United Stales
Environmental Protection
Agency
&EPA EPA's Composite Model
United Slatts •
for Leachate Migration
with Transformation
Products (EPACMTP)
Parameters/Data
Background Document
April 2003
-------
Office of Solid Waste (5305W)
Washington, DC 20460
EPA530-R-03-003
April 2003
www.epa.gov/osw
-------
ERA'S COMPOSITE MODEL FOR LEACHATE MIGRATION
WITH TRANSFORMATION PRODUCTS (EPACMTP)
PARAMETERS/DATA BACKGROUND DOCUMENT
U.S. Environmental Protection Agency
Office of Solid Waste
Washington, DC 20460
April 2003
-------
This page intentionally left blank.
-------
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS viii
LIST OF SYMBOLS AND ABBREVIATIONS ix
1.0 INTRODUCTION 1-1
2.0 WASTE MANAGEMENT UNIT (SOURCE) PARAMETERS 2-1
2.1 SOURCE PARAMETERS 2-4
2.2 DATA SOURCES FOR WMU PARAMETERS 2-4
2.3 LANDFILLS 2-10
2.3.1 Landfill Area (Aw) 2-10
2.3.2 Landfill Depth (DLF) 2-11
2.3.3 Landfill Base Depth below Grade (dBG) 2-12
2.3.4 Waste Fraction (Fh) 2-14
2.3.5 Waste Volume (PWS) 2-14
2.3.6 Leaching Duration (tp) 2-15
2.4 SURFACE IMPOUNDMENTS 2-16
2.4.1 Surface Impoundment Area (Aw) 2-17
2.4.2 Surface Impoundment Ponding Depth (Hp) 2-18
2.4.3 Surface Impoundment Total Thickness of Sediment (Ds) 2-19
2.4.4 Surface Impoundment Liner Thickness (D,in) 2-20
2.4.5 Surface Impoundment Liner Conductivity (K,in) 2-21
2.4.6 Surface Impoundment Base Depth Below Grade (dBG) . . 2-22
2.4.7 Surface Impoundment Leak Density (p,eak) 2-23
2.4.8 Distance to Nearest Surface Water Body (RJ 2-24
2.4.9 Surface Impoundment Leaching Duration (tp) 2-25
2.5 WASTE PILES 2-26
2.5.1 Waste Pile Area (Aw) 2-27
2.5.2 Waste Pile Leaching Duration (tp) 2-28
2.5.3 Waste Pile Base Depth below Grade (dBG) 2-28
2.6 LAND APPLICATION UNITS 2-29
2.6.1 Land Application Unit Area (Aw) 2-29
2.6.2 Land Application Unit Leaching Duration (tp) 2-30
3.0 WASTE AND CONSTITUENT PARAMETERS 3-1
3.1 WASTE AND CONSTITUENT PARAMETERS 3-2
3.2 WASTE CHARACTERISTICS 3-3
3.2.1 Waste Density (phw) 3-3
3.2.2 Concentration of Constituent in the Waste (Cw) 3-5
3.2.3 Concentration of Constituent in the Leachate (CL) 3-5
3.3 CONSTITUENT PHYSICAL AND CHEMICAL
CHARACTERISTICS 3-7
3.3.1 All Constituents 3-7
3.3.1.1 Molecular Diffusion Coefficient (DJ 3-8
3.3.1.2 Drinking Water Standard (DWS) 3-8
3.3.1.3 Molecular Weight (MW) 3-9
-------
TABLE OF CONTENTS (continued)
Page
3.3.2 Organic Constituents 3-10
3.3.2.1 Organic Carbon Partition Coefficient (koc) ... 3-10
3.3.2.2 Parameters Related to Chemical Hydrolysis . 3-12
3.3.2.2.1 Dissolved Phase Hydrolysis
Decay Rate (A,) 3-13
3.3.2.2.2 Sorbed Phase Hydrolysis
Decay Rate (A2) 3-14
3.3.2.2.3 Acid-Catalyzed Hydrolysis Rate
Constant (K/O 3-14
3.3.2.2.4 Neutral Hydrolysis Rate
Constant (K^r) 3-16
3.3.2.2.5 Base-Catalyzed Hydrolysis Rate
Constant (K*) 3-17
3.3.2.2.6 Reference Temperature (Tr) 3-17
3.3.2.3 Parameters Related to Hydrolysis
Transformation Products 3-18
3.3.2.3.1 Daughter Species Number (£) 3-18
3.3.2.3.2 Number of Immediate Parents (M() .. 3-19
3.3.2.3.3 Species Number(s) of Immediate
Parent(s) (m,(i), i = 1, M.) 3-20
3.3.2.3.4 Fraction of the Parent Species (^J . . 3-21
3.3.3 Metals 3-22
3.3.3.1 Empirical Kd Data 3-23
3.3.3.1.1 Kd Data Compiled from a
Literature Survey 3-23
3.3.3.1.2 pH-based Isotherms 3-24
3.3.3.2 MINTEQA2-Derived Sorption Isotherm Data . 3-25
3.3.3.2.1 Metal Identification Number (ID) .... 3-27
3.3.3.2.2 Soil and Aquifer pH (pH) 3-29
3.3.3.2.3 Iron-Hydroxide Content (FeOx) 3-30
3.3.3.2.4 Leachate Organic Matter (LOM) 3-31
3.3.3.2.5 Percent Organic Matter (%OM) 3-32
3.3.3.2.6 Fraction Organic Carbon (foc) 3-34
3.3.3.2.7 Ground-water Type (IGWT) 3-35
4.0 INFILTRATION AND RECHARGE PARAMETERS 4-1
4.1 INFILTRATION AND RECHARGE PARAMETERS 4-1
4.2 CLIMATE CENTER INDEX (ICLR) 4-2
4.3 INFILTRATION RATES 4-6
4.3.1 Landfill Infiltration Rate (I) 4-7
4.3.2 Waste Pile Infiltration Rate (I) 4-9
4.3.3 Land Application Unit Infiltration Rate (I) 4-11
4.3.4 Surface Impoundment Infiltration Rate (I) 4-13
4.4 RECHARGE RATE (IR) 4-15
-------
TABLE OF CONTENTS (continued)
Page
5.0 HYDROGEOLOGICAL PARAMETERS 5-1
5.1 HYDROGEOLOGICAL PARAMETERS 5-2
5.2 UNSATURATED ZONE PARAMETERS 5-2
5.2.1 Unsaturated Zone Thickness (Du) 5-2
5.2.2 Soil Type (ISTYPE) 5-6
5.2.3 Soil Hydraulic Characteristics 5-7
5.2.3.1 Soil Hydraulic Conductivity (Ks) 5-7
5.2.3.2 Alpha (a) 5-11
5.2.3.3 Beta (P) 5-12
5.2.3.4 Residual Water Content (0r) 5-13
5.2.3.5 Saturated Water Content (9S) 5-15
5.2.3.6 Soil Bulk Density (pb) 5-16
5.2.3.7 Percent Organic Matter (%OM) 5-17
5.2.4 Unsaturated Zone Dispersivity (aLu) 5-19
5.2.5 Freundlich Adsorption Isotherm Parameters 5-21
5.2.5.1 Leading Coefficient of Freundlich Isotherm for
Unsaturated Zone (Kd) 5-23
5.2.5.2 Exponent of Freundlich Isotherm for
Unsaturated Zone (n) 5-24
5.2.6 Chemical Degradation Rate Coefficient for
Unsaturated Zone (Acu) 5-25
5.2.7 Biodegradation Rate Coefficient for Unsaturated
Zone (Abu) 5-26
5.2.8 Soil Temperature (T) 5-26
5.2.9 Soil pH (pH) 5-28
5.3 SATURATED ZONE PARAMETERS 5-29
5.3.1 Particle Diameter (d) 5-29
5.3.2 Porosity ($) 5-31
5.3.3 Bulk Density (pb) 5-33
5.3.4 Aquifer Characteristics 5-35
5.3.4.1 Methodology 5-38
5.3.4.2 Hydrogeologic Environment (IGWR) 5-39
5.3.4.3 Saturated Zone Thickness (B) 5-43
5.3.4.4 Hydraulic Conductivity (K) 5-45
5.3.4.5 Regional Hydraulic Gradient (r) 5-47
5.3.5 Seepage Velocity (Vx) 5-49
5.3.6 Anisotropy Ratio (Ar) 5-51
5.3.7 Retardation Coefficient for the Saturated Zone (Rs) .... 5-52
5.3.8 Dispersivity 5-53
5.3.8.1 Longitudinal Dispersivity (aL) 5-54
5.3.8.2 Horizontal Transverse Dispersivity (aT) 5-56
5.3.8.3 Vertical Dispersivity (av) 5-58
5.3.9 Aquifer Temperature (T) 5-59
5.3.10 Ground-water pH (pH) 5-61
5.3.11 Fractional Organic Carbon Content (/£) 5-63
-------
TABLE OF CONTENTS (continued)
Page
5.3.12 Leading Coefficient of Freundlich Isotherm for
Saturated Zone (Kds) 5-64
5.3.13 Exponent of Freundlich Isotherm for Saturated Zone (rf) 5-66
5.3.14 Chemical Degradation Rate Coefficient for
Saturated Zone (\sc) 5-67
5.3.15 Biodegradation Rate Coefficient for Saturated Zone (\£) 5-68
6.0 RECEPTOR WELL PARAMETERS 6-1
6.1 RECEPTOR WELL PARAMETERS 6-1
6.2 RADIAL DISTANCE TO RECEPTOR WELL (R J 6-4
6.3 ANGLE OF WELL OFF OF PLUME CENTERLINE (9J 6-5
6.4 DOWN-GRADIENT DISTANCE TO RECEPTOR WELL (xj ... 6-6
6.5 WELL DISTANCE FROM PLUME CENTERLINE (yj 6-8
6.6 DEPTH OF INTAKE POINT BELOW WATERTABLE (z*J 6-10
6.7 AVERAGING PERIOD FOR Ground-water
CONCENTRATION AT RECEPTOR WELL (td) 6-11
7.0 REFERENCES 7-1
APPENDIX A: Determination of Infiltration and Recharge Rates
APPENDIX B: Nonlinear Sorption Isotherms Calculated Using the MINTEQA2
Model
APPENDIX C: Physical and Chemical Properties for Organic Constituents
APPENDIX D: WMU and Hydrogeologic Environment Databases
IV
-------
LIST OF FIGURES
Page
Figure 2.1 WMU Types Modeled in EPACMTP 2-3
Figure 2.2 Geographic Locations of Landfill WMUs 2-6
Figure 2.3 Geographic Locations of Surface Impoundment WMUs 2-7
Figure 2.4 Geographic Locations of Waste Pile WMUs 2-8
Figure 2.5 Geographic Locations of Land Application Unit WMUs 2-9
Figure 2.6 WMU with Base Elevation below Ground Surface 2-13
Figure 2.7 Schematic Cross-Section View of SI Unit 2-17
Figure 4.1 Locations of EPACMTP Climate Stations 4-5
Figure 5.1 Ground-water Temperature Distribution for Shallow Aquifers
in the United States (from Todd, 1980) 5-27
Figure 5.2 Geographical distribution of sites in the API-HGDB data base
(Reproduced from API, 1989) 5-37
Figure 5.3 Ground-water Temperature Distribution for Shallow Aquifers
in the United States (from Todd, 1980) 5-60
Figure 6.1 Schematic plan view showing procedure for determining the
downstream location of the receptor well: (a) well location
determined using radial distance, Rm, and angle off center 9m;
and (b) well location generated uniformly within plume limit 6-3
-------
This page intentionally left blank.
VI
-------
LIST OF TABLES
Page
Table 2.1 Waste Management Unit (Source) Parameters 2-4
Table 2.2 Cumulative Frequency Distribution of Landfill Area 2-11
Table 2.3 Cumulative Frequency Distribution of Landfill Depth 2-12
Table 2.4 Cumulative Frequency Distribution of Surface
Impoundment Area 2-18
Table 2.5 Cumulative Frequency Distribution of Surface Impoundment
Ponding Depth 2-19
Table 2.6 Cumulative Frequency Distribution of Surface Impoundment
Depth Below Grade 2-22
Table 2.7 Cumulative Frequency Distribution of Leak Density for
Composite-Lined Sis 2-23
Table 2.8 Cumulative Frequency Distribution of Distance to Nearest
Surface Water Body 2-24
Table 2.9 Cumulative Frequency Distribution of Surface Impoundment
Operating Life 2-26
Table 2.10 Cumulative Frequency Distribution of Waste Pile Area 2-27
Table 2.11 Cumulative Frequency Distribution of Land Application
Unit Area 2-30
Table 3.1 Waste and Constituent Parameters 3-2
Table 3.2 Default Cumulative probability distribution of waste density 3-4
Table 3.3 Empirical pH-dependent Adsorption Relations
(Loux et al., 1990) 3-25
Table 3.4 Metals that have MINTEQA2-derived Non-linear Isotherms .... 3-28
Table 3.5 Probability distribution of soil and aquifer pH 3-29
Table 3.6 Probability distribution of fraction iron hydroxide 3-31
Table 3.7 Probability distribution of leachate organic matter 3-32
Table 3.8 Probability distribution of percent organic matter in the
unsaturated zone 3-33
Table 3.9 Probability distribution of fraction organic carbon in the
saturated zone 3-35
Table 4.1 Climate Parameters 4-2
Table 4.2 Climate Centers Used in the HELP Modeling to Develop
Infiltration and Recharge Rates 4-3
Table 4.3 Cumulative Frequency Distribution of Landfill Infiltration 4-8
Table 4.4 Cumulative Frequency Distribution of Waste Pile Infiltration ... 4-10
Table 4.5 Cumulative Frequency Distribution of Land Application
Unit Infiltration 4-12
Table 4.6 Cumulative Frequency Distribution of Surface
Impoundment Infiltration 4-14
Table 4.7 Cumulative Frequency Distribution of Regional Recharge Rate . 4-16
Table 5.1 Hydrogeological Parameters 5-3
Table 5.2 Cumulative Frequency Distribution of Unsaturated
Zone Thickness 5-5
Table 5.3 Default EPACMTP Soil Types 5-6
VII
-------
LIST OF TABLES (continued)
Page
Table 5.4 Statistical parameters for soil properties for three soil types
used in the EPACMTP model (Carsel and Parrish, 1988 and
Carsel et al., 1988). All values are in arithmetic space 5-8
Table 5.5 Cumulative Frequency Distribution of Soil Hydraulic Conductivity 5-9
Table 5.6 Descriptive statistics for van Genuchten water retention
model parameters, a, p, and y (Carsel and Parrish, 1988) .... 5-10
Table 5.7 Cumulative Frequency Distribution of Alpha 5-11
Table 5.8 Cumulative Frequency Distribution of Beta 5-13
Table 5.9 Cumulative Frequency Distribution of Residual Water Content . 5-14
Table 5.10 Cumulative Frequency Distribution of Saturated Water Content 5-15
Table 5.11 Cumulative Frequency Distribution of Soil Bulk Density 5-17
Table 5.12 Cumulative Frequency Distribution of Percent Organic Matter . . 5-18
Table 5.13 Cumulative Frequency Distribution of Dispersivity 5-20
Table 5.14 Compilation of field dispersivity values (EPRI, 1985) 5-21
Table 5.15 Empirical distribution of mean particle diameter
(based on Shea, 1974) 5-30
Table 5.16 Cumulative Frequency Distribution of Particle Diameter 5-30
Table 5.17 Ratio between effective and total porosity as a function
of particle diameter (after McWorter and Sunada, 1977) 5-33
Table 5.18 Cumulative Frequency Distribution of Bulk Density 5-34
Table 5.19 HGDB Hydrogeologic Environments (from Newell et al., 1990) . 5-35
Table 5.20 Cumulative Frequency Distribution of Saturated Zone Thickness 5-44
Table 5.21 Cumulative Frequency Distribution of Hydraulic Conductivity . . . 5-45
Table 5.22 Cumulative Frequency Distribution of Regional
hydraulic gradient 5-48
Table 5.23 Cumulative Frequency Distribution of Ground-water
Seepage Velocity 5-50
Table 5.24 Probabilistic representation of longitudinal dispersivity 5-55
Table 5.25 Cumulative Frequency Distribution of Longitudinal Dispersivity . 5-55
Table 5.26 Cumulative Frequency Distribution of Horizontal
Transverse Dispersivity 5-57
Table 5.27 Cumulative Frequency Distribution of Vertical Dispersivity 5-59
Table 5.28 Probability distribution of aquifer pH 5-62
Table 5.29 Probability distribution of fraction organic carbon in the
saturated zone 5-64
Table 6.1 Receptor Well Parameters 6-1
Table 6.2 Cumulative Probability of Distance to Nearest Receptor Well for
Landfills (from EPA, 1993) 6-4
VIM
-------
ACKNOWLEDGMENTS
A large number of individuals have been involved with the development of
EPACMTP since its inception in the early 1990's. Dr. Zubair A. Saleem of the U.S.
EPA, Office of Solid Waste (EPA/OSW) has coordinated and guided the development
of EPACMTP throughout much of this period. Ms. Ann Johnson, Mr. David Cozzie, and
Mr. Timothy Taylor provided review for the development of this background document.
This report was prepared by the staffs of HydroGeoLogic, Inc. (HGL), and Resource
Management Concepts, Inc. (RMC), under EPA Contract Number 68-W-01-004.
IX
-------
This page intentionally left blank.
-------
LIST OF SYMBOLS AND ABBREVIATIONS
Symbol
Ar
Aw
B
cd
cs
CL
cv
cw
dBa
D,
DLF
Dm
Ds
Du
0s*
DWS
Ea
Fh
FeOx
foe
foe'
9
[HI
HP
1
ICLR
ID
IGWR
IGWT
ISTYPE
Definition
anisotropy ratio = K/KZ
area of aWMU (m2)
thickness of the saturated zone (m)
metal concentration in the dissolved phase at equilibrium
(mg/L)
metal concentration in the sorbed phase at equilibrium
(mg/L)
leachate concentration (mg/L)
coefficient of variation (%)
constituent concentration in the waste (mg/kg)
depth below grade of WMU (m)
molecular diffusion coefficient in free water for species /
(m2/yr)
landfill depth (m)
liner thickness (m)
total sediment thickness (m)
total depth of the unsaturated zone (m)
effective molecular diffusion coefficient for species of
interest (m2/y)
drinking water standard (mg/L)
Arrhenius activation energy (Kcal/mol)
volume fraction of the waste in the landfill at time of closure
(m3/m3)
iron hydroxide content (wt % Fe)
fractional organic carbon content (dimensionless)
fractional organic carbon content of the aquifer material
(dimensionless)
gravitational acceleration (m/s2)
hydrogen ion concentration (mol/L)
SI ponding depth (m)
annual infiltration rate through the source (m/y)
climate center index
metal identification number (unitless)
hydrogeologic environment index (unitless)
ground-water type - carbonate/non-carbonate (unitless)
soil type
Section
5.3.6
2.3.1,2.4.1,
2.5.1,2.6.1
5.3.4.3, 6.6
3.3.3.2
3.3.3.2
3.2.3
5.2.4
3.2.2
2.3.3, 2.4.6, 2.5.3
3.3.1.1
2.3.2
2.4.4
2.4.3
5.2.1
6.6
3.3.1.2
3.3.2.2.3
2.3.4
3.3.3.2.3
3.3.3.2.6
5.3.11
5.3.4.4
3.3.2.2.1
2.4.2
4.3.1,4.3.2,
4.3.3, 4.3.4
4.2
3.3.3.2.1
3.3.3.2.7,5.3.4.2
3.3.3.2.7
5.2.2
XI
-------
LIST OF SYMBOLS AND ABBREVIATIONS (continued)
Symbol
IWLOC
IP
J
K
ki
KJ
Kjr
KJ
KbTr
Kd
Kds
KJ
Kjr
^lin
KJ
KnTr
kd
koc
/c
Aow
K*
KX
Ky
6
LOM
LYCHK
LZCHK
Definition
Rra (Receptor well) origination method
effective recharge rate outside the strip source area (m/y)
or recharge rate outside the source area (m/y)
symbol used to denote a for the acid-catalyzed reaction, b
for the base-catalyzed reaction and n for the neutral
reaction
hydraulic conductivity (m/yr)
nonlinear Freundlich parameter for the unsaturated zone
(mg constituent/kg dry soil))
acid-catalyzed hydrolysis rate constant (1/(mol.yr))
acid-catalyzed hydrolysis rate constant at reference
temperature (1/(mol.yr))
base-catalyzed hydrolysis rate constant (1/(mol.yr))
base-catalyzed hydrolysis rate constant at reference
temperature (1/(mol.yr))
distribution (solid-aqueous phase) partition coefficient in the
unsaturated zone (cm3/g) (Freundlich Coefficient)
solid-liquid distribution coefficient of the aquifer (cm3/g)
hydrolysis rate constant for reaction process J, corrected
for the subsurface temperature T (1/(mol.yr) for the acid-
and base-catalyzed reactions; 1/yr for the neutral reaction)
hydrolysis rate constant for reaction process J, measured
at the reference temperature Tr (1/(mol.yr) for the acid- and
base-catalyzed reactions; 1/yr for the neutral reaction)
saturated hydraulic conductivity of liner (m/y)
neutral hydrolysis rate constant at (1/yr)
neutral hydrolysis rate constant at reference temperature
(1/yr)
soil-water partition coefficient (L/kg)
constituent-specific organic carbon partition coefficient
(cm3/g)
octanol-water partition coefficient (cm3/g)
saturated hydraulic conductivity (cm/hr)
hydraulic conductivity in the x direction (m/y)
hydraulic conductivity in the horizontal transverse (y)
direction (m/y)
daughter species number
leachate organic acid concentration (mol/L)
constraint on well distance from plume centerline
constraint on depth of intake point below water table
Section
6.5
4.4
3.3.2.2.3
5.3.4.4
5.2.9
3.3.2.2.1
3.3.2.2.3
3.3.2.2.2
3.3.2.2.5
3.3.3, 5.2.8
5.3.12
3.3.2.2.3
3.3.2.2.3
2.4.5
3.3.2.2.1
3.3.2.2.3
3.3.2.1
3.3.2.1
3.3.2.1
5.2.3
5.3.5
5.3.6
3.3.2.3.1
3.3.3.2.4
6.5
6.6
XII
-------
LIST OF SYMBOLS AND ABBREVIATIONS (continued)
Symbol
/
LN
M
m
MWt
N
NO
[OH']
%OM
PWS
PH
Qf
Qf
r
R9
R,
Rrw
R,,
R5
SB
SD
Tr
T
td
{P
v*
X
X
xrw
Definition
daughter species number
log normal distribution
number of immediate parent species
species number of immediate parent
molecular weight of species £ (g/mol.)
sample size
Normal distribution
hydroxyl ion concentration (mol/L)
percent organic matter (dimensionless)
waste volume (m3)
ground-water pH (standard units)
background ground-water flux (m2/y)
recharge flux downgradient of the source (m2/y)
regional hydraulic gradient (m/m)
Universal Gas Constant (1.987E-3 Kcal/deg-mol)
retardation factor for species i (dimensionless)
radial distance between waste management unit and well
(m)
distance between the center of the source and the nearest
downgradient boundary where the boundary location has
no perceptible effects on the heads near the source (m)
retardation coefficient (dimensionless)
log ratio distribution
standard deviation
hydrolysis reference temperature (°C)
ground-water/subsurface temperature (°C)
exposure time interval of interest (yr)
leaching duration (yr)
longitudinal ground-water (seepage) velocity (in the x-
direction) (m/y)
sample mean
principal Cartesian coordinate along the regional flow
direction (m)
distance from the downgradient boundary of the WMU to
the receptor well (m)
Section
3.3.2.3.1
5.2.2
3.3.2.3.2
3.3.2.3.3
3.3.1.3
5.2.4
5.2.2
3.3.2.2.2
33325 527
2.3.5
3.3.3.2.2,5.2.10,
5.2.13
6.6
6.6
5.3.4.5
3.3.2.2.3
3.3.2.1
6.2
2.4.8
5.3.7
5.2.2
5.2.4
3.3.2.2.6
3.3.2.2.3, 5.2.12,
5.3.9
6.8
2.3.6, 2.4.9,
2.5.2, 2.6.2
5.3.5
5.2.4
6.4
6.4
XIII
-------
LIST OF SYMBOLS AND ABBREVIATIONS (continued)
Symbol
xt
%w
y
YD
Yrw
Z
z*m
Definition
average travel distance in the x direction (m)
length of the WMU in the x-direction (parallel to ground-
water flow) (m)
principal Cartesian coordinate normal to the flow direction,
or distance from the plume centerline (m)
source width along the y-axis (m)
Cartesian coordinate of the receptor well in the y-direction
(m)
principal Cartesian coordinate in the vertical direction (m)
z-coordinate of the receptor well positive downward from
the water table(m)
Section
5.3.8.1
6.6
6.5
6.5
6.5
6.6
6.6
GREEK SYMBOLS
a
aL
VLU
OfRef
aT
av
P
Y
n
r?
0
er
9rw
es
A
4
4
4s
4s
Abu
van Genuchten soil-specific shape parameter (1/cm)
longitudinal dispersivity of the aquifer (m)
longitudinal dispersivity in the unsaturated zone (m)
reference longitudinal dispersivity, as determined from the
probabilistic distribution (m)
horizontal transverse dispersivity (m)
vertical transverse dispersivity (m)
van Genuchten soil-specific shape parameter
(dimensionless)
van Genuchten soil-specific shape parameter
(dimensionless) = 1 -1/(3
species-specific nonlinear Freundlich exponent for the
unsaturated zone
Freundlich exponent for the saturated zone
(dimensionless)
soil water content (dimensionless)
residual soil water content (dimensionless)
angle measured counter-clockwise from the plume
centerline (degrees)
saturated soil water content (dimensionless)
overall first-order hydrolysis transformation rate(1/y)
hydrolysis constant for dissolved phase (1/y)
hydrolysis constant for sorbed phase (1/y)
biodegradation rate in the saturated zone (1/yr)
chemical degradation rate in the saturated zone (1/yr)
transformation coefficient due to biological transformation
(1/y)
5.2.2, 5.2.4.1
5.3.8.1,6.6
5.2.6
5.3.8.1
5.3.8.2, 6.5
5.3.8.2, 6.6
5.2.2, 5.2.4.2
5.2.4
5.2.9
5.3.13
3.3.2.1
5.2.4.3
6.3
5.2.4.4
3.3.2.2
3.3.2.2.2
3.3.2.2.1
5.3.15
5.3.14
5.2.11
XIV
-------
LIST OF SYMBOLS AND ABBREVIATIONS (continued)
Symbol
ACU
fj
$/m
P
Ph
Pbu
-------
This page intentionally left blank.
XVI
-------
Section 1.0 Introduction
1.0 INTRODUCTION
This document provides background information on the parameters and data
sources used in EPA's Composite Model for Leachate Migration with Transformation
Products (EPACMTP). EPACMTP is a subsurface fate and transport model used by
EPA's Office of Solid Waste in the RCRA program to establish regulatory levels for
concentrations of constituents in wastes managed in land-based units. This
document describes the EPACMTP input parameters, data sources and default
parameter values and distributions that EPA has assembled for its use of EPACMTP
as a ground-water assessment tool. EPA has also developed a complementary
document, the EPACMTP Technical Background Document (U.S. EPA, 2003a),
which presents the mathematical formulation, assumptions and solution methods
underlying the EPACMTP. These two documents together are the primary reference
documents for EPACMTP, and are intended to be used together.
The remainder of this section describes how this background document is
organized. The parameters and data are documented in six main categories, as
follows:
• Section 2 describes the Waste Management Unit (Source)
Parameters;
Section 3 describes the Waste and Constituent Parameters;
Section 4 describes the Infiltration and Recharge Parameters;
Section 5 describes the Subsurface Parameters;
Section 6 describes the Ground-water Well Location Parameters; and
Section 7 provides a list of References
Several appendices provide complete listings of data distributions for a
number of the EPACMTP input parameters.
To facilitate the cross-referencing of information between this document and
the EPACMTP Technical Background Document (U.S. EPA, 2003a), each section
begins with a table that lists the parameters described in that section, and provides,
for each parameter, a reference to the equation(s) and/or section number in the
EPACMTP Technical Background Document (U.S. EPA, 2003a) that describes how
each parameter is used in the EPACMTP computer code.
1-1
-------
This page intentionally left blank.
-------
Section 2.0 Waste Management Unit (Source) Parameters
2.0 WASTE MANAGEMENT UNIT (SOURCE) PARAMETERS
EPACMTP can simulate the subsurface migration of leachate from four
different types of waste management units (WMUs). Each of the four unit types
reflects waste management practices that are likely to occur at industrial Subtitle D
facilities. The WMU can be a landfill, a waste pile, a surface impoundment, or a land
application unit. The latter is also sometimes called a land treatment unit. Figure
2.1 presents schematic diagrams of the different types of WMUs modeled in
EPACMTP.
Landfill. Landfills (LFs) are facilities for the final disposal of solid waste on
land. EPACMTP is typically used to model closed LFs with an earthen cover. LFs
may be unlined, or they may have some type of engineered liner, but the model
assumes no leachate collection system exists underneath the liner. The LF is filled
with waste during the unit's operational life. Upon closure of the LF, the waste is left
in place, and a final soil cover is installed. The starting point for the EPACMTP
simulation is the time at which the LF is closed, i.e., the unit is at maximum capacity.
The release of waste constituents into the soil and ground water underneath the LF
is caused by dissolution and leaching of the constituents due to precipitation which
percolates through the LF. The type of liner that is present (if any) controls, to a
large extent, the amount of leachate that is released over time from the unit. LFs
are modeled in EPACMTP as WMUs with a rectangular footprint and a uniform
depth. The EPACMTP model does not explicitly account for any loss processes
occurring during the unit's active life (for example, due to leaching, volatilization,
runoff or erosion, or biochemical degradation), however these processes will be
taken into account if the input value for leachate concentration is based on a site-
specific chemical analysis of the waste (such as results from a Toxicity
Characteristic Leaching Procedure (TCLP) or Synthetic Precipitation Leaching
Procedure (SPLP) analysis). The leachate concentration used as a model input is
the expected initial leachate concentration when the waste is 'fresh'. Because the
LF is closed, the concentration of the waste constituents will diminish with time due
to depletion of the landfilled wastes; the model is equipped to simulate this
"depleting source" scenario for LFs, but other source options are available, and are
explained in Section 2.3.
Surface Impoundment. A surface impoundment (SI) is a WMU which is
designed to hold liquid waste or wastes containing free liquid. Sis may be either
ground level or below ground level flow-through units. They may be unlined, or they
may have some type of engineered liner. Release of leachate is driven by the
ponding of water in the impoundment, which creates a hydraulic head gradient
across the barrier underneath the unit. The EPACMTP model considers a SI to be a
temporary WMU with a finite operational life. At the end of the unit's operational life,
we assume there is no further release of waste constituents to the ground water
(that is, there is a clean closure of the SI). Sis are modeled as pulse-type sources;
leaching occurs at a constant leachate concentration over a fixed period of time
equal to the unit's operating life. The EPACMTP model assumes a constant
2-1
-------
Section 2.0 Waste Management Unit (Source) Parameters
ponding depth (depth of waste water in SI) during the operational life (see Section
2.2.4).
Waste Pile. Waste piles (WPs) are typically used as temporary storage or
treatment units for solid wastes. Due to their temporary nature, they are typically not
covered. Similar to LFs, WPs may be unlined, or they may have some type of
engineered liner. EPACMTP assumes that WPs have a fixed operational life, after
which the WP is removed. Thus, WPs are modeled as pulse-type sources; leaching
occurs at a constant leachate concentration over a fixed period of time which is
equal to the unit's operating life (see Section 2.5.2).
Land Application Unit. Land application units (LAUs) (or land treatment units)
are areas of land receiving regular applications of waste that is either tilled directly
into the soil or sprayed onto the soil and then tilled. EPACMTP models the leaching
of wastes after they have been tilled with soil. EPACMTP does not account for the
losses due to volatilization during or after waste application. LAUs are only
evaluated for the no-liner scenario because liners are not typically used at this type
of facility. EPACMTP assumes that an LAU is a temporary WMU with a fixed
operational life, after which the waste is no longer land-applied. Thus, LAUs are
modeled in EPACMTP as a constant pulse-type leachate source, with a leaching
duration equal to the unit's operational life (see Section 2.6.2).
2-2
-------
Section 2.0
Waste Management Unit (Source) Parameters
Cover
unsaturated zone
saturated zone
(A) LANDFILL
unsaturated zone
saturated zone
(C) WASTE PILE
unsaturated zone
saturated zone
(B) SURFACE IMPOUNDMENT
unsaturated zone
V
saturated zone
(D) LAND APPLICATION UNIT
Figure 2.1 WMU Types Modeled in EPACMTP.
2-3
-------
Section 2.0
Waste Management Unit (Source) Parameters
2.1 SOURCE PARAMETERS
The input parameters used in EPACMTP to describe the waste management
unit are listed below in Table 2.1
Table 2.1 Waste Management Unit (Source) Parameters
WMU
Type
LF
SI
WP
LAU
Parameter
Area
Depth
Depth Below Grade
Landfill Waste
Fraction (Volume
Fraction)
Waste Volume
Leaching Duration
Area
Ponding Depth
Total Sediment
Thickness
Liner Thickness
Liner Conductivity
Depth Below Grade
Leak Density
Distance to Nearest
Surface Water Body
Operating
Life/Leaching Duration
Area
Operating
Life/Leaching Duration
Depth Below Grade
Area
Operating Life/
Leaching Duration
Symbol
Aw
DLF
dBG
Fh
PWS
tp
Aw
HP
Ds
D,in
Klin
dBG
Pleak
FL
V
"w
tp
dBG
Aw
tp
Units
m2
m
m
m3/m3
m3
yr
m2
m
m
m
m/yr
m
holes/m2
m
yr
m2
yr
m
m2
yr
Section
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.4.1
2.4.2
2.4.3
2.4.4
2.4.5
2.4.6
2.4.7
2.4.8
2.4.9
2.5.1
2.5.2
2.5.3
2.6.1
2.6.2
Equation in
EPACMTP TBD
2.3
2.3
2.2.2.2
2.5
2.7
2.2.2.2
2.17
2.2.2.2
2.24b
2.24b
2.24b
2.24C
2.31
2.2.2.2
2.27
2.27
2.2.2.2
2.30
2.30
2.2 DATA SOURCES FOR WMU PARAMETERS
Data from two nationwide EPA surveys of non-hazardous (RCRA Subtitle D)
industrial facilities were used to develop databases of EPACMTP input values for
WMU parameters. Data for LFs, WPs, and LAUs were obtained from an EPA
survey of industrial Subtitle D facilities conducted in 1985 (U.S. EPA, 1986, referred
2-4
-------
Section 2.0 Waste Management Unit (Source) Parameters
to as "The 1986 Subtitle D Survey"). The survey provides a statistically
representative subset of observations of site specific areas, volumes and locations
for industrial Subtitle D facilities in the United States. Data for Sis were obtained
from a recent U.S. EPA survey of industrial Sis (U.S. EPA, 2001 a, "Surface
Impoundment Study'}. What follows is a general description of the data used from
these two studies to compile the databases of WMU input parameters for the
EPACMTP model; the actual distributions of values of these WMU input parameters
are then summarized in Sections 2.3 - 2.6, and are listed in their entirety in Appendix
D.
The WMU locations are shown in Figures 2.2 - 2.5. Information on WMU
locations was used to coordinate other WMU-specific data with climate and
hydrogeological parameter values. Specifically, we first used the HELP (Schroeder,
et. al., 1994) water balance model and climate data from 102 climate stations and
three common soil types to develop infiltration and recharge rates for unlined and
single-lined WMUs (see Section 4.2 and Appendix A). Then, for each WMU site, we
assigned: 1) a climate index corresponding to the nearest, representative climate
station (used to select infiltration and recharge rates) (see Section 4.2); 2) a
hydrogeologic index according to the regional aquifer type used to generate depth
to water and aquifer characteristics (see Sections 5.2 and 5.3); and 3) a soil and
aquifer temperature used to calculate hydrolysis transformation rates for organic
constituents (see Sections 3.6.2 and 4.3). This allows appropriate site-based climate
and hydrogeological parameter values to be generated for each site in the WMU
database "on the fly" while the EPACMTP model is running a Monte Carlo analysis.
Landfills
The 1986 Subtitle D Survey provided LF data consisting of 824 observations
of facility locations, area, number of units in the facility, facility design capacity, total
remaining facility capacity, and the relative weight of each facility. The relative
weight was assigned based on the total number of employees working at the facility
and reflects the quantity of the waste managed in that facility. The values of
physical characteristics for each WMU were obtained by dividing the facility values
by the number of units in the facility.
LF data were screened to eliminate unrealistic observations by placing
constraints on the WMU depth and volume . The WMU depth, calculated by dividing
the unit capacity by its area, was constrained to be greater than or equal to 2 feet
(0.67m), and less than or equal to 33 feet (10m); these limits on unit depth were
adopted from a previous analysis used to support the Toxicity Characteristic (TC)
Rule (U.S. EPA, 1990). In addition, the LF volume was constrained to be greater
than the remaining capacity.
A joint distribution was derived from available unit areas correlated with unit
volumes that met the unit depth and remaining capacity constraints. The distribution
was assumed to be lognormal. Random samples of this distribution were used in
cased where the unit area, the unit volume, or both were missing.
2-5
-------
Section 2.0
Waste Management Unit (Source) Parameters
If the WMU depth or remaining capacity constrains were violated, the reported unit
volume was replaced with a sample from the joint distribution, based on the reported
unit area, based on the assumption that the reported unit area was more likely to be
correct.
Figure 2.2 shows the geographic locations of LF WMUs used in developing
the EPACMTP database of LF sites. A compete listing of the site-based LF input
parameter values is provided in Appendix D.
Figure 2.2 Geographic Locations of Landfill WMUs.
Surface Impoundments
The original EPACMTP database of SI input parameter values (based on the
1986 Subtitle D survey) was updated with more complete data derived from the
results of EPA's recent 5-year study of nonhazardous (Subtitle D) industrial Sis in
the United States (U.S. EPA, 2001 a). The Surface Impoundment Study is the
product of a national survey of facilities that operate non-hazardous industrial waste
Sis. The updated database is comprised of SI characteristics from 503 SI units
located at 143 facilities throughout the United States.
The Surface Impoundment Study provided data on impoundment locations,
area, operating depths (depth of ponding in the impoundment), depth of the SI base
2-6
-------
Section 2.0
Waste Management Unit (Source) Parameters
below the ground surface, sludge volume, operational life of the impoundment,
closure plans, and proximity of the impoundment to a surface water body.
The current version of the EPACMTP database of SI sites was compiled for
analyses included in the U.S. EPA Industrial Waste Management Evaluation Model
(U.S. EPA, 2003b). As a result, the database includes assumptions specific to that
effort. Specifically, the thickness of sludge at the bottom of SI units was assumed to
be 0.2 m for all sites; sites with unknown operating lines and no closure plans were
assumed to operate for 50 years; all units were assumed to be built on top of the
ground surface; and unknown distances to the nearest surface water body or
distances given as >2,000 m were set to 5,000 m.
Figure 2.3 shows the geographic locations of SI WMUs (from the Surface
Impoundment Study) used in developing the EPACMTP database of SI sites. Due
to the scale of this map, the individual units at each facility are not shown. A
compete listing of the site-based SI input parameter values is provided in Appendix
D.
Figure 2.3 Geographic Locations of Surface Impoundment WMUs.
2-7
-------
Section 2.0
Waste Management Unit (Source) Parameters
Waste Piles
The 1986 Subtitle D survey included 847 WP facilities with data on facility
area, number of units, and the total amount of waste placed in the facility (waste
volume) in 1985. Unit values were derived by dividing the facility values by the
number of units in the facility. No screening constraints were placed on the WP
data. The 114 facility areas and the 30 facility waste volumes reporting zero values
were set to 0.005 acres (20 m2) and 0.005 mega-tons (Mton), respectively. These
default values were adopted from a previous analysis used to support the Toxicity
Characteristic (TC) Rule (U.S. EPA, 1990).
Thirty facilities did not report waste volume. All facilities reported facility
area. Missing volume values were replaced by random realizations from the
probability distribution of volume conditioned on area. The conditional distribution
was assumed to be lognormal and was derived from the non-missing unit
area/volume pairs.
Figure 2.4 shows the geographic locations of WP WMUs used in developing
the EPACMTP database of WP sites. A compete listing of the site-based WP input
parameter values is provided in Appendix D.
Figure 2.4 Geographic Locations of Waste Pile WMUs.
2-8
-------
Section 2.0
Waste Management Unit (Source) Parameters
Land Application Units
The 1986 Subtitle D survey included 352 LAU facilities, with data on location,
area, number of units in each facility, and the total amount of waste managed (waste
volume) in 1985. Individual unit values were derived by dividing the facility values by
the number of units in the facility. Application rates were derived by dividing the
waste managed in 1985 by the site acreage. Unrealistic values were screened from
these data by constraining the waste application rates to be less than 10,000
tons/acre/year. This assumes a maximum application rate of 200 dry tons/acre/year
with a 2% solids content.
Eight did not report waste volume, and twelve were screened out due to the
application rate constraint. Of the 352 facilities, all reported a facility and none were
screened. Three reported zero areas and nine reported zero waste volumes were
set to 0.005 acres (20 m2) and 0.005 Mton, respectively.
Missing and screened values were replaced by random realizations from the
joint area/volume probability distribution or the corresponding marginal distributions
depending on whether both or only one of either the waste volume or area values
were missing or screened. The joint distribution was assumed to be lognormal and
was derived from the non-missing unit area/volume pairs that met the unit depth
constraint.
Figure 2.5 shows the geographic locations of LAU WMUs used in developing
the EPACMTP database of LAU sites. A compete listing of the site-based database
of LAU input parameter values is provided in Appendix D.
Figure 2.5 Geographic Locations of Land Application Unit WMUs.
2-9
-------
Section 2.0 Waste Management Unit (Source) Parameters
2.3 LANDFILLS (LF)
This section discusses the individual WMU-related parameters required to
perform a LF analysis using EPACMTP. Most applications of EPACMTP are for
national or regional regulatory development purposes, in which case, each of the
following LF input parameters is described using a probability distribution. The
default distributions are described in the following sections. However, EPACMTP
can also be used in a location-waste-specific mode; in this case, each of the
following LF input parameters could be assigned a site-specific constant value or a
site-specific distribution of values. These site-specific data need to be gathered by
the user prior to performing the EPACMTP modeling analysis. However, site-
specific implementation of EPACMTP will yield results which may not reflect the site-
specific heterogeneities and anisotropic conditions.
The source-specific input parameters for the LF scenario include parameters
to determine the amount of waste disposed in the LF and the source leaching
duration. Together with the infiltration and recharge rates and the initial waste and
leachate concentrations, these parameters are used to determine how much
contaminant mass enters the subsurface and over what time period. The source-
specific parameters for the LF scenario are individually described in the following
sections.
2.3.1 Landfill Area (A...)
Definition
The LF area is defined as the footprint of the LF. EPACMTP assumes the
LF to be rectangular. By default, the length and width of the LF are each calculated
as the square root of the area.
Parameter Value or Distribution of Values
The entire distribution is presented in Appendix D. The cumulative frequency
distribution of LF area is listed in Table 2.2. For a given percentile (%) frequency
and area value pair in this table, the percentile denotes the relative frequency or
likelihood of parameter values in the entire distribution being less than or equal to
the corresponding parameter value in the right-hand column.
2-10
-------
Section 2.0
Waste Management Unit (Source) Parameters
Table 2.2 Cumulative Frequency Distribution of Landfill Area.
%
0
10
25
50
75
80
85
90
95
100
Area (m2)
4.05E+01
4.86E+02
2.43E+03
1.21E+04
5.26E+04
6.56E+04
9.11E+04
1.42E+05
2.23E+05
3.12E+06
Data Sources
The data for LF area listed in Table 2.2 were obtained from EPA's 1986
Subtitle D Survey (U.S. EPA, 1985).
Use In EPACMTP
The LF area is used to determine the area over which leachate enters the
subsurface. It is also one of several parameters used to calculate the total
contaminant mass present in the LF at closure. The total contaminant mass is a
necessary input when using the LF depleting source option, since the contaminant is
leached to the subsurface until the waste in the LF is depleted (see Section 2.2.1.3.3
of the EPACMTP Technical Background Document, U.S. EPA, 2003a).
2.3.2 Landfill Depth (DIC)
Definition
The LF depth is defined as the average depth of the LF, from top to bottom;
the thickness of the cover soil is assumed to be small compared to the depth. Note
that the LF depth is measured from the top to the base of the unit, irrespective of
where the ground surface is.
Parameter Value or Distribution of Values
The entire distribution is presented in Appendix D. The cumulative frequency
distribution of LF depth is listed in Table 2.3. For a given percentile (%) frequency
and value pair in this table, the percentile denotes the relative frequency or likelihood
of parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right-hand column.
2-11
-------
Section 2.0
Waste Management Unit (Source) Parameters
Table 2.3 Cumulative Frequency Distribution of Landfill Depth.
%
0
10
25
50
75
80
85
90
95
100
Depth (m)
5.10E-01
8.80E-01
1.32E+00
2.57E+00
4.09E+00
4.53E+00
5.20E+00
6.13E+00
7.12E+00
1.01E+01
Data Sources
Data for the nationwide distribution of LF depths was obtained from the 1986
Subtitle D survey (EPA, 1986).
Use In EPACMTP
The LF depth is one of several parameters used to calculate the contaminant
mass within the LF; the contaminant mass is an important input for the LF depleting
source option (see Section 2.2.1.3.3 of the EPACMTP Technical Background
Document; U.S. EPA, 2003a).
2.3.3 Landfill Base Depth below Grade (dDf.)
Definition
The depth below grade is defined as the depth of the bottom of the LF below
the surrounding ground surface, as schematically depicted in Figure 2.6.
2-12
-------
Section 2.0
Waste Management Unit (Source) Parameters
, WASTE MANAGEMENT UNIT
1 GROUND SURFACE
DEPTH OF THE WMU BASE ' ' 1 1
VLINER DEPTHTO
WATER TABLE ^7
SATURAT
THICK
'
WATER TABLE
ED ZONE
NESS
///^//^//^///^//^//^^^
Figure 2.6 WMU with Base Elevation below Ground Surface.
Parameter Value or Distribution of Values
Data for this parameter were not included in the EPA's 1986 Industrial
Subtitle D Survey. Unless site-specific data are available, users should set this
parameter to zero, which is equivalent to assuming the base of the unit lies on the
ground surface.
Data Sources
No nationwide distribution of values is currently available. For LF modeling
analyses, this parameter value is typically set to zero, unless site-specific data are
available.
Use In EPACMTP
If a non-zero value is entered for this input, then the thickness of the vadose
zone beneath the LF is adjusted accordingly. In this case, EPACMTP will also verify
that the entered value, in combination with the depth to the water table, and
magnitude of the unit's infiltration rate, does not lead to a physically infeasible
condition (e.g.,the LF base is not in contact with a static water table or an infiltration-
induced water table mound) in accordance with the infiltration screening
methodology presented in Section 2.2.5 of the EPACMTP Technical Background
Document (EPA, 2003a).
2-13
-------
Section 2.0 Waste Management Unit (Source) Parameters
2.3.4 Waste Fraction (Fh)
Definition
The waste fraction is defined as the fraction of the LF volume occupied by
the modeled waste at LF closure.
Parameter Value or Distribution of Values
By default, this parameter is defined as a uniform distribution with lower and
upper bounds of 0.036 to 1.0, respectively. However, if warranted by site-specific
conditions or other assumptions, this parameter can also be set to 1.0 (the most
protective case - equivalent to a monofill scenario), another constant value, or
another distribution of values.
Data Sources
The default lower bound of 0.036 (which ensures that the modeled waste unit
will always contain a minimum amount of the waste of concern), was obtained from
an analysis of waste composition in municipal LFs (Schanz and Salhotra, 1992).
The upper bound is the maximum value that is physically possible (the waste in the
LF is composed completely of the waste of concern).
Note that an input value for this parameter is required for the LF scenario
only.
Use In EPACMTP
EPACMTP uses the waste fraction to calculate the contaminant mass within
the LF; the contaminant mass is an important input for the LF depleting source
option (see Section 2.2.1.3.3 of the EPACMTP Technical Background Document,
U.S. EPA, 2003a).
2.3.5 Waste Volume (PWS)
Definition
The waste volume is defined as the volume of the waste of interest (at LF
closure) contributed to the Subtitle D LF.
2-14
-------
Section 2.0 Waste Management Unit (Source) Parameters
Parameter Value or Distribution of Values
The waste volume is an input parameter that depends on the EPACMTP
application. For nationwide risk assessments, EPA has typically assumed a default
uniform distribution, where the waste volume is entered as a fraction of the entire
landfill volume (see Waste Fraction in Section 2.3.4). If the landfill volume and the
waste volume are treated as random parameters, specifying the waste volume in
terms of a waste fraction ensures that the modeled waste volume can never exceed
the modeled landfill volume.
For site-specific applications of EPACMTP, the waste volume that is entered
as an EPACMTP input parameter can be calculated by multiplying the annual waste
volume by the number of years of landfill operation. If the annual waste amount is
given as a mass value (e.g., tons/year), it should be divided by the waste density in
order to yield the value as a volume. The user should ensure that the modeled
waste volume does not exceed the landfill volume.
Data Sources
Data sources depend on the EPACMTP application and are typically
provided by waste generation data. For nationwide LF modeling analyses, this
parameter is typically specified in terms of a waste fraction.
Use In EPACMTP
EPACMTP uses the waste volume to calculate the contaminant mass within
the LF; the contaminant mass is an important parameter for the LF depleting source
option (see Section 2.2.1.3.3 of the EPACMTP Technical Background Document,
U.S. EPA, 2003a).
2.3.6 Leaching Duration (tr)
Definition
The leaching duration is defined as the period of time that leachate is
released from the WMU.
Parameter Value or Distribution of Values
By default, this parameter is set as a "derived" parameter to be calculated
internally by EPACMTP as a function of the total amount of contaminant that is
initially present in the landfill, and the rate of removal through the leaching process.
Alternatively, the user may set this parameter to a specific constant value or a
distribution of values.
2-15
-------
Section 2.0 Waste Management Unit (Source) Parameters
Data Sources
No nationwide distribution of values is currently available. For LF modeling
analyses, this parameter is typically set to be internally derived by EPACMTP.
Use In EPACMTP
If the leaching duration is set to a user-provided value or distribution,
EPACMTP will model the LF using a pulse source (leaching at a constant
concentration over a finite, pre-defined time period).
More commonly, the LF is modeled as a permanent waste management unit;
in this case, the EPACMTP model assumes that leaching continues until the waste is
depleted. To model this depleting source scenario, this input parameter should be
specified as internally derived by EPACMTP. For a detailed discussion of how the
LF source depletion rate is calculated, see Section 2.2.1.3.3 of the EPACMTP
Technical Background Document (U.S. EPA, 2003a).
2.4 SURFACE IMPOUNDMENT (SI)
This section discusses the individual WMU-related parameters required to
perform a SI analysis using EPACMTP. Most applications of EPACMTP are
conducted on a national or regional basis for regulatory development purposes, in
which case, most of the following SI input parameters would be described using the
default probability. Distributions are discussed in the following sections. However,
EPACMTP can also be used in a location- or waste-specific mode; in this case, each
of the following SI input parameters could be assigned a site-specific constant value
or a site-specific distribution of values. These site-specific data need to be gathered
by the user prior to performing the EPACMTP modeling analysis.
The source-specific inputs for the SI scenario include parameters to
determine the unit dimensions, ponding depth, and leaching duration. Together with
the infiltration and recharge rates and the leachate concentration, these parameters
are used to determine how much contaminant mass enters the subsurface and over
what time period.
The source-specific parameters for the SI scenario are individually described
in the following sections, and Figure 2.7 illustrates a compartmentalized SI as
implemented in the EPACMTP model. Shown in the figure are, in descending order:
the liquid compartment, the sediment compartment (with loose and consolidated
sediments), and the vadose zone (with clogged and unaffected native materials).
2-16
-------
Section 2.0
Waste Management Unit (Source) Parameters
Top of Liquid Compartment
Ground
Surface
Elevation
Liquid Compartment
Clogged Native Soil or Clay Liner
Ground ^^
Surface
Elevation
Unaffected Native Material
,, Infiltration
Water
= Table
Figure 2.7 Schematic Cross-Section View of SI Unit.
2.4.1 Surface Impoundment Area (A,.,)
Definition
The SI area is defined as the footprint of the impoundment. In EPACMTP,
the impoundment is assumed to be rectangular. By default the unit is assumed to
be square, i.e., to have equal length and width which are each calculated as the
square root of the area.
Parameter Value or Distribution of Values
The entire distribution is presented in Appendix D. The cumulative frequency
distribution of SI area is listed in Table 2.4. For a given percentile (%) frequency
and value pair in this table, the percentile denotes the relative frequency or likelihood
of parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right-hand column.
2-17
-------
Section 2.0
Waste Management Unit (Source) Parameters
Table 2.4 Cumulative Frequency Distribution of Surface Impoundment Area.
%
0
10
25
50
75
80
85
90
95
100
Area (m2)
9.30E+00
1.74E+02
4.01 E+02
1.77E+03
6.97E+03
8.90E+03
1.67E+04
2.83E+04
5.16E+04
4.86E+06
Data Sources
The data for SI area listed in Table 2.2 were obtained from EPA's Surface
Impoundment Study (U.S. EPA, 2001 a).
Use In EPACMTP
The SI area represents the total surface area over which infiltration and
leachate enter the subsurface.
2.4.2 Surface Impoundment Ponding Depth (Hr)
Definition
The ponding depth is the average depth of the wastewater in the liquid
compartment as shown in Figure 2.7; that is, this value does not include any
sediment accumulated at the base of the unit.
Parameter Value or Distribution of Values
The entire distribution is presented in Appendix D. The cumulative frequency
distribution of SI ponding depth is listed in Table 2.5. For a given percentile (%)
frequency and value pair in this table, the percentile denotes the relative frequency
or likelihood of parameter values in the entire distribution being less than or equal to
the corresponding parameter value in the right-hand column.
2-18
-------
Section 2.0
Waste Management Unit (Source) Parameters
Table 2.5 Cumulative Frequency Distribution of Surface Impoundment
Ponding Depth.
%
0
10
25
50
75
80
85
90
95
100
SI Ponding Depth (m)
1.00E-02
4.60E-01
9.93E-01
1.81E+00
2.95E+00
3.44E+00
3.66E+00
4.24E+00
5.32E+00
1.82E+01
Data Sources
Data for the nationwide distribution of SI ponding depths was obtained from
the 2001 Surface Impoundment Study (EPA, 2001 a).
Use In EPACMTP
The SI ponding depth is added to the unconsolidated sediment thickness
(one-half of the total sediment thickness; see Section 2.4.4); this sum represents the
hydraulic head that drives leakage of water from the SI. EPACMTP uses this
parameter in order to calculate SI infiltration rates (see Section 4.3.4).
2.4.3 Surface Impoundment Total Thickness of Sediment (DJ
Definition
The SI total thickness of sediment is the average thickness of accumulated
sediment (sludge) deposits on the bottom of the impoundment. This layer of
accumulated sediment is different from an engineered liner underneath the
impoundment, but its presence will serve to restrict the leakage of water from an
impoundment, especially in unlined units. The EPACMTP model assumes that the
accumulated sediment consists of two equally thick layers, an upper unconsolidated
layer and a lower consolidated layer ('filter cake') that has been compacted due to
the weight of the sediment and wastewater above it, and, therefore, has a reduced
porosity and permeability.
2-19
-------
Section 2.0 Waste Management Unit (Source) Parameters
Parameter Value or Distribution of Values
A default value of 0.2m was adopted for the development of EPA's Industrial
Waste Management Evaluation Model (U.S. EPA, 2003b). This agrees with the
determination EPA made for values in the SI module of EPACMTP. Alternative data
on this parameter are available, and can be extracted from EPA's Surface
Impoundment Survey. However, these data have not currently been included in
EPACMTP database of SI sites. See Section 2.2 for more information on the SI site
database.
Data Sources
Data on SI sediment thicknesses were acquired from the nationwide 2001
Surface Impoundment Study (EPA, 2001 a).
Use In EPACMTP
The EPACMTP model uses the SI sediment thickness to calculate the rate of
infiltration from unlined and single-lined Sis (see Section 4.2). The calculated
infiltration rate is inversely related to the thickness of the sediment layer assuming
constant ponding depth. A lower value for sediment thickness will result in a higher
infiltration rate, and a greater rate of constituent loss from the impoundment. A
detailed description of the EPACMTP SI infiltration module is provided in Section
2.2.2.3 of the EPACMTP Technical Background Document (U.S. EPA, 2003a).
2.4.4 Surface Impoundment Liner Thickness (DMn)
Definition
EPACMTP is able to account for infiltration through a single compacted clay
liner beneath the SI. In the event that the SI is single-lined, the thickness of the liner
must be provided. The liner thickness is defined as the average thickness of the
single completed clay liner by which the SI is underlain. Additionally, the base of a
lined SI is defined to be the interface between the liner and the native soils below.
This definition permits EPACMTP to establish the elevation of the top of the liquid
compartment relative to the unit base.
Parameter Value or Distribution of Values
As a default, EPA has assumed the SI clay liner thickness to be a constant
3 ft. or 0.916 m for nationwide or regional analyses. However, liner thickness can be
represented by a distribution with the limitation that the minimum value be greater
than zero. The clay liner is not allowed to be less than 0.1m to ensure numeric
stability of the unsaturated zone flow simulation module.
2-20
-------
Section 2.0 Waste Management Unit (Source) Parameters
Data Sources
The default liner thickness of 3 feet is based on typical design criteria for
compacted clay liners underneath land disposal units (U.S. EPA, 2003b).
Use In EPACMTP
The EPACMTP model uses the SI liner thickness to calculate the rate of
infiltration from the unit (see Section 4.2). The calculated infiltration rate is inversely
related to the thickness of the liner assuming constant ponding depth. A detailed
description of the EPACMTP SI infiltration module is provided in Section 2.2.2.3 of
the EPACMTP Technical Background Document (U.S. EPA, 2003a).
2.4.5 Surface Impoundment Liner Conductivity (KMn)
Definition
The liner hydraulic conductivity is defined as the average saturated hydraulic
conductivity of the clay liner mentioned in Section 2.4.4.
Parameter Value or Distribution of Values
By default, EPA has assumed the SI liner conductivity for compacted clay
liners to be a constant 1.0 x 10"7cm/s or 3.15 x 10~2 m/yr for nationwide and regional
analyses. However, liner conductivity can be represented by any value or
distribution of values with the limitation that the minimum liner conductivity must be
greater than zero.
Data Sources
The default value of 1 x 10~7 cm/sec is based on typical design criteria for
compacted clay liners beneath land disposal units and is the maximum
recommended hydraulic conductivity for a compacted clay liner given in the EPA's
Guide for Industrial Waste Management (U.S. EPA, 2003; EPA530-R-03-001).
Use In EPACMTP
The EPACMTP model uses the SI liner conductivity to calculate the rate of
infiltration from the WMU (see Section 4.2). The calculated infiltration rate is directly
related to the conductivity of the liner, assuming constant ponding depth. A detailed
description of the EPACMTP SI infiltration module is provided in Section 2.2.2.3 of
the EPACMTP Technical Background Document (U.S. EPA, 2003a).
2-21
-------
Section 2.0
Waste Management Unit (Source) Parameters
2.4.6 Surface Impoundment Base Depth Below Grade (dp^)
Definition
This parameter represents the depth of the base of the unit below the
surrounding ground surface, as schematically depicted in Figure 2.6.
Parameter Value or Distribution of Values
The default distribution is presented in Appendix D. The cumulative
frequency distribution of SI depth below grade is summarized in Table 2.6. For a
given percentile (%) frequency and value pair in this table, the percentile denotes the
relative frequency or likelihood of parameter values in the entire distribution being
less than or equal to the corresponding parameter value in the right-hand column.
Table 2.6 Cumulative Frequency Distribution of Surface Impoundment Depth
Below Grade.
%
0
10
25
50
75
80
85
90
95
100
SI Deoth Below Grade (m)
O.OOE+OO
O.OOE+00
O.OOE+OO
1.22E+00
3.05E+00
3.58E+00
3.90E+00
4.57E+00
5.18E+00
3.35E+01
Data Sources
Data for this nationwide distribution for SI base depth below grade from the
2001 Surface Impoundment Study (EPA, 2001 a).
Use In EPACMTP
The depth of the base of the unit below the ground surface reduces the travel
distance through the unsaturated zone before leachate constituents reach the water
table. If a non-zero value is entered, EPACMTP will verify that the entered value, in
combination with the depth to the water table, and magnitude of the unit's infiltration
rate, does not lead to a physically infeasible condition (e.g., water table mound
height above the ground surface or above the level of the waste liquid in an
impoundment) in accordance with the infiltration screening methodology presented
in Section 2.2.5 of the EPACMTP Technical Background Document (EPA, 2003a).
2-22
-------
Section 2.0
Waste Management Unit (Source) Parameters
2.4.7 Surface Impoundment Leak Density (p|a,k)
Definition
EPACMTP can also account for infiltration through composite liners. The
infiltration is assumed to result from defects (pinholes) in the geomembrane. The
pinholes are assumed to have a circular shape and be uniform in size. The leak
density is defined as the average number of circular pinholes per hectare.
Parameter Value or Distribution of Values
The cumulative frequency distribution of SI composite liner leak density is
listed in Table 2.7.
Table 2.7 Cumulative Frequency Distribution of Leak Density for Composite-
Lined Sis.
%
0
10
20
30
40
50
60
70
80
90
100
Leak density (No. Leaks/ha)
0
0
0
0
0.7
0.915
1.36
2.65
4.02
4.77
12.5
Data Sources
A nationwide, default distribution of leak densities (expressed as number of
leaks per hectare) have been compiled from 26 leak density values reported in
TetraTech (2001). The leak densities are based on liners installed with formal
Construction Quality Assurance (CQA) programs.
Use In EPACMTP
The EPACMTP model uses composite liner leak density to calculate the rate
of infiltration from composite-lined Sis (see Section 4.2). The calculated infiltration
rate is directly related to the leak density of the liner. A lower value of leak density
will result in a lower infiltration rate. A detailed description of the EPACMTP SI
2-23
-------
Section 2.0
Waste Management Unit (Source) Parameters
infiltration module is provided in Section 2.2.2.3 of the EPACMTP Technical
Background Document (U.S. EPA, 2003a).
2.4.8 Distance to Nearest Surface Water Body (RJ
Definition
The distance to the nearest permanent surface water body (that is, a river,
pond or lake); note that this distance can be measured in any direction, not only in
the downgradient direction.
Parameter Value or Distribution of Values
The data from the Surface Impoundment Study indicated a distribution of
values with a range of 30 m to 5,000 m (up to 3.1 miles), and a median value of 360
m. The entire distribution is presented in Appendix D for this parameter. The
cumulative frequency distribution is summarized in Table 2.8. For a given percentile
(%) frequency and value pair in this table, the percentile denotes the relative
frequency or likelihood of parameter values in the entire distribution being less than
or equal to the corresponding parameter value in the right-hand column.
Table 2.8 Cumulative Frequency Distribution of Distance to Nearest Surface
Water Body.
%
0
10
25
50
75
80
85
90
95
100
Distance to Nearest Surface Water
O.OOE+OO
9.00E+01
2.40E+02
3.60E+02
8.00E+02
1.17E+03
1.60E+03
5.00E+03
5.00E+03
5.00E+03
Body (m)
Data Sources
Data from the EPA's Surface Impoundment Study (EPA, 2001 a) were used
to assign a distance value to each SI unit in the default EPACMTP database of
WMU sites.
2-24
-------
Section 2.0 Waste Management Unit (Source) Parameters
Use In EPACMTP
In the case of deep unlined impoundments, EPACMTP may calculate very
high SI infiltration rates. EPACMTP checks against the occurrence of excessively
high rates by calculating the estimated height of groundwater mounding underneath
the WMU, and if necessary reduces the infiltration rate to ensure the predicted water
table does not rise above the ground surface. The infiltration screening
methodology is described in detail in Section 2.2.5 of the EPACMTP Technical
Background Document (EPA, 2003a). This screening procedure requires as input
the distance to the nearest point at which the water table elevation is kept at a fixed
value. Operationally, this is taken to be the distance to the nearest surface water
body.
2.4.9 Surface Impoundment Leaching Duration (tr)
Definition
The time period during which leaching from the SI unit occurs. For Sis, the
addition and removal of waste during the operational life period are assumed t be
more or less balanced, without significant net accumulation of waste. Additionally,
industrial Sis are, at the end of their operational life, typically dredged and backfilled.
Even if simply abandoned, the waste in the impoundment will drain and/or evaporate
relatively quickly. Consequently, in the finite source implementation for Sis, the
duration of the leaching period is assumed to be the same as the operational life of
the SI.
Parameter Value or Distribution of Values
In atypical SI modeling analysis, the SI is modeled as a temporary waste
management unit. In this case, if site-specific data are not available, the user can
make use of the distribution of SI operating life values summarized in Table 2.9 and
presented in their entirety in Appendix D. For a given percentile (%) frequency and
value pair in this table, the percentile denotes the relative frequency or likelihood of
parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right-hand column.
2-25
-------
Section 2.0
Waste Management Unit (Source) Parameters
Table 2.9 Cumulative Frequency Distribution of Surface Impoundment
Operating Life.
%
0
10
25
50
75
80
85
90
95
100
SI Operating Life
4.00E+00
1.50E+01
5.00E+01
5.00E+01
5.00E+01
5.00E+01
5.00E+01
5.00E+01
5.00E+01
9.50E+01
(yr)
Data Sources
Data used to define this nationwide distribution of unit-specific operational
lives for Sis were obtained from information in the Surface Impoundment Study on
present age of the unit and the planned closing date (EPA, 2001 a). If this
information was missing, we assigned an operational life of 50 years.
Use In EPACMTP
EPACMTP assumes that the duration of the leaching period is equal to the
unit's operational life; this leaching duration is then used to assign the length of the
pulse-source boundary condition in the EPACMTP fate and transport simulation.
2.5 WASTE PILE (WP)
This section discusses the individual WMU-related parameters required to
perform a WP analysis using EPACMTP. Most applications of EPACMTP are
conducted on a national or regional basis for regulatory development purposes, in
which case, most of the WP input parameters could be defined using a default
probability distribution, described in the following sections. However, EPACMTP can
also be used in a location- or waste-specific mode; in this case, each of the following
WP input parameters could be assigned a site-specific constant value or a site-
specific distribution of values. These site-specific data need to be gathered by the
user prior to performing the EPACMTP modeling analysis.
The WMU-specific input parameters for the WP scenario include the area of
the WP, the source leaching duration, and the depth of the base of the unit below
grade. Together with the leachate concentration, infiltration rate, and recharge rate,
these three parameters are used to determine how much contaminant mass enters
2-26
-------
Section 2.0
Waste Management Unit (Source) Parameters
the subsurface from the base of the WP over what time period. These WP input
parameters are described in the following sections.
2.5.1 Waste Pile Area (A...)
Definition
The WP area is defined as the footprint of the unit. In EPACMTP, the WP is
modeled as being rectangular. By default, the WMU is assumed to be square, i.e.,
equal length and width. Thus, the length and width of the WP are each calculated
as the square root of the area.
Parameter Value or Distribution of Values
The default nationwide distribution is presented in Appendix D. The
cumulative frequency distribution of WP area is summarized in Table 2.10. For a
given percentile (%) frequency and value pair in this table, the percentile denotes the
relative frequency or likelihood of parameter values in the entire distribution being
less than or equal to the corresponding parameter value in the right-hand column.
Table 2.10 Cumulative Frequency Distribution of Waste Pile Area.
%
0
10
25
50
75
80
85
90
95
100
Area (m2)
5.06E+00
2.02E+01
2.02E+01
1.21E+02
1.21E+03
2.02E+03
3.72E+03
4.17E+03
1.21E+04
1.94E+06
Data Sources
The data for WP area listed in Table 2.2 were obtained from EPA's 1986
Subtitle D Survey (U.S. EPA, 1986).
Use In EPACMTP
The WP area represents the total surface area over which infiltration and
leachate enter the subsurface.
2-27
-------
Section 2.0 Waste Management Unit (Source) Parameters
2.5.2 Waste Pile Leaching Duration (tr)
Definition
The time period during which leaching from the WP unit occurs. WPs are a
temporary management scenario in which the addition and removal of waste during
the operational life period are assumed to be more or less balanced, without
significant net accumulation of waste. Typically at the end of the active life of a WP,
the waste material is either removed for land filling, or the WP is covered and left in
place. If the waste is removed, there is no longer a source of potential
contamination. If a WP is covered and left in place, it then becomes equivalent to a
LF and should be regulated as a LF. Consequently, in the finite source
implementation for WPs, the duration of the leaching period will, for practical
purposes, be the same as the operational life of the WP.
Parameter Value or Distribution of Values
Since operational life is not one of the input parameters included in the EPA's
1986 Subtitle D Survey (U.S. EPA, 1986), EPA has assumed a value of 20 years as
a default value for WP operational life. Alternatively, a distribution of values could
also be used.
Data Sources
The default value of 20 years is based on professional judgement of typical
industrial waste management practices and consistency with EPA regulatory
assessments of the active life of a unit.
Use In EPACMTP
EPACMTP assumes that the duration of the leaching period is equal to the
unit's operational life; this leaching duration is then used to determine the total
contaminant flux from the WP to the subsurface.
2.5.3 Waste Pile Base Depth below Grade
Definition
This parameter represents the depth of the base of the unit below the ground
surface, as schematically depicted in Figure 2.6.
Parameter Value or Distribution of Values
Unless site-specific data are available, users should set this parameter to the
default value of zero, which is equivalent to assuming the base of the unit lies on the
ground surface.
2-28
-------
Section 2.0 Waste Management Unit (Source) Parameters
Data Sources
No survey data on this parameter are currently available. For WP modeling
analyses, this parameter value is typically set to a default value of zero.
Use In EPACMTP
Greater depth of the unit below the ground surface reduces the travel
distance through the unsaturated zone before leachate constituents reach ground
water. If a non-zero value is entered, EPACMTP will verify that the entered value, in
combination with the depth to the water table, and magnitude of the unit's infiltration
rate, does not lead to a physically infeasible condition (e.g., the WP base is in
contact with a static water table or an infiltration-induced watertable mound) in
accordance with the infiltration screening methodology presented in Section 2.2.5 of
the EPACMTP Technical Background Document (EPA, 2003a).
2.6 LAND APPLICATION UNIT (LAU)
This section discusses the individual WMU-related parameters required to
perform an LAU analysis using EPACMTP. Many applications of EPACMTP are
conducted on a national or regional basis for regulatory development purposes; in
which case, most LAU input parameters would be defined using the default
probability distributions described in the following sections. However, EPACMTP
can also be used in a location-adjusted or waste-specific mode; in this case, each of
the following LAU input parameters could be assigned a site-specific constant value
or a site-specific distribution of values. These site-specific data need to be gathered
by the user prior to performing the EPACMTP modeling analysis.
The WMU-specific input parameters for the LAU scenario include the area of
the LAU and the leaching duration. Together with the leachate concentration,
infiltration rate, and recharge rate, these two parameters are used to determine how
much contaminant mass enters the subsurface from the base of LAU and over what
time period. These LAU input parameters are described in the following sections.
2.6.1 Land Application Unit Area (Aw)
Definition
The LAU area is defined as the footprint of the unit. In EPACMTP, the LAU
is modeled as being rectangular. By default, the WMU is assumed to be square,
i.e., equal length and width. Thus, the length and width of the LAU are each
calculated as the square root of the area.
Parameter Value or Distribution of Values
The default nationwide distribution is presented in Appendix D. The
cumulative frequency distribution of LAU area is summarized in Table 2.11. For a
2-29
-------
Section 2.0
Waste Management Unit (Source) Parameters
given percentile (%) frequency and value pair in this table, the percentile denotes the
relative frequency or likelihood of parameter values in the entire distribution being
less than or equal to the corresponding parameter value in the right-hand column.
Table 2.11 Cumulative Frequency Distribution of Land Application Unit Area.
%
0
10
25
50
75
80
85
90
95
100
Area (m2)
2.02E+01
4.05E+01
4.05E+03
4.05E+04
1.82E+05
2.43E+05
4.05E+05
6.48E+05
9.11E+05
8.09E+07
Data Sources
The data for LAU area summarized in Table 2.11 were obtained from EPA's
1986 Subtitle D Survey (U.S. EPA, 1986).
Use In EPACMTP
The LAU area represents the total surface area over which infiltration and
leachate enter the subsurface.
2.6.2 Land Application Unit Leaching Duration (tr)
Definition
The time period during which leaching from the LAU occurs. Since LAUs are
typically modeled as temporary waste management units using the pulse (or non-
depleting) source scenario, this input is equivalent to the operational life. For LAUs,
the addition and removal of waste (via leaching, biodegradation, etc.) during the
operational life usually are assumed to be more or less balanced, without significant
net accumulation of waste. Once waste application ceases at the end of the
operational life of the LAU, the leachable waste is expected to be rapidly depleted.
Consequently, if the LAU is modeled as a finite source, the duration of the leaching
period will, in most cases be the same as the operational life of the LAU.
2-30
-------
Section 2.0 Waste Management Unit (Source) Parameters
Parameter Value or Distribution of Values
Since operational life is not one of the input parameters included in the EPA's
1986 Subtitle D Survey (U.S. EPA, 1986), EPA has assumed a value of 40 years as
a default value for LAU operational life. Alternatively, a distribution of values could
also be used.
Data Sources
The default value of 40 years is based on professional judgement of typical
industrial waste management practices and consistency with existing EPA regulatory
assessments on the active life of these units.
Use In EPACMTP
The leaching duration is used to determine the total contaminant flux from
the LAU to the subsurface.
2-31
-------
Section 3.0 Waste and Constituent Parameters
3.0 WASTE AND CONSTITUENT PARAMETERS
This section discusses the individual waste and constituent parameters
required to perform a modeling analysis using EPACMTP. Each of the input
parameters describing the waste and constituent can be specified as a constant
value or as a statistical or empirical distribution of values. As a practical matter,
however, many of these inputs are commonly set to constant values.
When modeling a WMU using a pulse source term (typically done for the SI,
WP, and LAU scenario), the only waste-specific input parameter required by the
model is the leachate concentration. When modeling a LF, the waste volume, waste
density and the waste concentration are also needed by the model (For a complete
listing of the LF source term variables, see Section 2.2.1 of the EPACMTP Technical
Background Document). These additional waste parameters are used to determine
the amount of constituent in the landfill that is available for leaching. The waste
volume is entered in EPACMTP in terms of a fraction of the entire LF volume, and is
discussed in Section 2 of this document, under the source parameters.
The constituent-specific parameters are used to simulate the chemical fate of
constituents as they are transported through the subsurface; these inputs can be
divided into three categories:
1) General and Constitutive Input Parameters
e.g., molecular weight, molecular diffusion, and regulatory
standard in drinking water.
2) Organic Constituent Specific Input Parameters
to describe the tendency of the constituent to degrade to form
harmless and/or toxic degradation products; and
to quantify the capacity of the constituent to adsorb to the
organic components of the soil matrix.
3) Non-Linear Metal Constituent Geochemical Input Parameters
to determine the mobility of a metal constituent in the
subsurface.
The EPACMTP model simulates the ground-water fate and transport of
waste constituents by using these constituent-specific parameters in conjunction
with the properties of the subsurface.
The waste and constituent parameters are individually described in the
following sections.
3-1
-------
Section 3.0
Waste and Constituent Parameters
3.1 WASTE AND CONSTITUENT PARAMETERS
The input parameters used in EPACMTP to describe the modeled waste and
constituent are listed in Table 3.1.
Table 3.1 Waste and Constituent Parameters
Parameter
Type
CD
1
All Constituents
Organic Constituents
Transformation Products
Parameter
Waste Density
Waste Concentration
(cone, of constituent in
Waste)
Leachate Concentration
(cone, of constituent in
leachate)
Molecular Diffusion
Coefficient
Drinking Water Standard
Molecular Weight
Organic Carbon Partition
Coefficient
Dissolved Phase
Hydrolysis Decay Rate
Sorbed Phase Hydrolysis
Decay Rate
Acid-Catalyzed
Hydrolysis Rate Constant
Neutral Hydrolysis Rate
Constant
Base-Catalyzed
Hydrolysis Rate Constant
Hydrolysis Reference
Temperature
Degradation Species
Number
Number of Immediate
Parents
Species Number of
Immediate Parent
Speciation Factor
Symbol
Phw
cw
CL
DI
DWS
MW
koc
A
4
K."
KnTr
KTr
Kb
Tr
e
M,
m,
Sim
Units
g/cm3
mg/kg
mg/L
m2/yr
mg/L
g/mol
cm3/g
1/yr
1/yr
1/(mol.yr)
1/yr
1/(mol.yr)
°C
unitless
unitless
unitless
unitless
Section
3.2.1
3.2.2
3.2.3
3.3.1.1
3.3.1.2
3.3.1.3
3.3.2.1
3.3.2.2.1
3.3.2.2.2
3.3.2.2.3
3.3.2.2.4
3.3.2.2.5
3.3.2.2.6
3.3.2.3.1
3.3.2.3.2
3.3.2.3.3
3.3.2.3.4
Equation
in
EPACMTP
TBD
2.3
2.3
2.1
3.15
4.37
2.29
3.13
3.13
4.31
4.31
4.31
4.31
3-2
-------
Section 3.0
Waste and Constituent Parameters
Table 3.1 Waste and Constituent Parameters (continued)
Parameter
Type
I Constituents
m
"CD
^
Parameter
Metal Identification
Number
Soil and Aquifer pH
Iron Hydroxide Content
Leachate Organic Acid
Concentration
Percent Organic Matter
Fraction Organic Carbon
Ground-water Type
(carbonate/
non-carbonate)
Symbol
ID
PH
FeOx
LOM
%OM
foe
IGWT
Units
unitless
standard
units
wt % Fe
mol/L
unitless
unitless
unitless
Section
3.3.3.2.1
3.3.3.2.2
3.3.3.2.3
3.3.3.2.4
3.3.3.2.5
3.3.3.2.6
3.3.3.2.7
Equation
in
EPACMTP
TBD
Section
G.4.1.2
(Appendix G)
Section
G.4.1.2
(Appendix G)
Section
G.4.1.2
(Appendix G)
Section
G.4.1.2
(Appendix G)
Section
G.4.1.2
(Appendix G)
Section
G.4.1.2
(Appendix G)
Section
G.4.1.2
(Appendix G)
3.2 WASTE CHARACTERISTICS
3.2.1 Waste Density (o.,...)
Definition
The waste density is defined as the average wet bulk density of the waste,
i.e., mass of waste per unit volume (kg/L or g/cm3) containing the constituent(s) of
concern and should be measured on the waste as disposed, as opposed to a dry
bulk density. This parameter is only used when modeling landfills.
Parameter Value or Distribution of Values
Information on the density of hazardous waste was developed using the
densities of 4 major categories of waste (solvents, paints, petroleum products,
pesticides) and their contributions to the composition of hazardous wastes in Subtitle
D landfills (Schanz and Salhotra, 1992). The results are expressed as an empirical
distribution of waste densities, given in Table 3.2. The default distribution shows a
relatively narrow range of variation, from 0.7 to 2.1 g/cm3.
3-3
-------
Section 3.0
Waste and Constituent Parameters
For waste-specific applications of EPACMTP, it is recommended to use
appropriate waste-specific data, rather than the default distribution.
Table 3.2 Default Cumulative probability distribution of waste density
Waste Density (g/cm3)
0.7
0.9
1.12
1.13
1.28
1.30
1.33
1.34
1.36
1.46
1.50
1.62
1.63
1.64
1.65
2.10
Cumulative Probability
0
0.530
0.550
0.551
0.553
0.640
0.728
0.815
0.826
0.904
0.905
0.906
0.994
0.995
0.996
0.998
Data Sources
The default data presented in Table 3.2 were developed by Schanz and
Salhotra(1992).
Use In EPACMTP
When modeling a landfill, the EPACMTP model uses the waste density to
convert between waste volume and mass; the total mass of the waste in the landfill
is then used in conjunction with the waste concentration to derive the contaminant
mass available to be leached to the subsurface.
3.2.2 Concentration of Constituent in the Waste (Cw)
Definition
The waste concentration (mg/kg) represents the total fraction of constituent
in the waste which may eventually leach out. Strictly speaking, Cw is the total
leachable waste concentration. However, from a practical perspective, Cw may be
interpreted to represent the total waste concentration and measured accordingly.
This approach will be protective because the measured total waste concentration
should always be at least as high as the more difficult to quantify "leachable" waste
concentration.
3-4
-------
Section 3.0 Waste and Constituent Parameters
The waste concentration used by EPACMTP reflects the average
concentration of the constituent(s) of concern in the waste in the WMU at the time of
closure. Contaminant losses that may occur during the WMU's active life are not
explicitly modeled in EPACMTP. If such losses are significant, it may be appropriate
to adjust the waste concentration accordingly (see Section 3.2.4) to represent the
remaining constituent concentration available for leaching. However, ignoring these
other loss pathways will be protective for the ground-water pathway analysis.
Parameter Value or Distribution of Values
The waste concentration is waste- and constituent-specific. There is no
default value or distribution for this parameter.
Data Sources
There is no default value or distribution for this parameter. Waste-specific
data should be obtained from appropriate chemical analytical tests on the waste of
interest.
Use In EPACMTP
EPACMTP uses the waste concentration to calculate the contaminant mass
within the landfill; the contaminant mass is an important input for determining the
landfill leaching duration (see Section 2.2.1.3.3 of the EPACMTP Technical
Background Document; U.S. EPA, 2003a).
3.2.3 Concentration of Constituent in the Leachate (CL)
Definition
The leachate concentration (mg/L) is the mass of the dissolved constituent
per unit volume of water emanating from the base of the WMU. This parameter
provides the boundary condition for the EPACMTP simulation of constituent fate and
transport through the unsaturated and saturated zone. For a continuous or pulse
source, this concentration is constant until leaching stops. For the landfill depleting
source option, the initial leaching concentration value must be provided by the user
as an EPACMTP input parameter; the model then automatically adjusts the value as
the waste is depleted during the simulation.
