1 

## User’s Guide Delisting Risk Assessment Software (DRAS)

Version 3.0

October 2008

U.S. EPA Region 5 Chicago, Illinois2 1 Introduc tion................................................................................................................... .1-1

1.1 Objectiv es .................................................................................................................1-1

2 System Requirements a nd Installa tion ......................................................................2-1

3 Quick User’s Guide.......................................................................................................3-1

4 Overview....................................................................................................................... ..4-1

5 Detailed Descr iption .....................................................................................................5-1

5.1 Start- Up.....................................................................................................................5- 1

5.2 Main M enu ................................................................................................................5-1

5.3 Steps 1-3 – Entering Fa cility Inform ation .................................................................5-4

5.4 Steps 4&5 – Selecting Chem icals of C oncern .........................................................5-6

6 Results........................................................................................................................ ....6-11-1 1 Introduction

The U.S. Environmental Protection Agency (EPA) developed this User’s Guide as part of the Hazardous Waste Delisting Program. The Re gion 6 Delisting Program originally developed The Delisting Risk Assessment Software (DRAS) to compute ri sks and hazards associated with individual waste streams for delisting pet itions. Regions 5 and 6 updated DRAS and

released version 3.0 in Oct ober 2008. DRAS is used by several EPA Regions, numerous delisting-authorized states and facilities interested in delisting waste.

DRAS was specifically designed to help determi ne whether a waste me ets the conditions

under Title 40 Code of Federal R egulations 40 CFR §261.11(a)(3) ( Criteria for Listing

Hazardous Waste ), as well as other fact ors. These may include c hemical constituents other

than those for which the wast e was listed that could caus e the waste to be a hazardous waste. This guide will assist the user in applying DRAS to evaluate petitions to delist

hazardous wastes submitted under (40 CFR) §260.22.

DRAS performs a multi-pathway and multi-ch emical risk assessm ent to assess the acceptability of a petitioned wa ste to be disposed into a Subt itle D landfill or surface impoundment. DRAS executes both forward- and back calculatio ns. The forwardcalculation uses chemical concentrations and waste volume inputs to determine cumulative carcinogenic risks and hazard resu lts. The back-calculati on applies waste volume and acceptable risk and hazard values to calculate upper- limit allowable chemical

concentrations in the waste.

1.1 Objectives

The objectives of the User’s Guide are: (1) to provide gene ral information about DRAS; (2) to provide step-by-step instruct ions on using the software and in terpreting the results of the risk assessment; and (3) to troubleshoot difficulties common ly encountered in installation and operation of the software. Th is information is int ended to assist regulatory authorities, petitioners, and decision makers in the hazardous waste de listing determination process.

Users are directed to the De listing Technical Support Docu ment (DTSD) for detailed background information about the algorithms, equations, and th e dilution-attenuation factors (DAFs) used in the risk assessment. The DTSD is provided with the software and in most installations, can be accessed directly fr om within the progra m by selecting the Documents menu. In the event the link fails, the documents are located in the Documents subfolder

within the folder in which th e program was installed.

For additional information nece ssary to satisfy t he information requirements of a complete delisting petition, Petitioners should consult their delisting regulatory authority. The Region 6 RCRA Delisting Program Guidance Manual for the Petitioner (U.S. EPA, 1996) is also

available with additional info rmation for t he petitioner.2-1 2 System Requirements and Installation

This section summarizes the operating syst em requirements for DRAS version 3.0.

• Pentium, or compatible processor-bas ed personal computer (PC with 1GHz or greater is recommended).

• Windows 2000, or Windows XP, or later Windows versions.

• 256 MB of RAM.

• At least 100 MB of available hard disk space.

• Printer for generati ng hard-copy reports.

A CD-ROM drive, flas h drive, or floppy driv e is not necessary but c an facilitate exporting of DRAS project files from one computer to another.

To install DRAS version 3.0, download setup.ex e to your PC, double-click setup.exe, and

follow instructions on the screen.3-1 3 Quick User’s Guide

1. Through Start and Programs , Open DRAS version 3.0.

2. Select New Analysis from among the Analysis Operations also along the left side of

the screen.

