Assessment Summary for the South Dakota Monitoring Sites
Site
CUSD
SFSD
SFSD
Method
TO-15
TO-15
TO-11A
Pollutant
Acrolein
Acrolein
Formaldehyde
ATSDR
Acute
MRL
(Ug/m3)
7.00
7.00
50.00
#of
Exceedances/
#of
Measured
Detections
0/60
0/58
1/59
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
0.09
40
Winter
Average
(Ug/m3)
0.49
±0.16
0.34
±0.09
7.19
± 10.38
Spring
Average
(Ug/m3)
0.42
±0.09
0.55
±0.15
2.28
±0.34
Summer
Average
(Ug/m3)
0.72
±0.19
0.79
±0.21
3.09
±0.39
Autumn
Average
(Ug/m3)
0.71
±0.30
0.53
±0.14
2.01
±0.33
ATSDR
Chronic
MRL
(Ug/m3)
—
~
10.00
Annual
Average1
(Ug/m3)
0.59
±0.10
0.55
±0.09
3.57
±2.52
BOLD = exceedance of the intermediate or chronic MRL
- = an MRL risk factor is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
-j^
oo
-------
Figure 24-17. Formaldehyde Pollution Rose for SFSD
to
-^
oo
80.0
70.0
60.0
50.0
40.0
"g 30.0
"5)
5 20.0
c
110-°
o.o
o 10-°
g 20.0
"5 30.0
Q.
40.0
50.0
60.0
70.0
80.0
NW
W
sw
_ ATSDR MRL (50 |jg/m3)
NE
Daily Avg Cone = 3.57 ± 2.52 |jg/m
SE
80.0
70.0
60.0 50.0 40.0 30.0 20.0 10.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0
Pollutant Concentration ([jg/m )
-------
Observations from the pollution rose include the following:
• The exceedance of the ATSDR acute MRL for formaldehyde occurred with a
westerly wind.
• The highest concentration was significantly higher than all other measured
concentrations. The pollution rose shows that this concentration is a true "outlier",
deviating significantly from all the other measurements and supporting the
observations in Section 24.4.1.
24.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the South Dakota monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 24-8. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the South Dakota sites is as follows:
• The census tract for CUSD is 46033995100, which had a population of 4,517, and
represented approximately 62 percent of the Custer County population in 2000.
• The census tract for SFSD is 46099001802, which had a population of 7,498, and also
represented approximately 5.1 percent of the county population in 2000.
Observations for CUSD from Table 24-8 include the following:
• The pollutants with the highest concentrations according to NATA were
acetaldehyde, formaldehyde, and benzene, although all three modeled concentrations
were less than 1 |ig/m3.
• Only two pollutants had cancer risks exceeding 1 in-a-million according to NATA,
benzene and carbon tetrachloride.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (1.10). Most HQs were 0.01 or less.
24-35
-------
Table 24-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in South Dakota
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk (HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer Risk
Approximation
(HQ)
Custer, South Dakota (CUSD) - Census Tract ID 46033995100
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
1 ,2-Dichloroethane
Dichloromethane
Formaldehyde
w-Hexane
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Trichloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000011
0.000026
0.00000047
5.5E-09
—
0.000058
0.000005
0.000002
0.009
0.00002
0.002
0.03
0.002
0.04
0.8
2.4
1
0.0098
0.2
—
0.27
0.6
0.42
0.02
<0.01
0.22
0.01
0.21
0.01
<0.01
0.01
0.27
0.01
O.01
0.01
0.03
0.93
—
O.01
1.70
0.17
3.16
0.01
O.01
0.01
O.01
—
O.01
0.01
0.06
0.04
1.10
O.01
0.01
O.01
0.01
0.01
O.01
0.01
0.02
0.01
—
0.01
O.01
1.91 ±0.32
0.59 ±0.10
0.11 ±0.03
0.66 ±0.13
0.07 ± 0.02
0.55 ±0.04
0.05 ±0.01
0.04 ±O.01
4.43 ±8. 14
2.03 ±0.31
1.57 ±1.12
0.06 ±O.01
0.06 ±0.01
0.09 ±0.07
3.82
—
7.47
4.65
2.00
8.26
0.53
1.13
2.08
0.01
—
3.24
0.29
0.19
0.21
29.27
0.05
0.02
0.03
0.01
0.01
O.01
0.01
0.21
0.01
—
0.01
O.01
Sioux Falls, South Dakota (SFSD) - Census Tract ID 46099001802
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
1 ,2-Dichloroethane
Formaldehyde
Tetrachloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000026
5.5E-09
0.000005
0.009
0.00002
0.002
0.03
0.002
0.04
2.4
0.0098
0.27
0.67
0.02
O.01
0.69
0.06
0.21
0.03
0.80
0.08
1.50
—
0.01
5.41
1.81
3.11
0.66
0.01
0.51
0.07
1.20
O.01
0.02
0.03
0.01
O.01
0.08
O.01
1.55 ±0.23
0.55 ±0.09
0.04 ±0.01
0.55 ±0.07
0.04 ±0.01
0.57 ±0.04
0.04 ±O.01
3.57 ±2.52
0.07 ±0.01
3.10
—
2.48
3.87
1.20
8.54
1.11
0.02
0.37
0.17
27.60
0.02
0.02
0.02
0.01
O.01
0.36
O.01
to
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
• The pollutants with the highest annual averages were dichloromethane,
formaldehyde, and acetaldehyde.
• The pollutants with the highest cancer risk approximations were carbon tetrachloride.
acrylonitrile, and benzene.
• Similar to the NATA results, acrolein was the only pollutant with a noncancer risk
approximation greater than 1.0. However, the noncancer risk approximation was an
order of magnitude higher than NATA (29.27).
Observations for SFSD from Table 24-8 include the following:
• The pollutants with the highest concentrations according to NATA were
formaldehyde, benzene, and acetaldehyde, although all three modeled concentrations
were less than 1 |ig/m3.
• The pollutants with the highest cancer risks according to NATA were benzene,
carbon tetrachloride, and 1,3-butadiene.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (1.20).
• The pollutants with the highest annual averages were formaldehyde, acetaldehyde,
and carbon tetrachloride.
• The pollutants with the highest cancer risk approximations were carbon tetrachloride,
benzene, and acetaldehyde.
• Similar to the NATA results, acrolein was the only pollutant with a noncancer risk
approximation greater than 1.0. However, the noncancer risk approximation was an
order of magnitude higher than NATA (27.60).
24.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 24-9 and 24-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 24-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 24-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
24-37
-------
Table 24-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in South Dakota
to
oo
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Custer, South Dakota (CUSD) - Custer County
Benzene
Formaldehyde
Acetaldehyde
Tetrachloroethylene
1,3 -Butadiene
Dichloromethane
Naphthalene
POM, Group 2
£>-Dichlorobenzene
POM, Group 6
14.72
4.93
2.22
1.57
1.14
0.55
0.43
0.34
0.15
0.03
Benzene
1,3 -Butadiene
POM, Group 2
Naphthalene
POM, Group 3
Tetrachloroethylene
POM, Group 5
Acetaldehyde
Hexavalent Chromium
POM, Group 6
1.15E-04
3.42E-05
1.86E-05
1.46E-05
1.02E-05
9.29E-06
6.44E-06
4.88E-06
3.49E-06
3.07E-06
Carbon Tetrachloride
Acrylonitrile
Benzene
Acetaldehyde
1 , 1 ,2,2-Tetrachloroethane
Dichloromethane
1,3 -Butadiene
1 ,2-Dichloroethane
£>-Dichlorobenzene
Tetrachloroethylene
8.26
7.46
4.65
3.82
3.24
2.08
2.00
1.13
0.53
0.29
Sioux Falls, South Dakota (SFSD) - Minnehaha County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Tetrachloroethylene
Naphthalene
/>-Dichlorobenzene
POM, Group 2
Trichloroethylene
134.64
52.48
23.70
12.30
11.96
6.03
4.20
3.27
2.39
1.03
Benzene
1,3 -Butadiene
Naphthalene
POM, Group 2
Arsenic, PM
Hexavalent Chromium
POM, Group 3
Acetaldehyde
Ethylene oxide
/>-Dichlorobenzene
1.05E-03
3.69E-04
1.43E-04
1.31E-04
1.06E-04
8.52E-05
8.08E-05
5.21E-05
3.69E-05
3.60E-05
Carbon Tetrachloride
Benzene
Acetaldehyde
Acrylonitrile
1,3 -Butadiene
1 ,2-Dichloroethane
Tetrachloroethylene
Formaldehyde
8.54
3.87
3.10
2.46
1.20
1.11
0.37
0.02
-------
Table 24-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in South Dakota
to
-^
OJ
VO
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Custer, South Dakota (CUSD) - Custer County
Toluene
Xylenes
Benzene
Ethylbenzene
Formaldehyde
Hexane
Methanol
Acetaldehyde
Styrene
Tetrachloroethylene
34.00
24.60
14.72
5.76
4.93
4.71
2.47
2.22
1.69
1.57
Acrolein
1,3 -Butadiene
Formaldehyde
Benzene
Cyanide Compounds, gas
Acetaldehyde
Xylenes
Naphthalene
Toluene
Hydrochloric acid
14,414.57
569.89
502.87
490.55
290.00
246.22
246.05
142.70
85.01
30.03
Acrolein
Acetaldehyde
Formaldehyde
Acrylonitrile
1,3 -Butadiene
Benzene
Carbon Tetrachloride
n -Hexane
Dichloromethane
Tetrachloroethylene
29.27
0.21
0.21
0.05
0.03
0.02
0.01
0.01
0.01
O.01
Sioux Falls, South Dakota (SFSD) - Minnehaha County
Toluene
Xylenes
Benzene
Methanol
Hydrochloric acid
Formaldehyde
Ethylbenzene
Hexane
Styrene
Acetaldehyde
320.93
237.78
134.64
85.64
63.20
52.48
47.42
41.20
28.07
23.70
Acrolein
1,3 -Butadiene
Formaldehyde
Benzene
Hydrochloric acid
Acetaldehyde
Xylenes
Cyanide Compounds, gas
Naphthalene
Nickel, PM
136,549.28
6,149.18
5,355.37
4,487.86
3,160.01
2,633.20
2,377.78
1,873.33
1,399.74
1,315.70
Acrolein
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Benzene
Acrylonitrile
Carbon Tetrachloride
Tetrachloroethylene
1 ,2-Dichloroethane
27.60
0.36
0.17
0.02
0.02
0.02
0.01
0.01
0.01
-------
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 24.3, CUSD and SFSD sampled
for VOC, SNMOC, and carbonyl compounds. In addition, the cancer and noncancer risk
approximations are limited to those sites sampling for a long enough period for annual averages
to be calculated.
Observations from Table 24-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in both Custer and Minnehaha Counties; although the emissions were an
order of magnitude higher in Minnehaha County.
• Benzene and 1,3-butadiene were the pollutants with the highest toxicity-weighted
emissions (of the pollutants with cancer UREs) for both counties.
• Seven of the highest emitted pollutants also had the highest toxicity-weighted
emissions for Custer County; six of the highest emitted pollutants also had the highest
toxicity-weighted emissions for Minnehaha County.
• Carbon tetrachloride was the pollutant with the highest cancer surrogate risk
approximation for each site, yet appeared on none of the emissions-based lists.
• Benzene, acetaldehyde, and 1,3-butadiene appeared on all three lists for SFSD. These
three pollutants and tetrachloroethylene appeared on all three lists for CUSD.
Observations from Table 24-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Custer and Minnehaha Counties, although the emissions were an order of
magnitude higher in Minnehaha County.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, 1,3-butadiene, and formaldehyde for both counties.
• Five of the highest emitted pollutants also had the highest toxicity-weighted
emissions.
24-40
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• Acrolein, which had the highest noncancer risk approximations, also had the highest
toxicity-weighted emissions for both sites.
24.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each South Dakota monitoring site were
acetaldehyde, acrolein, benzene, 1,3-butadiene, carbon tetrachloride, and
formaldehyde.
»«» Formaldehyde had the highest daily average concentration for each of the sites.
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmark for
both sites; one concentration of formaldehyde exceeded the acute MRL health
benchmark for SFSD.
24-41
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25.0 Sites in Tennessee
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the UATMP sites in Tennessee, and integrates these concentrations
with emissions, meteorological, and risk information.
25.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the locations of the sites and the surrounding areas. The LDTN and MSTN
monitoring sites are located in Loudon, southwest of Knoxville. Loudon is within the Knoxville,
TN MSA. Figures 25-1 and 25-2 are composite satellite images retrieved from Google™ Maps
showing the monitoring sites in their rural locations. Figure 25-3 identifies point source
emission locations within 10 miles of each site as reported in the 2002 NEI for point sources.
Table 25-1 describes the area surrounding each monitoring site and provides supplemental
geographical information such as land use, location setting, and locational coordinates.
A branch of the Tennessee River, Watts Bar Lake, winds through the town of Loudon.
LDTN is located in an area where the river is less than a half mile to the east, south, and west.
The site is located in a primarily residential area on Webb Drive, a few blocks from Highway 11,
as shown in Figure 25-1. However, several industrial businesses lie along the river on Blair
Bend Drive, less than a half mile south of the site. The site was established to capture emissions
from nearby industrial sources.
MSTN is located on the property of Loudon Middle School, between Highway 74 and
Roberts Road. Although a residential subdivision is located immediately across the street from
the middle school, as shown in Figure 25-2, mixed land use areas lie to the north and northeast
while rural and forested areas lie to the south. This site was also established to capture emissions
from nearby industrial sources.
Figure 25-3 shows that the two Tennessee monitoring sites are fairly close to each other.
The LDTN and MSTN monitoring sites have nearly two dozen point sources nearby. Several of
25-1
-------
Figure 25-1. Loudon, Tennessee (LDTN) Monitoring Site
to
v\
to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 25-2. Loudon, Tennessee (MSTN) Monitoring Site
to
OJ
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 25-3. NEI Point Sources Located Within 10 Miles of LDTN and MSTN
i
trsrtivt UMSOW
M«e. Due us hall) dwifly tnd esfloeiUwi. n» total tttiBK*
L£d EDC) <*i?l*?td m »y net rtfirtwK *i f»cnit»i win-in Hi* »r»« «l ntm-sl
•jif LDTN UATM P site
lir MSTN UATMP site
10 mile radius
| County boundary
Source Category Group (No. of Facilities)
c Chemicals & Allied Products Facility (1)
F Fuel Combustion Industrial Facility (6)
t- Integrated Iron & Steel Manufacturing Facility (1)
\ Non-ferrous Metals Processing Industrial Facility (1)
v Polymers & Resins Production Industrial Facility (4)
Y Rubber & Miscellaneous Plastic Products Facility (1)
u Stone, Clay, Glass, & Concrete Products (2)
s Surface Coating Processes Industrial Facility (1)
i Waste Treatment & Disposal Industrial Facility (4)
25-4
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Table 25-1. Geographical Information for the Tennessee Monitoring Sites
Site
Code
LDTN
MSTN
AQS Code
47-105-0108
47-105-0109
Location
Loudon
Loudon
County
Loudon
Loudon
Micro- or
Metropolitan
Statistical Area
Knoxville, TN
Knoxville, TN
Latitude
and
Longitude
35.7447,
-84.3174
35.720833,
-84.341667
Land Use
Residential
Residential
Location
Setting
Suburban
Suburban
Description of the
Immediate Surroundings
The site was set up due to public concern about air
emissions from several sources in an industrial
park. Among these sources is a very large facility
that processes corn to make corn syrup, a sausage
casing manufacturer, boat manufacturer, paper
products manufacturer, waste metal reclamation,
waste paper reclamation, and others.
The second site at Loudon Middle School in
Loudon, TN, was set up due to public concern about
air emissions from several sources in an industrial
park. This site is S W of the LDTN site and upwind
of the industrial sources.
to
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these emission sources are involved in waste treatment and disposal, polymer and resin
production, or fuel combustion processes.
Table 25-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Tennessee monitoring sites. County-level vehicle registration and population data for Loudon
County, Tennessee were obtained from the Tennessee Department of Safety and the U.S. Census
Bureau. Table 25-2 also includes a vehicle registration to county population ratio (vehicles per
person). In addition, the population within 10 miles of each site is presented. An estimate of 10-
mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 25-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 25-2 presents the daily VMT for each
urban area.
Table 25-2. Population, Motor Vehicle, and Traffic Information for the Tennessee
Monitoring Sites
Site
LDTN
MSTN
2007
Estimated
County
Population
45,448
45,448
Number
of
Vehicles
Registered
50,519
50,519
Vehicles
per Person
(Registration:
Population)
1.11
1.11
Population
Within
10 Miles
50,501
50,501
Estimated
10-mile
Vehicle
Ownership
56,136
56,136
Annual
Average
Traffic
Data1
12,945
7,287
VMT
(thousands)
16,430
16,430
Daily Average Traffic Data reflects 2006 data from the Tennessee DOT
Observations from Table 25-2 include the following:
• Loudon County had the seventh lowest county population and seventh lowest county-
level vehicle registration compared to all counties with NATTS or UATMP sites.
• The 10-mile radius populations were the same because these sites are located in the
same zip code. The 10-mile population for these sites was the ninth lowest among
NATTS and UATMP sites.
• The vehicle per person ratio for these sites was greater then one vehicle per person,
and the sixth highest compared to other NATTS or UATMP sites.
• LDTN experienced a higher average daily traffic volume than MSTN, although both
traffic volumes were in the lowest-third compared to other program sites. LDTN
25-6
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traffic volume was obtained from Highway 11 before it crosses the river (TN DOT
station 056). Traffic for MSTN was also obtained from Highway 11, near the
intersection with State Road 72 (TN DOT station 122).
• The Knoxville area VMT ranked eighth lowest among urban areas with UATMP or
NATTS sites.
25.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Tennessee on sampling days, as well as over the course of the year.
25.2.1 Climate Summary
Loudon is located to the southwest of Knoxville in east Tennessee. Loudon is located in
a valley, which is divided from the rest of the state by the Cumberland Plateau. The Appalachian
and Great Smoky Mountains lie to the east and the Cumberland and Crab Orchard Mountains lie
to the northwest. The Tennessee River meanders through the town of Loudon. These
topographic influences affect the area's weather by moderating temperatures and affecting wind
patterns. The area has ample rainfall year-round and experiences all four seasons (Ruffner and
Bair, 1987 and TGA, 1997).
25.2.2 Meteorological Conditions in 2007
Hourly meteorological data at the weather station near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air concentration measurements.
The closest NWS weather station to both sites is located at McGhee Tyson Airport (WBAN
13891).
Table 25-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and relative humidity), pressure
(average sea level pressure), and wind information (average scalar wind speed) on days samples
were collected and for the entire year. Also included in Table 25-3 is the 95 percent confidence
25-7
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Table 25-3. Average Meteorological Conditions near the Tennessee Monitoring Sites
Site
LDTN
MSTN
Closest NWS
Station and
WBAN
McGhee Tyson
Airport
13891
McGhee Tyson
Airport
13891
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
73.83
±4.19
71.74
±1.76
73.38
±4.17
71.74
±1.76
Average
Temperature
(op)
63.19
±3.92
60.06
± 1.68
62.68
±3.88
60.06
±1.68
Average
Dew Point
Temperature
(°F)
48.76
±4.07
46.85
±1.73
48.40
±4.07
46.85
±1.73
Average
Wet Bulb
Temperature
(»F)
55.37
±3.52
53.54
±1.51
54.99
±3.50
53.54
±1.51
Average
Relative
Humidity
(%)
62.70
±2.75
63.08
± 1.23
62.99
±2.83
63.08
±1.23
Average
Sea Level
Pressure
(mb)
1018.08
±1.30
1018.27
±0.53
1018.26
± 1.29
1018.27
±0.53
Average
Scalar Wind
Speed
(kt)
4.73
±0.64
4.95
±0.28
4.72
±0.65
4.95
±0.28
to
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interval for each parameter. As shown in Table 25-3, average meteorological conditions on
sampling days were fairly representative of average weather conditions throughout the year.
Although the average and maximum temperature appear slightly warmer on sampling days, the
confidence interval suggests that the difference is not significant.
25.2.3 Composite Back Trajectories for Sampling Days
Figures 25-4 and 25-5 are composite back trajectory maps for the Tennessee monitoring
sites for the days on which samples were collected. Each line represents the 24-hour trajectory
along which a parcel of air traveled toward the monitoring site on a sampling day. Each
concentric circle around the sites in Figures 25-4 and 25-5 represents 100 miles.
Observations from Figures 25-4 and 25-5 include the following:
• The back trajectory maps for LDTN and MSTN look very similar.
• Back trajectories originated from a variety of directions at the sites, although less
frequently from the northwest, north, and northeast.
• The 24-hour air shed domains for these sites were similar in size compared to most
other monitoring sites. The furthest away a trajectory originated was southern
Wisconsin, or approximately 800 miles away. However, 75 percent of the trajectories
originated within 300 miles of the sites.
25.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather station at McGhee Tyson Airport near LDTN and
MSTN were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce
customized wind roses. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figures 25-6 and 25-7 are the
wind roses for the Tennessee monitoring sites on days that samples were collected.
Observations from Figures 25-6 and 25-7 include the following:
• The wind roses for LDTN and MSTN are nearly identical. This is expected though,
as the wind data are from the same weather station and these sites collected samples
primarily on the same days.
• Calm winds were observed for approximately 31 percent of the hourly measurements.
25-9
-------
Figure 25-4. Composite Back Trajectory Map for LDTN
to
v\
I
—1
o
7/7 '/v
/ Ai
/ '
/ / /
-------
Figure 25-5. Composite Back Trajectory Map for MSTN
to
v\
I
-------
Figure 25-6. Wind Rose for LDTN Sampling Days
SOUTH .--'
WIND SPEED
(Knots)
EH >=Z2
^| 17 - 21
• 11 • 17
• 7- 11
CH 1-7
Calms: 30.61%
Figure 25-7. Wind Rose for MSTN Sampling Days
25-12
-------
• For winds greater than two knots, southwesterly winds were prevalent.
• Winds exceeding 11 knots made up approximately eight percent of observations and
were most often out of the southwest or west.
25.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Tennessee
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 25-4 presents the pollutants that failed at least one screen for each Tennessee monitoring
site and highlights each site's pollutants of interest (shaded). LDTN and MSTN sampled for
VOC and carbonyl compounds.
Observations from Table 25-4 include the following:
• Eleven pollutants failed at least one screen for both LDTN and MSTN. A total of 387
measured concentrations failed screens for LDTN, while 350 failed screens for
MSTN.
• The pollutants of interest varied by site, yet the following six pollutants of interest
were common to both sites: acetaldehyde, acrolein, benzene, 1,3-butadiene, carbon
tetrachloride, and formaldehyde.
• Of the six common pollutants of interest, 100 percent of the measured detections of
acetaldehyde, acrolein, benzene, and carbon tetrachloride failed screens for both
LDTN and MSTN.
25.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Tennessee monitoring sites. The averages presented are provided for the pollutants of
interest for each site. Complete site-specific statistical summaries are provided in Appendices J
25-13
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Table 25-4. Comparison of Measured Concentrations and EPA Screening Values for
the Tennessee Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Loudon, Tennessee - LDTN
Acetaldehyde
Formaldehyde
Acrolein
Benzene
Carbon Tetrachloride
1,3 -Butadiene
p-Dichlorobenzene
Carbon Bisulfide
Tetrachloroethylene
Acrylonitrile
Xylenes
Total
62
62
60
60
59
49
15
10
4
4
2
387
62
62
60
60
60
58
57
60
53
4
60
596
100.00
100.00
100.00
100.00
98.33
84.48
26.32
16.67
7.55
100.00
3.33
64.93
16.02
16.02
15.50
15.50
15.25
12.66
3.88
2.58
1.03
1.03
0.52
16.02
32.04
47.55
63.05
78.29
90.96
94.83
97.42
98.45
99.48
100.00
Loudon Middle School, Loudon, Tennessee - MSTN
Acrolein
Benzene
Acetaldehyde
Carbon Tetrachloride
Formaldehyde
1,3 -Butadiene
Acrylonitrile
£>-Dichlorobenzene
Tetrachloroethylene
Chloromethylbenzene
1 ,2-Dichloroethane
Total
60
60
59
59
55
45
4
3
3
1
1
350
60
60
59
59
59
55
4
55
58
1
1
471
100.00
100.00
100.00
100.00
93.22
81.82
100.00
5.45
5.17
100.00
100.00
74.31
17.14
17.14
16.86
16.86
15.71
12.86
1.14
0.86
0.86
0.29
0.29
17.14
34.29
51.14
68.00
83.71
96.57
97.71
98.57
99.43
99.71
100.00
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at each site, where applicable.
25.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
25-14
-------
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 25-5, where applicable.
Table 25-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Tennessee Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Ug/m3)
Winter
Average
(Ug/m3)
Spring
Average
(Ug/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Ug/m3)
Annual
Average1
(Ug/m3)
Loudon, Tennessee - LDTN
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
62
60
60
58
60
60
57
62
62
60
60
60
60
60
60
62
2.62
±0.42
0.70
±0.14
0.78
±0.09
0.06
±0.01
46.96
±11.56
0.61
±0.04
0.09
±0.03
3.74
±0.64
1.42
±0.24
0.47
±0.18
0.83
±0.23
0.08
±0.03
33.79
± 27.04
0.53
±0.12
0.05
±0.01
1.55
±0.21
3.21
±1.01
0.44
±0.12
0.64
±0.11
0.05
±0.02
65.04
±31.6
0.65
±0.06
0.05
±0.01
2.90
±0.73
3.49
±0.79
0.95
±0.32
0.78
±0.18
0.05
±0.01
40.60
± 10.66
0.64
±0.07
0.14
±0.08
6.02
±1.00
2.01
±0.49
0.88
±0.32
0.88
±0.14
0.06
±0.01
48.00
± 18.32
0.60
±0.05
0.08
±0.02
3.72
±1.43
2.62
±0.42
0.70
±0.14
0.78
±0.09
0.06
±0.01
46.96
±11.56
0.61
±0.04
0.09
±0.03
3.74
±0.64
Loudon Middle School, Loudon, Tennessee - MSTN
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
59
60
60
55
59
59
59
60
60
60
60
59
1.49
±0.16
0.75
±0.10
0.87
±0.16
0.06
±0.01
0.58
±0.03
2.93
±0.45
1.16
±0.28
0.63
±0.13
1.25
±0.38
0.08
±0.03
0.49
±0.08
1.35
±0.24
1.67
±0.25
0.67
±0.15
0.64
±0.11
0.05
±0.01
0.57
±0.06
2.21
±0.27
1.82
±0.38
0.87
±0.25
0.63
±0.13
0.04
±0.01
0.62
±0.07
4.92
±0.80
1.25
±0.19
0.81
±0.24
1.01
±0.41
0.06
±0.02
0.60
±0.04
2.89
±0.74
1.49
±0.16
0.75
±0.10
0.87
±0.16
0.05
±0.01
0.57
±0.03
2.93
±0.45
1 An annual average was calculated
number of corresponding seasonal
for the pollutants presented in this table without regard to the detection rate or
averages. Program completeness and sampling duration criteria were applied.
25-15
-------
Observations for LDTN from Table 25-5 include the following:
• The pollutants with the highest daily average concentrations by mass were carbon
disulfide (46.96 ± 11.56 |ig/m3), formaldehyde (3.74 ± 0.64 |ig/m3), and acetaldehyde
(2.62 ± 0.42 |ig/m3).
• The daily, seasonal, and annual average concentrations of carbon disulfide are
significantly higher than the averages for the other pollutants of interest.
• As shown in Tables 4-9 and 4-11, of the program-level pollutants of interest, LDTN
had the ninth highest daily average concentration of acetaldehyde and the tenth
highest daily average concentration of formaldehyde and tetrachloroethylene.
• The daily average concentration of carbon disulfide was the highest average
concentration for this pollutant of all NATTS and UATMP sites.
• Although some of the seasonal averages of the pollutants of interest for LDTN appear
to be higher in the summer or autumn, the confidence intervals indicate that the
difference is not significant.
Observations for MSTN from Table 25-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (2.93 ± 0.45 |ig/m3), acetaldehyde (1.49 ± 0.16 |ig/m3), and benzene
(0.87±0.16|ig/m3).
• Although carbon disulfide was not a pollutant of interest for MSTN, the daily average
concentration of carbon disulfide was 4.21 ±1.31 |ig/m3, which is an order of
magnitude lower than the average for LDTN. The daily average of this pollutant was
the tenth highest among of sites sampling VOC.
• None of the daily average concentrations of the program-level pollutants for MSTN
were among the 10 highest concentrations for all sites, as shown in Table 4-9.
• Although some of the seasonal averages of the pollutants of interest for MSTN appear
to be higher in the summer or autumn, the confidence intervals indicate that the
difference is not significant. However, formaldehyde concentrations were highest in
the summer.
25.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. The LDTN site has sampled VOC and carbonyls under the UATMP
25-16
-------
since 2003. Figures 25-8 through 25-10 present the three-year rolling statistical metrics
graphically for benzene, 1,3-butadiene, and formaldehyde for LDTN. The statistical metrics
presented for calculating trends include the substitution of zeros for non-detects.
Observations from Figure 25-8 for benzene measurements include the following:
• The maximum benzene concentration shown was measured in 2004.
• The median and rolling average concentrations have a decreasing trend over the time
periods shown.
• The minimum concentration measured decreased for each time frame.
• All benzene concentrations reported to AQS over the five years of sampling were
measured detections.
Observations from Figure 25-9 for 1,3-butadiene measurements include the following:
• The minimum, first quartile, and median concentrations for 1,3-butadiene were zero
for the 2003-2005 time frame. As the MDL for 1,3-butadiene improved (i.e,
decreased), the detection rate for this pollutant increased, and a larger spread between
the metrics is observed. This pollutant was detected in 31 percent of samples during
the 2003-2005 time frame; 59 percent of samples during 2004-2006; and 86 percent
of samples during 2005-2007.
• The rolling average concentration, the median, and the third quartile increased over
the sampling periods, primarily due to the decreasing number of zeros incorporated
into the calculations.
Observations from Figure 25-10 for formaldehyde measurements include the following:
• The maximum formaldehyde concentration shown was measured in 2003. The
maximum concentrations have decreased across the sampling period.
• The rolling average concentration is greater than the third quartile for the 2003-2005
time frame, illustrating the effects of outliers in the calculation.
• The median and rolling average concentrations became more similar each period,
indicating decreasing variability in central tendency since sampling began in 2003.
• The rolling average concentrations exhibited a decreasing trend over the sampling
period.
25-17
-------
Figure 25-8. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at LDTN
to
oo
1.20
1.00
0.80
.o
o.
o.
^-^
=
I 0.60
=
01
-------
Figure 25-9. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at LDTN
to
0.18
0.16
0.14
0.12
0.10
=
.0
*
0.08
=
o
U
0.06
0.04
0.02 -
2003-2005
2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 25-10. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at LDTN
to
to
o
45.00 i
40.00
35.C
30.00 -
.o
o.
o.
25.00
§ 20.00
=
o
U
15.00 -
10.00
0.00
<
•
>
•
1 I
2003-2005 2004-2006 2005-2007
Three- Year Period
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
• All formaldehyde concentrations reported to AQS over the six years of sampling were
measured detections.
25.5 Pearson Correlations
Table 25-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for LDTN from Table 25-6 include the following:
• Formaldehyde and acetaldehyde exhibited strong positive correlations with the
temperature parameters, indicating that as the temperature increases, concentrations
of these pollutants proportionally increase at LDTN.
• Formaldehyde also exhibited strong positive correlations with the dew point and wet
bulb temperatures, indicating that as these parameters increase, concentrations of
formaldehyde proportionally increase at LDTN.
• Although not very strong, all of the correlations with scalar wind speed were
negative, indicating that decreasing wind speed may result in a proportionate
increases in the pollutants of interest at LDTN.
Observations for MSTN from Table 25-6 include the following:
• Formaldehyde exhibited similar tendencies at MSTN, with strong positive
correlations with average, maximum, dew point, and wet bulb temperatures.
• Similar to LDTN, the correlations between the pollutants of interest and scalar wind
speed were all negative.
25.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
25.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Tennessee
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
25-21
-------
Table 25-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Tennessee
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Loudon, Tennessee - LDTN
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
62
60
60
58
60
60
57
62
0.56
0.36
0.05
-0.13
0.22
0.33
0.30
0.77
0.53
0.35
0.03
-0.15
0.13
0.31
0.29
0.78
0.39
0.32
0.06
-0.12
0.06
0.36
0.27
0.65
0.45
0.33
0.03
-0.15
0.09
0.33
0.28
0.71
-0.29
0.02
0.14
0.12
-0.17
0.28
0.02
-0.18
-0.18
-0.13
0.09
0.27
0.03
-0.29
-0.08
-0.30
-0.21
-0.10
-0.41
-0.42
-0.17
-0.18
-0.06
-0.28
Loudon Middle School, Loudon, Tennessee - MSTN
Acetaldehyde
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
59
60
60
55
59
59
0.43
0.27
-0.30
-0.36
0.24
0.80
0.40
0.23
-0.32
-0.35
0.22
0.80
0.20
0.24
-0.20
-0.24
0.19
0.66
0.29
0.23
-0.27
-0.31
0.21
0.73
-0.46
0.13
0.30
0.27
0.00
-0.16
-0.08
0.08
0.17
0.25
-0.10
-0.26
-0.22
-0.40
-0.16
-0.23
-0.01
-0.28
to
to
to
-------
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 25-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein in Table 25-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• For both sites, all of the seasonal averages of acrolein exceeded the intermediate
MRL.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
25.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Tennessee monitoring sites and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 25-8. The
data from NATA are presented for the census tract where each monitoring site is located. The
pollutants of interest for each site are bolded.
The census tract information for the Tennessee monitoring sites is as follows:
• The census tract for LDTN is 47105060200, which had a population of 9,529, and
represented approximately 24.4 percent of the Loudon County population in 2000.
• The census tract for MSTN is 47105060500, which had a population of 7,898, and
also represented approximately 20.2 percent of the county population in 2000.
25-23
-------
to
v\
to
Table 25-7. MRL Risk Screening Assessment Summary for the Tennessee Monitoring Sites
Site
LDTN
MSTN
Method
TO-15
TO-15
Pollutant
Acrolein
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/60
0/60
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
0.09
Winter
Average
(Ug/m3)
0.47
±0.18
0.63
±0.13
Spring
Average
(Ug/m3)
0.44
±0.12
0.67
±0.15
Summer
Average
(Ug/m3)
0.95
±0.32
0.87
±0.25
Autumn
Average
(Ug/m3)
0.88
±0.32
0.81
±0.24
ATSDR
Chronic
MRL
(Ug/m3)
—
-
Annual
Average1
(Ug/m3)
0.70
±0.14
0.75
±0.10
BOLD = exceedance of the intermediate or chronic MRL
~ = an MRL risk factor is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
Table 25-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Tennessee
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(jig/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Loudon, Tennessee (LDTN) - Census Tract ID 47105060200
Acet aldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Disulfide
Carbon Tetrachloride
p-Dichlorobenzene
Formaldehyde
Tetrachloroethylene
Xylenes
0.000002
~
0.000068
0.000007
0.00003
—
0.000015
0.000011
5.5E-09
0.000005
—
0.009
0.00002
0.002
0.03
0.002
0.7
0.04
0.8
0.0098
0.27
0.1
1.21
0.06
0.01
0.89
0.03
3.84
0.21
0.01
0.78
0.02
1.15
2.69
~
0.06
6.94
0.76
—
3.18
0.16
<0.01
0.14
—
0.13
2.99
0.01
0.02
0.01
0.01
0.01
0.01
0.07
0.01
0.01
2.62 ± 0.42
0.70 ±0.14
0.03 ±0.01
0.78 ±0.09
0.06 ±0.01
46.96 ±11.56
0.61 ±0.04
0.09 ±0.03
3.74 ±0.64
0.26 ±0.33
1.06 ±0.69
5.24
~
2.05
5.45
1.76
—
9.15
0.94
0.02
1.30
—
0.29
35.10
0.02
0.03
0.03
0.07
0.02
0.01
0.38
0.01
0.01
Loudon Middle School, Loudon, Tennessee (MSTN) - Census Tract ID 47105060500
Acetaldehyde
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
Chloromethylbenzene
£>-Dichlorobenzene
1 ,2-Dichloroethane
Formaldehyde
Tetrachloroethylene
0.000002
—
0.000068
0.000007
0.00003
0.000015
0.000049
0.000011
0.000026
5.5E-09
0.000005
0.009
0.00002
0.002
0.03
0.002
0.04
~
0.8
2.4
0.0098
0.27
1.04
0.05
O.01
0.72
0.02
0.21
O.01
0.01
0.01
0.73
0.01
2.31
—
0.04
5.59
0.47
3.15
O.01
0.12
0.26
0.01
0.09
0.11
2.39
O.01
0.02
0.01
0.01
~
0.01
O.01
0.07
O.01
1.49 ±0.16
0.75 ±0.10
0.03 ±O.01
0.87 ±0.16
0.05 ±0.01
0.57 ±0.03
0.03 ± O.01
0.05 ±0.01
0.04 ±O.01
2.93 ±0.45
0.09 ±0.02
2.98
—
1.88
6.12
1.63
8.59
1.39
0.59
1.10
0.02
0.45
0.17
37.49
0.01
0.03
0.03
0.01
~
0.01
O.01
0.30
O.01
to
v\
to
BOLD = pollutant of interest
- = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
-------
Observations for LDTN from Table 25-8 include the following:
• Carbon disulfide was the pollutant with the highest concentration according to NATA
and among annual averages. However, the annual average was an order of magnitude
higher than the modeled concentration.
• The pollutants with the highest cancer risks according to NATA were benzene,
carbon tetrachloride, and acetaldehyde. These same pollutants also had the highest
cancer risk approximations, although the ranking was different.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA and
based on the annual average was acrolein. However, the annual average-based
approximation (35.10) was an order of magnitude higher than the modeled
concentration (2.99).
Observations for MSTN from Table 25-8 include the following:
• The pollutants with the highest concentrations according to NATA were
acetaldehyde, formaldehyde, and benzene. The pollutants with the highest 2007
annual averages were also these three pollutants, although the order was different.
• The pollutants with the highest cancer risks according to NATA were benzene,
carbon tetrachloride, and acetaldehyde. These same pollutants also had the highest
cancer risk approximations, although the ranking was different.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA and
based on the annual average was acrolein. However, the annual average-based
approximation (37.39) was an order of magnitude higher than the modeled
concentration (2.39).
25.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 25-9 and 25-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 25-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 25-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
25-26
-------
Table 25-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Tennessee
to
v\
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Loudon, Tennessee (LDTN) - Loudon County
Benzene
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Dichloromethane
Naphthalene
Tetrachloroethylene
POM, Group 2
£>-Dichlorobenzene
Trichloroethylene
150.72
67.70
55.51
15.73
3.83
3.08
2.05
1.30
0.88
0.48
Benzene
1,3 -Butadiene
Hexavalent Chromium
Acetaldehyde
Arsenic, PM
Naphthalene
POM, Group 2
POM, Group 3
Nickel, PM
POM, Group 5
1.18E-03
4.72E-04
1.56E-04
1.49E-04
1.27E-04
1.05E-04
7.15E-05
3.40E-05
2.61E-05
2.30E-05
Carbon Tetrachloride
Benzene
Acetaldehyde
Acrylonitrile
1,3 -Butadiene
Tetrachloroethylene
£>-Dichlorobenzene
Formaldehyde
9.15
5.45
5.24
2.04
1.76
1.30
0.94
0.02
Loudon Middle School, Loudon, Tennessee (MSTN) - Loudon County
Benzene
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Dichloromethane
Naphthalene
Tetrachloroethylene
POM, Group 2
£>-Dichlorobenzene
Trichloroethylene
150.72
67.70
55.51
15.73
3.83
3.08
2.05
1.30
0.88
0.48
Benzene
1,3 -Butadiene
Hexavalent Chromium
Acetaldehyde
Arsenic, PM
Naphthalene
POM, Group 2
POM, Group 3
Nickel, PM
POM, Group 5
1.18E-03
4.72E-04
1.56E-04
1.49E-04
1.27E-04
1.05E-04
7.15E-05
3.40E-05
2.61E-05
2.30E-05
Carbon Tetrachloride
Benzene
Acetaldehyde
Acrylonitrile
1,3 -Butadiene
Chloromethylbenzene
1 ,2-Dichloroethane
/>-Dichlorobenzene
Tetrachloroethylene
Formaldehyde
8.58
6.12
2.98
1.87
1.63
1.35
1.11
0.59
0.45
0.02
-------
Table 25-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Tennessee
to
to
oo
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Loudon, Tennessee (LDTN) - Loudon County
Carbon Bisulfide
Toluene
Xylenes
Benzene
Hydrochloric acid
Styrene
Ethylbenzene
Acetaldehyde
Hexane
Formaldehyde
1,130.07
407.61
290.81
150.72
146.45
89.43
71.22
67.70
64.94
55.51
Acrolein
Manganese, PM
1,3 -Butadiene
Acetaldehyde
Hydrochloric acid
Formaldehyde
Benzene
Xylenes
Nickel, PM
Carbon Bisulfide
141,663.65
10,862.32
7,867.11
7,521.86
7,322.44
5,664.57
5,023.83
2,908.11
2,511.12
1,614.39
Acrolein
Formaldehyde
Acetaldehyde
Carbon Bisulfide
1,3 -Butadiene
Benzene
Carbon Tetrachloride
Acrylonitrile
Xylenes
Tetrachloroethylene
35.10
0.38
0.29
0.07
0.03
0.03
0.02
0.01
0.01
<0.01
Loudon Middle School, Loudon, Tennessee (MSTN) - Loudon County
Carbon Bisulfide
Toluene
Xylenes
Benzene
Hydrochloric acid
Styrene
Ethylbenzene
Acetaldehyde
Hexane
Formaldehyde
1,130.07
407.61
290.81
150.72
146.45
89.43
71.22
67.70
64.94
55.51
Acrolein
Manganese, PM
1,3 -Butadiene
Acetaldehyde
Hydrochloric acid
Formaldehyde
Benzene
Xylenes
Nickel, PM
Carbon Bisulfide
141,663.65
10,862.32
7,867.11
7,521.86
7,322.44
5,664.57
5,023.83
2,908.11
2,511.12
1,614.39
Acrolein
Formaldehyde
Acetaldehyde
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Acrylonitrile
Tetrachloroethylene
£>-Bichlorobenzene
1 ,2-Bichloroethane
37.49
0.30
0.17
0.03
0.03
0.01
0.01
0.01
0.01
O.01
-------
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risks based on each site's annual averages are limited to those pollutants for whicheach
respective site sampled. As discussed in Section 25.3, LDTN and MSTN sampled for VOC and
carbonyl compounds. In addition, the cancer and noncancer surrogate risk approximations are
limited to those sites sampling for a long enough period for annual averages to be calculated.
The Tennessee monitoring sites sampled year-round for each pollutant group mentioned above.
Observations from Table 25-9 include the following:
• Benzene, acetaldehyde, and formaldehyde were the highest emitted pollutants with
cancer UREs in Loudon County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) for Loudon County were benzene, 1,3-butadiene, and hexavalent
chromium.
• Five of the highest emitted pollutants in Loudon County also had the highest toxi city-
weighted emissions.
• For both monitoring sites, carbon tetrachloride, benzene, and acetaldehyde had the
highest cancer surrogate risk approximations. Carbon tetrachloride did not appear on
either emissions-based list, while benzene ranked highest on both.
Observations from Table 25-10 include the following:
• Carbon disulfide, toluene, and xylenes were the highest emitted pollutants with
noncancer RfCs in Loudon County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) for Loudon County were acrolein, manganese, and 1,3-butadiene.
• Six of the highest emitted pollutants also had the highest toxicity-weighted emissions
for Loudon County.
• The pollutant with the highest noncancer risk approximation was acrolein for both
sites. Acrolein was also the pollutant with the highest toxicity-weighted emissions,
yet this pollutant's emissions ranked 20th.
25-29
-------
• Carbon disulfide, the pollutant with the highest daily, seasonal, and annual average
concentrations, appeared on all three lists for LDTN.
25.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Tennessee monitoring site were
acetaldehyde, acrolein, benzene, 1,3-butadiene, carbon tetrachloride, and
formaldehyde.
»«» Formaldehyde had the highest daily average concentration for MSTN, while carbon
disulfide had the highest daily average concentration for LDTN.
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmark for
both sites.
25-30
-------
26.0 Sites in Texas
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS sites in Texas, and integrates these concentrations with
emissions, meteorological, and risk information.
26.1 Site Characterization
This section characterizes the monitoring sites by providing geographical and physical
information about the location of the sites and the surrounding areas. The CAMS 35 monitoring
site is located in the Houston-Galveston-Brazoria, TX CMSA. The CAMS 85 monitoring site is
located in the Longview-Marshall, TX MSA. Figures 26-1 and 26-2 are composite satellite
images retrieved from Google™ Maps showing the monitoring sites in their urban and rural
locations. Figures 26-3 and 26-4 identify point source emission locations within 10 miles of
each site as reported in the 2002 NEI for point sources. Table 26-1 describes the area
surrounding each monitoring site and provides supplemental geographical information such as
land use, location setting, and locational coordinates.
The CAMS 35 monitoring site is located in Deer Park, southeast of Houston, in east
Texas. The site is located at Brown Memorial Park, in a primarily residential area, as shown in
Figure 26-1. Major thoroughfares surround the site, including Red Bluff Road and Beltway 8.
The Houston Ship Channel is located to the north and Galveston Bay is located to the east and
southeast. The east side of Houston has significant industry, including several oil refineries. As
Figure 26-3 shows, no point source emission sources are located within one mile of the CAMS
35 monitoring site. However, a large number of emission sources is located roughly along a line
that runs east to west just north of the site. A second cluster of emission sources is located to the
southeast of the monitoring site. The most numerous source categories surrounding CAMS 35
are involved in the oil and gas sector, specifically the production of organic chemicals, liquids
distribution, and the production of chemicals and allied products.
CAMS 85 is located in Karnack, Texas, about 10 miles northeast of Marshall, and about
six miles west of the Texas-Louisiana border. The site is located on the property of the
26-1
-------
to
ON
to
(CAMS 35) Monitoring Site
: i r ^F* : ^~
l iMM'fc ii i -.- »-*=-'—^
-------
Figure 26-2. Karnack, Texas (CAMS 85) Monitoring Site
to
OJ
©2008 Google/ONAVTECH
Scale: 3cm = 200m
-------
Figure 26-3. NEI Point Sources Located Within 10 Miles of CAMS 35
l(ot« DIM totidll) dtfiMy oxj nMeaeon m» mil Uetuwt
cfisplaye-d may not refire-s*nl al Incilnies AiBwn th« af«B of merest
Legend
•fr CAMS 35 NATTS site
10 mite radius | County boundary
Source Category Group (No. of Facilities)
' Agricultural Chemicals Production Industrial facility (1 }
C Cherr»cal$ & Allied Products facility (26)
z Electrical & Electrons Equipment Facility (1)
0 Fabricated Metal Products Facility (3)
F Fuel Combustfon Industrial Facility (27)
i Incineration Industrial f aeilrty (2)
J industrial Machinery & Equipment facility (1 )
L Liquids Distribution Industrial Facility (30)
B Mineral Products Processing Industrial Facility {3}
x Miscellaneous Manufacturing Industries (1)
p Miscellaneous Processes Industrial Facility (4)
- Motor FreigM Transportation & V^rehousing (1)
P PetroleunVWat Gas Prod & Refining Industrial Facility (8)
3 Pipelines. Except Natural Gas (1)
v Polymers & RSSWYB Prodi*^ion Industrial Facility (6)
» Production of Itwganlc Chemicals Industrial facility (1)
4 Production of Organic Chemicals Industrial Facility (43)
:: Pulp 8, Paper Production Facility (1)
f Rubber & Miscellaneous Plaslrc Products Facility (2)
U Ston*. C&ay, Glass, £ Concrete Products (1)
S Surface Coating Processes Industrial facility (8)
+ Transportation by Air (1)
a Utility Boilers {9)
• Waste Treatment & Disposal Industrial facility (2)
' Wholesale Trade (3)
26-4
-------
Figure 26-4. NEI Point Sources Located Within 10 Miles of CAMS 85
..
-,
t**wn-w
(lot* DIM tottcJI!) dwiwij WMJ ctfotatMn m»
-------
Table 26-1. Geographical Information for the Texas Monitoring Sites
Site Code
CAMS 35
CAMS 85
AQS Code
48-201-1039
48-203-0002
Location
Deer Park
Karnack
County
Harris
Harrison
Micro- or
Metropolitan
Statistical Area
T-TrtiiQtrtTi-
-L 1\J Llo IAJ11
Galveston-
Brazoria, TX
CMSA
Longview-
Marshall, TX
MSA
lV.LO.ii.
Latitude
and
Longitude
29.670046,
-95.128485
32.669003,
-94.167449
Land Use
Residential
Agricultural
Location
Setting
Suburban
Rural
Description of the
Immediate Surroundings
CAMS 35 is located southeast of Houston, Texas,
in Deer Park, near the intersection of Lambuth and
Durant St. The site is a shelter on the northwest
periphery of Brown Memorial Park. Residential
housing surrounds the site to the northeast, east,
and south. A medical center lies to the southwest
and a stand of trees lies to the northwest.
Monitoring at this location began in 1996 and
additional parameters being monitored for include
criteria pollutants, organic and elemental carbon,
and meteorological parameters.
CAMS 85 is located in the rural town of Karnack,
Texas, less than 300 meters from the intersection of
Highway 134 and Spur Road 449. The site is
located on the property of the Longhorn Army
Ammunition Plant. Trees surround the site to the
north, with open field to the east and south. The
town of Karnack is located to the west of the
monitoring site. NO, NO2, NOX, O3, PM10 and
PM2 5 are monitored for in addition to VOC and
meteorological parameters.
to
Oi
BOLD = EPA-designated NATTS Site
-------
Longhorn Army Ammunition Plant near the intersection of Highway 134 and Spur Road 449, as
shown in Figure 26-2. The surrounding area is rural and agricultural. As Figure 26-4 shows,
two point source emission sources are located within 10 miles of the CAMS 85 monitoring site.
Both sources are on the outer periphery of the 10-mile radius. One is involved in processes
utilizing fuel combustion and the other is involved in the production and refining of petroleum
and natural gas.
Table 26-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Texas
monitoring sites. County-level vehicle registration and population data for Harris and Harrison
Counties were obtained from the Texas Department of Transportation and the U.S. Census
Bureau. Table 26-2 also includes a vehicle registration to county population ratio (vehicles per
person). An estimate of 10-mile vehicle registration was calculated by applying the county-level
vehicle registration to population ratio to the 10-mile population surrounding the monitoring site.
Table 26-2 also contains annual average daily traffic information, as well as the year of the
traffic data estimate and the source from which it was obtained. Finally, Table 26-2 presents the
daily VMT for each urban area.
Table 26-2. Population, Motor Vehicle, and Traffic Information for the Texas Monitoring
Sites
Site
CAMS 35
CAMS 85
2007
Estimated
County
Population
3,935,855
63,504
Number
of
Vehicles
Registered
3,192,222
67,719
Vehicles
per Person
(Registration:
Population)
0.81
1.07
Population
Within
10 Miles
667,537
3,032
Estimated
10-mile
Vehicle
Ownership
541,414
3,233
Annual
Average
Traffic
Data1
31,130
2,380
VMT
(thousands)
97,774
1,688
1 Daily Average Traffic Data reflects 2001 data from the Texas DOT (CAMS 35) and 2002 data from the Texas DOT
(CAMS 85)
BOLD = EPA-designated NATTS Site
Observations from Table 26-2 include the following:
• The county-level and 10-mile population and vehicle ownership is significantly
higher in Harris County than Harrison County.
• Compared to other counties with monitoring sites, Harris County ranked third highest
for population and fourth highest for vehicle ownership. The county-level population
26-7
-------
and vehicle ownership for Harrison County was on the low end compared to other
program sites.
• The CAMS 35 10-mile population does not reflect the magnitude of the county
population, indicating that the site is not located near the center of highest population
density. This is also true for CAMS 85. The 10-mile population ranked 23rd for
CAMS 35 and 48th (the lowest estimated) for CAMS 85, compared to other program
sites.
• The vehicle per person ratio for CAMS 85 is higher than CAMS 35 and ranked ninth
highest among NATTS and UATMP sites.
• The traffic volume passing CAMS 35 is higher than the volume passing CAMS 85,
but was in the middle of the range compared to other program sites. The traffic
volume for CAMS 85 is the fourth lowest among all sites.
• The VMT for the Houston area ranked eight highest, while the VMT for the
Longview area was the lowest among urban areas with monitoring sites.
26.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
sites in Texas on sampling days, as well as over the course of the year.
26.2.1 Climate Summary
The eastern third of Texas is characterized by a subtropical humid climate, with the
climate becoming more continental in nature further north and west. The proximity to the Gulf
of Mexico acts as a moderating influence as temperatures soar in the summer or dip in the
winter. Areas closer to the coast, such as Houston, remain slightly cooler than neighboring areas
to the north. The reverse is also true, as coastal areas are warmer in the winter than areas further
inland, although East Texas winters are relatively mild. The onshore flow from the Gulf of
Mexico also allows humidity levels to remain higher near the coast. The winds flow out of the
Gulf of Mexico a majority of the year, with the winter months being the exception, as frontal
systems allow colder air from the north to filter in. Abundant rainfall is also typical of the
region, again due in part to the nearness to the Gulf of Mexico (Ruffner and Bair, 1987 and
TAMU, 2007).
26-8
-------
26.2.2 Meteorological Conditions in 2007
Hourly meteorological data at weather stations near these sites were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The two closest
NWS weather stations are located at William P. Hobby Airport (near CAMS 35) and Shreveport
Regional Airport (near CAMS 85), WBAN 12918 and 13957, respectively.
Table 26-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 26-3 is the 95 percent
confidence interval for each parameter. As shown in Table 26-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
26.2.3 Composite Back Trajectories for Sampling Days
Figures 26-5 and 26-6 are composite back trajectory maps for the Texas monitoring sites
for the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the sites in Figures 26-5 and 26-6 represents 100 miles.
Observations from Figure 26-5 for CAMS 35 include the following:
• Back trajectories originated from a variety of directions at the CAMS 35 monitoring
site, although most trajectories originated from the southeast.
• The 24-hour air shed domain for CAMS 35 was somewhat smaller in size than other
monitoring sites. The furthest away a trajectory originated was the Gulf of Mexico,
less than 600 miles away. However, most trajectories originated within 400 miles of
the site.
26-9
-------
Table 26-3. Average Meteorological Conditions near the Texas Monitoring Sites
Site
CAMS 35
CAMS 85
Closest NWS
Station and
WBAN
William P.
Hobby
Airport
12918
Shreveport
Regional
Airport
13957
Average
Type
Sampling
Day
All 2007
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
79.65
±2.93
78.74
±1.27
77.88
±3.62
77.31
±1.54
Average
Temperature
(op)
71.70
±2.87
70.42
± 1.27
68.61
±3.38
67.05
±1.49
Average
Dew Point
Temperature
(°F)
61.75
±3.19
60.22
±1.47
55.77
±3.62
54.10
±1.63
Average
Wet Bulb
Temperature
(°F)
65.72
±2.78
64.43
±1.25
61.21
±3.15
59.75
±1.40
Average
Relative
Humidity
(%)
73.64
±2.82
72.67
± 1.15
66.23
±2.63
66.05
±1.13
Average
Sea Level
Pressure
(mb)
1017.06
±1.22
1017.45
±0.51
1017.06
± 1.27
1017.32
±0.53
Average
Scalar Wind
Speed
(kt)
5.92
±0.69
5.94
±0.28
5.58
±0.64
5.52
±0.26
BOLD = EPA-designated NATTS Site
to
o
-------
Figure 26-5. Composite Back Trajectory Map for CAMS 35
to
ON
9ft 100 150 200 I
i.;--.
-------
Figure 26-6. Composite Back Trajectory Map for CAMS 85
to
ON
^^
to
0 W 100 300 300 400
MM
-------
Observations from Figure 26-6 for CAMS 85 include the following:
• Back trajectories originated from a variety of directions at the CAMS 85 monitoring
site, although most trajectories originated from the southeast and south.
• The 24-hour air shed domain for CAMS 85 was larger in size than CAMS 35 and
many other monitoring sites. The furthest away a trajectory originated was western
South Dakota, 900 miles away. However, this particular back trajectory originated
nearly 400 miles further than most, as most trajectories originated within 500 miles of
the site.
26.2.4 Wind Roses for Sampling Days
Hourly wind data from the weather stations at William Hobby (for CAMS 35) and
Shreveport Regional Airports (for CAMS 85) near the monitoring sites were uploaded into a
wind rose software program, WRPLOT (Lakes, 2006) to produce customized wind roses. A
wind rose shows the frequency of wind directions on a 16-point compass, and uses different
shading to represent wind speeds. Figures 26-7 and 26-8 are the wind roses for the Texas
monitoring sites on days that samples were collected.
Figure 26-7. Wind Rose for CAMS 35 Sampling Days
•WES r
26-13
-------
Figure 26-8. Wind Rose for CAMS 85 Sampling Days
SOUTH---
WIND SPEED
(Knots)
O 5=22
^| 17 - 21
^| 11 - 17
^| 7- 11
CH 1-7
Calms: 18.19%
Observations from Figures 26-7 and 26-8 include the following:
• The wind roses for CAMS 35 and CAMS 85 are very similar.
