Bernice To Mitch Cron/R3/USEPA/US(S)EPA Pasquini/R3/USEPA/US

cc Mindi Snoparsky/R3/USEP/VUS@EPA, Jeffrey 02/25/2009 01:58 PM Tuttle/R3/USEP/VUS(a)EPA

boo Subject Soil Screening & Remediation Goals (SSRG) Tool results for

Central Chemical

Mitch,

As you requested, I'm forwarding as an attachment to this email the SSRG Tool inputs and results for the Central Chemical Administrative Record. I used the most conservative input values into the model (e.g. longest chemical half lives). As I've stated to you in meetings, this tool is not applicable for soil with known or observed non aqueous phase liquid (NAPL) contamination.

This SSRG tool calculates soil screening (SSLs) and remediation goals for three different conceptual site model (csm) soil contamination scenarios. The first scenario represents a spill of contamination where the source is in the uppermost soil layer. The second scenario is where there is evidence that soil contamination has moved to the middle ofthe soil column. The third scenario is where contamination is at the top of the water table or bedrock.

At this site, the third scenario is representative of site conditions because the soil contamination is found to top of bedrock at several locations. Therefore, the third scenario SSRG results would be applicable as Preliminary Remediation Goals (PRGs) for soils with the objective of being protective of ground water. A note of caution, however, the majority of pesticides have extremely elevated SSRG concentrations (specifically the DDTs, DDEs, DDDs, Aldrin, Alpha Chlordane, Chlordane [technical grade], Endrin, Ketone, gamma chlordane, Heptachlor, Heptachlor epoxide, and Toxaphene). In fact, most of the SSRG , results for these chemicals are approaching 100% concentration or in some instances greater than 100%. This is due to the extremely large literature Koc values (i.e. these chemicals are hydrophobic and take a long time to move through the soil column). Their literature value half lives are short in comparison to the time it would take for these contaminants to move through the soil column.

Because these SSRG estimated numbers are too high, and likely not conservative enough to be protective of groundwater if used as the PRG concentrations for soil cleanup, I recommend using these SSRGs for the above compounds only for comparison to the other PRGs developed for the other risk receptors (i.e.human health and ecological), and use the lowest PRG for each contaminant as the soil cleanup value for the entire site. As long as the PRGs are below the SSRG concentrations for the above identified chemicals (i.e. DDTs, DDEs, DDDs, Aldrin, Alpha Chlordane, Chlordane (technical grade), Endrin, Ketone, gamma chlordane, Heptachlor, Heptachlor epoxide, and Toxaphene), then the site soil cleanup numbers for these chemicals may prevent groundwater degradation from contaminated soils. If, however, the PRG turns out to be the SSRG for any of the above compounds, a sensitivity analysis for the half life should be performed to further evaluate the SSRG result including a more thorough effort to collect half life literature values for these chemicals. For the remainder of the chemicals (2,4-D, Alpha HCH, Atrazine, Beta BHC, Dieldrin, Diphenamid, Endrin, gamma BHC, Naphthalene) evaluated with the SSRG tool, the remediation goals are lower in concentration and can be used as the PRG as they are more likely to be protective of groundwater contamination.

I've also attached the Users Guide for the Tool. If you have any questions concerning this information, feel free to stop by my office.

I'^ail

Central Chemical SSRG Tool, Ver 2.0 (March, 2008)March 28.xls

AR304366

SSRG.pdf

"The future belongs to those who believe in the beauty of their dreams."

Eleanor Roosevelt

Bernice Pasquini USEPA 1650 Arch Street Philadelphia, PA 19103 email: pasquini.bernice@epa.gov telephone: 215.814.3326 fax: 215.814.3015

AR304367

SOIL NING& REMEDIATION

OAL Too Version 2.0

January,2009

USER'S GUIDE &

TUTORIAL

by David M. Kargbo, PhD

USEPA Region 3 Philadelphia, PA

.-^-^^"'''^

3 \ \ - - / ,

AR304368

DISCLAIMER

The Soil Screening & Remediation Goals (SSRG) Tool software, Version 2.0, and this User's Guide & Tutorial (herein collectively referred to as "SSRG Tool") have been subjected to USEPA's.peer and administrative review and have been approved for publication as a USEPA document. However, the SSRG Tool is made available on an as-ix basis without guarantee or warranty of any kind, express of implied. Neither the United States Government (including the USEPA), nor the author or reviewers accept any liability resulting from the use ofthe SSRG Tool. In addition, any interpretation ofthe predictions ofthe SSRG Tool is the sole responsibility ofthe user. Mention of trade names or commercial products does not constitute endorsement or recorhmendation for use.

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ACKNOWLEDGEMENT

The SSRG Tool was reviewed by a distinguished group of technical expeils. The author wishes to acknowledge the USEPA Region III Technical Support Staff for their comments and suggestions with special thanks to Ms. Bernice Pasquini, Ms. Nancy Rios, Mr. Bruce Rundell, Ms. Mindi Snoparsky, Ms. Linda Watson, and Ms. Jennifer Hubbard. A thorough review was also performed by Mr. Rob Earle and Dr. Noman Ahsanuzzaman of Shaw Environmental, a contractor to the U.S. EPA Ground Water Technical Support Center (GWTSC) and the Center for Subsurface Modeling Support (CSMoS) in Ada, OK with special thanks to Dr..David Burden, GWTSC Director, for coordinating the review process. Finally, special thanks go to the author's Fate of Pollutaiits graduate class members (spring 2008) at Temple University's College of Engineering. These students utilized the SSRG Tool software for extensive project exercises and in the process, contributed significantly in improving the quality ofthe software.

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Con ten t s

1.0 What's New in the SSRG Tool, Version 2.0 Software? 8

2.0 SSRG Tool Basics 8

3.0 SSRG Tool Modules ?. 10

3.1 Pore Water Velocity (PWV) Module : 10

3.2 Model Equations for the PWV Module.... 12

3.3 DAF/MZ Module ....; 13

3.4 Model Equations for the MZ/DAF Module 14

3.5 Results Module .....! : 15

3.6 Model Equations for the Results Module 17

5.0 , SSRG Tutorial 2;0

5.1 The Problem '. 20

5.2 Data Requirements for SSRG Tool 20

5.3 SSL and SSRG Modeling Steps.. 21

AR304371

Figures

Fig. 1: Vadose Zone Parameters Entry Forms 10

Fig. 2: Schematic representation of contamination scenarios in SSRG modeling tool 11

Fig. 3A: Site specific data entry for scenario 2 '. 12

Fig. 3B: Default parameters as a function ofthe selected layer soil type 12

Fig. 4: Groundwater parameters .' 14

Fig. T-1: Excel security warning 21

Fig. T-2: Vadose Zone Parameters Entry Forms 22

Fig. T-3: Schematic of SCENARIO 1 contamination with only the source layer contaminated . 23

Fig. T-4: Data entry for Scenario 1 23

Fig. T-5: Schematic of SCENARIO 2 contamination with the surface layer and the layer beneath the surface layer representing the Source layer 24

Fig. T-6: Data entry for Scenario 2 ....'• 24

Fig. T-7: Schematic of SCENARIO 3 contamination with surface layer and the layers beneath the surface layer (except the layer above the groundwater) representing the Source layer 25

Fig. T-8: Data entry for Scenario 3 ; 25,

Fig. T-9: Additional soil data entry ; 25

Fig. T-10: Groundwater Parameters Entry Forms :.. 26

Fig. T-l I: Chemical Parameters Entry Form 27

Fig. T-l 2: Scenarios 1-3 vadose zone parameters and calculated pore water velocities 28

Fig. T-I3: A clear entry screen following the clicking ofthe "Clear & Select oil Type" button. 29

Fig. T-l4: Data cells filled with default parameters, calculated Vs based on default parameters.29

AR304372

Tables

Table 1: SSL and SSRG results for organic chemicals 16

Table 2: Summary Interpretation of Results - SSL versus SSRG... 17

Table 3: Summary Interpretation of Results - Required action (or inaction) based on site contamination levels of each chemical (in parenthesis) and SSL & SSRG? 17

Table T-l: SSL and SSRG results for organic chemicals 31

AR304373

Acronyms and Symbols

Acronyms DAF: Dilution Attenuation Factor MCL: Maximum contaminant level MZ: Mixing Zone PWV: Pore Water Velocity Module RBC: Risk Based Concentrations RGOs: • Remedial Goal Objectives SSRG: Soil Screening & Remediation Goals SSL: Soil Screening Level TAL: Target Analyte List TCL: Target Compound List USEPA: U.S. Environmental Protection Agency

Symbols b: d C,

Cgw: da:

toe: Cw

H': i: I K: Kd: Ks: -

Koc: L: Lv ne: nt: R: S: VA: I mean:

Vs:

Pb PP

Ks exponential parameter (unitless) Mixing zone depth (m)

Total soil concentration (mg/Kg) Concentration in groundwater at hypothetical well at edge of source area (|ag/L) Aquifer thickness (m) Fraction ofsoil organic carbon (unitless) Maximum allowable concentration in groundwater (ug/L) Henry's Law Constant (unitless) Horizontal hydraulic gradient (m/m) Vertical infiltration rate through vadose zone (m/yr) Saturated horizontal hydraulic conductivity (m/yr) Distribution Coefficient (L/Kg) Vertical hydraulic conductivity (m/yr) Organic carbon partition coefficient (L/Kg) Source length parallel to groundwater flow (m) Distance from the bottom of source layer to the water table (m) Effective porosity (unitless) Total porosity (unitless) Retardation coefficient (unitless) Aqueous solubility limit (mg/L) Degradation half-life (yr) Mean travel time to the top ofthe aquifer (yr) Vertical pore water velocity through the specified soil layer (m/yr) Bulk density (kg/L) Particle density (kg/L) Volumetric moisture content (Vwaier/Vtoiai) Effective moisture content (Vwaier/Viotai) Source Zone air-f i l led soil porosity (Va/rA'tooi)

AR304374

1.0 W h a t ' s New in the S S R G Tool , Version 2.0 Sof tware?

The Soil Screening & Remediation Goals (SSRG) Tool and its User's Guide and'Tutorial are collectively referred to as the "SSRG Tool". The SSRG Tool Version 2.0 is a significant improvement over previous versions ofthe SSRG Tool (Kargbo, 2006).Improvements include:

i. The ability for users to enter their own data, ii. Users can now toggle between the default database in the program or use their own

data on: vadose zone parameters; and chemical parameters, iii. Customized printing is available on a single click for: a) vadose zone parameters; b)

groundwater parameters; c) organic chemical parameters; d) inorganic chemical parameters; and e) soil screiening levels (SSLs) and/or SSRG results for all chemicals of interest,

iv. Decision on whether further action is warranted based on a comparison of measured soil concentration and SSL and/or SSRG

2.0 S S R G Tool Basics

This User's Guide is developed to verify calculations performed by the SSRG Tool, Version 2.0, an executable MS Excel© workbook. It is a one-dimensional, steady-state, vadose zone contaminant fate and transport model. The model was designed to meet several objectives:

i. Calculate site-specific soil screening levels (SSLs) and/or remedialgoal objectives (RGOs). -

ii. Provide a user friendly tool that enables the user to either select from reasonable literature input parameters based on site soil types or directly input site specific parameters,

iii. Provide more realistic estimates of contaminant migration to groundwater and -resulting environmental risks posed by such migration,

iv. Enable a user to select modeling scenario that may be similar to his/her site conditions,

v. Utilize the SSRG tool as a detailed waste-unit specific model for contaminant fate and transport analysis,

vi. Perform vadose zone contaminant fate and transport analysis in a manner that is consistent with the contaminant migration protocol ofthe USEPA Soil Screening Guidance (USEPA 1996) and its supplement (USEPA 2001).

vii. Evaluate the effectiveness of remedial alternatives by allowing the user to modify key input parameters (e.g., infiltration rates, hydraulic parameters, etc) that influence contaminant transport time and concentration.

