f/EPA
United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(5305W)
EPA530-R-97-023
NTIS: PB97-176 853
February 1996
Groundwater Pathway
Analysis for Aluminum
Potliners (K088); Draft
Printed on paper that contains at lest 20 percent postconsumer fiber

-------
GROUNDWATER PATHWAY ANALYSIS
FOR ALUMINUM POTLINERS (K088)
DRAFT
U.S. Environmental Protection Agency
Office of Solid Waste
Washington, DC 20460
February 16, 1996

-------
TABLE OF CONTENTS
	Page
1.0 INTRODUCTION 		 1
2.0 MODELING APPROACH AND DATA SOURCES 	 2
2.1	Modeling Approach and Problem Definition	 2
2.2	Source Related Parameters					9
3.0 RESULTS			11
4.0 REFERENCES 							15

-------
LIST OF TABLES
Page
Table 2.1	EPACMTP Modeling Options	 5
Table 2.2	Site-specific Input Parameters	 6
Table 2,3	Frequency Distribution of Landfill Area 			:	 7
Table 2.4	Frequency Distribution of Receptor Well Distance			 8
Table 2.5	TCLP Concentrations of Constituents of Concern 		10
Table 3.1	HWIR-based Leachate Concentrations and Dilution Factors	12
Table 3.2	K088 Groundwater Pathways Analysis with 20% Infiltration Rate	13
Table 3.3	K088 Groundwater Pathways Analysis with 30% Infiltration Rate	14
ii

-------
1.0 INTRODUCTION
A Monte Carlo modeling analysis was performed to assess the potential groundwater exposure and
human health risk due to dissolved chemicals associated with the disposal of aluminum potliners (K088) in
landfill waste management units. The modeling analysis was performed using the EPA Composite Model for
Leachate Migration with Transformation Products model (EPACMTP; EPA, 1995a). The EPACMTP model
was selected for the analyses because of its capabilities to perform a full, Monte Carlo-based, probabilistic
exposure assessment.
EPACMTP has been designed for Monte Carlo groundwater exposure assessments. The model
incorporates default probability distributions for the source, climatic and hydrogeologic parameters needed
by the fate and transport model. These distributions have been recently revised (EPA, 1995a,b) to ensure that
the most current data available are used.
This document describes the application of EPACMTP to model the groundwater impact of the
disposal of aluminum potliners. Section 2 describes the modeling approach and data sources used. Section
3 presents the results of the fate and transport modeling. References are provided in Section 4.
1

