DATA RESULTS: SOIL SCREENING & … · Version: 2.0 (March, 2008) Author David M. Kargbo, PhD, USEPA...

SDMS DocID 2101262

Central Chemical Site Record of Decision - Operable Unit 1 September 17,2009

SSRG Tool for Soil Remediation Standards - protective of ground water

AR305183

SOIL SCREENING & REMEDIATION GOALS (8SRG) Tool

VADOSE ZONE PARAMETERS ENTRY FORMS Data entry for Scenario 1 ^

Vertical - Total lUlodeled Enter vertical Soil Type Hyd cond Exponential porosity

layer tfiickness Used Ks (m/y) Parameter, b nt (fraction)

Source Layer

Layer 1

Layer 2

Layer 3

Layer 4

0.8

0,5

0.5

0.5

0.2

Effective porosity

ne (fraction)

Moisture content

0w (fraction)

. Effective moisture content

0e (fraction)

Data entry for Scenario li

Dab

Add

Vertical ' Total Modeled Enter vertical Soil Type .Hyd cond Exponential porosity

layer thickness Used Ks (m/y) Parameter, b nt (fraction)

Source Layer 0,8 0,5

Layer 1 . 0.5

0.5

Effective porosity

. ne (fraction)

Moisture

content &M (fraction)

Effective

moisture content 0e (fraction)

1 1 1 1 1 1 1

1 1 1 1 1 1 .

Laver 2| 02 j j j | | | |

1 entry for Scenario III

Vertical Total Modeled Enter vertical Soil Type Hyd cond Exponential porosity

layer thickness Used Ks (m/y) Parameter, b nt (fraction)

Source Layer

0.8 0.5 0.5 0.5

• '

Effective porosity

ne (fraction)

Moisture content

0w (fraction)

Effective moisture content

0e (fraction)

1 I I 1 1 1 1

Layenl 02 j | 1 / 1 1 1 1

itional soil data entry Infiltration rate (m/yr)

0.24

Bulk density (kg/L)

1.5

Particle ' density (kg/L)

Frac. org carb (unitless)

2.65 0.004 1

on

'

AR305184

SOIL SCREENING & REMEDIATION GOALS (SSRG) Tool

Select 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(Lindane) Heptachlor Heptachor epoxide Naphthalene Toxaphene

Concentration in soil (Ct). (mg/kg)

Half Life

T„2 (Yrs)

Henry's Law Constant (H')

Dimensionless

Chemical . Solubility (8)

mg/L

Octanol-C Part Coeff Koc (L/Kg)

SELECT ORGANIC CHEMICALS AND ENTER PARAMETERS

130,000 0

0.1

0.0

2,300.0 120.0

39,000.0 10,000.0

920.0 3,100.0 2,000.0

3,100 2.300.0

240.0 120,000.0

750.0 670.0

1.7 0.9

98.0 2,000.0 1,700.0

840.0 83.0 85.0

140,000.0

* •

;

1.67E+01

9.00E-01 1.67E+01 1,67E+01 1.67E+01 1.67E+01

16.70 0.15 0.42

• 0.5 0.30 0.50 0.42

,0.09 2.37 1.76

14.00 . 14.00

0.42 0.29 0.12 0.12 0.05

14.00

'

^ •

0.0003

0.0000

0.0000

0.0007

0.0007

0.0000 0.0002 0.0009 0.0070 0.0352

4.35E-04 0.0000 0.0000 0.0020

. 0.0000 0.0006 0.0000 0.0003 0.0439 0.0532 0.0006 0.0447

^ 0.0004 0.0198 0.0002

003

278.00

680.00

0.14 0.14

0.09 0.09 0.12 0.18 0.06

2.00E+00 70.00

0.24 0.06 8.00 0.20

260.00 0.25 0.03 0.06 6.80 0.18 0.20

31.00 0.74

^

2630000.0

641.0

26.2

224000.0

155000.0

155000.0 1000000.0 4470000.0 2450000.0

120000.0 1.23E+03

619.0 1260.0

120000.0 1900.0

21400.0 204.0

12300.0 530000.0 120000.0

1070.0 1410000.0

83200.0 2000.0

257000.0

MCL or PRG (mg/L)

^

2.00E-04

3.70E-01

7.00E-02

2.80E-04

2.00E-04

2.OOE-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 1.10E-05 4.20E-06 1.10E+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

/

AR305185

SOIL SCREENING & REMEDIATION GOALS (SSRG) Tool

Chemical

(of interest)

Concentration in soil (Ct)

(mg/kg)

Half Life Ti,2 •

(Yrs)

Henry's Law Constant (H')

Dimensionless

Chemical Metal Solubility (S) . Distr Coeff

mg/L Kd(LyKg)

MCL or PRG (mg/L)

SELECTINORGANIC CHEMICALS AND ENTER PARAMETERS |

Arsenic Manganese Thallium •

407.0 1,020.0

4.1

)

• '

. •

39.0 65.0 71.0

,

1.00E-02 8.80E-01 2.00E-03

^

AR305186

Aquifer Mixing Zone Depth and DAF Parameters

Variable L K

da

i

©w

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

0

©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 MixingiZone Depth

bilution,Attenuation Factor Mixing Zone Used in DAF Calculations

AR305187

P r o j e c t N a m e :

P r o j e c t L o c a t i o n :

P r o j e c t O f f i c e r :

D a t e :

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(Lindane)

Heptachlor

Heptachor epoxide

Naphthalene

Toxaphene

* NE = Not evaluated

Central Chemica l

Hagers town, M D

Mitch Cron

9/17/2009

Measured

soi l

concen (Ct)

(mg/kg)

1.30E+05

5.50E-02

3.60E-02

2.30Et03

1.20E+02

3.90E+04

1.00E+04

9.20E-^02

3.10E+03

2.00E+03

3.10E-^03

230E+03

2.40E+02

1.20E+05

7.50E+02

6.70E+02

1.70E+00

8.60E-01

9.80E+01

2.00E+03

1.70E+03

840E+02

8.30E-^01

8.50E+01

1.40E+05

Kd(VZ)

U K g

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+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

3.33E+02

8.00E+00

1.03E+03

SOIL SCREENINe & REMEDIATION OOAU (S5R0) Tool Vers ion: 2.0 (March, 2008)

Author David M. Kargbo, PhD, USEPA Region III

SSL and SSRG RESULTS FOR ORGANIC CONTAMINANTS

Scenarios

Kd(GW)

U K g

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-fO0

5.04E+00

-4.80E+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

3.33E-^02

8.00E+00

1.03E+03

^

Retardation

(R) 9.42E+04

2.40E+01

1.94E+00

803E+03

5.55E+03

555E+03

358E+04

1.60E+05

8.78E+04

430E+03

4.51E-^01

2.32E+01

4.61E+01

4.30E-1-03

6.91E+01

7.68E+02

8.31E+00

442E+02

. 1.90E+04

4 30E+03

3.93E+01

5.05E+04

2.98E+03

7.27E+01

9.21 E+03

-

Mean Travel

T ime Thru

k/ertical Laye

Tt (years)

1.32E+04

3.34E+00

2.71 E-01

1.12E+03

7.75E+02'

7.75E+02

5.00E+03

224E+04

1.23E+04

6.0aE+02

6.29E+00

3.23E+00

6.44E+00

6.00E+02

9.64E+00

1.07E+02

1.16E+00

6.16E+01

2.65E+03

6 OOE+02

5.49E+00

7.05E+03

4.16E+C2

1.01E+C1

1.29E-^03

Cgw f rom Ct

(w i thout

degrad)

mg/L

2.61 E+00

420E-03

2.49E-02

5.41 E-01

4.08E-02

1 33E+01

5.27E-01

1.08E-02

6.67E-02

8.78E-01

1.28E+02

1.81E+02

9.66E+00

. 5.27E+01 ,

2.03E+01

1.65E+00

3.53E-01

3.67E-03

9.75E-03

8 78E-01

8.00E+01

314E-02

526E-02

2.19E+00

2.87E+01

Cgw f rom Ct

(with

degrad)

mg/L

0

2.02E-02

0

0

0

0

0

0

0

2.09E-02

1.03E-01

1.28E-03

0

0

0

2.23E-01

1.74E-04

0

0

1 61E-04

0

0

0

0

MCL

1 or .