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The model estimates:

i. The mean travel time in the vadose zone for any analyte on the Region III RBC table, the USEPA target analyte list (TAL), and the USEPA target compound list (TCL) to arrive at the base of the vadose zone;

ii. The maximum groundwater concentration at a receptor location on the edge ofthe waste unit; and

iii. The maximum contaminant concentrations in soil that will not exceed the maximum contarhinant level (i.e.. Tap Water jevel in the RBC table) in groundwater using either the SSL approach and/or the SSRG approach.

The model would require only minimal data input with common, easily measured geotechnical parameters. For example, SSRG tool successfully avoids solving complex equations such as the Richards, Phillips, or Green-Ampt infiltration equations, and avoids requiring exotic or esoteric experimental input parameters such as bubble pressure, disconnectedness index, suction front head, saturated suction, Green-Ampt wetting front suction, or sorptivity. This is based partly on the author's many years of teaching and researching the subject matter and incorporating computational expediencies into the program code. The result is a robust analytical tool that incorporates vadose zone processes for the purpose of screening sites and providing reasonable SSRGs.

2.1 Model Assumptions:

There are several assumptions worth noting. These include:

i. Dispersion is not incorporated into the vadose zone transport estimate, only equilibrium partitioning,

ii. Dispersive mixing is assumed in the saturated zone (similar to the current SSL guidance),

iii. Transport time in the vadose zone is determined by Darcy's Law and represents mean flow,

iv. To simplify leaching estimates, a homogeneously distributed source of contaminants is conservatively assumed in the source layer.

V. Reversible linear soil-water distribution of contaminants at equilibrium is represented in the source zone by the distribution coefficient (Kd) and Henry's Law Constant (H'), which is calculated according to USEP'A soil screening guidance (USEPA 1996; USEPA 2001) for organic contaminants and a value for mercury,

vi. The organic compound distribution coefficients used in the model are estimated from the organic carbon partition coefficient (Koc) described by USEPA (USEPA 1996; USEPA 2001).

vii. Vadose zone soil organic carbon fraction (foe) is different from groundwater organic carbon fraction,

viii. The sources of the default Koc (and other chemical specific parameter) values used in the calculations include Region III RBC table and other USEPA documents,

ix. First order decay of organic analytes is incorporated into the calculations utilizing .^ published environmental half-lives for biological reactions.

AR304376

3.0 SSRG Tool Modules

The SSRG Tool is a combination of independent analytical modules (PWV; DAF/MZ; Results) whose outputs are linked to logic arguments and numerical outputs of all the other modules. These modules are summarized below.

3.1 Pore Water Velocity (PWV) Module r

The pore water velocity module (PWV) calculates, soil moisture content, effective moisture content, vertical pore-water velocity, and travel times in the vadose zone under the contaminant source and through a multi-layer soil column (Fig. 1).

Data etUty for Scenario 1

Uodsled lave- •

5oiirc» Layer

L iven

Ljyer:

Laytr 3

Ijyer 4

Enier Vental

thckress .Scii TvM

Ussd

VertcilH^d.

Ks(lT.V(

'

&(Conentfal Pflrane:er, b

Tctalpoios!.' • rt if(a::]:onJ

EHective pcfovrv

ne ((.•atiicn)

Moisture conlert '

a*ifraction:

,

Elffclire moi;lu-e cornenl

Qe iltalicn)

Data entry for Scenario 2

Modeled lave-

Source La/e i

U y e r 1

Enter Vertcal

thckress Sal Tvoe

Used

Vertca! H^d cot>J ExponeiiMl

Parane:ef,ij Tctal porostv nl (fiaclion)

EJective porosirv

ne ittacticn)

Moisture • . content 3'A IfractBn!'

Effective moistu'e content

Qe ilia:ticn;

1 1 1 1 1 1

1 I I 1 I I Uy«: l 1 1 1 1 1 1 1

. Data entry for Scenario 3

' Uodslcd lays-

Souro Layer

EntBr Vertcal

thckr«5 Soil Tvpa

Used

Vertcal Hyd cond E<pi;nentiEl

PsrJimeter. b Totjl 30rOSlt ,' ni ifractoni

. El eckve porosity

ne fiactioi) 'o^cture conienl Q* (fradjonl

EBGC:IV€

miDtsture content Qe (fraiticnj

1 I I I 1 1 >

L m n l 1 1 1 1 1 1 1

Aijditional soil data entry liifiilrQlion

rjto (m/yr;. '

Bulk

dcnctY(kq/L)

Poiticie

cloroity ;kq/L)

.^roc. oiq carton

(unitfCG:;)

Fig. 1: Vadose Zone Parameters Entry Forms

The user-defined hydrogeological characteristics for the PWV module include:

i. Infiltration rate (1), ii. Bulk density (Pb),

iii. Particle density (Pp), iv. Layer thickness, and V. Layer soil type.

10

AR304377

Hydrogeological parameters that are functions ofthe selected soil type are automatically displayed when the soil type is selected. These include:

i. Vertical hydraulic conductivity (Ks), ii. . Ks exponential parameter (b),

iii. Total porosity (m), and iv. Effective porosity (ne).

The code in the PWV module then uses the above parameters to calculate: the moisture content (9w); the effective moisture content (6e), and the vertical pore water velocity (Vs) through the specific soil layer.

One ofthe strengths ofthe SSRG Tool software is the ability for the user to select one or multiple scenarios that may apply to the user's site. Like in previous versions, the current version allows users to choose one of three scenarios depending on the nature of contamination under the source. In Scenario 1, only the source layer is contaminated. In Scenario 2, some of the layers (but not all) under the source are known to be contaminated. Scenario 3 is similar to the thought process in the current SSLs guidance. Here the source is directly over the aquifer.

Scenario 1 Scenario 2 Scenario 3

Ml A' r.J. . . , , ' % v * t ' ^ " ' ^ j

Fig 2: Schematic representation of contamination scenarios in SSRG modeling tool

Hydrogeologic parameter data entry is a unique feature ofthe SSRG model. The user has the option of entering his/her own site specific data (Fig. 3A) in USER-INPUT worksheet or use SSRG's default hydrogeological characteristics (Ks, b, nt, and ne) in SCEN-INPUT worksheet. These default parameters are functions ofthe selected soil type and are automatically displayed with the calculated vadose zone parameters (9w, 9e,Vs) when the soil type is selected (Fig. 3B).

11

AR304378

Data entry for Scenario 2

.Vodi tsd l.^viir

Source Ltyer

Layer 1

Verr.,:-3i

ll«c>r*ss

[10

O.rj

06 0.}

&il Vr,<:

l.'frt

Vi.rhi.ilft.J

and

Ksim*,-;

Ext<'nen;o*

P^iiarnKft, b

Tool iOr-a-ily

ni llraclioiii

pwosir,'

ne ilriKlToni

LLir^lure

ranlen!

0 * Ifrsclinnl

r-ifecth-e mcirslure • CORIsffl

Qfi ffrattrjni

SarvJ biXJO i.2 0.44 0.405 . 0.18(1 0.155

. $arvh Loair. 790 ^ 0.46 0.402 0.233 0.210

.- . Layer 2 0..5 L iw i i m 6 O.JS . fl.tiXi ns.-v;. 0 210

Fig. 3A: Site specific data entry for scenario 2

Data entry for Scenario 2

UcKlBled

iaver

.SOliTC* L.iyer

Eiiisr v«rlic]l

itKSineM

0 6

0 5

Erfisr

Soil

V im Si-/

s;r.-

Soil Type

VertiMl

HV(J conn Ks Exponential

Patamsier. b

Tola!' porosity

rlffractionl

Effectf^e poroatiy.

ne tfraijtiom

Moialure

content

Ott ifractioni

Eifsinivis moiatura comenl

Qe ( I ractonl

•

Ca^:ailat»il Vert i ia l pore

water velociiy

ve ImeterVeari

S:ro rf fV. ; .05 O. iJ- 0 417 0 V i C.!M 146^

U>ar1

oe

OJ

LOiT,

scw,-Lox-i Lcor. 755 i.9 0.153 0412 O.Sl! 0.2:0 1.135

Lavsr 2 0 2 LCCrTi ' i zc r 1*7 rss 0.45! 040.4 • C i » 0.25- OS135 Layer 2 | 0 3 | Lccrr, | izcr \ rj7 | f.ii | 0.45; | 040.: | C jS

Fig. 3B: Default parameters as a function ofthe selected layer soil type

Selection ofthe soil type to represent multiple contaminated layers is also unique in SSRG. For example, in Scenario 2 above (Fig. 3B), the contaminated layer (Sand) under the source layer is now considered as part ofthe source layer. However, to err on the side of health, the most permeable ofthe two soil layers (i.e., silty clay sand versus sand) is automatically selected for the user and used in the computations. In this case, sand is selected. A similar logic is used for Scenario 3 (see Tutorial at the end of this User's Guide for a complete example).

It should be rioted also that the current SSRG version uses as point of compliance the water under the defined source. Scenarios 4-6 in the next version will compute contaminant transport in the aquifer to any defined point of compliance and calculate the applicable SSLs and SSRGs.