-------
2.0
MODELING APPROACH AND DATA SOURCES
2.1 Modeling Approach and Problem Definition
The EPACMTP modeling approach for the groundwater pathway analysis is summarized in Table 2,1
The modeling analysis was conducted in finite source, Monte Carlo mode for a Subtitle-C landfill waste
management scenario. The groundwater fate and transport model was used to predict the groundwater
exposure concentration at a receptor well placed, according to a specified probability distribution, within the
one-mile radius down gradient of the unit. The exposure concentration is taken to be the peak receptor well
concentration occurring within 10,000 years following the initial release from the waste unit for
noncarcinogens and nine-year maximum average concentration for carcinogens. The Monte Carlo fate and
transport simulation provides a probability distribution of receptor well concentrations which can be used to
determine the likelihood that a given exposure level will be reached (or exceeded). The exposure
concentrations are compared against health-based groundwater concentration numbers (HBNs) to determine
the health risks.
Table 2.1 lists the methodology and data sources used to obtain values for the source-specific
parameters, chemical-specific parameters, unsaturated zone parameters, saturated zone parameters, and
receptor well location parameters. All parameters are, in principle, described by probability distributions.
The determination of the source related parameters for the aluminum potliners modeling analysis is discussed
in Section 2.2, Probability distributions for other model input parameters are presented in the EPACMTP
background documents (EPA, 1995a-e). Key aspects of the modeling approach are discussed below.
In the EPACMTP Monte Carlo modeling approach, the climatic and hydrogeological model
parameters were assigned values based on the geographical locations of waste sites across the U.S. This
approach preserves the interdependence between site locations and climatic and hydrogeological regions. This
modeling approach was implemented based upon the 1985 Agency Survey of Industrial Subtitle D waste
facilities. In the aluminum potliners modeling analysis, the existing EPACMTP relations between climatic
and hydrogeological regions for landfills were used. The underlying assumption in using these relationships
is that the overall geographical distribution of Subtitle D industrial landfill sites, and Subtitle C landfill sites
receiving aluminum potliner waste across different climatic and hydrogeological regions in the U.S., is similar.
The aluminum potliners were assumed to be disposed of at landfills across the nation with the
following disposal proportion: 40 percent at the Facility in Arlington, OR; 40 percent at the Chemical Waste
Management of Indiana, Inc. Adam Center Facility in Fort Wayne, IN; and the remaining 20 percent at other
Subtide C landfills. The landfill in Oregon is located within the Columbia Plateau. The local hydrogeology
consists of alternating layers of basalt flows and interbed materials. Overlying the basalt bedrock are
sedimentary deposits (Waste Management of Northwest, Arlington, Oregon Facility, 1991). The landfill in
Indiana is located over a series of tills, sedimentary units, and dolomites (Golder and Associates, 1991). Input
parameters specific to these two sites are presented in Table 2.2. In the Monte-Carlo simulation, input
parameters were assigned in accordance with landfill categories governed by cumulative probability shown
in Table 2.3.
The aluminum potliners are disposed of in Subtitle C landfills because of their classification as
hazardous waste. Subtitle C landfills are typically underlain by geomembranes and geosynthetic liners to
facilitate Ieachate collection and to mitigate leachate downward migration. In the analysis, the impact to the
groundwater was assumed to be due to potential failure of the liners. In addition, the potential leakage rates
through the liners were conservatively assumed based on best available information to be between 20 to 30
percent (Inyang and Tomassoni, 1992) of those estimated for Subtitle D landfills (which are unlined) using the
HELP model.
2

-------
In the modeling analysis, the receptor well is located anywhere within one mile downgradient side of
the waste unit. The (radial) distance between the receptor well and the down-gradient side of the waste unit
is given by an empirical probability distribution (Table 2.2), based upon reported distances between Subtitle
D landfills and the nearest downgradient domestic drinking water well. Table 2.3 indicates a median well
distance of about one-quarter mile (427 m). The horizontal transverse (y-direction) location of the well was
taken to be uniform within the areal extent of the plume. The vertical position of the well intake point (z-
direction) was taken to be uniform throughout the saturated thickness of the aquifer.
A list of coastituents of concern, for which the modeling analysis was conducted, is presented in Table
2.4. Recently, a groundwater pathway analysis for these coastituents was conducted in support of the EPA
Hazardous Waste Identification Rule Proposal (HWIR; EPA, 1995-e) for Subtitle D landfills. In the current
analysis, the previous HWIR results were extrapolated via the procedure presented below.
1.	For a given infiltration rate, perform a Monte-Carlo run with 2,000 realizations. Each
realization was based on the following conservative assumptions; no decay; no adsorption;
and continuous source. Because of the absence of adsorption and decay, a single Monte-
Carlo run with unit source concentration was conducted. Concentrations at the receptor for
each constituent were determined by scaling the EPACMTP solution using the source
concentrations described in Section 2.2.
2.	Determine dilution factors for the constituents of concern using the following relationship:
.HWIR CHWm
K088
KOS8
(1)
where
DAFf88
dilution factor of constituent i based on K088 analysis
DAFf
'HWIR
dilution factor of constituent i based on HWIR analysis

receptor well concentration of non-sorbing, non-degrading
constituent based on KO88 analysis
qHWIR
receptor well concentration of non-sorbing, non-degrading
constituent based on HWIR analysis
Note that the dilution factor is defined as the ratio of the leachate concentration of a
constituent to the maximum concentration of that constituent at the receptor well. Note also
that the ratio of HWIR-to-K088 DAF is the inverse of the ratio of HWlR-to-K.088 receptor
well concentration.
3. Estimate the receptor well concentration of each constituent in the K088 analysis as
3