3. In the DRAS window Steps 1-3 , enter values into all requir ed fields, choose single- or multi-batch waste generation, enter the annual or total volu me in cubic yards (for landfills), set target risk and hazard according to your delis ting regulatory authority.

Click Update , then To Steps 4&5

.

4. In the DRAS window Steps 4&5 , use drop-down tabl es to add DRAS waste constituents to the projec t list and enter analytical dat a for total and leachate

concentrations. Click Update Site COCs , then Run DRAS

.

5. Check the Pathways Exceeding the Delisting Limits output table for any concentrations exceeding target risk, hazard, or SDWA MCLs.

6. Check the Maximum Allowable TCLP Concent rations – Groundwater Exposure Pathway and Maximum Allowable Total Concentrations – Surface Exposure Pathway output tables for a llowable concentrations.

7. Check the Aggregate Risk and Hazard Quotient Results output table for aggregate

risks or hazards that ma y exceed target levels.

8. Check the Toxicity Characteri stic, Soil Saturation, and Ecological Values output table

to confirm that none of thes e parameters are exceeded.

9. Click Save Analysis and Print output tables as needed.4-1 4 Overview

DRAS assesses the carcinogenic risk and non carcinogenic hazard associated with a petitioned waste’s disposal to either of two types of waste managemen t units (WMU). These are a landfill and a surface impound ment. The software prompts the user to enter waste

information which should be available from a facilit y’s delisting petition. Once all the general

waste information and the chem ical specific concentration dat a are entered, the program performs screening and cu mulative risk and ha zard calculations.

The screening risk evaluation provides the user with Toxicity Characteristic Leachate Procedure (TCLP) and total wast e constituent concentrations associated with the target carcinogenic risk level and the target hazard quotient for the most sensitive exposure pathway. The target carci nogenic risk and noncarcinogenic haza rd must be entered by the user. The targets are typically set by the delisting regul atory authority applicable to your delisting and may vary from one jurisdiction to another due to differenc es in local risk management objectives. TCLP an d total constituent concentrations derived from target risk and hazard settings may be used as the maximum allowable waste constituent concentrations for a multi-year standard exclusion (delisting) . If the waste constituent concentration exceeds these risk-based levels, the waste may not qua lify for a multi-year

exclusion under 40 CFR §§260.20 and 260.22.

The cumulative risk assessment provides th e user with an overall carcinogenic risk and noncarcinogenic hazard index (HI) for the pe titioned waste as a whole, summing risks associated with each exposure pat hway for a given constituent and then summing risks for

all waste constituents. The assessment also provides t he user with the cumulative carcinogenic and noncarcinogenic risks associated with a specific waste cons tituent. If the

waste constituent concentrations exceed the risk-based levels calculated from DRAS, the waste may not qualify for exclusion under 40 CFR §§260.20 and 260.22. The methods and

data used in the determination of media waste concentrations at the point of exposure and the risk assessment algorithms are out lined and referenced in the DTSD.

The results are presented in a series of tabl es documenting the constituents evaluated, any

modifications to def ault chemical, physical, or toxicologica l parameters, forwar d estimation of risks by pathway and constituent, back-calculated estimation of allowable concentrations by pathway and constituent, estimates of aggr egate risk and hazard, and a screening of concentrations exceeding the allowable concentrati ons, soil saturation, toxi city characteristic concentrations, or ecological screening values.

The user may also enter the detection limit (DL) value associated with a given waste constituent and the program will determine the risk and hazard associated with a fraction of

the waste constituent DL value. The default fraction used in the risk assessment is one-half

of the detection level. The program tracks waste constituen t risks associated with actual

measured concentrations with and without out non-det ects valuated at one-half of the DL.5-1 5 Detailed Description

5.1 Start-Up

Upon opening DRAS 3.0, a small window box a ppears with a reminder t hat a number of changes have been made to the program. A link is provided to a more detailed summary of

the modifications. Click No, go to program to bypass the message and open the main

menu.

5.2 Main Menu

The Main Menu appears as follows:

Existing projects are listed in a windo w on the left side of the screen labeled Available Analyses . To start a new project, select New Analysis from among the Analysis Operations also along the left side of the scre en. You can also click on the Begin a New Analysis button located in the tool bar or by selecting New Analysis from the File Menu at the top of the page. This will open a window w here you can enter facility info rmation (see section 5.3). Note that project data entry and results scr eens will appear in the empty window to the right5-2 within the Main Menu and the commands listed both above and to the le ft of the project window will remain during all subsequent DRAS operations.