3.2 Model Equations for the PWV Module

The endpoint for the PWV module is the derivation ofthe mean travel time (Tmean) for each chemical in vadose zone. It is the mean retarded contaminant travel time in the vadose zone and is calculated by dividing the distance from the bottom ofthe contamination in the Source Layer to the top ofthe water table surface by the.mean retarded pore water velocity using the following equations 1-5:

12

AR304379

Equation

Equation name

Equation #

.,. j : . . . R mam , .

Mean Travel Time

1

v = ' • e .

<-Soil-pore water velocity

2

II,

Effective moisture content

3

(rr^r^J

Volumetric moisture content

4

0. Retardation coefficient

5

where

I -.lie,™

Lv V, R I e..

Ik lit

b . K< pa Kd

mean travel lime ro the top ofthe aquifer (yr.s) distance from the bottom of source layer to the water table (meter) pore- water velocity' in the vadose zone (nieter/year) unsaturated retardation coefficient (unitless) vertical uitiltiation rate tlu'oiigh vadose zone (meter/year) vohunetdc moisture content (Vw.ni5r/V\oii) (fraction) effective moisture content (fraction) effective porosity (fraction) total pnrosiry (fra:iioii) soil-specific exponential parameter (unitless) sanirated K parameter (iiie:er/year) soil bulk deiisitv (ks/T.) distribution coefficient ofthe cliemical (L/k2)

3.3 DAF/MZ Module

The dilution attenuation factor (DAF) and mixing zone (MZ) module calculates DAF and MZ values using analytical equations cc)nsistent with the USEPA soil screening guidance.

13

AR304380

GROUNDWATER PARAMETERS

Aquifer Mixing Zone Depth and DAF Parameters •? : • • • ' • : ' ' ' ' ' •

Variable

L K .

Da

1

0w

Bb

Bo

foe

Calculated parameters

0

0 .

d(calc)

DAF

dlln DAF)

Value

122 334

183

0.025

0.30

1.50

2.65

0.013

Unit .

m ni/yr

m

Ill/Ill

Unitless

kq/L

kg/L

Unitless

Description

Source lenotti parallel to qroundwater flow Aquifer saturated hoiizDntal l-iydraulic conductivity

Aquifer tfiickness

Huiizunlal liydiaulicgrddienl in aguifei

V/ater-filled Porosity

Bulk Density •

Particle den5ity in aqui'er

Fraction of organic carbon in aquifer

- • . •

0.43

0.13

16.5

5.5

16.5

Unitless

Unitless

m

unitless

m

Aquifer porosity

Air-filled Porosity

Calculated Mixing Zone Depth .

Dilution Attenualion Factor

Mixing Zone Used in DAF Calculations .

Fig. 4: Groundwater parameters

3,4 Model Equations for the MZ/DAF Module

34.1 Mixing Zone Depth (MZ) Equation 6 is used in the code to estimate mixing zone depth (d). This is the same equation used in the USEPA Soil Screening Guidance (USEPA 1996; 2001).

./ = (o.oii2.rf-^.•(i-('"-^"'^^' ' '^')

where

K = saturated horizontal hydraulic conductivity in the aquifer (m/year) i = horizontal hydraulic gradient (m/m) 1 = vertical infiltration rate through vadose zone (m/year) da = aquifer thickness (m) L = length of source parallel to groundwater flow (m)

Built into the code is the logic that if the calculated mixing zone depth is greater than the actual measured aquifer depth, the mixing zone depth defaults to the aquifer depth.

AR304381

3.4.2 Dilution A tten nation Factor (DA F) Like the MZ calculation, the equation for the dilution attenuation factor (Equation 7) is the same equation used in the USEPA Soil Screening Guidance,

^ • ^ : , 7 ,

where

K, i, d, I, L are as previously defined.

3.5 Results Module

The result module is the most sophisticated component ofthe model. It evaluates five fundamental logic criteria including:

i. Computation ofthe retardation coefficient of each chemical based on the chemical's properties and the weighted vertical seepage velocity through the vadose zone,

ii. Comparison ofthe calculated groundwater concentration to the action limit, iii. Comparison ofthe retarded, mean travel time of a contaminant to reach the aquifer to

the user-defined transport evaluation time. , iv. Comparison ofthe measured soil concentration and the calculated SSL and/or SSRG

to determine whether further action is need at the site. V. Comparison ofthe unit source total contaminant concentrations to the mass limited

soil screening limit (MLSSL).

Logic (v) is in development. An example Results Screen comparing Scenarios 1, 2, and 3 is provided as Table 1. For additional details on the data input and generation of these results, please refer to the Tutorial at the end of this User's Guide.

15

AR304382

Table 1: SSL and SSR(

Project Name: S Project Location Project Officer:. Date:

Scenario 1

Chemicals |c*iritarest)

l.!-DH;^lcfc^are

f'.Tinsi

Et lv<b«-.;6^

Sf/rene

l .^ lc<*eth. lene

X'h'f. c t i ' o r *

N«ph*BWM

SRGEvalualionofABC Nowhere To',\T)s lip

ot-n Lk;* 5/18.'20e8

rjeasured soil conoen |Ct| Kd (VZ) -

(mfllis) L K B

IME.C; Ze'E-Dl

9KE.C; 6«E'01

5 5 ; E - ; ; 4 72E-C0

40CE-:: I J lE - i !

4JJt+CL' :;.1M.'.U

5 4(E«<;.' 2 J2E.01

4 3.;E'C: 2.i6£'(0

CI results.for organic chemicals

Soil Screening & Remediation Goals (SSRG) Tool

Version: 2 (Inarch, 2008) Autlior David 11. Kargto. PhD.

" USEPA Reaon III

S Site soils

SSL and S

KdlOV/l LKa

7 56r-0l .

;s3E-ai

4 '2E-10

iCIE-?5

^.\^b-fl 2.:2=-0l

2 1-E'X.

SRG RESU

Retards tio'n IR)

6 98E-M

6.3.;E-M

3 75E-:i-

7.S6E-0:

l.'St-L'!

2SJE-30

l . 'SEJi

'

LTS FOR 0

H«aiTn»il Tlms.Thru

Vertlcat Ljy«f T l i yun i

?f5S.K

SSS. t t : ' •

5 I6E.C1

l»E.C2

2 44n.l^

;.!5E.tC: .

244EiCl

n o A M C CONTAMINANTS

. Cgw from ct

.'. (withcul Cgw from C( ' . d«(nid) (wtth degmd)

• ;7IE-!-

; S i i -^ ' :

2 . K B - y '

7 O.:E-J!

3 2't-'.^-

1 8;E-O.'

327E.0-

--.

• i.CiE<14

3 U E - I

1}

c 1.'I t : *!.',•

J.-7E-5J •

0

MClorP^G (n» l )

4'40E-0J

1 C'JE C'i

7 tQE-C'l

; CCE.5i

3l.','t-'Jj

2 CCE^'J

6.(OE-0)

Cgw • t u e d .

on MCL tJCLG.

2«EJ:4

5>/Ej;i

367E.«'

5.;-2E-CI

:^.•ct^..i

I.IOEJ:2

2.'eEJ:2

SJL mffKB

2 56EJ-J

fOTEJ!!

l.5iE-01

5.6SE-nij

b b i t ^ 7

? ?aE.O?

5 62EJ;2

•Furher Acton

(based on 3SL|?

VES

YES

VES

VES

Ybb

YES

VE5

99)0 mffKg

i.;6=-oi

2 5?;-03

i.;!E-rj7

;-5SE-06

1 VteHXl

3 44E-02

-:.62i'Ci4

Fyrthe Acton

(based c 33RS)

n

YES

W

NO

• »

v t i

YES

.•JO

Scenario

Chemicals (ofinttfest)

1 1-0icMcr«rnane

12-Dichl0f0€thy1ene (trans)

E'nylbenzene

S^Te^e

Tncniofoeyivlene

Vin/I chloride

Naphthalene

2

Measured cell coneen (Ct)

(m9%g)

I 00E.02

9 60E-02

5.64E-02

4 00E.02.

4.33E-02

5 48E-02

4 33E.02

Kd(VZ) LKg

7 66E-01

6.63E-0t

4.72E-0C

I.OIE-Ol

2 I6E.00

2.42E-01

2.16E.()0

• mov i ) UKg

7 66E.0:

I5.83E-CI

4.72E-00

l.OIE-OI

2 I6E-00

2 42E-(ll

2.16E-00

Retardation (R)

535E.M •

4.88E-W

2.78E-0I

584E-01

l.jJE-OI

2.37E-CC

1 33E-01

Mean Travel TlmeThnj

Vertical Layer. Tt (years)

6.7.5E-M

6.15E-O0

3.5IE-01

7.35E-01

t67E-0l

' 2 S8E-00

1.57E-0I

Cgw from Ct (without

. degmd) - .mgl

1 7IE.0I

I.83E.02

2.39E-01

7.03E-0O

3 27E.0I

1.83E.02

3.27E-0i

CgvifromCt (withdegrad)

m » l

3.47E^3

4.25E-0i

0

0

3 22E.0O

4.56E-02 .

0

M a or . PRO

(mg l.)

4 4C£-05

I.OCE-Ol

7a)E-01

1 CCE-01

5 00E.03"

2 ooE-or. 5 ME-03

. Cgw based on

t K L HilCLO. m g l

2 43E.CW

5.52E.01

3 87E-00

5 52E-01

2 76E.02

I.ICE.02

2 76E-02

SSL 1 mg'Kg

2 53E.04

i.O^E^ll

ISIE^OI

5.O9EH)C'

(;-.62E-02

6.SSE-03

e e2E-02

•Further. Action

(based on 551)?

YE.S

YE.S.

VES

YES

YES

YES

YES

SSRO mg.Kg |

1 27E.W

2.23E.02

1 91E.07

5 59E.06

6 72E.tll

240E.OI

5 62E-04

Further Action

(based on . SSRG)?