-------
c
¦, RW
c,
tclp
DAF,
K088
(2)
where
CircLP = TCLP leaching concentration for constituent i (Table 2.5)
C*w = Receptor well exposure concentration for constituent i
Determine risk for all the constituents of concern using the following relationships, for non-
carcinogens and carcinogens, respectively:
non-carcinogen: HOt =
C
RW
HBN
(3a)
carcinogen:
C
RW
RISK = —1— * 10"
' HBN
(3b)
where
HQi
RISK;
HBN
Hazard quotient for coastituent i
cancer risk associated with constituent i
health-based number (concentration corresponding to the risk of 106 for
carcinogens or hazard quotient of 1 for non-carcinogens).
The procedure described above is based on the assumption that the effect of reducing the infiltration rate and
incorporating 2 landfills which receive 80% of the waste, is the same for all constituents. This impact is
estimated in terms of the change in DAF for a non-degrading, non-sorbing constituent, as compared to the
DAF for the HWIR modeling scenario. The constituent-specific DAFs available from the HWIR analysis are
then adjusted using a constant scaling factor (Equation 1) to estimate receptor well concentrations and risks
for each constituent.
4

-------
Table 2.1 EPACMTP Modeling Options for LBP Analysis
Management Scenarios:
Subtitle C landfill
Modeling Scenario:
Finite Source Monte Carlo; 2,000 realizations
Exposure evaluation:
Down gradient groundwater receptor well; peak well concentration
10,000 year exposure time limit
Source Parameters:
Waste Unit Area:
Infiltration Rate:
Site-specific data from two landfills, and OPPI Survey of D landfills
(EPA, 19995-b)
Site-based, 20%-30% of values derived using the HELP model for
Subtitle D landfills
Leaching Duration
Infinite
Chemical Specific Parameters:
Decay Rate:
Constituent-spec ific
Sorption:
Constituent-specific
Unsaturated Zone Parameters:
Depth to groundwater:
Soil Hydraulic Parameters:
Fraction Organic Carbon:
Bulk Density:
Site-based, from API/USGS hydrogeologic database
ORD data based on national distribution of three soil types (sandy loam,
silt loam, silty clay loam)
ORD data based on national distribution of three soil types (sandy loam,
silt loam, silty clay loam)
ORD data based on national distribution of three soil types (sandy loam,
silt loam, silty clay loam)
Saturated Zone Parameters:
Recharge Rate:
Saturated Thickness:
Hydraulic Conductivity:
Porosity:
Bulk Deasity:
Dispersivity:
Groundwater Temperature:
Fraction Organic Carbon:
pH
Site-based, derived from regional precipitation/evaporation and soil type
Site-based, from API/USGS hydrogeologic database
Site-based, from API/USGS hydrogeologic database
Effective porosity derived from national distribution of aquifer particle
diameter
Derived from porosity
Derived from distance to receptor well
Site-based, from USGS regional temperature map
National distribution, from EPA STORET database
National distribution, from EPA STORET database
Receptor Well Location:
X-distance
Y-distance
Depth of Intake Point
Empirical distribution within 0-1 mile from waste unit
Uniform within 1 mile downgradient radius
Uniform throughout saturated thickness of aquifer
5

-------
Table 2.2 Site-Specific Input Parameters
Parameter
Oregon Site
Indiana Site
Landfill Area (m*2)
182,115*
543,810**
Climatic Region
2 (Boise, ID)
73 (Indianapolis, IN)
Hydrogeologic Region
1 (Metamorphic and Igneous)
15 (outwash)
Weight of the Site (%)
40***
4Q***
Groundwater
Temperature (°C)
12,5
12.5
Depth to the Ground
Water (m)
45.73*
13.2**
Saturated Zone
Thickness (m)
15.2*
21.34**
Hydraulic Conductivity (m/
Reported
Default HWIR Data
Base
vr)
Range(3.15E-3 -31.5)*
Range(3.15 - 1.1E + 4)
Range(9.46E+3 -
1.89E+4)**
Range(4.57- 1.1E+5)
Hydraulic Gradient