The other options available under Analysis Operations are:

Open Analysis – This will open any project listed above. The user must have that project

selected in the Available Analyses window by clicking on it once until highlighted.

Save Analysis – This will save the project. Note: this option is only availabl e if a project is open. Also, the projects are automatically saved within th e DRAS database. In order to archive a project or move it to another computer you must use the Export Analysis

command.

Close Analysis – This will close the project. Note: this option is only available if a project is

open.

Export Analysis – This will export the project as a f ile in a format spec ific to the DRAS software (with the extension .drs ). Note: this option is only ava ilable if a projec t is open or is

selected in the Available Analyses window by clicking on it once until highlighted.

Copy Analysis – This will create a duplicate copy of a pr oject. You can run variations of the same project without having to reenter data by copying the analysis and renaming it and saving it in the Steps 1-3 window (see Section 5.3.).

Import Analysis – This will allow you to import a pr oject from an archive or another computer by opening an existing DRAS format ted “Export” file (with the extension *.drs ).

Delete Analysis – This will delete the project file.

Update Analysis – This function is used to update existing projects in the event a newer version of DRAS is issued. A duplicate of all projects im ported into the Available Analyses window will be created using physical and chemical parameters from the new version. The

user should rename them or otherwise note they may have di fferent results. This function will not update DRAS version 1.0 a nd 2.0 files since the vers ion 3.0 database has been

restructured.

Delisting Technical Support Document (DTSD)

A link to the Delisting Technical Support Docum ents is provided down the left side of the

screen below the Analysis Operations . Clicking on these will open the documents in portable document format in the project window to the righ t. The same documents are also

available under the Documents sub-menu at the to p of the page. In th e event the links fail, which can happen depending how your portable docum ent format viewer is installed, you

can access these files from the Documents sub folder located in the folder in which you

installed the DRAS.5-3 Tool Bar and Menu

A number of these same commands repeat as buttons in the tool bar or as menu options at the top of the page. Additional commands available in the tool bar and menu include:

Print – This allows the selection of various repo rts and results tables fo r hard-copy printing. Note: many of the t ables are wide and print better in landscape mode.

Export to Table – This allows whichever t able is displayed in the pr oject box to exported as

either a Table Export in *.html format or a comma and space de limited text file suitable for importing into a spreadsheet pr ogram such as Microsoft Exce lTM. The export to the comma delimited export is very useful in the event you wish to sort, compare, or process the results in ways beyond those available within DRAS.

Edit Customer COCs and DAFs – This allows the creati on of and management of a

database of chemicals or elemen ts not preloaded in DRAS (See Section 5.4). Table entries can be made for the same ph ysical, chemical, biological, and toxicological parameters

entered for the DRAS default elem ents and chemicals. Dilution- Attenuation Factors (DAFs), a parameter relating leachate co ncentrations in the landfill or surface impoundment to groundwater concentrations at a nearby residential suppl y well, can be entered on a separate line. DRAS can only ev aluate one constant DAF for a constituent entered in the

customer database. This DAF will be used for a ll entered concentrations. To avoid run-time errors, please enter estima ted DAFs for both landfill and surface impoundments for each unique constituent added. Note : this function is not operationa l in all installations at this

time. In the event this func tion does not work on your computer, try installing DRAS on a different computer or choose a surrogate element or chemical (one you were not planning on including in your analysis) and modifyi ng the physical, chemical, biological, and toxicological parameters in the table in DRAS window Steps 4 & 5 while noting your change.

Analysis – This option lets you switch views be tween facility informati on, chemical data entry, and results screens. Note: the links to the Chemical Properties Database and the Show Delisting Level Analysis are not operational at this time. Show Delisting Level Analysis is meant to allow t he calculation of delisting levels us ing only facility and target risk information for the purposes of co nveying target data quality ob jectives at the outset of a project. EPA will attempt to rest ore these functions in the futu re. All chemic al properties

entered in the default database can be viewed in DRAS window Steps 4 & 5 once that

element or chemical has been added to the project-specific list. All of these values can also be viewed along with references in Appendix A1 of the DTSD. Target data quality concentrations must be generated by selecting a ll of the elements and chemicals of concern and running DRAS to obtain maximum allow able total and TCLP concentrations.