YES

YES

NO

NO

YES

YES

NO

Scenniio

Chemicals (of Interest)

1 l.i-Drcf'Jcroethane

.12- . bichlO'Mthylene 1 trans 1

Et'ryloenzene

Sryrene

Tric.'ilwrjethvlene

[ Vinvt ci'oridr •

1 Naphthalene

3

Measured soil conoen (Ct) '

(m»lig)

l.OOE-02

9.5flE-02

5.54E-02

•4.(K)E-02

4 33E-02

5.45E-02

4.33E-02

.Kd(VZ) LKg

7 56E.0I

6.63E.01

4 72e.n3

i.oiE-ai 2.I6E.O0

2.42E-01

2.ieE.0[l

HdlOWl • LKg

7 56E.OI

5S3E-III

4.72E-L10

lCIE-01

2.16E-00

2.42E-Ci1

2.ieE-»D

Retardation 1 • IR)

5.52E.C0

5 38E.O0

3.I3E.C1

6 53E.IJ1

14SE.t::i

2.KE.tJ0

l40E.i ; i

Ivlean Travel Time Thru

Vertical Layer Tt (years)

l.ME-OO

15IE-00

8.77E-0,n

.•e4E-0t

4 i6E-00

7.tSEJ;i

4.II;E-IIO

,. Cgw from Ct (without degrad)

.- m g l

1 71E.01

• i.eaE-02 2.39E.0I

7 03E.OO

3.27E.0I

I . 8 ; E . 0 2

3.27E-0i

Cgw from Ct. (with degrad)

mg'L

2.11E-0C

4.21E.0I .

3

0 '

I.84E-01

251E.0t

1 C5E-08

ItCLof .

(mflfL)

4.40E-C5

1 noE-oi 7 00E.0I

) OOE-Oi

iKiEJ)} 2 t!OE433

5 ME4J3

Cgw b.-ised on

f,1CL MCLO. mfli'L

2.43E-CH

5 52E.01

3 87E.W

5 52E-01

2.76E.02

l.tOEJ2 2.76E.02

SSL. ntft'Kfl

2.5eE-0«

5u7E-0t

191E.0I

6.3JE.00

6e2E-02

5.53E-03

8 62E-02

•Furthei Action

(based on SSL)?

YES

YES

YES

YES

YES

YES

YES

SSRO mg.'Kg 1

2.09E.03

• 2 26E.O0

1.S1E.07

5 6SE»06

1.18E-01

4 34E-02 •

6I52E.04

Further Action

(based on 55RG)?

YES

YES

NO

NO

YES

• YES

NO 1

Based on the above results, Tables 2 and 3 provide a summary interpretation ofthe results with respect to SSL & SSRG.

16

AR304383

Table 2: Summary Interpretation of Results (SSL versus SSRG) with initial contaminant soil concentration in parenthesis

Scenario 1

Scenario 2

Scenario 3

TCE (433 mg/Kg)

SSI. (>.i)2i--n.!

(;.(.:i:-o:

(..(.21-.-02

SSRG I.96E-00

6.72E-0I

I.I8E-0I

Vinyl Chloride (546 mgyTvg)

SSI. 5.<).Sl:-03

.r9.<;i.;-ii,;

. .';,SI.--03

SSRG 3.44E+02

2.40E+01

" 4.34E-02

t-I,2-DCE (950 mg/Kg)

SSI. 5.071--OI

5.07L.-0I

.r071-.-(.)i

SSRG 2.69E+03

2.23E+02

2.26E+00

Ethylbenzene (654 mg/Kg) •

SSI. i .< ) i r . - . o i

1.9 11:.-) 01

1.9 IK 1-01

SSRG 1.9IE-F07

. 1.9IE-*-07

1.9IE-1-07

Table 3: Summary Interpretation of Results - Required action (or inaction) based on comparison of site contamination levels of each chemical (in parenthesis) and calculated SSL & SSRG

Scenario 1

Scenario 2

Scenario 3

TCE (433 mg/Kg)

SSL

VES

• WIS

Yi-:s

SSRG

YES

YES

YES

Vinyl Chloride (546 mg/Kg)

. SSL

v'i-;s YES

M:."S

SSRG

YES

YES

YES

t-l,2-DCE (950 mg/Kg)

.SSL

vi.:s Y!:s YRS

SSRG

NO

YES

YES

Ethylbenzene (654 mg/Kg)

SSL

NES

Y[:s

YES

SSRG

NO

" NO

NO

For chemicals that decay, remediation goals (or SSLs) become more stringent as the source gets closer and closer to groundwater.

3.6 Model Equations for the Results Module

3.6.1 Derivation of Groundwater Concentrations The equations used in the SSRG model are all a form of a linear isotherm (with exponent = I) based on the Freundlich equation and used in USEPA in Soil Screening Guidance (USEPA 1996; 2001). The basic equilibrium partitioning equation for predicting groundwater concentration, given a measured or assumed soil concentration (CO for mercury (Hg) and organic chemicals that volatilize but do not degrade, is Equation 8:

C/.[lOOOug/mg] ^

where

DAF = Dilution Attenuation Factor (unitless) Ct = total soil concentration (mg/kg) Cgw = coneen. in groundwater at hypothetical well at edge of source area (|ig/L) Kd = distribution coefficient (L/kg) H = Henry's Law Constant for volatile organics/mercury (unitless) 0w = source zone water-filled soil porosity (Vwaier/Vtaiai) 0a = source zone air-filled soil porosity (Vair/Vtotai) pp = soil bulk density (kg/L)

17

AR304384

The groundwater concentration equation for metals, other than Hg is Equation 9, while Equation 10 is the groundwater concentration equation for organic chemicals:

^'r- -UK+i^-o.,)^

-/{DAF)-[lOOOug/mg]

i ^ ' . . P0

where

Tv: is the chemical's half life and the rest of the parameters are as previously, defined.

3.6.2 Derivation ofthe soil screening levels and decay adjusted soil screening levels The code currently calculates two types of SSLs for each analyte; the SSL based on the USEPA guidance, and a decay adjusted SSL that is influenced by time of travel of the chemical in the vadose zone and the chemical's half life. Equation 11 is the SSL equation for any metal analyte, excluding Hg: '

MCL • DAF • Km-SSL,,,, =

P n .-< - 0 . m T , i , , J T ^ , , )

-/[lOOOug/ing]

.11 where

The parameters are as previously defined. The degradation half-life (T'/z) is assumed to be infinite for metals, and The MCL parameter is either the MCL or the PRG value in the USEPA Region III RBC table (which can be accessed from the USEPA website).

For mercury, the SSLr/, is calculated using Equation 12 while for an organic analyte Equation 13 (which includes first-order degradation) is the applicable equation:

SSLr

MCL : D.iF • i A.'„. -f {e.,.^H-ej

Pb i.-l36P3 r,.,„, ••.'•,,.) -/[lOOO ua'uie

.12

SSL., , = MCL • DAF • \ K, + - ^ ^ '-

-/[lOOOug/nig]

13

AR304385

4.0 References

1. Kargbo, D.M. 2006. Soil Screening and Remediation Goals (SSRG) Tool. USEPA, Philadelphia, PA. '

2. U.S. EPA. 1996. Soil Screening Guidance: User's Guide. USEPA, OSWER, Washington D.C. Publication 9355.4-23; EPA540/R-96/0I8

3. U.S. EPA. 1996. Soil Screening Guidance Technical Background Document. USEPA, OSWER, Washington D.C, Publication 9355.4-17A; EPA/540/R-95/128

4. U.S. EPA. 2001. Supplemental Guidance for Development of Soil Screening Levels for Superfund. USEPA, OSWER, Washington D.C, Publication OSWER 9355.4-24

19

AR304386

5.0 S S R G T u t o r i a l

5.1 The Problem \^

Company ABC hired a consultant (Super Screen, Inc) to develop a Remedial Investigation/ Feasibility Study (RI/FS) for the Superfund site, NoWhere, that has resulted in the contamination of soils at the NoWhere site within ABC's property. Initial screening using the USEPA soil screening guidance documents (USEPA, 1996; USEPA, 2001) previously resulted in very conservative soil screening levels (SSLs). The screening results indicate that if site remediation is to be based on the calculated SSLs, it will require the removal or in-situ remediation ofthe entire 100-acre site to a depth of at least 20 feet at a cost of $81 million. SoilScreen met with regulators to determine a reasonable approach that will be cost effective and protect human health and the environment. The use ofthe recently developed. Soil Screening & Remediation Goals (SSRG) software that incorporates both site specific geotechnical and chemical data to generate SSLs and SSRGs was suggested.

5.2 Data Requirements for SSRG Tool

Following extensive discussions with SoilScreen's in-house technical staff and meetings with environmental regulators; SoilScreen decided to generate the following data.

5.2.1 Vadose zone parameters Surface and subsurface soils are contaminated and there are 5 different soil layers (including a surface layer) identified in the RI between the surface and groundwater. SoilScreen decide;d to generate the following parameters for each layer between the surface and groundwater, as required by the SSRG software:

i. Soil type of each soil layer; ii; Layer thickness (1, m);

iii. Vertical hydraulic conductivity (Ks, m/y); iv. Exponential parameter (b) V. Total porosity (nt, unitless); '

vi. Effective porosity (ne, unitless); vii. Moisture content (9w, unitless);

viii. Effective moisture content (9e, unitless); ix. infiltration rate (I, m/y); X. Soil bulk density on a weighted average basis (Pb, kg/L);

xi. Particle density on a weighted average basis (Pp, kg/L); and xii. Fraction of organic carbon in soils on a weighted average basis (foe, unitless).

5.2.2 Groundwater Parameters All ofthe required groundwater parameters have already been generated by SoilScreen during the RI stage and were used in generating the SSLs. These include:

20

AR304387

I .

ii. iii. iv. V.

vi. vii.

viii.

Source length parallel to groundwater flow (L, m/y); Aquifer saturated horizontal hydraulic conductivity (K, m/y); Aquifer thickness (da, m); Horizontal hydraulic gradient in aquifer (i, m/m); Water-filled Porosity (Gw, unitless); Aquifer bulk density (Pb, kg/L); Aquifer particle density (Pp, kg/L); and Fraction of organic carbon in aquifer (foe, unitless)

5.2.3 Chemical Parameters SoilScreen decided to research the literature for the latest data generated on chemical fate parameters for each ofthe chemicals of interest. For each chemical, SoilScreen generated the following:

i. Half life for each organic chemical (Ti/2, y) ii. Henry's Law constant (H', unitless)

iii. Octanol-carbon partition coefficient for organic chemicals (Koc, L/Kg) iv. Distribution coefficient for metals (Kd, L/Kg) v. Chemical solubility (S, mg/L)

vi. MCL or PRG (mg/L)

In addition. Soil Screen compiled the concentration of each chemical at the site at various depths.

5.3 SSL and SSRG Modeling Steps

5.3.1 Step I - Install and open SSRG software

ACTION: SoilScreen copied the MS Excel program (SSRG Tool, Ver 2.0) to its hard drive and opened the software. When asked whether to enable macros or not (Fig. T-l), the company selected "Enable macros" as required by the SSRG software.

