Delisting Risk Assessment Software (DRAS)
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.
Background and Updates
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.
You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.
Update September 2010
Problems with the surface impoundment module and the Aggregate Risk and Hazard Quotient Results (PDF) (1pg, 52K) output table have been reported. One problem that results in the incorrect display of the surface impoundment module dilution attenuation factor (DAF) for the GW pathway has been repaired. The new updated program file has been compiled into the install-version available below.
For DRAS version 3 users who have not created user-defined customer chemicals of concern: EPA recommends archiving their current projects (by using the export project function), installing the revised version 3.0 available below, and then importing existing projects into the new version.
For DRAS version 3 users that have created a number of user-defined customer chemicals of concern in their database: a new installation will necessitate re-entry of all custom chemicals because the databasewill be replaced. In this case, the user may wish to upgrade only the executable program file for DRAS instead of installing the whole new version. This corrects the program code, but does not replace the custom chemical database. To replace only the executable file, rename and copy the old version to an archive location and place the version downloaded here in the original DRAS 3.0 install location.
DRASv3.0.exe - Executable File Only (EXE) (1.9MB) October 2010
Please consult the FAQs and Technical Updates for descriptions and solutions to other reported issues with DRAS 3.0.
Todd Ramaly (firstname.lastname@example.org) 312-353-9317
1) The Delisting Risk Assessment Software (DRAS) program
- To install DRAS 3R1, click on the following link to download a self-extracting zip file (DRASv3R1zip.exe) to your computer.
Delisting Risk Assessment Software (DRAS) version 3.0 (Self-Extracting zip file) (12.7MB) October 2010
- Double-click DRASv3R1zip.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.
- You may encounter error messages during installation (usually that relate to *.dll files); however, most users find that ignoring those errors will still result in a successful installation.
- Once DRAS 3.0 is installed, you may delete or archive the three downloaded files as well as the self-extracting zip file.
2) The Delisting Technical Support Document (DTSD)
Updated October 2008. 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.
You can also read the DTSD as a separate set of documents:
- 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, 1.6MB)
- 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, 4MB)
- Appendix A-1b: Appendix with Chemical Data for Waste Constituents in DRAS (PDF) (147pp, 1MB)
- 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 (PDF) (3pp,42K)
3) The DRAS User's Guide
DRAS Version 3.0 User's Guide (PDF) (21pp, 609K) October 2008
The User's Guide 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. The current version of the DRAS User's Guide had been updated to describe recommended modifications and workarounds to problems reported for the surface impoundment module and the Aggregate Risk and Hazard Quotient Results Table (PDF) (1pg, 52K) September 2010