Window - This option lets you switch views be tween facility informati on, chemical data entry, and results screens but incl udes links to more of the indivi dual results scr eens. Note:

the link to the Chemical Properties Database is not operational at this time. All chemical properties entered in the default da tabase can be viewed in DRAS window Steps 4 & 5 once5- 4 that element or chemical has been added to the project-sp ecific list. All of these values can also be viewed along with references in Appendix A1 of the DTSD.

DRAS v.3.1 Help – This command is reserved for a hel p, topics, index, and search-style help function which is not currently operational. Please refer to this gu ide, the DTSD, or the Agency’s contact for DRAS for assistance. Th e current Agency contact for DRAS is Todd Ramaly, EPA Region 5, and can be reached at 312-353-9317 or ramaly.todd@epa.gov

.

5.3 Steps 1-3 – Entering Facility Information

The following screenshot shows th e first data entry window. Step 1 includes fields for entering the project filename, petitioner, location, EPA Region, waste code, waste description, and pertinent date s. There is also a User Comment box where detailed

comments about the run can be entered. This is helpful if the user wishes to run the project multiple times with varying inputs and differentiate one ru n from another.

Step 2 – Waste Management Unit and Risk/HQ Information – is where the us er specifies the following input:

Waste Management Unit Type - Landfill for non-liquid wastes or Surface Impoundment for liquid wastes;

Waste Volume – This is the value for waste g enerated annually for continually generated

wastes or one total volume for one-time projects like remediation. For la ndfills, please enter the annual volume in cubic yards. For surfac e impoundments, please ent er the total volume of liquid in the surface impoundment in c ubic meters (typical operating capacity).

Flow Rate of Liquid – This applies to evaluations of surface impoundments only and must be set to the expected fl owrate of liquid into the surfac e impoundment in c ubic meters per

year.

Waste Management Unit Active Life – The default values are 20 years for landfills and 50 years for surfac e impoundments.

Target risk and target hazard quotient – The target risks and hazards are obtained from your delisting regul atory authority.5-5 This Step also allows you to choose between a One Year Batch delisting, typical for a

remediation waste scenario or a Multiple Year Batch where the facility plans on generating the waste indefinitely.

On some systems, you may not be able to see the entir e screen, including important

commands at the bottom of the window. By selecting the Windows button that allows multiple window pane display (between the “min imize” button and the “close” “x” button on the menu bar above) the Steps 1-3 window refreshes with a scroll bar on the right. Use the

scroll bar to move to the bottom of the window wher e you can now choose from the Step 3 options. The following screen shows the bottom of the Steps 1-3 window.

Step 3 – The following four co mmands are presented under Step 3 – Update Information :

Update Information – This locks in all entries or modifications made in steps 1 & 2.

Cancel Changes – This clears all modifi cations to steps 1 & 2.

Calculate Delisting Levels – This feature generates a c oncise list of maximum allowable

concentrations for both total c oncentrations and leachate concent rations so that “practical quantitation limits” (PQLs – the concentrations at whic h selected laboratory methods are

sensitive to the tested consti tuents) could be confirmed as adequate for comparison to the5- 6 DRAS maximum allowable concentrations. This feature is not currently working as

intended . EPA recommends that wast e constituents be entered in steps 4&5 and that the DRAS analysis be fully run to gene rate maximum allowable concentrations. The existing DRAS project named example.drs can be used to prepare provis ional delisting levels for use as PQLs. The project example.drs has all chemicals in the DRAS database already selected so the user need only reenter the faci lity name, annual volume, and target risk and target hazard in order to qui ckly run the project. “Dummy ” values for TCLP and total concentrations are also pre-loaded into example.drs . Even though the concentrations are not needed in determining maximum allowable delisting levels (for use as PQLs in this case)

DRAS will not run without c oncentrations entered. Example.drs can be renamed to match your project.