Reported
Range(0.01 - 0.04)*
Range( 0.001 -0.004)**
Default HWIR Data
Base
Range(7.0E-6 - 0.1)
Range(8.0E-7 - 0.075)
Chem Waste of Northwest, Arlington, Oregon, Facility (1991)
Golder and Associates (1991)
Assumed disposed of at 40% at each of these two landfills and the remaining 20% at other Subtitle
C landfills distributed nationally.
Notes
*
**

-------
Table 2.3 Frequency Distribution of Receptor Well Distance
Distance (m)
Cumulative Frequency
0.0
0.00
0.6
0.00
13.7
0.03
19.8
0.04
45.7
0.05
104
0.10
152
0.15
183
0.20
244
0.25
305
0.30
305
0.35
366
0.40
427
0.50
610
0.60
805
0.70
914
0.80
1160
0.85
1220
0.90
1370
0.95
1520
0.98
1610
1.00
7

-------
2.2 Source Related Parameters
EPACMTP requires specification of the waste source area, and the leachate concentration emanating
from the base of the waste source. These two parameters are entered directly as input parameters to the model.
The discussion as to how the two parameters were determined for the aluminum potliners analysis is presented
below.
Landfill Area
As discussed in Section 2.1, the cumulative probability distribution of the landfill is according to Table
2.3. As shown in the table, the landfill area is equal to that of the Oregon site 40 percent of the realizations,
is equal to that of the Indiana site 40 percent of the realizations, and assumes the OPPI Survey distribution
(EPA, 1986) 20 percent of the realizations.
Leachate Concentration
Leachate concentrations of constituents of concern were assumed to be equal to their respective
average Toxicity Characteristics Leaching Procedure (TCLP) concentrations. In the event that the TCLP
concentrations were unavailable, the TCLP concentrations were assumed to be equal to 1/20 of the respective
total waste concentrations (Conrad and Deever, 1992). The leachate concentrations of constituents of concern
are presented in Table 2.5. It may be noted that for those constituent for which both leachate and total waste
concentration values are available, the ratio of waste-to-leachate concentration is generally much greater than
20. In other words, the assumed ratio of 20 used in this analysis likely results in a conservative (high-end)
estimate of the leachate concentration.
8

-------
Table 2.4 TCLP Concentrations of Constituents of Concern


TCLP

Constituent
CAS No.
(mg/L)
Data Source
Cyanide (Total)
57-12-5
1.09e+02
c
Cyanide (Amenable)
57-12-5
4,60e+01
c
Fluoride
16964-48-8
2.33e+03
c
Lead
7439-92-1
5.10e-02
a
Benzo(a)pyrene
50-32-8
1.19e+00
c
Beryllium
7440-41-7
2.67e-02
b
Arsenic
7440-38-2
3.23e-01
a
Antimony
7440-36-0
1.79e-01
a
Chromium (total)
7440-47-3
3.50e-02
a
Barium
7440-39-3
1.14e-01
a
Nickel
7440-02-0
2.18e-01
a
Cadmium
7440-43-9
8.00e-03
a
Pyrene
129-00-0
1.41e+00
c
Fluoranthene
206-44-0
1.74e+00
c
Selenium
7782-49-2
2,80e-02
a
Mercury
7439-97-6
1.00e-03
a
Silver
7440-22-4
2.80e-02
a
Data Sources
a)	Aluminum Association sampling results.
b)	Characterization of spent potliners reduction of aluminum, EPA (1991)
c)	No TCLP value available, concentration was estimated as 1/20 of average waste concentration
(mg/kg) obtained from K088 sampling
9