• Southeasterly and southerly winds prevailed near both sites. Northerly winds were
also observed somewhat frequently near the sites.
• Calm winds were observed for 18 percent of the wind measurements near both sites.
• The strongest wind speeds were measured with westerly and northwesterly winds.
26.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Texas
monitoring sites were identified using the EPA risk screening process described in Section 3.2.
In brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
26-14
-------
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 26-4 presents the pollutants that failed at least one screen for each Texas monitoring site
and highlights each site's pollutants of interest (shaded). The CAMS 35 and CAMS 85
monitoring sites sampled VOC only.
Table 26-4. Comparison of Measured Concentrations and EPA Screening Values for the
Texas Monitoring Sites
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Deer Park, Texas - CAMS 35
Acrolein
Carbon Tetrachloride
Benzene
1,3 -Butadiene
£>-Dichlorobenzene
Tetrachloroethylene
1 ,2-Dichloroethane
Acrylonitrile
Vinyl chloride
Methyl fer/-Butyl Ether
1 , 1 ,2-Trichloroethane
Dichloromethane
Total
57
57
57
55
26
26
17
10
9
2
1
1
318
57
57
57
57
52
54
17
10
39
39
5
57
501
100.00
100.00
100.00
96.49
50.00
48.15
100.00
100.00
23.08
5.13
20.00
1.75
63.47
17.92
17.92
17.92
17.30
8.18
8.18
5.35
3.14
2.83
0.63
0.31
0.31
17.92
35.85
53.77
71.07
79.25
87.42
92.77
95.91
98.74
99.37
99.69
100.00
Karnack, Texas - CAMS 85
Carbon Tetrachloride
Benzene
Acrolein
1,3 -Butadiene
Tetrachloroethylene
£>-Dichlorobenzene
Vinyl chloride
1 ,2-Dichloroethane
Acrylonitrile
Total
52
52
50
10
2
1
1
1
1
170
52
52
50
36
30
16
5
1
1
243
100.00
100.00
100.00
27.78
6.67
6.25
20.00
100.00
100.00
69.96
30.59
30.59
29.41
5.88
1.18
0.59
0.59
0.59
0.59
30.59
61.18
90.59
96.47
97.65
98.24
98.82
99.41
100.00
26-15
-------
Observations from Table 26-4 include the following:
• Twelve pollutants with a total of 318 measured concentrations failed at least one
screen for CAMS 35, while nine pollutants with a total of 170 measured
concentrations failed screens for CAMS 85.
• The pollutants of interest varied by site, yet the following four pollutants of interest
were common to both sites: acrolein, benzene, 1,3-butadiene, carbon tetrachloride.
• Of the four common pollutants of interest, 100 percent of the measured detections of
acrolein, benzene, and carbon tetrachloride failed screens for both sites.
• Of the pollutants with at least one failed screen, approximately 63 percent of
measurements failed screens for CAMS 35, while nearly 70 percent failed screens for
CAMS 85. Thus, the failure rate appears higher for CAMS 85. However, many of
the pollutants that failed screens were detected more frequently at CAMS 35, leading
to a much larger number of measured detections.
26.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Texas monitoring sites. The averages presented are provided for the pollutants of interest
for each site. Complete site-specific statistical summaries are provided in Appendices J through
O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the sites, where applicable.
26.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and when the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 26-5, where applicable.
26-16
-------
Table 26-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Texas Monitoring Sites
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Hg/m3)
Winter
Average
(Hg/m3)
Spring
Average
(jig/m3)
Summer
Average
(Hg/m3)
Autumn
Average
(Hg/m3)
Annual
Average1
(jig/m3)
Deer Park, Texas - CAMS 35
Acrolein
Acrylonitrile
Benzene
1,3 -Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
1,2-Dichloroethane
Tetrachloroethylene
57
10
57
57
57
52
17
54
57
57
57
57
57
57
57
57
0.54
±0.08
0.55
±0.29
1.59
±0.32
0.43
±0.34
0.68
±0.04
0.13
±0.03
1.13
±0.67
0.26
±0.06
0.52
±0.20
NR
1.29
±0.18
0.26
±0.09
0.66
±0.08
0.08
±0.03
NR
0.23
±0.14
0.44
±0.08
NR
1.06
±0.38
0.22
±0.09
0.69
±0.07
0.09
±0.03
NR
0.17
±0.06
0.61
±0.22
NR
1.42
±0.46
0.19
±0.08
0.68
±0.08
0.13
±0.06
NR
0.26
±0.15
0.59
±0.10
NR
2.57
±0.87
0.99
±1.24
0.69
±0.04
0.18
±0.06
NR
0.33
±0.12
0.54
±0.08
0.12
±0.07
1.59
±0.32
0.43
±0.34
0.68
±0.04
0.12
±0.03
0.37
±0.24
0.25
±0.06
Karnack, Texas - CAMS 85
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
50
52
36
52
52
52
52
52
0.43
±0.07
1.15
±0.15
0.04
±0.02
0.68
±0.04
0.35
±0.15
1.02
±0.20
0.04
±0.02
0.65
±0.07
0.38
±0.09
0.94
±0.27
0.02
±0.01
0.72
±0.07
0.42
±0.13
1.38
±0.22
0.04
±0.05
0.68
±0.06
0.51
±0.16
1.30
±0.44
NR
0.65
±0.10
0.41
±0.07
1.15
±0.15
0.03
±0.01
0.68
±0.04
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations from Table 26-5 include the following:
• The pollutant with the highest daily average concentration by mass was benzene for
both sites (1.59 ± 0.32 |ig/m3 for CAMS 35 and 1.15 ± 0.15 |ig/m3 for CAMS 85).
• As shown in Table 4-11, of the program-level pollutants of interest, CAMS 35 had
the highest daily average concentration of 1,3-butadiene; third highest daily average
concentration of acrylonitrile; and fourth highest daily average concentration of
benzene. In addition, CAMS 85 had the fifth highest daily average concentration of
acrylonitrile.
26-17
-------
• Concentrations of benzene were lowest during the winter and highest during the fall
at CAMS 35. Although 1,3-butadiene was highest in the autumn, the very large
confidence interval indicates that this average was affected by outliers.
• The concentrations of the pollutants of interest did not vary significantly from season
to season at CAMS 85.
• Seasonal averages could not be calculated for acrylonitrile and 1,2-dichloroethane for
CAMS 35 due to the low number of detections in each season. An autumn average
for 1,3-butadiene could not be calculated for CAMS 85 for the same reason.
26.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one ore more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. The two Texas monitoring sites have not sampled continuously for
five years as part of the National Monitoring Program; therefore, the trends analysis was not
conducted.
26.5 Pearson Correlations
Table 26-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations from Table 26-6 include the following:
• All of the correlations for CAMS 85 were weak, with one exception. Benzene
exhibited a strong negative correlation with the wind speed, indicating that
concentrations of this pollutant increase with decreasing wind speed.
• The correlations for CAMS 35 were also weak, with two exceptions. Acrylonitrile
exhibited a strong negative correlation with relative humidity, indicating that
concentrations of this pollutant increase with decreasing moisture content. However,
this correlation was based on 10 measured detections; thus, the correlations may be
skewed. />-Dichlorobenzene also exhibited a strong negative correlation with the
wind speed, indicating that concentrations of this pollutant increase with decreasing
wind speed.
26-18
-------
Table 26-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Texas
Monitoring Sites
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Deer Park, Texas - CAMS 35
Acrolein
Acrylonitrile
Benzene
1,3 -Butadiene
Carbon Tetrachloride
/>-Dichlorobenzene
1 ,2-Dichloroethane
Tetrachloroethylene
57
10
57
57
57
52
17
54
0.25
0.02
0.23
-0.04
0.23
0.28
0.39
0.05
0.25
-0.13
0.14
-0.09
0.17
0.18
0.38
0.00
0.20
-0.43
0.08
-0.14
0.08
0.05
0.42
-0.01
0.23
-0.33
0.10
-0.12
0.12
0.10
0.41
-0.01
-0.05
-0.66
-0.14
-0.17
-0.20
-0.28
0.07
-0.04
-0.13
0.26
0.11
0.27
-0.17
-0.05
-0.05
0.19
-0.12
0.05
-0.35
-0.02
0.05
-0.57
-0.07
-0.30
Karnack, Texas - CAMS 85
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
50
52
36
52
0.09
0.16
0.10
0.07
0.09
0.08
0.08
0.07
0.06
0.04
0.03
0.01
0.07
0.05
0.05
0.05
-0.10
-0.11
-0.11
-0.11
-0.06
-0.01
-0.03
-0.11
0.09
-0.54
-0.05
0.05
to
-------
26.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at each
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
26.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Texas
monitoring sites to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 26-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 26-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• For both sites, all of the seasonal averages of acrolein exceeded the intermediate
MRL.
• Acrolein has no chronic MRL. Therefore, chronic risk could not be evaluated.
26.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Texas monitoring sites and where
the annual average concentrations could be calculated, risk was further examined by reviewing
cancer and noncancer risk estimates from NATA and calculating cancer and noncancer surrogate
risk approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
26-20
-------
Table 26-7. MRL Risk Screening Assessment Summary for the Texas Monitoring Sites
Site
CAMS 35
CAMS 85
Method
TO-15
TO-15
Pollutant
Acrolein
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
7.00
#of
Exceedances/
#of
Measured
Detections
0/57
0/50
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
0.09
Winter
Average
(Ug/m3)
0.52
±0.20
0.35
±0.15
Spring
Average
(Ug/m3)
0.44
±0.08
0.38
±0.09
Summer
Average
(Ug/m3)
0.61
±0.22
0.42
±0.13
Autumn
Average
(Ug/m3)
0.59
±0.10
0.51
±0.16
ATSDR
Chronic
MRL
(Ug/m3)
—
-
Annual
Average1
(Ug/m3)
0.54
±0.08
0.41
±0.07
BOLD = EPA-designated NATTS Site
BOLD = exceedance of the intermediate or chronic MRL
- = an MRL risk factor is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
ON
to
-------
noncancer surrogate risk approximations are presented in Table 26-8. The data from NATA are
presented for the census tract where each monitoring site is located. The pollutants of interest
for each site are bolded.
The census tract information for the Texas monitoring sites is as follows:
• The census tract for CAMS 35 is 48201342300, which had a population of 6,240 and
represented 0.18 percent of the Harris County population in 2000.
• The census tract for CAMS 85 is 48203020102, which had a population of 5,492 and
represented approximately nine percent of the Harrison County population in 2000.
Observations for CAMS 35 from Table 26-8 include the following:
• Benzene was the pollutant with the highest concentration according to NATA and
among annual averages. The modeled concentration and the annual average for
benzene were very similar.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,2-
dichloroethane, and acrylonitrile. By contrast, 1,3-butadiene, benzene, and carbon
tetrachloride had the highest cancer risk approximations.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA and
based on annual averages was acrolein.
Observations for CAMS 85 from Table 26-8 include the following:
• Similar to CAMS 35, benzene was the pollutant with the highest concentration
according to NATA and among annual averages, although the modeled concentration
was lower than the annual average concentration.
• The pollutants with the highest cancer risks according to NATA were benzene and
carbon tetrachloride. Carbon tetrachloride and benzene also had the highest cancer
risk approximations.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA and
based on the annual average was acrolein. However, the annual average-based
approximation (20.56) was an order of magnitude higher than the modeled
concentration (1.58).
26-22
-------
Table 26-8. Cancer and Noncancer Risk Summary for the Monitoring Sites in Texas
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk (HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Deer Park, Texas (CAMS 35) - Census Tract ID 48201342300
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
p-Dichlorobenzene
1,2-Dichloroethane
Dichloromethane
Methyl fer/-Butyl Ether
Tetrachloroethylene
1,1,2-Trichloroethane
Vinyl chloride
—
0.000068
0.000007
0.00003
0.000015
0.000011
0.000026
0.00000047
—
0.000005
0.000016
0.000008
0.00002
0.002
0.03
0.002
0.04
0.8
2.4
1
3
0.27
0.4
0.1
0.21
0.08
1.57
0.14
0.23
0.04
0.19
0.47
1.36
0.18
0.01
0.16
—
5.23
12.23
4.29
3.50
0.49
5.04
0.23
—
1.10
0.02
1.41
10.59
0.03
0.05
0.07
0.01
O.01
O.01
O.01
0.01
0.01
0.01
0.01
0.54 ±0.08
0.12 ±0.07
1.59 ±0.32
0.43 ±0.34
0.68 ±0.04
0.12 ±0.03
0.37 ±0.24
0.51 ±0.11
0.59 ±0.36
0.25 ±0.06
0.05 ±0.01
0.06 ± 0.02
—
7.97
11.15
12.76
10.24
1.34
9.55
0.24
—
1.24
0.76
0.51
26.93
0.06
0.05
0.21
0.02
O.01
O.01
O.01
0.01
0.01
0.01
0.01
Karnack, Texas (CAMS 85) - Census Tract ID 48203020102
Acrolein
Acrylonitrile
Benzene
1,3-Butadiene
Carbon Tetrachloride
£>-Dichlorobenzene
1,2-Dichloroethane
Tetrachloroethylene
Vinyl chloride
~
0.000068
0.000007
0.00003
0.000015
0.000011
0.000026
0.000005
0.000008
0.00002
0.002
0.03
0.002
0.04
0.8
2.4
0.27
0.1
0.03
O.01
0.52
0.01
0.21
0.01
0.01
0.01
O.01
~
0.01
4.11
0.38
3.12
0.05
0.27
0.06
0.01
1.58
O.01
0.01
0.01
0.01
0.01
0.01
O.01
O.01
0.41 ±0.07
0.03 ±0.01
1.15±0.15
0.03 ±0.01
0.68 ±0.04
0.04 ±0.01
0.05 ±0.01
0.08 ±0.05
0.04 ±0.01
~
2.14
8.06
0.96
10.16
0.46
1.24
0.41
0.29
20.56
0.02
0.04
0.02
0.02
0.01
0.01
O.01
O.01
to
ON
to
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
26.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 26-9 and 26-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 26-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 26-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risks based on each site's annual averages are limited to those pollutants for which
each respective site sampled. As discussed in Section 26.3, the Texas monitoring sites sampled
for VOC only. In addition, the cancer and noncancer surrogate risk approximations are limited
to those sites sampling for a long enough period for annual averages to be calculated. The Texas
monitoring sites sampled year-round for the pollutant group mentioned above.
Observations from Table 26-9 include the following:
• Benzene and formaldehyde were the highest emitted pollutants with cancer UREs in
both Harris and Harrison Counties, although the quantity of the emissions was much
lower in Harrison County (CAMS 85).
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
cancer UREs) for Harris County (CAMS 35) were benzene, 1,3-butadiene, and
hexavalent chromium. The pollutants with the highest toxicity-weighted emissions
(of the pollutants with cancer UREs) for Harrison County (CAMS 85) were
hexavalent chromium, ethylene oxide, and benzene.
• Four of the highest emitted pollutants in Harris County (CAMS35) also had the
highest toxicity-weighted emissions, while five of the highest emitted pollutants in
Harrison County (CAMS 85) also had the highest toxicity-weighted emissions.
26-24
-------
Table 26-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Sites in Texas
to
ON
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Deer Park, Texas (CAMS 35) - Harris County
Benzene
Formaldehyde
1,3 -Butadiene
Dichloromethane
Acetaldehyde
Tetrachloroethylene
1 ,3 -Dichloropropene
Naphthalene
Trichloroethylene
£>-Dichlorobenzene
2,217.79
1,309.32
504.56
491.73
463.35
436.54
284.92
104.39
90.55
88.48
Benzene
1,3 -Butadiene
Hexavalent Chromium
Naphthalene
Arsenic, PM
Tetrachloroethylene
Ethylene oxide
1 ,2-Dichloroethane
Cadmium, PM
Acrylonitrile
1.73E-02
1.51E-02
6.67E-03
3.55E-03
3.23E-03
2.58E-03
2.53E-03
.94E-03
.53E-03
.36E-03
1,3 -Butadiene
Benzene
Carbon Tetrachloride
1 ,2-Dichloroethane
Acrylonitrile
£>-Dichlorobenzene
Tetrachloroethylene
1 , 1 ,2-Trichloroethane
Vinyl chloride
Dichloromethane
12.76
11.15
10.24
9.55
7.96
1.34
1.24
0.77
0.51
0.24
Karnack, Texas (CAMS 85) - Harrison County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Ethylene oxide
Dichloromethane
Naphthalene
Tetrachloroethylene
1 ,3 -Dichloropropene
Trichloroethylene
150.03
55.20
46.57
21.65
13.97
11.20
10.71
5.74
5.50
2.20
Hexavalent Chromium
Ethylene oxide
Benzene
1,3 -Butadiene
Arsenic, PM
Naphthalene
Cadmium, PM
Acetaldehyde
Beryllium, PM
Chloromethylbenzene
.24E-03
.23E-03
.17E-03
6.49E-04
3.73E-04
3.64E-04
2.02E-04
1.02E-04
9.61E-05
6.43E-05
Carbon Tetrachloride
Benzene
Acrylonitrile
1 ,2-Dichloroethane
1,3 -Butadiene
£>-Dichlorobenzene
Tetrachloroethylene
Vinyl chloride
10.16
8.06
2.12
1.25
0.96
0.46
0.41
0.29
-------
Table 26-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Sites in Texas
to
Oi
to
Oi
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Deer Park, Texas (CAMS 35) - Harris County
Toluene
Methyl tert-butyl ether
Xylenes
Hexane
Benzene
Methanol
Hydrochloric acid
Formaldehyde
Ethylbenzene
1,1,1 -Trichloroethane
5,444.57
5,164.71
3,632.56
2,627.18
2,217.79
2,024.57
1,422.38
1,309.32
879.63
815.29
Acrolein
Chlorine
1,3 -Butadiene
Formaldehyde
Nickel, PM
Manganese, PM
Benzene
Hydrochloric acid
Hexamethylene- 1 ,6-
diisocyanate, gas
Acrylic acid
2,687,004.98
1,460,835.50
252,280.21
133,604.32
97,233.43
83,395.60
73,926.48
71,119.04
62,650.00
53,518.71
Acrolein
1,3 -Butadiene
Acrylonitrile
Benzene
Carbon Tetrachloride
Tetrachloroethylene
Vinyl chloride
Dichloromethane
Methyl tert-Butyl Ether
1 ,2-Dichloroethane
26.93
0.21
0.06
0.05
0.02
<0.01
0.01
O.01
O.01
0.01
Karnack, Texas (CAMS 85) - Harrison County
Toluene
Xylenes
Ethylene glycol
Benzene
Hydrofluoric acid
Methanol
Ethylbenzene
Chloromethane
Hexane
Formaldehyde
286.81
268.44
162.87
150.03
71.42
68.04
67.26
62.37
59.30
55.20
Acrolein
Chlorine
Manganese, PM
Hexamethylene- 1 ,6-
diisocyanate, gas
Mercury, PM
1,3 -Butadiene
Formaldehyde
Cadmium, PM
Acetaldehyde
Benzene
200,031.63
86,241.00
17,645.94
12,040.00
11,359.43
10,824.10
5,632.65
5,616.04
5,174.06
5,000.83
Acrolein
Benzene
Carbon Tetrachloride
1,3 -Butadiene
Acrylonitrile
Vinyl chloride
Tetrachloroethylene
£>-Dichlorobenzene
1 ,2-Dichloroethane
20.55
0.04
0.02
0.02
0.02
O.01
O.01
O.01
O.01
-------
• For CAMS 35, 1,3-butadiene, benzene, and carbon tetrachloride had the highest
cancer surrogate risk approximations. Benzene and 1,3-butadiene appear on both
emissions-based lists, while carbon tetrachloride did not appear on either emissions-
based list.
• For CAMS 85, carbon tetrachloride, benzene, and acrylonitrile had the highest cancer
surrogate risk approximations. Carbon tetrachloride and acrylonitrile did not appear
on either emissions-based list, although benzene did.
Observations from Table 26-10 include the following:
• Toluene was the highest emitted pollutant with a noncancer RfC in both counties,
although it did not appear on the lists of highest toxicity weighted emissions or
noncancer risk approximations.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) for both counties were acrolein and chlorine.
• Three of the highest emitted pollutants also had the highest toxicity-weighted
emissions for Harris County (CAMS 35), while two of the highest emitted pollutants
also had the highest toxicity-weighted emissions for Harrison County (CAMS 85).
• The pollutant with the highest noncancer risk approximation was acrolein for both
sites. Acrolein was also the pollutant with the highest toxicity-weighted emissions
for both counties, yet this pollutant's emissions ranked 33rd in Harris County
(CAMS 35) and 29th in Harrison County (CAMS 85).
26.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest common to each Texas monitoring site were acrolein,
benzene, 1,3-butadiene, and carbon tetrachloride.
»«» Benzene had the highest daily average concentration for both of the sites.
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmark for
both sites.
26-27
-------
27.0 Site in Utah
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Utah, and integrates these concentrations with
emissions, meteorological, and risk information.
27.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Utah site is located in
the Ogden-Clearfield, UT MSA. Figure 27-1 is a composite satellite image retrieved from
Google™ Maps showing the monitoring site in its urban location. Figure 27-2 identifies point
source emission locations within 10 miles of the site as reported in the 2002 NEI for point
sources. Table 27-1 describes the area surrounding the monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
BTUT is located in Bountiful, in northern Utah. Bountiful is north of Salt Lake City, and
is situated in a valley between the Great Salt Lake to the west and the Wasatch Mountains to the
east. Figure 27-1 shows that BTUT is located on the property of Viewmont High School, in a
primarily residential area. The site is located about a quarter of a mile from 1-15, which runs
north-south through most of the surrounding urban area including Salt Lake City, Clearfield, and
Ogden. Figure 27-2 shows that most of the emission sources near the Bountiful site are located
to the south of the site. A number of these emission sources are involved in processes utilizing
fuel combustion, petroleum and natural gas production and refining, and fabricated metal
production.
Table 27-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the Utah
monitoring site. County-level vehicle registration and population data for Davis County, Utah
were obtained from the Utah Tax Commission and the U.S. Census Bureau. Table 27-2 also
includes a vehicle registration to county population ratio (vehicles per person). In addition, the
27-1
-------
Figure 27-1. Bountiful, Utah (BTUT) Monitoring Site
to
^1
to
©2008 Google/ONAVTECH
Scale: 3cm = 100m
-------
Figure 27-2. NEI Point Sources Located Within 10 Miles of BTUT
=
Nor* Du* la t»cUl» dwiM, «KJ s«ww*wn fh*
P«tT04*umlW3t Gas Prod S, Rthntng Industrial Facility (5)
Pnntirhg 5 Putthshmg Facility (1)
Stone Clay. Glass. K Concrete Products (21
Surface Coaling Prac«5.ses Industrial Facility (2)
Transportation by Air (1)
Utility Boilers (1)
Want Treatment & D»po**Mndus*ial Facility (2)
27-3
-------
Table 27-1. Geographical Information for the Utah Monitoring Site
Site
Code
BTUT
AQS Code
49-011-0004
Location
Bountiful
County
Davis
Micro- or
Metropolitan
Statistical Area
Ogden-Clearfield,
UT
Latitude
and
Longitude
40.902967,
-111.884467
Land Use
Residential
Location
Setting
Suburban
Description of the
Immediate Surroundings
The Bountiful Viewmont site is located in a suburban
area of the Ogden-Clearfield MSA, at 171 West 1370
North in Bountiful, Utah. This site is a relocation of
the BOUT site, which was about 1.1 miles south of
the new site. The site is located on the grounds of
Viewmont High School, adjacent to a parking lot,
tennis courts, and a football field. The surrounding
neighborhood is made up of residential properties.
BTUT is a SLAMS neighborhood-scale site for
monitoring population exposure to SO2, CO, NO2,
and PM2 5; and a NAMS neighborhood-scale site for
monitoring maximum ozone concentrations.
Speciated PM2 5 sampling, meteorological
monitoring, and NATTS air toxics sampling are also
done at the Bountiful Viewmont site. Several
petroleum refineries are located two to five miles
away from the site, as are several sand and gravel
mining operations.
to
-k
BOLD = EPA-designated NATTS Site
-------
Table 27-2. Population, Motor Vehicle, and Traffic Information for the Utah Monitoring
Site
Site
BTUT
2007
Estimated
County
Population
288,146
Number
of
Vehicles
Registered
230,868
Vehicles
per Person
(Registration:
Population)
0.80
Population
Within
10 Miles
251,597
Estimated
10-mile
Vehicle
Ownership
201,584
Annual
Average
Traffic
Data1
17,310
VMT
(thousands)
10,373
1 Daily Average Traffic Data reflects 2006 data from the Utah DOT
BOLD = EPA-designated NATTS Site
population within 10 miles of the site is presented. An estimate of 10-mile vehicle registration
was calculated by applying the county-level vehicle registration to population ratio to the
10-mile population surrounding the monitoring site. Table 27-2 also contains annual average
daily traffic information, as well as the year of the traffic data estimate and the source from
which it was obtained. Finally, Table 27-2 presents the daily VMT for the urban area.
Observations from Table 27-2 include the following:
• Davis County's population was in the middle of the range, as was its 10-mile
population, compared to all counties with NATTS or UATMP sites.
• The county-level vehicle registration and 10-mile ownership estimated both ranked
33rd compared to all counties with NATTS or UATMP sites.
• The vehicle per person ratio was slightly below average (0.90) compared to other
NATTS or UATMP sites.
• The traffic volume experienced near BTUT was in the mid-to-low range compared to
other monitoring sites. The traffic estimate used came from 1-15 near 500 West.
• The Ogden-Layton area VMT was the sixth lowest among urban areas with UATMP
or NATTS sites.
27.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Utah on sampling days, as well as over the course of the year.
27.2.1 Climate Summary
The Salt Lake City area has a semi-arid continental climate, with large seasonal
variations. The area is dry, located on the west side of the Wasatch Mountains, and the Great
27-5
-------
Salt Lake tends to have a moderating influence on the city's temperature. Moderate winds flow
out of the southeast on average (Ruffner and Bair, 1987).
27.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air concentration measurements.
The closest NWS weather station is located at Salt Lake City International Airport (WBAN
24127).
Table 27-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 27-3 is the 95 percent
confidence interval for each parameter. As shown in Table 27-3, average meteorological
conditions on sampling days appear warmer than the entire year. Extra samples were collected
in June and August, which may explain this difference.
27.2.3 Composite Back Trajectories for Sampling Days
Figure 27-3 is the composite back trajectory map for the Utah monitoring site for the
days on which samples were collected. Each line represents the 24-hour trajectory along which a
parcel of air traveled toward the monitoring site on a sampling day. Each concentric circle
around the site in Figure 27-3 represents 100 miles.
27-6
-------
Table 27-3. Average Meteorological Conditions near the Utah Monitoring Site
Site
BTUT
Closest NWS
Station and
WBAN
Salt Lake City
International
24127
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
68.16
±5.40
64.70
±2.37
Average
Temperature
(op)
57.05
±5.00
54.08
±2.16
Average
Dew Point
Temperature
(°F)
32.21
±2.47
31.44
±1.10
Average
Wet Bulb
Temperature
(»F)
44.31
±3.16
42.62
±1.39
Average
Relative
Humidity
(%)
47.74
±5.01
50.66
±2.14
Average
Sea Level
Pressure
(mb)
1014.48
±2.01
1015.39
±0.87
Average
Scalar Wind
Speed
(kt)
7.58
±0.73
6.99
±0.30
BOLD = EPA-designated NATTS Site
to
-------
Figure 27-3. Composite Back Trajectory Map for BTUT
to
-jj
oo
-------
Observations from Figure 27-3 include the following:
• Back trajectories originated from a variety of directions at BTUT. The majority of
trajectories originated from the south and southwest, although another cluster of
trajectories originated from the northwest.
• The 24-hour air shed domain for BTUT was slightly smaller in size compared to other
monitoring sites. The furthest away a trajectory originated was southern California,
nearly 500 miles away. However, most trajectories originated within 300 miles of the
site.
27.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at the Salt Lake City International Airport near
BTUT were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce a
customized wind rose. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figure 27-4 is the wind rose for
the Utah monitoring site on days that samples were collected.
Figure 27-4. Wind Rose for BTUT Sampling Days
NORTH"---.
20%
WEST
27-9
-------
Observations from Figure 27-4 for BTUT include the following:
• Although winds from a variety of directions were observed near BTUT, southerly and
southeasterly winds were prevalent near BTUT.
• Calm winds were observed for nearly 10 percent of the hourly measurements.
• Winds exceeding 11 knots made up nearly 18 percent of observations. The strongest
winds were generally out of the south.
27.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Utah
monitoring site were identified using the EPA risk screening process described in Section 3.2. In
brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 27-4 presents the pollutants that failed at least one screen for the Utah monitoring site and
highlights the site's pollutants of interest (shaded). BTUT sampled for VOC, carbonyls,
SNMOC, metals (PMio), and hexavalent chromium.
Observations from Table 27-4 include the following:
• Seventeen pollutants with a total of 499 measured concentrations failed at least one
screen for BTUT.
• Eleven pollutants were identified as pollutants of interest for BTUT: acetaldehyde,
acrolein, arsenic, benzene, 1,3-butadiene, cadmium, carbon tetrachloride, p-
dichlorobenzene, formaldehyde, manganese, and tetrachloroethylene.
• Of the eleven pollutants of interest, acetaldehyde, acrolein, benzene, and carbon
tetrachloride failed 100 percent of screens.
• Sixty-four percent of measured detections failed screens (of the pollutants that failed
at least one screen) for BTUT.
27-10
-------
Table 27-4. Comparison of Measured Concentrations and EPA Screening Values for
Utah Monitoring Site
the
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Bountiful, Utah - BTUT
Acetaldehyde
Formaldehyde
Acrolein
Benzene
Carbon Tetrachloride
Arsenic (PM10)
1,3 -Butadiene
Manganese (PM10)
Tetrachloroethylene
£>-Dichlorobenzene
Cadmium (PM10)
Nickel (PM10)
Hexavalent Chromium
Acrylonitrile
1 ,2-Dichloroethane
Toluene
1 , 1 ,2,2-Tetrachloroethane
Total
60
58
55
55
55
52
50
42
27
17
8
8
5
4
1
1
1
499
60
60
55
55
55
57
54
57
52
47
57
57
53
4
1
55
1
780
100.00
96.67
100.00
100.00
100.00
91.23
92.59
73.68
51.92
36.17
14.04
14.04
9.43
100.00
100.00
1.82
100.00
63.97
12.02
11.62
11.02
11.02
11.02
10.42
10.02
8.42
5.41
3.41
1.60
1.60
1.00
0.80
0.20
0.20
0.20
12.02
23.65
34.67
45.69
56.71
67.13
77.15
85.57
90.98
94.39
95.99
97.60
98.60
99.40
99.60
99.80
100.00
27.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Utah monitoring site. The averages presented are provided for the pollutants of interest for
the site. Complete site-specific summaries are provided in Appendices J through O. In addition,
concentration averages for select pollutants are presented from previous sampling years in order
to characterize concentration trends at the site, where applicable.
27.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
27-11
-------
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 27-5, where applicable.
Table 27-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Utah Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(Ug/m3)
Winter
Average
(Ug/m3)
Spring
Average
(Ug/m3)
Summer
Average
(Ug/m3)
Autumn
Average
(Ug/m3)
Annual
Average1
(Ug/m3)
Bountiful, Utah - BTUT
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Cadmium (PM10)
Carbon Tetrachloride
/>-Dichlorobenzene
Formaldehyde
Manganese (PM10)
Nickel (PM10)
Tetrachloroethylene
60
55
57
55
54
57
55
47
60
57
57
52
60
55
57
55
55
57
55
55
60
57
57
55
2.24
±0.54
0.59
±0.09
0.01
±0.01
1.29
±0.23
0.11
±0.03
O.01
±O.01
0.55
±0.03
0.25
±0.16
3.48
±0.83
0.01
±0.01
O.01
±O.01
0.34
±0.15
2.20
±0.99
0.34
±0.13
0.01
±0.01
1.56
±0.73
0.17
±0.08
O.01
±O.01
0.51
±0.05
0.11
±0.06
2.70
±0.99
0.01
±0.01
O.01
±O.01
0.30
±0.15
1.43
±0.30
0.52
±0.16
0.01
±0.01
0.90
±0.19
0.07
±0.02
O.01
±O.01
0.56
±0.08
0.14
±0.14
2.16
±0.40
0.01
±0.01
O.01
±O.01
0.20
±0.09
2.43
±0.62
0.73
±0.16
0.01
±0.01
1.12
±0.28
0.06
±0.01
O.01
±O.01
0.58
±0.06
0.12
±0.09
5.09
± 1.91
0.02
±0.01
O.01
±O.01
0.18
±0.09
2.85
±1.74
0.75
±0.21
0.01
±0.01
1.71
±0.38
0.14
±0.04
O.01
±O.01
0.56
±0.04
0.57
±0.54
3.67
±2.01
0.01
±0.01
O.01
±O.01
0.68
±0.59
2.24
±0.54
0.59
±0.09
0.01
±0.01
1.29
±0.23
0.10
±0.03
O.01
±O.01
0.55
±0.03
0.22
±0.14
3.48
±0.83
0.01
±0.01
O.01
±O.01
0.32
±0.15
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for BTUT from Table 27-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (3.48 ± 0.83 |ig/m3), acetaldehyde (2.24 ± 0.54 |ig/m3), and benzene
(1.29 ± 0.23 |ig/m3). The annual averages for these pollutants were the same as their
respective daily averages.
27-12
-------
• As shown in Tables 4-9 through 4-11, of the program-level pollutants of interest, the
following pollutants for BTUT were among the 10 highest average concentrations for
all NATTS and UATMP sites: benzene, l,3-butadiene,/?-dichlorobenzene,
tetrachloroethylene, arsenic, and manganese.
• Concentrations of 1,3-butadiene were higher in the winter and autumn. Although
formaldehyde concentrations appear highest in the summer and autumn, the large
confidence intervals indicate that the difference is not significant. This is also true of
the autumn/>-dichlorobenzene and tetrachloroethylene average concentrations. Most
of the concentrations of the pollutants of interest for BTUT did not vary significantly
by season.
27.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. BTUT has sampled carbonyls, VOC, metals, and SNMOC under the
UATMP and/or NATTS since 2003. Figures 27-5 through 25-9 present the three-year rolling
statistical metrics graphically for arsenic, benzene (TO-15 and SNMOC methods), 1,3-butadiene,
and formaldehyde for BTUT, respectively. The statistical metrics presented for calculating
trends include the substitution of zeros for non-detects.
Observations from Figure 27-5 for arsenic measurements include the following:
• The maximum arsenic concentration shown was measured in 2004. The maximum
concentration measured in 2004 was nearly twice the next highest concentration. The
three highest measurements since sampling began in 2003, were all measured in
2004.
• Overall, the central tendency did not vary significantly, as indicated by the closeness
of the first and third quartiles, the median, and the average concentrations.
• The average concentration is very similar to the third quartile for each time period
shown. Given that the third quartile represents the value below which 75 percent of
concentrations fall below, the average shown for each period was likely influenced by
outliers, such as the maximum concentrations shown for each period.
• The rolling average concentrations of arsenic have decreased over the time periods
shown.
• All but one arsenic concentration reported to AQS over the five years of sampling
were measured detections.
27-13
-------
Figure 27-5. Three-Year Rolling Statistical Metrics for Arsenic (PMio) Concentrations Measured at BTUT
to
35.00
30.00
25.00
20.00
=
_o
I
"a
=
O
U
15.00
10.00 -
5.00 -
2003-2005
2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 27-6. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at BTUT (SNMOC)
to
10.00 -i
9.00
7.00
•S 5.00 -
| «
3.00
2.00
1.00
2003-2005
2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum — Median — Maximum O Average • 3rd Quartile
-------
Figure 27-7. Three-Year Rolling Statistical Metrics for Benzene Concentrations Measured at BTUT (TO-15)
to
6.00
5.00
4.00
.o
o.
&
o
I 3.00
=
01
tj
=
O
U
2.00
1.00
2003-2005
2004-2006
Three-Year Period
2005-2007
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Figure 27-8. Three-Year Rolling Statistical Metrics for 1,3-Butadiene Concentrations Measured at BTUT
0.60 i
0.40
to
£
c.
-3
a
'1 0.30 -4
a
U
tj
I
3.20
0.10 -
0.00
2003-2005
2004-2006
Three-Year Period
2005-2007
• 1 st Quartile — Minimum ~" Median — Maximum O Average • 3rd Quartile
-------
Figure 27-9. Three-Year Rolling Statistical Metrics for Formaldehyde Concentrations Measured at BTUT
to
oo
4U.UU -
in nn
9s nn
c.
o.
=
0
•3 on nn
Concentra
t-
n c
3 i
3 C
in nn
^ nn
n nn
id
* — <
1
Sn s f;
1 1 I
2003-2005 2004-2006 2005-2007
Three-Year Period
• IstQuartile —Minimum —Median —Maximum O Average • 3rd Quartile
-------
Observations from Figure 27-6 for benzene (as measured by the SNMOC method)
include the following:
• The range of benzene concentrations is similar for each time period.
• The median, first and third quartiles, and rolling average concentrations have
decreased slightly over the time periods shown. However, the calculation of
confidence intervals shows that the decrease is not significant.
• All benzene concentrations reported to AQS over the five years of sampling were
measured detections.
Observations from Figure 27-7 for benzene (as measured by the TO-15 method) include
the following:
• Compared to benzene measurements from the SNMOC method, the central tendency
is less variable for the Method TO-15 measurements, as indicated by the closeness of
the first and third quartiles, the median, and the average concentrations.
• The maximum benzene concentration from the 2003-2005 time frame is more than
double the maximum benzene concentrations from the 2004-2006 and 2005-2007
time frames.
• Similar to the benzene measurements from the SNMOC method, the median, first and
third quartiles, and rolling average concentrations have decreased slightly over the
time periods shown. However, the calculation of confidence intervals shows that the
decrease is significant.
• All benzene concentrations reported to AQS over the five years of sampling were
measured detections.
Observations from Figure 27-8 for 1,3-butadiene measurements include the following:
• The plot for 1,3-butadiene is similar to plots of 1,3-butadiene for other program sites.
• The minimum, first quartile, and median concentrations for 1,3-butadiene were zero
for the 2003-2005 time frame. As the MDL for 1,3-butadiene improved (i.e.,
decreased), the detection rate for this pollutant increased, and a larger spread between
the metrics is observed. This pollutant was detected in 43 percent of samples during
the 2003-2005 time frame; 57 percent of samples during 2004-2006; and 82 percent
of samples during 2005-2007.
• The median and rolling average concentrations show a slight increase over the time
frames due to the inclusion of less zeros.
27-19
-------
Observations from Figure 27-9 for formaldehyde measurements include the following:
• The maximum formaldehyde concentration shown was measured in 2004, and is
more than twice the second highest concentration, which is the maximum
concentration shown for the 2005-2007 period.
• The rolling average concentration increased slightly from 2003-2005 to 2004-2006,
then decreased to the previous level in 2005-2007. This is also true of the median
concentration.
• All formaldehyde concentrations reported to AQS over the five years of sampling
were measured detections.
27.5 Pearson Correlations
Table 27-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for BTUT from Table 27-6 include the following:
• Most of the correlations between the pollutants of interest and the meteorological
parameters for BTUT were weak.
• The exceptions include the strong positive correlations calculated between manganese
and the temperature and moisture parameters (except relative humidity). This
indicates that as temperature and moisture content increase, concentrations of
manganese also increase.
• 1,3-Butadiene exhibited a strong positive correlation with sea level pressure,
indicating that concentrations of this pollutant increase with increasing surface
pressure.
• Benzene and 1,3-butadiene both exhibited strong negative correlations with wind
speed. In addition, all but one of the pollutants of interest exhibited negative
correlations with wind speed, suggesting that concentrations of the pollutants of
interest may increase as wind speeds decrease.
27.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Sections 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
27-20
-------
Table 27-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Utah
Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Bountiful, Utah - BTUT
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Cadmium (PM10)
Carbon Tetrachloride
£>-Dichlorobenzene
Formaldehyde
Manganese (PM10)
Nickel (PM10)
Tetrachloroethylene
60
55
57
55
54
57
55
47
60
57
57
52
-0.04
0.31
-0.25
-0.14
-0.41
0.06
0.12
0.11
0.17
0.56
-0.08
0.12
-0.06
0.28
-0.28
-0.19
-0.45
0.03
0.15
0.09
0.18
0.53
-0.07
0.09
-0.02
0.39
-0.19
-0.03
-0.30
-0.03
0.12
0.14
0.08
0.42
0.11
0.12
-0.06
0.33
-0.28
-0.16
-0.43
0.02
0.15
0.11
0.15
0.51
-0.02
0.10
0.06
-0.20
0.31
0.25
0.45
-0.04
-0.17
-0.02
-0.18
-0.47
0.24
-0.04
0.30
0.00
0.32
0.37
0.59
0.07
-0.20
0.02
0.04
-0.17
-0.11
0.05
-0.35
-0.28
-0.45
-0.55
-0.52
-0.05
0.12
-0.16
-0.16
-0.11
0.00
-0.17
to
^1
to
-------
27.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Utah
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 27-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk values.
Observations about acrolein from Table 27-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• All of the seasonal averages of acrolein exceeded the intermediate MRL.
• Acrolein has no chronic MRL. Therefore, a chronic risk comparison could not be
conducted.
27.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Utah monitoring site and where the
annual average concentrations could be calculated, risk was further examined by reviewing
cancer and noncancer risk estimates from NATA and calculating cancer and noncancer surrogate
risk approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
noncancer surrogate risk approximations are presented in Table 27-8. The data from NATA are
presented for the census tract where the monitoring site is located. The pollutants of interest for
the site are bolded.
27-22
-------
Table 27-7. MRL Risk Screening Assessment Summary for the Utah Monitoring Site
Site
BTUT
Method
TO-15
Pollutant
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
#of
Exceedances/
#of
Measured
Detections
0/55
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
Winter
Average
(Ug/m3)
0.34
±0.13
Spring
Average
(Ug/m3)
0.52
±0.16
Summer
Average
(Ug/m3)
0.73
±0.16
Autumn
Average
(Ug/m3)
0.75
±0.21
ATSDR
Chronic
MRL
(Ug/m3)
-
Annual
Average1
(Ug/m3)
0.59
±0.09
BOLD = EPA-designated NATTS Site
BOLD = exceedance of the intermediate or chronic MRL
- = an MRL risk factor is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
^i
to
-------
Table 27-8. Cancer and Noncancer Risk Summary for the Monitoring Site in Utah
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Bountiful, Utah (BTUT) - Census Tract ID 49011126600
Acet aldehyde
Acrolein
Acrylonitrile
Arsenic (PM10)
Benzene
1,3-Butadiene
Cadmium (PM10)
Carbon Tetrachloride
p-Dichlorobenzene
1 ,2-Dichloroethane
Formaldehyde
Hexavalent Chromium
Manganese (PM10)
Nickel (PM10)
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.0018
0.000015
0.000011
0.000026
5.5E-09
0.012
~
0.00016
0.000058
0.000005
-
0.009
0.00002
0.002
0.00003
0.03
0.002
0.00002
0.04
0.8
2.4
0.0098
0.0001
0.00005
0.000065
~
0.27
0.4
1.13
0.08
0.01
0.01
1.52
0.11
O.01
0.21
0.03
0.03
1.23
0.01
O.01
O.01
0.04
0.11
3.25
2.52
—
0.05
1.22
11.87
3.37
0.11
3.15
0.36
0.71
0.01
0.68
~
0.05
2.40
0.68
-
0.12
4.04
0.01
0.01
0.05
0.05
O.01
0.01
0.01
0.01
0.12
0.01
0.01
O.01
~
O.01
0.01
2.24 ±0.54
0.59 ±0.09
0.04 ±0.01
0.01 ±0.01
1.29 ±0.23
0.10 ±0.03
O.01±O.01
0.55 ±0.03
0.22 ±0.14
0.04 ±0.01
3.48 ±0.83
0.01 ±0.01
0.01 ±O.01
O.01±O.01
0.05 ±O.01
0.32 ±0.15
5.34 ±3.45
4.47
—
2.46
4.55
9.04
3.13
0.51
8.30
2.42
1.10
0.02
0.37
~
0.31
3.15
1.61
-
0.25
29.35
0.02
0.04
0.04
0.05
0.01
0.01
0.01
0.01
0.36
0.01
0.20
0.03
~
O.01
0.01
to
^1
to
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
-------
The census tract information for the Utah monitoring site is as follows:
• The census tract for BTUT is 49011126600.
• This census tract had a population of 5,116, which represented approximately 2.1
percent of the county population in 2000.
Observations for BTUT from Table 27-8 include the following:
• The pollutants with the highest concentrations according to NATA were toluene,
benzene, and formaldehyde.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadiene, and carbon tetrachloride.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (4.04).
• The pollutants with the highest annual averages were toluene, formaldehyde, and
acetaldehyde.
• The pollutants with the highest cancer risk approximations were benzene, carbon
tetrachloride, and arsenic. The cancer risk approximation for benzene was similar to
the cancer risk estimate from NATA.
• Similar to the NATA results, acrolein was the only pollutant with a noncancer risk
approximation greater than 1.0. However, the noncancer risk approximation was an
order of magnitude higher than NATA.
27.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 27-9 and 27-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 27-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 27-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer tables.
27-25
-------
Table 27-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Utah
to
^1
to
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Bountiful, Utah (BTUT) - Davis County
Benzene
Formaldehyde
Acetaldehyde
Dichloromethane
1,3 -Butadiene
Tetrachloroethylene
£>-Dichlorobenzene
Naphthalene
Trichloroethylene
POM, Group 2
233.83
77.82
30.72
29.18
21.27
13.44
5.35
4.29
2.90
1.03
Benzene
1,3 -Butadiene
Naphthalene
Hexavalent Chromium
Tetrachloroethylene
Acetaldehyde
£>-Dichlorobenzene
POM, Group 2
Acrylonitrile
Arsenic, PM
1.82E-03
6.38E-04
1.46E-04
8.77E-05
7.93E-05
6.76E-05
5.89E-05
5.64E-05
3.05E-05
2.85E-05
Benzene
Carbon Tetrachloride
Arsenic
Acetaldehyde
1, 1,2,2-Tetrachloroethane
1,3 -Butadiene
Acrylonitrile
/>-Dichlorobenzene
Tetrachloroethylene
1 ,2-Dichloroethane
9.04
8.30
4.55
4.47
3.16
3.13
2.45
2.42
1.61
1.11
-------
to
^1
to
Table 27-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Utah
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Bountiful, Utah (BTUT) - Davis County
Toluene
Xylenes
Benzene
Hexane
Ethylbenzene
Methanol
Methyl isobutyl ketone
Formaldehyde
1,1,1 -Trichloroethane
Glycol ethers, gas
672.00
488.76
233.83
114.98
105.71
93.60
87.02
77.82
51.70
39.55
Acrolein
Hexamethylene- 1 ,6-
diisocyanate, gas
1,3 -Butadiene
Manganese, PM
Formaldehyde
Benzene
Xylenes
Chlorine
Cyanide Compounds, gas
Acetaldehyde
235,092.14
12,645.00
10,636.72
9,089.83
7,941.13
7,794.19
4,887.58
4,710.00
3,913.33
3,413.50
Acrolein
Formaldehyde
Acetaldehyde
Manganese
1,3 -Butadiene
Benzene
Arsenic
Nickel
Acrylonitrile
Cadmium
29.35
0.36
0.25
0.20
0.05
0.04
0.04
0.03
0.02
0.01
-------
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 27.3, BTUT sampled for VOC,
carbonyls, SNMOC, metals (PMio), and hexavalent chromium. In addition, the cancer and
noncancer surrogate risk approximations are limited to those sites sampling for a long enough
period for annual averages to be calculated.
Observations from Table 27-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Davis County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) were benzene, 1,3-butadiene, and naphthalene.
• Seven of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Benzene was the highest emitted pollutant, had the highest toxicity-weighted
emissions, and had the highest cancer risk approximation. Carbon tetrachloride and
arsenic had the second and third highest cancer surrogate risk approximations.
Carbon tetrachloride appeared on neither emissions-based list, while arsenic had the
tenth highest toxicity-weighted emissions.
Observations from Table 27-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Davis County.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, hexamethylene-l,6-diisocyanate (gas), and 1,3-
butadiene.
• Three of the highest emitted pollutants also had the highest toxicity-weighted
emissions.
• Acrolein, which had the highest noncancer risk approximation, also had the highest
toxicity-weighted emissions.
27-28
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27.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest for BTUT were acetaldehyde, acrolein, arsenic, benzene,
1,3-butadiene, cadmium, carbon tetrachloride, p-dichlorobenzene, formaldehyde,
manganese, and tetrachloroethylene.
»«» Formaldehyde had the highest daily average concentration among the pollutants of
interest.
»«» Seasonal averages of acrolein exceeded the A TSDR intermediate MRL health
benchmark.
27-29
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28.0 Site in Vermont
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Vermont, and integrates these concentrations with
emissions, meteorological, and risk information.
28.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Vermont site is located
in the Burlington-South Burlington, VT MSA. Figure 28-1 is a composite satellite image
retrieved from Google™ Maps showing the monitoring site in its rural location. Figure 28-2
identifies point source emission locations within 10 miles of the site as reported in the 2002 NEI
for point sources. Table 28-1 describes the area surrounding the monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
The UNVT monitoring is located on the Proctor Maple Research Farm in Underhill,
Vermont, east of the Burlington area. Mount Mansfield, the highest peak in Vermont, lies to the
east in Underhill State Park, less than three miles away. The Underhill Artillery Range is a few
miles to the south. Figure 28-1 shows that the area surrounding the site is rural in nature and
heavily forested. This site is intended to serve as a background site for the region for trends
assessment, standards compliance, and long-range transport assessment. As Figure 28-2 shows,
UNVT is located near only four point sources. These emission sources are involved in a variety
of activities.
Table 28-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the area surrounding the Vermont
monitoring site. County-level vehicle registration data for Chittenden County were not available
from the State of Vermont. Thus, state-level vehicle registration, from the Energy Information
Administration (EIA), was allocated to the county level using the proportion of county-level
population. County-level population information for this county was obtained from the
28-1
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Figure 28-1. Underbill, Vermont (UNVT) Monitoring Site
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to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
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Figure 28-2. NEI Point Sources Located Within 10 Miles of UNVT
irww» n-iOTW
.
WMww rf^K'-f,
Nat* Out to tK4IIy dwM j MKJ cttotifan m*
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Table 28-1. Geographical Information for the Vermont Monitoring Site
Site
Code
UNVT
AQS Code
50-007-0007
Location
Underbill
County
Chittenden
Micro- or
Metropolitan
Statistical Area
Burlington-South
Burlington, VT
Latitude
and
Longitude
44.52839,
-72.86884
Land Use
Forest
Location
Setting
Rural
Description of the
Immediate Surroundings
This site was established in 1988 and is located at the
western slope of Mount Mansfield at the north end in
Underbill, VT. The site is rural in nature and located
5 km southwest of the summit of Mount Mansfield, 6
km from Route 15, and 26 km east of Burlington.
This monitoring location meets all siting
requirements and criteria and has been approved
Vermont Air Pollution Control Division and EPA
Region I. The monitoring objective for ozone, PM2 5,
PMio, PM speciation and future trace-level
monitoring is regional scale background levels. The
monitoring objectives for the VOC, Carbonyl , metals
and CR+6 sample collection and analysis are to
assess background levels on a regional scale for short
and long-term trends, comparison to applicable state
standards and federal guidelines and assessment of
contribution of transported pollutants. WS/WD &
Temp/RH data is collected from a 10.0 meter tower.
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BOLD = EPA-designated NATTS Site
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Table 28-2. Population, Motor Vehicle, and Traffic Information for the Vermont
Monitoring Site
Site
UNVT
2007
Estimated
County
Population
151,826
Number
of
Vehicles
Registered
122,119
Vehicles
per Person
(Registration:
Population)
0.95
Population
Within
10 Miles
33,940
Estimated
10-mile
Vehicle
Ownership
32,105
Annual
Average
Traffic
Data1
1,200
VMT
(thousands)
3,013
1 Daily Average Traffic Data reflects 2005 data from the Chittenden County Metro Planning Organization
BOLD = EPA-designated NATTS Site
U.S. Census Bureau. Table 28-2 also includes a vehicle registration to county population ratio
(vehicles per person). In addition, the population within 10 miles of the site is presented. An
estimate of 10-mile vehicle registration was calculated by applying the county-level vehicle
registration to population ratio to the 10-mile population surrounding the monitoring site. Table
28-2 also contains annual average daily traffic information, as well as the year of the traffic data
estimate and the source from which it was obtained. Finally, Table 28-2 presents the daily VMT
for the urban area.
Observations from Table 28-2 include the following:
• Chittenden County's population was in the mid-to-low range compared to all counties
with NATTS or UATMP sites. This is also true of its vehicle registration.
• Both the 10-mile radius population and vehicle registration ranked seventh lowest
compared to all counties with NATTS or UATMP sites.
• The vehicle per person ratio was nearly one vehicle per person. While this may seem
high, it ranked 22nd among all NATTS and UATMP sites.
• The traffic volume experienced near UNVT ranked third lowest compared to other
monitoring sites. The traffic estimate used came from Pleasant Valley Road, north of
Harvey Road.
• VMT for the Burlington area ranked fourth lowest compared to urban areas with
NATTS and UATMP monitoring sites.
28.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Vermont on sampling days, as well as over the course of the year.
28-5
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28.2.1 Climate Summary
The city of Burlington resides just to the east of Lake Champlain in northwest Vermont.
Lake Champlain has a moderating affect on the city, keeping the city slightly warmer than it
could be given its New England location. The state of Vermont is affected by most storm
systems that track across the country, producing variable weather. Average annual winds come
from the south, ahead of advancing weather systems. However, these storm systems are
moderated somewhat due to the Adirondacks to the west and Green Mountains to the east
(Ruffner and Bair, 1987).
28.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Morrisville-Stowe Street Airport (WBAN 54771).
Table 28-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 28-3 is the 95 percent
confidence interval for each parameter. As shown in Table 28-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
28.2.3 Composite Back Trajectories for Sampling Days
Figure 28-3 is the composite back trajectory map for the Vermont monitoring site for the
days on which samples were collected. Each line represents the 24-hour trajectory along which a
parcel of air traveled toward the monitoring site on a sampling day. Each concentric circle
around the site in Figure 28-3 represents 100 miles.
28-6
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Table 28-3. Average Meteorological Conditions near the Vermont Monitoring Site
Site
UNVT
Closest NWS
Station and
WBAN
Morrisville-
Stowe State
Airport
54771
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
54.94
±5.49
53.03
±2.31
Average
Temperature
(op)
44.56
±5.07
43.10
±2.13
Average
Dew Point
Temperature
(°F)
34.35
±5.18
33.27
±2.13
Average
Wet Bulb
Temperature
(»F)
40.09
±4.71
38.83
±1.97
Average
Relative
Humidity
(%)
70.44
±2.93
71.48
± 1.19
Average
Sea Level
Pressure
(mb)
1016.94
±1.81
1016.55
±0.80
Average
Scalar Wind
Speed
(kt)
3.03
±0.50
3.17
±0.22
BOLD = EPA-designated NATTS Site
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Figure 28-3. Composite Back Trajectory Map for UNVT
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Observations from Figure 28-3 include the following:
• Back trajectories originated from a variety of directions at UNVT, although there
were fewer trajectories originating from the east and southeast.
• The 24-hour air shed domain for UNVT was similar in size compared to other
monitoring sites. The furthest away a trajectory originated was east Tennessee, or
nearly 800 miles away. However, most trajectories originated within 500 miles of the
site.
28.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station near UNVT were uploaded into a wind rose
software program, WRPLOT (Lakes, 2006) to produce customized wind roses. A wind rose
shows the frequency of wind directions on a 16-point compass, and uses different shading to
represent wind speeds. Figure 28-4 is the wind rose for the Vermont monitoring site on days that
samples were collected.
Figure 28-4. Wind Rose for UNVT Sampling Days
•NORTH"---.
10%
•SOUTH .---
WIND SPEED
(Knots)
HH «22
^| 17 - 21
^| 11 • 17
^| 7- 11
CH 4-7
^| 2- 4
Calms: 53.52%
28-9
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Observations from Figure 28-4 for UNVT include the following:
• Calm winds were prevalent near UNVT, as calm winds were observed for over one-
half of the hourly measurements.
• For winds greater than 2 knots, northerly and southerly winds were observed most
frequently.
• Winds exceeding 11 knots made up less than three percent of observations.
28.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Vermont
monitoring site were identified using the EPA risk screening process described in Section 3.2. In
brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 28-4 presents the pollutants that failed at least one screen for the Vermont monitoring site
and highlights the site's pollutants of interest (shaded). UNVT sampled for hexavalent
chromium only.
Table 28-4. Comparison of Measured Concentrations and EPA Screening Values for the
Vermont Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Underbill, Vermont - UNVT
Hexavalent Chromium
Total
0
0
11
11
0.00
0.00
0.00
0.00
Observations from Table 28-4 include the following:
• Hexavalent chromium was detected in 11 samples, but did not fail any screens.
• In order to facilitate analysis, hexavalent chromium was considered UNVT's
pollutant of interest.
28-10
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28.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Vermont monitoring site. The averages presented are provided for the pollutants of
interest for the monitoring site. Complete site-specific statistical summaries are provided in
Appendices J through O. In addition, concentration averages for select pollutants are presented
from previous sampling years in order to characterize concentration trends at the site, where
applicable.