PRG

(mg/L)

200E-04

370E-01

7.00E-02

280E-04

2.00E-04

2.OOE-04

2.80E-04

2.00E-04

400E-06

1 90E-04

1 10E-05

2.90E-04

3.70E-05

1.90E-04

1.10E-05

420E-06

1.10E+00

200E-03

200E-03

1.90E-04

6.10E-05

1.50E-05

7.40E-06

1.40E-04

6.10E-05

Cgw based on

MCL, MCLG,

mg/L 9.49E-04

1 75E+00-

332E-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

522E-^00

949E-03

9.49E-03

9 01 E-04

2.89E-04

7.11E-05

3.51 E-05

6.64E-04

• 2 89E-04

mg/kg 9.98E+00

4.85E+00

1.01 E-01

1.19E+00

5.88E-01

588E-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

469E-01

2 01E+01

4.33E-01

1.30E-03

4.01 E-01

1.17E-02

545E-03

2.97E-01

' 'Further Action

;|i; (based on SSL)?

YES

NO

NO

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

NO

YES '

YES

YES

YES

YES

YES

YES

YES

SSRG' mg/Kg 9.98E+06

1.25E-01

1.19E+06

588E+05

5.88E+05

5.31E+06

1.70E+07

1.86E+05

433E+05

1.63E+00

6.47E+00

6.91E+00

433E+05

4.07E+02

1.71E+03

8.37E+00

9.91E+00

2.01 E+07

4.33E+05

6.45E+02

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

YES

YES •

NO

YES

NO

NO

NO

NO

NO

YES

NO

NO

NO

NO

AR305188

'r

Project Name: Project Locat ion: Project Off icer: ' Date:

Chemicals

(of interest) Arsenic Manganese Thallium'

,

~"

* NE = Not evalua

—

Central Chemical Hagerstown, MD Mitch Cron 9/17/2009

Measured

soil

concen (Ct)

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

; ted. Also n(

Kd(VZ)

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

-

'

Dt evaluat

MIL $eitt£Nltl6 & l^m^lAmN 6AALS ( i iM) Yool Version: 2.0 (March, 2008)

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

Scenario 3

Kd(GW)

L/Kg 3.90E+01

, 6.50E+01 7.10E+01 •

,

• - - N

3d are SSRC

Retardation

(R) 3.50E+02 5.83E+02 6.37E+02

\

3 and Furthe

Mean Travel

Time Thru

Vertical Layer

Tt (years) 4.89E+01 8.14E+01 8.89E+01

-

-if Action base

Cgw from Ct

(without

degrad)

mg/L 2.19E+00 3.30E+00 1.21 E-02

d on SSRG

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

"

-•' ,•

SSL mg/Kg. 1.86E+00 2.72E+02 6.75E-01 "N

V

-

' • -

: >FurtK€(r Action

(based on SSL)? ;

YES YES

I YES

•

\

,.

AR305189

SOIL SCREENING & REMEDIATION

GOALS (SSRG) Tool Version 2.0

January, 2009

USER'S GUIDE &

TUTORIAL

by ^ David M. Kargbo, PhD

USEPA Region 3 Philadelphia, PA

AR305190

DISCLAIMER

The Soil Screening & Remediation Goals (SSRG) T,pol 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-is 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 of the SSRG Tool. In addition, any interpretation of the predictions of the SSRG Tool is the sole responsibility of the user. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

AR305191

ACKNOWLEDGEMENT

The SSRG Tool was reviewed by a distinguished group of technical experts. 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 (G WTSC) 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 Pollutants 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 of the software.

AR305192

Conten 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 , 20

5.1 The Problem 20

5.2 Data Requirements for SSRG Tool 20

5.3 SSL and SSRG Modeling Steps 21

AR305193

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


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

Fig. T-10: Groundwater Parameters Entry Forms 26

Fig. T-11: Chemical Parameters Entry Form 27

Fig. T-12: Scenarios 1-3 vadose zone parameters and calculated pore water velocities 28

Fig. T-13: A clear entry screen following the clicking of the "Clear & Select oil Type" button. 29

Fig. T-14: Data cells filled with default parameters, calculated Vs based on default parameters.29

AR305194

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-1: SSL and SSRG results for organic chemicals 31

AR305195

Acronyms and Symbols

Acronyms DAF: Dilution Attenuation Factor MCL: Maximum contaminant level M2: Mixing Zone i 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;

loc:

Cw

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

Koc: L: Lv:

ne: nt R: S: TYi-. 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 (lag/L) Aquifer thickness (m) ^ Fraction of soil organic carbon (unitless) Maximum allowable concentration in groundwater (|ig/L) Henry's Law Constant (unitless) Horizontal hydraulic gradient (m/m) Vertical infiltration rate through vadose zoneXm/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 of the aquifer (yr) Vertical pore water velocity through the specified soil layer (m/yr) Bulk density (kg/L) . Particle density (kg/L) Volumetric moisture content (Vwater/Vioiai) Effective moisture content (Vwater/Vtoiai) Source Zone air-filled soil porosity (Vair/Vtotal)-

AR305196

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 of the 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 screening 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 SSRG 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 remedial goal 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 of the 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 infiuence contaminant transport time and concentration.

AR305197

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 of the waste unit; and

iii. The maximum contaminant.concentrations in soil that will not exceed the maximum contaminant level (i.e.. Tap Water level 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: - ,

Dispersion is not incorporated into the vadose zone transport estimate, only equilibrium partitioning. -Dispersive mixing is assumed in the saturated zone (similar to the current SSL guidance). Transport time in the vadose zone is determined by Darcy's Law and represents mean flow. ^

iv. To simplify leaching estimate's, 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 USEPA 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 (K„c) 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. '

AR305198

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 Wafer Velocity (PWV) Module

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 entry for Scenario 1

Modeled layer

Sotirce La/e i

I j y e n

L>y«r S

| j y t r 3

I j y e r 4

Entsr Veracal

thct/ess

r

Sol Type UsEd

.VenfcjIHid cond

Ks.(nr.Vi Expcfienlial

PafaTie:er.b Tctal ptMOS ty nt (ffactcnj

EITeclirt pwosilv

ne(!raction)

;

(.ioislure eortem

a * (fracton:

Effective moi5lue content

Qe Ifrartai)


>Jodeted lave-

Source Layer

L i y e r 1

Enter Vertcal

IhtK/ess

-

Sol TvM ' U'.Ed

VerkalH-^d cond

Ks.fir.'vi Exponential Tctal poios !v

nt (ftachcn)

Effecive pcrtMttv

ne iffsclicn)

Uotsture content

3'A (fraction

Effecttve inorstu-e content

Qe (frarto)

l . l 1 1 1 1

l . l 1 1 ' 1 1 1 . . 1 • '.

