Soil Screening Guidance: Fact Sheet

This fact sheet summarizes key aspects of EPA's Soil Screening Guidance.

• Fact Sheet: June 1996 (PDF)(12 pp, 213 K, About PDF)
  EPA540/F-95/041

Soil Screening Guidance: User's Guide

The Soil Screening Guidance is a tool developed by EPA to help standardize and accelerate the evaluation and cleanup of contaminated soils at sites on the National Priorities List (NPL) where future residential land use is anticipated. The User's Guide provides a simple step-by-step methodology for environmental science/engineering professionals to calculate risk-based, site-specific soil screening levels (SSLs) for contaminants in soil that may be used to identify areas needing further investigation at NPL sites.

• Soil Screening Guidance: User's Guide (PDF)(49 pp, 425 K, About PDF)
  EPA540/R-96/018, July 1996
• Attachment A: Conceptual Site Model Summary (PDF)(19 pp, 417 K)

The CSM summary forms and worksheets contain the information necessary to determine the applicability of SSLs to the site, and help focus data collection efforts to gather information needed to calculate SSLs.

• Attachment B: Soil Screening DQOs for Surface Soils and Subsurface Soils (PDF)(6 pp, 57 K)

This attachment illustrates the Data Quality Objectives (DQO) Process for surface soil sampling using the Max test, and for subsurface soil sampling. The completion of all the requirements set out in the DQO process during the implementation of the Soil Screening Guidance is needed to satisfy Superfund program objectives.

• Attachment C: Chemical Properties for SSL Development (PDF)(9 pp, 123 K)

This attachment provides the chemical properties necessary to calculate inhalation and migration to ground water SSLs for 110 chemicals commonly found at Superfund sites. Chemical properties for additional contaminants may be found in the Superfund Chemical Data Matrix (SCDM).

• Attachment D: Regulatory and Human Health Benchmarks for SSL Development (PDF)(6 pp, 198 K)

This attachment provides the regulatory and human health benchmarks necessary to calculate SSLs as determined by 1995 versions of either IRIS or HEAST.

This document provides the technical background for the development of methodologies described in the Soil Screening Guidance: User's Guide (EPA/540/R-96/018), along with additional information useful for soil screening. Together, these documents define the framework and methodology to develop soil screening levels (SSLs) for chemicals commonly found at Superfund sites. This document is an updated version of the background document developed in support of the December 30, 1994, draft Soil Screening Guidance. The methodologies described in this document and the Soil Screening Guidance: User's Guide have been revised in response to public comment and extensive peer review. The revisions, along with other technical analyses conducted to address the comments, are described herein.

This background document is presented in six parts:You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.

• Part 1: Introduction (PDF)(9 pp, 170 K) Describes the soil screening process and its application and implementation at Superfund sites.
• Part 2: Development of Pathway-Specific Soil Screening Levels (PDF)(56 pp, 445 K) Describes the methodology used to develop SSLs, including the assumptions and theories used.
• Part 3: Models for Detailed Assessment (PDF)(17 pp, 200 K) Provides information on more detailed models that may be used to develop site-specific SSLs.
• Part 4: Measuring Contaminant Concentrations in Soil (PDF)(52 pp, 575 K) Addresses sampling schemes for measuring soil contaminant levels during the soil screening process.
• Part 5: Chemical-Specific Parameters (PDF)(28 pp, 622 K) provides technical background on the determination of chemical-specific properties for calculating SSLs.
• Part 6: References (PDF)(8 pp, 113 K)
• Appendices
  • Appendix A: Generic SSLs (PDF)(11pp, 523 K)
  • Appendix B: Route-to-Route Extrapolation of Inhalation Benchmarks (PDF)(7 pp, 127 K)
  • Appendix C: Limited Validation of the Jury Infinite Source and Jury Finite Source Models (EQ, 1995) (PDF)(67 pp, 1.3 MB)
  • Appendix D: Revisions to VF and PEF Equations (EQ, 1994b) (PDF)(18 pp, 137 K)
  • Appendix E: Determination of Ground Water Dilution Attenuation Factors (PDF)(43 pp, 1.3 MB)
  • Appendix F: Dilution Factor Modeling Results (PDF)(14 pp, 90 K)
  • Appendix G: Background Discussion for Soil-Plant-Human Exposure Pathway (PDF)(12 pp, 165 K)
  • Appendix H: Evaluation of the Effect on the Draft SSLs of the Johnson and Ettinger Model (EQ, 1994a) (PDF)(17 pp, 221 K)
  • Appendix I: SSL Simulation Results (PDF)(27 pp, 148 K)
  • Appendix J: Piazza Road Simulation Results (PDF)(6 pp, 59 K)
  • Appendix K: Soil Organic Carbon (Koc) / Water (Kow) Partition Coefficients (PDF)(28 pp, 381 K)
  • Appendix L: Koc Values for Ionizing Organics as a Function of pH (PDF)(10 pp, 159 K)
  • Appendix M: Response to Peer-Review Comments on MINTEQA2 Model Results (PDF)(6 pp, 105 K)

Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites

The 2002, "Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites," is a companion guidance to the 1996 Soil Screening Guidance (SSG). It builds upon the soil screening framework for residential land use scenarios established in the original guidance, adding new scenarios for soil screening evaluations. It also updates the residential scenario in the 1996 SSG, adding exposure pathways and incorporating new modeling data. The following specific changes included in this document supersede the 1996 SSG:

• New methods for developing SSLs based on non-residential land use and construction activities;
• New SSL equations for combined exposures via ingestion and dermal absorption;
• Updated dispersion modeling data for the residential air exposure model; and,
• New methods to develop SSLs for the migration of volatiles from subsurface sources into indoor air.

Except for these new equations and updated modeling data, the soil screening process remains the same as the one presented in the 1996 SSG. Therefore, this document presents the process in less detail than the original guidance, and focuses instead on specific elements of soil screening evaluation that differ for residential, non-residential, and construction scenarios.

• Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites (PDF) (106 pp, 1.6 MB, About PDF)
• Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites, Appendix A-C (PDF) (39 pp, 694 K)
• Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites, Appendix D-E (PDF) (42 pp, 515 K)

In 1996, EPA issued the Soil Screening Guidance (SSG) as a tool to help standardize and accelerate the evaluation and cleanup of contaminated soils at sites on the National Priorities List (NPL). The SSG provides site managers with a tiered framework for developing risk-based, site-specific soil screening levels (SSLs) for the protection of human health.

The 1996 SSG quantitatively addressed the following pathways of exposure in a residential setting:

• Direct contact with contaminated soils;
• Inhalation of volatiles and fugitive dusts from undisturbed soils; and,
• Ingestion of groundwater contaminated by the migration of chemicals through site soils.

In addition, the 1996 SSG discussed the potential for dermal exposure to certain contaminants in site soils and for migration of volatile contaminants from the subsurface into indoor air. However, data limitations prevented the program from fully addressing these pathways.

This Supplemental Soil Screening Guidance document is intended as companion guidance to the 1996 SSG for residential use scenarios at NPL sites. It builds upon the soil screening framework established in the original guidance, adding new scenarios for soil screening evaluations. It also updates the residential scenario in the 1996 SSG, adding exposure pathways and incorporating new modeling data. The following specific changes included in this document supersede the 1996 SSG:

• New methods for developing SSLs based on non-residential land use and construction activities;
• New SSL equations for combined exposures via ingestion and dermal absorption;
• Updated dispersion modeling data for the residential air exposure model; and
• New methods to develop SSLs for the migration of volatiles from subsurface sources into indoor air.

Except for these new equations and updated modeling data, the soil screening process remains the same as the one presented in the 1996 SSG. Therefore, this document presents the process in less detail than the original guidance, and focuses instead on specific elements of soil screening evaluation that differ for residential, non-residential, and construction scenarios. Users of this guidance should refer to the SSG User's Guide and Technical Background Document (U.S. EPA, 1996c and 1996b) for additional information on modeling approaches, data sources, and other important details of conducting soil screening evaluations at NPL sites.