Parameter Value or Distribution of Values
The leachate concentration is waste- and constituent-specific. There is no
default value or distribution for this parameter.
EPACMTP can accommodate a measured value or distribution of values, as
determined from an appropriate leaching test procedure such as the Toxicity
3-5
-------
Section 3.0 Waste and Constituent Parameters
Characteristic Leaching Procedure (TCLP) or the Synthetic Precipitation Leaching
Procedure.1
If EPACMTP is used to back-calculate a loading or leaching risk-based or
regulatory limit for organic constituents (that is, the DAF is the only required model
output), then the leachate concentration value that is used as an EPACMTP input is
not material and an arbitrary value, such as 1 x 106 mg/L, can be used. However, if
a forward risk analysis is being performed for an organic constituent (when the
magnitude of the receptor well concentration is being determined to calculate risk),
then actual analytical concentration(s) is/are used as input to the EPACMTP model.
On the other hand, if the constituent of interest is a metal or inorganic with a
nonlinear sorption isotherm, then the actual value of the leachate concentration is
material to the analysis, no matter if the goal is to calculate risk based on the
resulting receptor well concentration (a forward risk calculation) or to determine a
threshold waste or leachate concentration based on a defined risk level (a backward
risk calculation). The reason for this is that the nonlinear isotherms which can be
used to model the adsorption of metals mean that there is a nonlinear relationship
between the input leachate concentration and the resulting receptor well
concentration. That is, for metals, we can't calculate a DAF that is constant across
all leachate concentrations. So, even when the goal of the analysis is to determine
an allowable threshold concentration for a metal constituent (a backward risk
calculation), the leachate concentration is an important model input. Such an
analysis will typically require repeated simulations, each with a different leachate
concentration, until the leachate concentration is identified that results in the
receptor well concentration being equal to a given regulatory or risk-based
benchmark concentration. Additionally, when we perform an EPACMTP analysis for
use in a forward risk calculation for metal constituents, actual analytical
concentrations are typically used as input to the EPACMTP model to determine the
resulting risk.
1
Remember that the DAF is calculated by dividing the input leachate concentration by the resulting receptor well concentration. Since
the ground-water transport for organic constituents is linear, if all other model inputs are held constant and the input leachate
concentration is doubled, the receptor well concentration will be doubled - but the DAF will remain the same. For this reason, if
EPACMTP is being used to back-calculate a threshold waste or leachate concentration, the input leachate concentration for an organic
constituent is arbitrary. The value of 1 x 106 mg/L is commonly used for this arbitrary concentration simply because its large value
makes insignificant any errors due to numerical oscillations in the transport solution.
3-6
-------
Section 3.0 Waste and Constituent Parameters
Data Sources
The waste concentration is waste- and constituent-specific. There is no
default value or distribution for this parameter.
Use In EPACMTP
The EPACMTP fate and transport model requires stipulation of the leachate
concentration as a function of time, CL(t). The leachate concentration CL(t) used in
the model directly represents the concentration of the leachate emanating from the
base of the waste management unit, as a boundary condition for the numerical fate
and transport model. EPACMTP accounts for time variation as either a constant
concentration pulse condition, or as an exponentially decreasing leachate
concentration (depleting source).
In the finite source option, the simplest and generally most conservative case
is to assume that the leachate concentration remains constant until all of the initially
present contaminant mass has leached out of the disposal unit. This case is
referred to as the pulse (or non-depleting) source scenario. The boundary condition
for the fate and transport model then becomes a constant concentration pulse, with
defined duration.
A more realistic modeling analysis in the case of a closed landfill with no
continued waste addition to the unit, can be conducted by assuming that linear
equilibrium partitioning between the solid and liquid phase of the waste leads to an
exponential decrease in the leachate concentration over time as a result of depletion
of the source. When using this depleting source option, the user specifies the initial
leaching concentration, and the model automatically adjusts this rate over time
(except for organics with nonlinear isotherms) as explained in Section 2.2.1.3.3 of
the EPACMTP Technical Background Document (U.S. EPA, 2003a).
3.3 CONSTITUENT PHYSICAL AND CHEMICAL CHARACTERISTICS
3.3.1 All Constituents
The molecular diffusion coefficient and the molecular weight are constituent-
specific inputs required by the model for all types of constituents and modeling
analyses. In addition, if a finite source analysis is performed, then a value is
required for the applicable drinking water standard for each constituent.
EPACMTP also accounts for constituent-specific transformation and sorption
processes. These are discussed in Sections 3.3.2 and 3.3.3 for organic and metal
constituents, respectively.
3-7
-------
Section 3.0 Waste and Constituent Parameters
3.3.1.1 Molecular Diffusion Coefficient (D,)
Definition
Diffusion is defined as the movement of constituent molecules in an
environmental medium from areas of high constituent concentrations toward areas
with lower constituent concentrations. This process occurs as a result of
concentration gradients. Diffusion can occur both in the absence or presence of
advective flow. In ground-water flow systems, the process of diffusion is quantified
using the diffusion coefficient of the constituent and the concentration gradient of the
constituent in ground water.
The coefficient of molecular diffusion is often negligible compared to the
dispersivity term in the calculation of the dispersion coefficient and is commonly
ignored. However, diffusion can be significant in cases where ground-water velocity
is very low.
Parameter Value or Distribution of Values
The molecular diffusion coefficient is a constituent-specific input parameter
and should be calculated by the user based on the molecular diffusion coefficient in
free water. Molecular diffusion coefficient values for some common organic
constituents are included in Appendix C. If data are not available for the modeled
constituent, this parameter should be set to zero.
Data Sources
The molecular diffusion coefficient values listed in Appendix C were
generated using the Water 9 model (U.S. EPA, 2001 b).
Use In EPACMTP
Hydrodynamic dispersion and molecular diffusion are used to calculate the
dispersion coefficient, one of the variables in the transport equation (see Section 4.4
of the EPACMTP Technical Background Document, U.S. EPA, 2000a).
3.3.1.2 Drinking Water Standard (DWS)
Definition
The drinking water standard (mg/L) is the level assumed to be protective. It
may be a Maximum Contaminant Level (MCL) or a health-based number (HBN)
(See Section 5.0 of the IWEM Technical Background Document, U.S. EPA, 2003c)
3-8
-------
Section 3.0 Waste and Constituent Parameters
Parameter Value or Distribution of Values
The drinking water standard is a constituent-specific input parameter; the
appropriate value must be determined by the user. The default value for this
parameter is zero. The drinking water standard must be expressed in the same units
used for the leachate concentration, usually mg/L. Although a distribution of values
could be used for this input parameter, it is typically specified as a constant value.
Data Sources
Current values for MCLs can be obtained from the EPA's Office of Ground
Water and Drinking Water (http://www.epa.gov). See Section 5 of the IWEM
Technical Background Document, U.S. EPA, 2003c for a discussion of sources for
HBN values.
Use In EPACMTP
The drinking water standard is used in finite source scenarios when the
depleting landfill source option is invoked to determine the duration of the
exponentially decaying concentration boundary condition (tp). Leaching is assumed
to continue until the constituent concentration in the leachate has dropped below the
drinking water standard. The leaching duration, tp, is determined by setting Equation
2.12 in the EPACMTP Technical Background Document (U.S. EPA, 2003a) equal to
the DWS and solving fort (time).
3.3.1.3 Molecular Weight (MW)
Definition
The molecular weight (g/mol) is defined as the amount of mass in one mole
of molecules of a constituent as determined by summing the atomic weights of the
elements in that constituent, multiplied by their stochiometric factors.
Parameter Value or Distribution of Values
The molecular weight is a constituent-specific input parameter; the
appropriate value must be provided by the user. There is no default value.
Data Sources
Compilations of chemical data such as molecular weight are available on
many web sites and in most chemistry reference books.
Use In EPACMTP
The use of this parameter is reserved for future versions of EPACMTP to
automatically calculate the parent to degradation product yield or decay coefficients
for chain decay simulations.
3-9
-------
Section 3.0 Waste and Constituent Parameters
3.3.2 Organic Constituents
This section describes the parameters used in EPACMTP for organic
constituents. The parameters to be discussed are the organic carbon partition
coefficient, sorbed and dissolved phase hydrolysis decay rate, acid, neutral, and
base-catalyzed hydrolysis rate constants, and the reference temperature.
For organic constituents, EPACMTP takes into account adsorption behavior
of organic constituents by calculating a retardation factor based on the organic
carbon distribution coefficient (koc) of each constituent and fractional organic carbon
in the soil (foc) (See Section 3.2.1).
In order to model the subsurface fate and transport of organic constituents,
EPACMTP generates a single first-order degradation rate, which includes both
biodegradation and chemical hydrolysis (in both sorbed and dissolved phases). The
biodegradation rate is typically set to zero (due to the difficulty in accurately
estimating it), but a non-zero value can be specified by the user. The user can
directly specify the hydrolysis rates, or they can be internally calculated by the model
(see Section 3.3.2.2). If calculated, EPACMTP requires that the hydrolysis rate
constants and the reference temperature at which they were measured be specified
. EPACMTP then uses these rate constants along with the ground-water
temperature and pH to derive the sorbed-phase and dissolved-phase hydrolysis
rates. These two hydrolysis rates and the biodegradation rate (if non-zero) are then
combined into the overall first-order degradation rate. If the products of this
degradation are themselves toxic, they can be included in the modeling analysis by
specifying them to be part of a decay chain, with the current organic constituent as
the parent chemical.
If desired, the user can override the default of no biodegradation, by
providing appropriate values of the biodegradation rate coefficient for the
unsaturated and saturated zone (see Section 5 of this document).
3.3.2.1 Organic Carbon Partition Coefficient (IO
Definition
The organic carbon partition coefficient (cm3/g) is the ratio of a constituent's
concentration in a theoretical soil containing only organic carbon to its concentration
in the ground water. Thus, koc describes the affinity of a constituent to attach itself to
organic carbon. This parameter is applicable to organic constituents which tend to
sorb onto the organic matter in soil or in an aquifer. Constituents with high koc
values tend to move more slowly through the soil and ground water. Volatile
organics tend to have low koc values, whereas semi-volatile organics often have high
koc values.
3-10
-------
Section 3.0 Waste and Constituent Parameters
Parameter Value or Distribution of Values
The organic carbon partition coefficient is a constituent-specific input
parameter; values for some common organic constituents are included in Appendix
C. Although commonly specified as a constant value, this parameter can also be
specified as a distribution of values. If constituent-specific data for the organic to be
modeled are not available, this input value can be set to zero - a value that means
the constituent's ground-water concentration will not be decreased due to
adsorption.
Data Sources
Organic carbon partition coefficient (koc) values can be obtained from many
constituent property handbooks, as well as online databases, (e.g., Kollig, Ellington,
Karickhoff, Kitchens, Long, Weber and Wolfe, 1993 or Handbook of Environmental
Data on Organic Constituents, Verschueren, 1983). Sometimes, these references
provide an octanol-water partition coefficient (kow), rather than a koc value. These
two coefficients are roughly equivalent parameters. A number of conversion
formulas exist to convert kow values into koc; these can be found in handbooks on
environmental fate data (e.g., Verschueren, 1983; Kollig et. al., 1993). This
conversion factor accounts for the mass difference, expressed as a percentage,
between pure organic carbon and natural organic matter which also includes
elements in addition to carbon (Enfield, Carsel, Cohen, Phan and Walters, 1982).
Different conversion formulas exist for different constituents and environmental
media, and there is no single formula that is valid for all organic constituents;
therefore, the conversion formula should be chosen and used with some caution.
Use In EPACMTP
For organic constituents, the effect of equilibrium sorption is expressed in
EPACMTP through the retardation coefficient, R, which is a function of the chemical-
specific organic carbon partition coefficient, koc:
R = 1 + J^ (3.-|)
where
If — f • If /O O\
Kd ~ Toc Koc (3.2)
where
R = retardation coefficient for species i (dimensionless)
pb = soil bulk density for the unsaturated zone (g/cm3)
9 = soil water content (dimensionless)
kd = soil-water partition coefficient (L/kg)
foc = fractional organic carbon content in the soil or aquifer
(unitless)
koc = organic carbon partition coefficient (cm3/g)
3-11
-------
Section 3.0 Waste and Constituent Parameters
The fractional organic carbon can be estimated from the percentage organic
matter (%OM) in the soil or aquifer, as
f =
'oc
where
%OM = percent organic matter in the soil (unitless)
1 74 = conversion factor
3.3.2.2 Parameters Related to Chemical Hydrolysis
The transport of organic constituents can be influenced in part by chemical
hydrolysis, a process that is represented in the EPACMTP model by means of an
overall first-order chemical decay coefficient. This overall decay coefficient includes
both dissolved phase and sorbed phase decay. Dissolved phase and sorbed phase
decay rates can be specified directly, or they can be derived based on chemical-
specific hydrolysis rate constants and the ground-water temperature and pH. In the
latter case, the hydrolysis rate constants for each constituent can be obtained from
reference documents compiled by EPA's Environmental Research Laboratory in
Athens, GA (U.S. EPA, 1993 and Kollig et al., 1993).
The hydrolysis process as modeled in EPACMTP is affected by aquifer pH,
aquifer temperature, and constituent sorption:
The overall first-order transformation rate for hydrolysis is calculated as:
A - MIMA ,3.4)
where:
A = Overall first-order hydrolysis transformation rate (1/yr)
A, = Dissolved phase hydrolysis transformation rate (1/yr);
see Section 3.3.2.2.1
A2 = Sorbed phase hydrolysis transformation rate (1/yr); see
Section 3.3.2.2.2
$ = Porosity (water content in the unsaturated zone)
(dimensionless)
pb = Bulk density (kg/L)
kd = Partition coefficient (L/kg)
The calculation of the sorbed phase and dissolved phase hydrolysis rates
from the hydrolysis rate constants is described in the following sections.
3-12
-------
Section 3.0 Waste and Constituent Parameters
3.3.2.2.1 Dissolved Phase Hydrolysis Decay Rate (A-,)
Definition
Hydrolysis is defined as the decomposition of organic constituents by
interaction with water. The dissolved phase hydrolysis decay rate (1/yr) is the rate at
which the dissolved portion of the contaminant mass is hydrolyzed.
Parameter Value or Distribution of Values
The dissolved phase hydrolysis decay rate can be directly input by the user
(as either a constant value or distribution of values) or it can be set to be internally
derived by the model. In the latter case, it is calculated as follows:
\, = KaT [H + ] + KnT + KbT [OH'] (3.5)
where
A, = First-order decay rate for dissolved phase (1/yr)
Kj,Kj,Kfr = Hydrolysis rate constants; calculated as described in Sections
3.3.2.2.3, 3.3.2.2.4, and 3.3.2.2.5
[H+] = Hydrogen ion concentration (mole/L)
[Ohf] = Hydroxyl ion concentration (mole/L)
[H+] and [Off] are computed from the pH of the soil or aquifer using
[H+]=10-pH
Data Sources
In the absence of site-specific data, this parameter typically is set to be derived
by the model based on the constituent-specific hydrolysis rate constants (see Sections
3.3.2.2.3 through 3.3.2.2.6).
Use In EPACMTP
The dissolved phase hydrolysis rate is used to calculate the overall first-order
transformation rate for hydrolysis as presented in Equation 3.4.
3-13
-------
Section 3.0 Waste and Constituent Parameters
3.3.2.2.2 Sorbed Phase Hydrolysis Decay Rate f/U
Definition
Hydrolysis is defined as the decomposition of organic constituents by interaction
with water. The sorbed phase hydrolysis decay rate (1/yr) is the rate at which the
sorbed portion of the contaminant mass is hydrolyzed.
Parameter Value or Distribution of Values
The sorbed phase hydrolysis decay rate can be directly input by the user (as
either a constant value or distribution of values) or it can be set to be internally derived
by the model. If it is specified in the input file as derived by EPACMTP, the effective
sorbed phase decay rate is calculated as:
[An + KnT (3.6)
where:
A2 = First-order hydrolysis rate for sorbed phase (1/yr)
K^ = Acid-catalyzed hydrolysis rate constant (1/mole/yr); see Section
3.3.2.2.3
K^ = Neutral hydrolysis rate constant (1/yr); see Section 3.3.2.2.4
10 = Acid-catalyzed hydrolysis enhancement factor
[H+] = Hydrogen ion concentration (computed from the pH of the soil or
aquifer using [H+] = 10-pH)
Data Sources
In the absence of site-specific data, this parameter typically is set to be derived
by the model based on the constituent-specific hydrolysis rate constants (see Sections
3.3.2.2.3 through 3.3.2.2.6).
Use In EPACMTP
The sorbed phase hydrolysis rate is used to calculate the overall first-order
transformation rate for hydrolysis as presented in Equation 3.4.
3.3.2.2.3 Acid-Catalvzed Hydrolysis Rate Constant (K^)
Definition
The tendency of a constituent to hydrolyze is expressed through several
constituent-specific rate constants. The acid-catalyzed rate constant (1/mol-yr) is one
of the values that is used to quantify how the rate of the hydrolysis reaction is affected
3-14
-------
Section 3.0 Waste and Constituent Parameters
by the pH (specifically at the acidic end of pH) of the subsurface. The superscript Tr
indicates that the value is measured at a specified reference temperature.
Parameter Value or Distribution of Values
The acid-catalyzed rate constant is a constituent-specific input parameter;
values for some common organic constituents are included in Appendix C. Although
commonly specified as a constant value, this parameter can also be specified as a
distribution of values. If constituent-specific data for the organic to be modeled are not
available, this input value can be set to zero - a conservative value that means the
constituent's ground-water concentration will not be decreased due to chemical
hydrolysis at the acidic end of the scale. However, if the modeled constituent
hydrolyzes to form one or more toxic degradation products, then setting this input to
zero and not modeling the formation of the toxic degradation product could result in an
underestimation of the risk of exposure via the ground-water pathway.
Data Sources
(Kjr) values can be obtained from some constituent property handbooks (e.g.,
Kollig et al, 1993 or Handbook of Environmental Data on Organic Constituents,
Verschueren, 1983).
Use In EPACMTP
The acid-catalyzed hydrolysis rate constant is influenced by ground-water
temperature, while acid- and base catalyzed rate constants are also influenced by pH.
As shown below, the Arrhenius equation is used to convert the input hydrolysis rate
constants, measured at a specified reference temperature (Tr), to the actual
temperature of the subsurface:
K,T = Kjr exp [EJRJ
j J ^ L a gv
7+ 273
K.J = Hydrolysis rate constant for reaction process J, corrected for the
subsurface temperature Tr (1/mol-yr for the acid- and base-
catalyzed reactions; 1/yr for the neutral reaction)
Kjr = Hydrolysis rate constant for reaction process J, measured at
reference temperature T (1/mol-yr for the acid- and base-catalyzed
reactions; 1/yr for the neutral reaction)
J = a for the acid-catalyzed reaction, bfor base-catalyzed reaction, and
n for the neutral reaction
T = Temperature of the subsurface (°C)
Tr = Reference temperature (°C)
Rg = Universal gas constant (1.987E-3 Kcal/deg-mole)
Ea = Arrhenius activation energy (Kcal/mole)
3-15
-------
Section 3.0 Waste and Constituent Parameters
Note that, using the generic activation energy of 20 Kcal/mole recommended by
Wolfe (1985), the factor EJRg has a numerical value of 10,000.
The temperature-corrected rate constants are then used in Equations 3.5 and
3.6 to calculate the sorbed phase and dissolved phase hydrolysis rate constants from
which the overall hydrolysis transformation rate is calculated. The overall first-order
transformation rate is one of the parameters required to solve the advection-dispersion
equation (see Sections 3.3.4 and 4.4.4 of the EPACMTP Technical Background
Document (U.S. EPA, 2003a)).
3.3.2.2.4 Neutral Hydrolysis Rate Constant (K*r)
Definition
The tendency of a constituent to hydrolyze is expressed through several
constituent-specific rate constants. The neutral rate constant (1/yr) is used to quantify
how the rate of the hydrolysis reaction is unaffected by the pH of the subsurface. The
superscript Tr indicates that the value is measured at a specified reference temperature.
Parameter Value or Distribution of Values
The neutral rate constant is a constituent-specific input parameter; values for
some common organic constituents are included in Appendix C. Although commonly
specified as a constant value, this parameter can also be specified as a distribution of
values. If constituent-specific data for the organic to be modeled are not available, this
input value can be set to zero - a conservative value that means the constituent's
ground-water concentration (under pH neutral conditions) will not be decreased due to
chemical hydrolysis. However, if the modeled constituent hydrolyzes to form one or
more toxic degradation products, then setting this input to zero and not modeling the
formation of the toxic degradation product could result in an underestimation of the risk
of exposure via the ground-water pathway.
Data Sources
K^r values can be obtained from some constituent property handbooks (e.g.,
Kollig et al, 1993 or Handbook of Environmental Data on Organic Constituents,
Verschueren, 1983).
Use In EPACMTP
As shown in Equation 3.7, the Arrhenius equation is to used convert the input
hydrolysis rate constants, measured at a specified reference temperature (Tr), to the
actual temperature of the subsurface. The temperature-corrected rate constants are
then used in Equations 3.5 and 3.6 to calculate the sorbed phase and dissolved phase
hydrolysis rate constants from which the overall hydrolysis transformation rate is
calculated. The overall first-order transformation rate is one of the parameters required
to solve the advection- dispersion equation (see Sections 3.3.4 and 4.4.4 of the
EPACMTP Technical Background Document (U.S. EPA, 2003a)).
3-16
-------
Section 3.0 Waste and Constituent Parameters
3.3.2.2.5 Base-Catalyzed Hydrolysis Rate Constant (K^r)
Definition
The tendency of each constituent to hydrolyze is expressed through several
constituent-specific rate constants. The base-catalyzed rate constant (1/mol-yr) is one
of the values that is used to quantify how the rate of the hydrolysis reaction is affected
by the pH of the subsurface, in this case under more alkaline conditions. The
superscript Tr indicates that the value is measured at a specified reference temperature.
Parameter Value or Distribution of Values
The base-catalyzed rate constant is a constituent-specific input parameter;
values for some common organic constituents are included in Appendix C. Although
commonly specified as a constant value, this parameter can also be specified as a
distribution of values. If constituent-specific data for the organic to be modeled are not
available, this input value can be set to zero - a conservative value that means the
constituent's ground-water concentration will not be decreased due to chemical
hydrolysis at the alkaline end of the scale. However, if the modeled constituent
hydrolyzes to form one or more toxic degradation products, then setting this input to
zero and not modeling the formation of the toxic degradation product could result in an
underestimation of the risk of exposure via the ground-water pathway.
Data Sources
The K^r values can be obtained from some constituent property handbooks
(e.g., Kollig et al, 1993 or Handbook of Environmental Data on Organic Constituents,
Verschueren, 1983).
Use In EPACMTP
As shown in Equation 3.7, the Arrhenius equation is used to convert the input
hydrolysis rate constants, measured at a specified reference temperature (Tr), to the
actual temperature of the subsurface. The temperature-corrected rate constants are
then used in Equations 3.5 and 3.6 to calculate the sorbed phase and dissolved phase
hydrolysis rate constants from which the overall hydrolysis transformation rate is
calculated. The overall first-order transformation rate is one of the parameters required
to solve the advection-dispersion equation (see Sections 3.3.4 and 4.4.4 of the
EPACMTP Technical Background Document (U.S. EPA, 2003a)).
3.3.2.2.6 Reference Temperature (Tf)
Definition
The reference temperature (°C) is the temperature at which the input hydrolysis
rate constants were measured.
3-17
-------
Section 3.0 Waste and Constituent Parameters
Parameter Value or Distribution of Values
The chemical-specific hydrolysis rate constants are measured at a constant
reference temperature; the default value is 25 degrees Celsius.
Data Sources
Hydrolysis rate constants can be obtained from some constituent property
handbooks (e.g., Kollig et al, 1993 or Handbook of Environmental Data on Organic
Constituents, Verschueren, 1983). The data source used for the hydrolysis rate
constants should also state the temperature at which the values were measured.
Use In EPACMTP
As shown in Equation 3.7, the reference temperature is used in the Arrhenius
equation to convert the input hydrolysis rate constants to the actual temperature of the
subsurface. The temperature-corrected rate constants are then used in Equations 3.5
and 3.6 to calculate the sorbed phase and dissolved phase hydrolysis rate constants
from which the overall hydrolysis transformation rate is calculated. The overall first-
order transformation rate is one of the parameters required to solve the advection-
dispersion equation (see Sections 3.3.4 and 4.4.4 of the EPACMTP Technical
Background Document (U.S. EPA, 2003a)).
3.3.2.3 Parameters Related to Hydrolysis Transformation Products
In the event that the products of this chemical degradation process are toxic and
their constituent-specific parameters are known, they can be included in the simulation
by specifying them to be part of a transformation (or decay) chain. Note that when a
multi-species simulation such as this is performed, the necessary chemical-specific
parameters must be repeated for each species in the decay chain. In addition, the
following parameters are required for each degradation species in a decay chain
analysis: degradation product species number, number of immediate parents for each
degradation product species, species number(s) of immediate parent(s), and fraction
of the parent species that decays into the given degradation product species.
3.3.2.3.1 Degradation Product Species Number M
Definition
The degradation product species number is an index number that uniquely
identifies a constituent and its properties in EPACMTP.
Parameter Value or Distribution of Values
Degradation product species numbers begin with the number 2 (the parent
species number is 1). Up to 6 degradation products per parent are permitted in
EPACMTP (numbered 2-7).
3-18
-------
Section 3.0 Waste and Constituent Parameters
Data Sources
The degradation product species number is a construction of convenience for
EPACMTP, and as such, there are no data sources. The value of the parameter is
governed by the number of degradation products in a particular transformation chain.
Use In EPACMTP
The degradation product species number allows EPACMTP to track and
associate degradation products with its properties and relationships to its immediate
parent and daughters.
3.3.2.3.2 Number of Immediate Parents (Me)
Definition
The number of immediate parents (M() is defined as the total number of
individual species which degrade directly into degradation product species L This
parameter is used in EPACMTP together with the species number of the immediate
parent (see next section) to represent the structure of the chain decay reaction. The
value of this parameter is zero for the parent species and one for each degradation
product species. The maximum value of M, is one because the EPACMTP model can
handle simulation of only one constituent that has a non-zero initial leachate
concentration (that is, one original parent species per decay chain). For example, if
constituent A degrades into constituent B, and B degrades to C, then degradation
product B has one immediate parent (A) and degradation product C also has one
immediate parent (B).
Parameter Value or Distribution of Values
The number of immediate parent species is governed by the specific
transformation chain to be simulated using EPACMTP.
Data Sources
The number of immediate parent species is governed by the decay chain
reaction being simulated. Reaction chemistry or constituent property handbooks (e.g.,
Kollig et al, 1993, or Handbook of Environmental Data on Organic Constituents,
Verschueren, 1983) may contain chain decay structures for organic constituents.
Use In EPACMTP
The number of immediate parent species of a degradation product species
allows EPACMTP to track its relationships to its immediate parent.
3-19
-------
Section 3.0
Waste and Constituent Parameters
3.3.2.3.3 Species Numberfs) of Immediate Parentfs) (m, (i), i = 1, Mf)
Definition
The species number m,(i) of the immediate parent is the ordinal number (see
Section 3.3.2.3.1) of the toxic degradation product that directly degrades into the
degradation product of concern. For example, consider again the straight decay chain
where constituent A degrades into constituent B which degrades into constituent C
shown in the example below:
Parameter
Q
M«
m,(i)
Definition
species
number
number
(quantity) of
immediate
parents
species
number of
immediate
parent
Value for
Constituent A
1
0
0
Value for
Constituent B
2
1
1
Value for
Constituent C
3
1
2
Parameter Value or Distribution of Values
The species number of immediate parent species is governed by the specific
decay chain to be simulated using EPACMTP and by the numbering system chosen by
the user.
Data Sources
The numbering of immediate parent species is governed by the decay chain
reaction being simulated and the user's discretion. Reaction chemistry or constituent
property handbooks (e.g., Kollig et al, 1993, or Handbook of Environmental Data on
Organic Constituents, Verschueren, 1983) may contain chain decay structures for
organic constituents.
Use In EPACMTP
The association of an immediate parent to a degradation product species
number allows EPACMTP to track and associate a degradation product with its
properties and relationships to its immediate parent and degradation products.
3-20
-------
Section 3.0 Waste and Constituent Parameters
3.3.2.3.4 Fraction of the Parent Species (£m)
Definition
The coefficient ^m is called the fraction of the parent species which expresses
how many units of species n are produced in the decay of each unit of parent m. The
value of the speciation factor is thus determined by the reaction stoichiometry, as well
as the units used to express concentration. For instance, consider the following
hydrolysis reaction in which 2 units of degradation product B and 1 unit of degradation
product C are formed from the hydrolysis of 3 units of parent A:
3A + 2H20 - 26 (OH)~ + 2H+ + C
where
A = parent compound A
H2O = water molecule
B = degradation product compound B
C = degradation product compound C
(OH)- = hydroxide ion
H+ = hydrogen ion
, , . , • ,2 Ml/l/o , . ,1 MWC
In this example, £BA is equal to —.,.., and £CA is equal to —
where
3MWA 3MWA
MWf = the molecular weight of species u (g/mol)
£BA = speciation factor between parent A and degradation product B
£CA = speciation factor between parent A and degradation product C
Parameter Value or Distribution of Values
The value of this parameter is determined by the species and reaction
stoichiometry and is constant for the entire simulation.
Data Sources
The fraction of parent species is governed by the stoichiometry of the decay
chain reaction being simulated and individual constituent properties. Reaction
chemistry or constituent property handbooks (e.g., Kollig et al, 1993, or Handbook of
Environmental Data on Organic Constituents, Verschueren, 1983) may contain chain
decay structures for organic constituents.
3-21
-------
Section 3.0 Waste and Constituent Parameters
Use In EPACMTP
EPACMTP uses the fraction of parent species to determine how much of a
parent species decays to form an immediate daughter. Similarly, the same factor is
used to determine how much degradation product species is produced from its
immediate parent. These relationships are applied in both the unsaturated and
saturated fate and transports simulations (see Equations 3.14 and 4.31, respectively
in the EPACMTP Technical Background Document, (U.S. EPA, 2003a)).
3.3.3 Metals
In the subsurface, metal constituents may undergo reactions with ligands in the
pore water and with surface sites on the solid aquifer or soil matrix material. Reactions
in which the metal is bound to the solid matrix are referred to as sorption reactions and
metal that is bound to the solid is said to be sorbed. The ratio of the concentration of
metal sorbed to the concentration in the mobile aqueous phase at equilibrium is referred
to as the partition coefficient (Kd). During contaminant transport, sorption to the solid
matrix results in retardation of the contaminant front. Thus, transport models such as
EPACMTP incorporate the contaminant partition coefficient into the overall retardation
factor (the ratio of the average linear particle velocity to the velocity of that portion of the
plume where the contaminant is at 50 percent dilution). The use of Kd in EPACMTP
transport modeling implies the assumption that local equilibrium between the solutes
and the sorbents is attained, meaning that the rate of sorption reactions is fast relative
to advective-dispersive transport of the contaminant.
Users can specify a constant value or distribution of values for the Kd (a linear
isotherm); alternatively, tables of non-linear sorption isotherms (for a suite of 21 metals,
some with varying oxidation states) or equations comprising pH-based (linear)
isotherms are available within EPACMTP. Both the non-linear isotherms and the pH-
based isotherms were developed especially for use with the EPACMTP model.
The pH-dependent isotherms were developed for 12 metals using the empirical
relationships as described in Loux, Chafin and Hassan (1990). These isotherms were
originally developed as an alternative to the MINTEQA2-derived isotherms (U.S. EPA,
1996 and 1999) because, at that time, there were limitations in the database of
adsorption reactions that made the MINTEQA2 modeling less accurate for metals that
form anions or neutral species in aqueous solution. However, ensuing improvements
in the MINTEQA2 database of adsorption reactions and modeling methodology have
resulted in a new set of non-linear isotherms which supercede the pH-based isotherms.
However, the option to use these pH-based isotherms is still available in the EPACMTP
model, and so they are described in this document.
The non-linear isotherms were estimated using the geochemical speciation
model, MINTEQA2, and are tabulated into auxiliary input files for use by the EPACMTP
model. These isotherms reflect the tendency of Kd to decrease as the total metal
concentration in the system increases. The non-linear isotherms available for use in
EPACMTP are specified in terms of the dissolved metal concentration and the
corresponding sorbed concentration at a series of total metal concentrations.
3-22
-------
Section 3.0 Waste and Constituent Parameters
For a particular metal, Kd values in a soil or aquifer are dependent upon the metal
concentration and various geochemical characteristics of the soil or aquifer and the
associated pore water. Geochemical parameters that have the greatest influence on
the magnitude of Kd include the pH of the system and the nature and concentration of
sorbents associated with the soil or aquifer matrix. In the subsurface beneath a
disposal facility, the concentration of leachate constituents may also influence Kd.
Although the dependence of metal partitioning on the total metal concentration and on
pH and other geochemical characteristics is apparent from partitioning studies reported
in the scientific literature, Kd values for many metals are not available for the range of
metal concentrations or geochemical conditions needed in risk assessment modeling.
For this reason, MINTEQA2 was used to estimate partition coefficients. The use of a
speciation model allows Kd values to be estimated for a range of total metal
concentrations in various model systems designed to depict natural variability in those
geochemical characteristics that most influence metal partitioning.
The development of these non-linear (concentration-dependent) metal partition
coefficients is described in Appendix B. 1. The following sections describe the available
options and the input parameters required to perform ground-water fate and transport
modeling of metal constituents using the EPACMTP model.
3.3.3.1 Empirical K^ Data
There are two sources of empirical Kd data that can be used to model metals
transport using linear isotherms: Kd data compiled from a recent comprehensive
literature survey and pH-based isotherms that are based on the empirical laboratory-
based data of Loux et al (1990). These two types of empirical Kd data are described
in the following sections.
3.3.3.1.1 Kj Data Compiled from a Literature Survey
In the absence of site-specific data, the distribution coefficient for metals can be
specified as a statistical or empirical distribution of values. A comprehensive literature
review of Kd values was conducted for the EPA's RCRA Hazardous Waste Listing
Determination for Inorganic Chemical Manufacturing Wastes (U.S. EPA, 2000). Forthis
project, Kd was defined as an empirical distribution of values when sufficient data were
available (six or more literature Kd values) or as a log uniform distribution of values
when fewer data were found in the scientific literature (five or fewer literature Kd values).
This literature review focused on identifying and compiling experimentally derived Kd
values for soil and aquifer materials from published literature. Collected values were
compiled along with geochemical and measurement parameters most likely to influence
Kd. Details of the literature search and data collection strategy are given in Appendix
I of the Risk Assessment for the Listing Determination for Inorganic Chemical
Manufacturing Wastes: Background Document (U.S. EPA, 2000) along with the
resulting distributions of Kd values.
If site-specific Kd data are unavailable, the EPACMTP user can specify that one
of these default distributions be used for the coefficient of the Freundlich isotherm for
the unsaturated and saturated zones. That is, the appropriate distribution, gleaned
3-23
-------
Section 3.0 Waste and Constituent Parameters
from (U.S. EPA, 2000), should be entered twice in the EPACMTP input file, once in the
unsaturated zone parameter group and again for the aquifer parameter group.
3.3.3.1.2 pH-based Isotherms
pH-dependent isotherms for 15 metal species were determined from empirical
relationships as described in Loux et al., 1990. Many of these metals form anions or
neutral species in aqueous solution (e.g., HAsO32~, H2AsO3", and H3AsO3°).
The pH-dependent empirical relationships were determined from linear least
squares analysis of laboratory measurements from aquifer materials and their
corresponding ground water and leachate samples collected from six municipal landfills,
as well as other published data. In these experiments, the concentrations of trace metal
contaminants in the ground-water/aquifer material samples were augmented with
additions (spikes), and the spiked samples were allowed to equilibrate for 48 hours.
After equilibration, the trace metal remaining in solution was measured. The difference
between the total trace metal in the system (the metal originally in the sample plus the
amount added) and the amount remaining in solution at equilibrium was regarded as
adsorbed. The distribution coefficient was determined as the ratio of amount of trace
metal adsorbed to the amount remaining in solution. The resulting relationships give
Kd as a function of pH only; the inherent nonlinear character of metal adsorption as a
function of total metal concentration is not represented.
In EPACMTP Monte Carlo analyses for nationwide assessments, a different pH
value is generated for each Monte Carlo iteration. Upon the selection of a pH, the
corresponding Kd is automatically calculated from the appropriate empirical relationship.
No empirical relation was available for Sb'"; so the Sbv relationship can be used
for both the +3 and +5 oxidation states. Also, the As'" species is adsorbed somewhat
less strongly than Asv, and Sevl is adsorbed less strongly than Selv. However, the
contrast in adsorption affinity between different oxidation states for these metals is not
nearly so marked as the contrast in Cr'" and Crvl. Therefore, the As'" and Sevl
relationships can be used to represent both oxidation states for these metals. The
resulting empirical relationships are presented in Table 3.3.
3-24
-------
Section 3.0 Waste and Constituent Parameters
Table 3.3 Empirical pH-dependent Adsorption Relations (Loux et al., 1990)
Metal Species
As'"
Ba"
Cd"
Crvl
Hg"
Ni"
Pb"
Sbv
Sevl
Tl
Kd (liters
H Q (0.0322 pH
-i o (0.190pHn
1 Q (0.397 pH
IQ (-0.11 7 pH
1Q (0.122 pH
1 Q (0.332 pH
-| Q (0.0768 pH
1 Q (-0.207 pH
1 Q (-0.296 pH
-i o (0.110pHH
kg1)
+ 1 .24)
h 0.638)
0.943)
+ 2.07)
+ 1 .42)
0.471)
+ 1 .55)
4- 2.996)
+ 2.71)
h 1.102)
3.3.3.2 MINTEQA2-Derived Sorption Isotherm Data
In the absence of site-specific data, the distribution coefficient for metals can be
automatically drawn from tabulated data comprising a set of non-linear sorption
isotherms created especially for use with the EPACMTP model. This option for
modeling the fate and transport of selected metals incorporates metal-specific
geochemical interactions that control the mobility of metals in the subsurface. This
modeling procedure was originally developed at the EPA's National Exposure Research
Laboratory, Ecosystems Research Division for the Hazardous Waste Identification Rule
(HWIR) and utilizes nationwide distributions of key geochemical parameters that impact
metal mobility in the subsurface.
In this methodology, the MINTEQA2 metal speciation code was used to
generate nonlinear adsorption isotherms for each metal. That is, a set of isotherms was
produced for each metal reflecting the range in geochemical environments expected
at waste sites across the nation.
To compute the adsorption distribution coefficient (Kd) values for a particular
metal, a value was selected for each of the five master variables and the MINTEQA2
model was executed over a range of total metal concentrations. The result is a
nonlinear adsorption isotherm that can be represented by the variation in Kd with total
metal concentration (or, with equilibrium dissolved concentration). This procedure was
repeated (separately for each metal) for numerous combinations of master variable
settings. The final result from MINTEQA2 was nonlinear Kd versus metal concentration
curves for combinations of master variable settings spanning the range of reasonable
values.
For each metal, the resulting set of isotherms was tabulated into a
supplementary input data file for use by the EPACMTP model. In the fate and transport
modeling for a particular metal, EPACMTP is executed and the probability distributions
for these five variables form the basis for the Monte-Carlo selection of the appropriate
3-25
-------
Section 3.0 Waste and Constituent Parameters
adsorption isotherm. A detailed discussion of the MINTEQA2 simulation procedure for
generating the metals sorption isotherms is provided in Appendix B.1.
MINTEQA2-derived sorption isotherms have been developed for the following
metals: antimony (V), arsenic (III), barium, beryllium, cadmium, chromium (III),
chromium (VI), copper (II), mercury (II), nickel, lead, selenium (VI), thallium (I),
vanadium, and zinc.
As implemented in EPACMTP, it is assumed that the non-linearity of the
isotherms is most important in the unsaturated zone where metals concentrations are
relatively high. Although MINTEQA2 isotherms were also generated for the saturated
zone, upon reaching the water table and mixing of the leachate with ambient ground
water, the metals concentration is considered to be low enough that a linear isotherm
(single Kd value not dependent on metal concentration) can always be used. The
appropriate saturated zone retardation factor is determined based on the maximum
ground-water concentration underneath the source.
Geochemical factors that are known to have direct impact on adsorption in
ground-water systems are: (1) ground-water composition, (2) subsurface pH, (3)
hydrous ferric oxide adsorbent content of the soil/aquifer in the subsurface, (4)
concentration of organic acids in the leachate, and (5) natural soil organic matter
content of the soil/aquifer in the subsurface (paniculate and dissolved). For a given
metal at a given total concentration, the propensity for adsorption changes greatly as
these parameters vary. For the MINTEQA2 modeling, two ground-water types were
used (carbonate and non-carbonate) and for each ground-water type, the natural
variability of the remaining three parameters (since only low concentrations of leachate
organic acids are expected in the leachate emanating from industrial waste
management units, only the low range was modeled for leachate organic acid content)
was divided into three ranges: high, medium, and low. The approximate mid-point of
each range was identified, and in the MINTEQA2 modeling, these mid-point values
were used to simulate each range of values for pH, hydrous ferric oxide content, and
natural organic matter. For the non-carbonate ground-water type, one isotherm (as a
function of metal concentration) was developed for each combination of the three
possible values for the four master variables. This process was then repeated for the
carbonate ground-water type. For each ground-water type, separate isotherms were
developed for the unsaturated and saturated zone. For each metal, a set of 648
isotherms was developed.
The following EPACMTP input parameters are required to model metals
transport using the MINTEQA2 non-linear isotherms: metal identification number, soil
and aquifer pH, hydrous ferric oxide adsorbent content, leachate organic matter
concentration, percent organic matter of the soil, fraction organic carbon of the aquifer,
and ground-water composition. Each of these inputs, including the data sources and
the default EPACMTP input distributions (which correspond to the values used in the
MINTEQA2 modeling) for each of the five master variables, are described in the
following sections.
3-26
-------
Section 3.0 Waste and Constituent Parameters
3.3.3.2.1 Metal Identification Number (ID)
Definition
The metal identification number is simply an arbitrary number assigned to each
metal in order to provide a simple means of specifying which metal is being modeled.
Parameter Value or Distribution of Values
The metal contaminants whose partition coefficients have been estimated using
MINTEQA2 include arsenic (As), antimony (Sb), barium (Ba), beryllium (Be), cadmium
(Cd), cobalt (Co), copper (Cu), chromium (Cr), fluoride (F), mercury (Hg), manganese
(Mn), molybdenum (Mo), lead (Pb), nickel (Ni), selenium (Se), silver (Ag), thallium (Tl),
vanadium (V), and zinc (Zn).
Several of these metals occur naturally in more than one oxidation state. The
modeling described here is restricted to the oxidation states that are most likely to occur
in waste systems or most likely to be mobile in ground-water waste systems. For
arsenic, chromium, and selenium, partition coefficients were estimated for two oxidation
states. These were: As(lll) and As(V), Cr(lll) and Cr(VI), and Se(IV) and Se(VI). For
antimony, molybdenum, thallium, and vanadium, only one oxidation state was modeled
although multiple oxidation states occur. For all four of these metals, the choice of
which state to model was dictated by practical aspects such as availability of sorption
reactions and by subjective assessment of the appropriate oxidation state. The
oxidation states modeled were Sb(V) (there were no sorption reactions available for
Sb(lll)), Mo(VI) (molybdate seems the most relevant form from literature reports),
thallium (I) (this form is more frequently cited in the literature as having environmental
implications), and V(V) (vanadate; sorption reactions were not available for other
forms).
The metal identification number for each metal with a set of MINTEQA2-derived
non-linear isotherms is presented in Table 3.4. The appropriate identification number
should be specified in the EPACMTP input file as a constant value.
3-27
-------
Section 3.0
Waste and Constituent Parameters
Table 3.4 Metals that have MINTEQA2-derived Non-linear Isotherms
Metal Species
Ba
Cd
Cr(lll)
Hg
Ni
Pb
Ag
Zn
Cu
V
Be
Mo
As (III)
Cr (VI)
Se (VI)
Tl
Sb(V)
Co
Mn
F
As(V)
Se (IV)
Metal ID
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
Data Sources
These metal identification numbers were arbitrarily created for convenience
during modeling; the list of available metals was determined by the availability of toxicity
and sorption data and their likely occurrence in industrial waste management scenarios
under consideration for Agency rule-making.
Use In EPACMTP
The metal identification number is used by the EPACMTP model to identify
which supplemental input file contains the appropriate non-linear isotherm data.
3-28
-------
Section 3.0
Waste and Constituent Parameters
3.3.3.2.2 Soil and Aquifer oH (oH)
Definition
A measure of the acidity or alkalinity of the moisture present in the vadose zone
or the ground water. pH is measured on a scale of 0 to 14, with 7 representing a
neutral state. Values less than 7 are acidic, and values greater than 7 are basic. pH
is calculated as the negative logarithm of the concentration of hydrogen ions in a
solution.
For modeling purposes, pH is assumed to be the same in the unsaturated zone
and in the saturated zone.
Parameter Value or Distribution of Values
Lacking a site-specific value or distribution of values, a default distribution of pH
values may be used. The data are represented by an empirical distribution with low and
high values of 3.2 and 9.7, respectively and a median value of 6.8. The distribution is
shown in Figure 3.5.
Table 3.5 Probability distribution of soil and aquifer pH
Cumulative Probability (%)
0.0
1.0
5.0
10.0
25.0
50.0
75.0
90.0
95.0
100.0
pH Value
3.21 E+OO
5.40E+00
6.31 E+OO
7.11 E+OO
7.59E+00
7.69E+00
7.80E+00
7.90E+00
8.09E+00
9.69E+00
Data Sources
The distribution of pH values shown in Table 3.5 was obtained through analysis
of nearly 25,000 field measured pH values of uncontaminated ground water obtained
from EPA's STORET database (U.S. EPA, 1996). Note that the upper and lower
bounds of this distribution were established by reference to reported values in the open
literature.
Use In EPACMTP
The ground-water pH is one of the most important subsurface parameters
controlling the mobility of metals. Most metals are more mobile under acidic (low pH)
conditions, as compared to neutral or alkaline (pH of 7 or higher) conditions. The pH
may also affect the hydrolysis rate of organic constituents; some constituents degrade
3-29
-------
Section 3.0 Waste and Constituent Parameters
more rapidly or more slowly as pH varies. The pH of most aquifer systems is slightly
acidic, the primary exception being aquifers in solution limestone settings. These may
also be referred to as 'karst', 'carbonate' or 'dolomite' aquifers. The ground water in
these systems is usually alkaline.
The EPACMTP model assumes that the ground-water/aquifer system is well
buffered with respect to pH. That is, in the modeling analysis, there is no effect on the
ambient pH from the leachate emanating from the base of the WMU.
3.3.3.2.3 Iron Hydroxide Content fFeOx)
Definition
The nature and amount of solid matter in the subsurface to which metals are
attracted (the adsorbent) are important in determining the extent to which a
constituent's transport through the ground-water pathway is retarded due to adsorption.
Iron hydroxides (FeOx) represent one of the dominant adsorbents for metal sorption in
environmental systems, and were one of the geochemical master variables used in the
calculation of the non-linear sorption isotherms using the MINTEQA2 model. Although
other sorbents such as clay minerals, carbonate minerals, hydrous aluminum and
manganese oxides, and silica may sorb metals in the subsurface, accounting for ferric
hydroxide and paniculate organic matter (see Section 3.3.3.2.5 for a discussion on
paniculate organic matter) is sufficient to produce a realistic, yet protective, modeling
analysis for most natural ground-water systems.
Parameter Value or Distribution of Values
In the MINTEQA2 modeling that was used to calculate the isotherms for a
number of metals, the type of ferric oxide that was assumed to be present was in the
form of the mineral goethite (FeOOH), a common form of ferric oxide in soils. A
database of sorption reactions for goethite reported by Mathur (1995) was used with the
diffuse-layer sorption model in MINTEQA2 to represent the interactions of protons and
metals with the goethite surface. Further details of the MINTEQA2 modeling procedure
are given in Appendix B.1.
Lacking a site-specific value or distribution of values for this input parameter, a
default distribution may be used. The limited data on iron hydroxide content that are
available (Loux et al., 1990) were used to define a uniform distribution, with a minimum
of 0.0126 and a maximum of 1.115 percent iron hydroxide by weight. A summary of
this default distribution is presented in Table 3.6.
3-30
-------
Section 3.0 Waste and Constituent Parameters
Table 3.6 Probability distribution of fraction iron hydroxide
Cumulative Probability (%)
0.0
1.0
5.0
10.0
25.0
50.0
75.0
90.0
95.0
100.0
Iron Hydroxide Content
1.82E-02
2.89E-02
4.37E-02
6.85E-02
9.36E-02
9.84E-02
1.04E-01
1.09E-01
1.14E-01
1.19E-01
(wt %)
Data Sources
The default distribution is based on analyses by Loux et al., (1990) on aquifer
samples collected by the U.S. EPA Office of Solid Waste (OSW) in Florida, New Jersey,
Oregon, Texas, Utah, and Wisconsin.
Use In EPACMTP
The iron hydroxide content of the subsurface is one of the most important
subsurface parameters controlling the mobility of metals. In EPACMTP, accounting for
ferric hydroxide determines the extent to which a constituent's transport through the
ground-water pathway is retarded due to adsorption.
3.3.3.2.4 Leachate Organic Matter (LOM)
Definition
In addition to the metal contaminants, the leachate exiting a WMU may contain
elevated concentrations of leachate organic matter. This organic matter may consist
of various compounds including organic acids that represent primary disposed waste
or that result from the breakdown of more complex organic substances. Many organic
acids found in leachate have significant metal-complexing capacity that may influence
metal mobility. This input represents the concentration of these anthropogenic organic
acids in the leachate emanating from the base of the WMU.
Parameter Value or Distribution of Values
Lacking a site-specific value or distribution of values for the concentration of
organic acids in the leachate (which can then be used to help generate site-specific kd
values), the influence of leachate organic matter on metal sorption may be represented
by using a default distribution of values for this input parameter. The default distribution
is uniform, with a minimum of 0.001173 mg/L and a maximum of 0.00878 mg/L. A
summary of this default distribution is presented in Table 3.7.
3-31
-------
Section 3.0 Waste and Constituent Parameters
Table 3.7 Probability distribution of leachate organic matter
Cumulative Probability (%)
0.0
1.0
5.0
10.0
25.0
50.0
75.0
90.0
95.0
100.0
Concentration of Leachate Organic
1.05E+02
1.40E+02
1.94E+02
2.84E+02
3.76E+02
3.94E+02
4.12E+02
4.30E+02
4.47E+02
4.67E+02
Matter (mg/L)
Data Sources
In an effort to incorporate in the ground-water modeling the solubilizing effect
of organic acids, a default distribution of leachate organic matter concentrations was
developed based on data presented by Gintautas, Huyck, Daniel, and Macalady (1993).
This study examined leachates from six landfills from across the U. S. and found that
over 30 different acids were present. The range of leachate organic matter
concentration levels given in the default distribution is based on the measured total
organic carbon among the six landfill leachates in this study.
Use In EPACMTP
The concentration of anthropogenic organic acids in leachate is one of the most
important subsurface parameters controlling the mobility of metals. In EPACMTP, this
parameter is used to quantify metal-complexing capacity that may influence metal
mobility.
3.3.3.2.5 Percent Organic Matter (%OM)
Definition
The nature and amount of solid matter in the subsurface to which metals are
attracted (the adsorbent) are important in determining the extent to which a
constituent's transport through the ground-water pathway is retarded due to adsorption.
Paniculate organic matter present in the unsaturated zone (input to EPACMTP as
percent organic matter) represents one of the dominant adsorbents for metal sorption
in environmental systems and was one of the geochemical master variables used in the
calculation of the non-linear sorption isotherms using the MINTEQA2 model. Although
other sorbents such as clay minerals, carbonate minerals, hydrous aluminum and
manganese oxides, and silica may sorb metals in the subsurface, accounting for ferric
hydroxides (See Section 3.3.3.2.3 for a discussion of FeOx) and paniculate organic
matter (in the soil and aquifer) is sufficient to produce a realistic, yet protective,
modeling analysis for most natural ground-water systems. In EPACMTP modeling, the
3-32
-------
Section 3.0
Waste and Constituent Parameters
amount of paniculate organic matter in the soil (as opposed to the aquifer, represented
by the term foc) is represented by the percent organic matter (%OM).
Parameter Value or Distribution of Values
Lacking a site-specific value or distribution of values for this input parameter
(which can then be used to help generate site-specific kd values), a default distribution
may be used. In the EPACMTP model, there are three default soil types (sandy loam,
silty loam, and silty clay loam); each soil type has a unique distribution of values for
each of the soil parameters, including the percent organic matter. When modeling a
metal using the MINTEQA2-derived isotherms, the default distribution for percent
organic matter in the unsaturated zone is based on the default distribution for percent
organic matter for the silty loam soil type. The silty loam soil type is intermediate in
weight percent organic matter in comparison with the other two and is the most
frequently occurring soil type. The default distribution type is Johnson SB; the minimum
value is 0.0 and the maximum value is 8.51. A summary of this default distribution is
presented in Table 3.8.
Table 3.8 Probability distribution of percent organic matter in the unsaturated
zone
Cumulative Probability (%)
Percent Organic Matter in the
Unsaturated Zone (unitless)
o.o
1.0
5.0
10.0
25.0
50.0
75.0
90.0
95.0
100.0
4.08E-03
3.76E-02
6.07E-02
1.04E-01
1.78E-01
2.04E-01
2.38E-01
2.87E-01
3.82E-01
1.80E+00
Data Sources
The default distribution described above for the percent organic matter in the
unsaturated zone is based on data presented in Carsel and Parrish, 1988.
Use In EPACMTP
The percent organic matter in the unsaturated zone is used in EPACMTP
because the nature and amount of solid matter in the subsurface to which metals are
attracted (the adsorbent) are important in determining the extent to which a
constituent's transport through the ground-water pathway is retarded due to adsorption.
As the adsorption of a contaminant in the unsaturated zone increases, more of the
contaminant is removed from the system, and is unavailable for transport.
3-33
-------
Section 3.0 Waste and Constituent Parameters
3.3.3.2.6 Fraction Organic Carbon (LJ
Definition
The nature and amount of solid matter in the subsurface to which metals are
attracted (the adsorbent) are important in determining the extent to which a
constituent's transport through the ground-water pathway is retarded due to adsorption.
Paniculate organic matter present in the saturated zone represents one of the dominant
adsorbents for metal sorption in environmental systems and was one of the
geochemical master variables used in the calculation of the non-linear sorption
isotherms using the MINTEQA2 model. Although other sorbents such as clay minerals,
carbonate minerals, hydrous aluminum and manganese oxides, and silica may sorb
metals in the subsurface, accounting for ferric hydroxide (see Section 3.3.3.2.3 for a
discussion of FeOx) and paniculate organic matter (in the soil and aquifer) is sufficient
to produce a realistic, yet protective, modeling analysis for most natural ground-water
systems. In EPACMTP modeling, the amount of paniculate organic matter in the
aquifer is represented by the fraction organic carbon, or foc (as opposed to the soil,
represented by the term %OM).
Parameter Value or Distribution of Values
Lacking a site-specific value or distribution of values for this input parameter
(which can then be used to help generate site-specific kd values), a default distribution
may be used. In the EPACMTP model, there are three default soil types (sandy loam,
silty loam, and silty clay loam); each soil type has unique distribution of values for each
of the soil parameters, including the percent organic matter. When modeling a metal
using the MINTEQA2-derived isotherms, the default distribution for fraction organic
carbon in the saturated zone is based on the default distribution for percent organic
matter for the sandy loam soil type, however, this value is converted from percent
organic matter to fraction organic carbon using Equation 5.1. The sandy loam soil type
is higher in weight percent organic matter in comparison with the other soil types. The
default distribution type is Johnson SB; the minimum value is 0.0 and the maximum
value is 11.0. A summary of this default distribution is presented in Table 3.9.
3-34
-------
Section 3.0
Waste and Constituent Parameters
Table 3.9 Probability distribution of fraction organic carbon in the saturated
zone
Cumulative Probability (%)
Fraction Organic Carbon in the
Saturated Zone (unitless)
o.o
1.0
5.0
10.0
25.0
50.0
75.0
90.0
95.0
100.0
1.61E-05
1.31E-04
2.30E-04
4.31 E-04
8.00E-04
9.27E-04
1.10E-03
1.35E-03
1.88E-03
1.24E-02
Data Sources
The default distribution described above for the fraction organic carbon in the
saturated zone is based on data presented in Carsel, Parrish, Jones, Hansen, and
Lamb, 1988.
Use In EPACMTP
The fraction organic carbon in the saturated zone is one of the most important
subsurface parameters controlling the mobility of metals, since it is used in determining
the extent to which a constituent's transport through the ground-water pathway is
retarded due to adsorption. .
3.3.3.2.7 Ground-water Type fIGWT)
Definition
Ground-water chemistry exerts an important influence on metal partition
coefficients. The major ions present in ground water may compete with trace metals
for sorption sites. Also, inorganic ligands may complex with some metals, thereby
reducing their tendency to sorb. For the purposes of this modeling, partition coefficients
were estimated separately for two ground-water compositional types, one with
composition representative of a carbonate-terrain system and one representative of a
non-carbonate system. The two ground-water compositional types are correlated with
the hydrogeologic environment index in EPACMTP (see Section 5.3.4.2). In
EPACMTP, this parameter may take on one of thirteen values, but issues of practicality
limit the number of ground-water types for which separate partition coefficients can be
estimated to just two. The broadest division of ground waters that may be made for the
thirteen hydrogeologic environments in EPACMTP is carbonate and non-carbonate
types of ground waters. Thus, these are the two broad types for which coefficients
were estimated.
3-35
-------
Section 3.0 Waste and Constituent Parameters
Parameter Value or Distribution of Values
By default, the ground-water type is directly correlated to the hydrogeologic
environment setting in EPACMTP. In the default databases of WMU sites that have
been compiled into auxiliary input files (called the site data files), each WMU site has
been classified by the predominant hydrogeologic environment at the site. In
EPACMTP, there are thirteen possible hydrogeologic environments. For the "solution
limestone" hydrogeologic environment setting (IGWR = 12), the ground-water type is
set to carbonate. The ground-water type for the other twelve possible hydrogeologic
settings in EPACMTP are represented by the non-carbonate ground-water type.
Data Sources
The ground-water type is simply an arbitrary number assigned to provide a
simple means of specifying which set of isotherms should be used (there is one set for
carbonate ground water and another set for non-carbonate ground water). For both
ground-water types, a representative, charge-balanced ground-water chemistry
specified in terms of major ion concentrations and natural pH was selected from the
literature. The carbonate system was represented by a well sample reported for a
limestone aquifer (Freeze and Cherry, 1979). This ground water had a natural pH of
7.5 and was saturated with respect to calcite. The non-carbonate system was
represented by a sample reported from an unconsolidated sand and gravel aquifer with
a natural pH of 7.4 (White, Hem, and Waring, 1963). An unconsolidated sand and
gravel aquifer was selected to represent the non-carbonate compositional type because
it is the most frequently occurring of the twelve (non-carbonate) hydrogeologic
environments in EPACMTP. More details about the MINTEQA2 modeling methodology
and the compositions of both the carbonate and non-carbonate representative ground-
water samples are presented in Appendix B.1.
Use In EPACMTP
The ground-water type is one of the most important subsurface parameters
controlling the mobility of metals, since the major ions present in ground water may
compete with trace metals for sorption sites. This may result in less availability of
sorption sites for contaminants as they enter the ground water.
3-36
-------
Section 4.0 Infiltration and Recharge Parameters
4.0 INFILTRATION AND RECHARGE PARAMETERS
This section discusses the individual parameters related to infiltration and
recharge that are required to perform a modeling analysis using EPACMTP.
Although most applications of EPACMTP are conducted on a national or regional
basis for regulatory development purposes, EPACMTP can also be used in a
location or a waste-specific mode. In either case, each of the input parameters
related to the climatic characteristics of the site(s) being modeled can be specified
as a constant value or as a statistical or empirical distribution of values. As a
practical matter, however, many of these inputs are commonly specified as
distributions of values as part of the regional site-based modeling methodology.
In EPACMTP, the infiltration and recharge-related input parameters include
the climate center location, infiltration and recharge rates, and the soil and aquifer
temperature. The climate center location is specified as an index that represents the
climate center nearest to the waste site being modeled. The climate center index
allows the model to access a default set of infiltration and recharge rates that are
specific to a WMU type, soil type, and geographic location.
The infiltration rate is defined as the rate at which leachate flows from the
bottom of the WMU (including any liner) into the unsaturated zone beneath the
WMU. Recharge is the regional rate of aquifer recharge outside of the WMU.
Infiltration rate is among the most sensitive site-specific parameters in an EPACMTP
evaluation, whereas the model is usually much less sensitive to recharge. For
landfills (LFs), waste piles (WPs), and land application units (LAUs), the infiltration
rate is determined primarily by the local climatic conditions, especially annual
precipitation and WMU liner characteristics. For Sis, the infiltration rate is a function
of the surface impoundment ponding depth, liner characteristics, and the presence
of a 'sludge' layer at the bottom of the impoundment. The regional recharge rate is
a function of the annual precipitation rate, and varies with geographical location and
soil type.
These infiltration and recharge-related parameters are individually described
in the following sections.
4.1 INFILTRATION AND RECHARGE PARAMETERS
The input parameters that are used in EPACMTP to describe the climatic
characteristics of the WMU site to be modeled are listed in Table 4.1 on the
following page.
4-1
-------
Section 4.0
Infiltration and Recharge Parameters
Table 4.1 Climate Parameters
Parameter
Climate Center Index
Landfill Infiltration Rate
Waste Pile Infiltration
Rate
Land Application Unit
Infiltration Rate
Surface Impoundment
Infiltration Rate
Recharge Rate
Symbol
ICLR
1
1
1
1
IR
Units
-
m/yr
m/yr
m/yr
m/yr
m/yr
Section
4.2
4.3.1
4.3.2
4.3.3
4.3.4
4.4
Equation in
EPACMTP TBD
--
3.4
3.4
3.4
2.24
4.10
4.2 CLIMATE CENTER INDEX (ICLR)
Definition
The climate center index is simply a sequential number assigned to each of
102 climate centers in the default database included with EPACMTP in order to
provide a simple means of specifying which infiltration and recharge rates should be
used to model the given WMU site.
Parameter Value or Distribution of Values
The climate centers for which default infiltration rates (for LFs, WPs, and
LAUs) and recharge rates (for LFs, WPs, Sis, and LAUs) are available are listed in
Table 4.2. The geographic locations are depicted in Figure 4.1. For each of the
locations listed in Table 4.2, the U.S. EPA used the Hydrologic Evaluation of Landfill
Performance (HELP) model (Schroeder, Dozier, Zappi, McEnroe, Sjostrom, and
Peton, 1994) to compute recharge rates for all units, as well as infiltration rates for
LAUs and for LFs and WPs with no-liner and single-liner designs. Appendix A
provides additional information about how EPA used the HELP model, in conjunction
with data from climate stations across the United States, to develop these
nationwide recharge and infiltration rate distributions, as well as a detailed
discussion of how infiltration rates were developed for different liner designs for each
type of WMU.
In developing this default distribution of infiltratoin rates, we started with an
existing database of no-liner infiltration rates for LFs, WPs and LAUs. Also existing
were recharge rates for 97 climate stations in the lower 48 contiguous United States
(ABB, 1995), that are representative of 25 specific climatic regions (developed with
HELP version 3.03). We then added five climate stations (located in Alaska, Hawaii,
and Puerto Rico) to ensure coverage throughout all of the United States. Rather
than calculating infiltration rates for each of the 102 individual climate stations,
4-2
-------
Section 4.0
Infiltration and Recharge Parameters
infiltration rates were calculated for the 25 climate regions, and then assigned the
same value to each climate station in one group. In order to reduce the number of
required HELP simulations, one station from each climate region was simulated, and
the resulting value assigned to each climate station within the region. To be
protective, EPA chose the climate center with the highest average precipitation in
each climate region (which would tend to maximize constituent transport) to
represent the region. Individual infiltration rates were calculated for each of the five
climate centers not assigned to a climate region (centers from Alaska, Hawaii, and
Puerto Rico).
Table 4.2 Climate Centers Used in the HELP Modeling to Develop Infiltration
and Recharge Rates
Index
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
85
86
87
City
Fresno
Boise
Denver
Grand Junction
Pocatello
Glasgow
Bismarck
Pullman
Yakima
Cheyenne
Lander
Los Angeles
Sacramento
San Diego
Santa Maria
Ely
Rapid City
Cedar City
Albuquerque
Las Vegas
Phoenix
Tucson
El Paso
Medford
Great Falls
Salt Lake City
Grand Island
Flagstaff
Knoxville
Central Park
Lexington
State
CA
ID
CO
CO
ID
MT
ND
WA
WA
WY
WY
CA
CA
CA
CA
NV
SD
UT
NM
NV
AZ
AZ
TX
OR
MT
UT
NE
AZ
TN
NY
KY
Index
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
91
92
93
City
Dodge City
Midland
St. Cloud
E. Lansing
North Omaha
Tulsa
Brownsville
Dallas
Oklahoma City
Concord
Pittsburgh
Portland
Caribou
Chicago
Burlington
Bangor
Rutland
Seattle
Montpelier
Sault St. Marie
Put-in-Bay
Madison
Columbus
Cleveland
Des Moines
E. St. Louis
Columbia
Topeka
Tallahassee
New Orleans
Charleston
State
KS
TX
MN
Ml
NE
OK
TX
TX
OK
NH
PA
OR
ME
IL
VT
ME
VT
WA
VT
Ml
OH
Wl
OH
OH
IA
IL
MO
KS
FL
LA
SC
Index
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
97
98
99
City
Tampa
San Antonio
Hartford
Syracuse
Worchester
Augusta
Providence
Portland
Nashua
Ithaca
Boston
Schenectady
Lynchburg
New York City
Philadelphia
Seabrook
Indianapolis
Cincinnati
Bridgeport
Orlando
Greensboro
Jacksonville
Watkinsville
Norfolk
Shreveport
Astoria
New Haven
Plainfield
Miami
Annette
Bethel
State
FL
TX
CT
NY
MA
ME
Rl
ME
NH
NY
MA
NY
VA
NY
PA
NJ
IN
OH
CT
FL
NC
FL
GA
VA
LA
OR
CT
MA
FL
AK
AK
4-3
-------
Section 4.0
Infiltration and Recharge Parameters
Index
88
89
90
City | State | Index
Edison
Nashville
Little Rock
NJ
TN
AK
94
95
96
City
W. Palm Beach
Atlanta
Lake Charles
State
FL
GA
LA
Index
100
101
102
City
Fairbanks
Honolulu
San Juan
State
AK
HI
PR
Data Sources
The list of available climate centers was determined by the availability of
meteorological data required for the HELP model and geographic coverage of the
United States.
Use In EPACMTP
EPACMTP includes a database of infiltration rates and regional recharge
rates for 102 climate centers located throughout the United States. The climate
center index is a sequential number assigned to each climate center in the default
database included with EPACMTP in order to provide a simple means of specifying
which infiltration and recharge rates should be used to model the given WMU site
(See Appendix A for a discussion on the determination of infiltration and recharge
rates).
This parameter is used as a part of the regional site-based modeling
methodology, in which a number of parameters related to the characteristics of the
waste site are drawn from a correlated set of data. These default databases of site-
related parameters (one for each WMU type) are commonly referred to as the site
data files. To perform a Monte Carlo analysis using the regional site-based
modeling methodology, the climate center index is provided in the site data files as
the default setting, which will ensure that the appropriate climatic data is used for
each WMU site in the database. However, if a location-adjusted or quasi-site-
specific analysis is being performed, this input can either be omitted from the input
file (if site-specific infiltration and recharge rates are available) or assigned a climate
center index that is most appropriate to make use of the default location- and soil-
specific infiltration and recharge rates which are included in the site data file.
Usually this is the nearest climate center. However, this is not always the case.
Especially in coastal and mountain regions, the nearest climate center does not
always represent conditions that most closely approximate conditions at a specific
site.
4-4
-------
Giribou
Nashua
Lexington
Boston
Wrcester
Rovidsnce
•hMond
Na/vhteei
Bidjeport
GfertnalRrk
Na/vYok
Hison
Vfet Rim Bach
Maii
Aasta
RertoRkx)
SP
o
<-+•
§'
<-+•
§'
0)
<
CD
3
CD
Figure 4.1 Locations of EPACMTP Climate Stations
-------
Section 4.0 Infiltration and Recharge Parameters
4.3 INFILTRATION RATES
The EPACMTP model requires input of the net rate of vertical downward
percolation of water and leachate through the unsaturated zone to the water table.
Infiltration refers to the water that percolates through a WMU to the underlying soil,
whereas recharge is water percolating through the soil to the aquifer outside the
footprint of the WMU. The model allows the infiltration rate to be different from the
ambient regional recharge rate. These rates can differ for a variety of reasons,
including the engineering design of the WMU, topography, land use, and vegetation.
Note that both infiltration and recharge are specified as areal rates, with the units of
cubic meters of fluid (water or leachate) per square meter per year (m3/m2/yr). Thus,
the units for infiltration and recharge simplify to meters per year (m/yr).
Infiltration and recharge rates for use in EPACMTP modeling applications
have been estimated for selected soil types at cities around the country through the
use of the HELP water-balance model (Version 3.03) (Schroeder et al., 1994), as
summarized below. Further details about the HELP modeling inputs, assumptions
for each type of WMU, and the resulting databases of infiltration and recharge rates
are given in Appendix A.
Using the Soil Conservation Service's (SCS) county-by-county soil mapping
database, the soil classifications in the U.S. were grouped according to the U.S.
Department of Agriculture's definitions of coarse, medium, and fine textures. These
three categories are represented in EPACMTP by soils equivalent in properties to
sandy loam (SNL), silt loam (SLT), and silty clay loam (SCL). An analysis of the
SCS database indicates that coarse grained soils, medium grained soils, and fine
grained soils represent 15.4 percent, 56.6 percent, and 28.0 percent, respectively, of
the soils that have been mapped by the SCS.
The National Oceanic and Atmospheric Administration (NOAA) has data on
precipitation and evaporation rates in the United States. This nationwide database
was used to categorize the meteorological conditions in the U. S. into 18 climatic
regions; 102 cities covering all 18 of the climatic regions were selected as climatic
centers for the HELP model (Figure 4.1). For each selected city, climatic data for
five years were accessed and used to develop leaching rates for different types of
waste management scenarios as a function of site location and soil type. The
resulting HELP-model-generated infiltration and recharge rates are incorporated into
EPACMTP.
EPACMTP provides default values for infiltration rate as a function of WMU
type, liner design, and site location. These values were calculated for unlined and
single-lined landfills, waste piles, and land application units for each of the 102
climatic centers with the HELP model, using the procedure described in Appendix A.
For composite-lined landfills and waste piles, these values are chosen from an
empirical distribution of values based on the results of a literature review (TetraTech,
2001). In the case of surface impoundments, EPACMTP directly calculates the
infiltration rate as a function of WMU characteristics, including liner type.
4-6
-------
Section 4.0 Infiltration and Recharge Parameters
Because the infiltration rate from a WMU is difficult to measure directly, a
model such as HELP is used to estimate the WMU infiltration rates for use in
EPACMTP.
The data sources for infiltration rates for each type of WMU and the resulting
infiltration rates are summarized in the following sections.
4.3.1 Landfill Infiltration Rate (I)
Definition
The landfill infiltration rate (m/yr) is defined as the rate at which
water/leachate percolates through the landfill to the underlying soil. The landfill
infiltration rate may be different from the ambient regional recharge rate due to the
engineering design of the landfill (e.g., landfill cover soil that has a lower conductivity
than the regional soils), topography, land use, and vegetation.
For the no-liner case, a two-foot (0.61 m) soil cover was assumed to
represent Subtitle D landfills that do not contain a liner and leak detection system,
and therefore would not be required by the regulations to have a cap of less
permeability than the liner system. Two feet was selected as the thickness of the
cover as the minimum requirement of Subtitle D. Three default soil types were
selected: sandy loam, silt loam, and silty clay loam, corresponding to the coarse,
medium, and fine grained soil types as described in Section 4.3. These three soil
types are assumed to support vegetation in the United States and are the three soil
types used in the leachate flux analysis performed in support of the TC Rule
modeling analysis (U.S. EPA, 1990).
For the single-clay liner case, a 3-ft. (0.914m) clay cover with a hydraulic
conductivity of 1x10~7 cm/sec, a 1-ft. (0.305m) layer of loam overlying the cover (to
support vegetation and drainage), a 10-ft. (3.05m) waste layer, a 1-ft. (0.305m)
percolation layer, and a 3-ft. (0.914m) clay liner with a hydraulic conductivity of 1 x10"
7 cm/sec were specified in the HELP model input file. Additionally, the modeling
assumed that there is no leachate collection system and that the infiltration rate is
constant (that is, no increase in hydraulic conductivity of liner) over the modeling
period.
A composite liner was defined as a 60 mil HOPE layer with either an underlying
geosynthetic clay liner with maximum hydraulic conductivity of 5x10~9 cm/sec, or a 3-
ft. (0.914m) compacted clay liner with maximum hydraulic conductivity of 1x10~7
cm/sec. As in the single-clay liner case, this scenario assumes a constant infiltration
rate (i.e., no increase in hydraulic conductivity of liner) over the modeling period.
Parameter Value or Distribution of Values
When the EPACMTP model is run for an unlined or single-lined landfill using
the regional, site-based methodology, the model selects a site at random from those
in the site data file for each Monte Carlo realization. Since the landfill cover and soil
4-7
-------
Section 4.0
Infiltration and Recharge Parameters
type for the landfills in the 1986 Subtitle D Survey were unknown, a random
combination of landfill cover soil type and regional soil type are then generated from
a national joint probability distribution (assuming that the relative frequency of
different soil and cover types is nationally uniform) (U.S.EPA, 1990). The climate
center index associated with the chosen site and the randomly generated soil types
are then used by the model to determine the recharge and infiltration values of the
site from the HELP database also included in the site data file. In the case of
unlined landfills, if the cover type and soil type underneath the unit are the same, the
infiltration rate will be identical to the regional recharge rate for that soil type.
The cumulative frequency distributions of LF infiltration for the three default
liner scenarios are presented in Table 4.3, and are based on the estimates
described in the following sections; the LF infiltration rates for each climate center
are presented in Appendix A.
Table 4.3 Cumulative Frequency Distribution of Landfill Infiltration
%
0
10
25
50
75
80
85
90
95
100
No Liner
Infiltration Rate
(m/yr)
1.00E-05
1.35E-02
6.58E-02
1.09E-01
2.74E-01
3.12E-01
3.53E-01
4.11E-01
4.56E-01
1.08E+00
Clay Liner
Infiltration Rate
(m/yr)
1.00E-05
9.44E-03
2.53E-02
4.32E-02
4.45E-02
4.77E-02
4.77E-02
4.86E-02
4.86E-02
5.26E-02
Composite Liner
Infiltration Rate
(m/yr)
O.OOE+OO
O.OOE+00
O.OOE+OO
O.OOE+00
7.30E-05
7.30E-05
1.12E-04
1.69E-04
2.83E-04
4.01 E-04
Data Sources
The HELP model (Schroeder, et al., 1994) was used to estimate the rate at
which leachate emanates from the base of the landfill for the no-liner and single-clay
liner scenarios, using the procedure described in Appendix A.
For the composite liner case, the EPACMTP model randomly selects an
infiltration rate from a default database of values which were compiled from a
literature review of leak detection system flow rates (TetraTech, 2001).
When the EPACMTP model is run for a composite-lined landfill using the
regional, site-based methodology, the model selects an infiltration rate at random
from those in the default distribution for each Monte Carlo realization.
In a location-specific modeling analysis, the site-specific infiltration rate can
4-8
-------
Section 4.0 Infiltration and Recharge Parameters
be directly specified in the input file - either as a constant value or as a statistical or
empirical distribution of values.
Use In EPACMTP
The landfill infiltration rate is used by the model to determine the leaching
duration and leachate concentration when the landfill depleting source option is
used. Infiltration rate is also used by the model to determine the leachate flux to the
subsurface and as an input to the subsurface flow and transport modules.
4.3.2 Waste Pile Infiltration Rate (I)
Definition
The waste pile infiltration rate is defined as the rate at which water/leachate
percolates through the waste pile to the underlying soil. The waste pile infiltration
rate may be different from the ambient regional recharge rate due to the engineering
design of the waste pile (e.g., uncovered waste has a different conductivity than the
regional soils), topography, land use, and vegetation.
For the purposes of estimating leaching rates using the HELP model, waste
piles were considered to be similar to non-covered landfills. Thus, the infiltration
rates for unlined and single-lined waste piles were generated using the same
general procedures as for landfills, but with the following modifications. Because of
the limited requirements for leachate collection systems in most states, after closure,
waste piles will approximate the landfill configuration selected for modeling, i.e.,
waste covered by two feet of soil. Modeling of closed waste piles was, therefore, not
necessary as their leaching characteristics are similar to closed landfills. Active
waste piles, however, differ from landfills in that the waste generally remains
uncovered. So the HELP model was used to model the leachate flux for waste piles
through active, uncovered piles without leachate collection systems.
For the unlined scenario, the waste piles were modeled as a one-layer
landfill, with the uncovered waste material comprising the layer. The waste material
was assumed to be a moderate permeability waste - coal bottom ash with a
permeability of 4.1 x10"4 cm/sec.
For the single-lined scenario, an additional parameter - waste type
permeability - is used. Since waste piles are not typically covered, the permeability
of the waste itself can be a factor in determining the rate of leachate released due to
water percolating through the WMU. For waste piles, the HELP modeling was
conducted using three categories of waste permeability: high permeability (0.041
cm/sec); moderate permeability (0.0041 cm/sec); and low permeability (0.00005
cm/sec). The waste permeability is generally correlated with the grain size of the
waste material, ranging from coarse- to fine-grained materials. Additionally, the
modeling assumed that there is no leachate collection system and that the infiltration
rate is constant (that is, no increase in hydraulic conductivity of liner) over the
modeling period.
4-9
-------
Section 4.0
Infiltration and Recharge Parameters
For the composite-lined scenario, the EPACMTP model randomly selects an
infiltration rate from a default database of values which were compiled from a
literature review of leak detection system flow rates (TetraTech, 2001). For the
purposes of this literature review, a composite liner was defined as a 60 mil HOPE
layer with either an underlying geosynthetic clay liner with maximum hydraulic
conductivity of 5x10~9 cm/sec, or a 3-ft.(0.914m) compacted clay liner with maximum
hydraulic conductivity of 1 x 10"7 cm/sec. As in the single-clay liner case, this
scenario assumes a constant infiltration rate (i.e., no increase in hydraulic
conductivity of liner) over the modeling period.
Parameter Value or Distribution of Values
The cumulative frequency distributions of WP infiltration for the three default
liner scenarios are presented in Table 4.4, based on the estimates described in the
following section; the WP infiltration rates for each climate center are presented in
Appendix A.
Table 4.4 Cumulative Frequency Distribution of Waste Pile Infiltration
%
0
10
25
50
75
80
85
90
95
100
No Liner Infiltration
Rate (m/yr)
3.00E-04
6.02E-02
1.28E-01
2.55E-01
3.91 E-01
4.49E-01
4.76E-01
5.38E-01
6.14E-01
1.82E+00
Clay Liner Infiltration
Rate (m/yr)
1.00E-05
2.64E-02
9.50E-02
1.27E-01
1.33E-01
1.33E-01
1.34E-01
1.35E-01
1.35E-01
1.36E-01
Composite Liner
Infiltration Rate (m/yr)
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
7.30E-05
7.30E-05
1.16E-04
1.67E-04
2.80E-04
4.01 E-04
Data Sources
The HELP model (Schroeder et. al., 1994) was used to estimate the rate at
which leachate emanates from the base of the waste pile for the no-liner and single-
clay liner scenarios. This modeling methodology is summarized here and is more
fully described in Appendix A.
4-10
-------
Section 4.0 Infiltration and Recharge Parameters
Use In EPACMTP
When the EPACMTP model is run for an unlined or single-lined waste pile
using the regional, site-based methodology,the model selects a site at random from
those in the site data file for each Monte Carlo realization The climate center index
associated with the chosen site and the randomly generated soil types are then used
by the model to determine the recharge and infiltration values of the site from the
HELP databases also included in the site data file.
When the EPACMTP model is run for a composite-lined waste pile using the
regional, site-based methodology, the model selects an infiltration rate at random
from those in the default distribution for each Monte Carlo realization.
In a location-specific modeling analysis, the site-specific infiltration rate can
be directly specified in the input file - either as a constant value or as a statistical or
empirical distribution of values.
Once the waste pile infiltration rate is generated, it is used by the model to
determine the leachate flux to the subsurface and as an input to the subsurface flow
and transport modules.
4.3.3 Land Application Unit Infiltration Rate (I)
Definition
The land application unit infiltration rate is defined as the rate at which water/
leachate percolates through the land application unit to the underlying soil. Although
the actual infiltration rate at a land application site may be slightly different from the
ambient regional recharge rate due to the additional water in the land applied
sludge, topography, land use, and vegetation, the default Monte Carlo analysis in
EPACMTP assumes that these rates are identical.
Based upon sensitivity analyses using a range of waste application rates,
EPA established that the addition of amounts of water through application of sludge-
type wastes does not significantly impact the soil water balance, and therefore has
little to no effect on the calculated net infiltration. Only for sites located in arid
regions of the United States with very little natural precipitation did high application
rates have an appreciable effect. For more representative waste application rates,
the effect disappeared because introducing additional moisture in the simulated
water balance resulted in a commensurate increase in runoff and removal by
evapotranspiration.
Based on these results, the land application unit infiltration rates at the 102
climate centers were taken to be the same as the ambient regional recharge rate for
that climatic center and soil type. In addition, the recharge rate for a given climate
center and soil type is taken to be the same as the corresponding landfill infiltration
rate.