L.y.r i l 1 1 1 1 , 1 1 1


Wodalcd laye-

Source La/e i

Enlsr Vertfca!

thickrea • Swl 1>1M

Uwd

Vertcal Hyd cond

KMrrM E<pcneib£l Pcra-n&tr. b

Total aorosity ' nl(fraclcnc

Effective porosity .

ne (Tactjo-i) 'f/oidutfe content

Qv (ffacton)

Efecjve mccture content

Qe (fra;l)cn}

/•

I I 1 1 1 1 U y . r l l 1 1 1 1 1 • 1 ' 1

Additional soil data entry

liifiltralion

.r.3to {iriiVr''

Bulk donstY(kq,'L)

Particle

dcrsilv 'kq/L)

-rac. orq carton funitloGC)

Fig. 1: Vadose Zone Parameters Entry Forms

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

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

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

10

AR305199

Hydrogeological parameters that are functions of the selected soil type are automatica;lly displayed when the soil type is selected; These include:

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

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

The code in the PWV module then uses the above parameters to calculate: the moisture content (0w); the effective moisture content (6e), and the vertical ppre water velocity (Vs) through the specific soil layer. ' ,

One of the strengths of the 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.

Scenar io 1 Scenar io 2

r:- ^ d

r / ( . iv j - i L M - i

•1 . AiCrAo' . f ' -v iwic . .>, f

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

Hydrogeologic parameter data entry is a unique feature of the SSRG model. Thcuser has the option of entering his/her own site specific data (Fig. 3 A) in USER-fNPUT worksheet or use SSRG's default hydrogeological characteristics (Ks, b, nt, and ne) in SCEN-INPUT worksheet. These default parameters are functions of the selected soil type and are automatically displayed with the calculated vadose zone parameters (6w, 6e,Vs) when the soil type is selected (Fig. 3B).

Ll

AR305200


Vtxif.teitl.ivei

Source Layer

I j y t r 1

• » i

O.S

f i ' : i . ;

S-Jir I'/Vt-

t.'fpj

Virtical H-«i

. a n d L^pcwntut 'ctalsofc-iiiy nl ifr.ic.licn|

pCftSif, nft f:rii{.t<;nj

WDshre . cunlen!

Cv> itra-Jliin)

=?feclivt} moisluT corJenl

(Jf firsitoi)

• 1 Sand

Sa r * L^aiii.

*(ii: J

m

i^

.V

0.44

o.^t.

yu>

1 <lilJ2

D.isy

• '5.25}

I.I.I56

02W 1

U v . r 2 | n j Hai t i . W J e 0,1S . CtC<' . . O.^w <^9K. 1

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


UDdslsd

Sourcs Layer

Entar • . •Bl iC3l

"tisanma

_ 06

0.5

Eiilsr Soil

Si:y

Soro

Soil Typs ir»Mi

varttcal

cona EjtponOTtu)

Paraiii«:8r, b

Tota pcroiiiy

ntifractionl

Ef(ocB-.> poroai})'

ns ifrictjom

Moisltira contsflt

ewffractioni

Sard cOW it!£ ' ,1 OCjV' j ^ o i r s ' '

Effftctr/»

qa rtractjoni

Ci5eulatM Vsniul port

W3»fv»)«a;y VB lm8;»t^^9a^

! -.££ -'' t

Layer 1

0 5

0.;.

Lmr; 53rO/

ux-n LcaiT: -S5 ' '. as 0 « 5 " c i i r ' i - 3: :o ' 113S

Laver 2 0 5 LO-iri LKrr, 15' 5 35 OiSS OiSi C i&5 S 267 0K5

Fig. 38: Default parameters as a function of the selected layer soil type.

Selection of the 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 of the source layer. However, to err on the side of health, the most permeable of the 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 noted 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 of the 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 of the contamination in the Source Layer to the top of the water table surface by the mean retarded pore water velocity using the following equatioris 1-5:

12

AR305201

Equation

Equation name

Equation #

Mean Travel Time

1

v = '

Soil-pore water velocity

2

n,

Effective moisture content

3

Volumetric moisture content

4

Retardation. coefficient

5

where

I uean

Lv V, R I e.v

lit

nt

b • K v

p?

Kd

mean navel time to the top of the aquifer (yrs) distance from the bottom of source layer to the water tnble (meter) pore- water velocir)' in the vadose zone (ineter/yeai) unsaturated retardation coefficient (unitless) verticil intiltiation rate through vadose zone (merer/year) vohinietric nioistiue content (\ vater/V',oii) (fraction) effective moisnire content (fiaction) , effective porosity (fraction) total pnmsiry (frnclion) soil-specific exponential parameter limitless) saturated'K parameter (raeier/year) soil hulk density (kg/T.) distribution coefficient of tlie chemical (Lk")

3.3 DAF/MZ Module

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

13

AR305202

GROUNDWATER PARAMETERS

Aquifer Mixing Zone Depth and DAF Parameters

Variable '

L K

Da ^

1 . '

0W

• Bb

3D

foo


0

•©a

d(calc)

DAF d(in DAF)

Value

122 334

183

0.025

0.30

•1.50

• 2.65

0.013

Unit m

m/yr

m i

IM/MI

Unitless

kq/L

kg/L

UniUess

Description Source lenath parallel to qroundwater tlov/ Aquifer saturated horizontal hydraulic conductivity

• Aquifer thickness

hoiizuiilal liyUiaulic giadieiit in aguitei

Water-filled Porosity

Bulk Density ' '

Particle density, in aqurer

Fraction of organic carbon in aauifer

0.43

0.13

16.5 5.5

16.5

Unitless

Unitless

m

unitless m

Aquifer poiosity

Air-filled Porosity

Calculated Mixinq Zone Depth

Cilution Attenuation Factor

Mixinq Zone Used in DAF.Calculations

Fig. 4: Groundwater parameters

3.4 Model Equations for the MZ/DAF Module i

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).

\0..5 r/ = (0,0112-Z7^r/,.(l-f"-^^':^''-')

where

K = saturated horizontal hydraulic conductivity in the aquifer (m/year) i = horizontal hydraulic gradient (m/m) I = 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.

14

AR305203

3.4.2 Dilution Attenuation Factor (DAF) Like the MZ calculation, the equation for the dilution attenuation factor (Equation 7) is the same equation used in the USEPA Soil Screening Guidance,

^ • L -. : . . . • . . . . . . . . : . . 7

where

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

3.5 Results Module

The result module is the most sophisticated component of the model. It evaluates five fijndamental logic criteria including: ' /

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

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

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

to determine whether further action is need at the site. -V. Comparison of the 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.

AR305204

Table 1: SSL and SSRG results for organic chemicals

1

Project rJame: S

Project Location

Project Officer: .J

Date:

Scenario 1

Chemical* Ic f ln t i res t )

i . | .Ci(r ,k;K>*are

EtTyiberzere

% i ( ! n t

hc i totMt^v iene

vn>i d l o f i * :

k y 5 h i w . e «

sRG Evaluation of ABC

Nowhere Towship

ofn Ltoe

3/18i20C8

MGKured to l l

M T O n l C i l K<I(V5

i a E . 0 2 7 f«E-5 l

OSCE'O; Sf.^r-C'l

6 5 ^ - O J 3 T i i - m

4 . 0 C E ^ ! I .J iS-CI

4.JJt*'.r.' ; ; . lo rHL i

SJiiE-C? 2 42E3 I

4 i : E . O : 2.ISS f i j

Soil Screening & Remediation Goals (SSRC

Version: 2 (Marcli. 2(I0S) Author Dff;id M. Karqto. FtiD.