"ig. T-l: Excel security warning

COMMENT: The SSRG software contains four worksheets: USER-INPUT; SCEN-INPUT; SCEN-ORGANICS_RESULTS; and SCEN-METALS RESULTS worksheets.

21

AR304388

5.3.2 Step 2 - Enter data into USER-INPUT worksheet data entry forms

ACTION: SoilScreen opened the USER-INPUT worksheet and entered the site specific data it had collected with respect to the vadose zone parameters, groundwater parameters, and the fate parameters for each chemical of interest.

COMMENT: The USER-INPUT worksheet has three (3) input areas:

a) The Vadose Zone Parameters Entry Forms; b) The Groundwater Parameters Entry Forms; and c) The Chemical Parameters Entry Form.

Vadose Zone Parameters Entry Forms: There are three possible scenarios of contamination pattern in SSRG and users are required to select a scenario (or scenarios)

, that best match their site. SoilScreen concluded that any ofthe three scenarios could apply to their site and decided to utilize all three scenarios. Sample data collected by SoilScreen will be entered into the blank USER-INPUT worksheet provided in Fig. T-2.

VADOSE ZONE PARAMETERS ENTRY FORMS Data en t ry tor s c e n a r i o I

M j i d c d k• •cr

Source Layer

U y . r l

Layer 3

Layer 3

. L«y.r4

Fn!,T

• tN[*nc53 .10<1 1^(-

V*iti-.-il H>d

K J invv) Etcon»ntai

Piiruintlct. b •Total cwosit*

nl lirxi'urt) :ontflnt

FfpfJiwiYii thj i*-conlent

Doto en t ry (or Scenar io 2

MxltWlKSI

Source Layer

Liy.r t

Err.fr Vefiicai

tlicltfieis Uie<t

Vertcal H>d ccnd

Ks inAi ! Exponrni-al

PLiianii-tet. b nl I'rarttcnl

Effeche t.'-osture :onten!

Q'AffiaclionI

Efedivi; nioistufe ccflleni

1 1 1 [ 1 1

1 1 1 1 1 1

L . v . r 2 i 1 1 1 1 1 I . I

Data ftntry tor S m n a r i o .1

Mj<ii:\v.'i\aie>

Source Layer

Enter Vcjlicai 5o. T^K E*p3iKntiol

Parti i ir ier.l i Totj] pwcortr 30 Oily

ni-f loUcj ' i i N'oiyu'tconcnl

0 . (Ki'.lii.Hii

Eftcojc n-i.i?'.ji;c:-r,tciv.

' I l l l 1 1 '

Layer, 1 1 1 1 1 1 1 1

Add i t i ona l so i l da la ent ry

Infiftratwn

idlo (ni'Vi;

Bull'

• JtFi 'oi lv (ng. 'Li

Fonide

0«[iMly (kt;/L)

Frac. ora corbcn

(ui iUltJbi i)

Fig. T-2: Vadose Zone Parameters Entry Forms

In the SW area ofthe site, only the surface soil (Source Layer), estimated to be a Silty Clay soil from field observations, is contaminated to a depth of 2 ft (0.6 m). Depth to groundwater from the soil surface is 8 ft (2.4 m). Based on soil boring data subsequently

22

AR304389

gathered by SoilScreen, soil layers encountered below the contaminated surface layer were not contaminated. They include:

Sand layer (Layer 1), 2 ft (0.6 m) thick; Loam soil layer (Layer 2), 2 ft (0.6 m) thick and below the Sand layer; Sandy Loam layer (Layer 3), I ft (0.3 m) thick and beneath the Loam layer; and

iv. Loam soil layer (Layer 4), 1 ft (0.3 m) and below the Sandy Loam layer.

This warrants the use of SCENARIO I (Fig. T-3) in modeling site SSRGs. SoilScreen entered the vadose zone data for Scenario I in the appropriate data entry form (Fig. T-4).

r^ "*

J f^^ i i ^ ' i - u^ i ' ^ i

Vif-i i!ir

Vadow Zonfl Layer'

Vadose Zone layer 2

Vadose Zone Layer 3

VadoiC Zanp Layer

Aquifei Layci

> . ' ' j f ' f ' ^ ^ i

All-layer Material Properjier. p f

Fig. T-3: Schematic of SCENARIO 1 contamination with only the source layer contaminated

Data entry tor Scenario 1

ModeW laver

Source Layer

Layer 1

UyerS

Layer 3

Layer 4

ItiicVness

06

06

U.S

0.3

OJ

• SwTvoe U5ed

SlIIV Clav

Sand

Loam

Sond-v Losm

LMni

Vertical Hyd r/:nd

Ks invv)

; i ^

5C0l)

BUU

790

800

. Parameter, b

y y

42

5

5

Tntal pf i'eir^ nt 'ftacticnj

0 4B

Qi-t

0.4t>

0 45

0.45

Effective r nfrfyty

w tftacliiwj

t i » l l

0 405

0.40',l

0 402

0.400 •

fi oisluie

• QA (fijclionj

o.jao

0.180

:>.Zi>}

0 233

oao

Effective mttsnjie a-rtftni

Qe (fraciionj

0 34U'

0.155

0 210

0210 •

0.210

Fig. T-4: Data entry for Scenario 1.

In the central area ofthe site, contamination has migrated below the Source layer and contaminated the Sand layer as well. While traces of groundwater contamination are

23

AR304390

evident, the soil layers beneath the contaminated Sand layer are essentially clean. This warrants the use of SCENARIO 2 in modeling SSRG (Fig. T-5). SoilScreen entered the vadose zone data for Scenario 2 in the appropriate data entry form (Fig. T-6).

1 " '•!

- / / - = % • .

Vado<4 Z>rt ' . I r ^ 1

VMo** Zvi« Lirar 2

AH M/i-rWrt-rrtirf mri-ft ir i ' fi^

Fig. T-5: Schematic of SCENARIO 2 contamination with the surface layer and the layer beneath the surface layer representing the Source layer.

Data entry for Scenario 2

Modeled layer

Source Layer

Layer 1

Enter Vencal

ttiicKpess

• 0.6

05

05

o.;i

• SoilTyoe

Used

Vertcal Ry j

cond

Ks iWv'l

Exponential

Par?iTtetef. b

Total pc^osity tit (fractioni

Effects porosis

ne ifract-cri

Woistuie conieni

O-v {fraction)

Effecttw moisture ccdtent •

Oe (fiacJior.)

• S a n d 5aw _ A2 0 44 0.405 0.180 __ 0 155

SantJv Loam 790 . . 9 0 45 0.402 0.233 __._ 0 210

Layer 2 03 L o a m 3CiO 6 • 0 45 0 400 0 2X. 0.210

Fig. T-6: Data entry for Scenario 2.

In this scenario, the Source Layer is equivalent to the Source Layer (Silty Clay) plus Layer 1 (Sand) of SCENARIO I. SoilScreen decided to use the Sand layer and its measured vadose zone parameters as the soil type and parameters represented in the model for SSRG calculations since the Sand layer is the more conservative ofthe two with respect to its ability to transmit fluids vertically to groundwater. Actual vertical pore water velocity may be less than represented by the Sand layer. Similarly, the Loam and Sandy Loam layers beneath the Source layer are grouped as one layer (Layer 1) and the more conservative Sandy Loam is used to represent Vadose Zone layer 1 in SCENARIO 2.

Finally, at the NE corner ofthe site, almost allthe soil layers are contaminated with significant contaminant concentrations in ground water. This warrants the use of SCENARIO 3 in modeling SSRG (Fig. T-7) and SoilScreen entered the vadose zone data for Scenario 3 in the appropriate data entry form (Fig. T-8).

24

AR304391

SftuxeL^^tM

"" n.,'% ' / /^ ' i l

•'»doc« E>n> Ltyvr i

. \q i l !Cf Lavcr

^ u ,'rt>'tr,<(<\?t;nfr^ /Vri>c'fif;;

Fig. T-7: Schematic of SCENARIO 3 contamination with the surface layer and the layers beneath the surface layer (except the layer above the groundwater) representing the Source layer.

Data entry for Scenario 3

lilodeletl lav«

S o u r c e Laye r

EniB

Veitcal

Uiicttress

0 . 6 -

0.5

0.6

0.3

•S.3J T-,Te

Usci!

Vertioal Hyd

cond

<s f tn fy j ' •Paraneter, b Total jWTKity rt; (Irac'joni .

EHeclrft i>y05it.

n? (Iraclion) Moisture content

0.V fftacli'jn)

Effeclive moisture content

l > (tractiojii

Sand 5000 . . 4 2 . . . 0.4^ 0 405 0180 0.155

, . . - . •

. Layer 1 0.3 Loam eoo 6 0 4 . 0 400 0230 • 0.210

. Fig. T-8: Data entry for Scenario 3.

Like in Scenario 2, the most conservative layer of all the contaminated layers (Sand) is used to represent the Source Layer in Scenario 3 (Fig. T-8). The layer next to groundwater (Loam) then becomes Layer 1 in SCENARIO 3.

It should be noted that this scenario closely mirrors the scenario represented in the USEPA Soil Screening Guidance.

Additional vadose zone parameters are entered as weighted averages in Fig. T-9.

Additional soil data entry Infiltration

rate (m/yr n. 0.25

Bulk ijensity (kg/L) - | density (kgj'L)

Particle Frac. org carbon (unitless)

1.5 2.65 0.01.3

Fig. T-9: Additional soil data entry

25

AR304392

It is anticipated that the majority ofsoil contamination patterns at most contaminated sites will be represented by one or more ofthe three scenarios in SSRG software.

Groundwater Parameters Entry Form: In this form (Fig. T-IO), SoilScreen will enter the same parameters that were used to determine the dilution factor (DF) in the SSL determination. There are a couple of things to note here. First, it is commonly . recognized that the foe in groundwater is different and lower than the foe in soils. SSRG allows the user to input foe values for the vadose zone and groundwater separately. Consequently, the partition coefficient for each chemical in soils will be different than that in groundwater. Second, SSRG will prevent users from violating certain basic physical principles. For example, the sum ofthe water filled porosity and air filled porosity cannot be greater than the aquifer porosity. When this happens, SSRG prompts users to check their data input.

GROUNDWATER PARAMETERS

Aquifer Mixing Zona Depth and DAF Paramstsrs ,

Variable

• L

K

Da

1

0 ,

3t

PP

f«

Calculated parameter*

Q

0. d(calcl

DAF d(in DAF)

Value

U'2 334

18?