4-11
-------
Section 4.0
Infiltration and Recharge Parameters
Parameter Value or Distribution of Values
When the EPACMTP model is run for a land application unit using the
regional, site-based methodology, he model selects a site at random from those in
the site data file for each Monte Carlo realization The climate center index
associated with the chosen site and the randomly generated soil types are then used
by the model to determine the recharge and infiltration values of the site from the
HELP databases also included in the site data file.
The cumulative frequency distribution of LAU infiltration for the no-liner
scenario is presented in Table 4.5, based on the estimates described in the following
sections; the LAU infiltration rates for each climate center are presented in Appendix
A.
Table 4.5 Cumulative Frequency Distribution of Land Application Unit
Infiltration
%
0
10
25
50
75
80
85
90
95
100
No Liner Infiltration
1.00E-05
1.30E-02
7.04E-02
1.10E-01
2.01 E-01
2.57E-01
2.89E-01
3.26E-01
3.65E-01
7.45E-01
Rate (m/yr)
Data Sources
In a location-specific modeling analysis, the site-specific infiltration rate can
be directly specified in the input file - either as a constant value or as a statistical or
empirical distribution of values.
The HELP model was used to estimate the rate at which leachate emanates
from the base of the land application unit for the no-liner scenario. This modeling
methodology is summarized here and is more fully described in Appendix A.
Use In EPACMTP
Once the land application unit infiltration rate is generated, it is used by the
model to determine the leachate flux to the subsurface and as an input to the
subsurface flow and transport modules.
4-12
-------
Section 4.0 Infiltration and Recharge Parameters
4.3.4 Surface Impoundment Infiltration Rate (I)
Definition
The surface impoundment infiltration rate is defined as the rate at which
water/leachate percolates through the surface impoundment to the underlying soil.
The surface impoundment infiltration rate is generally larger than the ambient
regional recharge rate due to the hydraulic head created by the wastewater in the
impoundment.
For the surface impoundment scenario, the leachate flux rate is computed as
a derived parameter, as part of the unsaturated zone flow module in EPACMTP.
The algorithm is described in the EPACMTP Technical Background Document (US
EPA, 2003a). In a typical Monte Carlo modeling analysis of a surface impoundment,
the infiltration rate is derived by the EPACMTP model. Technically, the SI infiltration
rate is not really an input parameter; rather, the model calculates infiltration rates "on
the fly" during the simulation. In the event that the SI is reported to have its base
below the water table, EPACMTP calculates the infiltration using Darcy's law based
on the hydraulic gradient across and the hydraulic conductivity of the consolidated
sediment and any liner material at the bottom of the impoundment unit. Based on
unit-specific data from EPA's Surface Impoundment Study (US EPA 2001 a), EPA
assumed a fixed sediment layer thickness of 20 cm at the base of the impoundment.
In addition, the EPACMTP model assumes that the depth of clogging underneath
the impoundment was 0.5 m in all cases, and that saturated hydraulic conductivity of
the clogged layer is 10% of that of the native soil underlying the impoundment.
For unlined Sis, the primary parameters that control the infiltration rate are
the ponding depth in the impoundment, the thickness and permeability of any
accumulated sediment layer at the base of the impoundment, and the presence of a
'clogged' (i.e., reduced permeability) layer of native soil under the impoundment
caused by the migration of solids from the impoundment.
For single-lined Sis, infiltration rates are typically calculated inside of
EPACMTP in the same manner as described for unlined units, with the exception
that a compacted clay liner (with a given thickness and hydraulic conductivity) is
added at the bottom of the WMU and the effect of clogged native material is not
included due to the filtering effects of the liner. For more information on the
EPACMTP inputs used to describe the SI liner thickness and conductivity, see
Sections 2.4.4.and 2.4.5.
For the composite-lined SI, the EPACMTP model determines its infiltration
rate using a default distribution of leak densities expressed as number of leaks per
hectare (see Section 2.4.7).
Parameter Value or Distribution of Values
When the EPACMTP model is run for any of the three default liners for the
surface impoundment scenario using the regional, site-based methodology, the
4-13
-------
Section 4.0
Infiltration and Recharge Parameters
model selects a site at random from those in the site data file for each Monte Carlo
realization. Using the characteristics of the chosen site and the methods described
above, the model automatically calculates the infiltration rate. The climate center
index associated with the chosen site and the randomly generated soil types are
then used to determine the recharge rate for the site from the HELP database also
included in the site data file.
The cumulative frequency distributions of SI infiltration for the three default
liner scenarios (produced by running a standard regional site-based modeling
analysis) are presented in Table 4.6; the SI infiltration rates for each climate center
are presented in Appendix A.
Table 4.6 Cumulative Frequency Distribution of Surface Impoundment
Infiltration
%
0
10
25
50
75
80
85
90
95
100
No Liner Infiltration
Rate (m/yr)
3.78E-15
2.71 E-01
5.21 E-01
1.14E+00
2.27E+00
2.58E+00
2.94E+00
3.51 E+00
4.51 E+00
2.23E+01
Clay Liner Infiltration
Rate (m/yr)
3.78E-15
4.22E-02
6.29E-02
1.08E-01
1.63E-01
1.76E-01
1.94E-01
2.17E-01
2.69E-01
7.98E-01
Composite Liner
Infiltration Rate (m/yr)
O.OOE+00
O.OOE+00
O.OOE+00
4.88E-05
2.02E-04
2.67E-04
3.55E-04
4.98E-04
7.51 E-04
3.69E-03
Data Sources
In a location-specific modeling analysis, the site-specific infiltration rate can
be directly specified in the input file - either as a constant value or as a statistical or
empirical distribution of values.
To create the surface impoundment site data file for use with EPACMTP,
EPA used unit-specific data for Sis from EPA's Surface Impoundment Study (U.S.
EPA, 2001 a). The resulting sediment layer permeability has a relatively narrow
range of variation between 1.26x10 "7 and 1.77x10 "7 cm/s. This database of surface
impoundment sites is tabulated in Appendix D.
Default data on leak density were compiled from 26 leak density values
reported in TetraTech (2001). Further details of the methodology and data used to
derive SI infiltration for the composite liner scenario are presented in Section 4.2.2.4
of the IWEM Technical Background Document (U.S. EPA, 2003c).
4-14
-------
Section 4.0 Infiltration and Recharge Parameters
Use In EPACMTP
The surface impoundment infiltration rate is used by the model to determine
the leachate flux to the subsurface and as an input to the subsurface flow and
transport modules.
4.4 RECHARGE RATE (U
Definition
The recharge rate is the rate at which water percolates through the soil to the
water table outside the footprint of the WMU. The recharge rate is determined by
regional climatic conditions, such as precipitation, evapotranspiration, surface run-
off, and regional soil type. The ambient regional rate may be different from the
infiltration rate through the WMU due to the engineering design of the unit (e.g.,
landfill cover soil of a different type, hydraulic head of the impoundment, or low
waste conductivity), topography, land use, and/or vegetation. The recharge rate is
determined by the regional climatic and soil conditions, such as precipitation,
evapotranspiration, surface run-off, and regional soil type. Note that both infiltration
and recharge are specified as areal rates, with the units of cubic meters of fluid
(water or leachate) per square meter per year (m3/m2/yr). Thus, the units for
infiltration and recharge simplify to meters per year (m/yr).
Parameter Value or Distribution of Values
EPA created the database of recharge rates for the three primary soil types
across the United States (SNL, SLT, and SCL) and ambient climate conditions at
102 climate stations through the use of the HELP water-balance model as presented
in Appendix A. The ambient regional recharge rate for a given climate center and
soil type (for all four WMU types) was assumed to be the same as the corresponding
unlined LF infiltration rate. The cumulative frequency distribution of recharge
(produced by running a standard regional site-based modeling analysis for a landfill)
are presented in Table 4.7; the recharge rate for each climate center is presented in
Appendix A.
4-15
-------
Section 4.0
Infiltration and Recharge Parameters
Table 4.7 Cumulative Frequency Distribution of Regional Recharge Rate
%
0
10
25
50
75
80
85
90
95
100
Recharge Rate (m/yr)
1.00E-05
1.35E-02
6.86E-02
1.22E-01
3.08E-01
3.42E-01
3.90E-01
4.38E-01
4.67E-01
1.15E+00
Data Sources
The HELP model was used to estimate the ambient regional recharge rate,
using the procedure described in Appendix A. Note that the recharge rate for a
given climate center and soil type (for all 4 types of WMUs) is assumed to be the
same as the corresponding unlined landfill infiltration rate (see Section 4.3.1.1).
Use In EPACMTP
When the EPACMTP model is run using the regional, site-based
methodology, the model selects a site at random from those in the site data file for
each Monte Carlo realization. The climate center index associated with the chosen
site and the randomly generated soil type are then used by the model to determine
the recharge value of the site from the HELP database also included in the site data
file.
In a location-specific modeling analysis, the site-specific regional recharge
rate can be directly specified in the input file - either as a constant value or as a
statistical or empirical distribution of values.
Once the recharge rate is generated, it is used by the model as an input to
the subsurface flow and transport modules.
4-16
-------
Section 5.0 Hydrogeological Parameters
5.0 HYDROGEOLOGICAL PARAMETERS
EPACMTP treats the subsurface aquifer system as a composite domain,
consisting of an unsaturated (vadose) zone and an underlying saturated zone (an
unconfined aquifer). The boundary between the two zones is the water table. The
unsaturated zone and saturated zone modules are computationally linked through
continuity of flow and constituent concentration across the water table directly
underneath the waste management unit (WMU). The model accounts for the
following processes affecting constituent fate and transport as the constituent
migrates from the bottom of a WMU through the unsaturated and saturated zones:
advection, hydrodynamic dispersion and molecular diffusion, linear or nonlinear
equilibrium sorption, first-order decay and zero-order production reactions (to
account for transformation breakdown products), and dilution due to recharge in the
saturated zone.
This section discusses the individual hydrogeological parameters
characterizing the soil and aquifer that are required to perform a modeling analysis
using EPACMTP. Although most applications of EPACMTP are conducted on a
national or regional basis for regulatory development purposes, EPACMTP can also
be used in a location-specific mode. In either case, each of the input parameters
describing the soil and aquifer beneath the waste site being modeled can be
specified as a constant value or as a statistical or empirical distribution of values. As
a practical matter, however, many of these inputs are commonly specified using a
distribution of values.
There are a number of data sources available to obtain parameter values for
the unsaturated and saturated zone modeling in EPACMTP. For unsaturated zone
modeling, we used a database of soil hydraulic properties for various soil types,
assembled by Carsel and Parrish (1988), in combination with information from the
Soil Conservation Service (SCS) on the nationwide prevalence of different soil types
across the United States. Another primary data source was the Hydrogeologic
Database for Ground-Water Modeling (HGDB), assembled by Rice University on
behalf of the American Petroleum Institute (API) (Newell, Hopkins, and Bedient,
1990). This database provides probability distributions of a number of key ground-
water modeling parameters for various types of subsurface environments.
The HGDB was developed from a survey of the hydrogeologic characteristics
at actual hazardous waste sites in the United States and provides site specific data
on ground water parameters (aquifer thickness, unsaturated zone thickness,
hydraulic gradient and hydraulic conductivity) collected by independent investigators
for approximately 400 hazardous waste sites throughout the U.S. These site-
specific data were then regrouped into 13 hydrogeologic environments, based on the
USGS classification of aquifer regions (Heath, 1984) (12 specific environments and
one category called "other"). The result is a database of aquifer types, with each
aquifer type consisting of an empirical distribution of values for each of the four
aquifer parameters.
5-1
-------
Section 5.0 Hydrogeological Parameters
These hydrogeological parameters are individually described in the following
sections.
5.1 HYDROGEOLOGICAL PARAMETERS
The hydrogeological input parameters include parameters to characterize
both the flow regime and constituent transport in both the unsaturated zone and
aquifer in the vicinity of the modeled WMU. These parameters are listed in Table
5.1.
5.2 UNSATURATED ZONE PARAMETERS
In the unsaturated zone, EPACMTP simulates one-dimensional, vertically
downward flow and transport of constituents between the base of the WMU and the
water table. The unsaturated zone-specific model inputs used by the model to
simulate the fate of constituents as they are transported through the subsurface
include the unsaturated zone thickness, hydraulic conductivity and other hydraulic
properties of the soil, the bulk density of the soil, the dispersivity in the unsaturated
zone, percent organic matter, and parameters describing the sorption and/or
degradation of the modeled constituent. The primary output from the unsaturated
zone module is the predicted contaminant concentration entering the saturated zone
at the water table, either as a function of time (the breakthrough curve) or at
steady-state.
These unsaturated zone parameters are individually described in the
following sections.
5.2.1 Unsaturated Zone Thickness (D,,)
Definition
The unsaturated zone thickness is the vertical distance from the ground
surface to the water table. The water table in this case is meant to represent the
'natural' water elevation, as it is or would be without the influence from the WMU.
The presence of a WMU, particularly a surface impoundment, may cause a local rise
in the water table called mounding. The EPACMTP model assumes that the
unsaturated zone thickness value you have entered does not include mounding.
The model will calculate the predicted impact of the WMU and liner design (if any)
on the ground water as part of the modeling evaluation.
Note that in cases where the WMU is excavated, such that the base of the
unit is below ground surface, the unsaturated zone thickness should be the long-
term average regional depth to ground water, measured outside the footprint of the
WMU. The input variable Depth Below Grade (see Sections 2.3.3, 2.4.6, and 2.5.3)
is used to correct the unsaturated zone thickness beneath an excavated WMU.
5-2
-------
Section 5.0
Hydrogeological Parameters
Table 5.1 Hydrogeological Parameters
Module
Unsaturated
Zone
Saturated Zone
Parameter
Unsaturated Zone
Thickness
Soil Type Index
Soil Hydraulic Conductivity
Alpha
Beta
Residual Water Content
Saturated Water Content
Soil Bulk Density
Percent Organic Matter
Dispersivity
Leading Coefficient of
Freundlich Isotherm
Exponent of Freundlich
Isotherm
Chemical Degradation
Rate
Biodegradation Rate
Soil Temperature
Soil pH
Particle Diameter
Porosity
Bulk Density
Hydrogeologic
Environment Index
Saturated Zone Thickness
Hydraulic Conductivity
Regional Hydraulic
Gradient
Seepage Velocity
Anisotropy Ratio
Retardation Coefficient
Longitudinal Dispersivity
Symbo
I
Du
ISTYPE
Ks
a
P
er
0S
Pbu
%OM
aLu
Kd
n
ACU
Abu
T
PH
d
*
Pb
IGWR
B
K
r
vx
Ar
n6
aL
Units
m
unitless
cm/hr
1/cm
unitless
unitless
unitless
g/cm3
unitless
m
cm3/g
unitless
1/yr
1/yr
°C
standard
units
cm
unitless
g/cm3
unitless
m
m/yr
unitless
m/yr
unitless
unitless
m
Section
5.2.1
5.2.2
5.2.3.1
5.2.3.2
5.2.3.3
5.2.3.4
5.2.3.5
5.2.3.6
5.2.3.7
5.2.4
5.2.5.1
5.2.5.2
5.2.6
5.2.7
5.2.8
5.2.9
5.3.1
5.3.2
5.3.3
5.3.4.2
5.3.4.3
5.3.4.4
5.3.4.5
5.3.5
5.3.6
5.3.7
5.3.8.1
Equation in
EPACMTP
Tech. Bkgd.
Doc
3.9
3.4
3.1
3.1
3.1
3.1
3.16
3.10
3.9
3.11
3.18
3.13
3.12
4.4.3.3
4.4.3.4
4.1
4.2
4.3
2.31
4.4
4.6
4.6
4.5
4.18
4.19
5-3
-------
Section 5.0
Hydrogeological Parameters
Module
CD
O
N
m
=3
CO
Parameter
Horizontal Transverse
Dispersivity
Vertical Dispersivity
Aquifer Temperature
Ground-water pH
Fractional Organic Carbon
Content
Leading Coefficient of
Freundlich Isotherm
Exponent of Freundlich
Isotherm
Chemical Degradation
Rate
Biodegradation Rate
Symbo
1
oy
av
T
pH
f3
'oc
Xs
'M
rf
Xs
Ac
Xs
A6
Units
m
m
°C
standard
units
unitless
cm3/g
unitless
1/yr
1/yr
Section
5.3.8.2
5.3.8.3
5.3.9
5.3.10
5.3.11
5.3.12
5.3.13
5.3.14
5.3.15
Equation in
EPACMTP
Tech. Bkgd.
Doc
4.28
4.29
4.4.3.3
Section
4.4.3.4
4.30
4.18
4.34
Section
4.4.3.9
Section
4.4.3.9
Parameter Value or Distribution of Values
Lacking a site-specific value or distribution of values to input, a default
distribution of unsaturated zone thickness values may be used as part of the
regional site-based modeling methodology. As described in Section 5.5 of the
EPACMTP Technical Background Document (U.S. EPA, 2003a), the regional site-
based modeling methodology is an attempt to ensure that the combination of
parameter values randomly generated by the Monte Carlo module of EPACMTP
represents a realistic set of site conditions. The cumulative frequency distribution of
unsaturated zone thickness listed in Table 5.2 was generated by performing a
default landfill modeling analysis using the regional site-based modeling
methodology; the entire Hydrogeologic Database for Modeling (HGDB) from which
these values were derived is presented in Appendix D.
5-4
-------
Section 5.0
Hydrogeological Parameters
Table 5.2 Cumulative Frequency Distribution of Unsaturated Zone Thickness
%
0
10
25
50
75
80
85
90
95
100
Unsaturated Zone Thickness (m)
3.05E-01
1.68E+00
3.96E+00
6.10E+00
1.52E+01
1.83E+01
2.93E+01
4.27E+01
5.08E+01
6.10E+02
Data Sources
EPA obtained data on the unsaturated zone thickness from the
Hydrogeologic Database for Modeling (HGDB; Newell et al., 1990; U.S. EPA,
1997d). A database of soil hydraulic properties for various soil types, assembled by
Carsel and Parrish (1988) was also used, in combination with information from the
Soil Conservation Service (SCS) on the nationwide prevalence of different soil types
across the United States. The Hydrogeologic Database for Modeling (HGDB) from
which the values shown in Table 5.2 were derived is presented in its entirety in
Appendix D.
In the regional site-based Monte Carlo analysis that is typically used for
nationwide modeling applications, the resulting distribution of values for the
thickness of the unsaturated zone is produced through Monte Carlo sampling of the
HGDB, based on the hydrogeologic environment assigned to the waste site selected
for each model realization. In a location-adjusted or quasi-site-specific modeling
analysis, the site-specific unsaturated zone thickness can be directly specified as a
constant value or an empirical or statistical distribution of values.
Use In EPACMTP
The EPACMTP model uses the unsaturated zone thickness to determine the
travel distance of leachate constituents in the unsaturated zone.
5.2.2 Soil Type (ISTYPE)
Definition
Soil type is a way to group or classify soils with similar properties. EPACMTP
incorporates three soil types, sandy loam, silt loam, and silty clay loam, that
represent the most prevalent soil types across the U.S.
5-5
-------
Section 5.0
Hydrogeological Parameters
The soil type is indicated by a numerical index which is simply a sequential
number assigned to each soil type in the default database included with EPACMTP
in order to provide a simple means of specifying which distributions should be used
to generate the input values for the soil characteristics required to run the model.
Parameter Value or Distribution of Values
The soil types for which default data are available are listed in Table 5.3; the
corresponding soil parameter distributions are summarized in Section 5.2.3. When
performing a regional site-based modeling analysis of a landfill, waste pile, or land
application unit, the soil type is randomly chosen based on the nationwide frequency
of occurrence, based on Soil Conservation Service (SCS) soil mapping data. These
percentages are shown below in Table 5.3. When performing a regional site-based
modeling analysis of a WMU, the soil type for each unit is specified in the default site
data file.
Table 5.3 Default EPACMTP Soil Types
Soil Type
Index
1
2
3
Texture
medium
coarse
fine
Soil Name
silt loam
sandy loam
silty clay
loam
Abbreviation
SLT
SNL
SCL
Frequency of
Occurrence
56.6%
15.4%
28%
Data Sources
Parameter distributions for soil parameters were compiled by Carsel and
Parrish (1988). Information on the relative frequency of each soil type was obtained
from the U.S. Soil Conservation Service as part of the risk analysis in support of
EPA's development of the Toxicity Characteristic Final Rule (U.S. EPA, 1990).
Use In EPACMTP
To perform a typical Monte Carlo analysis using the regional site-based
modeling methodology, the soil type index should be left in its default setting, ensuring
that the appropriate climatic data is used for each WMU site in the database. However,
if a location-specific analysis is being performed, then this input can either be omitted
from the input file (if site-specific values for the soil characteristics are available) or set
to the appropriate constant value to make use of the default soil data which are included
in the model.
5-6
-------
Section 5.0 Hydrogeological Parameters
5.2.3 Soil Hydraulic Characteristics
EPACMTP uses the so-called van Genuchten model to describe the soil
hydraulic characteristics. The parameters used to describe the soil hydraulic
characteristics include residual water content, saturated water content, and two van
Genuchten empirical water soil moisture parameters (alpha and beta).
Solution of the unsaturated zone flow requires knowledge of the soil characteristic
curves, i.e., the relationship between water saturation and pressure head and between
hydraulic conductivity and water saturation. The van Genuchten (1980) model is widely
used for predicting soil-water content as a function of pressure head. Descriptive
statistical values for the parameters used in this model have been determined by Carsel
and Parrish (1988) for 12 soil classifications. The statistical distributions for the
parameters presented in Carsel and Parrish (1988) (as well as the bulk density and
percent organic matter from Carsel et al., 1988) for the three default soil types used in
EPACMTP are presented in Table 5.4. The variables analyzed by Carsel and Parrish
include saturated hydraulic conductivity (Ks), residual water content (0r), saturated water
content (0S), and three empirical constants (a, (3, and 0. Probability distributions for a,
/?, and (/for all 12 soil types from Carsel and Parrish (1988) are presented in Table 5.6.
5.2.3.1 Soil Hydraulic Conductivity (KJ
Definition
The hydraulic conductivity of the soil is a measure of the soil's ability to transmit
water under fully saturated conditions.
Parameter Value or Distribution of Values
If site-specific data are available, then the soil hydraulic conductivity can be
specified as a constant value or an empirical or statistical distribution of values.
5-7
-------
Section 5.0
Hydrogeological Parameters
Table 5.4 Statistical parameters for soil properties for three soil types used in
the EPACMTP model (Carsel and Parrish, 1988 and Carsel et al., 1988).
All values are in arithmetic space
Distribution Limits of Variation Standard
Variable Tvoe Minimum Maximum Mean Deviation
Soil Type - Silty Clay Loam
Ks cm/hr
er
a cm"1
/?
%OM
Pb
0s
SB
NO
SB
NO
SB
Constant
Constant
0.
0.00
0.00
1.0
0.0
-
-
3.5
0.115
0.15
1.5
8.35
-
-
0.017
0.089
.009
1.236
0.11
1.67
0.43
2.921
0.0094
.097
0.061
5.91
-
-
Soil Type - Silt Loam
Ks cm/hr
0r
a cm"1
/?
%OM
Pb
0S
LN
SB
LN
SB
SB
Constant
Constant
0.
0.00
0.00
1.0
0.0
-
-
15.0
0.11
0.15
2.0
8.51
-
-
.343
.068
.019
1.409
0.105
1.65
0.45
.989
0.071
0.012
1.629
5.88
-
-
Soil Type - Sandy Loam
Kg cm/hr
0r
acm-1
/?
%OM
Pb
0S
SB
SB
SB
LN
SB
Constant
Constant
0.
0.
0.
1.35
0.0
-
-
30.0
0.11
0.25
3.00
11.0
-
-
2.296
0.065
0.070
1.891
0.074
1.60
0.41
24.65
0.074
0.171
0.155
7.86
-
-
%OM
NO
SB
LN
Ks
er
a,P
Pb
= Percent Organic Matter
= Normal distribution
= Log ratio distribution, Y = In [(x-A)/(B-x)], A <>
= Log normal distribution, Y = ln[x]
where Y = normal distributed parameter
x = actual data
= Saturated Hydraulic Conductivity
= Residual water content
= van Genuchten parameters
= Bulk density
= Saturated Water Content
5-8
-------
Section 5.0
Hydrogeological Parameters
Lacking site-specific data, a default distribution of soil hydraulic conductivity
values may be used as part of the regional site-based modeling methodology (see
Section 5.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
The EPACMTP model includes a database of soil characteristics for each of three
default soil types; hydraulic conductivity is one of the soil characteristics included in
these default databases. A statistical summary of the values used for each of the three
default soil types, including hydraulic conductivity, is shown in Table 5.4, above. The
cumulative frequency distribution of soil hydraulic conductivity values listed in Table 5.5
was generated by performing a default nationwide landfill modeling analysis using the
regional site-based modeling methodology. For a given percentile (%) frequency and
value pair in Table 5.5, the percentile denotes the relative frequency or likelihood of
parameter values in the entire distribution being less than or equal to the corresponding
parameter value in the right hand column.
Table 5.5 Cumulative Frequency Distribution of Soil Hydraulic Conductivity
%
0
10
25
50
75
80
85
90
95
100
Soil Hydraulic Conductivity (cm/hr)
4.30E-05
6.79E-03
2.33E-02
8.90E-02
3.99E-01
6.09E-01
9.97E-01
1.93E+00
4.41 E+00
2.79E+01
Data Sources
The databases of soil characteristics for the three default soil types (which
include soil hydraulic conductivity) were derived from soil hydraulic property data
reported by Carsel and Parrish (1988).
Use In EPACMTP
The hydraulic conductivity of the soil is used as an input to the unsaturated zone
flow module and is used to calculate the moisture content in the soil under a given rate
of leachate infiltration from the WMU.
5-9
-------
Table 5.6 Descriptive statistics for van Genuchten water retention model parameters, a, 3, and
(Carsel and Parrish, 1988)
en
o
Soil Type
Clay3
Clay Loam
Loam
Loamy Sand
Silty Clay
Silty Clay
Loam
Silt
Silt Loam
Sandy Clay
Sandy Clay
Loam
Sandy Loam
Sand
Parameter a, cm 1
X
0.008
0.019
0.036
0.124
0.005
0.010
0.016
0.020
0.027
0.059
0.075
0.145
SD
0.012
0.015
0.021
0.043
0.005
0.006
0,007
0.012
0.017
0.038
0.037
0.029
cv
160.3
77.9
57.1
35.2
113.6
61.5
45.0
64.7
61.7
64.6
49.4
20.3
N
400
363
735
315
126
641
82
109
3
46
214
118
3
246
Parameter 3
X
1.09
1.31
1.56
2.28
1.09
1.23
1.37
1.41
1.23
1.48
1.89
2.68
SD
0.09
0.09
0.11
0.27
0.06
0.06
0.05
0.12
0.10
0.13
0.17
0.29
CV
7.9
7.2
7.3
12.0
5.0
5.0
3.3
8.5
7.9
8.7
9.2
20.3
N
400
364
735
315
374
641
82
109
3
46
214
118
3
246
Parameter y
X
0.08
0.24
0.36
0.56
0.08
0.19
0.27
0.29
0.19
0.32
0.47
0.63
SD
0.07
0.06
0.05
0.04
0.05
0.04
0.02
0.06
0.06
0.06
0.05
0.04
CV
82.7
23.5
13.5
7.7
51.7
21.5
8.6
19.9
34.7
53.0
10.1
6.3
N
400
364
735
315
374
641
82
1093
46
214
1183
246
N = Sample size, X = Mean
SD = Standard Deviation
CV = Coefficient of Variation (percent)
a = Agricultural Soil, Clay 60 percent
Y= 1-1
cf
O
<-+•
§'
I
CD
O
8'
3
CD
-------
Section 5.0
Hydrogeological Parameters
5.2.3.2 Alpha (a)
Definition
Alpha is a soil-specific shape parameter that is obtained from an empirical
relationship between pressure head and volumetric water content; it is one of the
parameters in the van Genuchten (1980) model used for modeling soil-water content
as a function of pressure head, and is used to calculate the moisture content in the soil
under a given rate of leachate infiltration from the WMU.
Parameter Value or Distribution of Values
If site-specific data are available, then the van Genuchten parameter alpha can
be specified in the input file as a constant value or an empirical or statistical distribution
of values.
Lacking site-specific data, a default distribution of soil hydraulic conductivity
values may be used as part of the regional site-based modeling methodology (see
Section 5.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
The EPACMTP model includes a database of soil characteristics for each of three
default soil types; van Genuchten parameter alpha is one of the soil characteristics
included in these default databases. A statistical summary of the values used for each
of the three default soil types, including the van Genuchten parameter alpha, is shown
in Table 5.4. The cumulative frequency distribution of soil hydraulic conductivity values
listed in Table 5.7 was generated by performing a default nationwide landfill modeling
analysis using the regional site-based modeling methodology. For a given percentile
(%) frequency and value pair in Table 5.7, the percentile denotes the relative frequency
or likelihood of parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right hand column.
Table 5.7 Cumulative Frequency Distribution of Alpha
%
0
10
25
50
75
80
85
90
95
100
Alpha (1 /cm)
1.29E-03
5.96E-03
9.35E-03
1.52E-02
2.71 E-02
3.26E-02
4.22E-02
5.90E-02
8.92E-02
2.18E-01
5-11
-------
Section 5.0 Hydrogeological Parameters
Data Sources
The databases of soil characteristics for the three default soil types (which
include the van Genuchten parameter (a)) were derived from soil hydraulic property
data reported by Carsel and Parrish (1988).
Use In EPACMTP
The van Genuchten parameter alpha is an input to the unsaturated zone flow
module and is used to calculate the moisture content in the soil under a given rate of
leachate infiltration from the WMU.
5.2.3.3 Beta (B)
Definition
Beta is a soil-specific shape parameter that is obtained from an empirical
relationship between pressure head and volumetric water content; it is one of the
parameters in the van Genuchten (1980) model used for modeling soil-water content
as a function of pressure head.
Parameter Value or Distribution of Values
If site-specific data are available, then the van Genuchten parameter beta can
be specified in the input file as a constant value or an empirical or statistical distribution
of values.
Lacking site-specific data, a default distribution of soil hydraulic conductivity
values may be used as part of the regional site-based modeling methodology (see
Section 5.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
The EPACMTP model includes a database of soil characteristics for each of three
default soil types; van Genuchten parameter beta is one of the soil characteristics
included in these default databases. A statistical summary of the values used for each
of the three default soil types, including the van Genuchten parameter beta, is shown
in Table 5.4. The cumulative frequency distribution of soil hydraulic conductivity values
listed in Table 5.8 was generated by performing a default nationwide landfill modeling
analysis using the regional site-based modeling methodology. For a given percentile
(%) frequency and value pair in Table 5.8, the percentile denotes the relative frequency
or likelihood of parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right hand column.
5-12
-------
Section 5.0
Hydrogeological Parameters
Table 5.8 Cumulative Frequency Distribution of Beta
%
0
10
25
50
75
80
85
90
95
100
Beta (unitless)
1.03E+00
1.20E+00
1.27E+00
1.37E+00
1.53E+00
1.58E+00
1.68E+00
1.82E+00
1.96E+00
2.50E+00
Data Sources
The databases of soil characteristics for the three default soil types (which
include the van Genuchten parameter ((3)) were derived from soil hydraulic property
data reported by Carsel and Parrish (1988).
Use In EPACMTP
The van Genuchten parameter beta is an input to the unsaturated zone flow
module and is used to calculate the moisture content in the soil under a given rate of
leachate infiltration from the WMU.
5.2.3.4 Residual Water Content
Definition
At atmospheric pressure, the saturated water content represents the maximum
fraction of the total volume of soil that is occupied by the water contained in the soil.
The soil will remain saturated as the pressure head is gradually decreased. Eventually,
as the pressure head decreases to a threshold known as the bubbling pressure, the
water will begin to drain from the soil. The moisture content will continue to decline as
the pressure head is lowered until it reaches some irreducible residual water content.
Should the pressure head be further reduced, the soil would not lose any additional
moisture.
Parameter Value or Distribution of Values
If site-specific data are available, then the residual water content of the soil can
be specified as a constant value or an empirical or statistical distribution of values.
Lacking site-specific data, a default distribution of soil hydraulic conductivity
values may be used as part of the regional site-based modeling methodology (see
5-13
-------
Section 5.0
Hydrogeological Parameters
Section 5.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
The EPACMTP model includes a database of soil characteristics for each of three
default soil types; residual water content is one of the soil characteristics included in
these default databases. A statistical summary of the values used for each of the three
default soil types, including the residual water content of the soil, is shown in Table 5.4.
The cumulative frequency distribution of soil hydraulic conductivity values listed in Table
5.9 was generated by performing a default nationwide landfill modeling analysis using
the regional site-based modeling methodology. For a given percentile (%) frequency
and value pair in Table 5.9, the percentile denotes the relative frequency or likelihood
of parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right hand column.
Table 5.9 Cumulative Frequency Distribution of Residual Water Content
%
0
10
25
50
75
80
85
90
95
100
Residual Water Content (unitless)
1.06E-02
4.89E-02
6.09E-02
7.46E-02
8.57E-02
8.80E-02
9.07E-02
9.37E-02
9.81 E-02
1.15E-01
Data Sources
The databases of soil characteristics for the three default soil types (which
include the residual water content) were derived from soil hydraulic property data
reported by Carsel and Parrish (1988).
Use In EPACMTP
The residual water content is an input to the unsaturated zone flow module and
is used to calculate the moisture content in the soil under a given rate of leachate
infiltration from the WMU.
5-14
-------
Section 5.0
Hydrogeological Parameters
5.2.3.5 Saturated Water Content (9J
Definition
At atmospheric pressure, the saturated water content represents the maximum
fraction of the total volume of soil that is occupied by the water contained in the soil.
Parameter Value or Distribution of Values
If site-specific data are available, then the saturated water content of the soil can
be specified in the input file as a constant value or an empirical or statistical distribution
of values.
Lacking site-specific data, a default distribution of soil hydraulic conductivity
values may be used as part of the regional site-based modeling methodology (see
Section 5.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
The EPACMTP model includes a database of soil characteristics for each of three
default soil types; saturated water content is one of the soil characteristics included in
these default databases. A statistical summary of the values used for each of the three
default soil types, including the saturated water content of the soil, is shown in Table
5.4. The cumulative frequency distribution of soil hydraulic conductivity values listed in
Table 5.10 was generated by performing a default nationwide landfill modeling analysis
using the regional site-based modeling. For a given percentile (%) frequency and value
pair in Table 5.10, the percentile denotes the relative frequency or likelihood of
parameter values in the entire distribution being less than or equal to the corresponding
parameter value in the right hand column.
Table 5.10 Cumulative Frequency Distribution of Saturated Water Content
%
0
10
25
50
75
80
85
90
95
100
Saturated Water Content (unitless)
4.10E-01
4.10E-01
4.30E-01
4.50E-01
4.50E-01
4.50E-01
4.50E-01
4.50E-01
4.50E-01
4.50E-01
5-15
-------
Section 5.0 Hydrogeological Parameters
Data Sources
The databases of soil characteristics for the three default soil types (which
include the saturated water content) were derived from soil hydraulic property data
reported by Carsel and Parrish (1988).
Use In EPACMTP
The saturated water content is an input to the unsaturated zone flow module and
is used to calculate the moisture content in the soil under a given rate of leachate
infiltration from the WMU.
5.2.3.6 Soil Bulk Density
Definition
The dry bulk density of the soil is the ratio of the mass of the solid soil to its total
volume.
Parameter Value or Distribution of Values
If site-specific data are available, then the soil bulk density can be specified in
the input file as a constant value or an empirical or statistical distribution of values.
Lacking site-specific data, a default distribution of soil hydraulic conductivity
values may be used as part of the regional site-based modeling methodology (see
Section 5.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
The EPACMTP model includes a database of soil characteristics for each of three
default soil types; soil bulk density is one of the soil characteristics included in these
default databases. A statistical summary of the values used for each of the three
default soil types, including the soil bulk density, is shown in Table 5.4. The cumulative
frequency distribution of soil hydraulic conductivity values listed in Table 5.11 was
generated by performing a default nationwide landfill modeling analysis using the
regional site-based modeling methodology. For a given percentile (%) frequency and
value pair in Table 5.11, the percentile denotes the relative frequency or likelihood of
parameter values in the entire distribution being less than or equal to the corresponding
parameter value in the right hand column.
5-16
-------
Section 5.0
Hydrogeological Parameters
Table 5.11 Cumulative Frequency Distribution of Soil Bulk Density
%
0
10
25
50
75
80
85
90
95
100
Soil Bulk Density (g/cm3)
1.60E+00
1.60E+00
1.65E+00
1.65E+00
1.67E+00
1.67E+00
1.67E+00
1.67E+00
1.67E+00
1.67E+00
Data Sources
The databases of soil characteristics for the three default soil types (which
include the bulk density) were derived from soil property data reported by Carsel et al
(1988).
Use In EPACMTP
The dry soil bulk density (mass of soil per unit volume) is used to calculate the
retardation coefficient of organic constituents and to convert soil mass to volume.
5.2.3.7 Percent Organic Matter (%OM)
Definition
The percent organic matter is a measure of the organic material that is present
within the soil of the unsaturated zone, measured as a weight percent.
Parameter Value or Distribution of Values
If site-specific data are available, then the percent organic matter in the soil can
be specified in the input file as a constant value or an empirical or statistical distribution
of values.
Lacking site-specific data, a default distribution of soil hydraulic conductivity
values may be used as part of the regional site-based modeling methodology (see
Section 5.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
The EPACMTP model includes a database of soil characteristics for each of three
default soil types; hydraulic conductivity is one of the soil characteristics included in
these default databases. A statistical summary of the values used for each of the three
default soil types, including the percent organic matter in the soil, is shown in Table 5.4.
The cumulative frequency distribution of soil hydraulic conductivity values listed in Table
5-17
-------
Section 5.0
Hydrogeological Parameters
5.12 was generated by performing a default nationwide landfill modeling analysis using
the regional site-based modeling methodology. For a given percentile (%) frequency
and value pair in Table 5.12, the percentile denotes the relative frequency or likelihood
of parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right hand column.
Table 5.12 Cumulative Frequency Distribution of Percent Organic Matter
%
0
10
25
50
75
80
85
90
95
100
Percent Organic Matter
3.58E-03
1.05E-01
7.87E-02
4.05E-02
1.18E-01
1.42E-01
1.72E-01
2.15E-01
2.96E-01
1.69E+00
(unitless)
Data Sources
The databases of soil characteristics for the three default soil types (which
include the percent organic matter) were derived from soil property data reported by
Carseletal (1988).
Use In EPACMTP
For organic constituents, the percent organic matter in the soil which is specified
in the input file is internally converted by the EPACMTP model to fractional organic
carbon content through the following equation (Enfield et al., 1982):
foc= %OM/174
(5.1)
where:
'oc
%OM
174
= fractional organic carbon content,
= percent organic matter, and
= conversion factor.
Once the fractional organic carbon content is obtained, it is used to calculate the
unsaturated zone linear distribution coefficient for organic constituents (kd, see Section
5.2.8) assuming that hydrophobic binding dominates the sorption process
5-18
-------
Section 5.0 Hydrogeological Parameters
(Karickhoff, 1985). The distribution coefficient is then used to calculate the amount by
which contaminant transport is retarded relative to the ambient ground-water flow
velocity within the vadose zone.
This input is not used for modeling the transport of metals.
5.2.4 Unsaturated Zone Longitudinal Dispersivitv (a,,,)
Definition
Dispersion is the phenomenon by which a dissolved constituent in soil or ground
water is mixed with uncontaminated water and becomes reduced in concentration at the
perimeter of the plume. Not all of a constituent is traveling at the same velocity, due to
differences in pore size and flow path length and friction along pore walls, resulting in
mixing along the flow path which decreases solute concentrations. Note that the
unsaturated zone longitudinal dispersivity is measured along the path of flow, that is,
in the downward direction.
Parameter Value or Distribution of Values
The longitudinal dispersivity of the soil can be input as a constant value or a
distribution of values, if site-specific data are available. If not, the dispersivity can be
derived as a linear function of the total depth of the unsaturated zone according the
following equation which is based on a regression analysis of data presented by EPRI
(1985):
aLu = 0.02 + 0.022 Du (5.2)
where
aLu = longitudinal dispersivity (m)
Du = total depth of the unsaturated zone (m)
The cumulative frequency distribution of soil hydraulic conductivity values listed
in Table 5.13 was generated by performing a default nationwide landfill modeling
analysis using the regional site-based modeling methodology. The unsaturated zone
dispersivity was specified as a derived variable in the input file, and this distribution of
values was created through the Monte Carlo sampling of unsaturated zone thickness
from the linked WMU site and HGDB databases (see Section 5.3.4). For a given
percentile (%) frequency and value pair in Table 5.13, the percentile denotes the
relative frequency or likelihood of parameter values in the entire distribution being less
than or equal to the corresponding parameter value in the right hand column.
5-19
-------
Section 5.0
Hydrogeological Parameters
Table 5.13 Cumulative Frequency Distribution of Dispersivity
%
0
10
25
50
75
80
85
90
95
100
Dispersivity (m)
2.67E-02
5.70E-02
1.07E-01
1.54E-01
3.54E-01
4.23E-01
6.65E-01
9.59E-01
1.00E+00
1.00E+00
Data Sources
Lacking site-specific data to input, Equation 5.1 is used to calculate the unsaturated
zone dispersivity. This equation is based on a regression analysis of data presented
by EPRI (1985) (shown in Table 5.14) and has a correlation coefficient of 0.66.
Use In EPACMTP
The longitudinal dispersivity of the unsaturated zone is an input to the
unsaturated zone transport module and is used to calculate the concentration history
(breakthrough curve) of the constituent plume arriving at the water table.
5-20
-------
Section 5.0
Hydrogeological Parameters
Table 5.14 Compilation of field dispersivity values (EPRI, 1985)
Author
Yule and Gardner
(1978)
Hildebrand and Himmelblau
(1977)
Kirdaetal. (1973)
Gaudetetal. (1977)
Brissaud et al.
(1983)
Warrick et al.
(1971)
Van de Pol et al.
(1977)
Biggar and Nielsen
(1976)
Kies(1981)
Juryetal. (1982)
Andersen et al.
(1968)
Oakes(1977)
Type of
Experiment
Laboratory
Laboratory
Laboratory
Laboratory
Field
Field
Field
Field
Field
Field
Field
Field
Vertical Scale of
Experiment (m)
0.23
0.79
0.60
0.94
1.00
1.20
1.50
1.83
2.00
2.00
20.00
20.00
Longitudinal
Dispersivity
aL(m)
0.0022
0.0018
0.004
0.01
0.0011,
0.002
0.027
0.0941
0.05
0.168
0.0945
0.70
0.20
5.2.5 Freundlich Adsorption Isotherm Parameters
An adsorption isotherm is an expression of the equilibrium relationship
between the aqueous concentration and the sorbed concentration of a chemical
constituent (organic or metal) at a constant temperature. One of the general models
of the sorption process is the Freundlich isotherm, defined as follows:
where:
K
C
n
= KC'
(5.3a)
mass of constituent that is sorbed per dry unit weight of solid
(mg/kg)
Leading coefficient of the Freundlich isotherm (mg/kg)/(mg/L)n
aqueous concentration of the constituent at equilibrium with
the sorbed mass (mg/L)
Freundlich isotherm exponent (dimensionless)
5-21
-------
Section 5.0 Hydrogeological Parameters
If the sorptive behavior of a constituent can be described by the Freundlich
isotherm, then when log C is plotted against log S, the resulting relationship will be
linear with a slope of n and an intercept of log K. A special case is when //• is equal
to 1.0. In this case, the sorption isotherm is linear and the leading Freundlich
coefficient is known as the linear solid-liquid phase distribution coefficient (Kd). A
linear isotherm is commonly used to describe the subsurface fate and transport of
organic constituents, assuming that hydrophobic binding dominates the sorption
process (Karickhoff, 1985). In this case, the K^can be calculated as follows:
Kd = koc foc (5.3b)
where
Kd = leading Freundlich coefficient (distribution coefficient) (cm3/g)
koc = normalized organic carbon distribution coefficient (cm3/g)
foc = fractional organic carbon content (dimensionless)
Equation (5.3a) may be recast as:
S = (KC"-1)C = Kd(C)C (5.3c)
where:
S = mass of constituent that is sorbed per dry unit weight of solid
(mg/kg)
K = Leading coefficient of the Freundlich isotherm (mg/kg)/(mg/L)n
C = aqueous concentration of the constituent at equilibrium with
the sorbed mass (mg/L)
n = Freundlich isotherm exponent (dimensionless)
Kd = distribution coefficient (cm3/g)
The distribution coefficient, Kd, in Equation 5.3c is non-linear and is a function
of aqueous concentration. In EPACMTP, the non-linear /^function in Equation
(5.3c) may be more general than the Freundlich type (see Section 5.2.5.1) below.
To model the fate and transport of constituents with EPACMTP, the user
must specify two adsorption isotherm parameters: the Freundlich sorption
coefficient (/Cor Kd) and the Freundlich exponent (77). These two parameters are
described in Sections 5.2.5.1 and 5.2.5.2, below.
5-22
-------
Section 5.0 Hydrogeological Parameters
5.2.5.1 Leading Coefficient of Freundlich Isotherm for Unsaturated Zone
(/Cor/Q
Definition
The leading coefficient of the Freundlich isotherm is a constant used to
describe the sorptive behavior of a constituent. When the sorption data are plotted
as log C versus log S, the intercept of the resulting line is equal to log K. In the
special case of a linear isotherm, the leading Freundlich coefficient is known as the
linear solid-liquid phase distribution coefficient (Kd) (commonly called the distribution
coefficient).
Parameter Value or Distribution of Values
When modeling organic constituents with EPACMTP, the leading Freundlich
coefficient is generally specified as a derived parameter in the input file. If derived,
the leading Freundlich coefficient (Kd) is automatically assumed linear and calculated
by the model according to Equation 5.3b. In this case, foc is internally calculated
from the percent organic matter specified in the unsaturated zone-specific input
group according to Equation 5.2, and koc is a constituent-specific input value (see
Section 3 of this document). However, if site-specific data are available, a constant
value or distribution of values could be used for the leading Freundlich coefficient.
When modeling metals transport in the unsaturated zone with EPACMTP,
the leading Freundlich coefficient can be specified as a constant value or as a
distribution of values, based either on site-specific data or adsorption data reported
in the scientific literature. Alternatively, tables of non-linear sorption isotherms
developed using the MINTEQA2 geochemical model, or equations comprising pH-
based (linear) isotherms can be used. For the latter two cases (non-linear isotherms
or pH-based linear isotherms) this input parameter is not used; the record in the
input file is ignored by the model. Instead, the non-linear Kd (Equation 5.3c) is either
provided in tabular form as a function of the concentration value or calculated as a
function of pH (see Sections 3.3.3.2 and 3.3.3.1.2, respectively).
Data Sources
Generally, the Kdior organic constituents is specified as a derived parameter;
however, if this option is not appropriate and site-specific data are not available,
there are studies in the scientific literature that provide compilations of Kd's that have
been measured in the field (for instance, see Risk Assessment for the Listing
Determinations for Inorganic Chemical Manufacturing Wastes; U.S. EPA, 2000). In
this case, the leading Freundlich coefficient would be specified as either a constant
value or a distribution of values (and the Freundlich exponent would be set to its
default value of 1.0).
The leading Freundlich coefficient for metals is specified using either the
non-linear MINTEQA2 isotherms or pH-based linear isotherms that were developed
specifically for use with the EPACMTP model (see Section 3.3.3). However, if
5-23
-------
Section 5.0 Hydrogeological Parameters
neither of these two options is appropriate and site-specific data are not available,
there are studies in the scientific literature that provide compilations of Kd's that have
been measured in the field (for instance, see Appendix I of U.S. EPA, 2000). In this
case, the leading Freundlich coefficient would be specified as either a constant value
or a distribution of values.
Use In EPACMTP
The leading Freundlich coefficient (also called the distribution coefficient) is
one of the parameters used to calculate the amount by which contaminant transport
is retarded relative to the ambient ground-water flow velocity within the unsaturated
zone. It is an input to the unsaturated zone transport module. For organic
constituents that are subject to hydrolysis, this input is also used as a parameter to
calculate the overall hydrolysis rate.
5.2.5.2 Exponent of Freundlich Isotherm for Unsaturated Zone (n)
Definition
The exponent of the Freundlich isotherm is a constant used to describe the
sorptive behavior of a constituent. When the sorption data are plotted as log C
versus log S, the slope of the resulting line is equal to //•. In the special case of a
linear isotherm, the exponent of the Freundlich isotherm is equal to 1.0.
Parameter Value or Distribution of Values
For modeling organic constituents, the default value of the Freundlich
exponent is 1.0, meaning a linear adsorption isotherm is used.
Generally, the distribution coefficient for metals is specified using either
tabulated non-linear MINTEQA2 isotherms or pH-based linear isotherms that were
developed specifically for use with the EPACMTP model (see Section 3.3.3). In
these two cases, the Kd data is read in from an auxiliary input file or internally
calculated, and the Freundlich isotherm coefficient and exponent are not used. If
the leading Freundlich coefficient is specified using an empirical distribution of
values (e.g., based on reported Kd values in the scientific literature), then the
Freundlich isotherm exponent should be set equal to 1.0.
If this parameter is omitted from the data file, it is assigned a default value of
1.0, which is equivalent to specifying a linear sorption isotherm.
In EPACMTP Version 2.0, only the case of 77= 1 is permitted. Non-linear
isotherms (see Equation 5.3c) are handled using the tabular type of input described
in Section 3.3.3.2.
5-24
-------
Section 5.0 Hydrogeological Parameters
Data Sources
For modeling organic constituents, the Freundlich isotherm exponent is
generally set to its default value of 1.0, and so no specific data source is used to
determine the appropriate value for the Freundlich exponent.
For modeling metal constituents, the Freundlich isotherm exponent is not
used as an input parameter, and so no specific data source is used (see Section
3.3.3.2). If literature or site-specific data are used to specify a non-linear adsorption
isotherm, modeling of the adsorption process is implemented via tabular input
describing the relationship in Equation 5.3c.
Use In EPACMTP
The Freundlich exponent is one of the parameters used to calculate the
amount by which contaminant transport is retarded relative to the ambient ground-
water flow velocity within the unsaturated zone; it is an input to the unsaturated zone
transport module.
5.2.6 Chemical Degradation Rate Coefficient for Unsaturated Zone (A.,,.)
Definition
EPACMTP accounts for all transformation processes (both biological and
chemical) using a lumped first-order decay coefficient. This overall decay coefficient
is the sum of the chemical and biological transformation coefficients. The chemical
degradation coefficient for the unsaturated zone is simply the rate of decay that is
caused by chemical (usually hydrolysis) reactions in the unsaturated zone.
Parameter Value or Distribution of Values
By default, the chemical degradation coefficient in the unsaturated zone is
set to be internally derived using the hydrolysis rate constants and the unsaturated
zone properties according to Equation 3.4. However, if site-specific data are
available, this parameter can be specified as a constant value or a distribution of
values. In this case, the hydrolysis rate constants can be omitted from the input file.
Data Sources
If this parameter is not derived by the model, then a site-specific data source
must be used to determine the appropriate input value.
Use In EPACMTP
The chemical degradation coefficient is used by the model to calculate the
amount by which contaminant concentrations within the vadose zone are attenuated
due to chemical hydrolysis; it is an input to the unsaturated zone transport module
and is one of the parameters required to solve the transport equation for dissolved
5-25
-------
Section 5.0 Hydrogeological Parameters
leachate constituents (see Sections 3.3.4 and 4.4.4 of the EPACMTP Technical
Background Document (U.S. EPA, 2003a).
5.2.7 Biodeqradation Rate Coefficient for Unsaturated Zone
Definition
EPACMTP accounts for all transformation processes (both biological and
chemical) using a lumped first-order decay coefficient. This overall decay coefficient
is the sum of the chemical and biological transformation coefficients. The biological
degradation coefficient for the unsaturated zone is simply the rate of decay that is
caused by biological processes in the unsaturated zone.
Parameter Value or Distribution of Values
By default, the biological degradation coefficient in the unsaturated zone is
set equal to zero. However, if site-specific data are available, this parameter can be
specified as a constant value or a distribution of values.
Data Sources
If the input value of this parameter is non-zero, then a site-specific data
source must be used to determine the appropriate input value.
Use In EPACMTP
The biological degradation coefficient is used by the model to calculate the
amount by which contaminant concentrations within the vadose zone are attenuated
due to biological processes; it is an input to the unsaturated zone transport module
and is one of the parameters required to solve the transport equation for dissolved
leachate constituents (see Sections 3.3.4 and 4.4.4 of the EPACMTP Technical
Background Document (U.S. EPA, 2003a).
5.2.8 Soil Temperature (T)
Definition
The soil temperature is the long-term average temperature within the vadose
zone. Note that although the temperature within the vadose zone is not an explicit
model input, this temperature is assumed by EPACMTP to be the same as that of
the aquifer.
Parameter Value or Distribution of Values
As modeled in EPACMTP, soil temperature affects the transformation rate of
constituents that are subject to hydrolysis, through the effect of temperature on
reaction rates (see Section 3.3.2.2). In the development of the site data files for
each WMU type, information on average annual temperatures in shallow ground-
5-26
-------
Section 5.0
Hydrogeological Parameters
water systems (Todd, 1980) were used to assign a temperature value to each WMU
in the modeling database, based on the unit's geographical location. For each WMU
site, the assigned temperature was an average of the upper and lower values for
that temperature region, as shown in Figure 5.1. In other words, all WMU's located
in the band between 10° and 15° were assigned a temperature value of 12.5 °C.
Figure 5.1 Ground-water Temperature Distribution for Shallow
Aquifers in the United States (from Todd, 1980)
Data Sources
Information on average annual temperatures in shallow ground-water
systems from Todd (1980) were used to assign a temperature value to each WMU
site in the site data files, based on the unit's geographical location.
Use In EPACMTP
When the EPACMTP model is run using the regional, site-based
methodology, for each Monte Carlo realization, the model selects a site, at random,
from those in the site data file. Since the original data sets did not include all the
site-related input files required by the EPACMTP model, other data sources, such as
this map of ground-water temperatures, are utilized to create a complete data set.
For each WMU site, the ground-water temperature was assigned using the data
from Todd (1980) and the unit's geographical location.
5-27
-------
Section 5.0 Hydrogeological Parameters
In a location-adjusted modeling analysis, a site-specific ground-water
temperature can be directly specified in the input file - either as a constant value or
as a statistical or empirical distribution of values.
The aquifer temperature associated with the modeled site and the specified
hydrolysis rate constants are then used by the model to derive the appropriate
temperature-dependent first-order hydrolysis rate for organic constituents. Note that
although the temperature of the ground-water within the vadose zone is not an
explicit model input, the EPACMTP model assumes that the soil temperature is the
same as that of the aquifer.
5.2.9 Soil PH (pH)
pH is defined as the negative of the base-10 logarithm of the hydrogen ion
[H+] concentration in solution. pH is a measure of acidity. pH values below 7
indicate acidic conditions; values above 7 indicate alkaline conditions.
Parameter Value or Distribution of Values
A nationwide ground-water pH distribution was derived from EPA's STORE!
database (U.S. EPA, 1996). EPACMTP assumes that the ground water is
sufficiently buffered such that pH is not influenced by the input of contaminants or
changes in temperature. The default distribution is an empirical distribution with a
median value of 6.8 or lower and upper bounds of 3.2 and 9.7, respectively. Note
that the value generated for the ground-water pH is assumed to apply to the
unsaturated zone as well.
Data Sources
The pH data distribution was developed from nearly 25,000 field-measured
pH values in EPA's STORET water quality database (U.S. EPA, 1996). EPA used
these data to develop a pH distribution for ground water that is used in EPACMTP
for the unsaturated zone as well.
Use In EPACMTP
pH is used in the calculation of hydrolysis rates for organic constituents, in
accordance with Equation 3.6.
pH is also one of the key parameters that controls sorption and mobility of
metal constituents. When the default, MINTEQA2 sorption isotherms are used in
EPACMTP, pH is one of the key master variables that controls the selection of a
particular isotherm for each model realization in the Monte Carlo simulation process.
5.3 SATURATED ZONE PARAMETERS
In the saturated zone, EPACMTP simulates ground-water flow and three-
dimensional constituent transport from the water table to a downgradient well. The
5-28
-------
Section 5.0 Hydrogeological Parameters
saturated zone-specific inputs used by the model to simulate the fate of constituents
as they are transported through the subsurface include particle diameter, porosity,
bulk density, aquifer thickness, hydraulic conductivity, hydraulic gradient, anisotropy
ratio, dispersivity, ground-water temperature and pH, and parameters describing the
sorption and/or degradation of the modeled constituent. The primary model output
is a prediction of the constituent concentration arriving at a downgradient well.
The primary source of data for the default distributions used in the saturated
zone module is the Hydrogeologic Database for Ground-Water Modeling (HGDB),
assembled by Rice University on behalf of the American Petroleum Institute (API)
(Newell et al., 1990). This database provides probability distributions for the
following three aquifer-specific inputs for various types of subsurface environments:
aquifer thickness, hydraulic conductivity, and hydraulic gradient (data on the
unsaturated zone thickness is also included in this database, but this parameter is
discussed with the other unsaturated zone parameters in Section 5.2).
All of the saturated zone parameters are individually described in the
following sections.
5.3.1 Particle Diameter (d)
Definition
The particle diameter is defined as the mean diameter of the particles
constituting the aquifer materials.
Parameter Value or Distribution of Values
Lacking a site-specific value or distribution of values, this input value can be
specified using a default distribution of values (the default option) or it can be
derived based on the aquifer's porosity. The default distribution of values was
created from data compiled by Shea (1974) and is presented below in Table 5.15.
For a given percentile (%) frequency and value pair in this table, the percentile
denotes the relative frequency or likelihood of parameter values in the entire
distribution being less than or equal to the corresponding parameter value in the
right hand column.
Table 5.16 lists the cumulative frequency distribution of particle diameter that
is generated in a default landfill modeling analysis using the regional site-based
modeling methodology. For a given percentile (%) frequency and value pair in Table
5.16, the percentile denotes the relative frequency or likelihood of parameter values
in the entire distribution being less than or equal to the corresponding parameter
value in the right hand column.
5-29
-------
Section 5.0
Hydrogeological Parameters
Table 5.15 Empirical distribution of mean particle diameter (based on Shea,
1974)
Cumulative Probability
3.9x1 0-4
7.8x1 0'4
1.6x10'3
3.1x10'3
6.3x1 0-3
1.25x10'2
2.5x1 0'2
5.0x1 0'2
1.0x10'1
2.0x1 0'1
4.0x1 0'1
8.0x1 0'1
Particle Diameter (cm)
0.000
0.038
0.104
0.171
0.262
0.371
0.560
0.792
0.904
0.944
0.976
1.000
Table 5.16 Cumulative Frequency Distribution of Particle Diameter
%
0
10
25
50
75
80
85
90
95
100
Particle Diameter
4.00E-04
1.50E-03
5.57E-03
1.91E-02
4.09E-02
4.60E-02
5.56E-02
7.62E-02
9.73E-02
2.11E-01
(cm)
Alternatively, if the particle diameter is treated as a derived parameter, then
its value is calculated using the value of porosity (which may be constant or
randomly generated from a probability distribution) using the following empirical
relationship based on data reported by Davis (1969):
5-30
-------
Section 5.0 Hydrogeological Parameters
d = exp[ 0.261 - (frO.0385] (5.4)
where:
d = mean particle diameter (cm)
$ = total porosity (dimensionless)
Y = van Genuchten soil-specific shape parameter (dimensionless)
Data Sources
For Monte Carlo analyses, an empirical distribution of values is typically used
for the mean particle diameter. This distribution of values is based on data compiled
by Shea (1974) in which a frequency distribution of particle sizes is presented that is
based on analysis of 11,000 samples.
Alternatively, if the particle diameter is treated as a derived parameter, then
its value is calculated from the porosity using Equation 5.4 based on data reported
by Davis (1969).
Use In EPACMTP
For Monte Carlo analyses, the mean particle diameter is typically used to
calculate porosity and bulk density of the aquifer materials. Bulk density is an input
to the saturated zone flow and transport modules. In the transport module, it is one
of several parameters used to calculate the degree to which contaminant velocities
are retarded relative to the ambient ground-water flow velocity within the aquifer.
5.3.2 Porosity (d))
Definition
Porosity is the ratio of the volume of void spaces in rock or sediment to the
total volume of rock or sediment. For contaminant transport modeling, it is more
appropriate to use effective porosity, 0e, than total porosity. The effective porosity
can be significantly smaller than the total porosity. However, the EPACMTP input
parameter porosity can represent either total or effective porosity, depending upon
how it is specified, as described below.
5-31
-------
Section 5.0 Hydrogeological Parameters
Parameter Value or Distribution of Values
Lacking a site-specific value or distribution of values, this input value can be
calculated based on the aquifer's particle diameter by rewriting Equation 5.4 to solve
for porosity, as shown below:
(/> = 0.261 - 0.0385 ln(d) (5.5)
where:
d = mean particle diameter (cm)
$ = total porosity (dimensionless)
Equation 5.5 yields the total porosity of the aquifer, but for contaminant
transport modeling, it is more appropriate to use effective porosity,
-------
Section 5.0 Hydrogeological Parameters
Table 5.17 Ratio between effective and total porosity as a function of particle
diameter (after McWorter and Sunada, 1977)
Mean Particle Diameter (cm)
< 6.25 10'3
6.25 10'3-2.5 10'2
2.510-2-5.0 10'2
5.0 10'2- 1.0 10'1
> 1.0 10'1
0J0 Range
0.03 - 0.77
0.04-0.87
0.31 -0.91
0.58-0.94
0.52 - 0.95
Data Sources
If the porosity is treated as a derived parameter (the default setting), then the
total porosity is calculated from the mean particle diameter using Equation 5.5 which
is based on data reported by Davis (1969). The total porosity is then converted to
effective porosity by randomly choosing a ratio between effective and total porosity;
this conversion is accomplished through the use of ranges of values for the ratio
between effective and total porosity as a function of mean particle diameter that are
derived from data presented in McWorter and Sunada (1977).
Use In EPACMTP
For Monte Carlo analyses, the porosity, whether directly input or derived, is
used to calculate the bulk density of the aquifer materials. Bulk density is an input to
the saturated zone flow and transport modules. In the saturated zone flow module,
bulk density is used in the calculation of the ground-water seepage velocity. In the
transport module, bulk density is one of several parameters used to calculate the
degree to which contaminant velocities are retarded relative to the ambient ground-
water flow velocity within the aquifer.
5.3.3 Bulk Density
Definition
Bulk density is defined as the mass of aquifer solid material per unit volume
of the aquifer, in g/cm3 or mg/L. Bulk density takes into account the fraction of the
volume that is taken up by pore space.
Parameter Value or Distribution of Values
Lacking site-specific data for bulk density, this input can be derived from the
porosity of the aquifer. Assuming the particle density to be 2.65 g/cm3, the bulk
density can be calculated using the following equation from Freeze and Cherry
(1979):
5-33
-------
Section 5.0
Hydrogeological Parameters
p = 2.85 ( 1-
(5.6)
where
pb = bulk density of the soil (g/cm3).
$ = total porosity of the aquifer material (dimensionless)
Table 5.18 lists the cumulative frequency distribution of bulk density that is
generated in a default landfill modeling analysis using the regional site-based
modeling methodology. For a given percentile (%) frequency and value pair in Table
5.18, the percentile denotes the relative frequency or likelihood of parameter values
in the entire distribution being less than or equal to the corresponding parameter
value in the right hand column.
Table 5.18 Cumulative Frequency Distribution of Bulk Density
%
0
10
25
50
75
80
85
90
95
100
Soil Bulk Density (g/cm3)
1.16E+00
1.30E+00
1.43E+00
1.56E+00
1.63E+00
1.64E+00
1.66E+00
1.70E+00
1.72E+00
1.80E+00
Data Sources
In the absence of a site specific value or distribution of values for bulk
density, this input can be specified as a derived parameter in the EPACMTP input
file. In this case, the input value is calculated from the aquifer porosity by assuming
the particle density to be 2.65 g/cm3 and using the relationship from Freeze and
Cherry (1979) that is presented as Equation 5.6.
Use In EPACMTP
Bulk density is an input to the saturated zone flow and transport modules. In
the saturated zone flow submodule, bulk density is used in the calculation of the
ground-water seepage velocity. In the transport flow submodule, bulk density is one
of several parameters used to calculate the degree to which contaminant velocities
are retarded relative to the ambient ground-water flow velocity within the aquifer.
5-34
-------
Section 5.0
Hydrogeological Parameters
5.3.4 Aquifer Characteristics
In the absence of site-specific data to input, default distributions of correlated
values can be used in EPACMTP for the following aquifer characteristics:
1. Depth to ground water;
2. Saturated zone thickness;
3. Saturated zone hydraulic conductivity; and
4. Saturated zone hydraulic gradient.
These default distributions are derived from the Hydrogeologic Database for
Ground-Water Modeling (HGDB), assembled by Rice University on behalf of the
American Petroleum Institute (API) (Newell et al., 1990). The data in this
hydrogeological database were collected by independent investigators for
approximately 400 hazardous waste sites throughout the United States; the
geographical locations of these sites are shown in Figure 5.2 (p. 5-37). In the
HGDB, the data are grouped into twelve subsurface environments, which are based
on EPA's DRASTIC classification of hydrogeologic settings (U.S. EPA, 1985). Table
5.19 lists these hydrogeologic environments, and a brief description of each
environment is presented in Section 5.3.4.2. Table 5.19 includes a total of 13
categories; 12 are distinct subsurface environments, while the 13th category, which is
labeled "other" or "unknown", was used for waste sites that could not be classified
into one of the first 12 environments. The subsurface parameter values in this 13th
category are simply averages of the parameter values in the 12 actual subsurface
environments. The resulting database of aquifer types, with each aquifer type
consisting of an empirical distribution of values for each of the four aquifer
parameters, is presented in its entirety in Appendix D.
Table 5.19 HGDB Hydrogeologic Environments (from Newell et al., 1990)
Region
Description
1
2
3
4
5
6
7
8
9
10
11
12
13
Metamorphic and Igneous
Bedded Sedimentary Rock
Till Over Sedimentary Rock
Sand and Gravel
Alluvial Basins Valleys and Fans
River Valleys and Flood Plains with Overbank Deposits
River Valleys and Flood Plains without Overbank
Deposits
Outwash
Till and Till Over Outwash
Unconsolidated and Semi-consolidated Shallow
Aquifers
Coastal Beaches
Solution Limestone
Other (Not classifiable)
5-35
-------
Section 5.0 Hydrogeological Parameters
The key feature of this database is that it provides a set of correlated values
of the four parameters for each of the 400 sites in the database. That is, the value
of each parameter is associated with the three other subsurface parameters
reported for the same site. The regional site-based modeling methodology in
EPACMTP preserves these correlations because having information on some
parameters allows us to develop more accurate estimates for missing parameter
values. As described in Section 5.5 of the EPACMTP Technical Background
Document (U.S. EPA, 2003a), the regional site-based modeling methodology is an
attempt to ensure that the combination of parameter values that are randomly
generated by the Monte Carlo module of EPACMTP represents a realistic set of site
conditions. This methodology is called 'regional site-based' because waste site
databases are linked by each site's geographic location and underlying aquifer type
to regional databases of climatic and subsurface parameters, respectively. In this
way, the regional site-based approach attempts to approximate the ideal situation
where we have a complete set of the site-specific input data required to run the
EPACMTP model for each waste site in a statistically valid subset of the universe of
waste management units in the United States.
In developing the regional site-based modeling methodology in EPACMTP,
the U.S. EPA used the HGDB in conjunction with a geographical classification of
aquifers developed by the United States Geological Survey (Heath, 1984) to assign
each waste site in our nationwide database of Subtitle D WMU's (see Section 2.2) to
one of the 13 subsurface environments included in the HGDB. For each type of
WMU, we used information on its location (see Figures 2.2 - 2.5), in combination
with USGS state-by-state aquifer maps to determine the type of subsurface
environment at that site. Sites that could not be classified into one of the 12
categories were assigned as "other" (that is, they were assigned to environment
number 13). The regional site-based modeling methodology in EPACMTP is then
used to assign a probability distribution of hydrogeologic parameter values to each
WMU location. This methodology is consistent with the methodology used to assign
HELP-derived infiltration and recharge rates to each waste site in our nationwide
database of Subtitle D WMU's (see Section 4.2 and Appendix A).
5-36
-------
Section 5.0
Hydrogeological Parameters
\J>* \ »
,,-W >
.«"-.
* *
*
* »J-
Figure 5.2 Geographical distribution of sites in the API-HGDB data base
(Reproduced from API, 1989)
5-37
-------
Section 5.0 Hydrogeological Parameters
5.3.4.1 Methodology
Fundamentally, the approach used for a site-based Monte Carlo analysis
consists of conducting the modeling analysis for the existing sites in our nationwide
database of Subtitle D WMU's (see Section 2.2) on the assumption that these sites
are an adequate representation of the universe of possible waste sites in the U.S.
Since the original data sets (derived from the 1986 Subtitle D Survey (U.S. EPA,
1986) and the Surface Impoundment Study (U.S. EPA, 2001 a) only include the area,
volume, location and relative weight of the facility, other data sources were utilized to
determine the additional input parameters required by the EPACMTP model.
As summarized above, the ground-water parameter values are generated
using the existing WMU parameter databases (which assign each waste site to a
climate region and a hydrogeologic environment) together with the HGDB database
of hydrogeologic parameters and the databases of HELP-derived infiltration and
recharge rates. These databases are all included in an auxiliary input file called the
site data file. The following is a description of how the regional, site-based modeling
methodology is used to generate these hydrogeologic parameter values during the
course of a typical Monte Carlo analysis for nationwide assessment purposes:
• For each Monte Carlo realization, EPACMTP selects a WMU site, at
random, from the database of WMU sites. The original databases of
WMU sites from which the data in the site data file were compiled
included the facility location, area and volume. The EPACMTP model
samples the sites in the site data files with replacement, i.e., the
same site may be selected more than once. The probability of
selecting a specific site depends on the relative weight assigned to
that site in the original survey. Note that even if the same site is
sampled more than once during the course of a Monte Carlo analysis
in EPACMTP, the specific values of infiltration rate, hydrogeologic
parameters, and receptor well location will still vary; likewise, the
resulting receptor well concentration value will change, as well.
Given the waste site's geographic location, the climatic region in
which the site is located was identified and added to the WMU site
database in the EPACMTP site data file. For landfills, waste piles,
and land application units, the climatic region, the generated soil type,
and the liner design (if any) are then used by the model to determine
the infiltration rate of the site. In the no-liner and single-clay liner
scenarios, these infiltration rates are determined using the database
of rates generated with the HELP water balance model. For the
composite liner scenario, these infiltration rates are internally
calculated by the model using the relationships described in Sections
4.3.1 and 4.3.2. For surface impoundments (all liner scenarios), the
infiltration rates are internally calculated by the model using the
relationships described in Sections 4.3.4. For all WMU types, the
climatic region and the generated soil type are used by the model to
determine the ambient regional recharge rate of the site.
5-38
-------
Section 5.0 Hydrogeological Parameters
• Given the waste site's geographic location, the aquifer underlying the
site was classified (using USGS state ground-water resources
inventory maps) and added to the WMU site database in the
EPACMTP site data file. The hydrogeologic parameters for the site
are determined by selecting at random a set of aquifer characteristics
(depth to ground water, aquifer thickness, hydraulic gradient, and
hydraulic conductivity) from those available in the HGDB database for
that hydrogeologic environment. In the case where the selected set
of aquifer characteristics has missing values, a joint probability
distribution (derived for each ground-water region) is used to
generate the missing value as a function of the known values.
• The remaining parameters for the waste site (e.g., x, y and z
coordinates of the receptor well) are generated according to their
specifications in the input file. The ground-water flow and transport
modules are then used to compute the resulting receptor well
concentration for the site.
• These steps are then repeated for the desired number of iterations to
yield a distribution of receptor well concentrations which represent the
nationwide distribution of drinking water exposure concentrations.
These modeling results can then be directly used in a forward risk
calculation, or they can be post-processed to yield the ground-water
dilution-attenuation factor (DAF) that can be used in a backward risk
calculation to calculate an allowable threshold for the waste or
leachate concentration.
5.3.4.2 Hvdroqeoloqic Environment (IGWR)
Definition
The different hydrogeologic environments are represented in EPACMTP by
means of a numerical index. The hydrogeologic environment index is simply a
sequential number assigned to each hydrogeologic environment in the default
database included with EPACMTP in order to provide a simple means of specifying
which correlated set of aquifer characteristics should be used to model the given
WMU site.
Parameter Value or Distribution of Values
To perform a standard Monte Carlo analysis using the regional site-based
modeling methodology, the hydrogeologic environment index should be left in its
default setting which will ensure that the appropriate climatic data is used for each
WMU site in the database. However, if a location-adjusted or a quasi-site-specific
analysis is being performed, then this input can either be omitted from the input file
(if site-specific infiltration and recharge rates are available) or set to the appropriate
5-39
-------
Section 5.0 Hydrogeological Parameters
constant value to make use of the default set of aquifer characteristics which are
included in the site data file.
The text boxes on the following pages provide a summary of the
characteristics of each hydrogeologic environment.
5-40
-------
Section 5.0 Hydrogeological Parameters
Hydrogeologic Environment Descriptions
1) Igneous and Metamorphic Rocks
This hydrogeologic environment is underlain by consolidated bedrock of volcanic origin. This hydrogeologic
environment setting is typically associated with steep slopes on the sides of mountains, and a thin soil cover.
Igneous and metamorphic rocks generally have very low porosities and permeabilities This hydrogeologic
environment can occur throughout the United States, but is most prevalent in the western US.
2) Bedded Sedimentary Rock
Sedimentary rock is formed through erosion of bedrock. Deposited layers of eroded material may later be buried
and compacted to form sedimentary rock. Generally, the deposition is not continuous but recurrent, and sheets of
sediment representing separate events come to form distinct layers of sedimentary rock. Typically, these deposits
are very permeable and yield large quantities of ground water. Examples of this hydrogeologic environment setting
are found throughout the United States.
3) Till Over Sedimentary Rock
This hydrogeologic environment is found in glaciated regions in the northern United States which are frequently
underlain by relatively flat-lying consolidated sedimentary bedrock consisting primarily of sandstone, shale,
limestone, and dolomite. The bedrock is overlain by glacial deposits which consist chiefly of till, a dense unsorted
mixture of soil and rock particles deposited directly by ice sheets. Ground water occurs both in the glacial deposits
and in the sedimentary bedrock. Till deposits often have low permeability.
4) Sand and Gravel
Sediments are classified into three categories based upon their relative sizes; gravel, consisting of particles that
individually may be boulders, cobbles or pebbles; sand, which may be very coarse, coarse, medium, fine or very
fine; and mud, which may consist of clay and various size classes of silt. Sand and gravel hydrogeologic
environments are very common throughout the United States and frequently overlie consolidated and semi-
consolidated sedimentary rocks. Sand and gravel aquifers have very high permeabilities and yield large quantities
of ground water.
5) Alluvial Basins, Valleys and Fans
Thick alluvial deposits in basins and valleys bordered by mountains typify this hydrogeologic environment. Alluvium
is a general term for clay, silt, sand and gravel that was deposited during comparatively recent geologic time by a
stream or other body of running water. The sediments are deposited in the bed of the stream or on its flood plain or
delta, or in fan shaped deposits at the base of a mountain slope. Alluvial basins, valleys and fans frequently
occupy a region extending from the Puget Sound-Williamette Valley area of Washington and Oregon to west
Texas. This region consists of alternating basins or valleys and mountain ranges. The surrounding mountains,
and the bedrock beneath the basins, consist of granite and metamorphic rocks. Ground water is obtained mostly
from sand and gravel deposits within the alluvium. These deposits are interbedded with finer grained layers of silt
and clay.
6) River Alluvium with Overbank Deposits
This hydrogeologic environment is characterized by low to moderate topography and thin to moderately thick
sediments of flood-deposited alluvium along portions of a river valley. The alluvium is underlain by either
unconsolidated sediments or fractured bedrock of sedimentary or igneous/metamorphic origin. Water is obtained
from sand and gravel layers which are interbedded with finer grained alluvial deposits. The alluvium typically
serves as a significant source of water. The flood plain is covered by varying thicknesses of fine-grained silt and
clay, called overbank deposits. The overbank thickness is usually greater along major streams and thinner along
minor streams but typically averages 5 to 10 feet.
5-41
-------
Section 5.0 Hydrogeological Parameters
Hydrogeologic Environment Descriptions (continued)
7) River Alluvium without Overbank Deposits
This hydrogeologic environment is identical to the River Alluvium with Overbank Deposits environment
except that no significant fine-grained flood plain deposits occupy the stream valley. The lack of fine
grained deposits may result in significantly higher recharge in areas with ample precipitation.
8) Outwash
Sand and gravel removed or "washed out" from a glacier by streams is termed outwash. This
hydrogeologic environment is characterized by moderate to low topography and varying thicknesses of
outwash that overlie sequences of fractured bedrock of sedimentary, metamorphic or igneous origin.
These sand and gravel outwash deposits typically serve as the principal aquifers within the area. The
outwash also serves as a source of regional recharge to the underlying bedrock.
9) Till and Till Over Outwash
This hydrogeologic environment is characterized by low topography and outwash materials that are
covered by varying thicknesses of glacial till. The till is principally unsorted sediment which may be
interbedded with localized deposits of sand and gravel. Although ground water occurs in both the
glacial till and in the underlying outwash, the outwash typically serves as the principal aquifer because
the fine grained deposits have been removed by streams. The outwash is in direct hydraulic
connection with the glacial till and the glacial till serves as a source of recharge for the underlying
outwash.
10) Unconsolidated and Semi-consolidated Shallow Surficial Aquifers
This hydrogeologic environment is characterized by moderately low topographic relief and gently
dipping, interbedded unconsolidated and semi-consolidated deposits which consist primarily of sand,
silt and clay. Large quantities of water are obtained from the surficial sand and gravel deposits which
may be separated from the underlying regional aquifer by a low permeability or confining layer. This
confining layer typically "leaks", providing recharge to the deeper zones.
11) Coastal Beaches
This hydrogeologic environment is characterized by low topographic relief, near sea-level elevation and
unconsolidated deposits of water-washed sands. The term beach is appropriately applied only to a
body of essentially loose sediment. This usually means sand-size particles, but could include gravel.
Quartz particles usually predominate. These materials are well sorted, very permeable and have very
high potential infiltration rates. These areas are commonly ground-water discharge areas although
they can be very susceptible to the intrusion of saltwater.
12) Solution Limestone
Large portions of the central and southeastern United States are underlain by limestones and
dolomites in which the fractures have been enlarged by solution. Although ground water occurs in
both the surficial deposits and in the underlying bedrock, the limestones and dolomites, which typically
contain solution cavities, generally serve as the principal aquifers. This type of hydrogeologic
environment is often described as "karst."
13) Unknown Environment
If the subsurface hydrogeological environment is unknown, or it is different from any of the twelve main
types used in EPACMTP, select the subsurface environment as Type 13. In this case, EPACMTP will
assign values of the hydrogeological parameters (depth to ground water, saturated zone thickness,
saturated zone hydraulic conductivity, and saturated zone hydraulic gradient) that are simply national
average values.
5-42
-------
Section 5.0 Hydrogeological Parameters
Data Sources
In the absence of site-specific data, default distributions of values can be
used for the following aquifer characteristics: depth to ground water and aquifer
thickness, hydraulic conductivity, and hydraulic gradient. These default distributions
are derived from the Hydrogeologic Database for Ground-Water Modeling (HGDB),
assembled by Rice University on behalf of the American Petroleum Institute (API)
(Newell et al., 1990) and are linked to the WMU sites in the site data file using the
hydrogeologic environment index.
Use In EPACMTP
EPACMTP includes a database of aquifer characteristics for 13
hydrogeologic environments. The hydrogeologic environment index is a sequential
number assigned to each hydrogeologic environment in the default database
included with EPACMTP in order to provide a simple means of specifying which
correlated set of aquifer characteristics should be used to model the given WMU site
using the regional site-based modeling methodology.
5.3.4.3 Saturated Zone Thickness (B)
Definition
The saturated zone thickness is the vertical thickness of the zone in which
the voids in the rock or soil are filled with water at a pressure greater than
atmospheric. In an unconfined aquifer such as that simulated by the EPACMTP
model, the water table is at the top of the saturated zone. Usually the base of the
saturated zone is an impermeable layer, e.g., bedrock.
Parameter Value or Distribution of Values
If site-specific data are available, then the saturated zone thickness can be
specified in the input file as a constant value or an empirical or statistical distribution
of values. In this case, if your site has a highly stratified hydrogeology, it may be
difficult to precisely define the "base of the aquifer," but the stratification may
effectively limit the vertical plume travel distance, so it may be appropriate to enter
the maximum vertical extent of the plume as an "effective" saturated zone thickness.
Lacking site-specific data, a default distribution of saturated zone thickness
values may be used as part of the regional site-based modeling methodology. As
described in Section 5.5 of the EPACMTP Technical Background Document (U.S.
EPA, 2003a), the regional site-based modeling methodology is an attempt to ensure
that the combination of parameter values that is randomly generated by the Monte
Carlo module of EPACMTP represents a realistic set of site conditions. The
cumulative frequency distribution of saturated zone thickness listed in Table 5.20
was generated by performing a default landfill modeling analysis using the regional
site-based modeling methodology; the entire Hydrogeologic Database for Modeling
(HGDB) from which these values were derived is presented in Appendix D. For a
5-43
-------
Section 5.0
Hydrogeological Parameters
given percentile (%) frequency and value pair in Table 5.20, the percentile denotes
the relative frequency or likelihood of parameter values in the entire distribution
being less than or equal to the corresponding parameter value in the right hand
column.
Table 5.20 Cumulative Frequency Distribution of Saturated Zone Thickness
%
0
10
25
50
75
80
85
90
95
100
Saturated Zone Thickness
3.05E-01
4.27E+00
7.62E+00
1.43E+01
3.24E+01
4.83E+01
6.66E+01
9.14E+01
1.52E+02
9.14E+02
(m)
Data Sources
In the regional site-based Monte Carlo analysis used for nationwide modeling
applications, the distribution of values for the thickness of the saturated zone is
produced through Monte Carlo sampling of the HGDB, based on the hydrogeologic
environment assigned to the waste site selected (from the default database) for
each model realization. The HGDB (Newell et al., 1990; U.S. EPA, 1997d) is an
empirical database of aquifer characteristics developed from a survey of hazardous
waste sites in the United States that provides data on hydrogeologic parameters
(aquifer thickness, unsaturated zone thickness, hydraulic gradient and hydraulic
conductivity) that are required by the EPACMTP model. The HGDB from which the
values shown in Table 5.20 were derived is presented in its entirety in Appendix D.