-------
3.0 RESULTS
Shown in Table 3.1 are health-based numbers (see Section 2.1 for definition) and dilution factors from
the HWIR analysis (EPA, 1995-e). Following the analysis procedure oudined in Section 2.1, two sets of
Monte-Carlo simulations were performed: one with 20 percent of the infiltration rate for the Subtitle D
landfills; and the other with 30 percent of the infiltration rate for the Subtitle D landfills. For each Monte-
Carlo simulation, utilizing the constituent concentrations at the receptor well from the K088 and HWIR
analyses, as well as the dilution factors from the HWIR analysis (Table 3.1), dilution factors were calculated
for respective constituents. The dilution factors were then employed to determine groundwater exposure
concentrations at receptor wells. The constituent concentrations thus determined at the 50th and 90th
percentiles were then used to determine risks (for carcinogens) or hazard quotients (for non-carcinogens). The
50th and 90th percentile groundwater exposure concentrations and associated risks or hazard quotients for the
cases of 20 percent and 30 percent infiltration rates are presented in Tables 3.2 and 3.3, respectively.
In Table 3.2, it can be seen that, the 90th-percentile risks associated with all three carcinogens exceed
10 s. Among the three carcinogens, benzo(a)pyrene has the highest risk. The 50th-percentile risk of this
chemic;il is the only one exceeding 10 s. For the non-carcinogens shown in the table, all the 50th-percentile
hazard quotients are below unity, with fluoride being the constituent with the highest hazard quotient. At the
90th percentile, the hazard quotients of fluoride and lead well exceed unity.
Results shown in Table 3.3 are similar to those in Table 3.2. Groundwater exposure concentrations,
risks, and hazard quotients in this table are somewhat greater(approximately 1.5 to three times) than those in
Table 3.2, as expected. Also shown in the table, the 50th percentile, risks due to two carcinogens, arsenic and
benzo(a)pyrene, exceed 10"5.
10

-------
Table 3.1 HWIR-based Leachate Concentrations and Dilution Factors
Constituent
CAS No.
HBN
(mg/L)
HWIR Min.
Leachate
Cone. (mg/L)
HWIR
DAF
Cyanide (Total) #
57-12-5
7.30e-01
1.00e + 06
1.37e + 06
Cyanide (Amenable) #
57-12-5
7.30e-01
1.00e+06
1.37e + 06
Fluoride #
16964-48-8
2.20e+00
1.80e + 01
. 8.18e + 00
Lead
7439-92-1
3.70e-06
7.50e+01
2.03e + 07
Benzo(a)pyrene
50-32-8
1.00e-05
1.80e-04
1.80e+01
Beryllium
7440-41-7
2.00e-05
2.10e-03
1.05e+02
Arsenic
7440-38-2
5.00e-05
9.60e-04
1.92e+01
Antimony
7440-36-0
1.00e-02
3.40e-01
3".40e + 0l
Chromium (total) *
7440-47-3
2.00e-01
3.10e+00
1.55e + 01
Barium
7440-39-3
3.00e+00
8.40e+01
2.80e + 01
Nickel
7440-02-0
7.00e-01
2,60e+01
3.71e+01
Cadmium
7440-43-9
2.00e-02
6.00e-01
3.00e + 01
Pyrene
129-00-0
1.00e+00
1.90e + 01
1.90e+01
Fluoranthene
206-44-0
1.00e+00
1.90e+01
1.90e + 01
Selenium
7782-49-2
2.00e-01
2.30e+00
1.15e+01
Mercury
7439-97-6
1.00e-02
7.50e-01
7.50e+01
Silver
7440-22-4
2.00e-01
4.10e+00
2.05e+01
Notes
1.	TCLP = mean value of reported TCLP concentrations for each constituent; for cyanide, fluoride,
benzo(a)pyrene, fluoranthene, and pyrene TCLP estimated as 1/20-th of total concentration.
2.	HBN = reference exposure concentration corresponding to risk=10 -6 / HQ= I; values as used for
HWIR, except cyanide, fluoride and lead from EPA Region III RBC tables
3.	* The HWIR DAF presented above is that of Chromium ( + 6).
4.	# Constituent is not in the HWIR list, however, DAF has been calculated based on HWIR modeling
procedure, using hydrolysis half-life of 8.41 yrs for cyanides.
11