0.025

0.30

• .f.0

2.66

0013

Unit

n n/yr

n

• rT..'|-i

l.!nit!es5

., kci'.

W-Unitless

Description

Sou'cs iengtfi patailei la 3n.iunJwater How

Aqu fftr 5atui£tet1 hof^zontal hvdr.juiic C(3nciu~tivi:y

Aqu fer iliiciiness

Horizontal |-iydr,iulic ciad'efit in aqoifer

Watsr-filled Poiasitv

Bull< Density

Parbi;te density in aquifet

Fijclion of org;anb W;rbOT n aquifer

0.43

0.13

16.5

5.5 16.5

linillflss

ljnitliis;i

n unitless

.n

Aquiff-r nrrosify

Ai'-filled Pai05ily

Oalcuialed Mminc; Zone Depth

Dilu'.icn A'.lenuelionFaclor

Mixtnq Zone Used in DAF Calcui..5tions

Fig. T-10: Groundwater Parameters Entry Forms

Chemical Parameters Entry Form: SSRG has an in-built list of organic and inorganic chemicals with data on: half life; Henry's Law constant; octanol-carbon partition coefficient for organic chemicals; distribution coefficient for metals; chemical solubility; and health-based MCLs and PRG. A user will simply click on a cell under the column, "Select Chemical" to select a chemical of interest. In addition to fate and transport parameters for each chemical, users can also enter the measured concentration of each contaminant. It should be noted that contaminant concentration is not needed to calculate an SSL or SSRG for that chemical. However, the concentration of each chemical in the soil,is used to generate the expected concentration ofthe same chemical in groundwater whether degradation is assumed or not. SoilScreen used the Chemical Parameters Entry Form to enter the chemicals of concern (COC) at the NoWhere site. These include: 1,1-

26

AR304393

dichloroethane; 1,2-dichloroethylene (trans); ethylbenzene; styrene; trichloroethylene; vinyl chloride; naphthalene; barium; cadmium; chromium VI; and mercury (Fig. T-I I).

CHEP.1ICAL PARAMETERS ENTRY FOR^?

Setea

cre.micais

• |5fittte-e5:|

Co.ncEr.ituion

Ir.rtiilCV'

ing.'<5i

Has Life

Tw

;y,-5;-

H?nrv"SL3A'

Cc.-iji3r: ;H-|

Crr.5r.^icne-j

crs.tiicai

sci i i i i iv I'S'.

r c l

OcDnol-C

Fat Ccsff

K.jt I'.iKgl

MCL

sr PRG

tnj.Vi

1 SELECT ORGANIC CHEMICALS AND ENTER PARAMETERS

'.j-D«:.iOK>;lf3n€

Etr.vicenzer.?

S^rsne

T.HcnioriisTiy'fne

vinyl cnijrcj

H33r:nDier.?

1CO.0

SM.C-6H.0

4M.0

4i3.D

S+t-.O

0..;50

0 700 C.027

0.O7"

5 COO

0.250

11132

,

1.G70CI

0.335D 0,J23:i

0.1130

0.4220

1.1100

0.4220

56.?

52.5

262.0

• 776.0

185.0

16.6

165.0

i . ;C : *5 -

I.CCz<'1

-.oc;<-i

1.00EJ31

5.00E.03

2.00EJ]3

5.00E.03

Chemicai

10! interest)

ConcentM-io.i

in soil iCt;

(mg.'itgl

Haif Life

T,..j

(Yrs)

He.nry's Law

Constant .:H'i

Dit iensionl^ss

Ctiemrcal IWelal Solubilir,'

i,S\ Dis^rCoeff

m g . l KcfL.'Kg;

.MCL

or P.=?G

I'mg/Ll

1 SELECT INORGANIC CHEMICALS AND ENTER PARAf.1ETERS

Sarium

Cadrriiuni

Chromium VI

Mercury

12.-343 D

234.0

7,567.0

676.0 0.4«7

41.0

75.0

19.0

5-2.0

2.60E-01

1.&GE-03

.5-50E+00

1.00E+00

Fig. T-I I: Chemical Parameters Entry Form

5.3.3 Step 3 - Select and display data for use by SSRG in SCEN-INPUT worksheet

ACTION: SoilScreen opened the SCEN-WPUT Worksheet to find all the data entered in the USER-fNPUT worksheet displayed in the appropriate cells of the SCEN-INPUT worksheet. The company is interested in seeing how the default data compares with the site specific data.

COMMENT: All data entered in the USER-INPUT Worksheet gets displayed in the SCEN-INPUT Worksheet (Fig. T-I2). The data for each soil layer is used by SSRG to calculate a Vertical Pore Water Velocity (Vs, m/y) for that soil layer and is displayed in the last column.

27

AR304394

Mcd4t<d l iyM

En:er v f r t ie i l

n i e k i o M Ertar

ScllTyFW SolTyp*

U«*d

VcrtlMl hyd eoic K K m / / l

Ex3cn*n:ljl P«rimet#r. b

Toti l pOTOirtpF

rt ifnctlon)

Ef\)rtt^e oofMlty

nt ( l "ct lon)

Honluio contgrt

Qw (tracltoi)

Ef tet .v t moi t tan

' cortont Qe (fract)»n)

Cttcu R M

watei v«tedt) Vi(.-Tttt«r.V(iO .

Scurc:e Layer : f l

Laytr 1

Layer 2

3 0

Dl )

Lay«r 3 J J

Lay . r4 J .J

3 i l v OkJv 32 9 SI 0.48L U J 2 3 j J!.U 0 34U 0 733

Sand

Loam

MOO

6C0 r5

0.J4L

0 4r.C

U405

o«oa

3 t^O

3.230

0 -..«

O.'tO

1 53!l

1 223

Sartdy Loam ;to <J O I K . • nao? J 23.1 0211) 1 2.11

Lodm «C0 e 0 46C 0.403 3 230 0210 • 1.223

: ; i e a r a I M P O R T U S E R N P U T d a t a Clear i Gelect Soil Type

U o t t M liyer

Source Layer

E«er. v.!rtjcll

I h k t n e t i

' i n

Enter ;6ll

Typ.

Soil

Sand

Verticil H>ll

cond

50011

Eiponitntli l Pir i tnetM. h

32

• Tot«l-poffitrty

nll^rndlon).

0-14G

. EftMtive • pofMity fi.< (Fraction)

0.405

Moi»tur« Cftnt*int

Qwtrractlen)

Ol£tl3

E f l K t M . ' moiituri* £i3ntAnl

f ie ifradion)

0.155

VwtJcil pora v/iwr velocity

V i (nwtfirfyeirj

1472

Layei 1

oa Sandy L u a i i i n 450

I Lonm I 800~ Layer 2 I 0.3 JJ50 0.400 0.230 0.210 I I 070

Clear & IMPORT USER INPUT data C l e a r s Select Soil Type

Uoddletl ' uysi

Source Layer

Erier

lUickneM

0.6 0.6 -

06 n.i

Enter' Soil Type

Soil •., Type

•UJid.

San't

VertictI Hyd cond K)|nfy|

.•^noo

Exponential Porameier, I)

4?

To:.l poFMlly

lit(fra;tionl

(• 4/10

ElfKtho peroiity

no (tnctloil

0 405

. Hoiituie eonlert

QwilTlctor.)

OlflO

E»ectr.e mclsturtoontenl

Qe(tnalon)

(1 -.S'l

CituWed Vi r lcd pore wite- vtlocit/ Volmetert^ear)

147?

Layer 1 | 0.3 .oain 8iX) 0.450 0.400 0.230 021.")

Clear S IMPORT USER IMPUT data Clear* Select Soil Type

1 O.'O

Fig. T-l2: Scenarios 1-3 vadose zone parameters and calculated pore water velocities.

One convenient feature of SSRG software is that the user can toggle between the data entered in USER-INPUT Worksheet and the default data in the software's database. SoilScreen was interested in comparing the default data for the soil type of each soil layer. To display the default data in Scenario 1 fbr the soil layers encountered at the site, the SoilScreen modeler clicked the button "Clear & Select Soil Type" which displayed the following (Fig. T-l3) empty data screen. . •

28

AR304395

DEF.(\ULT PARAMETERS FOR EACH SOIL TYPE

U c d t k d b y e -

Source

U v e r

Enter

. w r t r « l •

l h i c k n e ; s '

0.6

U - > e r 1 C.6

t i v e r I 0.6

u , t , : . U

•

U v . r < C.:.

Enter

So i l

Soi l

Tvoe

U t e d

V e r t i c i l

•v. » n d i i

Infrt

•r .

E i i p o t e n t a l

• Paran- r - t r .

• •; 1

' . Taa l

.porcs i ty

r: •

( I r K t i o n I

E l * « t v e .

ne .

f f ratnr in ' i

H i i i t t l i n

con- .«n

t h o l i o n

mo is l u i c

c o n w r t

Qe . ..

^ t t s K i O l i

Ca l i i t la ted

V c n i p i l p» rc

w s l f r

. i ^ loc i ty

' ' j .

l m t t e i V « a r t

1 1 I l l l 1 1 1 1 1 1 1 1 . I I I l l l 1

I I I l l l 1 Fig. T-l 3: A clear entry screen following the clicking ofthe "Clear & Select oil Type" button

I

Any site-specific data previously carried from the USER-fNPUT Worksheet is temporarily removed for default data to be entered.

The following should be noted:

11.

111.

The "DEFAULT PARAMETERS FOR EACH SOIL TYPE" statement is displayed on the top ofthe data entry screen to indicate any selected soil type from the drop down list will display default values. The layer thickness values entered into the USER-INPUT Worksheet do not disappear but remain on the screen. Clicking "Clear & IMPORT USER-INPUT data" will replace any default data with user input data. No data can be entered into any cell in the SCEN-INPUT Worksheet except to toggle between the two datasets.

The default parameters for the soil types entered in the USER-Input Worksheet are displayed in Fig. T-I4:

DEFAULT PARAMiETERS FOR EACH SOIL TYPE

H c d . l e d

t i y t r

Sou rce

U 7 « r

t . . ( . r 1

E jn i r r

v ^ ^ : o a l

Ih iGkntSS

0.6

« L . . , . r ! C.6

L i 7 « r I 0.3

U - / s r 4 C.3

Er i tc r

Soil Type

•S i l v

Cts -

i s - - :

L c i - -

I c s r r .

Lef t . ' .

S o i l

T) j>o

LisctI S I : ,

C I . - ,

V e n i t a S

Hyd

oond

. t i :

imly|.

: t .

i o r d ecy

E i p o n e n c r a l

b

. IC.^

_ 4 « .