In a location-specific modeling analysis, saturated zone thickness must be
derived from a site-specific data source and specified in the input file as a constant
value or an empirical or statistical distribution of values.
Use In EPACMTP
The thickness of the saturated zone is an input to the saturated zone flow
module. It is used in EPACMTP to describe the thickness of the ground-water zone
over which the leachate plume can mix with ground water and impacts the dilution
rates in the saturated zone.
5-44
-------
Section 5.0
Hydrogeological Parameters
5.3.4.4 Hydraulic Conductivity (K)
Definition
Hydraulic conductivity is a measure of the ability to transmit water under a
unit hydraulic gradient.
Parameter Value or Distribution of Values
If site-specific data are available, then the hydraulic conductivity can be
specified in the input file as a constant value or an empirical or statistical distribution
of values.
Lacking site-specific data, a default distribution of hydraulic conductivity
values may be used as part of the regional site-based modeling methodology. As
described in Section 5.5 of the EPACMTP Technical Background Document (U.S.
EPA, 2003a), the regional site-based modeling methodology is an attempt to ensure
that the combination of parameter values that is randomly generated by the Monte
Carlo module of EPACMTP represents a realistic set of site conditions. The
cumulative frequency distribution of hydraulic conductivity listed in Table 5.21 was
generated by performing a default nationwide landfill modeling analysis using the
regional site-based modeling methodology; the entire Hydrogeologic Database for
Modeling (HGDB) from which these values were derived is presented in Appendix D.
For a given percentile (%) frequency and value pair in Table 5.21, the percentile
denotes the relative frequency or likelihood of parameter values in the entire
distribution being less than or equal to the corresponding parameter value in the
right hand column.
Table 5.21 Cumulative Frequency Distribution of Hydraulic Conductivity
%
0
10
25
50
75
80
85
90
95
100
Hydraulic Conductivity (m/yr)
3.15E+00
1.73E+02
8.04E+02
1.89E+03
1.10E+04
1.39E+04
2.21 E+04
3.15E+04
7.48E+04
4.29E+06
Alternatively, the hydraulic conductivity can be specified as a derived
parameter. In this case it is calculated within EPACMTP from the particle diameter
using the Kozeny-Carman equation (Bear, 1979) shown below:
5-45
-------
Section 5.0 Hydrogeological Parameters
K=
ju (1-f) 1.8 (5.7)
where:
K = hydraulic conductivity (cm/s)
p = density of water (kg/m3)
g = acceleration due to gravity (m/s2)
jj = dynamic viscosity of water (N-s/m2)
d = mean particle diameter (m)
$ = total porosity of the aquifer material (dimensionless)
In Equation 5.7 shown above, the constant 1.8 includes a unit conversion
factor to yield Km units of cm/s. Both the density and the dynamic viscosity of water
are functions of temperature and are computed using the regression equations
presented in CRC (1981).
Data Sources
In the regional site-based Monte Carlo analysis used for nationwide modeling
applications, the distribution of values for the hydraulic conductivity is produced
through Monte Carlo sampling of the HGDB, based on the hydrogeologic
environment assigned to the waste site selected (from the default database) for
each model realization. The HGDB (Newell et al., 1990; U.S. EPA, 1997d) is an
empirical database of aquifer characteristics developed from a survey of hazardous
waste sites in the United States that provides data on hydrogeologic parameters
(aquifer thickness, unsaturated zone thickness, hydraulic gradient and hydraulic
conductivity) that are required by the EPACMTP model. The HGDB from which the
values shown in Table 5.21 were derived is presented in its entirety in Appendix D.
If specified as a derived parameter, the aquifer hydraulic conductivity is
calculated from the mean particle diameter using the Kozeny-Carman equation
(Bear, 1979).
In a location-specific modeling analysis, hydraulic conductivity must be
derived from a site-specific data source and specified in the input file as a constant
value or an empirical or statistical distribution of values.
Use In EPACMTP
The aquifer hydraulic conductivity is an input to the saturated zone flow
module. The hydraulic conductivity, together with the hydraulic gradient, controls the
ground-water flow rate. Assigning a low hydraulic conductivity value will not
necessarily result in lower predicted ground-water exposures. In a broader sense, it
means that siting a WMU in a low permeability aquifer setting is not always more
protective than a high permeability setting. Low ground-water velocity means that it
5-46
-------
Section 5.0 Hydrogeological Parameters
will take longer for the exposure to occur, and as a result, there is more opportunity
for natural attenuation to degrade contaminants. However, for long-lived waste
constituents, it also means that little dilution of the plume may occur.
5.3.4.5 Regional Hydraulic Gradient (r)
Definition
Hydraulic gradient measures the head difference between two points as a
function of their distance. For an unconfined aquifer such as that modeled with
EPACMTP, the hydraulic gradient is simply the slope of the water table in a
particular direction. It is calculated as the difference in the elevation of the water
table measured at two locations divided by the distance between the two locations.
In EPACMTP, this parameter represents the average horizontal ground-water
gradient in the vicinity of the WMU location. The gradient is meant to represent the
'natural' ground-water gradient as it is, or would be, without influence from the WMU.
The presence of a WMU, particularly a surface impoundment, may cause local
mounding of the water table and associated higher local ground-water gradients.
The EPACMTP model assumes that the gradient value specified in the input file
does not include mounding; rather, the model will calculate the predicted impact on
the ground water of the WMU and liner design (if any) as part of the modeling
evaluation.
Parameter Value or Distribution of Values
If site-specific data are available, then the regional hydraulic gradient can be
specified in the input file as a constant value or an empirical or statistical distribution
of values.
Lacking site-specific data, a default distribution of regional hydraulic gradient
values may be used as part of the regional site-based modeling methodology. As
described in Section 5.5 of the EPACMTP Technical Background Document (U.S.
EPA, 2003a), the regional site-based modeling methodology is an attempt to ensure
that the combination of parameter values that is randomly generated by the Monte
Carlo module of EPACMTP represents a realistic set of site conditions. The
cumulative frequency distribution of regional hydraulic gradient listed in Table 5.22
was generated by performing a default nationwide landfill modeling analysis using
the regional site-based modeling methodology; the entire Hydrogeologic Database
for Modeling (HGDB) from which these values were derived is presented in
Appendix D. For a given percentile (%) frequency and value pair in Table 5.22, the
percentile denotes the relative frequency or likelihood of parameter values in the
entire distribution being less than or equal to the corresponding parameter value in
the right hand column.
5-47
-------
Section 5.0
Hydrogeological Parameters
Table 5.22 Cumulative Frequency Distribution of Regional hydraulic gradient
%
0
10
25
50
75
80
85
90
95
100
Regional Hydraulic Gradient
2.00E-06
9.00E-04
2.00E-03
5.70E-03
1.51E-02
2.00E-02
2.46E-02
3.10E-02
4.90E-02
4.91 E-01
(unitless)
Data Sources
In the regional site-based Monte Carlo analysis used for nationwide modeling
applications, the distribution of values for the regional hydraulic gradient is produced
through Monte Carlo sampling of the HGDB, based on the hydrogeologic
environment assigned to the waste site selected (from the default database) for
each model realization. The HGDB (Newell et al., 1990; U.S. EPA, 1997d) is an
empirical database of aquifer characteristics developed from a survey of hazardous
waste sites in the United States that provides data on hydrogeologic parameters
(aquifer thickness, unsaturated zone thickness, hydraulic gradient and hydraulic
conductivity) that are required by the EPACMTP model. The HGDB from which the
values shown in Table 5.22 were derived is presented in its entirety in Appendix D.
In a location-specific modeling analysis, regional hydraulic gradient must be
derived from a site-specific data source and specified in the input file as a constant
value or an empirical or statistical distribution of values.
Use In EPACMTP
The hydraulic gradient and the hydraulic conductivity (see Section 5.3.4.4)
are inputs to the saturated zone flow module, and together they control the ground-
water flow rate, in accordance with Darcy's Law. The effect of varying ground-water
flow rate on contaminant fate and transport is complex. Intuitively, it would seem
that factors that increase the ground-water flow rate would cause a higher ground-
water exposure level at the receptor well, but this is not always the case. A higher
ground-water velocity will cause leachate constituents to arrive at the well location
more quickly. For constituents that are subject to degradation in ground water, the
shorter travel time will cause the constituents to arrive at the well at higher
concentrations as compared to a case of low ground-water velocity and long travel
times. On the other hand, a high ground-water flow rate will tend to increase the
degree of dilution of the leachate plume, due to mixing and dispersion. This will in
turn tend to lower the magnitude of the concentrations reaching the well. The
5-48
-------
Section 5.0 Hydrogeological Parameters
modeling scenario evaluated in EPACMTP is based on the maximum constituent
concentrations at the well (either a peak concentration or the maximum time-
averaged concentration), rather than how long it might take for that exposure to
occur. Therefore, a higher ground-water flow rate may result in lower predicted
exposure levels at the well.
5.3.5 Seepage Velocity (VJ
Definition
Seepage velocity is the average linear velocity of a water particle in a ground
water system. It is equal to the Darcy velocity divided by effective porosity.
Parameter Value or Distribution of Values
The ground-water seepage velocity is related to the aquifer properties
through Darcy's law. The regional seepage velocity may be input directly, as a
constant value or a distribution of values. If site specific data are not available, it
may be specified in the input file as a derived parameter. In this case, it is computed
as:
Vx= Kx r (5.8)
where
Vx = longitudinal ground water seepage velocity (in the x-direction) (m/yr)
Kx = longitudinal hydraulic conductivity (in the x-direction) (m/yr)
r = regional hydraulic gradient (dimensionless)
(|)e = effective porosity (dimensionless)
Default lower and upper bounds for the seepage velocity are 0.1 and 1.1x104
m/yr, respectively. This range of values is based on survey data reported by Newell
etal(1990).
The cumulative frequency distribution for the seepage velocity listed in Table
5.23 was generated by performing a default nationwide landfill modeling analysis
using the regional site-based modeling methodology. For a given percentile (%)
frequency and value pair in this table, the percentile denotes the relative frequency
or likelihood of parameter values in the entire distribution being less than or equal to
the corresponding parameter value in the right hand column.
5-49
-------
Section 5.0
Hydrogeological Parameters
Table 5.23 Cumulative Frequency Distribution of Ground-water Seepage
Velocity
%
0
10
25
50
75
80
85
90
95
100
Seepage Velocity (m/yr)
2.17E+00
5.99E+00
5.11E+00
4.08E+01
6.73E+02
4.02E+02
2.53E+00
6.57E+00
2.27E+00
4.13E+01
Data Sources
In the regional site-based Monte Carlo analysis that is typically used for
nationwide modeling applications, the seepage velocity is, by default, internally
derived using the correlated values for hydraulic conductivity and gradient that are
produced through Monte Carlo sampling of the HGDB, based on the hydrogeologic
environment assigned to the waste site selected for each model realization. The
default lower and upper bounds for this input are based on survey data reported by
Newell etal (1990).
If specified as a derived parameter, the regional ground-water seepage
velocity is calculated from the hydraulic conductivity and gradient, and the aquifer
porosity using Equation 5.8 with upper and lower bounds based on survey data
reported by Newell et al (1990).
In a location-adjusted or quasi-site-specific modeling analysis, the site-
specific hydraulic gradient must be derived from a site-specific data source and
specified in the input file as a constant value or an empirical or statistical distribution
of values.
Use In EPACMTP
The seepage velocity that is provided as an EPACMTP input parameter
represents ambient ground water flow conditions, that is, without the WMU present.
The EPACMTP saturated zone flow module calculates the final distribution of
seepage velocities in the model domain, taking into account infiltration from the
WMU. These calculated seepage velocities are then used in the saturated zone
transport module to simulate the fate and transport of leachate constituents.
5-50
-------
Section 5.0 Hydrogeological Parameters
5.3.6 Anisotropy Ratio (A,)
Definition
The anisotropy ratio is a factor used to specify the relationship between the
horizontal and vertical aquifer hydraulic conductivities. It is defined as the ratio of
the horizontal hydraulic conductivity to the vertical hydraulic conductivity.
Parameter Value or Distribution of Values
Although the aquifer properties are assumed to be uniform, the EPACMTP
model can accommodate the situation where the horizontal and vertical aquifer
hydraulic conductivities are different. The anisotropy ratio is a factor used to specify
the relationship between these two hydraulic conductivity values and is defined
according to the following equation:
Ar= KX/KZ (5.9)
where:
Ar = anisotropy ratio = K/KZ.
Kx = hydraulic conductivity in the x direction (m/yr)
Kz = hydraulic conductivity in the z direction (m/yr)
The default value of Ar is 1, which indicates an isotropic system. Note that in
the EPACMTP model, the horizontal transverse hydraulic conductivity is assumed to
be equal to the horizontal longitudinal conductivity, i.e., Ky = Kx.
Data Sources
Because anisotropy ratios observed in the field may commonly be on the
order of 100:1 or even larger (Freeze and Cherry, 1979), a uniform distribution of Ar
with limits of 1 and 100 may be reasonable for some applications of the model.
However, for nationwide assessment purposes, the default value of Ar is 1, which
indicates an isotropic system.
Use In EPACMTP
The anisotropy ratio is used to estimate the vertical conductivity from the
horizontal conductivity. However, by default, the vertical conductivity is set equal to
the horizontal conductivity. The horizontal and vertical conductivities are inputs to
the saturated zone flow module.
5-51
-------
Section 5.0 Hydrogeological Parameters
5.3.7 Retardation Coefficient for the Saturated Zone (Rs)
Definition
The retardation coefficient is a measure of the degree to which contaminant
velocities are retarded relative to that of the bulk mass of ground water within the
aquifer. A value of 1 .0 indicates that the constituent is conservative; in other words,
it is not subject to adsorption and travels at the same speed as the bulk mass of
ground-water. Values greater than 1 .0 indicate that the constituent transport is
retarded due to adsorption.
Parameter Value or Distribution of Values
In most modeling applications using EPACMTP, the retardation coefficient is
specified as a derived variable; however, if site-specific data are available, this input
parameter can be set to a constant value or a distribution of values.
For constituents modeled with a linear adsorption isotherm (typically, organics and
metals modeled with a pH-dependent isotherm or a constant kd value), when the
retardation coefficient is specified as a derived variable in the EPACMTP input file, it
is calculated according to the following equation:
(5.10)
where
Rs = retardation coefficient for the saturated zone (dimensionless)
pb = bulk density of the porous media [g/cm3]
kd = distribution coefficient [cm3/g]
$ = porosity
For constituents modeled with a nonlinear adsorption isotherm (that is, fl8 is
no longer constant but is a function of metal concentration), ff must be specified in
the input file as a derived variable and the /^concentration relation must be
specified by the user in one of two ways: 1) in terms of the two Freundlich
parameters (k1 and 77; see Sections 5.3.12 and 5.3.13); or 2) in terms of the
tabulated MINTEQA2-derived isotherms (see Section 3.3.3.2).
For the modeling of metals, the EPACMTP user has three options for
specifying the relationship between dissolved and adsorbed concentrations: 1)
MINTEQA2-derived non-linear isotherms, 2) pH-dependent empirical isotherms, or
3) an empirical distribution of values. In the case of the first option, the non-linear
isotherm is only used in the unsaturated zone; a linear sorption isotherm (e.g., an
effective /Rvalue) is used for the saturated zone. This effective /Rvalue is
determined from the maximum contaminant concentration at the water table and
5-52
-------
Section 5.0 Hydrogeological Parameters
values of the five environmental master variables (pH, iron-oxide, leachate organic
matter, natural organic matter in the aquifer, and ground water environment type
(carbonate or non-carbonate)), following the procedure described in Appendix B.
Data Sources
Lacking site-specific data, Equation 5.10 is used to calculate the retardation
coefficient for constituents that are modeled using a linear adsorption isotherm. For
constituents modeled with a non-linear adsorption isotherm, the effective retardation
coefficient is calculated inside EPACMTP, based upon the nonlinear concentration-
Kd relationship as given by MINTEQA2-derived isotherms.
Use In EPACMTP
The retardation coefficient is an input to the saturated zone transport module.
5.3.8 Dispersivitv
The transport of the contaminant plume in the saturated zone is controlled by
two mechanisms: advection and dispersion. The EPACMTP saturated zone flow
module simulates both of these mechanisms. Dispersion is the phenomenon by
which a constituent plume in flowing ground water is mixed with uncontaminated
water and becomes reduced in concentration at the perimeter of the plume. Not all
of a contaminant plume is traveling at the same velocity due to differences in pore
size and flow path length and friction along pore walls, resulting in mixing along the
flow path which decreases solute concentrations. Note that the saturated zone
dispersivity is measured in three directions: longitudinal (along the flow path, or in
the x-direction), horizontal transverse (perpendicular to the flow path, or in the y-
direction), and vertical (in the z-direction).
The model computes the longitudinal, horizontal transverse, and vertical
dispersion coefficients as the product of the seepage velocity and longitudinal (aL),
transverse (ar) and vertical (av) dispersivities. A literature review indicated the
absence of a generally accepted theory to describe dispersivities, although a strong
dependence on scale has been noted (EPFtl, 1985; Gelhar, Welty, and Rehfeldt,
1992). In the absence of user-specified values or distributions, the longitudinal
dispersivity is represented through a probabilistic formulation and the horizontal
transverse and vertical dispersivities are, by default, calculated from the longitudinal
dispersivity, as described below.
For non-degrading contaminants, the dilution caused by dispersive mixing is
a controlling factor in determining the concentration observed at a receptor well.
However, in Monte Carlo analyses involving varying well location, the predicted
maximum well concentration is relatively insensitive to dispersion. The reason for
this is as follows: low dispersivities will lead to a compact, concentrated plume. If
the plume is relatively small, the likelihood that the receptor well will intercept the
plume is reduced, but the concentration in the well, if it does, will be high. High
dispersivities will lead to a more dilute plume which occupies a greater volume,
5-53
-------
Section 5.0 Hydrogeological Parameters
thereby increasing the likelihood that a receptor well will intercept the plume.
Concentrations in the plume, however, are likely to be lower than in the first case. In
the course of a full Monte Carlo analysis, these effects will tend to compensate for
each other.
5.3.8.1 Longitudinal Dispersivitv (aL)
Definition
Dispersion is the phenomenon by which a contaminant plume in flowing
ground water is mixed with uncontaminated water and becomes reduced in
concentration at the perimeter of the plume. The longitudinal dispersivity is the
characteristic length that defines spatial extent of dispersion of contaminants,
measured in the longitudinal direction, that is, along the flow path or in the x-
direction.
Parameter Value or Distribution of Values
If site-specific data are available, then the longitudinal dispersivity can be
specified in the input file as a constant value or an empirical or statistical distribution
of values.
In the absence of site-specific data, the longitudinal dispersivity is, by default,
represented through a probabilistic formulation as shown in Table 5.24, and the
horizontal transverse and vertical dispersivities are then calculated from the
longitudinal dispersivity. The distribution shown in Table 5.24 is based on data
presented in EPFtl (1985). For a given percentile (%) frequency and value pair in
this table, the percentile denotes the relative frequency or likelihood of parameter
values in the entire distribution being less than or equal to the corresponding
parameter value in the right hand column. Within each of the three classes shown in
Table 5.24, the longitudinal dispersivity is assumed to be uniform. Note that the
values of longitudinal dispersivity in this table are based on a receptor well distance
of 152.4 m. For distances other than 152.4 m, the following equations are used:
= aRef(xt=152.4)(xt/152.4f5 (5.11)
where: xt= 0.5xw+xr (5.12)
5-54
-------
Section 5.0
Hydrogeological Parameters
aL = longitudinal dispersivity (m)
xt = average travel distance in the x direction (m)
xw = length of the WMU in the x-direction (parallel to ground water
flow) (m)
xm = distance from the downgradient boundary of the WMU to the
receptor well (m)
aRef = reference longitudinal dispersivity, as determined from the
probabilistic distribution (m)
Table 5.24 Probabilistic representation of longitudinal dispersivity
%
0
10
70
100
aL(m)*
0.1
1.0
10.0
100.0
*Assumes xt = 152.4 m (see Equation 5.11)
In other words, the travel distance xt is equal to the distance between the
receptor well and the downgradient facility boundary (xj, plus one-half of the facility
dimension. The average distance for all of the contaminants to migrate to the edge
of the waste management unit is equal to one half the length of the unit or 1/2 x^
The default minimum value of aL is 0.1 m.
Table 5.25 lists the cumulative frequency distribution of longitudinal
dispersivity that is generated in a default landfill modeling analysis using the regional
site-based modeling methodology. For a given percentile (%) frequency and value
pair in this table, the percentile denotes the relative frequency or likelihood of
parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right hand column.
Table 5.25 Cumulative Frequency Distribution of Longitudinal Dispersivity
%
0
10
25
50
75
80
85
90
95
100
Longitudinal Dispersivity (m)
1.00E-01
1.22E+00
3.62E+00
8.96E+00
2.54E+01
4.32E+01
6.53E+01
9.21 E+01
1.35E+02
3.18E+02
5-55
-------
Section 5.0 Hydrogeological Parameters
Data Sources
The relationship in Equation 5.11 was derived based on a professional
review of data presented in EPRI (1985). More recently, Gelhar et al. (1992) have
compiled and documented results from a large number of studies in which
dispersivity values have been reported. These studies represent a wide range of
spatial scales, from a few meters to more than 10,000 meters. The data as
presented by Gelhar et al. (1992) show a clear correlation between scale and
apparent dispersivity. Equation 5.11 used in EPACMTP describes the observed
data reasonably well. The field data suggest a somewhat steeper slope of the
distance-dispersivity relation on a log-log scale than is used in the modeling
analyses. However, a sensitivity analysis performed using EPACMTP
(HydroGeoLogic, 1992) has shown that the model results are virtually identical when
the slope is varied from 0.5 to 1.5. For this reason the original relationship as shown
in Equation 5.11 has been retained.
The data presented by Gelhar et al. (1992) also show that the ratios between
longitudinal, and horizontal and vertical transverse dispersivities used in the
nationwide modeling, are consistent with published data.
Use In EPACMTP
The longitudinal dispersivity is an input to the saturated zone transport
module.
5.3.8.2 Horizontal Transverse Dispersivitv (aT)
Definition
Dispersion is the phenomenon by which a contaminant plume in flowing
ground water is mixed with uncontaminated water and becomes reduced in
concentration at the perimeter of the plume. The horizontal transverse dispersivity is
the characteristic length that defines spatial extent of dispersion of contaminants,
measured in the horizontal transverse direction, that is, perpendicular to the flow
path, or in the y-direction.
Parameter Value or Distribution of Values
If site-specific data are available, then the horizontal transverse dispersivity
can be specified in the input file as a constant value or an empirical or statistical
distribution of values.
In the absence of site-specific data, the horizontal transverse dispersivity is,
by default, calculated from the longitudinal dispersivity using the following equation:
5-56
-------
Section 5.0
Hydrogeological Parameters
(XT= (XL/8
(5.13)
where:
aL = longitudinal dispersivity (m)
ay = horizontal transverse dispersivity (m)
Note that in EPACMTP, the input value for ar is actually the ratio of aL to ar.
Although the user can define a different value for the ratio of the longitudinal to the
transverse dispersivity, the ratio of aL/aT= 8 is used by default.
Table 5.26 lists the cumulative frequency distribution of horizontal transverse
dispersivity that is generated in a default landfill modeling analysis using the regional
site-based modeling methodology. For a given percentile (%) frequency and value
pair in this table, the percentile denotes the relative frequency or likelihood of
parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right hand column.
Table 5.26 Cumulative Frequency Distribution of Horizontal Transverse
Dispersivity
%
0
10
25
50
75
80
85
90
95
100
Horizontal Transverse Dispersivity (m)
1.25E-02
1.53E-01
4.52E-01
1.12E+00
3.17E+00
5.40E+00
8.16E+00
1.15E+01
1.69E+01
3.97E+01
Data Sources
By default, the transverse (aT) dispersivity is calculated by the EPACMTP
model as a fraction of the longitudinal dispersivity. The dispersivity relationship
described above has been derived based on a professional review of data presented
in EPRI (1985). More recently, Gelhar et al. (1992) have compiled and documented
results from a large number of studies in which dispersivity values have been
reported. The data presented by Gelhar et al. (1992) show that this default ratio
between longitudinal and horizontal transverse dispersivities is consistent with
published data.
5-57
-------
Section 5.0 Hydrogeological Parameters
Use In EPACMTP
The horizontal transverse dispersivity is an input to the saturated zone
transport module.
5.3.8.3 Vertical Dispersivitv (av)
Definition
Dispersion is the phenomenon by which a contaminant plume in flowing
ground water is mixed with uncontaminated water and becomes reduced in
concentration at the perimeter of the plume. The vertical dispersivity is the
characteristic length that defines spatial extent of dispersion of contaminants,
measured vertically downward or in the z-direction.
Parameter Value or Distribution of Values
If site-specific data are available, then the vertical dispersivity can be
specified in the input file as a constant value or an empirical or statistical distribution
of values.
In the absence of site-specific data, the vertical dispersivity is, by default,
calculated from the longitudinal dispersivity using the following equation:
(Xv= (XL/160 (5.14)
where:
aL = longitudinal dispersivity (m)
av = vertical dispersivity (m)
Note that in EPACMTP, the input value for av is actually the ratio of aL to av.
Although the user can define a different value for the ratio of the longitudinal to the
vertical dispersivity, the ratio of aL/av = 160 is used by default.
Table 5.27 lists the cumulative frequency distribution of horizontal transverse
dispersivity that is generated in a default landfill modeling analysis using the regional
site-based modeling methodology. For a given percentile (%) frequency and value
pair in this table, the percentile denotes the relative frequency or likelihood of
parameter values in the entire distribution being less than or equal to the
corresponding parameter value in the right hand column.
5-58
-------
Section 5.0
Hydrogeological Parameters
Table 5.27 Cumulative Frequency Distribution of Vertical Dispersivity
%
0
10
25
50
75
80
85
90
95
100
Vertical Dispersivity (m)
1.00E-02
1.00E-02
2.26E-02
5.60E-02
1.58E-01
2.70E-01
4.08E-01
5.76E-01
8.45E-01
1.99E+00
Data Sources
By default, the vertical (av) dispersivity is calculated by the EPACMTP model
as a fraction of the longitudinal dispersivity. The dispersivity relationship described
above has been derived based on a review of available data. More recently, Gelhar
et al. (1992) have compiled and documented results from a large number of studies
in which dispersivity values have been reported. The data presented by Gelhar et al.
(1992) show that this default ratio between longitudinal and vertical dispersivities is
consistent with published data.
Use In EPACMTP
The vertical dispersivity is an input to the saturated zone transport module;
dispersion in the saturated zone generally tends to decrease contaminant
concentrations at the receptor well.
5.3.9 Aquifer Temperature (T)
Definition
The aquifer temperature is the long-term average temperature of the ground
water within the aquifer. Note that although the temperature of the ground water
within the vadose zone is not an explicit model input, this temperature is assumed by
EPACMTP to be the same as that of the aquifer.
Parameter Value or Distribution of Values
As modeled in EPACMTP, aquifer temperature affects the transformation
rate of constituents that are subject to hydrolysis, through the effect of temperature
on reaction rates (see Section 3.3.2.2). In the development of the site data files for
each WMU type, information on average annual temperatures in shallow ground-
water systems (Todd, 1980) to assign a temperature value to each WMU in the
5-59
-------
Section 5.0
Hydrogeological Parameters
modeling database, based on the unit's geographical location. For each WMU site,
the assigned temperature was an average of the upper and lower values for that
temperature region, as shown in Figure 5.3. In other words, all WMU's located in
the band between 10° and 15° were assigned a temperature value of 12.5 °C.
Figure 5.3 Ground-water Temperature Distribution for Shallow
Aquifers in the United States (from Todd, 1980)
Data Sources
We used information on average annual temperatures in shallow ground-
water systems from Todd (1980) to assign a temperature value to each WMU site in
the site data files, based on the unit's geographical location.
Use In EPACMTP
When the EPACMTP model is run using the regional, site-based
methodology, the model selects a site at random from those in the site data file for
each Monte Carlo realization. For each WMU site, the ground-water temperature
was assigned using the data from Todd, (1980) and the unit's geographical location.
In a location-adjusted modeling analysis, a site-specific ground-water
temperature can be directly specified in the input file - either as constant value or as
a statistical or empirical distribution of values.
5-60
-------
Section 5.0 Hydrogeological Parameters
The aquifer temperature associated with the modeled site and the specified
hydrolysis rate constants are then used by the model to derive the appropriate
temperature-dependent first-order hydrolysis rate for organic constituents. Note that
although the temperature of the ground water within the vadose zone is not an
explicit model input, the EPACMTP model assumes that the soil temperature is the
same as that of the aquifer.
5.3.10 Ground-water pH (pH)
Definition
A measure of the acidity or alkalinity of the ground water, pH is measured on
a scale of 0 to 14, with 7 representing a neutral state. Values less than 7 are acidic,
and values greater than 7 are basic. pH is calculated as the negative logarithm of
the concentration of hydrogen ions in a solution. For modeling purposes, the
EPACMTP model assumes subsurface pH value is the same in the unsaturated
zone and saturated zone.
Parameter Value or Distribution of Values
If site-specific data are available, then the ground-water pH can be specified
in the input file as a constant value or an empirical or statistical distribution of values.
Lacking site-specific data, a default distribution of pH values may be used.
This pH distribution was obtained through analysis of nearly 25,000 field-measured
pH values of uncontaminated ground water obtained from EPA's STORET database
(U.S. EPA, 1996). The data are represented by an empirical distribution with low
and high values of 3.2 and 9.7, respectively and a median value of 6.8. Because the
STORET database has unrealistic extreme values (presumably from errors in
instrument calibration or reading, or in data entry), the upper and lower bounds of
the distribution were established by reference to reported values in the open
literature. The resulting pH distribution is shown in Table 5.28. For a given
percentile (%) frequency and value pair in this table, the percentile denotes the
relative frequency or likelihood of parameter values in the entire distribution being
less than or equal to the corresponding parameter value in the right hand column.
5-61
-------
Section 5.0
Hydrogeological Parameters
Table 5.28 Probability distribution of aquifer pH
%
0
10
25
50
75
80
85
90
95
100
Ground-water pH (standard units)
4.32E+00
7.49E+00
7.30E+00
8.91 E+00
7.84E+00
7.43E+00
4.65E+00
7.42E+00
5.74E+00
4.87E+00
Note that these values generated for the ground-water pH is assumed to
apply to the unsaturated zone as well. The EPACMTP model assumes that the
ground-water/aquifer system is well buffered with respect to pH. That is, in the
modeling analysis, there is no effect on the ambient pH from the leachate emanating
from the base of the WMU. Additionally, the generated pH value is assumed to
apply to both the unsaturated zone and saturated zone.
Data Sources
The distribution of pH values shown in Table 5.28 was obtained through
analysis of nearly 25,000 field measured pH values of uncontaminated ground water
obtained from EPA's STORET database (U.S. EPA, 1996). Note that the upper and
lower bounds of this distribution were established by reference to reported values in
the open literature.
Use In EPACMTP
The ground-water pH is one of the most important subsurface parameters
controlling the mobility of metals. Most metals are more mobile under acidic (low
pH) conditions, as compared to neutral or alkaline (pH of 7 or higher) conditions.
The pH may also affect the hydrolysis rate of organic constituents; some
constituents degrade more rapidly or more slowly as pH varies. The pH of most
aquifer systems is slightly acidic, the primary exception being aquifers in solution
limestone settings. These may also be referred to as 'karst', 'carbonate' or 'dolomite'
aquifers. The ground water in these systems is usually alkaline.
5-62
-------
Section 5.0 Hydrogeological Parameters
5.3.11 Fractional Organic Carbon Content (£/)
Definition
The nature and amount of solid matter in the subsurface to which chemical
constituents are attracted (the adsorbent) are important in determining the extent to
which a constituent's transport through the ground-water pathway is retarded due to
adsorption. Paniculate organic matter present in the saturated zone (input to
EPACMTP as fraction organic carbon) represents one of the dominant adsorbents
for sorption of both organic and metal constituents in environmental systems and
was one of the geochemical master variables used in the calculation of the non-
linear sorption isotherms using the MINTEQA2 model.
Parameter Value or Distribution of Values
If site-specific data are available, then the fractional organic carbon content
of the aquifer can be specified in the input file as a constant value or an empirical or
statistical distribution of values.
Lacking site-specific data, a default distribution of values may be used.
Unfortunately, few if any comprehensive subsurface characterizations of organic
carbon content exist. In general, the reported values are low, typically less than
0.01. For the purposes of modeling organic constituents, a low range of values was
assumed and the distribution shape was based on the distribution of measured
dissolved organic carbon recorded in EPA's STORE! data base. The default
distribution for fractional organic carbon content is a Johnson SB distribution with a
mean and standard deviation in arithmetic space of 4.32x10"4 and 0.0456,
respectively and upper and lower limits of 0.064 and 0.0, respectively. In the case of
metals, the sorption is controlled by complex geochemical interactions which are
simulated using MINTEQA2 (see Section 3.3.3.2 and Appendix B), and this
distribution of fnr is not used.
'oc
A summary of this default distribution is presented in Table 5.29. For a given
percentile (%) frequency and value pair in this table, the percentile denotes the
relative frequency or likelihood of parameter values in the entire distribution being
less than or equal to the corresponding parameter value in the right hand column.
5-63
-------
Section 5.0
Hydrogeological Parameters
Table 5.29 Probability distribution of fraction organic carbon in the saturated
zone
%
0
10
25
50
75
80
85
90
95
100
Fractional Organic Carbon Content
6.77E-04
4.11E-03
8.51 E-04
1.10E-04
4.71 E-04
7.82E-04
3.01 E-04
9.99E-04
5.99E-04
7.93E-04
(unitless)
Data Sources
The default distribution for foc was derived based on professional judgement
and the distribution shape was based on the distribution of measured dissolved
organic carbon recorded in EPA's STORET database.
Use In EPACMTP
The organic carbon content, foc, is used to determine the linear distribution
coefficient, Kd. This approach is valid only for organic contaminants containing
hydrophobic groups since these constituents tend to sorb preferentially on non-polar
natural organic compounds in the soil or aquifer. In the case of metals, the organic
matter content in the subsurface is one of the controlling master variables used to
develop the MINTEQA2-derived isotherms, and EPACMTP uses this organic matter
content to select appropriate isotherms to use during the EPACMTP simulation
process.
5.3.12 Leading Coefficient of Freundlich Isotherm for Saturated Zone (K/)
Definition
The leading coefficient of the Freundlich isotherm is a constant used to
describe the sorptive behavior of a constituent. When the sorption data are plotted
as log C versus log S, the intercept of the resulting line is equal to log K3. In the
special case of a linear isotherm, the leading Freundlich coefficient is known as the
linear solid-liquid phase distribution coefficient (Kds) (commonly called the
distribution coefficient).
5-64
-------
Section 5.0 Hydrogeological Parameters
Parameter Value or Distribution of Values
When modeling organic constituents with EPACMTP, the leading Freundlich
coefficient is generally specified as a derived parameter in the input file. If derived,
the leading Freundlich coefficient (Kds) is automatically assumed linear and
calculated by the model according to Equation 5.3b. In this case, foc is specified in
the aquifer-specific input group according to Equation 5.2, and koc is a constituent-
specific input value (see Section 3.3.2.1). However, if site-specific data are
available, a constant value or distribution of values could be used for the leading
Freundlich coefficient.
When modeling metals transport in the saturated zone with EPACMTP, the
leading Freundlich coefficient can be specified as a constant value or as a
distribution of values, either based on site-specific data or adsorption data reported
in the scientific literature. Another option is to specify sorption according to
equations comprising p/-/-based (linear) isotherms. In this case, this input parameter
is not used; that is, this record in the input file is ignored by the model. Instead, the
Kds (Equation 5.3c) is calculated as a function of pH(see Section 3.3.3.1.2).
Alternatively, if tables of non-linear sorption isotherms developed using the
MINTEQA2 geochemical model are used to model transport in the unsaturated
zone, then a single Kds value is chosen from these tabulated data to be used in the
aquifer. As implemented in EPACMTP, the non-linearity of the isotherms is most
important in the unsaturated zone where the concentrations are relatively high.
Upon reaching the water table and mixing the leachate with ambient ground water,
the metal's concentration is considered to be low enough that a linear isotherm can
always be used. The appropriate saturated zone Kds value is automatically chosen
by the model based on the maximum ground-water concentration under the source.
In this case as well, this input parameter is not used; that is, this record in the input
file is ignored by the model. Instead, the Kds (Equation 5.3c) is chosen from
tabulated data (see Sections 3.3.3.2 and 5.3.13 and Appendix B).
Data Sources
Generally, the Kds for organic constituents is specified as a derived
parameter; however, if this option is not appropriate and site-specific data are not
available, there are studies in the scientific literature that provide compilations of Kds
values that have been measured in the field (for instance, see Risk Assessment for
the Listing Determinations for Inorganic Chemical Manufacturing Wastes; U.S. EPA,
2000). In this case, the leading Freundlich coefficient would be specified as either a
constant value or a distribution of values (and the Freundlich exponent would be set
to its default value of 1.0).
The leading Freundlich coefficient for metals is generally superceded by use
of either the MINTEQA2-derived sorption data or the pH-based linear isotherms that
were developed specifically for use with the EPACMTP model (see Section 3.3.3).
However, if neither of these two options is appropriate and site-specific data are not
available, there are studies in the scientific literature that provide compilations of Kd's
5-65
-------
Section 5.0 Hydrogeological Parameters
that have been measured in the field (for instance, see Appendix I of U.S. EPA,
2000). In this case, the leading Freundlich coefficient would be specified as either a
constant value or a distribution of values.
Use In EPACMTP
The leading Freundlich coefficient (also called the distribution coefficient) is
one of the parameters used to calculate the amount by which contaminant transport
is retarded relative to the ambient ground-water flow velocity within the aquifer. It is
an input to the saturated zone transport module.
5.3.13 Exponent of Freundlich Isotherm for Saturated Zone (ns)
Definition
The exponent of the Freundlich isotherm is a constant used to describe the
sorptive behavior of a constituent. When the sorption data are plotted as log C
versus log S, the slope of the resulting line is equal to rf. In the special case of a
linear isotherm, the exponent of the Freundlich isotherm is equal to 1.0.
Parameter Value or Distribution of Values
For modeling organic constituents, the default value of the Freundlich
exponent is 1.0, meaning a linear adsorption isotherm is used.
When modeling metals transport in the saturated zone with EPACMTP, the
distribution coefficient for metals is generally specified using either tabulated non-
linear MINTEQA2 isotherms or pH-based linear isotherms that were developed
specifically for use with the EPACMTP model (see Section 3.3.3). In these two
cases, the Kd data is either read in from an auxiliary input file or internally calculated,
and the Freundlich isotherm coefficient and exponent are not used. If the leading
Freundlich coefficient is specified using an empirical distribution of values (e.g.,
based on reported Kd values in the scientific literature), then the Freundlich isotherm
exponent should be set equal to 1.0.
If this parameter is omitted from the data file, it is assigned a default value of
1.0, which is equivalent to specifying a linear sorption isotherm.
In EPACMTP Version 2.0, only the case of 77= 1 is permitted. Non-linear
isotherms (see Equation 5.3c) to describe metals transport are used only in the
unsaturated zone and are handled using the tabular type of input described in
Section 3.3.3.2 and Appendix B.
5-66
-------
Section 5.0 Hydrogeological Parameters
Data Sources
For modeling organic constituents, the Freundlich isotherm exponent is
generally set to its default value of 1.0, and so no specific data source is used to
determine the appropriate value for the Freundlich exponent.
For modeling metal constituents, the Freundlich isotherm exponent is not
used as an input parameter, and so no specific data source is used (see Section
3.3.3.2). If literature or site-specific data are used to specify a non-linear adsorption
isotherm, modeling of the adsorption process is implemented via tabular input
describing the relationship in Equation 5.3c.
Use In EPACMTP
The Freundlich exponent is one of the parameters used to calculate the
amount by which contaminant transport is retarded relative to the ambient ground-
water flow velocity within the aquifer; it is an input to the saturated zone transport
module.
5.3.14 Chemical Degradation Rate Coefficient for Saturated Zone (A,es)
Definition
EPACMTP accounts for all transformation processes (both biological and
chemical) using a lumped first-order decay coefficient. This overall decay coefficient
is the sum of the chemical and biological transformation coefficients. The chemical
degradation coefficient for the saturated zone is simply the rate of decay that is
caused by chemical reactions (usually hydrolysis) in the saturated zone.
Parameter Value or Distribution of Values
By default, the chemical degradation coefficient in the saturated zone is set
to be internally derived using the hydrolysis rate constants and the saturated zone
properties according to Equation 3.4. However, if site-specific data are available,
this parameter can be specified as a constant value or a distribution of values. In
this case, the hydrolysis rate constants can be omitted from the input file.
Data Sources
If this parameter is not derived by the model, then a site-specific data source
must be used to determine the appropriate input value.
Use In EPACMTP
The chemical degradation coefficient is used by the model to calculate the
amount by which ground-water concentrations are attenuated due to chemical
hydrolysis; it is an input to the saturated zone transport module and is one of the
5-67
-------
Section 5.0 Hydrogeological Parameters
parameters required to solve the advection-dispersion equation (see Sections 3.3.4
and 4.4.4 of the EPACMTP Technical Background Document (U.S. EPA, 2003a).
5.3.15 Biodeqradation Rate Coefficient for Saturated Zone (A,bs)
Definition
EPACMTP accounts for all transformation processes (both biological and
chemical) using a lumped first-order decay coefficient. This overall decay coefficient
is the sum of the chemical and biological transformation coefficients. The biological
degradation coefficient for the saturated zone is simply the rate of decay that is
caused by biological processes in the saturated zone.
Parameter Value or Distribution of Values
By default, the biological degradation coefficient in the saturated zone is set
equal to zero. However, if site-specific data are available, this parameter can be
specified as a constant value or a distribution of values.
Data Sources
If the input value of this parameter is non-zero, then a site-specific data
source must be used to determine the appropriate input value.
Use In EPACMTP
The biological degradation coefficient is used by the model to calculate the
amount by which ground-water concentrations are attenuated due to biological
processes; it is an input to the saturated zone transport module and is one of the
parameters required to solve the advection-dispersion equation (see Sections 3.3.4
and 4.4.4 of the EPACMTP Technical Background Document (U.S. EPA, 2003a).
5-68
-------
Section 6.0
Receptor Well Parameters
6.0 RECEPTOR WELL PARAMETERS
A receptor well is a hypothetical drinking water well that is located
downgradient of the waste management unit in consideration. It represents the
location at which the potential exposure to the ground water is measured.
Discussed in this section are the EPACMTP input parameters which govern the
generation and constraining of the receptor well location. These include Monte
Carlo parameters that the user can specify. These parameters can be used to apply
(or not apply) particular constraints on parameter values or generation methodology.
6.1 RECEPTOR WELL PARAMETERS
The parameters listed below in Table 6.1 are used to define the
characteristics of the downgradient receptor well.
Table 6.1 Receptor Well Parameters
Parameter
Radial Distance to
Receptor Well
Angle of Well Off of Plume
Centerline
Downgradient Distance to
Receptor Well
Well Distance From
Plume Centerline
Rra Origination Method
Constraint on Well
Distance From Plume
Centerline
Depth of Intake Point
Below Watertable
Constraint on Depth of
Intake Point Below
Watertable
Averaging Period for
Ground-water
Concentration at Receptor
Well
Symbol
Rm
6rw
Xrw
Yrw
IWLOC
LYCHK
z™
LZCHK
td
Units
m
degrees
m
m
-
m
yr
Section
6.2
6.3
6.4
6.5
6.5
6.5
6.6
6.6
6.7
Equation in EPACMTP TBD
4.21,4.22, 4.25 and 4.26
4.26a
4.21, 4.25a and 4.26b
4.22, 4.25b and 4.26C
Section 4.4.3.6
4.28 as constraint on yra
4.29
4.29 as constraint on z*ra
4.1 08 and 4.1 09
EPACMTP ultimately represents the receptor well location in a Cartesian
coordinate system whose X axis is oriented along the plume centerline for
convenience. However, the user can specify the areal receptor well location in either
cylindrical (Rm,Qm) or Cartesian (x^y^,) coordinates and the model will transform the
inputs accordingly. It's important to note that the specification of the receptor well
6-1
-------
Section 6.0 Receptor Well Parameters
depth, z^, is not dependent upon the chosen coordinate system. Figure 6.1
illustrates how the receptor well location is determined using cylindrical coordinates
(Figure 6.1 a) and Cartesian coordinates (Figure 6.1b).
EPACMTP provides two optional constraints to force receptor well locations
into the interior of the dissolved constituent plume; one constraint applies to the areal
location of the receptor well (LYCHK), and the other constrains the depth of the
receptor well (LZCHK). By default, the receptor well can be located anywhere
downgradient of the WMU (radial distance of up to about one mile, with the angle off-
center varying uniformly between 0 and 90 degrees) and anywhere within the
saturated thickness of the aquifer.
An additional option (IWLOC) provides a receptor well locating methodology
which addresses the tendency of WMUs with very large areas (e.g., LAUs) to bias
upward the Monte Carlo receptor well concentrations. This option is further described
in Section 6.5.
The final parameter discussed in this section is the averaging period for
ground water concentration at the receptor well. The averaging period is useful for
risk calculations which require an estimate of the exposure concentration over a
period of time, say 30 years.
6-2
-------
Section 6.0
Receptor Well Parameters
Plume
Centerline
(a)
Plume
Centerline
(b)
Region of Contaminant Plume
Figure 6.1 Schematic plan view showing procedure
for determining the downstream location of the
receptor well: (a) well location determined using radial
distance, R^, and angle off center 0^,; and (b) well
location generated uniformly within plume limit
6-3
-------
Section 6.0 Receptor Well Parameters
6.2 RADIAL DISTANCE TO RECEPTOR WELL (a...)
Definition
The radial distance to the receptor well (m) is measured from the
downgradient edge of the WMU to the nearest downgradient receptor well, as
depicted in Figure 6.1 a.
Parameter Value or Distribution of Values
As shown in Figures 6.1 a and 6.1 b, the default reference point or origin for
determining the receptor well location is midpoint of the downgradient edge of the
WMU. EPACMTP provides an alternative receptor well location methodology for
determining the reference point and it is controlled by the Monte Carlo control
parameter IWLOC. Setting the Monte Carlo control parameter IWLOC equal to zero
instructs EPACMTP to use the default reference point for determining the receptor
well location. If IWLOC is set equal to one, the alternate location method is used.
The alternate method has been included as a means to reduce the bias introduced by
WMUs with large areas. When Rm is always measured from the default reference
point, receptor well locations are more likely to lay inside the areal extent of the
dissolved constituent plume as the size of the WMU increases, biasing exposure
concentrations upward. To reduce the potential bias, the reference point in the
alternate scenario may be at any point somewhere between the corner and the center
of the downgradient edge of the WMU. Section 4.4.3.6 in the EPACMTP Technical
Background Document (U.S. EPA, 2003a) describes the alternate method in detail.
Rm may be specified by any appropriate distribution of values or by a constant value
to accommodate site-specific data or analysis-specific assumptions. Lacking site-
specific data, Rm is typically determined using the empirical distribution shown in
Table 6.2.
Data Sources
In a Monte Carlo simulation, the primary output from the model is the
exposure concentration at a receptor well located downgradient from the waste site.
Available studies and surveys suggest that on average, multiple downgradient wells
are present within the one-mile distance that is typically considered in regulatory
applications. To ensure a degree of protection in the modeling analysis, the model
computes the concentration at the nearest downgradient well. Information on the
downgradient distance to the nearest receptor well can be obtained from the U.S.
EPA OSW landfill survey (U.S. EPA, 1993). These data are presented as an
empirical distribution in Table 6.2. At most waste sites included in this survey, the
direction of ambient ground-water flow was not known exactly; therefore, it cannot be
ascertained whether the nearest receptor well is located directly along the plume
centerline. To reflect uncertainties and variations in the location of the receptor well
in relation to the direction of ambient ground-water flow, the modeled well is typically
allowed to be positioned at some varying distance from the plume centerline.
6-4
-------
Section 6.0
Receptor Well Parameters
Table 6.2 Cumulative Probability of Distance to Nearest Receptor Well for
Landfills (from EPA, 1993)
Cumulative Probability
0.0
0.03
0.04
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
0.98
1.00
Radial Distance (m)
0.6
13.7
19.8
45.7
103.6
152.4
182.9
243.8
304.8
304.8
365.7
396.2
426.7
457.2
609.6
762.0
804.6
868.6
914.4
1158.2
1219.1
1371.5
1523.9
1609.3
Use In EPACMTP
The first, and default, option of determining the well location involves
determining the Cartesian coordinates of the receptor well as a function of the radial
distance (Rw) from the center of the downgradient edge of the WMU and the angle off
of thje plume centerline (9m), as depicted in Figure 6.1 a. If Rm is specified, 9m must
also be specified. EPACMTP will derive xm and ym from the cylindrical coordinates
(see Section 6.4).
6.3 ANGLE OF WELL OFF OF PLUME CENTERLINE (9.J
Definition
The first, and default, option of determining the well location involves
determining the Cartesian coordinates of the receptor well as a function of the radial
distance (RJ from the center of the downgradient edge of the WMU and the angle
6-5
-------
Section 6.0 Receptor Well Parameters
off of the plume centerline (9m), as depicted in Figure 6.1 a. This angle, in
conjunction with Rm, defines the receptor well location in the cylindrical coordinates.
Parameter Value or Distribution of Values
Qm may be specified by any appropriate distribution of values or by a constant
value to accommodate site-specific data or analysis-specific assumptions. For
example, setting 9m to zero would constrain the receptor well location to the plume
centerline. Lacking site-specific data, to include all potential wells located
downstream of the waste units, the angle 9m is typically taken to be uniformly
distributed between 0°and 90°.
Data Sources
In a Monte Carlo simulation, the primary output from the model is the
exposure concentration at receptor well located downgradient from the waste site. If
site-specific data are unavailable, a default distribution of values may be used. Since
multiple downgradient wells are often present within the default one-mile distance, to
be protective, the modeled receptor well is taken to be the nearest downgradient well
based on an EPA OSW survey of municipal landfills (U.S. EPA, 1993). However, at
most waste sites included in this survey, the direction of ambient ground-water flow
was not known exactly; therefore, it cannot be ascertained whether the nearest
receptor well is located directly along the plume centerline. To reflect uncertainties
and variations in the location of the receptor well in relation to the direction of ambient
ground-water flow, the modeled well is typically allowed to be positioned at a variable
y-distance from the plume centerline.
Thus, to include all hypothetical receptor wells located downstream of the
waste units, the angle 9m is, by default, assumed to be uniformly distributed between
0° and 90°.
Use In EPACMTP
The first, and default, option of determining the well location involves
determining the Cartesian coordinates of the receptor well as a function of the radial
distance (Rm) from the center of the downgradient edge of the WMU and the angle
off of the plume centerline (9m), as depicted in Figure 6.1 a. If 9m is specified, Rm
must also be specified. EPACMTP will derive xm and ym from the cylindrical
coordinates (see Section 6.4).
6.4 DOWNGRADIENT DISTANCE TO RECEPTOR WELL
Definition
The downgradient distance to the receptor well (m) is the distance to the well,
as measured from the center of downgradient edge of the WMU along the long-term
average ground-water flow path (plume centerline), as depicted in Figure 6.1 b.
6-6
-------
Section 6.0 Receptor Well Parameters
Parameter Value or Distribution of Values
The first, and default, option of determining the well location involves
determining the Cartesian coordinates of the receptor well as a function of the radial
distance, Rm, from the center of the downgradient edge of the waste unit, and the
angle off-center, 9m, as depicted in Figure 6.1 a. xm is derived using the following
equation:
where
xm = X Cartesian coordinate of the receptor well (m)
Rm = radial distance between waste unit and well (m),
9m = angle measured counter-clockwise from the plume centerline
(degrees)
The second method incorporated in EPACMTP to determine the receptor well
location is to generate a well position directly from the Cartesian coordinates, xm and
ym. In this case, the Cartesian parameters are specified in the EPACMTP input file,
and the cylindrical parameters are ignored (typically these inputs are omitted from the
input file). If site-specific data on well location(s) are available, then these data can
be used to specify a constant value or an empirical or statistical distribution of values
for xm and ym.
Alternatively, xm and ym can also be used to specify the well location such that
the well is located uniformly between the plume centerline and the areal plume
boundary, for any given x-distance (Figure 6.1b). This option is described further in
Section 6.5 (Well Distance From Plume Centerline (yw))
To reflect uncertainties and variations in the location of the receptor well in
relation to the direction of ambient ground-water flow, the modeled well is allowed to
be positioned at some varying distance from the plume centerline.
Data Sources
Lacking site-specific data, information on the downgradient distance to the
nearest receptor well can be obtained from the U.S. EPA OSW landfill survey (U.S.
EPA, 1993). These data are presented as an empirical distribution in Table 6.2.
Use In EPACMTP
The downgradient distance to the receptor well (xm) is used to represent the
location at which the potential exposure concentration to the ground water is
measured.
6-7
-------
Section 6.0 Receptor Well Parameters
6.5 WELL DISTANCE FROM PLUME CENTERLINE (v,...)
Definition
The well distance from the plume centerline (m) is the distance from the
plume centerline to the well, measured perpendicular to the plume centerline, as
depicted in Figure 6.1b.
Parameter Value or Distribution of Values
The first, and default, option of determining the well location involves
determining the Cartesian coordinates of the receptor well as a function of the radial
distance, Rm, from the center of the downgradient edge of the waste unit, and the
angle off-center, 9m, as depicted in Figure 6.1 a. The parameter ym is derived using
the following equation:
X™ = Rrw sin (9 J (6.2)
where
ym = Y Cartesian coordinate of the receptor well (m)
Rm = radial distance between waste unit and well (m),
9m = angle measured counter-clockwise from the plume centerline
(degrees)
The second method incorporated in EPACMTP to determine the receptor well
location is to generate a well position directly from the Cartesian coordinates, xm and
ym. In this case, the Cartesian parameters are specified in the EPACMTP input file,
and the cylindrical parameters are ignored (typically these inputs are omitted from the
input file). If site-specific data on well location(s) are available, then these data can
be used to specify a constant value or an empirical or statistical distribution of values
for xm and ym.
Alternatively, xm and ym can also be used to estimate the well location such
that the well is located uniformly between the plume centerline and the areal plume
boundary, for any given x-distance (Figure 6.1b). With this option, xm is generated
from the empirical distribution in Table 6.2. Next, the ym of the well is generated from
a uniform distribution with a minimum value of zero, and a maximum value given by
the following equation:
ym< yD+ 3[2ar(xw + xj]1/2 (6.3)
6-8
-------
Section 6.0 Receptor Well Parameters
where
yD = width of the waste unit in the y-direction (m)
xm = length of the waste unit in the x-direction (m)
ay = horizontal transverse dispersivity (m)
xw = length of the WMU in the x-direction (parallel to ground-water
flow) (m)
This approximation for the lateral extent of the contaminant plume is based on
the assumption that plume spreading in the horizontal-transverse direction is caused
by dispersive mixing, which results in a Gaussian profile of the plume cross-section.
Use of Equation 6-3 implies that 99.7% of the contaminant mass will be present
inside the transverse plume limit.
To select this option, the Monte Carlo control parameter LYCHK should be set
to TRUE, the xm should be specified as an empirical parameter with values as given
in Table 6.2, and the ym should be specified as a uniform distribution with limits of
zero and one.
Data Sources
No default data sources are available for ym. Information on the downstream
distance to the nearest receptor well can be obtained from the U.S. EPA OSW landfill
survey (U.S. EPA, 1993). These data are presented as an empirical distribution in
Table 6.2. At most waste sites included in this survey, the direction of ambient
ground-water flow was not known exactly; therefore, it cannot be ascertained whether
the nearest receptor well is located directly along the plume centerline. To reflect
uncertainties and variations in the location of the receptor well in relation to the
direction of ambient ground-water flow, the modeled well is typically allowed to be
positioned at some varying distance from the plume centerline if site-specific data are
not available.
Use In EPACMTP
Along with the term xm (downgradient distance to the receptor well), the ym
parameter is used to define the location of a receptor well. The ym parameter
represents the perpendicular distance from the plume centerline at which the
potential exposure to the ground water is measured. Setting ym to zero constrains
the receptor well location to the plume centerline.
6-9
-------
Section 6.0 Receptor Well Parameters
6.6 DEPTH OF INTAKE POINT BELOW WATERTABLE (z'.,..)
Definition
The depth of the intake point below the water table (m) is the depth at which
the model calculates the resulting ground-water concentration. Unlike most wells in
the real world that have a screened interval of several feet or more, the simulated
receptor well in EPACMTP has an intake that is a single point in space, as if the well
consisted of a solid casing that was open at the bottom. In this case, the intake point
would be the same as the depth of the well (or z*m). Note that this depth is measured
downwards from the watertable, not from the ground surface.
Parameter Value or Distribution of Values
Three options are available for specifying the vertical position of the well
intake point below the watertable: uniform distribution, constrained distribution, or
constant value.
The first, and default, option is to model the vertical position of the well intake
point as being uniformly distributed between the water table (z=0) and the saturated
aquifer thickness. This option is selected by specifying the z-position as a uniform
distribution with lower and upper limits of 0.0 and 1.0. EPACMTP will multiply this
uniformly generated value by the saturated zone thickness to yield the actual receptor
well depth below the water table for each Monte Carlo iteration. When the generated
value for the vertical position of the receptor well intake point exceeds the saturated
thickness of the aquifer (a physically impossible condition), a new well position is
generated to ensure that the well depth is always less than the saturated thickness.
Conversely, the well depth cannot be less than the minimum depth to the saturated
zone.
Alternatively, the vertical position of the observation well can be optionally
constrained to lie within the approximate vertical penetration depth of the contaminant
plume emanating from the waste unit. This is achieved through the Monte Carlo
input variable LZCHK. If LZCHK is set to FALSE, the constraint is not enforced. If
LZCHK is set to TRUE, the z*m is constrained to lie within the approximate vertical
extent of the contaminant plume as defined by:
Q4F
2.5 i^—=1- 8 +
Q3F+ Q4F
= z' (6.4)
rw max
6-10
-------
Section 6.0 Receptor Well Parameters
where
z*mmax = Maximum allowable z*-coordinate of the receptor well; that is,
the approximate vertical penetration depth of the dissolved
constituent plume (m)
QF1-QF4= Components of the ground-water flow field (m2/yr), see U.S.
EPA (2003a), Section 4, Figure 4.7
B = Saturated zone thickness (m)
xw = Length of source in downstream direction (m)
xm = Horizontal distance between source and receptor well (m)
aL = Longitudinal dispersivity (m)
av = Vertical dispersivity (m)
-------
Section 6.0 Receptor Well Parameters
Parameter Value or Distribution of Values
Usual values of this parameter are 70 years (lifetime exposure), 30 years
(high-end residence time), 9 years (average residence time), or 7 years (child
exposure) (U.S. EPA, 2000). Although this value is often entered as a constant
value, it can also be specified as a statistical or empirical distribution of values.
By default, the exposure period for averaging the receptor well concentration
is not provided; in other words, the model only calculates the peak receptor well
concentration. The peak receptor well concentration is sometimes used for
calculating the resulting health risk for non-carcinogenic constituents or for
comparisons to the maximum contaminant levels (MCLs) (The National Drinking
Water Standards at 40 CFR 141).
Data Sources
The choice of the averaging period should be consistent with the types of
risks to be calculated using the exposure results generated by EPACMTP. The
EPA's Exposure Factors Handbook (U.S. EPA 1997a-c) contains constituent-specific
data on exposure durations for various exposure scenarios.
Use In EPACMTP
EPACMTP always generates a steady state receptor well concentration and a
peak concentration. Steady state concentrations correspond to an infinite source
analysis; peak concentrations represent the maximum concentration at the well under
the finite source scenario. Average concentrations for defined exposure periods are
optional results for finite source simulations. If average concentrations are required,
up to 10 averaging periods can be specified. If the period of averaging is longer than
the period of time for which concentrations are observed at the receptor well, the
result will be the average of the available observations.
6-12
-------
Section 7.0 References
7.0 REFERENCES
API, 1989. Hydrogeologic Database for Groundwater Modeling. API Publication No.
4476, American Petroleum Institute.
Bear, J., 1979. Hydraulics of Groundwater. McGraw Hill, New York.
Bonaparte, Ft., J. P. Giroud, and B.A. Cross, 1989. Rates of leakage through landfill
liners. Geosynthetics 1989 Conference, San Diego, California.
Carsel, R.F., and R.S. Parrish, 1988. Developing joint probability distributions of soil
water retention characteristics. Water Resour. Res. Vol 24, No. 5:755-769.
Carsel, R.F., R.S. Parrish, R.L. Jones, J.L. Hansen, and R.L. Lamb, 1988.
Characterizing the Uncertainty of Pesticide Leaching in Agricultural Soils.
Journal of Contaminant Hydrology Vol 2: 111-124.
CRC, 1981. Handbook of Chemistry and Physics. 62nd edition. Chemical Rubber
Company, Cleveland, OH 44128.
Davis, S.N., 1969. Porosity and permeability of natural materials. In: Flow Through
Porous Media, R.J.M. de Wiest, Editor, Academic Press, NY. 10007
Enfield, C.G., et al., 1982. Approximating pollutant transport to groundwater.
GroundWater, 10(6) :711-722.
EPRI, 1985. A review of field scale physical solute transport processes in saturated
and unsaturated porous media. Electric Power Res. Inst., Palo Alto, CA.
Freeze, R.A., and J. Cherry, 1979. Groundwater. Prentice-Hall, Englewood Cliffs,
NJ. 08837
Gelhar, L.W., C. Welty, K.R. Rehfeldt, 1992. A critical review of data on field-scale
dispersion in aquifers. Water Resour. Res., 28(7), 1955-1974.
Gintautas, P.A., K.A. Huyck, S.R. Daniel, and D.L. Macalady, 1993. Metal-Organic
Interactions in Subtitle D Landfill Leachates and Associated Groundwaters, in
Metals in Groundwaters, H.E. Allen, E.M. Perdue, and D.S. Brown, eds.
Lewis Publishers, Ann Arbor, Ml. 60604
Heath, R.C., 1984. State Summaries of Groundwater Resources. United States
Geological Survey Water-Supply Paper 2275.
HydroGeoLogic, Inc., 1992. A Revised Procedure for Determining Dispersivity
Values for Use in EPA Fate and Transport Models. HydroGeoLogic, Inc.,
Herndon,VA. 20170
7-1
-------
Section 7.0 References
Karickhoff, S.W., 1985. Sorption protocol for evaluation of OSW chemicals. U.S.
EPA, Athens Environmental Research laboratory, Athens, GA. 30605
Kollig, H.P., 1993, Environmental Fate Constants for Organic Chemicals Under
Consideration for EPA's Hazardous Waste Identification Projects, Report No.
EPA/600/R-93/132).
Loux, NT., C.R. Chafin, and S.M Hassan, 1990. Statistics of Aquifer Material
Properties and Empirical pH-dependent Partitioning Relationships for As(lll),
As(V), BA(II), Cd(ll), Cr(VI), Cu(ll), Hg(ll), Ni(ll), Pb(ll), Sb(V), Se(IV), Tl(l),
and Zn(ll). U.S. Environmental Protection Agency, Athens, GA. 30605
Mathur, S. S., 1995. Development of a Database for Ion Sorption on Goethite Using
Surface Complexation Modeling. Master's Thesis, Department of Civil and
Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA.
15230
McWorter, D.B., and O.K. Sunada, 1977. Groundwater Hydrology and Hydraulics,
Water Resources Publications, Fort Collins, CO.
Newell, C. J., L. P. Hopkins, and P. B. Bedient, 1990. A hydrogeologic data base for
groundwater modeling. Ground Water 28(5):703-714.
Schanz, Rob, and Salhotra, Atul, 1992. Subtitle D Landfill Characteristics. Center
for Modeling and Risk Assessment, Woodward-Clyde Consultants, Oakland,
California.
Schroeder, P.R., T.S., Dozier, P.A. Zappi, B.M. McEnroe, J. W. Sjostrom, and R.L.
Peton, 1994. The hydrologic evaluation of landfill performance model
(HELP): Engineering Documentation for Version 3. EPA/600/R-94/1686.
United States Environmental Protection Agency, Cincinnati, OH.
Shea, J.H., 1974. Deficiencies of elastic particles of certain sizes. Journal of
Sedimentary Petrology, 44: 985-1003.
TetraTech, Inc., 2001. Characterization of infiltration rate data to support
groundwater modeling efforts (Draft). Prepared for the U.S. Environmental
Protection Agency, Office of Solid Waste, Contract No. 68-W6-0061, May,
2001.
Todd, O.K., 1980. Groundwater Hydrology (2nd edition), John Wiley & Sons, 535
pages.
U.S. EPA, 1985. DRASTIC: A Standardized System for Evaluating Ground Water
Pollution Potential Using Hydrogeologic Settings. EPA/600-2-85/018,
Washington, DC. 20460
7-2
-------
Section 7.0 References
U.S. EPA, 1986. Industrial Subtitle D Facility Study (Telephone Survey), U.S.
Environmental Protection Agency, October 20, 1986.
U.S. EPA, 1990. Background Document for EPA's Composite Model for Landfills
(EPACML). U.S. EPA, Office of Solid Waste, Washington, D.C., 20460.
U.S. EPA, 1993. Parameter values for the EPA's composite module for landfills
(EPACML) used in developing nationwide regulations: Toxicity Characteristic
Rule, Office of Solid Waste, Washington, D.C., 20460.
U.S. EPA. 1996. EPA's Composite Model for Leachate Migration with
Transformation Products, Background Document for EPACMTP: Metals
Transport in the Subsurface, Volume 1: Methodology. Office of Solid Waste.
U.S. Environmental Protection Agency, Washington, D.C. 20460.
U.S. EPA, 1997a. Exposure Factors Handbook, Volume I, General Factors.
EPA/600/P-95/002Fa. Office of Research and Development, Washington,
DC. 20460
U.S. EPA, 1997b. Exposure Factors Handbook, Volume II, Food Ingestion Factors.
EPA/600/P-95/002Fb. Office of Research and Development, Washington,
DC. 20460
U.S. EPA, 1997c. Exposure Factors Handbook, Volume III, Activity Factors.
EPA/600/P-95/002Fc. Office of Research and Development, Washington,
DC. 20460
U. S. EPA. 1997d. Analysis of EPA's Industrial Subtitle D Databases used in
Groundwater Pathway Analysis of the Hazardous Waste Identification Rule
(HWIR). Office of Solid Waste, Washington, DC. 20460
U.S. EPA. 1999. EPA's Composite Model for Leachate Migration with
Transformation Products, Background Document for EPACMTP: Metals
Transport in the Subsurface, Volume 2: Sorption Isotherms. Office of Solid
Waste. U.S. Environmental Protection Agency, Washington, D.C. 20460.
U.S. EPA, 2000. Risk Assessment for the Listing Determination for Inorganic
Chemical Manufacturing Wastes: Background Document. U.S.
Environmental Protection Agency, Office of Solid Waste, Washington, DC
20460.
U.S. EPA, 2001 a. Industrial Surface Impoundments in the United States. U.S. EPA
Office of Solid Waste, Washington, DC 20460. USEPA 530-R-01-005.
U.S. EPA, 2001 b. Water 9 Model. Office of Air Quality Planning and Standards,
Research Triangle Park, NC. 27711
http://www.epa.gov/ttn/chief/software/water/index.html.
7-3
-------
Section 7.0 References
U.S. EPA, 2003a. EPACMTP Technical Background Document. Office of Solid
Waste, Washington, DC. 20460
U.S. EPA, 2003b. IWEM User's Guide. Office of Solid Waste, Washington, DC.
20460 USEPA 530-R-02-013.
U.S. EPA, 2003c. IWEM Technical Background Document. Office of Solid Waste,
Washington, DC. 20460 USEPA530-R-02-012.
van Genuchten, M.Th., 1980. A closed-form equation for predicting the hydraulic
conductivity of unsaturated soils, Soil Sci. Soc. J., v. 44, pp. 892-898.
Verschueren, K., 1983. Handbook of Environmental Data on Organic Chemicals.
Van Nostrand Reinhold Co., New York. 10017
White, D.E., J.D. Hem, and G.A. Waring, 1963. Chemical Composition of
Subsurface Waters, Data of Geochemistry. U.S. Geological Survey
Professional Paper 440-F, U.S. Government Printing Office, Washington,
DC.
Wolfe, N.L., 1985. Screening of hydrolytic reactivity of OSW chemicals. US EPA
Athens Environmental Research Laboratory, Athens, GA. 30605
7-4
-------
APPENDIX A
DETERMINATION OF INFILTRATION AND RECHARGE RATES
-------
This page intentionally left blank.
-------
TABLE OF CONTENTS
Page
A.1 INFILTRATION AND RECHARGE RATES A-1
A.1.1 USING THE HELP MODEL TO DEVELOP RECHARGE AND
INFILTRATION RATES A-2
A.1.2 INFILTRATION RATES FOR UNLINED UNITS A-11
A.1.3 SINGLE-LINED WASTE UNITS A-14
A.1.4 INFILTRATION RATES FOR COMPOSITE-LINED UNITS .... A-16
A.1.5 DETERMINATION OF RECHARGE RATES A-33
A.2 REFERENCES A-34
A-i
-------
LIST OF FIGURES
Page
Figure A.1 Locations of HELP Climate Stations A-7
A-ii
-------
LIST OF TABLES
Page
Table A.1 Methodology Used to Compute Infiltration for LFs A-3
Table A.2 Methodology Used to Compute Infiltration for Sis A-4
Table A.3 Methodology Used to Compute Infiltration for WPs A-5
Table A.4 Methodology Used to Compute Infiltration for LAUs A-6
Table A.5 Grouping of Climate Stations by Average Annual Precipitation
and Pan Evaporation (ABB, 1995) A-9
Table A.6 Hydraulic Parameters for the Modeled Soils A-11
Table A.7 Moisture Retention Parameters for the Modeled WP Materials . A-13
Table A.8 Cumulative Frequency Distribution of Infiltration Rate for
Composite-Lined LFs and WPs A-17
Table A.9 Cumulative Frequency Distribution of Leak Density for
Composite-Lined Sis A-19
Table A.10 Cumulative Frequency Distribution of Infiltration Rate for
Composite-Lined Sis A-19
Table A.11 HELP-derived Landfill Infiltration Rates A-19
Table A.12 HELP-derived Waste Pile Infiltration Rates A-23
Table A.13 HELP-derived Land Application Unit Infiltration Rates A-27
Table A.14 HELP-derived Regional Recharge Rates A-30
A-iii
-------
This page intentionally left blank.
-------
APPENDIX A
DETERMINATION OF INFILTRATION AND RECHARGE RATES
A.1 INFILTRATION AND RECHARGE RATES
EPACMTP requires the input of the rate of downward percolation of water
and leachate through the unsaturated zone to the water table. The model
distinguishes between two types of percolation as infiltration and recharge:
• Infiltration (WMU leakage rate) is defined as water percolating
through the WMU - including a liner if present - to the underlying soil.
• Recharge is water percolating through the soil to the aquifer outside
the WMU.
Infiltration is one of the key parameters affecting the leaching of waste
constituents into the subsurface. For a given leachate concentration, the mass of
constituents leached is directly proportional to the infiltration rate. In EPACMTP,
using a different default liner scenario changes the modeled infiltration rate; more
protective liner designs reduce leaching by decreasing the rate of infiltration.
In contrast, recharge introduces pristine water into the aquifer. Increasing
recharge therefore tends to result in a greater degree of plume dilution and lower
constituent concentrations. High recharge rates may also affect the extent of
ground-water mounding and ground-water velocity. The recharge rate is
independent of the type and design of the WMU; rather it is a function of the climatic
and hydrogeological conditions at the WMU location, such as precipitation,
evapotranspiration, surface run-off, and regional soil type.
In developing the EPACMTP model and the accompanying databases, the
U.S. EPA used several methodologies to estimate infiltration and recharge. We
used the HELP model (Schroeder et al, 1994) to compute recharge rates for all
units, as well as infiltration rates for LAUs, and for LFs and WPs with no-liner and
single-liner designs. For LFs and WPs, composite liner infiltration rates were
compiled from leak-detection-system flow rates reported for actual composite-lined
waste units (TetraTech, 2001).
For unlined and single-lined Sis, infiltration through the bottom of the
impoundment is calculated internally by EPACMTP, as described in Section 4.3.4 of
this document. For composite-lined Sis, we used the Bonaparte (1989) equation to
calculate the infiltration rate assuming circular (pin-hole) leaks with a uniform leak
size of 6 mm2, and using the distribution of leak densities (number of leaks per
hectare) assembled from the survey of composite-lined units (TetraTech, 2001).
Tables A.1 through A.4 summarize the liner assumptions and infiltration rate
calculations for LFs, WPs, Sis, and LAUs. The remainder of this appendix provides
background on how we used the HELP model in conjunction with data from climate
stations across the United States to develop nationwide recharge and infiltration rate
A-1
-------
Appendix A Determination of Infiltration and Recharge Rates
distributions and provides a detailed discussion of how we developed infiltration
rates for different default liner designs for each type of WMU.
A.1.1 USING THE HELP MODEL TO DEVELOP RECHARGE AND
INFILTRATION RATES
The HELP model is a quasi-two-dimensional hydrologic model for computing
water balances of LFs, cover systems, and other solid waste management facilities.
The primary purpose of the model is to assist in the comparison of design
alternatives. The HELP model uses weather, soil and design data to compute a
water balance for LF systems accounting for the effects of surface storage,
snowmelt, runoff, infiltration, evapotranspiration, vegetative growth, soil moisture
storage, lateral subsurface drainage, leachate recirculation, unsaturated vertical
drainage, and leakage through soil, geomembrane or composite liners. The HELP
model can simulate LF systems consisting of various combinations of vegetation,
cover soils, waste cells, lateral drain layers, low permeability barrier soils, and
synthetic geomembrane liners.
HELP Versions 3.03 and 3.07 (which include WMU- and liner-specific
distributions of infiltration rates) were used to construct the EPACMTP site data files.
We started with an existing database of no-liner infiltration rates for LFs, WPs and
LAUs. Also existing were recharge rates for 97 climate stations in the lower 48
contiguous United States (ABB, 1995), that are representative of 25 specific climatic
regions (developed with HELP version 3.03). We then added five climate stations
(located in Alaska, Hawaii, and Puerto Rico) to ensure coverage throughout all of the
United States. Figure A.1 shows the locations of the 102 climate stations.
The current version of HELP (version 3.07) was used for the modeling of the
additional climate stations for the no-liner scenario. We compared the results of
Version 3.07 against Version 3.03 and found that the differences in calculated
infiltration rates were insignificant. We also used this comparison to verify a number
of counter-intuitive infiltration rates that were generated with HELP Version 3.03.
We had observed that for some climate stations located in areas of the country with
low precipitation rates, the net infiltration for unlined LFs did not always correlate
with the relative permeability of the LF cover. We found some cases in which a less
permeable cover resulted in a higher modeled infiltration rate as compared to a more
permeable cover. Examples can be seen in the detailed listing of infiltration data
that are presented in Tables A.11 to A. 14. For instance, Table A.11 shows that for a
number of climate stations, including Albuquerque, Denver, and Las Vegas, the
modeled infiltration rate for LFs with a silty clay loam (SCL) cover is higher than the
values corresponding to silt loam (SLT) and sandy loam (SNL) soil covers. We
determined that in all these cases, the HELP modeling results for unlined LFs were
correct and could be explained in terms of other water balance components,
including surface run-off and evapotranspiration.
A-2
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.1 Methodology Used to Compute Infiltration for LFs
Method
Final Cover
Liner
Design
EPACMTP
Infiltration
Rate
No Liner
HELP model
simulations to compute
an empirical distribution
of infiltration rates for a
2 ft. thick cover of three
native soil cover types
using nationwide
coverage of climate
stations. Soil-type
specific infiltration rates
for a specific site are
assigned by using the
infiltration rates for
respective soil types at
the nearest climate
station.
Monte Carlo selection
from distribution of soil
cover types. 2 ft thick
native soil (1 of 3 soil
types: silty clay loam,
silt loam, and sandy
loam) with a range of
mean hydraulic
conductivities (4.2x10"5
cm/sto7.2x10"4cm/s).
No liner
Monte Carlo selection
from HELP generated
location- specific
values.
Single Liner
HELP model
simulations to compute
an empirical
distribution of infiltration
rates through a single
clay liner using
nationwide coverage of
climate stations.
Infiltration rates for a
specific site were
obtained by using the
infiltration rate for the
nearest climate station.
3 ft thick clay cover with
a hydraulic conductivity
of 1xlO"7 cm/sec and a
1 0 ft thick waste layer.
On top of the cover, a 1
ft layer of loam to
support vegetation and
drainage and a 1 ft
percolation layer.
3 ft thick clay liner with
a hydraulic conductivity
of 1x10"7 cm/sec. No
leachate collection
system. Assumes
constant infiltration rate
(assumes no increase
in hydraulic conductivity
of liner) over modeling
period.
Monte Carlo selection
from HELP generated
location-specific
values.
Composite Liner
Compiled from
literature sources
(TetraTech, 2001) for
composite liners
No cover modeled; the
composite liner is the
limiting factor in
determining infiltration
60 mil HOPE layer with
either an underlying
geosynthetic clay liner
with maximum
hydraulic conductivity of
5x10"9 cm/sec, or a 3-
foot compacted clay
liner with maximum
hydraulic conductivity of
1x10"7 cm/sec.
Assumes same
infiltration rate (i.e., no
increase in hydraulic
conductivity of liner)
over modeling period.
Monte Carlo selection
from distribution of leak
detection system flow
rates.
A-3
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.2 Methodology Used to Compute Infiltration for Sis
Method
Ponding
Depth
Liner
Design
EPACMTP
Infiltration
Rate
No Liner
EPACMTP SI module
for infiltration through
consolidated sludge
and native soil layers
with a unit-specific
ponding depth from
EPA's SI Study (EPA,
2001).
Unit-specific based on
EPA's SI study.
None. However,
barrier to infiltration is
provided by
layer of consolidated
sludge at the bottom of
the impoundment, and
a layer of clogged
native soil below the
consolidated sludge.
The sludge thickness is
assumed to be
constant over the
modeling period. The
hydraulic conductivity of
the consolidated sludge
is between 1.3x10"7 and
1.8x10"7 cm/sec. The
hydraulic conductivity of
the clogged native
material is assumed to
be 0.1 of the unaffected
native material in the
vadose zone.
Calculated by
EPACMTP based on
Monte Carlo selection
of unit-specific ponding
depth.
Single Liner
EPACMTP module for
infiltration through a
layer of consolidated
sludge and a single
clay liner with unit-
specific ponding depth
from EPA's SI study.
Unit-specific based on
EPA's SI study.
3 ft thick clay liner with
a hydraulic conductivity
of 1x10"7 cm/sec. No
leachate collection
system. Assumes no
increase in hydraulic
conductivity of liner
over modeling period.
Additional barrier is
provided by a layer of
consolidated sludge at
the bottom of the
impoundment, see no-
liner column.
Calculated based on
Monte Carlo selection
of unit-specific ponding
depth
Composite Liner
Bonaparte equation
(1989) for pin-hole
leaks using distribution
of leak densities for
units installed with
formal CQA programs
Unit-specific based on
EPA's SI study.
60 mil HOPE layer with
either an underlying
geosynthetic clay liner
with maximum
hydraulic conductivity of
5x10"9 cm/sec, or a 3-
foot compacted clay
liner with maximum
hydraulic conductivity of
1x10"7 cm/sec.
Assumptions: 1)
constant infiltration rate
(i.e., no increase in
hydraulic conductivity of
liner) over modeling
period;
2) geomembrane liner
is limiting factor that
determines infiltration
rate.
Calculated based on
Monte Carlo selection
of unit-specific ponding
depth and distribution
of leak densities
A-4
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.3 Methodology Used to Compute Infiltration for WPs
Method
Cover
Liner
Design
EPACMTP
Infiltration
Rate
No Liner
HELP model
simulations to compute
distribution of infiltration
rates for a 1 0 ft. thick
layer of waste, using
three waste
permeabilities (copper
slag, coal bottom ash,
coal fly ash) and
nationwide coverage of
climate stations.
Waste-type-specific
infiltration rates for a
specific site are
obtained by using the
infiltration rates for
respective waste types
at the nearest climate
station.
None
No liner.
Monte Carlo selection
from HELP generated
location-specific
values.
Single Liner
HELP model
simulations to compute
distribution of infiltration
rates through 10 ft.
waste layer using three
waste permeabilities
and nationwide
coverage of climate
stations. Infiltration
rates for a specific site
were obtained by using
the infiltration rate for
the nearest climate
station.
None
3 ft thick clay liner with
a hydraulic conductivity
of 1x10"7 cm/sec, no
leachate collection
system, and a 10 ft
thick waste layer.
Assumes no increase
in hydraulic conductivity
of liner over unit's
operational life.
Monte Carlo selection
from HELP generated
location- specific
values.
Composite Liner
Compiled from
literature sources
(TetraTech, 2001) for
composite liners
None
60 mil HOPE layer with
either an underlying
geosynthetic clay liner
with maximum
hydraulic conductivity of
5x10"9 cm/sec, or a 3-
foot compacted clay
liner with maximum
hydraulic conductivity of
1x10"7 cm/sec.
1) same infiltration
rate (i.e., no increase in
hydraulic conductivity of
liner) over unit's
operational life;
2) geomembrane is
limiting factor in
determining infiltration
rate.