To Steps 4&5 – This option moves data entry to the Steps 4&5 window where individual

waste constituents are select ed and concentrations are ente red. Note: This command will

not be available unless all m andatory fields, marked with a re d asterisk, are completed.

5.4 Steps 4&5 – Selecting Chemicals of Concern

Step 4 includes a table where indivi dual waste constituents are se lected for eval uation. By clicking in the Chemical Name or CAS Number fields, a drop-down table can be opened revealing all of the chemicals or elements available in the DRAS default database arranged in alphabetical order. Waste c onstituents are added to the projec t-specific Step 4 table by scrolling down and clicking on a particular consti tuent. The user can also begin typing a

constituent name or CAS number and if a default constituent ma tches the entry, the dropdown table will advance to th e matching constituent.

Once added to the project-specific analysis tabl e, the user must ente r a concentration or detection level (in the case of non-detects) for both the total concentration and the leachate

concentration. Leachate conc entrations are typically obt ained from the Toxicity Characteristic Leachate Procedure (TCLP) although other tests may apply depending upon the delisting regulatory authority’s requirements. A non-zero concentrat ion must be entered for both types. If you wish to run the analysis with incomplete data, for example to see if a waste will pass based on existing data, EPA recomm ends that you enter a dummy value so that the program will run. The dummy value can be an extremely low detection level so that

the estimated risk or haza rd doesn’t skew the results.

To record a non-detected result, enter the detecti on limit and select the “d etection limit” box. Risks will be aggregated in two ways. One in cludes risks generated only from detected

concentrations and another includes risks generated from both detected concentrations and a fraction (50%) of the detection limi ts from non-detected constituents.5-7 Modifying physical, chemical, biological, and toxicological parameter s: To modify any parameter (for example, to incorporate an updat ed cancer slope factor), the user can scroll

across the line for a constituent by using the left and right cursor keys and typing in the new value. Any modifications to the default database will be docum ented in a particular output

table.

Evaluating waste constituents not available in the default dat abase: In the event that the

user wishes to evaluate a wast e constituent that is not among those pre-loaded in the DRAS database, there are two ways to perform this evaluation.

First, a customer-generated sepa rate database for uni que chemical entries can be prepared by the user. The menu item Edit Customer COCs and DAFs from the Edit menu. Table

entries can be made for all of the same physical, chemical, biological, and toxicological parameters entered for the DRAS default elements and ch emicals. DAFs, a parameter relating leachate concentrations in the l andfill or surface impoundm ent to groundwater concentrations at a nearby resi dential supply well, can be ent ered on a separate line. The DRAS can only evaluate one constant DAF for a constituent entered in the customer

database. This DAF will be used for all entered concentrations. To av oid run-time errors, please enter estimated DAFs for both landfill and surface impoundments for each unique

constituent added.5-8 Instructions for adding a new COC:

1. From the Main Screen, Click on Customer COCs and DAF under the Edit menu. This should bring up the Customer COC and DAF Screen (Fig 1).

 Figure 1

2. COC properties are entered in the top half of this window and DAF information is

entered in the bottom half.5-9 3. Click on the Chemical Name cell in the top window and enter the first COC: for example - HGLTEMP1 (Figure 2). After entering the Chemical Name, Click on the cell to the right (below C AS). The screen display would now be similar to Fig 2.

 Figure 25-10 4. Enter the values for CAS ID and other properties. On ce all values have been entered, click on the row below (Colored in blue). This should update the COC properties. Once the dat abase is updated, the pencil ic on will change to a black

arrow.5-11 5. Now, click on the DAF window in the lower-half and enter CAS Number and respective DAFs. After entering all the data, click on the blue row below to update the

database. Once the databas e is updated, the pencil ic on will change to a black

arrow.5-12 6. To access this COC from the Site CO Cs screen, click on t he drop down at the

bottom and select the Customer option. Now, HGLTEMP1 can be added to the project database.

Note : The Customer Database function is not operation al in all installations at this time. If it does not work on your insta llation, please try installing DR AS on a different system or use the second approach to evaluati ng a non-default waste constituent as described in the next paragraph.