. USEPA Region III .

s Site soils

S S L a n d S

man L'Xg

7 .»£4 ) l

• i .S3r-OI

4 ? 2 E - »

• ; i E - ) l

• n ' . t - j l l •

2 . t 2 : < i l

JICE.»

SRG RESU

Rebrd3«on

6,°8E-00

' 6 J 3 E - M

3.75E-01

? ? f E - S l

l . ' b t - l - ;

2.S?E-00

i . ' S E . ; :

•

LTSrORO

T I f M T h m

VerUoal b y v

T t i y e j K )

9.e5E.C0

S i i : > m

. S . l K ' C l

l.:9E.(2

:;.44"H1

J.!5E>(0 •

;.44=.(1

RCANIC CONTAMINANTS

Cgw t o r n Ct

|v«1*oul Cgwfron-.Ct

degrad) tvîth degi^d}

11161 W L

•:.71E-0-

18<E-32 .

2.J!E-0

7.IJ;E-M

• J 2 ' t - U '

; 3 ; E - 3 ;

3 ; - E . C ' '

! .C1E.«

3 i 3 E ^ »

c •

i;

1 ! 1= -W

j . - 7 E a j

c •

J) Tool

. M C L o r P R O

Ino 'L )

4 40E.Oi

KOE-Ol •

7C0E.0:

• ! COE-5'

iL'JCAJJ

2 COE 0^

5 (0E-D !

» U C l ,

MCLO. iTtd'L

2.43E.C4

5S2E<:r

3 « 7 E - « i

5 . ! 2 E J : 1

^ . ' 0 t 4 J i

I.10EC2

";.'GE-C2

SSL • i i iBKg

2 M E «

5 0 7 E J : I

I .5 ;E-OI

•;89E-00

cb2=.\.'z

5 98EM

• i : 2 = - : 2

• F u r f w ' -' ' A c t o n 3

I S a s J d o n -

•'.• 'SSU? ' • '

YES

•ES

• YES

VES

u y

Y:.5

YES

1

JP;:" f 5SR0

m » K l ! '

4.36E-01

; .59E-03

I.S-.E-07

5.65E-06

l . « . : - H )

3 44E-02

£ . 6 I E 0 4

. Furtw . A c t o n

( iHsedc

SSRQ)

YES

m NO

NO

i t j

• i t ?

no

Sceuni io

C h e m i o l i lof I n t H X t )

i |.OicWoroetia.-ie

•..2-

DkJikiroelh'/ lene

(t fansl

Et^->Î>en2ene•

Sfc-rene

I T rc - i lwo f lhy tene

Vinvl 'Z 'or:6e

1 NafMater?

2

r4e3«iiredso<l

conoeh (Ct)

( n * t ( l l

l . ( f3E-02

9 .50E-02

5 5 4 E . 0 2

4 OOE-02

• 4 .33E-02

5.46E-02

4.33E-C'2

Kd(V2 l

L X o

7 66E-0I

6 33E-01

4 7 2 E - J : O

101E-Q1

2 -.SE-X)

2 42S.01

2:,SE-00

Kd lOW L K d

7.66E.0I

S63E .01

4.72E-D0

1.CIE-01

2 . I 6 E - 0 0

2.42E.OI

2.I6E-30

Retardation

IRI

5 .35E.00

4 8 8 E . 0 0

2 . 7 8 E . 0 I

5 . 84E .0 I

I .33E.OI

• 2 .37E.0C

1 .33E.0 I

Mean Tmvel

t l m e r h m

Venioal U y e i

T l l y e ^ l

6 .75E-00

8 I 5 E - 0 0

• 3 . 5 1 E - 0 i

7 .35E-0 i

• . .67E.0)

2.99E-Otl

l . ;7E-3i

Cflwfroni CI

(V«ft(»llt

de j rad l

1 .7 iE-OI

. I.88E.'0S

2 .39E.01

7.03E.OO

3.27E-C1

l . 83E '02

.3 2 7 E . 0 I

Cow from Ct

(with degrad)

.n»'L

'3 .47E-03

4.25E-0I

0

0 .

3 2 2 E . 0 0

4 . 5 c E J 2

0

•

rdCLor '

PRO

( m f l l l

4.4OE.05

1 OOE-OI

7..30E.01

l.'3C=-01

5 00E4D3

2 OOE-03

£..3eE-03

Cgw •

based on

MCL,

MCLO.

m»-L

2.43E-CM

5.52E-01

3 87E-C0

5.52E.01

2.76E-02

i . lOE.05

2.76E.02

SSL 1 m s ' K f l y

2.58E-04

5C7E-01

l . 9 i E . i ) l

5.69E-00

6.e2E.02

5.68E.03

8.S2E-02

' ' 1

•Further

AoOon

(based en

6SL)? «..

VE.5

YES

YE.S

YE.5

YES

YES

VES

ssRa, * - m g H s ' 1

1 27E-013

2.23E-C2

1.91E-C7

5 . 6 9 E . M

6 72E-01

2 . 4 0 E . 0 I

S . W E - W

. F u r l h J r , ,

Act ion

(baeedon

SSRI2I7

YES

YES

NO

, NO

YES

YES

NO

I (

.Sceuniio

lof inteieU)

1 r. l -DicfJoroetr iane

; 2.

Dichk)-oelh;êne

i saas i

Elr i '^benzene

1 Sr j iene

1 T tKT ikywJ iv lene

Vinyl cr ior.de

1 Naphtf ialene

i

(Jeatured.o l l

concen (Ct)

(m t r t o l

I.OOE-02

S 5 0 E - i ) 2

S 5 4 E - 0 2

4.OOE-02

4 .33E.02

b 4 b E - 0 2

4 3 3 E - 3 2

Kd(VZ)

LK„ 1

7.56E4:>1,

9 . a j E - 0 l

4 .72E-00

1.0)E-01

2.I4E.O0

2.42E.CI

2 l6£.0a

KdlOVV) ,

UKo

7.65E-0)

6 .S3E4; i

4.72E-D0

l O I E - 0 1

2.ieE.»D

242E.C1

1 216E-00

Retardation

1 (Rl

5 92E.D0

5 . M E . O 0

3 . I3E .C1

6 5 3 E . 0 i

t 4 3 E . C i

2:w=.oo

I.45E-C1

Mean Travel

Time Thru

Vertioai Layer

Tt (years)

] 6 6 E - 0 0

t . o lE -O l )

a .77E-00

1.J4E-01

4 . 1 6 E - 0 0

7. !3E.C)

4 ISE-aO

Cf lwfrom Ct

(without

degrad)

m f l L

1.71E-0(

I.SSE.02

• 2.39E.01

7 03E-00

:27E-OI

1.835-0^2

3.27E.01

Cgw from Ct

(w l lhdegnd)

mgfL

2 i i E - C 0

J . 2 ! E - 0 I

0

0

l . 8 4 E - ; i

2 5 : E - 0 1

I.C5E-0S .•

MCLot

PRO

(msO.)

4.40E4;5

l . f O E J j l

7.tOEJ:'1

100E .OI

5.00E4J3

2.t«E.i33

5 .WE.03

Cgw

based on

I t C L

MCLO

m s L

2.43S-04

5 5 2 £ . 0 -

3 . 9 7 E - M

5.52E.01

2 7Ê.02

) 1 0 = 0 2

2 76E-02

mm LA SSL , ^ • . ' ' r i ^ ' ' t ^ : ' '

2.58E.04

5.07E-3I

I . 9 IE .C1

5 nSE-OC

6 6 2 E - 0 2

S.SdE-OJ

6.62E..92

:-;Further,.-

I A c t » n g

(based e n ^

w a S L ) ? * *

YES

VES

YES

YES

YES

YES

YES

SsSROg'

2 . 0 9 E J : 3

2 2 6 E - 0 0

I . 9 I E - 0 7

5 6 9 E - 0 6

1 . t9E4 ; i

4.34E4;2

e.«E-(M

4A is t ion .