Monte Carlo selection
from distribution of leak
detection system flow
rates
A-5
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.4 Methodology Used to Compute Infiltration for LAUs
Method
Liner
Design
EPACMTP
Infiltration
Rate
No Liner
HELP model
simulations to compute
an empirical
distribution of
infiltration rates for a
0.5 ft thick sludge
layer, underlain by a 3
ft layer of three types
of native soil using
nationwide coverage of
climate stations. Soil-
type specific infiltration
rates for a specific site
are assigned by using
the infiltration rates for
respective soil types at
the nearest climate
station.
No liner
Monte Carlo selection
from HELP generated
location specific
values.
Single Liner
N/A
N/A
N/A
Composite Liner
N/A
N/A
N/A
A-6
-------
Aaribou
Boston
•Worcester
Rovidsnce
•hWord
Na/vhfewsn
Bidgeport
GfentnalRark
Aaska
RjertoHoo
§
CD
CD
9?
1'
I
o
—K
o'
Q.
33
CD
c
Figure A.1 Locations of HELP Climate Stations
-------
Appendix A Determination of Infiltration and Recharge Rates
The first 97 climate stations were grouped into 25 climate regions based on
ranges of average annual precipitation and pan evaporation, as shown in Table A.5.
For each modeled climate station, HELP provides a database of five years of
climatic data. We used this climatic data, along with data on the regional soil type
and WMU design characteristics, to calculate a water balance for each applicable
default liner design as a function of the amount of precipitation that reaches the top
surface of the unit, minus the amount of runoff and evapotranspiration. The HELP
model then computed the net amount of water that infiltrates through the surface,
waste, and liner layers, based on the initial moisture content and the hydraulic
conductivity of each layer.
In addition to climate factors and liner designs, the infiltration rates calculated
by HELP are affected by LF cover design, permeability of the waste material in WP,
and LAU soil type. For every climate station and WMU type (LF, WP and LAU), we
calculated three HELP infiltration rates. For a selected WMU type and liner design,
the regional site-based modeling process selects randomly from among the HELP-
derived infiltration and recharge data, to capture both the nationwide variation in
climate conditions, as well as variations in LF soil cover type, WP waste
permeability, and LAU soil type.
The factors related to soil type that affect the HELP-generated infiltration and
recharge rates are the permeability of the soil used in the LF cover, and - in the
case of recharge or for LAUs - the permeability of the soil type in the vicinity of the
WMU. We used the same set of soil types (sandy loam, silty loam, and silty clay
loam) and soil properties in the infiltration and recharge rate calculations as we did in
the unsaturated zone fate and transport simulations (see Table 5.4 in Section 5.2.4).
In the case of uncovered WPs we found that the infiltration rates predicted by
the HELP model are sensitive to the permeability of the waste material itself. Based
on these results, we simulated WP infiltration rates for three different WP materials:
relatively high permeability, moderate permeability, and relatively low permeability.
When these rates are used in the EPACMTP modeling, each waste type has an
equal likelihood of occurrence.
A-8
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.5 Grouping of Climate Stations by Average Annual Precipitation
and Pan Evaporation (ABB, 1995)
City
Boise
Fresno
Bismarck
Denver
Grand
Junction
Pocatello
Glasgow
Pullman
Yakima
Cheyenne
Lander
Rapid City
Los Angeles
Sacramento
San Diego
Santa Maria
Ely
Cedar City
Albuquerque
Las Vegas
Phoenix
Tucson
El Paso
Medford
Great Falls
Salt Lake City
Grand Island
State
ID
CA
ND
CO
CO
ID
MT
WA
WA
WY
WY
SD
CA
CA
CA
CA
NV
UT
NM
NV
AZ
AZ
TX
OR
MT
UT
NE
Climate Region
Precipitation
(in/yr)
<16
< 16
<16
<16
< 16
16-24
16-24
Evaporation
(in/yr)
<30
30-40
40-50
50-60
>60
30-40
40-50
City
Columbia
Put-in-Bay
Madison
Columbus
Cleveland
Des Moines
E. St. Louis
Topeka
Tampa
San Antonio
Portland
Hartford
Syracuse
Worchester
Augusta
Providence
Nashua
Ithaca
Boston
Schenectady
NY City
Lynchburg
Philadelphia
Seabrook
Indianapolis
Cincinnati
Bridgeport
Jacksonville
Orlando
State
MO
OH
Wl
OH
OH
IA
IL
KS
FL
TX
ME
CT
NY
MA
ME
Rl
NH
NY
MA
NY
NY
VA
PA
NJ
IN
OH
CT
FL
FL
Climate Region
Precipitation
(in/yr)
32-40
32-40
32-40
40-48
40-48
40-48
Evaporation
(in/yr)
30-40
40-50
50-60
<30
30-40
40-50
A-9
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.5 Grouping of Climate Stations by Average Annual Precipitation
and Pan Evaporation (ABB, 1995) (continued)
City
Flagstaff
Dodge City
Midland
St. Cloud
E. Lansing
North Omaha
Dallas
Tulsa
Brownsville
Oklahoma City
Bangor
Concord
Pittsburgh
Portland
Caribou
Chicago
Burlington
Rutland
Seattle
Montpelier
Sault St. Marie
State
AZ
KS
TX
MN
Ml
NE
TX
OK
TX
OK
ME
NH
PA
OR
ME
IL
VT
VT
WA
VT
Ml
Climate Region
Precipitation
(in/yr)
16-24
16-24
24-32
24-32
24-32
24-32
24-32
32-40
Evaporation
(in/yr)
50-60
>60
<30
30-40
40-50
50-60
>60
<30
City
Greensboro
Watkinsville
Norfolk
Shreveport
Astoria
New Haven
Plainfield
Nashville
Knoxville
Central Park
Lexington
Edison
Atlanta
Little Rock
Tallahassee
New Orleans
Charleston
W. Palm
Beach
Lake Charles
Miami
State
NC
GA
VA
LA
OR
CT
MA
TN
TN
NY
KY
NJ
GA
AK
FL
LA
SC
FL
LA
FL
Climate Region
Precipitation
(in/yr)
>48
>48
>48
>48
Evaporation
(in/yr)
<30
30-40
40-50
50-60
A-10
-------
Appendix A
Determination of Infiltration and Recharge Rates
A.1.2 INFILTRATION RATES FOR UNLINED UNITS
Landfill
We used the HELP model to simulate infiltration through closed LFs for each
of the 102 climate station locations shown in Figure A.1. A 2-foot cover was
included as the minimum Subtitle D requirement. Three different soil cover types
were modeled: sandy loam, silty loam, and silty clay loam soils. Table A.6 presents
the hydraulic parameters for these three soil types.
Table A.6 Hydraulic Parameters for the Modeled Soils
Soil Type
Sandy Loam
Silt Loam
Silty Clay
Loam
HELP
Soil
Number
6
9
12
Total
Porosity
(vol/vol)
0.453
0.501
0.471
Field
Capacity
(vol/vol)
0.190
0.284
0.342
Wilting
Point
(vol/vol)
0.085
0.135
0.210
Saturated
Hydraulic
Conductivity
(cm/sec)
0.000720
0.000190
0.000042
Other LF design criteria included:
• A cover crop of "fair" grass — this is the quality of grass cover
suggested by the HELP model for LFs where limitations to root zone
penetration and poor irrigation techniques may limit grass quality.
• The evaporation zone thickness selected for each location was
generally the depth suggested by the model for that location for a fair
grass crop; however, the evaporation zone thickness was not allowed
to exceed the soil thickness (24 inches).
• The leaf area index (LAI) selected for each location was that of fair
grass (2.0) unless the model indicated a lower maximum for that
location.
• The LF configuration was based on a one-acre facility with a 2% top
slope and a drainage length of 200 feet (one side of a square acre).
Runoff was assumed to be possible from 100% of the cover.
Table A.11 presents the LF infiltration rate data for the 102 climate stations.
For all four WMU types, the unlined LF infiltration rate for each soil type at each of
the 102 climate centers was used as the ambient regional recharge rate for that
climatic center and soil type.
A-11
-------
Appendix A Determination of Infiltration and Recharge Rates
Surface Impoundment
We calculated SI infiltration rates using the built-in SI module in EPACMTP
(see Section 4.3.4 of this document and Section 2.2.2.3 of the EPACMTP Technical
Background Document (U.S. EPA, 2003a)). This means that for EPACMTP, the SI
infiltration rate is not really an input parameter, rather the model calculates infiltration
rates "on the fly" during the simulation, as a function of impoundment ponding depth
and other SI characteristics. For unlined Sis, the primary parameters that control
the infiltration rate are the ponding depth in the impoundment, the thickness and
permeability of any accumulated sediment layer at the base of the impoundment,
and the presence of a 'clogged' (i.e., reduced permeability) layer of native soil
underneath the impoundment caused by the migration of solids from the
impoundment. In addition, EPACMTP checks that the calculated infiltration rate
does not result in an unrealistic degree of ground-water mounding (see Section
2.2.5 of the EPACMTP Technical Background Document (U.S. EPA, 2003a)).
To create the SI site data file for use with EPACMTP, we used unit-specific
data on SI ponding depths from EPA's Surface Impoundment Study (U.S. EPA,
2001). We assumed a fixed sediment layer thickness of 20 cm at the base of the
impoundment. The resulting sediment layer permeability has a relatively narrow
range of variation between 1.26x 10 "7 and 1.77x 10 "7 cm/s. We assumed that the
depth of clogging underneath the impoundment was 0.5 m in all cases, and that
saturated hydraulic conductivity of the clogged layer is 10% of that of the native soil
underlying the impoundment.
In the event that the SI is reported to have its base below the water table, we
calculated the infiltration using Darcy's law based on the hydraulic gradient across
the bottom of the impoundment unit, and the hydraulic conductivity of the
consolidated sediment at the bottom of the impoundment unit.
Waste Pile
For the purpose of estimating leaching rates, we considered WPs to be
similar to non-covered LFs with a total waste thickness of 10 feet. The infiltration
rates for unlined WPs were, therefore, generated with the HELP model using the
same general procedures as for LFs, but with the following modifications:
• No cover
We modeled the leachate flux through active, uncovered piles. We
modeled the WP surface as having no vegetation. The evaporative
zone depth was taken as the suggested HELP model value for the
"bare" condition at each climate center. The Leaf Area Index (LAI)
was set to zero to eliminate transpiration.
• Variable waste permeability
For uncovered WPs, we found that the infiltration rates predicted by
HELP model are sensitive to the permeability of the waste material
itself. Based on these results, we simulated WP infiltration rates for
A-12
-------
Appendix A
Determination of Infiltration and Recharge Rates
three different WP materials: relatively high permeability, moderate
permeability, and relatively low permeability (rather than three
different soil types as was done for the LF scenario). The HELP
model input parameters for the three waste types are presented in
Table A.7.
Table A.7 Moisture Retention Parameters for the Modeled WP Materials
Waste Type
Low Permeability
Moderate
Permeability
High
Permeability
HELP
Soil
Number
30
31
33
Total
Porosity
(vol/vol)
0.541
0.578
0.375
Field
Capacity
(vol/vol)
0.187
0.076
0.055
Wilting
Point
(vol/vol)
0.047
0.025
0.020
Saturated
Hydraulic
Conductivity
(cm/sec)
0.00005
0.00410
0.04100
We calculated WP infiltration rates for the 102 climate stations shown in
Figure A.1 and the three waste material permeabilities shown in Table A.7. Table
A. 12 presents the resulting WP infiltration rate values for all climate stations and
waste types.
Land Application Unit
LAUs were modeled with HELP using two soil layers. The top layer was
taken as six inches in thickness and represented the layer into which the waste was
applied. The bottom layer was of the same material type as the top layer and was
set at a thickness of 36 inches. Both of these layers were modeled as vertical
percolation layers. The same three soil types for LFs were also used for LAUs (see
Table A.6).
We assumed the waste applied to the LAU to be a sludge-type material with
a high water content. We also assumed a waste application rate of 7.25 inches per
year (in/yr) with the waste having a solids content of 20% and a unit weight of 75
Ib/ft3. Assuming that 100% of the water in the waste was available as free water, an
excess water amount of 5.8 in/yr, in addition to precipitation, would be available for
percolation. HELP model analyses showed that the additional water available for
percolation generally would have little effect on the simulated water balance and net
infiltration, except for sites located in arid regions of the United States with very little
natural precipitation. For more representative waste application rates, the effect
disappeared because introducing additional moisture in the simulated water balance
results in a commensurate increase in runoff and removal by evapotranspiration.
For this reason, the LAU infiltration rate for a given soil type is assumed to be the
same as the corresponding LF infiltration rate.
A-13
-------
Appendix A Determination of Infiltration and Recharge Rates
We calculated LAU infiltration rates for the 102 climate stations shown in
Figure A.1 and the three soil types shown in Table A.6. Table A. 13 presents the
resulting LAU infiltration rate values for all climate stations and soil types.
A.1.3 SINGLE-LINED WASTE UNITS
EPACMTP includes infiltration rates for single clay-lined LFs, WPs, and Sis.
In the case of LAUs, only unlined units are considered.
Landfill
We calculated infiltration rates for single-lined LFs using version 3.07 of the
HELP model. We modeled the LF as a four-layer system, consisting, from top to
bottom of:
• 1-foot percolation cover layer;
• 3-foot compacted clay cover with hydraulic conductivity of 1 x 10"7 cm/s ;
• 10-foot thick waste layer; and
• 3-foot thick compacted clay liner with a hydraulic conductivity of 1 x 10"7
cm/sec.
We simulated the cover layer as a loam drainage layer supporting a "fair"
cover crop with an evaporative zone depth equal to that associated with a fair cover
crop at the climate center. The remaining conditions were identical to those
described in Section A.1.2 for unlined LFs. Note that three different soil types were
not modeled, since the clay liner is the limiting factor affecting the infiltration rate, not
soil type. To avoid changing the standard format of the infiltration rates in the site
data file, the clay-lined LF infiltration rates are repeated in each of the three columns
that correspond to soil type in the case of unlined LFs. So in the course of a Monte
Carlo analysis using the regional site-based modeling methodology for a single-clay
lined LF, the soil type is correlated only to recharge rate.
In developing this default distribution of infiltration rates, we used the
grouping of climate stations into 25 regions of similar climatic conditions depicted in
Table A.5 in order to reduce the number of required HELP simulations. Rather than
calculating infiltration rates for each of the 102 individual climate stations, we
calculated infiltration rates for the 25 climate regions, and then assigned the same
value to each climate station in one group. To ensure a protective result, we chose
the climate center with the highest average precipitation in each climate region as
representative of that region. We calculated individual infiltration rates for each of
the five climate centers in Alaska, Hawaii, and Puerto Rico that were not assigned to
a climate region.
During the process of assembling the HELP infiltration values for the
EPACMTP model, we realized that the grouping of climate centers into regions for
clay-lined units resulted in a number of apparent anomalies in which the suggested
infiltration rate for a lined unit would be higher than the unlined infiltration rate at the
same climate station. This resulted from the fact that we used the infiltration rate for
A-14
-------
Appendix A Determination of Infiltration and Recharge Rates
the climate center with the highest annual precipitation in each region for clay-lined
units, but then compared it with a location-specific infiltration value for unlined units.
The occurrence of these anomalies was restricted to climate stations in arid parts of
the United States, and was noticeable only when the absolute magnitude of
infiltration was low. In order to remove these counter-intuitive results, we re-
calculated location-specific HELP infiltration rates for clay-lined units at 17 climate
stations (Glasgow, MT; Yakima, WA; Lander, WY; Cheyenne, WY; Pullman, WA;
Pocatello, ID; Grand Junction, CO; Denver, CO; Great Falls, MT; Salt Lake City, UT;
Cedar City, UT; El Paso, TX; Ely, NV; Las Vegas, NV; Rapid City, SD; Phoenix, AZ;
and Tucson, AZ). We then incorporated the location-specific infiltration rates for
these 17 climate stations into the database of infiltration rates in the site data file, to
replace the original regional values. The result is that some of the infiltration rates
for the single-clay lined LF scenario are regional values and some are location-
specific values. Table A.11 shows the infiltration rate values for clay-lined LFs.
Waste Pile
We calculated infiltration rates for single-lined WPs using the HELP model.
We modeled the WP as a two-layer system, consisting, from top to bottom, of:
• 10-foot thick, uncovered, waste layer; and
• 3-foot thick compacted clay liner with a hydraulic conductivity of 1 x 10"7
cm/sec.
Other parameters were set to the same values as in the unlined WP case,
including the three default waste material types (see Section A.1.2). We also
modeled a bare surface for the evaporative zone depth.
In developing the single-clay lined-WP infiltration rates, we used the same
grouping of climate stations in 25 climate regions as previously discussed for LFs.
We calculated individual infiltration rates for each of the five climate centers in
Alaska, Hawaii, and Puerto Rico that were not assigned to a climate region.
Analogous to the situation encountered for LFs, we found a number of
apparent anomalies between WP infiltration rates for unlined as compared to clay-
lined WPs, resulting from the use of regional infiltration values for clay-lined units.
The occurrence of these anomalies for WPs was also restricted to climate centers in
arid parts of the United States, for which the absolute magnitude of infiltration was
low. In order to remove these counter-intuitive results, we re-calculated location-
specific HELP infiltration rates for clay-lined WP units at 17 climate stations
(Glasgow, MT; Yakima, WA; Lander, WY; Cheyenne, WY; Pullman, WA; Pocatello,
ID; Grand Junction, CO; Denver, CO; Great Falls, MT; Salt Lake City, UT; Cedar
City, UT; El Paso, TX; Ely, NV; Las Vegas, NV; Rapid City, SD; Phoenix, AZ; and
Tucson, AZ). We then incorporated the location-specific infiltration rates for these
17 climate stations into the database of infiltration rates in the site data file, to
replace the original regional values, and made them part of a distribution package
for EPACMTP version 2. The result is that some of the infiltration rates for the
A-15
-------
Appendix A Determination of Infiltration and Recharge Rates
single-clay lined WP scenario are regional values and some are location-specific
values.
During the process of verifying the HELP-generated infiltration rates for clay-
lined units, we also replaced incorrect values for clay-lined WPs assigned to the
Lake Charles, LA and Miami, FL climate stations. These two climate stations have
high precipitation (Table A.5), but were assigned low infiltration rates. So for these
two climate stations, we re-ran the HELP model for the clay-lined WP scenario for
each of the three waste permeability values.
Table A.12 shows these finalized infiltration rate values for clay-lined WPs.
Surface Impoundment
For single-lined Sis, infiltration rates were calculated inside of EPACMTP in
the same manner as described in the Section A.1.2 for unlined units, with the
exception that we added a 3-foot compacted clay liner with a hydraulic conductivity
of 1 x10"7 cm/s at the bottom of the WMU, and we did not include the effect of
clogged native material due to the filtering effects of the liner.
A.1.4 INFILTRATION RATES FOR COMPOSITE-LINED UNITS
We conducted an information collection effort that involved searching the
available literature for data that quantify liner integrity and leachate infiltration
through composite liners (TetraTech, 2001). We then assembled these data and
applied them to develop the following methodologies for modeling infiltration from
composite-lined units:
Landfill and Waste Pile
We treated composite-lined LFs and WPs as being the same for the purpose
of determining infiltration rates. For these WMU's, we developed an infiltration rate
distribution from actual leak detection system (LDS) flow rates reported for clay
composite-lined LF cells, and incorporated them into an EPACMTP input file.
We based the distribution of composite-lined LF and WP infiltration rates on
available monthly average LDS flow rates from 27 LF cells reported by TetraTech
(2001). The data and additional detail for the 27 LF cells are provided in Appendix
D, Table D.5 of the IWEM Technical Background Document (U.S. EPA, 2003c). The
data included monthly average LDS flow rates for 22 operating LF cells and 5 closed
LF cells. The 27 LF cells are located in eastern United States: 23 in the
northeastern region, 1 in the mid-Atlantic region, and 3 in the southeastern region.
Each of the LF cells is underlain by a geomembrane/geosynthetic clay liner which
consists of a geomembrane of thickness between 1 and 1.5 mm (with the majority,
22 of 27, being 1.5 mm thick), overlying a geosynthetic clay layer of reported
thickness of 6 mm. The geomembrane is a flexible membrane layer made from
HOPE. The geosynthetic clay liner is a composite barrier consisting of two
A-16
-------
Appendix A
Determination of Infiltration and Recharge Rates
geotextile outer layers with a uniform core of bentonite clay to form a hydraulic
barrier. The liner system is underlain by a LDS.
We decided in this case to use a subset of the reported flow rates compiled
by TetraTech (2001) in developing the composite liner infiltration rates for
EPACMTP. We did not include LDS flow rates for geomembrane/compacted clay
composite-lined LF cells in our distribution. For compacted clay liners (including
composite geomembrane/ compacted clay liners), there is the potential for water to
be released during the consolidation of the clay liner and yield an unknown
contribution of water to LDS flow, such that it is very difficult to determine how much
of the LDS flow is due to liner leakage, versus how much is due to clay
consolidation. We also decided in this case to not use LDS flow rates from three
geomembrane/geosynthetic clay lined-cells. For one cell, flow rate data were
available for the cell's operating period and the cell's post-closure period. The
average flow rate for the cell was 26 liters/hectare/day when the cell was operating
and 59 liters/hectare/day when the cell was closed. We believe these flow rates,
which were among the highest reported, are difficult to interpret because the flow
rate from the closed cell was over twice the flow rate from the open cell, a pattern
inconsistent with the other open cell/closed cell data pairs we reviewed. For the two
other cells, additional verification of the data may be needed in order to fully
understand the reported flow rates.
The resulting cumulative probability distribution of infiltration rates for
composite-lined LFs and WPs for use in this application is based on the 27
remaining data points is presented in Table A.8. Note that over 50% of the values
are zero; that is, they have no measurable infiltration.
Table A.8 Cumulative Frequency Distribution of Infiltration Rate for
Composite-Lined LFs and WPs
I Percentile
| Infiltration Rate (m/yr)
0
0.0
10
0.0
25
0.0
50
0.0
75
7.30x1 0'5
90
1.78x10'4
100 I
4.01 x10'4 |
Surface Impoundment
For the surface impoundment scenario, the EPACMTP model derives a value
for leakage through circular defects (pin holes) in a composite liner using the
following equation developed by Bonaparte et al. (1989):
Q = 0.21 a01 h°-9 AC,0'74
(A.1)
where:
Q
a
h
steady-state rate of leakage through a single hole in the liner (m3/s)
area of hole in the geomembrane (m2)
head of liquid on top of geomembrane (m)
A-17
-------
Appendix A Determination of Infiltration and Recharge Rates
Ks = hydraulic conductivity of the low-permeability soil underlying the
geomembrane (m/s)
This equation is applicable to cases where there is good contact between the
geomembrane and the underlying compacted clay liner. In the course of a Monte
Carlo analysis using the regional site-based modeling methodology, the EPACMTP
model derives the infiltration rate for each SI unit in the nationwide database
included in the site data file using the above equation. This methodology uses the
unit-specific ponding depth data (corresponding to h in the above equation) from the
recent Surface Impoundment Study (U.S. EPA, 2001) in combination with a
distribution of leak densities (expressed as number of leaks per hectare) compiled
from 26 leak density values reported in TetraTech (2001). The leak densities are
based on liners installed with formal Construction Quality Assurance (CQA)
programs.
The 26 sites with leak density data are mostly located outside the United
States: 3 in Canada, 7 in France, 14 in United Kingdom, and 2 with unknown
locations. The WMUs at these sites (8 LFs, 4 Sis, and 14 unknown) are underlain
by a layer of geomembrane of thickness varying from 1.14 to 3 mm. The majority of
the geomembranes are made from HOPE (23 of 26) with the remaining 3 made from
prefabricated bituminous geomembrane or polypropylene. One of the sites has a
layer of compacted clay liner beneath the geomembrane, however, for the majority
of the sites (25 of 26) material types below the geomembrane layer are not reported.
The leak density data above were used for Sis. The leak density distribution is
shown in Table A.9. Table D.6, Appendix D of the IWEM Technical Background
Document (U.S. EPA, 2003c) provides additional detail.
To use the Bonaparte equation, the EPACMTP model assumes a uniform
leak size of 6 millimeters squared (mm2). This leak size is the middle of a range of
hole sizes reported by Rollin et al. (1999), who found that 25 percent of holes were
less than 2 mm2, 50 percent of holes were 2 to 10 mm2, and 25 percent of holes
were greater than 10 mm2. Additionally, the model assumes that the geomembrane
is underlain by a compacted clay liner whose hydraulic conductivity is 1 x10"7 cm/s.
In order to ascertain the plausibility of the leak density data, we conducted an
infiltration rate calculation to estimate the range of infiltration resulting from the leaks
in geomembrane. Because of the absence of documented infiltration data for Sis,
for comparison purposes we used the infiltration data for LFs, described previously
under the LF and WP sections, as a surrogate infiltration data set. Because the
comparison was made on the basis of LF data, we set the head of liquid above the
geomembrane to 0.3 m (1 foot) which is a typical maximum design head for LFs.
Calculation results are shown in Table D.6, Appendix D of the IWEM Technical
Background Document (U.S. EPA, 2003c). These results indicate that the
calculated leakage rates, based on the assumptions of above-geomembrane head,
hole dimension, hydraulic conductivity of the barrier underneath the geomembrane,
and good contact between the geomembrane and the barrier, agree favorably with
the observed LF flow rates reported in Table D.5, Appendix D of the IWEM
Technical Background Document (U.S. EPA, 2003c). This result provided
A-18
-------
Appendix A
Determination of Infiltration and Recharge Rates
confidence that the leak density data could be used as a reasonable basis for
calculating infiltration rates using actual SI ponding depths. The empirical
distribution of composite-lined infiltration rates for Sis is part of the EPACMTP input
file, if example input files for the composite-lined scenario are to be included in a
distribution package.
In order to use these data in EPACMTP, the user is required to specify the
unit's ponding depth. EPACMTP will then determine the unit's infiltration distribution
using the Bonaparte equation and the leak density distribution in Table A.9. The
resulting frequency distribution of calculated infiltration rates for composite-lined Sis
that are generated using the standard regional site-based modeling methodology is
presented in Table A. 10.
Table A.9 Cumulative Frequency Distribution of Leak Density for Composite-
Lined Sis
Percentile
Leak density
(No. Leaks/ha)
0
0
10
0
20
0
30
0
40
0.7
50
0.915
60
1.36
70
2.65
80
4.02
90
4.77
100
12.5
Table A.10 Cumulative Frequency Distribution of Infiltration Rate for
Composite-Lined Sis
Percentile
Infiltration Rate
(m/yr)
0
0.0
10
0.0
25
0.0
50
1.34x10'5
75
1.34x10'4
90
3.08x1 0'4
100
4.01 x10'3
Table A.11 HELP-Derived Landfill Infiltration Rates
Climate
Center
Index
1
2
3
4
5
6
7
8
9
Climate Center
City
Fresno
Boise
Denver
Grand
Junction
Pocatello
Glasgow
Bismarck
Pullman
Yakima
State
CA
ID
CO
CO
ID
MT
ND
WA
WA
No Liner Infiltration Rate
(m/yr)
Silt
Loam
0.0307
0.0008
0.0008
0.0000
0.0000
0.0099
0.0239
0.0069
0.0000
Sandy
Loam
0.0368
0.0094
0.0008
0.0000
0.0000
0.0074
0.0300
0.0132
0.0023
Silty
Clay
0.0381
0.0038
0.0036
0.0003
0.0000
0.0099
0.0196
0.0084
0.0003
Single Clay Liner Infiltration
Rate (m/yr)
Silt
Loam
0.0046
0.0046
0.0000
0.0000
0.0006
0.0001
0.0188
0.0002
0.0001
Sandy
Loam
0.0046
0.0046
0.0000
0.0000
0.0006
0.0001
0.0188
0.0002
0.0001
Silty
Clay
0.0046
0.0046
0.0000
0.0000
0.0006
0.0001
0.0188
0.0002
0.0001
A-19
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center
Index
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
Climate Center
City
Cheyenne
Lander
Los Angeles
Sacramento
San Diego
Santa Maria
Ely
Rapid City
Cedar City
Albuquerque
Las Vegas
Phoenix
Tucson
El Paso
Medford
Great Falls
Salt Lake
City
Grand
Island
Flagstaff
Dodge City
Midland
St. Cloud
E. Lansing
North Omaha
Tulsa
Brownsville
Dallas
Oklahoma
City
Concord
Pittsburgh
Portland
Caribou
State
WY
WY
CA
CA
CA
CA
NV
SD
UT
NM
NV
AZ
AZ
TX
OR
MT
UT
NE
AZ
KS
TX
MN
Ml
NE
OK
TX
TX
OK
NH
PA
OR
ME
No Liner Infiltration Rate
(m/yr)
Silt
Loam
0.0005
0.0033
0.0787
0.1024
0.0221
0.0947
0.0000
0.0005
0.0000
0.0000
0.0000
0.0000
0.0000
0.0076
0.2073
0.0036
0.0130
0.0442
0.0239
0.0135
0.0180
0.0602
0.1090
0.0671
0.0686
0.0549
0.0599
0.0612
0.1585
0.0894
0.4171
0.1082
Sandy
Loam
0.0013
0.0053
0.0950
0.0876
0.0340
0.1151
0.0000
0.0071
0.0008
0.0000
0.0000
0.0003
0.0003
0.0130
0.2309
0.0069
0.0269
0.0627
0.0630
0.0345
0.0254
0.0831
0.1452
0.0795
0.1006
0.1049
0.1067
0.0942
0.2057
0.1313
0.4387
0.1491
Silty
Clay
0.0086
0.0094
0.0699
0.0945
0.0241
0.0841
0.0003
0.0033
0.0000
0.0003
0.0018
0.0003
0.0005
0.0081
0.2096
0.0074
0.0185
0.0323
0.0226
0.0226
0.0135
0.0554
0.1102
0.0536
0.0465
0.0384
0.0531
0.0389
0.1372
0.0792
0.3927
0.0886
Single Clay Liner Infiltration
Rate (m/yr)
Silt
Loam
0.0000
0.0001
0.0013
0.0013
0.0013
0.0013
0.0000
0.0001
0.0001
0.0000
0.0001
0.0000
0.0000
0.0001
0.0432
0.0001
0.0005
0.0196
0.0241
0.0094
0.0094
0.0342
0.0374
0.0291
0.0241
0.0241
0.0241
0.0246
0.0432
0.0432
0.0432
0.0432
Sandy
Loam
0.0000
0.0001
0.0013
0.0013
0.0013
0.0013
0.0000
0.0001
0.0001
0.0000
0.0001
0.0000
0.0000
0.0001
0.0432
0.0001
0.0005
0.0196
0.0241
0.0094
0.0094
0.0342
0.0374
0.0291
0.0241
0.0241
0.0241
0.0246
0.0432
0.0432
0.0432
0.0432
Silty
Clay
0.0000
0.0001
0.0013
0.0013
0.0013
0.0013
0.0000
0.0001
0.0001
0.0000
0.0001
0.0000
0.0000
0.0001
0.0432
0.0001
0.0005
0.0196
0.0241
0.0094
0.0094
0.0342
0.0374
0.0291
0.0241
0.0241
0.0241
0.0246
0.0432
0.0432
0.0432
0.0432
A-20
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center
Index
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
Climate Center
City
Chicago
Burlington
Bangor
Rutland
Seattle
Montpelier
Sault St.
Marie
Put-in-Bay
Madison
Columbus
Cleveland
Des Moines
E. St. Louis
Columbia
Topeka
Tampa
San
Antonio
Hartford
Syracuse
Worchester
Augusta
Providence
Portland
Nashua
Ithaca
Boston
Schenectady
Lynchburg
New York
City
Philadelphia
Seabrook
Indianapolis
State
IL
VT
ME
VT
WA
VT
Ml
OH
Wl
OH
OH
IA
IL
MO
KS
FL
TX
CT
NY
MA
ME
Rl
ME
NH
NY
MA
NY
VA
NY
PA
NJ
IN
No Liner Infiltration Rate
(m/yr)
Silt
Loam
0.0798
0.1359
0.1471
0.1212
0.4384
0.1062
0.1651
0.0508
0.0912
0.0765
0.0780
0.1143
0.1435
0.1529
0.1049
0.0658
0.1095
0.1709
0.2545
0.2022
0.2116
0.2131
0.2294
0.2268
0.1684
0.2332
0.1473
0.3081
0.2436
0.2007
0.1814
0.1300
Sandy
Loam
0.1138
0.1781
0.2045
0.1598
0.4582
0.1483
0.2101
0.1003
0.1400
0.1158
0.1212
0.1641
0.1676
0.1989
0.1483
0.1031
0.1646
0.2228
0.3251
0.2591
0.2700
0.2863
0.2840
0.2812
0.2136
0.2383
0.1928
0.3612
0.2944
0.2609
0.2428
0.1862
Silty
Clay
0.0620
0.1166
0.1227
0.1008
0.4077
0.0879
0.1435
0.0495
0.0686
0.0663
0.0823
0.1156
0.0704
0.1224
0.0762
0.0475
0.0820
0.1405
0.2118
0.1697
0.1674
0.1753
0.1872
0.1943
0.1392
0.1542
0.1224
0.2570
0.1969
0.1641
0.1427
0.1064
Single Clay Liner Infiltration
Rate (m/yr)
Silt
Loam
0.0432
0.0432
0.0432
0.0432
0.0432
0.0432
0.0432
0.0409
0.0409
0.0409
0.0409
0.0409
0.0409
0.0409
0.0350
0.0253
0.0253
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0444
0.0444
0.0444
0.0444
0.0444
Sandy
Loam
0.0432
0.0432
0.0432
0.0432
0.0432
0.0432
0.0432
0.0409
0.0409
0.0409
0.0409
0.0409
0.0409
0.0409
0.0350
0.0253
0.0253
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0444
0.0444
0.0444
0.0444
0.0444
Silty
Clay
0.0432
0.0432
0.0432
0.0432
0.0432
0.0432
0.0432
0.0409
0.0409
0.0409
0.0409
0.0409
0.0409
0.0409
0.0350
0.0253
0.0253
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0445
0.0444
0.0444
0.0444
0.0444
0.0444
A-21
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center
Index
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
Climate Center
City
Cincinnati
Bridgeport
Orlando
Greensboro
Jacksonville
Watkinsville
Norfolk
Shreveport
Astoria
New Haven
Plainfield
Knoxville
Central Park
Lexington
Edison
Nashville
Little Rock
Tallahassee
New Orleans
Charleston
W. Palm
Beach
Atlanta
Lake
Charles
Miami
Annette
Bethel
Fairbanks
Honolulu
San Juan
State
OH
CT
FL
NC
FL
GA
VA
LA
OR
CT
MA
TN
NY
KY
NJ
TN
AK
FL
LA
SC
FL
GA
LA
FL
AK
AK
AK
HI
PR
No Liner Infiltration Rate
(m/yr)
Silt
Loam
0.1554
0.1953
0.1016
0.3256
0.1511
0.2891
0.2643
0.2296
1 .0762
0.3520
0.1900
0.4107
0.3363
0.3294
0.3122
0.4674
0.3531
0.5913
0.5893
0.2609
0.2611
0.3416
0.3647
0.1450
1 .6833
0.0564
0.0104
0.0523
0.1267
Sandy
Loam
0.2210
0.2464
0.1697
0.3896
0.2106
0.3556
0.3857
0.2939
1.1494
0.4628
0.2540
0.4460
0.4171
0.3970
0.3914
0.5395
0.4336
0.7308
0.7445
0.3287
0.3490
0.3993
0.4641
0.2201
1 .8354
0.0721
0.0234
0.0945
0.1923
Silty
Clay
0.1539
0.1615
0.0805
0.2705
0.1102
0.2332
0.1798
0.1842
0.9647
0.2855
0.1521
0.3543
0.2738
0.2700
0.2492
0.3769
0.2824
0.4564
0.4503
0.2123
0.1783
0.2822
0.2817
0.1019
1.4610
0.0554
0.0117
0.0366
0.0945
Single Clay Liner Infiltration
Rate (m/yr)
Silt
Loam
0.0444
0.0444
0.0362
0.0362
0.0362
0.0362
0.0362
0.0362
0.0526
0.0526
0.0526
0.0486
0.0486
0.0486
0.0486
0.0486
0.0477
0.0477
0.0477
0.0477
0.0477
0.0477
0.0492
0.0492
0.0338
0.0295
0.0094
0.0048
0.0193
Sandy
Loam
0.0444
0.0444
0.0362
0.0362
0.0362
0.0362
0.0362
0.0362
0.0526
0.0526
0.0526
0.0486
0.0486
0.0486
0.0486
0.0486
0.0477
0.0477
0.0477
0.0477
0.0477
0.0477
0.0492
0.0492
0.0338
0.0295
0.0094
0.0048
0.0193
Silty
Clay
0.0444
0.0444
0.0362
0.0362
0.0362
0.0362
0.0362
0.0362
0.0526
0.0526
0.0526
0.0486
0.0486
0.0486
0.0486
0.0486
0.0477
0.0477
0.0477
0.0477
0.0477
0.0477
0.0492
0.0492
0.0338
0.0295
0.0094
0.0048
0.0193
A-22
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.12 HELP-derived Waste Pile Infiltration Rates
Climate
Center
Index
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Climate Center
City
Fresno
Boise
Denver
Grand
Junction
Pocatello
Glasgow
Bismarck
Pullman
Yakima
Cheyenne
Lander
Los Angeles
Sacramento
San Diego
Santa Maria
Ely
Rapid City
Cedar City
Albuquerque
Las Vegas
Phoenix
Tucson
El Paso
Medford
Great Falls
Salt Lake
City
Grand Island
Flagstaff
Dodge City
Midland
State
CA
ID
CO
CO
ID
MT
ND
WA
WA
WY
WY
CA
CA
CA
CA
NV
SD
UT
NM
NV
AZ
AZ
TX
OR
MT
UT
NE
AZ
KS
TX
No Liner Infiltration Rate
(m/yr)
Low
Silt
Loam
0.0206
0.0053
0.0130
0.0053
0.0069
0.0056
0.0056
0.0112
0.0053
0.0053
0.0058
0.0792
0.0699
0.0361
0.0856
0.0056
0.0053
0.0056
0.0056
0.0206
0.0053
0.0064
0.0053
0.2261
0.0132
0.0091
0.0284
0.0170
0.0295
0.0381
Med
Sandy
Loam
0.0422
0.0003
0.0366
0.0003
0.0020
0.0043
0.0003
0.0259
0.0003
0.0003
0.0008
0.1331
0.1509
0.0658
0.1234
0.0135
0.0003
0.0003
0.0003
0.0231
0.0003
0.0003
0.0003
0.2497
0.0259
0.0193
0.0963
0.0404
0.1011
0.0757
High
Silty
Clay
0.0963
0.0318
0.0958
0.0178
0.0579
0.0554
0.0356
0.1001
0.0104
0.0140
0.0544
0.1885
0.1991
0.0658
0.1732
0.0752
0.0102
0.0259
0.0097
0.0556
0.0351
0.0279
0.0330
0.2990
0.0899
0.0747
0.2050
0.1016
0.1902
0.1283
Single Clay Liner Infiltration
Rate (m/yr)
Low
Silt
Loam
0.0136
0.0136
0.0020
0.0046
0.0059
0.0005
0.0124
0.0093
0.0049
0.0014
0.0042
0.0000
0.0000
0.0000
0.0000
0.0059
0.0010
0.0048
0.0016
0.0052
0.0047
0.0064
0.0058
0.1262
0.0019
0.0091
0.0422
0.0105
0.0033
0.0033
Med
Sandy
Loam
0.0434
0.0434
0.0013
0.0017
0.0015
0.0002
0.0689
0.0143
0.0047
0.0003
0.0012
0.0556
0.0556
0.0556
0.0556
0.0011
0.0011
0.0008
0.0151
0.0018
0.0020
0.0075
0.0026
0.1328
0.0047
0.0105
0.1347
0.1228
0.1063
0.1063
High
Silty Clay
Loam
0.0606
0.0606
0.0037
0.0020
0.0319
0.0234
0.0950
0.0344
0.0284
0.0071
0.0200
0.0718
0.0718
0.0718
0.0718
0.0036
0.0192
0.0053
0.0074
0.0080
0.0008
0.0017
0.0067
0.1313
0.0334
0.0368
0.1342
0.1234
0.1193
0.1193
A-23
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center
Index
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
Climate Center
City
St. Cloud
E. Lansing
North
Omaha
Tulsa
Brownsville
Dallas
Oklahoma
City
Concord
Pittsburg
Portland
Caribou
Chicago
Burlington
Bangor
Rutland
Seattle
Montpelier
Sault St.
Marie
Put-in-Bay
Madison
Columbus
Cleveland
Des Moines
E. St. Louis
Columbia
Topeka
Tampa
San Antonio
Hartford
Syracuse
Worchester
State
MN
Ml
NE
OK
TX
TX
OK
NH
PA
OR
ME
IL
VT
ME
VT
WA
VT
Ml
OH
Wl
OH
OH
IA
IL
MO
KS
FL
TX
CT
NY
MA
No Liner Infiltration Rate
(m/yr)
Low
Silt
Loam
0.0513
0.0602
0.0439
0.0907
0.0457
0.1067
0.0851
0.1410
0.1100
0.1003
0.1016
0.1158
0.4663
0.0820
0.4486
0.0485
0.1252
0.1283
0.0617
0.0790
0.0559
0.0889
0.1232
0.0897
0.1547
0.0841
0.1168
0.1059
0.1496
0.2487
0.1473
Med
Sandy
Loam
0.1516
0.1361
0.1618
0.2471
0.2268
0.2578
0.2423
0.2570
0.2131
0.1880
0.1758
0.2126
0.5331
0.1717
0.5060
0.1676
0.2098
0.2116
0.2022
0.1717
0.1481
0.1821
0.2634
0.2512
0.3101
0.2469
0.2954
0.2715
0.2611
0.4100
0.2751
High
Silty
Clay
0.2418
0.2197
0.2771
0.3452
0.3256
0.3543
0.3386
0.3147
0.2944
0.2705
0.2372
0.2725
0.5631
0.2852
0.5370
0.2685
0.3160
0.2858
0.3048
0.2606
0.2527
0.2680
0.3907
0.3546
0.4277
0.3620
0.4026
0.3724
0.3444
0.4844
0.3622
Single Clay Liner Infiltration
Rate (m/yr)
Low
Silt
Loam
0.0264
0.0481
0.0202
0.0050
0.0050
0.0050
0.0075
0.1125
0.1125
0.1125
0.1125
0.1125
0.1125
0.1125
0.1125
0.1125
0.1125
0.1125
0.0688
0.0688
0.0688
0.0688
0.0688
0.0688
0.0688
0.0174
0.0200
0.0200
0.1193
0.1193
0.1193
Med
Sandy
Loam
0.1262
0.1153
0.1264
0.1329
0.1329
0.1329
0.1310
0.1273
0.1273
0.1273
0.1273
0.1273
0.1273
0.1273
0.1273
0.1273
0.1273
0.1273
0.1325
0.1325
0.1325
0.1325
0.1325
0.1325
0.1325
0.1305
0.1339
0.1339
0.1286
0.1286
0.1286
High
Silty Clay
Loam
0.1255
0.1114
0.1265
0.1318
0.1318
0.1318
0.1298
0.1266
0.1266
0.1266
0.1266
0.1266
0.1266
0.1266
0.1266
0.1266
0.1266
0.1266
0.1321
0.1321
0.1321
0.1321
0.1321
0.1321
0.1321
0.1302
0.1333
0.1333
0.1279
0.1279
0.1279
A-24
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center
Index
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
Climate Center
City
Augusta
Providence
Portland
Nashua
Ithaca
Boston
Schenectady
Lynchburg
New York
City
Philadelphia
Seabrook
Indianapolis
Cincinnati
Bridgeport
Orlando
Greensboro
Jacksonville
Watkinsville
Norfolk
Shreveport
Astoria
New Haven
Plainfield
Knoxville
Central Park
Lexington
Edison
Nashville
Little Rock
Tallahassee
New Orleans
Charleston
State
ME
Rl
ME
NH
NY
MA
NY
VA
NY
PA
NJ
IN
OH
CT
FL
NC
FL
GA
VA
LA
OR
CT
MA
TN
NY
KY
NJ
TN
AK
FL
LA
SC
No Liner Infiltration Rate
(m/yr)
Low
Silt
Loam
0.1692
0.1821
0.1765
0.1773
0.1806
0.2090
0.1770
0.2830
0.1234
0.1577
0.1783
0.2121
0.1773
0.2113
0.3061
0.2426
0.2591
0.2992
0.1694
0.1996
0.9865
0.3561
0.1910
0.2804
0.3045
0.4039
0.3000
0.4173
0.3332
0.5024
0.3018
0.2794
Med
Sandy
Loam
0.3216
0.3482
0.3335
0.3312
0.3132
0.3254
0.2786
0.4590
0.2690
0.3406
0.3096
0.3988
0.3526
0.3691
0.4839
0.4666
0.4455
0.4544
0.3835
0.4087
1.2136
0.5423
0.3033
0.4521
0.4897
0.5415
0.5286
0.6144
0.5288
0.8486
0.5380
0.4829
High
Silty
Clay
0.4209
0.4610
0.4148
0.4267
0.3861
0.3922
0.3622
0.5654
0.3818
0.4709
0.4133
0.5184
0.4757
0.4717
0.5941
0.5903
0.5710
0.5535
0.4737
0.5263
1 .2637
0.5098
0.3950
0.5733
0.6066
0.6421
0.6525
0.7435
0.6414
0.9792
0.6683
0.5832
Single Clay Liner Infiltration
Rate (m/yr)
Low
Silt
Loam
0.1193
0.1193
0.1193
0.1193
0.1193
0.1193
0.1193
0.1062
0.1062
0.1062
0.1062
0.1062
0.1062
0.1062
0.0804
0.0804
0.0804
0.0804
0.0804
0.0804
0.1316
0.1316
0.1316
0.1255
0.1255
0.1255
0.1255
0.1255
0.1184
0.1184
0.1184
0.1184
Med
Sandy
Loam
0.1286
0.1286
0.1286
0.1286
0.1286
0.1286
0.1286
0.1336
0.1336
0.1336
0.1336
0.1336
0.1336
0.1336
0.1273
0.1273
0.1273
0.1273
0.1273
0.1273
0.1355
0.1355
0.1355
0.1352
0.1352
0.1352
0.1352
0.1352
0.1351
0.1351
0.1351
0.1351
High
Silty Clay
Loam
0.1279
0.1279
0.1279
0.1279
0.1279
0.1279
0.1279
0.1332
0.1332
0.1332
0.1332
0.1332
0.1332
0.1332
0.1266
0.1266
0.1266
0.1266
0.1266
0.1266
0.1350
0.1350
0.1350
0.1349
0.1349
0.1349
0.1349
0.1349
0.1347
0.1347
0.1347
0.1347
A-25
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center
Index
94
95
96
97
98
99
100
101
102
Climate Center
City
W. Palm
Beach
Atlanta
Lake
Charles
Miami
Annette
Bethel
Fairbanks
Honolulu
San Juan
State
FL
GA
LA
FL
AK
AK
AK
HI
PR
No Liner Infiltration Rate
(m/yr)
Low
Silt
Loam
0.5126
0.2553
0.1615
0.3891
1 .5373
0.0502
0.0077
0.0501
0.1498
Med
Sandy
Loam
0.8219
0.5641
0.4227
0.6066
1.8146
0.0725
0.0167
0.1083
0.2883
High
Silty
Clay
0.9581
0.6904
0.5331
0.7201
1 .8789
0.1225
0.0777
0.1983
0.4442
Single Clay Liner Infiltration
Rate (m/yr)
Low
Silt
Loam
0.1184
0.1184
0.0489
0.0489
0.1352
0.0352
0.0098
0.0323
0.0637
Med
Sandy
Loam
0.1351
0.1351
0.0558
0.0558
0.1357
0.0364
0.0118
0.0494
0.0793
High
Silty Clay
Loam
0.1347
0.1347
0.0927
0.0927
0.1354
0.0660
0.0407
0.0871
0.1114
A-26
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.13 HELP-derived Land Application Unit Infiltration Rates
Climate
Center Index
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Climate Center
City
Fresno
Boise
Denver
Grand Junction
Pocatello
Glasgow
Bismarck
Pullman
Yakima
Cheyenne
Lander
Los Angeles
Sacramento
San Diego
Santa Maria
Ely
Rapid City
Cedar City
Albuquerque
Las Vegas
Phoenix
Tucson
El Paso
Medford
Great Falls
Salt Lake City
Grand Island
Flagstaff
Dodge City
Midland
St. Cloud
E. Lansing
North Omaha
Tulsa
Brownsville
State
CA
ID
CO
CO
ID
MT
ND
WA
WA
WY
WY
CA
CA
CA
CA
NV
SD
UT
NM
NV
AZ
AZ
TX
OR
MT
UT
NE
AZ
KS
TX
MN
Ml
NE
OK
TX
No Liner Infiltration Rate (m/yr)
Silt Loam
0.0307
0.0008
0.0008
0.0000
0.0000
0.0099
0.0239
0.0069
0.0000
0.0005
0.0033
0.0787
0.1024
0.0221
0.0947
0.0000
0.0005
0.0000
0.0000
0.0000
0.0000
0.0000
0.0076
0.2073
0.0036
0.0130
0.0442
0.0239
0.0135
0.0180
0.0602
0.1090
0.0671
0.0686
0.0549
Sandy Loam
0.0368
0.0094
0.0008
0.0000
0.0000
0.0074
0.0300
0.0132
0.0023
0.0013
0.0053
0.0950
0.0876
0.0340
0.1151
0.0000
0.0071
0.0008
0.0000
0.0000
0.0003
0.0003
0.0130
0.2309
0.0069
0.0269
0.0627
0.0630
0.0345
0.0254
0.0831
0.1452
0.0795
0.1006
0.1049
Silty Clay Loam
0.0381
0.0038
0.0036
0.0003
0.0000
0.0099
0.0196
0.0084
0.0003
0.0086
0.0094
0.0699
0.0945
0.0241
0.0841
0.0003
0.0033
0.0000
0.0003
0.0018
0.0003
0.0005
0.0081
0.2096
0.0074
0.0185
0.0323
0.0226
0.0226
0.0135
0.0554
0.1102
0.0536
0.0465
0.0384
A-27
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center Index
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
Climate Center
City
Dallas
Oklahoma City
Concord
Pittsburg
Portland
Caribou
Chicago
Burlington
Bangor
Rutland
Seattle
Montpelier
Sault St. Marie
Put-in-Bay
Madison
Columbus
Cleveland
Des Moines
E. St. Louis
Columbia
Topeka
Tampa
San Antonio
Hartford
Syracuse
Worchester
Augusta
Providence
Portland
Nashua
Ithaca
Boston
Schenectady
Lynchburg
New York City
Philadelphia
Seabrook
State
TX
OK
NH
PA
OR
ME
IL
VT
ME
VT
WA
VT
Ml
OH
Wl
OH
OH
IA
IL
MO
KS
FL
TX
CT
NY
MA
ME
Rl
ME
NH
NY
MA
NY
VA
NY
PA
NJ
No Liner Infiltration Rate (m/yr)
Silt Loam
0.0599
0.0612
0.1585
0.0894
0.4171
0.1082
0.0798
0.1359
0.1471
0.1212
0.4384
0.1062
0.1651
0.0508
0.0912
0.0765
0.0780
0.1143
0.1435
0.1529
0.1049
0.0658
0.1095
0.1709
0.2545
0.2022
0.2116
0.2131
0.2294
0.2268
0.1684
0.2332
0.1473
0.3081
0.2436
0.2007
0.1814
Sandy Loam
0.1067
0.0942
0.2057
0.1313
0.4387
0.1491
0.1138
0.1781
0.2045
0.1598
0.4582
0.1483
0.2101
0.1003
0.1400
0.1158
0.1212
0.1641
0.1676
0.1989
0.1483
0.1031
0.1646
0.2228
0.3251
0.2591
0.2700
0.2863
0.2840
0.2812
0.2136
0.2383
0.1928
0.3612
0.2944
0.2609
0.2428
Silty Clay Loam
0.0531
0.0389
0.1372
0.0792
0.3927
0.0886
0.0620
0.1166
0.1227
0.1008
0.4077
0.0879
0.1435
0.0495
0.0686
0.0663
0.0823
0.1156
0.0704
0.1224
0.0762
0.0475
0.0820
0.1405
0.2118
0.1697
0.1674
0.1753
0.1872
0.1943
0.1392
0.1542
0.1224
0.2570
0.1969
0.1641
0.1427
A-28
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center Index
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
Climate Center
City
Indianapolis
Cincinnati
Bridgeport
Orlando
Greensboro
Jacksonville
Watkinsville
Norfolk
Shreveport
Astoria
New Haven
Plainfield
Knoxville
Central Park
Lexington
Edison
Nashville
Little Rock
Tallahassee
New Orleans
Charleston
W. Palm Beach
Atlanta
Lake Charles
Miami
Annette
Bethel
Fairbanks
Honolulu
San Juan
State
IN
OH
CT
FL
NC
FL
GA
VA
LA
OR
CT
MA
TN
NY
KY
NJ
TN
AK
FL
LA
SC
FL
GA
LA
FL
AK
AK
AK
HI
PR
No Liner Infiltration Rate (m/yr)
Silt Loam
0.1300
0.1554
0.1953
0.1016
0.3256
0.1511
0.2891
0.3122
0.2296
1 .0762
0.3520
0.1900
0.4107
0.3363
0.3294
0.3122
0.4674
0.3531
0.5913
0.5893
0.2609
0.2611
0.3416
0.3647
0.1450
1 .8049
0.1849
0.1463
0.0541
0.1491
Sandy Loam
0.1862
0.2210
0.2464
0.1697
0.3896
0.2106
0.3556
0.0000
0.2939
1.1494
0.4628
0.2540
0.4460
0.4171
0.3970
0.3914
0.5395
0.4336
0.7308
0.7445
0.3287
0.3490
0.3993
0.4641
0.2201
1 .9771
0.1981
0.1483
0.0983
0.2164
Silty Clay Loam
0.1064
0.1539
0.1615
0.0805
0.2705
0.1102
0.2332
0.2685
0.1842
0.9647
0.2855
0.1521
0.3543
0.2738
0.2700
0.2492
0.3769
0.2824
0.4564
0.4503
0.2123
0.1783
0.2822
0.2817
0.1019
1.5159
0.1781
0.1445
0.0363
0.1049
A-29
-------
Appendix A
Determination of Infiltration and Recharge Rates
Table A.14 HELP-derived Regional Recharge Rates
Climate
Center Index
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Climate Center
City
Fresno
Boise
Denver
Grand Junction
Pocatello
Glasgow
Bismarck
Pullman
Yakima
Cheyenne
Lander
Los Angeles
Sacramento
San Diego
Santa Maria
Ely
Rapid City
Cedar City
Albuquerque
Las Vegas
Phoenix
Tucson
El Paso
Medford
Great Falls
Salt Lake City
Grand Island
Flagstaff
Dodge City
Midland
St. Cloud
E. Lansing
North Omaha
Tulsa
Brownsville
State
CA
ID
CO
CO
ID
MT
ND
WA
WA
WY
WY
CA
CA
CA
CA
NV
SD
UT
NM
NV
AZ
AZ
TX
OR
MT
UT
NE
AZ
KS
TX
MN
Ml
NE
OK
TX
Ambient Regional Recharge Rate (m/yr)
Soil Type
Silt Loam
0.0307
0.0008
0.0008
0.0000
0.0000
0.0099
0.0239
0.0069
0.0000
0.0005
0.0033
0.0787
0.1024
0.0221
0.0947
0.0000
0.0005
0.0000
0.0000
0.0000
0.0000
0.0000
0.0076
0.2073
0.0036
0.0130
0.0442
0.0239
0.0135
0.0180
0.0602
0.1090
0.0671
0.0686
0.0549
Sandy Loam
0.0368
0.0094
0.0008
0.0000
0.0000
0.0074
0.0300
0.0132
0.0023
0.0013
0.0053
0.0950
0.0876
0.0340
0.1151
0.0000
0.0071
0.0008
0.0000
0.0000
0.0003
0.0003
0.0130
0.2309
0.0069
0.0269
0.0627
0.0630
0.0345
0.0254
0.0831
0.1452
0.0795
0.1006
0.1049
Silty Clay Loam
0.0381
0.0038
0.0036
0.0003
0.0000
0.0099
0.0196
0.0084
0.0003
0.0086
0.0094
0.0699
0.0945
0.0241
0.0841
0.0003
0.0033
0.0000
0.0003
0.0018
0.0003
0.0005
0.0081
0.2096
0.0074
0.0185
0.0323
0.0226
0.0226
0.0135
0.0554
0.1102
0.0536
0.0465
0.0384
A-30
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center Index
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
Climate Center
City
Dallas
Oklahoma City
Concord
Pittsburg
Portland
Caribou
Chicago
Burlington
Bangor
Rutland
Seattle
Montpelier
Sault St. Marie
Put-in-Bay
Madison
Columbus
Cleveland
Des Moines
E. St. Louis
Columbia
Topeka
Tampa
San Antonio
Hartford
Syracuse
Worchester
Augusta
Providence
Portland
Nashua
Ithaca
Boston
Schenectady
Lynchburg
New York City
Philadelphia
State
TX
OK
NH
PA
OR
ME
IL
VT
ME
VT
WA
VT
Ml
OH
Wl
OH
OH
IA
IL
MO
KS
FL
TX
CT
NY
MA
ME
Rl
ME
NH
NY
MA
NY
VA
NY
PA
Ambient Regional Recharge Rate (m/yr)
Soil Type
Silt Loam
0.0599
0.0612
0.1585
0.0894
0.4171
0.1082
0.0798
0.1359
0.1471
0.1212
0.4384
0.1062
0.1651
0.0508
0.0912
0.0765
0.0780
0.1143
0.1435
0.1529
0.1049
0.0658
0.1095
0.1709
0.2545
0.2022
0.2116
0.2131
0.2294
0.2268
0.1684
0.2332
0.1473
0.3081
0.2436
0.2007
Sandy Loam
0.1067
0.0942
0.2057
0.1313
0.4387
0.1491
0.1138
0.1781
0.2045
0.1598
0.4582
0.1483
0.2101
0.1003
0.1400
0.1158
0.1212
0.1641
0.1676
0.1989
0.1483
0.1031
0.1646
0.2228
0.3251
0.2591
0.2700
0.2863
0.2840
0.2812
0.2136
0.2383
0.1928
0.3612
0.2944
0.2609
Silty Clay Loam
0.0531
0.0389
0.1372
0.0792
0.3927
0.0886
0.0620
0.1166
0.1227
0.1008
0.4077
0.0879
0.1435
0.0495
0.0686
0.0663
0.0823
0.1156
0.0704
0.1224
0.0762
0.0475
0.0820
0.1405
0.2118
0.1697
0.1674
0.1753
0.1872
0.1943
0.1392
0.1542
0.1224
0.2570
0.1969
0.1641
A-31
-------
Appendix A
Determination of Infiltration and Recharge Rates
Climate
Center Index
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
Climate Center
City
Seabrook
Indianapolis
Cincinnati
Bridgeport
Orlando
Greensboro
Jacksonville
Watkinsville
Norfolk
Shreveport
Astoria
New Haven
Plainfield
Knoxville
Central Park
Lexington
Edison
Nashville
Little Rock
Tallahassee
New Orleans
Charleston
W. Palm Beach
Atlanta
Lake Charles
Miami
Annette
Bethel
Fairbanks
Honolulu
San Juan
State
NJ
IN
OH
CT
FL
NC
FL
GA
VA
LA
OR
CT
MA
TN
NY
KY
NJ
TN
AK
FL
LA
SC
FL
GA
LA
FL
AK
AK
AK
HI
PR
Ambient Regional Recharge Rate (m/yr)
Soil Type
Silt Loam
0.1814
0.1300
0.1554
0.1953
0.1016
0.3256
0.1511
0.2891
0.3122
0.2296
1 .0762
0.3520
0.1900
0.4107
0.3363
0.3294
0.3122
0.4674
0.3531
0.5913
0.5893
0.2609
0.2611
0.3416
0.3647
0.1450
1 .6833
0.0564
0.0104
0.0523
0.1267
Sandy Loam
0.2428
0.1862
0.2210
0.2464
0.1697
0.3896
0.2106
0.3556
0.0000
0.2939
1.1494
0.4628
0.2540
0.4460
0.4171
0.3970
0.3914
0.5395
0.4336
0.7308
0.7445
0.3287
0.3490
0.3993
0.4641
0.2201
1 .8354
0.0721
0.0234
0.0945
0.1923
Silty Clay Loam
0.1427
0.1064
0.1539
0.1615
0.0805
0.2705
0.1102
0.2332
0.2685
0.1842
0.9647
0.2855
0.1521
0.3543
0.2738
0.2700
0.2492
0.3769
0.2824
0.4564
0.4503
0.2123
0.1783
0.2822
0.2817
0.1019
1.4610
0.0554
0.0117
0.0366
0.0945
A.1.5 DETERMINATION OF RECHARGE RATES
We estimated recharge rates for the three primary soil types across the
United States (SNL, SLT, and SCL) and ambient climate conditions at 102 climate
A-32
-------
Appendix A Determination of Infiltration and Recharge Rates
stations through the use of the HELP water-balance model as summarized in
Sections A.1.1 and A.1.2. We assumed the ambient regional recharge rate for a
given climate center and soil type (for all four WMU types) is the same as the
corresponding unlined LF infiltration rate. Table A.14 presents the resulting regional
recharge rates for all climate stations and soil types.
A-33
-------
Appendix A Determination of Infiltration and Recharge Rates
A.2 REFERENCES
ABB Environmental Services, 1995. Estimation of Leachate Rates from Industrial
Waste Management Facilities. August, 1995.
Bonaparte, Ft., J. P. Giroud, and B.A. Cross, 1989. Rates of leakage through landfill
liners. Geosynthetics 1989 Conference, San Diego, California.
Rollin, A.L., M. Marcotte, T. Jacquelin, and L. Chaput, 1999. Leak location in
exposed geomembrane liners using an electrical leak detection technique.
Geosynthetics '99: Specifying Geosynthetics and Developing Design Details,
Vol.2, pp 615-626.
Schroeder, P.R., T.S., Dozier, P.A. Zappi, B.M. McEnroe, J. W. Sjostrom, and R.L.
Peton, 1994. The hydrologic evaluation of landfill performance model
(HELP): Engineering Documentation for Version 3. EPA/600/R-94/1686.
United States Environmental Protection Agency, Cincinnati, OH.
TetraTech, Inc., 2001. Characterization of infiltration rate data to support ground-
water modeling efforts (Draft). Prepared for the U.S. Environmental
Protection Agency, Office of Solid Waste, Contract No. 68-W6-0061, May,
2001.
U.S. EPA, 2001. Industrial Surface Impoundments in the United States. U.S. EPA
Office of Solid Waste, Washington, DC 20460. USEPA 530-R-01-005.
U.S. EPA, 2003a. EPACMTP Technical Background Document. Office of Solid
Waste, Washington, DC.
U.S. EPA, 2003c. IWEM Technical Background Document. Office of Solid Waste,
Washington, DC.
A-34
-------
APPENDIX B
NON-LINEAR SORPTION ISOTHERMS CALCULATED
USING THE MINTEQA2 MODEL
-------
This page intentionally left blank.
-------
TABLE OF CONTENTS
Page
LIST OF FIGURES B-ii
LIST OF TABLES B-iii
1.0 INTRODUCTION B-1
2.0 MODEL INPUT DATA AND PROCEDURE B-3
2.1 METALS OF INTEREST B-3
2.2 GROUND-WATER COMPOSITION B-4
2.3 MODEL ADSORBENTS B-6
2.3.1 Goethite Sorbent B-7
2.3.2 Paniculate Organic Matter Sorbent B-10
2.4 LEACHATE ORGANIC MATTER B-13
2.5 MINTEQA2 MODELING PROCEDURE B-15
2.5.1 Pre-equilibration With Sorbents B-15
2.5.2 Titrating Systems To New pH Values B-15
2.5.3 Addition Of Leachate Acids And Contaminant Metal ... B-16
3.0 RESULTS B-17
3.1 EXAMPLE ISOTHERMS B-17
4.0 ASSUMPTIONS AND LIMITATIONS B-21
4.1 GROUND-WATER CHARACTERIZATION ISSUES B-21
4.2 SORBENT CHARACTERIZATION ISSUES B-21
4.3 LEACHATE CHARACTERIZATION ISSUES B-22
4.4 OTHER ISSUES B-23
5.0 REFERENCES B-25
B-i
-------
LIST OF FIGURES
Page
Figure B.1 MINTEQA2 Computes the Equilibrium Distribution of Metal B-2
Figure B.2 Cr(VI) Isotherms Illustrating Influence of pH B-18
Figure B.3 Pb Isotherms Illustrating Influence of FeOx
Sorbent Concentration B-19
Figure B.4 Pb Isotherms Illustrating Influence of POM/DOM Concentration. B-19
Figure B.5 Cu Isotherms Illustrating Influence of LOM Concentration B-20
Figure B.6 Relevant pH-Eh Window And Stable Iron Phases
(after Hem, 1977) B-24
B-ii
-------
LIST OF TABLES
Page
Table B.1 Settings For The Hydrogeologic Environment Parameter
In EPACMTP B-5
Table B.2 Composition Of Representative Ground Waters B-6
Table B.3 Concentration Levels For Goethite Sorbent B-7
Table B.4 Model Parameters For The Goethite Sorbent B-8
Table B.5 Goethite Sorption Reactions Used In MINTEQA2 B-9
Table B.6 POM And DOM Concentration Levels B-12
Table B.7 Site Concentrations For POM And DOM Components
In MINTEQA2 B-12
Table B.8 POM And DOM Reactions Included In MINTEQA2 Modeling ... B-13
Table B.9 Model Concentrations Of Representative Leachate Acids B-14
B-iii
-------
This page intentionally left blank.
-------
APPENDIX B
NON-LINEAR SORPTION ISOTHERMS CALCULATED
USING THE MINTEQA2 MODEL
1.0 INTRODUCTION
This appendix describes the development of concentration-dependent metal
partition coefficients for use in EPACMTP. In the subsurface, metal contaminants
undergo reactions with ligands in the pore water and with surface sites on the solid
aquifer or soil matrix material. Reactions in which the metal is bound to the solid matrix
are referred to as sorption reactions and metal that is bound to the solid is said to be
sorbed. The ratio of the concentration of metal sorbed to the concentration in the
mobile aqueous phase at equilibrium is referred to as the partition coefficient (Kd).
During contaminant transport, sorption to the solid matrix results in retardation of the
contaminant front. Thus, transport models such as EPACMTP incorporate the
contaminant partition coefficient into the overall retardation factor (the ratio of the
average linear particle velocity to the velocity of that portion of the plume where the
contaminant is at 50 percent dilution). Using Kd in EPACMTP transport modeling
implies the assumption that local equilibrium between the solutes and the sorbents is
attained. This implies that the rate of sorption reactions is fast relative to advective-
dispersive transport of the contaminant.
EPACMTP incorporates the option of using tables of non-linear sorption
isotherms. These isotherms reflect the tendency of Kd to decrease as the total metal
concentration in the system increases. The non-linear isotherms available for use in
EPACMTP are specified in terms of the dissolved metal concentration and the
corresponding sorbed concentration at a series of total metal concentrations. The
isotherms were estimated using the geochemical speciation model, MINTEQA2. For
a particular metal, Kd values in a soil or aquifer are dependent upon the metal
concentration and various geochemical characteristics of the soil or aquifer and the
associated pore water. Geochemical parameters that have the greatest influence on
the magnitude of Kd include the pH of the system and the nature and concentration of
sorbents associated with the soil or aquifer matrix. In the subsurface beneath a
disposal facility, the concentration of leachate constituents may also influence Kd.
Although the dependence of metal partitioning on the total metal concentration and on
pH and other geochemical characteristics is apparent from partitioning studies reported
in the scientific literature, Kd values for many metals are not available for the range of
metal concentrations or geochemical conditions needed in risk assessment modeling.
For this reason, we chose to use an equilibrium speciation model, MINTEQA2, to
estimate partition coefficients. Using a speciation model allows Kd values to be
estimated for a range of total metal concentrations in various model systems designed
to depict natural variability in those geochemical characteristics that most influence
metal partitioning.
B-1
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
MINTEQA2
We produced the non-linear sorption isotherms for metals by using MINTEQA21,
a geochemical speciation model maintained and distributed by the U.S. EPA. From
input data consisting of total concentrations of chemical constituents, MINTEQA2
calculates the fraction of a contaminant metal that is dissolved, adsorbed, and
precipitated at equilibrium (see Figure B.1). The total concentrations of major and
minor ions, trace metals and other chemicals are specified in terms of key species
known as components. MINTEQA2 automatically includes an extensive database of
solution species and solid phase species representing reaction products of two or more
of the components. The model does not automatically include sorption reactions, but
these can be included in the calculations if supplied by the user. When sorption
reactions are included, the dimensionless partition coefficient can be calculated from
the ratio of the sorbed metal concentration to the dissolved metal concentration at
equilibrium. The dimensionless partition coefficient is converted to Kd with units of liters
per kilogram (L/kg) by normalizing by the mass of soil (in kilograms) with which one liter
of pore water is equilibrated (the phase ratio). An isotherm is generated when the
equilibrium metal distribution between sorbed and dissolved fractions is estimated for
a series of total metal concentrations.
Progress in accounting for sorption in equilibrium calculations over the past
decade has resulted in the development of coherent databases of sorption reactions for
particular sorbents. These databases include acid-base sorption reactions and
reactions for major ions in aquatic systems (Ca, Mg, SO4, etc.). Including such
reactions along with those representing sorption of trace metals makes it possible to
estimate sorption in systems of varying pH and composition. Examples of coherent
databases of sorption reactions include that for the hydrous ferric oxide surface
presented by Dzombak and Morel (1990) and a similar database for goethite presented
by Mathur
(1995).
Total
Component
Concentrations
Dissolved
Adsorbed
Precipitated
Figure B.1 MINTEQA2 Computes the Equilibrium
Distribution of Metal.
The version of MINTEQA2 used in this modeling was modified from version 4.02.
B-2
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
2.0 MODEL INPUT DATA AND PROCEDURE
Expected natural variability in Kd for a particular metal was included in the
MINTEQA2 modeling by including variability in important input parameters upon which
Kd depends. The input parameters for which variability was incorporated include
ground-water composition, pH, concentration of sorbents, concentration of leachate
organic matter (LOM), and concentration of metal.
The ground-water chemistry exerts an important influence on metal partition
coefficients. The major ions present in ground water may compete with trace metals
for sorption sites. Also, inorganic ligands may complex with some metals reducing their
tendency to sorb. For the purposes of this model, we assumed that the influence of
ground-water composition on metal sorption can be adequately represented by dividing
the universe of ground-water compositional types into two categories: carbonate and
non-carbonate. Further, we assumed that the influence of pH can be represented by
depicting each of these two ground water types at a number of equilibrium pH values
within its natural range of variability. Furthermore, the depiction of each ground-water
chemistry at multiple pH values can be accomplished by titrating the natural ground-
water chemistry with a mineral acid or base.
The influence of variability in sorption capacity of soil and aquifer materials was
included in the Kd estimates by equilibrating the ground-water systems with various
concentrations of commonly occurring natural sorbents. Two common sorbents in soil
and ground-water systems are ferric oxyhydroxide and paniculate organic matter
(POM). Although other sorbents such as clay minerals, carbonate minerals, hydrous
aluminum and manganese oxides, and silica may sorb metals in the subsurface,
representation of ferric oxyhydroxide and paniculate organic matter in the model is
sufficient to provide a reasonable assessment of the sorption capacity of most natural
ground-water systems.
Leachate organic matter present as various well-characterized acids may
influence the propensity for metal sorption. The influence of leachate organic matter
on metal sorption is characterized by including representative acids present at
concentration levels that span the expected range.
2.1 METALS OF INTEREST
The metal contaminants whose partition coefficients have been estimated using
MINTEQA2 include arsenic (As), antimony (Sb), barium (Ba), beryllium (Be), cadmium
(Cd), cobalt (Co), copper (Cu), chromium (Cr), fluoride (F), mercury (Hg), manganese
(Mn), molybdenum (Mo), lead (Pb), nickel (Ni), selenium (Se), silver (Ag), thallium (Tl),
vanadium (V), and zinc (Zn).
Several of these metals occur naturally in more than one oxidation state. The
modeling described here is restricted to the oxidation states that are most likely to occur
in waste systems or most likely to be mobile in ground-water waste systems. For
arsenic, chromium, and selenium, partition coefficients were estimated for two oxidation
B-3
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
states. These were: As(lll) and As(V), Cr(lll) and Cr(VI), and Se(IV) and Se(VI). For
antimony, molybdenum, thallium, and vanadium, only one oxidation state was modeled
although multiple oxidation states occur. For all four of these metals, the choice of
which state to model was dictated by practical aspects such as availability of sorption
reactions and by subjective assessment of the appropriate oxidation state. The
oxidation states modeled were Sb(V) (there were no sorption reactions available for
Sb(lll)), Mo(VI) (molybdate seems the most relevant form from literature reports),
thallium (I) (this form is more frequently cited in the literature as having environmental
implications), and V(V) (vanadate; sorption reactions were not available for other
forms).
2.2 GROUND-WATER COMPOSITION
The extent of metal sorption in a ground-water system is dependent upon the
chemical characteristics of the pore water solution and the interactions between all
solutes and the sorbing sites present on the exposed surfaces of the soil and aquifer
matrix material. In EPACMTP, partition coefficients were estimated separately for two
ground-water compositional types, one with composition representative of a carbonate-
terrain system and one representative of a non-carbonate system. The two ground-
water compositional types are correlated with the hydrogeologic environment parameter
in EPACMTP. In EPACMTP, this parameter may take on one of thirteen values, each
indicative of a particular ground-water type (see Table B.1). Issues of practicality limit
to just two the number of ground-water types for which separate partition coefficients
can be estimated. The broadest division that may be made of the thirteen ground-water
types in EPACMTP is carbonate and non-carbonate. Thus, these are the two broad
types for which coefficients were estimated. The carbonate type corresponds to the
"solution limestone" hydrogeologic environment setting in EPACMTP (hydrogeologic
environment parameter = 12). The other twelve possible hydrogeologic settings in
EPACMTP are represented by the non-carbonate ground-water type.
B-4
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
Table B.1 Settings For The Hydrogeologic Environment Parameter In
EPACMTP
Hydrogeologic
Environment Parameter
1
2
3
4
5
6
7
8
9
10
11
12
13
Environment (Ground-Water Type) Represented
Metamorphic and Igneous
Bedded Sedimentary Rock
Till Over Sedimentary Rock
Sand and Gravel
Alluvial Basins Valleys and Fans
River Valleys and Floodplains with Overbank Deposits
River Valleys and Floodplains without Overbank Deposit
Outwash
Till and Till Over Outwash
Unconsolidated and Semi-consolidated Shallow Aquifers
Coastal Beaches
Solution Limestone
Others (unclassified hydrogeologic environments)
For both ground-water types, we selected from the literature a representative,
charge-balanced ground-water chemistry specified in terms of major ion concentrations
and natural pH. The carbonate system was represented by a well sample reported for
a limestone aquifer (Freeze and Cherry, 1979). This ground water had a natural pH of
7.5 and was saturated with respect to calcite. The non-carbonate system was
represented by a sample reported from an unconsolidated sand and gravel aquifer with
a natural pH of 7.4 (White et al., 1963). An unconsolidated sand and gravel aquifer
was selected to represent the non-carbonate compositional type because it is the most
frequently occurring of the twelve (non-carbonate) hydrogeologic environments in
EPACMTP. The composition of both the carbonate and non-carbonate representative
ground-water samples is shown in Table B.2. These compositions were used in
MINTEQA2 to estimate partition coefficients for carbonate and non-carbonate ground-
water types. When EPACMTP is used in site-specific or monte carlo mode, the choice
of the hydrogeologic environment by the user (or the monte carlo routine) dictates the
set of partition coefficients (carbonate or non-carbonate) that should be accessed.
B-5
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
Table B.2 Composition Of Representative Ground Waters
Constituent Chemical
Ca
Mg
S04
HCO3
Na
Cl
K
N03
F
SiO2
PH
Temp
Other
Concentrations (mg/L)
Carbonate Ground
water
55
28
20
265
3.1
10
1.5
—
—
—
7.5
18C
Equilibrium with calcite
Non-carbonate Ground
water
49
13
27
384
105
34
3.0
7.8
0.3
21
7.4
14C
—
2.3 MODEL ADSORBENTS
Two types of adsorbents were represented in the MINTEQA2 equilibrium
modeling: ferric oxide and paniculate organic matter. Ferric oxides (and hydroxides)
and paniculate organic matter are among the most important sorbents in natural
systems. The former may be present as amorphous substances or crystalline minerals
such as hematite, goethite, or ferrihydrite dispersed in soil as discrete particles or as
coatings on particles of other materials. In recent years, databases of equilibrium
sorption reactions for hydrous ferric oxide and goethite have been compiled from
studies described in the literature (Dzombak and Morel, 1990; Mathur, 1995). Both of
the databases cited were designed for use with the MIT Two-Layer sorption model, also
called the diffuse-layer model (DLM; Dzombak and Morel, 1990).
Owing to the complexity and variability of natural organic substances, the
science of modeling surface reactions on paniculate organic matter is less advanced
than for sorption onto hydrous metal oxides. The modeling described here assumes
that reactions on POM are analogous to those on dissolved organic matter (DOM); a
DOM model was adapted for the POM calculation. This model, the Gaussian
distribution model (Dobbs et. al., 1989), assumes that organic matter is a complex
mixture of substances exhibiting highly variable binding affinities for metals. Reactions
are represented like conventional pure substance reactions except that the usual single
equilibrium constant is replaced by a distribution of constants (log K values). The
distribution of log K is assumed to be Gaussian in shape. This model is also supplied
with a database of reactions, including acid-base and major ion reactions, each with its
mean log K for depicting the Gaussian distribution.
B-6
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
When included in equilibrium models, these databases of sorption reactions
provide a means of including competition for sorption sites among major ground-water
ions such as Ca, Mg, and SO4 and contaminant metal constituents. More importantly,
by including in equilibrium calculations the acid-base reactions for these surfaces, the
dependence of trace metal sorption on pH can be reflected in the model.
2.3.1 Goethite Sorbent
Mineralogically, we assumed the ferric oxide sorbent to be goethite (a-FeOOH).
Goethite is a common form of ferric oxide in soils. The database of sorption reactions
for goethite reported by Mathur (1995) was used with the diffuse-layer sorption model
in MINTEQA2 to represent the interactions of protons, major ions, and contaminant
metals with the ferric oxide surface (hereafter referred to as FeOx for brevity).
The concentration of sorption sites used in the MINTEQA2 model runs was
based on a measurement of ferric iron extractable from soil samples using
hydroxylamine hydrochloride as reported in EPRI(1986). This method of Fe extraction
is intended to provide a measure of the exposed ferric oxide present as mineral
coatings and discrete particles and available for surface reactions with solutes in the
associated pore water. The variability in ferric oxide sorbent concentration represented
by the variability in extractable Fe from these samples was included in the modeling by
selecting low, medium and high extractable Fe concentrations corresponding to the 17th,
50th and 83rd percentiles of the sample measurements. The extractable Fe weight
percentages used in the modeling are shown in Table B.3.
Table B.3 Concentration Levels For Goethite Sorbent
Concentration Level
Weight Percent
Fe (extractable)
FeOOH Sorbent
Concentration (g/L)
Unsaturated zone
Low
Medium
High
0.0182
0.0729
0.1190
1.325
5.309
8.667
Saturated zone
Low
Medium
High
0.0182
0.0729
0.1190
1.032
4.136
6.751
Although the same distribution of extractable Fe sorbent was used in modeling
the saturated and unsaturated zones, the actual concentration of sorbing sites
corresponding to the low, medium, and high FeOx settings in MINTEQA2 was different
in the two zones because the assumed ratio of soil mass to solution volume (the phase
ratio) was different. For both zones, the phase ratio was calculated as the mean soil
bulk density divided by the mean water content (product of mean porosity and mean
water saturation). In EPACMTP, the mean soil bulk density and mean porosity are
B-7
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
1.6 kg/L and 45 percent, respectively. The mean water saturation in the unsaturated
zone is 77.7 percent. The water saturation in the saturated zone is, of course, 100
percent. Thus, the phase ratio for the unsaturated zone is 4.57 kg/L and for the
saturated zone is 3.56 kg/L. We used these values and the molar mass ratio of
goethite to Fe to convert the weight percent extractable Fe to the mass of goethite
appropriate for one liter of pore water solution (see Table B.3).
The specific surface area and site density used in the diffuse-layer adsorption
model were as prescribed by Mathur(1995) for goethite. These values along with the
molar concentration of FeOx sorbing sites are shown in Table B.4. The complete
database of goethite sorption reactions used in MINTEQA2, including acid-base surf ace
reactions and reactions for major ions, is shown in Table B.5. The reactions shown in
Table B.5 have been reformulated for use in MINTEQA2. The reformulation step is
necessary in order to present the reaction to MINTEQA2 in a manner consistent with
its database conventions and its predetermined set of reactants (components). The
MINTEQA2 conventions include the requirement that all reactions be written as
formation reactions. In some cases, the reformulation may have involved adding
ancillary reactions to those presented by Mathur. The addition of ancillary reactions is
necessary if the original reaction is not written in terms of MINTEQA2 components. All
ancillary reactions used to reformulate the Mathur goethite reactions were obtained
directly from the MINTEQA2 (v4.02) thermodynamic database.