A waste constituent not alr eady included in the default DRAS database can also be added by selecting a DRAS constituent the user spec ifically does not need for the project to serve as a surrogate for analysis. Scroll to the right to enter all the physical, chemical, biological, and toxicological parameters to match the new chemical or element. Choose an organic chemical, or one for which the DAFs are not “TCLP dependent” for the su rrogate. The user must keep a separate record docum enting that the chemical select ed is actually a surrogate

for another.

The remaining commands under Step 5 – Update Chemicals of Concern and Run DRAS

are:

Cancel Changes – This will remove any modificati ons made since the last update.5-13 Update Site COCs – This will save all changes and enter ed data in Step 4. Users should update periodically while adding many waste consti tuents in order to mi nimize the loss of data if the program unexpectedly quits.

Delete COC – This will delete a selected waste consti tuent only if the line corresponding to it is highlighted by clicking on the box to the left of the Chemical Name.

Back to Steps 1-3 – This will return the user to Steps 1-3, Delisting Petitioner Information, Waste Management Unit and Risk/HQ In formation, and U pdate Information.

Run DRAS – This will run the DRAS analysis, providi ng both a forward esti mate of risk and

hazard based on the concentrations of waste constituents ent ered and a list of maximum

allowable concentrations back-calculated fr om the target risk and hazard settings6-1 6 Results

The following tables will open upon a successful DR AS run with each available for viewing, printing, or export: To return to Steps 1-3 or Steps 4&5 from the results screens

, click Close

Results Screens under the Windows menu at the top of the page.

List of Customer COCs – This is a list of all customer COCs selected for analysis including all physical, chemical, biological, and toxicological data entered.

List of COCs with Altered Chemical Properties – This is a list of all default DRAS COCs selected for analysis where the us er has altered any of the physical, chemical, biological, and toxicological data. This table will identify ea ch parameter, units, t he original value, and

the new value.

Limiting Pathways – This table summarizes the most s ensitive pathway for each constituent for both ground water pathways (evaluated as leachate) and surface pathways (evaluated as total concentrations).

Groundwater Pathway Hazard Quotient – This displays the esti mated hazard quotient via ground water for each waste constituent by pathway and summed by constituent and pathway.

Groundwater Pathway Risk – This displays the estimated excess cancer risk via ground water posed by each waste constituent and summed by consti tuent and pathway.

Maximum Allowable TCLP Concentrati on – Groundwater Exposure Pathway – This table displays the maximum allowable receptor c oncentration for a num ber of ground water exposure pathways based on targ et risk and hazard settings. The minimum value of these concentrations and the Safe Drinking Water Act MCL is converted into a maximum

allowable waste leachate concentrat ion based on the DAFs that apply.

Surface Pathway Hazard Quotient – This displays the estimate d hazard quotient via surface pathways for each waste constituent by pathw ay and summed by consti tuent and pathway.

Surface Pathway Risk – This displays the estimated excess cancer risk via surface pathways posed by each waste constituent and summed by cons tituent and pathway.

Maximum Allowable Total Concentra tions – Surface Exposure Pathway – This table displays the maximum allowable total concentr ation for a number of surface exposure pathways based on the target risk and hazard settings. The least of these concentrations is

selected as the overall maxi mum allowable concentration.

Aggregate Risk and Hazard Quotient Results – All excess carcinogen ic risks for both detected values only and a combination of detected values and a fr action (50%) of the

detection level for non-detected constituents are aggregated here. All hazard quotients for6-2 both detected values only and a combination of detected values and a fr action (50%) of the

detection level for non-detected co nstituents are aggregated here in to a hazard inde x. Note: If the hazard index exceeds the target hazard set by the delisting regu latory authority, EPA

recommends that the constit uents may be evaluated and split by target organ (see DTSD Appendix A-4) before drawing a conclusi on about exceeding the target hazard.

Toxicity Characteri stic, Soil Saturation, and Ecological Values – This table identifies waste

concentrations that exceed toxici ty characteristic concentrations , waste concentrations that exceed soil saturation values (a condition that cannot be eval uated properly by the fate and transport models used in DRAS), and waste concentrations that result in surface water concentrations (from uncontro lled run-off at t he waste management unit) that exceed surface water quality criteria.

Pathways Exceeding the Delisting Limits – This is a concise summary of only those

evaluated constituents that exceed the maximum allowable concentrations based on target

risk and hazard settings.