( iMMdaiS

• SSROI?.-

YES

VE.S

NO •

M :

YES

YES

NO 1

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

16

AR305205

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

Scenario 1 Scenario 2

Scenario 3

TCE (433 mg/Kg)

SSL 6.62i;-02

6.62F,-()2

6.62F,-02

SSRG I.96E-00 6.72 E-01

1.I8E-0I

Vinyl Chloride (546 mg/Kg)

SSI., . 5.9X11-03.

5.98r.-03

5,98i:-03

SSRG 3.44E+02

2.40E+01 4.34E-02

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

SSI. . 5.07E-01

.5.07E-01

5.07E-0I

SSRG 2.69E+03

2.23E+02

2.26E+00

Ethylbenzene (654 mg/Kg)

SSI. 1.91 El 01

1.91E+01

1.9IE+0r

SSRG 1.91 E+07

1.91 E+07

1.91 E+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

Scenarios

TCE (433 mg/Kg)

SSL YES

YES

YES

SSRG YES

YES

YES

Vinyl Chloride (546 mg/Kg)

SSL YES

YES

YES

SSRG YES

YES

YES

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

SSL YES

YOS '

YES

SSRG NO

YES

YES

Ethylbenzene (654 mg/Kg)

SSL YES

YES

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 =1) 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 chernicals that volatilize but do not degrade, is Equation 8:

C C;-[lQOOtig^mg] ,

^/(DAF)

where

DAF = Dilution Attenuation Factor (unitless) Ci = total soil concentration (mg/kg) Cgw = concen. in groundwater at hypothetical well at edge of source area (|J,g/L) Kd = distribution coefficient (L/kg) H = Henry's Law Constant for volatile organics/mercury (unitless) 6w = source zone water-filled soil porosity (Vwaier/Vtotai) Oa = source zone air-filled soil porosity (VairA'ioiai) pp = soil bulk density (kg/L)

17

AR305206

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

A'. 0.

c gl f . /

Pl i ) -

fc .e -°*°-*'"-««' i ::5-) (Z).-lF)-[lOOOua/iug]

A'. + Pi

where

T'/: is the chemical's half life and the rest of the parameters are as previously defined.,

3.6.2 Derivation of the soil screening levels and decay adjusted soil screening levels The code currently calculates two types of SSLs for each ianalyte; 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.chertiical's half life. Equation 11 is the SSL equation for any metal analyte, excluding Hg:

MCL • DAF • A , + ^

SSL,, , = Pii }•

A-OmT^,,,^T,,,) [lOOOug.'ing]

.11 where

The parameters are as previously defined, The degradation half-life (TVz) 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:

MCL • DAF • j A" +

• ^ • ^ n 2 =

{e.,-H-oJ

Pa :.-^.mT,,

-.'[lOOOug/mg]

,12

.SSZ-i , = MCL • DAF • < K j + ^ + ^ ' ^" Pii

& ,1-0.(593 r,^^v

-/[lOOOug/ma] .13

AR305207

4.0 References

1. Kargbo, D.M. 2006.'Soil Screening and Remediatioii 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-96/018

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 -

AR305208

5.0 S S R G Tu to 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 of the 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 of the 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 arid groundwater. SoilScreen decided 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 (I, 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 (6e, 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 of the required groundwater parameters have already been generated by SoilScreen during the RI stage and were used in generating the SSLs. These include:

20

AR305209

i. Source length parallel to groundwater flow (L, m/y); ii. Aquifer saturated horizontal hydraulic conductivity (K, m/y);

iii. Aquifer thickness (da, m); iv. Horizontal hydraulic gradient in aquifer (i,.m/m); v. Water-filled Porosity (Gw, unitless);

vi. Aquifer bulk density (Pb, kg/L); vii. Aquifer particle density (Pp. kg/L); and .

viii. 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 of the 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 1 - 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-1), the company selected "Enable macros" as required by the SSRG software.

|«i-^sya;to^¥^'^-'-'""''""---s:--"• •• • - - ^ '' • • tS '^ Hi-- . ~

rr-^^'>*«!rW^Wi>«-rf)i.-3*iii*(vBriia>iiiS'r;r-sij.r.;.:.*'P!»

;.! __ •;^^'.^i..«*f-..

Fig. T-1: Excel security warning

COMMENT: The SSRG software contains four worksheets: USER-INPUT; SCEN-INPUT; SCEN-0RGAN1CS_RESULTS; and SCEN-METALS RESULTS worksheets.

21

AR305210

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.

• I , . . , . • _ .

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 of the 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 entry tor Scenario I

Msiclod loi'ci

. Source Laver

Leyert

L « y « t }

Uyw 3

L i ^ < f 4

Fnt«

thiiJmcia

-,

So;!T>w •

'

V^ral H>rf CCrfvd

Ksirr.S')

.

Exoort«ntal, PafOtrKlo 0

Total DWOfrV nti(;x«!crtf

Fftrt-.T!

DOWtV . content 0 * J(ftKJ)Mlj

. .COT MM

Onto en t ry tor Scenar io 2

u x i i k i teiH

Source Uyer

Lay i f i

•Emet Veratj; VjilT«>e

Used

Vertcal H>d cooJ.

Ksirrh) Exponents! Parsrrw'.a. b

Total pOfKit/ n' I fraction;

Eftclve pcresit .

ne iiarjxn)

tAsstue toBtent ,

Qv if[Bction)

EPerHi-e rroiflure coilent

1. 1 1 1 1 1 1 1 1 1 I I

' Lmr i i 1 1 1 1 1 1 1 (

Data ent ry for Scenar io 3

Mj i f cW Itfjei

Source Layer

Enter VefSc*

1

L i t ;

V;rbC0l H,xJ .;ond

< > ; i i M - Pdi(iitd<:t.b ToW porcsih •|l[ti*,'.lUl;

Ef*:clvc

0 * (bcnliiJii;.

t f k d r . t

Oe!li<ii;w.!

' •

1 1 1 _ 1 _.._ 1 . J 1

Liven 1 I • i 1 1 1 I 1 1

• Additional soti data einry inf i l l r-at iori

rate (rn'vr;

Bulk

3enoiiv{:(q'Lj

Pdrti'Je

density (kq/L)

FrQC. o ra c a r t w n

• iuniu«s}

' Fig. T-2: Vadose Zone Parameters Entry Forms

In the SW area of the 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

AR305211

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

i. Sand layer (Layer I), 2 ft (0.6 m) thick; ii. Loam soil layer (Layer 2), 2 ft (0.6 m) thick and below the Sand layer;

iii. Sandy Loam layer (Layer 3), 1 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 1 (Fig. T-3) in modeling site SSRGs. SoilScreen entered the vadose zone data for Scenario 1 in the appropriate data entry form (Fig. T-4).

.'^^Mlka:

i

"« % - \ Source Layer

n n ' ' VadcKe Zone Layer 1

h. K. Vadose Zone Layer 2

Vadose Zone Layer i

Vadoie Zone Liiyer A

r a r ' . " ' ' . , ™.%,. ,'f

All layer fAaterial Pfopefties: p^ f

Fig. T-3: Schematic of SCENARIO 1 contamination v 'ith only the source layer contaminated

Data emi7 tor Scenarl

Modeled layer

" Source Leyer

Layer 1

Layer 2

Layer 3

Layer 4

Q l Ente

Vmcal , lhir,kness

06

06

0.9

03

0.3

•Soil Tvoe Used

Silty C!3y •-

Sord

Loam

Sand\' Loam

Loam

VentMlHyd , c:nd

Ks iirJj) ,;

32 .