28.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for hexavalent
chromium, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 28-5, where applicable.
The averages presented in Table 28-5 are shown in ng/m3 for ease of viewing.
Table 28-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Vermont Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average1
(ng/m3)
Underbill, Vermont - UNVT
Hexavalent Chromium
11
60
0.016
±0.011
NR
NR
NR
NR
0.006
± 0.002
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or
number of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
28-11
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Observations for UNVT from Table 28-5 include the following:
• The daily average concentration of hexavalent chromium was higher than the annual
average (0.016 ± 0.011 ng/n
the substitution of 1/2 MDL
average (0.016 ±0.011 ng/m3 vs. 0.006 ± 0.002 ng/m3), which illustrates the effect of
• Compared to other program sites sampling hexavalent chromium, the daily average
concentration for UNVT was the fifth lowest.
• Seasonal averages of hexavalent chromium could not be calculated due to the low
number of detections in each season.
28.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. UNVT has not sampled continuously for five years as part of the
National Monitoring Programs; therefore, the trends analysis was not conducted.
28.5 Pearson Correlations
Table 28-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for UNVT from Table 28-6 include the following:
• All of the correlations for UNVT were relatively weak.
28.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
28.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Vermont
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
28-12
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Table 28-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Vermont
Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Underbill, Vermont - UNVT
Hexavalent Chromium
11
0.02
0.25
0.40
0.35
0.48
-0.11
-0.31
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28-13
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results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. None of the measured
concentrations or calculated average of hexavalent chromium exceeded any of the MRL risk
values for UNVT.
28.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutant of interest for the Vermont monitoring site and where the annual
average concentrations could be calculated, risk was further examined by reviewing cancer and
noncancer risk estimates from NATA and calculating cancer and noncancer surrogate risk
approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
noncancer surrogate risk approximations are presented in Table 28-7. The data from NATA are
presented for the census tract where the monitoring site is located. The pollutant of interest for
the site are bolded.
The census tract information for UNVT is as follows:
• The UNVT monitoring site is located in census tract 50007002900.
• The population for the census tract where the UNVT monitoring site is located was
6,037, which represented four percent of Chittenden County's population in 2000.
Observations for UNVT from Table 28-7 include the following:
• The NATA-modeled concentration for hexavalent chromium was less than 0.01
|ig/m3, as was the annual average.
• The cancer risk from hexavalent chromium according to NATA (0.02 in-a-million)
was slightly lower than the cancer risk approximation (0.08 in-a-million), although
both were low.
• The noncancer risk according to NATA and the noncancer risk approximation for
hexavalent chromium were both less than 0.01.
28-14
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Table 28-7. Cancer and Noncancer Risk Summary for the Monitoring Site in Vermont
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Hg/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Hg/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Underbill, Vermont (UNVT) - Census Tract ID 50007002900
Hexavalent Chromium
0.012
0.0001
0.01
0.02
0.01
0.01
±0.01
0.08
0.01
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
Bold = pollutant of interest
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28.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 28-8 and 28-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 28-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 28-9
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 28.3, IHSTVT sampled for
hexavalent chromium. In addition, the cancer and noncancer surrogate risk approximations are
limited to those sites sampling for a long enough period for annual averages to be calculated.
Observations from Table 28-8 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Chittenden County.
• Benzene was also the pollutant with the highest toxicity-weighted emissions (of the
pollutants with cancer UREs), followed by 1,3-butadiene and arsenic.
• Seven of the highest emitted pollutants also had the highest toxicity-weighted
emissions for Chittenden County.
• Hexavalent chromium, which was the only pollutant sampled at UNVT, had the fifth
highest toxicity-weighted emissions for Chittenden County. This pollutant did not
appear on the list of highest emitted pollutants.
28-16
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Table 28-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Vermont
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Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Underbill, Vermont (UNVT) - Chittenden County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Dichloromethane
Tetrachloroethylene
Naphthalene
/>-Dichlorobenzene
Trichloroethylene
POM, Group 2
228.09
62.58
22.11
20.63
14.44
7.53
4.23
3.19
1.67
1.54
Benzene
1,3 -Butadiene
Arsenic, PM
Naphthalene
Hexavalent Chromium
POM, Group 5
POM, Group 2
Acetaldehyde
Tetrachloroethylene
/>-Dichlorobenzene
1.78E-03
6.19E-04
1.91E-04
1.44E-04
1.31E-04
9.15E-05
8.47E-05
4.86E-05
4.44E-05
3.50E-05
Hexavalent Chromium 0.08
-------
to
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oo
Table 28-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Vermont
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Noncancer Risk
Approximation
Pollutant (HQ)
Underbill, Vermont (UNVT) - Chittenden County
Toluene
Xylenes
Benzene
Methanol
Ethylbenzene
Hexane
Formaldehyde
Ethylene glycol
Hydrochloric acid
Acetaldehyde
521.82
381.07
228.09
93.71
86.95
63.53
62.58
29.17
26.23
22.11
Acrolein
Manganese, PM
1,3 -Butadiene
Benzene
Formaldehyde
Chlorine
Xylenes
Acetaldehyde
Nickel, PM
Arsenic, PM
466,998.33
41,238.28
10,317.46
7,603.10
6,385.40
5,031.08
3,810.72
2,456.94
1,655.21
1,482.37
Hexavalent Chromium <0.01
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Observations from Table 28-9 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Chittenden County.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, manganese, and 1,3-butadiene.
• Four of the highest emitted pollutants Chittenden County also had the highest
toxicity-weighted emissions.
• Hexavalent chromium did not appear on the list of highest emitted pollutants or the
list of highest toxicity-weighted emissions for pollutants with a noncancer toxi city
factor. Its noncancer risk approximation was very low.
28.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Hexavalent chromium did not fail any screens for UNVT. However, it was
considered a pollutant of interest in order to allow data analyses to be conducted.
»«» Hexavalent chromium did not exceed any of the MRL health benchmarks.
28-19
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29.0 Site in Washington
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Washington, and integrates these concentrations
with emissions, meteorological, and risk information.
29.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Washington site is
located in the Seattle-Tacoma-Bellevue, WA MSA. Figure 29-1 is a composite satellite image
retrieved from Google™ Maps showing the monitoring site in its urban location. Figure 29-2
identifies point source emission locations within 10 miles of the site as reported in the 2002 NEI
for point sources. Table 29-1 describes the area surrounding the monitoring site and provides
supplemental geographical information such as land use, location setting, and locational
coordinates.
The SEWA monitoring is located in Seattle, at the southeast corner of the Beacon Hill
Reservoir. The reservoir and the Jefferson Park Golf Course to the east are separated by Beacon
Avenue. The reservoir, golf course, a middle school, and the VA Puget Sound Health Care
System, located to the south, are surrounded by residential neighborhoods, as shown in Figure
29-1. Interstate-5 (1-5), which runs north-south through Seattle, is less than a mile to the west
and intersects with 1-90. 1-90 runs east-west across Seattle, a couple of miles to the northwest of
the site. The area to the west of 1-5 is industrial. As Figure 29-2 shows, SEWA is located near
several industrial point sources. These emission sources are involved in a variety of activities,
including surface coating, liquids distribution, and waste disposal. The point source located
closest to SEWA is involved in producing fabricated metal products.
Table 29-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Washington monitoring site. County-level vehicle registration and population data for King
County were obtained from the Washington Department of Licensing and the U.S. Census
29-1
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Figure 29-1. Seattle, Washington (SEWA) Monitoring Site
to
VO
to
©2008 Google/ONAVTECH
Scale: 3cm = 200m
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Figure 29-2. NEI Point Sources Located Within 10 Miles of SEWA
i;.-i
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Table 29-1. Geographical Information for the Washington Monitoring Site
Site
Code
SEWA
AQS Code
53-033-0080
Location
Seattle
County
King
Micro- or
Metropolitan
Statistical Area
Seattle-Tacoma-
Bellevue, WA
Latitude
and
Longitude
47.5683,
-122.3081
Land Use
Industrial
Location
Setting
Suburban
Description of the
Immediate Surroundings
The Beacon Hill site is centrally located within the
Seattle urban area. The site is isolated within the
confines of the city's water reservoir. The neatest
roads are at least 1 km away. It is surrounded by
residential neighborhoods, Jefferson Park and a
middle school. It is about 100 meters above sea level.
The hill is part of a larger ridge defining the eastern
edge of an area of light industry including a major
seaport, an airport and warehousing and trucking
activity about 4 km west of the site. Interstate
freeways and arterial roads carrying large amounts of
traffic are closely situated 2 to 4 km northwest of the
site. The site is considered to be representative of 24
hour average PM2 5 levels within a 20 km radius
(Goswami 2002).
to BOLD = EPA-designated NATTS Site
-------
Table 29-2. Population, Motor Vehicle, and Traffic Information for the Washington
Monitoring Site
Site
SEWA
2007
Estimated
County
Population
1,859,284
Number
of
Vehicles
Registered
1,766,228
Vehicles
per Person
(Registration:
Population)
0.95
Population
Within
10 Miles
893,502
Estimated
10-mile
Vehicle
Ownership
848,783
Annual
Average
Traffic
Data1
232,000
VMT
(thousands)
69,967
1 Daily Average Traffic Data reflects 2006 data from the Washington State DOT
BOLD = EPA-designated NATTS Site
Bureau. Table 29-2 also includes a vehicle registration to county population ratio (vehicles per
person). In addition, the population within 10 miles of each site is presented. An estimate of 10-
mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 29-2 also
contains annual average daily traffic information as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 29-2 presents the daily VMT for the
urban area.
Observations from Table 29-2 include the following:
• SEWA's county and 10-mile populations were in the upper to mid-range compared to
other counties with NATTS or UATMP sites. This is also true for its county-level
and 10-mile vehicle ownership.
• The vehicle per person ratio was in the middle of the range compared to other
NATTS or UATMP sites.
• The traffic volume experienced near SEWA ranked second highest compared to other
monitoring sites. The traffic estimate used came from 1-5 near exit 162.
• The Seattle area VMT was the 12th highest among urban areas with UATMP or
NATTS sites.
29.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Washington on sampling days, as well as over the course of the year.
29-5
-------
29.2.1 Climate Summary
Seattle is located between the Puget Sound and Lake Washington, and is situated between
the Olympic Mountains to the west and the Cascades to the east. The city experiences a mild
climate as the mountains moderate storm systems that move into the Pacific Northwest and both
the mountains and the sound shield the city from the temperature extremes. Although the city is
known for being rainy, the actual precipitation totals tend to be lower compared to many
locations east of the Rocky Mountains (Ruffner and Bair, 1987).
29.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at Boeing Field/King County International Airport (WBAN
24234).
Table 29-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 29-3 is the 95 percent
confidence interval for each parameter. As shown in Table 29-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year.
29.2.3 Composite Back Trajectories for Sampling Days
Figure 29-3 is the composite back trajectory map for the Washington monitoring site for
the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the site in Figure 29-3 represents 100 miles.
29-6
-------
Table 29-3. Average Meteorological Conditions near the Washington Monitoring Site
Site
SEWA
Closest NWS
Station and
WBAN
Boeing Field/
King County
Intl Airport,
Seattle
24234
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
59.43
±3.11
59.16
±1.23
Average
Temperature
(op)
52.69
±2.68
52.37
±1.04
Average
Dew Point
Temperature
(°F)
42.94
±2.11
42.88
±0.80
Average
Wet Bulb
Temperature
(»F)
47.80
±2.17
47.61
±0.84
Average
Relative
Humidity
(%)
71.96
±2.73
72.49
±1.09
Average
Sea Level
Pressure
(mb)
1017.88
± 1.64
1018.00
±0.68
Average
Scalar Wind
Speed
(kt)
4.59
±0.52
4.79
±0.23
BOLD = EPA-designated NATTS Site
to
VO
-------
Figure 29-3. Composite Back Trajectory Map for SEWA
to
VO
oo
-------
Observations from Figure 29-3 include the following:
• Back trajectories originated from a variety of directions at SEW A, although
infrequently from the southeast.
• The 24-hour air shed domain for SEWA was comparable in size to other monitoring
sites. The furthest away a trajectory originated was more than 700 miles away, over
the Pacific Ocean. However, most trajectories originated within 300 miles of the site.
29.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at King County International near SEWA
were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce a
customized wind rose. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figure 29-4 is the wind rose for
the Washington monitoring site on days that samples were collected.
Figure 29-4. Wind Rose for SEWA Sampling Days
20%
•SOUTH ,--•
WIND SPEED
(Knots)
O >=Z2
^| 17 - 21
^| 1-1 - 17
• 7- 11
CH 4-7
Calms: 26.27%
29-9
-------
Observations from Figure 29-4 for SEWA include the following:
• Calm winds were prevalent near SEWA and were observed for more than 26 percent
of the hourly wind measurements.
• Southerly and south-southeasterly winds were frequently observed near SEWA.
• Winds exceeding 11 knots made up less than three percent of observations and were
most frequently measured for winds with a southerly component.
29.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the
Washington monitoring site were identified using the EPA risk screening process described in
Section 3.2. In brief, each pollutant's measured concentration was compared to its associated
risk screening value. If the daily concentration was greater than the risk screening value, then
the measured concentration "failed the screen." Pollutants of interest are those for which the
individual pollutant's total failed screens contribute to the top 95 percent of the site's total failed
screens. Table 29-4 presents the pollutants that failed at least one screen for the Washington
monitoring site and highlights the site's pollutants of interest (shaded). SEWA sampled for
VOC, carbonyls, metals (PMio), and hexavalent chromium.
Observations from Table 29-4 include the following:
• Thirteen pollutants with a total of 446 measured concentrations failed at least one
screen for SEWA.
• The following 10 pollutants were identified as pollutants of interest for SEWA:
acetaldehyde, acrolein, arsenic, benzene, 1,3-butadiene, carbon tetrachloride,
formaldehyde, manganese, nickel, and tetrachloroethylene.
• Of the 10 pollutants of interest, four failed 100 percent of screens for SEWA.
• Approximately 67 percent of measured detections failed screens (of the pollutants
that failed at least one screen) for SEWA.
29-10
-------
Table 29-4. Comparison of Measured Concentrations and EPA Screening Values for the
Washington Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Seattle, Washington - SEWA
Arsenic (PM10)
Carbon Tetrachloride
Benzene
Acrolein
1,3 -Butadiene
Acetaldehyde
Manganese (PM10)
Nickel (PM10)
Tetrachloroethylene
Formaldehyde
Hexavalent Chromium
1 ,2-Dichloroethane
Acrylonitrile
Total
60
60
60
58
56
41
37
20
17
15
11
6
5
446
60
60
60
58
60
59
60
60
59
59
56
6
5
662
100.00
100.00
100.00
100.00
93.33
69.49
61.67
33.33
28.81
25.42
19.64
100.00
100.00
67.37
13.45
13.45
13.45
13.00
12.56
9.19
8.30
4.48
3.81
3.36
2.47
1.35
1.12
13.45
26.91
40.36
53.36
65.92
75.11
83.41
87.89
91.70
95.07
97.53
98.88
100.00
29.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Washington monitoring site. The averages presented are provided for the pollutants of
interest for the site. Complete site-specific statistical summaries are provided in Appendices J
through O. In addition, concentration averages for select pollutants are presented from previous
sampling years in order to characterize concentration trends at the site, where applicable.
29.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for the pollutants of
interest, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
29-11
-------
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual average concentrations are presented in Table 29-5, where
applicable.
Table 29-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Washington Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(jig/m3)
Winter
Average
(jig/m3)
Spring
Average
(jig/m3)
Summer
Average
(jig/m3)
Autumn
Average
(jig/m3)
Annual
Average1
(Hg/m3)
Seattle, Washington - SEWA
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
Manganese (PM10)
Nickel (PM10)
Tetrachloroethylene
59
58
60
60
60
60
59
60
60
59
59
60
60
60
60
60
59
60
60
60
0.93
±0.32
0.36
±0.05
O.01
± O.01
0.79
±0.13
0.09
±0.02
0.69
±0.04
0.93
±0.31
0.01
±0.01
O.01
±<0.01
0.16
±0.03
0.69
±0.18
0.26
±0.03
O.01
±<0.01
0.95
±0.28
0.11
±0.03
0.69
±0.07
0.80
±0.21
0.01
±0.01
O.01
±<0.01
0.18
±0.06
0.58
±0.25
0.38
±0.09
O.01
±<0.01
0.61
±0.15
0.05
±0.01
0.71
±0.06
0.52
±0.20
0.01
±0.01
O.01
±O.01
0.12
±0.02
1.40
±1.13
0.32
±0.10
O.01
±O.01
0.49
±0.10
0.05
±0.01
0.64
±0.09
1.31
±1.11
0.02
±0.01
O.01
±O.01
0.11
±0.03
1.05
±0.33
0.45
±0.11
O.01
±O.01
1.12
±0.31
0.13
±0.04
0.71
±0.07
1.11
±0.33
0.01
±0.01
O.01
±0.01
0.22
±0.08
0.93
±0.32
0.35
±0.05
O.01
±O.01
0.79
±0.13
0.09
±0.02
0.69
±0.04
0.93
±0.31
0.01
±0.01
O.01
±O.01
0.16
±0.03
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for SEWA from Table 29-5 include the following:
• The pollutants with the highest daily average concentrations by mass were
formaldehyde (0.93 ± 0.31 |ig/m3), acetaldehyde (0.93 ± 0.32 |ig/m3), and benzene
(0.79 ±0.13 |ig/m3). The annual averages for these pollutants were the same as their
respective daily averages.
• As shown in Table 4-11, of the program-level pollutants of interest, SEWA had the
highest daily average concentration of carbon tetrachloride. However, the
concentrations of this pollutant did not vary significantly among the sites.
29-12
-------
• Of the eight sites sampling PMio metals, SEWA had the sixth highest daily average
arsenic concentration, but the second highest daily average manganese concentration,
as shown in Table 4-10.
• Most of the concentrations of the pollutants of interest for SEWA did not vary
significantly by season. Although the acetaldehyde and formaldehyde concentrations
were highest in the summer, the large confidence interval indicates that these
concentrations were likely affected by outliers.
29.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. SEWA has not sampled continuously for five years as part of the
National Monitoring Programs; therefore, the trends analysis was not conducted.
29.5 Pearson Correlations
Table 29-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for SEWA from Table 29-6 include the following:
• Most of the correlations between the pollutants of interest for SEWA were weak.
• The one exception was calculated between nickel and scalar wind speed (-0.50),
indicating that concentrations of nickel may increase as wind speeds decrease.
29.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
29.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data for the Washington
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
29-13
-------
Table 29-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the
Washington Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Seattle, Washington - SEWA
Acetaldehyde
Acrolein
Arsenic (PM10)
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Formaldehyde
Manganese (PM10)
Nickel (PM10)
Tetrachloroethylene
59
58
60
60
60
60
59
60
60
59
0.21
0.13
-0.09
-0.32
-0.35
-0.23
0.17
0.00
0.45
-0.20
0.22
0.11
-0.10
-0.34
-0.38
-0.24
0.17
0.04
0.41
-0.21
0.26
0.08
0.00
-0.22
-0.27
-0.20
0.22
0.09
0.33
-0.11
0.24
0.10
-0.05
-0.30
-0.34
-0.23
0.20
0.06
0.39
-0.17
0.00
-0.07
0.25
0.40
0.39
0.17
0.02
0.07
-0.28
0.33
-0.13
-0.03
0.05
0.12
0.14
-0.03
-0.11
-0.17
-0.22
0.06
-0.36
-0.38
-0.37
-0.45
-0.44
-0.17
-0.38
-0.02
-0.50
-0.47
to
VO
29-14
-------
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. The results of these
comparisons are summarized in Table 29-7. Where a seasonal or annual average exceeds the
applicable MRL, the concentration is bolded. Only acrolein exceeded one or more of the MRL
risk factors.
Observations about acrolein from Table 29-7 include the following:
• None of the preprocessed daily measurements of acrolein exceeded the acute MRL.
• All of the seasonal averages of acrolein exceeded the intermediate MRL.
• Acrolein has no chronic MRL. Therefore, a chronic risk comparison could not be
conducted.
29.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutants that failed at least one screen at the Washington monitoring site and
where the annual average concentrations could be calculated, risk was further examined by
reviewing cancer and noncancer risk estimates from NATA and calculating cancer and
noncancer surrogate risk approximations (refer to Section 3.6.5 regarding the criteria for an
annual average and how cancer and noncancer surrogate risk approximations are calculated).
Concentration and risk estimates from NATA, annual averages, cancer UREs and/or noncancer
RfCs, and cancer and noncancer surrogate risk approximations are presented in Table 29-8. The
data from NATA are presented for the census tract where the monitoring site is located. The
pollutants of interest for the Washington monitoring site are bolded.
The census tract information for the SEWA monitoring site is as follows:
• The census tract for SEWA is 53033010000.
• This census tract had a population of 8,139 in 2000 and represented approximately
0.1 percent of the King County population.
29-15
-------
Table 29-7. MRL Risk Screening Assessment Summary for the Washington Monitoring Site
Site
SEWA
Method
TO-15
Pollutant
Acrolein
ATSDR
Acute
MRL
(Ug/m3)
7.00
#of
Exceedances/
#of
Measured
Detections
0/58
ATSDR
Intermediate
MRL
(Ug/m3)
0.09
Winter
Average
(Ug/m3)
0.26
±0.03
Spring
Average
(Ug/m3)
0.38
±0.09
Summer
Average
(Ug/m3)
0.32
±0.10
Autumn
Average
(Ug/m3)
0.45
±0.11
ATSDR
Chronic
MRL
(Ug/m3)
-
Annual
Average1
(Ug/m3)
0.35
±0.05
BOLD = EPA-designated NATTS Site
BOLD = exceedance of the intermediate or chronic MRL
- = an MRL risk factor is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal averages.
Program completeness and sampling duration criteria were applied.
to
-------
Table 29-8. Cancer and Noncancer Risk Summary for the Monitoring Site in Washington
Pollutant
Cancer
URE
(Mg/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Ug/m3)
Cancer
Risk (in-
a-million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(Ug/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Seattle, Washington (SEWA) - Census Tract ID 53033010000
Acetaldehyde
Acrolein
Acrylonitrile
Arsenic (PM10)
Benzene
1,3-Butadiene
Carbon Tetrachloride
1 ,2-Dichloroethane
Formaldehyde
Hexavalent Chromium
Manganese (PM10)
Nickel (PM10)
Tetrachloroethylene
0.000002
—
0.000068
0.0043
0.000007
0.00003
0.000015
0.000026
5.5E-09
0.012
—
0.00016
0.000005
0.009
0.00002
0.002
0.00003
0.03
0.002
0.04
2.4
0.0098
0.0001
0.00005
0.000065
0.27
2.83
0.22
0.01
0.01
3.72
0.25
0.23
0.04
2.96
0.01
0.01
O.01
0.24
6.25
—
0.22
0.12
29.02
7.60
3.44
1.05
0.01
7.45
—
0.06
1.43
0.31
10.96
0.01
0.01
0.12
0.12
0.01
0.01
0.30
0.01
0.01
0.01
O.01
0.93 ±0.32
0.35 ±0.05
0.03 ±0.01
0.01 ±0.01
0.79 ±0.13
0.09 ±0.02
0.69 ±0.04
0.04 ±0.01
0.93 ±0.31
0.01 ±0.01
0.01 ±0.01
O.01±O.01
0.16 ±0.03
1.86
—
1.89
3.27
5.52
2.62
10.32
1.12
0.01
0.58
—
0.34
0.79
0.10
17.66
0.01
0.03
0.03
0.04
0.02
0.01
0.10
0.01
0.25
0.03
O.01
to
VO
Bold = pollutant of interest
— = a URE or RfC is not available
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
-------
Observations for SEWA from Table 29-8 include the following:
• The pollutants with the highest concentrations according to NATA were benzene,
formaldehyde, and acetaldehyde.
• The pollutants with the highest cancer risks according to NATA were benzene, 1,3-
butadiene, and hexavalent chromium.
• The only pollutant with a noncancer HQ greater than 1.0 according to NATA was
acrolein (10.96).
• The pollutants with the highest annual averages were formaldehyde, acetaldehyde,
and benzene.
• The pollutants with the highest cancer surrogate risk approximations were carbon
tetrachloride, benzene, and arsenic.
• Similar to the NATA results, acrolein was the only pollutant with a noncancer
surrogate risk approximation greater than 1.0 (17.66).
29.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 29-9 and 29-10 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 29-9 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 29-10
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in section 29.3, SEWA sampled for VOC,
carbonyls, metals (PMi0), and hexavalent chromium. In addition, the cancer and noncancer
29-18
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Table 29-9. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Washington
to
VO
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Pollutant
Cancer Risk
Approximation
(in-a-million)
Seattle, Washington (SEWA) - King County
Benzene
Formaldehyde
Acetaldehyde
1,3 -Butadiene
Tetrachloroethylene
Dichloromethane
Naphthalene
Trichloroethylene
£>-Dichlorobenzene
POM, Group 2
2,923.39
934.78
331.30
259.07
138.17
114.89
65.02
46.08
37.69
26.10
Benzene
1,3 -Butadiene
Naphthalene
POM, Group 2
Hexavalent Chromium
POM, Group 3
Tetrachloroethylene
Acetaldehyde
£>-Dichlorobenzene
Arsenic, PM
2.28E-02
7.77E-03
2.21E-03
1.44E-03
1.15E-03
9.27E-04
8.15E-04
7.29E-04
4.15E-04
3.39E-04
Carbon Tetrachloride
Benzene
Arsenic
1,3 -Butadiene
Acrylonitrile
Acetaldehyde
1 ,2-Dichloroethane
Tetrachloroethylene
Hexavalent Chromium
Nickel
10.32
5.52
3.27
2.62
1.88
1.86
1.12
0.79
0.58
0.34
-------
to
VO
to
o
Table 29-10. Top 10 Emissions, Toxicity-Weighted Emissions, and Noncancer Risk Approximations for Pollutants with
Noncancer RfCs for the Monitoring Site in Washington
Top 10 Total Emissions for Pollutants
with Noncancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Noncancer Toxicity- Weighted
Emissions
(County-Level)
Pollutant
Noncancer
Toxicity
Weight
Top 10 Noncancer Risk Approximations
Based on Annual Average Concentrations
(Site-Specific)
Pollutant
Noncancer Risk
Approximation
(HQ)
Seattle, Washington (SEWA) - King County
Toluene
Xylenes
Benzene
Methanol
Ethylbenzene
Formaldehyde
Hexane
Acetaldehyde
Ethylene glycol
Methyl isobutyl ketone
5,946.83
3,977.64
2,923.39
943.62
942.44
934.78
924.09
331.30
323.55
277.23
Acrolein
1,3 -Butadiene
Benzene
Formaldehyde
Xylenes
Acetaldehyde
Naphthalene
Manganese, PM
Toluene
Glycol ethers, gas
2,765,000.43
129,536.33
97,446.39
95,385.82
39,776.40
36,810.83
21,673.25
16,987.49
14,867.08
7,938.13
Acrolein
Manganese
Acetaldehyde
Formaldehyde
1,3 -Butadiene
Nickel
Benzene
Arsenic
Carbon Tetrachloride
Acrylonitrile
17.66
0.25
0.10
0.10
0.04
0.03
0.03
0.03
0.02
0.01
-------
surrogate risk approximations are limited to those sites sampling for a long enough period for
annual averages to be calculated.
Observations from Table 29-9 include the following:
• Benzene, formaldehyde, and acetaldehyde were the highest emitted pollutants with
cancer UREs in Seattle.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
cancer UREs) were benzene, 1,3-butadiene, and naphthalene.
• Seven of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Carbon tetrachloride was the pollutant with the highest cancer surrogate risk
approximation, followed by benzene and arsenic. Carbon tetrachloride appeared on
neither emissions-based list; arsenic appeared on the list of highest toxi city-weighted
emissions but not the list of highest emitted pollutants; and benzene appeared on all
three lists.
• Four of the 10 pollutants with the highest cancer risk approximations, also appear on
both emissions-based lists (acetaldehyde, benzene, 1,3-butadiene, and
tetrachl oroethy 1 ene).
Observations from Table 29-10 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Seattle.
• The pollutants with the highest toxi city-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, 1,3-butadiene, and benzene.
• Five of the highest emitted pollutants also had the highest toxi city-weighted
emissions.
• Acrolein, which had the highest noncancer risk approximation, also had the highest
toxicity-weighted emissions.
• Formaldehyde, acetaldehyde, and benzene appeared on all three lists.
29-21
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29.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» The pollutants of interest for SEWA were acetaldehyde, acrolein, arsenic, benzene,
1,3-butadiene, carbon tetrachloride, formaldehyde, manganese, nickel, and
tetrachloroethylene.
»«» Formaldehyde and acetaldehyde had the highest daily average concentrations for
SEWA.
»«» Seasonal averages of acrolein exceeded the intermediate MRL health benchmark.
29-22
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30.0 Site in Wisconsin
This section explores the spatial and temporal characteristics of the ambient monitoring
concentrations measured at the NATTS site in Wisconsin, and integrates these concentrations
with emissions, meteorological, and risk information.
30.1 Site Characterization
This section characterizes the monitoring site by providing geographical and physical
information about the location of the site and the surrounding area. The Wisconsin site is located
in Mayville, northwest of Milwaukee and northeast of Madison. Figure 30-1 is a composite
satellite image retrieved from Google™ Maps showing the monitoring site in its rural location.
Figure 30-2 identifies point source emission locations within 10 miles of the site as reported in
the 2002 NEI for point sources. Table 30-1 describes the area surrounding the monitoring site
and provides supplemental geographical information such as land use, location setting, and
locational coordinates.
The MVWI monitoring site is located to the east of Horicon National Wildlife Refuge.
The surrounding area is rural and agricultural in nature. The site serves as a rural background
site. However, the area is impacted by nearby urban areas, and as such, could show the impacts
on the wildlife sanctuary. Highway 33 to the north and Highway 67 to the west intersect less
than a mile from the site, as Figure 30-1 shows. Figure 30-2 shows that most of the point
sources surrounding MVWI are located to the west and northwest of the site. The majority of
these emission sources are involved in surface coating processes or processes employing fuel
combustion.
Table 30-2 presents information related to mobile source activity, such as population,
traffic, VMT, and estimated vehicle ownership information for the areas surrounding the
Wisconsin monitoring site. County-level vehicle registration and population data for Dodge
County were obtained from the Wisconsin Department of Transportation and the U.S. Census
Bureau. Table 30-2 also includes a vehicle registration to county population ratio (vehicles per
person). In addition, the population within 10 miles of the site is presented. An estimate of
30-1
-------
Figure 30-1. Mayville, Wisconsin (MVWI) Monitoring Site
o
to
©2008 Google/ONAVTECH
Scale: 3cm = 1 mile
-------
Figure 30-2. NEI Point Sources Located Within 10 Miles of MVWI
•
•r-jjmv tfliwi
Hot*. Out tortslHj dwiwi) und nKeacxin thKctil i«c*m
may not r«»r«enl at ladlnwi MOm th* an* of nteint
Legend
-ft MVWI NATTS site
10 mile radius
_J County boundary
Source Category Group (No. of Facilities}
o Fabricated Metal Products Facility (3)
F Fuel Combustion Industrial Facility |7)
Integrated Iron 5 Steel Manufacturing Facility (1)
B Mineral Products Processing Industrial Facility (1)
S Surface Coating Processes Industrial Facility (5)
V&ste Treatment & Disposal Industrial Facility (3}
30-3
-------
Table 30-1. Geographical Information for the Wisconsin Monitoring Site
Site
Code
MVWI
AQS Code
55-027-0007
Location
Mayville
County
Dodge
Micro- or
Metropolitan
Statistical Area
Beaver Dam, WI
Latitude
and
Longitude
43.435,
oo ^07770
-oo. J£ 1 1 1 o
Land Use
Agricultural
Location
Setting
Rural
Description of the
Immediate Surroundings
Mayville is a designated rural NATTS site. The
Mayville air monitoring station is a multi-parameter
site located in rural southeast Wisconsin. The site is
located approximately 45 miles northwest of
Milwaukee. The Mayville site is located directly to
the east of the Horicon National Wildlife Refuge.
The monitoring station provides an excellent location
for a rural background air toxics monitoring station.
The site is rural but is located within an area affected
by a major urban area. The site also shows impact on
an important wildlife sanctuary. Current sampling at
the site compliments and supports the air toxics
monitoring effort at the site. It will in some cases
allow for comparison of the monitoring
methodologies (PM25 metals vs. PM10 metals). The
station was originally established for the study of
ozone, fine paniculate matter and regional haze.
Sampling for hexavalent chromium began in March
2005.
o
-k
BOLD = EPA-designated NATTS Site
-------
Table 30-2. Population, Motor Vehicle, and Traffic Information for the Wisconsin
Monitoring Site
Site
MVWI
2007
Estimated
County
Population
87,786
Number
of
Vehicles
Registered
92,255
Vehicles
per Person
(Registration:
Population)
1.05
Population
Within
10 Miles
24,804
Estimated
10-mile
Vehicle
Ownership
26,067
Annual
Average
Traffic
Data1
3,500
VMT
(thousands)
NA
1 Daily Average Traffic Data reflects 2004 data from the Wisconsin DOT
BOLD = EPA-designated NATTS Site
10-mile vehicle registration was calculated by applying the county-level vehicle registration to
population ratio to the 10-mile population surrounding the monitoring site. Table 30-2 also
contains annual average daily traffic information, as well as the year of the traffic data estimate
and the source from which it was obtained. Finally, Table 30-2 presents the daily VMT for the
urban area (where applicable).
Observations from Table 30-2 include the following:
• Dodge County's population was rather low compared to all counties with NATTS or
UATMP sites. This is also true of its 10-mile population.
• Both the county-level and 10-mile radius vehicle registrations were low compared to
counties with NATTS or UATMP sites.
• The vehicle per person ratio was slightly greater than one vehicle per person. This
ratio ranked 10th highest among all NATTS and UATMP sites.
• The traffic volume experienced near MVWI ranked sixth lowest compared to other
monitoring sites. The traffic estimate used came from the intersection of Highway 33
and Highway 67.
• VMT was unavailable for this area.
30.2 Meteorological Characterization
The following sections characterize the meteorological conditions near the monitoring
site in Wisconsin on sampling days, as well as over the course of the year.
30.2.1 Climate Summary
The town of Mayville is located to the northwest of Milwaukee. This area experiences a
highly variable, continental climate as weather systems frequently push across the region.
30-5
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Wintertime temperature extremes are moderated somewhat by the proximity to Lake Michigan.
Lake effect snows can occur with winds with an easterly component, although they are more
common closer to the coast (Ruffner and Bair, 1987).
30.2.2 Meteorological Conditions in 2007
Hourly meteorological data at a weather station near this site were retrieved for all of
2007. These data were used to determine how meteorological conditions on sampling days vary
from normal conditions throughout the year. Meteorological data were also used to calculate
correlations between meteorological parameters and ambient air measurements. The closest
NWS weather station is located at West Bend Municipal Airport (WBAN 04875).
Table 30-3 presents average temperature (average maximum and average), moisture
(average dew point temperature, average wet bulb temperature, and average relative humidity),
pressure (average sea level pressure), and wind information (average scalar wind speed) on days
samples were collected and for the entire year. Also included in Table 30-3 is the 95 percent
confidence interval for each parameter. As shown in Table 30-3, average meteorological
conditions on sampling days were fairly representative of average weather conditions throughout
the year. Sea level pressure was not recorded at the West Bend Municipal Airport.
30.2.3 Composite Back Trajectories for Sampling Days
Figure 30-3 is the composite back trajectory map for the Wisconsin monitoring site for
the days on which samples were collected. Each line represents the 24-hour trajectory along
which a parcel of air traveled toward the monitoring site on a sampling day. Each concentric
circle around the site in Figure 30-3 represents 100 miles.
Observations from Figure 30-3 include the following:
• Back trajectories originated from a variety of directions at MVWI, although less
frequently from the east.
• The 24-hour air shed domain for MVWI was one of the largest in size compared to
other monitoring sites. The furthest away a trajectory originated was south Alberta,
Canada, or nearly 1,100 miles away. However, most trajectories originated within
500 miles of the site.
30-6
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Table 30-3. Average Meteorological Conditions near the Wisconsin Monitoring Site
Site
MVWI
Closest NWS
Station and
WBAN
West Bend
Municipal
Airport
04875
Average
Type
Sampling
Day
All 2007
Average
Maximum
Temperature
(°F)
56.65
±5.53
55.52
±2.30
Average
Temperature
(op)
48.63
±4.98
47.55
±2.11
Average
Dew Point
Temperature
(°F)
39.47
±4.81
38.98
±2.07
Average
Wet Bulb
Temperature
(»F)
44.76
±4.90
44.31
±2.08
Average
Relative
Humidity
(%)
73.12
±3.16
74.49
± 1.26
Average
Sea Level
Pressure
(mb)
NA
NA
Average
Scalar Wind
Speed
(kt)
5.76
±0.74
5.74
±0.34
NA = Sea level pressure was not recorded at the West Bend Municipal Airport
BOLD = EPA-designated NATTS Site
-------
Figure 30-3. Composite Back Trajectory Map for MVWI
UJ
o
oo
0 50 100 200 300 400
-------
30.2.4 Wind Rose for Sampling Days
Hourly wind data from the weather station at West Bend Municipal Airport near MVWI
were uploaded into a wind rose software program, WRPLOT (Lakes, 2006) to produce a
customized wind rose. A wind rose shows the frequency of wind directions on a 16-point
compass, and uses different shading to represent wind speeds. Figure 30-4 is the wind rose for
the Wisconsin monitoring site on days that samples were collected.
Observations from Figure 30-4 for MVWI include the following:
• Calm winds were prevalent near MVWI, as calm winds were observed for nearly 27
percent of the hourly measurements.
• For winds greater than two knots, westerly and northwesterly winds were observed
most frequently.
• Winds exceeding 11 knots made up 12 percent of observations.
Figure 30-4. Wind Rose for MVWI Sampling Days
VFKT
30-9
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30.3 Pollutants of Interest
"Pollutants of interest" were determined for each site in order to allow analysts and
readers to focus on a risk-based subset of pollutants. The pollutants of interest for the Wisconsin
monitoring site were identified using the EPA risk screening process described in Section 3.2. In
brief, each pollutant's measured concentration was compared to its associated risk screening
value. If the daily concentration was greater than the risk screening value, then the measured
concentration "failed the screen." Pollutants of interest are those for which the individual
pollutant's total failed screens contribute to the top 95 percent of the site's total failed screens.
Table 30-4 presents the pollutants that failed at least one screen for the Wisconsin monitoring
site and highlights the site's pollutants of interest (shaded). MVWI sampled for hexavalent
chromium only.
Table 30-4. Comparison of Measured Concentrations and EPA Screening Values for the
Wisconsin Monitoring Site
Pollutant
#of
Failed
Screens
#of
Measured
Detections
%of
Screens
Failed
% of Total
Failures
Cumulative
%
Contribution
Mayville, Wisconsin - MVWI
Hexavalent Chromium
Total
0
0
29
29
0.00
0.00
0.00
0.00
Observations from Table 30-4 include the following:
• Hexavalent chromium was detected in 29 samples, but did not fail any screens.
• In order to facilitate analysis, hexavalent chromium is considered MVWI's pollutant
of interest.
30.4 Concentrations
This section presents various concentration averages used to characterize pollution levels
at the Wisconsin monitoring site. The averages presented are provided for the pollutant of
interest for the site. Complete site-specific summaries are provided in Appendices J through O.
In addition, concentration averages for select pollutants are presented from previous sampling
years in order to characterize concentration trends at the site, where applicable.
30-10
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30.4.1 2007 Concentration Averages
Daily, seasonal, and annual concentration averages were calculated for hexavalent
chromium, as described in Section 3.3. The daily average of a particular pollutant is simply the
average concentration of all measured detections. If there were at least seven measured
detections within each season, then a seasonal average was calculated. The seasonal average
includes 1/2 MDLs substituted for all non-detects. Finally, the annual average is the average
concentration of all measured detections and 1/2 MDLs substituted for non-detects. Annual
averages were calculated for monitoring sites where sampling began no later than February and
ended no earlier than November and where the completeness was greater than or equal to 85
percent. Daily, seasonal, and annual averages are presented in Table 30-5, where applicable.
The averages presented in Table 30-5 are shown in ng/m3 for ease of viewing.
Table 30-5. Daily, Seasonal, and Annual Average Concentrations of the Pollutants of
Interest for the Wisconsin Monitoring Site
Pollutant
#of
Measured
Detections
#of
Samples
Daily
Average
(ng/m3)
Winter
Average
(ng/m3)
Spring
Average
(ng/m3)
Summer
Average
(ng/m3)
Autumn
Average
(ng/m3)
Annual
Average1
(ng/m3)
Mayville, Wisconsin - MVWI
Hexavalent Chromium
29
60
0.016
± 0.005
NR
NR
0.016
± 0.006
0.007
± 0.002
0.010
± 0.003
NR = Not reportable due to the detection criteria for calculating a seasonal average
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number
of corresponding seasonal averages. Program completeness and sampling duration criteria were applied.
Observations for MVWI from Table 30-5 include the following:
• The daily average concentration of hexavalent chromium was slightly higher than the
annual average (0.016 ± 0.005 ng/m3 vs. 0.010 ± 0.003 ng/m3), which illustrates the
effect of the substitution of 1/2 MDL.
• MVWI had the fourth lowest daily average concentration of hexavalent chromium
among sites sampling this pollutant.
• Only summer and autumn seasonal average concentrations of hexavalent chromium
could be calculated due to the low number of detections.
30-11
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30.4.2 Concentration Trends
A site-specific trends evaluation was completed for sites that have sampled one or more
of the NATTS core compounds since 2003 (a total of five consecutive years) or longer, as
described in Section 3.6.4. MVWI has not sampled continuously for five years as part of the
National Monitoring Programs; therefore, the trends analysis was not conducted.
30.5 Pearson Correlations
Table 30-6 is a summary of the Pearson correlation coefficients that were calculated to
determine the degree of correlation between concentrations of the pollutants of interest and select
meteorological parameters. (Refer to Section 3.4 for more information on Pearson correlations.)
Observations for MVWI from Table 30-6 include the following:
• All of the correlations for MVWI were relatively weak.
30.6 Additional Risk Screening Evaluations
The following screening evaluations were conducted to characterize risk at the Wisconsin
monitoring site. Refer to Section 3.3 and 3.6.5 for definitions and explanations regarding the
various risk factors, time frames, and calculations associated with risk.
30.6.1 Risk Screening Assessment Using MRLs
A risk screening was conducted by comparing the concentration data from the Wisconsin
monitoring site to the ATSDR acute, intermediate, and chronic MRLs, where available. As
described in Section 3.3, acute risk results from exposures of 1 to 14 days; intermediate risk
results from exposures of 15 to 364 days; and chronic risk results from exposures of one year or
greater. The preprocessed daily measurements of the pollutants that failed at least one screen
were compared to the acute MRL; the seasonal averages were compared to the intermediate
MRL; and the annual averages were compared to the chronic MRL. None of the measured
concentrations or calculated averages of hexavalent chromium exceeded any of the MRL risk
values for MVWI.
30-12
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Table 30-6. Pearson Correlations Between Selected Meteorological Parameters and the Pollutants of Interest for the Wisconsin
Monitoring Site
Pollutant
#of
Measured
Detections
Maximum
Temperature
Temperature
Dew Point
Temperature
Wet Bulb
Temperature
Relative
Humidity
Sea Level
Pressure
Scalar Wind
Speed
Mayville, Wisconsin - MVWI
Hexavalent Chromium
29
0.17
0.13
0.30
0.23
0.43
-
-0.36
~ = Sea level pressure was not recorded at the West Bend Municipal Airport
o
OJ
-------
30.6.2 Cancer and Noncancer Surrogate Risk Approximations
For the pollutant of interest for the Wisconsin monitoring site and where the annual
average concentrations could be calculated, risk was further examined by reviewing cancer and
noncancer risk estimates from NATA and calculating cancer and noncancer surrogate risk
approximations (refer to Section 3.6.5 regarding the criteria for an annual average and how
cancer and noncancer surrogate risk approximations are calculated). Concentration and risk
estimates from NATA, annual averages, cancer UREs and/or noncancer RfCs, and cancer and
noncancer surrogate risk approximations are presented in Table 30-7. The data from NATA are
presented for the census tract where the monitoring site is located. The pollutants of interest are
bolded.
The census tract information for MVWI is as follows:
• The MVWI monitoring site is located in census tract 55027961400.
• The population for the census tract where the MVWI monitoring site is located was
4,065, which represented about 4.7 percent of Dodge County's population in 2000.
Observations for MVWI from Table 30-7 include the following:
• The modeled concentration for hexavalent chromium from NATA was less than 0.01
|ig/m3, as was the annual average.
• The cancer risk from hexavalent chromium according to NATA and the cancer risk
approximation were both fairly low.
• The noncancer risk according to NATA and the noncancer risk approximation for
hexavalent chromium were both less than 0.01.
30.6.3 Risk-Based Emissions Assessment
In addition to the risk assessments discussed above, Tables 30-8 and 30-9 present a risk-
based evaluation of county-level emissions based on cancer and noncancer toxicity, respectively.
Table 30-8 presents the 10 pollutants with the highest emissions from the 2002 NEI, the 10
pollutants with the highest toxicity-weighted emissions, and the 10 pollutants with the highest
cancer risk approximations (in-a-million), as calculated from the annual averages. Table 30-9
presents similar information, but identifies the 10 pollutants with the highest noncancer risk
approximations (HQ), as calculated from the annual averages. The pollutants in these tables are
30-14
-------
o
(^
Table 30-7. Cancer and Noncancer Risk Summary for the Monitoring Site in Wisconsin
Pollutant
Cancer
URE
Oig/m3)
Noncancer
RfC
(mg/m3)
1999 NATA
Modeled
Concentration
(Hg/m3)
Cancer
Risk (in-a-
million)
Noncancer
Risk
(HQ)
2007 NATTS/UATMP
Annual
Average1
(jig/m3)
Cancer Risk
Approximation
(in-a-million)
Noncancer
Risk
Approximation
(HQ)
Mayville, Wisconsin (MVWI) - Census Tract ID 55027961400
Hexavalent Chromium
0.012
0.0001
0.01
0.07
0.01
0.01
±0.01
0.12
0.01
Bold = pollutant of interest
1 An annual average was calculated for the pollutants presented in this table without regard to the detection rate or number of corresponding seasonal
averages. Program completeness and sampling duration criteria were applied.
-------
Table 30-8. Top 10 Emissions, Toxicity-Weighted Emissions, and Cancer Risk Approximations for Pollutants with Cancer
UREs for the Monitoring Site in Wisconsin
Top 10 Total Emissions for Pollutants
with Cancer Risk Factors
(County-Level)
Pollutant
Emissions
(tpy)
Top 10 Cancer Toxicity-Weighted
Emissions
(County-Level)
Pollutant
Cancer
Toxicity
Weight
Top 10 Cancer Risk Approximations Based
on Annual Average Concentration
(Site-Specific)
Cancer Risk
Approximation
Pollutant (in-a-million)
Mayville, Wisconsin (MVWI) - Dodge County
Benzene
Formaldehyde
Dichloromethane
Tetrachloroethylene
Acetaldehyde
1,3 -Butadiene
1 ,3 -Dichloropropene
Trichloroethylene
Naphthalene
/>-Dichlorobenzene
170.23
31.34
14.94
14.82
12.20
8.06
6.30
5.09
4.26
3.28
Benzene
POM, Group 3
1,3 -Butadiene
Naphthalene
Tetrachloroethylene
POM, Group 2
Hexavalent Chromium
/>-Dichlorobenzene
Arsenic, PM
POM, Group 5
1.33E-03
2.85E-04
2.42E-04
1.45E-04
8.74E-05
8.48E-05
4.53E-05
3.61E-05
3.49E-05
2.73E-05
Hexavalent Chromium 0.12
-------
o
-------
limited to those that have cancer and noncancer risk factors, respectively. As a result, although
the actual value of the emissions are the same, the highest emitted pollutants in the cancer table
may be different from the noncancer table.
Each site sampled for specific types of pollutants. Therefore, the cancer and noncancer
surrogate risk approximations based on each site's annual averages are limited to those pollutants
for which each respective site sampled. As discussed in Section 30.3, MVWI sampled for
hexavalent chromium only. In addition, the cancer and noncancer surrogate risk approximations
are limited to those sites sampling for a long enough period for annual averages to be calculated.
Observations from Table 30-8 include the following:
• Benzene, formaldehyde, and dichloromethane were the highest emitted pollutants
with cancer UREs in Dodge County.
• Benzene was also the pollutant with the highest toxi city-weighted emissions (of the
pollutants with cancer UREs), followed by POM Group 3 and 1,3-butadiene.
• Five of the highest emitted pollutants in Dodge County also had the highest toxi city-
weighted emissions.
• Hexavalent chromium, which was the only pollutant sampled at MVWI, had the
seventh highest toxicity-weighted emissions for Dodge County. This pollutant did
not appear on the list of highest emitted pollutants.
Observations from Table 30-9 include the following:
• Toluene, xylenes, and benzene were the highest emitted pollutants with noncancer
RfCs in Dodge County.
• The pollutants with the highest toxicity-weighted emissions (of the pollutants with
noncancer RfCs) were acrolein, manganese, and benzene.
• Three of the highest emitted pollutants Dodge County also had the highest toxicity-
weighted emissions.
• Hexavalent chromium did not appear on the list of highest emitted pollutants on the
list of highest toxicity-weighted emissions for pollutants with a noncancer toxi city
factor. Its noncancer risk approximation was very low.
30-18
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30.7 Summary of the 2007 Monitoring Data
Results from several of the treatments described in this section include the following:
»«» Hexavalent chromium did not fail any screens for MVWI. However, it was
considered a pollutant of interest in order to allow data analyses to be conducted.
»«» Hexavalent chromium did not exceed any of the MRL health benchmarks.
30-19
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31.0 Data Quality
This section discusses the data quality of the ambient air concentrations for the 2007
NATTS and UATMP dataset. In accordance with the Data Quality Objectives (DQOs) presented
in ERG's EPA-approved QAPP, the following quality assessments were performed:
completeness, precision, and accuracy (also called bias). Completeness statistics were presented
in Section 2.0. The goal of 85 percent completeness was met by all but one site. As indicators
of the reliability and representativeness of experimental measurements, both precision and
accuracy are considered when interpreting ambient air monitoring data.
The quality assessments presented in this section show that the 2007 monitoring data are
of a known and high quality. The method precision for the collocated and duplicate analyses
varied from site to site, however the analytical precision level for replicate analyses met the data
quality objectives. Audit samples show that ERG is meeting the accuracy requirements of the
NATTS TAD.
31.1 Method Precision
Precision refers to the agreement between independent measurements performed
according to identical protocols and procedures. Method precision, which includes sampling and
analytical precision, quantifies random errors associated with collecting ambient air samples and
analyzing the samples in the laboratory and presents the most representative metric of precision.
Method precision is evaluated by comparing concentrations measured in duplicate or collocated
samples collected from the same air parcel. A duplicate sample is a sample collected
simultaneously with a primary sample using the same sampling system (i.e., two separate
samples through the same sampling system at the same time). This simultaneous collection is
typically achieved by teeing the line from the sampler to two canisters and doubling the flow rate
applied to achieve integration over the 24-hour collection period. Collocated samples are
samples collected simultaneously using two independent collection systems at the same location
at the same time.
31-1
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Both approaches provide valuable, but different, assessments of method precision:
• Analysis of duplicate samples provides information on the potential for variability (or
precision) expected from a single collection system, but does not provide information
on the variability expected between different collection systems (inter-system
assessment).
• Analysis of collocated samples provides information on the potential for variability
(or precision) expected between different collection systems, but does not provide
information on the variability expected from single collection systems (intra-system
assessment).
During the 2007 sampling year, duplicate and collocated samples were collected on at
least 10 percent of the scheduled sampling days, as outlined in the QAPP. Most of these samples
were analyzed in replicate. Collocated systems were not provided under the national contract for
sites sampling SVOC and were the responsibility of the participating agency. As such,
duplicate/collocated samples were not collected for most SVOC sites because there were few
collocated samplers and the samplers used were not equipped to collect duplicate samples.
Therefore, the method precision data for SVOC is based on only two sites for 2007 (RUCA and
SDGA), as they were the only sites with collocated systems.
Method precision was calculated by comparing the concentrations of the two
duplicates/collocates for each compound. Three parameters were used to quantify random errors
indicated by duplicate/collocated analyses of samples:
• Average concentration difference simply quantifies how duplicate or collocated
analytical results differ, on average, for each pollutant and each sample. When
interpreting central tendency estimates for specific pollutants sampled during the
2007 monitoring effort, participating agencies are encouraged to compare central
tendencies to the average concentration differences. If a pollutant's average
concentration difference exceeds or nearly equals its central tendency, the analytical
method may not be capable of precisely characterizing the concentrations. Therefore,
data interpretation for these pollutants should be made with caution. Average
concentration differences are calculated by subtracting the first analytical result from
the second analytical result and averaging the difference for each pollutant.
31-2
-------
Relative percent difference (RPD) expresses concentration differences relative to the
average concentrations measured during duplicate or collocated analyses. The RPD
is calculated as follows:
X
Where:
Xi is the ambient air concentration of a given pollutant measured in one sample;
Xi is the concentration of the same pollutant measured during duplicate or collocated
analysis; and
X is the arithmetic mean of X\ and Xi.
As this equation shows, duplicate or collocated analyses with low variability have
lower RPDs (and better precision), and duplicate or collocated analyses with high
variability have higher RPDs (and poorer precision).
• Coefficient of Variation (CV) provides a relative measure of data dispersion
compared to the mean.
X
Where:
o is the standard deviation of the sets of duplicate or collocated results;
X is the arithmetic mean of the sets of duplicate or collocated results;
The CV is used to determine the imprecision in survey estimates introduced from
analysis. A coefficient of one percent would indicate that the analytical results could
vary slightly due to sampling error, while a variation of 50 percent means that the
results are more imprecise. The CV for two duplicate or collocated samples was
calculated for each pollutant and each site.
The following approach was employed to estimate how precisely the ERG laboratory
analyzed samples:
• CVs, RPDs, and concentration differences were calculated for every duplicate or
collocated analysis performed during the program. In cases where pollutants were
not detected during duplicate/collocated analyses, non-detects were replaced with 1/2
the MDL.
• To make an overall estimate of method precision, program-average CVs, RPDs, and
absolute concentration differences were calculated for each pollutant by averaging the
values from the individual duplicate or collocated analyses. The expression "average
variability" or "median variability" for a given dataset refers to the average or median
CV.
31-3
-------
For each of the above calculations used to assess method precision, the substitution of 1/2 MDL
was made for all cases where one sample yielded a measurement and the other yielded a non-
detect. This substitution often resulted in higher CVs and RPDs.
Table 31-1 presents the 2007 Monitoring Program average method precision for VOC,
SNMOC, carbonyl compounds, metals, hexavalent chromium, and SVOC, presented as RPD and
CV. The overall carbonyl compounds and metals method precision (the average for all sites) met
the program DQOs, which are 15 percent CV and 25 percent RPD. The overall VOC, SNMOC,
hexavalent chromium, and SVOC method precision were above the program DQOs. The CVs
and RPDs that exceed the program DQOs were driven largely by several factors:
1) the inclusion of measurements below the MDL,
2) the substitution of /^ MDLs for non-detects,
3) concentration differences for very small concentrations may yield large CVs and
RPDs (i.e., 0.001 ng/m3 and 0.002 ng/m3 is 100 percent).
Tables 31-2 through 31-13, 31-15 through 31-18, 31-20 through 31-31, and 31-33
through 31-37 present average concentration differences, RPDs, and CVs as estimates of method
precision for VOC, SNMOC, carbonyls, and metal compounds, respectively. Tables 31-14,
31-19, 31-32, and 31-38 present the average CVs per pollutant, per site, and per method.
Table 31-39 presents the average CV for hexavalent chromium per site. Pollutants exceeding the
15 percent control limit for CV and/or the 25 percent control limit for RPD are bolded.
Table 31-1. Method Precision by Analytical Method
Method
VOC
SNMOC
Carbonyl Compounds
Metals
Hexavalent Chromium
SVOC
Average
Coefficient of
Variation
(%)
28.25
20.45
10.24
11.13
25.00
36.10
Average
Relative Percent
Difference
(%)
39.96
28.95
11.74
15.73
35.36
53.63
31-4
-------
31.1.1 VOC Method Precision
Table 31-2 presents the method precision for all duplicate and collocated VOC samples.
The average concentration differences observed for duplicate and collocated analyses of VOC
ranged from 0.001 ppbv (£r
-------
Table 31-2. VOC Method Precision: 306 Duplicate and Collocated Samples (Continued)
Pollutant
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
w-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
Trichlorofluoromethane
Trichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
m,p-Xylene
o-Xylene
Number of
Observations
0
304
3
299
265
29
74
280
306
272
1
275
306
5
304
3
110
303
303
302
293
67
303
304
Average RPD
(%)
NA
19.03
27.60
39.04
37.79
43.16
43.88
24.30
24.71
31.51
120.13
27.60
23.21
64.93
14.89
55.73
38.01
8.92
10.34
20.29
17.81
52.74
21.13
18.64
Average
Concentration
Difference (ppbv)
NA
0.05
0.004
0.28
0.06
0.03
0.08
0.04
0.58
0.05
0.01
0.05
0.31
0.01
0.03
0.01
0.06
0.05
0.04
0.04
0.04
0.09
0.09
0.05
Coefficient of
Variation (%)
NA
13.45
19.51
27.61
26.72
30.52
31.03
17.18
17.47
22.28
84.94
19.52
16.41
45.91
10.53
39.41
26.88
6.31
7.31
14.35
12.59
37.29
14.94
13.18
The VOC method precision for all collocated samples are presented in Table 31-3. The
range of variability was 4.04 percent (chlorobenzene) to 84.94 percent (1,1,2,2-
tetrachloroethane). The median variability was 24.92 percent.