-------
Table 3.2 KO88 Groundwater Pathways Analysis with 20% Infiltration Rate
Constituent
CAS No.
HBN
(mg/L)
TCLP
(mg/L)
GW Exposure
50th Percentile
Cone. (mg/L)
90th Percentile
Risk
50th Percentile
»r HQ
90-th Percentile








Cvanide (Total)
57-12-5
0.73
1.09e+02
2.35e-07
8.38e-05
3.22e-07
1.15e-04
Cvanide (Amenable)
57-12-5
0.73'
4.60e+01
9.94e-08
3.55e-05
1.36C-07
4.86e-05
Fluoride
16964-48-8
2.20
2.33e-f 03
2.80e-01
9.98e+01
1.27e-01
4.54e+01
Lead
7439-92-1
3,70e-06
5.10e-02
2,20e-08
7.86e-06
5.95e-03
2.12e+G0
Benzo(a)pyrene
50-32-8
1.00e-05
1.19c+00
1.43e-04
5,09e-02
1.43e-05
5.09e-03
Beryllium
7440-41-7
2.00e-05
2.67e-02
5.55e-07
1,98e-04
2.77e-08
9.89e-06
Arsenic
7440-38-2
5 00e-05
3.23e-01
3.63e-05
1.29e-02
7.26e-07
2,59e-04
Antimony
7440-36-0
0.01
l,79e-01
1.13e-05
4.02e-03
1.13e-03
4.02e-01
Chromium (total)
7440-47-3
0.20
3.50e-02
4.89e-06
1.75e-03
2.45e-05
8.73e-Q3
Barium
7440-39-3
3.00
1.14e-01
8.85e-06
3.16e-03
2.95e-06
1.05e-03
Nickel '
7440-02-0
0.70
2.18e-01
1.25e-05
4.47e-03
1.79e-05
6.39e-03
Cadmium
7440-43-9
0.02
8.00e-03
5.76e-07
2.05e-04
2.88e-05
1.03e-02
Pvrene
129-00-0
1.00
l,41e+00
1.60e-04
5.72e-02
1.6Ge-04
5.72e-02
Fluoranthene
206-44-0
1.00
1.74e+00
1.98e-04
7.06e-02
1.98e-04
7.06e-02
Selenium
7782-49-2
0.20
2.80e-02
5.21e-06
1.86e-03
2.61e-05
9.30e-03
Mercury
7439-97-6
0.01
1.00e-03
2.90e-08
1.03e-05
2.90e-06
1.03e-03
Silver
7440-22-4
0.20
2.80e-02
2.52e-06
8.99e-04
l,26e-05
4.49e-03
TCLP = mean value of reported TCLP concentrations for each constituent; for cyanide, fluoride, benzo(a)pyrene, fluoranthene, and pyrcne TCLP estimated as 1/20-th of total concentration.
HBN = reference exposure concentration corresponding to a risk of 10 -6 for carcinogens and HQ of 1 for non-carcinogens;values as used for HWIR, except cyanide, fluoride and lead from EPA
Region III RBC tables
* infiltration is assumed to be 30% of the infiltration from a subtitle D landfill
Shaded region indicates carcinogens
12

-------
Table 3.3 KO88 Groundwater Pathways Analysis with 30% Infiltration Rate
Constituent
CAS No.
HBN
(mg/L)
TCLP
(mg/L)
GW Exposure
50th Percentile
Cone. (mg/L)
90th Percentile
Risk
50th Percentile
ar HQ
90-th Percentile