5000

800

790

800

Ewxinential ^Aromeief, b

9.9

i.2

5

3

6

Tola! ocfosiry nt (faction:.

0.48

0J4

0.45

0 45

0 45

EffMVS porcsitv

ne {'Vocicn;

0.42O

0.405

0.40O,

0.402

0 400

Mctslure content

Qft/lreclion)

0.3*1

0.180

0.2X

0.233

0 2,30

Eftecif/e moisture con'jnl

• Oe (fiacbc«)

0.340

•0156

0.210

0.210

0210

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

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

23

AR305212

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).

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


Modeled layer

• Source Layer

Layer 1

• Enter Vertical

Itiidtness

06 .

06

06 03

Sal Type Used

Vertical Hyd cond

Ks |n-.V) Exponential

Pj.'B.'neter, b Total pc*osity nt ffra^on)

Eflectp/e pcrosity

ne ffeacrjcr)

Moisture contanl

0 * (^actic^J

EIlecti>.fe moisture cailent

Ot (fr3Cfit-.nl

, Sand 5000 4,2 0 44 C.405 0.180 0,155

•

Sandy Loam 790 9 0.46 0,402 0 233 • 0 210 •

Layer 2 0,3 loam 600 6 0 45 C400 • 0,2K 0,210


In this scenario, the Source Layer is equivalent to the Source Layer (Silty Clay) plus Layer 1 (Sand) of SCENARIO 1. 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 of the 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 I in SCENARIO 2.

Finally, at the NE corner of the site, almost all the 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

AR305213

http://fr3Cfit-.nl

• ' - • * — - > .

i ( , 'JOufCeCi^»*i

kdcc* Z o n i i j y a r l

Aqi*';:i Li?£'

A\l i~i^ Vftffirlt^i>''"Tf' 1

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. •"


Modeled tavw

Source Layer

Enter Vertical

thictness

0,5

0.5

0,6

0.3

• SolTytK Used

Veilical H/i cond

Ks!ni.'v! E^cnent.'al i'arameler. b

Tolal poroaty nt il-acliati

Elleclire POfOSllV

ne ilractwn) Vtistuie content

Qwjlraclioni

Elfeclive rrclslu.'e content

Qcitracnoni

Sand 500C' 4,2 044 I O405 , 0160 0,155

•

Layer 1 | 0,3 Loam 800 0 45 0 40O 0 230 3 210 •


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 Infjltiatlon rate (m/yr)

0.25

• Bulk •

density (kq./L)

• 1 . 5

Particle density (kq/L)

2.65

Frac org carbon (unitless)

0.013

Fig. T-9: Additional soil data entry

25

AR305214

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

Groundwater Parameters Entry Form: In this form (Fig. T-10), 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 of the 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. . i

GROUNDWATER PARAMETERS • '

Aquifer Mixing Zone Dapth and DAF Parametsrs

Variable

L

k Da

1

0 ,

9b ,

So

l«


0

0= d(calcl

• DAF

• dlit iDAF]

Value

122 334

183.

0.025

0 30

-50

2.65

,0,0:3

Unit

in iT/yr

, ' n

nVin

Lnilles5

• kg?.

ka'-

Uniilesi

Desra-lptlon

Source lenqlh parallel b ]rounjwatef llav

Aqu.fei satuieted horzonlal hydraulic condujUviiy

Aquifer thickness

Horizontal tiydraulic qradient in aquifsr

Water-filled Poiosity' ' , ' ,

Bulk Density

Particle densi'.y in aquifer ' '

Fiadionoforganc;,-£rbon n aquifer

0.43

0.13

16.5

5.5 18.5

lii i l less

Unitless

n initless'

n

Aquifer porosity

Ai--filled Porosity

Calculated Mixinq Zone Depth

Diluiicn Altenustion Factor

Mixinq Zone l.lsed in DAF Calculations

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 of the 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

AR305215

dichloroethane; 1,2-dichloroethylene (trans); ethylbenzene; styrene; trichloroethylene; vinyl chloride; naphthalene; barium; cadmium; chromium VI; and mercury (Fig. T-11).

CHEMICAL PARAMETERS ENTRY FORM

S€l€Ct

cre-nicals

[ i f inte-ei:!

C6nc£c'r3:on

m-iiiic:^'

(ng-m

Hsf Lift

-« ;v^5j

Henri's La/;

ccn5;3r,:i:-n

D nsnsico'e:.-

Cte.^icai

SCiLJiilV 155

r<;.l

Octa-icl-C

Pan cceii

*3C iLiKCI

MCL

cr PRG

tn j .U

. ' , 1 SELECT ORGAHIC CHEMICALS AND EN 1 t K PARAMETERS

•>J-C'icflcro>ir5ne

',2-Dic.toro5lf.>!e,-« (trans)

Stvrsne

T.ncri(cro«Ti)'.6ne

vinyl cnoriH

to?r:n3ler5

•co.c

SJJ.C

654,0 iX'.O i'H.ii 54».,Ci 433.0

0^550

0.700 C.027 0.077

5.CC0 C.250 C.-32

1.0700

G..3a50 0 3230 C.J13D 0 4220 i.noo 0,4220

se.-i

52.5

563.0

775.0 166.0

ie.6 I6S.0

i . i C : « .

I.CCE-C-1

-.CCS-C'I

1.00EJ3t 5.00EJ)3

. 2.00E-C3 5.00E-C3

Chemioai

fof intsrest)

Concentration

in io i l fCt:

(mg^kfii

Ka . f l i f e

T,,-:

(Yrs)

He.trv's Law

Constant (H'l

: Dsnensionltss

Chemfca! Meial Sciubil^iy

• Sj Ois;rCceff

mg/L Kef L/Kg)

MCL

or PRG

. f rr.gr Ll

1 SELECT IMORGAMIC C H E M I C A L S A N D ENTER P A R A M E T E R S

Bar ium Cadmium Chronhiuni •.I Mercury

12,343.0 234.0

7,367.0 676.0 0.467

A].Q

75.0 19.0 E.2.0

2.6aE-01 ».&aE-03

5.50E+00 1.00E+00

Fig. T-11: 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-INPUT Worksheet to find all the data entered in the USER-INPUT worksheet displayed in the appropriate cells

r of the SCEN-INPUT worksheet. The company is interested, in seeing how the default data compares with the site specific data.

COMMENTr'AII data entered in the USER-INPUT Worksheet gets displayed.in the SCEN-INPUT Worksheet (Fig. T-12). 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

AR305216

http://rr.gr

Ha<Hled En-Jif

V(>f«C4l i l t k i u *

Ertor S<:IITn» U*ad

Vertteit Iryrfeoic X* (m/f)

EipcntnTliI PirirmAff. b

Toi i l .pom.tty

r t (ft»ellont

Effective par««lty -

ne.fr.ctlon)

Moittuie eai tsr t

Ow (fr«Uo-i)

Eir«Cl:Vt moltture cortont

OB .FncUoni

CtJeu ated V«rtl:al po-e w»tar vslaclty

V» (TMltrf/nJr)

Sourca LavBi ' -J.i

L a y . i 1

Layer 2

n i i

O i j

Laver 3 ,13

Layer 4 ?3

C l a / 32 " 1 9 0 48C 0 423 D390 0 340 - 0 7.13 ' ^ ~ '

. - S a n d

Loa fn

- 6 0 0 0 ^ ,

* , 9 C 0 ^ .