Tma l

poros i t * /

l ( l i f - : i l>nl>

• : 4 ; 9

p c r o t i r y

n t

Ifrjctionl

w ; ;

M o i & l u r e

c o n t e n t

CI" IfrjMioiil

: . ; = J

EfTec l iv r

mo icLu fe

c o n c e m

Q e

i l t lKm)

•:-.;4e

;4 . r o j v 3.tr-: o.tee

C}ls.ulr.ed V e n i c a l poi^e

w a t e r

v e l o c i t y

V t

(meur'yeirl

>.:•,«

1 « T

l : « m 157 ! . , '9 0 4 : 3 5 j ; 4 i . l z i . • ; e 7 5 . : - !

•Ssn*",

t i i i m - 5 5 4 5 C'4=3 D . j i : • i . u : • , , , , j 1 i;5

L z s n :,- 5 « 0 4 « 3 . j ; j 3 . :5c - e : , : : s

Fig. T-l4: Data cells filled with default parameters and calculated Vs based on the default parameters.

Differences in the user-input data and the default data resulted in differences in calculated Vs. This process can be repeated for each Scenario.

29

AR304396

A similar concept applies to the chemical parameters where the user can toggle between the user input values and the default values in the SSRG database.

5.3.4 Step 4 - Display & print results

ACTION: SoilScreen openecl the SCEN-ORGANIC_RESULtS worksheet to review and print the results of their modeling exercises.

f .

COMMENT: All calculated parameters including the SSL and SSRG results are displayed for the selected organic chemicals and metals. Calculated

. parameters include:

i. Kd in the vadose zone (Kd(VZ), L/Kg) ii. Kd in groundwater (Kd(GW), L/Kg);

iii. Chemical retardation (R); iv. Mean travel time through the.vertical layer (Tt, years) V. Expected concentration in groundwater resulting from onsite

contamination and with or without degradation (mg/L) , vi.. SSL and SSRG (mg/Kg). . ^' .

vii. Further action warranted based on comparison of SSL or SSRG and the measured soil concentration of the chemical.

It should be noted that with metals, no SSRG are calculated since there is no degradation ofthe chemicals. Only SSLs are generated and will therefore not be featured in the tutorial. This is consistent with the USEPA guidarice-on SSLs. -

Based on the parameters entered by SoilScreen in the USER-INPUT Worksheet, the results (Table T-1) show the following:

i. All SSL numbers are much lower than SSRG for each organic chemical ii. Time of travel decreases as the contaminant source gets closer to groundwater.

iii. Concentration in groundwater increases as the source layer gets closer to groundwater.

iv. While SSLs remain constant for each chemical irrespective of the scenario, SSRG decreases as the source gets closer to groundwater.

V. Based on the concentration of chemicals measured in soils, the SSLs indicate that further action is needed for each chemical.

vi. However, on the basis of SSRG, no further action is warranted for 1,2-Dichloroethylene (trans), Ethylbenzene, Styrene, and Naphthalene for portions ofthe site represented by Scenario I. The chemicals 1,1-Dichloroethane, Trichloroethylene, and Vinyl chloride require some further action. As i contamination gets closer to ground water as in Scenarios 2 & 3, Styrene is added to the list of chemicals that require further action.

Each of these results can be printed by simply clicking the print button.

30

AR304397

Table T-l: SSL and SSRG results for organic chemicals

Projeot Name: SSRG Evaluaiic

Project Locat ion : Nowhere To

Project Off icer: .John toe

Date: 3i ia'?0()S

S c e n a r i o 1

F.^sured coK

Chemcat) eoncen (Ct)

(ofintarest) { f ^ M }

i . tOo- lotcsthans ; OCE.C-2

•..2€'irr^.tci\^,yerK

(iTini i tr-oCli.Ui;

E*>*«t . ; ' . re 6 51E.C2

Sr/tfene 4 t>;E.C;

T.TCTi:.nerh',i^nfr 4 3JE.C2

••.••(•vichijnd? :.4^E.C2

IJ» ,^ i * ; i«w 4.11l=.l!?

riofABC '.nship

Kd(V2)

7 64E0-:

o e J b J i l

i 7;E-CIJ

1 : • • ; .< t

2 l ( E - ( 0

2 J 2 E - : ;

5 i c = . r n

Soil Screening

s si:e soils

S S L a n d S

KdtOtWl

' . M = J ! I

s.Kc- 'J I

l . ' 2 E - ! »

1.0 IE-:--

; ts-M 2 J : : J ] I

) 1^-m

SRG RESU

Retardation

(RI

6 3 E - J 0

•i .. l i t: . i l l

3 7SE-3t

' S E ^ ' t

l . -SE^ ' i

2. -»SE-JO

1 ' ap - r i t

& Remediation Goals (SSRG) Tool

Version: J (March, 2008). Aultior: David M Kargbo. PtiD

USEPA Region 11

LTS FOR 0

Moan Travel

T imoThju

Ver t ioa lUye ,

T t (ye j rs )

•: 55E.ro

! bo r . l J I

; i 6 E J ; i

1 J9E.C2

2 U r . n i

3 : - 5 S - ! X J

J i 4 - . f : l •

9G/ry<'C C O N T A M I N A N T S

Cgwi rwn Ci

(Wth»Jt Cgw from Ct

deoraifl wtth cieorjd)

. m&T. mg.'L

1 7 t E O ;

1 * t - : v

2 33E-D1

7 O E - K

527E-0^

1 a3E-:2

.-.77F.ni

lO IEOJ

J.-.JbO^

0 0 •

1 i lE 'CC

317E.03

;.,

MCL or PRO

h » . i . |

4 fCE-:5

. i Wb-Ul

7)CE.01

l.JCE-Jl

• 5 > J E - M

2 EE03

fl . t r r . T i

C j * .

Ixised

on M C I .

IJCLO.

2 .«E- . y

3.;21:-)1 •

3e7E.05

5. I2E01

2.;6E-)2

I.ICE-)2

9 : i iF.W

S S .

m g K g

2 5 e E O i

01' . ' ! : .^, ' !

I .SlE-01

5.?.SE-I»

iS2E.12

5S8E-0J

rtfi?Fil?

'Funtwr

Aetloa

(baled j n

»5L)7

t-ES

" c S

•-E-S

YES

'ES -E-S

"F . t

1

runl ier

Aotion

SSRO I l K s e d o n

m j rKs SSRSl?

: . 3 £ £ - a iES

2.{>!rcH3 NO

t .5 IE^ :7 NO

; . 5 ; E - ; 6 MO

l.3fE-CC 1 t i

3.44E-C2 T E ;

T n : F . r 4 t j o

Scei in i io

CliemiKils

• (ofuitereel l ...

I t -D iO i l o roe thane

t .2 -

Di.:hk)foefh/tene

i t ransi

Elt-,ylbenzt^e

Styiene

Tr^onlofoettivlene

Vinyi ch t ' f t ce

Naptithalene

2

l i k u u n d soil

oorKen (CI)

|r>111.1<lll

•1 .00E '02

9 .50E-02

6 .54E-02

•t.COE-02

J . 3 3 E . 0 2

••i 46E*02

•1.33E.02

l U I V Z )

7 66E-01

6 a 3 E - 0 i

4.72E.CO

I . O I E H ) !

2 . l r :E*00

2 J 2 E - 0 I

2.16E.OO

KdlGWI .

7 55E.01

• 6 .83EJ ] l

4.72E-0O

1 0 I E - 0 1

2 . I 6 E - 0 0

2.42EJDI

2.16E-0O

•

Reta/datlon

(R|

5 35E-00

4 8SE-00

2.78E-0I

5 84E.0I

•33E-0I

2 37E-0O

1 33E-OI

Mean Travel'.

• Time Thru

Verdoal I j y e i

T t tyea, . )

6 .75E.00

6 15E-00

3 . 5 I E - 0 t

7 3 5 E - I ] !

1.67E-01

2 9 9 E - 0 0

V 6 7 E - 0 1

Cf lwfroni Ct

. (\VitlK«lt ,

. degrad)

m a t ' ^

1 7 t E . 0 t

1.BflE»02

•2 3 9 E . 0 I

7 . 0 3 E . «

J .27E*01

1 8 3 E * 0 2

3 2 7 E . 0 1

C f lw f r omCI '

(wtth dearad) .

3.J7E-03

J.2EE-0I

0

0

3 22E. i ;0

•(.56E-02

0

MCL or .

• PRG

(nO'L)

4 40E-05

l . K E - 0 1

7 ( » E - 0 1

. lOOE-01

5.C«JE-03

2C')E-03 •

5 00E.03

Cgw

based on

M C L

MCLG.

2.43E.04

5.52E-OI

3 87E.(10

5 52E-01

2.76E-02

1 10E-02

2.76E-02

SSL •neXa

•2 6eE-04

5.07E-0t

1 .9 IE*01

6.69E-0O

6 f 2 E - 0 2

5.S3E-03

6.',2E-02

•Fgrther

Action

[based on

SSL)7

YE.5

YE-S

YES

YE.5

YES YES YES

SSRG

msIKs

1 2 7 E . 0 0

2 .23E .02

I .91E.07

5 5 9 E . 0 6

6 7 2 E H 1 1

2.40E.C1

K . m - V

Further

Action

(based on

SSRGI?

YES

YES

NO

NO

YES

YES

NO

Scei inr io

Chemicals

(of Interest)

!,I-Di*icroeiliane • 17-

Dic t ibroet t i / iene

(tfansi

Ethylbenzene

S^/tene

Tfict i :oroe;hrlene

Vinyl c i tor id?

Naphthalene

3

Measured soil

coneen (Ct)

Imo.kol

1COE-02

9 5 0 E - 0 2

6 M E . 0 2

4.00E»02

J 33E-02

5 4SE.02

4 3 3 E . 0 2

Kd(VZ|

t-lKo

7 . 6 D E - C I

6.83E.0t

4 72E.O0

I 0 I E . 0 1

2 leE.oo

2 42E-Ct

2 IcE.fJO

KdtOWl

L K n

7.65E-0I

6 83E-01

4.72E-O0

1.01E-0I

2 . I 6 E - 0 0

2 - l 2E- i ! l

2.16E-0O

Retardation

^ - IRI

5 9 2 E . 0 0

5 3 8 E . 0 0

3 I3E .C1

S.SSE.Ol

149E.C1

2 55E. i ;0

t 4 6 E . i : n

Wean Travel

Time Thru

Vertical U y e r

T t i j ea r s l

1.66E-00

t .SIE-OO

e 7 7 E - 0 0

: . 84E-01

4 .16E-00

7 l S E - 0 t

4 16E-00

Cgw from Ct

(without

degrad)

mfl .1

I.71E.01

i.eeE-02

2 39E.01

7.03E-00

3.27E-C1

1 83E.'32

3 27E.0I

Cgw from C(

(with degrad)

mg'L

2 .11E-00

4 .21E-01 -

0

0

! . 8 4 E - 0 t

2 . 5 1 E - 0 I

1 05E-08

MCL or

PRO

( m a l l

4.40E-05

t.0OE.Cl

7.C0E.CI

I .MEAJI

5.IX)E-C3

2 00E-03

5.00EJ33

Caw

MCL

MCLG.

m f t l .