Table 31-3. VOC Method Precision: 168 Collocated Samples
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Number of
Observations
136
168
168
19
6
166
0
11
7
Average RPD
(%)
72.81
13.93
35.59
32.81
43.66
19.66
NA
46.98
69.07
Average
Concentration
Difference (ppbv)
8.69
0.11
0.10
0.03
0.002
0.07
NA
0.19
0.01
Coefficient of
Variation (%)
51.48
9.85
25.17
23.20
30.87
13.90
NA
33.22
48.84
31-6
-------
Table 31-3. VOC Method Precision: 168 Collocated Samples (Continued)
Pollutant
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
OT-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 , 3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Acrylate
Ethyl ter/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl ter/-Butyl Ether
w-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1,2,4-Trimethylbenzene
Number of
Observations
154
163
124
168
22
137
136
168
2
5
20
0
1
7
148
166
1
24
0
0
6
168
0
1
1
168
0
0
166
0
165
146
20
39
155
168
153
1
153
168
4
166
1
78
166
166
166
Average RPD
(%)
15.40
26.81
55.06
10.20
5.72
38.18
28.53
8.05
51.38
115.81
74.11
NA
58.73
57.75
37.44
6.13
68.61
45.98
NA
NA
13.50
25.87
NA
43.74
11.97
27.98
NA
NA
23.63
NA
40.30
40.84
40.00
60.34
28.39
32.92
35.63
120.13
34.90
30.79
94.02
17.55
72.49
41.30
8.99
11.44
26.67
Average
Concentration
Difference (ppbv)
0.002
0.01
0.11
0.01
0.002
0.01
0.08
0.04
0.002
0.03
0.03
NA
0.003
0.004
0.01
0.03
0.004
0.03
NA
NA
0.002
0.04
NA
0.004
0.001
0.02
NA
NA
0.02
NA
0.36
0.03
0.01
0.03
0.01
1.02
0.01
0.01
0.02
0.37
0.01
0.003
0.005
0.01
0.03
0.01
0.02
Coefficient of
Variation (%)
10.89
18.96
38.93
7.22
4.04
27.00
20.18
5.69
36.33
81.89
52.40
NA
41.53
40.83
26.48
4.34
48.52
32.51
NA
NA
9.54
18.30
NA
30.93
8.46
19.79
NA
NA
16.71
NA
28.49
28.88
28.28
42.67
20.07
23.28
25.19
84.94
24.68
21.77
66.48
12.41
51.26
29.20
6.36
8.09
18.86
31-7
-------
Table 31-3. VOC Method Precision: 168 Collocated Samples (Continued)
Pollutant
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Number of
Observations
162
50
165
166
Average RPD
(%)
22.80
63.01
27.18
24.86
Average
Concentration
Difference (ppbv)
0.01
0.02
0.05
0.02
Coefficient of
Variation (%)
16.12
44.55
19.22
17.58
Table 31-4 presents the method precision results for all duplicate analyses for VOC. The
variability ranged from 6.12 percent (chloromethane) to 117.28 percent (1,1-dichloroethene).
The median variability was 16.44 percent.
Table 31-4. VOC Method Precision: 138 Duplicate Samples
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethy Ibenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1, 1-Dichloroethane
1,2-Dichloroethane
1, 1-Dichloroethene
cis- 1 ,2-Dichloroethylene
Number of
Observations
137
138
137
11
2
138
0
1
0
128
127
131
137
1
98
113
138
0
1
0
0
1
0
98
138
0
6
2
1
Average RPD
(%)
34.86
13.33
37.88
51.45
90.43
11.36
NA
74.80
NA
23.25
15.41
13.47
18.42
38.89
30.74
19.58
8.66
NA
130.06
NA
NA
58.73
NA
20.47
8.72
NA
28.83
165.85
128.68
Average
Concentration
Difference (ppbv)
0.38
0.17
0.17
0.02
0.002
0.09
NA
0.01
NA
0.07
0.07
0.13
0.07
0.003
0.07
0.07
0.11
NA
0.02
NA
NA
0.003
NA
0.07
0.10
NA
0.002
0.07
0.03
Coefficient of
Variation (%)
24.65
9.43
26.78
36.38
63.94
8.03
NA
52.89
NA
16.44
10.90
9.53
13.02
27.50
21.74
13.85
6.12
NA
91.96
NA
NA
41.53
NA
14.47
6.16
NA
20.39
117.28
90.99
31-8
-------
Table 31-4. VOC Method Precision: 138 Duplicate Samples (Continued)
Pollutant
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 , 3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl ferMSutyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
m,p-Xylene
o-Xylene
Number of
Observations
0
137
1
0
0
137
0
0
138
o
5
134
119
9
35
125
138
119
0
122
138
1
138
2
32
137
137
136
131
17
138
138
Average RPD
(%)
NA
15.63
28.40
NA
NA
11.37
NA
NA
14.42
27.60
37.79
34.74
55.81
32.12
20.21
16.50
27.39
NA
20.30
15.63
35.84
12.23
47.35
33.08
8.86
9.31
13.90
13.19
35.63
15.09
12.42
Average
Concentration
Difference (ppbv)
NA
0.11
0.002
NA
NA
0.06
NA
NA
0.08
0.004
0.19
0.10
0.10
0.12
0.07
0.14
0.08
NA
0.07
0.26
0.01
0.06
0.01
0.13
0.08
0.07
0.07
0.06
0.23
0.13
0.08
Coefficient of
Variation (%)
NA
11.05
20.08
NA
NA
8.04
NA
NA
10.20
19.51
26.72
24.56
39.47
22.71
14.29
11.66
19.37
NA
14.36
11.06
25.34
8.65
33.48
23.39
6.27
6.58
9.83
9.33
25.20
10.67
8.78
Due to the focus on QA for the NATTS program in the NATTS TAD, Tables 31-5
through 31-13 present the VOC method precision results for all of the NATTS sites that sampled
VOC (BTUT, CAMS 35, CAMS 85, DEMI, GPCO, NBIL, PXSS, S4MO, and SEW A,
respectively). Shaded rows present results for the NATTS core compounds.
Table 31-5 presents the method precision results from VOC duplicate analysis for BTUT.
Variability ranged from 1.82 percent (chloromethane) to 29.50 percent (acetonitrile), with an
average variability of 9.50 percent.
31-9
-------
Table 31-5. VOC Method Precision: 12 Duplicate Samples
for Bountiful, UT (BTUT)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl ter/-Butyl Ether
^-Octane
Propylene
Styrene
Number of
Observations
12
12
12
0
0
12
0
0
0
12
12
12
12
0
9
11
12
0
0
0
0
0
0
12
12
0
0
0
0
0
12
1
0
0
12
0
0
12
0
12
12
0
0
12
12
12
Average RPD
(%)
41.73
6.18
32.03
NA
NA
7.49
NA
NA
NA
7.81
12.03
33.11
15.78
NA
7.73
30.50
2.58
NA
NA
NA
NA
NA
NA
22.20
3.66
NA
NA
NA
NA
NA
5.15
28.40
NA
NA
5.33
NA
NA
8.17
NA
19.97
15.97
NA
NA
6.93
6.84
21.83
Average
Concentration
Difference (ppbv)
0.83
0.05
0.08
NA
NA
0.03
NA
NA
NA
0.001
0.01
0.19
0.01
NA
0.001
0.01
0.01
NA
NA
NA
NA
NA
NA
0.02
0.02
NA
NA
NA
NA
NA
0.01
0.002
NA
NA
0.001
NA
NA
0.01
NA
0.03
0.004
NA
NA
0.002
0.02
0.01
Coefficient of
Variation (%)
29.50
4.37
22.65
NA
NA
5.30
NA
NA
NA
5.52
8.51
23.41
11.16
NA
5.46
21.57
1.82
NA
NA
NA
NA
NA
NA
15.69
2.59
NA
NA
NA
NA
NA
3.64
20.08
NA
NA
3.77
NA
NA
5.78
NA
14.12
11.30
NA
NA
4.90
4.84
15.44
31-10
-------
Table 31-5. VOC Method Precision: 12 Duplicate Samples
for Bountiful, UT (BTUT) (Continued)
Pollutant
1, 1,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Number of
Observations
0
12
12
0
12
0
6
12
12
12
12
4
12
12
Average RPD
(%)
NA
12.38
10.24
NA
3.57
NA
5.40
3.88
2.63
8.73
9.01
32.69
6.77
6.40
Average
Concentration
Difference (ppbv)
NA
0.005
0.09
NA
0.001
NA
0.001
0.01
0.003
0.01
0.002
0.002
0.02
0.01
Coefficient of
Variation (%)
NA
8.75
7.24
NA
2.53
NA
3.82
2.74
1.86
6.17
6.37
23.12
4.78
4.53
Table 31-6 presents the method precision results from the VOC collocated analysis for
CAMS 35. Variability ranged from 0.87 percent (bromodichloromethane) to 78.18 percent
(dibromochloromethane), with a median variability of 14.53 percent.
Table 31-6. VOC Method Precision: 48 Collocated Samples
for Deer Park, TX (CAMS 35)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Number of
Observations
31
48
48
13
o
5
48
0
1
1
48
48
21
48
10
42
46
48
Average RPD
(%)
21.87
12.84
53.73
27.78
28.27
10.25
NA
1.24
54.34
15.75
20.55
53.19
6.36
5.32
35.83
19.93
6.92
Average
Concentration
Difference (ppbv)
0.02
0.11
0.11
0.03
0.002
0.05
NA
O.001
0.003
0.003
0.03
0.01
0.01
0.002
0.01
0.01
0.04
Coefficient of
Variation (%)
15.46
9.08
37.99
19.64
19.99
7.25
NA
0.87
38.42
11.14
14.53
37.61
4.50
3.76
25.34
14.10
4.89
31-11
-------
Table 31-6. VOC Method Precision: 48 Collocated Samples
for Deer Park, TX (CAMS 35) (Continued)
Pollutant
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1, 1-Dichloroethane
1 ,2-Dichloroethane
1, 1-Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 , 3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
^-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1, 1,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Number of
Observations
0
2
2
0
0
1
44
48
0
19
0
0
0
48
0
0
0
48
0
0
48
0
48
40
12
32
46
48
41
0
44
48
0
48
0
18
48
48
48
46
30
48
48
Average RPD
(%)
NA
103.38
110.57
NA
NA
66.43
24.90
4.52
NA
20.61
NA
NA
NA
14.73
NA
NA
NA
11.00
NA
NA
15.61
NA
30.84
41.01
53.26
26.90
25.07
16.44
21.05
NA
27.23
17.23
NA
8.25
NA
17.66
4.58
5.09
23.51
27.15
15.45
18.03
16.71
Average
Concentration
Difference (ppbv)
NA
0.01
0.005
NA
NA
0.004
0.004
0.02
NA
0.01
NA
NA
NA
0.01
NA
NA
NA
0.002
NA
NA
0.01
NA
0.09
0.01
0.02
0.03
0.01
0.31
0.005
NA
0.005
0.19
NA
0.001
NA
0.002
0.01
0.01
0.01
0.004
0.004
0.03
0.01
Coefficient of
Variation (%)
NA
73.10
78.18
NA
NA
46.97
17.60
3.20
NA
14.57
NA
NA
NA
10.41
NA
NA
NA
7.78
NA
NA
11.04
NA
21.81
29.00
37.66
19.02
17.73
11.63
14.89
NA
19.25
12.18
NA
5.84
NA
12.48
3.24
3.60
16.63
19.20
10.92
12.75
11.82
31-12
-------
Table 31-7 presents the method precision results from the VOC collocated analysis for
CAMS 85. Variability ranged from 7.44 percent (carbon tetrachloride) to 134.52 percent
(propylene), with an average variability of 50.50 percent.
Table 31-7. VOC Method Precision: 2 Collocated Samples
for Karnack, TX (CAMS 85)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Number of
Observations
0
2
2
0
0
2
0
0
0
2
2
0
2
0
2
2
2
0
0
0
0
0
0
2
2
0
2
0
0
0
2
0
0
0
2
0
0
2
0
Average RPD
(%)
NA
41.10
18.18
NA
NA
33.33
NA
NA
NA
NA
127.27
NA
10.53
NA
66.67
40.00
21.82
NA
NA
NA
NA
NA
NA
NA
NA
NA
175.00
NA
NA
NA
66.67
NA
NA
NA
66.67
NA
NA
54.55
NA
Average
Concentration
Difference (ppbv)
NA
0.30
0.03
NA
NA
0.18
NA
NA
NA
NA
0.07
NA
0.01
NA
0.01
0.01
0.12
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.14
NA
NA
NA
0.07
NA
NA
NA
0.01
NA
NA
0.03
NA
Coefficient of
Variation (%)
NA
29.06
12.86
NA
NA
23.57
NA
NA
NA
NA
90.00
NA
7.44
NA
47.14
28.28
15.43
NA
NA
NA
NA
NA
NA
NA
NA
NA
123.74
NA
NA
NA
47.14
NA
NA
NA
47.14
NA
NA
38.57
NA
31-13
-------
Table 31-7. VOC Method Precision: 2 Collocated Samples
for Karnack, TX (CAMS 85) (Continued)
Pollutant
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl ter/-Butyl Ether
^-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Number of
Observations
2
0
0
1
2
2
2
0
2
2
0
2
0
0
2
2
2
2
1
2
2
Average RPD
(%)
15.79
NA
NA
165.81
31.58
190.24
28.57
NA
177.78
10.53
NA
66.67
NA
NA
NA
NA
40.00
NA
167.90
42.86
54.55
Average
Concentration
Difference (ppbv)
0.06
NA
NA
0.05
0.03
12.09
0.01
NA
0.16
0.04
NA
0.01
NA
NA
NA
NA
0.02
NA
0.13
0.06
0.03
Coefficient of
Variation (%)
11.16
NA
NA
117.24
22.33
134.52
20.20
NA
125.71
7.44
NA
47.14
NA
NA
NA
NA
28.28
NA
118.72
30.30
38.57
Table 31-8 presents the method precision results from VOC collocated analysis for
DEMI. These results show a low- to high-level of variability, ranging from 0.97 percent (trans-
1,2-dichloroethylene) to 85.65 percent (vinyl chloride). The average CV, which was within the
program DQO, was 12.93 percent.
Table 31-8. VOC Method Precision: 10 Collocated Samples
for Dearborn, MI (DEMI)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Number of
Observations
10
10
10
0
0
10
0
0
Average RPD
(%)
20.76
6.45
41.93
NA
NA
6.38
NA
NA
Average
Concentration
Difference (ppbv)
0.05
0.04
0.09
NA
NA
0.01
NA
NA
Coefficient of
Variation (%)
14.68
4.56
29.65
NA
NA
4.51
NA
NA
31-14
-------
Table 31-8. VOC Method Precision: 10 Collocated Samples
for Dearborn, MI (DEMI) (Continued)
Pollutant
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
Number of
Observations
0
10
10
7
10
10
10
10
10
0
0
0
0
0
0
10
10
0
0
0
0
1
10
0
0
0
10
0
0
10
0
10
10
0
0
8
10
9
0
8
10
0
10
0
4
10
Average RPD
(%)
NA
14.00
5.11
38.41
8.12
6.42
18.50
50.00
8.18
NA
NA
NA
NA
NA
NA
10.30
6.38
NA
NA
NA
NA
1.37
14.45
NA
NA
NA
7.37
NA
NA
6.72
NA
42.55
32.85
NA
NA
7.38
8.55
16.28
NA
5.93
9.66
NA
13.81
NA
15.88
6.11
Average
Concentration
Difference (ppbv)
NA
0.001
0.001
0.01
0.01
0.002
0.003
0.09
0.05
NA
NA
NA
NA
NA
NA
0.001
0.03
NA
NA
NA
NA
0.001
0.01
NA
NA
NA
0.001
NA
NA
0.002
NA
0.10
0.01
NA
NA
0.001
0.04
0.001
NA
0.002
0.02
NA
0.002
NA
0.002
0.02
Coefficient of
Variation (%)
NA
9.90
3.61
27.16
5.74
4.54
13.08
35.35
5.78
NA
NA
NA
NA
NA
NA
7.29
4.51
NA
NA
NA
NA
0.97
10.22
NA
NA
NA
5.21
NA
NA
4.75
NA
30.09
23.23
NA
NA
5.22
6.04
11.51
NA
4.20
6.83
NA
9.76
NA
11.23
4.32
31-15
-------
Table 31-8. VOC Method Precision: 10 Collocated Samples
for Dearborn, MI (DEMI) (Continued)
Pollutant
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Number of
Observations
9
10
10
1
10
10
Average RPD
(%)
37.56
8.71
8.55
121.13
6.85
8.84
Average
Concentration
Difference (ppbv)
0.02
0.003
0.001
0.01
0.01
0.003
Coefficient of
Variation (%)
26.56
6.16
6.05
85.65
4.84
6.25
Table 31-9 presents the method precision results from VOC duplicate analysis for GPCO.
The variability ranged from 0.71 percent (dichlorotetrafluoroethane) to 91.96 percent
(chloroprene). The average variability was 18.68 percent.
Table 31-9. VOC Method Precision: 12 Duplicate Samples
for Grand Junction, CO (GPCO)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethy Ibenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
Number of
Observations
12
12
12
2
0
12
0
1
0
12
12
12
12
1
8
12
12
0
1
0
0
0
0
12
12
Average RPD
(%)
15.33
3.98
72.87
109.32
NA
4.76
NA
74.80
NA
13.20
6.41
4.00
11.78
38.89
22.25
3.67
3.39
NA
130.06
NA
NA
NA
NA
19.96
3.88
Average
Concentration
Difference (ppbv)
0.13
0.08
0.34
0.03
NA
0.02
NA
0.01
NA
0.002
0.004
0.05
0.01
0.003
0.003
0.001
0.02
NA
0.02
NA
NA
NA
NA
0.004
0.02
Coefficient of
Variation (%)
10.84
2.82
51.52
77.30
NA
3.36
NA
52.89
NA
9.34
4.54
2.83
8.33
27.50
15.73
2.60
2.40
NA
91.96
NA
NA
NA
NA
14.11
2.74
31-16
-------
Table 31-9. VOC Method Precision: 12 Duplicate Samples
for Grand Junction, CO (GPCO) (Continued)
Pollutant
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 , 3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tort-Butyl Ether
^-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1, 1,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
w,p-Xylene
o-Xylene
Number of
Observations
0
1
0
1
0
12
0
0
0
12
0
0
12
1
12
12
9
1
12
12
12
0
12
12
0
12
0
6
12
12
12
12
1
12
12
Average RPD
(%)
NA
5.59
NA
128.68
NA
4.12
NA
NA
NA
1.01
NA
NA
3.93
9.83
63.98
40.17
55.81
72.60
6.13
9.88
27.67
NA
9.51
6.32
NA
2.03
NA
28.63
3.77
3.31
13.75
17.74
19.94
4.84
5.18
Average
Concentration
Difference (ppbv)
NA
0.001
NA
0.03
NA
0.01
NA
NA
NA
0.001
NA
NA
0.004
0.002
0.51
0.04
0.10
0.01
0.005
0.08
0.02
NA
0.01
0.08
NA
O.001
NA
0.004
0.01
0.003
0.01
0.004
0.002
0.02
0.01
Coefficient of
Variation (%)
NA
3.95
NA
90.99
NA
2.91
NA
NA
NA
0.71
NA
NA
2.78
6.95
45.24
28.40
39.47
51.33
4.33
6.99
19.57
NA
6.72
4.47
NA
1.43
NA
20.24
2.66
2.34
9.72
12.54
14.10
3.42
3.66
Table 31-10 presents the method precision results from VOC collocated analysis for
NBIL. The variability, in terms of CV, ranged from 0.76 percent (acrylonitrile) to 90.75 percent
(bromoform). The average and median CV were 31.18 percent and 26.52 percent, respectively.
11-17
-------
Table 31-10. VOC Method Precision: 12 Collocated Samples
for Northbrook, IL (NBIL)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Acrylate
Ethyl tert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
rc-Octane
Propylene
Number of
Observations
11
12
12
1
0
12
0
10
1
11
10
10
12
0
10
12
12
1
0
8
0
0
0
7
12
0
1
0
0
0
12
0
0
0
12
0
0
12
0
12
10
0
0
8
12
Average RPD
(%)
108.29
21.40
35.62
1.07
NA
21.94
NA
92.73
128.34
16.45
36.03
55.14
15.58
NA
27.03
106.28
7.32
90.60
NA
95.23
NA
NA
NA
28.95
6.10
NA
12.63
NA
NA
NA
18.55
NA
NA
NA
7.63
NA
NA
38.97
NA
66.29
57.43
NA
NA
59.39
19.41
Average
Concentration
Difference (ppbv)
0.48
0.11
0.05
O.001
NA
0.04
NA
0.39
0.03
0.002
0.01
0.01
0.02
NA
0.01
0.85
0.04
0.003
NA
0.14
NA
NA
NA
0.004
0.03
NA
0.001
NA
NA
NA
0.02
NA
NA
NA
0.001
NA
NA
0.02
NA
1.63
0.03
NA
NA
0.01
0.05
Coefficient of
Variation (%)
76.57
15.13
25.19
0.76
NA
15.52
NA
65.57
90.75
11.63
25.48
38.99
11.01
NA
19.11
75.15
5.18
64.07
NA
67.34
NA
NA
NA
20.47
4.31
NA
8.93
NA
NA
NA
13.12
NA
NA
NA
5.39
NA
NA
27.56
NA
46.88
40.61
NA
NA
41.99
13.72
31-18
-------
Table 31-10. VOC Method Precision: 12 Collocated Samples
for Northbrook, IL (NBIL) (Continued)
Pollutant
Styrene
1, 1,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
m,p-Xylene
o-Xylene
Number of
Observations
9
0
12
12
0
12
0
7
12
12
12
10
1
12
12
Average RPD
(%)
59.37
NA
30.92
46.21
NA
8.33
NA
62.58
14.24
4.92
58.43
54.62
68.24
52.70
40.50
Average
Concentration
Difference (ppbv)
0.01
NA
0.01
0.12
NA
0.002
NA
0.01
0.04
0.01
0.04
0.01
0.01
0.07
0.03
Coefficient of
Variation (%)
41.98
NA
21.86
32.68
NA
5.89
NA
44.25
10.07
3.48
41.31
38.62
48.25
37.27
28.63
Table 31-11 presents the method precision results from VOC duplicate analysis for
PXSS. The variability ranges from 0.95 percent (chloroflorm) to 118.59 percent (acetonitrile).
The median variability was 12.41 percent.
Table 31-11. VOC Method Precision: 6 Collocated Samples
for Phoenix, AZ (PXSS)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Number of
Observations
6
6
6
0
0
6
0
0
2
5
6
6
6
0
6
6
6
Average RPD
(%)
167.71
2.95
17.74
NA
NA
9.89
NA
NA
66.67
46.57
10.78
83.80
3.87
NA
12.96
1.34
3.19
Average
Concentration
Difference (ppbv)
5.31
0.04
0.17
NA
NA
0.07
NA
NA
0.004
0.004
0.003
0.08
0.001
NA
0.001
0.002
0.01
Coefficient of
Variation (%)
118.59
2.09
12.54
NA
NA
6.99
NA
NA
47.14
32.93
7.62
59.26
2.74
NA
9.16
0.95
2.26
31-19
-------
Table 31-11. VOC Method Precision: 6 Collocated Samples
for Phoenix, AZ (PXSS) (Continued)
Pollutant
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
£>-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/'s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
w-Octane
Propylene
Styrene
1, 1,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
w,£>-Xylene
o-Xylene
Number of
Observations
0
0
4
0
0
4
6
6
0
0
0
0
0
6
0
1
1
6
0
0
6
0
6
6
0
0
6
6
6
0
6
6
4
6
0
2
6
6
6
6
o
5
6
6
Average RPD
(%)
NA
NA
13.57
NA
NA
52.27
17.37
1.60
NA
NA
NA
NA
NA
18.99
NA
43.74
11.97
34.57
NA
NA
18.73
NA
39.10
19.97
NA
NA
17.02
10.30
21.83
NA
13.39
6.72
94.02
25.02
NA
14.29
5.53
6.62
18.89
18.57
60.56
21.16
15.39
Average
Concentration
Difference (ppbv)
NA
NA
0.002
NA
NA
0.004
0.01
0.01
NA
NA
NA
NA
NA
0.05
NA
0.004
0.001
0.002
NA
NA
0.04
NA
0.64
0.03
NA
NA
0.01
0.12
0.01
NA
0.01
0.14
0.01
0.003
NA
0.002
0.01
0.002
0.02
0.01
0.005
0.12
0.04
Coefficient of
Variation (%)
NA
NA
9.60
NA
NA
36.96
12.28
1.13
NA
NA
NA
NA
NA
13.43
NA
30.93
8.46
24.45
NA
NA
13.25
NA
27.65
14.12
NA
NA
12.03
7.28
15.44
NA
9.46
4.75
66.48
17.69
NA
10.10
3.91
4.68
13.36
13.13
42.83
14.96
10.89
31-20
-------
Table 31-12 presents the method precision results from VOC duplicate analysis for
S4MO. The variability ranged from 10.89 percent (dichlorotetrafluoroethane) to 72.14 percent
(trichloroethylene), with a median CV of 23.72 percent.
Table 31-12. VOC Method Precision: 12 Duplicate Samples
for St. Louis, MO (S4MO)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Number of
Observations
11
12
11
0
0
12
0
0
0
11
11
11
11
0
7
11
12
0
0
0
0
0
0
9
12
0
0
0
0
0
11
0
0
0
11
0
0
12
0
Average RPD
(%)
75.39
34.43
67.23
NA
NA
30.28
NA
NA
NA
25.78
25.62
38.09
36.02
NA
54.03
33.54
36.17
NA
NA
NA
NA
NA
NA
22.77
37.37
NA
NA
NA
NA
NA
36.47
NA
NA
NA
15.40
NA
NA
29.57
NA
Average
Concentration
Difference (ppbv)
0.37
0.11
0.21
NA
NA
0.04
NA
NA
NA
0.01
0.01
0.09
0.02
NA
0.02
0.01
0.10
NA
NA
NA
NA
NA
NA
0.003
0.10
NA
NA
NA
NA
NA
0.02
NA
NA
NA
0.002
NA
NA
0.01
NA
Coefficient of
Variation (%)
53.31
24.34
47.54
NA
NA
21.41
NA
NA
NA
18.23
18.11
26.94
25.47
NA
38.20
23.72
25.57
NA
NA
NA
NA
NA
NA
16.10
26.43
NA
NA
NA
NA
NA
25.79
NA
NA
NA
10.89
NA
NA
20.91
NA
31-21
-------
Table 31-12. VOC Method Precision: 12 Duplicate Samples
for St. Louis, MO (S4MO) (Continued)
Pollutant
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl ter/-Butyl Ether
w-Octane
Propylene
Styrene
1, 1,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Number of
Observations
11
10
0
1
11
12
9
0
11
12
0
12
0
1
11
12
12
10
1
12
12
Average RPD
(%)
41.08
41.77
NA
80.12
41.58
33.06
29.22
NA
16.53
28.07
NA
21.59
NA
102.02
36.82
17.74
24.75
25.40
83.82
32.38
29.02
Average
Concentration
Difference (ppbv)
0.10
0.02
NA
0.003
0.01
0.08
0.004
NA
0.004
0.10
NA
0.003
NA
0.02
0.05
0.02
0.01
0.002
0.01
0.02
0.01
Coefficient of
Variation (%)
29.05
29.53
NA
56.66
29.40
23.38
20.66
NA
11.69
19.85
NA
15.27
NA
72.14
26.03
12.55
17.50
17.96
59.27
22.89
20.52
The method precision results from the VOC collocated analysis for SEWA are shown in
Table 31-13. In terms of CV, the variability ranged from 3.85 percent for chloromethane to
99.37 percent for dichlorotetrafluoroethane.
Table 31-13. VOC Method Precision: 14 Collocated Samples
for Seattle, WA (SEWA)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
ter/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
Number of
Observations
10
14
14
1
0
14
0
0
0
12
Average RPD
(%)
17.06
9.60
54.91
27.52
NA
11.19
NA
NA
NA
9.02
Average
Concentration
Difference (ppbv)
0.02
0.07
0.10
0.003
NA
0.03
NA
NA
NA
0.001
Coefficient of
Variation (%)
12.06
6.79
38.83
19.46
NA
7.91
NA
NA
NA
6.38
31-22
-------
Table 31-13. VOC Method Precision: 14 Collocated Samples
for Seattle, WA (SEWA) (Continued)
Pollutant
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
£>-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
^-Octane
Propylene
Styrene
1, 1,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
Number of
Observations
14
9
14
0
12
14
14
0
0
0
0
0
0
9
14
1
0
0
0
5
14
0
0
0
14
0
0
14
0
14
13
0
0
14
14
14
0
12
14
0
14
1
9
14
14
Average RPD
(%)
10.75
35.29
9.21
NA
66.91
45.83
5.45
NA
NA
NA
NA
NA
NA
15.17
7.00
68.61
NA
NA
NA
25.62
9.36
NA
NA
NA
140.53
NA
NA
13.37
NA
73.86
26.14
NA
NA
16.34
18.65
80.77
NA
18.08
17.07
NA
13.67
72.49
43.02
6.84
9.74
Average
Concentration
Difference (ppbv)
0.01
0.01
0.01
NA
0.01
0.01
0.03
NA
NA
NA
NA
NA
NA
0.001
0.03
0.004
NA
NA
NA
0.004
0.01
NA
NA
NA
0.18
NA
NA
0.01
NA
0.24
0.01
NA
NA
0.003
0.07
0.04
NA
0.003
0.07
NA
0.002
0.005
0.01
0.02
0.01
Coefficient of
Variation (%)
7.60
24.95
6.52
NA
47.31
32.41
3.85
NA
NA
NA
NA
NA
NA
10.72
4.95
48.52
NA
NA
NA
18.12
6.62
NA
NA
NA
99.37
NA
NA
9.45
NA
52.23
18.49
NA
NA
11.55
13.19
57.11
NA
12.79
12.07
NA
9.66
51.26
30.42
4.84
6.89
31-23
-------
Table 31-13. VOC Method Precision: 14 Collocated Samples
for Seattle, WA (SEWA) (Continued)
Pollutant
1,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
m,p-Xylene
o-Xylene
Number of
Observations
14
14
0
14
14
Average RPD
(%)
16.01
14.21
NA
17.92
14.05
Average
Concentration
Difference (ppbv)
0.01
0.003
NA
0.02
0.01
Coefficient of
Variation (%)
11.32
10.05
NA
12.67
9.94
Table 31-14 presents the average CV per pollutant, per pollutant per site, per site, and the
overall average CV for all UATMP and NATTS sites sampling VOC. The results from duplicate
and collocated samples show low- to high-level variability among sites, ranging from an average
CV of 7.44 percent at CANJ to 50.50 percent at CAMS 85. The average pollutant-specific CV
ranged from 5.29 percent (dichlorodifluoromethane) to 117.28 percent (1,1-dichloroethene). The
overall average was 28.25 percent. This is higher than the program DQO of 15 percent overall
CV per site.
11-24
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
Average
37.53
9.64
25.98
30.39
41.90
10.97
NA
39.78
48.84
13.78
14.93
23.64
10.12
9.91
24.47
16.89
5.91
36.33
83.91
52.40
NA
41.53
40.83
20.47
5.29
48.52
Barceloneta, PR
(BAPR)
12.74
13.01
27.06
61.22
NA
8.69
NA
NA
NA
33.09
7.60
10.05
7.98
NA
50.50
8.88
7.30
NA
NA
NA
NA
NA
NA
8.73
9.31
NA
Bountiful, UT
(BTUT)
29.50
4.37
22.65
NA
NA
5.30
NA
NA
NA
5.52
8.51
23.41
11.16
NA
5.46
21.57
1.82
NA
NA
NA
NA
NA
NA
15.69
2.59
NA
Deer Park , TX
(CAMS 35)
15.46
9.08
37.99
19.64
19.99
7.25
NA
0.87
38.42
11.14
14.53
37.61
4.50
3.76
25.34
14.10
4.89
NA
73.10
78.18
NA
NA
46.97
17.60
3.20
NA
Karnack , TX
(CAMS 85)
NA
29.06
12.86
NA
NA
23.57
NA
NA
NA
NA
90.00
NA
7.44
NA
47.14
28.28
15.43
NA
NA
NA
NA
NA
NA
NA
NA
NA
Camden, NJ
(CANJ)
12.90
2.98
13.01
NA
63.94
2.12
NA
NA
NA
12.08
3.15
2.79
18.63
NA
22.31
7.49
3.65
NA
NA
NA
NA
NA
NA
5.02
2.98
NA
Chester, NJ
(CHNJ)
18.97
5.81
33.43
15.23
NA
5.75
NA
NA
NA
10.10
14.37
5.19
28.99
NA
26.30
27.88
1.33
NA
NA
NA
NA
NA
NA
40.22
3.01
NA
tt
O ^
C PH
o W
^Z
& B
2.13
4.00
8.80
NA
19.78
13.65
NA
NA
NA
7.78
14.52
7.70
7.25
3.82
5.25
4.16
3.87
NA
NA
15.71
NA
NA
38.57
23.82
5.26
NA
Custer, SD
(CUSD)
20.47
6.02
17.68
15.33
NA
7.44
NA
NA
NA
18.76
15.38
4.17
5.07
NA
4.62
11.08
3.07
NA
NA
NA
NA
NA
NA
4.56
2.44
NA
Dearborn, MI
(DEMI)
14.68
4.56
29.65
NA
NA
4.51
NA
NA
NA
9.90
3.61
27.16
5.74
4.54
13.08
35.35
5.78
NA
NA
NA
NA
NA
NA
7.29
4.51
NA
Elizabeth, NJ
(ELNJ)
43.73
17.70
33.13
NA
NA
12.04
NA
NA
NA
13.14
13.34
10.08
15.24
NA
47.66
5.50
9.32
NA
NA
NA
NA
NA
NA
11.76
8.91
NA
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
Pollutant
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
^-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
Average
27.72
117.28
90.99
9.54
14.67
20.08
30.93
8.46
13.91
NA
NA
13.45
19.51
27.61
26.72
30.52
31.03
17.18
17.47
22.28
84.94
19.52
16.41
45.91
10.53
39.41
26.88
Barceloneta, PR
(BAPR)
NA
NA
NA
NA
6.27
NA
NA
NA
7.09
NA
NA
6.34
NA
16.81
NA
NA
4.78
14.22
11.35
22.37
NA
38.72
7.42
NA
7.02
NA
9.36
Bountiful, UT
(BTUT)
NA
NA
NA
NA
3.64
20.08
NA
NA
3.77
NA
NA
5.78
NA
14.12
11.30
NA
NA
4.90
4.84
15.44
NA
8.75
7.24
NA
2.53
NA
3.82
Deer Park , TX
(CAMS 35)
14.57
NA
NA
NA
10.41
NA
NA
NA
7.78
NA
NA
11.04
NA
21.81
29.00
37.66
19.02
17.73
11.63
14.89
NA
19.25
12.18
NA
5.84
NA
12.48
Karnack , TX
(CAMS 85)
123.74
NA
NA
NA
47.14
NA
NA
NA
47.14
NA
NA
38.57
NA
11.16
NA
NA
117.24
22.33
134.52
20.20
NA
125.71
7.44
NA
47.14
NA
NA
Camden, NJ
(CANJ)
NA
NA
NA
NA
7.36
NA
NA
NA
0.91
NA
NA
3.73
NA
6.74
6.59
NA
0.00
2.07
2.19
14.41
NA
2.55
4.43
NA
1.89
NA
5.34
Chester, NJ
(CHNJ)
NA
NA
NA
NA
6.03
NA
NA
NA
2.82
NA
NA
10.05
32.07
46.31
18.55
NA
NA
27.35
3.93
27.45
NA
28.35
10.05
25.34
6.38
NA
38.57
tt
?£
P
£B
NA
NA
NA
NA
7.75
NA
NA
NA
24.42
NA
NA
8.83
NA
26.22
16.88
23.22
NA
8.66
19.07
10.70
NA
21.39
15.02
NA
14.07
NA
18.39
Custer, SD
(CUSD)
NA
NA
NA
NA
5.76
NA
NA
NA
4.21
NA
NA
12.31
NA
36.94
52.69
NA
NA
11.13
8.93
16.33
NA
9.86
8.24
NA
7.69
NA
NA
Dearborn, MI
(DEMI)
NA
NA
NA
0.97
10.22
NA
NA
NA
5.21
NA
NA
4.75
NA
30.09
23.23
NA
NA
5.22
6.04
11.51
NA
4.20
6.83
NA
9.76
NA
11.23
Elizabeth, NJ
(ELNJ)
3.95
117.28
NA
NA
11.67
NA
NA
NA
18.86
NA
NA
10.86
NA
23.25
14.54
NA
14.21
9.02
10.48
42.95
NA
10.22
11.03
NA
15.03
NA
28.28
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
Pollutant
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
m,p-Xylene
o-Xylene
Average
Average
6.31
7.31
14.35
12.59
37.29
14.94
13.18
28.25
a.
sS
a
•~ C^
u CH
*" ^
M B
8.18
8.43
9.50
4.81
14.10
7.74
4.88
14.41
H
^)
^•v
"3 _
SB p
a P
S H
M B
2.74
1.86
6.17
6.37
23.12
4.78
4.53
9. 50
B
" /— s
•S £
«• 22
•— S
oj -^J
P B
3.24
3.60
16.63
19.20
10.92
12.75
11.82
18.77
X
^ 00
y 22
a S
c3 ^
W B
NA
NA
28.28
NA
118.72
30.30
38.57
50.50
I"S
Z
•V
5 Q
"a ^
a •<*
U B
3.22
1.79
4.28
2.18
5.24
1.64
3.50
7.44
^K
Z
4J ^
•s z
o> PH
u B
3.56
3.52
16.79
17.05
NA
9.42
9.81
17.06
O ^
lT &H
o W
S* Z
&H B
5.28
5.69
10.59
3.77
7.05
9.86
9.39
72.23
P
'- P
5« ^
u B
4.83
2.33
9.13
8.67
35.36
22.76
8.48
72.55
HH
^
s^
0 h?
•s s
~ H
p S
4.32
26.56
6.16
6.05
85.65
4.84
6.25
72. 93
Z
•N
O ^*^
"i Z
.S nJ
S S
10.02
8.47
8.30
3.38
NA
10.34
8.05
18.58
OJ
to
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
Average
37.53
9.64
25.98
30.39
41.90
10.97
NA
39.78
48.84
13.78
14.93
23.64
10.12
9.91
24.47
16.89
5.91
36.33
83.91
52.40
NA
41.53
40.83
20.47
5.29
48.52
Grand Junction, CO
(GPCO)
10.84
2.82
51.52
77.30
NA
3.36
NA
52.89
NA
9.34
4.54
2.83
8.33
27.50
15.73
2.60
2.40
NA
91.96
NA
NA
NA
NA
14.11
2.74
NA
Gulfport, MS
(GPMS)
13.99
3.26
22.51
9.78
63.94
10.66
NA
NA
NA
28.53
21.94
6.86
5.94
NA
10.72
16.56
3.98
NA
NA
NA
NA
NA
NA
11.33
1.82
NA
Loudon, TN
(LDTN)
39.39
15.41
26.74
NA
NA
21.73
NA
NA
11.47
9.11
23.36
5.53
14.73
NA
22.63
6.53
3.66
NA
50.74
65.39
41.53
NA
17.84
7.16
NA
Loudon, TN
(MSTN)
24.25
2.72
34.42
NA
63.94
9.20
NA
NA
NA
8.33
8.63
6.80
5.42
NA
18.55
9.73
4.38
8.59
NA
NA
NA
NA
NA
43.31
3.76
NA
Northbrook, IL
(NBIL)
76.57
15.13
25.19
0.76
NA
15.52
NA
65.57
90.75
11.63
25.48
38.99
11.01
NA
19.11
75.15
5.18
64.07
NA
67.34
NA
NA
NA
20.47
4.31
NA
New Brunswick, NJ
(NBNJ)
8.16
14.36
12.84
39.41
NA
7.29
NA
NA
NA
7.18
5.29
4.54
15.84
NA
24.36
8.30
3.69
NA
NA
NA
NA
NA
NA
22.60
4.60
NA
Phoenix, AZ
(PXSS)
118.59
2.09
12.54
NA
NA
6.99
NA
NA
47.14
32.93
7.62
59.26
2.74
NA
9.16
0.95
2.26
NA
NA
9.60
NA
NA
36.96
12.28
1.13
NA
O
S
j£
'3 o
.si
. •*
££
53.31
24.34
47.54
NA
NA
21.41
NA
NA
NA
18.23
18.11
26.94
25.47
NA
38.20
23.72
25.57
NA
NA
NA
NA
NA
NA
16.10
26.43
NA
Seattle, WA
(SEWA)
12.06
6.79
38.83
19.46
NA
7.91
NA
NA
NA
6.38
7.60
24.95
6.52
NA
47.31
32.41
3.85
NA
NA
NA
NA
NA
NA
10.72
4.95
48.52
0
!/5
%
"3
*0
Is
££
10.78
15.26
27.69
NA
NA
8.56
NA
NA
NA
36.49
23.33
9.52
6.72
NA
8.15
3.37
3.17
NA
NA
NA
NA
41.53
NA
NA
2.38
NA
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
Pollutant
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/'s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fert-Butyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
Average
27.72
117.28
90.99
9.54
14.67
20.08
30.93
8.46
13.91
NA
NA
13. 45
19.51
27.61
26.72
30.52
31.03
17.18
17.47
22.28
84.94
19.52
16.41
45.91
10.53
39.41
26.88
Grand Junction, CO
(GPCO)
3.95
NA
90.99
NA
2.91
NA
NA
NA
0.71
NA
NA
2.78
6.95
45.24
28.40
39.47
51.33
4.33
6.99
19.57
NA
6.72
4.47
NA
1.43
NA
20.24
Gulfport, MS
(GPMS)
NA
NA
NA
NA
16.46
NA
NA
NA
3.63
NA
NA
10.20
NA
46.31
50.78
NA
30.84
14.70
34.49
14.41
NA
6.66
27.40
NA
6.03
4.68
NA
Loudon, TN
(LDTN)
NA
NA
NA
NA
32.17
NA
NA
NA
4.86
NA
NA
10.61
NA
23.07
36.23
43.59
NA
37.12
19.84
7.13
NA
7.88
21.54
NA
5.35
NA
32.57
Loudon, TN
(MSTN)
NA
NA
NA
NA
18.54
NA
NA
NA
13.95
NA
NA
11.71
NA
25.57
28.72
NA
NA
26.86
10.15
6.56
84.94
20.52
37.99
NA
6.22
NA
38.41
Northbrook, IL
(NBIL)
8.93
NA
NA
NA
13.12
NA
NA
NA
5.39
NA
NA
27.56
NA
46.88
40.61
NA
NA
41.99
13.72
41.98
NA
21.86
32.68
NA
5.89
NA
44.25
New Brunswick, NJ
(NBNJ)
9.85
NA
NA
NA
21.94
NA
NA
NA
18.02
NA
NA
7.58
NA
32.57
19.49
NA
NA
6.36
2.26
7.04
NA
14.22
17.15
NA
5.14
NA
NA
Phoenix, AZ
(PXSS)
NA
NA
NA
NA
13.43
NA
30.93
8.46
24.45
NA
NA
13.25
NA
27.65
14.12
NA
NA
12.03
7.28
15.44
NA
9.46
4.75
66.48
17.69
NA
10.10
O
s
•V
.2 ^
g °
j£
*i
NA
NA
NA
NA
25.79
NA
NA
NA
10.89
NA
NA
20.91
NA
29.05
29.53
NA
56.66
29.40
23.38
20.66
NA
11.69
19.85
NA
15.27
NA
72.14
Seattle, WA
(SEWA)
NA
NA
NA
18.12
6.62
NA
NA
NA
99.37
NA
NA
9.45
NA
52.23
18.49
NA
NA
11.55
13.19
57.11
NA
12.79
12.07
NA
9.66
51.26
30.42
0
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
Pollutant
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Average
Average
6.31
7.31
14.35
12.59
37.29
14.94
13.18
28.25
O
u
.0
o
a
s ^
"a U
2.66
2.34
9.72
12.54
14.10
3.42
3.66
18.68
*
•w ^^^
g,g
|s
2.73
2.03
16.74
11.71
NA
14.78
15.23
76.52
Z
H
c o
•§ H
s a
7.86
3.54
11.18
13.84
50.81
9.10
10.12
20.85
Z
H
c 7-
0 £
•a H
II
4.51
3.91
17.20
21.95
NA
15.09
17.32
19.48
hJ
HH
^
0
s
* '"T"
a d
ig
z o
10.07
3.48
41.31
38.62
48.25
37.27
28.63
31.18
^
Z
'?
=
P5 ^
z S-
3.76
23.56
13.01
11.90
NA
9.05
8.74
72.82
SI
•V
c ^^
S C/5
is
3.91
4.68
13.36
13.13
42.83
14.96
10.89
19.51
O
•V
%
s o
"*^ ZJT)
Zfl ^^s
26.03
12.55
17.50
17.96
59.27
22.89
20.52
27.49
<
*
C |:
S w
4.84
6.89
11.32
10.05
NA
12.67
9.94
21.04
a
13
^ &
•^ ^O
^^ ^^
1.85
2.42
8.23
7.37
NA
6.90
5.21
14.14
oo
o
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon Bisulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
Average
37.53
9.64
25.98
30.39
41.90
10.97
NA
39.78
48.84
13.78
14.93
23.64
10.12
9.91
24.47
16.89
5.91
36.33
83.91
52.40
NA
41.53
40.83
20.47
5.29
48.52
&
a.
§
Z&
£ sa
29.57
4.19
21.48
NA
NA
4.90
NA
NA
NA
10.88
1.22
13.22
9.73
NA
NA
23.57
6.11
NA
NA
NA
NA
NA
NA
10.56
6.55
NA
Schiller Park IL
(SPIL)
123.00
9.77
56.18
NA
NA
23.45
NA
NA
NA
10.74
18.73
118.45
3.60
NA
32.91
26.15
7.21
NA
85.85
NA
NA
NA
NA
37.67
8.26
NA
tt
°£
ef O
•io
3b
71.87
3.73
9.03
NA
NA
5.82
NA
NA
56.44
6.14
2.77
47.56
2.70
NA
27.08
7.02
2.42
NA
117.87
NA
NA
NA
NA
24.05
1.40
NA
tt
O <-^
- W
go
•3 ^
nb
70.66
15.91
17.65
21.43
19.78
22.30
NA
NA
NA
6.10
7.83
33.85
8.95
NA
43.65
NA
3.42
NA
NA
78.18
NA
NA
NA
55.56
3.21
NA
Tulsa, OK
(TUOK)
49.15
9.79
17.32
54.72
NA
18.81
NA
NA
NA
10.52
21.82
59.30
13.20
NA
39.80
2.28
11.63
NA
NA
NA
NA
NA
NA
47.10
4.88
NA
!/5
If
0. LJ
E?b
55.49
8.40
17.63
NA
NA
6.94
NA
NA
NA
10.43
4.89
4.24
10.23
NA
6.80
19.52
8.19
NA
NA
NA
NA
NA
NA
12.98
6.38
NA
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
oo
to
Pollutant
1,2-Dichloroethane
1, 1-Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 , 3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tort-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fert-Butyl Ether
w-Octane
Propylene
Styrene
1, 1,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
Average
27.72
117.28
90.99
9.54
14.67
20.08
30.93
8.46
13.91
NA
NA
13.45
19.51
27.61
26.72
30.52
31.03
17.18
17.47
22.28
84.94
19.52
16.41
45.91
10.53
39.41
26.88
San Juan, PR
(SJPR)
NA
NA
NA
NA
17.30
NA
NA
NA
9.43
NA
NA
11.48
NA
7.79
5.83
NA
1.16
7.87
3.86
5.43
NA
6.61
9.18
NA
13.82
NA
NA
Schiller Park IL
(SPIL)
NA
NA
NA
NA
43.58
NA
NA
NA
4.75
NA
NA
19.83
NA
30.07
37.89
NA
NA
26.20
22.65
50.98
NA
32.13
22.22
NA
19.82
NA
45.34
Tulsa, OK
(TOOK)
NA
NA
NA
NA
4.28
NA
NA
NA
8.04
NA
NA
5.37
NA
7.95
9.04
8.68
17.14
9.15
3.96
11.37
NA
24.76
7.09
NA
3.97
NA
10.24
tt
°8
sS Q
UK >*
•3 f
Sb
3.95
NA
NA
NA
10.13
NA
NA
NA
2.81
NA
NA
36.58
NA
36.42
60.26
NA
43.29
8.49
8.68
62.47
NA
15.48
54.68
NA
10.54
NA
42.89
tt
°$
Ig
£b
11.38
NA
NA
NA
20.45
NA
NA
NA
9.05
NA
NA
19.66
NA
31.30
32.08
NA
16.64
33.60
31.86
17.19
NA
5.35
48.53
NA
5.33
NA
54.13
!/5
s
it
H=l
63.80
NA
NA
NA
9.72
NA
NA
NA
18.31
NA
NA
14.31
NA
17.83
34.44
NA
NA
31.41
10.19
27.57
NA
23.97
6.44
NA
12.13
62.28
9.36
-------
Table 31-14. VOC Method Precision: Coefficient of Variation for all Duplicate and Collocated Samples by Site (Continued)
OJ
oo
Pollutant
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
w,p-Xylene
o-Xylene
Average
Average
6.31
7.31
14.35
12.59
37.29
14.94
13.18
28.25
a.
=
£ &
4.86
9.96
1.42
3.03
NA
11.00
8.18
9.34
-J
-i
sS
&H
— J*
17.89
6.09
18.67
13.81
NA
24.01
21.28
31.85
O /~'
cs O
-ao
2.19
20.59
7.04
5.07
29.01
7.25
8.51
76.57
O
JO
4.40
3.06
34.67
23.89
28.28
51.99
33.98
27.37
O O
cs O
~ P
7.79
9.01
28.77
24.09
24.01
19.72
21.78
23.77
!/5
S ^
"S S
ap
7.02
6.35
7.01
14.32
NA
13.97
13.35
17.45
-------
31.1.2 SNMOC Method Precision
The SNMOC method precision for duplicate and collocated samples is presented in
Table 31-15. The average concentration differences observed for duplicate and collocated
sample analysis ranged from 0.003 ppbC (c/s-2-hexene) to 29.32 ppbC (TNMOC). The variation
ranged from 1.37 percent (tmns-2-hexene) to 91.12 percent (4-methyl-l-pentene).
Table 31-15. SNMOC Method Precision: 60 Duplicate and Collocated Samples
Pollutant
Acetylene
Benzene
1,3 -Butadiene
rc-Butane
c/s-2-Butene
fraws-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
rc-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3-Dimethylbutane
2,3-Dimethylpentane
2,4-Dimethylpentane
rc-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
^-Heptane
1-Heptene
rc-Hexane
1-Hexene
c/s-2-Hexene
fraws-2-Hexene
Isobutane
lsobutene/1 -Butene
Isopentane
Number of
Observations
60
60
38
58
52
58
60
60
11
58
0
38
15
55
56
58
57
54
29
60
60
0
60
56
44
54
60
49
59
50
2
2
60
42
50
Average RPD
(%)
8.68
18.84
27.80
6.83
23.58
22.36
12.96
16.91
54.05
26.16
NA
46.32
68.12
22.43
12.33
19.27
15.31
46.71
74.26
9.53
19.41
NA
15.92
26.75
41.53
40.04
8.11
32.43
12.24
41.20
2.32
1.94
9.16
20.85
23.51
Average
Concentration
Difference (ppbC)
0.17
0.28
0.03
0.28
0.03
0.05
0.04
0.05
0.14
0.22
NA
0.13
0.18
0.05
0.05
0.06
0.04
0.17
0.24
0.87
0.10
NA
0.34
0.10
0.13
0.38
0.04
0.06
0.12
0.07
0.003
0.004
0.21
0.30
2.68
Coefficient of
Variation (%)
6.14
13.32
19.66
4.83
16.67
15.81
9.17
11.95
38.22
18.50
NA
32.75
48.17
15.86
8.72
13.62
10.82
33.03
52.51
6.74
13.72
NA
11.26
18.92
29.37
28.31
5.73
22.93
8.66
29.13
1.64
1.37
6.47
14.75
16.63
31-34
-------
Table 31-15. SNMOC Method Precision: 60 Duplicate and Collocated Samples (Continued)
Pollutant
Isoprene
Isopropylbenzene
2-Methyl-l-butene
2-Methyl-2-butene
3 -Methyl- 1 -butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3 -Methy Ihexane
3-Methylpentane
2-Methylpentane
4-Methyl-l-pentene
2-Methyl-l-pentene
^7-Nonane
1-Nonene
rc-Octane
1-Octene
rc-Pentane
1-Pentene
c/s-2-Pentene
fra«5-2-Pentene
a-Pinene
&-Pinene
Propane
w-Propylbenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1 ,2,3 -Trimethylbenzene
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3,4-Trimethylpentane
rc-Undecane
1-Undecene
m -Xy lene/^-Xy lene
o-Xylene
Number of
Observations
52
24
52
39
6
55
60
42
49
45
60
60
59
1
9
59
27
60
32
60
58
34
50
47
13
60
51
60
0
19
60
60
60
8
0
44
60
43
38
60
59
59
16
60
60
Average RPD
(%)
19.34
40.01
15.76
34.16
9.58
17.26
8.82
43.70
14.46
37.18
19.10
11.81
32.46
128.86
33.59
23.61
31.67
11.37
46.46
10.45
28.11
39.40
15.71
56.77
88.10
6.58
38.25
21.03
NA
38.43
11.43
20.38
17.83
87.69
NA
29.99
27.23
30.60
43.84
12.04
20.96
34.92
77.84
21.21
14.75
Average
Concentration
Difference (ppbC)
0.15
0.81
0.07
0.09
0.07
0.05
0.07
0.06
0.02
0.17
0.10
0.08
0.37
0.19
0.10
0.12
0.05
0.03
0.07
0.33
0.31
0.07
0.03
0.33
0.69
0.55
0.07
0.30
NA
0.11
8.44
29.32
1.05
0.20
NA
0.05
0.15
0.06
0.08
0.15
0.07
0.21
0.09
0.54
0.08
Coefficient of
Variation (%)
13.67
28.29
11.14
24.15
6.77
12.21
7.27
30.90
10.23
26.29
13.51
8.28
22.95
91.12
23.75
16.70
20.17
8.04
32.85
7.39
19.87
27.86
11.11
40.14
62.30
4.65
27.05
14.87
NA
27.18
8.08
14.41
12.61
62.00
NA
21.21
19.25
21.63
31.00
8.19
14.82
24.69
55.04
15.00
10.43
31-35
-------
Table 31-16 presents the method precision for duplicate SNMOC samples. The variation
ranged from 1.37 (trans-2-hexQno) to 91.12 (4-methyl-l-pentene), with an average CV of 18.23
percent and a median CV of 13.34 percent. For SNMOC, there was only one collocated site,
NBIL. The SNMOC precision data for the collocated samples at NBIL is shown in Table 31-18.