Cvanide (Total)
57-12-5
0.73
1.09e+02
6.50e-07
1.28e-04
8.90e-07
1,75e-04
Cyanide (Amenable)
57-12-5
0.73
4,60e+01
2.75e-07
5.41e-05
3.77e-07
7.42e-05
Fluoride
16964-48-8
2.20
2.33e+03
7.74e-01
1.52e + 02
3.52e-01 •
6.93e+0l
Lead
7439-92-1
3.70e-06
5.10e-02
6.10e-08
1.20e-05
1.65e-02
3.24e+00
Benzofaipvrene
50-32-8
1.00e-05
1.19e+00
3.95e-04
7.78e-02
3.95e-05
7.78e-03
Beryllium
7440-41-7
2.00e-05
2.67e-02
1.53e-06
3.02e-04
7.67e-08
1.51e-05
Arsenic
7440-38-2
5.00e-05
3.23e-01
1.00e-04
1.98e-02
2.01e-06
3.95e-04
Antimony
7440-36-0
0.01
1.79e-01
3.12e-05
6.14e-03
3.12e-03
6.14e-01
Chromium (total)
7440-47-3
0.20
3.50e-02
' 1.35e-05
2.67e-03
6.77e-05
1.33C-02
Barium
7440-39-3
- 3.00
1.14e-01
2.45e-05
4.82e-03
8.16e-06
1.61e-03
Nickel
7440-02-0
0.70
2.18e-01
3.47e-05
6.83e-03
4,95e-05
9.75e-03
Cadmium
7440-43-9
0.02
8.00e-03
1.59e-06
3.14e-04
7.97e-05
1,57e-02
Pvrene
129-00-0
1.00
1.41e+00
4.43e-04
8.73e-02
4.43e-04
8.73e-02
Fluoranthene
' 206-44-0
1.00
1.74e+00
5.47e-04
L08e-01
5,47e-04
1,08e-01
Selenium
7782-49-2
0.20
2.80e-02
1.44e-05
2,84e-03
7.21e-05
1.42e-Q2
Mercury
7439-97-6
0.01
1.00e-03
8.02e-08
1.58e-05
8.02e-06
1.58e-03
Silver
7440-22-4
0.20
2.80e-02
6.97e-06
1.37e-03
3.49e-05
6.86e-03
TCLP = mean value of reported TCLP concentrations for each constituent; for cyanide, fluoride, benzo(a)pyrene, fluoramhene, and pyrene TCLP estimated as 1/20-th of total concentration.
HDN = reference exposure concentration corresponding to a risk of 10 -6 for carcinogens and HQ of 1 for non-carcinogens;vaIues as used for HWIR, except cyanide, fluoride and lead from EPA
Region 111 RliC tables
* infiltration is assumed to be 30% of the infiltration from a subtitle D landfill
Shaded region indicates carcinogens
13

-------
4.0 REFERENCES
Conrad, D.L. and Deever, W.R, 1992. Save Test Dollars Using TCLP Alternative. Soils, April 1992.
Chem Waste of Northwest, 1991. RCRA Part B Permit Application, Arlington, Oregon Facility.
Colder and Associates, 1991. RCRA Part B Permit Renewal Application. Permit Application on behalf of
Chemical Waste Management of Indiana, Inc. Prepared by Colder and Associates.
•
USEPA, 1989. Subtitle D Landfill Survey. Prepared for Office of Solid Waste by DPRA, Inc., Washington,
D.C., 20460.
USEPA, 1992. Indexing of Long-Term Effectiveness of Waste Containment Systems for a Regulatory Impact
Analyis; A Draft Technical Guidance Document, Office of Solid Waste, Washington, D.C. 20460.
USEPA, 1995-a. EPA's Composite Model for Leachate Migration with Transformation Products
(EPACMTP), Background Document, Office of Solid Waste, Washington, D.C., 20460.
USEPA, 1995-b. EPA's Composite Model for Leachate Migration with Transformation Products. User's
Manual, Office of Solid Waste, Washington, D.C., 20460.
USEPA, 1995-c. EPA's Composite Model for Leachate Migration with Transformation Products
(EPACMTP). Background Document for Finite Source Methodology. U.S. EPA, Office of Solid Waste,
Washington, D.C., 20460.
USEPA, 1995-d. EPA's Composite Model for Leachate Migration with Transformation Products
(EPACMTP). Background document for Metals: Methodology. U.S. EPA, Office of Solid Waste,
Washington, D.C., 20460.
USEPA, 1995-e. Hazardous Waste Identification Rule. Background document for Groundwater Pathway
Results. U.S. EPA, Office of Solid Waste, Washington, D.C., 20460.
14

-------