1 ' J i

, ' '< a

0 41C -

0 45C

>.O405

• 0 40D

, .D 180

* 'D230

0 155

0 210

/ f 1 5 M .

1.223 r.'> Ji

! > « n d /

L o a m T'^O - 9 o isr 0 402 J 233 0 210 ' , 1 2J1 •

L o a m sro 9 (i4sr 0400 3 230 0210 1 223

. Clear & IMPORT USER INPUT data Clear & Select SoilType

Ill0<l«l>ll K y r

S o u r c e L a y e r

Enui vmllci l

thlckn«st

• 0 ,6

0,3

Enttr Sdl

Tvp.

Soil Typ. Uisd

VSaiH'

Vertlctl Byd

C9K4

• • •MOO'^

Eifuvuntlal , Piram«t»f, b '

•f^SWW

ToUl pofasjty

rtlfmellMil

" • ' O:A4O''S

EBedive p s m i t y

n i t f r iet tw]

SOM'!^"

MolHuie eonliirt

Qw (fritt len)

• • • f tTso ' " '

efkcUn mNttumcemtwl

Qelfraetlofll

0 166' .;,

VBticalptre wt1*f vulMlty VstmtlM^ev)

i;iiii^72«5?

[jyai 1

o,a

0,3

Sandy '

Lui i i i -790 0,450 0.402 0.253 , 0210 0,913-

Layer 2 I 0,3 • l!cam I 0450 0.400 • 0 230 , . 0210 • i-"-'^:i:o7o^

Clear & IMPORT USER rjPUT data Clear* Select Soil Type

Modeled

• l<ycr

Sourca Layer

Emer

> ; r t cd

tti icKndu

0.6 0.6 0,6 n.'i

E r t e

Soil type

Type

JJKl

IfSiirGi'

Vtrtlca:-

Hyd cond

p^mn-::

Ejp«nentul

Psrameier b

'S'My.^

real

pereeity

nT|'ri;tion;

..••tidoai

EfeclKe

putiity

m

imaioii

aniiinsj^

UcUtuie

conlert

Q*|(ri«or|

>.¥o:i8ii;;^'-

mcietun cairsni

dc l t r i c l io i i l

• 0 ;5S

iTi lcu i te i l

V4rtc:J part

w i t r velocity

VsimcurJiciri

i i ? 7 . : .

Layer 1 I lj,3 ' LcarniM.^;i)iM^|lgI§S^4'-iO/isCK?^V' t).400^:'-Nl%i30'--':i'.- 0.21J.' ; i .o?o; .

Clears, IMPORT USER NPUT data Clear & Select Soli Type

Fig. T-12: 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-FNPUT 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 for the soil layers encountered at the site, the SoilScreen modeler clicked the button "Clear & Select Soil Type" which displayed the following (Fig. T-13) empty data screen.

28

AR305217

DEF.aULT PARAMETERS FOR EACH SOIL TYPE

U c d i t d

Scurce Lr/er

Enter veic'c:!

tbicttnets

C.l

Lryert C.6

' Lj-,e,J C.5

U y e r : C :

L r , e r i c,:.

Enter Sori

Soil Tvw Used

f i ' '

:iyd a n d f t

i r i y ;

ExpotfntsI

\

portsrty n!

i , V ;

EFfe«vr poccMCy

ne

Hoislurt. conwrt

moistuiv eonlert

ae

*

Calsi lKH Vcrtio¥l ^9r«

WBtr ^locity

(mneiiyeaf)

1 1 1 ..• 1 . 1 • 1 1 . f ' • •

.. . - . • -•,.

• •• 1 1 1 - 1 ' 1 1 1

Fig. T-13: A clear entry screen following the clicking of the "Clear & Select oil Type" button •

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

The following should be noted: -

i. The "DEFAULT PARAMETERS FOR EACH SOIL TYPE" statement is displayed on the top of the data eritry screen to indicate any selected soil type from the drop down list will display default values.

ii( 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,

iii. 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-14:

DEFAULT PARAIWETERS FOR EACH SOIL TYPE •

Medeled

tiycr

Scurce -,. L*5er

v'. E;T>ler

vrrtcal

thiGlin«s

C.5

L^e r 1 C,5

Li'yer2 C.5

l i-rer S C ;

Liver 4 ^

Enter Seil Tror

Cle.

Sr.-:

I.CfT.

Se-tv LcB"-.

LCB!-.

Soil Type Usnl

=•,• S t . Cl.y

Verliiai rt,d » n d Ks

1mry^

2 i i i

Etponenlsal ?ar3ffle<^^,

, b

& \ K.: \ :

Total poretity

n: ifriKionr

.f vJTs':;

Effeccve pcfc-sic/

ne ilrsiioor'l

K.S,.i:;-';-

Moisture cont-ent

•frjslloni

: , !S4 '

Effective moi&LLrc content

Oe (Ir jKionj

' • * i } ^ e '

, CslEiitetiJ yenieal cwr^

• t n t t i velocit/

|mrtcr.'ifear}

' >.:Si:, •,•• U H • 6ow;-? V. iZ i ^ . fS B.,0407 .:. W 1 7 . . . . 3.171; • 0 - 8 ;. ••• i.4eT.-

.i-'.sn U - r , ;.'9- . - • v J ! 3 • • . - 3 J ; 4 : K £ •3.::f .• ,; ; g7 :•. J i J 5 .•

•iiem •55 ''. i i ' ' , v4S3 .>: '• D.J15S-' -3.:-i2' - -.•^i'ri'isc-^? 1,i;5 J i i i

'iv-em "•"•'i7 ^ '" •• 5 .SUV,:-. . •C.«J-.V • O J M f " : • : : ' '•• 0 :57 c.y ^ • , ^ 9 : 2 5 - .

Fig. T-14: 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 caii be repeated for each Scenario. ,

29

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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 opened the SCEN-ORGANIC_RESyLTS worksheet to review and print the results of their modeling exercises.

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 of the chemicals. Only SSLs are generated and will therefore not be featured in the tutorial. This is consistent with the USEPA guidance on SSLs. • '

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

I

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 / of the site represented by Scenario 1. The chemicals 1,1-Dichloroethane,

Trichloroethylene, and Vinyl chloride require some further action. As 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

AR305219

Table T-1: SSL and SSRG results for organic chemicals

Project Name: SSRG Evaluaac Project Location' Ncwtet^ l o Project Officer: John Ctoe Date i18,'2Da8

Scenario 1

Moacercdcoll Cbemcalt concen tCt'j |i>(lnUrMl) (mslrjl

I,14:'.;i-k:rc5th3ie ; IXE.02 l,2C-crtcffi£t^:/en« Itrani! 9 K t * ^ J .

ElhJb.;rMr? 6 51E-C2

•Slyienc J OOE'C?

