Large Flowchart 2 – Soil Background and Risk Assessment

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Soil Background and Risk Assessment

Navigating this Website

1 Introduction

1 Introduction
1.1 Audience
1.2 Purpose
1.3 Use of Background in the Risk Assessment Process
1.4 Limitations

2 Soil Background Definition

2 Soil Background Definition
2.1 Natural Soil Background
2.2 Anthropogenic Ambient Soil Background
2.3 Additional Background Definitions

3 Establishing Soil Background

3 Establishing Soil Background
3.1 Introduction
3.2 Conducting a Soil Background Study
3.3 Choosing an Area for a Soil Background Study
3.4 Sampling
3.5 Laboratory Analysis
3.6 Using an Existing Soil Background Study
3.7 Background Dataset Analysis
3.8 Establishing Default or Site-Specific Soil Background
3.9 Extracting Site-Specific Background Dataset from an On-site Dataset

4 Using Soil Background in Risk Assessment

4 Using Soil Background in Risk Assessment
4.1 Representative Site Concentration to Compare to a BTV
4.2 Using Default Background
4.3 Using Site-Specific Background
4.4 Use of Background for Remedial Goals
4.5 Additional Considerations

5 Geochemical Evaluations

5 Geochemical Evaluations
5.1 Geochemistry Is Not Statistics
5.2 Uses of Geochemical Evaluations
5.3 General Methodology
5.4 Nondetects
5.5 Key Geochemical Processes
5.6 Extracting Background Data from Existing Data

6 Using Geochemical Evaluations in Risk Assessment

6 Using Geochemical Evaluations in Risk Assessment
6.1 Using Geochemical Evaluations During COPC Selection
6.2 Using Geochemical Evaluations During Risk Characterization
6.3 Considerations

7 Environmental Forensics Related to soil Background

7 Environmental Forensics Related to soil Background
7.1 Introduction
7.2 Polycyclic Aromatic Hydrocarbons
7.3 Total Petroleum Hydrocarbons (TPH)
7.4 Polychlorinated Biphenyls (PCBs)
7.5 Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans (PCDD/F)
7.6 Perfluoroalkyl Substances (PFAS)
7.7 Remote Sensing

8 Conceptual Site Model and Data Quality Objectives

8 Conceptual Site Model and Data Quality Objectives
8.1 Conceptual Site Model
8.2 Data Quality Objectives

9 Sampling
9.1 Background Reference Areas
9.2 Sample Depth
9.3 Sample Size
9.4 Sample Methods
9.5 Sampling Design
9.6 Sample Collection Methods
9.7 Sample Handling

10 Analytical Methods

10 Analytical Methods
10.1 Introduction
10.2 Obtaining Reliable Analytical Data
10.3 Analytical Limits
10.4 Sample Preparation
10.5 Analytical Test Methods

11 Statistics

11 Statistics
11.1 Data Requirements
11.2 Data Distribution
11.3 Treatment of Nondetects
11.4 Graphical displays
11.5 Outliers
11.6 Confidence Interval Limit, Coefficient, and Limit
11.7 Statistical Values Used to Represent Background
11.8 Statistical Tests to Compare Site and Background Datasets
11.9 Statistical Software

12 Regulatory Framework from State Survey

12 Regulatory Framework from State Survey
12.1 Description of State Survey
12.2 Overview of State Survey Results
12.3 State Survey Results

13 Existing Guidance and Studies

14 Case Studies

14 Case Studies
14.1 Minnesota Pollution Control Agency (MPCA) Soil Background Case Study
14.2 Former Firearms Training Range Soil Background Case Study
14.3 Region 4 RARE Urban Background Study
14.4 Geochemical Evaluation Case Study—Statistical Outlier is an Uncontaminated Soil Sample
14.5 Geochemical Evaluation Case Study—Statistical Outlier Is a Contaminated Soil Sample
14.6 Geochemical Evaluation Case Study–Contaminated Soil Sample Is Not a Statistical Outlier
14.7 Environmental Forensics Case Study—PAHs from Leaked Petroleum Versus Contaminated Fill

Frameworks
Framework 1
Framework 2
Framework 3

Appendix A. Upper Limits Used to Estimate Background Threshold Values
Appendix B. Index Plots
Appendix C. Additional Sources of Information for PAHs in Soil

Additional Information

Team Contacts
Glossary
Acronyms
Acknowledgments

Large Flowchart 2