Table B.4 Model Parameters For The Goethite Sorbent
Parameter
Specific surface area (m2/g)
Site density (moles of sites per mole
Fe)
Model Value
60
0.018
Unsaturated zone: Site concentration (mol/L)
Low
Medium
High
2.680x1 0'4
1 .074x1 0'3
1. 753x1 0'3
Saturated zone: Site concentration (mol/L)
Low
Medium
High
2.087x1 0'4
8.365x1 0'4
1. 365x1 0'3
B-8
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
Table B.5 Goethite Sorption Reactions Used In MINTEQA2
Goethite Sorption Reaction
^FeOH2+ ^ ^FeOH° + H+
^FeOH° ^ ^FeO" + H+
^FeOH° + Ca2+ ^ ^FeOCa+ + H+
^FeOH° + Ca2+ ^ ^FeOHCa2+
^FeOH° + Ca2+ + IT ^ ^FeOCa+ + H2O
= FeOH° + Mg2+ ^ =FeOMg+ + H+
= FeOH° + Mg2+ ^ =FeOHMg2+
= FeOH° + Ba2+ ^ =FeOBa+ + IT
^FeOH° + Ba2+ ^ ^FeOHBa2+
^FeOH° + Cu2+ ^ ^FeOCif + H+
— r^ f**f~*\\ — |0 _i_ f"* 1 1"" i- — Fo^^l — 1 f"* 1 1""
= rcvy i i ~r v^u "* — = re Vy I I v^u
^FeOH° + Cd2+ ^ ^FeOCd+ + H+
= FeOH° + Cd2+ ^ =FeOHCd2+
^FeOH° + Zn2+ ^ ^FeOZn+ + IT
= FeOH° + Zn2+ ^ =FeOHZn2+
= FeOH° + Pb2+ ^ =FeOPb+ + H+
= FeOH° + Pb2+ ^ =FeOHPb2+
^FeOH° + Ni2+ ^ ^FeONi+ + H+
^FeOH° + Ni2+ ^ ^FeOHNi2+
^FeOH° + Co2+ ^ ^FeOCo+ + IT
^FeOH° + Co2+ ^ ^FeOHCo2+
^FeOH° + Hg(OH)2° ^ ^FeOHgOH0 + H2O
^FeOH° + Hg(OH)2° + H+ ^ ^FeOHg+ + 2 H2O
^FeOH° + Hg(OH)2° + 2H+ ^ ^FeOHHg2+
+ 2H2O
^FeOH° + Hg(OH)2° + H+ + CI" ^ ^FeOHgCI0
+ 2H2O
^FeOH° + Ag+ ^ ^FeOAg + IT
= FeOH° + Ag+ ^ =FeOHAg+
= FeOH° + Mn2+ ^ =FeOMn+ + H+
= FeOH° + Mn2+ ^ =FeOHMn2+
^FeOH° + Be2+ ^ ^FeOBe+ + H+
^FeOH° + Be2+ ^ ^FeOHBe2+
^FeOH° + Tl+ ^ ^FeOTI0 + IT
^FeOH° + Tl+ ^ ^FeOHTI+
^FeOH° + Cr(OH)2+ ^ ^FeOCrOH+ + H2O
Intrinsic
Equilibrium
Constant
log Ka1
log Ka2
log K,
log K2
log K3
log K,
log K2
log K,
log K2
log K,
log K2
log K,
log K2
log K,
log K2
log K,
log K2
log K,
log K2
log K,
log K2
log K0
log K,
log K2
log K4
log K,
log K2
log K,
log K2
log K,
log K2
log K,
log K2
log K,
6.93
-9.65
-6.48
3.98
12.26
-3.02
5.24
-5.62
3.43
1.39
8.92
-1.96
6.28
-0.96
7.50
0.44
8.25
-1.96
6.38
-0.79
7.28
2.86
10.03
18.58
13.51
-4.11
4.74
-2.66
5.99
2.69
10.61
-5.37
3.66
8.07
B-9
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
Table B.5 Goethite Sorption Reactions Used In MINTEQA2 (continued)
Goethite
^FeOH° + Cr(OH)2+
^FeOH° + H3AsO3°
^FeOH° + H3AsO4°
^FeOH° + H3AsO4°
^FeOH° + H3AsO4°
^FeOH° + VO2+ +
^FeOH° + VO2+ +
^FeOH° + VO2+ +
^FeOH° + Sb(OH)6-
^FeOH° + Sb(OH)6'
^FeOH° + SO42' +
^FeOH° + SO42' +
^FeOH° + SO42" ^
^FeOH° + HSeCV +
^FeOH° + HSeO3"^
^FeOH° + HSeCV^
^FeOH° + SeO42" +
^FeOH° + SeO42' +
^FeOH° + CrO42' +
^FeOH° + CrO42' +
^FeOH° + CrO42" ^
^FeOH° + MoO42' +
^FeOH° + MoO42" +
Sorption Reaction
+ IT ^ ^FeOHCrOH+2 + H2O
^ ^FeH2AsO3° + H2O
^ ^FeH2AsO4° + H2O
^ ^FeHAsO; + H+ + H2O
^ ^FeOHAsO/- + SIT
H2O ^ ^FeH2VO4° + IT
H2O ^ ^FeHVO; + 2H+
2H2O ^ ^FeOHVO43- + 4H+
+ H+ ^ ^FeOH2Sb(OH)6°
^ ^FeOHSb(OH)6-
2H+ ^ ^FeHSO4° + H2O
IT ^ ^FeSO4" + H2O
^FeOSO43" + H+
H+ C/-\l IO/-\/"\ 0 1 1 f~\
** =rerlo6U3 + n2vj
= FeSeO3" + H2O
^FeOSeO33- + 2H+
2H+ ^ ^FeHSeO4°+ H2O
H+ ^ ^FeSeO; + H2O
2H+ ^ ^FeHCrO4° + H2O
H+ ^ ^FeCrO; + H2O
^FeOHCrO/'
2H+ ^ ^FeHMoO4° + H2O
IT ^ ^FeMoO; + H2O
^FeOH° + F- + H+ ^ ^FeOH2F°
^FeOH° + F" ^ ^FeOHF
Intrinsic
Equilibrium
Constant
log K2 = 1 6.07
log K, = 4.33
log K, = 6.87
log K2 = -0.89
log K4 = -11 .09
log K, = 2.35
log K2 = -5.91
logK4 = -17.53
log K, = 11 .94
log K2 = 5.76
logK, = 12.89
log K2 = 6.74
log K4 = -6.26
log K, = 3.25
log K2 = 2.09
logK4 = -14.25
log K, = 11 .65
log K2 = 6.54
logK, = 17.11
logK2 = 11.17
log K3 = 4.05
logK, = 14.65
logK2 = 8.18
log K, = 9.20
log K2 = 1 .59
2.3.2 Particulate Organic Matter Sorbent
We obtained the concentration of the second adsorbent, paniculate organic
matter, from organic matter distributions already present in EPACMTP. EPACMTP
includes frequency distributions for organic matter for three soil types in the unsaturated
zone: silty clay loam, sandy loam, and silty loam. The silty loam soil type is
intermediate in weight percent organic matter in comparison with the other two and is
the most frequently occurring soil type. Therefore, low, medium, and high POM content
levels for the MINTEQA2 modeling in the unsaturated zone were established as the 7.5,
50, and 92.5 percentiles of the silty loam organic matter distribution. In the saturated
zone, the EPACMTP distribution of organic matter is identical to that for the sandy loam
B-10
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
soil type of the unsaturated zone. Low, medium, and high POM content levels in
MINTEQA2 modeling of the saturated zone were established as the 7.5, 50, and 92.5
percentile levels, respectively, of this distribution.
As was the case for the goethite sorbent, the concentration of POM included in
the MINTEQA2 modeling was determined from the low, medium, and high content
levels (expressed in weight percent POM) and the mass of soil appropriate for one liter
of pore water solution (see section 2.3.1). Thus, phase ratios of 4.57 kg/L in the
unsaturated zone and 3.56 kg/L in the saturated zone were used to compute the POM
concentration for MINTEQA2 model runs.
We obtained a dissolved organic carbon (DOC) distribution for the saturated
zone from the U.S. EPA STORE! database. This distribution is based on 1343
ground-water samples and is approximated by a log normal distribution with a median
loge DOC of 1.974 (corresponding to 7.2 mg C per liter) and loge standard deviation of
1.092. Assuming DOM is approximately 50 percent organic carbon, the DOC values
are multiplied by two to approximate DOM concentrations. The MINTEQA2 modeling
employed low, medium and high concentrations for DOM corresponding to the 7.5,
50.0, and 92.5 percentiles, respectively, of this approximated DOM distribution. An
important point to note is that POM and DOM were not treated as independent variables
in the MINTEQA2 modeling: the high DOM value was associated with the high POM
value, the medium DOM with the medium POM, etc.
Because no directly measured data were available for describing the variation
in DOM concentration in the unsaturated zone, we assumed that high, medium, and low
DOM concentrations reflected a constant ratio of POM content (in weight percent) to
DOM concentration. The constant ratio was arbitrarily chosen as the ratio of the
median DOM (mg/L) from the saturated zone distribution to the median value of POM
(weight percent) from the saturated zone distribution. This ratio, 194.6, was applied to
the low, medium, and high weight percent POM values of the unsaturated zone to
obtain DOM concentrations at the low, medium, and high levels. The weight percent
POM and concentration (mg/L) of both POM and DOM is shown in Table B.6 for all
three concentration levels in both zones.
For both POM and DOM, we assumed a site density of 1.2 x 10"6 moles of sites per mg
organic matter. The site concentrations for organic matter in both zones are listed in
Table B.7.
B-11
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
Table B.6 POM And DOM Concentration Levels
POM wt%
POM
Concentration
(mg/L)
DOM Concentration
(mg/L)
Unsaturated zone
Low
Medium
High
0.034
0.105
0.325
1553.8
4798.5
14852.5
6.6
20.4
63.20
Saturated zone
Low
Medium
High
0.020
0.074
0.275
712.0
2634.4
9790.0
3.00
14.40
69.38
Table B.7 Site Concentrations For POM And DOM Components In MINTEQA2
POM Site
Concentration
(mol/L)
DOM Site
Concentration
(mol/L)
Unsaturated zone
Low
Medium
High
1.865x10-3
5.758 x10'3
1.782x10'2
7.896 x1 0'6
2.439 x10'5
7.548 x1 0'5
Saturated zone
Low
Medium
High
8.544 x10'4
3.161 x10'3
1.175x10'2
3.600 x10'6
1 .728 x1 0'5
8.326 x10'5
We used a specialized sub-model within MINTEQA2 for calculations involving
the POM and DOM. This sub-model, called the Gaussian distribution model, assumes
that natural organic matter is a mixture of various functional groups having a mean log
K for binding protons and metals, and a standard deviation in log K (Dobbs et al.,
1989). This is in contrast to all other reactants in MINTEQA2 which are implicitly
treated as pure substances with a single equilibrium constant for a particular metal. A
database of DOM reactions proposed by Susetyo et al. (1991) for the metals Ba, Cd,
Cr(lll), Cu, Pb, Ni, and Zn and for protons and various other MINTEQA2 components
is included with version 4.02 of the model. Adsorption of metals onto POM was
included in the model calculations by assuming that the reactions were identical to
those for metal complexation with DOM. Table B.8 shows Gaussian organic matter
reactions used in MINTEQA2 for this work. Although the Gaussian model was
B-12
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
proposed for metal-DOM reactions, we used it here to account for metal-POM reactions
as well. The only difference between the method of calculation for metal-DOM and
metal-POM species in MINTEQA2 was that POM species were excluded from
contributing to the ionic strength.
For the metals Ag, Co, Hg, and Tl, it was necessary to estimate the mean log
K for DOM and POM binding for use in MINTEQA2. The mean log K values for Ag, Co,
and Tl were derived from a linear free-energy relationship based upon to known mean
log K values for several metals, their first hydrolysis constants, and their log K values
for complexation with acetate. For Hg, the mean log K was estimated from a linear
regression based on binding constants for humic and fulvic acid as given by Tipping
(1994).
Table B.8 POM And DOM Reactions Included In MINTEQA2 Modeling
Organic Matter (OM) Reaction
OM + H+ ^OM-H
OM + Ca2+ ^OM-Ca
OM + Mg2+ ^OM-Mg
OM + Ba2+ ^OM-Ba
OM + Be2+ ^OM-Be
OM + Cd2+ ^OM-Cd
OM + Cr(OH)2+ + 2H+ ^ OM-Cr + 2H2O
OM + Cu2+ ^OM-Cu
OM + Ni2+ ^OM-Ni
OM + Pb2+ ^OM-Pb
OM + Zn2+ ^OM-Zn
OM + Hg(OH)2° + 2H+ ^OM-Hg+2H2O
OM + Co2+ ^OM-Co
OM + Ag+ ^OM-Ag
OM + Tl+ ^OM-TI
OM + Mn2+ ^OM-Mn
Mean
logK
3.87
2.9
1.9
3.1
3.5
3.3
15.22
4.9
3.3
5.2
3.5
15.2
3.3
2.0
1.0
3.0
Standard
Deviation
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
Species
Charge
-1.8
-0.8
-0.8
-0.8
-0.8
-0.8
0.2
-0.8
-0.8
-0.8
-0.8
-0.8
-0.8
-1.8
-1.8
-0.8
2.4 LEACHATE ORGANIC MATTER
In addition to the metal contaminants, the leachate exiting a landfill may contain
elevated concentrations of leachate organic matter. This organic matter may consist
of various compounds including organic acids that represent primary disposed waste
or that result from the breakdown of more complex organic substances. Many organic
acids found in landfill leachate have significant metal-complexing capacity that may
influence metal mobility. In an effort to incorporate in the Kd modeling the solubilizing
effect of organic acids, we included three representative monoprotic acids as
B-13
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
components. Data presented by Gintautas et al. (1993) were used to select and
quantify the three representative organic acids. Gintautas examined leachates from six
landfills from across the U.S. Their analyses indicated the presence of over 30 different
acids-most were carboxylic. The three acids chosen to represent the complex mixture
of leachate acids in the MINTEQA2 modeling were acetic acid, propionic acid, and
butyric acid. These were selected based on structure-activity relationships, comparison
of equilibrium constants, and relative concentrations in the leachates analyzed by
Gintautas.
In the MINTEQA2 modeling, low, medium, and high concentration levels for the
representative acids were established based on the lowest, the average, and the
highest measured TOG among the six landfill leachates. The same set of three acids
was used in both the unsaturated and saturated zones. In the latter, their
concentrations were one-seventh of their unsaturated zone concentrations. This
reduction in the leachate acid concentration was applied to account in a rudimentary
way for the effects of dispersion and diffusion in the mixing zone. The factor of one-
seventh resulted from flow model tests to estimate an "average" dilution factor in the
mixing zone. Table B.9 gives the low, medium, and high concentrations used in the
MINTEQA2 modeling for each of the three acids in each zone.
The MINTEQA2 thermodynamic database includes complexation reactions
between each of the three representative acids and many of the contaminant metals of
interest. Acid-base and major ion reactions are also included. Some metals, especially
those that behave as anions in aqueous solution (e.g., arsenite, arsenate, chromate,
etc.) do not complex with these acids.
Table B.9 Model Concentrations Of Representative Leachate Acids
Concentration Level
Acetic acid
(mci/L)
Propionic acid
(mci/L)
Butyric acid
(mg/L)
Unsaturated zone
Low
Medium
High
24.80
111.00
274.60
14.61
64.30
158.60
15.68
67.94
169.00
Saturated zone
Low
Medium
High
3.54
15.86
39.23
2.09
9.19
22.66
2.24
9.71
24.14
B-14
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
2.5 MINTEQA2 MODELING PROCEDURE
The MINTEQA2 modeling was conducted separately for each of the twenty-two
contaminant metals. For each metal, the modeling was performed separately for each
zone (unsaturated and saturated) for each of the two ground waters. Thus, results
were produced in four main categories: the carbonate ground-water unsaturated zone,
the carbonate ground-water saturated zone; the non-carbonate ground-water
unsaturated zone, and the non-carbonate ground-water saturated zone. Within each
of these four categories, we followed a similar modeling procedure. The modeling
procedure consisted of three steps, each involving execution of the MINTEQA2 model.
First, the sorbents were pre-equilibrated with the ground water at the natural ground-
water pH. Second, the pre-equilibrated ground-water sorbent systems were titrated to
different pH's of interest. Finally, leachate organic acids and the contaminant metal
were added to the pre-equilibrated, pH-adjusted systems. In this last step, the metal
salt was added to each system at a series of forty-four total concentrations as in a
titration and the model computed the equilibrium distribution at each titration point to
produce an isotherm.
2.5.1 Pre-equilibration With Sorbents
The goethite and POM sorbents were pre-equilibrated with the ground water at
all nine combinations of their concentration levels. Because the sorbents adsorb some
of the non-contaminant ions present as ground-water constituents (calcium,
magnesium, sulfate, fluoride), we assume the representative compositions used for
both the carbonate and non-carbonate ground waters reflect dissolved concentrations
at equilibrium with an unknown sorbed concentration. The purpose of the pre-
equilibration step is to estimate this unknown sorbed concentration so that it may be
included in subsequent model runs. The method of discovering the sorbed totals for
each of the ground-water constituents that undergoes sorption was trial and error.
Specifically, MINTEQA2 was executed repeatedly with adjusted total concentrations of
these sorbing constituents until the equilibrium dissolved concentration for each was
equal to the measured dissolved concentrations reported for the ground water. This
trial and error pre-equilibration method was performed separately for each of nine
possible combinations of the FeOx and POM sorbent concentrations (e.g., low FeOx,
low POM; low FeOx, medium POM;from Table B.4).
The pre-equilibration step was conducted at the natural pH of each ground
water, and calcite was imposed as an equilibrium mineral for the carbonate ground-
water type. Small additions of inert ions (Na+ or NO3") were added to maintain charge
balance.
2.5.2 Titrating Systems To New pH Values
The nine pre-equilibrated systems were titrated to target pH's that span the pH
range commonly observed for that ground-water type. Rather than imposing target
pH's as equilibrium constraints in the model, we used acids and bases to titrate to the
pH targets. The titrants for pH adjustment were NaOH to raise the pH and HNO3 to
lower the pH. For the carbonate ground water, the pH was assumed to range from 7.0
B-15
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
to 8.0. Since the natural pH of the carbonate ground water was 7.5, the acid and base
were used to lower and raise the pH to 7.0 and 8.0, respectively, resulting in three pH
values for this ground water. Since this was done for each of the nine pre-equilibrated
systems, the outcome of this titration step was twenty-seven variants of the carbonate
ground-water system exhibiting various concentration levels of the sorbent and various
pH values. Equilibrium with calcite was maintained in all of these carbonate systems.
For the non-carbonate ground water, the pH of interest was assumed to span
the range 4.5 to 8.2. Each of the nine pre-equilibrated non-carbonate systems was
titrated to nine target pH's within this range: 4.5,5.1, 5.6,6.0, 6.3,6.6, 6.9,7.4, and 8.2.
Since the natural pH of the non-carbonate ground water was 7.4, the base was used
only to titrate to pH 8.2. The lower pH's were attained by titrating with the acid. The
outcome of the titration step for the non-carbonate ground water was eighty-one
variants of the non-carbonate ground-water system exhibiting various concentration
levels of the sorbent and various pH values.
2.5.3 Addition Of Leachate Acids And Contaminant Metal
Each of the pre-equilibrated, pH-adjusted systems were equilibrated with the
three concentration levels of leachate organic acids (see Table B.9). As before, the
equilibrium pH was not imposed as a constraint in MINTEQA2, so the addition of the
leachate acid impacted the calculated equilibrium pH. Because there were three
concentration levels for the leachate organic acids, this step resulted in 81 leachate-
ground-water systems for each zone (unsaturated and saturated) for the carbonate
ground water and 243 leachate-ground-water systems for each zone for the non-
carbonate ground water.
The contaminant metal was added in the same step as the leachate organic acids. The
metal was added as a metal salt at a series of forty-four total concentrations spanning
the range 0.001 mg/L to 10,000 mg/L of metal. The choice of chemical species by
which the metal was introduced was predicated on the desire to maintain charge
balance and to avoid species that would exert a great influence on the equilibrium pH.
In some cases, we introduced a fictitious substance to accomplish these goals. The
equilibrium distribution was calculated at each of the forty-four total metal
concentrations to produce an isotherm of sorbed metal versus metal concentration.
B-16
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
3.0 RESULTS
As shown in Figure B.1, MINTEQA2 computes the equilibrium distribution of
metal among three categories: dissolved, sorbed, and precipitated. The concentration
in the first two of these categories along with the corresponding total metal
concentration define the non-linear isotherm. All three concentrations (dissolved,
sorbed, and precipitated) are made available for use in EPACMTP, but the precipitated
concentration is not used. The ratio of the equilibrium sorbed and dissolved
concentrations recorded in the isotherm is the dimensionless Kd. For the sorbed
fraction, the concentration recorded in the isotherm is the amount of metal sorbed from
one liter of solution. Of course, this amount is also sorbed onto the mass of soil with
which one liter was equilibrated. This mass is the phase ratio: 4.57 kg/L for the
unsaturated zone and 3.56 kg/L for the saturated zone. The Kd in units of L/kg is thus
computed by normalizing the dimensionless Kd by the appropriate phase ratio.
For each metal, the modeling resulted in 243 isotherms for the non-carbonate
ground water for the unsaturated zone, and 81 isotherms for the carbonate ground
water for the unsaturated zone. We produced a like number of isotherms for each
ground water for the saturated zone. Each isotherm corresponds to particular
concentration levels of FeOx and POM sorbents, pH, and leachate organic matter
concentration. In monte carlo or site-specific mode, EPACMTP selects the appropriate
isotherm based on the conditions being modeled. Isotherms were produced for Ag,
As(lll), As(V), Ba, Be, Cd, Co, Cr(lll), Cr(VI), Cu, F, Hg, Mn(ll), Mo(V), Ni, Pb, Sb(V),
Se(IV), Se(VI), Tl(l), V(V), and Zn.
3.1 EXAMPLE ISOTHERMS
Example isotherms for Cr(VI) are shown in Figure B.2. This figure shows Kd
versus total Cr(VI) concentration for the non-carbonate ground water saturated zone
at various pH values. The isotherms plotted are for the medium concentration level of
FeOx and POM sorbents and the low concentration level of leachate organic matter.
Because chromate behaves as an anion in ground water, its adsorption is enhanced at
low pH relative to high pH. This behavior is reversed for metals that behave as cations.
Figure B.3 shows the impact of FeOx concentration level on the Kd values of
lead. As expected, sorption is enhanced at the higher FeOx concentrations resulting
in larger Kd values. The example shown is for the unsaturated zone of the carbonate
ground water with the low concentration levels of POM and leachate organic acids. The
pH corresponds to the lowest setting for the carbonate systems: 7.0.
The impact of varying the POM concentration level differs among the various
metals. The effect of POM concentration level also depends on the pH. The variable
impact of POM is due to two factors: the absence of organic matter reactions for anionic
metals and the concurrent influence of DOM for those metals for which organic matter
reactions are included. In the MINTEQA2 modeling procedure we used, increasing the
POM sorbent concentration is always accompanied by a proportional increase in the
DOM concentration. The overall impact on the amount of metal sorbed depends on the
B-17
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
relative competition among all constituents in the systems for these two substances.
The "winner" of this relative competition (POM or DOM) shifts with pH because both
substances undergo acid-base reactions. Figure B.4 shows the impact of varying the
POM/DOM concentration level on lead sorption for the non-carbonate ground water
unsaturated zone with medium FeOx concentration level and low leachate organic
matter concentration level at pH 6.3.
The influence of the leachate organic matter concentration level is illustrated in
Figure B.5 for copper sorption. The LOM level is represented in the model by particular
concentrations of three representative leachate organic acids. The acids exert two
modes of influence on metal sorption: (1) they lower the pH, reducing sorption of
cations and enhancing sorption of anions; (2) for those metals that complex these
acids, metal sorption is reduced through competition. The latter effect is generally
restricted to metals that behave as cations. The results shown in Figure B.5 correspond
to high concentration levels of FeOx and POM sorbents in the unsaturated zone for the
carbonate ground water. The pH is 7.0.
150
O)
100
O)
o
50
\\
pH4.5
pH 6.3
pH 8.2
-4
-202
log Total Cr (VI) Cone (mg/L)
Figure B.2 Cr(VI) Isotherms Illustrating Influence of pH.
B-18
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
40
0)30
^20
10
Low
Med FeOx
High
-4
-202
log Total Pb Cone (mg/L)
Figure B.3 Pb Isotherms Illustrating Influence of FeOx Sorbent Concentration.
50
§ 4°
d,30 ^
§ 20
O)
o 10
Low POM
Med POM
High POM
-4
-202
log Total Pb Cone (mg/L)
Figure B.4 Pb Isotherms Illustrating Influence of POM/DOM Concentration.
B-19
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
150
O)
:f
T3
O)
O
100
50
-4
•Low LOM
Med LOM
High LOM
-202
log Total Cu Cone (mg/L)
Figure B.5 Cu Isotherms Illustrating Influence of LOM Concentration.
B-20
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
4.0 ASSUMPTIONS AND LIMITATIONS
There are many assumptions inherent in the use of a speciation model to
estimate partition coefficients. Some of these must be acknowledged to result in
limitations on the utility of the model results. Undoubtedly, the results are better for
some metals than for others. Various modeling assumptions and limitations we used
are presented below. These are organized as those resulting from the manner in which
the ground-water composition, the sorbents, and the leachate were characterized, and
certain broader, more general issues. The discussion is limited to pointing out each
assumption or limitation. Although the direction of possible error in the estimated Kd
values is apparent from some of these limitations, it would seem to be impossible to
quantify the uncertainty in the estimated Kd values.
4.1 GROUND-WATER CHARACTERIZATION ISSUES
The categorization of all ground waters into two types, carbonate and non-
carbonate, is quite broad. The non-carbonate category is especially broad, and
sorption behavior among different ground-water compositions that might fall into
this category could be quite variable. We did not account for this variability in
the current approach.
Although the pre-equilibration step is helpful in more realistically establishing
appropriate major ion concentrations, it is somewhat artificial in the sense that
sorbents are not correlated with ground water. Both the FeOx and POM
sorbents were represented as general concentration distributions; the
concentration levels used do not correlate specifically to the ground-water
compositions used.
Both ground waters were artificially adjusted to different pH's of interest by
titrating with an acid or base. The degree to which this procedure can result in
model ground-water compositions that adequately represent true variability in
factors that impact Kd is unknown.
4.2 SORBENT CHARACTERIZATION ISSUES
Only two sorbents are represented in the model systems. Other sorbents are
important in some circumstances including clays, hydrous aluminum and
manganese oxides, calcite, and silica. Failure to include all potential sorbents
could result in underestimation of sorption.
The ferric oxide was accounted in the modeling as goethite. Other ferric oxides
may be important in ground water, including hydrous ferric oxide (HFO). HFO
has a higher specific surface area and greater reactivity for some metals than
does goethite. The degree of sorption may be underestimated for some metals
in systems where HFO is the dominant form of ferric oxide. Also, equilibrium
constants for adsorption onto goethite were unavailable for some metals;
estimates were used.
B-21
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
The data used to quantify the FeOx and POM sorbents (and the DOM) is
sparse. The degree to which the true variability in concentration levels of these
sorbents has been captured in the modeling is unknown.
There is no provision in the modeling to account for occlusion of sorbents. Both
ferric oxide and organic matter may form coatings over other surfaces. Failure
to account for occlusion could result in overestimating the available sorption
sites.
The ferric oxide (goethite) sorbent is included in all model runs. This implies
that it is ubiquitous. However, there are natural ground-water conditions that
preclude the formation of ferric oxide precipitates. As illustrated in Figure B.6,
goethite is not the stable iron solid phase at conditions of low pH and low Eh.
The approximate pH-Eh window of applicability for the model results is outlined
by dashes in this figure. The selection of specific pH targets limits the pH range
(4.5 to 8.2). But no explicit Eh was defined in the model (wavy lines at top and
bottom of window in Figure B.6). The "implied" Eh minimum could be
considered as the level where ferric oxide ceases to be the stable iron phase.
Within the pH range of interest, this implies that the lower left corner of the
window shown in Figure B.6 is inconsistent with the use of goethite as a sorbing
phase. Including the goethite sorbent where it cannot exist could obviously lead
to overestimating sorption. The omission of the stable iron phases siderite and
pyrite as model sorbents serves to compensate for this flaw, although the extent
of this compensation is unknown. The main point of the diagram is not to point
out the stability fields of specific iron minerals but to show the applicability
window for our modeling (framed by pH and Eh) with reference to the general
picture of iron sulfide, carbonate, and hydroxide (or oxide) minerals.
The Gaussian model for estimating metal interactions with organic matter was
developed for dissolved organic matter. It has not been tested for estimating
the degree of metal sorption onto POM. Also, mean log K values for some
metals have not been measured; estimates were used.
4.3 LEACHATE CHARACTERIZATION ISSUES
The concentration levels for leachate organic matter were based on a limited
sampling from six municipal landfills. Municipal landfills may have leachate
organic content that is significantly different from that of hazardous waste units.
Hazardous waste leachates may show more variability in total organic carbon
concentration and in the nature of the organic species present.
Other leachate constituents may be present at elevated concentrations, but
these are not accounted for. Some of these (e.g., Ca, Mg, SO4, Cl, etc.) may
reduce the amount of metal sorption by competing for adsorption sites
(especially Ca) or by complexing metals so that a greater fraction is retained in
solution (especially SO4 and Cl). Failure to include these effects could result in
overestimating sorption of some metals.
B-22
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
Leachate from highly alkaline wastes was not included in the modeling. Highly
alkaline leachates may result in elevation of the ground-water pH above the
upper bound for which isotherms have been computed. Sorption tends to
increase with pH for many metals up to about pH 8 to 9. Above this level,
formation of metal hydroxy solution species may inhibit sorption for some
metals.
The metal was introduced as a metal salt. The metal species was chosen to
avoid impact on the pH, but some pH effect is unavoidable. Arbitrary changes
in pH due to the choice of metal species may have induced undesired changes
in Kd, especially at high total metal concentrations.
Methylated forms of metal were not accounted for in this modeling. Mercury
and arsenic are known to undergo methylation in the environment.
4.4 OTHER ISSUES
The system redox potential was not explicitly defined in the modeling. All
species that might undergo oxidation-reduction reactions were constrained to
remain in the form in which they were entered in the model. This restriction
applied to major ions such as sulfate and to all trace metals. The impact on Kd
is unknown, but is expected to be metal-specific.
All contaminant metals were introduced separately and individually in the
modeling. The possible simultaneous presence of multiple metals is
unaccounted for. The impact on Kd is not expected to be great except at high
metal concentrations were competition for sorption sites may result in less
sorption for some metals than suggested by this modeling.
B-23
-------
Appendix B
Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
1000 -
800 -
600-
400 -
200 -
>
E
LU
-200 -
-400 -
-600 -
PH
Figure B.6 Relevant pH-Eh Window And Stable Iron Phases (after
Hem, 1977).
B-24
-------
Appendix B Non-linear Sorption Isotherms Calculated Using the MINTEQA2 Model
5.0 REFERENCES
Dobbs, J.C., W. Susetyo, L.A. Carreira, and L.V. Azarraga, 1989. Competitive binding
of protons and metal ions in humic substances by lanthanide ion probe
spectroscopy. Analytical Chemistry, 61:1519-1524.
Dzombak, D.A. and F.M.M. Morel, 1990. Surface Complexation Modeling: Hydrous
Ferric Oxide. John Wiley & Sons, New York, 393p.
EPRI, 1986. Physiochemical Measurements of Soils at Solid Waste Disposal Sites.
Electric Power Research Institute, prepared by Battelle, Pacific Northwest
Laboratories, Richland, WA, EPRI EA-4417.
Freeze, R.A. and J.A. Cherry, 1979. Groundwater. Prentice-Hall, Inc., New Jersey,
604p.
Gintautas, P.A., K.A. Huyck, S.R. Daniel, and D.L. Macalady, 1993. Metal-Organic
Interactions in Subtitle D Landfill Leachates and Associated Groundwaters, in
Metals in Groundwaters, H.E. Allen, E.M. Perdue, and D.S. Brown, eds. Lewis
Publishers, Ann Arbor, Ml.
Hem, J.D., 1977. Reactions of metal ions at surfaces of metal oxides. Geochimica et
Cosmochimica Acta, 41:527-538.
Mathur, S. S., 1995. Development of a Database for Ion Sorption on Goethite Using
Surface Complexation Modeling. Master's Thesis, Department of Civil and
Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA.
Susetyo, W., L.A. Carreira, L.V. Azarraga, and D.M. Grimm, 1991. Fluorescence
techniques for metal-humic interactions. Fresenius Jour. Analytical Chemistry,
339:624-635.
Tipping, E., 1994. WHAM- A chemical equilibrium model and computer code for
waters, sediments, and soils incorporating a discrete site/electrostatic model of
ion binding by humic substances. Computers and Geosciences, 20:973-1023.
White, D.E., J.D. Hem, and G.A. Waring, 1963. Data of Geochemistry. U.S.
Geological Survey Professional Paper 440-F, U.S. Government Printing Office,
Washington, DC.
B-25
-------
APPENDIX C
PHYSICAL AND CHEMICAL PROPERTIES FOR ORGANIC
CONSTITUENTS
-------
This page intentionally left blank.
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
83-32-9
75-07-0
57-64-1
75-05-8
98-86-2
107-02-8
79-06-1
79-10-7
107-13-1
309-00-2
107-18-6
62-53-3
120-12-7
7440-36-0
7440-38-2
7440-39-3
56-55-3
71-43-2
92-87-5
50-32-8
205-99-2
100-51-6
100-44-7
7440-41-7
111-44-4
39638-32-9
117-81-7
75-27-4
Constituent Name
Acenaphthene
Acetaldehyde [Ethanal]
Acetone (2-propanone)
Acetonitrile (methyl cyanide)
Acetophenone
Acrolein
Acrylamide
Acrylic acid [propenoic acid]
Acrylonitrile
Aldrin
Allyl alcohol
Aniline (benzeneamine)
Anthracene
Antimony
Arsenic
Barium
Benz{a}anthracene
Benzene
Benzidine
Benzo{a}pyrene
Benzo{b}fluoranthene
Benzyl alcohol
Benzyl chloride
Beryllium
Bis(2-chloroethyl)ether
Bis(2-chloroisopropyl)ether
Bis(2-ethylhexyl)phthalate
Bromodichloromethane
Molecular
Weight
(g/mol)
(a)
154.2
44.1
58.1
41.1
120.2
56.1
71.1
72.1
53.1
364.9
58.1
93.1
178.2
121.8
74.9
137.3
228.3
78.1
184.2
252.3
252.3
108.1
126.6
9.0
143.0
171.1
390.6
163.8
Solubility
(mg/L)
(b)
4.24
1.0E+06(e)
1.0E+06(e)
1.0E+06(e)
6.13E+03
2.13E+05
6.4E+05
1.0E+06(e)
7.4E+04
0.18
1.0E+06(e)
3.6E+04
4.3E-02
9.4E-03
1.75E+03
500.0
1.62E-03
1.5E-03
4.0E+04
525.00
1.72E+04
1.31E+03
0.34
6.74E+03
Log Koc
(log[mL/g]
)
(c)
3.75
-0.21 (h)
-0.59
-0.71
1.26
-0.22
-0.99
-1.84
-0.09
6.18
1.47(e)
0.60
4.21
5.34
1.80
1.26
5.80
5.80
0.78
2.84
0.80
2.39
7.13
1.77
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
31.5
0
500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
0
0
0
0
0
6.7E+08
0.018
0
0
0
0
0
0
0
0
0
0
0
0
410
0.23
0
Base
Catalyzed
(Kb)
(1/mol/yr)
0
0
0
45
0
0
0
5.2E+03
0
0
0
0
0
0
0
0
0
0
0
0
0
1.4E+03
5.0E+04
Diffusion
Coefficient
in Water
(Di)
(m2/yr)
(d)
0.0426
0.0363
0.0445
0.0385
0.0397
0.0378
0.0388
0.0184
0.0319
0.01 86 (i)
0.0325
0.0239
0.0208
0.01 74 (i)
0.0278
0.0275
0.0233
0.0132
0.0337
C-1
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
74-83-9
106-99-0
71-36-3
85-68-7
88-85-7
7440-43-9
75-15-0
56-23-5
57-74-9
126-99-8
106-47-8
108-90-7
510-15-6
124-48-1
75-00-3
67-66-3
74-87-3
95-57-8
107-05-1
16065-83-1
18540-29-9
218-01-9
7440-48-4
7440-50-8
108-39-4
95-48-7
Constituent Name
Bromomethane
Butadiene 1,3-
Butanol n-
Butyl benzyl phthalate
Butyl-4,6-dinitrophenol,2-sec-(
Dinoseb)
Cadmium
Carbon disulfide
Carbon tetrachloride
Chlordane
Chloro-1,3-butadiene
2-(Chloroprene)
Chloroaniline p-
Chlorobenzene
Chlorobenzilate
Chlorodibromomethane
Chloroethane [Ethyl chloride]
Chloroform
Chloromethane
Chlorophenol 2-
Chloropropene 3- (Allyl
Chloride)
Chromium (III) (Chromic Ion)
Chromium (VI)
Chrysene
Cobalt
Copper
Cresol m-
Cresol o-
Molecular
Weight
(g/mol)
(a)
94.9
54.1
74.1
312.4
240.2
112.4
76.1
153.8
409.8
88.5
127.6
112.6
325.2
208.3
64.5
119.4
50.5
128.6
76.5
52.0
52.0
228.3
58.9
63.5
108.1
108.1
Solubility
(mg/L)
(b)
1.52E+04
735.00
7.4E+04
2.69
52.00
1.19E+03
793.00
0.06
1.74E+03
5.3E+03
472.00
11.10
2.6E+03
5.68E+03
7.92E+03
5.33E+03
2.2E+04
3.37E+03
1.6E-03
2.27E+04
2.6E+04
Log Koc
(log[mL/g]
)
(c)
0.76
2.06 (e)
0.50
4.23
2.02
1.84
2.41
5.89
1.74
1.61
2.58
4.04
1.91
0.51
1.58
0.91
1.82
1.13
5.34
1.76
1.76
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
9.46
0
0
0
0
0.017
0
0
0
0
0
0
1.0E-04
0
40
0
0
0
Base
Catalyzed
(Kb)
(1/mol/yr)
0
0
1.2E+05
0
31500
0
37.7
0
0
0
2.8E+06
2.5E+04
0
2740
0
0
0
0
0
Diffusion
Coefficient
in Water
(Di)
(m2/yr)
(d)
0.0426
0.0325
0.041
0.0308
0.0172
0.0315
0.0299
0.0173
0.0334
0.0366
0.0344
0.0429
0.0299
0.0341
0.0213
0.0294
0.0311
C-2
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
106-44-5
1319-77-3
98-82-8
108-93-0
108-94-1
72-54-8
72-55-9
50-29-3
2303-16-4
53-70-3
96-12-8
95-50-1
106-46-7
91-94-1
75-71-8
75-34-3
107-06-2
75-35-4
156-59-2
156-60-5
120-83-2
94-75-7
78-87-5
542-75-6
10061-01-5
10061-02-6
Constituent Name
Cresol p-
Cresols
Cumene
Cyclohexanol
Cyclohexanone
ODD
DDE
DDT p,p'-
Diallate
Dibenzja, hjanthracene
Dibromo-3-chloropropane 1 ,2-
Dichlorobenzene 1,2-
Dichlorobenzene 1,4-
Dichlorobenzidine 3,3'-
Dichlorodifluoromethane (Freon
12)
Dichloroethane 1,1-
Dichloroethane 1,2-
Dichloroethylene 1,1-
Dichloroethylene cis-1 ,2-
Dichloroethylene trans-1 ,2-
Dichlorophenol 2,4-
Dichlorophenoxyacetic acid
2,4-(2,4-D)
Dichloropropane 1,2-
Dichloropropene 1,3-(mixture of
isomers)
Dichloropropene cis-1 ,3-
Dichloropropene trans-1 ,3-
Molecular
Weight
(g/mol)
(a)
108.1
324.4
120.2
100.2
98.1
320.0
318.0
354.5
270.2
278.4
236.3
147.0
147.0
253.1
120.9
99.0
99.0
96.9
96.9
96.9
163.0
221.0
113.0
111.0
111.0
111.0
Solubility
(mg/L)
(b)
2.15E+04
2.34E+04
61.30
4.3E+04 (e)
5.0E+03
0.09
0.12
0.03
40.00
0.00
1.23E+03
156.00
73.80
3.11
280.00
5.06E+03
8.52E+03
2.25E+03
3.5E+03
6.3E+03
4.5E+03
677.00
2.8E+03
2.8E+03
2.72E+03
2.72E+03
Log Koc
(log[mL/g]
)
(c)
1.76
2.12
3.40
1.11(9)
1.82
5.89
6.64
6.59
4.17
6.52
1.94
3.08
3.05
3.32
2.16
1.46
1.13
1.79
1.70
1.60
2.49
0.68
1.67
1.43
1.80
1.80
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
0
0
0
0
0
0.025
0
0.06
0.1
0
4.0E-03
0
0
0
1.13E-02
9.61 E-03
0
0
0
0
0
0
40
40
Base
Catalyzed
(Kb)
(1/mol/yr)
0
0
0
0
0
2.2E+04
0
3.1E+05
8.0E+03
0
1.2E+05
0
0
0
0.378
54.7
0
0
0
0
0
0
0
0
Diffusion
Coefficient
in Water
(Di)
(m2/yr)
(d)
0.0291
0.0299
0.0248
0.0295
0.014
0.019
0.0281
0.0281
0.0274
0.01 73 (i)
0.0341
0.0334
0.0344
0.0347
0.0307
0.0319
0.0322
0.0319
C-3
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
60-57-1
84-66-2
56-53-1
60-51-5
119-90-4
58-12-2
57-97-6
119-93-7
105-67-9
84-74-2
99-65-0
51-28-5
121-14-2
506-20-2
117-84-0
123-91-1
122-39-4
122-66-7
298-04-4
115-29-7
72-20-8
106-89-8
106-88-7
110-80-5
111-15-9
141-78-6
Constituent Name
Dieldrin
Diethyl phthalate
Diethylstilbestrol
Dimethoate
Dimethoxybenzidine 3,3'-
Dimethyl formamide N,N-
[DMF]
Dimethylbenz{a}anthracene
7,12-
Dimethylbenzidine 3,3'-
Dimethylphenol 2,4-
Di-n-butyl phthalate
Dinitrobenzene 1,3-
Dinitrophenol 2,4-
Dinitrotoluene 2,4-
Dinitrotoluene 2,6-
Di-n-octyl phthalate
Dioxane 1,4-
Diphenylamine
Diphenylhydrazine1,2-
Disulfoton
Endosulfan (Endosulfan I and
II, mixture)
Endrin
Epichlorohydrin
Epoxybutane 1,2-
Ethoxyethanol 2-
Ethoxyethanol acetate 2-
Ethyl acetate
Molecular
Weight
(g/mol)
(a)
380.9
222.2
268.4
229.2
0.0
73.1
256.3
212.3
122.2
278.3
168.1
184.1
182.1
182.1
390.6
88.1
169.2
184.2
274.4
406.9
380.9
92.5
72.1
90.1
132.2
88.1
Solubility
(mg/L)
(b)
0.20
1.08E+03
0.10
2.5E+04
60.00
1.0E+06(g)
2.50E-02
1.3E+03
7.87E+03
11.20
861.00
2.79E+03
270.00
182.00
0.02
1.0E+06(e)
35.70
68.00
16.30
0.51
0.25
6.59E+04
9.5E+04 (e)
1.0E+06(e)
2.29E+05 (g)
8.03E+04
Log Koc
(log[mL/g]
)
(c)
5.08
1.99
4.09
0.13
1.49
-0.99 (h)
6.64
2.55
2.29
4.37
1.31
-0.09
1.68
1.40
7.60
-0.81
3.30
2.82
2.94
3.55
4.60
-0.53
0.90 (e)
-0.54
0.70 (g)
0.35
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
6.30E-02
0
0
1.68
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2.3
0.055
2.5E+04
0
0
0
0
3.5E+03
Base
Catalyzed
(Kb)
(1/mol/yr)
0
3.1E+05
0
4.48E+06
0
0
0
0
0
Diffusion
Coefficient
in Water
(Di)
m2/yr)
(d)
0.019
0.0353
0.0172(1)
1.8E+06
0
0
0
0
5.2E+05
0
0
0
5.4E+04
0
30.9
0
0
4.8E-03
0.0249
0.0331
0.0229
0.035
0.0331
0.0308
0.0252
3.4E+06
C-4
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
60-29-7
97-63-2
52-50-0
100-41-4
106-93-4
107-21-1
75-21-8
96-45-7
206-44-0
16984-48-8
50-00-0
64-18-6
98-01-1
319-85-7
58-89-9
319-84-6
76-44-8
1024-57-3
87-68-3
118-74-1
77-47-4
55684-94-1
34465-46-8
67-72-1
70-30-4
110-54-3
Constituent Name
Ethyl ether
Ethyl methacrylate
Ethyl methanesulfonate
Ethylbenzene
Ethylene dibromide
(1,2-Dibromoethane)
Ethylene glycol
Ethylene oxide
Ethylene thiourea
Fluoranthene
Fluoride
Formaldehyde
Formic acid
Furfural
HCH beta-
HCH (Lindane) gamma-
HCH alpha-
Heptachlor
Heptachlor epoxide
Hexachloro-1 ,3-butadiene
Hexachlorobenzene
Hexachlorocyclopentadiene
Hexachlorodibenzofurans
[HxCDFs]
Hexachlorodibenzo-p-dioxins
[HxCDDs]
Hexachloroethane
Hexachlorophene
Hexane n-
Molecular
Weight
(g/mol)
(a)
74.1
114.1
124.2
106.2
187.9
62.1
44.1
102.2
202.3
19.0
30.0
46.0
96.1
290.8
290.8
290.8
373.3
389.3
260.8
284.8
272.8
374.9
390.9
236.7
406.9
86.2
Solubility
(mg/L)
(b)
5.68E+04
3.67E+03
6.3E+03
169.00
4.18E+03
1.0E+06(e)
1.0E+06(e)
6.2E+04
0.21
5.5E+05
1.0E+06(e)
1.1E+05
0.24
6.80
2.00
0.18
0.20
3.23
0.01
1.80
8.25E-06 (f)
4.0E-06 (f)
50.00
140.00
12.40
Log Koc
(log[mL/g]
)
(c)
0.55
1.27
-0.27
3.00
1.42
-1.50
-1.10
0.00
4.63
-1.30
-2.70
0.80 (j)
3.43
3.40
3.43
5.21
4.90
4.46
5.41
4.72
7.00
6.38 (g)
3.61
5.00
2.95 (k)
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
0
0
1.25E+03
0
0.63
0
2.9E+05
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1.05
0
61
0.063
0
0
24.8
0
0
0
0
0
Base
Catalyzed
(Kb)
(1/mol/yr)
0
Diffusion
Coefficient
in Water
(Di)
m2/yr)
(d)
1.1E+06
0
0
0
0
21
0
0
0
0
0
0
1.7E+06
0
0
0
0
0
0
0
0
0
0
0
0.0267
0.0331
0.0429
0.046
0.031 9 (i)
0.0549
0.0337
0.0233
0.023
0.0232
0.018
0.0176
0.0222
0.0248
0.0228
0.01 33 (i)
0.01 3 (i)
0.028
0.0256
C-5
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
7783-06-4
193-39-5
78-83-1
78-59-1
143-50-0
7439-92-1
7439-96-5
7439-97-6
126-98-7
67-56-1
72-43-5
109-86-4
110-49-6
78-93-3
108-10-1
80-62-6
298-00-0
1634-04-4
56-49-5
74-95-3
75-09-2
7439-98-7
91-20-3
7440-02-0
98-95-3
79-46-9
55-18-5
Constituent Name
Hydrogen Sulfide
lndeno{1,2,3-cd}pyrene
Isobutyl alcohol
Isophorone
Kepone
Lead
Manganese
Mercury
Methacrylonitrile
Methanol
Methoxychlor
Methoxyethanol 2-
Methoxyethanol acetate 2-
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methyl parathion
Methyl tert-butyl ether [MTBE]
Methylcholanthrene 3-
Methylene bromide
(Dibromomethane)
Methylene Chloride
(Dichloromethane)
Molybdenum
Naphthalene
Nickel
Nitrobenzene
Nitropropane 2-
Nitrosodiethylamine N-
Molecular
Weight
(g/mol)
(a)
34.1
276.3
74.1
138.2
490.6
207.2
54.9
200.6
67.1
32.0
345.7
76.1
118.1
72.1
100.2
100.1
263.2
88.1
268.4
173.8
84.9
95.9
128.2
58.7
123.1
89.1
102.1
Solubility
(mg/L)
(b)
437.00
2.2E-05
8.5E+04
1.2E+04
7.60
0.06
25400.00
1.0E+06(e)
0.05
1.0E+06(e)
1.0E+06(m)
2.23E+05
1.9E+04
1.5E+04
55.00
5.13E+04(e)
0.00
1.19E+04
1.3E+04
31.00
2.09E+03
1.7E+04
9.3E+04
Log Koc
(log[mL/g]
)
(c)
6.26
0.44
1.90
4.15
0.22
-1.08
4.90
0.95 (e)
-0.03
0.87
0.74
2.47
1.05(e)
7.00
1.21
0.93
3.11
1.51
0.23
-0.03
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
0
0
0
0
0
0
0
0.69
0
0
0
0
0
2.8
0
1.7E-02
0
1.0E-03
0
0
0
0
Base
Catalyzed
(Kb)
(1/mol/yr)
0
0
0
0
0
5.2E+03
0
1.2E+04
0
0
0
0
0
0
0
0
0.6
0
0
0
0
Diffusion
Coefficient
in Water
(Di)
(m2/yr)
(d)
0.01 64 (i)
0.0238
0.0949
0.0334
0.052
0.0347
0.0275
0.0322
0.0264
0.0292
0.0272
0.0194
0.0394
0.0264
0.0298
0.0322
0.0288
C-6
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
52-75-9
924-16-3
521-64-7
86-30-6
10595-95-6
100-75-4
930-55-2
152-16-9
56-38-2
508-93-5
30402-15-4
36088-22-9
82-68-8
87-86-5
108-95-2
52-38-4
108-45-2
298-02-2
85-44-9
1336-36-3
23950-58-5
75-56-9
129-00-0
110-86-1
94-59-7
Constituent Name
Nitrosodimethylamine N-
Nitroso-di-n-butylamine N-
Nitroso-di-n-propylamine N-
Nitrosodiphenylamine N-
Nitrosomethylethylamine N-
Nitrosopiperidine N-
Nitrosopyrrolidine N-
Octamethyl
pyrophosphoramide
Parathion (ethyl)
Pentachlorobenzene
Pentachlorodibenzofurans
[PeCDFs]
Pentachlorodibenzo-p-dioxins
[PeCDDs]
Pentachloronitrobenzene
(PCNB)
Pentachlorophenol
Phenol
Phenyl mercuric acetate
Phenylenediamine 1,3-
Phorate
Phthalic anhydride
Polychlorinated biphenyls
(Aroclors)
Pronamide
Propylene oxide
[1 ,2-Epoxypropane]
Pyrene
Pyridine
Safrole
Molecular
Weight
(g/mol)
(a)
74.1
158.2
130.2
198.2
88.1
114.1
100.1
286.3
291.3
250.3
340.4
356.4
295.3
266.3
94.1
336.7
108.1
260.4
148.1
256.1
58.1
202.3
79.1
162.2
Solubility
(mg/L)
(b)
1.0E+06(e)
1.27E+03
9.89E+03
35.10
1.97E+04
7.65E+04
1.0E+06(e)
1.0E+06(m)
6.54
1.33
2.40E-04 (f)
1.18E-04(f)
0.55
1.95E+03
8.28E+04
2.0E+03
2.55E+06
50.00
6.2E+03
0.07
32.80
4.05E+05 (e)
0.14
1.0E+06(e)
810.67
Log Koc
(log[mL/g]
)
(c)
0.45
2.09
1.03
2.84
1.03
-0.02
-0.57
-0.51
3.15
5.39
4.93 (g)
6.3 (g)
4.57
3.06
1.23
0.00
-0.30
2.64
1.56(e)
6.19
2.63
1.40(e)
4.92
0.34
2.34
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
0
0
0
0
0
0
0
1.9E+03
0
0
0
0
0
0
0
0
0
0
0
0
59
0
0
0
0
2.4
0
0
0
0
0
0
0
0
62
4.9E+05
0
0
0
0
0
0
Base
Catalyzed
(Kb)
(1/mol/yr)
0
0
0
0
0
0
0
3.7E+06
0
0
0
0
0
0
0
0
0
0
0
610
0
0
0
0
Diffusion
Coefficient
in Water
(Di)
(m2/yr)
(d)
0.0363
0.0215
0.0245
0.0227
0.0315
0.029
0.0319
0.01 42 (i)
0.01 38 (i)
0.0253
0.0325
0.0308
0.0189
0.0382
0.0344
C-7
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
7782-49-2
7440-22-4
57-24-9
100-42-5
95-94-3
51207-31-9
1746-01-6
630-20-6
79-34-5
127-18-4
58-90-2
3689-24-5
7440-28-0
137-26-8
108-88-3
95-80-7
95-53-4
106-49-0
8001-35-2
75-25-2
76-13-1
120-82-1
71-55-6
79-00-5
79-01-6
Constituent Name
Selenium
Silver
Strychnine and salts
Styrene
Tetrachlorobenzene 1,2,4,5-
Tetrachlorodibenzofuran
2,3,7,8-
Tetrachlorodibenzo-p-dioxin
2,3,7,8-
Tetrachloroethane 1,1,1,2-
Tetrachloroethane 1,1,2,2-
Tetracriloroethylene
Tetrachlorophenol 2,3,4,6-
Tetraethyl dithiopyrophosphate
(Sulfotep)
Thallium
Thiram [Thiuram]
Toluene
Toluenediamine 2,4-
Toluidine o-
Toluidine p-
Toxaphene (chlorinated
camphenes)
Tribromomethane (Bromoform)
Trichloro-1,2,2-trifluoro-ethane
1,1,2-
Trichlorobenzene 1,2,4-
Trichloroethane 1,1,1-
Trichloroethane 1,1,2-
Trichloroethylene
(Trichloroethylene1,1,2-)
Molecular
Weight
(g/mol)
(a)
79.0
107.9
334.4
104.2
215.9
306.0
322.0
167.8
167.8
165.8
231.9
322.3
204.4
240.4
92.1
122.2
107.2
107.2
252.7
187.4
181.4
133.4
133.4
131.4
Solubility
(mg/L)
(b)
160.00
310.00
0.60
6.92E-04 (f)
7.91E-06(f)
1.1E+03
2.97E+03
200.00
100.00
25.00
30.00
526.00
3.37E+04
1.66E+04
782.00
0.74
3.1E+03
170.00
34.60
1.33E+03
4.42E+03
1.1E+03
Log Koc
(log[mL/g]
)
(c)
1.90
2.84
4.28
6.62
6.10
2.71
2.07
2.21
2.32
3.51
2.83 (e)
2.43
0.02
1.24
1.24
4.31
2.05
2.97
3.96
2.16
1.73
2.10
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
0
0
0
0
0
0.0137
5.1E-03
0
0
84
0
0
0
0
0
0.07
0
0
0.64
2.73E-05
0
Base
Catalyzed
(Kb)
(1/mol/yr)
0
0
0
0
0
1.13E+04
1.59E+07
0
0
9.0E+06
0
0
0
0
0
2.8E+04
1.0E+04
0
0
2.4E+06
4.95E+04
0
Diffusion
Coefficient
in Water
(Di)
(m2/yr)
(d)
0.0278
0.01 53 (i)
0.01 48 (i)
0.0287
0.0293
0.0298
0.0291
0.0282 (i)
0.029
0.0173
0.0328
0.0271
0.0265
0.0303
0.0315
0.0322
C-8
-------
Appendix C
Physical and Chemical Properties for Organic Constituents
CAS
75-69-4
95-95-4
88-06-2
93-72-1
93-76-5
96-18-4
121-44-8
99-35-4
126-72-7
7440-62-2
108-05-4
75-01-4
108-38-3
95-47-6
106-42-3
1330-20-7
7440-66-6
Constituent Name
Trichlorofluoromethane (Freon
11)
Trichlorophenol 2,4,5-
Trichlorophenol 2,4,6-
Trichlorophenoxy)propionic
acid 2-(2,4,5-
Trichlorophenoxyacetic acid
2,4,5-
Trichloropropane 1,2,3-
Triethylamine
Trinitrobenzene
(Trinitrobenzene 1,3,5-)
Tris(2,3-dibromopropyl)phosph
ate
Vanadium
Vinyl acetate
Vinyl chloride
Xylene m-
Xylene o-
Xylene p-
Xylenes (total)
Zinc
Molecular
Weight
(g/mol)
(a)
137.4
197.4
197.4
269.5
255.5
147.4
101.2
213.1
697.6
50.9
86.1
62.5
106.2
106.2
106.2
318.5
65.4
Solubility
(mg/L)
(b)
1.1E+03
1.2E+03
800.00
140.00
268.30
1.75E+03
5.5E+04 (e)
350.00
8.00
2.0E+04
2.76E+03
161.00
178.00
185.00
175.00
Log Koc
(log[mL/g]
)
(c)
2.11
2.93
2.25
1.74
1.43
1.66
1.31 (I)
1.05
3.19
0.45
1.04
3.09
3.02
3.12
3.08
Hydrolysis Rate Constants (c)
Acid
Catalyzed
(Ka)
(1/mol/yr)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Neutral
(Kn)
(1/yr)
0
0
0
0
0
1.7E-02
0
0
8.8E-02
0
0
0
0
0
0
Base
Catalyzed
(Kb)
(1/mol/yr)
0
0
0
0
0
3.6E+03
0
0
3.0E+05
0
0
0
0
0
0
Diffusion
Coefficient
in Water
(Di)
(m2/yr)
(d)
0.0319
0.0255
0.0291
0.0247
0.0315
0.0378
0.0267
0.027
0.0267
0.0268
Note: Data sources for chemical property values are indicated in the column
headings; exceptions are noted in parentheses for individual chemical values.
Data sources:
a. http://chemfinder.cambridgesoft.com (CambridgeSoft Corporation, 2001)
b. U.S. EPA, 1997b. Superfund Chemical Data Matrix (SCDM). SCDMWIN 1.0
(SCDM Windows User's Version), Version 1. Office of Solid Waste and
Emergency Response, Washington DC: GPO.
http://www.epa.gov/superfund/resources/scdm/index.htm. Accessed July
2001
C-9
-------
Appendix C Physical and Chemical Properties for Organic Constituents
c. Kollig, H. P. (ed), 1993. Environmental fate consultants for organic
chemicals under consideration for EPA's hazardous waste identification
projects. Environmental Research Laboratory, Office of R&D, U.S. EPA,
Athens, GA.
d. Calculated based on Water 9. U.S. EPA, 2001. Office of Air Quality Planning
and Standards, Research Triangle Park, NC.
http://www.epa.gov/ttn/chief/software/water/index.html. Accessed July 2001
e. Syracuse Research Corporation (SRC), 1999. CHEMFATE Chemical
Search, Environmental Science Center, Syracuse, NY.
http://esc.syrres.com/efdb/Chemfate.htm. Accessed July 2001.
f. Calculated based on U.S. EPA, 2000. Exposure and Human Health
Reassessment of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and Related
Compounds, Part 1, Vol. 3. Office of Research and Development,
Washington, DC: GPO.
g. USNLM (U.S. National Library of Medicine), 2001. Hazardous Substances
Data Bank (HSDB). http://toxnet.nlm.nih.gov/cai-bin/sis/htmlaen/HSDB.
Accessed July 2001.
h. Ml DEQ. Environmental response Division Operational Memorandum #18
(Opmemo 18): Part 201 Generic Cleanup Criteria Tables, Revision 1, State
of Michigan, Department of Environmental Quality.
http://www.deq.state.mi.us/erd/opmemo18/index.html.
i. Calculated based on U.S. EPA, 1987. Process Coefficients and Models for
Simulating Toxic Organics and Heavy Metals in Surface Waters. Office of
Research and Development. Washington, DC: US Government Printing
Office (GPO).
j. U.S. EPA, 1999. Region III Soil-to-Groundwater SSLs. Region III,
Philadelphia, PA. http://www.epa.qov/rea3hwmd/risk/ssl.pdf
k. U.S. EPA, 2000. Physical-chemical
Data.http://www.epa.gov/Rgeion9/waste/sfund/prg/index.htm
I. Calculated from octanol-water partition coefficient using regression equation
log[Koc] = 1.029 x log[Kow] - 0.18; presented in Table 10.2 of G. deMarsily,
1986. Quantitative Hydrogeology. Academic Press
m. Lyman, W.J., W.F. Reehl, and D.H. Rosenblatt, 1990. Handbook of
Chemical Property Estimation Methods: Environmental Behavior of Organic
Compounds. Washington, DC: American Chemical Society.
C-10
-------
APPENDIX D
WMU AND HYDROGEOLOGIC ENVIRONMENT DATABASES
-------
This page intentionally left blank.
-------
LIST OF TABLES
Page
Table D.1 Nationwide Database of Landfill Sites D-1
Table D.2 Nationwide Database of Surface Impoundment Sites D-18
Table D.3 Nationwide Database of Waste Pile Sites D-40
Table D.4 Nationwide Database of Land Application Unit Sites D-59
Table D.5 Hydrogeologic Database for HG Environment 1 D-66
Table D.6 Hydrogeologic Statistics for HG Environment 1 D-67
Table D.7 Hydrogeologic Database for HG Environment 2 D-67
Table D.8 Hydrogeologic Statistics for HG Environment 2 D-69
Table D.9 Hydrogeologic Database for HG Environment 3 D-69
Table D.10 Hydrogeologic Statistics for HG Environment 3 D-70
Table D.11 Hydrogeologic Database for HG Environment 4 D-70
Table D.12 Hydrogeologic Statistics for HG Environment 4 D-72
Table D.13 Hydrogeologic Database for HG Environment 5 D-72
Table D.14 Hydrogeologic Statistics for HG Environment 5 D-74
Table D.15 Hydrogeologic Database for HG Environment 6 D-75
Table D.16 Hydrogeologic Statistics for HG Environment 6 D-76
Table D.17 Hydrogeologic Database for HG Environment 7 D-76
Table D.18 Hydrogeologic Statistics for HG Environment 7 D-78
Table D.19 Hydrogeologic Database for HG Environment 8 D-78
Table D.20 Hydrogeologic Statistics for HG Environment 8 D-80
Table D.21 Hydrogeologic Database for HG Environment 9 D-80
Table D.22 Hydrogeologic Statistics for HG Environment 9 D-81
Table D.23 Hydrogeologic Database for HG Environment 10 D-82
Table D.24 Hydrogeologic Statistics for HG Environment 10 D-83
Table D.25 Hydrogeologic Database for HG Environment 11 D-83
Table D.26 Hydrogeologic Statistics for HG Environment 11 D-84
Table D.27 Hydrogeologic Database for HG Environment 12 D-85
Table D.28 Hydrogeologic Statistics for HG Environment 12 D-86
Table D.29 Hydrogeologic Database for HG Environment 13 D-86
D-i
-------
This page intentionally left blank.