Table 31-16. SNMOC Method Precision: 48 Duplicate Samples
Pollutant
Acetylene
Benzene
1,3 -Butadiene
w-Butane
c/s-2 -Butene
trans-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
w-Decane
1-Decene
OT-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
w-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
w-Heptane
1-Heptene
w-Hexane
1-Hexene
c/s-2-Hexene
trans-2-Hexene
Isobutane
lsobutene/1 -Butene
Isopentane
Isoprene
Isopropylbenzene
2-Methyl- 1 -butene
Number of
Observations
48
48
33
46
45
46
48
48
7
46
0
28
11
44
44
46
45
43
22
48
48
0
48
44
36
43
48
40
47
43
2
2
48
35
38
45
20
41
Average RPD
(%)
7.06
16.75
25.57
3.62
19.40
22.65
9.72
16.28
47.41
15.69
NA
46.92
52.50
17.12
7.08
15.14
12.22
43.24
83.46
3.12
14.19
NA
15.70
20.43
36.52
33.04
6.08
31.62
12.78
36.08
2.32
1.94
4.60
16.56
22.99
13.54
35.80
15.08
Average
Concentration
Difference (ppbC)
0.15
0.26
0.03
0.16
0.03
0.05
0.04
0.05
0.13
0.06
NA
0.12
0.19
0.04
0.03
0.04
0.03
0.12
0.27
0.20
0.07
NA
0.34
0.06
0.09
0.43
0.03
0.06
0.13
0.07
0.003
0.004
0.12
0.31
2.83
0.06
1.00
0.05
Coefficient of
Variation (%)
4.99
11.85
18.08
2.56
13.72
16.02
6.88
11.51
33.53
11.09
NA
33.18
37.12
12.11
5.01
10.71
8.64
30.57
59.02
2.20
10.04
NA
11.10
14.45
25.82
23.36
4.30
22.36
9.04
25.51
1.64
1.37
3.25
11.71
16.26
9.57
25.32
10.66
31-36
-------
Table 31-16. SNMOC Method Precision: 48 Duplicate Samples (Continued)
Pollutant
2-Methyl-2-butene
3 -Methyl- 1 -butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2 -Methy Ihexane
3-Methylhexane
3-Methylpentane
2-Methylpentane
4-Methyl- 1 -pentene
2-Methyl- 1 -pentene
w-Nonane
1-Nonene
w-Octane
1-Octene
w-Pentane
1 -Pentene
c/s-2-Pentene
trans-2-Pentene
a-Pinene
&-Pinene
Propane
w-Propylbenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1 ,2,3 -Trimethylbenzene
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3,4-Trimethylpentane
rc-Undecane
1-Undecene
m -Xy lene/^-Xy lene
o-Xylene
Number of
Observations
32
6
43
48
33
39
35
48
48
47
1
9
47
21
48
27
48
46
29
41
36
10
48
40
48
0
15
48
48
48
7
0
36
48
35
29
48
47
48
13
48
48
Average RPD
(%)
33.76
9.58
16.63
6.84
43.77
12.86
39.53
18.32
8.71
33.68
128.86
33.59
13.12
22.33
8.61
38.38
8.39
23.39
35.77
14.48
59.62
75.54
3.09
31.82
22.84
NA
32.53
9.69
16.83
13.40
73.69
NA
28.90
19.50
29.96
46.96
8.77
21.63
27.14
78.89
16.27
8.26
Average
Concentration
Difference (ppbC)
0.09
0.07
0.05
0.05
0.07
0.02
0.18
0.08
0.07
0.35
0.19
0.10
0.03
0.03
0.03
0.06
0.33
0.31
0.08
0.03
0.33
0.71
0.39
0.05
0.34
NA
0.10
7.58
26.16
1.14
0.17
NA
0.04
0.09
0.05
0.09
0.06
0.07
0.11
0.08
0.54
0.04
Coefficient of
Variation (%)
23.87
6.77
11.76
5.62
30.95
9.09
27.95
12.95
6.42
23.81
91.12
23.75
9.28
14.78
6.09
27.14
5.93
16.54
25.29
10.24
42.16
53.42
2.19
22.50
16.15
NA
23.00
6.85
11.90
9.48
52.11
NA
20.44
13.79
21.18
33.21
5.30
15.30
19.19
55.78
11.50
5.84
Due to the focus on QA for the NATTS program, Tables 31-17 and 31-18 present the
SNMOC method precision for NATTS sites (BTUT and NBIL, respectively). Shaded rows
31-37
-------
present results for the NATTS core compounds. Table 31-17 shows that the SNMOC variation
for the duplicate samples at BTUT ranged from 0.61 percent (acetylene) to 91.12 percent (4-
methyl-1-pentene). The average CV was 10.84 percent, which is within the program DQO.
Table 31-18 shows the SNMOC precision for the collocated samples at NBIL. The variability
ranged from 7.14 percent for w-hexane to 91.69 percent for w-tridecane.
Table 31-17. SNMOC Method Precision: 12 Duplicate Samples
for Bountiful, UT (BTUT)
Pollutant
Acetylene
Benzene
1,3 -Butadiene
rc-Butane
c/s-2-Butene
fraws-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
rc-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethy Ibutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
rc-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
^-Heptane
1-Heptene
rc-Hexane
1-Hexene
c/s-2-Hexene
fraws-2-Hexene
Isobutane
lsobutene/1 -Butene
Number of
Observations
12
12
12
12
12
12
12
12
2
12
0
6
6
12
12
12
12
12
8
12
12
0
12
12
12
12
12
11
12
12
2
2
12
12
Average RPD
(%)
0.86
7.21
4.80
1.29
4.82
10.82
4.78
8.22
27.00
6.68
NA
28.62
32.54
5.57
3.72
5.76
3.79
29.80
57.67
1.13
9.39
NA
5.02
11.23
23.92
8.49
3.38
49.07
3.31
18.06
2.32
1.94
1.42
8.52
Average
Concentration
Difference (ppbC)
0.05
0.17
0.01
0.33
0.02
0.03
0.04
0.03
0.10
0.07
NA
0.09
0.16
0.02
0.05
0.05
0.03
0.10
0.13
0.13
0.09
NA
0.27
0.09
0.09
0.03
0.06
0.14
0.20
0.03
0.003
0.004
0.21
0.20
Coefficient of
Variation (%)
0.61
5.10
3.40
0.91
3.41
7.65
3.38
5.82
19.09
4.72
NA
20.24
23.01
3.94
2.63
4.07
2.68
21.07
40.78
0.80
6.64
NA
3.55
7.94
16.91
6.00
2.39
34.70
2.34
12.77
1.64
1.37
1.00
6.02
31-38
-------
Table 31-17. SNMOC Method Precision: 12 Duplicate Samples
for Bountiful, UT (BTUT) (Continued)
Pollutant
Isopentane
Isoprene
Isopropylbenzene
2-Methyl-l-butene
2-Methyl-2-butene
3-Methyl-l-butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3-Methylhexane
3-Methylpentane
2-Methylpentane
4-Methyl- 1 -pentene
2-Methyl- 1 -pentene
w-Nonane
1-Nonene
w-Octane
1-Octene
w-Pentane
1 -Pentene
c/s-2-Pentene
trans-2-Pentene
a-Pinene
&-Pinene
Propane
w-Propylbenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
w-Tridecane
1-Tridecene
1 ,2,3 -Trimethylbenzene
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3 ,4-Trimethylpentane
w-Undecane
1-Undecene
w-Xylene/^-Xylene
o-Xylene
Number of
Observations
8
12
8
12
10
2
12
12
12
12
12
12
12
12
1
8
12
8
12
9
12
12
10
12
10
2
12
12
12
0
2
12
12
12
1
0
12
12
12
12
12
12
12
7
12
12
Average RPD
(%)
12.16
13.68
9.22
9.01
22.08
10.33
1.96
3.93
16.47
7.67
16.35
6.14
3.96
4.91
128.86
12.37
7.49
38.65
3.51
47.71
3.92
30.94
9.14
4.01
32.10
35.20
0.99
11.97
4.11
NA
55.54
3.78
13.27
5.81
61.78
NA
15.55
8.35
12.23
16.41
4.42
7.56
17.22
24.06
5.38
4.10
Average
Concentration
Difference (ppbC)
1.43
0.06
0.01
0.03
0.05
0.11
0.05
0.09
0.05
0.03
0.11
0.05
0.10
0.09
0.19
0.02
0.04
0.07
0.03
0.08
0.24
1.00
0.02
0.02
0.13
0.44
0.43
0.03
0.12
NA
0.21
4.22
21.30
0.35
0.18
NA
0.05
0.09
0.07
0.06
0.11
0.03
0.13
0.03
0.19
0.05
Coefficient of
Variation (%)
8.60
9.67
6.52
6.37
15.61
7.30
1.38
3.90
11.65
5.42
11.56
4.34
2.82
3.47
91.12
8.74
5.30
33.32
2.48
33.73
2.77
21.88
6.46
2.84
22.70
24.89
0.70
8.47
2.90
NA
39.27
2.67
9.39
4.11
43.69
NA
10.99
5.90
8.65
11.60
2.94
5.35
12.18
17.01
3.81
2.90
31-39
-------
Table 31-18. SNMOC Method Precision: 12 Collocated Samples
for Northbrook, IL (NBIL)
Pollutant
Acetylene
Benzene
1,3 -Butadiene
^-Butane
c/s-2-Butene
fraws-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
rc-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
rc-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
rc-Heptane
1-Heptene
^7-Hexane
1-Hexene
c/s-2-Hexene
fraws-2-Hexene
Isobutane
lsobutene/1 -Butene
Isopentane
Isoprene
Isopropylbenzene
2-Methyl-l-butene
2-Methyl-2-butene
3-Methyl-l-butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3 -Methy Ihexane
Number of
Observations
12
12
5
12
7
12
12
12
4
12
0
10
4
11
12
12
12
11
7
12
12
0
12
12
8
11
12
9
12
7
0
0
12
7
12
7
4
11
7
0
12
12
9
10
10
12
Average RPD
(%)
15.16
27.18
36.70
19.71
40.27
21.18
25.93
19.43
80.62
68.08
NA
43.90
114.98
43.66
33.36
35.77
27.63
60.62
37.45
35.17
40.27
NA
16.78
52.04
61.57
68.05
16.19
35.69
10.09
61.69
NA
NA
27.39
38.03
25.60
42.53
56.83
18.49
35.74
NA
19.78
16.70
43.40
20.86
27.78
22.25
Average
Concentration
Difference (ppbC)
0.23
0.33
0.03
0.73
0.03
0.03
0.06
0.03
0.20
0.88
NA
0.16
0.16
0.10
0.14
0.16
0.10
0.36
0.12
3.54
0.21
NA
0.36
0.24
0.27
0.20
0.07
0.04
0.12
0.09
NA
NA
0.56
0.27
2.10
0.51
0.07
0.16
0.08
NA
0.05
0.12
0.04
0.03
0.12
0.16
Coefficient of
Variation (%)
10.72
19.22
25.95
13.93
28.47
14.98
18.33
13.74
57.01
48.14
NA
31.04
81.31
30.87
23.59
25.29
19.54
42.86
26.48
24.87
28.48
NA
11.86
36.80
43.53
48.12
11.45
25.24
7.14
43.62
NA
NA
19.37
26.89
18.10
30.07
40.19
13.08
25.28
NA
13.99
13.85
30.69
14.75
19.65
15.73
31-40
-------
Table 31-18. SNMOC Method Precision: 12 Collocated Samples
for Northbrook, IL (NBIL) (Continued)
Pollutant
3-Methylpentane
2-Methylpentane
1-Methyl-l-pentene
2-Methyl-l-pentene
rc-Nonane
1-Nonene
rc-Octane
1-Octene
rc-Pentane
1-Pentene
c/s-2-Pentene
fraws-2-Pentene
a-Pinene
&-Pinene
Propane
rc-Propylbenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1 ,2,3 -Trimethylbenzene
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3,4-Trimethylpentane
w-Undecane
1-Undecene
w-Xylene/^-Xylene
o-Xylene
Number of
Observations
12
12
0
0
12
6
12
5
12
12
5
9
11
3
12
11
12
0
4
12
12
12
1
0
8
12
8
9
12
12
11
3
12
12
Average RPD
(%)
24.19
27.60
NA
NA
65.58
69.01
22.39
78.77
18.72
46.97
53.91
20.62
45.37
125.79
20.54
63.97
13.76
NA
62.04
18.41
34.57
35.52
129.67
NA
34.34
58.12
33.16
31.34
25.09
18.28
66.01
74.67
41.00
40.70
Average
Concentration
Difference (ppbC)
0.14
0.43
NA
NA
0.50
0.16
0.06
0.09
0.34
0.33
0.05
0.03
0.33
0.61
1.21
0.15
0.13
NA
0.11
11.87
41.95
0.68
0.30
NA
0.08
0.40
0.10
0.05
0.50
0.04
0.63
0.11
0.54
0.24
Coefficient of
Variation (%)
15.68
19.51
NA
NA
46.37
41.72
15.83
55.70
13.24
33.22
38.12
14.58
32.08
88.95
14.52
45.24
9.73
NA
43.87
13.02
24.45
25.11
91.69
NA
24.29
41.10
23.45
22.16
19.75
12.93
46.68
52.80
28.99
28.78
Table 31-19 presents the average CV per pollutant, per pollutant per site, per site, and the
overall CV for all UATMP and NATTS sites sampling SNMOC. The results from duplicate and
collocated samples show low- to high-level variability among sites, ranging from an average CV
of 10.84 percent at BTUT to 29.26 percent at NBIL, with an average of 20.45 percent. This
overall average exceeds the 15 percent CV program DQO.
31-41
-------
Table 31-19. SNMOC Method Precision: Coefficient of Variation
for all Duplicate and Collocated Samples by Site
Pollutant
Acetylene
Benzene
1,3 -Butadiene
w-Butane
c/5-2-Butene
trans-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
w-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
w-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
w-Heptane
1-Heptene
w-Hexane
1-Hexene
c/s-2-Hexene
trans-2-Hexene
Isobutane
Isobutene/ 1 -Butene
Isopentane
Isoprene
Isopropylbenzene
2-Methyl- 1 -butene
2-Methyl-2-butene
3 -Methyl- 1 -butene
Methylcyclohexane
Average
6.14
13.32
19.66
4.83
16.67
15.81
9.17
11.95
38.22
18.50
NA
32.75
48.17
15.86
8.72
13.62
10.82
33.03
52.51
6.74
13.72
NA
11.26
18.92
29.37
28.31
5.73
22.93
8.66
29.13
1.64
1.37
6.47
14.75
16.63
13.67
28.29
11.14
24.15
6.77
12.21
Bountiful, UT
(BTUT)
0.61
5.10
3.40
0.91
3.41
7.65
3.38
5.82
19.09
4.72
NA
20.24
23.01
3.94
2.63
4.07
2.68
21.07
40.78
0.80
6.64
NA
3.55
7.94
16.91
6.00
2.39
34.70
2.34
12.77
1.64
1.37
1.00
6.02
8.60
9.67
6.52
6.37
15.61
7.30
1.38
Custer, SD
(CUSD)
2.45
17.20
18.88
1.13
14.29
15.43
7.71
19.88
52.50
9.96
NA
45.96
33.91
10.99
6.70
16.23
11.39
26.39
80.20
0.60
6.80
NA
3.14
12.78
22.23
18.19
6.30
22.07
12.40
16.78
NA
NA
3.03
8.09
14.26
6.82
10.82
13.54
16.18
7.90
11.67
Gulfport, MS
(GPMS)
1.28
16.25
8.11
1.68
7.44
13.68
11.16
7.81
46.41
21.19
NA
45.12
54.45
16.34
7.52
14.75
12.23
49.47
39.56
0.40
13.42
NA
17.99
26.47
39.91
54.06
5.01
20.83
4.95
21.60
NA
NA
3.89
25.61
25.07
5.33
69.10
5.39
22.28
5.11
26.63
Northbrook, IL
(NBIL)
10.72
19.22
25.95
13.93
28.47
14.98
18.33
13.74
57.01
48.14
NA
31.04
81.31
30.87
23.59
25.29
19.54
42.86
26.48
24.87
28.48
NA
11.86
36.80
43.53
48.12
11.45
25.24
7.14
43.62
NA
NA
19.37
26.89
18.10
30.07
40.19
13.08
25.28
NA
13.99
0
in
*-.
%
"3
si
It
15.62
8.84
41.94
6.50
29.74
27.30
5.25
12.53
16.10
8.49
NA
21.40
NA
17.16
3.17
7.77
8.28
25.38
75.53
7.01
13.29
NA
19.73
10.60
24.24
15.21
3.52
11.84
16.45
50.89
NA
NA
5.09
7.12
17.11
16.47
14.83
17.34
41.41
NA
7.37
31-42
-------
Table 31-19. SNMOC Method Precision: Coefficient of Variation
for all Duplicate and Collocated Samples by Site (Continued)
Pollutant
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3 -Methy Ihexane
3-Methylpentane
2-Methylpentane
4-Methyl- 1 -pentene
2-Methyl- 1 -pentene
rc-Nonane
1-Nonene
n-Octane
1-Octene
rc-Pentane
1 -Pentene
c/s-2-Pentene
(raws-2-Pentene
a-Pinene
&-Pinene
Propane
rc-Propylbenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1 ,2,3 -Trimethylbenzene
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3 ,4-Trimethylpentane
rc-Undecane
1-Undecene
w-Xylene/p-Xylene
o-Xylene
Average
Average
7.27
30.90
10.23
26.29
13.51
8.28
22.95
91.12
23.75
16.70
20.17
8.04
32.85
7.39
19.87
27.86
11.11
40.14
62.30
4.65
27.05
14.87
NA
27.18
8.08
14.41
12.61
62.00
NA
21.21
19.25
21.63
31.00
8.19
14.82
24.69
55.04
15.00
10.43
20.45
Bountiful, UT
(BTUT)
3.90
11.65
5.42
11.56
4.34
2.82
3.47
91.12
8.74
5.30
33.32
2.48
33.73
2.77
21.88
6.46
2.84
22.70
24.89
0.70
8.47
2.90
NA
39.27
2.67
9.39
4.11
43.69
NA
10.99
5.90
8.65
11.60
2.94
5.35
12.18
17.01
3.81
2.90
10.84
Custer, SD
(CUSD)
8.79
23.97
15.89
30.53
16.45
8.29
18.99
NA
NA
6.68
9.96
6.38
23.67
7.19
14.52
20.65
10.27
20.92
78.88
1.45
14.77
3.46
NA
33.12
3.13
6.39
4.19
54.96
NA
11.97
16.92
13.21
31.50
3.76
13.22
13.87
NA
11.01
3.04
16.43
Gulfport, MS
(GPMS)
6.35
60.69
7.23
36.96
18.26
9.83
46.68
NA
38.76
16.49
6.57
8.30
17.82
5.44
10.48
20.09
11.61
70.28
56.48
0.48
31.75
31.45
NA
6.14
15.89
23.30
21.75
57.68
NA
32.45
22.37
32.15
64.17
6.23
28.65
31.67
39.72
25.75
11.26
23.27
Northbrook, IL
(NBIL)
13.85
30.69
14.75
19.65
15.73
15.68
19.51
NA
NA
46.37
41.72
15.83
55.70
13.24
33.22
38.12
14.58
32.08
88.95
14.52
45.24
9.73
NA
43.87
13.02
24.45
25.11
91.69
NA
24.29
41.10
23.45
22.16
19.75
12.93
46.68
52.80
28.99
28.78
29.26
P
in
*-.
%
"3
si
It
3.43
27.49
7.83
32.77
12.74
4.75
26.11
NA
NA
8.64
9.27
7.19
33.32
8.32
19.28
53.96
16.24
54.72
NA
6.11
35.02
26.79
NA
13.49
5.72
8.53
7.86
NA
NA
26.33
9.97
30.72
25.55
8.29
13.98
19.06
110.62
5.44
6.16
19.36
31-43
-------
31.1.3 Carbonyl Compounds Method Precision
Table 31-20 presents the method precision for duplicate and collocated carbonyl samples.
The average concentration difference ranged from 0.004 ppbv for 2,5-dimethylbenzaldehyde to
0.17 ppbv for formaldehyde.
Table 31-20. Carbonyl Method Precision: 352 Duplicate and Collocated Samples
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
352
352
352
352
352
1
352
346
73
350
344
349
Average RPD
(%)
6.91
10.77
11.36
8.09
7.74
21.81
7.10
12.98
18.77
8.19
12.77
14.42
Average
Concentration
Difference (ppbv)
0.08
0.09
0.005
0.01
0.01
0.004
0.17
0.01
0.01
0.01
0.005
0.01
Coefficient of
Variation (%)
4.89
6.94
8.07
5.72
5.48
15.42
5.02
9.18
13.27
5.79
9.03
10.20
The carbonyl method precision results for the 148 collocated samples are presented in
Table 31-21. The CV for carbonyl compounds ranged from 7.71 percent (crotonaldehyde) to
15.42 percent (2,5-dimethylbenzaldehyde).
Table 31-21. Carbonyl Method Precision: 148 Collocated Samples
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Number of
Observations
148
148
148
148
148
1
148
Average RPD
(%)
16.26
15.55
13.53
11.21
10.89
21.81
11.89
Average
Concentration
Difference (ppbv)
0.11
0.10
0.01
0.01
0.01
0.004
0.18
Coefficient of
Variation (%)
11.50
9.52
9.76
7.93
7.71
15.42
8.40
31-44
-------
Table 31-21. Carbonyl Method Precision: 148 Collocated Samples (Continued)
Pollutant
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
148
34
148
146
148
Average RPD
(%)
16.47
15.71
11.20
19.77
18.02
Average
Concentration
Difference (ppbv)
0.02
0.01
0.02
0.01
0.01
Coefficient of
Variation (%)
11.64
11.11
7.92
13.98
12.74
Table 31-22 presents method precision results from the 204 duplicate carbonyl samples.
The data show a low- to mid-level variability, ranging from 4.31 percent (acetaldehyde) to 20.16
percent (isovaleraldehyde), with an average of 9.27 percent.
Table 31-22. Carbonyl Method Precision: 204 Duplicate Samples
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
204
204
204
204
204
0
204
198
39
202
198
201
Average RPD
(%)
6.09
13.69
12.09
9.18
7.27
NA
8.41
16.75
28.51
8.77
14.30
19.46
Average
Concentration
Difference (ppbv)
0.12
0.09
0.004
0.01
0.01
NA
0.28
0.01
0.004
0.01
0.004
0.01
Coefficient of
Variation (%)
4.31
9.49
8.55
6.49
5.14
NA
5.95
11.84
20.16
6.20
10.11
13.76
Due to the focus on QA for the NATTS program, Tables 31-23 through 31-31 present
carbonyl method precision data for the NATTS sites (BTUT, DEMI, GPCO, NBIL, PXSS,
S4MO, SEW A, SKFL, and SYFL, respectively). Shaded rows present results for NATTS core
compounds. Table 31-23 shows that the carbonyl compound variation for the duplicate samples
at BTUT ranged from 1.72 percent (acetaldehyde) to 14.67 percent (hexaldehyde), with an
average of 5.13 percent.
31-45
-------
Table 31-23. Carbonyl Method Precision: 12 Duplicate Samples for Bountiful, UT (BTUT)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
12
12
12
12
12
0
12
12
4
12
12
12
Average RPD
(%)
2.44
2.41
8.78
4.67
4.50
NA
6.16
20.74
8.09
2.87
11.07
7.96
Average
Concentration
Difference (ppbv)
0.04
0.08
0.01
0.01
0.003
NA
0.13
0.01
0.003
0.01
0.01
0.01
Coefficient of
Variation (%)
1.72
1.78
6.21
3.30
3.18
NA
4.36
14.67
5.72
2.03
7.83
5.63
Table 31-24 shows the carbonyl method precision results for the collocated samples at
DEMI. The average concentration difference between collocated samples ranged from 0.004
ppbv (2,5-dimethylbenzaldehyde) to 0.57 ppbv (acetaldehyde), and the average variability was
19.23 percent.
Table 31-24. Carbonyl Method Precision: 4 Collocated Samples for Dearborn, MI (DEMI)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
4
4
4
4
4
1
4
4
0
4
3
4
Average RPD
(%)
35.26
14.58
27.62
24.55
14.94
21.81
16.64
31.90
NA
31.52
29.43
47.01
Average
Concentration
Difference (ppbv)
0.57
0.15
0.06
0.07
0.05
0.004
0.33
0.10
NA
0.17
0.01
0.06
Coefficient of
Variation (%)
24.93
10.31
22.14
17.36
10.68
15.42
11.77
22.56
NA
22.29
20.81
33.24
31-46
-------
Table 31-25 shows the carbonyl method precision results for the duplicate samples at
GPCO. The duplicate variability ranged from 0.46 percent (acetaldehyde) to 11.26 percent
(valeraldehyde). The average variability was 4.68 percent, which is within the program DQO.
Table 31-25. Carbonyl Method Precision: 12 Duplicate Samples
for Grand Junction, CO (GPCO)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
12
12
12
12
12
0
12
12
2
12
12
12
Average RPD
(%)
0.65
3.85
10.31
3.17
2.80
NA
2.77
11.82
11.76
3.70
2.82
15.92
Average
Concentration
Difference (ppbv)
0.01
0.07
0.01
0.002
0.002
NA
0.09
0.002
0.001
0.01
0.001
0.004
Coefficient of
Variation (%)
0.46
2.56
7.29
2.24
1.98
NA
1.96
8.36
8.32
2.61
2.00
11.26
Table 31-26 presents the carbonyl method precision results for collocated samples at
NBIL. The variability ranged from 29.10 percent for hexaldehyde to 67.70 percent for
acetaldehyde, with an average CV of 45.20 percent. All pollutants have RPD and CV outside the
program DQO.
Table 31-26. Carbonyl Method Precision: 12 Collocated Samples
for Northbrook, IL (NBIL)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Number of
Observations
12
12
12
12
12
0
12
Average RPD
(%)
95.74
102.48
52.23
58.13
55.85
NA
93.74
Average
Concentration
Difference (ppbv)
0.40
0.49
0.02
0.03
0.02
NA
0.91
Coefficient of
Variation (%)
67.70
62.58
36.94
41.10
39.49
NA
66.28
31-47
-------
Table 31-26. Carbonyl Method Precision: 12 Collocated Samples
for Northbrook, IL (NBIL) (Continued)
Pollutant
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
12
0
12
12
12
Average RPD
(%)
41.15
NA
58.47
49.25
46.16
Average
Concentration
Difference (ppbv)
0.01
NA
0.04
0.02
0.01
Coefficient of
Variation (%)
29.10
NA
41.35
34.82
32.64
The method precision results for the carbonyl analysis of the collocated samples at PXSS
are shown in Table 31-27. In terms of CV, the variability ranged from 1.59 percent (acetone) to
49.96 percent (hexaldehyde).
Table 31-27. Carbonyl Method Precision: 6 Collocated Samples
for Phoenix, AZ (PXSS)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
6
6
6
6
6
0
6
6
2
6
6
6
Average RPD
(%)
3.13
3.04
20.53
10.86
3.46
NA
5.36
70.66
NA
8.12
41.82
44.69
Average
Concentration
Difference (ppbv)
0.07
0.16
0.02
0.03
0.01
NA
0.25
0.11
NA
0.02
0.04
0.05
Coefficient of
Variation (%)
2.21
1.59
14.51
7.68
2.45
NA
3.79
49.96
NA
5.74
29.57
31.60
Table 31-28 shows the carbonyl method precision results for duplicate samples at S4MO.
Only one compound (hexaldehyde) was outside the specifications for CV, with an overall
average CV of 6.27 percent.
31-48
-------
Table 31-28. Carbonyl Method Precision: 12 Duplicate Samples
for St. Louis, MO (S4MO)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
12
12
12
12
12
0
12
12
2
12
12
12
Average RPD
(%)
7.22
10.87
10.11
6.46
7.43
NA
2.38
23.78
NA
8.31
5.88
7.88
Average
Concentration
Difference (ppbv)
0.19
0.15
0.004
0.01
0.01
NA
0.08
0.01
NA
0.01
0.002
0.003
Coefficient of
Variation (%)
5.11
6.47
7.15
4.57
5.25
NA
1.68
16.82
NA
5.87
4.16
5.57
The method precision results for the carbonyl analysis of the collocated samples at
SEWA are shown in Table 31-29. In terms of CV, the variability ranged from 1.13 percent
(isovaleraldehyde) to 9.19 percent (crotonaldehyde), with an average variability of 5.02 percent.
Table 31-29. Carbonyl Method Precision: 14 Collocated Samples
for Seattle, WA (SEWA)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
14
14
14
14
14
0
14
14
2
14
14
14
Average RPD
(%)
4.03
3.39
9.76
5.34
12.99
NA
10.24
3.34
1.60
11.03
8.16
8.82
Average
Concentration
Difference (ppbv)
0.03
0.04
0.004
0.005
0.01
NA
0.08
0.001
0.001
0.01
0.002
0.003
Coefficient of
Variation (%)
2.85
2.00
6.90
3.78
9.19
NA
7.24
2.36
1.13
7.80
5.77
6.24
31-49
-------
Table 31-30 presents the carbonyl method precision results for duplicate samples at
SKFL. Only one compound (isovaleraldehyde) was outside the specifications for CV, with the
overall average (10.89 percent) falling within the specifications.
Table 31-30. Carbonyl Method Precision: 12 Duplicate Samples
for Pinellas Park, FL (SKFL)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
14
14
14
14
14
0
14
14
3
14
14
14
Average RPD
(%)
4.62
8.77
7.20
5.10
3.21
NA
2.38
7.24
97.74
4.72
13.69
15.02
Average
Concentration
Difference (ppbv)
0.03
0.06
0.002
0.004
0.004
NA
0.02
0.002
0.01
0.003
0.003
0.003
Coefficient of
Variation (%)
3.27
5.99
5.09
3.61
2.27
NA
1.68
5.12
69.11
3.34
9.68
10.62
Table 31-31 shows carbonyl method precision results for duplicate samples at SYFL.
The average RPD and CV do not meet the NATTS requirements for most compounds.
Table 31-31. Carbonyl Method Precision: 14 Duplicate Samples
for Plant City, FL (SYFL)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Number of
Observations
14
14
14
14
14
0
14
14
3
Average RPD
(%)
29.04
44.51
43.03
42.90
17.44
NA
40.89
61.77
110.47
Average
Concentration
Difference (ppbv)
0.93
0.31
0.01
0.10
0.04
NA
3.10
0.08
0.02
Coefficient of
Variation (%)
20.54
35.01
30.43
30.33
12.33
NA
28.92
43.68
78.11
31-50
-------
Table 31-31. Carbonyl Method Precision: 14 Duplicate Samples
for Plant City, FL (SYFL) (Continued)
Pollutant
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
14
12
14
Average RPD
(%)
34.68
31.29
69.53
Average
Concentration
Difference (ppbv)
0.11
0.01
0.10
Coefficient of
Variation (%)
24.52
22.12
49.17
Table 31-32 presents the average CV per pollutant, per pollutant per site, per site, and the
overall average CV for all UATMP and NATTS sites sampling carbonyl compounds. The
duplicate and collocated sample results show low- to high-level variability among the sites,
ranging from an average CV of 2.76 percent at INDEM to 45.20 percent at NBIL, with an overall
average of 10.24 percent. This is within the 15 percent CV program DQO.
Table 31-32. Carbonyl Method Precision: Coefficient of Variation
for all Duplicate and Collocated Samples by Site
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
7.36
9.50
9.06
7.10
6.23
15.42
6.99
11.75
17.44
6.93
11.76
13.32
10.24
1
,fi
^
W ' V
"8 ^
t^
!/3 ^L
3.66
3.87
5.49
2.89
3.81
NA
13.64
13.97
3.72
2.12
6.53
5.98
5.97
a.
sS
«
a
® £"
"B £
£ ^
MB
4.54
9.69
7.46
15.44
6.99
NA
6.79
NA
NA
22.58
24.42
45.13
15.89
H
•V
3
*^« ^r~
a P
S H
M B
1.72
1.78
6.21
3.30
3.18
NA
4.36
14.67
5.72
2.03
7.83
5.63
5.13
Hj
Z
^
S t^A
"a z
i ^
u B
2.68
3.21
4.91
3.71
6.24
NA
5.56
5.96
10.10
2.52
7.91
17.84
6.42
Z
^
!• £ ^A
G« ^
_g M
6.48
7.07
5.65
1.74
5.98
NA
6.44
8.63
12.86
7.98
13.31
10.74
7.90
0
Tfl
r« ^> A
^ s
5« ^
uB
1.39
4.39
5.97
2.37
2.68
NA
4.49
9.16
4.56
4.13
12.69
7.28
5.37
HH
•V
2
^^ £ p
* S
•— ^
p B
24.93
10.31
22.14
17.36
10.68
15.42
11.77
22.56
NA
22.29
20.81
33.24
19.23
31-51
-------
Table 31-32. Carbonyl Method Precision: Coefficient of Variation
for all Duplicate and Collocated Analyses by Site (Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
7.36
9.50
9.06
7.10
6.23
15.42
6.99
11.75
17.44
6.93
11.76
13.32
10.24
Elizabeth, NJ
(ELNJ)
0.61
4.22
7.00
6.60
6.92
NA
1.04
10.27
4.56
4.05
5.98
6.21
5.22
-J
to
.$£
%£
Q &
2.97
19.59
2.89
1.94
1.94
NA
2.98
8.32
NA
4.66
5.24
NA
5.61
J
to
& h?
g-ta
s <
H£
3.41
22.26
12.89
9.29
6.36
NA
9.35
17.16
45.65
3.63
19.08
14.46
14.87
Grand Junction,
CO (GPCO)
0.46
2.56
7.29
2.24
1.98
NA
1.96
8.36
8.32
2.61
2.00
11.26
4.46
!/5
S
£ tt
&%
•3 SH
3£
2.96
8.41
6.13
4.50
5.55
NA
5.20
6.42
6.73
2.67
6.91
8.98
5.86
Indianapolis, IN
(IDIN)
0.89
0.62
7.75
4.33
5.79
NA
3.40
4.83
38.89
2.92
10.30
4.90
7.69
1$
^9
« z
O G,
0.91
1.03
4.20
2.44
3.40
NA
0.43
1.96
NA
3.24
6.56
3.39
2.76
Table 31-32. Carbonyl Method Precision: Coefficient of Variation
for all Duplicate and Collocated Analyses by Site (Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
7.36
9.50
9.06
7.10
6.23
15.42
6.99
11.75
17.44
6.93
11.76
13.32
10.24
Z
5«
"3
CS
1 z
"2 *
S §
2.90
2.42
10.21
3.34
4.29
NA
5.94
6.96
NA
6.73
36.26
6.93
8.60
£
a c-
® 6
•a H
s a
jd
0.47
2.43
2.77
2.87
3.36
NA
1.90
2.16
2.62
3.20
7.17
18.32
4.30
£
a" z
0 £
•a H
S £A
j S
1.30
1.41
5.84
2.13
1.73
NA
1.31
3.09
6.29
2.44
5.76
5.46
3.34
-J
0
S
•° ^
•o a
£ 05
z £>
67.70
62.58
36.94
41.10
39.49
NA
66.28
29.10
NA
41.35
34.82
32.64
45.20
Hn
Z
^
o
%
a
*?
S 05
Z O
7.80
3.03
9.95
7.56
9.98
NA
5.93
5.01
3.14
7.83
8.43
10.92
7.23
J
u.
•S
sS
PH
S ta
'^S
8.54
14.53
14.40
11.55
3.98
NA
5.52
7.14
3.93
7.14
6.72
6.16
8.15
SI
<
-
'i ^
S ^
* X
PHfe
2.21
1.59
14.51
7.68
2.45
NA
3.79
49.96
NA
5.74
29.57
31.60
14.91
31-52
-------
Table 31-32. Carbonyl Sampling and Analytical Precision: Coefficient of Variation
for all Duplicate and Collocated Analyses by Site (Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
7.36
9.50
9.06
7.10
6.23
15.42
6.99
11.75
17.44
6.93
11.76
13.32
10.24
O
s
€v
5«
'3 o
o a
j S
. TT
££
5.11
6.47
7.15
4.57
5.25
NA
1.68
16.82
NA
5.87
4.16
5.57
6.27
Seattle, WA
(SEWA)
2.85
2.00
6.90
3.78
9.19
NA
7.24
2.36
1.13
7.80
5.77
6.24
5.02
0
!/5
€N
5«
"3
ta K
gg
o ta
£ sa
1.77
2.35
8.00
2.37
4.52
NA
3.59
3.17
25.71
2.51
18.28
9.59
7.44
C£
0.
•N
es
3$
§^
$ S
2.30
18.59
4.71
6.18
1.89
NA
0.45
17.99
NA
1.89
6.50
13.33
7.38
Pinellas Park, FL
(SKFL)
3.27
5.99
5.09
3.61
2.27
NA
1.68
5.12
69.11
3.34
9.68
10.62
10.89
Schiller Park, IL
(SPIL)
50.90
35.01
9.00
12.68
15.98
NA
8.54
23.37
NA
3.97
14.89
10.86
18.52
Table 31-32. Carbonyl Sampling and Analytical Precision: Coefficient of Variation
for all Duplicate and Collocated Analyses by Site (Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
7.36
9.50
9.06
7.10
6.23
15.42
6.99
11.75
17.44
6.93
11.76
13.32
10.24
hJ
u.
$
ll
s s
20.54
35.01
30.43
30.33
12.33
NA
28.92
43.68
78.11
24.52
22.12
49.17
34.11
tt
°.s
c« O
•i °
nb
0.76
1.78
2.33
1.00
0.77
NA
2.02
5.82
9.08
1.51
6.54
6.54
3.47
^
°-s
n
H &
1.22
7.97
4.15
3.32
2.95
NA
0.67
4.10
NA
2.21
4.59
8.04
3.92
^
°ff
|g
nb
0.56
1.73
6.76
2.41
3.69
NA
1.87
2.96
NA
3.34
4.27
6.61
3.42
!/5
s
-sf
13 g
2-&
t2b
1.62
7.30
10.75
3.11
5.82
NA
3.46
11.30
NA
5.76
4.39
8.83
6.23
Indianapolis, IN
(WPIN)
3.42
2.38
3.10
6.57
4.16
NA
2.50
3.77
8.63
4.11
8.44
3.65
4.61
31-53
-------
31.1.4 Metals Method Precision
The method precision for all collocated metals samples are presented in Table 31-33.
The average CV values, as well as the average RPD values, show low- to high-level variability
with average CVs ranging from 4.66 percent for arsenic to 39.35 percent for mercury, with an
overall average at 11.13 percent.
Table 31-33. Metal Method Precision: 198 Collocated Samples
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
198
198
195
198
198
198
198
197
193
198
198
Average RPD
(%)
7.23
6.40
23.94
14.82
8.32
14.07
6.68
7.01
55.65
17.52
11.34
Average
Concentration
Difference (ng/m3)
0.08
0.08
0.003
0.05
0.21
0.07
0.46
1.29
1.60
0.42
0.07
Coefficient of
Variation (%)
5.11
4.66
16.93
10.48
5.88
9.95
4.73
4.96
39.35
12.39
8.02
Due to the focus on QA for the NATTS program, Tables 31-34 through 31-37 present the
method precision results from collocated PMio metals at the NATTS sites (BOMA, BTUT,
S4MO, and SEW A, respectively). Shaded rows present results for NATTS core compounds.
Variability ranged from 0.39 percent for antimony at SEWA to 95.87 percent for mercury at
BTUT.
Table 31-34. Metal Method Precision: 60 Collocated Samples
at Boston, MA (BOMA)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Number of
Observations
60
60
57
60
60
Average RPD
(%)
8.55
4.55
31.14
21.10
7.70
Average
Concentration
Difference (ng/m3)
0.08
0.02
0.001
0.03
0.16
Coefficient of
Variation (%)
6.04
3.45
22.02
14.92
5.45
31-54
-------
Table 31-34. Metal Method Precision: 60 Collocated Samples
at Boston, MA (BOMA) (Continued)
Pollutant
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
60
60
59
59
60
60
Average RPD
(%)
9.10
8.26
6.74
50.14
12.64
7.69
Average
Concentration
Difference (ng/m3)
0.01
0.37
0.27
0.03
0.31
0.02
Coefficient of
Variation (%)
6.44
5.84
4.77
35.46
8.94
5.44
Table 31-35. Metal Method Precision: 6 Collocated Samples
at Bountiful, UT (BTUT)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
6
6
6
6
6
6
6
6
5
6
6
Average RPD
(%)
4.96
9.77
32.25
4.34
13.02
12.61
5.00
10.54
135.58
39.28
27.62
Average
Concentration
Difference (ng/m3)
0.08
0.12
0.01
0.02
0.35
0.06
0.33
2.30
7.89
1.07
0.10
Coefficient of
Variation (%)
3.51
6.91
22.80
3.07
9.21
8.92
3.54
7.45
95.87
27.78
19.53
Table 31-36. Metal Method Precision: 22 Collocated Samples
at St. Louis, MO (S4MO)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Number of
Observations
22
22
22
22
22
22
22
22
Average RPD
(%)
6.53
6.29
17.62
15.35
7.26
20.40
8.16
7.27
Average
Concentration
Difference (ng/m3)
0.10
0.08
0.001
0.09
0.17
0.04
0.79
1.09
Coefficient of
Variation (%)
4.62
4.64
12.46
10.86
5.13
14.42
5.77
5.14
31-55
-------
Table 31-36. Metal Method Precision: 22 Collocated Samples
at St. Louis, MO (S4MO) (Continued)
Pollutant
Mercury
Nickel
Selenium
Number of
Observations
19
22
22
Average RPD
(%)
45.48
11.47
11.29
Average
Concentration
Difference (ng/m3)
0.03
0.14
0.12
Coefficient of
Variation (%)
32.16
8.11
7.98
Table 31-37. Metal Method Precision: 2 Collocated Samples
at Seattle, WA (SEWA)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
2
2
2
2
2
2
2
2
2
2
2
Average RPD
(%)
0.55
3.46
NA
8.96
3.70
3.88
0.79
1.07
6.06
9.89
1.58
Average
Concentration
Difference (ng/m3)
0.01
0.05
NA
0.02
0.13
0.01
0.07
0.30
0.001
0.28
0.01
Coefficient of
Variation (%)
0.39
2.45
NA
6.33
2.62
2.74
0.56
0.76
4.29
7.00
1.12
Table 31-38 presents the average CV per pollutant, per pollutant per site, per site, and the
overall average CV for all UATMP and NATTS sites sampling metals. The results from
collocated samples show low- to high-level variability among sites, ranging from 2.82 percent at
SEWAto 18.96 percent at BTUT, with an overall average of 11.13 percent.
31-56
-------
Table 31-38. Metal Method Precision: Coefficient of Variation
for all Collocated Samples by Site
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Average
Average
5.11
4.66
16.93
10.48
5.88
9.95
4.73
4.96
39.35
12.39
8.02
11.13
Boston, MA
(BOMA)
6.04
3.45
22.02
14.92
5.45
6.44
5.84
4.77
35.46
8.94
5.44
10.80
Bountiful, UT
(BTUT)
3.51
6.91
22.80
3.07
9.21
8.92
3.54
7.45
95.87
27.78
19.53
18.96
O
S
»T
"3 o
ai
. •*
£&
4.62
4.64
12.46
10.86
5.13
14.42
5.77
5.14
32.16
8.11
7.98
10.12
Seattle, WA
(SEWA)
0.39
2.45
NA
6.33
2.62
2.74
0.56
0.76
4.29
7.00
1.12
2.82
tt
°£
c? O
•i o
nb
11.01
5.85
10.43
17.23
7.01
17.24
7.92
6.66
28.98
10.11
6.01
11.68
31.1.5 Hexavalent Chromium Method Precision
The hexavalent chromium method precision results are shown in Table 31-39. All the
sites shown are NATTS sites except the ININ site. The average concentration differences
observed for collocated analyses of hexavalent chromium ranged from 0.001 ng/m3 at MVWI to
0.01 ng/m3 at several sites. The average RPD was higher than the program DQO specified 25
percent, with an overall average RPD of 35.36 percent. The RPD ranged from 11.21 percent at
PXSS to 96.66 percent at WADC. The CV ranged from 7.93 percent at PXSS to 68.35 percent at
WADC, with an overall average of 25.00 percent, which is outside the 15 percent program DQO.
Table 31-39. Hexavalent Chromium Method Precision: Collocated Samples
Site
BOMA
BTUT
BXNY
CHSC
Number of
Observations
8
58
2
4
Average
RPD (%)
22.01
23.99
16.63
65.89
Average
Concentration
Difference (ng/m3)
0.01
0.01
0.01
0.01
Coefficient of
Variation (%)
15.57
16.96
11.76
46.59
31-57
-------
Table 31-39. Hexavalent Chromium Method Precision: Collocated Samples (Continued)
Site
DEMI
GPCO
HAKY
ININ
MVWI
NBIL
PRRI
PXSS
S4MO
SDGA
SEWA
SYFL
UNVT
WADC
Average
Number of
Observations
14
12
8
12
4
8
8
12
10
8
12
10
6
6
;;
Average
RPD (%)
20.50
26.28
40.80
32.28
27.64
19.22
48.80
11.21
24.93
17.68
19.00
80.94
41.99
96.66
35.36
Average
Concentration
Difference (ng/m3)
0.003
0.003
0.004
0.01
0.001
0.01
0.004
0.01
0.003
0.003
0.01
0.01
0.004
0.01
0.01
Coefficient of
Variation (%)
14.50
18.58
28.85
22.83
19.54
13.59
34.50
7.93
17.63
12.50
13.44
57.23
29.69
68.35
25.00
* Over half of the measured detections were under the detection limit.
31.1.6 SVOC Method Precision
The method precision results for the collocated semivolatiles samples are shown in
Table 31-40. Both sites evaluated in this section are NATTS sites (RUCA and SDGA). The
average concentration differences observed for semivolatile compounds ranged from 0.02 ng/m3
for dibenz(a,h)anthracene to 10.74 ng/m3 for naphthalene. The average CV ranged from
11.30 percent for phenanthrene to 82.83 percent for coronene, with an overall average of 36.10
percent, which is outside the 15 percent program DQO.
Table 31-40. SVOC Method Precision: 50 Collocated Samples
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Number of
Observations
48
31
27
42
Average RPD
(%)
42.93
36.13
81.92
53.84
Average
Concentration
Difference (ng/m3)
0.31
0.47
0.29
0.03
Coefficient of
Variation (%)
30.35
25.55
57.93
38.07
31-58
-------
Table 31-40. SVOC Method Precision: 50 Collocated Samples (Continued)
Pollutant
Benzo (a) pyrene
Benzo (b) fluoranthene
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
lndeno(l,2,3-cd)pyrene
Naphthalene
Perylene
Phenanthrene
Pyrene
Number of
Observations
39
37
30
42
31
49
25
7
49
49
24
50
4
50
48
Average RPD
(%)
51.24
58.69
98.95
57.69
82.34
16.29
117.14
46.95
17.12
18.05
67.41
20.75
114.81
15.98
20.76
Average
Concentration
Difference (ng/m3)
0.09
0.05
0.05
0.04
0.04
0.03
0.05
0.02
0.17
0.45
0.04
10.74
0.04
0.81
0.14
Coefficient of
Variation (%)
36.23
41.50
69.97
40.80
58.23
11.52
82.83
33.20
12.10
12.76
13.11
14.67
81.18
11.30
14.68
Table 31-41 presents the method precision results for semivolatiles analysis of the
collocated samples for RUCA. In terms or CV, the variability of each pollutant is above the
program criteria, with an average variability of 40.25 percent.
Table 31-41. SVOC Method Precision: 42 Collocated Samples
at Rubidoux, CA (RUCA)
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Benzo (a) pyrene
Benzo (b) fluoranthene
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Number of
Observations
41
25
22
35
32
32
26
35
28
41
21
Average RPD
(%)
33.16
62.07
94.81
46.13
43.05
43.45
64.81
60.62
64.97
29.68
63.74
Average
Concentration
Difference (ng/m3)
0.53
0.80
0.55
0.04
0.09
0.08
0.06
0.06
0.06
0.07
0.05
Coefficient of
Variation (%)
23.44
43.89
67.04
32.62
30.44
30.72
45.83
42.87
45.94
20.99
45.07
31-59
-------
Table 31-41. SVOC Method Precision: 42 Collocated Samples
at Rubidoux, CA (RUCA) (Continued)
Pollutant
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
lndeno(l,2,3-cd)pyrene
Naphthalene
Perylene
Phenanthrene
Pyrene
Number of
Observations
5
41
41
21
42
2
42
40
Average RPD
(%)
86.72
31.03
30.69
33.73
31.76
199.61
29.21
32.35
Average
Concentration
Difference (ng/m3)
0.05
0.32
0.75
0.06
15.30
0.07
1.50
0.25
Coefficient of
Variation (%)
61.32
21.94
21.70
23.85
22.46
141.15
20.66
22.88
The semivolatiles method precision results for SDGA are shown in Table 31-42. In
terms of CV, the variability ranged from 1.95 percent (phenanthrene) to 120.59 percent
(coronene), with an average of 31.96 percent.
Table 31-42. SVOC Method Precision: 8 Collocated Samples
at Decatur, GA (SDGA)
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Benzo (a) pyrene
Benzo (b) fluoranthene
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
lndeno(l,2,3-cd)pyrene
Naphthalene
Number of
Observations
7
6
5
7
7
5
4
7
o
J
8
4
2
8
8
3
8
Average RPD
(%)
52.69
10.20
69.03
61.56
59.42
73.93
133.10
54.77
99.71
2.90
170.54
7.17
3.20
5.41
101.08
9.75
Average
Concentration
Difference (ng/m3)
0.09
0.15
0.03
0.01
0.10
0.01
0.04
0.02
0.01
0.003
0.05
0.002
0.02
0.15
0.01
6.18
Coefficient of
Variation (%)
37.26
7.21
48.81
43.53
42.02
52.28
94.11
38.72
70.51
2.05
120.59
5.07
2.27
3.82
2.38
6.89
31-60
-------
Table 31-42. SVOC Method Precision: 8 Collocated Samples
at Decatur, GA (SDGA) (Continued)
Pollutant
Perylene
Phenanthrene
Pyrene
Number of
Observations
2
8
8
Average RPD
(%)
30.00
2.75
9.16
Average
Concentration
Difference (ng/m3)
0.01
0.12
0.04
Coefficient of
Variation (%)
21.21
1.95
6.48
31.2 Analytical Precision
Analytical precision is a measurement of random errors associated with the process of
analyzing environmental samples. These errors may result from various factors, but typically
originate from random "noise" inherent to analytical instruments. Laboratories can easily
evaluate analytical precision by comparing concentrations measured during replicate analysis of
ambient air samples. The number of observations from Tables 31-43 through 31-83, in
comparison to the respective tables listed for duplicate or collocated analyses in Tables 31-2
through 31-42, is approximately twice as high because each sample produces a replicate for each
duplicate (or collocated) sample. Overall, the replicate analyses of both duplicate and collocated
samples of VOC, SNMOC, carbonyl compounds, and hexavalent chromium suggest the
analytical precision level is within the program DQOs.
31.2.1 VOC Analytical Precision
In Table 31-43, the analytical precision results from replicate analyses of all duplicate
and collocated samples show that for most of the pollutants, the VOC analysis precision was
within the program DQO of 15 percent for CV. The analytical precision of the VOC analytical
method, in terms of average concentration difference, ranged from 0.001 ppbv for
bromomethane and chloroprene to 0.32 ppbv for acetonitrile. In terms of CV, the overall
average variability was 16.92 percent and the median CV was 9.48 percent. The low median CV
shows that most of the pollutant variabilities were low. The relatively high average variability
was likely due to the substitution of non-detects with 1/2 the MDL.
31-61
-------
Table 31-43. VOC Analytical Precision: 596 Replicate Analyses
for all Duplicate and Collocated Samples
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
rc-Octane
Propylene
Number of
Observations
528
594
596
57
15
594
0
18
13
553
570
596
500
584
63
457
492
582
o
5
10
38
0
6
28
476
584
4
50
4
2
25
582
4
3
15
580
2
12
584
16
582
510
59
128
550
Average RPD
(%)
13.03
6.40
9.55
46.21
57.45
7.70
NA
40.58
52.49
11.18
8.93
7.88
6.63
7.69
30.75
14.93
13.19
5.42
12.15
122.61
74.21
NA
50.05
24.53
13.58
4.78
56.47
20.35
13.85
156.02
13.52
7.62
19.05
25.81
6.44
14.70
7.87
4.91
7.67
27.25
11.64
13.70
25.92
24.77
13.29
Average
Concentration
Difference (ppbv)
0.32
0.06
0.03
0.01
0.004
0.02
NA
0.07
0.01
0.001
0.003
0.01
0.06
0.01
0.004
0.002
0.02
0.03
0.001
0.03
0.01
NA
0.004
0.002
0.004
0.02
0.004
0.002
0.002
0.11
0.01
0.01
0.004
0.02
0.01
0.002
0.01
0.005
0.01
0.02
0.08
0.01
0.01
0.003
0.004
Coefficient of
Variation (%)
9.21
4.52
6.75
32.68
40.62
5.44
NA
28.69
37.12
7.90
6.32
5.57
4.69
5.44
21.74
10.56
9.33
3.84
8.59
86.70
52.47
NA
35.39
17.35
9.60
3.38
39.93
14.39
9.79
110.32
9.56
5.39
13.47
18.25
4.55
10.39
5.57
3.47
5.42
19.27
8.23
9.69
18.33
17.52
9.40
31-62
-------
Table 31-43. VOC Analytical Precision: 596 Replicate Analyses
for all Duplicate and Collocated Samples (Continued)
Pollutant
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
594
521
10
548
582
22
584
12
230
596
593
592
564
137
595
Average RPD
(%)
6.54
13.53
63.32
11.23
6.69
29.89
12.43
42.87
16.54
4.92
7.37
8.13
10.87
32.60
8.31
Average
Concentration
Difference (ppbv)
0.03
0.004
0.003
0.004
0.06
0.005
0.002
0.004
0.003
0.01
0.01
0.004
0.002
0.003
0.02
Coefficient of
Variation (%)
4.63
9.57
44.78
7.94
4.73
21.13
8.79
30.32
11.70
3.48
5.21
5.75
7.69
23.05
5.88
Table 31-44 shows the analytical precision results from replicate analyses of all
collocated VOC samples. The replicate results from collocated samples show variation for the
pollutants ranging from 0.001 percent (bromomethane, chloroprene, and 1,1,1-trichloroethane) to
0.54 percent (acetonitrile), as indicated by average concentration differences. The overall
average variability was 14.70 percent, which is within the program DQO.
Table 31-44. VOC Analytical Precision: 316 Replicate Analyses
for all Collocated Samples
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Number of
Observations
252
314
316
35
11
314
0
17
13
292
307
316
Average RPD
(%)
12.30
6.81
11.72
25.70
37.67
7.56
NA
23.47
52.49
10.32
9.29
8.14
Average
Concentration
Difference (ppbv)
0.54
0.05
0.03
0.01
0.004
0.02
NA
0.10
0.01
0.001
0.003
0.01
Coefficient of
Variation (%)
8.70
4.82
8.29
18.17
26.64
5.34
NA
16.60
37.12
7.29
6.57
5.75
31-63
-------
Table 31-44. VOC Analytical Precision: 316 Replicate Analyses
for all Collocated Samples (Continued)
Pollutant
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
fra«5-l,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fert-Butyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Number of
Observations
232
316
52
258
255
314
3
9
35
0
4
16
279
316
2
41
0
0
13
314
3
3
3
312
2
0
316
0
314
276
31
62
297
314
288
1
293
314
8
316
6
152
316
314
314
Average RPD
(%)
8.17
8.85
33.43
14.21
13.80
5.84
12.15
121.12
47.46
NA
35.90
28.23
12.08
5.20
68.61
12.05
NA
NA
15.34
8.62
14.37
25.81
6.04
17.43
7.87
NA
8.12
NA
13.09
13.78
22.59
7.98
12.47
6.59
12.86
120.13
12.44
7.27
10.82
14.12
44.33
14.02
5.44
7.78
7.77
Average
Concentration
Difference (ppbv)
0.08
0.01
0.004
0.003
0.03
0.03
0.001
0.03
0.01
NA
0.004
0.002
0.002
0.03
0.004
0.002
NA
NA
0.002
0.01
0.01
0.02
0.01
0.003
0.01
NA
0.01
NA
0.14
0.01
0.005
0.005
0.004
0.03
0.004
0.01
0.003
0.06
0.001
0.002
0.003
0.002
0.02
0.01
0.01
Coefficient of
Variation (%)
5.77
6.26
23.64
10.05
9.76
4.13
8.59
85.64
33.56
NA
25.39
19.97
8.54
3.68
48.52
8.52
NA
NA
10.85
6.10
10.16
18.25
4.27
12.33
5.57
NA
5.74
NA
9.26
9.74
15.97
5.64
8.82
4.66
9.09
84.94
8.80
5.14
7.65
9.98
31.35
9.91
3.85
5.50
5.49
31-64
-------
Table 31-44. VOC Analytical Precision: 316 Replicate Analyses
for all Collocated Samples (Continued)
Pollutant
Vinyl chloride
m,p-Xylene
o-Xylene
Number of
Observations
308
94
315
Average RPD
(%)
9.65
33.72
9.27
Average
Concentration
Difference (ppbv)
0.002
0.003
0.01
Coefficient of
Variation (%)
6.82
23.84
6.55
Table 31-45 shows the analytical precision results from replicate analyses of all duplicate
VOC samples. The variation of the replicate results from the duplicate samples ranged from
3.06 percent (1,1-dichloroethane) to 110.32 percent (/rami-l,2-dichloroethylene), as represented
by the CV. The overall average variability was 18.32 percent and the median CV was 8.51
percent.
Table 31-45. VOC Analytical Precision: 280 Replicate Analyses
for all Duplicate Samples
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
m -Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Number of
Observations
276
280
280
22
4
280
0
1
0
261
263
280
268
268
11
199
237
268
0
1
o
3
0
2
12
Average RPD
(%)
13.76
5.99
7.37
66.73
90.43
7.84
NA
74.80
NA
11.97
8.58
7.61
5.09
6.44
24.05
15.60
12.59
4.97
NA
130.06
136.63
NA
71.26
9.73
Average
Concentration
Difference (ppbv)
0.09
0.06
0.02
0.02
0.003
0.02
NA
0.01
NA
0.002
0.003
0.01
0.04
0.005
0.002
0.002
0.01
0.03
NA
0.02
0.01
NA
0.004
0.003
Coefficient of
Variation (%)
9.73
4.23
5.21
47.19
63.94
5.54
NA
52.89
NA
8.47
6.07
5.38
3.60
4.55
17.00
11.03
8.90
3.51
NA
91.96
96.61
NA
50.39
6.88
31-65
-------
Table 31-45. VOC Analytical Precision: 280 Replicate Analyses
for all Duplicate Samples (Continued)
Pollutant
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
^-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1,1,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethy Ibenzene
Vinyl chloride
w,£>-Xylene
o-Xylene
Number of
Observations
197
268
2
9
4
2
12
268
1
0
12
268
0
12
268
16
268
234
28
66
253
280
233
9
255
268
14
268
6
78
280
279
278
256
43
280
Average RPD
(%)
15.08
4.33
44.33
28.65
13.85
156.02
6.24
6.61
28.40
NA
7.23
11.74
NA
4.91
7.18
27.25
10.19
13.63
34.23
33.17
14.12
6.50
14.26
6.52
10.12
6.07
36.24
10.60
40.44
19.91
4.40
6.97
8.46
12.09
30.75
7.36
Average
Concentration
Difference (ppbv)
0.01
0.02
0.003
0.002
0.002
0.11
0.03
0.01
0.002
NA
0.001
0.001
NA
0.005
0.01
0.02
0.03
0.01
0.04
0.003
0.004
0.03
0.003
0.001
0.005
0.06
0.01
0.002
0.01
0.004
0.01
0.01
0.003
0.001
0.004
0.02
Coefficient of
Variation (%)
10.66
3.06
31.35
20.26
9.79
110.32
4.41
4.67
20.08
NA
5.11
8.30
NA
3.47
5.07
19.27
7.21
9.64
24.21
23.45
9.98
4.60
10.09
4.61
7.16
4.29
25.63
7.49
28.59
14.08
3.11
4.93
5.98
8.55
21.75
5.21
Due to the focus on QA for the NATTS program, Tables 31-46 through 31-54 present the
analytical precision data results from VOC replicate analyses for all the samples taken at the
NATTS sites (BTUT, CAMS 35, CAMS 85, DEMI, GPCO, NBIL, PXSS, S4MO, and SEWA,
respectively). Shaded rows present results for the NATTS core compounds. These results show
low- to high-level variability among the sites, as represented by CV, ranging from 0.76 percent
31-66
-------
(for acrylonitrile at NBIL) to 105.82 percent (for dibromochloromethane at BTUT), with an
average of 10.89 percent. This is within the program DQO of 15 percent overall CV per site.