T,ic*a»Ihv1«n* <o!E'02:

V. - r ) *Of i * i M i ' l i

Nart-i-tvi^v. j.i.'.F+i::- ••

•

not ABC WSllIB

KdlVO LKo

' 7 6iEOl

.b.BJt.^'

i.r;£-ci:i

l . j l r - i l

i.i?E-i:o

2,42E*

? if=.rf i

Soil Screening & Remediation Goals (SSRG) Tool

Vers ion : : (tyiarcti, 2008) Aulhot.Dai/idM.Kaigbo, PhD ,

USEPA Region III

s see soils

S S L a n d S

KdtOWl LKfl

7,6f,=j:i

r.bit.Vi

1 ? ; •£ -»

1 CIE-Ol

2 leEi i i

;-,4:E-CI

J l iF-ni

SRG RESU

Ret3nl:d4on

t«E-0O

t:,^h-y.i

176E-C1

7,SSE-0l

i,76E-:-i

• 2SE< l l

• Tff..'-

LTS FOR 0

rriean TiTlvtl

T ine Thru

Vertical Layer

Ttlveml

5,5s=-:<i

i i ^ - ^ i ; ,18:>01

I, :«E.02

2,J4E«:il

J i5E.OO

.; i4-Hii

RG/IWC c o ^

Cgwr ron Cl

(Mdiajt d«gr3d)

••71E-D1

• , « b - i ' Z

2 S E - 0 1

• 7 , ( 1 3 E - D :

. 3,27E-31

- , « 3 E - H

-177F--.1

TAMINAMTS

Cgwr rcn iC t

:wllhdegr.id)

, m g ( L

I,C1E.M

J ^ t V J

C

0

ll lE'OC

3 17E01

,-

MCL Of PRO Cnfl-L) .

• 41CE03

•:Xi:-.'I

7XE.31

:,KE.Dl

5 BE Do

2.KE 33

sS-F.I.- i

C j v ,

based

0.1 MCU

IKLtt. met

2 43.E.34

ot. ' t-Jl

3 87E«>;

5;:'E.)i

2 J5E-)2

1 lOE-K

7 7; F-12

.119 Kg

2 M E «

5Li/b^;i

1 3iE-31

5i9E-00

o62E-:2

'.•iitJ-.i

?.f 7F.r,y

1

•FdrtherS ,A^, -ntv

Ibowdsn . 55L|7.'

VES

rt.^

YE-S

'ES

• "ES

•-ES

VCR

'

1

; Furtbef

• . .Ao l ien

SJRS 'Onsedo r t

i T f K a 6SR0)?

J M E ' C l VE5

2,bt=-i.:) NO

t , 9 !E - t 7 .NO

; .HE-C6 • NO

l ,«E-r . l ] VEF

i,«4E-C2 YE.;

=.^;F-rj , NO

S c e i i R i i o

Chemical (el Interesll

i l-DicMcriKinane 1.2-Dichto-oettiyiene iliansi

Elnylbenzene

Srrreiw

Tt^cnlo.'M'hylene

Vtnvl c i orde

Naphthalene

2

coiwen (Ct) tnWkBl

1 l>3E.02

' 9,50E.02

6.aJE»02

4,l»E-02

4 , 3 J E - 0 2

5,45E-02

.4,33E-02

Kd(VZ) L'Kg

7 66E-01

8ME-01

4,72E-00

lOiE-Ol

2 li5E-W

• 2 45E-01

2 16E-i»

KdlGWi UKlI

7 6oE-CI

6,a3E.Cl

4,72E.O0

i.OlE-01

2,16E-OC

2,42E-lll

2,16E-'J0

Relanbtlm IRI

5,35E-0C

4,88E-0'j

2,7BE-01

5.ME-01

1.33E-01

2,37E-0';

•1,33E-01

Mejn Travel TrmeThru

Vertical Uyer Tl (years)

8,75E-(30

D,t5E-Kl

3 ,51E-0- -

r,35E-o-.

1.67E-3-

2,S!iE-M

l,67E-0:

Ct lwr rwn Ct

(wHhotit

degrad)

mft ' l .

l,7iE-CI

1 38E.C2

2 39E.01

7 03E.M

3 27E.C1

1 B3E.C2

3 27E-01

CBVjlromCt (with depad)

moL

3,47E-03

4,25E-01

0

0

3 22E-n(J

4E6E-02 •

0

M a e r PRG

(n«l.T.)

4,4CE-05

' 1,CCE-01

7,0CE-01

I,00E-Ci1

S.OOE-03

2 OOE-03

6,'3CE-03

C,« based on

MCL MCLG, mg.l

2 43E-04

5 52E.01

367E»00

5 52E.OI

2,76E.02

1, IDE-02

2,7eE.02

SSL

2 53E-*;

5.07E-01

1 91E-0I

5 63E-CC

6,6/E-Cl2

5,ME-M

6,62E-02

- - i ^

' F u l h e r ^

Action ;

(baeed o n ^

SiUl iKB

YES

VES

YES

YES

YES

YES

YES

SSRG

1.27E-0i ;

2 ,23E .02

1.91E.07

5 .e9E.06

6 72E.01

2 ,40E .C l

e S 2 E . 0 J

Further

Act ion

(based on

5 5 R C ) 1 -

VES

YES

NO

NO

YES

YES

NO-

Scenario

Chemicate

(of Interest;

' l-Dicl:lr.roetnane 12-Dichlo'oethylene (Udnsi

Errivltwnz(?ne ,

Sryrerw

T,":c".ioroe.:hv'lene •

Vinvl c?i:or-de

Naphlhalene

Measured soil

ooncm (Ct)

(mft'kgi

ymi'Oi

9 50E-02,

S i tE-02

4,lXIE-02

4,:'3E-02

5 45E-02

4,35E-02

Kd(VZ) L.Kg

7,SoE-0|-

6,83E-01

4,72E.30

1,0IE».3:

2,ieE-«i-2.42E-01

2.I6E-30

KdtOWl " LKg

7,5f,E.0l

6,B3E-01

4.72E-IW

1,(1IE-01

2,16E.OO

2 42E-01

2 16E-M

Retartlatjon IRI

5.92E-1JO

5 3 8 E ^

3 13E.0i

eseE.oi UPE. i l !

2.55E.00

t 45E.0i

Mean Travel TInwThnr

Verticil Layer Tl (years)

•„66E-03

-..SIE-OO

8 77E-D0

-, 84E-0:

4 l6E-a3

7,;SE.01

4,16E-M

, Cgw (rom Ct (without degrad) mffL i

1,7>E-C1 •

1,S8E.C2

2.39E.C1

7,03E-CO •

3 27E-C1

1 93E.C2.

3 27E.C1

Cgw from Ct (v/ith depadi

2,! IE-CO

i,21E-01

Cl

0

1 84E-01

2,51E-C1

• 105S-0B

M a e r PRO

(m»l)

4,40E-05

1,ClOE-01

7,00E.01

I00E-C1

5i )0E-O3

, 2 M E . 0 3 •

• ' j CinE-03

Cgw

based cn

M C L

M C L a

2 43E-34

5 52E-0'.

3 e7E-M.

5.52E-31

• 2.76E-32

1 lCE-02

2 76E-32

3SL moKa

2 58E-M

5.07E.O1

ig iE . iJ I

5,59E.OO

6 62E-a2

5 5eE-Ci3

e«E-Ci2

•Fu t thor '

Act ion.

[bosedon

8SL)7

YES

YES

YES

YES

VES

YES

. Y E S

SSRO' maKs

2.09E-(13

2.26E>M

IStE.07

6,6SE-05

1,18E-«1

4 34E-02

6 6 2 E . 0 4

F > ^ l . -ActioAt (based « v

35BO)?.«

YES

YES

NO

NO

YES

YES

NO

31

AR305220

DATA RESULTS: SOIL SCREENING & … · Version: 2.0 (March, 2008) Author David M. Kargbo, PhD, USEPA...

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Transcript of DATA RESULTS: SOIL SCREENING & … · Version: 2.0 (March, 2008) Author David M. Kargbo, PhD, USEPA...