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
Area
(m2}
3.04E+04
2.97E+04
1.35E+04
4.05E+04
2.02E+04
4.45E+05
3.84E+04
1.11E+05
3.24E+04
1.21E+04
6.15E+05
1.63E+04
2.02E+04
3.04E+04
1.21E+04
8.09E+04
2.02E+03
6.07E+04
6.07E+04
1.21E+04
9.31 E+03
8.09E+03
2.02E+05
3.24E+04
4.05E+04
4.86E+03
2.02E+02
4.05E+03
2.02E+03
5.06E+03
2.02E+04
4.86E+04
1.21E+04
6.07E+04
1.09E+05
1.21E+05
2.43E+04
1.42E+05
4.05E+03
6.88E+04
3.04E+04
3.35E+05
2.71 E+03
6.07E+04
2.02E+06
1.42E+04
1.42E+04
Depth
(m}
-999
3.12
0.67
1.47
3.85
7.68
0.86
2.08
4.30
0.74
1.02
-999
-999
-999
-999
-999
-999
3.17
0.76
0.68
-999
1.22
1.31
7.67
-999
1.36
-999
4.09
4.42
-999
-999
1.19
6.82
1.78
1.52
-999
1.01
0.69
1.23
1.83
-999
-999
3.05
3.00
2.83
1.17
-999
Soil/GW
Temperature
ro
12.5
22.5
22.5
17.5
12.5
12.5
12.5
12.5
12.5
22.5
7.5
17.5
12.5
12.5
22.5
17.5
17.5
12.5
17.5
12.5
17.5
17.5
17.5
17.5
17.5
12.5
7.5
7.5
12.5
17.5
22.5
17.5
17.5
17.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
22.5
12.5
HG
Environment
1
5
4
4
2
12
4
2
5
4
2
13
12
1
4
2
1
2
13
12
1
12
12
4
5
2
4
2
4
2
12
12
4
5
2
9
4
4
4
12
5
4
4
13
12
4
2
Nearest
Climate
Center
69
92
58
93
51
85
74
39
51
58
32
90
42
69
81
36
95
39
34
54
95
89
95
89
13
39
43
66
36
36
78
85
95
89
74
42
91
71
39
54
51
52
45
49
88
96
39
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
19.63
19.63
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
2.69
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-1
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
Area
(m2}
8.09E+03
8.09E+04
4.05E+04
5.26E+04
2.02E+04
1.01E+05
3.97E+04
1.11E+05
1.34E+04
4.86E+04
1.27E+05
9.47E+04
6.07E+04
3.32E+05
2.23E+04
6.96E+04
6.07E+04
6.88E+04
4.05E+03
5.26E+05
2.87E+04
4.05E+04
7.28E+04
1.72E+05
1.01E+04
3.14E+04
1.07E+05
5.06E+04
6.92E+04
1.42E+05
1.94E+04
7.16E+04
9.31 E+04
3.24E+05
3.72E+05
1.21E+03
4.17E+03
2.51 E+05
1.35E+05
1.66E+03
1.35E+05
8.09E+04
2.55E+05
4.57E+04
3.24E+03
2.10E+05
5.67E+04
Depth
(m}
7.90
0.55
2.86
2.05
0.98
2.45
2.38
7.47
0.84
-999
1.01
1.75
0.87
5.24
2.02
-999
-999
3.32
2.05
3.64
1.93
7.65
-999
-999
5.37
4.83
5.56
1.77
5.09
-999
1.28
3.93
-999
1.84
-999
3.15
2.78
-999
6.55
7.98
4.09
1.53
7.79
-999
-999
1.26
2.51
Soil/GW
Temperature
ro
17.5
7.5
17.5
7.5
12.5
12.5
12.5
17.5
12.5
12.5
12.5
12.5
12.5
17.5
12.5
17.5
17.5
12.5
17.5
12.5
17.5
12.5
7.5
12.5
17.5
12.5
12.5
12.5
17.5
12.5
12.5
12.5
17.5
12.5
12.5
17.5
17.5
12.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
7.5
12.5
HG
Environment
13
4
12
2
8
4
2
12
9
1
12
1
4
5
5
12
1
8
4
4
2
2
8
4
12
5
4
2
4
12
12
9
12
12
2
5
2
12
9
9
4
5
2
1
2
13
2
Nearest
Climate
Center
34
60
85
32
32
52
39
95
73
71
50
71
71
13
56
95
77
75
93
49
36
39
48
72
95
3
51
39
23
71
69
32
85
42
69
34
95
73
42
73
81
40
71
71
39
68
52
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-2
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
Area
(m2}
5.67E+02
5.54E+05
2.43E+04
9.79E+05
5.26E+04
2.19E+05
2.83E+04
8.09E+03
2.27E+05
4.05E+03
8.50E+04
7.08E+04
2.02E+04
2.43E+04
8.09E+03
3.28E+03
1.34E+05
1.62E+04
3.64E+04
4.05E+05
2.02E+05
8.09E+02
3.24E+04
4.86E+04
8.50E+02
4.86E+04
5.14E+05
3.12E+06
8.09E+04
1.30E+04
2.02E+04
4.17E+03
2.02E+03
1.41E+06
1.17E+04
6.07E+04
2.23E+05
4.05E+04
4.05E+02
8.09E+04
2.27E+04
2.02E+02
2.14E+05
1.54E+05
2.71 E+04
8.09E+05
1.00E+06
Depth
(m}
1.29
0.53
4.09
0.54
1.13
3.12
2.34
-999
-999
2.95
2.18
-999
6.71
0.82
-999
1.52
1.99
3.07
1.19
-999
1.31
-999
-999
1.58
-999
-999
-999
-999
-999
1.98
-999
-999
-999
-999
0.65
-999
-999
3.96
-999
-999
5.41
1.36
4.82
-999
0.99
8.18
2.35
Soil/GW
Temperature
ro
22.5
12.5
12.5
12.5
17.5
12.5
12.5
17.5
12.5
12.5
22.5
12.5
12.5
7.5
17.5
12.5
7.5
12.5
17.5
12.5
12.5
7.5
22.5
22.5
12.5
22.5
7.5
22.5
12.5
17.5
22.5
22.5
17.5
22.5
22.5
17.5
12.5
22.5
17.5
17.5
12.5
22.5
7.5
22.5
7.5
12.5
22.5
HG
Environment
12
5
4
12
2
2
2
1
12
2
12
9
12
4
12
12
13
2
1
9
12
13
12
4
12
12
13
4
12
12
12
12
4
5
13
4
2
4
2
2
5
13
8
12
2
2
4
Nearest
Climate
Center
91
26
39
49
95
71
39
95
42
53
93
42
42
66
95
69
4
88
77
73
55
68
57
92
50
91
5
92
71
95
57
93
29
92
96
81
39
92
36
89
33
92
31
78
31
39
58
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
16.22
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
22.01
2.55
2.55
2.55
2.55
2.55
2.55
2.55
1.00
1.00
1.00
D-3
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
Area
(m2}
7.08E+05
7.16E+05
2.02E+04
2.54E+05
1.01E+05
2.02E+04
5.26E+04
5.26E+02
1.86E+05
6.07E+04
2.23E+04
1.72E+06
1.21E+05
2.63E+05
1.86E+05
5.67E+04
7.69E+05
1.21E+05
1.62E+06
8.09E+03
3.44E+04
6.27E+05
2.23E+04
2.43E+04
4.45E+04
1.50E+04
1.97E+06
1.21E+06
1.24E+06
2.02E+06
5.10E+05
4.86E+04
3.24E+04
5.54E+05
8.09E+05
8.09E+03
2.51 E+04
1.62E+06
1.62E+05
6.75E+04
2.59E+05
2.67E+05
1.62E+05
2.23E+05
4.65E+03
1.01E+06
8.05E+05
Depth
(m}
4.24
2.14
-999
2.09
-999
-999
1.01
2.03
1.72
-999
1.36
-999
0.65
-999
-999
-999
3.75
4.36
-999
2.62
6.26
6.55
1.26
1.21
-999
1.58
-999
6.00
2.81
3.96
-999
0.55
-999
-999
7.26
-999
0.96
6.14
-999
1.95
0.76
4.20
7.06
6.32
0.66
-999
1.64
Soil/GW
Temperature
ro
12.5
17.5
12.5
17.5
12.5
22.5
12.5
22.5
12.5
12.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
17.5
17.5
12.5
17.5
22.5
12.5
7.5
22.5
12.5
12.5
22.5
12.5
22.5
17.5
7.5
7.5
7.5
12.5
17.5
17.5
22.5
12.5
7.5
12.5
12.5
HG
Environment
5
13
2
4
6
12
2
4
4
1
5
2
2
13
12
12
8
2
5
1
4
2
2
13
5
12
4
12
2
4
2
4
4
13
5
12
1
13
2
12
4
13
4
2
2
13
5
Nearest
Climate
Center
26
90
52
80
89
58
28
96
27
72
4
39
91
73
73
42
55
39
51
63
72
39
93
77
29
95
96
49
32
81
51
40
92
56
22
89
31
49
11
20
92
34
58
51
7
73
74
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-4
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
Area
(m2}
1.86E+06
1.18E+06
2.02E+03
9.92E+04
7.16E+05
1.23E+05
1.46E+04
1.66E+05
1.62E+04
7.08E+05
9.29E+04
5.26E+05
1.48E+06
6.48E+03
2.02E+04
4.87E+05
5.46E+04
1.66E+05
1.21E+05
4.05E+03
1.69E+06
1.25E+05
5.67E+04
2.02E+03
4.53E+05
4.05E+03
4.05E+04
2.02E+04
1.82E+05
1.21E+05
8.50E+02
9.31 E+02
2.83E+04
7.29E+02
1.42E+04
8.09E+04
8.09E+04
1.66E+04
8.90E+04
2.02E+04
8.90E+03
3.24E+04
5.67E+04
4.05E+04
6.48E+04
5.67E+02
1.11E+04
Depth
(m}
4.55
6.66
1.32
5.01
2.14
4.29
-999
-999
-999
4.24
-999
3.55
-999
0.51
6.55
-999
5.11
5.99
5.28
1.32
4.98
3.32
1.32
-999
8.04
-999
4.91
-999
3.64
-999
-999
-999
-999
2.36
3.27
4.11
1.23
5.39
1.39
-999
1.23
1.33
2.63
-999
2.76
0.88
-999
Soil/GW
Temperature
ro
12.5
22.5
17.5
12.5
17.5
7.5
12.5
17.5
17.5
12.5
17.5
22.5
17.5
12.5
12.5
12.5
7.5
12.5
17.5
12.5
17.5
12.5
12.5
22.5
7.5
22.5
12.5
7.5
12.5
22.5
17.5
17.5
22.5
17.5
17.5
12.5
12.5
12.5
17.5
22.5
22.5
12.5
17.5
22.5
12.5
17.5
12.5
HG
Environment
5
4
2
2
5
4
9
4
4
5
2
4
4
12
12
4
5
8
13
12
4
12
13
5
4
4
12
13
2
4
13
1
4
4
4
5
12
1
13
4
4
6
2
12
4
4
12
Nearest
Climate
Center
51
36
36
85
90
10
42
95
93
26
89
36
81
71
87
51
10
55
34
69
93
54
73
12
7
81
19
10
39
92
77
79
58
89
80
74
69
77
29
58
96
73
30
57
88
89
85
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.38
1.38
1.38
1.38
1.38
1.38
1.38
1.38
1.38
1.38
1.00
7.56
7.56
1.05
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.81
1.81
D-5
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
Area
(m2}
7.90E+04
4.45E+02
4.05E+03
1.62E+04
1.01E+04
4.86E+04
4.86E+04
1.05E+05
1.38E+03
1.11E+04
1.94E+04
7.69E+04
2.94E+04
3.64E+03
4.05E+02
2.02E+04
3.80E+04
2.12E+03
6.75E+04
4.43E+03
2.63E+04
2.02E+04
4.25E+04
2.02E+04
2.83E+04
6.88E+04
2.02E+04
3.89E+04
2.43E+04
2.63E+05
8.09E+04
1.38E+04
5.22E+03
6.39E+05
2.02E+04
1.01E+04
7.04E+04
3.64E+04
8.09E+03
3.24E+04
9.29E+04
4.04E+04
6.21 E+04
5.79E+03
2.02E+04
6.52E+03
8.13E+04
Depth
(m}
-999
1.12
2.45
-999
-999
-999
-999
-999
3.57
2.20
-999
3.70
-999
3.64
6.55
-999
0.52
-999
1.10
1.03
-999
-999
2.44
-999
3.51
1.20
1.27
3.47
2.97
1.35
1.31
1.14
1.08
-999
0.65
-999
-999
0.68
-999
-999
-999
1.06
1.02
0.80
3.54
1.27
-999
Soil/GW
Temperature
ro
12.5
12.5
12.5
17.5
12.5
12.5
12.5
17.5
22.5
12.5
12.5
17.5
17.5
17.5
12.5
22.5
22.5
17.5
17.5
17.5
12.5
12.5
17.5
22.5
12.5
12.5
22.5
17.5
17.5
17.5
22.5
22.5
12.5
12.5
12.5
7.5
12.5
22.5
22.5
17.5
17.5
12.5
12.5
22.5
22.5
12.5
22.5
HG
Environment
12
13
5
12
12
1
4
13
12
4
12
12
5
1
1
4
4
5
4
12
4
13
4
12
12
4
4
12
12
4
4
4
12
2
5
4
9
12
12
13
4
5
13
4
4
2
4
Nearest
Climate
Center
55
16
39
95
54
88
71
34
93
72
89
89
13
85
72
92
35
89
79
85
74
26
93
57
69
72
81
89
85
89
96
81
49
87
34
60
42
78
93
90
29
40
26
92
81
51
96
Site
Weiahtina
1.81
1.81
1.81
1.81
1.81
1.81
1.81
1.81
1.81
1.81
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-6
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
Area
(m2}
5.26E+04
2.12E+06
6.07E+04
9.31 E+04
2.67E+04
4.00E+04
4.05E+04
2.23E+04
2.02E+04
6.88E+04
3.72E+04
4.35E+04
6.07E+04
8.62E+04
6.07E+04
2.79E+03
4.05E+03
1.21E+03
8.09E+03
1.21 E+04
8.09E+04
1.86E+03
8.09E+01
2.02E+03
2.02E+04
3.72E+03
8.09E+03
2.43E+02
9.31 E+02
1.01 E+04
1.01 E+04
2.02E+04
8.09E+03
8.09E+01
1.62E+05
4.05E+04
2.02E+02
1.01E+03
1.21 E+04
1.62E+03
2.63E+04
6.07E+04
4.05E+03
2.02E+03
8.09E+03
2.47E+04
4.05E+04
Depth
(m}
-999
-999
0.65
2.67
-999
0.69
-999
-999
4.09
8.02
1.33
4.22
2.73
-999
-999
1.98
1.82
-999
-999
-999
4.09
-999
3.03
1.23
-999
0.89
-999
2.05
7.12
-999
-999
1.02
0.61
-999
-999
2.45
-999
-999
-999
-999
4.56
5.46
0.82
-999
-999
-999
-999
Soil/GW
Temperature
ro
17.5
22.5
17.5
22.5
22.5
12.5
17.5
22.5
7.5
22.5
17.5
17.5
12.5
12.5
17.5
22.5
17.5
12.5
22.5
12.5
12.5
12.5
17.5
22.5
22.5
7.5
22.5
17.5
12.5
12.5
22.5
12.5
12.5
22.5
17.5
22.5
17.5
17.5
22.5
12.5
17.5
12.5
12.5
17.5
17.5
12.5
12.5
HG
Environment
5
5
13
4
4
4
5
12
13
4
4
12
2
5
13
6
1
4
4
8
4
9
1
4
5
8
4
12
8
12
12
12
5
12
13
4
13
1
12
4
4
13
12
4
5
1
4
Nearest
Climate
Center
13
92
81
92
35
51
13
78
5
96
89
89
69
87
81
92
77
72
92
42
52
56
77
91
21
45
92
85
46
73
57
39
3
58
77
92
1
95
57
19
79
86
42
89
34
84
74
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.38
1.38
1.38
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
D-7
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
Area
(m2}
6.07E+03
8.90E+04
4.45E+02
2.43E+04
6.07E+03
4.05E+03
2.83E+02
2.43E+04
4.05E+01
2.83E+04
4.05E+04
6.07E+04
4.05E+03
4.05E+03
9.31 E+02
2.02E+02
3.90E+04
8.09E+03
1.14E+04
6.07E+04
2.23E+04
3.04E+03
8.09E+03
1.21E+03
8.09E+03
8.09E+03
1.01E+04
4.05E+03
4.86E+04
4.05E+01
2.43E+04
8.09E+03
6.07E+03
4.05E+04
1.43E+04
1.16E+04
8.82E+03
4.05E+04
8.09E+03
4.46E+04
4.05E+03
1.42E+04
1.09E+04
3.72E+04
2.55E+04
4.45E+05
2.43E+05
Depth
(m}
-999
4.09
1.38
3.07
5.73
0.74
2.60
5.11
0.91
4.09
1.32
-999
2.05
1.23
3.69
-999
3.98
-999
0.79
-999
0.77
2.73
-999
-999
-999
-999
0.92
-999
1.26
-999
-999
-999
1.09
-999
1.45
-999
2.38
3.17
6.60
3.97
5.11
-999
4.55
4.46
2.79
5.58
6.82
Soil/GW
Temperature
ro
17.5
17.5
12.5
17.5
12.5
17.5
7.5
12.5
22.5
12.5
17.5
17.5
17.5
7.5
12.5
12.5
7.5
17.5
17.5
7.5
12.5
17.5
17.5
22.5
17.5
17.5
12.5
22.5
12.5
17.5
12.5
17.5
22.5
22.5
17.5
12.5
12.5
12.5
12.5
17.5
22.5
22.5
7.5
12.5
7.5
17.5
7.5
HG
Environment
12
5
13
4
4
13
13
2
12
12
13
1
2
4
2
9
2
12
12
12
4
1
1
12
4
1
8
4
2
5
8
4
4
13
5
2
5
4
2
1
4
4
13
5
4
2
4
Nearest
Climate
Center
89
21
29
80
39
34
66
51
76
73
36
95
36
5
88
73
31
85
95
48
88
79
79
57
95
95
56
81
52
90
55
80
12
12
13
39
51
51
52
79
96
12
66
40
60
36
68
Site
Weiahtina
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
9.25
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-8
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
Area
(m2}
6.07E+03
6.07E+03
8.09E+03
8.09E+03
5.77E+04
3.24E+05
3.75E+04
4.25E+02
4.86E+05
5.67E+04
1.26E+05
8.09E+03
2.83E+04
2.63E+05
1.62E+05
1.38E+03
1.62E+05
1.05E+05
1.02E+04
4.45E+03
1.82E+04
3.24E+04
3.84E+05
4.86E+04
2.23E+05
2.23E+04
5.67E+04
1.01E+05
4.05E+03
1.01E+04
3.91 E+04
1.01E+04
9.31 E+04
1.67E+04
1.62E+04
8.09E+04
1.21 E+04
1.16E+04
2.79E+04
2.31 E+04
1.63E+04
8.09E+03
1.27E+04
4.45E+04
2.59E+03
4.86E+03
8.09E+03
Depth
(m}
6.87
4.09
0.61
3.27
2.77
7.16
-999
-999
-999
1.05
-999
0.59
3.11
3.78
4.50
3.01
2.56
-999
3.83
3.95
7.07
0.77
6.46
5.11
5.28
1.12
-999
5.24
-999
-999
2.93
-999
1.78
2.18
-999
-999
-999
-999
2.20
-999
3.81
-999
-999
-999
8.31
3.20
0.82
Soil/GW
Temperature
ro
7.5
12.5
17.5
22.5
17.5
7.5
12.5
7.5
7.5
17.5
22.5
12.5
7.5
12.5
17.5
12.5
17.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
22.5
12.5
12.5
17.5
22.5
17.5
17.5
17.5
17.5
12.5
12.5
17.5
12.5
12.5
17.5
12.5
22.5
12.5
12.5
17.5
12.5
12.5
17.5
HG
Environment
13
4
12
2
1
12
1
13
8
10
4
1
2
12
4
2
5
12
4
12
2
13
4
12
4
12
2
2
12
5
4
5
12
4
12
4
2
5
13
2
13
2
12
4
4
5
2
Nearest
Climate
Center
66
72
89
58
77
50
61
66
48
79
12
61
50
42
79
71
21
49
39
71
66
72
51
39
14
54
55
36
58
13
89
34
85
39
49
79
39
39
90
39
36
39
77
30
52
26
89
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.33
1.33
1.33
1.33
1.33
1.33
D-9
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
Area
(m2}
2.02E+03
5.26E+02
3.48E+04
5.26E+04
2.17E+05
4.05E+04
1.21E+05
7.35E+04
2.23E+04
8.09E+03
4.05E+03
4.05E+04
1.21E+05
1.05E+05
3.72E+03
3.44E+04
2.43E+04
8.09E+03
6.07E+04
2.02E+04
4.05E+03
5.26E+03
2.43E+05
2.83E+02
7.53E+04
1.21E+04
6.07E+03
1.21E+04
4.86E+03
8.09E+03
1.98E+05
4.86E+04
4.05E+04
8.09E+03
3.36E+03
2.02E+06
6.07E+03
9.07E+04
3.24E+03
2.02E+04
4.05E+04
1.01E+05
3.34E+04
3.24E+05
7.45E+03
1.05E+05
3.24E+04
Depth
(m}
-999
1.87
-999
-999
0.53
-999
2.18
6.76
4.46
-999
-999
-999
-999
5.35
1.13
-999
-999
-999
-999
2.05
-999
-999
3.48
-999
0.79
-999
-999
-999
0.81
-999
-999
5.11
-999
-999
-999
-999
-999
5.11
-999
-999
-999
1.28
7.93
2.64
-999
0.97
-999
Soil/GW
Temperature
ro
17.5
12.5
7.5
7.5
12.5
17.5
17.5
12.5
17.5
22.5
22.5
12.5
12.5
12.5
12.5
17.5
17.5
12.5
17.5
12.5
17.5
17.5
12.5
22.5
17.5
22.5
12.5
7.5
12.5
12.5
12.5
12.5
12.5
12.5
7.5
7.5
22.5
12.5
22.5
12.5
7.5
17.5
17.5
17.5
17.5
12.5
17.5
HG
Environment
13
2
13
5
5
12
13
4
12
2
4
2
5
2
2
4
2
12
5
13
1
5
9
12
13
12
1
12
2
12
12
2
2
4
2
2
2
13
4
12
8
4
12
2
12
12
13
Nearest
Climate
Center
36
52
39
10
87
95
34
74
95
36
92
54
56
53
51
81
30
85
54
72
95
12
73
57
37
58
72
53
39
49
71
88
50
74
53
53
58
73
12
42
65
79
85
36
95
88
37
Site
Weiahtina
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
D-10
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
Area
(m2}
2.70E+04
3.24E+05
4.86E+04
3.04E+04
2.43E+04
1.86E+04
1.56E+05
4.86E+05
4.05E+04
2.32E+04
1.66E+05
2.02E+04
1.21E+05
5.46E+04
1.49E+05
1.92E+04
1.82E+04
6.07E+03
1.30E+05
3.44E+04
3.64E+04
5.18E+04
5.26E+04
1.34E+05
5.87E+04
3.52E+05
2.19E+05
7.08E+04
7.32E+04
4.05E+05
3.84E+04
1.75E+04
1.79E+05
8.09E+04
1.84E+05
4.05E+04
2.52E+06
1.21E+05
1.58E+05
1.36E+04
6.88E+03
1.05E+05
7.01 E+04
2.02E+05
1.92E+06
2.43E+04
1.62E+05
Depth
(m}
2.28
1.53
-999
4.58
-999
-999
2.92
0.53
1.31
3.56
-999
-999
0.55
3.54
4.45
1.49
1.27
6.78
-999
-999
1.59
2.56
1.06
6.20
0.56
2.63
-999
-999
-999
0.63
1.94
2.52
2.83
-999
3.15
2.89
1.77
-999
2.35
1.42
3.95
7.87
2.00
-999
0.79
-999
-999
Soil/GW
Temperature
ro
17.5
17.5
12.5
12.5
17.5
12.5
12.5
7.5
12.5
17.5
7.5
12.5
17.5
12.5
7.5
22.5
12.5
12.5
17.5
12.5
12.5
22.5
17.5
7.5
17.5
7.5
22.5
22.5
7.5
22.5
7.5
22.5
12.5
17.5
17.5
17.5
17.5
17.5
7.5
17.5
22.5
22.5
22.5
17.5
17.5
22.5
17.5
HG
Environment
13
4
13
13
13
2
13
2
2
13
13
12
2
4
13
4
8
4
5
7
5
4
4
1
4
1
4
4
4
13
2
12
12
4
12
1
13
4
2
2
12
12
12
12
4
4
4
Nearest
Climate
Center
34
30
68
56
37
51
56
17
51
13
3
69
30
74
50
92
46
74
90
29
24
96
79
44
93
31
92
96
31
81
50
92
69
92
89
95
34
93
31
87
78
78
91
85
93
92
92
Site
Weiahtina
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.00
1.00
1.00
1.00
7.48
7.48
7.48
7.48
7.48
7.48
7.48
7.48
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-11
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
Area
(m2}
1.21E+05
1.82E+05
1.24E+04
1.62E+05
3.72E+05
1.78E+05
8.09E+04
9.31 E+04
1.09E+05
6.56E+04
5.38E+04
1.49E+05
1.46E+05
1.21E+05
1.62E+05
5.80E+04
1.52E+04
2.29E+04
2.02E+03
9.15E+04
8.09E+04
2.53E+04
8.09E+03
2.43E+04
2.38E+04
2.70E+04
1.62E+04
4.86E+04
1.23E+05
2.02E+05
4.05E+04
1.62E+05
1.25E+05
1.21E+05
2.02E+04
6.48E+04
4.33E+04
1.42E+05
6.07E+04
3.72E+05
1.19E+06
6.07E+05
1.21E+05
3.64E+04
1.62E+05
2.02E+04
6.48E+04
Depth
(m)
2.18
0.84
1.94
-999
1.32
4.65
-999
4.66
7.58
3.27
7.38
7.80
1.32
2.38
3.07
2.47
-999
-999
-999
3.62
-999
6.55
2.86
0.83
5.22
-999
2.86
4.33
2.68
-999
3.60
6.14
2.65
2.21
1.15
4.06
3.29
3.04
6.55
-999
2.61
6.34
3.14
2.43
1.23
-999
1.79
Soil/GW
Temperature
ro
7.5
7.5
17.5
17.5
22.5
12.5
12.5
7.5
7.5
7.5
7.5
17.5
17.5
17.5
7.5
22.5
22.5
12.5
12.5
22.5
17.5
12.5
12.5
12.5
12.5
17.5
7.5
7.5
17.5
12.5
12.5
22.5
17.5
17.5
7.5
7.5
22.5
17.5
7.5
17.5
7.5
17.5
12.5
12.5
12.5
7.5
17.5
HG
Environment
4
13
4
2
12
2
2
8
8
2
2
4
4
12
4
4
4
5
4
4
4
13
2
12
2
1
2
1
4
4
8
12
2
4
4
2
4
4
1
4
2
4
4
12
8
1
5
Nearest
Climate
Center
50
43
90
80
78
28
66
41
62
50
50
95
95
95
45
92
92
24
52
96
93
40
40
39
82
85
31
47
89
51
46
91
81
93
25
50
81
80
62
81
50
92
52
54
32
31
89
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-12
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
Area
(m2}
9.96E+04
5.06E+04
1.42E+05
8.09E+04
2.02E+05
2.83E+05
2.02E+04
6.07E+05
1.98E+05
7.28E+05
6.68E+04
4.05E+05
1.35E+04
2.02E+05
5.67E+04
1.62E+05
2.83E+04
1.23E+06
1.62E+05
1.08E+04
2.63E+04
1.92E+04
2.02E+05
3.97E+05
3.37E+04
3.24E+04
1.34E+05
1.21E+05
1.66E+05
5.67E+05
2.37E+04
6.07E+04
8.90E+04
4.86E+04
4.86E+04
3.31 E+04
1.05E+06
1.42E+04
3.24E+05
9.31 E+02
8.09E+03
1.01 E+04
1.38E+04
8.09E+03
1.63E+05
4.86E+02
7.08E+04
Depth
(m}
1.93
0.93
1.17
-999
2.95
5.84
1.23
1.85
1.82
2.73
2.16
0.52
1.43
0.82
4.24
2.86
-999
-999
2.66
-999
2.97
1.49
1.38
5.62
-999
5.16
2.29
2.86
-999
4.09
1.58
4.09
2.10
2.73
4.48
1.71
0.90
4.68
4.09
1.32
-999
0.65
1.06
-999
-999
0.71
5.28
Soil/GW
Temperature
ro
17.5
7.5
17.5
7.5
12.5
7.5
12.5
17.5
22.5
17.5
22.5
12.5
17.5
7.5
12.5
12.5
17.5
17.5
22.5
12.5
7.5
22.5
12.5
12.5
17.5
17.5
7.5
12.5
22.5
17.5
17.5
17.5
17.5
7.5
12.5
17.5
7.5
12.5
7.5
17.5
17.5
12.5
17.5
17.5
22.5
12.5
12.5
HG
Environment
5
4
4
2
1
1
4
5
12
1
12
4
2
2
1
13
1
2
4
2
4
4
8
4
5
4
1
13
12
4
5
4
5
2
1
12
13
12
8
2
12
2
13
12
5
5
9
Nearest
Climate
Center
81
25
81
48
9
44
82
81
78
85
78
74
87
50
63
24
95
80
91
71
50
92
32
66
90
93
31
40
78
95
90
95
90
50
69
92
48
84
32
89
95
4
34
89
21
40
73
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
4.42
4.42
4.42
4.42
4.42
4.42
4.42
4.42
D-13
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
Area
(m2}
1.66E+03
4.05E+03
4.05E+04
2.02E+03
1.78E+05
1.13E+04
4.05E+03
7.49E+04
9.66E+04
5.67E+03
4.05E+04
4.05E+04
1.21E+05
2.02E+04
1.01E+05
4.45E+04
1.54E+04
5.36E+04
7.69E+04
4.05E+04
1.36E+04
1.62E+04
1.13E+04
1.62E+04
8.09E+03
8.09E+03
1.75E+04
8.26E+04
1.62E+04
8.50E+04
2.00E+04
3.04E+05
2.02E+04
1.21E+04
1.30E+05
5.40E+04
9.61 E+04
7.89E+05
2.02E+05
1.06E+04
2.43E+04
2.02E+03
2.02E+03
1.21E+05
1.21E+02
1.82E+04
7.90E+04
Depth
(m}
2.59
-999
8.18
7.39
2.79
2.57
-999
-999
-999
7.95
-999
-999
-999
0.82
-999
4.69
4.55
0.93
1.63
-999
-999
3.58
2.59
-999
2.32
-999
-999
-999
5.11
1.21
-999
0.91
-999
-999
2.56
6.14
-999
3.36
3.27
-999
0.55
-999
-999
-999
0.68
1.36
3.88
Soil/GW
Temperature
ro
22.5
7.5
12.5
12.5
17.5
12.5
17.5
17.5
22.5
12.5
12.5
22.5
7.5
12.5
12.5
12.5
12.5
22.5
17.5
17.5
17.5
12.5
12.5
17.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
22.5
17.5
12.5
12.5
22.5
22.5
17.5
12.5
12.5
12.5
7.5
22.5
22.5
17.5
17.5
22.5
HG
Environment
12
4
8
4
4
1
12
2
4
12
2
2
4
1
5
8
8
2
12
1
2
12
8
4
12
5
5
8
4
4
4
4
1
12
6
12
4
4
2
12
5
4
2
12
4
13
12
Nearest
Climate
Center
58
60
9
40
29
9
89
89
58
73
54
21
43
8
26
46
42
22
89
95
87
49
9
93
72
51
26
8
25
60
20
58
95
54
89
91
58
90
52
71
40
83
22
91
36
13
91
Site
Weiahtina
4.42
4.42
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.36
1.36
1.36
30.19
30.19
30.19
30.19
11.28
11.28
D-14
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
Area
(m2}
1.42E+04
4.05E+04
1.00E+04
7.49E+02
5.26E+04
2.27E+05
2.63E+04
5.46E+04
8.09E+03
1.48E+04
4.98E+03
6.48E+04
4.86E+03
3.89E+05
3.64E+05
2.43E+04
2.32E+04
1.42E+05
4.05E+04
6.07E+04
9.11E+04
2.79E+03
9.31 E+02
2.95E+03
1.62E+05
4.65E+04
8.09E+03
1.67E+04
1.42E+05
3.52E+03
4.69E+03
2.19E+04
1.01E+05
4.05E+03
2.83E+04
1.66E+04
4.05E+03
9.41 E+03
4.05E+03
2.27E+04
2.43E+03
1.38E+03
2.02E+03
8.34E+02
1.62E+04
2.02E+04
8.36E+03
Depth
(m}
3.10
2.05
8.25
0.92
7.40
7.31
-999
3.15
-999
1.67
-999
0.80
-999
1.49
-999
2.73
-999
-999
4.09
-999
-999
-999
-999
3.34
0.87
1.58
-999
3.47
-999
1.96
1.59
-999
1.32
-999
0.88
-999
-999
0.88
1.06
0.99
2.94
-999
-999
3.97
0.99
-999
-999
Soil/GW
Temperature
ro
17.5
12.5
12.5
17.5
17.5
12.5
12.5
12.5
12.5
17.5
17.5
17.5
12.5
22.5
7.5
12.5
22.5
17.5
22.5
12.5
12.5
17.5
17.5
12.5
17.5
12.5
7.5
12.5
22.5
12.5
12.5
17.5
17.5
12.5
22.5
12.5
22.5
12.5
22.5
17.5
22.5
22.5
17.5
17.5
22.5
12.5
7.5
HG
Environment
1
7
6
4
13
6
1
6
5
4
5
1
12
4
2
8
4
2
12
2
13
12
5
2
12
4
2
12
12
4
5
4
5
2
4
12
12
5
4
13
4
4
4
4
4
5
4
Nearest
Climate
Center
77
29
73
23
13
73
5
74
9
89
90
77
87
96
32
83
92
36
93
39
24
85
13
51
85
66
60
87
76
66
3
20
13
69
96
69
92
19
81
37
58
35
81
29
96
27
7
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.37
1.37
1.37
1.37
1.37
24.00
24.00
1.89
1.89
1.89
1.89
1.89
1.89
1.00
1.00
1.00
1.00
1.00
1.27
1.27
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
D-15
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
Area
(m2}
2.43E+04
4.05E+03
1.63E+04
7.28E+04
2.43E+04
4.18E+04
3.64E+04
4.05E+04
3.04E+04
3.04E+05
1.62E+04
3.84E+04
2.02E+03
2.36E+04
6.21 E+02
1.01E+05
1.62E+04
8.09E+04
1.42E+04
4.05E+04
4.05E+03
4.65E+04
3.24E+02
8.09E+03
1.52E+05
5.67E+04
2.48E+03
1.11E+04
2.43E+04
1.66E+05
1.02E+06
1.36E+05
1.21E+04
8.09E+04
3.10E+04
1.62E+04
1.62E+04
2.02E+05
1.01E+05
1.82E+04
6.07E+02
1.82E+04
1.78E+04
4.05E+04
7.90E+04
3.34E+04
3.04E+04
Depth
(m}
-999
3.27
3.38
2.05
1.32
5.74
2.05
0.98
-999
-999
0.85
-999
1.33
1.18
-999
5.73
-999
-999
1.04
-999
2.05
-999
-999
-999
3.27
2.63
-999
-999
1.91
7.98
0.65
-999
1.09
-999
0.94
-999
-999
1.74
-999
2.83
-999
3.00
0.83
2.36
-999
4.46
2.02
Soil/GW
Temperature
ro
17.5
7.5
22.5
12.5
12.5
12.5
22.5
12.5
12.5
22.5
17.5
17.5
17.5
17.5
12.5
12.5
17.5
17.5
12.5
17.5
12.5
12.5
12.5
17.5
7.5
17.5
7.5
12.5
12.5
12.5
12.5
12.5
17.5
12.5
12.5
7.5
17.5
17.5
17.5
12.5
22.5
17.5
12.5
7.5
7.5
12.5
22.5
HG
Environment
5
2
4
12
8
12
4
4
8
4
4
4
4
13
2
12
4
4
5
4
2
5
2
4
13
2
1
2
2
8
5
5
1
12
2
8
2
5
5
5
2
4
2
4
12
9
4
Nearest
Climate
Center
34
31
92
54
46
54
92
74
46
96
23
80
29
29
19
73
95
20
26
93
39
40
52
95
68
30
47
50
71
32
51
34
95
42
52
32
90
13
23
74
36
93
39
60
42
74
96
Site
Weiahtina
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.17
1.17
1.17
1.17
1.17
10.23
10.23
10.23
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.36
1.36
1.36
1.36
1.36
1.36
1.36
1.36
1.36
1.36
1.36
D-16
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.1 Nationwide Database of Landfill Sites
Site
Number
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
Area
(m2}
4.05E+03
3.72E+03
2.43E+04
2.31 E+05
1.86E+04
1.62E+04
1.82E+04
8.09E+04
5.26E+04
4.25E+04
7.69E+03
1.62E+04
5.67E+04
2.63E+05
8.09E+03
3.64E+04
5.95E+04
2.32E+04
1.58E+05
2.83E+04
8.50E+04
1.21 E+05
2.43E+05
1.82E+04
1.62E+04
1.27E+04
6.07E+03
4.29E+04
1.52E+05
1.01E+04
7.97E+03
8.09E+03
8.09E+03
2.43E+05
8.09E+03
1.34E+03
6.48E+04
790 1.21E+04
Depth
(m}
-999
-999
2.14
-999
0.79
1.32
-999
0.53
-999
-999
1.08
2.86
4.38
0.76
1.02
-999
2.27
1.28
-999
-999
2.92
-999
-999
1.24
2.05
3.34
-999
1.48
1.82
3.14
-999
-999
-999
-999
0.82
1.98
1.84
-999
Soil/GW
Temperature
ro
12.5
12.5
12.5
7.5
17.5
12.5
12.5
22.5
22.5
22.5
12.5
12.5
22.5
22.5
17.5
17.5
17.5
17.5
12.5
17.5
22.5
17.5
17.5
17.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
7.5
7.5
7.5
7.5
HG
Environment
2
12
2
2
12
12
13
4
4
4
5
2
12
4
1
4
2
4
4
4
2
4
4
1
12
1
1
12
1
1
4
4
1
12
1
4
8
8
Nearest
Climate
Center
54
49
74
32
89
69
40
96
96
96
51
39
91
96
77
93
93
80
72
80
36
89
93
85
69
79
85
85
85
95
93
79
79
95
31
84
44
62
Site
Weiahtina
1.36
1.36
1.36
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
6.82
6.82
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
3.09
3.09
1.00
1.36
D-17
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Area
(m2)
6.31 E+02
9.39E+03
9.75E+03
2.20E+04
2.93E+04
8.83E+02
5.81 E+03
1.68E+03
2.59E+05
3.60E+05
6.56E+04
4.05E+05
1.25E+05
3.24E+05
6.60E+04
2.59E+05
2.93E+03
2.69E+03
1.67E+04
2.69E+03
5.40E+02
4.05E+03
1.17E+04
4.05E+03
3.72E+04
2.42E+03
3.07E+03
Operating
Depth
(m)
2.13
1.22
2.44
2.44
3.54
0.61
0.61
6.25
0.76
10.97
6.10
5.33
8.53
5.33
8.84
6.10
-999
3.66
3.66
3.66
-999
3.66
3.20
3.66
1.68
1.25
1.83
Base Depth
Below Grade
(m)
0.00
0.00
0.00
0.00
5.98
1.22
1.22
7.32
1.52
9.30
8.53
14.48
2.29
12.04
9.60
7.32
0.00
4.57
4.57
4.57
0.00
4.57
3.81
6.10
8.23
3.94
2.19
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
12.5
17.5
17.5
17.5
17.5
12.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
17.5
17.5
17.5
17.5
22.5
22.5
Distance to
Nearest SW
Body
(m)
110
5000
5000
5000
5000
120
110
900
1450
100
625
75
960
125
775
350
150
1600
1600
1600
5000
5000
5000
5000
5000
20
55
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
50
7
22
42
50
50
50
50
50
50
50
50
50
50
41
23
50
23
50
24
22
Soil
Type
1
1
1
1
1
2
2
3
1
3
3
3
3
3
3
3
3
3
3
3
2
3
3
3
3
3
3
HG
Environment
6
5
5
5
5
10
10
2
1
1
1
1
1
1
1
1
10
10
10
10
8
1
1
1
1
10
10
Nearest
Climate
Center
4
12
12
12
12
72
72
56
85
77
77
77
77
77
77
77
80
91
91
91
42
77
77
77
77
96
96
Site
Weighting
7.02
25.16
25.16
25.16
25.16
22.33
22.33
29.82
7.21
6.81
6.81
6.81
6.81
6.81
6.81
6.81
123.12
238.79
238.79
238.79
21.14
3.61
3.61
3.61
3.61
21.82
21.82
o
00
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Area
(m2)
7.66E+02
1.52E+02
5.81 E+02
2.32E+03
7.90E+03
1.62E+04
1.62E+04
1.21E+04
4.80E+05
1.21E+05
1.49E+05
7.69E+03
1.02E+05
2.00E+03
2.58E+03
2.58E+03
2.53E+03
1.21E+05
2.75E+05
1.11E+06
3.54E+02
4.87E+02
6.07E+03
1.42E+04
Operating
Depth
(m)
2.29
0.76
1.83
1.52
0.61
3.51
3.51
4.27
4.80
6.10
4.57
4.27
4.57
1.07
2.44
2.44
2.74
3.12
-999
0.34
-999
0.68
4.18
1.52
Base Depth
Below Grade
(m)
2.29
1.37
0.00
2.44
1.52
1.95
1.95
1.37
1.30
1.68
0.00
0.46
2.59
0.61
1.07
1.07
1.07
0.00
0.00
0.00
0.00
0.00
3.87
0.00
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
22.5
22.5
17.5
12.5
12.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
7.5
7.5
7.5
7.5
17.5
17.5
17.5
12.5
12.5
12.5
12.5
Distance to
Nearest SW
Body
(m)
5000
5000
190
115
40
5000
5000
410
90
50
65
65
65
120
130
145
145
85
300
85
20
20
695
330
Operating
Life/Leaching
Duration
(yr)
47
17
50
50
27
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Soil
Type
1
1
1
1
3
3
3
3
3
3
3
3
3
1
1
1
1
1
1
1
1
1
3
3
HG
Environment
10
10
6
2
2
10
10
6
6
6
6
6
6
7
7
7
7
7
7
7
2
2
9
9
Nearest
Climate
Center
81
81
34
42
42
96
96
54
54
54
54
54
54
66
66
66
66
91
91
91
71
71
49
49
Site
Weighting
25.05
25.05
28.76
117.25
117.25
1.01
1.01
1.70
1.70
1.70
1.70
1.70
1.70
7.21
7.21
7.21
7.21
1.01
1.01
1.01
7.02
7.02
23.04
23.04
o
CO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
Area
(m2)
6.07E+03
1.42E+04
1.35E+03
1.35E+03
2.02E+04
6.06E+03
6.04E+03
4.05E+05
1.01E+06
1.62E+03
2.02E+02
6.97E+02
1.04E+03
1.49E+03
1.39E+02
1.23E+03
2.79E+01
5.06E+04
1.62E+03
1.62E+03
4.86E+03
4.86E+03
1.82E+04
Operating
Depth
(m)
4.18
3.66
3.66
3.66
4.13
1.52
1.63
2.43
2.58
2.28
2.74
2.28
0.03
1.22
0.30
1.47
0.61
1.49
0.46
1.74
0.46
-999
1.07
Base Depth
Below Grade
(m)
3.87
1.83
1.83
1.83
3.61
0.40
0.38
0.00
0.00
0.00
0.00
5.72
0.52
1.83
1.98
0.00
0.00
3.63
2.74
0.61
6.10
4.45
3.51
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
12.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
12.5
12.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
Distance to
Nearest SW
Body
(m)
710
620
575
590
530
20
60
25
25
5000
5000
20
1520
20
20
90
140
1200
1100
750
930
1600
1700
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
50
50
50
57
50
50
50
31
50
5
50
50
55
55
65
65
65
Soil
Type
3
3
3
3
3
2
2
3
3
3
3
1
2
3
3
3
3
1
1
1
1
1
1
HG
Environment
9
9
9
9
9
6
6
7
7
7
7
2
4
12
12
12
12
10
10
10
10
10
10
Nearest
Climate
Center
49
49
49
49
49
25
25
54
54
54
54
39
78
6
6
6
6
93
93
93
93
93
93
Site
Weighting
23.04
23.04
23.04
23.04
23.04
7.67
7.67
7.02
7.02
7.02
7.02
21.25
26.72
23.20
23.20
23.20
23.20
7.27
7.27
7.27
7.27
7.27
7.27
o
rb
o
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
Area
(m2)
4.05E+03
1.86E+03
6.99E+03
9.68E+03
5.26E+04
4.45E+04
9.31 E+03
5.30E+03
5.23E+03
4.46E+03
3.57E+03
8.88E+03
8.76E+03
4.06E+03
1.74E+05
1.29E+05
1.86E+04
1.53E+03
2.63E+05
1.94E+04
1.62E+04
3.48E+04
1.21 E+03
Operating
Depth
(m)
1.98
-999
1.31
1.07
3.89
4.43
1.37
2.18
4.57
3.05
0.61
4.27
3.05
2.13
4.55
2.26
3.35
1.37
0.30
3.05
4.05
3.05
3.12
Base Depth
Below Grade
(m)
2.59
0.00
2.23
8.08
2.44
1.83
2.44
0.91
2.74
1.22
1.52
2.74
3.05
1.52
3.51
1.07
4.27
2.90
1.07
3.66
5.18
3.66
3.66
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
17.5
17.5
17.5
17.5
17.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
Distance to
Nearest SW
Body
(m)
5000
5000
700
1100
5000
1900
700
5000
5000
5000
5000
5000
5000
5000
200
50
255
180
1220
5000
5000
5000
5000
Operating
Life/Leaching
Duration
(yr)
50
5
50
50
36
35
65
16
50
50
50
50
50
50
50
50
32
27
50
50
50
50
50
Soil
Type
1
1
1
1
1
1
1
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
HG
Environment
10
10
10
10
10
10
10
4
4
4
4
4
4
4
6
6
7
7
10
10
10
10
10
Nearest
Climate
Center
93
93
93
93
93
93
93
48
48
48
48
48
48
48
96
96
90
90
89
89
89
89
89
Site
Weighting
7.27
7.27
7.27
7.27
7.27
7.27
7.27
7.67
7.67
7.67
7.67
7.67
7.67
7.67
6.81
6.81
7.21
7.21
6.81
6.81
6.81
6.81
6.81
o
rb
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
Area
(m2)
1.21E+03
8.58E+05
6.11E+04
2.67E+04
6.07E+04
1.01E+04
6.14E+04
1.54E+05
6.19E+04
8.09E+04
2.30E+02
2.09E+03
2.02E+05
8.09E+03
8.09E+03
4.86E+04
8.09E+03
2.31 E+04
2.02E+05
6.48E+03
1.70E+05
1.01E+03
2.43E+04
Operating
Depth
(m)
5.49
1.52
4.57
3.05
5.11
4.49
1.83
4.57
5.44
-999
3.35
1.53
2.29
2.44
2.74
2.74
2.44
3.05
5.18
4.85
4.57
2.44
4.57
Base Depth
Below Grade
(m)
3.05
1.52
5.94
0.30
4.88
5.18
3.05
1.83
6.48
1.07
3.05
0.00
2.90
3.05
2.13
3.66
3.35
3.96
5.49
0.00
6.71
2.74
4.88
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
Distance to
Nearest SW
Body
(m)
0
1550
1020
1380
1900
5000
1620
1100
1960
240
180
800
140
975
895
910
950
845
25
360
500
270
820
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
50
50
50
50
27
50
50
50
50
50
50
50
50
50
50
50
50
Soil
Type
1
3
3
3
3
3
3
3
3
1
1
2
1
1
1
1
1
1
1
1
1
1
1
HG
Environment
10
10
10
10
10
10
10
10
10
10
6
2
10
10
10
10
10
10
10
10
10
10
10
Nearest
Climate
Center
89
89
89
89
89
89
89
89
89
81
39
71
93
93
93
93
93
93
93
93
93
93
93
Site
Weighting
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
21.82
23.20
29.06
3.40
3.40
3.40
3.40
3.40
3.40
3.40
3.40
3.40
3.40
3.40
o
rb
IV)
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
Area
(m2)
1.39E+03
1.39E+03
5.57E+03
5.57E+02
4.06E+03
2.83E+04
1.01E+04
1.42E+04
8.09E+03
2.02E+04
2.83E+03
7.43E+01
2.86E+05
1.30E+05
7.49E+04
5.26E+03
4.73E+04
7.49E+04
3.68E+04
5.02E+02
1.19E+04
1.39E+03
4.61 E+03
Operating
Depth
(m)
3.05
4.57
4.57
3.81
3.68
-999
0.30
0.30
3.35
0.91
1.73
1.52
1.22
1.67
1.98
1.60
0.76
2.74
1.37
1.07
1.45
1.22
0.15
Base Depth
Below Grade
(m)
3.12
5.49
5.49
4.66
4.66
1.52
6.10
3.20
1.98
3.96
3.35
2.44
0.00
0.00
0.30
2.44
1.83
0.00
1.83
0.00
1.22
2.74
1.83
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
22.5
22.5
7.5
7.5
7.5
7.5
7.5
17.5
17.5
17.5
17.5
Distance to
Nearest SW
Body
(m)
180
230
265
230
270
180
605
590
320
180
330
1800
150
280
30
290
30
30
30
455
160
340
950
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
50
50
50
50
50
13
50
52
60
60
60
60
60
30
50
50
50
Soil
Type
3
3
3
3
3
1
1
1
1
1
1
3
2
1
2
2
2
2
2
1
1
3
3
HG
Environment
6
6
6
6
6
4
4
4
4
4
4
2
10
10
8
8
8
8
8
5
2
2
2
Nearest
Climate
Center
6
6
6
6
6
46
46
46
46
46
46
69
92
96
42
42
42
42
42
13
90
90
90
Site
Weighting
7.21
7.21
7.21
7.21
7.21
7.67
7.67
7.67
7.67
7.67
7.67
21.54
6.81
21.43
3.61
3.61
3.61
3.61
3.61
21.25
6.81
6.81
6.81
IV)
CO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
Area
(m2)
8.71 E+02
5.96E+04
1.33E+03
3.43E+03
1.45E+05
6.01 E+03
5.30E+02
1.30E+02
7.80E+02
7.80E+02
9.14E+02
2.93E+03
2.69E+03
1.99E+03
2.28E+03
1.36E+03
8.38E+03
3.48E+03
8.09E+05
2.38E+01
1.38E+03
1.39E+03
2.06E+02
Operating
Depth
(m)
1.52
4.57
1.52
1.52
2.29
1.52
1.22
1.22
1.22
1.22
-999
1.52
1.52
-999
-999
1.68
4.57
2.29
3.05
4.57
4.57
0.61
0.76
Base Depth
Below Grade
(m)
2.44
5.49
5.49
3.51
2.29
3.66
1.22
1.22
1.22
1.22
0.30
2.44
2.44
1.52
1.52
1.68
6.10
4.42
0.00
4.88
3.05
3.66
1.37
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
17.5
17.5
17.5
17.5
7.5
7.5
7.5
7.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
22.5
22.5
17.5
Distance to
Nearest SW
Body
(m)
560
470
480
600
100
700
110
20
110
110
20
1300
1330
1480
1455
1450
1180
5000
1500
1575
1270
1340
95
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
20
27
20
20
15
50
50
17
17
50
50
50
50
4
50
50
50
Soil
Type
3
3
3
3
3
1
2
2
2
2
2
3
3
3
3
3
3
3
3
1
3
3
3
HG
Environment
2
2
2
2
2
2
9
9
9
9
8
2
2
2
2
12
12
12
6
7
10
10
10
Nearest
Climate
Center
90
90
90
90
90
90
49
49
49
49
59
37
37
37
37
89
89
89
81
81
96
96
80
Site
Weighting
6.81
6.81
6.81
6.81
6.81
6.81
20.59
20.59
20.59
20.59
7.02
19.70
19.70
19.70
19.70
7.39
7.39
7.39
6.81
23.36
3.61
3.61
26.72
o
rb
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
Area
(m2)
5.26E+02
2.02E+03
2.63E+04
6.07E+03
7.08E+05
2.83E+05
4.25E+05
3.64E+04
1.50E+04
1.13E+04
1.13E+04
5.55E+03
3.33E+03
5.14E+05
5.06E+03
7.28E+03
4.05E+05
6.07E+04
1.21E+04
1.21E+04
2.14E+05
1.21E+04
2.43E+05
Operating
Depth
(m)
0.64
2.44
-999
0.58
1.22
0.91
1.37
2.44
1.98
-999
-999
-999
-999
2.74
1.37
0.84
1.14
1.70
4.11
5.26
3.21
5.49
4.57
Base Depth
Below Grade
(m)
0.00
3.05
4.42
1.22
2.44
1.83
2.29
3.05
0.30
0.00
0.00
2.13
1.98
3.96
2.13
2.06
4.50
4.11
5.18
6.02
3.96
6.10
5.18
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
Distance to
Nearest SW
Body
(m)
20
20
215
1645
35
35
35
20
1440
20
30
1800
2000
5000
5000
1500
5000
5000
5000
5000
475
60
40
Operating
Life/Leaching
Duration
(yr)
65
65
50
50
50
50
50
50
50
47
47
50
50
50
50
50
50
22
50
50
47
50
50
Soil
Type
1
3
3
3
3
3
3
3
3
1
1
1
1
3
3
3
3
3
3
3
3
1
1
HG
Environment
2
2
10
10
10
10
10
10
10
1
1
2
2
6
6
6
6
6
6
6
6
4
4
Nearest
Climate
Center
15
15
96
96
96
96
96
96
96
85
85
6
6
90
90
90
90
90
90
90
90
46
46
Site
Weighting
1.01
1.01
7.67
7.67
7.67
7.67
7.67
7.67
7.67
11.83
11.83
11.52
11.52
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
o
rb
01
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
Area
(m2)
4.05E+04
6.27E+04
3.04E+04
2.67E+04
9.29E+03
1.45E+03
5.38E+03
5.38E+03
8.99E+02
8.99E+02
1.19E+03
6.07E+03
2.20E+03
1.19E+03
8.36E+03
4.49E+04
1.41E+03
3.18E+03
1.76E+03
1.19E+03
4.41 E+03
1.30E+04
8.82E+03
Operating
Depth
(m)
3.51
5.05
-999
-999
1.37
2.26
2.77
2.77
1.83
1.83
3.66
1.37
3.96
3.66
1.52
1.22
3.49
3.57
1.68
3.66
2.16
1.71
0.30
Base Depth
Below Grade
(m)
0.00
9.51
4.72
5.64
3.96
2.44
3.66
3.96
3.66
3.66
5.03
2.29
4.72
5.03
3.35
1.07
3.89
3.96
1.72
5.03
0.61
1.92
0.30
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
12.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
22.5
Distance to
Nearest SW
Body
(m)
90
150
330
315
1700
1600
1260
1140
1080
1080
395
130
395
395
500
550
480
480
660
395
850
695
150
Operating
Life/Leaching
Duration
(yr)
50
50
16
16
24
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
65
8
50
Soil
Type
2
2
2
2
3
3
3
3
3
3
1
1
1
1
1
1
1
1
1
1
3
3
2
HG
Environment
5
4
4
4
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
2
2
11
Nearest
Climate
Center
82
76
76
76
92
92
92
92
92
92
79
79
79
79
79
79
79
79
79
79
73
73
94
Site
Weighting
6.81
7.21
7.21
7.21
23.20
23.20
23.20
23.20
23.20
23.20
7.21
7.21
7.21
7.21
7.21
7.21
7.21
7.21
7.21
7.21
21.82
21.82
26.72
o
rb
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
Area
(m2)
8.76E+03
2.02E+05
1.21E+03
2.02E+03
4.69E+05
2.02E+05
1.55E+03
2.68E+03
2.21 E+03
3.19E+03
1.90E+03
1.90E+03
3.24E+04
3.24E+04
3.16E+04
2.79E+03
2.87E+04
5.04E+03
5.04E+03
2.18E+04
9.29E+02
2.37E+04
2.42E+03
Operating
Depth
(m)
0.30
3.66
1.83
-999
2.97
3.66
1.10
2.13
3.05
2.13
3.05
3.05
1.37
1.98
5.33
3.96
1.37
3.66
3.66
1.68
1.83
1.83
1.68
Base Depth
Below Grade
(m)
0.30
2.13
3.66
0.00
2.67
2.13
2.74
1.83
3.66
0.00
3.66
3.66
0.15
0.61
2.13
5.79
2.74
0.00
0.00
3.05
0.91
1.22
2.35
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
22.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
27.5
27.5
27.5
27.5
7.5
7.5
7.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
17.5
Distance to
Nearest SW
Body
(m)
90
335
600
65
115
435
270
270
1800
656
1800
1800
850
755
320
320
1580
1500
1560
1750
505
505
350
Operating
Life/Leaching
Duration
(yr)
50
50
30
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
18
50
50
Soil
Type
2
2
2
1
1
2
2
2
3
3
3
3
3
2
2
3
1
1
1
1
3
3
1
HG
Environment
11
10
10
10
10
10
7
7
6
6
6
6
9
9
9
12
12
12
12
12
10
10
2
Nearest
Climate
Center
94
80
80
80
80
80
66
66
102
102
102
102
62
62
62
89
89
89
89
89
92
92
15
Site
Weighting
26.72
3.40
3.40
3.40
3.40
3.40
117.25
117.25
7.67
7.67
7.67
7.67
6.81
6.81
6.81
21.25
21.25
21.25
21.25
21.25
7.67
7.67
23.20
o
rb
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
Area
(m2)
2.98E+04
2.83E+03
3.12E+04
6.07E+03
4.86E+03
6.48E+03
1.07E+04
2.36E+03
1.62E+04
3.12E+01
5.20E+01
1.42E+03
1.21E+04
1.21E+04
1.80E+05
6.61 E+03
7.93E+04
4.82E+05
1.92E+04
1.92E+04
5.67E+03
5.67E+03
1.37E+04
Operating
Depth
(m)
0.88
1.89
2.07
0.81
1.01
1.11
2.06
1.86
3.81
1.22
0.24
3.45
1.22
0.30
-999
5.64
3.05
1.22
3.05
3.05
0.15
0.38
-999
Base Depth
Below Grade
(m)
3.26
2.26
2.83
0.00
0.00
0.00
2.06
2.53
4.57
0.00
0.28
5.18
1.98
0.91
0.00
0.00
3.81
2.29
4.27
4.27
1.68
1.91
0.00
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
22.5
12.5
7.5
7.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
Distance to
Nearest SW
Body
(m)
400
350
350
580
580
580
350
350
200
30
5000
30
75
25
95
720
565
670
40
40
5000
5000
60
Operating
Life/Leaching
Duration
(yr)
50
50
50
57
55
55
50
50
50
12
7
50
50
50
50
50
50
50
50
50
37
37
50
Soil
Type
1
1
1
1
1
1
1
1
1
2
2
3
2
2
1
2
1
2
2
2
3
3
3
HG
Environment
2
2
2
2
2
2
2
2
1
4
4
9
4
4
10
10
10
10
10
10
10
10
10
Nearest
Climate
Center
15
15
15
15
15
15
15
15
69
46
57
39
42
42
91
91
91
91
91
91
96
96
96
Site
Weighting
23.20
23.20
23.20
23.20
23.20
23.20
23.20
23.20
26.72
26.72
63.12
21.25
3.40
3.40
6.81
6.81
6.81
6.81
6.81
6.81
7.21
7.21
1.01
IV)
00
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
Area
(m2)
1.86E+05
2.16E+05
1.57E+05
1.12E+05
1.09E+05
1.70E+05
4.74E+02
2.01 E+03
2.01 E+03
4.01 E+02
9.17E+01
2.60E+01
4.01 E+02
4.01 E+02
3.52E+04
4.05E+03
1.62E+04
1.78E+04
3.67E+03
4.30E+03
6.31 E+03
2.02E+04
9.30E+00
Operating
Depth
(m)
0.63
-999
-999
-999
2.11
-999
2.13
1.83
1.83
-999
-999
-999
-999
-999
2.05
2.12
4.39
0.91
3.05
4.21
2.50
-999
1.83
Base Depth
Below Grade
(m)
0.00
0.00
0.00
0.00
0.00
0.00
4.57
3.05
3.05
0.00
0.00
0.00
0.00
0.00
2.90
3.58
6.16
1.83
1.52
7.92
5.79
0.00
3.05
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
22.5
22.5
22.5
22.5
22.5
22.5
17.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
17.5
17.5
7.5
12.5
12.5
12.5
12.5
Distance to
Nearest SW
Body
(m)
250
85
385
700
710
240
180
5000
5000
360
360
360
360
360
400
350
5000
5000
140
1260
1260
1260
130
Operating
Life/Leaching
Duration
(yr)
95
50
50
50
75
50
50
50
50
50
50
50
50
50
50
50
50
27
37
47
50
50
14
Soil
Type
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
2
1
1
1
1
2
HG
Environment
10
10
10
10
10
10
10
10
10
2
2
2
2
2
5
5
5
5
6
12
12
12
8
Nearest
Climate
Center
96
96
96
96
96
96
93
58
58
34
34
34
34
34
24
24
20
20
25
73
73
73
61
Site
Weighting
1.01
1.01
1.01
1.01
1.01
1.01
7.21
7.39
7.39
229.99
229.99
229.99
229.99
229.99
117.97
117.97
7.02
7.02
7.67
21.25
21.25
21.25
21.25
o
rb
CO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
Area
(m2)
5.89E+04
5.65E+04
1.69E+04
4.58E+04
1.17E+04
2.02E+03
6.07E+03
1.68E+05
2.84E+03
7.53E+02
1.33E+05
6.97E+03
4.46E+03
1.34E+04
3.67E+02
2.47E+04
8.63E+04
1.01E+03
7.28E+04
5.26E+04
5.34E+03
8.90E+03
5.50E+03
Operating
Depth
(m)
3.35
3.35
4.27
1.83
1.98
-999
-999
6.25
1.37
0.93
4.27
2.39
3.84
3.20
1.42
3.83
5.48
3.25
0.50
1.29
0.91
5.49
3.44
Base Depth
Below Grade
(m)
4.57
4.57
0.00
3.66
3.66
1.07
1.07
5.33
1.83
0.00
3.35
0.00
5.18
0.00
0.61
3.81
3.35
2.97
1.46
2.74
4.27
3.35
0.00
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
12.5
12.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
17.5
17.5
12.5
12.5
7.5
7.5
7.5
7.5
7.5
7.5
17.5
17.5
Distance to
Nearest SW
Body
(m)
310
110
1480
1620
190
190
180
1360
20
20
1040
1220
1510
220
50
240
130
40
5000
5000
455
710
950
Operating
Life/Leaching
Duration
(yr)
50
47
50
50
50
50
65
50
50
50
50
50
50
50
50
50
50
50
30
50
50
18
50
Soil
Type
3
3
1
1
1
1
1
1
1
1
1
3
3
2
2
2
2
2
3
3
3
1
1
HG
Environment
6
6
9
9
9
9
9
9
9
9
9
6
6
7
4
9
9
9
9
9
9
10
10
Nearest
Climate
Center
6
6
44
44
44
44
44
44
44
44
44
90
90
66
86
44
44
43
43
43
43
81
81
Site
Weighting
7.21
7.21
38.99
38.99
38.99
38.99
38.99
38.99
38.99
38.99
38.99
7.86
7.86
10.30
29.82
6.81
6.81
7.02
7.02
7.02
7.02
6.81
6.81
CO
o
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
Area
(m2)
3.69E+03
2.79E+05
2.47E+05
4.86E+06
3.64E+04
9.71 E+03
1.21E+04
2.47E+05
1.76E+03
3.59E+03
3.26E+03
3.52E+03
5.07E+02
1.00E+03
1.28E+03
1.17E+05
1.32E+03
1.11 E+03
9.96E+02
1.23E+03
8.36E+01
9.29E+01
1.24E+03
Operating
Depth
(m)
4.65
1.22
3.05
2.44
1.52
2.74
1.01
4.57
1.83
1.22
1.68
-999
2.44
-999
-999
2.74
2.08
1.27
5.49
0.91
-999
-999
0.91
Base Depth
Below Grade
(m)
4.53
0.00
2.13
0.00
0.61
0.00
0.79
0.46
0.00
0.00
0.76
0.91
2.44
2.44
2.04
3.66
1.99
0.61
6.10
1.22
6.10
6.10
1.22
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
17.5
17.5
17.5
17.5
17.5
17.5
Distance to
Nearest SW
Body
(m)
1100
905
1100
125
720
1500
950
1540
460
480
500
60
75
20
20
5000
75
90
190
5000
5000
5000
5000
Operating
Life/Leaching
Duration
(yr)
50
22
50
50
50
50
50
50
50
50
50
22
50
22
22
50
50
24
47
50
50
50
50
Soil
Type
1
3
1
3
1
1
1
3
1
1
1
3
3
3
3
3
3
3
2
1
1
1
1
HG
Environment
10
10
10
10
10
10
10
10
4
4
4
7
7
7
7
7
7
2
5
2
2
2
2
Nearest
Climate
Center
81
81
81
81
81
81
81
81
100
100
100
10
10
10
10
10
10
89
12
95
95
95
95
Site
Weighting
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
36.31
36.31
36.31
7.67
7.67
7.67
7.67
7.67
7.67
7.27
7.21
23.04
23.04
23.04
23.04
o
CO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
Area
(m2)
7.43E+02
1.23E+03
1.24E+03
2.92E+03
2.92E+03
5.34E+02
2.42E+03
1.67E+03
2.92E+03
2.79E+04
3.72E+04
3.72E+04
2.79E+04
6.97E+04
2.14E+04
2.33E+03
1.77E+03
3.04E+03
1.03E+03
7.24E+02
3.90E+02
8.90E+03
3.90E+03
Operating
Depth
(m)
-999
3.35
-999
4.27
4.27
0.19
1.22
0.30
4.27
13.72
7.47
8.69
6.10
0.38
3.05
2.97
3.58
1.83
-999
-999
0.07
1.07
2.13
Base Depth
Below Grade
(m)
1.07
3.96
1.98
2.44
2.44
1.22
2.90
1.22
2.44
33.53
4.57
5.79
3.66
6.40
4.57
3.05
3.66
2.74
7.62
4.57
0.00
8.08
3.84
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
12.5
12.5
12.5
12.5
12.5
22.5
12.5
12.5
17.5
12.5
12.5
22.5
12.5
17.5
Distance to
Nearest SW
Body
(m)
150
340
120
90
90
1330
130
190
20
1315
40
230
330
65
370
1080
1000
700
260
240
260
440
85
Operating
Life/Leaching
Duration
(yr)
50
50
50
7
7
50
17
17
7
50
50
50
50
50
75
50
50
50
50
50
50
17
50
Soil
Type
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
2
2
3
3
2
1
2
HG
Environment
6
10
6
10
10
6
10
10
10
6
6
6
6
6
10
10
10
10
9
9
10
2
2
Nearest
Climate
Center
96
96
96
96
96
96
96
96
96
51
51
51
51
51
96
71
71
71
56
56
92
39
13
Site
Weighting
3.61
3.61
3.61
3.61
3.61
3.61
3.61
3.61
3.61
21.25
21.25
21.25
21.25
21.25
1.01
64.39
64.39
29.82
127.91
127.91
229.99
5.31
22.33
o
CO
IV)
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
Area
(m2)
4.07E+04
2.18E+04
1.16E+03
2.92E+03
2.02E+04
4.86E+04
4.86E+04
4.86E+04
4.86E+04
2.83E+04
3.84E+04
4.86E+04
8.09E+03
4.05E+03
2.23E+04
1.62E+04
2.83E+04
7.73E+05
7.47E+03
2.02E+04
4.86E+04
3.48E+05
4.86E+04
Operating
Depth
(m)
3.66
3.81
-999
-999
2.44
11.46
11.46
11.46
11.46
3.66
2.44
11.46
9.07
18.15
3.30
1.83
3.05
3.66
4.02
3.66
11.46
3.35
11.46
Base Depth
Below Grade
(m)
1.71
2.01
0.00
0.00
1.52
7.47
7.47
7.47
7.47
4.88
1.52
7.47
0.00
0.00
0.00
2.44
3.35
0.00
5.37
4.88
7.47
0.30
7.47
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
17.5
7.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
Distance to
Nearest SW
Body
(m)
840
1120
590
330
1115
1115
1100
970
1360
220
960
1400
240
410
505
1295
635
295
395
255
1650
115
1380
Operating
Life/Leaching
Duration
(yr)
50
22
13
27
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Soil
Type
1
1
3
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
HG
Environment
10
10
1
9
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
Nearest
Climate
Center
6
6
79
66
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
Site
Weighting
3.61
3.61
137.50
7.02
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
o
CO
GO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
Area
(m2)
2.43E+04
4.05E+04
4.86E+04
4.86E+04
4.86E+04
4.86E+04
4.86E+04
2.14E+05
1.62E+03
1.62E+03
1.62E+05
1.21E+04
5.26E+03
5.26E+03
5.26E+04
1.83E+04
2.15E+04
1.70E+03
8.09E+03
9.71 E+02
1.58E+05
7.69E+04
6.84E+05
Operating
Depth
(m)
3.05
4.86
11.46
11.46
5.18
11.46
11.46
2.90
-999
-999
-999
-999
-999
-999
-999
0.38
0.87
1.78
1.68
2.44
1.98
2.44
1.22
Base Depth
Below Grade
(m)
4.27
7.47
7.47
7.47
0.61
7.47
7.47
3.35
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.60
1.55
1.25
4.18
0.00
2.13
3.54
2.56
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
Distance to
Nearest SW
Body
(m)
495
815
985
1155
1380
1500
1540
40
40
110
5000
340
200
200
410
1075
1100
1125
485
120
215
20
405
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Soil
Type
2
2
2
2
2
2
2
2
1
1
1
1
1
2
1
1
1
1
3
3
3
3
1
HG
Environment
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
6
6
6
10
10
10
10
10
Nearest
Climate
Center
78
78
78
78
78
78
78
78
13
13
13
13
13
13
13
56
56
56
80
80
80
80
80
Site
Weighting
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
19.70
19.70
19.70
19.70
19.70
19.70
19.70
38.75
38.75
38.75
3.40
3.40
3.40
3.40
3.40
o
CO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
Area
(m2)
1.58E+05
8.09E+03
2.67E+05
1.21E+04
5.11E+03
5.11E+03
5.11E+03
1.84E+04
2.07E+04
4.37E+05
5.26E+04
7.53E+03
2.95E+05
1.16E+03
7.29E+03
1.86E+03
9.80E+00
4.65E+03
1.86E+04
1.86E+04
7.28E+04
2.38E+04
2.38E+04
Operating
Depth
(m)
4.88
1.68
3.66
1.68
2.13
1.83
0.61
6.72
1.22
1.28
0.77
1.52
0.58
1.83
2.29
-999
1.14
1.76
2.13
2.29
16.11
4.27
4.27
Base Depth
Below Grade
(m)
2.07
4.48
2.99
4.39
3.05
3.05
3.05
0.00
2.13
0.09
0.00
1.83
1.40
2.44
6.55
2.59
2.29
3.96
3.66
3.81
0.00
2.90
2.90
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
17.5
17.5
7.5
7.5
7.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
12.5
17.5
12.5
12.5
12.5
22.5
7.5
7.5
Distance to
Nearest SW
Body
(m)
1350
350
245
40
70
80
80
370
445
60
460
445
30
360
140
130
60
185
220
220
40
1180
1170
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
50
50
50
50
50
50
50
5
37
20
50
50
50
50
50
50
50
Soil
Type
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
2
2
HG
Environment
10
10
10
10
4
4
4
2
2
2
2
2
2
7
7
7
1
9
9
9
4
8
8
Nearest
Climate
Center
80
80
80
80
42
42
42
15
15
15
15
15
15
89
89
89
77
42
42
42
76
31
31
Site
Weighting
3.40
3.40
3.40
3.40
6.81
6.81
6.81
7.67
7.67
7.67
7.67
7.67
7.67
38.75
38.75
38.75
10.91
7.67
7.67
7.67
3.61
29.82
29.82
o
CO
01
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
Area
(m2)
1.77E+03
1.63E+03
1.95E+03
3.72E+03
2.91 E+04
2.91 E+04
1.30E+03
1.77E+04
5.57E+02
1.94E+02
1.30E+03
6.69E+02
2.91 E+04
3.86E+03
4.65E+05
2.31 E+05
1.01E+05
6.96E+03
6.96E+03
7.81 E+03
5.95E+03
1.63E+03
2.69E+03
Operating
Depth
(m)
2.13
1.68
1.22
1.95
-999
3.05
-999
0.94
2.04
1.91
-999
0.46
3.66
1.83
2.74
4.57
4.57
5.18
5.18
2.44
1.27
2.07
1.89
Base Depth
Below Grade
(m)
3.05
2.59
2.74
3.32
3.05
3.05
0.00
2.44
0.00
1.78
0.00
0.00
2.74
7.32
2.44
4.57
3.96
3.81
3.81
0.00
0.00
0.00
0.00
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
12.5
12.5
12.5
12.5
17.5
17.5
7.5
17.5
17.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
7.5
7.5
7.5
7.5
Distance to
Nearest SW
Body
(m)
20
20
40
40
5000
5000
300
5000
5000
40
170
810
1115
575
105
270
795
565
525
900
550
300
300
Operating
Life/Leaching
Duration
(yr)
29
29
29
29
32
32
15
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Soil
Type
2
2
2
2
3
3
1
1
1
1
1
3
3
3
3
3
3
3
3
2
2
2
2
HG
Environment
7
7
7
7
5
5
5
6
6
2
2
12
12
12
12
12
12
12
12
4
6
6
6
Nearest
Climate
Center
84
84
84
84
13
13
3
90
90
39
39
89
89
89
89
89
89
89
89
98
25
25
25
Site
Weighting
6.81
6.81
6.81
6.81
28.76
28.76
164.74
117.25
117.25
23.36
23.36
6.81
6.81
6.81
6.81
6.81
6.81
6.81
6.81
7.67
7.67
7.67
7.67
o
CO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
Area
(m2)
1.74E+02
6.09E+02
1.21E+03
1.39E+04
1.78E+03
2.01 E+03
3.58E+03
3.09E+03
1.24E+03
1.24E+03
1.39E+04
1.74E+03
6.88E+03
2.85E+02
2.86E+02
2.36E+05
7.70E+03
2.88E+04
1.35E+05
5.71 E+04
5.32E+05
6.19E+04
2.16E+05
Operating
Depth
(m)
0.46
0.15
1.83
4.26
2.74
1.83
0.30
1.30
1.45
0.02
3.89
2.74
2.44
1.30
1.81
0.91
-999
-999
0.91
0.91
0.91
0.91
0.91
Base Depth
Below Grade
(m)
1.52
1.07
2.44
3.67
3.05
1.53
3.90
0.00
0.00
0.00
3.38
3.05
2.51
4.18
4.18
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
17.5
17.5
27.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
Distance to
Nearest SW
Body
(m)
420
420
550
210
610
670
440
500
40
30
320
600
280
280
280
300
700
0
0
40
20
20
200
Operating
Life/Leaching
Duration
(yr)
14
14
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Soil
Type
3
3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
HG
Environment
2
2
6
10
10
10
10
10
10
10
10
10
10
10
10
4
4
4
4
4
4
4
4
Nearest
Climate
Center
95
95
102
72
72
72
72
72
72
72
72
72
72
72
72
76
76
76
76
76
76
76
76
Site
Weighting
216.36
216.36
7.21
117.25
117.25
117.25
117.25
117.25
117.25
117.25
117.25
117.25
117.25
123.57
123.57
3.61
3.61
3.61
3.61
3.61
3.61
3.61
3.61
o
CO
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
Area
(m2)
1.01E+05
8.10E+04
6.13E+02
2.02E+02
2.31 E+05
5.30E+03
4.27E+03
5.64E+03
4.16E+03
2.79E+03
6.04E+02
9.75E+03
1.86E+03
1.02E+03
8.36E+02
7.04E+03
4.06E+04
7.28E+02
1.09E+03
2.31 E+03
6.42E+02
3.93E+04
1.46E+03
Operating
Depth
(m)
1.29
-999
3.10
-999
-999
0.61
0.61
1.83
0.61
4.54
1.22
0.30
1.77
0.73
0.01
0.76
2.44
0.30
0.15
0.61
1.43
0.61
3.05
Base Depth
Below Grade
(m)
0.00
0.00
4.63
0.00
0.00
0.15
1.83
1.83
1.86
0.27
0.46
0.46
0.30
0.27
0.00
2.29
3.96
0.61
1.52
4.27
0.91
1.22
5.18
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
22.5
22.5
17.5
12.5
12.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
Distance to
Nearest SW
Body
(m)
5000
0
190
395
65
600
800
840
740
640
640
440
500
530
5000
220
240
800
740
600
216
1220
900
Operating
Life/Leaching
Duration
(yr)
50
50
50
27
38
50
50
50
50
50
50
50
50
50
17
50
50
50
50
50
50
50
50
Soil
Type
2
2
3
1
2
2
2
2
2
2
2
2
2
2
1
2
2
2
2
2
2
2
2
HG
Environment
4
4
1
5
7
10
10
10
10
10
10
10
10
10
10
2
2
2
2
2
2
2
2
Nearest
Climate
Center
76
76
79
3
3
92
92
92
92
92
92
92
92
92
92
7
7
7
7
7
7
7
7
Site
Weighting
3.61
3.61
38.75
1.01
1.01
7.21
7.21
7.21
7.21
7.21
7.21
7.21
7.21
7.21
164.74
7.67
7.67
7.67
7.67
7.67
7.67
7.67
7.67
o
CO
00
-------
Table D.2 Nationwide Database of Surface Impoundment Sites
Site
Number
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
Area
(m2)
2.22E+04
2.33E+04
1.44E+03
1.86E+03
4.33E+03
7.28E+02
3.99E+04
4.69E+04
2.02E+02
1.52E+03
1.19E+03
7.41 E+03
1.81E+03
5.16E+04
7.00E+01
Operating
Depth
(m)
0.23
1.83
1.22
0.30
0.91
0.91
3.96
1.98
2.13
0.00
3.20
-999
-999
-999
0.06
Base Depth
Below Grade
(m)
0.99
2.13
1.83
0.61
2.59
2.74
4.27
2.90
1.83
0.00
4.27
0.00
0.00
0.06
0.76
Total
Thickness of
Sediment
(m)
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
Soil/GW
Temp.