Table 31-46. VOC Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Bountiful, UT (BTUT)
Compound
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Number of
Observations
24
24
24
1
0
24
0
0
0
24
24
24
24
0
17
23
24
0
0
1
0
0
0
24
24
0
0
0
0
0
24
1
0
0
24
0
0
24
0
24
Average RPD
(%)
6.04
4.99
6.02
55.53
NA
5.21
NA
NA
NA
8.94
6.74
4.30
5.81
NA
12.35
16.17
5.27
NA
NA
149.66
NA
NA
NA
6.63
4.42
NA
NA
NA
NA
NA
4.62
28.40
NA
NA
11.23
NA
NA
4.10
NA
6.82
Average
Concentration
Difference (ppbv)
0.09
0.04
0.01
0.01
NA
0.03
NA
NA
NA
0.001
0.003
0.05
0.004
NA
0.001
0.003
0.03
NA
NA
0.01
NA
NA
NA
0.002
0.02
NA
NA
NA
NA
NA
0.01
0.002
NA
NA
0.002
NA
NA
0.01
NA
0.03
Coefficient of
Variation (%)
4.27
3.53
4.25
39.27
NA
3.68
NA
NA
NA
6.32
4.77
3.04
4.10
NA
8.73
11.43
3.73
NA
NA
105.82
NA
NA
NA
4.69
3.13
NA
NA
NA
NA
NA
3.27
20.08
NA
NA
7.94
NA
NA
2.90
NA
4.82
31-67
-------
Table 31-46. VOC Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Bountiful, UT (BTUT) (Continued)
Compound
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1,1,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
w,£>-Xylene
o-Xylene
Number of
Observations
24
0
0
24
24
24
0
24
24
0
24
0
12
24
24
24
24
8
24
24
Average RPD
(%)
7.30
NA
NA
5.82
6.71
7.11
NA
6.11
4.48
NA
2.46
NA
3.26
5.15
5.48
4.29
4.40
20.08
4.16
4.99
Average
Concentration
Difference (ppbv)
0.003
NA
NA
0.004
0.05
0.002
NA
0.003
0.05
NA
<0.001
NA
0.001
0.01
0.01
0.004
0.001
0.001
0.02
0.01
Coefficient of
Variation (%)
5.16
NA
NA
4.12
4.75
5.02
NA
4.32
3.17
NA
1.74
NA
2.31
3.64
3.87
3.03
3.11
14.20
2.94
3.53
Table 31-47. VOC Analytical Precision: 80 Replicate Analyses
for Collocated Samples for Deer Park, TX (CAMS 35)
Compound
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Number of
Observations
47
80
82
22
4
80
0
3
3
82
82
31
82
22
70
77
80
Average RPD
(%)
16.33
6.22
8.61
8.21
25.66
6.00
NA
8.31
34.86
9.51
8.00
13.59
6.61
10.83
15.52
11.85
5.17
Average
Concentration
Difference (ppbv)
0.02
0.03
0.02
0.04
0.01
0.02
NA
0.001
0.002
0.002
0.01
0.002
0.01
0.003
0.004
0.004
0.03
Coefficient of
Variation (%)
11.54
4.40
6.09
5.81
18.15
4.24
NA
5.88
24.65
6.73
5.65
9.61
4.68
7.65
10.97
8.38
3.66
31-68
-------
Table 31-47. VOC Analytical Precision: 80 Replicate Analyses
for Collocated Samples for Deer Park, TX (CAMS 35) (Continued)
Compound
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
^-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1,1,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
w,£>-Xylene
o-Xylene
Number of
Observations
0
5
4
0
2
3
74
82
1
33
0
0
2
80
2
2
2
79
2
0
82
0
82
67
16
48
79
80
69
0
72
80
0
82
0
28
82
82
80
78
52
82
82
Average RPD
(%)
NA
119.73
43.48
NA
11.24
66.43
9.48
4.89
68.61
12.18
NA
NA
33.33
7.88
13.53
7.87
8.23
12.69
7.87
NA
7.25
NA
7.82
10.34
13.99
8.51
15.34
6.13
10.55
NA
12.77
5.71
NA
7.56
NA
9.67
5.67
5.07
6.19
9.72
7.87
6.10
8.00
Average
Concentration
Difference (ppbv)
NA
0.02
0.01
NA
0.01
0.004
0.001
0.02
0.004
0.01
NA
NA
0.004
0.01
0.01
0.04
0.02
0.002
0.01
NA
0.004
NA
0.02
0.003
0.01
0.01
0.004
0.11
0.002
NA
0.003
0.03
NA
0.001
NA
0.002
0.01
0.005
0.003
0.002
0.002
0.01
0.01
Coefficient of
Variation (%)
NA
84.66
30.75
NA
7.95
46.97
6.71
3.46
48.52
8.61
NA
NA
23.57
5.57
9.57
5.57
5.82
8.97
5.57
NA
5.13
NA
5.53
7.31
9.89
6.02
10.84
4.34
7.46
NA
9.03
4.04
NA
5.35
NA
6.84
4.01
3.58
4.38
6.88
5.56
4.31
5.65
31-69
-------
Table 31-48. VOC Analytical Precision: 4 Replicate Analyses
for Collocated Samples for Karnack, TX (CAMS 85)
Compound
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
^-Octane
Propylene
Number of
Observations
0
4
4
0
0
4
0
0
0
4
4
0
4
0
4
4
4
0
0
0
0
0
0
4
4
0
4
0
0
0
4
0
0
0
4
0
0
4
0
4
0
0
2
4
4
Average RPD
(%)
2.53
2.30
15.20
NA
NA
4.71
NA
NA
NA
NA
7.69
7.17
33.33
NA
NA
53.33
5.11
NA
NA
NA
NA
NA
NA
20.00
4.13
NA
NA
NA
NA
NA
NA
NA
NA
NA
33.33
NA
NA
5.88
NA
6.52
NA
NA
NA
19.05
NA
Average
Concentration
Difference (ppbv)
0.02
0.04
0.03
NA
NA
0.03
NA
NA
NA
NA
0.01
0.09
0.01
NA
NA
0.01
0.03
NA
NA
NA
NA
NA
NA
0.01
0.03
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.01
NA
NA
0.01
NA
0.02
NA
NA
NA
0.01
NA
Coefficient of
Variation (%)
1.79
1.63
10.75
NA
NA
3.33
NA
NA
NA
NA
5.44
5.07
23.57
NA
NA
37.71
3.62
NA
NA
NA
NA
NA
NA
14.14
2.92
NA
NA
NA
NA
NA
NA
NA
NA
NA
23.57
NA
NA
4.16
NA
4.61
NA
NA
NA
13.47
NA
31-70
-------
Table 31-48. VOC Analytical Precision: 4 Replicate Analyses
for Collocated Samples for Karnack, TX (CAMS 85) (Continued)
Compound
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
4
0
4
4
0
4
0
0
4
4
4
4
2
4
4
Average RPD
(%)
14.29
NA
NA
3.62
NA
33.33
NA
NA
3.23
10.00
NA
NA
NA
2.33
5.88
Average
Concentration
Difference (ppbv)
0.01
NA
NA
0.02
NA
0.01
NA
NA
0.02
0.01
NA
NA
NA
0.01
0.01
Coefficient of
Variation (%)
10.10
NA
NA
2.56
NA
23.57
NA
NA
2.28
7.07
NA
NA
NA
1.64
4.16
Table 31-49. VOC Analytical Precision: 24 Replicate Analyses
for Collocated Samples for Dearborn, MI (DEMI)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
Number of
Observations
24
24
24
0
0
24
0
0
0
24
24
17
24
24
24
24
24
2
0
0
0
0
Average RPD
(%)
7.69
5.07
5.11
NA
NA
5.46
NA
NA
NA
7.63
4.83
6.63
4.33
4.21
16.76
7.21
4.36
NA
NA
NA
NA
NA
Average
Concentration
Difference (ppbv)
0.02
0.03
0.01
NA
NA
0.01
NA
NA
NA
0.001
0.001
0.002
0.004
0.002
0.003
0.01
0.02
NA
NA
NA
NA
NA
Coefficient of
Variation (%)
5.44
3.59
3.61
NA
NA
3.86
NA
NA
NA
5.40
3.41
4.69
3.06
2.98
11.85
5.10
3.09
NA
NA
NA
NA
NA
31-71
-------
Table 31-49. VOC Analytical Precision: 24 Replicate Analyses
for Collocated Samples for Dearborn, MI (DEMI) (Continued)
Pollutant
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 , 3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fert-Butyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
0
24
24
0
0
0
0
1
24
0
0
0
24
0
0
24
0
23
24
0
0
21
24
21
0
21
24
0
24
0
11
24
23
24
24
2
24
24
Average RPD
(%)
NA
6.89
3.96
NA
NA
NA
NA
1.37
6.24
NA
NA
NA
7.18
NA
NA
4.39
NA
19.86
8.20
NA
NA
12.09
6.26
7.91
NA
10.87
5.10
NA
10.08
NA
18.71
3.87
17.00
5.12
4.21
NA
4.60
5.32
Average
Concentration
Difference (ppbv)
NA
0.001
0.02
NA
NA
NA
NA
<0.001
0.004
NA
NA
NA
0.001
NA
NA
0.002
NA
0.02
0.003
NA
NA
0.001
0.02
0.001
NA
0.002
0.01
NA
0.002
NA
0.002
0.01
0.01
0.002
0.001
NA
0.004
0.002
Coefficient of
Variation (%)
NA
4.87
2.80
NA
NA
NA
NA
0.97
4.41
NA
NA
NA
5.08
NA
NA
3.10
NA
14.04
5.80
NA
NA
8.55
4.42
5.59
NA
7.69
3.60
NA
7.13
NA
13.23
2.74
12.02
3.62
2.98
NA
3.25
3.76
31-72
-------
Table 31-50. VOC Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Grand Junction, CO (GPCO)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Acrylate
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
^-Octane
Propylene
Number of
Observations
24
24
24
2
0
24
0
1
0
24
24
24
24
1
16
24
24
0
1
0
0
0
0
24
24
0
1
0
1
0
24
0
0
0
24
0
0
24
1
24
24
16
1
24
24
Average RPD
(%)
6.93
5.26
6.85
109.32
NA
5.87
NA
74.80
NA
10.46
5.19
4.10
8.17
38.89
10.34
6.71
4.64
NA
130.06
NA
NA
NA
NA
6.32
4.66
NA
5.59
NA
128.68
NA
4.83
NA
NA
NA
3.74
NA
NA
5.58
9.83
6.05
8.81
43.27
72.60
7.69
4.21
Average
Concentration
Difference (ppbv)
0.11
0.08
0.03
0.03
NA
0.03
NA
0.01
NA
0.001
0.004
0.06
0.01
0.003
0.001
0.001
0.02
NA
0.02
NA
NA
NA
NA
0.001
0.02
NA
0.001
NA
0.03
NA
0.005
NA
NA
NA
0.001
NA
NA
0.01
0.002
0.03
0.01
0.07
0.01
0.004
0.02
Coefficient of
Variation (%)
4.90
3.72
4.84
77.30
NA
4.15
NA
52.89
NA
7.39
3.67
2.90
5.78
27.50
7.31
4.75
3.28
NA
91.96
NA
NA
NA
NA
4.47
3.29
NA
3.95
NA
90.99
NA
3.42
NA
NA
NA
2.64
NA
NA
3.94
6.95
4.28
6.23
30.59
51.33
5.43
2.97
31-73
-------
Table 31-50. VOC Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Grand Junction, CO (GPCO) (Continued)
Pollutant
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
24
0
24
24
0
24
0
12
24
24
24
24
2
24
24
Average RPD
(%)
3.33
NA
6.21
5.22
NA
5.63
NA
7.11
4.51
3.86
4.92
7.53
NA
5.41
5.26
Average
Concentration
Difference (ppbv)
0.004
NA
0.004
0.07
NA
0.001
NA
0.001
0.01
0.004
0.01
0.002
NA
0.03
0.01
Coefficient of
Variation (%)
2.36
NA
4.39
3.69
NA
3.98
NA
5.03
3.19
2.73
3.48
5.33
NA
3.83
3.72
Table 31-51. VOC Analytical Precision: 18 Replicate Analyses
for Collocated Samples for Northbrook, IL (NBIL)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
ter/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethy Ibenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
Number of
Observations
17
18
18
1
0
18
0
14
1
15
14
14
18
0
14
18
18
0
0
12
0
0
Average RPD
(%)
39.57
10.63
21.26
1.07
NA
9.91
NA
38.63
124.46
8.23
14.35
9.79
7.23
NA
14.10
25.17
5.40
NA
NA
36.54
NA
NA
Average
Concentration
Difference (ppbv)
0.18
0.07
0.03
O.001
NA
0.01
NA
0.19
0.02
0.001
0.003
0.003
0.01
NA
0.002
0.38
0.03
NA
NA
0.08
NA
NA
Coefficient of
Variation (%)
27.98
7.52
15.04
0.76
NA
7.01
NA
27.32
88.01
5.82
10.14
6.92
5.11
NA
9.97
17.80
3.82
NA
NA
25.84
NA
NA
31-74
-------
Table 31-51. VOC Analytical Precision: 18 Replicate Analyses
for Collocated Samples for Northbrook, IL (NBIL) (Continued)
Pollutant
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1, 1-Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 , 3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fert-Butyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
0
13
18
0
2
0
0
0
18
0
0
0
18
0
0
18
0
18
17
0
0
12
18
14
0
18
18
0
18
0
13
18
18
18
14
2
18
18
Average RPD
(%)
NA
16.27
6.16
NA
14.36
NA
NA
NA
10.36
NA
NA
NA
7.26
NA
NA
19.30
NA
26.16
35.78
NA
NA
5.42
9.12
25.07
NA
12.38
13.81
NA
9.50
NA
20.73
7.70
6.07
18.43
17.91
54.28
17.45
15.85
Average
Concentration
Difference (ppbv)
NA
0.002
0.03
NA
0.002
NA
NA
NA
0.01
NA
NA
NA
0.001
NA
NA
0.01
NA
1.03
0.01
NA
NA
0.002
0.02
0.003
NA
0.003
0.04
NA
0.002
NA
0.004
0.02
0.01
0.01
0.003
0.01
0.02
0.01
Coefficient of
Variation (%)
NA
11.51
4.36
NA
10.15
NA
NA
NA
7.33
NA
NA
NA
5.13
NA
NA
13.65
NA
18.49
25.30
NA
NA
3.83
6.45
17.73
NA
8.75
9.77
NA
6.72
NA
14.66
5.44
4.30
13.03
12.67
38.38
12.34
11.21
31-75
-------
Table 31-52. VOC Analytical Precision: 12 Replicate Analyses
for Collocated Samples for Phoenix, AZ (PXSS)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
^-Octane
Propylene
Number of
Observations
12
12
12
0
0
12
0
0
4
10
12
12
12
0
12
12
12
0
0
8
0
1
8
12
12
0
0
0
0
0
12
0
1
1
11
0
0
12
0
12
12
0
0
12
12
Average RPD
(%)
8.99
3.64
11.72
NA
NA
12.68
NA
NA
17.78
12.83
5.68
5.07
8.33
NA
6.69
6.31
3.51
NA
NA
4.55
NA
37.74
3.85
10.43
2.73
NA
NA
NA
NA
NA
8.43
NA
43.74
3.85
31.48
NA
NA
12.94
NA
9.64
11.14
NA
NA
9.71
2.96
Average
Concentration
Difference (ppbv)
0.13
0.02
0.08
NA
NA
0.03
NA
NA
0.001
0.001
0.003
0.003
0.003
NA
0.001
0.003
0.01
NA
NA
0.001
NA
0.002
0.001
0.002
0.01
NA
NA
NA
NA
NA
0.01
NA
0.004
0.000
0.002
NA
NA
0.01
NA
0.10
0.01
NA
NA
0.002
0.02
Coefficient of
Variation (%)
6.36
2.57
8.29
NA
NA
8.97
NA
NA
12.57
9.07
4.01
3.58
5.89
NA
4.73
4.46
2.48
NA
NA
3.22
NA
26.69
2.72
7.38
1.93
NA
NA
NA
NA
NA
5.96
NA
30.93
2.73
22.26
NA
NA
9.15
NA
6.82
7.88
NA
NA
6.86
2.09
31-76
-------
Table 31-52. VOC Analytical Precision: 12 Replicate Analyses
for Collocated Samples for Phoenix, AZ (PXSS) (Continued)
Pollutant
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
12
0
12
12
8
12
0
4
12
12
12
12
5
12
12
Average RPD
(%)
8.13
NA
11.76
15.32
10.82
12.77
NA
6.93
3.55
4.34
12.55
10.64
40.38
13.39
11.67
Average
Concentration
Difference (ppbv)
0.003
NA
0.004
0.13
0.001
0.001
NA
0.001
0.01
0.001
0.01
0.002
0.003
0.03
0.01
Coefficient of
Variation (%)
5.75
NA
8.31
10.84
7.65
9.03
NA
4.90
2.51
3.07
8.87
7.52
28.55
9.47
8.25
Table 31-53. VOC Analytical Precision: 22 Replicate Analyses
for Duplicate Samples for St. Louis, MO (S4MO)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethy Ibenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
Number of
Observations
21
22
22
0
0
22
0
0
0
22
22
22
22
0
12
22
22
0
0
0
0
0
Average RPD
(%)
20.46
5.07
3.59
NA
NA
3.49
NA
NA
NA
6.80
11.99
3.20
2.93
NA
25.52
5.93
3.54
NA
NA
NA
NA
NA
Average
Concentration
Difference (ppbv)
0.04
0.04
0.01
NA
NA
0.01
NA
NA
NA
0.001
0.003
0.02
0.003
NA
0.003
0.001
0.02
NA
NA
NA
NA
NA
Coefficient of
Variation (%)
14.47
3.59
2.54
NA
NA
2.47
NA
NA
NA
4.81
8.48
2.26
2.07
NA
18.05
4.19
2.50
NA
NA
NA
NA
NA
31-77
-------
Table 31-53. VOC Analytical Precision: 22 Replicate Analyses
for Duplicate Samples for St. Louis, MO (S4MO) (Continued)
Pollutant
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
c/s-l,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tort-Butyl Ether
Ethylbenzene
Hexachloro- 1 , 3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
rc-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
0
18
22
0
0
0
0
0
22
0
0
0
22
0
0
22
0
22
19
0
1
22
22
18
0
22
22
1
22
0
3
22
22
22
19
1
22
22
Average RPD
(%)
NA
6.88
3.33
NA
NA
NA
NA
NA
7.74
NA
NA
NA
13.61
NA
NA
3.41
NA
3.49
8.12
NA
80.12
17.58
4.03
10.78
NA
9.69
3.85
58.58
9.18
NA
66.52
2.74
3.65
2.98
17.53
83.82
2.06
3.54
Average
Concentration
Difference (ppbv)
NA
0.001
0.02
NA
NA
NA
NA
NA
0.01
NA
NA
NA
0.002
NA
NA
0.002
NA
0.01
0.002
NA
0.003
0.004
0.01
0.002
NA
0.002
0.01
0.01
0.002
NA
0.01
0.01
0.004
0.002
0.002
0.01
0.002
0.002
Coefficient of
Variation (%)
NA
4.86
2.35
NA
NA
NA
NA
NA
5.47
NA
NA
NA
9.62
NA
NA
2.41
NA
2.47
5.74
NA
56.66
12.43
2.85
7.62
NA
6.85
2.72
41.42
6.49
NA
47.04
1.94
2.58
2.11
12.40
59.27
1.45
2.50
31-78
-------
Table 31-54. VOC Analytical Precision: 28 Replicate Analyses
for Collocated Samples for Seattle, WA (SEWA)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -Dichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fer/-Butyl Ether
^-Octane
Propylene
Number of
Observations
20
28
28
2
0
28
0
0
0
24
28
18
28
1
24
27
28
0
0
1
0
0
0
17
28
1
0
0
0
9
28
0
0
0
28
0
0
28
0
28
25
0
0
28
28
Average RPD
(%)
10.57
8.33
18.22
55.67
NA
8.56
NA
NA
NA
7.88
8.91
25.27
5.34
51.08
19.53
16.39
4.50
NA
NA
53.82
NA
NA
NA
10.91
4.40
68.61
NA
NA
NA
14.70
9.11
NA
NA
NA
21.05
NA
NA
11.93
NA
20.01
13.46
NA
NA
14.97
8.19
Average
Concentration
Difference (ppbv)
0.02
0.05
0.04
0.01
NA
0.02
NA
NA
NA
0.001
0.003
0.49
0.01
0.003
0.004
0.004
0.02
NA
NA
0.003
NA
NA
NA
0.001
0.02
0.004
NA
NA
NA
0.002
0.01
NA
NA
NA
0.02
NA
NA
0.01
NA
0.11
0.003
NA
NA
0.003
0.03
Coefficient of
Variation (%)
7.48
5.89
12.88
39.36
NA
6.06
NA
NA
NA
5.57
6.30
17.87
3.78
36.12
13.81
11.59
3.18
NA
NA
38.06
NA
NA
NA
7.71
3.11
48.52
NA
NA
NA
10.40
6.44
NA
NA
NA
14.88
NA
NA
8.43
NA
14.15
9.52
NA
NA
10.58
5.79
31-79
-------
Table 31-54. VOC Analytical Precision: 28 Replicate Analyses
for Collocated Samples for Seattle, WA (SEWA) (Continued)
Pollutant
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
«,/?-Xylene
o-Xylene
Number of
Observations
28
0
26
28
0
28
1
17
28
28
28
28
1
28
28
Average RPD
(%)
20.84
NA
14.92
10.63
NA
11.00
72.49
16.39
5.31
5.66
9.17
10.63
68.24
19.88
12.28
Average
Concentration
Difference (ppbv)
0.01
NA
0.002
0.05
NA
0.002
0.005
0.002
0.01
0.01
0.004
0.002
0.01
0.02
0.01
Coefficient of
Variation (%)
14.74
NA
10.55
7.51
NA
7.78
51.26
11.59
3.75
4.00
6.48
7.52
48.25
14.06
8.68
Table 31-55 shows the average CV per pollutant, per pollutant per site, per site, and the
overall average CV for all UATMP and NATTS sites sampling VOC. The average site CV
ranged from 4.69 percent at SJPR and TUMS to 17.54 percent at CHNJ, with an overall program
average CV of 9.21 percent. This meets the 15 percent CV program DQO.
31-80
-------
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
fer/-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
Average
9. 21
4.52
6.75
32.68
40.62
5.44
NA
28.69
37.12
7.90
6.32
4.59
5.47
24.28
10.69
9.21
3.94
8.59
86.70
52.47
NA
35.39
19.97
9.62
3.50
39.93
14.39
9.79
Barceloneta, PR
(BAPR)
8.12
6.15
5.86
61.22
63.94
11.19
NA
NA
NA
10.71
5.98
3.84
6.20
NA
6.51
3.33
6.47
NA
NA
NA
NA
NA
NA
6.88
6.43
NA
NA
NA
Bountiful, UT
(BTUT)
4.27
3.53
4.25
39.27
NA
3.68
NA
NA
NA
6.32
4.77
3.04
4.10
NA
8.73
11.43
3.73
NA
NA
105.82
NA
NA
NA
4.69
3.13
NA
NA
NA
Deer Park , TX
(CAMS 35)
11.54
4.40
6.09
5.81
18.15
4.24
NA
5.88
24.65
6.73
5.65
9.61
4.68
7.65
10.97
8.38
3.66
NA
84.66
30.75
NA
7.95
46.97
6.71
3.46
48.52
8.61
NA
Karnack , TX
(CAMS 85)
1.79
1.63
10.75
NA
NA
3.33
NA
NA
NA
NA
5.44
5.07
23.57
NA
NA
37.71
3.62
NA
NA
NA
NA
NA
NA
14.14
2.92
NA
NA
NA
Camden, NJ
(CANJ)
5.56
3.12
8.47
47.81
63.94
5.88
NA
NA
NA
7.44
5.03
3.60
7.40
NA
10.92
12.59
3.41
NA
NA
NA
NA
NA
NA
13.15
2.87
NA
NA
NA
Chester, NJ
(CHNJ)
7.95
5.56
6.68
40.10
NA
7.88
NA
NA
NA
6.92
5.85
4.71
6.64
NA
6.67
7.77
4.34
NA
NA
105.82
NA
NA
NA
35.20
3.80
NA
NA
NA
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4.38
4.19
5.39
61.22
2.07
6.89
NA
NA
NA
6.12
8.89
4.07
5.79
10.36
4.48
15.91
4.18
NA
89.09
17.96
NA
NA
10.15
17.79
4.25
NA
NA
NA
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uB
5.64
2.87
3.99
NA
NA
3.76
NA
NA
NA
9.13
6.32
2.16
2.95
NA
14.02
20.21
2.69
NA
NA
NA
NA
NA
NA
10.46
2.54
NA
NA
NA
Dearborn, MI
(DEMI)
5.44
3.59
3.61
NA
NA
3.86
NA
NA
NA
5.40
3.41
4.69
3.06
2.98
11.85
5.10
3.09
NA
NA
NA
NA
NA
NA
4.87
2.80
NA
NA
NA
Elizabeth, NJ
(ELNJ)
14.12
7.71
7.43
NA
NA
6.35
NA
NA
NA
13.83
6.87
4.39
6.49
NA
14.97
9.34
5.11
NA
NA
NA
NA
NA
NA
9.76
3.78
NA
3.95
9.79
-------
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
cis- 1 ,2-Dichloroethylene
fra«5-l,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl fer/-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fert-Butyl Ether
^-Octane
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
rrichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
Average
110.32
10.85
5.35
13.47
18.25
4.27
10.19
5.57
NA
5.35
19.51
8.68
9.59
18.41
18.31
9.49
4.45
9.60
84.94
8.01
4.67
24.80
8.84
30.32
12.06
3.48
5.28
5.64
Barceloneta, PR
(BAPR)
NA
NA
4.41
NA
NA
NA
5.11
NA
NA
3.47
NA
18.78
7.15
NA
17.82
8.32
6.00
10.42
NA
4.61
3.00
NA
10.12
NA
NA
4.47
4.49
2.79
Bountiful, UT
(BTUT)
NA
NA
3.27
20.08
NA
NA
7.94
NA
NA
2.90
NA
4.82
5.16
NA
NA
4.12
4.75
5.02
NA
4.32
3.17
NA
1.74
NA
2.31
3.64
3.87
3.03
Deer Park , TX
(CAMS 35)
NA
23.57
5.57
9.57
5.57
5.82
8.97
5.57
NA
5.13
NA
5.53
7.31
9.89
6.02
10.84
4.34
7.46
NA
9.03
4.04
NA
5.35
NA
6.84
4.01
3.58
4.38
Karnack , TX
(CAMS 85)
NA
NA
NA
NA
NA
NA
23.57
NA
NA
4.16
NA
4.61
NA
NA
NA
13.47
NA
10.10
NA
NA
2.56
NA
23.57
NA
NA
2.28
7.07
NA
Camden, NJ
(CANJ)
NA
NA
3.64
NA
NA
NA
12.90
NA
NA
7.64
NA
6.19
6.50
NA
7.03
11.71
2.55
10.82
NA
7.12
6.34
NA
8.80
NA
9.79
2.49
5.50
11.25
Chester, NJ
(CHNJ)
129.66
NA
5.58
NA
NA
NA
4.97
NA
NA
5.52
32.07
21.12
7.78
NA
25.67
14.11
6.68
13.60
NA
6.92
6.67
25.34
9.27
NA
13.30
4.06
10.05
16.02
tt
°6T
!• M
o S
>> Z
£^
NA
NA
7.65
NA
NA
NA
22.69
NA
NA
6.60
NA
5.93
6.43
8.21
NA
12.39
3.72
5.54
NA
6.13
5.85
NA
11.15
24.77
11.67
4.71
4.57
2.76
0
-------
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Average
Average
7.59
24.40
5.87
5.54
9.21
a.
ft
0)
O mS
O PH
M &
5.39
NA
2.93
3.09
10.16
H
P
Ja p1
"H P
M S
3.11
14.20
2.94
3.53
8.99
*
^ ^ ^
X ">
J^ t/3
L! s
I ^
p B
6.88
5.56
4.31
5.65
11.13
H ^ ^
.* 90
eS ^
F *5
Is <
NA
NA
1.64
4.16
9 42
^
Z
•V
§ Q
a ^
1 ^
u B
14.22
20.71
4.78
7.18
10.52
_,
Z
•V
aj h^A
tc ^
a M
s ^
8.36
NA
13.63
12.89
17.54
0
b-d^
£ w
® Z
4.74
9.53
5.61
4.87
11.47
P
&T '^
v 5o
5« ^
u B
15.39
26.94
10.51
5.03
7.96
hH
s
E ^
o C"
•es
pe
2.98
NA
3.25
3.76
5.33
Z
•V
D C^
"« Z
gj hJ
w &
4.98
NA
4.08
6.23
7.80
OJ
oo
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
ter^-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
Average
9. 21
4.52
6.75
32.68
40.62
5.44
NA
28.69
37.12
7.90
o
y Q
§ M
,3 U
"9 e.H
•§&
S* (-1
- o
O U
4.90
3.72
4.84
77.30
NA
4.15
NA
52.89
NA
7.39
in
§
1®
1-^
•3 s^
5^
2.84
2.64
5.11
14.90
63.94
4.75
NA
NA
NA
8.80
Z
H
•N ^_^^
o Z
•a H
s a
3d
4.57
4.10
6.03
5.39
NA
4.58
NA
NA
3.93
5.47
Z
H
a ^
0 £
•a H
s j«
2^
20.79
5.09
6.68
NA
63.94
5.89
NA
NA
NA
16.19
-J
j-f
o
S
* '"T"
a d
t: M
o S
Z O
27.98
7.52
15.04
0.76
NA
7.01
NA
27.32
88.01
5.82
X
(j
1^
a ^
Sg
«|
^ °
OJ Hj
Z Z
23.98
3.33
5.91
49.71
NA
5.47
NA
NA
NA
8.75
SI
•<
H* ^^
'3 ^
S !/5
0 M
* £
a- fe
6.36
2.57
8.29
NA
NA
8.97
NA
NA
12.57
9.07
O
^
fo
hH^ ^
^ S
14.47
3.59
2.54
NA
NA
2.47
NA
NA
NA
4.81
.
^
£|
2 r^
<% S
7.48
5.89
12.88
39.36
NA
6.06
NA
NA
NA
5.57
P
IM
CS
13 ¥
ci s
15.73
6.28
5.16
NA
NA
5.49
NA
NA
NA
12.06
-------
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1, 1-Dichloroethene
cis- 1 ,2-Dichloroethylene
trans- 1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 , 3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tert-Butyl Ether
Average
6.32
4.59
5.47
24.28
10.69
9.21
3.94
8.59
86.70
52.47
NA
35.39
19.97
9.62
3.50
39.93
14.39
9.79
110.32
10.85
5.35
13.47
18.25
4.27
10.19
5.57
NA
Grand Junction,
CO (GPCO)
3.67
2.90
5.78
27.50
7.31
4.75
3.28
NA
91.96
NA
NA
NA
NA
4.47
3.29
NA
3.95
NA
90.99
NA
3.42
NA
NA
NA
2.64
NA
NA
Gulfport, MS
(GPMS)
3.95
3.55
3.81
NA
10.87
10.79
2.51
NA
NA
NA
NA
59.25
NA
3.61
2.41
14.18
NA
NA
NA
NA
3.78
NA
NA
NA
4.08
NA
NA
Loudon, TN
(LDTN)
10.14
3.39
3.22
NA
12.66
2.59
3.11
NA
50.74
40.90
NA
41.53
NA
9.31
3.04
NA
NA
NA
NA
NA
4.74
NA
NA
NA
14.95
NA
NA
Loudon, TN
(MSTN)
5.85
3.19
5.48
NA
6.33
11.88
4.89
8.59
NA
NA
NA
NA
NA
3.81
4.67
NA
NA
NA
NA
NA
8.10
10.76
NA
NA
5.91
NA
NA
Northbrook, IL
(NBIL)
10.14
6.92
5.11
NA
9.97
17.80
3.82
NA
NA
25.84
NA
NA
NA
11.51
4.36
NA
10.15
NA
NA
NA
7.33
NA
NA
NA
5.13
NA
NA
New Brunswick,
NJ (NBNJ)
9.87
3.37
5.75
NA
18.04
8.02
3.29
NA
NA
78.18
NA
NA
NA
17.03
3.42
NA
9.34
NA
NA
NA
5.05
NA
NA
NA
14.89
NA
NA
Phoenix, AZ
(PXSS)
4.01
3.58
5.89
NA
4.73
4.46
2.48
NA
NA
3.22
NA
26.69
2.72
7.38
1.93
NA
NA
NA
NA
NA
5.96
NA
30.93
2.73
22.26
NA
NA
O
S
j£
'§ o
jg
*%
8.48
2.26
2.07
NA
18.05
4.19
2.50
NA
NA
NA
NA
NA
NA
4.86
2.35
NA
NA
NA
NA
NA
5.47
NA
NA
NA
9.62
NA
NA
<
£
u3
S£
II
6.30
17.87
3.78
36.12
13.81
11.59
3.18
NA
NA
38.06
NA
NA
NA
7.71
3.11
48.52
NA
NA
NA
10.40
6.44
NA
NA
NA
14.88
NA
NA
0
!/5
»T
13
si
li
5.12
6.08
4.72
NA
9.43
4.36
6.52
NA
NA
NA
NA
41.53
NA
16.34
3.53
NA
NA
NA
NA
NA
7.07
NA
NA
NA
12.52
NA
NA
-------
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl fert-Butyl Ether
rc-Octane
Propylene
Styrene
1, 1,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
Vinyl chloride
w,/?-Xylene
o-Xylene
Average
Average
5.35
19.51
8.68
9.59
18.41
18.31
9.49
4.45
9.60
84.94
8.01
4.67
24.80
8.84
30.32
12.06
3.48
5.28
5.64
7.59
24.40
5.87
5.54
9.21
Grand Junction,
CO (GPCO)
3.94
6.95
4.28
6.23
30.59
51.33
5.43
2.97
2.36
NA
4.39
3.69
NA
3.98
NA
5.03
3.19
2.73
3.48
5.33
NA
3.83
3.72
14.11
Gulfport, MS
(GPMS)
4.60
NA
6.42
5.96
NA
30.84
4.15
2.89
3.73
NA
5.65
3.88
NA
4.56
9.43
NA
2.25
3.02
4.27
6.62
NA
3.98
4.85
9.25
Loudon, TN
(LDTN)
5.86
NA
5.53
7.90
26.00
NA
7.87
4.22
5.09
NA
8.00
3.20
NA
9.53
NA
25.32
3.16
3.52
6.42
10.72
9.43
5.75
6.88
10.23
Loudon, TN
(MSTN)
5.57
NA
5.14
6.04
NA
NA
19.81
4.60
4.68
84.94
13.31
4.43
NA
6.32
NA
7.13
4.80
5.47
2.05
3.89
71.65
3.42
4.55
12.66
Northbrook, IL
(NBIL)
13.65
NA
18.49
25.30
NA
NA
3.83
6.45
17.73
NA
8.75
9.77
NA
6.72
NA
14.66
5.44
4.30
13.03
12.67
38.38
12.34
11.21
14.06
New Brunswick,
NJ (NBNJ)
6.36
NA
17.79
9.41
NA
NA
5.16
3.56
7.03
NA
11.09
4.50
NA
6.97
14.08
11.87
3.38
13.94
4.73
8.77
NA
4.80
5.76
11.79
Phoenix, AZ
(PXSS)
9.15
NA
6.82
7.88
NA
NA
6.86
2.09
5.75
NA
8.31
10.84
7.65
9.03
NA
4.90
2.51
3.07
8.87
7.52
28.55
9.47
8.25
8.32
O
s
j£
'§ o
jg
*%
2.41
NA
2.47
5.74
NA
56.66
12.43
2.85
7.62
NA
6.85
2.72
41.42
6.49
NA
47.04
1.94
2.58
2.11
12.40
59.27
1.45
2.50
10.73
<
£
u3
S£
II
8.43
NA
14.15
9.52
NA
NA
10.58
5.79
14.74
NA
10.55
7.51
NA
7.78
51.26
11.59
3.75
4.00
6.48
7.52
48.25
14.06
8.68
14.31
Q
!/5
»T
13
si
li
7.85
NA
6.06
12.28
NA
NA
23.69
4.44
12.12
NA
14.59
4.49
NA
9.78
NA
NA
3.57
5.06
4.79
9.11
NA
6.07
5.42
9.40
OJ
oo
-------
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
OJ
oo
Pollutant
Acetonitrile
Acetylene
Acrolein
Acrylonitrile
tert-Amyl Methyl Ether
Benzene
Bromochloromethane
Bromodichloromethane
Bromoform
Bromomethane
1,3 -Butadiene
Carbon disulfide
Carbon Tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chloromethylbenzene
Chloroprene
Dibromochloromethane
1 ,2-Dibromoethane
w-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
Average
9. 21
4.52
6.75
32.68
40.62
5.44
NA
28.69
37.12
7.90
6.32
4.59
5.47
24.28
10.69
9.21
3.94
8.59
86.70
52.47
NA
35.39
19.97
9.62
3.50
&
a.
sS _
3£
aft
<% Q
4.05
2.61
3.87
NA
NA
5.52
NA
NA
NA
2.76
2.45
1.42
2.17
NA
13.11
6.95
1.52
NA
NA
NA
NA
NA
NA
3.25
2.45
Schiller Park IL
(SPIL)
8.65
6.27
8.11
NA
NA
5.72
NA
NA
NA
8.54
7.66
3.73
3.14
NA
10.41
4.60
6.21
NA
85.85
NA
NA
NA
NA
6.99
6.23
Tulsa, OK
(TOOK)
3.70
3.51
3.00
NA
NA
3.97
NA
NA
56.44
9.00
4.91
2.11
5.01
NA
11.48
3.14
2.68
NA
117.87
NA
NA
NA
NA
6.43
2.24
tt
°,£
eS Q
•1°
£b
5.37
3.70
15.70
8.64
29.49
3.96
NA
NA
NA
5.48
5.63
5.70
5.02
NA
12.74
1.41
5.43
NA
NA
78.18
NA
NA
20.02
11.95
4.17
Tulsa, OK
(TUOK)
5.00
10.15
6.22
6.00
19.53
4.99
NA
NA
NA
4.15
7.32
5.14
7.57
61.09
11.15
2.28
7.38
NA
NA
NA
NA
NA
NA
2.44
4.64
!/5
g
if
Ib
14.88
3.94
3.62
NA
NA
5.46
NA
NA
NA
11.16
10.53
3.07
2.78
NA
7.99
8.87
3.27
NA
NA
NA
NA
NA
NA
9.38
3.15
-------
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
OJ
oo
Pollutant
1 ,2-Dibromoethane
OT-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
cis- 1 ,2-Dichloroethylene
fra«5-l,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
cis- 1 , 3 -D ichloropropene
trans- 1 ,3 -Dichloropropene
Dichlorotetrafluoroethane
Ethyl Aery late
Ethyl tert-Butyl Ether
Ethylbenzene
Hexachloro- 1 ,3 -butadiene
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl tert-Butyl Ether
w-Octane
Propylene
Styrene
Average
NA
35.39
19.97
9.62
3.50
39.93
14.39
9.79
110.32
10.85
5.35
13.47
18.25
4.27
10.19
5.57
NA
5.35
19.51
8.68
9.59
18.41
18.31
9.49
4.45
9.60
&
0.
sS _
3£
aft
<% Q
NA
NA
NA
3.25
2.45
NA
NA
NA
NA
NA
2.14
NA
NA
NA
2.38
NA
NA
3.42
NA
2.81
7.04
NA
3.84
5.38
3.41
3.65
Schiller Park IL
(SPIL)
NA
NA
NA
6.99
6.23
NA
NA
NA
NA
NA
3.50
NA
NA
NA
5.21
NA
NA
2.24
NA
26.87
24.62
NA
NA
3.28
6.79
6.86
tt
0 S?
ef O
•io
£b
NA
NA
NA
6.43
2.24
NA
NA
NA
NA
NA
5.04
NA
NA
NA
6.52
NA
NA
4.34
NA
3.88
3.80
8.68
6.55
5.49
3.61
5.90
tt
go
•3 ^
£b
NA
NA
20.02
11.95
4.17
NA
3.95
NA
NA
8.46
3.27
NA
NA
NA
8.00
NA
NA
3.13
NA
3.91
5.61
27.09
6.80
5.83
4.28
11.45
Tulsa, OK
(TUOK)
NA
NA
NA
2.44
4.64
NA
11.38
NA
NA
NA
11.18
NA
NA
NA
17.08
NA
NA
3.29
NA
5.47
6.69
NA
3.20
5.83
5.58
17.34
Tupelo, MS
(TUMS)
NA
NA
NA
9.38
3.15
48.52
63.80
NA
NA
NA
7.18
NA
NA
NA
11.32
NA
NA
3.42
NA
2.81
7.04
NA
3.84
5.38
3.41
3.65
-------
oo
oo
Table 31-55. VOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
Propylene
Styrene
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
rrichlorofluoromethane
rrichlorotrifluoroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Vinyl chloride
m,p-Xylene
o-Xylene
Average
Average
4.45
9.60
84.94
8.01
4.67
24.80
8.84
30.32
12.06
3.48
5.28
5.64
7.59
24.40
5.87
5.54
9.21
&
a.
sS _
3£
aft
<% S
3.41
3.65
NA
5.81
4.64
NA
12.80
NA
23.57
1.60
1.93
2.40
3.46
NA
3.55
4.20
4.69
Schiller Park IL
(SPIL)
6.79
6.86
NA
2.23
2.68
NA
7.71
NA
4.44
4.93
3.94
4.75
5.25
NA
2.05
2.99
9.14
tt
0 S?
ef O
•io
£b
3.61
5.90
NA
13.98
4.58
NA
7.88
51.26
5.40
2.50
12.53
5.21
4.19
14.28
4.20
3.32
11.31
X
go
•3 &>
£b
4.28
11.45
NA
7.37
4.55
NA
11.04
4.68
6.20
4.77
2.86
4.83
5.87
5.44
15.11
4.33
9.55
Tulsa, OK
(TUOK)
5.58
17.34
NA
10.21
3.22
NA
16.59
24.77
7.55
4.40
4.59
3.52
9.64
7.33
3.94
6.14
9. 32
Tupelo, MS
(TUMS)
3.41
3.65
NA
5.81
4.64
NA
12.80
NA
23.57
1.60
1.93
2.40
3.46
NA
3.55
4.20
4.69
-------
31.2.2 SNMOC Analytical Precision
Table 31-56 presents analytical precision results from replicate analyses of all duplicate
and collocated SNMOC samples. The average concentration differences observed for replicate
analyses of SNMOC ranged from 0.01 (cw-2-pentene) to 2.50 (TNMOC) ppbC. For most of the
pollutants, the SNMOC analytical precision was within the program DQO of 15 percent. The
overall average variability was 10.81 percent.
Table 31-56. SNMOC Analytical Precision: 112 Replicate Analyses
for all Duplicate and Collocated Samples
Pollutant
Acetylene
Benzene
1,3 -Butadiene
^-Butane
c/s-2-Butene
fra«s-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
rc-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
rc-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
^-Heptane
1-Heptene
rc-Hexane
1-Hexene
c/s-2-Hexene
fra»s-2-Hexene
Isobutane
lsobutene/1 -Butene
Number of
Observations
112
112
74
108
101
108
112
112
21
107
0
76
31
103
104
109
107
101
51
112
112
0
112
104
86
100
111
94
110
96
6
5
112
80
Average RPD
(%)
2.89
4.67
16.21
1.68
14.62
7.82
7.47
10.37
21.47
11.98
NA
24.80
42.74
10.40
7.13
10.78
8.70
16.00
23.11
0.83
12.23
NA
1.97
6.98
25.88
18.06
6.66
21.26
6.12
27.98
56.70
36.85
2.08
8.05
Average
Concentration
Difference (ppbC)
0.05
0.06
0.02
0.07
0.02
0.02
0.02
0.02
0.07
0.04
NA
0.05
0.07
0.02
0.02
0.03
0.02
0.04
0.06
0.07
0.05
NA
0.05
0.02
0.04
0.03
0.03
0.04
0.06
0.05
0.09
0.07
0.04
0.15
Coefficient of
Variation (%)
2.05
3.30
11.46
1.19
10.34
5.53
5.28
7.33
15.18
8.47
NA
17.54
30.22
7.36
5.04
7.62
6.15
11.31
16.34
0.59
8.65
NA
1.39
4.94
18.30
12.77
4.71
15.03
4.33
19.78
40.09
26.06
1.47
5.69
31-89
-------
Table 31-56. SNMOC Analytical Precision: 112 Replicate Analyses
for all Duplicate and Collocated Samples (Continued)
Pollutant
Isopentane
Isoprene
Isopropylbenzene
2-Methyl- 1 -butene
2-Methyl-2-butene
3 -Methyl- 1 -butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3-Methylhexane
3-Methylpentane
2-Methylpentane
4-Methyl- 1 -pentene
2-Methyl- 1 -pentene
rc-Nonane
1-Nonene
rc-Octane
1-Octene
rc-Pentane
1 -Pentene
c/s-2-Pentene
trans-2-Pentene
a-Pinene
&-Pinene
Propane
rc-Propy Ibenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1,2,3 -Trimethy Ibenzene
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
2,2,3-Trimethylpentane
2,2,4-Trimethylpentane
2,3,4-Trimethylpentane
rc-Undecane
1-Undecene
m -Xylene/^-Xy lene
o-Xylene
Number of
Observations
92
101
53
96
78
12
103
112
80
87
81
112
112
110
1
18
109
47
112
60
112
108
70
97
85
26
112
94
112
0
33
112
112
112
15
0
82
112
80
70
112
111
110
31
112
112
Average RPD
(%)
2.70
7.89
15.16
8.16
11.23
10.13
10.80
5.57
26.05
14.53
18.38
8.64
5.22
7.48
128.86
11.02
7.99
42.76
5.56
23.21
2.08
4.99
9.55
12.37
20.91
9.25
1.13
18.94
2.89
NA
31.35
1.52
2.11
3.30
27.45
NA
19.36
7.37
13.97
27.35
4.68
9.09
14.01
57.44
8.00
6.56
Average
Concentration
Difference (ppbC)
0.28
0.03
0.02
0.02
0.03
0.07
0.04
0.02
0.05
0.02
0.08
0.04
0.03
0.09
0.19
0.02
0.02
0.07
0.02
0.03
0.07
0.02
0.01
0.02
0.14
0.10
0.09
0.03
0.03
NA
0.15
1.14
2.50
0.12
0.06
NA
0.03
0.03
0.03
0.04
0.04
0.03
0.05
0.06
0.07
0.03
Coefficient of
Variation (%)
1.91
5.58
10.72
5.77
7.94
7.16
7.64
4.01
18.42
10.27
13.00
6.11
3.54
5.29
91.12
7.79
5.65
30.67
3.93
16.41
1.47
3.53
6.75
8.75
14.79
6.54
0.80
13.39
2.04
NA
22.17
1.07
1.49
2.33
19.41
NA
13.69
5.21
9.88
19.34
3.42
6.43
9.90
40.62
5.66
4.64
31-90
-------
Table 31-57 presents analytical precision results from SNMOC replicate analyses for all
of the duplicate samples. These results show low- to high-level variability, ranging from 0.56
percent (ethane) to 91.12 percent (4-methyl-l-pentene). The overall average variability was
10.47 percent. For SNMOC, there was only one collocated site, NBIL. The SNMOC precision
data for the replicate samples at NBIL is shown in Table 31-59.
Table 31-57. SNMOC Analytical Precision: 96 Replicate Analyses
for all Duplicate Samples
Pollutant
Acetylene
Benzene
1,3 -Butadiene
rc-Butane
c/s-2-Butene
fra»s-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
rc-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethy Ibutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
rc-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
^-Heptane
1-Heptene
rc-Hexane
1-Hexene
c/s-2-Hexene
fra«s-2-Hexene
Isobutane
lsobutene/1 -Butene
Isopentane
Isoprene
Number of
Observations
96
96
66
92
90
92
96
96
16
92
0
62
25
90
88
93
91
87
43
96
96
0
96
88
73
86
95
83
94
87
5
5
96
70
76
90
Average RPD
(%)
2.83
4.95
13.49
1.58
12.01
6.63
7.74
8.30
17.05
13.65
NA
28.57
48.73
8.10
7.36
9.93
9.73
17.67
23.29
0.79
12.45
NA
2.15
6.62
26.26
12.14
6.85
18.59
6.90
22.69
26.48
36.85
1.94
7.68
2.77
5.15
Average
Concentration
Difference (ppbC)
0.05
0.07
0.02
0.07
0.02
0.02
0.03
0.02
0.08
0.04
NA
0.06
0.07
0.02
0.02
0.03
0.02
0.05
0.06
0.05
0.05
NA
0.06
0.02
0.05
0.03
0.03
0.04
0.07
0.04
0.05
0.07
0.03
0.16
0.31
0.03
Coefficient of
Variation (%)
2.00
3.50
9.54
1.12
8.49
4.69
5.47
5.87
12.05
9.65
NA
20.20
34.45
5.73
5.20
7.02
6.88
12.50
16.47
0.56
8.80
NA
1.52
4.68
18.57
8.58
4.84
13.14
4.88
16.04
18.72
26.06
1.37
5.43
1.96
3.64
31-91
-------
Table 31-57. SNMOC Analytical Precision: 96 Replicate Analyses
for all Duplicate Samples (Continued)
Pollutant
Isopropylbenzene
2-Methyl- 1 -butene
2-Methyl-2-butene
3 -Methyl- 1 -butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3-Methylhexane
3-Methylpentane
2-Methylpentane
4-Methyl- 1 -pentene
2-Methyl- 1 -pentene
rc-Nonane
1-Nonene
rc-Octane
1-Octene
rc-Pentane
1 -Pentene
c/s-2-Pentene
trans-2-Pentene
a-Pinene
&-Pinene
Propane
rc-Propy Ibenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1,2,3 -Trimethy Ibenzene
1 ,2,4-Trimethy Ibenzene
1,3,5 -Trimethy Ibenzene
2,2,3-Trimethylpentane
2,2,4-Trimethylpentane
2,3 ,4-Trimethylpentane
rc-Undecane
1-Undecene
w-Xylene/^-Xylene
o-Xylene
Number of
Observations
45
80
66
12
87
96
68
75
69
96
96
94
1
18
93
41
96
56
96
92
60
85
71
20
96
80
96
0
29
96
96
96
13
0
72
96
69
60
96
95
96
26
96
96
Average RPD
(%)
16.63
7.21
10.55
10.13
12.58
6.09
30.59
14.64
14.27
8.37
5.55
8.08
128.86
11.02
7.86
33.13
5.65
15.20
2.14
5.29
10.15
13.42
22.76
8.25
0.94
17.33
3.09
NA
33.41
1.52
2.14
3.60
31.23
NA
22.69
6.99
15.09
30.56
5.45
10.61
16.27
61.08
9.03
7.27
Average
Concentration
Difference (ppbC)
0.02
0.02
0.03
0.07
0.04
0.03
0.06
0.02
0.07
0.04
0.03
0.09
0.19
0.02
0.02
0.05
0.02
0.02
0.08
0.03
0.02
0.02
0.12
0.10
0.08
0.03
0.03
NA
0.18
1.18
2.79
0.15
0.07
NA
0.03
0.03
0.03
0.05
0.04
0.03
0.06
0.06
0.08
0.03
Coefficient of
Variation (%)
11.76
5.10
7.46
7.16
8.89
4.31
21.63
10.35
10.09
5.92
3.70
5.71
91.12
7.79
5.56
23.98
3.99
10.75
1.51
3.74
7.17
9.49
16.10
5.83
0.67
12.26
2.19
NA
23.62
1.08
1.51
2.54
22.09
NA
16.04
4.94
10.67
21.61
3.95
7.50
11.50
43.19
6.38
5.14
31-92
-------
Due to the focus on QA for the NATTS program, Tables 31-58 and 31-59 present the
analytical precision results from SNMOC replicate analyses for all the duplicate and collocated
samples at NATTS sites (BTUT and NBIL), respectively. Shaded rows present results for the
NATTS core compounds. These results show low- to high-level variability at these sites, as
represented by CV, ranging from 0.25 percent (for propane at BTUT) to 91.12 percent (for 4-
methyl-1-pentene at BTUT), with an average of 8.57 percent. This is within the 15 percent
program DQO.