2 43c-04

5S2E. ( ) t

3 87E.0O

5 52E-01

2 76E.02

l . lOE-02

2 7f.E.02

SSL

m»'Kg

2.58E-()4

5 07E-I11

1.91E.0I

6 .«E-QC

6 62E-02

= S8E-0J

6 62E-02

•Fuitlier

Action

{based on

3SL)7

YES

YES

YES

YES

YES

YES

YES

SSRO

2 09E-03

2 2 6 E . 0 0

I .61E.07

S.eSE.Oo

I .1SE.0I

4.34E-02

i ; .62E.04

Further

Action

{based on

SSRGI?

YES

YES NO NO YES YES NO

31

AR304398

Aquifer Mixing Zone Depth and DAF Parameters

Variable L

K-

da

i

Qw

Pb

Pp

foe

Value 183

316

76 0.02

0.30

1.50

2.65

0.004

Unit m

m/yr

m

m/m

Unitless

kg/L

kg/L

Unitless

Descript ion Source length parallel to groundwater flow

Aquifer saturated horizontal hydraulic conductivity

Aquifer thickness

Horizontal hydraulic gradient in aquifer

Water-filled Porosity

Bulk Density

Particle density in aquifer'

Fraction of organic carbon in aquifer

Calculated parameters

O

©a

d(calc)

DAF d(in DAF)

0.43

0.13

26.0 4.7

26.0

Unitless

Unitless

m

unitless m

Aquifer porosity

Air-filled Porosity

Calculated Mixing Zone Depth Dilution Attenuation Factor Mixing Zone Used in DAF Calculations

AR304399

Scxirc* Layef

Vados« Zone Layer 1

Aqurlt^r Idyir

Ai*-,^i::!rr<.«of'=ricl fifoo^'r^es.' . .\

AR304400

Pro jec t Name:

Pro jec t L o c a t i o n :

P ro jec t Of f icer :

Date :

Chemicals

(of interest)

4,4-DDT .

2,4,5-T

2,4-D

2,4-DDD

2,4-DDE

2,4-DDT

4,4-DDD

4,4-DDE •

Aldrin

Alpha Chlordane

Alpha-HCH (alpha-BHC) .

Atrazine

Beta BHC

Chlordane (technical)

Delta BHC

Dieldrin

Diphenamid

Endrin Endrin Ketone .

gamma chlordane

gamma BHC(Undane) •

Heptachlor

Heptachor epoxide

Naphthalene

Toxaphene

* NE = Not evaluated

Central Chemical Hagerstown, MD Mitch Cron 3/5/2009

Measured

soi l

co i icen (Ct)

(mg/kg)

3.8PE+03

5.50E-02

9.60E-02

2 20E+02

1.60E+02

6 60E+02

5.90E+02

9.10E+01 •

2:20E+02

1.10E+01

4.30E+02

3.00E-01

9.20E+01

1.70E+02

3.60E+02

2 70E-01

1.80E+00

9.80E+01

4.90E+01

6.40E+02

2.10E+02

8.30E+01

1.80E+00

9.00E+01

'

Kd (VZ)

UKg

1.05E+04

2.56E-I-00

1.05E-01

8.96E+02

6.20E+02

6.20E+02

4.00E+03

'1.79E+04

9.80E+03

4.80E+02

4.92E+00

2.48E+00

5 04E+00

4 80E+02

7.60E+00

8.56E+01

8.16E-01

4.92E+01

212E+03

4.80E+02

4.28E+00

5.64E+03

3.33E+02

8.00E-I-00

1.03E+03

SOIL SCREENING & REMEDIATION GOALS (SSRG) Tool Vers ion: 2.0 (March, 2008)

Author: David M. Kargbo, PhD, USEPA Region III

SSL and SSRG RESULTS FOR ORGANIC CONTAMINANTS

Scenario 1

Kd(GW)

L/Kg -

1.05E+04

2.56E+00

1.05E-01

8.96E+02

6.20E+02

6.20E+02

4.00E+03

1.79E+04

9.80E+03

• 4.80E+02

4.92E+00

2.48E+00

5.04E+00

4.80E-I-02

7.60E+00

8.56E+01

8.16E-01

4.92E+01

2.12E+03

4.80E+02

4.28E+00

5.64E+03

333E-I-02

8.00E+00

1.03E+03

Retardation

(R)

7.40E+04

1.90E+01

1.74E+00

6.30E+03

4.36E+03

4.36E+03

281E+04

1.26E+05

6.89E+04

3.38E+03

3.56E+01

1.84E+01

3.65E+01

3.38E+03

5.45E+01

6.03E+02

6.74E-I-00

3.47E+02

1.49E-1-04

3.38E+03

3.11E-I-01

3.97E+04

234E+03

5.73E+01

7.23E+03

Mean Travel

Time Thru

i/ertical Laye

t t ( yea rs )

1.08E-1-05

2.77E+01

2.52E+00-

9.16E+03

634E+03

634E-t-03

4.09E-t-04

1.83E+05

1 .OOE-i-05

4.91E+03

5.17E+01

2.68E+01

• 5.30E+01

4.91E+03

7.91E+01

8.77E+02

9.80E-I-00

5.04E+02

2.17E+04

4.91 E+03

4.52E+01

5.77E+04

3.40E-t-03

8.32E+01

1.05E+04

Cgw from Ct

(without

r degrad)

mg/L

7.62E-02

4.20E-03

6.64E-02

5.18E-02

5.44E-02

2.24E-01

3.11 E-02

1.07E-03

4.73E-03

4.83E-03

1.77E+01

2.38E-02

3.70E+00

4.60E+00

8.85E-01

560E-02

7.68E-03.

.9.75E-03

2.15E-02

3.01E+01

7.85E-03

526E-02

4.63E-02

1.85E-02

'

Cgw from Ct

(with

degrad)

mg/L

0.

9.51 E-03

0

0

0

0

0

0

0

0

0

0

0

0

1.18E-03

0

0

0

0

0

0

0

0

MCL

or

PRG

(mg/L)

2.00E-04

3.70E-01

7.00E-02

2.80E-04

2.00E-04

2.00E-04

2.80E-04

2.00E-04

4.00E-06

1.90E-04

1.10E-05

2.90E-04

3.70E-05

1.90E-04--

4.20E-06

I.IOE-t-00

2.00E-03

2.00E-03

1.90E-04

6.10E-05

1.50E-05

7.40E-06

1.40E-04

6.10E-05

'

Cgw based on

MCL, MCLG,

rhg/L '

9.49E-04

1.75E+00

3.32E-01

1.33E-03

9.49E-04

9.49E-04

1.33E-03

9.49E-04

1.90E-05

9.01 E-04

5.22E-05

1.38E-03

1.75E-04

9.01 E-04

5.22E-05

1.99E-05

5.22E+00

9.49E-03

9.49E-03

9.01 E-04

2.89E-04

7.11E-05

3.51E-05

6.64E-04

2.89E-04

SSL

, mg/Kg 9.98E+00

4.85E+00

1.01E-01

1.19E+00

5.88E-01

5.88E-01

5.31 E+00

1.70E+01

1.86e-01

4.33E-01

2.67E-04

3.68E-03

9.19E-04

4.33E-01

4.07E-04

1.71 E-03

5.30E+00

4.69E-01

2.01E+01

4.33E-01

1.30E-03

4.01 E-01

1.17E-02

5.45E-03

2.97E-01

'Further : Action

(based on ' SSL)?

YES

NO

NO

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

NE

YES

• Y E S

- NO

YES

YES

YES

YES

YES

YES

YES

YES

SSRG

mg/Kg 9.98E+06

7.07E-01

1.19E+06

5.88E+05

5.88E+05

5.31 E+08

1.70E+07

1.86E+05

4.33E+05

2.67E+02

3 68E-I-03

919E+02

4.33E+05

4.07E+02

1.71 E+03

2.51E+02

4.69E+05

2.01E+07

4.33E+05

1.30E+03

4.01E+05

1.17E+04

5.45E+03

2.97E+05

'Further Action

(based on SSRG)?

NO

NO

NO

NO

NO

NO

NO

NO

NO

YES

NO

NO

NE

NO

NO

NO

NO

NO

NO

NO

NO

NO

NO

NO

AR304401

SOIL SCKEENING & KEMEblAtlON COALS (SSKG) Tool Version: 2.0 (March, 2008)

Author: David M. Kargbo, PhD, USEPA Region 11!

Project Name: Central Chemical . , Project Location: Hagerstown, MD Project Officer: Mitch Cron Date: 3/5/2009 ^

SSL and SSRG RESULTS FOR AfETA/. CONTAMINANTS

Scenario 1 Scenario 1

Chemicals

(of interest) Arsenic Manganese Thallium

•

Measured

soil

coneen (Ct)

(mg/kg) 4.07E+02 1.02E+03 4.10E+00

•

Kd(VZ)

L/Kg 3.90E+01 6.50E+01 7.10E+01

Kd(GW)

L/Kg 3.90E+01 6.50E+01

- 7.10E+01

•

Retardation

(R) 2.75E+02 4.58E+02 5.00E+02

Mean travel

Time Thru

Vertical Layer

Tt (years) 4.00E+02 6.66E+02 7.27E+02

.

Cgw from Ct

• (without

• degrad)

:, mg/L

•2.19E+00 3.30E+00

, 1.21 E-02

MCL

or

PRG

(mg/L) 1 .OOE-02 8.80E-01 2.00E-03

. -

Cgw based on

MCL, MCLG,

mg/L

4.74E-02 4.17E+00 9.49E-03

>

S3L mg/Kg 1.86E+00 2.72E+02 6.75E-01

•Further v-lActiori.-V'.; '{based oh

$:issL)?--:1v YES YES YES

NE = Not evaluated. Also not evaluated are SSRG and Further Action based on SSRG

AR304402