CO
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
22.5
17.5
17.5
12.5
12.5
12.5
22.5
Distance to
Nearest SW
Body
(m)
810
1390
624
230
500
710
1080
960
5000
5000
5000
240
190
150
480
Operating
Life/Leaching
Duration
(yr)
50
50
50
50
50
50
50
50
27
12
50
50
50
50
6
Soil
Type
2
1
2
2
2
2
2
2
2
2
3
3
3
3
3
HG
Environment
2
2
2
2
2
2
2
2
4
4
1
6
6
6
10
Nearest
Climate
Center
7
7
7
7
7
7
7
7
94
34
77
6
6
6
96
Site
Weighting
7.67
7.67
7.67
7.67
7.67
7.67
7.67
7.67
26.72
25.16
20.95
216.36
216.36
216.36
7.02
o
CO
CO
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Area
(m2)
1.01E+02
3.78E+02
1.21E+02
1.21E+02
4.45E+02
8.09E+01
5.20E+03
8.09E+01
1.35E+03
3.24E+02
1.21E+03
6.07E+02
6.20E+05
1.21E+02
2.43E+02
6.75E+00
6.07E+02
4.05E+01
2.10E+03
3.64E+02
8.09E+01
4.05E+03
4.05E+01
4.86E+03
4.05E+01
1.21E+02
2.02E+01
2.02E+04
2.02E+01
5.58E+03
1.21E+02
1.62E+02
5.58E+03
2.02E+01
3.24E+04
2.02E+01
2.02E+01
1.21E+02
2.43E+02
2.02E+03
2.02E+01
2.43E+04
8.09E+01
1.01E+03
Depth
(m)
1.71E-01
1.60E+00
7.46E+00
2.10E-01
2.52E+01
2.23E-01
4.79E-02
7.27E+00
3.47E-01
1.40E+01
9.32E-02
3.73E-02
9.65E-07
2.62E+00
6.90E-01
1.34E+02
5.13E-02
1.68E+00
1.38E-01
1.49E-01
6.71 E-01
4.47E-02
2.24E-01
5.03E-01
2.22E-02
8.95E+00
3.69E+01
1.12E-03
1.34E+01
-9.99E+02
2.24E+01
2.01 E+01
1.05E-02
-9.99E+02
1.23E+00
2.24E+01
4.65E+00
2.24E+00
5.22E+00
8.95E-02
2.15E+00
8.76E-02
1.23E+00
3.56E-01
Soil/GW
Temperature
CC)
12.5
12.5
17.5
12.5
12.5
17.5
12.5
12.5
22.5
12.5
17.5
12.5
12.5
7.5
17.5
22.5
12.5
17.5
12.5
12.5
12.5
12.5
17.5
17.5
22.5
12.5
12.5
17.5
22.5
7.5
12.5
17.5
12.5
12.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
22.5
12.5
17.5
HG
Environment
2
12
4
12
12
1
2
5
4
12
12
12
12
2
13
4
2
4
12
8
12
4
5
12
4
4
2
4
4
2
9
5
12
5
4
12
4
2
2
2
2
4
2
4
Nearest
Climate
Center
39
69
90
54
53
79
52
74
58
85
89
42
69
32
90
92
53
95
32
82
42
66
1
93
91
56
71
79
81
32
51
12
71
26
74
51
79
66
53
71
66
92
88
80
Site
Weighting
10
10
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
20
20
20
20
20
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
D-40
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
Area
(m2)
4.05E+01
1.08E+02
4.05E+01
1.62E+02
1.21E+03
4.05E+01
8.09E+01
1.01E+03
2.02E+01
2.02E+01
2.02E+02
1.86E+04
8.09E+01
8.09E+01
2.63E+04
2.02E+01
4.05E+01
1.62E+02
2.02E+02
2.02E+01
4.05E+02
2.83E+02
6.88E+02
9.31 E+02
2.02E+01
2.02E+01
4.05E+01
2.79E+03
4.05E+01
2.43E+03
2.02E+01
1.00E+05
2.02E+01
8.99E+03
2.43E+02
4.05E+03
4.05E+02
1.08E+02
2.70E+01
2.02E+01
2.02E+02
8.63E+02
1.16E+04
4.05E+03
Depth
(m)
4.47E+00
1.01E+01
1.01E+00
2.10E+00
1.12E+00
3.13E+01
1.85E-02
1.79E+01
3.95E-02
1.10E+01
1.12E-01
9.75E-03
4.92E-01
3.95E-02
-9.99E+02
3.95E-02
3.80E-01
7.92E-01
1.86E-01
1.34E+02
3.35E-02
9.59E-01
2.63E+00
3.65E-01
1.32E+02
4.04E-01
5.37E+00
-9.99E+02
6.98E+01
7.46E-02
8.95E+00
1.36E-01
1.97E+01
1.79E+01
2.24E+01
3.36E-01
1.23E+00
3.75E+01
4.59E+01
1.23E+02
8.95E+00
5.77E+00
7.40E+00
2.24E-01
Soil/GW
Temperature
CC)
12.5
17.5
12.5
7.5
12.5
12.5
12.5
12.5
7.5
12.5
12.5
7.5
12.5
12.5
12.5
17.5
12.5
7.5
12.5
17.5
22.5
7.5
12.5
17.5
12.5
12.5
12.5
12.5
12.5
12.5
17.5
12.5
12.5
12.5
22.5
22.5
12.5
12.5
12.5
17.5
12.5
17.5
12.5
12.5
HG
Environment
12
1
4
2
9
8
4
2
5
2
2
4
9
5
4
4
2
2
12
12
4
12
4
2
12
2
12
4
4
2
13
5
12
9
4
4
4
6
2
4
12
12
12
5
Nearest
Climate
Center
42
95
66
32
42
42
74
59
3
71
88
60
51
29
52
80
71
48
85
89
58
32
39
58
85
74
50
51
51
52
34
26
42
42
81
91
71
74
66
95
42
85
49
69
Site
Weighting
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
1
1
1
1
1
1
1
1
1
1
1
1
1
D-41
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
Area
(m2)
7.45E+04
9.31 E+02
9.44E+01
4.05E+04
4.28E+03
2.02E+01
5.61 E+03
1.62E+02
1.21E+04
5.58E+03
2.02E+02
2.02E+03
2.02E+01
6.07E+05
1.11 E+03
1.34E+03
8.09E+01
2.10E+03
4.05E+01
4.05E+01
1.21 E+02
4.05E+01
8.09E+01
1.62E+02
1.01 E+02
4.05E+03
2.33E+02
9.44E+03
4.05E+03
2.02E+01
2.02E+02
5.67E+04
2.43E+02
4.05E+01
1.42E+02
5.67E+04
1.62E+02
1.89E+02
2.02E+01
2.16E+04
6.48E+02
2.02E+01
2.02E+03
1.21E+04
Depth
(m)
3.65E-01
1.46E-01
5.59E+00
1.79E-02
1.16E+00
8.95E+00
2.53E+00
3.50E+01
5.97E+00
1.22E-01
2.91 E+00
1.40E-01
5.38E-01
1.19E+00
4.88E-02
1.48E-01
5.60E-01
7.74E-01
7.05E+00
2.24E+02
9.69E+01
1.73E-02
1.17E+01
8.18E+00
1.61E+01
1.12E-02
4.86E+00
2.08E+00
8.05E-02
1.34E+02
5.37E+01
8.63E-04
3.54E+01
3.27E+02
-9.99E+02
1.64E-02
1.29E+00
4.15E+01
1.68E+02
2.80E+00
1.96E+00
1.66E+01
5.22E+00
8.95E-01
Soil/GW
Temperature
CC)
12.5
12.5
17.5
17.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
7.5
17.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
17.5
12.5
7.5
12.5
12.5
17.5
12.5
17.5
12.5
7.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
12.5
17.5
12.5
HG
Environment
4
4
12
1
12
12
4
4
12
2
2
13
2
2
2
4
8
2
12
2
12
1
2
2
1
4
4
12
12
8
2
4
9
4
12
5
12
4
12
2
12
2
12
13
Nearest
Climate
Center
52
66
95
95
88
52
81
72
49
66
66
66
36
69
52
96
32
74
42
69
95
71
50
39
75
93
74
95
71
32
66
52
51
72
42
3
42
51
48
32
71
74
89
82
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D-42
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
Area
(m2)
8.09E+01
1.56E+02
2.10E+03
4.05E+04
4.05E+01
6.27E+03
1.21E+04
4.05E+01
2.43E+02
6.48E+02
1.01E+04
2.02E+01
4.05E+03
1.86E+03
3.97E+03
1.21E+02
4.45E+02
1.52E+03
7.45E+03
8.09E+03
3.91 E+02
4.05E+01
1.42E+03
8.09E+01
1.25E+03
6.07E+01
9.20E+02
3.64E+02
9.31 E+02
9.31 E+02
8.09E+01
6.88E+02
8.09E+02
1.51E+04
5.22E+03
4.05E+03
4.05E+03
4.05E+03
2.02E+02
2.70E+03
5.58E+03
4.45E+02
9.75E+03
1.01E+03
3.24E+02
Depth
(m)
-9.99E+02
2.67E+01
1.08E-01
5.59E-02
5.59E+00
7.16E-04
-9.99E+02
1.68E-01
3.36E+02
-9.99E+02
4.75E-01
6.44E+01
8.05E-02
8.75E-01
5.24E-02
-9.99E+02
6.10E+00
7.27E-01
1.80E+00
5.59E-01
1.93E+00
-9.99E+02
4.79E+00
1.39E-01
1.67E+00
9.32E+00
1.18E+02
4.97E-01
2.43E-01
1.95E+00
3.99E+00
3.29E-01
9.02E-01
5.71 E-01
3.69E-02
4.03E+00
2.07E-01
1.12E-02
2.24E-01
2.51 E-01
7.29E-02
5.08E-01
1.58E+00
1.23E-05
8.11E-02
Soil/GW
Temperature
CC)
12.5
12.5
7.5
12.5
12.5
22.5
12.5
12.5
12.5
12.5
12.5
7.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
7.5
12.5
12.5
12.5
7.5
17.5
12.5
12.5
12.5
12.5
12.5
7.5
7.5
7.5
7.5
12.5
17.5
22.5
17.5
7.5
12.5
17.5
17.5
12.5
17.5
HG
Environment
12
12
4
9
6
4
2
13
2
2
2
4
12
2
2
4
2
9
4
2
13
1
2
9
2
12
9
12
12
2
12
12
13
4
8
2
4
12
13
12
5
5
2
8
5
Nearest
Climate
Center
42
42
47
42
73
81
66
71
52
66
52
84
71
39
52
27
52
42
72
39
45
75
71
42
32
89
42
51
51
39
69
45
4
60
32
74
95
57
90
48
40
12
37
9
34
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D-43
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
Area
(m2)
6.07E+03
4.05E+01
4.05E+01
2.02E+03
2.02E+03
1.47E+06
1.82E+03
9.31 E+02
1.01E+05
2.02E+04
1.42E+06
6.07E+02
1.15E+06
2.02E+01
3.04E+05
4.05E+03
2.83E+02
2.02E+01
4.45E+02
8.09E+04
2.02E+03
2.02E+02
2.02E+01
2.79E+03
8.09E+01
1.01E+01
9.96E+03
4.05E+01
8.09E+01
2.09E+04
2.02E+01
2.02E+01
9.31 E+02
8.50E+02
3.64E+02
1.05E+03
3.04E+03
9.31 E+02
8.09E+01
2.02E+01
1.94E+03
1.01E+01
1.39E+04
1.01E+01
Depth
(m)
2.98E-02
1.33E-01
5.60E-01
6.71 E-02
1.57E-01
4.88E-01
4.65E-02
1.23E-01
8.95E-02
2.06E+00
1.92E+00
1.12E+01
4.29E-01
1.45E+00
5.22E-01
2.24E-03
1.59E-02
5.28E+00
4.06E-02
2.24E-02
4.47E-01
4.47E-01
4.93E-03
6.43E-04
8.38E-02
9.86E-03
4.55E-01
6.73E-01
2.71 E-02
1.64E+00
4.14E+00
1.13E-01
7.50E-04
5.87E-05
3.35E+00
2.31 E-03
3.06E-01
2.34E-02
1.73E-02
1.23E-01
1.03E+00
-9.99E+02
2.87E-05
2.71 E-01
Soil/GW
Temperature
CC)
12.5
22.5
22.5
7.5
22.5
22.5
17.5
17.5
22.5
12.5
22.5
22.5
22.5
12.5
22.5
17.5
17.5
12.5
17.5
12.5
17.5
17.5
17.5
12.5
17.5
22.5
12.5
17.5
17.5
12.5
17.5
12.5
17.5
12.5
12.5
12.5
17.5
17.5
22.5
17.5
12.5
22.5
17.5
7.5
HG
Environment
12
12
4
13
5
12
13
13
4
1
12
4
4
13
12
4
2
12
4
4
2
12
4
8
1
4
5
12
4
2
4
13
4
5
1
4
4
12
12
5
12
12
5
5
Nearest
Climate
Center
50
76
92
5
92
57
29
29
92
71
57
92
92
71
57
30
77
51
90
48
36
79
90
55
95
81
33
90
69
39
90
19
90
56
67
71
69
89
78
12
73
78
13
3
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
22
22
3
3
3
3
3
3
3
3
3
1
1
1
1
1
1
1
1
1
1
1
D-44
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
Area
(m2)
3.04E+04
4.05E+02
2.02E+02
2.02E+01
2.48E+05
1.01E+04
8.09E+01
1.50E+04
4.05E+01
2.02E+03
1.50E+03
2.02E+04
4.05E+03
4.05E+01
2.02E+01
2.02E+03
8.09E+03
1.62E+02
4.05E+01
1.86E+03
1.35E+01
1.13E+03
2.02E+01
1.01E+06
8.09E+01
4.05E+01
5.40E+03
3.72E+03
1.13E+03
6.75E+02
6.88E+02
9.29E+03
6.07E+01
4.05E+03
1.62E+04
4.05E+01
9.31 E+02
1.62E+04
1.21 E+02
1.21 E+02
2.02E+01
2.02E+03
4.45E+02
4.86E+03
Depth
(m)
1.41E+01
1.84E-01
6.71 E+00
2.47E-01
-9.99E+02
-9.99E+02
1.40E+01
5.76E-01
1.12E+01
2.01 E-01
2.66E-01
2.17E+00
4.19E+00
8.29E-01
1.13E-01
2.24E-02
1.12E-03
4.05E+01
2.35E+01
3.04E-02
1.11 E-01
4.99E+00
2.96E-01
1.34E+00
1.58E+00
6.76E-01
4.19E-02
1.22E-02
7.93E-04
6.04E-02
8.55E-01
2.26E-02
1.49E-01
1.79E+00
1.68E+01
2.71 E-02
2.92E+00
5.59E-02
3.58E-01
2.24E+00
1.78E-01
4.47E-02
5.08E+00
4.66E-02
Soil/GW
Temperature
CC)
12.5
12.5
12.5
17.5
22.5
17.5
12.5
12.5
17.5
7.5
7.5
12.5
12.5
17.5
17.5
17.5
22.5
12.5
12.5
12.5
12.5
12.5
12.5
22.5
12.5
22.5
12.5
12.5
17.5
12.5
12.5
12.5
12.5
12.5
17.5
12.5
17.5
17.5
22.5
22.5
17.5
12.5
22.5
12.5
HG
Environment
5
9
12
5
4
1
12
2
5
5
1
4
12
13
13
4
4
5
4
4
12
12
2
12
1
4
5
2
1
4
2
12
5
2
4
8
5
4
4
12
13
12
5
13
Nearest
Climate
Center
69
42
42
12
96
69
42
39
21
10
64
56
19
13
77
95
58
74
72
73
51
50
88
57
65
92
40
54
79
51
51
54
56
33
74
46
12
79
81
57
90
55
92
20
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
8
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
D-45
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
Area
(m2)
3.62E+04
1.00E+04
1.52E+03
1.94E+06
1.30E+06
2.91 E+05
4.65E+04
4.05E+03
2.63E+02
2.99E+04
1.21E+04
1.21E+02
7.64E+04
4.05E+03
4.25E+05
4.46E+04
9.31 E+02
8.09E+03
4.99E+05
1.89E+05
1.42E+02
2.06E+03
5.03E+04
2.02E+03
4.05E+01
4.45E+04
1.30E+03
4.05E+01
2.02E+01
4.05E+01
4.05E+02
2.02E+01
2.02E+01
4.05E+03
2.02E+03
6.75E+00
2.02E+01
2.43E+02
1.21E+03
6.88E+02
4.17E+03
2.02E+01
1.62E+02
2.02E+01
Depth
(m)
1.90E+00
2.84E-02
5.67E-01
6.52E-01
1.82E+01
1.55E+00
5.44E-02
4.47E-02
1.55E-01
1.36E+00
8.96E-04
4.59E+00
3.26E-01
2.24E-02
2.66E+00
1.52E-02
1.22E-01
9.86E-05
3.45E+00
9.59E-01
8.10E-03
2.19E-01
1.08E-01
1.01E-01
3.08E+00
9.97E-01
1.75E-01
3.92E+00
-9.99E+02
-9.99E+02
4.44E-03
4.47E+00
5.03E-01
5.60E-03
6.71 E-02
1.18E-01
8.88E-02
6.99E-03
1.89E-03
-9.99E+02
8.69E+00
4.49E-01
1.05E-01
1.78E-01
Soil/GW
Temperature
CC)
17.5
17.5
12.5
22.5
22.5
22.5
22.5
7.5
12.5
17.5
17.5
22.5
22.5
12.5
17.5
12.5
22.5
22.5
22.5
7.5
17.5
12.5
17.5
22.5
12.5
17.5
22.5
22.5
12.5
22.5
12.5
17.5
7.5
12.5
22.5
22.5
22.5
7.5
17.5
22.5
7.5
17.5
7.5
17.5
HG
Environment
1
5
4
4
12
12
4
8
2
12
12
4
4
13
2
1
4
4
12
13
4
13
5
4
4
1
12
4
9
4
2
5
4
12
4
13
12
2
12
4
8
13
2
4
Nearest
Climate
Center
89
74
74
20
57
57
92
32
66
89
87
81
20
72
80
71
92
35
78
5
74
86
13
96
74
95
93
35
42
81
71
12
75
54
92
92
57
48
95
92
32
37
32
90
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
D-46
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
Area
(m2)
8.09E+01
5.67E+02
4.05E+01
2.02E+01
3.72E+03
4.05E+03
1.21E+02
8.09E+01
1.21E+04
4.45E+02
7.01 E+02
2.02E+03
4.05E+02
2.02E+01
2.02E+01
1.01E+04
4.05E+01
2.02E+01
2.02E+01
2.02E+01
8.09E+01
4.05E+01
2.02E+01
2.02E+01
2.02E+03
8.09E+01
2.02E+01
2.02E+02
4.05E+01
4.65E+02
4.05E+02
2.02E+01
1.01E+03
4.05E+01
4.05E+02
4.05E+03
3.72E+03
2.02E+03
4.45E+02
2.02E+02
2.02E+03
2.02E+01
4.05E+03
2.14E+05
6.88E+02
Depth
(m)
5.59E+00
1.60E-01
3.36E+00
8.93E-01
2.43E+00
8.88E-04
8.39E-01
1.01 E+02
7.46E-01
6.10E-01
8.60E-02
1.68E-03
8.88E-03
1.97E-02
1.79E+01
2.24E-03
3.92E-01
3.58E+00
2.24E+00
6.90E-02
1.68E-01
3.92E+00
9.37E-02
3.16E-01
5.57E-03
1.01E-01
8.93E-01
2.80E-01
2.33E+01
8.75E-01
6.71 E-02
-9.99E+02
3.31 E-02
2.79E-01
4.19E-02
1.12E-02
1.52E-02
5.37E-02
6.59E-02
4.44E-03
7.74E-01
2.91 E+00
8.39E+00
9.96E-01
6.58E+00
Soil/GW
Temperature
CC)
12.5
17.5
12.5
7.5
12.5
7.5
12.5
22.5
17.5
17.5
17.5
12.5
17.5
17.5
12.5
22.5
12.5
17.5
7.5
12.5
12.5
7.5
12.5
12.5
22.5
17.5
17.5
22.5
12.5
17.5
17.5
12.5
17.5
12.5
7.5
17.5
12.5
12.5
17.5
17.5
22.5
7.5
17.5
17.5
12.5
HG
Environment
13
2
12
2
12
2
8
4
2
1
4
1
12
5
5
12
5
4
12
9
8
13
4
2
4
12
4
12
12
2
5
2
12
4
1
4
2
1
12
4
4
5
4
8
12
Nearest
Climate
Center
74
36
42
43
85
31
46
14
58
69
90
71
79
12
69
57
19
90
48
42
46
49
74
53
92
95
77
91
42
36
13
71
89
66
44
90
31
71
95
36
92
3
79
74
32
Site
Weighting
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
D-47
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
Area
(m2)
2.02E+01
2.02E+01
4.05E+03
3.52E+04
9.31 E+02
4.05E+01
6.07E+03
3.44E+03
4.45E+02
6.75E+02
8.09E+01
6.07E+03
2.43E+02
2.43E+02
1.21E+03
8.09E+03
6.07E+03
2.79E+03
1.35E+01
9.31 E+02
2.02E+01
3.56E+03
1.62E+04
8.09E+03
1.21 E+02
1.21E+04
9.31 E+02
2.02E+01
3.64E+02
5.67E+02
8.09E+03
4.05E+01
1.01E+01
1.01E+01
4.45E+02
8.09E+01
2.02E+01
1.42E+02
8.09E+01
8.09E+03
6.07E+03
8.09E+01
2.02E+03
4.05E+01
Depth
(m)
4.47E+00
8.88E-02
2.24E-02
2.35E-01
1.82E-02
1.23E+01
-9.99E+02
4.95E-01
7.63E-01
2.49E-02
1.12E+01
7.46E-03
2.79E-02
1.49E-01
2.24E-01
4.14E-02
2.98E-01
8.11E-03
2.80E+01
8.75E+00
4.44E-02
6.36E-02
4.19E-03
6.16E-06
1.49E+00
2.24E+00
4.87E-02
2.80E+00
1.99E-01
2.00E-01
3.36E-01
2.68E+01
4.44E-02
1.17E+01
5.08E+00
6.71 E-01
1.33E-01
1.60E+01
1.12E-01
5.59E-01
1.12E+01
-9.99E+02
1.40E-02
3.35E-01
Soil/GW
Temperature
CC)
7.5
17.5
22.5
12.5
22.5
22.5
12.5
12.5
22.5
22.5
12.5
17.5
22.5
22.5
12.5
17.5
12.5
7.5
12.5
12.5
12.5
17.5
17.5
17.5
12.5
7.5
12.5
17.5
7.5
22.5
17.5
17.5
17.5
22.5
7.5
22.5
12.5
22.5
7.5
12.5
12.5
7.5
17.5
12.5
HG
Environment
12
1
12
4
12
12
12
13
12
12
12
5
11
4
8
13
4
4
5
12
1
4
1
5
2
4
4
2
2
4
1
4
5
4
1
4
2
12
4
8
4
2
1
5
Nearest
Climate
Center
48
79
91
84
93
97
72
32
91
97
87
14
57
96
54
20
66
31
26
42
8
92
77
12
59
25
13
36
32
35
69
90
13
92
65
81
71
78
6
82
51
45
79
26
Site
Weighting
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
D-48
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
Area
(m2)
1.21E+03
4.65E+03
1.01E+03
6.07E+02
6.07E+02
1.21E+02
1.21E+03
4.05E+01
2.83E+02
1.38E+03
2.83E+03
6.88E+02
8.09E+01
4.05E+01
8.09E+03
4.05E+01
4.05E+01
8.50E+02
4.05E+01
2.47E+03
1.42E+02
8.90E+03
2.02E+02
4.05E+01
1.62E+02
5.40E+01
2.27E+04
8.09E+01
4.05E+01
2.63E+02
4.05E+01
1.21E+04
2.02E+02
1.21E+03
4.86E+02
3.64E+02
4.05E+01
1.01E+04
2.23E+04
8.09E+01
2.02E+02
1.62E+04
4.65E+02
2.02E+03
Depth
(m)
3.70E-03
1.94E-02
2.24E-02
1.86E+00
9.32E-01
1.40E-01
1.49E-02
2.24E-01
-9.99E+02
1.97E+00
3.20E+00
1.32E-01
1.68E-01
5.37E+00
3.49E-03
3.35E-01
3.22E+00
9.86E-02
1.79E+01
1.28E-01
1.46E+02
2.24E-05
2.46E+00
2.24E+00
5.59E+01
1.40E+01
5.99E-01
1.39E-01
3.58E+00
9.06E-01
1.23E+01
1.87E-03
1.79E+00
5.44E+00
3.54E+00
4.97E-01
1.04E+02
1.21E+00
7.32E-01
7.94E-01
1.68E+01
4.19E-01
1.70E+00
2.68E-01
Soil/GW
Temperature
CC)
12.5
12.5
22.5
12.5
7.5
17.5
17.5
17.5
12.5
17.5
22.5
17.5
12.5
22.5
17.5
12.5
17.5
12.5
17.5
12.5
12.5
17.5
12.5
12.5
12.5
22.5
7.5
22.5
7.5
17.5
17.5
12.5
12.5
12.5
17.5
12.5
12.5
17.5
12.5
12.5
12.5
22.5
17.5
12.5
HG
Environment
9
4
12
4
4
5
2
5
4
12
2
5
4
5
4
8
13
6
5
12
2
8
8
4
9
4
8
4
12
5
5
4
2
12
1
1
4
2
4
9
12
12
5
12
Nearest
Climate
Center
42
19
76
65
10
53
74
1
72
95
58
12
51
14
69
46
34
51
12
74
71
74
63
72
42
58
32
81
45
34
1
65
74
49
77
61
51
74
39
51
49
78
12
71
Site
Weighting
9
9
9
9
9
9
9
9
9
9
1
9
9
9
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D-49
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
Area
(m2)
1.38E+03
1.27E+03
8.09E+01
4.05E+01
6.07E+01
4.05E+04
1.13E+03
1.21E+04
1.50E+03
3.34E+04
8.09E+01
2.23E+02
8.09E+01
6.75E+01
2.02E+01
4.05E+01
8.50E+02
2.06E+03
4.05E+01
2.02E+01
4.05E+01
3.64E+02
1.21E+03
4.45E+02
3.64E+02
2.02E+02
5.26E+03
2.02E+05
2.02E+01
2.43E+02
1.11E+04
2.02E+01
7.69E+04
8.09E+03
3.24E+04
2.02E+01
7.28E+04
4.05E+03
4.45E+02
2.02E+04
2.02E+01
1.38E+03
1.21E+02
2.02E+01
Depth
(m)
2.21 E-01
1.67E+00
2.80E-01
2.80E+01
4.00E+01
1.12E-02
7.19E-02
1.64E+00
1.81E+00
4.26E-02
1.01E+00
3.76E-01
2.80E+00
-9.99E+02
2.24E+01
1.70E+01
7.99E-01
8.77E+00
8.50E+00
1.79E+00
1.37E+01
3.84E-03
5.59E+00
1.42E+00
1.37E-04
2.01 E+00
5.68E-01
1.12E-01
3.28E+00
2.79E-01
1.61E-04
8.95E+00
2.05E-01
7.27E-01
2.32E+00
-9.99E+02
8.08E-01
1.80E-01
1.14E+01
7.40E-05
2.24E-01
6.58E+00
-9.99E+02
8.95E+00
Soil/GW
Temperature
CC)
12.5
17.5
22.5
17.5
17.5
22.5
12.5
22.5
12.5
17.5
12.5
12.5
22.5
7.5
12.5
7.5
22.5
12.5
12.5
12.5
17.5
12.5
22.5
12.5
12.5
17.5
12.5
12.5
7.5
7.5
17.5
12.5
12.5
12.5
12.5
12.5
12.5
17.5
17.5
17.5
22.5
12.5
22.5
17.5
HG
Environment
2
1
12
5
5
5
2
12
12
4
4
12
12
2
2
2
4
12
4
5
1
12
12
2
2
5
12
1
2
8
13
2
12
5
5
4
12
12
5
1
4
4
4
2
Nearest
Climate
Center
69
69
78
13
13
12
74
97
42
79
45
85
97
66
39
48
91
49
51
74
69
87
78
39
45
34
69
71
32
32
34
56
49
56
33
66
74
89
12
89
81
66
35
58
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D-50
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
Area
(m2)
1.86E+03
1.01E+01
4.05E+04
4.05E+03
2.02E+03
1.21E+02
1.35E+05
4.05E+01
1.13E+03
4.05E+01
1.62E+04
2.02E+03
4.05E+01
2.51 E+05
4.45E+02
1.42E+04
1.21E+04
4.05E+03
2.83E+02
1.94E+04
4.05E+03
1.62E+02
2.02E+01
4.05E+01
2.02E+01
2.02E+01
4.05E+03
3.24E+02
7.28E+02
1.38E+03
4.05E+03
6.07E+03
6.88E+02
1.62E+04
6.27E+03
2.91 E+03
1.25E+05
1.01E+04
6.58E+03
4.65E+03
3.08E+03
1.62E+04
2.43E+04
2.83E+02
4.45E+02
Depth
(m)
2.43E-01
1.79E+00
4.47E-01
2.24E-01
8.38E-04
1.86E+03
1.45E+00
2.33E+01
6.23E+00
6.99E+00
5.59E-01
2.91 E+00
5.18E+00
1.49E-01
2.44E+01
5.11E-01
2.98E-01
4.44E-04
8.53E-01
1.40E-01
2.80E+00
8.42E+00
1.78E-01
3.22E+01
3.95E-02
8.95E+01
1.96E+00
2.80E-02
9.32E-01
5.26E-01
3.69E-01
1.88E+01
3.29E-01
3.02E-01
3.61 E+00
3.26E+00
3.19E-02
1.23E-01
9.11E-02
2.98E-02
2.21 E+01
-9.99E+02
7.46E-01
1.28E-01
1.53E+00
Soil/GW
Temperature
CC)
17.5
12.5
12.5
12.5
22.5
22.5
17.5
17.5
17.5
17.5
12.5
12.5
17.5
12.5
17.5
12.5
12.5
17.5
12.5
12.5
7.5
17.5
12.5
7.5
12.5
17.5
12.5
12.5
17.5
7.5
17.5
12.5
7.5
22.5
12.5
12.5
22.5
17.5
7.5
17.5
22.5
7.5
7.5
12.5
17.5
HG
Environment
4
4
2
4
13
5
4
5
5
2
4
4
1
13
5
2
2
4
2
5
4
1
2
2
4
5
13
4
1
1
4
2
4
4
12
8
12
12
4
4
4
1
2
2
5
Nearest
Climate
Center
90
71
66
39
36
12
90
12
12
36
39
72
95
56
34
86
66
90
66
29
31
95
86
48
66
12
40
52
98
64
93
2
31
81
69
42
91
93
31
90
92
62
32
56
53
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
29
29
29
7
7
7
1
7
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D-51
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
Area
(m2)
9.11E+03
8.73E+04
2.19E+03
2.27E+03
4.52E+04
1.42E+02
6.21 E+02
5.06E+02
4.11 E+02
1.01E+05
4.86E+02
4.05E+01
2.37E+04
6.75E+04
9.31 E+02
6.07E+04
4.05E+03
4.05E+04
1.86E+03
7.28E+02
1.62E+04
5.58E+03
1.89E+02
2.02E+03
8.09E+01
2.02E+01
2.02E+02
2.02E+01
2.02E+01
2.83E+02
4.05E+01
2.06E+03
4.45E+02
9.31 E+02
2.02E+01
4.05E+01
2.02E+01
2.35E+04
2.02E+01
2.39E+04
1.21E+03
1.29E+06
1.52E+03
2.02E+01
Depth
(m)
2.14E-01
1.80E-03
1.92E-03
1.20E+00
1.84E-07
1.33E+01
9.73E-01
5.49E+01
4.77E+00
3.36E-02
1.67E+02
3.36E+01
6.69E-01
1.79E-01
1.34E+00
3.73E-01
5.03E-02
7.94E-02
2.58E+00
9.32E-01
1.75E-01
1.35E+00
2.40E+01
4.70E-01
5.55E-02
1.12E+00
6.21 E-02
2.47E-03
3.95E-02
1.60E-01
9.86E-03
2.19E+00
2.03E+00
3.65E-01
4.93E-02
8.38E-02
1.13E-01
3.57E-02
6.71 E+00
5.00E-01
2.24E+01
1.94E-08
2.98E+00
3.60E-01
Soil/GW
Temperature
CC)
22.5
12.5
7.5
17.5
7.5
12.5
7.5
12.5
7.5
17.5
7.5
12.5
7.5
22.5
12.5
22.5
17.5
12.5
12.5
17.5
17.5
12.5
7.5
22.5
12.5
17.5
17.5
12.5
7.5
7.5
22.5
22.5
17.5
17.5
7.5
7.5
12.5
17.5
12.5
17.5
17.5
22.5
12.5
12.5
HG
Environment
4
2
2
4
1
2
2
2
1
4
2
4
1
4
8
12
5
5
8
1
4
5
13
4
5
5
1
4
8
2
4
4
12
12
8
5
2
5
12
13
12
2
2
5
Nearest
Climate
Center
92
45
48
69
64
45
48
66
62
69
48
66
44
92
46
91
90
40
82
98
90
40
48
96
33
12
79
72
49
32
81
92
95
95
32
3
66
12
42
56
89
21
40
40
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
30
30
30
30
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
D-52
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
Area
(m2)
4.17E+03
8.09E+01
2.02E+01
4.25E+02
1.01E+01
2.02E+01
9.31 E+02
8.09E+02
1.01E+03
2.23E+02
7.28E+02
1.38E+03
2.31 E+03
2.02E+06
1.38E+03
7.61 E+03
2.02E+03
7.28E+02
1.74E+03
3.44E+03
8.09E+04
2.57E+04
8.90E+02
8.94E+03
8.38E+03
3.43E+04
2.43E+02
4.86E+03
1.01 E+03
2.31 E+03
4.05E+03
5.26E+02
2.02E+03
3.56E+05
4.05E+03
5.06E+00
8.50E+02
4.45E+02
2.02E+01
9.31 E+02
2.02E+01
2.02E+03
4.65E+02
2.02E+01
Depth
(m)
3.91 E-01
2.12E+00
2.96E-02
3.85E-01
2.24E+00
5.37E+01
1.17E+01
2.52E-01
3.13E+00
2.03E+00
3.11E-02
3.29E-01
2.75E+00
1.57E+00
1.32E-01
6.82E-01
5.03E-02
6.21 E-01
1.95E-01
1.32E-01
2.01 E-02
5.53E+00
2.85E+00
3.54E-01
1.08E-02
4.30E+00
5.51 E-02
2.80E-01
1.97E-01
3.92E+00
1.23E-05
3.66E-01
4.47E-01
1.53E-01
5.59E-02
3.35E-01
5.93E+00
9.41 E-03
1.33E-01
2.92E-02
2.22E-01
2.24E-01
3.60E-01
2.71 E-02
Soil/GW
Temperature
CC)
22.5
7.5
12.5
17.5
12.5
17.5
12.5
17.5
12.5
12.5
17.5
12.5
17.5
22.5
7.5
12.5
12.5
12.5
17.5
12.5
12.5
22.5
17.5
12.5
17.5
17.5
7.5
12.5
12.5
12.5
12.5
17.5
12.5
17.5
17.5
12.5
12.5
12.5
12.5
17.5
12.5
7.5
17.5
12.5
HG
Environment
13
2
2
13
8
5
4
1
1
12
12
5
12
5
1
5
13
4
5
8
5
2
2
1
4
4
2
12
2
8
5
4
13
13
4
12
8
12
2
5
2
4
13
8
Nearest
Climate
Center
30
45
86
90
42
12
74
69
31
45
95
40
93
22
65
69
40
45
90
9
26
22
74
31
93
22
45
72
71
9
40
90
20
90
23
42
46
48
66
53
88
83
53
53
Site
Weighting
4
4
4
4
4
4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
30
30
30
30
30
D-53
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
Area
(m2)
2.02E+01
6.75E+00
2.43E+02
3.04E+03
4.05E+01
2.02E+01
6.88E+02
2.02E+01
1.01E+05
5.26E+03
6.07E+03
2.02E+01
9.31 E+02
4.86E+04
5.67E+02
2.02E+01
3.72E+03
4.05E+01
4.45E+02
1.21E+04
1.86E+03
1.62E+03
3.64E+02
2.59E+04
3.24E+03
8.09E+03
1.21 E+02
4.05E+03
2.02E+01
5.67E+02
2.43E+02
4.05E+02
8.09E+01
2.02E+01
2.02E+01
1.13E+03
4.45E+02
1.82E+03
1.01E+01
3.36E+03
2.02E+01
1.38E+03
3.24E+03
2.02E+03
Depth
(m)
4.14E-01
1.48E-01
7.40E-03
1.12E+00
3.45E-02
4.47E+01
2.20E-01
2.24E+00
8.95E-04
3.10E-01
1.86E-03
1.97E-02
1.95E+00
9.32E-02
8.81 E-05
2.15E+01
6.08E-03
3.36E+01
4.98E+00
2.44E-01
7.29E+00
2.77E-03
6.82E-02
3.32E-01
2.21 E+00
1.68E-03
1.68E+00
5.59E-02
1.12E+00
1.48E-01
2.34E-02
6.66E-03
3.32E-01
2.47E-02
5.59E+00
3.99E-01
-9.99E+02
5.74E-01
4.44E-02
3.37E-02
4.44E-02
2.96E-01
3.48E-03
3.58E-01
Soil/GW
Temperature
CC)
12.5
22.5
17.5
12.5
7.5
22.5
17.5
12.5
7.5
22.5
17.5
7.5
12.5
22.5
12.5
17.5
17.5
7.5
17.5
7.5
12.5
17.5
12.5
22.5
12.5
22.5
12.5
12.5
12.5
12.5
7.5
22.5
17.5
12.5
12.5
17.5
17.5
12.5
22.5
12.5
7.5
12.5
12.5
12.5
HG
Environment
12
4
5
12
12
4
4
5
5
5
2
12
13
11
2
4
12
12
4
12
12
1
9
13
12
12
12
2
8
2
5
4
5
1
4
13
5
1
4
1
13
2
2
2
Nearest
Climate
Center
72
96
53
49
48
96
30
40
10
92
90
48
74
94
88
77
95
48
90
48
42
79
51
92
48
76
69
86
46
53
3
96
13
71
88
20
12
69
96
83
68
74
85
83
Site
Weighting
30
30
11
11
11
11
11
11
11
11
11
11
1
1
1
1
1
1
1
1
1
1
1
1
1
1
24
2
2
2
2
2
1
1
1
1
1
1
1
1
24
24
24
1
D-54
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
Area
(m2)
6.48E+02
4.09E+03
4.05E+04
2.23E+02
2.43E+02
2.43E+02
6.07E+03
4.05E+01
2.02E+02
1.82E+02
2.02E+03
5.67E+02
4.05E+03
4.05E+01
1.21E+02
7.43E+03
2.02E+01
1.62E+02
7.28E+02
1.38E+03
2.53E+02
1.62E+04
2.09E+04
4.05E+01
2.83E+02
3.04E+03
1.54E+04
4.05E+02
4.05E+03
5.40E+02
1.01E+04
9.31 E+02
9.31 E+02
1.42E+02
1.42E+02
4.45E+02
3.72E+03
1.38E+03
8.09E+04
1.38E+03
6.07E+02
8.09E+01
4.05E+01
4.05E+01
4.05E+03
Depth
(m)
1.47E-01
1.66E-01
4.47E-01
1.52E-01
1.19E-02
3.73E+00
2.42E-02
2.68E+01
8.88E-03
7.46E+00
1.13E-03
3.20E+00
1.80E-01
3.23E+00
6.71 E-01
1.68E-02
8.38E-02
1.68E-01
1.55E-01
3.26E-03
3.91 E-01
3.50E-02
3.03E-02
5.18E-02
2.51 E+00
7.40E-04
4.12E-02
1.12E+00
7.22E-01
1.12E+00
1.58E-04
9.73E-01
2.07E-01
9.59E-01
1.60E-01
1.02E+00
1.02E-01
1.69E-02
3.36E-03
4.13E-03
4.44E-03
6.71 E-01
1.23E-03
2.07E-01
7.84E-03
Soil/GW
Temperature
CC)
12.5
17.5
12.5
17.5
12.5
17.5
12.5
12.5
17.5
22.5
22.5
17.5
12.5
12.5
22.5
7.5
17.5
7.5
12.5
22.5
12.5
12.5
12.5
17.5
17.5
17.5
7.5
12.5
22.5
12.5
17.5
12.5
12.5
12.5
17.5
17.5
7.5
17.5
17.5
12.5
12.5
12.5
17.5
12.5
22.5
HG
Environment
9
5
4
1
5
4
12
4
5
4
12
5
5
2
12
4
5
4
12
4
8
2
12
12
13
4
2
4
4
2
13
5
5
2
4
13
4
4
4
2
5
5
13
5
4
Nearest
Climate
Center
42
12
66
95
26
80
74
72
100
96
92
37
4
66
76
25
12
68
54
81
82
45
54
95
13
23
7
72
81
66
90
26
26
66
95
81
31
95
92
45
4
74
37
26
96
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D-55
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
Area
(m2)
2.02E+04
4.05E+01
9.31 E+02
2.02E+03
5.67E+02
4.45E+02
2.02E+01
2.02E+03
4.05E+01
4.05E+01
2.02E+03
6.75E+00
4.05E+03
2.02E+01
1.01E+01
4.05E+01
2.43E+02
2.02E+01
2.02E+01
2.02E+01
2.02E+01
2.83E+02
2.02E+02
8.09E+01
9.31 E+02
5.06E+01
8.50E+02
4.05E+01
2.02E+01
2.02E+01
2.02E+01
2.02E+01
1.21E+03
2.02E+01
4.05E+01
4.65E+02
2.02E+01
2.43E+02
1.66E+03
1.21E+03
8.09E+01
4.45E+02
4.45E+02
2.02E+01
Depth
(m)
4.47E-01
1.12E+00
9.73E-01
8.88E-04
6.39E+00
2.03E-01
2.46E+00
4.47E-02
2.24E-01
1.23E-02
8.95E-02
1.12E+00
4.47E-01
8.88E-02
1.97E-02
8.39E+01
-9.99E+02
9.86E-03
3.49E+01
5.59E+00
7.45E-01
6.38E-02
4.32E+01
3.50E+00
8.75E-01
2.22E-02
1.44E-01
5.59E+01
1.23E-01
1.33E-01
1.68E-01
3.95E-02
3.73E-02
-9.99E+02
1.68E+00
5.93E-01
9.86E-03
1.16E-01
6.82E-01
1.49E+00
5.60E-01
2.75E+00
1.64E-02
8.88E-02
Soil/GW
Temperature
CC)
12.5
12.5
17.5
12.5
22.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
7.5
7.5
17.5
12.5
12.5
17.5
12.5
7.5
17.5
12.5
17.5
12.5
12.5
12.5
12.5
22.5
22.5
17.5
17.5
17.5
7.5
12.5
12.5
12.5
17.5
12.5
17.5
7.5
17.5
12.5
12.5
22.5
HG
Environment
2
2
13
12
4
5
2
13
1
4
5
5
13
2
5
2
4
5
4
13
5
12
1
12
4
4
4
5
4
2
4
5
1
2
4
8
5
12
4
4
1
12
5
4
Nearest
Climate
Center
66
87
56
74
96
26
69
90
95
30
53
12
45
48
12
69
63
12
56
45
12
54
89
51
51
45
72
92
92
36
34
21
64
32
51
46
12
49
80
31
95
49
40
81
Site
Weighting
1
1
1
1
1
1
1
1
1
1
1
1
1
30
10
10
10
10
10
10
10
1
1
1
1
1
1
31
31
31
31
31
7
7
7
7
7
7
7
7
7
7
7
7
D-56
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
111
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
Area
(m2)
2.02E+01
2.02E+03
4.05E+01
6.48E+02
1.10E+02
1.21E+03
1.62E+02
1.62E+02
4.05E+01
4.05E+01
4.05E+03
8.09E+01
1.21E+02
2.83E+02
1.94E+04
2.02E+03
8.09E+02
2.43E+02
1.01E+02
8.09E+01
2.02E+01
1.82E+02
4.05E+01
2.08E+03
2.02E+01
8.09E+01
4.05E+01
6.75E+01
4.05E+01
2.02E+02
5.06E+00
4.05E+01
8.09E+01
9.31 E+02
4.05E+01
2.22E+04
8.09E+01
8.09E+01
9.31 E+02
4.05E+01
9.11E+04
2.02E+01
2.02E+01
6.88E+02
Depth
(m)
2.24E+00
1.16E+00
4.02E-01
4.89E+00
8.68E-01
2.49E-01
6.04E+01
1.51E+01
1.40E+02
1.40E+02
2.10E-01
6.71 E-01
4.25E+01
1.28E+01
7.50E+00
1.72E+01
1.34E+01
1.98E+00
4.47E+00
7.05E-01
2.22E-01
1.53E+01
5.67E-02
6.52E-01
8.88E-02
2.24E+00
2.91 E-01
4.47E+01
4.24E+00
2.58E-01
8.38E-02
2.80E+00
5.55E-02
3.16E-01
5.60E-01
4.49E-02
2.52E-01
1.99E+00
4.38E-01
2.46E+01
3.69E-01
3.95E-02
6.90E-01
5.53E-02
Soil/GW
Temperature
CC)
17.5
22.5
12.5
17.5
12.5
17.5
12.5
12.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
7.5
12.5
7.5
7.5
12.5
12.5
12.5
12.5
22.5
17.5
22.5
12.5
12.5
17.5
12.5
12.5
17.5
17.5
12.5
12.5
12.5
17.5
7.5
17.5
7.5
7.5
12.5
12.5
12.5
HG
Environment
5
12
12
5
4
1
2
12
12
12
6
9
2
1
2
2
8
2
12
2
1
8
4
4
4
4
12
5
4
5
4
1
4
12
1
9
2
13
5
13
2
12
12
2
Nearest
Climate
Center
14
93
42
12
74
95
52
49
49
49
73
51
45
64
52
32
63
32
48
59
53
42
51
81
90
92
49
40
34
74
72
77
95
52
71
63
36
68
13
32
32
42
42
71
Site
Weighting
7
7
7
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
22
2
2
D-57
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.3 Nationwide Database of Waste Pile Sites
Site
Numbe
r
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
Area
(m2)
2.02E+01
2.02E+01
1.21E+02
8.09E+01
4.05E+01
3.24E+02
5.95E+03
1.01E+01
1.40E+06
2.02E+01
4.05E+01
2.02E+03
2.83E+02
2.02E+01
2.83E+02
8.09E+01
8.09E+01
1.01E+04
2.83E+02
2.33E+03
8.09E+01
6.52E+03
1.49E+04
8.09E+01
4.05E+01
4.05E+03
2.02E+01
2.02E+01
4.05E+03
2.02E+03
2.29E+02
Depth
(m)
2.68E+01
3.36E+01
7.46E-01
7.64E-02
7.89E-02
3.50E+00
2.71 E-01
1.04E-01
8.41 E-06
4.44E-02
1.01 E-01
4.44E-04
3.20E+00
5.57E-01
8.00E-02
4.70E+01
6.29E-01
1.18E-01
2.21 E-01
1.94E-02
5.55E-03
2.92E-01
8.53E-04
3.08E-02
1.23E-02
-9.99E+02
2.91 E+00
2.22E-01
1.54E-01
1.12E+00
2.63E-01
Soil/GW
Temperature
CC)
17.5
12.5
12.5
12.5
17.5
12.5
22.5
7.5
7.5
12.5
12.5
17.5
17.5
17.5
12.5
17.5
17.5
12.5
17.5
17.5
12.5
12.5
12.5
17.5
17.5
7.5
7.5
22.5
12.5
7.5
12.5
HG
Environment
4
4
4
2
5
5
4
12
8
1
4
1
1
12
1
1
1
12
12
1
2
1
1
1
5
1
12
12
2
8
2
Nearest
Climate
Center
95
39
66
52
12
74
81
45
62
71
61
95
79
89
63
95
89
72
85
77
42
69
69
69
12
31
48
58
85
62
66
Site
Weighting
2
2
2
2
2
1
1
1
31
31
7
7
7
7
1
1
1
1
1
1
1
1
1
1
29
3
3
3
1
1
1
D-58
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.4 Nationwide Database of Land Application Unit Sites
Site
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Area
(m2^
4.05E+05
2.43E+04
4.45E+06
1.01E+04
4.05E+03
6.07E+04
4.86E+05
2.02E+04
4.05E+03
2.10E+05
1.01E+03
2.02E+03
6.48E+05
1.94E+06
1.05E+06
9.31 E+03
4.05E+03
8.09E+06
5.58E+03
4.05E+01
6.07E+03
6.07E+04
4.05E+05
1.01E+05
4.05E+05
1.21E+06
1.26E+06
3.24E+05
4.05E+03
5.10E+05
1.21E+05
4.05E+03
9.31 E+04
6.48E+03
1.21 E+04
1.09E+05
4.05E+01
8.09E+07
4.32E+04
1.27E+05
2.83E+04
1.90E+05
4.61 E+05
9.71 E+05
6.68E+06
Depth
frrrt
9.65E-01
5.75E-05
7.11E-01
2.82E-02
3.76E-02
1.71E+00
1.68E+00
9.31 E-02
1.86E+00
9.68E-03
1.87E-03
9.49E-02
4.07E-01
7.85E-01
7.09E-01
1.63E-02
4.46E-03
3.02E-04
5.29E-03
5.65E-01
3.10E-01
6.82E-01
3.58E-01
2.98E-01
1.12E+00
1.43E-01
2.47E-01
8.38E-02
4.46E-03
3.91 E-01
6.06E-01
5.59E-02
5.62E-01
4.40E-02
1.86E-02
2.84E-01
-9.99E+02
1.12E-05
-9.99E+02
9.68E-03
1.99E-03
6.98E-01
1.30E-04
2.43E-02
4.51 E-01
Soil/GW
Temperature
rn
12.5
12.5
12.5
12.5
7.5
7.5
12.5
7.5
7.5
7.5
7.5
12.5
12.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
17.5
22.5
17.5
17.5
17.5
17.5
7.5
7.5
7.5
12.5
12.5
17.5
17.5
17.5
17.5
HG
Environment
1
2
2
5
2
5
1
1
1
1
4
1
1
8
8
5
5
5
5
5
5
5
5
5
5
5
5
5
5
4
5
5
4
4
5
5
1
4
4
2
7
2
4
4
4
Nearest
Climate Center
2
2
2
2
3
3
5
7
7
7
7
8
8
9
9
13
13
13
13
13
13
13
13
13
13
13
13
13
15
20
20
21
23
23
23
23
25
25
25
29
29
30
30
30
30
Site
Weiahtina
1
30
1
1
1
24
1
10
1
11
1
30
11
1
1
1
1
30
30
30
11
11
11
1
1
1
1
1
30
1
1
11
1
1
1
1
20
16
1
1
1
1
1
1
1
D-59
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.4 Nationwide Database of Land Application Unit Sites
Site
Number
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
Area
(m2^
5.71 E+04
8.50E+04
1.62E+05
2.43E+04
1.17E+05
4.05E+05
3.74E+05
4.45E+04
2.43E+05
2.43E+05
3.24E+05
1.72E+05
1.90E+04
6.48E+05
8.46E+05
2.36E+05
3.24E+04
2.79E+04
1.42E+03
8.50E+02
2.10E+03
6.48E+05
1.13E+04
1.21E+05
4.05E+03
3.44E+05
4.05E+03
8.09E+03
1.78E+04
2.02E+01
4.45E+02
2.02E+05
2.23E+06
1.21 E+04
3.04E+05
5.91 E+04
1.70E+05
9.31 E+05
5.74E+04
2.02E+05
2.43E+05
4.17E+04
1.01 E+05
1.34E+05
9.31 E+02
Depth
frrrt
1.12E-02
1.59E+00
2.80E-03
2.47E-05
1.48E-03
1.11E-03
2.03E+00
4.07E-03
5.58E-01
3.10E-01
9.60E-01
8.41 E-05
3.17E-03
2.80E-03
3.34E-03
3.99E-03
5.03E-03
4.09E-02
2.08E-02
2.66E-01
2.37E-06
1.44E-01
8.81 E-08
6.20E-02
2.22E-04
6.51 E-04
2.91 E-03
2.33E-03
4.23E-03
5.42E-02
-9.99E+02
1.33E-05
3.72E-04
7.46E-01
4.53E-04
-9.99E+02
1.66E-02
3.11 E-03
1.15E+00
4.49E-05
3.25E-05
7.50E-02
6.26E-04
1.24E+00
1.63E-01
Soil/GW
Temperature
rn
7.5
7.5
7.5
7.5
7.5
12.5
12.5
7.5
7.5
7.5
7.5
7.5
12.5
12.5
17.5
17.5
22.5
22.5
22.5
22.5
17.5
12.5
7.5
7.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
HG
Environment
2
2
2
2
4
8
8
2
2
8
8
8
2
5
2
2
4
4
4
4
5
2
1
12
2
12
12
12
12
12
12
12
12
6
8
8
8
8
9
9
9
9
2
2
8
Nearest
Climate Center
31
31
31
31
31
31
31
32
32
32
32
32
33
33
34
34
35
35
35
35
37
39
40
41
42
42
42
42
42
42
42
42
42
42
42
42
42
42
42
42
42
42
45
45
46
Site
Weiahtina
1
30
30
30
30
1
1
9
1
11
1
1
1
1
1
1
1
1
1
1
3
2
1
11
1
1
1
1
1
30
1
1
2
1
29
1
30
1
1
1
24
2
11
1
1
D-60
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.4 Nationwide Database of Land Application Unit Sites
Site
Number
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
Area
(m2^
4.65E+05
4.45E+04
2.43E+04
2.02E+04
1.21E+04
3.84E+05
6.31 E+05
3.35E+05
1.74E+06
3.24E+06
3.71 E+04
4.86E+04
2.71 E+05
8.09E+03
9.11 E+05
9.71 E+04
5.67E+05
3.76E+05
5.91 E+04
2.68E+05
8.09E+05
9.11 E+05
1.82E+05
2.02E+06
7.57E+05
3.69E+05
2.79E+03
2.02E+01
2.02E+04
2.02E+04
8.78E+05
2.23E+04
7.59E+04
1.01E+06
2.02E+06
2.63E+04
3.72E+03
8.09E+04
1.01 E+05
4.05E+04
2.43E+06
1.01 E+05
2.02E+04
8.09E+05
1.09E+05
Depth
frrrt
6.31 E-01
4.33E-03
5.97E-02
6.71 E-01
7.44E-01
1.47E-01
6.92E-02
5.62E-03
6.49E-01
1.17E-02
2.54E-04
7.76E-03
-9.99E+02
2.17E-03
4.08E-04
1.05E-03
3.09E-01
1.85E-01
1.24E-03
4.92E-03
2.24E-03
5.17E-03
4.55E-02
6.90E-01
5.44E-03
3.20E-04
3.57E-05
1.88E+00
1.07E-02
2.03E-01
3.90E-03
1.01E-03
7.89E-05
2.68E-05
2.13E-03
5.31 E-05
9.25E-03
1.40E-04
4.47E-02
7.52E-02
1.45E-04
6.02E-04
2.33E-03
3.50E-04
1.76E-03
Soil/GW
Temperature
rn
12.5
12.5
12.5
12.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
7.5
17.5
17.5
17.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
22.5
HG
Environment
8
8
8
1
2
2
2
2
2
4
12
12
12
12
12
12
2
2
2
12
12
2
4
4
12
9
2
2
4
4
12
12
5
5
5
12
12
12
12
12
4
4
2
5
12
Nearest
Climate Center
46
46
46
100
48
48
48
48
48
48
48
48
48
49
49
49
50
50
50
50
50
51
51
51
51
51
52
52
52
52
52
53
53
53
53
54
54
54
54
54
55
55
56
56
57
Site
Weiahtina
11
1
1
22
30
11
11
1
1
1
1
11
1
1
30
1
30
11
1
1
1
30
11
1
1
1
3
30
3
1
11
11
1
30
11
1
1
30
1
1
1
1
2
1
1
D-61
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.4 Nationwide Database of Land Application Unit Sites
Site
Number
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
Area
(m2^
4.05E+01
3.64E+06
1.62E+04
1.21E+04
8.09E+03
1.01E+06
1.62E+05
2.43E+04
3.24E+03
1.28E+06
9.31 E+02
4.05E+04
4.05E+04
4.05E+04
1.21E+04
3.22E+04
4.05E+04
1.01E+04
8.09E+05
2.10E+03
2.02E+05
9.15E+05
2.83E+04
1.30E+05
8.09E+04
4.05E+04
1.54E+05
1.01E+05
1.21E+05
1.01E+05
2.19E+05
2.02E+04
1.21E+03
1.32E+05
1.19E+05
2.43E+05
1.54E+05
5.67E+02
4.05E+03
9.31 E+02
2.91 E+05
8.09E+01
1.62E+05
2.79E+03
7.28E+05
Depth
frrrt
5.57E-01
1.02E+00
2.02E-03
-9.99E+02
6.71 E-02
2.68E-03
5.03E-04
2.05E-07
2.80E-03
2.45E-03
9.72E-02
9.31 E-03
2.24E-03
4.02E-04
2.33E-03
4.70E-01
9.31 E-04
8.93E-02
1.90E-03
9.68E-02
6.83E-01
8.24E-04
6.71 E-03
7.30E-02
3.48E-04
2.79E-01
1.71E-01
2.66E-05
6.86E-01
7.52E-03
6.89E-03
3.35E-03
7.40E-04
4.29E-01
2.47E-09
7.44E-05
2.33E-01
3.17E-03
4.50E-04
-9.99E+02
6.46E-01
-9.99E+02
3.08E-08
2.70E-01
2.17E-01
Soil/GW
Temperature
rn
17.5
17.5
22.5
22.5
12.5
12.5
12.5
12.5
12.5
12.5
7.5
7.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
17.5
12.5
12.5
HG
Environment
2
2
2
4
1
5
5
5
4
4
4
4
1
1
1
12
12
12
12
12
5
1
1
1
1
1
1
4
1
1
1
2
2
2
12
1
1
4
4
4
4
4
4
4
6
Nearest
Climate Center
58
58
58
58
63
64
64
64
66
66
68
68
69
69
69
69
69
69
69
69
69
69
69
69
69
69
69
69
71
71
71
71
71
71
71
72
72
72
72
72
72
72
72
73
73
Site
Weiahtina
1
1
9
1
1
1
1
1
11
1
1
30
1
1
1
1
16
11
1
24
1
1
1
1
2
1
1
1
1
1
1
1
30
11
1
30
1
1
1
1
1
2
1
1
1
D-62
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.4 Nationwide Database of Land Application Unit Sites
Site
Number
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
Area
(m2^
8.09E+03
9.31 E+02
2.02E+04
1.42E+05
4.05E+05
4.05E+04
4.09E+04
8.09E+03
2.83E+05
1.21E+05
8.63E+05
3.28E+04
1.21E+04
4.61 E+05
1.52E+05
4.90E+05
4.05E+05
2.02E+01
6.03E+04
6.07E+04
3.34E+05
1.62E+04
1.34E+05
4.05E+06
1.62E+05
1.94E+05
6.07E+04
2.70E+05
8.09E+05
2.51 E+03
1.51E+06
1.21 E+03
3.52E+05
8.09E+03
6.07E+03
6.75E+05
5.26E+04
6.07E+04
1.62E+04
4.05E+03
9.31 E+03
7.42E+03
6.48E+03
8.09E+04
2.02E+05
Depth
frrrt
4.89E-03
1.98E-01
2.47E-05
3.52E-08
9.31 E-02
6.15E-03
6.09E-03
4.93E-05
2.24E-03
1.15E-05
1.25E-03
1.16E-01
1.56E-04
2.19E+00
-9.99E+02
1.04E-01
2.21 E-03
3.45E-02
4.20E-02
1.86E-03
5.63E-03
2.33E-01
1.76E+00
1.40E-03
1.16E+00
2.04E-01
7.75E-02
9.25E-06
3.65E-03
-9.99E+02
-9.99E+02
1.57E-02
-9.99E+02
-9.99E+02
3.38E-02
9.68E-04
1.18E+00
6.04E-01
2.26E-03
6.71 E-03
6.07E-03
6.84E-01
5.82E-02
6.98E-02
3.35E-04
Soil/GW
Temperature
rn
12.5
12.5
12.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
22.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
HG
Environment
6
9
2
12
12
2
2
2
4
12
12
5
12
12
12
12
12
1
1
1
1
1
1
1
2
2
4
4
4
12
12
12
10
1
1
1
1
1
1
1
1
1
1
1
4
Nearest
Climate Center
73
73
74
74
74
74
74
74
74
74
74
74
76
76
76
76
76
77
77
77
77
77
77
77
77
77
77
77
77
78
78
78
78
79
79
79
79
79
79
79
79
79
79
79
79
Site
Weiahtina
1
1
30
30
11
1
1
10
1
16
2
1
1
1
1
1
1
30
11
11
1
1
1
1
1
1
1
16
1
3
1
2
1
1
9
30
1
1
1
31
7
1
1
1
1
D-63
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.4 Nationwide Database of Land Application Unit Sites
Site
Number
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
Area
(m2^
1.65E+06
2.02E+05
4.61 E+05
2.18E+04
4.73E+03
4.05E+04
3.24E+02
5.67E+02
1.74E+03
2.43E+04
5.26E+04
3.24E+05
1.34E+05
1.34E+04
4.05E+03
1.62E+04
1.82E+06
4.05E+04
7.28E+05
2.43E+04
1.62E+04
2.43E+04
9.71 E+04
2.83E+04
1.62E+04
1.62E+05
4.05E+04
5.67E+03
2.43E+05
5.67E+04
6.88E+05
4.05E+04
2.43E+05
4.05E+02
2.02E+04
4.05E+01
5.26E+04
2.02E+06
2.02E+05
2.02E+04
6.48E+04
1.21E+06
1.54E+05
3.24E+05
1.21 E+05
Depth
frrrt
3.56E-03
1.12E-03
1.28E-02
-9.99E+02
2.71 E-02
1.84E-02
1.54E-05
1.76E-04
1.52E-01
1.12E-02
5.01 E-01
1.23E-02
5.64E-02
3.74E-07
9.76E-03
7.05E-01
4.59E-03
3.87E-01
1.62E-02
1.54E-02
1.86E-01
1.12E-02
3.89E-03
7.31 E-03
1.40E-01
1.12E-03
1.11E-04
1.66E-01
1.21 E-01
4.56E-03
6.58E-04
2.09E-02
7.44E-05
1.88E-01
5.10E-03
2.22E-02
8.54E-05
8.95E-04
5.21 E-03
2.17E-02
9.07E-01
6.20E-01
9.74E-01
1.01E+00
1.49E-04
Soil/GW
Temperature
rn
17.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
12.5
7.5
17.5
12.5
12.5
12.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
22.5
22.5
22.5
HG
Environment
4
4
2
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
1
1
12
2
2
2
12
12
12
12
12
12
4
5
5
5
5
12
12
12
12
10
Nearest
Climate Center
79
79
80
80
80
80
81
81
81
81
81
81
81
81
81
81
81
81
81
81
81
81
81
83
84
85
88
88
88
89
89
89
89
89
89
90
90
90
90
90
91
91
91
91
91
Site
Weiahtina
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
2
1
1
1
1
1
1
30
1
30
11
1
1
1
1
2
2
1
30
1
7
30
1
1
1
1
1
1
D-64
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.4 Nationwide Database of Land Application Unit Sites
Site
Number
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
Area
(m2^
2.63E+03
7.45E+03
8.09E+03
2.79E+04
4.05E+04
6.07E+05
5.58E+05
5.26E+05
2.83E+04
2.02E+06
3.04E+06
1.05E+04
5.34E+05
4.05E+05
4.65E+05
1.21E+05
2.02E+04
8.22E+05
5.67E+04
1.62E+05
3.24E+03
2.02E+04
2.02E+04
9.31 E+04
2.16E+02
1.21E+05
1.62E+04
2.02E+06
3.64E+05
4.05E+05
1.42E+05
8.09E+03
2.51 E+04
8.09E+03
4.05E+03
1.62E+04
4.86E+04
2.69E+05
2.89E+05
1.01E+03
2.23E+05
Depth
frrrt
1.72E-02
5.11E-01
3.38E-01
3.87E-02
2.51 E-03
5.97E-03
7.97E-04
2.68E-02
1.60E-03
4.47E-03
1.49E-05
5.31 E-03
-9.99E+02
-9.99E+02
3.84E-02
3.10E-02
1.13E-01
2.40E-04
1.13E-01
2.02E-04
1.54E-06
3.00E-02
2.42E-02
9.47E-01
9.40E-01
7.13E-01
2.01 E-02
1.79E-03
4.14E-02
7.46E-05
1.46E-03
1.68E-02
3.30E-02
9.40E-02
9.04E-01
1.85E-05
-9.99E+02
8.71 E-04
1.30E-02
3.58E-02
1.65E-03
Soil/GW
Temperature
rn
17.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
17.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
22.5
HG
Environment
4
4
4
4
4
4
4
5
1
1
1
4
4
4
4
4
4
4
12
12
12
10
1
1
1
1
1
4
12
12
12
4
4
4
4
4
4
4
4
4
4
Nearest
Climate Center
92
92
92
92
92
92
92
92
93
93
93
93
93
93
93
93
93
93
93
93
93
94
95
95
95
95
95
95
95
95
95
96
96
96
96
96
96
96
96
96
96
Site
Weiahtina
1
1
2
1
1
7
1
1
1
1
1
1
1
1
1
1
1
1
1
1
7
1
1
1
1
7
7
1
1
1
1
3
1
1
9
30
11
1
1
1
1
D-65
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.5 Hydrogeologic Database for HG Environment 1
Subsurface Environment Description
Metamorphic and Igneous
Hydraulic
Conductivity
(m/vh
-999
3.15E+00
-999
-999
-999
9.46E+02
1.58E+03
6.31 E+01
3.47E+03
2.84E+01
1.26E+02
1.58E+01
3.15E+02
-999
1.10E+04
9.46E+01
-999
7.57E+03
6.31 E+00
6.31 E+00
3.15E+01
3.15E+01
-999
Unsaturated Zone
Thickness
frrrt
2.59E+01
1.68E+01
1.52E+01
6.10E+02
5.79E+00
4.57E+00
3.05E+00
4.88E+00
6.10E+00
2.04E+00
6.10E+00
3.81 E+00
2.13E+01
6.10E+00
3.05E+00
1.83E+00
1.22E+00
1.52E+00
9.14E-01
1.83E+00
6.10E+00
3.05E-01
9.14E+00
Saturated Zone
Thickness
(m)
-999
1.52E+02
1.52E+01
-999
9.14E+00
-999
-999
1.22E+01
1.52E+02
9.14E+00
7.32E+00
3.29E+01
3.05E+00
6.10E+00
1.83E+01
4.27E+00
9.14E+00
3.05E+00
6.10E+00
7.62E+00
-999
6.10E+00
1.52E+02
Regional Hydraulic
Gradient
(m/m)
1.66E-02
-999
-999
1.00E-04
5.00E-02
1.40E-02
1.40E-02
7.00E-02
3.00E-02
1.00E-02
3.00E-02
9.00E-02
-999
7.00E-06
2.00E-02
4.00E-02
1.00E-02
7.00E-06
3.80E-02
1.00E-01
6.00E-02
5.00E-03
8.00E-03
Note: -999 indicates a missing sample value.
D-66
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.6 Hydrogeologic Statistics for HG Environment 1
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Metamorphic and Igneous
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-8.52129
Unsatu rated
Zone Thickness
In(ft)
2.81441
Saturated Zone
Thickness
In(ft)
3.76962
Regional
Hydraulic
Gradient
(m/m
-3.97399
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
6.82319
1 .07478
1 .80348
-0.39418
Unsatu rated
Zone Thickness
ln(ft)
0.8005
0.55257
0.4367
Saturated Zone
Thickness
ln(ft)
1.1956
0.17788
Regional
Hydraulic
Gradient
(m/m
0.81424
Table D.7 Hydrogeologic Database for HG Environment 2
Subsurface Environment Description
Bedded Sedimentary Rock
Hydraulic
Conductivity
(m/yr)
6.31 E+01
2.84E+01
1.89E+03
5.99E+03
3.15E+02
3.15E+01
1.58E+03
3.15E+02
2.21 E+01
2.84E+02
9.46E+00
2.21 E+02
3.15E+00
3.15E+00
2.21 E+03
Unsatu rated Zone
Thickness
(m)
6.10E+00
6.10E+00
7.65E+01
3.05E+01
6.55E+01
1.52E+01
1.74E+02
5.97E+00
1.22E+01
1.68E+01
6.10E+00
9.14E+00
3.96E+00
4.57E+00
1.52E+01
Saturated Zone
Thickness
(m)
2.29E+01
7.93E+01
-999
1.83E+02
4.57E+01
2.13E+01
3.05E+01
3.60E+00
1.07E+01
3.05E+00
1.52E+02
-999
4.57E+00
9.14E+01
3.05E+01
Regional Hydraulic
Gradient
(m/m)
8.00E-02
-999
8.00E-03
1.00E-03
5.70E-03
1.00E-01
-999
-999
2.80E-02
3.20E-03
3.10E-02
8.00E-03
1.00E-02
1.00E-03
3.30E-02
D-67
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.7 Hydrogeologic Database for HG Environment 2
Subsurface Environment Description
Bedded Sedimentary Rock
Hydraulic
Conductivity
(m/yr)
1.10E+04
1.26E+02
1.33E+03
3.15E+04
-999
1.89E+03
9.78E+03
6.31 E+00
3.15E+00
1.26E+01
2.21 E+07
3.47E+04
3.15E+04
3.15E+00
3.15E+02
3.15E+02
-999
-999
6.31 E+01
1.89E+02
2.21 E+07
-999
2.21 E+01
1.89E+02
1.10E+04
-999
6.31 E+01
1.26E+02
-999
Unsatu rated Zone
Thickness
(m)
1.83E+01
1.34E+01
6.10E+00
1.83E+00
4.27E+00
5.36E+01
1.83E+01
1.22E+01
1.22E+01
3.70E+00
9.14E+00
1.22E+01
1.52E+01
3.66E+00
9.14E+00
8.53E+00
4.88E+00
3.05E+00
4.57E+00
6.10E+00
4.57E+00
1.83E+02
2.74E+00
1.52E+01
1.52E+01
3.66E+00
8.23E+00
4.57E+00
1.52E+00
Saturated Zone
Thickness
(m)
9.14E+01
7.62E+00
2.13E+01
3.05E+00
8.90E+01
6.10E+00
3.05E+01
2.44E+01
1.22E+01
3.00E+01
1.52E+00
4.57E+00
6.10E+00
9.14E+00
2.13E+01
1.90E+01
-999
-999
1.98E+01
6.10E+01
1.83E+00
1.22E+01
3.05E+00
6.10E+01
2.29E+01
1.83E+01
5.18E+02
1.07E+02
9.14E+01
Regional Hydraulic
Gradient
(m/m)
-999
4.00E-03
5.00E-03
-999
-999
4.30E-02
1.20E-02
1.50E-02
2.50E-02
1.00E-02
1.00E+00
8.00E-03
5.00E-02
4.00E-02
5.00E-03
2.50E-02
-999
2.40E-02
4.00E-02
2.30E-02
1.00E+00
4.00E-04
-999
1.20E-02
5.00E-04
-999
7.00E-03
3.00E-02
-999
Note: -999 indicates a missing sample value.
D-68
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.8 Hydrogeologic Statistics for HG Environment 2
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Bedded Sedimentary Rock
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-7.68877
Unsatu rated
Zone Thickness
In(ft)
3.4698
Saturated Zone
Thickness
In(ft)
4.2618
Regional
Hydraulic
Gradient
(m/rrf
-4.42479
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
12.3279
1.32509
0.47331
-1.46902
Unsatu rated
Zone Thickness
In(ft)
0.54208
-0.01357
-0.1757
Saturated Zone
Thickness
ln(ft)
1.61831
-0.39626
Regional
Hydraulic
Gradient
(m/rrf
1.75145
Table D.9 Hydrogeologic Database for HG Environment 3
Subsurface Environment Description
Bedded Sedimentary Rock
Hydraulic
Conductivity
(m/vh
2.55E+04
9.46E+02
1.26E+03
2.84E+01
3.78E+03
2.68E+03
3.15E+01
-999
6.31 E+01
6.62E+03
1.26E+02
3.15E+01
8.83E+03
1.58E+02
6.31 E+00
9.46E+00
Unsatu rated Zone
Thickness
frrrt
3.66E+00
9.14E+00
1.77E+00
6.10E+00
1.68E+01
6.71 E+00
9.45E+00
7.62E+00
2.30E+00
3.05E+01
3.06E+00
-999
5.33E+00
9.14E-01
1.37E+00
2.56E+00
Saturated Zone
Thickness
frrrt
3.66E+00
5.33E+00
6.10E+00
-999
1.52E+00
2.44E+00
-999
-999
4.12E+00
2.13E+01
1.52E+01
-999
4.57E+01
4.57E+00
3.66E+00
2.74E+00
Regional Hydraulic
Gradient
(m/rrrt
9.00E-04
5.00E-03
4.00E-09
3.40E-02
4.00E-02
9.00E-03
5.00E-02
1.00E-02
7.00E-03
2.00E-02
1.00E-02
1.00E-02
5.00E-04
3.00E-03
2.70E-02
4.20E-02
Note: -999 indicates a missing sample value.
D-69
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.10 Hydrogeologic Statistics for HG Environment 3
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Bedded Sedimentary Rock
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-7.81342
Unsatu rated
Zone Thickness
In(ft)
2.72776
Saturated Zone
Thickness
In(ft)
2.93298
Regional
Hydraulic
Gradient
(m/m
-4.6888
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s
21.2765
2.78074
0.6463
-1.30916
Unsatu rated
Zone Thickness
ln(ft)
1 .07038
0.17468
0.29718
Saturated Zone
Thickness
ln(ft)
0.96341
-0.64536
Regional
Hydraulic
Gradient
(m/m
1 .9708
Table D.11 Hydrogeologic Database for HG Environment 4
Subsurface Environment Description
Sand and Gravel
Hydraulic
Conductivity
(m/yr)
5.08E+04
1.39E+04
-999
-999
1.58E+03
3.15E+00
1.26E+01
-999
2.52E+03
3.15E+03
9.46E+00
9.46E+01
-999
1.16E+05
1.26E+04
Unsatu rated Zone
Thickness
(m)
4.57E+00
-999
6.10E+00
1.22E+01
2.13E+00
1.98E+01
4.57E+00
9.14E-01
1.52E+00
2.44E+00
1.83E+00
6.10E-01
6.98E+00
1.52E+01
7.62E+00
Saturated Zone
Thickness
(m)
9.14E+00
3.35E+01
-999
4.57E+00
1.22E+01
2.44E+00
1.07E+01
6.10E+00
3.05E+00
-999
6.04E+00
3.96E+00
5.33E+01
7.62E+01
6.40E+00
Regional Hydraulic
Gradient
(m/m)
5.00E-03
2.80E-02
-999
1.00E-02
1.00E-03
7.00E-03
7.00E-02
4.30E-02
2.00E-02
2.00E-06
5.50E-02
6.00E-03
-999
4.00E-03
4.90E-02
D-70
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.11 Hydrogeologic Database for HG Environment 4
Subsurface Environment Description
Sand and Gravel
Hydraulic
Conductivity
(m/yr)
4.10E+03
-999
-999
3.15E+03
2.21 E+02
-999
3.15E+00
6.31 E+02
-999
-999
3.15E+01
3.15E+02
4.42E+03
6.31 E+02
-999
-999
7.88E+03
5.36E+03
Unsatu rated Zone
Thickness
(m)
2.13E+00
1.07E+01
6.10E-01
3.05E-01
1.52E+00
4.57E+00
3.05E+00
2.44E+00
5.08E+01
1.52E+01
3.35E+01
9.14E+00
1.52E+00
2.21 E+00
1.22E+00
9.14E+00
2.29E+01
3.05E+00
Saturated Zone
Thickness
(m)
3.20E+01
8.53E+00
7.62E+00
9.14E+00
7.62E+00
2.74E+01
3.05E+00
7.62E+00
1.45E+02
6.10E+00
-999
3.05E+00
1.98E+01
3.32E-01
-999
3.05E+00
3.05E+00
6.10E+00
Regional Hydraulic
Gradient
(m/m)
3.00E-03
6.00E-04
1.00E-03
3.00E-03
4.00E-03
1.50E-02
2.00E-02
5.00E-03
9.20E-02
1.00E-07
2.30E-02
2.00E-03
2.00E-03
1.00E-03
-999
5.00E-03
2.00E-02
1.00E-03
Note: -999 indicates a missing sample value.
D-71
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.12 Hydrogeologic Statistics for HG Environment 4
Hydraulic
Conductivity
ln(cm/s]
Unsaturated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Sand and Gravel
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-6.82634
Unsaturated
Zone Thickness
In(ft)
2.65875
Saturated Zone
Thickness
In(ft)
3.3063
Regional
Hydraulic
Gradient
(m/m
-4.9212
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
9.60704
0.51036
1.46619
-1.4956
Unsaturated
Zone Thickness
In(ft)
1.5223
-0.01024
0.0939
Saturated Zone
Thickness
ln(ft)
1.28413
-0.02391
Regional
Hydraulic
Gradient
(m/m
1 .83998
Table D.13 Hydrogeologic Database for HG Environment 5
Subsurface Environment Description
Alluvial Basins Valleys & Fans
Hydraulic
Conductivity
(m/yr)
5.68E+03
-999
9.46E+02
-999
1.58E+05
6.31 E+04
-999
1.56E+01
1.26E+05
-999
7.57E+03
-999
1.58E+03
3.15E+04
-999
6.31 E+00
-999
Unsaturated Zone
Thickness
(m)
3.05E+00
9.14E-01
-999
3.05E+00
6.10E+00
5.18E+00
6.10E+00
3.81 E+01
4.57E+00
4.57E+00
3.05E+01
1.01E+02
3.35E+01
3.05E+01
9.75E+00
3.38E+00
3.29E+01
Saturated Zone
Thickness
(m)
2.13E+01
3.96E+00
1.52E+01
6.10E+00
3.05E+00
1.52E+00
3.05E+00
1.52E+00
4.57E+00
2.29E+01
-999
1.52E+01
9.14E+02
2.44E+01
1.52E+01
7.62E+00
4.57E+00
Regional Hydraulic
Gradient
(m/m)
2.00E-03
-999
9.30E-02
1.00E-02
1.00E-04
5.00E-03
5.00E-03
2.50E-02
1.00E-03
3.00E-02
-999
5.00E-02
1.00E-03
1.00E-03
-999
3.00E-03
-999
D-72
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.13 Hydrogeologic Database for HG Environment 5
Subsurface Environment Description
Alluvial Basins Valleys & Fans
Hydraulic
Conductivity
(m/yr)
2.37E+04
-999
1.58E+03
1.26E+03
3.15E+03
1.26E+02
9.46E+02
-999
-999
1.39E+03
-999
-999
-999
-999
9.46E+01
2.84E+03
1.58E+02
-999
1.26E+03
6.31 E+01
1.58E+04
3.47E+03
-999
1.26E+02
2.21 E+03
3.15E+00
-999
-999
6.37E+04
3.15E+00
-999
6.31 E+02
3.19E+06
3.15E+03
3.15E+00
9.46E+02
3.15E+03
3.15E+02
1.10E+04
-999
-999
1.26E+01
Unsaturated Zone
Thickness
(m)
4.27E+01
1.07E+01
1.98E+01
2.44E+00
1.22E+01
1.52E+01
3.05E+00
4.57E+00
2.44E+00
3.41 E+01
1.22E+01
3.66E+00
2.74E+01
1.59E+01
7.01 E+00
4.27E+01
1.30E+01
1.83E+01
7.32E+00
8.23E+01
3.66E+01
7.62E+00
1.22E+01
1.83E+00
1.52E+01
3.66E+00
1.22E+01
3.66E+01
6.10E+01
6.10E+01
7.01 E+00
1.46E+01
9.14E+00
1.07E+01
4.72E+00
1.37E+01
7.62E+00
4.88E+00
2.44E+00
2.44E+00
3.96E+00
2.13E+00
Saturated Zone
Thickness
(m)
6.10E+00
1.07E+00
2.44E+01
-999
3.81 E+00
4.57E+00
3.05E+00
-999
-999
9.14E+01
8.53E+01
-999
-999
1.62E+01
9.14E+00
3.05E+01
1.30E+02
3.66E+00
1.83E+01
-999
-999
1.52E+01
1.52E+01
1.10E+01
9.14E+00
2.44E+00
4.88E+01
-999
-999
1.52E+01
1.83E+01
2.44E+01
3.05E-01
3.05E+00
1.83E+01
6.10E+00
7.62E+00
9.14E+00
6.10E+00
5.18E+00
1.83E+01
6.10E-01
Regional Hydraulic
Gradient
(m/m)
3.00E-03
-999
5.00E-03
-999
-999
2.00E-03
2.00E-03
-999
-999
3.00E-03
-999
-999
6.00E-03
4.00E-04
3.00E-04
2.00E-03
1.00E-03
1.00E-02
1.00E-04
-999
1.00E-03
2.00E-02
1.00E-03
2.00E-03
-999
5.00E-03
1.00E-02
6.80E-02
-999
1.50E-02
-999
3.00E-03
2.00E-06
6.00E-03
7.00E-02
8.00E-03
-999
1.70E-02
-999
4.00E-02
-999
-999
D-73
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.13 Hydrogeologic Database for HG Environment 5
Subsurface Environment Description
Alluvial Basins Valleys & Fans
Hydraulic
Conductivity
(m/yr)
2.21 E+03
-999
2.21 E+04
Unsaturated Zone
Thickness
(m)
9.14E+00
3.05E+00
6.10E+00
Saturated Zone
Thickness
(m)
1.52E+00
6.10E+00
9.14E+01
Regional Hydraulic
Gradient
(m/m)
2.50E-02
1.30E-02
1.00E-03
Note: -999 indicates a missing sample value.
Table D.14 Hydrogeologic Statistics for HG Environment 5
Hydraulic
Conductivity
ln(cm/s]
Unsaturated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Alluvial Basins Valleys & Fans
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-5.61434
Unsaturated
Zone Thickness
In(ft)
3.43835
Saturated Zone
Thickness
In(ft)
3.53678
Regional
Hydraulic
Gradient
(m/m]
-5.61773
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s;
9.98295
0.28014
0.08839
2.96927
Unsaturated
Zone Thickness
In(ft)
0.8396
0.54136
0.0448
Saturated Zone
Thickness
In(ft)
2.05569
-0.71488
Regional
Hydraulic
Gradient
(m/m]
4.17328
D-74
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.15 Hydrogeologic Database for HG Environment 6
Subsurface Environment Description
River Valleys and Flood Plains with overbank def
Hydraulic
Conductivity
(m/yr)
-999
-999
3.15E+02
6.31 E+02
1.07E+05
1.89E+03
3.15E+00
-999
4.10E+03
1.67E+04
1.10E+04
3.15E+02
-999
1.10E+04
-999
-999
1.58E+03
3.31 E+04
-999
2.52E+02
1.42E+04
3.15E+03
5.68E+03
1.89E+03
3.15E+02
3.15E+01
3.15E+03
1.55E+04
5.52E+03
3.15E+03
1.58E+02
2.21 E+01
-999
9.46E+00
-999
-999
Unsaturated Zone
Thickness
(m)
1.52E+01
1.83E+00
4.88E+00
8.53E+00
3.51 E+00
2.44E+01
2.74E+00
2.13E+01
2.74E+01
2.44E+00
5.49E+00
1.52E+00
1.22E+00
5.79E+00
3.96E+00
1.22E+01
4.57E+00
3.05E+01
4.57E+00
1.15E+01
4.57E+00
1.52E+00
3.05E+00
3.66E+00
3.66E+00
1.52E+00
1.19E+00
5.18E+00
3.66E+00
3.05E+00
1.52E+00
1.22E+00
1.83E+00
9.14E-01
1.07E+01
1.22E+01
Saturated Zone
Thickness
(m)
1.83E+01
9.14E+00
1.52E+01
9.14E+00
7.32E+00
3.66E+01
3.66E+00
7.62E+00
3.05E+00
6.40E+00
1.31 E+01
3.05E+00
1.83E+00
-999
4.27E+00
1.68E+01
7.62E+00
2.29E+01
7.62E+00
-999
1.83E+01
1.52E+00
6.10E+00
6.10E+00
6.10E-01
-999
3.66E+00
7.93E+00
5.49E+00
1.68E+01
3.05E+00
1.37E+01
9.14E+00
6.10E+00
1.52E+01
1.22E+01
josits
Regional Hydraulic
Gradient
(m/m)
5.00E-03
2.00E-03
1.00E-03
1.00E-02
5.00E-03
1.00E-03
3.00E-03
1.00E-03
1.00E-03
4.00E-03
2.00E-03
2.00E-03
8.00E-03
5.00E-04
1.70E-02
2.00E-03
4.00E-02
1.00E-02
1.00E-01
5.00E-03
7.00E-04
4.00E-07
1.00E-03
2.00E-03
1.00E-06
2.00E-08
-999
6.00E-03
1.00E-02
1.30E-02
1.20E-02
4.00E-03
1.10E-02
8.00E-03
8.00E-05
1.00E-06
Note: -999 indicates a missing sample value.
D-75
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.16 Hydrogeologic Statistics for HG Environment 6
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
River Valleys and Flood Plains with overbank deposits
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-6.7624
Unsatu rated
Zone Thickness
In(ft)
2.65846
Saturated Zone
Thickness
In(ft)
3.15814
Regional
Hydraulic
Gradient
(m/m
-5.6184
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
13.8058
1 .67704
2.14642
-0.09303
Unsatu rated
Zone Thickness
ln(ft)
0.8987
0.34951
-0.23716
Saturated Zone
Thickness
ln(ft)
0.86919
0.00252
Regional
Hydraulic
Gradient
(m/m
1.23921
Table D.17 Hydrogeologic Database for HG Environment 7
Subsurface Environment Description
River Valleys and Flood Plains without overbank deposits
Hydraulic
Conductivity
(m/yr)
9.46E+02
1.26E+03
-999
6.94E+03
2.33E+04
4.42E+03
5.61 E+04
5.52E+04
9.46E+03
-999
-999
9.46E+02
9.78E+03
-999
4.42E+03
4.42E+03
Unsaturated Zone
Thickness
(m)
2.44E+00
2.13E+00
3.54E+01
-999
1.52E+01
1.83E+00
3.05E+00
3.05E+00
5.79E+01
9.14E+00
1.22E+01
3.05E+00
3.05E+00
5.18E+00
3.66E+00
2.44E+01
Saturated Zone
Thickness
(m)
8.23E+00
3.05E+02
-999
2.29E+01
3.66E+01
3.81 E+01
1.01E+01
6.10E+01
9.14E+00
9.14E+00
9.14E+00
3.05E+00
3.05E+00
1.22E+01
1.52E+01
2.13E+01
Regional Hydraulic
Gradient
(m/m)
2.00E-03
3.00E-03
-999
3.00E-03
4.00E-03
7.00E-04
2.00E-03
-999
1.00E-06
2.00E-04
2.00E-03
8.00E-03
1.30E-02
2.00E-03
5.00E-03
1.00E-02
D-76
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.17 Hydrogeologic Database for HG Environment 7
Subsurface Environment Description
River Valleys and Flood Plains without overbank deposits
Hydraulic
Conductivity
(m/yr)
1.58E+03
8.20E+04
9.46E+02
1.10E+04
-999
6.94E+03
6.31 E+03
2.37E+04
1.77E+04
1.89E+03
1.45E+04
1.20E+05
2.52E+03
1.26E+01
3.15E+02
3.15E+01
-999
Unsaturated Zone
Thickness
(m)
1.52E+00
1.49E+01
1.22E+01
3.05E+00
4.57E+00
2.13E+00
7.01 E+00
4.88E+00
5.79E+00
4.57E+00
1.52E+00
2.20E+01
1.52E+00
5.79E+00
6.10E-01
4.57E-01
4.57E+01
Saturated Zone
Thickness
(m)
2.44E+01
8.53E+00
1.83E+01
4.57E+00
1.37E+01
7.99E+00
5.18E+00
1.83E+01
4.27E+01
1.07E+01
1.83E+01
-999
6.10E+00
4.27E+00
4.57E+00
-999
3.05E+00
Regional Hydraulic
Gradient
(m/m)
1.00E-02
3.00E-03
2.00E-06
-999
1.00E-02
4.00E-03
4.90E-02
3.30E-02
2.00E-03
4.00E-06
1.20E-02
1.00E-02
1.10E-02
2.10E-02
6.00E-03
1.00E-03
-999
Note: -999 indicates a missing sample value.
D-77
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.18 Hydrogeologic Statistics for HG Environment 7
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
River Valleys and Flood Plains without overbank deposits
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-5.22204
Unsatu rated
Zone Thickness
In(ft)
2.81441
Saturated Zone
Thickness
In(ft)
3.78819
Regional
Hydraulic
Gradient
(m/m
-5.30668
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
13.0649
-1.10808
0.50353
-0.73884
Unsatu rated
Zone Thickness
ln(ft)
1.13841
0.0496
0.26902
Saturated Zone
Thickness
ln(ft)
1.11517
-0.46202
Regional
Hydraulic
Gradient
(m/m
1.11713
Table D.19 Hydrogeologic Database for HG Environment 8
Subsurface Environment Description
Outwash
Hydraulic
Conductivity
(m/yr)
6.31 E+03
2.40E+04
3.00E+04
-999
2.52E+03
1.10E+05
1.33E+04
3.78E+04
1.26E+03
2.21 E+03
9.78E+03
1.89E+03
3.44E+04
4.42E+04
1.58E+04
7.25E+03
Unsatu rated Zone
Thickness
(m)
7.62E+00
4.88E+00
2.99E+00
1.22E+01
3.05E+00
9.14E+00
5.49E+00
4.57E+00
1.07E+01
3.05E+00
3.35E+00
4.88E+01
7.62E+00
4.88E+00
2.90E+01
9.14E+00
Saturated Zone
Thickness
(m)
6.10E+01
2.29E+01
1.89E+01
6.71 E+00
2.13E+01
2.13E+01
1.22E+01
9.14E+00
-999
2.29E+01
1.52E+01
3.20E+01
2.62E+01
1.86E+01
2.44E+01
3.96E+01
Regional Hydraulic
Gradient
(m/m)
1.00E-03
2.00E-03
4.00E-03
1.00E-03
8.00E-07
4.00E-03
6.00E-03
3.00E-03
8.00E-03
9.00E-04
7.00E-04
3.00E-02
6.00E-03
2.00E-03
1.00E-03
6.00E-04
D-78
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.19 Hydrogeologic Database for HG Environment 8
Subsurface Environment Description
Outwash
Hydraulic
Conductivity
(m/yr)
1.39E+04
2.90E+04
9.97E+04
-999
1.48E+04
7.88E+03
-999
5.68E+03
1.89E+04
3.88E+03
-999
4.73E+02
1.04E+04
2.21 E+04
2.78E+04
2.78E+04
-999
1.10E+04
1.92E+04
6.31 E+02
1.92E+04
5.05E+03
-999
3.31 E+04
-999
2.21 E+03
6.09E+04
Unsatu rated Zone
Thickness
(m)
1.22E+01
2.74E+00
2.13E+00
4.57E+00
1.83E+00
2.44E+00
1.52E+01
2.44E+00
4.57E+00
3.66E+00
2.20E+01
6.10E+00
7.62E+00
9.14E+00
7.62E+00
7.62E+00
6.10E+00
1.22E+01
5.33E+00
9.14E-01
1.83E+01
6.10E-01
7.62E+00
1.52E+01
4.57E+00
2.13E+00
2.00E+01
Saturated Zone
Thickness
(m)
1.22E+02
1.01E+01
7.01 E+00
6.10E+00
6.10E+01
3.05E+00
7.62E+01
6.10E+00
7.62E+00
7.62E+00
1.83E+01
4.57E+00
3.05E+01
7.62E+00
2.44E+01
2.44E+01
4.57E+00
3.05E+00
1.22E+01
1.07E+01
1.07E+01
1.22E+01
3.05E+01
3.05E+01
2.29E+01
3.66E+00
3.05E+01
Regional Hydraulic
Gradient
(m/m)
2.00E-03
-999
7.00E-04
3.00E-03
1.00E-03
3.00E-02
9.00E-04
1.00E-03
5.00E-03
4.00E-03
6.00E-04
1.70E-02
1.00E-03
5.00E-03
2.00E-03
2.00E-03
4.00E-05
7.50E-02
8.00E-03
1.00E-02
1.30E-02
3.00E-03
2.00E-03
4.00E-04
1.00E-02
2.00E-02
3.00E-03
Note: -999 indicates a missing sample value.
D-79
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.20 Hydrogeologic Statistics for HG Environment 8
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Outwash
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-3.59646
Unsatu rated
Zone Thickness
In(ft)
2.97372
Saturated Zone
Thickness
In(ft)
3.92385
Regional
Hydraulic
Gradient
(m/m
-5.8651 1
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
5.02
0.4862
0.1547
-0.8019
Unsatu rated
Zone Thickness
ln(ft)
0.85551
0.26963
0.07004
Saturated Zone
Thickness
ln(ft)
0.75329
-0.62236
Regional
Hydraulic
Gradient
(m/m
1.62199
Table D.21 Hydrogeological Database for HG Environment 9
Subsurface Environment Description
Till and Till over outwash
Hydraulic
Conductivity
(m/yr)
9.46E+02
3.15E+02
1.89E+01
2.18E+04
3.47E+03
3.15E+03
1.26E+02
3.15E+01
-999
3.15E+01
3.15E+02
6.31 E+01
9.15E+02
-999
1.89E+03
3.15E+03
6.31 E+02
Unsaturated Zone
Thickness
(m)
2.10E+00
1.37E+01
3.66E+00
6.10E+00
3.96E+01
2.13E+01
1.00E+00
7.62E+00
3.05E+00
5.18E+00
3.96E+00
4.57E+00
2.44E+00
7.32E+00
1.83E+00
7.62E+00
3.66E+00
Saturated Zone
Thickness
(m)
1.37E+01
1.22E+01
5.49E+00
1.52E+01
5.49E+01
4.57E+00
3.00E+01
3.05E+00
3.05E+01
1.07E+01
2.29E+01
2.96E+00
1.22E+01
1.22E+01
9.14E-01
7.62E+00
2.13E+00
Regional Hydraulic
Gradient
(m/m)
5.00E-02
1.00E-03
8.00E-03
4.00E-03
1.70E-02
1.00E-02
-999
9.00E-03
5.00E-07
3.00E-02
7.00E-03
2.20E-02
7.00E-04
-999
5.00E-03
-999
-999
D-80
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.21 Hydrogeological Database for HG Environment 9
Subsurface Environment Description
Till and Till over outwash
Hydraulic
Conductivity
(m/yr)
6.31 E+03
-999
4.10E+03
1.26E+02
1.26E+02
-999
1.26E+01
8.83E+03
3.15E+02
2.84E+02
9.46E+00
1.58E+03
Unsaturated Zone
Thickness
(m)
2.44E+00
2.13E+00
1.52E+00
3.05E+00
3.05E+00
6.10E-01
1.83E+00
1.52E+00
1.52E+00
1.74E+00
1.83E+01
3.35E+00
Saturated Zone
Thickness
(m)
9.14E+00
7.62E+00
6.10E+00
4.57E+00
7.62E+00
1.83E+00
-999
1.83E+01
6.10E+00
9.14E+00
2.44E+00
6.10E+00
Regional Hydraulic
Gradient
(m/m)
4.00E-08
9.00E-03
1.00E-02
5.00E-02
2.00E-02
-999
4.00E-02
4.00E-03
-999
1.00E-02
3.00E-03
4.00E-06
Note: -999 indicates a missing sample value.
Table D.22 Hydrogeologic Statistics for HG Environment 9
Hydraulic
Conductivity
ln(cm/s]
Unsaturated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Till and Till over outwash
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-7.67984
Unsaturated
Zone Thickness
In(ft)
2.48552
Saturated Zone
Thickness
In(ft)
3.22796
Regional
Hydraulic
Gradient
(m/m
-4.68545
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s
1 1 .259
0.17085
0.72472
-0.72109
Unsaturated
Zone Thickness
In(ft)
0.87319
0.13478
-0.12094
Saturated Zone
Thickness
In(ft)
0.81983
-0.0043
Regional
Hydraulic
Gradient
(m/m
1 .28625
D-81
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.23 Hydrogeologic Database for HG Environment 10
Subsurface Environment Description
Unconsolidated and Semiconsolidated Shallow Aquifers
Hydraulic
Conductivity
(m/yr)
-999
4.42E+03
2.84E+02
1.96E+04
1.58E+02
3.15E+02
-999
1.26E+02
3.15E+02
3.15E+01
1.26E+02
-999
-999
6.31 E+02
3.47E+03
2.21 E+03
-999
2.84E+03
-999
2.21 E+03
1.26E+02
-999
-999
3.15E+00
2.52E+01
4.42E+03
-999
Unsatu rated Zone
Thickness
(m)
3.35E+00
1.16E+01
4.57E+00
3.96E+01
4.57E+00
1.52E+00
6.10E+00
7.62E+00
1.52E+01
2.74E+00
3.05E+00
3.81 E+00
3.66E+00
4.57E+00
3.05E+00
2.59E+01
1.52E+00
2.74E+00
1.83E+00
1.37E+01
1.22E+01
3.81 E+00
3.32E+00
3.66E+00
1.83E+00
1.07E+01
6.10E+00
Saturated Zone
Thickness
(m)
1.46E+01
5.49E+01
7.62E+00
2.14E+01
3.05E+00
6.10E+00
3.66E+00
2.29E+00
1.07E+01
6.86E+00
4.12E+00
6.10E+00
1.52E+01
9.14E-01
3.05E+00
7.62E+00
1.52E+01
4.57E+00
2.44E+00
7.62E+00
1.22E+01
1.68E+01
1.83E+00
1.16E+01
4.57E+00
9.14E+00
4.27E+01
Regional Hydraulic
Gradient
(m/m)
3.00E-02
5.00E-03
1.00E-02
3.00E-04
6.00E-04
4.00E-03
1.00E-06
5.00E-03
1.00E-02
1.70E-02
3.00E-03
1.00E-05
1.00E-01
5.00E-03
2.00E-03
1.00E-05
2.00E-03
-999
8.00E-03
1.00E-02
2.50E-02
2.00E-03
6.00E-02
1.00E-02
9.50E-03
1.40E-02
1.75E-03
Note: -999 indicates a missing sample value.
D-82
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.24 Hydrogeologic Statistics for HG Environment 10
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Unconsolidated and Semiconsolidated Shallow Aquifers
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-6.97635
Unsatu rated
Zone Thickness
In(ft)
2.80942
Saturated Zone
Thickness
In(ft)
3.15655
Regional
Hydraulic
Gradient
(m/m
-5.57335
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
4.99889
1 .27993
0.51266
-1.74813
Unsatu rated
Zone Thickness
ln(ft)
0.86035
0.40799
-0.71454
Saturated Zone
Thickness
ln(ft)
0.8467
0.03369
Regional
Hydraulic
Gradient
(m/m
3.61694
Table D.25 Hydrogeologic Database for HG Environment 11
Subsurface Environment Description
Coastal Beaches
Hydraulic
Conductivity
(m/yr)
9.46E+02
6.31 E+01
7.25E+03
2.43E+04
-999
7.57E+03
1.26E+04
6.31 E+02
3.15E+03
1.26E+03
3.15E+01
1.39E+04
-999
2.52E+03
1.26E+03
-999
Unsaturated Zone
Thickness
(m)
2.13E+00
2.74E+00
9.14E+00
4.57E+00
1.52E+00
3.05E+00
9.14E-01
9.14E-01
1.52E+00
1.22E+00
9.14E-01
1.52E+00
1.68E+00
2.00E+00
1.22E+00
9.14E-01
Saturated Zone
Thickness
(m)
3.05E+02
3.05E+01
3.66E+01
1.07E+01
3.05E+02
4.57E+01
4.57E+00
6.10E+00
6.10E+00
1.07E+01
1.52E+01
6.10E+01
1.52E+01
2.00E+00
3.05E+00
7.62E+00
Regional Hydraulic
Gradient
(m/m)
1.00E-02
3.00E-02
6.00E-04
6.80E-03
1.00E-03
6.00E-03
5.00E-03
1.00E-02
-999
2.00E-03
5.00E-03
2.00E-03
2.00E-03
2.00E-03
1.70E-02
-999
D-83
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.25 Hydrogeologic Database for HG Environment 11
Subsurface Environment Description
Coastal Beaches
Hydraulic
Conductivity
(m/yr)
3.15E+02
1.58E+03
-999
3.15E+02
2.84E+02
9.46E+02
-999
8.17E+03
-999
-999
Unsaturated Zone
Thickness
(m)
1.52E+00
2.74E+00
3.35E+00
3.05E+00
1.07E+00
2.13E+00
2.74E+00
7.01 E+00
-999
3.05E+00
Saturated Zone
Thickness
(m)
1.52E+00
4.57E+00
4.27E+00
2.44E+01
3.05E+01
1.68E+00
2.13E+01
6.10E+00
6.71 E+00
4.27E+01
Regional Hydraulic
Gradient
(m/m)
5.00E-02
2.30E-02
1.90E-02
1.00E-03
3.00E-03
2.00E-04
3.00E-05
3.30E-03
-999
5.00E-04
Note: -999 indicates a missing sample value.
Table D.26 Hydrogeologic Statistics for HG Environment 11
Hydraulic
Conductivity
ln(cm/s]
Unsaturated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Coastal Beaches
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-5.38023
Unsaturated
Zone Thickness
In(ft)
1 .8991
Saturated Zone
Thickness
In(ft)
3.7492
Regional
Hydraulic
Gradient
(m/m
-5.61773
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s;
3.48349
0.52513
-0.00429
-0.63963
Unsaturated
Zone Thickness
In(ft)
0.46903
0.18069
-0.2284
Saturated Zone
Thickness
In(ft)
2.02612
-0.08327
Regional
Hydraulic
Gradient
(m/m
1 .97797
D-84
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.27 Hydrogeologic Database for HG Environment 12
Subsurface Environment Description
Solution Limestone
Hydraulic
Conductivity
(m/yr)
1.58E+05
-999
1.58E+03
-999
-999
1.58E+03
1.26E+02
3.15E+02
-999
-999
-999
1.58E+04
-999
2.21 E+02
3.15E+02
2.49E+04
1.23E+04
-999
9.46E+01
1.26E+03
2.18E+03
6.31 E+03
Unsaturated Zone
Thickness
(m)
3.00E+01
5.00E+01
5.08E+01
1.52E+01
3.05E+00
4.57E+01
3.05E+00
1.22E+01
3.05E+01
3.20E+02
5.33E+00
2.93E+01
1.83E+01
-999
3.96E+00
1.52E+00
3.96E+00
3.05E+00
7.62E+00
4.00E+02
1.68E+00
1.22E+00
Saturated Zone
Thickness
(m)
3.00E+01
1.00E+01
1.44E+02
9.14E+01
-999
-999
1.52E+01
6.10E+01
-999
-999
1.52E+01
1.95E+01
-999
3.96E+01
3.05E+00
-999
1.83E+01
3.05E+02
1.98E+01
1.80E+01
7.32E+00
3.05E+00
Regional Hydraulic
Gradient
(m/m)
6.00E-03
5.00E-03
2.30E-02
-999
1.20E-02
-999
5.00E-05
3.30E-02
2.00E-02
9.00E-03
1.00E-03
-999
-999
2.00E-03
1.80E-02
2.00E-03
9.00E-03
1.00E-03
1.00E-02
2.00E-06
4.20E-04
-999
Note: -999 indicates a missing sample value.
D-85
-------
Appendix D
WMU and Hydrogeologic Environment Databases
Table D.28 Hydrogeologic Statistics for HG Environment 12
Hydraulic
Conductivity
ln(cm/s]
Unsatu rated Zone
Thickness ln(ft]
Saturated Zone
Thickness ln(ft]
Regional Hydraulic
Gradient ln(ft/ft)
Subsurface Environment Statistics
Solution Limestone
Mean Values
Hydraulic
Conductivity
ln(cm/s)
-5.6496
Unsatu rated
Zone Thickness
In(ft)
3.47765
Saturated Zone
Thickness
In(ft)
4.32063
Regional
Hydraulic
Gradient
(m/m
-5.49537
Covariance Matrix
Hydraulic
Conductivity
ln(cm/s)
12.0503
1.43257
0.53279
0.79733
Unsatu rated
Zone Thickness
ln(ft)
1 .25667
0.99541
1.35511
Saturated Zone
Thickness
ln(ft)
1.2437
0.81132
Regional
Hydraulic
Gradient
(m/m
4.45451
Table D.29 Hydrogeologic Database for HG Environment 13
Subsurface Environment Description
Undefined Hydrogeological Region
(Parameters values represent the average of the 12 regions).
Hydraulic
Conductivity
(m/yr)
1890
Unsaturated Zone
Thickness
(m)
5.18
Saturated Zone
Thickness
(m)
10.1
Regional Hydraulic
Gradient
(m/m)
5.70E-03
D-86
------- |