Table 31-58. SNMOC Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Bountiful, UT (BTUT)
Pollutant
Acetylene
Benzene
1,3 -Butadiene
^-Butane
c/s-2-Butene
trans-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
rc-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
rc-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
^-Heptane
1-Heptene
rc-Hexane
1-Hexene
c/s-2-Hexene
fra«s-2-Hexene
Number of
Observations
24
24
24
24
24
24
24
24
4
24
0
15
12
24
24
24
24
24
15
24
24
0
24
24
24
24
24
23
24
23
4
4
Average RPD
(%)
1.30
3.75
8.27
1.04
4.42
4.80
2.42
4.47
11.98
8.91
NA
26.94
8.19
4.64
2.80
3.82
3.42
9.94
32.12
0.38
4.67
NA
1.71
4.63
10.62
6.32
3.62
27.74
3.33
19.24
13.35
2.99
Average
Concentration
Difference (ppbC)
0.06
0.12
0.02
0.13
0.01
0.02
0.03
0.02
0.04
0.06
NA
0.06
0.01
0.02
0.02
0.04
0.02
0.03
0.07
0.04
0.05
NA
0.13
0.03
0.03
0.02
0.06
0.09
0.12
0.03
0.02
0.01
Coefficient of
Variation (%)
0.92
2.65
5.85
0.74
3.12
3.39
1.71
3.16
8.47
6.30
NA
19.05
5.79
3.28
1.98
2.70
2.42
7.03
22.71
0.27
3.30
NA
1.21
3.28
7.51
4.47
2.56
19.62
2.36
13.61
9.44
2.11
31-93
-------
Table 31-58. SNMOC Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Bountiful, UT (BTUT) (Continued)
Pollutant
Isobutane
lsobutene/1 -Butene
Isopentane
Isoprene
Isopropy Ibenzene
2-Methyl- 1 -butene
2-Methyl-2-butene
3 -Methyl- 1 -butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3 -Methy Ihexane
3-Methylpentane
2-Methylpentane
4-Methyl- 1 -pentene
2-Methyl- 1 -pentene
rc-Nonane
1-Nonene
^-Octane
1-Octene
rc-Pentane
1 -Pentene
c/s-2-Pentene
trans-1 -Pentene
a-Pinene
&-Pinene
Propane
rc-Propy Ibenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1,2,3 -Trimethy Ibenzene
1 ,2,4-Trimethylbenzene
1,3,5 -Trimethy Ibenzene
2,2,3-Trimethylpentane
2,2,4-Trimethylpentane
2,3 ,4-Trimethylpentane
rc-Undecane
Number of
Observations
24
24
16
24
16
24
20
4
24
24
24
24
24
24
24
24
1
16
24
15
24
18
24
24
21
24
18
4
24
24
24
0
4
24
24
24
2
0
24
24
24
24
24
24
24
Average RPD
(%)
0.57
6.04
2.46
3.75
9.43
5.36
11.63
12.22
3.17
2.16
12.67
5.48
5.08
3.13
2.21
2.24
128.86
11.02
4.06
24.55
3.25
14.04
1.28
2.06
5.29
5.27
13.17
13.92
0.35
9.23
2.05
NA
57.27
0.85
2.73
2.75
20.00
NA
9.38
3.09
5.74
12.47
3.73
6.19
10.91
Average
Concentration
Difference (ppbC)
0.06
0.13
0.43
0.04
0.01
0.02
0.04
0.12
0.06
0.02
0.03
0.02
0.06
0.03
0.04
0.08
0.19
0.02
0.02
0.04
0.02
0.04
0.08
0.06
0.01
0.02
0.07
0.18
0.11
0.02
0.05
NA
0.30
1.37
4.74
0.23
0.04
NA
0.02
0.03
0.02
0.04
0.08
0.03
0.06
Coefficient of
Variation (%)
0.40
4.27
1.74
2.65
6.67
3.79
8.23
8.64
2.24
1.41
8.96
3.87
3.59
2.21
1.29
1.59
91.12
7.79
2.87
19.33
2.30
9.93
0.91
1.46
3.74
3.73
9.31
9.84
0.25
6.53
1.45
NA
40.50
0.60
1.93
1.94
14.14
NA
6.63
2.19
4.06
8.82
2.23
4.38
7.71
31-94
-------
Table 31-58. SNMOC Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Bountiful, UT (BTUT) (Continued)
Pollutant
1-Undecene
m -Xy lene/^-Xy lene
o-Xylene
Number of
Observations
14
24
24
Average RPD
(%)
11.15
5.07
3.25
Average
Concentration
Difference (ppbC)
0.01
0.14
0.04
Coefficient of
Variation (%)
7.88
3.58
2.30
Table 31-59. SNMOC Analytical Precision: 16 Replicate Analyses
for Collocated Samples for Northbrook, IL (NBIL)
Pollutant
Acetylene
Benzene
1,3 -Butadiene
^-Butane
c/s-2-Butene
trans-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
rc-Decane
1-Decene
w-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3-Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
rc-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
^-Heptane
1-Heptene
rc-Hexane
1-Hexene
c/s-2-Hexene
fra«s-2-Hexene
Isobutane
Isobutene/1 -Butene
Isopentane
Number of
Observations
16
16
8
16
11
16
16
16
5
15
0
14
6
13
16
16
16
14
8
16
16
0
16
16
13
14
16
11
16
9
1
0
16
10
16
Average RPD
(%)
3.16
3.56
27.09
2.06
25.09
12.60
6.41
18.65
39.18
5.32
NA
9.73
18.78
19.60
6.23
14.16
4.57
9.29
22.38
1.03
11.37
NA
1.25
8.44
24.34
41.73
5.90
31.95
3.02
49.14
117.15
NA
2.64
9.54
2.43
Average
Concentration
Difference (ppbC)
0.06
0.03
0.02
0.07
0.02
0.02
0.01
0.03
0.07
0.02
NA
0.02
0.04
0.03
0.01
0.03
0.01
0.02
0.02
0.14
0.03
NA
0.03
0.01
0.04
0.05
0.03
0.03
0.02
0.08
0.18
NA
0.05
0.10
0.15
Coefficient of
Variation (%)
2.23
2.52
19.15
1.46
17.74
8.91
4.54
13.18
27.71
3.76
NA
6.88
13.28
13.86
4.40
10.01
3.23
6.57
15.83
0.73
8.04
NA
0.89
5.97
17.21
29.51
4.17
22.60
2.13
34.75
82.84
NA
1.87
6.75
1.72
31-95
-------
Table 31-59. SNMOC Analytical Precision: 16 Replicate Analyses
for Collocated Samples for Northbrook, IL (NBIL) (Continued)
Pollutant
Isoprene
Isopropy Ibenzene
2-Methyl- 1 -butene
2-Methyl-2-butene
3 -Methyl- 1 -butene
Methylcyclohexane
Methylcyclopentane
2-Methylheptane
3-Methylheptane
2-Methylhexane
3-Methylhexane
3-Methylpentane
2-Methylpentane
4-Methyl- 1 -pentene
2-Methyl- 1 -pentene
rc-Nonane
1-Nonene
^-Octane
1-Octene
rc-Pentane
1 -Pentene
c/s-2-Pentene
trans-2-Pentene
a-Pinene
&-Pinene
Propane
rc-Propy Ibenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
rc-Tridecane
1-Tridecene
1,2,3 -Trimethy Ibenzene
1 ,2,4-Trimethy Ibenzene
1,3,5 -Trimethy Ibenzene
2,2,3-Trimethylpentane
2,2,4-Trimethylpentane
2,3 ,4-Trimethylpentane
rc-Undecane
1-Undecene
w-Xylene/^-Xylene
o-Xylene
Number of
Observations
11
8
16
12
0
16
16
12
12
12
16
16
16
0
0
16
6
16
4
16
16
10
12
14
6
16
14
16
0
4
16
16
16
2
0
10
16
11
10
16
16
14
5
16
16
Average RPD
(%)
18.83
9.28
11.95
13.98
NA
3.69
3.48
7.89
14.09
34.82
9.71
3.87
5.10
NA
NA
8.53
81.27
5.24
55.25
1.87
3.80
7.16
8.16
13.52
12.26
1.89
25.35
2.07
NA
23.13
1.50
2.02
2.12
16.09
NA
6.08
8.89
9.46
14.51
1.62
3.00
4.96
46.51
3.89
3.70
Average
Concentration
Difference (ppbC)
0.01
0.01
0.02
0.03
NA
0.01
0.02
0.01
0.03
0.12
0.05
0.02
0.08
NA
NA
0.01
0.13
0.02
0.06
0.02
0.01
0.01
0.01
0.20
0.10
0.11
0.03
0.01
NA
0.03
1.00
1.33
0.04
0.01
NA
0.01
0.02
0.02
0.02
0.02
0.01
0.01
0.07
0.02
0.01
Coefficient of
Variation (%)
13.31
6.56
8.45
9.89
NA
2.61
2.81
5.58
9.96
24.62
6.87
2.91
3.60
NA
NA
6.03
57.47
3.71
39.07
1.32
2.68
5.06
5.77
9.56
8.67
1.33
17.93
1.46
NA
16.35
1.06
1.43
1.50
11.38
NA
4.30
6.29
6.69
10.26
1.28
2.12
3.51
32.89
2.75
2.62
31-96
-------
Table 31-60 presents the average CV per pollutant, per pollutant per site, per site, and the
overall average CV for all UATMP and NATTS sites sampling SNMOC. The average site CV
ranged from 6.74 percent at BTUT to 12.72 percent at SFSD, with an overall program average
CV of 10.81 percent. This overall average variability is within the 15 percent CV program
DQO.
Table 31-60. SNMOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site
Pollutant
Acetylene
Benzene
1,3 -Butadiene
w-Butane
c/s-2-Butene
trans-2-Butene
Cyclohexane
Cyclopentane
Cyclopentene
w-Decane
1-Decene
OT-Diethylbenzene
p-Diethylbenzene
2,2-Dimethylbutane
2,3 -Dimethylbutane
2,3 -Dimethylpentane
2,4-Dimethylpentane
w-Dodecane
1-Dodecene
Ethane
Ethylbenzene
2-Ethyl-l-butene
Ethylene
w-Ethyltoluene
o-Ethyltoluene
p-Ethyltoluene
w-Heptane
1-Heptene
w-Hexane
1-Hexene
c/s-2-Hexene
Jrans-2-Hexene
Isobutane
Average
2.05
3.30
11.46
1.19
10.34
5.53
5.28
7.33
15.18
8.47
NA
17.54
30.22
7.36
5.04
7.62
6.15
11.31
16.34
0.59
8.65
NA
1.39
4.94
18.30
12.77
4.71
15.03
4.33
19.78
40.09
26.06
1.47
Bountiful, UT
(BTUT)
0.92
2.65
5.85
0.74
3.12
3.39
1.71
3.16
8.47
6.30
NA
19.05
5.79
3.28
1.98
2.70
2.42
7.03
22.71
0.27
3.30
NA
1.21
3.28
7.51
4.47
2.56
19.62
2.36
13.61
9.44
2.11
0.40
Custer, SD
(CUSD)
2.02
1.92
2.75
1.28
11.73
4.81
6.63
10.23
5.64
13.48
NA
14.31
11.17
7.30
9.91
9.41
7.33
19.00
9.65
0.38
12.67
NA
0.97
6.03
21.63
6.19
2.92
11.85
8.01
16.07
NA
NA
1.59
Gulfport, MS
(GPMS)
1.92
2.40
8.55
1.05
5.05
4.75
5.18
6.62
29.71
10.57
NA
15.98
32.57
5.33
3.80
8.01
9.93
9.18
24.30
0.47
6.50
NA
1.03
4.44
17.77
10.99
5.25
10.36
3.52
9.32
28.01
50.01
0.51
Northbrook, IL
(NBIL)
2.23
2.52
19.15
1.46
17.74
8.91
4.54
13.18
27.71
3.76
NA
6.88
13.28
13.86
4.40
10.01
3.23
6.57
15.83
0.73
8.04
NA
0.89
5.97
17.21
29.51
4.17
22.60
2.13
34.75
82.84
NA
1.87
0
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££
3.14
7.02
21.01
1.41
14.06
5.80
8.36
3.47
4.39
8.26
NA
31.47
88.29
7.02
5.11
7.95
7.85
14.79
9.21
1.10
12.72
NA
2.88
4.97
27.37
12.69
8.65
10.75
5.63
25.17
NA
NA
3.00
31-97
-------
Table 31-60. SNMOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
Isobutene/ 1 -Butene
Isopentane
Isoprene
Isopropylbenzene
Isopentane
Isoprene
Isopropylbenzene
2-Methyl- 1 -butene
2-Methyl-2-butene
2-Methylheptane
3-Methylheptane
2-Methylhexane
3-Methylhexane
3-Methylpentane
2-Methylpentane
4-Methyl-l-pentene
2-Methyl-l-pentene
w-Nonane
1-Nonene
w-Octane
1-Octene
w-Pentane
1-Pentene
c/s-2-Pentene
fra»s-2-Pentene
a-Pinene
&-Pinene
Propane
rc-Propylbenzene
Propylene
Propyne
Styrene
SNMOC
TNMOC (w/unknowns)
Toluene
w-Tridecane
1-Tridecene
1 ,2,3 -Trimethylbenzene
1 ,2,4-Trimethylbenzene
1 , 3 ,5 -Trimethylbenzene
2,2,3 -Trimethylpentane
2,2,4-Trimethylpentane
2,3,4-Trimethylpentane
Average
5.69
1.91
5.58
10.72
5.77
7.94
2.05
3.30
11.46
18.42
10.27
13.00
6.11
3.54
5.29
91.12
7.79
5.65
30.67
3.93
16.41
1.47
3.53
6.75
8.75
14.79
6.54
0.80
13.39
2.04
NA
22.77
7.07
1.49
2.33
19.41
NA
13. 69
5.21
9.88
19.34
3.42
6.43
Bountiful, UT
(BTUT)
4.27
1.74
2.65
6.67
3.79
8.23
0.92
2.65
5.85
8.96
3.87
3.59
2.21
1.29
1.59
91.12
7.79
2.87
19.33
2.30
9.93
0.91
1.46
3.74
3.73
9.31
9.84
0.25
6.53
1.45
NA
40.50
0.60
1.93
1.94
14.14
NA
6.63
2.19
4.06
8.82
2.23
4.38
Custer, SD
(CUSD)
6.49
1.92
4.35
15.79
7.55
8.95
2.02
1.92
2.75
16.51
11.01
15.56
7.38
3.29
7.61
NA
NA
6.44
12.64
5.94
4.37
0.85
2.57
8.83
9.70
12.93
2.36
0.18
12.75
1.70
NA
21.23
0.97
1.54
2.36
5.13
NA
12.71
8.47
11.80
23.69
3.79
6.52
Gulfport, MS
(GPMS)
6.43
2.05
2.54
21.22
3.16
10.34
1.92
2.40
8.55
22.79
9.38
12.97
6.90
2.73
9.93
NA
NA
5.00
30.03
3.65
5.15
2.42
4.41
8.21
7.02
24.46
5.30
0.60
8.02
1.25
NA
19.80
1.26
1.00
2.25
46.99
NA
7.82
3.94
13.27
33.42
4.96
5.90
Northbrook, IL
(NBIL)
6.75
1.72
13.31
6.56
8.45
9.89
2.23
2.52
19.15
5.58
9.96
24.62
6.87
2.91
3.60
NA
NA
6.03
57.47
3.71
39.07
1.32
2.68
5.06
5.77
9.56
8.67
1.33
17.93
1.46
NA
16.35
1.06
1.43
1.50
11.38
NA
4.30
6.29
6.69
10.26
1.28
2.12
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4.53
2.12
5.03
3.37
5.89
2.31
3.14
7.02
21.01
38.25
17.15
8.26
7.20
7.48
3.72
NA
NA
7.92
33.90
4.08
23.53
1.87
6.54
7.91
17.52
17.68
NA
1.64
21.72
4.35
NA
12.96
1.48
1.57
3.62
NA
NA
37.00
5.16
13.56
20.52
4.82
13.21
31-98
-------
Table 31-60. SNMOC Analytical Precision: Coefficient of Variation
for all Replicate Analyses, All Sites (Continued)
Pollutant
w-Undecane
1-Undecene
w-Xylene/^-Xylene
o-Xylene
Average
Average
9.90
40.62
5.66
4.64
10.81
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7.71
7.88
3.58
2.30
6.74
P
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11.07
NA
14.56
8.37
8.13
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31
19.64
11.08
2.49
2.60
10.15
HH
0
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z o
3.51
32.89
2.75
2.62
10.50
P
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CS
fe ^
H w
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Zfl ^^s
7.59
110.62
4.90
7.30
72.72
31.2.3 Carbonyl Compounds Analytical Precision
Table 31-61 presents the analytical precision results from replicate analyses of duplicate
and collocated samples, which shows that laboratory carbonyl analytical precision is within the
control limits of 15 percent CV. The overall average variability was 3.08 percent. In terms of
average concentration difference, the carbonyl precision ranged from 0.001 ppbv for
benzaldehyde to 0.02 ppbv for formaldehyde.
Table 31-61. Carbonyl Analytical Precision: 818 Replicate Analyses
for all Duplicate and Collocated Samples
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
818
818
818
818
818
9
818
806
175
814
801
812
Average RPD
(%)
0.65
0.65
3.60
2.48
3.06
21.81
0.79
3.71
5.22
2.97
4.19
3.21
Average
Concentration
Difference (ppbv)
0.01
0.01
0.001
0.003
0.002
0.004
0.02
0.002
0.002
0.003
0.002
0.002
Coefficient of
Variation (%)
0.46
0.46
2.55
1.75
2.17
15.42
0.56
2.62
3.69
2.10
2.96
2.27
31-99
-------
Table 31-62 shows analytical precision the results from replicate analyses of all
collocated carbonyl samples collected at DEMI, IDIN, INDEM, ININ, LDTN, MSTN, NBIL,
PXSS, SEW A, SPIL, TOOK, TSOK, TUOK, and WPIN. The analytical precision results from
collocated samples show variation for the pollutants ranging from 0.48 percent (acetone) to
37.26 percent (2,5-dimethylbenzaldehyde). The overall average variability was 4.83 percent.
Table 31-62. Carbonyl Analytical Precision: 408 Replicate Analyses
for all Collocated Samples
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
408
408
408
408
408
9
408
408
96
408
404
408
Average RPD
(%)
0.80
0.70
3.48
2.30
3.22
52.69
0.70
3.82
3.41
2.77
4.55
3.46
Average
Concentration
Difference (ppbv)
0.01
0.01
0.002
0.004
0.002
0.01
0.02
0.003
0.002
0.004
0.002
0.002
Coefficient of
Variation (%)
0.56
0.48
2.46
1.63
2.28
37.26
0.49
2.70
2.41
1.96
3.22
2.45
Table 31-63 shows the analytical precision results from replicate analyses of all duplicate
carbonyl samples. The analytical precision results from duplicate samples show variation for the
pollutants ranging from 0.37 percent (acetaldehyde) to 5.49 percent (isovaleraldehyde). The
overall average variability was 2.12 percent.
Table 31-63. Carbonyl Analytical Precision: 410 Replicate Analyses
for all Duplicate Samples
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Number of
Observations
410
410
410
410
Average RPD
(%)
0.52
0.62
3.90
2.40
Average
Concentration
Difference (ppbv)
0.01
0.01
0.001
0.002
Coefficient of
Variation (%)
0.37
0.43
2.75
1.70
11-100
-------
Table 31-63. Carbonyl Analytical Precision: 410 Replicate Analyses
for all Duplicate Samples
Pollutant
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
410
0
410
398
79
406
397
404
Average RPD
(%)
2.70
NA
0.76
3.67
7.76
2.53
4.48
3.57
Average
Concentration
Difference (ppbv)
0.002
NA
0.02
0.001
0.001
0.002
0.001
0.001
Coefficient of
Variation (%)
1.91
NA
0.54
2.59
5.49
1.79
3.17
2.52
Due to the focus on QA for the NATTS program, Tables 31-64 through 31-72 present the
analytical precision results from carbonyl replicate analyses of duplicate and collocated samples
at NATTS sites (BTUT, DEMI, GPCO, NBIL, PXSS, S4MO, SEW A, SKFL, and SYFL,
respectively). Shaded rows present results for the NATTS core compounds. The analytical
precision results from the NATTS replicate samples show low- to high-level variability among
the sites, ranging from 0.16 percent for acetaldehyde at GPCO to 37.26 percent for 2,5-
dimethylbenzaldehyde at DEMI. The average CV, 2.53 percent, is well within the program
DQO of 15 percent overall CV per site.
Table 31-64. Carbonyl Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Bountiful, UT (BTUT)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Number of
Observations
24
24
24
24
24
0
24
24
8
Average RPD
(%)
0.36
0.31
4.42
2.00
2.41
NA
0.45
3.03
2.51
Average
Concentration
Difference (ppbv)
0.003
0.01
0.002
0.003
0.002
NA
0.01
0.002
0.001
Coefficient of Variation
(%)
0.25
0.18
3.12
1.41
1.71
NA
0.32
2.14
1.78
31-101
-------
Table 31-64. Carbonyl Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Bountiful, UT (BTUT) (Continued)
Pollutant
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
24
24
24
Average RPD
(%)
2.67
4.57
2.54
Average
Concentration
Difference (ppbv)
0.004
0.002
0.001
Coefficient of Variation
(%)
1.89
3.23
1.79
Table 31-65. Carbonyl Analytical Precision: 120 Replicate Analyses
for Collocated Samples for Dearborn, MI (DEMI)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
120
120
120
120
120
9
120
120
28
120
118
120
Average RPD
(%)
0.41
0.41
3.73
1.17
3.17
52.69
0.77
3.16
3.09
1.70
3.75
3.68
Average
Concentration
Difference (ppbv)
0.01
0.01
0.003
0.004
0.003
0.01
0.03
0.02
0.003
0.01
0.003
0.01
Coefficient of
Variation (%)
0.29
0.30
2.63
0.83
2.24
37.26
0.55
2.24
2.19
1.20
2.65
2.60
Table 31-66. Carbonyl Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Grand Junction, CO (GPCO)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Number of
Observations
24
24
24
24
24
0
24
24
4
Average RPD
(%)
0.22
0.30
1.80
1.58
2.21
NA
0.54
4.89
5.26
Average
Concentration
Difference (ppbv)
0.004
0.01
0.002
0.002
0.001
NA
0.02
0.001
0.001
Coefficient of
Variation (%)
0.16
0.23
1.28
1.12
1.56
NA
0.38
3.46
3.72
31-102
-------
Table 31-66. Carbonyl Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for Grand Junction, CO (GPCO) (Continued)
Pollutant
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
24
24
24
Average RPD
(%)
1.98
3.21
2.97
Average
Concentration
Difference (ppbv)
0.002
0.001
0.001
Coefficient of
Variation (%)
1.40
2.27
2.10
Table 31-67. Carbonyl Analytical Precision: 24 Replicate Analyses
for Collocated Samples for Northbrook, IL (NBIL)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
24
24
24
24
24
0
24
24
0
24
24
24
Average RPD
(%)
1.07
1.51
3.71
2.07
4.33
NA
0.69
2.56
NA
2.72
4.76
3.77
Average
Concentration
Difference (ppbv)
0.002
0.003
0.001
0.001
0.001
NA
0.004
0.001
NA
0.001
0.001
0.001
Coefficient of
Variation (%)
0.75
0.83
2.62
1.46
3.07
NA
0.49
1.81
NA
1.92
3.37
2.67
Table 31-68. Carbonyl Analytical Precision: 12 Replicate Analyses
for Collocated Samples for Phoenix, AZ (PXSS)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Number of
Observations
12
12
12
12
12
0
12
12
4
Average RPD
(%)
1.50
0.65
2.80
3.62
3.43
NA
0.68
2.42
4.00
Average
Concentration
Difference (ppbv)
0.03
0.04
0.003
0.01
0.01
NA
0.03
0.004
0.002
Coefficient of
Variation (%)
1.06
0.37
1.98
2.56
2.42
NA
0.48
1.71
2.83
31-103
-------
Table 31-68. Carbonyl Analytical Precision: 12 Replicate Analyses
for Collocated Samples for Phoenix, AZ (PXSS) (Continued)
Pollutant
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
12
12
12
Average RPD
(%)
3.40
2.30
3.17
Average
Concentration
Difference (ppbv)
0.01
0.002
0.004
Coefficient of
Variation (%)
2.40
1.63
2.24
Table 31-69. Carbonyl Analytical Precision: 24 Replicate Analyses
for Duplicate Samples for St. Louis, MO (S4MO)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
24
24
24
24
24
0
24
24
4
24
24
24
Average RPD
(%)
0.48
0.57
3.88
2.62
2.98
NA
0.62
4.49
6.67
3.05
5.65
3.61
Average
Concentration
Difference (ppbv)
0.01
0.01
0.002
0.003
0.002
NA
0.02
0.001
0.001
0.003
0.002
0.001
Coefficient of
Variation (%)
0.34
0.39
2.75
1.85
2.10
NA
0.44
3.18
4.71
2.16
4.00
2.55
Table 31-70. Carbonyl Analytical Precision: 28 Replicate Analyses
for Collocated Samples for Seattle, WA (SEWA)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Number of
Observations
28
28
28
28
28
0
28
28
4
Average RPD
(%)
0.87
0.42
3.07
2.80
2.88
NA
1.13
3.15
5.56
Average
Concentration
Difference (ppbv)
0.004
0.003
0.001
0.003
0.002
NA
0.01
0.001
0.004
Coefficient of
Variation (%)
0.62
0.17
2.17
1.98
2.04
NA
0.80
2.22
3.93
31-104
-------
Table 31-70. Carbonyl Analytical Precision: 28 Replicate Analyses
for Collocated Samples for Seattle, WA (SEWA) (Continued)
Pollutant
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
28
28
28
Average RPD
(%)
3.70
4.76
3.84
Average
Concentration
Difference (ppbv)
0.003
0.002
0.002
Coefficient of
Variation (%)
2.62
3.36
2.72
Table 31-71. Carbonyl Analytical Precision: 28 Replicate Analyses
for Duplicate Samples for Pinellas Park, FL (SKFL)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
28
28
28
28
28
0
28
28
7
28
27
28
Average RPD
(%)
0.81
0.74
3.42
2.28
1.98
NA
0.73
3.15
45.02
2.09
14.53
3.54
Average
Concentration
Difference (ppbv)
0.01
0.005
0.001
0.002
0.002
NA
0.01
0.001
0.003
0.001
0.002
0.001
Coefficient of
Variation (%)
0.57
0.48
2.42
1.62
1.40
NA
0.51
2.22
31.83
1.48
10.27
2.50
Table 31-72. Carbonyl Analytical Precision: 28 Replicate Analyses
for Duplicate Samples for Plant City, FL (SYFL)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Number of
Observations
28
28
28
28
28
0
28
28
6
Average RPD
(%)
0.66
1.11
3.91
2.13
1.79
NA
0.82
2.08
4.93
Average
Concentration
Difference (ppbv)
0.01
0.01
0.001
0.002
0.003
NA
0.05
0.002
0.004
Coefficient of
Variation (%)
0.47
0.79
2.76
1.51
1.27
NA
0.58
1.47
3.49
31-105
-------
Table 31-72. Carbonyl Analytical Precision: 28 Replicate Analyses
for Duplicate Samples for Plant City, FL (SYFL) (Continued)
Pollutant
Propionaldehyde
Tolualdehydes
Valeraldehyde
Number of
Observations
28
24
28
Average RPD
(%)
2.36
2.96
3.75
Average
Concentration
Difference (ppbv)
0.003
0.001
0.004
Coefficient of
Variation (%)
1.67
2.09
2.65
Table 31-73 presents the average CV per pollutant, per pollutant per site, per site, and the
overall CV for all UATMP and NATTS sites sampling carbonyl compounds. The replicate
results from duplicate and collocated samples show low- to high-level variability among the
sites, ranging from 1.55 percent at ELNJ to 5.03 percent at SKFL. The average CV was 4.96
percent, which is well with in the requested 15 percent overall CV per site.
Table 31-73. Carbonyl Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
0.45
0.46
2.63
1.67
2.06
37.26
0.52
2.64
4.26
1.87
3.19
2.49
4.96
hJ
to
£
s
.a
£
% 3
SJ £
*g
£^
0.61
0.40
3.02
1.86
2.26
NA
0.78
2.79
5.30
1.44
2.45
3.35
2.21
&
a.
et
•Q
•2 p?
^
« B
0.13
0.17
3.13
0.94
3.74
NA
0.74
NA
NA
1.77
4.50
3.20
2.04
H
p
•V
3
^ P
a P
S H
M B
0.25
0.18
3.12
1.41
1.71
NA
0.32
2.14
1.78
1.89
3.23
1.79
1.62
N,
^
o C"
•a y-
1*
u B
0.53
0.43
2.48
1.48
2.77
NA
0.42
2.75
2.83
2.12
2.53
3.01
1.94
H,
^
o3 ^
1§
0.34
0.21
2.65
1.90
1.21
NA
0.44
4.00
4.19
1.50
3.13
3.39
2.09
a
in
£ O
S|
2 H=
uB
0.42
0.30
2.41
2.03
1.60
NA
0.61
1.81
4.72
2.47
3.27
2.29
1.99
HH
S
•V
s^
0 h?
•s s
S w
Q«
0.29
0.30
2.63
0.83
2.24
37.26
0.55
2.24
2.19
1.20
2.65
2.60
4.58
11-106
-------
Table 31-73. Carbonyl Analytical Precision:
for all Replicate Analyses by Site
Coefficient of Variation
(Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
0.45
0.46
2.63
1.67
2.06
37.26
0.52
2.64
4.26
1.87
3.19
2.49
4.96
Elizabeth, NJ
(ELNJ)
0.41
0.48
2.80
0.86
1.69
NA
0.39
2.64
2.28
1.59
3.16
0.74
1.55
-J
u.
fg
|£
0.24
NA
4.16
0.97
2.83
NA
0.90
NA
NA
NA
2.83
3.07
2.14
J
u.
€V / N
5 nJ
o-ta
s <<
H£
0.14
0.68
2.70
2.89
1.01
NA
0.60
2.57
1.35
1.64
2.08
1.77
1.58
Grand Junction,
CO (GPCO)
0.16
0.23
1.28
1.12
1.56
NA
0.38
3.46
3.72
1.40
2.27
2.10
1.61
Gulfport, MS
(GPMS)
0.58
0.64
3.17
2.08
1.68
NA
0.37
2.15
6.44
2.39
2.68
3.01
2.29
Indianapolis, IN
(IDIN)
0.71
0.47
2.38
2.83
2.18
NA
0.55
3.36
1.20
2.26
2.90
3.10
1.99
Gary, IN
(INDEM)
0.30
0.46
2.54
1.19
2.88
NA
0.28
3.02
NA
2.56
4.01
1.35
1.86
Table 31-73. Carbonyl Analytical Precision:
for all Replicate Analyses by Site
Coefficient of Variation
(Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
0.45
0.46
2.63
1.67
2.06
37.26
0.52
2.64
4.26
1.87
3.19
2.49
4.96
Indianapolis,
IN (ININ)
0.73
0.33
3.19
2.08
2.59
NA
0.51
3.22
NA
3.05
3.35
3.47
2.25
Z
H
§§
•a H
3 0
jd
0.64
0.93
2.51
2.01
1.38
NA
0.85
2.26
2.73
1.76
2.71
3.27
1.91
Z
H
a
-------
Table 31-73. Carbonyl Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site (Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
0.45
0.46
2.63
1.67
2.06
37.26
0.52
2.64
4.26
1.87
3.19
2.49
4.96
O
S
•22
'3 o
ai
. Tf
££
0.34
0.39
2.75
1.85
2.10
NA
0.44
3.18
4.71
2.16
4.00
2.55
2.23
Seattle, WA
(SEWA)
0.62
0.17
2.17
1.98
2.04
NA
0.80
2.22
3.93
2.62
3.36
2.72
2.06
Q
!/5
0T
13
*0
Is
£&
0.53
0.37
3.49
1.87
2.00
NA
0.35
2.28
3.72
1.38
2.09
2.87
1.90
&
a.
cS
3$
£ &
0.25
0.41
2.03
2.11
2.03
NA
0.66
2.72
NA
1.23
3.14
2.94
7.75
Pinellas Park,
FL (SKFL)
0.57
0.48
2.42
1.62
1.40
NA
0.51
2.22
31.83
1.48
10.27
2.50
5.03
Schiller Park,
IL (SPIL)
0.89
0.88
1.30
0.53
3.86
NA
0.32
2.37
NA
1.11
4.11
2.03
1.74
hJ
to
>,
-*^
'-J
* >H
£ &
0.47
0.79
2.76
1.51
1.27
NA
0.58
1.47
3.49
1.67
2.09
2.65
1.70
Table 31-73. Carbonyl Analytical Precision:
for all Replicate Analyses by Site
Coefficient of Variation
(Continued)
Pollutant
Acetaldehyde
Acetone
Benzaldehyde
Butyraldehyde
Crotonaldehyde
2,5-Dimethylbenzaldehyde
Formaldehyde
Hexaldehyde
Isovaleraldehyde
Propionaldehyde
Tolualdehydes
Valeraldehyde
Average
Average
0.45
0.46
2.63
1.67
2.06
37.26
0.52
2.64
4.26
1.87
3.19
2.49
4.96
tt
°£
c? O
•lo
3b
0.20
0.42
1.93
1.09
1.87
NA
0.22
4.12
1.20
1.43
3.20
2.57
1.66
tt
go
•3 ^
Sb
0.24
0.33
2.78
1.63
0.96
NA
0.53
2.86
0.90
1.05
4.29
2.01
1.60
tt
°£
Ig
F5F.
0.44
0.63
2.70
1.13
2.70
NA
0.66
2.99
2.57
1.77
3.86
1.37
1.89
!/5
S
al
aj S
O.U
£E
0.28
0.37
2.24
2.08
2.15
NA
0.74
2.55
NA
2.76
1.48
1.83
1.65
Indianapolis, IN
(WPIN)
0.71
0.39
2.39
2.35
2.02
NA
0.41
2.26
3.45
2.61
2.73
2.82
2.01
11-108
-------
31.2.4 Metals Analytical Precision
The analytical precision results for all collocated metals samples are presented in Table
31-74. The average CV values, as well as the average RPD values, show low- to high-level
variability among the sites, with average CVs ranging from 1.14 percent for lead to 33.74 percent
for mercury, with an overall average of 6.26 percent.
Table 31-74. Metal Analytical Precision: 384 Collocated Samples
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
384
384
379
384
384
384
384
383
372
384
384
Average RPD
(%)
1.84
2.86
20.40
3.46
4.52
2.48
1.62
2.51
47.72
4.74
5.37
Average
Concentration
Difference (ng/m3)
0.02
0.03
0.003
0.01
0.11
0.01
0.10
0.51
0.04
0.12
0.03
Coefficient of
Variation (%)
1.30
1.89
14.42
2.45
3.20
1.76
1.14
1.77
33.74
3.36
3.80
Due to the focus on QA for the NATTS program, Tables 31-75 through 31-78 present the
analytical precision results from collocated metals at the NATTS sites (BOMA, BTUT, S4MO,
and SEW A, respectively). Shaded rows present results for the NATTS core compounds.
Table 31-75 presents analytical precision results for the collocated sample analysis for BOMA.
The variability ranged from 0.95 percent (antimony) to 35.80 percent (mercury).
Table 31-75. Metal Analytical Precision: 112 Collocated Samples
at Boston, MA (BOMA)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Number of
Observations
112
112
107
112
112
Average RPD
(%)
1.35
4.11
32.94
1.80
2.71
Average
Concentration
Difference (ng/m3)
0.01
0.02
0.001
0.002
0.06
Coefficient of
Variation (%)
0.95
2.45
23.29
1.28
1.92
11-109
-------
Table 31-75. Metal Analytical Precision: 112 Collocated Samples
at Boston, MA (BOMA) (Continued)
Pollutant
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
112
112
111
110
112
112
Average RPD
(%)
1.75
1.49
2.24
50.63
2.93
6.61
Average
Concentration
Difference (ng/m3)
0.003
0.05
0.09
0.02
0.08
0.01
Coefficient of
Variation (%)
1.23
1.05
1.59
35.80
2.07
4.67
Table 31-76 presents analytical precision results for the collocated sample analysis for
BTUT. The variability ranged from 1.78 percent (manganese) to 31.15 percent (mercury), with
an average variability of 8.09 percent.
Table 31-76. Metal Analytical Precision: 12 Collocated Samples
at Bountiful, UT (BTUT)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
12
12
12
12
12
12
12
12
10
12
12
Average RPD
(%)
2.90
3.37
34.64
4.48
6.37
3.89
3.09
2.52
44.05
6.43
14.09
Average
Concentration
Difference (ng/m3)
0.04
0.06
0.01
0.01
0.11
0.02
0.13
0.52
0.14
0.15
0.08
Coefficient of
Variation (%)
2.05
2.36
24.50
3.17
4.51
2.75
2.19
1.78
31.15
4.54
9.96
Table 31-77 shows metals analytical precision results for the replicate results for
collocated samples at S4MO. The average RPD and CV are within the NATTS requirements for
all but one pollutant (mercury).
31-110
-------
Table 31-77. Metal Analytical Precision: 46 Collocated Samples
at St. Louis, MO (S4MO)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
46
46
46
46
46
46
46
46
38
46
46
Average RPD
(%)
1.04
0.94
15.94
1.11
5.26
1.56
0.61
1.48
43.70
1.14
1.35
Average
Concentration
Difference (ng/m3)
0.02
0.01
0.001
0.01
0.13
0.002
0.07
0.18
0.02
0.01
0.01
Coefficient of
Variation (%)
0.73
0.66
11.27
0.79
3.72
1.10
0.43
1.05
30.90
0.81
0.95
Table 31-78 presents analytical precision results for the collocated sample analysis for
SEWA. The variability ranged from 0.93 percent (lead) to 48.50 percent (mercury), with an
average variability of 7.58 percent.
Table 31-78. Metal Analytical Precision: 4 Collocated Samples
at Seattle, WA (SEWA)
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Number of
Observations
4
4
4
4
4
4
4
4
4
4
4
Average RPD
(%)
2.18
3.80
9.09
8.33
4.84
2.83
1.31
3.82
68.59
10.66
2.88
Average
Concentration
Difference (ng/m3)
0.04
0.05
0.001
0.02
0.17
0.01
0.11
1.05
0.02
0.30
0.01
Coefficient of
Variation (%)
1.54
2.45
6.43
5.89
3.42
2.00
0.93
2.70
48.50
7.54
2.03
31-111
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Table 31-79 presents the average CV per pollutant, per pollutant per site, per site, and the
overall average CV for all UATMP and NATTS sites sampling metals. The results from
collocated samples show low- to high-level variability among sites, ranging from 4.76 percent at
S4MO to 8.09 percent at BTUT, with an overall average of 6.26 percent.
Table 31-79. Metal Analytical Precision: Coefficient of Variation
for all Replicate Analyses by Site
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Lead
Manganese
Mercury
Nickel
Selenium
Average
Average
1.30
1.89
14.42
2.45
3.20
1.76
1.14
1.77
33.74
3.36
3.80
6.26
<5-
a 5
ll
•£ o
M B
0.95
2.45
23.29
1.28
1.92
1.23
1.05
1.59
35.80
2.07
4.67
6.94
H
P
3
s p
ep
3 H
M B
2.05
2.36
24.50
3.17
4.51
2.75
2.19
1.78
31.15
4.54
9.96
8.09
O
•N
'3 o"
° ^
^
~*^ ^o
^^ ^^
0.73
0.66
11.27
0.79
3.72
1.10
0.43
1.05
30.90
0.81
0.95
4.76
<
*^
-------
Table 31-80. Hexavalent Chromium Analytical Precision: Replicate Analyses
for Collocated Samples
Site
BOMA
BTUT
BXNY
CHSC
DEMI
GPCO
HAKY
ININ
MVWI
NBIL
PRRI
PXSS
S4MO
SDGA
SEWA
SYFL
UNVT
WADC
Average
Number of
Observations
16
122
4
4
26
24
14
20
6
16
12
22
20
16
24
12
8
10
21
Average
RPD
(%)
12.43
10.04
10.59
10.54
10.29
10.55
8.09
5.38
22.38
6.30
16.55
5.67
16.19
5.51
6.68
7.95
7.48
12.06
10.26
Average
Concentration
Difference (ng/m3)
0.002
0.002
0.01
0.001
0.002
0.002
0.001
0.001
0.002
0.001
0.001
0.004
0.002
0.001
0.004
0.001
0.001
0.002
0.002
Coefficient of
Variation (%)
8.79
7.10
7.49
7.45
7.27
7.46
5.72
3.81
15.83
4.46
11.70
4.01
11.45
3.89
4.72
5.62
5.29
8.53
7.26
* Over half of the detects were under the detection limit.
31.2.6 SVOC Analytical Precision
The analytical precision results for the replicate analyses of the collocated SVOC samples
is shown in Table 31-81. Both sites evaluated in this section are NATTS sites (RUCA and
SDGA). The average concentration differences observed for SVOC ranged from 0.005 ng/m3
for benzo(a) anthracene to 3.04 ng/m3 for naphthalene. The average CV ranged from
2.67 percent for phenanthrene to 69.05 percent for dibenz (a,h) anthracene, with an overall
average of 21.26 percent, which is outside the 15 percent program DQO.
31-113
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Table 31-81. SVOC Analytical Precision: 98 Collocated Samples
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Benzo (a) pyrene
Benzo (b) fluoranthene
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
Indeno(l,2,3-cd)pyrene
Naphthalene
Perylene
Phenanthrene
Pyrene
Number of
Observations
95
57
51
81
78
75
62
80
68
94
51
11
96
96
53
98
11
98
94
Average RPD
(%)
5.64
68.28
25.03
15.72
43.15
45.05
53.47
12.24
43.22
5.10
43.65
97.66
5.11
5.54
24.41
4.28
63.72
3.78
6.12
Average
Concentration
Difference (ng/m3)
0.13
0.08
0.13
0.005
0.08
0.02
0.02
0.01
0.01
0.01
0.03
0.03
0.07
0.22
0.02
3.04
0.02
0.28
0.05
Coefficient of
Variation (%)
3.99
48.28
17.70
11.11
30.51
31.85
37.81
8.66
30.56
3.61
30.86
69.05
3.61
3.92
17.26
3.03
45.05
2.67
4.33
Table 31-82 shows the analytical precision results for the SVOC analysis for collocated
samples for RUCA. The average CV ranged from 4.38 percent for phenanthrene to 82.88
percent for perylene, with an overall average of 23.06 percent, which is outside the 15 percent
program DQO.
Table 31-82. SVOC Analytical Precision: 90 Collocated Samples
at Rubidoux, CA (RUCA)
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Benzo (a) pyrene
Benzo (b) fluoranthene
Number of
Observations
87
51
47
73
71
68
Average RPD
(%)
8.45
36.04
47.99
24.48
33.27
34.94
Average
Concentration
Difference (ng/m3)
0.21
0.07
0.26
0.01
0.05
0.02
Coefficient of
Variation (%)
5.98
25.48
33.93
17.31
23.52
24.71
31-114
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Table 31-82. SVOC Analytical Precision: 90 Collocated Samples
at Rubidoux, CA (RUCA) (Continued)
Pollutant
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
lndeno(l,2,3-cd)pyrene
Naphthalene
Perylene
Phenanthrene
Pyrene
Number of
Observations
57
72
61
86
45
8
88
88
49
90
7
90
86
Average RPD
(%)
39.13
17.17
34.79
6.54
46.46
94.19
8.12
8.23
41.75
6.47
117.21
6.20
8.12
Average
Concentration
Difference (ng/m3)
0.03
0.01
0.02
0.01
0.02
0.04
0.13
0.37
0.01
4.24
0.03
0.51
0.08
Coefficient of
Variation (%)
27.67
12.14
24.60
4.62
32.85
66.60
5.74
5.82
29.52
4.57
82.88
4.38
5.74
Table 31-83 shows the analytical precision results for the semivolatiles analysis for
collocated samples for SDGA. The average CV ranged from 0.96 percent for phenanthrene to
71.50 percent for dibenz (a,h) anthracene, with an overall average of 19.46 percent, which is
outside the 15 percent program DQO.
Table 31-83. SVOC Analytical Precision: 8 Collocated Samples
at Decatur, GA (SDGA)
Pollutant
Acenaphthene
Acenaphthylene
Anthracene
Benzo (a) anthracene
Benzo (a) pyrene
Benzo (b) fluoranthene
Benzo (e) pyrene
Benzo (g,h,i) perylene
Benzo (k) fluoranthene
Chrysene
Coronene
Number of
Observations
8
6
4
8
7
7
5
8
7
8
6
Average RPD
(%)
2.83
100.52
2.07
6.95
53.02
55.15
67.81
7.31
51.65
3.66
40.83
Average
Concentration
Difference (ng/m3)
0.05
0.08
0.01
0.002
0.10
0.02
0.01
0.01
0.01
0.003
0.03
Coefficient of
Variation (%)
2.00
71.08
1.47
4.92
37.49
39.00
47.95
5.17
36.52
2.59
28.87
31-115
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Table 31-83. SVOC Analytical Precision: 8 Collocated Samples
at Decatur, GA (SDGA) (Continued)
Pollutant
Dibenz (a,h) anthracene
Fluoranthene
Fluorene
lndeno(l,2,3-cd)pyrene
Naphthalene
Perylene
Phenanthrene
Pyrene
Number of
Observations
o
J
8
8
4
8
4
8
8
Average RPD
(%)
101.12
2.09
2.85
7.07
2.10
10.22
1.36
4.13
Average
Concentration
Difference (ng/m3)
0.02
0.02
0.06
0.02
1.85
0.003
0.05
0.02
Coefficient of
Variation (%)
71.50
1.48
2.01
5.00
1.48
7.23
0.96
2.92
31.3 Accuracy
Laboratories typically evaluate their accuracy (or bias) by analyzing external audit
samples and comparing the measured concentrations obtained to the known concentrations of
those audit samples. Accuracy, or bias, indicates the extent to which experimental measurements
represent their corresponding "true" or "actual" values.
Laboratories participating in the NATTS program are provided with proficiency test (PT)
audit samples on a quarterly basis for VOC, carbonyls, and metals, which are used to
quantitatively measure analytical accuracy. Tables 31-84 through 31-86 present ERG's results
from the 2007 NATTS PT audit samples for carbonyls, metals, and VOC, respectively. The
acceptable percent difference from the true values is ± 25 percent, and the values exceeding this
criteria are bolded in the tables. While there are a few values outside the program DQOs, there
are no compounds that are consistently over for multiple audits. Shaded rows present results for
NATTS core compounds.
Table 31-84. Carbonyl NATTS PT Audit Samples - Percent Difference from True Value
Pollutant
Acetaldehyde
Formaldehyde
April, 2007
-6.4
-12.0
November, 2007
2.7
5.6
31-116
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Table 31-85. Metals NATTS PT Audit Samples - Percent Difference from True Value
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Lead
Manganese
Mercury
Nickel
April, 2007
-23.2
16.0
16.3
9.8
6.3
0.7
10.2
7.6
July, 2007
-17.6
13.0
17.2
6.2
0.0
-24.0
Not included
-11.2
October, 2007
-24.1
14.3
34.0
15.2
4.4
-7.3
Not included
-3.9
December, 2007
-33.0
2.8
7.9
-10.2
-16.8
-24.4
Not included
-26.6
Table 31-86. VOC NATTS PT Audit Samples - Percent Difference from True Value
Pollutant
Acrolein
Benzene
1,3 -Butadiene
Carbon Tetrachloride
Chloroform
1 ,2-Dibromoethane
1 ,2-Dichloroethane
Dichloromethane
1 ,2-Dichloropropane
cis- 1 ,3 -Dichloropropene
trans- 1 , 3 -Dichloropropene
1 , 1 ,2,2-Tetrachloroethane
retrachloroethylene
rrichloroethylene
Vinyl Chloride
April, 2007
-34.3
-3.9
-8.0
17.9
5.3
-2.5
12.8
0.8
-3.9
-2.9
-6.2
-7.9
-9.2
-0.8
5.8
July, 2007
-16.0
-1.0
-3.0
-1.7
2
7.8
0.0
5.3
-1.0
8.0
9.8
0.9
3.1
4.3
1.1
September, 2007
5.8
-12.5
14.2
11.9
20.0
0.9
8.5
10.4
-5.0
-2.7
-1.4
-10.3
-5.1
9.2
-3.8
December, 2007
14.6
Not included
6.9
13.7
Not included
9.9
9.3
15.0
Not included
Not included
Not included
-1.0
Not included
9.3
Not included
The accuracy of the 2007 monitoring data can also be assessed qualitatively by reviewing
the accuracy of the monitoring methods and how they were implemented:
• The sampling and analytical methods used in the 2007 monitoring effort have
been approved by EPA for accurately measuring ambient levels of various
compounds—an approval that is based on many years of research into the
development of ambient air monitoring methodologies.
• When collecting and analyzing ambient air samples, all field sampling staff and
laboratory analysts strictly followed quality control and quality assurance
guidelines detailed in the respective monitoring methods. This strict adherence to
31-117
-------
the well-documented sampling and analytical methods suggests, though certainly
does not prove, that the 2007 monitoring data accurately represent ambient air
quality.
31-118
-------
32.0 Summary of Results and Recommendations
The following discussion summarizes the results of the data analyses contained in this
report and presents recommendations applicable to future air monitoring efforts. As
demonstrated by the data analyses discussed throughout this report, NATTS and UATMP
monitoring data offer a wealth of information for assessing air quality by evaluating trends,
patterns, correlations, and the potential for health risk and should ultimately assist a wide range
of audiences understand the complex nature of air pollution.
32.1 Summary of Results
Analyses of the 2007 monitoring data identified the following notable results,
observations, trends, and patterns in the program-level and state-specific air pollution data:
32.1.1 National-level Summary
$ Ambient air concentration data sets generally met data quality objectives for
completeness. Completeness, or the number of valid samples collected compared to
the number expected from a l-in-6 or l-in-12 day sampling schedule, measures the
reliability of the sampling and analytical equipment as well as the efficiency of the
program. Typically, a completeness of 85-100 percent is desired for a complete data
set. Only one out of 100 data sets failed to comply with the data quality objective of
85 percent completeness. Thirty-five data sets achieved 100 percent completeness.
$ Nearly half of all participating monitoring sites are NA TTS sites. Twenty-three of the
50 sites are EPA-designated NATTS sites (BOMA, BTUT, BXNY, CAMS 35,
CAMS 85, CELA, CHSC, DEMI, GPCO, HAKY, MVWI, NBIL, PRRI, PXSS,
ROCH, RUCA, S4MO, SDGA, SEW A, SKFL, SYFL, UNVT, and WADC).
$ Total number of samples collected and analyzed. Over 6,000 samples were collected
and 190,745 valid measurements of air toxics were obtained.
$ Ambient air concentrations of urban air toxics. Nearly 81 percent of the measured
concentrations were less than 1 |ig/m3. Less than 3 percent of the concentrations
were greater than 5 |ig/m3.
$ Detects. The detection of a given pollutant is subject to the analytical methods used
and the limitations of the instruments. Simply stated, a method detection limit is the
lowest concentration of a substance that can be measured and reported with 99
percent confidence that the pollutant concentration is greater than zero. For 2007,
only two pollutants, 2-ethyl-l-butene and propyne, were not detected at any of the
participating monitoring sites.
32-1
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Program-level Pollutants of Interest. The pollutants of interest at the program level,
based on the number of exceedances, or "failures," of the preliminary risk screening
values, included: acetaldehyde, acrolein, acrylonitrile, arsenic, benzene, 1,3-
butadiene, carbon tetrachloride, /?-dichlorobenzene, formaldehyde, manganese, and
tetrachloroethylene. The pollutants of interest varied among the individual sites.
Pearson Correlations. Pearson Correlations were computed between each pollutant
of interest and various meteorological parameters. Generally, the meteorological
parameters had weak correlations with the program-level pollutants of interest across
all sites. The Pearson Correlations tended to be stronger at the individual sites.
BTEXProfiles. The concentration ratios for the BTEX compounds measured at most
of the monitoring sites bear some resemblance to the ratios reported in the roadside
study (Conner, et al., 1995). The BTEX ratios for the BAPR and GPCO monitoring
sites appear to be the most similar to the roadside study profile, indicating the
influence of motor vehicle emissions.
Risk Screening using ATSDRMRLs. Daily measurements (measured at SFSD and
INDEM), seasonal averages (calculated for INDEM), and one annual average
(calculated for INDEM) of formaldehyde exceeded the ATSDR acute, intermediate,
and chronic MRLs, respectively. All of the site-specific seasonal averages of acrolein
exceeded the ATSDR intermediate MRL.
Surrogate Cancer Risk Approximations. The surrogate cancer risk approximation
calculated for SPAZ for acrylonitrile (52 in-a-million) was the highest of all annual
average-based cancer risk approximations. By comparison, NATA-modeled cancer
risk was highest for arsenic at ININ (208 in-a-million), dichloromethane at BAPR (71
in-a-million), and benzene at TOOK (30 in-a-million).
Surrogate Noncancer Risk Approximations. Four sites exhibited noncancer risk
approximations for acrolein that were greater than 50 (PXSS, CNEP, SPAZ, and
TUOK). In total, 27 sites had noncancer risk approximations for acrolein that were
greater than 1.0. Noncancer risk (HQ) based on NATA was highest for acrolein for
ELNJ (35.46). In addition, a noncancer risk approximation greater than 1.0 was also
calculated for formaldehyde at INDEM.
Emissions and Toxicity Weighted Emissions. The pollutant (with a cancer URE) that
tended to have the highest county-level emissions for most participating counties was
benzene. This pollutant also tended to have the highest toxicity-weighted emissions.
Acrolein tended to have the highest toxicity-weighted emissions of pollutants with
noncancer RfCs, although it was not emitted in high enough quantities to rank in the
top 10 emissions for any participating county. Toluene was often the highest emitted
pollutant with a noncancer risk factor, although it rarely had top 10 toxicity-weighted
emissions.
32-2
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32.1.2 State-level Summary
Arizona.
• The Arizona monitoring sites are located in Phoenix. PXSS is a NATTS site; SPAZ
is a UATMP site.
• Back trajectories originated from a variety of directions at PXSS. The back
trajectories primarily originated from the southwest and north at SPAZ. The air shed
domains were somewhat smaller in size compared to other monitoring sites, as the
farthest away a back trajectory originated was less than 400 miles.
• The wind rose shows that easterly winds were prevalent near PXSS and calm winds
were prevalent near SPAZ.
• PXSS sampled for VOC, carbonyls, SVOC, metals (PMio), and hexavalent
chromium. SPAZ sampled for VOC only.
• The pollutants of interest common to both sites were acrolein, benzene, 1,3-
butadiene, carbon tetrachloride, />-dichlorobenzene, and tetrachloroethylene.
• Of the pollutants of interest for PXSS, formaldehyde had the highest daily average
concentration. In addition, PXSS had the highest daily average concentration of
acrolein, benzene, manganese (PMio), and tetrachloroethylene among all NATTS and
UATMP sites sampling these compounds.
• Of the pollutants of interest for SPAZ, benzene had the highest daily average
concentration. In addition, SPAZ had the highest daily average concentration of
acrylonitrile among all NATTS and UATMP sites sampling this compound.
• Correlations between the pollutants of interest for PXSS and SPAZ and the
meteorological parameters were mostly weak. Strong negative correlations were
calculated between 1,3-butadiene and maximum and average temperatures. Strong
negative correlations were also calculated for 1,3-butadiene and benzene and
maximum and average temperatures.
• The seasonal averages of acrolein that could be calculated for PXSS and SPAZ
exceeded the ATSDR intermediate risk factor.
• According to NATA, benzene had the highest cancer risk estimate for both PXSS and
SPAZ while acrolein was the only pollutant with a noncancer HQ greater than 1.0.
Cancer and noncancer surrogate risk approximations could not be calculated for these
compounds due to the short sampling duration.
• Benzene was the highest emitted pollutant with a cancer risk factor in Maricopa
County, Arizona, while toluene was the highest emitted pollutant with a noncancer
32-3
-------
risk factor. Benzene also had the highest cancer toxicity-weighted emissions, while
acrolein had the highest noncancer toxicity-weighted emissions in Maricopa County.
California.
• The two California monitoring sites are located in Los Angeles (CELA) and
Rubidoux (RUCA) and are both NATTS sites.
• Back trajectories primarily originated from the northwest and northeast at CELA and
RUCA. The air shed domains were somewhat smaller in size compared to other
monitoring sites, as the farthest away a back trajectory originated was 500 miles.
• The wind roses show that westerly winds were prevalent near RUCA and calm winds
were prevalent near CELA.
• CELA and RUCA sampled for SVOC only.
• Naphthalene was the only SVOC to fail screens at the California sites and is therefore
the only pollutant of interest for these sites.
• The daily average concentrations of naphthalene were similar for both sites.
Compared to other program sites sampling SVOC, CELA and RUCA had the third
and fourth highest daily average concentrations of naphthalene, respectively.
• The Pearson correlations for naphthalene were generally weak at the California sites.
• None of the SVOC daily measurements or concentration averages for the California
sites exceeded any of the MRL risk values.
• The NATA-modeled concentration of naphthalene was slightly higher for CELA than
RUCA, which translated into slightly higher cancer and noncancer risks. Because
sampling did not begin until the spring, annual averages (and therefore cancer and
noncancer surrogate risk approximations) could not be calculated for naphthalene.
• Formaldehyde was the highest emitted pollutant with a cancer risk factor in both Los
Angeles and Riverside Counties, while benzene had the highest cancer toxicity-
weighted emissions.
• Toluene was the highest emitted pollutant with a noncancer risk factor in Riverside
County, while 1,1,1-trichloroethane was the highest emitted pollutant in Los Angeles
County. Acrolein had the highest noncancer toxicity-weighted emissions in both
counties.
Colorado.
• The NATTS site in Colorado is located in Grand Junction.
32-4
-------
• Back trajectories originated from a variety of directions at GPCO, although less
frequently from the east. The 24-hour air shed domain GPCO was somewhat smaller
in size than other monitoring sites, as the furthest away a trajectory originated was
nearly 500 miles away.
• The wind rose shows that easterly, east-southeasterly, and southeasterly winds were
prevalent near GPCO.
• GPCO sampled for VOC, carbonyls, and hexavalent chromium.
• The following pollutants were identified as pollutants of interest for GPCO:
acetaldehyde, acrolein, benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde,
and tetrachloroethylene.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for GPCO, followed by acetaldehyde and benzene. Benzene and 1,3-
butadiene concentrations were highest in autumn and winter.
• Correlations between 1,3-butadiene and the temperature parameters support the trends
shown by the seasonal averages. Strong positive correlations were calculated forl,3-
butadiene and benzene and sea level pressure. Additionally, all of the correlations
with wind speed were negative.
• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor.
• Benzene had the highest NATA-modeled cancer risk for GPCO, and the second
highest cancer risk approximation. 1,2-Dibromoethane had the highest cancer risk
approximation, although the annual average includes only one valid measured
detection.
• Acrolein had the highest NATA-modeled noncancer risk and noncancer risk
approximation for GPCO, although the noncancer risk approximation was an order of
magnitude higher.
• Benzene was the highest emitted pollutant with a cancer risk factor in Mesa County,
Colorado, while toluene was the highest emitted pollutant with a noncancer risk
factor. Benzene also had the highest cancer toxicity-weighted emissions, while
acrolein had the highest noncancer toxicity-weighted emissions in Mesa County.
Washington D. C.
• The Washington D.C. monitoring site is a NATTS site.
• Back trajectories originated from a variety of directions at WADC, although less
frequently from the south. The 24-hour air shed domain for WADC was similar in
32-5
-------
size to other monitoring sites, with the longest trajectory originating nearly 700 miles
away.
• The wind rose shows that southerly winds were prevalent near WADC.
• WADC sampled for hexavalent chromium only. Although hexavalent chromium did
not fail any screens, analyses were still conducted on samples for this pollutant.
• Seasonal averages of hexavalent chromium did not vary significantly from season to
season. Compared to other program sites sampling hexavalent chromium, WADC
had the second lowest daily average concentration.
• Correlations between concentrations of hexavalent chromium and selected
meteorological parameters were weak.
• None of the daily measurements or concentration averages of hexavalent chromium
exceeded any of the MRL risk values.
• Cancer and noncancer risks for hexavalent chromium were low according to NATA.
The same is also true of the cancer and noncancer surrogate risk approximations.
• Benzene was the highest emitted pollutant with a cancer risk factor in the District of
Columbia, while toluene was the highest emitted pollutant with a noncancer risk
factor. Benzene also had the highest cancer toxicity-weighted emissions, while
acrolein had the highest noncancer toxicity-weighted emissions in the District.
Florida.
• Two of the Florida monitoring sites are located in the Tampa area (GAFL and SYFL);
two are located in the St. Petersburg area (AZFL and SKFL); one is located near
Orlando (ORFL); and one is located near Ft. Lauderdale (FLFL). Two monitoring
sites in the Tampa/St. Petersburg area are NATTS sites (SKFL and SYFL).
