Delisting Risk Assessment Software (DRAS)

Region 5 Waste Areas

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EPA Region 6 toxicologists originally developed DRAS in 1998 to analyze risks of wastes petitioned for delisting under §40 Part 260.22 of the Code of Federal Regulations. The DRAS is a user-friendly, stand-alone software program that calculates the potential risks associated with disposing a given waste stream to a landfill or surface impoundment. For a given waste stream, the DRAS calculates both the waste's aggregate risks and also back-calculates each waste constituent's maximum allowable concentration permissible for delisting. DRAS requires the user to assign a target cancer risk and hazard index. EPA Region 5 uses a target cancer risk of 1×10-6 and a target hazard index of 1.0.

The DRAS is a risk assessment tool and, therefore, can only provide risk analyses based on the information input into the program. The risk assessment results are only one factor in a delisting decision. The risk-based approach combines state-of-the-art fate and transport modeling with standardized exposure assessment algorithms to provide sound risk assessment. DRAS has undergone a number of modifications and upgrades. The current contact for DRAS is:

Todd Ramaly, (312) 353-9317 or ramaly.todd@epa.gov
USEPA Region 5
RCRA Programs Branch
77 West Jackson Blvd.
Mail Code LR-8J
Chicago, Illinois 60604

The program is comprised of three (3) components:

1) The Delisting Risk Assessment Software (DRAS) program;

To install DRAS 3.0, click on the following link to download a self-extracting zip file (DRAS3zip.exe) to your computer. Double-click DRAS3zip.exe to extract the three files needed for installation. Extract all three files to the same location on your computer. Once all three files are extracted, double-click the file named setup.exe and follow the on-screen instructions. Once DRAS 3.0 is installed, you may delete or archive the three downloaded files as well as the self-extracting zip file (DRAS3zip.exe)

2) The Delisting Technical Support Document (DTSD);

The DTSD presents extensive information delineating all chemical release, exposure and risk assessment algorithms employed by the DRAS program. Anyone wishing to gain technical insight into the RCRA delisting risk-based process may review information provided in the document. The DTSD is automatically copied into a subfolder on your PC where DRAS 3.0 was installed, and in most installations can be opened from within DRAS. The DTSD is also available below in Adobe Acrobat format. To permit easier downloading, the DTSD and the accompanying appendices have been subdivided. The documentation is indexed as illustrated below:

Chapter 1: Introduction (PDF) (35pp, 260k)
Chapter 2: Estimation of Chemical Releases and Media Concentrations (PDF) (47pp, 862k)
Chapter 3: Exposure Scenario Selection (PDF) (14pp, 125k)
Chapter 4: Quantitative Estimation of Risk (PDF) (89pp, 1.6M)
Chapter 5: Uncertainty (PDF) (9pp, 61k)
Chapter 6: References (PDF) (8pp, 60K)
Appendix A: Appendix with Chemical Data for Waste Constituents in DRAS (PDF) (562pp, 4M)
Appendix A-1b: Appendix with Chemical Data for Waste Constituents in DRAS (PDF) (147pp, 1M)
Appendix A2: Appendix with National Primary Drinking Water Standards (PDF) (3pp, 42K)
Appendix A3: Appendix with Soil Saturation Values (PDF) (7pp, 65K)
Appendix A4: Target Organs and Critical Effects for Compounds with Reference Doses (PDF) (10pp, 187K)
Appendix A5: Appendix with Default Variables: Abbreviations, Units and Values (3pp,42K)

3) The DRAS User's Guide.

The DRAS User's Guide (PDF) (21pp, 609K) provides the DRAS program's minimum and recommended system requirements as well as an overview on how to use the DRAS software. The DRAS User's Guide is automatically copied into a subfolder on your PC where DRAS 3.0 was installed, and in most installations can be opened from within DRAS.

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