• Back trajectories originated from a variety of directions near the monitoring sites,
although the majority originated from the east at each site.
• Although the wind roses were different for each site, easterly and northeasterly winds
were prevalent among the sites.
• All six Florida monitoring sites sampled for carbonyl compounds. SYFL also
sampled hexavalent chromium.
• Acetaldehyde and formaldehyde were the only pollutants to fail screens for each of
the Florida sites.
32-6
-------
• SYFL had the highest daily averages of acetaldehyde and formaldehyde among the
Florida sites.
• Sampling has been conducted at AZFL, GAFL, and ORFL for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
rolling average concentration of formaldehyde increased slightly for the 2004-2006
and 2005-2007 periods; the maximum formaldehyde concentration measured in 2005
at GAFL appears to be impacting the statistical values for periods incorporating that
year's data; while the range of concentrations measured at ORFL increased, the
average rolling formaldehyde concentration decreased.
• Negative Pearson correlations were calculated between acetaldehyde and the
temperature and moisture variables. Both acetaldehyde and formaldehyde exhibited
negative correlations with the wind speed. In addition, formaldehyde exhibited
strong positive correlations with temperature at AZFL.
• None of the daily measurements or concentration averages for the Florida sites
exceeded any of the MRL risk values.
• The cancer risk for acetaldehyde from NATA ranged from 2.66 in-a-million (AZFL)
to 4.37 in-a-million (ORFL), while the cancer surrogate risk approximations for
acetaldehyde ranged from 2.85 in-a-million (AZFL) to 5.46 in-a-million (SYFL).
• Cancer risk from formaldehyde was 0.01 in-a-million for all six Florida sites,
according to NATA. The surrogate cancer risk approximations from formaldehyde
were 0.02 in-a-million or less for all six Florida sites.
• The noncancer risk from NATA and the noncancer surrogate risk approximations for
both acetaldehyde and formaldehyde were less than 1.0 for the Florida sites.
• Benzene was the highest emitted pollutant with a cancer risk factor in all four Florida
counties. Benzene also had the highest cancer toxicity-weighted emissions for three
of the four counties (naphthalene had the highest cancer toxicity-weighted emissions
in Broward County).
• Toluene was the highest emitted pollutant with a noncancer risk factor in three of the
four counties (xylenes were highest in Broward County). Acrolein had the highest
noncancer toxicity-weighted emissions for all four counties.
Georgia.
• The SDGA monitoring site located south of Atlanta is a NATTS site.
• Back trajectories originated from a variety of directions at SDGA. The 24-hour air
shed domain for SDGA was somewhat larger in size compared to other monitoring
sites, as the longest trajectory originated nearly 900 miles away.
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• The wind rose shows that easterly and northwesterly winds were prevalent near
SDGA.
• SDGA sampled for SVOC and hexavalent chromium. Naphthalene was the only
pollutant to fail screens for SDGA.
• Because SDGA did not begin sampling SVOC until April, seasonal averages of
naphthalene could only be calculated for summer and autumn.
• Naphthalene exhibited strong negative correlations with wind speed.
• None of the daily measurements or concentration averages of naphthalene exceeded
any of the MRL risk values.
• Because annual averages could not be calculated, cancer and noncancer surrogate risk
approximations for naphthalene were not calculated
• Benzene was the highest emitted pollutant with a cancer risk factor in De Kalb
County, while methyl isobutyl ketone was the highest emitted pollutant with a
noncancer risk factor. Benzene also had the highest cancer toxicity-weighted
emissions, while acrolein had the highest noncancer toxicity-weighted emissions in
De Kalb County.
Illinois.
• The Illinois monitoring sites are located near Chicago. NBIL is a NATTS site; SPIL
is a UATMP site.
• Back trajectories originated from a variety of directions at the sites, although back
trajectories primarily originated from the southwest and northwest. The air shed
domains were larger in size compared to other monitoring sites, as the farthest away a
back trajectory originated was approximately 1000 miles.
• The wind roses show that winds from a variety of directions were observed near the
monitoring sites, although southeasterly winds were observed the least.
• NBIL sampled for VOC, carbonyls, SNMOC, metals (PMi0), and hexavalent
chromium, while SPIL sampled for VOC and carbonyls only.
• The pollutants of interest common to both sites were acetaldehyde, acrolein, benzene,
1,3-butadiene, carbon tetrachloride, formaldehyde, /?-dichlorobenzene, and
tetrachl oroethy 1 ene.
• Of the pollutants of interest for NBIL, benzene had the highest daily average
concentration. Of the pollutants of interest for SPIL, formaldehyde had the highest
daily average concentration.
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• VOC sampling has been conducted at NBIL and SPIL for at least five consecutive
years; thus three-year rolling metrics were calculated. In brief, the rolling average
concentration of 1,3-butadiene appears to have increased slightly since the onset of
sampling at both sites, although this is likely attributable to the increased detection
rate due to lowered detection limits; the rolling average concentrations of benzene
have decreased at both sites.
• Correlations between the pollutants of interest for NBIL and SPIL and the
meteorological parameters were mostly weak. However, the majority of the
correlations with the temperature and moisture parameters were positive and most of
the correlations with scalar wind speed were negative.
• The seasonal averages of acrolein exceeded the ATSDR intermediate MRL risk
factor.
• According to NATA, benzene had the highest cancer risk estimates for both NBIL
and SPIL and acrolein was the only pollutant with a noncancer HQ greater than 1.0.
Carbon tetrachloride had the highest cancer surrogate risk approximation for both
sites, while acrolein had the highest noncancer surrogate risk approximation for both
sites.
• Benzene was the highest emitted pollutant with a cancer risk factor in Cook County,
Illinois, while toluene was the highest emitted pollutant with a noncancer risk factor.
Benzene also had the highest cancer toxicity-weighted emissions, while acrolein had
the highest noncancer toxicity-weighted emissions in Cook County.
Indiana.
• Three Indiana monitoring sites are located in Indianapolis (IDIN, ININ, WPIN), and
the fourth is located near Chicago (INDEM). All four are UATMP sites.
• Back trajectories originated from a variety of directions at the Indiana sites, although
the predominant direction of trajectory origin was from the southwest and northwest.
The air shed domain for INDEM was larger in size compared to the other Indiana
monitoring sites.
• The wind roses show that winds from a variety of directions were observed near the
Indianapolis sites, although winds with a westerly component were observed more
frequently. Although winds from a variety of directions were also observed near
INDEM, westerly, south-southwesterly, and southerly winds were observed most
frequently. Calm winds were observed more often near INDEM than the Indianapolis
monitoring sites.
• ININ sampled for carbonyls, metals (PMio), and hexavalent chromium; IDIN sampled
for carbonyls and metals (PMio); WPIN and INDEM sampled for carbonyls only.
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• The pollutants of interest common to all four monitoring sites were acetaldehyde and
formaldehyde, due in part to the differences in pollutants sampled. Manganese and
arsenic were also pollutants of interest for ININ and IDIN, which sampled pollutants
other than carbonyl compounds.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for all four sites. The concentrations of formaldehyde for INDEM were
the highest among all NATTS & UATMP monitoring sites.
• Concentrations of the pollutants of interest, especially the carbonyls, tended to
increase with increasing dry bulb, dew point, and wet bulb temperatures at the
Indianapolis sites. In addition, concentrations of the pollutants of interest for all four
sites, especially the carbonyls, tended to increase with decreasing relative humidity
and wind speed.
• Concentrations of formaldehyde exceeded the ATSDR acute, intermediate, and
chronic MRL risk factors for INDEM.
• According to NATA, arsenic had the highest cancer risk estimate for IDIN and ININ.
The cancer risk estimate for arsenic for ININ was 208 in-a-million, which is the
highest cancer risk estimate among all census tracts with UATMP or NATTS sites
from NATA for any given air toxic pollutant. The cancer risk for IDIN was much
lower. Arsenic was also the only pollutant with a noncancer HQ greater than 1.0 at
any of the sites (ININ), according to NATA.
• According to NATA, acetaldehyde had the highest cancer risk estimates for WPIN
and INDEM.
• Benzene was the highest emitted pollutant with a cancer risk factor in Marion and
Lake Counties, while coke oven emissions had the highest cancer toxicity-weighted
emissions for both counties.
• Toluene was the highest emitted pollutant with a noncancer risk factor in Marion
County, while acrolein had the highest noncancer toxicity-weighted emissions. In
Lake County, hydrochloric acid was the highest emitted pollutant with a noncancer
risk factor, while manganese had the highest noncancer toxicity-weighted emissions.
Kentucky.
• The Hazard, Kentucky monitoring site is a NATTS site.
• Back trajectories originated primarily from the south and southwest. The 24-hour air
shed domain for HAKY was similar in size to other monitoring sites, with the longest
trajectory originating more than 700 miles away.
• The wind rose shows that calm winds were prevalent near HAKY.
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• HAKY sampled for hexavalent chromium only. One measurement of hexavalent
chromium failed screens for HAKY.
• Seasonal averages of hexavalent chromium did not vary significantly from season to
season. Compared to other program sites sampling hexavalent chromium, HAKY
had the sixth lowest daily average concentration.
• Correlations between concentrations of hexavalent chromium and selected
meteorological parameters were weak.
• None of the daily measurements or concentration averages of hexavalent chromium
exceeded any of the MRL risk values.
• Cancer and noncancer risks for hexavalent chromium were low according to NATA.
The same was also true of the cancer and noncancer surrogate risk approximations.
• Benzene was the highest emitted pollutant with a cancer risk factor in Perry County,
while toluene was the highest emitted pollutant with a noncancer risk factor. Benzene
also had the highest cancer toxicity-weighted emissions, while acrolein had the
highest noncancer toxicity-weighted emissions.
Massachusetts.
• The Massachusetts monitoring site is a NATTS site in Dudley Square, Boston.
• Back trajectories originated from a variety of directions at BOMA, although less
frequently from the southeast. The 24-hour air shed domain for BOMA was similar
in size to other monitoring sites, with the longest trajectory originating nearly 800
miles away.
• The wind rose shows that southwesterly and westerly winds were prevalent near
BOMA.
• BOMA sampled for metals (PMio) and hexavalent chromium. Arsenic, nickel, and
manganese were identified as the pollutants of interest for BOMA.
• Of the pollutants of interest, manganese had the highest daily average concentration.
Seasonal averages of the pollutants of interest did not vary significantly from season
to season.
• Metals sampling has been conducted at BOMA for at least five consecutive years;
thus three-year rolling metrics were calculated for arsenic. In brief, the rolling
average concentration of arsenic appeared to have a decreasing trend over the time
periods shown.
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• Correlations between concentrations of the pollutants of interest and selected
meteorological parameters were weak.
• None of the daily measurements or concentration averages of the pollutants of interest
exceeded any of the MRL risk values.
• Cancer risk approximations based on the annual averages for arsenic and nickel were
an order of magnitude higher than the NATA cancer risk estimates. Similar to the
NATA results, noncancer risk approximations based on the annual averages for the
pollutants of interest were low.
• Benzene was the highest emitted pollutant with a cancer risk factor in Suffolk
County, while toluene was the highest emitted pollutant with a noncancer risk factor.
Benzene also had the highest cancer toxicity-weighted emissions, while acrolein had
the highest noncancer toxicity-weighted emissions.
Michigan.
• DEMI is a NATTS site located in Dearborn, Michigan near Detroit. ITCMI is a
UATMP site located in Sault St. Marie, Michigan and is operated by the Intertribal
Council of Michigan.
• Back trajectories originated from a variety of directions at the Michigan sites,
although the predominant direction of trajectory origin was from the south and
northwest for DEMI and northwest and southwest for ITCMI. The air shed domain
for ITCMI was larger in size compared to DEMI.
• The wind rose for DEMI shows that winds from a variety of directions were observed
near the monitoring site, although southeasterly winds were observed the least.
Although winds from a variety of directions were also observed near ITCMI, easterly
and northwesterly winds were observed most frequently.
• DEMI sampled for VOC, carbonyls, and hexavalent chromium, while ITCMI
sampled for SVOC only. As such, there could be no similarity in the sites' pollutants
of interest.
• The pollutants of interest for DEMI were acetaldehyde, acrolein, benzene, 1,3-
butadiene, carbon tetrachloride, formaldehyde, />-dichlorobenzene, and
tetrachloroethylene. Naphthalene was the only pollutant to fail screens for ITCMI.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for DEMI. This was also the second highest daily average
concentration of formaldehyde among sites sampling carbonyls.
• Acetaldehyde and formaldehyde concentrations tended to be highest during the
warmer seasons at DEMI.
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• Seasonal averages of naphthalene did not vary significantly from season to season at
ITCMI. Compared to other program sites sampling SVOC, ITCMI had the lowest
daily average concentration of naphthalene.
• Carbonyl and VOC sampling has been conducted at DEMI for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
rolling average concentration of benzene has decreased; the rolling average
concentration of 1,3-butadiene appears unchanged since the onset of sampling,
although the effects of the increased detection rate can be seen in the other statistical
metrics; the similarity in the median and rolling average concentrations of
formaldehyde indicate little variability in the central tendency.
• The majority of the correlations with the temperature and moisture parameters were
positive and most of the correlations with scalar wind speed were negative for both
sites. At DEMI, formaldehyde and acetaldehyde exhibited strong positive
correlations with the temperature and moisture parameters (except relative humidity).
• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor for
DEMI.
• According to NATA, benzene had the highest cancer risk estimate for DEMI and
acrolein was the only pollutant with a noncancer HQ greater than 1.0. Acetaldehyde
had the highest cancer risk approximation for DEMI, while acrolein had the highest
noncancer risk approximation.
• For ITCMI, the surrogate cancer risk approximation for naphthalene was greater than
1-in-a-million, while the cancer risk estimate from NATA was slightly less. The
noncancer risk estimate from NATA and the surrogate noncancer risk approximation
for naphthalene were both low.
• Benzene was the highest emitted pollutant with a cancer risk factor in Wayne and
Chippewa Counties. Benzene also had the highest toxicity-weighted emissions in
Chippewa County, while coke oven emissions had the highest cancer toxicity-
weighted emissions for Wayne County.
• Toluene was the highest emitted pollutant with a noncancer risk factor in both
counties, while acrolein had the highest noncancer toxicity-weighted emissions.
Mississippi.
• The two UATMP sites in Mississippi are located in Gulfport (GPMS) and Tupelo
(TUMS).
• Back trajectories originated from a variety of directions at the Mississippi sites. The
predominant direction of trajectory origin for GPMS was from offshore, particularly
from the southeast, while the predominant direction of trajectory origin for TUMS
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was from the southeast, south, and southwest. The 24-hour air shed domain for
GPMS was smaller than the air shed domain for TUMS.
• The wind rose for GPMS shows that calm winds prevailed near this site, although
northerly and southeasterly winds were also observed frequently. Calm winds also
prevailed near TUMS, with frequent southerly and northerly winds as well.
• GPMS and TUMS both sampled for VOC and carbonyls. GPMS also sampled
SNMOC.
• The pollutants of interest common to both sites were acetaldehyde, acrolein, benzene,
1,3-butadiene, carbon tetrachloride, formaldehyde.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for both sites.
• While concentrations of most of the pollutants of interest for GPMS and TUMS did
not vary significantly from season to season, formaldehyde was highest during the
summer.
• Carbonyl and VOC sampling has been conducted at GPMS for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
average rolling concentration of benzene fluctuated across the sampling periods; the
rolling average concentration of 1,3-butadiene appeared to change little over the last
several three-year periods, although the effects of the increased detection rate can be
seen in the other statistical metrics; a slight decrease was evident in the average
formaldehyde concentration from 2001-2003 to 2002-2004, then a slight increase for
2003-2005 and 2004-2006, and little change for 2005-2007. Note that the data
included for 2005 was part of the post-Hurricane Katrina monitoring effort.
• Carbonyl and VOC sampling has been conducted at TUMS for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
rolling average and median concentrations of benzene have been decreasing since the
onset of sampling, although the range of concentrations measured has increased; the
median and average rolling concentrations of 1,3-butadiene became more similar over
the last three periods, indicating a decreasing variability in the central tendency; the
average concentration of formaldehyde decreased from the 2001-2003 time frame
until the 2004-2006 time frame, while an increase is shown for 2005-2007. Note that
a portion of the data included for 2005 was part of the post-Hurricane Katrina
monitoring effort.
• At GPMS, formaldehyde exhibited strong positive correlations with the temperature
parameters; 1,3-butadiene exhibited strong negative correlations with the temperature
and moisture parameters; and acetaldehyde exhibited a strong negative correlation
with the moisture parameters. In addition, nearly all of the correlations with scalar
wind speed were negative.
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• At TUMS, formaldehyde exhibited strong positive correlations with the temperature
parameters; acrylonitrile exhibited strong positive correlations with the temperature
and moisture parameters; and all of the correlations with scalar wind speed were
negative.
• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor for
GPMS and TUMS.
• According to NATA, benzene had the highest cancer risk estimate for GPMS and
TUMS and acrolein was the only pollutant with a noncancer HQ greater than 1.0.
Carbon tetrachloride had the highest cancer risk approximations for these sites, while
acrolein had the highest noncancer risk approximations.
• Benzene was the highest emitted pollutant with a cancer risk factor in Harrison
County. Benzene also had the highest toxicity-weighted emissions in this county.
Dichloromethane was the highest emitted pollutant with a cancer risk factor in Lee
County, while hexavalent chromium had the highest cancer toxicity-weighted
emissions for this county.
• Toluene was the highest emitted pollutant with a noncancer risk factor in Lee County,
while hydrochloric acid was the highest emitted pollutant with a noncancer risk factor
in Harrison County. Acrolein had the highest noncancer toxicity-weighted emissions
for both counties.
Missouri.
• The NATTS site in Missouri is located in St. Louis.
• Back trajectories originated from a variety of directions at S4MO, although the bulk
of the trajectories originated from the southwest and northwest. The 24-hour air shed
domain for S4MO was similar in size to other monitoring sites.
• The wind rose for S4MO shows that calm winds prevailed near this site, although
south-southeasterly and southerly winds were also observed frequently.
• S4MO sampled for VOC, carbonyls, metals (PMio), and hexavalent chromium.
• The following pollutants were identified as pollutants of interest for S4MO:
acetaldehyde, acrolein, arsenic, benzene, 1,3-butadiene, cadmium, carbon
tetrachloride, formaldehyde, manganese, />-dichlorobenzene, and tetrachloroethylene.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for S4MO, followed by acetaldehyde and benzene. S4MO had the
highest daily average concentration of arsenic (PMio) and the third highest
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concentration of manganese (PMio), among all the monitoring sites sampling
metals.
• At S4MO, formaldehyde concentrations were highest in the summer and lowest in the
winter. Also, acetaldehyde concentrations were highest in the summer and fall and
lowest in the winter.
• Carbonyl, VOC, and metals sampling have been conducted at S4MO for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
average rolling concentrations of arsenic have changed little over the sampling
periods; the median and average rolling concentration of benzene have a slight
decreasing trend over the sampling periods; as the detection rate for 1,3-butadiene
increased (due to lower detection limits), the spread between the statistical metrics
increased; and the median and average concentrations of formaldehyde exhibited a
slight decreasing trend over the sampling period.
• Formaldehyde exhibited strong positive correlations with the temperature and
moisture parameters and nearly all of the correlations with scalar wind speed were
negative.
• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor.
• Benzene had the highest NATA-modeled cancer risk for S4MO, while carbon
tetrachloride had the highest cancer risk approximation. Acrolein had the highest
NATA-modeled noncancer risk and noncancer risk approximation.
• Benzene was the highest emitted pollutant with a cancer risk factor in St. Louis (city),
while toluene was the highest emitted pollutant with a noncancer risk factor. Benzene
also had the highest cancer toxicity-weighted emissions, while acrolein had the
highest noncancer toxicity-weighted emissions in St. Louis (city).
New Jersey.
• The four UATMP sites in New Jersey are located in Camden (CANJ), Chester
(CHNJ), Elizabeth (ELNJ), and New Brunswick (NBNJ).
• Back trajectories originated from a variety of directions at the New Jersey sites,
although less frequently from the east and southeast. The predominant direction of
trajectory origin was from the southwest and northwest.
• The wind roses for the New Jersey sites show that southerly, southwesterly, and
westerly winds were frequently recorded near CANJ; calm winds were observed for
nearly 60 percent of observations near CJrDSTJ and NBNJ; and westerly, southwesterly,
and northeasterly winds were frequently observed near ELNJ.
• All four New Jersey sites sampled for VOC and carbonyls.
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• The pollutants of interest common to all four sites were acetaldehyde, acrolein,
benzene, 1,3-butadiene, carbon tetrachloride, formaldehyde, and tetrachloroethylene.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for CANJ, CHNJ, and NBNJ. Acetaldehyde had the highest daily
average concentration for ELNJ.
• Compared to other program sites, ELNJ had the second highest daily average
concentration of acetaldehyde; the fourth highest daily average concentration of
formaldehyde; and the tenth highest daily average concentration of benzene. CANJ
had the ninth highest daily average concentration of formaldehyde, acrolein, andp-
dichlorobenzene.
• While concentrations of most of the pollutants of interest for the New Jersey sites did
not vary significantly from season to season, formaldehyde was highest during the
summer at CANJ and NBNJ; concentrations of acetaldehyde were highest during the
summer and autumn; and concentrations of 1,3-butadiene were highest in autumn and
winter at ELNJ.
• Carbonyl and VOC sampling have been conducted at CANJ for at least five
consecutive years; thus three-year rolling metrics were calculated. CANJ has been a
UATMP site longer than any other (since 1994). In brief, a slight decreasing trend in
the average and median concentration of benzene is evident beginning around the
1997-1999 time frame through the end of the sampling period; the minimum and first
quartile for 1,3-butadiene were both zero for all time frames except 2005-2007,
reflecting the influence of many non-detects; beginning with the 1998-2000 time
frame, the average concentration of formaldehyde began to decrease.
• Carbonyl and VOC sampling have been conducted at CHNJ for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
average, maximum, and median concentrations of benzene have decreased slightly;
although the detection rate of 1,3-butadiene increased over the sampling period, the
detection rate is still rather low compared to other monitoring sites; the average and
median concentrations of formaldehyde have also have decreased slightly.
• Carbonyl and VOC sampling have been conducted at ELNJ for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
average and median concentrations of benzene have decreased; although the average
and median concentrations of 1,3-butadiene have decreased slightly across much of
the sampling period, concentrations increased slightly during the 2005-2007 time
frame; concentrations of formaldehyde have been increasing at ELNJ.
• Carbonyl and VOC sampling have been conducted at NBNJ for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
average and median concentrations of benzene have decreased; although the average
and median concentrations of 1,3-butadiene have increased across much of the
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sampling period, this is likely due to the increased detection rate (due to lowered
detection limits); the maximum concentration of formaldehyde, measured in 2004,
was nearly four times the maximum concentrations shown for other periods not
including 2004.
• Acetaldehyde exhibited strong positive correlations with the temperature and
moisture variables for ELNJ. While this was also true for acetaldehyde and the
temperature parameters for CANJ, the correlations were not quite as strong.
• Formaldehyde exhibited strong positive correlations with the temperature and
moisture variables for CANJ. While this was also true for/>-dichlorobenzene and the
temperature parameters for CANJ, although the correlations were not as strong.
• Carbon tetrachloride exhibited strong positive correlations with the temperature and
moisture variables for NBNJ.
• Weak, moderate, and strong negative correlations were calculated for the pollutants
of interest for the New Jersey monitoring sites and wind speed.
• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor for
each of the New Jersey monitoring sites.
• According to NAT A, benzene had the highest cancer risk estimate for all four New
Jersey monitoring sites and acrolein was the only pollutant with a noncancer HQ
greater than 1.0. Carbon tetrachloride had the highest cancer risk approximation for
CANJ and NBNJ, while acetaldehyde had the highest cancer risk approximation for
ELNJ and CJrDSTJ. Acrolein had the highest noncancer risk approximations for three
of the four sites (noncancer approximations could not be calculated for VOC for
CHNJ).
• Benzene was the highest emitted pollutant with cancer UREs in Union, Middlesex,
Morris, and Camden Counties. Benzene also had the highest toxicity-weighted
emissions in each county.
• Toluene was the highest emitted pollutant with a noncancer risk factor in all four
counties, while acrolein had the highest noncancer toxicity-weighted emissions for
each county.
New York.
• The two New York monitoring sites, located in Rochester (ROCH) and New York
City (BXNY), are both NATTS sites.
• Back trajectories originated from a variety of directions at BXNY, although rarely
from the east and southeast. Trajectories primarily originated from the southwest and
west at ROCH. Due to the late start date, the composite trajectory maps include
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approximately a quarter of the back trajectories that would be shown for a site
sampling for the entire year.
• Winds from a variety of directions were observed near BXNY, although southerly
and northwesterly winds were observed the most. Winds from the south, southwest,
and west were observed more frequently than winds from other directions near
ROCH.
• BXNY and ROCH sampled for hexavalent chromium only.
• Hexavalent chromium failed one screen for ROCH, and did not fail any screens for
BXNY.
• Compared to other program sites sampling hexavalent chromium, ROCH and BXNY
had the sixth and eighth highest daily average concentration of hexavalent chromium,
respectively.
• All of the Pearson correlations for BXNY were weak. The correlations for ROCH
were higher, although the low number of measured detections may have skewed the
correlations.
• None of the daily measurements or concentration averages for hexavalent chromium
exceeded any of the MRL risk values.
• The NATA-modeled concentration and risk estimates for hexavalent chromium for
the two New York monitoring sites were similar to each other. Annual averages (and
therefore cancer and noncancer surrogate risk approximations) could not be
calculated for hexavalent chromium due to the sampling duration criteria.
• Tetrachloroethylene was the highest emitted pollutant with a cancer risk factor in the
Bronx, while benzene was the highest emitted pollutant with a cancer risk factor in
Monroe County. Naphthalene had the highest cancer toxicity-weighted emissions in
the Bronx while benzene had the highest cancer toxicity-weighted emissions in
Monroe County.
• Toluene was the highest emitted pollutant with a noncancer risk factor in Monroe
County, while methanol was the highest emitted pollutant the Bronx. Acrolein had
the highest noncancer toxicity-weighted emissions for both counties.
Oklahoma.
• Three Oklahoma monitoring sites are located in Tulsa (TOOK, TSOK, TUOK), and
the fourth is located outside Tulsa, in Pryor (CNEP). All four are UATMP sites.
• Although back trajectories originated from a variety of directions at the Oklahoma
sites, a majority of the trajectories originated from the south or northwest. The 24-
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hour air shed domains for these four sites were somewhat larger in size than other
monitoring sites as the furthest away a trajectory originated was greater than 900
miles away.
• The wind roses show that southerly winds prevailed near each monitoring site.
• The three Tulsa sites sampled for VOC, carbonyls, and metals (TSP); CNEP sampled
for VOC.
• The pollutants of interest common to all four sites were acrolein, benzene, 1,3-
butadiene, and carbon tetrachloride. If CNEP, which is the limiting factor partly due
to sampling only VOC, is excluded, the list of common pollutants also includes
acetaldehyde, formaldehyde, /?-dichlorobenzene, tetrachloroethylene, arsenic, and
manganese.
• Of the pollutants of interest, acrolein had the highest daily average concentration for
CNEP. CNEP had the second highest daily average concentration of acrolein among
all NATTS and UATMP sites.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for all three Tulsa sites. The Tulsa sites had the fourth, sixth, and
seventh highest daily average concentrations of acrolein among all NATTS and
UATMP sites. TOOK and TUOK also had the second and eighth highest daily
average concentration of benzene.
• 1,3-Butadiene exhibited strong negative Pearson correlations with the maximum,
average, and dew point temperatures at CNEP. At the Tulsa sites, formaldehyde and
acetaldehyde exhibited strong positive correlations with the maximum, average, dew
point, and wet bulb temperatures; manganese exhibited strong negative correlations
with relative humidity for all three sites.
• All four seasonal averages of acrolein exceeded the intermediate MRL for all four
sites.
• For CNEP, the cancer risk estimates from NATA for some pollutants, such as
benzene, were very similar to the cancer risk approximations, but very different for
others, such as acrylonitrile.
• According to NATA, benzene had the highest cancer risk estimates for the Tulsa
sites. Benzene also had the highest cancer risk approximations for these sites.
Acrolein had the highest NATA-modeled noncancer risk and noncancer risk
approximation for TOOK, TSOK, and TUOK.
• Benzene was the highest emitted pollutant with a cancer risk factor in Mayes and
Tulsa Counties. Arsenic had the highest cancer toxicity-weighted emissions for
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Mayes County, while benzene had the highest cancer toxicity-weighted emissions for
Tulsa County.
• Toluene was the highest emitted pollutant with a noncancer risk factor in both
counties, while acrolein had the highest noncancer toxicity-weighted emissions.
Puerto Rico.
• The two UATMP sites in Puerto Rico are located in Barceloneta (BAPR) and San
Juan (SJPR).
• Back trajectories originated from the northeast, east, and southeast of the monitoring
sites. Back trajectories did not originate from any other directions.
• The wind roses show that easterly and southeasterly winds were prevalent near these
monitoring sites.
• BAPR and SJPR both sampled for VOC and carbonyls.
• The pollutants of interest common to both sites were acetaldehyde, acrolein, benzene,
1,3-butadiene, carbon tetrachloride, formaldehyde, and/>-dichlorobenzene.
• Of the pollutants of interest, dichloromethane had the highest daily average
concentration for BAPR and acetaldehyde had the highest daily average concentration
for SJPR. SJPR had the highest daily average concentration of acetaldehyde andp-
dichlorobenzene among all monitoring sites.
• Average concentrations of dichloromethane for BAPR were higher than other
program sites. However, an annual average concentration could not be calculated,
due to the short sampling duration, to provide a cancer risk approximation.
• Seasonal averages could only be calculated for winter and spring and annual averages
were not calculated because BAPR and SJPR stopped sampling in June.
• Strong positive Pearson correlations were calculated between formaldehyde and
maximum temperature for both sites. Although this trend was also true of average
temperature for BAPR, the correlation between average temperature and
formaldehyde at SJPR was weaker. While the pollutants of interest exhibited weak
correlations with wind speed, nearly all were negative.
• The winter and spring seasonal averages of acrolein exceeded the intermediate MRL
for BAPR and SJPR.
• According to NATA, dichloromethane had the highest concentration and cancer risk
for BAPR, which was the second highest cancer risk estimate for any pollutant that
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failed a screen in a census tract with a UATMP or NATTS monitoring site. The only
pollutant with a noncancer HQ greater than 1.0 for BAPR was acrolein.
• According to NATA, benzene had the highest cancer risk estimates for the SJPR
monitoring site, while acrolein had the highest NATA-modeled noncancer risk.
• Because annual averages could not be calculated, cancer and noncancer surrogate risk
approximations for the Puerto Rico monitoring sites could not be calculated.
• Dichloromethane was the highest emitted pollutant with a cancer risk factor in the
Barceloneta Municipio, while benzene was the highest emitted pollutant with a cancer
risk factor in the Bayamon Municipio. Hexavalent chromium had the highest
toxicity-weighted emissions in both municipios.
• Dichloromethane was the highest emitted pollutant with a noncancer risk factor in the
Barceloneta Municipio, while toluene was the highest emitted pollutant with a
noncancer risk factor in the Bayamon Municipio. Acrolein had the highest toxicity-
weighted emissions in both municipios.
Rhode Island.
• The Rhode Island monitoring site is located in Providence and is a NATTS site.
• Back trajectories originated from a variety of directions at PRRI, although
infrequently from the southeast. The 24-hour air shed domain for PRRI was similar
in size to other monitoring sites.
• The wind rose shows that westerly winds were prevalent near PRRI.
• PRRI sampled for hexavalent chromium only. Hexavalent chromium failed two
screens for this site.
• Compared to other program sites sampling hexavalent chromium, PRRI had the
eighth lowest daily average concentration.
• Correlations between concentrations of hexavalent chromium and selected
meteorological parameters were weak.
• None of the daily measurements or concentration averages of hexavalent chromium
exceeded any of the MRL risk values.
• The cancer risk from hexavalent chromium according to NATA was an order of
magnitude higher than the cancer risk approximation. The noncancer risk according
to NATA and the noncancer risk approximation for hexavalent chromium were both
low.
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• Benzene was the highest emitted pollutant with a cancer risk factor in Providence
County, while toluene was the highest emitted pollutant with a noncancer risk factor.
Benzene also had the highest cancer toxicity-weighted emissions, while acrolein had
the highest noncancer toxicity-weighted emissions in Providence County.
South Carolina.
• The South Carolina monitoring site is located in near Chesterfield and is a NATTS
site.
• Back trajectories originated from a variety of directions at CHSC. The 24-hour air
shed domain for CHSC was similar in size to other monitoring sites.
• The wind rose shows that calm winds were prevalent near CHSC. For winds greater
than two knots, southwesterly winds were observed most frequently.
• CHSC sampled for hexavalent chromium only. Although hexavalent chromium did
not fail any screens, analyses were still conducted on samples for this pollutant.
• Compared to other program sites sampling hexavalent chromium, CHSC had the
lowest daily average concentration.
• Correlations between concentrations of hexavalent chromium and selected
meteorological parameters were weak.
• None of the daily measurements or concentration averages of hexavalent chromium
exceeded any of the MRL risk values.
• The cancer and noncancer risks according to NAT A and the surrogate risk
approximations for hexavalent chromium were low.
• Benzene was the highest emitted pollutant with a cancer risk factor in Chesterfield
County, while toluene was the highest emitted pollutant with a noncancer risk factor.
Benzene also had the highest cancer toxicity-weighted emissions, while acrolein had
the highest noncancer toxicity-weighted emissions.
South Dakota.
• The two UATMP sites in South Dakota are located in Sioux Falls (SFSD) and Custer
(CUSD).
• Back trajectories originated from a variety of directions at the South Dakota sites.
The predominant direction of trajectory origin for CUSD was west or northwest,
while the predominant direction of trajectory origin for SFSD was from the southwest
and northwest. The 24-hour air shed domain for CUSD was smaller than the air shed
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domain for SFSD. The air shed domain for SFSD was the largest of all monitoring
sites.
• The wind rose for CUSD shows that westerly winds were prevalent near this site,
while southerly and northwesterly winds prevailed near SFSD.
• CUSD and SFSD sampled for VOC, SNMOC, and carbonyl compounds.
• The pollutants of interest common to both sites were acetaldehyde, acrolein, benzene,
1,3-butadiene, carbon tetrachloride, and formaldehyde.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for both sites. CUSD and SFSD had the sixth and seventh highest daily
average concentrations of acrylonitrile, respectively, compared to all monitoring sites
sampling VOC.
• Concentrations of acetaldehyde and formaldehyde were highest during the summer at
CUSD. The concentrations of the other pollutants of interest did not vary
significantly from season to season for CUSD or SFSD.
• Carbonyl, SNMOC, and VOC sampling has been conducted at CUSD for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
central tendency statistics for benzene were very similar in value, reflecting relatively
little variability in the concentrations measured for each period; the rolling average
concentration of 1,3-butadiene increased over time, demonstrating the effects of the
increased detection rate; the increasing "closeness" of the central tendency statistics
indicated a decreasing variability in the formaldehyde concentrations, as did the range
of concentrations detected.
• Carbonyl, SNMOC, and VOC sampling has been conducted at SFSD for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
average rolling concentrations of benzene have decreased since the 2002-2004 time
frame; although the range of 1,3-butadiene concentrations decreased over time, the
central tendency statistics were very low, demonstrating the effects of large numbers
of non-detects; the rolling average concentrations of formaldehyde changed little
across the periods.
• At CUSD, acrylonitrile exhibited strong positive correlations with the average,
maximum, dew point, and wet bulb temperatures and a strong negative correlation
with relative humidity; 1,3-butadiene exhibited strong negative correlations with the
temperature and moisture parameters; and acetaldehyde exhibited a strong negative
correlation with sea level pressure.
• Although most of the correlations of the pollutants of interest were weak at SFSD,
acrolein exhibited strong positive correlations with the temperature and moisture
parameters.
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• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor for
CUSD and SFSD. Additionally, one measured detection of formaldehyde exceeded
the ATSDR acute MRL.
• According to NATA, carbon tetrachloride had the highest cancer risk estimate for
CUSD, while benzene had the highest cancer risk estimate for SFSD. Acrolein was
the only pollutant with a noncancer HQ greater than 1.0. Carbon tetrachloride had the
highest cancer risk approximations for these sites, while acrolein had the highest
noncancer risk approximations.
• Benzene was the highest emitted pollutant with a cancer risk factor in both Custer and
Minnehaha Counties. Benzene also had the highest toxicity-weighted emissions in
both counties.
• Toluene was the highest emitted pollutant with a noncancer risk factor in Custer and
Minnehaha Counties, while acrolein had the highest noncancer toxicity-weighted
emissions for both counties.
Tennessee.
• The Tennessee monitoring sites (LDTN and MSTN) are UATMP sites located in
Loudon, southwest of Knoxville.
• Back trajectories originated from a variety of directions at the sites, although less
frequently from the northwest, north, and northeast. The air shed domains were
similar in size compared to other monitoring sites, as the farthest away a back
trajectory originated was approximately 800 miles.
• The wind roses show that calm winds were prevalent near the monitoring sites,
although southwesterly winds were observed the most for winds greater than two
knots.
• LDTN and MSTN sampled for VOC and carbonyl compounds.
• The pollutants of interest common to both sites were acetaldehyde, acrolein, benzene,
1,3-butadiene, carbon tetrachloride, and formaldehyde.
• Of the pollutants of interest for LDTN, carbon disulfide had the highest daily average
concentration. The daily average concentration of carbon disulfide for LDTN was the
highest average concentration for this pollutant of all NATTS and UATMP sites.
• Of the pollutants of interest for MSTN, formaldehyde had the highest daily average
concentration. In addition, formaldehyde concentrations were highest in the summer.
• Carbonyl and VOC sampling has been conducted at LDTN for at least five
consecutive years; thus three-year rolling metrics were calculated. In brief, the
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median and average rolling concentrations of benzene have a decreasing trend over
the sampling periods; the central tendency statistics for 1,3-butadiene have increased
over the sampling periods, due to the increasing detection rate (and the decreased
MDL); and the average rolling concentration of formaldehyde decreased over the
sampling periods.
• Formaldehyde exhibited strong positive Pearson correlations with average, maximum,
dew point, and wet bulb temperatures at both sites. Acetaldehyde also exhibited
strong positive correlations with the temperature parameters at LDTN. In addition,
all of the correlations between the pollutants of interest and scalar wind speed were
negative at both sites.
• The seasonal averages of acrolein exceeded the ATSDR intermediate MRL risk factor
for both sites.
• According to NATA, benzene had the highest cancer risk estimates for both LDTN
and MSTN and acrolein was the only pollutant with a noncancer HQ greater than 1.0.
Carbon tetrachloride had the highest cancer risk approximation for both sites, while
acrolein had the highest noncancer risk approximation for both sites.
• Benzene was the highest emitted pollutant with a cancer risk factor in Loudon
County, while carbon disulfide was the highest emitted pollutant with a noncancer
risk factor. Benzene also had the highest cancer toxicity-weighted emissions, while
acrolein had the highest noncancer toxicity-weighted emissions in Loudon County.
Texas.
• The Texas monitoring sites are NATTS sites located in Deer Park (CAMS 35) and
(CAMS 85).
• Back trajectories originated from a variety of directions at the Texas monitoring site,
although most trajectories originated from the southeast at CAMS 35 and from the
southeast and south at CAMS 85. The 24-hour air shed domain for CAMS 85 was
larger in size than CAMS 35 and most other monitoring sites, as the farthest away a
back trajectory originated was 900 miles.
• The wind roses show that southeasterly and southerly winds prevailed near both sites,
although northerly winds were also observed somewhat frequently near the sites.
• The CAMS 35 and CAMS 85 monitoring sites sampled VOC only.
• The pollutants of interest common to both sites were acrolein, benzene, 1,3-
butadiene, and carbon tetrachloride.
• Of the pollutants of interest, benzene had the highest daily average concentration for
both sites.
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• CAMS 35 had the highest daily average concentration of 1,3-butadiene, third highest
daily average concentration of acrylonitrile, and fourth highest daily average
concentration of benzene among sites sampling VOC. In addition, CAMS 85 had the
fifth highest daily average concentration of acrylonitrile.
• Concentrations of benzene were lowest during the winter and highest during the fall
at CAMS 35. The rest of the concentrations of the pollutants of interest did not vary
significantly from season to season at the Texas sites.
• Benzene exhibited a strong negative Pearson correlation with wind speed at
CAMS 85. Acrylonitrile exhibited a strong negative correlation with relative
humidity, and/>-dichlorobenzene exhibited a strong negative correlation with wind
speed at CAMS 35.
• The seasonal averages of acrolein exceeded the ATSDR intermediate MRL risk factor
for both sites.
• According to NATA, benzene had the highest cancer risk estimates for both sites and
acrolein was the only pollutant with a noncancer HQ greater than 1.0. Carbon
tetrachloride had the highest cancer risk approximation for CAMS 85, while 1,3-
butadiene had the highest cancer risk approximation for CAMS 35. Acrolein had the
highest noncancer risk approximation for both sites.
• Benzene was the highest emitted pollutant with a cancer risk factor in Harris and
Harrison Counties, while toluene was the highest emitted pollutant with a noncancer
risk factor in both counties. Benzene had the highest cancer toxicity-weighted
emissions in Harris County, while hexavalent chromium had the highest cancer
toxicity-weighted emissions in Harrison County. Acrolein had the highest noncancer
toxicity-weighted emissions for both counties.
Utah.
• The NATTS site in Utah is located in Bountiful.
• The majority of trajectories originated from the south and southwest of BTUT,
although another cluster of trajectories originated from the northwest. The 24-hour
air shed domain for BTUT was slightly smaller in size compared to other monitoring
sites as the furthest away a trajectory originated was nearly 500 miles away.
• The wind rose shows that southerly and southeasterly winds were prevalent near
BTUT.
• BTUT sampled for VOC, carbonyls, SNMOC, metals (PMio), and hexavalent
chromium.
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• The following pollutants were identified as pollutants of interest for BTUT:
acetaldehyde, acrolein, arsenic, benzene, 1,3-butadiene, cadmium, carbon
tetrachloride,/>-dichlorobenzene, formaldehyde, manganese, and tetrachloroethylene.
• Of the pollutants of interest, formaldehyde had the highest daily average
concentration for BTUT, followed by acetaldehyde and benzene. Additionally,
BTUT had the third highest daily average concentration of arsenic (PMio) and fourth
highest concentration of manganese (PMio) among sites sampling PMio metals.
• Concentrations of 1,3-butadiene were higher in the winter and autumn. Most of the
concentrations of the pollutants of interest for BTUT did not vary significantly by
season.
• Carbonyl, VOC, SNMOC, and metals sampling have been conducted at BTUT for at
least five consecutive years; thus three-year rolling metrics were calculated. In brief,
the average rolling concentrations of arsenic have decreased; the median and average
rolling concentrations of benzene have a slight decreasing trend over the sampling
periods, based on measurements from both methods; as the detection rate for 1,3-
butadiene increased (due to lower detection limits), the rolling average concentrations
increased; and the average rolling concentrations of formaldehyde increased slightly
from 2003-2005 to 2004-2006, then decreased to the previous level over the 2005-
2007 time frame.
• Strong positive Pearson correlations were calculated between manganese and the
temperature and moisture parameters (except relative humidity). 1,3-Butadiene
exhibited a strong positive correlation with sea level pressure. Benzene and 1,3-
butadiene both exhibited strong negative correlations with wind speed, although all
correlations with wind speed were negative.
• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor.
• Benzene had the highest NATA-modeled cancer risk and the highest cancer risk
approximation for BTUT. Acrolein had the highest NATA-modeled noncancer risk
and noncancer risk approximation.
• Benzene was the highest emitted pollutant with a cancer risk factor in Davis County,
while toluene was the highest emitted pollutant with a noncancer risk factor. Benzene
also had the highest cancer toxicity-weighted emissions, while acrolein had the
highest noncancer toxicity-weighted emissions in Davis County.
Vermont.
• The Vermont monitoring site is located in Underhill and is a NATTS site.
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• Back trajectories originated from a variety of directions at UNVT, although less
frequently from the east and southeast. The 24-hour air shed domain for UNVT was
similar in size to other monitoring sites.
• The wind rose shows that calm winds were prevalent near UNVT. For winds greater
than two knots, northerly and southerly winds were observed most frequently.
• UNVT sampled for hexavalent chromium only. Although hexavalent chromium did
not fail any screens, analyses were still conducted on samples for this pollutant.
• Compared to other program sites sampling hexavalent chromium, UNVT had the fifth
lowest daily average concentration.
• Correlations between concentrations of hexavalent chromium and selected
meteorological parameters were weak.
• None of the daily measurements or concentration averages of hexavalent chromium
exceeded any of the MRL risk values.
• The cancer and noncancer risks according to NATA and the surrogate risk
approximations for hexavalent chromium were low.
• Benzene was the highest emitted pollutant with a cancer risk factor in Chittenden
County, while toluene was the highest emitted pollutant with a noncancer risk factor.
Benzene also had the highest cancer toxicity-weighted emissions, while acrolein had
the highest noncancer toxicity-weighted emissions.
Washington.
• The NATTS site in Washington is located in Seattle.
• Back trajectories originated from a variety of directions at SEW A, although
infrequently from the southeast. The 24-hour air shed domain for SEWA was
comparable in size to other monitoring sites.
• The wind rose shows that southerly and south-southeasterly winds were prevalent
near SEWA.
• SEWA sampled for VOC, carbonyls, metals, and hexavalent chromium.
• The following pollutants were identified as pollutants of interest for SEWA:
acetaldehyde, acrolein, arsenic, benzene, 1,3-butadiene, carbon tetrachloride,
formaldehyde, manganese, nickel, and tetrachloroethylene.
• Of the pollutants of interest, formaldehyde and acetaldehyde had the highest daily
average concentrations for SEWA.
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• All of the Pearson correlations with wind speed were negative.
• All four seasonal averages of acrolein exceeded the intermediate MRL risk factor.
• Benzene had the highest NATA-modeled cancer risk for SEW A, and the second
highest cancer risk approximation. Carbon tetrachloride had the highest cancer risk
approximation.
• Acrolein had the highest NATA-modeled noncancer risk and noncancer risk
approximation for SEWA.
• Benzene was the highest emitted pollutant with a cancer risk factor in King County,
while toluene was the highest emitted pollutant with a noncancer risk factor. Benzene
also had the highest cancer toxicity-weighted emissions, while acrolein had the
highest noncancer toxicity-weighted emissions in King County.
Wisconsin.
• The Wisconsin monitoring site is located in Mayville and is a NATTS site.
• Back trajectories originated from a variety of directions at MVWI, although less
frequently from the east. The 24-hour air shed domain for MVWI was one of the
largest in size compared to other monitoring sites.
• The wind rose shows that calm winds were prevalent near MVWI. For winds greater
than two knots, westerly and northwesterly winds were observed most frequently.
• MVWI sampled for hexavalent chromium only. Although hexavalent chromium did
not fail any screens, analyses were still conducted on samples for this pollutant.
• Compared to other program sites sampling hexavalent chromium, MVWI had the
fourth lowest daily average concentration.
• Correlations between concentrations of hexavalent chromium and selected
meteorological parameters were weak.
• None of the daily measurements or concentration averages of hexavalent chromium
exceeded any of the MRL risk values.
• The cancer and noncancer risks according to NATA and the surrogate risk
approximations for hexavalent chromium were low.
• Benzene was the highest emitted pollutant with a cancer risk factor in Dodge County,
while toluene was the highest emitted pollutant with a noncancer risk factor. Benzene
also had the highest cancer toxicity-weighted emissions, while acrolein had the
highest noncancer toxicity-weighted emissions.
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32.1.3 Composite Site-level Summary
$ Twenty-two pollutants were identified as site-specific pollutants of interest.
Acetaldehyde and formaldehyde were the two most common pollutants of interest
among the monitoring sites. All sites (33) that sampled carbonyls had acetaldehyde
and formaldehyde as pollutants of interest. Benzene, acrolein, 1,3-butadiene, and
carbon tetrachloride were the most common VOC pollutants of interest. Every site
that sampled VOC (27) had these as pollutants of interest.
$ Among the site-specific pollutants of interest, formaldehyde frequently had the
highest daily average concentration among the monitoring sites; formaldehyde had
the highest daily average concentration for 25 sites. Acetaldehyde had the next
highest daily average concentration at five sites.
$ Pearson correlations calculated between formaldehyde and the temperature
parameters (maximum and average temperature) for many of the monitoring sites
were moderately strong and positive. This indicates that as temperatures increase,
concentrations of formaldehyde also increase. At some of these same sites, the
summer formaldehyde average concentration tended to be higher than other seasons,
supporting this observation.
$ Pearson correlations calculated between most of the pollutants of interest and the
scalar wind speed at most monitoring sites tended to be negative. This indicates that
as wind speed decreases, concentrations of the pollutants of interest increase.
$ Carbon tetrachloride often had relatively high cancer risk approximations based on
annual averages among the monitoring sites, but tended to have relatively low
emissions and toxicity-weighted emissions according to the NEI emissions inventory.
This suggests that this pollutant is present in "background" levels of ambient air; that
is, it is consistently present at similar levels at any given location. Although
production of this pollutant has declined sharply over the last 30 years due to its role
as an ozone depleting substance, it has a relatively long atmospheric lifetime.
$ Acrolein emissions and mass concentrations were relatively low when compared to
other pollutants. However, due to the high toxicity of this pollutant, low mass
concentrations translated into very high noncancer surrogate risk approximations.
This trend was also evident when the acrolein emissions were toxicity-weighted; the
toxicity-weighted value was often several orders of magnitude higher than other
pollutants. Acrolein is a national noncancer risk driver according to NATA.
$ Several characterization parameters presented, such as average daily traffic volume
near the monitoring sites, are provided in AQS by the agency responsible for the site.
Because many of these parameters were 10 years old or more, updating such
information has been a recommendation in previous years' UATMP reports. This
allows the data to more accurately reflect current conditions near the sites, and in turn
provides higher quality information for understanding the dynamics surrounding each
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monitoring site. This year, more recent traffic volume data were obtained from state
and local agencies. As a result, the impacts of motor vehicle emissions were more
visible in the analyses conducted.
$ When comparing the highest emitted pollutants for a specific county with the
pollutants with the highest toxicity-weighted emissions, the lists tended to be more
similar for the pollutants with cancer UREs than for pollutants with noncancer RfCs.
32.1.4 Data Quality Summary
Method precision was analyzed for the 2007 NATTS and UATMP monitoring efforts
using relative percent difference (RPD), coefficient of variation (CV), and average concentration
difference calculations based on duplicate, collocated, and replicate samples. The overall
method precision for some methods was well within data quality objective specifications and
monitoring method guidelines (TO-11A and IO-3.5), while other methods exceeded the data
quality objective specifications (TO-15/SNMOC, TO-13A, and hexavalent chromium).
Sampling and analytical method accuracy is assured by using proven methods, as demonstrated
by third-party analysis of proficiency test audit samples, and following strict quality control and
quality assurance guidelines.
32.2 Recommendations
In light of the results of the data analyses from the 2007 NATTS and UATMP, a number
of recommendations for future ambient air monitoring efforts are presented below.
• Encourage EPA to promulgate ambient air standards for HAPs. Several of the
pollutants sampled during the 2007 program year exceeded risk screening factors
developed by various government agencies. One way to reduce the risk to human
health would be to develop standards similar to the NAAQS for pollutants that
frequently exceed published risk screening levels.
• Incorporate/Update Risk in State Implementation Plans (SIPs). Use risk calculations
to design State Implementation Plans (SIPs) to implement policies that will reduce the
potential for human health risk. This would be easier to enforce if ambient standards
for certain HAPs were developed (refer to above recommendation).
• Encourage state/local/tribal agencies to develop and/or verify HAP and VOC
emission inventories. State/local/tribal agencies should use the data collected from
the NATTS and UATMP sites to develop and validate emissions inventories, or at the
very least, identify and/or verify emission sources of concern. Ideally,
state/local/tribal agencies would compare the ambient monitoring results with an
emission inventory for source category completeness. The emissions inventory could
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then be used to develop modeled concentrations useful to compare against ambient
monitoring data.
Continue to identify and implement improvements to the sampling and analytical
methods. The improvements made to the analytical methods prior to the 1999-2000
UATMP allowed for the measurement of ambient air concentrations of 11 pollutants
that were not measured during previous programs. This improvement provides
sponsoring agencies and a variety of interested parties with important information
about air quality within their urban areas. Further research is encouraged to identify
other method improvements that would allow the characterization of an even wider
range of components in urban air pollution and enhance the ability of the methods to
quantify all cancer and noncancer pollutants to at least their levels of concern (risk
screening concentrations).
Require consistency in sampling and analytical methods. The development of the
NATTS program is evidence that there are inconsistencies in collection and analytical
methods that make data comparison difficult across agencies. Encouraging agencies
to use documented, consistent methods is integral to the identification of trends and
the impacts of regulation.
Strive to develop standard conventions for interpreting air monitoring data. The lack
of consistent approaches to present and summarize ambient air monitoring data
complicates direct comparisons between different studies. Thought should be given
to the feasibility of establishing standard approaches for analyzing and reporting air
monitoring data for programs with similar objectives.
Prepare a report characterizing multiple years of NATTS and UATMP data and then
update it yearly to better assess trends and better understand the nature of U.S. urban
air pollution. The value of assessing NATTS and UATMP data from the National
Monitoring Programs is that the data is of known and high quality, using laboratory
analyses based on consistent methods from a single laboratory.
Consider more rigorous study of the impact of automobile emissions on ambient air
quality using multiple year of data. Because many NATTS and UATMP sites have
generated years of continuous data, a real opportunity exists to evaluate the
importance and impact of automobile emissions on ambient air quality. Suggested
areas of study include additional signature compound assessments and parking lot
characterizations.
Encourage continued participation in the National Monitoring Programs. Ongoing
ambient air monitoring at fixed locations can provide insight into long-term trends in
urban air quality and the potential for urban air pollution to cause adverse health
effects among the general population. Therefore, state and local agencies should be
strongly encouraged to either 1) develop and implement their own ambient air
monitoring programs based on proven, consistent sampling and analysis methods and
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EPA technical and quality assurance guidance, or 2) consider participation in the
UATMP.
Encourage year-round participation in the National Monitoring Programs. Many of
the analyses presented in the 2007 report require a full year of data to be most useful
and representative of conditions experienced at each specified location. Therefore,
state and local agencies should be strongly encouraged to implement year-long
ambient air monitoring programs in addition to participating in future monitoring
efforts.
Encourage the monitoring of additional pollutant groups based on the results of data
analyses in the annual report. The risk-based analysis where county-level emissions
are weighted based on toxicity identifies those pollutants whose emission may result
in adverse health effects in a specific area. If a site is not sampling for a pollutant or
pollutant group identified as particularly hazardous in a given area, the agency
responsible for that site should consider sampling for those compounds.
Encourage case studies based on findings from the annual report. Often, the annual
report identifies an interesting tendency or trend, or highlights an event at a particular
site(s). For example, the 2006 annual report included an observation of high
hexavalent chromium concentrations on July 4, 2006. Further examination of the
data in conjunction with meteorological phenomena and potential emissions events or
incidents, or further site characterization may help identify state and local agencies
pinpoint issues affecting air quality in their area.
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33.0 References
AT SDR, 1990. Toxicological Profile for Acrolein. December 1990.
ATSDR, 2007a. "Air Comparison Values in ug/m3." Annmarie DePasquale via Naida Gavrelis.
Aug28, 2007.
ATSDR, 2007b. Agency for Toxics Substances and Disease Registry (ATSDR). Minimal Risk
Levels for Hazardous Substances. November 2007. Internet address:
http ://www. atsdr. cdc. gov/mrls/index.html
ATSDR, 2007c. Toxicological Profile for Acrolein. August 2007. Internet address:
http ://www. atsdr. cdc. gov/toxprofiles/tp 124.html#bookmarkO 1
Conner, et al., 1995. ATransportation-Related Volatile Hydrocarbon Source Profiles Measured
in Atlanta.@ Teri L. Conner, William A. Lonneman, Robert L. Seila. Journal of the Air
and Waste Management Association, 45: 383-394. 1995.
Draxler, R.R. and Rolph, G.D., 2003. HYSPLIT (Hybrid Single-Particle Lagrangian Integrated
Trajectory) Model access via NOAA ARL READY Website
(http://www.arl.noaa.gov/ready/hysplit4.html). NOAA Air Resources Laboratory. Silver
Spring. MD.
EIA, 2007. Energy Information Administration. Motor Vehicle Registration by State.
December 2007.
EPA, 1998. ATechnical Assistance Document for Sampling and Analysis of Ozone Precursors."
U.S. Environmental Protection Agency, National Exposure Laboratory. EPA/600-R-
98/161. September 1998.
EPA, 1999a. ACompendium Method TO-11 A: Determination of Formaldehyde in Ambient Air
Using Adsorbent Cartridge Followed by High Performance Liquid Chromatography
(HPLC).@ U.S. Environmental Protection Agency, Center for Environmental Research
and Information. EPA/625/R-96/010b. January, 1999.
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United States Office of Air Quality Planning and Standards Publication No. EPA-454/R-08-008a
Environmental Protection Emissions, Monitoring and Analysis Division December 2008
Agency Research Triangle Park, NC
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